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FIELD OF THE INVENTION
[0001] This invention relates to novel calcium phosphate-coated implantable medical devices and processes of making same. The unique calcium-phosphate coated implantable medical devices minimize immune response to the implant. The coated implantable devices have the capability to store and release one or more medicinally active agents into the body in a controlled manner.
BACKGROUND OF THE INVENTION
[0002] Cardiovascular stents are widely used in coronary angioplasty procedures to enlarge coronary arteries and thereby allow better blood circulation. Typically this is accomplished by a balloon angioplasty procedure wherein a contracted stent, usually in the form of a metallic mesh tube, is moved in to the site of blood vessel narrowing along a guide wire. Once the stent is in place an internally situated balloon expands it radially. After expansion the balloon is deflated and removed from vessel while the stent remains expanded in place. The stent thus provides a scaffold support for the walls of the blood vessel, enlarging the vessels aperture and increasing blood flow. This operation saves millions of lives annually around the world. Unfortunately the placement of metallic stents often leads to harmful side effects. A relatively large proportion of patients (up to half of the population, according to some statistics) experience an immune response to the implanted stent called inflammatory restenosis, and other negative effects, which lead to a re-narrowing of the vessel. This typically requires repeat surgical treatment within 1-2 years of the original balloon angioplasty operation.
[0003] The mechanisms that lead to restenosis and other immune responses associated with the implantation of a medical device are initiated by damage to the vessel lining during the surgical procedure. Such damage is very difficult to avoid entirely, but its effects, i.e. inflammation and/or infection, may be diminished through modifications to the surface of metallic implantable medical devices. The most common surface modification of implanted medical devices is the application of a thin polymer film coating. These coatings are frequently impregnated with medically active agent(s) such as antibiotics, anti-inflammatory agents and other, more complex drugs. These medically active agents are released from the coating through leaching to the arterial wall and the blood stream, often aided by dissolution of the carrier film. Typically, biodegradable polymers such as polylactic acid, polyglycolic acid, and others, frequently in combination with heparin and other anti-thrombogenic agents, are selected in such drug delivery systems. A particular advantage of the polymer coatings on stents is that the coatings are flexible and generally non-thrombogenic.
[0004] In the past, polymeric materials have been used for drug delivery control and have enjoyed substantial clinical success for certain drug systems. Unfortunately, even biodegradable polymers, although more bio-friendly than the native metallic surface, are still recognized by living tissue as foreign objects. Therefore the bio-degradation process is frequently accompanied by inflammatory response of the tissue. In some critical applications, such as cardiovascular stents, it has been determined that polymer coated stents do not perform according to expectations in longer term (in excess of 1 year) of use. Furthermore, in many instances relatively rapidly resorbing polymer coatings are quickly depleted, from the stent surface with concomitant loss of the long-term affects of the drug and harmful exposure of the bare metal surface to contact tissue. This may result in an adverse response of the tissue, leading to inflammation, restenosis (in the case of stents), and requiring repetitive surgical intervention.
[0005] There is therefore a strong need to discover materials for coating implantable medical devices that are entirely biocompatible and thus do not cause any adverse effects in the tissue. Furthermore, ideally this coating material will be able to deliver one or more pharmaceutically active agents to a targeted site. Studies have shown that porous coatings may accept the required load of drugs through adsorption and then release the drugs in a controlled manner. The drug release process is dependant on surface properties of the coating-material and the adsorption properties, molecular size, and other characteristics of the drug.
[0006] One group of materials exhibiting desired characteristics has been known for a long time, and is used extensively for the surface modification of large rigid implants such as artificial hips in the human body. These materials are members of the family of calcium phosphates (CaP) and include hydroxyapatite (HA), di- and tri-calcium phosphates, as well as partially or fully amorphous calcium phosphates. These materials are mineral components of hard tissue and as such are fully bio-compatible and bio-resorbable with no side effects. Calcium phosphate, in particular hydroxyapatite (HA), is a principal inorganic component of bone, and thus offers entirely new perspectives for coating-based drug encapsulation and drug delivery systems.
[0007] Hydroxyapatite ceramics, Ca 10 (PO 4 ) 6 (OH) 2 , belong to the class of calcium phosphate (CaP) based bioactive materials that are used for a variety of biomedical applications, including matrices for drug release control [M. Itokazu et al., Biomaterials, 19, 817-819, 1998; F. Minguez et al Drugs Exp. Clin. Res., 16[5], 231-235, 1990; W. Paul and C. P. Sharma, J. Mater. Sci. Mater. Med., 10, 383-388, 1999]. Other members of the CaP family, such as dicalcium phosphate (CaHPO 4 .2H 2 O) or tricalcium phosphate (Ca 3 (PO 4 ) 2 ), have also been used for similar purposes. The CaP family of materials has been long recognized as having a high degree of biocompatibility with human tissue.
[0008] The use of calcium phosphate coatings, including HA coatings, thermally deposited on implantable devices has been limited by the fact that such coatings used to date have had thicknesses of >0.01 mm and have exhibited brittle behaviour when in bulk form. This characteristic has limited their use to applications where a solid support structure, such as dental or hip implant, does not allow for much deformation of the structure. In such cases, the potential for coating damage is limited and osseo-integration with the tissue occurs in an improved manner. HA coated implants in particular have been shown to possess excellent biocompatibility and provide accelerated integration of the implant with the surrounding tissue. The bio-resorption rate of such coatings can be controlled through adjustment of their crystallinity and chemical composition, e.g. by the incorporation of carbonate groups and other methods known to those skilled in the art.
[0009] A method alternative to thermal coating is the biomimetic deposition of HA films at room temperature (BM-HA). This technique has been used for a variety of biomedical applications, for example drug delivery [H. B. Wen et al, J. Biomed. Mater. Res., 41, 227-36, 1998; S. Lin and A. A. Campbell, U.S. Pat. No. 5,958,430, 1999; D. M. Liu et al J. Mater. Sci. Mater. Med., 5, 147-153, 1994; K. de Groot et al, J. Biomed. Mater. Res., 21, 1375-1381, 1987). This forming mechanism is driven by supersaturation of Ca 2+ and PO 4 3− , under appropriate solution pH, where HA is the most stable phase. As the process proceeds at or near room temperature, the apatitic crystals which form through nucleation and growth may incorporate biologically active species, such as antibiotics, anti-cancer drugs, anti-inflammatory agents, etc. The deposition rates for BM-HA are in the range of 0.05-0.5 μm/h.
[0010] This relatively low deposition rate may be enhanced significantly if electric field is applied to the metallic substrate being coated, e.g. stent, in a solution containing proper concentration of calcium and phosphorous ions. This variant of coating is usually referred to as Electro-Chemical Deposition (ECD), and the resulting film termed as ECD-HA. As ECD also proceeds at (or near) room temperature, drug encapsulation is also possible in ECD-HA. The physiological solutions for BM-HA formation are naturally water-based, which makes it impossible to encapsulate hydrophobic bioactive agents into BM-HA coatings. The biomimetic HA films (both BM-HA and ECD-HA) may be deposited on implantable medical devices at room temperature, which is of great advantage for drug encapsulation during deposition.
[0011] Unfortunately, the bonding strength BM-HA and ECD-HA to metallic surfaces is generally significantly lower than that of sol-gel HA (termed here SG-HA). At the same time, bonding strength of BM-HA or ECD-HA to previously consolidated hydroxyapatite is high, generally in excess of 40 MPa. In this respect building additional BM-HA or ECD-HA film on top of the already existing, well-bonded to the metallic substrate film of SG-HA provides a novel and inventive route to achieve high bonding strength, controlled porosity, and drug encapsulation capability of the films deposited at room temperature,
[0012] Another alternative for room (or near-room) temperature deposition of porous calcium phosphate films, in particular hydroxyapatite, for drug impregnation and encapsulation, is so-called calcium phosphate cement (CPC) route. In this previously disclosed process (refer to U.S. Patent Application No. US2002/0155144 A1 “Bifunctional Hydroxyapatite Coatings and Microspheres for in-situ Drug Encapsulation”, by T. Troczynski, D. Liu, and Q. Yang), fine particles of calcium phosphate precursor Ca(OH)2 and calcium phosphate salt monocalcium phosphate anhydrate, are milled and mixed in ethanol, followed by film deposition and impregnation by sodium phosphate solution (refer to the Example 4 below for details of this procedure). As a result of this process, microporous, semi-amorphous CPC-HA results, suitable for delivering drugs through leaching and during film resorption. Similarly as above, CPC-HA film bonds poorly to metallic surfaces, such as those of implants or stents. However, CPC-HA film deposited on previously consolidated surface of HA, such as SG-HA, achieves high bonding strength, generally in excess of 40 MPa. In this respect building additional CPC-HA film on top of the already existing, well-bonded to the metallic substrate film of SG-HA provides a novel and inventive route to achieve high bonding strength, controlled porosity, and drug encapsulation capability of the films deposited at room temperature.
[0013] Electric field-assisted thin film deposition technologies have the great advantage of the resulting film uniformity, especially for complex substrates such as stents. One such technology termed Electro-Phoretic Deposition (EPD) is well known method in ceramic processing. In this method fine particles of a ceramic (generally about a micrometer or less in size) suspended in a liquid attain electric charge through interaction with the liquid or through addition to the suspension of surface-active species. The simplest example of such EPD system is oxide (or hydroxide, such as hydroxyapatite) ceramic powder suspended in water and acid (such as nitric acid) mixture. In such environment protons will have a tendency to absorb on surface of the ceramic particles, providing positive charge to the particles. Upon application of electric field, such charged particles would migrate to the negative electrode (cathode). Exactly opposite would happen in basic environment, i.e. negatively charged particles of ceramic would migrate to the positive electrode (anode). EPD is an excellent technique for deposition of ceramic films, including calcium phosphate films, as disclosed in U.S. Pat. No. 5,258,044, dated Nov. 2, 1993 (“Electro-phoretic Deposition of Calcium Phosphate Material on Implants”, by D. D. Lee). Unfortunately, EPD films must be sintered at relatively high temperature to gain sufficient structural integrity. For example, the EPD films of calcium phosphate disclosed in U.S. Pat. No. 5,258,044, had to be sintered at between 600° C. and 1350° C. These temperatures are high enough to induce substantial change to the metallic substrate, e.g. in terms of surface oxidation or microstructural changes (e.g. grain growth).
[0014] Drug encapsulation in HA has been achieved in the past by simple post-impregnation of a sintered, porous HA ceramic [K. Yamamura et al, J. Biomed. Mater. Res., 26, 1053-64, 1992]. In this process, the drug molecules simply adsorb onto the surface of the porous ceramic. The drug release is accomplished through desorption and leaching of the drug to the surrounding tissue after exposure to physiological fluid. Unfortunately, most of the adsorbed drug molecules release from such system in a relatively short period of time. Impregnation of drug material into porous sintered calcium phosphate microspheres has been reported in the patent literature. “Slow release” porous granules are claimed in U.S. Pat. No. 5,055,307 [S. Tsuru et al, 1991], wherein the granule is sintered at 200-1400° C. and the drug component impregnated into its porosity. “Calcium phosphate microcarriers and microspheres” are claimed in WO 98/43558 by B. Starling et al [1998], wherein hollow microspheres are sintered and impregnated with drugs for slow release. D. Lee et al. [WO98/16209] claim poorly crystalline apatite wherein macro-shapes harden and may simultaneously encapsulate drug material for slow release. It has been suggested to use porous, composite HA as a carrier for gentamicin sulfate (GS), an aminoglycoside antibiotic to treat bacterial infections at infected osseous sites [J. M. Rogers-Foy et al, J. Inv. Surgery 12 (1997) 263-275]. The presence of proteins in HA coatings did not affect the dissolution properties of either calcium or phosphorus ions and that it was solely dependent on the media [Bender S. A. et al. Biomaterials 21 (2000) 299-305].
[0015] Stents are disclosed in several patent publications. U.S. patent publication No. 2002/0007209 A1, published Jan. 17, 2002, de Sheerder et al., discloses an expandable metal tube prosthesis with laser cuts in the walls. The prosthesis can be coated with titanium nitride (TiN) for bio-compatibility. The holes in the walls of the prosthesis can be used to locally administer medicines and the like.
[0016] U.S. Pat. No. 6,387,121 B1, issued May 14, 2002, Alt, assigned to Inflow Dynamics Inc., discloses a stent constructed with a tubular metal base. The stent can be constructed to have three layers (see FIG. 2 ). The first layer 15 is typically 316L stainless steel. The intermediate layer 50 is formed of a noble metal or an alloy thereof, preferably selected from a group consisting of niobium, zirconium, titanium and tantalum (see column 7, lines 58-61). The third or outer layer 80 is preferably composed of a ceramic-like metal material such as oxide, hydroxide or nitrate of metal, preferably iridium oxide or titanium nitrate, as a bio-compatible layer that serves as a primary purpose to avoid tissue irritation and thrombus formation.
[0017] EP 0 950 386 A2, published Oct. 20, 1999, Wright et al., assigned to Cordis Corporation, discloses a thin walled stent which is formed as a cylinder with a plurality of struts. The struts have channels formed therein. Therapeutic agents can be deposited in the channels. Rapamycin specifically is mentioned as a therapeutic agent which can be deposited in the channels to prevent restenosis (re-narrowing) of an artery.
SUMMARY OF THE INVENTION
[0018] The invention is directed to an implantable medical device with a calcium phosphate coating comprising: (a) substrate; and (b) calcium phosphate coating on the substrate, said coating having desired bonding and porosity characteristics.
[0019] The calcium phosphate coating of the device can be hydroxyapatite. The thickness of the calcium phosphate coating can be between about 0.00001 mm and 0.01 mm, and preferably about 0.001 mm to 0.0001 mm. The tensile bond strength between the substrate and the calcium phosphate coating can be greater than about 20 MPa. The calcium phosphate coating can be deposited on the device as particles having a diameter between about 1 μm and 100 μm and a thickness of between about 1 μm to 10 μm. The particles can cover about 20% to about 90% of the surface of the substrate.
[0020] The implantable medical device can be constructed of stainless steel, cobalt alloy, titanium cobalt-chromium or metallic alloy. The calcium phosphate coating can be porous and the pores can retain a drug. The rate of release of the drug from the pores can be controlled in an engineered manner.
[0021] The substrate can have a first calcium phosphate coating and a second calcium phosphate coating and the drug can be contained in both the first and the second coating or only in one coating. The drug can be one which inhibits restenosis. The calcium phosphate coating can be dicalcium phosphate, tricalcium phosphate or tetracalcium phosphate. The device can be a human or animal tissue implantable device. The device can be a stent which is coated with calcium phosphate.
[0022] The invention is also directed to a process of coating an implantable medical device with a calcium phosphate coating comprising: (a) hydrolyzing a phosphor precursor in a water or alcohol based medium; (b) adding a calcium salt precursor to the medium after the phosphite has been hydrolyzed to obtain a calcium phospate gel; (c) depositing the calcium phosphate gel as a coating on the surface of a substrate; and (d) calcining the calcium phosphate coating at a suitable elevated temperature and for pre-determined time to obtain a crystallized calcium phosphate having desired crystallinity, bonding and porosity characteristics.
[0023] The deposition of the coating on the substrate can be performed by aerosol deposition, dip-coating, spin-coating, electrophospate coating or electrochemical coating. The calcium phosphate coating can be calcined at a temperature of at least about 350° C. The calcium phospate gel can be hydroxyapatite gel.
[0024] The porosity of the calcium phosphate coating can be controlled and can retain a drug. The rate of release of drug can be controlled. The calcium phosphate coating can be hydroxyapatite, dicalcium phosphate, tricalcium phosphate or tetracalcium phospate.
[0025] The phosphate precursor can be an alkyl phosphite or a triethyl phosphate. The calcium precursor can be a water-soluble calcium salt. The water soluble calcium salt can be calcium nitrate.
[0026] The invention is also directed to a process of coating a soft tissue implantable device with a calcium phosphate coating comprising: (a) providing a soft tissue implantable substrate; (b) depositing a calcium phosphate coating on the substrate utilizing a biomimetic deposition process; or (c) depositing the calcium coating on the substrate utilizing a calcium phosphate cement deposition process; or (d) depositing the calcium phosphate coating on the substrate utilizing an electro-phoretic deposition process; or (e) depositing a calcium phosphate coating on the substrate utilizing an electrochemical deposition process.
[0027] The device can be a calcium phosphate coated stent. The calcium phosphate coating can be hydroxyapatite. The calcium phosphate coating can be deposited discontinuously on the substrate as discrete particles.
[0028] A first calcium phosphate coating can be deposited on the substrate utilizing an aerosol-gel process, a sol-gel process or an electro-phoretic deposition process or an electro-chemical deposition process and a second calcium phosphate coating can be deposited on the first coating or the substrate utilizing an aerosol-gel process, a sol-gel process, a biomimetic process, a calcium phosphate cement process, an electro-phoretic deposition process or an electrochemical deposition process.
[0029] The calcium phosphate coating can contain and elude a drug. The calcium phosphate coating can be coated with a hydrogel film. The calcium phosphate can be deposited on the substrate as discontinuous non-equiaxial particles. The non-equiaxial particles can have an average size of about 0.1 μm and a thickness up to about 0.01 mm. The first and second coatings can contain a drug.
[0030] The ratio of calcium to phosphate in the sol-gel precursor can be engineered to enable various phosphate phases to be obtained. The calcium phosphate phase can be hydroxyapatite, dicalcium phosphate, tricalcium phosphate or tetracalcium phospate.
DRAWINGS
[0031] In drawings which illustrate specific embodiments of the invention, but which should not be construed as restricting the spirit or scope of the invention in any way:
[0032] FIG. 1A is a micrograph of a stainless steel (316L) stent coated with discontinuous ASG-HA thin film.
[0033] FIG. 1B is a magnification of the sector indicated by the rectangle of FIG. 1A .
[0034] FIG. 2A is a micrograph of a stainless steel stent (316L) coated with discontinuous ASG-HA thin film and crimpled, with no damage to the coating.
[0035] FIG. 2B is a micrograph of the same stent as shown in FIG. 2A after expansion showing no damage to the coating.
[0036] FIG. 3A is a micrograph of a stainless steel (316L) stent coated with continuous EPD-HA thin film.
[0037] FIG. 3B is an about 4×6 μm magnification of the sector indicated by the rectangle of FIG. 3A .
[0038] FIG. 4A is a micrograph of a stainless steel (316L) stent coated with continuous ECD-HA thin film.
[0039] FIG. 4B is an about 65×88 μm magnification of the sector indicated by the rectangle of FIG. 4A .
DETAILED DESCRIPTION OF THE INVENTION
[0040] Throughout the following description specific details are set forth in order to provide a more thorough understanding of the invention. However, the invention may be practiced without these particulars. In other instances, well known elements have not been shown or described in detail to avoid unnecessarily obscuring the present invention. Accordingly, the specification and drawings are to be regarded in an illustrative, rather than a restrictive, sense.
[0041] The invention in one embodiment is directed to implantable medical devices with a flexible thin film calcium phosphate bio-compatible and bio-resorbable coating that has the ability to act as a high capacity drug carrier. Such CaP coatings have no side-effects during coating dissolution into body fluids, and can be designed with a high level of control of coating dissolution rate and microstructure, which also determine the drug retention and release characteristics.
[0042] Of all the types of implantable medical devices that exist, the coronary stents utilized in balloon angioplasty procedures provide a useful model for testing the effectiveness of sol-gel deposited thin flexible CaP coatings on such stents due to the fact that such stents are designed to be flexible. The use of such stents in the examples below should not, however, be considered as limiting the application of the CaP coatings described only to stents. The invention has broad application to virtually any type of body implantable device.
[0043] We have determined unexpectedly that the intrinsic brittle behaviour of CaP ceases to limit the system strain capability if the strongly bonded coating is sol-gel deposited and is thinner than approximately 0.001 mm. Experiments involving repeated contraction/expansion of such thin CaP sol-gel coated stents reveal that there is no separation of the coating from the stent, nor visible damage to the coating, if the coating is thinner than about 0.001 mm and is strongly bonded to the substrate (the tensile bond strength should be larger than about 40 MPa, as measured in model strength experiments according to ASTM C-633 standard).
[0044] In addition, we have discovered that if the novel sol-gel process for deposition of calcium phosphates, in particular hydroxyapatite (HA) synthesis (as previously disclosed in our U.S. Pat. No. 6,426,114 B1, Jul. 30, 2002, “Sol-Gel Calcium Phosphate Ceramic Coatings and Method of Making Same”, by T. Troczynski and D. Liu) is used, the resulting thin flexible coating has controlled porosity which may be utilized to retain drugs within the coating, and release the drugs at a controlled rate.
[0045] The invention pertains to a sol-gel (SG) process for synthesis of calcium phosphate, in particular, hydroxyapatite (HA), thin film coatings on implantable medical devices. The process allows the HA to be obtained in a controlled crystallized form, at a relatively low temperatures, i.e. starting at ≈350° C. This is an unexpectedly low crystallization temperature for HA sol-gel synthesis. The process provides excellent chemical and physical homogeneity, and bonding strength of HA coatings to substrates. The low process temperature avoids substrate metal degradation due to thermally-induced phase transformation, microstructure deterioration, or oxidation.
[0046] Disclosed herein is a method wherein uniform films of hydroxyapatite by the electro-phoretic deposition (EPD) method (EPD-HA) are deposited on complex stent surface, and there is no need to pursue sintering in excess of 500° C. to achieve substantial structural integrity of the film and its high bonding strength to the metallic substrate. In this method, the first step is the well-known EPD of the HA film, for example as disclosed in U.S. Pat. No. 5,258,044, using suspension of sub-micrometer particles of HA in water. This film is dried and then heat treated at 500° C. for 10-60 minutes to initiate sintering of HA. The film is still too weak and too poorly bonded for practical use as a coating on stent or other medical device or implant, but is sufficiently strong to survive the subsequent processing step comprising impregnation by aero-sol-gel HA droplets. The droplets penetrate porosity of the previously deposited EPD-HA, strongly aided by the capillary suction. Thus, majority of the pores of the EPD-HA film are penetrated by the sol-gel precursor of HA, all the way to the metallic substrate. This composite film can be now dried and sintered at a relatively low temperature or 400-500° C., due to the very high activity of the sol-gel component of the film. The sol-gel film bonds the particles of HA deposited by EPD, and bonds well to the metallic substrate during the heat treatment Thus, both the film uniformity (due to EPD process) and low-temperature sinterability (due to sol-gel process) have been achieved. This novel and inventive hybrid technology for uniform HA coatings on stents has the ability to produce films in thickness range from about 1 micron to above 100 microns, with porosity in the range from about 10 vol % to about 70 vol %. Such porous thick HA films are excellent carriers for drugs loaded through impregnation into open porosity of the film. Details of such hybrid process, and its several variants, for preparation of HA films on stents, are given in the examples below.
[0047] Problems with drug delivery in vivo are frequently related to the toxicity of the carrier agent, the generally low loading capacity for drugs, and the aim to control drug delivery resulting in self-regulated, timed release. With the exception of colloidal carrier systems, which support relatively high loading capacity for drugs, most organic systems deliver inadequate levels of bioactive drugs. Sol-gel films heat-treated at relatively low temperatures closely resemble the properties of colloidal films, in terms of accessible surface area and porosity size.
[0048] The sol-gel process according to the invention allows the calcium phosphate to be obtained in a crystallized form, at relatively low temperature, i.e. approximately 350-500° C. Variation of the heat treatment temperature and time provides for control of coating crystallinity (i.e. a more amorphous, more easily resorbable coating can be processed at lower temperatures) as well as coating porosity (higher porosity and smaller average pore size at lower temperatures). Variation of Ca/P ratio in the sol-gel precursor mix allows one to obtain various calcium phosphate phases, for example, hydroxyapatite, dicalcium phosphate, tricalcium phosphate or tetracalcium phosphate.
[0049] The invention in one embodiment is directed to a sol-gel process for preparing calcium phosphate, such as hydroxyapatite, which comprises: (a) hydrolysing a phosphor precursor in a water or alcohol based medium; (b) adding a calcium salt precursor to the medium after the phosphite has been hydrolysed to obtain a calcium phosphate gel such as a hydroxyapatite gel; (c) depositing the gel on the surface of an implantable medical device; and (d) calcining the calcium phosphate, such as hydroxyapatite, at a suitable elevated temperature and for pre-determined time to achieve desired crystallinity, bonding and porosity characteristics for the coating on the device. The deposition of the gel can be done by any number of methods, such as aero-sol deposition, dip-coating, spin-coating, electrophoretic deposition.
[0050] In a preferred embodiment, the phosphor precursor can be an alkyl phosphite and the alkyl phosphite can be triethyl phosphite. Further the calcium precursor can be a water-soluble calcium salt and the water soluble calcium salt can be calcium nitrate. The crystallized calcium phosphate can be calcined at a temperature of at about 350° C. or higher. The metallic implantable medical device can be stainless steel, cobalt alloy, a titanium substrate or other metallic alloy substrate.
[0051] We have discovered that if certain specific characteristics of the calcium phosphate coatings are maintained, the coatings become highly flexible while maintaining their chemistry, high bio-compatibility, and bio-resorbability. The most important characteristics are (a) coating thickness, and (b) the strength of the coating bonding to the metallic substrate. We have repeatedly demonstrated (refer to the examples below) that if CaP coating thickness is maintained below about 0.001 mm, and its bonding strength to the metallic substrate is above approximately 40 MPa, the substrate-coating system retains the strain capabilities of the substrate alone, i.e. the system maintains its integrity during deformation.
[0052] Furthermore, we have discovered that thicker CaP coatings deposited discontinuously on metallic substrate, i.e. in the form of separate “islands” and “patches” approximately 1-100 μm in diameter, retain high resistance against substrate deformation. Our experiments have shown that stents coated with such 1-100 μm patches, about 1-10 μm thick, can be crimped and then expanded without damage to the patches of ceramic. These patches can be deposited on the substrate through a variety of methods discussed above, such as BM-HA, ECD-HA, CPC-HA (all at room or near-room temperature), or EPD-HA, SG-HA and combinations thereof (these two techniques including heat treatment at elevated temperatures). These coating deposition techniques are illustrated in the following examples. The discontinuous CaP film coated medical implant may have some fraction of an area of the metallic substrate exposed to living tissue, which may again lead to the adverse tissue reaction described above. This problem can be avoided by combining discontinuous CaP films with a continuous bio-compatible and non-thrombogenic polymer. Thus, a composite CaP-polymer coating on medical implant is the result. Furthermore, a thin (<0.001 mm) continuous CaP coating can be combined with a thicker discontinuous CaP coating.
[0053] The effects of this process (described in detail in the Examples) are shown in the representative FIGS. 1 and 2 . FIG. 1A illustrates stainless steel (316L) stent coated with discontinuous ASG-HA thin film; FIG. 1B is a magnification of the sector of (A) indicated by the rectangle. FIG. 2A illustrates a stainless steel (316L) stent coated with discontinuous ASG-HA thin film and crimped, with no damage to the coating. FIG. 2B is the same stent after expansion, showing no damage to the coating.
[0054] Our discovery of flexible continuous/discontinuous CaP films or CaP/polymer films opens up a range of new applications of highly biocompatible Cap coatings for medical implants, particularly, but not limited to those that require deformation capability such as coronary stents.
[0055] A sol-gel (SG) process provides superior chemical and physical homogeneity of the final ceramic product compared to other routes, such as solid-state synthesis, wet precipitation, or hydrothermal formation. The SG process allows the desired ceramic phase, e.g. thin film CaP coating, to be synthesized at temperatures much lower than some of the alternate processes. In the SG coating process substrate metal degradation due to thermally induced phase transformations and microstructure modification or oxidation, is avoided. SG widens green-shaping capability, for example, and it is a very convenient method for deposition of thin ceramic coatings.
[0056] Sol-Gel deposition of HA (SG-HA) films at elevated temperatures (350-500° C.) was disclosed previously in U.S. Pat. No. 6,426,114 B1. Sol-gel (SG) processing of HA allows molecular-level mixing of the calcium and phosphor precursors, which improves the chemical homogeneity of the resulting calcium phosphate. The crystallinity of the calcium phosphate phase can be enhanced by appropriate use of water treatment during processing. Variation of Ca/P ratio in the sol-gel precursor mix allows one to obtain any of a number of calcium phosphate phases, for example, hydroxyapatite, dicalcium phosphate, tricalcium phosphate or tetracalcium phosphate. The versatility of the SG method provides an opportunity to form thin film coatings, either continuous or discontinuous, in a rather simple process of dip-coating, spin-coating or aero-sol deposition.
[0057] A high degree of HA crystallinity is frequently required for longer-term bioactive applications, because partially crystalline, or amorphous calcium phosphate, such as HA, coatings are rapidly resorbed by living tissue. For the presently disclosed application of thin HA films on implantable medical devices, control of crystallinity of the HA coating is possible through variation of the time/temperature history during processing. This allows control of the coating resorption rate and thus rate of release of the drugs impregnated into microporosity of the coating.
[0058] Ceramics produced by sol-gel processing can be designed to include high fraction of pores, with well-defined (narrowly distributed) pore size. This is a consequence of the chemical route to the final oxide ceramic produced through SG. Only a small fraction of the original precursor mass is finally converted to the ceramic oxide, the remaining fraction being released during heat treatment, usually in the form of gas, is usually as a combination of water and carbon dioxide. Thus, the released gases leave behind a large fraction of porosity, up to 90% in some instances, depending on the drying conditions and heat treatment time and temperature. These pores can be as small as several nm in diameter, again depending on the drying conditions and heat treatment time and temperature. Effectively, the accessible surface area of such sol-gel derived oxide ceramics can reach several hundred square meters per gram of the oxide, making it an excellent absorbent of gas or liquid substances, or solutions. For example, the average pore size in sol-gel HA treated at relatively low temperature of 400° C. is about 5 nm in diameter, with 90% of pore diameters falling within the range of 1-30 nm. This unique porosity characteristic is widely utilized to produce desiccants, filters and membranes of sol-gel derived ceramic. In this respect sol-gel derived ceramic oxides have a great advantage over polymers, which are in general difficult to process to possess high porosity and high accessible surface area. In the present invention, we utilize this unique property of sol-gel derived CaP coatings on medical implants, especially stents, possessing high accessible surface area to make it a high-capacity drug carrier.
[0059] In the text of this application, it is understood that when appropriate, the term “calcium phosphate” (CaP) is used generically and includes minerals such as hydroxyapatite, dicalcium phosphate, tricalcium phosphate, tetracalcium phosphate and amorphous or partially amorphous calcium phosphate. Studies on the sol-gel route to thin film calcium phosphate coatings on implantable medical devices, particularly stents, performed by the inventors have led to an unexpected break-through in process development. The method according to the invention has produced CaP coatings after heat treatment in air, starting at about 350° C. We have unexpectedly discovered that the film is highly flexible if it is thinner than about 0.001 mm, thereby allowing damage-free manipulation of a CaP coated deformable implantable medical device, for example the contraction and expansion of a CaP coated stent. Preferably, the coating has a thickness between about 0.0001 and 0.001 mm. Furthermore, in this application, we have discovered that the film can accept drugs into its fine porosity, thereby allowing it to address the adverse phenomena related to common medically implanted devices, i.e. the restenosis that occurs after placement of a coronary stent in a blood vessel.
[0060] The calcium phosphate coating according to the invention has been deposited on stents and other metallic surfaces using variety of techniques, including dip-coating, spin-coating, aero-sol deposition electrophoretic deposition. The coatings were deposited on stents made of 316L stainless steel and tubes, and on other metallic substrates including cobalt-iron alloy and titanium.
EXAMPLES
[0061] To demonstrate the feasibility of the unique processing concepts outlined above, the following examples are described below for stainless steel substrate and coronary stents. The procedures outlined below can be applied to other implantable medical devices.
Example 1
[0062] In the first stage of the process, phosphite sol was hydrolysed in a water-ethanol mixture (a concentration of 3M) in a sealed beaker until the phosphite was completely hydrolysed (which is easily recognized by loss of a characteristic phosphite odour), at ambient environment. A Ca salt (2M) was then dissolved in anhydrous ethanol, and the solution was then rapidly added into the hydrolysed phosphite sol. The sol was left at ambient environment for 8 hours, followed by drying in an oven at 60° C. As a result of this process, a white gel was obtained. For the sol containing Ca/P ratio required to produce HA, the gel showed a pure (single phase) apatitic structure with a Ca/P ratio of 1.666, identical to stoichiometric HA, after calcining at a temperature as low as 350° C. Varying the Ca/P ratio allows other calcium phosphates, such as dicalcium phosphate (Ca/P=1) or tricalcium phosphate (Ca/P=1.5), to be obtained. A coating produced using this process, and applied to 316 SS substrate, showed adhesive strength of about 40 MPa after curing at a temperature<450° C. The coating was crack-free and porous.
Example 2
[0063] In another variant of the process, a pure water-based environment was used. The aqueous-based sols were prepared in the same manner as described above in Example 1 for the ethanol-based system. A higher rate of hydrolysis of the phosphite sol was observed. The mixed sol was dried while stirring. After 8 hours aging, a white gel appeared. For the sol containing a Ca/P ratio required to produce HA an apatitic structure with Ca/P ratio of 1.663, close to stoichiometric HA, resulted after calcining the gel at a temperature of 350° C. Both the ethanol-based and aqueous-based gels showed essentially the same apatitic structure at relatively low temperatures. This invention provides a method of synthesizing the HA ceramics via an aqueous-based sol-gel process.
Example 3
[0064] A CaP coating was deposited on the surfaces of a group of electropolished stainless steel stents through aerosol-gel processing. The stents were first treated in 2.4 N phosphoric acid solution for 10 minutes at 70° C. to clean the surface and produce microroughness for increased bonding of the coating. The treated stents were ultrasonically cleaned and dried. The CaP sol was prepared by (a) hydrolysing a phosphor precursor (phosphite); (b) adding a calcium salt precursor to the medium after the phosphite has been hydrolysed to obtain a calcium phosphate sol such as a hydroxyapatite sol. The sol was atomized into ˜ 4 μm large particles using ultrasonically assisted atomizer, and the resulting aerosol fed into a coating chamber. This specific deposition technique is referred to as Aero-Sol-Gels (ASG) deposition and the resulting hydroxyapatite film as ASG-HA.
[0065] The clean stent was inserted into the coating chamber filled with flowing CaP aerosol-gel for a period of 30 seconds, while maintaining the aerosol flow at 0.1 liter/min and chamber temperature at 50° C. The temperature of the coating chamber affects the deposition mode of the coating, producing a uniform, film like coverage of the surface as evidenced by SEM. The coating was dried at 60° C. and heat treated at 450° C. for 15 min to crystallize CaP to form hydroxyapatite thin film. The procedure produces a thin coating covering uniformly the surface of the stent. The thickness of the coating is measured using ellipsometry in the range of 50-150 nm. The subsequent SEM studies on the crimped and expanded coated stents show no evidence of cracking or delamination of the coating. This proves the reliability of the uniform, thin continuous CaP coating during the deployment and implantation of the stent into the coronary artery.
Example 4
[0066] CaP coating has been deposited on the surface of an electropolished stainless steel stents through aerosol-gel processing (ASG), as described in Example 3. The chamber temperature was maintained at 25° C. The coating was dried at 60° C. and heat treated at 450° C. for 15 min to crystallize CaP to form hydroxyapatite thin film. The procedure explained above produces a coating comprising of isolated island of approximately 2-6 μm in size and 0.1-2 μm in thickness, scattered uniformly on the surface of the stent, and covering about 70% of the surface of the stent, as shown in FIGS. 1A and 1B . Subsequent SEM studies on the crimped and expanded coated stents showed no evidence of cracking or delamination of the coating, as shown in FIGS. 2A and 2B . This proves the reliability of the discontinuous CaP coating of variable thickness during the deployment and implantation of the stent into the coronary artery.
Example 5
[0067] Stainless steel metallic substrates (316L) were coated with a 0.6-0.8 μm thin layer of apatite (ASG-HA) as described in Example 3. One group of samples was annealed at 400° C. for 20 min to achieve crystalline SG-HA(C) film and another group at 375° C. for 60 min to achieve amorphous SG-HA(A) film. These films were used as nucleation site for precipitation of BM-HA film. The SG-HA coated samples were immersed into “simulated body fluid” (SBF) of ionic composition (in units of mmol/l) 142 Na + , 5.0 K + , 2.5 C 2+ , 1.5 Mg 2+ , 103 Cl − , 25 HCO 3 − , 1.4 HPO 4 2− , and 0.5 SO 4 2− . The SBF was buffered at pH 7 . 4 with tris(hydroxymethyl)-aminomethane and HCl. This in-vitro static deposition (i.e. the SBF was not renewed during the deposition period) at ˜24° C. produced good quality, dense 3-5 μm thick BM-HA film deposits on flat SG-HA substrates. The crystalline SG-HA(C) film is coated with dense BM-HA, whereas amorphous SG-HA(A) film is coated with porous BM-HA. The properties of the underlying SG-HA surface modification film can be used to vary the properties, e.g. porosity, of the nucleated and deposited top BM-HA film for drug encapsulation.
Example 6
[0068] Stainless steel metallic stents (316L) were coated with −0.1 μm thin CaP coatings as described in Example 3. An inorganic colloidal slurry containing calcium phosphate precursor Ca(OH) 2 and calcium phosphate salt monocalcium phosphate anhydrate, was ball milled in ethanol. The two starting inorganic ingredients had particle size 0.3-2 μm and 0.5-4 μm, respectively. The initial Ca/P ratio in the slurry was kept at 1.5. As dissolution and precipitation are the principal mechanisms for apatite development in such system, 5 wt % of submicron, crystalline hydroxyapatite powder was used as seeds for heterogeneous nucleation of CPC-HA. The thin CaP film surface-modified sample was dip coated in the ethanol suspension of the precursors. After single dip coating, an approximately 10 μm thick layer of porous precursor powder mixture developed on the substrate due to rapid evaporation of ethanol. Due to the colloidal nature of the precursors slurry, this film develops sufficient structural integrity (i.e. strength and hardness) to accept the next processing step. In this step, the film is exposed to sodium phosphate water-based solution (0.25 M), which is allowed to soak into the open pores of the film, and then placed in an incubator at 37° C., 100% relative humidity, for 24 h. During incubation, the colloidal precursors react with the phosphate liquid and precipitate HA. In order to assess the possibility of using this double-coating route for controlled drug release, amethopterin (Sigma Chemicals, USA) was employed as a model drug, in an amount of 5% based on solid phase content of CPC-HA precursors. The drug was mixed with the colloidal suspension of the precursors, before dip coating was performed. During incubation period, 20 μm thick CPC-HA coating precipitated encapsulating the drug molecules within the nanopores of the crystallizing HA. After encapsulation, a drug release study was conducted by immersion of the substrates into 20 ml of phosphate buffer saline (PBS, pH=7.4) at constant ratio of (CPC coating weight)/(volume of PBS) of 1 mg/ml. A reference sample coated with hydrogel film was also tested for drug release kinetics. The hydrogel film was prepared by dipping the CPC-HA layer containing the drug into a polymer solution containing 3% polyvinyl alcohol. After drying, the weight gain of the ˜20 mg CPC-HA layer due to the additional hydrogel coating was ˜0.5 mg, corresponding to the content of polymer film in the CPC-HA matrix of about 2.5%. The samples of PBS liquid with released drug were periodically taken out (i.e. entire liquid was emptied) and refilled with the same amount of 20 ml of PBS. The drug concentration in the supernatant was determined via an UV-Visible spectroscopy. Although a burst effect was detected for both coatings over the initial period of about 8 h, a slower release is evident for the sample post-coated with hydrogel. A linear relationship was obtained between the amount of drug released and (time) 1/2 for the release time greater than 8 h.
Example 7
[0069] The stent was submerged into water-based, diluted suspension of sub-micron particles of hydroxyapatite, containing approximately 2 wt % of HA in the suspension. DC voltage of 5V was applied to the stent, for times varying from 5 seconds, to 10 minutes. As the particles of HA naturally attain positive charge in such solution, they are attracted to the stent surface which is also a negative electrode (cathode) in this system. The buildup of HA particles attracted to the stent (cathode) allows to produce an extremely uniformly coated surface, thickness of the coating varying as a function of time of application of voltage. The film uniformity is the biggest advantage of such Electro-Phoretic Deposition (EPD) processing, which is difficult to reproduce using other methods such as sol-gel processing. For the short time of 10 sec., the EPD-HA coating thickness is about 1 micrometer. This type of EPD-HA coating on 316L stainless steel stent is illustrated in FIG. 3 . For the longer times of several minutes, the coating thickness may exceed 10 micrometers. Thus, in this EPD process, a controlled thickness, uniform HA film may be produced. The as deposited film constitutes loosely bonded particles of HA, of porosity generally in excess of 50 vol %. In order to increase structural integrity and bonding strength to the substrate of such EPD film, heat treatment is necessary at temperatures at least 500° C., for times at least 10 minutes. The heat treatment of EPD films proceeds at higher temperatures and longer times than sol-gel films, because HA particles deposited in the EPD process are less reactive than those deposited in the sol-gel process. The goal of such heat treatment is to increase interparticle bonding, while providing sufficient residual porosity to maintain low stiffness and flexibility of the film, and to provide room for drug impregnation. The need for higher temperature and longer times heat treatment of EPD films is a disadvantage, as the heat treatment process may adversely affect properties of the metallic substrate of the stent.
Example 8
[0070] The HA was deposited on a 316L stainless steel stent surface through EPD process as described in the Example 7. The uniformly deposited EPD film was heat treated at 500° C. for 10 minutes to achieve minimal structural integrity of the film, sufficient to survive handling and preventing re-fluxing of the film upon contact with liquid medium. Such EPD-coated stent was exposed to droplets of sol in the aero-sol-gel process described in Example 3. The sol droplets have penetrated open porosity of the EPD film, and, by capillary attraction, located themselves mostly within negative curvature of the necks between EPD deposited HA particles. Such composite coating was heat treated again at 500° C. for 10 minutes. Now the active sol-gel component of the coating allowed achieving high structural integrity of the film, while EPD component of the coating allowed achieving high uniformity of coverage by the film. A uniform, porous HA film was achieved in this novel combined process.
Example 9
[0071] The electrochemical deposition (ECD) of hydroxyapatite HA has been conducted in the mixed aqueous solution of Ca(NO 3 ) 2 4H 2 O and NH 4 —H 2 PO 4 . In this process HA is deposited on the cathodic (negatively biased) surface of stent or implant by the following reaction: 10Ca 2+ +6PO 4 3− +2OH→Ca 10 (PO 4 ) 6 (OH) 2 ECD was conducted in the mixed aqueous solution of 0.02329 M Ca(NO 3 ) 2 4H 2 O and 0.04347 M NH 4 H 2 PO 4 . The stainless steel specimen, i.e. stent, was the cathode, and platinum was used as the anode. The pH was controlled at 4.0 with the addition of sodium hydroxide. The environment temperature was controlled at 40° C.±1° C. The coating morphology deposited at low current density (1 mA/cm 2 ) was a thin uniform porous structure, 1-2 micrometers thick for deposition time of 0.5-1 minute, as illustrated in FIG. 4 .
Example 10
[0072] The HA was deposited on a 316L stainless steel stent surface through ASG-HA process as described in the Example 4. The discontinuous network of HA patches left some of the stent surface uncoated. 5V DC bias voltage was applied to such pre-coated stent, and the stent submerged into suspension of submicron HA particles. The uncoated metallic surface of the stent preferentially attracted HA particles leading to preferential electrophoretic deposition (EPD) of HA in these areas, to build the coating about 1 micrometer thick in about 10 seconds. The coated stent was heat treated at 500 C for 10 minutes. The EPD-HA coated areas show increased porosity as compared to ASG-HA coated areas, suitable for impregnation with drug carrying liquid. Such composite engineered HA coating shows unique properties regarding mechanical performance and drug release properties.
Example 11
[0073] The HA was deposited on a 316L stainless steel stent surface through ASG-HA process as described in the Example 3, followed by the process of ECD-HA deposition as described in Example 9, but on top of the already heat treated ASG-HA. Such composite engineered coating allowed to achieve substantially higher bonding strength (as compared to ECD-HA deposited directly on metallic surface), and capability of drug encapsulation during deposition of ECD-HA on top of ASG-HA.
Example 12
[0074] The HA was deposited on two 316L stainless steel stents surface through ASG-HA process as described in the Example 4. The coated stents were evaluated in the standard thromboresistance test in dogs. Minimal thrombosis with a grade of 1 (defined as thrombus found at one location only) was observed in one out of two test sites. In the second test site, no thrombosis (grade 0) was observed.
[0075] The process for coating of calcium phosphate, in particular HA, bioactive ceramics, on implantable medical devices disclosed herein offers the following advantages in comparison to other processes and other coating materials on implantable medical devices:
(1) The coating process, including CaP sol synthesis, can be completed in ambient environment (i.e. air), in less than 24 hours. (2) The thin (<0.001 mm) adhesive CaP coatings exhibit sufficient flexibility to survive substantial strain, e.g. during crimping and expanding of a coated stent, without coating damage or spallation (3) Porous CaP coatings can be produced, with controlled amount and size of the pores, which allows design flexibility in choice and absorption/release characteristics for the drug impregnated into the coating (4) The synthesis requires low temperature (˜350° C.) and short time (<1 hour) of calcination for formation of high quality, highly adhesive CaP coating. Low temperature calcination of the novel CaP coatings on metals permits thermal treatment in an air environment without the risk of metal oxidation and possible property degradation due to microstructural deterioration or phase transformations.
[0080] It will be clear for the person skilled in the art of sol-gel processing that coating deposition parameters, such as time, the flow rate of the aerosol, temperature of the coating chamber or the concentration of the sol-gel solution can be customized for different implantable medical device materials and applications producing various degree of coverage on the surface. Similar manipulation and optimization of process parameters may be applied to other coating methods disclosed, i.e. dip- and spin-coating and electrophoresis, biomimetic coating, electrochemical deposition coating, calcium phosphate cement coating, electrophoretic deposition coating, as well as coating porosity distribution and ratio of the inorganic phase (CaP) to organic phase (biodegradable polymer). These parameters were optimized for the particular CaP coatings on the implantable medical devices described in the foregoing examples.
[0081] It is well known that crystallinity and microporosity of hydroxyapatite directly affects its dissolution rate in body fluids. Different heat treatment regimes and temperatures can be adopted to produce various degrees of crystallinity and microporosity to control the degradation of the coating into the body environment. This advantage is of a great importance where drug delivery capabilities are added to the implantable medical device surface coated with sol-gel derived CaP. Similar deposition process can be applied to coating other metallic surfaces, such as Ti substrates or other alloys, such as Cobalt-Chromium-Nickel-Molybdenum-Iron. A thin uniform thin HA coating is obtained. The results of this experiment provide basic evidence of the feasibility of the as described coating on implantable medical devices composed of non-metallic materials such as polymers.
[0082] The nature of the process for CaP coatings deposition according to the invention is such that it can be easily incorporated into the current production practice of metallic implantable medical devices. The water-based liquid precursors to CaP ceramic coatings, simple deposition technique (e.g. dipping or spin-coating or aerosol deposition or electrophoretic deposition, and others) and low-temperature heat treatment in air make the process not unlike simple painting-curing operation which can be commercialized with relatively small effort.
[0083] As will be apparent to those skilled in the art in the light of the foregoing disclosure, many alterations and modifications are possible in the practice of this invention without departing from the scope thereof. Accordingly, the scope of the invention is to be construed in accordance with the substance defined by the following claims. | This invention relates to novel calcium phosphate-coated implantable medical devices and processes of making same. The calcium-phosphate coatings are designed to minimize the immune response to the implant (e.g. restenosis in stenting procedures) and can be used to store and release a medicinally active agent in a controlled manner. Such coatings can be applied to any implantable medical devices and are useful for a number of medical procedures including (but not limited to) balloon angioplasty in cardiovascular stenting, ureteral stenting and catheterisation. The calcium phosphate coatings can be applied to a substrate as one or more coatings by a sol-gel deposition process, an aerosol-gel deposition process, a biomimetic deposition process, a calcium phosphate cement deposition process, an electro-phoretic deposition process or an electrochemical deposition process. The coating can contain and elude a drug in an engineered manner. | big_patent |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the benefit of U.S. Provisional Patent Application No. 61/838,553, which was filed on Jun. 24, 2013, and which is incorporated by reference herein.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
[0002] The present invention was supported in part by funds from the U.S. government (i.e., NIH Grant No. RO3NS058595, NIH Grant No. R15 NS074404, and the Office of the Assistant Secretary of Defense for Health Affairs through the Peer Reviewed Orthopaedic Research Program under Award No. W81XWH-13-02301), and the U.S. government may therefore have certain rights in the invention.
FIELD OF THE INVENTION OR TECHNICAL FIELD
[0003] The present invention relates to the field of nerve regeneration, in particular to nerve conduits for the regeneration of peripheral nerves.
BACKGROUND OF THE INVENTION
[0004] In the United States, each year more than 700,000 people suffer from peripheral nerve injuries (PNI) that can lead to a lifelong disability, such as paralysis. The most frequent causes include motor vehicle accidents, gunshot wounds, stabbings, and birth trauma.
[0005] Currently, there are two gold standard treatments for nerve repair, which are end-to-end suturing and application of autograft or allograft biological tissue. However, each strategy suffers from a number of limitations. For example, end-to-end suturing cannot be performed when the nerve gap is larger than 1 cm. The use of autograft results in potential donor site morbidity for the patient and can potentially exacerbate the condition. The use of allograft tissue has an associated risk of immunogenicity.
[0006] Recent advances in tissue engineering and biomaterials suggest that there may be other approaches to nerve repair and regeneration that may overcome the limitations associated with harvesting natural tissues. One such approach would be the use of biomaterials to produce natural or synthetic nerve guidance conduits (NGCs). These NGCs may overcome some of the limitations of nerve autograft and allograft methods. The NGCs act as an essential precursor for nerve repair, since they can reduce tension at the suture line, can protect the regenerating axons from the infiltrating scar tissue, and can exhibit a low immune response. Although FDA-approved tissue engineered nerve devices have been available in the market for several years, these implant devices do not possess the proper physical topography or chemical cues for nerve repair and regeneration. Also, most of them are currently limited to a critical nerve gap of approximately 4 cm. To design an optimal NGC for enhancing PNR still remains a challenge.
[0007] Current laboratorial NGCs developed using haptotactic strategies alone are not yet comparable to autograft. For example, multichannel NGCs may have an insufficient cross sectional area and or inhibit cell-cell interaction between each of the individual channels. This may lead to functional mismatches and an insufficient level of regeneration. Controlling the position of inner filament bundles within NGCs has yet to be achieved, despite the fact that the presence of microfilaments has been demonstrated to enhance axonal regeneration and provide contact guidance for the regenerating axons in rats. Alternatively, microfilaments can mislead cell migration which can result in uneven distribution of cells within the NGC. These failures in NGCs may be attributed to the inadequate design of intra-luminal guidance channels/filament, forming incomplete fibrin cables during the initial stages of regeneration. Without the formation of this aligned bridge of extracellular material (ECM), further mechanisms for nerve repair are limited. Therefore, it still remains a challenge to design an optimal NGC for enhancing PNR, when compared to the use of autografts.
SUMMARY OF THE INVENTION
[0008] An embodiment of the present invention provides a fabricated implantable NGC. In some embodiments, the NGC comprises an inner spiral structured porous sheet. Such conduits have the potential to serve as medical devices to treat PNI and restore function to the site of the injury. This may be achieved by the spiral structure's ability to facilitate regeneration of nerve tissues.
[0009] In another embodiment of the present invention, the NGC has an integrated spiral structured porous sheet decorated with surface channels. Such a structure increases the surface area available for cell migration and attachment, and may reduce the length of time needed for recovery. Additionally, such a structure can reduce the wear and tear that is often observed with single lumen tubular NGCs. A highly-aligned set of electrospun fibers are present within the surface channels and on the backs thereof. The presence of aligned fibers in such areas ensures that the regenerating nerve will come into contact with aligned fibers. In order to place and suture the nerve tissue without tension, there are two reserved chambers at the proximal and distal end of the conduit. The chambers allow for nerve stumps to be sutured without tension due to the fact that the chambers provide space to house the nerve in place with an optimal grip. A dense layer of randomly-oriented fibers on the outside of the spiral structure can greatly improve the mechanical properties of the NGC and provides integrated structural support for nerve regeneration. The spiral conduit is tunable such that its length and diameter can be varied controllably depending on how it is to be used. The length and the outer diameter of the conduit depend on the size of its intermediate sheet, which is the spiral structured porous layer of the NGC. The method of fabricating the conduit does not limit its length, thus enabling the application for longer gap repair/regeneration for PNI.
BRIEF DESCRIPTION OF FIGURES
[0010] FIG. 1 is a schematic illustration in cutaway view of a nerve guidance conduit (NGC) according to an embodiment of the present invention bridging the stumps of a damaged nerve;
[0011] FIG. 2 is a schematic end-on cross-sectional view of the NGC of FIG. 1 ;
[0012] FIG. 3 is a scanning electomicrograph (SEM) image of a first side of a portion of a porous polymeric sheet of a type used to fabricate NGCs according to an embodiment of the present invention;
[0013] FIG. 4 is an SEM image of the side opposite the first side of the porous polymeric sheet of FIG. 3 ;
[0014] FIG. 5 is an SEM image of a porous polymeric sheet having aligned nanofibers thereupon according to an embodiment of the present invention;
[0015] FIG. 6 is an SEM image of a porous polymeric sheet having randomly-distributed nanofibers thereupon;
[0016] FIG. 7 is a stereomicroscopic image of the exterior of a second NGC;
[0017] FIG. 8 is stereomicroscopic image of the NGC of FIG. 7 after being sectioned longitudinally;
[0018] FIG. 9 is a stereomicroscopic image of an end-on view of the NGC of FIG. 7 ;
[0019] FIG. 10 is an SEM image of surface channels on a polymer sheet of a type used to fabricate an NGC according to an embodiment of the present invention;
[0020] FIG. 11 is a schematic diagram of a polymer sheet of the type shown in FIG. 10 ;
[0021] FIG. 12 is a group of stress-strain plots generated from tests performed on various NGCs which are embodiments of the present invention;
[0022] FIG. 13 is a bar chart comparing cell proliferation on various NGCs which are embodiments of the present invention;
[0023] FIG. 14 is a plot showing changes in sciatic functional index (SFI) over time for rats having implanted NGCs according to embodiments of the present invention;
[0024] FIG. 15 is a bar chart of compound muscle action potentials (CMAP) for rats having implanted NGCs according to embodiments of the present invention;
[0025] FIG. 16 is a bar chart of nerve conduction velocities (NCV) for rats having implanted NGCs according to embodiments of the present invention;
[0026] FIG. 17 is a bar chart of percent of neural tissue regenerated in sciatic nerves bridged by NGCs according to embodiments of the present invention;
[0027] FIG. 18 is a bar chart comparing muscle weight ratios for the gastrocnemius muscle of rats for which the sciatic nerve was bridged by NGCs according to embodiments of the present invention;
[0028] FIG. 19 is a bar chart comparing muscle fiber diameter for the gastrocnemius muscle of rats for which the sciatic nerve was bridged by NGCs according to embodiments of the present invention; and
[0029] FIG. 20 is a bar chart comparing muscle fiber coverage for the gastrocnemius muscle of rats for which the sciatic nerve was bridged by NGCs according to embodiments of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0030] Embodiments of the present invention provide NGCs with integrated spiral structured porous sheets decorated with surface channels and electrospun fibers. Such NGCs provide superior mechanical strength compared to NGCs in the prior art, along with integrated multiple channels, stable aligned fibrous layers, good inter-cell communication, and high surface/volume ratios within the NGCs. Chambers at the distal and proximal ends of the NGC provide additional space for fitting nerve stumps in order to reduce the tension at the suture line between the NGC and the nerve stump. A dense outer fibrous tube on the outside of the spiral structured porous sheet can prevent the infiltration of scar tissue while the regeneration process takes place. One embodiment of the NGC of the present invention comprises a three-dimensional (3-D) spiral structured porous sheet having two chambers at the ends thereof. The spiral structure includes a highly porous polycaprolactone (PCL) sheet, which may be formed as a spiral-wound sheet using known methods and decorated with surface channels on a surface of the spiral wound sheet, coated with a thin layer of aligned electrospun fibers on the surface channels, and a dense randomly-oriented fibrous tube on the outside of the NGC. Other bioresorbable materials known for use in the biomedical arts may be used in place of PCL for the sheet and fibers (e.g., collagen/PCL blends for the fibers).
[0031] Other embodiments of the present invention provide a process for fabricating an implantable NGC, such as the embodiment of an NGC described above, which can be used as a medical device for facilitating the repair and regeneration of nerve tissues.
[0032] Several features of NGCs according to embodiments of the present invention are discussed herein below.
[0000] 1. Three-Dimensional (3-D) Integrated Spiral Structured Porous Sheet with Proximal and Distal Reserved Chambers
[0033] Collagen tubes, which have been approved by the FDA, lack sufficient mechanical strength to support nerve regeneration. As for multi-channel NGCs, the major drawback is that cells/axons in each channel do not interact well with those in the other channels, which adversely affects nerve regeneration and would affect nerve function recovery even if the nerve gap were bridged. In comparison, the integrated spiral structure makes the NGC of the present invention superior to those in the prior art in that mechanical properties are greatly improved and favorable for inter-cellular interaction and neural myelination. This is important for nerve regeneration because of the time required for nerve regeneration to bridge large nerve gaps. Further, a NGC should have enough mechanical strength to provide structural support to the nerve during regeneration. Also, the proximal and distal chambers in the ends of the NGC provide an optimal initial environment for nerve ingrowth. These chambers can prevent stress from accruing when the nerve tissue is sutured with the conduit in an end-to-end fashion. Moreover, the increased surface/volume ratio and the highly porous intermediate layers of the PCL sheet are preferred for cell attachment and nutrient transportation during nerve regeneration.
[0000] 2. Decorated Surface Channels on the Spiral Porous Sheet with Additional Electrospun Aligned Fibers and and an Outer Fibrous Tube
[0034] Electrospinning is an approach for polymer biomaterial processing that provides an opportunity to control morphology, porosity and composition of an NGC using relatively unsophisticated equipment. Unlike conventional fiber spinning processes that produce fibers with diameters in the micrometer range, electrospinning is capable of producing fibers in the nanometer diameter range, which are typically deposited in the form of nonwoven fabrics. Nanofibers provide a connection between the nanoscale and the macroscale world, since, although their diameters are in the nanometer range, the fibers are very long, sometimes having lengths of the order of kilometers. A major problem of all hollow tubes is misdirection of cellular migration: since transected axons produce axon sprouts proceeding in a distal direction, a neuroma is always formed which consists of minifascicles proceeding in an abnormal manner, proliferating Schwann cells (SCs), fibroblasts and capillaries. If there is a directional factor of any kind (e.g., an artificial nerve tube which usually provides no endoneurial structure), the neuroma proceeds in the desired direction. This phenomenon has been called “neuromateous neurotization”. In consequence, only a few dispersed axons are able to enter the right fascicle and endoneurial tube in the distal nerve stump once they have reached the end of the conduit in the interior of the NGC.
[0035] One successful tissue engineering strategy for nerve repair is to create aligned features on the conduit to provide guidance for cell migration and directional axonal regeneration across the glial scar and lesion site in both central nervous system and peripheral nervous system injuries. Such features may include aligned surface channels and electrospun fiber-based conduits for nerve repair, according to embodiments of the present invention.
[0036] Consequently, the construction of a spiral structure conduit with highly aligned surface channels and nano-fibers is very helpful for nerve proliferation and neurite extension. Meanwhile, the intricate aligned structure can also influence the growth and distribution of seeded SCs, which further directs the longitudinal extension of the neural axons. Further, there is a wide range of polymers available that are suitable for deposition on the spiral sheet to meet the individualized specifications for the NGC (e.g., collagen/PCL copolymer nanofibers, rather than pure PCL sheets).
[0037] Fibers spun along the outside of the NGC not only assist in stabilizing the spiral structure, but also inhibit infiltration of scar tissue through the inter-connective pores. By increasing the mechanical strength of the NGC, the risk of structural failure can be minimized, promoting more uniform and natural regeneration of nerve tissue.
Tunable Features of the NGC
[0038] In order to solve the conflict between optimizing the mechanical properties of the NGC and maximizing its length, many techniques may be used to reinforce the NGC. In a method according to an embodiment of the present invention, a spiral conduit (e.g., a spiral structured porous sheet) is placed onto a rotator and a nanofiber is spun in random orientations along the spiral structure to form an outer fibrous tube. The thickness of the outer fibrous tube can be controlled. This dense layer of randomly-oriented fibers deposited on the outside of the spiral conduit can improve the mechanical properties of the entire structure, and meanwhile provide a stable structural support during nerve regeneration. In a method according to an embodiment of the present invention, depositing the outside layer of fibers on the spiral conduit is the final and separate step of fabricating the NGC, so it is practical to modify the polymers used to form the fibers before the electrospinning step. The outer fibrous tube can be made from polymers that are different from that of the spiral sheet or the aligned fibers.
[0039] In another aspect, the process of the present invention is tunable in that the sizes of the spiral conduit are controllable, and both the length and the outside diameter are dependent on the size of the spiral-wound sheet. Therefore, in order to fabricate a spiral conduit with a particular size, (e.g., a length larger than 15 mm, which is the maximum length of nerve regeneration achieved with silicone tubes in rats), it is only necessary to cut a polymer sheet to the appropriate size.
Embodiments of the Present Invention
[0040] FIG. 1 is a schematic illustration in cutaway view of a nerve guidance conduit (NGC) 10 according to an embodiment of the present invention bridging the stumps 12 , 14 of damaged nerve 16 . The stumps 12 , 14 are received in reserved chambers 18 , 20 at the proximal and distal ends 22 , 24 of the NGC 10 , and held in place with sutures 26 , 28 , or by other means known in the art. The reserved chambers 18 , 20 allow the nerve stumps 12 , 14 to be placed in the NGC 10 and sutured without tension by housing the nerve stumps 12 , 14 in place with an optimal grip.
[0041] FIG. 2 is a schematic cross-sectional view of the NGC 10 showing that the NGC 10 includes an outer fibrous tube 30 surrounding one or more spiral wound sheets 32 The fibrous tube 30 includes a dense structure of randomly oriented polymer fibers (not shown). The spiral wound sheets 32 define a lumen 34 inside the NGC 10 . The lumen 34 is bounded by an inner surface 36 of the spiral wound sheets 32 . The NGC 10 further includes an integrated guidance spiral 38 having a plurality of surface channels 40 . The guidance spiral 38 is are composed of multiple layers (e.g., layers 42 , 44 ), and together define a spiral guidance channel 46 within the lumen 34 . In some embodiments of the present invention, the surface channels 40 are arranged such that they are substantially parallel to each other and to a longitudinal axis (not shown) of the NGC 10 . The layers 42 , 44 may be extensions of the spiral-wound sheets 32 , or may be formed separately therefrom, then integrated with the spiral-wound sheets 32 . The plurality of surface channels 40 increases the surface area of the guidance spiral 38 that is available for cell migration and may reduce the length of time needed for nerve regeneration. Additionally, the integrated layers 42 , 44 may reduce the wear and tear that can occur in NGCs known in the art. Such wear and tear is often observed with single lumen tubular NGCs.
[0042] In some embodiments of the present invention, a highly aligned orientation of electrospun nanofibers (not shown) are provided as coats on the surface channels 40 , and on both layers 42 , 44 of the spiral sheet 38 , and dense randomly-oriented fibers are provided on an outer surface 48 of the NGC 10 , which greatly improves the mechanical properties of the NGC 10 , as discussed above. In some embodiments, the aligned fibers are substantially parallel to each other. In some embodiments, the aligned fibers are substantially parallel to a longitudinal axis of the NGC 10 . The presence of aligned fibers ensures that all areas of the regenerating axon will come into contact with aligned fibers.
[0043] The NGC 10 is tunable such that its size can be varied in a controlled fashion depending on how it is to be used. The length and the outer diameter of the NGC 10 are dependent on the size of guidance spiral 38 . An NGC 10 according to the present invention may have any length, thus enabling it to be used to repair long gaps in the axon for the repair or regeneration of peripheral nerves.
[0044] FIGS. 3 and 4 are scanning electromicrograph (SEM) images a first side and a second side opposite the first side of a portion of a porous polymeric sheet 50 of a type that may be used to fabricate the spiral-wound sheets 32 or guidance spiral 38 of an NGC of the same type as NGC 10 , before the application of electrospun nanofibers. Interconnected pores (e.g., pores 52 ) are present throughout the polymeric sheet 50 . FIG. 5 is an SEM image of a porous polymeric sheet 54 of the same type as polymeric sheet 50 , showing aligned nanofibers 56 that have been deposited on the polymeric sheet 54 by electrospinning. FIG. 6 is an SEM image of a porous polymeric sheet 58 of the same type as polymeric sheets 50 , 54 showing randomly-distributed nanofibers 60 that have been deposited on the polymeric sheet 58 by electrospinning.
[0045] FIGS. 7-9 are stereomicroscopic images of an NGC 62 according to an embodiment of the present invention. NGC 62 is of the same general type as the NGC 10 discussed with respect to FIGS. 1 and 2 . FIG. 7 is an image of the intact NGC 62 showing its outer fibrous tube 64 . FIG. 8 is an image of the interior of the NGC 62 after it has been cut lengthwise, showing an interior surface 66 of the outer fibrous tube 64 , the guidance spiral 66 , and the reserved chambers 68 , 70 . FIG. 9 is an end view of the NGC 62 showing the outer spiral wall 64 , the guidance spiral 66 and the channels 72 of the guidance spiral 66 . FIG. 10 is a SEM image of a portion of polymer sheet 74 , which is of a type for making an NGC according to an embodiment of the present invention, showing the substantially parallel alignment of channels 76 , which are separated by ridges 78 .
Exemplary Fabrication Method
[0046] In a method of fabricating an NGC according to an embodiment of the present invention, a polycaprolactone (PCL) sheet was fabricated using a combination of the solvent evaporation method and the salt-leaching method. An 8% (w/v) PCL solution was poured onto a glass petri dish, and acupuncture needles having a diameter of 150 μm were placed on top of the PCL solution to form multi-channels having widths of about 180 μm. The dish was moved to a hood to let it air dry. After an hour, the resulting PCL sheet was immersed into deionized water so that the salt was dissolved, producing pores in the PCL sheet. The needles were also removed, having formed multi-channels on the PCL sheet with widths of about 180 μm. After 30 minutes, the PCL sheet was taken out and dried on a paper towel. Subsequently, 2 hours later, the fully dried PCL sheet was cut into a rectangular shape having dimensions of about 12 mm by 10.5 mm to bridge a 10 mm nerve gap in an animal study.
[0047] Referring to FIG. 11 , in an exemplary embodiment of the method, the cut PCL sheet 80 had opposite longer edges 82 , 84 (i.e., the 12 mm edges), and opposite shorter edges 86 , 88 (i.e., the 10.5 mm edges). It may be noted that the channels 90 are substantially parallel to the longer edges 82 , 84 . Two rectangular areas 92 , 94 were cut out from the opposite corners 96 , 98 of the edge 82 , such that edge 82 was then shorter than edge 84 .
[0048] PCL aligned nanofibers were spun on the cut PCL sheet 80 using a conductible rotation disk method known in the art. A 16% (w/v) solution of PCL in 1,1,1,3,3,3 Hexafluoroisopropanol (HFIP) (Oakwood Products, Inc) was prepared for electrospinning. Aligned fibers were deposited on the 12 mm×10.5 mm PCL sheet longitudinally on the edge of the rotating disk such that the fibers were substantially parallel to channels 90 . The fibers were deposited such that they would be substantially longer than the cut PCL sheet 80 . The sheet was carefully removed from the disk to ensure the fibers deposited remained aligned. The excess lengths of fiber (i.e., the portions of the fibers that extended beyond the edges of the cut PCL sheet 80 were collected and folded onto the back of the cut PCL sheet 80 .
[0049] Turning back to FIG. 11 , the cut PCL sheet 80 with the aligned nanofibers thereon was then wound in a spiral fashion from the edge 82 to the edge 84 , such that the edge 82 was in the interior of the resulting spiral NGC and the channels 90 were substantially parallel to a longitudinal axis of the spiral NGC. In the spiral NGC, the cutaway areas 92 , 94 become reserved chambers (e.g. reserved chambers 68 , 70 of spiral NGC 64 of FIGS. 7-9 , or reserved chambers 18 , 20 of spiral NGC 10 of FIG. 1 ).
[0050] Random nanofibers were then spun onto the outside of the spiral NGC to form an outer fibrous tube on the spiral NGC. The thickness of the outer fibrous tube was approximately 150 μm. The outer fibrous tube is intended to secure the entire spiral structure, enhance the mechanical strength, and prevent tissue infiltration during nerve regeneration. The resulting spiral NGC with its outer fibrous tube was 1.8 mm in diameter and 12 mm in length, suitable for bridging a 10 mm nerve gap.
Tensile Properties of the NGCs of the Present Invention
[0051] FIG. 12 is a plot of stress versus strain for several NGCs fabricated according to a method of the present invention: an outer fiber tube comprising a dense layer of randomly-oriented nanofibers; the outer fiber tube with a spiral sheet therein, and the outer fiber tube with the spiral sheet and aligned nanofibers (“AF”). The following tensile properties were measured: Young's Modulus, percent elongation to failure, and tensile strength of the different NGCs. The Young's Modulus, calculated through the stress-strain curve shown FIG. 12 , ranged between 0.262-0.7625 Mpa. All three of the NGCs yielded a Young's Modulus that can stand force stretching and be applicable for in vivo use. The values reported for the outer fibrous tube and the other NGCs all in a useful range for use in nerve regeneration and repair. High tensile strength will provide a mechanically strong NGC that can be sutured well during coaptation of the nerve stump and NGC, and preserve the suture after surgery. The measured physical properties of the NGCs of FIG. 11 are summarized in Table 1, below.
[0000]
TABLE 1
Tensile Properties of Nerve Guidance Conduits
Young's
Tensile
Modulus (MPa)
% Elongation
Strength (MPa)
Outer Fibrous Tube
0.7625
296.4
8.98
Outer Fibrous Tube +
0.33766
171
2.08
Spiral
Outer Fibrous Tube +
0.32766
301
1.78
Spiral + AF
Porosities of the NGCs
[0052] The measured porosity values for the outer fibrous tube (hereinafter, NGC-T), outer fibrous tube+spiral (hereinafter, NGC-T-S), and outer fibrous tube+spiral+AF (hereinafter, NGC-T-S-AF) were respectively 71.98±1.22%, 75.01±2.69%, and 78.41±3.64%. The differences in porosities for these three types of NGCs are not statistically significant (p<0.05).
Cell Proliferation
[0053] Schwann cells were adopted as the model for evaluation of cellular response on the fiber-based spiral NGCs. At day 4, NGC-T-S-AF showed significantly greater cell proliferation than NGC-T and NGC-T-S. The cell numbers for each type of NGC are shown in FIG. 13 . The degrees of cell proliferation for the NGC-T and NGC-T-S are significantly lower (p<0.05) than for the NGC-T-S-AF.
Implantation of NGCs
[0054] The NGCs were tested in a 10 mm Sprague Dawley (SD) rat sciatic nerve defect to evaluate the effect of nanofibers on peripheral nerve regeneration through porous spiral NGCs. The sciatic nerve of each rat was cut, then bridged with one of the NGCs. One group received an autograft rather than a NGC. One group received no grafts. All rats were in good condition during the survival weeks. There were no obvious signs of systemic or regional inflammation and surgical complications after implantation
[0055] The recovery of motor function was assessed based on the walking track evaluation Referring to FIG. 14 , normal sciatic functional index (SFI) value of −9.4±1.4 was measured from all healthy rats (n=30) before surgery. All experimental animals had decreased SFI of values between −85.6 and −94.5 (n=30) by week 2 after surgery. During the initial 4 weeks, there was no significant improvement in any of the groups. At 6 weeks after surgery, the overall SFI reached the levels between −72.2 and −91.7, which was equivalent to an improvement of 2.8-13.4 index points from week 2. Each group's 6-week SFI value was recorded as follows: autograft (−72.2±6.6), T-S-AF (−81.5±3.2), T-S(−88.4±4.9), and T (−91.7±4.2). The autograft SFI revealed a significant difference (p<0.05) as compared to the T-S and T groups. The SFI in the T-S-AF group was significantly higher than for the T groups (p<0.05).
[0056] Functional recovery was further evaluated with electrophysiological assessment to determine whether functional recovery occurred through the NGCs. Six weeks post-surgery, compound muscle action potentials (CMAP) were evoked by stimulation at the surgical limbs and recorded from gastrocnemius muscle following by measurements of amplitude and nerve conduction velocity (NCV). Signals were absent and no muscle contractions were observed in the non-grafted group. Referring to FIG. 15 , for the amplitude measurements, each group's value was recorded as follows: autograft (5.25±1.51 mV), T-S-AF (4.96±1.58 mV), T-S(3.6±1.39 mV), and T (2.0±0.64 my). Significant differences in amplitude were observed in the T group as compared to the autograft and T-S-AF groups (p<0.05). However, the difference between the autograft, T-S-AF, and T-S groups (p>0.05) was not statistically significant. Similar results were found in NCV measurement: autograft (31.57±4.13 m/s), T-S-AF (26.47±6.87 m/s), T-S (18.28±4.16 m/s), and T (13.3±5.65 m/s) (See FIG. 16 ). Significant differences in NCV were observed in the autograft group as compared to the T-S and T groups (p<0.05). The NCV result in the T group also showed a significant difference as compared to autograft and T-S-AF groups (p<0.05). However, there were no significant differences when the NCV values of the autograft group were compared to those of the T-S-AF group, which may indicate that nanofibers can accelerate the level of muscle reinnervation as well as autograft.
[0057] After 6 weeks post-surgery, the distal nerve segment from each group was explored and carefully isolated from the surrounding tissues. A pinch reflex test was performed distally. A reflex movement of the back muscles indicates that the sensory fibers are positively regenerated through the NGCs, while no movement was considered as lack of sensory fibers in the NGCs. The results are presented in Table 2, below.
[0000]
TABLE 2
Pinch Test Results
Number of rats
responding to pinch test
(n = 5)
Autograft
5/5
T-S-AF
5/5
T-S
4/5
T
3/5
[0058] Further histological evaluations of nerve regeneration behavior with NGCs were investigated under a light microscope. The results clearly demonstrated the potential of the NGCs of the present invention to house a large number of supportive cells, both with and without nanofibers to enhance the surface area of the channel. The NGCs possessed durable mechanical strength to support the entire regeneration process. Low magnifications of micrographs showed that neural tissues, including myelinated axons and myelin sheath, were all successfully presented among the groups. Angiogenesis occurred through which new blood vessels were formed during the nerve regeneration process. Normal axons were nearly all surrounded by uniform thicknesses of myelin sheaths and presented large fiber diameters. Nevertheless, the studied groups presented premature morphologies (i.e., diverse nerve fiber sizes and thinner myelin sheaths).
[0059] Quantitative analysis of the total occupied neural tissue coverage in the NGCs compared to those of normal rat nerves (70.57±3.81%) further confirmed the above findings. Referring to FIG. 17 , each group's value was recorded as follow: autograft (29.29±4.61%), T-S-AF (26.52±3.77%), T-S(17.37±2.97%), and T (5.88±1.43%). No significant differences were found among autograft and T-S-AF groups. However, the area occupied by neural tissue in T-S group showed significantly lower values than the autograft, and T-S-AF groups. High significance was observed in the T group as compared to the other groups (p<0.01). Finally, it should be noted that the cross-sectional micrograph of T group was covered with a large white area. That implied the single lumen repair limited the nerve regeneration.
[0060] When severe nerve injury occurs, the muscle is denervated and the balance of muscle metabolism could be shifted from protein synthesis toward protein degradation. As a consequence, the target muscle presents a decreased muscle cell size, muscle weight loss, hyperplasia of connective tissues, and new blood vessel formation. To evaluate the reinnervation of the gastrocnemius muscle, Masson trichrome staining was applied to the section followed by measurements of muscle weight ratio, diameter of muscle fibers, and muscle fiber coverage per cross section. Referring to FIG. 18 , for comparisons of muscle weight ratio, each group's value was recorded as follows: autograft (39.73±4.19%), T-S-AF (25.64±3.01%), T-S(22.31±2.18%), and T (19.2±2.03%). The muscle weight ratio of the autograft group was greater than that of the other groups by a statistically significant amount (p<0.05). However, there were no significant differences between the T-S-AF and T-S groups (p>0.05). The T group revealed a significant lower ratio than the T-S-AF group.
[0061] Referring to FIG. 19 , for comparisons of muscle fiber diameter, each group's value was recorded as follows: autograft (34.62±1.05 μm), T-S-AF (31.81±2.18 μm), T-S(25.5±6 μm), and T (21.56±2.98 μm). Although the autograft group showed a significant difference from the T-S and T groups, it was not significantly higher than the T-S-AF group. Also, there were no significant differences between the T-S and T groups (p>0.05). Further findings showed that the value for the T group was significantly lower than that for the autograft, and T-S-AF groups.
[0062] Referring to FIG. 20 , for comparisons of muscle fiber coverage, each group's value was recorded as follows: autograft (96.84±4.1%), T-S-AF (93.72±4.63%), T-S (86.99±10.31%), and T (58.42±4.69%). There were no significant differences between the values for the autograft, T-S-AF, and T-S groups (p>0.05); however, they were all significantly greater than the value for the T group (p<0.05).
[0063] From qualitative analyses and histological observations discussed above, spiral NGCs of the present invention, with or without nanofibers, revealed the potential to prevent muscle atrophy as well as the effect of autograft. Both the surface channels and the aligned fibers provide good topographical cues for nerve regeneration, and thus allow muscle reinnervation faster than single lumen NGCs, thus suggesting that the surface channels and nanofibers further assisted NGC structures in promoting nerve regeneration.
[0064] It should be understood that the embodiments described herein are merely exemplary in nature and that a person skilled in the art may make many variations and modifications thereto without departing from the scope of the present invention. All such variations and modifications, including those discussed above, are intended to be included within the scope of the invention, as defined by the appended claims. | A nerve guidance conduit includes a spiral structured porous sheet decorated with channels on its surface and electrospun nanofibers in a parallel alignment with the channels and an outer tubular structure including randomly-oriented nanofibers. Such a structure provides augmented surface areas for providing directional guidance and augmented surfaces for enhancing and peripheral nerve regeneration. The structure also has the mechanical and nutrient transport requirements required over long regeneration periods. To prepare a nerve guidance conduit, porous polymer sheet is prepared by a solvent casting method while using a template of thin rods to form parallel channels on a surface of the sheet. Aligned nanofibers are deposited on the sheet parallel to the channels. The polymer sheet is then wound to form a spiral structure. A dense layer of randomly-oriented nanofibers may be deposited on the outside of the spiral. | big_patent |
FIELD OF THE INVENTION
This invention is in the field of seat base support assemblies. It relates to seat base support assemblies for furniture or the like wherein the support assemblies employed are of the non-coil spring type; i.e., they comprise sinuous spring bands, wire grids or chord-rubber webbing, or are made up of flexible steel bands. The invention finds particularly advantageous application to sinuous band seat spring assemblies, however, and is discussed initially in that context.
BACKGROUND OF THE INVENTION
Over the past ten to twelve years furniture seat spring torsioning devices such as disclosed in U.S. Pat. No. 3,210,064, No. 3,388,904, and No. 3,525,514, met the industry's long sought need for deep-drop uplift at the back rail and also contributed in other ways to the luxury seat which evolved during that time frame. As eleven (11) gauge helical spring connectors became disproportionally more expensive during this period these devices have been used almost exclusively with SWING ANCHOR connecting links and radius links such as disclosed in U.S Pat. No. 3,790,149, and depended upon kinetic energy stored in the arced sinuous spring itself to produce all upward resilience. The upholstered furniture styles most widely sold at the time developed all the back rail uplift considered desirable using such connecting links.
During the past three to four years, however, there has been a move toward the use of thicker and thicker cushions. Attractive new and thicker cushion materials, including foam rubber laminates, have necessitated the lowering of seat frame heights dramatically. As a result, an urgent need was created in such constructions for more upward resilience of a strong dynamic nature in the spring base.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a new and improved rail connector for sinuous spring bands, wire grids, chord-rubber webbing, and flexible steel bands.
Another object is to provide a rail connector which embodies the salutary features of conventional helical spring connectors while retaining essentially none of the undesirable features thereof.
Still another object is to provide a rail connector which produces spring torsioning and dynamic uplift at the back rail through kinetic energy which it itself stores, and which then cooperates with any spring action in the seat base support assembly, which might be sinuous, arced, or de-arced, a wire grid, chord-rubber webbing, or flexible steel bands.
Yet another object is to provide such rail connectors which give varying degrees of dynamic uplift resilience obtained by offering alternative spring action modes within themselves.
The foregoing and other objects are realized in accord with the present invention by producing two related forms of rail connector. A first form uses pre-stressed, close wound coil spring with attachment arms. In one alternative the coil spring is wound on an axis transverse to the axis of spring expansion and contraction while in another alternative the coil spring is wound on an axis longitudinally arranged relative thereto. In either alternative the connector may selectively have a leverage-amplified torsioning capability.
A second form uses a pre-stressed, cantilever spring configuration. This connector may selectively be used with a sinuous spring band having leverage-amplified torsioning incorporated therein.
The invention for the first time provides seat spring-enhancing connectors that in themselves combine the four essential seat-force-generators; i.e., (1) torsioning; (2) dynamic uplift; (3) expansion-contraction; and (4) leverage-amplification. These, in turn, produce to the greatest degree the four most desired seat-performance characteristics; i.e., (1) initial-drop; (2) deep-drop; (3) softness without "oil canning", "bucketing", "jack-knifing", or "bottoming"; and (4) resilient uplift proportionate to load.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention, including its construction and modes of operation, together with additional objects and advantages thereof, is illustrated more or less diagrammatically in the drawings, in which:
FIG. 1 is a vertical sectional view through a portion of the back end of a furniture seat spring base, illustrating a spring band assembly including a first form of rail connector embodying features of the present invention;
FIG. 2 is a view taken along line 2--2 of FIG. 1;
FIG. 3 is a view similar to FIG. 1 illustrating one modification of the first form of rail connector embodying features of the invention;
FIG. 4 is a view similar to FIG. 1 illustrating another modification of the first form of rail connector embodying features of the invention;
FIG. 5 is an enlarged view of a portion of an alternative first form of rail connector embodying features of the invention;
FIG. 6 is a view similar to FIG. 1 illustrating a second form of rail connector in a spring band assembly embodying features of the invention;
FIG. 7 is a view taken along line 7--7 of FIG. 6;
FIG. 8 is a view similar to FIG. 7 illustrating the second form of rail connector in a sinuous spring band assembly embodying features of the invention; and
FIG. 9 is a view similar to FIG. 7 illustrating the second form of rail connector in another sinuous spring band assembly.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, and particularly to FIGS. 1 and 2, a portion of the back end of a furniture seat base is illustrated generally at 10. The seat base 10 comprises spring band assemblies 15, only one of which is shown, extending in parallel relationship between the front rail (not shown) and back rail 16 of the base frame. Each assembly 15 includes a normally arced sinuous spring band 20 of standard loop size; i.e., a seven-eighths (2/3) inch interval between linear segments 25 and semi-circular segments 26 of the band. Each band 20 is connected to the back frame rail 16 by a first form of rail connector 30 embodying features of the invention.
The rail connector 30 is fabricated of eleven (11) gauge wire, similar to standard helicals. It comprises a section 35 of three coils tightly wound on an axis transverse to that of the band 20 and the axis of expansion and contraction of the connector 30.
Extending from the coil section 35, at their uppermost extremity, tangent to the arc of the coils and in opposite directions, are a rail-attachment leg 38 and a spring-attachment leg 39. The rail-attachment leg 38 terminates in a transversely disposed anchor section 40 which seats in a conventional "G" clip 41, while the spring-attachment leg 39 seats on and grips the spring band 20.
The spring attachment leg 39 is inclined slightly upwardly from the horizontal, in contrast to the rail-attachment leg 38, and includes an upwardly formed shoulder 45 and a terminal hook 46. The shoulder is formed approximately mid-way between the hook 46 and tangency with the coil 35, seven-eighths (2/3) inches each way in the case where the band 20 is regular sinuous.
As seen best in FIG. 1, the downwardly opening hook 46 is designed to seat over the penultimate linear segment 25b in the spring band 20, while the ultimate linear segment 25a seats against the shoulder 45. The result is to lock the end of the band 20 and the connector 30 together.
In operation, the attachment-arm 39 reaching up into the band 20 sets up a torsioning effect in the back of the band. The arm 39 is spring loaded upwardly by the strength of the coil section 35 and produces dynamic uplift. At the same time the coil section 35 permits of longitudinal expansion-contraction of the connector 30. The coil section 35 and rail-attachment leg 38 extending outwardly of the band 20 end amplify the leverage induced torque.
In an alternative construction of the first form of the invention, as seen in FIG. 3, the rail connector 130 is attached to the rail 116 through a gang bore 142. The rail-attachment leg 138 of the connector has a shorter anchor section 140 which can pass through the bore 142 from front to back of the rail 116 and then seats against the back of the rail to lock the connector 130 to the rail.
The spring-attachment leg 139 in this form of the connector is much shorter and has an upwardly formed hook 146 at its inner end. The hook 146 is so formed that when it seats upwardly, onto the ultimate linear segment 125a of the spring band 120, it cannot slip off during seat base operation.
The connector 130 provides both dynamic uplift and resilient expansion-contraction at the band end. It does not induce torsion or leverage amplification.
The connector 130 can also be connected to the ultimate linear segment 125a of the band 120 by a conventional VLE clip, as seen at 150 in FIG. 4. As such, the single spring attachment leg 139 obtains a wider purchase area on the band 120 end. The effect is to enhance lateral stability of the spring band assembly.
Turning now to FIG. 5, a modified coil section for a connector otherwise identical to that hereinbefore discussed is illustrated at 235. As illustrated, the coil section 235 is tightly wound in five (5) coils on an axis longitudinally aligned with the sinuous spring band span (not shown). This form of the connector 130 produces the same salutary effects, the dynamic uplift being produced by a torquing expansion-contraction of the coil section 235 in contrast to the loop compression-expansion of the coil section 35, however.
FIGS. 6 and 7 illustrate a portion of a furniture seat base 310 comprising spring band assemblies 315 (only one shown) in which a second form of spring band 320 connector is illustrated at 330. The connector 330 uses a cantilever principle to provide dynamic uplift to the band 320 at the back rail 316.
The rail connector 330 is fabricated of spring steel wire of relatively heavy gauge; i.e., eight (8) gauge or heavier. As best illustrated in FIG. 7, it includes a pair of identical connector arms 331 extending parallel to each other between the rail 316 and the band 320.
As seen once again in FIG. 6, each connector arm 331 includes a generally V-shaped body 335 made up of a rail-attachment leg 338 and a spring-attachment leg 339. The legs 338 are vertically oriented and preferably four (4) inches long. The legs 338 are joined at their upper ends by a base leg 340 which seats in a conventional EKS clip 341 stapled to the top of the rail 316.
Curving upwardly and inwardly from the lower end of each rail-attachment leg 338 is a corresponding spring-attachment leg 339. The spring-attachment legs 339 are approximately eight (8) inches long.
Formed on the free ends of the legs 339 are attachment hooks 346 identical to the hooks 146 hereinbefore discussed. The connector 330 is a variation of the second form of the invention wherein the hooks 346 receive and seat on the ultimate linear segment 325a of the spring band 320.
In operation the legs 338 are braced against the rail 316 with the spring-attachment legs 339 extending inwardly and upwardly therefrom to the hooks 346. In unloaded position the hooks are disposed approximately one (1) inch above the level of the EKS clip 341. The connector 330 thus is effective to dynamically urge the spring band 320 end upwardly when a subject is seated. At the same time longitudinal resilient expansion-contraction can and does take place in the connector 330, enhancing seat base softness.
FIG. 8 illustrates a sinuous spring band assembly 415 which incorporates a connector 430 identical to the connector 330 hereinbefore discussed.
In the spring band assembly 415 the connector hooks 446 are seated on a linear segment 425f of the band 420 which is sixth from the end of the band; i.e., the ultimate linear segment 425a. The linear segment 425a is connected to the rail by a SWING ANCHOR connector clip 460 such as illustrated in FIG. 1 of the aforementioned U.S. Pat. No. 3,790,149. The base of the clip 460 is seated, together with the base leg 440 of the connector 430, in the conventional EKS clip stapled to the top of the rail 416.
The spring band 420 immediately inwardly of its ultimate linear segment 425a, at the penultimate linear segment, is bent upwardly for the length of one semi-circular band segment 426a and then bent back into the normal arc of the band. This creates a torsion inducing moment arm configuration in the end of the band as illustrated at FIG. 12 in the aforementioned U.S. Pat. No. 3,525,514.
In operation of this spring band assembly 415 the connector 430 performs the same functions as previously ascribed to the connector 330. Further, however, its dynamic uplift is effected inwardly of the band end. This uplift, coupled with the torsion inducing band 420 configuration and the articulate connection provided by the clip 460 produces a highly sophisticated and luxurious seat base.
FIG. 9 illustrates a sinuous spring band assembly 515 which also incorporates a connector 530 identical to the connector 330 hereinbefore discussed. In the assembly 515 the sinuous band 520 is a de-arced band, however; i.e., it has very little inherent upward resilience. In this assembly the connector 530 pre-loads the band 520 upwardly at the fourth linear segment 525d from the ultimate linear segment 525a.
The ultimate linear segment 525a is seated in the EKS clip 540 on the rail 516, together with the base leg 540 of the connector 530. The connector leg 539 thus preloads the band 520 upwardly with the seat base 10 in its relaxed state as a subject is seated and rises, the connector provides a dynamic uplift which would otherwise not be present.
All of the connectors hereinbefore discussed are also used to connect other forms of seat base support means to the frame rails. As will readily be understood, wire grids such as manufactured under the trademark PERMA-MESH by Flexolators, Inc., chord-rubber webbing such as manufactured by the Pirelli, s.p.a., of Italy, and flat steel bands, for example, do not have stored upward resilience in the sense that arced sinuous spring bands do. When connected to the back frame rail by connectors embodying the inventions disclosed herein, however, they are provided with a dynamic uplift adjacent the back rail. In this sense they are similar to a de-arced sinuous spring band.
While several embodiments described herein are at present considered to be preferred, it is understood that various modifications and improvements may be made therein, and it is intended to cover in the appended claims all such modification and improvements as fall within the true spirit and scope of the invention. | A rail connector and improvement in seat base support assembly. The connector takes two basic forms. In the first a pre-stressed, close wound coil, disposed either transversely or longitudinally of the connector, is effective to continuously bias the seat base support means upwardly. In the second a cantilevered, curved spring arm serves the same purpose. The connector may be configured to reach into the body of a sinuous spring band, for example, and define a torque arm in the band, at the back rail. All forms are applicable to wire mesh, chord rubber webbing, flat steel bands and sinuous, both arced and dearced. | big_patent |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of and priority to U.S. Provisional Patent Application No. 62/352,683 filed Jun. 21, 2016, the entire disclosure of which is incorporated by reference herein.
BACKGROUND
1. Technical Description
[0002] The present disclosure is directed to an anvil assembly for use with a surgical stapling device. More particularly, the present disclosure is directed to an anvil assembly for a circular surgical stapling device including a stabilizing collet positioned to prevent damage to the anvil assembly.
2. Background of Related Art
[0003] Circular staplers are commonly used to perform a variety of surgical procedures including anastomosis procedures for joining ends of tubular tissue sections and hemorrhoidectomy procedures for treating hemorrhoids. Typically, circular staplers include a stapling device and an anvil assembly. The stapling device includes a handle assembly, a body portion extending from the handle assembly, a shell assembly including a staple cartridge, and a trocar extending from the shell assembly. The anvil assembly is releasably secured to the trocar of the stapling device and includes an anvil assembly having an anvil shaft and an anvil head assembly. The shell assembly includes a circular knife. When the circular stapler is fired, the circular knife is advanced from the shell assembly and cuts tissue as staples are ejected from the staple cartridge and formed against the anvil head assembly. In use, the stapling device and the anvil assembly are delivered to a surgical site within a patient separately and coupled to each other prior to use.
[0004] Typically, the stapling device and the anvil assembly are coupled together at the surgical site by a clinician using a grasper. More particularly, the clinician grasps the anvil shaft of the anvil assembly with the grasper and positions the anvil shaft about the trocar of the stapling device to couple the trocar to the anvil shaft. This coupling procedure takes place within a body lumen or orifice where visibility is limited.
[0005] When a clinician applies too much pressure on the anvil shaft, the anvil shaft can be damaged, e.g., crushed or deformed, such that the anvil shaft cannot be properly coupled to the stapling device. This problem is exacerbated because due to the poor visibility at the surgical site, the clinician may be unaware that the anvil shaft has been damaged and is not properly coupled to the stapling device. As such, when circular stapler is fired, the anvil assembly may become disengaged from the stapling device such that the staples are not formed in cut tissue.
[0006] Accordingly, a need exists in the surgical arts for an anvil assembly that is less susceptible to damage during attachment of the anvil assembly to the stapling device to facilitate reliable attachment of the anvil assembly to a stapling device.
SUMMARY
[0007] In one aspect of the disclosure, an anvil assembly includes an anvil shaft defining a first longitudinal bore and an anvil head assembly. The anvil shaft has a proximal portion and a distal portion. The proximal portion includes a plurality of flexible legs that define the first longitudinal bore. The anvil head assembly is secured to the distal portion of the anvil shaft and supports an anvil plate that defines a plurality of staple deforming pockets. A stabilizing collet defines a second longitudinal bore. The collet is supported within the first longitudinal bore and is positioned to prevent damage to the plurality of flexible legs.
[0008] In another aspect of the disclosure, a surgical stapler includes a stapling device and an anvil assembly. The stapling device includes a handle assembly, a body portion that extends distally from the handle assembly, a shell assembly including a staple cartridge having a plurality of staples, and a trocar extending from the shell assembly. The anvil assembly includes an anvil shaft and an anvil head assembly. The anvil shaft has a proximal portion and a distal portion and defines a first longitudinal bore configured to receive the trocar of the stapling device. The proximal portion includes a plurality of flexible legs that defines the first longitudinal bore. The anvil head assembly is secured to the distal portion of the anvil shaft and supports an anvil plate that defines a plurality of staple deforming pockets. A stabilizing collet defines a second longitudinal bore configured to receive the trocar. The collet is supported within the first longitudinal bore and is positioned to prevent damage to the plurality of flexible legs.
[0009] In embodiments, the collet is cylindrical.
[0010] In certain embodiments, the collet is substantially rigid.
[0011] In some embodiments, the collet has a distal end including a plurality of cantilevered fingers, wherein each of the plurality of cantilevered fingers has a protrusion configured to secure the collet within the first longitudinal bore of the anvil shaft.
[0012] In certain embodiments, each of the plurality of flexible legs defines a longitudinal channel with an adjacent one of the plurality of flexible legs.
[0013] In embodiments, the anvil shaft defines a hole positioned adjacent the distal end of each of the longitudinal channels. Each of the holes is configured to receive a respective one of the protrusions.
[0014] In some embodiments, each of the holes is circular.
[0015] In certain embodiments, the anvil head assembly is pivotally secured to the anvil shaft.
[0016] In embodiments, the anvil plate is annular.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Various embodiments of the presently disclosed crush resistant anvil assembly are described herein below with reference to the drawings, wherein:
[0018] FIG. 1 is a side perspective view of a surgical stapler including an exemplary embodiment of the presently disclosed crush resistant anvil assembly;
[0019] FIG. 2 is an enlarged view of the indicted area of detail shown in FIG. 1 ;
[0020] FIG. 3 is a cross-sectional view taken along section line 3 - 3 of FIG. 2 ;
[0021] FIG. 4 is a side perspective view of the anvil assembly shown in FIG. 2 ;
[0022] FIG. 5 is an enlarged view of the indicated area of detail shown in FIG. 4 ;
[0023] FIG. 6 is a side perspective view of a collet of the anvil assembly shown in FIG. 4 ;
[0024] FIG. 7 is a side cross-sectional view of the collet shown in FIG. 6 and the anvil shaft of the anvil assembly shown in FIG. 4 with parts separated;
[0025] FIG. 8 is a side cross-sectional view of the collet and anvil shaft shown in FIG. 7 as the collet is slid into the anvil shaft;
[0026] FIG. 9 is a side cross-sectional view of the collet and anvil shaft shown in FIG. 8 with the collet secured within the anvil shaft; and
[0027] FIG. 10 is a side cross-sectional view of the collet and anvil shaft shown in FIG. 9 as a trocar of the stapling device is positioned within the anvil shaft.
DETAILED DESCRIPTION OF EMBODIMENTS
[0028] Exemplary embodiments of the presently disclosed damage resistant anvil assembly will now be described in detail with reference to the drawings in which like reference numerals designate identical or corresponding elements in each of the several views. In this description, the term “proximal” is used generally to refer to that portion of the stapler that is closer to a clinician, while the term “distal” is used generally to refer to that portion of the stapler that is farther from the clinician. In addition, the term “endoscopic” is used generally to refer to procedures performed through a small incision or a cannula inserted into a patient's body including endoscopic, laparoscopic, and arthroscopic procedures. Finally, the term clinician is used generally to refer to medical personnel including doctors, nurses, and support personnel.
[0029] The presently disclosed anvil assembly includes an anvil head assembly, an anvil shaft, and a stabilizing collet. In embodiments, the stabilizing collet may be formed of a substantially rigid material. Alternately, other materials of construction that provide support to the anvil shaft are envisioned. The anvil shaft includes a plurality of flexible legs that flex outwardly in response to insertion of a trocar of a surgical stapling device into the anvil shaft to releasably couple the anvil shaft to the trocar. The collet is received within a longitudinal bore defined by the flexible legs of the anvil shaft at a location to support the flexible legs and minimize the likelihood of damage to the anvil shaft caused by engagement of the anvil shaft with a grasper. The collet is also positioned in a location not to interfere with flexing of the legs during coupling of the anvil shaft to the trocar of the stapling device.
[0030] FIG. 1 illustrates a manually powered surgical stapler 10 including a stapling device 12 supporting an exemplary embodiment of anvil assembly 100 . The stapling device 12 includes a handle assembly 14 , a body portion 16 that extends distally from the handle portion 14 , and a shell assembly 18 that supports a staple cartridge 20 . The staple cartridge 20 supports a plurality of staples (not shown) that are arranged in an annular configuration within the shell assembly 18 . The stapling device 12 also includes a trocar 22 that extends from the distal end of the body portion 16 through the shell assembly 18 . The trocar 22 is configured to releasably engage the anvil assembly 100 as described in further detail below. For a more detailed description of a suitable stapling device, see U.S. Pat. Nos. 7,234,624, 7,364,060 and 7,857,187 (“the incorporated patents”) which are incorporated herein by reference in their entirety.
[0031] Referring also to FIGS. 2-4 , the anvil assembly 100 includes an anvil head assembly 102 and an anvil shaft 104 . Although not specifically described in this application, the anvil head assembly 102 can be pivotally or fixedly attached to the anvil shaft 104 . Examples of pivotally attached anvil head assemblies are described in the incorporated patents.
[0032] The anvil head assembly 102 includes a housing 106 that supports an anvil plate 108 ( FIG. 2 ) and a cut ring assembly 110 . The housing 106 has a smoothly curved distal surface 112 that facilitates atraumatic entry of the anvil assembly 100 into and through a body orifice or lumen. A proximal side of the housing 106 defines a cavity (not shown) that is configured to receive the anvil plate 108 and the cut ring assembly 110 . For a more detailed description of the components of the anvil head assembly 102 , see the incorporated patents.
[0033] The anvil shaft 104 includes a longitudinal body portion 116 that includes a tubular portion 118 and a plurality of flexible legs 120 that extend proximally from the tubular portion 118 . Each of the flexible legs 120 has a semi-cylindrical configuration such that the legs 120 cooperate to define a longitudinal bore 122 ( FIG. 3 ) that is dimensioned to receive the trocar 22 of the stapling device 12 ( FIG. 1 ) when the anvil assembly 100 is secured to the stapling device 12 . The bore 122 extends from the proximal end of the flexible legs 120 at least partially into the tubular portion 118 of the anvil shaft 104 .
[0034] In embodiments, the anvil shaft 104 may include a plurality of splines 126 positioned about the anvil shaft 104 . As is known in the art, the splines 126 mate with recesses (not shown) defined within the shell assembly 16 FIG. 2 ) of the surgical stapling device 12 to properly orient the staple cartridge 20 in relation to the anvil plate 108 of the anvil assembly 100 when the anvil assembly 100 and the shell assembly 18 are approximated. The anvil shaft 104 may also include one or more stabilization rings 130 (only one is shown) positioned about the anvil shaft 104 at a position to engage the shell assembly 16 when the anvil assembly 100 and the shell assembly 18 are approximated to provide added stability to the anvil assembly 100 . For a more detailed description of an anvil assembly including a stabilization ring, see U.S. Pat. No. 8,424,535 which is incorporated herein by reference in its entirety. Although the splines 126 and the stabilization ring 130 are shown to be formed integrally with the anvil shaft 104 , it is contemplated the either or both could be formed separately from the anvil shaft 104 and secured to the anvil shaft 104 using any known fastening technique including welding, crimping gluing or the like.
[0035] Referring to FIGS. 4 and 5 , each of the flexible legs 120 of the anvil shaft 104 defines a longitudinal channel 134 with an adjacent leg 120 . Each longitudinal channel 134 includes an enlarged cutout or hole 136 formed at the distal end of the longitudinal channel 134 . The holes 136 are configured to secure a collet 150 within the longitudinal bore 122 of the anvil shaft 104 . In embodiments, the hole 136 is substantially circular although other configurations are envisioned. One or more of the flexible legs 120 may also include a bore 140 which is configured to receive a suture or the like (not shown). The suture can be used to allow a clinician to retrieve or position the anvil assembly 100 from or within a surgical site. The proximal end of each of the flexible legs 120 has an inner surface that defines a recess 160 ( FIG. 7 ) such that the recesses 160 collectively define an annular recess 160 a ( FIG. 9 ). The annular recess 160 a facilitates releasable engagement of the anvil assembly 100 to the stapling device 12 .
[0036] Referring also to FIG. 6 , the collet 150 may be substantially rigid and is positioned within the longitudinal bore 122 defined by the anvil shaft 104 . The collet 150 is substantially cylindrical and defines a longitudinal bore 152 ( FIG. 7 ) that is dimensioned to receive the trocar 22 ( FIG. 10 ). A distal portion 154 of the collet 150 includes a plurality of cantilevered fingers 156 . Each of the fingers 156 includes a protrusion 158 that is dimensioned and configured to be received in a respective one of the holes 136 ( FIG. 5 ) formed in the anvil shaft 104 as described in further detail below.
[0037] Referring to FIGS. 7-9 , in order to assemble the collet 150 within the anvil shaft 104 , the distal end of the collet 150 is inserted into the proximal end of the longitudinal bore 122 of the anvil shaft 104 and slid distally in the direction indicated by arrow “A” in FIGS. 7 and 8 . The collet 150 is positioned to align the protrusions 158 with the longitudinal channels 134 positioned between the flexible legs 120 . When the protrusions 158 engage an inner wall of the flexible legs 120 , the fingers 156 are deflected inwardly in the direction indicated by arrow “B” in FIG. 8 to facilitate passage of the collet 150 through the longitudinal bore 122 . When the protrusions 158 are moved into alignment with the holes 136 , the fingers 156 spring outwardly in the direction indicated by arrow “C” in FIG. 9 to move the protrusions 158 into the holes 136 to secure the collet 150 within the longitudinal bore 122 .
[0038] Referring to FIG. 10 , the trocar 22 includes a pointed distal end 30 and an enlarged proximal portion 32 that defines a shoulder 32 a . As known in the art, the proximal end of the trocar 22 is secured to an approximation mechanism (not shown) of the stapling device 12 ( FIG. 1 ) to facilitate movement of the trocar 22 between retracted and advanced positions. When the trocar 22 is inserted into the longitudinal bore 122 of the anvil shaft 104 and the longitudinal bore 152 of the collet 150 in the direction indicated by arrow “D” in FIG. 10 , the enlarged proximal portion 32 of the trocar 22 engages a proximal end of the flexible legs 120 of the anvil shaft 104 to urge the flexible legs 120 outwardly in the direction indicated by arrows “E”. When the enlarged proximal portion 32 of the trocar 22 is moved distally in the direction indicated by arrow “D” into alignment with the recess 160 defined at the proximal end of the flexible legs 120 , the flexible legs 120 return to their undeformed configuration to receive the enlarged proximal portion 32 of the trocar 22 . When the enlarged proximal portion 32 is received within the recess 160 , the shoulder 32 a on the enlarged proximal portion 32 of the trocar 32 engages a proximal wall 161 defining the recess 160 to secure the anvil shaft 104 to the trocar 22 .
[0039] During an endoscopic surgical procedure, the anvil assembly 100 is grasped with a grasper (not shown) that is inserted through a small incision in the skin to position the trocar 22 within the longitudinal bore 122 of the anvil shaft 104 and secure the anvil assembly 100 to the trocar 22 of the surgical stapling device 12 . The collet 150 is positioned within the longitudinal bore 122 of the anvil shaft 104 and extends from a distal end of the flexible legs 120 towards the proximal end of the flexible legs 120 to support the flexible legs 120 and inhibit radial compression or other deformation of the flexible legs 120 that may result from pressure applied to the flexible legs 120 by a manipulating instrument (not shown). Collet 150 may be formed from any suitable, medical grade material having a stiffness to perform the functions described herein. Suitable materials include, for example, stainless steel or nylon. The collet 150 is secured within the longitudinal bore 122 of the anvil shaft 104 in a position that does not interfere with outward flexing of the flexible legs 120 and, thus, allows the anvil assembly 100 to be readily connected to the trocar 22 .
[0040] Persons skilled in the art will understand that the devices and methods specifically described herein and illustrated in the accompanying drawings are non-limiting exemplary embodiments. It is envisioned that the elements and features illustrated or described in connection with one exemplary embodiment may be combined with the elements and features of another without departing from the scope of the present disclosure. As well, one skilled in the art will appreciate further features and advantages of the disclosure based on the above-described embodiments. Accordingly, the disclosure is not to be limited by what has been particularly shown and described, except as indicated by the appended claims. | An anvil assembly is disclosed that includes an anvil shaft including a proximal portion and a distal portion and defining a first longitudinal bore. The proximal portion includes a plurality of flexible legs that define the first longitudinal bore dimensioned to receive a trocar of a stapling device. An anvil head assembly is secured to the distal portion of the anvil shaft and supports an annular anvil plate that a plurality of staple deforming pockets. The anvil assembly also includes a rigid collet defining a second longitudinal bore that is configured to receive the trocar of the stapling device. The rigid collet is supported within the first longitudinal bore and is positioned to prevent crushing of the plurality of flexible legs when the anvil assembly is manipulated with a grasper. | big_patent |
FIELD OF THE INVENTION
[0001] The present invention relates to the container of the blender, particularly to a set of high-speed blades mounted inside the lower portion of the container.
GROUND OF THE INVENTION
[0002] The usage of blender become popular today; the configuration structure of a blender is mainly a set of rotatable blades disposed inside the container to mix the ice cubes, vegetables and fruits until they become liquid.
[0003] In early phases, the container of the blender was made of glass. The user began to operate with a glass container, somehow a glass break detector, if any, was needed by manufacturers to know whether the glass container was broken a little or not, in view of the fractures or cracks happened to occur on the glassware due to impacts or collisions. Density-dependent factors such as to expand when hot to shrink when cold also caused the glass surfaces to expand or shrink disproportionately and then cracks began to occur. Persons skilled in the art provided reinforced plastic such as acrylic resin to manufacture the container of the blender instead of the glassware. Because the reinforced plastic was not only light weight but also cost efficient, durable and rigid, they were attractive raw materials cherished by the manufacturers and consumers. But the containers made of reinforced plastic, during longer time period usage, the inner wall was impacted or collided intermittently by the stirred objects, eventually it resulted in nicks. Debris of the scraped acrylic resin was possibly mixed into the liquid. Once the debris remained in the liquid got drunk by consumers led to a poor hygiene condition. In fact the manufacturers provided a container made simply from a reinforced plastic hardly complied with all hygienic rules. The inventors of the present invention encounter the problems as mentioned above, provide a metal lining (cylindrical member) to shield the inner wall of the receptacle, which is known by their patent document 1.
[0004] Patent Document 1: TW580,899 entitled “container for blender” assigned to the inventors Kou-I Ling and Rong-Yuan Tseng of the present invention on 21 Mar. 2004, the same is also patented in the USA assigned patent number as U.S. Pat. No. 6,786,440 on 7 Sep. 2004.
DISCUSSION ABOUT PRIOR ARTS
[0005] As shown in FIG. 1 , a conventional blender having a cup ( 1 ), a set of blades ( 3 ) installed within the base of cup ( 1 ). When blades ( 3 ) are rotated in high speed, the vegetable and fruit will be grated until they become liquid as well as a whirlpool is formed in the receptacle, which is illustrated and indicated by spiral arrows as shown in FIG. 2 . But the whirlpool ( 4 ) in usual brings the rough and long fibers ( 41 ) to the outer circle in contact with the inner wall by centrifugal force. In other words, by centrifugation the rough and long fibers ( 41 ) is not swirl into the center of the whirlpool ( 4 ) but whirl around the outer circle thereof. Some rough and long fibers ( 41 ) are neither brought to the lower portion of the cup ( 1 ) by whirlpool ( 4 ) nor further being grated by the blades ( 3 ). It could not catch one's sense when drinking juice with rough and long fibers are not liquefied efficiently. A spoon may be inserted into the whirlpool ( 4 ) or the stirring time is prolonged to grate the rough and long fibers. As a result, for a longer time period, the grated fibers immersed in the liquid are stirred to a foam with bubbles, this “oxidization” activity exposed in the air is going to influence the bright color and luster of the juice. The nutrition will be lost; the active fiber basis vitamins will be destroyed. The same problems happened to occur in the cited patent document 1. Accordingly, a metal lining combined to the inner wall of the cup ( 1 ) as a shield reduces the stirring time for promptly providing juice catches the user's sense. That is the key point of the present invention.
SUMMARY OF THE INVENTION
[0006] Accordingly, the present invention is aimed to provide a container of the blender comprises a cup ( 1 ) and a lining ( 2 ) disposed inside the cup ( 1 ) characterized in that the lining ( 2 ) is formed as a shield inside the cup ( 1 ), a number of teeth ( 21 ) projected from the inner wall of the lining ( 2 ) for grinding the fibers of vegetable and fruit.
[0007] The lining ( 2 ) is selected from one of the following: metal lining, glass lining, lining has approximately the same hardness.
[0008] Several vertical ribs ( 11 ) projected from the inner wall of the cup ( 1 ), several vertical stopper members ( 22 ) formed on the inner wall of the lining ( 2 ) which are corresponding to the vertical ribs ( 11 ), the ribs ( 11 ) are received into the hollowed trough of the stopper members ( 22 ).
[0009] A number of teeth ( 21 ′) are arranged on and projected up from the top end of the stopper members.
[0010] The rib ( 11 ) has a vertical facet ( 111 ), and the stopper member 22 has a vertical facet ( 221 ).
[0011] The lining ( 2 ) is selected from one of the following: half-mask, whole mask.
[0012] The half-mask lining is combined to the cup ( 1 ) by injection modeling.
[0013] The half-mask lining is mounted inside the cup ( 1 ), the top rim of the lining ( 2 ) has lip ( 26 ).
[0014] The half-mask lining is mounted inside the cup ( 1 ), several prop stands ( 24 ) extended from the top rim of the lining ( 2 ), a horizontal ring is connected to the top portion of the prop stands ( 24 ).
[0015] The half-mask lining is mounted inside the cup ( 1 ), the top rim of the lining ( 2 ) has horizontal ring extended radially outwardly.
[0016] The lining ( 2 ) is selected from one of the following: integrally formed as a whole annular lining, a number of lining pieces ( 2 a ), or ( 2 b ) combined to form an annular lining.
[0017] The first facet of the stopper member ( 22 ) is bended inward to form a buckled piece ( 222 ), the buckled piece ( 222 ) leads into a groove ( 113 ) defined on the first facet of the rib ( 11 ), the second facet of the lining pieces ( 22 ) is a flat facet directly leads into a trench ( 112 ) defined on the second facet of the rib ( 11 ) of the cup ( 1 ).
EFFECTS AND MECHANISMS OF THE PRESENT INVENTION
[0018] The advantages can be achieved from practicing of the present invention as following:
[0019] The rigid lining ( 2 ) shields the inner wall of the receptacle from collision of rigid material, but the fibers remained in the teeth ( 21 ) on the inner wall of the lining can be ground and cut into pieces. Therefore, the duration of grating fruit and vegetable can be reduced, the related “oxidization” activity of the juice exposed in air will also be decreased; rather, the bright color and luster of the juice can be kept vividly. The nutrition will not be lost, further the active fiber basis vitamins and sense of smell is kept as a freshener.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 : a cross sectional view of the prior art, a conventional container of the blender;
[0021] FIG. 2 : a top plan view of FIG. 1 ;
[0022] FIG. 3 : an exploded view of the receptacle of the juicer according to the first embodiment of the present invention;
[0023] FIG. 4 : an assembled view of the container of FIG. 3 ;
[0024] FIG. 5 : a cross sectional view of FIG. 3 ;
[0025] FIG. 6 : a top plan view of FIG. 3 ;
[0026] FIG. 7 : a schematic view of FIG. 3 ;
[0027] FIG. 8 : an exploded view of the container of the blender according to the second embodiment of the present invention;
[0028] FIG. 9 : an assembled view of FIG. 8 ;
[0029] FIG. 10 : an exploded view of the container of the third embodiment of the present invention;
[0030] FIG. 11 : an assembled view of FIG. 10 ;
[0031] FIG. 12 : an exploded view of the container of the fourth embodiment of the present invention; and
[0032] FIG. 13 : an assembled view of FIG. 12 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
First Embodiment
[0033] As shown in FIG. 3 , the present invention is a container includes a cup ( 1 ), a rigid lining ( 2 ) mounted inside the cup ( 1 ). The lining ( 2 ) is a prefabricated component combined to the cup ( 1 ) by injection molding. In other words, the lining ( 2 ) is first placed in the mode and then a transparent or translucent acrylic cup ( 1 ) is formed to wrap over the circumference of the lining ( 2 ) integrally as a whole by injection molding; finally, they are never detached from each other.
[0034] Lining ( 2 ) is shaped as a half-mask, that is, the lining ( 2 ) only shields the lower half portion of the cup ( 1 ) but the upper half portion of the cup ( 1 ) is not shielded by the lining ( 2 ). Users can see vegetable or fruit cubes are whipped or thrashed in the cup ( 1 ). If the lining ( 2 ) is shaped as a whole-mask (as shown in FIG. 13 ), the upper and lower half portions of the cup are shielded by the lining ( 2 ). Users only look down on the vegetable or fruit cubes whipped or thrashed in the cup ( 1 ).
[0035] Lining ( 2 ) is combined to the inner wall of the cup ( 1 ) to form a shield screen characterized in that a number of teeth ( 21 ) projected from the inner wall of the lining ( 2 ) applied to grate fibers of vegetable and fruit. Teeth ( 21 ) can be arranged in parallel with one another, but they are all arrayed in alignment with each other finally to form a crossed or columned shape of teeth array. Rather, the lining ( 2 ) can be made of metal, glass, alloy, or non-alloy material, which is with a hardness rather rigid than the acrylic cup ( 1 ). Lining ( 2 ) is an annular member formed integrally as a whole one, but which is preferred in the shape of polygon. A lining base ( 21 ) can be added to the bottom of the cap ( 1 ) as a shield screen thereof. The top end of the lining ( 2 ) has an L type wall ( 25 a ) bended outward and upward, the bottom end of the lining ( 2 ) has an L type wall ( 25 b ) bended inward and downward respectively. Both L type walls ( 25 a , 25 b ) are embedded into the inner wall of the cup ( 1 ) to eliminate the permeation of liquid through a chink on the wall.
[0036] Cup ( 1 ) has a handle ( 12 ) and a spout ( 13 ). Several vertical ribs ( 11 ) are protruded from the inner wall of the cup ( 1 ); several vertical stopper members ( 22 ) corresponding to the ribs ( 11 ) are also formed on the obverse side of the wall of the lining ( 2 ), hollowed troughs opposed to the stopper members ( 22 ) are formed on the reverse side of the wall of the lining ( 2 ), the hollowed troughs are suitable for matching up and receiving the vertical rib ( 11 ).
[0037] As shown in FIG. 6 , look down on the cup ( 1 ), and the lining ( 2 ), a facet ( 111 ) of the rib ( 11 ) and a facet ( 221 ) of the stopper members ( 22 ) can be formed as perpendicular spoilers which dampen vibration of the vegetable and fruit fibers (as shown in FIG. 7 ) but sweep them in the whirlpool ( 4 ) as much as possible to the center thereof; and then to the lower half portion of the cup ( 1 ) being crumbled by the straight blades. But only a few rough and long fibers ( 41 ) are forced into the center of the whirlpool, most of them still left outside the inner circle of the whirlpool ( 4 ).
[0038] As shown in FIG. 7 , when the straight blades (not shown) is rotated in high speed, rough and long fibers ( 41 ) in the whirlpool ( 4 ) remained in the teeth ( 21 ) on the surrounding inner wall of the lining ( 2 ) will soon be grated and chopped into pieces. Possibility of the rough and long fibers being grated is greatly improved. Though the fibers all are not easily forced into the whirlpool center at once, they can be chopped into pieces by the teeth ( 21 ) as well. Therefore, the duration for the blender stirring the chopped fibers is reduced; meanwhile, possibility of oxidization of the stirred juice is also reduced. Rather, the top end of the stopper members ( 22 ) has a number of teeth ( 21 ′) projected up thereof, by means of the projected teeth ( 21 ′), the fibers of vegetable and fruit can be further grated and chopped into pieces. The teeth ( 21 ′) projected up from the top end of the stopper members ( 22 ) are advantageous to the grinding.
Second Embodiment
[0039] As shown in FIG. 8 , the container of the blender includes a cup ( 1 ), and a rigid lining ( 2 ) mounted inside the cup ( 1 ). First, each of the cup ( 1 ) and lining ( 2 ) are prefabricated components, and then the lining ( 2 ) is mounted inside the cup ( 1 ) and combined to the cup ( 1 ) integrally as a whole. After combination, the assembled view of the container is illustrated as shown in FIG. 9 .
[0040] The lining ( 2 ) is shaped as a half-mask. But several prop stands ( 23 ) extended from the top rim of the hood ( 2 ) to a height adjacent to the top rim of the cup ( 1 ), a horizontal ring ( 24 ) is connected to the top ends of the prop stands ( 23 ). The horizontal ring ( 24 ) is convenient for the users to hold, and when the lining ( 2 ) is mounted inside the cup ( 1 ), the horizontal ring ( 24 ) placed on the L-shape (i.e. like a top step of a ladder) top rim of the container which is suitable for a lid (not shown) capped over the container, then the horizontal ring ( 24 ) is sandwiched between the container and the lid. Therefore the lining ( 2 ) can be mounted inside the container without any movements.
Third Embodiment
[0041] As shown in FIG. 10 , the container of the blender includes a cup ( 1 ), and a rigid lining ( 2 ) mounted inside the cup ( 1 ). The cup ( 1 ) and the lining ( 2 ) are prefabricated separately, and then the lining ( 2 ) is embedded into the cup ( 1 ) and combined to the cup ( 1 ) integrally as a whole. After combination, the assembled view is illustrated as shown in FIG. 11 .
[0042] The lining ( 2 ) is shaped as a half mask, which is composed of a number of lining pieces ( 2 a ). A stopper member ( 22 ) is formed on the obverse side of the lining piece ( 2 a ) as well as the teeth ( 21 ) are arrayed on the same side. The first facet of the stopper member ( 22 ) is bended inward to form a buckled piece ( 222 ). A groove ( 113 ) is defined on the first facet of the rib ( 11 ) of the cup ( 1 ), the buckled piece ( 222 ) can be led into the groove ( 113 ) in place and then the rib ( 11 ) enclosed inside the hollowed trough formed on the reverse side of the stopper member ( 22 ). The second facet of the lining pieces ( 22 ) is a flat facet directly leads into a trench ( 112 ) defined on the second facet of the rib ( 11 ) of the cup ( 1 ). A number of teeth ( 21 ′) can also be arranged on the top end of stopper member ( 22 ). Rather, the lip ( 26 ) is extended radially outwardly from the top rim of the lining pieces ( 2 a ) is convenient for the user to hold when the lining pieces ( 2 a ) are assembled or disassembled with each other.
Fourth Embodiment
[0043] As shown in FIG. 12 , the container of the blender includes a cup ( 1 ), and a rigid lining ( 2 ) mounted inside the cup ( 1 ). The cup ( 1 ) and the lining ( 2 ) are prefabricated components. The lining ( 2 ) is embedded into the cup ( 1 ) and then combined to the cup ( 1 ) integrally as a whole. After combination, the assembled view is illustrated as shown in FIG. 13 .
[0044] The lining ( 2 ) is shaped as a whole mask. The lining ( 2 ) is composed of a number of lining pieces ( 2 b ), but the top rim of the lining ( 2 ) is bended outward to form a horizontal ring ( 27 ). The horizontal ring ( 27 ) is not only convenient for the user to hold to assemble or disassemble the lining pieces ( 2 b ), but the horizontal ring ( 27 ) can be placed on the top step of the ladder like top rim of the container so as the horizontal ring ( 27 ) can be sandwiched between the cup ( 1 ) and the lid (not shown) without any movements. | The present invention is aimed to provide a container of the blender. It can prevent the inner wall of the container from abrasions and blemishes. Further, the time-consuming for fibers of the fruit and vegetable being grated and chopped can be reduced. The container of the blender includes a cup, a lining mounted inside the cup characterized in that the lining as a shield screen on the inner wall of the cup, the inner wall of the lining has a number of teeth projected thereof for grating the fibers of the vegetable and fruit. | big_patent |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application claims priority to and is a continuation of U.S. patent application Ser. No. 13/080,754, titled GARNISH PICK, filed Apr. 6, 2011, which is a Non-Provisional of and claims priority to U.S. Provisional Patent Application Ser. No. 61/321,291, titled GARNISH PICK, filed Apr. 6, 2010, the entire contents of these applications are incorporated herein by reference in their entirety for all purposes.
BACKGROUND
[0002] A variety of garnishes may be used to add flavor and decoration to foods and beverages. For example, beverages including alcoholic cocktails may be served with a garnish of vegetables or fruits that are at least partially submerged in the beverage. Such garnishes are often served on a garnish pick in order to secure the garnish and enable the garnish to be more easily removed from the beverage.
SUMMARY
[0003] A garnish pick is disclosed that includes one or more appendages. In at least some embodiments, at least some of the appendages may comprise skewering shafts that are tapered and/or sharpened at an outer tip of the appendage for skewering and holding a garnish. Such appendages may project from a main shaft of the garnish pick at a variety of angles and/or orientations. In at least some embodiments, the angles and/or orientations at which such appendages project from a main shaft may be defined so that the garnish pick simulates the appearance of an organism or a portion thereof, such as a branch of a tree or an antler of an animal. In at least some embodiments, at least some of the appendages may form a hook for securing the garnish pick to a food or beverage container, such as a rim of a serving glass. An appendage that forms a hook may be used to prevent the garnish pick from becoming further submerged or entirely submerged into foods or beverages in a container. Accordingly, an appendage of the garnish pick may serve either as a shaft with which to skewer and hold a garnish, or as a hook for accepting a rim of a food or beverage container. At least some embodiments, the garnish pick may have two or more appendages, wherein at least one of the appendages may serve as a hook, while at least one of the other appendages may serve as a skewering shaft.
BRIEF DESCRIPTION OF DRAWINGS
[0004] Non-limiting and non-exhaustive aspects are described with reference to the following figures, wherein like reference numerals refer to like parts throughout the various figures unless otherwise specified.
[0005] FIG. 1 shows an example garnish pick, according to one embodiment, in a martini glass, in which the pick has a straight main shaft and a single appendage serving as a hook for the rim of the glass.
[0006] FIG. 2 shows an example garnish pick, according to one embodiment, situated in a martini glass, in which the pick has a curving main shaft and two appendages. One appendage serves as a hook, and the other as a skewering shaft.
[0007] FIG. 3 shows an example garnish pick, according to one embodiment, in which the main shaft is forked, forming two skewering shafts. In this figure a single pick shown in three different views that are rotated 45 degrees relative to each other shows the relative position of the hook.
[0008] FIG. 4 shows an example garnish pick, according to one embodiment, in which three appendages connect to a curved shaft resembling, for example, a deer's antler. One appendage serves as a hook and the other two as skewering shafts.
[0009] FIG. 5 shows an example garnish pick, according to one embodiment, in which two appendages connect to a curved shaft, one of which serves as a hook and the other as a skewering shaft.
[0010] FIG. 6 shows an example garnish pick, according to one embodiment, in which the pick is rotated approximately 90 degrees relative to each other in each figure, and in which three appendages connect to a curved main shaft, one of which serves as a hook and the others as skewering shafts.
[0011] FIG. 7 shows an example garnish pick, according to one embodiment, in which there is no hooking appendage and in which main shaft forks, forming two skewering appendages.
[0012] FIG. 8 shows another example garnish pick according to one embodiment.
[0013] FIG. 9 shows an example garnish pick, according to one embodiment, in which two appendages emerge from opposite or opposing sides of a straight shaft, forming three skewing shafts.
[0014] FIG. 10 shows an example garnish pick, according to one embodiment, in which three appendages and the main shaft are contoured to resemble, for example, a twig or branch of a tree or plant.
[0015] FIG. 11 shows three example garnish picks, according to three embodiments, which are contoured to resemble twigs or branches.
[0016] FIG. 12 shows another example garnish pick according to one embodiment.
[0017] FIG. 13 shows the example garnish pick of FIG. 12 in an example use environment of a beverage container.
DETAILED DESCRIPTION
[0018] Conventional cocktail garnish picks are typically thin, straight, cylindrical pieces of wood, metal or plastic, with a sharpened end. While the typical garnish pick is formed by a single straight shaft to skewer and hold a garnish, such a design allows the entire pick to occasionally slide below the line of the liquid, potentially submerging the garnish pick. This is inconvenient for people that prefer to eat the garnish while drinking the cocktail, because it may require the person to dip his or her fingers into the cocktail to retrieve the pick and garnish, and which may be perceived as unsanitary and unappealing. In addition, when more than one garnish is skewered and stacked onto a single shaft, it may be difficult for a person to remove each garnish from the garnish pick without using his or her fingers. If, for example, three olives are stacked on a single shaft, the olive next to the sharp end of the shaft can be easily pulled off by a person using their teeth, while removing a second or third olive may require the person to use his or her fingers to remove the second or third olives because of the increased distance of the second and third olives from the sharp end of shaft.
[0019] Referring now to FIG. 1 , an example garnish pick 100 is shown according to one embodiment in an example usage environment of a martini glass 114 . Specifically, FIG. 1 shows how an appendage 110 of the garnish pick may exit a main shaft 112 angling toward the skewering end of the garnish pick, and hook or otherwise secure the pick to the rim of a glass, preventing the garnish pick from sliding into the cocktail glass, or completely or further submerging the garnish pick into a beverage. In this embodiment, the main shaft 112 also serves as a skewering shaft for holding a garnish.
[0020] FIG. 2 shows a garnish pick 200 in an example usage environment of a martini glass 216 . In this example embodiment, garnish pick 200 includes three appendages, wherein a first appendage 210 may serve as a hook, and a second appendage 212 and a third appendage 214 may serve as skewering shafts. FIG. 2 also shows how garnishes, e.g., in this case olives, can be held on the garnish pick, for example, by appendages 212 and 214 .
[0021] FIG. 3 shows a single embodiment of a garnish pick depicted at different angles rotated 45 degrees relative to each other. FIG. 3 shows how multiple appendages can exit the primary shaft, one serving as a hook for the rim of the glass, while the others serve as skewers.
[0022] In further detail, still referring to FIG. 1 , FIG. 2 and FIG. 3 , the garnish pick may be of a total length that is approximately equal to the distance from the rim of a martini glass to the center of the bottom of the glass. However, other suitable lengths may be used. Because martini glasses come in a variety of shapes and sizes, this distance may vary. In at least one non-limiting example, a total length of the garish pick does not exceed five inches and is not less than two inches in length. FIG. 9 further shows how an appendage for serving as a hook may be omitted from the garnish pick in at least some embodiments.
[0023] In at least some embodiments, a total diameter or width of the garnish pick may be at its largest is 15 cm or less, with the diameter or width diminishing toward the sharp end of the skewering shafts. The portions of the garnish pick that are adapted to hold a garnish may have a diameter sufficiently small such that a garnish (e.g., an olive or other suitable garnish item) can slide onto that portion of the garnish pick without undue difficulty and/or without splitting or damaging the garnish.
[0024] In at least some embodiments, the main shaft and/or appendages may curve, have abrupt bends, or be curved along at least a portion of its axis. The main shaft and/or appendages may have bumps, ridges, craters, or be otherwise unsmooth or rough (e.g., as shown by the non-limiting examples of FIGS. 10 and 11 ). The main shaft and/or appendages may have circular cross-sections, convolute cross-sections, ovular cross-sections, non-circular cross-sections, square or rectangular cross-sections, pentagonal cross-sections, hexagonal cross-sections, or irregularly shaped cross-sections, among other shapes. The main shaft and/or appendages may have twists and/or cork screws that may be expanding or narrowing (e.g., at a radius of curvature) along a longitudinal axis of the main shaft or appendage (e.g., non-regular corkscrew or twist). Such twists and/or corkscrews may be less than a full rotation, between one full rotation and two full rotations, greater than two full rotations, or comprise an even greater number of rotations. In at least some embodiments, one or more of the appendage may have smaller appendages (e.g., sub-appendages) that branch from them.
[0025] The construction details of the garnish picks disclosed herein may be that such garnish picks may be made of wood or of any other sufficiently rigid, flexible, and/or strong material such as plastic, rubber, metal, glass, ceramic, and the like depending on implementation. Further, the various components of the garnish pick can be made of different materials. For example, a garnish pick may comprise two or more materials. For example, the garnish pick may comprise a first material (e.g., metal or plastic) having an outer coating comprising a second material (e.g., rubber, plastic or paint).
[0026] The advantages of the disclosed embodiments may include, without limitation, that the garnish pick can be hooked to the side of a glass, preventing the pick from becoming completely or further submerged in a beverage, and can provide additional shafts (e.g., appendages) on which to hold garnishes. Such embodiments may also eliminate the need to retrieve the pick out of the beverage or beverage container (e.g., with fingers) and may make it easier to eat garnishes off of the pick (e.g., without using fingers to touch the garnishes).
[0027] As previously described, a garnish pick is provided that may be used to hold garnishes with one or more appendages emerging from a main shaft, angled toward a sharp end of the main shaft, that are used either to hook the pick to the rim of the glass or to skewer garnishes, or both. In embodiments where the garnish pick comprises a plurality of appendages, such appendages may project from a main shaft of the garnish pick at the same or different angles relative to each other along a longitudinal axis and/or an orthogonal axis of the main shaft. For example, a first appendage may project from the main shaft at a greater angle relative to a longitudinal axis of the main shaft than a second appendage and/or a third appendage. Accordingly, the garnish pick may comprise two, three, four, five, or more appendages that each project from a main shaft or other base appendage (e.g., where such appendages comprise sub-appendages) at different angles relative to each other as measured relative to a longitudinal axis of the main shaft or other base appendage. As another example, a first appendage may project from the main shaft or other base appendage (e.g., for sub-appendages) at a 2 o'clock position when viewed in a plane that is orthogonal to the longitudinal axis of the main shaft or base appendage, while a second appendage may project from the main shaft at a 6 o'clock position, and/or a third appendage may project from the main shaft at an 8 o'clock position. Such examples are provided for descriptive purposes and should not be considered limiting.
[0028] FIG. 12 shows another example garnish pick 1200 according to one embodiment. FIG. 13 shows the example garnish pick 1200 of FIG. 12 in an example use environment of a beverage container. Garnish pick 1200 includes a pick body 1210 . The pick body may include a first elongate body portion 1212 having a first end 1214 forming a first tapered skewer 1216 and having a second end 1218 forming a hook 1220 . The pick body may include a second elongate body portion 1230 branching outward from the first elongate body portion at an intermediate location 1232 between first end 1214 and second end 1218 . The second elongate body portion may have a distal end 1232 forming a second tapered skewer 1234 . In at least some embodiments, first elongate body portion 1212 may taper from second end 1218 toward first end 1214 , and second elongate body portion 1230 may taper from a base end 1236 toward distal end 1232 of the second elongate body portion.
[0029] In at least some embodiments, a cross-sectional area of the second elongate body portion at the base end is smaller than a cross-sectional area of the first elongate body portion at the intermediate location where the second elongate body portion branches outward from the first elongate body portion. In at least some embodiments, the first elongate body portion may be curved along a length of the first elongate body portion between the first end and the second end. The curvature of the first elongate body portion may vary along at least a portion of the length of the first elongate body portion between the first end and the second end. In at least some embodiments, the first elongate body portion may be curved in one, two, or more orthogonal planes along at least a portion of the length of the first elongate body portion between the first end and the second end. The second elongate body portion may be curved in one, two, or more orthogonal planes along at least a portion of a length of the second elongate body portion between a base end and the distal end. The first and second elongate body portions may each have a different curvature. A length of the second elongate body portion may be less than, greater than, or equal to a length of the first elongate body portion between the intermediate location and the first end of the first elongate body portion.
[0030] In at least some embodiments, the pick body may further include a third elongate body portion branching outward from the first elongate body portion at another intermediate location between the first end of the first elongate body portion and the intermediate location where the second elongate body branches outward from the first elongate body. The third elongate body portion may have a distal end forming a third tapered skewer. The third elongate body portion may be curved in one, two, or more orthogonal planes along at least a portion of the length of the third elongate body portion between a base end and a distal end of the third elongate body portion. The first, second, and third elongate body portions may each have different curvature a, and may each have similar or different lengths of one or more other elongate body portions of the garnish pick.
[0031] In at least some embodiments, hook 1220 formed at second end 1218 of first elongate body portion 1212 may branch outward from first elongate body portion 1212 at a location that is offset 1240 from second end 1218 of first elongate body portion 1212 . The hook may taper along its length toward a distal end 1221 of the hook. The hook formed at the second end of the first elongate body portion may be adapted to receive a rim of a beverage container 1300 (e.g., as depicted in FIG. 13 ). In at least some embodiments, a remainder of the pick body including at least the first and second elongate portions may be sized to fit substantially within a beverage container when or if the rim of the beverage container is received by the hook as depicted in FIG. 13 , for example. FIG. 13 shows garnish pick 1200 with example garnish 1310 .
[0032] In at least some embodiments, the pick body may be asymmetric about any plane (e.g., any or all reference planes) passing through the garnish pick. The pick body may comprise a core formed from a first material and an outer coating substantially surrounding the core, the outer coating formed from a second material that is different from the first material.
[0033] As yet another alternative description of an example garnish pick, a pick body of the garnish pick may include a stem portion (e.g., the portion of pick body 1212 between 1218 and 1232 ), a first elongate body portion (e.g., the portion of pick body 1212 between 1214 and 1232 ) branching from the stem portion, and a second elongate body portion (e.g., elongate body portion 1230 branching from the stem portion or the first elongate body portion. The first elongate body portion may taper from a base end toward a distal end of the first elongate body portion to form a first tapered skewer, and the second elongate body portion may taper from a base end toward a distal end of the second elongate body portion to form a second tapered skewer. The stem portion may form a hook as previously described.
[0034] While the foregoing written description enables one of ordinary skill to make and use what is considered presently to be the best mode thereof, those of ordinary skill will understand and appreciate the existence of variations, combinations, and equivalents of the specific embodiments, methods, and examples disclosed herein. Such disclosure and/or claimed subject matter should therefore not be limited by the above described embodiments, methods, and examples. | A garnish pick for food and/or beverages is disclosed. In at least some embodiments, the garnish pick includes a plurality of appendages that form skewering shafts for skewering garnishes. In at least some embodiments, at least one appendage of the garnish pick forms a hook for securing the garnish pick to a food or beverage container. In at least some embodiments, the garnish pick and its associated appendages may be shaped to simulate the appearance of organisms or portions thereof. As one example, the garnish pick may simulate the appearance of a branch of a tree or an antler of an animal. | big_patent |
FIELD OF THE INVENTION
The present invention generally relates to cardiac assist systems, including cardiomyoplasty, for the treatment of patients needing augmented cardiac output. More specifically, the present invention relates to a device and algorithm for a combined cardiomyostimulator and cardiac pacer-cardioverter-defibrillator.
BACKGROUND OF THE INVENTION
Cardiac assist systems aid patients with chronically and unacceptably low cardiac output who cannot have their cardiac output raised to acceptable levels by traditional treatments, such as drug therapy. One particular type of cardiac assist system currently used is a cardiomyoplasty.
Essentially a cardiomyoplasty provides a muscle-powered cardiac assist system. As seen in U.S. Pat. No. 4,813,952 of Khalafalla, incorporated herein by reference, the cardiomyoplasty is a cardiac assist system powered by a surgically-modified muscle tissue, such as the latissimus dorsi. In particular, the latissimus dorsi is wrapped around the heart. An implantable pulse generator is provided. The implantable pulse generator senses contractions of the heart via one or more sensing leads and stimulates the appropriate nerves of the muscle tissue with burst signals to cause the muscle tissue to contract in synchrony with the heart. As a result, the heart is assisted in its contractions, thereby raising the stroke volume and thus cardiac output. Besides delivering therapeutic electrical pulses to the muscle, the pulse generator is quite often also coupled so as to also provide therapeutic electrical pulses to the heart. See, for example, U.S. Pat. No. 4,735,205 of Chachques et al., incorporated herein by reference.
Patients with chronic cardiac output deficiencies, although treatable through cardiomyoplasty, face an increased risk for cardiac arrhythmic episodes, such as ventricular tachycardia or fibrillation. These arrhythmic episodes may be life-threatening.
In order to treat these potentially life-threatening cardiac arrhythmias, some cardiac assist systems have been proposed which combine a muscle stimulator as well as a cardiac pacer-cardioverter-defibrillator. In such a manner a patient who has had a cardiomyoplasty may, in addition to receiving musclepowered cardiac assistance, also receive various types of therapeutic cardiac electrical stimulation. One example of such a system may be seen in the U.S. Pat. No. 5,251,621 issued to Collins and entitled "Arrhythmia Control Pacer Using Skeletal Muscle Cardiac Graft Stimulation."
One problem associated with devices which combine a muscle stimulator as well as a cardiac pacer-cardioverter-defibrillator is that the muscle stimulation may interfere with the reliable sensing of cardiac events. During ventricular arrhythmias, such as ventricular fibrillation or ventricular tachycardia (hereafter "VF" and "VT" respectively) the cardiac signals may have very low amplitudes. This is especially the case during VF. The stimulation of the muscle wrap at that time could thus interfere with reliably sensing the VF or VT due to post-pace polarization, cross talk, et cetera.
The U.S. Pat. No. 5,251,621 issued to Collins offers one solution to this problem. The Collins patent discloses a cross channel blanking control signal to disable pacemaker sensing during generation of a skeletal muscle stimulation pulse. This is intended to prevent the pacemaker from incorrectly classifying a skeletal muscle stimulation pulse as an episode of intrinsic cardiac activity. At all times, however, muscle stimulation is continued. In fact, during arrhythmic events besides muscle stimulation continuing, Collins discloses adjusting various parameter of the muscle stimulation bursts, such as pulse amplitude, duration as well as the interval between pulses within a burst. One problem with this approach, however, is the continuation of skeletal muscle stimulation may interfere with the reliable sensing of the arrhythmia. Moreover, adjusting the various parameters of the muscle stimulation signal, such as amplitude or duration, creates an even greater likelihood that the device will not be able to reliably sense the arrhythmia.
Rapid detection of a cardiac tachyarrhythmia, and especially VF, is very important. A typical cardiac pacer-cardioverter-defibrillator detection algorithm requires the detection of a certain number of tachyarrhythmic events within a specified time period. In the case of VF detection, these devices will typically initiate the charging of a cardiac output circuit. This charging period may last between 1 to 21 seconds, depending on the therapy to be delivered. Following charging, the detection algorithm would once again confirm VF and deliver the therapy. Once the therapy was delivered, the detection algorithm would remain active until the tachyarrhythmic episode termination was confirmed.
At high energy levels, the period from tachyarrhythmia detection until tachyarrhythmia termination confirmation and muscle therapy reactivation could be extremely long, up to 35 seconds, or even longer. The consequence of this inhibition of the cardiac assistance during an episode of tachyarrhythmia is that cardiac output is highly compromised. In addition, while in fibrillation the threshold to achieve defibrillation through electrical shock rises exponentially. Higher defibrillation thresholds, however, mean the device must feature larger capacitors or higher voltages or both.
SUMMARY OF THE INVENTION
It is thus an object of the invention to provide a cardiac assist system which permits the rapid detection of a cardiac arrhythmia.
It is a further object of the present invention to provide a cardiac assist system which provides cardiac assistance during a cardiac arrhythmia.
These and other objects are met by the present invention which comprises a device and algorithm for a combined cardiomyostimulator and a cardiac pacer-cardioverter-defibrillator. In particular the present invention operates, in a first embodiment, to deliver stimulation to a skeletal muscle grafted about a heart; sense depolarizations of a patient's heart; measure the intervals separating successive depolarizations of the patient's heart; define first and second interval ranges; determine the number of the measured intervals falling within the first and second interval ranges; inhibit the delivery of stimulation to a skeletal muscle grafted about a heart upon the sensing of a depolarization within the first or second interval range; detect the occurrence of a first type of arrhythmia when the number of the measured intervals falling within the first interval range equals a first predetermined value; detect the occurrence of a second type of an arrhythmia when the number of the intervals falling within the second interval range equals a second predetermined value; deliver a first type of arrhythmia therapy in response to the detection of the first arrhythmia; and deliver a second type of arrhythmia therapy in response to the detection of the second arrhythmia, the second type of arrhythmia therapy having a cardiac stimulation component and a skeletal muscle component.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other aspects of the present invention will be best appreciated with reference to the detailed description of the invention in conjunction with the accompanying drawings, wherein:
FIG. 1 illustrates an example of a system for performing both long-term stimulation of skeletal muscles for cardiac assistance using systolic augmentation as well as direct electrical stimulation of a heart according to the present invention.
FIG. 2 is a functional schematic diagram of an implantable pulse generator used in the system of the present invention.
FIG. 3 is an illustration of detection interval ranges employed in a preferred embodiment of the present invention.
FIG. 4 is an arrhythmia detection/therapy muscle state diagram of the present invention.
FIG. 5 is a timing diagram showing the relationship between muscle stimulation, cardiac events, and a defibrillation charge cycle.
FIG. 6 is a timing diagram showing the relationship between muscle stimulation and cardiac events of an alternate embodiment.
FIG. 7 depicts an alternate muscle stimulation burst which may be used with the present system.
FIG. 8 depicts an alternate embodiment of the muscle catch stimulation which may be used with the present system.
FIG. 9 depicts an alternate embodiment of the muscle catch stimulation which may be used with the present system.
The drawings are not necessarily to scale.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention employs a sensor to monitor cardiac electrical activity and cardiac demand in a skeletal muscle-powered cardiac assist system (hereinafter referred to as "CAS"). A basic CAS may be configured in a variety of ways as described in the aforementioned patent to Khalafalla. One specific configuration is discussed herein simply as an illustration. The present invention, however, may be used in any system concerning cardiac augmentation using skeletal muscle, such as aortic counterpulsation or a skeletal muscle ventricle. Thus it should be understood the particular configuration illustrated is not intended to limit the present invention.
The System of the Present Invention
FIG. 1 illustrates an example of a system 1 for performing long-term stimulation of skeletal muscles for cardiac assistance using systolic augmentation as well as direct electrical stimulation of a heart 2. As seen, skeletal muscle graft 3 is positioned about the heart 2. In the preferred embodiment the latissimus dorsi muscle is used for the skeletal muscle graft, as is well known in the art. The longitudinal fibers of the muscle graft 3 are oriented generally perpendicular to the longitudinal axes of the right ventricle 4, left ventricle 5 and interventricular septum 10 of the heart. Muscle graft 3 is positioned in this manner so that when it is stimulated, muscle graft 3 compresses ventricles 4, 5 and particularly left ventricle 5, to thereby improve the force of right and left ventricular contraction. In such a manner the overall hemodynamic output of heart 2 is increased.
In a preferred configuration, muscle graft 3 is wrapped around the heart 2 and fixedly attached to itself to form a cup-shaped "sling," using running sutures 12. Alternatively, muscle graft 3 may be attached to heart 2 using running sutures 13 as illustrated.
As seen, electrical stimulation and sensing of heart 2 is accomplished through lead 15. In particular, lead 15 electrically couples pulse generator 6 to heart 2. Lead 15 provides cardiac pacing as well as defibrillation therapies. In the preferred embodiment lead 15 is the model 6936 tri-polar TRANSVENE lead from Medtronic Inc., Minneapolis, Minn. As seen, lead 15 is implanted in right ventricle 4 such that bipolar pacing electrode assembly 16 is in the right ventricular apex and defibrillation coil 17 is within the right ventricle 4. Although in the preferred embodiment a single lead is provided for pacing as well as defibrillation therapies, other types of lead configurations, such as multiple transvenous or subcutaneous or any combination thereof, may be used.
Muscle graft 3 is electrically stimulated through a pair of leads 21, 22. In particular leads 21, 22 couple pulse generator 6 to skeletal muscle graft 3. In the preferred embodiment leads 21, 22 are the model 4750 intramuscular lead from Medtronic, Inc., Minneapolis, Minn. As seen, each lead 21, 22 extends from pulse generator 6 to latissimus dorsi muscle graft 3. The electrodes (not shown) of each lead 21, 22 are placed to cause muscle graft 3 to contract when electrically stimulated, as is well known in the art. Other types of leads or electrodes, however, may be used, such as epimysial or neuromuscular leads or nerve cuff electrodes.
The Pulse Generator of the Present Invention
FIG. 2 is a functional block diagram of a pulse generator 6 in which the present invention may usefully be practiced. This diagram should only be taken, however, as exemplary of the type of device in which the invention may be embodied and not as limiting. It is believed the invention may usefully be practiced in a wide variety of device implementations. For example, the invention is also believed practicable in conjunction with the implantable muscle stimulator-pacemaker-cardioverters-defibrillators disclosed in U.S. Pat. No. 5,251,621 issued to Collins entitled "Arrhythmia Control Pacer Using Skeletal Muscle Cardiac Graft Stimulation."
The device is illustrated as being provided with six electrodes, 500, 502, 504, 506, 508, 572 and 574. Electrodes 500 and 502 may be a pair of electrodes located in the ventricle and mounted to a lead 15 as discussed above. Electrode 504 may correspond to a remote, indifferent electrode located on the housing of pulse generator 6. Electrodes 506 and 508 may correspond to large surface area defibrillation electrodes located within the right ventricle, coronary sinus, superior vena cava or may also be located subcutaneous, located on or part of the device housing or to the epicardium. Electrodes 572 and 574 are muscle stimulation electrodes coupled to the skeletal muscle wrap 3, as discussed above.
Electrodes 500 and 502 are switchable through switch matrix 512 to the R-wave detector circuit, comprising band-pass filter circuit 514, auto threshold circuit 516 for providing an adjustable sensing threshold as a function of the measured R-wave amplitude and comparator 518. A signal is generated on R-out line 564 whenever the signal sensed between electrodes 500 and 502 exceeds the present sensing threshold defined by the auto threshold circuit 516. As illustrated, the gain on the band pass amplifier 514 is also adjustable by means of a signal from the pacer timing and control circuitry 520 on GAIN ADJ line 566.
The operation of this R-wave detection circuitry may correspond to that disclosed in commonly assigned U.S. Pat. No. 5,118,824, issued to Keimel and incorporated herein by reference. However, alternative R-wave detection circuitry such as that illustrated in U.S. Pat. No. 4,819,643, issued to Menken and U.S. Pat. No. 4,880,004, issued to Baker et al., both incorporated herein by reference, may also be employed.
The threshold adjustment circuit 516 sets a threshold corresponding to a predetermined percentage of the amplitude of a sensed R-wave, which threshold decays to a minimum threshold level over a period of less than three seconds thereafter, similar to the automatic sensing threshold circuitry illustrated in the article "Reliable R-Wave Detection from Ambulatory Subjects", by Thakor et al., published in Biomedical Science Instrumentation, Vol. 4, pp. 67-72, 1978.
It is preferable that the threshold level not be adjusted in response to paced R-waves, but instead should continue to approach the minimum threshold level following paced R-waves to enhance sensing of low level spontaneous R-waves associated with tachyarrhythmias. The time constant of the threshold circuit is also preferably sufficiently short so that minimum sensing threshold may be reached within 1-3 seconds following adjustment of the sensing threshold equal to 70-80% of the amplitude of a detected spontaneous R-wave. The invention may also be practiced in conjunction with more traditional R-wave sensors of the type comprising a band pass amplifier and a comparator circuit to determine when the band-passed signal exceeds a predetermined, fixed sensing threshold.
Switch matrix 512 is used to select which of the available electrodes are coupled to band pass amplifier 534. Under control of microprocessor 524, switch matrix directs delivery of electrical stimulation pulses to cardiac tissue and the skeletal muscle wrap. Selection of the switch matrix settings is controlled by the microprocessor 524 via data/address bus 540. Signals from the selected electrodes are passed through band-pass amplifier 534 and into multiplexer 532, where they are convened to multi-bit digital signals by A/D converter 530, for storage in random access memory 526 under control of direct memory address circuit 528. Multiplexer 532 further receives voltage from battery 537 via VBATT 536.
Amplifier 534 may be a broad band pass amplifier, having a band pass extending for approximately 0.5 to 200 hertz. The filtered EGM signals from amplifier 534 are passed through multiplexer 532, and digitized in A-D converter circuitry 530. The digitized data may be stored in random access memory 526 under control of direct memory address circuitry 528.
The occurrence of an R-wave detect signal on line 564 is communicated to microprocessor 524 via data/address bus 540, and microprocessor 524 notes the time of its occurrence.
The remainder of the circuitry is dedicated to the provision of muscle stimulation, cardiac pacing, cardioversion and defibrillation therapies. The pacer timing/control circuitry 520 includes programmable digital counters which control the basic time intervals associated with cardiac pacing and muscle stimulation. The durations of these intervals are determined by microprocessor 524, and are communicated to the pacing circuitry 520 via address/data bus 540. Pacer timing/control circuitry also determines the amplitude of the muscle stimulation and cardiac pacing pulses and the gain of band-pass amplifier, under control of microprocessor 524.
During cardiac pacing or muscle stimulation, the escape interval counter within pacer timing/control circuitry 520 is reset upon sensing of an R-wave as indicated by a signal on line 564, and on timeout triggers generation of a pacing pulse by pacer output circuitry 522, which is coupled to electrodes 500 and 502 or electrodes 572 and 574. The escape interval counter is also reset on generation of a cardiac pacing pulse, and thereby controls the basic timing of cardiac pacing functions, including anti-tachycardia pacing and subsequent muscle stimulation. The duration of the interval deemed by the escape interval timer is determined by microprocessor 524, via data/address bus 540. The value of the count present in the escape interval counter when reset by sensed R-waves may be used to measure the duration of R-R intervals, to detect the presence of tachycardia and change muscle stimulation parameters.
Microprocessor 524 operates as an interrupt driven device, and responds to interrupts from pacer timing/control circuitry 520 corresponding to the occurrence of sensed R-waves and corresponding to the generation of cardiac pacing and muscle stimulation pulses. These interrupts are provided via data/address bus 540. Any necessary mathematical calculations to be performed by microprocessor 524 and any updating of the values or intervals controlled by pacer timing/control circuitry 520 and switch matrix 512 take place following such interrupts.
In the event that a tachyarrhythmia is detected, and an antitachyarrhythmia pacing regimen is desired, appropriate timing intervals for controlling generation of anti-tachycardia pacing therapies are loaded from microprocessor 524 into the pacer timing/control circuitry 520 and switch matrix 512.
Similarly, in the event that generation of a cardioversion or defibrillation pulse is required, microprocessor 524 employs the counters in timing and control circuitry 520 to control timing of such cardioversion and defibrillation pulses, as well as timing of associated refractory periods during which sensed R-waves are ineffective to reset the timing circuitry.
Further, in the event the onset of a tachyarrhythmia is detected, but not yet confirmed, the filtered and digitized EGM available at A/D 530 will be compared by microprocessor 524 with a value from RAM 526. Measured values above set will continue detection. Values below set confirm the arrhythmia if more than 50% of the X out of Y have been detected. In the preferred embodiment X and Y are programmable counts corresponding to the VFNID and the fibrillation event buffer memory (located in the RAM 526) respectively, both of which are discussed in more detail below with regards to the VF counting mode state 34 seen in FIG. 4. Microprocessor 524 will then initiate a therapy if programmed to do so.
In response to the detection of fibrillation or a tachycardia requiring a cardioversion pulse, microprocessor 524 activates cardioversion/defibrillation control circuitry 554, which initiates charging of the high voltage capacitors 556, 558, 560 and 562 via charging circuit 550, under control of high voltage charging line 552. During charging, microprocessor 524 enables pacer/timing control 520 to pace out 522 and switch matrix 512 to deliver muscle stimulation pulses until the high voltage capacitors 556 are sufficiently charged. The voltage on the high voltage capacitors is monitored via VCAP line 538, which is passed through multiplexer 532, and, in response to reaching a predetermined value set by microprocessor 524, results in generation of a logic signal on CAP FULL line 542, terminating charging. The CAP FULL line 542 signal is sent over DATA/ADDRESS 540 to the pace timer/control 520, which then inhibits delivery of the muscle stimulation pulses.
Thereafter, delivery of the timing of the defibrillation or cardioversion pulse is controlled by pacer timing/control circuitry 520. One embodiment of an appropriate system for delivery and synchronization of cardioversion and defibrillation pulses, and controlling the timing functions related to them is disclosed in more detail in the commonly assigned U.S. Pat. No. 5,188,105 by Keimel, Method and Apparatus for Detecting and Treating a Tachyarrhythmia, incorporated herein by reference. Any known cardioversion or defibrillation pulse generation circuitry, however, is believed usable in conjunction with the present invention. For example, circuitry controlling the timing and generation of cardioversion and defibrillation pulses as disclosed in U.S. Pat. No. 4,384,585, issued to Zipes, in U.S. Pat. No. 4,949,719 issued to Pless et al., cited above, and in U.S. Pat. No. 4,375,817, issued to Engle et el., all incorporated herein by reference may also be employed. Similarly, known circuitry for controlling the timing and generation of anti-tachycardia pacing pulses as described in U.S. Pat. No. 4,577,633, issued to Berkovits et el., U.S. Pat. No. 4,880,005, issued to Pless et el., U.S. Pat. No. 7,726,380, issued to Vollmann et el. and U.S. Pat. No. 4,587,970, issued to Holley et el., all of which are incorporated herein by reference may also be used.
In modern cardiac pulse generators, the particular anti-tachycardia and defibrillation therapies are programmed into the device ahead of time by the physician, and a menu of therapies is typically provided. For example, on initial detection of tachycardia, an anti-tachycardia pacing therapy may be selected. On re-detection of tachycardia, a more aggressive anti-tachycardia pacing therapy may be scheduled. If repeated attempts at anti-tachycardia pacing therapies fail, a higher level cardioversion pulse therapy may be selected thereafter. Prior art patents illustrating such pre-set therapy menus of antitachyarrhythmia therapies include the above-cited U.S. Pat. No. 4,830,006, issued to Haluska, et al., U.S. Pat. No. 4,727,380, issued to Vollmann et al. and U.S. Pat. No. 4,587,970, issued to Holley et al. The present invention is believed practicable in conjunction with any of the known anti-tachycardia pacing and cardioversion therapies, and it is believed most likely that the invention of the present application will be practiced in conjunction with a device in which the choice and order of delivered therapies is programmable by the physician, as in current cardiac pulse generators.
In addition to varying the therapy delivered following a failed attempt to terminate a tachyarrhythmia, it is also known that adjustment of detection criteria may be appropriate. For example, adjustment may comprise reducing the number of intervals required to detect a tachyarrhythmia to allow a more rapid redetection or by changing the interval ranges to bias detection towards detection of ventricular fibrillation, for example as disclosed in U.S. Pat. No. 4,971,058, issued to Pless et al and incorporated herein by reference.
In the present invention, selection of the particular electrode configuration for delivery of the cardioversion or defibrillation pulses is controlled via output circuit 548, under control of cardioversion/defibrillation control circuitry 554 via control bus 546. Output circuit 548 switches the high voltage electrodes 506 and 508 for delivery of the defibrillation or cardioversion pulse regimen, and may also be used to specify a multi-electrode, simultaneous pulse regimen or a multi-electrode sequential pulse regimen. Monophasic or biphasic pulses may be generated. One example of circuitry which may be used to perform this function is set forth in U.S. Pat. No. 5,163,427, issued to Keimel, incorporated herein by reference. However, output control circuitry as disclosed in U.S. Pat. No. 4,953,551, issued to Mehra et al. or U.S. Pat. No. 4,800,883, issued to Winstrom both incorporated herein by reference, may also be used in the context of the present invention. Alternatively single monophasic pulse regimens employing only a single electrode pair according to any of the above cited references which disclose implantable cardioverters or defibrillators may also be used.
Operation of the System of the Present Invention
FIG. 3 is an illustration of detection interval ranges which may be employed in a preferred embodiment of the present 'invention. The specific detection interval ranges are selected and programmed by the physician. As seen, events which occur less than 120 milliseconds (hereafter "ms") apart are not detected due to blanking. This is a fixed interval and its length is not programmable by the physician. The range of intervals between detected events taken as indicative of fibrillation are greater than 120 ms and less than 300 ms. That is the fibrillation detection interval (hereafter "FDI") extends to 300 ms. This range is programmed and is selected by the physician to suit the particular patient. The range of intervals between detected events taken as indicative of tachyarrhythmia are greater than 300 ms and less than 450 ms. That is the tachyarrhythmia detection interval (hereafter "TDI") extends to 450 ms. This range is also programmed and is selected by the physician to suit the particular patient. Events having intervals between 450 ms to 923 ms, in the preferred embodiment, are taken as indicative of normal sinus rhythm. That is the brady escape interval (hereafter "BEI") extends to 923 ms. This range is also programmed and is selected by the physician to suit the particular patient. Events which occur at intervals which would be greater than the BEI are taken as indicative of bradycardia.
For example, if a first event is sensed and a second event is sensed 200 ms later, ventricular fibrillation is provisionally detected. As a second example, if a first event is sensed and second event occurs 100 ms later and a third event occurs 210 ms after the second event, then a ventricular tachycardia (hereafter "VT") is provisionally detected. This is so because the second event occurred during blanking and thus was not sensed; the third event was thereafter sensed a sum of 320 ms after the first, well within the VT zone.
It should be noted that the specific times for intervals is for the preferred embodiment and thus is only illustrative of the present invention. Other interval lengths may also be used within the scope of the present invention.
FIG. 4 is an arrhythmia detection/therapy muscle state diagram of the present invention. As discussed above the present invention features skeletal muscle graft stimulation as well as cardiac stimulation. One of the important requirements of such a system, however, is to accurately detect cardiac arrhythmias and respond with the appropriate therapy. As discussed above, concurrent skeletal muscle graft stimulation may interfere with the detection and diagnosis of arrhythmias. Thus, one important feature of the present invention is the manner in which it provides for skeletal muscle graft stimulation as well as cardiac stimulation while also managing the prompt detection and diagnosis of arrhythmias. In particular, the present invention temporarily stops or inhibits skeletal muscle stimulation once the onset of an arrhythmia is sensed.
As seen, during normal sinus rhythm the system remains at normal sinus rhythm state 30. In state 30 device provides both skeletal muscle graft stimulation and any bradycardia stimulation required. Bradycardia stimulation may take the form of any suitable electrical stimulation therapy, and preferably is given in the form of VVI pacing, although other types of pacing therapy may be delivered, such as VOO, OVO and WT. Bradycardia stimulation is delivered, in the preferred embodiment, upon the detection of a sequence of cardiac events in which the range of intervals between detected events greater than BEI.
If, however, a sequence of cardiac events is detected in which the range of intervals between detected events is less than the TDI, then the skeletal muscle stimulation is inhibited (as represented by line 31) and VT counting mode state 32 is reached. In the preferred embodiment, if only one TDI is detected, then the skeletal muscle stimulation is inhibited and VT counting mode state 32 is reached.
While in the VT counting mode state 32, the skeletal muscle stimulation is re-enabled and the device returns to normal sinus rhythm state 30 if one interval greater than the TDI is detected.
In addition, when a sequence of cardiac events is detected in which the range of intervals between detected events is less than the FDI, then the skeletal muscle stimulation is inhibited (as represented by line 31) and VF counting mode state 34 is reached. In the preferred embodiment, if only one FDI is detected, then the skeletal muscle stimulation is inhibited and VF counting mode state 34 is reached.
While in the VF counting mode state 34, if VT detection is programmed on, the skeletal muscle stimulation is re-enabled and the device returns to normal sinus rhythm state 30 upon the detection of consecutive events with intervals greater than TDI equal to one-third of the number of intervals to detect VF (hereafter "VFNID"). If, however, VT detection is programmed off, the skeletal muscle stimulation is re-enabled and the device returns to normal sinus rhythm state 30 upon the detection of consecutive intervals greater than FDI equal to one-third of VFNID. Of course, if VT detection is programmed off, deliver VT therapy state 36 may still be reached through combined count state 38, discussed below.
It should be noted because FDI is smaller than TDI, then when VF counting mode state 34 is reached, this necessarily implies VT counting mode state 32 is also reached. From an electronic circuit design perspective, however, the counting bins for each state are simultaneously active, although both not necessarily registering events at the exact same time.
While in VT counting mode state 32 the device counts the number of events which meets the TDI criterion. When the cumulative VT event counter is equal to the number of intervals to detect VT, also called VTNID, then VT detection is fulfilled, deliver VT therapy state 36 is reached and VT therapy is delivered. In the preferred embodiment VTNID is programmable. As discussed in more detail below, VT detection and deliver VT therapy state 36 may also be reached through combined count state 38.
While in the VF counting mode state 34 the device counts the number of events which meet the FDI criterion. When the cumulative event counter is equal to VFNID, then VF detection is fulfilled, deliver VF therapy state 40 is reached and VF therapy is delivered. In the preferred embodiment VFNID is programmable. As discussed above, VFNID essentially is the number of past events that must satisfy the FDI criteria to be detected as fibrillation. The count uses past events that have been stored in the fibrillation event buffer memory (located in the RAM 526 of FIG. 2) which include both paced and sensed events. For example, if VFNID is set to 18 and fibrillation event buffer is set to 24; then to detect VF 18 of the last 24 events must satisfy the FDI criteria. As seen, deliver VF therapy state 40 may also be reached combined count state 38.
Combined count state 38 is provided to avoid excessive detection times during competing VT and VF counters. Thus combined count state 38 is reached, in the preferred embodiment, when the VF event counter reaches five and the VT event counter plus the VF event counter is greater than or equal to the combined number of intervals to detect parameter (hereafter "CNID"). In the preferred embodiment CNID is not directly programmable, but rather is equal to seven sixths of VFNID. Once the combined count state 38 is reached, then the second look criterion is applied.
Second look criterion is used only after combined count state 38 is reached. Second look criterion is applied to determine whether VT or VF therapy should be delivered. In the preferred embodiment second look criterion is as follows: If all of the previous 8 intervals are greater than or equal to FDI, then the VT detected path should be followed and deliver VT therapy state 36 is reached, but if one of the previous 8 intervals is less than FDI, then the VF detected path will be followed and deliver VF therapy state 40 is reached.
Once deliver VF therapy state 40 is reached, VF therapy is completed or aborted and VT/VF termination detection state 42 is reached. Similarly once deliver VT therapy state 36 is reached, VT therapy is completed or aborted and VT/VF termination detection state 42 is reached.
While in VT/VF termination detection state 42, the device determines whether VT or VF is re-detected. If either VT or VF is detected, then the device returns to the relevant therapy state. If neither VT nor VF is re-detected, the device returns to normal sinus state 30. VT/VF termination detection is accomplished as follows: If VT detection is programmed "Off" and eight consecutive events having intervals greater than FDI are sensed, then VF termination is detected and the device returns to normal sinus state 30. If VT detection is programmed "On" and eight consecutive events having intervals greater than TDI (which by definition is greater than FDI) are sensed, then VT termination is detected and the device returns to normal sinus state 30.
As discussed above the present invention also features skeletal muscle stimulation while charging for defibrillation. Essentially this feature provides muscle stimulation pulses to the grafted skeletal muscle while the device is charging a capacitor to deliver a defibrillation pulse. As mentioned above, because the muscle continues to contract and causes cardiac perfusion to be maintained. This cardiac perfusion, in turn, limits the increase in the overall defibrillation threshold. Because the increase in these thresholds is minimized, this permits the device to feature smaller capacitors or lower voltages or both.
FIG. 5 is a timing diagram showing the relationship between muscle stimulation, cardiac events and a defibrillation charge cycle. As seen, during normal sinus rhythm, represented here by normal QRS complex 202 the device is in normal sinus state 30. As such, muscle stimulation burst 201 is delivered to stimulate the skeletal muscle graft and thereby provide cardiac assistance, as described above. At first occurrence of a VF event 204 device enters detection state 206. As explained in FIG. 4, during detection state 206 device is in VF counting mode state 34 and VT counting mode state 32. As also explained in FIG. 4 once a VF event 204 is detected all muscle stimulation is inhibited, as may be seen in the lack of any muscle bursts in the region of detection state 206. Once VF is confirmed the device then enters deliver VF therapy state 40.
While in deliver VF therapy state 40, device performs several operations, including charging of the output capacitors, depicted as line 208. In addition, skeletal muscle stimulation is re-initiated and a series of asynchronous muscle stimulation bursts 210, 212 are delivered. In the preferred embodiment asynchronous bursts 210, 212 have a greater amplitude than muscle stimulation burst 201, on the order of one and a half times as large.
Once charging of the output capacitors is completed, a sequence to synchronize the defibrillation discharge to a sensed R-wave is undertaken. In particular, device begins a synchronization sequence during synchronization time 216. Synchronization sequence is undertaken to synchronize defibrillation discharge to a sensed cardiac event as well as to re-confirm the presence of the arrhythmia. If the synchronization sequence is successful, then defibrillation discharge 214 is delivered synchronized to a sensed cardiac event. If the synchronization sequence is unsuccessful, then defibrillation discharge 214 is delivered at the timing out of synchronization time 216. In addition during synchronization time 216, device re-inhibits skeletal muscle stimulation in order to permit reliable sensing of any intrinsic cardiac events.
FIG. 6 is a timing diagram showing the relationship between muscle stimulation and cardiac events of an alternate embodiment. In particular, in an alternate embodiment, if synchronization is unsuccessful, then the device delivers an asynchronous muscle stimulation burst 322 immediately prior to defibrillation discharge 214, as best seen in FIG. 6. Muscle stimulation burst 322 is intended to cause the heart to be squeezed by the skeletal muscle graft and achieve roughly a systolic position when defibrillation discharge 214 is delivered. Because the volume of the heart in such a position is decreased the defibrillation threshold is likewise decreased.
Turning again to FIG. 5, once defibrillation discharge 214 is delivered, then device enters into VT/VF termination detection state 42 to thereby confirm heart has returned to normal sinus rhythm.
FIG. 7 depicts an alternate muscle stimulation burst which may be used with the present system. These muscle stimulation bursts may be used at any suitable time within the present system, and are not limited to only use prior to delivery of the defibrillation therapy. As seen muscle stimulation burst 300 occurs after QRS 303 in the amount of a synchronization delay 305. In the preferred embodiment synchronization delay 305 is programmable and is undertaken in order to synchronize the muscle stimulation burst 300 with the ventricular contraction. Muscle stimulation burst 300 has essentially two sections, first section 301 and second section 302, often referred to as "muscle catch" and "muscle pulse train" respectively. As seen, first section 301 has a smaller interpulse interval 304 within the burst, i.e. a higher frequency. In comparison second section 302 has a relatively larger interpulse interval 304 within the burst, i.e. a relatively smaller frequency. The higher frequency first section 301 increases the velocity and force of the skeletal muscle graft contraction. In the preferred embodiment interpulse interval 304 and number of pulses in the catch may be selected by the physician. The pulse waveform, amplitude 308 and width of the muscle catch are the same for the remainder of the burst.
FIG. 8 depicts an alternate embodiment of the muscle catch stimulation which may be used with the present system. As seen all parameters of the muscle stimulation burst 300 are the same as that described above with respect to FIG. 7 but for the amplitude of second section 302.
FIG. 9 depicts an alternate embodiment of the muscle catch stimulation which may be used with the present system. As seen all parameters of the muscle stimulation burst 300 are the same as that described above with respect to FIG. 7 but for the amplitude of second section 302. In particular amplitude of each burst within second section 302 decreases. The rate of decrease of pulse amplitude within each burst decreases as a function of rate, i.e. the faster the rate of muscle stimulation, the greater the decrease of pulse amplitude within the pulse train.
As discussed above, the mechanically induced cardiac output augmentation of the present invention during VF (which is associated with loss of cardiac output) leads to maintaining defibrillation thresholds during prolonged episodes of fibrillation, thus resulting in longer battery life or smaller device size or both. It also permits a longer charging interval without the concern of a dangerously low or temporarily lost cardiac output.
While the present invention has been described in detail with particular reference to a preferred embodiment, it will be understood variations and modifications can be effected within the scope of the following claims. Such modifications may include substituting elements or components which perform substantially the same function in substantially the same way to achieve substantially the same result for those described herein. | A device and algorithm for a combined cardiomyostimulator and a cardiac pacer-cardioverter-defibrillator. In particular the present device operates, in a first embodiment, to deliver stimulation to a skeletal muscle grafted about a heart; sense depolarizations of a patient's heart; measure the intervals separating successive depolarizations of the patient's heart; define first and second interval ranges; determine the number of the measured intervals falling within the first and second interval ranges; inhibit the delivery of stimulation to a skeletal muscle grafted about a heart upon the sensing of a depolarization within the first or second interval range; detect the occurrence of a first type of arrhythmia when the number of the measured intervals falling within the first interval range equals a first predetermined value; detect the occurrence of a second type of an arrhythmia when the number of the intervals falling within the second interval range equals a second predetermined value; deliver a first type of arrhythmia therapy in response to the detection of the first arrhythmia; and deliver a second type of arrhythmia therapy in response to the detection of the second arrhythmia, the second type of arrhythmia therapy having a cardiac stimulation component and a skeletal muscle component. | big_patent |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of International Patent Application No. PCT/US2014/063473 filed Oct. 31, 2014, which claims the benefit of Provisional Patent Application No. 61/899,106 filed Nov. 1, 2013, both of which are hereby incorporated by reference.
FIELD OF THE INVENTION
[0002] The invention relates generally to an accommodating intraocular lens device and, more particularly, to an accommodating intraocular lens device configured for implantation in a lens chamber of a subject's eye.
BACKGROUND
[0003] Surgical procedures on the eye have been on the rise as technological advances permit for sophisticated interventions to address a wide variety of ophthalmic conditions. Patient acceptance has increased over the last twenty years as such procedures have proven to be generally safe and to produce results that significantly improve patient quality of life.
[0004] Cataract surgery remains one of the most common surgical procedures, with over 16 million cataract procedures being performed worldwide. It is expected that this number will continue to increase as average life expectancies continue to rise. Cataracts are typically treated by removing the crystalline lens from the eye and implanting an intraocular lens (“IOL”) in its place. As conventional IOL devices are primarily focused for distance visions, they fail to correct for presbyopia and reading glasses are still required. Thus, while patients who undergo a standard IOL implantation no longer experience clouding from cataracts, they are unable to accommodate, or change focus from near to far, from far to near, and to distances in between.
[0005] Surgeries to correct refractive errors of the eye have also become extremely common, of which LASIK enjoys substantial popularity with over 700,000 procedures being performed per year. Given the high prevalence of refractive errors and the relative safety and effectiveness of this procedure, more and more people are expected to turn to LASIK or other surgical procedures over conventional eyeglasses or contact lens. Despite the success of LASIK in treating myopia, there remains an unmet need for an effective surgical intervention to correct for presbyopia, which cannot be treated by conventional LASIK procedures.
[0006] As nearly every cataract patient also suffers from presbyopia, there is convergence of market demands for the treatment of both these conditions. While there is a general acceptance among physicians and patients of having implantable intraocular lens in the treatment of cataracts, similar procedures to correct for presbyopia represent only 5% of the U.S. cataract market. There is therefore a need to address both ophthalmic cataracts and/or presbyopia in the growing aging population.
BRIEF SUMMARY
[0007] The intraocular lens (IOL) device described herein generally comprise two lens portions. In a preferred embodiment, a first lens portion provides most, if not all, of the accommodative power and a second base lens provides most, if not all, of the corrective refractive power that is needed by a particular patient. Because the first lens portion must provide an accommodative power, it must respond by either changing shape or by displacement along an optical axis in response to the contraction and relaxation of the ciliary muscles which control the eye's natural ability to accommodate. To that end, the first lens portion may be provided as an elastically deformable lens chamber that is filled with a fluid or gel. In contrast to the elastically deformable lens chamber, the base lens is configured to not readily deform or change its curvature in response to the radially compressive forces exerted on the circumferential edge. The transfer of the radially compressive forces onto the lens chamber may be accomplished by incorporating one or more of the following features in the IOL: (1) the opposing sides of the lens chamber having a reduced thickness as compared to the base lens, (2) a hinge disposed between the base lens and the peripheral portion, (3) the lens chamber being made of a material having a lower Young's modulus than the base lens, and/or (4) the base lens being made of a substantially rigid material.
[0008] In one embodiment, an intraocular lens (IOL) device is provided. The IOL comprises a first lens comprising a pair of opposing and deformable surfaces and a cavity defined therebetween, the first lens having a first lens diameter, a second lens having a second lens diameter, and a circumferential haptic having an outer peripheral edge, the circumferential haptic coupling the first lens and the second lens. A main IOL cavity is defined by the circumferential haptic, the first lens and the second lens. The IOL device is resiliently biased to an unaccommodated state being characterized by the IOL device having a first diameter d 1 in the absence of radial compressive forces exerted on the outer peripheral edge. The IOL device actuates to an accommodated state characterized by a second diameter d 2 in response to radial compressive forces exerted on the outer peripheral edge, wherein d 1 >d 2 .
[0009] In accordance with a first aspect, the first lens is a biconvex lens.
[0010] In accordance with a second aspect, the cavity is fully enclosed.
[0011] In accordance with a third aspect, the IOL further comprises a gel in the cavity. The gel preferably has a refractive index of 1.46 or greater, preferably 1.48 or greater and most preferably 1.55 or greater. The gel preferably has a Young's modulus of 10 psi or less, preferably 5 psi or less, and more preferably 1 psi or less. In a particularly preferred embodiment, the gel has a Young's modulus of 0.5 psi or less, preferably 0.25 psi or less, and most preferably 0.01 psi or less. The gel preferably is a highly-branched polymer, preferably cross-linked silicone.
[0012] In accordance with a fourth aspect, the second lens is a one of a plano-convex lens, a bi-convex lens and a positive meniscus lens.
[0013] In accordance with a fifth aspect, the second lens is substantially more rigid than the first lens.
[0014] In accordance with a sixth aspect, the IOL further comprises a hinge disposed between the circumferential haptic and the second lens. In a preferred embodiment, in the presence of the compressive forces on the peripheral edge, the hinge directs a substantial portion of the compressive forces onto the first lens to cause a greater proportionate reduction in the first lens diameter to be reduced proportionately than in the second lens diameter.
[0015] In accordance with a seventh aspect, each of the opposing and deformable surfaces of the first lens has a thickness that is 50% or less of the second lens, preferably 25% or less of the second lens, and more preferably, 10% or less of the second lens.
[0016] In accordance with an eighth aspect, the IOL further comprises one or both of a plurality of apertures disposed on the circumferential haptic and a circumferential channel defined within the circumferential haptic. The plurality of apertures may be in fluid communication with the main IOL cavity. The plurality of apertures may be in fluid communication with both the circumferential channel and the main IOL cavity.
[0017] In accordance with a ninth aspect, the IOL device further comprises a plurality of raised bumps, wherein at least one of the plurality of raised bumps is positioned adjacent to each one of the plurality of apertures.
[0018] In accordance with a tenth aspect, the IOL device further comprises a plurality of troughs, at least one of the plurality of troughs extending radially inward from each one of the plurality of apertures to facilitate fluid flow into the apertures.
[0019] In accordance with an eleventh aspect, the circumferential haptic comprises a plurality of radial arms coupling the second lens, the plurality of radial arms defining apertures therebetween to permit fluid communication with the main cavity.
[0020] In accordance with a twelfth aspect, the circumferential haptic comprises a third circumferential cavity disposed peripherally of the main IOL cavity.
[0021] In accordance with a thirteenth aspect, the opposing surfaces of the first lens are displaced away from each other upon the application of a radial force along the circumferential haptic. The opposing surfaces comprises central and peripheral regions and a gradually increasing thickness profile from the peripheral to the central regions.
[0022] In another embodiment, an IOL is provided. The IOL comprises a first lens made of an elastic and deformable material having a first Young's modulus, a second lens in spaced relation to the first lens along a central optical axis and a circumferential portion encircling the first and second lens, the circumferential portion comprising an outer peripheral edge. At least one of a portion of the second lens and a portion of the circumferential portion is made of a material having a second Young's modulus. The first Young's modulus is less than the second Young's modulus.
[0023] In accordance with a first aspect, only the second lens is made of the material having the second Young's modulus.
[0024] In accordance with a second aspect, only the portion of the circumferential portion is made of the material having the second Young's modulus.
[0025] In accordance with a third aspect, the first Young's modulus is about 100 psi or less.
[0026] In accordance with a fourth aspect, the second Young's modulus is about 100 psi or greater.
[0027] In accordance with a fifth aspect, the second Young's modulus is about 150 psi or greater.
[0028] In accordance with a sixth aspect, the first lens comprises a pair of opposing and deformable surfaces and a cavity defined therebetween, the first lens having a first lens diameter and wherein a main IOL cavity is defined between the first lens, the second lens and the circumferential portion.
[0029] In accordance with a seventh aspect, the IOL further comprises a hinge disposed on the second lens outside of the active optical area.
[0030] In accordance with an eighth aspect, the first lens is comprised of two opposing surfaces which are displaced away from each other upon the application of a radial force along a peripheral edge. The two opposing surfaces each having central and peripheral regions, wherein the central region has a thickness that is at least 2 times, preferably at least three times, and most preferably at least four times greater than a thickness of the peripheral region.
[0031] In a further embodiment, an IOL is provided. The IOL comprises a first lens, a second lens in spaced relation to the first lens and a circumferential haptic coupling the first and second lens. The first lens comprises opposing sides and an enclosed cavity between the opposing sides. The opposing sides each have central and peripheral regions, the central region being disposed around an optical axis, the peripheral region being disposed around the central region. The central region is at least two times thicker than the peripheral region. The second lens in spaced relation to the first lens, the second lens having a thickness that is greater than either one of the opposing sides of the first lens. A circumferential haptic has an outer peripheral edge configured for engagement with a capsular bag of an eye when the IOL is implanted. A main IOL cavity is defined by the circumferential haptic, the first lens and the second lens.
[0032] In accordance with a first aspect, the central region is at least three times thicker than the peripheral region.
[0033] In accordance with a second aspect, the central region is at least four times thicker than the peripheral region.
[0034] In accordance with a third aspect, the enclosed cavity of the first lens comprises a gel having a first refractive index.
[0035] In accordance with a fourth aspect, the opposing sides of the first lens has a second refractive index that is less than the first refractive index of the gel.
[0036] In accordance with a fifth aspect, the gel is a vinyl-terminated phenyl siloxane.
[0037] In accordance with a sixth aspect, the gel has a Young's modulus of 0.25 psi or less, preferably 0.01 psi or less.
[0038] Other objects, features and advantages of the described preferred embodiments will become apparent to those skilled in the art from the following detailed description. It is to be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the present invention, are given by way of illustration and not limitation. Many changes and modifications within the scope of the present invention may be made without departing from the spirit thereof, and the invention includes all such modifications.
BRIEF DESCRIPTION OF THE DRAWINGS
[0039] Illustrative embodiments of the present disclosure are described herein with reference to the accompanying drawings, in which:
[0040] FIGS. 1A-1B are perspective and side cross-sectional views, respectively, of an embodiment of a dual-cavity IOL device.
[0041] FIG. 2 is a perspective cross-sectional view of another embodiment of a dual-cavity IOL device having holes disposed on the top surface.
[0042] FIGS. 3A-3B are front and perspective cross-sectional views of another embodiment of a dual-cavity IOL device having through-holes disposed through the top and bottom surfaces in communication with the main cavity.
[0043] FIG. 4 is a perspective cross-sectional view of another embodiment of a dual-cavity IOL device having through-holes disposed through the top and bottom surfaces and which are not in fluid communication with the main cavity.
[0044] FIGS. 5A-5B are perspective cross-sectional views of another embodiment of a dual-cavity IOL device comprising arc-shaped cutouts on the bottom surface to provide a fluid communication with the main cavity.
[0045] FIGS. 6A-6B are perspective cross-sectional and rear views of another embodiment of a dual-cavity IOL device comprising arch-shaped cutouts on the bottom surface and a plurality of peripheral through holes in communication with a circumferential channel.
[0046] FIG. 7A-7B are top perspective and cross-sectional views of another embodiment of a dual-cavity IOL device comprising a plurality of raised protrusions adjacent through-holes which are in communication with the main cavity and circumferential channel.
[0047] FIG. 8A-8B are top perspective and cross-sectional views of another embodiment of a dual-cavity IOL device comprising a plurality of troughs adjacent through-holes which are in communication with the main cavity and circumferential channel.
[0048] FIG. 9 is a partial cross-sectional view of an embodiment of the IOL device, cut away along the optical axis A-A.
[0049] FIGS. 10A-10B are cross-sectional views of further embodiments of the IOL device.
[0050] FIG. 11A depicts the human eye with the lens material removed following a capsulorhexis.
[0051] FIGS. 11B-11C depict the implanted IOL device in the unaccommodated and accommodated states, respectively.
[0052] Like numerals refer to like parts throughout the several views of the drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0053] Specific, non-limiting embodiments of the present invention will now be described with reference to the drawings. It should be understood that such embodiments are by way of example and are merely illustrative of but a small number of embodiments within the scope of the present invention. Various changes and modifications obvious to one skilled in the art to which the present invention pertains are deemed to be within the spirit, scope and contemplation of the present invention as further defined in the appended claims.
[0054] FIGS. 1A-1B depicts a basic structure of an embodiment of the accommodating intraocular lens (IOL) 100 . The IOL 100 is depicted as comprising an elastically deformable lens chamber 110 , a base lens 150 , and a lens periphery 170 coupling the lens chamber 110 and the base lens 150 . The elastically deformable lens chamber 110 provides most, if not all, of the accommodative power by deforming or changing in curvature in response to the radially compressive forces that are exerted onto the IOL 100 during accommodation. The base lens 150 provides most, if not all, of the corrective refractive power that is required by a particular patient and is not required to deform or change in shape or curvature. Thus, the lens chamber 110 and the base lens 150 cooperate to restore both a patient's vision and natural range of accommodation.
[0055] The lens chamber 110 is made of an elastically deformable material and comprises opposing sides 112 and 114 that are joined together at the periphery of the lens chamber 110 to define a bi-convex exterior shape and an internal enclosed cavity 120 . Each of the opposing sides 112 and 114 comprise a central region 112 a , 114 a and a peripheral region 112 b , 114 b and a gradient of thickness that increases radially from the peripheral region 112 b , 114 b to the central region 112 a , 114 a . This thickness profile is intended to encourage deformation of the opposing sides 112 , 114 away from one another and to permit the opposing sides to bulge and increase its curvature in opposing directions along an optical axis A-A without causing the membrane to buckle about the central region 112 a , 114 a . Thus, while the conventional wisdom suggests that a greater degree of deformation and outward bulging would be achieved with the opposite thickness profile (e.g., a thickness profile that decreases radially from the peripheral region 112 b , 114 b to the central region 112 a , 114 a ), such a thickness profile is more likely to cause the lens chamber 110 to buckle or collapse inwardly about the central region 112 a , 114 a upon the application of a radially compressive force once implanted in a patient's eye. During accommodation, the application of radially compressive forces may cause an internal vacuum to develop inside the lens chamber 110 , thereby causing the opposing sides 112 , 114 to buckle inwardly.
[0056] Thus, in a particularly preferred embodiment, the opposing sides have a gradually increasing thickness from the peripheral regions 112 b , 114 b , to the central region 112 a , 114 a . In a preferred embodiment, the central region 112 a , 114 a , as measured along the optical axis A-A, has a thickness that is two times or more, preferably three times or more, and most preferably four times or more than the thickness of the peripheral region 112 b , 114 b , as measured just adjacent to the area where the opposing sides 112 , 114 join at the peripheral region. In another preferred embodiment, the point of greatest thickness in the central region 112 a , 114 a and the point of least thickness in the peripheral regions 112 b , 114 b is characterized as having a thickness ratio of 2:1 or greater, preferably 3:1 or greater, and most preferably 4:1 or greater. In one embodiment, the central region 112 a , 114 a , as measured along the optical axis A-A, comprises an area of thickness that is about 100 microns, preferably about 200 microns, and the peripheral region 112 b , 114 b comprises an area of thickness that is about 50 microns as measured just adjacent to the area where the opposing sides 112 , 114 join at the peripheral region. While the thickness profile is described in relation to FIGS. 1A-1B , it is understood that the same or a substantially similar thickness profile may be provided for all of the IOL devices depicted and described herein.
[0057] The base lens 150 is coupled to the lens chamber 110 via a lens periphery 170 . The base lens 150 may be a positive lens that provides convergent power, such as a bi-convex, plano-convex or a positive meniscus lens. Alternatively, the base lens 150 may be a negative lens that provides divergent power, such as a bi-concave, plano-concave or a negative meniscus lens. The base lens 150 depicted in FIGS. 1A-1B is a positive meniscus lens.
[0058] The base lens 150 is preferably more rigid than the opposing sides 112 , 114 of the lens chamber 110 . The greater rigidity may be imparted by providing a base lens 150 having a thickness that is significantly greater than the thicknesses of the opposing sides 112 , 114 of the lens chamber 110 . Alternatively or in addition to providing a greater thickness, the base lens 150 may be made of a different or stiffer material having a higher elastic Young's modulus as compared to the lens chamber 110 . The base lens 150 preferably does not substantially change its shape and curvature in response to the radially-compressive accommodative force applied onto the peripheral edge 180 of the lens periphery 170 . Instead, the radially compressive accommodative forces are transferred onto the lens chamber 110 to cause the desired deforming changes.
[0059] In a preferred embodiment, the base lens 150 is substantially thicker than one of the opposing sides 112 , 114 of the lens chamber 110 , as measured along the optical axis A-A. In a preferred embodiment, the thickness of each one of the opposing sides 112 , 114 of the lens chamber 110 , as along the optical axis A-A depicted in FIGS. 1A-1B and 9 , is less than ½, preferably less than ⅓, preferably less than ¼, and most preferably less than ⅕ of the thickness of the base lens 150 at the central optical axis A-A. Because the base lens 150 is substantially thicker than either one of the opposing sides 112 , 114 of the lens chamber 110 , the base lens 150 has an effective Young's modulus that is substantially greater than either one of the opposing sides 112 , 114 of the lens chamber 110 . While FIGS. 1A-1B and 9 depict the relative thickness of the opposing sides 112 , 114 of the lens chamber 110 and the base lens 150 for IOL 100 , it is understood that all of the IOL devices disclosed herein may have the same or similar thickness profile with respect to the lens chamber 110 and the base lens 150 .
[0060] The lens chamber 110 and the base lens 150 are coupled together by a lens periphery 170 . The lens periphery 170 comprises a circumferential edge 180 configured to engage a circumferential region of the capsular bag of the eye. As depicted in FIGS. 11A-11C , the circumferential region 52 is where the capsular bag 40 is coupled to the zonules 50 , generally at a location where the density of the zonules 50 is the greatest. The zonules 50 , in turn, couple the capsular bag 40 to the ciliary muscles 60 which contract and relax to provide a range of accommodation. While FIGS. 11B and 11C depict a particularly preferred embodiment in which an IOL 100 is implanted with the lens chamber 110 being oriented anteriorly within the lens capsule 40 of the eye, it is understood that the IOL 100 may also be implanted with the lens chamber 110 being oriented posteriorly within the lens capsule 40 of the eye.
[0061] The lens periphery 170 comprises a radial portion 172 and a circumferential hinge 174 that cooperate together to transmit a significant portion, if not most, of the radially compressive forces exerted onto the circumferential edge 180 onto the lens chamber 110 and away from the base lens 150 . Referring back to FIGS. 1A-1B , the radial portion 172 extends radially inwardly from the lens periphery 170 to the lens chamber 110 and the hinge 174 is disposed between the lens periphery 170 and the base lens 150 . Both the radial portion 172 and the hinge 174 cooperate to maximize the extent to which the radially-compressive accommodative forces applied to the peripheral edge 180 are transmitted to the lens chamber 110 . The greater the force transmitted to the lens chamber 110 , the greater the deformation and change of curvature of the opposing sides 112 , 114 of the lens chamber 110 .
[0062] The lens periphery 170 may be solid and thickened as compared to the base lens 150 , as depicted in FIGS. 1A-1B and 9 . Alternatively, the lens periphery 170 may comprise a hollow space or a circumferential channel to reduce the delivery profile of the IOL, as depicted in FIGS. 2, 3A, 3B, 4, 6, 7, and 8 . Because the IOL 100 is implanted into a relatively small incision size, it must be rolled up to assume a delivery profile that is at least as small as the incision size.
[0063] The circumferential hinge 174 is provided as a thinned or grooved area disposed in the lens periphery 170 and surrounding the base lens 150 . The circumferential hinge 174 permits the lens periphery 170 to pivot radially inwardly towards the lens chamber 110 such that the radially compressive forces applied to the circumferential edge 180 are directed substantially along the radial portion 172 and applied to the lens chamber 110 , as opposed to being applied to the base lens 150 , which is configured to generally resist deformation (See FIG. 11C ). Thus, the radial portion 172 is itself preferably sufficiently rigid in order to substantially transmit the radial compressive force onto the lens chamber 110 . In a preferred embodiment, the hinge 174 is provided both peripherally and circumferentially around the base lens 150 as a thinned area or as a groove.
[0064] FIGS. 11B and 11C depicts the configuration of the IOL 100 in the absence of a radial compressive force applied to the circumferential peripheral edge 180 ( FIG. 11B , an unaccommodated eye) and in the presence of a radial compressive force applied to the circumferential peripheral edge 180 ( FIG. 11C , an accommodated eye) in which the peripheral edge 180 tilts in the direction C about the hinge 174 , transmitting the radial compressive forces onto the lens chamber 110 , and thereby causing the opposing sides 112 , 114 of the lens chamber 110 to be displaced apart from one another and increase in curvature.
[0065] The features described herein which are intended to maximize the extent to which the radially compressive forces are transmitted to a lens chamber 110 and thus provide a large range of accommodation. The IOLs described herein may further be made of a material that does not resist deformation or is characterized as having a low Young's modulus. The IOLs may be made of a single material or, alternatively, different portions of the IOL may be made of different materials having differing Young's modulus (see FIGS. 10A-10B ).
[0066] In one preferred embodiment, at least the opposing sides 112 , 114 of the lens chamber 110 is made of a material of sufficient mechanical strength to withstand physical manipulation during implantation, but is of sufficiently low Young's modulus so as to minimize its resistance to deformation. In a preferred embodiment, the opposing sides 112 , 114 of the lens chamber 110 is made of a polymer having a Young's modulus of 100 psi or less, preferably 75 psi or less, and most preferably 50 psi or less. In one preferred embodiment, the remaining portions of the IOL 100 (e.g., the base lens 150 , the peripheral portion 170 ) has a Young's modulus that is greater than the Young's modulus of the walls 112 , 114 , of the lens chamber 110 . The walls 112 , 114 of the lens chamber 110 may be a polymer, preferably a silicone polymer and, more preferably a phenyl siloxane, such as a vinyl-terminated phenyl siloxane or a vinyl-terminated diphenyl siloxane. In order to impart sufficient mechanical strength, the polymer may be crosslinked, reinforced with fillers, or both. The fillers may be a resin or silica that have been functionalized to react with the polymer.
[0067] The opposing sides 112 , 114 of the lens chamber 110 defines an enclosed cavity 120 that is filled with a fluid or gel having specific physical and chemical characteristics to enhance the range of refractive power provided by the IOL during accommodation. The fluid or gel is selected such that it cooperates with the walls 112 , 114 of the lens chamber 110 in providing a sufficient range of accommodation of up to at least 3 diopters, preferably up to at least 5 diopters, preferably up to at least 10 diopters and most preferably up to at least 15 diopters. In a preferred embodiment, the enclosed cavity 120 is filled with the fluid or gel before implantation of the IOL 100 into the capsular bag 40 of the eye and, in a more preferred embodiment, the cavity 120 is filled with the fluid or gel in the manufacture of the IOL 100 .
[0068] In one preferred embodiment the enclosed cavity 120 is filled with a fluid, such as a gas or a liquid, having low viscosity at room temperature and a high refractive index. In a preferred embodiment, the fluid is a liquid having a viscosity of 1,000 cP or less at 23° C. and a refractive index of at least 1.46, 1.47, 1.48, or 1.49. The fluid may be a polymer, preferably a silicone polymer, and more preferably a phenyl siloxane polymer, such as a vinyl-terminated phenyl siloxane polymer or a vinyl-terminated diphenyl siloxane polymer. Preferably, in embodiments where the fluid is made of a polymer, the polymer is preferably not crosslinked and that the polymer may be linear or branched. Where the fluid is a vinyl-terminated phenyl siloxane polymer or diphenyl siloxane polymer, the vinyl groups may be reacted to form other moieties that do not form crosslinkages.
[0069] In accordance with one embodiment, fluid may be a polyphenyl ether (“PPE”), as described in U.S. Pat. No. 7,256,943, entitled “Variable Focus Liquid-Filled Lens Using Polyphenyl Ethers” to Teledyne Licensing, LLC, the entire contents of which are incorporated herein by reference as if set forth fully herein.
[0070] In accordance with another embodiment, the fluid may be a fluorinated polyphenyl ether (“FPPE”). FPPE has the unique advantage of providing tunability of the refractive index while being a chemically inert, biocompatible fluid with low permeability in many polymers. The tunability is provided by the increasing or decreasing the phenyl and fluoro content of the polymer. Increasing the phenyl content will effectively increase the refractive index of the FPPE, whereas increasing the fluoro content will decrease the refractive index of the FPPE while decreasing the permeability of the FPPE fluid through the walls 112 , 114 of the lens chamber 110 .
[0071] In another preferred embodiment, the enclosed cavity 120 is filled with a gel. The gel preferably has a refractive index of at least 1.46, 1.47, 1.48, or 1.49. The gel may also preferably have a young's modulus of 20 psi or less, 10 psi or less, 4 psi or less, 1 psi or less, 0.5 psi or less, 0.25 psi or less and 0.01 psi or less. In a preferred embodiment, the gel is a crosslinked polymer, preferably a crosslinked silicone polymer, and more preferably a crosslinked phenyl siloxane polymer, such a crosslinked vinyl-terminated phenyl siloxane polymer or a vinyl-terminated diphenylsiloxane polymer. Other optically clear polymer liquids or gels, in addition to siloxane polymers, may be used to fill the cavity 120 and such polymers may be branched, unbranched, crosslinked or uncrosslinked or any combination of the foregoing.
[0072] A gel has the advantages of being extended in molecular weight from being crosslinked, more self-adherent and also adherent to the walls or opposing sides or walls 112 , 114 of the lens chamber 110 than most liquids. This makes a gel less likely to leak through the walls 112 , 114 of the lens chamber 110 . In order to obtain the combination of accommodative power with relatively small deformations in the curvature of the walls 112 , 114 of the lens chamber 110 , the gel is selected so as to have a high refractive index while being made of an optically clear material that is characterized as having a low Young's modulus. Thus, in a preferred embodiment, the gel has a refractive index of 1.46 or greater, preferably 1.47 or greater, 1.48 or greater and most preferably 1.49 or greater. At the same time, the gel preferably has a Young's modulus of 10 psi or less, preferably 5 psi or less, and more preferably 1 psi or less. In a particularly preferred embodiment, the gel has a Young's modulus of 0.5 psi or less, preferably 0.25 psi or less, and most preferably 0.01 psi or less. It is understood that at lower Young's modulus, the gel will present less resistance to deformation and thus the greater the deformation of the walls 112 , 114 of the lens chamber 110 for a given unit of applied force.
[0073] In particularly preferred embodiment, the gel is a vinyl-terminated phenyl siloxane that is produced based on one of the four formulas provided as follows:
[0074] Formula 1:
100 parts 20-25 mole % vinyl terminated diphenylsiloxane-dimethylsiloxane copolymer (Gelest PDV 2335). 3 ppm platinum complex catalyst 0.35 pph of phenyl siloxane hydride crosslinker (Nusil XL-106) Young's modulus of elasticity=0.0033 psi
[0079] Formula 2:
100 parts 20-25 mole % vinyl terminated diphenylsiloxane-dimethylsiloxane copolymer (Gelest PDV 2335). 3 ppm platinum complex catalyst 0.4 pph of phenyl siloxane hydride crosslinker (Nusil XL-106) Young's modulus of elasticity=0.0086 psi
[0084] Formula 3:
100 parts 20-25 mole % vinyl terminated diphenylsiloxane-dimethylsiloxane copolymer (Gelest PDV 2335). 3 ppm platinum complex catalyst 0.5 pph of phenyl siloxane hydride crosslinker (Nusil XL-106) Young's modulus of elasticity=0.0840 psi
[0089] Formula 4:
100 parts 20-25 mole % vinyl terminated diphenylsiloxane-dimethylsiloxane copolymer (Gelest PDV 2335). 3 ppm platinum complex catalyst 0.6 pph of phenyl siloxane hydride crosslinker (Nusil XL-106) Young's modulus of elasticity=2.6 psi
[0094] The walls 112 , 114 of the lens chamber 110 and the fluid or gel contained within the lens cavity 120 are preferably selected so as to prevent or reduce the likelihood of the fluid or gel migrating outside of the walls 112 , 114 of the lens chamber 110 . Thus, in a preferred embodiment, one or both of the walls 112 , 114 of the lens chamber 110 and the fluid or gel is/are selected from biocompatible materials that optimize the resistance to permeability of the fluid or gel across the walls 112 , 114 of the lens chamber 110 .
[0095] One method of decreasing the permeability of the gel contained inside the cavity 120 across the walls 112 , 114 of the lens chamber 110 is to provide a gel that is cross-linked. The degree of cross-linking, however, must be selected and controlled such that, on the one hand, the walls 112 , 114 of the lens chamber 110 and the gel have a sufficiently low Young's modulus to minimize the resistance of the walls 112 , 114 of the lens chamber 110 to deformation and, on the other hand, to minimize the permeation of the gel across the walls 112 , 114 of the lens chamber 110 . Thus, in a preferred embodiment, longer chain polymers that are lightly cross-linked, such as those used for silicone gels, starting with monomers having molecular weights that are greater than 35,000 daltons, preferably greater than 50,000 daltons and, most preferably, at least 70,000 daltons are desired.
[0096] In another preferred embodiment, a gel is used having low permeability extractables. Such gels may be formulated by using long chain polymers that are branched.
[0097] In a preferred embodiment, one or both of the lens chamber walls 112 , 114 and the gel is made of homo- or co-polymers of phenyl-substituted silicones.
[0098] For the lens chamber walls 112 , 114 , the crosslinked homo- or co-polymers preferably have a diphenyl content of 5-25 mol %, preferably 10-20 mol % and more preferably 15-18 mol %. Alternatively, for the lens chamber walls 112 , 114 , the homo- or co-polymers preferably have a phenyl content of 10-50 mol %, preferably 20-40 mol %, and more preferably 30-36 mol %.
[0099] For the gel, the homo- or co-polymers preferably have a diphenyl content of 10-35 mol %, preferably 15-30 mol % and more preferably 20-25 mol %. Alternatively, for the gel, the homo- or co-polymers preferably have a phenyl content of 20-70 mol %, preferably 30-60 mol % and more preferably 40-50 mol %.
[0100] In a particularly preferred embodiment, the lens chamber walls 112 , 114 are made of a crosslinked phenyl siloxane having a diphenyl content of about 15-18 mol % or a phenyl content of about 30-36 mol % and the gel is made of a phenyl siloxane having a diphenyl content of about 20-25 mol % or a phenyl content of about 40-50 mol %. The lens chamber walls 112 , 114 are understood to be more crosslinked than the gel.
[0101] In a particularly preferred embodiment, the lens chamber walls 112 , 114 are made of a vinyl-terminated phenyl siloxane, most preferably a crosslinked vinyl-terminated phenyl siloxane. Reinforcing agents, such as silica, may also be included in a range 10-70 mol %, preferably 20-60 mol % and most preferably 30-50 mol %.
[0102] The walls 112 , 114 of the lens chamber 110 and the fluid or gel contained within the lens cavity 120 are also preferably selected so as to increase the range of accommodative power that is provided by the lens chamber 110 . In one preferred embodiment, the walls 112 , 114 of the lens chamber 110 are made of a material having a lower refractive index than the fluid or gel contained in the enclosed cavity. In one preferred embodiment, the refractive index of the lens walls 112 , 114 of the chamber 110 is 1.38 and the refractive index of the gel or fluid is 1.49.
[0103] The differential refractive indices provided by the lens chamber walls 112 , 114 and the gel or liquid contained within the chamber 120 may be provided by the differences in the materials or the composition of the materials used for the lens chamber walls 112 , 114 and the gel or liquid.
[0104] In one embodiment, both the lens chamber walls 112 , 114 and the gel or liquid is made of a phenyl siloxane having different diphenyl or phenyl content. In a preferred embodiment, the lens chamber walls 112 , 114 has a diphenyl or phenyl content that is less than that for the gel or liquid. In another preferred embodiment, the walls 112 , 114 of the lens chamber 110 may be made of a cross-linked vinyl-terminated phenyl siloxane having a diphenyl content of 15-18 mol % or a phenyl content of 30-36 mol % and the gel contained within the walls 112 , 114 of the lens chamber 110 may be made of a vinyl-terminated phenyl-siloxane having a diphenyl content of 20-25 mol % or a phenyl content of 30-36 mol %.
[0105] In another embodiment, the differential refractive indices may be provided by providing a dimethyl siloxane for the lens chamber walls 112 , 114 and the gel may be a phenyl siloxane having a high diphenyl or phenyl content. In a preferred embodiment, the diphenyl content is at least 20 mol %, at least 25 mol %, at least 30 mol %, at least 35 mol %, and at least 40 mol %. Alternatively, the phenyl content is at least 40 mol %, at least 50 mol %, at least 60 mol %, at least 70 mol %, and at least 80 mol %.
[0106] In a further embodiment, the differential refractive indices may be provided by a crosslinked fluoro siloxane, such as a 3,3,3-trifluoropropylmethyl siloxane and the gel may be a phenyl siloxane having a high diphenyl or phenyl content. In a preferred embodiment, the diphenyl content is at least 20 mol %, at least 25 mol %, at least 30 mol %, at least 35 mol %, and at least 40 mol %. Alternatively, the phenyl content is at least 40 mol %, at least 50 mol %, at least 60 mol %, at least 70 mol %, and at least 80 mol %.
[0107] Now turning back to FIGS. 1A-1B , a main cavity 130 is defined between the lens chamber 110 , the base lens 150 and the lens periphery 170 . The main cavity 130 is preferably filled with a fluid or gel. The fluid or gel in the main cavity 130 may be the same as the fluid or gel contained in the enclosed cavity 120 . In a preferred embodiment, the fluid is a saline solution and the main cavity 130 is filled with the saline solution after implantation of the IOL in the capsular bag of the eye.
[0108] Filling the main cavity 130 after implantation of the IOL into the capsular bag will permit the IOL to take on a significantly smaller delivery profile such that the IOL may be rolled up and inserted through a relatively small incision. In a preferred embodiment, the incision size is less than 6 mm, preferably less than 5 mm, most preferably less than 4 mm and even most preferably less than 3 mm.
[0109] In embodiments where the main cavity 130 is filled with a fluid or gel after implantation, a valve (not shown) is preferably disposed on the IOL to permit injection of the fluid or gel into the main cavity 130 after implantation. The valve may be a one-way valve that permits injection of fluid or gel into the main cavity 130 but prevents the fluid or gel from exiting the main cavity 130 . The valve is preferably disposed on the surface of the IOL that is facing in the anterior direction after it has been implanted in the eye. It is understood that the valve, however, is preferably not disposed on either one of the opposing sides 112 , 114 so as to avoid disrupting the integrity of the lens chamber 110 which may house the same of different fluid or gel.
[0110] In a preferred embodiment, the fluids or gels in the respective enclosed cavity 120 and the main cavity 130 are completely segregated from one another. In one preferred embodiment, the enclosed cavity 120 and the main cavity 130 may have a different fluid and/or gel. In another preferred embodiment, one of the enclosed cavity 120 and the main cavity 130 may comprise one of a fluid or gel and the other one of the enclosed cavity 120 and the main cavity 130 may comprise the other one of a fluid or gel. In a preferred embodiment, there is no fluid exchanged between the enclosed cavity 120 and the main cavity 130 .
[0111] The IOL 100 is intended to be implanted in a capsular bag 40 of the eye and centered about an optical axis A-A (See FIGS. 11A-11C ). The lens chamber 110 and the base lens 150 are dimensioned to extend to or beyond the effective optical zone B-B as defined about the optical axis A-A of a patient's eye. The effective optical zone B-B is generally the largest possible opening through which light can enter the eye and thus is controlled by the largest effective diameter of the pupil 30 when completely dilated. This diameter is typically about 4-9 mm. Therefore, in a preferred embodiment, the diameters of the lens chamber 110 and the base lens 150 is preferably at least 4 mm, at least 5 mm, at least 6 mm, at least 7 mm, at least 8 mm and at least 9 mm.
[0112] As previously indicated, either one or both of the enclosed cavity 120 of the lens chamber 110 and/or the main cavity 130 is/are filled with a fluid or gel. The fluid may be a gas, a liquid. The fluid or gel preferably is characterized as having a sufficiently high refractive index such that the lens chamber 110 provides a range of accommodation in response to small changes in the curvature of the opposing sides 112 , 114 .
[0113] Because the IOL 100 is resiliently biased such that the opposing sides 112 , 114 of the lens chamber 110 are substantially flat or have minimal curvature, small changes in the curvature of the opposing sides 112 , 114 will lead to proportionately greater changes in the refractive power of the lens. Thus, the lens chamber 110 , in combination with the base lens 150 , can provide a change in the optical power of up to at least 3 diopters, preferably up to at least 5 diopters, preferably up to at least 10 diopters and most preferably up to 15 diopters in response to the accommodative forces (e.g., radially compressive forces) exerted on the implanted IOL.
[0114] FIG. 2 depicts another embodiment of the IOL 200 . The IOL 200 is similar in many respects with the IOL 100 of FIGS. 1A-1B in that it comprises a lens chamber 210 , a base lens 250 and a lens periphery 270 joining the lens chamber 210 and the base lens 250 . The lens periphery 270 further comprises a circumferential edge 280 . The IOL 200 differs from IOL 100 in that IOL 200 comprises a plurality of holes 202 disposed circumferentially along the top surface of the IOL 200 and externally around the lens chamber 210 and a circumferential channel 240 disposed within the lens periphery 270 . The holes 202 are intended to provide a fluid exchange channel between the circumferential channel 240 , the main cavity 230 and the exterior of the IOL 200 . The accommodative forces of the eye's capsular bag will cause the IOL 200 to radially expand and compress which, in turn, will cause the aqueous fluid to enter and exit the main cavity 230 through the holes 202 . In a preferred embodiment, the holes 202 are disposed symmetrically about the top surface of the IOL 200 .
[0115] FIGS. 3A-3B depict another embodiment of the IOL 300 which comprises a plurality of through-holes 302 around the circumferential periphery of the IOL 300 . The through-holes 302 differ from the holes 202 in FIG. 2 in that the through-holes are provided through both sides of the IOL 300 and the IOL 300 does not comprise a circumferential channel, whereas the holes 202 of the IOL 200 of FIG. 2 are only provided on the top surface of the IOL 200 . The provision of through-holes 302 increase the efficiency with which the aqueous fluid fills and exits the main cavity 330 .
[0116] Moreover, the through-holes 302 are dimensioned to be as large as can fit between the space between the circumferential edge 380 and the lens chamber 310 . One advantage in the provision of numerous large through-holes 302 about the circumferential periphery is that it reduces the material bulk of the IOL 300 and permits it to take on a smaller delivery profile when it is folded and inserted into the capsular bag of the eye during implantation surgery. Thus, the IOL 300 will require a smaller incision for implantation into the capsular bag of the eye. It is understood, however, that the spacing 301 between the through-holes 302 must be sufficient to permit the transfer of force applied to the circumferential edge 380 onto the lens chamber 310 . In a preferred embodiment, the spacing 301 is no more than ¼, preferably no more than ½, and most preferably no more than ¾ of the diameter of the through-holes 302 .
[0117] FIG. 4 depicts another embodiment of the IOL 400 also comprising through-holes 402 , except that the through-holes 402 do not provide a fluid exchange between the main cavity 430 and the exterior of the IOL 400 . The IOL 400 is thus similar to the IOL 100 of FIGS. 1A-1B in that a valve is required such that the main cavity 430 of the IOL 400 may be filled after implantation into the capsular bag of the eye. The main function of the through-holes 402 in this embodiment is to reduce the bulk of the IOL 400 so as to provide a smaller delivery profile. Thus, once implanted, the fluid or gel in the lens cavity 420 and the main cavity 430 remain contained and the IOL 400 does not permit for fluid exchange between the fluid in the exterior of the IOL 400 and the fluid or gel in the main cavity 430 . FIG. 4 differs from the IOLs depicted in the preceding figures ( FIGS. 1-3 ) in that it depicts the shape of the IOL 400 when a radial force is applied to the peripheral edge so as to cause a the opposing sides of the cavity 420 to bulge apart from one another. It is noted that the IOL 400 must be dimensioned such that the lower wall of the lens cavity 420 does not contact the base lens 450 within a range of the radial force that would be expected during the accommodation of the eye.
[0118] FIGS. 5A-5B depict yet a further embodiment of the IOL 500 which comprises a plurality of arc-shaped cutouts 502 . The arc-shaped cutouts 502 are configured to function to provide a fluid exchange between the main cavity 530 and the exterior of the IOL 500 . The IOL 500 comprises radial arms 504 between the arc-shaped cutouts 502 to couple and support the base lens 550 to the lens periphery 570 . In a preferred embodiment, the radial arms 504 comprise a hinge between the peripheral portion 570 and the base lens 550 that permits the radial arms 504 to bend or rock inwardly upon application of a force upon the circumferential edge 580 so that the force is transferred to radially compressing the lens chamber 510 . The hinge may simply be a groove or an area of reduced material thickness that is disposed either on the internal, external or both internal and external surfaces of the radial arms 504 . As with the other IOLs described herein, the IOL 500 returns to a radially-expanded state in the absence of a force applied upon the circumferential edge 580 . The IOL 500 is resiliently biased to a flatter configuration as shown in FIG. 5A in the absence of radially-compressive forces being exerted on the circumferential edge 580 , as when the eye is unaccommodated. The IOL 500 is radially compressible to reduce the overall diameter of the lens chamber 110 and thus cause opposing sides 512 , 514 of the lens chamber 510 to increase its curvature upon the application of a radially compressing force onto the circumferential edge 580 , as when the eye is accommodated. See, e.g., FIG. 4 .
[0119] FIGS. 6A-6B depicts yet a further embodiment of the IOL 600 which comprises an internal circumferential channel 640 in addition to the enclosed cavity 620 and the main cavity 630 . The circumferential through-holes 602 permit aqueous fluid flow into and out of the circumferential channel 640 and the arc-shaped cutouts 604 permit aqueous fluid flow into and out of the main cavity 630 . Radial arms 606 couple the base lens 650 to the peripheral portion 670 and a hinge is disposed on the radial arm between the base lens 650 and the peripheral portion 670 . Again, the presence of the internal circumferential channel 640 is intended to reduce the material bulk and thus to permit insertion of the IOL 600 through relatively smaller incisions.
[0120] The IOLs described herein are intended for implantation in a capsular bag of a patient's eye following performance of a capsulorhexis, in which a circular portion is removed from the anterior portion of the capsular bag.
[0121] FIG. 11A depicts the eye 10 following performance of a capsulhorexis and before implantation of an IOL. The eye 10 is depicted as comprising a cornea 20 through which the surgical incision is made to access the capsular bag 40 . The diameter of the circular portion B-B removed from the capsular bag 40 depends upon each person's individual anatomy is typically in the range of from about 4 mm to about 9 mm. Here, the diameter 32 of the circular portion B-B removed from the capsular bag 40 corresponds roughly to the diameter of the pupil 30 . Preferably, as much of the capsular bag 40 and its zonular connections 50 are maintained as possible. The zonules 50 couple the capsular bag 40 with the ciliary muscle 60 and transmit the accommodative forces to effectuate the curvature or shape changes of the capsular bag 40 . Once the crystalline lens material is removed from the capsular bag 40 , the IOL may be inserted and implanted such that the circumferential edge substantially engages the zonules 50 attached to the capsular bag 40 . Additionally, the IOL is substantially centered along the optical axis A-A and engagement of the IOL with the zonules 50 is preferred to reduce the likelihood of decentration. In embodiments of the IOL comprising holes and through-holes, it is preferable that the holes and through-holes be located outside of the optical zone B-B. Moreover, the holes and through-holes should have rounded edges so as to prevent the perception of glare by the recipient.
[0122] FIGS. 7A-7B and 8A-8B depict an IOL 700 which is configured with raised protrusions 790 or troughs 795 adjacent to the through-holes 702 to create a space between the capsular bag and the through-holes 702 and to thereby ensure the free flow of the aqueous fluid in and out of the main cavity 730 and the circumferential channel 740 .
[0123] The IOL 700 comprises three enclosed chambers: an enclosed lens chamber 720 , a main cavity 730 and an internal circumferential channel 740 . A plurality of circumferentially disposed through-holes 702 are sized to provide fluid exchange between both the main cavity 730 and the internal circumferential channel 740 , on the one hand, and the exterior of the IOL 700 , on the other hand. The fluid or gel in the lens chamber 720 remains contained within the lens chamber 720 .
[0124] The IOL 700 further comprises arc-shaped cut-outs 704 and radial arms 706 disposed to couple the base lens 750 to the peripheral portion 770 , in the same manner as depicted in FIGS. 6A-6B . The significant feature of IOL 700 is the presence of raised protrusions 790 ( FIGS. 7A-7B ) or troughs 795 ( FIGS. 8A-8B ) adjacent the through-holes 702 . The raised protrusions 790 or troughs 795 are configured to ensure that the capsular bag does not form a seal over the through-holes 702 so as to impede or prevent the aqueous fluid from flowing freely in and out of the main cavity 730 and the circumferential channel 740 .
[0125] As discussed above, the IOLs described herein are configured to transmit most, if not all, of the radially compressive forces exerted on the circumferential edge onto the lens chamber. In contrast to the elastically deformable lens chamber, the base lens is not configured to deform or change its curvature in response to the radially compressive forces exerted on the circumferential edge. The transfer of the radially compressive forces onto the lens chamber may be accomplished by incorporating one or more of the following features in the IOL: (1) the opposing sides of the lens chamber having a reduced thickness as compared to the base lens, (2) a hinge disposed between the base lens and the peripheral portion, (3) utilizing materials having different elastic moduli for the lens chamber and the base lens; and (4) the variation of refractive indices provided for the opposing sides of the lens chamber and the fluid or gel contained therein.
[0126] FIGS. 10A and 10B depict an IOL 800 which is constructed of at least two different elastomeric materials having different Young's modulus of elasticity, with at least the base lens 850 being made of a material having a higher Young's modulus than the lens chamber 810 .
[0127] FIG. 10A depicts the IOL 800 as being constructed by assembling at least five (5) separately molded pieces, 801 A, 802 A, 803 A, 804 A, and 850 . Thus, in addition to the two halves 801 A, 803 A of the lens chamber 810 , The peripheral portion of the IOL 800 is provided in two ring portions 802 A, 804 A. The first ring portion 802 A surrounding the lens chamber 810 has a higher elastic Young's modulus than the second ring portion 804 A surrounding the base lens 850 . In a preferred embodiment, the two halves 801 A, 803 A of the lens chamber 810 and the second ring portion 803 A has a Young's modulus of 100 psi or less, preferably 75 psi or less, and most preferably 50 psi or less and the base lens 850 and the first ring portion 802 has a Young's modulus of more than 100 psi, preferably more than 250 psi, and most preferably more than 350 psi. In a particularly preferred embodiment, the Young's modulus of the first ring portion 802 A may be up to 500 psi.
[0128] FIG. 10B depicts the IOL 800 as being constructed by assembling at least three (3) separately molded pieces 801 B, 802 B and 803 B. The first lens chamber 810 and the surrounding peripheral portion is provided by assembling 801 B and 802 B and the base lens portion 850 and the surrounding peripheral portion is provided by assembling 803 B to the underside of 802 B. The assembled first lens chamber 810 and surrounding peripheral portion ( 801 B, 802 B) has a lower elastic Young's modulus than the base lens portion 850 and the surrounding peripheral portion ( 803 B). In a preferred embodiment, portions 801 B, 802 B has a Young's modulus of 100 psi or less, preferably 75 psi or less, and most preferably 50 psi or less and the base lens portion 803 B has a Young's modulus of more than 100 psi, preferably more than 250 psi and, most preferably, more than 350 psi. In a particularly preferred embodiment, the Young's modulus of the base lens portion 803 B may be up to 500 psi.
[0129] The invention described and claimed herein is not to be limited in scope by the specific preferred embodiments disclosed herein, as these embodiments are intended as illustrations of several aspects of the invention. Indeed, various modifications of the invention in addition to those shown and described herein will become apparent to those skilled in the art from the foregoing description. Such modifications are also intended to fall within the scope of the appended claims. | An intraocular lens (IOL) device comprising a first lens, a second lens and a circumferential haptic. The first lens comprises a pair of opposing and deformable surfaces and a cavity defined therebetween. The first lens has a first lens diameter. The second lens has a second lens diameter. The circumferential haptic has an outer peripheral edge and couples the first lens and the second lens. A main IOL cavity is defined by the circumferential haptic, the first lens and the second lens. The IOL device is resiliently biased to an unaccommodated state, characterized by the IOL device having a first diameter d 1 in the absence of radial compressive forces exerted on the outer peripheral edge. The IOL device actuates to an accommodated state being characterized by a second diameter d 2 in response to radial compressive forces exerted on the outer peripheral edge, wherein d 1 >d 2 . | big_patent |
PRIOR APPLICATION
This application is a continuation-in-part of my prior copending application Ser. No. 07/589,995filed Sep. 28, 1990 entitled ESOPHAGEAL DISPLACEMENT ELECTRODE. That application is incorporated by reference herein.
FIELD OF THE INVENTION
This invention relates to esophageal electrodes and, more particularly, comprises such an electrode that may be inserted down a patient's esophagus and into the stomach with a portion of the electrode in contact with the stomach wall in a position most favorable for electrically stimulating the ventricle of the heart in cooperation with an external electrode placed on the patient's chest.
There are a number of medical procedures in which esophageal electrodes are used for such purposes as defibrillating and pacing the heart as well as for stimulating breathing. Examples of the use of esophageal electrodes in such procedures are shown in several United States patents and pending applications including Nos. 4,574,807, 4,683,890, 4,735,206, and 4,960,133; and Ser. Nos. 421,807 filed Oct. 16, 1989; 214,778 filed Jul. 5, 1988; and 812,015 filed Dec. 23, 1985 (now abandoned). An esophageal electrode may also be used as an ECG pickup. Those patents and applications are herein incorporated by reference. Many of these procedures may be substantially enhanced and facilitated if the electrode is capable of being moved close to the organ of the body being treated such as the ventricles of the heart.
Frequently patient care in a hospital and emergency care outside a hospital require ventricular pacing. Customarily, this is an invasive procedure and must therefore be performed in a sterile atmosphere, and the procedure requires a considerable period of time to perform. Many of the patents and applications identified above disclose a method and apparatus employing an internal, noninvasive esophageal electrode in combination with an external chest electrode, which are much more convenient to use, more efficient in performing the intended function, and do not require the presence of a physician.
The techniques described in the above identified patents and applications relating to pacing and/or defibrillation may be made more efficient if the electrode is positioned as close to the ventricle of the heart as possible. The closer the electrode is to the ventricle, the less electrical energy is needed to perform the pacing or defibrillating functions, and the more confident the attendant may be that the current flow between the internal and external electrodes is along the desired path.
The prior application Ser. No. 07/589,995, supra is directed to an esophageal displacement electrode to achieve greater efficiency in the practice of such procedures. The device includes a semi rigid plastic tube that may be inserted either orally or nasally into the esophagus. The tube carries an electrode at its distal end and has a mechanism incorporated into it which enables the user to cause the distal end of the tube to bend and press against the wall of the esophagus. The mechanism is of sufficient strength to cause the esophagus to displace under the pushing force of the electrode. To enable the tube to bend readily under the action of the mechanism, the tube is crimped so as to define a hinge at the distal region of the tube. The mechanism for deflecting the distal end of the tube includes a rigid pin having a cord connected at each end and which is aligned generally parallel to the axis of the tube and positioned at the distal portion thereof in the vicinity of the hinge. One cord attached to the proximal end of the pin extends out the proximal end of the tube, while the other cord attached to the distal end of the pin extends through a port located distally of the hinge in the tube and reenters the tube through a second port proximal of the hinge and then extends out the proximal end of the tube. By pulling on the cord attached to the distal end of the pin, the pin may be positioned beyond the hinge adjacent the distal port, and continued pulling of the cord will cause the tube t bend at the hinge.
The present invention is directed to an esophageal-stomach electrode to achieve greater efficiency in the performance of such procedures. The closer an electrode is positioned to the heart, the less electrical power is needed to control the heart and more consistent control of the heart is achieved. In accordance with the present invention a thin semi rigid plastic tube with the electrode on the distal end similar to the tube in the 07/589,995 application is used, but of sufficient length to be passed down the esophagus into the stomach. A mechanism, also similar to that in the earlier application, is incorporated into the tube which enables the user to cause the last couple of inches of the distal end of the tube to bend back on itself approximately 135 degrees from its original position. The user then withdraws the electrode until the bent back section of the distal end impacts on the stomach wall and displaces the stomach wall toward the heart. This action places the electrode in its operative position closest to the ventricle of the heart so as to cooperate with an external electrode on the chest to impress a pulse upon the heart. The bent back section of the distal end also prohibits further withdrawal of the electrode.
This invention will be better understood and appreciated from the following detailed description of a preferred embodiment thereof, selected for purposes of illustration and shown in the accompanying drawings.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a diagrammatic frontview of a patient suggesting the heart, esophagus and stomach and showing without details of esophageal-stomach displacement electrode of the present invention extending through the esophagus and into the stomach;
FIG. 2 is an enlarged cross-sectional view of the distal end of displacement electrode disposed in the stomach and with the distal end in the undisplaced position;
FIG. 3 is a view similar to FIG. 2 but showing the distal end of the electrode in its displaced position;
FIG. 4 is a view similar to FIG. 3 and showing the electrode elevated so that its tip engages the wall of the stomach and displaces the wall so that it essentially engages the heart;
FIG. 5 is a side view of the control mechanism for the electrode shown in FIGS. 1 4 and showing one of the positions for the control slide; and
FIG. 6 is a cross-sectional view of the control mechanism taken along section line 6 6 in FIG. 5.
DETAILED DESCRIPTION OF THE INVENTION
In FIG. 1 the torso and head of a patient are shown along with the patient's heart H, esophagus E and stomach S. The stomach is located posterior and spaced from the ventricle V. The esophageal-stomach displacement electrode shown extends through the patient's mouth, through the esophagus and into the stomach with its distal end located relatively close to the ventricle V. The present invention enables the distal end of the esophageal-stomach displacement electrode to displace angularly within the stomach and subsequently be pulled slightly back out of the esophagus, or alternatively, further angularly displaced, upwardly into pressurized contact with the stomach wall to position the wall closer than normal to the heart (see FIG. 4) and thereby place the stomach displacement electrode in closer proximity to it. This is illustrated in FIGS. 2, and 3 and 4.
The electrode includes a semi rigid plastic tube 10 made of nylon or other suitable material which may be approximately 20 inches long and approximately 3/16 inch in diameter. The tube should be semi rigid, much like a gastric tube, and be relatively torque free. The distal end 12 of the tube carries an electrode 14, preferably spherical in shape and having a stem 16 that fits within the distal end of the tube. The electrode may be pressed in place or suitably fastened by other means. In the preferred form, the electrode 14 is 1/4 inch in diameter, which just exceeds the diameter of the tube 10 so that the ball will make positive contact with the stomach wall when the distal end 12 of the tube 10 is displaced. The distal end 12 may be then further displaced or the complete electrode pulled back out of the esophagus to cause a bulge 50 (FIG. 4) in the stomach wall to place the wall and the electrode 14 closer to heart ventricle V. At this point, the electrode is prevented from further displacement by resistance of the stomach wall.
The tube 10 is carried by a control mechanism 20 shown in FIG. 4 which is connected to a displacement mechanism 22 disposed in the tube. The control mechanism is located at the proximal end of the tube outside the mouth when the esophageal-stomach displacement electrode is placed in the stomach as shown in FIG. 1.
The tube 10 is crimped as suggested at 26 in FIGS. 2, 3 and 4 so as to form a hinge 27 in the tube, which enables it to bend readily at that point. In the wall 25 of the tube 10, ports 28 and 30 are formed on opposite sides of the hinge 27, each spaced approximately an inch therefrom. While in the embodiment shown, each of the two ports is approximately one inch from the crimp 26, that dimension as well as others given may be varied to suit the particular application, as is more fully described below.
A rigid pin 32 is disposed in the tube 10 and extends generally parallel to the tube axis. The pin may be made of metal, rigid plastic, or any other material having sufficient rigidity to prevent the tube 10 from bending at the crimped area 26 when the pin spans the hinge.
A pair of cords 34 and 36 are connected to the proximal and distal ends 38 and 40, respectively, of pin 32 and extend proximally in the tube 10 out its proximal end 42 and into the control mechanism 20. Cord 34 extends directly from the proximal end of the pin 32 within the tube 10 to the control mechanism 20, while cord 36 extends from the distal end 40 of the pin, out the tube 10 through port 28 and from that point it extends proximally externally of the tube, spanning the crimped portion 26 to the port 30 where the cord reenters the tube 10 and extends in the tube to the control mechanism 20. As is evident from FIGS. 2, 3 and 4, the location of the pin 32 may readily be changed by pulling one or the other of the cords 34 or 36 in a proximal direction.
Pin 32 is somewhat shorter than the distance between the crimped portion 26 of the tube and the lower port 28. Travel of the pin 32 in the tube 10 in a distal direction is limited by the location of port 28. The size of pin 32 is such that it cannot be drawn through port 28 and, therefore, when the pin 32 reaches its lowermost point and a continued pull is exerted on cord 36, the distal portion of the tube 10 is caused to deflect (in this example approximately 135°) from the position shown in FIG. 2 to that shown in FIG. 3. At this point the tube must still be further deflected or pulled back out of the stomach to place it into pressurized contact with the stomach wall to cause a bulge 50 as shown in FIG. 4. While the tube 10 is displaced or bent about the hinge 27 by pulling on cord 36 when pin 32 has reached its lowermost position, merely by releasing tension on the cord 36, the natural bias of the tube 10 to the configuration of FIGS. 1 and 2 will cause it to return to the shape shown therein.
The control mechanism 20 shown in FIG. 5 is connected to the distal ends of the cords 34 and 36 to operate the displacement mechanism 22 by taking up one cord and playing out the other. The control mechanism 20 includes a sleeve 50, rectangular in cross section in the embodiment shown, and containing a slide 52. A bracket 54 is secured to the bottom wall 56 of sleeve 50 and retains the proximal end 42 of tube 10 in place. The bracket 54 includes a bar 62 and clamping plate 58 that sandwich the tube end, and the plate 58 is secured to the bar 62 by screws 60.
The cords 34 and 36 enter the sleeve 50 through a port 64 in bottom wall 56, aligned with the proximal end 42 of the tube 10 when the tube is secured to the bracket 54. The proximal ends 66 and 68 of the cords are respectively connected to flanges 70 and 72 carried by the slide 52. In FIG. 5, slide 52 is shown in the position that places the pin 32 in the tube in the position shown in FIG. 2. When the slide is moved to the right as viewed in FIG. 5, the pin 32 moves to its lowermost position in tube 10 and the tube is deflected, as shown in FIG. 3. Because the slide 52 is generally U shaped with an opening 74 in its bottom wall 76 that rests upon the bottom wall 56 of sleeve 50, movement of the slide 52 in the sleeve 50 does not in any way interfere with the movement of the cords 34 and 36 in response to displacement of the slide.
The electrode typically may be used in the following manner. Assume that the electrode is part of a pacing mechanism as shown in U.S. Pat. No. 4,735,206, supra. The tube 10 is inserted into the esophagus either through the mouth or the nasal passage to a depth wherein the electrode 14 is disposed out the lower end of the esophagus into the stomach at a depth sufficient to enable displacement of the tube's distal end 12 to approximately 135 degrees from its straighten or insertion position as shown in FIG. 3. The external electrode also forming part of the pacer is mounted on the chest of the patient and the controls, etc. are properly set. In order to reduce the amount of electrical energy required to effect pacing, the operator moves the slide 52 to the right as shown in FIG. 5 which will cause the pin 32 to move downwardly in the tube 10 so that its distal end 40 is immediately adjacent the port 28. Further movement of the slide 52 in that direction will cause the distal portion of the tube 10 to deflect and place the electrode 14 in proximity to the upper stomach wall near the heart ventricle V., as shown in FIG. 3. Further deflecting the distal end 12 or pulling back the tube 10 at its proximal portion then places the electrode 14 in pressurized displacable contact with the upper stomach wall causing a bulge that places the electrode closer to the ventricle V (FIG. 4). With the electrode in the displaced position of FIG. 4, the pacing pulses are imposed across the electrodes. When the procedure is completed, the operator may move the slide 52 back to the position of FIG. 5, which will relieve the tension on the cord 36 and allow the tube 10 to return to the position of FIG. 2. Thereafter the tube 10 may be withdrawn.
From the foregoing description, those skilled in the art will appreciate that the present invention provides a very convenient means of enabling an operator to place the esophageal stomach displacement electrode very close to the heart or other organ by means of a noninvasive procedure and thereby reduce the energy required to carry out the particular procedure such as pacing or defibrillation upon the patient. It will also be appreciated that while a specific embodiment is shown in the drawings, modifications may be made thereof without departing from this invention. For example, while a pin is shown as applying the bending force to the interior of the tube, other configurations for the device may be employed. Any structure which will not pass through the lower port 28 and will not interfere with the action of the hinge 27 will cause the tube 10 to deflect when the cord attached to it and exiting the tube through the port 28 is tensioned. It should, if necessary, also stiffen the hinge portion of the tube when it is being inserted in the esophagus and stomach. The member which applies the bending force must be capable of moving freely in the tube under the operation of the control 20 so as to be readily movable in response to actuation of the control. The tube 10 could, of course, carry more than one electrode. For example, in the earlier patents, supra, a number of spaced contact rings are shown carried by the tube.
Because modifications may be made of the invention without departing from its spirit, it is not intended that the scope of this invention be limited to the specific embodiment illustrated and described. Rather, the scope of this invention is to be determined by the appended claims and their equivalents. | An esophageal-stomach displacement electrode comprises a flexible tubular member designed to be inserted through the esophagus into the stomach. An electrode is carried by the tube in the region of its distal end. The tube is hinged near the distal end which enables that end of the tube to displace angularly in the stomach and displace the stomach wall. The stomach wall displacement may occur by angularly displacing the distal end or by otherwise pulling the tube partially out of the esophagus after its distal end partially displaced toward the stomach wall. A displacement mechanism is disposed in the tube in the region of the hinge and is controlled from a point externally of the body for causing the distal end of the tube to displace angularly, and to be positioned to engage and displace the stomach. | big_patent |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to games and, more specifically, to a board game having a lake theme.
[0003] 2. Description of the Related Art
[0004] A wide variety of games have a common characteristic, namely, competition among two or more players using a single set of rules. Some of these games, specifically board games, involve movement of pieces upon a board onto, in, over or though spaces that relate to each player's status and/or position.
[0005] Many proposed board games have attempted to simulate the accumulation of wealth through a variety of mechanisms. For example, U.S. Pat. No. 2,026,082 to Darrow discloses a game simulating the world of real estate in which players move game pieces around a board and attempt to accumulate wealth and property at the expense of opposing players. Moreover, U.S. Pat. No. 4,140,319 discloses a game simulating the development and rezoning of real estate and accumulation of wealth involving game pieces moveable upon a board. Additionally, U.S. Pat. No. 4,189,153 simulates the accumulation and development of businesses and their employees.
[0006] Several others have proposed particular designs for playing boards and/or game pieces used in games, including U.S. Design Pat. No. 262,125 (“POT LUCK” game board), U.S. Pat. No. 295,987 (“BLACK GOLD” game board), U.S. Pat. No. 340,266 (chessmen), U.S. Pat. No. 352,332 (game pieces), U.S. Pat. No. 380,781 (“ASTRONOPOLY” game board), and U.S. Pat. No. 386,798 (“UNITED STATES POSTAL MONOPOLY GAME”), and U.S. Pat. No. 5,484,157 (chess-like game with military objects as game pieces) and U.S. Pat. No. 5,492,332 (chess-like game with irregularly shaped board).
[0007] Still others have proposed board games with various goals and/or themes, such as U.S. Pat. No. 4,010,957 (purchasing sports teams), U.S. Pat. No. 4,052,071 (accumulating wealth and travel across the U.S.), U.S. Pat. No. 4,062,544 (raising self “out of ghetto”), U.S. Pat. No. 4,136,881 (accumulating wealth according to two economic paradigms), U.S. Pat. No. 4,378,942 (accumulating stocks, commodities or bonds), U.S. Pat. No. 4,486,022 (buy, sell and trade sports performers), U.S. Pat. No. 4,927,156 (accumulating speculatively priced properties), U.S. Pat. No. 5,135,230 (accumulating income and maximizing baseball player quality), U.S. Pat. No. 5,292,133 (acquiring African nations), U.S. Pat. No. 5,314,188 (attempting to get family members home), and U.S. Pat. No. 5,456,473 (completing construction project), U.S. Pat. No. 5,673,915 (purchasing U.S. states, highways, airports and telephone companies), and U.S. Pat. No. 6,164,650 (“add-on” game for use with MONOPOLY™ game).
[0008] Other proposals for board games have been disclosed in British Patent Specification 694,880 (get to a home space across irregularly routed path of spaces), British Patent Specification 915,550 (experiencing foreign travel), and UK Application GB 2 055 299 A (playing board with holes for score markers).
[0009] Although the above proposals have no doubt supplied much entertainment, none of the above games, boards and/or game pieces have successfully simulated the ups and downs of life at a lake. Moreover, none of the above inventions and patents, taken either singularly or in combination, is seen to describe the instant invention as claimed. Thus a board game having a lake theme solving the aforementioned problems is desired.
SUMMARY OF THE INVENTION
[0010] The invention is a game having a lake theme. A game includes: a playing board; a plurality of tokens representing identities of players playing the game; a plurality of title deed cards; a plurality of game pieces; a source of scrip; a plurality of cards each one of which bears indicia related to one of a penalty, an award and a direction; and at least two elements operable by the players in turn for randomly determining movement of the tokens upon the board.
[0011] The playing board includes a plurality of successive, contiguous spaces defining a continuous path about a periphery of the board. First, second and third sets of the spaces identify properties, such as lake areas, dams and boat dealerships, that may be purchased with scrip by a player landing upon the respective space. Each one of the title deeds is associated with a respective one of the lake areas, dams and boat dealerships, and bears indicia indicating a rental payment payable to a player acquiring the property, and payable by a player subsequently landing upon the space identifying the property. Each of the game pieces may be purchased with scrip and placed upon an acquired lake area, dam or boat in order to increase the rental payment. Preferably, a plurality of the deeds bear indicia relating to lakes. Preferably, a plurality of the spaces bear indicia related to lakes. Preferably, a plurality of the cards bear indicia related to lakes.
[0012] Accordingly, it is a principal object of the invention to provide a board game simulating the ups and downs of life at a lake.
[0013] It is another object of the invention to provide a board game where by the ups and downs of life at a lake may be simulated by acquiring lake properties, dams and boat dealerships.
[0014] It is a further object of the invention is to provide a board game whereby the ups and downs of life may be simulated by erection of game pieces on spaces identifying the lake areas, dams and boat dealerships.
[0015] It is an object of the invention to provide improved elements and arrangements thereof for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes.
[0016] These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] [0017]FIG. 1A is a plan view of a game board having a lake theme according to the present invention.
[0018] [0018]FIG. 1B is a plan view of portion B of the game board of FIG. 1A.
[0019] [0019]FIG. 1C is a plan view of portion C of the game board of FIG. 1A.
[0020] [0020]FIG. 1D is a plan view of portion D of the game board of FIG. 1A.
[0021] [0021]FIG. 1D is a plan view of portion D of the game board of FIG. 1A.
[0022] [0022]FIG. 1F is a plan view of portion F of the game board of FIG. 1A.
[0023] [0023]FIG. 1E is a plan view of portion E of the game board of FIG. 1A
[0024] [0024]FIG. 1G is a plan view of portion G of the game board of FIG. 1A.
[0025] [0025]FIG. 1H is a plan view of portion H of the game board of FIG. 1A.
[0026] [0026]FIG. 1I is a plan view of portion I of the game board of FIG. 1A.
[0027] [0027]FIG. 2A is a profile view of a game piece resembling a boat propellar.
[0028] [0028]FIG. 2B is a profile view of a game piece resembling an anchor.
[0029] [0029]FIG. 2C is a profile view of a game piece resembling a speedboat.
[0030] [0030]FIG. 2D is a plan view of a game piece resembling a Lake Cabin.
[0031] [0031]FIG. 2E is a plan view of a game piece resembling a Marina building.
[0032] [0032]FIGS. 3A, 3B, 3 C, 3 D, 3 E, 3 F, 3 G, 3 H and 3 I are plan views of a plurality of individual Makin a Wake and Sunken Chest cards.
[0033] [0033]FIG. 4A is a plan view of title deed cards to the Bear Lake and Jump Off Joe Lake properties.
[0034] [0034]FIG. 4B is a plan view of title deed cards to the Sun Runner Boat Dealership and Medical Lake properties.
[0035] [0035]FIG. 4C is a plan view of title deed cards to the Clear Lake and Waitts Lake properties.
[0036] [0036]FIG. 4D is a plan view of title deed cards to the Liberty Lake and Spokane Falls Dam properties.
[0037] [0037]FIG. 4E is a plan view of title deed cards to the Marshal Lake and Rock Lake properties.
[0038] [0038]FIG. 4F is a plan view of title deed cards to the SeaRay Boat Dealership and Deer Lake properties.
[0039] [0039]FIG. 4G is a plan view of title deed cards to the Silver Lake and Loon Lake properties.
[0040] [0040]FIG. 4H is a plan view of title deed cards to the Badger Lake and Sprague Lake properties.
[0041] [0041]FIG. 4I is a plan view of title deed cards to the Thomson Lake and Bayliner Boat Dealership properties.
[0042] [0042]FIG. 4J is a plan view of title deed cards to the Lake Cocolala and Spirit Lake properties.
[0043] [0043]FIG. 4K is a plan view of title deed cards to the Grand Coulee Dam and Long Lake properties.
[0044] [0044]FIG. 4L is a plan view of title deed cards to the Lake Sachine and Priest Lake properties.
[0045] [0045]FIG. 4M is a plan view of title deed cards to the Lake Roosevelt and Donzi Boat Dealership properties.
[0046] [0046]FIG. 4N is a plan view of title deed cards to the Lake Pend Oreille and Lake Couer D'Alene properties.
[0047] Similar reference characters denote corresponding features consistently throughout the attached drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0048] The present invention is a board game intended to simulate the life at a lake. Much of the interest in the game lies in experiencing the ups and downs of life on, at, adjacent, or near a lake, and includes the acts of acquiring, selling, mortgaging and improving properties, such as lake areas, dams and boat Dealerships associated with lakes. While the preferred embodiment set forth below involves particular properties, such as lake areas, boat dealerships on, adjacent, or relating to various lakes, those skilled in the art will understand that the invention is not limited to only lake areas, boat dealerships and dams. Other types of lake-related properties are within the scope of the invention.
[0049] As best illustrated in FIG. 1A, the game includes a generally square-shaped game board 10 including a total of eight portions B, C, D, E, F, G, H, I positioned about a periphery of the board. Each of the portions B, C, D, E, F, G, H, I includes five delineated, sequential spaces. As seen in FIG. 1A, each of portions B, C, D, E, F, G, H, I are contiguous with two other portions B, C, D, E, F, G, H, I, thus forming a continuous path of delineated spaces adjacent a periphery of board 10 .
[0050] As best illustrated in FIGS. 2A through 2C, tokens 20 represent the identities of the players. Tokens 20 are moved across the path according to a throw of dice by the token's owner. For example, if a total of seven results from the owner's dice throw, that player moves his or her token seven spaces along the path. While only three exemplary tokens 20 are depicted, those skilled in the art will appreciate that the invention is not limited to such examples. Other examples of configurations include those in the shape of a captain's wheel, a life preserver, a boat trailer, a cigarette boat, a cabin cruiser, a drag boat, a cruise liner, a jet ski, a ski boat, a fishing boat, an open bow boat, a day cruiser, and a sailboat. Moreover, the number of players is not limited to three. While any reasonable number of players may play, a preferred number of players is four to nine.
[0051] Portion B includes a GO space 100 , which serves as a starting point for the players on the board's continuous path. Portion B further includes two spaces corresponding to lake areas, namely Bear Lake 110 and Jump Off Joe Lake 130 . Sunken Chest space 120 , and Waterfront Taxes Due space 140 make up the remainder of portion B.
[0052] Lake areas in the game are organized into groups. Each of the lake areas in a given group has a common color that identifies their association as a group. For example, a purple bar on each of Bear Lake 110 and Jump Off Joe Lake 130 may be used to identify them as belonging to one group of lake areas.
[0053] Portion C includes three lake areas, namely, Medical Lake 160 , Clear Lake 180 , and Waitts Lake 190 . A bluish-green bar may be used to identify these areas as making up another associated group of lake areas. Portion C further includes Sun Runner Boat Dealership space 160 and Makin A Wake space 170 .
[0054] Portion D includes an IN JAIL/JUST VISITING space 200 , which has a IN JAIL portion 204 and a JUST VISITING portion 205 . Portion D also includes three spaces corresponding to another group of associated lake areas, namely, Liberty Lake 210 , Marshal Lake 230 , and Rock Lake 240 . Orangish-red bars are preferably included on lake areas 210 , 230 , 240 to indicate their association. Spokane Falls Dam space 220 completes the amount of spaces in portion D.
[0055] Portion E includes three spaces corresponding to yet another group of associated lake areas, namely, Deer Lake 260 , Silver Lake 280 and Loon Lake 290 . Bars colored orange may be used to indicate their association as a group. Searay Dealership space 250 and Sunken Chest space 270 complete the number of spaces in portion D.
[0056] Portion F includes a FREE BOAT LAUNCH space 300 and three spaces corresponding to yet another group of associated lake areas, Badger Lake 310 , Sprague Lake 330 , and Thomson Lake 340 , each of which preferably has a red bar thereon to indicate their group association. Makin A Wake space 320 completes portion F.
[0057] Portion G includes three spaces to form yet another group of associated lake areas, namely, Lake Cocolala 360 , Spirit Lake 370 , and Long Lake 390 . They preferably have yellow bars indicating their association. A Bayliner space 350 and a Grand Coulee Dam space 380 complete portion G.
[0058] Portion H includes GO TO JAIL space 400 . Lake Sachine 410 , Priest Lake 420 , Lake Roosevelt 440 make up still another group of associated lake areas. They preferably have colored bars, in this case green, to indicate their association. Sunken Chest space 430 completes portion H.
[0059] Finally, portion I includes two spaces corresponding to a last group of associated lake areas, namely, Lake Pend Oreille 470 and Lake Couer D'Alene 490 . An association between them as a group is preferably indicated by dark blue bars thereon. Portion I is completed by Donzi Dealership space 450 , Makin A Wake space 460 and Boat Tab Renewal space 480 .
[0060] The game is played with scrip money, preferably in denominations of $1, $5, $10, $20, $50, $100, and $500. At the beginning of the game, the players should be given equal amounts of scrip, which in a preferred embodiment of the game is $1,500. If the number of players exceeds the amount of preferred $1,500 multiples of scrip in the bank, then each share of scrip may be accordingly decreased and a credit against the decreased amount be maintained for the player against the Bank.
[0061] The game also utilizes a plurality of Makin A Wake cards 500 , 505 , 510 , 515 , 520 , 525 , 530 , 535 , 540 , 545 , 550 , 555 , 560 , 565 , 570 , 575 , as individually shown in FIGS. 3A through 3D, that are stacked face down and piled at space 30 , as illustrated in FIG. 1A. Similarly, a plurality of Sunken Chest cards 600 , 605 , 610 , 615 , 620 , 625 , 630 , 635 , 640 , 645 , 650 , 655 , 660 , 665 , 670 , 675 , individually illustrated in FIGS. 3E through 3I, are stacked face down and piled at space 40 , again as shown in FIG. 1A. The game also includes a predetermined amount of lake cabins 50 and marinas 60 , as shown in FIGS. 2D and 2E, respectively, for placement upon lake areas.
[0062] The game may be played by two or more players, one of whom serves as Banker. The Banker handles all receipt and payment of scrip on behalf of the Bank. The Bank is the original owner of all of the lake areas, boat dealerships, and dams, as described above.
[0063] Play of the game is organized into turns for each player. On each player's turn, he or she operates one or more elements for randomly determining movement of the tokens over the path. Preferably, two such elements are dice. Based upon the amount shown on the element(s), such as dice, the player moves his or her token the indicated number of spaces along the continuous path in a clockwise direction. Those skilled in the art will appreciate that the invention is not limited to the use of dice, but that any chance-determining element may be used. For example, a spinner may be used to determine the number of spaces advanced by a player's token during his or her turn.
[0064] If, as a result of a player's throw of the dice, his or her token lands upon one of the lake areas, boat dealerships, or dams, he or she may purchase it from the Bank if it is not already owned. The price for the lake area, boat dealership or dam in question is preferably displayed on the associated space. Exemplary prices for the lake areas may be found in Table I, while exemplary prices for each of boat dealerships and dams may be found in Table II. As seen in Tables I and II, prices for the lake areas vary greatly, just as they do around lakes in reality.
TABLE I Preferred Prices for Lake Areas LAKE AREA PRICE ($) Bear Lake 110 60 Jump Off Joe Lake 130 60 Medical Lake 160 100 Clear Lake 180 100 Waitts Lake 190 120 Liberty Lake 210 140 Marshal Lake 230 140 Rock Lake 240 160 Deer Lake 260 180 Silver Lake 280 180 Loon Lake 290 200 Badger Lake 310 220 Sprague Lake 330 220 Thomson Lake 340 240 Lake Cocolala 360 260 Spirit Lake 370 260 Long Lake 390 280 Lake Sachine 410 300 Priest Lake 420 300 Lake Roosevelt 440 320 Lake Pend Oreille 470 350 Lake Couer D'Alene 490 400
[0065] [0065] TABLE II Preferred Prices for Boat Dealerships and Dams BOAT DEALERSHIP OR DAM PRICE ($) Sun Runner Dealership, 150 200 Spokane Falls Dam, 220 150 Searay Dealership, 250 200 Bayliner Dealership, 350 200 Grand Coulee Dam, 380 150 Donzi Dealership, 450 200
[0066] As best shown in FIGS. 4A through 4N, one title deed card 113 , 133 , 163 , 183 , 193 , 213 , 233 , 243 , 263 , 283 , 293 , 313 , 333 , 343 , 363 , 373 , 393 , 413 , 423 , 443 , 473 , 493 is associated with each one lake area. Similarly, a title deed card 153 , 253 , 353 , 453 , 223 , 383 , is associated with each individual boat dealership 150 , 250 , 350 , 450 and each individual dam 220 , 380 , respectively. After payment of scrip money to the Bank, the player purchasing a property receives the associated title deed card as proof of ownership. Preferably, each of the title deed cards associated with a lake area has a colored bar displayed thereon to match the corresponding lake area on board 10 . If the player landing upon an unowned property does not wish to purchase it, the Banker, upon preagreed rules, may auction off the property to the highest bidder among the remaining players. The winning bidder receives the associated title deed card after receipt of payment to the Bank. Once a property has been sold, the associated title deed card is displayed face side up by that player in order to indicate that it is not mortgaged.
[0067] Preferably, each of the boat dealership spaces 150 , 250 , 350 , 450 , and title deed cards 153 , 253 , 353 , 453 associated therewith includes a picture 154 , 254 , 354 , 454 , respectively, that is illustrative of life at a lake. For example, each of pictures 154 , 254 , 354 , 454 can be an ornamental design for a boat, such as one commonly used on a lake. Similarly, each of the dam spaces 220 , 380 , and title deed cards 223 , 383 , includes a picture 224 , 384 illustrative of life at a lake. For example, each of pictures 224 , 384 can be an ornamental design of a waterfall plunging over a dam at the edge of a lake.
[0068] If the property landed upon is already owned by another player, the player landing, or “trespassing”, upon the property must pay a rental fee to the owner if the owner demands the same in a timely manner such as, for example, before the next player rolls the dice. In the case of boat dealerships or dams, the rental fee will depend upon how many boat dealerships or dams are owned by the owner of the landed upon space at the time of the trespass. If the player's token is trespassing upon a dam space, the player must throw the dice and pay a multiple of the dice throw in scrip to the owner of the dam as a rental payment. The multiple used depends upon how many dams are owned by the player owning the dam in question, and is indicated on the title deed to the dam. For example, in a preferred embodiment the player whose token lands upon a dam must pay four times the amount resulting from the dice throw if only one dam is owned, and ten times the amount if two Dams are owned.
[0069] Similarly, if a player's token lands upon a boat dealership that is owned by another player, the player trespassing must also pay the owner a rental fee based upon the number of boat dealerships owned by the player whose boat dealership was landed upon. However, the rental fee is not dependent upon a throw of the dice, but is instead displayed on the associated title deed card. In a preferred embodiment, the trespasser must pay $25 if the owner owns only a single boat dealership, $50 if the owner owns two dealerships, $100 if the owner owns three dealerships and $200 if the other player owns all the dealerships.
[0070] If a player's token lands upon a lake area that is already owned by another player, the rental fee due will depend upon whether all the lake areas in the group are commonly owned and whether the lake area landed upon has been improved, i.e., whether lake cabin(s) and/or a marina have been erected upon the lake area landed upon. The particular rental fee may be read from the information displayed on the associated title deed card. If one player owns all the lake areas in a given group, the rental payment is twice the amount displayed on the associated title deed card if the lake area is not improved, i.e., no lake cabins or marinas have been erected thereon. For example, the rental payment for trespassing upon the Thomson Lake area 340 (and the other lake areas 310 , 330 in the group are not commonly owned) in an unimproved condition is only $20, as best shown in FIG. 4I. The rental payment for trespassing on an unimproved Thomson Lake Area 340 increases to $40 if the owner also happens to own both the other lake areas 310 , 330 associated therewith. The rent for trespassing increases with the number of lake cabins and marinas built upon the trespassed upon lake area. For example, with reference to FIG. 4I, rent for one lake cabin on the Thomson Lake area 340 costs $100, rent for three lake cabins costs $750, and rent for one marina costs $1,100.
[0071] As described above, the Lake Areas are organized into groups. If a player acquires all the Lake Areas within an associated group, the player is allowed to improve one or more of his or her lake areas in the associated group on his or her turn by erecting lake cabins and/or marinas. The player may erect up to four lake cabins on each lake area in the group. Once four lake cabins have been erected on each lake area in the group, the player may then erect up to one marina each on one or more of the lake areas in the associated group. When a marina is erected, the lake cabins must be returned to the Bank. Thus, the rental payment for trespassing on a lake area with a marina does not include any additional rent for the four lake cabins previously, i.e., the rental payment is not cumulative for all improvements.
[0072] The costs for erecting lake cabins and marinas is displayed on the title deed card associated with the lake area that is being improved. For example, with reference to FIG. 4I, the erection of each lake cabin on Lake Thomson 340 costs $150, while the marina costs an additional $150. As in purchases of lake areas from the Bank, the costs for improving a lake area are payable to the Bank. Because the number of lake cabins and marinas is limited, they may not be available from the Bank at the time a player wishes to buy them. If so, that player must wait until another player sells or returns one or more of them back to the Bank, a subject that is described in greater detail below.
[0073] A player improving his or her lake areas in an associated group must do so in an even manner upon the lake areas within that group. For example, while a player may erect one house at a time upon any one of the lake areas in an associated group, he or she may not erect, for example, two houses on one lake area and no houses on another lake area within the same group, or for example, three houses on one lake area and one or no houses on another lake area within the same group.
[0074] The board includes several other lake-related spaces, spaces which do not have corresponding title deed cards and which may not be owned. These spaces include Waterfront Taxes Due space 140 , IN JAIL/JUST VISITING space 200 , FREE BOAT LAUNCH 300 , Boat Tab Renewal space 480 , and GO space 100 . Waterfront Taxes Due space 140 represents the relatively higher amount of taxes paid by a person owning a lot adjacent a lake shore. If a player's token lands upon Waterfront Taxes Due space 140 , that player must pay the Bank his or her choice of 10% of his or her scrip on hand, or $200. Boat Tab Renewal space 480 represents a boat owner's requirement to renew his or her boat trailer's registration, a process evidenced by a new tab. If a player's token lands upon Boat Tab Renewal space 480 , that player must pay the Bank $75 in scrip. Preferably, Waterfront Taxes Due space 140 includes a picture 144 illustrative of home on a lakefront that is subject to, of course, waterfront taxes. Desirably, Boat Tab Renewal space 480 includes a picture 484 illustrative of a boat trailer and money. FREE BOAT LAUNCH 300 space represents a boat launch open to the public without any fees. FREE BOAT LAUNCH space 300 indicates that no rental is due for any player landing his or her token upon the space. Similarly, FREE BOAT LAUNCH space 300 also includes a picture 340 , which in this case, is preferably illustrative of a boat launch site.
[0075] If a player's token lands upon GO TO JAIL space 400 , that player must place his or her token in an IN JAIL portion 204 of IN JAIL/JUST VISITING space 200 . A player whose token is in the IN JAIL portion 204 must remain in that space until a dice throw on his or her next turn (or his third turn) is a “double”. If no such double is thrown by the player's third consecutive turn, he or she must pay a $50 fine to the Bank to be freed. A “double” is a dice throw in which each die results in the same number. For example, one type of “double” includes the situation when a “3” is displayed by each of two dice. Once freed from the IN JAIL portion 204 , the player moves his or her token to the JUST VISITING portion 205 of the space 200 .
[0076] When a player lands upon the IN JAIL/JUST VISITING space 200 in the ordinary course of play, the player places his or her token in a JUST VISITING portion 205 of the IN JAIL/JUST VISITING space 200 to indicate that he or she is “just visiting”, and is not subject to imprisonment as described above. A player's token is also placed in the IN JAIL portion 204 if he or she rolls doubles thrice in succession during a turn or draws a “GO TO JAIL”-type Sunken Chest or Makin A Wake card, each of which is described in greater detail below.
[0077] At the beginning of the game, players start moving their tokens from GO space 100 . As the continuous path wraps around and reaches GO space 100 , players will inevitably either land upon, or pass over, GO space 100 , thus completing a full circuit of the path. Because the path is continuous, there is no point along the board at which play terminates or a player wins. Instead, the termination of play is determined by other facets of the game, the details of which are discussed below. If a player's token lands upon, or passes over, GO space 100 , that player collects $200 from the Bank.
[0078] The Makin A Wake spaces 170 , 320 , 460 and Sunken Chest spaces 120 , 270 , 430 represent some of the ups and downs of life on a lake. Metaphorically speaking, a wake from a boat may sometimes tip a boat over, while at other times lift a boat high up in the air. Similarly, a chest found at the bottom of a lake may hold a surprise or two for a person opening it up.
[0079] If a player's token lands upon one of the Makin A Wake spaces 170 , 320 , 460 or Sunken Chest spaces 120 , 270 , 430 , he or she must draw a card from the appropriate one of two piles stacked face down at the respective spaces 30 , 40 , as illustrated in FIG. 1A. As best illustrated in FIGS. 3A through 3D, each of the Makin A Wake cards 500 , 505 , 510 , 515 , 520 , 525 , 530 , 535 , 540 , 545 , 550 , 555 , 560 , 565 , 570 , 575 has indicia thereon announcing one of a benefit, a penalty and an instruction to move the drawing player's token 20 to a particular space on the board 10 . Similarly, as best shown in FIGS. 3E through 3I, each Sunken Chest Card 600 , 605 , 610 , 615 , 620 , 625 , 630 , 635 , 640 , 645 , 650 , 655 , 660 , 665 , 670 , 675 has indicia thereon announcing one of a benefit, a penalty and an instruction to move the drawing player's token 20 to a particular space on the board 10 . Preferably, a plurality of the Makin A Wake cards 500 , 505 , 510 , 515 , 520 , 525 , 530 , 535 , 540 , 545 , 550 , 555 , 560 , 565 , 570 , 575 and/or Sunken Chest cards 600 , 605 , 610 , 615 , 620 , 625 , 630 , 635 , 640 , 645 , 650 , 655 , 660 , 665 , 670 , 675 have lake-related indicia associated with a penalty, benefit or instruction. After following the instructions indicated by the indicia printed thereon, the drawing player returns the card face down to a bottom of the appropriate pile at the respective space 30 , 40 .
[0080] As best illustrated in FIGS. 1B, 1C, 1 E, 1 F, 1 H and 1 I, in a preferred embodiment, each of the Makin A Wake spaces 170 , 320 , 460 , and Sunken Chest spaces 120 , 270 , 430 includes a picture 174 , 324 , 464 and 124 , 274 , 434 , respectively, illustrative of life at a lake. For example, the Sunken Chest picture 124 , 274 , 434 can be an ornamental illustration of a treasure chest, and the Makin A Wake picture 174 , 324 , 464 can be a scene of a boat traveling fast enough to create a wake in the water. Moreover, as best illustrated in FIGS. 3A through 3I, each Makin A Wake card 500 , 505 , 510 , 515 , 520 , 525 , 530 , 535 , 540 , 545 , 550 , 555 , 560 , 565 , 570 , 575 and Sunken Chest card 600 , 605 , 610 , 615 , 620 , 625 , 630 , 635 , 640 , 645 , 650 , 655 , 660 , 665 , 670 , 675 will either grant a particular benefit, assign a particular penalty, or instruct the drawing player to move his or her token to a particular space, and a picture 501 , 506 , 511 , 516 , 521 , 526 , 531 , 536 , 541 , 546 , 551 , 556 , 561 , 566 , 571 , 576 , 601 , 606 , 611 , 616 , 621 , 626 , 631 , 636 , 641 , 646 , 651 , 656 , 661 , 666 , 671 , 676 illustrative of the benefit, penalty or instruction is also born thereon. More preferably, they are illustrative of the associated benefit, penalty or instruction. More preferably, they are illustrative of a benefit or penalty associated with life at a lake. Descriptions for preferred pictures 501 , 506 , 511 , 516 , 521 , 526 , 531 , 536 , 541 , 546 , 551 , 556 , 561 , 566 , 571 , 576 , 601 , 606 , 611 , 616 , 621 , 626 , 631 , 636 , 641 , 646 , 651 , 656 , 661 , 666 , 671 , 676 may be found in Tables III through VI. Obviously, the invention scope includes any and all illustrations, pictures, designs, schematics, etc. that represent life on a lake.
TABLE III Makin A Wake cards Description of Benefit or Penalty Description of Picture “Skier down: go back Illustration of a ski boat three spaces.” speeding away from a water skier flailing in the water, 501. “Ticket for no life Illustration of a judge preserver: pay $15.” holding a gavel while sitting at a desk between two flags, 506. “Set sail to Liberty Lake. Illustration of a sailboat If you pass GO, collect $200.” sailing on a lake, 511. “Take a walk on the lakeshore: Illustration of a boardwalk advance token to beautiful Lake extending around a marina, Couer D'Alene.” 516. “Skier down: go back three Illustration of a ski boat spaces.” speeding away from a water skier flailing in the water, 521. “You overpay interest on your Illustration of a first hand boat loan: bank pays you $50.” handing over paper money to a second hand, 531. “Water ski to Thomson Lake. If Illustration of a person you pass GO, collect $200.” water skiing on a lake, 526. “Pull up anchor and race to GO: Illustration of a boat collect $200.” speeding across a lake, 536. “Go to Jail. Do not pass GO. Illustration of a Coast Guard Do not collect $200.” boat with a flasher towing a smaller boat, 541. “Make a wake to Sun Runner ™ Illustration of a Sun Runner Dealership.” boat, 551. “Get out of Jail freel!“ Illustration of birds peacefully flying across a sunlit sky, 546. “If Dealership is unowned, you Illustration of a boat on a may buy it from the Bank.” lake, 556.
[0081] [0081] TABLE IV Additional Makin A Wake cards Description of Benefit or Penalty Description of Picture “Win Fishing Derby: collect Illustration of a person on a $150.” lakeshore holding up a fish larger than himself, 561. “Set sail to the nearest Dam. Illustration of a Dam, 571. If unowned, you may buy it from the Bank. If owned, throw the dice and pay the owner ten times the amount shown.” “Set sail to the nearest Illustration of a boat, 566. Dealership and pay the owner twice the rental to which he or she is entitled.” “Set sail for the nearest Illustration of a boat, 576 Dealership and pay the owner twice what he or she is entitled.”
[0082] [0082] TABLE V Sunken Chest Cards Benefit or Penalty Description of Picture “Sell vintage Cris Craft ™, Illustration of one hand collect $200.” handing paper money to another hand, 606. “Your boat broke its prop: pay Illustration of a boat on a $40.” lake that has just lost its prop to the bottom of the lake, 601. “You have won second place at Illustration of a boat Lake Pend Oreille Poker Run: speeding across a lake, 611. collect $100.” “Buy new camping gear for Illustration of campsite, weekend at Lake Roosevelt: pay volleyball court and $150.” treeline adjacent a lakeshore, 616.
[0083] [0083] TABLE VI Additional Sunken Chest Cards Benefit or Penalty Description of Picture “Complete boating safety course Illustration of a person and enjoy insurance discount: wearing a graduation-style collect $20.” cap and gown in front of a boat on a trailer, 626. “Restored ski boat wins 1 st Illustration of a first Prize in boat show: collect $50 place ribbon and a boat, from each player.” 631. “You won the Long Lake Poker Illustration of a boat run: collect $25 from every speeding across a lake, 636. player.” “Take a cruise to GO: collect Illustration of a cruise $200.” ship sailing on a lake, 641. “Boat needs repairs: pay $200.” Illustration of a outboard boat motor and a pipe wrench, 651. “Go to Jail. Do not pass GO. Illustration of a Coast Do not collect $200.” Guard boat with a flasher towing a smaller boat, 656. “Overcharged for boat repair: Illustration of a person collect $25.” smiling and receiving paper money from another person, 661. “Win fishing bet by catching Illustration of a person on prize steelhead in Lewiston: a lakeshore holding a fish collect $100 from the player on larger than himself and of a your right.” hand handing over paper money, 671. “Sell old boat trailer: collect Illustration of a boat $45.” trailer attached to a truck, 676.
[0084] A roll of doubles allows a player, after completing any actions associated with the space their token is moved to, to roll the dice again without having to wait for a next turn. In this fashion, a player may roll doubles twice or thrice during a single turn. If, however, a player rolls doubles three times in succession during a turn, they must to jail and place their token in the IN JAIL portion 204 of the IN JAIL/JUST VISITING space 200 .
[0085] The object of the game is to force all the other players to quit the game because of their inability to meet their financial obligations that develop as the game proceeds. Because each player's token will from time to time land upon a lake area, boat dealership or dams owned by another player, the trespassing player will incur rental charges. Moreover, a player's token will inevitably land upon other spaces exacting some sort of financial penalty. If unable to pay his or her obligations in scrip on hand, the player must dispose of his or her property, i.e., lake areas, boat dealerships, dams, lake cabins, and marinas. Lake areas, boat dealerships and dams may be given to the creditor in satisfaction of the rental payment, sold to any other player, auctioned to the highest bidder, or mortgaged to the Bank in order to raise enough scrip to satisfy the rental payment. Lake cabins and marinas may not be sold to other players, but may be sold back to the Bank at half the purchase price listed on the associated title deed card.
[0086] As mentioned above, lake areas, boat dealerships and dams may be mortgaged to the Bank for a mortgage amount listed on the associated title deed card. Once one of the above is mortgaged, the mortgaging player must turn the title deed card face down to indicate that it is mortgaged. If the player wishes to later pay off the mortgage, he must pay back to the Bank the amount of the mortgage principal, plus, according to preferred rules of the game, ten percent interest. If a mortgaged property is transferred to another player without first lifting the mortgage, the new owner must pay ten percent interest immediately upon transfer. In order to lift the mortgage, the receiving player must pay the mortgage principal and an additional ten percent interest. According to preferred rules, no player may mortgage a Lake Area without first selling back to the Bank all of his or her Lake Cabins and Marinas erected upon that Lake Area. As a result of mortgaging a property, no rental payment may be demanded for it if another player trespasses upon that property.
[0087] If the trespassing player is unable to meet his or her obligations by selling, transferring or mortgaging lake areas, boat dealerships, dams, lake cabins and marinas, he or she is declared Bankrupt and must quit the game. All of the Bankrupt player's scrip must be given to his or her creditor. All of the Bankrupt player's Lake cabins and marinas must be sold back to the Bank at half price and the scrip given to his or her creditor. All of the Bankrupt player's remaining lake areas, boat dealerships and dams must then be sold by the Bank to the highest bidder(s), or if no bid on a property is made, given to his or her creditor. The scrip resultant from the sale goes to the creditor. If the creditor receives a mortgaged property, the creditor must immediately pay a ten percent interest charge on the mortgage to the Bank as described above, and may optionally pay off the mortgage principal at that time. If the principal is not paid at that time, an additional ten percent interest will be due at the time the principal is actually paid.
[0088] Play of the game continues until all but one of the players is Bankrupt. Thus, the remaining player is declared the winner.
[0089] It is to be understood that the present invention is not limited to the embodiment described above, but encompasses any and all embodiments within the scope of the following claims. | A game includes: a playing board; a plurality of tokens representing identities of players playing the game; a plurality of title deed cards; a plurality of game pieces; a source of scrip; a plurality of cards each one of which bears indicia related to one of a penalty, an award and a direction; and at least two elements operable by the players in turn for randomly determining movement of the tokens upon the board. The playing board includes a plurality of successive, contiguous spaces defining a continuous path about a periphery of the board. First second and third sets of the spaces identify properties, such as lake areas, dams and boat dealerships, that may be purchased with scrip by a player landing upon the respective space. Title deeds bear indicia indicating a rental payment. | big_patent |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Application Ser. No. 60/828,262, filed Oct. 5, 2006, entitled “Device for Active Treatment and Regeneration of Tissues Such as Wounds,” which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention concerns a new device and method for treating tissues and open wounds and accomplishing directed tissue growth.
BACKGROUND
[0003] Patients with open wounds, which cannot be sutured edge to edge, constitute a major health problem. Such wounds, which may include exposed muscle, tendon or bone, tend to become chronic. Poor blood supply, infection and dehydration are causative factors. Prolonged institutional care is usually required. Non-surgical treatment is usually followed by reconstructive surgery by means of skin grafts, composite tissue transfers or tissue regeneration.
[0004] Occlusive, pliable film dressings prevent dehydration and facilitate healing, but only in very superficial open wounds. In deeper wounds, “active” dressings permitting either supply of saline or therapeutic agents and/or suctioning of the wound surface improve healing by reducing tissue swelling, aiding contraction and stimulating healing. Continuously administered solutions influence the wound by diffusion processes. Therapeutic agents may constitute antibacterial substances for treating infection, enzymes for dissolution of non-viable material, growth factors or genes in tissue regeneration. Also cells may be supplied. In clean wounds, dressings combining fluid supply and drainage may facilitate adhesion of meshed skin grafts.
[0005] Wound suctioning by means of fluid-absorbing dextranomer beads (range of pressure depending on the degree of saturation of the beads; maximal suction −200 mmHg, that is 200 mmHg below atmospheric) has been reported. A cellular or fibrous (polyurethane, polyester etc) dressing pad with open pores with or without capillary activity, which may comprise layers with different qualities, and which is fitted with an impermeable cover sheet, was described in U.S. Pat. No. 4,382,441 and is incorporated herein by reference. Fluid is administered to the supply port of the said pad by pressure and/or drained from a drainage port by suction, and the supply tube contains a regulator valve. Fluid may thus be supplied to the pad 1) freely without or with suctioning, 2) in a rate-limited way combined with suction at the drainage port, or the fluid supply may be closed and the pad exposed only to suctioning. Using this invention, the wound was exposed continuously both to wetting and suctioning (−150 mmHg and −40 mmHg). Devices allowing intermittent or continuous fluid supply and/or suction drainage through a “spacer” comprising of a matted polyester fiber or polyurethane foam pad placed between the wound and the covering sheet were developed.
[0006] The dressing according to U.S. Pat. No. 4,382,441 may also be used for achieving tissue regeneration. An operational example in this said patent discloses that the open polymer dressing pad may be applied on a cell growth substrate (a collagen fiber scaffold, used in tissue regeneration, constitutes one such substrate). Also, growth substances may be supplied from said pad to the substrate, components of the substrate may be replaced and degradation products removed. A dressing according to the invention, used as a viability-maintaining device in vitro, i.e. a bioreactor, is described as an operational example in said patent.
Functional Aspects of the Open Pore Dressings
[0007] During fluid supply and suctioning through an occlusively applied open pore dressing described in U.S. Pat. No. 4,382,441, the fluid volume forced by suctioning from capillaries and wounded tissue becomes added to that administered through the supply port. Functional aspects of this treatment are demonstrated in vitro in Examples 1-3. Example 1 suggests that in the presence of an unchanged flow resistance—located either in the fluid supply to the dressing or in the tissue—drainage fluid flow rate and suction pressure are directly correlated. The direct correlation between pressures in the drainage port and pad in a wide pressure range (Example 2) confirms previous findings ( 5 ). The dressing pad (Example 3) remains partially saturated even when treatment fluid is supplied at a rate of 7,200 mL/24 h. In vivo, treatment fluid is given at an approximate maximal rate of 2,400 mL/24 h, and the average rates by which tissue fluid form may range from 50 to 1,000 mL/24 h. The combined “maximal” in vivo fluid load of 3,400 mL/24 h (2,400+1,000 mL) thus clearly suggests a partially saturated state (3,400 mL/7,200 mL). The suctioning effect on the wound becomes abolished only when fluid or gas is allowed to enter the dressing freely or when the open pores have become clogged by biological material.
Malfunction and Limitations of Open Pore Dressings Used for Combined Fluid Supply and Wound Suctioning on a Continuous or Intermittent Basis
[0008] Fluids may be supplied to the dressing either continuously by hydrostatic force from a drip stand, or by propulsion pump. Malfunction related to the hydrostatic pressure of the supplied fluid is at present neither recognized nor corrected for. Elevation of the fluid bag of a gravity drip for instance 68 cm or 136 cm above the dressing yields hydrostatic pressures of +50 and +100 mmHg respectively at the supply port. Dependency of the fluid bag relative to the dressing has the opposite effect. Pressure pumps expose the supply port to higher positive propulsive pressures, and may also include a significant positive or negative hydrostatic pressure component.
[0009] Viscous and particulate material or clots may predispose to gradual blocking of hydrophilic, capillary-active dressing pores, in particular near the drainage port. This will reduce the rate of fluid transport and also the suctioning force exerted on the wound surface. An eventually elevated hydrostatic pressure at the supply port becomes transmitted through the dressing pores to the blockage. Once the hydrostatic pressure exceeds the resistance in the dressing, a leak may result in overflow with wetting and soiling. If such blocking events are to be detected, complex electronic controls involving both supply and drainage would be required. A pressure sensor may reproducibly detect a pressure of +100 mmHg, but in a range extending towards +20 mmHg, the rate of false positive alarms will increase and reduce treatment practicality in a resource-demanding way. A simple and reproducible apparatus and method for eliminating hydrostatic pressure and achieving reliably a standardized combination of continuous therapeutic fluid supply with warning of impending dressing pore blockage is lacking, both in clinical wound treatment and tissue regeneration.
[0010] Known open pore dressings with supply and/or drainage ports (e.g., Principal AB, Malmö, Sweden; Kinetic Concepts, San Antonio, USA) lack means for reliable intermittent administration of saline or drug solution by injection during ongoing suctioning at the drainage port. Although local injection through the supply port can be accomplished with such devices, the need to leave the port open when fitting and removing a syringe or small volume fluid bag leads to immediate pressure equilibration between air and pad both before and after injection of the dosage. The first results in evacuation of the fluid representing the continuously supplied dosage from the pad, and the second in evacuation of the locally injected dose. A reliable apparatus and method for distributing treatment fluid intermittently to the wound tissue during continuous suctioning is thus lacking.
[0011] Bleeding from the wound during ongoing suctioning is an infrequent but at times life-threathening complication, which manifests itself by blood or plasma being sucked from the dressing. A simple means which may allow reproducible early detection of bleeding during ongoing suctioning is lacking.
SUMMARY
[0012] In one or more embodiments, the use of positive hydrostatic or pump pressure as driving force for supplying fluid continuously to the open pore dressing is eliminated or minimized, and treatment fluid is sucked through the dressing pores by means of the suction pump used for distributing negative pressure to the wound. The placement of a fluid bag in bed at the level of the wound is impractical and prone to physical disturbance. Instead, the fluid reservoir (usually a pliable fluid bag) is placed on a support comprising a sloping or horizontal surface and the hydrostatic pressure is eliminated or minimized (i.e. to the level required for neutralizing flow resistance) by moving this said support vertically along a pole. This latter allows the fluid bag to be manually or automatically positioned level with the wounded tissue irrespectively of its height above the floor. The positioning may be facilitated using a horizontal level measuring device. In this apparatus and method, dependent on suctioning for function, one sensor which measures fluid supply rate will suffice for detecting malfunction.
[0013] A fluid administration set, intended to be used with the said fluid bag resting on said sloping or horizontal surface, comprising a drip chamber with angulated entry channel, which allows drops to fall freely, permits visual or automatic drop count. The said set may be fitted with a horizontal level meter and an injection port.
[0014] A supply port comprising of an elastic injection membrane is described. Intermittent doses of saline or drug solution can be administered against a resistance (cannula, syringe piston/wall contact, iv set rate-controlling device) from a syringe or fluid bag through this said elastic membrane to a dressing exposed to suctioning. This injection mode blocks air entry during connection and removal of the syringe, and allows the supplied fluid to distribute evenly throughout the dressing and over the wound surface as a result of vacuum and capillarity. Once fluid is detected visually in the suction tube a full intermittent dose has been given.
[0015] To prevent blocking the dressing pores at the drainage port by biological material, a suction port device is disclosed which contains an open grid means interposed between the whole area of said port and the open polymer dressing. This device maximally increases the area of dressing directly exposed to suctioning, augmenting the capacity of said port to eliminate particles and debris and increasing the duration of full function of the open pore dressing.
[0016] When using the dressing to supply nutrients for tissue regeneration, the rates of fluid transport and suctioning in the scaffold can be reduced to low levels to leave diffusional and cellular processes undisturbed. This is accomplished either by avoiding or minimizing hydrostatic pressure or pump head (to a level just sufficient to overcome both supply tube and open pore or tissue scaffold flow resistance) and applying concomitantly weak suction at the drainage port. In this latter situation more complex monitoring may be included.
[0017] An apparatus and method of allowing detection and warning of bleeding from a wound treated by suctioning comprising a computer connected with a scale, which measures serially the weight of the fluid sucked off the wound into an immobilized canister, and gives warning when the rate of fluid formation increases beyond that measured prior to the bleeding.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Embodiments of the present invention will now be described by way of example only and with reference to the accompanying drawings of which:
[0019] FIG. 1 shows a schematic view of a dressing system, according to an embodiment of the invention.
[0020] FIG. 2 shows two schematic cross-sections of another embodiment of the vertically movable rest including an alternative means for fixing said pole via a hook that can be clamped to the footboard of a bed.
[0021] FIG. 3 shows schematically an embodiment which includes motorized means for moving and fixing said platform at the desired level relative to the wounded tissue.
[0022] FIG. 4 shows a schematic cross-section of a fluid administration set for treating wounded tissue.
[0023] FIG. 5 shows an embodiment of said fluid administration set which includes a level meter and an injection port.
[0024] FIG. 6 shows a schematic cross-section of an open pore polymer dressing.
[0025] FIG. 7 shows a schematic cross-section of a non-protruding membrane injection port allowing intermittent supply of fluid during suctioning.
[0026] FIG. 8 shows a schematic perspective view of said port integrated in a dressing cover sheet used for self-assembly.
[0027] FIG. 9 shows a schematic cross-section of another embodiment of a membrane injection port invention.
[0028] FIG. 10 shows a schematic cross-section of a drainage port invention with open grid.
[0029] FIG. 11 shows a schematic cross-section of dressing having an open pore dressing overlying a scaffold used for tissue regeneration, according to another embodiment of the invention.
[0030] FIG. 12 shows a schematic cross-section of a device for detecting bleeding from the wound.
DETAILED DESCRIPTION
[0031] FIG. 1 shows one embodiment of the apparatus according to the invention. The dressing is sealed to the wounded tissue by means of a pliable polymer sheet. Treatment fluid contained in a pliable bag reservoir is connected to the supply port of the dressing by way of flexible tubing, while a suction pump is connected by tube to a drainage port. Fluid bag and horizontal level meter are placed on a rest which is movable along a pole in a vertical direction, and can be fixed in a position which is level with the wound. The pole is fixed on a base which holds a suction pump with canister.
[0032] More specifically, patient 1 is being treated with an open polymer dressing pad 2 sealed to the wounded tissue by means of a pliable polymer sheet 3 . The means for accomplishing fluid flow comprises a pliable bag filled with treatment fluid 4 which is placed on rest 5 . This bag connects by its outlet 6 to a drip chamber 7 which is followed by a flexible supply tube 8 comprising a fluid rate controlling device 9 and injection port 10 before connecting with the supply port 11 of the dressing 2 . A rest 5 which is sloping in the area of the fluid bag is shown. The bag 4 is positioned on rest 5 with outlet 6 dependently, facilitating complete drainage and displacing eventual contained air upwards. The rest 5 can maintain fluid bag 4 in a flat or inclined plane in a range between 0° and 30°, allowing full fluid evacuation without, or with minimal, height difference between full and empty bag. A dressing drainage port 12 is connected by tube 13 to suction pump 14 . Suction pump 14 and/or its fluid canister 15 may be connected to the line of suction anywhere—including on rest 5 —where it may effectively drain fluid and prevent build-up of significant hydrostatic pressure within said tube 13 . Canister 15 may be fitted with a scale 16 to allow determination of fluid volumes. The suction pump 14 may be fixed to the base 17 , pole 18 or rest 5 by means of a screw, clamp or elastic strap. Rest 5 is movable in vertical directions along pole 18 and fixed by means of a clamp 19 in a position where the fluid surface in bag 4 and the supply port 11 of the dressing are level, i.e. the hydrostatic pressure at port 11 is at or near zero. This adjustment may be accomplished using a height indicator means 20 which may be connected with said rest 5 . The means 20 may constitute for instance a horizontal level meter fixed either to a rewindable cord or to the proximal end of tube 8 , or alternatively a telescopic pole or low energy red laser pointer connected with rest 5 . The base 17 may be fitted with wheels 21 . The rest 5 , pole 18 , and base 17 can for instance be made of aluminium, stainless steel or polycarbonate. Rest 5 can be moved along pole 18 manually, and locked at a suitable level by said clamp 19 , or the pole may be height adjustable, constituted for instance of telescoping tubular sections which can be locked by screws at required length. The disclosed base 17 with pole 18 and rest 5 may be adapted for self-assembly.
[0033] FIG. 2 shows an embodiment of an apparatus according to the invention, which rids the rest 5 and its pole 18 of contact with the floor. In this device the footboard 22 of the bed is used as base. The construction minimizes the area of working-space occupied by the treatment devices and tubing. Rest 5 with U-shaped pole 18 is fastened to the footboard 22 by means of a hook-like structure 23 which may comprising elastic polymer or metal. The U-shape of pole 18 may allow positioning of rest 5 within a vertical range corresponding to the combined length of the two parallel vertical parts of pole 18 , allowing the total length of pole 18 to be minimized. Immobilization of pole 18 is achieved by means of clamps 19 and 24 . The fluid bag 4 , placed on rest 5 with its outlet 6 dependent, is kept in place by vertical bars 25 . An ultrasound distance sensor 26 is fixed to hook 23 —for instance by means of an elastic or rewindable cord 27 —and used for determining the horizontal level by measuring distances from wound and fluid bag to the roof. The device according to FIG. 2 may also be adapted for self-assembly. The straight pole 18 shown in FIG. 1 may fit in clamp 24 shown in FIG. 2 and used as an alternative to the u-shaped pole.
[0034] FIG. 3 shows an embodiment of an apparatus according to the invention, which may allow automatic movement and fixation of a horizontal rest 5 at a height along said pole 18 corresponding to the level of the wounded tissue at the press of a button. This may be accomplished by means of a unit comprising a computer 28 connected electronically with ultrasound sensors 26 and 29 and an electrical motor 30 . The said motor 30 operates a cog-wheel 31 which meshes with another toothed part 32 extending along pole 18 . Wire-based or hydraulic mechanisms may also be used. Once the said computer 28 receives for instance telemetric input on the distance from the wounded tissue to the roof from sensor 26 after activation by the therapist, computer 28 activates sensor 29 and moves rest 5 vertically to the same level. The said rest 5 may maximally be moved vertically in a range from 10 cm to 200 cm above floor level, which corresponds approximately to that of a lower leg wound on a sitting or standing patient and a wound on the head of a standing patient. The range of movement may also be restricted to fit patients lying or sitting in bed, with a range from 30 cm to 150 cm above floor level.
[0035] FIG. 4 shows an embodiment of an apparatus used according to the invention for administering treatment fluid from a fluid bag in a sloping or horizontal position. It comprises a transparent drip chamber 7 with an angulated entry channel 33 between the spike 34 and chamber 7 . Said angulated entry channel 33 may be rigid or elastic, bendable to a chosen angle, and preferably made of polymer material. The chamber 7 is made of rigid polymer material. Tube 8 is made of pliable polymer material whose walls may be Luer format. The tube is fitted either with a roller clamp 9 or other mechanically or electronically operated device for controlling the flow rate—accomplished either by external compression of tube 8 or another known means of lumen reduction—and finally includes a connector 35 to the dressing supply port 11 . The angulated entry channel 33 permits the chamber 7 to be approximately vertically positioned with the connected fluid bag placed on sloping or horizontal rest 5 . This allows drops to fall freely in the chamber, permitting secure reading of the drip rate. Drip chambers of interest allow 40-80 drops per ml when exposed to negative pressures as high as 150 mmHg. Standard Luer format of tube 8 , roller clamp 9 and connector 35 may be used but not obligatorily. The connector 35 to be fitted on the dressing port tube may alternatively constitute an elastic tube.
[0036] FIG. 5 shows a further embodiment of apparatus according to the invention to administer treatment fluid from a fluid bag. It differs from that described in FIG. 4 by including a horizontal level meter 36 and a tubular injection port connector 37 . The latter may include tap 38 for directional control. The tubular connector 37 may be substituted by an elastic injection membrane. Said level meter 36 , comprising for example a small gas bubble enclosed in a transparent glass tube filled with liquid fluid, is connected with the tube 8 for instance by arms 39 embracing tube 8 . The level meter 36 should preferably be positioned near the drip chamber 7 to allow the meter 36 to be read while adjusting the height of the fluid bag 4 on rest 5 to match that of dressing 2 . Connector 37 may be used for adding a drug dose to pad 2 during ongoing continuous supply and suctioning. To achieve optimal drip rate readability in chamber 7 of the embodiments shown in FIGS. 4 and 5 , the combined angle of entry channel 33 and rest 5 for the fluid bag should be 90°.
[0037] Both the supply tube 8 and suction tube 13 may be thick-walled and/or corrugated at the inside to withstand kinking and compression, with inner diameter of approximately 3 mm. The suction tube 13 and canister 15 may be manufactured in pliable polymer materials. The sensor which measures fluid supply rate is suitably connected with an alarm.
[0038] In special situations, in particular associated with low-flow tissue culturing applications using pressure pumps, monitoring of volume rates of fluid supply and drainage may be included, as may pump head pressure and inadvertent gravity free flow. The propulsing force or head of the pressure pump should be just sufficient to achieve fluid flow. The pump should suitably be connected with a pressure sensor in the tube 8 or pad 2 to allow detection and adaption to a pump-related pressure disturbance. Computerized alarms concerning start/stop, occlusion, overflow and air-leak conditions may be applied. Known pressure and/or ultrasonic transducers or optical sensors may be used. A drip-sensing device may be attached to drip chamber 7 . A timer-activated clamp may allow the fluid supply tube of a drip set to open and close at user-defined intervals, and a timer may control the start-stop function of the suction pump.
[0039] FIG. 6 shows an example of an open pore dressing with its pad 2 placed on the wound 40 and covered by a pliable, adhesive film or sheet 3 , which is adhered to the adjacent skin 41 . One supply port 11 and one drainage port 12 are adhered to the sheet 3 at a distance from each other. Each port is fitted with a tubular member, which allows the port to be connected to known supply or drainage tubes. Corresponding to these ports, apertures through the said sheet 3 allow access to pad 2 for fluid supply and suction drainage respectively. Flexible tubes are connected airtightly with the said ports 11 and 12 , for instance by means of luer lock or elastic tube being forced over a conical rigid and tubular end-piece. The said sheet 3 , ports 11 , 12 and tubing 8 , 13 provide a seal which allows the negative pressure within pad 2 and on the surface of wound 40 to be contained at a predefined level at least during operation of the suction pump. Pad 2 may comprise cell material with open pores or spatia like polyurethane or polyester foam or polyester fibers, and the latter may be matted. Pad 2 may include layers in which the pores and/or spatia have different dimensions. A thin dressing layer sandwiched between pad 2 and the wound surface may comprise knit or woven biofiber like cotton, wool or silk containing capillary functioning pores. This layer may be cut to fit sensitive areas of the wound where blood vessels and nerves are superficial or exposed. The sheet 3 may be fluid- or air-impermeable and is typically produced in polymer material (Minnesota Mining and Manufacturing, St. Paul, Minn. 55144). Pad, ports and tubes may be assembled either during fabrication, or bedside by the user. In a method according to the invention intended for treatment of wounds by means of the dressing shown in FIG. 6 , the pressure at the supply port of the dressing is typically 0 mmHg, including correction for tube friction. This level of pressure is combined with suctioning at the drainage port ranging between −20 mmHg and −200 mmHg. This treatment may be applied intermittently or continuously for variable periods of time. The maximal suction applied under these circumstances is −760 mmHg. Fluid is supplied according to the invention at rates which may vary between 100 ml/24 h and 2,000 ml/24 h and loading doses for filling the dressing with drug solution may vary between 1 ml and 500 ml. This treatment may be undertaken on a continuous or intermittent basis.
[0040] An injection port device can be used for adminstering treatment fluid intermittently to the complete wound surface underneath dressing pad 2 . This administration is always accomplished during ongoing suctioning through the drainage port 12 . This apparatus, shown in FIG. 7 , comprises an elastic membrane 42 which must have qualities which allow maintainment of occlusion after being perforated repeatedly by a needle. Membrane 42 may be connected adhesively to sheet 3 , and the construction may or may not include a hole in said sheet 3 corresponding to the center of membrane 42 . In connection with injection by needle through said membrane 42 , the elastic qualities of membrane 42 should prevent formation of needle holes which could result in elimination of the vacuum in dressing pad 2 . The membrane device may also be available as a separate unit with an adhesive rim at its circumference, the latter covered by removable protective paper, whereby said device can be applied adhesively around a hole in a dressing sheet 3 in a known manner. Finally, an adhesive, reusable and pliable lid may be placed on membrane 42 to maintain sterility between injections.
[0041] FIG. 8 shows an injection port apparatus according to FIG. 7 which is integrated in a pre-fabricated dressing sheet 3 intended for self-assembly, such that the dressing becomes complete by inclusion of dressing pad 2 and drainage port 12 .
[0042] FIG. 9 exemplifies another embodiment of the said injection port apparatus, and comprising a rigid frame 43 which may be circular, and which is adhesively connected with the edges of a hole made in flexible sheet 3 covering the pad 2 . The frame is likewise airtightly connected with elastic membrane 42 . Frame 43 may be fitted with a lid 44 , a handle 45 , a joint 46 and a flange 47 . When the device is not in use, lid 44 is closed over membrane 42 . In this process, flange 47 enters a slit 48 in frame 43 to maintain secure occlusion. The membrane may optionally be protected by an adhesive tape patch 49 when not in use. Underneath the said membrane 42 is a rigid impermeable plate 50 which is connected by side walls 51 to said frame 43 , and said walls 51 are fitted with apertures 52 . The plate 50 may prevent the needle from inadvertently entering the wounded tissue in situations where the pad is thin. The membrane of the device according to FIG. 9 can suitably be manufactured in natural or synthetic rubber or elastic polymer including silicone. The frame, lid and plate structures may be manufactured in, for example, known, rigid polymer materials, and plate 50 may contain metal to prevent needle penetration. In operation during ongoing suctioning the lid 44 is opened by its handle 45 , the piece of tape 49 is removed. A needle connected with a fluid-filled syringe is advanced through said membrane 42 while the membrane 42 is stabilized by holding lid 44 . The fluid is slowly injected, allowing it to become distributed throughout the dressing by suction and capillary force. The supply of fluid may be terminated once fluid appears in the drainage tube. After injection the needle is removed and tape 49 and lid 44 are repositioned.
[0043] FIG. 10 shows an embodiment of an apparatus according to the invention comprising a drainage port which facilitates drainage of debris through a capillary-active dressing pad. It comprises a drainage port tube 53 with flange 54 sealed to pad 2 by means of an adhesive sheet 3 . An open grid 55 adhered to the flange covers the entry to the opening 56 in the flange in order to avoid obstruction of dressing material against the edges of said opening 56 . The grid is preferably manufactured of semi-flexible or rigid cells with open pores or spatia made of polymer materials, for instance polyester, polyurethane or steel wool, all typically less compressible to suction than dressing pad 2 .
[0044] FIG. 11 shows an apparatus and method according to the invention comprising an open polymer pad 2 overlying a tissue culturing scaffold 57 used for regenerating skin tissue in a wound 40 . The adhesive cover sheet 3 , the supply port 11 and suction drainage port 12 are indicated. Depending on which type of tissue is to be regenerated, the scaffold may comprise biological and/or non-biological material. A biological scaffold may comprise collagen or dermis, hyaluronic acid or fibrin. When regenerating bone the scaffold may comprise bioactive ceramics or glass. Non-biological polymer fiber scaffolds may be biodegradable and comprise, for example, poly-glycolic acid polyester (PGA) or related substances. The optimal pore size of the scaffold may vary with the phase in the growth process. Passage by diffusion of all relevant nutrients and growth substances is obligatory throughout the regenerative process, and cell and vascular structures will have to be accommodated as they develop. The scaffold may thus include a range of more narrow pores which allow passage of molecules including peptides and proteins, as well as a range of wider pores allowing passage of cells, and this pore ratio may vary with the degree of tissue development. Antibacterial substances, analgesics, enzymes, growth factors, growth media and cells, including stem cells, fetal cells and genes, may be supplied.
[0045] In a method for accomplishing tissue regeneration in vivo or in vitro, see FIG. 11 , the positive and negative pressures applied to pad 2 should be minimized in order to leave diffusional and cellular processes in the growth zone of the underlying tissue scaffold undisturbed. The forces governing the passage of fluid through the scaffold should be determined mainly by diffusion and minimal suction. This is accomplished in a controlled way by combining zero hydrostatic pressure or minimal pump head pressure in the dressing with at most weak suction at the drainage port. The hydrostatic pressure in the dressing can be 0 mmHg including compensation both for tube and open pore and/or tissue scaffold resistance. The suction pressures can range, for example, from −0 mmHg to −30 mmHg. The fluid supply rates may typically vary between 20 ml/24 h and 400 ml/24 h and loading doses for filling the dressing with drug solution may vary between 1 ml and 100 ml. This treatment may be undertaken on a continuous or intermittent basis. The pad 2 may be substituted for a tissue scaffold when the porosity of the scaffold allows passage of treatment fluid under flow and pressure conditions as defined above.
[0046] FIG. 12 shows an apparatus according to an embodiment of the invention for detecting bleeding from the wound during ongoing suctioning by a simple weighing technique. Canister 15 is immobilized in a tight-fitting receptacle 58 placed over load sensor 59 , which in turn is connected to computer 60 , display and control-panel 61 , loudspeaker 62 and telemetric unit 63 , all constructed according to the state of the art, and being part of the basal part 64 of the said apparatus. Elastical force or movement in suction tube 13 , or movement in the pump 14 in operation, is prevented from being propagated to canister 15 by means of tubular buffer organs 64 and 65 , each comprising a rigid and a pliable part. The rigid part constitutes in this example two closely fitting openings in the rigid receptacle wall 66 . The pliable tubular part 67 is designed to further minimize movement and elastic force. The rigid part of each buffer organ may comprise polymer or metal. The pliable tubular part can be made of elastic polymer fitted with an inner discontinuous “skeleton” of rigid material to prevent collapse and occlusion. The pump 14 is additionally isolated with regard to vibration by means of elastic layer 68 placed between the base of the pump 14 and the basal part of the apparatus containing the computer and control means. This part of the apparatus can be made of metal to avoid vibration and increase stability.
[0047] The scale 59 may be operated by a load cell according to the state of the art. The computer 61 measures the weight of fluid in the canister 15 at pre-set intervals, and stores and displays the data using simple state of the art technology. The computer 61 first determines the baseline rate and variability of the therapeutic fluid formation over time based on measurements for instance at 2-5 min intervals. The smallest rate of fluid formed in addition to the therapeutic rate, which is to be considered as sign of a bleeding, is decided by the user and fed into the computer 61 . The computer 61 then subtracts incoming rates from baseline serially and gives an audible, visual and possibly telemetric alarm once bleeding is detected. A bleeding in the wound may manifest itself 1) as a stepwise increase in liquid fluid weight 2) as a linear increase or 3) as an exponential increase. In a more advanced design, such patterns may also be identified and used by the computer as additional signs of bleeding. The computer can also warn of overflow of fluid in canister 15 .
EXAMPLE 1
[0048] Fluid flow rates in the dressing were studied in vitro as a function of the negative pressure applied at the suction port. The flow resistance was unchanged throughout.
EXAMPLE 1
[0049]
[0000]
Suction
Flow rate
mmHg (%)
ml/24 h (%)
−50
(−100)
144 (100)
−100
(−200)
360 (250)
−200
(−400)
624 (433)
[0050] Table I. Rate-limited fluid flow vs suction pressure in occlusively applied open polymer dressing with supply and drainage ports, studied in vitro.
[0051] The dressing comprising polyester fibers (11×13 cm) covered occlusively by polymer film and fitted with supply and drainage ports at opposing ends. The dressing was positioned horizontally.
[0052] The hydrostatic pressure at the supply port was 0 mmHg and the flow resistance in the supply was unchanged during the experiments. Fluid flow at the entry to the dressing and pump pressure were measured according to the state of the art.
DISCUSSION
[0053] In this situation with unchanged resistance to entry of fluid into the porous dressing, fluid flow rate and suction pressure were close to linearly related.
EXAMPLE 2
[0054] The negative pressure and degree of hydration in the dressing were studied in vitro as functions of the negative pressure at the drainage port.
EXAMPLE 2
[0055]
[0000]
Step 1
Step 2
Step 2
Step 3
Fluid flow
1440
1440
1440
1440
rate
(ml/24 h)
Drainage
−15
−50
−100
−200
port gas
pressure
(mmHg)
Open pore
−13
−46
−93
−180
gas pressure
(mmHg)
Dressing
52
40
50
35
fluid
saturation
(Per cent)
[0056] Table 2. In vitro assessment of pore gas pressure and fluid saturation during treatment according to the invention.
[0057] The dressing comprising polyester fibers (11×13 cm) covered occlusively by polymer film and fitted with supply and drainage ports at opposing ends. The dressing was positioned horizontally.
[0058] The hydrostatic pressure at the supply port was zero. Fluid flow was unchanged throughout the experiment. Pressure was measured in the drainage port and on the surface of the dressing pad. Dressing fluid saturation was measured by weighing, and calculated as percentage of the total saturable volume under influence of negative pressure as indicated.
DISCUSSION
[0059] Suction pressures at the drainage port and within the pad were correlated over a pressure range of therapeutic interest. The dressing pad was partially saturated with fluid (mean: 44 percent, range: 35-52 percent). Clinically, a wound would thus be exposed dynamically to a combination of wetting and suction.
EXAMPLE 3
[0060] The drainage capacity of a dressing exposed to fluid loading was studied in vitro.
EXAMPLE 3
[0061] In vitro assessment of the drainage capacity of a dressing exposed to fluid loading.
[0062] The dressing comprising polyurethane foam (10×7.5 cm) covered occlusively by polymer film and fitted with supply and drainage ports at opposing ends. The dressing was positioned horizontally.
[0063] Fluid supply was increased from 20 drops/min to 100 drops/min in steps of 20 drops. The hydrostatic pressure at the supply port was zero. The suction pressure applied at the drainage port was −50 mm Hg. The thickness of the dressing was used as a measure of its compressed volume, and measured at each step. Dressing fluid saturation was assessed in the last step of the experiment, and determined as the percentage between the fluid contained in the dressing (assessed by weighing) and the total saturable volume assessed volumetrically during maximal suctioning.
RESULT
[0064] The height of the dressing at each step of the experiment was compressed to approximately 7 mm. The dressing fluid saturation at 100 drops/min (equal to 7,200 mL/24 h) was 50/63 mL, and the maximal saturation thus 80%.
DISCUSSION
[0065] This small format dressing remains partially saturated even when fluid is supplied at a rate as high as 7,200 mL/24 h. The results indicate that drainage capacity and hence a local suctioning effect is functional in a wide volume range at a pressure of −50 mmHg.
CONCLUSION
[0066] In one embodiment, an apparatus for treating and regenerating tissues, covering a wound, combining liquid fluid supply and suction, comprises a pole, a rest, said rest being movable in vertical directions along said pole and having a clamp for securing said rest at a height corresponding to the height of the tissue, at least one fluid reservoir placed on said rest, connected to the tissue, and means for controlling the fluid supply and suction.
[0067] The rest can form an angle, for example, in the range 0-30° to the horizontal. The rest can be hinged, and immobilized in any angle from horizontal to vertical. The range of vertical movement of the rest can be, for example, approximately 10-200 cm, including for example 30-150 cm. A horizontal level meter can used for securing said rest at a height corresponding to the height of the tissue. The level meter such as a telescopic pointer, laser pointer or ultrasound sensor, can be connected with said rest directly or by means of a cord.
[0068] The fluid reservoir can comprise a pliable and flexible bag filled with treatment fluid. The fluid supply can be connected with the tissue by means of a tube.
[0069] The controlling means can include a drip chamber and a roller clamp connected with said tube. The controlling means include a drip chamber with an angulated spike connected with said tube. The controlling means can include a level meter connected with said tube. The controlling means can include an injection port connected with said tube. The means controlling the fluid supply can comprise an electronically operated valve. The means controlling the fluid supply can comprise a kink-resistant supply tube.
[0070] The apparatus can further comprise at least a drop-sensitive sensor for assessing the flow rate. The suction means can comprise a suction pump placed on the platform and connected to the tissue by means of a tube. The inner wall of said tube can be corrugated. The suction pump can be connected to a canister whose liquid fluid content can be determined by means of a scale or by weighing. The suction means can comprise a suction pump is placed on the floor. The suction means can comprise a pump is fixed to the pole by means of a clamp.
[0071] The pole is, for example, u-shaped and fixed by means of a clamp to a hook which can be fastened to the footboard of a bed. The pole can be straight and fixed to a base. The pole can comprise telescoping parts which can be locked in position by means of screws, clamps or by a hydraulic mechanism.
[0072] The apparatus can farther comprise a motor which moves said rest in a vertical direction and which is operable by means of a computer. The apparatus can also comprise ultrasound level meters, one fixed and one movable, and both connected to said computer. The apparatus can further comprise a pump used for administering the fluid supply. The pressure head of the said pump can be monitored by means of a sensor in the supply tube. The fluid flow can be controlled by means of timer activated clamps.
[0073] In one embodiment, apparatus for treating and regenerating tissues allowing administration of a restricted amount of fluid to the supply port of an occlusively applied porous dressing pad during exposure of said pad to continuous suctioning through a separate drainage port, comprising a restricting means preventing free fluid flow, a means to prevent ingress of air through said supply port in connection with said fluid administration, and a drainage port.
[0074] The supply port can comprise of an injection membrane airtightly connected with a polymer sheet. The supply port can comprise a plate at the side of the dressing pad which can prevent a needle used for injecting treatment fluid through said membrane from penetrating into the dressing and to the wound.
[0075] The apparatus can further comprise a roller clamp that provides additional restricting means. The friction between piston and syringe wall can provide additional restriction means.
[0076] In another embodiment, a method for treating and regenerating tissues allowing administration of a restricted amount of saline or drug solution to the supply port of an occlusively applied porous dressing pad during exposure of said pad to continuous suctioning, comprises: applying continuous suction to the drainage port in the range between 30 and 200 mmHg; applying an injection needle airtightly to a syringe or fluid bag filled with saline or drug solution; avoiding a fluid bag hydrostatic load; perforating said supply port elastic injection membrane with the needle during ongoing suction at the drainage port of said dressing pad; injecting the content of the syringe into the dressing pad in 1-5 minutes during ongoing suctioning at said drainage port; stopping the injection once injected fluid becomes visible through the suction tube wall as it exits the drainage port of the dressing pad; and withdrawing the said needle from the elastic membrane.
[0077] In yet another embodiment, a method for non-regenerative tissue treatment by means of combined fluid supply and suction drainage to a porous dressing, comprises: eliminating hydrostatic pressure in the fluid supply port by positioning the fluid bag at the level required for neutralizing supply tube flow resistance; maintaining the tissue hydrostatic pressure at the supply port at 0 mmHg; maintaining the fluid flow in a range between 100 ml/24/h and 2,400 ml/24 h; providing a seal which allows negative pressure to be distributed over the tissue and to be maintained at a predetermined level at least during operation of the suction;
[0000] maintaining the suction normally in a range between −20 mmHg and −200 mmHg, maximally −760 mmHg; utilizing loading doses in the range between 1 ml and 500 ml; and applying steps a-f continuously or intermittently.
[0078] In yet another embodiment, a method for regenerative treatment by means of combined fluid supply and suction drainage to a tissue scaffold, comprises: eliminating hydrostatic pressure by positioning the fluid bag at a level just sufficient to overcome both supply tube and/or open pore scaffold flow resistance; maintaining the fluid flow in the range between 20 ml/24/h and 400 ml/24 h; providing a seal which allows negative pressure to be distributed over the tissue and to be maintained at a predetermined level at least during operation of the suction; maintaining the suction in the range between −0 mmHg and −30 mmHg; utilizing loading doses in the range between 1 ml and 100 ml; and applying steps a-e continuously or intermittently.
[0079] In yet another embodiment, a method for regenerative treatment allowing artificial circulation to a tissue scaffold, comprises: eliminating hydrostatic pressure by positioning the fluid bag at a level just sufficient to overcome supply tube, porous pad and/or scaffold flow resistance; controlling fluid supply rate by interposing a pump in the supply line; monitoring the pressure head in the supply port; monitoring the pressure in the porous pad or scaffold; maintaining the tissue hydrostatic pressure at the supply port at 0 mmHg; maintaining the fluid flow in the range between 20 ml/24/h and 400 ml/24 h; providing a seal which allows negative pressure to be distributed over the tissue and to be maintained at a predetermined level at least during operation of the suction; maintaining the suction in the range between −0 mmHg and −30 mmHg; utilizing loading doses in the range between 1 ml and 100 ml; and applying steps a-i continuously or intermittently.
[0080] In another embodiment, an apparatus for treating and regenerating tissues by means of an occlusively applied dressing pad, comprises a drainage port with means to counteract occlusion of the underlying open pores of the pad when said pad is exposed to continuous suction. The drainage port means can comprise an open grid consisting of interconnected or separate units which form a pattern covering the whole underside of the port abutting the dressing pad. The grid can include the opening in the flange.
[0081] In another embodiment, an apparatus for detecting bleeding from a wound during continuous suctioning treatment comprises a receptacle, a scale, a canister, movement buffer organs, a computer, visual display, audible alarm and telemetry.
[0082] In another embodiments, a method for detecting bleeding from a wound during continuous suctioning treatment, comprises: determining the baseline rate and variability of therapeutic fluid formation over time based on measurements of net weights of fluid in the canister at 2-5 min intervals; determining of the minimal rate of fluid formed in addition to said baseline rate which is to be considered as a sign of bleeding, and feeding this information to the computer; making the computer subtract incoming rates of fluid formation from baseline serially, and giving an audible, visual and telemetric alarm once bleeding is detected. | Hydrostatic pressure of aqueous solutions—supplied from reservoir under rate control through tube to port of airtightly applied open pore dressing pad—is eliminated by levelling reservoir placed on rest with pad. Dressing pad may overlie a tissue culturing scaffold. A drip chamber with angulated channel permits drops to fall freely and be counted. Injection port elastic membrane prevents air inlet to pad while suction is applied at port, permitting fluid given under rate control through membrane to distribute evenly in pad. A drainage port flange, wholly covered by an open grid, is described. Acute wound bleeding is detected by computer-controlled serial weighing of a movement-stabilized drainage fluid canister with warning of abnormal flow rate increase. | big_patent |
This application claims the benefit of U.S. Provisional Application No. 60/186,185, filed Mar. 01, 2000 U.S. Provisional Application No. 60/159,465, filed Oct. 13, 1999. This application is a continuation-in-part of U.S. application Ser. No. 09/071,523, filed May 01, 1998, U.S. Pat. 6,276,700 B1, issued Aug. 21, 2001, which application claims the benefit of U.S. Provisional Application No. 60/045,490 filed May 02, 1997.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention most generally relates to gravity driven vehicles such as downhill racing carts. More particularly this invention relates to maneuverable, steerable gravity driven vehicles Most particularly, the invention relates to a stable, durable gravity driven vehicle which is steerable, has at least two wheels or two skis or a combination of wheels and skis and at least one brake, is ridden in a prone, face down, face forward position and which may be ridden on varied surface terrain such as dirt, grass or snow. Even more particularly this invention relates to the mechanism for suspension of the wheels and/or skis which is configured to provide precise control in turns especially the carving of turns, by the skis, while descending on snow cover.
2. Description of Related Art
Although there are various patents disclosing embodiments for devices which permit movement over a surface, the following patents known to the inventors hereof, do not in any manner suggest or teach the Gravity Driven Steerable Wheeled or ski equipped Vehicle disclosed and claimed by applicants in the instant application for patent.
U.S. Pat. No. 3,887,210 to Funke discloses a four wheeled, downhill racing cart with a steel frame and a driver's seat mounted on the frame for use on various surfaces. The rider of the cart must sit in an upright position with feet forward. The cart is steered by applying pressure with the feet to pedals attached to the front axle assembly. There is a braking mechanism which is triggered by leaning forward in the seat and engaging a braking member which is suspended from the seat frame. When the seat is leaned forward and the braking member is engaged, a plate is lowered to contact the ground surface and apply braking by frictionous contact with the ground. A rubber pad is fastened to the underside of the braking plate for braking engagement with the surface over which the cart is traveling. The cart does have handle bars, however, they are not used at all for steering control of the vehicle. The handles appear to be used for holding on and keeping the rider with the cart. The device also has carry hooks on the front handle assembly for towing of the device to the starting area. Additionally, the device can be fitted with a “roll-bar” attachment.
U.S. Pat. No. 4,098,519 to Reid, Jr. device looks most like the known “flexible flyer” type of snow sled. This wheeled sled has four wheels and may be ridden on a variety of surfaces in a sitting or prone position. The body of the device is not inclined and is composed of several, separate, wooden slats. There are slots in the body of the device for gripping when riding in a seated position. However, the prone position would be preferred in order for the user to operate the two hand brakes installed on the handle bars at the front of the device. The device is steered by way of crossed steering bars pivoted to each of the rear axle brace, front axle brace, and steering handle. The steering bars are connected diagonally to opposite positions on the front and rear axles such that the axle braces are pivoted in opposite directions as the steering handle is moved—this minimizes turning radius. Springs return the steering handle to a neutral, centered position when there is no pressure on the steering handle. The hand brakes act on the front wheels. This device does not have any sort of tow hook for pulling the sled to a starting position. There is no restraining device or harness on this, or any of the previously described sleds. There is also no “roll-bar” or any sort of plate or device to prevent injury or to keep the sled from tipping over.
U.S. Pat. No. Des. 331,031 to Janoff discloses a design for a land sled. Design patents cover only the look of the device depicted in the Figures and no real description of the device is included in a design patent. This particular land sled differs from the two previously described devices in several ways. It has two large roller type wheels, instead of four smaller wheels. It is capable of being steered by either the hands or feet and can be ridden sitting in an upright position (steering with the feet) or in a prone position (steering with the hands). The steering appears to be accomplished in a way similar to that of known “flexible flyer” type snow sleds—by pushing and/or pulling the large handle bar extending across the front of the device. There are also slots along the side of the sled, towards the back, for gripping when using the sled from a seated position. There does not appear to be any sort of incline to the main body of the sled, on which one would sit or lay prone, although it is difficult to determine much about the mechanics of a device from a design patent.
U.S. Pat. No. 5,354,081 to Huffman et. al. discloses a stunt-riding toy for use on a variety of surfaces including snow. The device may be fitted with four wheels, or skis. This vehicle has a seat and also must be operated from a sitting position, with the feet placed on plates near the front of the device. The device is quite narrow and is steered mainly by leaning in the direction it is desired to turn. The front foot plates also serve as a brake and a means to keep the vehicle from leaning too far and tipping over. If the vehicle leans too far, the plates will contact the ground surface, apply braking pressure and prevent further tipping. The device has two handles and a rear hand cable brake which pulls a plate into contact with the wheels when the hand brake is engaged. The handles are positioned near the rear of the device, close to the seat so that the rider's arms hang down along the rider's side to grip the handles, and keep the rider in an upright position.
The invention has the particular objectives, features and advantages of: 1) a steerable gravity driven vehicle; 2) that such vehicle is ridden in a prone, face forward position; 3) that such vehicle has at least one brake; 4) that such vehicle has a plurality of wheels, most preferably four (4) wheels however the sled having three (3) wheels—the single wheel preferably located between the legs of the driver—is also disclosed and is within the scope of the disclosure of the invention; 5) that such vehicle may alternatively have a combination of skis and wheels providing for enhanced performance for use on snow covered terrain; 6) that such vehicle may alternatively have at least one ski forward or in the front position of the vehicle and a slide pan toward the rear portion of the vehicle; 7) that such vehicle may alternatively have at least 3 skis, wherein either one ski is forward or in the front position of the vehicle or toward the rear portion of the vehicle; 8) that such vehicle as described in 1) though 7) above may have incorporated therein the mechanism for suspension of the wheels and/or skis which is configured to provide precise control in turns especially the carving of turns, by the skis, while descending on snow cover; and 9) that such vehicle as described in 1) through 4) above may be retrofitted with components in order to create the vehicle(s) described in 5), 6), 7) and 8) above.
The patents noted herein provide considerable information regarding the developments that have taken place in this field of non-motorized vehicle technology. Clearly the instant invention provides many advantages over the prior art inventions noted above. Again it is noted that none of the prior art meets the objects of the gravity driven vehicle in a manner like that of the instant invention. None of them is as effective and as efficient as the instant Gravity Driven Steerable Vehicle for maneuvering down steep, varied surface terrain and none of them are operated from the prone face down and face forward position.
SUMMARY OF THE INVENTION
The most fundamental objects and advantages of the invention are: 1) a steerable gravity driven vehicle; 2) that such vehicle is ridden in a prone, face down, face forward position; 3) that such vehicle has at least one brake; 4) that such vehicle has at least two wheels or skis/slide pan or a combination thereof; 5) that such vehicle has a steering suspension mechanism which provides for the carving, by the steerable skis, of precise turns on snow covered surfaces: and 6) a kit of components which are used to retrofit a wheeled vehicle to one with wheels, skis, pan or a combination of wheels, skis or pan.
It should be noted that where there are three (3) wheels on the vehicle, the third wheel may be located either at the front or the rear of the vehicle. The third wheel may be the same size as the other two wheels, or may be large or smaller. The third wheel may be independently steerable, or steerable in cooperation with the steering of the other two wheels.
The vehicle may have independent mechanical, air actuated or hydraulic actuated brakes and may have independent hydraulic shock absorbers on some or all wheels. But the vehicle need not have shock absorbers at all, or may have shock absorption only for the front wheels, for example. The vehicle also may have an attachment for the picking up of the vehicle by, for example, a ski chair lift, and which may be a part of the driver/operator restraint system acting to keep the operator's legs from drifting off of the vehicle especially in a sharp turn maneuver. The attachment for picking up the vehicle may further serve to protect the rider should the vehicle roll over. However, this attachment is not fundamental to the invention.
A primary object of the invention is to provide a gravity driven steerable vehicle comprising a chassis and a riding surface on which a rider is oriented in a prone, face down, face forward position, at least two wheels or skis or combination thereof, means for steering the vehicle, means for causing deceleration or halting of motion of the vehicle, and means for harnessing the rider onto and into the vehicle.
Another primary object of the invention is to provide means for steering each wheel independently.
A further primary object of the invention is to provide means for absorbing shock exerted on said vehicle caused by the vehicle passing over rough terrain.
Another object of the invention is to provide means for towing the vehicle to the top of an incline, and means for assisting the rider in staying on the vehicle and protecting the rider if the vehicle were to roll over.
Yet another object of the invention is to provide such a vehicle further comprising four wheels.
Another object of the invention is to provide such a vehicle having three wheels.
A still further object is to provide a safety brake which actuates upon release of the hand grips for operation and parking safety if a rider were to fall off of the vehicle during operation of the vehicle.
A yet still further object is to provide a means for automatically causing the vehicle to hold a constant turn which actuates upon the occasion if a rider were to fall off of the vehicle during operation of the vehicle.
A fundamental object of this invention is to provide a means or mechanism for suspension of the wheels and/or skis which means or mechanism is comprises a single a-arm pivotably attached to an axle at an axle pivot point and a shock absorber connecting end pivotably connected to one end a shock absorber and which shock absorber other end pivotably connected to said axle. The suspension system may be provided preferably independent for each wheel or ski or on only the front axle of the vehicle. The suspension system configured to provide precise control in turns especially the carving of turns, by the skis, while descending on snow covered terrain.
Another fundamental object of the invention is to provide a ski assembly having front end and a ski rear end, a ski running surface and a ski upward-facing surface and having a ski brake assembly configured to cause, when said brake assembly is operator actuated, a brake blade to extend below said ski running surface at said ski rear end thereby engaging the terrain surface upon which the ski is running. There may also be provided a brake return assembly preferably using springs to return said brake blade to a non-braking position.
These and further objects of the present invention will become apparent to those skilled in the art after a study of the present disclosure of the invention and with reference to the accompanying drawings which are a part hereof, wherein like numerals refer to like parts throughout, and in which:
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is a combination of a top plan view, a side plan view and a front plan view of the vehicle all of which are illustrating the body curvatures, the rider inclined riding surface/bed and the like;
FIG. 2 shows a top plan view of the vehicle, showing, in shadow the axle, steering, and wheel spindles;
FIG. 3 shows a top plan view of the three (3) wheeled embodiment of the vehicle;
FIG. 4 is a detail view of the assembly axle with an air/oil shock used in the wheel suspension;
FIG. 5 is a detail view of the assembly axle with a coil/oil shock used in the wheel suspension;
FIG. 6 is a detail view of the hydraulic rear wheel brake system;
FIG. 7 is a detail view showing the steering linkage in association with the prone steering position of the rider;
FIG. 8 is a detail view showing the right rear wheel spindle;
FIG. 9 is a detail view showing the right front wheel spindle;
FIG. 10 the two views illustrate detail of the tow-bar assembly which also is a part of the rider restraint system;
FIGS. 11A, 11 B and 11 C are a top plan view, and side plan view and a rear plan view respectively showing, in shadow, substantially all of the components and their relationship and which illustrates a wheeled vehicle retrofitted with skis on the front and wheels to the rear;
FIGS. 12A, 12 B and 12 C are a top plan view, and side plan view and a rear plan view respectively showing, in shadow, substantially all of the components and their relationship and which illustrates a wheeled vehicle retrofitted with skis on the front and skis on the rear;
FIGS. 13A, 13 B and 13 C are a top plan view, and side plan view and a rear plan view respectively showing, in shadow, substantially all of the components and their relationship and which illustrates a wheeled vehicle retrofitted with skis on the front and a slide pan to the rear which slide pan has grooves directed from front to rear which provide lateral stabilizing of the vehicle and which has a suspension system and a piston actuator which actuates braking by pressing the shovel/blade into the snow surface;
FIGS. 14A and 14B is a combined and sectioned drawing of a top plan view and a rear plan view respectively showing, in shadow, substantially all of the components and their relationship and which illustrates a braking system for a vehicle having wheels in the rear;
FIGS. 15A and 15B is a combined and sectioned drawing of a top plan view and a rear plan view respectively showing, in shadow, substantially all of the components and their relationship and which illustrates a braking system for a vehicle having wheels in the front;
FIGS. 16A and 16B is a top plan view and a rear plan view respectively which illustrates in the partial top plan view in shadow the front skis assembled to the front a-arm and also illustrating in shadow the steering linkage, the front brake system and the front suspension system and particularly in FIG. 16B is illustrated the “canting” of the skis;
FIG. 17 is a partial rear plan view of the attachment of a rear ski with brake components and showing, in shadow, the “unloaded” attitude of the ski and the relative positions of the suspension components and the fully loaded shock absorber compressed attitude of the ski and the relative positions of the suspension components;
FIG. 18 is a partial top plan view of the left rear ski attached to the rear axle illustrating the a-arm attachment to the ski post, the a-arm pivot point on the axle, the connection of the a-arm to the shock absorber which is attached to the axle at the shock absorber pivot location and also showing the brake blade, brake arm, brake cylinder;
FIG. 19 is a side plan view of the ski assembly of the invention, which shows, in shadow, the change in position of the brake components of the braking assembly; and
FIG. 19A is a top view of section AA which illustrates the detail of the brake return spring assembly.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following is a description of the preferred embodiment of the invention. It is clear that there may be variations in the size and the shape of the gravity driven wheeled vehicle, in the materials used in the construction and in the orientation of the components. Most importantly, the teaching of the wheeled version of the gravity driven vehicle is applicable to the version having skis or pans mounted in place of some or all of the wheels and which is used as a gravity driven vehicle on snow or ice covered downhill terrain. The stability in the absorbing of shock from uneven surface conditions and the stability and performance while making turns while going downhill derives from the combination of the steering and suspension geometry and the inherent shape of the skis mounted in place of the wheels and tires.
A. The Wheeled Gravity Driven Vehicle:
In order to most simply and clearly characterize the essential features of the invention reference is made to drawing FIGS. 1, 1 A, 1 B, 2 , 3 , 6 and 10 in which the essential elements of the invention are identified by numerals (not in a circle). FIGS. 4, 5 , 7 , 8 and 9 are details of various elements which are well known to the ordinary skilled artisan.
It is also important to note that the instant vehicle invention may have one wheel in front and one wheel in the rear. It is also possible to have three wheels with the single wheel either in the front or in the rear of the vehicle. Steering may be effected by using either the front wheel(s) or the rear wheel(s) or both. Braking combinations are likewise possible—front wheel, rear wheel or both.
With reference now to particularly FIGS. 1, 2 , 3 , 6 , 10 , 14 A, 14 B, 15 A and 15 B there is illustrated a four wheeled gravity driven steerable wheeled vehicle 10 . There is a chassis 12 having chassis front portion 12 A, chassis rear portion 12 B, chassis underside 12 C and chassis top side 12 D. A rider riding surface 14 is on chassis top side 12 D and is configured to cause a rider on rider riding surface 14 to be oriented in a prone, face down, face forward position. There is provided a means for attaching, 16 , a rear axle assembly 16 A substantially at chassis rear portion 12 B. There is also means for mounting, 18 , a front axle assembly 18 A substantially at chassis front portion 12 A.
Provided also is a means for steering, 20 , gravity driven steerable wheeled vehicle 10 or three-wheeled vehicle 40 by the rider when the rider is positioned on rider riding surface 14 . There are rear wheel hub and spindle assemblies 22 integral with rear axle assembly 16 A. Wheels and tires 23 are normally mounted to the wheel hub. Front wheel hub and spindle assemblies 24 are integral with front axle assembly 18 A.
A braking system or means for causing deceleration and halting of motion 26 of vehicle 10 when vehicle 10 (or 40 ) has motion is provided. Braking system 26 may be hydraulic, mechanical or a combination of the two and braking may be of all wheels or some of the wheels.
In order to help the rider stay on vehicle 10 or 40 , there is a means for harnessing 28 the rider onto and into rider riding surface 14 when the rider is positioned on the vehicle. To provide additional comfort for the rider and to improve the stability of the vehicle while moving, there may be provided means for absorbing shock 20 exerted on each of the front wheels and tires 23 attached to each of the two front wheel hub and spindle assemblies 24 thereby damping shock caused by vehicle 10 passing over rough terrain, between front wheels and tires 23 and front axle assembly 18 A. There may also be means for absorbing shock 32 exerted on each of the rear wheels and tires 23 attached to each of the two rear wheel hub and spindle assemblies 22 thereby further damping shock.
In order to get wheeled vehicle 10 or 40 or ski equipped vehicle 10 A or 40 A up a ski slope for example, there is provided a combination rear roll bar and transport bail 34 . When the rider is on the vehicle, bar 34 is in the lowered position providing the rider with a roll bar and an object against which pressure may be applied when the rider is in a sharp turn. Bar 34 is placed in a second position which permits attachment to a lift such as a ski lift.
In order to discuss some of the engineering features, reference is again made to the drawings including FIGS. 4-19. The drawings show simply the preferred embodiments of the wheeled and the ski equipped vehicle which have the following preferred specifications:
FIG. 1 shows a top, side, and front plan view of the vehicle, illustrating the body curvatures, the rider inclined riding surface/bed including the 11″ diameter high speed pneumatic, tubeless tires in the preferred embodiment of the vehicle, which are designed for motor vehicle racing at speeds in excess of 100 mph and which provide excellent traction and a soft but firm ride.
Advanced four wheel “A” arm air spring, oil damped suspension—independent four wheel suspension with air/oil shocks or with coil/oil shocks is provided and yields a smooth, stable ride over surfaces with irregularities ranging from wash board to large bumps. However, not all four wheels need have suspension, possibly only the front wheels might have suspension. Also, the vehicle could be made in either a four-wheeled or three wheeled embodiment. In either embodiment, the suspension is not essential. FIG. 3 illustrates a three (3) wheeled embodiment of the vehicle. FIG. 4 shows a detail view of the assembly axle with an air/oil shock used in the wheel suspension, and FIG. 5 shows a detail view of the assembly axle with a coil/oil shock used in the wheel suspension.
Independent hydraulic braking is provided from dual, real wheel, hydraulic disk brakes, designed for motor vehicle racing at speeds to 150 mph and operated with a single hand lever. These brakes give smooth, uniform and powerful braking capability whether with a four or three-wheeled embodiment. The braking system could be modified for a three-wheeled embodiment. FIG. 6 is a detail view of the hydraulic rear wheel brake system.
For the detail of the braking system used with the ski equipped version of the vehicles 10 A or 40 A, reference is made to FIGS. 16-19. Particularly, FIGS. 16A and 16B illustrates in the partial top plan view in shadow front skis 70 A assembled to the front a-arm 32 A and also illustrating in shadow the steering linkage, the front brake system 80 including brake return system 88 and the front suspension system 30 and particularly in FIG. 16B is illustrated the “canting” of the skis 70 A;
FIG. 17 shows the attachment of a rear ski assembly 70 A i.e, the ski assembly having ski brake assembly 80 as a part of ski assembly 70 and also shows, in shadow, the “unloaded” attitude of ski assembly 70 A and the relative positions of the suspension components and the fully loaded shock absorber 32 B compressed attitude of the ski and the relative positions of the suspension components, i.e., a-arm 32 A and the piston of absorber 32 B;
FIG. 18 shows a left rear ski 70 A attached to means for absorbing shock 32 which is attached to the rear axle 31 , the manner of the a-arm 32 A attachment to the ski post 72 , the a-arm pivot point 32 A 3 on the axle 31 , the connection of the a-arm shock attachment end 32 A 2 to the shock absorber end 32 B 1 which shock absorber is attached to the axle at the shock absorber pivot location 32 B 2 and also showing the brake blade 84 , brake arm 82 , and the brake cylinder 81 . FIG. 19 is a view of the ski assembly 70 A of the invention, which shows, in shadow, the change in position of the brake components of the braking assembly 80 . FIG. 19A is a top view of section AA which illustrates the detail of the brake return spring assembly 88 along with return springs 88 A.
There is provided a combination rear roll bar and transport bail. This bar is hinged so that locked in the folded down position, it tends to confine the legs of the rider and further resists overturning of the vehicle. When this bar is in the unfolded or up position it is useful as a tow or lift bar which may be attachable to a ski lift as an example of use. However, it is possible to have an embodiment of the vehicle without this feature. FIG. 10 illustrates detail of the tow-bar assembly which also is a part of the rider restraint system.
The prone (lying down) low center of gravity design provides control and good visibility. It is also possible that this low position may add to the level of safety for the rider. The extremely low center of gravity provides a relatively stable and safe ride—overturning is nearly impossible.
There is provided a safety harness which enhances control, stability and rider safety, and which is shown illustrated in FIGS. 2 and 3. The shoulder harness provides rider stability and contributes to rider safety by keeping the rider in place on the vehicle.
There is also an automatic brake which actuates upon release of the hand grips for operation and parking safety. This feature is not essential to the basic embodiment of the invention, however this is an important additional feature. With this safety braking mechanism, the vehicle will be stopped if the rider were to fall off of the vehicle at some point during the operation of the vehicle. Additional to the automatic brake system there may also be a means for causing the vehicle to go into a constant tight turn mode of operation if the rider loses control or if the rider fall from the vehicle while in motion.
The surface of the vehicle on which the rider lays is comprised of a closed cell body pad for rider comfort. There is an elevated chest rest and thick foam mat which provide additional rider comfort and visibility.
In the preferred embodiment, the body and chassis of the vehicle is made from light weight foam core fiberglass reinforced construction. The strong, rigid, impact resistant foam filled fiberglass body with aluminum inserts provides a single framework for attachment of all components. Fiberglass body, plated steel parts, and extensive use of aluminum provide optimum protection from the elements, and from impact damage.
The steering and braking mechanism is a ball bearing bicycle style steering and braking assembly which is positive, responsive and familiar to all to control, thus making learning to ride, and riding the vehicle easier and more comfortable. FIGS. 7 and 15A provide, in combination a detail view showing the prone steering linkage. Substantially the same steering system as shown is FIGS. 7 and 15A is also used in the ski equipped vehicles as shown in FIGS. 11A, 12 A, 13 A and 16 A.
There are provided precision bearings on all four axles in one embodiment. Independent rear axles provide maximum maneuverability in a four wheeled embodiment. The vehicle may be provided with precision wheel hubs, with pre-lubricated ball bearings, which are maintenance free. In a preferred embodiment the suspension and steering spindle bearings are formed of woven TEFLON or NOMEX and are designed to withstand high impact forces and hostile environments, and provide long life with no maintenance. FIG. 2 shows a top, side, and front plan view of the vehicle showing, in shadow, the axle, steering, and wheel spindles. Also, FIGS. 8 and 9 show a detail view showing the right rear wheel spindle and a detail view showing the right front wheel spindle.
The preferred steering post ball bearings and linkage ball rod ends provide maintenance free, smooth, zero back lash response. Each vehicle may be provided with elastomer bumper strips in the front and the rear which provide impact protection for the vehicle and rider. The preferred steering post, wheel, and front and rear axle assemblies can be removed intact should maintenance be required, thus reducing time and cost of any necessary maintenance.
In a preferred embodiment, the vehicle chassis has a ramp-shaped underbody and detachable covers which offer protection for axles, steering linkage, and suspension from road obstacles. Each vehicle in the preferred embodiments has strong, impact resistant fiberglass fenders which protect the rider from track dirt and contact with the wheels or skis when riding.
Following is a general description of the many technical features and the advantages achieved by the presently disclosed invention. It is material provided to further enhance the level of disclosure and present all of the presently known advantages achieved because of the technical features of the invention.
General Discussion:
A. The Gravity Driven Vehicle with Skis or Combination of Skis and Wheels or Slide Pan
While much of the following description is presented as a description of a wheeled vehicle similar to the vehicle of the present invention as described above but which has been retrofitted or specially constructed to result in the vehicle for use on snow covered terrain. It is important to note that the vehicle basically as described above but modified for use on snow may be custom made rather than created from a wheeled version by means for retrofitting the wheeled version. All of the disclosure above is applicable to the disclosure of the ski version of the vehicle except of course that portion which relates to the specifics of the braking system and some aspects of the steering systems.
1. Retro Fit Kits/Ski Version
The retrofit kit is used in conjunction with the gravity driven wheeled vehicle of the present invention or other like products to make the product easily adaptable for use in snow covered conditions. The details of the systems described below apply as a retrofit package or basically describe the components and the function when applied to a gravity driven vehicle custom designed and dedicated for use only on snow. I.e., a wheeled vehicle may be retrofitted with the combination of skis or slide pans or custom designed and built in the same manner. FIGS. 11-13 and 16 illustrate the vehicle with skis in the front and wheels to the rear, skis both front and rear, and skis in front and a slide pan with braking to the rear respectively. It should further be noted that the use of skis and slide pan or slide pans is interchangeable in that they both provide the sliding surface upon which the vehicle rides when in descent on a snow covered surface. A slide pan or ski may be used in any combination in the front in the rear or both front and rear locations of the vehicle.
Front Steering System—FIGS. 11-13 and 16
A unique discovery during the course of the development efforts to create the winter or snow covered terrain version of the gravity driven vehicle occurred in the integration of the skis onto the existing single swing arm suspension design of the wheeled product. As a consequence of the advanced four wheel “A” arm air spring, oil damped suspension—independent four wheel suspension with air/oil shocks or with coil/oil shocks as illustrated in at least FIGS. 4, 5 , and the multiple views of FIGS. 11-16 there achieved a smooth, stable ride over surfaces with irregularities ranging from wash board to large bumps. With the mounting of skiis to the A-arm or the wishbone portion of the suspension system, the position or attitude of the outer edge of all skis due to the single arm geometry when there is no rider on the sled and the shocks are operating properly, causes the outer edge of all skis to be constantly engaged with the ground or snow surface. When the sled is being ridden the loading of the shocks, depending on how they are set, causes the skis to change to a more flat or level attitude relative to the snow or to the ground surface. This attitude only reaches a substantially flat attitude if there is extreme loading on the sled body and does so to absorb shock to the sled and rider. After such levels of loading and impulse types of shocks to the sled, the sled always returns to the outer edge engagement posture. Substantially because of this characteristic of ski attitude or the inward canting of the skis when the sled is being ridden, on a modest downhill terrain put in particular when travelling on steeper downhill and upon initiation of turns, the lower or downhill ski becomes more heavily loaded tending to increase the flatness orientation relative to the snow surface yet still resulting in the outer edge carving into the snow. I.e., the outer edge of the ski carves into the snow and as it becomes increasingly loaded the suspension slightly counters the digging or carving action but continues to engage the snow surface. The upper ski or uphill ski, particularly the outer edge, with the lesser loading while in the turn it is still partially canted inwardly, carves as well and even more aggressively because of this canted attitude of the uphill ski in the turn. Alternatively described, the uphill ski acts somewhat as an anchor as this engagement becomes more unloaded in an aggressive turn, the a-arm extends its full travel maintains constant engagement with the snow due to the fact the lower or downhill ski is flattening allowing the attitude of the uphill ski to remain in constant contact with the snow. This unexpected performance characteristic or functionality provides benefits such as for example: the carving action of both skis constantly counterbalancing each other provides tremendous control and maneuverability in virtually every snow condition; and under conditions of heavy loading of the downhill ski, the digging and tipping tendency of the sled is reduced dramatically. To provide further control and maneuverability a keel component may be added to the ski bottoms.
A. The front ski retrofit is attached to the existing front a-arm (wishbone) assembly of the wheeled version with either a double or the single arm/linkage geometry by utilizing the existing fastening system. When fixed to the suspension linkage the ski has the ability to pivot from an axis perpendicular to the axle allowing the tip and heal to pivot in opposition to one another, upwards and downwards and is limited in its pivot by a stop mechanisms mounted to either the ski or the mounting system. The width and length of the selected skis and the forward or rearward positioning of the pivot point is established based upon the terrain and the specific performance requirements desired. The steering geometry has been designed to create a carving action when the skis are turned by the steering linkage. I.e., upon causing a turn using the steering mechanism both ski tips rise slightly, the tails sink slightly and the inner edge of the ski opposite of the direction of the turn and the outer edge of the ski in the direction of the turn tilt slightly downwards into the snow or ice surfaces. These edges can also be described as the ski edges on the inner radius of the turn.
Brake System—FIGS. 13, 16 - 19
B. The independently or simultaneously actuated right and left, rear, front or rear and front, or independent rear and front combined brakes or single brake actuation unit whether one or divided mechanism is integrated in to the front ski and trailing or sliding pan or ski assemblies that are part of the vehicle/mountain sled retrofit package. The actuation of the mountain sled brake is either mechanical, hydraulic, servo-mechanical, pneumatic or a combination of these technologies. When this solution is used as a retrofit it is intended, whenever and wherever possible, that the existing actuation system or systems be utilized.
Rear Tracking and Control System—FIG. 13
C. The rear brake system or systems is/are integrated into an under body pan covering a portion or all of the sled under body from approximately the middle of the sled length and some distance forward of the rear axle location mounting surfaces and is attached or nearly meets the sled underside and extends sufficiently across the width of the sled in the front in a fixed or in a limited manner with a hinge or slide like interface allowing the pan from the hinge point rearwards to move up and down or to slide or flatten out across the under face of the sled a distance equal to the translated stroke distance of an internally mounted shock system. The pan will be a complete cover with a downward sloping straight or radiused lead edge, running from the mounted or hinged or meeting leading edge and transitioning to a gliding surface that runs almost parallel to the underside of the body or sled frame. The rear pan or ski assemblies will be covering a single or double shock absorption mechanism able to operate independent of or together with each other and the braking mechanism that will be substantially a swing arm or linearly actuated arm or blade that will when actuated protrude out from the pan or ski below their running surfaces and into the snow or ice surface at a positive, negative or right angle to the pan or running surface and will be depth adjustable equal to the geometry and stroke of the actuation. This pan or ski (if chosen) as seen from behind is profiled to provide maximum lateral grip and stability when either turning or gliding. The geometries are optimized to address snow condition and terrain.
Benefits
D. Commercial: The winter retrofit package allows an owner of a summer mountain sled the simplified and flexible solution of utilizing at a minimum a sled body with an integral frame or a sled body with a separate frame. Additionally, depending upon the components of the winter retrofit package, many more of the basic of summer mountain sled components can be used in retrofitting the summer sled for winter recreation such as the axle, suspension, steering and braking systems.
E. Technical: The retrofitted summer sled steering, braking, and rear tracking and control systems provide in the sled retrofitted for winter use all of the already known benefits of summer/wheeled sled including superior control and stability for a snow sledding experience.
2. Alternative Ski Version—Studded Tires
The condition of downhill ice packed or ice covered roadways, trails, paths, etc. presents a braking, steering and control challenge for both a conventional summer mountain sled and a winter mountain sled of any form or configuration. The operational challenge is to provide a sled with a steering and braking solution that handles these conditions. The following embodiment of the invention and declared benefits address this challenge.
A mountain sled equipped with four wheel or three wheel independent or simultaneous braking systems will have its standard tires replaced with slick or profiled tires that have been retrofitted or produced to order with studs, nails, screws, etc. fixed to, inserted into or imbedded in the rolling surface of the tire and protruding from the rolling face of the tire sufficiently to provide contact and grip in the existing ice or ice packed condition on the running surface. The selection of each tire profile and cleat material, cleat geometry and cleat placement and number of cleats is dependent solely on the application surface and can be changed and optimized accordingly to best suit the exact requirements of each downhill surface.
Benefits Alternative Ski Version—Studded Tire Version
This solution has the distinct benefit of providing exceptional control on most every downhill ice covered or ice packed roadway, trail, path, etc. running surface.
I. Due to the fact that only the tires used for summer sport are replaced with tires having studs or nails (or the like) mounted to the tread portion of the tire to provide improved friction interface between the sled and the running surface. All other subsystems, steering, suspension and braking remain the same for the studded tire version as for the summer tire version. The resulting sled has substantially all of the performance advantages of the summer wheeled vehicle.
I Double Arm Independent Suspension (Upper and Lower Control Arm Design)
The challenge of providing superior handling and control of a gravity driven mountain sled is to offer the best technology to achieve differing optimized operating results to meet the demands of the conditions and requirements of various terrains. The integration of certain solutions in a mountain sled with tires or with winter attachments such as in various presented solutions is primarily possible due to the combination of certain existing technologies, materials and compact componentry and by integrating them into various suspension geometries. The advent of small components coming from the mountain bike industry, has permitted mountain sledding to move from being basically unsophisticated toys to sophisticated sports equipment.
Integrated into the mountain sled is a suspension system that displays when viewed from the side (from sled rear to front or front to rear) a suspension geometry that is trapezoidal in form (parallelogram) with all four joints forming pivots and the two sled side, upper and lower fastening points/pivots are fixed in some manner firmly to the sled frame or uni-body or axle system or combination thereof and the spindle or the ski assembly or ski pan assembly is fixed somewhere on the fixed member connecting the outboard pivot points of the trapezoid. As part of this design and resisting loading of the trapezoidal design is an arm that extends at an angle away from one of the inboard trapezoid pivot locations and is an integral mechanical arm to which a shock absorber is attached to the end of arm and to a fixed point on the body, frame or axle system and both ends of the shock absorber can pivot. This geometry allows the upright mounting face for the spindle or ski or pan to move the spindle or ski or snow pan assembly upward and downward when the sled is pointed straight forward and when the sled itself has certain load exerted and released such that the tire, ski or pan maintains complete contact of its lower running surface with the operating surface, the running surface remains parallel with itself as it is loaded and unloaded. The longitudinal motion of the entire assembly is limited by the stroke of the shock absorber and the operating envelope of the related mechanics. This design permits minimal axial motion of the contact running surface as it is loaded and unloaded called scrubbing. This scrubbing action is considerably less than that witnessed by the solution already presented in the claim from TSI with a single arm solution.
Benefits
This solution gives the clear benefits of
II. Maintaining constant and maximum contact of the entire running face of the tire, ski, and pan solutions with the running surface.
III. Reduces scrubbing and non-uniform wear of the running surfaces of the tires, skis and pans.
IV. Simplifies steering geometry compound angles allowing maximization of ski contact and carving benefits. This system is highly recommended for applications utilizing skis and sliding pan systems.
II Integrated Body & Frame Solution
The body design and construction for the instant vehicle represents the latest form of taking the idea of monocoque or body integral frames and eliminating the need for conventional frames and separate bodies for use in mountain sled, sleds and sled product applications. This idea utilizes the fiberglass upper and lower body components known as or halves and sandwiches them together and imbeds inserts to add strength, to bond the halves, to stiffen the body and to take maximum advantage of the collective strength of each system. This solution accommodates and allows the fiberglass to be a connecting structure through the use of adhesives and epoxies that are part of the normal fiber-glassing process of dissimilar materials. This permits the combination of a variety of materials that would not otherwise be combined in a conventional fame/body construction. The imbedded materials then are optimized for their ability to retain fasteners, to choose material that accommodates extreme variations in temperature, adequately spread load across the fiberglass surface and eliminating extra material where it is unnecessary.
Benefits
The benefits from such a solution are;
I. Provides singular body and frame system, simplifying assembly, inventory and repair.
II. Makes maximum use of the strength and stiffness of each system.
III. Allow adaptability and design modifications when new materials come available without requiring the whole design be changed.
There are additional subsystems which may be incorporated into the gravity driven vehicle of each of the embodiments described such as for example:
Rollover protection
Steering damping
Accessories such as headlights, speedometer
Adjustable steering ratios
Prone sled body angle support system
Complete braking system i.e., one system for the front and one for the rear which may use two (2) independent master cylinders and brake circuits.
Detail Relative to the Suspension System, the Ski Assembly and The Braking System
Suspension geometry action and performance contribution to tracking and steering control: The existing, previously disclosed single A-arm suspension geometry provides the ability to present the outer edge of four skis, when mounted to a two opposing arm axle assemblies, to the snow at an angle to the running surface which delivers significant unique, maneuvering and steering control performance in most all snow conditions. This performance results from the fact that a carving geometry of the skis to the snow occurs. This engagement with the running surface is equally as consistent improves as the sled is underway and is caused to turn through the steering linkage. In a turn or as one is traversing a downhill slope the outboard or downhill ski receives increased load and the ski engages more with the snow/ice running surface until such time that the load on this ski begins to overcome the resisting force of the shock attached to the shock anchor point on the A-arm and the axle. As the resisting force (ajustable) is gradually overcome the A-arm begins to pivot at the A-arm pivot and ski assembly begins to move toward a flatter orientation with the snow. This action helps to avoid over powering the engagement of the downhill ski downhill edge and helping to avoid overturning. Simultaneously, the uphill ski is less loaded but still has its outer edge engaged in the snow and creates a scrapping action on the adjacent downhill snow/ice as well as packing what ever loose snow is present under the underside of the ski. This uphill ski performance improves as the downhill ski continues to flatten in respect to the running surface and loading. Additionally, the underside of any and all skis can be equipped with various geometry keels to assist in linear or turn tracking of all skis as they, under suspension applied compressive loads, present more ski surface and the keels to the running surface. There are always limits to this performance resulting from excessive speed and surface conditions, etc.
Ski Pivot Action and Performance Contribution:
The Ski foot and post pivot allows any ski when traveling over uneven surfaces to follow the terrain contour more closely. The swing motion allowed by this feature is limited by the presence of bumpers mounted on the ski foot which contact ski post extensions when pivot travel limits are reached. This function delivers another benefit because of the ability to allow the ski to follow the terrain more closely that being it causes the brake mounted on the attached ski assembly to achieve more consistent contact with running surface.
Braking Alternative A: Brake Action and Performance Contribution:
The brake assembly developed by the applicants provides superior braking action in various snow and ice conditions. The brake assembly has a hydraulic piston actuated lever equipped with a brake blade. This brake is actuated through the introduction of hydraulic pressure into the input port, the pressure causes the piston shaft to extend from the cylinder in the direction of the rear of the ski, the shaft is attached to the brake lever which begins to pivot at the brake lever pivot and rotates the lever with the attached blade toward the running surface until such point that the full stroke piston and the lever has been reached. The developed solution looked to achieve maximum force, with limited space by using a short stroke cylinder and applying multiple ratio motion at the brake tip. Currently, the solution developed provides practically two inches of travel at the brake tip. The solution utilizes external extension springs to assist the brake return when no longer under hydraulic pressure. The solution is further supported by the presence of an expansion tank mounted to and on the non-pressure side of the brake actuation cylinder. The expansion cylinder is partially filled with the same fluid used to actuate the piston and then securely plugged. This expansion tank provides three benefits, closed system that does not allow air to enter the non-pressurized side of the system and contaminate the pressurized side of the system if air were to get by the piston seals, this non-pressurized side of the system could be used to introduce opposing pressure by filling it with more fluid and when compared with an open ended system where an air vent is present to relieve pressure this solution eliminates the likelihood of drawing contaminants such as water into the cylinder or by the piston seals into the pressurized fluid side of the system.
Braking Alternative B: Brake Action and Performance Contribution:
The brake assembly developed by the applicants provides superior braking action in various snow and ice conditions. The brake assembly depicted in print number(s) ______ shows a hydraulic piston actuated lever equipped with a brake blade. This brake is actuated through the introduction of hydraulic pressure into the input port, the pressure causes the piston shaft to retract extend from the fully extended position away from the rear end of the ski, the shaft is attached to the brake lever which begins to pivot at the brake lever pivot and rotates the lever with the attached blade upwards away from and out of the running surface until such point that the full stroke piston and the lever has been fully retracted. The developed solution looked to achieve maximum force, with limited space by using a short stroke cylinder and applying multiple ratio motion at the brake tip. Currently, the solution developed provides practically two inches of travel at the brake tip. The solution utilizes external extension springs to assist the brake return when no longer under hydraulic pressure. The solution is further supported by the presence of an expansion tank mounted to and on the non-pressure side of the brake actuation cylinder. The expansion cylinder is partially filled with the same fluid used to actuate the piston and then securely plugged. This expansion tank provides three benefits, closed system that does not allow air to enter the non-pressurized side of the system and contaminate the pressurized side of the system if air were to get by the piston seals, this non-pressurized side of the system could be used to introduce opposing pressure by filling it with more fluid and when compared with an open ended system where an air vent is present to relieve pressure this solution eliminates the likelihood of drawing contaminants such as water into the cylinder or by the piston seals into the pressurized fluid side of the system.
The gap between the rear end of the ski and the brake blade is critical. The development of this ski brake determined that when braking, the disturbed running surface, snow, ice, etc. needs to find a place to release the braking loads and if this release location is readily available between the blade and the ski it will escape at that point, evidenced through the plume, rooster tail that gets larger the larger the gap and the higher the speed. Conversely, when the gap is reduced to a minimum the loads, forces, energy is then captured under the ski and greatly increases brake drag and brake performance.
While these additional subsystems are not being described in detail herein, it is certainly within the skill of the ordinary artisan in the field of mechanics and mechanical design to understand and implement many types of mechanisms or systems addressing the incorporation of any or all of the above subsystems into any one of the vehicles as described as the instant invention.
It is thought that the present gravity driven steerable vehicle, for use in riding or racing primarily down hill over varied terrain, and many of its attendant advantages is understood from the foregoing description and it will be apparent that various changes may be made in the form, construction and arrangement of the parts thereof without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the form hereinbefore described being merely a preferred or exemplary embodiment thereof.
Elements of the Invention
10 A four wheeled gravity driven steerable vehicle
10 A A four ski equipped gravity driven steerable vehicle
12 a chassis having
12 A chassis front portion,
12 B chassis rear portion,
12 C chassis underside and
12 D chassis top side;
14 a rider riding surface on said chassis top side 12 D configured to cause a rider to said ride riding surface 14 to be oriented in a prone, face down, face forward position;
16 means for attaching a rear axle assembly 16 A substantially at said chassis rear portion 12 B;
16 A a rear axle assembly
18 means for mounting a front axle assembly 18 A substantially at said chassis front portion 12 A;
18 A a front axle assembly
20 means for steering said gravity driven steerable wheeled vehicle 10 by said rider when said rider is positioned on said rider riding surface 14 ;
22 rear wheel hub and spindle assemblies integral with said rear axle assembly 16 A;
23 wheels and tires
24 front wheel hub and spindle assemblies integral with said front axle assembly 18 A.
26 braking system or means for causing deceleration and haulting of motion of said vehicle 10 when said vehicle has motion.
28 means for harnessing the rider onto and into said rider riding surface 14 when said rider is positioned on said vehicle 10
30 means for absorbing shock exerted on each said front wheels and tires 23 attached to each said two front wheel hub and spindle assemblies 24 thereby damping shock caused by said vehicle 10 passing over rough terrain, between said front wheels and tires 23 and said front axle assembly 18 A;
32 means for absorbing shock exerted on each said rear wheels and tires 23 attached to each said two rear wheel hub and spindle assemblies 22 thereby damping shock caused by said vehicle 10 passing over rough terrain, between said rear wheels and tires 23 and said rear axle assembly 16 A;
31 axle component
32 A a-arm
32 A 1 wheel and ski assembly attachment end
32 A 2 Shock absorber pivotal attachment end
32 A 3 a-arm pivot attached to axle 31
32 B shock absorber
32 B 1 shock absorber a-arm end
32 B 2 shock absorber axle pivotable attachment end
34 combination rear roll bar and transport bail
40 A three wheeled gravity driven steerable wheeled vehicle
40 A A gravity driven steeable vehicle with two skis in front and two wheels in the rear
70 ski assembly without ski braking assembly for attaching to a-arm
71 ski front end
71 A ski rear end/tail,
71 B ski running surface and
71 C ski upward-facing surface
72 ski post
74 ski foot
76 ski pivot
70 A ski assembly with ski braking assembly
80 ski braking assembly
84 brake blade
84 A gap between brake blade and ski rear end
82 brake arm
83 brake arm pivot
81 brake cylinder
85 brake cylinder mounting and pivot bracket
85 A brake cylinder pivot
86 sealed brake cylinder reservoir
88 brake return assembly
88 A brake return springs
88 B | A gravity driven steerable vehicle having wheels, or skis or a combination of wheels and skis for recreational use, most particularly on surfaces such as pavement, artificial hard-pack turf, mountain slopes, dirt roads, grass and hard-packed or non-packed snow. The vehicle has at least three (3) but preferably four (4) wheels, or skis or a combination of wheels and skis which may or may not be on independent axles one from the other and which may or may not be each independently shock suspended. There is also a steering mechanism for steering the vehicle and a driver compartment portion for containing a driver of the vehicle in a prone face-down and face-forward position. The vehicle is steerable by the driver from the prone face-down and face-forward position. The mechanism for suspension of the wheels and/or skis is configured to provide precise control in turns especially the carving of turns, by the skis, while descending on snow covered terrain. The attitude of the skis relative to the snow surface changes upon initiation of a turn and while in the turn to increase the edgeing of the skis thereby enhancing the turning characteristics of the vehicle. The vehicle may further have a braking system for slowing or stopping the vehicle and a harness apparatus for harnessing the driver onto and into the vehicle. | big_patent |
RELATED APPLICATION
This application claims the benefit of U.S. Provisional Application No. 60/474,861, filed May 30, 2003, entitled, “Radial Reflection Diffraction Tomography,” which is incorporated herein by this reference.
The United States Government has rights in this invention pursuant to Contract No. W-7405-ENG-48 between the United States Department of Energy and the University of California for the operation of Lawrence Livermore National Laboratory.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates in general to imaging, and more particularly to an imaging method and apparatus employing Radial Reflection Diffraction Tomography.
2. Description of Related Art
Intravascular ultrasound (IVUS) imaging provides a method for imaging the interior of blood vessel walls. In standard acoustical techniques, a catheter with a rotating ultrasound transducer is inserted into a blood vessel. The transducer launches a pulse and collects the reflected signals from the surrounding tissue. Conventional ultrasonic imaging systems use B-mode tomography or B-scans, wherein images are formed from the envelope of the received display echoes returning to an ultrasonic transducer as brightness levels proportional to the echo amplitude and by assuming straight ray theory (i.e., geometrical optics). The brightness levels can then be used to create cross-sectional images of the object in the plane perpendicular to the transducer image. However, such images typically suffer from the consequences of ray theory of sound propagation, which does not model its wave nature.
A circumferential scan can be made by either rotating a single transducer (mechanical beam steering) or by phasing an array of transducers around a circumference (electronic beam forming). Typically, one ultrasound pulse is transmitted and all echoes from the surface to the deepest range are recorded before the ultrasound beam moves on to the next scan line position where pulse transmission and echo recording are repeated. When utilizing B-scan, the vertical position, which provides depth of each bright dot is determined by the time delay from pulse transmission to return of the corresponding echo, and the horizontal position by the location of the receiving transducer element.
Although B-scan IVUS images can be utilized to detect plaque and characterize its volume, the classification of plaque types by ultrasound is very difficult. Conventional B-scan images utilizes scattering, which, in turn, depends on the acoustic impedance dissimilarity of tissue types and structures. Although hard calcifications in some plaque can be detected using such a mismatch, the similarity in the acoustic properties of fibrous plaque and lipid pools prevents direct identification. Consequently, the size of the fibrous cap cannot be accurately estimated.
Diffraction tomography has additionally been applied to medical imaging problems for a number of years, usually in a standard circumferential through transmission mode. Furthermore, improved vascular images have been provided by utilizing time domain diffraction tomography, a technique capable of accounting for the wave propagation of the transmitted acoustic waves in addition to redundant information from multiple angular views of the objects imaged. A related B-mode approach that incorporates spatial compounding has also been employed to provide improved vascular images through multiple look angles.
Background information on rotational IVUS systems are described, for example, in U.S. Pat. No. 6,221,015 to Yock. Background information on phased-array IVUS systems are described, for example, in U.S. Pat. No. 6,283,920 to Eberle et al., as well as U.S. Pat. No. 6,283,921 to Nix et al. Multi-functional devices have been proposed in other areas of vascular intervention. For example, U.S. Pat. No. 5,906,580 to Kline-Schoder et al., describes an ultrasound transducer array that may transmit signals at multiple frequencies and may be used for both ultrasound imaging and ultrasound therapy. Therapeutic ultrasound catheters, are described, for example, in U.S. Pat. No. 5,725,494 to Brisken et al. and U.S. Pat. No. 5,581,144 to Corl et al., which describes another ultrasound transducer array that is capable of operating at multiple frequencies. However, none of the above devices and associated techniques from the above cited patents, are suited for rapid identification of objects, such as, but not limited to, vulnerable plaque or objects recessed in a bore hole, in accordance with the principles of the present invention.
SUMMARY OF THE INVENTION
The present invention is directed to a wave-based imaging method, which includes: directing predetermined energy waves radially outward from within an interspace and receiving scattered energy waves from one or more objects. The received data are processed to produce images of the objects, wherein the processing includes application of a wave-based algorithm that can map an angular location and a plurality of frequency parameters of the received scattered energy waves to construct images of the one or more objects.
Another aspect of the present invention is directed to a wave-based imaging method that can be utilized to characterize a plaque, which includes: inserting a catheter having a longitudinal axis and a distal end into an artery, wherein the catheter further includes a single transmitter disposed about the distal end of the catheter and a receiver aperture having a plurality of receivers additionally disposed about the distal end of the catheter, wherein the transmitter and the receiver aperture is capable of rotating up to 360 degrees about the longitudinal axis of the catheter. As part of the method, one or more predetermined energy waves are directed radially outward from the single transmitter and radial scattered energy waves are received in a predetermined imaging mode by the receiver aperture. The received scattered energy waves results in collected data capable of being processed to produce images of plaque from the surrounding artery walls, wherein the processing includes application of a wave-based algorithm that can map an angular location and a plurality of frequency parameters of the received scattered energy waves to construct the images and determine the risk of rupture and/or thrombosis.
Another aspect of the present invention is directed to a wave-based imaging method that can be utilized to characterize a plaque, which includes: inserting a catheter into an artery, directing one or more predetermined energy waves radially outward and receiving one or more radial scattered energy waves from a distal end of the catheter; collecting a radial scattered tomographic data baseline of the artery's tissue; measuring an applied external pressure to the artery; obtaining a deformation radial scattered tomographic data set of the artery's tissue after application of the external pressure; and processing the radial scattered tomographic data baseline and the deformation radial scattered tomographic data set to produce a final image indicating elasticity of the artery to characterize the imaged plaque, wherein the processing includes application of a wave-based algorithm that can map an angular location and a plurality of frequency parameters of the received scattered energy waves.
A further aspect of the present invention is directed to a wave-based imaging apparatus, which includes a flexible substrate having a longitudinal axis and a distal region and one or more elements disposed on the distal region and capable of directing one or more predetermined energy waves radially outward and receiving one or more radial scattered energy waves from one or more objects. The received scattered energy waves are capable of producing images of one or more objects by processing a collected data set, wherein the processing includes application of a wave-based algorithm that can map an angular location and a plurality of frequency parameters of the received scattered energy waves.
A final aspect of the present invention is directed to a wave-based imaging apparatus that includes a Hilbert space inverse wave (HSIW) algorithm that can map an angular location and a plurality of frequency parameters of said received reflected diffracted energy waves so as to characterize plaque within a living vessel.
Accordingly, the present system and method employs desired Radial Reflection Diffraction Tomographic techniques to determine the state and location of buried wastes, to track plumes of underground contaminants of materials, to determine the state of materials residing in waste drum barrels or weapons, to evaluate nondestructively parts having existing access holes (e.g., automobile parts), and for identifying potentially life threatening vulnerable plaque buildup on living vessel walls.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 a illustrates a basic multimonostatic mode configuration that includes a single transducer rotating about a fixed center.
FIG. 1 b illustrates a basic multistatic mode configuration that includes a fixed annular array of outwardly directed transducers.
FIG. 1 c illustrates a basic multistatic mode configuration that includes a rotating aperture.
FIG. 2 shows a conventional IVUS catheter.
FIG. 3 a shows a conventional IVUS catheter inserted into a diseased artery.
FIG. 3 b illustrates the RRDT geometry of the present invention when a catheter is inserted into a diseased artery.
FIG. 4 illustrates RRDT non-destructive evaluation within a bore hole.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the following detailed information, and to incorporated materials; a detailed description of the invention, including specific embodiments, is presented.
Unless otherwise indicated, numbers expressing quantities of ingredients, constituents, reaction conditions and so forth used in the specification and claims are to be understood as being modified by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by the subject matter presented herein. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the subject matter presented herein are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements.
General Description
The present invention employs inverse wave techniques to reconstruct images of a medium surrounding a physical probe in a plane perpendicular to an axis of rotation in a radial reflection configuration, i.e., in a multimonostatic or a multistatic arrangement disclosed infra, wherein one or more transmitting and receiving elements, more often at least about 15 of such elements, e.g., transducer(s), are at a fixed radius and designed to collect scattered fields, e.g., reflected and diffracted fields. Such a radial reflection diffraction tomography (RRDT) technique is based upon a linearized scattering model to form images given the disclosed physical transmitter and receiver configurations and the mathematical method, i.e., a Hilbert-based wave algorithm, utilized to invert the scattering collected fields.
As example embodiments, the multimonostatic and multistatic probes can be mounted at the end of a flexible substrate, such as a catheter or snaking tube that can be inserted into a part with an existing access hole or a medium (e.g., an artery) with the purpose of forming images of the plane perpendicular to the axis of rotation. By applying the Hilbert space inverse wave (HSIW) algorithm of the present invention to the collected data of such multimonostatic and multistatic probes, radial reflected diffraction tomographic images are readily obtained.
Specific Description
FIG. 1( a ) shows a basic multimonostatic conceptual arrangement of the present invention, wherein a single energy source element 1 , such as a transducer, can operate as both source and receiver (as denoted by T/R, to indicate transmitter and receiver) at multiple spatial locations. At each angular location along the illustrated dashed circumference, as denoted by the directional arrow, energy source element 1 can launch a primary field wave (not shown) and receive a reflected scattered field wave (not shown). Such an arrangement often requires a spectrally wide band frequency diverse source capable of producing frequencies from about 1 kHz to about 3 THz (Electromagnetic frequencies), often from about 100 Hz to about 10 GHz (Acoustic frequencies), more often between about 20 MHz and about 60 MHz (Acoustic frequencies), to provide spatial diversity so as to form images of a surrounding medium.
FIG. 1( b ) shows an example conceptual multistatic mode embodiment, wherein a plurality of fixed energy source elements 2 , e.g., transducers, are arranged as an annular array, generally designated by the reference numeral 20 . In succession, along for example, the illustrated directional arrow, each energy source element (for example, the element denoted by the letter T to indicate a transmitter) is capable of launching a primary field wave (not shown) and a backscattered field wave (not shown) is measured on all the remaining elements (as denoted by the letter R, indicating the remaining fixed elements are operating as receivers).
FIG. 1( c ) illustrates a beneficial multistatic conceptual arrangement that includes a plurality of energy source elements 4 configured in a rotating sub-aperture 6 , as denoted by the bi-directional arrow, formed by a single transmitter, as denoted by the letter T to indicate a transmitter, and surrounded by multiple receivers, as denoted by the letter R. At each angular location, as denoted by the single directional arrow along the illustrated dashed circumference, transmitter T can launch a primary field (not shown) and a backscattered field (not shown) is measured on all receivers R.
When operating in a reflection mode as disclosed herein, the mathematics applied to the collected data operate beneficially to image objects because the range resolution of the reconstructed image is proportional to the number of frequencies used in the reconstruction. Under the Hilbert space inverse wave algorithm, increasing the number of frequencies and transducers, increases the complexity of the reconstruction, the size of the intermediary data files, reconstruction time, and computer memory requirement. Thus, the trade-off between computer resources and resolution is a consideration. Nonetheless, the techniques employed in the present invention are beneficial even at acoustic frequencies from as low as about 100 Hz to as high as about 10 GHz. Such lower frequencies allow the disclosed embodiments to additionally be employed in borehole type of applications, such as, but not limited to, characterizing underground contamination plumes or waste in contamination barrels.
For either the multimonostatic or multistatic example embodiments, the planar reconstruction of the imaged object(s) requires that the one or more collected measurements map a pair of spatial variables (i.e., angular location and incident source frequency) of a physical object into the angular location and frequency parameters of the measured field.
An exemplary application of the present invention is in the characterization of vulnerable atherosclerotic plaque. Arthrosclerosis is a condition where the arteries are obstructed by the buildup of deposits, “intravascular plaque” (IVP), on the inside of arterial walls and such a buildup of deposits can lead to what is known to those of ordinary skill in the art as cerebrovascular disease, which is the third leading cause of death and the leading cause of major disability among adults. Plaque grows as a fibrous tissue encapsulating a lipid pool and as the plaque grow it may incorporate calcium. Of particular concern is vulnerable or unstable plaque because of the possibility of such plaque becoming inflamed and unexpectedly rupturing. Stable or non-vulnerable plaque, typically includes a thick layer of fibrous tissue of about 800 microns but is not life threatening and can be treated slowly. A thin fibrous cap of typically up to about 300 microns covering a pool of a soft lipid core typically characterizes vulnerable plaque. When such a cap is disrupted, the thin cap is compromised and the lipid deposited into the artery can produce adverse effects, such as thrombus formation, strokes and death.
FIG. 2 shows a conventional catheter, generally designated as reference numeral 200 , for intravascular tissue characterization, such as atherosclerotic vulnerable plaque. Such a catheter 200 , typically has an elongated flexible substrate 202 with an axially extending lumen 204 through which a guide wire 206 , and/or various other devices or other instruments can be delivered to a region of interest. An ultrasonic transducer assembly 208 is provided at the distal end 210 of the catheter, with a connector 214 located at the proximal end of the catheter for transducer manipulation and processing received transducer signals. Transducer assembly 208 can comprise a plurality of transducer elements 216 arranged in a cylindrical array centered about a longitudinal axis 218 of the catheter for transmitting and receiving ultrasonic energy. Adhesive (not shown) and or an end-cap (not shown) can be applied to transducer assembly 208 , and lumen 204 to protect such elements from the surrounding environment. Transducer assembly's 208 individual elements (not shown) and conductive acoustical backing (not shown) are often mounted on the inner wall of elongated flexible body 202 operating as the flexible substrate.
FIG. 3 a illustrates a typical IVUS method using such a catheter 200 , as shown in FIG. 2 a . In such a conventional application, catheter 200 , having a transducer assembly 208 that can launch an energy wave as a primary field (as denoted by the letter F) is inserted typically non-centered into a nominally circular diseased artery 302 . Around a wall 304 of artery 302 is a fibrous collagen plaque 306 . A lipid pool 308 can reside inside such a fibrous structure, wherein when a fibrous cap 310 of plaque 306 separating lipid pool 302 from the blood (not shown) within artery 302 is more than about 800 μm thick, plaque 306 is characterized as stable. However, in cases where cap 310 is less than about 300 μm thick, such a plaque is characterized as vulnerable, and is more likely to rupture and/or thrombosis.
The present invention utilizes the disclosed RRDT approach for improved intravascular applications such as characterizing plaque as discussed above, and incorporates various aspects of the method of utilizing a probe, such as, but not limited to, the catheter as shown in FIG. 3 a . However, such catheters 200 and similar probes known to those of ordinary skill in the art typically show angular overlap for beam processing, which results in loss of valuable image information of one or more objects of interest within a surrounding medium. The present invention overcomes such processing by incorporating novel improvements of the transmitters and receivers, by utilizing frequencies between about 20 MHz (Acoustic) and about 60 MHz (Acoustic), and by utilizing RRDT techniques of the present invention as discussed herein. Such novel embodiments accounts for phase, amplitude, and beam diffraction, to recover not only such loss of valuable image information information but to further enhance the imaging capabilities of the invention by providing images with improved lateral resolution of the acoustic absorption and sound speed.
FIG. 3 b shows the geometry incorporated by the RRDT method of the present invention. FIG. 3 b shows a cross-sectional view of a catheter 200 , having an outer diameter between about 0.25 mm and about 5 mm, being inserted into an artery 302 , having a surrounding plaque 306 that includes a cap 310 and a lipid pool 308 . Inserted into artery 302 is a non-centered catheter 200 , which includes a transducer assembly (not shown) that can be disposed about the distal end of catheter 200 , as disclosed in the present invention, with a radial location specified by r O ≡R O (cos θ O , sin θ O ), where R O is the catheter 200 probe radius, a constant. At each angular location, θ O , transducer assembly 208 , as shown in FIG. 3 a , launches a primary field F radially outward (as denoted by the letter r) into a medium, such as the blood (not shown) and surrounding tissue in this example, and the transducer arrangement, as disclosed in the present invention, can measure a reflected scattered field (not shown) having, for example, at least up to about 90 degrees of angular content from one or more objects, such as the linings of cap 310 that overlies lipid pool 308 .
As another example embodiment, the RRDT method and apparatus of the present invention can be combined with elastography to gain further insight into a surrounding medium's elastic properties and provide further information in the determination of characterizing plaque as vulnerable or stable. Generally, the contrast in elastic properties between a lipid pool and a fibrous cap is evident. By utilizing elastography, the elastic properties of a vessel wall can be obtained by observing a deformation of the vessel due to an external pressure, such as the pressure produced by a heart. Such a change in the arterial pressure due to the pumping action of the heart produces a measurable deformation of the tissue surrounding the vessel. Such a deformation can be measured by tracking a motion of patterns in successive intravascular scans as disclosed by the present invention. By knowing the arterial pressure and the measured deformation, the present invention can recover elastic properties of the surrounding tissue. From such elastic properties, one can further characterize the surrounding tissue to predict plaque composition.
FIG. 4 illustrates a further beneficial embodiment, wherein the present invention can be utilized for non-destructive characterization (i.e., RRDT imaging) in applications other than for intravascular RRDT imaging. As shown by the example cross-sectional underground view of a borehole 404 in FIG. 4 , a flexible substrate 400 or snake-like tube having a transducer assembly 402 similarly configured like the intravascular RRDT application discussed above, can be lowered into bore hole 404 so as to image a site using RRDT techniques. Such an arrangement can launch a primary field (denoted by the letter F) and receive diffracted energy waves having frequencies often between about 100 Hz and about 300 Hz, to determine the state of buried wastes, such as waste within a radioactive waste drum barrel 410 or a biohazardous container, and/or to track a plume 412 of underground contaminants. In a similar manner, disclosed probes herein, can be inserted into waste drum barrels 410 , or weapons (not shown) or any part having an existing access hole, such as, but not limited to, an automobile engine, and determine the state of the part or material.
Hilbert Space Wave Inversion
Hilbert spaces are spaces constructed using vectors. Specifically they define vector spaces where sets of vectors in the space “add up” to another vector, an analog to Euclidean space where measurements can be added to result in another valid measurement. Hilbert spaces are particularly useful when studying the Fourier expansion of a particular function. In the Fourier transform, a complex function describing a waveform is re-expressed (transformed) into the sum of many simpler wave functions. A Hilbert space describes the “universe of possible solutions” given one particular such function. The Hilbert space inverse wave (HSIW) algorithm of the present invention enables an inverse for any multistatic or multimonostatic geometry with any combination of sources, receivers, and frequencies.
In a radial reflection device of the present invention, such as an intravascular ultrasound probe having an outer diameter between about 0.25 mm and about 5 mm, or a probe configured to non-destructively characterize buried wastes (e.g., tracking plumes of underground contaminants of materials), evaluating the state of materials residing in waste drum barrels or weapons, or to non-destructively evaluate parts with existing access holes (e.g., automobile parts), acquired data are collected at discrete angular locations. Such angular locations are denoted by:
R n t ≡R 0 (cos θ n , sin θ n ) (1)
for transmitter locations, where θ n =nΔθ src for n=0,1 . . . , N src −1, where N src 2π/Δθ, and Δθ src is the source angular increment.
Similarly, receiver locations are given by:
R m r ≡R o (cos θ m , sin θ m ) (2)
where θ m =mΔθ rcv for m=0,1 . . . , N src −1, where N rcv 2π/Δθ rcv , and Δθ rcv is the receiver angular increment.
For each source, configured receiver(s) can record a backscattered field as a time series that can be digitized for processing. Discrete Fourier transforming the time series data result in the spectrum of one or more measured wave forms at discrete frequencies. The forward scattering equation under the Born approximation with both spatial and frequency diversity is given by:
ψ B scat ( R m r ,R n t ,ω l )= P (ω l ) k O 2 (ω l )∫ dr ′ G ( R m r ,r ′ ,ω l ) o ( r ′ ) G ( r ′ ,R n t ,ω l ), (3)
where ω l ,l=0,1. . . , N f −1 are the discrete frequencies and N f is the number of frequencies in the pulse band width.
The HSIW as disclosed herein interprets Equation (3) as a mapping from a continuous object space to a discrete measurement space. The object space is the physical (x,y) space of the object function. The measurement space includes discrete angles and temporal frequencies at which the scattered data are collected. The scattering operator projects the object onto the measurement space. The forward propagation or projection kernel is defined as:
Π*( r )≡ P (ω l ) k O 2 (ω l ) G ( R m r ,r,ω l ) G ( r,R n t ,ω l ), (4)
where Π(r) is a J≡(N src ×N rcv ×N f ) element column vector, and P(ω l ) is the incident pulse spectrum. Mathematically, the projection is represented as an inner product between the object function and the kernel via:
D=∫dr Π*( r ) o ( r )≡<Π, o >, (5)
where D is a J element column vector, and where each element represents a particular source, receiver, and frequency combination. Symbolically, the forward scattering operator, K, is defined as:
K[•]≡∫drΠ*( r )[•]. (6)
The HSIW method of the present invention is employed to derive an inverse of the operator as shown in equation (6). The singular value decomposition (SVD) of K is given as:
K=USV † , (7)
where the columns of U form an orthonormal set of column vectors, u j , which span a measured data space, and the components of V form an orthonormal set of vectors, v j (r), which span an object space. S is a diagonal matrix of singular values, σ j . It is emphasized that the u j are complex column vectors where as the v j (r) are complex functions of r. The set of normal equations for such a singular system are:
Kv j ( r )=σ j u j , (8)
K † u j =σ j v j ( r ), (9)
KK † u j =σ j Kv j ( r )=σ j 2 u j , (10)
K † Kv j ( r )=σ j K † u j ( r )=σ j 2 v j ( r ), (11)
The inversion method of the present invention estimates the object function of equation (5) given measured data in D. Such an inversion incorporates expanding the object function in terms of v j (r):
o ^ ( r ) = ∑ j = 0 J - 1 α j v j ( r ) , ( 12 )
where the α j are constant coefficients to be determined. Substituting the object expansion into equation (5) results in:
D
=
∫
ⅆ
r
Π
*
(
r
)
∑
j
=
0
J
-
1
α
j
v
j
(
r
)
=
∑
j
=
0
J
-
1
α
j
∫
ⅆ
r
Π
*
(
r
)
v
j
(
r
)
,
(
13
)
Applying the definition of the K operator in equation (6) to equation (8) yields an expression for the integral of equation (13),
Kv j =∫dr Π*( r ) v j ( r )=σ j u j , (14)
which reduces equation (13) to:
D
=
∫
∑
j
=
0
J
-
1
α
j
σ
j
u
j
,
(
15
)
Using the orthogonality of the u j vectors, the unknown α j is solved as follows:
u i † D = ∑ j = 0 J - 1 α j σ j u i † u j = ∑ j = 0 J - 1 α j σ j δ ij = α i σ i , ( 16 )
resulting in:
α
i
=
u
i
†
D
σ
i
,
(
17
)
The adjoint of the forward scattering operator, K † and the singular values and singular vectors, σ j , u j , and v j (r) are now required. First, the following inner product equation defines the adjoint,
< u,Kv >=< K † u,v>, (18)
Using the definition of the forward scattering operator from equation (16) results in:
u † ∫dr Π*( r ) v ( r )=∫ dr ( u † Π*( r )) v ( r ), (19)
By comparing the right hand sides of equations (18) and (19), the following definition of the adjoint of the forward scattering operator is obtained:
K † [•]≡[•]·Π T ( r ). (20)
The σ j and u j are determined by solving the eigenvalue equation of equation (10) formed by the outer product of the forward scattering operator with its adjoint. Explicitly, the outer product is represented by:
(∫ dr Π*( r )Π T ( r )) u j =σ j 2 u j , (21)
which is a J×J eigenvalue equation of the form Ax=λx. The Π(r) vectors are known analytically and can be evaluated numerically. It follows that the elements of the outer product matrix can be computed numerically and the resulting system solved numerically for the σ j 2 and u j . Given these and using equation (19) to solve for v j (r) results in:
v
j
(
r
)
=
1
σ
j
Π
T
(
r
)
u
j
.
(
22
)
Substituting equations (17) and (22) into equation (12) yields the final expression for the reconstruction:
o
^
(
r
)
=
∑
j
=
0
J
-
1
1
σ
j
2
Π
T
(
r
)
u
j
u
j
†
D
.
(
23
)
As described above, the Π(r) vectors of equation (4), and outer products and eigenvalues of equation (21) are computed numerically. The measurement system of the analytically described invention only measures part of the scattered field due to the aperture and the loss of the evanescent field information and accordingly, some of the eigenvalues, σ j 2 , are close to zero. Those eigenvalues and their corresponding eigenvectors determine the rank of the outer product matrix, and they must not be used in the reconstruction of equation (23). Thus, in the method of the present invention, a Best Rank N approximation is used to select the number of singular values/vectors. A ratio is computed as follows:
R ( N ) = ∑ j = 0 N - 1 σ j 2 ∑ j = 0 J - 1 σ j 2 , ( 24 )
where the singular values are assumedly arranged from smallest to largest: σ 0 2 ≦σ 1 2 ≦σ J−1 2 . Plotting R(N), the point at which the function starts to rise rapidly is graphically identified. The index of the singular value at which this occurs is labeled as J 0 . With this value determined, a final reconstruction is as follows:
o
^
(
r
)
=
∑
j
=
J
0
J
-
1
1
σ
j
2
Π
T
(
r
)
u
j
u
j
†
D
(
25
)
The HSIW as disclosed herein is flexible in that it allows any transducer configurations of the present invention and any number of frequencies to be used in forming such a final reconstruction.
Changes and modifications in the specifically described embodiments can be carried out without departing from the scope of the invention, which is intended to be limited only by the scope of the claims. | A wave-based tomographic imaging method and apparatus based upon one or more rotating radially outward oriented transmitting and receiving elements have been developed for non-destructive evaluation. At successive angular locations at a fixed radius, a predetermined transmitting element can launch a primary field and one or more predetermined receiving elements can collect the backscattered field in a “pitch/catch” operation. A Hilbert space inverse wave (HSIW) algorithm can construct images of the received scattered energy waves using operating modes chosen for a particular application. Applications include, improved intravascular imaging, bore hole tomography, and non-destructive evaluation (NDE) of parts having existing access holes. | big_patent |
CROSS REFERENCE TO RELATED APPLICATIONS
This is a divisional application of U.S. application Ser. No. 13/130,585 filed May 23, 2011, which is a US National Stage of International application PCT/NO2010/000002 filed 4 Jan. 2010.
FIELD OF INVENTION
The present invention concerns a biological oil composition, formulations comprising the oil composition, and the use of the oil composition in dietary supplements, functional foods and pharmaceutical products for the prevention or treatment of cardiovascular disease.
BACKGROUND OF INVENTION
In the 1970s, Bang, Dyerberg and Nielsen described the plasma lipid and lipoprotein pattern of Eskimos living on the west coast of Greenland, and compared it with that of the Danish population (H. O. Bang, J. Dyerberg and A. B. Nielsen. Plasma lipid and lipoprotein pattern in Greenlandic West-coast Eskimos. Lancet 1971; 1:1143-45). Later, Dyerberg and his collaborators (J. Dyerberg, H. O. Bang and N. Hjørne. Fatty acid composition of the plasma lipids in Greenland Eskimos. American Journal of Clinical Nutrition 1975; 28:958-66) related the differences they found, to the remarkably low mortality from coronary heart disease among the Eskimos, compared to Danes. Since the dietary fat intake was almost the same in the two populations, they suggested that the striking difference in coronary heart disease could be due to the big difference in the intake of marine fats and that coronary heart disease could be associated with the chemical nature of the dietary lipids (J. Dyerberg, H. O. Bang. E. Storffersen, S. Moncada and J. R. Vane. Eicosapentaenoic acid and prevention of thrombosis and atherosclerosis? Lancet 1978; 2:117-19). After these pioneering studies, it became evident that coronary heart disease, which is still among the most serious killer diseases in Western societies, could no longer be regarded merely as a lipid storage disease caused by excessive dietary fat intake.
The scientists who pioneered this research were the first to suggest that the anti-atherogenic factors in the traditional Eskimo diet were marine long chain poly unsaturated fatty acids (PUFAs). Their diet, consisting largely of seal, whale and seabirds, and, to some extent, fish, provided several grams—may be as much as 15 grams—of such fatty acids each day. This is far more than a typical “modern” Western diet contains.
Research during the last 30-40 years has confirmed the classical studies by the Dyerberg group and established a firm scientific foundation for a common understanding among scientists and other professionals: The health benefits of sea-food and marine oils can first and foremost be associated with two typical marine PUFAs, namely eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). This statement is in line with the conclusions and recommendations from the symposium “Beyond Cholesterol: Prevention and Treatment of Coronary Heart Disease with n-3 Fatty Acids, published by Deckelbaum et al. ( American Journal of Clinical Nutrition 2008; 87(suppl): 2010S-2S).
EPA and DHA contain, respectively, 20 and 22 carbon atoms with 5 and 6 conjugated double bonds, of which the first one is in the position 3 carbon atoms (n-3) counted from the hydrophobic (methyl) end of both these fatty acids. The abbreviation C20:5n-3 is often used as a chemical designation for EPA and C22:6n-3 for DHA. Phytoplankton in the marine environment is the primary producers of EPA and DHA, which follow the food-web from this first trophic level via zooplankton to fish and sea-mammals. Plant food oils and animal fat contain low levels, if any, of EPA and DHA.
EPA and DHA are believed to be particularly important in prevention of cardiovascular disease. Even modest sea-food intake, supplying 250 mg of EPA and DHA daily, seems sufficient to reduce the risk of coronary death by 36% and to reduce mortality in the general population by 17% (U. J. Jung et al. American Journal of Clinical Nutrition 2008; 87(suppl): 2003S-9S).
Physiological and molecular mechanisms proposed to explain the cardioprotective effects of EPA and DHA, include 1) lowering the levels of triacylglycerol and free fatty acids in plasma, 2) increasing high density lipoprotein (HDL) levels and decreasing low density lipoproteins (LDL) levels, 3) decreasing platelet aggregation, 4) decreasing cholesterol delivery and cholesterol deposition in arterial walls, 5) decreasing arterial inflammation. These are interactive mechanisms involving complex and diverse biochemical mechanisms, including effects of EPA and DHA as well as of their transformation products (prostaglandins, prostacycline, thromboxans, leukotrienes) on modulation of immunity and inflammation and gene expression in different cells and tissues. Although the health benefits of EPA and DHA no longer can be questioned, the mechanisms involved are too complex to be fully understood. For instance, it is still a puzzling fact that “the major mechanisms underlying the beneficial effects of n-3 fatty acids in the prevention and treatment of coronary artery disease appears to be distinct from effects on lowering plasma triacylglycerol concentrations” (Deckelbaum et al., American Journal of Clinical Nutrition 2008; 87(suppl): 2010S-2S).
Preclinical and human clinical studies during the last 30-40 years have provided consistent evidence that consumption of sea-food and marine food oils is beneficial for the health, and it has become generally accepted among those skilled in the art that these health benefits are, first and foremost, associated with EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). The total evidence related to the ability of these two marine n-3 PUFAs to prevent coronary heart disease is so overwhelming that it has become part of a primary prevention strategy of health authorities in Western societies to recommend daily EPA and DHA consumption. In support of this strategy, it can be referred to the symposium “Beyond Cholesterol: Prevention and Treatment of Coronary Heart Disease with n-3 Fatty Acids” summarized and discussed by R. J. Deckelbaum et al. ( American Journal of Clinical Nutrition , 2008; 87 (suppl): 2010S-2S). Moreover, concentrates of EPA and DHA, produced as disclosed in U.S. Pat. Nos. 5,502,077, 5,656,667 and 5,698,594, have been approved by the US Food and Drug Administration (FDA) as pharmaceutical preparations that reduce the level of blood components regarded as risk factors for coronary heart disease.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a representative visual illustration of plaque formation in aortas of female mice fed a diet to which was added the biological oil composition (Diet 1) or the EPA/DHA-concentrate (Diet 2), compared to the reference diet (Diet 3).
FIG. 2 illustrates the average growth of female mice (n=10) on the three experimental diets.
FIG. 3 shows the average weight of different organs of female mice (n=10) fed the three experimental diets (WAT=white adipose tissue).
DETAILED DESCRIPTION OF THE INVENTION
In the description of the present invention below the terms biological oil composition, copepod oil, copepod oil composition, oil composition are used interchangeable.
EPA and DHA are predominant fatty acids present in marine fish, whale, seal and crustaceans. Also, the oil present in the marine copepod Calanus finmarchicus is a rich source of EPA and DHA, but this oil differs from other marine oils in a number of other chemical characteristics. Compared to other marine oils, the copepod oil of the present invention is very rich in the C18:4n-3 PUFA (stearidonic acid, SDA). Unlike other common marine food oils, the PUFAs present in the copepod oil exist predominantly as monoesters with long chain monounsaturated alcohols i.e. wax esters. Compared to other common dietary marine oils, the copepod oil of the present invention contains a relatively high proportion of free fatty acids, low amounts of triglycerides, and high levels of astaxanthin and cholesterol.
Based on the common understanding that EPA and DHA are the key factors responsible for the beneficial effects of marine oils in prevention and treatment of coronary artery disease, the biomedical effects of these two fatty acids have been compared with those of the copepod oil composition, as described in the present invention. The effects of the copepod oil according to the present invention have been compared with that of a concentrated EPA/DHA-preparation on atherosclerotic plaque formation and on total cholesterol level in mice, adjusted so that copepod oil provided the same total amount of EPA and DHA as the total amount of EPA and DHA in the reference preparation. In these studies, experimental animals (Apolipoprotein E (ApoE) deficient mice) feeding on an atherogenic high fat (21% w/w) diet containing 0.2% (w/w) cholesterol were used.
Although there are differences in chemical composition between the copepod oil composition of the present invention and other dietary marine oils, the remarkable difference in biological activities, as described in the present invention, could not at all be predicted by anyone working on the effects of marine PUFAs on coronary heart disease. Most striking is the highly unexpected finding that the biological oil composition of the present invention, as opposed to concentrated EPA/DHA, has a statistically significant ability to inhibit formation of atherosclerotic plaques. It also differs from EPA and DHA in the way it affects the pattern of lipid deposition in the body of the experimental animals. The copepod oil described in the present invention is in itself a novel anti-atherosclerotic composition.
The biological oil composition according to the present invention also shows a significant effect on blood cholesterol level. Total blood cholesterol levels are significantly lower in animals fed with a diet comprising the biological oil composition according to the present invention as compared with the levels in animals fed a diet comprising concentrated EPA/DHA
The biological oil composition according to the present invention is derived from a marine copepod, preferably a copepod of the genus Calanus , such as Calanus finmarchicus , using freshly harvested, frozen/thawed or dehydrated raw material. Oil compositions according to the invention may be obtained by any method known to the person skilled in the art such as, but not limited to, conventional fish oil production technology, biotechnological methods, organic solvents or supercritical fluid extraction, or cold pressing. Independent of the procedure of obtaining the oil and the yield of oil, the typical gross composition will be as shown in Table 1. To illustrate the uniqueness of the biological oil composition according to the present invention, the corresponding compositions of conventional fish oil (cod liver oil) and krill oil are shown for comparison. It is evident from this gross chemical analysis that these oils are highly different, in particular regarding their contents of triglycerides, phospholipids, monoesters (wax esters), and of astaxanthin. It should be noted that wax esters constitute the major lipid component in the copepod oil of the present invention, unlike both cod liver oil and krill oil.
TABLE 1 Typical chemical composition of three different marine oils: (A) Copepod oil from Calanus finmarchicus caught in Norwegian waters, (B) cod liver oil from Atlantic cod Gadus morhua , and (C) krill oil from Euphausia superba caught in the Southern ocean, given in mg/g oil. Lipid classes A 1 B 2 C 3 Triglycerides 60 955 260 Free fatty acids 80 14 13 Fatty alcohols 62 0 0 Saturated fatty acids 190 160 300 Monounsaturated 125 385 300 Polyunsaturated 270 475 387 n-3 fatty acids >250 395 332 n-6 fatty acids <15 50 55 Cholesterol 40 12 50 Wax esters (fatty acid/alcohol esters) 650 0 0 Polar lipids (phospholipids, free 200-260 18 670 fatty acids, free fatty alcohols) Neutral lipids (triglycerides, wax 740-800 967 310 esters, cholesterol) 1 Copepod oil produced by Calanus AS (www.calanus.no). 2 From Falch, E., Rustad, T., and Aursand, M. By-products from gadiform species as raw material for production of marine lipids as ingredients in food or feed. Process Biochemistry 2006; 41: 666-674. 3 From Phleger, C. F., Nelson, M. N., Mooney, B. D., and Nichols, P. D. Interannual and between species comparison of the lipids, fatty acids, and sterols of Antarctic krill from the US AMLR Elephant Island survey area. Comparative Biochemistry and Physiology Part B 2002; 131: 733-747.
Besides the notable difference in gross chemical composition (Table 1), the three marine oils used here for illustration purposes, are highly different also in their content of individual fatty acids (Table 2).
TABLE 2
Fatty acid composition of three different marine oils: (A)
Copepod oil from Calanus finmarchicus caught in Norwegian
waters, (B) cod liver oil from Atlantic cod Gadus morhua , and (C) krill
oil from Euphausia superba caught in the Weddell Sea, given in mg/g oil.
Fatty acids
A 1
B 2
C 3
14:0 FA (myristic)
108
40
119
15:0 FA
6
0
0
16:0 FA (palmitic)
72
112
209
16:1 n-9
1.8
0
0
16:1 n-7 FA
16
61
0
16:1 n-5 FA
0
0
56
17:0 FA
1.7
0
0
16:2 n-4 FA
1.7
0
0
18:0 FA
4.5
27
15
16:3 n-3
0.8
0
0
18:1 n-9 FA (oleic)
23.4
167
170
16:4 n-3
2.2
0
0
18:1 n-7 FA
2.8
40
70
18:2 n-6 FA
10.2
19
25
18:3 n-3 FA
24.4
14
9
20:0 FA
0
0
0
18:4 n-3 FA (stearidonic, SDA)
109.7
21
51
20:1 n-11 FA
5.3
0
0
20:1 n-9 FA (gadoleic)
27
98
13
20:4 n-6 FA
2.0
8
7
20:4 n-3 FA
9.0
0
0
22:1 n-11 (+20:4 n-3 FA)
42.7
8.5
0
22:1 n-9 FA
2.7
0
0
20:5 n-3 FA (eicosapentaenoic, EPA)
67.0
72
128
22:4 n-6 FA
10.5
0
0
24:1 n-9 FA
2.9
0
0
22:5 n-3 FA
3.7
20
0
22:6 n-3 FA (docosahexaenoic, DHA)
54.7
188
101
Sum identified
612.7
895.5
973
1 Copepod oil produced by Calanus AS (www.calanus.no).
2 From Standal, I. B., Praël, A., McEvoy, L., Axelson, D. E., and Aursand, M. Discrimination of Cod Liver Oil According to Wild/Farmed and Geographical Origins by GC and 13C NMR. J. Am Oil Chem Soc 2008; 85: 105-112.
3 From Hagen, W., Kattner, G., Terbrüggen, A., and Van Vleet, E. S. Lipid metabolism of the Antarctic krill Euphausia superba and its ecological implications. Marine Biology 2001; 139: 95-104.
The most noteworthy difference in fatty acid composition between the three oils, is the very high stearidonic acid (SDA) content in the copepod oil.
In the oil composition of the present invention, SDA, EPA and DHA exist to a large extent as esters with long chain alcohols. A typical composition of wax esters and long chain alcohols in the copepod oil of the present invention is shown in Table 3.
TABLE 3
Typical composition of wax esters and alcohol/fatty acid combinations
(% (w/w)) in copepod oil derived from Calanus finmarchicus . 1
Major alcohol/
Minor alcohol/
Wax ester
fatty acid
fatty acid
% (w/w)
30:1
14:0/16:1
16:1/14:0
0.8
32:1
16:0/16:1
14:0/18:1
1.9
32:2
16:1/16:1
14:0/18:2
0.6
32:4
14:0/18:4
16:0/16:4
0.9
34:1
16:0/18:1
14:0/20:1
—
20:1/14:0
17.6
34:2
16:0/18:2
16:1/18:1
0.9
34:3
16:0/18:3
16:1/18:2
—
34:4
16:0/18:4
16:1/18:3
2.7
34:5
14:0/20:5
16:1/18:4
0.4
36:1
20:1/16:0
16:0/20:1
—
22:1/14:0
21.9
36:2
20:1/16:1
16:1/20:1
2.3
36:5
16:0/20:5
20:1/16:4
1.1
36:6
16:1/20:5
14:/22:6
0.3
38:1
22:1/16:0
16:0/22:1
2.8
38:2
22:1/16:1
20:1/18:1
3.9
38:3
20:1/18:2
22:1/16:2
0.4
38:4
20:1/18:3
22:1/16:3
0.9
38:5
20:1/18:4
22:1/16:4
5.4
38:6
16:0/22:6
16:1/22:5
—
40:2
20:1/20:1
22:1/18:1
5.9
40:3
22:1/18:2
0.7
40:5
22:1/18:4
20:1/20:4
4.7
40:6
20:1/20:5
1.5
42:2
22:1/20:1
20:1/22:1
12.7
42.6
22:1/20:5
20:1/22:5
1.5
42:7
20:1/22:6
2.0
44:2
22:1/22:1
4.9
44:7
22:1/22:6
0.6
1 Compiled from Graeve, M. and Kattner, G. Species-specific differences in intact wax esters of Calanus hyperboreus and C. finmarchicus from Fram Strait - Greenland Sea. Marine Chemistry 1992; 39: 269-281.
In conclusion, the copepod oil of the present invention differs markedly from typical fish oil and krill oil in both gross chemical composition and fatty acid content. However, like other marine oils it comprises EPA and DHA.
In spite of its high wax-ester content, the oil composition of the present invention is a low-viscous and completely free-flowing liquid at room-temperature. One of the reasons for this is that the alcohols of the wax esters are predominated by medium-length monounsaturated alcohols, typically 80% or more (mainly C20:1 and C22:1).
Depending on the analytical methods used, the typical content of wax-ester of the oil composition of the present invention is 70-90%, whereas it contains 10-20% of other components such as free fatty acids, triacylglycerols, sterols and pigments. In certain applications, it may be advantageous or even desirable to remove free fatty acids and other components by suitable methods known to those skilled in the art. Thus, in one embodiment of the preset invention the oil composition may contain up to 100% wax ester.
It has been found that the copepod oil according to the present invention has markedly different biological effects than a concentrated preparation of EPA and DHA used in the same concentration as in the copepod oil. Particularly the composition according to the present invention prevents the formation of atherosclerotic plaque and thus is useful in the prevention and treatment of cardiovascular disease. The composition according to the present invention is also found to have an effect on the total blood cholesterol level and is useful in the prevention and treatment of hypercholesterolaemia and elevated blood cholesterol levels.
The biological oil composition according to the present invention comprises from 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, by weight up to 75%, 80%, 85%, 86%, 87%, 88%, 89% 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, 100% by weight of wax esters. Preferably the biological oil composition comprises from 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87% 88%, 89% by weight up to 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, 99.5%, 100% by weight of wax esters.
Further the biological oil composition of the present invention comprises from 5%, 6%, 7%, 8%, 9%, 10% by weight up to 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20% by weight of SDA.
The content of EPA in the biological oil composition may be 3%, 4%, 5%, 6%, 7%, by weight up to 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15% by weight. The composition may comprise 2%, 3%, 4%, 5% by weight up to 6%, 7%, 8%, 9%, 10% by weight of DHA.
In one embodiment, the present invention provides a biological oil composition wherein the composition comprises 20-100% by weight of wax esters, preferably 50-100% by weight of wax esters, more preferred 70-100% by weight of wax esters for use as a medicament for the prevention and treatment of cardiovascular disease. The oil composition may be isolated from a marine copepod, preferably one of the genus Calanus , and more preferably said copepod is of the species Calanus finmarchicus.
In other embodiments of the invention the present invention provides a biological oil composition for the use as a medicament in the prevention and treatment of atherosclerosis, hypercholesterolaemia and elevated blood cholesterol levels.
In another embodiment the present invention provides an oil composition that further comprises 5-20% by weight of SDA.
In yet another embodiment the present invention provides an oil composition comprising 3-15% by weight of EPA and 2-10% by weight of DHA.
In a further embodiment of the present invention an oil composition comprising 20-100% by weight of wax esters, preferably 70-100% by weight of wax esters, 5-20% by weight of SDA, 3-15% by weight of EPA and 2-10% by weight of DHA is provided.
In another embodiment of the present invention an oil composition comprising fatty alcohols and SDA, DHA and EPA as monoester with fatty alcohols is provided.
In a further embodiment the present invention provides an oil composition comprising 1000-4000 ppm of astaxanthin, mainly in esterified form.
A dietary supplement formulation comprising an oil composition as described above is also provided by the present invention.
A functional food formulation comprising an oil composition as described above is also encompassed by the present invention.
In yet another embodiment of the present invention a pharmaceutical formulation comprising an oil composition as described above is provided.
The formulation according to the invention comprising an oil composition as described above may be provided in capsules, tablets, emulsions or tonics and may comprise one or more pharmaceutically acceptable additive selected from the group consisting of adjuvans, antioxidants, emulsifiers, surfactants and carriers.
The present invention further provides the use of an oil composition as described above for the manufacturing of a product for the prevention or treatment of a cardiovascular disease, particularly atherosclerosis, hypercholesterolaemia and elevated blood cholesterol levels.
The present invention also provides a method for the prophylaxis or treatment of cardiovascular disease, particularly atherosclerosis, hypercholesterolaemia and elevated blood cholesterol levels wherein the individual in need of such prophylactic or curative treatment is orally administered with a pharmaceutical composition comprising a biological oil composition wherein the composition comprises 20-100% by weight of wax esters, preferably 50-100% by weight of wax esters, more preferred 70-100% by weight of wax esters, and wherein a daily dosage level in the range of 4-100 mg/kg body weight.
In another embodiment the present invention provides a method wherein the administered pharmaceutical composition further comprises 5-20% by weight of SDA.
In yet another embodiment the present invention provides a method wherein the pharmaceutical composition comprising 3-15% by weight of EPA and 2-10% by weight of DHA.
In a further embodiment of the present invention a method wherein the administered pharmaceutical composition comprises 20-100% by weight of wax esters, preferably 70-100% by weight of wax esters, 5-20% by weight of SDA, 3-15% by weight of EPA and 2-10% by weight of DHA is provided.
In another embodiment of the present invention a method wherein the administered pharmaceutical composition comprising fatty alcohols and SDA, DHA and EPA as monoester with fatty alcohols is provided.
In a further embodiment the present invention provides a method wherein the administered pharmaceutical composition comprises 1000-4000 ppm of astaxanthin, mainly in esterified form. The following non-limiting experimental part and examples illustrate and document the present invention.
EXAMPLES
Experimental
When studying the preventive efficacy of any drug candidate or dietary ingredient on coronary heart disease, the most reliable end-point analyses are the actual disease manifestations, such as, for instance, formation of atherosclerotic plaques. Effects on blood parameters considered to be indicative of the risk of disease development are of course important for evaluation of mode of action of new anti-atherogenic drug candidates, but it is preferable to relate such blood analyses to efficacy data on the disease manifestation itself. This has been the philosophy in the studies constituting the foundation of the present invention.
The biological effects of the copepod oil of this invention were recorded in mice deficient in apolipoprotein E (ApoE). Mice of this strain are routinely used to determine effects of dietary components on development of vascular inflammation and atherosclerotic plaques, since they develop atherosclerotic lesions according to a pattern very similar to that of humans, and they are useful model animals for studies of biochemical and cellular processes involved in initiation, progression and regression of atherotrombotic disease. The studies were carried out at the Faculty of Medicine at the University of Tromsø (Norway). Three groups of ten female mice were installed at an age of 7 weeks and fed 3 different diet treatments (see below) for 13 weeks.
The mice were fed ad libitum with an experimental high fat (21% w/w) and cholesterol (0.2% w/w) diet, rich in bioavailable carbohydrates (sugar/dextrin) and with a high proportion of saturated fat (sniff Spezialdiaten GmbH, sniff EF Clinton/Cybulsky (II) mod.). The composition of this diet promotes development of obesity and of atherosclerotic lesions. The diet was added either 1% (w/w) of the copepod oil of the present invention (Diet 1) or 0.1223% (w/w) of an EPA/DHA-concentrate (Diet 2), producing two experimental feeds with equal contents of EPA and DHA. The cholesterol content of these two diets and of the control diet (Diet 3) without added oil was adjusted to 0.20% by adding cholesterol, taking into account the cholesterol present in the feed ingredients and in the copepod-oil itself. The composition of the experimental diets is shown in Table 4.
TABLE 4
Experimental diet for rats and mice with high fat/cholesterol
content (type ssniff ® EF Clinton/Cybulsky (II) mod.) 1
with ingredient and nutritional profile for the three test groups
Diet 1
Diet 2
Copepod oil
EPA/DHA
Diet 3
preparation
concentrate
Control
Ingredients
Sucrose, %
33.0876
33.0476
32.5867
Milk fat, %
19.9692
19.9692
19.9692
Casein (vitamin free), %
19.4700
19.4700
19.4700
Maltodextrin, %
9.9846
9.9846
9.9846
Corn starch, %
4.9923
4.9923
4.9923
Powdered cellulose, %
4.9923
4.9923
4.9923
AIN-76 Mineral Mix, %
3.4946
3.4946
3.4946
Calanus Oil-841, %
1.0000
—
—
Omacor Oil-842, %
—
0.1223
—
AIN-76A Vitamin Mix, %
0.9985
0.9985
0.9985
Corn Oil, %
0.9985
0.9985
1.9985
Calcium carbonate, %
0.3994
0.3994
0.3994
DL-Methionine, %
0.2995
0.2995
0.2995
Choline bitartrate, %
0.1997
0.1997
0.1997
Cholesterol, %
0.1498
0.1498
0.1498
Ethoxyquin, %
0.0040
0.0040
0.0040
Nutritional profile
Protein, %
17.4
17.4
17.4
Fat, %
21.0
21.0
21.0
Cholesterol, ppm
2 027
2 027
2 027
Carbohydrates, %
48.9
48.9
48.4
Fiber (max), %
5.0
5.0
5.0
Energy, kcal/g
4.48
4.56
4.55
From
Protein, %
15.3
15.3
15.4
Fat (ether extract), %
41.6
41.7
41.8
Carbohydrates, %
43.0
43.0
42.8
1 Produced by ssniff Spezialdiäten GmbH (www.ssniff.de).
The copepod oil preparation was an experimental product provided by Calanus AS, Tromsø, Norway (www.calanus.no). The EPA/DHA concentrate used as reference test substance was the lipid lowering drug Omacor (Pronova Biopharma ASA, P.O. Box 420, NO-1327 Lysaker, Norway). According to the manufacturer (www.pronova.com) this product contains 90% omega-3-acid ethyl esters of EPA (460 mg/g) and DHA (380 mg/g) and is manufactured using fish oil as a starting material.
The experimental mice were monitored daily, and weighed at regular intervals. Samples of blood serum were taken at different points for later analysis of various blood parameters including lipids and fatty acids. The mice were sacrificed at the end of the experiment, and all relevant organs were dissected out following standard procedures. Following dissection of the sacrificed mice, the aortas were isolated, cleaned and cut open longitudinally, pinned to a white cardboard and fixed in 10% formalin for at least 24 hours. The aortas were stained with Oil Red O (Sigma) before analysis. After rinsing, the aortas were mounted on microscopic slides, and images (2,700 dpi) were acquired using a SprintScan 35 scanner (Polaroid, Cambridge, Mass., USA) equipped with GeoScan Enabler (Meyer Instruments, Houston, Tex., USA). The images were analyzed for positive areas, adopting the state-of-the art calibration and image analyses methodology. The total lesion area was quantified in each group by computer-assisted quantitative morphometry as described by N. V. Guevara et al. (The absence of p53 accelerates atherosclerosis by increasing cell proliferation in vivo. Nature Medicine 1999; 5:335-339).
Biological Effects
i) Atherosclerosis
It has been found that the copepod oil of the present invention has markedly different biological effects than a concentrated preparation of EPA and DHA used in the same concentration as in the copepod oil. This was a highly unexpected finding, considering the overwhelming consensus among the skilled in the art, that the positive health effects of marine oils are associated with their content of EPA and DHA, exclusively.
The results are shown in Table 5 and in FIGS. 1-3 .
The effect of the copepod oil of the present invention and of EPA/DHA-concentrate on atherosclerotic plaque formation in the aortas of female mice is shown in Table 5. The copepod oil preparation had a striking and statistically highly significant effect on reduction of plaque formation both in the aortic arch (p=0.002) and the total aorta (p=0.001) compared to control. Also the EPA/DHA-concentrate reduced plaque formation compared to control, but the effect did not meet the requirements of statistical significance.
TABLE 5
The effect of a copepod oil preparation and of concentrated
EPA/DHA on atherosclerotic plaque formation 1 in the
ascending aortic arch, thoracal, abdominal and perirenal
segments of the aorta in female mice.
Diet 1
Diet 2
Copepod oil
EPA/DHA
Diet 3
preparation
concentrate
Control
Target region
(n = 10)
(n = 10)
(n = 10)
Aortic arch (A)
15.1
18.0
22.0
Thoracal (B)
7.93
9.51
12.16
Abdominal (C)
1.93
2.52
3.94
Perirenal (D)
1.36
2.27
1.94
Total aorta (B-D)
4.59
5.87
7.22
1 The figures represent the average lesion area in percent of total area of each target region at time of sacrifice. See FIG. 1 for the subdivision of target regions (A-D) of the aorta.
Growth of the mice is shown in FIG. 2 . Although the mice grew fastest on feed enriched with copepod oil, and thrived well on that diet, this apparent difference does not meet the requirements for statistical significance. There was no difference between the groups in feed intake and no negative effects could be observed on animals fed the experimental diets.
Weight of different organs is shown in FIG. 3 . Although there was a higher level of fat deposited in the white adipose tissue (WAT) in mice fed the copepod oil, the difference was not statistically significant. However, it is a noteworthy observation indeed that the copepod oil of the present invention reduces plaque formation while more lipids are deposited in lipid storage tissues.
ii) Blood Cholesterol Level
The copepod oil has a notably more pronounced anti-atherosclerotic effect than purified EPA and DHA at same concentration as in this oil. The mechanisms involved in this effect of the copepod oil may accordingly be additive to the EPA- and DHA-effects or be entirely different.
The results shown in Table 6 illustrate that Calanus Oil differs from EPA and DHA also regarding the effect on blood cholesterol level in the experimental animals. Whereas the cholesterol level in blood of animals fed the EPA/DHA-diet was the same as in control animals after 13 weeks of feeding, the cholesterol level in blood of the Calanus Oil group was notably lower. Both treatment groups seem to have a slight, and similar, triglyceride lowering effect compared to control.
TABLE 6
Effects of the dietary supplements on bodyweight, food
intake and plasma lipids in apoE-deficient female mice
after 13 weeks of treatment, as mean values +− SEM.
Diet 1
Diet 2
Copepod oil
EPA/DHA
Diet 3
Female apoE-
composition
concentrate
Control
deficient mice
(n = 10)
(n = 10)
(n = 10)
Bodyweight (g)
Initial
18.4 +/− 0.3
18.7 +/− 0.3
18.6 +/− 0.4
Final
38.9 +/− 1.2
37.7 +/− 1.6
34.6 +/− 1.2
Food intake
2.72 +/− 0.05
2.72 +/− 0.07
2.77 +/− 0.04
(g/day)
Total cholesterol
12.3 +/− 1.25
15.9 +/− 1.28
16.1 +/− 1.25
(mmol/L)
Triacylglycerol
0.82 +/− 0.05
0.84 +/− 0.07
0.96 +/− 0.05
(mmol/L) | This invention relates to a biological oil composition, preferably obtained from a copepod, most preferably the copepod Calanus finmarchicus and the use thereof to prevent or treat formation of atherosclerotic plaques and hence development of coronary heart disease. The composition comprises the same marine n-3 polyunsaturated fatty acids (PUFAs) generally regarded as being responsible for the anti-atherosclerotic effect of marine oils, namely EPA (C20:5n-3 eicosapentaenoic acid) and DHA (C22:6n-3 docosahexaenoic acid). However, quite unexpectedly, it has been found that the oil composition of the present invention has a remarkably higher ability to prevent formation of atherosclerotic plaques than what can be attributed to EPA and DHA alone, and moreover, unlike EPA and DHA alone it has a notable blood cholesterol lowering effect. | big_patent |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of application Ser. No. 08/088,581, filed Jul. 9, 1993, abandoned, which is a continuation of application Ser. No. 07/689,643, filed Apr. 23, 1991, abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to pharmacological compositions which contain polyelectrolyte complexes in microparticulate form and at least one active substance. The active substance can in this case be embedded in the matrix of the polyelectrolyte complex, itself be a partner in the polyelectrolyte complex or be bound to a partner of the polyelectrolyte complex. By active substances are meant primarily pharmacological active substances such as active peptides, proteins, enzymes, enzyme inhibitors, antigens, cytostatics, antibiotics, antiinflammatory agents or vaccines. In the particular case of ultrasonic diagnostic aids, also meant as active substances in this connection are contrast agents such as gases, for example air, oxygen or inert gases.
2. Description of the Prior Art
It is known from the literature that multiple charged macromolecular compounds with ions of opposite charge form ionic compounds which may, depending on the charge distribution and the molecular weight of the final product, precipitate from aqueous solutions. In this case, low molecular weight ions of the same charge are displaced by the higher molecular weight compound. These phenomena are also collected together under the overall term "polyelectrolyte effect". State of the art are, inter alia, the formation of gels by mixing alginate solutions and Ca 2+ . Protein precipitations also take place in some cases in accordance with this principle. Polyelectrolyte complexes can in principle be composed of a macromolecular, multiply charged component of one polarity and many low molecular weight ions of the other polarity, or else of two macromolecular partners, each of which is multiply charged with different polarity. Hollow capsules which are prepared from such polyelectrolyte complexes are described, for example, in BE-A 901.704, EP-A 0 127 989, EP-A 0 188 309, EP-A 0 127 713, DE-A 32 09 127, EP-A 0 152 898, U.S. Pat. No. 4,487,758, DE-A 32 09 098, U.S. Pat. No. 4,409,331, A. Johansen and J. M. Flink, Enzyme Mikrob. Technol., 1986, vol. 8, 145-148 or C. E. Camp and S. S. Sofer, Enzyme Mikrob. Technol., 1987, vol. 9, 685-689.
Formulations and active substance combinations which not only convert the active substance in a non-deleterious manner into a form which can be administered but also have a specific effect on the biodistribution, bioavailability or absorption of the pharmaceutical are becoming increasingly important in modern pharmaceutical technology. It is possible therewith to achieve both new therapeutic and diagnostic areas of use and, for example, an increase in the therapeutic index of an active substance. Particulate systems of extremely small diameter (so-called micro- or nanoparticles) in particular have suggested themselves recently as important administration form, both in the oral and in the parenteral area. Usually employed in this connection as carrier substances are biocompatible, biodegradable polymers.
SUMMARY OF THE INVENTION
It has now been found, surprisingly, that polyelectrolyte complexes show to a particular extent properties, both as carrier substances and as active substance components, which meet the profile of requirements of biocompatible (biodegradable) polymer systems and can be adapted to meet the various requirements. It was known of hollow capsules, including polyelectrolyte complex capsules, that active substance incorporation capacities of 90% and more can be achieved. This was not to be expected with microparticles which are composed of just such polyelectrolyte complexes, because these complexes form only at the interface (around the active substance). This particularly applies when they are prepared from purely aqueous reaction solutions into which active substances, which are soluble therein, are introduced. It was therefore all the more surprising that particulate polyelectrolyte complexes also display incorporation capacities of more than 90%. It was furthermore surprising that in the preparation of such polyelectrolyte complex matrices there was formation of fine particles in the μm range or emulsions and not, as was really to be expected, an agglomerated mass. It is possible according to the invention to prepare such colloidal systems of micro/nanoparticles especially well from polyelectrolyte complexes. There is then in vivo, via solution equilibria and charge interactions, a slow decomplexation as well as a breakdown of complexands, which results in dissolution of the complex and release of the active substance. These release conditions can, as can the consistency properties, be controlled via the composition of the complex.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The partners employed for the complex formation are preferably biocompatible, biodegradable polyacids and polybases which are naturally occurring or composed of natural subunits. In this case, "poly" means that the compound carries more than one charge of the same polarity, preferably a large number of such charges. The particular counterions can be composed either of low molecular weight ions or likewise of a polyionic species. Either one or both ionic partners can be either inorganic or organic in nature. In the case of organic polyions, hydrophobic substituted derivatives prove suitable and preferable.
Preferred materials for the preparation of biocompatible polyelectrolyte complex/active substance combinations are, as polyacids: xylan polysulfate, partially hydrophobically esterified xylan polysulfate, polysulfates of other polysaccharides such as, for example, starch hydrolysates, inulin, hydroxyethylstarch, dextrans and the partially hydrophobically substituted derivatives thereof in each case, and poly(amino acids) such as polyaspartic acid or polyglutamic acid and the hydrophobically substituted derivatives thereof in each case. As polybases: poly-L-lysine of various defined molecular weight ranges, poly-α,β-(2-dimethylaminoethyl)-D,L-aspartamide (PDAA), copolymers of PDAA and hydrophobically esterified poly-α,β-(2-hydroxyethyl)-D,L-aspartamide (PHEA), chitosan, lysine octadecyl ester, aminated dextrans, aminated cyolodextrins, aminated cellulose ethers, aminated pectins and the partially hydrophobically substituted derivatives thereof in each case.
In one preferred embodiment, the polyelectrolyte complex contains a polyacid which is selected from: xylan polysulfates, dextran sulfates, poly(amino acids) such as polyaspartic acid or polyglutamic acid, polysaccharide polysulfates such as sulfates of starch hydrolysates, inulin, hydroxyethylstarches, polysaccharide polysulfonates, polysaccharide polyphosphates, polyphosphates, and, more preferably, the polyelectrolyte complex contains a polyacid which is selected from: in each case partially hydrophobized (for example etherified, esterified) derivatives of xylan polysulfate, polysulfates of other polysaccharides such as, for example, starch hydrolysates, inulin, hydroxyethylstarches, dextrans; of poly(amino acids) such as polyaspartic acid or polyglutamic acid, and of polysaccharide polysulfonates, polysaccharide polyphosphonates, polyphosphates.
In another preferred embodiment, the polyelectrolyte complex contains a polybase which is selected from: poly-L-lysine, poly-α,β-(2-dimethylaminoethyl)-D,L-aspartamide, chitosan, lysine octadecyl ester, aminated dextrans, aminated cyclodextrine, aminated cellulose ethers, aminated pectins, and, more preferably, the polyelectrolyte complex contains a polybase which is selected from: in each case (for example by partial or complete esterification and/or etherification) hydrophobized derivates of: poly-L-lysine of various molecular weight ranges, poly-α,β-(2-dimethylaminoethyl)-D,L-aspartamide, chitosan, aminated dextrans, aminated cyclodextrins, aminated cellulose ethers, aminated pectins and copolymers of poly-α,β-(2-dimethylaminoethyl)-D,L-aspartamide and hydrophobically esterified poly-α,β-(2-hydroxyethyl)-D,L-aspartamide.
Microparticles composed of polyelectrolyte complexes can, depending on the requirements, be prepared in average particle sizes from a few nm up to a few hundred μm. It is also possible by definition for the microparticles to be in the form of emulsions. The breadth of the size distribution can be adjusted, for example by the stirring speed on mixing the polyelectrolytes, the drop rate, the nozzle diameter, the pH and by suitable choice of the polyelectrolyte partners. It is particularly advantageous to carry out the formation of the complexes with addition of auxiliaries such as amphiphilic molecules (for example ® Pluronic) or colloidal substances (for example adjuvants) with high incorporation capacity. These parameters can be determined in simple routine tests and adjusted to the required particle size and particle size distribution. Particles below 5 μm in diameter are suitable for intravenous injection. Particles with a diameter <15 μm, preferably <10 μm can be employed as s.c. or i.m. injectable depot forms and as a vehicle to increase the enteral absorption.
The incorporation of an active substance in the polyelectrolyte complex particles/colloids can be carried out in at least 4 ways: a) incorporation by "entrapment" of the active substance, which is present in solution, on precipitation of the complex, b) incorporation by absorption of the active substance from a solution with which the already prepared polyelectrolyte complexes come into contact (especially in the case of porous materials or gels with "sponge" properties), c) precipitation of the polyelectrolyte complex, in which case the active substance is chemically bound to at least one complex partner and, d) incorporation by employing the active substance as partner in the formation of the polyelectrolyte complex. This usually requires at least one charge or polarizable group on the active substance. The invention therefore also relates to a process for preparing pharmaceutical compositions containing polyelectrolyte complexes and active substances, where a solution of an acidic and a solution of a basic substance, where at least one of these substances must be polymeric, are mixed and where a) either one of the partners is an active substance or contains the latter in chemically bound form, or b) the active substance is contained in one of the solutions, and subsequently the resulting polyelectrolyte complex is precipitated in microparticulate form or, where appropriate, converted into a microparticulate form.
Polyelectrolyte complex/active substance formulations show, because the consistency properties can be widely varied on the one hand and can be very specifically adjusted on the other hand, property profiles as required for diverse pharmaceutical applications.
Thus, it has emerged that the cytostatic daunorubicin and the polyacid xylan polysulfate produce macroparticles which contain daunorubicin and release the latter in buffer solution or in biological systems uniformly over a lengthy period, during which they are broken down. If polybases are also added and/or the polyacid is changed, especially by replacing xylan polysulfate by xylan polysulfate which is partially substituted with palmitoyl ester groups, it is possible to reduce the particle size to <<5 μm and the result is an i.v. injectable system with the release properties described above. The therapeutic index of the cytostatic can be drastically increased with a slow-release form of this type. The activity properties of other low molecular weight active substances such as antibiotics (for example tetracycline) or other cytostatics can also be distinctly improved in this way.
If proteins are incorporated in polyelectrolyte complex microparticles, it is possible in this way both to protect them from hydrolytic attack and to achieve controlled release profiles. Thus, for example, vaccine preparations can be produced using vital proteins or similar substances suitable for vaccination and can, depending on the particle size, be injected i.m. or even administered orally, in which case there is absorption in the gastrointestinal tract of particles <5 μm, and subsequent antigen expression/immunization occurs. It is possible, with such antigen-containing polyelectrolyte complexes according to the invention, to achieve release profiles which allow a large dose of the vaccine to be delivered shortly after administration and after a period of, for example, 4 weeks (booster). The substances particularly suitable for forming polyelectrolyte complexes in this case are described in Example 3.
It is also possible to convert peptide-based active substances by means of polyelectrolyte complex preparations into suitable long-term systems. These formulations are in some cases superior to the known polymeric depot systems for LHRH analogs, for example, both because the degradability is better and because the release profiles are defined.
Polyelectrolyte complexes are likewise suitable for preparing wound ointment preparations which contain, for example, antibiotics or proteins as regeneration promoters.
The polyelectrolyte complex microparticles according to the invention are also outstandingly suitable as air-containing echogenic contrast agents for ultrasonic diagnosis. Polyelectrolyte complex particles composed of hydrophobically esterified dextran sulfate and of a copolymer of PDAA and hydrophobically esterified PHEA (for abbreviations, see page 4) have proven particularly suitable for ultrasonic diagnosis.
The invention is explained in more detail hereinafter by means of examples. The particle size has been determined by microscopic methods or by filtration through filters of defined pore size and, in some cases, by Coulter counter (from Coulter Electronics) or flow cytometer.
EXAMPLES
a) Preparation of polyelectrolyte complexes
Example 1
Complex of xylan polysulfate and poly-L-lysine 3800
A 0.1% aqueous solution of each of xylan polysulfate sodium salt (from BENE-Chemie) and of poly-L-lysine of average molecular weight 3800 (from Sigma) is made up. Sufficient HCl is added to the poly-L-lysine solution for the pH to be 3. The xylan polysulfate solution is likewise adjusted to pH 3 (HCl) and added dropwise via a metering pipette. The polyelectrolyte complex precipitates and is separated off by centrifugation and membrane filtration. After washing with H 2 O, the microparticulate product can be freeze-dried. The particle size can be controlled by the vessel size, the stirring speed, the diameter of the dropwise addition nozzle and the dropping rate and can be adjusted from the region around 20 nm to 100 μm.
EXAMPLE 2
Complex of palmitoylxylan polysulfate with 20% palmitic acid residues and chitosan
0.1% solutions are prepared as in Example 1. The procedure corresponds to that employed in Example 1, only that no pH control is carried out in this case, and polylysine is replaced by chitosan (from Protan). The palmitoylxylan polysulfate can be prepared, for example, by the process described in German Patent Application P 3921761.2. Chitosan 143 is used. The resulting particles are large agglomerates (100 μm and larger) and can be reduced to a size of 1-4 μm by grinding in a mortar.
EXAMPLE 3
Polyelectrolyte complex particles composed of palmitoylxylan polysulfate with 20% palmitic acid and chitosan with incorporation of human serum albumin as model protein for vaccines.
The procedure is carried out as described in Example 2, only that 0.2% human serum albumin (from Sigma), dissolved in water, is added to the palmitoylxylan polysulfate solution before the dropwise addition. Particles in the range 2-5 μm can be obtained after grinding. See Example 10 for the determination of the albumin release.
EXAMPLE 4
Preparation of rabies vaccine/polyelectrolyte complex microparticles
Particles in the <5 μm range can be obtained with two different preparations:
I.
Polyacid: Palmitoylxylan polysulfate with 20% palmitic acid
Polybase: Lysine octadecyl ester
Auxiliary: ®Pluronic F68
50 mg of polyacid are dissolved in 5 ml of a 0.1% strength solution of rabies vaccine from Behringwerke (the solution is aqueous and contains 40% sucrose), the pH is 6.3. 50 mg of polybase are added to 5 ml of a 0.5% strength solution of ®Pluronic F68 in water. The polyacid/vaccine solution is added dropwise to the stirred polybase solution (which has pH 5.8). After centrifugation (10 min, 2000 rpm), the clear supernatant is separated off, and the residue is made into a paste with H 2 O and freeze-dried. Yield 779.7 mg of particles. The amount of the employed vaccine incorporated can be found by resuspension and analysis of the supernatant (in H 2 O) to be 90%.
II.
Polyacid: Palmitoylxylan polysulfate with 20% palmitic acid
Polybase: 40:60 copolymer of poly-α,β-(2-dimethylaminoethyl)-D,L-aspartamide (40%) and poly-α,β-(2-palmitoyloxyethyl)-D,L-aspartamide (60%)
no auxiliary
Once again, two solutions are made up, each containing 50 mg of polyacid/base. The polyacid solution is identical to that in I. The polybase solution is identical to that in I except that it contains no ®Pluronic. Both solutions are adjusted to pH 7 and, as in I, centrifuged and the residue is made into a paste and freeze-dried. The incorporation efficiency corresponds to that in I. Yield: 76.5 mg.
EXAMPLE 5
Vaccination of mice against human serum albumin with polyelectrolyte complex microparticles
The following microparticle preparations were employed:
Sample I: Xylan sulfate esterified with about 15% palmitic acid/lysine octadecyl ester +7% Pluronic®68, 5-30 μm
Sample II: Xylan sulfate esterified with about 15% palmitic acid/lysine octadecyl ester, ≦10 μm
Sample III: Xylan sulfate esterified with about 15% palmitic acid/poly-L-lysine 4 kDa +7% Pluronic® F68, 2-50 μm
Sample IV: Polyaspartic acid 30 kDa/poly-α,β-(2-dimethylaminoethyl)-D,L-aspartamide/poly-.alpha.,β-(2-palmitoyloxyethyl)-D,L-aspartamide copolymer (40:60), <10 μm
Sample V: Xylan sulfate/lysine octadecyl ester, 10-20 μm
All the samples contained about 7% by weight human serum albumin (Behringwerke). These complexes were resuspended in concentrations of 66.67 μg/ml, 6.67 μg/ml and 0.67 μg/ml in PBS (phosphate-buffered saline). 0.3 ml of each vaccine was administered s.c. to, in each case, 10 NMRI mice weighing about 20 g. 14 weeks after the vaccination, the experimental animals were revaccinated with the same dose. The antibodies directed against human serum albumin in the serum of the experimental animals were quantified in an ELISA. Used as comparison was aluminum hydroxide Al(OH) 3 which is known as a good adjuvant and is contained in various vaccines.
ELISA titer after inoculation with 6.67 μg of formulation/ml (average dose), 2, 4, 8, 14 (revaccination), 16 and 21 weeks after the first vaccination:
______________________________________Sample Day 0 Day 2 Day 4 Day 8 Day 14______________________________________I <1:300 <1:300 1:300 1:900 1:900II <1:300 <1:300 1:300 <1:300 <1:300III <1:300 1:300 1:900 1:2700 1:8100IV <1:300 <1:300 <1:300 1:2700 1:8100V <1:300 1:900 1:2700 1:8100 1:24300Al(OH).sub.3 <1:300 1:900 1:900 1:900 1:900______________________________________Sample Day 16 Day 21______________________________________I 1:72900 1:72900II 1:24300 1:24300III 1:72900 1:24300IV 1:72900 1:72900V 1:72900 1:72900Al(OH).sub.3 1:8100 1:24300______________________________________
Administration of the same vaccine to guinea pigs likewise resulted in distinct seroconversion.
EXAMPLE 6
Polyelectrolyte complex particles composed of polyaspartic acid and poly-α,β-(2-dimethylaminoethyl)-D,L-aspartamide (PDAA) with incorporation of tetracycline as example of a low molecular weight active substance.
The procedure is as described in Example 3, except that a 0.2% solution of tetracycline in water is employed in place of human serum albumin. See Example 11 for the tetracyctine release.
EXAMPLE 7
Polyelectrolyte complex particles composed of xylan polysulfate and daunoribicin.
10 mg of xylan polysulfate are dissolved in 0.5 ml of H 2 O. 100 μl of a 10% daunorubicin solution (daunorubicin from Sigma) are diluted to 0.4 ml with water. The daunorubicin solution is added dropwise to the xylan polysulfate solution. The resulting suspension contains particles whose diameter is in the 5 μm range. See Example 12 for the daunorubicin release.
EXAMPLE 8
Polyelectrolyte complex particles composed of palmitoylxylan polysulfate with 20% palmitic acid, daunorubicin and lysine octadecyl ester.
1 ml of a solution which contains 1% each of daunorubicin and lysine octadecyl ester is adjusted to pH 4. A 1% solution of palmitoylxylan polysulfate, likewise 1 ml, likewise adjusted to pH 4, is added dropwise. The resulting suspension can no longer be fractionated by filtration. The particles can be adjusted by altering the concentration, the stirring speed, the dropping rate and the nozzle diameter in the range from 100 nm to 1 μm (see Table 1).
TABLE 1______________________________________Particle Concen- Stirring Dropping Nozzlesize tration speed rate diameter______________________________________ 1 μm 0.1% 300 min.sup.-1 100 min.sup.-1 0.5 mm 10 μm 0.5% 300 min.sup.-1 100 min.sup.-1 0.5 mm 20 μm 1% 300 min.sup.-1 100 min.sup.-1 0.5 mm100 nm 0.1% 1000 min.sup.-1 100 min.sup.-1 0.5 mm 20 nm 0.1% 1000 min.sup.-1 100 min.sup.-1 0.2 mm 80 μm 1% 100 min.sup.-1 100 min.sup.-1 0.5 mm100 μm 1% 100 min.sup.-1 200 min.sup.-1 0.5 mm______________________________________
EXAMPLE 9
Echogenic injectable polyelectrolyte complex microparticles as ultrasonic contrast agent.
The polyelectrolyte complex particles are prepared as follows:
In each case a 1% strength aqueous solution at pH 7 is made up from dextran sulfate (M=6000) in which about 20% of the dextran OH groups have been esterified with caproic acid and the remaining OH groups have been sulfated ("hydrophobically esterified dextran sulfate", "polyacid ") and from a copolymer of poly-α,β-(2-dimethylaminoethyl)-D,n-aspartamide (60%) and poly-α,β-(2-palmitoyloxyethyl)-D,L-aspartamide (40%) ("polybase"). The polyacid solution is added dropwise to the polybase solution and stirred at room temperature for 10 minutes, the complex is removed by centrifugation, the solution is decanted off, and the solid is made into a paste with and freeze-dried.
Test as contrast agent:
Freeze-dried and resuspended microparticles with a size of the order of 1-3 μm are investigated in a phantom which represents a model of the heart and extremely small capillary vessels (lung model) for the ultrasonic contrast brought about by incorporated air. The particles pass through the capillaries unhindered.
b) Release tests
EXAMPLE 10
Release of albumin from the microparticles described in Example 3
A microparticle suspension in phosphate buffer is shaken continuously. After 1, 4, 7, 13, 21 add 28 days, the supernatant is removed and then the albumin content is determined by electrophoresis known from the literature. The result is a profile with 2 release maxima as is required for various vaccines:
______________________________________Release on day 1 4 7 13 21 28Albumin released 50 20 <5 <5 10 <5______________________________________
Particles are no longer present after somewhat more than one month.
EXAMPLE 11
Tetracycline release from the polyelectrolyte complex particles of Example 6.
The breakdown test is carried out as test 10. The active substance is determined by a UV spectroscopic method known from the literature.
The results are:
______________________________________Release on day 1 4 7 13Tetracycline released 30 10 10 <5______________________________________
EXAMPLE 12
Release of daunorubicin from the polyelectrolyte particles of Example 7.
The particle suspension is placed in a Soxhlet extractor and extracted with H 2 O for several days. Daunorubicin in the extract is determined by a fluorometric method known from the literature (at 472/555 nm). It emerges that the release, based on the total amount of daunorubicin weighed in, is as follows:
______________________________________after 3.5 h 11 h 20 h 29 h the releasewas: 8.5% 10.5% 15.0% 26.2% of the amount______________________________________
of active substance employed. | The invention relates to a pharmacological composition comprising a polyelectrolyte complex, in particular a polyacid with an average particle size of less than 15 μm and an active agent, among which are active peptides, proteins, enzymes, enzyme inhibitors, antigens, cytostatics, antiinflamatory agents, antibiotics and vaccines. The said composition ensures that the active agent is converted in a non-deleterious manner into a form which can be administered. In addition, the biodistribution, bioavailability and absorption of the pharmaceutical are beneficially affected. | big_patent |
BACKGROUND
1. Field of Invention
This invention relates to a golf ball teeing device that easily permits a golfer, without bending over, to insert a golf tee into the ground with a golf ball situated on top of the tee in preparation for driving the ball.
2. Description of Prior Art
Elderly golfers often find it difficult to bend over to place a golf tee in the ground and place a ball upon the tee. Additionally, golfers with back or knee problems have the same difficulty.
Inventors have described several devices that allow the tee and ball to be positioned without bending over. Some of these devices can also be used to retrieve the tee out of the ground once the ball has been hit. These devices all involve a mechanism that clamps the ball and tee to the device which is mounted to the end of a handle or pole long enough to preclude the user from having to bend over. At the held end of the pole is a control which is in communication with the clamping mechanism. This control permits the golfer to unclamp the tee and ball from the device once the tee has been inserted into the ground.
All of these devices are relatively elaborate and incorporate the use of several moving parts as exemplified by U.S. pat. Nos. 2,609,198 to Armstrong (1952), 4,526,369 to Phelps (1985), 4,616,826 to Trefts (1986), 4,714,250 to Henthorn (1987), 4,969,646 to Tobias (1988), 4,819,938 to Hill (1989), 4,949,961 to Milano (1990), 4,951,947 to Kopfle (1990), 5,080,357 to Wolf(1992), 5,171,010 to fanoue (1992), 5,205,598 to Miller (1993), 5,330,177 to Rogge (1994), 5,330,178 to Geishert (1994), 5,439,213 to Pimentel (1995), 5,499,813 to Black (1996), and 5,503,394 to Mauck and Shelton (1996).
No inventor known to me has been able to eliminate the need for the golfer to manually unclamp the ball and tee from the device. Therefore, the prior devices all require a long handle with an unclamping control mounted to the end of the handle. Furthermore, they require some sort of mechanical linkage between the control and the clamping mechanism at the other end. This causes the following significant disadvantages common to all prior ball teeing devices:
(a) The long handle and elaborate mechanisms incorporated in these devices weigh too much to be comfortably carried by a golfer as an accessory to golf clubs.
(b) The elaborate nature of these devices make them too large to be carried in a golf bag in addition to golf clubs.
(c) The number of parts required causes the material and labor costs associated with producing these devices to be inefficient with regard to bringing these devices to the buying public.
(d) The large. elaborate nature of these devices causes them to be visually unappealing as a golf accessory prohibiting their commercial success in the marketplace.
In addition to the above disadvantages, the use of such devices is cumbersome, time consuming, and inefficient. Using these devices to tee up a ball and to retrieve the tee without bending over requires four trips to the golf bag as the golfer alternates between the device and his club. Some inventors have attempted to minimize this by incorporating the use of a sharp member to anchor the device to the ground in an upright position while the golfer uses the club. This allows the device and club to be transported to and from the golf bag together instead of alternately as described in U.S. pat. Nos. 4,951,947 to Kopfle (1990), 5,439,213 to Pimentel (1995), 5,499,813 to Black (1996), and 5,503,394 to Mauck and Shelton (1996). However, this requires the golfer to operate the large heavy device one-handed while holding the golf club in the other hand to keep from bending over. Additionally, the sharp anchor can be a safety hazard to the golfer.
With regard to other golf related inventions, inventors have described small light weight devices which can be temporarily attached to the end of a golf club to accomplish different tasks. For example U.S. pat. Nos. 2,801,875 to McEvoy (1957), 2,819,109 to Borah (1958), and 2,833,584 to McEvoy (1958) describe devices which are attached to the grip end of a golf club for use as golf ball retrievers.
Similarly, U.S. pat. Nos. 3.870,300 to Amendola (1975), 5,012,872 to Cohn (1991), and 5,094,456 to Mitchell (1992) describe devices which are attached to the grip end of a golf club to serve as sand trap rakes. These devices utilize a golf club as the handle making the devices themselves small, lightweight, and portable.
However, no other inventor has devised a tee and ball placing device which eliminates the need for an unclamping control incorporated into a long pole thereby allowing a golf club to be used as the handle. The teeing devices listed above all require the user to manually release the tee and ball by actuating some sort of control linkage incorporated into a long pole.
OBJECTS AND ADVANTAGES
Accordingly. several objects and advantages of my invention are:
(a) to provide a golf ball teeing device which can operate without a manually controlled unclamping mechanism integral with the device;
(b) to provide a golf ball teeing device which can utilize a golf club as a handle;
(c) to provide a golf ball teeing device which contains relatively few parts making the device lightweight;
(d) to provide a golf ball teeing device which is small, portable, and does not require a substantial amount of space in a golf bag;
(e) to provide a golf ball teeing device which can be quickly and easily used without requiring the cumbersome juggling of a large device and a golf club;
(f) to provide a golf ball teeing device which can also be used to retrieve the golf tee once the ball has been hit for both instances of the tee laying horizontally on the ground or remaining vertically inserted into the ground.
Further objects and advantages will become apparent from a consideration of the ensuing description and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric illustration of the front of a specific illustrative embodiment. FIG. 2 is an isometric illustration of the rear of a specific illustrative embodiment. FIG. 3 is an isometric illustration of a specific illustrative embodiment from another angle. FIG. 4 is a partial sectional view taken along line 4--4 of FIG. 1 showing a golf club grip inserted into the preferred embodiment. FIG. 5A is a front view showing a specific illustrative embodiment prior to inserting the tee into the ground with the ball and tee being clamped together. FIG. 5B is a front view showing a specific illustrative embodiment as the tee is inserted into the ground. FIG. 5C is a front view showing a specific illustrative embodiment ready to release the tee and ball which are no longer clamped to the device.
______________________________________Reference Numerals In Drawings______________________________________10 teeing device 12 golf ball14 golf tee 16 head of golf tee18 shank of golf tee 20 golf club grip22 housing 24 upper housing26 lower housing 28 top wall30 rear wall 32 left vertical wall34 right vertical wall 36 left recess38 right recess 40 opening42 bottom wall 44 slot46 rounded end 48 delayed urging means50 interface member 52 annular wall54 taper 56 gripping fingers58 voids 60 rounded bottoms62 outward flares 64 chamfered edges66 supporting ribs 68 clip70 radius 72 inward bend74 outward bend______________________________________
DESCRIPTION OF THE PREFERRED EMBODIMENT
THE entire device is referred to generally by the reference numeral 10. A golf ball is referred to generally by the reference numeral 12. A golf tee is referred to generally by the reference numeral 14, having a head 16, and a shank 18. A golf club grip is referred to generally by the reference numeral 20.
The perferred embodiment of the present invention is illustrated in FIG. 1. The invention comprises a housing 22, which includes an upper portion 24, and a lower portion 26. The upper portion 24 includes a top wall 28, a rear wall 30, left vertical side wall 32, and a right vertical side wall 34. Side walls 32 and 34 incorporate a recessed portion 36 and 38 respectively to facilitate easy removal of the device 10 from the teed golf ball 12. The lower end of the rear wall 30 contains an opening 40 that extends between the two side walls 32 and 34. The opening 40 has a height that will permit passage of the golf tee shank 18 but will not allow passage of the golf tee head 16 and is used to facilitate the retrieval of the golf tee 14 lying horizontally on the ground. The lower portion 26 of the housing 22 includes a bottom wall 42 which contains a slot 44 that extends inward from the edge of the bottom wall 42. The slot 44 terminates with a rounded end 46. The entire wall of the slot 44 is angled such that the slot is larger on the top surface of the bottom wall 42 than the bottom surface of the bottom wall 42. The edges of the housing 22 are typically chamfered or rounded to avoid snagging or personal injury.
Attached to the lower surface of the top wall 28 is a delayed urging means 48 which exhibits a delayed rebound after being compressed. Examples of such delayed urging means 48 are the ISODAMP® C-3000 series of energy absorbing foams manufactured by E-A-R Division, Cabot Corporation, Indianapolis, Ind. These foams rebound very slowly after being compressed. In the preferred embodiment, a cylindrical piece of E-A-R C-3002-50 low-recovery foam is used. However, means other than low-recovery foam could be used to provide a delayed urging function. The delayed urging means 48 is typically fastened to the top wall 28 by means of an adhesive. The placement of the delayed urging means 48 on the underside of the top wall 28 is such that it will be directly over the golf ball 12 when placed in the housing 22.
Attached to the bottom of the delayed urging means 48 is a rigid ball interface member 50 used to provide a uniform surface to contact the golf ball 12. In the preferred embodiment, this member is a ring shaped object with an outer diameter equal to the delayed urging means 48 diameter and an inner diameter sufficiently large enough to provide engagement of the golf ball 12. However interface members of other shapes would equally suffice. The interface member 50 is typically attached to the delayed urging means 48 by means of an adhesive. FIG. 3 shows a better view of the interface member 50.
The housing 22 height, interface member 50 size, slot 44 dimensions, and delayed urging means 48 size all affect the performance of the device 10. This combination of dimensions must be such that when the golf ball 12 is placed in the housing 22 below the interface member 50 and the golf tee 14 is slid into the slot underneath the ball 12, the delayed urging means 48 is slightly compressed exerting enough of a downward force to securely hold the ball 12 and tee 14 into the device 10. Additionally, these dimensions must be such that the delayed urging means 48 sufficiently further compresses due to the upward force on the tee 14 when the device 10 is used to insert the tee 14 into the ground. In the preferred embodiment, the interior height of housing 22 is 2.24 inches, slot 44 is 0.36 inches wide with angled walls at 21°, the interface member height is 0.12 inches with an inner diameter of 0.64 inches, and the delayed urging means 48 has a diameter of 0.75 inches and a height of 0.50 inches in its uncompressed state. These dimensions describe one possible embodiment of the invention. Other combinations of dimension values could also be used to achieve successful operation of the device 10.
Extending from the upper side of the top wall 28 is the portion used to attach the device 10 to a golf club grip 20 as shown in FIG. 4. From the top wall 28, an annular wall 52 extends upward vertically and then flares outward becoming a taper 54. The annular wall 52 provides clearance for the end of the golf club grip 20 which is often convex in shape. The taper 54 ensures that the device 10 is aligned with the axis of the golf club by centering the end of the golf club grip 20. The diameters at the bottom and top of the taper 54 are sized to accommodate the full range of golf club grip 20 diameters available in the market place. Above the taper 54 the wall angles inward forming a plurality of individual gripping fingers 56 capable of flexing outward. In the preferred embodiment four gripping fingers 56 are used; however, any number greater or equal to two would work. FIG. 1 shows how the gripping fingers 56 are separated from each other by voids 58. The voids 58 incorporate rounded bottoms 60 to reduce stress concentrations in the flexing material. The gripping fingers 56 are of sufficient height to prevent the device 10 from becoming skewed with respect to the axis of the golf club. FIG. 4 shows how the gripping fingers 56 incorporate outward flares 62 at the top to provide easy insertion of the golf club grip 20. The very top of the gripping fingers 56 incorporate chamfered edges 64 to also aid in the insertion of the golf club grip 20.
FIG. 1 shows a series of supporting ribs 66 used to provide strength to the annular wall 52 and to the taper 54 below the gripping fingers 56. These ribs 66 ensure that the stress created in the material during insertion of a golf club grip 20 will not cause a fracture in the material.
FIG. 2 shows a clip 68 extending from the rear of the housing 22 just above the opening 40. The clip 68 is shaped with a large enough radius 70 to permit the device 10 to be clipped to the side of a typical golf bag. The clip 68 incorporates an inward bend 72 towards the housing 22 permitting the device 10 to be securely clipped to the pocket of a golfer's clothing. An outward bend 74 at the top of the clip 68 allows the device 10 to be easily clipped to a golf bag, pocket, or belt.
In the preferred embodiment the entire device 10, except delayed urging means 48, is molded from an economical, flexible plastic material such as ABS. However, the device 10 can consist of any other material that exhibits the elasticity and impact resistance characteristics suitable for the application.
From the description above, a number of advantages of the present invention become evident:
(a) The device automatically unclamps the ball and tee once the tee is pushed into the ground since the delayed urging means becomes further compressed and will not immediately rebound.
(b) The golfer can use a golf club as the device handle since no handle mounted unclamping control is needed.
(c) The device makes it possible to tee up a golf ball from a standing position without the cumbersome use of relatively very large prior mechanisms.
(d) The device allows a golfer to tee up golf balls without bending over by only carrying a small, lightweight device during a golf outing.
(e) The device can be used to retrieve golf tees from the ground even if they are in a horizontal orientation.
Operation-FIGS. 5A, 5B, 5C
In use, the golfer removes the desired golf club from the golf bag and then unclips the device 10 from the golf bag, a pocket, a belt, or wherever the device 10 is stored. The device 10 is then attached to the golf club by pushing the gripping fingers 56 fully onto the end of the golf club grip 20 until the end of grip 20 comes in contact with the taper 54. A golf ball 12 is then placed in the housing 22 below the ball interface member 50. A golf tee 14 is then slid into slot 44 causing the ball 12 to push against the interface member 50 somewhat compressing the delayed urging means 48. The delayed urging means 48 exerts a downward force on the ball 12 clamping the ball 12 and tee 14 securely to the device 10 as shown in FIG. 5A The golf club is then held by the golfer at the club head end with the grip end towards the ground. The golf club is positioned in a vertical orientation with the shaft of the golf club perpendicular to the ground. The golfer holds the golf club at a height such that the tip of the golf tee 14 is a short distance above the ground as also shown in FIG. 5A. The golfer then moves the golf club straight down sinking the golf tee 14 into the ground. As the tee 14 enters the ground it exerts an upward force on the ball 12 causing the delayed urging means 48 to substantially compress. As this happens, the device 10 lowers with respect to the ball 12 and tee 14 such that the slot 44 is no longer in full contact with the underside of the tee head 16 as shown in FIG. 5B. Once the golf tee 14 has been sunk to the desired depth into the ground, the golfer releases the ball 12 and tee 14 from the device 10 by slightly moving the golf club straight up until the interface member 50 no longer is in contact with the ball as shown in FIG. 5C. The delayed urging means 48 remains compressed for a period of several seconds allowing the device 10 to be laterally removed from the teed ball 12 by moving the golf club in a motion parallel to the ground.
After teeing up the ball 12, the golfer then pulls the device 10 off the end of the golf club and uses clip 68 to temporarily fasten the device 10 to a pocket or belt while the ball 12 is hit. The device 10 can then be reinstalled on the golf club grip 20 to be used to retrieve the golf tee 14 without bending over. For instances when the tee 14 remains in the ground while hitting the ball 12, the golfer uses the golf club as a long handle and maneuvers slot 44 of the device 10 under the head 16 of the tee 14. The tee 14 can then be pulled out of the ground and retrieved without bending. For instances when the tee 14 comes out of the ground while hitting the ball 12 and is lying horizontally on the ground, the golfer again uses the golf club as a long handle and retrieves the tee 14 using the device 10. This is accomplished by maneuvering the bottom wall 42 of housing 22 underneath the shank 18 of the tee such that the tip of the tee 14 protrudes through opening 40 of the housing 22. The opening 40 will not permit passage of the tee head 16 allowing the tee 14 to be scooped up without bending.
Accordingly, this invention allows a golfer to easily tee up a golf ball without bending over. In addition, the invention permits a golfer to easily retrieve a golf tee without bending over whether or not the tee came out of the ground while hitting the ball. Furthermore, the teeing device has the additional advantages in that
it permits a golf club to be utilized as the handle reducing the weight and size of the device;
it is very simple to use with no cumbersome controls to release the tee and ball;
it can easily and nonintrusively be clipped onto a golfer's apparel while hitting the ball;
it can easily be attached to a golf bag;
it can be made from far fewer parts than prior tee setting devices.
Although the description above contains many specifics, these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the presently preferred embodiments of this invention. For example, a means other than low-recovery foam could be used to provide a delayed urging means. Furthermore, the dimensions given of the housing, interface member, low-recovery material, and slot could be different, the ball interface member could be eliminated; the gripping fingers could be of a different shape, the clip could be shaped differently, the supporting ribs could be eliminated, etc.
Thus the scope of the invention should be determined by the appended claims and their legal equivalents, rather than by the examples given. | A small, lightweight golf ball teeing device is disclosed for allowing a golfer to tee up a golf ball without bending over using a golf club as a handle for the device. A housing positions the golf ball over the golf tee. A delayed urging means is used to clamp the ball and tee to the housing. While the tee is inserted into the ground, the delayed urging means compresses and rebounds slowly releasing the ball and tee from the device. Gripping fingers are positioned on top of the housing to provide a secure, aligned attachment to a golf club grip. An opening in the housing permits horizontal golf tees to be scooped up without bending. A clip is incorporated with the housing to provide attachment to golf bags, belts, etc. | big_patent |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation of U.S. application Ser. No. 14/540,185, which was filed Nov. 13, 2014, now U.S. Pat. No. ______, which claims priority, under 35 U.S.C. §119(a), of European Application No. 13193375.6, which was filed Nov. 18, 2013, and each of which is hereby incorporated by reference herein.
BACKGROUND
[0002] The present disclosure relates to a person support apparatus, such as a bed and with a mechanism suitable for adjusting the height and orientation of a patient support frame forming part of that bed. It is more particularly suitable for a hospital or long-term care (LTC) bed.
[0003] Person support apparatus, such as hospital and long-term care beds, typically include a patient support deck and a support surface, such as a mattress, supported by the deck. The patient support deck may be controllably articulated so as to take up different support configurations.
[0004] The patient support deck is supported on a deck support or intermediate frame and the deck support frame is provided with a mechanism for adjusting the height of the deck and hence the height of the support surface above the floor on which the apparatus is located, and to control the orientation or inclination of the deck and hence the patient support surface relative to the floor. Adjustment of the height is helpful to allow care givers to access the patient, and to facilitate patient movement into and out of the bed. The inclination of the patient support surface is also desirable so as to make the patient more comfortable, or to, for example, take up the Trendelenburg position in which the body is laid flat on the back (supine position) with the feet higher than the head by 12-30 degrees, or the reverse Trendelenburg position, where the body is tilted in the opposite direction.
[0005] The deck support frame is supported on leg assemblies which are pivotally connected at their upper end to the deck support frame and which have linear actuators for pivoting the leg assemblies relative to the deck support frame and hence adjusting the height of the deck support frame. Separate and separately controllable head end and foot end leg assemblies are provided so that the height of the foot and head ends may be separately adjusted. The leg assemblies can be pivoted together by their respective actuators and thereby raise or lower the deck support frame whilst keeping it substantially parallel to the floor. Alternatively, one of the foot or head end assemblies can be pivoted to lower just one of the foot or head ends and thereby move the deck support frame into the Trendelenburg or reverse Trendelenburg positions.
[0006] Known arrangements for pivoting leg assemblies relative to a deck support frame to allow the raising and lowering of the deck support frame include a leg element pivotally connected at its upper end to a guide element which is coupled to and can slide along the outside of longitudinal elements arranged parallel to, or forming, the sides of the deck support frame. Those known arrangements comprise a U-shaped guide element arranged on its side (i.e. with its open side extending in a vertical direction) and arranged around the outside of longitudinal elements having a rectangular cross-section. Such arrangements suffer from a number of problems. These include: i) a risk of trapping fingers in the guide element which moves along the outside of the longitudinal elements: (ii) a need to overcome the frictional forces between the inner surface of the slideable guide element and the outer surface of the longitudinal element when pivoting the leg assembly and thereby sliding; and (iii) a propensity for dust and dirt to collect on the surface of the longitudinal element and hence interfere with the sliding operation.
[0007] US 2009/0094747 and US 2010/0050343 disclose alternative arrangements in which channels which correspond to U-shapes on their sides (i.e. with an open vertical side) are arranged on the sides of the intermediate or deck support frame and have follower or guide elements extending into the interior of the channels through the vertical open side. The follower or guide elements engage and run along an interior surface of the respective channels.
[0008] US 2006/0021143 discloses a further alternative arrangement in which guide tracks or channels are defined by slots extending through the vertical sides of longitudinal bed frame elements, and the upper end of the respective leg assemblies are provided with followers extending sideways out from the upper end of the leg assemblies to extend through or into the slots. The followers run along the guide tracks defined by the slots through the vertical sides of the bed frame elements.
[0009] A need exists for further contributions in this area of technology.
SUMMARY
[0010] An apparatus, system and/or method according to the present disclosure includes one or more of the features recited below or in the appended claims, and which alone, or in any combination, may define patentable subject matter:
[0011] The present disclosure, in a first aspect, provides a person support apparatus comprising: a person support frame for supporting a person support deck, the person support frame having two sides extending between a head end and a foot end; and a support assembly for supporting the person support frame and moving it relative to a floor surface, wherein the support assembly comprises at least one leg assembly pivotally coupled at a first upper end portion to the person support frame and coupled at its second lower end portion to floor engaging means, and an actuator element operable to move the leg assembly and thereby move the person support frame relative to the floor, wherein at least one of the sides of the person support frame comprises an inverted substantially U-shaped channel element having a substantially continuous upper surface, two substantially continuous side surfaces connected at their top edges to the upper surface, and a downward facing opening between the bottom edges of the two side surfaces, and the first upper end portion of the leg assembly includes a guide or follower element arranged to contact and run along an inner surface of the channel element.
[0012] This arrangement results in a deck support frame which is robust and stable and can accommodate the changes in geometry necessary for movement or adjustment between the horizontal, Trendelenburg and reverse Trendelenburg positions.
[0013] Some embodiments of the channel and roller mechanism change the height of a patient support deck by pivoting one or more leg assemblies relative to the under surface of the patient support frame.
[0014] Features of some illustrative embodiments include the following:
[0015] Some illustrative embodiments have a lower part count than known systems and are therefore likely to be both cheaper and more robust. More parts cost more to make and assemble and provide more elements capable of failure.
[0016] The opening of the channel carrying the guide elements or rollers faces the floor. This means that dirt is less likely to enter it and interfere with the mechanism. Furthermore, any dirt that enters will not be visible in normal use.
[0017] The leg assembly works vertically within the channel edges and a reduced force is therefore necessary to lift the patient support frame especially from the low position where the leg assemblies suspend a narrow angle relative to the underside of the patient support frame. The use of rollers in an optional embodiment rather than surfaces sliding relative to each other also reduces the frictional forces which must be overcome when moving the guide element. The use of a roller than a sliding element means that there is no need to overcome the friction between the sliding element and the frame element relative to which it slides thus reducing the force necessary to raise the deck support frame and makes the mechanism less likely to fail.
[0018] The use of a mechanism which includes a guide element inside a channel element means that the outside surface of the longitudinal channel element can be used as a fixing area for accessories or other elements.
[0019] Having the channel openly facing downwards and the guide element inside the channel make it harder for a patient or care-giver to trap their fingers or other body parts.
[0020] Features described in relation to one aspect and/or embodiment of the present disclosure may equally be applied to other embodiments and/or aspects of the present disclosure.
[0021] Additional features, which alone or in combination with any other feature(s), such as those listed above and/or those listed in the claims, may comprise patentable subject matter and will become apparent to those skilled in the art upon consideration of the following detailed description of various embodiments exemplifying the best mode of carrying out the embodiments as presently perceived.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Illustrative embodiments will now be described in detail, by way of example only, with reference to the accompanying drawings, in which:
[0023] FIGS. 1 a and 1 b are isometric and perspective views from, respectively, the foot and head ends of a patient support apparatus including a deck support frame according to one embodiment of the present disclosure;
[0024] FIG. 2 is side view of the patient support apparatus of FIG. 1 with the patient support deck in a lowered position;
[0025] FIG. 3 is a view similar to that of FIG. 2 but with the patient support deck in a lowered position;
[0026] FIG. 4 is a detailed view of a section through the top of one of leg assemblies of the apparatus in FIG. 1 ;
[0027] FIG. 5 is an end view of an alternative embodiment according to the present disclosure having a braking mechanism, in which the deck support frame is at its lowermost position and the brake engaged;
[0028] FIG. 6 is a detailed view of portion VI of FIG. 5 ;
[0029] FIG. 7 is a perspective view corresponding to the view of FIG. 6 ;
[0030] FIGS. 8 a and 8 b are diagrams setting out roller dimensions (in mm) for an embodiment according to the present disclosure;
[0031] FIG. 9 is a diagram setting out dimensions (in mm) for a channel element suitable for use with the roller of FIGS. 8 a and 8 b; and
[0032] FIG. 10 is a diagram setting out dimensions (in mm) for a suitable brake lever and channel element.
DETAILED DESCRIPTION
[0033] Hospital beds typically include a deck supporting a mattress or other patient support element (not shown in the Figs.). The deck may be divided into articulated sections so as to create various seating and lying down configurations. Articulated beds with a controllable articulation system for the patient support surface are known and are not a novel and inventive part of embodiments of the subject disclosure so will not be described in detail. An example of such an articulated patient support surface is shown in EP 2 181 685 and WO 2004/021952 to which reference should now be made and whose contents are hereby expressly incorporated herein by reference.
[0034] Referring to FIGS. 1 to 3 , a hospital bed support assembly according to one embodiment of the present disclosure includes a deck support frame 3 to which a headboard and a footboard may be mounted at, respectively, its head 4 and foot 5 ends. The head board is mountable on head board plates 33 and the foot board on foot board plates 34 . The deck support frame has two leg or support structures 6 pivotally mounted to its under surface. Each of the leg structures or assemblies 6 includes a pair of legs 7 each coupled to the deck support frame 3 by a moveable upper pivot or guide element 8 at their deck or upper end 9 . The moveable upper guide elements can move parallel to the longitudinal axis of the deck frame. For example, the moveable upper guide element 8 of the left-hand leg in FIGS. 2 and 3 can move in the directions shown by arrows D1 and D2.
[0035] The lower portions of the legs 7 of each pair of legs are connected together by a lower bracing cross-element 10 at the bottom 12 of the legs. The lower cross-elements 10 are each in turn connected to a lower longitudinal or side element and able to rotate about their longitudinal axis. In the embodiment shown in FIGS. 1 to 3 , each end of the foot end leg assembly lower cross-element is pivotally connected to a lower portion of a respective length extension element and the upper portion of each length extension element is pivotally connected to the lower longitudinal side element. The foot and head ends of the lower side elements 35 each have a castor or castor device 14 so that the support assembly can move over a floor or surface on which it is placed.
[0036] A pair of stabilizer elements 16 is connected to each pair of legs. A stabilizer element is connected to and links each leg to the underside of the deck support frame. The stabilizer elements 16 , which are each coupled to a leg 7 , are pivotally connected at their first upper ends 17 to the underside of the deck support frame 3 . The upper ends 17 of each stabilizer are connected to a fixed upper pivot 18 displaced from the leg upper moveable pivot 8 of the respective leg, and are pivotally connected at their second lower ends 19 to the respective pair of legs at a pair of respective lower stabilizer pivots 20 .
[0037] A stabilizer cross-element 37 is pivotally connected between the pair of stabilizers 16 for each leg assembly. The respective stabilizer cross-element is connected to each respective stabilizer at a point 36 between its upper 17 and lower 19 ends.
[0038] An actuator-stabilizer yoke 21 is connected to each stabilizer cross-element at a point substantially mid-way along the stabilizer cross-element so that it is in the middle of the bed. The actuator-stabilizer yoke 21 is pivotally coupled to an end of an actuator 22 (which may be a hydraulic actuator, or a linear actuator such as model No LA27 actuators supplied by Linak U.S. Inc. located at 2200 Stanley Gault Parkway, Louisville Ky. 40223) which controllably extends and retracts an actuator rod 23 connected to the actuator-stabilizer yoke 21 . Extension and retraction of the actuator rod 23 causes the respective stabilizer cross-element 37 and hence the pair of stabilizers 16 connected to that stabilizer cross-element 37 to move and thence the pair of legs 7 connected to that stabilizer 16 to rotate relative to the deck support frame 3 and thence raises or lowers the deck support frame 3 and the patient support surface arranged on that deck support frame. The actuators 22 may be controlled by either the patient or a care-giver. Control mechanisms for such actuators are well known and may be either a foot operated pedal, control panel on the side of the bed, remote control or other control mechanism. Suitable actuators are well known and are therefore not described in detail in this application. They may be hydraulic, electric or pneumatic. An example of hydraulic actuators controlling the height of a deck is described in EP 2 181 685 and WO 2004/021952.
[0039] Referring to FIG. 1 , the deck support frame 3 is formed by three sides of a rectangle and comprises parallel side elements 24 connected at their head ends by a head frame element 25 . In the described embodiment there is no foot frame element closing the rectangle other than the foot board (not shown) when that is attached to the foot board plates 34 (not shown) but one could be provided if appropriate. One of the known patient support deck arrangements such as that described in EP 2 181 685 and WO 2004/021952 may be secured to the patient support frame.
[0040] As shown in, for example, FIG. 4 , the side rail elements each comprise a hollow channel element open, along at least a portion of its length, on its lower side 27 . The channel element is a modified inverted U-shaped channel in which a portion of the bottom edges 28 are lipped such that the sides of the channel extend partially across the bottom of the inverted U-shaped channel.
[0041] The upper end of each leg is connected to two rollers 29 . The rollers 29 are supported on axles 30 running through the leg 7 and can rotate relative to the leg 7 . The upper end 31 of each leg passes through the gap or space 32 in the bottom of the channel elements 24 defining the sides of the deck support frame. The rollers 29 each engage the inner surface of the channel element.
[0042] Referring to FIGS. 2 and 3 , when the actuators 22 extend their respective rods 23 together to move the deck support frame 3 from a lowered position (see FIG. 3 ) to a raised position (see FIG. 2 ), the stabilizer element moves in direction E and pivots about its upper pivot. At the same time, the leg element pivots in direction F with its respective guide element moving in direction D1. As the guide element moves in direction D1 while the deck support surface is being raised, the respective set of rollers 29 roll relative to the respective channel element 24 .
[0043] When the actuators 22 retract their respective rods 23 together to move the deck support surface from a raised position ( FIG. 2 ) to a lowered position ( FIG. 3 ), the stabilizer element moves in direction G and pivots about its upper pivot. At the same time, the leg element pivots in direction H with its respective guide element moving in direction D2. As the guide element moves in direction D2 while the deck support surface is being raised, the rollers roll relative to the channel element.
[0044] Movement of the legs 7 and associated rollers 29 brought about by extension of the actuator rod to raise the deck support frame, pushes the rollers against the inner surface of the top of the respective channel element 24 so the roller rolls against that inner top surface of the channel. When the deck support frame is lowered by retraction of the actuator rod, the weight of the deck support frame and the patient support surface and patient supported thereon presses the inner top surface of the channel 24 against the respective rollers so that again the rollers roll along that top inner surface.
[0045] The channel 24 is provided along a substantial part of its length with a lip portion 28 welded or otherwise attached to each of the bottom edges of the two sides of the channel element. This helps hold the rollers in place and, if the patient support deck is lifted manually or otherwise than using the actuators, pushes up against the bottom of the rollers such that they roll against the lipped bottom edges 28 .
[0046] Moving the deck support frame into the Trendelenburg position or reverse Trendelenburg position is not illustrated in the Figs. However, it is achieved by having one of the leg assemblies in the raised position and the other in the lowered position and is otherwise the same as for lowering or raising the whole height of a substantially horizontal deck support frame. For the Trendelenburg position the foot end is raised to be about 15-30 degrees above the head end, whereas in the reverse Trendelenburg the head end is raised to be above the foot end.
[0047] In a one embodiment of the patient support apparatus according to the present disclosure, at least one of the castors and/or castor devices at each of the foot and head ends of the apparatus are provided with a brake assembly with a brake lever as described in, for example, U.S. Pat. No. 7,703,157 and arranged to be contacted and pressed down by the lower surface of the channel element to lock or brake the respective castor or castor device when the respective portion of the deck support frame is lowered.
[0048] Each of the castors includes a braking mechanism. FIGS. 5 to 7 show how a braking mechanism of the type used in castors of the type supplied by Tente as parts reference 5944 USC125 R36 may be incorporated in an embodiment according to the present disclosure. In such castors, the castor wheels 38 are braked when a pliable braking element 39 is squeezed down by a braking surface 40 so that the sides of the braking element contact and push against the sides of the castor wheels. An alternative braking element is shown in U.S. Pat. No. 7,703,157 in which braking is by means of a floor engaging element which is pushed into contact with the floor when the braking surface is ousted downwards. Any castor with an actuator mechanism operable by being pressed down or contacted may be used.
[0049] The braking surface 40 at the foot ends of the bed is pushed downward by the action of a braking lever 41 which may be actuated by, for example, the foot of a care giver on, as is shown in FIGS. 5 to 7 , by contact with the underside of the channel element 24 as the bed is lowered to the lowermost position. The use of a guide element 8 which moves inside a channel 24 allows one to position the longitudinal channel 24 closer to the edges of the bed than is possible with the previous arrangements with a guide element on the outside of a channel. This means that the channel or longitudinal rod 24 can be positioned so it moves in a place sufficiently close to the wheels to itself directly engage the brake lever 41 .
[0050] The brake surfaces (not shown) of the head end castors are connected to a respective foot end braking levers 41 by a rod element running inside each of the lower rail elements 35 . Movement of the braking lever 41 causes the rod to rotate and hence push the braking surfaces associated with the head end castors to move and hence brake or release the head end castors.
[0051] Although certain illustrative embodiments have been described in detail above, variations and modifications exist within the scope and spirit of this disclosure as described and as defined in the following claims. | A patient support apparatus includes a frame having a first portion that is movable between a raised position and a lowered position to change an elevation at which a person is supported above a floor. Castors are coupled to the frame and are configured to rest upon the floor. An actuator is movable between a brake position in which at least one castor of the castors is braked and a release position in which the at least one castor is released. As the first portion of the frame is moved to the lowered position, the first portion automatically engages the actuator and moves the actuator to the brake position thereby to automatically brake the at least one castor. | big_patent |
This application is a continuation, of application Ser. No. 849,446, filed 4/8,86 now abandoned.
The present invention relates to a skin reflectance measuring apparatus.
BACKGROUND OF THE INVENTION
The measurement of skin reflectance finds a particular application in pathology and in cosmetology. In particular, skin reflectance may be associated to other parameters such as the rate of secretion of sebum. The measurement of reflectance then becomes useful in the study of seborrhea. It may also present an advantage for studying other skin diseases such as lichen, SSM. . . . In cosmetology, the invention finds an application in measuring the effect of products known as "anti-reflectance" products for greasy skins, particularly for making efficiency-aimed tests. Another application of the present invention could be the grading of different types of skins.
Various methods and devices already exist for measuring surface reflectance, for example in the industry of paints and varnishes, in order to determine the characteristics of reflection of coated surfaces. It has also been proposed to use reflectance measurement to determine a surface finish.
All said known methods and processes which are used in industry are not applicable to the measurement of skin reflectance.
A first problem to be solved with this particular application is the problem of influence of color. Indeed, with the known devices which can only measure the specular reflection, the results obtained for different surfaces are only comparable if the surfaces are all of the same color.
To overcome the effect of color, it has been proposed to substitute to the specular reflection absolute measurement, a relative measurement between specular reflection and diffuse reflection. However, the known devices using such relative measurement remain inappropriate for measuring skin reflectance.
Indeed, the apparatuses used in industry, generally comprise optical systems with focusing lenses which require an accurate positioning of the measuring apparatus with respect to the surface of which the reflectance is being measured. It is then necessary for said surface to be flat and for the measuring area to be, in general, of relatively large dimensions.
Yet, in the case of the skin, the measuring area has to be relatively small in order to keep the characteristics of the skin uniform in that area and to make the measurement on as flat a surface as possible, without changing the characteristics to be measured by a flattening of the skin.
It is also important to have a measuring apparatus which is easy to handle and requires no higher accurate positioning with respect to the skin.
SUMMARY OF THE INVENTION
It is therefore the object of the present invention to propose a reflectance measurement apparatus which is specifically adapted for measuring the reflectance of the skin.
This object is reached with an apparatus which, according to the invention, comprises:
a probe comprising a casing of which one face, which will be in contact with the skin, is provided with an aperture,
a flexible connection in fiber optics, comprising at least three optical conductors which, at a first end, are secured in the casing of the probe such as to face the aperture thereof, the first and second conductors having their first end portions directed respectively in a first and a second directions which are symmetrical to each other with respect to an axis extending normally through the aperture, while the third conductor has its first end portion directed in another direction than said second direction,
a measuring device comprising: light emitting means optically coupled to a second end of said first conductor; light receiving means optically coupled to a second end of said second conductor to produce a first signal representing the specular reflection, and to a second end of said third conductor to produce a second signal representing part of the non-specular or diffuse reflection; and processing means connected to said light emitting and receiving means, and provided with correcting means to compensate for variations in the emitted light and for the influence of ambient light, said correcting means producing a relative reflectance signal from the measured values of specular reflection and diffuse reflection, and
a display device receiving the reflectance signal to indicate the amplitude of said signal.
The structure of the measuring apparatus according to the invention, such as defined hereinabove, with a probe connected to a measuring device via a flexible connection in fiber optics, presents many advantages.
The use of fiber optics having their end secured inside the casing of the probe in a relatively fixed configuration, permits the miniaturization of the probe. It becomes, as a result, possible to carry out measurements on reduced surfaces and, in particular, on surfaces less than 1 cm2, for example surfaces between 10 and 50 mm2. This also makes the apparatus readily usable since the probe is of reduced dimensions and is connected to the rest of the apparatus by way of a flexible connection. Such readiness of use is further increased due to the fact that, contrary to the systems using optical means with beam focusing lenses and requiring an extremely accurate positioning of the apparatus on a flat surface, the apparatus according to the invention can tolerate a few degrees of deviation of relative position between the probe and the skin surface.
The correction of variations in the intensity of the emitted light and in the effect of the ambient light makes it possible to obtain a very accurate measurement without very strict operational conditions.
The means for correcting variations in light intensity can be in the form of a circuit for regulating a source of light of the emitting means, using servo-control means.
As a variant, means may be provided for measuring the intensity of the light produced by the emitting means in order to compensate for any variations occurring in that intensity, directly at the level of the signals produced by the reflected light receiving means.
The compensation for the effect of ambient light is advantageously achieved by conducting measurements according to the "synchronous detection" principle, namely by carrying out cycles of measurements during which the specular reflection and the diffuse reflection are measured when the light-emitting means is operative and when the light-emitting means is inoperative. To control the course of said measurements and to process the results, the measuring device advantageously uses digital processing means such as a micro-computer.
It will be further noted that the display of the reflectance not only enables the operator to view immediately the value that he is seeking, but also helps in correctly positioning the probe.
The resulting reflectance is a relative value worked out from measurements of the specular reflection and of the diffuse reflection, for example the difference or the quotient between the measured values of specular and diffuse reflection. The difference is preferred to the quotient insofar as it introduces less scale distortion with respect to the judgement of the skin reflectance made by eye. A scale of reflectance may be defined from a measurement of a matt surface of reference (unit 1) and of a calibrated mirror (unit 10 n , n being an integer above 0).
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be more readily understood on reading the following description with reference to the accompanying drawings, in which:
FIG. 1 is a general diagram of one embodiment of a reflectance measuring apparatus according to the invention.
FIG. 2 is a more detailed cross-section of the probe of the apparatus shown in FIG. 1.
FIG. 3 illustrates in more detail the structure of the emitter of the light emitting means of the apparatus shown in FIG. 1.
FIG. 4 is a diagram of the circuits of emitting and receiving means and of the interface circuit of the apparatus shown in FIG. 1.
FIG. 5 illustrates the variation in time of the output voltage of the receiving means during a measuring cycle.
FIGS. 6 and 7 are flow charts of the operations carried out under the control of the digital processing means for, respectively measuring and calibrating.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The apparatus illustrated very diagrammatically in FIG. 1. comprises a probe 10, a measuring device 30 and a flexible connection 20 in fiber optics connecting the measuring device to the probe 10.
The probe 10 is designed to be placed in contact with the skin P in order to light up the part of the skin surface requiring to be examined.
The connection 20 comprises three optical channels 21, 22, channel 21 conveys to the probe the light produced from a light-emitting device 31 in order to illuminate the skin surface to be examined. Channel 22 transmits to a receiving device 32 the light reflected specularly (normally) by the examined part of surface whereas channel 23 transmits to the receiving device part of the light reflected in non-specular or diffuse manner. In the illustrated example, the diffuse reflection is measured in the direction opposite to the direction of incidence of the light on the surface to be examined. Channels 21 and 23 can therefore be re-grouped, at least at their end portions connected to the probe, into a bi-directional optical cable.
The emitting 31 and receiving 32 devices are connected to a control and processing device 33 via an interface circuit 34.
Said device 31 comprises means of regulating the intensity of the emitted light and is operated by control signals issued by the processing device 33.
The receiving device 32 comprises photo-electrical transducers working out electrical signals representing the normal reflection and the diffuse reflection. Said signals are transmitted to processing device 33 through the interface circuit 34, this transmission being achieved under the control of signals produced by the processing device.
In conventional manner, said processing device 33 comprises memory circuits 35, an arithmetical and logical unit 36 and interface circuits 37 permitting the connection with a display device 38, such as a cathod ray tube, with a keyboard 39 and with a printer 40. The processing device may be constituted by any of the existing micro-computers, therefore it will not be described any further herein.
Supply of the different circuits of the apparatus is ensured by supply circuits (not shown).
FIG. 2 is a diagrammatical cross-section showing the probe 10 in more details.
Said probe 10 comprises a casing 11 of which the front face 12 is provided in its center with an opening 13 such as of circular shape. The casing also presents two connecting parts 14, 15 in which are respectively secured the ends of channels 21 and 23 and the end of channel 22. Channels 21, 23 are re-grouped at their ends into a bidirectional optical cable 24 provided with an end socket 25 screwed into the connecting part 14, whereas optical cable 26 forming the channel 22 is provided with a ring 27 and is inserted in a tubular guide 17 housed in the connecting part 15.
The axis of optical cable 24, namely the axis of connecting part 14, traverses the center of aperture 13 and is inclined with respect to the perpendicular N to the front face 12 of an angle i, said angle i corresponding to the angle selected for the incidence under which the part of skin surface to be examined is illuminated. In the illustrated example, the angle of incidence i is equal to about 45°, but another value could also be selected. The axis of optical cable 26, namely the axis of connecting part 15 is symmetrical to the axis of cable 24 with respect to the perpendicular N traversing the center of aperture 13 since channel 22 is designed to pick up the normally reflected light.
Cables 24 and 26 are secured to the casing 11 in such a way that the ends of the fiber optics composing them are at predetermined distances d1 and d2 from the center of aperture 13. Adjustment of the position of the end of cable 24 is achieved by interposition of wedges 16 between the socket 25 and the connecting part 14 whereas the end of cable 26 is fixed in the required position in the guide 17 by a locking screw 18 traversing the connecting part 15 and resting against the ring 37. By way of example, distances d1 and d2 are about 20 mm.
The use of a flexible connection composed of fiber optics of which the ends are secured to the probe, presents several advantages. For example, the probe may be small, its overall dimensions being determined by the connecting means of the optical cables. Moreover, the probe has no optical elements such as lenses which require high positioning accuracy.
The measuring area, determined by the size of aperture 13 may then be small enough to allow significant measurements over a surface with as little rigidity and uniformity as the skin. For example, the surface of the measuring area may be between 10 and 50 mm2, such as about 25 mm2. The miniaturization of the probe and its flexible connection with the rest of the apparatus, also allow ready handling for taking measurements over different areas of the skin surface.
FIG. 3 diagrammatically illustrates the structure of the emitter of the light emitting device 31.
Said emitter comprises a casing 311 to which is connected the starting end of optical channel 21. Said casing 311 is provided with walls 312 used as support for the different elements housed in the casing. The light source is a lamp 314 with tungsten filament. The beam produced by the lamp is focussed by means of a lens 315 in order to obtain an adequate light intensity at the input 21a to optical channel 21. An infrared filter 316 may be interposed between the lamp 314 and the input to optical channel 21 in order to carry out measurements within the field of the infrared-free visible light. Two photodiodes 317, 318 are placed on both sides of the input to optical channel 21 so as to supply signals representing the light intensity at that input. Photodiodes 317 and 318 are connected to a circuit 319 for regulating the light intensity produced by lamp 314.
Regulation circuit 319 (FIG. 4) comprises a source of voltage consisting of a transistor T1 of which the collector is at potential +V of a supply source and the emitter is connected to a terminal at the reference potential (earth) via the lamp 314. Photodiodes 317, 318 are connected to an amplifier circuit AMP which delivers a voltage V MES representing the real intensity of the light beam applied to the input of channel 21. Voltage V MES is compared to a reference voltage V REF , supplied by a voltage-adjustable generator SV; the comparison is carried out by means of a differential circuit CP which delivers a voltage V COM which is function of the difference between V REF and V MES . The voltage V COM is applied to the base of T1 and determines the voltage in the lamp 314 so as to return towards zero the difference between voltages V REF and V MES .
The circuit 319 receives a start control signal SCA applied via a resistor R1 to the base of a transistor T2. The emitter thereof is connected to earth whereas its collector is connected, on the one hand, to the voltage source +V via a resistor R2 and, on the other hand, to the base of a transistor T3 via a resistor R3. Transistor T3 has its emitter-collector circuit connected between the base of T1 and the earth. When the start control signal is at a level between the triggering signal of transistor T2 (SCA=0, or low logic level), transistor 2 is in the OFF state, but transistor T3 is in the ON state, bringing the base of T1 to the earth potential; lamp 314 is switched off. When the ON control signal exceeds the triggering threshold of T2 (SCA=1, or high logic level), transistor T2 is turned to the ON state, this keeping T3 in the OFF state and lamp 314 is switched on, the intensity of the current through the lamp being determined by V COM .
FIG. 4 also shows the circuit of receiving device 32.
Two photodiodes 322, 323 receive light beams transmitted respectively by optical channels 22, 23. Diodes 322, 323 are silicon diodes connected in reverse. The cathodes of diodes 322, 323 are connected to the middle point of a voltage divider formed by two resistors R4, R5 connected in series between the earth and a terminal of potential V. Diodes 322, 323 thus produce a voltage substantially proportional to the intensity of the picked up light beams. The anodes of diodes 322, 323 are connected to two input contacts of an analog switch 324 of which the output contact is connected to the input of a logarithmic amplifier APL producing an analog signal S RFX representative of the specular reflection or of the diffuse reflection, depending on the position of switch 324. The use of a logarithmic amplifier procures greater dynamics. Moreover, the human eye constituting a logarithmic type receiver, the measuring apparatus makes it possible to come closer to the visual judgement which it is required to quantify.
The receiving device receives a switch control signal SCM controlling the position of the switch. For example, when signal SCM has a high logic level (SCM=1), switch 324 connects photodiode 232 with amplifier APL to measure the specular reflection, whereas when signal SCM has a low logical level (SCM=0) switch 234 connects photodiode 233 to amplifier APL to measure the diffuse reflection.
Interface circuit 34 comprises an analog-to-digital converter CAN which receives the signal S RFX to convert it in the form of a digit word N RFX of n bits. A connection circuit PIA ("parallel interface adapter") is interposed between the converter CAN and the micro-computer 33. Said circuit PIA also transmits signals SCA and SCM as well as the control signals of converter CAN. Circuit PIA is controlled in known manner by control signals produced by the micro-computer.
The emitting and receiving devices are controlled to produce a reflectance measurement from the specular and diffuse reflection values; in the illustrated case, the worked out value represents the difference between the specular reflection intensity and the diffuse reflection intensity. Moreover, in order to take into account the influence of ambient light, the reflection is measured according to a principle of "synchronous detection" namely by alternately controlling the switching on and off of the light source.
The light flux ΦS carried by channel 22 (specular reflection is composed of flux ΦSp effectively reflected by the skin, of flux ΦSa coming from the outside (ambient light) and from leaks from the detectors, and of flux ΦSs sent back by the casing of the probe. Likewise, the light flux ΦD carried by channel 23 (diffuse reflection) comprises components ΦDp, ΦDa and ΦDs.
During a measuring cycle, the flux ΦDa, ΦSa are successively measured by actuating switch 324, the lamp being switched off, then after switching the lamp on, the flux ΦS and ΦD are measured successively by actuating the switch 324.
The desired reflectance Re is equal to:
Re=ΦSp-ΦDP=(ΦS-ΦSa-ΦSs)-(ΦD-ΦDa-ΦDs)/K,
K being a corrective factor taking into account the geometry of the probe and of the optical channels 22, 23 since the reflectance is assessed by differences between intensities of the specular and diffuse reflections, and not by differences between flux.
The quantities ΦSs, ΦDs and K are determined by calibration. By placing the probe before a light trap (instead of the skin) ΦSa+ΦSs and ΦDa+ΦDs are measured, when the lamp is switched on, and ΦSa and ΦDa are measured when the lamp is switched off, wherefrom ΦSs and ΦDs are deduced. The value of K is thereafter determined by placing the probe before a matt surface used as a reference of nil reflectance (Re=0) by measuring φD, ΦS, ΦDa and ΦSs, and by calculating:
K=(ΦD-ΦDa-ΦDs)/(ΦS-ΦSa-ΦSs).
A scale coefficient SC is also determined by placing the probe before a reflecting surface of reference such as a calibrated mirror at 80% reflection, the reflectance being then arbitrarily fixed to a predetermined value ReM (for Example 1000). After measuring φD, ΦS, and ΦSs, the coefficient SC is determined by dividing ReM by the quantity:
(ΦS-ΦSa-ΦSs)-(ΦD-ΦDa-ΦDs)/K.
The values of ΦSs, ΦDs, K and SC, determined by calibration, are stored in the memory circuits 34 of the micro-computer.
FIG. 5 shows the variation in time of voltage S RFX in output of logarithmic amplifier APL. The times t.sub.ΦSa, t.sub.ΦDa, t.sub.ΦD, t.sub.ΦS correspond to the times of measurement of quantities ΦSa, ΦDa, ΦD and ΦS. The times t A and t E correspond to the switching on and switching off of the lamp, whereas times t S and t D correspond to the times of actuation of switch 234, respectively, towards photodiode 232 (specular reflection) and towards photodiode 233 (diffuse reflection).
The successive measuring cycles are performed under the control of the micro-computer. The duration of one cycle may be less than 1 sec., for example around 0.7 sec., said duration being for example function of the times necessary for the stabilization of the lamp when this is switched on and off. The values of reflectance Re calculated during successive measurement cycles are displayed as successive positions of a cursor on the screen of tube 38. The operator can thus correct any incorrect positioning of the probe by observing the position variations in y-axis of the cursor when moving the probe slightly. Instantaneous display of the reflectance calculated value thus contributes to positioning the probe. The reflectance value finally retained may be a mean value worked out from the results of a predetermined number of measurement cycles. Said final value may be edited on the printer 40 and is displayed on the screen. The resulting reflectance value is recorded in a computer file which may contain other information concerning the patient whose skin is being examined, the date of examination and any special conditions of examination. The recorded information may be edited on paper via the printer, at the operator's request.
The main programme including the operations of initialization of the system and the subroutines of recording on file and file readout are not specific phases of the proposed application; therefore they are not explained hereinafter in details.
The measuring and calibrating operations use programmes such as per flow-charts illustrated in FIGS. 6 and 7.
The measuring operation consists in the following phases:
initialization of the graph, and tracing of the outline of the screen with a view to displaying the measurement results as a curve representing the variation of the reflectance (phase 400);
positioning of the cursor in abscissa L=1 on the screen (phase 401);
scanning of the keyboard (phase 402);
if the operator, by actuating the keyboard, requests the exit of the subroutine (test 403), return to the main programme;
if the operator, by actuating the keyboard, requests an integration on the reflectance values obtained during the successive cycles of measurement (test 404), a subroutine (420) is called during which a test is carried out on the positioning of an averaging indicator (E=-1!), so as, in the affirmative, to arrive at end of averaging, to return indicator E to zero, and to return to the programme, and, in the negative, to bring sum S and parameter N to zero, to position E to -1 and to return to the programme;
measurement of the flux ΦDa, the signals SCA and SCM being in zero position, and readout of the corresponding digital value (phase 405);
switching from channel 23 to channel 22 by placing SCM in position 1, measurement of flux ΦSa and readout of the corresponding digital value (phase 406);
switching on of the lamp by bringing SCA to position 1, measurement of the flux ΦS and readout of the corresponding digital value (phase 407);
switching from channel 22 to channel 23 by bringing SCM to position 0; measurement of ΦD and readout of the corresponding digital value (phase 408);
calculation of Re from the readout values of ΦDa, ΦSa, ΦS and ΦD, and of the pre-recorded values of ΦSs, ΦDs, K and FE (phase 409)
if an integration is called (test 410) calling of a summation subroutine 430 including updating of sum S (S=S+Re), incrementing of N (N=N+1), calculation of an "instant mean value" of reflectance M i (Re)=S/N, control of the display on the screen of the digital value of M i (Re) and return to the programme;
editing of the digital values of Re or, optionally, of M i (Re)(phase 411);
graphic display of the digital value of Re by control of the ordinate of the cursor on the screen (phase 412);
incrementing of the abscissa of the cursor on the screen: L=L+1 (phase 413);
if the value of L is equal to the maximum abscissa possible L MAX (test 414), clearing of the screen (phase 415) and return to initialization of the graph, if not, return to phase 402;
The calibration operation consists in the following phases:
recall of existing constant values (phase 5 1)
passage to first constant value (phase 502);
display on the screen of a message (phase 503) for placing the probe before the surface corresponding to the constant value to be determined (light trap, matt surface of reference, reference mirror);
scanning of the keyboard (phase 504);
if the operator, by actuating the keyboard, requests the exit of the subroutine (test 505), return to the main programme without changing the calibration;
for every constant to be determined K1 to K4 (K1=ΦSs, K2=ΦDs, K3=K and K4=SC), performance of M successive cycles of measurement, for example 10 cycles, (phase 506) each one including:
measurements of flux ΦDa, ΦSa, ΦS and ΦD (phases 405 to 408 of the aforesaid measuring programme):
the calculation of quantities R1=ΦS-ΦSa,
R2=ΦD-∠Da, R3=(R2-K2)/(R1-K1), R'4=(R1-K1)-(R2-K2)/K3
and
R4=ReM/R'4;
updating of sum Si by:
Se=Si+Ri (i=1, 2, 3 or 4);
and updating of sum ΣI by
Σi=Σi+R.sup.2 (i=1, 2, 3 or 4);
calculations of mean value and standard deviation for every constant (phase 507), namely mean value Xi=Si/M, standard deviation Vi=Σi/m-Xi 2 and reduced standard deviation
Zi=⃡Vi/Xi: (i=1, 2, 3 or 4);
display of calculated mean value X (phase 508);
if the reduced standard deviation is greater than a predetermined threshold (test 509), it is displayed on the screen, if not, then direct passage to the next phase;
consultation by the operator (phase 510)
scanning of the keyboard (phase 511)
if the operator, by actuating the keyboard, requests a new assessment of the same constant (test 512), return to phase 503;
if the operator, by actuating the keyboard, requests that the new constant be kept (test 513), then Ki=Xi (phase 514) and passage to the next constant (phase 515);
if the operator, by actuating the keyboard, refuses the value Xi (test 516), then the actual value of the constant is kept (phase 517) with passage to the next constant (phase 515);
if the operator, by actuating the keyboard, requests the exit (test 518), then return to the main programme without modifying the calibration;
when passing to the next constant (phase 515) and if the four constants have not yet been calculated (test 519), return to phase 503;
if all the constants have been calculated, exit with modification of the calibration and return to the main programme.
Tests have been conducted with a mesuring apparatus suc as described hereinabove by using a scale of reflectance Re ranging from 0 for the matt surface of reference to 1000 for the reflecting surface of reference (mirror with 80% reflection).
The measurements taken on 34 people have given reflectance values within a range of 8 to 12.5 for the fore-arm and from 6 to 13.9 for the forehead.
In the case of people (7 cases) whose skin appears to be greasy to the eye, the mean reflectance value measure on the forehead has been 11.7, to be compared with the general means value of 9.56 obtained from measurements taken in 32 random cases. Moreover, measurements taken on five subjects have shown a deviation of 5.4 between the mean reflectance values obtained before and after application of "Vaselin" on the fore-arm.
These results show the effective correlation between the visual aspect of reflectance and the measurements taken, thereby justifying the use of the measuring apparatus according to the invention as an "objective"means of quantifying the reflectance of the skin. | A probe comprising a casing of which one face which will be in contact with the skin is providied with an aperture, is connected to a measuring device by means of a flexible connection in fiber optics comprising at least three optical conductors which, at a first end, are secured in the casing of the probe such as to face the aperture thereof, the first and second conductors having their first end portions directed respectively in a first and a second directions which are symmetrical to each other with respect to an axis extending normally through the aperture, while the third conductor has its first end portion directed in another direction than said second direction. | big_patent |
BACKGROUND OF THE INVENTION
This invention relates to dental apparatus and more specifically to dental cleaning and massaging apparatus.
Research has clearly shown that the brushing of teeth as commonly practiced does not provide adequate cleaning of the teeth and the area around the teeth to prevent caries and peridental disease. Toothpicks and dental floss have been used to augment brushing. However, even the use of toothpicks and/or dental floss in combination with brushing does not provide the cleaning necessary to adequately guard against caries and peridental disease.
In recent years hydro-therapy devices that provide a higher degree of cleansing, particularly cleansing of the gingival crevices, have been devised and introduced on the market. This invention provides for the hydraulic cleaning of the teeth of a person and at the same time provides for the massaging of the gums. Research has also shown that gentle non-damaging massaging of the gums promotes dental health.
SUMMARY OF THE INVENTION
The apparatus of this invention provides a relatively simple and highly effective means for cleaning teeth and the gingival crevices and for massaging the gums. The apparatus comprises a mouthpiece having upper and lower channel members that fit over the upper and lower teeth, respectively, and fit snugly against the respective gums. The channel members are joined by a membrane structure and pneumatic means are provided to move the upper and lower channel members relative to the upper and lower gums, respectively, to thereby massage the gums. Hydraulic means to clean the teeth and gingival crevices and to lubricate the gums during massaging are also provided.
BRIEF DESCRIPTION OF THE DRAWING
A complete and full understanding of the invention can be obtained from the following detailed description when read in conjunction with the annexed drawing in which:
FIG. 1 is a pictorial representation of the invention;
FIG. 2 is a top view of the mouthpiece of the invention;
FIG. 3 is a cross-sectional view of the mouthpiece along the line 3--3 of FIG. 2;
FIG. 4 is a cross-sectional view of the mouthpiece taken along the line 4--4 of FIG. 2 with the air-socks of the pneumatic means inflated; and
FIG. 5 is the cross-sectional view of FIG. 4 with the air-socks deflated.
DESCRIPTION OF THE INVENTION
Referring to the drawing, the invention comprises a mouthpiece 1 having an upper channel member 2 and a lower channel member 5 (FIGS. 3, 4 and 5). Upper channel member 2 is essentially identical to the upper mouthpiece worn by a boxer but modified according to this invention; and, similarly, lower channel member 5 is essentially identical to the lower mouthpiece worn by a boxer but modified according to this invention. This upper channel member 2 is designed to fit over the upper teeth of the user and to snugly fit against the upper gum and lower channel member 5 is designed to fit over the lower teeth of the user and to fit snugly against the lower gum. Upper channel member 2 and lower channel member 5 are made of a relatively soft but semi-rigid material. Holes 6 (see FIGS. 4, 5 and 6) are cut through both legs or sides of upper channel member 2 and lower channel member 5. The function of these holes will be described later herein.
A first or outer membrane 7 extends from upper channel member 2 downward to lower channel member 5 as is more clearly shown in FIG. 3. As shown in FIG. 3, outer membrane 7 is integrally formed with the uppermost part of upper channel member 2 at one end and is integrally formed with the lowermost part of lower channel member 5. Instead of being integrally formed with upper and lower channel members 2 and 5, respectively, outer membrane 7 can be and from a production standpoint preferably is secured by any suitable means such as a non-toxic adhesive at one end to upper channel member 2 and at its other end to lower channel member 5. A second or inner membrane 8 extends from the uppermost part of upper channel member 2 downward to the lowermost part of lower channel member 5 (see FIG. 3). Again, the top part of second membrane 8 is shown in FIG. 3 as being integrally formed with upper channel member 2 at one end and with lower channel member 5 at its other end but can be and preferably is secured to the uppermost part of upper channel member 2 at one end and to the lowermost part of lower channel member 5 at its other end by any suitable means and is a non-toxic adhesive. Outer membrane 7 and inner membrane 8 are conveniently made of a relative soft material that is somewhat elastic. From the foregoing description of outer member 7 and inner membrane 8, it is apparent that the area between the uppermost part of upper channel member 2 and the lowermost part of the lower channel member 5 is enclosed by means of membranes 7 and 8. Although it is not clearly visible in FIGS. 1 and 2, membranes 7 and 8 are brought around the back of upper and lower channel members 2 and 5 such that the closed area formed by membranes 7 and 8 is a sealed area.
A plurality of the bite blocks 10 are located in both upper and lower channel members 2 and 5. Three bite blocks 10 are shown in upper channel member 2. An identical number of bite blocks are located in lower channel member 5 directly below bite blocks 10. One of these bite blocks, the bite block 11, located in lower channel member 5 is shown in FIGS. 3, 4 and 5. Referring specifically to FIGS. 3, 4 and 5, a rod or post 12 has one end secured to or integrally fabricated with bite block 10. The other end of post or rod 12 is secured to or integrally fabricated with the block 13. A rod or post 14 has one end secured to or integrally fabricated with bite block 11 and its other end is integrally fabricated with or secured to block 13. A hole 15 is cut through block 13. All three bite block structures are identical. Thus, all three bite block structures comprise a bite block 10 in upper channel 2, a bite block 11 in lower channel 5, a post or rod 12, a block 13 having a hole 15 and a post or rod 14. While the number of bite block structures provided is not critical, it will be obvious later herein from the description of the operation that at least three bit block structures should be provided.
A hose or tube 16 is positioned between the bottom of upper channel member 2 and the top of lower channel member 5. The hose or tube 16 is shaped to extend along the entire bottom and top surfaces of upper channel members 2 and 5, respectively, as is shown in FIG. 2. Hose or tube 16 is threaded through holes 15 of blocks 13 as shown in FIGS. 3, 4 and 5. A plurality of air-sacks 17 are integrally formed along tube or hose 16 as shown in FIG. 2. Conveniently, air-sacks 17 are areas formed along tube or hose 16 that are more elastic than the balance of hose 16 so that air-sacks 17 will expand when inflated by air while the balance of hose or tube 16 remains substantially unchanged when air-sacks 17 are inflated or deflated. While the number of air-sacks provided is not critical, four air-sacks located as shown in FIG. 2 is probably the minimum number required for satisfactory operation. More air-sacks 17 could be provided or for that matter the entire hose or tube 16 could be made of the same material as air-sacks 17 so that the entire tube or hose 16 would expand when inflated except, of course, in the area where hose or tube 16 passes through the holes 15 of blocks 13. Air-sacks 17 are secured to upper and lower channel members 2 and 5 by a suitable adhesive or the like.
Referring specifically to FIGS. 1 and 2, a hose or tube 18B has one end secured to or is integrally fabricated with hose 16. The other end of hose 18B is secured to the coupler 18A. Coupler 18A is secured to and passes through membrane 7 such that one end, the end secured to hose 18B, is located in the enclosed area formed by membranes 7 and 8 and the other end extends slightly beyond the outer surface of membrane 7. A hose or tube 19B is secured along the outside of membrane 7 as shown more clearly in FIG. 1. Both ends of tube 19B are open. A coupler 19A, one end of which communicates with the inside of hose 19B, is secured to hose 19B at approximately the mid-point of hose 19B. The other end of coupler 19A extends slightly beyond the outside surface of hose 19B.
A hose or tube 20B is located in the area formed by membranes 7 and 8. One end of hose 20B extends through membrane 8. This end of hose 20B conveniently and preferably is flush with the outside surface of membrane 8. The other end of hose 20B is secured to one end of the coupler 20A. Coupler 20A is secured to membrane 7 such that one end of coupler 20A, the end secured to hose 20B, is located in the area formed by membranes 7 and 8 and the other end extends slightly beyond the outside surface of membrane 7.
A coupler 21A is secured to membrane 7 such that one end of coupler 21A extends into the enclosed area formed by membranes 7 and 8 and the other end extends slightly beyond the outer surface of membrane 7. Seals are provided around couplers 18A, 20A and 21A where they pass through membrane 7 so that a fluid tight seal is provided between membrane 7 and each of the couplers 18A, 20A and 21A. Similarly, a seal is provided between hose 19B and the area adjacent the end of coupler 19A that communicates with the inside of hose 19B so that a fluid tight seal is provided between hose 19B and this end of coupler 19A.
One end of each of the hoses or tubes 18, 19, 20 and 21 is coupled to a control box 22. The other end of hoses 18, 19, 20 and 21 are coupled to couplers 18A, 19A, 20A and 21A, respectively. The end of each of the hoses 18, 19, 20 and 21 that is coupled to its mating coupler 18A, 19A, 20A and 21A, respectively, is preferably provided with a mating connector, not shown in the drawing, such that hoses 18, 19, 20 and 21 can be quickly coupled to and uncoupled from couplers 18A, 19A, 20A and 21A, respectively. Any type of suitable well known quick connect and disconnect coupling arrangement can be used to couple hoses 18, 19, 20 and 21 to their respective couplers. In addition to quick disconnect, the couplers permit one control unit 22 to be used interchangeably with a plurality of mouthpieces. Three ON-OFF switches, the switches 23, 24 and 25, are provided on control box 22. The outlet hoses 26 and 27 have one end coupled to control box 22. Control box 22 is provided with a remote control device 28 that is sized and shaped to be conveniently held in the hand of the user of the apparatus of this invention. Remote control device 28 is provided with the switches 29, 30 and 31.
The apparatus of this invention operates as follows: The user inserts mouthpiece 1 into his or her mouth such that upper channel member 2 fits over the upper teeth and snugly against the upper gum and lower channel 5 fits over the lower teeth and snugly against the lower gum. Control box 22 is then activated to provide either air pulses and water or air pulses alone or water alone. The air pulses are provided to air-sacks 17 from control box 22 through hose 18, coupler 18A, hose 18B and hose 16. Control box 22 is provided with an air pump that operates cyclically to alternately provide pulses of air with periods of no air between the air pulses. When air pulses are provided, air-sacks 17 are inflated and during the period between air pulses air-sacks 17 are deflated. The elasticity of air-sacks 17 and the elasticity of membranes 7 and 8 forces the air out of air-sacks 17 through hose 16, hose 18B, coupler 18A and hose 18 during the period between air pulses. Instead of relying solely on the elasticity of air-sacks 17 to drive out the air, the pump of control box 22 could alternately pump air in and such air out; thereby ensuring positive inflation and deflation of air-sacks 17. In any event, control box 22 must operate such that air-sacks 17 are alternately inflated and deflated.
Referring to FIGS. 4 and 5, FIG. 4 shows a single air-sack 17 in its inflated condition and FIG. 5 shows an air-sack 17 deflated. All of the air-sacks 17 are inflated or deflated at the same time. When the air-sacks 17 are inflated, upper channel member 2 rides up on the upper gum and lower channel member 5 rides down on the lower gum. When air-sacks 17 are deflated, the upper channel member 2 will ride down on the upper gum and lower channel member 5 will ride up on the lower gum. Thus, as air-sacks 17 are inflated and deflated, upper and lower channel members 2 and 5 provide a massaging action on the gums. The teeth are held in place by the bite blocks 10 and 11 so that the upper and lower channel members 2 and 5 will ride up and down on the gums with the teeth staying in place. The elasticity of the membranes and the air-sacks pulls upper and lower channel members toward each other when air-sacks 17 are deflated.
At the same time that control box 22 is providing air to massage the gums, control box 22 also provides a source of water and/or cleaning fluid through hose 21 and coupler 21A into the area formed by membranes 7 and 8. This water and/or cleaning fluid flows through holes 6 in upper and lower channel members 2 and 5 to clean and flush out the teeth and gums. This fluid is preferably introduced into mouthpiece 1 as a gentle steady stream. In addition to providing a cleaning action, the fluid serves as a lubricant during the massaging action.
Since some fluid will seep out between the gums and upper and lower channel members 2 and 5, suction hose 9 is provided on the outside of membrane 7. Suction hose 9 is coupled to control box 22 by means of coupler 19A and hose 19. Control box 22 sucks any fluid seepage out of the mouth of the user through hose 9, coupler 19A and hose 19. Similarly, hose 20B serves as a suction hose to suck out the fluid that seeps into the area of the mouth outside of inner membrane 8. This seepage is drawn out by control box 22 through hose 20B, coupler 20A and hose 20.
A source of water is provided to control box 22 by means of the hose 26. This water can be mixed with a cleaning fluid that is stored inside of control box 22. If no cleaning fluid is to be used, no such fluid will be stored in control box 22. Similarly, if only cleaning fluid is used, the source of water is cut off. Also, a mixture of water and cleaning fluid can be stored in control box 22 and hose 26 eliminated, if control box 22 is provided with a sufficiently large storage compartment for the fluid. The fluid drawn out of the mouth around mouthpiece 1 through hoses 19 and 20 is drained out of control box 22 by means of hose 27. If a drain pan is provided in control box 22, hose 27 can be eliminated.
While under most circumstances, the apparatus will be used with both cleaning fluid and with air to provide the massaging action, the apparatus can be operated such that either air only is provided or cleaning fluid only is provided, or both air and cleaning fluid are provided. Control box 22 is provided with three ON-OFF switches to provide the three modes of operation. For example, switch 23 would provide both air and water, switch 24 air only and switch 25 water only.
While the apparatus can be operated from control box 22, a remote control device 28 is preferably provided. Remote control device 28 is of such size and shape that it is easily hand held and is provided with switches 29, 30 and 31 that correspond in operation to switches 23, 24 and 25, respectively. Alternately, remote control device 28 can be and preferably is provided with a single ON-OFF pushbuttom switch with the mode of operation set by switches 23, 24 and 25. This single switch or remote control device 28 would then operate to merely activate the control box 22.
While the invention has been described with reference to a specific embodiment, it will be obvious to those skilled in the art that various changes and modifications can be made to this embodiment without departing from the spirit and scope of the invention as set forth in the claims. For example, bristles can be added to the upper and lower channels to assist the massaging action and a single coupling arrangement could be used to couple the control panel to the mouthpiece. | Apparatus for cleaning teeth and the gingival crevices and for massaging the gums is disclosed. The apparatus comprising a mouthpiece having an upper channel member adapted to fit over at least a part of the upper dentation and to snugly engage the upper gum and a lower channel member adapted to fit over at least a part of the lower dentation and to snugly engage the lower gum. The upper and lower channels are joined by a membrane means which form fluid chambers. Pneumatic means are provided to move the upper and lower channel members upward and downward over the respective gums to massage the gums. In addition water or any suitable cleaning fluid is introduced into and out of the apparatus to clean the teeth and gingival crevices and to provide lubrication for the massaging action of the pneumatic means. | big_patent |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The current application claims the benefit of and priority to Israel Patent Application No. 194519, filed Oct. 5, 2008, and incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to the field of pelvic floor reconstruction. In particular, the present invention relates to the field of pelvic floor reconstruction using implants.
BACKGROUND OF THE INVENTION
[0003] Pelvic organ prolapse (POP) is a common female problem that can have a profound impact on a woman's quality of life.
[0004] The organs in the pelvic cavity, uterus, vagina, bladder and rectum, are held in place by a web of muscles and connective tissues that act much like a hammock. When these muscles and tissues become weakened or damaged, one or more of the pelvic organs shift out of normal position and literally “fall” into the vagina.
[0005] Prolapse surgical reconstruction is performed through the vagina. During the procedure, the surgeon repositions the prolapsed organs, securing them to surrounding tissues and ligaments, and may use a synthetic non-absorbable polypropylene mesh implant.
[0006] However, the prior art surgical procedures penetrate the patient from several directions.
[0007] As well, they do not provide reliable anchoring of the mesh implant.
[0008] It is an object of the present invention to provide a reliable anchoring of the mesh implant.
[0009] Other objects and advantages of the invention will become apparent as the description proceeds.
SUMMARY OF THE INVENTION
[0010] The following embodiments and aspects thereof are described and illustrated in conjunction with systems, tools methods, and so forth, which are meant to be merely illustrative, not limiting in scope.
[0011] In one aspect, the present invention may be directed to a needle for surgical threading of a strap of an implant through a tissue, the needle comprising:
a trap for trapping the strap to the needle, while the needle may be at the accessible side of the tissue; a tip for threading the trapped strap from the accessible side to the opposing side; and a mechanism for releasing the trap, the mechanism driven from the accessible side of the tissue, thereby allowing return of the tip to the accessible side of the tissue while abandoning the strap at the threaded point, thus performing threading from the accessible side of the tissue.
The trap may comprise:
a niche, for inserting an end of the strap of the implant; and a rod, for grasping the end of the strap.
The niche may be located near the tip.
[0018] The end of the strap may comprise a looped end for inserting the rod thereinto.
[0019] According to another embodiment the rod is capable of applying physical force on the end of the strap towards the limiting wall thereof in the niche.
[0020] The mechanism for releasing the trap may be manually driven.
[0021] The mechanism for releasing the trap may comprise a cable, driven from the accessible side of the tissue, for removing the rod from the end of the strap.
[0022] The needle may further comprise an arm for driving the mechanism, the arm located outside the surgical area.
[0023] In another aspect, the present invention is directed to an anterior implant comprising:
at least two first straps for threading thereof into the arcus tendineous fascia pelvic (ATFP) ligaments; at least two second straps for threading thereof into the sacrospinous (SS) ligaments; and a loop between the second straps for anchoring thereof to the cervix.
[0027] The anterior implant may be used for reconstructing the organs selected from the group including: prolapse of the urinary bladder, the colon, the small intestine.
[0028] The anterior implant may further comprise spaces for reducing weight of the implant.
[0029] In another aspect, the present invention is directed to a posterior implant comprising:
at least two straps for threading thereof into the sacrospinous (SS) ligaments; a first loop between the straps for anchoring thereof to the cervix; and a second loop at the side opposing the straps, the second loop for anchoring thereof to the perineal body.
[0033] The posterior implant may be used for reconstructing the organs selected from the group including: the colon, the small intestine, the uterus.
[0034] The posterior implant may further comprise spaces for reducing weight of the implant.
[0035] In another aspect, the present invention is directed to a method for using a needle to thread a strap through a surface, the method comprising the steps of:
trapping an end of the strap while the needle is at the accessible side of the surface tissue; threading the needle, together with the trapped strap, through the surface, from the accessible side of the surface; releasing the trap, such that the driving of release is from the accessible side; and returning the needle to the accessible side while abandoning the strap at the threaded point, thereby performing threading from the accessible side.
[0041] The trapping of the end of the strap may comprise the steps of:
inserting the end of the strap into a niche; and grasping the end of the strap.
[0044] Grasping of the end of the strap may comprise the step of inserting a rod of the needle into a looped end of the strap.
[0045] According to another embodiment grasping of the end of the strap may comprise the step of applying physical force on the end of the strap towards the limiting wall thereof in the niche.
[0046] Releasing the trap may comprise the step of removing the rod from the end of the strap.
[0047] In another aspect, the present invention is directed to a method for installing an anterior implant, the method comprising the steps of:
threading at least two first straps of the implant into the arcus tendineous fascia pelvic (ATFP) ligaments; threading at least two second straps of the implant into the sacrospinous (SS) ligaments; and anchoring a loop between the second straps to the cervix.
[0051] In another aspect, the present invention is directed to a method for installing a posterior implant, the method comprising the steps of:
threading at least two straps of the implant into the sacrospinous (SS) ligaments; anchoring a first loop between the straps, to the cervix; and anchoring a second loop at the side opposing the straps, to the perineal body.
[0055] In addition to the exemplary aspects and embodiments described above, further aspects and embodiments will become apparent by reference to the figures and by study of the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0056] The objects and features of the present invention will become apparent from the following detailed description considered in conjunction with the accompanying drawings, in which:
[0057] FIG. 1 illustrates an anterior implant according to one embodiment of the present invention.
[0058] FIG. 2 illustrates an anterior view of the pelvic area before installing the anterior implant.
[0059] FIG. 3 illustrates the view of FIG. 2 after installing the anterior implant.
[0060] FIG. 4 illustrates a posterior implant according to one embodiment of the present invention.
[0061] FIG. 5 illustrates the view of FIG. 2 after installing the posterior implant.
[0062] FIG. 6 illustrates the head of a needle for threading the straps of the implants, according to one embodiment of the present invention.
[0063] FIG. 7 illustrates the first step of threading the straps of the implants, using the needle of FIG. 6 .
[0064] FIG. 8 illustrates the second step of threading the straps of the implants, using the needle of FIG. 6 .
[0065] FIG. 9 illustrates the third step of threading the straps of the implants, using the needle of FIG. 6 .
[0066] FIG. 10 illustrates the fourth step of threading the straps of the implants, using the needle of FIG. 6 .
[0067] FIG. 11 illustrates the needle of FIG. 6 and its operation.
[0068] FIG. 12 illustrates the operation of the needle of FIG. 6 from the aspect of the surgeon's access to the pelvic area.
[0069] FIG. 13 illustrates the operation of the needle of FIG. 6 in the aspect of FIG. 12 , to another ligament.
[0070] It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the invention, for which reference should be made to the appended claims. It should be further understood that the drawings are not necessarily drawn to scale and that, unless otherwise indicated, are merely intended to conceptually illustrate the structures and procedures described herein. Reference numerals may be repeated among the figures in order to indicate corresponding or analogous elements.
DETAILED DESCRIPTION OF THE INVENTION
[0071] In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these specific details. In some instances, well-known methods, procedures, components and circuits have not been described in detail, for the sake of brevity.
[0072] FIG. 1 illustrates an anterior implant according to one embodiment of the present invention.
[0073] Anterior implant 1 includes four straps 10 , each ending with a looped end 20 . Anterior implant 1 may also include a loop 8 between two interior straps 10 .
[0074] Anterior implant 1 may include spaces 4 for reducing the weight thereof.
[0075] FIG. 2 illustrates an anterior view of the pelvic area before installing the anterior implant.
[0076] The anterior view of pelvic area 34 refers to the side allowing surgical access through the patient's vaginal opening.
[0077] Denoted bones are the ischial spine 27 extending from the posterior border of the ischium 26 , and the sacrum 46 .
[0078] Also shown are the perineal body 52 , and the cervix 50 extending from the uterus (womb) 48 .
[0079] Pelvic area 34 includes two ligaments of arcus tendineous fascia pelvic (ATFP) 30 and two ligaments of sacrospinous (SS) 28 .
[0080] FIG. 3 illustrates the view of FIG. 2 after installing the anterior implant.
[0081] Anterior implant 1 is used for reconstructing the anterior pelvic floor, including prolapse of the urinary bladder and/or the colon and the small intestine.
[0082] Two straps 10 of anterior implant 1 are threaded into two ATFP ligaments 30 , and the other two straps 10 are inserted into two SS ligaments 28 .
[0083] Loop 8 may be sutured to cervix 50 for improving strength and security of the anchoring of anterior implant 1 .
[0084] FIG. 4 illustrates a posterior implant according to one embodiment of the present invention.
[0085] Posterior implant 2 includes two straps 10 , each ending with a looped end 20 . Posterior implant 2 may include a loop 36 between two interior straps 10 , and another loop 9 at the opposing side.
[0086] Posterior implant 2 may include spaces 4 for reducing the weight thereof.
[0087] FIG. 5 illustrates the view of FIG. 2 after installing the posterior implant.
[0088] Posterior implant 2 is used for reconstructing the posterior pelvic floor, including prolapse of the colon, the small intestine and/or the uterus (womb).
[0089] Two straps 10 of posterior implant 2 are inserted into two SS ligaments 28 .
[0090] Loop 36 may be sutured to cervix 50 , and loop 9 may be sutured to perineal body 52 for improving the strength and security of the connection.
[0091] FIG. 6 illustrates the head of a needle for threading the straps of the implants, according to one embodiment of the present invention.
[0092] A needle 6 is used for threading each of straps 10 through ATFP ligaments 30 and SS ligaments 28 .
[0093] The head of needle 6 includes a rod 18 , which may be manually slid back and forth in a track 16 within a body 14 , as in brake cables.
[0094] The edge 42 of rod 18 may be inserted into a niche 40 . The tip 12 of needle 6 is located at the edge of body 14 .
[0095] FIG. 7 illustrates the first step of threading the straps of the implants, using the needle of FIG. 6 .
[0096] The surgeon inserts looped end 20 of strap 10 into niche 40 , and traps it by rod edge 42 of rod 18 into looped end 20 .
[0097] In case that the surgeon has not succeeded in inserting rod 18 into looped end 20 , the surgeon may trap looped end 20 by applying physical force of rod edge 42 towards the limiting wall thereof in niche 40 .
[0098] According to another embodiment the surgeon may trap strap 10 directly by applying physical force of rod edge 42 on the end of strap 10 towards the limiting wall thereof in niche 40 .
[0099] FIG. 8 illustrates the second step of threading the straps of the implants, using the needle of FIG. 6 .
[0100] The surgeon then pushes tip 12 together with body 14 into an ATFP ligament 30 or into an SS ligament 28 , threading looped end 20 and strap 10 through the ligament.
[0101] FIG. 9 illustrates the third step of threading the straps of the implants, using the needle of FIG. 6 .
[0102] The surgeon then slides rod edge 42 out of niche 40 , releasing looped end 20 from rod edge 42 .
[0103] FIG. 10 illustrates the fourth step of threading the straps of the implants, using the needle of FIG. 6 .
[0104] The surgeon then pulls body 14 together with tip 12 out of ATFP ligament 30 or SS ligament 28 . Since looped end 20 has been released at the third step, and since ligament 30 (or 28 ) shrinks tightly, as shown by the arrows, strap 10 remains threaded while tip 12 exits.
[0105] FIG. 11 illustrates the needle of FIG. 6 and its operation.
[0106] The surgeon holds handle 24 of needle 6 , and slides rod 18 by toggling a toggle arm 22 , which is connected to rod 18 .
[0107] Needle 6 as a whole may be flexible like a brake cable, thin and long enough to occupy minimal surgery space.
[0108] Since tip 12 is inserted into the pelvic area, and toggle arm 22 is far away tip 12 , toggle arm is located outside the body of the patient and may be located farther and outside the surgical area.
[0109] It may be appreciated according to these steps that the surgeon can thread strap 10 from the side having surgical access, without requiring any additional perforations of the body from the opposing direction.
[0110] FIG. 12 illustrates the operation of the needle of FIG. 6 in aspect of the surgeon's access to the pelvic area.
[0111] The surgeon inserts finger 32 thereof into the vagina 44 between the patient's legs 38 and reaches pelvic area 34 (the lines of the parts inside are dashed). The surgeon then separates an SS ligament 28 from the other organs, locates tip 12 of needle 6 on a selected threading point on SS ligament 28 , and traps trapping looped end 20 to niche 40 of needle 6 .
[0112] The surgeon then penetrates tip 12 through SS ligament 28 and pushes into the desired depth; then releases looped end 20 from needle 6 by toggling toggle arm 22 , using the other hand thereof.
[0113] The surgeon can then pull tip 12 back, leaving looped end 20 and strap 10 at the side beyond, having tight shrinking of SS ligament 28 towards strap 10 at the threaded point.
[0114] Tying of strap 10 is not required due to natural tying of SS ligament 28 to strap 10 .
[0115] FIG. 13 illustrates the operation of the needle of FIG. 6 in aspect FIG. 12 , to another ligament.
[0116] The surgeon inserts the finger 32 thereof into vagina 44 , then separates an ATFP ligament 30 , and locates tip 12 of needle 6 on the selected threading point, after trapping looped end 20 to niche 40 of needle 6 .
[0117] The surgeon then penetrates tip 12 through ATFP ligament 30 and on to the desired depth; then releases looped end 20 from needle 6 by toggling toggle arm 22 , using the other hand thereof, then pulls tip 12 back leaving looped end 20 and strap 10 at the side beyond, having tight shrinking of ATFP ligament 30 towards strap 10 at the threaded point.
[0118] In the figures and description herein, the following numerals and symbols have been mentioned:
[0119] numeral 1 denotes an anterior implant;
[0120] numeral 2 denotes a posterior implant;
[0121] numeral 4 denotes a space for reducing the weight of an implant;
[0122] numeral 6 denotes a needle according to one embodiment of the present invention;
[0123] numeral 8 denotes a loop in the anterior implant for anchoring it to the cervix;
[0124] numeral 9 denotes a loop in the posterior implant for anchoring it to the perineal body;
[0125] numeral 10 denotes a strap extending from the implant;
[0126] numeral 12 denotes a tip of the inventive needle;
[0127] numeral 14 denotes the body of the inventive needle;
[0128] numeral 16 denotes a track within the body of the needle;
[0129] numeral 18 denotes a rod traveling within the body of the needle;
[0130] numeral 20 denotes a looped end at the edge of the implant strap;
[0131] numeral 22 denotes a toggle arm for trapping and releasing the looped end;
[0132] numeral 24 denotes a handle of the needle;
[0133] numeral 26 denotes the ischium (bone);
[0134] numeral 27 denotes the ischial spine (bone);
[0135] numeral 28 denotes a sacrospinous (SS) ligament;
[0136] numeral 30 denotes an arcus tendineous fascia pelvic (ATFP) ligament;
[0137] numeral 32 denotes a surgeon's finger;
[0138] numeral 34 denotes the pelvic area;
[0139] numeral 36 denotes a loop in the posterior implant for anchoring it to the cervix;
[0140] numeral 38 denotes a patient's leg;
[0141] numeral 40 denotes a niche in the needle for trapping the looped end of the strap;
[0142] numeral 42 denotes the edge of the rod sliding in the track;
[0143] numeral 44 denotes the vagina, into which the surgeon inserts the finger thereof;
[0144] numeral 46 denotes the sacrum (bone);
[0145] numeral 48 denotes the uterus (womb);
[0146] numeral 50 denotes the cervix, extending from the uterus; and
[0147] numeral 52 denotes the perineal body;
[0148] While certain features of the invention have been illustrated and described herein, the invention can be embodied in other forms, ways, modifications, substitutions, canchores, equivalents, and so forth. The foregoing description of the embodiments of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of this disclosure. It is intended that the scope of the invention be limited not by this detailed description, but rather by the claims appended hereto. | In one aspect, the present invention may be directed to a needle for surgical threading of a strap of an implant through a tissue, the needle comprising: a trap for trapping the strap to the needle while the needle may be at the accessible side of the tissue; a tip for threading the trapped strap from the accessible side to the opposing side; and a mechanism for releasing the trap, the mechanism driven from the accessible side of the tissue, thereby allowing return of the tip to the accessible side of the tissue while abandoning the strap at the threaded point, thus performing the threading from the accessible side of the tissue. | big_patent |
FIELD OF THE INVENTION
[0001] The invention relates to methods and apparatus for the provision of ventilatory assistance matched to a subject's respiratory need. The ventilatory assistance can be for a subject who is either spontaneously or non-spontaneously breathing, or moves between these breathing states. The invention is especially suitable for, but not limited to, spontaneously breathing human subjects requiring longterm ventilatory assistance, particularly during sleep.
BACKGROUND OF THE INVENTION
[0002] Subjects with severe lung disease, chest wall disease, neuromuscular disease, or diseases of respiratory control may require in-hospital mechanical ventilatory assistance, followed by longterm home mechanical ventilatory assistance, particularly during sleep. The ventilator delivers air or air enriched with oxygen to the subject, via an interface such as a nosemask, at a pressure that is higher during inspiration and lower during expiration.
[0003] In the awake state, and while waiting to go to sleep, the subject's ventilatory pattern is variable in rate and depth. Most known ventilatory devices do not accurately match the amplitude and phase of mask pressure to the subject's spontaneous efforts, leading to discomfort or panic. Larger amounts of asynchrony also reduce the efficiency of the device. During sleep, there are changes in the neural control of breathing as well as the mechanics of the subject's airways, respiratory muscles and chest wall, leading to a need for substantially increased ventilatory support. Therefore, unless the device can automatically adjust the degree of support, the amplitude of delivered pressure will either be inadequate during sleep, or must be excessive in the awake state. This is particularly important in subjects with abnormalities of respiratory control, for example central hypoventilation syndromes, such as Obesity Hypoventilation Syndrome, where there is inadequate chemoreceptor drive, or Cheyne Stokes breathing such as in patients with severe cardiac failure or after a stroke, where there is excessive or unstable chemoreceptor drive.
[0004] Furthermore, during sleep there are inevitably large leaks between mask and subject, or at the subject's mouth if this is left free. Such leaks worsen the error in matching the phase and magnitude of the machine's effort to the subject's needs, and, in the case of mouth leak, reduce the effectiveness of the ventilatory support.
[0005] Ideally a ventilatory assistance device should simultaneously address the following goals:
[0000] (i) While the subject is awake and making substantial ventilatory efforts, the delivered assistance should be closely matched in phase with the patient's efforts.
[0000] (ii) The machine should automatically adjust the degree of assistance to maintain at least a specified minimum ventilation, without relying on the integrity of the subject's chemoreflexes.
[0000] (iii) It should continue to work correctly in the presence of large leaks.
[0006] Most simple home ventilators either deliver a fixed volume, or cycle between two fixed pressures. They do so either at a fixed rate, or are triggered by the patient's spontaneous efforts, or both. All such simple devices fail to meet goal (ii) of adjusting the degree of assistance to maintain at least a given ventilation. They also largely fail to meet goal (i) of closely matching the subjects respiratory phase: timed devices make no attempt to synchronize with the subject's efforts; triggered devices attempt to synchronize the start and end of the breath with the subject's efforts, but make no attempt to tailor the instantaneous pressure during a breath to the subject's efforts. Furthermore, the triggering tends to fail in the presence of leaks, thus failing goal (iii).
[0007] The broad family of servo-ventilators known for at least 20 years measure ventilation and adjust the degree of assistance to maintain ventilation at or above a specified level, thus meeting goal (ii), but they still fail to meet goal (i) of closely matching the phase of the subject's spontaneous efforts, for the reasons given above. No attempt is made to meet goal (iii).
[0008] Proportional assistist ventilation (PAV), as taught by Dr Magdy Younes, for example in Principles and Practice of Mechanical Ventilation , chapter 15, aims to tailor the pressure vs time profile within a breath to partially or completely unload the subject's resistive and elastic work, while minimizing the airway pressure required to achieve the desired ventilation. During the inspiratory half-cycle, the administered pressure takes the form:
P ( t )= P 0 +R.f RESP ( t )+ E.V ( t )
where R is a percentage of the resistance of the airway, f RESP (t) is the instantaneous respiratory airflow at time t, E is a percentage of the elastance of lung and chest wall, and V(t) is the volume inspired since the start of inspiration to the present moment. During the expiratory half-cycle, V(t) is taken as zero, to produce passive expiration.
[0009] An advantage of proportional assist ventilation during spontaneous breathing is that the degree of assistance is automatically adjusted to suit the subject's immediate needs and their pattern of breathing, and is therefore comfortable in the spontaneously breathing subject. However, there are at least two important disadvantages. Firstly, V(t) is calculated as the integral of flow with respect to time since the start of inspiration. A disadvantage of calculating V(t) in this way is that, in the presence of leaks, the integral of the flow through the leak will be included in V(t), resulting in an overestimation of V(t), in turn resulting in a runaway increase in the administered pressure. This can be distressing to the subject. Secondly, PAV relies on the subject's chemoreceptor reflexes to monitor the composition of the arterial blood, and thereby set the level of spontaneous effort. The PAV device then amplifies this spontaneous effort. In subjects with abnormal chemoreceptor reflexes, the spontaneous efforts may either cease entirely, or become unrelated to the composition of the arterial blood, and amplification of these efforts will yield inadequate ventilation. In patients with existing Cheyne Stokes breathing during sleep, PAV will by design amplify the subject's waxing and waning breathing efforts, and actually make matters worse by exaggerating the disturbance. Thus PAV substantially meets goal (i) of providing assistance in phase with the subject's spontaneous ventilation, but cannot meet goal (ii) of adjusting the depth of assistance if the subject has inadequate chemoreflexes, and does not satisfactorily meet goal (iii).
[0010] Thus there are known devices that meet each of the above goals, but there is no device that meets all the goals simultaneously. Additionally, it is desirable to provide improvements over the prior art directed to any one of the stated goals.
[0011] Therefore, the present invention seeks to achieve, at least partially, one or more of the following:
[0000] (i) to match the phase and degree of assistance to the subject's spontaneous efforts when ventilation is well above a target ventilation,
[0012] (ii) to automatically adjust the degree of assistance to maintain at least a specified minimum average ventilation without relying on the integrity of the subject's chemoreflexes and to damp out instabilities in the spontaneous ventilatory efforts, such as Cheyne Stokes breathing.
[0000] (iii) to provide some immunity to the effects of sudden leaks.
DISCLOSURE OF THE INVENTION
[0013] In what follows, a fuzzy membership function is taken as returning a value between zero and unity, fuzzy intersection A AND B is the smaller of A and B , fuzzy union A OR B is the larger of A and B , and fuzzy negation NOT A is 1− A.
[0014] The invention discloses the determination of the instantaneous phase in the respiratory cycle as a continuous variable.
[0015] The invention further discloses a method for calculating the instantaneous phase in the respiratory cycle including at least the steps of determining that if the instantaneous airflow is small and increasing fast, then it is close to start of inspiration, if the instantaneous airflow is large and steady, then it is close to mid-inspiration, if the instantaneous airflow is small and decreasing fast, then it is close to mid-expiration, if the instantaneous airflow is zero and steady, then it is during an end-expiratory pause, and airflow conditions intermediate between the above are associated with correspondingly intermediate phases.
[0016] The invention further discloses a method for determining the instantaneous phase in the respiratory cycle as a continuous variable from 0 to 1 revolution, the method comprising the steps of:
selecting at least two identifiable features F N of a prototype flow-vs-time waveform f(t) similar to an expected respiratory flow-vs-time waveform, and for each said feature: determining by inspection the phase φ N in the respiratory cycle for said feature, assigning a weight W N to said phase, defining a “magnitude” fuzzy set M N whose membership function is a function of respiratory airflow, and a “rate of change” fuzzy set C N , whose membership function is a function of the time derivative of respiratory airflow, chosen such that the fuzzy intersection M N AND C N will be larger for points on the generalized prototype respiratory waveform whose phase is closer to the said feature F N than for points closer to all other selected features, setting the fuzzy inference rule R N for the selected feature F N to be: If flow is M N and rate of change of flow is C N then phase=φ N , with weight W N . measuring leak-corrected respiratory airflow, for each feature F N calculating fuzzy membership in fuzzy sets M N and C N , for each feature F N applying fuzzy inference rule R N to determine the fuzzy extent Y N =M N AND C N to which the phase is φ N , and applying a defuzzification procedure using Y N at phases φ N and weights W N to determine the instantaneous phase φ.
[0025] Preferably, the identifiable features include zero crossings, peaks, inflection points or plateaus of the prototype flow-vs-time waveform. Furthermore, said weights can be unity, or chosen to reflect the anticipated reliability of deduction of the particular feature.
[0026] The invention further discloses a method for calculating instantaneous phase in the respiratory cycle as a continuous variable, as described above, in which the step of calculating respiratory airflow includes a low pass filtering step to reduce non-respiratory noise, in which the time constant of the low pass filter is an increasing function of an estimate of the length of the respiratory cycle.
[0027] The invention further discloses a method for measuring the instantaneous phase in the respiratory cycle as a continuous variable as described above, in which the defuzzification step includes a correction for any phase delay introduced in the step of low pass filtering respiratory airflow.
[0028] The invention further discloses a method for measuring the average respiratory rate, comprising the steps of:
[0029] measuring leak-corrected respiratory airflow,
[0030] from the respiratory airflow, calculating the instantaneous phase φ in the respiratory cycle as a continuous variable from 0 to 1 revolution, calculating the instantaneous rate of change of phase dφ/dt, and
[0031] calculating the average respiratory rate by low pass filtering said instantaneous rate of change of phase dφ/dt.
[0032] Preferably, the instantaneous phase is calculated by the methods described above.
[0033] The invention further discloses a method for providing ventilatory assistance in a spontaneously breathing subject, comprising the steps, performed at repeated sampling intervals, of:
[0034] ascribing a desired waveform template function Π(φ), with domain 0 to 1 revolution and range 0 to 1,
[0035] calculating the instantaneous phase φ in the respiratory cycle as a continuous variable from 0 to 1 revolution,
[0036] selecting a desired pressure modulation amplitude A,
[0037] calculating a desired instantaneous delivery pressure as an end expiratory pressure plus the desired pressure modulation amplitude A multiplied by the value of the waveform template function Π(φ) at the said calculated phase φ, and
[0038] setting delivered pressure to subject to the desired delivery pressure.
[0039] The invention further discloses a method for providing ventilatory assistance in a spontaneously breathing subject as described above, in which the step of selecting a desired pressure modulation amplitude is a fixed amplitude.
[0040] The invention further discloses a method for providing ventilatory assistance in a spontaneously breathing subject as described above, in which the step of selecting a desired pressure modulation amplitude in which said amplitude is equal to an elastance multiplied by an estimate of the subject's tidal volume.
[0041] The invention further discloses a method for providing ventilatory assistance in a spontaneously breathing subject as described above, in which the step of selecting a desired pressure modulation amplitude comprises the substeps of:
specifying a typical respiratory rate giving a typical cycle time, specifying a preset pressure modulation amplitude to apply at said typical respiratory rate, calculating the observed respiratory rate giving an observed cycle time, and calculating the desired amplitude of pressure modulation as said preset pressure modulation amplitude multiplied by said observed cycle time divided by the said specified cycle time.
[0046] The invention further discloses a method for providing ventilatory assistance in a spontaneously breathing subject, including at least the step of determining the extent that the subject is adequately ventilated, to said extent the phase in the respiratory cycle is determined from the subject's respiratory airflow, but to the extent that the subject's ventilation is inadequate, the phase in the respiratory cycle is assumed to increase at a pre-set rate, and setting mask pressure as a function of said phase.
[0047] The invention further discloses a method for providing ventilatory assistance in a spontaneously breathing subject, comprising the steps of: measuring respiratory airflow, determining the extent to which the instantaneous phase in the respiratory cycle can be determined from said airflow, to said extent determining said phase from said airflow but to the extent that the phase in the respiratory cycle cannot be accurately determined, the phase is assumed to increase at a preset rate, and delivering pressure as a function of said phase.
[0048] The invention further discloses a method for calculating the instantaneous inspired volume of a subject, operable substantially without run-away under conditions of suddenly changing leak, the method comprising the steps of:
[0049] determining respiratory airflow approximately corrected for leak,
[0050] calculating an index J varying from 0 to 1 equal to the fuzzy extent to which said corrected respiratory airflow is large positive for longer than expected, or large negative for longer than expected,
[0051] identifying the start of inspiration, and
[0052] calculating the instantaneous inspired volume as the integral of said corrected respiratory airflow multiplied by the fuzzy negation of said index J with respect to time, from start of inspiration.
[0053] The invention further discloses a method “A” for providing ventilatory assistance in a spontaneously breathing subject, the method comprising the steps, performed at repeated sampling intervals, of:
[0054] determining respiratory airflow approximately corrected for leak,
[0055] calculating an index J varying from 0 to 1 equal to the fuzzy extent to which said respiratory airflow is large positive for longer than expected, or large negative for longer than expected,
[0056] calculating a modified airflow equal to said respiratory airflow multiplied by the fuzzy negation of said index J,
[0057] identifying the phase in the respiratory cycle,
[0058] calculating the instantaneous inspired volume as the integral of said modified airflow with respect to time, with the integral held at zero during the expiratory portion of the respiratory cycle,
[0059] calculating a desired instantaneous delivery pressure as a function at least of the said instantaneous inspired volume, and
[0060] setting delivered pressure to subject to the desired delivery pressure.
[0061] The invention further discloses a method “B” for providing ventilatory assistance in a spontaneously breathing subject, comprising the steps of:
[0062] determining respiratory airflow approximately corrected for leak,
[0063] calculating an index J varying from 0 to 1 equal to the fuzzy extent to which the respiratory airflow is large positive for longer than expected, or large negative for longer than expected,
[0064] identifying the phase in the respiratory cycle,
[0065] calculating a modified respiratory airflow equal to the respiratory airflow multiplied by the fuzzy negation of said index J,
[0066] calculating the instantaneous inspired volume as the integral of the modified airflow with respect to time, with the integral held at zero during the expiratory portion of the respiratory cycle,
[0067] calculating the desired instantaneous delivery pressure as an expiratory pressure plus a resistance multiplied by the instantaneous respiratory airflow plus a nonlinear resistance multiplied by the respiratory airflow multiplied by the absolute value of the respiratory airflow plus an elastance multiplied by the said adjusted instantaneous inspired volume, and
[0068] setting delivered pressure to subject to the desired delivery pressure.
[0069] The invention yet further discloses a method “C” for providing assisted ventilation to match the subject's need, comprising the steps of:
[0070] describing a desired waveform template function Π(φ), with domain 0 to 1 revolution and range 0 to 1,
[0071] determining respiratory airflow approximately corrected for leak,
[0072] calculating an index J varying from 0 to 1 equal to the fuzzy extent to which the respiratory airflow is large positive for longer than expected, or large negative for longer than expected,
[0073] calculating J PEAK equal to the recent peak of the index J,
[0074] calculating the instantaneous phase in the respiratory cycle,
[0075] calculating a desired amplitude of pressure modulation, chosen to servo-control the degree of ventilation to at least exceed a specified ventilation,
[0076] calculating a desired delivery pressure as an end expiratory pressure plus the calculated pressure modulation amplitude A multiplied by the value of the waveform template function Π(φ) at the said calculated phase φ, and
[0077] setting delivered pressure to subject to said desired instantaneous delivered pressure.
[0078] The invention yet further discloses a method for providing assisted ventilation to match the subject's need, as described above, in which the step of calculating a desired amplitude of pressure modulation, chosen to servo-control the degree of ventilation to at least exceed a specified ventilation, comprises the steps of:
[0079] calculating a target airflow equal to twice the target ventilation divided by the target respiratory rate,
[0080] deriving an error term equal to the absolute value of the instantaneous low pass filtered respiratory airflow minus the target airflow, and
[0081] calculating the amplitude of pressure modulation as the integral of the error term multiplied by a gain, with the integral clipped to lie between zero and a maximum.
[0082] The invention yet further discloses a method for providing assisted ventilation to match the subject's need, as described above, in which the step of calculating a desired amplitude of pressure modulation, chosen to servo-control the degree of ventilation to at least exceed a specified ventilation, comprises the following steps:
calculating a target airflow equal to twice the target ventilation divided by the target respiratory rate, deriving an error term equal to the absolute value of the instantaneous low pass filtered respiratory airflow minus the target airflow, calculating an uncorrected amplitude of pressure modulation as the integral of the error term multiplied by a gain, with the integral clipped to lie between zero and a maximum, calculating the recent average of said amplitude as the low pass filtered amplitude, with a time constant of several times the length of a respiratory cycle, and setting the actual amplitude of pressure modulation to equal the said low pass filtered amplitude multiplied by the recent peak jamming index J PEAK plus the uncorrected amplitude multiplied by the fuzzy negation of J PEAK .
[0088] The invention yet further discloses a method for providing assisted ventilation to match the subject's need, and with particular application to subjects with varying respiratory mechanics, insufficient respiratory drive, abnormal chemoreceptor reflexes, hypoventilation syndromes, or Cheyne Stokes breathing, combined with the advantages of proportional assist ventilation adjusted for sudden changes in leak, comprising the steps, performed at repeated sampling intervals, of:
calculating the instantaneous mask pressure as described for methods “A” or “B” above, calculating the instantaneous mask pressure as described for method “C” above, calculating a weighted average of the above two pressures, and setting the mask pressure to the said weighted average.
[0093] The invention yet further discloses apparatus to give effect to each one of the methods defined, including one or more transducers to measure flow and/or pressure, processor means to perform calculations and procedures, flow generators for the supply of breathable gas at a pressure above atmospheric pressure and gas delivery means to deliver the breathable gas to a subject's airways.
[0094] The apparatus can include ventilators, ventilatory assist devices, and CPAP devices including constant level, bi-level or autosetting level devices.
[0095] It is to be understood that while the algorithms embodying the invention are explained in terms of fuzzy logic, approximations to these algorithms can be constructed without the use of the fuzzy logic formalism.
BRIEF DESCRIPTION OF THE DRAWINGS
[0096] A number of embodiments will now be described with reference to the accompanying drawings in which:
[0097] FIGS. 1 a and 1 b show apparatus for first and second embodiments of the invention respectively;
[0098] FIG. 2 is a pressure waveform function Π(Φ) used in the calculation of the desired instantaneous delivery pressure as a function of the instantaneous phase Φ in the respiratory cycle for a first embodiment of the invention;
[0099] FIG. 3 shows fuzzy membership functions for calculating the degree of membership in each of five magnitude fuzzy sets (“large negative”, “small negative”, “zero”, “small positive”, and “large positive”) from the normalized respiratory airflow according to the first embodiment of the invention; and
[0100] FIG. 4 shows fuzzy membership functions for calculating the degree of membership in each of five rate of change fuzzy sets (“rising fast”, “rising slowly”, “steady”, “falling slowly”, and “falling fast”) from the normalized rate of change of airflow according to the first embodiment of the invention;
[0101] FIG. 5 is a pressure waveform function Π(Φ) used in the calculation of the desired instantaneous delivery pressure as a function of the instantaneous phase Φ in the respiratory cycle for a second embodiment of the invention;
[0102] FIG. 6 shows calculation of a quantity “lead-in” as a function of time since the most recent mask off-on transition;
[0103] FIG. 7 shows a fuzzy membership function for fuzzy set A I as a function of time since the most recent expiratory-to-inspiratory (negative-to-positive) zero crossing of the respiratory airflow signal, such that the membership function measures the extent to which the respiratory airflow has been positive for longer than expected;
[0104] FIG. 8 shows a membership function for fuzzy set B I as a function of respiratory airflow, such that the membership function measures the extent to which respiratory airflow is large positive;
[0105] FIG. 9 shows an electrical analog of the calculation of a recent peak jamming index J PEAK from the instantaneous jamming index J;
[0106] FIG. 10 shows the calculation of the time constant τ used in low pass filtering steps in the calculation of the conductance of a leak, as a function of the recent peak jamming index J PEAK .
[0107] FIG. 11 shows a prototypical respiratory flow-time curve, with time on the x-axis, marking nine features;
[0108] FIG. 12 shows membership functions for fuzzy sets “large negative”, “small negative”, “zero”, “small positive”, and “large positive” as functions of normalized respiratory airflow according to a second embodiment of the invention;
[0109] FIG. 13 shows membership functions for fuzzy sets “falling”, “steady”, and “rising” as functions of normalized rate of change of respiratory airflow df/dt according to a second embodiment of the invention;
[0110] FIG. 14 shows the membership function for fuzzy set “hypopnea”;
[0111] FIG. 15 shows the calculation of the time constant τ for calculation of normalized recent ventilation, as a function of “servo gain” being the gain used for servo-control of minute ventilation to at least exceed a specified target ventilation;
[0112] FIG. 16 shows the membership function for fuzzy set “hyperpnea” as a function of normalized recent ventilation;
[0113] FIG. 17 shows the membership function for fuzzy set “big leak” as a function of leak;
[0114] FIG. 18 shows the membership functions for fuzzy sets “switch negative” and “switch positive” as a function of nomalized respiratory airflow;
[0115] FIG. 19 shows the membership functions for fuzzy sets “insp_phase” and “exp_phase” as functions of the instantaneous phase in the respiratory cycle φ;
[0116] FIG. 20 shows schematically how function W(y), used in defuzzification, calculates the area (shaded) of an isosceles triangle of unit base and height cut off below height y;
[0117] FIGS. 21-26 show actual 60 second flow and pressure tracings from the second embodiment of the invention during operation; the vertical scale for flow (heavy trace) is ±1 L/sec, inspiration upwards and the vertical scale for the pressure (light trace) is 0-25 cmH 2 O; where:
[0118] FIG. 21 shows that a short central apnea (b) is permitted when effort ceases at point (c) after a preceding deep breath (a);
[0119] FIG. 22 shows that a central apnea is not permitted when effort ceases at arrow (a) without a preceeding deep breath;
[0120] FIG. 23 is recorded with servo gain set high, and shows that a central apnea is no longer permitted when effort ceases at arrow (a) despite preceding deep breathing;
[0121] FIG. 24 shows automatically increasing end-inspiratory pressure as the subject makes voluntarily deeper inspiratory efforts;
[0122] FIG. 25 is recorded with a somewhat more square waveform selected, and shows automatically increasing pressure support when the subject voluntarily attempts to resist by stiffening the chest wall at point (a);
[0123] FIG. 26 shows that with sudden onset of a sever 1.4 L/sec leak at (a), the flow signal returns to baseline (b) within the span of a single breath, and pressure continues to cycle correctly throughout; and
[0124] FIG. 27 shows an actual 60 second tracing showing respiratory airflow (heavy trace, ±1 L/sec full scale) and instantaneous phase (light trace, 0-1 revolution full scale).
DESCRIPTION OF PREFERRED EMBODIMENTS
[0125] The two embodiments to be described are ventilators that operate in a manner that seeks to simultaneously achieve the three goals stated above.
First Embodiment
[0126] Apparatus to give effect to a first embodiment of the apparatus is shown in FIG. 1 a . A blower 10 supplies a breathable gas to mask 11 in communication with the subject's airway via a delivery tube 12 and exhausted via a exhaust diffuser 13 . Airflow to the mask 11 is measured using a pneumotachograph 14 and a differential pressure transducer 15 . The mask flow signal from the transducer 15 is then sampled by a microprocessor 16 . Mask pressure is measured at the port 17 using a pressure transducer 18 . The pressure signal from the transducer 18 is then sampled by the microprocessor 16 . The microprocessor 16 sends an instantaneous mask pressure request signal to the servo 19 , which compares said pressure request signal with actual pressure signal from the transducer 18 to the control fan motor 20 . The microprocessor settings can be adjusted via a serial port 21 .
[0127] It is to be understood that the mask could equally be replaced with a tracheotomy tube, endotracheal tube, nasal pillows, or other means of making a sealed connection between the air delivery means and the subject's airway.
[0128] The microprocessor 16 is programmed to perform the following steps, to be considered in conjunction with Tables 1 and 2.
TABLE 1 Fuzzy Inference Rules for a first embodiment N Fuzzy Interference Rule Fuzzy Phase 1 if size is Zero and rate of Increasing then phase is Start Inspiration 2 if size is Small and rate of Increasing then phase is Early Inspiration Positive change is Slowly 3 if size is Large and race of Steady then phase is Peak Inspiration Positive change is 4 if size is Small and rate of Decreasing then phase is Late Inspiration Positive change is Slowly 5 if size is Zero and rate of Decreasing then phase is Start Expiration change is Fast 6 if size is Small and rate of Decreasing then phase is Early Expiration Negative change is Slowly 7 if size is Large and rate of Steady then phase is Peak Expiration Negative change is 8 if size is Small and rate of Increasing then phase is Late Expiration Negative change is Slowly 9 if size is Zero and rate of Steady then phase is Expiratory Pause change is 10 always phase is Unchanged
[0129]
TABLE 2
Association of phases with fuzzy rules for a first embodiment.
N
Phase
Φ N
1
Start Inspiration
0.0
2
Early Inspiration
values intermediate between
3
Peak Inspiration
0.0 and 0.5
4
Late Inspiration
5
Start Expiration
0.50
6
Early Expiration
values intermediate between
7
Peak Expiration
0.5 and 1.0
8
Late Expiration
9
Expiratory Pause
10
Unchanged
Φ
1. Set desired target values for the duration of inspiration TI TGT , duration of expiration TE TGT , and minute ventilation V TGT . Choose suitable constants P 0 and A STD where P 0 is the desired end expiratory pressure, and A STD is the desired increase in pressure above P 0 at end inspiration for a breath of duration TT TGT =TI TGT +TE TGT .
2. Choose a suitable pressure waveform function Π(Φ), such as that shown in FIG. 2 , such that the desired delivery pressure at phase Φ will be given by:
P=P 0 +A Π(Φ)
where the amplitude A equals the difference between the end inspiratory pressure and end expiratory pressure. However, other waveforms may be suitable for subjects with particular needs.
3. Initialize the phase Φ in the respiratory cycle to zero, and initialize the current estimates of actual inspiratory and expiratory duration TI and TE to TI TGT and TE TGT respectively.
4. Initialize the rate of change of phase during inspiration ΔΦ I between sampling intervals of length T to:
ΔΦ+=0.5 T/TI TGT
5. Initialize the rate of change of phase during expiration ΔΦ E to:
Δ E =0.5 T/TE TGT
6. Measure the instantaneous respiratory airflow f RESP .
7. Calculate the average total breath duration TT=TI+TE
8. Low pass filter the respiratory airflow with an adjustable time constant τf, where τf is a fixed small fraction of TT.
9. Calculate the instantaneous ventilation V, as half the absolute value of the respiratory airflow:
V= 0.5 |f RESP |
10. From the target ventilation V TGT and the measured minute ventilation V, derive an error term V ERR , such that large values of V ERR indicate inadequate ventilation:
V ERR =∫( V TGT −V ) dt
11. Take V BAR as the result of low pass filtering V with a time constant τV BAR which is long compared with TT.
12. Calculate a normalized airflow f NORM , where
f NORM =f RESP /V BAR .
13. From f NORM , calculate the degree of membership in each of the fuzzy sets whose membership functions are shown in FIG. 3 .
14. Calculate a normalized rate of change df NORM /dΦ, equal to df NORM /dt divided by the current estimate of the average respiratory cycle time TT.
15. From the normalized rate of change, calculate the degree of membership in each of the fuzzy sets shown in FIG. 4 .
16. For each row N in Table 1, calculate the degree of membership g N in the fuzzy set shown in the column labelled Fuzzy Phase, by applying the fuzzy inference rules shown.
17. Associate with the result of each of the N rules a phase Φ N as shown in Table 2, noting that Φ 10 is the current phase Φ.
18. Increase each of the Φ N excepting Φ 10 by 0.89 τ/TT, to compensate for the previous low pass filtering step.
19. Calculate a new instantaneous phase Φ INST as the angle to the center of gravity of N unit masses at polar coordinates of radius g N and angle Φ N revolutions.
[0150] 20. Calculate the smallest signed difference ΔΦ INST bewteen the phase estimated in the previous step and the current phase.
ΔΦ INST = 1 − (ΔΦ INST − Φ) (Φ INST − Φ > 0.5) ΔΦ INST = Φ INST − Φ + 1 (Φ INST − Φ < − 0.5) ΔΦINST = Φ INST − Φ (otherwise)
[0151] 21. Derive a revised estimate ΔΦ REV equal to a weighted mean of the value calculated in the previous step and the average value (ΔΦ I or ΔΦ E as appropriate).
ΔΦ = (1 − W) ΔΦ I + WΔΦ INST (0 < Φ < 0.5) ΔΦ = (1 − W) ΔΦ I + WΔΦ INST (otherwise)
Smaller values of W will cause better tracking of phase if the subject is breathing regularly, and larger values will cause better tracking of phase if the subject is breathing irregularly. 22. Derive a blending fraction B, such that the blending fraction is unity if the subject's ventilation is well above V TGT , zero if the subject is breathing near or below V TGT , and increasing proportionally from zero to unity as the subject's ventilation increases through an intermediate range.
[0154] 23. Calculate ΔΦ BLEND influenced chiefly by ΔΦ calculated in step 21 from the subject's respiratory activity if the subject's ventilation is well above V TGT ; influenced chiefly by the target respiratory duration if the subject is breathing near or below V TGT ; and proportionally between these two amounts if ventilation is in an intermediate range:
ΔΦ BLEND = B ΔΦ + 0.5 (1 − B) T/TI TGT (0 < Φ < 0.5) ΔΦ BLEND = B ΔΦ + 0.5 (1 − B) T/TE TGT (otherwise)
24. Increment Φ by ΔΦ BLEND
[0156] 25. Update the average rate of change of phase (ΔΦ I or ΔΦ E as appropriate).
ΔΦ I = T/τ VBAR (ΔΦ BLEND − ΔΦ I ) (0 < Φ < 0.5) ΔΦ E = T/τ VBAR (ΔΦ BLEND − ΔΦ E ) (otherwise)
26. Recalculate the approximate duration of inspiration TI and expiration TE:
TI= 0.5 T/ΔΦ I
TE= 0.5 T/ΔΦ E
[0158] 27. Calculate the desired mask pressure modulation amplitude A D :
A D = A STD /2 (TT < TT STD /2) A D = 2 · A STD (TT > 2 · TT STD ) A D = A STD · TT/TT STD (otherwise)
[0159] 28. From the error term V ERR , calculate an additional mask pressure modulation amplitude A E :
A E = K · V ERR (for V ERR > 0) A E = 0 (otherwise)
where larger values of K will produce a faster but less stable control of the degree of assistance, and smaller values of K will produce slower but more stable control of the degree of assistance. 29. Set the mask pressure P MASK to:
P MASK =P 0 +( A D +A E )Π(Φ)
30. Wait for a sampling interval T, short compared with the duration of a respiratory cycle, and then continue at the step of measuring respiratory airflow.
Measurement of Respiratory Airflow
[0163] As follows from above, it is necessary to respiratory airflow, which is a standard procedure to one skilled in the art. In the absence of leak, respiratory airflow can be measured directly with a pneumotachograph placed between the mask and the exhaust. In the presence of a possible leak, one method disclosed in European Publication No 0 651 971 incorporated herein by cross-reference is to calculate the mean flow through the leak, and thence calculate the amount of modulation of the pneumotachograph flow signal due to modulation of the flow through the leak induced by changing mask pressure, using the following steps:
1. Measure the airflow at the mask f MASK using a pneumotachograph 2. Measure the pressure at the mask P MASK 3. Calculate the mean leak as the low pass filtered airflow, with a time constant long compared with a breath. 4. Calculate the mean mask pressure as the low pass filtered mask pressure, with a time constant long compared with a breath. 5. Calculate the modulation of the flow through the leak as:
δ(leak)=0.5 times the mean leak times the inducing pressure,
where the inducing pressure is P MASK −mean mask pressure.
Thence the instantaneous respiratory airflow can be calculated as:
f RESP =f MASK −mean leak−δ(leak)
A convenient extension as further disclosed in EP 0 651 971 (incorporated herein by cross-reference) is to measure airflow f TURBINE and pressure P TURBINE at the outlet of the turbine, and thence calculate P MASK and f MASK by allowing for the pressure drop down the air delivery hose, and the airflow lost via the exhaust:
1. ΔP HOS E=K 1 (F TURBINE )−K 2 (F TURBINE ) 2 2. PMASK =P TURBINE −ΔP HOSE 3. F EXHAUST =K3√P MASK 4. F MASK =F TURBINE −F EXHAUST
Alternative Embodiment
[0173] The following embodiment is particularly applicable to subjects with varying respiratory mechanics, insufficient respiratory drive, abnormal chemoreceptor reflexes, hypoventilation syndromes, or Cheyne Stokes breathing, or to subjects with abnormalities of the upper or lower airways, lungs, chest wall, or neuromuscular system.
[0174] Many patients with severe lung disease cannot easily be treated using a smooth physiological pressure waveform, because the peak pressure required is unacceptably high, or unachievable with for example a nose-mask. Such patients may prefer a square pressure waveform, in which pressure rises explosively fast at the moment of commencement of inspiratory effort. This may be particularly important in patients with high intrinsic PEEP, in which it is not practicable to overcome the intrinsic PEEP by the use of high levels of extrinsic PEEP or CPAP, due to the risk of hyperinflation. In such subjects, any delay in triggering is perceived as very distressing, because of the enormous mis-match between expected and observed support. Smooth waveforms exaggerate the perceived delay, because of the time taken for the administered pressure to exceed the intrinsic PEEP. This embodiment permits the use of waveforms varying continuously from square (suitable for patients with for example severe lung or chest wall disease or high intrinsic PEEP) to very smooth, suitable for patients with normal lungs and chest wall, but abnormal respiratory control, or neuromuscular abnormalities. This waveform is combined either with or without elements of proportional assist ventilation (corrected for sudden changes in leak), with servo-control of the minute ventilation to equal or exceed a target ventilation. The latter servo-control has an adjustable gain, so that subjects with for example Cheyne Stokes breathing can be treated using a very high servo gain to over-ride their own waxing and waning patterns; subjects with various central hypoventilation syndromes can be treated with a low servo gain, so that short central apneas are permitted, for example to cough, clear the throat, talk, or roll over in bed, but only if they follow a previous period of high ventilation; and normal subjects are treated with an intermediate gain.
[0000] Restating the Above in Other Words:
[0000]
The integral gain of the servo-control of the degree of assistance is adjustable from very fast (0.3 cmH 2 O/L/sec/sec) to very slow. Patients with Cheyne-Stokes breathing have a very high ventilatory control loop gain, but a long control loop delay, leading to hunting. By setting the loop gain even higher, the patient's controller is stabilized. This prevents the extreme breathlessness that normally occurs during each cycle of Cheyne-Stokes breathing, and this is very reassuring to the patient. It is impossible for them to have a central apnea. Conversely, subjects with obesity-hypoventilation syndrome have low or zero loop gain. They will not feel breathless during a central apnea. However, they have much mucus and need to cough, and are also often very fidgety, needing to roll about in bed. This requires that they have central apneas which the machine does not attempt to treat. By setting the loop gain very low, the patient is permitted to take a couple of deep breaths and then have a moderate-length central apnea while coughing, rolling over, etc, but prolonged sustained apneas or hypopneas are prevented.
Sudden changes in leakage flow are detected and handled using a fuzzy logic algorithm. The principle of the algorithm is that the leak filter time constant is reduced dynamically to the fuzzy extent that the apparent respiratory airflow is a long way from zero for a long time compared with the patient's expected respiratory cycle length.
Rather than simply triggering between two states (IPAP, EPAP), the device uses a fuzzy logic algorithm to estimate the position in the respiratory cycle as a continuous variable. The algorithm permits the smooth pressure waveform to adjust it's rise time automatically to the patient's instantaneous respiratory pattern.
The fuzzy phase detection algorithm under normal conditions closely tracks the patient's breathing. To the extent that there is a high or suddenly changing leak, or the patient's ventilation is low, the rate of change of phase (respiratory rate) smoothly reverts to the specified target respiratory rate. Longer or deeper hypopneas are permitted to the extent that ventilation is on average adequate. To the extent that the servo gain is set high to prevent Cheyne Stokes breathing, shorter and shallower pauses are permitted.
Airflow filtering uses an adaptive filter, which shortens it's time constant if the subject is breathing rapidly, to give very fast response times, and lenthens if the subject is breathing slowly, to help eliminate cardiogenic artifact.
The fuzzy changing leak detection algorithm, the fuzzy phase detection algorithm with its differential handling of brief expiratory pauses, and handling of changing leak, together with the smooth waveform severally and cooperatively make the system relatively immune to the effects of sudden leaks.
By suitably setting various parameters, the system can operate in CPAP, bilevel spontaneous, bilevel timed, proportional assist ventilation, volume cycled ventilation, and volume cycled servo-ventilation, and therefore all these modes are subsets of the present embodiment. However, the present embodiment permits states of operation that can not be achieved by any of the above states, and is therefore distinct from them.
Notes
Note 1: in this second embodiment, the names and symbols used for various quantities may be different to those used in the first embodiment.
Note 2: The term “swing” is used to refer to the difference between desired instantaneous pressure at end inspiration and the desired instantaneous pressure at end expiration.
Note 3: A fuzzy membership function is taken as returning a value between zero for complete nonmembership and unity for complete membership. Fuzzy intersection A AND B is the lesser of A and B, fuzzy union A OR B is the larger of A and B, and fuzzy negation NOT A is 1−A.
Note 4: root(x) is the square root of x, abs(x) is the absolute value of x, sign(x) is −1 if x is negative, and +1 otherwise. An asterisk (*) is used to explicitly indicate multiplication where this might not be obvious from context.
Apparatus
[0182] The apparatus for the second embodiment is shown in FIG. 1 b . The blower 110 delivers air under pressure to the mask 111 via the air delivery hose 112 . Exhaled air is exhausted via the exhaust 113 in the mask 111 . The pneumotachograph 114 and a differential pressure transducer 115 measure the airflow in the nose 112 . The flow signal is delivered to the microprocessor 116 . Pressure at any convenient point 117 along the nose 112 is measured using a pressure transducer 118 . The output from the pressure transducer 118 is delivered to the microcontroller 116 and also to a motor servo 119 . The microprocessor 116 supplies the motor servo 119 with a pressure request signal, which is then compared with the signal from the pressure transducer 118 to control the blower motor 120 . User configurable parameters are loaded into the microprocessor 116 via a communications port 121 , and the computed mask pressure and flow can if desired be output via the communications port 121 .
[0000] Initialization
[0183] The following user adjustable parameters are specified and stored:
max permissible maximum permissible mask pressure pressure max swing maximum permissible difference between end inspiratory pressure and end expiratory pressure. min swing minimum permissible difference between end inspiratory pressure and end expiratory pressure. epap end expiratory pressure min permissible minimum permissible mask pressure pressure target ventilation minute ventilation is sevo-controlled to equal or exceed this quantity target frequency Expected respiratory rate. If the patient is achieving no respiratory airflow, the pressure will cycle at this frequency. target duty cycle Expected ratio of inspiratory time to cycle time. If the patient is achieving no respiratory airflow, the pressure will follow this duty cycle. linear resistance resistive unloading = linear resistance * f + andquad resistance quad_resistance * f 2 sign(f), where f is the respiratory airflow. where sign(x) = −1 for x < 0, +1 otherwise elastance Unload at least this much elastance servo gain gain for servo-control of minute ventilation to at least exceed target ventilation. waveform time constant Elastic unloading waveform time constant as a fraction of inspiratory duration. (0.0 = square wave) hose resistance ΔP from pressure sensing port to inside mask = hose resistance times the square of the flow in the intervening tubing. diffuser conductance Flow through the mask exhaust port = diffuser conductance * root mask pressure
At initialization, the following are calculated from the above user-specified settings:
The expected duration of a respiratory cycle, of an inspiration, and of an expiration are set respectively to:
STDT TOT =60/target respiratory rate
STDT I =STDT TOT *target duty cycle
STDT E =STDT TOT −STDT I
The standard rates of change of phase (revolutions per sec) during inspiration and expiration are set respectively to:
STDdφ I =0.5 /STDT I
STDdφ E =0.5 /STDT E
The instantaneous elastic support at any phase φ in the respiratory cycle is given by:
PEL (φ)=swing*Π(φ)
[0184] where swing is the pressure at end inspiration minus the pressure at end expiration,
π(Φ) = e −2 τΦ during inspiration, e −4 t(Φ − 0.5) during expiration
and τ is the user-selectable waveform time constant.
If τ=0, then Π(φ) is a square wave. The maximum implemented value for τ=0.3, producing a waveform approximately as shown in FIG. 5 .
The mean value of Π(φ) is calculated as follows:
Π BAR = 0.5 ∫ 0 .05` Π ( ϕ ) ⅆ ϕ
Operations Performed Every 20 Milliseconds
[0185] The following is an overview of routine processing done at 50 Hz:
measure flow at flow sensor and pressure at pressure sensing port calculate mask pressure and flow from sensor pressure and flow calculate conductance of mask leak calculate instantaneous airflow through leak calculate respiratory airflow and low pass filtered respiratory airflow calculate mask on-off status and lead-in calculate instantaneous and recent peak jamming calculate time constant for leak conductance calculations calculate phase in respiratory cycle update mean rates of change of phase for inspiration and expiration, lengths of inspiratory and expiratory times, and respiratory rate add hose pressure loss to EPAP pressure add resistive unloading calculate instantaneous elastic assistance required to servo-control ventilation estimate instantaneous elastic recoil pressure using various assumptions weight and combine estimates add servo pressure to yield desired sensor pressure servo-control motor speed to achieve desired sensor pressure
The details of each step will now be explained.
Measurement of Flow and Pressure
Flow is measured at the outlet of the blower using a pneumotachograph and differential pressure transducer. Pressure is measured at any convenient point between the blower outlet and the mask. A humidifier and/or anti-bacterial filter may be inserted between the pressure sensing port and the blower. Flow and pressure are digitized at 50 Hz using an A/D converter.
Calculation of Mask Flow and Pressure
The pressure loss from pressure measuring point to mask is calculated from the flow at the blower and the (quadratic) resistance from measuring point to mask.
Hose pressure loss=sign(flow)*hose resistance*flow 2
where sign(x)=−1 for x<0, +1 otherwise. The mask pressure is then calculated by subtracting the hose pressure loss from the measured sensor pressure:
Mask pressure=sensor pressure−hose pressure loss
The flow through the mask exhaust diffuser is calculated from the known parabolic resistance of the diffuser holes, and the square root of the mask pressure:
diffuser flow=exhaust resistance*sign(mask pressure)*root(abs(mask pressure))
Finally, the mask flow is calculated:
mask flow=sensor flow−diffuser flow
The foregoing describes calculation of mask pressure and flow in the various treatment modes. In diagnostic mode, the patient is wearing only nasal cannulae, not a mask. The cannula is plugged into the pressure sensing port. The nasal airflow is calculated from the pressure, after a linearization step, and the mask pressure is set to zero by definition.
Conductance of Leak
The conductance of the leak is calculated as follows:
root mask pressure=sign(P MASK )√{square root over (abs(P MASK ))}
LP mask airflow=low pass filtered mask airflow
LP root mask pressure=low pass filtered root mask pressure
conductance of leak=LP mask airflow/LP root mask pressure
The time constant for the two low pass filtering steps is initialized to 10 seconds and adjusted dynamically thereafter (see below).
Instantaneous Flow Through Leak
The instantaneous flow through the leak is calculated from the instantaneous mask pressure and the conductance of the leak:
instantaneous leak=conductance of leak*root mask pressure
Respiratory Airflow
The respiratory airflow is the difference between the flow at the mask and the instantaneous leak:
respiratory airflow=maskflow−instantaneous leak
Low Pass Filtered Respiratory Airflow
Low pass filter the respiratory airflow to remove cardiogenic airflow and other noise. The time constant is dynamically adjusted to be 1/40 of the current estimated length of the respiratory cycle T TOT (initialized to STD_T TOT and updated below). This means that at high respiratory rates, there is only a short phase delay introduced by the filter, but at low respiratory rates, there is good rejection of cardiogenic airflow.
Mask On/Off Status
The mask is assumed to initially be off. An off-on transition is taken as occurring when the respiratory airflow first goes above 0.2 L/sec, and an on-off transition is taken as occurring if the mask pressure is less than 2 cmH 2 O for more than 1.5 seconds.
Lead-In
Lead-in is a quantity that runs from zero if the mask is off, or has just been donned, to 1.0 if the mask has been on for 20 seconds or more, as shown in FIG. 6 .
Calculation of Instantaneous Jamming Index, J
J is the fuzzy extent to which the impedance of the leak has suddenly changed. It is calculated as the fuzzy extent to which the absolute magnitude of the respiratory airflow is large for longer than expected.
The fuzzy extent A I to which the airflow has been positive for longer than expected is calculated from the time t ZI since the last positive-going zero crossing of the calculated respiratory airflow signal, and the expected duration STD T I of a normal inspiration for the particular subject, using the fuzzy membership function shown in FIG. 7 .
The fuzzy extent B I to which the airflow is large and positive is calculated from the instantaneous respiratory airflow using the fuzzy membership function shown in FIG. 8 .
The fuzzy extent I I to which the leak has suddenly increased is calculated by calculating the fuzzy intersection (lesser) of A I and B I .
Precisely symmetrical calculations are performed for expiration, deriving I E .as the fuzzy extent to which the leak has suddenly decreased. A E is calculated from T ZE and T E , B E is calculated from minus f RESP , and I E is the fuzzy intersection of A E and B E . The instantaneous jamming index J is calculated as the fuzzy union (larger) of indices I I and I E .
Recent Peak Jamming
If the instantaneous jamming index is larger than the current value of the recent peak jamming index, then the recent peak jamming index is set to equal the instantaneous jamming index. Otherwise, the recent peak jamming index is set to equal the instantaneous jamming index low pass filtered with a time constant of 10 seconds. An electrical analogy of the calculation is shown in FIG. 9 .
Time Constant for Leak Conductance Calculations
If the conductance of the leak suddenly changes, then the calculated conductance will initially be incorrect, and will gradually approach the correct value at a rate which will be slow if the time constant of the low pass filters is long, and fast if the time constant is short. Conversely, if the impedance of the leak is steady, the longer the time constant the more accurate the calculation of the instantaneous leak. Therefore, it is desirable to lengthen the time constant to the extent that the leak is steady, reduce the time constant to the extent that the leak has suddenly changed, and to use intermediately longer or shorter time constants if it is intermediately the case that the leak is steady.
If there is a large and sudden increase in the conductance of the leak, then the calculated respiratory airflow will be incorrect. In particular, during apparent inspiration, the calculated respiratory airflow will be large positive for a time that is large compared with the expected duration of a normal inspiration. Conversely, if there is a sudden decrease in conductance of the leak, then during apparent expiration the calculated respiratory airflow will be large negative for a time that is large compared with the duration of normal expiration.
Therefore, the time constant for the calculation of the conductance of the leak is adjusted depending on J PEAK , which is a measure of the fuzzy extent that the leak has recently suddenly changed, as shown in FIG. 10 .
In operation, to the extent that there has recently been a sudden and large change in the leak, J PEAK will be large, and the time constant for the calculation of the conductance of the leak will be small, allowing rapid convergence on the new value of the leakage conductance. Conversely, if the leak is steady for a long time, J PEAK will be small, and the time constant for calculation of the leakage conductance will be large, enabling accurate calculation of the instantaneous respiratory airflow. In the spectrum of intermediate situations, where the calculated instantaneous respiratory airflow is larger and for longer periods, J PEAK will be progressively larger, and the time constant for the calculation of the leak will progressively reduce. For example, at a moment in time where it is uncertain whether the leak is in fact constant, and the subject has merely commenced a large sigh, or whether in fact there has been a sudden increase in the leak, the index will be of an intermediate value, and the time constant for calculation of the impedance of the leak will also be of an intermediate value. The advantage is that some corrective action will occur very early, but without momentary total loss of knowledge of the impedance of the leak.
Instantaneous Phase in Respiratory Cycle
The current phase φ runs from 0 for start of inspiration to 0.5 for start of expiration to 1.0 for end expiration=start of next inspiration. Nine separate features (peaks, zero crossings, plateaux, and some intermediate points) are identified on the waveform, as shown in FIG. 11 .
Calculation of Normalized Respiratory Airflow
The filtered respiratory airflow is normalized with respect to the user specified target ventilation as follows:
standard airflow=target ventilation/7.5 L/min
f′=filtered respiratory airflow/standard airflow
Next, the fuzzy membership in fuzzy sets large negative, small negative, zero, small positive, and large positive, describing the instantaneous airflow is calculated using the membership functions shown in FIG. 12 . For example, if the normalized airflow is 0.25, then the airflow is large negative to extent 0.0, small negative to extent 0.0, zero to extent 0.5, small positive to extent 0.5, large positive to extent 0.00.
Calculation of Normalized Rate of Change of Airflow
The rate of change of filtered respiratory airflow is calculated and normalized to a target ventilation of 7.5 L/min at 15 breaths/min as follows:
standard df/dt =standard airflow*target frequency/15
calculate d(filtered airflow)/dt
low pass filter with a time constant of 8/50 seconds
normalize by dividing by standard df/dt
Now evaluate the membership of normalized df/dt in the fuzzy sets falling, steady, and rising, whose membership functions are shown in FIG. 13 .
Calculation of Ventilation, Normalized Ventilation, and Hypopnea
ventilation=abs(respiratory airflow), low pass filtered with a time constant of STDT TOT .
normalized ventilation=ventilation/standard airflow
Hypopnea is the fuzzy extent to which the normalized ventilation is zero. The membership function for hypopnea is shown in FIG. 14 .
Calculation of Recent Ventilation, Normalized Recent Ventilation, and Hyperpnea
Recent ventilation is also a low pass filtered abs(respiratory airflow), but filtered with an adjustable time constant, calculated from servo gain (specified by the user) as shown in FIG. 15 . For example, if the servo gain is set to the maximum value of 0.3, the time constant is zero, and recent ventilation equals instantaneous abs(respiratory airflow). Conversely, if servo gain is zero, the time constant is twice STD T TOT , the expected length of a typical breath.
Target absolute airflow=2*target ventilation
normalized recent ventilation=recent ventilation/target absolute airflow
Hyperpnea is the fuzzy extent to which the recent ventilation is large. The membership function for hyperpnea is shown in FIG. 16 .
Big Leak
The fuzzy extent to which there is a big leak is calculated from the membership function shown in FIG. 17 .
Additional Fuzzy Sets Concerned with Fuzzy “Triggering”
Membership in fuzzy sets switch negative and switch positive are calculated from the normalized respiratory airflow using the membership functions shown in FIG. 18 , and membership in fuzzy sets insp_phase and exp_phase are calculated from the current phase f using the membership functions shown in FIG. 19 .
Fuzzy Inference Rules for Phase
Procedure W(y) calculates the area of an isosceles triangle of unit height and unit base, truncated at height y as shown in FIG. 20 . In the calculations that follow, recall that fuzzy intersection a AND b is the smaller of a and b, fuzzy union a OR b is the larger of a and b, and fuzzy negation NOT a is 1−a.
The first fuzzy rule indicates that lacking any other information the phase is to increase at a standard rate. This rule is unconditionally true, and has a very heavy weighting, especially if there is a large leak, or there has recently been a sudden change in the leak, or there is a hypopnea.
W STANDARD =8+16 *J PEAK +16*hyopopnea+16*big leak
The next batch of fuzzy rules correspond to the detection of various features of a typical flow-vs-time curve. These rules all have unit weighting, and are conditional upon the fuzzy membership in the indicated sets:
W EARLY INSP =W (rise and small positive)
W PEAK INSP =W (large positive AND steady AND NOT recent peak jamming)
W LATE INSP =W (fall AND small positive)
W EARLY EXP =W (fall AND small negative)
W PEAK EXP =W (large negative AND steady)
W LATE EXP =W (rise AND small negative)
The next rule indicates that there is a legitimate expiratory pause (as opposed to an apnea) if there has been a recent hyperpnea and the leak has not recently changed:
W PAUSE =(hyperpnea AND NOT J PEAK )* W (steady AND zero)
Recalling that the time constant for hyperpnea gets shorter as servo gain increases, the permitted length of expiratory pause gets shorter and shorter as the servo gain increases, and becomes zero at maximum servo gain. The rationale for this is that (i) high servo gain plus long pauses in breathing will result in “hunting” of the servo-controller, and (ii) in general high servo gain is used if the subject's chemoreceptor responses are very brisk, and suppression of long apneas or hypopneas will help prevent the subject's own internal servo-control from hunting, thereby helping prevent Cheyne-Stokes breathing.
Finally, there are two phase-switching rules. During regular quiet breathing at roughly the expected rate, these rules should not strongly activate, but they are there to handle irregular breathing or breathing at unusual rates. They have very heavy weightings.
W TRIG INSP =32 W (expiratory phase AND switch positive)
W TRIG EXP =32 W (inspiratory phase AND switch negative)
Defuzzification
[0203] For each of the ten fuzzy rules above, we attach phase angles f N , as shown in Table ZZZ. Note that φ are in revolutions, not radians. We now place the ten masses W(N) calculated above at the appropriate phase angles φ N around the unit circle, and take the centroid.
Rule N Φ N STANDARD 1 current Φ TRIG INSP 2 0.00 EARLY INSP 3 0.10 PEAK INSP 4 0.30 LATE INSP 5 0.50 TRIG EXP 6 0.5 + 0.05 k EARLY EXP 7 0.5 + 0.10 k PEAK EXP 8 0.5 + 0.20 k LATE EXP 9 0.5 + 0.4 k EXP PAUSE 10 0.5 + 0.5 k
where k=STD T I /STD T E .
Note that if the user has entered very short duty cycle, k will be small. For example a normal duty cycle is 40%, giving k= 40/60=0.67. Thus the expiratory peak will be associated with a phase angle of 0.5+0.2*0.67=0.63, corresponding 26% of the way into expiratory time, and the expiratory pause would start at 0.5+0.5*0.67=0.83, corresponding to 67% of the way into expiratory time. Conversely, if the duty cycle is set to 20% in a patient with severe obstructive lung disease, features 6 through 10 will be skewed or compressed into early expiration, generating an appropriately longer expiratory pause.
The new estimate of the phase is the centroid, in polar coordinates, of the above ten rules:
centroid = arc tan ( ∑ W N sin ϕ N ∑ W N cos ϕ N )
The change in phase dφ from the current phase φ to the centroid is calculated in polar coordinates. Thus if the centroid is 0.01 and the current phase is 0.99, the change in phase is dφ=0.02. Conversely, if the centroid is 0.99 and the current phase is 0.01, then dφ=−0.02. The new phase is then set to the centroid:
φ=centroid
This concludes the calculation of the instantaneous phase in the respiratory cycle φ.
Estimated Mean Duration of Inspiration, Expiration, Cycle Time, and Respiratory Rate
If the current phase is inspiratory (φ<0.5) the estimated duration of inspiration T I is updated:
LP ( dφ I )=low pass filtered dφ with a time constant of 4 *STDT TOT
Clip LP(dφ I ) to the range (0.5/STDT I )/2 to 4(0.5/STDT I )
T I =0.5/clipped LP ( dφI )
Conversely, if the current phase is expiratory, (φ>=0.5) the estimated duration of expiration T E is updated:
LP ( dφ E )=low pass filtered dφ with a time constant of 4 *STDT TOT
Clip LP(dφE) to the range (0.5/STDT E )/2 to 4(0.5/STDT E )
T E =0.5/clipped LP ( dφ E )
The purpose of the clipping is firstly to prevent division by zero, and also so that the calculated T I and T E are never more than a factor of 4 shorter or a factor of 2 longer than expected.
Finally, the observed mean duration of a breath T TOT and respiratory rate RR are:
T TOT =T I +T E
RR= 60 /T TOT
Resistive Unloading
The resistive unloading is the pressure drop across the patient's upper and lower airways, calculated from the respiratory airflow and resistance values stored in SRAM
f=respiratory airflow truncated to +/−2 L/sec
resistive unloading=airway resistance* f +upper airway resistance* f 2 *sign( f )
Instantaneous Elastic Assistance
The purpose of the instantaneous elastic assistance is to provide a pressure which balances some or all of the elastic deflating pressure supplied by the springiness of the lungs and chest wall (instantaneous elastic pressure), plus an additional component required to servo-control the minute ventilation to at least exceed on average a pre-set target ventilation. In addition, a minimum swing, always present, is added to the total. The user-specified parameter elastance is preset to say 50-75% of the known or estimated elastance of the patient's lung and chest wall. The various components are calculated as follows:
Instantaneous Assistance Based on Minimum Pressure Swing Set by Physician:
instantaneous minimum assistance=minimum swing*Π(φ)
Elastic Assistance Required to Servo-Control Ventilation to Equal or Exceed Target
The quantity servo swing is the additional pressure modulation amplitude required to servo-control the minute ventilation to at least equal on average a pre-set target ventilation.
Minute ventilation is defined as the total number of litres inspired or expired per minute. However, we can't wait for a whole minute, or even several seconds, to calculate it, because we wish to be able to prevent apneas or hypopneas lasting even a few seconds, and a PI controller based on an average ventilation over a few seconds would be either sluggish or unstable.
The quantity actually servo-controlled is half the absolute value of the instantaneous respiratory airflow. A simple clipped integral controller with no damping works very satisfactorily. The controller gain and maximum output ramp up over the first few seconds after putting the mask on.
If we have had a sudden increase in mouth leak, airflow will be nonzero for a long time. A side effect is that the ventilation will be falsely measured as well above target, and the amount of servo assistance will be falsely reduced to zero. To prevent this, to the extent that the fuzzy recent peak jamming index is large, we hold the degree of servo assistance at its recent average value, prior to the jamming.
The algorithm for calculating servo swing is as follows:
error=target ventilation−abs(respiratory airflow)/2
servo swing= S error*servo gain*sample interval
clip servo swing to range 0 to 20 cmH 2 O*lead-in
set recent servo swing=servo swing low pass filtered with a time constant of 25 sec.
clip servo swing to be at most J PEAK *recent servo swing
The instantaneous servo assistance is calculated by multiplying servo swing by the previously calculated pressure waveform template:
instantaneous servo assistance=servo swing*Π(φ)
Estimating Instantaneous Elastic Pressure
The instantaneous pressure required to unload the elastic work of inspiring against the user-specified elastance is the specified elastance times the instantaneous inspired volume. Unfortunately, calculating instantaneous inspired volume simply by integrating respiratory airflow with respect to time does not work in practice for three reasons: firstly leaks cause explosive run-away of the integration. Secondly, the integrator is reset at the start of each inspiration, and this point is difficult to detect reliably. Thirdly, and crucially, if the patient is making no efforts, nothing will happen.
Therefore, four separate estimates are made, and a weighted average taken.
Estimate 1: Exact instantaneous elastic recoil calculated from instantaneous tidal volume, with a correction for sudden change in leak
The first estimate is the instantaneous elastic recoil of a specified elastance at the estimated instantaneous inspired volume, calculated by multiplying the specified elastance by the integral of a weighted respiratory airflow with respect to time, reset to zero if the respiratory phase is expiratory. The respiratory airflow is weighted by the fuzzy negation of the recent peak jamming index J PEAK , to partly ameliorate an explosive run-away of the integral during brief periods of sudden increase in leak, before the leak detector has had time to adapt to the changing leak. In the case where the leak is very steady, J PEAK will be zero, the weighting will be unity, and the inspired volume will be calculated normally and correctly. In the case where the leak increases suddenly, J PEAK will rapidly increase, the weighting will decrease, and although typically the calculated inspired volume will be incorrect, the over-estimation of inspired volume will be ameliorated. Calculations are as follows:
Instantaneous volume=integral of respiratory airflow*(1− J PEAK ) dt
if phase is expiratory (0.5<φ<1.0 revolutions) reset integral to zero
estimate 1=instantaneous volume*elastance
Estimate 2: based on assumption that the tidal volume equals the target tidal volume
The quantity standard swing is the additional pressure modulation amplitude that would unload the specified elastance for a breath of a preset target tidal volume.
target tidal volume=target ventilation/target frequency
standard swing=elastance*target tidal volume
estimate 2=standard swing*Π(φ)
Estimate 3: based on assumption that the tidal volume equals the target tidal volume divided by the observed mean respiratory rate RR calculated previously.
Estimate 3=elastance*target ventilation/RR*Π(φ)
Estimate 4: based on assumption that this breath is much like recent breaths
The instantaneous assistance based on the assumption that the elastic work for this breath is similar to that for recent breaths is calculated as follows:
LP elastic assistance=instantaneous elastic assistance low pass filtered with a time constant of 2 STDT TOT
estimate 4= LP elastic assistance*Π(φ)/ P BAR
[0204] The above algorithm works correctly even if Π(φ) is dynamically changed on-the-fly by the user, from square to a smooth or vice versa. For example, if an 8 cmH 2 O square wave (Π BAR =1) adequately assists the patient, then a sawtooth wave (Π BAR =0.5) will require 16 cmH 2 O swing to produce the same average assistance.
[0000] Best Estimate of Instantaneous Elastic Recoil Pressure
[0205] Next, calculate the pressure required to unload a best estimate of the actual elastic recoil pressure based on a weighted average of the above. If Π(φ) is set to the smoothest setting, the estimate is based equally on all the above estimates of instantaneous elastic recoil. If Π(φ) is a square wave, the estimate is based on all the above estimates except for estimate 1, because a square wave is maximal at φ=0, whereas estimate 1 is zero at φ=0. Intermediate waveforms are handled intermediately. Quantity smoothness runs from zero for a square wave to 1 for a waveform time constant of 0.3 or above.
smoothness=waveform time constant/0.3
instantaneous recoil=(smoothness*estimate 1+estimate 2+estimate 3+estimate 4)/(smoothness+3)
Now add the estimates based on minimum and servo swing, truncate so as not to exceed a maximum swing set by the user. Reduce (lead in gradually) if the mask has only just been put on.
I=instantaneous minimum assistance+instantaneous servo assistance+instantaneous recoil
Truncate I to be less than preset maximum permissible swing instantaneous elastic assistance= I *lead-in
This completes the calculation of instantaneous elastic assistance.
Desired Pressure at Sensor
desired sensor pressure= epap +hose pressure loss+resistive unloading+instantaneous elastic assistance
Servo Control of Motor Speed
[0206] In the final step, the measured pressure at the sensor is servo-controlled to equal the desired sensor pressure, using for example a clipped pseudodifferential controller to adjust the motor current. Reference can be made to FIG. 1 in this regard.
[0000] Device Performance
[0207] FIGS. 21-27 each show an actual 60 second recording displaying an aspect of the second embodiment. All recordings are from a normal subject trained to perform the required manoeuvres. Calculated respiratory airflow, mask pressure, and respiratory phase are calculated using the algorithms disclosed above, output via a serial port, and plotted digitally.
[0208] In FIGS. 21-26 respiratory airflow is shown as the darker tracing, the vertical scale for flow being ±L/sec, inspiration upwards. The vertical scale for the pressure (light trace) is 0.2 cmH 2 O.
[0209] FIG. 21 is recorded with the servo gain set to 0.1 cmH 2 O/L/sec/sec, which is suitable for subjects with normal chemoflexes. The subject is breathing well above the minimum ventilation, and a particularly deep breath (sigh) is taken at point (a). As is usual, respiratory effort ceases following the sigh, at point (c). The device correctly permits a short central apnea (b), as indicated by the device remaining at the end expiratory pressure during the period marked (b). Conversely FIG. 22 shows that if there is no preceding deep breath, when efforts cease at (a), the pressure correctly continues to cycle, thus preventing any hypoxia. FIG. 23 is recorded with servo gain set high, as would be appropriate for a subject with abnormally high chemoreflexes such as is typically the case with Cheyne-Stokes breathing. Now when effort ceases at arrow (a), pressure continues to cycle and a central apnea is no longer permitted, despite preceding deep breathing. This is advantageous for preventing the next cycle of Cheyne-Stokes breathing.
[0210] The above correct behaviour is also exhibited by a time mode device, but is very different to that of a spontaneous mode bilevel device, or equally of proportional assist ventilation, both of which would fail to cycle after all central apneas, regardless of appropriateness.
[0211] FIG. 24 shows automatically increasing end-inspiratory pressure as the subject makes voluntarily deeper inspiratory efforts. The desirable behaviour is in common with PAV, but is different to that of a simple bilevel device, which would maintain a constant level of support despite an increased patient requirement, or to a volume cycled device, which would actually decrease support at a time of increasing need.
[0212] FIG. 25 is recorded with a somewhat more square waveform selected. This figure shows automatically increasing pressure support when the subject voluntarily attempts to resist by stiffening the chest wall at point (a). This desirable behaviour is common with PAV and volume cycled devices, with the expectation that PAV cannot selectively deliver a squarer waveform. It is distinct from a simple bilevel device which would not augment the level of support with increasing need.
[0213] FIG. 26 shows that with sudden onset of a severe 1.4 L/sec leak at (a), the flow signal returns to baseline (b) within the span of a single breath, and pressure continues to cycle correctly throughout. Although timed mode devices can also continue to cycle correctly in the face of sudden changing leak, the are unable to follow the subject's respiratory rate when required (as shown in FIG. 27 ). Other known bilevel devices and PAV mis-trigger for longer or shorter periods following onset of a sudden sever leak, and PAV can deliver greatly excessive pressures under these conditions.
[0214] FIG. 27 shows an actual 60 second tracing showing respiratory airflow (heavy trace ±1 L/sec full scale) and respiratory phase as a continuous variable (light trace, 0 to 1 revolution), with high respiratory rate in the left half of the trace and low respiratory rate in the right half of the trace. This trace demonstrates that the invention can determine phase as a continuous variable.
Advantageous Aspects of Embodiments of the Invention
[0000] Use of Phase as a Continuous Variable.
[0215] In the prior art, phase is taken as a categorical variable, with two values: inspiration and expiration. Errors in the detection of start of inspiration and start of expiration produce categorical errors in delivered pressure. Conversely, here, phase is treated as a continuous variable having values between zero and unity. Thus categorical errors in measurement of phase are avoided.
[0000] Adjustable Filter Frequency and Allowance for Phase Delay
[0216] By using a short time constant when the subject is breathing rapidly, and a long time constant when the subject is breathing slowly, the filter introduces a fixed phase delay which is always a small fraction of a respiratory cycle. Thus unnecessary phase delays can be avoided, but cardiogenic artifact can be rejected in subjects who are breathing slowly. Furthermore, because phase is treated as a continuous variable, it is possible to largely compensate for the delay in the low pass filter.
[0000] Within-Breath Pressure Regulation as a Continuous Function of Respiratory Phase.
[0217] With all prior art there is an intrusive discontinuous change in pressure, either at the start of inspiration or at the start of expiration. Here, the pressure change is continuous, and therefore more comfortable.
[0218] With proportional assist ventilation, the instantaneous pressure is a function of instantaneous volume into the breath. This means that a sudden large leak can cause explosive pressure run-away. Here, where instantaneous pressure is a function of instantaneous phase rather than tidal volume, this is avoided.
[0000] Between-Breath Pressure-Regulation as a Function of Average Inspiratory Duration.
[0219] Average inspiratory duration is easier to calculate in the presence of leak than is tidal volume. By taking advantage of a correlation between average inspiratory duration and average tidal volume, it is possible to adjust the amplitude of modulation to suit the average tidal volume.
[0000] Provision of a Pressure Component for Unloading Turbulent Upper Airway Resistance, and Avoiding Cardiogenic Pressure Instabilities.
[0220] Although Younes describes the use of a component of pressure proportional to the square of respiratory airflow to unload the resistance of external apparatus, the resistance of the external apparatus in embodiments of the present invention is typically negligible. Conversely, embodiments of the present invention describes two uses for such a component proportional to the square of respiratory airflow that were not anticipated by Younes. Firstly, sleeping subjects, and subjects with a blocked nose, have a large resistance proportional to the square of airflow, and a pressure component proportional to the square of airflow can be used to unload the anatomical upper airway resistance. Secondly, small nonrespiratory airflow components due to heartbeat or other artifact, when squared, produces negligible pressure modulation, so that the use of such a component yields relative immunity to such nonrespiratory airflow.
[0000] Smooth Transition Between Spontaneous and Controlled Breathing
[0221] There is a smooth, seamless gradation from flexibly tracking the subject's respiratory pattern during spontaneous breathing well above the target ventilation, to fully controlling the duration, depth, and phase of breathing if the subject is making no efforts, via a transitional period in which the subject can make progressively smaller changes to the timing and depth of breathing. A smooth transition avoids categorization errors when ventilation is near but not at the desired threshold. The advantage is that the transition from spontaneous to controlled ventilation occurs unobtrusively to the subject. This can be especially important in a subject attempting to go to sleep. A similar smooth transition can occur in the reverse direction, as a subject awakens and resumes spontaneous respiratory efforts. | The apparatus provides for the determination of the instantaneous phase in the respiratory cycle, subject's average respiration rate and the provision of ventilatory assistance. A microprocessor ( 16 ) receives an airflow signal from a pressure transducer ( 18 ) coupled to a port ( 17 ) at a mask ( 11 ). The microprocessor ( 16 ) controls a servo ( 19 ), that in turn controls the fan motor ( 20 ) and thus the pressure of air delivered by the blower ( 10 ). The blower ( 10 ) is coupled to a subject's mask (ii) by a conduit ( 12 ). The invention seeks to address the following goals: while the subject is awake and making substantial efforts the delivered assistance should be closely matched in phase with the subject's efforts; the machine should automatically adjust the degree of assistance to maintain at least a specified minimum ventilation without relying on the integrity of the subject's chemoreflexes; and it should continue to work correctly in the pesence of large leaks. | big_patent |
BACKGROUND OF THE INVENTION
This invention relates to surgical instruments and, more particularly, to a novel electro-surgical dissection and cauterization instrument for use primarily in laparoscopic/endoscopic procedures.
Many surgical procedures of today involving the removal and/or cauterization of tissue (e.g. endometriosis, lysis of adhesions, cholecystectomy, appendectomy, etc.) are performed with an electro-surgical dissection and cauterization instrument either in open surgery where the surgeon has direct view and access to the operation site, or in combination with an endoscope. Referring to the endoscopic surgery and, in particular, laparoscopic surgery which refers specifically to the abdominal area, the surgeon first makes usually several small, spaced incisions through the abdominal wall of the anesthetized patient. A source of compressed CO 2 is then delivered through one of the incisions to inflate the abdomen which effectively raises the abdominal wall above the organs and intestines of the patient. A space is thereby created therebetween which facilitates manipulation of surgical instruments which have been inserted into the abdomen through one of the incisions.
The surgeon views the internal operation site with a laparoscope which is a specialized type of scope inserted into the abdomen through an incision. The laparoscope is attached to a miniaturized, surgical camera assembly which operates by transmitting the image the camera is directed at inside the abdomen of the patient to the laparoscope eyepiece and/or a CRT screen in the operating room. A trochar is typically positioned within the incision to provide a smooth passageway for the instruments into and out of the abdomen. The electro-surgical instrument passes through the trochar to reach and perform surgery on the patient by the surgeon carefully manipulating the exposed end of the instrument.
Electro-surgical instruments are used primarily to separate and remove diseased tissue from healthy tissue such as polyps from the colon, for example. They are also used as probes to move tissue about during exploratory surgery. Supplying the instrument with controlled, electrical energy is well known in the art. With the patient properly grounded, a high frequency electric current is discharged at the distal, electrode end of the tool which augments its cutting capability while simultaneously cauterizing bleeding tissue and blood vessels. The electro-surgical instrument includes a proximal end with a plug permitting connection of the tool to an electro-surgical unit which supplies electric energy to the distal, electrode end of the tool. A rigid, linear insulating sleeve surrounds the instrument which delivers electric energy from the proximal, plug end to the distal, electrode end which itself is formed of electrically conductive material such as stainless steel.
The instrument's distal electrode may be found in a variety of configurations, each different configuration serving a different, specific function. For example, a working tip electrode in the shape of a snare or hook is used for grasping and pulling at tissue while a working tip electrode in the shape of a flattened spatula is used primarily to move tissue about and/or to cauterize bleeding tissue. Many other working tip electrode configurations appear on the market every day as the needs and likes of surgeons change.
In most, if not all, of the dissecting tools available today, the working tip electrode of the instrument just described extends directly from the distal end of the insulating sleeve. As such, there is a minimum of distance between the sleeve and the working tip electrode which, in many instances of use, obstructs or impairs the surgeon's view of the operation site as viewed in either complete open surgery or with a laparoscope during the procedure just described. The problem exists due to the small size of the working tip electrode in relation to the relatively large diameter of the sleeve from which it extends.
A second problem surgeons have reported when using present day electro-surgical instruments is that the portion of the working tip electrode directly adjacent the sleeve occasionally makes inadvertent contact with healthy tissue surrounding the surgical work site. This has resulted in unintentional cauterization of healthy tissue which poses serious consequences to both patient and surgeon alike.
It is therefore a principle object of the present invention to provide an electro-surgical instrument including a rigid arm extending between the distal, working tip electrode and the insulating sleeve. The arm includes at least a portion thereof laterally offset from the longitudinal axis of the sleeve whereby obstruction of the surgeon's view of the working tip electrode and surgical work site by the sleeve is substantially reduced.
It is a further object of the present invention to provide an electro-surgical instrument which provides an electrical insulating layer along the entire length of the tool up to the exposed working tip electrode such that inadvertent cauterization of tissue with portions of the tool other than the working tip electrode is eliminated.
It is another object of the present invention to provide a single-use, disposable, electro-surgical and cauterizing instrument for endoscopic procedures which is designed for easy handling and use by the surgeon.
Other objects will in part be obvious and in part appear hereinafter.
SUMMARY OF THE INVENTION
In accordance with the foregoing objects, the invention comprises an electro-surgical dissecting and cauterizing instrument for use primarily in standard endoscopic procedures which include the use of an endoscope to view the operation. The instrument has also proved very useful in open surgeries which do not include the use of an endoscope. An electric plug is included at the instrument's proximal end for connecting the tool to a conventional, electro-surgical unit which supplies high frequency electric energy to the working tip electrode of the tool at the control of the surgeon. The electric energy is delivered to the distal, working tip of the tool via a conductive rod surrounded by a linear, rigid sleeve formed of an insulating material, the sleeve extending from the plug end to the distal end of the tool which includes the working tip electrode.
The distal end of the tool includes an electrically conductive, rigid arm extending from the sleeve portion of the tool. Although several embodiments of the tool will be described in detail below, in each embodiment of the tool the arm extends from the sleeve and includes portions laterally offset from the longitudinal axis of the sleeve. The working tip electrode is formed at the free end of the arm and is used to make direct contact with the patient at the internal operation site. A thin jacket of insulating material is disposed upon the arm from the point where it extends from the sleeve right up to, but not including, the working tip electrode.
The working tip electrode comes in many different shapes depending on the needs of the surgeon in a particular surgical application. Electrode tips to be described in detail below include a hook and flattened spatula, for example. The fact that portions of the arm which extend between the sleeve and working tip are laterally offset from the main axis of the sleeve provides for maximum visualization of the working tip electrode and operation site by the surgeon.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side, elevational view of a first embodiment of the electro-surgical dissecting and cauterizing instrument shown operably connected to a conventional, electro-surgical unit in the intended manner;
FIG. 2 is a perspective, fragmentary view of the distal working tip end of the electro-surgical instrument seen in FIG. 1;
FIG. 3 is a side, elevational, enlarged view of the distal end of the electro-surgical instrument seen in FIG. 2;
FIG. 4 is a top view of FIG. 3;
FIG. 5 is a perspective, fragmentary view of a second embodiment of the distal end of the electro-surgical instrument;
FIG. 6 is an enlarged, side, elevational view of FIG. 5;
FIG. 7 is a bottom, fragmentary view of the working tip end of the arm as taken along the line 7--7 in FIG. 6;
FIG. 8 is a perspective, fragmentary view of the distal end of a third embodiment of the electro-surgical instrument;
FIG. 9 is an enlarged, side, elevational view of FIG. 8; and
FIG. 10 is a bottom, fragmentary view of the working tip end of the arm as seen along the line 10--10 in FIG. 9.
DETAILED DESCRIPTION
Referring now to the drawings, there is seen in FIG. 1 a first embodiment of the electro-surgical dissecting and cauterizing instrument 10 including a distal, working end 12 and a proximal end 14 which includes an electric plug such that instrument 10 may be releasably and operably connected to a conventional, electro-surgical control unit 16. Control unit 16 is supplied high frequency, electrical energy via power supply 18 and further includes a switch means 20 which is used to control the flow of electrical energy from unit 16 to instrument 10. As such, a surgeon manually grasps unit 16 to work instrument 10 as described below. Although unit 16 is shown and described herein for the purpose of illustrating a typical electrical unit with which instrument 10 would be used, it is understood that plug 14 may be easily adapted to connect to a variety of electro-surgical units available today.
Dissecting and cauterizing instrument 10 is used primarily in surgical procedures which may or may not include the use of an endoscope to view the operation site. For purposes of description, the surgical procedure using an endoscope will be discussed. Also, surgical procedures of the type discussed herein are termed laparoscopic because they target the abdominal area. The type of endoscope used in the abdomen is therefore termed a laparoscope. In particular, the surgeon inserts distal end 12 into the abdomen of the anesthetized patient through a trochar (not shown) positioned within an incision made in the abdominal wall. The operation site is viewed at the eyepiece of the laparoscope and/or on a CRT screen by passing the laparoscope (also not shown) through an adjacent incision in the abdomen which has been previously inflated with CO 2 as is customary surgical procedure in laparoscopic surgery of this type. The raising of the abdominal wall above the innards of the patient with the CO 2 creates a space therebetween which increases maneuverability of instrument 10 within the abdomen besides increasing the viewing area of the surgical site with the laparoscope. Examples of typical laparoscopic procedures in which dissecting and cauterizing instrument 10 would be used are lysis of adhesions, cholecystectomy and appendectomy.
Dissecting and cauterizing instrument 10 includes a rigid insulating sleeve 22 which surrounds conducting rod 24 extending from plug 14 to distal end 12. Distal end 12 is seen to include a rigid arm 26 extending from substantially the center of the distal end 21 of sleeve 22. A working tip 28 electrode in the shape of a hook in the embodiment of tool 10 seen in FIGS. 1-4 integrally extends from arm 26. Arm 26 and working tip electrode 28 are formed of electrically conductive material such as stainless steel and are supplied electrical energy via a conductive rod 24 extending through sleeve 22. A thin layer or jacket of insulating material 30 in the form of a TEFLON heat-shrink tubing is disposed upon arm 26 from sleeve 22 to the base of working tip electrode 28.
Prior art electro-surgical instruments of which the present inventors are aware do not include an arm such as 26 extending between the working tip electrode 28 and end of sleeve 22 but instead have their working tip electrodes extend directly from the sleeve. As such, the view of the operation site is obstructed because of the close proximity of the sleeve to the working tip electrode since the diameter of the sleeve is substantially larger than the size of the working tip electrodes. To overcome this problem, the present dissecting and cauterizing instrument 10 includes arm 26 to effectively space working tip electrode 28 from sleeve 22. Furthermore, arm 26 is seen to include portions laterally offset from the linear axis x--x extending through the center of sleeve 22 and arm 26. This feature also increases the visualization of the surgical work site by having the working tip electrode 28 extend from a portion of the arm 26 which lies along an axis y--y which is parallel to and spaced from linear axis x--x of sleeve 22.
Referring to FIG. 3, arm 26 is seen to extend linearly from sleeve 22 for a first length having a distance d 1 and bend downwardly at an approximately 150 degree angle a 1 , with respect thereto for a second length having a distance d 2 . Arm 26 then bends upwardly at an approximately 150 degree angle a 2 to extend for a third length having a distance d 3 . As such, it may be seen that the first length of arm 26 labeled d 1 extends along linear axis x--x of sleeve 22 which is spaced from and extends parallel to third length d 3 . Working tip electrode 28 is seen to integrally extend from the distal end of third length d 3 and bend toward axis x--x to form a hook which is used primarily for pulling at tissue.
The electricity which flows through arm 26 and electrode hook 28 at the control of the surgeon augments the cutting capability of hook 28 and cauterizes bleeding blood vessels. To prevent unintentional cauterization with portions of instrument 10 other than hook 28, an insulating jacket 30 is disposed upon the entire length of arm 26.
Referring to FIGS. 5 and 6, a second embodiment of instrument 10 is seen. In this second embodiment, arm 26' linearly extends from sleeve 22' for a first length having a distance D 1 as with the embodiment of FIGS. 1-4, bending downwardly and then upwardly at approximately 135 degree angles A 1 and A 2 for second and third lengths having distances of D 2 and D 3 , respectively. As such, the third length of arm 26' spanning distance D 3 lies along an axis Y--Y which is parallel to and spaced downwardly from the linear axis X--X of sleeve 22' where the first length of arm 26' spanning distance D 1 lies.
Arm 26' includes a third bend in an upwardly direction at an approximately 159 degree angle A 3 and extends linearly therefrom for a fourth length having a distance D 4 , crossing linear axis X--X such that the working tip electrode 32 lies on the side of axis X--X opposite to which axis Y--Y lies. It will be noticed in FIGS. 5-7 that working tip electrode 32 is in the shape of a flattened spatula which has a radial axis r--r which intersects linear axis Y--Y. Spatula 32 proves especially useful for cauterizing bleeding blood vessels rather than removing tissue from the patient's body. An insulating jacket 30' is disposed upon arm 26' from the distal end of sleeve 22' to the base of working tip electrode 32 to prevent any portion of arm 26' from unintentionally contacting and cauterizing healthy tissue surrounding the operation site.
Referring now to FIGS. 8, 9 and 10 which show yet a third embodiment of the invention, arm 26" is entirely linear and extends from sleeve 22" along an axis z--z which makes an approximately 6 degree acute angle A 4 with linear axis Z--Z of sleeve 22". Working tip electrode 32', which is also in the shape of a substantially circular, planar spatula, extends upwardly from arm 26" toward axis Z--Z. Working tip electrode 32' has a radial axis R--R which intersects linear axis Z--Z at an obtuse angle A 5 . An insulating jacket 30" is disposed upon arm 26" from sleeve 22" to working tip electrode 32'.
Based on the foregoing description of three embodiments of the invention, it may be realized that the length and configuration of the arms 26, 26' and 26" permit each of the respective working tip electrodes 30, 32 and 32' to be significantly spaced from and laterally offset from the longitudinal axis of the sleeve. This permits an enhanced viewing area of the surgical work site and working tip electrode for the surgeon. While the invention has been shown and described with particular reference to preferred embodiments thereof, it will be appreciated to those skilled in the art that variations in working tip electrode configuration and specific lengths and angles of the arm portion of the tool may be made to fit a particular surgical need without departing from the full scope of the invention as is set forth in the claims which follow. | An electro-surgical dissecting and cauterization tool comprises a linear, rigid insulating sleeve surrounding means providing an electric conducting path between a proximal, electric plug end and working tip electrode distal end. The plug attaches the tool to a conventional electro-surgical unit which supplies electrical energy to the working tip electrode end of the tool. A rigid arm extends between the sleeve and the working tip electrode and includes portions laterally offset from the main axis of the sleeve to increase visualization of the working tip electrode during surgery. | big_patent |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a magnetic resonance imaging apparatus of the type having a magnet with at least one patient receptacle and at least one support plate, as well as a predetermined number of transmit and/or receive coils, and which allows exposures with the subject in at least two predetermined exposure positions, with at least one exposure taking place using predetermined adjustment parameters.
2. Description of the Prior Art
In known magnetic resonance imaging apparatuses, for different exposure positions the associated exposure parameters must in general be modified at least partially. The exposure parameters that may have to be modified include e.g. the position of the support plate and the connection or disconnection of transmit and/or receive coils. As a rule, a modification of the exposure parameters requires a readjustment of the magnetic resonance imaging apparatus.
The adjustment essentially serves to optimize the RF chain (transmit and receive coils and associated amplifiers) and to optimize the homogeneity of the main magnetic field produced by the magnet (also called the basic magnetic field or B 0 field) in a volume under examination (imaging volume) located inside the patient receptacle. Due to the necessary homogeneity of the examination volume, this volume is also called the homogeneity volume.
The exposure parameters are also patient-dependent, since the patient represents an attenuation or damping for the transmit and/or receive coils. A precise adjustment thus also serves for patient safety with respect to the RF exposure.
In general, known magnetic resonance imaging apparatuses recognize automatically whether the. exposure parameters belonging. to particular exposure positions must be modified, and carry out a readjustment if warranted.
This adjustment normally requires 10 to 90 seconds per exposure position. Given certain examination procedures, this time is not available. This includes e.g. the tracking of doses of contrast agent over a larger body region that exceeds the available homogeneity volume of the nuclear spin resonance apparatus. In such cases, the patient must be guided by displacement of the support plate in a manner corresponding to the flow of contrast agent. If a smaller viewing field is not acceptable, the readjustment that is thereby required per imaging measurement (exposure) requires a multiple dosage of contrast agent, which is not desirable for the patient.
Alternatively to a smaller viewing field or to multiple injections of contrast agent, it is possible after the first adjustment to omit the further adjustments (readjustments) inherently required for high-contrast exposures. However, this leads to a considerable worsening of the image quality.
SUMMARY OF THE INVENTION
An object of the present invention is to provide magnetic resonance imaging apparatus of the type described above that provides high-contrast exposures in a short time, even given an examination of larger body segments.
This object is achieved in accordance with the principles of the present invention in a magnetic resonance imaging apparatus having a magnet and at least one patient receptacle and at least one support plate, as well as a predetermined number of transmit and/or receive coils. At least in two predetermined exposure positions, an exposure respectively takes place using predetermined adjustment parameters. The required adjustment parameters are inventively determined in a preceding adjustment process, and the exposures are executed in a subsequent exposure process.
For example, the exposure parameters can be modified by means of a spatial modification of position (longitudinal displacement, transverse displacement, rotation) of the support plate within the patient receptacle. Alternatively, or in addition, a modification of the adjustment parameters can take place by connection and/or disconnection of the transmit coils and/or the receive coils.
In the inventive magnetic resonance imaging apparatus, the required adjustment parameters are not determined immediately before each individual exposure, as is conventional. Rather, the required adjustment parameters are determined in an adjustment process that precedes the exposure process. Only after the determination of the required adjustment parameters are the exposures carried out, in a separate imaging exposure process.
The adjustment parameters are of course stored at least until the conclusion of the examination. The adjustment parameters thus can be used again, when identical or suitably similar exposure parameters (position of the support plate and configuration of the transmit and/or receive coils) are again reached in the context of the same examination.
In examinations with the inventive apparatus, high-contrast exposures are thus obtained, since it is not necessary to omit an adjustment. Due to the fact that the adjustment is carried out in a separate adjustment process, and the adjustment parameters are stored until the conclusion of the examination, the transmit and receive coils, or their coil elements, can be switched quickly during the examination, so that, in addition, reduced examination times result.
The inventive solution is suitable for a large number of different forms of magnetic resonance imaging apparatuses. Thus, for example, the magnet can be fashioned as a cylindrical magnet (solenoid) or as a horseshoe magnet (C-arm apparatus). Given cylindrically shaped magnets, the patient receptacle is fashioned as a patient tube.
DESCRIPTION OF THE DRAWING
FIG. 1 is a schematic block diagram of a magnetic resonance imaging apparatus constructed and operating in accordance with principles of the present invention.
FIG. 2 schematically illustrates an embodiment of an apparatus in accordance with the invention, wherein the magnet which generates the basic magnetic field is a horseshoe magnet.
FIG. 3 schematically illustrates an embodiment of an apparatus in accordance with the invention, wherein the magnet which generates the basic magnetic field is a cylindrical magnet.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The apparatus in FIG. 1 has a support plate 1 that is arranged in longitudinally placeable fashion inside an examination volume of a magnet. Within the scope of invention, the magnet can for example a cylindrical magnet 18 as shown in FIG. 3 (solenoid) or a horseshoe magnet (C-arm) 19 as shown in FIG. 2 . Given cylindrically shaped magnets, the patient receptacle is fashioned as a patient tube as own in FIG. 3 .
The longitudinal displaceability of the support plate 1 is indicated with a double arrow 2 . Due to the longitudinal displaceability of the support plate 1 , larger body sections of a patient 3 lying on the support plate 1 can be examined.
The nuclear spin resonance apparatus shown in the drawing additionally has a predetermined number of transmit coils 4 and a predetermined number of receive coils 5 .
The transmit coils 4 can be connected, in a desired configuration, to a generator 7 by means of a transmit coil changeover switch 6 . The generator 7 supplies the transmit coils 4 with current via a-transmit amplifier 8 and via a matching element 9 .
The receive coils 5 can be connected, in a desired configuration, to a receiver 11 by means of a receive coil changeover switch 10 . The signals of the connected receive coils 5 are given to the receiver 11 via. a matching element 12 and via a receive amplifier 13 .
The configurations of the transmit coils 4 and the receive coils 5 , defined by the transmit coils changeover switch 6 and by the receive coils changeover switch 10 , are supplied to an adjustment unit 14 as inputs.
As a further input, the position of the support plate 1 , which is determined by a position sensor 15 , is supplied to the adjustment unit 14 .
The adjustment unit 14 processes the inputs that it has received from the transmit coils changeover switch 6 , from the receive coils changeover switch 10 , and from the position sensor 15 , and at its output supplies corresponding control signals to the generator 7 , to the transmit amplifier 8 , to the matching elements 9 and 12 , as well as to the receive amplifier 13 and to the receiver 11 .
In addition, the adjustment unit 14 supplies a control signal to a shim coil system 16 .
The inputs and the control signals (outputs) are stored, as adjustment parameters, in a memory 17 until the conclusion of the examination.
With the embodiment shown in the drawing of the inventive apparatus, larger bodily segments of the patient 3 can be examined. Such examinations are, for example, the tracking of doses of contrast agent over a larger body region, as carried out for example in subtraction angiography or in physiologically controlled imaging.
In the context of the preparation for measurement, which in the case of a peripheral angiography at the leg, includes slice positioning along the vascular tree, several measurements are already made without contrast agent. Due to the homogeneity volume of the magnet being too small, in these measurements the support plate 1 must be displaced, and so must be newly adjusted. The associated adjustment parameters for each position of the support plate 1 are stored in the memory 17 . As additional adjustment parameters, the connected configuration of the transmit coils 4 , as well as the connected configuration of the receive coils 5 , are stored in the memory 17 . In addition, the adjustment parameters include the corresponding control signals for the generator 7 , for the transmit amplifier 8 , for the matching elements 9 and 12 , as well as for the receive amplifier 13 , for the receiver 11 and for the shim coil system 16 .
After the conclusion of the measurement preparation, which includes the determination of the adjustment parameters, the support plate 1 is guided back into the initial position, and the contrast agent is administered. In the imaging measurement that now takes place, each of the positions of the support plate 1 used in the measurement preparation is newly set in succession, and the transmit coils 4 and the receive coils 5 are connected as in the measurement preparation. Subsequently, an imaging measurement (exposure). is immediately carried out with the known adjustment parameters stored in the memory 17 , i.e. without a new adjustment.
In the inventive apparatus, the required adjustment parameters are thus not determined immediately before each individual imaging measurement; rather, the required adjustment parameters are completely determined in a preceding adjustment process, in the context of the measurement preparation. According to the invention, the adjustment process thus precedes the exposure process. Only after the determination of the required adjustment parameters are the exposures (imaging measurement) carried out, in a separate exposure process. In examinations with the inventive apparatus, high-contrast exposures. are thereby obtained, since it is not necessary to omit an adjustment. In addition, due to the fact that the adjustment parameters are stored in a memory 17 until the conclusion of the examination, reduced examination times result. Due to the short examination times, in subtraction angiography the course of the contrast agent can thus be tracked without chronological gaps.
Although modifications and changes may be suggested by those skilled in the art, it is the intention of the inventors to embody within the patent warranted hereon all changes and modifications as reasonably and properly come within the scope of their contribution to the art. | A magnetic resonance imaging apparatus has a magnet with at least one patient receptacle and at least one support plate, as well as a predetermined number of transmit and/or receive coils. In at least two predetermined exposure positions, at least one exposure respectively takes place using predetermined adjustment parameters. High-contrast exposures can be obtained in a short time, by the required adjustment parameters being determined in a preceding adjustment process, and the exposures are carried out in a subsequent exposure process. | big_patent |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to fasteners for albums such as photographic albums and scrapbooks where it is the required to add or replace album pages.
[0003] 2. Description of the Prior Art
[0004] Certain types of photographic albums and scrapbooks are designed for easy expansion by the insertion of additional pages and pages may also be removable from the album as required. Conventially, such an album consists of separate front and rear covers and separate album pages between the covers. The album is held an assembled state by releasable fasteners, each consisting of a male and female screw inserted from the front and the back of the album, the female screw consisting of a screw head and an internally threaded shack and the male screw consisting of a head and an externally threaded shank, which engages within the internally threaded shank of the female screw. The two screws, when assembled, provide a fastening of variable length which can be adjusted within predetermined limits to suit the number of pages within the album. To permit replacement or insertion of pages, one or other of the screws is removed to permit removal of the front or the back cover and possibly some of the album pages at the front or back while the other screw remains in position to retain the remainder of the album pages in alignment. This screw-type fastening system has been in use for many years but is not particularly convenient to use as it can be quite difficult to align the male and female screws while maintaining alignment of the pages particularly when adding album sheets to increase the size of the album.
SUMMARY OF THE INVENTION
[0005] According to the present invention there is provided a releasable fastener for an album comprising front and back covers and removable pages between the covers, the fastener having a pair of strap anchors, one adapted to be attached to the front cover and the other to the back cover, a strap adapted to pass through aligned apertures in the covers and album pages from the strap anchor at the front to the strap anchor at the back, and means for providing a releasable connection between the strap and each of the strap anchors to enable insertion and removal of pages at the front and back of the album, the releasable connection permitting adjustment of the effective length of the strap between the anchors to accommodate a variable thickness of the album.
[0006] In a particularly preferred form of the invention, each strap anchor is in the form of a channel in which the strap is a snap lock to be releasably locked therein against displacement. Preferably the strap is snap-locked into the channel by snapping engagement beneath locking lips at an open side of the channel facing the base of the channel, and the base of the channel and opposing surface of the strap have formations which are engaged to prevent longitudinal displacement of the strap within the channel when its in its engaged position beneath the lips. These inter-engaging formations on the base of the channel and surface of the strap may consist of closely-spaced lateral ribs which are preferably of saw-tooth profile in cross-section, although other types of formations which co-operate to prevent longitudinal displacement of the strap could alternatively be used.
[0007] Preferably there are two or more opposed pairs of locking lips arranged at spaced intervals along the channel. This provides a more positive locking system than the incorporation of a single, long, locking lip extending along each edge of the channel at the open side thereof.
[0008] Preferably the strap enters into the channel via an aperture in the base of the channel and that aperture is bordered by a projection adapted to extend into the adjacent hole in the cover to ensure correct location between the strap anchor and the cover.
[0009] The present invention also provides an album having at least two fasteners as defined above mounted along the spine part of the album, the strap anchors of each fasteners being attached to the respective covers of the album.
[0010] In one practical form, the strap anchors can be adhesively attached to the respective covers, for example by double sided adhesive tape.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Embodiments of the invention will now be described by way of example only with reference to the accompanying drawings in which:
[0012] FIG. 1 is a perspective view showing an album having fasteners in accordance with a preferred embodiment of the invention with the front cover of the album being shown in an open condition to expose the fasteners, each fastener having a pair of identical strap anchors and a strap extending between the anchor;
[0013] FIG. 2 is a plan view of the strap anchor of the fastener;
[0014] FIG. 3 is a transverse cross-section along line A-A of FIG. 2 and showing the pair of strap anchors of the fastener attached to the respective covers of the album, with the strap being omitted;
[0015] FIG. 4 is a cross-section similar to FIG. 3 but along line B-B of FIG. 2 to illustrate the form of the locking lips of the strap anchors;
[0016] FIG. 5 is a perspective view showing the end portion of the strap projecting into the anchor via an aperture in its base and prior to locking of the strap to the anchor;
[0017] FIG. 6 is a perspective view showing the strap when locked to the anchor;
[0018] FIGS. 7 and 8 are cross-sections corresponding to FIGS. 3 and 4 respectively but showing the strap locked within the anchors;
[0019] FIG. 9 is a longitudinal section through the spine of the album to show the pair of strap anchors and the strap locked thereto;
[0020] FIG. 10 is a longitudinal section similar to FIG. 9 and showing a modified embodiment;
[0021] FIG. 11 is a longitudinal section corresponding to FIG. 10 but with the strap omitted; and
[0022] FIG. 12 is a perspective view similar to FIG. 5 but showing the modified embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0023] An album fastener in accordance with a preferred embodiment of the invention comprises a strap 2 of variable length which passes through the album from the front to the back and a pair of identical strap anchors 4 mounted to external surfaces of the front and back covers 6 , 8 . Usually, the album will be assembled using a pair of such fasteners spaced along the spine of the album and that is what is shown in FIG. 1 . The strap 2 is of a semi-rigid plastics material formed on one surface with parallel ribs 10 which extend across the width of the strap 2 . Each strap anchor 4 is in the form of a channel having on its base a corresponding array of transverse ribs 12 to engage with those of the strap 2 when the strap 2 is pressed into the channel to thereby anchor the strap 2 against longitudinal movement within the channel. The exposed end portion of the strap 2 is a snap lock into the channel by being pushed into the channel from its open side facing the base, the strap 2 locking beneath pairs of opposed locking lips 14 at opposite sides of the channel. As shown there are two such pairs of lips 14 .
[0024] The strap 2 enters into the channel through an aperture 16 in the base of the channel adjacent one end and is then folded over and pressed into the channel to snap into engagement beneath the pairs of locking lips 14 which retain the ribs 10 in firm interlocking engagement with the ribs 12 at the base of the channel. The end of the strap 2 will project beyond the channel by a variable distance depending on the thickness of the album and can be easily be grasped to permit the strap to be disengaged from the channel by pulling the strap away from the base of the channel past the lips 14 . In the embodiment described, the snap action to effect the engagement occurs by resilient deflection of the locking lips 14 . In alternative forms however, this may be accompanied by resilient deflection also of the edge portions of the strap or even just the edge portions of the strap may resiliently deflect, with the locking lips being substantially rigid.
[0025] The cross-sectional profile of the strap 2 is designed to facilitate both its insertion into and its removal from the channel when required whilst also ensuring that a secure locking effect is provided. This cross-sectional profile is shown in FIGS. 7 and 8 from which it will be seen that each longitudinal edge of the strap is formed with an inner and outer pair of opposed chamfers 2 a, 2 b. The inner chamfers 2 a facilitate easy insertion into the channel and the outer chamfers 2 b facilitate easy removal from the channel when required, the pairs of locking lips 14 engaging the outer chamfers 2 b as clearly shown in FIG. 8 .
[0026] The strap anchors 4 are moulded in a suitable plastics material and can be attached to the front and back covers of the album by adhesive such as an adhesive tape, with the aperture 16 in the base of the channel being aligned with a hole in the adjacent cover 6 or 8 for passage of the strap 2 therethrough. Preferably, positive alignment is achieved between the aperture 16 and the hole in the adjacent cover by lugs 20 which project from the base of the channel at opposite sides of the aperture 16 to engage in the hole in the adjacent cover as shown in FIG. 9 . The material of the strap 2 is such that although it has sufficient flexibility to enable its projecting end to be bent into the channel and to be deflected past the lips 4 to be retained thereby it also has sufficient rigidity to enable it to be easily inserted through the aligned holes in the covers and album pages therebetween. Insertion of the strap through the holes will, due to the rigidity of the strap, tend to cause the holes in the successive pages to move into required alignment if they are slightly misaligned.
[0027] The opposed end portions of the strap 2 will be attached to the strap anchors 4 on the front and back covers in the manner described, and the strap 2 is of a length to permit adjustment of the album by incorporating additional sets of album pages as required. As a releasable strap anchor 4 provided on the front and back cover, either end of the strap can be released as required.
[0028] The insertion of the straps through the sheets when adding or replacing sheets is significantly easier than insertion of the two-part fastening screws conventionally used and the straps also provide significantly greater versatility in increasing the size of the album as the only controlling factor of the thickness of the album is the length of the strap and that can be made in a length which can accommodate substantial thickness variation.
[0029] Due to the relatively simple nature of the fasteners, they can be produced inexpensively so that their overall cost can be maintained at level comparable with that of the conventional fastening screws. This is quite important because albums of this type do attend to be quite cost-sensitive and despite the improvements obtained in the functionality of the fastener, the album still needs to be available at a price equivalent to that of albums with conventional screw-type fasteners.
[0030] It will be noted from FIG. 1 that the strap anchors 4 are actually applied to what is an inside surface of the cover. In the secured configuration of the fastener, an inner extension flap of the cover shown at 6 a in FIG. 1 is folded over to conceal the two strap anchors and straps. Only a small part of the front cover is actually shown in FIG. 1 and in FIG. 1 the front cover is depicted in its open condition; when closed, the main part of the front cover will be folded inwardly to overlie the extension 6 a. This configuration of front cover, which is repeated also for the back cover, corresponds to that which is used in albums using conventional screw-type fasteners. However, as a consequence of this cover arrangement in which the outer parts of the fastener lie inwardly of the cover when in its closed position, these outer parts do need to be of a low profile so that they do not interfere with closure of the cover. The simple channel form of the described strap anchors with the snap-lock of the straps therein permits the requisite low profile to be achieved as the channel itself is of low profile, and the strap is retained within the depth dimension of the channel by the locking lips without the need for additional locking means projecting outwardly from the channel.
[0031] In a modified embodiment of the invention as shown in FIGS. 10 to 12 the co-operating ribs 10 and 12 on the strap 2 and on the base of the channel 4 are of saw-tooth profile with the upright face of the profile orientated to prevent the strap 2 from being pulled through the channel 4 under the applied loading in the engaged condition of the strap. To ensure the required co-operation between the ribs 10 on the strap and the ribs 12 on the two identical strap anchors of the fastener, the orientation of the saw-tooth profile of the strap ribs is reversed midway along the length of the strap as is clearly shown in FIG. 10 .
[0032] In order to further improve the fixing of the strap in the channel to prevent slipping, additional ribs are also formed on the surface of the adjacent lug 20 and around which the strap passes when entering the aperture 16 . This is shown in FIG. 11 where the additional ribs are designated 12 a.
[0033] In this modified embodiment, in order to further improve the contact area between the ribs 10 and 12 , the ribs 12 have been extended in length to extend across the entire width of the channel 4 except in the zone of the lips 14 where they are of reduced width as a result of tooling considerations associated with the moulding of the lips. This is shown in FIG. 12 .
[0034] The embodiments have been described by way of example only, and modifications are possible within the scope of the invention. | A releasable fastener for an album to permit insertion and removal of pages between the covers. The fastener has a pair of strap anchors each attached to one of the two covers and a strap passing between the anchors via aligned apertures in the covers and album pages. Each strap anchor is in the form of a channel in which the strap is a snap fit so that the strap is releasably locked into the channel and is restrained from longitudinal displacement by inter-engaging formations on the base of the channel and the opposing surface of the strap. | big_patent |
FIELD OF THE INVENTION
The present invention relates to a sulky comprising two wheels, individually fastened, but located along the same rotational axis, to a common frame provided with a driver's seat and shafts leading towards the draught animal.
DESCRIPTION OF RELEVANT ART
Sulkies of this type are used for trotting races and the most important requirements are that they have a lightweight construction, that they are easy-running, and that they are strongly built to endure the specific strain during excercise and competitions.
To obtain constructions of a sufficiently stiff and stable structure and at the same time of lowest possible weight, sulkies so far have been manufactured as welded steel constructions as this has led to the most lightweight construction combined with sufficient strength.
Certainly there have earlier been attempts to build sulkies of aluminium, however such sulkies have got a rather bad reputation due to poor strength qualities.
A conventional sulky has its shafts fastened approximately 10 cms inside of the wheels. This fact leads to a construction well adapted for welded steel pipes, but it is unsuitable when light metals are used because the construction then requires welding. This is probably the reason why earlier attempts using aluminium have failed, as the design then has been similar to the conventional steel constructions requiring a welding process. It is a fact that aluminium and other light metals are difficult to weld, in particular weaknesses in the metal can not be allowed at, or close to, the welding points.
Storing and transportation of conventional sulkies has led to difficulties due to the sulkies having an awkward shape. The manufacturing process has also been expensive and much handwork has been required. Sulkies having even less weight have always been desirable, even if specialists in this field of technique have been convinced that still lighter sulkies could not be manufactured without a corresponding strength reduction.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a new sulky construction having such a design that it may be manufactured of light metal and other lightweight and yet durable materials.
A further object of the present invention is to provide a sulky which may be assembled easily by a user himself, from substantially flat elements requiring only a small space during storage and transportation, said elements being easily dispatched in a flat package.
Still a further object of the present invention is to build up a sulky from inexpensive semi-produced components as casted elements and extruded profiles.
Still a further object of the present invention is to provide a sulky having a stable construction as the shafts as well as the crossbar transfer substantially all the load to the wheel planes only.
Finally it may be mentioned that an object of the present invention is to provide a sulky which easily may be assembled by the user himself by means of ordinary hand tool, and where all the connections become secure, without any play, even if the single components are produced with ordinary manufacturing tolerances.
It should be mentioned that the new sulky construction having shafts fastened to the frame in the planes of the wheels results in the possibility of avoiding the traditional manual manufacturing process including welding of each individual sulky and instead using casting and mass production with corresponding low expenses. By changing to a casting process many of the details required in connection with the wheel suspension, the fastening of the shafts and the crossbar to the frame, may be integrated in the casting process without any additional expenditures. A design of the end frames as stated in connection with the present invention is also required to obtain a structure being well suited for box packaging and do-it-yourself kits based on simple threaded connections.
There is also obtained a weight reduction of approximately 40% for the complete sulky which has a total weight of approximately 18 kg in a ready-to-use state.
Finally it should be mentioned that a sulky according to the present invention in particular is designed to be colored by applying color tapes in all recesses of the profiles, a solution which leads to an inexpensive and individual color display system important for the end users.
BRIEF DESCRIPTION OF THE DRAWINGS
To give a clear understanding of the present invention reference is made to the detailed description of an embodiment given below, and to the accompanying drawings in which:
FIG. 1 illustrates a side view of a sulky according to the present invention,
FIG. 2 illustrates a top view of a sulky according to FIG. 1,
FIG. 3 illustrates a cross section of the crossbar at the connection to an end frame,
FIGS. 4A-4C show an end frame in more detail, and
FIG. 5 shows how a dismantled sulky may be arranged in a flat package.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
In all of the Figures the same reference numbers are used for components having the same function, when appropriate.
In FIG. 1 the sulky 1 is shown in a side view, and it may be seen that both the wheel 2 and the shaft 3 are mounted to the end frame 5.
When FIG. 2, which shows the same sulky as in FIG. 1, but now seen from above, is compared with FIG. 1, where the same reference numbers are used, it may be seen that the driver's seat 4 is arranged centrally on the crossbar 6 which is fastened to the mounting bushings 7 in the end frames 5.
In FIG. 2 the foot treads 8 fastened to the shafts 3 also are shown, and FIG. 2 in particular shows how the end frames are shaped so that the wheel-fastening, shaft-fastening and crossbar-fastening devices all are arranged in the same vertical plane. This is important to obtain a best possible load situation.
As shown in FIGS. 1 and 2 the end frames 5 are arranged symmetrically related to the plane of the wheels 2. This leads to a stable construction of the sulky, but differs from conventional solutions. It may also be understood from FIGS. 1 and 2 that the crossbar 6 is adapted to the mounting bushings 7 and may be fastened thereto. An example of the assembly of those joints is described in more detail below. The details of these joints are important to obtain a stable and rigid frame which may resist the strain occuring during use, and this may be obtained without demanding requirements on the materials in these components or to the manufacturing tolerances of same. According to a preferred embodiment of the present invention the end frames 5, preferably of aluminium or a similar light metal, are casted, e.g. by means of a chill-casting or press-casting process using a light metal, or alternatively by producing the frames of reinforced plastics while the crossbar 6 may be manufactured of extruded aluminium or a similar light metal. Despite the inexpensive process and easily workable materials the geometric design leads to a stable and reliable construction.
The wheels may be fastened to a fork section 9 of the end frames 5 by means of conventional fastening technique, and in a similar manner the shafts 3, which may be made of light metal or plastics reinforced e.g. by carbon fibers, may be fastened to the end frames 5 by means of horizontally arranged fastening bolts 16 and further fastening screws 17 arranged in corresponding holes in the shaft 3. Thereby a fastening of the shaft so as to be adjustable in a longitudinal direction is obtained.
Finally it may be mentioned that the driver's seat 4 is fastened to the crossbar 6 by means of extruded brackets 12 which, if required, may be clamped thereto by means of conventional clamping devices comprising screws or bolts.
The crossbar 6 and the fastening of the same in one of the mounting bushings 7, is shown in more detail at the cross section illustrated in FIG. 3. The crossbar may be designed as an extruded aluminium profile 13 having a closed cross section with internal extending protrusions 14 and 15. In addition there are strengthening elements 18, 19 adapted to fit in with friction between the protrusions 14 and 15. Centrally in these strengthening elements threaded holes 20 and 21 are arranged, and the strengthening elements may be shifted along the aluminum profile 13 to a suitable place so that the threaded holes 20 and 21 coincide with the assembling recesses in the profile 13 and the mounting bushing 7. It may be noted that the strengthening elements 18, 19, arranged on diametrically and opposite faces of the aluminium profile 13, may be combined in one common integrated part as they may be designed, for example as a U-shaped or O-shaped bracket which may be shifted within the track made up of the protrusions 14 and 15. The material of the strengthening elements 18 and 19 may be stainless steel or a similar material having a higher rigidity than the material of the extruded profile 13.
In FIG. 3 one of the mounting bushings 7 is shown together with through screws 22 adapted for fastening the crossbar 6 to the mounting bushing 7. In this connection it is important that the manufacturing tolerances during extruding and casting allow easy introduction of the extruded profile 13 in the mounting bushing 7 with suitable play, however, in such a manner that the materials have a flexibility and deformability adapted so that when the screws 22 are tightened, the extruded profile and mounting bushing 7 will be pulled together by the strengthening elements 18 and 19 respectively, and possibly between oppositely arranged, external strengthening washers 23. After this tightening process the surfaces of the crossbar 6 and the mounting bushing 7 have been somewhat deformed, and therefore an exact adaptation is obtained. It should also be noted that outside the mounting bushing 7 there may also be placed strengthening washers 23, possibly counter bored in the bushing wall so that the material of the bushing 7 and the material of the extruded profile 13 are squeezed between element 19 and a washer of non-corrosive material 23, respectively, and are forcibly pressed towards the rigid bushing 7. Even if the manufacturing tolerances of the extruded profile and the bushing initially left some mutual play, the tightening of the bolt 22 deforms the material so that a close and durable connection is obtained. This connection method ensures a stable and reliable assembly using very simple means.
In FIGS. 4A-4C still more details of the end frame 5 are shown. Here the cross sections of the different parts of the frame also are illustrated. It may in particular be mentioned that the mounting bushing 7 has a cross section that with a certain play is adapted to the external section of the extruded aluminium profile which constitutes the crossbar 6 and is shown in FIG. 3. The loads are evenly distributed due to the symmetrical design of the end frames relative to the wheel planes, and this fact also contributes to a reliable solution in spite of the simple mounting process. The end frame has such a design that it may be cast in a tool comprising only one core and two side walls. The core may be pulled out vertically in a downward direction on the drawing, while all the side elements are bent out to slip the casted element, and the inside and outside of the mounting bushing 7 are formed in contact with the side elements.
The right and the left end frames are preferably casted in the same tool and are therefore quite identical when casted. The tool expenses therefore are reduced and also the storing charges as the number of spare parts also are reduced. In the shown embodiment the external part of the mounting bushing 7 is removed from opposite sides of the end frames before the assembly process, and the resulting holes are covered by caps. However, the invention comprises embodiments where the two end frames are maintained identical also after assembly.
If the qualities of the material and the cross section so allow, the central parts of the crossbar, i.e. the region where the bending moment reaches its maximum value during use, may be reinforced by introducing a square profile between the protrusions 14 and 15.
An important advantage of the present invention is that the complete sulky may be packed into a flat box for storing and transportation to distributers. The user may then buy the sulky as a construction kit and mount the parts himself in a quarter of an hour and then obtain a reliable and professional sulky having a lower total weight but with user qualities equal to those of traditional sulkies. It should also be mentioned that the end frames 5 are identical during production and thus freely may be used on the right or the left side of the sulky. The protruding part of the mounting bushing 7 may then be removed by a simple cutting process before assembly. | Sulky comprising two wheels individually fastened along the same rotational axis, to a common structure provided with a driver's seat (4) and shafts (3) leading towards the draught animal. The sulky (1) consists of a construction kit comprising a plurality of substantially flat elements (2, 3, 4, 5, 6) adapted to be assembled by the end user by means of ordinary hand tools. Two of these parts are end frames (5) adapted for fastening of a wheel (2), a shaft (3), and the crossbar (6) in the same vertical plane. | big_patent |
BACKGROUND OF THE INVENTION
The present invention relates generally to rotating water feeds and more particularly to a ventilation system therefor. The invention is particularly useful in connection with water-cooled generators which preferably comprise coaxial feed and discharge ducts.
Prior to initiating operation of a rotating water feed, special attention must be paid to the elimination of air which may be enclosed in the cooling system in order to avoid undesired local overheating. Such overheating will give rise to several consequences including the formation of steam bubbles which may partly or possibly completely clog the respective cross sections of the flow paths involved. It is important for the proper ventilation of such a cooling system that not only stationary apparatus and auxiliary devices be ventilated, but rotating parts, particularly the water feeds, must also be ventilated. In the case of a rotating machine, it must be noted that the point of lowest pressure is usually at the axis of rotation. Consequently, any air or gas bubbles which remain in the circuit or which have entered through manipulation of the apparatus by operating personnel, will usually accumulate at this point. Despite the fact that these air bubbles will partially block the cross section of the flow paths involved and thereby reduce the efficiency of the cooling system practically no attention is paid to them. For example, in an article entitled "The Development of Water-Cooled Rotors for Large Turbogenerators" in "Technische Mitteilungen AEG Telefunken" 59 (1969), 1, there are described and represented only turbogenerators having no ventilation system.
In "AIEE Transactions" 1950, vol. 69, page 167-170, there are described and presented a few examples of water-cooled turborotors. In a stationary water feed pipe there is arranged a long, thin pipe extending in the axis of rotation. One end of the pipe is located in the branch point of the cooling water connections and the other end extends to the exterior of the machine. This solution, however, has been found to require considerable engineering effort due to the fact that these feeds must involve a great length in most of the cases where they are used.
Accordingly, it is an object of the present invention to provide an arrangement which avoids disadvantages of prior art techniques and which permits automatic removal, or reduction thereof to a tolerable extent, of air or gas bubbles accumulating in rotating pipes such as water feeds of water-cooled generators. It is also an aim of the invention to formulate a structural arrangement which is as simple in design as possible.
SUMMARY OF THE INVENTION
Briefly, the problems discussed above are solved by the present invention in a device of the aforementioned type by providing at least one bypass having at least one inlet and at least one outlet arranged between the feed duct and the discharge duct of the apparatus with the bypass having at least one inlet which opens into the space around the axis of rotation of the apparatus.
The advantages of the invention arise particularly because of the fact that by virtue of the aforementioned arrangement all bubbles will be rapidly and completely removed by utilizing the pressure gradient between the inflow and outflow for automatic operation of the device. Furthermore, the invention provides a ventilation system which is relatively simple in its design and construction.
In accordance with a preferred embodiment of the invention, the bypass is arranged in or on an end face of the feed ducts. This solution is of particular advantage if the branch point is at the end of the feed duct, because this point is usually the last point to which bubbles will be carried by a rotating rotor. If cooling water inlets are distributed over the entire length of a central bore, it is advantageous if the bypass is designed as a radially arranged pipe member with at least one inlet in the space around the axis of rotation. Of course, it is also possible to provide several bypasses in accordance with the structural solution of the present invention.
In accordance with a further embodiment of the invention, the bypass may be designed as a coiled pipe having at least one inlet opening into the space around the axis of rotation. This form of construction affords advantages in that it permits the amount of leakage and bypass to be minimized by simple technical means.
According to a preferred embodiment of the invention, the bypass is structured to include means for increasing the hydrodynamic resistance of flow through the bypass. Such an arrangement enables the achievement of an adequate pressure drop over a short distance with a low resistance to flow and, accordingly, a ventilation system having smaller outer dimensions may be provided.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there are illustrated and described preferred embodiments of the invention.
DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a schematic view partially in section depicting a first embodiment of the invention wherein the bypass means is arranged in the end face of the feed pipe;
FIG. 2 is a schematic view partially in section showing a second embodiment of the invention wherein the bypass is arranged in the end face of the feed pipe;
FIG. 3 depicts a third embodiment of the invention wherein the bypass is designed as a radially arranged pipe;
FIG. 4 shows a fourth embodiment of the invention wherein the bypass in again designed as a radial pipe; and
FIG. 5 depicts a fifth embodiment of the invention wherein the bypass is in the form of a coiled pipe.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, wherein like reference numerals refer to similar parts throughout the various figures thereof, there is depicted in FIG. 1 a ventilation system for a rotating water feed which comprises an axial feed duct 1, defined by an inner pipe 2 having an end face 3. An axial discharge duct 4 is defined by an outer or outlet pipe 5 having an end face 6. The system includes a radial feed duct 7 defined by a radial feed pipe 8 with radial discharge ducts 9 being defined by radial discharge pipes 10. The bypass means of the invention are embodied in a bypass 11 which includes an inlet 11' and an outlet 11". The system defines an axis of rotation designated 19 and the arrows shown in the drawing depict the directions of flow, with the smaller arrows representing the flow which occurs through the bypasses.
In FIG. 2 a second embodiment of the invention is depicted as comprising a bypass member 12 having an inlet 12' and outlets 12".
In FIG. 3 the bypass is shown at 13 with an inlet 13' and with outlets 13". The pipe member forming the bypass 13 is shown at 16 and includes an insert 17 having a spiral groove provided therein in order to form through the bypass a spiral flow path.
In FIG. 4, the bypass means is identified as a bypass 14 having an inlet 14' and outlets 14".
In accordance with FIG. 5, the bypass is designated 15 and it includes an inlet 15' and an outlet 15".
As shown in FIG. 1, the inner pipe 2 forming the axial feed duct 1 is provided with an end face 3. Adjacent the end face 3 there are arranged the radial feed ducts 7 which are formed by the radial feed pipes 8. The bypass 11 is arranged on the axis of rotation 19 with its outlet 11" opening into the axial feed duct 4. As a result of the different pressures occurring in the feed duct 1 and in the discharge duct 4, air bubbles accumulating around the axis of rotation 19 will be transported through the bypass 11 into the discharge duct 4.
FIG. 2 depicts a similar arrangement of feed duct and discharge duct with the bypass 12, however, being designed in the form of a T-pipe. The radially extending portions of the T-pipe of the bypass 12 are formed to be longer than the diameter of the inner pipe 2 and as a result the outlets 12" of the bypass 12 will open into the discharge duct 4 in the direction of flow.
FIG. 3 depicts a bypass 13 which is designed as a radially arranged pipe 16. The inlet opening 13 is again located in the space around the axis of rotation 19 and the outlets 13' open into the discharge duct 4 in the direction of flow. In order to increase the hydrodynamic resistance within the bypass, the pipe 16 includes the insert 17 having a spiral groove 18. This creates a throttling effect and the throttling device shown serves to minimize the amount of bypass flow.
The bypass 14 shown in FIG. 4 involves essentially the same design as the bypass 13 depicted in FIG. 3. However, in FIG. 4 the bypass 14 is arranged at any desired point of the inner pipe 2, this arrangement being suitable for a case where several radial feed ducts 7 open into the axial feed duct 1. In this embodiment it is possible to arrange several bypasses 14 in the inner pipe 2.
The embodiment of FIG. 5 depicts another structural arrangement for the feed duct 1 and the discharge duct 4. In the embodiment of FIG. 5, the bypass 15 is arranged at one end of the outer pipe 5. The bypass is designed in the form of a coiled pipe having its inlet 15' opening once again into the space around the axis of rotation 19. The bypass 15 may, of course, be provided with several inlets 15'. The spiral pipe of the bypass 15 is rather long and thus it will inherently act as a throttle. Of course, the bypass 15 can also be arranged in any cross section of the inner pipe 2 but it may, as a result, reduce the useful flow cross section of the pipe 2.
With the ventilation system in accordance with the present invention as described above, there will result elimination of any air or gas bubbles that may be formed because the inlet openings are provided in the space around the axis of rotation 19 where the arriving air bubbles accumulate because of the existance of a lowest pressure point. Thus, the inlet of the bypass is advantageously arranged and enables bypass flow in a desired manner in order to achieve the advantageous ventilating effects of the invention.
While specific embodiments of the invention have been show and described in detail to illustrate the application of the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles. | A ventilation system for rotating water feeds particularly useful in water-cooled generators is equipped with bypass means arranged to extend between coaxial feed duct means and discharge duct means defining a centrally located axis of rotation. The bypass means includes at least one inlet which is located to open in the space around the axis of rotation with outlet means of the bypass means opening into the discharge duct means to vent air or gas bubbles. | big_patent |
BACKGROUND OF THE INVENTION
[0001] The invention relates to a steering column for a motor vehicle, which comprises a jacket unit supporting a steering shaft rotatably about its longitudinal axis and a retaining part, which the jacket unit is secured non displaceably up to a limit value of a force acting onto the jacket unit parallel to the longitudinal axis of the steering shaft in the direction toward the front of the motor vehicle. If the limit value is exceeded, the jacket unit is displaceable parallel to the longitudinal axis in the direction toward the motor vehicle front. The jacket unit is connected with the retaining part, for one, across an energy absorption connection, which comprises at least one bending wire or strip that, upon a displacement of the jacket unit with respect to the retaining part parallel to the longitudinal direction toward the motor vehicle front, is deformed, and is connected, for another, across a break-away connection which, up to the limit value of the force, is closed and blocks a displacement of the jacket unit with respect to the retaining part and which is released if the limit value of the force is exceeded. The invention further relates to a method for the production of such a steering column.
[0002] Steering columns for motor vehicles are most often implemented such that they are adjustable so that the position of the steering wheel can be adapted to the seating position of the driver. Such adjustable steering columns are known in various embodiment forms. Apart from adjustable steering columns which are only adjustable in the length or height or inclination direction, steering columns are also known which are adjustable in the length as well as also the height or inclination direction.
[0003] As a safety measure in the event of a vehicle crash, it is known and conventional to realize in steering columns for motor vehicles the steering shaft together with a jacket unit, rotatably supporting the steering shaft, in a section adjoining the steering wheel-side end such that it is displaceable in the longitudinal direction of the steering column (=parallel to the longitudinal axis of the steering shaft) with the absorption of energy. A conventional implementation form provides for this purpose that a bracket unit, with respect to which in the opened state of the clamping mechanism the jacket unit is displaceable for setting the position of the steering column, is so connected with a mounting part attached on the vehicle chassis that the jacket unit with the absorption of energy is dislocatable with respect to the mounting part. Such a construction is shown, for example, in U.S. Pat. No. 5,517,877 A.
[0004] DE 28 21 707 A1 discloses a non-adjustable steering column in which the jacket tube rotatably supporting the steering shaft includes bilaterally projecting fins which had been connected on the chassis by securement blocks and bolts penetrating therethrough. In the event of a crash, the fins can become detached from the securement blocks, whereby a dislocation of the jacket tube is enabled. Between the securement blocks and the fins, U-shaped bending strips are herein provided on which deformation work is carried out during the dislocation of the jacket tube. The bending strips are enclosed in chambers of the fins and are in contact on opposing side walls of the chambers such that the rolling radius of the particular bending strip during its deformation is limited and predetermined.
[0005] An adjustable steering column comprising a jacket unit rotatably supporting the steering shaft and a bracket unit, with respect to which the jacket unit in the opened state of a securement device is displaceable for setting the position of the steering column at least in the longitudinal direction of the steering column, is disclosed in EP 0 598 857 B1. In the event of a crash, the jacket unit can be dislocated with respect to the bracket unit or with respect to a clamp bolt of the securement device in the longitudinal direction of the steering column. For the energy absorption, bending strips or bending wires are provided that are entrained with the jacket unit and placed about the clamp bolt, which strips or wires are deformed. One disadvantage of this solution is that the possible displacement path or the characteristic of the energy absorption in this device depends on the particular positioning length of the steering column.
[0006] Further, U.S. Pat. No. 5,961,146 A describes a steering column which in normal operation is only adjustable in the height direction. In a manner similar to that described above, a bending wire is provided curved in the shape of a U about the clamp bolt of the securement device, which in the event of a crash is entrained by the jacket unit dislocating with respect to the clamp bolt in the longitudinal direction of the steering column, whereby bending work is performed.
[0007] In the steering column disclosed in WO 2007/048153 A2, in the closed state of the securement device a retaining part is prevented by a securement part of the securement device from being displaced with respect to this securement part referred to the direction parallel to the steering shaft. The jacket unit can become dislocated in the longitudinal direction of the steering column with respect to the retaining part with the absorption of energy. For the energy absorption, a bolt is disposed on the retaining part which projects into an elongated hole of an energy absorption part disposed on the jacket unit and which, during its shift in the event of a crash, widens this elongated hole. To attain defined energy absorption, the material properties of the energy absorption part in the proximity of the elongated hole must be precisely defined such that they are reproducible.
[0008] Similar steering columns are also disclosed in EP 0 849 141 A1 and EP 1 464 560 A2. The retaining parts are guided by guide parts in the manner of a carriage such that they are displaceable in the longitudinal direction of the steering column. They are held under frictional closure with respect to the guide parts or plastically deform them with the consumption of energy. In the case of a frictionally engaged mounting, the clamping force of the securement device must be taken into account when considering the magnitude of the energy absorption. In a plastic deformation of the guide parts, their material properties must be implemented in a precisely defined reproducible manner.
[0009] A steering column of the above type is disclosed in DE 10 2008 034 807 B3. The retaining part is connected with the jacket unit, for one, across a bending wire or strip and, for another, across a pin forming a break-away connection between the retaining part and the jacket unit. If, in the event of a crash, a force, acting onto the steering wheel-side end of the steering shaft parallel to the longitudinal axis of the steering shaft in the direction towards the vehicle front, exceeds a limit value, the pin is shorn off and the break-away connection is consequently released. The jacket unit can then become dislocated with respect to the retaining part parallel to the longitudinal axis of the steering shaft in the direction toward the vehicle front, wherein the bending wire or strip is deformed and thereby energy is absorbed. The retaining part is herein hindered from being displaced in the direction parallel to the longitudinal axis of the steering shaft through its engagement with its securement part of the securement device. In the opened state of the securement device, the securement part is raised from the retaining part and the jacket unit, together with the retaining part, can be displaced parallel to the longitudinal axis of the steering shaft in order to carry out a length positioning of the steering column. Further, in the opened state of the securement device, a height or inclination adjustment of the steering column is feasible.
[0010] One disadvantage in this prior known steering column includes that during the opening of the break-away connection a force peak (=break-away peak) occurs, e.g. the limit value of the force acting parallel to the longitudinal axis of the steering shaft, starting at which the break-away connection is released and an energy absorbing displacement of the jacket unit with respect to the retaining part sets in, is relatively high. After the break-away connection has been released, the force counteracting a displacement of the jacket unit with respect to the retaining part is less.
SUMMARY OF THE INVENTION
[0011] The invention addresses the problem of at least decreasing this force peak (=break-away peak), and to do so in a simple and cost-effective yet functionally advantageous implementation.
[0012] This is attained according to the invention through a steering column with the features described below or, respectively, through a method for the production of a steering column with the features described below. Advantageous further developments are described in the dependent claims.
[0013] In the steering column of the invention an elastic prestress is exerted onto the at least one bending wire or strip. The jacket unit is thereby prestressed with respect to the retaining part in the displacement direction parallel to the longitudinal axis of the steering shaft in the direction toward the vehicle front. This prestress acts on the break-away connection between the jacket unit and the retaining part. The force required in the event of a crash to release the break-away connection is thereby decreased since the elastic reset force of the at least one bending wire or strip is added to the force exerted, in particular through the secondary collision of the driver with the steering wheel, parallel to the longitudinal axis of the steering shaft in the direction toward the vehicle front. The force peak during the breaking away of the jacket unit from the retaining part (=break-away peak) can thereby be decreased or entirely avoided. Nevertheless, in normal driving operation (thus when no vehicle crash occurs), an adequately stable connection is provided between the retaining part and the jacket unit, through which a shaking between the jacket unit and the retaining part and vibrations through intrinsic resonances can be avoided, and this can be achieved with a very simple implementation.
[0014] The steering column is preferably implemented such that it is adjustable in length. An openable and closable securement device is herein provided, in the opened state of which the jacket unit is displaceable with respect to a bracket unit supporting the jacket unit parallel to the longitudinal axis of the steering shaft and which, in its closed state, applies a securement force for the securement of the jacket unit with respect to the bracket unit against a displacement parallel to the longitudinal axis of the steering shaft. In the mounted state of the steering column the bracket unit is herein firmly secured on the vehicle, at least in normal operation, thus without a crash having occurred, e.g. up to a maximum force acting in the direction of the longitudinal axis of the steering shaft.
[0015] An advantageous embodiment of the invention provides that the retaining part is formed by a part of the securement device. The retaining part in the closed state of the securement device is herein in engagement with a securement part which is secured in position with respect to the bracket unit such that it is nondisplaceable in the direction of the longitudinal axis of the steering shaft. Through this engagement between the securement part and the retaining part, at least a portion of the securement force is applied securing, in the closed state of the securement device, the jacket unit against a displacement parallel to the longitudinal axis of the steering shaft. In the opened state of the securement device, the retaining part and the securement part are out of engagement. However, the energy absorption device for enabling the energy absorbing dislocation of the jacket unit in the event of a crash is integrated into the securement device. In this embodiment of the invention, the vehicle-stationary mounting of the bracket unit can be provided. A further energy absorbing dislocateability between the bracket unit and a mounting part, displaceably supporting this bracket unit parallel to the longitudinal axis of the steering shaft and mounted stationarily on the vehicle, can consequently be omitted.
[0016] Since in this embodiment of the invention the securement part, referred to in the direction of the longitudinal axis of the steering shaft, is nondisplaceable with respect to the bracket unit. The retaining part, during the displacement of the jacket unit with respect to the bracket unit, in the opened state of the securement device moves simultaneously with the jacket unit. The securement part and the retaining part thus come in different length settings of the steering column in different positions into mutual contact when the securement device is closed. In the closed state of the securement device, the displacement of the retaining part with respect to the securement part (in the direction parallel to the longitudinal axis of the steering shaft) is counteracted by securement elements cooperating, preferably under form closure, advantageously through cooperating toothings. The securement of the jacket unit in the closed state of the securement device against a displacement in the length displacement direction, consequently, takes place at least also via the cooperation of the securement part with the retaining part. Additionally, for example, securement elements acting under frictional closure can be provided for the securement of the jacket unit against a displacement in the length displacement direction in the closed state of the securement device.
[0017] The height or inclination of the steering column is especially preferably also settable in the opened state of the securement device.
[0018] In the event of a crash, after the break-away connection has been released during the dislocation of the jacket unit with respect to the retaining part (which is held nondisplaceably with respect to the securement unit in the direction parallel to the longitudinal axis of the steering shaft), at least a section of the at least one bending wire or strip is entrained by the jacket unit. The deformation of the bending wire or strip takes place by the bending of the bending wire or strip or comprises at least one such. The bending wire or strip preferably comprises two legs connected via a recurvature, wherein the two legs form an angle in particular in the range of 150° to 220°, preferably an angle of 180°, such that a U-shaped development of the bending wire or strip results.
[0019] An advantageous development provides that the bending wire or strip is at least partially enclosed in a housing which preferably is formed by a portion of the jacket unit. For this purpose, a rail U-shaped in cross section is secured in position on a jacket tube rotatably supporting the steering shaft. A development of the housing or a portion thereof on the, respectively of the, bracket unit is also conceivable and feasible.
[0020] The break-away connection between the retaining part and the jacket unit can be formed, for example, by a pin connecting these two parts, which, in the event of a crash, is sheared off if the limit value of the force acting upon the steering shaft and thereover onto the jacket unit parallel to the longitudinal axis of the steering shaft in the direction toward the vehicle front is exceeded. Other types of form closure connections, which, in the event of a crash, are released through material reforming, material shearing or fracture, are also conceivable and feasible. A break-away connection can, for example, also be attained through a frictional closure connection which, if the limit value of the force is exceeded, enables a dislocation of the jacket unit with respect to the retaining part and only acts over a small first segment of the displacement path. Consequently, as a break-away connection any connection between the jacket unit and the retaining part should be considered which, after a displacement over a short displacement path between the jacket and the retaining part (parallel to the longitudinal axis), which is preferably less than two centimeters, counteracts a further displacement between the jacket unit and the retaining part with no force or only a significantly lower than initial force, preferably less than one tenth of the initial force.
[0021] Accordingly, a solder connection or welded connection or adhesive connection is suitable as the break-away connection if it is laid out such that it is released when the desired force is exceeded.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Further advantages and details of the invention will be explained in the following in conjunction with the enclosed drawings, in which:
[0023] FIG. 1 is a side view of a steering column according to a first embodiment of the invention;
[0024] FIG. 2 is a section view along line BB of FIG. 1 ;
[0025] FIG. 3 is a section view along line AA of FIG. 1 ;
[0026] FIG. 4 is an oblique view of the steering column of FIG. 1 ;
[0027] FIG. 5 is an oblique view of the jacket unit, of the section of the steering shaft rotatably supported thereby and the retaining part;
[0028] FIG. 6 is a section view corresponding to line CC of FIG. 2 , wherein, however, are omitted the bracket unit, the intermediate unit and the securement device, apart from the securement part in engagement with the retaining part (shown in section);
[0029] FIG. 7 a is a section view along line EE of FIG. 2 during the assembly of the steering column, the parts listed in FIG. 6 being again omitted;
[0030] FIG. 7 b is a section view analogous to FIG. 7 a in the completed state of the steering column;
[0031] FIG. 8 is a section view analogous to FIGS. 7 a and 7 b after a vehicle crash;
[0032] FIG. 9 is an exploded view depicting the jacket unit, of the retaining part and the connection parts connecting these according to a second embodiment of the invention;
[0033] FIG. 10 is an oblique view onto the back side, not visible in FIG. 9 , of the retaining part;
[0034] FIG. 11 a is a view onto the back side, not visible in FIG. 9 , of the rail of the jacket unit attached on the jacket tube in the state connected with the retaining part, in a state during the assembly of the steering column;
[0035] FIG. 11 b is a view corresponding to FIG. 11 a after a further assembly step;
[0036] FIG. 11 c is a view corresponding to FIG. 11 a in the completed state of the steering column.
DETAILED DESCRIPTION OF THE INVENTION
[0037] A first embodiment of the invention is depicted in FIGS. 1 to 8 . The steering column comprises a jacket unit 2 which bearing supports a steering shaft 1 rotatably about the longitudinal axis 4 of the steering shaft 1 , which comprises a steering wheel-side end 3 serving for the connection of a steering wheel, not shown in the Figures. The jacket unit 2 is connected with a retaining part 5 across a break-away connection and energy absorption connection, which will be more precisely described later. Up to a limit value of a force acting between the jacket unit and the retaining part 5 parallel to the longitudinal axis 4 , the retaining part 5 is connected with the jacket unit 2 such that it is nondisplaceable relative to the direction of the longitudinal axis 4 . The limit value can herein be identical or different for the two directions parallel to the longitudinal axis 4 and be set during the construction of the system.
[0038] A force F (or the corresponding force component parallel to the longitudinal axis 4 ), exerted in the event of a crash through the secondary collision of the driver onto the jacket unit 2 , is directed toward the vehicle front, as is illustrated in FIG. 1 , and accordingly is absorbed through a counter-force on the bracket unit 6 .
[0039] A bracket unit 6 supporting the jacket unit 2 in the operating state of the steering column is rigidly connected with the chassis of the motor vehicle. In the opened state of a securement device 7 the steering column can be adjusted in length and in height or inclination. The jacket unit 2 is herein displaceable with respect to the bracket unit 6 parallel to the longitudinal axis 4 (=length adjustment direction 8 ) and into a height or inclination adjustment direction 9 , at right angles thereto, with respect to the bracket unit 6 . In the closed state of the securement device 7 a securement force, for the securement of the jacket unit 2 relative to a displacement taking place parallel to the longitudinal axis 4 with respect to the bracket unit 6 , is applied, wherein the securement force is, at least relative to a displacement parallel to the longitudinal axis 4 in the direction toward the vehicle front, higher than the limit value of the force up to which the jacket unit 2 is held nondisplaceably with respect to the retaining part 5 . Further, by the securement device 7 , a securement force for the securement of the jacket unit 2 is applied against a displacement with respect to the bracket unit 6 in the height or inclination adjustment direction 9 .
[0040] In the depicted embodiment, the jacket unit 2 is located between side jaws 10 , 11 of the bracket unit 6 . Between the side jaws 10 , 11 of the bracket unit 6 and the jacket unit 2 are located side flanks 12 , 13 of an intermediate unit 14 which encompasses the jacket unit 2 at least over a large portion of its circumference. In the opened state of the securement device 7 the intermediate unit 14 is displaceable with respect to the bracket unit 6 in the height or inclination adjustment direction 9 . For this purpose, it is swivellable about a swivel axis 15 with respect to the bracket unit 6 . The intermediate unit 14 is connected with the bracket unit 6 nondisplaceably, relative to the direction of the longitudinal axis 4 , for example (also) via the development of this swivel axis 15 . The jacket unit 2 in the opened state of the securement device 7 is displaceable with respect to the intermediate unit 14 , displaceably guiding the jacket unit 2 , parallel to the longitudinal axis 4 and, in the closed state of the securement device 7 , is held nondisplaceably with respect to the intermediate unit 14 through the securement force applied by the securement device 7 in the direction of the longitudinal axis 4 .
[0041] The securement device 7 comprises a clamp bolt 16 extending at right angles to the longitudinal axis 4 which penetrates through openings 17 , 18 (cf. FIG. 2 ) in the side jaws 10 , 11 , which are implemented as elongated holes extending in the direction of the height or inclination adjustment 9 and in which the clamp bolt 16 shifts during the height or inclination adjustment of the steering column. The clamp bolt 16 is held by the margins of these openings 17 , 18 nondisplaceably, relative to the direction of the longitudinal axis 4 , with respect to the bracket unit 6 . The clamp bolt 16 , further, penetrates openings in the side flanks 12 , 13 of the intermediate unit 11 whose diameter, apart from a sliding clearance, correspond to that of the clamp bolt 16 .
[0042] On the clamp bolt 16 securement parts 19 , 20 are disposed on both sides of the side jaws 10 , 11 of bracket unit 6 , through which parts penetrates the clamp bolt 16 through openings and which are axially displaceable in the direction of the axis of the clamp bolt 16 . The one securement part 19 includes a section in which it is penetrated by clamp bolt 16 and a section 22 connected therewith across a connection section 21 , in which section 22 the part 19 cooperates, as will be described below, with the retaining part 5 . The securement part 20 and the securement part 19 , in the proximity of its section penetrated by clamp bolt 16 , in the closed state of the securement device are pressed onto the side jaws 10 , 11 of the bracket unit 6 in order to secure in position the adjustment of the steering column in the height or inclination adjustment direction. This securement in position can take place through frictional closure. Elements cooperating under form closure, for example toothings, can also be provided.
[0043] For tightening the securement parts 19 , 20 with the side jaws 10 , 11 and securement part 19 with the retaining part 5 , the securement device 7 can be implemented in the conventional manner. For example, a clamping lever 23 serving for opening and closing the securement device 7 is connected with a cam disk 24 , which it entrains upon a turning about the axis of the clamp bolt 16 and which cooperates with a link disk. The link disk is here implemented as integral with the securement part 19 , but a separate link disk could also be provided. Configurations with rolling bodies or other implementations of clamping mechanisms are also applicable.
[0044] The section 22 of the securement part 19 penetrates an opening in the side jaw 10 (the side jaw 10 could also terminate above the section 22 of the securement part 19 ) and an opening in side flank 12 of the intermediate unit 14 . In the closed state of the securement device, section 22 is pressed with a toothing 25 disposed thereon onto a toothing 26 of the retaining part 5 . Depending on the length positioning of the steering column, the toothings 25 , 26 come into mutual contact in different positions.
[0045] Section 22 of securement part 19 , which in its entirety is located on one side of clamp bolt 16 , is held nondisplaceably against a shift with respect to the bracket unit 6 in a direction parallel to the longitudinal axis 4 by the margins of the penetrated opening in side jaw 10 and/or by the margins of the penetrated opening in side flank 12 of the intermediate unit 14 .
[0046] Through the cooperating toothings 25 , 26 the retaining part 5 in the closed state of the securement device 7 is secured in position against a displacement with respect to securement part 19 in the direction of the longitudinal axis 4 . If, during the closing of the securement device 7 , these two toothings come into mutual contact in a tooth-on-tooth position, at least after a minimal initial shift (which is less than the tooth spacing of the toothing) a further shifting of the retaining part 5 with respect to the securement part 19 is blocked.
[0047] Other form-closure connections between the securement part 19 and the retaining part 5 are also feasible, for example via bolts engaging into holes.
[0048] In the opened state of the securement device 7 the securement part 19 is retracted from the retaining part 5 and these two parts are brought out of engagement, wherein the jacket unit 2 , together with the retaining part 5 , is displaceable in the length adjustment direction 8 .
[0049] Apart from the type of implementation of the connection between the jacket unit 2 and the retaining part 5 , which will be described more precisely in the following, the elements of the steering column described above can be implemented in a manner known from prior art, in particular according to DE 10 2008 034 807 B3 cited in the introduction to the description.
[0050] The retaining part 5 is guided displaceably with respect to the jacket unit 2 parallel to the longitudinal axis 4 and is connected with the jacket unit 2 , for one, across a break-away connection and, for another, across an energy absorption connection. The break-away connection can be realized, for example, via a shear bolt 27 . In the depicted embodiment example, the shear bolt 27 is set, on the one hand, into an opening 28 in the retaining part 5 , for example into an opening 29 (cf. FIG. 3 ). The jacket unit 2 comprises in this embodiment example a jacket tube 30 and a rail 31 with U-shaped cross section rigidly connected therewith, for example by welding, and extending in the direction of the longitudinal axis 4 . The opening 29 is here implemented in the rail 31 .
[0051] For developing the energy absorption connection serves a bending wire or strip 32 , which is connected, on the one hand, with the retaining part 5 , on the other hand, with the jacket unit 2 . In the depicted embodiment, the bending wire or strip 32 is developed in the shape of a U, wherein the one U-leg is connected with the retaining part 5 and the other U-leg with the jacket unit 2 , specifically with the rail 31 . The connections of the U-legs are each such that they act in both directions parallel to the longitudinal axis 4 , preferably under form closure. The two U-legs preferably extend, at least substantially, parallel to the longitudinal axis 4 .
[0052] To connect the one U-leg with the retaining part 5 , this part can comprise, for example, a pin 33 projecting through a slot 34 extending parallel to the longitudinal axis 4 in the rail 31 and engaging into an eyelet 35 in the bending wire or strip 32 . The connection of the other U-leg with the jacket unit 2 can be developed, for example, by placing the end of the U-leg in contact on a stop 36 of the rail and through extensions 37 of the rail engaging into indentations in the U-leg.
[0053] In the embodiment, the bending wire or strip 32 is enclosed in an inner chamber of a housing formed by the rail 31 and the section of the jacket tube 30 terminating it. In this housing, the bending of the bending wire or strip 32 takes place freely, thus not about a pin.
[0054] During assembly of the steering column, the bending wire or strip is elastically deformed, e.g. it is deformed with respect to a neutral position which it assumes without external forces, wherein it exerts a reset force in the direction of the neutral position. For this purpose the bending wire or strip 32 is comprised of an adequately elastic material, for example a spring-elastic steel. Through this elastic prestress of the bending wire or strip 32 , the jacket unit 2 is prestressed with respect to the retaining part 5 relative to a displacement parallel to the longitudinal axis 4 in the direction toward the motor vehicle front.
[0055] The implementation of this prestress is depicted schematically in FIGS. 7 a and 7 b . In FIG. 7 a , the bending wire or strip has its non-prestressed neutral position which it assumes without action of an external force, wherein it is connected with the jacket unit 2 and the retaining part 5 . As indicated in FIG. 7 a , in this production step the opening 28 in the retaining part 5 (shown above the longitudinal axis 4 ) and the opening 29 in rail 31 (shown beneath the longitudinal axis 4 ) are offset with respect to one another in the direction of the longitudinal axis 4 .
[0056] The retaining part 5 is subsequently displaced (toward the left in FIG. 7 b ) with respect to the jacket unit 2 parallel to the longitudinal axis 4 by a distance d in the direction toward the vehicle front, wherein the pin 33 elastically prestresses the bending wire or strip. In this prestressed position according to FIG. 7 b , the opening 28 in the retaining part 5 (shown above the longitudinal axis 4 ) and the opening 29 in the rail 31 (shown beneath the longitudinal axis 4 ) overlap one another and the shear bolt 27 is now inserted (illustrated by the arrow in FIG. 7 b ) whereby the break-way connection is implemented.
[0057] If in the event of a crash at least a force acting parallel to the longitudinal axis 4 in the direction toward the vehicle front is exerted onto the steering wheel-side end 3 of the steering shaft 1 , in particular through the secondary collision of the driver, this force is transmitted from the steering shaft 1 onto the jacket unit 2 and is added to the prestress force exerted by bending wire or strip 32 , and, if the sum of these forces exceeds a limit value, the break-away connection is released through the shearing-off or breaking-off of the shear bolt 27 . Therewith, the dislocation of the jacket unit 2 parallel to the longitudinal axis 4 in the direction toward the vehicle front can commence, thus into the direction away from the steering wheel-side end 3 of the steering shaft 1 , wherein the jacket unit 2 is dislocated with respect to the retaining part firmly secured by the securement part 19 . After a first partial segment of this displacement path, which is preferably smaller than one tenth of the entire displacement path between the jacket unit 2 and the retaining part 5 , the bending wire or strip 32 starts to counteract the further dislocation with a force as soon as the neutral position of the bending wire or strip 32 has been reached or has been exceeded. During the further dislocation, the bending wire or strip 32 is deformed with the absorption of energy, wherein this deformation, after a further segment of the displacement path which is preferably smaller than a tenth of the entire displacement path, transitions into a plastic deformation. The state after the vehicle crash in shown in FIG. 8 .
[0058] For the layout of the energy absorption, in particular with respect to magnitude and course, the cross section and the cross section course of the bending strip 32 can be dimensioned appropriately. Further, essential for the energy absorption behavior are the strength of the connection between the rail 31 with the jacket unit 2 and the metal sheet thickness of the rail 31 as well as the course of the width of the slot 34 in the rail 31 . Additionally, the radius of curvature of the rail 31 in the direction of the tabs, with which the rail 31 is secured on the jacket unit 2 , is a parameter affecting the determination of the energy absorption behavior.
[0059] The securement device can hold the jacket unit 2 , even additionally to the mounting through the engagement between the securement part 19 and the retaining part 5 , for example under frictional closure, against a displacement parallel to the longitudinal axis 4 , for example, so that during the closing of the securement device 7 , the intermediate unit 14 is tightened against the jacket unit 2 . Such an additional holding force exerted by the securement device 7 directly onto the jacket unit 2 is taken into account in the limit value of that force above which, in the event of a crash, a dislocation of the jacket unit 2 with respect to the bracket unit 6 occurs.
[0060] A second embodiment form of the invention is depicted in FIGS. 9 to 11 . The distinction from the previously described embodiment lies in the energy absorption connection between the jacket unit 2 and the retaining part 5 . The break-away connection is implemented by a shear bolt 27 as in the previously described embodiments.
[0061] The one U-leg of the bending wire or strip 32 is secured with the rail 31 against a displacement in both directions parallel to the longitudinal axis 4 through prominences 38 of the bending wire or strip 32 , which engage into a cutout 39 of the rail 31 . However, only one prominence 38 engaging into a cutout 39 could also be provided. The other U-leg includes at the end side a bend-off with a thickened end 40 . This is retained in an interspace between projections 41 , 42 disposed on the retaining part 5 , which penetrate the slot 34 in the rail 31 . This leg of the bending wire or strip is thereby held nondisplaceably in both directions of the longitudinal axis 4 with respect to the retaining part 5 .
[0062] During the assembly, the unstressed bending wire or strip 32 is inserted and connected with both of its legs with the retaining part 5 and the rail 31 . The retaining part 5 is subsequently first displaced parallel to the longitudinal axis 4 by a distance c in the direction away from the vehicle front, thus in the direction toward the steering wheel-side end 3 of the steering shaft 1 (toward the left in FIG. 11 b ), see the position evident in FIG. 11 b in comparison to FIG. 11 a . During this displacement, a plastic deformation of the bending wire or strip 32 occurs. Manufacturing tolerances can thereby be compensated such that in this manner a defined starting state is attained. Subsequently, there results a displacement of the retaining part 5 by a distance d parallel to the longitudinal axis 4 in the direction toward the vehicle front, thus away from the steering wheel-side end 3 of the steering shaft 1 (toward the right in FIG. 11 c ), wherein the bending wire or strip 32 is elastically prestressed, see FIG. 11 c in comparison to FIG. 11 b . In this position, the openings 28 , 29 in the retaining part 5 and in the rail 31 overlap and the shear bolt 27 is inserted, which is illustrated by the arrow in FIG. 11 c.
[0063] The described plastic deformation before the elastic prestress could also be carried out in the case of the first described embodiment.
[0064] In addition to the already listed advantages, the solution according to the invention has an advantageous effect on the noise behavior of the steering column. Through the prestress a dampening effect is achieved.
[0065] The break-away connection between the retaining part 5 and the jacket unit 2 could also be implemented in a manner other than in the first and second embodiment, e.g., a nose tapering the slot 34 could also be provided, over which the pin 33 or the projection 41 would need to drive for the release of the break-away connection. The break-away connection secures the jacket unit 2 with respect to the retaining part 5 and in normal operation thus prevents shaking of the jacket unit 4 with respect to the retaining part 5 .
[0066] An implementation with more than one bending wire or strip 32 is also conceivable and feasible. One of the bending wires or strips or more than one of the bending wires or strips could here be elastically prestressed in the described manner. For example, on both sides of the jacket unit 2 retaining parts 5 could be provided which cooperate with securement parts, for example in the manner described in connection with the securement part 19 . Both retaining parts 5 could herein be connected with the jacket unit 5 across an energy absorption connection comprising at least one bending wire or strip 32 and across a break-away connection. A connection of only one of the retaining parts with the jacket unit through an energy absorption connection or through a break-away connection is also feasible.
[0067] Although the implementation with side jaws 10 , 11 of the bracket unit 6 disposed on both sides of the jacket unit 2 is preferred, against which, in the closed state of the securement device 7 , parts of the securement device are tightened, implementations are also conceivable and feasible in which the bracket unit comprises only one side jaw located on one side of the jacket unit 2 .
[0068] A steering column according to the invention could, for example, also be implemented such that it is adjustable only in the length adjustment direction 8 . In such an embodiment, the intermediate unit 14 could be omitted and the opening 17 , 18 through which penetrates clamp bolt 16 could be implemented in the shape of a circle in each side jaw 10 , 11 of the bracket unit.
[0069] A steering column adjustable in the length adjustment direction 8 as well as also in the height or inclination adjustment direction 9 can also be implemented without an intermediate unit 14 . Herein in the jacket unit 2 elongated holes could be provided, penetrated by clamp bolt 16 , which extend in the length adjustment direction 8 of the steering column. For example, for this purpose on the jacket tube 30 at least one upwardly or downwardly projecting part could be disposed in which these elongated holes are disposed.
[0070] The jacket unit 2 can also, at least over a portion of its longitudinal extent, be implemented such that it is circumferentially open.
[0071] If, through a frictional closure connection a sufficiently high desired securement force in the direction of the length adjustment 8 between the retaining part 5 and a securement part 19 is attainable, a frictional closure engagement between these two parts could also be provided. To increase the securement force could herein also be provided additional cooperating friction faces, for example in the form of cooperating lamellae. Such cooperating lamellae could also be provided for the additional securement in the height or inclination adjustment direction 9 .
[0072] As is known, the bracket unit 6 could also be connected, dislocatably in the direction parallel to the longitudinal axis 4 in the event of a crash under energy absorption, with a mounting part connected stationarily on the vehicle.
[0073] For the case that an energy absorption is required in a direction that does not coincide with the longitudinal direction of the steering column (=direction of the longitudinal axis 4 ), the device according to the invention can also be oriented in this direction. The prestress would in that case be introduced in this direction into the one or the several bending wires or strips 32 . According to the illustrated examples, the rail 31 would be accordingly secured on the jacket unit oriented in this direction.
LEGENDS TO THE REFERENCE NUMBERS
[0000]
1 Steering shaft
2 Jacket unit
3 Steering wheel-side end
4 Longitudinal axis
5 Retaining part
6 Bracket unit
7 Securement device
8 Length adjustment direction
9 Height or inclination adjustment direction
10 Side jaw
11 Side jaw
12 Side flank
13 Side flank
14 Intermediate unit
15 Swivel axis
16 Clamp bolt
17 Opening
18 Opening
19 Securement part
20 Securement part
21 Connection section
22 Section
23 Clamping lever
24 Cam disk
25 Toothing
26 Toothing
27 Shear bolt
28 Opening
29 Opening
30 Jacket tube
31 Rail
32 Bending wire or strip
33 Pin
34 Slot
35 Eyelet
36 Stop
37 Extension
38 Prominence
39 Cutout
40 End
41 Projection
42 Projection | A steering column for a motor vehicle includes a casing unit, which rotatably supports a steering shaft about the longitudinal axis thereof, and a retaining part. The casing unit is held in a fixed manner relative to said retaining part up to a threshold value of a force acting on the casing unit in a parallel manner to the longitudinal axis of the steering shaft in the direction of the front of the vehicle. When the threshold value is exceeded, the casing unit is movably held in a parallel manner to the longitudinal axis in the direction of the front of the vehicle. The casing unit is connected to the retaining part via an energy-absorbing connection, which a bending wire or strip that is deformed when the casing unit is moved relative to the retaining part parallel to the longitudinal axis in the direction of the front of the vehicle, and via a breakaway connection closed up to a threshold value of the force and blocks a movement of the casing unit relative to the retaining part and which opens when the threshold value of the force is exceeded. | big_patent |
The present application is a continuation-in-part of application Ser. No. 172,806, filed Mar. 28, 1988, now abandoned, which is a continuation-in-part of application Ser. No. 031,752, filed Mar. 30, 1987, now abandoned, for which all equitable rights are claimed.
BACKGROUND OF THE INVENTION
The present invention relates to a process for mounting glass panels in curved window bays of motor vehicles and the like, and in particular, to a method for utilizing flat, uncurved glass panels to form curved windows in such vehicles.
In modern automobiles, the use of highly curved pre-contoured and pre-stressed front windshields is very apparent to all observers. Not so apparent, is the fact that the rear window and the side quarter windows are also curved, although to an extent which is considerably less than that of the front windshield. Further, the curvature is generally only in a single and longitudinal direction of the glass. however, at present, the process of installing even these slightly curved panels is basically identical to the process by which the highly complexedly curved front windshield is installed. Specifically, even the slightly curved windows are pre-contoured by expensive, annealing and tempering processes, employing expensive molds, and are then set in the conforming recessed flange of window bays.
The conventional process has many disadvantages, amongst which is the fact that the glass panel is distorted during the tempering and contouring process and is caused to become less flexible and more brittle. In addition, problems arise in packaging such glass for transportation and storage. While, glass that is pre-contoured does, however, become stronger relative to perpendicular shock and strain, it does become significantly weaker at the same time in other respects, in that it does not thereafter readily flex. Consequently, in a vehicular accident, it can easily dislodge from the bay in which it is set, "pop" out of the vehicle, and easily shatter. On the other hand, untreated flat glass, or even chemically treated flat glass which has not been pre-contoured or tempered, is less rigid and less brittle thereby being more flexible and bendable so that in the event of a vehicular accident, it is less likely to shatter and more likely to absorb any shock and strain applied to it.
Additionally, when pre-contoured glass breaks during an accident, the vehicular body is less able to resist crushing because the window is without the structural support furnished by the glass normally filling the same. Thus, during an accident, the roof of the car is apt to collapse upon the occupants during a turn-over where there is no glass in the window opening than when the glass remains intact therein.
Most importantly, the cost of a comparably sized flat glass panel is at least one eighth to one tenth the cost of a pre-treated, pre-contoured glass. Coupling such cost with the added cost for packaging and shipment of pre-contoured glass panels, the difference in eventual expense to the consumer is considerable.
It is the object of the present invention to provide an improved process, overcoming the disadvantages enumerated above. In particular, it is an object of the present invention, to provide a process wherein flat uncontoured glass can be applied in the vehicle window, wherein it is made to assume in situ a curved shape.
It is a further object of the present invention to provide a process for economically and inexpensively installing glass windows of a curved nature in vehicle windows and the like.
More particularly, in the within inventive method in which a flat glass is flexed and used as a closure for a curved window opening and, as will be described in greater detail herein, a phenomenon that has been organized and underlies the present invention is that flexing of the flat glass producing an urgency therein to return from its flexed to its flat shape. This urgency is used to advantage to enable the application of adhesive sealant which, when cured, permanently holds the glass in place within the cooperating window opening. More specifically, in the within inventive method, one of the steps consists of, after placing the flexed glass in place against reveal molding, applying a continuous bead of adhesive sealant into the space between the edge of the glass window panel and the window opening by the flexing of the window panel outwardly against said reveal molding.
The foregoing objects and advantages, together with numerous advantages are set forth in the following disclosure.
SUMMARY OF THE INVENTION
According to the present invention, the method for installing a window panel in a curved opening of a vehicle, comprises the steps of placing a flat uncontoured glass panel within the curved window bay, securing along the edge of the bay bounding the curved window opening, a holding means sufficient to engage and maintain the flat glass in the curved window opening, said glass panel being flexed from its initial flat configuration into the conforming curvature of the window, and thereafter applying a weather sealant and adhesive compound in situ along the confronting edges of the window panel and allowing said adhesive to cure until the panel becomes fixed permanently in the window opening in its conforming curvature.
The fastening means comprises a plurality of resilient clips uniformly spaced about the perimeter of the window bay and a reveal molding cooperatively secured to the clips, so that the reveal molding is provided with a resilient bias, pressing on the outer surface of the glass panel, pushing the glass into conforming engagement with the bay of the window opening.
Full details of the present invention are set forth in the following description of the preferred method, as illustrated in the accompanying drawings.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partially exploded perspective view of the rear window of an automobile, showing the application of a conventionally pre-curved window thereto, according to the prior art;
FIG. 2 is a top view of the glass panel of the prior art taken in the direction of 2--2 of FIG. 1;
FIG. 3 is a view similar to that of FIG. 1 showing the application of the present method to the installation of a flat glass panel in an automobile window;
FIG. 4 is a top view of the flat glass panel employed in the method shown in FIG. 3; and
FIG. 5 is a sectional view, greatly enlarged, showing the completed window installation.
DESCRIPTION OF THE INVENTION
The present invention is illustrated and described herein for simplicity, with reference only to the installation of glass in the rear window of an automobile. It will be understood, however, that the same principles apply to installations in other vehicle windows, or the like.
As seen in FIG. 1, the rear window bay, generally depicted by the numeral 10, of automobile 12 is defined by the roof flange into a rectalinear frame 14 having an L-shaped cross-section. A panel of curved glass 16, as seen in FIG. 2 is inserted, into the frame 14 and a metal reveal molding 18 is secured thereabout. In this arrangement, the glass panel 16, is pre-contoured in the manner illustrated in FIG. 2 by being bowed an amount 16A in the longitudinal direction, to have a concave/convex configuration. Similarly, the reveal molding 18 is bowed accordingly. As seen in FIG. 1, the pre-contouring of both the glass panel 16 and the reveal molding 18, enables the installation of the two quite easily. The reveal molding 18, is held from falling out by a plurality of clips 20 uniformly spaced about the periphery of the window opening or bay. The glass 16 is held by continuous bead 22 of curable adhesive material applied along the perimeter of the glass panel 16 forming a bond and weatherproof seal between the panel 16 and the frame 14. The reveal molding encloses the peripheral edge of the glass panel, but it does not co-act with the clips and/or with the glass to hold the glass, let alone effect any flexing of the glass.
In comparison to the prior art, the present invention as illustrated in FIGS. 3 to 5, provides for the installation of inexpensive flat glass and the in situ flexing of the glass to conform to a curved window bay. The vehicle 12 and its window opening or bay 10, are of course, identical with that shown in FIG. 1 since such is solely within the purview of the automobile designer and would be prohibitive to change. Nevertheless, in accordance with the invention, a glass panel 24, rather than being pre-contoured, is supplied flat, uncontoured and untempered, but sized and shaped overall so as to readily fit the opening bay 10 of the window. The flat glass panel 24 is placed within the bay 10 being flexed slightly by hand to conform to the contour of the bay and placed into engagement with perimeter fastening means generally depicted by the numeral 26 provided to hold the glass panel 24 to least temporarily in place.
As seen in FIG. 5, the fastening means 26 is formed of a combination of individual resilient clips 28 and a reveal molding 30. The individual clips 28 are arranged uniformly about the perimeter of the bay 10 and are secured firmly in place by an anchoring screw 32, tapped into the back wall of the frame 14. Each clip 28 has an outwardly extending leaf portion 34 on which is integrally formed a detent 36.
The reveal molding 30 is uniform through its perimeter, and as seen in cross-section (FIG. 5) is provided with a triangular shaped head 38 having a flange 40 adapted to engage the detent 36 on the clip. The triangular shaped head 38 is adapted to snap on to the leaf part 34 of each clip 28 so as to be held firmly between the back wall of the frame 14 and detent 36. Each of the clips 28 simultaneously urge the reveal molding 30, in cross-section, in clockwise arc, (arrow A) inwardly and downwardly into the window bay 10 whereby the lower end 42 of the molding 30 engages and presses onto the face of the glass panel 24. Under this collective urging, the lower end 42 or inner edge of the reveal molding acts as a securing element effecting and maintaining flexure of the glass panel continuously about its perimeter. The lower end 42 of the molding 30 is bent to provide an inturned edge on which a continuous band of weather stripping 44 is secured, the weather stripping extending into engagement with the leaf portion 34 of clip 28.
At this point it is significant to note that the glass panel 24 is not yet permanently mounted in its position in the window opening 10 and relative to the reveal molding 30. The permanent mounting thereof is achieved using the same prior art adhesive sealant 22 that is inserted in the compartment between the panel 16 and the frame 14. However, it is one of the features of the within inventive method that there will be adequate clearance for the placement of the adhesive sealant 22 behind the peripheral edge of the flexed glass panel 24 because the flexing produces an urgency therein which forces this peripheral edge outwardly and thus into contact with the reveal molding clip portions 30, and thus providing an opening for inserting the adhesive sealant mass 22 in the glass-holding position as illustrated in FIG. 5.
Within the frame 14 and after insertion of the adhesive sealant 22, the within inventive method contemplates the placement of a continuously extending dam 46 of elastic material placed so that it lodges along the inner wall of the frame 14 adjacent the periphery of the window bay 10 in contact with the inner surface of the glass panel 24. The dam 46 acts as a closure for the continuous bead 22 of adhesive sealant of material which was previously placed within frame 14 in an amount sufficient to engage with, and bond with, the confronting inner surface and peripheral edge of the glass panel 24. The flat uncontoured glass 24 is held in place by engagement with the fastener means 26 until the adhesive 22 cures and bonds, thereby setting the glass panel permanently in place. The action of the biased reveal molding and the adhesive, maintains the glass panel 24 permanently curved and in place.
Conventional tempered or untempered flat glass panels of rear vehicle window size, e.g., 18×60 inches and 1/8 inch thick, are easily flexed in situ and can be employed here.
Preferably the reveal molding 30 is also supplied and used as a straight member being unbent and uncontoured prior to installation in the window. It is, however, sufficiently flexible to be held by the clips 28 spaced along the flange bounding the window bay 10.
The curable adhesive is preferably polysulfide, having suitable fillers and solvents added thereto so that when cured, this material exhibits the property of rubber in that it is capable of accepting sheer stress without cracking or corroding in changeable climate or other atmospheric conditions. Such curable adhesives are well known, commercially available and widely used, so that further description here is unnecessary.
Various changes and modifications have been suggested and others will be obvious to those skilled in the art. Thus, it is intended that the present disclosure be taken as illustrative only and not limiting of the scope of the present invention. | A glass window installed in a curved window opening of a vehicle by placing along the edge bounding said curved window opening, window-engaging fastening means. A window pane sized to fit into said window opening is flexed from an initial flat configuration into a conforming curvature of said window, while establishing engagement between said flexed window pane and said window-engaging fastening means, to temporarily hold said window pane in said conforming curvature. A weather-sealing adhesive compound placed along the confronting edges of said window pane and window opening to complete a weatherproof installation of said window pane. | big_patent |
This application claims the benefit of U.S. Provisional Application No. 60/281,919 filed Apr. 5, 2001.
FIELD OF THE INVENTION
The present invention relates to methods and apparatus for removing a gas from a liquid, and more particularly relates, in one embodiment, to methods and apparatus for separating oxygen from water, particularly on an offshore hydrocarbon recovery platform.
BACKGROUND OF THE INVENTION
In many industries, including oil, paper and pulp, textile, electricity generating and food processing, there is an ever-present problem of handling water contaminated with various substances. In particular, water is often used to aid in the production of oil and gas on offshore platforms. This water is usually pumped into a formation in order to be able to pump oil out. The water pumped into the formation is typically available water, and is sea water in the case of offshore platforms. Seawater, like all naturally available water, contains small concentrations of oxygen, typically on the order of 6-10 ppm. The pumps, pipes and other structures through which the sea water is passed prior to injection into a subterranean formation typically are iron or copper alloys. The corrosion of these metals is catalyzed by the small quantities of oxygen present in the sea water, and thus it is desirable to remove as much of this oxygen as possible prior to transporting the water through the pipes, pumps, and other apparatus prior to formation injection. Because it is especially difficult to replace and repair equipment in offshore drilling operations due to much of the equipment being underwater and relatively inaccessible, it is particularly important to minimize corrosion of the equipment as much as possible.
Current practices for removing oxygen from water include stripping towers employing natural gas, and/or using a vacuum to reduce the boiling pressure of the water. Such prior art techniques usually cannot remove the oxygen to trace levels and thus chemical scavengers such as sulfites are used to remove oxygen further in a separate step. Unfortunately, floating offshore platforms typically are not tolerant of excessive vessel heights that are required of conventional stripping towers for oxygen removal. It would thus be advantageous to discover a method and apparatus for removing oxygen from water in an efficient manner involving a shorter physical profile, and particularly in an apparatus that is adapted for use on an offshore floating platform.
Apparatus for ingesting and mixing gas into a liquid body are known, such as those of U.S. Pat. No. 3,993,563, that includes a tank, a rotatable impeller fixed to a vertical drive shaft, and a vertically-extending conduit which surrounds the drive shaft and which extends to location in the liquid above the impeller to serve as a channel of communication between a source of gas and the impeller.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide an apparatus for displacing a gas from a liquid, which apparatus is particularly suited to be used on floating offshore hydrocarbon recovery platforms.
It is another object of the present invention to provide a mechanical, cylindrical gas scavenger machine having a reduced height as compared with a stripping tower with a sump for chemical scavenger treatment to reduce oxygen content in a fluid such as water.
In carrying out these and other objects of the invention, there is provided, in one form, an apparatus for removing a gas from a liquid, where the apparatus includes a vessel for receiving a flow of liquid having a first gas contained therein, and where the vessel has a plurality of partitions sequentially dividing the vessel into at least a first gasification chamber and a second gasification chamber. Each adjacent chamber is in fluid or liquid communication with one another. Each chamber also has a vapor space, and there is no communication between the vapor spaces of adjacent chambers. The vessel also includes an inlet to introduce the flow of liquid into the gasification chambers. There is present a mechanism for ingesting and mixing a second gas into the liquid of each gasification chamber for creating a turbulent area and for displacing at least a portion of the first gas to the vapor space of each chamber. Finally, there is a vent in each chamber of the vessel for removing gas plus a liquid outlet from the outlet chamber.
BRIEF DESCRIPTION OF THE DRAWINGS
The single FIGURE is a schematic, cross-sectional illustration of one embodiment of the mechanical oxygen scavenger device of the invention.
It will be appreciated that the FIGURE is a schematic illustration that is not to scale or proportion to further illustrate the important parts of the invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will now be described, by way of example, and not limitation, with the influent or treated liquid being water that contains oxygen that is replaced by the inert gas nitrogen. However, it will be appreciated that the invention is not limited to this particular liquid or to these particular gases. It is expected that the methods and apparatus will find utility with liquids other than water and gases other than oxygen and nitrogen. It is to be understood that the present invention has utility in numerous applications in which it is desirable to replace one gas from a liquid with another, and that the replaced gas, the liquid containing the new gas, or both may be the desired product of the process.
Referring now to the FIGURE, the system 10 of the apparatus of a preferred embodiment of the invention includes a vessel 12 for receiving a flow of liquid 14 having a first gas mixed therewith, where the vessel 12 in a preferred embodiment has a continuous cylindrical sidewall and is capable of withstanding substantial internal pressures. Vessel 12 is divided into a feed box or inlet chamber 16 , at least a first gasification chamber 18 , a second gasification chamber 20 , and an outlet or discharge chamber 22 , where each adjacent chamber can fluidly communicate with one another, that is, that a fluid in one chamber may and should flow into an adjacent chamber. The outlet chamber 22 may optionally function in secondary oxygen chemical scavenging. Outlet chamber 22 may optionally provide an injection booster pump plus level control as typically used in the process, though these latter functions will not influence the removal of the first gas by the second gas. It should be apparent that the flow of the liquid is from the inlet 30 to the outlet 34 . The particular vessel 12 shown in the FIGURE also contains third and fourth gasification chambers 24 and 26 , respectively. The chambers 16 , 18 , 20 , 24 , 26 , and 22 and are divided by a plurality of generally vertical partitions 42 , 44 , 46 , 48 , and 50 respectively. Partitions 42 may, in one non-limiting embodiment, may extend from the top and bottom of the interior of vessel 12 and have an aperture 52 in the middle thereof to permit the fluid to flow into first gasification chamber 18 . Partitions 44 , 46 , 48 , and 50 extend from the interior top of vessel 12 downward, and are spaced from the interior bottom of vessel 12 to allow fluid communication between the adjacent chambers. The flow of liquid 14 follows liquid transport path 36 through the vessel 12 , although within each chamber, some back flow 40 of liquid 14 into the impeller or rotor 38 will occur during agitation and mixing.
Each gasification chamber 18 , 20 , 24 and 26 may be, but is not required to be, essentially identical in design. Only gasification chamber 20 is shown in detail, and it may be assumed for the purposes of this non-limiting explanation that the other gasification chambers are the same. Each gasification chamber 18 , 20 , 24 , and 26 will have a vapor space 54 above the liquid 14 level, but the vapor spaces of the adjacent chambers are not in communication with one another. Most preferably, there is an absence of communication between the vapor space of any gasification chamber with the vapor space of any other gasification chamber. The lengths of partitions 42 , 44 , 46 , 48 , and 50 are calculated to minimize the effect of pressure differential due to difference in flow rates under each respective partition.
Inlet chamber 16 has an inlet 30 to introduce the flow of liquid 14 to the inlet chamber 16 . Each gasification chamber 18 , 20 , 24 and 26 has at least one mechanism 32 for ingesting and mixing gas into the liquid of each respective gasification chamber 18 , 20 , 24 , and 26 for creating a turbulent area where the second gas displaces the first gas to an upper portion or vapor space 54 of the vessel 12 for each respective chamber 18 , 20 , 24 , and 26 . Gas ingesting and mixing mechanisms 32 , in one non-limiting embodiment, may be submerged rotor mechanisms, and in another non-limiting embodiment are typically dispersed air flotation mechanisms, and are preferably the devices of U.S. Pat. No. 3,993,563, incorporated by reference herein, although it will be appreciated that other devices, including but not limited to, simple aerators, may be used. Mechanisms 32 may also be depurators. Mechanisms 32 , such as described in U.S. Pat. No. 3,993,563, may each include one or more external gas circulation ports 56 to transfer gas into the rotor assembly of mechanism 32 from the vapor space 54 in the upper portion of vessel 12 . Generally, mechanisms 32 create a vortex that draws air from vapor space 54 into the liquid. It is not the intent of the apparatus or method to re-circulate gas from the vapor space when removing the first dissolved gas with a second ingested gas. The second gas will be introduced via an external gas connection 58 which will be attached to a source external to vessel 12 .
The gas ingesting and mixing mechanisms 32 obtain their source of second gas, optionally an inert gas such as nitrogen, from gas connect or inlet 58 in each gasification chamber 18 , 20 , 24 , and 26 . Each gas inlet 58 will be located within the standpipe diameter of each aeration chamber 18 , 20 , 24 , and 26 . Vertical standpipe partition 56 of generally cylindrical configuration is present between impeller 38 and vapor space 54 . Communication between gas connect 58 and the gas ingesting and mixing mechanisms 32 is by means of conduits not shown in the FIGURE. Second gas is not injected into the vapor space 54 in each chamber 18 , 20 , 24 and 26 . Instead, the first gas displaced from the fluid collects in the vapor spaces 54 and is removed from vessel 12 by tank breather 60 , located in each chamber 18 , 20 , 24 , and 26 . It is permissible for a portion of second gas that passes through the liquid in each chamber to be vented through tank breather 60 . It may be desirable or necessary for the outlet from the vapor space 54 in each gasification chamber to be equipped with a one-way gas valve to prevent backflow of the displaced first gas. That is, it is not a requirement of the apparatus or method that all of the second gas injected into vessel 12 be carried out in fluid 14 as it exits through outlet 34 .
The second gas, e.g. nitrogen, is induced into the liquid, e.g. water, to be de-aerated by the mechanisms 32 . This process also provides a means of controlling the partial pressure parameters, and allows the second gas to displace the first gas, e.g. oxygen, thus scavenging oxygen from the water. The first gas is physically not chemically displaced from the fluid by the second gas. Henry's Law of partial pressures requires that the first gas be displaced as the second gas is introduced. With each succeeding chamber, more of the first gas is replaced at each point. The number of stages or chambers is not critical, but should be sufficient in number to reduce the concentration of the first gas in the fluid to the desired level. It is expected that several gasification chambers would be necessary to remove sufficient amounts of the first gas in most cases. It should be apparent that the method of the invention is a continuous process. It is desirable to predict and control the amount of second gas ingestion based on rotor submergence of 32 and speed of rotor or impeller 38 to achieve the desired removal level for the first gas, and the rate at which the second gas is ingested.
Gas ingesting and mixing mechanisms 32 may also include water draft tubes (not shown) to transfer water into the rotor assemblies of mechanisms 32 exclusively from the bottom of the vessel 12 . Inclusion of the water draft tube facilitates capacity variations within the same geometry because all water that enters the rotor assembly is directed to the rotor suction from the bottom of vessel 12 , reducing fluid by-pass and short circuiting of the fluid around the turbulent areas. The treated effluent flows out of vessel 12 via outlet 34 which may have a valve therein (not shown). Flow through the vessel is maintained via pumps or innate system pressure (not shown).
There may also be present in vessel 12 an internal float displacer liquid level controller 62 (or other suitable liquid level controller) to regulate the rate at which fluid 14 enters vessel 12 . The apparatus 10 may also have a control mechanism, such as a programmable logic controller (PLC) (not shown) for controlling the liquid level in the gasification chambers 18 , 20 , 24 , 26 by obtaining level information from level transmitters (not shown) and regulating flow through level control valves (LCVs, not shown) which is in fluid communication with the liquid in each chamber. The exact natures of the level transmitters, PLC and LCVs are not critical and may be conventional in the art; however, their implementation in the oxygen scavenging apparatus of the invention is expected to be inventive.
In one embodiment of the invention, the oxygen scavenging apparatus 10 has a dual-cell design, that is, only two gasification cells, 18 and 20 , but more may be used as illustrated in the FIGURE. An optional chemical scavenging feed unit (not shown), which is a standard feed unit for dispensing a metered amount of a first gas scavenging chemical, such as a sulfite, into fluid 14 , to additionally treat the fluid for achieving optimum separation of the first gas from the water can be provided. This optional chemical treating may occur in outlet chamber 22 . However, it may be appreciated that such an additional chemical scavenger treatment may not be necessary.
Although not shown, valves may be provided for blowdown of sludge that collects in the bottom of vessel 12 . A drain 64 for cleaning out vessel 12 may also be provided. Also not shown are optional gauges to monitor the pressure of the effluent and the flow of gas.
In the method of the invention, a continuous flow of liquid 14 having a first gas mixed or dissolved therewith is introduced into inlet chamber 16 through inlet 30 . Fluid 14 flows past partition 42 into the gasification chambers 18 , 20 , 24 , and 26 sequentially via liquid transport path 36 . In each chamber a flow of second gas is introduced into the liquid 14 by gas ingesting and mixing mechanisms 32 , creating a turbulent area in the entirety of chambers 18 , 20 , 24 , and 26 , and allowing the second gas to physically displace the first gas. The first gas is forced out of the liquid 14 as bubbles to the upper portion of vessel 12 where it collects in the respective vapor space 54 of each chamber. First gas is collected and removed through tank breather 60 .
Fluid 14 , progressively more free of first gas, next underflows each partition 44 , 46 , 48 , and 50 in turn flows through liquid outlet 34 . It will be appreciated that it is not possible to predict with accuracy how much of the first gas may be removed from the liquid 14 since such removal depends upon a number of complex, interrelated factors including, but not limited to, the nature of the gases, the nature of the liquid, the concentration of the first gas in the liquid, the ability of the liquid to absorb the second gas, the temperature of the liquid, the pressures within the vessel 12 , and the like. Nevertheless, in order to give some indication of the levels of reduction that might be achieved, it is expected that oxygen in sea water may be displaced by nitrogen from initial levels of about 6-10 ppm to about 0.5-1.0 ppm, in a non-limiting embodiment.
The rate at which scavenged liquid 14 may removed from vessel 12 may be regulated by a valve or valves (not shown) in response to software program commands or other control mechanism.
To summarize, advantages of the invention include, but are not necessarily limited to a decreased vessel height requirements as compared with separate stripping towers and reduced capital costs. These advantages are achieved through an oxygen scavenging machine (e.g. depurator) using physical methods to displace a first undesired gas with a second, inert gas. Floating production system operations (FPSO) installations utilizing water floods could also use the apparatus of the invention. In most expected methods of using the apparatus of the invention, it is not expected that the liquid only contain very small quantities of the second gas. It may be that the liquid contains appreciable amounts of the second gas, and this is acceptable.
In the foregoing specification, the invention has been described with reference to specific embodiments thereof, and has been demonstrated as effective in providing a device and apparatus for removing or stripping an undesired gas from a liquid. However, it will be evident that various modifications and changes can be made thereto without departing from the broader spirit or scope of the invention as set forth in the appended claims. Accordingly, the specification is to be regarded in an illustrative rather than a restrictive sense. For example, the distances between the partitions and the volumes of the various chambers may be changed or optimized from that illustrated and described, and even though they were not specifically identified or tried in a particular apparatus, would be anticipated to be within the scope of this invention. Similarly, gas ingestion and mixing mechanisms, and level transmitting and control devices different from those illustrated and described herein would be expected to find utility and be encompassed by the appended claims. | It has been discovered that a mechanical device may be used to effectively displace a first undesired gas from within a liquid with a second desired or at least inert gas. The device is a vessel that receives the liquid containing the first gas and passes the liquid through a series of gasification chambers. Each gasification chamber has at least one mechanism that ingests and mixes a second gas into the liquid thereby physically displacing at least a portion of the first gas into a vapor space at the top of each gasification chamber from which it is subsequently removed. There is an absence of communication between the vapor spaces of adjacent chambers. The ingesting and mixing mechanisms may be a dispersed air flotation mechanism, and may be a conventional depurator. The liquid now containing the second gas and very little or none of the first gas is removed from the vessel for use. | big_patent |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims foreign priority benefits under 35 U.S.C. §119(a)-(d) to European patent application number EP 10007915.1, filed Jul. 29, 2010 which is incorporated by reference in its entirety.
TECHNICAL FIELD
[0002] This disclosure relates to a packaging machine comprising a plurality of work stations which are operable in synchronism with one another and which define a production direction of the packaging machine, said work stations being arranged in succession e.g. in said production direction, with each work station including at least one movable tool member.
BACKGROUND
[0003] The packaging machine may be a deep-drawing packaging machine. In such packaging machines the packaging material passes through a plurality of work stations in succession so as to subject the packaging material and/or the products to be packed to various working steps in temporal succession. In so doing, for example, packaging troughs are deep-drawn in the moving material at a forming station. Alternatively, prefabricated trays are removed from a destacker. The deep-drawn packaging troughs (or, alternatively, the pre-fabricated trays) are then filled with a product, the packages are evacuated and/or flushed with gas, they are sealed with a top foil or closed by means of a slip lid, and, if necessary, the packages are also separated from one another, checked and/or sorted out. These working steps take place in work stations which normally each include at least one movable tool member. The movable tool members of the individual work stations have to be synchronized with one another when the packaging machine is operated in an intermittent mode as well as in a continuous mode so as to guarantee a smooth operation of the packaging machine.
[0004] EP 0 515 661 B1 discloses a packaging machine of the type in question in the form of a deep-drawing machine. This machine is provided with a forming station for forming packaging troughs in a bottom foil as well as with a filling station and a sealing station. For each of the work stations a mechanism is provided for converting the rotation of an electric motor into a lifting movement of a tool member of the respective work station, such as, for example, the forming tool of the forming station, or the chamber part of the sealing station. In order to cause both sides of the respective tool to move upwards or downwards parallel to one another, a belt couples the movement of a plurality of shafts which extend transversely to the production direction of the packaging machine and the rotary movement of which is converted into a lifting movement of the respective tool member. This conventional packaging machine is, however, disadvantageous insofar as respective separate drives must be used for the different work stations. In particular, it is difficult to synchronize the movements of the tools of the different work stations with one another.
SUMMARY
[0005] The system of the present disclosure provides an improved packaging machine with a simpler, more compact design. This is achieved by a packaging machine having one or more the features described below.
[0006] The packaging machine of the present disclosure is provided with a rotationally driven shaft arranged in the production direction of said packaging machine. The shaft and each of the movable tool members of various work stations have provided between them at least one transfer mechanism for converting the rotational movement of the shaft into the movement required to operate the respective tool member. Since this shaft drives the tool members of a plurality of work stations, the movements of these tool members are automatically synchronized with one another through the movement of the shaft. This synchronization is effected mechanically and is therefore independent of potential errors of an electronic synchronization. The shaft arranged in the production direction of the packaging machine only requires comparatively little installation space so that the packaging machine can have a very compact structural design.
[0007] According to one embodiment, the transfer mechanism comprises an arrangement of toggle levers and/or a cam mechanism for converting the movement of the shaft into the movement of the respective tool member. In this way, the transfer mechanism is rendered robust and independent of high wear components, such as a belt. In addition, the comparatively high forces required for lifting the tool members can be transferred effectively by an arrangement of toggle levers or a cam mechanism.
[0008] When the transfer mechanism is provided with a cam mechanism, the latter preferably includes a wear-reducing element so as to reduce the wear-dependent load on the transfer mechanism and thus on the shaft. The wear-reducing element may, for example, consist of one or a plurality of wheels rolling along a cam profile. It is also contemplated to provide, as a wear-reducing element, the surface of a component of the cam mechanism with a material having a lower coefficient of friction and/or to execute a suitable surface treatment so as to reduce the friction on this surface.
[0009] The shaft may be driven in a continuous 360° rotation. This would have the advantage that a transmission between the shaft and the shaft driving unit, e.g. an electric motor or in particular a servomotor, could have a comparatively simple structural design. However, where alternating tool-member lifting movements are desired to be caused by the shaft, it may be more advantageous when the shaft is driven alternately in different directions of rotation.
[0010] Work stations of the packaging machine whose tool members are driven by means of the shaft so as to execute a lifting movement may e.g. be a forming station, a sealing station and/or a separating or cutting station. The packaging machine may also comprise a plurality of work stations of one of the above-mentioned types.
[0011] According to one variant of the packaging machine according to the present disclosure, at least two work stations of the packaging machine are arranged on different vertical levels. This would have the advantage that the work stations can be arranged more closely to one another in the horizontal direction, so that the structural design of the packaging machine can be rendered even more compact. In particular, it would be possible that two work stations are even arranged one above the other and/or that a packaging material is deflected by 180° between two work stations so as to be transferred from a first conveying plane to a second conveying plane.
[0012] It should be noted that relative positional or orientative terms such as “vertical”, “horizontal”, “upper”, “lower”, “forward”, and “backward”, are used herein to describe locations and direction based upon an assumption that the machine is installed for operation where the longitudinal axis of the packaging machine and the drive shaft extend in a horizontal direction, and the packaging material moves “forward” in the production direction of the machine. Thus, it will be understood that, regardless of the orientation of the machine, “horizontal” will always be understood to be substantially parallel to the longitudinal axis of the longitudinal axis of the machine, as well as to the longitudinal axis of the drive shaft, and forward will always refer to movement in the production direction, regardless of the actual physical orientation of a particular machine.
[0013] It will be expedient to provide a frame for supporting the shaft. This frame should be adequate to stabilize the shaft and prevent the generation of vibrations in the packaging machine, which may otherwise impair the precision of the packaging process.
[0014] According to an advantageous variant of the disclosure, a tool member on a work station is adapted to be displaced in the production direction of the packaging machine, said tool member being movable by means of the shaft. The packaging process can thus easily be adapted to varying conditions, for example, to the use of a different type of packaging materials or to the production of a different type of package shapes. In this respect, it will be particularly advantageous when the displacement or adjustment can be executed without the necessity of acting on the shaft and/or the transfer mechanism. For example, it would be imaginable that the cam mechanism acts on a horizontal cam profile and that the lifting movement of the operated tool member is independent of the actual point of application of the cam mechanism on the cam profile.
[0015] Depending on the type of work station whose tool member is to be operated, it may be advantageous to provide two transfer mechanisms for converting the movement of the shaft into the movement of a tool member of the work station. This will be particularly advantageous e.g. in the case of a cross cutter for a packaging foil. The use of two transfer mechanisms for lifting the cutting tool of the cross separator on either side of the packaging foil web prevents in this case canting of the cutting tool and guarantees thus a reliable, continuous cut through the web of packaging foil.
[0016] When two transfer mechanisms are provided, these transfer mechanisms are preferably arranged symmetrically to the central shaft, laterally displaced relative to said shaft (i.e., the transfer mechanisms are provided on different sides of the shaft, each at the same distance from said shaft) to insure that the driving forces will be transferred uniformly from the shaft to the two transfer mechanisms.
[0017] In the following description, two advantageous embodiments of the present disclosure will be explained in more detail with reference to the below drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a perspective view of a detail of a first embodiment of a packaging machine according to the present disclosure, in the open condition of the tools;
[0019] FIG. 2 is a perspective view of the packaging machine shown in FIG. 1 , in the closed condition of the tools;
[0020] FIG. 3 is an enlarged representation of the forming station of the packaging machine shown in FIGS. 1 and 2 ; and
[0021] FIG. 4 is a schematic side view of a second embodiment of a packaging machine according to the present disclosure.
DETAILED DESCRIPTION
[0022] Identical components are provided with identical reference numerals throughout the figures.
[0023] FIG. 1 shows a first embodiment of a packaging machine 1 according to the present disclosure in a perspective view. For the sake of clarity, only the packaging machine components which are most important to the disclosure are shown.
[0024] The packaging machine 1 is a deep-drawing packaging machine. It comprises (at least) three work stations, viz. a forming station 2 , an evacuating and sealing station 3 and a separating station 4 . All these work stations 2 , 3 , 4 act on a packaging material 5 , which, in this illustrated embodiment, is a continuous web of plastic foil. The forming station 2 is provided with a forming tool 6 . When the packaging material 5 is at a standstill during the intermittent operation of the packaging machine 1 , the forming tool 6 is moved perpendicularly to the plane of the web-shaped packaging material 5 so as to form packaging troughs in the packaging material 5 by deep-drawing.
[0025] The sealing station 3 comprises a sealing tool top 7 and a sealing tool bottom 8 . By moving the sealing tool top 7 and/or the sealing tool bottom 8 in a direction towards one another, a closed sealing chamber can be formed between the two tool members 7 , 8 . In said sealing chamber, the packaging trough, which has been filled with a product before conveyance to the sealing chamber, can be sealed with a top foil, which is not shown, and closed in this way. It is contemplated that it may be desirable to evacuate the sealing chamber and, consequently, the packaging trough between the two tool members 7 , 8 prior to sealing and/or to flush them with a replacement gas. After the sealing step, the sealing tool top 7 and the sealing tool bottom 8 are moved apart so as to release the packaging trough, and allow further transport of the packaging material 5 .
[0026] The separating station 4 is, in the present embodiment, a cross separator in which a separating knife 9 is provided as a tool member. This separating knife 9 can be moved vertically, i.e. perpendicularly to the plane of the packaging material 5 , so as to cut through the web-shaped packaging material 5 .
[0027] The packaging machine 1 defines a production direction R in which the packaging material 5 is conveyed through at least some of the work stations, such as, for example, in the present embodiment, through the sealing station 3 and the separating station 4 . In the forming station 2 , the packaging material 5 is conveyed in a direction opposite to the production direction R associated with stations 3 and 4 on the upper level before it is deflected about a virtual, horizontal axis 10 and thus transferred from a first conveying plane 11 (the lower level) to a second conveying plane 12 (the upper level).
[0028] The packaging machine 1 is provided with a frame 13 , which is arranged horizontally between the two material conveying planes 11 , 12 . The frame 13 comprises a plurality of lateral longitudinal bars 14 , which are oriented in the production direction R of the packaging machine 1 , as well as a plurality of cross bars (not shown) interconnecting said longitudinal bars 14 . At each work station 2 , 3 , 4 of the packaging machine 1 , the frame 13 is provided with two longitudinal bars 14 , which are oriented parallel to one another and which extend on the same level (i.e., in the same horizontal plane). These longitudinal bars 14 extend at least over the length of a work station 2 , 3 , 4 in the production direction R. In the packaging machine shown in FIG. 1 , a first pair of longitudinal bars 14 is associated with the forming station 2 . A second pair of longitudinal bars 14 extends below the sealing station 3 as well as below the separating station 4 . It is contemplated that the longitudinal bars 14 may, alternatively, extend over substantially the entire length of the machine, thus defining a uniform frame 13 for all work stations 2 , 3 , 4 .
[0029] A shaft 16 , which is also oriented in the production direction R of the packaging machine 1 , extends centrally between the longitudinal bars 14 . The shaft 16 is connected to a drive, e.g. an electric motor, preferably a servomotor. In the present embodiment, the shaft 16 can be driven alternately in different directions of rotation.
[0030] In the area of each work station 2 , 3 , 4 , a transfer mechanism 17 is operatively connected to the shaft 16 . The transfer mechanism 17 may be an arrangement of toggle levers and/or a cam mechanism. This transfer mechanism 17 insures that the rotary movement of the shaft 16 is converted into the desired movement of the movable tool member of the respective work station 2 , 3 , 4 , (such as, for example, the lifting movement of the forming tool 6 , of the sealing tool top 7 and/or of the sealing tool bottom 8 as well as the movement of the separating knife 9 ). Thus, the shaft 16 acts here as a “main shaft” which controls the movements of a plurality of movable tool members 6 , 7 , 8 , 9 of different work stations 2 , 3 , 4 . Due to the fact that the lifting movements are controlled in common via the shaft 16 , the movements of the tool members 6 , 7 , 8 , 9 are mechanically synchronized with one another.
[0031] At the separating station 4 , transfer mechanisms 17 are provided on either side of the shaft 16 so as to cause the separating knife 9 to move. The transfer mechanisms 17 are arranged symmetrically with respect to the shaft 16 (i.e., they extend at the same distance from the shaft 16 located between them).
[0032] The shaft 16 is supported in a plurality of cross bars (not shown) of the frame 13 . For supporting it, friction bearings or ball bearings 18 can be provided. In particular, the shaft 16 may be arranged centrally within the packaging machine 1 .
[0033] In FIG. 1 it can be seen that the forming station 2 is located below the plane of the frame 13 , whereas the sealing station 3 and the separating station 4 are located above the plane of said frame 13 . Due to this arrangement and due to the curved path of the packaging material 5 , a very compact structural design of the packaging machine 1 is accomplished. This has the advantage that the central shaft 16 can be comparatively short, so that torsional forces within the shaft 16 will be minimized.
[0034] FIG. 1 shows the packaging machine in a condition in which the tools 6 , 7 , 8 , 9 of the respective work stations 2 , 3 , 4 are open so as to allow further transport of the web-shaped packaging material 5 . FIG. 2 , however, shows the same packaging machine 1 in a condition in which the tool members 6 , 7 , 8 , 9 of the work stations 2 , 3 , 4 are closed so as to act on the web-shaped packaging material 5 . For example, the forming tool 6 of the forming station 2 is pressed downwards against the packaging material 5 so as to produce packaging troughs by deep-drawing the packaging material 5 . The movement of the forming tool 6 will be explained in more detail hereinbelow on the basis of FIG. 3 .
[0035] In the sealing station 3 , the sealing tool bottom 8 has been lifted so as to form, together with the sealing tool top 7 , a closed sealing chamber. This lifting movement of the sealing tool bottom 8 is accomplished by a rotation of the shaft 16 and by a conversion of the rotary movement of the shaft 16 into a lifting movement of the sealing tool bottom 8 by means of the transfer mechanism 17 . In the embodiment shown, this transfer mechanism 17 comprises a roll 17 a , which is adapted to be rotated about an axis oriented parallel to the production direction R and which is fixed on both sides by levers 17 b that are fixedly attached to the shaft 16 . A rotation of the shaft 16 has the effect that also the levers 17 b will rotate about said shaft 16 and, in so doing, lift the roll 17 a . This roll 17 a rolls on the lower surface of the sealing tool bottom 8 , said lower surface acting as a cam profile, i.e. the transfer mechanism 17 is here implemented as a cam mechanism.
[0036] A rotation of the shaft 16 additionally has the effect that the separating knife 9 of the separating station 4 is lifted in that the rotary movement of the shaft 16 is converted into a lifting movement of the separating knife 9 by means of the two laterally arranged transfer mechanisms 17 . The separating knife 9 cooperates with a counterknife 9 a so as to cut through the web-shaped packaging material 5 between the cutting edges of the two knives 9 , 9 a.
[0037] FIG. 3 shows an enlarged representation of the forming station 2 of the packaging machine 1 , in the case of which a few cover panels have been removed so that the interior of the forming station 2 , and, in particular, the transfer mechanism 17 , can be seen more easily. Just as in the case of the sealing station 3 , two levers 17 b are also here fixed to the shaft 16 so that they participate in the rotary movement of the shaft 16 . A roll 17 a , which is rotatable about an axis oriented parallel to the production direction R of the packaging machine 1 , is provided between the ends of the two levers 17 b that are remote from the shaft 16 . The roll 17 a is fully enclosed by two upright entraining plates 17 c which are secured in position on the forming tool 6 .
[0038] Starting from the half-open position of the forming station 2 shown in FIG. 3 , a rotation of the shaft 16 in direction A results in a lowering of the roll 17 a . During said lowering, the roll 17 a presses against a cam profile 17 d formed on the surface of the forming tool 6 so as to press the forming tool 6 downwards against the web of packaging material 5 . When the packaging troughs have been deep-drawn, an opposite rotation of the shaft 16 , i.e. a rotation in a direction opposite to direction A, has the effect that the roll 17 a will be lifted. Due to the entraining plates 17 c , the forming tool 6 will be lifted as well. An adjustment element 19 locks the transfer mechanism 17 in the longitudinal direction along the longitudinal bars 14 . As soon as this adjustment element 19 has been released or unlocked, the transfer mechanism 17 can be displaced in the longitudinal direction, i.e. in the production direction R, along the longitudinal bars 14 . Alternatively, it would be possible to displace the forming station 2 with the forming tool 6 in the longitudinal direction of the packaging machine 1 , whereas the transfer mechanism 17 would maintain its position on the shaft 16 .
[0039] FIG. 4 shows in a schematic side view a second embodiment of a packaging machine 20 according to the present disclosure. Also in the case of this embodiment, the packaging machine is a deep-drawing packaging machine 20 in which packaging troughs 21 are formed in a web-shaped packaging material 5 by means of deep-drawing in a forming station 2 . After having been filled with a product 22 , the packaging troughs 21 are transferred to a first sealing station 3 a . In said sealing station 3 a , the filled packaging troughs 21 are closed with a lid, which has previously been formed by deep-drawing in a second packaging material 25 in a second forming station 23 , said second packaging material 25 being also web-shaped and being unwound from a foil roll 24 .
[0040] During further transport the already closed packaging troughs 21 are transferred to a second sealing station 3 b in which a second top foil 27 , which is unwound from an additional foil roll 26 , is sealed onto the packaging troughs 21 . Whereas the forming station 2 is, just as in the case of the first embodiment, provided with a forming tool 6 for deep drawing, the two evacuating and sealing stations 3 a , 3 b have, just as in the case of the first embodiment, two sealing tool members 7 , 8 , such as, for example, a sealing tool top 7 and a sealing tool bottom 8 , which are adapted to be moved towards and away from one another.
[0041] The separating station 4 has, in the second embodiment, a cross separator 4 a and a longitudinal separator 4 b . In both separators 4 a , 4 b a separating knife 9 can be driven so as to execute a lifting movement for cutting through the foil web 5 . The work stations 2 , 3 a , 3 b , 4 a , 4 b of the packaging machine 20 are arranged on a common machine frame 28 . In this machine frame 28 a shaft 16 is arranged, which extends in the production direction R of the packaging machine 20 . Just as in the case of the first embodiment, the shaft 16 can be supported on a frame 13 . Each work station 2 , 3 a , 3 b , 4 a , 4 b has provided thereon a transfer mechanism 17 , preferably an arrangement of toggle levers or a cam mechanism, so as to convert the movement of the shaft 16 into a lifting movement of a tool member 6 , 7 , 8 , 9 of the respective work station 2 , 3 a , 3 b , 4 a , 4 b . Also the forming tool of the second forming station 23 can be driven by means of a suitable transfer mechanism 17 through the rotary movement of the shaft 16 such that it executes the desired lifting movement.
[0042] Starting from the embodiments shown, the packaging machine 1 , 20 according to the present disclosure can be modified in many respects. In particular, it is contemplated to provide further work stations and/or to drive further tool members of the existing work stations by means of the common shaft 16 .
[0043] According to another variant, it is also contemplated that at least one work station is provided with a transfer mechanism 17 in the case of which the rotary movement of the shaft 16 is converted into a linear movement, e.g. by implementing the shaft 16 as a spindle in the area of the work station and by providing a spindle nut which is attached to the shaft. The thus linearly movable spindle nut can drive a system of toggle levers for lifting and/or lowering (or for relative movement in another desired direction) a tool member.
[0044] Tool members, such as the forming tool bottom, forming tool top, sealing tool bottom or sealing tool top, can be implemented as replaceable components. The tools can preferably be removed from the packaging machine laterally (i.e., transverse) relative to the production direction. Since various media connections, such as electrical current, pressurized air, vacuum or cooling water, may be attached to the tools, these connections are configured such that they are easily releasable, preferably with a connection block which is also able to receive therein the various media and which provides the connection from the tool to the machine at the operating position. By providing suitable gasket systems and a releasable, locked condition of the tool at the operating position, the media connection may be automatically released and subsequently reestablished when a tool is changed.
[0045] A further embodiment of the deep-drawing packaging machine 1 , 20 is so conceived that, in the area of the forming and/or sealing station 2 , 3 , a lifting device is provided, which, perpendicular to the production direction R, executes a vertical lifting movement of a part of the feed system for the web-shaped packaging material 5 . The lifting movement of the feed system (such as, for example, by providing a lateral chain guide for a transport chain for transporting the packaging foil web 5 ) in the area of the forming station 2 has the effect that, when the forming station 2 is open, the web-shaped packaging material 5 will be spaced apart from the heating plate that heats the web-shaped packaging material 5 for the forming process, so as to prevent excessive heating of the web-shaped packaging material through radiant or contact heat. During the closing process of the forming station 2 , the feed system is returned to its operating position, so that the web-shaped packaging material 5 can effectively be heated and formed. A lifting function of the forming tool top can thus be dispensed with, and the space required in this area can be reduced.
[0046] The vertical lifting device of the feed system may also be provided in other areas as needed, such as, for example, the area of the sealing station 3 , if products projecting beyond the package edge, which normally also represents the sealing plane, are transported into the sealing station and if the sealing tool top 7 does not have a lifting function.
[0047] The displaceable area of the feed system is normally separate from the non-displaceable areas and is displaceable by means of pneumatic cylinders or servo drives and/or coupled to the movement of a tool bottom. A tensioning element for tensioning the transport chain could yield during the displacement of the feed system.
[0048] While embodiments of the disclosure have been illustrated and described, it is not intended that these embodiments illustrate and describe all possible forms of the disclosure. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the disclosure. | The disclosure relates to a packaging machine comprising a plurality of work stations which are operable in synchronism with one another and which define a production direction, each of said work stations including at least one movable tool member. The packaging machine is provided with a rotationally driven shaft arranged in the production direction of said packaging machine, and the shaft and each of the movable tool members of various work stations have provided between them at least one transfer mechanism for converting the movement of the shaft into the movement of the respective tool member. | big_patent |
RELATED APPLICATION
This application is a continuation-in-part of U.S. patent application Ser. No. 005,813 filed Jan. 21, 1987 for DISPOSABLE DEPRESSED CENTER GRINDING WHEEL HAVING AN INTEGRAL MOUNTING HUB INCLUDING A PRESSURE CAP which is a continuation-in-part of Ser. No. 847,793, filed Apr. 3, 1986 for DISPOSABLE DEPRESSED CENTER GRINDING WHEEL HAVING AN INTEGRAL MOUNTING HUB, now U.S. Pat. No. 4,694,615.
FIELD OF THE INVENTION
This invention relates generally to finishing articles and more particularly to such articles having a mounting hub permanently affixed thereto with the combination adapted for quick attachment and release to an appropriate portable power tool.
BACKGROUND OF THE INVENTION
The use of rotatably driven finishing articles is widespread and familiar in our industrial society. One of the more serious problems encountered in the use of such devices resides in the provision of effective means for preventing undesired or accidental disassociation of the article from the shaft, spindle or other rotatable drive means on which it is mounted. This problem is particularly acute when the connection between the article and its driving shaft or spindle is intentionally detachable to facilitate quick removal and replacement of the article. Into this category fall a host of devices, for example, portable powered grinders wherein the grinding wheels employed are intentionally detachable from the power driven shaft so that they may be readily replaced. To properly mount the grinding wheel upon the shaft provision must be made to provide sufficient clamping force and also to secure the wheel rotationally.
One means of securing the grinding wheel to the drive shaft has been to provide an appropriate backing flange with a central opening which is aligned with an opening provided in the depressed center abrasive grinding wheel. A bolt or nut member (depending upon the configuration of the drive shaft, that is, whether it is externally or internally threaded) is inserted from the face side of the grinding wheel and is then tightened in place. In this manner a plurality of loose parts are configured in a completed assembly ready for use. As the grinding wheel is utilized the appropriate clamping force is provided to securely affix the grinding wheel to the drive shaft. Such an assembly, however, typically requires appropriate tools such as wrenches or the like to remove the grinding wheel from the drive shaft. Such a device is shown in U.S. Pat. Nos. 489,149; 3,596,415; 1,998,919; 566,883; 507,223; 1,162,970; 791,159; 489,149 and 3,210,892.
Subsequently it became desirable to affix the mounting hub permanently to the grinding wheel so that the entire unit may be quickly and easily attached and detached from the drive shaft and discarded when the grinding wheel has been worn down. In these types of devices it is customary to utilize an adhesive such as an epoxy resin or the like between the backing flange and the back surface of the grinding wheel to retain integrity between the mounting hub and the grinding wheel to secure the wheel rotationally.
Even though the adhesive tended to work quite well in most applications, it was discovered that in some instances the adhesive would break loose and the grinding wheel would rotate relative to the mounting hub. Such was particularly the case since the hub was a one-piece member which was internally threaded and held in place upon the grinding wheel by swaging an extension thereof into place, thus providing a fixed clamping force holding the grinding wheel. No additional clamping force was exerted during further rotation of the wheel during use as was the case with the traditional nut which was secured from the face as above described. As a result various keyways and corresponding key structures were developed between the wheel and the mounting hub and used in conjunction with the adhesive to preclude rotational movement between the mounting hub and the grinding wheel. Examples of such devices are shown in U.S. Pat. Nos. 3,136,100; 4,015,371; 2,278,301; 3,081,584; 3,500,592; 3,800,483; 4,240,230 and 4,541,205.
Additional prior art patents known to applicant are U.S. Pat. Nos. 3,041,797; 3,879,178; 1,724,742; 3,912,411; 3,879,178; 3,960,516; 4,026,074; 4,054,425; 4,088,729; 4,322,920; 4,439,953; 4,449,329; 4,601,661; 791,791; 872,932; 2,567,782; 3,136,100, 3,210,892 and 3,621,621.
The devices utilized in the prior art for providing the disposable finishing article assembly including the permanent affixed mounting hub generally provide the service intended. There are certain inherent disadvantages found with regard to the various devices. Such disadvantages are that in manufacturing the utilization of an adhesive adds additional labor to the cost of manufacturing. In certain of the devices, parts must be keyed together and properly aligned in order to function appropriately. In addition thereto, through the utilization of die-cast mounting hubs which include as an integral part the backing flange there is no additional clamping force exerted upon the finishing article as it is being rotated by the power tool. Furthermore, such die-cast mounting hubs are relatively bulky, take up space and add substantial weight and additional cost to the completed product.
SUMMARY OF THE INVENTION
A finishing article having a drive member non-removably affixed thereto for mounting on a rotatable spindle of a power tool. The drive member includes a backing flange having gripping means radially extending therefrom secured by a retaining nut positioned on the opposite side from the backing flange. The retaining nut extends through an opening in the finishing article from the face toward the back of the finishing article and has a radial flange at one end thereof seated against the finishing article face and protrusion means extending outwardly from the other end thereof for non-removably securing the retaining nut and the backing flange together on the finishing article without the use of adhesives. A pressure cap defining a central opening is held in place by the gripping means on the backing flange and extends longitudinally away from the backing flange to engage the power tool spindle seat for placing the abrasive finishing article in compression during use thereof when the finishing article is operatively secured upon the spindle of the power tool.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross sectional view of a finishing article assembly constructed in accordance with the principles of the present invention and mounted in operable position on the spindle of a power tool;
FIG. 2 is an exploded view of the structure as illustrated in FIG. 1;
FIG. 3 is a cross sectional view taken about the lines 3--3 in FIG. 2 of a backing flange constructed in accordance with the present invention;
FIG. 4 is a cross sectional view of a retaining nut constructed in accordance with the principles of the present invention;
FIG. 5 is a cross sectional view of the retaining nut of FIG. 5 after being upset;
FIGS. 6 and 6a are a cross sectional view and fragmentary cross sectional view respectively showing construction of a pressure cap constructed in accordance with the present invention; and
FIG. 7 is a cross sectional view showing construction of an alternative embodiment of a pressure cap attached to a backing flange and constructed in accordance with the present invention.
DETAILED DESCRIPTION
By reference now to FIGS. 1 through 6, there is illustrated a preferred embodiment of a disposable finishing article drive member assembly constructed in accordance with the principles of the present invention. The finishing article constructed in accordance with the present invention may take many forms, such, for example, as grinding wheels, flap wheels, wire wheels, abrasive disks or pads, or the like. For purposes of ease of illustration and clarity of description only a depressed center grinding wheel will be shown and described. It will, however, be understood by those skilled in the art that other disposable finishing articles which may be placed in compression during use thereof may be substituted for the grinding wheel. As is shown in FIGS. 1 through 6, a depressed center grinding wheel 10 has a disposable drive member or hub assembly 12 permanently affixed thereto without the use of adhesives so that the grinding wheel may be attached to the threaded spindle 14 of an appropriate power tool 16. According to the principles of the present invention, a disposable mounting hub or drive member is constructed in such a manner that when the grinding wheel is placed in operation upon the spindle 14 the grinding wheel 10 is placed in compression and the more force that is applied to the grinding wheel during utilization thereof, the greater the operational compression becomes. As a result of placing the grinding wheel in such compression the grinding wheel is maintained upon the spindle and at the same time, through the compression or clamping force, the grinding wheel 10 cannot rotate relative to the drive member or hub assembly 12. However, as a result of the construction of the drive member, the spent grinding wheel may be easily removed from the spindle for disposal without the utilization of hand tools or the like.
As is clearly shown, the grinding wheel 10 includes a back surface 18 and a front surface 20. The central portion of the grinding wheel is depressed as viewed from the front thereof and as is shown at 22, with a corresponding central raised portion 24 on the back thereof. A centrally located aperture 26 is provided in the depressed center portion of the grinding wheel 10. The purpose of the depressed center of the grinding wheel 10 is to insure that the driving member or spindle does not protrude beyond the face portion 20 of the wheel 10 and thus interfere with a workpiece during the time the grinding wheel 10 is being utilized. However, when certain types of finishing articles are utilized such that the outer circumference is used instead of the face, then a depressed center may not be necessary or included in the article.
A backing flange 28 is provided and is adapted to be snugly received on the back surface 18 of the grinding wheel 10 about the raised portion 24. The flange 28 has a diameter which is less than the diameter of the wheel 10. The backing flange 28 defines a second central aperture 30 therethrough which is aligned with the aperture 26 in the grinding wheel 10. Reinforcing ribs 32, 33 and 34 are formed in the backing flange 28 concentrically with the opening 30. The backing flange 28 is preferably stamped from sheet metal but of course could be constructed from other materials such as hard molded plastic or die cast metal should such be desired.
As is shown more specifically in FIG. 3, the backing flange 28 includes an inner surface 36 and an outer surface 38. The inner surface 36 is disposed opposed the back surface 18 of the abrasive finishing wheel 10. The inner surface 36 includes lands 40, 41 and 42. The land 40 is formed about the outer peripheral portion of the backing flange 28. The lands 41 and 42 are displaced inwardly toward the opening 30 and away from the land 40. The land 40 always engages the back surface 18 of the abrasive finishing wheel away from the depressed center while the lands 41 and 42 may engage the back surface of the abrasive finishing wheel 10 opposed the depressed center 22 thereof depending upon variations in wheel dimensions and manufacturing tolerances in the wheels and flanges.
As can be seen, particularly in FIG. 3, the ribs 32, 33 and 34 formed in the outer surface 38 of the backing flange 22 are continuous. The continuous rib 32 is disposed between the lands 41 and 42 and over the transitional area between the depressed center and the remainder of the grinding wheel 10 while the continuous rib 33 and 33 are disposed intermediate the opening 30 and the land 42. The continuous rib 34 has gripping means such as a plurality of radially outwardly extending fingers 35, 37 and 39 formed therein. Preferably, when the backing flange 28 is fabricated from stamped sheet metal the fingers 35, 37 and 39 may be formed by cutting or punching the sheet metal during the stamping operation. Obviously if the backing flange is formed of molded plastic or metal, then the gripping means may take other forms and would be fabricated preferably during molding of the backing flange. The purpose and function of the gripping means will be described herein after.
As shown in FIG. 4, a retainer nut 44 includes a body portion 46 which is hollow and has a radially outwardly extending flange 48 at a first end 50 thereof. The internal surface of the body 46 has threads 56 formed therealong for attachment to the threaded spindle 14 of the power tool. The nut 44 is inserted through the aperture 26 in the grinding wheel and the aperture 30 in the flange 28 from the front surface 20 toward the rear surface 18 of the grinding wheel 10. The end 52 of the nut 44 extends through the opening 30 in the flange 28.
The nut 44 is preferably constructed from an aluminum extrusion which is then machined to provide the flange 38 and the threads 46. Alternatively the nut may be formed from aluminum or steel bar stock, or a metal die casting, or molded plastic.
Once the nut 44 has been inserted through the openings in the wheel 10 and the flange 28, the end 52 thereof is upset such as by a staking operation to provide a protrusion 56 extending outwardly therefrom as shown specifically in FIG. 5. The protrusion may be formed as a series of separate protrusions, or, as shown, as a continuous protrusion. Preferably the protrusion is formed by staking operation which forms a continuous groove 54 in the end of 52 of the nut 44. Formation of the groove 54 causes the displaced material to form a lip or overhang 57 which will overlie the back of the backing flange 28 about the opening 30 therethrough. It should become apparent to those skilled in the art that the flange 28 and the nut 44 are secured together on the wheel 10 between the flange 48 and the overhang 57 without the use of adhesives.
To provide proper operational compressive forces of the throwaway grinding wheel as above-described, a pressure cap 60 is snapped into locking engagement with the hub assembly 12. The pressure cap includes a first or rear surface 62 for engaging a surface 64 on the power tool spindle when the grinding wheel is in an operable position on the power tool 16. A second or front surface 66 on the pressure cap 60 contacts the top of the continuous rib 34. The pressure cap 60 is retained in position on the hub assembly 12 by a gripping rib 68 which extends radially inwardly from a downwardly depending skirt 70 on the body 72 of the pressure cap 60. The gripping rib 68 snaps over the digital ends 35, 37 and 39 of the fingers 35, 37 and 39 respectively as is more clearly shown in FIG. 1. The gripping rib 68 includes an upwardly sloping surface 74 which allows easy assembly of the cap 60 on the flange 28. The body 72 of the pressure cap 60 defines an aperture 61 for receiving the spindle 14 of the power tool. When assembled on the backing flange 28 the apertures 26, 30 and 61 are aligned axially. As is more clearly shown in FIG. 2 the pressure cap includes a plurality of stiffening ribs 63 formed integrally therewith disposed between the surfaces 62 and 66. As will be noted, when the grinding wheel is in use on the power tool compressive forces are transmitted through the body 72 of the pressure cap 60 between the surfaces 62 and 66. The bulk of the body 72 betWeen surfaces 62 and 66 and the stiffening ribs 63 carry these forces. Preferably the pressure cap 60 is constructed of molded plastic such as polypropylene, nylon, acetal or the like. The gripping rib 68 may be continuous or intermittent as desired as illustrated by the lines 69. An important feature is that the pressure cap may be easily snapped into locking position as shown in FIG. 1 by the distributor or user before use if desired or, alternatively, at the time of assembly in the factory. Such capability saves space in shipment in that the assembled wheel without the pressure cap may be packed in containers with pressure caps placed in interstices between wheels or wheels and the container. Thus a greater number of wheels may be packaged, on top of each other, in the same container.
The pressure cap 60, once installed, remains on the grinding wheel and is disposed of along with the spent wheel. Through utilization of the gripping rib 68 and fingers 35, 37 and 39 it is surprisingly easy to assemble the pressure cap 60 with backing flange 28 and surprisingly difficult to remove the pressure cap 60 once it is snapped into place. Such removal, if desired, can only be accomplished with the use of a tool to pry the cap 60 loose.
The force necessary to cause the grinding wheel 10 to be placed in compression is generated upon attachment of the spindle 14 to the threads 56 in the nut 44. By reference to FIG. 1 it will be noted that when the grinding wheel is threaded upon the spindle 14 the surface 62 engages the spindle seat 64. The interengagement between the threads 14 and 56 of the spindle and nut, respectively, urge the nut upward toward the flange 28 as the wheel is seated upon the spindle. At the same time, the spindle seat 64 applies a downward force to surface 62 of the pressure cap 60 which in turn, through the surface 66 applies a downward force to the flange 28. Therefore, this mutual clamping force causes the grinding wheel to be placed in compression. Those skilled in the art will recognize that as the grinding wheel 10 is used by being placed against a workpiece, additional torque is applied causing the grinding wheel to be further tightened onto the spindle 14. That is, as the grinding wheel moves during contact with a workpiece, the friction between the nut and the grinding wheel center causes the nut to rotate in a further tightening direction. Such rotation of the nut further urges the nut toward the flange which in turn applies a further force to the flange. The more the grinding wheel is tightened the greater the operational compression force becomes and the more securely the grinding wheel 10 is clamped between the backing flange 28 and the flange 48 on the nut 44. As a result of this strong clamping or compression the grinding wheel 10 is precluded from movement relative to the hub or driving member 12 and at the same time is precluded from disengaging from the spindle 14. Referring now more specifically to FIG. 7, there is illustrated an alternative embodiment of a pressure cap constructed in accordance with the teachings of the present invention. As is therein shown, the pressure cap 80 includes a radially outwardly directed gripping rib 82. The gripping rib 82 snaps into engagement with a plurality of radially inwardly directed fingers 34 formed in the continuous reinforcing rib 32 of the backing flange 28. A surface 86 contacts the rib 84 (which would not have the finger 35, 37 and 39) to assist in placing the finishing article in compression as above described.
It will be recognized by those skilled in the art that the grinding wheel assemblies as illustrated in FIGS. 1 through 7 and as above described require no adhesive for construction and may be simply and easily assembled, are relatively light in weight as compared to the prior art devices utilizing the cast hubs and provides a secure attachment of the abrasive finishing article to the power tool and through the utilization of the increased compression precludes relative rotation of the grinding wheel with respect to the driving member. It has also been discovered that the utilization of the device as above described and as constructed in the preferred embodiment is extremely smooth in operation with no vibration. The reason for such extremely smooth operation is that all of the parts are perfectly aligned one with the other with the abutting surfaces parallel when in compression and only the wheel 10 can cause any vibration and then only if it is not properly balanced during the construction thereof.
Through the structures as illustrated and described, all currently known sizes of standard diameter depressed center grinding wheels, namely four inch, four and one half inch, five inch, seven inch and nine inch may be accommodated. At the present time, through the utilization of the die-cast integral hub-flange structure, only seven and nine inch grinding wheels utilize the throw away hub while the four, four and one half and five inch wheel utilize the conventional two-piece mounting set traditional in the prior art and as above described.
There has thus been disclosed a disposable finishing article driving member assembly which securely holds the articIe during operation, which is light in weight, vibration-free, and less expensive than prior art throw-away articles while meeting all safety standards currently known and in existence. | A disposable finishing article for mounting on a rotatable threaded spindle of a power tool. The finishing article contains a retaining nut on one side and a backing flange on the other non-removably secured together on the finishing article without the aid of adhesives in such a manner that the finishing article is placed in compression when it is operably secured upon the spindle of the power tool under operative loads. The nut and flange are secured together by upsetting one end of the nut causing it to protrude outwardly over the outer surface of the flange. A pressure cap member is secured to a plurality of fingers formed on the backing flange for engaging a shoulder formed on the spindle of the power tool during operation of the finishing article. | big_patent |
BACKGROUND OF THE INVENTION
The invention is based on a generic hydraulic unit for a vehicle brake system. From European Patent Disclosure EP 0 621 836 B1, one such generic unit is known that is embodied as immersion-proof. The hydraulic unit has at least one pump that has a piston, and the piston is indirectly drivable by an electric motor via an eccentric that is rotatable inside an eccentric chamber. Because it cannot be precluded that the moving piston may entrain pressure fluid into the eccentric chamber through a sealing ring or the like on the occasion of pump operation, a conduit extends downward from the eccentric chamber and opens to the atmosphere through a housing block that receives the at least one pump; a check valve that can open toward the atmosphere is built into the conduit. Pressure fluid that has been entrained into the eccentric chamber and drips from the piston enters the conduit and stresses the check valve, causing it to open, and finally flows out of the housing block. As a result, filling of the eccentric chamber with pressure fluid is averted, so that pressure fluid remains far away from the electric motor, or in other words does not penetrate the electric motor and impair the operability thereof.
In a hydraulic unit known from International Patent Disclosure WO 96/13416, the electric motor is located above an eccentric chamber, in which the eccentric acting on at least one piston of a pump is rotatable. Once again, a conduit leads downward from the eccentric chamber, directly or indirectly to a so-called central venting point, where an element is installed that is permeable to air but not to water from the environment, so as to equalize the pressure of the eccentric chamber, for instance, relative to the ambient atmosphere and on the other hand to prevent at least splashing water from entering the unit. As an additional provision, the central venting point may have a check valve mentioned in this aforementioned patent disclosure. For instance, a check valve disclosed in the first reference cited, EP 0 629 836 B1, could be used. The unit also has at least one reservoir intended for temporarily receiving pressure fluid; it comprises a cylindrical hollow chamber closed off from the ambient atmosphere, a piston displaceable in the chamber that divides the hollow chamber into a variable storage chamber and a spring chamber, and a spring acting on the piston. The spring is braced on a cap that tightly closes off the hollow chamber. Extending from the spring chamber, adjacent to the cap, a pressure equalization conduit, which leads either upward to an inner hollow chamber in the electric motor or downward to a hollow chamber in a covering hood. The covering hood covers electromagnets of valves of the unit, as well as electrical components that are disposed on a circuit board. In operation of the unit, pressure fluid entrained into the eccentric chamber by a piston of the pump drips directly into the covering hood, for instance, so that it cannot be precluded that electrically operative components will become moistened with the pressure fluid.
OBJECT AND SUMMARY OF THE INVENTION
The characteristics set forth herein offer the advantage that pressure fluid entrained into a cam element chamber, which for instance may be an eccentric chamber, by motions of the piston pump piston, are delivered to the at least one spring chamber, far from electrical components, and collected in that chamber. Because the entrained pressure fluid is collected in the spring chamber, permeable elements at a central venting point as in the prior art, or a check valve as in the prior art, can conditionally be dispensed with. To this extent, the invention yields cost savings as well as the advantage of a hermetic seal of the unit from the environment. The housing block together with the at least one pump can be immersed and submerged, for instance in salty water, without the risk of damage.
With the provisions recited herein, advantageous refinements of and improvements to the hydraulic unit defined are possible.
The characteristics set forth offer the advantage that because of dual utilization of conduit portions, the housing block can be produced economically, on the one hand having fewer conduits and on the other by cleaning these fewer conduits after they have been produced.
The characteristics set forth herein offer the advantage that a housing block, known from EP 0 699 571 A1, for a hydraulic unit of a vehicle brake system can be used without changing its size or its basic internal design, so that the only provision necessary is the disposition of the characteristics set forth hereinafter. The engineer can decide how much pressure fluid entrained by the at least one piston of the at least one pump should be stored. If the hydraulic unit is intended merely to avoid the danger of wheel locking, then the at least one container will be made smaller than if the hydraulic unit is additionally designed for automatic braking and for traction control of driven wheels or for stabilization while driving. This is because automatic braking can involve more-frequent activation of the at least one pump.
The characteristics defined herein offer a practical exemplary embodiment for such containers with recourse to deep-drawing techniques known per se. The characteristics set forth herein offer the advantage that in a favorable way from a production standpoint, the invasion of water between a fastening portion of the container and the housing block is averted.
The features set forth offer the advantage on the one hand that the motor can be delivered complete to an assembly line, along which the motor is moved toward the housing block and fixed to it, and as a further advantage at the same time an intended sealing off against the invasion of water from the environment into the motor and into the cam element chamber located in the housing block is avoided. The characteristics set forth also offer the advantage that the seal can be made in a favorable way from a production standpoint, and because of the resultant geometrical design of the seal, less sealing material is consumed. Since the sealing material can be mounted in the form of a worm of closed circular-annular shape, both the aforementioned sealing and sealing off of the pressure-equalizing conduit relative to the environment are attained by means of such a worm.
The characteristics defined herein bring about a pressure equilibrium between the motor and a covering hood, which contains such electrically operative components as relays or semiconductor elements and which thus also protects electromagnets of valves of the hydraulic unit from the harmful effects of the environment by sealing them off from the environment. Pressure equalization of both the motor interior and the covering hood with regard to the atmosphere is done in a way that is gentle to the unit, by making use of a cable sheath, joined in sealed fashion to the covering hood, and this sheath is terminated at the highest possible point in the vehicle, to avert the risk that water can enter a partially immersed vehicle. To this extent, it is possible to avoid the provision of a pressure equalization hose, which begins at a lowest point of the hydraulic unit and then rises, as disclosed in WO 96/13416, a hose that serves the sole purpose of pressure equalization.
The invention will be better understood and further objects and advantages thereof will become more apparent from the ensuing detailed description of preferred embodiments taken in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a first exemplary embodiment of the hydraulic unit according to the invention in a side view and partially cut away;
FIG. 2 shows a cross section of the unit of FIG. 1 along line II--II;
FIG. 3 shows a component of the hydraulic unit in an oblique view;
FIG. 4 shows a detail of the hydraulic unit of FIG. 1 in an end view;
FIG. 5 shows an electrical component in a cutaway view for the unit of FIG. 1;
FIG. 6 shows a second exemplary embodiment of the unit of the invention, partly cut away; and
FIG. 7 shows a third exemplary embodiment of the unit of the invention, again partly cut away.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
First Exemplary Embodiment
The hydraulic unit 2 of the invention includes as its essential components a housing block 3 and, mounted against the housing block 3, a motor 4, which is shown only in FIG. 3, as well as a housing 5 and a covering hood 6. Because the hydraulic unit 2 to this extent largely agrees with the hydraulic unit of EP 0 699 571 A1, a relatively brief general description will suffice, so that characteristics essential to the invention will be more apparent.
A securing face 7 for the motor 4 is located on a face end A of the housing block 3, as shown in FIGS. 1 and 4. Extending vertically to this securing face 7 in the housing block 3 is a stepped bore 8, which defines an eccentric chamber 9. A shaft trunnion 10, which by means of a ball bearing 11 that is supported by the stepped bore 8, determines a pivot axis 12 for an eccentric 13 that is embodied integrally with a shaft 14. The shaft 14 extends from the eccentric 13 into the motor 4. The motor may be embodied in a manner not shown as a direct current motor, with an armature and collector that are not shown and may be equipped with contact brushes, also not shown, that are associated with the collector. In addition, it will be noted here that the eccentric 13 shown is a cam element known per se, as well as known swash plates and other cam curves. Accordingly, to avoid unnecessary limitation here, the eccentric is also understood to be a cam element, and correspondingly in an expanded sense a cam element chamber is intended in place of an eccentric chamber 9.
A cross section through the eccentric 13 is shown in FIG. 2. In FIG. 2, the shaft 14 adjoining the eccentric 13 behind it can also be seen. In FIG. 3, the sequence of a shaft trunnion 10, eccentric 13 and shaft 14 is clearly shown. Disposed around the eccentric 13 is for instance a needle bearing 15, which is held together by a bearing ring 16. Axial stop means 17, 18 for the bearing ring 16 are provided on both sides of the bearing ring 16. The bearing ring 16 is rotatable relative to the eccentric 13 between these axial stop means 17 and 18. The stop means 17 has a hub 19, which is seated fixedly on the shaft 14. The axial stop means 18 is in the form of an outer conical ring and is press-fitted, firmly seated, onto the eccentric 13. These individual parts are shown in FIG. 1. In FIG. 2, crosswise to the pivot axis 12 of the eccentric 13 and thus coaxially and in mirror symmetry with the eccentric 13, two pump pistons 20, 21 are provided. The pump pistons 20, 21 are displaceable in pump cylinder bores, not shown, that are located in pump cylinders 22 and 23. The pump cylinders 22 and 23 are combined with outlet valves 24 and 25, respectively, thus forming two piston pumps that are operative independently of one another and have inlets 24a and 25a. In a manner known per se, these inlets 24a and 25a are assigned inlet check valves, not shown, inside the piston pumps. The piston pumps 22, 23 are fixed in the housing block 3, for instance by means of caulked features 26, 27. To generate pressure, the pump pistons 20 and 21 are displaceable longitudinally by means of the eccentric 13, which has earlier also been called a cam element, with the interposition of the needle bearing 15 and its bearing ring 16. For displacement in the respective opposite direction, a C-shaped spring clip 28 firmly hooked onto the pump pistons 20 and 21 is used.
In FIG. 2, first cylindrical bores 30, 31, which are drilled vertically from below into the housing block 3 in the manner of blind bores, are located below the elements 20, 22, 24 and 21, 23, 25 of the respective piston pumps 22, 23. In the bores 30 and 31, pistons 34 and 35, so-called storage pistons, that are loaded by springs 32, 33 are provided. Sealing rings 36 and 37, respectively, assure that sealed-off storage chambers 38 and 39 are available, above the pistons 34, 35, for receiving pressure fluid. Connecting conduits 30a and 31a extend upward from the cylindrical bores 30 and 31 and connect the storage chambers 38 and 39 to the inlets 24 and 25a of the two piston pumps 24 and 25. Below the pistons 34 and 35, the cylindrical bores 30 and 31 form spring chambers 30b and 31b. The springs 32 and 33 are retained inside the cylindrical bores 30 and 31 by means of spring plates 32a and 33a, which in turn are braced rigidly in the housing block 3 by means of spring wire rings 32b and 33b. The connecting conduits 30a and 31a communicate with lower stepped bores 52, located above the piston pumps 24, 25, which bores serve to receive multiposition valves 53, shown schematically in FIG. 1, that are actuatable by means of electromagnetic coils 55. The multiposition valves 53 in the exemplary embodiment are so-called brake pressure reduction valves. Also shown in FIG. 2 are upper stepped bores 50, to which in FIG. 1 multiposition valves 51 with electrical coils 54 are assigned. Because the subject of the invention does not pertain to the hydraulic interconnection of multiposition valves with wheel brake cylinders and a master cylinder, further details need not be addressed here.
In a manner according to the invention, first conduit portions 101, 102 and 103 extend downward, beginning at the eccentric chamber or cam element chamber 9. The conduit portion 101 is made in the manner of a bore that intersects the stepped bore 8 at its lowest point and thereby forms a kind of channel and in its further course extends in the form of a cylindrical bore, for instance parallel to the pivot axis 12 of the eccentric 13. The conduit portion 101 ends in the manner of a blind bore. Intersecting the conduit portion 101 and in the process discharging into this conduit portion 101 is the conduit portion 102, which is drilled in from an underside of the housing block 3 and is closed off, adjoining the underside, by means of a ball 104 press-fitted into place. The conduit portion 103 in turn is made in the form of a bore that begins at one side of the housing block 3, intersects the cylindrical bore 30, discharges into the conduit portion 102 and intersecting the latter extends onward, finally discharging into the bore 31. The conduit portions 101-103 form a conduit oriented downward from the cam element chamber 9 and discharging into the spring chambers 30b and 31b. It can be seen that pressure fluid dripping from the ends, visible in FIG. 2, of the pistons 20 and 21 find a path out of the cam element chamber 9 and into the spring chambers 30b and 31b. The pressure fluid dripping off is the same pressure fluid mentioned in the description of the prior art, which on the occasion of the operation of the piston pumps 22 and 23 passes through sealing rings, not shown, or in other words has been entrained between sealing faces.
To prevent dirt and water from penetrating the bores 30, 31 from below, these bores are closed by means of closure elements 106 and 107. In the exemplary embodiment, the closure elements 106 and 107 perform the task both of a cap as in the prior art and the task of catching pressure fluid according to the invention, fluid that has been diverted out of the eccentric chamber 9 by means of the first conduit portions 101, 102 and 103.
The respective closure element 106 and 107 is produced here in the form of a substantially cup-shaped deep-drawn part, next to whose free edge 108 a bead 108 is first disposed, the bead subsequently being upset to form a flangelike axial stop as shown. With the free edge 108 leading, the closure element 106 and 107 is press-fitted into the respective spring chamber 30b and 31b. This already creates a certain sealing, which is supplemented by a sealing element 110, which in a manner that can be selected from the prior art for instance be a prefabricated sealing ring, or a worm of initially liquid silicon rubber, applied before the closure elements 106 and 107 are built in, which over the course of time, changes into a rubber-elastic state. It is shown in FIG. 2 that the upper free edges 108 and these closure elements 106 and 107 are located below the conduit portion 103. To this extent, pressure fluid from the conduit portion 103, for instance, can get into the two bores 30, 31 along the sealing rings 32b, 33b and flow downward into the closure elements 106 and 107. It will be appreciated that the greater the axial length of the closure elements 106 and 107, the more pressure fluid can be received before collected pressure fluid reaches the level at which the conduit portion 103 is disposed. In order that no pressure fluid will reach the outside even from a beginning of a bore portion that belongs to the conduit portion 103, a ball 105 is press-fitted as a closure piece into the housing block 3.
In addition it will be noted that the respective closure elements 106 and 107, each assigned to one of the bores 30 and 31, can be exchanged for a common cap in the manner of a cap shown in European Patent Disclosure EP 0 662 891 B1, which according to FIG. 2 thereof is embodied in substantially tub-shaped fashion and is braced against the housing block with the interposition of a seal. If such a cap is used, then the disposition of the ball 104, the conduit portion 103, and the ball 105 that seals off the conduit portion 103 from the outside, as shown in FIG. 2 of the present application, may be dispensed with.
A generic pressure equalization conduit between at least one spring chamber 30b, 31b and the interior 111 of the motor 4 includes the first conduit portions 101, 102 and 103 and the eccentric chamber or cam element chamber 9 and finally two conduit portions 112 and 113. The conduit portion 113 is embodied as a hole in an end wall 114 of the motor facing toward the housing block 2. The conduit portion 112 is embodied in the manner of a bore cut halfway open, for instance, which intersects the contour of the stepped bore 8 and is embodied in comparable fashion to a portion of the conduit portion 101 that has been described above. Located between the conduit portions 112 and 113 is a conduit portion 115, which is located radially inside a sealing element 116 that is located between the end wall 114 of the motor and the securing face 7 furnished by the housing block 3. In FIG. 4, this sealing element 116 is embodied as extending annularly and is either stamped out of a sealing material or injection molded from it, or preferably, as described for the sealing element 110 of the closure elements 106 and 107, made from an initially liquid sealing material such as silicone rubber by being poured or sprayed onto the securing face 7. A sealing element produced in this way is sometimes also called a sealing worm and here has a thickness, measured in the axial direction of the motor 4, of substantially 2 mm, for instance. Radially inside this sealing element 116, it is possible to dispose support elements 117, which for instance are four in number and for instance are elastic.
It can now be appreciated that beginning at the eccentric chamber 9, the conduit portion 112 extends radially outside a centering attachment 118, which receives a ball bearing not shown and originates at the end wall 114 of the motor extending toward the eccentric 13, between the end wall 114 and the securing face 7 located on the housing block 3 and thus radially inside the sealing element 116, and finally continues in the form of the conduit portion 113 that is formed by a hole in the end wall 114 of the motor. This brings about a pressure equilibrium between the interior 111, that is, a hollow chamber of the motor 4, and the eccentric chamber 9. Together with the first conduit portions 101, 102 and 103 that were described first, a pressure equalization conduit exists between the at least one spring chamber 30b, 31b and the interior 111 of the motor 4; when at least one of the two pistons 34, 35 moves counter to the force of the respective spring 32, 33, the pressure equalization conduit allows air to escape from the respective spring chamber 30b, 31b into the interior 111, the purpose of which is that a displacement resistance of the respective piston 34 or 35 is determined essentially by the force of the respective spring 32, 33. It can be seen that to divert pressure fluid out of the eccentric chamber 9 and for equalizing pressure between the spring chambers 30b and 31b and the interior 111 of the motor, first conduit portions 101, 102 and 103 are utilized in two ways. This provides a cost savings compared with two separately embodied conduits, of which one would be used to carry away pressure fluid and the other would be used for pressure equalization.
Shown in FIG. 1 is a cable 64, which originates at the housing 5 and leads to the motor 4 to supply current to it. The housing 5 is a housing in which a relay, for instance, for switching the electric current for the motor 4 is disposed. In a manner according to the invention, a pressure equilibrium is created between the interior 111 of the motor 4 and the housing 5, which is sealed off relative to the housing block 3. The purpose of pressure equalization is served here by a pressure equalization conduit, which is formed by interstices between wires 120 of the cable 64 and a tubular cable sheath 121 that sheathes the wires 120.
Oriented toward the housing 5, the cable sheath 121 is surrounded by a sealing sleeve 122, which is inserted sealingly into a plug portion 123. The plug portion 123 in turn has a further sealing sleeve 124 on its outside, which becomes operative upon insertion of the plug part 123 into a socket that is located in the housing 5. Contact clips 125 are provided inside the plug part 123 and are electrically connected to the wires 120 by digging into them. It can be seen that because of the embodiment of the contact clips 125 as a bent sheet-metal part with a central portion 126, a flow is possible through the plug part 123, from the contact clips 125, to in between the wires 120 shown and from there on between the wires through the cable sheath 121.
In a comparable way, the cable sheath 121 is introduced into a further sealing sleeve 127, which is located inside a second plug part 128. Instead of the contact clips 125 already described, a plug prong 129 is electrically connected to the wires that extend inside the cable sheath 121. The electrical connection can once again be made in a manner known per se by digging action, to which end the plug prong 129, protruding into the sealing sleeve 127, has a tubular prolongation that is crimped toward the wires 120. To allow a flow of air around the plug prong 129, this prong is aligned by means of centering ribs 130 inside the plug part 128. A contact bush, not shown, is associated with the plug prong 129 inside the motor 4, and a brush holder, also not shown, is for instance connected to the contact bush. The centering ribs 130 extend radially outward from a tubular portion 131. A sealing element 132 that has sealing ribs 133 oriented toward the motor 4 is slipped over this tubular portion 131. To enable the sealing ribs 133 to be pressed sufficiently firmly against the motor 4, fastening tabs 134 with screw holes 135 are formed onto the plug part 128. One fastening tab can be seen in FIG. 1. The screw hole 135 is not visible, because it is covered by the head 136 of a fastening screw.
The cable sheath 121 is connected at least indirectly to the connection cable 140 in a way that equalizes pressure; the connection cable 140 likewise comprises a cable sheath 141 and in this case a plurality of sheathed connection strands 142.
By means of elements 143 and 144, not described in detail, which can be learned from the prior art in electrical connection technology, a connection is made with a sealed plug base 145 located on the housing 5. This prevents water from entering between an end of the cable sheath 141--this end is not visible in the drawing--and the housing 5. In a manner according to the prior art, contact elements not shown are disposed in the plug base 145 and the connection part 144 in such a way that beginning at the connection strands 142, once again air flow possibilities are present, which can be from the cable sheath 141 into the housing 5 or in the opposite direction. The connection cable 140 is extended upward inside the vehicle to the highest possible point, of which it can be assumed that no water will get into it. As a consequence, in an intended way, the cable sheath 141 acts as a pressure equalization conduit between the ambient atmosphere and the interior of the housing 5 and indirectly through the cable sheath 121 for the motor 4 as well.
The provisions described in detail thus directly prevent the invasion of water to the hydraulic unit 2 yet nevertheless provide a pressure equalization of interiors of the hydraulic unit 2 with the ambient atmosphere, and they moreover bring about the diversion of pressure fluid, entrained by pump pistons, into a region of the unit that is located far from vulnerable electrical parts of the hydraulic unit. This prevents electrolytically active ingredients that may be present in the pressure fluid from attacking electrical components or rendering them inoperative.
Second Exemplary Embodiment
The second exemplary embodiment of an anti-lock brake system 2a of FIG. 6 is embodied identically, in terms of the diversion of pressure fluid entrained by pump pistons, to the first exemplary embodiment shown in FIGS. 1, 2, 3 and 4. In FIG. 6, therefore, of the first conduit portions only the conduit portion 101 originating at the cam element chamber 9 and a portion of the length of the conduit portion 102 extending downward from the conduit portion 101 are shown. In a distinction from the first exemplary embodiment, the component 118 here serves the purpose of centrally receiving a ball bearing, not shown. This ball bearing, not shown, is intended to embrace the shaft 14 and thus support it centrally with respect to the motor 4. In the region of the component 118, the stepped bore 8 is therefore embodied such that an annular second conduit portion 112a opens up between this bore and the component 118. In the direction toward the interior 111 of the motor, a further, second conduit portion 115 adjoins it; as in the first exemplary embodiment, this conduit portion extends inside a sealing element 116, between a securing face 7 of a housing block 3a and an end wall 114 of the housing. Once again, a further, second conduit portion 113, which is embodied as a hole in the end wall 114 of the motor, connects the second conduit portion 115 to the interior 111 of the motor 4.
An upper screw head 150 and a lower screw head 151 of two screws 150a and 151a are shown in fragmentary form in FIG. 1, and FIG. 3 they are shown passed through the motor 4 in order to secure it by being screwed into the housing block 3a. To that end, as shown in FIG. 4, two threaded holes 152 and 153 are provided in the housing block. To prevent entrained pressure fluid, which may possible escape from the cam element chamber 9 through the second conduit portion 112a between the securing face 7 and the end wall 114 of the motor, from reaching the threaded hole 115 and thus from flowing along the lower screw 151a to reach the interior of the motor 4, a sealing strip 116a, extending for instance with a uniform curvature, also extends around the threaded hole 153 from the sealing element 116.
In the second exemplary embodiment of FIG. 6, the motor has two bearings for the shaft 14 on either side of an armature, not shown. One of the two bearings is the ball bearing, already mentioned, in the component 118. When such a motor 4 is mounted on the housing block 3a, the centering of the motor relative to the cam element chamber 9 is accomplished when the shaft trunnion 10 is plugged into the ball bearing 11 located in the housing block 3a.
As described for the first exemplary embodiment, here as well the sealing element 116 and the sealing strip 116a can selectively be poured or sprayed from sealing medium or stamped out from a plate.
Third Exemplary Embodiment
The third exemplary embodiment of the hydraulic unit 2b of the invention as shown in FIG. 7 takes over the housing block 3a of the second exemplary embodiment shown in FIG. 6, for instance, so that entrained pressure fluid, which originates in pump elements 22, 23 and is to be diverted out of the cam element chamber 9, can flow downward through conduit portions 101, 102, far away from the interior 111 of the motor 4.
The pressure equilibrium between the cam element chamber 9 and the interior 111 of the motor is provided by an opening in the component 118 that discharges as a second conduit portion into the cam element chamber 9; this opening forms an annular second conduit portion 113a that surrounds the shaft 14. This second conduit portion 113a is adjoined by a further second conduit portion 113b, which extends between an inner ball bearing ring 118b, embracing the shaft 14 and an outer ball bearing ring 118a that is horizontal relative to the housing block 3a, and in the process extends between bearing balls 118c. Since on the other hand in a manner already described the cam element chamber 9 communicates with the spring chambers 30b and 31b through first conduit portions 101, 102 and 103, a pressure equilibrium between the spring chambers 30b and 31b and the interior 111 of the motor 4 is again possible through the cam element chamber. This third exemplary embodiment makes do without openings, shown in FIGS. 1, 2, 3 and 6, each of them forming one second conduit portion 113, and this makes production cheaper.
In addition it will also be noted that in the third exemplary embodiment of FIG. 7, the second conduit portions 112a, 115 and 113 of the second exemplary embodiment shown in FIG. 6 can also be adopted, for the sake of promoting a pressure equilibrium between the spring chambers 30b, 31b and the interior 111 of the motor 4.
The foregoing relates to preferred exemplary embodiments of the invention, it being understood that other variants and embodiments thereof are possible within the spirit and scope of the invention, the latter being defined by the appended claims. | A hydraulic unit for a vehicle brake system that enables limiting wheel brake slip is known. To that end, the hydraulic unit has at least one piston pump, which is drivable by an electric motor and empties a reservoir that is filled on the occasion of the limitation of wheel brake slip. This reservoir comprises a cylinder, embodied in the manner of a blind bore, as well as a piston that divides a storage chamber from a spring chamber in the cylinder, a spring, and a closure element that prevents water from entering the cylinder if the hydraulic unit should become immersed in water. A pressure equalization conduit begins at the spring chamber and leads into the interior of the motor, so that a displacement of the piston for taking up pressure fluid in the storage chamber is effected essentially only by friction of the piston and forces of the spring. A conduit is also provided, by means of which pressure fluid that emerges from the piston pump at the eccentric can be carried away. The invention proposes connecting the spring chamber of the reservoir to the conduit that carries the pressure fluid away. The spring chamber forms a collection container for pressure fluid, as a result of which the collection of the pressure fluid takes place far away from electrical components of the hydraulic unit, and especially of the motor, thus avoiding electrical defects. | big_patent |
This invention relates to conveyor systems and particularly to power and free conveyor systems.
BACKGROUND OF THE INVENTION
In power and free conveyor systems wherein carriers are moved along predetermined paths by engagement with conveyors, it is often necessary to transfer the carriers from one predetermined path to another. In one type of system, this transfer is achieved by providing a transfer conveyor that engages the carrier and transfers it between the predetermined paths. In another type of system, the carrier is moved from one path toward the other and then pushed through the transfer area to the second path.
The invention is also applicable to the transfer of a carrier from one powered conveyor to another, either from a faster to a slower conveyor or from a slower conveyor to a faster conveyor or between conveyors moving at the same speed.
In U.S. Pat. Nos. 3,640,226, and 3,662,873, there is shown a power and free conveyor system wherein each of the carriers has a second dog that is normally urged to operative carrier position but is held by the track out of operative position. At a transfer point, a portion of the track is cut away to permit the second dog to move to operative carrier transferring position. Such a system effectively provides for transfer of the carrier without any change in elevation of the power and free tracks. However, where the pushers on the conveyor chain are spaced apart greater distances or where the system includes transfer across short and long distances, a loss of efficiency in transfer may occur either because of the time delay in awaiting a pusher on the conveyor chain or minimum length between the first and second dogs.
It has also been heretofore suggested to provide a third dog on the carrier which has the same configuration as the second dog and is normally held out of operative position by the track but can be brought to operative position to transfer the carrier across a greater distance.
Among the objects of the present invention are to provide a power and free conveyor system wherein a carrier is transferred from one predetermined path to another by pushing across a transfer zone in a minimum period of time and wherein such system is achieved with minimum cost and maintenance; and wherein selective transfer of the carrier can be achieved over short and long distances as desired.
SUMMARY OF THE INVENTION
In accordance with the invention, a third dog is provided in longitudinally spaced relation to the first and second dogs and is normally urged to an operative carrier pushing position but is held by the track out of operative position. The second and third dogs include cam projections thereon that engage portions of the track which hold the second and third dogs out of operative position. The cam projection on the second dog extends oppositely to the cam projection on the third dog. As the carrier moves to a transfer zone one or the other of the second and third dogs is successively moved to operative position. By providing selectively operable second and third dogs, it is possible to transfer across short or long distances thereby accommodating various systems wherein the transfer varies between short and long distances.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary side elevational view of a conveyor system embodying the invention.
FIG. 2 is a fragmentary elevational view on an enlarged scale of a portion of the system shown in FIG. 1.
FIG. 3 is a fragmentary sectional view taken along the line 3--3 in FIG. 2.
FIG. 4 is a fragmentary side elevational view similar to FIG. 2 showing the parts in a different operative position.
FIG. 5 is a fragmentary view similar to FIGS. 2 and 4 showing the parts in different operative position.
FIG. 6 is a fragmentary sectional view taken along the line 6--6 in FIG. 2.
FIG. 7 is a fragmentary plan view of the system.
FIG. 8 is a fragmentary plan view of a modified form of conveyor system.
FIG. 9 is a fragmentary plan view of a further modified form of conveyor system.
FIG. 10 is a fragmentary plan view of another modified form of conveyor system.
FIG. 11 is a fragmentary plan view of a further modified form of conveyor system.
FIG. 12 is a fragmentary plan view of a further modified form of conveyor system.
DESCRIPTION
Referring to FIG. 1, the invention relates to a conveyor system wherein a power chain is adapted to selectively engage trolleys and move them in predetermined paths. The trolley motion is from right to left. Specifically, conveyor chain 10 is supported by chain trolleys 11 for movement along a track 12. The chain 10 includes longitudinally spaced pushers 13 that are adapted to engage carriers, as presently described, to move them. As shown, a carrier 15 may comprise longitudinally spaced trolleys 16,17,18 pivotally interconnected by tie bars 19,20. The trolleys include wheels 22 that engage the lower flanges of spaced inwardly facing C-shaped channels of track 21 (FIGS. 3 and 6). The foremost trolley 16 includes an actuating lever 23 that is operatively connected to a pusher dog 24 so that when lever 23 engages an obstacle or a projection 25 on the rear trolley 18 of a preceding carrier, the lever 23 is swung clockwise as viewed in FIG. 1 to lower the pusher dog 24 out of the path of a pusher 13. Such an arrangement is known as an accumulating conveyor system. The foremost trolley 16 further includes a pivoted holdback dog 26 in accordance with conventional practice.
As further shown in FIG. 7, the conveyor system is shown in connection with an exit switch which includes a second track 27 that extends at an angle from the track 21 and a switch tongue 28 that is operated to selectively guide the carrier 15 into the second track 27. The switch tongue 28 is controlled by signal devices such as are well known in the art, for example, as shown in the U.S. Pat. No. 2,868,139. A second power chain 29 is provided in overlying relation to a portion of the track 27 and is adapted to pick up the carrier and move it along the track 27.
Referring more specifically to FIG. 1, succeeding trolleys 17, 18 of the carrier 15 are each provided with a pivoted pusher dog 30,31 respectively, each of which is pivoted intermediate to its ends to its respective trolley and counterweighted so that the pusher dog end 30,31 thereof is urged normally to operative pushing position. However, the width of each pusher dog 30,31 is such that the top edges of projections 30a,31b respectively, normally engage the underside of the upper horizontal flanges 21a,21b of the track so that the pusher dogs 30,31 are normally in the position shown in FIG. 4, namely, out of the path of pushers 13. Projection 31b extends beneath the flange 21b while projection 30a extends in the opposite direction beneath the flange 21a. As shown in FIG. 7, in the case of a transfer of the carrier from the track 21 to the track 27 by positioning of the switch tongue 28, a portion of the flange 21a is cut away as at 34a, to permit the pusher dog to swing counterclockwise under the action of the counterweight to the position shown in FIGS. 2 and 5 and thereby be in position for engagement with a pusher 13 which will push the carrier 15 through the switching or transfer area into position for engagement of the leading power dog 24 with the pusher of a secondary chain 29 along second track 27.
When the switch tongue 28 is actuated to divert the carrier, the pusher 13 which is in engagement with the pusher dog 24 will disengage from the pusher dog 24 as the foremost trolley 16 of carrier 15 is diverted to the track 27. The carrier 15 will then be momentarily stopped. However, by this time, the pusher dog 30 will have been moved upwardly through track opening 34a so that the succeeding pusher 13 of the power chain 10 will engage and cause the carrier 15 to be moved further along the track 27 sufficiently to permit dog 24 to be picked up by a pusher of the second power chain 29. As the carrier is moved along track 27, the upper flange 21a of track 27 is provided with a cam down opening 35a which will engage projection 30a of the pusher dog 30 to pivot it down out of the path of the pusher of chain 29. In order to cause downward movement of the pusher dog 30a, a portion 35a of the flange 21a is bent upwardly. Through this transfer, dog 31 is held down by flange 21b out of operative position.
Referring to FIG. 8, there is shown an exit system where the transfer is across a greater gap than in FIG. 7. In FIG. 8 when the switch tongue 28 is actuated to divert the carrier, the pusher 13 which is in engagement with pusher dog 24 will disengage from the pusher dog 24 as the foremost trolley 16 of the carrier 15 is diverted to the track 27'. The carrier 15 will then be momentarily stopped. However, by this time, the pusher dog 31 will have been moved upwardly through track opening 34b so that a succeeding pusher 13 of the power chain 10' will engage pusher dog 31 and cause the carrier 15 to be moved further along the track 27' sufficiently to permit dog 24 to be picked up by a pusher of the second power chain 29'. As the carrier is moved along track 27', the upper flange 21b of track 27' is provided with a cam down opening 35b which will engage projection 31a of the pusher dog 31 to pivot it down out of the path of the pusher of chain 29'. In order to cause downward movement of the pusher dog 31, a portion 35b of the flange 21b is bent upwardly. Through this transfer dog 30 is held down by flange 21a in inoperative position.
More specifically, as shown in FIGS. 7 and 8, the dog 30 can be used for a short distance of transfer (FIG. 7) while dog 31 can be used for a long distance of transfer as when the chain 29' is a greater distance from chain 10' (FIG. 8).
Cam down openings 35a, 35b may normally be both provided, as shown. Although not used to effect transfer to: (1) simplify design and construction; and (2) return dog 30,31 to inoperative position which may have not been used to effect transfer but was moved to the operative position while passing through the switch area.
It can thus be seen that in accordance with the invention, a third dog is provided in longitudinally spaced relation to the first and second dogs and is normally urged to an operative carrier pushing position but is held by the track out of operative position. As the carrier moves to a transfer zone, one or the other of the second and third dogs is successively moved to operative position. As a result, it is possible to transfer selectively across a greater or shorter distance thereby accommodating various systems wherein the transfer varies between short and long distances.
In both forms of FIGS. 7 and 8, a carrier which is not switched off is pushed all the way through the switching area by engagement of its front dog 24 with a dog 13 of the power chain so that the trailing dogs 30,31 move through this area without being in contact with a dog 13. As a result, dogs 30,31 are free to swing upward to their operating position at the start of the track flange cut-outs 34a,34b and are forced down again at 35a,35b.
In a track configuration as in FIGS. 7 and 8, but with the carriers and chains moving in the opposite direction as shown in FIGS. 9 and 10, a carrier would move either from left to right on the straight tracks 21 or would enter this track from track 27. No cut-outs 34a,34b are needed in tracks 21 in this case, but only in track 27 to move dog 30,31 to operative position to enable a pusher dog 13 on power chain 29 to advance the carrier far enough to place the front dog 24 into the path of the chain 10 and pusher dogs 13. Cam down openings 35a, 35b will normally be located on track 21 to return dog 30,31 to inoperative position after transfer.
More specifically, referring to FIG. 9, wherein the carrier is to be moved across the shorter gap from track 27, the dog 30 is permitted to move upwardly through opening 34a' into the path of a succeeding pusher of chain 29 which will, in turn, push the carrier to bring dog 24 into the path of a pusher on chain 13 moving along track 21. Further movement of the carrier along track 21 will bring the projection on pusher dog 30 into engagement with cam down portion 35a' to pivot dog 30 downwardly.
Similarly, where the gap to be traversed is greater as in FIG. 10, the cut out portion 34b' permits dog 31 to pivot upwardly so that a succeeding pusher on chain 29 will push the carrier to bring its dog 24 into the path of a pusher 13' on the chain moving along track 21'. As the carrier is moved along track 21', cam down portion 35b' will pivot dog 31 downwardly.
Throughout the portion of the system wherein the transfer is achieved, the relative positions vertically of the power track 12 and carrier tracks 21,27 remain constant and are not changed.
In another type of system, the carrier is moved from one path toward the other and then is pushed through the transfer area to the second. Specifically, as shown in FIG. 11, the carrier is moved along a track 40 in a portion between spaced power conveyors 41,42, each of which has pushers 43,44. As the conveyor 41 moves over its sprocket 45, the pusher 43 thereon which is in engagement with the pusher dog 24 of the carrier will disengage from the pusher dog 24 and will be momentarily stopped. At this point, cut-away portion 46a, along the track 40 will have permitted the second pusher dog 30 of the carrier to pivot upwardly into the path of a succeeding pusher 43 which then pushes the carrier across the gap between the conveyors 41,42 bringing the leading pusher dog 24 into a position of engagement with a pusher dog 44 of the succeeding conveyor 42. As the carrier is pulled across the space by pusher 44 between the conveyors 41,42, the cam projection 30a on the second pusher dog 30 engages the cam down portion 47a which pivots dog 30 downwardly returning it to an inoperative position.
A greater gap to be traversed than FIG. 11, is shown in FIG. 12. This arrangement is such that the third dog 31 is permitted to pivot upwardly. Specifically, the carrier is adapted to move along a track 40' in a portion between spaced power conveyors 41',42', each of which has pushers 43', 44'. As the conveyor 41' moves over its sprocket 45', the pusher 43' thereon which is in engagement with the pusher dog 24 of the carrier will disengage from the pusher dog 24 and will be momentarily stopped. At this point, cut-away portion 46b along the track 40' will have permitted third pusher dog 31 of the carrier to pivot upwardly into the path of a succeeding pusher 43' which then pushes the carrier across the gap between the conveyors 41', 42' bringing the leading pusher dog 24 into a position of engagement with a pusher 44' of the succeeding conveyor 42'. As the carrier is pulled across the space by pusher 44' between the conveyors 41',42', the cam projection 31b on the third pusher dog 31 engages the cam down portion 47b which pivots dog 31 downwardly returning it to an inoperative position.
Thus, the dog 30 can be used to transfer across a short distance (FIG. 11) and the dog 31 can be used to transfer across a long distance (FIG. 12).
In addition to selectively permitting either dogs 30 or 31 to move upwardly for transfer, the system can be operated also by moving the dogs upwardly simultaneously or sequentially as may be required.
For example, where it is desired to minimize the number of pushers on the conveyor, it might be desirable to cut away both flanges of the track at appropriate points to permit both dogs 30,31 to be simultaneously moved upwardly. In this manner, the pusher 13 which is nearest to one of the dogs 30,31 will move the carrier forwardly. Thus, the number of pushers on the conveyor chain can be minimized thereby reducing costs and still retaining a minimum lapse of time in transfer.
The dogs might also be operatively positioned sequentially such as in a situation wherein a long transfer is desired. The first dog 30 is permitted to move upwardly to permit a succeeding pusher 13 to move the carrier partway and then a second dog 31 is permitted to move upwardly to permit a succeeding pusher 13 to move the carrier a further distance. Such an arrangement might also be advantageous where it is desired to depress the first-mentioned dog 30 for clearance or other purposes. | A conveyor system including a first load supporting track and a second load supporting track with an intermediate transfer portion. A powered conveyor is provided in association with each of the first and second tracks. A plurality of carriers are provided. Each of the carriers has a first dog that is in position for normal engagement with the pusher member of the conveyor and longitudinally spaced second and third dogs that are normally urged to an operative carrier pushing position but are held by the track out of operative position. The second and third dogs include cam projections thereon that engage portions of the track which hold the second and third dogs out of operative position. The cam projection on the second dog extends oppositely to the cam projection on the third dog. At a transfer point, an appropriate portion of the track is cut away to permit either the second or third dogs to move to operative carrier transferring position. | big_patent |
CLAIM OF PRIORITY
Priority is claimed based on Provisional Application Serial No. 60/042,080 filed Mar. 28, 1997.
DESCRIPTION OF RELATED ART
Prior art rail car truck bowl liners come in several categories. Early liners were made of hard metal alloys such as manganese steel, however these need to be lubricated periodically, which is burdensome and expensive. Certain recent liners are composed of an ultra high molecular weight polymer, which eliminated the need for lubrication. However, such liners needed to have separate grounding apparatus added since the liner is nonconductive.
A third category is a hybridized composite liner that utilizes metal reinforcement in a polymer matrix. The metal provides some conductivity, but not necessarily at a desired level. Finally, a molded polyurethane bowl liner using entrained carbon fiber is known, but the proportions are specifically different and a for the purpose of ablation of the carbon fiber as the polyurethane wears, to provide lubrication. These properties are different from, and are specifically avoided in, the present invention which relies primarily on the self-lubricating properties of the polyethylene.
SUMMARY OF THE INVENTION
This invention relates to a grounding product for railroad car center plate assembly bowl liners of the all polymeric type, and more particularly providing for effective grounding without the use of conductive plates, clips or shunts attached to the liner, as disclosed in Wulff U.S. Pat. No. 4,241,667, granted on Dec. 30, 1980. The liner material used herein has similar mechanical properties to the liner as disclosed in Chierici and Murphy U.S. Pat. No. 4,075,951, granted on Feb. 28, 1978, but has improved electrical properties. The disclosures in Wulff U.S. Pat. No. 4,241,667 and Chierici and Murphy U.S. Pat. No. 4,075,951, are incorporated by reference.
Railroad cars are commonly in the form of a body resting on and swivelly connected to a pair of trucks adjacent each end of the car. The swivel connection involved in each truck is generally formed by the car body bolster center plate resting on the truck bolster bowl, with these parts being pivotally connected by a center pin assembly. The reason for the swivel connection is to accommodate motion such as occurs during the car rounding turns and shakes imposed on the railroad car such as caused by track discontinuities while doing minimal damage to the car itself and cargo. Such cars commonly had a manganese steel liner captured between the center plate and the truck bolster bowl. A disadvantage of the manganese steel liner between the two components that has been recognized is that frequent lubrication is necessary. If a car with this old style all metal liner went unlubricated, the swiveling motion would be inhibited and could possibly cause a derailment. At a minimum, excess wear would be caused to the car center plate, the truck center bowl, or both.
The Chierici and Murphy patent referred to above discloses a special truck bolster bowl liner that was devised to replace the conventional and troublesome manganese steel liner. The Chierici and Murphy liner is in the form of a bowl shaped member or body formed from an ultra high molecular weight polymer of dry self lubricating characteristics. An ultra high molecular weight polyethylene (UHMW-PE) is preferred, and the bowl member is shaped to define a floor portion and an upstanding side wall portion which is in circumambient relation about the bowl liner floor portion.
The bowl liner side wall is proportioned to space the car body bolster center plate from the truck bolster bowl side wall, about the circumference of these components, and hold the body bolster center plate in such spaced relation against end of car impacts, whereby such impact forces transmitted between the car body bolster center plate and the truck bolster bowl side wall are spread over 180 degrees of the bolster components involved thereby avoiding overstressing of these components. In the flat horizontal liner, these side loads are borne by a separate liner, usually of steel, held in place in the truck bolster bowl. The problem with the previously disclosed liners are that they are nonconductive, necessitating the addition of some grounding apparatus such as that disclosed in the Wulff patent.
Several alternative embodiments are also present to this bowl liner configuration, which can be adapted to the static dissipative characteristics of the instant invention. One option is to use a UHMW-PE flat horizontal disk formed liner to bear the car bolster center plate. In this embodiment, sidewards loads on the bolster assembly are borne by a metal liner or wear ring welded to the truck bolster, filling the space between the center plate and truck bolster bowl. This embodiment is referred to as a flat horizontal liner. In addition, additional configurations for a top edge seal on an all plastic bolster bowl liner are also possible.
The Chierici and Murphy all plastic bowl liner of said patent establishes two slip surfaces in the center plate assembly, one on either side of the bowl liner, that insures adequate truck swiveling action even under severe operating contingencies, and further provides for a wear resisting resurfacing of the bolster surfaces engaged by the bowl liner whereby the center plate assemblies involved become effectively resistant against further wear, as disclosed in said patent.
The American Association of Railroads requires that railroad car center plate assemblies be arranged so that the body bolster center plate will be sufficiently grounded to the truck bolster bowl. Standards for static electricity conductivity, in other industries such as ANSI/NFPA77 make it desirable to form and arrange the center plate assembly so that it will offer no more than about 1×10 6 ohms (100 Kohms) resistance to electrical current flow therethrough. The invention here exceeds the NFPA standards by an order of magnitude, there being no quantitative AAR standard. The purpose is to assure that any electric charge that might tend to build up in the car body or be induced in same will be discharged through the car trucks to the track rails.
Where the car body center plate acts directly on the bolster bowl, or where the commonly employed manganese steel liner is employed between the two, the metal to metal contact involved has been considered adequate to meet static dissipation standards. While the grounding standard is met, there remains the wear and damage problem in the center plate assembly area of the car.
Railroad cars having their center plate assemblies equipped in accordance with said Chierici and Murphy patent have the benefits described in said patent. However, as the polymeric material from which the liner is formed is electrically insulating or dielectric in nature, the car body bolster center plate and the truck bolster bowl have been considered to require grounding therebetween, at least for certain types of cars, even though the bolster center pin may provide a measure of electrical conductivity to the trucks.
Cars using a liner as disclosed in Chierici et al also had to incorporate grounding apparatus, as disclosed in the Wulff patent. Grounding methods such as the one disclosed in Wulff all use some form of conductive shunt clip and metal rivets to provide an artificial path between the car body center plate to the truck bolster bowl. These methods are disadvantageous in that they are subject to wear and tear, and after extended use the conductors can be recessed below the surface area of the liner to a point where they have a less effective contact area.
As the grounding clip or shunt exists for the purpose of providing unlubricated metal to metal contact, it also provides increased friction over that provided by the Chierici et al all UHMW-PE liner. The previous grounding method is also disadvantageous in that periodic inspection of the grounding clips may be necessary, requiring costly disassembly of the center plate assembly. Wear of the grounding clip, present for the purpose of providing metal to metal contact, can result in the frictional wearing of the clip sufficient that it becomes dismembered and therefore the electrical contact is, in any event, broken. There are also potential difficulties in the fact that the shunt or clip provides for contact in a relatively small portion of the total bearing surface. As a car rolls or pitches there is the risk of intermittent contact if the orientation of the shunt is not roughly perpendicular to the axis of the aforesaid pitching or rolling movement.
The present invention is concerned with providing a liner with all the benefits as disclosed in the Chierici et al patent and in addition being conductive, thereby eliminating the need for any additional grounding apparatus.
The liner is composed of a base ultra high molecular weight polyethylene (UHMW-PE) material with a conductive material additive. The preferred composition is UHMW-PE specially mixed with 2.0% carbon black. The conductive material, such as carbon black sold on the market as Monarch 700 anti-static agent, can be added as a particulate to UHMW-PE in particulate or powder form and then the mixture heated under mold pressure for thermoforming. With other plastics, or other molding or forming methods, the conductive material may be added as described above with UHMW-PE or possibly mixed with a plastic in its solid pelletized form or the conductive carbon black material may be added while the plastic is liquified for thermoforming. It is also possible that an appropriate thermosetting plastic could be used as the self-lubricating matrix with conductive material mixed therein and the liquified thermosetting plastic cured to form a liner having the requisite mechanical and electrical properties.
It will be noted that other plastics can be formed as ultra high molecular weight material. At the present time, polyethylene is preferred both for performance and economic reasons. However, other polymers would prove to be suitable and applicants do not wish to be limited only to the invention as claimed.
This improved liner still has all of the same properties that make the liner as disclosed in Chierici et al so beneficial, with the additional benefit that the liner is now conductive. Any electrical charge built up in the car body will be discharged through the liner into the car trucks and discharged into the track rails.
BRIEF DESCRIPTION OF THE DRAWINGS
The following drawings, in which like reference characters indicate like parts, are illustrative of embodiments of the invention and are not intended to limit the scope of the invention in any manner whatsoever, as encompassed by the claims forming a part hereof.
FIG. 1 is a diagrammatic transverse cross-sectional view through a railroad car body underframe at one of its body bolsters, showing some parts of same and the supporting truck bolster in elevation, with the truck wheels being shown in phantom and the truck side frames omitted for ease of illustration;
FIG. 2 is a fragmental vertical cross-sectional view through the center plate assembly shown in FIG. 1 illustrating one arrangement of the center plate components and self lubricating liner in accordance with this invention;
FIG. 3 is a perspective view of the liner;
FIG. 4 is a fragmental vertical sectional view of the liner of FIG. 3 showing same as separated from the center plate assembly.
FIG. 5 is a top plan view of the flat horizontal embodiment of the static dissipative liner.
FIG. 6 is a fragmental vertical sectional view of the flat horizontal embodiment of the static dissipative liner of FIG. 5.
FIG. 7 is a top plan view of an alternative embodiment of the bowl liner in accordance with this invention.
FIG. 8 is a fragmental vertical sectional view of the liner of FIG. 7.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Reference numeral 10 generally indicates a railroad car in diagrammatically illustrated form and shown to comprise car body underframe 12 having a car body bolster 14 resting on and swivelly connected to truck bolster 16 of railroad car truck 18. The truck 18 and its bolster 16 are of any conventional type and thus are only diagrammatically illustrated.
The connection of the car body bolster 14 to the truck bolster 16 is effected utilizing center plate assembly 20, which in accordance with the present invention comprises truck bolster bowl 22 (see FIG. 2) that is integral with the bolster 16 and defines upstanding side wall 24 and floor wall 26, in which is received body bolster center plate 28 that in the form shown is integral with center filler 30 suitably fixed to the underframe center sill 32 for forming the "center plate" of body bolster 14. As is conventional, the truck bolster bowl floor 26 and center plate 28 are apertured as indicated at 34 and 36, respectively, to receive the conventional kingpin 37 (only a fragment is shown) that swivelably connects these components together. Bowl 22 and center plate 28 are of standard shaping, and thus bowl wall 24 is shown to include the usual recessed edge 35 that normally functions to retain the conventional manganese steel liner in the bowl 22.
The body bolster center plate 28 comprises an upstanding side wall 40 that is integral with planar wall portion 42 that seats within the bolster bowl 22. As is well known in the art, the center plate 28 may be a separate component, or part of a separate component suitably fixed to the center sill 32 and/or the body bolster 14, or plate 28 may be an integral part of bolster 14 or parts of same.
In accordance with the present invention, a liner 44 of special characteristics is interposed between the body bolster center plate 28 and the side wall 24 and floor 26 of the bolster bowl. Liner 44 is formed of dry self lubricating material to eliminate the need for applying separate lubricating materials to the center plate assembly 20, which in turn permits the center plate and bowl area of the car to be free of wet type lubricants that are customarily used for this lubrication, but also accumulate wear inducing foreign matter.
In the form of FIGS. 2-4, the liner 44 is of dished, bowl like configuration, and comprises a floor or disc portion 46 of rounded configuration that is apertured at 48 to receive the aforementioned conventional kingpin. The liner 44 about the outer margin 50 of its floor disc portion 46 includes upstanding side wall 52 that is in circumambient relation thereabout and that is continuous and uninterrupted about its circumference, as indicated in FIG. 3.
The liner 44, in accordance with the invention, is defined by a high density polymer of dry self lubricating characteristics that is pliable but non-stretchable and is thus free from distending or stretching characteristics and that is sufficiently compaction resistant to resist any substantial compaction under compressive forces up to its elastic limit, and has a high degree of elastic memory for full return to original shape after being stressed, up to its elastic limit. The liner is also conductive, made from ultra high molecular weight polyethylene specially mixed with a conductive material such as 2% carbon black. This carbon black is known on the market as Monarch 700 anti-static agent.
While the use of carbon black mixed with plastics is known, this combination of materials has not heretofore been found useful in the unique application of a self-lubricating rail car center bowl liner. A combination of mechanical, chemical and electrical traits need to be optimized for a center bowl liner to be designed to meet all these competing needs. A standard carbon black mixture with carbon black mixed with ultra high molecular weight polyethylene is 1% carbon black. The particulate carbon black 54 is shown in FIG., 4. The distribution is shown here diagrammatically and the distribution is not to be considered to be shown quantitatively in this Figure. As is discussed, the carbon black particles 54 are in a proportion of about 2% to the UHMW-PE matrix material into which particles 54 are mixed for substantially uniform distribution. It is also possible that other particulates may be suitably mixable in the proportions and having the properties claimed herein.
It will be noted that rail car center bowls are designed to withstand loads imposed by cars having a mass bearing on each center bowl on the order of 25,000 to 122,000 pounds depending on the specific cars' contents and construction standards. These loads are imposed by both static and dynamic forces although the dynamic forces can sometimes exceed the 122,000 lbs described above. It is critical to maximize the properties of the liner material in both the chemical and mechanical areas to preserve the self lubricating feature as well as wear resistance and resistance to compression, deterioration and disintegration. Accordingly, standard carbon black UHMW-PE mixtures may have been made for other applications, such as coloration of plastic, at the 1% carbon black percentage.
It is also expected that the load placed on the liner by the weight carried in the car has beneficial effects on the properties of the liner with the disclosed proportion of entrained carbon black conductive material in that the liner is compressed under load. As the distance between the particles decreases, as at high tare weights, then conductivity increases as a static charge has a smaller distance to travel. Thus, there would be an increase in conductivity in a car, such as a railroad tank car, which is fully loaded, when compared to an unloaded car, which in this instance will correspond to the time for the most desirable increase in conductivity, as the car is being loaded.
Another advantage provided by the instant invention, using the carbon black in the proportion described herein is that as described in the Chierici et al patent, there is a polishing and wear hardening that occurs using the all UHMW-PE liner. Because the carbon black conductive material is uniformly contained with in the UHMW-PE matrix, as that matrix undergoes ablation by this wear process, new carbon black particulates are exposed as the matrix wears. Thus, while as explained below, the walls of the liner are arranged to minimize contamination of the self-lubricating surfaces of the liner from the exterior, to the extent contamination occurs, there would be more carbon black material exposed as the UHMW-PE matrix wears or ablates.
Including too much carbon black mixed with the plastic interferes with the self-lubricating properties of the UHMW-PE. In the Rudibaugh U.S. Pat. No. 5,443,015 prior art patent, 5% carbon black was mixed with castable thermoset urethane for the purpose (the opposite of that desired here) of ablating a sufficient amount of carbon so that the lubricating properties of the carbon will be effective in lubricating the urethane wear plate. Because the instant invention relies on the advantages of the self-lubricating UHMW-PE material, the 5% limit for the urethane wear plates provides substantiation for the upper limit of applicants' range of carbon black. It is not, however, an absolute upper limit because of the different properties of the urethane and self-lubricating UHMW-PE.
The full bowl liner embodiments of the invention contemplate that the liner side wall 52 and floor portion 46 are proportioned to fully fill the space between the truck bolster bowl and the body bolster center plate that would not permit any lost motion movement of the center plate 28 relative to bowl 22 in the plane of these components. Thus, the side wall 52 of liner 44 is proportioned to fill the space between the bowl side wall 24 and the body bolster center plate side wall 40 to the extent that bowl wall 24 holds the liner 44 against movement in the plane of bowl 22, and liner 44 holds center plate 28 against movement in the same plane. Of course, the liner 44 is not closed across the aperture 48 so as to permit application of a conventional kingpin, and, as indicated in FIG. 2, liner 44 need not have the inner surfacing along floor 46 or wall 52 fully complement the normal tapered external surfacing of center plate 28 at the lower portion of its wall 40. It is only necessary that the liner wall 52 have a thickness such that at the upper level of bowl wall 24, just below recess 35, the liner wall 52 fully fills the space between center plate wall 40 and bowl wall 24, so as to preclude movement of the center plate 28, relative to bowl 22, in the plane of center plate assembly 20.
In FIGS. 5 and 6, the preferred flat horizontal disk 146 is provided with aperture 148 through which kingpin 36 (FIG. 1) and related assemblies may pass. Outer or peripheral edge 150 is sized such that disk 146 will fit inside a metal collar style wear liner fitted to a truck bolster, in the manner described in the background of the invention and as is known in the field. In the sectional view FIG. 6, the flat configuration of disk 146 is shown as is wall 152 which defines aperture 148.
FIGS. 7 and 8 show another approach, using a full bowl liner 244 having a floor or disk portion 246 with kingpin aperture 248 and upstanding wall 252 terminating in flange 264. There are mechanical and electrical conductivity improvements in this embodiment. Disk portion 246 has two major subdivisions, a conductive ring 270 which has the disclosed 2% to about 5% conductive material molded or entrained in the plastic and an outer ring 272 composed of the structural self-lubricating plastic, preferably UHMW-PE. This can be molded using known plastic molding techniques such as compression molding. Preferably known plastic molding techniques can be used to partially mold the outer ring 272, wall 252 and flange 264 as a unit and then placing the solid particulate plastic and conductive material mix in position to form ring 270 and then reheating the entire unit under pressure to form a substantially unitary disk portion 244 simply with a concentration of conductive material in a preselected location.
Flange 264 includes a horizontal portion 274 with an internally conical bevel 276 which will fit closely against the car bolster as shown in FIG. 1. Exterior radiused ring portion 278 provides for better support of flange 264 and potentially improved sealing against the truck bolster.
The mechanical features of the UHMW-PE bowl liner include the configuration to fit in the space between the truck bolster bowl 22 and the body bolster center plate 28 to limit lost motion movement of the center plate 28 relative to wall 52 of bowl 22 in the plane of these components and also to provide vertical support for center plate 28 in bowl 22. Liner 44's preferred UHMW-PE material resists distension or stretching, and any substantial compaction due to compression (up to its elastic limit). Liner 44 holds these components firmly spaced apart and against forces, and especially impact forces. The UHMW-PE material disperses loads, is itself highly resilient to such loads, particularly when captured between main load bearing components like center plate 28 within bowl 22 and has the beneficial self-lubricating properties as described in greater detail in the cited patents which are incorporated by reference.
The configuration of liner 44 is much like the older steel liner. As disclosed in the earlier patents, liner wall 52 does not seat in any way on the top surfacing 60 of the bowl 22 or its recess 35, rising straight out of the bowl interior for firm engagement with the neck portion 62 of center plate wall 40, 360 degrees thereabout. This effects a seal about the center plate neck portion 62 that precludes entry of foreign material between the liner 44 and center plate 28.
Flange 64 extends outwardly from bevelled portion 66, itself at the top of wall 52 at an approximately 90 degree angle. This provides a level of line sealing contact with the center plate neck portion 62. The precise dimensions and proportions can be adapted to particular center bowl needs. This configuration, building on the teachings of Chierici and Murphy is not required in order to practice the invention according to the teachings herein.
Liner 44 freely carried in its captured location between bowl 28 and center plate 28. This embodiment forms two slip surfaces with the center plate assembly 20 to insure the needed swivelling action of the car trucks 18 with respect to the car body 12.
It is expected that the configuration shown in FIG. 7 and FIG. 8 may be preferred over this older configuration.
The flat disk of FIGS. 5 and 6 could also be made pursuant to either the uniform distribution of conductive material embodiment or with a more concentrated inner conductive ring, as described above. Of course the flat disk version of FIGS. 5 and 6 provides the flat slip surfaces in a car that has a partial metal liner.
The primary slip surface is between the upper surface 72 of the liner 44 and the body bolster center plate 28's lower surface or planar wall 42. Liner 44 also forms a secondary contingency slip surface 70, the lower surface of the liner 44 and the truck bolster floor 26.
The liner 44, 146, in accordance with this invention, can both meet the from 0.15 to 0.20 coefficient of friction of the all UHMW-PE liner (Chierici et al and Murphy) relative to the surfaces of the body bolster center plate 28 and bolster bowl 22 and also meet the electrical conductivity standards of 1×10 5 ohms (100 Kohms), although coefficient of friction under load can temporarily be higher. As such, it is an improvement over both the all UHMW-PE liner, which has a high resistance, and the clip or shunt grounded version (Wulff) which has an inconsistent coefficient of friction due to the interference of the shunt or clip with the uniform contact of surfaces 70, 72.
As many and varied modifications of the subject matter of this invention will become apparent to those skilled in the art from the detailed description given hereinabove, it will be understood that the present invention is limited only as provided in the claims appended hereto. | A conductive center bearing liner for railroad car center plate assemblies comprising a bowl shaped or flat round horizontal member formed from a cross-linked ultra high molecular weight polymer specially mixed with a conductive material shaped to define a floor portion and alternative embodiments with an upstanding side wall. Another embodiment concentrates the conductive material in a selected sector of the disk portion of the liner. The conductive liner eliminates the need to incorporate special apparatus to ground the car body center plate to the truck bolster bowl. This grounding method eliminates the wear and erosion that occurs by grounding using conventional methods. | big_patent |
BACKGROUND OF THE INVENTION AND PRIOR ART
This invention deals with a valve used for controlling bulk dispensing of viscous substances such as sauces, salad dressings, catsup, mustard or various other substances, especially where it is desirable to have a valve that can be operated with one hand while the other hand, for example, is holding the receiving vessel, such as in fast-food restaurants, etc. These substances are commonly packaged in flexible bags or pouches which may or may not be contained in boxes. The prior art provides two main types of valves for this purpose. One is the rotatable cylindrical tube type which cannot be disassembled for cleaning, and this allows for residue accumulation, and cannot be tilted in dispensing so that all the contents of the bag is discharged. The other is the ball-type which also cannot be disassembled for cleaning and allows for residue accumulation.
SUMMARY OF INVENTION
The present invention provides a gate valve which is to be mounted on the spout of a bag or pouch. It includes a tubular sleeve adapted to be inserted into the spout of a bag and has a dispensing package extending therethrough. At the outlet end of this passage is a guide extending at a right angle to the axis thereof and this slide carries a receprocable gate. Cooperating lugs are provided on the gate and guide so that by engagement thereof with the fingers of one hand, the gate can be reciprocated to position it over the discharge or dispensing outlet. The gate and guide are curved complementally transversely so that the gate is drawn into sealing engagement with the outlet as it moves over it and an effective seal will result, however, when the gate is completely opened, there will be no obstruction to flow from the outlet but when it moves towards closed position variable flow will occur and ultimately complete cut-off.
BRIEF DESCRIPTION OF THE DRAWINGS
The best mode contemplated in carrying out this invention is illustrated in the accompanying drawings in which:
FIG. 1 is a perspective view of a valve embodying this invention;
FIG. 2 is a front view of the valve with the gate closed;
FIG. 3 is a plan view of the valve;
FIG. 4 is a side elevational view of the valve;
FIG. 5 is a bottom view of the valve;
FIG. 6 is a sectional view taken along line 6--6 of FIG. 4;
FIG. 7 is a view similar to FIG. 2 but with the gate opened;
FIG. 8 is a view similar to FIG. 6 but showing a different sealing lip around the discharge outlet;
FIG. 9 is a top plan view showing the valve on the spout of a bag which is supported in a dispenser;
FIG. 10 is a side elevational view of the assembly shown in FIG. 9;
FIG. 11 is an enlarged sectional view of the bag spout and valve carried thereby in the dispenser;
FIG. 12 is a schematic view showing how the fingers are used in opening the valve; and
FIG. 13 is a similar view showing the closing of the valve.
DETAILED DESCRIPTION OF THE INVENTION
With specific reference to the drawings, the valve assembly of this invention is illustrated generally by the numeral 15 and is shown removably mounted on the spout S of the bag B in FIGS. 9 to 13, the bag being disposed in the housing of a dispenser D of a common type. The bag may contain a viscous substance, such as salad dressing, sauce, mustard, catsup, etc. in bulk, which it is desired to dispense by using one hand only, having the other hand free, for example, to hold a receiving vessel.
The valve 15 itself comprises a spout insert mounting sleeve 16 which is slightly tapered so it will slip into and gradually tightly frictionally engage the interior of the spout S. It is provided with a plurality of axially-spaced annular sealing ribs 17 on its exterior surface for engaging the interior surface of the spout. It is further provided with a passage 18 extending axially therethrough having a discharge outlet with a substantially annular sealing edge extremity 20 extending therearound. The interior surface of the sleeve also has adjacent its inlet end 21 an annular stop shoulder 22. The annular outer or discharge edge 20 of the sleeve 16 is curved transversely relative to the axis of the sleeve in a manner and for a purpose to be described.
At the outer or discharge end of the sleeve 16, a gate valve guide member 24 is formed integral with the sleeve and extends radially outwardly from the sleeve. It will be disposed to guide the gate valve member 25 during its reciprocal movement relative to the discharge or dispensing outlet 20 of the sleeve. The guide member 24 is in the form of a transversely-curved plate 24a which is formed integrally with and disposed in radially-extending relationship to the sleeve 16 at the outer or discharge end thereof. Assuming the valve assembly is in the position shown in the drawings, the guide 24 will be upstanding from the sleeve 16 with the vertical centerline thereof disposed at a right angle to the axis of the sleeve 16. The curve of the guide plate 24a will be transverse of the centerline thereof, and the axis of the sleeve 16 will be radial relative to that curvature. It will be noted that the guide plate 24a will extend down below the outlet opening and that the sealing edge 20 will be substantially flush with the adjacent outer or front surface thereof. A sharp sealing edge 20 is formed by providing the surrounding groove 20a where the end of the sleeve 16 joins the guide plate 24a. The structure of FIG. 8 is the same as that shown in FIG. 6 except that there is a sharp sealing lip extremity 20b which extends slightly beyond the surrounding face of the guide plate 24a. The guide 24 is provided at its end opposite the sleeve 16, or its upper end, with a transverse wall or lug 26 which is reinforced by a gusset 27. Rearwardly-projecting resiliently yieldable stop lugs 28 are provided on the lower edge and at each side of the guide plate 24a.
The gate valve member 25 itself comprises a plate 25a which is curved transversely complementally to the curvature of the guide plate 24a. This plate has, at each of its straight side edges, flanges of channel-formations which produce opposed guide-receiving formations 30 that provide inwardly-opening grooves for receiving the opposite side edges of the guide plate 24a. The guide channels 30 will be precisely fitted onto the edges of the plate 24a so as to draw the transversely curved gate plate 25a tightly into engagement with the complementally transversely curved guide plate 24a.
The gate valve member 25 is reciprocated on the guide member 24 relative to the sleeve 16 by means of an integral upward guide and operating channel-like extension 31 extending upwardly from the gate plate 25a. This extension 31 will be disposed at the center-line of gate plate 25a and guide plate 24a and radially of the discharge outlet of the sleeve 16. It is formed so as to have a flat-finger lug 32 at its upper or outer end and a similar but split lug 33 at its inner or lower end. The extension 31 has opposed side guide flanges 35 which slideably fit in an undercut guide slot 34 in the wall 26 for vertical or radial reciprocation. It will be noted that this slot 34 produces a pair of lugs 26a on wall member 26 at its opposite forward corners. Below the lug 33, on the guide flanges 35, laterally-projecting stop lugs 36 are provided for engagement with the inner or undersurfaces of lugs 26a to limit upward or outward movement of gate valve member 25 on guide member 24. Lower movement normally is limited by stop lugs 28, which extend inwardly over the ends of guide channels 30, when they move into engagement therewith. However, sufficient downward force on the gate valve member 25 will cause the resilient lugs 28 to yield and permit member 25 to move off member 24. Thus, disassembly is possible for cleaning and reassembly is simple by a reversal of this procedure.
An example of a use of the gate assembly 15 is in the dispenser D of FIGS. 9 to 13. The housing thereof receives a bag B with a valve assembly 15 mounted on the spouts thereof. The housing has a vertical slot V which receives the spout S of the bag and will cooperate with flanges F on the spout to lock it and the valve assembly 15 carried thereby, in downwardly-inclined position so that all the contents will flow from the bag B.
To mount the valve assembly on the spout S, it is merely necessary to guide the tapered sleeve 16 thereof into the spout until the outer edge of the spout (FIG. 11) is engaged by the guide plate 24a. The interior surfaces of the spout will frictionally seal with the adjacent exterior surface of the sleeve 16 and at least one of the sealing ribs 17 will be engaged. In some instances, it is desirable to use an extension 40 on the spouts, as shown best in FIG. 11, to prevent the collapse of the bag B around the inlet end thereof and this can be carried by the valve assembly 15. It is shown as comprising a slotted tube 41 which has a collar 42 at its inner end that is complemental in taper to the interior taper of the bore 18 of the insert sleeve 16 of the valve. On its exterior surface, collar 42 is provided with locking groove 43 which receives the locking rib 22 of the sleeve 16 to lock the collar 42 and sleeve 16 together.
The gate valve member 25 may be moved between opened and closed positions with the fingers of one hand. Assume it is closed as shown in FIG. 12, the lugs 26a of guide member 24 may be engaged by the index finger and middle finger and the inner lug 33 of member 25 by the thumb. Then by exerting pressure, the gripped lugs will be moved together, thereby moving gate 25 radially outwardly on guide 24 and exposing the outlet end of dispensing passage 18. Now if the gate valve member 25 is to be closed, the thumb is engaged with one of the lugs 26a of guide 24 and the index finger is engaged with the lug 32 on the outer end of member 25. Then by exerting pressure, the gripped lugs will be moved together and the valve member 25 will be moved radially-inwardly into closed position.
The movement of the gate can be gradual from opened to closed positions or can be accomplished quickly. The passage 18 will be completely unobstructed when the valve is opened. Complete cut-off will occur when the valve reaches closed position and there will be an effective seal. The valve can function when the valve assembly is in inclined position and, thus, will function when a bag carrying the valve assembly is mounted in a dispenser of the type indicated. The valve can be actuated with one hand only. It can be readily disassembled for cleaning and can be easily reassembled. | A dispensing valve comprising a gate slideable transversely over the outer end of a passage from which is to be dispensed various viscous substances. The gate is slideable substantially at a right angle to the axis of the passage and the gate slide and guide are curved transversely relative to the direction of sliding movement so that the gate will be pulled axially into sealing engagement with the outer end of the passage as it moves thereover. Reciprocation of the gate can be accomplished with the fingers of one hand due to the provision of the cooperating lug arrangement on the slide gate and guide. | big_patent |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority from U.S. provisional patent application Ser. No. 60/319,668, filed on Nov. 5, 2002, the disclosure of which is hereby incorporated herein by reference in its entirety.
BACKGROUND OF INVENTION
[0002] The present invention is directed to a vehicular rearview mirror system and, in particular, a vehicular rearview mirror system in which an electro-optic reflective element assumes a partial reflectance level in response to a drive signal.
[0003] It is known for a mirror control to be responsive to an output of a vehicle control. For example, it is known to cause the reflectance level of an electro-optic reflective element to be forced into a high reflectance level when the vehicle is placed in reverse gear. An example of such a system is disclosed in commonly assigned U.S. Pat. No. 5,715,093 issued to Schierbeek et al., the disclosure of which is hereby incorporated herein by reference. The circuit that established the reflectance level of the reflective element monitors a switch or circuit that is actuated by the vehicle gearshift and which provides an indication that the gearshift is placed in reverse gear. In some vehicles, the reverse-gear indication has a protocol in which the indication changes from a low voltage level to a high voltage level when the vehicle is placed in reverse gear. In other vehicles, the protocol is that the reverse-gear indication changes from a high level to a low voltage level when the vehicle is placed in reverse gear. It is desirable to be able to install the same vehicle rearview mirror system in various vehicles irrespective of the protocol of the reverse-gear indication signal. The protocol, also known as a handshake, is the relationship between the reverse-gear indication signals when the vehicle is in reverse gear verses when it is not in reverse gear.
SUMMARY OF INVENTION
[0004] The present invention provides a vehicle rearview mirror system that is tolerant of different protocols of an output of a vehicle control. In this manner, the rearview mirror system can be used with various types of vehicles with modifications to the circuit.
[0005] A vehicular rearview mirror system suitable for use with a vehicle control, the vehicle control generating an output having a particular protocol representing a state of the output, according to an aspect of the invention, including a variable reflective element which assumes a partial reflectance level in response to a drive signal. The rearview mirror system further includes a mirror control that is responsive to the output of the vehicle control for generating at least one mirror control output. The at least one mirror control output includes a value for the drive signal. The mirror control determines the protocol of the output of the vehicle control including monitoring the output of the vehicle control in attempting to conclude a state of the output of the vehicle control.
[0006] The output of the vehicle control may be gear status information, engine information, alarm information, or door status information. In the case of the output being gear status information, the mirror control attempts to conclude a state of the output being whether the vehicle is in reverse gear or the vehicle is not in reverse gear. In the case where the output of the vehicle control is door status information, the mirror control attempts to conclude a state of the output being whether the vehicle doors are closed or a vehicle door is not closed. The at least one mirror control output may control a lighting assembly associated with an interior rearview mirror assembly and/or an exterior rearview mirror assembly.
[0007] The mirror control may include a microcomputer having software and the microcomputer determines the protocol by software processing. The microcomputer may monitor the output of the vehicle control upon starting of the vehicle and/or upon running of the vehicle. The rearview mirror system may include at least one light sensor and the mirror control may establish a value for the drive signal in response to an output of the at least one light sensor.
[0008] A vehicle rearview mirror system for use with a vehicle having a reverse gear and a reverse-gear indication wherein the reverse-gear indication has a particular protocol, according to an aspect of the invention, includes an electro-optic reflective element and a controller. The controller establishes a reflectance level of the reflective element including establishing a particular reflectance level in response to the reverse-gear indication indicating that the vehicle is in reverse gear. The controller determines the protocol of the reverse-gear indication including monitoring the reverse-gear indication and attempting to determine when the vehicle is in reverse gear and/or when the vehicle is not in reverse gear.
[0009] The controller may be a microcomputer having software and the microcomputer determines the protocol of the reverse-gear indication by software processing. The microcomputer may determine the reverse-gear protocol at least in part by monitoring a protocol of the reverse-gear indication upon starting of the vehicle. The microcomputer may also determine the reverse-gear protocol at least in part by monitoring a protocol of the reverse-gear indication during running of the vehicle. The microcomputer may determine the reverse-gear protocol by both monitoring the protocol of the reverse-gear indication upon starting of the vehicle and during running of the vehicle. The controller may maintain a reverse-inhibit-running parameter and a reverse-inhibit-ignition-cycle parameter.
[0010] These and other objects, advantages, and features of this invention will become apparent upon review of the following specification in conjunction with the drawings.
BRIEF DESCRIPTION OF DRAWINGS
[0011] [0011]FIG. 1 is a top plan view of a vehicle equipped with a rearview mirror system, according to the invention;
[0012] [0012]FIG. 2 is a block diagram of a rearview mirror system useful with the invention;
[0013] [0013]FIG. 3 is a flowchart of a power-up sequence, according to an embodiment of the invention; and
[0014] [0014]FIG. 4 is a flowchart of a main sequence, according to an embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0015] Referring now to the drawings and the illustrative embodiments depicted therein, a vehicle 10 is equipped with a vehicle rearview mirror system 12 which may include an interior mirror assembly 14 , a driver-side exterior mirror assembly 16 , and/or a passenger-side exterior mirror assembly 18 (FIG. 1). Each mirror assembly 14 , 16 , 18 includes an electro-optic reflective element, such as an electrochromic mirror element 20 , each mirror assembly further includes a mirror control circuit 22 including a mirror controller 24 that determines a reflectance level of the reflective element 20 of one or more of the mirror assemblies (FIG. 2). Mirror controller 24 may receive an input 26 indicative of light levels and produces an output 28 which causes reflective element 20 to assume a particular reflectance level. Input 26 may be produced by a glare light sensor 30 and an ambient light sensor 32 . Output 28 may be of any configuration known in the art. One example may be a pulse-width-modulated signal having a variable duty cycle, the value of which establishes a reflectance level of reflective element 20 , as disclosed in commonly assigned U.S. Pat. No. 6,056,410 issued to Hoekstra et al. and U.S. Pat. No. 6,089,721 issued to Schierbeek, the disclosures of which are hereby incorporated herein by reference. The operation of control 22 is disclosed in detail in commonly assigned U.S. Pat. No. 5,715,093 issued to Schierbeek et al. for a VEHICLE REARVIEW MIRROR SYSTEM WITH AUTOMATIC HEADLIGHT ACTIVATION, the disclosure of which is hereby incorporated herein by reference and will not be repeated herein. Glare and ambient light sensors 30 , 32 may also be used as an input 34 to a headlight activation control 36 for controlling a headlight circuit 38 as disclosed in the '093 patent. However, it should be understood that the invention may be used with an electrochromic mirror circuit which does not also include headlight activation.
[0016] Mirror controller 24 additionally receives as input from a vehicle control (not shown). The vehicle control provides an output having a protocol. By way of example, the vehicle control output may be a reverse-gear indication 40 from a reverse-gear circuit 42 . Reverse-gear circuit 42 is responsive to the vehicle shifter (not shown) or other indication of the gear in which the vehicle is placed, and produces reverse-gear indication 40 when the vehicle shifter is placed in reverse gear. Reverse-gear indication 40 may be of a protocol wherein the line goes from a low, or grounded state, to a high, or powered state, when the vehicle is placed in reverse gear. Alternatively, the protocol of reverse-gear indication 40 may be that the line goes from a high, or powered state, to a low, or grounded state, when the vehicle is placed in reverse gear. Mirror controller 24 is provided with appropriate biasing resistors in order to accommodate protocol of reverse-gear indication 40 . The arrangement of such biasing circuit is well within the skill of the ordinary practitioner. Other protocols may be possible and would be specific to the particular vehicle 10 in which the vehicle rearview mirror system 12 is installed. Mirror controller 24 may be responsive to other information provided by the vehicle control in an unknown protocol. Examples of such other information may include engine information, alarm information, door status information, or the like. It is known to cause a lighting assembly associated with a rearview mirror system to be turned on in response to vehicle door status information. Examples of such systems are disclosed in commonly assigned U.S. Pat. Nos. 5,497,305; 5,497,307; 5,669,689 and 5,669,704 in which a lighting assembly is associated with an exterior mirror assembly and U.S. Pat. No. 5,178,448 in which a lighting assembly is associated with an interior rearview mirror assembly, the disclosures of which are collectively hereby incorporated herein by reference.
[0017] Mirror controller 24 may be a microcomputer, or microprocessor, having non-volatile memory, such as in the form of electrically erasable programmable read-only memory (EEPROM), which is capable of storing data even when the vehicle is turned off. The microcomputer may also have programming code to carry out a control program having a power up sequence routine 44 (FIG. 3) and/or a main sequence routine 46 (FIG. 4).
[0018] Power-up sequence 44 may be carried out every time the vehicle is started, namely, whenever the vehicle's ignition line is powered. However, it should be understood that there are circumstances when the ignition line is powered but the vehicle has not yet started, such as when the ignition switch is turned past the accessory position while the occupant is operating an accessory. However, under usual circumstances, the powering of the ignition line is an indication that the vehicle is being operated. Controller 24 maintains a parameter called “reverse-inhibit-running average (or running average),” which is compared with two limits as follows:
[0019] Running high count
[0020] Running low count
[0021] and a “reverse-inhibit-ignition-cycle average (or ignition-cycle average)” parameter, which is compared with two limits as follows:
[0022] Ignition high count
[0023] Ignition low count
[0024] As will be set forth in more detail below, the running average parameter is a numerical value that is indexed at a particular frequency, such as every 30 seconds, every minute, every 5 minutes, or the like, whenever the vehicle ignition is energized. The running average parameter is maintained by main sequence 46 . Running high count, running low count, ignition high count and ignition low count in the illustrative embodiment are fixed parameters against which the running average parameter is compared by power-up sequence 44 , as will be set forth in more detail below. However, the skilled artisan may choose to make these parameters variable according to some condition or conditions. As such, running high count, running low count, ignition high count and ignition low count can be parameters that are set within the computer program or may be stored in the EEPROM. When the vehicle is initially produced, or when rearview mirror system 12 is initially installed in the vehicle, the parameters reverse-inhibit-running average and reverse-inhibit-ignition-cycle average are set to a value which represents a neutral condition, typically midway between the running average high count and the running average low count in the case of reverse-inhibit-running average and midway between the ignition high count and the ignition low count in the case of the reverse-inhibit-ignition-cycle average. For example, if an 8-bit register is used, which can register between 0 and 255, reverse-inhibit-running average and reverse-inhibit-ignition-cycle average may be set to the number 128. The running average low count and the ignition low count may be set to a number close to 0, such as 20, although these are for illustration only. Likewise, the running average high count and the ignition high count may be set to a value closer to 255, such as 235. Again, these being by way of example only.
[0025] Upon initiation of the power-up sequence at 48 , a series of comparisons 50 , 52 , 54 and 56 may be carried out. In comparison 50 , it is determined whether the running average parameter is greater than the running high count, which is suggestive of a reverse-gear indication high protocol. If not, it is determined at 52 whether the running average parameter is less than the running low count, which is suggestive of a reverse-gear indication active low protocol. If neither comparison 50 nor 52 are true, it is determined at 54 whether the ignition-cycle average parameter is greater than the ignition high count. If so, it is concluded that the reverse gear indication is an active high protocol. If comparison 54 is not true, it is determined at 56 whether the ignition-cycle parameter average is less than the ignition low count. If so, it is concluded that the reverse-gear indication is an active low protocol.
[0026] If neither comparison 50 , 52 , 54 or 56 is true, as would occur upon the initial power-up of the vehicle, controller 24 reads the reverse input 40 at 58 and determines at 60 whether the input port is high or not. If it is determined at 60 that the reverse input port is high, it is at least initially concluded that a reverse-gear indication is an active low protocol and a status flag is set at 62 to active low protocol. If it is determined at 60 that the reverse input port is not high, it is initially concluded that the reverse-gear indication is an active high and an active high flag is set at 64 . This conclusion is based upon an assumption that most likely the vehicle will not be in reverse gear when it is initially powered. However, this assumption may not always be true, such as in the case when a manual transmission vehicle is started in reverse gear with the clutch depressed. That is why the initial setting of the reverse-inhibit status flag is tentative and subject to reversal at a later time. After the reverse-inhibit status flag is set, the power-up sequence is exited at 66 .
[0027] Attention will now be turned to the main sequence 46 in FIG. 4. Main sequence 46 may be carried out for the entire duration that the vehicle ignition is powered. The main sequence begins at 68 , and a determination is made at 70 whether a particular time base TMR has expired. The timer may be set for any desirable period, such as 30 seconds, 1 minute, 5 minutes, or the like. The particular duration of the interval is a matter of design choice and can be appropriately selected by the skilled artisan. If it is determined at 70 that the time base has not expired, the loop is repeated until it is expired, at which time the timer is reset at 72 . The reverse input port 40 is read at 74 and a determination is made at 76 whether the input port is high. If it is determined at 76 that the reverse input port is high, the running average parameter is indexed downwardly at 78 . If it is determined at 76 that the reverse-input port is not high, the running average parameter is indexed upwardly at 80 . This logic is based upon the assumption that a vehicle, over time, will more likely be operated in reverse gear much less often than in a gear other than reverse gear. As this logic increases or decreases the value of reverse-inhibit-running average, the carry flag may be set to an upper overflow state from adding to the running average or to a lower underflow state by subtracting from the reverse-inhibit-running average. If main sequence 46 has added to the value of the running average parameter at 80 , it is determined at 82 whether the upper carry flag has been set, indicating that the count has reached the upper value. In order to avoid resetting of the register to 0, the control responds to the carry flag being set at 82 by setting at 84 the value of the running average parameter to the hexadecimal value of FFH, which is the maximum value. After the main sequence subtracts from the reverse-inhibit-running average at 78 , it is determined at 86 whether the lower underflow carry flag has been set. If the carry flag is set at 86 , the program sets at 88 the running average parameter to a 00H hexadecimal value. If it is determined at 82 or 86 that the respective carry flags are not set, the main sequence is continued at 90 .
[0028] Returning now to the power-up sequence 44 , if it is determined at 50 that the running average parameter is greater than the running high count parameter, the program indexes upwardly at 92 the parameter ignition-cycle average. It is then determined at 94 whether the value of the ignition-cycle average has reached an upper limit and, therefore, the carry flag is set. If so, the value of the ignition-cycle average is set at 96 to the hexadecimal value of FFH. Whether or not the carry flag is set, the ignition-cycle average parameter is compared with the ignition low count at 98 . If the ignition-cycle average is less than the ignition low count, the reverse-gear indication is set at 62 to an active low protocol. If the ignition-cycle average is not less than the ignition low count, the reverse-gear indication protocol is set at 64 to active high protocol.
[0029] If it is determined at 50 that the reverse-inhibit-running average is not greater than the running high count, and it is determined at 52 that the reverse-inhibit-running average is less than the running low count, the parameter ignition-cycle average is decremented downwardly at 100 . If it is determined at 102 that the carry flag is set, indicating that the value in the register has reached a low underflow level, the value for the ignition-cycle average is set at 104 to 00H. It is then determined at 106 if the ignition-cycle average is greater than the ignition high count. If so, the reverse-gear indication protocol is set at 64 to the active high protocol. If it is determined at 106 that the ignition-cycle average is not greater than the ignition high count, the reverse-gear indication protocol is set at 62 to the active low protocol. The power-up sequence is exited at 66 .
[0030] Thus, the software-based protocol, or handshake, determining technique disclosed herein utilizes a logical sequence of events in order to determine the protocol, or handshake, of an output of the vehicle control. One example of such output of the vehicle control is the reverse-gear indication. Upon initial start-up of the vehicle, the controller merely monitors, the reverse input port 40 and determines whether the port is high or low. On the basis of the assumption about the vehicle, such as that the vehicle is not in reverse gear, which assumption may or may not be true, an initial establishment of the protocol is made. However, the value of the running average parameter is repeatedly adjusted as the vehicle is operated using the assumption that the vehicle will more often be in a particular state than not in that state, such as that the vehicle will more often be in a gear other than reverse gear. Once the value of the running average reaches an extremely high or an extremely low value, the protocol for the output of the vehicle control is updated to a, presumably, more appropriate determination. The technique may continue to maintain the running average throughout the life of the vehicle to ensure that a proper protocol has been ascertained.
[0031] Whenever the vehicle is powered up, a fresh comparison is made between the value of reverse-inhibit-running average and the running high count and running low count in order to determine whether the value of reverse-inhibit-running average has exceeded the running high count or well below the running low count. If so, another parameter, reverse-inhibit-ignition-cycle average, is either incremented upwardly or decremented downwardly. If the value of ignition-cycle average exceeds an ignition high count or falls below an ignition low count, the reverse-gear indication protocol is reset to the value indicated thereby. The purpose of utilizing an ignition-cycle average that is incremented or decremented only upon vehicle power-up is in order to reduce the likelihood of anomalies affecting the performance of control 22 . For example, should a vehicle be left with the ignition running and in reverse gear, such as may happen when an owner is washing/waxing the vehicle with the radio turned on and the vehicle switch in the ignition position, the value of the reverse-inhibit-running average may reach an erroneous result because the vehicle may momentarily spend that time in reverse gear. However, during such interval, the vehicle is not powered up or is powered up only once. Therefore, although the value of the reverse-inhibit-running average may suggest an incorrect value for the reverse-gear indication protocol, the ignition-cycle average parameter would not. The ignition-cycle average value would override the value determined by reverse-inhibit-running average.
[0032] As indicated above, automatic dimming circuitry used in electrochromic mirror assemblies (such as disclosed in U.S. Pat. Nos. 4,793,690; 4,886,960; 4,799,768; 4,443,057 and 4,917,477, the entire disclosures of which are hereby incorporated by reference herein) may utilize one or more (typically two) photo sensors (such as photo resistors or photo diodes or photo transistors) to detect glaring and/or ambient lighting. For example, a silicon photo sensor, such as a TSL235R Light-to-Frequency converter (available from Texas Advanced Optoelectronic Solutions Inc. of Plano, Tex.), can be used as such photo sensors. Such light-to-frequency converters comprise the combination of a silicon photodiode and a current-to-frequency converter on a single monolithic CMOS integrated circuit. Alternately, a photo sensor that converts ambient light to a digital signal capable of direct feed into a microprocessor (or into a vehicle bus system, such as a LIN or CAN system or an SMBus) can be used. For example, a TSL2550 light sensor can be used that converts light intensity to a digital output (and is available from Texas Advanced Optoelectronic Solutions Inc. of Plano, Tex.). The TSL2550 Light-to-Digital photo sensor uses an all-silicon technique that combines two photodetectors to measure light brightness as perceived by the human eye, and calculates light intensity in units of lux. One photo sensor is sensitive to both visible and infrared light, while the other is sensitive only to infrared light. By such a combination, the infrared component of detected light is compensated for, and the output of the part is approximate the response of the human eye, thus obviating a need for a photopic filter. The ratio of infrared to visible light can be calculated and used to determine the type of light source (for example, incandescent or sunlight). Thus, for example, glaring light from headlamps (typically incandescent or high intensity discharge) can be distinguished from moonlight, sunlight, neon light, and the like.
[0033] Thus, it is seen that the present invention provides a technique for determining the protocol of the output of the vehicle control. This, advantageously, allows the same vehicular rearview mirror system to be utilized on cars having different output protocols. Advantageously, the invention may be implemented in software, thereby reducing hardware expenses associated with the function. This is because the microcomputer may already be in place in the vehicle mirror control system, such as in order to establish a reflectance level of the electrochromic mirror element. Therefore, any hardware overhead associated with this function would be negligible. Furthermore, the software solution can be carried utilizing an 8-bit register, which further reduces the amount of software resources necessary to implement the invention.
[0034] Changes and modifications in the specifically described embodiments can be carried out without departing from the principles of the invention which is intended to be limited only by the scope of the appended claims, as interpreted according to the principles of patent law including the Doctrine of Equivalents. | A vehicular rearview mirror system suitable for use with a vehicle control, the vehicle control generating an output having a particular protocol representing a state of the output. The vehicle rearview mirror system includes a variable reflective element which assumes a partial reflectance level in response to a drive signal. The rearview mirror system further includes a mirror control that is responsive to the output of the vehicle control for generating at least one mirror control output. The at least one mirror control output includes a value for the drive signal. The mirror control determines the protocol of the output of the vehicle control including monitoring the output of the vehicle control in attempting to conclude a state of the output of the vehicle control. | big_patent |
BACKGROUND OF THE INVENTION
The field of the present invention is anti-lock brake systems for motorcycles.
Anti-lock braking systems for the front wheel of a motorcycle have been developed which include a master cylinder which may be actuated by the operator, a front wheel brake operated by the master cylinder through a brake line therebetween and an anti-lock control unit interposed in the brake line between the master cylinder and the front wheel brake. The anti-lock control unit is adapted to sense the nearly-locked condition of a front wheel and shut off the hydraulic pressure to the brake itself. One such braking system is disclosed in Japanese Patent Laid-open Publication No. 120440/1981.
With the motorcycle provided with such an anti-lock braking system, the chassis may vibrate when the front wheel brake is applied. This vibration occurs in a vertical direction with the repeated operation of an anti-lock control unit which rapidly cycles the brake on and off under conditions of approaching wheel lock. The problem is aggregated with motorcycles having high centers of gravity and short wheel bases.
The reaction of the front fork responsive to the action of braking and of the anti-lock braking device is to begin to dive. As the dive commences, a short period of time exists where there is no increase of the front wheel load on the tire contact with the ground. Consequently, there is no increase in the resistance to locking of the brake during that short period. Consequently, a slight decrease in braking efficiency could theoretically be experienced.
SUMMARY OF THE INVENTION
The present invention is directed to an anti-lock braking system employing an anti-dive device with a damped telescopic front suspension. The anti-dive device is responsive to the brake force applied to the front wheel. The cooperation may be achieved by tapping hydraulic pressure downstream of the anti-lock control unit or by sensing and applying the actual reaction to braking force of the front wheel.
Accordingly, it is an object of the present invention to provide an anti-lock brake system having anti-dive characteristics. Other and further objects and advantages will appear hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1-7 illustrate a first embodiment of the present invention, wherein:
FIG. 1 is a schematic plan of a motorcycle provided with an anti-lock braking system on a front wheel;
FIG. 2 is a sectioned side elevation of a principal portion of the anti-lock braking system;
FIGS. 3 and 4 are sectional views taken along the lines III--III and IV--IV, respectively, in FIG. 2;
FIG. 5 is an enlarged sectional view taken along the line V--V in FIG. 4;
FIG. 6 is a wiring diagram of a display circuit in FIG. 2; and
FIG. 7 is a side elevation of the anti-lock braking system with a front fork shown in section.
FIG. 8 is a side elevation similar to FIG. 7, showing a second embodiment of the present invention; and
FIG. 9 is a graph showing the relation between the time and the angular velocity characteristics during the anti-lock controlling of a front wheel brake, wherein a curve a indicates the characteristics of a prior art anti-lock braking system of this kind; and a curve b the characteristics of the anti-lock braking system according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The embodiments of the present invention will now be described.
First, referring to FIG. 1 which shows a first embodiment of the present invention, a motorcycle 1 is provided with left and right front wheel brakes 3f, 3f for braking a front wheel 2f, and first and second rear wheel brakes 3r 1 , 3r 2 for braking a rear wheel 2r. Both of the front wheel brakes 3f, 3f and the first rear wheel brake 3r 1 are operated by an output hydraulic pressure from a front master cylinder 5f which is operated by a brake lever 4, and the second rear wheel brake 2r by an output hydraulic pressure from a rear master cylinder 5r which is operated by a brake pedal 6. Especially, the hydraulic braking pressure for the front wheel brakes 3f, 3f is controlled by an anti-lock control unit 7.
Referring to FIGS. 2 and 3, a hub 8 of the front wheel 2f is supported via bearings 11, 11 on an axle 10 which is supported at its both ends on the lower ends of left and right telescopic fork members 9l, 9r constituting a front fork 9. Each of the two front wheel brakes 3f, 3f, which are provided on both sides of the front wheel 2f, consists of a brake disc 12 attached to an end surface of the hub 8, and brake caliper 14 supported on the front fork 9 via a bracket 13 in such a manner that the brake caliper 14 straddle the brake disc 12. The brake caliper 14 is adapted to be operated when an output hydraulic pressure is supplied from the master cylinder 5f into an input port 14a thereof, thereby being rendered capable of holding the brake disc 12 firmly from both sides thereof to apply braking force to the front wheel 2f.
The anti-lock control unit 7 is provided in a hydraulic pipe 15 by which an output port 5fa of the front master cylinder 5f and the input port 14a of each of the brake calipers 14 are connected.
The anti-lock control unit 7 consists mainly of a hydraulic pump 16 adapted to be driven by the front wheel 2f when braking, a modulator 17 having a hydraulic control chamber 18, into which the discharge pressure from the hydraulic pump 16 is introduced, and provided in an intermediate portion of the hydraulic pipe 15, a normally-closed pressure discharge valve 20 provided in a communication passage between the hydraulic control chamber 18 and an oil tank 19, and an inertial sensor 21 adapted to detect the nearly-locked condition of the front wheel 2f and open the pressure discharge valve 20. These main constituent parts are arranged in a casing 22.
The casing 22 is formed of a cup-shaped case member 22a, and a cover member 22b fitted into an open end of the case member 22a and fixed thereto with screws 23. The case member 22a is provided so that it is held in a recess 8a formed in one end surface of the hub 8. The cover member 22b is supported on the axle 10 via a hollow shaft 24 provided fixedly in the central portion thereof, and joined to the front fork 9 via a rotation-preventing means so that the case member 22b does not turn around the axle 10. The rotation-preventing means may consist of an arbitrarily-selected part; it suitably consists, for example, of the bolts 25 (refer to FIG. 2) by which the bracket 13 is secured to the front fork 9.
The hydraulic pump 16 consists of a cam shaft 26 provided in parallel with the axle 10, a push rod 27 provided so as to oppose its inner end to an eccentric cam 26a formed on the cam shaft 26, a pump piston 28 contacting the outer end of the push rod 27, an operating piston 29 contacting the outer end of the pump piston 28, and a return spring 30 urging the push rod 27 in the direction in which the push rod 27 is apart from the eccentric cam 26a.
The push rod 27 and pump piston 28 are fitted slidably in a first cylindrical bore 33 formed in the cover member 22b, so as to define an inlet chamber 31 and an outlet chamber 32 on the outer side of the outer circumferential surfaces thereof, respectively. A plug 34 is fitted fixedly into the outer end portion of the first cylindrical bore 33 so that a pump chamber 35 is defined between the plug 34 and pump piston 28. The operating piston 29 is fitted slidably in the plug 34 so as to define a hydraulic chamber 36 therein.
The inlet chamber 31 is communicated with the oil tank 19 via a pipe 37, and with the pump chamber 35 via a suction valve 38, the pump chamber 35 being communicated with the outlet chamber 32 via a one-way seal member 39 having the function of a discharge valve. The hydraulic chamber 36 is connected to an upstream member 15a of the hydraulic pipe 15 so as to be communicated constantly with an output port 5fa in the front master cylinder 5f.
As shown in FIG. 4, the cam shaft 26 is supported on the cover member 22b via bearings 40, 40', and adapted to be driven via a pair of gears 43, 44 by a driving shaft 42 which is supported rotatably on the hollow shaft 24 via bearings 41, 41. The driving shaft 42 is adapted to be driven by the front wheel 2f via a speedup gear 45, which will be described later.
A meter driving gear 49 is mounted fixedly on an outer end portion, which is on the opposite side of the gear 44, of the cam shaft 26, and meshed with a driven gear 50 which is connected to an input shaft of a speedometer 51 on the motorcycle.
The modulator 17 consists of a pressure reduction piston 46, a fixed piston 47 receiving one end of the reduction piston 46 to limit the backward movement thereof, and a return spring 48 urging the piston 46 in the direction in which the piston 46 engages with the fixed piston 47. Both of these pistons 46, 47 are fitted slidably in a second cylindrical bore 52 which is formed in the cover member 22b so that the second cylindrical bore 52 is adjacent to the first cylindrical bore 33.
In the second cylindrical bore 52, the reduction piston 46 defines a hydraulic control chamber 18 between itself and the inner end wall of the bore 52, and a hydraulic output chamber 55 between itself and the fixed piston 47. The fixed piston 47 defines a hydraulic input chamber 54 on the outer side of the outer circumferential surface thereof. This hydraulic chamber 54 communicates with the chamber 36 in the hydraulic pump 16 via an oil passage 56. The hydraulic output chamber 55 is connected to a downstream pipe 15b of the hydraulic pipe 15 so as to be communicated constantly with the input ports 14a of the front wheel brakes 3f, 3f. The hydraulic control chamber 18 is communicated with the outlet chamber 32 in the hydraulic pump 16 via an oil passage 57.
The fixed piston 47 is provided with a valve chamber 58 communicated constantly with the hydraulic input chamber 54, and a valve port 59 by which the valve chamber 58 is communicated with the hydraulic output chamber 55. The valve chamber 58 is provided therein with a valve body 60 capable of opening and closing the valve port 59, and a valve spring 61 urging the valve body 60 toward the closed position. A valve rod 62 for opening the valve body 60 projects from one end surface of the reduction piston 46. This valve rod 62 keeps the valve body 60 open when the reduction piston 46 is in a limit position of the backward movement thereof.
The outer, open portion of the second cylindrical bore 52 is closed by an end plate 63 fixed to the cover member 22b. The fixed piston 47 is kept constantly in engagement with the end plate 63, because of the resilient force of the return spring 48 or the hydraulic pressure introduced into the hydraulic input and output chambers 54, 55.
The hydraulic pump 16 and modulator 17 are disposed on the rear side of the front fork 9 in the same manner as the brake caliper 14.
The pressure discharge valve 20 consists of a valve seat member 65 fitted firmly in a stepped cylindrical bore 64 in the cover member 22b, and a valve body 67 fitted slidably in the valve seat member 65 so as to open and close a valve port 66 thereof. The valve seat member 65 defines an inlet chamber 68 in a smaller-diameter portion of the stepped cylindrical bore 64, and an outlet chamber 69 in a larger-diameter portion thereof, these chambers 68, 69 being communicated with each other via the valve port 66. The inlet chamber 68 is in communication with the hydraulic control chamber 18 in the modulator 17 via the oil passage 20. The outlet chamber 69 is in communication with the inlet chamber 31 in the hydraulic pump 16 via an oil passage 71. Consequently, the outlet chamber 69 is in communication with the oil tank 19.
The sensor 21 consists of a speedup gear 45 into which power is input from the front wheel 2f, a flywheel 72 adapted to be rotated by the speedup gear 45, a cam means 73 for converting overrun rotation of the flywheel 72 into axial displacement, and an output lever means 74 capable of operating the pressure discharge valve 20 in accordance with the axial displacement of the flywheel 72. The speedup gear 45 is provided on the outer side of a rear wall of the case member 22a. The cam means 73, flywheel 72 and output lever means 74 are on the inner side of the case member 22a.
The speedup gear 45 has a planetary gear construction, and consists of a ring gear 76, which is pline-fitted on the inner circumferential surface of an annular support portion 75 projecting from the outer surface of the rear wall of the case member 22a, a plurality of planetary gears 78 supported rotatably 77 on the hub 8 and meshed with the ring gear 76, and a sun gear 79 formed at one end portion of the driving shaft 42 and meshed with the planetary gears 78.
A seal member 80 is inserted between the rear wall of the case member 22a and the driving shaft 42 extending therethrough. A seal member 81 is also inserted between the annular support portion 75 of the case member 22a and the hub 8.
In order to prevent the rotation of the front wheel 2f from being hindered if an overload is applied to the driving shaft 42, at least one of the constituent gears of the speedup gear 45, for example, the planetary gear 78, is made of a synthetic resin having a safety function like that of a fuse in that it breaks when torque on that gear exceeds a predetermined level.
The speedometer 51 is operatively connected to the driving shaft 42 which is driven by the speedup gear 45. Accordingly, if the gear 78 which is made of a synthetic resin should be broken, the speedometer stops operating in spite of the rotation of the front wheel 2f, so that the rider can therefore learn the occurrence of this accident.
The cam means 73 consists, as shown in FIG. 5, of a driving cam plate 82 fixed to the driving shaft 42, a driven cam plate 83 provided in opposition to the driving cam plate 82 so that the driven cam plate 83 can be rotated relatively thereto, and a thrust ball 84 engaged with cam recesses 82a, 83a in the opposite surfaces of the cam plates 82, 83. The cam recess 82a in the driving cam plate 82 is inclined so that the bottom surface of the recess 82a is shallower in the rotational direction 85 of the driving shaft 42. The cam recess 83a in the driven cam plate 83 is inclined so that the bottom surface of the recess 83a is deeper in the rotational direction 85 mentioned above. Accordingly, in a normal case where the driving cam plate 82 takes the driving position with respect to the driven cam plate 83, the thrust ball 84 engages the deepest portions of the cam recesses 82a, 83a, and the rotary torque received by the driving cam plate 82 from the driving shaft 42 is simply transmitted to the driven cam plate 83, so that the relative rotation of the cam plates 82, 83 does not occur. When the position of the driving cam plate 82 is reversed, i.e., when the driven cam plate 83 overruns the driving cam plate 82, the cam plates 82, 83 rotate relatively to each other. Consequently, the thrust ball 84 rolls in a climbing manner on the inclined bottom surfaces of the cam recesses 82a, 83a to apply thrust to these cam plates 82, 83 and cause the driven cam plate 83 to be displaced axially, i.e., in the direction in which the driven cam plate 83 is removed from the driving cam plate 82.
In order to lessen the impact occurring when the thrust ball 84 suddenly reaches the rolling limit in the cam recesses 82a, 83a, at least one of the constituent elements of the cam means 73 is made of a synthetic resin. In the illustrated embodiment, the driven cam plate 83 and the thrust ball 84 are made of a synthetic resin. This prevents vibration of the cam means 73, which is caused by such an impact, thereby proving the durability thereof.
The flywheel 72 is supported rotatably and slidably at its boss 72a on the driving shaft 42 via a bushing 86. The driven cam plate 83 is supported rotatably on the boss 72a, and engages one side surface of the flywheel 72 via a friction clutch plate 87. A pressure plate 89 is provided on the other side surface of the flywheel 72 via a thrust bearing 88.
The output lever means 74 has a support shaft 90 projecting from the portion of the inner surface of the cover member 22b which is between the axle 10 and pressure discharge valve 20, and a lever 91 supported on a neck portion 90a of a free end section of the support shaft 90 so that the lever 91 can be moved pivotally in the axial direction of the axle 10. A clearance 92 of a predetermined width extending in the pivoting direction of the lever 91 is provided between the neck portion 90a and lever 91. The lever 91 consists of a first longer arm 91a extending from the support shaft 90 to extend around the driving shaft 42, and a second shorter arm extending toward the pressure discharge valve 20. The first arm 91a is provided at an intermediate point with a contact portion 93 to engage the outer surface of the pressure plate 89. The contact portion 93 has a rounded projection toward the outer surface of the pressure plate.
A spring 94 is provided between a free end portion of the first arm 91 and the cover member 22b. A free end portion of the second arm 91b engages the outer end of the valve body 67 in the pressure discharge valve 20.
The resilient force of the spring 94 is applied to the lever 91 to press the contacting portion 93 of the first arm 91a against the pressure plate 89, and normally serves to press the valve body 67 in the pressure discharge valve 20 to thereby keep the valve 20 closed. The pressure received by the pressure plate 89 from the spring 94 generates the frictional locking force in three parts, i.e. the flywheel 72, friction clutch plate 87 and driven cam plate 83, and such force in the two cam plates 82, 83 that causes them to move toward each other.
When rotary torque which exceeds a predetermined value is applied between the driven cam plate 83 and flywheel 72, the above-mentioned frictional locking force is set so that slip occurs on the friction clutch plate 87.
A detecting unit 95 for detecting normal operation of the output lever means 74 is connected thereto. This detecting unit 95 consists of a switch holder 96 held firmly in the cover member 22b and projecting into a coiled portion of the spring 94, a lead switch 97 supported on the switch holder 96 in the coiled portion of the spring 94, and a permanent magnet 98 attached to the first arm 91a so as to be opposed to the lead switch 97. When the first arm 91a is turned at a predetermined angle toward the cover member 22b, the permanent magnet 98 is displaced to a position in which the lead switch 97 is closed.
A display circuit 99 is connected to the lead switch 97. The display circuit 99 is formed as shown in FIG. 6. When a main switch 100 is closed, an electric current flows from a power source 101 to the base of a transistor 104 through the main switch 100 and resistors 102, 103, so that the transistor 104 is turned on. Consequently, a display lamp 105 is turned on through the main switch 100 and kept lit. When the permanent magnet 98 is then displaced to the lead switch 97 to close the same, an electric current flows to the gate of a thyrister 106 through the lead switch 97. As a result, the thyrister 106 is turned on, and the electric current passing through the resistor 102 flows to the thyrister 106, so that the transistor 104 is turned off with the display lamp 105 then turned off. Accordingly, it can be detected by the interruption of the ON-state of this display lamp 105 that the lever 91 has been turned to the side of the cover member 22b against the resilient force of the spring 94. Even when the lever 91 is then returned to its original position to open the lead switch 97, the OFF-state of the display lamp 105 is retained by the thyrister 106 until the main switch 100 has been opened and then closed again.
An ignition switch or a braking switch for a motorcycle can be used as the main switch.
Returning to FIG. 1 again, an interconnecting pipe 110 branching from the intermediate portion, which is between the front master cylinder 5f and anti-lock control unit 7, of the hydraulic pipe 15, i.e. the upstream pipe 15a is connected to the input port of the first rear wheel brake Br 1 , and a proportional reducing valve 111 is provided in the intermediate portion of the interconnecting pipe 110. This proportional reductive valve 111 is a valve known in the art which is adapted to reduce the hydraulic output pressure from the front master cylinder 5f when this pressure has exceeded a predetermined level, and to transmit the resultant hydraulic pressure to the first rear wheel brake 2r 1 .
A hydraulic pipe 112, which extends from the output port of the rear master cylinder 5r, is connected to the input port of the second rear wheel brake Br 2 . Accordingly, the second rear wheel brake Br 2 is operated only when the rear master cylinder 5r is actuated.
While the vehicle runs, the driving shaft 42 is driven at an increased speed due to the rotational force transmitted from the front wheel 2f thereto via the speedup gear 45, and the flywheel 72 is then driven via the cam means 73 and friction clutch plate 87, so that the flywheel 72 is rotated at a higher speed than the front wheel 2f. Therefore, the flywheel 72 has a large rotary inertial force.
At the same time that the flywheel is rotated, the cam shaft 26 and speedometer 51 are also driven by the driving shaft 42.
When the front master cylinder 5f is operated so as to brake the vehicle, the hydraulic output pressure therefrom is transmitted to the front wheel brakes 3f, 3f via the upstream pipe 15a of the hydraulic pipe 15, hydraulic chamber 36 in the hydraulic pump 16, hydraulic input chamber 54 in the modulator 17, valve chamber 58, valve port 59, hydraulic output chamber 55, and downstream pipe 15b of the hydraulic pipe 15 in the mentioned order. This hydraulic output pressure is also transmitted to the first rear wheel brake Br 1 via the upstream pipe 15a and interconnecting pipe 110. The front and rear wheel brakes 3f, 3f, Br 1 can thus be operated to apply braking force to the front and rear wheels 2f, 2r at once.
In the hydraulic pump 16, the hydraulic output pressure from the front master cylinder 5f is introduced into the hydraulic chamber 36. Consequently, the pump piston 28 is moved reciprocatingly due to the pressing effect of the hydraulic pressure on the operating piston 29 and the lifting effect of the eccentric cam 26a on the push rod 27. In a suction stroke in which the pump piston 28 is moved toward the push rod 27, the suction valve 38 is opened, and the oil in the oil tank 19 is sucked from the pipe 35 into the pump chamber 35 via the inlet chamber 31. In an exhaust stroke in which the pump piston 28 is moved toward the operating piston 29, the one-way seal member 39 makes a valve-opening action to cause the oil in the pump chamber 35 to flow under pressure into the output chamber 32 and then into the hydraulic control chamber in the modulator 17 via the oil passage 57. When the pressures in the output chamber 32 and hydraulic control chamber 18 have increased to a predetermined level, the pump piston 28 is held in the position, in which the pump piston 28 is engaged with the plug 34, due to the pressure in the output chamber 32.
The communication between the hydraulic control chamber 18 in the modulator 17 and the oil tank 19 is initially cut off since the pressure discharge valve 20 is closed. Accordingly, the hydraulic pressure supplied from the hydraulic pump 16 to the hydraulic control chamber 18 is applied directly to the reduction piston 46 to hold the piston 46 in the position in which the backward movement thereof is limited, and the valve body 60 is kept open by the valve rod 62 to thereby permit the passage of the hydraulic output pressure from the front master cylinder 5f.
Therefore, in the initial stage of a braking operation, the level of the braking force applied to the front wheel brakes 3f, 3f varies in proportion to that of the hydraulic output pressure from the front master cylinder 5f.
When angular deceleration occurs in the front wheel 2f during this braking operation, the flywheel 72, which senses this phenomenon, is formed to make an overrunning rotation with respect to the driving shaft 42 due to the inertial force thereof. During this time, the moment of rotation of the flywheel 72 causes the two cam plates 82, 83 to be turned relatively to each other, and the thrust occurring due to the rolling of the thrust ball 84 causes the flywheel 72 to be displaced axially, and the pressure plate 89 to press the lever 91.
The movement of the lever 91 being pressed by the pressure plate 89 will now be discussed. Since the clearance 92 exists between the support shaft 90 and lever 91, the lever is supported initially at three points, i.e., on the spring 94, pressure plate 89 and pressure discharge valve 20. When the lever 91 is pressed by the pressure plate 89, it is turned about the valve body 67 as a fulcrum. When this pivotal movement of the lever 91 has progressed to the extent that the lever 91 has attained a predetermined angle, the clearance 92 between the support shaft 90 and lever 91 is lost, and the fulcrum on the side of the second arm 91b is moved from the valve body 67 to the support shaft 90 which is closer to the contacting portion 93. As a result, the lever 91 is then turned about the support shaft 90 as a fulcrum.
The lever ratio at which the lever 91 is turned by the pressure plate 89 thus varies in two steps. Therefore, even if the resilient force of the spring 94 is constant, the lever 91 is turned initially by a comparatively low pressure from the pressure plate 89. After the fulcrum of the lever 91 with respect to the pivotal movement thereof has been moved, the lever is not turned unless the pressure from the pressure plate 89 is increased to a predetermined level. Accordingly, the lever 91 is turned by the pressure from the pressure plate 89 in the stage of a braking operation in which the angular deceleration occurring in the front wheel 2f is comparatively small, to cause the permanent magnet 98 to be moved to a position close to the closing position of the lead switch 37. Consequently, the display circuit 99 is actuated in the previously-described manner, so that the rider can ascertain that the sensor 21 is normally operated.
When the front wheel 2f is about to be locked due to the excessively large braking force or a decrease in the coefficient of friction of the road surface, the angle of deceleration of the front wheel 2f then increases suddenly. As a result, the pressure from the pressure plate 89 exceeds a predetermined level, and the lever 91 is turned about the support shaft 90 as a fulcrum so as to further compress the spring 94, so that the second arm 91b of the lever 91 is turned so as to be removed from the valve body 67. This causes the pressure discharge valve 20 to be opened.
When the pressure discharge valve 20 is opened, the hydraulic pressure in the hydraulic control chamber 18 is discharged to the oil tank 19 via the oil passage 70, inlet chamber 68, valve port 66, outlet chamber 69, oil passage 71, inlet chamber 31 in the hydraulic pump 16, and pipe 37. Therefore, the pressure reduction piston 46 is moved toward the hydraulic control chamber 18 by the hydraulic pressure from the hydraulic output chamber 55 against the resilient force of the return spring 48. Consequently, the valve rod 62 is moved back to close the valve body 60, shut off the hydraulic input and output chambers 54, 55 from each other and increase the capacity of the hydraulic output chamber 55. In consequence, the hydraulic braking pressure applied to the front wheel brakes 3f, 3f decreases, and the braking force for the front wheel 2f decreases. This can prevent the front wheel 2f from locking. As a result, the front wheel 2f is accelerated, and the lever 91 is released from the pressure from the pressure plate 89, so that the lever 91 pivots to its original position due to the resilient force of the spring 94 to close the pressure discharge valve 20. When the pressure discharge valve 20 has been closed, the pressure oil discharged from the hydraulic pump 16 is trapped immediately in the hydraulic control chamber 18, and the reduction piston 46 is moved back toward the hydraulic output chamber 55 to increase the pressure in the chamber 55 and regain the braking force. Since such operations are repeated at a high speed, the front wheel 2f can be braked very efficiently.
Referring to FIG. 7, each of the telescopic forks 9l, 9r is provided with a bottom case 120, and a fork pipe 121 fitted slidably in the bottom case 120. At the lower end of the bottom case 120, an end portion of the axle 10 is supported fixedly by a holder 122. In the interior of the bottom case 120, a seat pipe 123, which is concentric with the bottom case 120, is fitted firmly in such a manner that a piston 124 formed integrally with and at the upper end portion of the seat pipe 123 slidably engages the inner circumferential surface of the fork pipe 121. In the interior of the fork pipe 121, a suspension spring 125 is provided between the upper end portion thereof and the piston 124 so that the spring 125 urges the relative fork 9l, 9r in the extending direction thereof. A buffer valve means 126 having an orifice and a check valve is provided between the inner surface of the lower end portion of the fork pipe 121 and the outer surface of the seat pipe 123. The upper and lower hydraulic chambers 127, 128, which are communicated with each other via the buffer valve means 126, are formed around the seat pipe 123.
A partition member 129 is provided between the lower end portions of the bottom case 120 and seat pipe 123. As a result, a hydraulic relay chamber 131, which is communicated with a reserve oil chamber 130 on the inner side of the seat pipe 123 and fork pipe 121, is defined in the lowermost portion of the interior of the bottom case 120. A check valve 132, which permits the oil to flow in only one direction from the hydraulic relay chamber 131 to the lower hydraulic chamber 128, is provided on the upper portion of the partition member 129.
An anti-dive unit 133 is provided on the front surface of the lower portion of each of the telescopic forks 9l, 9r or the bottom case 120 in one of the forks 9l, 9r. This anti-dive unit 133 is provided with a housing 137 having an upper port 134 communicated with the lower hydraulic chamber 128, a lower port 135 communicated with the hydraulic relay chamber 131, and a valve chamber 136 communicating these ports 134, 135 with each other, a valve seat 139 positioned between the ports 134, 135 and held on a shoulder portion of the valve chamber 136 by a retainer spring 138, a valve body 140 held in the valve chamber 136 so as to open and close the same in cooperation with the valve seat 139, and a valve spring 141 urging the valve body 140 in the valve-open direction. The rear surface, which faces in the direction opposite the valve seat 139, of the valve body 140 is provided with a piston 142 formed integrally with the valve body 140 and extending to the outside of the valve chamber 136. This piston 142 defines a pressure receiving chamber 143 within the housing 137. This pressure receiving chamber 143 is communicated with the output port 5fa of the front master cylinder 5f via a pipe 144.
While the front master cylinder 5f is not in operation, the valve body 140 in the anti-dive unit 133 is open. When the front fork 9 starts contracting with the valve body 140 open, the pressure in the lower hydraulic chamber 128 increases, and the upper hydraulic chamber 127 is vacuumed. Accordingly, the oil in the lower hydraulic chamber 128 flows with a low flow passage resistance into the upper hydraulic chamber 127 through the check valve in the buffer valve means 126, and also into the hydraulic relay chamber 131 through the upper port 134, valve chamber 136 and lower port 135, the oil being further flowing into the reserve oil chamber 130 with substantially no resistance. As a result, a slight damping force occurs in the buffer valve means 126, and substantially no damping force in the anti-dive unit 133.
Conversely, when the front fork 9 starts extending, the pressure in the upper hydraulic chamber increases, and the lower hydraulic chamber is vacuumed. Accordingly, the oil in the upper hydraulic chamber 127 flows with a high flow passage resistance into the lower hydraulic chamber 128 through the orifice in the buffer valve means 126. At the same time, the oil in the reserve oil chamber 130 flows into the lower hydraulic chamber 128 through the hydraulic relay chamber 131, lower port 135, valve chamber 136 and upper port 134. As a result, a strong damping force occurs in the buffer valve means 126. However, substantially no damping force occurs in the anti-dive unit in the same way as in the above-mentioned case.
When the front master cylinder 5f operates to actuate the front wheel brake 3f, the output hydraulic pressure therefrom is transmitted to the pressure-receiving chamber 143 as well in the anti-dive unit 133 to press the piston 142 downward. Consequently, the valve body 140 is set on the valve seat 139, and the valve chamber 136 is closed or limitedly opened. When the front fork 9 then starts contracting, the passage of the oil in the lower hydraulic chamber 128 through the valve chamber 136 is stopped or greatly limited, so that a great damping force occurs. This enables the contraction of the front fork 9 to be suitably restricted.
Conversely, when the front fork 9 starts extending the oil in the reserve oil chamber 130 flows to open the check valve 132 and enter the lower hydraulic chamber 128 with a comparatively low pressure. Therefore, the damping force occurs in the anti-dive unit 133, and the front fork 9 extends substantially in the same manner as in the case where the master cylinder 5f is not in operation.
While the hydraulic braking pressure for the front wheel brake 3f is increased and decreased repeatedly by the anti-lock control unit 7 during an operation of the front wheel brake 3f, a downward load is applied from the chassis to the front fork 9 every time the hydraulic braking pressure is increased, to exert the contracting force thereon. However, the contracting action of the front fork 9 is suitably suppressed by the great damping force generated by the anti-dive unit 133. Accordingly, the grounding load on the front wheel 2f increases immediately to cause the frictional force generated between the front wheel 2f and the road surface to increase quickly. This enables the variations in the angular deceleration of the front wheel to be minimized as shown by a line b in FIG. 9.
FIG. 8 shows a second embodiment of the present invention, in which an anti-dive unit 133 is formed of a braking torque-responding type anti-dive unit. To be more precise, a housing 137 is secured to the portion of the rear surface of a bottom case 120 which is opposed to the brake caliper 14 in a front wheel brake 3f, and a piston 145, which can be moved slidingly in the radial direction of the bottom case 120, is fitted slidably in the housing 137, an oil passage 146, which is opened and closed in accordance with the forward and backward movements of the piston 145, and which has a low flow passage resistance, being provided between the bottom case 120 and housing 137. This oil passage 146 is so provided that a lower hydraulic chamber 128 and a hydraulic relay chamber 131 are in communication with each other. An orifice 147, which shunts the portion opened and closed by and with the piston 145 of this oil passage 146, and which communicates both end portions of the same oil passage 146, is provided in the piston 145.
The housing 137 is further provided therein with a return spring 148, which urges the piston 145 in the direction in which the oil passage 146 is opened, i.e., in the direction in which the piston 145 is moved back, and an operating rod 149 capable of urging the piston 145 in the direction in which the oil passage 146 is opened, i.e., in the direction in which the piston 145 is moved forward. This operating rod 149 is connected to the brake caliper 14 in the front wheel brake 3f via a link 150. One end of a bracket 13 which supports the brake caliper 14 is connected pivotably to the bottom case 120 via a pivot 25' so that the brake caliper 14 is turned or displaced relative to the piston 145 by the braking torque when the brake caliper 14 holds a brake disc 12 therein firmly.
The construction of the remaining portion of this embodiment is substantially identical with that of the corresponding portion of the previously-described embodiment. In FIG. 8, the parts corresponding to those of the previous embodiment are designated by the same reference numerals.
While the front wheel 2f is not braking, the piston 145 in the anti-dive unit 133 is held in a retracted portion due to the resilient force of the return spring 148 to keep the oil passage 146 open. Accordingly, when the front fork 9 then extends and contracts, the oil flows with substantially no resistance between the lower hydraulic chamber 128 and hydraulic relay chamber 131 through the oil passage 146, so that the damping force does not occur in the anti-dive unit 133.
While the front wheel brake 3f is in operation, i.e., while the brake disc 12 is held firmly in the caliper 14, the brake caliper 14 is turned by the braking torque about the pivot 25' toward the piston 145. Consequently, the piston 145 moves forward via link 150 and operating rod 149 to close the oil passage 146.
Therefore, when a downward load is then applied from the chassis to the front fork 9 to cause the front fork to start contracting, the oil in the lower hydraulic chamber 128 flows with a high flow passage resistance into the hydraulic relay chamber 131 through the orifice 147, so that the strong damping force occurs therein. Owing to this damping force, the contracting action of the front fork is suitably suppressed. The suppression of such a contracting action of the front fork 9 is done every time the hydraulic braking pressure for the front brake 3f is increased by the anti-lock control unit 7 in the same manner as in the previously-described embodiment.
When the hydraulic braking pressure applied to a front wheel increases and decreases repeatedly due to an operation of an anti-lock control unit while a front wheel brake is operated, a downward load is imparted from a chassis to a front fork every time the hydraulic braking pressure increases, to cause the front fork to contract. However, since the contracting action of the front fork is restricted by an anti-dive unit, the load on the front wheel on that area of the tire which is contacting the ground increases immediately to enable the frictional force between the front wheel and the road surface to increase quickly. Accordingly, the variations in the angular deceleration of the front wheel can be minimized.
According to the present invention described above, an anti-dive unit to control the contracting action of the telescopic front fork in accordance with an operation of the front wheel brake is provided on the front wheel-supporting front fork. Therefore, the contracting action of the front fork can be suppressed by the anti-dive unit to quickly increase the grounding load on the front wheel every time the hydraulic braking pressure for the front wheel brake is increased by an anti-lock control unit. This suppresses vertical vibration of the chassis, facilitates front wheel braking, thus minimizes variations in the angular deceleration of the front wheel and improves braking efficiency. | An anti-lock brake system employing an anti-lock control unit between a brake master cylinder and a front wheel brake. The brake system is applied to a damped telescopic front fork and includes an anti-dive device which operates to increase damping force upon application of braking force to the front brake. In a first embodiment, the anti-dive device operates from hydraulic pressure upstream of the anti-lock brake unit. In a second embodiment, reaction force to braking of the wheel is sensed and employed to actuate the anti-dive device. | big_patent |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of provisional patent application Ser. No. 60/219,534, filed on Jul. 20, 2000, the complete disclosure of which is incorporated herein by reference.
TECHNICAL FIELD
[0002] The present invention relates to movable partitions and panels, and, more particularly, to partitions and bulkheads which can be used to separate or insulate cargo during transportation or storage. The invention also relates to segregation of cargo into a plurality of areas that are maintained at different temperatures, commonly known as multi-temperature transport.
BACKGROUND
[0003] Perishable items such as produce and meat are often transported in refrigerated trailers, railcars, or ocean-going containers that can be transported on ships, trains or trucks. Such cargo transport devices are typically equipped with a refrigeration unit which conditions the air inside the cargo space, thereby maintaining desired temperatures and humidities during transportation or storage. Refrigerated trailers, railcars and containers are typically configured so as to enclose a single, large cargo space. Their refrigeration units will accordingly maintain the entire cargo space at the same temperature and humidity unless the cargo area is somehow divided. However, when the perishable cargo does not fill the entire trailer, cooling the entire cargo area is unnecessary and costly. It causes unnecessary strain and wear on the refrigeration unit, increases fuel consumption, raises transportation costs, and lengthens the time necessary to cool the perishable cargo after any temperature aberration.
[0004] Movable partitions and bulkheads having a specialized construction which permits the cargo space of trailers, rail cars, and containers to be readily divided into sections of varying sizes are known. Such bulkheads and partitions have been widely used to separate cargo areas for multi-temperature transport. The structure and configuration of partition and bulkhead systems differ somewhat depending on whether they are being deployed in a trailer, railcar, or container. Partitions currently used in refrigerated truck trailers typically extend from floor to ceiling and are generally comprised of modular wall sections. The modular sections are often mounted in channels or grooves on the trailer floor, held in place by friction, or otherwise mechanically fastened in place so as to compartmentalize trailers and truck bodies for multi-temperature food distribution. The panels are used to divide the trailer or body both longitudinally, along the long axis of the trailer, and laterally, across the width of the trailer. Some partition systems include panels that can be readily removed and placed along the sidewall of the trailer when not in use.
[0005] Insulated bulkheads are panels that extend across the width of a trailer to form separate fore and aft cargo areas. Like partitions, insulated bulkheads allow a refrigerated hauler to carry two or more loads at different temperatures within the same trailer or cargo container. For instance, bulkheads may be used to separate fresh food products from frozen or dry goods. Bulkheads are optionally equipped with walk-through doors similar to those used in partitions to permit ingress to and egress from each conditioned cargo area. Due to the functional similarities between bulkheads and panels, the latter are sometimes referred to as bulkheads.
SUMMARY
[0006] The present invention includes an improved partition system in which at least two panels are independently attached to one or more mounting assemblies such that each panel can be moved independently. In a preferred embodiment, two bulkheads or panels are slidably attached to separate pairs of ceiling-mounted rails in a refrigerated trailer such that each bulkhead or panel can be independently slid toward the front of a trailer or toward the rear of a trailer to define, in cooperation with a removable center partition wall, a plurality of different cargo areas to be maintained at different temperatures. In another preferred embodiment, two panels in the form of half-width bulkheads are releasably secured to one another and independently, slidably attached to ceiling of the trailer such that each half-width bulkhead can be independently raised and lowered with a minimum of fore and aft clearance.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] [0007]FIG. 1 is a perspective view of a trailer containing center partition panels extending along the long axis of the trailer, two horizontal panels, and a rail and trolley system for moving the horizontal panel in the axial direction;
[0008] [0008]FIG. 2 is a plan view of rail system shown in FIG. 1;
[0009] [0009]FIG. 3 is a perspective view of a rail system, trolley assembly slideably attached to the rail system, and a panel hingedly attached to the rail system;
[0010] [0010]FIG. 4 is a perspective view of the rail systems, trolley assembly, and panel after the panel has been raised into a stowed position by a lift mechanism; and
[0011] [0011]FIG. 5 is a perspective view of a lift mechanism.
[0012] Like reference numbers and designations in the various drawings indicate like elements.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0013] Referring to FIG. 1, the trailer 10 encloses a cargo space. The cargo space is separated into a plurality of zones or areas 12 , 14 that can optionally be maintained at different temperatures. Center partition panels 16 extend along the long axis of the trailer and separate the trailer into a left zone 12 and a right zone 14 . The partition panels 16 can have various interfitting modular constructions, as is known in the art. Lateral panels 18 , 20 extend laterally from the center partitions 16 to the left and right trailer walls. The right panel 20 is mounted forward of the left panel 18 , thereby decreasing the volume of the right zone 14 relative to the left zone 12 . Accordingly, the volume of air in the right zone 14 that must be temperature controlled is minimized, which in turn maximizes efficiency and reduces strain on the temperature control system.
[0014] The panels 18 , 20 are slidably attached to the rails 22 with a trolley assembly 24 . The panels are hingedly attached to trolley assembly 24 , and the trolley assemblies are slidably attached to the rails 22 , 23 . The trolley assemblies permit the panels 18 , 20 to be moved in the fore and aft direction and to be “raised” like garage doors and secured to the ceiling when not in use, as shown in FIG. 4 and described in more detail below.
[0015] Those skilled in the art will appreciate that the panel, trolley assembly, and rail system can be implemented in a wide variety of configurations. For instance, the rails may be advantageously installed on the side walls of the trailer, thereby enabling the panels 18 , 20 to open like a standard household door. The mounting assembly is preferably a trolley assembly, but may optionally be replaced with any mechanism that permits rotational, slideable, or hinged movement between the rails and the bulkhead. It is not necessary that the trolley or other mounting assembly permit continuous slidable movement of the bulkhead relative to the rails. Similarly, the rails may be replaced with other receiving members that cooperate with the selected mounting means. It is not necessary that the receiving means be unitary, continuous, or disposed along the long axis of the trailer. For instance, the receiving means can be a series of individual receptacles disposed along the ceiling of the trailer.
[0016] [0016]FIG. 2 is a plan view of the rail assembly shown in FIG. 1. In the depicted embodiment, the receiving members comprise longitudinal rails 22 , 23 having an internal channel adapted to receive a slidable member, preferably a roller. End rails 26 provide a mount for the ends of the longitudinal rails 22 , 23 and also function as a trolley stop. Fixed to the end rails 26 are lift mechanisms 28 and safety chains 30 , the functionality of which is described below. Mounting flanges 31 permit the rails to be fastened to the trailer walls or ceiling with standard fasteners.
[0017] Here again, various modifications can be readily made without departing from the invention. For instance, end rails 26 can be replaced with end caps or can be omitted entirely. The end rails 26 can also be advantageously replaced with half-width movable rails that span and slidably engage the two longitudinal rails on the left 22 and the two longitudinal rails on the right 23 , respectively. Each moveable rail can be fitted with lift mechanisms 28 and safety chains 30 such that each moveable rail can be slid into position relative to each panel before each is lifted into an inoperative or stowed position. Additional longitudinal rails 22 , 23 can be added to accommodate additional panels or panels of different widths.
[0018] [0018]FIG. 3 is a perspective view of the panels 18 , 20 , the trolley assembly 24 , and the rails 22 , 23 . The trolley assembly consists of hinge plates 36 that are fixedly secured to the panels 18 , 20 , a hinge rod 32 , and trolleys 34 . The trolleys 34 serve to suspend the panel from the rails 22 . Trolleys 34 include rollers 35 which permit the bulkhead to be slid into a desired longitudinal position, as shown in FIG. 1. The hinge mechanism 32 , 36 permits the panel to rotate about the hinge rod 32 , as shown in FIG. 4.
[0019] The panel is moved from the position shown in FIG. 3 to the position shown in FIG. 4 by lifting the bottom of the panel 18 up and to the rear of the trailer. The panel 18 is moved fore or aft, as needed, to position the base of the panel 18 proximate to the strap 38 having a hook 40 . The hook 40 is secured to the base 42 of panel 18 , preferably by attachment to a cooperating receptacle. The strap 38 is pulled downward to raise the base 42 of the panel to the ceiling of the trailer. The chains 30 can be attached to the base 18 of the panel to safeguard against unintended release of the panel 18 from the stowed position.
[0020] Referring to FIGS. 3 and 4, the assemblies may be advantageously modified to provide additional or different functionalities. The trolley assembly 32 , 34 , 36 can optionally be replaced with any known mounting mechanism that cooperates with the rails. The mounting means may comprise a post or flange integrally molded into the panel 18 and adapted to be received into the rails 22 . As further examples, the mounting means may include i) a flat slidable member that engages an interior surface of the rail member and is hingedly attached to the bulkhead, ii) an integral, one piece, arcuate tab attached to the top of the bulkhead that can be inserted into one of a plurality of longitudinally arranged receiving means at a predetermined angle such that the tab locks the bulkhead into place as the bulkhead is lowered into a vertical position, iii) a hinge member that releasably locks into one of a plurality of longitudinally disposed receiving means, or iv) any other known mounting mechanism suitable for such mechanical attachment. Likewise, rails 22 , 23 can be replaced with other mechanisms that cooperate with the selected mounting mechanism. For example, the rails 22 , 23 may be replaced with a continuous rail having a plurality of axially disposed apertures for receiving cooperatively configured mounting means or a series of independently mounted receiving members for receiving cooperatively configured mounting means. As noted above, the rail members can optionally be mounted on a vertical surface, such as a trailer wall. Mounting members can thus be selected to enable the bulkheads to swing open like a door, slide in the axial direction in which the rail members are mounted, or be readily removed and reinstalled in another set of receiving members. The foregoing modifications are illustrative only and are not intended to comprise a comprehensive list of all modifications that can be made to the instant apparatus without departing from the invention.
[0021] [0021]FIG. 5 is a detailed view of the strap 38 and cooperating locking mechanism shown in FIG. 4. The strap 38 is positioned over guide pins 44 , 46 . Flange 48 is rigidly attached to cam 50 . In use, the left portion 52 of the strap 38 is attached to the base 42 of the panel 18 either directly or through a suitable cooperating attachment means such as a hook and a mateable receptacle. The right portion 54 of the strap 38 is pulled downward until the panel 18 is in the desired stowage position. Then the flange 48 is forced upward by action of a spring (not shown), thereby forcing cam 50 against strap 38 and locking the strap in place. To lower the bulkhead 18 , the right portion 54 of the strap 38 is pulled downward, which in turn forces flange 48 downward to the depicted, open position. The strap is then free to travel over guide pins 44 , 46 as long as the right portion of the strap is maintained in the depicted, vertical position in substantial tension, which holds flange 48 in the open position. When the end of the strap portion 54 is raised upwards and to the rear of the trailer, spring force causes the flange and cam assembly to rotate counterclockwise, causing the cam 50 to lock the strap 50 in place. Accordingly, the base 42 of the bulkhead 18 is lowered toward the floor of the trailer by holding the strap portion 54 in a vertical position as the strap is pulled over pins 44 , 46 by the weight of the bulkhead.
[0022] The panels 18 and 20 may be advantageously used without center partition panels 16 . For instance, the two panels may be placed side by side and fastened together to make a full-width horizontal bulkhead. A user can advantageously separate the panels, or half-width bulkheads, from one another prior to raising the panels in the manner described above. Further, because each panel is independently and slideably mounted, the amount of rearward clearance needed to raise the panel is reduced significantly. The top of the panel can be slid forward as the bottom is raised rearwardly, which permits the panel to be lifted and stowed even when pallets and cargo are stacked close to the panel.
[0023] The panels of the instant invention may be secured relative to one another with a variety of known means. For instance, the panels can be equipped with cooperating straps and buckles. The panels can alternately be equipped with cooperating channels, grooves, flanges, polymeric seals, or locking pins.
[0024] A number of embodiments of the present invention have been described. Nevertheless, it will be understood that various additional modifications may be made without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the following claims. | An improved bulkhead and partition system in which at least two panels are independently attached to mounting members such that each panel can be moved independently. In a preferred embodiment, two bulkheads or panels are slidably attached to separate pairs of ceiling-mounted rails in a refrigerated trailer such that each bulkhead or panel can be independently slid toward the front of a trailer or toward the rear of a trailer to define, in cooperation with a removable center partition wall, a plurality of different cargo areas to be maintained at different temperatures. | big_patent |
BACKGROUND
1. Field of the Invention
This invention relates generally to the field of fluid handling and liquid chromatography. In particular, the invention is directed toward a novel sanitizable rotary valve that may be used in conjunction with liquid chromatographic columns and sanitary liquid handling systems to separate and/or purify biological macromolecules of importance to the pharmaceutical industry.
2. Description of the Prior Art
Rotary valves have been used for multiple fluid distribution in many different variations. For instance, U.S. Pat. No. 4,808,317 (Berry et al.) is directed to a method and device including a rotary valve for continuously contacting fluids with solid particulates. The design of this fluid distribution valve also allows simulated moving bed ("SMB") counter-current operation. In general, the device operates as follows. A plurality of inlet conduits are provided at the top of a feed box for the purpose of introducing fluid streams into the device for treatment, and a corresponding plurality of outlet conduits are provided at the bottom of the discharge box for removing treated fluid streams. Separator compartments are located so that they rotate past the fluid ports. In normal operation the separator compartments contain a resin or other adsorbent particulate bed which is then sequentially contacted with each fluid stream through the upper and lower timing crown stator ports. Details of the operation of the rotary valve are presented in the '317 patent's FIGS. 5 and 7 through 9. As can be seen from these figures, the rotor and stator must be fully disassembled for cleaning and no provision has been made for sanitizing the contact faces of the rotor and stator surfaces.
U.S. Pat. No. 2,985,589 (D. B. Broughton et al.) is directed to a process and apparatus for continuous simulated counter-current flow to and from the several inlets and outlet streams in relation to beds of solid sorbent. A rotary valve is described for connecting the inlet and outlet fluid streams to the adsorbent bed columns. The process and apparatus are demonstrated by separating a mixture of normal and isohexanes into a stream of relatively pure N-hexane and a secondary product of isohexane. The apparatus comprises a series of 12 beds containing molecular sorbent. The rotary valve used is not sanitizable, and there is no indication that a sanitizable valve face was contemplated.
U.S. Pat. No. 3,268,604 (D. M. Boyd, Jr.) is directed to a fluid flow control system for simulated moving bed processes which include a rotary valve. A multi-port rotary distributing valve is shown in FIG. 1, which is capable of being connected to 24 fluid transfer lines. The valve does not have any sanitizing feature.
U.S. Pat. No. 4,409,033 (LeRoy) is directed to a simulated moving bed separation process for high capacity feed streams, and incorporates a fluid distribution means comprising a rotary valve. Again, no sanitizable aspects are disclosed.
Known non-rotary sanitizable valves include Mieth, U.S. Pat. Nos. 4,757,834 and 4,687,015; and Dolling 4,191,213. Also known are rotary valves granted to Ringo, U.S. Pat. No. 2,706,532 and Pruett, U.S. Pat. No. 3,451,428. The latter two patents disclose no sanitary flushable design.
U.S. Pat. No. 4,921,015 (Sedy) is directed to a rotary vacuum valve having two annular continuous pressurized chambers formed in the sealed face of the rotor. In each chamber are a pair of annular U shaped elastomeric Teflon™ seals expanded by an expansion spring positioned concentrically within the open sides of the seals. These seal assemblies are known as spring-energized TFE lip seals. The stator and rotor move slightly apart upon the application of high pressure to the stator, the lift being sufficient so that the spring-loaded TFE lip seals have a slight contact with the top of the ring, allowing the seal faces to run dry. Thus the arrangement presents a dry low friction seal between the two valve members. No sanitizable or flushable means are provided.
U.S. Pat. No. 4,625,763 (Shick et al.) is directed to a disc-axial multi-port valve for accomplishing the simultaneous interconnection of a plurality of conduits. The valve is comprised of a stator and a rotor, both being comprised of two sections, one being cylindrical and the other being disc-like. FIG. 1 discloses a peripheral seal element 94 retained in a grove in the rotor discular element and urged against the stator transfer face by springs such as 92t. Any fluid leaking from the transverse volume will be retained by this barrier. In addition, in order to prevent cross contamination among the conduits which are interconnected, a flushing fluid may be passed through the transverse volume. Referring again to FIG. 1, flushing fluid may be provided to transverse volume 90 via conduit 95. However, no arrangement is made for pulling apart the faces of the rotor and stator in order to sanitizably flush the faces.
Aseptic diaphragm valve construction, or sanitary valves, are known in the art. These valves are used for aqueous fluids containing or capable of containing microorganisms, or for handling of foods, beverages, or of materials being made into pharmaceuticals or the like. For example, Hoobyar et al. U.S. Pat. No. 5,152,500 disclose an outlet valve wherein a shaft that moves up or down and is covered by a diaphragm bellows thereby engages or disengages a round inlet opening, thereby closing or opening the valve opening surrounding the inlet. The aseptic nature of the valve involves isolation of contaminants by way of a double axial seal and also its self-draining nature. However, the diaphragm valve does not have a multiple-port capability.
U.S. Pat. No. 5,273,075 (Skaer) discloses a diaphragm-based diverter valve with a single inlet and two outlets. The diaphragm engages a weir to open or close a fluid path. Stems are compressed against the diaphragms to close them against the weirs, or opened to create a fluid flow path. According to the patent, dead legs are eliminated in this design.
It is clear that valve designs for sanitizing slider or rotary valves in place without the need for disassembly have not been described in the prior art. In order for the advantages of rotary valve-based separations to be applied to process-scale manufacture of pharmaceuticals, it is mandatory to provide sanitizing means for ensuring removal of contamination within the wetted surfaces of the valve following use, without the need for disassembly. Therefore, there is a need for sanitizable rotary valves which may be intermittently flushed and cleaned, while maintaining the sterile condition of the process system.
SUMMARY OF THE INVENTION
The inventor has designed a completely new type of valve which combines some elements previously found in the valve art, but in addition adds the unique feature of partial (sealed) separation of the rotor-stator faces to allow flushing across the process fluid-contacting surfaces. The partial separation would normally result in sanitizing fluid leaking out of the valve resulting in non-aseptic operation, but a novel diaphragm-like elastomeric seal has been invented which functions to both seal the two faces together in normal use, and also to retain the sanitizing process fluids when the faces are partially separated for cleaning. This design allows the unique sanitary operation of the valve that is disclosed herein,the ability to sanitize in place ("SIP") without disassembling the valve.
The unique operation of the valve is performed by a new type of slider (or rotary) valve shown specifically in a rotary carousel diaphragm valve which has a thermoplastic elastomeric diaphragm integrally molded to form the multiple sealing ports of the rotor face. Ports or grooves molded into the face of the elastomeric diaphragm are positioned to sealably engage grooves or ports in the stator face, and to form sanitary elastomeric tubular ducts leading through the body of the rotor, terminating as elastomeric flanges. These flanges permit direct connection to sanitary piping flanges within the carousel which lead to and from multiple columns or other solid phase bed segments.
To permit periodic sanitization and cleaning of the port sealing faces of the stator and rotor, the external limit of the elastomeric rotor diaphragm is molded to form a flexible wiping lip seal which maintains fluid-tight sealing engagement with the face of the stator even when the rotor is moved orthogonally away from the stator far enough to permit cross flushing of the port sealing faces.
In the preferred embodiment, the required sealing force is minimized by relieving material from either the surface of the stator or from the rotor diaphragm to form port-sealing ledges and adjoining gutters. The gutters may carry a barrier fluid stream which is used to capture and sweep away any process fluid which escapes from the port seals. This feature prevents accumulation of dried material which may damage the sealing faces, and ensures containment of material which might otherwise constitute an environmental hazard to workers in the area.
The invention is directed to a sliding multi-port diaphragm valve having at least two inner surfaces, comprising: a rotor having a body wherein the inner surface is a stator-facing surface, the rotor body having at least a pair of first and second connection ports in fluid connection with rotor ports located on the stator-facing surface, the rotor having attached to the stator-facing surface a sealing means comprising a diaphragm, the diaphragm having a plurality of rotor port sealing means and at least one diaphragm-integral dynamic wipe sealing lip; a stator having a body wherein the inner surface is a rotor-facing surface, the stator body having at least a pair of first and second connection ports in fluid communication with stator ports located on the rotor-facing surface, the stator ports being fluidly connected to their respective connection ports; means for at least one SIP/barrier gutter located on an inner surface of the valve; orthogonal actuating means for incrementally adjusting the rotor perpendicular to its direction of linear motion; fluid connection means for fluidly connecting stator and rotor connection ports to externally located fluid sources and receivers and chromatographic separation devices; and actuating means for moving the rotor body thereby indexing the ports. The SIP/barrier gutter(s) is(are) located either on the diaphragm or on the face of the stator.
The invention is also directed to a multi-port sliding valve of the type having a linear slider, a stator having a plurality of connection ports and associated channels in liquid communication with external fluid sources and separation means, the improvement comprising: a sealing means comprising a diaphragm, the diaphragm having at least one slider port sealing means;
at least one connection port capable of being in fluid communication with a source of SIP fluid, and ports comprising channels through the stator body fluidly connected to their respective connection ports; and
orthogonal separation means for partially separating the slider body from the stator body thereby allowing flushing of sanitizing fluid across the stator face without loss of fluid to the outside.
This invention is also directed to an insert molding process for forming in place a rotary valve diaphragm seal, comprising the steps of: affixing a mold base to the rotor which provides a negative impression of the desired diaphragm surface; capping the ports of the rotor with flange-forming plugs containing channel-forming cores, the cores extending through the connection port channels to seat in holes in the mold base; affixing injection molding equipment to said capped rotor; injecting the rotor with an elastomer suitable for forming a diaphragm seal; curing the diaphragm seal; and removing the mold and caps, thereby exposing a diaphragm molded in place having the desired surface features.
An object of this invention is to provide a sanitizable slider valve in which the port-sealing faces of the slider and stator may be intermittently flushed and cleaned, while maintaining the sterile condition of the process system.
Another object of this invention is to provide a slider valve having a fluid barrier stream which continually purges the external limits of the port-sealing faces to prevent accumulation of dried material and release to the external environment of the solution being processed, while permitting connection of ducts from the ports in the face of the slider to and from multiple solid phase bed segments mounted in an attached carousel.
A further object of this invention is to provide a simple and reliable elastomeric means of ensuring sealing of all ports in a slider valve which is tolerant of imperfect flatness or parallelism of the stator or slider sealing faces, which is not damaged by particulate contamination in the process solution, and which maintains an acceptable sealing integrity over a useful life at least equal to that of typical chromatographic beds used for pharmaceutical manufacturing purification processes.
A further object of this invention is to provide simple means to remove and remotely store the rotor carousel in a sanitary sealed state, to clean and store the stator in a sanitary sealed state, and to permit sequential operation of different rotor carousels on the same stator actuator assembly.
These and other objects and advantages of the invention will become apparent in the following detailed description of the preferred embodiments, in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a drawing of a bench-scale embodiment of the present invention showing a top view of the stator face with the barrier fluid flowpath illustrated by arrows, with rotor not shown.
FIG. 1B is a transverse sectional view along line AA taken through the valve of FIG. 1A and a pair of inlet and outlet fittings, showing the valve while rotating during normal operation, just as stator and rotor ports are aligned, with the right side showing the stator sump drain port.
FIG. 2A is a drawing of the bench scale embodiment of FIG. 1 showing a top view during SIP mode of the stator port sealing ledges, with rotor not shown.
FIG. 2B is a transverse sectional view along line BB of FIG. 2A through both inner and outer barrier/SIP stator ports.
FIGS. 3A-D are a series of sectional close-projections of the rotor and stator ports through conical planes along line CC of FIG. 1B showing the motion of the rotor ports while the rotor is traversing; process solution flow paths are also shown, as is the make-before-break aspect of the invention.
FIG. 4 is a sectional view of the left half of the preferred embodiment of the present invention showing a pilot scale rotor carousel and stator, with all gutters and grooves also molded into the face of the elastomeric rotor diaphragm.
FIG. 5 is a flow schematic diagram of a 5-segment carousel system illustrating the principle of SMB adsorption and separation.
FIG. 6 is a schematic diagram of the Universal Oil Products Sorbex Cascade system for SMB continuous counterflow fractionation.
FIG. 7 is a flow schematic diagram of an SMB size exclusion fractionation separation system similar to that of FIG. 6 with internal liquid recycle implemented on a carousel valve system according to the present invention, with components being resolved shown pictorially.
FIG. 8 is a flow schematic diagram of an SMB ion exchange fractionation separation system with separate flowpaths for adorption, desorption and stripping implemented on a carousel valve system according to the present invention, with components being resolved shown pictorially.
DETAILED DESCRIPTION OF THE INVENTION
Definitions.
The following terms used throughout the specification shall have the following meaning:
"Diaphragm" is used when referring to a generally elastic sealing surface that is urged against a second surface to effect a seal.
"Dynamic wipe sealing lip" is used to refer to a specific integral construction of an elastomeric lip seal used at the sealing edge of the diaphragm. The lip is dynamic in that it has spring action either from a spring insert or inherently.
"Make-before-break" groove is an area on either the slider or stator sealing surface that channels fluid from one channel located in the slider or stator body to another channel. It comprises a groove or ditch cut into the respective surface and terminates at one end in a port or hole that fluidly connects to the channel through the stator or slider body. Make-before-break grooves are commonly known for alleviating the pressure surges that can otherwise stress piping and pumps when fluid flowing under pressure is suddenly diverted from one conduit into another through a valve which interrupts flow continuity.
"SIP" is an acronym for "sanitize-in-place", which describes the action of partially separating the sealing surfaces of the slider (or rotor) and stator and then flushing sanitizing fluid across the sealing faces of the stator and the diaphragm.
A. Preferred Embodiments of the Invention
FIGS. 1-2 show plan views of the stator 300 and transverse sections through the stator and rotor 200 of a bench scale embodiment of the present invention. Stator 300 incorporates actuating and fluid connecting means connected to the bottom portion of stator body 301, which may be formed from ceramic material, or be machined from stainless steel, preferably 316L alloy for corrosion resistance, or from a variety of engineering plastics such as Kel F (polychlorotriflouroethylene or PCTFE), polyphenylsulfone (PPSU), polyphenylene sulfide (PPS), polythalamide (PPA), polyetheretherketone (PEEK), or other high performance materials having good resistance to abrasion and to sodium hydroxide commonly used for cleaning and SIP. With reference to FIG. 1B, the rotor 200 of this embodiment contains 12 pairs (only 1 pair being shown) of first column connection fittings 210 and second column connection fittings 212 engaging mating threads in holes in first rotor connection port 214 and second rotor connection port 215 in the top face of rotor body 201. Rotor body 201 is not normally wetted, thus it may be machined from aluminum or machined or molded from any high temperature engineering thermoplastic resin which will maintain integrity during brief exposure to a secondary insert molding operation at temperatures from about 120° to about 400° F. Suitable materials might include polysulfone, PEEK, or PPS. The fittings shown are commonly available, made from plastic such as polyethylene or polypropylene, with a 1/4-28 UNF thread machined or molded in. These secure the flanged ends of tubes 213, which may be fashioned from Teflon® or Tefzel® or polyethylene or polypropylene or other suitable thermoplastic tubing, and serve to provide a sanitary means to fluidly connect to the inlets and outlets of a plurality of columns mounted in a carousel attached to the rotor, which is not shown in these closeup views.
In practice, any column or solid phase medium may be used. For instance, functionalized ion exchange, hydrophobic interaction, affinity, metal chelate, or size exclusion resin columns may be used to separate biomolecules such as proteins or peptides. Pharmaceuticals may be separated by ion exchange, chiral, or reverse phase media, etc. The specific type of column or media employed or molecules to be separated are not limiting.
The primary objects of this invention are served by the presence of an elastomeric diaphragm 220, which is fashioned as an integral insert molded part of the base of rotor 200. Suitable materials for the diaphragm are thermoplastic elastomers such as styrene-ethylene/butylene-styrene block coploymers, for example the KRATON™ G rubbers (Shell Chemical Co. Houston, Tex.) such as KRATON G 2705. This is an untilled injection moldable elastomeric rubber made and sold for FDA regulated food contact and pharmaceutical applications which is steam sterilizable, inert to sodium hydroxide, and has passed acute toxicity extractables testing including USP XIX, Class VI (121° C.), and the Cumulative Toxicity Index. Other examples of potentially suitable thermoplastic elastomer materials for sealing of a pharmaceutical valve are discussed by Marecki in "Device for Delivering and Aerosol", WO93/22221, which is included by reference here in its entirety.
Diaphragm 220 has a first diaphragm surface 225 which is in contact with the mating bottom surface of rotor body 201, and a second diaphragm surface 226 which is in direct contact with the fluids passing through the valve, and is in selective sealing contact with portions of stator 300 as described below. As shown in FIG. 1B, diaphragm 220 is molded to provide hollow sleeves 223 which extend upward from first diaphragm surface 225 through rotor body 201 to terminate in integral flange gaskets 224 making sanitary sealing fluid connection to ranged column connecting tubes 213. Sleeves 223 are hollow, each containing a sleeve duct 227 which fluidly connects the bore of ranged column connecting tube 213 with its respective first rotor sealing port 228 or second rotor sealing port 229.
Diaphragm 220 also includes first and second integral dynamic wipe sealing lips 221 and 222, which, along with integral flange gaskets 224, form the physical delimitation between first diaphragm surface 225 and second diaphragm surface 226. The dynamic wipe sealing lips have a flexible vee shape with the point angled inward toward the fluid carrying region of the valve, with the axis of the relaxed vee as molded forming an angle of between about 15 to 45 degrees, preferably 40 degrees from the plane of the stator/rotor seal, and the point of the relaxed vee as molded extending about 0.02 to 0.035 inch, preferably 0.028 inch below the mating surface of the stator when the stator is brought into fluid sealing engagement with rotor sliding sealing ports 228 and 229. The resulting fully flexed sealing engagement of lips 221 and 222 when rotor 200 is sealed to stator 300 is shown in FIG. 1A as shaded first and second barrier sealing zones 361 and 365, respectively.
When forming diaphragm 220 as an integral attachment to the base of rotor body 201 by insert molding, rotor body 201 is mounted to a mold base which has a shape to form second diaphragm surface 226 in the inner and outer circumferential limits of first diaphragm surface 225, and which has a plurality of holes at the desired positions of first and second rotor sealing ports 228 and 229. Hollow threaded plugs with ends shaped to form integral flange gaskets 224 and containing channel-forming cores of diameter to form sleeve ducts 227 are screwed into each rotor connection port 214 and 215 such that the cores engage the holes in the mold base. The molten thermoplastic polymer is then injected through a runner preferably located in the center of rotor body 201. When the elastomer has cooled, the threaded plugs and core wires are removed, the mold is opened, and the central runner is sliced away.
Another embodiment of this invention would place the elastomeric diaphragm seal in the opposite orientation, i.e., instead of the diaphragm being adapted for and adhered to the rotor, it may equally be designed to function on the stator face. This embodiment is not shown in the drawings, but given the teachings above, one of ordinary skill in the art would be able to adapt one specific embodiment to the opposite orientation.
With reference to FIG. 1B, the center of rotor 200 has means provided to connect to an actuator shaft 400. An elongated rotor drive slot 240 extends through the center of rotor 200 and loosely engages matching actuator rotating flats 410 machined into the sides of shaft 400. When shaft 400 is periodically rotated by a pneumatic or electric indexing means not shown, but known to those versed in the art, first and second rotor sealing ports 228 and 229 are caused to move while remaining in sliding sealing engagement with the respective stator first port sealing ledge 350 and second port sealing ledge 352. With reference to FIG. 3, this actuation sequence is shown from an initial indexed position of each first rotor sealing port 228 at one end of its respective stator make-before-break groove 370 in FIG. 3A, through a traversing position of FIG. 3B, to a bridging make-before-break position shown in FIG. 3C in which fluid momentarily flows to or from each stator first connection port 310 to or from two adjoining rotor sealing ports 228, through final indexed position seen in FIG. 3D in which each first rotor sealing port 228 has been advanced by one position to the right along stator first port sealing ledge and zone 350.
Again with reference to FIG. 1B, actuator locking nut 420 is secured to the top of actuator shaft 400 by threads (not shown). Nut 420 has a rounded locking nut engagement shoulder 425 which bears on rotor engagement cone 250 machined into the top surface of rotor 200. These elements provide a simple universal swivel joint coupling whereby downward force applied to actuator shaft 400 is uniformly applied both in order to center rotor 200 and to urge second diaphragm surface 226 into sealing engagement with mating portions of stator 300, as seen in FIG. 1B, without regard to exact perpendicularity to shaft 400 or the planarity of surface 226 or the mating portions of stator 300. Means for orthogonal displacement of actuator shaft 400 (not shown) might include springs, pneumatic or hydraulic cylinders, or motor-driven gears. When actuator shaft 400 is moved upward a controlled distance, for example 0.02 inch as seen in FIG. 2B, integral dynamic wipe sealing lips 221 and 222 are permitted to partially relax and flex downward, thereby elevating rotor 200 and permitting second diaphragm surface 226 to break sealing contact between rotor sealing ports 228 (not shown in FIG. 2B) and the mating top surface of stator 300, while maintaining stator fluid sealing contact by the tips of lips 221 and 222, as indicated schematically by the shaded first and second SIP sealing zones 362 and 366 in FIG. 2A.
The orthagonal adjustability of actuator shaft 400 and rotor 200 in the present invention also permits an optimal balance of negligible loss of process fluid and maximum diaphragm life, in excess of that of the carousel column beds. The greater the downward force applied by actuator shaft 400 to second diaphragm surface 226, the larger will be its sealing footprint with first and second port sealing ledges 350 and 352. This sealing area is represented schematically by the shaded zones 350 and 352 in FIG. 2A. Increased sealing force will minimize or eliminate leakage and loss of process fluid from make-before-break grooves 370 into the adjoining barrier fluid gutters described below. However, use of excessive sealing force will also tend to reduce the lifetime of diaphragm 220, which will eventually need to be replaced as grooves become worn into it by the sliding abrasion of first and second port sealing ledges 350 and 352. Depending on the maximum hydraulic pressure being delivered by the process pumps, a relaxed sealing force during rotation may be programmed which permits only a minute lubricating film loss from the process streams, for example not to exceed 0.1% of the total flowrate, into the first, second and mid-barrier fluid gutters 330, 332, and 333 respectively, during the time that the rotor is being rotated as shown in FIGS. 3A-D, typically 1-2 seconds every 1-5 minutes, and then operation may be returned to the maximum programmed sealing force while the rotor remains in the static indexed position.
Again with reference to FIG. 1B, stator 300 has connecting ports and ducts for all fluids entering and leaving valve 100. A plurality of paired first connection ports 310 and second connection ports 312 may be used to program the sequence of flow through the plurality of rotor carousel beds, for example as illustrated schematically in FIGS. 7 and 8. In the embodiment shown in FIGS. 1-3, stator connection ports 310 are each fluidly connected to one end of a plurality of make-before-break grooves 370 spaced equally about the top surface of first and second sealing port ledges 350 and 352. As seen in FIG. 1 and FIGS. 3A and 3D, rotor sealing ports 228 and 229 are normally in fluid tight sealing engagement with the other end of grooves 370. This insures that in normal operation there is no unswept stagnant fluid volume in the process flowpath, which would otherwise cause undesirable mixing and loss of separation. As shown in FIG. 3C, adjoining grooves 370 are separated by delimiters 371 which are narrower than the diameter of rotor sealing ports 228 or 229, so that as the sealing ports are passing from engagement with one groove to the next, there is no interruption of flow. This make-before-break feature is needed to permit continuous operation of even high flow rate pumps without pump-damaging shock waves when the valve is rotated.
In normal operation, all sliding valves are known to release a film of liquid which wets the surface of the sliding seal. Release of this liquid to the environment, or damaging accumulation of dried salt deposits, is prevented in the present invention by the use of an integral barrier fluid flow path. As shown in FIG. 1A, barrier fluid, which might typically be sterile water for injection, enters valve 100 through first SIP/barrier connection port 320, which is mounted in the wall of stator 300 beyond the field of view. Barrier fluid flows circumferentially in both directions through first SIP/barrier gutter 330, which is a stator conduit between first SIP/barrier sealing ledge 360, first port sealing ledge 350 and second diaphragm surface 226. This stream cleans the inner side of first port sealing ledge 350, which will preferably be operated feeding the bed inlets, since it has a smaller surface area to carry the higher pressure loads. As shown in FIG. 1A, barrier fluid leaves first SIP/barrier gutter 330 and enters mid barrier gutter 333 by means of first barrier gutter connection 323. Mid barrier gutter 333 is a stator conduit between first and second port sealing ledges 350 and 352 and second diaphragm surface 226. Barrier fluid flows circumferentially through this channel, cleaning the outer side of first port sealing ledge 350 and the inner side of second port sealing ledge 352. From there, the barrier stream passes through second barrier gutter connection 324 to enter second SIP/barrier gutter 332. This is a stator conduit between second port sealing ledge 352 and second SIP/barrier sealing ledge 364 and second diaphragm surface 226. Barrier fluid cleans the outer side of second port sealing ledge 352 and then leaves stator 300 through second SIP/barrier connection port 322, to be carried to a kill tank or other appropriate disposal means. The size of all the barrier channels is deliberately larger and the barrier flow deliberately slower than that of the process channels to ensure that fluid pressure in the barrier channels will always be lower than fluid pressure in the process stream grooves 370. This prevents solutes in the slowly flowing barrier stream from subsequently reentering any of the process streams.
Secondary containment means for any liquid escaping under rotor diaphragm integral dynamic wipe sealing lips 221 and 222, which bear on first and second SIP/barrier sealing ledges 360 and 364, is also provided in the present invention by first and second sumps 342 and 344. These are deep channels in the face of the stator which connect to sump drain port 340, which may be also plumbed to the kill tank.
The primary object of the present invention is shown in FIG. 2B, which depicts the means by which the valve may be aseptically cleaned and sanitized. In normal operation, upon completion of continuous SMB processing of a batch, all stator connection ports 310 and 312 (FIG. 1B) might optionally first be flushed with a salt or other stripping buffer which is strong enough to desorb moderately tightly bound contaminants, and then a strong sanitizing agent such as 1-5N NaOH is recirculated through all the rotor carousel beds to clean and desorb bound materials and foulants. Following this, actuator shaft 400 and rotor 200 are moved upward as described above to permit crossflushing of first and second port sealing SIP cleaning paths 351 and 353 with sanitizing agent which may be valved into barrier/SIP connection port 320. This cycle may then be repeated with a sterile storage buffer, and the rotor left for storage either in the elevated or relaxed rotational pressure position. These positions are preferred for storage, as they will prevent or minimize compression setting of the elastomeric diaphragm, which would otherwise tend to emboss the pattern of the stator gutters and grooves into second diaphragm surface 226, and to reduce the effective cross-sectional area for flow.
A second embodiment of the present invention is shown in FIG. 4, which is a half transverse section through a pilot scale valve 600. For convenience, the features of valve 600 have been numbered identically, where possible, to those of valve 100, with 500 added. For brevity, only those features which are different will be commented upon.
First and second column connection fittings 710 and 712 are standard 3/8 inch TriClamp™ sanitary tubing connectors with clamps which axially compress the flanges to make a seal against integral diaphragm elastomeric integral flange gaskets 724. Hollow sleeve 723 has a sleeve duct 727 with an approximate bore of 0.2 inch.
The primary difference between embodiments 100 and 600 is that the larger flow channels of pilot scale valve 600, relative to the practical thickness of the diaphragm, permit first and second SIP/barrier gutters 730 and 732 and mid barrier gutter 733, and make-before break grooves 770 of valve 600 to all be molded directly into second diaphragm surface 726. This saves the cost of machining these details into the stator, as deemed necessary for the finer grooves 370 and gutters 330, 332 and 334, which have been placed on the stator to prevent loss of effective cross-sectional area over time due to wear of the diaphragm.
The other feature included in embodiment 600 is elevating spring 930, which is needed to support the greater weight of the rotor carousel. When actuator shaft 900 is relaxed for rotation or elevated for SIP, spring 930 raises rotor 700 to permit unloading or cleaning of first and second port sealing ledges 850 and 852. The use of a spring to transmit upward displacement of actuator shaft 900 in pilot scale embodiment 600 maintains the universal joining aspects of the rotor-to-actuator shaft linkage taught for bench scale valve 100.
B. A Preferred Application of the Invention.
Liquid chromatography is the process of separating a solute dissolved in a flowing or moving solvent from other solutes in the solvent by the differential interaction of the particular solute with a solid phase bed that is packed within a column structure. A solution of liquid phase and solute is flowed or pumped through the solid phase, and the solutes are retained and become separated based on their degree of interaction with the solid phase bed.
In commercial biotechnology separation schemes, some of the resin materials used as adsorption media may cost up to one million dollars a year per separation step. Thus, getting the highest loading, longest life and highest number of cycles possible out of the resin beds can become a key economic consideration. Therefore, regeneration of the adsorbent by desorbing the bound contaminants is crucial to the commercial success of the process.
The adsorption--desorption cycles may be further complicated by the use of flow reversal. Adsorption is done by flowing the feed solution through the resin bed until just before break-through (the point at which the bed is saturated and adsorbate begins to flow through the column). Regeneration can be done in either the same direction as the feed in the adsorption step or in the opposite direction to the feed. When the regeneration fluid (or eluent) flows in the same direction it pushes the adsorbed material ("adsorbate") through the previously clean end portion of the bed. When regeneration occurs by flowing the regenerant in the opposite direction from the original adsorption flow the clean end of the bed stays clean. Flow reversal elution is also often used for adsorption systems because the adsorbate will leave the column as a very concentrated peak. Thus, adsorption columns can serve as concentrators for dilute streams and may be the cheapest way to concentrate.
The productivity of conventional batch elution column chromatography is actually quite low, and the liquid consumption rate is quite high. These limitations arise because only a fraction of the bed is actually used for separation, and because the lower part of the bed may not be fully loaded without loss of product due to breakthrough of the rising concentration front in the emerging mass transfer zone (MTZ). These shortcomings may be overcome through the use of means which cause the solid phase medium to move in a direction countercurrent or opposite to that of the liquid phase, relative to the points of addition and removal of fluid. Actual recirculation of the solid phase has been tried repeatedly, but suffers from loss of the resin by breakage, loss of efficiency due to the increased void volume, and greater complexity.
The use of multiple beds to simulate counter-current operation dates back to the Shanks carousel system for leaching soda ash introduced in England in 1841. Carousel bed arrays have been applied to single component adsorption and ion exchange for many years. As shown in FIG. 5, multiple bed segments connected in series are used for adsorption. The adsorbed concentration in the first segment rises to near saturation before the rising concentration in the MTZ in the last segment begins to emerge in the product stream. By switching all connection ports upward in the direction of fluid flow in the adsorption zone, the carousel simulates downward movement of the adsorbent. The switching rate is timed to follow the MTZ, ensuring maximal loading of each bed segment, and continual supply of a freshly regenerated segment for optimal final removal from the product stream. The valved co-current movement of the fluid ports simulates counter-current movement of the bed, hence the name simulated moving-bed (or SMB).
The first large scale commercial use of simulated moving bed chromatography for fractionation was by Universal Oil Products, as described in U.S. Pat. No. 2,985,589 (Broughton et al. ), who introduced the Sorbex Cascade process for fractionation of hydrocarbons, and later for fructose enrichment from glucose and polysaccharides in corn syrup. The Sorbex system employs a complex rotary valve to move feed and eluent inlets and raffinate and extract outlets cyclically along a multi-segmented column which carries a continuous recirculation of mobile phase in a direction counter to that of the simulated movement of resin caused by the intermittent rotation of the valve (see FIG. 6). To maintain purity, an additional flush loop is needed to remove feed material remaining in the lines between the valve and column segments prior to their use for removing extract slow product as described in U.S. Pat. No. 3,268,604 (Boyd). Eluent savings result from the reduced flow rate needed for a given contact velocity due to the countercurrent motion of the bed segments (internal reflux). Further savings result if external reflux (liquid recyle) is also used, because the recycled liquid phase is blended with eluent and flowed counter to resin bed movement for efficient removal of the more tightly bound components. Weakly bound ("fast") components are moved along with the liquid phase, and taken off in a raffinate stream.
With particular reference to FIGS. 7-8, a specific application of counterflow simulated moving bed liquid chromatography using a multi-port slider (rotary) valve is described. This separation scheme is depicted in a 12-bed rotating carousel arrangement, whereby the beds are fed by the sanitizable rotary valve previously described, and adapted to provide two inputs (eluent, feed) and two outputs (raffinate, extract), with a substantial portion of the eluent being recycled. Feed liquid containing both slow (represented as dots) and fast (larger circles) components is introduced at the feed port, located schematically in the middle of zones I-II (the "differential migration" zone). Eluent is continuously flowed in a direction counter to that of the movement of the columns. The slow components are carried mainly by the bed packing, typically a size exclusion-type resin, and the fast components are carried mainly by the eluent. Thus, they move in opposite directions from the feed port. At the border of zones I and IV, the raffinate stream (largely comprising fast component) is taken off through the raffinate port and led to waste or solvent recapture. At the border of zones II and III, extract (containing largely product slow component) is taken off through a similar port. Flow rates of the inputs and outputs are controlled by pumps relative to the switching rate of the beds so as to create the separations shown in each zone.
FIG. 8 is a schematic representation of a typical ion-exchange salt gradient separation. Here, the plumbing is more complicated and requires four inputs (eluent, wash, feed, strip) and three outputs (extract, raffinate, waste). Feed containing the desired product and undesirable by-products and process artifacts is introduced through a feed port intermediate to zones I and II and is immediately channeled into the "slow capture" zone I. Slow components are adsorbed in zone I, and fast unbound components are swept along with the liquid to be removed as a raffinate stream. As the carousel turns the beds pass upstream of the feed port into a wash buffer zone II. This wash step allows "rectification" of the slow and fast components, flushing away entrained unbound fast components from the bound slow components. The bound slow product continues to move with the beds past the wash inlet port into desorption zone III. Here product is desorbed by a stronger eluent, which may have a different ionic strength and/or pH, and comes off in the extract stream at the boundary of zones II and III. An even stronger eluent is then optionally introduced in zone IV to strip the column and desorb strongly bound species from the bed before the next adsorption cycle. Some stripping solution migrates into zone I with the rotation of the carousel, but this material is diluted and washed away by the raffinate stream containing unbound contaminants. One of ordinary skill in the an will be able to determine the concentrations of the various eluents needed to optimize a particular step gradient.
Although the foregoing invention has been described by way of illustration and example for purposes of clarity and understanding, it will be obvious that certain changes and modifications may be practiced within the scope of the invention, as limited only by the scope of the following appended claims. | A sanitary slider valve shown specifically as a rotary carousel diaphragm valve which has a thermoplastic elastomeric diaphragm integrally molded to form the multiple sealing ports of the rotor/stator interface is described. Ports or grooves molded into the face of the elastomeric diaphragm are positioned to sealably engage grooves or ports in the stator face, and to form sanitary elastomeric tubular ducts leading through the body of the rotor or of the stator, terminating as elastomeric flanges. These flanges permit direct connection to sanitary flared piping flanges within the carousel which lead to and from multiple columns or other solid phase bed segments, or to sanitary flared piping flanges connecting the stator to piping interconnecting the multiple carousel columns to each other and to external supply and collection lines. Sanitary operation is made operable by energized flexible diaphragm wiping lip seals which maintain fluid-tight sealing engagement with the opposing face even when the rotor is lifted off the stator far enough to permit cross flushing of the port sealing faces with sanitizing fluid. The valve permits sanitary operation of advanced chromatographic separations of biopharmaceuticals, including simulated moving bed chromatography. | big_patent |
This is a Continuation-in-Part of U.S. patent application Ser. No. 07/320,420 filed Mar. 8, 1989 now U.S. Pat. No. 4,956,127 issued Sept. 11, 1990.
FIELD OF THE INVENTION
The present invention pertains to gas-liquid contacting trays and, more particularly, an improved valve-tray assembly incorporating directional thrust valves and tray construction for higher efficiency operation.
HISTORY OF THE PRIOR ART
Distillation columns are utilized to separate selected components from a multicomponent stream. Generally, such gas-liquid contact columns utilize either trays, packing or combinations thereof. In recent years the trend has been to replace the so-called "bubble caps" by sieve and valve trays in most tray column designs, and the popularity of packed columns, either random (dumped) or structured packing have been utilized in combination with the trays in order to effect improved separation of the components in the stream.
Successful fractionation in the column is dependent upon intimate contact between liquid and vapor phases. Some vapor and liquid contact devices, such as trays, are characterized by relatively high pressure drop and relatively high liquid hold-up. Another type of vapor and liquid contact apparatus, namely structured high efficiency packing, has also become popular for certain applications. Such packing is energy efficient because it has low pressure drop and low liquid hold-up. However, these very properties at times make columns equipped with structured packing difficult to operate in a stable, consistent manner. Moreover, many applications simply require the use of trays.
Fractionation column trays come in two configurations: cross-flow and counter flow. The trays generally consist of a solid tray or deck having a plurality of apertures and are installed on support rings within the tower. In cross-flow trays, vapor ascends through the apertures and contacts the liquid moving across the tray, through the "active" area thereof. In this area, liquid and vapor mix and fractionation occurs. The liquid is directed onto the tray by means of a vertical channel from the tray above. This channel is referred to as the Inlet Downcomer. The liquid moves across the tray and exits through a similar channel referred to as the Exit Downcomer. The location of the downcomers determines the flow pattern of the liquid. If there are two Inlet Downcomers and the liquid is split into two streams over each tray, it is called a two pass tray. If there is only one Inlet and one Outlet Downcomer on opposite sides of the tray, it is called a single pass tray. For two or more passes, the tray is often referred to as a Multipass Tray. The number of passes generally increases as the required (design) liquid rate increases. It is the active area of the tray, however, which is of critical concern.
Not all areas of a tray are active for vapor-liquid contact. For example, the area under the Inlet Downcomer is generally a solid region. To attempt to gain more area of the tray for vapor/liquid contact, the downcomers are often sloped. The maximum vapor/liquid handling capacity of the tray generally increases with an increase in the active or Bubbling Area. There is, however, a limit as to how far one can slope the downcomer(s) in order to increase the Bubbling Area otherwise the channel will become too small. This can restrict the flow of the liquid and/or restrict the disengagement of vapor retained in the liquid, cause liquid to back up in the downcomer, and thus prematurely limit the normal maximum vapor/liquid handling capacity of the tray. The present invention specifically addresses the problem of restricted disengagement of vapor retained in the liquid.
A variation for increasing the Bubbling Area and hence vapor/liquid handling capacity is a Multiple Downcomer (MD) tray. There is usually a plurality of box shaped vertical channels installed in a symmetrical pattern across the tray to direct liquid onto and Off Of the tray. The downcomers do not extend all the way to the tray below but stop short of the tray by a predetermined distance which is limited by a sufficient space to permit disengagement of any vapor retained in the liquid entering the Exit Downcomer. The downcomer pattern is rotated 90 degrees between successive trays. The bottom of the boxes is solid except for slots that direct the liquid onto the Bubbling Area of the tray below, in between the outlet downcomers of the tray. The MD tray falls into the category of Multipass Trays and is usually used for high liquid rates.
Addressing now select cross flow plate designs, a particularly effective tray in process columns is the sieve tray. This tray is constructed with a large number of apertures formed in the bottom surface The apertures permit the ascending vapor to flow into direct engagement with the liquid that is flowing across the tray from the downcomer described above. When there is sufficient vapor flow upwardly through the tray, the liquid is prevented from running downwardly through the apertures (referred to as "weeping"). A small degree of weeping is normal in trays while a larger degree of weeping is detrimental to the capacity and efficiency of a tray.
Tray efficiency is also known to be improved in sieve type trays by increasing the froth height of the liquid and reducing the backflow of the liquid flowing across the tray. Froth is created when vapor bubbles percolate upwardly through the liquid flowing across the tray. The suspension of the vapor in the liquid prolongs the vapor liquid contact which enhances the efficiency of the process. The longer the froth is maintained and the higher the froth is established, the greater the vapor liquid retention. Higher froth requires smaller vapor bubbles and the formation of the bubbles at a sufficiently slow rate. Likewise, backflow occurs beneath the froth when circulating currents of liquid are established during the liquid flow across the plate. This generally forms along the lateral portions thereof. These currents carry liquid back across the tray in a manner that reduces the concentration-difference driving force for mass transfer. It is the concentration-difference between the vapor and the liquid which enhances the effectiveness of the vapor-liquid contact.
The concentration-difference between the vapor and the liquid can be effected in many ways; some reducing efficiency. For example, as operating pressure increases, descending liquid begins to absorb vapor as it moves across a tray. This is above that normally associated as dissolved gas as governed by Henry's Law and represents much larger amounts of vapor bubbles that are commingled or "entrained" with the liquid. This vapor is not firmly held and is released within the downcomer, and, in fact, the majority of said vapor must be released otherwise the downcomer can not accommodate the liquid/vapor mixture and will flood, thus preventing successful tower operation. This phenomena is generally deemed to occur when operating pressure is such as to produce a vapor density above about 1.0 lbs/cu. ft. and typically amounts to about 10 to 20% of the vapor by volume. For conventional trays, as shown below, the released vapor must oppose the descending frothy vapor/liquid mixture flowing over the weir into the downcomer. In many cases, such opposition leads to poor tower operation and premature flooding.
The technology of gas-liquid contact addresses many performance issues. Certain performance and design issues are seen in the publication "Ballast Tray Design Manual," Bulletin No. 4900-Fifth Edition by Glitsch, Inc., assignee of the present invention. Other examples are seen in several prior art patents, which include U.S. Pat. No. 3,959,419, 4,604,247 and 4,597,916, each assigned to the assignee of the present invention and U.S. Pat. No. 4,603,022 issued to Mitsubishi Jukogyo Kabushiki Kaisha of Tokyo, Japan. A particularly relevant reference is seen in U.S. Pat. No. 4,499,035 assigned to Union Carbide Corporation that teaches a gas-liquid contacting tray with improved inlet bubbling means. A cross-flow tray of the type described above is therein shown with improved means for initiating bubble activity at the tray inlet comprising spaced apart, imperforate wall members extending substantially vertically upwardly and transverse to the liquid flow path. The structural configuration is said to promote activity over a larger tray surface than that afforded by simple perforated tray assemblies. This is accomplished in part by providing a raised region adjacent the downcomer area for facilitating vapor ascension therethrough.
U S. Pat. No. 4,550,000 assigned to Shell Oil Company teaches apparatus for contacting a liquid with a gas in a relationship between vertically stacked trays in a tower. The apertures in a given tray are provided for the passage of gas in a manner less hampered by liquid coming from a discharge means of the next upper tray. This is provided by perforated housings secured to the tray deck beneath the downcomers for breaking up the descending liquid flow. Such advances in tray designs improve efficiency within the confines Of prior art structures. Likewise, U.S. Pat. No. 4,543,219 assigned to Nippon Kayaku Kabushiki Kaisha of Tokyo, Japan teaches a baffle tray tower. The operational parameters of high gas-liquid contact efficiency and the need for low pressure loss are set forth. Such references are useful in illustrating the need for high efficiency vapor liquid contact in tray process towers. U.S. Pat. No. 4,504,426 issued to Karl T. Chuang et. al. and assigned to Atomic Energy of Canada Limited is yet another example of gas-liquid contacting apparatus.
Several prior patents have specifically addressed the tray design and the apertures in the active tray deck area itself. For example, U.S. Pat. No. 3,146,280 is a 1964 patent teaching a directional float valve. The vapor is induced to discharge from the inclined valve in a predefined direction depending on the orientation of the valve in the tray deck. Such valve configurations are often designed for particular applications and flow characteristics. Tray valves with weighted sides and various shapes have thus found widespread acceptance in the prior art. A circular valve structure is shown in U.S. Pat. No. 3,287,004 while a rectangular valve structure is shown in U.S. Pat. No. 2,951,691. Both of these patents issuing to I. E. Nutter, teach specific aspects of vapor liquid contact flow utilizing tray valve systems. Such specialized designs are necessary because vapor-liquid flow problems must be considered for each application in Which a tray is fed by a downcomer. The type of directional flow valve, its orientation, and its predisposition to vapor-liquid flow interaction are some of the issues addressed by the present invention.
It would be an advantage to provide a method of and apparatus for enhanced vapor liquid flow manifesting increased efficiency with a directional thrust valve assembly. Such a valve tray assembly is provided by the present invention wherein a circular tray valve is supported by first and second support legs, oriented into the liquid flow of the tray with the first leg having a wider surface area presented to the flow for diverting the flow therearound. The width of the first leg is substantially less than the diameter of the circular valve aperture, about which the liquid is induced to flow into engagement with the vapor passing therethrough. This valve assembly, when used in conjunction with, and outwardly of, a raised active inlet area further controls initially directed liquid flow from the active inlet area beneath the downcomer.
SUMMARY OF THE INVENTION
The present invention relates to gas-liquid contacting trays and improvements in valve-tray assemblies. More particularly, one aspect of the invention includes an improved tray valve assembly for a process column of the type wherein liquid flows downwardly from a downcomer onto a first tray and thereacross in a first direction upon the active area thereof through which vapor flows upwardly for interaction and mass transfer with the liquid before passing therefrom. The improvement comprises a plurality of apertures formed in the tray having a valve cover mounted thereon. The valve cover is mounted by first and second legs, the first leg being disposed to intercept the flow of liquid across the tray and being wider than the second leg. The legs are mounted to the tray in outwardly slotted portions thereof for defining the orientation of the valve relative to the liquid flow. A number of valve shapes are contemplated by the present invention. These include oval and triangular valves. The valve also includes means for selectively biasing the rear region of the valve upwardly against the flow of liquid for facilitating initial, directionalized vapor flow therethrough.
In another aspect, the invention includes the above described tray valve being formed of a round disc having the first and second legs depending downwardly therefrom. Each of the legs are formed with outwardly extending flange portions for underlying the tray and locking the disc in a floating relationship relative thereto. The valve aperture is circular in shape and the valve legs are disposed in slotted regions disposed outwardly of the circular aperture to prevent the rotation of the valve plate for maintaining the orientation of the valve leg relative to the tray. The biasing means comprises a detent portion formed on the cover of the valve for preventing the surface thereof from resting flush against the tray surface. This design facilitates the initial passage of vapor through the valve. The valves are also comprised of circular discs mounted in and above circular apertures formed in the active tray area. Certain ones of the valves are oriented for the directional thrust of vapor therethrough in a select orientation that is not parallel to the initial flow of liquid thereacross for imparting a directional thrust to the liquid flow. In this manner, the direction of liquid flow can be effected, which further enhances the effectiveness of a raised active inlet area adapted for the discharge of vapor into the liquid coming from a downcomer for passage onto the valve area.
In another aspect, the invention includes an improved method of mixing vapor with liquid discharged from a downcomer of a process column onto an underlying cross-flow tray with the column having a plurality of trays and downcomers spaced vertically one from the other. The improvement comprises forming the tray with a plurality of directional thrust valves disposed therein, the valves being formed of generally circular disc members disposed above circular apertures formed within the tray. The disc members have first and second legs in support thereof, the first leg being wider than said second leg for directing flow therearound, the first and second legs of the valve are disposed along a line perpendicular to the downcomer and generally parallel to the flow therefrom. The step of forming the disc members includes biasing the frontal end of the disc which first engages the liquid flow downwardly relative to the rear end for facilitating the directional flow of vapor therethrough.
In another aspect of the invention, the method described above includes the step of forming the first and second legs of the valve with flange portions outstanding from the disc and engaging the underside of the tray to prevent the lifting of the valve upwardly therethrough. The circular aperture may be formed with first and second notches therein, the first and second notches receiving the first and second legs therein and preventing the rotation of the disc relative to the tray.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention and for further objects and advantages thereof, reference may now be had to the following description taken in conjunction with the accompanying drawings in which:
FIG. 1 is a perspective view of a packed column with various sections cut away for illustrating, diagrammatically, a variety of tower internals and one embodiment of a downcomer-tray assembly constructed in accordance with the principles of the present invention disposed therein;
FIG. 2 is a diagrammatic, side-elevational, cross-sectional view of the improved downcomer-tray assembly of the present invention secured within a process tower and illustrating the flow of liquid and vapor thereacross;
FIG. 3 is a top-plan, diagrammatic view of a prior art tray illustrating problems with the liquid flow thereacross;
FIG. 4 is a perspective view of the downcomer-tray assembly of the present invention, with portions thereof cut away for purposes of clarity;
FIG. 5 is an enlarged, perspective view of one valve of the tray surface disposed adjacent the downcomer of the present invention;
FlG. 6 is an enlarged, side-elevational, cross-sectional view of the valve structure of FIG. 5; and
FIG. 7 is a perspective view of an alternative embodiment of the valve structure of FIG. 5.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring first to FIG. 1, there is shown a fragmentary, perspective view of an illustrative packed exchange tower or column with various sections cut away for showing a variety of tower internals and the utilization of one embodiment of the improved high capacity tray assembly of the present invention. The exchange column 10 of FIG. 1 comprises a cylindrical tower 12 having a plurality of packing bed layers 14 and trays disposed therein. A plurality of manways 16 are likewise constructed for facilitating access to the internal region of the tower 12. Also provided are side stream draw off line 20, liquid side feed line 18, and side stream vapor feed line or reboiler return line 32. A reflux return line 34 is provided atop the tower 10.
In operation, liquid 13 is fed into the tower 10 through reflux return line 34 and side stream feed input feed line 18. The liquid 13 flows downwardly through the tower and ultimately leaves the tower either at side stream draw off 20, or at bottom stream draw off line 30. In its downward flow, the liquid 13 is depleted of some material which evaporates from it as it passes through the trays and packing beds, and is enriched or added to by material which condenses into it out of the vapor stream.
Still referring to FIG. 1, the exchange column 10 is diagrammatically cut in half for purposes of clarity. In this illustration, the column 10 includes a vapor outlet in overhead line 26 disposed atop the tower 12 and a lower skirt 28 disposed in the lower region of the tower around bottom stream takeoff line 30 coupled to a reboiler (not shown). Reboiler return conduit 32 is shown disposed above the skirt 28 for recycling vapor therein upwardly through the trays and/or packing layers 14. Reflux from condensers is provided in the upper tower region 23 through entry conduit 34 wherein reflux is distributed throughout a liquid distributor 36 across upper packing bed 38. It may be seen that the upper packing bed 38 is of the structured packing variety. The regions of the exchange column 10 beneath the upper packing bed 38 are shown for the purpose of illustration and include a liquid collector 40 disposed beneath a support grid 41 in support of the upper structured packing 38. A liquid distributor 42, adapted for redistributing liquid 13, is likewise disposed there-beneath. A second type of distributor 42A is shown below the cut-line 43 and disposed above bed 14. The column 10 is presented with cut-line 43 for illustrating the fact that the tower internals arrangement is diagrammatical only and is provided for referencing various component arrays therein.
Referring still to FIG. 1, an assembly of a pair of trays is also shown for purposes of illustration. In many instances, process columns contain only packing, only trays, or combinations of packing and trays. The present illustration is, however, a combination for purposes of discussion of the overall tower and its operation. A trayed column usually contains a plurality of trays 48 of the type shown herein. In many instances, the trays 48 are valve or sieve trays. Valve trays, comprising the subject matter of the present invention, are herein shown. Such trays comprise plates which are punched or slotted in construction. The vapor and the liquid engage at or along the tray and, in some assemblies, are permitted to flow through the same openings in a counter-current flow arrangement. Optimally, the vapor and liquid flows reach a level of stability. With the utilization of appropriate downcomers, to be described in more detail below, this stability may be achieved with a relatively low flow rate permitting the ascending vapor to mix with the descending liquid. In some embodiments, no downcomers are used and the vapor and the liquid use the same openings, alternating as the respective pressures change. But such is not the case, as shown herein.
In the present embodiment, cross-flow valve trays 48 and 49 and downcomers 53 and 69 are illustrated. Tray 48 is constructed with a plurality of floating valves. Tray 49 also illustrates a raised inlet section 51 beneath downcomer 53, which in accordance with the present invention is substantially planar, formed with a plurality of apertures and which may include a series of momentum deflector barriers, as will be described below. The raised inlet area is described in more detail in U.S. patent application Ser. No. 320,420. Corrosion is another consideration in designing packed towers and for the selection of the material, design, and the fabrication of the tower internals The anatomy of process columns as shown in FIG. 1 is likewise described in more detail in an article by Gilbert Chen, entitled "Packed Column Internals" appearing in the Mar. 5, 1984 edition of Chemical Engineering, incorporated herein by reference.
Referring now to FIG. 2, there is shown a side-elevational, cross-sectional, diagrammatic view of the trays 48 and 49 of FIG. 1 and several design aspects of the present invention. An upper tray 48 comprises a first valved panel. The lower tray 49 is also of generally planar construction across its central active area 52, having a plurality of valves 100 mounted therein, as diagrammatically shown. Liquid 13 travels down a downcomer 53 having a tapered or mitered bottom section 54, from tray 48 disposed thereabove. The tapered section 54 of the downcomer provides a clearance angle for vapor flow from the active inlet area, which clearance angle affords a horizontal flow vector to the vapor vented through raised panel 51. The liquid 13 engages vapor 15 discharged from the raised active panel area 51 beneath the downcomer 53.
Still referring to FIG. 2, the froth 61 extends with a relatively uniform height, shown in phantom by line 63 across the width of the tray 49 to the opposite end 65 where a weir 67 is established for maintaining the froth height 63. The accumulated froth at this point flows over the top of the weir 67 into associated downcomer 69 that carries the froth downwardly into a mitered region 70 Where the liquid accumulates and disperses upon active inlet region 71 therebeneath. Again active inlet region 71 is shown herein diagrammatically for purposes of illustration only. As stated herein, the area of holes and perforations for a single cross-flow plate establish the active length of the plate and the zone in which the froth 61 is established. It should be noted that the present invention would also be applicable to multiple downcomer configurations, Wherein the downcomers and raised, active inlet areas may be positioned in intermediate areas of the trays as also described below. By increasing the total active area by active inlet areas 51 and 71 greater capacity and efficiency is achieved. It is also the manner of flow of the liquid 13 across the tray 49 which, in the present embodiment, is critical to tray efficiency. A flow diagram of a conventional tray will be discussed below for purposes of illustrating the efficiency afforded by the present invention.
Referring now to FIG. 3, there is shown a flow diagram across a conventional tray. The prior art tray 72 is illustrated herein as a round unit having a first conventional downcomer for feeding liquid upon a solid, underlying panel 73 and then to the tray 74. A second downcomer 74A carries liquid away from the tray. A plurality of arrows 75 illustrate the non-uniform flow of liquid 13 typically observed ac ross a conventional prior art tray which does not address the circulation issue. Circular flow is shown to be formed on both sides of the plate lateral to the direction of primary flow. The formation of these retrograde flow areas, or recirculation cells 76, decreases the efficiency of the tray. Recirculation cells 76 are the result of retrograde flow near the walls of the process column and this backflow problem becomes more pronounced as the diameter of the column increases. With the increase in retrograde flow and the resultant stagnation effect from the recirculation cells, concentration-difference driving force for mass transfer between the counter-flowing streams is reduced. The reduction in concentration-difference driving force will result in more contact or height requirement for a given separation in the column. Although back mixing is but a single aspect of plate efficiency, the reduction thereof is provided concurrently with the other advantages hereof. Reference is again made to the plate efficiency discussion set forth in above referenced, co-pending patent application Ser. No. 07/304,942, now U.S. Pat. No. 4,956,127 issued Sept. 11, 1990.
Referring now to FIG. 4, there is shown an enlarged, fragmentary perspective view of a downcomer-tray assembly 99 constructed in accordance with the principles of the present invention. Conventional materials such as stainless steel are utilized, as is well known in the art. The tray 49, as shown herein, is also constructed for placement in the tower 12 by conventional means. In the tower, a feeding downcomer 102, having an inclined face 103, is disposed over a raised inlet region 104 for discharging liquid 3 to tray 49. A weir 82 is disposed on the opposite side of tray 49 whereby a second downcomer is disposed for carrying liquid 13 away from the tray 49. Liquid 13 spills down upon active inlet panel 104 and over upstanding edge 106 onto the tray 49.
Still referring to FIG. 4, there is shown the top surface 108 of raised inlet region 104, constructed with a plurality of apertures 110 diagrammatically shown herein and more fully set forth and described in co-pending U.S. patent application Ser. No. 330,420. The apertures 110 are, in certain areas, partially eliminated or blocked off by barrier strips 101, more fully described in co-pending U.S. application Ser. No. 330,420 filed concurrently herewith. Barrier Strips 101 comprise strips of metal (blanking strips tack welded to the surface 108 in defined patterns. The strips 101 comprise momentum barriers and are seen to be provided in groups 112. Particular momentum barrier group 114 is disposed adjacent the edge of the column 12 with an intermediate group 116 disposed inwardly thereof. The strips 01 of group 116 are seen to be substantially longer than those of group 114 as will be discussed in more detail below.
Referring still to FIG. 4, the groups 112 are sized and positioned in a mirror image of the orifices 118 of feeding downcomer 102. The orifices 118 are likewise provided in groups 120 wherein end group 122 is disposed immediately above momentum barrier group 114. Likewise, intermediate group 124 is disposed directly above momentum barrier group 116. The orifices 118, including groups 122 and 124, form the bottom 126 of downcomer 102 in a slotted configuration that is presented to more precisely distribute the liquid flow onto the surface of the tray 49. This feature provides a more uniform flow without the retrograde problem discussed above. By utilizing select groupings of apertures such as elongated slots 118 which are selectively spaced into groups 120, the discharge from downcomer 102 can be selectively designed by those skilled in the art to enhance uniform flow across the float valve tray described herein and reduce back mixing therein. The reduction of back mixing will increase the concentration-difference driving force for mass transfer between the counter flowing streams of gas and liquid. The directional thrust valves 100 of the present invention facilitates this efficiency in operation.
Referring now to FIG. 5, there is shown a single float valve 100 of the array shown in FIG. 4. The valve 100 of the present embodiment is comprised of a circular disc 130 having securement feet 132 and 134 depending therefrom. The valve 100 is mounted within the surface of tray 49 and disposed above an aperture 136 formed therein. The aperture 136 includes a pair of slotted regions 138 and 139 adapted for receiving the legs 132 and 134, respectively. There are multiple advantages in utilizing this type of floating valve. The orientation of the valve relative to the liquid flow is determined by the spacing of the slotted regions 138 and 139 which allows for not only the upward flotation of the circular disc 130 for the passage of vapor therebeneath, but also the secured orientation thereof.
The size of the valve 100 as shown herein is on the order of one inch in diameter. This size has been shown to be effective in the assembly of a tray having an active area with approximately 25-50 valves per square foot. This valve density per square foot is substantially higher than possible with valves of the conventional size of 11/2" to 17/8" in diameter. Prior art valve density on the order of 12-14 valves per square foot has been common. The increased density is a result of the smaller size of valve 100 and its directional thrust design as herein described, which permits it to be spaced close to adjacent valves as shown. The present invention is a marked advance over prior art designs utilizing larger valves and broader spacing. The efficiency of the tray is thought to be enhanced therefrom.
Still referring to FIG. 5, liquid flow 140 is illustrated flowing in the direction of disc 130. As the liquid flow 140 engages the frontal leg number 132, it is seen to split into bi-directional flow 141 traveling around the circumference of the circular aperture 136. Vapor 15 venting beneath circular disc 130 is represented by arrows 142, which arrows illustrate the biased direction that the vapor 15 has in discharge from beneath the disc 130, due to both the frontal leg number 132 as well as the liquid flow 140 and 141 which is engaged thereby. Both the shape of the hole as well as the discharge of vapor 15 therein works in conjunction with the enlarged frontal member 132 to enforce the split flow 141 as described above. In this manner the float valve 100 is effective in reducing the amount of liquid which is back-trapped, or captured, into the aperture 136. The passage of liquid into the aperture 36 is a distinct disadvantage in that such leakage causes the liquid to bypass the remaining active area of the tray deck. It is most advantageous to have a valve structure that limits the amount of liquid flow that is captured within such apertures.
Referring still to FIG. 5, it may further be seen that the select orientation of the valve induces the vapor flow 142 to be in a direction substantially along the path of the liquid flow 140 to help to further promote the directional flow of liquid. This "directional thrust" aspect of the valve is provided due to the size of the frontal leg 38 and the shape of the aperture 136 intersecting liquid flow in direction 40. Such controlled flow aspects may be utilized to further reduce the problem of retrograde liquid flow discussed above. In some situations the orientation of the valve may be slightly angulated relative to the inlet panel 104 for purposes of initiating a degree of directional thrust from the vapor discharge 142. With the present round aperture 136, the frontal leg 132 may also be substantially narrower than if the aperture 136 were rectangular in shape due to the fact that the arcuate shape facilitates the bi-directional liquid flow 141 therearound. In this particular configuration, the frontal leg 132 comprises approximately 30% of the frontal area of the aperture 136 which engages flow 140. With the 30% frontal area of leg 132, and round hole 136, back-trapping is substantially reduced. Moreover, with the tangential flow diversion 141, the degree of turbulence is substantially reduced as compared to a flat barrier structure that would interrupt the liquid flow and produce turbulence therefrom. It should be noted, however, that shapes other than round, or circular valves may also be used.
Referring now to FIG. 6 there is shown the valve 130 of FIG. 5 in a side elevational, cross section view. Frontal leg member 132 is seen to provide a movable barrier for engaging the liquid flow 140 coming from the raised inlet area 104 (not shown). Vapor 15 ascending through the tray deck 49 is exhausted as represented by arrows 42. The escaping vapor 142 interacts immediately with liquid flow 140 and 141, as described above, the latter liquid flow 141 being diverted around the edges of the circular aperture 136. The liquid flow then continues downstream of rear leg 134 as represented by arrow 144. The directional thrust aspect as described above may also be provided in conjunction with the difference in weight between the frontal leg 132 and rear leg 134. The wider frontal leg 132 will, at low vapor flow rates, allow the rear portion of disc 130 to rise upwardly in direction of arrow 134A. This upwardly initiated movement is further facilitated by the detent, or indentation 135 formed adjacent the rear leg 134. The indentation 135 creates a slight bias in the downstream side of the disc 130 to the upward position. This bias creates a slight angulation for the disc 130 in its resting position. The angulated position serves to initiate the upward movement of the rear leg 134 from the resting position and may incorporate a detent 135 on both sides of leg 134. Detents have been used in the prior art to keep valves from sticking to the tray surface. In the present invention the indentation 135 is utilized in conjunction with the particular valve assembly shown herein for select orientation and preferential biasing of the thrust of the directional thrust valve herein described.
Referring now to FIG. 7 there is shown a stationary upstanding aperture cover 146 having the advantages of the two-leg, slotted orientation, wherein the lead leg 148 is wider than the rear leg 148A. In this alternative embodiment of a stationary cover 146, upstream leg 148 is both angulated and permanently formed in active tray section 149 to facilitate the diversion of liquid flow therearound in the direction of arrows 150. The method of formation may include punching, and/or stamping, which is conventional metal forming technology. This figure is provided for purposes of illustrating one aIternative form of tray aperture covers that may be incorporated in accordance with the principles of the present invention.
It is thus believed that the operation and construction of the present invention will be apparent from the foregoing description. For the method and apparatus shown or described has been characterized as being preferred it will be obvious that various changes and modifications may be made therein without departing from the spirit and scope of the invention as defined in the following claims. | A valve-tray assembly for vapor liquid contact towers. The active area of the tray beneath an upper downcomer is constructed with directional thrust valves facilitating oriented vapor flow therethrough and improving mass transfer efficiency. The valves include first and second support legs oriented into the liquid flow with the first leg having a wider surface area presented to the flow for diverting the flow therearound. The width of the first leg is less than the diameter of the valve aperture, about which the liquid is induced to flow into engagement with the vapor passing therethrough. The valve assembly is used in conjunction with, and outwardly of, a raised active inlet area to further control initially directed liquid flow from the perforated inlet area beneath the downcomer. | big_patent |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates in general to a fluid pressure regulator assembly and, more particularly, to a fluid pressure generator assembly, which produces energy from fluid pressure regulation.
2. Description of the Prior Art
Fluid pressure regulators are well known in the art. Regulators are used to regulate the pressure of liquid propane in an outdoor gas grill, airflow in self-contained underwater breathing apparatuses, and oxygen flow in medical applications. Regulators may be designed for regulating the pressure of virtually any type of fluid. One drawback associated with prior art fluid pressure regulators is the loss of energy between the high-pressure fluid entering the regulator and the low-pressure fluid exiting the regulator. It would be desirable to convert this potential energy into work. Another drawback with prior art systems is that a large reduction in pressure typically requires a more costly regulator. It would, therefore, be desirable to provide an assembly which reduces pressure before reaching a prior art regulator, to allow a more inexpensive regulator to be used. Additionally, single stage regulators often do an inadequate job of modulating large variances in pressure. Accordingly, it would be desirable to find a fluid pressure regulator which reduced the effects of large pressure variances on a fluid output pressure. The difficulties encountered in the prior art discussed herein are substantially eliminated by the present invention.
SUMMARY OF THE INVENTION
In an advantage provided by this invention, a fluid pressure regulator assembly is provided for generating power while regulating a fluid pressure.
Advantageously, this invention provides a fluid pressure regulator assembly for reducing variances in an output pressure as the result of large differences in input pressure.
Advantageously, this invention provides a fluid pressure regulator assembly which is inexpensive to manufacture and maintain.
Advantageously, this invention provides a fluid pressure regulator assembly which is lightweight and portable.
Advantageously, this invention provides a fluid pressure regulator assembly which reduces the size and cost of a regulator needed to regulate the pressure of a fluid.
Advantageously, in a preferred example of this invention, a fluid pressure regulator assembly is provided, comprising means for providing a pressurized fluid, as well as first means and second means for transporting a pressurized fluid. A fluid regulator is coupled to both the first means and second means, and means are coupled between the first means and the fluid regulator for converting a pressurized fluid into mechanical power.
In a preferred embodiment of the present invention, the converting means is a vane pump, coupled into fluid communication with the first means for converting pressurized fluid into movement of the vanes. The movement of the vanes may, thereafter, be converted into rotational and/or electrical energy.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will now be described, by way of example, with reference to the accompanying drawings in which:
FIG. 1 illustrates a front elevation of a gas grill, utilizing the fluid pressure regulator of the present invention;
FIG. 2 illustrates a top elevation in cross-section of the pressure regulator of FIG. 1;
FIG. 3 illustrates a perspective view of the vane motor of the pressure regulator of FIG. 1;
FIG. 4 illustrates a side elevation in cross-section of the vane motor of FIG. 3;
FIG. 5 illustrates a side elevation of an alternative embodiment of the present invention, utilizing dual vane motors; and
FIG. 6 illustrates a side elevation of a diver and diving gear, utilizing the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A fluid pressure regulator assembly is shown generally as ( 10 ) in FIG. 1 . The assembly ( 10 ) comprises a pressurized fluid source, such as a liquid propane tank ( 12 ), such as those well known in the art. Coupled to the compressor is a high-pressure line ( 14 ) which, in turn, is coupled to a vane motor ( 16 ). The vane motor ( 16 ) is coupled by a transfer line ( 18 ) to a fluid regulator ( 20 ). The fluid regulator ( 20 ) is coupled to an output line ( 22 ) which, in turn, is coupled to the burner ( 24 ) of a gas grill ( 26 ). The grill ( 26 ) may be provided with an electrically actuated rotisserie ( 28 ), or any other desired components. As shown in FIG. 1, coupled to the vane motor ( 16 ) is a generator ( 30 ), which is electrically coupled to a battery ( 32 ) which, in turn, is coupled to the rotisserie ( 28 ). The liquid propane tank ( 12 ), high-pressure line ( 14 ), fluid regulator ( 20 ), output line ( 22 ), burner ( 24 ), gas grill ( 26 ), and rotisserie ( 28 ) may be of any type, such as those well known in the art.
As shown in FIG. 2, the fluid regulator ( 20 ) is preferably of the type known in the art, constructed of steel, defining a high-pressure cavity ( 34 ) in fluid communication with a low-pressure cavity ( 36 ). The high-pressure cavity ( 34 ) is coupled to the transfer line ( 18 ), while the low-pressure cavity ( 36 ) is coupled to the output line ( 22 ). The cavities ( 34 ) and ( 36 ) are provided in fluid communication with one another via an opening ( 38 ). Provided through the opening ( 38 ) is a valve stem ( 40 ), designed to completely seal off fluid communication between the high-pressure cavity ( 34 ) and low-pressure cavity ( 36 ), when seated in the opening ( 38 ). Coupled to the valve stem ( 40 ) is a threaded shaft ( 42 ), around which is provided a compressed spring ( 44 ), coupled to a resilient diaphragm ( 46 ). At ambient pressure, the spring ( 44 ) presses the valve stem ( 40 ) downward, opening communication between the high-pressure cavity ( 34 ) and low-pressure cavity ( 36 ). When a fluid ( 48 ), such as liquid propane, enters the high-pressure cavity ( 34 ), the fluid ( 48 ) moves into the low-pressure cavity ( 36 ) through the opening ( 38 ). As the fluid ( 48 ) fills the low-pressure cavity ( 36 ), pressure increases, thereby moving the diaphragm ( 46 ) to lift the valve stem ( 40 ) to begin to close the opening ( 38 ). The valve stem ( 40 ) continues to move until the flow of fluid ( 48 ) across the opening ( 38 ) is reduced when the compressed spring ( 44 ) overcomes the upward pressure on the diaphragm ( 46 ), the valve stem ( 40 ) lowers and increases the flow of fluid ( 48 ) from the high-pressure cavity ( 34 ) to the low-pressure cavity ( 36 ). In this manner, the spring ( 44 ) and diaphragm ( 46 ) continually act to regulate the pressure within the low pressure cavity ( 36 ) and exiting through the output line ( 22 ), as long as the pressure in the high pressure cavity ( 34 ) remains as least as high as the pre-determined pressure for which the spring ( 44 ) and diaphragm ( 46 ) are set. Although the foregoing describes the regulator utilized in the preferred embodiment of the present invention, any regulator, such as the air regulator on a scuba system, or fluid regulator on a welding assembly, may be utilize.
As shown in FIG. 3, the motor ( 16 ) is preferably a vane motor, although it may be any suitable device for translating fluid pressure into mechanical motion. Preferably, as shown in FIGS. 3 and 4, the motor ( 16 ) is provided with a drive shaft ( 52 ), coupled to a casing ( 54 ) by a bushing ( 54 ). The casing ( 54 ) defines a fluid inlet ( 58 ) and a fluid outlet ( 60 ). In the preferred embodiment, the fluid inlet ( 58 ) is coupled into fluid communication with the high-pressure line ( 14 ). (FIGS. 1 - 3 ). The casing ( 54 ) is provided with a hollow interior ( 62 ) in fluid communication with the inlet ( 58 ) and outlet ( 60 ). The hollow interior ( 62 ) is defined by an outer race ( 64 ). Provided within the hollow interior ( 62 ) is an inner drum ( 66 ), which comprises a front plate ( 68 ), a back plate ( 70 ), and a cylindrical inner race ( 72 ). (FIGS. 2 and 3 ). As shown in FIG. 3, the inner race ( 72 ) is provided with a first aperture ( 74 ), a second aperture ( 76 ), a third aperture ( 78 ), and a fourth aperture ( 80 ).
Provided within the inner drum ( 66 ) is a first vane assembly ( 82 ), which includes a first vane ( 84 ) and a third vane ( 86 ), each secured to a lost motion linkage ( 88 ). The first vane ( 84 ) and third vane ( 86 ) are wider than the first lost motion linkage ( 88 ), leaving a first C-shaped cutout ( 90 ) in the first vane assembly ( 82 ). A second vane assembly ( 92 ) is also provided, comprising a second vane ( 94 ), a fourth vane ( 96 ) and a second lost motion linkage ( 98 ). The second vane ( 94 ) and fourth vane ( 96 ) are secured to the second lost motion linkage ( 98 ) in a manner similar to that described above to provide a second C-shaped cutout ( 100 ).
The first vane assembly ( 82 ) and second vane assembly ( 92 ) are constructed in a manner which positions the first vane ( 84 ) and third vane ( 86 ) perpendicular to the second vane ( 94 ) and fourth vane ( 96 ). The first lost motion linkage ( 88 ) is provided within the second C-shaped cutout ( 100 ) of the second vane assembly ( 92 ), and the second lost motion linkage ( 98 ) is provided within the first C-shaped cutout ( 90 ) of the first vane assembly ( 82 ). Preferably, the vane assemblies ( 82 ) and ( 92 ) are constructed of stainless steel and are provided near their ends ( 102 ) with wear resistant tips ( 104 ), constructed of an aluminum nickel bronze alloy, such as those alloys well known in the art to be of superior wear resistance. The tips ( 104 ) are rounded with a tighter radius of curvature than the outer race ( 64 ). The tips ( 104 ) are secured to the vane assemblies ( 82 ) and ( 92 ) by weldments or similar securement means. The first lost motion linkage ( 88 ) defines an interior space ( 106 ) with a width approximately one-half of its length. Provided within this interior space ( 106 ) is a stainless steel drum shaft ( 108 ). Secured around the drum shaft ( 108 ) is a guide block ( 110 ). The guide block ( 110 ) has a square cross-section with a width only slightly smaller than the width of the interior space ( 106 ), defined by the first lost motion linkage ( 88 ). The guide block ( 110 ) is preferably the same depth as the vanes ( 84 ), ( 86 ), ( 94 ) and ( 96 ), and extends from the interior space ( 106 ) of the first lost motion linkage ( 88 ) into an interior space (not shown) defined by the second lost motion linkage ( 98 ). This construction allows longitudinal movement of the vane assemblies ( 82 ) and ( 92 ) relative to the guide block ( 110 ) and drum shaft ( 108 ), but prevents lateral movement in relationship thereto.
The drum shaft ( 108 ) is coupled to a back plate ( 112 ) bolted to the casing ( 54 ). FIGS. 2 and 3 ). As shown in FIG. 4, the drum shaft ( 108 ) is centered within the hollow interior ( 62 ) defined by the outer race ( 64 ). The drive shaft ( 52 ) is positioned slightly higher than the drum shaft ( 108 ), and is coupled to a front plate ( 114 ) bolted to the casing ( 54 ). The drive shaft ( 52 ) is parallel to, but on a different axis than the drum shaft ( 108 ). Since the shafts ( 52 ) and ( 108 ) each rotate on a different axis, the back plate ( 112 ) must be provided with a large, circular aperture ( 116 ), into which is secured a bearing ( 118 ). The bearing ( 118 ) supports the inner drum ( 66 ) against the casing ( 54 ) and allows the drum shaft ( 108 ) to extend out of the casing ( 54 ) and rotate on its own axis. The bearing ( 118 ) also maintains a substantially fluid tight seal to prevent the escape of pressurized fluid out of the casing ( 54 ).
As fluid ( 48 ) enters the fluid inlet ( 58 ) under pressure, the water presses against a face ( 122 ) of the second vane ( 94 ), forcing the inner drum ( 66 ) into a counterclockwise rotation. (FIG. 3 ). When the fourth vane ( 96 ) is closest to a ceiling ( 124 ) of the casing ( 54 ), the majority of the fourth vane ( 96 ) is located within the inner drum ( 66 ). Accordingly, the amount of the fourth vane ( 96 ) exposed to the fluid ( 48 ) is reduced, as is its drag coefficient. A larger drag coefficient would allow the fluid ( 48 ) to force the inner drum ( 66 ) toward a clockwise rotation, thereby reducing the efficiency of the motor ( 16 ).
As the fluid ( 48 ) presses against the face ( 114 ) of the second vane ( 94 ), the second vane ( 94 ) moves along an abrasion plate ( 125 ), preferably constructed of titanium or similar abrasion resistant material, preferably being less than five millimeters and, more preferably, less than one millimeter, while being preferably greater than {fraction (1/100)}th of a millimeter and, more preferably, more than {fraction (1/50)}th of a millimeter from the tips ( 104 ) of the vanes ( 84 ), ( 86 ), ( 94 ) and ( 96 ) as they rotate past. As the second vane ( 94 ) rotates toward the end of the abrasion plate ( 125 ), the first vane ( 84 ) moves toward the abrasion plate ( 125 ) and the fluid ( 48 ) presses against a face ( 126 ) of the first vane ( 84 ), thereby continuing the counterclockwise rotation of the drum shaft ( 108 ) and the inner drum ( 66 ). As the inner drum ( 66 ) continues to rotate, the vanes ( 84 ), ( 86 ), ( 94 ) and ( 96 ) extend and retract relative to the inner drum ( 66 ). The retraction reduces the drag coefficient of the vanes ( 84 ), ( 86 ), ( 94 ) and ( 96 ) when the vanes are near the ceiling ( 124 ) to reduce reverse torque on the inner drum ( 66 ). Conversely, the extension increases the drag coefficient of the vanes ( 84 ), ( 86 ), ( 94 ) and ( 96 ) as the vanes approach the abrasion plate ( 125 ) to allow the fluid ( 48 ) to provide maximum forward torque to the inner drum ( 66 ) through the vanes ( 84 ), ( 86 ), ( 94 ) and ( 96 ). As the vanes ( 84 ), ( 86 ), ( 94 ) and ( 96 ) move past the abrasion plate ( 125 ), the fluid ( 48 ) exhausts through the fluid outlet ( 60 ). Obviously, the motor ( 16 ) can be constructed of any desired material of any suitable dimensions.
As shown in FIG. 1, coupled to the drive shaft ( 52 ) of the motor ( 16 ) is an electrical generator ( 30 ). While the generator ( 30 ) is preferably electric, it may, of course, be of any suitable type of power storage or transmission device known in the art, actuated by heat, mechanical, pneumatic or hydraulic power. As shown in FIG. 1, an electrical cord is coupled to the generator ( 30 ), and is coupled to a battery ( 134 ). The battery, in turn, is coupled to the rotisserie ( 28 ) to provide power when needed. Accordingly, when a valve ( 136 ) on the gas grill ( 26 ) is actuated to draw fluid from the liquid propane tank ( 12 ), the fluid ( 48 ) flows from the liquid propane tank ( 12 ) through the high-pressure line ( 14 ) into the vane motor ( 16 ). The pressure of the fluid ( 48 ) turns the vanes ( 84 ), ( 86 ), ( 94 ) and ( 96 ), thereby driving the drive shaft ( 52 ) and the generator ( 30 ). The generator ( 30 ) thereby sends an electric current to the battery ( 32 ) for use in driving the rotisserie ( 28 ) when desired. From the vane motor ( 16 ), the fluid ( 48 ) having been reduced in pressure, flows through the transfer line ( 18 ) to the fluid regulator ( 20 ), whereby after a further step-down in pressure, the fluid ( 48 ) flows through the output line ( 28 ) to the burner ( 24 ) for use in the grill ( 26 ). Although in the preferred embodiment the vane motor ( 16 ) is used to generate electricity to drive the rotisserie ( 28 ), the vane motor ( 16 ) may, of course, be used to generate electricity for any desired function, or used directly for mechanical power to drive the rotisserie ( 28 ) wheels ( 138 ) provided on the gas grill ( 26 ), or for any other desired utility.
In an alternative embodiment of the present invention, as shown in FIG. 5, a high pressure fluid source such as a compressor ( 140 ) is coupled to a first vane motor ( 142 ) which, in turn, is coupled to a second vane motor ( 144 ). The second vane motor ( 144 ) is coupled to a regulator ( 146 ), such as that described above, and an output line ( 148 ) is also coupled to the regulator ( 146 ). As shown in FIG. 5, the first vane motor ( 142 ) is coupled to a generator ( 150 ) which, in turn,is coupled to a battery ( 152 ). The second vane motor ( 144 ) is coupled to a pulley ( 154 ) which, in turn, is coupled to a belt ( 156 ), used to drive an axle ( 158 ). Although one vane motor ( 142 ) is used in this embodiment to produce electricity, and the other vane motor ( 144 ) is used to produce mechanical work, any number of vane motors may be utilized to produce electricity, and any other number of vane motors may be used to produce mechanical work, if desired. Such an assembly would be particularly well suited to a vehicle driven by a pressurized flammable fluid, such as liquid propane.
In yet another alternative embodiment of the present invention, FIG. 6 illustrates a self-contained underwater breathing apparatus (scuba diver) ( 160 ), coupled to a compressed air tank ( 162 ), such as those well known in the art. Coupled directly to the compressed air tank ( 162 ) is a vane motor ( 164 ), such as that described above. Coupled to the vane motor ( 164 ) is a first stage regulator ( 166 ), such as those well known in the art to reduce pressures from the compressed air tank ( 162 ) on the order of two hundred plus atmospheres to preferably less than ten atmospheres. By running air ( 168 ) through the vane motor ( 164 ), a percentage of the potential energy of this compressed air ( 168 ) can be recovered before being stepped down through the first stage regulator ( 166 ). From the first stage regulator ( 166 ), the air passes through a line ( 170 ) to the second stage regulator ( 172 ), which reduces the pressure to approximately one to five atmospheres. As the scuba diver ( 160 ) breaths, drawing air ( 168 ) from the compressed air tank ( 162 ), the air ( 168 ) drives the vane motor ( 164 ) and the generator ( 174 ), which is coupled to the vane motor ( 164 ).
The generator ( 174 ) may be of any desired construction, but is preferably of the type described above. Coupled to the generator ( 174 ) is a wire ( 176 ) coupled to a headlight ( 178 ), strapped around the head ( 180 ) of the scuba diver ( 160 ). Although in the preferred embodiment the generator ( 174 ) is used to power a headlight ( 178 ), the generator ( 174 ) may, of course, be used to drive any electrical appliance or may be eliminated if it is desired to utilize the vane motor ( 164 ) to generate mechanical work. It should also be noted that the vane motor ( 164 ) may be positioned between the first stage regulator ( 166 ) and second stage regulator ( 172 ), or a plurality of vane motors may be coupled at any desired location to retrieve additional work from the air ( 168 ).
An advantage provided by all of the foregoing embodiments, is that the vane motor extracts work from the pressurized fluid ( 48 ), while reducing the pressure of the pressurized fluid ( 48 ). By performing a portion of the work typically done by a pressure regulator, the assembly ( 10 ) of the present invention allows the use of a smaller or more inexpensive pressure regulator to accommodate the lower pressures.
Although the invention has been described with respect to a preferred embodiment thereof, it is also to be understood that it is not to be so limited, since changes and modifications can be made therein which are within the full intended scope of this invention as defined by the appended claims. For example, it should be noted that any desired motor may be used, including a standard turbine or piston motor, and that any type of generator, including both direct current and alternating current generators, may be utilized in accordance with the present invention. It is additionally anticipated that any number of motors and generators may be used in conjunction with any number of regulators to recover work from a pressurized fluid. It is additionally anticipated that the motor and generator may be of any desired dimensions and design, to accommodate any desired pressures. | A fluid pressure regulator assembly is provided for generating power from a pressurized fluid. A vane motor is coupled between a high-pressure fluid source and a regulator, to extract power from the pressurized fluid and reduce the burden on the fluid regulator. The assembly may be used in association with many devices, including gas grills and self-contained underwater breathing apparatuses. A plurality of vane motors may be provided and generators may be coupled thereto for producing electricity from the pressurized fluid. | big_patent |
BACKGROUND
The invention relates to pallet systems, and in particular, pallet systems that facilitate loading and unloading, and limit the shifting of loaded items.
Pallets are used to ship loads of one or more items that are placed and secured onto pallets. Smaller items may be shipped by packaging the items into larger packaging units, which are then loaded onto the pallets. For example, to ship a large quantity of loose or fragile items such as eggs, the items may be arranged in stackable trays, and the stacked trays are loaded onto the pallet.
A pallet loaded with items is often wrapped for shipment to secure the load, sometimes using rigid end boards.
SUMMARY
In general, in one aspect, the invention features a pallet system for supporting a load of at least one tray having side supports. The pallet system includes a pallet having at least one pair of parallel guide rails raised above a top surface of the pallet, each pair of guide rails configured to be straddled by side supports of a tray.
Advantageous embodiments of the invention include one or more of the following features. The space between each pair of guide rails is substantially open. The guide rails are raised above the level of a weight bearing area of the top surface of the pallet.
The pallet system includes at least one end stop on the top surface of the pallet, each end stop positioned to limit longitudinal movement of a tray loaded on the pallet. The pallet system includes two end plates, configured to be vertically positioned at edges of the pallet at ends of the guide rails. Each end plate has an inside surface shaped to complement contours of the end surfaces of the tray. The pallet system includes end plate holders for securing the first and second end plates. In one example, the end plate holders are notches in the guide rails.
The pallet system includes a pallet base comprising a conventional pallet and a pallet cap securely fitting onto the pallet base to form the pallet, the top surface of the pallet cap forming the top surface of the pallet.
In general, in another aspect, the invention features a stacked pallet, including a pallet, having at least one pair of parallel guide rails raised above its top surface, and trays stacked in layers on the pallet, wherein each tray of the first layer has side supports straddling a pair of guide rails on the pallet.
Advantageous embodiments of the invention include one or more of the following features. The stacked pallet further includes end plates secured to the stacked trays. For example, wrapping secures the end plates to the stacked trays. Adjacent trays in the first layer of the stacked trays are laterally interlocked by the guide rails straddled by the adjacent trays. Within each layer of trays, the trays laterally interlock.
In general, in another aspect, the invention features a method of loading a pallet by providing at least one pair of raised parallel guide rails on a top surface of a pallet and forming a first layer of trays by sliding each tray onto the pallet along a pair of guide rails.
Advantageous embodiments of the invention include one or more of the following features. The method provides at least one end stop on the top surface of the pallet, wherein a tray is slid along a pair of guide rails until its front surface contacts an end stop.
The method forms a stack of trays by repeatedly sliding trays over trays already on the pallet. Trays of the stack are laterally interlocked. The method secures end plates to the stack of trays. When secured, an end plate has an inside surface facing an outside surface of the stack of trays. This inside surface is contoured to complement the outside surface of the stack of trays. Securing end plates to the stack of trays is achieved in one example by wrapping the end plates to the stack of trays.
Among the advantages of the invention are one or more of the following.
The pallet system restricts both the lateral and longitudinal movement of items loaded onto the pallet.
Vertically positioned end plates at both pallet edges at ends of the guide rails further restrict the longitudinal movement of items on the pallet. The pallet system provides enhanced stability when loaded and wrapped.
The pallet allows trays to be slid on and off, and is suitable for automated loading and unloading of the trays.
Other features and advantages of the invention will become apparent from the following description and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1. is a perspective view of a pallet system in accordance with the invention.
FIG. 2 is a perspective view of a pallet cap in accordance with the invention.
FIG. 3 is a cross-sectional view of a loaded pallet system in accordance with the invention.
FIG. 4 is a top detail view of a pallet cap in accordance with the invention.
FIG. 5 is a top view of a loaded pallet in accordance with the invention.
FIG. 6 is a cross-sectional view of a stack of end plates in accordance with the invention.
FIG. 7 is a cross-sectional view of the pallet cap of FIG. 2.
FIG. 8 is a cross-sectional view of a stack of pallet caps in accordance with the invention.
DETAILED DESCRIPTION
Referring to FIG. 1, a pallet system based on a conventional pallet, referred to here as the pallet base 10, is fitted with a pallet cap 20 to provide a pallet in accordance with the invention. Alternatively, the pallet may be a single integrated unit. The pallet system can be used, for example, to ship trays 30 such as those described in pending U.S. Pat. No. 5,816,406, which is incorporated by reference.
FIG. 1 shows in an exploded view the relationship of elements of the pallet system. Several layers of trays are loaded onto the pallet, and the end plates 40a, 40b are respectively positioned at front and back ends of the load to help secure the load of trays 30 to each other and to the pallet, as well as to protect the ends of the trays and provide rigidity to the stack of trays. Typically, though not shown in FIG. 1, the entire load including the end plates 40a, 40b is wrapped with a film, either manually or using a machine and methods such as those described in U.S. Pat. Nos. 5,423,163 and 5,531,327.
The pallet base 10 is a conventional plastic pallet. As shown, a conventional plastic pallet typically has pockets 11 that elevate the top surface of the pallet and provide recesses 12 which allow the pallet to be handled by standard equipment such as forklifts. Because the exact shape and placement of the pallet pockets 11 may vary among pallet models and manufacturers, the pallet cap 20 has pockets 21a, 21b, 21c customized to fit within the pockets 11 of a particular pallet 10.
The pallet cap pockets 21a, 21b, 21c position the pallet cap 20 on the pallet base 10 and provide support for the weight of loads borne by the pallet cap 20. In the configurations shown in FIGS. 1 and 2, the pallet cap pocket 21a extends to the base of the pallet base pocket 11 to provide support and has ribbed walls to provide structural strength. Pallet cap pockets 21b and 21c are provided primarily for positioning the pallet cap 20 on the pallet base 10.
Referring to FIG. 2, the pallet cap 20 has raised, parallel guide rails 22, which are labelled in pairs 22a, 22b, 22c. The number of guide rails 22 may vary, depending on the size and shape of the trays to be loaded. For example, FIG. 2 shows a pallet cap 20 having three pairs of guide rails 22a, 22b, 22c, designed for a load three trays wide, as is illustrated in FIG. 1.
Referring to FIG. 3, each tray 30 has side supports 31. The pairs of guide rails, such as pair 22c, are sized and spaced so that when such a tray is loaded directly on the pallet cap 20, the tray side supports 31 closely straddle a pair of guide rails, thus constraining the lateral movement of the tray 30. The guide rails 22c help to position the tray 30, and as shown, also help to interlock adjacent trays 30. In FIG. 3, the top surface of pallet cap 20 is substantially open between the pair of guide rails 22c, which enables the open space to be used for packing items, in this case, eggs. The guide rails 22c avoid contact with the tray 30 or its load, and are raised above the level of the weight bearing surface of the pallet cap 20.
The arrangement of parallel guide rails allows trays to be loaded onto the pallet by sliding the tray over a pair of guide rails from a front end of the pallet towards a back end, along the direction of the arrow 25 of FIG. 2. The opposite action may be used to unload trays from the pallet. The motion of a tray may be stopped by optional end stops 23, which are positioned at the outer edges of each pair of guide rails 22, towards the back end of the pallet. These end stops 23 limit the longitudinal movement of the trays parallel to the guide rails 22. FIG. 4 provides a more detailed illustration of the positions of the end stops 23.
When a pallet is loaded and ready to be prepared for shipping, the end plates 40a, 40b are vertically positioned at the front and back ends of the pallet as shown in FIG. 1. End plates are vertically positioned in one or more of the notches 24 found at both ends of each guide rail 22 (FIGS. 2 and 4). The notches 24 act as end plate holders for holding the end plates in position.
End plates may provide greater stability to a stack of trays by being shaped to complement the shapes of the trays loaded onto the pallet. For example, FIG. 5 shows a top view of a pallet loaded with trays 30 shaped like those described in U.S. Ser. No. 08/673,698. The end plates 40a, 40b are shaped to complement the contour of the tray edges.
Referring to FIGS. 1 and 5, the end plates 40a, 40b at both ends of the pallet may be substantially identical or interchangeable. The end plates may be narrower than the pallet or load, as shown, and advantageously may be approximately 22 inches wide which allows them to be used with pallets and loads of different widths. For example, a pallet having an industry standard size of 40 inches by 48 inches can support layers having two rows of three trays, where the trays are egg trays of a standard size, such as is disclosed in U.S. Ser. No. 08/673,698. However, pallets of other sizes can be used, including 24 inches by 48 inches (supporting two rows of two trays) and 36 inches by 24 inches (supporting one row of three trays). The end plates 40a, 40b shown in FIGS. 1 and 5 may be used for pallets having any of these dimensions. FIG. 6 illustrates a cross-section of a stack of end plates 40. As shown, the end plates may be shaped such that they nest within one another, which saves space when they are not being used.
The components of the pallet system may be made of various materials. For example, the pallet cap and end plates may be comprised of a plastic such as polypropylene or ABS plastic.
Each component can be manufactured by a variety of methods. For example, FIG. 7 illustrates a cross-section of the pallet cap 20 shown in FIG. 2, created from a sheet of plastic having a thickness approximately in the range of 0.08-0.125 inches. The plastic sheet can be formed by methods such as thermo forming, rotomolding, and injection molding. The same thickness and methods apply to the end plates as well.
Various features of the pallet system may be customized for its intended load. For example, the pallet system exemplified in the figures is customized for supporting egg trays described in U.S. Ser. No. 08/673,698. As shown in FIG. 3, because the trays 30 carry eggs, which are fragile and have rounded bottoms, the side of the guide rails 22 likely to contact the portion of the tray 30 holding an egg have a slanted edge. At their widest point, the guide rails 22 have a width of approximately 0.5 inches, and at their highest point, have a height of approximately 0.25 inches. As shown, the guide rails 22 do not support the weight of the trays and their load. Because the trays 30 are designed to be slid into place on the pallet, end stops 23 are provided at only one end of the guide rails 22, as shown in FIG. 2. Because the trays 30 have honeycomb-shaped edges, the inside surface of the end plate is shaped to complement this surface, as shown in FIG. 5. The raised portions of the end plate have a height of approximately 0.5 inches and a width of approximately 1 inch. As shown in FIG. 6, the end plates 40 are shaped such that they are interchangeable and nest within one another, which saves space when they are not being used. FIG. 8 illustrates that the pallet cap 20 is also shaped to allow several pallet caps to be nested within one another.
Other embodiments are within the scope of the following claims. For example, the pallet may be a single integrated unit rather than a pallet cap fitting onto a conventional pallet. The sizes and positions of pallet cap pockets may vary. The length and height of guide rails, as well as the number of guide rails on a pallet may vary. The shapes and positions of the end stops may vary. For example, end stops may be implemented as a continuous rail across the pallet surface. End stops may be provided at both ends of the pallet if trays are not slid onto the pallet. End plates may have a different width, such as the full width of a pallet. | A pallet system for supporting a load of at least one tray having side supports includes a pallet, having at least one pair of raised parallel guide rails on its top surface, each pair of guide rails configured to be straddled by side supports of a tray. The pallet may be loaded by sliding trays onto the pallet, and lateral movement of a tray loaded onto the pallet is limited by the pair of guide rails that it straddles. | big_patent |
FIELD OF THE INVENTION
[0001] The present invention pertains to the field of aviation aircrafts and particularly relates to an electrical driven flying saucer based on magnetic suspension.
BACKGROUND OF THE INVENTION
[0002] The lift and thrust of a rotary-wing aircraft are formed by a rotary wing rotating at a high speed. The power for the rotation of the rotary wing comes from an engine. The current rotary-wing aircrafts include all kinds of rotary-wing helicopters. The rotary wing and engine are two separate and independent systems and connected with a transmission mechanism.
[0003] Compared with ordinary rotary-wing aircrafts, the particularity of a rotary-wing flying saucer is that the rotary-wing system and its power system need to be installed inside a saucer shell. The internal space of the saucer shell is limited and restricts the structure and layout of the rotary-wing system and its power system. Therefore, the paramount task for the design of a rotary-wing flying saucer is how to make full use of the limited internal space of the saucer shell and design a rotary-wing system and its power system with a compact structure, reasonable layout, small weight, high motive power conversion efficiency and easy manipulation and control.
[0004] When the rotary wing rotates at a high speed in the saucer shell, due to pneumatic vortex, flexibility of the rotary wing, maneuver of the saucer and other factors, the rotary wing and the saucer shell might collide with each other, resulting in failure and even a serious accident. For more information, please refer to Patent CN 1120008A. There exists the foregoing defect. Therefore, one of the important tasks for the design of a rotary-wing flying saucer is how to avoid the contact and friction between the high-speed rotary wing and the interior of the saucer shell, reduce the noise of the rotary wing during high-speed rotation as well as the vibration of the saucer shell and the saucer cabin, raise motive power conversion efficiency, reduce energy consumption and guarantee the operational safety of the rotary wing and the flying saucer. Similar to ordinary rotary-wing aircrafts, reactive torque will be generated when the rotary wing of a flying saucer rotates. For more information, please refer to Patent CN 1114279A. There is the problem that the body of the flying saucer suffers uncontrollable reactive torque. Therefore, how to overcome the reactive torque of the rotary-wing flying saucer is also another important task for the design of a rotary-wing flying saucer.
SUMMARY OF THE INVENTION
[0005] The object of the present invention is to make full use of the limited internal space of the saucer shell and design and construct a rotary-wing flying saucer which has a compact structure, reasonable layout, small weight, high motive power conversion efficiency and owns an easily manipulated and controlled rotary-wing system and its power system.
[0006] The electrical driven flying saucer based on magnetic suspension provided in the present invention comprises a saucer shell, a saucer cabin, a rotary-wing system and a control system, wherein the rotary-wing system is a magnetic suspension electromotive rotary-wing system and comprises magnetic suspension rotary-wing wheels, an electromotive ring, a magnetic suspension shaft and a magnetic suspension guide rail. The electromotive ring, the magnetic suspension shaft and the magnetic suspension guide rail are fixed to the saucer shell. The magnetic suspension rotary-wing wheels are suspended in the space restricted by the electromotive ring, the magnetic suspension shaft and the magnetic suspension guide rail and go around the magnetic suspension shaft under an electromagnetic thrust.
[0007] The magnetic suspension rotary-wing wheels comprise blades, a magnetic suspension inner ring and a magnetic suspension outer ring. The blades are connected between the magnetic suspension inner ring and the magnetic suspension outer ring along the radial direction (X-X) to form an impeller. The magnetic suspension guide rail includes a magnetic suspension inner ring guide rail and a magnetic suspension outer ring guide rail. The magnetic suspension inner ring guide rail comprises an inner ring upper guideway and an inner ring lower guideway. The magnetic suspension outer ring guide rail comprises an outer ring upper guideway and an outer ring lower guideway. The magnetic suspension inner ring of the magnetic suspension rotary-wing wheels surrounds the magnetic suspension shaft in the radial direction (X-X) and is disposed between the inner ring upper guideway and the inner ring lower guideway in the axial direction (Y-Y). The magnetic suspension outer ring of the magnetic suspension rotary-wing wheels is embedded in the electromotive ring in the radial direction (X-X) and disposed between the outer ring upper guideway and the outer ring lower guideway in the axial direction (Y-Y).
[0008] The magnetic suspension inner ring of the magnetic suspension rotary-wing wheels and the magnetic suspension shaft form a repulsive or attractive magnetic suspension radial bearing in the radial direction (X-X) based on the principle that like magnetic poles repel, but opposite magnetic poles attract, and relying on permanent magnets, electromagnets or superconducting magnets, and make the magnetic suspension rotary-wing wheels suspended on the magnetic suspension shaft in the radial direction (X-X). The magnetic suspension inner ring of the magnetic suspension rotary-wing wheels and the magnetic suspension inner ring guide rail form a repulsive or attractive magnetic suspension axial bearing in the axial direction (Y-Y) based on the principle that like magnetic poles repel, but opposite magnetic poles attract, and relying on permanent magnets, electromagnets or superconducting magnets, and make the magnetic suspension inner ring suspended between the inner ring upper guideway and the inner ring lower guideway. The magnetic suspension outer ring of the magnetic suspension rotary-wing wheels and the magnetic suspension outer ring guide rail form a repulsive or attractive magnetic suspension axial bearing in the axial direction (Y-Y) based on the principle that like magnetic poles repel, but opposite magnetic poles attract, and relying on permanent magnets, electromagnets or superconducting magnets, and make the magnetic suspension outer ring suspended between the outer ring upper guideway and the outer ring lower guideway.
[0009] The magnetic suspension rotary-wing wheels of the rotary-wing system, the electromotive ring and the magnetic suspension shaft constitute a magnetic suspension electric engine. The electromotive ring is a stator, the magnetic suspension rotary-wing wheels constitute a rotor, the magnetic suspension shaft is a spindle, the electromotive ring controls the changes of the current flowing in the electromotive ring according to electromagnetic conversion principle and generates a rotating magnetic field along the ring, and this rotating magnetic field generates a magnetic force upon the magnetic field in the magnetic suspension outer ring of the magnetic suspension rotary-wing wheels and pushes the rotation of the magnetic suspension rotary-wing wheels.
[0010] As an improvement of the present invention, two sets of independent magnetic suspension electromotive rotary-wing systems are superposed and mounted coaxially inside the saucer shell in the axial direction (Y-Y), i.e. the upper rotary-wing system and the lower rotary-wing system. Coaxial axial dual magnetic suspension electromotive rotary wings are formed, wherein the upper rotary-wing system and the lower rotary-wing system rotate in reverse directions, adopt reverse inclination directions of blades, can guarantee the coaxial thrusts in the same direction will overcome or offset the reactive torque generated during rotation of the rotary wings and may realize automatic control for self-rotating angles and self-rotating angular velocity of the flying saucer through controlling the velocities and velocity difference of the upper rotary-wing system and the lower rotary-wing system.
[0011] As an alternative improvement of the present invention, two sets of independent magnetic suspension electromotive rotary-wing systems are superposed and mounted coaxially inside the saucer shell in a radial direction (X-X), i.e. the inner rotary-wing system and the outer rotary-wing system. Coaxial radial dual magnetic suspension electromotive rotary wings are formed, wherein the inner rotary-wing system and the outer rotary-wing system rotate in reverse directions, adopt reverse inclination directions of blades, can guarantee the coaxial thrusts in the same direction will overcome or offset the reactive torque generated during rotation of the rotary wings and may realize automatic control for self-rotating angles and self-rotating angular velocity of the flying saucer through controlling the velocities and velocity difference of the inner rotary-wing system and outer rotary-wing system.
[0012] The magnetic suspension electromotive flying saucer designed in the present invention makes full use of the limited internal space of the saucer shell and has a compact design structure, reasonable layout, small weight and high motive power conversion efficiency. Further, its rotary-wing system and power system can be easily manipulated and controlled. The design of the rotary-wing suspension structure avoids the contact and friction between the high-speed rotary-wing and the interior of the saucer shell, reduce the noise of the rotary wing during high-speed rotation as well as the vibration of the saucer shell and the saucer cabin, raise motive power conversion efficiency, lower energy consumption and guarantee the operational safety of the rotary wing and the flying saucer. The two improvement solutions mentioned in the present invention overcome the problem of reactive torque of the rotary wing under the precondition of meeting the foregoing requirements, and can realize stable and easy power control of the rotary wing.
[0013] The present invention is described below in details in connection with the accompanying drawings and embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 : A side-view sectional schematic of an electrical driven flying saucer based on magnetic suspension;
[0015] FIG. 2 : A top-view schematic of an electrical driven flying saucer based on magnetic suspension;
[0016] FIG. 3 : A side-view sectional schematic of coaxial axial dual electrical driven flying saucer based on magnetic suspensions;
[0017] FIG. 4 : A side-view sectional schematic of coaxial radial dual electrical driven flying saucer based on magnetic suspensions;
[0018] FIG. 5 : A schematic of the radial magnetic suspension structure of a rotary-wing wheel;
[0019] FIG. 6 : A schematic of the axial magnetic suspension structure of a rotary-wing wheel;
[0020] FIG. 7 : A schematic of an embodiment of an electric engine.
DETAILED DESCRIPTION OF THE EMBODIMENTS
Embodiment 1
Single-Rotary-Wing Electrical Driven Flying Saucer Based on Magnetic Suspension
[0021] In reference to FIG. 1 and FIG. 2 , the single-rotary-wing electrical driven flying saucer based on magnetic suspension comprises: a saucer shell 1 , a saucer cabin 2 , a rotary-wing system 3 and a control system 4 , wherein the rotary-wing system 3 is a magnetic suspension electromotive rotary-wing system and comprises magnetic suspension rotary-wing wheels 5 , an electromotive ring 6 , a magnetic suspension shaft 7 and a magnetic suspension guide rail 8 ; the electromotive ring 6 , the magnetic suspension shaft 7 and the magnetic suspension guide rail 8 are fixed to the saucer shell 1 ; the magnetic suspension rotary-wing wheels 5 comprise blades 9 , an magnetic suspension inner ring 10 and a magnetic suspension outer ring 11 , the blades 9 are connected to the magnetic suspension inner ring 10 and the magnetic suspension outer ring 11 along the radial direction (X-X) and form an impeller; the magnetic suspension guide rail 8 includes a magnetic suspension inner ring guide rail 12 and a magnetic suspension outer ring guide rail 13 , the magnetic suspension inner ring guide rail 12 comprises an inner ring upper guideway 14 and an inner ring lower guideway 15 , and the magnetic suspension outer ring guide rail 13 comprises an outer ring upper guideway 16 and an outer ring lower guideway 17 ; the magnetic suspension inner ring 10 of the magnetic suspension rotary-wing wheels 5 goes around the magnetic suspension shaft 7 in the radial direction (X-X) and is disposed between the inner ring upper guideway 14 and the inner ring lower guideway 15 in the axial direction (Y-Y); the magnetic suspension outer ring 11 of the magnetic suspension rotary-wing wheels 5 is embedded in the electromotive ring 6 in the radial direction (X-X) and disposed between the outer ring upper guideway 16 and the outer ring lower guideway 17 in the axial direction (Y-Y).
[0022] The magnetic suspension rotary-wing wheels 5 of the electrical driven flying saucer based on magnetic suspension are suspended on the magnetic suspension shaft 7 in the radial direction (X-X) by relying on the magnetic suspension radial bearing formed by the magnetic suspension inner ring 10 and the magnetic suspension shaft 7 ; the magnetic suspension inner ring 10 of the magnetic suspension rotary-wing wheels 5 is suspended between the inner ring upper guideway 14 and the inner ring lower guideway 15 in the axial direction (Y-Y) by relying on the magnetic suspension axial bearing comprising the magnetic suspension inner ring 10 and the magnetic suspension inner ring guide rail 12 ; the magnetic suspension outer ring 11 of the magnetic suspension rotary-wing wheels 5 is suspended between the outer ring upper guideway 16 and the outer ring lower guideway 17 in the axial direction (Y-Y) by relying on the magnetic suspension axial bearing comprising the magnetic suspension outer ring 11 and the magnetic suspension outer ring guide rail 13 .
[0023] The magnetic suspension rotary-wing wheels 5 of the electrical driven flying saucer based on magnetic suspension, the electromotive ring 6 and the magnetic suspension shaft 7 constitute a magnetic suspension electric engine. The electric engine of the electrical driven flying saucer based on magnetic suspension may be designed according to general motor theories, the electromotive ring 6 is a stator, the magnetic suspension rotary-wing wheels 5 constitute a rotor, the magnetic suspension shaft 7 is a spindle, and the structure of an ordinary motor is formed. The electric engine of the electrical driven flying saucer based on magnetic suspension adopts a permanent magnet synchronous engine. Its structure is shown in FIG. 7 .
[0024] The permanent magnet synchronous motor is characterized by a simple and compact structure, low loss, high efficiency and easy manipulation and control. The rotor of a permanent magnet synchronous motor has different structure. For easy description of the principle, this embodiment adopts a simple plug-in structure and pairs of permanent magnets 23 are embedded in the magnetic suspension outer ring 11 to form an exciter field; as a stator, the electromotive ring 6 has a stator core 24 , stator grooves 25 are evenly distributed on the inner circle of the stator core 24 , and 3-phase symmetric stator windings 26 are distributed inside the stator grooves 25 according to a specific rule to form a rotating magnetic field and push the magnetic suspension rotary-wing wheels 5 as a rotor to rotate.
Embodiment 2
Radial Magnetic Suspension Structure of Rotary-Wing Wheels
[0025] An electrical driven flying saucer based on magnetic suspension is provided. Its magnetic suspension rotary-wing wheels 5 are suspended on the magnetic suspension shaft 7 in the radial direction (X-X) according to the magnetic suspension principle.
[0026] As shown in FIG. 5 , a radial magnetic suspension structure of the magnetic suspension rotary-wing wheels 5 is designed, pairs of magnets 22 are placed on the outer edges of the magnetic suspension inner ring 10 and the magnetic suspension shaft 7 of the magnetic suspension rotary-wing wheels 5 , the N poles of the magnets of the magnetic suspension inner ring 10 face the inside and the S poles face the outside; the S poles of the magnets of the magnetic suspension shaft 7 face the inside and the N poles face the outside. According to the principle that like poles of magnets expel, the N pole of the outer edge of the magnetic suspension inner ring 10 and the N pole of the outer edge of the magnetic suspension shaft 7 form a repulsive force. Therefore, the radial magnetic suspension structure of the magnetic suspension rotary-wing wheels 5 as shown in FIG. 5 may realize the suspension of the magnetic suspension rotary-wing wheels 5 in the radial direction (X-X) of the flying saucer.
[0027] Magnets 22 may be made from a homogeneous and evenly distributed permanent magnet material. Ideally, the outer edge of the magnetic suspension inner ring 10 and the outer edge of the magnetic suspension shaft 7 are in an equal-distance state. When the magnetic suspension rotary-wing wheels 5 are disturbed, the outer edge of the magnetic suspension inner ring 10 and the outer edge of the magnetic suspension shaft 7 may deviate from the equal-distance position. Nevertheless, as magnetic field intensity decreases with the increase of the distance and increases with the decrease of the distance, the magnetic suspension inner ring 10 and the magnetic suspension shaft 7 will automatically return to the equal-distance position. Obviously, the radial magnetic suspension structure of the permanent magnet rotary-wing wheel is a natural stable structure.
[0028] Alternatively, the magnets 22 may also be made from an electromagnet material. The radial (X-X) suspension structure of the magnetic suspension rotary-wing wheels 5 designed by using electromagnets may realize good controllability, easy implementation of various advanced control strategies and optimal axial (X-X) magnetic suspension effect of the magnetic suspension rotary-wing wheels 5 .
[0029] The magnets of the magnetic suspension inner ring 10 in FIG. 5 may be changed into a superconducting material. When it is in a superconducting state, according to the Meissner effect, the magnetic suspension inner ring 10 will form a repulsive force with the magnetic suspension shaft 7 , thereby realizing superconducting magnetic suspension. By then, if the magnets on the magnetic suspension shaft 7 are permanent magnets, the superconducting magnetic suspension can also obtain a natural stable structure; if the magnets on the magnetic suspension shaft 7 are electromagnets, the superconducting magnetic suspension can also obtain good controllability and may implement various advanced control strategies based on automation theories.
Embodiment 3
Axial Magnetic Suspension Structure of Rotary-Wing Wheels
[0030] An electrical driven flying saucer based on magnetic suspension is provided. Its magnetic suspension rotary-wing wheels 5 are suspended on the magnetic suspension guide rail 8 in the axial direction (Y-Y) according to the magnetic suspension principle, i.e.: the magnetic suspension inner ring 10 is suspended between the inner ring upper guideway 14 and the inner ring lower guideway 15 , and the magnetic suspension outer ring 11 is suspended between the outer ring upper guideway 16 and the outer ring lower guideway 17 .
[0031] As shown in FIG. 6 , an axial magnetic suspension structure of the magnetic suspension rotary-wing wheels 5 is designed to make the N poles of the magnets of the magnetic suspension inner ring 10 and the magnetic suspension outer ring 11 face upward and the S poles face downward; the S poles of the magnets of the inner ring upper guideway 14 and the outer ring upper guideway 16 face upward and the N poles face downward; the S poles of the magnets of the inner ring lower guideway 15 and the outer ring lower guideway 17 face upward and the N poles face downward. According to the principle that like poles of magnets repel, the N pole at the top of the magnetic suspension inner ring 10 and the N pole at the bottom of the inner ring upper guideway 14 form a repulsive force, and the S pole at the bottom of the magnetic suspension inner ring 10 and the S pole at the top of the inner ring lower guideway 15 form a repulsive force; the N pole at the top of the magnetic suspension outer ring 11 and the N pole at the bottom of the outer ring upper guideway 16 form a repulsive force, and the S pole at the bottom of the magnetic suspension outer ring 11 and the S pole at the top of the outer ring lower guideway 17 form a repulsive force. Therefore, the radial magnetic suspension structure of the magnetic suspension rotary-wing wheels 5 as shown in FIG. 6 may realize the suspension of the magnetic suspension rotary-wing wheels 5 in the axial direction (Y-Y) of the flying saucer. In the radial magnetic suspension structure of the magnetic suspension rotary-wing wheels 5 as shown in FIG. 6 , the magnets may adopt a homogenous and evenly distributed permanent magnet material. Considering weight and other factors, the upper and lower guideways of the magnetic suspension guide rail 8 are designed and different magnetic field intensity is selected to make the magnetic suspension ring located in an approximately equal-distance position of the upper guideway and the lower guideway. When the magnetic suspension rotary-wing wheels 5 vibrate up and down under the influence of air current, the magnetic suspension inner ring 10 and the magnetic suspension outer ring 11 may deviate from the equal-distance position. However, as magnetic field intensity decreases with the increase of distance and increases with the decrease of distance, the magnetic suspension inner ring 10 and the magnetic suspension outer ring 11 will automatically return to the equal-distance position. Thus it may be seen, the axial magnetic suspension structure of the permanent magnet rotary-wing wheels is a natural stable structure. In the radial magnetic suspension structure of the magnetic suspension rotary-wing wheels 5 as shown in FIG. 6 , the magnets may also adopt an electromagnet material. The axial (Y-Y) suspension structure of the magnetic suspension rotary-wing wheels 5 designed with electromagnets may obtain good controllability, easily implement various advanced control strategies and obtain optimal axial (Y-Y) magnetic suspension effect of the magnetic suspension rotary-wing wheels 5 .
[0032] The magnets of the magnetic suspension inner ring 10 and the magnetic suspension outer ring 11 of the magnetic suspension rotary-wing wheels 5 in FIG. 6 may be changed into a superconducting material. When they are in a superconducting state, according to the Meissner effect, the magnetic suspension ring of the magnetic suspension rotary-wing wheels 5 will form a repulsive force with the upper guideway and the lower guideway, thereby realizing magnetic suspension. In this case, if the magnets on the inner magnetic suspension guide rail 12 and the outer magnetic suspension guide rail 13 are permanent magnets, the superconducting magnetic suspension can also obtain a natural stable structure; if the magnets on the inner magnetic suspension guide rail 12 and the outer magnetic suspension guide rail 13 are electromagnets, the superconducting magnetic suspension can also obtain good controllability and various advanced control strategies may be implemented according to the automation theory.
Embodiment 4
Electric Engine
[0033] An electrical driven flying saucer based on magnetic suspension is provided. The magnetic suspension rotary-wing wheel 5 of its rotary-wing system 3 , the electromotive ring 6 and the magnetic suspension shaft 7 constitute a magnetic suspension electric engine. The electric engine of the electrical driven flying saucer based on magnetic suspension may be designed according to the general motor principle, the electromotive ring 6 is a stator, the magnetic suspension rotary-wing wheels 5 constitute a rotor, the magnetic suspension shaft 7 is a spindle and an ordinary motor structure is formed.
[0034] The structure and principle of the electric engine of the electrical driven flying saucer based on magnetic suspension may be same as those of a synchronous motor, an asynchronous motor or a DC motor.
[0035] A typical embodiment of the electric engine of the electrical driven flying saucer based on magnetic suspension is a permanent magnet synchronous engine. Its schematic structure is as shown in FIG. 7 .
[0036] The permanent magnet synchronous motor is characterized by a simple and compact structure, low loss, high efficiency and easy manipulation and control. The rotor of the permanent magnet synchronous motor may have a different structure. For easy description of the principle, this embodiment adopts a simple plug-in structure and pairs of permanent magnets 23 are embedded in the magnetic suspension outer ring 11 to form an exciter field; the electromotive ring 6 as a stator has a stator core 24 , stator grooves 25 are evenly distributed on the inner circle of the stator core 24 , and the 3-phase symmetric stator windings 26 are distributed inside the stator grooves 25 according to a specific rule to form a rotating magnetic field and push the magnetic suspension rotary-wing wheels 5 as a rotor to rotate.
Embodiment 5
Coaxial Axial Dual Magnetic Suspension Electromotive Rotary Wings
[0037] An electrical driven flying saucer based on magnetic suspension adopts coaxial axial dual magnetic suspension electromotive rotary-wing systems when it improves its rotary-wing system to overcome the reactive torque of the rotary wings. The coaxial axial dual magnetic suspension electromotive rotary-wing systems include an upper rotary-wing system 18 and a lower rotary-wing system 19 . The upper and lower rotary-wing systems adopt a same structure and both comprise magnetic suspension rotary-wing wheels 5 , electromotive rings 6 , magnetic suspension shafts 7 and magnetic suspension guide rails 8 .
[0038] During work, the respective electromotive rings of the upper and lower rotary-wing systems generate rotating magnetic fields in reverse directions, which drive respective magnetic suspension rotary-wing wheels to rotate in reverse directions. The upper and lower magnetic suspension rotary-wing wheels maintain a same absolute rotation speed and may offset respective reactive torques and maintain stability of the saucer shell; the upper and lower rotary-wing systems provide lift or forward thrust in the same time and greatly enhance the power performance of the flying saucer.
Embodiment 6
Coaxial Radial Dual Magnetic Suspension Electromotive Rotary Wings
[0039] An electrical driven flying saucer based on magnetic suspension adopts coaxial radial dual magnetic suspension electromotive rotary-wing systems when it improves its rotary-wing system to overcome the reactive torque of the rotary wings. The coaxial radial dual magnetic suspension electromotive rotary-wing systems include an inner rotary-wing system 20 and an outer rotary-wing system 21 . The upper and lower rotary-wing systems adopt a same structure and both comprise magnetic suspension rotary-wing wheels 5 , electromotive rings 6 , magnetic suspension shafts 7 and magnetic suspension guide rails 8 .
[0040] During work, the respective electromotive rings of the inner and outer rotary-wing systems generate rotating magnetic fields in reverse directions, which drive respective magnetic suspension rotary-wing wheels to rotate in reverse directions. The inner and outer magnetic suspension rotary-wing wheels maintain a rated absolute speed difference and may offset respective reactive torques and maintain stability of the saucer shell; the inner and outer rotary-wing systems provide lift or forward thrust in the same time and enhance the power performance of the flying saucer.
[0041] The coaxial radial dual magnetic suspension electromotive rotary-wing systems adopt dual rotary-wing systems placed on a same plane, so the air current disturbance between the two magnetic suspension rotary-wing wheels is reduced significantly and the controllability and stability of the rotary-wing systems are significantly improved. | A magnetic suspension electric rotor flying saucer comprises: a saucer shell ( 1 ), a saucer cabin ( 2 ), a rotor system ( 3 ), and a control system ( 4 ). The rotor wing system is a magnetic suspension electric rotor wing system ( 3 ) composed of a magnetic suspension rotor wing wheel ( 5 ), an electrodynamic ring ( 6 ), a magnetic suspension shaft ( 7 ) and magnetic suspension lead rails ( 8 ). The electrodynamic ring ( 6 ), the magnetic suspension shaft ( 7 ) and the magnetic suspension lead rails ( 8 ) are fixed on the saucer shell ( 1 ). The magnetic suspension rotor wing wheel ( 5 ) is suspended in space limited by the electrodynamic ring ( 6 ), the magnetic suspension shaft ( 7 ) and the magnetic suspension lead rails ( 8 ) and rotates around the magnetic suspension shaft ( 7 ) by the electromagnetic thrust. | big_patent |
FIELD OF THE INVENTION
The present invention concerns streptavidin muteins, a process for the production of such proteins by means of recombinant DNA technology as well as the use of these streptavidin muteins for the isolation, purification and determination of biological substances, in particular of other recombinant proteins.
BACKGROUND AND PRIOR ART
Nowadays the biotin/streptavidin system is a generally known binding system in molecular biology the importance of which has increased considerably in recent years and which is used in various fields of application. In doing so one utilizes the specific affinity between biotin and streptavidin which, together with an affinity constant of the order of 1013, is one of the most stable known non-covalent interactions.
Important conventional applications are for diverse separation and detection methods usually using biotinylated enzymes or/and antibodies in various variations. Examples are for example ELISA, Western blot etc. A prerequisite for such methods is that the reagent or enzyme used in a biotinylated form in the method must firstly be obtainable in a pure form in order to be able to carry out the biotinylation which takes place in a chemical reaction.
However, for certain applications a biotinylation is not possible or at least not in a simple manner such as for example when detecting and purifying recombinantly produced proteins which have previously not yet been isolated. Therefore in the past methods for modifying the biotin/streptavidin system have been sought in order to extend its range of application.
A successful approach has been to produce peptide ligands which also have a specific binding affinity for streptavidin. Suitable peptide ligands and corresponding fusion proteins are disclosed in DE-OS 42 37 113. The advantage of these peptide ligands compared to biotin is essentially that their coding sequence is linked at the DNA level with the gene of a desired protein and can subsequently be coexpressed together with that of the protein by which means a recombinant protein labelled with the peptide ligand, i.e. fused thereto, is formed. Due to the small size of the peptide ligands and the fact that they can be attached to the N- or C-terminus of the desired protein, i.e. in areas which often are not of major importance for the structure and biochemical function of the protein, it is generally also not necessary to again cleave off the peptide ligand after its isolation and before using the protein for other purposes so that this also results in a more economical process. Indeed no case is yet known in which a cleavage would have been necessary. If nevertheless cleavage should be necessary, this can be accomplished by inserting a protease cleavage site between the binding peptide and protein sequence.
Such peptide ligands which are suitable are described in detail for example in Schmidt and Skerra, Protein Eng. 6 (1993), 109-122 and J. Chromatogr. A 676 (1994), 337-345 as well as in Schmidt et al., J. Mol. Biol. 255 (1996), 753-766.
Advantages of the streptavidin peptide ligand system are that the purification of recombinant proteins becomes possible at all and that this purification can be achieved for example by affinity chromatography under very mild elution conditions since the bound peptide ligand as part of the recombinant protein is displaced competitively by biotin or derivatives thereof. In addition the peptide ligand enables the recombinant protein to be for example detected by Western blot, ELISA or by immune microscopy using suitable streptavidin conjugates.
A disadvantage of this system has previously been its relatively low affinity. An affinity constant of 2.7×10 4 M -1 has been determined by means of isothermal titration calorimetry for the complex between streptavidin and the peptide ligand referred to as strep-tag (Ala Trp Arg His Pro Gln Phe Gly Gly (SEQ ID NO: 1)). Although there were indications that the binding could be somewhat stronger for a fusion protein containing the peptide ligand, it is desirable to have a system with a fundamentally improved affinity.
Hence the object of the invention was to optimize the streptavidin/peptide ligand system with regard to binding strength.
After initial experiments had been carried out to further optimize the sequence of the peptide ligand, it had to be assumed that the peptide ligand according to DE-OS-4237113 already apparently represented an optimum and thus this approach was less promising.
Once the crystal structure of the streptavidin/peptide ligand complex was available in high resolution, a better understanding was gained of the molecular interactions and the structural characteristics (Schmidt et al. (1996), supra) but no clear information could be obtained from these structural data on whether and in which manner a modification of the peptide sequence or of streptavidin could be carried out in a rational manner to improve the affinity and hence to achieve the initial objective.
In an evolutionary research approach it has now been surprisingly found that the binding affinity for the streptavidin/peptide ligand system can be improved by mutation in the region of the amino acid positions 44 to 53 of streptavidin.
SUMMARY OF THE INVENTION
Thus a subject matter of the present invention is a polypeptide selected from muteins of streptavidin which is characterized in that it (a) contains at least one mutation in particular an amino acid substitution in the region of the amino acid positions 44 to 53 with reference to the amino acid sequence of wild type-(wt)-streptavidin (nomenclature according to Argarana et al., Nucleic Acids Res. 14 (1986), 1871-1882) and (b) has a higher binding affinity than wt-streptavidin for peptide ligands comprising the amino acid sequence Trp-Xaa-His-Pro-Gln-Phe-Xaa-Xaa (SEQ ID NO: 16) in which X represents an arbitrary amino acid and Y and Z either both denote Gly or Y denotes Glu and Z denotes Arg or Lys.
The streptavidin muteins of the present invention can correspond to the amino acid sequence of wt-streptavidin outside of the region of the amino acid positions 44 to 53. On the other hand the amino acid sequence of the muteins according to the invention can also be different to the wt-streptavidin sequence outside the region of the amino acids 44 to 53. Such variants of th e streptavidin sequence include naturally occurring as well as artificially produced variants and the modifications are understood as substitutions, insertions, deletions of amino acid residues as well as N- or/ and C-terminal additions.
The term "higher binding affinity" refers within the sense of the present application to a complex composed of a streptavidin mutein according to the invention and a peptide ligand according to DE-OS-4237113 and can be determined by standard methods such as ELISA, fluorescence titration or titration calorimetry. The binding affinity determined in this manner is specified by parameters such as affinity and dissociation constants or thermodynamic parameters. The increase of the binding affinity which is obtained with a streptavidin mutein modified according to the invention within the region of the amino acid positions 44 to 53 compared to the corresponding unmodified streptavidin is in general at least a factor of 5, preferably at least a factor of 10 and more preferably at least a factor of 20. Preferred streptavidin muteins according to the invention comprise at least one mutation in the region of the amino acid positions 44 to 47.
Preferred streptavidin muteins according to the invention are derived from streptavidin variants which are shortened at the N- or/and the C-terminus. The minimal streptavidins which are N- and C-terminally shortened known from the state of the art are particularly preferred. A preferred polypeptide according to the present invention comprises outside of the mutagenized region the amino acid sequence of a minimal streptavidin which begins N-terminally in the region of the amino acid positions 10 to 16 and terminates C-terminally in the region of the amino acid positions 133 to 142. The polypeptide particularly preferably corresponds to a minimal streptavidin outside of the mutation region which comprises an amino acid sequence from position Ala 13 to Ser 139 and optionally has an N-terminal methionine residue. In this application the numbering of amino acid positions refers throughout to the numbering of wt-streptavidin (Argarana et al., Nucleic Acids Res. 14 (1986), 1871-1882).
Streptavidin muteins according to the invention that are especially preferred are characterized in that at position 44 Glu is replaced by a hydrophobic aliphatic amino acid e.g. Val, Ala, Ile or Leu, at position 45 an arbitrary amino acid is present, at position 46 an aliphatic amino acid and preferably a hydrophobic aliphatic amino acid is present or/and at position 47 Val is replaced by a basic amino acid e.g. Arg or Lys and in particular Arg. Streptavidin muteins in which the aliphatic amino acid at position 46 is Ala i.e. there is no substitution at position 46, or/and in which the basic amino acid at position 47 is Arg or/and in which the hydrophobic aliphatic amino acid at position 44 is Val or Ile have a particularly high affinity for the peptide ligand with the sequence WSHPQFEK (strep-tag II) described by Schmidt et al., Supra.
Specific examples of streptavidin muteins according to the invention have the sequences Val 44 -Thr 45 -Ala 46 -Arg 47 (SEQ ID NO: 6) or Ile 44 -Gly 45 -Ala 46 -Arg 47 (SEQ ID NO: 8) in the region of the amino acid positions 44 to 47.
For practical considerations it is desirable to have a further ligand which, due to a higher binding affinity or/and when present at higher concentrations, can detach the binding of the previously defined peptide ligands (according to DE-OS-4237113) from the streptavidin mutein according to the invention. In this manner it is possible to release bound peptide ligands or proteins to which a peptide ligand is fused under very mild elution conditions. Hence under this aspect the present invention concerns those streptavidin muteins according to the invention whose binding affinity for peptide ligands is such that they can be competitively eluted by other streptavidin ligands e.g. biotin, iminobiotin, lipoic acid, desthiobiotin, diaminobiotin, HABA (hydroxyazobenzene-benzoic acid) or/and dimethyl-HABA. The use of coloured substances such as HABA has the advantage that the elution can be checked visually.
However, irrespective of this, the binding affinity of the streptavidin mutein for peptide ligands is, as defined above, higher than that of the underlying wt-streptavidin. The binding affinity expressed as an affinity constant is thus greater than 2.7×10 4 M -1 with reference to the peptide ligand Ala Trp Arg His Pro Gln Phe Gly Gly (also referred to as strep-tag in the following) shown in SEQ ID NO:1 and greater than 1.4×10 4 M -1 with reference to the peptide ligand Trp Ser His Pro Gln Phe Glu Lys (also referred to as strep-tag II in the following) shown in SEQ ID NO:2 i.e. greater than the published values for the complex formation of the respective peptide ligands with wt-streptavidin (within the limits of error). In general the affinity constant for the strep-tag II is at least a factor of 10, preferably a factor of 10 to 200 higher than the respective values for wt-streptavidin.
It may be preferable for certain detection methods to use the streptavidin muteins of the present invention in a labelled form. Accordingly a further subject matter of this invention is a polypeptide according to the invention which is characterized in that it carries at least one label. Suitable labelling groups are known to a person skilled in the art and comprise the usual radiolabels, fluorescent labels, luminescent labels and chromophore labels as well as substances and enzymes which generate a substrate that can be determined in a chemical or enzymatic reaction. In this connection all labels known for wt-streptavidin can also be coupled to the streptavidin muteins according to the invention.
A further aspect of the present invention concerns a nucleic acid which comprises a sequence coding for the streptavidin. Such a nucleic acid is optionally operatively linked to a sequence coding for a signal peptide and, in a particular embodiment, the sequence coding for the signal peptide is the sequence for the OmpA signal peptide. Moreover it is also possible to use other signal peptides and this may even be preferable especially depending on the expression system or host cell used. A large number of such signal peptides are known in the state of the art and will not be elucidated in detail here. However, cytoplasmic expression is preferred i.e. with a start methionine instead of the signal sequence (cf. Schmidt and Skerra (1994), supra).
A further aspect of the present invention concerns a vector which contains at least one copy of an aforementioned nucleic acid in an operatively functional environment. An operatively functional environment is understood as those elements which enable, favour, facilitate or/and increase the expression, i.e. transcription or/and a subsequent processing, of the mRNA. Examples of such elements are promoters, enhancers, transcription initiation sites and termination sites, translation initiation sites, polyA-sites etc.
The vector is selected depending on the intended expression system and for this single copy plasmids, multi-copy plasmids as well as vehicles which facilitate an integration of the nucleic acid into the host genome come into consideration. A large number of suitable vectors are known from the state of the art and will not be described in detail here. They optionally contain standard elements used for vectors such as resistances, selection markers or/and elements which for example enable an amplification of the nucleic acid or the induction of expression.
A further aspect of the present invention concerns a cell which is transformed or transfected with such a vector which carries as an insert at least one copy of a nucleic acid sequence coding for a streptavidin mutein according to the invention. The selection of the cell is not particularly critical and in general it is possible to use any cells that are suitable for such purposes. Prokaryotic as well as eukaryotic cells and yeasts come into consideration. For practical reasons prokaryotic cells are generally preferred and in particular E. coli for the expression of an unglycosylated protein as in the present case.
Yet a further aspect of the present invention concerns a process for the production of a streptavidin mutein according to the invention which is characterized by the following steps:
(a) transforming a suitable host cell with a vector which contains a nucleic acid coding for the streptavidin mutein,
(b) culturing the host cell under conditions in which an expression of the streptavidin mutein takes place,
(c) isolating the polypeptide.
With respect to the production process it must be noted that the streptavidin muteins according to the invention may have a toxic effect due to their ability to bind to endogeneous cell biotin. Hence when culturing the host cell the conditions should be selected such that the expression product that forms is either transported from the inside of the host cell used for example into the periplasma or into the culture medium by means of a suitable signal sequence or it aggregates inside the cell in the form of insoluble inclusion bodies. In the former case the streptavidin mutein according to the invention can be isolated from the periplasmic cell fraction or the cell supernatant whereas in the latter case step (c) of the process according to the invention comprises the lysis of host cells, the isolation of the streptavidin mutein in the form of inclusion bodies and the renaturation of the streptavidin mutein. In this case E. coli is preferred as the host cell.
The practical applications for the streptavidin muteins or the streptavidin mutein/peptide ligand system according to the invention are essentially the same as those for conventional streptavidin/biotin or streptavidin/peptide ligand systems. There are advantages especially in situations in which a higher binding strength is desired than that between native streptavidin and peptide ligand or in situations in which it is not possible to biotinylate a substrate of interest or is less easy than the corresponding linkage to a peptide ligand.
The advantages over the conventional streptavidin/biotin system apply in particular to affinity chromatography and in purification, isolation or determination methods for recombinant proteins. Accordingly the invention also concerns the use of a streptavidin mutein according to the invention in a method for the isolation, purification or detection of a protein that is fused with a peptide sequence of the formula Trp-Xaa-His-Pro-Gln-Phe-Xaa-Xaa (SEQ ID NO: 16) in which X represents an arbitrary amino acid and Y and Z either both denote Gly or Y denotes Glu and Z denotes Arg or Lys wherein a liquid containing the protein to be isolated or purified is contacted with the optionally immobilized streptavidin mutein under suitable conditions in order to bind the peptide sequence to the streptavidin mutein, the resulting complex is separated from the liquid and the protein is released from the complex or detected. The peptide sequence is particularly preferably selected in the form of strep-tag or strep-tag II. The peptide sequence is preferably fused to the N- or/and C-terminus of the protein. The streptavidin mutein can be bound to a solid phase or can be capable of binding to it.
An advantage of utilizing the streptavidin mutein/peptide ligand system according to the invention in an isolation or purification method is that very mild conditions can be used to elute the fusion protein carrying the peptide ligand. Hence it is possible to incubate a solid phase coupled to the streptavidin mutein, such as for example an affinity chromatography column to which the fusion protein has been adsorbed, with an adequate concentration of a ligand selected from biotin and derivatives thereof in order to release the fusion protein from the complex. In this connection the use of desthiobiotin has proven to be particularly advantageous.
The streptavidin muteins according to the invention can be used in detection methods in an essentially similar manner to the corresponding methods that are known for conventional streptavidin. A further application is the qualitative or quantitative determination of a protein which is fused with a peptide sequence of the formula Trp-Xaa-His-Pro-Gln-Phe-Xaa-Xaa (SEQ ID NO: 16) in which X represents an arbitrary amino acid and Y and Z either both denote Gly or Y denotes Glu and Z denotes Arg or Lys, wherein the protein to be determined is contacted under suitable conditions with a labelled streptavidin mutein in order to bind the peptide sequence to the streptavidin mutein and the label is determined. Such a determination method can for example be carried out qualitatively to detect proteins in Western blots or quantitatively as an ELISA. Suitable labels are all known radioactive and non-radio-active labelling groups e.g. luminescent groups, enzymes, metals, metal complexes etc. The streptavidin can be directly labelled e.g. by covalent coupling. However, indirect labels such as labelled anti-streptavidin antibodies or biotinylated enzymes etc. can also be used.
A further subject matter of the invention is the use of the streptavidin muteins according to the invention to immobilize a protein which is fused with a peptide sequence Trp-Xaa-His-Pro-Gln-Phe-Xaa-Xaa (SEQ ID NO: 16) in which X represents an arbitrary amino acid and Y and Z either both denote Gly or Y denotes Glu and Z denotes Arg or Lys. This immobilization is preferably carried out on solid phases coated with streptavidin muteins such as microtitre plates, microbeads made of organic or paramagnetic materials or sensor chips.
In addition it is of course also possible to use the streptavidin muteins according to the invention in a conventional streptavidin/biotin (derivative) system. In other words this means the use of the streptavidin muteins according to the invention to determine or isolate substances which carry a group capable of binding to streptavidin. If only a part of the wt-streptavidin is replaced by the streptavidin muteins according to the invention, particular effects can be achieved in this connection via the formation of mixed tetramers.
Yet a further aspect of the invention also concerns a reagent kit which contains a streptavidin mutein according to the invention and optionally standard buffer and auxiliary substances and additives. Such a reagent kit is in particular intended to be used in one of the isolation, purification or determination methods described above. However, the kit is also suitable for other methods in which the conventional streptavidin/biotin system is used e.g. for nucleic acid hybridization assays or immunoassays. The reagent kit can contain the streptavidin mutein according to the invention in a solid phase-bound or/and labelled form.
The invention is further elucidated by the following examples and the attached figures in which:
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 shows a schematic drawing of the vector pASK75-SAp;
FIG. 2 is a graph which shows the binding affinity of recombinant wt-streptavidin compared to streptavidin muteins according to the invention in an ELISA;
FIG. 3 shows the binding affinity of recombinant wt-streptavidin compared to a streptavidin mutein according to the invention in a fluorescence titration and
FIG. 4 shows the purification of a strep-tag fusion protein using a streptavidin mutein by affinity chromatography.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 shows the expression vector pASK75-SAp which contains a sequence coding for a minimal streptavidin (Ala 13 to Ser 139 ), a sequence coding for the OmpA signal peptide as well as the tetracyclin promoter/operator (tet P/O ) for transcription regulation.
Other labelled regions of the vector are the intergenic region of the filamentous phage f1 (f1-IG), the origin of replication (ori), the β-lactamase gene (bla) for ampicillin resistance, the tetracyclin repressor gene (tetR) and the lipoprotein transcription terminator (t lpp ).
The hybrid structural gene containing the coding sequences for the signal peptide and minimal streptavidin begins at the XbaI site and extends downstream to the HindIII site. The junction between the signal sequence and streptavidin is at the StuI/PvuII site. The SacII site which was used to insert the mutated streptavidin gene sequences is also shown.
FIG. 2 shows the improved affinity of the streptavidin muteins according to the invention for the peptide ligand strep-tag II in an ELISA. For this rows of an ELISA plate were each coated with equivalent concentrations of a recombinant wt-streptavidin (rhombus), the mutein "1" (circle) or "2" (square) or only saturated with BSA (cross). After saturating and washing the wells were incubated with a purified fusion protein consisting of bacterial alkaline phosphatase (PhoA) and strep-tag II at the concentrations shown in the graph. After washing to remove unbound protein, the activity of the bound PhoA-strep-tagII fusion protein was measured in the presence of p-nitrophenyl phosphate. The data were fitted by non-linear regression by the least squared error method. The following K d values were obtained: 0.21 μM for mutein "1"; 0.30 μM for mutein "2"; 18 μM for recombinant wt-streptavidin.
FIG. 3 is a graph which shows the binding affinity of recombinant wt-streptavidin compared to streptavidin muteins according to the invention in a fluorescence titration.
A solution of wt-streptavidin (rhombus), the mutein "1" (circle) or "2" (square) was titrated with a solution of the synthesized strep-tag II peptide which was derivatized N-terminally with anthranilic acid and the fluorescence of the tryptophan and tyrosine residues was measured (excitation at 280 nm; emission at 340 nm). The experimental conditions are described in example 6. A K D value for the peptide complex of 13.0±1.3 μM for wt-streptavidin was determined by non-linear regression of the data points according to the theory of simple complex formation whereas the mutants "1" and "2" had K D values of 1.37±0.08 μM and 1.02±0.04 μM respectively.
FIG. 4 shows the purification of the fusion protein composed of bacterial alkaline phosphatase and strep-tag II by affinity chromatography using the immobilized streptavidin mutein "1" according to the invention.
FIG. 4 shows the elution profile (based on the absorbance of the eluate at 280 nm) when purifying the fusion protein composed of bacterial alkaline phosphatase and strep-tag II by affinity chromatography from the bacterial periplasmic cell extract using the immobilized streptavidin mutein "1". The experimental conditions are described in example 4. After removing the host proteins by washing with chromatography buffer, it was eluted successively with solutions of diamino-biotin (dab), desthiobiotin (dtb) and biotin. The bound fusion protein was almost quantitatively eluted in the presence of desthiobiotin. Subsequent analysis by SDS polyacrylamide gel electrophoresis showed an almost complete purity of the protein isolated in this manner.
The invention is further elucidated by the following sequence protocol:
SEQ ID NO. 1: shows the amino acid sequence of the peptide ligand strep-tag,
SEQ ID NO. 2: shows the amino acid sequence of the peptide ligand strep-tag II,
SEQ ID NO. 3/4: show the nucleotide and amino acid sequence of wt-streptavidin in the region of amino acids 44-47,
SEQ ID NO. 5/6: show the nucleotide and amino acid sequence of the streptavidin mutein 1 in the region of amino acids 44-47,
SEQ ID NO. 7/8: show the nucleotide and amino acid sequence of the streptavidin mutein 2 in the region of amino acids 44-47,
SEQ ID NO. 9: shows the nucleotide sequence of the oligonucleotide primer P1,
SEQ ID NO. 10: shows the nucleotide sequence of the oligonucleotide primer P2,
SEQ ID NO. 11: shows the nucleotide sequence of the oligonucleotide primer P3,
SEQ ID NO. 12: shows the nucleotide sequence of the oligonucleotide primer P4,
SEQ ID NO. 13: shows the nucleotide sequence of the oligonucleotide primer P5,
SEQ ID NO. 14: shows the nucleotide sequence of the oligonucleotide primer P6 and
SEQ ID NO. 15: shows the nucleotide sequence of the oligonucleotide primer P7.
SEQ ID NO. 16: shows a general formula for muteins described herein.
SEQ ID NO: 17 shows the wild type sequence of streptavidin.
EXAMPLES
General methods
DNA manipulations were carried out by conventional genetic engineering methods (see e.g. Sambrook et al., Molecular Cloning. A Laboratory Manual (1989), Cold Spring Harbor Press). In general the E. coli K12 strain JM83 (Yanisch-Peron et al., (1985), Gene 33, 103-119) was used for cloning and expression with the exception of the expression under the control of the T7 promoter which was carried out according to Schmidt and Skerra (1994), supra. Sequencings were carried out by plasmid sequencing according to the standard dideoxy technique using the T7 sequencing kit from Pharmacia, Freiburg. The primers and oligonucleotides were synthesized using an Applied Biosystems DNA synthesizer.
Example 1
Preparation of an expression bank for streptavidin muteins
In order to construct the vector pASK75-SAp which carries the gene sequence coding for a minimal streptavidin fused to the coding sequence of the OmpA signal peptide (cf. FIG. 1), the sequence coding for minimal streptavidin was amplified by PCR from the expression vector pSA1 (Schmidt and Skerra, (1994), supra) using the primers P1 and P2:
P1: 5'-GAG ATA CAG CTG CAG AAG CAG GTA TCA CCG GCA C (SEQ ID NO. 9) and
P2: 5'-CGG ATC AAG CTT ATT AGG AGG CGG CGG ACG GCT TCA C (SEQ ID NO. 10)
and Taq DNA polymerase, the reaction product was purified by gel electrophoresis, cleaved with PvuII and HindIII and ligated into the vector fragment of pASK75 cleaved with StuI and HindIII. The complete nucleotide sequence of pASK75 is stated in DE-A-44 17 598.1. The vector generated in this manner pASK75-SAp contains a DNA sequence which codes for the OmpA signal peptide fused to minimal streptavidin beginning at Ala 13 .
A plasmid bank with DNA sequences which code for streptavidin derivatives mutagenized in the region of amino acid positions 44 to 47 (with reference to wt-streptavidin) was prepared by PCR amplification of pASK75-SAp using the following primers P3 and P4:
P3: 5'-TCG TGA CCG CGG GTG CAG ACG GAG CTC TGA CCG GTA CCT ACN N(C/G)N N(G/T)N N(C/G)N N(G/T)G GCA ACG CCG AGA GCC GCT AC (SEQ ID NO. 11) and
P4: 5'-CGG ATC AAG CTT ATT AGG AGG CGG CGG ACG GCT TCA C (SEQ ID NO. 12).
DNA sequences were generated in this manner which contained 32-fold degenerated codons for each of all the 20 amino acids or a stop codon at each of the four positions 44 to 47. In addition a KpnI restriction site was generated at the site in the region of the codons for the amino acids 41/42. The resulting PCR products were purified by gel electrophoresis, cleaved with SacII and HindIII and ligated into the correspondingly cleaved vector fragment of pASK75-SAp.
E. coli JM83 cells were transformed with the vector mixture using the calcium chloride method (Sambrook et al., 1989).
Example 2
Identification of streptavidin muteins with an increased binding affinity for peptide ligands
In order to identify streptavidin muteins with an increased binding affinity for peptide ligands, a fusion protein was prepared comprising the alkaline phosphatase of E. coli (PhoA) and the strep-tag II peptide (WSHPQFEK) which was attached to its C-terminus. For this the complete phoA gene including its own signal sequence and translation initiation region was amplified by PCR according to a method published by Skerra (Nucleic Acids Res. 20 (1992), 3551 to 3554) from chromosomal E. coli K12 W3110 DNA (Bachmann, Bacteriol. Rev. 36 (1972), 525-557) using the phosphorothioate primers P5 and P6 and pfu DNA polymerase:
P5: 5'-TAA TGT TCT AGA ACA TGG AGA AAA TAA AGT GAA ACA AAG GAC (SEQ ID NO. 13) and
P6: 5'-GCT AGG CGG TTT CAG CCC CAG AGC GGC TTT C (SEQ ID NO: 14).
The PCR product obtained in this manner was purified and cleaved with the restriction enzyme XbaI. This DNA fragment was then inserted in several steps into the plasmid pASK75-strepII (constructed from pASK75 by site-specific mutagenesis using the oligodeoxynucleotide P7 5'-CAC AGG TCA AGC TTA TTA TTT TTC GAA CTG CGG GTG AGA CCA AGC GCT GCC TGC (SEQ ID NO. 15) while replacing the region between XbaI and Eco47III to obtain the expression plasmid pASK75-PhoA strep II.
The protein production took place in 2 l LB medium containing 100 μg/ml ampicillin in which the gene expression was induced at A 550 =0.5 by addition of 0.2 μg/ml anhydrotetracyclin. The induction was carried out overnight at a temperature of 37° C. The PhoA/strep-tag II fusion enzyme was then purified from the periplasmic cell fraction by streptavidin affinity chromatography using diaminobiotin as the eluting agent according to the procedure of Schmidt and Skerra (1994), supra. Due to the presence of Zn(II) ions and Mg(II) ions in the active centre of the enzyme the chromatography buffer contained no EDTA.
The plasmid bank obtained in example 1 was plated out on a hydrophilic GVWP membrane (Millipore, Eschborn) which had been placed on an Agar plate containing LB medium which contained 100 μg/ml ampicillin. The membrane was incubated for 7 to 8 hours at 37° C. until colonies became visible.
Then a second membrane was prepared, an Immobilon-P membrane (Millipore, Eschborn) which was coated for ca. 6 hours with anti-streptavidin immunoglobulin (Sigma, Deisenhofen) at a concentration of 720 μg/ml in PBS (4 mM KH 2 PO 4 , 16 mM Na 2 HPO 4 , 115 mM NaCl) and afterwards was blocked for ca. 2 hours in 3% w/v bovine serum albumin (BSA), 0.5% v/v Tween in PBS.
This second membrane was placed on a M9 minimal agar plate which contained 100 μg/ml ampicillin and 0.2 μg/ml anhydrotetracyclin. Subsequently the GVWP membrane with the colonies on the upper side was placed on the second membrane and the relative positions of the two membranes was marked. After incubation overnight at room temperature the upper membrane with the colonies was removed and stored on a fresh LB ampicillin agar plate at 4° C. The second membrane was also removed from the agar plate and washed three times for 1 minute while shaking in PBS/Tween (0.1% v/v Tween in PBS). Subsequently the membrane was admixed with 10 ml fresh PBS/Tween solution containing the purified PhoA/strep-tagII fusion protein (ca. 1-2 μg/ml). After incubating for one hour at room temperature it was washed again twice in PBS/Tween and twice in PBS buffer. The signal generation took place for 1 to 2 hours in the presence of 10 ml AP buffer (100 mM Tris, pH 8.8, 100 mM NaCl, 5 MM MgCl 2 ) with addition of 30 μl bromo-chloro-indolylphosphate (BCIP) (50 mg/ml in dimethylformamide) and 5 μl nitroblue tetrazolium (NBT) (75 mg/ml in 70% v/v dimethylformamide). The colour spots which formed in this process were assigned to corresponding colonies on the first membrane. After isolation and culture of these clones, two streptavidin muteins "1" and "2" were identified. The nucleotide and amino acid sequences in the mutagenized region for wt-streptavidin and for the muteins were as follows:
______________________________________wt-streptavidin GAG TCG GCC GTC (SEQ ID NO. 3) Glu.sup.44 Ser.sup.45 Ala.sup.46 Val.sup.47 (SEQ ID NO. 4) mutein "1" GTC ACG GCG CGT (SEQ ID NO. 5) Val Thr Ala Arg (SEQ ID NO. 6) mutein "2" ATC GGT GCG AGG (SEQ ID NO. 7) Ile Gly Ala Arg (SEQ ID NO. 8)______________________________________
Example 3
Production of streptavidin muteins on a preparative scale
The known expression system for recombinant minimal streptavidin (Schmidt and Skerra (1994), supra) was used to produce streptavidin muteins on a preparative scale. For this the major part of the coding region was removed from the vector pSA1 which contains the coding region of wt-streptavidin and the T7 promoter by using the singular SacII and HindIII restriction sites and replaced by the corresponding regions from the mutated pASK75-SAp plasmids. wt-streptavidin and the streptavidin muteins were subsequently expressed in the form of cytoplasmic inclusion bodies, solubilized, renatured and purified by fractional ammonium sulphate precipitation as described by Schmidt and Skerra (1994) supra. The purity of the proteins was checked by SDS-PAGE using the discontinuous buffer system of Fling and Gregerson (Anal. Biochem. 155 (1986), 83-88). Characterization of the purified proteins that were dialysed against water by electrospray ionisation mass spectrometry yielded masses of 13334 for the recombinant wt-streptavidin (theoretical 13331.5), 13371 for mutein "1" (theoretical 13372.6) and 13344 for mutein "2" (theoretical 13342.5).
Example 4
Affinity chromatography
The streptavidin muteins prepared in example 3 and wt-streptavidin were coupled to NHS-activated Sepharose 4B (Pharmacia Freiburg) at a loading of 5 mg protein per ml swollen gel (Schmidt and Skerra, 1994, supra). After blocking the remaining active groups overnight with 100 mM Tris/HCl, pH 8.0, 2 ml of the gel was placed in a column with a diameter of 7 mm. In order to examine the behaviour of the streptavidin muteins immobilized in this manner in the affinity purification of strep-tag or strep-tagII-carrying fusion proteins, the recombinant protease inhibitor cystatin (Schmidt and Skerra 1994, supra) which was either fused to strep-tag or strep-tagII as well as the PhoA/strep-tagII fusion protein mentioned above were used. The fusion proteins were produced in an expression system by secretion into the periplasmic space and the periplasmic cell fraction was prepared as described in Schmidt & Skerra (1994), supra.
The chromatography was carried out in the presence of 100 mM Tris/HCl, pH 8.0 containing 1 mM EDTA (except in the case of PhoA) at a flow rate of ca. 20 ml/h and the eluate absorbance was measured at 280 nm. After applying a sample of 10 ml corresponding to the periplasmic cell fraction of 1 l E. coli culture medium, the column was washed until the absorbance at 280 nm had reached the base line. Afterwards bound protein was eluted step-wise by applying 10 ml each of diaminobiotin, desthio-biotin and biotin (all from Sigma, Deisenhofen) at a concentration of 2.5 mM in chromatography buffer and in the stated order.
It turned out that, in contrast to wt-streptavidin, the use of diaminobiotin did not lead to an elution in the case of the streptavidin muteins. When the biotin derivative desthiobiotin, which binds with a higher affinity to streptavidin, was used an elution with a sharp maximum was also achieved in the case of the muteins. This was quantitative since in the subsequent elution with biotin essentially no amounts of fusion protein could be detected in the eluate (cf. FIG. 4).
Example 5
ELISA
An ELISA was carried out to determine the binding affinity of the streptavidin muteins for the peptide ligand strep-tagII.
The wells of a 96-well microtitre plate (Becton Dickinson Co., Oxnard, Calif.) were coated overnight with 100 μl of a solution of recombinant wt-streptavidin or the muteins "1" or "2" at a concentration in each case of 100 μg/ml in 50 mM NaHCO 3 , pH 9.6. The wells were then blocked for 2.5 hours with 3% w/v BSA, 0.5% v/v Tween in PBS. After washing three times with PBS/Tween, 50 μl of the same buffer was added to each well. 20 μl from a solution of 20 μl of 4.85 μM purified and dialysed PhoA/strep-tag II fusion protein plus 30 μl PBS/Tween was added to the first well of each row and mixed. A dilution series was set up in the other wells of a row by pipetting 50 μl (from a total of 100 μl) out of the first well and mixing it with the contents (50 μl) of the next well in the same row etc. In this manner concentrations of the fusion protein between 970 nM in the first well of each row and 0.19 nM in the tenth well were obtained.
After incubating for one hour the solutions were removed and the wells were each washed twice with PBS/Tween and with PBS. Subsequently 100 μl of a solution of 0.5 mg/ml p-nitrophenyl phosphate in 1 mM ZnSO 4 , 5 mM MgCl 2 , 1 mM Tris/HCl, pH 8.0 was pipetted into each well. The activity of the bound fusion protein was measured using a SpectraMAX 250 photometer (Molecular Devices, Sunnyvale, Calif.) as an absorbance change at 410 nm per time.
The data were evaluated assuming a single binding equilibrium between streptavidin (mutein) monomers (P) and the PhoA/strep-tag II fusion protein (L) which yielded a dissociation constant K D =[P] [L]/[P.sup.. L]. Under the condition that [P] TOT =[P]+[P.sup.. L] and that [L] is very much larger than [P.sup.. L] so that [L] TOT is approximately the same as [L] [P.sup.. L]=[L] TOT [P] TOT /(K D +[L] TOT applies for the amount of bound fusion protein. FIG. 2 shows a graph of the experimental results obtained.
It can be seen from the binding curves that the two streptavidin muteins have a very similar affinity for the strep-tap II fusion protein which is more than an order of magnitude higher than the affinity of wt-streptavidin.
Example 6
Fluorescence titration
In order to determine the dissociation constant of the 1:1 complex of the streptavidin muteins (considered as a monomer) and the peptide ligands, a fluorescence titration was carried out with the strep-tag II synthesized by peptide chemistry.
The peptide with the sequence Abz-Trp-Ser-His-Pro-Gln-Phe-Glu-Lys-COOH (SEQ ID NO: 6, with N-terminal Abz added thereto) (Abz represents o-aminobenzoic acid i.e. anthranilic acid) was synthesized stepwise on a solid phase from Fmoc-protected amino acids according to methods known to a person skilled in the art in the order C-terminus to N-terminus wherein Abz was coupled in the last step as a Boc-protected derivative. The peptide was subsequently cleaved from the carrier and freed of the protecting groups. After purification by HPLC the mole mass was confirmed by means of field desorption mass spectrometry.
The fluorescence titration was carried out with an LS50 fluorescence spectrophotometer from the Perkin Elmer Company (Langen) in a 1.sup.. 1 cm 2 quartz cuvette which was thermostated at 25° C. The wavelengths for excitation and emission were 280 nm and 340 nm respectively with a respective slit width of 5 nm. 2 ml of the solution of wt-streptavidin or the muteins "1" and "2", which were prepared as described in example 3 and had been dialysed against 1 mM EDTA, 100 mM Tris/HCl pH 8.0, were placed in the cuvette at a concentration of 1 μM (determined by absorbance photometry for the respective monomer using an extinction coefficient of .di-elect cons. 280 =40455 M -1 cm -1 ). Then volumes of 1 μl or 4 μl of a 0.5 mM solution of the peptide in the same buffer were repeatedly added by pipette (a total of 40 μl) and after mixing with a stirring bar the fluorescence intensity was read. The data were evaluated as described in FIG. 3.
__________________________________________________________________________# SEQUENCE LISTING - - - - <160> NUMBER OF SEQ ID NOS: 17 - - <210> SEQ ID NO 1 <211> LENGTH: 9 <212> TYPE: PRT <213> ORGANISM: Artificial sequence <220> FEATURE: <221> NAME/KEY: BINDING <223> OTHER INFORMATION: Binding ligand for strept - #avidin - - <400> SEQUENCE: 1 - - Ala Trp Arg His Pro Gln Phe Gly Gly 1 5 - - - - <210> SEQ ID NO 2 <211> LENGTH: 8 <212> TYPE: PRT <213> ORGANISM: Artificial sequence <220> FEATURE: <221> NAME/KEY: BINDING <223> OTHER INFORMATION: Binding ligand for strept - #avidin - - <400> SEQUENCE: 2 - - Trp Ser His Pro Gln Phe Glu Lys 1 5 - - - - <210> SEQ ID NO 3 <211> LENGTH: 12 <212> TYPE: DNA <213> ORGANISM: Artificial sequence <220> FEATURE: <221> NAME/KEY: CDS <223> OTHER INFORMATION: Synthesized - - <400> SEQUENCE: 3 - - gagtcg gccg tc - # - # - # 12 - - - - <210> SEQ ID NO 4 <211> LENGTH: 4 <212> TYPE: PRT <213> ORGANISM: Streptomyces avidinii <220> FEATURE: <223> OTHER INFORMATION: Amino acids 44-47 of w - #ild type streptavidin - - <400> SEQUENCE: 4 - - Glu Ser Ala Val - - - - <210> SEQ ID NO 5 <211> LENGTH: 12 <212> TYPE: DNA <213> ORGANISM: Artificial sequence <220> FEATURE: <221> NAME/KEY: CDS <223> OTHER INFORMATION: Synthesized - - <400> SEQUENCE: 5 - - gtcacggcgc gt - # - # - # 12 - - - - <210> SEQ ID NO 6 <211> LENGTH: 4 <212> TYPE: PRT <213> ORGANISM: Artificial sequence <220> FEATURE: <221> NAME/KEY: MUTAGEN <223> OTHER INFORMATION: Mutagen of amino acids - #44-47 of wild type streptavidin - - <400> SEQUENCE: 6 - - Val Thr Ala Arg - - - - <210> SEQ ID NO 7 <211> LENGTH: 12 <212> TYPE: DNA <213> ORGANISM: Artificial sequence <220> FEATURE: <221> NAME/KEY: CDS <223> OTHER INFORMATION: Synthesized - - <400> SEQUENCE: 7 - - atcggtgcga gg - # - # - # 12 - - - - <210> SEQ ID NO 8 <211> LENGTH: 4 <212> TYPE: PRT <213> ORGANISM: Artificial sequence <220> FEATURE: <221> NAME/KEY: MUTAGEN <223> OTHER INFORMATION: Mutagen of amino acids - #44-47 of wild type streptavidin - - <400> SEQUENCE: 8 - - Ile Gly Ala Arg - - - - <210> SEQ ID NO 9 <211> LENGTH: 34 <212> TYPE: DNA <213> ORGANISM: Artificial sequence <220> FEATURE: <221> NAME/KEY: primer.sub.-- .sub.-- bind <223> OTHER INFORMATION: primer for sequence encod - #ing streptavidin - - <400> SEQUENCE: 9 - - gagatacagc tgcagaagca ggtatcaccg gcac - # -# 34 - - - - <210> SEQ ID NO 10 <211> LENGTH: 37 <212> TYPE: DNA <213> ORGANISM: Artificial sequence <220> FEATURE: <221> NAME/KEY: primer.sub.-- .sub.-- bind <223> OTHER INFORMATION: primer for sequence encod - #ing streptavidin - - <400> SEQUENCE: 10 - - cggatcaagc ttattaggag cgggcggacg gcttcag - #- # 37 - - - - <210> SEQ ID NO 11 <211> LENGTH: 74 <212> TYPE: DNA <213> ORGANISM: Artificial sequence <220> FEATURE: <221> NAME/KEY: primer.sub.-- .sub.-- bind <223> OTHER INFORMATION: degenerate primer sequence - #for use inencoding mutations in <223> OTHER INFORMATION: amino acids 44-47 of s - #treptavidin. "n" isused at positions <223> OTHER INFORMATION: 42,43,45,46,48,49,51 and 52. - # In each case,"n" can be a, c, <223> OTHER INFORMATION: t, or g. - - <400> SEQUENCE: 11 - - tcgtgaccgc gggtgcagac ggagctctga ccggtaccta cnnsnnknns nn -#kggcaacg 60 - - ccgagagccg ctag - # - # - # 74 - - - - <210> SEQ ID NO 12 <211> LENGTH: 37 <212> TYPE: DNA <213> ORGANISM: Artificial sequence <220> FEATURE: <221> NAME/KEY: primer.sub.-- .sub.-- bind <223> OTHER INFORMATION: Primer sequence used in - #connection with SEQID NO: 12 to <223> OTHER INFORMATION: generate mutations of str - #eptavidin - - <400> SEQUENCE: 12 - - cggatcaagc ttattaggag cgggcggagc gcttcac - #- # 37 - - - - <210> SEQ ID NO 13 <211> LENGTH: 42 <212> TYPE: DNA <213> ORGANISM: Artificial sequence <220> FEATURE: <221> NAME/KEY: primer.sub.-- .sub.-- bind <223> OTHER INFORMATION: Primer for encoding fusio - #n protein of E.coli alkaline <223> OTHER INFORMATION: phosphatase and SEQ ID - #NO: 2 - - <400> SEQUENCE: 13 - - taatgttcta gaacatggag aaaataaagt gaaacaaagg ac - # - # 42 - - - - <210> SEQ ID NO 14 <211> LENGTH: 31 <212> TYPE: DNA <213> ORGANISM: Artificial sequence <220> FEATURE: <221> NAME/KEY: primer.sub.-- .sub.-- bind <223> OTHER INFORMATION: Primer used with SEQ I - #D NO: 13 - - <400> SEQUENCE: 14 - - gctaggcggt ttragcccca gagcgg cttt c - # - # 31 - - - - <210> SEQ ID NO 15 <211> LENGTH: 54 <212> TYPE: DNA <213> ORGANISM: Artificial sequence <220> FEATURE: <221> NAME/KEY: primer.sub.-- .sub.-- bind <223> OTHER INFORMATION: Used for site directed - #mutagenesis ofsequences generated <223> OTHER INFORMATION: by SEQ ID NOS: 13 & - # 14. - - <400> SEQUENCE: 15 - - cacaggtcaa gcttattatt tttcgaactg cgggtgagac caagcgctgc ct - #gc 54 - - - - <210> SEQ ID NO 16 <211> LENGTH: 8 <212> TYPE: PRT <213> ORGANISM: Artificial sequence <220> FEATURE: <221> NAME/KEY: VARIANTS <222> LOCATION: Positions 2, 7 & 8 <223> OTHER INFORMATION: First Xaa (position 2) - #is any amino acid. Second Xaa <223> OTHER INFORMATION: (position 7), is Gly o - #r Glu. Third Xaa (position 8) is <223> OTHER INFORMATION: Gly, Arg or Lys. Secon - #d Xaa must be Glywhen third Xaa <223> OTHER INFORMATION: is Gly, and must be - #Glu when third Xaa isArg or Lys - - <400> SEQUENCE: 16 - - Trp Xaa His Pro Gln Phe Xaa Xaa 1 5 - - - - <210> SEQ ID NO 17 <211> LENGTH: 159 <212> TYPE: PRT <213> ORGANISM: Streptomyces avidinii - - <400> SEQUENCE: 17 - - Asp Pro Ser Lys Asp Ser Lys Ala Gln Val Se - #r Ala Ala Glu AlaGly 1 5 - # 10 - # 15 - - Ile Thr Gly Thr Trp Tyr Asn Gln Leu Gly Se - #r Thr Phe Ile Val Thr 20 - # 25 - # 30 - - Ala Gly Ala Asp Gly Ala Leu Thr Gly Thr Ty - #r Glu Ser Ala Val Gly 35 - # 40 - # 45 - - Asn Ala Glu Ser Arg Tyr Val Leu Thr Gly Ar - #g Tyr Asp Ser Ala Pro 50 - # 55 - # 60 - - Ala Thr Asp Gly Ser Gly Thr Ala Leu Gly Tr - #p Thr Val Ala Trp Lys 65 - #70 - #75 - #80 - - Asn Asn Tyr Arg Asn Ala His Ser Ala Thr Th - #r Trp Ser Gly Gln Tyr 85 - # 90 - # 95 - - Val Gly Gly Ala Glu Ala Arg Ile Asn Thr Gl - #n Trp Leu Leu Thr Ser 100 - # 105 - # 110 - - Gly Thr Thr Glu Ala Asn Ala Trp Lys Ser Th - #r Leu Val Gly His Asp 115 - # 120 - # 125 - - Thr Phe Thr Lys Val Lys Pro Ser Ala Ala Se - #r Ile Asp Ala Ala Lys130 - # 135 - # 140 - - Lys Ala Gly Val Asn Asn Gly Asn Pro Leu As - #p Ala Val Gln Gln 145 1 - #50 1 - #55__________________________________________________________________________ | The invention concerns a polypeptide selected from muteins of streptavidin which is characterized in that it (a) contains at least one mutation in the region of the amino acid positions 44 to 53 with reference to wild type-(wt)-streptavidin and (b) has a higher binding affinity than wt-streptavidin for peptide ligands comprising the amino acid sequence Trp-X-His-Pro-Gln-Phe-Y-Z in which X represents an arbitrary amino acid and Y and Z either both denote Gly or Y denotes Glu and Z denotes Arg or Lys. In addition nucleic acids coding for the polypeptide, a vector containing this nucleic acid, a cell transfected with the vector as well as the use of a polypeptide in a method for the isolation, purification or determination of proteins are disclosed. Yet a further subject matter is a reagent kit containing the polypeptide. | big_patent |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is broadly concerned with methods of forming substituted guanidines utilizing nickel catalysts. More particularly, the methods comprise guanylating amines or pyrrolidines with guanylating agents such as thioureas or isothioureas in the presence of a nickel catalyst. Preferably, the nickel catalyst comprises nickel in the zero oxidation state. Suitable Ni(0) catalysts are preferably derived from nickel-boride alloys, nickel-phosphide alloys, aluminum-nickel alloys, nickel on kieselguhr, nickel on silica/alumina, and other nickel catalysts.
2. Description of the Prior Art
The guanidine functional group is an important structural component in many biologically active compounds. Due to their strongly basic character, guanidines are fully protonated under physiological conditions. The positive charge thus imposed on the molecule forms the basis for specific interactions between ligand and receptor or between enzyme and substrate, mediated by hydrogen bonds and/or electrostatic interactions. As a result, the guanidino group has been incorporated into many clinically useful drugs. For example, the guanidino group is used in H 2 -receptor antagonists such as cimetidine and tiotidine which are anti-ulcer agents. The guanidine functional group is also found in cardiovascular drugs (e.g., clonidine, guanethidine), anti-diabetic drugs (e.g., phenformin, metformin), anti-malarial drugs (e.g., chloroguanidine), antibacterial agents (e.g., streptomycin), as well as other drugs.
Due to their importance in drug development, synthetic procedures for the preparation of guanidines under mild reaction conditions and in high yields while using minimal amounts of reagents are of significant interest to the pharmaceutical industry. Mild reaction conditions are necessary during the synthesis process because harsh conditions will lower the yield of the reaction product due to decomposition or unwanted side reactions of the valuable drug precursor. Reducing the number and quantity of reagents minimizes the quantity of reagent by-products generated which must be removed from the drug product, thus resulting in decreased drug production costs. Finally, of particular importance are chemical synthesis methods that minimize or eliminate the use of toxic reagents or catalysts, particularly in large scale industrial drug production.
Typically, synthesis of guanidines involves treating amines with guanylating agents. The most commonly used agents include derivatives of pyrazole-1-carboxamidine, aminoiminomethanesulfonic acid, S-methylisothiouronium salts, S-alkylisothioureas, and protected thiourea derivatives.
Substituted and protected thioureas are widely employed in the preparation of substituted guanidines. Coupling reagents (e.g., Ph 3 P/CCl 4 and thiophilic metal salts such as HgO/S, HgCl 2 , CuCl 2 , and CuSO 4 ) have been extensively used in conjunction with thioureas for the guanylation of both aliphatic and aromatic amines. The initial step in these reactions involves the formation of intermediate carbodiimides which will then react with amines to give the corresponding guanidines. However, these reactions generally require an excess amount of reagents and/or longer reactions times in order to provide acceptable yields of the particular substituted guanidine. Furthermore, a distinct disadvantage to the use of mercuric salts in guanylation reactions is that the mercuric salts are toxic compounds. Finally, it is very difficult to separate the guanidines from the unreacted mercuric salts and the mercuric sulfide byproduct.
N-Unsubstituted S-methylisothioureas are useful for guanylating aliphatic primary and secondary amines. However, N-alkyl substituted S-methylisothioureas are inadequate at guanylating aliphatic primary and secondary amines due to the fact that this reaction is reversible and the byproduct methyl mercaptan must continually be removed from the reaction mixture in order to drive the reaction to completion.
There is a need for methods of guanylating amines in high yields which do not require the large quantities of coupling reagents and bases used in prior art methods.
SUMMARY OF THE INVENTION
The instant invention broadly comprises methods of forming substituted guanidines in the presence of a nickel catalyst. In more detail, guanylating agents are reacted with a compound selected from the group consisting of amines utilizing the nickel catalyst.
The nickel catalysts utilized in the inventive methods preferably comprise nickel in the zero oxidation state. Suitable Ni(0) catalysts are preferably derived from nickel-boride alloys, nickel-phosphide alloys, aluminum-nickel alloys, nickel on kieselguhr, and nickel on silica/alumina. Nickel catalysts are particularly advantageous due to their relatively inexpensive cost. Furthermore, the nickel catalysts are essentially completely recoverable after the guanylation reactions so that they may be reused. During the guanylation reactions, the nickel catalyst should be present at a level of less than about 10 molar % nickel, and preferably less than about 5 molar % nickel, based upon the total moles of guanylating agent(s) (e.g., isothioureas and/or thioureas) taken as 100%.
Preferred guanylating agents are thioureas and isothioureas, which have the respective general formulas ##STR1## wherein each of R 1 -R 4 is individually selected from the group consisting of hydrogen, protecting groups (i.e., a group which prevents the atom to which it is attached from reacting with any of the compounds present in the reaction mixture), aliphatic groups (branched and unbranched, preferably C 1 -C 22 ), and cyclic groups (preferably aromatic), and wherein X is selected from the group consisting of aliphatic groups (preferably lower alkyl C 1 -C 4 groups such as methyl groups) and cyclic groups (preferably aromatic or preferably C 3 -C 8 aliphatic cyclic groups).
At least one of R 1 -R 4 should preferably be a protecting group, and more preferably R 1 and R 3 are both protecting groups, with preferred protecting groups being selected from the group consisting of Boc groups (i.e., tert-butoxycarbonyl groups), Cbz groups (i.e., carbobenzyloxy groups), and arylsulfonyl groups. Arylsulfonyl groups include p-toluenesulfonyl groups and 4-methoxy-2,3,6-trimethylbenzylsulfonyl groups. Those skilled in the art will appreciate that the location of the particular protecting group(s) can be selected depending upon the desired final substituted guanidine. Particularly preferred protected thioureas and isothioureas include bis-Boc-protected thioureas and isothioureas. Of course, the protecting groups can be readily removed from the resulting guanidine using conventional methods.
In one embodiment, the methods of the invention comprise reacting a compound having the structure Formula I with an amine or pyrrolidine, wherein R 1 and R 3 of Formula I are Boc groups. In another embodiment, the invention comprises reacting a compound having the structure Formula II with an amine or pyrrolidine, wherein X of Formula II is selected from the group consisting of alkyl groups (and particularly methyl groups) and benzyl groups. Even more preferably, in this latter embodiment R 1 and R 2 of Formula II are phenyl.
In another embodiment, the methods of the invention comprise reacting pyrrolidine with a compound selected from the group consisting of ##STR2##
Particularly preferred thioureas and isothioureas are those selected from the group consisting of ##STR3##
While essentially any amine can be reacted with a guanylating agent in the presence of a nickel catalyst according to the invention, preferred amines are primary and secondary amines. Specific amines which work well with the instant methods include those selected from the group consisting of ##STR4##
The inventive reactions are preferably carried out at a temperature of from about -30-140° C., and more preferably at room temperature or under ambient conditions. It is preferable that the reaction be carried out in a solvent system. Suitable solvent systems comprise a solvent selected from the group consisting of DMF, THF, DMSO, and water mixed with any of the foregoing. Carrying out the reactions with a nickel catalyst and a thiourea as the guanylating agent will result in a percent yield (based upon the theoretical yield) of at least about 10%, preferably at least about 40%, and more preferably at least about 85%, after a reaction time of about 30 minutes. Carrying out the reactions with a nickel catalyst and an isothiourea as the guanylating agent will result in a percent yield (based upon the theoretical yield) of at least about 10%, preferably at least about 40%, and more preferably at least about 85%, after a reaction time of about 2 hours.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The methods of the instant invention can be utilized to synthesize N-substituted and N,N-disubstituted guanidines from bis-protected thioureas in the presence of a nickel catalyst. Suitable protecting groups include Boc groups and Cbz groups. The N protecting groups can be easily cleaved from the resulting guanidines under mild reaction conditions. These bis-protected thioureas can be utilized to guanylate both aromatic and aliphatic primary and secondary amines at room temperature with high yields. A general reaction scheme by which this guanylation takes place is shown in Scheme 1. ##STR5##
Those skilled in the art will appreciate that mono-, di-, tri-, and tetrasubstituted guanidines can be synthesized from N-protected thioureas in the presence of a nickel catalyst such as nickel-boride (nickel boride, nickel-boride, nickel boride alloy, and nickel-boride alloy are used interchangeably herein to refer to alloys comprising nickel and boride). Suitable protecting groups again include Boc and Cbz, as well as an N-arylsulfonyl group. These protected thioureas can be used to guanylate both aromatic and aliphatic amines. One general reaction by which this guanylation occurs is shown in Scheme 2. ##STR6##
N-Arylsulfonyl protected methylisothioureas can also be used to guanylate aliphatic and aromatic amines in the presence of a nickel catalyst. A general outline of this reaction is shown in Scheme 3. ##STR7## 1,3-diphenyl-S-methylisothiourea can be used to guanylate aliphatic and cyclic amines in the presence of a nickel catalyst. A general outline of this reaction is shown in Scheme 4. ##STR8##
While it is possible that the inventive guanylation reactions take place via a carbodiimide intermediate, because the reactions are taking place under neutral conditions it is believed that the mechanism by which the nickel catalyst promotes guanylation reactions is similar to that described by Ni et al., Nickel-Catalyzed Olefination of Cyclic Benzylic Dithioacetals by Grignard Reagents, J. Org. Chem. 56:4035-42 (1991), incorporated by reference herein. That is, it is believed that the nickel(0) species initially coordinates with the divalent sulfur of thiourea and then undergoes oxidative insertion of nickel into the carbon-sulfur double bond to give the three-membered cyclic intermediate Formula III shown in Scheme 5. ##STR9## The highly reactive cyclic intermediate Formula III yields the complex designated by Formula IV as a result of the nucleophilic attack of the amine and breaking of the carbon-nickel bond. Cleavage of the carbon-sulfur bond by elimination of the proton on the adjacent nitrogen forms the Formula V guanidine and a hydrido nickel(II) complex (which thermally decomposes to regenerate the Ni(0) species). A similar mechanism is believed to occur when the guanylating agent is a isothiourea.
EXAMPLES
The following examples set forth preferred methods in accordance with the invention. It is to be understood, however, that these examples are provided by way of illustration and nothing therein should be taken as a limitation upon the overall scope of the invention.
Example 1
Synthesis of Isothioureas and Thioureas
1. N,N'-Bis-tert-butoxycarbonylthiourea
Isothioureas were prepared for use in the exemplary guanylation reactions. N,N'-bis-tert-butoxycarbonylthiourea was prepared according to the protocol reported by Iwanowicz et al., Preparation of N,N'-Bis-tert-Butoxycarbonylthiourea, Synth. Commun., 23:1443-45 (1993). The reaction by which the N,N'-bis-tert-butoxycarbonylthiourea was formed is outlined in Scheme A. ##STR10##
Wherein Boc refers to tert-butoxycarbonyl.
2. N-Arylsulfonyl-S-methylisothiourea
N-Arylsulfonyl-S-methylisothiourea was prepared as described by Kent et al., Two New Reagents for the Guanylation of Primary, Secondary and Aryl Amines, Tetrahedron Lett., 37:8711-14 (1996). This reaction is outlined in Scheme B. ##STR11## 3. Synthesis of N,N'-diphenyl-S-benzylisothioureas and N,N'-diphenyl-S-methylisothioureas
A solution of halide (55 mmol) in acetone (25 ml) was added dropwise to a stirred suspension of thiocarbanilide (11.40 g, 50 mmol) and potassium carbonate (6.90 g, 50 mmol). The reaction mixture was stirred at ice bath temperature for about 30 minutes, followed by stirring at room temperature. The progress of the reaction was monitored by TLC. The reaction mixture was then filtered and the resulting precipitate washed 3 times with 15 ml portions of acetone. The combined filtrates were concentrated on a rotavapor. The residue was diluted with methylene chloride (100 ml) followed by two washings with 25 ml portions of water. The residue was then dried over sodium sulfate. The crude product was purified by passing it through a short silica gel column using a gradient of hexane and diethyl ether as eluents. Scheme C and its accompanying table outline the general reaction which took place as well as the halides used, the isothioureas resulting from the reaction, and the yield of those isothioureas.
__________________________________________________________________________Scheme C #STR12##Entries Halide Isothiourea Reaction time Yield (%)__________________________________________________________________________ 1 Mel 4 h 91 # - 2 #STR14## 6 h 99##__________________________________________________________________________
Example 2
Synthesis of N,N'-bis-tert-butoxycarbonyl Protected Guanidines Guanylation of Amines
Nickel-boride alloy (13 mg, 0.10 mmol, prepared by the reduction of nickel acetate or chloride with sodium borohydride in ethanol or water) was added to a solution of N,N'-bis-tert-butoxycarbonylthiourea (28 mg, 0.10 mmol, prepared in Part 1 of Example 1) and an amine (0.15 mmol) in dimethyl formamide (DMF) contained in a 15 ml screw cap vial. The solution was stirred at room temperature and the progress of the reaction was monitored by thin layer chromatography (TLC). The reaction mixture was then diluted with ethyl acetate (15 ml) and poured into 25 ml of water. The organic layer was separated, and the aqueous layer was extracted with 10 ml of ethyl acetate. The combined extracts were washed twice with 15 ml of water after which they were dried over sodium sulfate, evaporating the solvent. The residue was passed through a short silica gel column using a gradient of hexane and ether as eluents to give the pure guanidine. The general reaction is outlined in Scheme D. The particular amines utilized in the respective preparations as well as the reactions times, resulting guanidines, and yields of those guanidines are set forth in Table 1. ##STR16##
TABLE 1__________________________________________________________________________Guanylation of amines with N,N'-bis-tert-butoxycarbonylthiourea.Entries Amine Guanidine Reaction time Reaction temp Yield (%)__________________________________________________________________________ 1 90 min room temp. 91 - 2 #STR18## 90 min room temp. 94 - 3 #STR20## 2 h room temp. 97 - 4 #STR22## 2 h room temp. 89 - 5 #STR24## 3 h room temp. 91 - 6 #STR26## 90 min room temp. 92__________________________________________________________________________
Guanylation reactions of pyrrolidine with N,N'-bis-tert-butoxycarbonylthiourea were carried out under various reaction conditions utilizing a variety of solvents in order to optimize the suitable solvent conditions to run this reaction ("THF" refers to tetrahydrofuron and "DMSO" refers to dimethyl sulfoxide). The aqueous layer extraction was effected with methylene chloride rather than with ethyl acetate as was the case in Part 1 above. Scheme E outlines the general reaction while Table 2 sets forth the various solvents tested, reaction conditions, and the % yield of guanylated pyrrolidine. DMSO and DMSO-H 2 O (Entries 4 and 5, respectively) were the most effective solvents. ##STR28##
TABLE 2______________________________________Guanylation of pyrrolidine with N,N'-bis-tert-butoxycarbonylthiourea in different reaction conditions. Reaction Reaction Yield Entries Solvent(s) time temp. (%)______________________________________1 DMF 2 h room temp. 89 2 THF 3 h room temp. 100 3 THF-H.sub.2 O (3:1) 1 h room temp. 100 4 DMSO 1 h room temp. 100 5 DMSO-H.sub.2 O (3:1) 45 min room temp. 100______________________________________
Example 3
Synthesis of N-tosyl and N-mtr Protected Guanidines
Nickel-boride alloy (13 mg, 0.10 mmol) was added to a stirred solution of N-arylsulfonyl-S-methylisothiourea (0.10 mmols, prepared in Part 2 of Example 1) and an amine (0.15 mmol) in DMF contained in a 15 ml screw cap vial. The reaction mixture was heated in a sand bath, and the progress of the reaction was monitored by TLC. After completion of the reaction, the mixture was cooled to room temperature followed by dilution with 15 ml of ethyl acetate. The reaction mixture was poured into 25 ml of water, and the organic layer was separated. The aqueous layer was extracted with 10 ml of ethyl acetate, and the combined extracts were washed twice with 15 ml of water. The solvent was then evaporated by drying over sodium sulfate. The crude product was purified by passing the product through a short silica gel column using hexane and diethyl ether as eluents. Tables 3 and 4 set forth the particular amines which were guanylated in this series of tests as well as the resulting guanidines and percent yields of those guanidines. Schemes F and G outline the general reaction taking place when guanidine is reacted with the particular N-arylsulfonyl-S-methylisothiourea. ##STR29##
TABLE 3__________________________________________________________________________Guanylation of amines with N-(p-toluenesulfonyl)-S-methylisothiourea. Reaction Entries Amine Guanidine time Reaction temp. Yield (%)__________________________________________________________________________ 1 #STR30## 8 h 100° C. 79 - 2 #STR31## 10 h 100.degre e. C. 91 - 3 #STR33## 18 h 100.degre e. C. 85__________________________________________________________________________ ##STR35##
TABLE 4__________________________________________________________________________Guanylation of amines with N-(2,3,6-trimethyl-4-methoxybenzene sulfonyl)- S-methylisothiourea. Reaction Reaction Entries Amine Guanidine time temp. Yield (%)__________________________________________________________________________ 1 26 906## ° C. 89 - 2 #STR37## 18 90° C. 92 - 3 #STR39## 36 90° C. 78__________________________________________________________________________
Example 4
Guanylation of Amines with N,N'-diphenyl-S-methylisothiourea and N,N'-diphenyl-S-benzylisothiourea
Nickel-boride alloy (13 mg, 0.10 mmol) was added to a solution of N,N'-diphenyl-S-methylisothiourea (24 mg, 0.10 mmol, prepared in Part 3 of Example 1) and an amine (0.15 mmol) in DMF contained in a 15 ml screw cap vial. The mixture was heated in a sand bath, and the progress of the reaction was monitored by TLC. After completion of the reaction, the reaction mixture was cooled to room temperature and diluted with ethyl acetate (15 ml). The organic layer was separated, and the aqueous layer was extracted with 10 ml of ethyl acetate. The combined organic extracts were washed twice with 15 ml portions of water, followed by drying over sodium sulfate. The residue was passed through a short silica gel column using a gradient of hexane and ethyl acetate as eluents to give the corresponding pure guanidine.
Scheme H outlines the general reaction scheme when aliphatic and benzylic amines were guanylated with N,N'-diphenyl-S-methylisothiourea. Table 5 lists the particular amines that were guanylated as well as the resulting guanidines and the yields of those guanidines. ##STR41##
TABLE 5__________________________________________________________________________Guanylation of aliphatic and benzylic amines with N,N'-diphenyl-S-methylisothiourea.Entries Amine Guanidine Reaction time Reaction temp. Yield (%)__________________________________________________________________________ 1 #STR42## 8 h 80° C. 96 - 2 #STR43## 15 h 80° C. 98 - 3 #STR45## 18 h 80° C. 98 - 4 #STR47## 18 h 80° C. 95 - 5 #STR49## 3 h 100.degre e. C. 95 - 6 #STR51## 17 h 100.degre e. C. 97 - 7 #STR53## 7 h 100.degre e. C. 94 - 8 #STR55## 7 h 100.degre e. C. 95__________________________________________________________________________
The guanylation of aromatic amines with N,N'-diphenyl-S-methylisothiourea is outlined in Scheme I, while Table 6 sets forth the particular amines which were guanylated as well as the resulting guanidines. Methylene chloride was utilized during the work-up procedures in place of ethyl acetate in these procedures. ##STR57##
TABLE 6__________________________________________________________________________Guanylation of aromatic amines with N,N"-diphenyl-S-methylisothiourea.EntriesAmine Guanidine Reaction time Reaction temp. Yield (%)__________________________________________________________________________ 1 #STR58## 6 h 65° C. 98 - 2 #STR59## 15 h 65.degree . C. 89 - 3 #STR61## 15 h 65.degree . C. 91__________________________________________________________________________
Scheme J outlines guanylation reactions of pyrrolidine with N,N'-diphenyl-S-methylisothiourea in various solvents. Table 7 sets forth the particular solvents that were utilized. Methylene chloride was used during the work-up procedures in place of ethyl acetate in this set of procedures. ##STR63##
TABLE 7______________________________________Guanylation of pyrrolidine with N,N'-diphenyl-S-methylisothiourea in different reaction conditions. Reaction Reaction Yield Entries Solvent(s) time temp. (%)______________________________________1 DMF 3 h 100° C. 95 2 THF 5 h 60° C. 100 3 THF-H.sub.2 O (3:1) 3 h 60° C. 100 4 DMSO 18 h room temp. 100 5 DMSO-H.sub.2 O (3:1) 4 h room temp. 100______________________________________
Scheme K shows the general reaction for the guanylation of amines with N,N'-diphenyl-S-benzylisothiourea, while Table 8 sets forth the structure of the particular amines that were guanylated as well as the resulting guanidines and their respective percent yields. ##STR64##
TABLE 8__________________________________________________________________________Guanylation of amines with N,N"-diphenyl-S-benzylisothiourea.Entries Amine Guanidine Reaction time Reaction temp. Yield (%)__________________________________________________________________________ 1 #STR65## 8 h 80° C. 91 - 2 #STR66## 10 h 80° C.__________________________________________________________________________ 88
EXAMPLE 5
Guanylation of Pyrrolidine in Presence of Varying Molar Concentrations of Nickel-Boride
N,N'-Bis-tert-butoxycarbonylthiourea was prepared as described in Part 1 of Example 1. Pyrrolidine was then guanylated at room temperature as described in Part 2 of Example 2 during the course of five test runs, with nickel-boride being present at nickel molar percents of 100 mol %, 50 mol %, 25 mol %, 10 mol %, and 5 mol % (all based on the total moles of N,N'-Bis-tert-butoxycarbonylthiourea taken as 100% by weight), respectively, during the test runs. The reaction scheme followed was identical to Scheme E above, with DMSO being the solvent. Table 9 sets forth the results of these runs.
TABLE 9______________________________________Guanylation of pyrrolidine with N,N'-bis-tert-butoxycarbonylthiourea in the presence of varying molar concentrations of nickel-boride. Nickel-Boride Reaction Entries (mol %) .sup.a Time Yield (%)______________________________________1 100 1 h 100 2 50 1 h 100 3 25 11/2 h 100 4 10 2 h 100 5 5 4 h 100______________________________________ .sup.a Nickel molar percent based upon the total moles of N,N'-Bistert-butoxycarbonylthiourea as 100%.
These results indicate that the nickel(0) derived from the nickel-boride acts as a catalyst during the guanylation reactions.
EXAMPLE 6
Guanylation of Pyrrolidine in the Presence of Various Nickel Catalysts
In this example, several commercially available nickel catalysts were tested to determine their effectiveness. Those catalysts were: nickel-phosphide alloy; aluminum-nickel alloy; nickel on kieselguhr; and nickel on silica/alumina. In each of the tests, 1 equivalent of N,N'-bis-tert-butoxycarbonylthiourea, 1.5 equivalents of pyrrolidine, and 1 equivalent of nickel catalyst in DMSO were utilized. Each reaction was carried out at room temperature. The data from these tests are recorded in Table 10.
TABLE 10______________________________________Guanylation of Pyrrolidine with N,N'-bis-tert-butoxycarbonylthiourea in the presence of various nickel catalysts. Reaction Yield Entries Nickel Catalyst Time (%)______________________________________1 nickel-phosphide 1 h 100 2 aluminum-nickel 1 h 100 3 nickel, ˜60 wt. % on kieselguhr 45 min. 100 4 nickel, ˜65 wt. % on silica/alumina 30 min. 100______________________________________
All of the nickel catalysts worked well and gave the corresponding guanidines in quantitative yields. The reactions were much faster when nickel on silica/alumina and nickel on kieselguhr were utilized as the catalysts compared to nickel-phosphide and aluminum nickel catalysts, with the reaction utilizing nickel on silica/alumina being extremely rapid. Commercially, aluminum-nickel catalysts will likely be the most important due to their relatively low cost. Finally, in comparing these results to those of Example 5, the catalysts listed in Table 10 would be effective in catalytic amounts as was the case with the nickel-boride. | An improved method for guanylating amines is provided. Broadly, the amines are reacted with a guanylating agent in the presence of a nickel catalyst. Preferably, the nickel catalyst comprises nickel in the zero oxidation state. Suitable nickel(0) catalysts are derived from nickel-boride alloys, nickel-phosphide alloys, aluminum-nickel alloys, nickel on kieselguhr, and nickel on silica/alumina catalysts. Preferred guanylating agents are thioureas and isothioureas. In one embodiment, protecting groups are selectively attached to the guanylating agents to yield particular substituted guanidines. The preferred protecting groups are Boc groups, Cbz groups, and arylsulfonyl groups. The reactions are particularly well suited for guanylating primary and secondary amines. The methods of the invention can be carried out under ambient conditions to provide high yields of the corresponding guanidines, with the nickel catalyst being essentially completely recoverable for reuse. | big_patent |
BACKGROUND OF THE INVENTION
1. FIELD OF THE INVENTION
The present invention relates to a novel apparatus and a method for continuously electrolytic coloring of strips or wires of aluminum or aluminum base alloys (hereinafter, for brevity, both aluminum and aluminum alloys will be designated "aluminum" in this specification). More particularly, the invention relates to an apparatus of continuously conducting a first anodic oxidation of aluminum strips or wires and then an electrolytic coloration of the anodic coating thus obtained.
2. DESCRIPTION OF THE PRIOR ART
For continuously coloring the anodic coating of aluminum strips or wires, a method has hitherto been employed in which an aluminum strip or wire is subjected to a degreasing treatment as a pre-treatment, and after forming an oxide film or layer on the aluminum strip or wire by an anodization, the anodized article is continuously immersed in a dyeing bath containing an organic dye. This method is useful in that aluminum strips or wires of various desired colors can be obtained in a comparatively short period of time but has the defects that the colored aluminum articles obtained by the method are poor in weatherability and are faded by exposure for a long period of time. Therefore, such a conventional method is unsuitable for building materials, etc., which have recently become in great demand.
On the other hand, as a method of obtaining a colored anodic coating on an aluminum surface having a high resistance to weathering, a method in which aluminum articles are anodized in an electrolytic bath containing an organic acid such as sulfosalicylic acid and a method in which articles of an aluminum alloy containing chromium and manganese are subjected to an anodization treatment in an aqueous sulfuric acid solution are known. In these known methods, the formation of the anodic oxide film or layer and the coloring of the oxide film or layer are conducted simultaneously in the same bath but there is a difficulty that insufficient coloring is achieved if the thickness of the oxide film or layer formed on the aluminum article or aluminum alloy article is less than about 15 microns although the extent of coloring depends on the electrolytic conditions and the nature of the aluminum alloy. Therefore, in order to obtain desirable coloring using such known methods, a large amount of electrical energy is required and further since the oxide film formed by such methods has a high hardness, the oxide film formed on an aluminum strip or wire tends to be cracked when the aluminum article is continuously withdrawn from the anodic oxidation bath, which makes these prior art methods unsuitable for continuous treatment.
We have previously discovered an improved method of coloring aluminum articles by anodizing the aluminum articles in an anodic oxidation bath to form an anodic coating on aluminum and then electrolytically coloring the oxide coating in an electrolyte containing a specific acid or water-soluble metal salt as disclosed in DT-OLS 2112927. By our previously discovered method, a colored oxide film or layer having high weatherability or fade resistance can be formed on aluminum or aluminum alloy article such as an aluminum plate without requiring a large amount of electrical energy.
As the results of further investigations, the inventors have found that the method previously discovered can be also applied to the continuous operation of electrolytic coloring of aluminum strips or wires and have discovered a novel and simple apparatus of the present invention suitable for the continuous formation of colored anodic oxide coatings having excellent weatherability or fade resistance on an aluminum strip or wire.
SUMMARY OF THE INVENTION
An object of this invention is, therefore, to provide an apparatus and a method for continuously conducting an anodic oxidation and an electrolytic coloring of an aluminum strip or wire without need for a large amount of electrical energy.
Another object of this invention is to provide an apparatus and a method for continuously conducting first an anodic oxidation and then an electrolytic coloring of an aluminum strip or wire for forming a colored anodic coating on the aluminum strip or wire, this film or layer having excellent weatherability or fade resistance.
Still another object of this invention is to provide an apparatus and a method for continuously conducting an anodic oxidation and an electrolytic coloring of an aluminum strip or wire without the necessity for connecting the continuously travelling aluminum strip or wire directly to a power source.
That is, the present invention provides an apparatus of continuous electrolytic coloring of an aluminum strip or wire comprising a means for continuously supplying an aluminum strip or wire, an anodic oxidation bath for anodizing the aluminum strip or wire and having a cathode disposed therein, an electrolytic coloring bath for electrolytically coloring the anodized aluminum strip or wire, this electrolytic coloring bath containing at least one of a nickel salt, a cobalt salt, a copper salt, a tin salt, and selenious acid and having an anode disposed therein, an electric circuit for connecting the cathode and the anode to a power source and causing the aluminum strip or wire to function as an anode in the anodic oxidation bath and to function as a cathode in the electrolytic coloring bath without connecting the aluminum strip or wire directly to a power source, and a means for passing the aluminum strip or wire continuously and successively through the baths.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
FIGURE illustrates one embodiment of this invention.
DETAILED DESCRIPTION OF THE INVENTION
The anodic oxidation bath composition used in this invention is usually an aqueous solution of 10 to 55% sulfuric acid, but if desired, the bath may further contain a small amount of a salt such as magnesium chloride, sodium sulfate, magnesium sulfate, sodium chloride, etc.; a carboxylic acid; an organic sulfonic acid; and/or an amine.
It is desirable that the thickness of the oxide film formed on an aluminum strip or wire by the anodic oxidation be thicker than 4 microns. That is, if the thickness of the oxide film is less than 4 microns, the oxide film formed on the aluminum strip or wire tends to not be colored by the electrolytic coloring treatment. If the thickness of the oxide film formed is 4 to 5 microns, the film can be colored a comparatively light color and if the thickness is thicker than about 5.5 microns, the oxide film can be easily colored a deep color. However, with a thickness of the oxide film thicker than about 5.5 microns, the color tone obtained is substantially constant regardless of the thickness of the film. Therefore, in such a range of thickness, an aluminum strip or wire having quite stable or constant color is obtained by the present invention as compared with the conventional techniques in which the color of the oxide film formed depends greatly on the thickness of the oxide film. In general, it is preferable that the thickness of the oxide film formed on an aluminum strip or wire in the anodic oxidation bath of this invention be in a range of 4 to 15 microns when the anodic oxidation is conducted at room temperature or temperatures lower than room temperature but the thickness of the oxide film may be as thick as about 25 microns when the anodic oxidation is conducted at high temperatures since in such case an oxide film having comparatively high elasticity can be formed.
The electric current used in the anodic oxidation can be a direct current or direct and alternating superposed currents and in the latter case the occurrence of local dissolution of the oxide film formed can be prevented.
The aluminum strip or wire having the oxide film or layer formed in the anodization is, then, continuously immersed in an electrolytic bath containing at least one of a nickel salt, a cobalt salt, a copper salt, a tin salt, and selenious acid prior to the sealing treatment. If necessary, the electrolytic bath may contain at least one of ammonium chloride, ammonium sulfate, boric acid, sulfuric acid, an organic acid, etc., for controlling the conductivity and pH thereof.
The bath composition for the electrolytic coloring bath used in this invention is selected suitably from the above-described components depending on the desired color. For example, specific examples of the components used for the bath composition are nickel sulfate, nickel chloride, cobalt sulfate, cupric chloride, stannous sulfate, and selenious acid and by the combinations of the electrolytic conditions and the aforesaid components, various colors can be obtained.
For example, when nickel sulfate or nickel chloride is used for the electrolytic bath, a color in the range of yellow-brown, brown, to black brown is obtained; when cobalt sulfate is used, the color substantially similar to the use of nickel sulfate is obtained; when cupric chloride is used, a red-brown color is obtained; and when stannous sulfate is used, a color in a range of yellow-brown, brown, black-brown, to black is obtained. Furthermore, when selenious acid is used, a color in a range of yellow to redish orange is obtained.
The aluminum strip or wire immersed continuously in the electrolytic coloring bath is rendered capable of functioning as a cathode indirectly by the action of the electrode disposed in the bath and is electrolyzed by direct current in the bath.
The current density and the electrolytic period of time in the bath are controlled by the area of the aluminum strip or wire immersed, the amount of electric current applied, and the period of immersion of the aluminum strip or wire.
An example of the change of colors obtained by the combinations of the electrolytic bath composition and the electrolytic conditions is illustrated below. That is, when an aluminum strip or wire having an oxide film of 8 microns thick formed thereon is immersed in an aqueous solution containing 50 g/liter of nickel sulfate and 30 g/liter of boric acid at 25° C, the oxide film can be colored yellow brown to black brown within 3 minutes of electrolysis.
For example, when the electrolysis is conducted at a current density of 0.2 to 0.3 ampere/dm 2 , the oxide film is colored black brown by an electrolysis of 2 to 2.5 minutes; when conducted at 1 ampere/dm 2 , the film is colored brown by an electrolysis of 30 seconds; when conducted at 1.5 amperes/dm 2 , the film is colored yellow brown by an electrolysis of 10 seconds; and when conducted at 2.0 amperes/dm 2 , the film is colored yellow brown by an electrolysis of 5 seconds. Also, in general, the higher is the current density employed, the more uniform is the color obtained.
Moreover, when a small amount of sulfuric acid or ammonium chloride is added to the electrolytic bath, the conductivity of the electrolytic bath increases to make it difficult to obtain a deep brown color but the change in color caused by the changes in current density and the period of time the electrolysis becomes less, which facilitates the continuous coloring operation.
The apparatus of this invention will be explained practically by the embodiment illustrated in the accompanying drawing but it is to be understood that various modifications within the scope of this invention are also employed in this invention in addition to the embodiment shown below.
As schematically shown in the FIGURE, an aluminum strip or wire 1 is continuously supplied from a supply roll or a recoiler 2, passed successively through a degreasing bath 3, an etching bath 4, a current supplying bath 5, an anodic oxidation bath 6, an electrolytic coloring bath 7, and a sealing bath 8, and is rolled up or recoiled on a wind-up roll or recoiler 9. If desired, several wash baths 10 and drive rollers 11 may be disposed between the aforesaid baths as illustrated in the FIGURE and guide rollers 12 are also disposed suitably for enabling the smooth passage of the aluminum strip or wire through each bath. The negative terminal of a d.c. power source 13 is connected to an electrode 14 disposed in the anodic oxidation bath 6 and the positive terminal is connected through a rheostat 17 to an electrode 15 disposed in the current supply bath 5 and through a rheostat to an electrode disposed in the electrolytic coloring bath 7. Using the rheostats 17 and 18, the electric current supplied to the current supply bath 5 and the electrolytic coloring bath 7 can be controlled, respectively, whereby the electric current in the anodic oxidation bath 6 can also be changed.
In the embodiment of the apparatus of this invention as described above, the aluminum strip or wire 1 supplied from the supply roll or recoiler 2 is first continuously introduced in the degreasing bath 3 by means of the first drive rollers 11. Plural supply rolls or recoilers 2 can be employed for treating plural aluminum strips or wires simultaneously. The degreasing bath 3 contains an organic solvent, an aqueous 5-25% sulfuric acid solution, or a neutral detergent solution for removing oils and fats from the surface of the aluminum strip or wire and is maintained at a definite temperature at use.
The aluminum strip or wire 1 from the surface of which oils and fats have been removed is, then, introduced into the etching bath 4 through the wash bath 10 disposed between the degreasing bath 3 and the etching bath 4. The etching bath is employed for slightly etching the aluminum strip or wire to provide a matt surface and contains usually an aqueous solution of sodium hydroxide, potassium hydroxide, or sodium carbonate or a chemical etching solution.
The aluminum strip or wire, the surface of which has been etched or chemically matted is, then, introduced into the current supply bath 5 through the wash bath 10. The current supply bath is employed for controlling independently the amount of electric current supplied to the anodic oxidation bath 6 and the electrolytic coloring bath 7 and in the bath the aluminum strip or wire acts as a cathode to the electrode 15 through the electrolyte in the bath without being connected to the power source. Thus, hydrogen gas is generated on the surface of the aluminum and electrolytic degreasing of the aluminum article is also accomplished in the bath. The electrolyte used in the current supply bath 5 is an aqueous solution of about 10 to 30% sulfuric acid or an aqueous solution of about 3 to 30% sodium hydroxide or potassium hydroxide. It is desirable, however, in the case of using an aqueous solution of sodium hydroxide or potassium hydroxide, to employ means of preventing the sodium ion or potassium ion from entering the electrolytic coloring bath 7, such as, for example, shower, spray, etc.
In another embodiment of the apparatus of this invention, the current supply bath 5 can be omitted by supplying an electric current to the anodic oxidation bath 6 and the electrolytic coloring bath 7 so that the amount of electric current is the same in the both baths and controlling the electrolytic conditions in each bath by controlling the immersion period or the immersion area of the aluminum strip or wire introduced into each bath.
The aluminum strip or wire passed through the current supply bath 5 is, then, introduced into the anodic oxidation bath 6, in which it acts as an anode to the electrode 14 connected to the power source 13. In employing a direct current and an alternating current simultaneously, a known d.c. -- a.c. superposing power source may be used in place of the d.c. power source 13.
The anodic oxidation bath 6 is for forming an oxide film on the aluminum article and an aqueous solution of sulfuric acid is usually used as the electrolyte. In the bath, the anodic oxide film having a thickness thicker than 4 microns is formed on the aluminum strip or wire. The thickness of the oxide film formed on the surface of the aluminum strip or wire in the anodic oxidation bath is controlled by the amount of electric current passing per unit area of the aluminum article. The bath temperature also influences the thickness of the oxide film but is sufficient in the range of room temperature to about 40° C.
The aluminum strip or wire passed through the anodic oxidation bath 6 is, then, introduced in the electrolytic coloring bath 7 through the wash bath 10 and it acts in the bath 7 as a cathode to the electrode 16 connected to the power source. The electrolytic coloring bath 7 is for coloring the anodized aluminum strip or wire by d.c. electrolysis and contains an aqueous solution of at least one of a nickel salt, a cobalt salt, a copper salt, a tin salt, and selenious acid. The d.c. current passes from the anode 16 to the anodic oxidation bath 6 through the coloring electrolyte and the aluminum strip or wire. A part of the d.c. current also passes from the current supply bath 7 to the anodic oxidation bath 6. To control the amount of the electric current in each route, the rheostat 17 and the rheostat 18 are employed. Also, the control of the current density and the control of the period of time of electrolysis are easily accomplished by adjusting the position of the guide rollers 12 in the electrolytic coloring bath 7, controlling the value of the rheostat 18, and controlling the travelling speed of the aluminum strip or wire. Therefore, the number of rheostats employed in this invention can be a single rheostat even though two rheostats are employed in the embodiment illustrated in the FIGURE and further two power sources can be employed for the anodic oxidation bath and the electrolytic coloring bath, respectively.
Also, to accomplish effectively the coloring treatment in the electrolytic coloring bath 7, it is desirable to stir the electrolyte in the bath and the stirring can be by air stirring, by circulation of the electrolyte, or by using one or more stirrers.
In the present invention, the distance between the electrodes in the electrolytic coloring bath 7, that is, the distance between the travelling aluminum strip or wire and the anode 16 substantially does not influence the color of the oxide film but the potential between them is influenced by variations in the distance.
The aluminum strip or wire passed through the electrolytic coloring bath 7 is introduced in the sealing bath 8 through the wash bath 10. The sealing bath 8 is employed for accomplishing a conventional sealing treatment, such as a treatment with boiling water or a treatment with an aqueous solution containing an inorganic salt such as nickel acetate. If desired, a plurality of baths for this purpose can be employed and further a coating of a lacquer can replace the sealing treatment. In this case, a dryer, a coating means, and a heat dryer are used in place of the sealing bath 10.
The aluminum strip or wire thus subjected to the sealing treatment or lacquer coating is rolled up on a wind-up roll or a recoiler 9.
The electrodes 14, 15, and 16 can be a carbon plate or an insoluble lead alloy plate but in particular it is preferable to select the electrode 16 considering the composition of the electrolytic coloring bath. For example, when an electrolyte containing a nickel salt is used for the electrolytic coloring bath, the use of a nickel plate as the anode 16 facilitates a control of the electrolytic bath composition.
Also, for increasing the washing effect of the wash baths disposed at various positions, a water spray means can be used together or a water spray means alone can be used in place of the wash baths in this invention.
Furthermore, it is desirable that the surfaces of the drive rollers 11 and the guide rollers 12 employed in the apparatus of this invention be coated with a material having an excellent insulating property and a resistance to corrosion.
As described above, the apparatus of this invention can produce continuously and with a low cost aluminum strips or wires having colored oxide films or layers thereon superior in weatherability or fade resistance and hence the industrial value of the apparatus is quite high.
While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof. | An apparatus comprising means for continuously supplying an aluminum strip or wire, an anodic oxidation bath for anodizing the aluminum strip or wire to form thereon an oxide film or layer, an electrolytic bath for coloring the oxide film or layer, and means for permitting the aluminum strip or wire to act as an anode in the anodic oxidation bath and as a cathode in the electrolytic bath without connecting the aluminum strip or wire directly to a powder source, and a method for electrolytic coloring of aluminum articles. | big_patent |
FIELD OF THE INVENTION
The present invention relates to a process of producing transgenic plants transformed on a chromosome. Further the invention relates to a process of screening nucleotide sequences for a desired phenotype in plants. The invention also relates to transgenic plants and to libraries of plants or plant seeds obtained or obtainable according to the processes of the invention. Further, the invention relates to vectors for these processes and to plants or plant cells transformed therewith.
BACKGROUND OF THE INVENTION
Currently used methods of stable plant transformation usually employ direct (microprojectile bombardment, electroporation or PEG-mediated treatment of protoplasts, for review see: Gelvin, S. B., 1998, Curr. Opin. Biotechnol., 9, 227-232; Hansen & Wright, 1999, Trends Plant Sci., 4, 226-231) or Agrobacterium -mediated delivery of pre-engineered DNA fragment(s) of interest into plant cells. Manipulations with said DNA vectors in planta are restricted to simplifying the resolution of complex integration patterns (U.S. Pat. No. 6,114,600; Srivastava & Ow, 2001, Plant Mol Biol., 46, 561-566; Srivastava et al., 1999, Proc. Natl. Acad. Sci. USA, 96, 11117-11121) or removal of auxiliary DNA sequences from vectors stably integrated into chromosomal DNA. The methods of stable Agrobacterium -mediated integration of T-DNA regions within plant cells use whole desired DNA fragment flanked with left (LB) and right (RB) border sequences necessary for T-DNA transfer and integration into the host chromosomal DNA (U.S. Pat. No. 4,940,838; U.S. Pat. No. 5,464,763; EP0224287; U.S. Pat. No. 6,051,757; U.S. Pat. No. 5,731,179; WO9400977; EP0672752). In most cases, the approaches are directed to the integration of one specific T-DNA region into the chromosomal DNA. Also, co-integration of two or more different T-DNA regions was tried (U.S. Pat. No. 4,658,082). The latter approach is used for segregating different T-DNAs in progeny for various purposes. For example, Komari and colleagues (U.S. Pat. No. 5,731,179) describe a method of simultaneously transforming plant cells with two T-DNAs, one carrying a selectable marker functional in plants, while another T-DNA contains a desired DNA fragment to be introduced into plant cells.
In general, the DNA regions designed for stable integration into plant cells are pre-engineered in vitro by employing standard molecular biology techniques (Sambrook, Fritsch & Maniatis, 1989, Molecular cloning: A laboratory manual, 2nd ed. Cold Spring Harbor, N.Y.: CSH Laboratory Press). Also, in vivo engineering in bacterial cells is used, for example in order to assemble the binary vector with the help of homologous recombination (U.S. Pat. No. 5,731,179). Manipulations with T-DNA in planta are restricted to T-DNA regions pre-integrated into a chromosome like removing certain sequences from T-DNA, e.g. sequences encoding selectable markers including morphological abnormality induction genes. The removal of unwanted DNA fragments from T-DNA regions occurs either with the help of site-specific recombination (WO9742334; Endo et al., 2002, Plant J., 30, 115-122) or by means of transposition (U.S. Pat. No. 5,792,924).
Site-specific recombination has been used for removing auxiliary sequences from T-DNA regions. Although site-specific recombinase/integrase-mediated DNA excision is more efficient than integration, the selection for excision events is a necessity, which leads to an additional step of tissue culture or screening of progeny for desired recombination events. In summary, all processes of manipulation with T-DNAs stably integrated into plant chromosomes are time-consuming, unflexible, and in general restricted to simple excision (with less efficiency—to integration) of desired DNA fragments. In addition, these processes are usually very limited in combinatorial diversity, as they are restricted to simple manipulations with a limited number of known genes and regulatory elements.
Offringa et al. (EMBO J. (1990), 9, 3077-3084) have described an extrachromosomal homologous recombination event between two Agrobacterium -delivered T-DNAs in plant cells followed by integration of the recombination product into nuclear DNA. The extrachromosomal homologous recombination efficiency between the co-delivered T-DNAs in the plant cell was however too low to have practical applications for vector engineering in vivo and was therefore used as control experiment in scientific studies of the mechanism of homologous recombination in plants (Offringa et al., 1990, EMBO J., 9, 3077-3084; Tinland et al., 1994, Proc. Natl. Acad. Sci. USA, 91, 8000-8004; Puchta et al., 1996, Proc. Natl. Acad. Sci. USA, 93, 5055-5060). The frequency of homologous recombination followed by integration into chromosomal DNA was approximately 1% of the plant co-transformation frequency with two T-DNAs (Offringa et al., 1990, EMBO J., 9, 3077-3084; Tinland et al., 1994, Proc. Natl. Acad. Sci. USA, 91, 8000-8004; Puchta et al., 1996, Proc. Natl. Acad. Sci. USA, 93, 5055-5060). Due to the low overall efficiency of this process, practical applications of this method have not been developed.
The frequency of targeted integration of transiently delivered T-DNA into a pre-engineered loxP site in plants is also very low. For example, Vergunst and colleagues (1998, Nucl. Acids Res., 26, 2729-2734) demonstrated that the frequency of Cre-mediated site-specific integration of an Agrobacterium -delivered T-DNA fragment of interest into a genomic T-DNA region with a loxP site is within the range of 1.2-2.3% of the number of random integration events. Due to this low efficiency, such integration processes require an additional selection round and the use of tissue culture to recover the cells carrying recombination events. In contrast to that, the frequency of chromosomal double-stranded DNA rearrangements with the help of site-specific recombinases is significantly higher and occurs in 29-100% of all plant germ cells (Zuo et al., 2001, Nature Biotechnol., 19, 157-161; Luo et al., Plant J., 23, 423-430). This is not surprising, as site-specific integrases/recombinases require double stranded DNA substrate for recognition of recombination sites and performing the reaction of site-specific recombination (Panigrahi et al., 1992, Nucleic Acids Res., 20, 5927-5935; Martin et al., 2002, J. Mol. Biol., 19, 107-127; Thorpe et al., 2000, Mol. Microbiol., 38, 232-241).
All data mentioned above suggest that T-DNA transiently delivered into the plant cell is a poor substrate for site-specific recombinases.
In a previous invention, we have overcome the above-described low efficiency by site-specific recombination-mediated assembly of RNA-viral amplicons (WO02/088369). The assembled viral amplicons were capable of strong autonomous amplification, cell-to-cell and systemic movement and, therefore, could strongly amplify the rare recombination events. Said viral amplicons were assembled in planta from two or more vectors by recombinase-mediated site-specific recombination and contained a gene of interest to be expressed transiently with the aim of achieving the strongest possible expression of the gene of interest throughout a plant that was infected by said vectors. However, expression of gene of interest was transient; stable transformation of plant chromosomes for stable and inheritable expression of a gene of interest was not addressed.
For many applications, the methods described in WO02/088369 can, however, not be used due to the following problems: Amplification and spread of the viral amplicon leads to viral disease symptoms that compromise plant health. Therefore, these methods cannot be used for gene function determination (functional genomics) since disease symptoms frequently obscure the function of a gene to be determined or prevent expression of the function to be determined. Further, expression of a gene of interest from an amplicon gives rise to unnaturally high expression levels leading to phenotypes different from the natural phenotype of that gene, perhaps due to unnatural interactions with functions of native genes of that plant.
Therefore, it is an object of the invention to provide an efficient, rapid and highly versatile process for transforming a plant or plant cells on a chromosome, notably a nuclear chromosome, whereby genetically stable transgenic plants or plant cells may be produced. It is another object of the invention to provide a process of producing transgenic plants transformed on a chromosome, whereby (e.g. for reducing cloning work) the DNA sequences to be integrated in said chromosome can be engineered in planta. It is a further object to provide a process of stably transforming plants or plant cells on a chromosome with a DNA sequence of interest having toxic effects on bacteria normally used for cloning said DNA sequence of interest. It is another object of the invention to provide a process of genetic transformation of plant nuclear DNA, which allows for screening for an optimal expression unit of a gene of interest. It is a further object to provide a process of stably transforming plants or plant cells on a chromosome, whereby vectors can be used in a modular fashion, for reducing the cloning work and the overall size of the vector molecules. It is another object of the invention to provide a process of stably transforming plants or plant cells on a chromosome, whereby said process allows screening of DNA libraries for desired functions in plants. It is further object of the invention to provide an in planta process of shuffling genetic elements/gene fragments, whereby said process is linked with a process of stably transforming plants or plant cells with a DNA sequence of interest resulting from said shuffling.
GENERAL DESCRIPTION OF THE INVENTION
The above objects are achieved by a process of producing transgenic plants or plant cells transformed on a chromosome with a DNA sequence of interest and capable of expressing a function of interest from said DNA sequence of interest, said process comprising:
(a) providing plant cells or plants with at least two different vectors, whereby
(i) said at least two different vectors are adapted to recombine with each other by site-specific recombination in said plant cells for producing a non-replicating recombination product containing said DNA sequence of interest, (ii) said at least two different vectors are adapted for integrating said DNA sequence of interest into said chromosome, (iii) said DNA sequence of interest contains sequence portions from at least two of said at least two different vectors, said sequence portions being necessary for expressing said function of interest from said DNA sequence of interest; and
(b) selecting plants or plant cells expressing said function of interest.
The invention further provides transgenic plants or parts thereof (like seeds) produced or producible by the process of the invention. Further, libraries of plants or plant seeds obtained or obtainable by this process are provided. The process of the invention has many important applications, among which its use in DNA library screening, gene function analysis and functional genomics, and directed evolution including gene shuffling may be mentioned. Moreover, complex and/or large DNA sequences of interest to be introduced in a plant chromosome can be assembled in planta from smaller precursors (see FIG. 12 ). The process of the invention can, however, also be used for introducing a gene to be expressed in a chromosome of a plant cell or plant. In an important embodiment, all genes and/or coding sequences and/or expressible sequences of said DNA sequence of interest integrated into a chromosome are of plant origin, whereby no unnatural sequences can be outcrossed from the transgenic plants of the invention to other organisms.
The inventors of this invention have surprisingly found that transiently delivered T-DNA can be efficiently used for in planta engineering of a sequence of interest for integration into a chromosome. Preferably, the efficiency of achieving stable integration events is comparable to that for a standard Agrobacterium -mediated transformation. The reason for this unexpectedly high efficiency has not yet been elucidated. The overall process of the invention is of sufficient efficiency for enabling routine applications of the process of the invention. For example, screening of DNA libraries for a useful trait can for the first time be performed in planta with a low danger of missing library members that are not compatible with the prokaryotic systems used for cloning in traditional approaches. This allows to combine the processes of vector engineering (e.g. for functional genomics or directed evolution purposes) with the creation of stable transformants, thus significantly speeding up the process of screening for desired combinations of genetic elements under test.
The process of the invention allows to produce transgenic plants or plant cells that are stably transformed on a chromosome with a DNA sequence of interest, whereby said DNA sequence of interest derives from at least two different vectors. Stable transformation of a chromosome means integration of said DNA sequence of interest in said chromosome such that said DNA sequence of interest is replicated together with said chromosome. Preferably, said DNA sequence of interest can be inherited during cell division and organism reproduction for several generations.
In step (a) of the process of the invention, a plant or plant cells are provided with at least two different vectors, whereby said at least two different vectors are as defined below. Herein, “different vectors” means preferably “different types of vectors”. Plant cells may be provided with said at least two different vectors in issue culture, notably in tissue culture of plant cell protoplasts. Further, explants (e.g. root explants, leaf discs) of a plant may be provided with said at least two different vectors. Moreover, entire plants or parts of entire plants may be provided with said vectors.
Said providing of step (a) may be performed by a direct transformation method (e.g. particle bombardment, electroporation, PEG-mediated transformation of protoplasts) or by Agrobacterium -mediated T-DNA delivery, whereby Agrobacterium -mediated T-DNA delivery is preferred due to its superior efficiency in the process of the invention. Said at least two different vectors may be provided to said plant or said plant cells consecutively. However, said providing with said at least two different vectors is not separated by a cycle of reproduction of the transformed plant or a cycle of regeneration of a plant transformed with one vector followed by transformation with another vector of said at least two different vectors. Preferably, said plant or said plant cells are provided with said at least two vectors in a one-step procedure. In the case of direct vector delivery, this means that mixtures of said vectors are preferably used in step (a). In the case of Agrobacterium -mediated T-DNA delivery, mixtures of Agrobacterium strains (or cells) are preferably used, whereby each strain or cell contains a different Ti-plasmid, each Ti-plasmid containing a different vector of said at least two different vectors. Most preferably, a particular Agrobacterium strain contains one type of Ti-plasmid having a certain vector, but no Ti-plasmids containing a different vector, whereas another Agrobacterium strain contains another type of Ti-plasmid having another type of vector but not Ti-plasmids containing a different vector. I.e. no Agrobacterium cell provides more than one type of said at least two different vectors. Providing said plant cells or plants in a one step procedure with said vectors, notably simultaneously, is work-efficient and gives a good overall efficiency of the process of the invention.
After having provided said plants or said plant cells with said at least two different vectors, a recombination product containing said DNA sequence of interest is formed within plant cells by site-specific recombination between at least two of said at least two different vectors. For this purpose, each of said at least two different vectors is adapted to recombine with at least one other vector of said at least two different vectors. If three or more different types of vectors are used, each may be adapted to recombine with every other vector. For some applications, it may however be sufficient if each vector of said at least two different vectors is adapted to recombine with one other vectors of said at least two different vectors.
Said adaption to recombination may be achieved by including site-specific recombination site(s) on said vectors for enabling said site-specific recombinations. Preferably, said site-specific recombination is adapted such that the reversion (i.e. the back reaction) of said site-specific recombination occurs with low probability. This may e.g. be achieved by providing the enzyme for said recombination transiently (e.g. by rendering the recombinase gene non-expressible by said recombination). More preferably, a site-specific recombinase/recombination site system is chosen that performs irreversible recombinations, which may be achieved by using an integrase together with the appropriate recombination sites. Integrases use two different recombination sites (like AttP and AttB in the case of phi C31 integrase), which allows directed and irreversible recombination.
A gene of a site-specific recombinase or integrase compatible with the selected site-specific recombination sites should be provided (e.g. with one of said at least two different. vectors) such that said recombinase or integrase can be expressed. Preferably, said recombinase or integrase gene is provided on one of said at least two different vectors such that (i) it can be expressed prior to the site-specific recombination event and (ii) such that its expression is blocked after said recombination has occurred. Alternatively, the plant cells or plants provided with said at least two different vectors in step (a) may already contain and express a gene coding for a recombinase or integrase.
By said site-specific recombination between said at least two different vectors, one or more different recombination products may be formed, whereby at least one recombination product contains said DNA sequence of interest. A recombination product containing said DNA sequence of interest is non-replicating in order to avoid disease symptoms due to strong replication of said recombination product. Preferably, all recombination products are non-replicating. Non-replicating means that the recombination product is not a viral nucleic acid capable of autonomous replication, since this generally produces disease symptoms that are incompatible with many applications like gene function determinations. Most preferably, said recombination product does not encode a functional viral replicase supporting replication of the recombination product.
Said DNA sequence of interest contains sequence portions from at least two of said at least two different vectors, whereby said sequence portions are necessary for expressing said function of interest from said DNA sequence of interest. While the DNA sequence of interest may contain three or more sequence portions of three or more different vectors, the DNA sequence of interest preferably contains two sequence portions of two vectors of said at least two different vectors. Recombination between said at least two different vectors may result in the formation of more than one recombination product. At least one recombination product contains said DNA sequence of interest. Other recombination products may be formed that do not contain said DNA sequence of interest.
Said DNA sequence of interest contains sequence portions from at least two of said at least two different vectors. At least two of said sequence portions are necessary for expressing said function of interest from said DNA sequence of interest. Therefore, said function of interest cannot be expressed, if only one vector is provided to said plant cells or said plant. Said DNA sequence of interest may of course also contain sequences deriving from said at least two different vectors that are not necessary for expressing said function of interest.
In a basic embodiment, said plant or said plant cells are provided with two different vectors and a recombination product containing said DNA sequence of interest is assembled from these two different vectors. Said DNA sequence of interest will then contain the two sequence portions of these two different vectors. In a more complex embodiment, said plant or said plant cells are provided with three or more different vectors, which allows the assembly of two or more recombination products each containing a different DNA sequences of interest. Each of said two or more different DNA sequences of interest is preferably assembled from two different vectors. This allows the production of two or more different transgenic plants or plant cells, each transformed on a chromosome with a different DNA sequence of interest. As an example, said plant or plant cell may be provided with three different (types of) vectors referred to as vector A, vector B, and vector C, said vectors containing sequence portions a, b, and c, respectively. Site-specific recombination between vector A and vector B allows assembly of DNA sequence of interest ab. Site-specific recombination of vector A and vector C allows assembly of DNA sequence of interest as. Thus, after segregation and/or selection, two different transgenic plants may be obtained, one being transformed on a chromosome with DNA sequence of interest ab and the other one being transformed on a chromosome with DNA sequence of interest ac. Depending on the arrangement of recombination sites on these three vectors, further DNA sequences of interest may be assembled (e.g. DNA sequences of interest bc, ba, ca, or cb) and further transgenic plants or plant cells may be produced accordingly, each being transformed on a chromosome with one of these DNA sequences of interest.
By providing plant cells or plants with many different vectors, a large number of different DNA sequences of interest (e.g. dozens, hundreds or even more different DNA sequences of interest) may be assembled and introduced into a chromosome for producing many different transgenic plants or plant cells. DNA libraries may in this way be provided to plants or plant cells. The transgenic plants or plant cells produced thereby may then be screened for a useful trait or a desired phenotype. It is in such screening methods where the full potential of the present invention can be made use of.
If three or more different types of vectors are used in the process of the invention, each vector may be adapted to recombine with all other of said at least two different vectors. In the above example with vectors A, B, and C, up to six different DNA sequences of interest may then be formed (ab, ac, bc, ba, ca, and cb). In this general embodiment, the largest combinatorial variety of DNA sequences of interest (and thus transgenic plants) may be formed. In a more special embodiment, a primary vector may be used in a mixture with a set of secondary vectors. Different DNA sequences of interest may then be formed, each containing a sequence portion from said primary vector and a sequence portion from a vector of said set of secondary vectors. The primary vector may e.g. provide sequences that render sequence portions of the secondary vectors expressible after assembly of a DNA sequence of interest containing a sequence portion of said primary vector and a sequence portion of a vector of said set of secondary vectors.
For producing transgenic plants or plant cells that are transformed on a chromosome with a DNA sequence of interest, said at least two different vectors are adapted for integrating said DNA sequence of interest into said chromosome. Said chromosome may be a nuclear chromosome, a plastid chromosome, or a mitochondrial chromosome. Nuclear and plastid chromosomes are preferred and a nuclear chromosome is most preferred. Said adaption for integration depends on the type of chromosome. For integrating said DNA sequence of interest in the plastid chromosome, i.e. the plastome, homologous recombination may e.g. be used. In this case, said vectors and/or the respective sequence portions are adapted such that the recombination product that contains said DNA sequence of interest also contains sequences homologous to plastome sequences for allowing integration of said DNA sequence of interest in the plastome. The sequences homologous to plastome sequences are preferably chosen such that integration takes place at a desired site of the plastome. Methods of plastome transformation are well-established for several plant species, see e.g. Svab et al., 1990 Proc Natl Acad Sci USA. 87, 8526-8530; Koop et al., 1996, Planta, 199, 193-201; Ruf et al., Nat Biotechnol. 2001, 19 (9):870-875; for a review see Maliga, P. 2002, Curr Opin Plant Biol., 5, 164-172; WO 02/057466.
Integration of a DNA sequence of interest into a nuclear chromosome may be achieved e.g. by site-targeted transformation into a pre-engineered integration site using site-specific recombination. Alternatively, said at least two different vectors are adapted such that said DNA sequence of interest or said non-replicating recombination product contains homology sequences that facilitate integration of said DNA sequence of interest into said chromosome by homologous recombination. Preferably, however, nuclear integration is achieved using Agrobacterial T-DNA left and right border sequences in said DNA sequence of interest (see further below and examples). For this purpose, said at least two different vectors are adapted such that said DNA sequence of interest in said non-replicating recombination product has T-DNA border sequences. One or all of said at least two different vectors may contain a functional cytokinin autonomy gene, whereas said DNA sequence of interest is preferably devoid of a functional cytokinin autonomy gene.
A transgenic plant or plant cells transformed on a chromosome with a DNA sequence of interest is capable of expressing a function of interest from said DNA sequence of interest Produced transgenic plants or plant cells that are not capable of expressing a function or that express a function that is not of Interest, may be eliminated in step (b) of the process of the invention. Regarding said function of interest, the process of the invention is not limited. Typically, said function of interest is encoded in a coding sequence contained in said DNA sequence of interest. Said function of interest may be a function of DNA, RNA (notably messenger RNA) or of a protein encoded in said DNA sequence of interest. Preferably, said function of interest is a function of RNA or of a protein encoded in said DNA sequence of interest and expression of said function requires transcription of a coding sequence in said DNA sequence of interest. If said function is a function of a protein encoded in said DNA sequence of interest, expression of said function requires transcription and translation of a coding sequence of said DNA sequence of interest. For said transcription and optionally said translation, the DNA sequence of interest should contain the control elements needed therefore, like a pomoter, a 5′-non-translated region, a 3′-non-translated region, and/or a polyadenylation signal, etc. Said function of interest may e.g. be an antibiotic resistance that may be used for said selection of step (b). More than one function of interest may be expressed from said DNA sequence of interest. Said function of interest is normally related to the reason for performing the process of the invention. Typically, a selectable marker used in step (b) of the invention is among the functions of interest that can be expressed from said DNA sequence of interest.
At least two sequence portions of at least two different vectors are necessary for expressing said function of interest from said DNA sequence of interest. Said function of interest is rendered expressible by assembling said DNA sequence of interest by site-directed recombination between at least two of said at least two different vectors. There are several possibilities how said function of interest can be rendered expressible according to the invention:
Said assembling of said DNA sequence of interest may e.g. bring a coding sequence encoding said function of interest under the control of a regulatory element (e.g. a promoter) necessary for expressing said coding sequence. Thus, a functional expression unit may be formed in said DNA sequence of interest by said assembly. This possibility is particularly preferred if the process of the invention is used for screening a large number of DNA sequences like a collection of DNA sequences (e.g. a library) for a useful trait. Said collection of DNA sequences may e.g. be differently mutated forms of a chosen coding sequence of a protein, whereby said differently mutated forms may e.g. be produced by randomly introducing mutations (e.g. by error-prone PCR or gene shuffling), and a mutant protein encoded by said chosen coding sequence having desired properties may be identified with the process of the invention. In such a screening process, a primary vector may provide said regulatory sequence(s) required for expressing a test sequence from said library and a set of secondary vectors each contains a different test sequence. In this way, a set of transgenic plant cells or plants may be produced each containing a different DNA sequence of interest, whereby these different plants or plant cells may be screened for a useful function of interest (a useful trait of interest) encoded in one of said test sequences.
Alternatively, the process of shuffling can be performed in planta during the process of site-specific recombination-mediated assembly of said DNA sequence of interest. As is shown in FIG. 1B , the vector families A n and B n may be libraries of different variants of structural/functional domains of a protein of interest. Joining said domains through site-specific recombination can create combinatorial diversity of the protein of interest generated in planta. The coding sequences of the diversified protein of interest are stably integrated into plant chromosomal DNA. A schematic representation of a vector most suitable for such shuffling is shown in FIG. 11 .
Another important embodiment allows screening for optimal regulatory sequences (e.g. a promoter) for optimally (in whichever sense) expressing a chosen coding sequence. In this case, a primary vector may provide said coding sequence and a set of different regulatory sequences are provided with a set of secondary vectors. Various transgenic plants or plant cells containing various DNA sequences of interest may be screened and a suitable regulatory element for expressing said chosen coding sequence may be found.
In a further embodiment, said assembling of said DNA sequence of interest may bring together fragments of a coding sequence that codes for a function of interest to be expressed. Preferably, two fragments of a coding sequence are brought together by said assembling, whereby each fragment is provided with a different sequence portion of a different vector. Preferably, each fragment of said coding sequence is not capable of expressing said function of interest in the absence of the other fragment. This may be easily achieved by splitting a coding sequence into two fragments such that each fragment contains a portion necessary for expressing the function of interest. Said two fragment may then be introduced in a vector, whereby two different vectors according to this invention are formed. Each sequence portion may provide some of the regulatory sequences required for expressing said coding sequence from said assembled DNA sequence of interest.
For rendering said coding sequence expressible, expression of said function of interest from said DNA sequence of interest may comprise intron-mediated cis-splicing. Said assembling may assemble concomittantly an intron, notably a self-splicing intron, such that splicing of an RNA expression product of said coding sequence results in an mRNA having both fragments properly connected to each other such that a desired protein may be correctly translated (e.g. as depicted in FIGS. 10 and 11 ). In more detail,
a first vector of said at least two different vectors may contain a first sequence portion that contains: a first part of a sequence coding for the function to be expressed and, downstream thereof, a 5′ part of an intron, and a second vector of said at least two different vectors may contain a second sequence portion that contains: a second part of a sequence coding for a function to be expressed and, upstream thereof, a 3′ part of an intron.
This important embodiment is also illustrated in the examples.
In step (b) of the process of the invention, transgenic plants or plant cells expressing said function of interest are selected. Said selecting may comprise applying an antibiotic or inhibitor suitable for said selectable marker to plant cells or plants obtained in step (a). Said selecting may also comprise screening for transformed plants or plant cells in which recombination between at least two of said at least two different vectors has occurred. Further, said selecting preferably comprises selection for integration of said DNA sequence of interest into said chromosome. Step (b) may also comprise allowing segregation of differently transformed plant cells, notably of plant cells containing different (e.g. differently assembled) DNA sequences of interest. Said selecting, and optionally said segregating, may comprise the use of a selectable marker gene e.g. on said DNA sequence of interest. For this purpose, said at least two different vectors may be adapted such that said DNA sequence of interest contains a selectable marker gene or another sequence that allows screening for transformed plants or plant cells containing said DNA sequence of interest.
Step (b) may be implemented by many different embodiments. A sequence portion of one of said at least two different vectors may contain a selectable marker, whereby said selectable marker is included in said DNA. sequence of interest by said assembling. In a strongly preferred embodiment, said selectable marker is turned on by said assembling of said DNA sequence of interest such that it provides an antibiotic resistance to plant cells containing said assembled DNA sequence of interest but it does not provide antibiotic resistance to cells in which said assembling has not occurred. Most preferably, the selectable marker gene cannot be transcribed in said plant cells from one of said at least two different vectors. This embodiment may be implemented such that said selectable marker is placed under the control of a genetic element, allowing transcription of said selectable marker gene after said assembling of said DNA sequence of interest, e.g. by placing the coding sequence of said selectable marker under the control of a promoter. Advantageously, an IRES (internal ribosome entry site) element may control translation of said selectable marker (cf. FIG. 11 ). References describing the use of IRES elements are given below.
In a further important embodiment, said transgenic plants or plant cells are screened for the absence of one or all of said at least two different vectors and/or for the absence of recombination products thereof with the exception of recombination products containing said DNA sequence of interest. With this embodiment, the production of transgenic plants or plant cells can be avoided that contain unnecessary foreign DNA sequences deriving from said at least two different vectors. These unnecessary foreign DNA sequences may disturb expression of said DNA sequence of interest or may compromise the determination of said function of interest (e.g. in functional genomics studies). This embodiment may be implemented with the use of a counter-selectable marker. Optionally, said screening may be supported by PCR analysis and selection of suitable transformants. At least one of said at least two different vectors may contain a counter-selectable marker gene or another sequence that allows efficient screening against transformed cells containing one of said at least two different vectors. Preferably, said at least two different vectors are adapted such that, after said recombination, said counter-selectable marker gene is contained in recombination products other than nucleic acid molecules containing said DNA sequence of interest. Said counter-selectable marker gene or said another sequence that allows efficient screening against transformed cells containing one or more of said at least two different vectors may advantageously be under translational control of an internal ribosome entry site (IRES) element.
The invention also provides transgenic plants or parts thereof like seeds produced by the process the invention. Preferably, all coding sequences and/or expressible sequences of said sequence of interest in said transgenic plants or parts thereof are of plant origin. Moreover, library of plants, of plant cells, or of plant seeds obtained or obtainable according to process of the invention are provided.
PREFERRED EMBODIMENTS OF THE INVENTION
A process of producing transgenic multi-cellular plants or plant cells stably transformed on a nuclear chromosome with a DNA sequence of interest and capable of expressing a function of interest from said DNA sequence of interest, said process comprising:
(a) providing plant cells or plants with at least two different vectors by Agrobacterium -mediated delivery, whereby
(i) said at least two different vectors are adapted to recombine with each other by site-specific recombination in said plant cells for producing a non-replicating recombination product containing said DNA sequence of interest, (ii) said at least two different vectors are adapted for integrating said DNA sequence of interest into said chromosome such that said DNA sequence of interest contains T-DNA border sequences, (iii) said DNA sequence of interest contains sequence portions from at least two of said at least two different vectors, said sequence portions being necessary for expressing said function of interest from said DNA sequence of interest; and
(b) selecting plants or plant cells expressing said function of interest.
A process of producing different transgenic multi-cellular plants or plant cells transformed on a chromosome, preferably a nuclear chromosome, with a DNA sequence of interest and capable of expressing a function of interest from said DNA sequence of interest, said process comprising the following steps (A) and (B):
(A) providing plants or plant cells with a mixture of
(i) a primary vector having a primary sequence portion a 1 and (ii) a set of n secondary vectors each having a secondary sequence portion selected from the set (b 1 , b 2 , . . . , b n ), whereby n is an integer of >1, said primary sequence portion a 1 is necessary for expressing the function of a secondary sequence portion (b 1 , b 2 , . . . , b n ), said primary vector and said secondary vectors are adapted such that said primary vector can recombine with every member of said set of n secondary vectors by site-specific recombination for producing recombination products containing different DNA sequences of interest of the type (a 1 b 1 , a 1 b 2 , . . . , a 1 b n ) or the type (b 1 a 1 , b 2 a 1 , . . . , b n a 1 ), said primary vector and said secondary vectors are adapted to integrate said DNA sequences of type (a 1 b 1 , a 1 b 2 , . . . , a 1 b n ) or type (b 1 a 1 , b 2 a 1 , . . . , b n a 1 ) into a chromosome,
(B) selecting transformed plants or plant cells expressing a function of interest, preferably from a DNA sequence of interest of type (a 1 b 1 , a 1 b 2 , . . . , a 1 b n ) or type (b 1 a 1 , b 2 a 1 , . . . , b n a 1 ).
Said different transgenic multi-cellular plants differ inter alia in that they contain different DNA sequences of interest Said recombination products containing a DNA sequences of interest may be replicating or non-replicating. Preferably, they are non-replicating as defined in the general description of the invention. Said mixture of primary and secondary vectors is preferably provided to said plant cells by a mixture of Agrobacterium cells, each cell providing one type of vector.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 shows the general scheme of in planta assembly of a DNA sequence of interest designed for stable integration into plant chromosomal DNA. RS stands for recombination sites.
FIG. 1A shows schematically the assembly of a DNA sequence of interest from two (precursor) vectors.
I—assembly of a DNA sequence of interest (AB) from two different vectors (A and B) by site-specific recombination.
II—assembly of a DNA sequence of interest (AB) from two precursor vectors (AA′ and B′B) that include helper sequences (A′ and B′) absent in said DNA sequence of interest (AB).
FIG. 1 B—shows schematically the assembly of a DNA sequence of interest from more than two different vectors.
I—assembly of a DNA sequence of interest having two-components (A n B n ) from a library of the precursor vectors A and B, where n is the number of precursor vectors in the library.
II—assembly of the three component DNA sequence of interest (ABC) from a library of the precursor vectors A, B and C. RS 1 and RS 2 are recombination sites recognised by different recombinases/integrases.
FIG. 2 depicts schematically the T-DNA regions of binary vectors pICBV19 and pICH10605. GUS—beta-glucuronidase gene; P35S—CaMV35S promoter; BAR—phosphinothricin acetyltransferase gene (pICH10605 has intron disrupting BAR coding sequences); PNOS—promoter of agrobacterial nopaline synthase gene; TNOS—transcription termination region of agrobacterial nopaline synthase gene; TOCS—transcription termination region of octopine synthase gene.
FIG. 3 depicts schematically the T-DNA region of binary vector pICH7410.
GFP—gene encoding green fluorescent protein; NPT—neomycin phoshotransferase II gene conferring resistance to kanamycin; POCS—promoter region of the agrobacterial octopine synthase gene; NTR—3′ non-translated region of tobacco mosaic virus (TMV) RNA; AttB—recombination site.
FIG. 4 depicts schematically the T-DNA regions of plasmids pICH11140 and pICH11150.
PACT2-i—promoter of the Arabidopsis actin2 gene with first intron.
FIG. 5 depicts the T-DNA regions of the binary vectors pICBV16 and pICH8430.
PACT2—promoter of the arabidopsis actin2 gene; TVCV polymerase—RNA-dependent RNA polymerase of turnip vein-clearing virus (TVCV); MP—tobamoviral movement protein; IRESmp75—IRES of crTMV movement protein.
FIG. 6 depicts schematically the T-DNA regions of the binary vectors pICH11160 and pICH11170.
FIG. 7 depicts schematically the T-DNA region resulting from site-specific recombination between T-DNAs of pICH11150 and pICH11170. This region carries a BAR gene interrupted by an intron containing an AttR site. Intron splicing after transcription allows expression of a functional BAR protein.
FIG. 8 depicts schematically the T-DNA regions of the binary vectors pICH12022 and pICH12031 designed for transformation of monocotyledonous plants. PUBQ—promoter of the maize ubiquitin gene; PACT1—promoter of the rice actin1 gene; IPT—gene coding for isopentenyl transferase.
FIG. 9 depicts schematically the T-DNA region resulting from site-specific recombination between T-DNA regions of binary vectors pICH12022 and pICH12031. The region carries a functional BAR gene with an intron under control of the rice actin1 promoter PACT1.
FIG. 10 depicts a scheme of assembling a DNA sequence of interest (C) from two precursor vectors (A and B) including assembly of a functional selectable marker gene from fragments of said selectable marker gene designated “Selectable” and “marker”. Concomittantly, an intron (designated “INTRON”) is assembled from intron fragments designated “INT” and “RON”. P—promoter; T—transcription termination region; CSM—counter-selectable marker; IRES—internal ribosome entry site.
FIG. 11 depicts a scheme of assembling a DNA sequence of interest (C) from two precursor vectors (A and B) including assembly of a functional gene of Interest from fragments of said gene of interest designated “Gene of” and “Interest”. A selectable marker under translational control of an IRES element is rendered expressible by said assembly by placing it under the transcriptional control of a promoter. Both precursor vectors A and B contain a counter-selectable marker gene CSM. By said assembling, CSM ends up in recombination product D that does not contain said gene of interest Using said CSM, transgenic plants or plant cells can be selected that do not contain precursor vector A, nor precursor vector B, nor recombination product D. P—promoter; T—transcription termination region; CSM—counter-selectable marker; IRES—internal ribosome entry site.
FIG. 12 depicts schematically assembly of a complex DNA sequence of interest C by site-specific recombination in planta of vectors A and B. P—promoter; T—transcription termination region; CSM—counter-selectable marker; IRES—internal ribosome entry site; Ds (3′ or 5′)—non-autonomous transposable element (Ds) ends recognised by the Ac transposase; dSpm (3′ or 5′)—non-autonomous transposable element (dSpm) ends recognised by Spm transposase; GOI—gene of interest.
FIG. 13 depicts schematically a method of generating different allelic vectors from a DNA sequence of interest assembled in planta according to FIG. 12 . P—promoter; T—transcription termination region; CSM—counter-selectable marker; IRES—internal ribosome entry site; Ds (3′ or 5′)—non-autonomous transposable element (Ds) ends recognised by Ac transposase; dSpm (3′ or 5′)—non-autonomous transposable element (dSpm) ends recognised by Spm transposase; GOI—gene of interest.
FIG. 14 depicts schematically the T-DNA regions of the binary vectors pICH15820 and pICH15850 designed for transformation of dicotyledonous plants. These vectors may be cotransformed into plants and complement each other according to the invention. PACT2-I—promoter of the Arabidopsis actin2 gene with intron; IPT—gene encoding for isopentenyl transferase; PIPT—IPT promoter; TIPT—IPT gene transcription termination region; NLS—nuclear localisation signal; TNOS—transcription termination region of agrobacterial nopaline synthase gene; TOCS—transcription termination region of octopine synthase gene.
FIG. 15 depicts schematically the T-DNA regions of binary vectors pICH17320 and pICH17330 designed for transformation of dicotyledonous plants. These vectors may be cotransformed e.g. with pICH15850 for performing the process of the invention. PSpm—promoter of Z. mays Spm transposase; PHsp81.1—promoter of the Arabidopsis HSP81.1 gene; IPT—gene encoding isopentenyl transferase; PIPT—IPT promoter; TIPT—IPT gene transcription termination region; NLS—nuclear localisation signal; TNOS—transcription termination region of the agrobacterial nopaline synthase gene; TOCS—transcription termination region of octopine synthase gene.
FIG. 16 depicts schematically vectors pICH15830, pICBV2, and pICH15840.
FIG. 17 depicts schematically vectors pICH13630, pICH15760 in (A), and pICH10881, pICH15770 in (B). The adipt3 and adipt4 adapters shown in (A) correspond to SEQ ID NOS: 7 and 8, respectively.
FIG. 18 . Generation of tobacco transformants on nonselective hormone-free medium. Morphology of regenerated shoots containing T-DNA with an IPT gene (A, B) and without an IPT gene (C).
DETAILED DESCRIPTION OF THE INVENTION
In this invention we describe a process of rapid, inexpensive in planta assembly of a DNA sequence of interest designed for stable integration into a plant chromosome. This approach allows inter alia for fast optimization of the sequences to be expressed by testing various transcription, translation assembled units, units with different protein fusions or different protein targeting or post-translational modification, etc. It can be efficiently used for screening libraries of coding or regulatory sequences of interest. Another application of the invention is the design of safer vectors which are unable to transfer the sequence of interest through an illicit gene transfer. Also, difficult cloning can be avoided during the design of complex DNA regions (e.g. showing instability during cloning procedures in bacterial cells) for stable nuclear transformation, as two or more complex DNA fragments can be linked together in planta prior to integration into plant nuclear DNA.
Current methods of transient or constitutive transgene expression in plants usually employ introducing into plant cell assembled vector(s) with the gene(s) of interest. Transient expression of a sequence of interest is beyond the scope of this invention. The differences between transient and constitutive transgene expression are best exemplified, e.g. within the frame-work of plant functional genomics, where the use of viral vectors can relatively fast provide some initial information about a possible function of a transgene in some cases (WO993651; Kumagai et al., 1995, Proc. Natl. Acad. Sci. USA, 95, 1679-1683). In many other cases, no information or artefacts are obtained. Further, use of viral vectors does not allow further study of the function of a transgene, e.g. during plant development, etc. In addition, Agrobacteria or viral vectors as such cause severe changes in the plant cells, thus making it difficult to study, for example, the functions of genes involved in plant-pathogen interactions. Stably transformed transgenic plants with different expression patterns (e.g. inter- or intracellular compartmentalisation, tissue, organ or cell-specific expression) are required for detailed study of a gene of interest. According to the present invention, the assembly, optimization and identification of a desired DNA sequence of interest for stable nuclear transformation of plant cells can be performed with high efficiency in planta, thus be combined with plant transformation as a one step procedure. In the following, said at least two different vectors of the invention are also referred to as precursor vectors.
The general scheme of such assembly from two or more (precursor) vectors by site-specific DNA recombination is shown in FIG. 1 . The simplest scheme of such assembly is the creation of a DNA sequence of interest ab from two precursors vectors A and B by recombination using the recombination site RS ( FIG. 1A , I). Needless to say that such recombination event shall be selectable. This is easy to achieve e.g. if said recombination creates a functional gene providing for selection.
In one preferred embodiment of the invention, a T-DNA region ( FIG. 7 ) including said DNA sequence of interest is assembled from two precursor vectors represented by two other T-DNA regions ( FIGS. 4 and 6 , bottom) through integrase PhiC31-mediated recombination. Said T-DNA region may contain a functional BAR gene that is absent in the precursor vectors, thus making possible the selection for said recombination event. The integrase necessary for assembly for the T-DNA region of interest may be transiently provided by one of the precursor vectors, pICH11150 ( FIG. 4 ). Because of the irreversibility of the reactions catalyzed by PhiC31 integrase, said integrase can also be constitutively expressed by a genetically engineered plant or plant cell.
Many different site-specific recombinases/integrases that can be used for practicing this invention are known in the art. Suitable recombinases/recombination site systems include inter alia the Cre-Lox system from bacteriophage P1 (Austin et al., 1981, Cell, 25, 729-736), the Flp-Frt system from Saccharomyces cerevisiae (Broach et al., 1982, Cell, 29, 227-234), the R-RS system from Zygosaccharomyces rouxii (Araki et al., 1985, J. Mol. Biol., 182, 191-203), the integrase from the Streptomyces phage PhiC31 (Thorpe & Smith, 1998, Proc. Natl. Acad. Sci., 95, 5505-5510; Groth et al., 2000, Proc. Natl. Acad. Sci., 97, 5995-6000), and resolvases. In addition, other methods of DNA rearrangement are contemplated to be within the scope of the present invention. Other DNA modification enzyme systems can all be used to generate related but functionally distinct DNA sequences of interest inside of a wild-type or a genetically engineered plant cell: restriction endonuclease, transposase, general or specific recombinase, etc. The use of site-specific recombinases with irreversible mode of action is preferred in this invention, as this allows to create a stable recombination product containing said DNA sequence of interest with a predictable structure.
The choice of a suitable promoter to drive expression of the recombinase is of particular value, as it directly affects the performance of the process of the invention, e.g efficiency of assembly of the T-DNA regions and recovery of desired primary transformants in the plant species of choice. The combination of vector pICH15850 carrying a 5′ end of the BAR gene ( FIG. 14 ) with different complementing vectors (e.g. pICH15820, pICH17320, or 17330) produces different results in different plant species. For example, the Arabidopsis actin2 promoter performs better in Arabidopsis than in tobacco, while the promoter of the Arabidopsis gene HSP81.1 gives similarly good results in both plants, Arabidopsis and tobacco.
Different methods may be used for providing a plant cell or a plant with said at least two different vectors (precursor vectors). Said vectors may be transformed into plant cells by a Ti-plasmid vector carried by Agrobacterium (U.S. Pat. No. 5,591,616; U.S. Pat. No. 4,940,838; U.S. Pat. No. 5,464,763) or particle or microprojectile bombardment (U.S. Pat. No. 5,100,792; EP 00444882B1; EP 00434616B1). Other plant transformation methods can also be used like microinjection (WO 09209696; WO 09400583A1; EP 175966B1), electroporation (EP00564595B1; EP00290395B1; WO 08706614A1) or PEG-mediated transformation of protoplasts etc. The choice of precursor vector delivery, like transformation protocols, depends on the plant species to be transformed. For example, microprojectile bombardment is generally preferred for monocot transformation, while for dicots, Agrobacterium -mediated transformation gives better results in general.
In the embodiment described above, we used Agrobacterium -mediated delivery of vector precursors into Nicotiana cells. However, the heterologous DNA may be introduced into the plants in accordance with any of the standard techniques suitable for stable transformation of plant species of interest. Transformation techniques for dicotyledons are well known in the art and include Agrobacterium -based techniques and techniques which do not require Agrobacterium . Non- Agrobacterium techniques involve the uptake of exogenous genetic material directly by protoplasts or cells. These techniques include PEG or electroporation mediated uptake, particle bombardment-mediated delivery and microinjection. Examples of these techniques are described in Paszkowski et al., EMBO J 3:2717-2722 (1984), Potrykus et al., Mol. Gen. Genet. 199:169-177 (1985), Reich et al., Biotechnology 4:1001-1004 (1986), and Klein et al., Nature 327:70-73 (1987). In each case, the transformed cells are regenerated to whole plants using standard techniques.
Agrobacterium -mediated transformation is a preferred technique for the transformation of dicotyledons because of its high transformation efficiency and its broad utility with many different species. The many crop species which may be routinely transformed by Agrobacterium include tobacco, tomato, sunflower, cotton, oilseed rape, potato, soybean, alfalfa and poplar (EP 0 317 511 (cotton), EP 0 249 432 (tomato), WO 87/07299 ( Brassica ), U.S. Pat. No. 4,795,855 (poplar)). Agrobacterium transformation typically involves the transfer of the binary vector carrying the foreign DNA of interest to an appropriate Agrobacterium strain which may depend on the complement of vir genes carried by the host Agrobacterium strain either on a co-resident plasmid or chromosomally (Uknes et al., Plant Cell 5:159-169 (1993). The transfer of the recombinant binary vector to Agrobacterium may be accomplished by a triparental mating procedure using E. coli carrying the recombinant binary vector, a helper E. coli strain which carries a plasmid such as pRK2013, which is able to mobilize the recombinant binary vector to the target Agrobacterium strain. Alternatively, the recombinant binary vector may be transferred to Agrobacterium by DNA transformation (Höfgen & Willmitzer, Nucl. Acids Res. 16, 9877 (1988)).
Transformation of the target plant species by recombinant Agrobacterium usually involves co-cultivation of the Agrobacterium with explants from the plant following protocols known in the art. Transformed tissue carrying an antibiotic or herbicide resistance marker present between the binary plasmid T-DNA borders may be regenerated on selectable medium.
Preferred transformation techniques for monocots include direct gene transfer into protoplasts using PEG or electroporation techniques and particle bombardment into callus tissue.
The patent applications EP 0 292 435, EP 0 392 225 and WO 93/07278 describe techniques for the preparation of callus and protoplasts of maize, transformation of protoplasts using PEG or electroporation, and the regeneration of maize plants from transformed protoplasts. Gordon-Kamm, et al., Plant Cell 2:603-618 (1990), and Fromm, et al., Biotechnology 11:194-200 (1993), describe techniques for the transformation of elite inbred lines of maize by particle bombardment.
Transformation of rice can also be undertaken by direct gene transfer techniques utilizing protoplasts or particle bombardment. Protoplast-mediated transformation has been described for Japonica-types and Indica-types (Zhange, et al., Plant Cell Rep. 7:739-384 (1988); Shimamoto, et al., Nature 338:274-277 (1989); Datta, et al., Biotechnology 8:736-740 (1990)). Both types are also routinely transformable using particle bombardment (Christou, et al., Biotechnology 9:957-962 (1991)). Agrobacterium -mediated rice transformation is also applicable (Chan et al., 1993, Plant Mol. Biol., 22, 491-506).
EP 0 332 581 describes techniques for the generation, transformation and regeneration of Pooideae protoplasts. Furthermore, wheat transformation is described by Vasil, et al., Biotechnology 10:667-674 (1992) using particle bombardment into cells of type C long-term regenerable callus. Vasil, et al., Biotechnology 11:1553-1558 (1993) and Weeks, et al., Plant Physiol. 102:1077-1084 (1993) describe particle bombardment of immature embryos and immature embryo-derived callus.
Transformation of monocot cells such as Zea mays may be achieved by bringing the monocot cells into contact with a multiplicity of needle-like bodies on which these cells may be impaled, causing a rupture in the cell wall thereby allowing entry of transforming DNA into the cells (see U.S. Pat. No. 5,302,523). Transformation techniques applicable to both monocots and dicots are also disclosed in the following U.S. Pat. No. 5,240,855 (particle gun); U.S. Pat. No. 5,204,253 (cold gas shock accelerated microprojectiles); U.S. Pat. No. 5,179,022 (biolistic apparatus); U.S. Pat. Nos. 4,743,548 and 5,114,854 (microinjection); and U.S. Pat. Nos. 5,149,655 and 5,120,657 (accelerated particle mediated transformation); U.S. Pat. No. 5,066,587 (gas driven microprojectile accelerator); U.S. Pat. No. 5,015,580 (particle-mediated transformation of soy bean plants); U.S. Pat. No. 5,013,660 (laser beam-mediated transformation); U.S. Pat. Nos. 4,849,355 and 4,663,292.
Transgenic plant cells or plant tissue transformed by one of the methods described above may then be grown to full plants in accordance with standard techniques. Transgenic seeds can be obtained from transgenic flowering plants in accordance with standard techniques. Likewise, non-flowering plants such as potato and sugar beets can be propagated by a variety of known procedures. See, e.g., Newell et al. Plant Cell Rep. 10:30-34 (1991) (disclosing potato transformation by stem culture).
The assembly of a DNA sequence of interest in planta from precursor vectors can be greatly facilitated by the presence of helper (auxiliary) sequences A′ and B′ ( FIG. 1A , II) which are preferably absent in the assembled DNA sequence of interest AB ( FIG. 1A , II). These helper sequences may end up in recombination products that do not contain said DNA sequence of interest. Such auxiliary sequences can provide genes of interest that are necessary for assembly of the DNA sequence of interest (e.g. recombinases), removal of transformants carrying a precursor vector stably integrated into chromosomal DNA (e.g. using counter-selectable marker genes), transiently provide for gene products necessary for early stages of tissue culture (e.g. genes responsible for biosynthesis of phytohormones), etc.
In one preferred embodiment of the invention, the generation of a DNA sequence of interest for monocotyledonous plants ( FIG. 9 ) from precursor vectors ( FIG. 8 ) is described. Said precursor vectors may contain two types of auxiliary sequences—one may provide for the site-specific integrase PhiC31 and another may provide for isopentenyl transferase (IPT) altering endogenous cytokinins in affected plant cells (Medford et al., 1989, Plant Cell, 1, 403-413). The IPT gene, in an addition to being used as inducer of axillary bud formation, can be used as selectable marker gene causing plant morphological abnormality, once stably integrated into chromosomal DNA (Ebinuma et al., 1997, Proc. Natl. Acad. Sci. USA, 94, 2117-2121). In this embodiment, the IPT gene can be used as counter-selectable marker allowing for identification and removal of the transformed plant tissues containing precursor vector sequences stably integrated into genomic DNA. FIG. 18 shows tobacco regenerants that contain the IPT gene in T-DNA. They are clearly distinct from the regenerants not having the IPT gene. Other examples of counter-selectable markers (CSM) for use in the present invention are the gene coding for conditionally lethal cytosine desaminase (cod A) (Gleave et al., 1999, Plant Mol. Biol., 40, 223-235) or a gene coding for bacterial cytochrome P-450 (O'Keefe et al., 1994, Plant Physiol., 105, 473-482).
In another preferred embodiment, a mixture of more than two different precursor vectors is used for assembling various DNA sequences of interest. Said DNA sequences of interest may be the result of random site-specific recombination events between two sets of precursor vectors (set A n and set B n , FIG. 1B , I). Actually, a set of DNA sequences of interest of the type A n B n may be generated in a plant cell by site-specific recombination of a set of precursor vectors (A 1 , A 2 , . . . , A n ) with a set of precursor vectors (B 1 , B 2 , . . . , B n ), wherein n is the number of precursor vectors of type A or type B. At least three different precursor vectors are needed to endow the cell with at least two different DNA sequences of interest. The number of all possible combinations of DNA sequences of interest that can be assembled from the plurality of precursor vectors A and the plurality of precursor vectors B may be calculated by multiplying the number of precursor vectors of type A times number of precursor vectors of type B.
Examples for nucleic acid sequences represented as part of A or B and joint together by site-specific recombination may be coding sequences or parts thereof or any genetic elements. Herein, such a genetic element (or regulatory element) may be any DNA element that has a distinct genetic function on DNA or RNA level, said function is other than coding for a structural part of a gene. Examples include: transcriptional enhancers, promoters or parts thereof, translational enhancers, recombination sites, transcriptional termination sequences, internal ribosome entry sites (IRESes), restriction sites, autonomously replicating sequences or origins of replications.
In this invention, the recombination product containing said DNA sequence of interest can consist of components of more than two precursor vectors. In FIG. 1B , II, the assembly of such a DNA sequence of interest containing sequence portions from three different precursor vectors A, B and C, is shown. However, for efficient assembly of said DNA sequence of interest, the use of more than one type of recombinase and/or integrases may be required.
The assembly of a DNA sequence of interest for stable integration into a chromosome of a plant cell allows for the selection of plant cells with said DNA sequence of interest integrated into the chromosomal DNA. One possible mechanisms of selection for said DNA sequence of interest is the assembly of a functional selectable marker gene as is described in detail in examples 1-3 and shown in general in FIG. 10 . The use of a counter-selectable marker gene (CSM) in all precursor vectors ( FIGS. 10 and 11 ) allows for easy removal of plant cells carrying precursor vectors stably integrated into chromosomal DNA. In some cases, the assembly of a DNA sequence of interest together with the assembly of a functional gene of interest might be an advantage, e. g. when the gene of interest is toxic for bacterial cells. The selectable marker in such cases can be a part of a bicistronic construct under control of an IRES element ( FIG. 11 ). The site-specific recombination of precursor vectors (A and B in FIG. 11 ) may lead to the formation of DNA sequence of interest carrying the functional bicistronic construct with the gene of interest followed by an IRES-controlled selectable marker gene. The use of IRES elements in plants is known in the prior art (WO9854342; WO0246440; Dorokhov et al., 2002, Proc. Natl. Acad. Sci. USA, 99, 5301-5306) and can be routinely practiced in combination with the present invention.
The assembly of complex vectors in planta from precursor vectors that are of simpler structure can be a further advantage, allowing to avoid complex cloning steps and/or manipulation with unstable DNA structures in bacterial cells. The assembly of the DNA sequence of interest for generating different derivative vectors in allelic position toward each other is shown in FIG. 12 . Said DNA sequence of interest (FIG. 12 ,C) stably integrated into the plant chromosomal DNA can be further exposed to a transposase of choice (Ac or Spm, FIG. 13 ), allowing to remove the targeted sequences (flanked by Ds sequences for Ac or dSpm sequences for Spm). The final derivative vectors B and C ( FIG. 13 ) are allelic in relation to each other and encode different parts of a gene of interest (GOI) that can be assembled through intein-mediated trans-splicing. This approach addresses biosafety issues, e.g. the control of trangene segregation, as the two fragments of the same gene providing for a trait of interest would always segregate to different gametes due to their allelic location. Details on biologically/environmentally safe transgenic plants having fragments of a transgene in allelic relation can be found in WO03/102197.
The transgenic plants or plant cells produced according to the invention may be used for many different purposes, some of which have been mentioned above. In a further application, the DNA sequence of Interest assembled in planta may in turn also be used as a precursor vector for downstream processes. Said DNA sequence of interest may e.g. be induced to form an extrachromosomal DNA like an independently maintained episomal vector. This inducing may e.g. be achieved by crossing a transgenic plant of the invention carrying said DNA sequence of interest with another plant that provides a factor capable of exerting the inducing function or triggering the formation of said extrachromosomal/episomal DNA. Alternatively, the formation of such an episomal DNA can be caused e.g. by transient expression of a factor (e.g. transposase, viral replicase, etc.) capable of triggering formation of the extrachromosomal/episomal DNA from said DNA sequence of interest. Said episomal DNA may be capable of further reintegration (e.g. it may be or have properties of a transposable element) or be capable of independent maintenance during cell divisions (derivative of DNA viral vector).
The present invention is preferably carried out with higher, multi-cellular plants. Preferred plants for the use in this invention include any plant species with preference given to agronomically and horticulturally important species. Common crop plants for the use in present invention include alfalfa, barley, beans, canola, cowpeas, cotton, corn, clover, lotus, lentils, lupine, millet, oats, peas, peanuts, rice, rye, sweet clover, sunflower, sweetpea, soybean, sorghum triticale, yam beans, velvet beans, vetch, wheat, wisteria, and nut plants. The plant species preferred for practicing of this invention are including but not restricted to: Representatives of Gramineae, Compositeae, Solanaceae and Rosaceae.
Additionally, preferred species for use the invention, as well as those specified above, plants from the genera: Arabidopsis, Agrostis, Allium, Antirrhinum, Apium, Arachis, Asparagus, Atropa, Avena, Bambusa, Brassica, Bromus, Browaalia, Camellia, Cannabis, Capsicum, Cicer, Chenopodium, Chichorium, Citrus, Coffea, Coix, Cucumis, Curcubita, Cynodon, Dactylis, Datura, Daucus, Digitalis, Dioscorea, Elaeis, Eleusine, Festuca, Fragaria, Geranium, Glycine, Helianthus, Heterocallis, Hevea, Hordeum, Hyoscyamus, Ipomoea, Lactuca, Lens, Lilium, Linum, Lolium, Lotus, Lycopersicon, Majorana, Malus, Mangifera, Manihot, Medicago, Nemesia, Nicotiana, Onobrychis, Oryza, Panicum, Pelargonium, Pennisetum, Petunia, Pisum, Phaseolus, Phleum, Poa, Prunus, Ranunculus, Raphanus, Ribes, Ricinus, Rubus, Saccharum, Salpiglossis, Secale, Senecio, Setaria, Sinapis, Solanum, Sorghum, Stenotaphrum, Theobroma, Trifolium, Trigonella, Triticum, Vicia, Vigna, Vitis, Zea , and the Olyreae, the Pharoideae and many others.
Within the scope of this invention the plant species, which are not included into the food or feed chain are specifically preferred for pharmaceutical and technical proteins production. Among them, Nicotiana species are the most preferred, as the species easy to transform and cultivate with well developed expression vectors (especially viral vectors) systems.
Genes of interest, their fragments (functional or non-functional) and their artificial derivatives that can be expressed in plants or plants cells using the present invention include, but are not limited to: starch modifying enzymes (starch synthase, starch phosphorylation enzyme, debranching enzyme, starch branching enzyme, starch branching enzyme II, granule bound starch synthase), sucrose phosphate synthase, sucrose phosphorylase, polygalacturonase, polyfructan sucrase, ADP glucose pyrophosphorylase, cyclodextrin glycosyltransferase, fructosyl transferase, glycogen synthase, pectin esterase, aprotinin, avidin, bacterial levansucrase, E. coli gIgA protein, MAPK4 and orthologues, nitrogen assimilation/methabolism enzyme, glutamine synthase, plant osmotin, 2S albumin, thaumatin, site-specific recombinase/integrase (FLP, Cre, R recombinase, Int, SSVI Integrase R, Integrase phiC31, or an active fragment or variant thereof, isopentenyl transferase, Sca M5 (soybean calmodulin), coleopteran type toxin or an insecticidally active fragment, ubiquitin conjugating enzyme (E2) fusion proteins, enzymes that metabolise lipids, amino acids, sugars, nucleic acids and polysaccharides, superoxide dismutase, inactive proenzyme form of a protease, plant protein toxins, traits altering fiber in fiber producing plants, Coleopteran active toxin from Bacillus thuringiensis (Bt2 toxin, insecticidal crystal protein (ICP), CryIC toxin, delta endotoxin, polyopeptide toxin, protoxin etc.), insect specific toxin AaIT, cellulose degrading enzymes, E1 cellulase from Acidothermus celluloticus , lignin modifying enzymes, cinnamoyl alcohol dehydrogenase, trehalose-6-phosphate synthase, enzymes of cytokinin metabolic pathway, HMG-CoA reductase, E. coli inorganic pyrophosphatase, seed storage protein, Erwinia herbicola lycopen synthase, ACC oxidase, pTOM36 encoded protein, phytase, ketohydrolase, acetoacetyl CoA reductase, PHB (polyhydroxybutanoate) synthase, acyl carrier protein, napin, EA9, non-higher plant phytoene synthase, pTOM5 encoded protein, ETR (ethylene receptor), plastidic pyruvate phosphate dikinase, nematode-inducible transmembrane pore protein, trait enhancing photosynthetic or plastid function of the plant cell, stilbene synthase, an enzyme capable of hydroxylating phenols, catechol dioxygenase, catechol 2,3-dioxygenase, chloromuconate cycloisomerase, anthranilate synthase, Brassica AGL15 protein, fructose 1,6-biphosphatase (FBPase), AMV RNA3, PVY replicase, PLRV replicase, potyvirus coat protein, CMV coat protein, TMV coat protein, luteovirus replicase, MDMV messenger RNA, mutant geminiviral replicase, Umbellularia californica C12:0 preferring acyl-ACP thioesterase, plant C10 or C12:0 preferring acyl-ACP thioesterase, C14:0 preferring acyl-ACP thioesterase (luxD), plant synthase factor A, plant synthase factor B, D6-desaturase, protein having an enzymatic activity in the peroxysomal b-oxidation of fatty acids in plant cells, acyl-CoA oxidase, 3-ketoacyl-CoA thiolase, lipase, maize acetyl-CoA-carboxylase, 5-enolpyruvylshikimate-3-phosphate synthase (EPSP), phosphinothricin acetyl transferase (BAR, PAT), CP4 protein, ACC deaminase, protein having posttranslational cleavage site, DHPS gene conferring sulfonamide resistance, bacterial nitrilase, 2,4-D monooxygenase, acetolactate synthase or acetohydroxyacid synthase (ALS, AHAS), polygalacturonase, Taq polymerase, bacterial nitrilase, many other enzymes of bacterial or phage including restriction endonucleases, methylases, DNA and RNA ligases, DNA and RNA polymerases, reverse trascryptases, nucleases (Dnases and RNAses), phosphatases, transferases etc.
The present invention also can be used for the purpose of molecular farming and purification of commercially valuable and pharmaceutically important proteins including industrial enzymes (cellulases, lipases, proteases, phytases etc.) and fibrous proteins (collagen, spider silk protein, etc.). Human or animal health protein may be expressed and purified using described in our invention approach. Examples of such proteins of interest include inter alia immune response proteins (monoclonal antibodies, single chain antibodies, T cell receptors etc.), antigens including those derived from pathogenic microorganisms, colony stimulating factors, relaxins, polypeptide hormones including somatotropin (HGH) and proinsulin, cytokines and their receptors, interferons, growth factors and coagulation factors, enzymatically active lysosomal enzyme, fibrinolytic polypeptides, blood clotting factors, trypsinogen, a1-antitrypsin (AAT), human serum albumin, glucocerebrosidases, native cholera toxin B as well as function-conservative proteins like fusions, mutant versions and synthetic derivatives of the above proteins.
The above proteins and others can optimised for a desired purpose by introducing random mutations into their coding sequence or by gene shuffling methods. Screening for a protein having optimised properties for the desired purpose may then be done using the process of the present invention.
EXAMPLES
The following examples are presented to illustrate the present invention. Modifications and variations may be made without departing from the spirit and scope of the invention.
Example 1
Vector Design for the Stable Transformation of Dicotyledonous Plants with Split BAR Gene
Design of pICH11150
This construct was done on the basis of binary vector pICBV-19 ( FIG. 2 ). As a first step of cloning, the target BsaI restriction sites for the intron insertion were introduced into the BAR gene (construct pICH10605, FIG. 2 ). The BsaI enzyme cuts DNA outside of the recognition site making 4 nucleotides overhang. In the case of pICH10605, the BsaI enzyme was used to introduce splicing acceptor and donor sites for the consequent intron insertion. As a next step, PCR fragment amplified on pICH7410 ( FIG. 3 ) construct with oligos int-ad-9 (5′-tttttggtc cgacctgcaa caataagaac aaaaagtcat aaatt-3′; SEQ ID NO: 1) and attbpr11 (5′-tttaagcttg agctctttcc taggctcgaa gccgcggtgc gggtg-3′; SEQ ID NO: 2) was inserted into pICH10605 using BsaI and HindIII restriction sites. The PCR fragment containing AttB and 3′ part of intron as well as AvrII and SacI restriction sites replaced the GUS expression cassette and 5′part of BAR expression cassette. The T-DNA part of the resulting construct (pICH11140, FIG. 4 ) contained the 3′ part of BAR expression cassette: AttB, 3′part of the intron, 3′ part of BAR-gene and OCS terminator as well as AvrII and SacI restriction sites. As a final step of 3′ construct cloning, a PhiC31 integrase expression cassette containing Arabidopsis actin 2 promoter, PhiC31 integrase and NOS terminator was introduced into pICH11140 using AvrII and SacI restriction sites. The final construct pICH11150, containing 3′ end of BAR gene with AttB, recombination site together with the 3′ end of the intron, as well as PhiC31 integrase expression cassette is shown in FIG. 4 .
Design of pICH11170
This construct was done on the basis of binary vector pICBV-16 ( FIG. 5 ). The PCR fragment amplified from pICH8430 ( FIG. 5 ) with oligos int-ad-10 (5′-tttaagcttg aattcttttg gtctcaggta agtttcattt tcataattac aca-3′; SEQ ID NO: 3) and attppr14 (5′-tttttcaatt ggagctccta cgcccccaac tgagagaac-3′; SEQ ID NO: 4) was cut with HindIII and MfeI restriction enzymes and introduced into pICBV-16 digested with HindIII and EcoRI. PCR fragment containing 5′ part of intron and AttP as well as BsaI and EcoRI restriction sites replaced the GUS expression cassette in intermediate construct pICH11160 ( FIG. 6 ). As the final step of the cloning, EcoRI/BsaI fragment of pICH10605 ( FIG. 2 ) containing a NOS promoter and 5′ part of BAR gene was inserted into pICH11160. The T-DNA region of the final construct pICH11170 is shown in FIG. 6 .
Further vectors for use in the invention are described in the following.
Design of pICH17330
The AvrII/NcoI DNA fragment containing the Arabidopsis Hsp81.1 promoter and fragment of PhiC31 integrase ORF was transferred into the pICH15820 ( FIG. 14 ) construct linearised with AvrII and NcoI enzymes yielding pICH 17330 ( FIG. 15 ).
Design of pICH17320
The Spe/NcoI DNA fragment containing the complete Spm promoter and the fragment of PhiC31 integrase ORF was transferred into pICH15820 ( FIG. 14 ) construct linearised with AvrII and NcoI enzymes yielding pICH17320 ( FIG. 15 ).
Design of pICH15850
The NotI/SacI fragment of pICH11170 ( FIG. 6 ) was fused with adapters adipt1 (5′ ggccgctttt tatgcattt tttgagctct cgcgaggatc ctagct 3′; SEQ ID NO: 5) and adipt2 (5′ aggatcctcg cgagagctca aaaaatgcat aaaaagc 3′; SEQ ID NO: 6) that destroyed the original SacI site and introduced BamHI, SacI and NsiI sites, producing pICH15830 ( FIG. 16 ). For pICH15840 cloning, the NotI/NsiI fragment of pICBV2 ( FIG. 16 ) was transferred to the pICH15830 ( FIG. 16 ) construct, reintroducing T-DNA left border region which was excised in the first step of cloning. The BamHI/SacI fragment of pICH15820 ( FIG. 14 ) containing complete IPT gene was transferred to pICH15840, resulting in pICH15850 ( FIG. 14 ).
Design of pICH15820
The cloning of 3′ split-BAR construct with isopenthenyl transferase (IPT) gene (pICH15820) comprised several steps. In the pICH13630 construct (FIG. 17 ,A), adapter adipt3/adipt4 that destroyed original AvrII and SacI sites and introduced SacI and AvrII sites in reverse orientation replaced AvrII/SacI fragment. In addition, this adapter introduced SpeI and XhoI sites for the insertion of IPT gene (pICH15760, FIG. 17 , A). The AvrII/SacI fragment containing a PhiC31 integrase expression cassette ( Arabidopsis actin 2 promoter-PhiC31 integrase ORF with C-terminal nuclear localization signal-nos terminator) was transferred from pICH10881 to pICH15760 resulting in pICH15770 ( FIG. 17 , B)
Isopenthenyl transferase (IPT) gene (including original promoter and terminator regions) of Agrobacterium strain C58 (appr. 2 kb) was amplified by PCR as 4 fragments flanked by BsaI restriction sites. PCR fragments were subcloned into pGEM-T vectors and then isolated using BsaI enzyme having its recognition site outside of the digestion site. This allows to create 4 bp overhangs with any nucleotide sequence enabled to assemble the entire IPT gene and insert it into the pICH15770 ( FIG. 17 ) contruct linearised with XhoI/SpeI in one ligation step. This cloning resulted in pICH15820 ( FIG. 14 ).
Example 2
Agrobacterium -Mediated Transformation of the Dicotyledonous Plant Nicotiana tabacum (cv Petit Havana) and Arabidopsis thaliana with in planta Assembled T-DNA Region
The constructs pICH11150 and pICH11170 were immobilized into A. tumefaciens (GV3101) and used for Agrobacterium -mediated leaf discs transformation of Nicotiana plants (Horsh et al., 1985, Science, 227, 1229-1231) using 10 mg/L of phosphinothricin (PPT) as selectable marker. Arabidopsis thaliana plants were transformed using a vacuum infiltration protocol (Bechtold et al., 1993, C. R. Acad. Sci. Paris Life Sci. 316, 1194-1199). Phosphinothricine-resistant (PPT R ) transformants were selected by spraying one-week-old plantlets with a 2.5 ml/L of Harvest™ (Agrevo) solution (active ingredient glufosinate, commercially available PPT-analogous compound).
Regenerated tobacco plants and selected A. thaliana primary transformants were PCR analysed for the presence of an in planta assembled T-DNA region stably integrated into chromosomal DNA ( FIG. 7 ) and for the absence of the T-DNA regions of pICH11150 and pICH11170. PCR analysis demonstrated that approximately 8% of all Arabidopsis transformants contained the desired T-DNA region ( FIG. 7 ) without co-integrated T-DNA regions of pICH11150 and pICH11170. The same analysis of tobacco regenerants revealed a significantly lower frequency of plants with desired genotype than observed with Arabidopsis —less than 0.1%. Similar results described above were obtained with the complementing pair of constructs pICH15820 and pICH15850 ( FIG. 14 ). However, there were no primary transformants resulting from co-integration (and restoration of BAR activity by intron formation) of said T-DNA regions, but only from site-specific recombination. This might be explained by the presence of a large region separating the 3′ and 5′ parts of introns of co-integrated T-DNAs. New set of constructs using integrase under control of different promoters (either Zea mays Spm transposase (pICH17320, FIG. 15 ), or Arabidopsis heat shock protein Hsp81.1 (pICH17330, FIG. 15 ) was generated. These vectors in combination with complementary vector pICH15850 ( FIG. 14 ) showed much better results than vector pICH15820 ( FIG. 14 ). For example, the frequency of tobacco transformants carrying correctly recombined T-DNA regions without co-integrated T-DNAs were approx 10% or more depending on experiments. This demonstrates that the efficiency of the process can be affected by controlling the efficiency of integrase expression and can be adjusted to any plant species of interest. The regenerating tobacco phenotypes with and without IPT gene are shown in FIG. 18 .
Example 3
Vector Design and Agrobacterium -Mediated Transformation of Monocotyledonous Plants with Split BAR Gene
For the design of constructs using a split BAR gene to monitor desired T-DNA region assembly in planta, the original constructs pICH11150 and pICH11170 (see EXAMPLE 1) were used. The construct pICH11150 was modified by replacing the Arabidopsis actin2 (PACT2-i,) promoter with rice actin1 (PACT1) promoter (McElroy D, et al., 1991, Mol Gen Genet., 231, 150-160) yielding construct pICH12022 ( FIG. 8 ). The construct pICH11170 was modified by replacing the nopaline synthase promoter (PNOS) driving expression of the BAR gene fragment with the rice actine1 promoter (PACT1) and the NPTII expression cassette with IPT (isopentenyl transferase, Gene Bank Acc. No.: X14410) expression cassette under control of maize ubiquitin gene promoter (PUBQ) (Christensen A H & Quail P H., 1996, Transgenic Res., 5, 213-218) yielding construct pICH12031 ( FIG. 8 ). All manipulations for construct design were performed using standard cloning procedures (Sambrook, Fritsch & Maniatis, 1989, Molecular cloning: A laboratory manual, 2nd ed. Cold Spring Harbor, N.Y.: CSH Laboratory Press).
The line PEN3 of Pennisetum glaucum was used for Agrobacterium -mediated transformation with plasmids pICH12022 and pICH12031. Aliquotes of Agrobacterium tumefaciens AGL1 strain carrying either pICH12022 or pICH12031 were mixed together in equal proportions and used for transformation as described below.
The culture medium included Murashige and Skoog (MS) salts and vitamins: (Reference: Murashige, T. & Skoog, F. A 1962, Physiol. Plant., 15, 473-497) with 2.0 mg/L of 2,4-D, which is 2,4-Dichlorophenoxyacetic acid, 30 g/l sucrose and 0.3% gelrite. Regeneration medium contained a half-strength MS salts and vitamins with 20 g/L maltose, 1 mg/L IAA, 1 mg/L Zeatin and 0.6% gelrite.
Infection medium (IM) contained a half-strength MS salts and vitamins with 2 mg/L 2,4-D, 10 g/L glucose, 60 g/L maltose, 50 mg/L ascorbic acid, 1 g/L MES (2-N-morpholinoethanesulfonic acid) and 40 mg/L Acetosyringone (AS). The pH of the medium was adjusted to 5.2 by 1 N KOH. Cocultivation medium (CM) was same as the IM (excluding ascorbic acid) and was solidified by adding 0.6% gelrite.
Infection medium was filter sterilized, whereas all other media were autoclaved. AS, dissolved in DMSO (400 mg/mL), was added after sterilization.
Agrobacterial cultures (strains AGL1, EHA105, A4 etc.) with the appropriate binary plasmids were grown for 3 days at room temperature on LB2N (LB medium with 2 g/L NaCl and 1.5% agar) plates supplemented with the appropriate antibiotics. Bacteria were scraped from the plates and resuspended in IM in 50-mL falcon tubes. The tubes were fixed horizontally to a shaker platform and shaken at low speed for 4 to 5 h at room temperature. Optical density of the suspension was measured and OD600 was adjusted to 1.0.
Callus pieces were incubated in the Agrobacterial suspension for 3 hours at room temperature and transferred to the gelrite-solidified CM with 60 g/L maltose.
After 3 days of cultivation on CM, the calli were washed five times by half-strength MS medium with 60 g/L sucrose and transferred to the gelrite-solidified CM with 60 g/L sucrose and 5 mg/L phosphinothricin (PPT) and, in some cases, 150 mg/L Timentin. Phosphinothricin-resistant calli developed under selection were plated to the regeneration medium with 5 mg/L PPT.
The regenerating PPT R plant tissues were initially visually tested for the absence of functional IPT gene causing adventitious formation of shoots in hormone-free media (Ooms et al., 1983, Theor. Appl. Genet., 66, 169-172; Smigocki, A C & Owens, L D., 1989, Plant Physiol., 91, 808-811; Smigocki, A C & Owens, L D. 1988, Proc. Natl. Acad. Sci. USA, 85, 5131-5135). Secondary screening for plants carrying in planta assembled T-DNA region ( FIG. 9 ) and for the absence of T-DNA regions from pICH12022 and pICH12031 were carried out by using PCR analysis of PPT R plant tissue for the presence of integrase PhiC31 and IPT gene sequences. | A process of producing transgenic plants or plant cells stably transformed on a chromosome with a DNA sequence of interest capable of expressing a function of interest, said process comprising (a) providing plant cells or plants with at least two different vectors that are adapted to recombine with each other between site-specific recombination sites compatible with a site-specific recombinase that is also provided in order to produce a non-replicating recombination product containing said DNA sequence of interest, (ii) said at least two different vectors are adapted for integrating said DNA sequence of interest into said chromosome, (iii) said DNA sequence of interest contains sequence portions from at least two of said at least two different vectors, said sequence portions being necessary for expressing said function of interest from said DNA sequence of interest; and (b) selecting plants or plant cells expressing said function of interest. | big_patent |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a swash plate type compressor for compressing a refrigerant gas, by rotating a swash plate. More particularly, the present invention relates to an improvement to swash plate compressors by applying a fluorocarbon coating on the swash plate facial surfaces and ends to reduce the frictional wear on the components. The coated swash plate may be made from lower cost alloy materials while maintaining durability and efficiency.
2. Description of the Related Art
Swash plate compressors have been used in automotive air conditioning systems for many years. In a swash plate type compressor, a swash plate rotates about a shaft. A number of pistons are arranged radially about the perimeter of the swash plate and slide within cylinder bores positioned parallel to the shaft. The facial and end surfaces of the swash plate contact pivoting shoes within the pistons. The rotation of the swash plate reciprocates the pistons. The reciprocating swash plate has a relatively high surface area that contacts the piston shoes. In addition to the large contact area, the type of contact also causes a large amount of friction. The rotating swash plate undergoes a shear-type contact with the piston shoes. The shearing force of the contact wears away many types of friction reducing coatings. The interfacial surfaces between the swash plate and pistons are subject to very high load conditions and are susceptible to premature wear before the remainder of the compressor. Protecting these surfaces from wear increases the life of the compressor and also increases the compressor efficiency.
It is known to coat the surface of an aluminum swash plate to reduce wear. Coatings as described in U.S. Pat. No. 5,056,417, issued Oct. 15, 1991, to Kato et al., include 50% by weight of tin and lesser portions of copper, nickel, zinc, lead and indium to form a metal matrix coating. Coatings of this type are electrolytically applied and usually require that the base material have a highly polished surface to provide maximum durability. These electroplated coatings also require that the swash plate be made from aluminum or aluminum alloy materials that contain hard second phase particles. Hard second phase particles mean second phase particles having an average particle diameter of 200 through 100 micrometers (μm) and a hardness greater than 300 on the Vicars hardness scale or, more preferably, having a hardness greater than 600 on the Vicars hardness scale, such as primary silicon. Especially preferred is an aluminum silicon alloy containing about 13 percent to 30 percent by weight of silicon. The high silicon aluminum and tin metal matrix coating gives the coated swash plate increased durability, but at the expense of frictional resistance.
To enhance the frictional properties of the electroplated swash plate, the 5,056,417 patent teaches the use of a solid lubricant such as fluororesin as part of the metal matrix coating. The fluororesin was added to the aqueous solution used in the chemical plating process. While the fluororesin coating provided a swash plate with a lower coefficient of friction, the surface coating layer exhibited a lower hardness than the tin matrix coating alone and was more susceptive to rapid abrasion.
Electroplated metal matrix coatings on aluminum components are acceptable under light loads, they have several disadvantages when used under high friction loads including the need for expensive, high silicon aluminum base materials; high surface finishing for the base material and a complex electroplating process. Adding the fluororesin to the metal matrix improved the coefficient of friction, but at the expense of surface hardness and durability.
It is desirable to provide a coating on a swash plate that is both friction reducing and highly durable. It is also desirable to provide a coating that permits the use of lower cost, low silicon aluminum base material for the swash plate. It is further desirable to provide a swash plate coating that does not require the need to electroplate the surface of the swash plate. These and other advantages of the present inventions will be more fully described below and in the accompanying drawings.
SUMMARY OF THE INVENTION
The present invention is directed to a swash plate type compressor having a cylinder block with cylinder bores disposed parallel to the axis of the cylinder block. A rotary shaft rotatably mounted within the cylinder block carries an aluminum swash plate. The swash plate is fixed to the rotary shaft and has two facial surfaces and an end surface. The facial surfaces have between 0.0005 inches (12.7 μm) to 0.002 inches (50.8 μm) of a heat curable, cross-linked coating comprising a polyfluoro elastomer bonded directly to the aluminum, a lubricious additive and a load bearing additive. A piston reciprocally fitted within the cylinder bore contains shoes which slideably intervene between the piston and the swash plate facial surfaces and reciprocate the pistons by rotation of the swash plate. The coating on the swash plate permits the use of low silicon alloy aluminum without the need of metal plating or high finish polishing.
The present invention is different from prior swash plate designs having fluororesin coatings by bonding and then cross-linking the fluorocarbon directly to the aluminum ahoy. The coating includes lubricious and load bearing additives to enable the polyfluoro elastomer-based coating to simultaneously provide the necessary durability and low coefficient of friction surface. The fluorocarbon coating is applied to the swash plate in a aqueous spray and then cured in an oven at an elevated temperature. The swash plate facial surfaces, together with the end surface, may be simultaneously coated. Additionally, the piston shoe may be coated with the fluorocarbon coating to further increase the low friction properties of the compressor.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded view of a swash plate compressor.
FIGS. 2 and 3 are cross-sectional photomicrographs of coated aluminum swash plates.
FIG. 4 is a comparison of seizure loads for coated and uncoated swash plates.
FIG. 5 is a comparison of seizure loads for swash plates having a PTFE fluorocarbon coating cured to different temperatures and times.
FIG. 6 is a comparison of the friction coefficient for coated and uncoated swash plates.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Illustrated in FIG. 1 is a perspective and exploded view of an automotive swash plate type compressor 10 for propelling refrigerant gas through a cooling circuit. The compressor 10 comprises a two-piece cylinder block 12, 14 which is provided with a plurality of reciprocating pistons 16. For clarity, FIG. 1 depicts only one of such reciprocating piston 16. In practice, each of the pistons 16 reciprocates within cylinder bore 18.
Each piston 16 is in communication with the swash plate 20 which is fixably mounted on an axially extending rotateable shaft 22. The reciprocating motion of each piston 16 within its associated cylinder bore successively siphons, compresses, and discharges refrigerant gas. A pair of pivoting shoes 24 are positioned between each piston 16 and swash plate 20. The shoe 24 transfers the rotational motion of the swash plate 20 to the linear motion of the piston 16. The swash plate 20 has two facial surfaces 26 (only one shown for clarity) which contact the shoes 24.
Rotation of the shaft 22 causes the swash plate 20 to rotate between the cylinder blocks 14, 16. The facial surfaces 26 contact the shoes 24 and are subjected to a shear-type frictional contact with the shoes 24. An end surface 28 may contact the piston 16 if the piston 16 is slightly skewed or bent. End surface 28 and the facial surfaces 26 are coated with a durable coating to prevent ware from the contact with the pistons 16 and the shoes 24. The coating should also have a low coefficient of friction to increase the efficiency of the compressor.
The swash plate 20 is usually made from an aluminum or aluminum alloy material to make it light-weight and strong. Aluminum and aluminum alloys containing hypereutectic silicon, that is more silicon than is required to form a eutectic crystalline structure, are often used. Hypereutectic silicon aluminum alloys provide a high degree of hardness on the Vickers scale. Unfortunately, hypereutectic aluminum is more expensive than non-hypereutectic aluminum materials and are more difficult to machine because of their hardness.
While the coating of the present invention may be used on hypereutectic aluminum, it is primarily intended for use on non-hypereutectic aluminum and aluminum alloys having less than 10% by weight of silicon. It was found that coated swash plates made from non-hypereutectic aluminum performed equal to hypereutectic alloys.
A coating is applied to the swash plate 20 by means of liquid spray. The shaft 22 is masked and the swash plate 20 is sprayed with an unlinked polyfluoro elastomer. The coating comprises a polyfluoro elastomer, a lubricious additive and a load bearing additive. The polyfluoro elastomer is dissolved in either a water base or hydrocarbon solution. The polyfluoro elastomer is selected from a class of materials which will form highly cross-linked long chain polymers. Especially preferred are polyfluoro elastomers of polytetraflouroethylene (PTFE). The PTFE cross linking occurs at an elevated temperature and produces a highly adherent coating with high load bearing and wear resistant properties. The polyfluoro elastomer, lubricious and load supporting additives are generally suspended or dissolved in a liquid to aid in applying the coating onto a surface. Typical solvents and carriers include N-methylpyrrolidone (NMP), naphtha, xylene, dimethylformamide (DMF) or ethyl acetate.
The lubricious additive is selected from a group of materials that provide reduced friction in applications that use little or no off (dry). Such lubricious materials include carbon black, molydisulfide, cesium fluoride, lithium fluoride and mixtures thereof. The load bearing additive is selected from a group of materials that provide high hardness and durability in dry conditions. Such load bearing materials include boron carbide, boron nitride, oxides of aluminum, oxides of magnesium, spinels of aluminum, spinels of magnesium, silicon carbide, silicon nitride, and mixtures thereof.
The lubricious and load bearing additives are generally both solid and constitute the solid portion of the application mixture. The PTFE is generally in a solution or slurry and constitutes the liquid portion of the application mixture. The ratio of liquid to solid portions is generally between 40% to 90% liquid portion to 60% to 10% solid portion. Most preferred is a ratio of 70% liquid portion to 30% solid portion. The ratio of lubricious additive to load bearing additive is generally between 5% to 30% lubricious additive to 5% to 30% load bearing additive. Most preferred is a ratio of 50% lubricious additive to 50% load bearing additive.
Application mixtures of PTFE, lubricious and load bearing additives are commercially available. Of the currently available commercial mixtures, the PTFE-based coating Fluorolon™325, manufactured by Impreglon Inc. is especially preferred.
Swash plate 20 is usually manufactured by a forging process and is made into a "near net shape". The forging operation requires several machining steps before swash plate 20 achieves its final production tolerance. If the swash plate is used uncoated or with a tin coating, it must be machined to a high polish of less than 0.000039 (1 μm). The coating process of the present invention does not require such a high surface finish on the swash plate. Rather, it is preferred that the swash plate 20 have a roughened surface on surfaces 26, 28 to give the coating a mechanism to mechanically attach to the swash plate 20. Preferred roughed surface textures have a roughness of between 0.000039-0.0012 inches (1-30 μm) and give maximum adhesion of the coating. The surface roughening may be formed on the swash plate surfaces by abrasive grit blasting with alumina oxide, electro-discharge machining, honing or rough machining. Chemical roughening (etching) can also be used.
Photomicrographs showing a cross-sectional view of coated swash plates are reproduced in FIGS. 2 and 3. The roughed surfaces 30, 30' are machined to a surface roughness of approximately 0.000079 inches (2 μm). It is possible to achieve this surface roughness by grit blasting the surface of a polished article and therefore possibly eliminating a final machining step in the existing manufacturing process for swash plates. A solution of unlinked polyfluoro elastomer is applied to the roughened surfaces 30, 30'. Solvents in the polyfluoro elastomer coating evaporate and the coating adheres to the surfaces 30, 30'. The coated swash plate 20 is placed within a curing oven at a temperature of 450° F. for approximately ten minutes. The polyfluoro elastomer coating cross links and cures at the elevated temperature to form a coating 32. A coating thickness of approximately 0.0012 inch (30 μm) has been proven effective for use in swash plates having a shoe gap of between 0 to 0.000039 inches (0 to 1 μm). Thicker coatings are possible, but have not proven themselves to be as durable.
The coated swash plate exhibits very smooth facial surfaces 26 and end surface 28. Surface roughness for surfaces 26, 28 of approximately 0.000020 inch (0.5 μm) are possible using the coatings described. Because of these smooth surfaces, the use of the cross-linked polyfluoro elastomer coating may eliminate one or more machining step currently used in the manufacture of swash plates.
FIG. 2 shows a non-hypereutectic aluminum swash plate having approximately 7% by weight of silicon with the polyfluoro elastomer coating of the present invention. FIG. 3 shows a hypereutectic aluminum containing approximately 17% by weight of silicon. The silicon granules 34 are completely covered by the coating 32 and do not materially affect the durability or frictional properties of the swash plate.
Experimental Results
Illustrated in FIG. 4 is a comparison of the seizure loads of swash plates with: no coating; tin, tin/zinc; and Fluorolon™ 325 on 17% silicon A1. The Fluorolon™ coating includes approximately 70% of PTFE, 15% lubricious additive and 15% load bearing additive. The Fluorolon™325 coating is liquid and was sprayed on the swash plate facial and end surfaces. All measurements were taken dry with a 400 lb. per minute loading and a shoe gap between 0 and 0.000039 inches (0 to 1 μm). The Fluorolon™325 coated swash plate made with hypereutectic aluminum sustained seizure loads of over ten times greater than uncoated hypereutectic aluminum swash plates and approximately five times those of hypereutectic aluminum swash plates coated with tin or tin/zinc.
While not wishing to be bound by the following theory, it is believed that bonding the polyfluoro elastomer directly to the roughened aluminum increases the performance of the swash plate over that of adding the fluorocarbon to a polished surface because the bond between the polyfluoro elastomer is both a mechanical and chemical bond. The fluorocarbon alone is insufficient to provide the durability needed for use on a swash plate. Combining the fluorocarbon with metals such and tin or zinc enhances durability but requires polishing the swash plate and thus reduces the mechanical adhesion of the fluorocarbon. By eliminating the need for the metal coatings, the surface of the swash plate may be toughened to provide the mechanical adhesion needed by the polyfluoro elastomer coating. The polyfluoro elastomer coating, together with the lubricous and load bearing additives is sufficiently durable that metal coatings or hypereutectic base materials may not be needed. The load bearing additives do not require the high surface finish metals such as tin and zinc require.
Swash plates coated with the polyfluoro elastomer coating do not exhibit the poor hardness characteristics of prior fluorocarbon resin compositions because of the load bearing additives. Adhesion between the polyfluoro elastomer and aluminum surface is very high because cross-linked polyfluoro elastomer is mechanically bonded to the aluminum surface.
Illustrated in FIG. 5 are the effects of curing times and temperatures on the durability of the coating. Aluminum swash plates containing 17% silicon were coated with 0.0012 inches (80 μm) of Flurolon™325 polyfluoro elastomer and cured at the temperatures and times shown. Both under curing and over curing the polyfluoro elastomer reduces the durability of the coating as measured by the seizure loads. It is believed that the curing temperature and curing time effect the amount of cross-linking and therefore the strength of the mechanical attachment of the polyfluoro elastomer to the base material. All measurements were taken dry at a loading of 400 lb. per minute. Preferred curing times and temperatures for the Flurolon™325 coating were about 10 minutes at 450° F.
Illustrated in FIG. 6 is a comparison of the friction coefficient of coated and uncoated swash plates. The data is also summarized in the following table:
TABLE 1______________________________________Failure Time Coating and Substrate______________________________________26 sec. Uncoated 17% silicon aluminum (SD)19.5 sec. Tin coated 17% silicon aluminum (SD-Sn)No failure Cross-linked Fluorolon ™ 325 on 17% silicon aluminum (SD-325)No failure Cross-linked Fluorolon ™ 325 on 7% silicon aluminum (SSF-325)______________________________________
An uncoated hypereutectic swash plate exhibits a high friction coefficient at approximately 26 seconds into testing. A hypereutectic swash plate with a tin coating exhibits a high friction coefficient at approximately 195 seconds into testing. Hypereutectic and non-hypereutectic swash plates coated with the PTFE polyfluoro elastomer Fluorolon™325 maintain a low friction coefficient throughout sustained testing. Non-hypereutectic aluminum swash plates perform equal to hypereutectic aluminum swash plates with the PTFE polyfluoro elastomer coating and better than hypereutectic aluminum swash plates with a tin coating.
The coating 32 in FIGS. 2 and 3 is approximately 100% PTFE polyfluoro elastomer and has a thickness of approximately 0.0012 inches (30 μm) when the underlying surface 30, 30' has a roughness of 0.000079 inches (2 μm). Thinner coatings 32 may be applied when the roughness of surfaces of 30, 30' is finer, however, this may negatively affect the adhesion of coating 32 to surfaces 30, 30'. Coatings thicker than 0.0012 inches (30 μm) are not preferred because they tend to degrade under high loads and are not as durable.
It is possible to apply a thicker coating to swash plate 20 and then machine off the excess coating using conventional machining tools. This adds an additional step to the manufacturing process and is generally not needed because the coating thickness may be controlled through the application process, and the resulting coating finish is smooth enough for normal automotive swash plates.
It will be obvious to those of skill in the art that various modifications variations may be made to the foregoing invention without departing from the spirit and scope of the following claims. | A swash plate type compressor having a cylinder block with cylinder bores disposed parallel to the axis of the cylinder block. A rotary shaft rotatably mounted within the cylinder block carries an aluminum swash plate. The swash plate is fixed to the rotary shaft and has two facial surfaces and an end surface. The facial surfaces have a coating of between 0.0005 inches to 0.002 inches of a heat curable, cross-linked polyfluoro elastomer bonded directly to the aluminum, a lubricious additive and a load bearing additive. A piston reciprocally fitted within the cylinder bore contains shoes which slideably intervene between the piston and the swash plate facial surfaces and reciprocate the pistons by rotation of the swash plate. The coating on the swash plate permits the use of slow silicon alloy aluminum without the need of metal plating or high finish polishing. | big_patent |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to organic polymers suitable for use in anti-reflective coatings on semiconductor devices, and methods for preparing them. More specifically, the polymers of the present invention can be used to form a layer which prevents the reflection of light from lower layers coated on a semiconductor chip when photolithography processes using short wavelength light sources, such as 248 nM (KrF) and 193 nm (ArF) wavelengths, are employed during the manufacture of 64M, 256M, 1G, 4G and 16G DRAM semiconductor devices. Anti-reflective coatings comprising polymers of the present invention also eliminate the standing wave effect when an ArF beam is used, and reflection/diffraction caused by changes in the thickness of the photoresist layer itself. The present invention also relates to an anti-reflective composition containing these polymers, alone or in combination with other light-absorbing compounds, and the anti-reflective coating formed from these compositions, as well as preparation methods therefor.
2. Description of the Prior Art
In photolithography processes for forming submicro-patterns during the manufacture of semiconductors, it is unavoidable to have reflective notching of the standing wave of the exposing radiation. This effect is due to the spectroscopic properties of the lower layers coated on the semiconductor wafer, changes in the photoresist layer and variations in the critical dimension (CD) due to diffracted and reflected light from the lower layer. Therefore, it has been suggested that a layer, called an anti-reflective coating, be introduced into the semiconductor device to prevent the reflection of light from the lower layers. This anti-reflective coating usually comprises an organic material that absorbs light in the wavelength range of the light beam source used in the lithography process.
Anti-reflective coatings are categorized into inorganic and organic anti-reflective coatings depending on the coating materials used, or into light-absorbing and light-interfering coatings depending on the mechanism.
An inorganic anti-reflective coating is used mainly in the process of submicro-pattern formation using i-line radiation with a wavelength of 365 nm. TiN and amorphous carbon have been widely used in light-absorbing coatings, and SiON has been used in light-interfering coatings.
Inorganic SiON has been used for anti-reflective coatings in submicro-pattern formation processes using a KrF beam,. A recent trend has been to try to use organic compounds in an anti-reflective coating. Based on knowledge to date, the following are prerequisites for an adequate organic anti-reflective coating:
First, during the pattern formation process, the photoresist must not be peeled from the substrate by dissolving in the solvent used in the organic anti-reflective coating. For this reason, the organic anti-reflective coating needs to be designed to form a cross-linked structure, and must not produce chemicals as a by-product.
Second, acid or amine compounds must not migrate in or out of the anti-reflective coating. This is because there is a tendency for “undercutting” at the lower side of the pattern if an acid migrates, and for “footing” if a base such as an amine migrates.
Third, the anti-reflective coating must have a faster etching speed compared to the photoresist layer so that the etching process can be performed efficiently by utilizing the photoresist layer as a mask.
Fourth, the anti-reflective coating must function with a minimal thickness.
Up to now, suitable anti-reflective coatings have not been developed for use in processes for forming a submicro-pattern using an ArF beam. Furthermore, since there is no known inorganic anti-reflective coating which controls the interference from a 193 nm light source, the use of organic chemicals in anti-reflective coatings is currently being studied.
Therefore, it is desirable to use and develop organic anti-reflective coatings that absorb light strongly at specific wavelengths to prevent the standing wave effect and light reflection in lithography processes, and to eliminate the rear diffraction and reflected light from the lower layers.
SUMMARY OF THE INVENTION
The present invention provides novel chemical compounds suitable for use in anti-reflective coatings in photolithography processes for forming submicro-patterns sing 193 nm (Arf) and 248 nm (KrF) light beams in the manufacture of semiconductor devices.
The present invention further provides preparation methods for chemical compounds to be used in anti-reflective coatings.
The present invention also provides anti-reflective coating compositions containing the above-mentioned compounds and preparation methods thereof.
The present invention also provides anti-reflective coatings formed by using the above-mentioned anti-reflective composition, and methods for the formation thereof.
DETAILED DESCRIPTION OF THE INVENTION
Polymers of the present invention are selected from the group consisting of compounds represented by the following general formulas (1), (2) and (3):
wherein, R is hydrogen, a C 1 -C 6 alkyl group, hydroxy or hydroxymethyl; and m:n is the mole ratio of 0.1-0.9:0.1-0.9;
wherein, R is hydrogen, a C 1 -C 6 alkyl group, hyrdoxy or hydroxymethyl; x is an number between 1 and 5; and a:b:c:d is the mole ratio of 0.1-0.9:0.1-0.9: 0.1-0.9:0.1-0.9; and
wherein,
R 1 is hydrogen, methyl or hydroxy; and e is the average degree of polymerization. Preferably e has a value of 3.0˜17.0.
The polymers of the present invention are designed to facilitate light absorption at wavelengths of 193 nm and 248 nm by having groups that absorbs light strongly at both wavelengths,
The polymers represented by general formula 1 above can be prepared in accordance with the reaction equation 1 set forth below, wherein polyhydroxystyrene resin (Compound I) and diazonaphthoquinone halide (Compound II) are reacted in a solvent in the presence of an amine:
wherein, R is hydrogen, a C 1 -C 6 alkyl group, hydroxy or hydroxymethyl; Y is a halogen group; and m: n is the mole ratio of 0.1-0.9: 0.1-0.9.
The polymer represented by the general formula 2 above can be prepared in accordance with reaction equation 2 set forth below, wherein poly(styrene-acrylate) resin (Compound III) and diazonaphthoquinone halide (Compound II) are reacted in a solvent in the presence of an amine:
wherein, R is hydrogen, a C 1 -C 6 alkyl group, hydroxy or hydroxymethyl; Y is a halogen group; x is an number from 1 to 5; and a:b:c:d is the mole ratio of 0.1-0.9:0.1-0.9:0.1-0.9:0.1-0.9.
The polymer represented by general formula 3 above can be prepared in accordance with reaction equation 3 set forth below, wherein novolac resin (Compound IV) and diazonaphthoquinone halide (Compound II) are reacted in a solvent in the presence of an amine:
wherein, R 1 is hydrogen, methyl or hydroxy; Y is a halogen group; and e is the average degree of polymerization. The raw materials used in the above reactions, polyhydroxystyrene (I), diazonaphthoquinone halide (II), poly(styrene-acrylate) resin (III) and novolac resin (IV), are commercially available or can be synthesized by known methods.
The amine used in preparing the polymers of the present invention is preferably trialkylamine, and more preferably triethylamine.
The solvent used in preparing the polymers of the present invention may be selected from the group consisting of tetrahydrofuran, toluene, benzene, methylethylketone and dioxane.
The reaction temperature of the polymerization process used for preparing the polymers of the present invention is preferably between 50 and 80° C.
The present invention also provides an anti-reflective coating composition containing a polymer of the general formula 1, 2 or 3 alone in an organic solvent.
Anti-reflective coating composition of the present invention may also comprise one of the polymers of general formula 1, 2 or 3 and a light absorbing compound selected from the group consisting of anthracene and its derivatives, fluorenone derivatives, fluorene and its derivatives, fluorenol, xanthone, quinazarin and fluorescein. Examples of such compounds are listed in Tables 1 a and 1b below:
TABLE 1a
anthracene
9-anthracenemethanol
9-anthracenecarbonitrile
9-anthracenecarboxylic acid
dithranol
1,2,10-anthracenetriol
anthraflavic acid
9-anthraldehyde oxime
9-anthraldehyde
2-amino-7-methyl-5-oxo-5H-
1-aminoanthraquinone
anthraquinone-2-carboxylic acid
[1]benzopyranol[2,3-b]
pyridine-3-carbonitrile
1,5-dihydroxyanthraquinone
anthrone
9-anthryltrifluoromethylketone
9-alkyl anthracene derivatives
9-carboxylic anthracene derivatives
1-carboxyl anthracene derivatives
TABLE 1b
fluorenone derivative 1
fluorenone derivative 2
fluorenone derivative 3
fluorenone derivative 4
fluorene
9-fluorene acetic acid
2-fluorene carboxaldehyde
2-fluorene carboxylic acid
1-fluorene carboxylic acid
4-fluorene carboxylic acid
9-fluorene carboxylic acid
9-fluorene methanol
fluorenol
xanthone
quinizarin
fluoresein
In Table 1a above, R 5 , R 6 and R 7 each represent independently hydrogen, a substituted or non-substituted straight or branched C 1 -C 5 alkyl group, cycloalkyl, alkoxyalkyl or cycloalkoxyalkyl, and p is an integer. Preferably P has a value of 1˜3.
In Table 1b above, R 8 -R 15 each represent independently hydrogen, hydroxy, substituted or non-substituted straight or branched C 1 -C 5 alkyl, cycloalkyl, alkoxyalkyl or cycloalkoxyalkyl, and R 16 and R 17 each independently represent an alkyl group.
The anti-reflective coating composition of the present invention is prepared by dissolving a polymer of general formula 1, 2 or 3 above in an organic solvent, and subsequently adding thereto one or more compounds selected from the above Tables 1a and 1b.
The organic solvent used for the preparation can be any suitable conventional organic solvent, preferably a solvent selected from the group consisting of ethyl 3-ethoxypropionate, methyl 3-methoxypropionate, cyclohexanone, propylene glycol and methyletheracetate.
The amount of the solvent used in preparing the anti-reflective coating composition according to the present invention is preferably 200-5000% (w/w) with respect to the weight of the polymer used.
An anti-reflective coating of the present invention can be provided on a semiconductor silicon wafer by filtering a solution of a polymer of general formula 1, 2 or 3 alone, or a composition containing a polymer of general formula 1, 2 or 3 and one or more of the light-absorbing compounds set forth in Tables 1a and 1b, subsequently coating the filtered solution or composition on a wafer that has been prepared in the conventional manner and “hard-baking” the coating (heating the wafer to a temperature of 100-300° C. for 10-1000 seconds) to cross-link the anti-reflective coating polymer.
The polymers comprising the anti-reflective coating of the present invention form a cross-linked structure when they are coated on a wafer and baked at high temperatures (“hard-baked”) through a reaction which opens the ring of the diazonaphthoquinone group in said polymers. This cross-linked structure allows the polymers of the present invention to form an organic anti-reflective coating material which is spectroscopically stable under conventional photolithographic conditions.
The polymers and compositions of the present invention have proven to be excellent organic anti-reflective coating materials during the formation of submicro-patterns in photolithographic processes using 248 nm KrF and 193 nm ArF 1lasers. The anti-reflective effect provided in accordance with the present invention have also been found to be superior when E-beam, extreme ultraviolet (EUV) light, and ion beam light sources are used instead of an ArF beam.
The invention will be further illustrated by the following examples, but the invention is not limited to the examples given.
EXAMPLE 1
Synthesis of Copolymer of Polyhydroxystyrene having a Diazonaphthoquinonesulfonyl Group.
After dissolving completely 49.6 g (0.3 moles) of polyhydroxystyrene resin in a 300 ml round bottomed flask containing 250 g of tetrahydrofuran (THF), 15.2 g (0.15 moles) of triethylamine is added to the mixture and mixed completely. Into the mixture, 45.1 g (0.15 moles) of diazonaphthoquinone chloride is added slowly and reacted for more than 24 hours. After the completion of the reaction, the resin is separated by precipitating it in diethylether and dried under vacuum to obtain a poly(hydroxystyrene-diazonaphthoquinonesulfonylstyrene) copolymer of the present invention wherein 50% of hydroxystyrene monomer is substituted with a diazonaphthoquinonesulfonyl group. The yield is 90-95%.
EXAMPLE 2
Synthesis of Copolymer of Polyhydroxy-methylstyrene having a Diazonaphthoquinonesulfonyl Group.
After dissolving completely 58.8 g (0.33 moles) of poly(hydroxy-(methylstyrene) resin in a 300 ml round bottomed flask containing 250 g of tetrahydrofuran (THF), 13.45 g (0.132 moles) of triethylamine is added to the mixture and mixed completely. Into the mixture, 39.7 g (0.132 moles) of diazonaphthoquinone chloride is added slowly and reacted for more than 24 hours. After the completion of the reaction, the resin is separated by precipitating it in diethylether and dried under vacuum to obtain a poly(hydroxy-methylstyrene-diazonaphthoquinonesulfonyl-(methylstyrene) copolymer of the present invention wherein 40% of the hydroxy-methylstyrene monomer is substituted with a diazonaphthoquinonesulfonyl group. The yield is 90-95%.
EXAMPLE 3
Synthesis of Copolymer of Poly(hydroxystyrene-hydroxyethylacrylate) having a Diazonaphthoquinonesulfonyl Group.
After dissolving completely 84.1 g (0.3 moles) of poly(hydroxystyrene-hydroxyethylacrylate) resin in a 300 ml round bottomed flask containing 300 g of tetrahydrofuran (THF), 15.2 g (0.15 moles) of triethylamine is added to the mixture and mixed completely. Into the mixture, 45.1 g (0.15 moles) of diazonaphthoquinone chloride is added slowly and reacted for more than 24 hours. After the completion of the reaction, the resin is separated by precipitating it in diethylether and dried under vacuum to obtain a poly(hydroxystyrene-hydroxyethylacrylate) copolymer of the present invention wherein 50% of reactant is substituted with a diazonaphthoquinonesulfonyl group. The yield is 85-90%.
EXAMPLE 4
Synthesis of Copolymer of Poly(hydroxystyrene-hydroxyethylmethacrylate) having a Diazonaphthoquinonesulfonyl Group.
After dissolving completely 88.3 g (0.3 moles) of poly(hydroxystyrene-hydroxyethylmethacrylate) resin in a 300 ml round bottomed flask containing 300 g of tetrahydrofuran (THF), 13.7 g (0.135 moles) of triethylamine is added to the mixture and mixed completely. Into the mixture, 40.6 g (0.135 moles) of diazonaphthoquinone chloride is added slowly and reacted for more than 24 hours. After the completion of the reaction, the resin is separated by precipitating it in diethylether and dried under vacuum to obtain a hydroxystyrene-hydroxyethylnethacrylate resin of the present invention wherein 45% of the reactant is substituted with a diazonaphthoquinonesulfonyl group. The yield is 90-95%.
EXAMPLE 5
Synthesis of Phenylnovolac Copolymer having a Diazonaphthoquinonesulfonyl Group.
After dissolving completely 63.1 g (0.35 moles) of phenylnovolac resin in a 300 ml round bottomed flask containing 250 g of tetrahydrofuran (THF), 17.7 g (0.175 moles) of triethylamine is added to the mixture and mixed completely. Into the mixture, 52.6 g (0.175 moles) of diazonaphthoquinone chloride is added slowly and reacted for more than 24 hours. After the completion of the reaction, the resin is separated by precipitating it in diethylether and dried under vacuum to obtain a phenylnovolac resin of the present invention wherein 50% of the reactant is substituted with a diazonaphthoquinonesulfonyl group. The yield is 90-95%.
EXAMPLE 6
Synthesis of Cresolnovolac Copolymer having a Diazonaphthoquinonesulfonyl Group.
After dissolving completely 62.2 g (0.3 moles) of cresolnovolac resin in a 300 ml round bottomed flask containing 250 g of tetrahydrofuran (THF), 15.2 g (0.15 moles) of triethylamine is added to the mixture and mixed completely. Into the mixture, 45.1 g (0.15 moles) of diazonaphthoquinone chloride is added slowly and reacted for more than 24 hours. After the completion of the reaction, the resin is separated by precipitating it in diethylether and dried under vacuum to obtain a cresolnovolac resin of the present invention wherein 50% of the reactant is substituted with a diazo-naphthoquinonesulfonyl group. The yield is 90-95%.
EXAMPLE 7
Preparation of Anti-reflective Coating Film
50 mg of a Copolymer prepared in accordance with Examples 1 through 6 above is mixed with 0.1-30%(w/w) of one of the compounds in Tables 1a and 1b above in about 100 g of propylene glycol methyletheracetate (PGMEA) and the mixture is dissolved completely. The solution is filtered, coated on a wafer and hard-baked at 100-300 ° C. for 10-1000 seconds. Afterwards, a light-sensitive film is coated on this anti-reflective film to provide a semiconductor device suitable for fine pattern formation in a conventional photolithographic process.
The polymers of the present invention have high solubilities in most of the hydrocarbon solvents, but the anti-reflective coating is rendered insoluble in any solvent after hard-baking. Accordingly, the polymers of the present invention are superior for use in a photoresist film and do not exhibit problems such as cutting or footing during the pattern formation.
When the polymers of the present invention are used as anti-reflective coatings in the submicro-pattern formation process of preparing semiconductors, the product yield is increased because the elimination of the CD variation originating from lower layers forms stable 64 M, 256 M, 1G, 4G, 16G DRAM submicro-patterns. | The present invention relates to organic anti-reflective coating polymers and preparation methods therefor. Anti-reflective coatings are used in a semiconductor device during photolithography processes to prevent the reflection of light from lower layers of the device, or resulting from changes in the thickness of the photoresist layer, and to eliminate the standing wave effect when ArF light is used. The present invention also relates to anti-reflective compositions and coatings containing these organic anti-reflective coating polymers, alone or in combination with certain light-absorbing compounds, and preparation methods therefor. When the polymers of the present invention are used in an anti-reflective coating in a photolithography process for forming submicro-patterns, the resultant elimination of changes in CD due to diffractive and reflective lights originating from lower layers increases the product yield in the formation of submicro-patterns during the manufacture of 64 M, 256 M, 1G, 4G and 16G DRAM semiconductor devices. | big_patent |
[0001] The invention relates to a white, flame-retardant, UV-resistant, thermoformable, oriented film made from a crystallizable thermoplastic, the thickness of the film being in the range from 10 to 350 μm. The film comprises at least one white pigment and one flame retardant and one UV absorber and has good orientability and thermoformability, and very good optical and mechanical properties, and can be produced cost-effectively. The invention further relates to the use of this film and to a process for its production.
BACKGROUND OF THE INVENTION
[0002] White, oriented films made from crystallizable thermoplastics with a thickness of from 10 to 350 μm are well known.
[0003] These films do not comprise UV absorbers of any kind as light stabilizers and do not comprise flame retardants of any kind, and therefore neither the films nor the items produced from them are suitable for outdoor applications which demand fire protection or flame retardancy. The films do not pass the fire tests to DIN 4102 Part 2 and Part 1, or the UL 94 test. The films have inadequate thermoformability.
[0004] Even after a short time in outdoor applications, these films yellow and exhibit impairment of mechanical properties due to photooxidative degradation by sunlight.
[0005] EP-A-0 620 245 describes films with improved heat resistance. These films comprise antioxidants which are suitable for scavenging free radicals formed in the film and degrading any peroxide formed. However, that specification gives no proposal as to how the UV resistance of these films might be improved.
[0006] DE-A 2346 787 describes a flame-retardant polymer. Alongside the polymer, the use of the polymer is also claimed for producing films or fibers.
[0007] The following shortcomings were apparent during production of films from this phospholane-modified polymer:
[0008] The polymer is very susceptible to hydrolysis and has to be very thoroughly predried. The polymer cakes during its drying by prior-art dryers, and it is impossible to produce a film except under the most difficult of conditions.
[0009] The films produced under extreme and uneconomic conditions embrittle on exposure to heat, i.e. the mechanical properties are severely impaired due to substantial embrittlement, making the film unusable. This embrittlement occurs after as little as 48 hours of exposure to heat.
[0010] It was an object of the present invention to provide a white, flame-retardant, UV-resistant, thermoformable, oriented film with a thickness of from 10-350 μm which not only can be produced cost-effectively and has good orientability and good mechanical and optical properties, but in particular is flame retardant, does not embrittle on exposure to heat, is thermoformable, and has high UV resistance.
[0011] Flame retardancy means that in a fire test the white film complies with the conditions of DIN 4102 Part 2 and in particular the conditions of DIN 4102 Part 1, and can be allocated to construction materials class B 2 and in particular B 1 for low-flammability materials.
[0012] The film is also intended to pass the UL 94 test “Vertical Burning Test for Flammability of Plastic Material”, permitting its classification in class 94 VTM-0. This means that 10 seconds after removal of the Bunsen burner the film has ceased to burn, and after 30 seconds no glowing is observed, and no drips are found to occur.
[0013] High UV resistance means that sunlight or other UV radiation causes no, or only extremely little, damage to the films, so that the films are suitable for outdoor applications and/or critical indoor applications. In particular, after a number of years in outdoor applications the films are intended not to yellow, nor to exhibit any embrittlement or surface cracking, nor to exhibit any impairment of mechanical properties. High UV resistance therefore means that the film absorbs UV light and does not transmit light until the visible region has been reached.
[0014] Thermoformability means that the film can be thermoformed to give complex and large-surface-area moldings on commercially available thermoforming machinery, without uneconomic predrying.
[0015] Examples of good optical properties include uniform coloration, high surface gloss (>15), low light transmission (<70%), and also a Yellowness Index unchanged from that of the flame-retardant and UV-modified film.
[0016] Good mechanical properties include high modulus of elasticity (E MD >3200 N/mm 2 : E TD >3500 N/mm 2 ), and also good values for tensile stress at break (in MD >100 N/mm 2 ; in TD >130 N/mm 2 ).
[0017] Good orientability includes the capability of the film to give excellent orientation, both in a longitudinal direction and I transverse direction during its production, without break-offs.
[0018] Cost-effective production includes the capability of the raw materials or raw material components needed to produce the flame-retardant film to be dried using industrial-standard dryers. It is important that the raw materials neither cake nor become thermally degraded. These prior-art industrial dryers include vacuum dryers, fluidized-bed dryers, fixed-bed dryers (tower dryers). These dryers operate at temperatures of from 100 to 170° C., at which the flame-retardent polymers cake and have to be dug out, making film production impossible.
[0019] In the case of the vacuum dryer, which provides the mildest drying conditions, the raw material traverses a temperature range from about 30 to 130 ° C., under a vacuum of 50 mbar. Post-drying is then needed in a hopper at temperatures from 100 to 130° C. with a residence time of from 3 to 6 hours. Here, too, this polymer cakes to an extreme extent.
BRIEF DESCRIPTION OF THE INVENTION
[0020] This object is achieved by means of a white thermoformable film with a thickness in the range from 10 to 350 μm, which comprises a crystallizable thermoplastic principal constituent, and comprises at least one white pigment, at least one UV absorber, and at least one flame retardant, where expediently the UV absorber and according to invention the flame retardant are fed directly as masterbatch during the production of the film.
DETAILED DESCRIPTION OF THE INVENTION
[0021] The white, flame-retardant, UV-resistant, thermoformable, oriented film comprises, as principal constituent, a crystallizable thermoplastic. Examples of suitable crystallizable or semicrystalline thermoplastics are polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, preferably polyethylene terephthalate.
[0022] According to the invention, crystallizable thermoplastics are crystallizable homopolymers, crystallizable copolymers, crystallizable compounded materials (mixtures), crystallizable recycled material, and other types of crystallizable thermoplastics.
[0023] The white film may be either a single-layer or a multilayer film. The film may also have a coating of various copolyesters or adhesion promoters.
[0024] According to the invention, the white film comprises a UV absorber and a flame retardant. The UV absorber is expediently fed directly during the production of the film by way of masterbatch technology, the concentration of the UV stabilizer preferably being from 0.01 to 5% by weight, based on the weight of the layer of the crystallizable thermoplastic.
[0025] No embrittlement on brief exposure to heat means that after 100 hours of a heat-conditioning procedure at 100° C. in a circulating-air oven the film or the molding exhibits no embrittlement nor any poor mechanical properties.
[0026] The film of the invention comprises at least one flame retardant, fed directly during the production of the film by way of masterbatch technology, the concentration of the flame retardant being in the range from 0.5 to 30.0% by weight, preferably from 1.0 to 20.0% by weight, based on the weight of the layer of the crystallizable thermoplastic. The ratio of flame retardant to thermoplastic maintained during production of the masterbatch is generally in the range from 60:40% by weight to 10:90% by weight.
[0027] Typical flame retardants include bromine compounds, chloroparaffins, and 10 other chlorine compounds, antimony trioxide, aluminum trihydrates, the halogen compounds being disadvantageous due to the halogen-containing by-products produced. Another extreme disadvantage is the low lighffastness of a film modified therewith, alongside the evolution of hydrogen halides in the event of a fire.
[0028] Examples of suitable flame retardants used according to the invention are organophosphorus compounds, such as carboxyphosphinic acids, anhydrides of these, and dimethyl methylphosphonate. It is important for the invention that the organophosphorus compound is soluble in the thermoplastic, since otherwise the optical properties required are not complied with.
[0029] Since the flame retardants generally have some susceptibility to hydrolysis, it can be advisable to add a hydrolysis stabilizer.
[0030] Hydrolysis stabilizers used are generally phenolic stabilizers, alkali metal/alkaline earth metal stearates, and/or alkali metal/alkaline earth metal carbonates, in amounts of from 0.01 to 1.0% by weight. It is preferable to use amounts of from 0.05 to 0.6% by weight, in particular from 0.15 to 0.3% by weight, of phenolic stabilizers having a molar mass above 500 g/mol. Particularly advantageous compounds are pentaerythrityl tetrakis-3-(3,5-di-tert-butyl-4-hydroxphenyl) propionate or 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene.
[0031] The white pigment is preferably fed by way of masterbatch technology, but may also be incorporated directly at the premises of the polymer producer. The concentration of the white pigment is from 0.2 to 40% by weight, preferably from 0.5 to 25% by weight, based on the weight of the crystallizable thermoplastic.
[0032] Preferred suitable white pigments are titanium dioxide, barium sulfate, calcium carbonate, kaolin, silicon dioxide, preferably titanium dioxide and barium sulfate.
[0033] The titanium dioxide particles may be composed of anatase or rutile, preferably predominantly of rutile, which has higher opacifying power than anatase.
[0034] In a preferred embodiment, the titanium dioxide particles are composed of at least 95% by weight of rutile. They may be prepared by a conventional process, e.g.: by the chloride process or the sulfate process. The amount of these in the base layer is from 0.3 to 25% by weight, based on the base layer, and the average particle size is relatively small, preferably in the range from 0.10 to 0.30 μm.
[0035] Titanium dioxide of the type described does not produce any vacuols within the polymer matrix during the production of the film.
[0036] The titanium dioxide particles may have the type of covering usually used as a covering for TiO 2 white pigment in papers or paints to improve lightfastness, made from inorganic oxides.
[0037] TiO 2 is known to be photoactive. On exposure to UV radiation, free radicals form on the surface of the particles. These free radicals can migrate into the film-forming polymers, causing degradation reactions and yellowing.
[0038] Particularly suitable oxides include the oxides of aluminum, silicon, zinc, or magnesium, and mixtures made from two or more of these compounds. TiO 2 particles with a covering made from two or more of these compounds are described by way of example in EP-A-0 044 515 and EP-A-0 078 633. The coating may also comprise organic compounds having polar and non-polar groups. The organic compounds have to have adequate thermal stability during production of the film by extrusion of the polymer melt. Examples of polar groups are —OH, —OR, —COOX (X═R, H, or Na, R=alkyl having from 1 to 34 carbon atoms). Preferred organic compounds are alkanols and fatty acids having from 8 to 30 carbon atoms in the alkyl group, in particular fatty acids and primary n-alkanols having from 12 to 24 carbon atoms, and also polydiorganosiloxanes and/or polyorganohydrosiloxanes, e.g. polydimethylsiloxane and polymethylhydrosiloxane.
[0039] The coating for the titanium dioxide particles is usually composed of from 1 to 12 g, in particular from 2 to 6 g, of inorganic oxides, and from 0.5 to 3 g, in particular from 0.7 to 1.5 g, of organic compounds, based on 100 g of titanium dioxide particles. The covering is applied to the particles in aqueous suspension. The inorganic oxides may be precipitated from water-soluble compounds, e.g. alkali metal nitrate, in particular sodium nitrate, sodium silicate (waterglass), or silica, in the aqueous suspension.
[0040] For the purposes of the present invention, inorganic oxides, such as Al 2 O 3 or SiO 2 , also include the hydroxides and their various stages of dehydration, e.g. oxide hydrate, the precise composition and structure of which is not known. The oxide hydrates, e.g. of aluminum and/or of silicon, are precipitated onto the calcined and ground TiO 2 pigment, in aqueous suspension, and the pigments are then washed and dried. This precipitation may therefore take place directly in a suspension such as that produced within the production process after calcination followed by wet-grinding. The oxides and/or oxide hydrates of the respective metals are precipitated from the water-soluble metal salts within the known pH range: for example, for aluminum use is made of aluminum sulfate in aqueous solution (pH below 4), and the oxide hydrate is precipitated within the pH range from 5 to 9, preferably from 7 to 8.5, by addition of aqueous ammonia solution or sodium hydroxide solution. If the starting material is waterglass solution or alkali metal aluminate solution, the pH of the initial charge of TiO 2 suspension should be within the strongly alkaline range (pH above 8). The precipitation then takes place within the pH range from 5 to 8, by addition of mineral acid, such as sulfuric acid. Once the metal oxides have been precipitated, the stirring of the suspension continues for from 15 min to about 2 h, aging the precipitated layers. The coated product is separated off from the aqueous dispersion, washed, and dried at an elevated temperature, in particular at from 70 to 100° C.
[0041] Light, in particular the ultraviolet content of solar radiation, i.e. the wavelength region from 280 to 400 nm, induces degradation in thermoplastics, as a result of which their appearance changes due to color change or yellowing, and there is also an adverse effect on mechanical/physical properties.
[0042] Inhibition of this photooxidative degradation is of considerable industrial and economic importance, since otherwise there are drastic limitations on the applications of many thermoplastics.
[0043] Absorption of UV light by polyethylene terephthalates, for example, starts at below 360 nm, increases markedly below 320 nm, and is very pronounced at below 300 nm. Maximum absorption occurs at from 280 to 300 nm.
[0044] In the presence of oxygen it is mainly chain cleavage which occurs, without any crosslinking. The predominant photooxidation products in quantity terms are carbon monoxide, carbon dioxide, and carboxylic acids. Besides the direct photolysis of the ester groups, consideration has to be given to oxidation reactions which likewise form carbon dioxide, via peroxide radicals.
[0045] In the photooxidation of polyethylene terephthalates there can also be cleavage of hydrogen at the position α to the ester groups, giving hydroperoxides and decomposition products of these, and this may be accompanied by chain cleavage (H. Day, D. M. Wiles: J. Appl. Polym. Sci 16, 1972, p. 203).
[0046] UV stabilizers, i.e. light stabilizers which are UV absorbers, are chemical compounds which can intervene in the physical and chemical processes of light-induced degradation. Carbon black and other pigments can give some protection from light. However, these substances are unsuitable for transparent films, since they cause discoloration or color change. The only compounds suitable for transparent matt films are organic and organometallic compounds which produce no, or only extremely slight, color or color change in the thermoplastic to be stabilized, i.e. those which are soluble in the thermoplastic.
[0047] For the purposes of the present invention, UV stabilizers suitable as light stabilizers are those which absorb at least 70%, preferably 80%, particularly preferably 90%, of the UV light in the wavelength region from 180 to 380 nm, preferably 280 to 350 nm. These are particularly suitable if they are thermally stable in the temperature range from 260 to 300° C., i.e. neither decompose nor give rise to release of gases. Examples of UV stabilizers suitable as light stabilizers are 2-hydroxybenzophenones, 2-hydroxybenzotriazoles, organonickel compounds, salicylic esters, cinnamic ester derivatives, resorcinol monobenzoates, oxanilides, hydroxybenzoic esters, and sterically hindered amines and triazines, preference being given to the 2-hydroxybenzotriazoles and the triazines.
[0048] The UV stabilizer(s) are preferably present in the outer layer(s). The core layer may also have UV stabilizer, if required.
[0049] It was highly surprising that the use of the abovementioned UV stabilizers in films gave the desired result. The skilled worker would probably first have attempted to achieve a certain degree of UV resistance by way of an antioxidant, but would have found that the film rapidly yellows on weathering.
[0050] In the knowledge that UV stabilizers absorb UV light and therefore provide protection, the skilled worker would be likely to have used commercially available stabilizers. He would then have observed that
[0051] the UV stabilizer has unsatisfactory thermal stability, and at temperatures of from 200 to 240° C. decomposes and gives rise to release of gases, and
[0052] large amounts (from about 10 to 15% by weight) of the UV stabilizer have to be incorporated in order to absorb the UV light and thus prevent damage to the film.
[0053] At these high concentrations it would have been observed that the film is yellow even just after it has been produced, with Yellowness Indices (YI) of around 25. It would also have been observed that the mechanical properties of the film have been adversely affected. Orientation would have produced exceptional problems, such as
[0054] break-offs due to unsatisfactory strength, i.e. excessively low modulus of elasticity;
[0055] die deposits, causing profile variations;
[0056] roller deposits from the UV stabilizer, causing impairment of optical properties (defective adhesion, non-uniform surface);
[0057] deposits in stretching frames or heat-setting frames, dropping onto the film.
[0058] It was therefore more than surprising that even low concentrations of the UV stabilizer achieve excellent UV protection. It was very surprising that, together with this excellent UV protection,
[0059] within the accuracy of measurement, the Yellowness Index of the film is unchanged from that of an unstabilized film;
[0060] there are no releases of gases, no die deposits, and no frame condensation, and the film therefore has excellent optical properties and excellent profile and layflat, and
[0061] the UV-resistant film has excellent stretchability, and can therefore be produced in a reliable and stable manner on high-speed film lines at speeds of up to 420 m/min.
[0062] It was more than surprising that the use of masterbatch technology and of appropriate predrying and/or precrystallization and, where appropriate, use of small amounts of a hydrolysis stabilizer permit the production of a flame-retardant and thermoformable film with the property profile demanded in a cost-effective manner and without caking in the dryer, and that the film does not embrittle on exposure to heat and does not fracture when creased. It was very surprising that together with this excellent result and the required flame retardancy, and the thermoformability and high UV resistance
[0063] within the accuracy of measurement, the Yellowness Index of the film is not adversely affected when compared with that of an unstabilized film;
[0064] there are no releases of gases, no die deposits, and no frame condensation, and the film therefore has excellent optical properties and excellent profile and layflat, and
[0065] the flame-retardant UV-resistant film has excellent stretchability, and can therefore be produced in a reliable and stable manner on high-speed film lines at speeds of up to 420 m/min.
[0066] With this, the film is also cost-effective.
[0067] It was also surprising that a higher diethylene glycol content and/or polyethylene glycol content and/or IPA content than that of standard thermoplastics permits cost-effective thermoforming of the films on commercially available thermoforming plants, and gives the films capability for excellent reproduction of detail.
[0068] It is moreover very surprising that it is also possible to reuse the regrind produced from the films or from the moldings without adversely affecting the Yellowness Index of the film.
[0069] In one preferred embodiment, the white, flame-retardant film of the invention comprises, as principal constituent, a crystallizable polyethylene terephthalate having a diethylene glycol content of ≧1.0% by weight, preferably ≧1.2% by weight, in particular ≧1.3% by weight, and/or a polyethylene glycol content (PEG content) of ≧1.0% by weight, preferably ≧1.2% by weight, in particular ≧1.3% by weight, from 1 to 20% by weight of an organic phosphorus compound (dimethyl methylphosphonate) as flame retardant soluble in the polyethylene terephthalate, from 0.01 to 5.0% by weight of a UV absorber selected from the group of the 2-hydroxybenzotriazoles or the triazines and soluble in the PET, and from 0.5 to 25% by weight of titanium dioxide whose preferred particle diameter is from 0.10 to 0.50 μm, preferably a rutile-type titanium dioxide. Instead of titanium dioxide, it is also possible to use barium sulfate whose particle diameter is from 0.20 to 1.20 μm as white pigment, the concentration being from 1.0 to 25% by weight. In one preferred embodiment, it is also possible to use a mixture of these white pigments, or a mixture of one of these white pigments with another white pigment.
[0070] In one particularly preferred embodiment, the film of the invention comprises from 0.01 to 5.0% by weight of 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-(hexyl) oxyphenol of the formula
[0071] or from 0.01 to 5.0% by weight of 2,2′-methylenebis(6-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethyl-butyl)phenol of the formula
[0072] In one preferred embodiment, it is also possible to use a mixture of these two UV stabilizers, or a mixture of at least one of these two UV stabilizers with other UV stabilizers, the total concentration of light stabilizer preferably being from 0.01 to 5.0% by weight, based on the weight of crystallizable polyethylene terephthalate.
[0073] In the invention it is important for thermoformability that the crystallizable thermoplastic has a diethylene glycol content (DEG content) of ≧1.0% by weight, preferably ≧1.2% by weight, in particular ≧1.3% by weight, and/or a polyethylene glycol content (PEG content) of ≧1.0% by weight, preferably ≧1.2% by weight, in particular ≧1.3% by weight, and/or an isophthalic acid content (IPA) of from 3 to 10% by weight.
[0074] The white, UV-resistant, thermoformable, flame-retardant film has the following property profile:
[0075] surface gloss, measured to DIN 67530 (measurement angle 20°), is greater than 15, preferably greater than 20, and light transmittance L, measured to ASTM D 1003, is less than 70%, preferably less than 60%, measured to ASTM S 1003, this being surprisingly good for the UV resistance achieved in combination with the flame retardancy.
[0076] Standard viscosity SV (DCA) of the polyethylene terephthalate, measured in dichloroacetic acid to DIN 53728 is from 600 to 1000, preferably from 700 to 900.
[0077] The white polyethylene terephthalate film which comprises at least one organic white pigment, one UV stabilizer, and one flame retardant may be either a single-layer film or a multilayer film.
[0078] In the multilayer embodiment, the film is built up from at least one corner layer and from at least one outer layer, preference being given in particular to a three-layer A-B-A or A-B-C structure.
[0079] For this embodiment it is important that standard viscosity and DEG content and/or PEG content of the polyethylene terephthalate of the core layer are similarto those of the polyethylene terephthalate of the outer layer(s) adjacent to the core layer.
[0080] In a particular embodiment, the outer layers may also be composed of a polyethylene naphthalate homopolymer or of a polyethylene terephthalate-polyethylene naphthalate copolymer, or of a compounded material.
[0081] Again in this embodiment, standard viscosity and DEG content and/or PEG content of the thermoplastics of the outer layers are similar to those of the polyethylene terephthalate of the core layer.
[0082] In the multilayer embodiment, the UV absorber is preferably present in the outer layers. If required, UV absorber may also have been provided in the core layer.
[0083] In the multilayer embodiment, the white pigment and the flame retardant are preferably present in the core layer. However, if required, white pigment and/or flame retardant may also have been provided in the outer layers.
[0084] In another embodiment it is also possible for white pigment, flame retardant and UV absorber to be present in the outer layers. If required and if fire protection requirements are stringent, the core layer may also have what is known as a “base level” of flame retardant.
[0085] Unlike in the single-layer embodiment, the concentration of the white pigment here, and of the flame retardant and of the UV stabilizer, is based on the weight in the modified layer. Highly surprisingly, weathering tests to the ISO 4892 test specification using the Atlas C165 Weather Ometer have shown that in order to achieve improved UV resistance for a three-layer film it is fully sufficient for the outer layers of thickness of from 0.5 to 2 μm to be provided with UV stabilizers. Fire tests to DIN 4102 Part 1 and Part 2, and also the UL 94 test have equally surprisingly shown that compliance of the film of the invention with the requirements extends to the range of thickness from 5 to 300 μm.
[0086] The flame-retardant, UV-resistant, thermoformable, multilayer films produced using known coextrusion technology are therefore of great economic interest when compared with monofilms provided with UV stabilizers and flame retardants throughout, since markedly less additives are needed for comparable flame retardancy and UV resistance.
[0087] At least one side of the film may also have been provided with a scratch-resistant coating, with a copolyester, or with an adhesion promoter.
[0088] Weathering tests have shown that even after from 5 to 7 years of outdoor use (extrapolated from the weathering tests) the flame-retardant UV-resistant films of the invention generally exhibit no increased yellowing, no embrittlement, no loss of surface gloss, no surface cracking, and no impairment of mechanical properties.
[0089] The results of measurements indicate that the film of the invention or the molding does not embrittle when exposed to heat at 100° C. over a prolonged period. This result is attributable to the synergistic action of appropriate precrystallization, predrying, masterbatch technology, and modification with UV stabilizer.
[0090] The film can be thermoformed without predrying, and can therefore be used to produce complex moldings.
[0091] The thermoforming process generally encompasses the steps of predrying, heating, molding, cooling, demolding, and heat-conditioning. Surprisingly, during the thermoforming process it was found that the films of the invention can be thermoformed without prior predrying. This advantage over thermoformable polycarbonate films or thermoformable polymethacrylate films, which require predrying times of from 10 to 15 hours, at temperatures of from 100 to 120° C., depending on thickness, drastically reduces the costs of the forming process.
[0092] The following process parameters for the thermoforming process were found:
Step of process Film of invention Predrying not required Temperature of mold ° C. from 100 to 160 Heating time <5 sec per 10 μm of film thickness Film temperature during from 160 to 220 thermoforming ° C. Possible orientation factor from 1.5 to 2.0 Reproduction of detail good Shrinkage (%) <1.5
[0093] The film of the invention or the molding produced therefrom can moreover be recycled without difficulty and without pollution of the environment, and without loss of mechanical properties, and is therefore suitable for use as short-lived advertising placards, for example, for the construction of exhibition stands, or for other promotional items where fire protection and thermoformability is desired.
[0094] An example of a method for producing the white, flame-retardant, thermoformable, UV-resistant film of the invention is the extrusion process on an extrusion line.
[0095] According to the invention, the flame retardant is added by way of masterbatch technology. The flame retardant is fully dispersed in a carrier material. Carrier materials which may be used are the thermoplastic itself, e.g. the polyethylene terephthalate, or else other polymers compatible with the thermoplastic.
[0096] According to the invention, the UV stabilizer and the white pigment may be fed before the material leaves the producer of the thermoplastic polymer, or during the production of the film, into the extruder.
[0097] DEG content and/or PEG content of the polyethylene terephthalate are set at the premises of the polymer producer during the polycondensation process.
[0098] Addition of the white pigment and of the UV stabilizer by way of masterbatch technology is particularly preferred. The UV stabilizer and, respectively, the white pigment is fully dispersed in a solid carrier material. Carrier materials which may be used are the thermoplastic itself, e.g. the polyethylene terephthalate, or else other polymers sufficiently compatible with the thermoplastic.
[0099] It is important in masterbatch technology that the grain size and the bulk density of the masterbatch are similar to the grain size and the bulk density of the thermoplastic, thus permitting uniform distribution and, with this, uniform UV resistance.
[0100] The polyester films may be produced by known processes from a polyester, where appropriate with other polymers, with the flame retardant, with the white pigment, with the UV absorber, and/or with other conventional additives in conventional amounts from 1.0 to not more than 30% by weight, either in the form of a monofilm or else in the form of multilayer, where appropriate coextruded films with surfaces of identical or different nature, for example pigment being present in one surface but no pigment being present in the other surface. It is also possible for one or both surfaces of the film to be provided with a conventional functional coating by known processes.
[0101] It is important for the invention that the masterbatch which comprises the flame retardant and, where appropriate, the hydrolysis stabilizer, is precrystallized or predried. This predrying includes progressive heating of the masterbatch at subatmospheric pressure (from 20 to 80 mbar, preferablyfrom 30 to 60 mbar, in particular from 40 to 50 mbar), with stirring, and, where appropriate, post-drying at a constant elevated temperature, again at subatmospheric pressure. The masterbatch is preferably charged at room temperature from a feed vessel in the desired blend with the polymers of the base and/or outer layers and, where appropriate, with other raw material components, batchwise in a vacuum dryer which during the course of the drying time or residence time traverses a temperature profile from 10 to 160° C., preferably from 20 to 150° C., in particular from 30 to 130° C. During the residence time of about 6 hours, preferably 5 hours, in particular 4 hours, the raw material mixture is stirred at from 10 to 70 rpm, preferably from 15 to 65 rpm, in particular from 20 to 60 rpm. The resultant precrystallized or predried raw material mixture is post-dried for from 2 to 8 hours, preferably from 3 to 7 hours, in particular from 4 to 6 hours, in a downstream vessel, likewise evacuated, at from 90 to 180° C., preferably from 100 to 170° C., in particular from 110 to 160° C.
[0102] In the preferred extrusion process for producing the polyester film, the molten polyester material is extruded through a slot die and, in the form of a substantially amorphous prefilm, quenched on a chill roll. This film is then reheated and stretched longitudinally and transversely, or transversely and longitudinally, or longitudinally, transversely, and again and longitudinally and/or transversely. The stretching temperatures are generally from T G +10° C. to T G +60° C. (T G =glass transition temperature), and the stretching ratio for longitudinal stretching is usually from 2 to 6, in particular from 3 to 4.5, and that for transverse stretching is from 2 to 5, in particular from 3 to 4.5, and that for any second longitudinal or transverse stretching carried out is from 1.1 to 5. The first longitudinal stretching may, where appropriate, take place simultaneously with transverse stretching (simultaneous stretching). Heat-setting of the film then follows with oven temperatures of from 180 to 260° C., in particular from 220 to 250° C. The film is then cooled and wound.
[0103] The surprising combination of exceptional properties gives the film of the invention excellent suitability for a wide variety of applications, for example for interior decoration, for exhibition stands or exhibition requisites, as displays, for placards, for protective glazing of machinery or of vehicles, in the lighting sector, in the fitting-out of shops or of stores, as a promotional item or laminating medium, for greenhouses, for roofing systems, external cladding, protective coverings, applications in the construction sector, and illuminated advertising profiles, blinds, or electrical applications.
[0104] Its thermoformability makes the film of the invention suitable for thermoforming desired moldings for indoor or outdoor applications.
[0105] The invention is further illustrated below using examples.
[0106] The following standards or methods are used here in measuring the individual properties.
TEST METHODS
[0107] DEG Content, PEG Content and IPA Content
[0108] DEG, PEG, or IPA content is determined by gas chromatography after dissolving the thermoplastic polymer in cresol.
[0109] Surface Gloss
[0110] Surface gloss is measured at a measurement angle of 20° to DIN 67530.
[0111] Light Transmittance
[0112] Light transmittance is the ratio of the total transmitted light to the amount of incident light. Light transmittance is measured using the “®HAZEGARD plus” tester to ASTM D 1003.
[0113] Haze
[0114] Haze is that percentage proportion of transmitted light which deviates by more than 2.50 from the average direction of the incident light beam. Clarity is determined at an angle of less than 2.50.
[0115] Haze is [lacuna] using the “HAZEGARD plus” tester to ASTM D 1003.
[0116] Surface Defects
[0117] Surface defects are determined visually.
[0118] Mechanical Properties
[0119] Modulus of elasticity and tensile stress at break, and tensile strain at break, are measured longitudinally and transversely to ISO 527-1-2.
[0120] SV (DCA), IV (DVA)
[0121] Standard viscosity SV (DCA) is measured by a method based on DIN 53726 in dichloroacetic acid.
[0122] Intrinsic viscosity (IV) is calculated from standard viscosity as follows
IV (DCA)=6.67·10 −4 SV(DCA)+0.118
[0123] Fire Performance
[0124] Fire performance is determined to DIN 4102 Part 2, construction materials class B2, and to DIN 4102 Part 1, construction materials class B1, and also to the UL 94 test.
[0125] Weathering (Bilateral), UV Resistance
[0126] UV resistance is tested as follows to the ISO 4892 test specification:
Tester Atlas Ci 65 Weather Ometer Test conditions Iso 4892, i.e. artificial weathering Irradiation time 1 000 hours (per side) Irradiation 0.5 W/m 2 , 340 nm Temperature 63° C. Relative humidity 50% Xenon lamp internal and external filter made from borosilicate Irradiation cycles 102 minutes of UV light, then 18 minutes of UV light with water spray on the specimens, then again 102 minutes of UV light, etc.
[0127] Yellowness Index
[0128] (YI) is the deviation from the colorless condition in the “yellow” direction and is measured to DIN 6167. Yellowness indices (YIs) <5 are not visually detectable.
[0129] In each case, the examples and comparative examples below use white films of varying thickness, produced on the extrusion line described.
[0130] All of the films were weathered bilaterally to ISO 4892 test specification, in each case for 1000 hours per side using the Atlas Ci 65 Weather Ometer from the company Atlas, and then tested for mechanical properties, Yellowness Index (YI), surface defects, light transmission, and gloss.
[0131] Fire tests to DIN 4102, Part 2 and Part 1, and the UL 94 test, were carried out on all of the films.
EXAMPLES
Example 1
[0132] A white film of 50 m thickness is produced and comprises, as principal constituent, polyethylene terephthalate, 7.0% by weight of titanium dioxide, and 1.0% by weight of the UV stabilizer 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-(hexyl)oxyphenol (®Tinuvin 1577 from the company Ciba-Geigy) and 2.0% by weight of flame retardant.
[0133] The titanium dioxide is of rutile type and has an average particle diameter of 0.20 μm, and has a coating of Al 2 O 3 . ®Tinuvin 1577 has a melting point of 149° C. and is thermally stable up to about 330° C.
[0134] For purposes of uniform distribution, the titanium dioxide and the UV absorber is incorporated into the PET directly at the premises of the polymer producer.
[0135] The flame retardant is the PET soluble organophosphorus compound Amgard P1045 from the company Albright & Wilson.
[0136] The flame retardant is fed in the form of a masterbatch. The masterbatch is composed of 10% by weight of flame retardant and 80% by weight of PET, and its bulk density is 750 kg/m 3 .
[0137] The PET from which the film is produced and the PET that is utilized for masterbatch production have standard viscosity SV (DCA) of 810, corresponding to intrinsic viscosity IV (DCA) of 0.658 dl/g. DEG content and PEG content are 1.6% by weight. 50% of the polyethylene terephthalate, 30% by weight of recycled polyethylene terephthalate material, and 20% by weight of the masterbatch are charged at room temperature from separate feed vessels in a vacuum dryer which from the juncture of charging to the end of the residence time traverses a temperature profile from 25 to 130° C. During the residence time of about 4 hours, the raw material mixture is stirred at 61 rpm.
[0138] The precrystallized or predried raw material mixture is post-dried in the downstream hopper, likewise under vacuum, at 140° C. for 4 hours. The 50 μm monofilm is then produced using the extrusion process described.
[0139] The individual steps of the process were:
Longitudinal Temperature: 85-135° C. stretching Longitudinal stretching ratio: 4.0:1 Transverse Temperature: 85-135° C. stretching Transverse stretching ratio: 4.0:1 Setting Temperature: 230° C.
[0140] The white PET film produced had the following property profile:
Thickness 50 μm Surface gloss side 1 72 (Measurement angle 20°) side 2 68 Light transmittance 28% Surface defects per m 2 none Longitudinal modulus of elasticity 3 700 N/mm 2 Transverse modulus of elasticity 4 800 N/mm 2 Longitudinal tensile stress at break 130 N/mm 2 Transverse tensile stress at break 205 N/mm 2 Yellowness Index (YI) 48 Coloration uniform
[0141] The film fulfills the requirements of construction materials classes B2 and B1 to DIN 4102 Part 2 and Part 1. The film passes the UL 94 test.
[0142] After 200 hours of heat-conditioning at 100 ° C. in a circulating-air drying cabinet the mechanical properties are unaltered. The film exhibits no embrittlement phenomena of any kind.
[0143] After in each case 1000 hours of weathering per side with the Atlas CI 65
[0144] Weather Ometer the PET film has the following properties:
Thickness 50 μm Surface gloss side 1 65 (Measurement angle 20°) side 2 60 Light transmittance 35% Surface defects per m 2 none Longitudinal modulus of elasticity 3 550 N/mm 2 Transverse modulus of elasticity 4 650 N/mm 2 Longitudinal tensile stress at break 118 N/mm 2 Transverse tensile stress at break 190 N/mm 2 Yellowness Index (YI) 49
Example 2
[0145] Coextrusion technology is used to produce a multilayer PET film of thickness 17 μm with the layer sequence A-B-A, B being the core layer and A being the outer layers. The thickness of the core layer is 15 μm and that of each of the two outer layers which cover the core layer is 1 μm.
[0146] The polyethylene terephthalate used for the core layer B is identical with that of example 1 except that it comprises no UV absorber.
[0147] The core layer moreover comprises 2% by weight of flame retardant, the flame retardant being fed in the form of a masterbatch. The masterbatch is composed of 10% by weight of flame retardant and 90% by weight of PET.
[0148] The PET of the outer layers has a standard viscosity SV (DCA) of 810 and has been provided with 1% by weight of Tinuvin 1577 and 0.3% by weight of Sylobloc. The outer layers comprise no titanium dioxide and no flame retardant.
[0149] For the core layer, 50% by weight of polyethylene terephthalate, 30% by weight of recycled polyethylene terephthalate material, and 20% by weight of the masterbatch are precrystallized, predried, and post-dried as in example 1.
[0150] The outer layer polymer does not undergo any particular drying. Coextrusion technology is used to produce a film of thickness 17 μm with the layer sequence A-B-A and with the following properties:
Layer structure A-B-A Total thickness 17 μm Surface gloss side 1 131 (Measurement angle 20°) side 2 126 Light transmittance 49% Surface defects none (specks, orange peel, bubbles, . . . ) Longitudinal modulus of elasticity 3 550 N/mm 2 Transverse modulus of elasticity 4 130 N/mm 2 Longitudinal tensile stress at break 120 N/mm 2 Transverse tensile stress at break 155 N/mm 2 Yellowness Index (YI) 13.3 Coloration uniform
[0151] After 200 hours of heat-conditioning at 100° C. in a circulating-air drying cabinet the mechanical properties are unaltered. The film exhibits no embrittlement phenomena of any kind.
[0152] The film fulfills the requirements of construction materials class B2 and B1 to DIN 4102 Part 2 and Part 1. The film passes the UL 94 test.
[0153] After in each case 1000 hours of weathering per side with the Atlas CI 65 Weather Ometer the PET film has the following properties:
Layer structure A-B-A Total thickness 17 μm Surface gloss side 1 125 (Measurement angle 20°) side 2 116 Light transmittance 45% Surface defects none (specks, orange peel, bubbles, . . . ) Longitudinal modulus of elasticity 3 460 N/mm 2 Transverse modulus of elasticity 4 050 N/mm 2 Longitudinal tensile stress at break 110 N/mm 2 Transverse tensile stress at break 145 N/mm 2 Yellowness Index (YI) 15.1 Coloration uniform
Example 3
[0154] A 20 μm A-B-A film is produced as in example 2, the thickness of the core layer B being 16 μm and that of each of the outer layers A being 2 μm.
[0155] The core layer B comprises only 5% by weight of the flame retardant masterbatch of example 2.
[0156] The outer layers are identical with those of example 2, except that they comprise 20% by weight of the flame retardant masterbatch used in example 2 only for the core layer.
[0157] The raw materials and the masterbatch for the core layer and the outer layers are precrystallized, predried, and postdried as in example 1.
[0158] The multilayer 20 μm film produced by means of coextrusion technology has the following property profile:
Layer structure A-B-A Total thickness 20 μm Surface gloss side 1 136 (Measurement angle 20°) side 2 128 Light transmittance 41% Surface defects none (specks, orange peel, bubbles, . . . ) Longitudinal modulus of elasticity 3 400 N/mm 2 Transverse modulus of elasticity 4 100 N/mm 2 Longitudinal tensile stress at break 120 N/mm 2 Transverse tensile stress at break 160 N/mm 2 Yellowness Index (YI) 13.1
[0159] After 200 hours of heat-conditioning at 100° C. in a circulating-air drying cabinet the mechanical properties are unaltered. The film exhibits no embrittlement phenomena of any kind.
[0160] The film fulfills the requirements of construction materials classes B2 and B1 to DIN 4102 Part 2 and Part 1. The film passes the UL 94 test.
[0161] After in each case 1000 hours of weathering per side with the Atlas CI 65 Weather Ometer the PET film has the following properties:
Layer structure A-B-A Total thickness 20 μm Surface gloss side 1 124 (Measurement angle 20°) side 2 117 Light transmittance 38% Surface defects none (specks, orange peel, bubbles, . . . ) Longitudinal modulus of elasticity 3 350 N/mm 2 Transverse modulus of elasticity 4 000 N/mm 2 Longitudinal tensile stress at break 105 N/mm 2 Transverse tensile stress at break 140 N/mm 2 Yellowness Index (YI) 15.8
[0162] Thermoformability
[0163] The films of examples 1 to 3 can be thermoformed on commercially available thermoforming machinery, e.g. from the company Illig, to give moldings, without predrying. The reproduction of detail in the moldings is excellent, with uniform surface.
Comparative example 1
[0164] Example 2 is repeated. However, the film is not provided with UV absorbers, nor with flame retardant masterbatch. DEG content is the commercially available 0.7%, and no PEG is present.
[0165] The white film produced has the following property profile:
Layer structure A-B-A Total thickness 17 μm Surface gloss side 1 139 (Measurement angle 20°) side 2 130 Light transmittance 50% Surface defects none (specks, orange peel, bubbles, . . . ) Longitudinal modulus of elasticity 4 250 N/mm 2 Transverse modulus of elasticity 4 700 N/mm 2 Longitudinal tensile stress at break 180 N/mm 2 Transverse tensile stress at break 215 N/mm 2 Yellowness Index (YI) 12.0 Coloration uniform
[0166] The unmodified film does not fulfill the requirements of the tests to DIN 4102 Part 1 and Part 2, or of the UL 94 test.
[0167] The film has inadequate thermoformability.
[0168] After 1000 hours of weathering per side using the Atlas CI Weather Ometer the film exhibits embrittlement phenomena and cracking on the surfaces. This makes it impossible to measure the property profile precisely—in particular the mechanical properties. Furthermore, the film has visible yellow coloration. | The invention relates to a white, flame-resistant, UV-stable, thermoformable, oriented film made from a crystallisable thermoplastic, the thickness of which lies in the range of from 10 μm to 350 μm. Said film comprises at least one white pigment, a flame-proofing agent and a UV absorber and is characterized by good stretchability and thermoformability, by good optical and mechanical properties and an economical production. The invention further relates to a method for the production of said film and the use thereof. | big_patent |
FIELD OF THE INVENTION
The present invention relates to an improved method for producing 143a (1,1,1-trifluoroethane) by continuous gas phase hydrofluorination of 1,1-difluoro-1-chloroethane using heterogeneous catalysis.
BACKGROUND OF THE INVENTION
1,1,1-Trifluoroethane (143a) is a hydrofluorocarbon (HFC) with zero ozone depletion potential (ODP). The product was described earlier in the literature as an undesirable co-product from processes involving hydrofluorination of 1,1-dichloroethylene (VDC, 1130a) or 1,1,1-trichloroethane (140a). While methods are known for synthesizing 143a, there is a need for a simple, convenient, economical, industrial process for the manufacturing of 143a. The present invention provides a new practical process for the production of 143a with very high conversion and very high selectivity (both over 99%) for 143a.
In U.S. Pat. No. 3,231,519, issued Jan. 28, 1966 and assigned to Union Carbide Corporation, a catalyst composed of coprecipitated iron hydroxide and rare earth oxide, such as dysprosium hydroxide, and zirconium oxide was used to hydrofluorinate 140a to a mixture of 143a, 142b and 1130a. Thus, when hydrogen fluoride (177 g, 8.85 moles) and 1,1,1-trichloroethane (541 g, 4.05 moles) were vaporized over 150 milliliters of the catalyst over a three to four hour reaction period at a temperature of 230°-260° C., to give 1,1,1-trifluoroethane (122 g, 1.45 moles); 1-chloro-1,1-difluoroethane (33 grams, 0.328 moles); 1,1-dichloroethylene (157 g, 1.62 moles) and a small amount of 1-chloro-1-fluoroethylene. The latter two products, 1130a and 1131a, are a waste co-product; conversion was 83.9% and selectivity for 143a was 42.67% under these conditions. Catalysts claimed in this patent are a combination of iron oxide, rare earth oxide, and zirconium oxide. The lifetime of the catalyst was not reported.
U.S. Pat. No. 3,287,424, issued Nov. 22, 1986 and assigned to Stauffer Chemical Company, discloses the hydrofluorination of 1,1,1-trichloroethane (140a) to 1,1,1-trifluoroethane (143a) in a batch process, using arsenic trifluoride as a fluorinating agent and antimony pentafluoride as a catalyst. In Example 3, a mixture of arsenic trifluoride (333.25 grams, 2.53 moles) and antimony pentafluoride (29.9 grams, 0.14 moles) was reacted with methylchloroform (133 g, 1 mole) at 45°-50° C. to produce 1,1,1-trifluoroethane (63 g, 0.75 moles). The fluorinating agent, AsF 3 , is a highly toxic material and is an expensive reagent for industrial applications.
U.S. Pat. No. 3,803,241, assigned to Dynamit Nobel AG, uses a catalyst composed of chromium (III) chloride supported on alumina, prepared by soaking aluminum oxide pellets in CrCl 3 .6H 2 O solution (31 wt. %). The catalyst was dried at 200° C. using nitrogen or air, followed by HF activation at 250° C. for 2 hours. In Example 1, following the HF activation, a gaseous stream of 1,1-dichloroethylene and hydrogen fluoride in a molar ratio of 1:3.5 at 150° C. was passed over the catalyst bed at 150° C., to yield 98.8 volume % of 1,1,1-trifluoroethane, 0.2 volume % of 142b, 0.2 volume % of 141b and 0.8 volume % of 1,1-dichloroethylene. After running for quite some time (exact running time not reported), the catalyst was regenerated by heating for 10-15 days. No experimental details were provided on how the catalyst was reactivated nor was there evidence that the catalyst performance improved after the treatment. Although the selectivity and conversion were very high, the catalyst required a very long time for regeneration, which is not practical for industrial applications.
In U.S. Pat. No. 3,833,676, it is disclosed that hydrofluorination of methyl chloroform in a liquid phase batch process can produce very low levels of 1,1,1-trifluoroethane (Example 2). In this example, methyl chloroform (3.73 grams) and hydrogen fluoride (17 g) (molar ratio of HF:methyl chloroform=30.3:1) were mixed together in a stainless steel reactor at 110° C. for 2 hours to produce 2.3 mole % of 141b, 95.5 mole % of 142b and 2.1 mole % of 143a. This process is a liquid phase process and requires very long contact time, which means that it is much less productive compared to continuous gas phase processes.
In U.S. Pat. No. 3,836,479, Example 1, a catalyst composed of boric acid (0.18 kg) mixed with pseudoboehmite alumina (1.2 kg) was prepared and activated using hydrogen fluoride at 350° C. using 2 mole/hr HF and 1 mole/hr nitrogen. After the catalyst was activated, a mixture of HF (0.75 mole/hr) and vinylidene fluoride (feed rate not reported) was passed over the catalyst at room temperature to produce 100% conversion to 143a. (Example 12) The feed stock of this process, 1,1-difluoroethylene, is an expensive compound for industrial application, and it is expected that 143a produced using this process will be expensive.
A bismuth containing catalyst supported on alumina was prepared in Example 1 of U.S. Pat. No. 3,904,701 by soaking alpha-alumina (650 g) in a mannitol solution of Bi(NO 3 ) 3 .5H 2 O (153 g). The catalyst was dried at 80° C. for one hour. Subsequently it was activated at 250° C. using a mixture of HF and air. Then a gaseous mixture of 1 part dichloroethylene and 3.2 parts of HF (Example 1) was passed over the catalyst bed at 180° C., with 18 seconds contact time. Analysis of the product obtained indicated that conversion was 99.9%; selectivity for 143a was 99.8% and for 142b it was 0.2%. In all the examples reported in this patent, halogenated alkenes were used as the feed stock. E.g., in Examples 1, 3, 4 and 5; 1,1-dichloroalkene was used as the starting material; in Example 2, vinyl fluoride monomer was used as the organic substrate. The composition of the catalyst of this patent (Bi/Al 2 O 3 ) is totally different from that of the catalyst of the present invention. This patent also discloses an improved regeneration process for the above catalyst, by heating the deactivated catalyst in air at a temperature of about 350°-450° C. This regeneration process is claimed in related U.S. Pat. No. 3,965,038.
A continuous liquid phase process for the hydrofluorination of methylchloroform to the mixture of products 141b, 142b and 143a is disclosed in U.S. Pat. No. 4,091,043. The process requires continuous feed of antimony pentachloride in the presence of organic solvent. This will require additional separation equipment to separate the antimony catalyst and the organic solvent, which is troublesome on the industrial scale. The best result for CH 3 CF 3 selectivity (82.6%) was obtained when the reactor was initially charged with SbCl 5 (52.2 mole %) and 0.76 moles of the solvent 1,1,2-trifluoro-1,2,2-trichloroethane. The feed rate of methylchloroform was 0.76 mole/hour; for HF it was 2.32 mole/hour. At 28° C., conversion was 93%, while selectivity for 143a was 82.6%. Selectivity was 17.1% for 142b and 0.3% for 141b. A similar process was described in Atochem S.A.'s European Patent Publication No. 0 421 830 A1, which uses a combination of SbF 5 and chlorine gas as a catalyst for a HF/methylchloroform process. The percent selectivity of 143a varied between 1% to 10.3%, depending on the processing conditions. Again, this process requires recovery of the antimony catalyst. In the absence of chlorine gas, the active catalytic species, Sb(V), was reduced to the inactive catalyst species, Sb(III).
In U.S. Pat. No. 4,147,733, Example 2, a catalyst composed of alumina coated with 12 percent by weight of Cr 2 O 3 and 6% of NiO, was used to hydrofluorinate chlorinated aliphatic hydrocarbons to the corresponding fluoride using aqueous HF, e.g. at 420° C. Feeding a mixture of 38% aqueous HF and 1,1-dichloroethylene vapors at a 3:1 molar ratio of HF/VDC, gave a total conversion of 16.3% to fluorinated product. The selectivity for 143a was 54.1 mole %, while it was 21% for 1-chloro-1-fluoroethylene and 20.4% for vinylidene fluoride. This process requires the use of aqueous HF as a feed stock, which is known to be very corrosive compared to anhydrous HF gas. Furthermore, the presence of the fluoro-olefin as impurity in 143a is undesirable for either refrigerant applications or foam blowing agent applications.
1,1,1-Trifluoroethane was also reported as a major co-product, during the fluorination of vinylidene fluoride, using activated carbon, in U.S. Pat. No. 4,937,398. The process was directed towards the preparation of 1,1,1,2-tetrafluoroethane. Instead, 143a was the major product. The latter product was suggested to be obtained from a process involving HF addition to vinylidene fluoride. HF was disclosed to be generated by hydrolysis of fluorine gas by the moisture on the surface of activated carbon, e.g., when VF 2 (8 cc/m) mixed with nitrogen (50 cc/m) was slowly fed over activated carbon (40 grams, saturated with 6 wt % of fluorine gas). At 50° C., conversion was 100% and selectivity for 143a was 82%. Selectivity for 1,1,1,2-tetrafluoroethane (134a) was 18%. The implementation of this process for the production of 143a can be a very difficult task, because fluorine gas addition to olefin is a highly exothermic process.
In U.S. Pat. No. 5,008,474, Example 1, hydrofluorination of 1,1-dichloroethylene in the presence of tin tetrachloride as a catalyst, in a batch liquid phase process, produced 143a in small quantities. E.g., when 5.16 moles of 1,1-dichloroethylene, 16.05 moles of HF and 0.25 moles of SnCl 4 , were mixed together under continuous stirring, analysis of the product formed showed the following composition: 143a (2.1 mole %), 142b (26.7%), 141b (64.8%), vinylidene chloride (4.1%), 1,1,1-trichloroethane (0.8%) and oligomeric material (1.4%). In Examples 2-4, the yields of 143a were even lower. Thus, the yield of 143a from this process is not high enough for it to be utilized as an industrial process.
European Patent Publication 0 486 333 A1 (134a) discloses the manufacture of 1,1,1,2-tetrafluoroethane by the vapor phase hydrofluorination of 1-chloro-2,2,2-trifluoroethane (133a) in the presence of a mixed catalyst composed of oxides, halides and/or oxyhalides of chromium and nickel on a support of aluminum fluoride or a mixture of aluminum fluoride and alumina. In (comparative) Example 3, it is taught that the presence of nickel, together with chromium, in the catalyst, enhances both the activity and stability of the catalyst.
International Patent Publication W093/25507 is directed, more broadly, to the vapor phase hydrofluorination of a halocarbon (having at least one halogen other than fluorine) with anhydrous HF, at a temperature above 200° C., in the presence of a catalyst comprising a chromium compound and at least one transition metal compound selected from the oxides, halides and oxyhalides of nickel, palladium and platinum. The catalyst may be unsupported, supported or mixed with an appropriate bonder. Suitable supports are taught to include aluminum oxide, aluminum fluoride, aluminum oxyfluoride, aluminum hydroxyfluoride and carbon. This publication also teaches the importance of the presence of nickel in the catalyst, together with chromium, in order to obtain high rates of conversion and prolonged catalyst activity. 1,1-difluoro-1-chloroethane (142b), the starting material of the process of the present invention, while within the generic disclosure of this publication, is not expressly mentioned therein.
The prior art also describes processes that produce 143a which are based on hydrofluorinating either 140a or 1130a. The first compound (140a) is expected to be regulated by the U.S. federal government in the near future. The second compound (1130a) is known to undergo cationic polymerization to produce low molecular weight polymer and thereby deactivate the catalyst. (See McBeth et al., J. Chem. Soc., Dalton Trans., (1990) 671.) In many cases, it is believed that, if an inhibitor is added to the feed stream, it is likely to poison the catalyst. There is need for a simple, convenient and economical process for the production of 143a that avoids the foregoing problems.
SUMMARY OF THE INVENTION
This invention provides a novel process for manufacturing 143a in an economical, industrially feasible manner, which is based on continuous gas phase hydrofluorination using heterogeneous catalysis. The organic feed is 1,1-difluoro-1-chloroethane (142b) and the fluorinating agent is HF. More particularly, we have discovered that 143a can be produced very efficiently, with conversion rates and selectively each in excess of 99%, while avoiding the formation of olefinic byproducts, by vapor phase fluorination of 142b at a molar ratio of HF:142b in excess of 1:1, and preferably in excess of 2.5:1 in the presence of a Cr catalyst, which may be unsupported or supported, in the absence or presence of a cocatalyst selected from nickel, cobalt and manganese salts. That these exceptional high yields and selectivity for 143a could have been achieved by the hydrofluorination of 142b, particularly when using a chromium catalyst, even when unsupported and without a cocatalyst, was not predictable from the references discussed above. In the absence of catalyst, treating 142b with HF at 140° C., using a molar ratio of HF/142b of 3 and 47 seconds of contact time, gave zero % conversion. In the presence of catalyst, conversion was very high. While the catalyst can be any (supported or unsupported) chromium salt, the two catalysts that we have used to provide high conversion rates in this process are CrF 3 .4H 2 O (powder or pelletized), and Cr/Ni/AlF 3 . Using these catalysts, conversion was very high (over 99%) and selectivity for 143a was also very high (over 99%).
These catalysts were subjected to severe testing, such as high temperature (100°-325° C.), the presence of a high concentration of HCl (32% in the total feed stream) as well as 141b and 1,1,1,3,3-pentafluorobutane (365). Change in % conversion was minimum and selectivity for 143a was still >99.9%. These results are unexpected because it is known that 142b can be dehydrohalogenated to 1,1-difluoroethylene (1132a) and 1-chloro-1-fluoroethylene (1131a). E.g., when 142b was passed over an AlF 3 /Al 2 O 3 bed at 300° C., conversion for 1132a was 10.4% and 79.5% for 1131a. (Walker and Paylath, "Dehydrohalogenation of 1,1,1-Trihaloethanes," J. Org. Chem. (30), 1965 (3284).) On the other hand, 143a can be dehydrofluorinated to 1132a at 500° C. with a 32% conversion rate. (See European Patent Publication No. 0 234 002 B1.)
In this investigation, under isothermal conditions, provided that the molar ratio of HF:142b was greater than 1:1, we have not detected any level of olefinic product at a reaction temperature below 275° C. when the above molar ratio was up to 2.5:1, or at a reaction temperature below 325° C. when that molar ratio was greater than 2.5:1.
Also, whereas the process of WO93/25507 requires a reaction temperature of greater than 200° C., in the process of the present invention, excellent yield and selectivity are obtained at reaction temperatures as low as 100° C.
In another embodiment, the process may be run under adiabatic conditions, e.g. in a continuous, plug flow adiabatic reactor.
BRIEF DESCRIPTION OF THE FIGURERS
FIG. 1 is a schematic diagram of a reactor suitable for carrying out the process of the invention; and
FIG. 2 is a schematic diagram of a pilot version of an adiabatic reactor used for conducting the experiments of Examples 21-26.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates a presently preferred reactor for carrying out the process of the present invention for preparing 143a by hydrofluorinating 142b. This reactor will be described in greater detail below in connection with Example 1.
In the process of this invention, 142b and HF are passed through the catalyst bed in a reactor at the specified conditions for reacting, and then the 143a product is purified. Byproduct HCl and unreacted HF may be removed by any number of methods known to the art, such as absorption in water or caustic solution or on solid absorbants, distillation, or membrane separation. Any unreacted 142b or byproduct 141b or olefins (1,1-difluoroethylene, 1,1-chlorofluoroethylene, 1,1-dichloroethylene) can also be removed, e.g., by distillation, absorption in either liquids or solids, or membrane separation.
Any olefins produced in the first reactor can be reacted with HF in a second reactor operating at a lower temperature than the first reactor (Example 19). The thermodynamic equilibrium between olefins and saturated compounds strongly favors saturated compounds at lower temperatures. This configuration makes it possible to use a lower HF:142b molar ratio, such that olefins are produced in the first reactor and converted in the second reactor. This would minimize the amount of unreacted HF that would have to be neutralized or recycled. Unreacted HF can be separated and recycled to the first reactor.
FIG. 2 illustrates a pilot adiabatic reactor suitable for carrying out the process adiabatically, as in Examples 21-26 below. This reactor will be described in greater detail below in connection with those examples.
The feed source can be pure 142b and HF or other streams containing these two compounds. 142b can be made by the reaction of HF with either 140a or 1130a. The product of this reaction will usually contain unreacted HF and HCl, as well as 141b byproducts. The use of unpurified feed streams containing 141b and HCl is illustrated in Examples 2, 3, 4, 5, 6, 10, and 11 below.
The reactor can be any vessel that allows the contact of the reactants with the catalyst for sufficient time to achieve the desired conversion. Materials of construction should be able to withstand HF and HCl at reaction temperatures, which are known to those skilled in the art. A plug flow reactor is preferred over a mixed reactor, such as a fluidized bed, in order to achieve high conversion in an efficient manner. The reactor can be cooled or not cooled, as long as the proper reaction conditions are maintained.
The catalyst can be any chromium salt, supported or unsupported. In addition, salts of other metals, such as nickel, cobalt, manganese and zinc can be used as supported or unsupported co-catalysts. Presently preferred supports are Al 2 O 3 and fluorided Al 2 O 3 . Other supports that may be used include activated carbon as well as other catalyst supports known in the art. We presently prefer to use unsupported CrF 3 .4H 2 O or supported Cr/Ni/AlF 3 , as indicated in the following examples.
As noted above, the process can be carried out using 142b as a feed and 1,1-dichloro-1-fluoroethane (141b), 1,1,1,3,3-pentafluorobutane (365) or HCl as a co-feed. The process can be carried out at a temperature between 30° C. and 400° C., preferably between 30° and 280° C., more preferably between 100° and 250° C., more preferably between 120° C. and 200° C. In another preferred embodiment, the reaction temperature is between 280° and 350° C. Contact time can be varied from 1-100 seconds and is preferably between 5 and 15 seconds. The catalyst has to be activated first using nitrogen, air or HF/142b at a temperature between 100° C. and 650° C., preferably between 200° C. and 500° C. Hydrofluorination can be performed at a pressure between 1 atmosphere (0 psig) and 200 psig, preferably between 1 atmosphere and 150 psig. The molar ratio of HF:142b can vary between greater than 1:1 and 20:1, preferably between greater than 1:1 and 10:1. More preferably, it is between 2:1 and 5:1.
An important aspect of the invention is the ratio of HF to R142b in the feed. Ideally, this would be very close to 1 to minimize the need for downstream separation. However, at low HF ratios, non-selectives (unwanted by-products) are formed. In particular, three different unwanted olefins can form: vinylidene fluoride (1132a), vinylidene chlorofluoride (1131a), and vinylidene chloride (1130a). These are decomposition products of 142b. These unsaturated compounds are undesirable in the final product even in small quantities. Therefore, they must be either destroyed or removed from the reaction product by a separation method after the reaction is completed and the product is removed from the reactor. These olefins are believed to be precursors to coke formation, which is the major cause of catalyst deactivation. Thus, in order to avoid olefin formation, we have found that the HF/142b molar ratio should be greater than 1:1. There is no upper limit on the HF/142b ratio, although ratios above 10:1 would be economically impractical, both with respect to reactor productivity and separation requirements.
The HF/142b ratio needed to avoid olefin formation is also affected by the reaction temperature. In general, higher ratios are required at higher reaction temperatures in order to avoid olefin formation. We have found that ratios of HF/142b of greater than 1:1 are suitable for reaction temperatures up to 280° C. At reaction temperatures above 280° C., we prefer to use a minimum HF/142b ratio of 2.5:1.
The reactor effluent will contain 143a, HCl, and HF. In the process of the invention, conversion is generally in excess of 99.5%, so that there is very little 142b in the effluent. The acids can be either scrubbed out by caustic washing or recovered by distillation. If distillation is used, a pressure distillation is needed to recover HCl with conventional refrigeration. The boiling point of HCl at 130 psig is -26° F. Therefore, if the reactor effluent is to feed the distillation train directly, it is advantageous to run the reactor under pressure. Following HCl distillation, the 143a can be distilled overhead while HF is recovered as bottoms. The overhead product from this distillation would be about 10 mol % HF, which is an azeotropic composition with 143a. This material would then be caustic scrubbed to remove the HF and then dried. The effluent from this system should be 143a with a purity level of about 99.9%. If ultrapurification were desired, the unreacted 142b could be recovered as the bottoms fraction of another distillation column and recycled to the reactor. There are alternative distillation sequences to this distillation sequence. The HF could be recovered in the first column with the HF/143a azeotrope and HCl going overhead. HCl could then be recovered by distillation or all of the acid scrubbed. The final 143a recovery step consists of compression and condensation of this volatile material.
The adiabatic process of the invention provides a method whereby 143a can be made at high enough conversion and selectivity to recover it as product using only an acid removal system. It does this with a very simple reactor design (see FIG. 2) and a very specific range of initial temperatures and HF/142b molar feed ratios.
An extrapolation of this technology is to use 141b or mixtures of 141b and 142b as a feedstock. This is possible because the 141b to 142b reaction has a very mild exotherm (about 1 kcal/mol).
I. Fluorination of 142b using CrF 3 .4H 2 O
EXAMPLE 1: Fluorination of 142b.
Chromium fluoride hydrated powder (CrF 3 .4H 2 O, 200 grams), available from Elf Atotech, was mixed with approximately 10 grams of alumina, and the intimate mixture was pelletized using a catalyst pelletizer. The pelletized catalyst 13 (1/8 inch×1/8 inch) (81 grams) was evaluated in a fixed bed 3/4 inch (inner diameter) by 12 inch Hastelloy reactor 11, shown in FIG. 1. It was heated gradually to 450° C. in a stream of air (20 cc/m) from valve 15 for 18 hours, followed by HF activation (200 cc/m of HF from valve 15 for 18 hours). The temperature was then lowered to 200° C., and a mixture of HF and 142b (molar ratio 1.47) was fed through valves 15 and 17, respectively, of the reactor with a contact time of 35.6 seconds. The reaction products were removed at the bottom of reactor 11 through line 19 and backpressure regulator 16, and were then passed through a scrubbing tower 21, counter current to a stream 22 of alkaline solution, for example, 1-5 normal aqueous potassium hydroxide, which was circulated through line 18 by pump 20, to remove unreacted HF. Alternatively, the HF can be removed by distillation or other methods known in the art. Other aqueous hydroxides, such as sodium or calcium hydroxide suspension, can also be used as the alkaline solution. The product obtained was then passed through a drying tower 23, packed with a drying agent 26, such as anhydrous calcium sulfate. The conversion was periodically checked by passing product automatically through valve 25 to a gas chromatograph 27 equipped with electronic integrator 29. In the apparatus of FIG. 1, pumps 9 and 10 and a backpressure regulator at 16 facilitate operations of the apparatus at higher pressures, e.g. in excess of 100 psig.
Conversion was 100% and selectivity for 143a was also 100%. The process ran under these conditions for 32 hours. This clearly indicates that CrF 3 is a very good catalyst for hydrofluorinating 142b to 143a, without co-feeding air to maintain the catalyst activity. (Table 1, Ex. 1.)
EXAMPLE 2: Fluorination of 142b in the presence of 141b.
Following the completion of Example 1, a mixture of 141b and 142b in equimolar quantities was fed to the reactor of Example 1 together with HF. The molar ratio of HF to the total 141b and 142b (2×141b+142b) was 1.33; contact time was 39.4 seconds; conversion was 100% and selectivity of 143a was also 100%. The process ran continuously for 24 hours at 200° C. (between hours 32 and 56). This shows that CrF 3 catalyst can be used to hydrofluorinate, with great efficiency, a blend of 141b and 142b to the desired product, 143a, without forming co-products. (Table 1, Ex. 2.)
EXAMPLE 3: Fluorination of 142b in the presence of 141b and HCl at 200° C.
The feed mixture of HF, 141b and 142b as described in Example 2, together with HCl (38 mole %) formed the total feed to the reactor used in the previous examples. Contact time was 24.4 seconds, conversion was 99.9% and selectivity for 143a was 99.9% (the other 0.1% [nonselective products] actually represents impurities present in the 141b feed). The process ran under these conditions for 66 hours (between hours 56 and 122) without any evidence of catalyst deactivation. This shows that co-feeding a mixture of 141b and 142b together with HCl does not decrease the performance of CrF 3 catalyst. (Table 1, Ex. 3.)
EXAMPLE 4: Fluorination of 142b in the presence of 141b and HCl at 250° C.
The same feed conditions reported in Example 3 were used to evaluate the catalyst at 250° C. Contact time was 23.8 seconds, conversion was still very high (99.9%) and selectivity for 143a was also 99.9%. The process ran steadily under these conditions for 28 hours (between hours 122 and 150). These data suggest that CrF 3 catalyst is a durable catalyst to hydrofluorinate a mixture of 141b, 142b and HCl at high temperature without forming a major co-product. (Table 1, Ex. 4.)
EXAMPLE 5: Effect of contact time.
Example 4 was repeated except that contact time was lowered to 17.8 seconds by increasing the feed rate of HF, 141b and 142b. Conversion under these conditions was 99.9% and 143a selectivity also was 99.9%. The process ran continuously under these conditions for 74 hours (between hours 150 and 224). (Table 1, Ex. 5a.) When Example 4 was again repeated, this time lowering the contact time to 12.9 seconds, both conversion and selectivity for 143a remained at 99.9%. (Table 1, Ex. 5b.) Upon raising the reaction temperature to 300° C. and further lowering the contact time to 11.7 seconds, the % conversion and selectivity, while somewhat reduced (99.5 and 99.1%, respectively) still exceeded 99%. (Table 1, Ex. 5c.)
EXAMPLE 6: Effect of lower temperature on the catalyst performance.
When the reaction temperature was lowered to 100° C., using the same molar ratio as in Example 2, but a contact time of 44.9 seconds, conversion was only 17% and selectivity was still 100%. The process ran under these conditions for 63 hours. (Table 1, Ex. 6a.) When the reaction temperature was raised to 150° C., and the contact time reduced to 39 seconds, conversion increased to 86% and selectivity remained at 100%. (Table 1, Ex. 6b.)
II. Fluorination using a Cr/Ni/AlF 3 catalyst
EXAMPLE 7:
The preparation and activation of the catalyst (Cr/Ni/AlF 3 ) were performed substantially as described in Example 1A of European Patent Publication No. 0 486 333 A1.
In a rotary evaporator was placed 250 ml of a support containing, by weight, 73% aluminum fluoride and 27% alumina (obtained by hydrofluorination of Grace HSA Alumina in a fluidized bed reactor at 300° C. with a mixture of air and hydrofluoric acid), containing 5 to 10 volume % of hydrofluoric acid. Then, two separate aqueous solutions were prepared:
a) A chromic (acid) solution with nickel chloride added, containing:
Anhydrous chromic (acid): 12.5 g
nickel chloride hexahydrate: 29 g
water: 40 g and
b) A methanol solution containing:
methanol: 17.8 g
water: 50 g
A mixture of these two solutions was then introduced at ambient temperature and under atmospheric pressure over about 45 minutes into the support under agitation. The catalyst was then dried under a flow of nitrogen on a fluid bed at around 100° C. for 4 hours.
The catalyst (63.1 grams) was placed into the reactor. The catalyst was dried at 300° C. using 20 cc/m of nitrogen for five hours, followed by HF gas activation (15 cc/m, which was gradually increased to 40 cc/m over 4 hours). The process of HF activation was maintained for 18 hours. Subsequently, a mixture of HF (60 cc/m) and 142b (20 cc/m) were fed over the catalyst bed at 140° C. The contact time was 47 seconds. Conversion was 100% and selectivity was also 100%. The process ran continuously for 170 hours without any evidence of catalyst deactivation or deterioration. This is a clear indication that Cr/Ni/AlF 3 is an excellent catalyst to hydrofluorinate 142b to 143a.
EXAMPLE 8:
After activating the catalyst as described in Example 7, a mixture of HF and 142b in a molar ratio of 1.3:1 was fed to the reactor at such rate as to provide a contact time of 11.4 seconds. The reaction temperature was 70° C. Conversion was 2.2% and selectivity for 143a was 100%. (Table 2, Run 1) When the process ran at 100° C., conversion was 99.5% and selectivity was 100%. (Table 2, Run 2) The process ran under these conditions for 40 hours. Upon lowering the temperature to 70° C., conversion was reduced to 88.9% and 143a selectivity remained at 100%. (Table 2, Run 3) This shows that the Cr/Ni/AlF 3 catalyst can be further activated during the process of feeding 142b and HF.
EXAMPLE 9: Effect of high temperature on the performance of the Cr/Ni/AlF 3 catalyst.
When the same mixture was fed to the same catalyst as in Example 8 at 300° C., with a contact time of 6.9 seconds, conversion was still very high (99.8%); however, selectivity for 143a was reduced to 99.4%. Other products were: VF 2 (selectivity=0.17%), VClF (0.12%) and VDC (0.27%). (Table 2, Run 4) Upon increasing the temperature further to 320° C., with a contact time of 6.6 seconds, conversion remained at 99.8%, but selectivity for 143a was further lowered to 98.2%; 1132a product increased to 0.56%, VClF to 0.37%, and VDC to 0.85%. (Table 2, Run 5) When the temperature was decreased to 275° C., conversion was 99.9% and selectivity for 143a was 99.7%; 1132a was now reduced to 0.07%; 1131a to 0.04%; and 1130a to 0.13%. (Table 2, Run 6) We believe that the co-products were formed as a result of two consecutive disproportionation processes followed by HCl elimination from 140a as shown below:
1) 142b-->143a+141b
2) 141b-->142b+140a
3) 140a-->VDC+HCl
A summary of the results of Examples 8 and 9 is shown in Table 2. The data in Table 2 indicate that, to avoid olefin formation, process temperature should not exceed 275° C. at a molar ratio of HF/142b below 1.3:1.
EXAMPLE 10: Effect of 141b on the performance of the Cr/Ni/AlF3 catalyst.
The same catalyst used in Example 9 was used to evaluate the effect of 141b in the feed stream. When the following composition: 142b (16.49%), 141b (17.72%), HF (65.78%), molar ratio of HF:2×141b+142b=1.92, was fed at 100° C., at a contact time of 11.5 seconds, over the catalyst bed, conversion was very high (99.6%) and selectivity for 143a was also very high (99.9%). There was no evidence of olefin formation or other co-products. This means that a Cr/Ni/Fluorided Alumina catalyst can be used to hydrofluorinate both 141b and 142b without making undesirable by-products.
EXAMPLE 11: Effect of co-feeding 141b and HCl on the performance of Cr/Ni/Fluorided Alumina at various temperatures.
The following molar composition: 11% 142b, 12% 141b, 32% HCl and 45% HF, molar ratio of HF:2×141b+142b=1.92, was fed at various temperatures (100°-240° C.) and contact times. Conversion was generally >99.0% and selectivity for 143a was 100%, as shown in Table 3. These results suggest that it is possible to feed an impure stream of 142b, containing HCl and 141b, without making co-products.
EXAMPLE 12: Fluorination of 142b in the absence of catalysts. (Comparative Example)
When a mixture of HF and 142b was fed to the reactor at a temperature of 140° C., with a molar ratio of 3:1 of HF:142b, and a contact time 47 seconds, in the absence of catalyst, conversion was zero %. This indicates that the hydrofluorination of 142b to 143a requires a catalyst.
EXAMPLE 13: Evaluation and regeneration of the spent Cr/Ni/Fluorided Alumina catalyst.
Spent catalyst from the pilot plant (which was evaluated under conditions to produce high levels of olefin) containing 12% by weight of carbonaceous material was evaluated using processing conditions which are known to produce very high conversion and high selectivity to 143a as shown below (entry 1).
______________________________________ Contact % % m.r. Time Con- SelectivityCatalyst T °C. HF/142b Seconds version (143a)______________________________________1) spent 100 1.34 11.9 2.96 78.72) regen- 100 1.34 11.9 99.53 99.98 erated______________________________________
The spent catalyst was regenerated by heating the catalyst (20 g) at 350° C. using 20 cc/m of air for 40 hours, followed by 40 cc/m for 16 hours also at 350° C. and finally at 400° C. for 24 hours using 40 cc/m air. The catalyst was then evaluated under similar conditions (entry 2). Conversion was 99.53% and selectivity for 143a was 99.98%. This indicates that the cause of catalyst deactivation is carbonaceous deposit, and the best method to regenerate the catalyst is by using hot air.
TABLE 1__________________________________________________________________________Summary of the pelletized CrF.sub.3 catalyst performance. HF/ Cont. Cat. % 142b × 141b × HCl × (2 × 141b + Time age. % Selec-Ex. T °C. 10.sup.3 10.sup.3 10.sup.3 142b) Sec. hours Conv. tivity__________________________________________________________________________1 200 1.4 0 0 1.47 35.6 32 100 1002 200 .49 .49 0 1.33 39.7 56.2 100 1003 200 .49 .49 1.5 1.33 24.4 121.9 99.9 99.94 250 .49 .49 1.5 1.33 23.8 149.9 99.9 99.95a 250 .98 .98 1.5 1.33 17.8 223.7 99.9 99.95b 250 .98 .98 1.5 1.33 12.9 247.1 99.9 99.95c 300 .98 .98 1.5 1.33 11.7 431.1 99.5 99.16a 100 .98 0 0 1.33 44.9 63 17 1006b 150 .98 0 0 1.33 39 -- 86 100__________________________________________________________________________
TABLE 2______________________________________Effect of reaction temperature on the productdistribution for Cr/Ni/AlF.sub.3.Process Conditions % Selectivity m.r Contact %Temp. HF/ Time Con-Run °C. 142b Seconds version 143a VF.sub.2 141b VDC______________________________________1 70 1.3 11.4 2.2 1002 100 1.3 10.6 99.5 1003 70 1.3 11.3 88.9 1004 300 1.3 6.9 99.8 99.4 .17 .12 .275 320 1.3 6.6 99.8 98.2 .56 .37 .856 275 1.3 7.2 99.9 99.7 .07 .04 .13______________________________________
TABLE 3______________________________________Example 11, Summary of ResultsCatalyst: Cr/Ni/Fluorided AluminaFEED: 11% 142b, 12% 141b, 32% HCl, 45% HFTemperature Contact Time Conversion Selectivity(°C.) (Sec.) (%) (143a, %)______________________________________ 100* 11 99.7 100100 8 97.8 100140 7 99.9 100190 6 99.97 100240 6 99.96 100______________________________________ *No HCL in feed
EXAMPLE 14: Use of Cr/Ni/AlF 3 catalyst at high pressure.
A new feed system was added to the test reactor to allow operation at higher pressures. A 12 inches×3/4 inch I.D. Hastelloy C reactor in a three zone electric furnace, identical to the reactor used in Examples 1-13, was used. The product gas also passed through a recirculating KOH scrubber and Drierite bed to an automatic on-line sample valve, and into an HP 5890 gas chromatograph equipped with a capillary column and FID. This system differed from that of the previous examples in that a back pressure regulator was provided between the reactor and the scrubber and two liquid feed pumps. These were Milton Roy model A771-257 pumps with Teflon diaphragms and a capacity of 26 ml/min. The pumpheads were cooled to about -5° C. The HF pressure was increased to about 40 psig with Helium. The two feed streams were vaporized separately in Hastelloy tubes wrapped with heat tape.
The Cr/Ni/AlF 3 catalyst was loaded and activated as described in Example 7 above. HF and 142b were fed at a molar ratio of 3.2:1 for a 7 second contact time at 100 psig. The temperature profile was controlled to simulate an adiabatic reactor with an inlet temperature of 120° C. and an outlet temperature of 325° C. Conversion was 100%, and selectivity to 143a was 100%.
Next, the 142b feed rate was increased, and the HF feed rate was decreased to change the HF:142b molar ratio to 2.5:1, while maintaining all the other conditions the same. Conversion and selectivity were still both 100%. Finally, the HF:142b ratio was reduced to 2:1. Unsaturated coproduct (mainly VDC) levels varied between about 0.01% and 1%. These results are summarized in Table 4. A comparison of these results with those of Example 9 shows that olefin production occurs at high temperature and low HF:142b ratios.
TABLE 4______________________________________Effect of HF: 142b molar ratio on product distributionusing: Cr/Ni/AlF.sub.3, 325° C., 100 psig,contact time = 7 secondsHF/142b Conversion Selectivity Selectivity(m.r.) (%) to 143a (%) to VDC (%)______________________________________3.2 100 100 02.5 100 100 02.0 100 99.0-99.99 0.01-1______________________________________
Process For Removal of Low Level of Olefinic Material From 143a
The maximum allowable level of olefinic compounds in 143a (particularly if for use in a blend with 125 and 134a as a 502 refrigerant substitute) is 10 ppm. The olefinic compounds have been identified as 1,1-dichloroethylene (1130a), 1,1-difluoroethylene (1132a) and 1-chloro-1-fluoroethylene (1131a). As seen from Example 14, above, these olefinic materials can appear as a co-products in the 143a synthesis, depending on the operating conditions. For example, if the reactor temperature exceeds 275° C. and the molar ratio of HF/142b is less that 2:1, a high level (approximately 1%) of these compounds can be formed.
Therefore, we have investigated the feasibility of efficiently hydrofluorinating these compounds to the corresponding saturated products 141b, 142b and 143a, as shown below: ##STR1##
This process can be carried out in a separate fixed bed post-reactor, downstream from the main reactor, without distilling HCl or HF from the crude product. The post reactor contains the same catalyst, Cr/Ni/AlF 3 , as the main reactor. However, the temperature used for operating this downstream reactor is much lower than the main reactor temperature. In general, the operable temperature range is from about 25° C. to about 200° C. In practice, it is preferable to operate at a temperature between about 50° C. and 100° C.
EXAMPLE 15: Removal of low level of 1132a and 1130a in 143a in absence of HCl
The catalyst, Cr/Ni/AlF 3 (38.8 grams), was charged to the 12 inch×3/4 inch reactor. The catalyst was activated first at 100° C. using 25 cc/m of nitrogen for two hours, followed by feeding a blend of HF (25 cc/m) and nitrogen (25 cc/m) at 200° C. for 18 hours. Subsequently, the following composition (in moles): 143a (90.91%), 1130a (4.545%), 1132a (4.545%), using a 1:1 molar ratio of HF to 143a, was fed at 70° C., with a contact time of 11 seconds. After running for 86 hours, gas chromatography (gc) analysis showed the following composition: 143a (99.917%), 141b (0.045%) and 142b (0.038%), indicating 100% conversion of olefin present in the feed to the saturated compounds 141b and 142b. (Example 15, Table 5.)
EXAMPLE 16: Removal of low level of olefins 1132a and 1130a from 143a by hydrofluorination in the presence of HCl.
The above experiment was repeated in the presence of HCl, the molar ratio of HCl/HF/143a being 2:1:1, and the organic feed composition in moles being 143a (90.910%), 1130a (4.545%) and 1132a (4.545%), at 70° C., contact time 5.6 seconds. After running for 33 hours, gas chromatography analysis of the organic stream showed 143a (99.688%), 1130a (˜0.001%), 141b (0.023%) and 142b (0.288%). A summary of the data is shown in Table 5.
EXAMPLES 17 and 18: Effect of contact time on the hydrofluorination of 1130a, 1132a in the presence of HCl.
EXAMPLE 17:
The process of Example 16 was repeated at 100° C., contact time 5.2 seconds. GC analysis of the organic stream showed 99.95% of 143a and 0.05% of 142b, indicating complete conversion of olefins to saturated product. (Example 17, Table 5.)
EXAMPLE 18:
Repeating Example 17, but reducing the contact time to 4 seconds, and using the same feed composition at 100° C., gave the following results by gas chromatograph analysis, after running for 360 hours: 143a (99.577%), 1130a (0.001%), 141b (0.009%) and 142b (0.413%), as shown in Table 5.
EXAMPLE 19: Removal of low level of 1130a, 1131a and 1132a from 143a in the presence of HCl
A mixture of 143a (86.956%), 1130 (4.348%), 1132a (4.348%), 1131a (4.348%) was hydrofluorinated using a 1:1:1 molar ratio of HF/143a/HCl, at 100° C., 4 seconds contact time, using the same batch of catalyst as in Example 18. GC analysis of the product obtained after running for 48 hours showed 99.896% of 143a, 0.011% of 141b and 0.093% of 142b. There was no evidence of the presence of olefinic material, indicating 100% conversion of olefins (Example 19, Table 5).
EXAMPLE 20: Effect of co-feeding 141b and 365 at high pressure
The Cr/Ni/AlF3 catalyst was prepared and activated as described in Example 7 in the reactor described in Example 14. The reactor was maintained at 300° C. and 125 psig. A mixture of 90 mole % 142b and 10 mole % 141b was fed with HF at a molar ratio of HF/(142b+2×141b) of 5:1 at a contact time of 13 seconds. Conversion was 100% and selectivity for 143a was 100%.
Next, the organic feed was replaced by a feed comprising 83.1 mole % 142b, 9.4 mole % 141b and 7.5 mole % 365 (1,1,1,3,3-pentafluorobutane). The molar ratio of HF/(142b+2×141b) was maintained at 5:1. The 142b and 141b were again completely converted to 143a. The 365 was unreacted and did not affect the catalyst performance.
TABLE 5__________________________________________________________________________Summary of Olefins Removal Process Conditions Con.Inlet Feed Composition Mole % Time Products Wt. %VClF 143a VCl.sub.2 VF.sub.2 HF HCl T °C. Sec. 143a VCl.sub.2 VF.sub.2 141b 142b VClF__________________________________________________________________________Ex. 15 a) 0 47.619 2.381 2.381 47.619 0 70 11 99.917 0 0 .045 .038 0 b) 0 90.91 4.546 4.546Ex. 16 0 24.391 1.219 1.219 24.391 48.780 70 5.6 99.688 .sup. <.001.sup.(1) 0 .023 .288 0 0 90.910 4.545 4.545Ex. 17 0 24.391 1.219 1.219 24.391 48.780 100 5.2 99.95 0 0 0 .05 0 0 90.910 4.545 4.545Ex. 18 0 24.391 1.219 1.219 24.391 48.780 100 4.0.sup.(2) 99.577 .001 0 .009 .413 0 0 90.910 4.545 4.545Ex. 19 1.587 31.746 1.587 1.587 31.746 31.746 100 4.sup.(3) 99.896 0 0 .011 .083 0 4.348 86.956 4.348 4.348__________________________________________________________________________ .sup.(1) The highest we have seen and some times not present. .sup.(2) by adding nitrogen from the top. .sup.(3) By adding nitrogen from the top. a) mole % in the total feed b) mole % in the organic feed
EXAMPLES 21-26: Adiabatic Hydrofluorination
A diagram of a small pilot version of adiabatic apparatus used in Examples 21-26 is shown in FIG. 2. As shown, the reactor 312 comprises a 2 inch diameter Schedule 10 Hastelloy pipe 300, which, in the pilot model, is 8 ft in total length. A top flange 301 and a bottom flange 302 cover the top and bottom, respectively, of pipe 300. The bottom of catalyst bed 303 is about 6 inches above bottom flange 302. Between flange 302 and the bottom of bed 303 are spacers 304 and a few inches of activated carbon. The bottom of bed 303 is designed to be at the same axial location as the bottom temperature probe 305. The nine internal temperature probes are side entering RTD probes. This avoids the use of a conductive thermowell. In the illustrated embodiment, the RTD probes are spaced six inches apart for a total of four feet up the reactor 312.
The reactor 312 is completely enclosed with 1 inch of insulation 308. Outside this insulation, copper coil 309 is wound uniformly along the axial length of the reactor 312. Another 1 inch of insulation 110 is wrapped around the outside of the coil. Either steam or hot oil can be fed to the coil 309 to supply external heat to minimize the driving force for heat transfer from the reactor 312. The insulation between the coil and the reactor is designed to minimize heat transfer in either direction.
On the upstream side of reactor 312 is a double pipe heat exchanger (not shown) which vaporizes the 142b/HF feed mix. On the downstream side of reactor 312 is an in-line filter 315 followed by a control valve 317 to control pressure and then line 319 to a scrubbing and drying system (not shown) to remove acids. After scrubbing and drying, the reactor effluent is sent to an on-line gas chromatography device (GC) (not shown) to analyze the product.
EXAMPLE 21:
The adiabatic reactor described above (FIG. 2) was packed with 5.5 lbs of Cr/Ni/AlF 3 catalyst which had been activated by the procedure described in Example 7 above. Feed rates were 6 lbs/hr of 142b and 4 lbs/hr of HF (HF/142b mol ratio=3.35) and the pressure was 150 psig. The effluent gas was analyzed as 99.972 wt % 143a, with the balance being 142b. There was virtually no olefin down to detectable limits (i.e. <5 ppm). The axial temperature profile is shown below (Table 6):
TABLE 6______________________________________Temperature Profile Along Axis ofAdiabatic Reactor Axial Length Temp ft °C.______________________________________ 0.0 121 0.5 123 1.0 125 1.5 127 2.0 130 2.5 134 3.0 148 3.5 284 4.0 271______________________________________
The drop in temperature between 3.5 and 4.0 ft is due to reactor heat losses. The above steady state profile does not reveal the actual maximum bed temperature since this is located between the two probes. To find this maximum temperature, the feed rates were lowered by 10% to shift the temperature profile up the bed. The probe temperature reading at 3 ft climbed from 148° C. to a maximum of 295° C. Therefore, the adiabatic temperature rise was 174° C.
EXAMPLE 22:
The reactor configuration was identical to that of Example 21. Feed rates were the same as in Example 21, but pressure was lowered to 100 psig. Conversion to 143a was 99.970%, with the remainder being 142b. No olefins were detected. The axial temperature profile is shown below (Table 7):
TABLE 7______________________________________Temperature Profile Along Axis ofAdiabatic Reactor Reactor Length Temp ft °C.______________________________________ 0.0 115 0.5 117 1.0 119 1.5 124 2.0 129 2.5 164 3.0 290 3.5 280 4.0 272______________________________________
When the feed rates were lowered by 10% as in Example 21, the maximum bed temperature was found to be 305° C. The adiabatic temperature rise was about 17° C. higher than in Example 21.
EXAMPLE 23:
The reactor configuration was the same as in Example 21. The feed rates were 7.0 lbs/hr of 142b and 3.5 lbs/hr of HF. This was an HF/142b molar feed ratio of 2.51. The reactor pressure was 150 psig. The conversion was 99.95%, with the balance being 142b. NO olefins were detected (i.e. <5 ppm). The axial temperature profile is shown below (Table 8):
TABLE 8______________________________________Temperature Profile Along Axis ofAdiabatic Reactor Reactor Length Temp ft °C.______________________________________ 0.0 116 0.5 117 1.0 119 1.5 121 2.0 131 2.5 292 3.0 283 3.5 279 4.0 274______________________________________
When the feed rates were lowered by 10% as in Example 21, the temperature climbed to 303° C. at 2.0 ft, indicating this to be the maximum bed temperature. The adiabatic temperature rise was 187° C.
EXAMPLE 24:
The reactor configuration was the same as in Example 21. The feed rates were 5.0 lbs/hr 142b and 4.0 lbs/hr HF. The pressure was 150 psig. The conversion was 99.98%, with the balance being 142b. There were no olefins detected (i.e. <5 ppm). The axial temperature profile is shown below (Table 9).
TABLE 9______________________________________Temperature Profile Along Axis ofAdiabatic Reactor Reactor Length Temp ft °C.______________________________________ 0.0 120 0.5 121 1.0 122 1.5 123 2.0 126 2.5 145 3.0 250 3.5 242______________________________________
When feed rates were lowered by 10%, the maximum bed temperature was found to be 262° C.
EXAMPLE 25:
The reactor configuration was the same as in Example 21. The 142b flow rate was 7.5 lbs/hr and the HF flow rate was 1.8 lbs/hr, for an HF/142b molar feed ratio of 1.8. The wt % 143a in the reactor effluent was 98.8%. The effluent also included 0.43% 142b, 690 ppm of 141b, and 230 ppm of 140a. The distribution of olefins in the reactor effluent was as follows: 5858 ppm of 1130a, 335 ppm of 1131a, and 87 ppm of 1132a. The axial temperature profile is shown below (Table 10):
TABLE 10______________________________________Temperature Profile Along Axis ofAdiabatic Reactor Reactor Length Temp ft °C.______________________________________ 0.0 108 0.5 110 1.0 114 1.5 119 2.0 154 2.5 336 3.0 324 3.5 316 4.0 306______________________________________
When flow rates were lowered by 10%, the maximum bed temperature was identified as 356° C.
EXAMPLE 26:
The reactor configuration was the same as in Example 21. This experiment was designed to test the feasibility of using 141b and 142b as co-feeds. The 142b feed rate was 3 lbs/hr and the 141b feed rate also was 3 lbs/hr. The HF feed rate was 3.2 lbs/hr. The molar ratio of HF in excess of its stoichiometric requirement was 1.97. Conversion of both feeds was 99.97%. 1130a was a non-selective coproduct at a level of 190 ppm. The axial temperature profile is shown below (Table 11):
TABLE 11______________________________________Temperature Profile Along Axis ofAdiabatic Reactor Reactor Length Temp ft °C.______________________________________ 0.0 108 0.5 115 1.0 304 1.5 290 2.0 283 2.5 275 3.0 271 3.5 267 4.0 262______________________________________
While the invention has been described herein with reference to specific embodiments, it is not limited thereto. Rather it should be recognized that this invention may be practiced as outline above within the spirit and scope of the appended claims, with such variants and modifications as may be made by those skilled in this art. | Process for synthesizing 1,1,1-trifluoroethane (143a) in the gaseous phase by reacting 1,1-defluoro-1-chloroethane in gaseous phase in the presence of a Cr catalyst. The process may be run isothermally or adiabatically, without co-feeding air or other oxygen containing gas, in the presence or absence of a Ni, Co, Zn or Mn cocatalyst for the Cr catalyst. The catalyst may be unsupported or supported with a support preferably selected from activated carbon, alumina and fluorided alumina. The formation of olefin byproduct can be kept to less than 10 ppm in accordance with the process of the invention. | big_patent |
FIELD OF THE INVENTION
This invention relates to an improved process for the deacylation and desulfurization of a compound having the formula: ##STR3## In the improved process of this invention hypophosphorous acid is employed in the deacylation and desulfurization to improve product yield and reduce the yield of unwanted impurities.
BACKGROUND OF THE INVENTION
Pyrazolotriazoles, such as those described herein are useful magenta couplers for photographic products. However, they are difficult to synthesize. Only a few synthetic routes are known. One of the preferred synthetic routes involves preparation of the triazolothiadiazines 1 and subsequent desulfurization reaction to give the pyrazolotriazoles 2. The triazolothiadiazines 1 can be prepared in two ways; the first, by reaction of 4-amino-5-mercapto-3-substituted(R)-1,2,4-triazoles (4) with alpha-haloketones, or the second, by reaction of 2-hydrazino-5-substituted-(R')-1,3,4-thiadiazines (5) with acyl halides and subsequent dehydrative ring closure. Both the triazoles 4 and the thiadiazines 5 are readily available from thiocarbohydrazide; ##STR4## The desulfurization of these triazolothiadiazines 1 to the pyrazolotriazoles 2: ##STR5## is effected in two steps; the first, a ring contraction reaction of 1 by heating in acetic anhydride to give 1-acetyl-7-acetylthio-3,6-disubstituted-1H-pyrazolo[5,1-c]-1,2,4-triazoles (6) and, the second, hydrolysis of acetyl groups and desulfurization at the same time with hydrochloric acid to give the desired 2. ##STR6## Although this is the most attractive and practical method for desulfurization among those available, there are several drawbacks in using this as a manufacturing process. The first ring contraction reaction is usually clean and does not render any problem except long reaction time. In fact, the reaction mixture is clean enough to be used in the next step without isolation of 6. However, the subsequent reactions are not straight-forward. The hydrolysis and desulfurization reactions with hydrochloric acid generate not only elemental sulfur as by-product but also many sulfur-containing organic impurities. Among them are two major impurities identified as thione 8 and disulfide 9. These oxidized forms of mercapto intermediate 7 seem to result by the action of elemental sulfur formed during the reaction of 7.
Not only elemental sulfur, but also the sulfur-containing organic impurities are considered detrimental. They can interfere with subsequent reaction steps, e.g. a catalytic hydrogenation of a nitro group on one of the groups R or R' in the above formulae. Also, sulfur is a potential fogger in photographic systems.
Because the process of this invention makes much smaller amounts of these detrimental impurities, and is straight-forward and readily carried out, it is considered to be a significant advance in the art.
SUMMARY OF THE INVENTION
This invention relates to an improved process for the preparation of certain pyrazolotriazoles from their triazolothiadiazine precursors. The improvement comprises a deacylation and desulfurization step conducted in the presence of hypophosphorous acid. Use of hypophosphorous acid reduces the amount of elemental sulfur and the amounts of sulfur-containing organic impurities which are formed when hypophosphorous acid is not used in the reaction mixture.
For example, if hypophosphorous acid is not used in a process for making the compound produced in Example 1, hereinbelow, the thione and disulfide impurities corresponding to formulas 8 and 9 can be produced in significant levels; 5-15 area percent as determined by LC/MS (liquid chromatography/mass spectrographic analysis). Without the hypophosphorous acid, the product of Example 1 is prepared in comparatively low yield, 45-50%. Apparently, the low yield is due to formation of the undesired impurities mentioned above.
In contrast, when the process of Example 1 is used, the desired pyrazolotriazole can be produced in 82% yield and with a purity of 98 area % by HPLC (high pressure liquid chromatography).
The use of hypophosphorous acid in the process of this invention has several advantages besides reducing the amounts of undesirable by-products and increasing the yield of the desired product. For example, use of hypophosphorous acid results in formation of H 2 S by-product rather than sulfur. In view of the gaseous nature of H 2 S and its chemical reactivity, it is readily removed from the reaction zone and trappel, for example, by caustic and sodium hypochlorite. Furthermore, hypophosphorous acid does not reduce nitro groups which are commonly present on side chains in photographic intermediates, or affect other functional groups in the molecule.
In summary, this invention overcomes significant difficulties and provides several advantages. For these reasons, and because the process is straight-forward and economical to carry out, it is readily adaptable by industry.
DESCRIPTION OF PREFERRED EMBODIMENTS
In a preferred embodiment, this invention provides the process for the preparation of a 3,6-di-substituted-1H-pyrazolo[5,1-c]-1,2,4-triazole having the formula: ##STR7## said process comprising reacting an acylated compound having the formula: ##STR8## with an aqueous mixture of hypophosphorous acid and hydrochloric acid or hydrobromic acid to produce hydrogen sulfide and said pyrazolotriazole;
R and R' and R" being inert substituents;
said process being characterized by generating less sulfur and sulfur-containing organic impurities than when no hypophosphorous acid is present.
In another preferred embodiment, this invention provides a process for the preparation of a 3,6-di-substituted-1H-pyrazolo[5,1-c]-1,2,4-triazole having the formula: ##STR9## from a 3,6-disubstituted-7H-1,2,4triazolo[3,4-b]-[1,3,4]thiadiazine having the formula: ##STR10## wherein R and R' are alike or different and are selected from photographically acceptable, inert substituents;
said process comprising: (i) reacting compound (I) with an acylating agent to form an acylated intermediate ##STR11## and (ii) subsequently reacting said acylated intermediate with an aqueous mixture of hypophosphorous acid and hydrochloric acid or hydrobromic acid to produce hydrogen sulfide and pyrazolotriazole (II);
said process being characterized by generating less sulfur and sulfur-containing organic impurities than when no hypophosphorous acid is present in step (ii).
In the compounds used as starting materials in this invention, and the compounds produced as intermediates, as well as the desired products, all represented by Formulas 1-9 above, R and R' are "inert substituents".
For the purpose of this invention, an "inert substituent" or "inert organic group" is defined by having the following characteristics:
(1) It is stable, or substantially stable, under the process conditions employed: i.e. it does not decompose to an untoward extent during process(es) employed in this invention.
(2) It is non-reactive, or substantially non-reactive toward the other reagents employed, i.e. it does not undergo an extraneous side reaction (to an unacceptable extent) with the other ingredient(s) used.
(3) It does not prevent, by steric hindrance or other mechanism or effect, the formation of a compound of this invention.
Thus, a wide variety of substituents may appear as R and/or R' in the above formulas. In other words, this invention is not critically dependent on the type(s) of groups designated R and R', so long as the groups meet criteria (1), (2) and (3) above. Typically, R and R' are hydrocarbyl groups, i.e. groups which are solely composed of carbon and hydrogen. However, it is not necessary that R and R' be solely composed of carbon and hydrogen; thus groups which comprise: ##STR12## NO 2 , --NH 2 , NHR, NRR, --SO 2 --, --S--, and alkoxy, aryloxy, the like, can appear in compounds of this invention, so long as the substituents meet the three criteria enumerated above. Alkyl, cycloalkyl, alkenyl, cycloalkenyl, aryl, aralkyl, heteroaryl groups and heterocyclic groups containing oxygen, sulfur or nitrogen as the heteroatom which meet the above criteria can be present in the compounds of this invention. These may be hydrocarbyl, or substituted hydrocarbyl groups, as discussed above. For convenience, R and R' are usually hydrocarbyl groups having up to about 20 carbon atoms; preferably they are hydrogen or alkyl or aryl groups of this type.
When the radical R" appears in compounds of this invention, it represents lower alkyl radicals, preferably those having up to about 6 carbon atoms. In compounds of this invention R and R' may be alike or different.
The R, R' and R" radicals are generally selected according to the properties that they confer on the compounds, and/or the role that they play in the selected utility. For example, since the radical R" appears in a group which is to be subsequently removed by hydrolysis, R" is preferably selected from a methyl or ethyl, or other lower alkyl group having up to about four carbon atoms in order to lower process costs.
On the other hand, the size or nature of the group may be selected because it is produced in a convenient reaction for preparing the pyrazolotriazole starting compound, or the group may be selected to confer some physical or chemical property, such as a desired degree of solubility, or a desired degree of compatibility with other ingredients in a mixture in which the product is used.
Moreover, one or more of the radicals R and R' may be selected to contain a radical which contains a reactive site. For example, R may be a group having the formula: ##STR13## wherein n is a whole number equal to 0 to about 6, and the nitro group is ortho, meta or para to the alkyl side chain. For some uses, it is desirable to subsequently reduce the aryl nitro group to an amino group. Accordingly, it is to be understood that the term "inert" in the phrase "inert substituent" does not mean that the substituent is unreactable in processing conducted after the compound is made.
As indicated above, compound (III) can be prepared by an acylation reaction. For the acylation an anhydride having the formula: ##STR14## is employed.
The acylating agent may be used in solvent quantities. There is no real upper limit on the amount of acylating agent; this being defined by such secondary characteristics as economics, size of the reaction vessel, ease of separation of product from the reaction mixture, ease of recovery of the unreacted acylating agent, etc.
The process may be conducted in the presence of a catalytic quantity of a Bronsted or Lewis acid. For the purpose of this invention, a Bronsted acid is any proton donor which donates a proton and does not hinder the process. Such materials are generally selected from alkyl sulfonic acids, hydrogen halides, sulfuric acid, and carboxylic acids such as those acids mentioned above for use as acylating agents. Lewis Acids, such as those employed for Friedel-Crafts acylations, e. c. AlCl 3 , FeCl 3 BF 3 , HF, H 3 PO 4 and the like, can also be used as catalysts.
Generally speaking, a catalytic amount of such catalyst, e.g. from about 0.05 to about 0.25 moles per mole of starting triazolothiadiazine is used. Greater or lesser amounts can be employed if they afford the desired result.
The acylation may be conducted at any convenient temperature which gives a reasonable rate of reaction, and which does not cause an undue amount of decomposition of one or more of the ingredients employed. Generally speaking, a temperature within the range of from about 20° C. to about 200° C. is employed; more preferably the temperature is from about 100° C. to about 150° C.
Ambient pressure is generally satisfactory. Higher pressures, up to 100 atmospheres or more can be used if one of the reagents is a gas or vapor at the reaction temperature.
The process is generally conducted in the substantial absence of water or with a small amount of water to prevent unwanted hydrolysis.
The reaction time is not a completely independent variable, but is dependent at least to some extent on the other reaction conditions employed, and the inherent reactivity of the reactants. In general, higher reaction temperatures require shorter reaction times. The process is usually complete in from about 0.5 to about 24 hours.
After the acylation has been conducted, it may be desirable to add water to the reaction mixture in order to hydrolyze any excess acid anhydride. The water addition may be accompanied by agitation of the reaction mixture (e.g. by stirring) to facilitate hydrolysis.
After any hydrolysis is conducted as discussed in the paragraph immediately above, the deacylation and desulfurization reaction can be conducted on the reaction mixture produced. In other words, it is not necessary to isolate compound (III) in order to conduct the next step. Although isolation is not necessary, it can be carried out if desired, using techniques within the skill of the art, e.g. fractional crystallization, distillation, extraction and the like.
The deacylation and desulfurization is generally conducted at a temperature which gives a reasonable rate of reaction, but which does not cause unwanted, extraneous side reactions to take place with loss of yield of desired product. For example, temperatures of from 50° to 100° C. can be employed; generally it is preferred to use a temperature of from 70°-90° C.
Ambient pressures are preferred; however, somewhat elevated pressures can be used if the reaction is to be conducted at a temperature above the boiling point of one or more of the constituents in the reaction mixture.
The deacylation/desulfurization is generally conducted using a hydrochloric acid or hydrobromic acid. In general, the amount of acid is at least stoichiometric; however, an excess of acid can be employed if desired. The amount of hypophosphorous acid (H 3 PO 2 ) employed is preferably at least equimolar with the thiadiazine. However, additional H 3 PO 2 can be used if desired.
The reaction time is not a truly independent variable, but is at least somewhat dependent on the reaction temperature and the inherent reactivity of the reactants. In general, reaction times of from 0.5 to 10 hours are sufficient.
After the desulfurization reaction is complete the desired pyrazolotriazole can be isolated from the reaction mixture by a known technique such as extraction, as indicated by the following examples.
EXAMPLE 1
6-Methyl-3-[1-(4-nitrophenoxy)tridecyl]-1H-pyrazolo-[5,1-c]-1,2,4-triazole
A mixture of 47.4 g (0.10 m) of 6-methyl-3-(1-[4-nitrophenoxy]tridecyl)-7H-1,2,4-triazolo[3,4-b]-[1,3,4]thiadiazine (1a) and 150 g of acetic anhydride is heated under reflux for 7 hours and left at room temperature over night. Acetic acid (30 g) is added and the mixture is heated to 60° C. A solution of 12.5 g of c-HCl (36%) in 15 ml of water is then added over 20 minutes to assure that hydrolysis of acetic anhydride is complete.
The mixture is cooled to 30° C. and there is added 50.8 g of c-HCl, 13.2 g of 50% hypophosphorous acid, and 56 ml of water. The mixture is slowly heated to 85° C. and stirred at that temperature for 3 hours. During the heating period a gentle gas evolution occurs. The gas is passed through a pre-scrubber solution made of caustic and sodium hypochlorite. The product is extracted with 210 ml of toluene at 65° C. and the toluene solution is washed with hot water (65° C.) 4-5 times to remove acids. While keeping the temperature at 65°-70° C., 230 ml of hot heptane (65° C.) is added and the mixture is cooled slowly without stirring to room temperature. The crystallized product is collected, washed well with 1:1 mixture of toluene and heptane, and dried to give 36.2 g (82%) of 6-methyl-3-[1-(4-nitrophenoxy)-tridecyl]-1H-pyrazolo-[5,1-c]-1,2,4-triazole(2a) with 98 area % by HPLC.
EXAMPLE 2
6-t-Butyl-3-(3nitro-2,4,6-trimethylphenyl)-1h-pyrazolo-[5,1-c]-1,2,4-triazole (2b)
With 6-t-butyl-3-(3-nitro-2,4,6-trimethylphenyl)-7H-1,2,4-triazolo-[3,4-b][1,3,4]thiadiazine (1b), the reaction is carried out as Example 1. After the reaction is complete, the reaction mixture is filtered while hot and drowned out into the water. The precipitated product is collected, washed well with water, and dried. It is slurried in 1:1 mixture of toluene and heptane, and dried again to give the product 2b in 78% yield with 98 area % by HPLC.
In the following example, all parts are by weight.
EXAMPLE 3
A suitable glass-lined reactor is purged with nitrogen to less than 8% oxygen. Thereafter 669 parts of 6-methyl-3-[1-(4-nitrophenoxy)-tridecyl]-7H-1,2,4-triazolo[3,4-b][1,3,4]thiadiazine is charged to the reactor. Thereafter 238 parts of acetic anhydride is metered into the reactor. The agitator is started and the contents heated to 133° C. by using 140° C. steam applied on the jacket. The reaction mixture is maintained at 133° C. for 20 hours. Thereafter, the batch is cooled to 50° C. and sampled for completeness of reaction. If the reaction is complete (less than 2.0% of starting thiadiazine) the batch is cooled and pumped to a receiver or transferred directly to a second reactor.
Hydrochloric acid, 32%, 1690 parts, and 412 parts of 50% hypophosphorous acid are admixed in a reactor receiver. A solution of 100 parts of 32% hydrochloric acid and 1500 parts of filtered water is prepared in the second reactor and heated to 70° to 80° C. Two reaction batches prepared as above and containing the non-isolated 1-acetyl-7-acetylthio-6-methyl-3-(1-[4-nitrophenoxy]tridecyl)-1-H-pyrazolo(5,1-c)-1,2,4-triazole are cautiously transferred to the second reactor while maintaining the contents temperature at 70°-80° C. The hydrochloric acid/hypophosphorous acid solution in the receiver is charged to the second unit at such a rate as to maintain the batch at a temperature less than 80° C. The resultant reaction mixture is maintained at 75°-80° C. for an additional three hours by applying tempered water on the jacket.
Off gasses are vented to an appropriate scrubber. The resulting mixture is checked for completeness of reaction and cooled to 65° C.
If the reaction is complete 1500 parts of toluene is added to the reaction mixture while maintaining the temperature at 65°-70° C. The resultant mixture is settled and the bottom aqueous layer discarded. The toluene layer is washed once with water and twice with water containing 50 parts of sodium chloride. All washes contained 5000 parts of filtered water. During the washings the temperature is maintained at 65°-70° C.
To the washed toluene layer is added 4800 parts of heptane while maintaining the temperature at 70°-75° C. The resultant mixture is then seeded using 20 parts of 6-methyl-3-[1-(4-nitrophenoxy)-tridecyl]-1-H-pyrazole(5,1-c)-1,2,4-triazole. The resultant mixture is then cooled to 18°-22° C. and held at that temperature for 30 minutes.
The resultant mixture is then filtered and the product cake washed with heptane and toluene (1500 parts of each) and then dried and packaged in drums with clear plastic liners.
A suitable stainless steel or glass lined reactor is purged with nitrogen to less than 8% oxygen. Thereafter toluene, 4,040 parts is metered into the reactor and the agitator started. One entire batch of crude 6-methyl-3-[1-(4-nitrophenoxy)-tridecyl]-1-H-pyrazole(5,1-c)-1,2,4-triazole, approximately 900 parts, is charged to the reactor and the batch heated to 70°-75° C. using steam. The batch is maintained in that temperature range for one hour. An additional 4,040 parts of heptane is metered into the batch while maintaining the batch temperature at 70°-75° C. The resultant solution is then cooled to 69° C. and seeded using 20 parts of recrystallized 6-methyl-3-[1-(4-nitrophenoxy)-tridecyl]-1-H-pyrazole(5,1-c)-1,2,4-triazole. The batch is then cooled in a controlled manner to 18°-22° C. and held at 18°-22° C. for 30 minutes. The batch is filtered and the cakes are washed with a mixture of 1500 parts of heptane and 1500 parts of toluene. There is recovered recrystallized 6-methyl-3-[1-(4-nitrophenoxy)tridecyl]-1-H-pyrazole (5,1-c)-1,2,4-triazole.
The invention has been described above with particular reference to preferred embodiments thereof. A skilled practitioner, aware of the above detailed description can make many modifications or substitutions without departing from the scope or spirit of the following claims. | Pyrazolotriazoles such as 3,6-disubstituted-1H-pyrazolo[5,1-c]-1,2,4-triazoles: ##STR1## are useful in the photographic arts, e.g. as magenta couplers. They may be made from 3,6-disubstituted-7H-1,2,4-triazolo[3,4-b][1,3,4]thiadiazines: ##STR2## by a two-step process. The first step comprises a ring contraction and a diacylation. The second step comprises hydrolysis of the acyl groups and desulfurization. The second step is conducted using an aqueous mixture of a hydrohalic acid such as hydrochloric acid and hypophosphorous acid, H 3 PO 2 . When the hypophosphorous acid is used, less sulfur and sulfur-containing impurities are formed. | big_patent |
BACKGROUND OF THE INVENTION
This invention relates to a method and apparatus for forming fiber mixtures from a plurality of fiber types by sequentially taking, from different fiber lots such as fiber bales, partial quantities which are small with respect to the entire quantity of the mixture.
German Laid-Open Applications (Offenlegungsschriften) Nos. 1,685,596 (to which corresponds U.S. Pat. No. 3,577,599) and 2,063,415 disclose a method according to which a plurality of fiber bales containing the same kind of fiber are positioned next to a plurality of fiber bales of another type of fiber. A carriage is moved past the fiber bales and the bale opener mounted thereon takes from each fiber type a partial quantity so that the composition of the partial quantities obtained during each pass has the desired predetermined mixture ratio. At the same time, care is taken that, in case the required individual partial quantity of one fiber type is not reached during the opening operation of one pass, the carriage does not move on to the subsequent fiber type, but is ordered to return for making up the deficiency. Although such a method is adapted for obtaining a mixture of predetermined proportions of fiber types wherein the individual proportions are in each instance taken from a plurality of fiber bales, several disadvantages are involved with this method. The individual fiber bales even of the same fiber type have fluctuating dimensions, compressions and weights. According to the method, such an amount of fiber material is removed each time from a plurality of fiber bales of one fiber type until a quantity corresponding to the intended proportion is reached. Thus, during each pass of the carriage (on which the opener is mounted), from a plurality of fiber bales of one fiber type a predetermined quantity has to be removed or has to be complemented, while the quantities remaining in the fiber bales are not taken into account at all. As a result, it is unavoidable that in the individual fiber bales eventually residual fibers remain which disturb to a substantial extent the rhythm of operation, since they have to be processed separately, thus requiring undesirable additional labor and expense. It is a further disadvantage that a partial quantity is always taken from a plurality of fiber bales, so that the mixture can be obtained only in steps and therefore it cannot be optimally homogeneous.
SUMMARY OF THE INVENTION
It is an object of the invention to provide an improved method of the above-outlined type from which the discussed disadvantages are eliminated, thus ensuring that the opening of all fiber bales is effected without fiber residuals and further, that an optimally homogeneous mixture is obtained.
This object and others to become apparent as the specification progresses, are accomplished by the invention, according to which, briefly stated, at each stored fiber lot, prior to the first pass or prior to each pass of the bale opener, the entire momentary quantity of the stored fiber lot (fiber bale) is measured and, from the measurements, a certain partial quantity is determined which corresponds to a predetermined proportion of the momentary entire quantity and further, the determined partial quantity is continuously removed only from the measured fiber lot.
Thus, in contradistinction to the known process, only a single fiber bale is provided for each fiber type; further, the measuring is effected directly at the location of fiber opening. Thus, according to the invention, before each opening pass, the fiber bales are individually measured, the partial quantity is calculated and then, from each fiber bale only the respective calculated fiber quantity is removed during the pass. These partial quantities are taken off the fiber bales in sequence in a predetermined number of bale opening passes. Thus, as from each fiber bale of one series the calculated partial quantity is sequentially removed in one pass, the operation is repeated in the same manner during the successive pass. It is essential that the partial quantity corresponds to a predetermined proportion of the momentary entire quantity of the fiber bale. In this manner all fiber bales are opened without fiber quantities remaining. During the last pass in each instance the last partial fiber quantity remaining in each fiber bale is processed. It is an advantage of the method according to the invention, that for each pass the partial quantity is determined anew for each fiber bale. If, in practice, instead of the determined partial quantity, a larger or smaller partial quantity is removed, such a deviation can be corrected during the next pass because, in any event, a new calculation is effected. It is a further advantage that during each pass, from each fiber bale only a single partial quantity is removed. In this manner, during each pass a finely dosed mixture of the same composition can be formed from as many components as there are fiber bales to be processed.
According to a further feature of the method according to the invention, at each fiber storage site, prior to fiber removal, the initial total fiber quantity is measured and then, from the measurements a predetermined partial quantity is calculated which corresponds to a predetermined proportion of the initial total quantity and further, the determined partial quantity is removed continuously only from the measured stored fiber lot.
According to the invention, thus only the initial total quantity of each fiber bale is measured and a constant partial quantity is calculated once. These partial quantities are removed from the fiber bales in succession in a fixed number of passes. This method is particularly adapted for making mixtures of throughout constant quantity proportions.
It is a further disadvantage of the known processes that no time period is set for the removal of the individual quantity proportions. The bale opener mounted on the carriage removes fiber material from each fiber lot until the intended quantity is reached. While during one particular pass, the desired quantity may be reached immediately, it can happen that during another pass, the carriage has to be returned to remove additional material. This results in delays which means that although equal quantities are fed to an after-connected charging device for a further processing apparatus, for example, a reserve hopper of a tuft-feeding device for a carding machine, the periods of delivery are not uniform. Risks are particularly high that, because of the delays, the bale opener delivers less fiber tufts than what the after-connected machines can process, resulting in a wasteful idle run of such machines. For avoiding this disadvantage, according to a preferred embodiment of the method according to the invention, the partial quantity from each stored fiber lot is removed not later than by the end of a predetermined period. In this manner a determined time schedule can be maintained in the opening of the fiber bales. A supply of the after-connected processing machines with fiber tufts can be ensured by coordinating the output rate of the bale opener with that of the after-connected processing machines, thus preventing the latter from running idle. In this manner the opening of the fiber bales can be effected within a predetermined period.
Preferably, the fiber removal from the stored fiber lot can be accelerated to ensure that the partial quantities are removed not later than the lapse of the predetermined period.
The invention further relates to an apparatus for performing the above-outlined method according to the invention. The apparatus includes a bale opener for removing fibers from the various stored fiber lots, as well as a quantity measuring device associated with the opener and a control device which controls the mode of operation of the opener as a function of the signals transmitted by the quantity measuring device.
The bale opener may be, for example, a plucker, a stripper roll, a spiked apron or a picker. As a quantity measuring device there may be used a frequency counter or a weighing device known by themselves. The quantity measuring device is preferably a height-measuring arrangement which effects a simple and accurate determination of the partial fiber quantities to be removed from the bales. The quantities removed or to be removed can be determined in a simple manner as a function of the height of the fiber bale. The height-measuring device may comprise, for example, a light barrier or an electromechanically operating sliding potentiometer.
Expediently, the quantity measuring device is movable with the bale opener along the stored fiber lots (fiber bales) so that measurements can be taken directly at the location of fiber removal. The opening device may operate in a discontinuous manner by moving vertically up and down or may be displaceable in any other known manner.
Preferably, the control arrangement has a control apparatus and a computer; the control arrangement determines the precise partial quantities to be removed and also, controls the fiber removing operation. It is expedient to provide the control device with a timing relay which predetermines a maximum period to ensure that the partial quantity from each stored fiber lot is removed not later than at the end of the predetermined period.
The control apparatus has, among others, the function of controlling the displacement of the transporting device (carriage) on which the bale opener is mounted. For this purpose, an output of the control apparatus is connected with the drive of the carriage. For positioning and starting the carriage, preferably switch contacts are provided which too, are connected with the control apparatus. Expediently, for reversing the direction of operation of the bale opener, there are provided two limit switches which are connected with an input of the control apparatus. These limit switches have the advantage that the control apparatus receives a signal immediately as a pass is completed; in this manner the number of passes remaining is reduced by one.
The control apparatus further has the additional function of controlling the beginning and the end of the bale opening operation regarding the removal of the partial fiber quantity. For this purpose, the control apparatus is connected with the drive of the bale opener. The control apparatus maintains the drive motor of the opener energized until the partial quantity is removed from the bale. As a starting signal one may use, for example, the signal emitted by the switch contacts of the carriage. The signal for stopping the motor is derived by the control apparatus from a signal which, in turn, is generated by the quantity measuring device and the computer and is transmitted when the predetermined partial quantity has been removed. This signal can, at the same time, be used as the signal for commanding the carriage to continue its travel.
Preferably, the drive of the bale opener is a pole-reversible electromotor which accelerates the operation of the bale opener if, for example, in case of particularly hard (compressed) bales, the partial quantity is not removed within the predetermined period.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic side elevational view of a preferred embodiment of the invention.
FIG. 2 is a schematic perspective view of the structure shown in FIG. 1.
FIG. 3 is a schematic front elevational view of another preferred embodiment of the invention.
FIG. 4 is a sectional side elevational view of a detail of the structure illustrated in FIG. 3.
FIG. 5 is a block diagram of a computer used in the apparatus according to the invention.
FIG. 6 is a circuit diagram of a component shown in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
For performing the method according to the invention, there are provided a fiber removing apparatus, a quantity measuring apparatus and a control apparatus which controls the mode of operation of the fiber removing apparatus. The fiber removing apparatus as well as the quantity measuring apparatus may be of any selected type.
Turning now to FIGS. 1 and 2, in a preferred embodiment of the apparatus according to the invention, a series of textile fiber bales 1a, 1b and 1c are arranged side-by-side on a bale support, under which travels a carriage 3 on which there are mounted two spiked fiber bale opener aprons 4, 5, constituting a fiber removing apparatus 2. On the carriage 3 there is laterally mounted a height-measuring device 6 which constitutes a fiber quantity measuring apparatus and which is, in essence, a light barrier formed of a light transmitter 7 and a light receiver 8. The upper ends of the light barrier project upwardly beyond the maximum expected height of the fiber bales. The receiver 8 of the height-measuring device 6 is connected, by the intermediary of a computer 9, with an input of a control device 10 coupled to a timer 11. An output of the control device 10 is connected with a drive motor 12 of the carriage 3. At one end, the carriage 3 has a switching element 13 which consecutively engages contacts 14a, 14b and 14c, laterally mounted on the machine frame at bales 1a, 1b and 1c, respectively. The switching element 13 is coupled with an input of the control device 10 so that as the bale opener 2 reaches its starting position, a signal is applied to the control device 10. The signal starts the measuring process, the displacement of the carriage 3 as well as the rotation of the breaker aprons 4 and 5. The switching contacts 14a, 14b and 14c may also be utilized for reversing the drive of the carriage 3 in case the determined partial quantity is removed from the bales continuously by several back-and-forth passes. In such a case, the switching element 13 transmits a reversing signal to the control device 10 as the switching element 13 engages one of the switching contacts 14a or 14b, respectively. At each of the two ends of the bale support (only one end shown in FIGS. 1 and 2) there are provided limit switches 15a, 15b, respectively, which are connected with inputs of the computer 9 and which are actuated by the carriage 3. The control device 10 has an output which is connected with a pole-reversible drive motor 31 of the breaker aprons 4, 5.
Turning now to the front elevational FIG. 3, in another preferred embodiment shown therein, the apparatus according to the invention has a fiber removing apparatus which opens the fiber bales from above and which has an electromechanical height-measuring device. The fiber bales (of which only bale 1a is visible in FIG. 3) are positioned on a platform 30 supported on the floor. Adjacent the platform 30 there are provided rails 16 on which a vertical stand 18 may travel by means of rollers 17, propelled by a motor 27. A horizontal support arm 19 is height-adjustably mounted on the stand 18 by means of a securing member 20. The support arm 19 carries a bale opener 21 adapted to engage each fiber bale on the top. A motor 22 drives, in a manner not shown, an opening roll 23 as well as delivery rolls 24 of the bale opener, as seen in more detail in FIG. 4. Parallel to the stand 18 there is arranged a vertical measuring device 25 which, in essence, is formed of a sliding potentiometer. The vertically displaceable securing member 20 is coupled by means of a contact member 26 with the measuring element 25, so that a displacement of the securing element 20 is a measure for the change of height of the bale opener 21 and thus is a measure of the height of the removed fiber quantities. The fiber removing operation performed by the bale opener 21 may be time-controlled and quantity-controlled. Consequently, after the lapse of a predetermined period or upon reaching a predetermined tuft quantity, the bale opener is lifted off the fiber bale which has just undergone opening and is moved to an adjacent fiber bale and is then lowered to resume the opening operation. In this manner a programmed fiber removal can be effected, that is, a predetermined quantity of fine fiber tufts can be obtained in a predetermined mixture ratio in a predetermined time period for further processing, for example, in a cleaner. The control described in connection with the embodiment shown in FIGS. 1 and 2 may find application in the arrangement of FIG. 3 as well. After removing the predetermined partial quantity, the support arrangement 18, 19 and 20 with the bale opener 21 is, as commanded by the control device 10, displaced to the adjacent fiber bale. At the foot of the stand 18, there is mounted a switch 28 which is oriented towards the fiber bales and which is connected with an input of the computer 9. The switch 28 engages electric switch contacts 29 (only one shown) associated with each fiber bale and mounted laterally on the platform 30. The reversal of the operation of the fiber removing apparatus 21 at the end of the fiber bale series can be effected by the actuation of a limit switch as described in connection with the embodiment shown in FIG. 1. As an alternative, it is feasible to initially set the number of the fiber bales at the control device 10, so that both the reversal of the fiber removing apparatus 21 and the reduction of the number of passes by one are performed automatically.
Turning now to FIG. 5, there is illustrated the relationship between principal components of, for example, a commercially available microcomputer 9. The computer has inputs, for example, to receive signals from the switching element 13 and the height measuring device 6 as well as an output, for example, to apply signals to the control device 10. The microcomputer 9 conventionally includes a unit for the system program, a central unit (CPU) and data memories, all interconnected in a known manner.
The essential function of the microcomputer 9 resides in continuously counting the electrical pulses emitted by the light barrier 6, in determining the actual height of the fiber bale from a comparison with the original height and in emitting appropriate instructions to the control device 10 for the motors 12 and 31.
Turning now to FIG. 6, there is schematically shown the logic circuit for the inputs and outputs of the control device 10 which may be a commercially available programmable control. The control circuit includes a NOR gate 34, the two inputs of which receive signals from the respective limit switches 15a and 15b. The output of the NOR gate 34 is connected to an input of AND gates 32 and 33, whose other input, in turn, receives signals from the computer 9. The output of the AND gate 32 is connected to the motor 31 whereas the output of the AND gate 33 is connected to the motor 12.
A fixed program is fed into the control device 10 which, based on this program and upon the actual instructions from the computer 9, controls the motors 12 and 31.
The method according to the invention will be described in three examples which follow.
EXAMPLE 1
It is assumed that twenty fiber bales of significantly different initial heights are to be opened by the arrangement illustrated in FIGS. 1 and 2. It is desired that each fiber bale should be fully opened in the course of 100 passes. For the fiber removal during the first pass, the fiber removing apparatus 2 moves, with the height-measuring device 6, under the first fiber bale 1a. First, however, the total height of the fiber bale 1a is measured. The light transmitter 7 and the receiver 8 of the light barrier are 200 cm tall. The light source of the transmitter 7 radiates light over the entire height of 200 cm; of this light, one part impinges on the fiber bale 1a and another part, for example 10 cm, reaches the photocells of the receiver 8. As a response, the receiver 8 applies electric signals to the computer 9 which determines that the total height of the fiber bale 1a is 190 cm. Since the fiber removal is to be performed in the course of 100 passes, for the first partial quantity removal, a height of 1.9 cm is determined. After 1.9 cm has been removed from the total height of 190 cm in the first pass, the fiber removing apparatus moves on to the next fiber bale 1b where, in the same manner, a predetermined partial quantity is set and subsequently removed. Thus, the fiber removing apparatus 2 moves onto the adjoining fiber bale only when the entire determined partial quantity has been removed from the previous bale. At the end of the bale series, after the determined partial quantity is removed from each fiber bale, the number of passes still to be performed is reduced by one to ninety-nine.
The Table at the end of the Examples indicates for each fiber bale the individual total height before fiber removal, the fiber quantity to be removed and the individual total height after removal.
EXAMPLE 2
This example, which is discussed in conjunction with the apparatus illustrated in FIGS. 3 and 4, generally corresponds to Example 1; the partial quantity, however, is removed from each bale not later than at the end of a predetermined period. For the removal of a partial quantity from the fiber bale 1a, the control device 10 is set by the timer 11 for a removal period of 0.5 minutes in addition to the total height of 1.9 cm to be removed. The fiber removing apparatus 21 removes fiber from the first fiber bale 1a for a certain period, for example 0.25 min. Thereafter, the actual height is determined and, by means of the computer 9, there is performed a comparison between the desired quantity to be removed and the quantity actually removed. If after 1/2 of the predetermined period, that is, after 0.25 min., the first half of the partial quantity to be removed, that is, 0.95 cm has been reached, the second half is removed with the same speed as the first half. If, however, after the first half of the predetermined period, one half of the material to be removed has not yet been reached, that is, less than 0.95 cm was removed, the control device emits an electric signal to the drive motor 22 to accelerate its rotation so that the rolls 23 and 24 will effect a faster removal of fiber from the fiber bale 1a.
EXAMPLE 3
It is feasible to set, for the different fiber bales 1a, 1b, etc., different fiber removal periods for the partial quantity, for example, in each instance a period between 0.5 min. and 2 min. This means, for example, that the partial quantity must be removed from the fiber bale 1a not later than in 0.5 min., from the fiber bale 1b not later than in 1 min. and from the fiber bale 1c not later than in 0.75 min.
TABLE__________________________________________________________________________Fiber Bale No. 1 Fiber Bale No. 2 Total height Total height Total height Total height prior to Partial after removal prior to Partial after removal removal of quantity to be of partial removal of quantity to be of partial partial quantity, removed, quantity, partial quantity, removed, quantity, in cm in cm in cm in cm in cm in cm__________________________________________________________________________1st pass 190 ##STR1## 188.1 200 ##STR2## 1982nd pass 188.1 ##STR3## 186.2 198 ##STR4## 1963rd pass 186.2 ##STR5## 184.3 196 ##STR6## 1944th to99th pass100th pass zero zero__________________________________________________________________________ Fiber Bales No. 3 to 19 Fiber Bale No. 20__________________________________________________________________________ Total height Total height prior to Partial after removal removal of quantity to be of partial partial quantity, removed, quantity, in cm in cm in cm__________________________________________________________________________ 1st pass 170 ##STR7## 168.3 2nd pass 168.3 ##STR8## 166.6 3rd pass 166.6 ##STR9## 164.9 4th to 99th pass 100th pass zero__________________________________________________________________________
It is to be understood that the above description of the present invention is susceptible to various modifications, changes and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims. | A method of forming fiber mixtures from different kinds of fiber includes the step of removing the fiber in a plurality of passes from a plurality of stored fiber lots containing the different kinds of fiber. During each pass, fiber is removed from consecutive stored fiber lots in partial quantities that are small relative to the entire fiber quantities in the stored fiber lots. According to the method, prior to fiber removal in the first pass, the entire fiber quantity in each stored fiber lot is separately determined and from such entire fiber quantity there is determined, for each stored fiber lot, a partial quantity to be removed from each stored fiber lot during the first pass. Each partial quantity represents a proportion of the entire fiber quantity of the respective stored fiber lot. Thereafter, at least during the first pass, the determined partial quantity is removed from the respective stored fiber lot. | big_patent |
This is a division of application Ser. No. 922,344, filed Oct. 23, 1986 now U.S. Pat. No. 4,877,470.
FIELD OF THE INVENTION
The present invention is directed to method and apparatus for forming bias laid, non-woven fabrics wherein, preferably, the yarns in at least two of the layers of fabric are laid at an angle of from 30° to 150° to the long axis of the fabric. In such fabrics, the yarns in the various layers are neither knitted, nor woven, but are held together by stitching through the layers, or by other external means, such as adhesive bonding.
THE PRIOR ART
The history of fabric formation is a long one. Most fabrics are made by the now traditional processes of knitting, weaving, etc., and sophisticated machinery has been developed for automatically manufacturing fabrics in accordance with these techniques.
For many modern usages, particularly in areas where structural strength and integrity are required, fabrics manufactured by the older techniques cannot be used. Such uses include structural parts for high speed airplanes where the fabric is to be impregnated with a curable resin system.
In the modern usages referred to, the traditional knitted or woven fabrics do not provide sufficient strength, even when impregnated with a curable resin system, following cure, to provide the necessary uniformity and strength. Accordingly, non-woven fabrics have been developed for such utilization.
The non-woven fabrics which have been developed for these structural uses involve a series of layers which are laid down, generally in a continuously formed fabric, and with at least the final width of the fabric during formation, the layers ultimately being held together by stitching through the layers, knitting with a loose stitch through the layers, or adhesively bonding threads of the layers at crossing points. The composition of the stitching material or of the adhesive material is not of critical importance, so long as the material has sufficient strength to hold the various layers together up to the time of resin impregnation, since the final strength of the part formed and the holding of the various yarns of the fabric in their proper position is accomplished by the cured resin.
The most desirable of the non-woven fabrics for structural purposes has been found to be those with at least two layers, the yarns of which are at an angle of approximately 45° to the long axis of the fabric direction, the two layers lying at 90° to each other. There can be more than two layers of yarns, depending upon the end use to which the fabric is to be put and either the first two layers, or any successive layers, can be placed at angles varying from 30° to 150° to the long axis of the fabric. If desired, a series of warp threads, lying parallel to the long axis of the fabric, a series of weft threads, lying at approximately 90° to the long axis of the fabric, or both, can be included. Once all of the fabric layers have been placed, the fabric is held together for storage, shipment, and ultimate impregnation, by one of the referenced methods, i.e., stitching, loose weave knitting, or adhesive bonding.
Among patents showing the formation of similar types of fabric are Eaton, U.S. Pat. No. 3,607,565; Smith, U.S. Pat. No. 3,765,893; and Campman et al U.S. Pat. No. 4,325,999.
The Campman et al patent particularly describes a number of methods for forming bias laid, non-woven fabrics, as generally referred to in the present patent application. However, as will be observed from a review of Campman et al, successive courses of each set of yarns there are laid in a pattern such that each course is angled at 90° to the previous course. For purposes of this invention, a course is defined as the plurality of yarns laid together in traversing the distance from one side of the fabric being formed to the opposite side; when the plurality of yarns reverses directions, and returns from the second side to the first side, that is a second course.
In Campman et al, prior to the reversal of direction of the yarns, so as to lay a second course, the yarns are wrapped around a series of pins, the number of pins corresponding to the number of yarns being laid. When the plurality of yarns is returned to the first side of the forming fabric, the yarns are wrapped about a set of pins formed on the conveyor on the first side, and, again, direction reversed by 90° so as to be returned to the second side for a fourth course. Campman et al do show one embodiment in which the courses of yarns formed by a single set of moving yarns are parallel to each other. That is, essentially, shown in FIG. 10 of the Campman et al patent, and the portion of the disclosure relating to that figure. However, a relatively complex mechanism is necessary to accomplish this parallelism between courses, the complex mechanism including two sets of pins on each side of the fabric being formed to allow the second, or return course, to be parallel to the first. None of the other automatic types of bias fabric formation machinery known to applicant provides even a mechanism of this complexity for forming parallel courses, except for applicant's patent, referred to below.
The inability to provide parallel courses results, in many instances, in a diminution of strength of the structural member being formed from these bias laid, non-woven fabrics. Further, because there is a waste of yarn due to the 90° return angle, which causes the second course to partially overlie the first course, the expense of the bias laid, non-woven fabric is greater than it would be if parallel courses were possible.
In my prior U.S. Pat. No. 4,556,440, a method and apparatus are shown for forming bias laid, non-woven fabrics, in parallel based, in part, on the speed of the yarn carrying means being diminished near the ends of its travel and possible movement of those means in a direction opposite the direction of fabric travel at a point where the yarns being conveyed are to be placed onto or between the needles of the continous conveyors. That patent also describes the possibility of some overlap of a returning course over a course already laid from the same group of yarns. However, as that patent stated, when such an overlap is created, there is also a slight angle between the course first laid and the return course.
In Klaeui, U.S. Pat. No. 3,564,872, an apparatus and process for laying parallel courses of yarn is also taught, employing a rake. However, the disclosure of the Klaeui patent is limited to yarns laid at a 90° angle to the direction of movement of the conveyors; there is no provision for an overlapping of a return course, the courses in Klaeui being laid adjacent each other; and all of the operating systems, including the conveyors, the yarn carriers, and the rakes, are driven from the same system of gears and pulleys, so that no variation is possible between the various operating systems, once a machine is constructed.
Further, Klaeui does not teach the possibility of impaling the yarns on either the rake or on the means formed on the conveyors for holding the yarns.
The prior art has not shown a process or apparatus which allows fully parallel courses of bias laid, non-woven fabrics to be placed on moving conveyors where partial overlapping of return courses is provided for and where the yarns being laid onto the conveyor can be either placed between holding means, such as needles, or impaled on them. Because of the greater control of strength and uniformity provided by either or both of these steps, such apparatus and process have been ardently sought.
BRIEF DESCRIPTION OF THE INVENTION
In accordance with the present invention, it has unexpectedly been discovered that if a rake mechanism, synchronized with, but driven separately from, the conveyors, yarn carrying means, and bonding mechanism, is associated with the needles formed on the conveyors, greater assurance of parallelism of the yarns is achieved. Further, employing this rake mechanism, successive courses of yarn can overlie a portion of an already laid course so as to better control the strength and thickness of the resulting layer, the overlying portions being parallel to the first courses. As with the invention set forth in my prior patent, it is not important whether the individual yarns fall between the needles or are impaled on the needles, and that is true with regard to both the needles of the conveyor and the needles of the rake system.
Preferably, the needles on the rake system are formed at an angle to correspond to and supplement the angle of the approaching yarns being fed by the yarn carrying means, at each end of the travel limits of the yarn carrying means. Thus, for example, if the yarn carrying means is angled at 45° to the angle of travel of the fabric being formed, then the needles of the rake mechanism beyond one of the conveyors is formed at 45° and the needles of the rake mechanism beyond the opposite conveyor are formed at 135°. Similarly, when the yarn carrying means is at an angle of 30°, then the needles of the rake mechanism beyond the first conveyor are at an angle of 30°, while the needles on the rake mechanism beyond the opposite conveyor are at an angle of 150°. The rakes, themselves, to which the needles are attached, are always parallel to the belt conveyor system.
The purpose of the rake mechanism is to accept and retain the yarns being carried by the yarn carrying means at either end of the extremities of travel of the yarn carrying means. Thus, the yarns being carried by the yarn carrying means are accepted between the needles of the rake mechanism on the appropriate side of the fabric forming apparatus, either by being placed between adjacent needles, or by being impaled by one of the needles. The rake mechanism, through a movement opposed to the direction of travel of the conveyors on the fabric forming mechanism, and in conjuction with the return travel of the yarn carrying means, places the yarns onto or between the appropriate needles on the conveyors of the fabric forming mechanism. Again, the yarns can be placed between adjacent needles on the conveyors, or can be impaled on those needles. As explained in my prior patent, the impaling of yarns on the needles frequently provides for a more uniform product.
In order to make certain that the yarns are appropriately held within or on the needles of the rake mechanism, when the yarn carrying means is travelling in, essentially, the same direction as the fabric forming mechanism, the rakes must first be moved a slight distance in the same direction as the conveyors, whereby the yarns are trapped by the rake mechanism, and then the rake mechanism will move backward, against the direction of travel of the conveyor, in order to release the yarns to the conveyor needles. When the direction of travel of the yarn carrying means is, essentially, against the direction of travel of the fabric forming mechanism, this double motion of the rake mechanism is not required, and the rake mechanism need merely move opposite the direction of travel of the fabric forming mechanism. When the rakes are moved a slight distance in the same direction as the conveyors, the movement is sufficient to place the yarns over the needles of the rake, generally a movement of at least one needle space, and preferably two or three needles spaces. The amount of movement of the rake in this additional direction does tend to vary with the thickness of the yarn being employed.
Two different modes of operation are possible for the rake mechanism. In its travel opposite the direction of movement of the fabric forming mechanism, the rake system may either move a distance which is the same as the width of the yarns being carried by the yarn carrying means, i.e., a full course, or may move a distance equivalent to only a portion of the width of the yarns, i.e., a fraction of a full course. When only a fraction of a complete course is traversed by the rake mechanism, obviously, there is some overlap of the return course onto the course first laid. The desired width of this overlap is determined, not by the construction of the apparatus or any limitation on the process, but rather by the requirements of the use to which the ultimately formed fabric is to be put. Obviously, the less the amount of travel of the rake system, the greater will be the overlap of successive courses, and the denser will be the fabric formed; conversely, when the rake system travels a substantial percentage of the width of a course, there will be relatively little overlap of successive courses, and a lesser density of that layer in the finally formed fabric.
Because of the use of the rake system, particularly when used in conjunction with the slowing of the movement of the yarn carrying means near the extremities of travel, as set forth in my prior patent, complete parallelism within each layer is attained, with or without overlap. When there is overlap, the overlapped portions are parallel with the yarns of the first course, unlike the fabric construction set forth in my prior patent.
While my prior patent set forth the possibility of a movement of the yarn carrying means in a direction opposite that of the travel of the fabric forming mechanism, in addition to movement of the carrier back and forth between the conveyor, that is not required in accordance with the present invention to achieve parallelism of successive courses. It may be used as an additional means of achieving parallelism in accordance with the present invention, but is not required.
While the disclosure of the present invention primarily describes the use of a sewing machine to bind together the various layers of a bias laid, non-woven fabric, it will be appreciated that other methods of bonding the layers to each other can be employed, including knitting, adhesive application, etc.
In accordance with the present invention, the apparatus for stitching the various layers of the bias laid, non-woven fabric together can be any of the machines presently employed in the textile industry for such a purpose. For example, the machine presently sold by Liba Maschinenfabrik GmbH of West Germany, under the designation Copcentra-HS, is suitable for formation of fabrics in accordance with the present invention. Both because this machine is known to the trade, and because the present invention does not include, as novel subject matter, the method of stitching the various layers together, this specification will not include a detailed description of the sewing mechanism. The Liba Copcentra-HS machine is provided, in its operative gearing, with an oscillating crank mechanism. Because of the inherent nature of the operation of such a crank, the oscillating drive shaft controlled by the mechanism moves more slowly before its direction is reversed. By keying the movement of the yarn carrying means to this oscillating drive shaft, movement of the yarn carrying means is slowed at the end of each course, which allows the conveyor mechanisms to move relatively further forward than would otherwise be true, and aid in gaining parallelism of the various courses. The operation and construction of this portion of the Copcentra-HS machine is fully set forth in my prior patent, U.S. Pat. No. 4,556,440, and that portion of that patent is herein incorporated by reference.
In accordance with the present invention, a pair of parallel conveyors is formed, the front supports of the conveyors being at the head of a bonding mechanism, such as a Liba Copcentra-HS stitching machine. Each conveyor carries a series of equidistantly spaced needles which extend outwardly from the space between the conveyors. The fabric to be formed is placed on these conveyors and, more particularly, the individual yarns are placed around or on the individual needles. In general terms, each conveyor is comprised of an endless chain to which are attached members on which the individual needles are formed, the members, on the operating portion of the conveyor belt, forming a continuous, moving bar. The drive mechanism for the conveyors is independent of the drive mechanism for the yarn carriers, at least in the sense that the conveyors are moved at a constant speed.
Yarn carriers move back and forth between the moving conveyors. Each yarn carrier carries a plurality of individual, equally spaced yarns. The yarn carriers are caused to move beyond each conveyor and its associated rake system, as the yarn carrier passes beyond the rake system, it moves downwardly, so as to place the individual yarns which are carried around the needles on the rake system, or to cause the needle on the rake system to impale one of the yarns. Thus, it will be recognized that the number of yarns in a given linear dimension need not equal the number of needles in the same linear dimension. When number of yarns in a given linear dimension is greater than the number of needles in the same linear dimension, some of the yarns will be impaled by the needles, providing for a more uniform coverage. In this way, the density of each layer can be controlled, as desired.
The number of yarn carriers employed, and thus the number of individual layers, is determined by the end use of the bias laid, non-woven fabric being produced. The angle at which the yarn carriers place the courses of yarn on the moving conveyors is, likewise, determined by the end use to which the final fabric is to be put. While for many uses, angles of 45° to the long axis of the fabric, for each of two courses, is preferred, it will be apparent that other angular settings can be employed and that more than two layers can be placed on the moving conveyors. Generally, the bias laid layers are at angles of between 30° and 150° to the long axis of the fabric. In addition to the bias laid layers, however, a warp layer can be included in the fabric being formed, the yarns in the warp layer being placed in the standard manner essentially parallel to the moving conveyors. Similarly, one of the yarn carriers can be angled so as to place a weft layer onto the fabric being formed, the angle of the weft layer being the standard, essentially 90°, to the long axis of the fabric.
As previously indicated, the two conveyors move at a constant speed toward the bonding mechanism where the fabric layers are bound together. The yarn carrying means, while moving at a generally constant speed across the fabric being laid, can be slowed down in their travel across the fabric at the end of each course. Because the movement of the yarn carrier can be keyed to an oscillating crank mechanism, and because that crank mechanism slows down near the end of each stroke, movement of the yarn carrying mechanism is also slowed near the end of the stroke, which is keyed to correspond with the end of the course.
Thus, the present invention provides for the formation of bias laid fabrics where all of the yarns in a given layer are parallel to each other. The parallelism in a given layer is achieved without complex machinery. Further, because the number of yarns need not equal the number of needles over a given linear dimension, greater density and uniformity are provided. Use can be made of the mechanism of the bonding portion of the apparatus to aid in the laying of the yarns so as to achieve these advantages.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings:
FIG. 1 is a plan view of one preferred form of bias fabric in accordance with the present invention;
FIG. 2 is a plan view of a second form of bias fabric in accordance with the present invention;
FIG. 3 is a perspective view, partly representational, showing the mechanism for placing the bias laid yarns on the conveyors;
FIG. 4 is a top plan view showing the conveyor, conveyor needles, rake system, and yarn carrier in accordance with the present invention along the line 4--4 of FIG. 3;
FIG. 5 is a sectional view showing a single needle of the conveyor system and a single needle of the rake system, with the yarn carrier beyond, and below, the rake system; and
FIG. 6 is a sectional view along the line 6--6 of FIG. 4.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the drawings, FIG. 1 illustrates a layer of yarns laid with the process and apparatus of the present invention, including a first course C and a second course C'. As will be apparent, each of the courses is laid at an angle of approximately 45° to the direction of the fabric forming mechanism shown by the arrow A. The apparatus and process of the present invention are so adjusted in forming the fabric of FIG. 1, that course C' is laid adjacent course C, without any overlap; however, as will be apparent, the two courses are parallel to each other.
In FIG. 2, a fabric is formed in accordance with a second embodiment of the present invention where the process and apparatus are adjusted to provide for an overlap of yarns in successive courses. Thus, with a fabric forming direction illustrated with the arrow B, a first yarn course D is laid at approximately a 45° angle to the fabric forming mechanism. A second course D' is then laid parallel to course D, and overlying approximately one-half of the width of course D. It will be appreciated that FIG. 2 is merely one illustration of the amount of overlap which can be achieved employing the process and apparatus of the present invention, more or less overlap being possible and being dictated by the requirements of the finished fabric.
An overview of the placement of the bias laid yarns in accordance with the present invention is shown in FIG. 3. The system is similar to that described in my U.S. Pat. No. 4,556,440. Two endless conveyors 30 and 31 are shown, respectively, on the left and right hand sides. These conveyors 30 and 31, which are of the same length, are driven at the same speed by forward pulleys 32 and 33 and are suspended on rearward pulleys 34 and 35. Forward pulleys 32 and 33 are connected by axial member 36, while rearward pulleys 34 and 35 are connected by axial member 37. Each conveyor includes a plurality of blocks 40. Formed onto, or from, each block are a series of sharp needles 42 best illustrated in FIG. 4.
Formed across, but slightly above, the conveyors 30 and 31 are a plurality of guide arms 50, 51, 52. Three such arms are illustrated for laying of three layers of yarn, but it will be appreciated that additional guide arms and complete yarn laying assemblies can be provided, depending upon the number of layers of yarn to be incorporated into the bias laid fabric. Similarly, the number of such guide arms can be reduced to two. Moving along each of the guide arms is a member 53 to which is attached a yarn carrier 54, each yarn carrier being employed for laying a plurality of yarns 55. It will be appreciated, from a review of FIG. 3, that regardless of the angling of the guide arms 50, 51, 52, the yarn carrier 54 is placed in a direction parallel to the movement of the conveyors 30, 31.
As illustrated in my prior patent, U.S. Pat. No. 4,556,440, the yarn carriers are mounted in a slot so that they dip down below the level of the needles 42, and similar needles formed on the rake systems, to be described, in order to allow the yarns 55 being carried to be caught in the rake system at either end of the travel of the carriers 54. As also set forth in that patent, each of the carriers 54 may be mounted on a pneumatic cylinder attached to a source of air or other gas under pressure to allow movement of the carrier 54 rearwardly as the yarns are caught on the rake system.
While not illustrated, a device having means to hold the individual yarns in the fabric 60 together is placed at the end of the mechanism illustrated in FIG. 3, just before the pulleys 32, 33. This device can be a stitching machine; such as the previously described Liba Copcentr-HS, can be a different type of stitching machine, a knitting machine, or a device which applies an adhesive at selected points along the fabric length and width in order to hold the yarns together, prior to impregnation.
Through a driving means the yarn carriers are moved back and forth across the short axis of the fabric being formed. Either the bonding mechanism contains a driving means, such as an oscillating crank mechanism, which causes the speed of the yarn carrier to be reduced near the end of its travel, or such an oscillating crank mechanism can be provided, separate and apart from the bonding unit, in order to accomplish the same results. While the slowing down of the carriers 54 near the end of travel, beyond the conveyors, can be omitted when the rake system is employed, this slowing down is an aid to attaining parallelism of the yarns, even with the rake system.
In addition to being slowed down by this mechanism at either end of its travel, it is necessary to cause the yarn carrier to drop down below the level of the needles 42, when the carrier has passed beyond those needles and the associated conveyor. This dropping down is required in order to allow the yarns to be wrapped around the needles, or to be impaled by them. This is accomplished by mounting the yarn carrier on a guide pin which travels in a horizontal slot in a guide arm, that slot being angled downwardly beyond the conveyor and the rake system, so as to cam the yarn carrier downwardly, and move the yarns below the horizontal level of the needles. On the return stroke, the yarn carrier moves upwardly, completing the operation of wrapping the yarns around the needles, or impaling them; and then returns across the fabric being formed.
The particular improvement of the present invention involves the rake systems illustrated, on the left hand side of the machine, as numbers 70, 71, and 72 and, on the right side of the machine, as 80, 81, and 82. While the general structure of each of these rake mechanisms, and their method of operation, is the same, there are some variations, as will be detailed below. The rake systems and their operation are best illustrated in FIGS. 4, 5, and 6.
As illustrated in FIGS. 3 and 4, the conveyors 30 and 31 have a number of blocks 40 formed on an endless chain. Extending from each of the blocks 40 are sharp needles 42 which are spaced equidistantly. As best seen in FIG. 4, the needles extend at, essentially, right angles to the blocks 40 and conveyor 31. As best illustrated in FIG. 5, the needles 42 are angled slightly upwardly from the blocks 40. This slight angling upwardly is provided to allow grabbing of the threads and proper interaction of the needles 42 with the rake systems 70, 71, 72, 80, 81, and 82, and the carriers 54. The amount of angling should be from 10° to 40°, preferably from 20° to 30°.
The rake system illustrated in FIG. 4 is, essentially, the one shown in FIG. 3 as 80. While the guide member 50 is, essentially, at a 45° angle to the conveyor 31, the carrier 54 is, essentially, parallel to that conveyor. The needles 100 formed on rake 80 are at approximately a 45° (135°) angle so as to supplement the angle of the guide member 50 and provide the proper interaction with the yarns being carried by the carrier 54. The angling of the needles 100 on the rake system should correspond, roughly, to the supplement of the angle of the particular guide member in association with which they are used. Thus, if the guide member is at 30°, the needles on the rake system should be at 150°; if the guide member is at 45°, the needles on the rake system should be at 135°; if the guide member is at 60°, the needles on the rake system should be at 120°; if the guide member is at 90° to the direction of travel of the fabric being formed, the needles 100 on the rake system should be at 90°. It has been found, however, that the 45° rake system can be employed with both the 30° and 60° guide members.
As best illustrated in FIG. 5, the needles 100 on the rake system have an essentially vertical portion 101, extending upwardly from the rake system 80, and are then bent over at 102, so that the point of the needle 103, is angled downwardly. Generally, the angle E between the upstanding vertical portion 101 and the portion of needle 100 on which the point 103 is formed is the same as the angle F between the needle 42 and the block 40. The angle E may be greater than the angle F, but the point 103 must lie below the needle 42. Preferably, the angle E is approximately 55°. This is to prevent the yarn from escaping from the rake as the carrier is raised, and then travels back across the conveyor system. The alignment, bending, and angling of the needles 100 from the rake system 80 is best illustrated in FIG. 6. It will be appreciated, as just described, that the angling of the needles 100 on the rake system 82 will be exactly opposite that shown in FIGS. 4 and 6, and the angling of the needles 100 on the rake systems 71 and 81 will be at essentially right angles to the rake systems 71 and 81 and, therefore, at, essentially, right angles to the conveyors 30 and 31. The angling of the needles on the rake system 70 will be essentially the same as those on the rake system 82, while the angling of the needles on the rake system 72 will be essentially the same as those on the rake system 80.
In operation, and referring, particularly, to the rake system 80 of FIG. 4, as the conveyor 31 moves in the direction indicated by the arrow G, and the carrier 54 moves in the direction indicated by the arrow H, the yarns 55 are moved to a point beyond the rake system 80 and below the points 103 of the needles, as best illustrated in FIG. 5. The rake system 80 then moves in the direction indicated by the arrow I in FIG. 4 so as to firmly grasp the yarns 55 which are in the vicinity of the needles 100 formed on the rake system 80. As previously indicated, the individual yarns 55 may either fall between adjacent needles 100, or may be impaled on an individual needle 100. Obviously, with certain types of yarns, such as carbon fibers, the sizing and spacing of the yarns 55 and the carrier 54 would be such that none of these yarns would be impaled.
As the carrier 54 is raised upwardly, away from the rake system 80, it begins to move in a direction opposite the arrow H and, because of the tension in the yarns, pulls the yarns off of the rake needles and places them, firmly, on the needles 42 formed on the conveyor 31, as illustrated by the yarn 55' in FIG. 4.
When the conveyor 54 has completed its travel across the fabric being formed, to the opposite conveyor 30, the process is repeated, with one exception. In returning across the fabric being formed to the conveyor 30, the yarns are beyond, and below, rake system 70, when the conveyor 54 dips down. In order to assure retention of the yarns 55 in the needles 100 of the rake system 70, the rake system 70 must first move slightly forward, i.e., in the same direction as the conveyor 30 is travelling, before it is moved rearwardly for depositing of the yarns 55 on and within the needles 42 of the conveyor 30. Only a slight movement of the rake 70 in a forward direction, i.e., a distance sufficient to place the yarn over the needles 42 formed on the conveyors 30 and 31. Generally, the forward movement of the rake system 70 is approximately the distance between two of the needles 100, preferably the distance between two to three of the needles 100. The amount of movement required tends to vary with the thickness of the yarn.
The operation of the rake systems 71 and 81, and of the rake system 72 is the same as that described for the rake system 80. This is because the carrier 54 is moving either at right angles, or in a direction opposite the direction of travel of the fabric being formed. The operation of the rake system 82 is the same as that of the rake system 70, since the carrier 54, at that point, is moving in the same direction as the direction of travel of the fabric being formed.
While the means for moving the various rake systems are not illustrated, any convenient means can be employed. Thus, the rakes may be moved pneumatically, mechanically, or by a solenoid movement.
As previously indicated, the density of the fabric can be controlled by overlapping of return courses on first courses. This is accomplished without loss of parallelism. Further, this increased density is accomplished without requiring too high a concentration of yarns in each carrier, a situation which could lead to difficulty in operation of the mechanism. Without the rake systems of the present invention, this overlapping with paralellism could not be accomplished. The amount of overlap accomplished is, generally, based upon the width of the yarns 55 in the carrier. Obviously, this width has nothing to do with the denier of the yarns, but rather refers to the dimension W shown in FIG. 3. As this width increases, with the same travel of the rake system, there is a greater overlap of yarns, while as the width W is decreased, with the same movement of the rake system, there is less of an overlap of yarns.
The amount of movement of the rake systems 70, 71, 72, 80, 81, and 82, and of the carriers 54, in a direction opposite the direction of fabric formation is dependent upon the speed of the conveyor. The speed of the conveyor is dependent upon the number of stitches per inch being placed by the needling machine, when one is used, i.e., the fewer the number of stitches, the faster can be the fabric formation.
As indicated in my prior patent, the number of yarns in the carrier 54 need not correspond to the spacing of the needles 42 formed on the conveyors. Similarly, the number of yarns in the carrier 54 need not correspond to the number of needles 100 on the rake system in the same linear dimension, nor do the number of needles 100 in the rake system have to correspond with the number of needles 42 on the conveyor in the same linear dimension. As previously indicated, the ability to impale some yarns aids in control of density uniformity.
As indicated, the fabric formed in accordance with the present process is generally used in the formation of structural parts, as in airplanes, and in such a use is wrapped around a mold, or laid into a particular position, after which, or prior to, being impregnated with a resin. When the fabric is fully in place and impregnated, the resin is cured to complete formation of the part.
While the description of the present invention has involved a stitching of the various fabric layers together, it will be appreciated that other methods for holding the non-woven fabric in place can be employed. For example, a loose knitting operation, as is known in the art can be employed. Further, a light resin spray can be applied to bond the fibers at their crossing points. Again, the material which is employed for this bonding, or the materials used, are not of critical importance, as the ultimate strength of the bias laid non-woven fabric comes from the resin which is finally used for impregnation and which is cured with the fabric in place. If the bonding mechanism used for the fabric does not have a device, such as the oscillating crank of the Liba Copcentra-HS, then such a mechanism can be independently provided for driving of the yarn carriers in order to provide for their reduced speed of motion near the ends of the travel paths.
No mention has yet been made in this specification of the loops which are obviously formed, either by the yarns wrapping around the various needles or by being impaled on them. As is apparent, these loops are at the extremities of the width of the fabric being formed. After stitching or other methods of bonding, so that the fabric is generally held together, the loops can be cut away by any known mechanism. Once the other bonding means have been put into place, the loops, which had served only the function of holding the fabric in place up until that time, are no longer required.
While the invention has been illustrated and described in accordance with the particular embodiments, it will be apparent to those skilled in the art that variations are possible within the spirit and scope of the invention. Accordingly, the invention is not to be considered as limited except as set forth in the appended claims. | Non-woven, bias laid fabrics, where the various fabric layers are held together by external means, such as stitching, and wherein, preferably, at least two of the layers are formed at an angle of from 30° to 150° relative to the long axis of the fabric, are formed by directing at least two pluralities of yarns back and forth across the width of the forming fabric, to be wrapped around or mounted on a series of needles formed on a moving conveyor, one conveyor being placed on either side and moving in the direction of the long axis of the fabric. Speed of movement of the yarns can be determined by the speed of movement of the mechanism for the machine operated to hold the various fabric layers together; preferably said machine mechanism moves more slowly near the ends of each cycle, so that yarn carriers are similarly slowed at either end of the forming fabric width, aiding in making successive courses of yarn lie parallel to each other without the necessity for extra equipment. A second series of needles is provided beyond each moving conveyor, in association with each plurality of yarns being directed back and forth across the width of the forming fabric, to accept the plurality of yarns and place them onto or into the needles on the moving conveyor, the additional series of needles providing for parallelism in each plurality of yarns, with or without overlap of each plurality of yarns. | big_patent |
FIELD OF THE INVENTION
The present invention relates to weft insertion in a multiple-color air jet loom, and more particularly to a method of and an apparatus for inserting a selected weft thread with a weft carrying force appropriate for the selected weft thread.
BACKGROUND OF THE INVENTION
Multiple-color air jet looms have a plurality of different kinds of weft threads in readiness for weft insertion and successively insert them, one at a time, through warp sheds according to a fabric to be woven on the loom. Such different weft threads typically vary in thickness. They are subjected to slightly different resistances to being drawn for weft insertion and are slightly differently carried on jets of air.
In prior multiple-color air jet looms, however, air under uniform pressure is ejected from groups of main nozzles and subnozzles irrespectively of the kind of selected weft thread to be inserted. This means that the weft carrying force remains constant at all times for different weft threads, and that the speed at which the weft threads are taken through the warp sheds varies from one weft type to another. For alternately inserting thin and thick weft threads, for instance, the pressure of air jets is preselected and fixed to meet the thick weft thread which requires a greater weft carrying force. Therefore, a certain amount of air under pressure is wasted when inserting the thinner weft threads.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a method and an apparatus for inserting different weft threads in and through warp sheds in a multiple-color air jet loom, in which air under pressure is ejected from a main nozzle unit or a main nozzle unit and subnozzles to produce different weft carrying forces suited respectively for the different weft threads for thereby carrying the weft threads, one at a time, through the warp shed at the same speed under stable conditions and preventing undue consumption of pressurized air.
According to the present invention, the foregoing object can be achieved by ejecting the air from the main nozzle unit or the main nozzle unit and subnozzles under different pressures preset respectively to produce the weft carrying forces for carrying the weft threads, or supplying air under pressure from the main nozzle unit or the main nozzle unit and subnozzles for different intervals of time selected respectively for the weft threads to produce the weft carrying forces. To eject the air under different pressures, the subnozzles are divided into groups along the warp shed and spaced at different intervals for the groups to produce combined air streams of varying pressures, or an air pressure control means is connected between a source of air under pressure and the main nozzle and subnozzles for supplying the air under different pressures to the main nozzle and subnozzles. To eject the air under pressure for different intervals of time, a valve means is connected between the source of air under pressure and the main nozzle and subnozzles, and a control means is actuated in synchronism with operation of the air jet loom for opening the valve means selectively for the intervals of time. With this arrangement, the weft threads can be inserted and carried through the warp shed under stable conditions in a constant period of time, and undue consumption of air under pressure is avoided.
The above and other objects, features and advantages of the present invention will become more apparent from the following description when taken in conjunction with the accompanying drawings in which preferred embodiments of the present invention are shown by way of illustrative example.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of a pneumatic piping system in a weft insertion apparatus according to a first embodiment of the present invention;
FIG. 2 is a schematic view of a pneumatic piping system in a weft insertion apparatus according to a second embodiment of the present invention;
FIG. 3 is a schematic view of a pneumatic piping system in a weft insertion apparatus according to a third embodiment of the present invention;
FIG. 4 is a schematic view of a pneumatic piping system in a weft insertion apparatus according to a fourth embodiment of the present invention;
FIG. 5 is a block diagram of a control system for the weft insertion apparatus of the fourth embodiment;
FIG. 6 is a schematic view of a pneumatic piping system in a weft insertion apparatus according to a fifth embodiment of the present invention;
FIG. 7 is a schematic view of a pneumatic piping system in a weft insertion apparatus according to a seventh embodiment of the present invention; and
FIG. 8 is a block diagram of a control system for the weft insertion apparatus of the sixth embodiment.
DETAILED DESCRIPTION
Like or corresponding parts are denoted by like or corresponding reference characters throughout several views.
1st embodiment (FIG. 1):
FIG. 1 shows a pneumatic piping system in a weft insertion apparatus 1 according to a first embodiment of the present invention, the pneumatic piping system including subnozzles divided into different groups for producing different additional weft carrying forces to be applied in warp sheds. The weft insertion apparatus 1 shown is incorporated in an air jet loom in which two different weft threads are employed for insertion. The weft insertion apparatus 1 includes a source 2 of air under pressure for inserting the weft threads. The source 2 is connected through a pipe 18 to a regulator 7 and a subtank 8 which is coupled through a plurality, three for example, of on-off valves 9 to dedicated subnozzles 11 and common subnozzles 12 which constitute a subnozzle group I, and also through a plurality, three for example, of on-off valves 10 to the common subnozzles 12 and dedicated subnozzles 13 which constitute a subnozzle group II. The on-off valves 9, 10 are connected to the common subnozzles 12 through check valves 14.
A main nozzle unit 6 is positioned alongside of a warp shed and composed of two main nozzles respectively for two different weft threads 3a, 3b, the weft thread 3a being thicker than the weft thread 3b, for example. The main nozzle assembly 6 is movable to one, at a time, of two selected positions dependent on a selected one of the weft threads 3a, 3b for inserting the selected weft thread through the warp shed. The weft threads 3a, 3b are unreeled from weft supplies 4a, 4b, respectively, and supplied through yarn guides 5a, 5b to the main nozzle unit 6 by a weft thread storage unit and a weft thread selector (both not shown) according to the weft insertion sequence dictated by a fabric to be woven on the air jet loom.
The subnozzles 11, 12, 13 are arranged along the warp shed. The subnozzles 11, 12, which constitute the subnozzle group I, are spaced at intervals or pitches smaller than those at which the subnozzles 12, 13 constituting the subnozzle group II are spaced. These subnozzles 11, 12, 13 are individually capable of producing the same weft carrying force. Accordingly, provided the on-off valves 9, 10 remain open for the same interval of time for air supply, the subnozzle group I can produce a larger weft carrying force than that the subnozzle group II can produce.
Operation of the weft insertion apparatus thus constructed is as follows: The source 2 supplies air 15 to the subtank 8 under a low pressure determined by the regulator 7. Upon weft insertion, either the on-off valves 9 or the on-off valves 10 are opened for a prescribed period of time to allow passage therethrough of the air 15 under a reduced pressure toward the corresponding subnozzles 11, 12 or subnozzles 12, 13. The on-off valves 9, 10 are controlled by weft selection signals A, B supplied from a control unit. When the thicker weft thread 3a is to be inserted by the main nozzle unit 6, a larger weft carrying force is required. Therefore, the on-off valves 9 are opened by the weft selection signal A to pass the air 15 under a pressure appropriate for the thicker weft thread 3a, whereupon the subnozzles 11, 12 in the subnozzle group I eject the pressurized air 15 to produce a combined stronger air stream necessary for carrying the thicker weft thread 3a. For inserting the thinner weft thread 3b from the main nozzle unit 6, the on-off valves 10 are opened by the weft selection signal B to enable the subnozzles 12, 13 to emit the air 15 under a pressure sufficient to produce a combined weaker air stream necessary to carry the thinner weft thread 3b. Therefore, the subnozzles 11, 12, 13 are selectively operated dependent on the weft thread 3a or 3b to be inserted for carrying the selected weft thread with a weft carrying force suitable for that weft thread.
The different weft carrying forces may be produced not only by the differently spaced subnozzle groups I, II, but also by positioning one of the subnozzle groups I, II more remotely from the warp shed than the other group, changing the effective cross-sectional area of each nozzle orifice in one of the subnozzle groups I, II, supplying air under different pressures to the subnozzle groups I, II, ejecting air streams from the subnozzle groups I, II at different angles to the warp shed, or varying the intervals of time in which air is ejected from the subnozzle groups I, II.
The weft carrying forces, which are described in each embodiment, may be produced by varying the interval of time in which air is ejected or by varying air ejecting forces. The air ejecting forces are produced by a selective combination of different pitches of subnozzles, different effective cross-sectional areas of nozzle orifices of the subnozzles, different distances of the nozzles from the warp shed, different angles at which the subnozzles are directed to the warp shed, and different pressure under which air is supplied to the subnozzles.
The on-off valves 9, 10 may be selectively actuated by a mechanical cam device operable in synchronism with the rotation of a main shaft of the loom. For example, for selectively inserting two thicker weft threads of cotton and one strong thinner weft thread for weaving corduroy, such a mechanical cam device may comprise a control cam mounted on a valve control shaft which makes one third of a full rotation thereof when the main shaft of the loom makes one complete revolution, so that the subnozzles 11, 12 will be actuated for inserting one of the thicker weft threads and the subnozzles 12, 13 will be actuated for inserting the thinner weft thread.
With the foregoing arrangement, various kinds of weft threads can be stably inserted through warp sheds since weft carrying forces are available which are suited for the respective different weft threads. When inserting thinner weft threads that can be taken through warp sheds with small forces, the air 15 under pressure is effectively utilized without wastefull consumption.
2nd embodiment (FIG. 2):
According to the embodiment shown in FIG. 2, different weft carrying forces are produced in warp sheds by providing subnozzles having different orifice diameters or supplying air under different pressures to the subnozzles. There are no common nozzles such as those shown at 12 in FIG. 1, and pairs of subnozzles 11, 13 are arrayed at equal intervals or pitches, the subnozzles 11 or 13 being spaced at equal intervals. The groups of subnozzles 11, 13 are capable of producing different weft carrying forces. More specifically, the subnozzles 11 have nozzle orifices of an effective cross-sectional area larger than that of the nozzle orifices of the subnozzles 13. Provided the air 15 is supplied under the same pressure to the subnozzles 11, 13, therefore, the subnozzles 11 can exert a greater weft carrying force than the subnozzles 13. The weft insertion apparatus also includes a pair of regulators 7a, 7b and a pair of subtanks 8a, 8b connected respectively thereto. The subtank 8a is connected through the on-off valves 9 to the subnozzles 11, while the subtank 8b is connected through the on-off valves 10 to the subnozzles 13. One of the regulators, 7a for example, has a greater pressure setting than that of the other regulator 7b. As a consequence, the subtanks 8a, 8b supply the air 15 under different pressures to the corresponding subnozzles 11, 13 for regulating the weft carrying forces produced by the subnozzles 11, 13.
3rd embodiment (FIG. 3):
The weft insertion apparatus shown in FIG. 3 has groups of subnozzles 11, 12, 13 that are arranged in a pattern identical to that of the subnozzles 11, 12, 13 shown in FIG. 1. The subtank 8 is connected to three on-off valves 16 which are respectively coupled to directional control valves 17, which in turn are selectably connectable to the subnozzle groups I, II. The on-off valves 16 are of the mechanical type and openable and closable for each pick. The directional control valves 17 are actuatable by the weft selection signals A, B to supply the air 15 under pressure through different paths selectively to the subnozzles 11, 12 or the subnozzles 12, 13.
4th embodiment (FIGS. 4 and 5):
According to the 4th embodiment, a weft inserting main nozzle 6 and weft carrying subnozzles 12 are selectively supplied with air 15 under different pressures.
FIG. 4 illustrates a pneumatic piping system for an air jet loom employing two different kinds of weft threads. A source 2 of pressurized air serves to supply air 15 under pressure for inserting and carrying weft threads, and is connected by a pipe 18 to a pair of regulators 19a, 19b and accumulator tanks 20a, 20b. The accumulator tanks 20a, 20b are coupled through a common directional control valve 21 and a common on-off valve 22 to the weft inserting main nozzle 6. The weft inserting main nozzle 6 has two weft passage holes 6a, 6b and a single common tube 6c connected thereto. A selected one of the weft threads 3a, 3b is fed through the weft passage hole 6a or 6b and the common tube 6c into the warp shed. The air source 2 is also connected through a pipe 18 to a pair of regulators 7a, 7b coupled respectively to a pair of subtanks 8a, 8b. The subtanks 8 a, 8b are connected via a common direction control valve 23 to a plurality, three for example, of on-off valves 24 connected to the grouped subnozzles 12. The subnozzles 12 are arrayed along the warp shed for ejecting air 15 under a pressure appropriate for the weft thread being inserted through the warp shed to assist the weft thread in being carried through the warp shed. The directional control valves 21, 23 are controlled by a weft selection signal C, and the on-off valves 22, 24 are controlled by on-off command signals D, E, respectively.
FIG. 5 shows an electric signal generator for generating the weft selection signal C and the on-off command signals D, E. The weft selection signal C is issued by a control means comprising a switching command unit 25, and the on-off command signals D, E are issued by a control means comprising an on-off command unit 26. The switching command unit 25 is connected to a sensor 27 which detects rotation of a weft insertion control cam 28 for energizing the switching command unit 25 at a time prior to weft insertion. The weft insertion control cam 28 is rotatable in synchronism with the operation of the loom. In the illustrated embodiment, since the two weft threads are alternately inserted, the cam 28 makes half of a full revolution thereof when the main shaft of the loom makes a complete revolution. The on-off command unit 26 is energized by a signal supplied as input information from an encoder 29 which electrically reads angular displacement of the main shaft of the loom and delivers angle in formation to the on-off command unit 26. The sensor 27 is also connected to an on-off program selector 30 that is supplied with information indicative of a weft insertion timing angle from a memory 31 serving to set a weft insertion timing for delivering selected timing information to the on-off command unit 26. The regulators 7a, 7b, 19a, 19b, the accumulator tanks 20a, 20b, the subtanks 8a, 8b, the directional control valves 21, 23, and the on-off valves 22, 24 jointly constitute a means for controlling the air 15 under pressure.
Operation of the weft insertion apparatus shown in FIGS. 4 and 5 will now be described. The air 15 under pressure from the source 2 is supplied to the regulators 19a, 19b by which the air pressure is reduced to a suitable degree, and the reduced air pressure is stored in the accumulator tanks 20a, 20b. The pressure in the accumulator tank 20a is selected to be low for the insertion of the thinner weft thread 3b. The pressure in the accumulator tank 20b is selected to be higher than that in the accumulator tank 20a for the insertion of the thicker weft thread 3a. Likewise, the air 15 under pressure is fed through the regulators 7a, 7b by which the air pressure is reduced to the subtanks 8a, 8b, respectively. The pressure in the subtank 8a is lower than that in the subtank 8b.
While the main shaft of the loom makes one complete revolution, the cam 28 makes half of its full revolution so that the output signal from the sensor 27 will be varied each time the cam 28 rotates 180 degrees. Each time the cam 28 rotates 180 degrees or the loom main shaft makes one revolution, the switching command unit 25 varies the level of the weft selection signal C to shift the directional control valves 21, 23 for supplying air 15 under a different pressure to the on-off valves 22, 24. In response to the information from the sensor 27, the on-off program selector 30 reads a stored on-off program, that is, weft insertion timing program from the memory 31, to deliver a displacement angle with its timing corresponding to the selected weft thread to the on-off command unit 26. The on-off command unit 26 compares the weft insertion timing angle as read from the memory 31 with an actual displacement angle of the loom shaft as detected by the encoder 29. When the compared angles coincide with each other, the on-off command unit 26 issues the on-off command signals D, E to the on-off valves 22, 24, respectively. The on-off valves 22, 24 are then opened to allow the air 15 under pressure to pass therethrough to the main nozzle 6 and the subnozzles 12 in timed relation to weft inserting and carrying operations.
Where the thicker weft thread 3a is to be inserted, the weft insertion main nozzle 6 ejects the air 15 under a higher pressure to force the weft thread 3a into the warp shed, and where the thinner weft thread 3b is to be inserted, the weft insertion main nozzle 6 ejects the air 15 under a lower pressure to drive the weft thread 3b into the warp shed. The subnozzles 12 eject the air 15 under a pressure selected to meet the selected weft thread for accelerating and carrying the weft thread through the warp shed with a suitable weft carrying force.
The weft carrying force may be regulated by varying the interval of time in which the air 15 under pressure is ejected. For example, the on-off command unit 26 generates the on-off command signals D, E for a longer interval of time when the thicker weft thread 3a is to be inserted, and generates the on-off command signals D, E for a shorter interval of time when the thinner weft thread 3b is to be inserted. The on-off valves 22, 24 are therefore open for different intervals of time dependent on the kind of weft thread to be inserted, for thereby exerting an appropriate weft carrying force to the selected weft thread.
With the embodiment shown in FIGS. 4 and 5, the nozzles are supplied with air having a pressure suitable for a weft thread to be inserted. Where a weft thread is to be inserted which requires no larger weft carrying force, no undue consumption of pressurized air is assured for reduced total air consumption under pressure. Furthermore, since the nozzles for inserting and carrying weft threads are supplied with pressurized air at suitable ejection timings for the selected weft threads, respectively, the occurrence of weft insertion failures becomes less frequent, resulting in stabilized weft insertion.
5th embodiment (FIG. 6):
According to the embodiment of FIG. 6, air pressure is regulated by a single remotely controlled pressure regulator valve 32 disposed in a pipe 18 connecting a subtank 8 to a plurality, three for example, of on-off valves 24. The pressure regulator valve 32 is responsive to switching command signals F1, F2, applied one at a time, for passing air 15 under a pressure appropriate for the kind of a weft thread selected for insertion. The arrangement of FIG. 6 is simpler because there are required no separate subtanks for respective air pressure settings. Although only the remotely controlled pressure regulator valve 32 for the subnozzles 12 is shown in FIG. 6, a similar pressure regulator valve may be provided in a piping system for the main nozzle 6 for weft insertion.
6th embodiment (FIGS. 7 and 8):
As shown in FIG. 7, a main nozzle unit 6 is composed of a pair of main nozzles. Air 15 is supplied from tanks 20a, 20b under different pressures to the main nozzle unit 6 under the control of respective on-off valves 22a, 22b. The pressurized air 15 is selectively fed to the main nozzle unit 6 dependent on the kind of a weft thread to be inserted, so that the main nozzle unit 6 will be shifted in position to bring one of the main nozzles into alignment with the warp shed for inserting the selected weft thread.
FIG. 8 shows an electric control system in which the on-off valves 22a, 22b are controlled respectively by two on-off command signals D1, D2 alternately issued by an on-off command unit 26 in synchronism with weft thread selection.
Although the air jet loom employing two different weft threads has been described in each embodiment, the present invention is applicable to air jet looms using more than two different weft threads. The subnozzles and the piping system connected thereto in the 1st through 3rd embodiments may replace the subnozzles and the piping system connected thereto in the 4th and 6th embodiments. Furthermore, the main nozzle and the piping system coupled thereto with the control system therefor in the 4th and 6th embodiments may be incorporated in a multiple-color air jet loom having no subnozzles. In the illustrated embodiments, pressurized air is ejected at the same time from the subnozzles, but it may alternatively be ejected sequentially from the successive groups of subnozzles.
Although certain preferred embodiments have been shown and described, it should be understood that many changes and modifications may be made therein without departing from the scope of the appended claims. | Multiple-color air jet looms successively insert different kinds of weft threads into warp sheds to weave a fabric of desired construction. The different weft threads are subjected to different resistances to their being drawn through a main nozzle and are carried on air jets under different conditions, so that the weft threads will be inserted unstably at different speeds. With the arrangement of the invention, selected weft threads for insertion are carried, one at a time, through the warp shed under respective different weft carrying forces suited for the weft threads. The different weft carrying forces may be produced by varying pressures at which air is ejected, intervals of time during which air is ejected under pressure, or the manner in which subnozzles are positioned along the warp shed. There is provided a control means for changing the air pressures and ejection time intervals in synchronism with operation of the air jet loom. | big_patent |
TECHNICAL FIELD
[0001] The present invention relates to a bast fibre yarn obtained through spinning bast fibres, and a process of making thereof, in particular, relates to a bast fibre yarn obtained through twice health-preserving bast fibres and blended spinning bast fibres and other fibres, together with a process of making thereof.
BACKGROUND OF THE INVENTION
[0002] Bast fabrics have gained more and more popularity with people, as they are low electrostatic and have the antibacterial speciality and great absorbency. However, bast fibre, especially jute fibres include great amount of lignin, is more rigid and brittle than cotton fibres. Generally, bast fibres need to be humidified for health preservating before spun by existing technology, wherein, health preservating refers to put bast fibres in a certain temperature and humidity environment for a certain period of time. Health preservating can improve the flexibility of bast fibres. However, because of the loss of water during processing, bast fibres will become dry and easily broken. For instance, in the art of blended spinning bast fibres and other fibres, when the yarn is 12 s in thinness, the end breakage rate may reach up to 300-400 times per hour for each machine averagely, which greatly raises the difficulty of bast fibres spinning, thereby reducing work efficiency and quality of products.
BRIEF DESCRIPTION OF INVENTION
[0003] One of the purposes of this invention is to provide a bast fibre yarn obtained through spinning bast fibres, and also provide step simple and efficient process of making thereof, which with low end breakage rate; additionally, another purposes of this invention is to provide a multi-fibre yarn obtained through blended spinning bast fibres and other fibres, and further provide an step simple and efficient process of making thereof, which may also with low end breakage rate.
[0004] In the present invention, a process for spinning bast fibres comprising the steps of:
[0005] a. Health preserving bast fibres;
[0006] b. Opening, cleaning, and carding the health preserved bast fibres, then, drawing the carded health preserved bast fibres into bast fibre strips;
[0007] c. Health preserving said bast fibre strips;
[0008] d. Spinning the health preserved bast fibre strips into bast fibre yarn.
[0009] The process for spinning bast fibres, wherein the step c is implemented under the circumstance where the temperature ranges from 30° C. to 80° C.
[0010] The process for spinning bast fibres, wherein said step c is implemented under the circumstance where the relative humidity ranges from 80% to 100%.
[0011] The process for spinning bast fibres, wherein said step c is implemented under the circumstance where the duration of health preserving said bast fibre strips ranges from 2 hours to 14 hours.
[0012] The process for spinning bast fibres, wherein said bast fibres are either jute fibres, kenaf fibres, or hemp fibres, or at least two of them.
[0013] The process for spinning bast fibres, wherein the weight percentage of jute fibres in bast fibres ranges from 20% to 100%.
[0014] A bast fibres yarn, wherein said bast fibre yarn is produced through the following steps:
a. Health preserving bast fibres; b. Opening, cleaning, and carding the health preserved bast fibres, then drawing the carded health preserved bast fibres into bast fibre strips; c. Health preserving said bast fibre strips; d. Spinning the health preserved bast fibre strips into bast fibre yarn.
[0019] The bast fibres yarn, wherein said bast fibres are either jute fibres, kenaf fibres, or hemp fibres, or at least two of them.
[0020] The bast fibres yarn, wherein the weight percentage of jute fibres in bast fibres ranges from 20%-100%.
[0021] A process for blended spinning bast fibres and other fibres comprises the steps of:
[0022] a. Health preserving bast fibres.
[0023] b. Blending the health preserved bast fibres with other fibres, then Opening, cleaning, and carding the blended fibres, after that drawing the carded blended fibres into multi-fibre strips.
[0024] c. Health preserving said multi-fibre strips;
[0025] d. Spinning the health preserved multi-fibre strips into multi-fibre yarn.
[0026] The process for blended spinning bast fibres and other fibres, wherein, the temperature for the step c ranges from 30° C. to 80° C.
[0027] The process for blended spinning bast fibres and other fibres, wherein the relative humidity for said step c is from 80% to 100%.
[0028] The process for blended spinning bast fibres and other fibres, wherein, the duration of step c ranges from 2 hours to 14 hours.
[0029] The process for blended spinning bast fibres and other fibres, wherein said bast fibres are either jute fibres, kenaf fibres, or hemp fibres, or at least two of them.
[0030] The process for blended spinning bast fibres and other fibres, wherein the weight percentage of jute fibres in bast fibres ranges 20% to 100%.
[0031] The process for blended spinning bast fibres and other fibres, wherein the weight percentage of bast fibres in the blended fibres ranges from 20% to 99%.
[0032] A multi-fibre yarn, wherein said multi-fibre yarn is produced through the following steps:
[0033] a. Health preserving bast fibres;
[0034] b. Blending the health preserved bast fibres with other fibres, then Opening cleaning and carding the, blended fibres, after that drawing the carded blended fibres into multi-fibre strips.
[0035] c. Health preserving said multi-fibre strips;
[0036] d. Spinning the health preserved multi-fibres strips into multi-fibre yarn.
[0037] The multi-fibre yarn, wherein, said bast fibres are either jute fibres, kenaf fibres, or hemp fibres, or at least two of them.
[0038] The multi-fibre yarn, wherein, the weight percentage of jute fibres in bast fibres ranges from 20%-100%.
[0039] Said technique of the present invention have the advantages to the existing technologies: In the present invention, the art of conducting twice health preservations is adopted for blended spinning bast fibres and blended spinning bast fibres and other fibres, which allows the products to have more flexibility, and also improve the spinnability of bast fibres, thereby improving work efficiency and quality of products For instance, according to the process introduced in the present invention, the end breakage rate of yarn will be averagely reduced to 150-200 times per hour for each machine when the yarn is 12 s in fineness.
DETAILED DESCRIPTION OF THE INVENTION
[0040] Preferred embodiments of the present invention have been chosen for purposes of description, wherein:
EXAMPLE 1
[0041] An experiment is conducted by, firstly, health preserving jute fibres by existing technologies; then Opening, cleaning, and carding the health preserved jute fibres; next, drawing the carded health preserved fibres into jute fibre strips; after that, health preserving the jute fibre strips for 2 hours under the circumstance where the temperature is 30° C., and the relative humidity is 85%; finally, spinning the health preserved jute fibre strips into jute fibre yarn. It is discovered after the experiment on 100 samplings that end breakage rate of jute fibre yarn has been averagely reduced to 200 times per hour for each machine when the jute fibre yarn is 12 s in fineness.
EXAMPLE 2
[0042] An experiment is conducted by, firstly, health preserving jute fibres by existing technologies; then Opening, cleaning, and carding the health preserved jute fibres; next, drawing the carded health preserved fibres into jute fibre strips; after that, health preserving the jute fibre strips for 14 hours under the circumstance where the temperature is 80° C., and the relative humidity is 90%; finally spinning the health preserved jute fibre strips into jute fibre yarn. It is discovered after the experiment on 100 samplings that end breakage rate of jute fibre yarn has been averagely reduced to 161 times per hour for each machine when the jute fibre yarn is 12 s in fineness.
EXAMPLE 3
[0043] An experiment is conducted by, firstly, health preserving jute fibres by existing technologies; then Opening, cleaning, and carding the health preserved jute fibres; next, drawing the carded health preserved jute fibres into jute fibre strips; after that, health preserving the jute fibre strips for 4 hours under the circumstance where the temperature is 50° C., and the relative humidity is 100%; finally spinning the health preserved jute fibre strips into jute fibre yarn. It is discovered after the experiment on 100 samplings that end breakage rate of jute fibre yarn has been averagely reduced to 176 times per hour for each machine when the jute fibre yarn is 12 s in fineness.
EXAMPLE 4
[0044] An experiment is conducted by, firstly, health preserving kenaf fibres by existing technology; then Opening, cleaning, and carding the health preserved kenaf fibres; next, drawing the carded health preserved kenaf fibres into kenaf fibre strips; after that, health preserving the kenaf fibre strips for 3 hours under the circumstance where the temperature is 40° C., and the relative humidity is 95%; finally, spinning the health preserved kenaf fibre strips into kenaf fibre yarn. It is discovered after the experiment on 100 samplings that end breakage rate of kenaf fibre yarn has been reduced to 182 times per hour for each machine averagely when the kenaf fibre yarn is 12 s in fineness.
EXAMPLE 5
[0045] An experiment is conducted by, firstly, health preserving linen fibres by existing technology; then Opening, cleaning, and carding the health preserved linen fibres; next, drawing the carded health preserved linen fibres into linen fibre strips; after that, health preserving the linen fibre strips for 6 hours under the circumstance where the temperature is 60° C., and the relative humidity is 85%; finally, spinning the health preserved linen fibre strips into linen fibre yarn. It is discovered after the experiment on 100 samplings that end breakage rate of linen fibre yarn has been reduced to 154 times per hour for each machine averagely when the linen fibre yarn is 12 s in fineness.
EXAMPLE 6
[0046] An experiment is conducted by, firstly, health preserving hemp fibres by existing technology; then Opening, cleaning, and carding the health preserved hemp fibres; next, drawing the carded health preserved hemp fibres into hemp fibre strips; after that, health preserving the hemp fibre strips for 10 hours under the circumstance where the temperature is 70° C., and the relative humidity is 80%; finally spinning the health preserved hemp fibre strips into hemp fibre yarn. It is discovered after the experiment on 100 samplings that end breakage rate of hemp fibre yarn has been reduced to 168 times per hour for each machine averagely when the hemp fibre yarn is 12 s in fineness.
EXAMPLE 7
[0047] An experiment is conducted by, firstly, health preserving bast fibres by existing technology, wherein said bast fibres comprise 90% jute fibres and 10% kenaf fibres in weight percentage; then Opening, cleaning, and carding the health preserved combination of jute fibres and kenaf fibres; next, drawing the carded bast fibre combination into bast fibre strips; after that, health preserving the bast fibre strips for 8 hours under the circumstance where the temperature is 60° C., and the relative humidity is 95%; finally, spinning the health preserved bast fibre strips into bast fibre yarn. It is discovered after the experiment on 100 samplings that end breakage rate of bast fibre yarn has been reduced to 151 times per hour for each machine averagely when the bast fibre yarn is 12 s in fineness.
EXAMPLE 8
[0048] An experiment is conducted by, firstly, health preserving bast fibres by existing technology, wherein said bast fibres comprise 20% jute fibres and 80% hemp fibres in weight percentage; then Opening, cleaning, and carding the health preserved bast fibres; next, drawing the carded health preserved bast fibre combination into bast fibre strips; after that, health preserving the bast fibre strips for 12 hours under the circumstance where the temperature is 70° C., and the humidity is 90%; finally, spinning the health preserved bast fibre strips into bast fibre yarn. It is discovered after the experiment on 100 samplings that end breakage rate of bast fibre yarn has been reduced to 150 times per hour for each machine averagely when the bast fibre yarn is 12 s in fineness.
EXAMPLE 9
[0049] An experiment is conducted by, firstly, health preserving jute fibres by existing technology and blending the health preserved jute fibres with cotton fibres into blended fibres, wherein the weight proportion of jute fibres and cotton fibres is 1:1; then Opening, cleaning, and carding the blended fibres; next, drawing the carded blended fibres into multi-fibre strips; after that, health preserving the multi-fibre strips for 8 hours under the circumstance where the temperature is 70° C., and the relative humidity is 100%; finally, spinning the health preserved multi-fibre strips into multi-fibre yarn. It is discovered after the experiment on 100 samplings that end breakage rate of multi-fibre yarn has been reduced to 150 times per hour for each machine averagely when the multi-fibre yarn is 12 s in fineness.
EXAMPLE 10
[0050] An experiment is conducted by, firstly, health preserving jute fibres by existing technology and blending the health preserved jute fibres with terylene fibres into blended fibres, wherein the weight proportion of jute fibres and terylene fibres is 99:1; then Opening, cleaning, and carding the blended fibres; next, drawing the carded blended fibres into multi-fibre strips; after that, health preserving the multi-fibre strips for 2 hours under the circumstance where the temperature is 80° C., and the humidity is 80%; finally, spinning the health preserved multi-fibre strips into multi-fibre yarn. It is discovered after the experiment on 100 samplings that end breakage rate of multi-fibre yarn has been reduced to 185 times per hour for each machine averagely when the multi-fibre yarn is 12 s in fineness.
EXAMPLE 11
[0051] An experiment is conducted by, firstly, health preserving jute fibres by existing technology and blending the health preserved jute fibres with polypropylene fibres into blended fibres, wherein the weight proportion of jute fibres and polypropylene fibres is 55:45; then Opening, cleaning, and carding the blended fibres; next, drawing carded blended fibres into multi-fibre strips; after that, health preserving the blended fibre strips for 14 hours under the circumstance where the temperature is 50° C., and the relative humidity is 90%; finally, spinning the health preserved multi-fibre strips into multi-fibre yarn. It is discovered after the experiment on 100 samplings that the end breakage rate of multi-fibre yarn has been reduced to 163 times per hour for each machine averagely when the multi-fibre yarn is 12 s in fineness.
EXAMPLE 12
[0052] An experiment is conducted by, firstly, health preserving kenaf fibres by existing technology and blending the health preserved kenaf fibres with cotton fibres into blended fibres, wherein, the weight proportion of kenaf fibres and cotton fibres is 7:3; then, Opening, cleaning, and carding the combination of jute and kenaf; after that, drawing the carded blended fibres into multi-fibre strips; after that, health preserving the blended fibre strips for 4 hours under the circumstance where the temperature is 60° C., and the relative humidity is 85%; finally, spinning the health preserved multi-fibre strips into multi-fibre yarn. It is discovered after the experiment on 100 samplings that end breakage rate of multi-fibre yarn has been reduced to 171 times per hour for each machine averagely when the multi-fibre yarn is 12 s in fineness.
EXAMPLE 13
[0053] An experiment is conducted by, firstly, health preserving ramee fibres by existing technology and blending the health preserved ramee fibres with cotton fibres into blended fibres, wherein, the weight proportion of ramee fibres and cotton fibres is 1:4; then, Opening, cleaning, and carding the blended fibres; next, drawing the carded blended fibres into multi-fibre strips; after that, health preserving the multi-fibre strips for 4 hours under the circumstance where the temperature is 40° C., and the relative humidity is 95%; finally, spinning the health preserved multi-fibre strips into multi-fibre yarn. It is discovered after the experiment on 100 samplings that end breakage rate of multi-fibre yarn has been reduced to 180 times per hour for each machine averagely when the multi-fibre yarn is 12 s in fineness.
EXAMPLE 14
[0054] An experiment is conducted by, firstly, health preserving hemp fibres by existing technology and blending the health preserved hemp fibres with cotton fibres into blended fibres, wherein, the weight proportion of hemp fibres and cotton fibres is 2:3; then, Opening, cleaning, and carding the blended fibres; next, drawing the carded blended fibres into multi-fibre strips; after that, health preserving said multi-fibre strips for 3 hours under the circumstance where the temperature is 30° C., and the relative humidity is 85%; finally, spinning the health preserved multi-fibre strips into multi-fibre yarn. It is discovered after the experiment on 100 samplings that end breakage rate has been reduced to averagely 180 times per hour for each machine averagely when the multi-fibre yarn is 12 s in fineness.
EXAMPLE 15
[0055] An experiment is conducted by, firstly, health preserving bast fibres by existing technology; wherein said bast fibres comprise 20% jute fibres and 80% kenaf fibres in weight percentage; then, blending the health preserved bast fibre combination with cotton fibres into blended fibres; wherein the weight proportion of the bast fibres and cotton fibres is 4:1; next, Opening, cleaning, and carding the blended fibres; after that, drawing the carded blended fibres into multi-fibre strips, and health preserving said multi-fibre strips for 12 hours under the circumstance where the temperature is 70° C., and the relative humidity is 95%; finally, spinning the health preserved multi-fibre strips into multi-fibre yarn. It is discovered after the experiment on 100 samplings that end breakage rate has been reduced to averagely 180 times per hour for each machine averagely when the multi-fibre yarn is 12 s in fineness.
EXAMPLE 16
[0056] An experiment is conducted by, firstly, health preserving bast fibres by existing technology; wherein said bast fibres comprise 90 % jute fibres and 10 % hemp fibres in weight percentage; then, blending the health preserved bast fibre combination with cotton fibres into blended fibres; wherein, the weight proportion of the bast fibre combination and cotton fibres is 3:1; next, Opening, cleaning, and carding the blended fibres; after that, drawing carded blended fibres into multi-fibre strips and health preserving said multi-fibre strips for 5 hours under the circumstance where the temperature is 50° C., and the relative humidity is 85%; finally, spinning the health preserved multi-fibre strips into multi-fibre yarn. It is discovered after the experiment on 100 samplings that end breakage rate has been reduced to 162 times per hour for each machine averagely when the multi-fibre yarn is 12 s in fineness.
[0057] While this invention has been described as having several preferred embodiments, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from this present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims. | The present invention introduces a process of spinning bast fibres through health preservating is as the following steps: Health preserving bast fibres; Opening and cleaning, carding the health preserved bast fibres and drawing the carded health preserved bast fibres into bast fibre strips; Health preserving said bast fibre strips; Spinning the health preserved fibre strips into yarn; the present invention also introduces a kind of yarn made by such process; The present invention further introduces a process of blended spinning bast fibre with other fibres through health preservating, and the yarn made by such process. The present invention realizes low end breakage rate, and high efficiency, so as to achieve high quality product. | big_patent |
BACKGROUND OF THE INVENTION
[0001] The present invention relates generally to nip presses used to exert pressing forces on moving webs for the formation of, for example, paper, textile material, plastic foil and other related materials. In particular, the present invention is directed to methods and apparatus for measuring and removing the effects of rotational variability from the nip pressure profile of nip presses which utilize imbedded sensors in covered rolls. While prior art presses which utilize rolls with imbedded sensors may be capable of detecting variations in pressure along the length of the roll, these same imbedded sensors may not be capable of measuring and compensating for rotational variability that can be generated by the high speed rotation of the covered roll. The present invention provides a method and apparatus for measuring and removing rotational variability from the nip pressure profile of the covered roll so as to obtain a more true profile of the nip pressure being developed in the nip region.
[0002] Nipped rolls are used in a vast number of continuous process industries including, for example, papermaking, steel making, plastics calendering and printing. The characteristics of nipped rolls are particularly important in papermaking. In the process of papermaking, many stages are required to transform headbox stock into paper. The initial stage is the deposition of the headbox stock, commonly referred to as “white water,” onto a paper machine forming fabric, commonly referred to as a “wire.” Upon deposition, the a portion of the white water flows through the interstices of the forming fabric wire leaving a mixture of liquid and fiber thereon. This mixture, referred to in the industry as a “web,” can be treated by equipment which further reduce the amount of moisture content of the finished product. The fabric wire continuously supports the fibrous web and advances it through the various dewatering equipment that effectively removes the desired amount of liquid from the web.
[0003] One of the stages of dewatering is effected by passing the web through a pair or more of rotating rolls which form a nip press or series thereof, during which liquid is expelled from the web via the pressure being applied by the rotating rolls. The rolls, in exerting force on the web and fabric wire, will cause some liquid to be pressed from the fibrous web. The web can then be advanced to other presses or dry equipment which further reduce the amount of moisture in the web. The “nip region” is the contact region between two adjacent rolls through which the paper web passes. One roll of the nip press is typically a hard steel roll while the other is constructed from a metallic shell covered by a polymeric cover. However, in some applications both roll may be covered. The amount of liquid to be pressed out of the web is dependent on the amount of pressure being placed on the web as it passes through the nip region. Later rolls in the process at the machine calender are used to control the caliper and other characteristics of the sheet. Covered rolls are at times used at the calender. The characteristics of the rolls are particularly important in papermaking as the amount of pressure applied to the web during the nip press stage can be critical in achieving uniform sheet characteristics.
[0004] One common problem associated with such rolls can be the lack of uniformity in the pressure being distributed along the working length of the roll. The pressure that is exerted by the rolls of the nip press is often referred to as the “nip pressure.” The amount of nip pressure applied to the web and the size of the nip can be important in achieving uniform sheet characteristics. Even nip pressure along the roll is important in papermaking and contributes to moisture content, caliper, sheet strength and surface appearance. For example, a lack of uniformity in the nip pressure can often result in paper of poor quality. Excessive nip pressure can cause crushing or displacement of fibers as well as holes in the resulting paper product. Improvements to nip loading can lead to higher productivity through higher machine speeds and lower breakdowns (unplanned downtime).
[0005] Conventional rolls for use in a press section may be formed of one or more layers of material. Roll deflection, commonly due to sag or nip loading, can be a source of uneven pressure and/or nip width distribution. Worn roll covers may also introduce pressure variations. Rolls have been developed which monitor and compensate for these deflections. These rolls generally have a floating shell which surrounds a stationary core. Underneath the floating shell are movable surfaces which can be actuated to compensate for uneven nip pressure distribution.
[0006] Previously known techniques for determining the presence of such discrepancies in the nip pressure required the operator to stop the roll and place a long piece of carbon paper or pressure sensitive film in the nip. This procedure is known as taking a “nip impression.” Later techniques for nip impressions involve using mylar with sensing elements to electronically record the pressures across the nip. These procedures, although useful, cannot be used while the nip press is in operation. Moreover, temperature, roll speed and other related changes which would affect the uniformity of nip pressure cannot be taken into account.
[0007] Accordingly, nip presses were developed over the years to permit the operator to measure the nip pressure while the rolls were being rotated. One such nip press is described in U.S. Pat. No. 4,509,237. This nip press utilizes a roll that has position sensors to determine an uneven disposition of the roll shell. The signals from the sensors activate support or pressure elements underneath the roll shell, to equalize any uneven positioning that may exist due to pressure variations. The pressure elements comprise conventional hydrostatic support bearings which are supplied by a pressurized oil infeed line. The roll described in U.S. Pat. No. 4,898,012 similarly attempts to address this problem by incorporating sensors on the roll to determine the nip pressure profile of a press nip. Yet another nip press is disclosed in U.S. Pat. No. 4,729,153. This controlled deflection roll further has sensors for regulating roll surface temperature in a narrow band across the roll face. Other controlled deflection rolls such as the one described in U.S. Pat. No. 4,233,011, rely on the thermal expansion properties of the roll material, to achieve proper roll flexure.
[0008] Further advancements in nip press technology included the development of wireless sensors which are imbedded in the sensing roll covers of nip presses as is disclosed in U.S. Pat. Nos. 7,225,688; 7,305,894; 7,392,715; 7,581,456 and 7,963,180 to Moore et al. These patents show the use of numerous sensors imbedded in the roll cover, commonly referred to as a “sensing roll,” which send wireless pressure signals to a remote signal receiver. U.S. Pat. No. 5,699,729 to Moschel discloses the use of a helical sensor for sensing pressure exhibited on a roll. Paper machine equipment manufacturers and suppliers such as Voith GmbH, Xerium Technologies, Inc. and its subsidiary Stowe have developed nip presses which utilize sensors imbedded within the sensing roll cover. These nip press generally utilize a plurality of sensors connected in a single spiral wound around the roll cover in a single revolution to form a helical pattern. An individual sensor is designed to extend into the nip region of the nip press as the sensing roll rotates. In this fashion, the helical pattern of sensors provides a different pressure signal along the cross-directional region of the nip press to provide the operator with valuable information regarding the pressure distribution across the nip region, and hence, the pressure that is being applied to the moving web as it passes through the nip region.
[0009] Control instrumentation associated with the nip press can provide a good representation of the cross-directional nip pressure (commonly referred to as the “nip pressure profile” or just “nip profile”) and will allow the operator to correct the nip pressure distribution should it arise. The control instruments usually provide a real time graphical display of the nip pressure profile on a computer screen or monitor. The nip profile is a compilation of pressure data that is being received from the sensors located on the sensing roll. It usually graphically shows the pressure signal in terms of the cross-directional position on the sensing roll. The y-axis usually designates pressure in pounds per linear inch while the x-axis designates the cross-directional position on the roll.
[0010] While a single line of sensors on the sensing roll may provide a fairly good representation of nip pressure cross-directional variability, these same sensors may not properly take into account the variability of pressure across the nip region caused by the high speed rotation of the sensing roll. The dynamics of a cylinder/roll rotating at a high angular speed (high RPMs) can cause slight changes to the pressure produced by the cylinder/roll that are not necessarily detectable when the cylinder/roll is at rest or rotating at a low speed. Such dynamic changes could be the result of centrifugal forces acting on the cylinder/roll, roll flexing, roll balance, eccentric shaft mounting or out-or round rolls and could possibly be influenced by environmental factors. The dynamic behavior of a typical high speed rotating cylinder/roll is often characterized by a development of an unbalance and bending stiffness variation. Such variations along the cylinder/roll are often referred to as rotational variability. Unbalance can be observed as a vibration component at certain rotating frequencies and also can cause unwanted bending of the flexible cylinder/roll as a function of the rotating speed. Since the lengths of the sensing rolls used in paper manufacturing can be quite long, unbalance in the rotating rolls can pose a serious problem to the paper manufacturer since a less than even nip pressure profile may be created and displayed by the control equipment. Any unwanted bending of the sensing roll can, of course, change the amount of pressure being exerted on the web as it travels through the nip roller. Again, since even nip pressure is highly desired during paper manufacturing, it would be highly beneficial to correctly display the nip pressure profile since any corrects to be made to the rotating roll based on an inaccurate nip pressure profile could certainly exacerbate the problem. A single sensor located at an individual cross-directional position on the sensing roll may not be able to compensate for the effect of rotational variability at that sensor's position and may provide less than accurate pressure readings. There are three primary measurements of variability. The true nip pressure profile has variability that can be term cross-directional variability as it is the variability of average pressure per cross-direction position across the nip. Each sensor in a single line of sensors may have some variability associated with it that may be calculated as the data is collected at high speed. This particular variability profile represents the variability of the high speed measurements at each position in the single line of sensors. This variability contains the variability of other equipment in the paper making process including the rotational variability of the roll nipped to the sensing roll. The third variability profile is the nip profile variability of multiple sensors at each cross-directional position of the roll. This variability represents the “rotational variability” of the sensing roll as it rotates through its plurality or sensing positions.
[0011] One of the problems of rotational variability is the creation of “high spots” and “low stops” at various locations along the sensing roll. A single sensor located at a cross-directional position where a high spot or low spot is found could provide the processing equipment with an inaccurate pressure reading being developed at that location. This is due to the fact that the overall pressure that is developed at the sensor's location as the roll fully rotates through a complete revolution will be lower that the measured “high spot” reading. Accordingly, a nip pressure profile which is based on the reading of a sensor located at a high or low spot will not be indicative of the average pressure being developed that that location. The processing equipment, in relying on this single, inaccurate reading, will calculate and display a nip pressure profile which is at least partially inaccurate. If a number of single sensors are located at numerous high or low spots, then the processing equipment will display a nip pressure profile which has numerous inaccuracies. The operator of the papermaking machinery may not even be aware that the processing system is displaying an inaccurate nip pressure profile. Further, attempts to correct the sensing roll based on an inaccurate nip pressure profile could lead to even greater inaccuracies.
[0012] Therefore, it would be beneficial if the manufacturer could detect and measure any rotational variability along the length of the covered roll of a nip press and compensate for it when a real time nip pressure profile is being calculated and displayed. The present invention provides a better measurement of the true nip pressure profile and is also capable of providing a previously unmeasured nip profile variability of the rotation (rotational variability). Furthermore, certain arrangements of sensing elements will provide information on the wear of the cover. Compensation for any rotational variability should produce a nip pressure profile which is a more accurate representation of the pressure being developed along the nip region of the press. The present inventions satisfy these and other needs.
SUMMARY OF THE INVENTION
[0013] The present invention provides apparatus and methods for accurately detecting, measuring and at least partially removing any effects of rotational variability from a covered roll (also referred to as a “sensing roll”) used in nip presses. The present invention compensates for this effect allowing a more accurate display of the nip pressure profile to be calculated and displayed. The present invention thus provides the machine operator with a more accurate representation of the actual pressure distribution across the nip press. The present invention could be used in collaboration with correcting instrumentation which can eliminate or compensate for pressure variability at locations across the sensing roll of the press. The data obtained from the arrangement of sensors along the sensing roll allows for the calculation and display of a rotational variability profile which can provide the operator with additional real time information concerning the dynamics of the pressure readings in order to obtain a more accurate nip pressure profile. The present invention can compensate for rotational variability in the sensing mechanism by calculating, for example, an average pressure value at each cross-directional (“CD”) position along the sensing roll. The present invention also could calculate and obtain a more accurate nip pressure profile utilizing other models, such as curve fitting.
[0014] The present invention uses multiple sensors circumferentially spaced at various cross-directional positions along the sensing roll in order to cancel the effects of rotational variability which may, or may not, be acting on the sensing roll. These strategically-placed sensors are designed to measure the pressure being placed against the web that is being advanced through the nip press. Previous work has demonstrated that roll rotational variability principally occurs at 1 times the rotational frequency of the roll and occasionally at 2 times the rotational frequency, primarily near the edges of the roll. Higher frequencies are rarely seen and then normally only at the extreme edges of the roll. In additional, cycles at each cross-directional position may be in phase where the highs and lows occur simultaneously across the entire roll width (known as “barring”) or the phasing of the highs and lows may vary across the roll as it rotates. Analysis of these variability patterns has demonstrated that the average of measurements of two sensors spaced 180° circumferential apart at a cross-directional position of a covered roll should provide a good measurement of the actual pressure being developed and would cancel, or at least partially cancel, any rotational variability of 1 times the rotational frequency that might develop at this position. Similarly the average of measurements of three sensors spaced 120° or four sensors spaced 90° circumferential apart at a cross-directional position of a covered roll should provide a good measurement of the actual pressure being developed and would cancel, or at least partially cancel, any rotational variability of 2 times the rotational frequency that might develop at this position. Alternate positioning of multiple sensors to remove the effect of rotation is possible. In this manner, a more true measurement of the pressure distribution across the nip region should be obtainable. Information on higher frequency barring which is indicative of cover wear and has been seen at calender stacks may be obtained by spacing the sensing elements at different rotational positions. The difference between individual sensing elements and the average of the group of sensing elements at the same cross-direction progression provides a measure of the roundness of the roll and shape of the cover. The progression of this difference as the cover ages is an indicator of cover wear.
[0015] The present invention provides advantages over sensing rolls and system which utilize a single sensor assigned to measure the pressure at a particular cross-directional position. Sensing rolls which just utilize a single sensor disposed at a cross-directional position on a roll lack the ability to take secondary measurements at the same cross-directional position for purposes of comparison to determine if there is any unbalance at that particular cross-directional position. As a result, such a sensing roll may provide inaccurate readings for calculating and displaying the nip profile. If the single sensor is placed at a position where there is a high or low spot, caused by rotational imbalance, then that sensor's pressure reading will not be quite accurate and its reading would lead to the calculation of an inaccurate nip pressure profile. Additionally, the use of single sensors at each CD position cannot generate the necessary data to allow for the calculation and display of a rotational variability profile which could provide the operator with additional real time information in order to obtain a more accurate nip pressure profile. The present invention allows for the calculation and display of such a rotational variability profile, along with the nip pressure profile.
[0016] In one aspect, the sensing roll for use in a nip press includes strategically-placed sensors including a first set of sensors disposed in a particular configuration along a roll cover that overlies a cylindrical member. Each sensor of this first set is located at a particular lateral position (cross-directional position) on the roll cover. The sensing roll further includes additional sets of sensors which are likewise disposed in a particular configuration on the roll cover, each sensor of the second set being likewise disposed at a particular cross-directional position. Each sensor of the first set of sensors has a corresponding sensor in the additional sets to define the CD group of sensors that are utilized to take the pressure readings at a particular cross-directional position. Again, each sensor at the cross-directional position is spaced circumferentially apart from the other. Multiple corresponding sensors can be strategically placed at different cross-directional positions along the length of the sensing roll, each pair of sensors designed to measure the pressure being developed at that cross-directional position. Each sensor will measure the pressure as it enters the nip region of the press. In theory, each corresponding sensors of a CD group should measure the same pressure at the particular cross-directional position if the sensing roll is truly balanced. If the pressure measurements for the two corresponding sensors are significantly different, then the measurements would indicate some variability that may be caused by the dynamics of the rotating sensing roll. The present invention allows the sensing roll to take multiple, not just one, pressure measurements at each cross-directional position during each 360° revolution of the sensing roll. These multiple measurements are utilized to obtain a more accurate nip pressure profile and a rotational variability profile. In one aspect of the invention, the readings at each sensor can be averaged to determine an average pressure measurement at that particular cross-directional position. This averaged measurement can then be used in computing and displaying the nip pressure profile. The same readings can be used to calculate and display the rotational variability profile of the operating nip press. The variability of the readings at each position will be monitored and displayed to determine if the roll rotational variability is stable or increasing. There are many possible measures of this variability including variance, standard deviation, 2 sigma, percent of process, co-variance, peak to peak. Increasing variability using any measure may be indicative of a potential failure in the bearings or roll cover or other roll problems.
[0017] In another aspect, multiple sets of sensors are disposed so as a particular pattern of lined-up sensors are created. For example, the pattern could be a continuous helical configuration which extends around the sensing roll in one revolution forming a helix around the sensing roll. The sensors of several sets can be aligned in a number of different patterns along the length of the sensing roll in order to develop a good representative nip pressure profile. In another aspect, the continuous line of sensors can extend only partially around the sensing roll, for example, in one half (½) revolution. A second set of sensors would also extend around the sensing roll in one half (½) revolution. In this manner, only a partial helix is formed around the sensing roll 10 . This arrangement of sensors still allows a pair of sensors to be assigned to a particular CD position. These sets of sensors would be spaced 180° circumferential apart from each other. In a similar manner three helixes may be wound 120° each, four 90° each or n helixes 360°/n each. The particular advantage of this arrangement of sensors is in sensing short wavelength bars that may be associated with cover wear as each sensing element is at a different rotational position.
[0018] In another aspect, a system for calculating and displaying a nip pressure profile and rotational variability profile for a nip press includes a sensing roll configured with a second roll in a nip arrangement, the sensing roll and the second roll adapted to rotatingly press matter therebetween in a nip region. The sensing roll has a plurality of cross-directional positions defined along its length. The sensing roll including a first set of pressure-measuring sensors and additional sets of pressure-measuring sensors, each sensor of the plural sets of sensors being disposed at a particular cross-directional position along the sensing roll. Each sensor is configured to sense and measure pressure when the sensor enters the nip region of the nip press. Again, each sensor of the first set has corresponding sensors in the additional sets which are located at the same cross-directional position but are spaced apart circumferentially on the sensing roll to provide multiple pressure readings at each cross-directional position. The plurality of readings can be used to calculate and formulate the nip pressure profile and rotational variability profile for the press. In one aspect, an average pressure reading at each location can be calculated to obtain a more accurate nip pressure profile.
[0019] A transceiver can be attached to the sensing roll and to each of the sensors of the multiple sets for transmitting data signals from the sensors to a receiver unit. A processing unit for calculating the nip pressure distribution based on the pressure measurements of each CD group of corresponding sensors of the first and additional sets of sensors can be coupled to the sensing roll. A display unit also could be coupled to the processing unit to provide a visual display of the nip pressure profile and the rotational variability profile.
[0020] A method for sensing and removing the effects of rotational variability from the nip pressure profile of a sensing roll of a nip press includes providing a sensing roll having a working length and a number of cross-directional positions disposed along the working length. Multiple pressure-measuring sensors are placed at each of the cross-directional positions, the sensors of each cross-directional position being spaced apart circumferentially from each other. The pressure being exerted on each sensor of each CD group as the sensor moves into the nip region of the nip press is then measured with the pressure measurements of each sensor at that cross-directional position being calculate to obtain an average pressure measurement at the respective cross-directional position. The obtained pressure measurements calculated at each cross-directional position can then be utilized to create a nip pressure profile for the nip press.
[0021] In yet another aspect, a method for measuring and removing the effects of rotational variability from the nip pressure profile of a sensing roll of a nip press includes measuring the pressure exerted on a first sensor disposed at a particular cross-directional position on the sensing roll of the nip press as the first sensor enters the nip region of the press. The pressure exerted on additional sensors is also measured as the second sensor enters the nip region of the press. The additional sensors are located at the same cross-directional position as the first sensor but spaced apart circumferentially from the first sensor. The pressure measurements of the multiple sensors are used to calculate and display the nip pressure profile and rotational variability profile. Multiple pluralities of sensors could be placed at various cross-directional positions along the sensing roll in order to measure pressures at multiple offset locations for each cross-directional position. The pressure measurements from the multiple sensors for each cross-directional position are averaged and used to calculate and display the nip pressure profile that is developed across the nip region. The method may include providing corrective procedures to the sensing roll in order to adjust for high or low pressure spots along the nip pressure profile.
[0022] These and other advantages of the present invention will become apparent from the following detailed description of preferred embodiments which, taken in conjunction with the drawings, illustrate by way of example the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1 is a perspective view showing a nip press which utilizes a particular embodiment of a sensing or covered roll made in accordance with the present invention.
[0024] FIG. 2 is an end, schematic view of the nip press of FIG. 1 showing the formation of a web nipped between the nip rolls, the nip width of the nip press being designated by the letters “NW.”
[0025] FIG. 3A is a side elevational view of a particular embodiment of a sensing roll made in accordance with the present invention which shows the placement of two sets of sensors along the length of the roll.
[0026] FIG. 3B is an end view of the sensing roll of FIG. 3A showing the placement of the first and second sets of sensors some 180° apart circumferentially on the sensing roll.
[0027] FIG. 4 is a side elevational view showing the placement of the two lines of sensors along the length of the sensing roll with sensors disposed within the nip region which is designated by a pair of dotted lines.
[0028] FIG. 5 is a side elevational view showing the placement of the two lines of sensors along the length of the sensing roll after the sensing roll has rotated 180° from its initial position shown in FIG. 4 .
[0029] FIG. 6A is a side view of a particular embodiment of a sensing roll made in accordance with the present invention which shows the placement of three sets of sensors along the length of the roll.
[0030] FIG. 6B is an end view of the sensing roll of FIG. 6A showing the placement of the first, second and third sets of sensors some 120° apart circumferentially on the sensing roll.
[0031] FIG. 7A is a side view of a particular embodiment of a sensing roll made in accordance with the present invention which shows the placement of four sets of sensors along the length of the roll.
[0032] FIG. 7B is an end view of the sensing roll of FIG. 7A showing the placement of the first, second, third and fourth sets of sensors some 90° apart circumferentially on the sensing roll.
[0033] FIG. 8A is a side view of a particular embodiment of a sensing roll made in accordance with the present invention which shows the placement of two sets of sensors wound 180° circumferentially along the length of the roll.
[0034] FIG. 8B is an end view of the sensing roll of FIG. 8A showing the placement of the first and second sets of sensors some 180° apart circumferentially on the sensing roll.
[0035] FIG. 9A is a side view of a particular embodiment of a sensing roll made in accordance with the present invention which shows the placement of three sets of sensors wound 120° circumferentially along the length of the roll.
[0036] FIG. 9B is an end view of the sensing roll of FIG. 9A showing the placement of the sets of sensors some 120° apart circumferentially on the sensing roll.
[0037] FIG. 10A is a side view of a particular embodiment of a sensing roll made in accordance with the present invention which shows the placement of four sets of sensors wound 90° circumferentially along the length of the roll.
[0038] FIG. 10B is an end view of the sensing roll of FIG. 10A showing the placement of the sets of sensors some 90° apart circumferentially on the sensing roll.
[0039] FIG. 11 is a schematic drawing showing the basic architecture of a particular monitoring system and paper processing line which could implement the sensing roll of the present invention.
[0040] FIG. 12 is a graphical display showing a plot of normalized error versus profile position for a single sensor array and two sensor array showing a helical pattern of in-phase variability over one cycle.
[0041] FIG. 13 is a graphical display showing a plot of normalized error versus profile position for a single sensor array and two sensor array (180°) showing a helical pattern of out of phase variability over one cycle.
[0042] FIG. 14 is a graphical display showing a plot of normalized error versus profile position for a single sensor array, a two sensor array (180°) and three sensor array (120°) showing a helical pattern of out of phase variability over one cycle/rotation center and 2 cycles/rotation edges.
[0043] FIG. 15 is a graphical display showing a comparison of nip pressure versus profile position for 3 sensor arrays for array 1 (0°), array 2 (90°) and array 3 (180°).
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0044] The present invention relates to rolls for use particularly in nipped roll presses, in which rolls exert pressing forces on webs for forming paper, textile material, plastic foil and other related materials. Although the present invention may be used in the above industries, the discussion to follow will focus on the function of rolls for use particularly in the manufacture of paper and particularly to a nip press for dewatering a fibrous web, comprising a sensing roll disposed so as to rotatingly cooperate with another roll in the nip press. FIGS. 1-5 depict the embodiment wherein two sensors are positioned 180° circumferentially across the width of the roll at each cross-directional location as this provides the simplest illustration. Additional embodiments with multiple sensors at each CD location can be extrapolated, as is shown in FIGS. 6-8B .
[0045] As shown in FIG. 1 , a schematic perspective view shows a sensing roll 10 made in accordance with the present invention as a portion of a nip press 12 which includes a second roll 14 that cooperates with the sensing roll 10 to produce pressure on a fibrous web 16 that is advanced between the two rolls 10 , 14 . The sensing roll 10 and second roll 14 rotate, as is indicated by arrows in FIG. 2 , and are spaced apart at a nip region 18 where the two rolls 10 , 14 somewhat meet in order to place pressure on the fibrous web 16 so as to remove some of the liquid suspended in the web 16 . The letters NW in FIG. 2 indicate the formed “nip width” of the nip region 18 . This nip region 18 extends along the entire cross-directional length of the sensing roll 10 and second roll 14 . The sensing roll 10 may include an inner base roll 20 and the outer roll cover 22 may comprise materials suitable for use in making a press roll. The inner base roll 20 may include one or more lower layers, with the outer roll cover 22 being the top layer. This composite sensing roll 10 with the roll cover 24 is commonly known as a “covered roll” in the industry. The second roll 14 may be an uncovered roll or also comprise of a number of layers of materials and a base roll as well. If multiple covered rolls are contained in the nip, each may have sensors and produce nip profiles and variability profiles. The nip profiles or the two covered rolls may be averaged together for greater accuracy in making nip profile adjustments. However, the variability profiles of each covered roll provide information about the condition of that specific roll. It should be appreciated that while the present embodiments focuses only in a single nip, it is possible to utilize single rolls involved in bi-nip, tri-nip or multi-nip interactions which are common in the paper industry. One two rolls 10 , 14 are depicted to more clearly describe the advantages associated with the present invention. However, multiple nip profiles can be generated with each independent sensing roll utilizes in the nip press.
[0046] Referring now to FIGS. 1 and 3 , a first set 24 of sensors 26 is associated with the sensing roll 10 along with a second set 28 of sensors 30 . Sensors 26 of the first set 24 are designated by a circle while sensors 30 of the second set 28 are designated by a square. Circles and squares have been used for ease in identify the sensors constituting the first set 24 of sensors from the second set 28 of sensors. However, in practice, these sensors 26 and 30 can be the exact same sensing device. Also, one or both of the rolls 10 , 14 may have sensors associated with the roll. For purposes of illustration, however, this discussion will focus on only one of the rolls having sensing and measuring capabilities.
[0047] These sensors 26 and 30 may be at least partially disposed within the roll cover 22 which forms the portion of the sensing roll 10 . Each of the sensors 26 and 30 are adapted to sense and measure a particular data parameter, such as, for example, the pressure that is being exerted on the sensor when it enters the nip region 18 . As can be best seen in FIG. 3A , the first set 24 of sensors 26 is shown disposed in a particular configuration along the sensing roll 10 , each sensor 26 being located at a particular lateral position (referred to as the “cross-directional position” or “CD position”) on the sensing roll 10 . Each cross-directional position is a particular distance from the first end 32 of the sensing roll 10 . As can be seen in the particular embodiment of FIG. 3A , the first set 24 of sensors 26 are disposed along a line that spirals around the entire length of the sensing roll in a single revolution forming a helix or helical pattern. The second set 28 of sensors 30 is likewise disposed along a line that spirals around the entire length of the sensing roll in a single revolution creating the same helix or helical pattern except that this second set 28 of sensors 30 is separated apart from the first set 24 some 180° circumferentially around the sensing roll 10 . FIG. 3B shows an end view of the first set 24 spaced approximately 180° apart from the second set 28 . The use of these two lines of sensors 26 , 30 allows a large amount of the outer surface of the sensing roll 10 to be measured while the roll 10 is rotating. While the particular pattern of the first set 24 and second set 28 is shown herein in a helical pattern around the roll 10 , it should be appreciated that these sets 24 , 28 of sensors can be disposed in other particular configurations to provide pressure measurements all along the sensing roll 10 .
[0048] Each sensor 30 of this second set 28 is disposed at a particular cross-directional position on the sensing roll 10 . Each sensor 26 of the first set 24 has a corresponding sensor in the second set 28 with each corresponding sensor of the first and second set being located at the same cross-directional position along the sensing roll. In this manner, each cross-directional position of the sensing roll has a pair of sensors which measure the pressure at two different circumferential positions. Each pair of corresponding sensors are located along the sensing roll 10 at a cross-directional position to provide two sensor readings when the sensing roll completes a full 360° rotation. The average of these two readings can then be utilized to calculate and display the nip pressure profile that is being developed on the rotating nip press 12 .
[0049] The manner in which the pressure measurements can be made is best explained by referring to FIGS. 4 and 5 . FIGS. 4 and 5 show side elevational views of the sensing roll 10 as it would be viewed looking directly into the nip region 18 which is depicted by a pair of dotted lines. FIG. 4 shows a typical view in which the sensing roll 10 has a pair of sensors 26 , 30 directly in the nip region ready to take a pressure measurement. A grid located at the bottom of the sensing roll 10 for illustrative purposes shows fourteen (14) individual cross-directional positions along the working length L of the sensing roll 10 . In FIG. 4 , the first set 24 of sensors 26 can be seen depicted positioned at cross-directional positions numbered 1 - 7 . Likewise, the second set 28 of sensors 30 are shown in cross-directional positions numbered 8 - 14 in FIG. 4 . The other sensor 26 of the first set 24 are disposed in cross-directional positions 8 - 14 but cannot be seen in FIG. 4 . Likewise, the remaining sensors 30 of the second set 28 are in positions 1 - 7 but cannot be seen in FIG. 4 since they are at the reverse side of the sensing roll. It should be appreciated that only fourteen cross-directional positions are shown in these drawings to provide a simple explanation of the manner in which the present invention operates. In actual operation, there can be many more cross-directional positional positions associated with a sensing roll given the long lengths and widths that are associated with these rolls.
[0050] Only the sensor 26 located in the 4 th cross-directional position and the sensor 30 located in the 11th cross-directional position are in proper position for taking the pressure measurement as they are located in the nip region NR. Once these two sensors 26 , 30 enter the nip region NR, the pressure being exerted on the sensor is measured. As the sensing roll 10 continues to rotate, the other sensors in the 5 th and 12 th cross-directional positions will then be located in the nip region NR and will be able to measure the pressure at these particular positions. Further rotation of the sensing roll 10 places the sensors in the 6 th and 13 th cross-directional positions into the nip region NR for pressure measurements. Eventually, the sensing roll 10 rotates 180° from its initial position shown in FIG. 4 and will again have sensors in the 4 th and 11 th cross-directional positions. This arrangement of sensors 26 , 30 is shown in FIG. 5 . The only difference is that a sensor 30 of the second set 28 is now in the 4 th cross-directional position and a sensor 26 of the first set 24 is in the 11 th cross-directional position. These sensors 26 and 30 shown in FIGS. 4 and 5 are corresponding sensors which read the pressure at the 4 th cross-directional position. Likewise, sensor 26 of the first set 24 in FIG. 5 is now in the 11 th cross-directional position ready to measure the pressure at that location. The sensor 30 in the 11 th cross-directional position shown in FIG. 4 and the sensor 26 in the 11 th cross-directional position of FIG. 5 constitute corresponding sensors which provide pressure readings at that particular location on the sensing roll. The system which processes the pressure measurements can take the average of the readings of each pair of corresponding sensors at a particular cross-directional position and calculate the nip profile at that position based on an average reading. For example, if the sensors 26 , 30 in the 4 th cross-directional position both read 200 lbs per linear inch (PLI) then their average would be 200 PLI. This would indicate that there is little, or no, pressure variation caused by the rotation of the sensing roll 10 . The average 200 PLI reading would then be used to calculate and display the nip pressure profile at that particular cross-directional position. For example, if the sensor 30 in the 11 th cross-directional position, as shown in FIG. 4 , reads 240 PLI and the sensor 26 in the 11 th position shown in FIG. 5 reads 160 PLI, then the average pressure would be 200 PLI. These two different readings at the 11 th cross-directional position would indicate a pressure variation that most likely would be attributed to the high speed rotation of the sensing roll 10 . However, in processing the nip pressure profile for the 11 th cross-directional position, the average pressure measurement of 200 PLI would be utilized since this average will cancel, or nearly cancel, the effect of rotational variability that is occurring along the sensing roll 10 . The average of the two measurements will result in a more accurate representation of the pressure being developed at that particular cross-directional position.
[0051] In prior art sensing rolls which utilize a single sensor at each cross-directional position, the processing unit would have single sensors at each cross-directional positions. A prior art sensing roll which has a single sensor at the 11 th cross-directional position in the illustrated example above could only rely on a single reading at that position in order to calculate and display the nip pressure profile. A prior art roll would then use either the 240 PLI or 160 PLI reading for determining and displaying the nip pressure profile at this location. Such a reading would be less than accurate as the sensing roll full rotates in a 360° revolution. Accordingly, the calculated nip pressure at this position will be less than accurate. However, the processing unit would display a nip pressure profile would appear to be accurate but in reality would be less than accurate. If adjustments are made to the sensing roll by the machine operator or through automatic adjustment equipment to compensate for high or low pressure readings, then the sensing roll could be adjusted to develop even more incorrect pressures at various locations in the nip region.
[0052] As the roll 10 rotates placing different sensors into the nip region, the respective sensors measure the pressure which is then transmitted to the processing unit. The processing unit associated with each sensing roll 10 can then calculate the average pressure of each pair of corresponding sensors at the various cross-directional positions and produce a nip pressure profile which can be visualized on a monitor or other visual screen. Computer equipment well known in the art could be utilized to process the pressure readings that are being made in milliseconds.
[0053] One method of the present invention for sensing and removing the effects of rotational variability from the nip pressure profile of a sensing roll of a nip press thus includes providing a sensing roll having a working length and a plurality of cross-directional positions disposed along the working length and the placement of pairs of pressure-measuring sensors at each cross-directional positions. In the particular embodiment shown in FIGS. 3A-5 , the method utilizes sensors being spaced apart 180° circumferentially from each other. This allows for two different pressure measurements to be made at each cross-directional position. The pressure exerted on each sensor of each pair as the sensor moves into the nip region of the nip press can then be measured and the average of each of the two sensors at each cross-directional position can be calculated to determine an average pressure measurement. The average pressure measurements at each cross-directional position can then be used to provide a nip pressure profile for the nip press.
[0054] It should be appreciated that while the present invention discloses mathematical modeling that utilizes the direct averaging of the measurements taken by each corresponding sensor, it could be possible to obtain a composite average measurement utilizing other types of models which can obtain and calculate an averaged measurement at each cross-directional position. For example, the operating equipment (data processors) could utilize another model such as “curve fitting” which also can provide the more accurate nip pressure profile. Still other models known in the art could be utilized with the multiple pressure readings from the various sensors to obtain the more accurate nip pressure profile.
[0055] Variations of the sensing roll are disclosed in FIGS. 6-8 . Referring initially to FIGS. 6A and 6B , three different sets of sensors are utilized and extend around the sensing roll 10 . As can be seen in the disclosed embodiment of the sensing roll 10 , a first set 24 of sensors 26 , a second set 28 of sensors 30 and a third set 32 of sensors 34 are shown as continuous lines of sensors which extend around the sensing roll in one full revolution, each set 24 , 28 , 32 forming a helix around the sensing roll 10 . Sensors 34 are shown as a triangle to distinguish that particular sensor from the sensors 26 , 30 of the other two sets 24 , 28 . Adjacent sets 24 , 28 and 30 of sensors are spaced 120° circumferential apart from each other (see FIG. 6B ) at a cross-directional position of the sensing roll 10 to provide a good measurement of the actual pressure being developed and would cancel, or at least partially cancel, any rotational variability of 2 times the rotational frequency that might develop at this CD position. Again, the measurements from each of the corresponding sensors at each CD position can be averaged to provide an averaged measurement which provides a more accurate representation of the nip pressure being developed at that CD position.
[0056] It should be appreciated that the working length of the sensing roll can be quite long and may require each set of sensors to be wound more than one times around the roll. Again, such a pattern is satisfactory as long as the pattern allows for three sensors to be use at each cross-directional position (spaced 120° apart) in order to produce three separate pressure readings which are then processed to produce a base reading.
[0057] Referring now to FIGS. 7A and 7B , a fourth set 36 of sensors 38 has been added to the sensing roll 10 to provide yet another sensor at each CD position. Adjacent sets 24 , 28 , 30 , 36 are spaced 90° circumferential apart from each other (see FIG. 7B ) at a cross-directional position of the sensing roll 10 to provide a good measurement of the actual pressure being developed and would cancel, or at least partially cancel, any rotational variability of 2 times the rotational frequency that might develop at this CD position. Again, It should be appreciated that the working length of the sensing roll can be quite long and may require each set of sensors to be wound more than one times around the roll. Such a pattern is satisfactory as long as the pattern allows for four sensors to be use at each cross-directional position (spaced 90° apart) in order to produce four separate pressure readings which are then processed to produce a base reading.
[0058] Referring now to FIGS. 8A and 8B , a first set 24 of sensors 26 is shown as a continuous line of sensors which extend around the sensing roll in one half (½) revolution. Likewise, a second set 28 of sensors 30 extend around the sensing roll in one half (½) revolution. In this manner, only a partial helix is formed around the sensing roll 10 . This arrangement of sensors 26 , 30 still allows a pair of sensors to be assigned to a particular CD position. Like the sensing roll 10 shown in FIGS. 3A-5 , adjacent sets 24 , 28 are spaced 180° circumferential apart from each other (see FIG. 8B ). The resulting structure creates a sensing roll that has only one sensor entering the nip region at any given time. This particular embodiment of the sensing roll 10 should provide a good measurement of the actual pressure being developed and would cancel, or at least partially cancel, any rotational variability of 2 times the rotational frequency that might develop at this CD position.
[0059] In a similar manner three helixes may be wound 120° each, four 90° each or n helixes 360°/n each. The particular advantage of this arrangement of sensors is in sensing short wavelength bars that may be associated with cover wear as each sensing element is at a different rotational position. FIGS. 9A and 9B show three continuous lines 24 , 28 and 32 of sensors 26 , 30 and 34 which extend around the sensing roll in a partial revolution (a 120° revolution). In this manner, only a partial helix is formed around the sensing roll 10 by each set 24 , 28 and 32 . This arrangement of sensors 26 , 30 and 34 allows group of sensors to be assigned to a particular CD position. Like the sensing roll 10 shown in FIGS. 6A and 6B , adjacent sets 24 , 28 and 32 are spaced 120° circumferential apart from each other along the roll (see FIG. 9B ). FIGS. 10A and 10B show four continuous lines 24 , 28 , 32 and 36 of sensors 26 , 30 , 34 and 38 which extend around the sensing roll in a partial revolution (a 90° revolution). Again, only a partial helix is formed around the sensing roll 10 by each set 24 , 28 , 32 and 36 . This arrangement of sensors 26 , 30 , 34 and 38 allows group of sensors to be assigned to a particular CD position. Like the sensing roll 10 shown in FIGS. 7A and 7B , adjacent sets 24 , 28 , 32 and 36 are spaced 90° circumferential apart from each other (see FIG. 10B ). The resulting structure creates a sensing roll that has only one sensor entering the nip region at any given time. This particular embodiment of the sensing roll 10 should provide a good measurement of the actual pressure being developed and would cancel, or at least partially cancel, any rotational variability of 2 times the rotational frequency that might develop at this CD position. Similar lines of sensors could be disposed along the length of the sensing roll 10 such that n lines of sensors forming partial helixes are formed and placed 360°/n along the length of the roll 10 . Adjacent lines of sensors would be spaced 360°/n circumferentially apart from each other along the roll.
[0060] The methods for sensing and removing the effects of rotational variability from the nip pressure profile of a sensing roll of a nip press utilizing the embodiments of FIGS. 6A-10B includes providing a sensing roll having a working length and a plurality of cross-directional positions disposed along the working length and the placement of pairs of pressure-measuring sensors at each cross-directional positions. The method will calculate an average pressure measurement utilizing the number of sensors placed at each CD position. In the embodiments of FIGS. 6A and 6B and FIGS. 9A and 9B , three sensors located a CD position are averaged. Likewise, the readings from the four sensors of the embodiments of FIGS. 7A and 7B and FIGS. 10A and 10B are utilized to produce an average pressure measurement. The embodiment of FIGS. 8A and 8B , like the embodiment of FIGS. 3A-5 , utilize a pair of sensor measurements at each CD position. The average pressure measurements at each cross-directional position can then be used to provide a nip pressure profile for the nip press.
[0061] The sensors used in the various sets can be electrically connected to a transmitter unit 40 which also can be attached to the sensing unit 10 . The transmitter unit 40 can transmit wireless signals which can be received by a wireless receiver located at a remote location. The wireless receiver can be a part of a system which processes the signals, creates the nip profile and sends corrective signals back to the sensing roll 10 . Sensors may be collected in the same collection period and average together for immediate use. However, the additional wireless transmission may reduce the battery life of the wireless unit. As the rotational variability changes slowly, alternating the collection between the sensors and averaging together the collections in the alternate collection periods will provide comparable information and may save battery life.
[0062] One particular system for processing the signals is shown in FIG. 11 and will be discussed in greater detail below. Wireless transmission can be carried out via radio waves, optical waves, or other known remote transmission methods. If a direct wired transmission is desired, slip ring assemblies and other well-known electrical coupling devices (not shown) could be utilized.
[0063] FIG. 11 illustrates the overall architecture of one particular system for monitoring of a product quality variable as applied to paper production. The system shown in FIG. 11 includes processing equipment which calculates and displays the nip pressure profile. For example, the pressure measurements can be sent to the wireless received from the transmitter(s) located on the sensing roll. The signals are then sent to the high resolution signal processor to allow the average pressure measurements to be calculated and utilized to create and display the nip pressure profile. Data can be transferred to the process control which can, for example, send signals back to the sensing roll to correct pressure distribution across the nip region. One such nip press which is capable of real time correction is described in U.S. Pat. No. 4,509,237, incorporated herein by reference in its entirety. This nip press utilizes a roll that has position sensors to determine an uneven disposition of the roll shell. The signals from the sensors activate support or pressure elements underneath the roll shell, to equalize any uneven positioning that may exist due to pressure variations. Other known equipment which can correct the roll cover could also be used.
[0064] The sensors can take any form recognized by those skilled in the art as being suitable for detecting and measuring pressure. Pressure sensors may include piezoelectric sensors, piezoresistive sensors, force sensitive resistors (FSRs), fiber optic sensors, strain gage based load cells, and capacitive sensors. The invention is not to be limited to the above-named sensors and may include other pressure sensors known to those of ordinary skill in the art. It should be appreciated that data relating to the operational parameter of interest, other than pressure, could be utilized with the present invention. In this case, the sensors could be used to measure temperature, strain, moisture, nip width, etc. The sensors would be strategically located along the sensing roll as described above. Depending on the type of sensor, additional electronics may be required at each sensor location. The design and operation of the above sensors are well known in the art and need not be discussed further herein.
[0065] The processor unit is typically a personal computer or similar data exchange device, such as the distributive control system of a paper mill that can process signals from the sensors into useful, easily understood information from a remote location. Suitable exemplary processing units are discussed in U.S. Pat. Nos. 5,562,027 and 6,568,285 to Moore, the disclosures of which are hereby incorporated herein in their entireties.
[0066] Referring now to FIGS. 12-15 , graphical displays are provided which further explains and presents typical mapping of roll variability which can develop during operation. Roll surfaces were mapped pursuant to the methods and apparatus described in U.S. Pat. No. 5,960,374 using paper properties sensors that were related to nip pressure. The mappings used an array of 5,000 elements broken into 100 CD positions and 50 rotational positions. The mappings confirmed that most roll variability occurs in 1 cycle per revolution in-phase across the roll or out-of-phase (the phase shifts with profile position). A 2 cycle per revolution pattern is sometime noted at the edges of the roll. Higher frequencies (such as 3 cycles per revolution) are rarely seen and then only at the extreme edges and have little impact. Three roll surface maps were normalized (scaled on 0-100%) and helical scan paths were superimposed over the surface maps. The true nip pressure profile was determined by averaging the 50 rotational positions at each of the 100 CD positions. The helical scan paths and the averages of two or more of these paths at various separation angles were used to develop estimates of the nip pressure profile. These estimates were then subtracted from the true nip profile to obtain the error in each estimate. FIGS. 12 and 13 demonstrate that two sensor arrays across the width of the roll and separated by 180° circumferentially are sufficient to remove most of the rotational variability when the variability is 1 cycle per revolution. FIG. 14 demonstrates that 2 arrays are not sufficient to handle the 2 cycle per revolution variability at the edges as the estimate difference from the true nip profile is an large at the edges as the single helical scan. For this case a minimum of 3 arrays separated by 120° would be needed. A larger number of arrays per revolution may further reduce the measurement error, but at a higher cost. Therefore, the embodiment of three (3) arrays (lines) of sensors separated by 120° circumferentially insures that all 1 cycle/revolution and 2 cycle/revolution variability is reduced. However, 2 arrays may be sufficient for many rolls without 2 cycle/revolution variability and more than 3 arrays may give superior variability measurement and reduction but at a higher cost.
[0067] FIG. 15 shows nip pressure profiles collected on a roll using the various embedded sensors. The data show clear differences in the profile between the 3 arrays. Most notably, arrays 1 & 3 (separated by 180°) show a significant difference in shape, especially in profile position 14 - 20 .
[0068] While there have been described herein what are considered to be preferred and exemplary embodiments of the present invention, other modifications of the invention shall be apparent to those skilled in the art from the teachings herein and, it is therefore, desired to be secured in the appended claims all such modifications as fall within the true spirit and scope of the invention. Thus, any modification of the shape, configuration and composition of the elements comprising the invention is within the scope of the present invention. Accordingly, what is desired to be secured by Letters Patent of the United States is the invention as defined and differentiated in the following claims. | Multiple groups of sensors are circumferentially spaced apart at each cross-directional position along a sensing roll of a nip press to measure and cancel or nearly cancel the effects of rotational variability which may be acting on the sensing roll. The strategically-placed sensors are designed to measure the pressure being placed against the web that is being advanced through the nip press. The average of the measurements of multiple sensors spaced circumferential apart provides a good cancellation of any rotational variability that might be found at a cross-directional position on the sensing roll. In this manner, a more true measurement of the nip pressure profile can be obtained and better adjustments made to reduce nip pressure profile variability. In addition, the nip variability profile may be used as a predictor of cover or bearing failures, resonant frequencies and other roll anomalies. | big_patent |
FIELD OF THE INVENTION
This invention relates to a combination electrical cord support for supporting an electrical cord of an electrical appliance and a holder for holding an article. The invention is particularly useful, but not limited, to an attachment for an ironing board for supporting the electrical cord of an electric iron above an ironing surface and for holding an article, such as a spray starch can or a beverage container.
BACKGROUND OF THE INVENTION
It is known to have cord support devices for supporting the electrical cord of an electric iron so that the cord will not interfere with the clothes being ironed. It is further known to incorporate on cord support devices an outlet for receiving the plug at the end of the electrical cord which is supported by the cord support device. U.S. Pat. Nos. 2,478,498 and 2,715,002 disclose such apparatus.
Frequently, an ironer wishes to have things like spray starch or other clothing treatments at hand while ironing. This means that it is frequently necessary to place such articles on the ironing board, which interferes with ironing, or to place them on a nearby surface, which is not convenient. In the case of a beverage container or other open container, the container could tip or fall spilling the contents on the ironing board or floor.
It is desired to have an apparatus for supporting the electrical cord and also for storing an article, such as spray starch can or beverage container.
It is further desired that a portion of the apparatus, such as an article holder, be removable from the ironing board when not in use in order to facilitate storage.
SUMMARY OF THE INVENTION
This invention relates to an apparatus mounted on an ironing board for guiding a cord of an iron and providing a holder for an article. The article has a clamp section for releasably securing the apparatus to the ironing board. A flexible cord support is pivotably attached to the clamp for supporting the electrical cord of the electrical appliance above the ironing board. An article holder is mounted to the clamp for holding an article. An electrical receptacle is carried by the clamp for receiving a plug of the electrical cord of the iron.
In a preferred embodiment, the clamp is "C" shaped and has a pair of leg portions extending from an end portion. One leg portion is adapted for engaging the ironing surface of the ironing board. The other leg portion is located below the underside of the ironing surface, an adjusting screw is threadedly journaled in a threaded bolt in the other leg portion. A movable jaw at an end of the adjusting screw located between the leg portions engages the underside of the ironing board for securing the apparatus to the ironing board. The flexible cord support has a first rod, a second rod and a resilient spring section. The first rod has a cord receiving end for receiving the cord. The resilient spring section is secured to a lower end of the first rod. The second rod has an upper end for detachably receiving the resilient spring section. A lower end of the second rod has a foot pivotably received by an opening defined by a brace and the upper leg portion of the clamp for permitting movement of the cord support between a raised position and a retracted position. A locking tab on the foot of the rod is releasably retained by a detent on the brace. The locking tab is engaged with and disengaged from the detent by sliding the foot relative to the brace. Engaging the locking tab with the detent retains the cord support in the raised position. The article holder has a pair of tangs detachably received by openings in a mounting brace mounted to the clamp.
Further objects, features and advantages of the present invention will become more apparent to those skilled in the art as the nature of the invention is better understood from the accompanying drawings and detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
For the purpose of illustrating the invention, there is shown in the drawings a form which is presently preferred; it being understood, however, that this invention is not limited to the precise arrangements and instrumentalities shown.
FIG. 1 is a perspective view of the invention, with the cord support in an installed raised position, and with the ironing board shown in phantom.
FIG. 2 is an enlarged view of the invention partially disassembled for storage, with the lower portion of the cord support shown in its retracted position in phantom.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings, wherein like numerals indicate like elements, there is illustrated an apparatus in accordance with the present invention. The apparatus 10 comprises a releasable clamp 12 for releasably securing the apparatus to a work surface, a flexible cord support 44 and a detachable article holder 66 which can be selectably attached to and detached from the apparatus.
In a preferred embodiment, the releasable clamp is a "C" shaped clamp 12 having an end portion 14 from which extend an upper leg portion 16 and lower leg portion 18. It is recognized that the releasable clamp means could also be a squeeze or friction clamp or other securing device. The end portion 14 and upper leg portion 16 and lower leg portion 18 of the clamp 12 define a bight or opening between them. The clamp 12 receives an ironing board 22, shown in phantom, in the bight between the leg portions 16 and 18. The upper leg portion 16 engages an ironing surface 23 of the ironing board 22. The lower leg portion 18 has a threaded hole, not shown, which receives an adjustment screw such as a threaded eye bolt 26. The eye bolt 26 has an eye portion 28 at one end to facilitate the rotation of bolt 26 by the thumb and fingers. A movable clamp jaw in the form of a plastic cap 30 is located on the other end of the threaded bolt 26 between leg portions 16 and 18 and has a flat surface 32 for engaging tile underside of the ironing board 22. The apparatus 10 is thus clamped to the ironing board 22 by sandwiching the ironing board between the upper leg portion 16 and the plastic cap 30.
The clamp 12 includes a retainer for retaining the flexible cord support 44 on clamp 12. The support may be integral with the clamp 12 or may comprise a separate brace 34 mounted to the upper leg portion 16 of the clamp 12, as shown. The brace 34 has a "U" shaped bend 36 and is secured to the upper leg portion 16 of the clamp 12, such as by rivets on either side of the "U" shaped bend 36. The upper leg portion 16 and the "U" shaped bend 36 of the brace 34 define an opening 38 which receives the cord support 44. The brace 34 has a detent such as a "L" shaped tab 40 projecting upward from the upper leg 16.
The cord support 44 is in the form of a flexible mast and has a foot portion 60 at one end, a cord receiving portion 52 at the other end to receive the electrical cord, and a flexible portion 50 for at least a part of its length between the ends. In a preferred embodiment, the cord support 44 has a first rod 46, a second rod 48, and a coiled spring resilient section 50 joining the first and second rods 46 and 48. The first, and upper, rod 46 has at an upper end a helical bent portion 52. The helical bent portion 52 is formed to provide spaces in the helical bent portion 52 allow the electrical cord from the iron, not shown, to be placed in the spaces so that the cord is supported above the ironing surface 23 of the ironing board 22. The lower end of the first rod 46 is attached to the coiled spring resilient section 50. The second, and lower, rod 48 of the cord support 44 has an upper end 58 which detachably receives the coiled spring resilient section 50, as best seen in FIG. 2. The second rod 48 also has a "L" shaped bend defining the foot 60 at the lower end. The foot 60 is pivotably and slideably received by the opening 38 defined by the "U" shaped bend 36 of the brace 34. At the end of the foot 60, extending at an angle of approximately 90° from the foot 60, is a tab 62. The tab 62 is retained by the "L" shaped tab 40 of the brace 34, which acts as a detent, to hold the cord support 44 in a raised position, as shown in FIG. 1.
In a preferred embodiment, the detachable article holder 66 has a lower circular hoop 68 and a pair of support bars 70. The support bars 70 are secured to the lower circular hoop 68 and form chords of the circle defined by hoop 68, thereby defining a base for retaining an article such as a can of starch, a spray bottle, a beverage container, or a remote control. The article holder 66 also has an upper hoop 72. The upper hoop 72 has a circular portion for approximately 345° and each end of the circular portion of the upper hoop 72 has a tang 74 depending downward therefrom. The article holder 66 has four vertical supports 76 extending between the lower hoop 68 and upper hoop 72 for spacing the hoops 68 and 72 and defining the article holder 66. The vertical supports 76 can be located inside or outside the hoops 68 and 72, and cooperate with upper hoop 72 to provide lateral support for an article. The article holder 66 has a vertical support bar 84 extending between the tangs 74 of the upper hoop 72. A single tang could be integral with one of the vertical supports instead of the tangs integral with the upper hoop 72. The detachable article holder 66 could also be made of other materials such as molded plastic.
The clamp 12 has a second support for detachably mounting the article holder 66. In a preferred embodiment, the clamp 12 has a second brace 78. The second brace 78 has a pair of "U" shaped bends 80. The second brace 78 is spot welded to the base 14 of the clamp 12 such that the "U" shaped bends 80 each define an opening 82, as best seen in FIG. 2, for detachably receiving the tangs 74 of the upper hoop 72.
The apparatus 10 has an extension portion, such as an "L" shaped bracket 88, for mounting an female electrical outlet 96. The "L" shaped bracket 88 has a first leg 90 and a second leg 92. The first leg 90 is welded to the lower leg portion 18 of the clamp 12. The second leg 92 depends downward in the plane with the end portion 14 of the clamp 12. The second leg 92 has a threaded hole, not shown, which receives a screw 94. The apparatus 10 has an female electrical outlet 96 with an electrical cord 98 extending to a plug (not shown). The female electrical outlet 96 is secured to the second leg 92 by the screw 94 and can receive the plug from the iron. The electrical outlet 96 is shown below the article holder 66 in the Figures so that article placed in the article holder 66 will not interfere with the outlet 96. However, the outlet 96 could be place in other locations such to the side of the article holder 66, using the extension portion or directly to the underside of the lower leg 18 of the clamp 12.
Referring to FIG. 2, the apparatus 10 is shown removed from the ironing board 22. The coiled spring resilient section 50, which is attached to the first drive 46 of the cord support 44, is removed from the upper end 58 of the second rod 48. The second rod 48 is shown in phantom in a retracted position where the foot 60 has been slideably moved in the opening 38 defined by the "U" shaped bend 36 of the brace 34 such that the tab 62 is disengaged from the "L" shaped tab 40, and the foot 60 has been pivoted relative to the opening 38. The second rod 48 in the retracted position will lie against the ironing board 22 (not shown in FIG. 2), so that the ironing board 22 can be stored with the apparatus 10 still attached. The article holder 66 is removed from the second brace 78 by raising the article holder 66 vertically, thereby removing the tangs 74 from the openings 82.
The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof and, accordingly, reference should be made to the appended claims, rather than to the foregoing specification, as indicating the scope of the invention. | An apparatus mounts on an ironing board for guiding a cord of an iron and providing a holder for an article. The article has a clamp section for releasably securing the apparatus to the ironing board. A cord support is pivotably attached to the clamp for supporting the electrical cord of the electrical appliance above the ironing board. An article holder is mounted to the clamp for holding an article. An electrical receptacle is carried by the clamp for receiving a plug of the electrical cord of the iron. | big_patent |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to buttonhole controlling devices for a sewing machine.
2. Description of the Prior Art
Buttonhole controlling devices which a sewing machine operator may use to select the length of a buttonhole to be sewn and which are effective to cause a machine when in a buttonhole mode to automatically sew a buttonhole of the selected length are well known. While such a device may prove effective to cause neat buttonholes to be formed in one type of material, it may not produce the desired result in other fabrics. This is due to the fact that different materials vary in the extent to which they slip relative to the feed dog of a machine during sewing. As a consequence, buttonholes may be formed in which the stitching fails to close or in which the stitching extends beyond the desired point of closure.
It is a prime object of the present invention to provide a buttonhole controlling device which can be rendered effective regardless of the type of material being sewn to cause buttonhole stitching to close without overlap.
SUMMARY OF THE INVENTION
The buttonhole controlling device of the invention includes a foot pad which attaches to a presser bar, and a travelling assembly having an initial position relative to the foot pad as defined by oppositely acting springs. The travelling assembly moves with work fed during the sewing of a buttonhole and includes a slidable member that may be positioned by a button for which a buttonhole is to be sewn. The slidable member positionable by a button carries a tab to actuate a tripping lever on the machine during movement of the assembly and cause the length of a buttonhole formed with the buttonhole device be limited to that suitable for the button inserted in the travelling assembly. An adjustable stop mounted on the travelling assembly engages the tripping lever to terminate the formation of a buttonhole. By properly positioning the stop, an operator can precisely define the closure point and so prevent the formation of an open buttonhole or one in which stitches overlap.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary head end elevational view of a sewing machine including the buttonhole controlling device of the invention;
FIG. 2 is a fragmentary plan view taken substantially on the plane of the line 2--2 of FIG. 1, and showing the travelling assembly on the device of the invention in an initial position;
FIG. 3 is a view similar to FIG. 2 showing the travelling assembly upon completion of a bar at the end of the first leg of a buttonhole;
FIG. 4 is a fragmentary perspective view showing the travelling assembly at the completion of the buttonhole; and
FIG. 5 indicates buttonhole stitches formed with the aid of the buttonhole device of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings, reference character 10 designates the head end of a sewing machine wherein a needle bar 12 is vertically reciprocable. A sewing needle 14 is affixed to the needle bar 12 for reciprocation thereby. The machine carries a presser bar 16 to which the buttonhole controlling device 18 of the invention attaches, and also a tripping lever 20. Buttonhole controlling device 18 is peculiarly adapted to accomplish the primary objective of the invention but is generally similar to the device disclosed in U.S. Pat. No. 3,877,403 of The Singer Co. and reference to such patent may be made for any details of construction not specifically described herein.
The device 18 controls the operation of the tripping lever 20 and the tripping lever controls flexible contacts 22a, 22b and 24a, 24b to cause the machine to sew a buttonhole when in a buttonhole mode. The particular manner in which the machine is constructed to cause a buttonhole to be sewn in response to the operation of the contacts 22a, 22b and 24a, 24b constitutes no part of the invention and is therefor not described herein. It is sufficient here to note that the machine operates as in U.S. Pat. No. 3,841,246 to cause top bar stitches a and left leg zig-zag stitches b constituting a first half of a buttonhole to be formed with the tripping lever in a forward position (away from the operator), and cause bottom bar stitches c and right leg zig-zag stitches d constituting a second half of the buttonhole to be formed with the tripping lever in a rearward position (toward the operator) (see FIG. 5). The machine may, for example, be constructed in the manner of the "TOUCH-TRONIC" 2001 electronic sewing machine manufactured and sold by The Singer Company.
Buttonhole controlling device 18 includes a foot pad 26, and also a travelling assembly 28 consisting of a work engaging shoe 30 and plate 32. Foot pad 26 attaches to a presser bar attachment 27 in a slot 34 provided at the end thereof to receive a pin 36 affixed in the foot pad. The shoe 30 includes rails 38 and 40 which form guide channels 42 and 44 for side edges 46 and 48 respectively of the pad 26 to permit relative sliding of the travelling assembly and foot pad. The work engaging shoe 30 and plate 32 are separable parts held in assembled relationship with a wall 47 on the plate extending upwardly through a slot 49 in the shoe.
The shoe 30 includes as a fixed part thereof, an anchor element 50 which is formed with a base 52. The base defines a shallow cavity 54 loosely accommodating a coiled end 56 of a flat spring 58 of which the other end is secured at 60 in foot pad 26. The base 52 is also provided in accordance with the invention with a horizontally extending helical spring 62 in a recess 64 where one end rests against an abutment 66. The other end of the spring 62 is engageable by a tab 68 on the foot pad 26. The two springs 58 and 62 define an initial position for the travelling assembly 28 relative to the foot pad 26. As shown, the anchor element 58 includes an upstanding abutment 70 which is formed with a "V" notch 72 adapted to engage and center one side of a round button 73, and includes a post 74 at the end of the base 52 remote from the "V" notch 72.
The shoe 30 is provided with a gaging element 76 which is formed with an upstanding abutment 78 and a set of rails 80 and 82 shaped to overlie and slide on the rails 38 and 40 respectively. Gaging element 76 may be shifted away from anchor element 50 to the extent permitted by abutment 78 engaging post 74. Abutment 78 is formed with a "V" notch 86 complemental to the "V" notch 72 in anchor element 50 for use in conjunction with the notch 72 for centering and locating a button therebetween.
A tab 88 for use in actuating tripping lever 20 is provided on rail 80 of gaging element 76. An adjustable stop 96 is also provided in accordance with the invention for use in actuating tripping lever 20 on rail 38 of the shoe 30. The position of actuating tab 88 with respect to adjustable stop 96 may be varied in accordance with the size of the button inserted between the "V" notches 72 and 86. As shown, the adjustable stop 96 includes a screw 98 having a threaded connection with a boss 100 which is affixed with a bracket 102 to rail 38. A knob 104 is provided on the screw 98 to facilitate turning by an operator. Tripping lever 20 extends in an operating position between tab 88 and screw 98 of the adjustable stop 96.
When buttonholes are to be sewn with the device 18, the button for use with such buttonholes is first placed between "V" notches 72 and 86 to position tab 88, and thereby establish the length of the buttonholes to be produced. A sample piece of the material to be sewn is located between the shoe 30 and plate 32. A buttonhole start line on the material is suitably located in an aperture 106 formed in the foot pad 26 and the presser bar is depressed with handle 106. The initial position of the travelling assembly 28 including the shoe 30 and plate 32 is defined by springs 58 and 62. Screw 98 is roughly adjusted by the operator to locate it in an intermediate position, such as to have it act against tripping lever 20, and cause the lever acting through a pivoted link 110 and pin 112 thereon to effect engagement of contacts 22a, 22b. With contacts 22a, 22b engaged, the machine is caused as soon as it is placed in a buttonhole mode to sew the top bar stitches a of FIG. 5 through aperture 106 in the foot pad 26. Following formation of the top bar stitches a, the machine sews left leg zig-zag stitches b as the travelling assembly 28 and the material being sewn is fed in a forward direction by feed dog 108. Contacts 22a, 22b open as the travelling assembly moves forward, but the machine continues to operate without change until tab 88 comes into engagement with the tripping lever 20 and disposes it to cause flexible contact 24a to engage flexible contact 24b whereupon the machine is first caused to sew bottom bar stitches c. Following formation of the bottom bar stitches, the machine sews right leg zig-zag stitches d as the travelling assembly moves, in the reverse feed direction (toward the operator). Contacts 24a, 24b are opened and the machine continues to operate without change until screw 98 engages lever 20 whereupon the sewing operation ceases.
After the completion of a buttonhole in the sample material, if the operator observes that the buttonhole stitches aren't closed by the right leg or that the right leg stitches extend beyond the top bar stitches, the operator can remedy the deficiency by adjusting screw 98 until the machine sews a perfect buttonhole. When the buttonhole is open, screw 98 is adjusted with knob 104 to retract the screw relative to lever 20, and when there is an overlap the screw is advanced with respect to lever 20. When a perfect buttonhole is obtained in the sample material, the operator can proceed to sew buttonholes in the garment of the same material. Whenever buttonholes are to be sewn in another garment of a different type of material the screw 98 is readjusted while working with a sample of the new material before buttonholes are sewn in the new garment to thereby compensate for possible slippage in different amounts of the different materials with respect to the travelling assembly 28.
It is to be understood that the present disclosure relates to a preferred embodiment of the invention which is for purposes of illustration only, and that various modifications may be made therein without departing from the spirit and scope of the invention as defined in the appended claims. | A buttonhole controlling device for use in causing a sewing machine to form a buttonhole of a selected length, and including means for effecting a reversal in the direction in which material is fed under a sewing needle as required for the formation of a final leg of the buttonhole, is provided with an adjustable stop enabling an operator to precisely define the end position of the final leg and so assure closure of the buttonhole without overlap. | big_patent |
This application is a continuation of application Ser. No. 919,223, filed Oct. 15, 1986, now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to an apparatus for treating a dyed or printed textile web with a liquid such as a washing or rinsing solution.
German Patent No. 830 040 discloses in principle a technique of spraying a treatment solution onto a moving textile web at several points spaced one behind the other along the direction of transport of the web, most of the solution applied at any particular spray station being removed from the fabric by suction before additional solution is applied to the web at a further point. In German Patent No. 830,040, the textile web is conducted freely, under small looping angles, along successive spray and suction pipes or over a suction drum, over the circumference of which drum spray pipes acting radially inwardly are distributed. Such a treatment of a fabric requires that the web have a minimum textile strength. Accordingly, the treatment is unsuitable for material such as knitted fabrics.
As disclosed in German Patent Document (Offenlegungsschrift) No. 23 62 109, an endless sieve belt passes over a pair of guide drums disposed at the same horizontal level, the cloth being spread out on an upper section or segment of the belt so that the cloth can be guided on the belt while the cloth is lying flat and completely slack. Above the upper section of the sieve belt, spray pipes are arranged for applying a washing or rinsing liquid to the cloth lying on the belt. Subsequently, the applied liquid, laden with dirt or dye residues, is removed by suction through the cloth and through the sieve belt.
The distance between the point of application of the liquid and the suction point is relatively short, with the consequence that the liquid has little time to act on the substances which are to be removed from the web.
German Petty Patent (Gebrauchsmuster) No. 17 40 815 discloses a boot-like water-filled washing chamber in which chamber the fabric is placed in a stacked configuration in order to lengthen the contact time of the washing liquid with the substances to be removed from the fabric web. This procedure, however, is unsuitable for many applications, exemplarily in the case of knitted materials, such knitted materials being difficult to draw out of the stack because of the sensitivity of the material to tension. The solution of the Gebrauchsmuster is also unsuitable in the case that the web is provided with printed matter, smudges in the printed matter arising upon stacking of the web.
An object of the present invention is to provide an improved apparatus of the above-described type.
Another, more particular, object of the present invention is to provide such an apparatus in which a washing or rinsing may be adequately effectuated without maintaining the textile web in a stacked configuration.
SUMMARY OF THE INVENTION
An apparatus for treating a dyed or printed textile web with a liquid comprises, in accordance with the present invention, a conveyor, a liquid applicator, a suction device and a dwell stretch. The conveyor includes an endless sieve belt for transporting the textile web along a predetermined substantially horizontal path. The applicator is disposed at a first station along a path for applying the liquid to the web during motion thereof along the path. The suction device is disposed at a second station along the path at a point downstream of the first station for removing the liquid from the web by a suction process during motion of the web along the path. The suction device preferably extends transversely to the web and to the belt and is disposed below and substantially juxtaposed to an upper section of the belt. The dwell stretch is disposed between the applicator and the suction device for conducting the textile web in a spread-out condition and in a single layer through at least one dwell loop.
In a fabric treatment apparatus in accordance with the present invention, the action time of the applied liquid on the substances to be removed from a fabric or textile web is lengthened. In one kind of application, a printing thickener has more time to swell. Because of the greater time that the washing or rinsing liquid has to act on the substances to be removed from the web, a surprising improvement of the washing effect can be achieved. Moreover, owing to the spread-out condition and the single-layer configuration of the textile web in the dwell loop, the tension in the textile web can be maintained at a small level.
In the case of printed material, a fabric treatment apparatus in accordance with the present invention is especially advantageous in that effective washing is possible without soiling a white background, inasmuch as the washing solution is spread onto the textile web and the cloth is neither placed into a stacked configuration nor run through a vat or the like.
A preferred area of application of the invention is so-called "soilage washing," because considerable amounts of soilage can be removed at relatively little expense. A fastness treatment as such may follow a washing operation in accordance with the invention.
In a particular embodiment of a fabric treatment apparatus in accordance with the present invention, the dwell stretch device is formed by an air pass, wherein the textile web is completely free of support or guiding elements at least along major portions of the dwell stretch or loop and is accordingly accessible to the atmosphere at all sides. An air pass may be formed in a known manner by a plurality of freely rotatable rollers arranged in two planes above the upper section of the sieve belt for guiding the web in a plurality of vertically extending loops above the upper section of the belt.
In an alternative embodiment of a fabric treatment apparatus in accordance with the present invention, the dwell stretch includes at least one freely rotatable drum disposed above the upper section of the sieve belt. The dwell loop extends around the drum. The dwell stretch further includes at least two rollers disposed laterally adjacent to one another below the drum for guiding the web to and from the drum. This particular embodiment of the fabric treatment apparatus in accordance with the invention is especially suitable for certain less resistant materials such as knitted fabrics. The web is conducted along a meander path from the belt path and back to the belt. The drum and rollers enable the textile web to be guided with particularly little tension.
A fabric treatment apparatus in accordance with the present invention can have a compact construction, particularly if the textile web is guided back from the dwell loop to the sieve belt at a point downstream and closely adjacent to the point where the web leaves the belt.
The suction device is advantageously disposed near the point of return of the web to the sieve belt. The suction device causes the textile web to adhere to the belt and to be entrained thereby. This entrainment of the textile web by the belt is sufficient to guide the web over several rollers not exhibiting any buoyance, or over drums, without any appreciable longitudinal tensile stresses occuring in the web.
Advantageously, in the second embodiment, the drum is made of a sieve material. However, other drum designs such as slats may also be utilizable in accordance with the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partially schematic side elevational view of a fabric treatment apparatus in accordance with the present invention.
FIG. 2 is a partially schematic side elevational view of another fabric treatment apparatus in accordance with the present invention.
DETAILED DESCRIPTION
As illustrated in FIG. 1, a fabric treatment apparatus 100 comprises a scaffold type machine frame 1. A first guide drum 2 is rotatably mounted to machine frame 1 at an inlet side thereof, while a second guide drum 3 is rotatably mounted to machine frame 1 at an outlet side thereof. Guide drums 2 and 3 have essentially the same diameter and are arranged at approximately the same height above a floor base. An endless sieve belt 4 partially surrounds guide drums 2 and 3, sieve belt 4 having an upper section 4' extending approximately horizontally from guide drum 2 to guide drum 3. Guide drum 3 is driven to move upper section 4' of belt 4 from left to right in the drawing. Guide drum 2 is adjustable for tensioning sieve belt 4, as indicated by an arrow.
A gas-permeable textile web 10, arriving at fabric treatment apparatus 100 from a pretreatment apparatus such as a dying unit or a printing unit (not illustrated), is guided via a tension-compensating roller 5 into apparatus 100 over a full-width roller 6 and immediately thereafter onto sieve belt 4. Textile web 10 is guided in a single layer in a spread-out state and lies tensionless on upper section 4' of sieve belt 4. Textile web 10 then passes a spray pipe 7 having spray nozzles 8 distributed over the width of web 10, a washing or rinsing liquid being applied via nozzles 8 to the top side of textile web 10 substantially uniformly over the width thereof.
Subsequently, while being maintained in a single-layer spread-out state, textile web 10 passes through a dwell stretch W in the form of a so-called air pass 9. Air pass 9 includes a trio of lower rollers 11 closely juxtaposed to but not engaging each other and a pair of upper rollers 12 arranged at a distance 13 above lower rollers 11. Textile web 10 is guided between the lower rollers 11 and upper rollers 12 to form a pair of vertically extending dwell loops. Rollers 11 and 12 are all rotatably mounted to machine frame 1 and are entrained by textile web 10. In the short horizontal distance between the outer rollers of the lower trio of rollers 11, textile web 10 traverses a considerable dwell stretch corresponding to a multiple of distance 13, depending on the number of vertical dwell loops 14. Distance 13 is advantageously 1 to 2 meters.
As soon as textile web 10 again rests horizontally on upper section 4' of sieve belt 4 after passing the last roller of the lower trio of rollers 11, the web passes a suction device 15 provided with a suction pipe and a suction slit 16. Suction device 15 removes by suction, through textile web 10 and upper section 4' of sieve belt 4, the liquid applied by spray pipe 7 together with the greater part of the substances to be eliminated from the textile web.
Spray pipe or liquid applicator 7, air pass 9 and suction device 15 together form an assembly unit 17. As illustrated in FIG. 1, two further assembly units 17' and 17" are spaced from one another and from assembly unit 17 along the path defined by upper sieve belt section 4'. Assembly unit 17' comprises a liquid applicator 7', a dwell stretch W' in the form of an air pass 9' and a suction device 15'. Air pass 9' includes four lower rollers 11' and 3 upper rollers 12', lower rollers 11' being spaced distance 13 from upper rollers 12'. Assembly unit 17" comprises a liquid applicator 17", a dwell stretch W" in the form of an air pass 9" and a suction device 15". Air pass 9" comprises a set of four lower rollers 11" spaced distance 13 from a set of three upper rollers 12". Textile web 10 passes through three dwell loops 14' and another three dwell loops 14" in assembly units 17' and 17", respectively.
A first set of catch plates 18 are provided below upper sieve belt stretch 4' and another set of catch plates 19 are provided below the lower section of sieve belt 4 for collecting liquid and returning it for recycled usage.
Upon leaving guide drum 3, textile web 10 passes over a tension-compensating roll 20 and is further processed. Further processing may include exemplarily a fastness treatment.
As illustrated in FIG. 2, another fabric treatment apparatus 200 in accordance with the present invention has many of the same elements as fabric treatment apparatus 100. The same elements are designated by the same reference numerals in the drawing. Apparatus 200 differs from apparatus 100 in the design of the dwell stretch.
Apparatus 200 comprises three dwell stretch assemblies 27, 27' and 27" spaced from one another along the horizontal path taken by upper sieve belt section 4'. Assembly 27 includes first liquid applicator or spray pipe 7, dwell stretch W in the form of a sieve drum 21, and suction device 15. Sieve drum 21 is rotatably mounted to machine frame 1 at a distance above the plane of upper sieve belt section 4'. A pair of small-diameter guide rollers 22 are disposed below sieve drum 21 symmetrically with respect to a vertical plane passing through the axis of rotation of drum 21. Guide rollers 22 are spaced from one another along the path taken by upper sieve belt section 4'. Each guide roller 22 is closely juxtaposed on a lower side to upper sieve belt section 4' and on an upper side to drum 21.
The direction of motion of textile web 10 about drum 21 is indicated by arrows. The textile web passes partially around an upstream guide roller 22, whereby the direction of motion of the web is substantially reversed. The web is then guided around sieve drum 21 and deposited again on upper sieve belt section 4' upon passing partially around a downstream guide roller 22 and again reversing its direction of motion. Textile web 10 accordingly travels between guide rollers 22 over a meander path corresponding almost to the entire circumference of sieve drum 21.
Upon being deposited on upper sieve belt section 4', textile web 10 is subjected to suction from suction device 15, as described hereinabove with respect to FIG. 1. By the deposition of textile web 10 on sieve belt 4 and additionally by the action of suction device 15 disposed under upper sieve belt section 4' and closely juxtaposed thereto (suction device 15 causing textile web 10 to adhere to sieve belt 4 by suction), textile web 10 is taken along by sieve belt 4 and in turn entrains sieve drum 21 and guide rollers 22. Guide rollers 22 are rotatably mounted to machine frame 1 and can turn easily so that no appreciable tensions arise in the textile web.
Dwell stretch assembly 27' includes liquid applicator 7', dwell stretch W' in the form of a sieve drum 21', and suction device 15'. Two guide rollers 22' are disposed below sieve drum 21' on opposite sides of a vertical plane passing through the axis of rotation of sieve drum 21'. Guide rollers 22' are closely juxtaposed on a lower side to upper sieve belt section 4' and on an upper side to sieve drum 21'. Drum 21' and guide rollers 22' are rotatably mounted to machine frame 1 so that textile web 10 can travel along a meander path defined by guide rollers 22' and sieve drum 21'.
Assembly 27" comprises liquid applicator 7", dwell stretch W" in the form of a sieve drum 21", and a pair of guide rollers 22", and suction device 15". Sieve drum 21" and guide rollers 22" are rotatably mounted to machine frame 1, rollers 22" being closely juxtaposed on a lower side to upper sieve belt section 4' and on an upper side to sieve drum 21". Guide rollers 22" are closely juxtaposed to but spaced from one another along the path of upper sieve belt section 4' and are located symmetrically with respect to a vertical plane passing through the axis of rotation of sieve drum 21".
Although the invention has been described in terms of particular embodiments and applicaitons, one of ordinary skill in the art, in light of this teaching, can generate additional embodiments and modifications without departing from the spirit of or exceeding the scope of the claimed invention. Accordingly, it is to be understood that the drawings and descriptions herein are proffered by way of example to facilitate comprehension of the invention and should not be construed to limit the scope thereof. | In a fabric treatment apparatus for applying a washing or rinsing liquid to a dyed or printed textile web, the web is transported by a sieve conveyor belt along a horizontal path. Spaced from one another along that horizontal path are several liquid applicators or spray pipes. Associated with each spray pipe is a respect dwell stretch and a suction device, the dwell stretch being located downstream of the respective liquid applicator and upstream of the respective suction device. The dwell stretch includes either two sets of rotatable rollers spaced a distance from one another or a rotatable sieve drum. | big_patent |
CROSS REFERENCE TO RELATED APPLICATIONS
This is a division of application Ser. No. 445,501, filed Feb. 25, 1974, now U.S. Pat. No. 3,937,043.
This application contains, in its description, matter common to co-pending cases Application Ser. Nos. 445,028, 445,503 and 445,504, of common assignee with the present application.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an air flow system for a dry cleaner for inducing ambient air to flow into the access opening of the machine whenever the door is opened. Such systems have previously been referred to as air exhaust systems; however, the present invention is particularly adapted to provide the air flow without exhausting the tubs.
2. Description of the Prior Art
As a safety feature in dry cleaning machines, an air flow system is provided for drawing ambient or room air in through the access opening to the interior of the machine whenever the door to the machine is opened. This air flow minimizes the escape of toxic solvent vapors out the access opening so that the user will not be subjected to such vapors when loading or unloading clothes from the machine. Heretofore, this air flow was commonly induced by the fan or blower which also was used during the drying cycle to circulate heat through the tubs. Also, to some extent, there were common ducts for each system with a diverter valve for determining whether the air would flow through the recirculating path or to an exhaust outlet. In machines using a relatively inexpensive solvent having normal volatility, the loss of residual solvent vapors from the interior of the tubs and the common ducts was of limited concern. Thus, the air flow system for inducing ambient air to flow in through the door was typically included in the tubs, exhausting the tubs of the residual solvent vapors therein and thus losing them to the atmosphere.
The use of a cleaning solvent which is substantially more expensive and of greater volitality required, for economic reasons, that the residual solvent vapors remaining in the tubs and air recirculating system at the end of the cleaning cycle not be exhausted to atmosphere but, of necessity, retained within the confines of the machine. However, it remains necessary to induce an air flow in through the access whenever the door to the machine is opened.
SUMMARY OF THE INVENTION
The dry cleaning machine of the present invention provides an air flow system for bringing ambient air into the access opening whenever the door is opened which is exclusive of the air recirculating system and substantially reduces exhausting the residual solvent vapors from the tubs. Thus, a separate intake fan and duct is provided with the duct interposed between the access opening of the machine housing and the open ends of the interior tubs, and includes a normally closed valve so that during normal operation of the machine the separate intake system is isolated from the solvent vapors developed during the cleaning cycle. In response to the access door being opened, the intake fan is energized and the valve is opened so that air is drawn into the access opening and directly into the interposed duct with only that vapor generally immediately adjacent the open end of the tubs commingling with the intake air and lost to atmosphere. However, for the most part, the vapors within the tubs are retained and the loss of solvent is minimized.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective schematic drawing of the dry cleaner primarily showing the solvent distributing system and the air distributing system of the present invention;
FIG. 2 is a perspective schematic drawing similar to FIG. 1 for primarily showing the air distributing system and a refrigeration system for solvent vapor recovery;
FIG. 3 is a timer cycle chart indicating the timer-energized components during each portion of the dry cleaning cycle; and,
FIG. 4 is a simplified schematic wiring diagram showing the machine controls.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring initially to FIGS. 1 and 2 it is seen that the dry cleaner 2 of the present invention is generally of known construction in that it includes a pair of nested tubs 4, 6 having a common horizontal access with the outer tub 6 generally stationarily supported and the inner tub 4 rotatably supported, and an outer cabinet 8 (shown in dotted lines in FIG. 1) having an access opening in alignment with the open end of the tubs and supporting a front opening door 9 for access to the inner tub 4. The cabinet 8 encloses the other operative elements of the dry cleaner such as the drive motor (see FIG. 4) coupled through a well-known belt and pulley drive to the inner tub 4 for either reversibly slowly rotating the tub or spinning the tub at a relatively high speed. Also included is a pump 24 for pumping the dry cleaning solvent from a storage tank 20 into the tub 6 through a filter 14 in the housing 36, and back into the storage tank and a blower 16 for circulating heated air through the tubs for drying the clothes.
The forward concentric openings of the tubs 4 and 6 are spaced from the wall of the cabinet having the opening to accommodate therebetween a header chamber 11. This chamber has opposed walls 11a defining concentric openings which in turn are in alignment with the cabinet opening and tub openings respectively to provide an access opening therethrough for the clothes. The walls of the chamber are also sealingly attached to the cabinet structure and outer tub 6, with the periphery of the forward opening bounded by a forwardly extending flange for sealingly engaging the inner face of the door when in a closed position. The upper portion of the chamber above the openings defines a plenum into which the air from the air blower is directed so that it enters the tubs at the forwardmost portion thereof, and also from which exhaust air is drawn as will be explained later.
The complete operation of the electrical components dictating the type of operation being performed is controlled through a well known timer mechanism 18 generally enclosed adjacent the rear of the housing in an area generally inaccessible to the customer/user.
The operative cycle of such a machine, maintained normally in a stand-by condition, includes, after the cleaning cycle is initiated, a washing portion wherein the solvent is delivered to the tub 6 during slow speed rotation thereof so that the clothes are randomly moved about within the solvent, a drain portion wherein the solvent is drained from the tub 6, a spin or centrifuging portion wherein the solvent is extracted from the clothes, and a drying portion when the clothes are again randomly moved about within the tub 4 in the presence of circulating heated air.
The present invention is better described with specific detail to the separate circulating systems within the machine. In this regard each system will be described as it functions through the various distinct portions of the complete cleaning cycle.
SOLVENT FLOW SYSTEM (FIG. 1)
Stand-by
Anytime the machine is not being used it is in a stand-by condition ready for use by merely closing the access door and depositing the appropriate coins. While in the stand-by condition there is no flow of the solvent within the machine, with the solvent being stored in tank 20.
Fill and Wash
After the clothes are loaded into the inner tub 4, the cleaning cycle is initiated, as by closing the access door 9 and depositing the correct change, which energizes the solvent pump 24. This pumps the solvent from the storage tank 20 through pump inlet line 22 into pump 24, hence to discharge pipe 26 and in one side 28A of a diverter valve 28 normally oriented to direct the flow into line 30 through nipple 29.
From line 30 the solvent passes through another diverter valve 32 which normally directs the flow into pipe 34 which is the inlet pipe of a housing 36 enclosing a pair of pleated paper and charcoal filters (not shown). After passing through the filters, the solvent exits the housing through outlet 38 which leads through a sight-glass 40 and manual valve 42 into leg 44 of a T-connector 46. The opposite leg of the T-connector leads to a oneway valve 48 which is set up to prevent flow therethrough from the connector. Thus, the solvent goes to another diverter valve 50 normally directing the flow into yet another diverter valve 54 through a nipple 52. Valve 54 normally directs the flow into pipe 56 which leads into the outer tub 6.
Once the tub 6 fills to a predetermined level, any further solvent coming into the tub causes the solvent to flow out the tub 6 through the overflow line 60. It is to be noted that a drain or dump line 62 also leads from the tub 6, but as this line is closed by a motor drive valve 64 at this time, the solvent can exit the tub only via line 60.
Line 60 also has a motor driven overflow valve 66 which at this time is open permitting flow of the solvent into line 68 connected to a housing 70 containing a button trap (as is well known in the art) enclosing a perforated container 72 interposed between the inlet and the outlet pipe 74 leading back to the storage tank 20.
This recirculation of the solvent from the storage tank through the filters, into the tubs, through the button trap, and back to the tank, is continuous throughout the fill and wash portion of the cycle.
Dump and Spin
At the termination of the wash cycle, although the clothes tub 4 continues to tumble the clothes, the above-described flow circuit is altered to provide two separate solvent flow paths. The first provides continuous filtration of the solvent by continuing to pump the solvent from the tank 20 through the filters via the route described above with the exception being that valve 54 has now been energized and directs the solvent into line 76 which leads directly back to tank 20. Thus, no more solvent enters the tubs. The other path dumps the solvent already in the tubs into the tank 20. This is done by opening valve 64 of line 62 for flow therethrough into another inlet pipe 78 of button basket 72 before flowing through outlet pipe 74 to the storage tank 20. This flow path is maintained all during the drain and subsequent spin portion of the cycle. Also, for purposes of air pressure balance through the solvent distributing system, overflow valve 66 remains open during this portion of the cycle.
Tumble Dry With Heat
During this portion of the cycle the solvent continues to flow through the filtering cycle above described; however, valves 64 and 66 are closed, which in conjunction with valve 54 closing the solvent inlet line to the tub, (as is the case with the filtration flowpath utilized), the solvent flow system is isolated from any evaporative air circulated during the dry cycle.
Last Minute Of The Cycle
During the last minute of the cycle, the solvent which has been flowing in one direction through the filters, is caused to flow through the filters in a reversed direction in an operation known as "backwash". (Again see the U.S. Pat. No. 3,253,431 of common assignee.)
Thus, as before, the solvent is drawn from tank 20 through pipe 22 into pump 24 and discharged to line 26 into valve 28. This diverter valve has now been energized to direct the flow into line 88 and into valve 50 which also has been energized to direct flow into leg 44 of connector 46, thence through manual valve 42, sight-glass 40 and into the outlet 38 of the filter housing 36.
The solvent exits the housing 36 through inlet 34 and into diverter valve 32 which is energized to divert the solvent into line 82 leading to the top of the button tank 70 which, as is also well known, houses a backwash bag which filters particles from the solvent as it passes therethrough into the button basket for return to the tank 20 via line 74.
A filter housing breather line 86 connects the upper end of the filter housing 36 with the button basket tank 70 to bleed any air entrapped therein out of the housing and into a suitable place. Any solvent that may flow therethrough goes directly to the button tank 70 and back to the storage tank 20.
It is important to note that valves 54, 64, and 66 still maintain the solvent distributing system isolated from the circulating drying air.
To complete the solvent flow system, a safety line 132 connects the top of the button tank 70 with a line 128 (a solvent vapor handling line to be explained subsequently) leading directly into storage tank 20. This line 132 accommodates the solvent flow in the event the button trap 70 becomes clogged to the extent that return flow to the tank 20 through line 74 is blocked. Thus, under this condition, the button trap would fill with solvent to the line 132 which would deliver it back to the tank 20 at a rate capable of accommodating the pump capacity during the filtering portion of the cycle.
AIR FLOW SYSTEM (FIG. 2)
As previously explained, the header chamber 11 is attached to the outer tub 6 at the tub's forward opening. This header chamber 11 thus is in air-flow communication with the inner tub 4 through the forward facing opening of the tub. The header chamber has attached thereto a pair of airflow hoses 118 and 122. Another air hose 96 is attached to the stationary outer tub 6 at some point axially remote from the header chamber 59. Each hose in turn is associated with an electrically energized oneway valve 90, 92, and 94 respectively, for controlling the flow through these hoses, these being the only airflow ingress or egress lines connected to the tubs.
Stand-By With Access Door Closed
During this time there is no airflow as no blower is energized and valve 90, 92 and 94 are normally closed. However, should the door become open, a door switch immediately energizes valve 92 and an exhaust blower 120. Thus, it is seen ambient room air is drawn through the front opening and immediately drawn into the upper portion of the header chamber 11 with minimal penetration into the interior of the tubs so that the solvent vapors within the tub are not exhausted while the air is being drawn through the front opening to prevent the user, when loading or unloading clothes, from encountering solvent vapor fumes.
Fill And Wash
Again there is no airflow during this portion of the cleaning cycle as valves 90, 92 and 94 remain closed and no blower is energized. Thus, during this portion of the cycle the solvent in the tub is not exposed to any circulating air.
Drain And Spin
During the drain portion of the cycle, valve 90 associated with the air inlet side of header chamber 59 and valve 94 associated with the air outlet side of the tub 6 are both open to assist in balancing the air pressure throughout the interior of the machine (with no blower being energized) as the solvent is drained from the tubs. However, once the drain portion is completed and the inner clothes tub 4 is energized to spin, all valves 90 and 94 are again closed. This again isolates the air within the tubs and prevents any air circulation through the air distributing system which could be induced by the spinning tub even though no blower was energized if such valves were open.
Elimination of the airflow through the clothes during spin by isolating the tubs as above described is important with respect to minimizing the undesirable phenomena associated with dry cleaning and referred to in the trade as "streaks and swales". These are darker areas in the form of spots and lines that form in the clothes when certain areas dry faster than others and before the solvent has a chance to be distributed generally equally throughout the clothes. Thus, in these areas, generally adjacent the creases or folds in the clothes which are dried quite rapidly, a concentration of non-volatile residue (N.V.R.) carried by the solvent as a result of cleaning the clothes, is present which is highly visible as darker streaks at the interface of the faster dried areas and the subsequently dried area of the clothes.
It logically follows that the greater the volatility of the solvent, i.e. the more readily the solvent vaporizes, the more likely it will be for uneven drying to occur, forming the streaks and swales. The uneven drying as accenuated by the spinning tub, which in addition to maintaining the clothes in a fixed position by virtue of the centrifugal force, also normally induces an air circulation through the tub, created by the high speed spinning of the clothes and tub acting as a blower.
It has been found that the formation of the streaks swales can be greatly reduced and even eliminated by preventing airflow through the tub during the spin cycle. This, in addition to decreasing the vaporization of the solvent from the exposed surfaces of the clothes due to air movement, prevents escape of the vaporized solvent, thereby permitting the vapor pressure within the tub to increase somewhat which itself retards further vaporization. Thus, although a solvent having a higher degree of volatility is used in this machine, the formation of streaks and swales is greatly reduced by having valves 90 and 94 closed during centrifugal extraction.
Tumble Dry With Heat
One minute after the start of the drying portion of the cycle wherein the tub 4 is again reversibly driven at a tumble speed, valves 90 and 94 are opened. This initial minute with the above valves closed permits the clothes to be in a tumbling mode before the flow of drying air is initiated. This is in furtherance of preventing rapid drying of selective areas for eliminating streaks of swales by letting the clothes move randomly about before being subjected to the rapid drying affects of the hot air.
Once the valves 90 and 94 are opened and blower 16 energized, the air and vapor mixture exits the tubs 4, 6 through hose 96 which leads into a lint box 98 having a lint screen 100. After passing through the lint box, air goes through valve 94, and then to hose 102 of the inlet of blower housing 104 enclosing the blower 16. From there the air/vapor mixture goes through hose 106 and into condenser housing 108. Condenser housing 108 contains the evaporator coils 110 of a refrigeration unit (to be described) which condense the solvent vapor from this air and vapor mixture.
The air exits housing 108 through hose 112 which leads into a heater box 114 enclosing a cast aluminum finned resistance heater 116, where the temperatures of air is elevated to a predetermined level. (It is noted in FIG. 3 that the heater has been energized a sufficient length of time prior to the flow thereover to insure the heater is at the elevated temperature when the airflow through the tub 4 begins.) From the heater box 114 the heated air flows into inlet valve 90 and thence into the inlet of header 59 to flow through the clothes in the tub 4, vaporizing the solvent from the clothes and repeating the closed circulation path described continuously through the dry portion of the cycle. At the termination of the dry portion of the cycle the blower 16 stops, valves 90 and 94 close and the front opening access door is permitted to be electrically unlocked by manual depression of a door opening switch. (It should be pointed out that once the cycle has been initiated the door is mechanically locked in a manner that can only be unlocked through the electrical energization of a solenoid that is prevented from being energized until the cycle is complete and subsequently described with reference to FIG. 4.)
Clothes Removal
Once the dry portion of the cycle is completed as above described, the machine is no longer controlled by the timer but is in a stand-by condition ready to repeat a cleaning cycle. However, for removal of the clean clothes, the access door must be open. And, as previously explained, anytime the door is open an exhaust fan 120 is energized through a door switch 140 (see FIG. 4) along with exhaust valve 92, also energized through the door switch 140, being opened. Thus, air is forced to enter the front opening, flow directly into the header chamber 11, through valve 92 attached thereto and into the blower 120. From the blower the air flows through hose 122 which in turn is to be connected to a venting system for the building housing the dry cleaner.
The airflow with the door open is thus limited to an exit path that is exclusive for exhausting and does not cause air to flow through the interior of the tubs 4, 6 thus minimizing the loss of solvent vapor to the exhaust. Also, the exhaust, to satisfy established requirements, causes air to flow through the door opening at a minimum rate of 100 linear feet per minute.
SOLVENT VAPOR HANDLING (FIG. 2)
During the fill portion of the cycle, the air in the tubs 4, 6 is displaced by the incoming solvent. Also, the warmer surfaces of the tubs cause some of the incoming solvent to vaporize. The closed door prevents this vapor from escaping through it and with the valves 90 and 94 closed, the air/vapor mixture is forced (by pressure) into hose 96 leading to lint box 98.
An exit hose 124 leads from the lint box to an expandable closed impervious bag 126, preferably plastic and housed in a container (not shown) located in the upper portion of the machine. The bag expands to accommodate and retain the air-vapor mixture. This bag keeps the pressure within the machine within low enough limits such that positively sealing the machine against the existing pressure to prevent leakage does not become prohibitively expensive as it would if the solvent vapor remained in the confines of the tub and attached hoses. In practice the pressure within the machine tends to stabilize at approximately one-half psi as opposed to approximately ten psi without the bag.
A safety release valve 130 is interposed in line 124 and adjusted to open under a somewhat greater pressure than one-half psi to insure that the internal stays within an acceptably low limit. However, under most circumstances valve 130 will not be required to open.
During the wash portion of the cycle, the vapor pressure within the tubs and line 96 tends to stabilize so that there is minimal air/vapor movement. Also, during the dump portion of the cycle, even though valves 90 and 94 are open, there is very little air/vapor flow from the bag 126 as the increasing volume in the tubs decreases the vapor pressure which in turn permits more solvent to vaporize to fill this space. The valves 90 and 94 being again closed for the spin portion of the cycle prevent air/vapor flow from the bag.
However, during the dry portion of the cycle with valves 90 and 94 open, the air is circulated as previously described. It is noted that line 24 is on the suction side of recirculating blower 16 so that with the blower 16 energized, the air/vapor mixture in the bag, being at a greater pressure and at an elevated position with respect to the suction inlet to the blower, is forced back into the flow stream via the lint box 98, until the bag 126 is evacuated. The vapor in this air/vapor mixture is then recovered in the same manner as the vapor driven from the clothes during the drying operation is recovered. The bag is evacuated well before the termination of the drying operation.
The relatively warm ambient temperature causes some of the solvent in the storage tank 20 to vaporize. This vapor is removed from the tank (to prevent pressure buildup therein) by a breather line 128 leading to condenser box 108. As the air passage through the condenser box 108 is blocked by valves 90 and 94 during all portions of the cycle except drain and dry, the box 108 and the hoses connected thereto act like a chamber providing additional volume to accumulate and retain the vapors. However, during this time, should the pressure increase beyond an acceptable level, (i.e. somewhat less than one-half psi) the vapors can by this pressure, be forced through line 106, backwards (in relation to the normal direction of flow) through recirculating fan 16, into hose 102. This pressure is then on the back face of closed valves 94 which is oriented to prevent flow in the other direction, but with back-pressure thereon, opens sufficiently for the vapors to leak through it and into box 98. From there the vapors go through line 124 for retention in the expandable bag 126 for subsequent reclamation as previously described.
During the drain portion of the cycle, the vapors generated in the tank 20 and directed to the condenser housing 108 are permitted to flow through the heater box 114 and into the tubs 4, 6 through the then open valve 90 for subsequent reclamation during the dry portion of the cycle, whereas during the dry portion, when the evaporator 110 is operating, the vapors directed into the condenser box 108 from either the tub or the tank are condensed.
In addition to condensing solvent vapor, the evaporator 10 in the condenser housing also condenses water vapor evaporated from the clothes during the dry portion of the cycle. This water/solvent mixture is directed from the condenser housing 108 by gravity flow through line 134 to the water separator housing 136 where, because of the difference in the specific gravity between the two liquids, the solvent can be removed from the water by lines exiting the separator at different levels as is well known in the art. Thus, the water goes through the separator 136 through line 138 into a closed container 140 for intermittent manual dumping. The solvent exits the housing 136 through line 142 to return to the storage tank 20.
REFRIGERATION SYSTEM (FIG. 2)
Stand-by
A compression-type refrigeration system is provided in the dry cleaner for condensing the vapors in the condenser box 108 and also for maintaining the liquid solvent in the storage 20 at a predetermined temperature to minimize the vaporization therein. The system is best seen in FIG. 2 and operates to cool the storage tank under all portions of the cycle except the drying portion. Thus, the description for stand-by includes these other portions of the cycle.
Thus, whenever the thermostat 141 within the tank 20 exceeds a predetermined limit (80°F) the refrigeration unit is energized with cooling directed to the evaporator coil 144 in the storage tank 20. In the system shown the refrigerant flow path includes a compressor 146 with a compressed refrigerant directed therefrom through line 148 to refrigerant condenser 150, accumulator 152, filter 154 and sight-glass 156 to T-connector 158. Of the two lines 160 and 162 leading from the T-connector 158, line 160 contains a normally closed valve 164 which thus prevents flow therethrough. However, line 162 contains a normally open valve 166 permitting the refrigerant to flow into line 168 leading to expansion valve 170 and evaporator coils 144 in the storage tank 20. From there the refrigerant is directed back to the compressor 146 through line 172 and T-connector 174. Once the solvent in the tank has been cooled to around 75°F, the refrigeration system is deenergized, but ready to repeat the cycle whenever the temperature exceeds 80°F.
Dry
During the dry portion of the cleaning cycle the refrigeration unit is continuously energized through a switch 143 (See FIG. 4) controlled by the timer. At this time the refrigerant flow from the compressor 146 is identical to that described above until it reaches the T-connector 158. The flow path from there is altered by the normally closed valve 164 being energized to an open position and the normally open valve 166 being energized to a closed position. Thus, the refrigerant is directed into evaporater coil 110 of the condenser housing 108 for continuous condensing of the solvent vapors passing therethrough during this time, and maintaining a substantially fixed temperature therein over the varying load conditions. From there the refrigerant 146 passes through line 176 leading to T-connector 174.
It is noted that during the dry portion of the cycle, the temperature of the solvent in the storage tank 20 can exceed the 80°F temperature without refrigeration being directed thereto. However, as this dry portion is a relatively short-term operation, the temperature rise is never too much beyond the 80°F and also the increased rate of vaporization is accommodated through the breather line 128 directing the vapor to the condenser housing where it is condensed and returned to the storage tank, as previously explained, as relatively cool solvent.
Further, as the refrigeration unit is sized in accordance with the heat removal required of it during the drying portion of the cycle (this being the greatest load it must accommodate) its refrigeration capacity is greatly in excess of that needed to maintain the solvent within the predetermined temperature range during all other portions of the cycle. Thus an alternative refrigeration control system would be to eliminate the normally closed valve 164 in line 160 and make valve 166 (previously identical as being normally closed valve. In this arrangement, during all portions of the cleaning cycle except drying, the now normally closed valve 166 would be opened in response to the thermostat sensing a predetermined limit and the refrigerant would then flow into the evaporator coils 144 in the tank 20. As the refrigerant line to the evaporator coils 110 is also opened (because there is no valve) a portion of the refrigeration would also flow into it, however, because of the oversized capacity of the unit, sufficient refrigerant would flow to the coils 144 to cool the tank.
During the dry portion of the cycle, valve 166 would be prevented from being energized by the thermostat, and thus being a normally closed valve, would direct all the refrigerant into the coils 110 to condense the vapors in the circulating drying air. This last described system permits the elimination of one valve 164 from the previously described system.
Thus, the refrigeration system has a single compressor for alternatively primarily cooling two distinct evaporator coils under either a continuously timed demand for one coil or a cyclical temperature responsive demand for the other coil, with the time demand having precedent.
CONTROLS (FIG. 4)
As previously stated and as is well known in the art, the automatic dry cleaning machine is controlled for the most part through a timer mechanism 18 mounted in the back portion of the housing so as to be generally accessible to only certain personnel so that the cleaning cycle cannot normally be altered in any way.
However, in the present invention, provision is made for purposely altering the timer operation to provide what would normally be a dry portion of the cycle, but without rotating the tub or advancing the timer to other portions of the cycle. This modified dry operation is thus utilized to dry the filter cartridges, which must occasionally be replaced, prior to them being discarded to reclaim any residual solvent or solvent vapors therein that remain after the filters are removed from their housing 36 for replacement.
Normally, the proprietor would know when it was time to change the filters and would preferably allow the machine to remain quiescent for some period of time to permit solvent to gravitationally drain from the filters. However, as this does not remove all the recoverable solvent, the present machine permits the filters to be placed within the tub 4 and the control mechanism set to provide the above operation identified as "cartridge dry" on the timer control panel. To actuate the mechanism to this procedure, a switch (to be discussed) is included on the control panel having one switch arm serially connected in the timer motor circuit and another switch arm serially connected in the main motor circuit so that in the "cartridge dry" position of this switch, both motors are inactive. After placing the switch in this position, the timer is manually turned to any point in the dry portion of the cycle, thereby actuating all elements previously identified to accomplish a drying process within the machine. After some length of time sufficient to dry the cartridges, the cycle is manually terminated by turning the timer to an "off" position and returning the "cartridge dry" switch to the normal position, thereby readying the machine for further use by the customer.
Reference is now made to FIG. 4 to briefly describe the controls of the machine and particularly those appliciable to the "cartridge dry" operation. Thus, it is seen that the control circuit includes a door switch 160 which, and the position shown, represents the access door being closed, and which is necessary for the machine to operate. It is noted that in the door open position, switch 160 would simultaneously energize the exhaust valve 92 and exhaust door 120 for air flow through the access opening as previously explained.
A control box switch 162 is in series with one side of the door switch and, in the position shown, indicates the termination of the cleaning cycle and thus the stand-by position. As the access door is mechanically locked, whenever closed, it can only be unlocked for acces when this switch 162 is in the position shown by manually depressing a door unlock switch 164 which energizes an unlocking solenoid 168.
Once coins are deposited to initiate the cleaning cycle, the control box switch moves to its other position to energize the appropriate timer contacts and deactivate the line having the door unlock switch 164 so that the door can no longer be unlocked.
The timer 18 as well known, includes a plurality of cam actuated switches (only certain ones being illustrated) with the controlling cams rotatingly driven by a timer advancing motor 174. Also, as can be seen, the main motor 176 of the machine is controlled through a timer switch. The "cartridge dry" switch 172 is interposed in each motor line so that when moved to the "cartridge dry" position, contact 172A to the timer motor is opened along with contact 172B to the tumble winding of the main motor (the tumble winding being the winding that is energized through the timer when the timer is positioned in the dry portion of the cycle) thus preventing either advancement of the timer mechanism or rotation of the inner tub 4. When it has been determined that the cartridges are dry, the machine is returned to the normal operating condition by closing switch 172 and returning the timer to the initiation point of the dry cleaning cycle. | An ambient air intake system for a dry cleaner is disclosed which draws room air through the access opening when the door to the machine is open and vents this air to an outlet without passing it through the interior tubs which contain residual solvent vapor laden air. To accomplish this an air duct is interposed between the access opening of the cabinet housing the dry cleaner and the open end of the interior tubs, with the duct effectively sealed about the periphery of the cabinet opening and the open end of the outer tub and having aligned openings therethrough to define a passageway through which the clothes are inserted and removed. The duct is connected to an electrically actuated normally closed valve which in turn is connected to the inlet of a motor driven fan, the outlet side of which leads to an exhaust pipe. Both the valve and the fan are energized by a door switch when the door associated with the access opening is opened to draw ambient air into the accessed opening, then immediately into the air duct to be exhausted without passing into the interior of the tubs. This minimizes the commingling of the ambient air and the vapor laden air within the tubs to reduce the loss of solvent when the access door is opened. | big_patent |
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims priority from U.S. Provisional Patent Application Ser. No. 60/596311, filed Sep. 14, 2005 and entitled “Method and Apparatus For Forming A melt Spun Nonwoven Web”. The disclosure of this provisional patent application is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention pertains to methods and apparatus for spinning thermoplastic polymer filaments and, more particularly, to improvements therein using non-eductive drawing.
BACKGROUND
[0003] In general, spun bond nonwoven production machines can be classified as eductive “open” spinning systems and non-eductive “closed” spinning systems. Conventional broad loom eductive systems can generally trace their roots to the subject matter disclosed in U.S. Pat. No. 3,802,817 (Matsuki et al.) which describes a system that extrudes a curtain of filaments, extending the full width of the machine into, atmosphere (and/or impinged with cooled air). The curtain is then subjected to the action of a pair of air jet streams in a sucker, or filament drawing unit, the jet velocity of said jet streams being selected in the turbulent range. The jets act to entrain air from atmosphere along with the fibers which are then projected from the drawing unit onto a gas pervious conveyor belt collector to form a web. The quenching air system is separate from the filament drawing unit system. The fibers being spun are typically exposed to atmosphere at least once and usually twice: once just after being extruded and then again between the drawing device and the collector belt. This basic design has evolved into modern systems, for example, see U.S. Pat. Nos. 6,183,684 (Lu), 6,783,722 (Taylor) and 6,692,601 (Najour), all of which describe improved non-eductive “open” spinning nonwoven production systems.
[0004] Conventional broad loom non-eductive spinning systems can generally trace their roots to the disclosure in U.S. Pat. No. 4,405,297 (Appel et al.) which describes a system for forming spun bond nonwoven webs by spinning a plurality of filaments into a quench chamber where they are contacted with a quenching fluid, then utilizing the quench fluid to draw the filaments through a nozzle spanning the full machine width, and collecting the filaments as a web on a gas pervious conveyor belt collector. The fibers being spun are usually enclosed or shielded from atmosphere until they are formed into a web on a conveyor. This basic design has evolved into modern systems, for example U.S. Pat. No. 5,032,329 (Reifenhauser).
[0005] There are also hybrids of the two arts in which closed systems are aided by high pressure eductive jets to increase filament speeds, as shown in U.S. Pat. Nos. 5,503,784 (Balk) and 5,814,349 (Geus et al.).
[0006] The systems and methods discussed above have various disadvantages and limitations. Specifically, eductive (open) type systems inherently create high levels of turbulence and vorticity that are hard to control from day to day, and which tend to entangle and group the filaments into bundles, thereby limiting the uniformity of the final products. Furthermore, prior art eductive systems involve small fixed eductor throat openings which suffer drawbacks such as frequent plugging and cannot be opened to clear drips and plugs. In addition to plugging the throat of an eductor, small deposits of polymer drippings, monomer build up and scratches from constant cleaning all affect the patterns of turbulence on a day to day, and even on an hour to hour basis. The high speed jet nozzles themselves tend to become clogged by debris that enter from the process air supply and monomer, thereby drastically upsetting flow in the highest speed areas and creating vortices in the drawing unit. These systems also require two sources of air and two sets of associated equipment; one, a low pressure cooled air source that is used to quench the molten filaments by removing heat energy; and the other, a high pressure air source required to produce high velocity air to draw the filaments. The high velocity air generates high noise levels as it draws the filaments. While higher spin speeds required for spinning polyester and Nylon can be achieved with specialized eductive systems, the problems of turbulence and system hygiene are amplified by higher air jet pressures and velocities. Thus, forming a uniform web is very difficult with these systems because the fiber/air stream is moving very fast relative to the vertically stationary (but horizontally moving) collector belt. The amount of energy in the stream is so high at the belt that the fibers tend to bounce off the belt. The fibers can also be blown off the belt by the excess of air that cannot be passed through the below-the-belt vacuum system that generally is not able to evacuate all of the process air.
[0007] Conventional non-eductive (closed) systems typically permit somewhat more web formation control than do eductive systems; however, the non-eductive systems have fiber spin speed limitations. The long nozzle or throat sections where the fibers are attenuated are subjected to large structural loads from pressurized quench fluid. Even at pressures slightly above atmosphere, these walls must sustain loads of thousands of kilograms. These pressure loads cause deflection of the walls which, in turn, have to be pushed back into place uniformly across the machine width. The geometry of the nozzle controls quench fluid speed, which in turn controls fiber speed and formation of the web. Structural support of the wall geometry severely limits the pressure of the quench fluid, ergo the permissible velocity of the fluid in the nozzle and fiber speed. Also, the large surface areas of the nozzle have the same system hygiene problems as are present in eductive systems, but there is more surface area for deposits to collect, and it is not easy to get inside these nozzles to effect cleaning.
[0008] Hybrid systems were conceived primarily to increase the spin speeds of non-eductive systems. Hybrids typically incorporate eductive air jets somewhere along the nozzle area, which act to boost nozzle velocity without increasing quench fluid pressure. These systems have worked for some but not all higher speed spinning applications, and tend to be very complicated and capital intensive, and require substantial operation and maintenance attention.
SUMMARY OF THE INVENTION
[0009] In contrast to the prior art systems described above, the system and method of the present invention involve an initial quench chamber and the use of a continuous two-dimensional slot across the entire machine width which produces a linear plane of filaments in the slot impingement point section. The linear plane of filaments has substantially constant filament distribution across the machine width, and provides for good control of cross-machine uniformity. As used throughout this description, “machine widths” refers to a dimension corresponding to the width generally of the spinning plate and is perpendicular to the collector belt travel. It is preferred that the width correspond to the desired end web width. The width of the machine is only limited by the ability to machine and maintain close geometric tolerance of the impingement slot dimensions. The process equipment is very simple compared to both eductive and non-eductive systems.
[0010] No air is educted into this system as the quench fluid, usually air, undergoes uniform acceleration into the impingement slot where the drawing force is developed. The same air is used for two purposes: first to quench the filaments and then to draw them as the air exits through the drawing impingement slot at high velocity. The drawing chamber is relatively small and there is substantially no nozzle length parallel to the fiber/air stream; therefore higher quench pressures can be obtained without leading to structural deflection problems that affect spinning area geometric tolerances which in turn would cause variations in spin velocities and turbulence. Higher pressures and the mixing effect of the exiting fiber/quench stream produce very high air and fiber velocities. The small amount of close tolerance machined surface area that is exposed to the fiber stream (i.e., only the tips of the air knives) collect far less dirt, polymer drippings and monomer build up than other systems. Cleaning is much simpler and only takes a few seconds while the machine is running by opening the slot for a few seconds and wiping clean the knife edges. An automatic wiper could be employed. This can be done several times a day, if needed, whereas most other conventional systems require hours and even days to clean educator and nozzle surfaces.
[0011] By selecting a suitable slot gap opening, the necessary drawing tension can be obtained. Filament cooling is controlled by regulating the temperature of the quench fluid and controlling the rate of flow of air past the filaments to exhaust ports near the top of the quench chamber, as is known in the prior art. The amount of quench air exiting the duct is important to the operation of the process, so this flow rate is preferably closely monitored and controlled. If there is too high an exhaust flow, the velocity of the air through the filament bundle will cause the filaments to waver and stick to each other, thereby causing filament breakage. The filaments will also be cooled too rapidly and large denier, brittle filaments will be produced. With too little exhaust, the filaments may not be totally quenched when they enter the drawing impingement slot, increasing the incidence of sticking to the slot's air knives.
[0012] To achieve the benefits of the present invention, it is desirable that the apparatus be constructed and the method carried out within certain ranges of parameters. For example, the quench air should be maintained at a temperature in the range of from about 40° F. to 200° F. The air flow rate should be maintained within the range of from 850 cubic meters per hour to 3,400 cubic meters per hour per meter of machine width, and the slot opening should have a length from about 0.5 mm to 10 mm. As indicated above, the exhaust flow rate is important in achieving the desired filament properties and, generally, will be within the range of from nearly 0 to about 400 cubic meters per hour per meter of machine width.
[0013] The length of the quench chamber for a particular application will depend, of course, upon the material being spun and the particular web properties desired. Accordingly, these parameters may vary widely, but, in general, will be at least 250 mm and, preferably within the range of from about 250 mm to 1500 mm for the length of the quench zone from the spinneret to the impingement slot. Similarly, the spinneret capillaries may be in many configurations but will, generally, be employed in the range of from about 500 to 8000 holes per meter of machine width in a uniform capillary array. As will be apparent from the foregoing description, the method and apparatus of the present invention are extremely flexible and can be varied to accommodate a wide variety of materials and operating conditions. That constitutes a particular advantage and feature of the present invention.
[0014] The above and still further features and advantages of the present invention will become apparent upon consideration of the following definitions, descriptions and descriptive figures of specific embodiments thereof wherein like reference numerals in the various figures are utilized to designate like components. While these descriptions entail specific details of the invention, it should be understood that variations may and do exist and would be apparent to those skilled in the art based on the descriptions herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a schematic flow diagram of a preferred embodiment of the present invention shown operating in a “run” mode.
[0016] FIG. 2 is a schematic flow diagram of the preferred embodiment of FIG. 1 shown operating in a “run” mode.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] The following detailed explanations of FIGS. 1 and 2 of the preferred embodiments reveal the methods and apparatus of the present invention. The architecture depicted in the drawings is a conceptual diagram illustrating major functional units, and does not necessarily illustrate physical relationships.
[0018] The present invention harnesses the positive aspects of both eductive and non-eductive (and hybrid) systems into a more efficient and simpler design. More importantly, the invention solves many of the problems associated with conventional nonwoven spun bond systems including: spinning speed limitations, energy consumption, machine element cleanliness (i.e., hygiene), web uniformity, capital costs and process control. The invention also incorporates aspects of another, different type of nonwoven web forming technology, the meltblown process, as shown in U.S. Pat. No. 3,825,380 (Harding et al.) to help improve web formation control.
[0019] While the invention is described in connection with preferred embodiments, it will be understood that it is not intended to limit the invention to those embodiments. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.
[0020] Referring to FIG. 1 , the first step in the method of the invention is to provide a thermoplastic polymer in fluid condition for spinning. The flexibility of the system and method of the present invention allows a wide variety of polymers to be processed. For example, any of the following may be employed: polyamides, polyesters, polyolefins, polyvinyl acetate, polyvinyl chloride, polyvinyl alcohol, and the like. It is, of course, contemplated to also utilize other spinable materials which may not be ordinarily considered polymers such as, for example, molten glass and carbon fiber pre-cursors. It is important that the material be capable of being made sufficiently fluid for spinning and otherwise have the properties necessary to undergo drawing in the filament drawing zone. Other examples will become apparent to those skilled in the polymer art.
[0021] The molten polymer or other raw material is fed from supply 2 to hopper 4 , then through screw extruder 6 , filter 8 , and polymer transfer pipe 10 to spin box 12 , which contains one or more metering pumps 14 . Filaments 16 are spun through spinneret 18 with appropriate openings arranged in one or more rows forming a curtain of filaments 16 directed into the quench chamber 20 . In the quench chamber 20 the filaments 16 are contacted with air or other cooling fluid 22 received through fluid inlet 24 and diffused through perforated apertured plates 26 . The quench fluid, usually air, is maintained cooler than the filaments, preferably near ambient temperature, but anywhere, for example, in the range of from about 40° F. to 200° F. The quenching fluid is supplied under pressure of less than 4 bar, preferably less than 2 bar, and a portion is preferably directed through the filament curtain 16 and removed as exhaust through ports 28 .
[0022] As described above, the proportion of the air supplied that is discharged as exhaust will depend on the polymer being used and the rapidity of quenching needed to give desired filament characteristics such as denier, tenacity and the like, and to exhaust by-products of extrusion i.e.: smoke and monomer.
[0023] As quenching is completed, the filament curtain is directed through a narrowing lower end 30 of the quenching chamber into the impingement point slot opening 32 where the quench air attains a velocity that can be anywhere in the approximate range of 3,000 to 21,000 meters per minute. The drawing slot extends across the full machine width and is preferably formed by two identical air knives 34 having an angle in the range from about 15° degrees to 80°, with a preferred angle of 45°, spanning the width of the machine. In the preferred embodiment the bottom surfaces of the knives 34 are co-planar and substantially horizontal; however, it is to be understood that these surfaces can be angled to converge toward one another for certain applications. The convergence, if provided, would typically be such as to provide a protruding or convex bottom surface for the chamber, although in some instances a recessed or concave bottom surface may be provided. The movable air knives can be retracted from one another under the chamber assembly using a manually actuable and lockable slide arrangement, or a hydraulically or otherwise actuable arrangement. FIGS. 1 and 2 depict knives forming a 90° entry angle between them. The blades may either slide laterally or instead pivot about a point near the upper corner of the blade, whereby the tip of each blade would swing down in an arc until the upper blade surfaces came into a parallel relationship for cleaning. To pass slubs, the tips would only need to move ½″ or so apart.
[0024] Referring to FIG. 2 , during start-up, the knives are fully retracted or spaced from one another so that the filaments can fall by gravity through the wide open slot. The low velocity of the incoming quench air is maintained through the wide open slot so that little aerodynamic drawing actually occurs. When polymer flow is fully established, the air knives are slowly moved toward one another to decrease the slot opening, increase the air velocity, and draw the filaments. If a major process upset occurs and the drawing slot becomes partially plugged or clogged with polymer during operation, one or both air knives can be momentarily drawn back until the polymer plug falls through the enlarged nozzle opening. The air knives 34 can then be moved back to their normal operating position.
[0025] The position of the air knives relative to each other determines the size of the drawing nozzle opening and thus the velocity of the air going through the nozzle for a given quench air flow rate, pressure and exhaust setting. The filament drawing force increases as the air velocity increases so that the filament denier can be easily changed by simply increasing or decreasing the size of the nozzle opening. Filament denier can also be increased several other ways i.e.: enlarging the slot gap; reducing the air flow rate through the slot by decreasing the pressure in the chamber; increasing the exhaust air flow rate; lowering the quench air temperature; decreasing the polymer temperature; increasing the polymer viscosity; or increasing the polymer throughput per capillary.
[0026] Thus, the filament deniers can be changed relatively easily and rapidly in several different ways which do not affect the distribution of filaments exiting the slot to atmosphere. In all cases, the slot desirably spans the entire width of the machine. Therefore, a distribution of filaments corresponding substantially identically to the distribution of the orifices in the spin plate across the machine width is maintained all the way to the outlet of the slot. When the fibers and quench fluid exit the impingement slot 32 , they are exiting to atmosphere. Exposing the filaments to the interior of a high speed air stream, similar in speed to an eductive fiber draw unit jet stream, produces very good energy transfer from quench fluid velocity to fiber speed, for several reasons:
The air jet formed at the impingement point is transferring energy only to fibers (like a non eductive system) and not wasting energy entraining air from atmosphere to create the low pressure suction at the top of an eductive drawing device. The fibers are exposed to the air jet formed inside the impingement point, which means that the fibers see the peak velocity of the stream. In eductive systems, the fibers enter the stream (in the fiber draw unit) after the jet achieves peak velocity, after it mixes with atmosphere and entrained air, so that that the resultant energy transfer, directly to the fibers, is lower. When a stream of fluid is directed through an air knife slot to atmosphere, it immediately loses its pressure as it expands to atmosphere. Energy of the quench fluid mass is transformed from pressure to velocity. The stream begins to “opens up” or widen from the original slot width as the pressurized compressible gas expands, which, in turn, begins to slow the stream velocity. If one adds fibers at this point, the mix of expanding fluid and independent flexible fibers creates a highly turbulent mixing zone just below the exit which tremendously aids the transferring of quench fluid energy (mass×velocity) to fiber velocity. This also acts to slow down the stream. More specifically, within the first few inches after leaving the slot opening of the pressurized quench chamber, the stream of fibers and quench fluid is rapidly slowed as velocity energy of the quench fluid is transferred to the fibers and the fiber air stream entrains air from atmosphere, resulting in velocities of quench fluid and fibers that are much closer matched than conventional eduction open spinning systems. The fibers have a chance to slow down to a speed lower than their peak spinning speed which causes them to collapse on themselves and interweave and entangle before they reach the conveyor belt, resulting in improved web formation uniformity and isotropicity.
[0030] The distance from the spinneret to the impingement point is comparatively short; thus, the effects of friction between the spinning fibers' velocity and the quench fluid do not create much friction resistance on the fiber bundle compared to conventional systems with long quench and spin line distances. The higher density (compared to atmosphere) acts to remove heat energy faster, but can also lead to higher friction losses. Hence the spin line can be shorter than conventional systems
[0031] The dynamic nature of this fiber and quench fluid “stream” after it exits the slot impingement point is similar in nature to the fiber and air stream in meltblown processes. Therefore, those skilled in the art of forming meltblown nonwoven webs can control the laydown process in a similar manner. An additional advantage of this system is that the velocity energy of the system expands and dissipates very quickly, which means that the lay down speed of the fibers when they land on the conveyor collector are significantly slower than in conventional systems, which is much easier to control and leads to better web uniformity. As the fiber bundle slows down before hitting the belt, the fibers bunch up and fold over on each other, leading to better fiber distribution, which makes a more isotropic web in terms of strength and elongation and visual uniformity of basis weight distribution.
[0032] Referring again to FIG. 1 , a very important element of the invention involves the web forming table 40 positioned below the slot 32 of the quench chamber 20 to receive filaments 16 and form the filaments into a non-woven web. The web forming table 40 comprises a vacuum suction box 42 for pulling down filaments onto a moving mesh wire belt conveyor 44 which transports the as-formed web to the next stage of the process for strengthening the web by conventional techniques to produce the final non-woven fabric web. For example, one possible bonding method could be calendering, 50 . After bonding, the nonwoven fabric can be wound into rolls 60 for ease of shipping to final end user.
[0033] The specific test results listed in the Table below are illustrative of the operation of the present invention. The tests were carried out on apparatus of the type illustrated in FIGS. 1 and 2 having parameters indicated in the Table, a quench zone length of 24 inches from spinneret face to slot opening, slot gap openings as indicated in the Table, and a capillary throughput as indicated in the Table. The polymer spun was 35 MFI polypropylene with a melt temperature of about 235° C. The incoming angle of the combined air knives forming the slot opening was 90°, with an outgoing angle of 180°.
TABLE Quench Air slot Fume pack spin air Press. gap, Exh Low High Avg. Spin press, speed Run # temp F. psig gm/hole/min in. Diam. Denier Denier Denier Well? psi m/min 23 44 7.5 1 0.067 3/16″ 2.2 3.8 3.00 stable 1580 3,000 24 45 10 1 0.067 3/16″ 2.5 4.2 3.35 stable 1600 2,687 25 48 12 1 0.067 3/16″ 2.2 2.8 2.50 stable 1620 3,600 26 50 12 1.21 0.067 none 2.5 3.4 2.95 stable 1810 3,692 27 52 12.5 1.5 0.067 none 2.8 4.2 3.50 stable 2040 3,857 28 51 12.5 0.83 0.067 none 1.7 2.5 2.10 stable 1580 3,557 29 54 12.5 0.55 0.067 none 0.5 2.2 1.35 stable 1320 3,667 30 43 15 0.55 0.05 none 1.2 2.5 1.85 stable 1360 2,676 31 43 15 1 0.05 none 2.8 4.2 3.50 stable 1800 2,571 Conditions common to all runs: 35 MFI polypropylene polymer temperature 230° to 240° C. spinneret with 27 round spinning orifices in a 2″ diameter pattern spinning distance from spinneret face to slot knife edges = 24″ slot entrance vee = 90 degrees and exit flat
[0034] In summary, the foregoing specific examples illustrate the present invention and its operation highlighting spinning advantages. Preferred embodiments include the formation of low basis weight webs from fine polypropylene filaments of under 5 denier and production rates over 200 kg per hour per meter of beam width; point bonding these webs to produce a nonwoven material useful for many applications including (1) liners for sanitary products, (2) limited use garments, (3) surgical drapes and even (4) durable goods.
[0035] Another embodiment would include the formation of webs from fine or coarse filaments of polyester under 15 denier and production rates over 200 kg per hour per meter of beam width; point bonding or area bonding these webs to produce a nonwoven material useful for (1) industrial filtration, (2) automotive carpet, (3) roofing applications, (4) commercial dryer sheets (5) hygiene products.
[0036] The method and apparatus of the present invention are useful to make fine continuous filaments even if they are not formed into a spunbond web. For example, the spun fibers can be collected and used as pillow and cushion stuffing. For this purpose the fibers can be feed directly into the pillow or cushion casing from the slot opening of the quench chamber. Alternatively, the fibers can be baled and sold.
[0037] Thus it is apparent that there has been provided, in accordance with the invention, an improved method and apparatus for forming fine continuous filaments having particular utility in forming nonwoven webs in a manner that that fully satisfies the objects, aims, and advantages set forth above. While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications, and variations as fall within the spirit and broad scope of the appended claims.
[0038] Having described preferred embodiments of a new and improved method and apparatus for forming fine continuous filaments in general and melt spun nonwoven webs in particular, it is believed that other modifications, variations and changes will be suggested to those skilled in the art in view of the teachings set forth herein. It is therefore to be understood that all such variations, modifications and changes are believed to fall within the scope of the present invention as defined by the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation. | A method and apparatus for forming nonwoven melt spun webs by spinning a curtain of filaments into a pressurized chamber where they are contacted with pressurized quenching fluid, then using the fluid to draw the filaments through a slot at the bottom of the chamber. The slot is a narrow two dimensional impingement point running the length of the filament curtain where the pressurized quench fluid passes through, escaping to atmosphere. The fluid pressure (potential) energy in the chamber is exchanged for velocity (kinetic) energy at the slot impingement point. The fast moving stream of fluid inside and exiting the slot acts to pull, or draw the filaments through the slot. The fluid and fiber stream is deposited onto a porous collection conveyor belt, forming a fleece web. The invention is more efficient, less complicated, easier to maintain and easier to control than prior systems for melt spinning nonwoven webs. | big_patent |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to Japanese Patent Application No. 2012-055103 filed Mar. 12, 2012, the content of which is hereby incorporated herein by reference.
BACKGROUND
[0002] The present disclosure relates to a sewing machine, an embroidery unit, and a non-transitory computer-readable medium storing a sewing machine control program that allow sewing in a position specified on a work cloth.
[0003] A sewing machine is known that can easily set a sewing position and a sewing angle, at which a desired embroidery pattern is to be sewn, on a work cloth. For example, a known sewing machine includes an imaging portion. After a user affixes a marker to a specified position on the work cloth, an image of the marker may be captured by the imaging portion. The sewing machine may automatically set the sewing position and the sewing angle of the embroidery pattern based on the captured image of the marker.
SUMMARY
[0004] However, with the above-described sewing machine, it may be necessary to affix the marker to the work cloth. Further, after the sewing machine has set the sewing position and the sewing angle of the embroidery pattern, the user may need to remove the marker affixed to the work cloth before sewing is performed. Therefore, the operation may be troublesome for the user.
[0005] Embodiments of the broad principles derived herein provide a sewing machine, an embroidery unit, and a non-transitory computer-readable medium storing a sewing machine control program that enable easily setting a position, on a work cloth, at which sewing is performed.
[0006] Embodiments provide a sewing machine that includes at least one detecting portion, a processor, and a memory. The at least one detecting portion is configured to detect an ultrasonic wave that has been transmitted from a transmission source. The memory is configured to store computer-readable instructions that instruct the sewing machine to execute steps including identifying a position of the transmission source of the ultrasonic wave based on information pertaining to the ultrasonic wave that has been detected by the at least one detecting portion, and controlling sewing based on the position of the transmission source that has been identified.
[0007] Embodiments also provide an embroidery unit that can be attached to and detached from a bed of a sewing machine, and to which an embroidery frame can be attached, and that is configured to move the embroidery frame, the embroidery frame being configured to hold a work cloth. The embroidery unit includes at least one detecting portion and a notifying portion. The at least one detecting portion is configured to detect an ultrasonic wave that has been transmitted from a transmission source. The notifying portion is configured to notify the sewing machine of a detection timing at which the ultrasonic wave was detected by the at least one detecting portion. The embroidery unit is configured to move the work cloth based on a position of the transmission source of the ultrasonic wave that has been identified by the sewing machine based on the detection timing that has been notified by the notifying portion.
[0008] Embodiments further provide a non-transitory computer-readable medium storing a control program executable on a sewing machine. The program includes computer-readable instructions, when executed, to cause the sewing machine to perform the step of identifying, based on information pertaining to an ultrasonic wave that has been detected by at least one detecting portion of the sewing machine, a position of a transmission source of the ultrasonic wave. The at least one detecting portion is configured to detect the ultrasonic wave that has been transmitted from the transmission source. The program further includes computer-readable instructions, when executed, to cause the sewing machine to perform the step of controlling sewing based on the position of the transmission source that has been identified.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Embodiments will be described below in detail with reference to the accompanying drawings in which:
[0010] FIG. 1 is a front view of a sewing machine according to a first embodiment;
[0011] FIG. 2 is a perspective view of a receiver;
[0012] FIG. 3 is a front view of the receiver;
[0013] FIG. 4 is a cross-sectional view of the receiver taken along a line I-I shown in FIG. 3 , as seen in an arrow direction;
[0014] FIG. 5 is a block diagram showing an electrical configuration of the sewing machine and an ultrasonic pen according to the first embodiment;
[0015] FIG. 6 is a diagram illustrating a calculation method of specified coordinates E according to the first embodiment;
[0016] FIG. 7 is a flowchart showing main processing according to the first embodiment;
[0017] FIG. 8 is a front view of the sewing machine according to a second embodiment;
[0018] FIG. 9 is a plan view of an embroidery unit according to the second embodiment;
[0019] FIG. 10 is a right side view of the embroidery unit according to the second embodiment;
[0020] FIG. 11 is a front view of a sewing machine according to a third embodiment;
[0021] FIG. 12 is a block diagram showing an electrical configuration of the sewing machine and an ultrasonic pen according to the third embodiment;
[0022] FIG. 13 is a front view of a sewing machine according to a fourth embodiment;
[0023] FIG. 14 is a diagram illustrating a calculation method of specified coordinates E according to the fourth embodiment;
[0024] FIG. 15 is a flowchart showing main processing according to the fourth embodiment;
[0025] FIG. 16 is a front view of a sewing machine according to a fifth embodiment;
[0026] FIG. 17 is a right side view of a multi-needle sewing machine according to the fifth embodiment; and
[0027] FIG. 18 is a plan view of an embroidery frame movement mechanism according to the fifth embodiment.
DETAILED DESCRIPTION
First Embodiment
[0028] Hereinafter, a first embodiment will be explained with reference to the drawings. A configuration of a sewing machine 1 will be explained with reference to FIG. 1 . The near side, the far side, the upper side, the lower side, the left side, and the right side of FIG. 1 are respectively defined as the front side, the rear side, the upper side, the lower side, the left side, and the right side of the sewing machine 1 . Specifically, a direction in which a pillar 12 , which will be described below, extends is the up-down direction of the sewing machine 1 . The longitudinal direction of a bed 11 and an arm 13 is the left-right direction of the sewing machine 1 . A surface on which a plurality of operation switches 21 are arranged is a front face of the sewing machine 1 .
[0029] The sewing machine 1 includes the bed 11 , the pillar 12 , the arm 13 , and a head 14 . The bed 11 is a base portion of the sewing machine 1 and extends in the left-right direction. The pillar 12 extends upward from the right end of the bed 11 . The arm 13 extends to the left from the upper end of the pillar 12 such that the arm 13 faces the bed 11 . The head 14 is provided on the left end of the arm 13 . A needle plate 34 is disposed on a top surface of the bed 11 . A feed dog, a feed mechanism, a shuttle mechanism (which are not shown in the drawings) and a feed adjustment motor 83 (refer to FIG. 5 ) are provided below the needle plate 34 (namely, inside the bed 11 ). The feed dog may be driven by the feed mechanism, and may feed a work cloth 100 (refer to FIG. 6 ) by a specified feed distance. The feed adjustment motor 83 may adjust the feed distance of the feed dog.
[0030] A needle bar mechanism (not shown in the drawings), a needle bar swinging motor 80 (refer to FIG. 5 ) and the like are provided on the head 14 . The needle bar mechanism may drive a needle bar 29 in the up-down direction. A sewing needle (not shown in the drawings) may be attached to the needle bar 29 . The needle bar swinging motor 80 may swing the needle bar 29 in the left-right direction. A receiver 94 is provided at the lower left end of the head 14 , on the rear side of a lower surface of the head 14 . A receiver 95 is provided at the lower right end of the head 14 , on the rear side of the lower surface of the head 14 . The receivers 94 and 95 are separated from each other in the left-right direction by the length of the head 14 in the left-right direction. The receivers 94 and 95 are configured to receive (detect) an ultrasonic wave. The receivers 94 and 95 have the same configuration. The receivers 94 and 95 will be described in more detail later.
[0031] A cover 16 to be opened and closed is provided on an upper portion of the arm 13 . A thread spool (not shown in the drawings) may be accommodated underneath the cover 16 , that is, substantially in a central portion within the arm 13 . An upper thread (not shown in the drawings) may be wound around the thread spool. The upper thread may be supplied from the thread spool, through a thread hook (not shown in the drawings), to the sewing needle attached to the needle bar 29 . The thread hook is provided on the head 14 . The needle bar mechanism, which is provided inside the head 14 , may drive the needle bar 29 such that the needle bar 29 is moved up and down. The needle bar mechanism may be driven by a sewing machine motor 79 (refer to FIG. 5 ). A presser bar 31 extends downward from the lower end of the head 14 . A presser foot 30 may be detachably attached to the lower end of the presser bar 31 . The presser foot 30 may press down the work cloth 100 . The plurality of operation switches 21 are provided on a lower portion of the front face of the arm 13 . The plurality of operation switches 21 include a start/stop switch.
[0032] A liquid crystal display (LCD) 15 is provided on the front face of the pillar 12 . The LCD 15 may display images that include various types of items, such as a command, an illustration, a set value, a message, and the like. A touch panel 26 is provided on the front face of the LCD 15 . A user may perform an operation of pressing the touch panel 26 using a finger or a dedicated touch pen. Hereinafter, this operation is referred to as a “panel operation”. The touch panel 26 detects a position pressed by the finger, the dedicated touch pen, or the like, and the sewing machine 1 (more specifically, a CPU 61 that will be described below) determines the item that corresponds to the detected position. In this manner, the sewing machine 1 recognizes the selected item. By the panel operation, the user can select a pattern to be sewn and a command to be executed.
[0033] Connectors 39 and 40 are provided on a right surface of the pillar 12 . An external storage device (not shown in the drawings), such as a memory card, can be connected to the connector 39 . The sewing machine 1 may read out pattern data and various programs from the external storage device connected to the connector 39 . A connector 916 may be connected to the connector 40 . The connector 916 is coupled to a cable 912 that extends from an ultrasonic pen 91 (which will be described below). The sewing machine 1 may supply electric power to the ultrasonic pen 91 via the connector 40 , the connector 916 , and the cable 912 , and may acquire an electrical signal output from the ultrasonic pen 91 .
[0034] The ultrasonic pen 91 will be explained. The ultrasonic pen 91 includes a pen body 910 and a pen tip 911 . The pen body 910 has a bar shape. The pen tip 911 is provided at the leading end of the pen body 910 . A point of the pen tip 911 is sharp. Normally, the pen tip 911 is in a protruding position in which the pen tip 911 protrudes slightly to the outside from the pen body 910 . On the other hand, when a force toward the pen body 910 acts on the pen tip 911 , the pen tip 911 is inserted into the pen body 910 . When the force acting on the pen tip 911 is released, the pen tip 911 returns to the original protruding position.
[0035] The ultrasonic pen 91 includes a switch 913 (refer to FIG. 5 ), a signal output circuit 914 (refer to FIG. 5 ), and an ultrasonic transmitter 915 (refer to FIG. 5 ) inside the pen body 910 . The switch 913 is turned on and off in accordance with the position of the pen tip 911 . The switch 913 may switch output states of the signal output circuit 914 and the ultrasonic transmitter 915 .
[0036] When no force acts on the pen tip 911 (when the pen tip 911 is in the protruding position), the switch 913 is in an OFF state. When the switch 913 is in the OFF state, the signal output circuit 914 does not output an electrical signal and the ultrasonic transmitter 915 does not output an ultrasonic wave. On the other hand, when the user presses the pen tip 911 against an arbitrary position on the work cloth 100 , a force acts on the pen tip 911 . At this time, the pen tip 911 is inserted into the pen body 910 and the switch 913 is turned on. When the switch 913 is turned on, the signal output circuit 914 outputs an electrical signal to the sewing machine 1 via the cable 912 , and the ultrasonic transmitter 915 transmits an ultrasonic wave.
[0037] As will be described in detail below, the sewing machine 1 can receive (detect) the ultrasonic wave transmitted from the ultrasonic pen 91 using the receivers 94 and 95 . Based on the detected ultrasonic wave, the sewing machine 1 can identify a transmission source of the ultrasonic wave, namely, the position of the ultrasonic transmitter 915 provided in the ultrasonic pen 91 . The sewing machine 1 can perform sewing based on the identified position. Thus, the user can specify an arbitrary position on the work cloth 100 by pressing the pen tip 911 of the ultrasonic pen 91 on the work cloth 100 (touching the work cloth 100 with the pen tip 911 ). As a result, it is possible to perform sewing in the specified position.
[0038] The receiver 94 will be explained with reference to FIG. 2 to FIG. 4 . The receiver 95 has the same configuration as that of the receiver 94 , so an explanation thereof is omitted. The lower left side, the upper right side, the upper left side, the lower right side, the upper side, and the lower side of FIG. 2 are respectively defined as the front side, the rear side, the left side, the right side, the upper side, and the lower side of the receiver 94 .
[0039] As shown in FIG. 2 and FIG. 3 , the receiver 94 has a rectangular parallelepiped shape that is slightly longer in the up-down direction. An opening 941 is provided in the center of a lower end portion of the front face of the receiver 94 . The opening 941 has an elliptical shape that is long in the left-right direction. A wall 942 around the opening 941 is a tapered surface (an inclined surface) that becomes narrower from the outer side toward the inner side of a front surface of the receiver 94 . As shown in FIG. 4 , a substrate 943 and a microphone 944 are provided inside the receiver 94 . The microphone 944 is provided, inside the receiver 94 , behind the opening 941 . A connector 945 is mounted on an upper end of a rear surface of the substrate 943 . The connector 945 may be connected to a connector (not shown in the drawings) that is provided on the sewing machine 1 . An orientation of the receiver 94 is determined by a direction of the opening 941 in relation to the microphone 944 .
[0040] An electrical configuration of the sewing machine 1 and the ultrasonic pen 91 will be explained with reference to FIG. 5 . A control portion 60 of the sewing machine 1 includes a CPU 61 , a ROM 62 , a RAM 63 , an EEPROM 64 , and an input/output interface 65 , which are mutually connected via a bus 67 . The ROM 62 stores programs and data etc. that are used by the CPU 61 to execute processing. The EEPROM 64 stores data of various types of sewing patterns that are used for the sewing machine 1 to perform sewing.
[0041] The operation switches 21 , the touch panel 26 , and drive circuits 71 , 72 , 74 , 75 , and 76 are electrically connected to the input/output interface 65 . The drive circuits 71 , 72 , 74 , 75 , and 76 may respectively drive the feed adjustment motor 83 , the sewing machine motor 79 , the needle bar swinging motor 80 , the LCD 15 , the receiver 94 , and the receiver 95 . The drive circuit 76 includes an amplification circuit. The amplification circuit may amplify ultrasonic signals detected by the receivers 94 and 95 , and may transmit the amplified signals to the CPU 61 .
[0042] The electrical configuration of the ultrasonic pen 91 will be explained. The ultrasonic pen 91 includes the switch 913 , the signal output circuit 914 , and the ultrasonic transmitter 915 . The switch 913 is connected to the signal output circuit 914 and the ultrasonic transmitter 915 . The signal output circuit 914 can be connected to the input/output interface 65 . The signal output circuit 914 may output an electrical signal to the CPU 61 via the input/output interface 65 .
[0043] A method of identifying a position on the work cloth 100 specified using the ultrasonic pen 91 will be explained with reference to FIG. 6 . The user may cause the pen tip 911 of the ultrasonic pen 91 to touch the work cloth 100 , and thereby may specify a position on the work cloth 100 where sewing is to be performed by the sewing machine 1 . Hereinafter, a position on the work cloth 100 that is touched by the pen tip 911 of the ultrasonic pen 91 is also referred to as a specified position. As described below, the sewing machine 1 may identify a specified position by identifying a position of a transmission source of an ultrasonic wave. Therefore, strictly speaking, the position of the ultrasonic transmitter 915 provided in the ultrasonic pen 91 is identified, rather than the position on the work cloth 100 touched by the pen tip 911 . The pen tip 911 and the ultrasonic transmitter 915 are arranged very close to each other. Therefore, the position of the ultrasonic transmitter 915 may be assumed as the position on the work cloth 100 touched by the pen tip 911 , namely, the specified position. Hereinafter, the left-right direction, the front-rear direction, and the up-down direction of the sewing machine 1 are respectively defined as an X direction, a Y direction, and a Z direction. The left-right direction and the up-down direction of FIG. 6 respectively correspond to the X direction and the Y direction. A direction from the near side to the far side corresponds to the Z direction.
[0044] The sewing machine 1 identifies the specified position as coordinate information (an X coordinate, a Y coordinate, and a Z coordinate). Here, the coordinate origin (0, 0, 0) is defined as a center point of a needle hole. The needle hole is formed in the needle plate 34 (refer to FIG. 1 ), and is a hole through which the sewing needle may pass. The center point of the needle hole is a needle drop point, which will be described below. The Z coordinate of a top surface of the needle plate 34 is 0. Coordinates B that indicate the position of the receiver 94 are denoted by (Xb, Yb, Zb). Coordinates C that indicate the position of the receiver 95 are denoted by (Xc, Ye, Zc). Coordinates E that indicate the specified position are denoted by (Xe, Ye, Ze), The Z coordinate of the receivers 94 and 95 indicates the height of the receivers 94 and 95 with respect to the top surface of the needle plate 34 . The coordinates B (Xb, Yb, Zb) and the coordinates C (Xc, Ye, Zc) are stored in advance in the ROM 62 . Hereinafter, the coordinates E are also referred to as “specified coordinates E”. A distance between the specified coordinates E and the coordinates B is referred to as a “distance EB”. A distance between the specified coordinates E and the coordinates C is referred to as a “distance EC”.
[0045] The distances EB and EC can be expressed by the coordinates B, C, and E based on the Pythagorean theorem. The distance EB and the coordinates B, C, and E satisfy a relationship of Formula (1) below. In a similar manner, the distance EC and the coordinates B, C, and E satisfy a relationship of Formula (2) below.
[0000] ( Xb−Xe ) 2 +( Yb−Ye ) 2 +( Zb−Ze ) 2 =( EB ) 2 Formula (1)
[0000] ( Xc−Xe ) 2 +( Yc−Ye ) 2 +( Zc−Ze ) 2 =( EC ) 2 Formula (2)
[0046] Formula (1) is the same as the equation of a spherical surface (whose radius is the distance EB), the origin of which is the coordinates B and on which the specified coordinates E is. In a similar manner, Formula (2) is the same as the equation of a spherical surface (whose radius is the distance EC), the origin of which is the coordinates C and on which the coordinates E is.
[0047] The speed at which an ultrasonic wave travels is assumed to be a sonic velocity V. A time required from when the ultrasonic wave is transmitted from the ultrasonic pen 91 at the specified coordinates E to when the ultrasonic wave reaches the receiver 94 is referred to as a propagation time Tb. A time required from when the ultrasonic wave is transmitted from the ultrasonic pen 91 at the specified coordinates E to when the ultrasonic wave reaches the receiver 95 is referred to as a propagation time Tc. In this case, the distances EB and EC are expressed by the following Formulas (3) and (4).
[0000] EB=V×Tb Formula (3)
[0000] EC=V×Tc Formula (4)
[0048] The following Formulas (5) and (6) are obtained by substituting Formulas (3) and (4) into Formulas (1) and (2) described above.
[0000] ( Xb−Xe ) 2 +( Yb−Ye ) 2 +( Zb−Ze ) 2 =( V×Tb ) 2 Formula (5)
[0000] ( Xc−Xe ) 2 +( Ye−Ye ) 2 +( Zc−Ze ) 2 =( V×Tc ) 2 Formula (6)
[0049] In Formulas (5) and (6), the coordinates B (Xb, Yb, Zb), the coordinates C (Xc, Ye, a) and the sonic velocity V are known values and stored in advance in the ROM 62 . The propagation time Tb and the propagation time Tc are each identified by calculating a difference between a transmission timing T 1 and a detection timing T 2 . The transmission timing T 1 is a timing at which the ultrasonic wave is transmitted from the ultrasonic transmitter 915 of the ultrasonic pen 91 . The detection timing T 2 is a timing at which the ultrasonic wave is detected by each of the receivers 94 and 95 . The thickness of the work cloth 100 is small enough to be ignored, in comparison to the values Xe and Ye. Therefore, the value Ze of the specified coordinates E (Xe, Ye, Ze) can be deemed to be zero. Thus, the values Xe and Ye can be calculated by solving the simultaneous equations represented by Formulas (5) and (6). Here, taking orientations of the receivers 94 and 95 into account, the specified coordinates E (Xe, Ye, Ze (=0)) on the work cloth 100 that are specified using the ultrasonic pen 91 can be determined.
[0050] It is preferable that the receivers 94 and 95 be provided in positions of the sewing machine 1 that satisfy the following conditions (A) to (E). In an explanation of the conditions (A) to (E), the receivers 94 and 95 are referred to as receivers 93 for convenience of the explanation.
[0051] (A) An object is unlikely to enter between the ultrasonic pen 91 and the receivers 93 .
[0052] (B) The receivers 93 are separated from each other to some extent.
[0053] (C) The distance, in the X direction and the Y direction, from the needle hole (the origin) of the needle plate 34 to the receivers 93 is large.
[0054] (D) The distance from the needle hole (the origin) to the receivers 93 is not extremely large.
[0055] (E) The receivers 93 are provided above the top surface of the bed 11 . Specifically, the receivers 94 are provided above the work cloth 100 placed on the bed 11 .
[0056] The reasons are as follows.
[0057] The condition (A) is set because if an object enters between the ultrasonic pen 91 and the receivers 93 , the receivers 93 may not receive the ultrasonic wave transmitted from the ultrasonic pen 91 . The object may be, for example, a hand or an arm of the user. For example, there is a possibility that the hand or the arm enters between the pen tip 911 and the receivers 93 when the user who holds the ultrasonic pen 91 in the user's hand is specifying the specified position. In this case, the ultrasonic wave transmitted from the ultrasonic pen 91 may be shielded by the hand or the arm. Therefore, a case may occur in which the receivers 93 cannot receive the ultrasonic wave. For that reason, it is preferable that the receivers 93 be provided in positions where the hand or the arm of the user does not enter between the ultrasonic pen 91 and the receivers 93 when the user is performing an operation using the ultrasonic pen 91 .
[0058] The reason for setting the condition (B) is as follows. When the simultaneous equations represented by Formulas (5) and (6) are solved, if the difference between the coordinates B and C is small, the results of Formulas (5) and (6) are close to each other. In this case, an error of the calculated specified coordinates E may become large.
[0059] The reason for setting the condition (C) is as follows. As the distance from the origin to the receivers 93 in the X direction and the Y direction increases, the Z-coordinate values of the coordinates B and C become relatively smaller than the X-coordinate values and the Y-coordinate values of the coordinates B and C. Therefore, it is possible to reduce an influence on a calculation result caused by the thickness of the work cloth 100 .
[0060] The reason for setting the condition (D) is as follows. If the distance from the origin to the receivers 93 is extremely large, the ultrasonic wave transmitted from the ultrasonic pen 91 may be attenuated before the ultrasonic wave reaches the receivers 93 . Therefore, it is difficult for the receivers 93 to accurately receive the ultrasonic wave.
[0061] The reason for setting the condition (E) is that the pen tip 911 of the ultrasonic pen 91 may come into contact with the top surface of the work cloth 100 that is placed on the bed 11 . It is preferable that the receivers 93 can accurately receive the ultrasonic wave transmitted from the ultrasonic pen 91 that is in contact with the top surface of the work cloth 100 , Therefore, it is preferable that the receivers 93 be provided above the top surface of the bed 11 .
[0062] In the first embodiment, as shown in FIG. 1 , the receiver 94 is provided at the lower left end of the head 14 and the receiver 95 is provided at the lower right end of the head 14 . The position on the work cloth 100 that can be easily specified by the user while the user is holding the ultrasonic pen 91 in the user's hand may be a position on the front side with respect to the needle hole. Thus, the condition (A) is substantially satisfied. The distance between the receivers 94 and 95 is almost the same as the length of the head 14 in the left-right direction. Therefore, the receivers 94 and 95 are sufficiently separated from each other, and the condition (B) is satisfied. The receivers 94 and 95 are provided on the rear side of the lower surface of the head 14 . Thus, the distances from the origin to the receivers 94 and 95 in the X direction and the Y direction are larger than when the receivers 94 and 95 are provided substantially in the center, in the front-rear direction, of the lower surface of the head 14 . Thus, the condition (C) is satisfied. The distances from the origin to the receivers 94 and 95 are not extremely large. Thus, the condition (D) is satisfied. The receivers 94 and 95 are provided above the top surface of the bed 11 . Thus, the condition (E) is satisfied. In this manner, in the first embodiment, the positions in which the receivers 94 and 95 are provided satisfy all the conditions (A) to (E). Therefore, the sewing machine 1 can calculate the specified coordinates E more precisely.
[0063] Processing that is performed by the CPU 61 of the sewing machine 1 to identify the specified position will be specifically explained with reference to FIG. 7 . Main processing is performed by the CPU 61 in accordance with the program stored in the ROM 62 . For example, when a command to perform sewing is input by a panel operation, the CPU 61 may start the main processing.
[0064] The CPU 61 determines whether an electrical signal output from the signal output circuit 914 of the ultrasonic pen 91 has been detected via the cable 912 (step S 11 ). If the electrical signal has not been detected (NO at step S 11 ), the processing returns to step S 11 . It is assumed that the user specifies an arbitrary position on the work cloth 100 using the ultrasonic pen 91 and the pen tip 911 of the ultrasonic pen 91 comes into contact with the work cloth 100 . The pen tip 911 of the ultrasonic pen 91 may be inserted into the pen body 910 and the switch 913 may be turned on. The signal output circuit 914 may output an electrical signal. The CPU 61 may detect the electrical signal (YES at step S 11 ). In a case where the switch 913 of the ultrasonic pen 91 is turned on, the ultrasonic transmitter 915 transmits an ultrasonic wave at the same time as when the signal output circuit 914 outputs the electrical signal. However, the propagation speed of the electrical signal is significantly higher than the propagation speed of the ultrasonic wave, and the electrical signal reaches the CPU 61 substantially at the same timing as the timing at which the switch 913 is turned on.
[0065] If the CPU 61 has detected the electrical signal output from the signal output circuit 914 of the ultrasonic pen 91 (YES at step S 11 ), the CPU 61 identifies a time at which the electrical signal is detected. The CPU 61 acquires the identified time as the transmission timing T 1 of the ultrasonic wave (step S 13 ). The CPU 61 stores the acquired transmission timing T 1 in the RAM 63 .
[0066] The CPU 61 determines whether the ultrasonic wave transmitted from the ultrasonic pen 91 has been detected via at least one of the receivers 94 and 95 (step S 15 ). If the ultrasonic wave has not been detected via at least one of the receivers 94 and 95 (NO at step S 15 ), the CPU 61 determines whether or not a predetermined time period (for example, one second) has elapsed (step S 35 ). If the predetermined time period has not elapsed (NO at step S 35 ), the processing returns to step S 15 . The CPU 61 stands by for the predetermined time period until at least one of the receivers 94 and 95 detect the ultrasonic wave.
[0067] Here, it is assumed that the ultrasonic wave transmitted from the ultrasonic transmitter 915 of the ultrasonic pen 91 is shielded by, for example, the hand or the arm of the user, the work cloth 100 , or the like and does not reach the receivers 94 and 95 . In this manner, if the predetermined time period has elapsed without detecting the ultrasonic wave by at least one of the receivers 94 and 95 (YES at step S 35 ), the CPU 61 displays on the LCD 15 an error message indicating that the ultrasonic wave has not been detected (step S 37 ). In a case where the user sees the error message, the user may once again specify an arbitrary position on the work cloth 100 using the ultrasonic pen 91 . The processing returns to step S 11 to re-detect the electrical signal output from the signal output circuit 914 of the ultrasonic pen 91 .
[0068] If the CPU 61 detects the ultrasonic wave via at least one of the receivers 94 and 95 within the predetermined time period from the detection of the electrical signal (YES at step S 15 ), the CPU 61 identifies a time at which the ultrasonic wave is detected. The CPU 61 acquires the identified time as the detection timing T 2 (step S 17 ). The CPU 61 stores the acquired detection timing T 2 in the RAM 63 .
[0069] The CPU 61 determines whether both the receivers 94 and 95 have detected the ultrasonic wave (step S 19 ). If one of the receivers 94 and 95 has not detected the ultrasonic wave (NO at step S 19 ), the processing returns to step S 15 . If both the receivers 94 and 95 have detected the ultrasonic wave (YES at step S 19 ), the CPU 61 calculates the propagation time Tb and the propagation time Tc (step S 21 ). The CPU 61 calculates the propagation time Tb and the propagation time Tc by subtracting the transmission timing T 1 from the detection timing T 2 .
[0070] The CPU 61 multiplies the calculated Tb and Tc by the sonic velocity V and thereby calculates the distances EB and EC (step S 23 ) (refer to Formulas (3) and (4)). The CPU 61 substitutes the coordinates B (Xb, Yb, Zb), the coordinates C (Xc, Ye, Ze), and the distances EB and EC into Formulas (5) and (6), and solves the simultaneous equations. Thus, the CPU 61 calculates the specified coordinates E (Xe, Ye, Ze (=0)). In this manner, the CPU 61 identifies the position specified using the ultrasonic pen 91 , namely, the specified position (step S 25 ).
[0071] The CPU 61 displays, on the LCD 15 , a display image that shows a relationship between the specified position, which is indicated by the specified coordinates E (Xe, Ye, Ze), and the work cloth 100 (step S 27 ). The CPU 61 determines whether the start/stop switch, which is one of the operation switches 21 , has been pressed (step S 29 ). If the start/stop switch has not been pressed (NO at step S 29 ), the processing returns to step S 29 . If the start/stop switch has been pressed (YES at step S 29 ), the CPU 61 drives the feed dog and moves the work cloth such that the position indicated by the X-coordinate “Xe” and the Y-coordinate “Ye” of the specified coordinates E calculated at step S 25 matches the needle drop point (step S 31 ). Then, the CPU 61 starts sewing (step S 33 ). In this manner, sewing is started from the position on the work cloth 100 specified using the ultrasonic pen 91 , namely, the specified position. When the sewing is complete, the main processing ends. The needle drop point is a point at which the sewing needle may penetrate the work cloth 100 , namely, the center point of the needle hole formed in the needle plate 34 .
[0072] As explained above, in a case where the user specifies an arbitrary position on the work cloth 100 using the ultrasonic pen 91 , the sewing machine 1 can identify the specified position and start sewing. In this manner, the user can easily and appropriately specify a position on the work cloth 100 using the ultrasonic pen 91 . The sewing machine 1 can detect the ultrasonic wave using the plurality of receivers 94 and 95 , and calculate the specified coordinates E based on the transmission timing T 1 and the detection timings T 2 . Thus, the sewing machine 1 can accurately identify the specified position.
[0073] The present disclosure is not limited to the first embodiment and various modifications may be made. The positions in which the receivers 94 and 95 are provided are not limited to the head 14 of the sewing machine 1 . For example, the receivers 94 and 95 may be provided on at least one of the presser foot 30 and the presser bar 31 . More specifically, the receiver 94 may be provided on the left side of the presser foot 30 or the presser bar 31 and the receiver 95 may be provided on the right side of the presser foot 30 or the presser bar 31 .
[0074] For example, the receiver 94 may be provided on one of the head 14 , the presser foot 30 , and the presser bar 31 , and the receiver 95 may be provided on the arm portion 13 side of the pillar 12 , namely, on any part of a left surface 17 (refer to FIG. 1 ) of the pillar 12 . In this case, the opening 941 of the receiver 95 is provided such that the opening 941 faces to the left. In this case, the distance between the receivers 94 and 95 is larger than when the receiver 95 is provided on the head 14 (refer to condition (B)). The distance, in the X direction and the Y direction, from the needle hole (the origin) of the needle plate 34 to the receiver 95 also increases (refer to condition (C)). Further, the receivers 94 and 95 are provided above the top surface of the bed 11 (refer to condition (E)). In this manner, the positions in which the receivers 94 and 95 are provided satisfy a plurality of conditions included in the conditions (A) to (E), in a similar manner to the first embodiment. Therefore, the sewing machine 1 can precisely calculate the specified coordinates E. Further, particularly in this case, it is possible to increase the distance between the receivers 94 and 95 .
[0075] The combinations of the positions of the receivers 94 and 95 are not limited to those of the first embodiment and the modified examples described above. In a case where the receivers 94 and 95 are provided on the head 14 , the positions of the receivers 94 and 95 are not limited to the rear side of the lower surface of the head 14 . For example, the receivers 94 and 95 may be provided on the front side of the lower surface of the head 14 , substantially in the center in the front-rear direction of the lower surface of the head 14 , or the like. In a case where the receiver 95 is provided on the left surface 17 of the pillar 12 , the height at which the receiver 95 is disposed is not particularly limited. However, it is preferable that the receiver 95 be disposed in a lower position in order to reduce an influence caused by approximating the value Ze in Formulas (5) and (6) to zero.
[0076] The receivers 94 and 95 may be provided on a part other than the head 14 , the presser foot 30 , the presser bar 31 , and the left surface 17 of the pillar 12 . For example, the receivers 94 and 95 may be provided on a lower side surface of the arm 13 , a front surface or a rear surface of the head 14 , or an upper surface of the bed 11 at the left end of the bed 11 . The ultrasonic pen 91 need not necessarily be attached to the sewing machine 1 . The sewing machine 1 may detect an ultrasonic wave output from a known device configured to output an ultrasonic wave, and may identify a position of the transmission source of the ultrasonic wave as the specified position.
Second Embodiment
[0077] A second embodiment will be explained. In the second embodiment, as shown in FIG. 8 to FIG. 10 , receivers 84 and 85 are provided not on the sewing machine 1 , but on an embroidery unit 2 , which can be attached to and detached from the bed 11 of the sewing machine 1 . FIG. 9 and FIG. 10 show the embroidery unit 2 that is not attached to the sewing machine 1 . The embroidery unit 2 includes a body portion 51 and a carriage 52 .
[0078] As shown in FIG. 9 and FIG. 10 , a connection portion 54 is provided on a right surface of the body portion 51 of the embroidery unit 2 . In a state in which the embroidery unit 2 is attached to the sewing machine 1 , the connection portion 54 is connected to a connection receiving portion (not shown in the drawings) of the sewing machine 1 , and thus the embroidery unit 2 and the sewing machine 1 are electrically connected.
[0079] The carriage 52 is provided on the upper side of the body portion 51 . The carriage 52 has a rectangular parallelepiped shape that is long in the front-rear direction. The carriage 52 includes a frame holder 55 , a Y axis movement mechanism (not shown in the drawings), and a Y axis motor (not shown in the drawings). The frame holder 55 is a holder to which an embroidery frame (not shown in the drawings) can be detachably attached. The holder 55 is provided on a right surface of the carriage 52 . The embroidery frame is a known frame that includes an inner frame and an outer frame. The embroidery frame may clamp and hold the work cloth 100 . The work cloth 100 held by the embroidery frame may be arranged on the top surface of the bed 11 and below the needle bar 29 and the presser foot 30 . The Y axis movement mechanism may move the frame holder 55 in the front-rear direction (the Y direction). Along with the movement of the frame holder 55 in the front-rear direction, the work cloth 100 held by the embroidery frame may be moved in the front-rear direction. The Y axis motor may drive the Y axis movement mechanism. The CPU 61 (refer to FIG. 5 ) controls the Y axis motor.
[0080] An X axis movement mechanism (not shown in the drawings) and an X axis motor (not shown in the drawings) are provided inside the body portion 51 . The X axis movement mechanism may move the carriage 52 in the left-right direction (the X direction). Along with the movement of the carriage 52 in the left-right direction, the work cloth 100 held by the embroidery frame may be moved in the left-right direction. The X axis motor may drive the X axis movement mechanism. The CPU 61 controls the X axis motor.
[0081] The receiver 84 is provided at the front end of an upper surface of the carriage 52 . The receiver 85 is provided at the rear end of the upper surface of the carriage 52 . The receivers 84 and 85 receive are configured to an ultrasonic wave. The receivers 84 and 85 have the same configuration as the receivers 94 and 95 . The embroidery frame attached to the frame holder 55 is located at the right of the right surface of the carriage 52 , Therefore, the receivers 84 and 85 are located above the position of the carriage 52 where the embroidery frame can be attached. Thus, the receivers 84 and 85 are located above the body portion 51 of the embroidery unit 2 . When the embroidery unit 2 is attached to the bed 11 of the sewing machine 1 , the receivers 84 and 85 are located above the bed 11 . Openings of the receivers 84 and 85 are directed to the right. In a case where the receivers 84 and 85 receive an ultrasonic wave, the receivers 84 and 85 each transmit an electrical signal to the sewing machine 1 . The CPU 61 may receive the electrical signals from the receivers 84 and 85 , and thereby may detect the ultrasonic wave transmitted from the ultrasonic pen 91 .
[0082] Processing that is performed by the CPU 61 of the sewing machine 1 to identify the specified position will be explained with reference to FIG. 7 . In a case where the CPU 61 detects an electrical signal output from the signal output circuit 914 of the ultrasonic pen 91 via the cable 912 (YES at step S 11 ), the CPU 61 acquires the transmission timing T 1 (step S 13 ). In a case where the CPU 61 receives the electrical signal from each of the receivers 84 and 85 (YES at step S 15 ), the CPU 61 identifies a time at which the electrical signal is received from the receiver 84 and a time at which the electrical signal is received from the receiver 85 , and acquires the identified times as the detection timings T 2 (step S 17 ). The CPU 61 calculates the specified coordinates E and identifies the specified position (steps S 21 to S 25 ). The CPU 61 controls the X axis motor and the Y axis motor, and thereby moves the embroidery frame such that the position of the specified coordinates E on the work cloth 100 matches the needle drop point (step S 31 ). Next, the CPU 61 starts sewing on the work cloth 100 . The CPU 61 drives the needle bar 29 and the shuttle mechanism (not shown in the drawings) simultaneously with the embroidery frame being moved in the left-right direction (the X direction) and the front-rear direction (the Y direction). The sewing needle attached on the needle bar 29 sews an embroidery pattern on the work cloth 100 held by the embroidery frame. In this manner, the embroidery pattern is sewn in the specified position on the work cloth 100 (step S 33 ).
[0083] In the second embodiment, the receivers 84 and 85 are respectively provided at the front end and the rear end of the carriage 52 , as shown in FIG. 9 and FIG. 10 . Therefore, when the embroidery unit 2 is attached to the bed 11 , all the above-described conditions (A) to (E) are satisfied. The ultrasonic wave transmitted from the ultrasonic pen 91 when the pen tip 911 is in contact with the work cloth 100 may be not shielded by the hand or the arm of the user (refer to condition (A)). The distance between the receivers 84 and 85 is separated by a length, in the front-rear direction, of the carriage 52 . As a result, the receivers 84 and 85 are sufficiently separated from each other (refer to condition (B)). The distances, in the X direction and the Y direction, from the needle hole (the origin) of the needle plate 34 to the receivers 84 and 85 are larger than when the receivers 84 and 85 are provided on the head 14 , the presser foot 30 or the presser bar 31 of the sewing machine 1 (refer to condition (C)). The distances from the origin to the receivers 84 and 85 are not extremely large (refer to condition (D)). The receivers 84 and 85 are provided above the body portion 51 of the embroidery unit 2 . Therefore, the receivers 84 and 85 are located above the bed 11 (refer to condition (E)). Specifically, the receivers 84 and 85 are provided above the work cloth 100 held by the embroidery frame. Therefore, the sewing machine 1 can calculate the specified coordinates E more precisely and perform sewing on the work cloth 100 . Further, the height from the top surface of the bed 11 to the receivers 84 and 85 is low. If the height from the top surface of the bed 11 to the receivers 84 and 85 is high, there is a possibility that the influence on a calculation result caused by the thickness of the work cloth 100 increases. If the height from the top surface of the bed 11 to the receivers 84 and 85 is low, the influence caused by approximating the value Ze in Formulas (5) and (6) to zero may decrease. Therefore, the error of the calculated specified coordinates E may become small.
[0084] In the second embodiment, the receivers 84 and 85 may be provided on a part other than the top surface of the carriage 52 . For example, the receiver 84 may be provided on a front surface of the carriage 52 and the receiver 85 may be provided on a rear surface of the carriage 52 . For example, the receiver 84 may be provided at the front side of the right surface of the carriage 52 , and the receiver 85 may be provided at the rear side of the right surface of the carriage 52 .
Third Embodiment
[0085] A third embodiment will be explained. As shown in FIG. 11 , the sewing machine 1 of the third embodiment is different from the sewing machine 1 of the first embodiment in that the sewing machine 1 is provided with an ultrasonic pen 92 that is not connected to the sewing machine 1 via a cable. Instead of the signal output circuit 914 (refer to FIG. 5 ), an electromagnetic wave output circuit 921 (refer to FIG. 12 ) is provided inside the ultrasonic pen 92 . The ultrasonic pen 92 accommodates a battery (not shown in the drawings). The ultrasonic pen 92 may be driven by the battery. The electromagnetic wave output circuit 921 may output an electromagnetic wave signal of a predetermined frequency. When the switch 913 (refer to FIG. 12 ) is in an OFF state, the electromagnetic circuit 921 does not output the electromagnetic wave signal. When the switch 913 is turned on, the electromagnetic wave output circuit 921 outputs the electromagnetic wave signal. The CPU 61 may receive the electromagnetic wave signal output from the electromagnetic wave output circuit 921 using an electromagnetic wave detector 97 (refer to FIG. 12 ). The electromagnetic wave detector 97 is provided inside the sewing machine 1 . The position of the electromagnetic detector 97 is not limited to the inside of the sewing machine 1 as long as the sewing machine 1 can receive the electromagnetic wave signal.
[0086] An electrical configuration of the sewing machine 1 and the ultrasonic pen 92 according to the third embodiment will be explained with reference to FIG. 12 . The third embodiment is different from the first embodiment in that the ultrasonic pen 92 includes the electromagnetic wave output circuit 921 and in that the sewing machine 1 includes the electromagnetic wave detector 97 . The electromagnetic wave output circuit 921 is connected to the switch 913 . The electromagnetic detector 97 is connected to the input/output interface 65 . When the electromagnetic wave detector 97 receives the electromagnetic wave signal output from the electromagnetic wave output circuit 921 of the ultrasonic pen 92 , the electromagnetic wave detector 97 outputs a signal to the CPU 61 via the input/output interface 65 .
[0087] Main processing according to the third embodiment will be explained with reference to FIG. 7 . At step S 11 , the CPU 61 determines whether the electromagnetic wave detector 97 has detected the electromagnetic wave signal output from the electromagnetic wave output circuit 921 of the ultrasonic pen 92 , instead of detecting the electrical signal output from the signal output circuit 914 of the ultrasonic pen 91 (step S 11 ). If the electromagnetic wave detector 97 has not detected the electromagnetic wave signal (NO at step S 11 ), the processing returns to step S 11 . If the electromagnetic wave detector 97 has detected the electromagnetic wave signal (YES at step S 11 ), the CPU 61 identifies a time at which the electromagnetic wave signal has been detected. The CPU 61 acquires the identified time as the transmission timing T 1 of the ultrasonic wave (step S 13 ). The CPU 61 stores the acquired transmission timing T 1 in the RAM 63 . Processing from steps S 15 to S 33 is performed in the same manner as in the first embodiment, and an explanation thereof is omitted here.
[0088] As explained above, in the third embodiment, the sewing machine 1 can identify the transmission timing of the ultrasonic wave by detecting the electromagnetic wave signal output by the ultrasonic pen 92 . In other words, there is no need to provide a cable to connect the ultrasonic pen 92 and the sewing machine 1 . As a result, there is no way the cable can be an obstruction to the operation. Thus, the user can easily specify the specified position on the work cloth 100 using the ultrasonic pen 92 .
[0089] In the third embodiment, the ultrasonic pen 92 may be provided with a known timer circuit and the timer circuit may be connected to the electromagnetic wave output circuit 921 . In this case, the electromagnetic wave output circuit 921 of the ultrasonic pen 92 may output an electromagnetic wave signal that notifies the CPU 61 of the time at which the switch 913 is turned on. The CPU 61 may receive the electromagnetic wave signal via the electromagnetic wave detector 97 and may identify the time notified by the electromagnetic wave signal. The CPU 61 may acquire the identified time as the transmission timing of the ultrasonic wave.
[0090] The electromagnetic wave signal output from the electromagnetic wave output circuit 921 may be an electromagnetic wave signal of an arbitrary frequency. For example, the electromagnetic wave signal may be a microwave or infrared light.
Fourth Embodiment
[0091] A fourth embodiment will be explained. As shown in FIG. 13 , the fourth embodiment is different from the third embodiment in that the sewing machine 1 is provided with a receiver 96 in addition to the receivers 94 and 95 and in that the ultrasonic pen 92 is not provided with the electromagnetic wave output circuit 921 , as will be described below in detail. The receiver 96 is provided on the left surface 17 of the pillar 12 . The receiver 96 has the same configuration as the receivers 94 and 95 . The receiver 96 is provided such that an opening (not shown in the drawings) of the receiver 96 is directed to the left. The CPU 61 may detect the ultrasonic wave using the receivers 94 , 95 and 96 and may calculate the specified coordinates E based on the detection timings T 2 of the receivers 94 , 95 and 96 . Unlike the first embodiment to the third embodiment, the CPU 61 does not acquire the transmission timing T 1 of the ultrasonic wave, and does not use the transmission timing T 1 when calculating the specified coordinates E. An electrical configuration of the sewing machine 1 according to the fourth embodiment is a configuration obtained by removing the electromagnetic wave detector 97 and the electromagnetic wave output circuit 921 from the block diagram shown in FIG. 12 that shows the electrical configuration of the sewing machine 1 according to the third embodiment.
[0092] A method for identifying a position on the work cloth 100 specified by the ultrasonic pen 92 will be explained with reference to FIG. 14 . The may user specify the specified position on the work cloth 100 by causing the pen tip 911 of the ultrasonic pen 92 to touch the work cloth 100 . The left-right direction and the up-down direction of FIG. 14 respectively correspond to the X direction and the Y direction. A direction from the near side to the far side of FIG. 14 corresponds to the Z direction. Coordinates D of the receiver 96 are denoted by (Xd, Yd, Zd). A distance between the specified coordinates E and the coordinates D of the receiver 96 is referred to as a “distance ED”.
[0093] The distance ED can be expressed by the coordinates B, C, D, and E based on the Pythagorean theorem. The distance ED and the coordinates D and E satisfy a relationship of the following Formula (7).
[0000] ( Xd−Xe ) 2 +( Yd−Ye ) 2 +( Zd−Ze ) 2 =( ED ) 2 Formula (7)
[0094] In the same manner as Formulas (1) and (2) described above, Formula (7) is the same as the equation of a spherical surface (whose radius is the distance ED), the origin of which is the coordinates D and on which the specified coordinates E is.
[0095] A time required from when the ultrasonic wave is transmitted from the ultrasonic pen 92 at the specified coordinates E to when the ultrasonic wave reaches the receiver 96 is referred to as a propagation time Td. In this case, the distance ED can be expressed by the following Formula (8).
[0000] ED=V×Td Formula (8)
[0096] Further, Formulas (4) and (8) can be transformed into the following Formulas (9) and (10).
[0000] EC=V×Tc=V ×( Tc−Tb )+ V×Tb Formula (9)
[0000] ED=V×Td=V ×( Td−Tb )+ V×Tb Formula (10)
[0097] A propagation time difference (Tc−Tb) in Formula (9) is the same as the difference between the detection timing T 2 at which the ultrasonic wave is detected via the receiver 95 and the detection timing T 2 at which the ultrasonic wave is detected via the receiver 94 . In a similar manner, a propagation time difference (Td−Td) in Formula (10) is the same as the difference between the detection timing T 2 at which the ultrasonic wave is detected via the receiver 96 and the detection timing T 2 at which the ultrasonic wave is detected via the receiver 94 . Accordingly, Formulas (9) and (10) can be transformed into the following Formulas (11) and (12). Detection timings at which the ultrasonic wave is detected via the receivers 94 , 95 , and 96 irrespectively referred to as T 2 b , T 2 c and T 2 d.
[0000] EC=V ×( T 2 c−T 2 b )+ V×Tb Formula (11)
[0000] ED=V ×( T 2 d−T 2 b )+ V×Tb Formula (12)
[0098] Following Formulas (13), (14), and (15) can be obtained by substituting Formulas (3), (11), and (12) into Formulas (1), (2), and (7).
[0000] ( Xb−Xe ) 2 +( Yb−Ye ) 2 +( Zb−Ze ) 2 =( V×Tb ) 2 Formula (13)
[0000] ( Xc−Xe ) 2 +( Ye−Ye ) 2 +( Zc−Ze ) 2 ={V ×( T 2 c−T 2 b )+ V×Tb} 2 Formula (14)
[0000] ( Xd−Xe ) 2 +( Yd−Ye ) 2 +( Zd−Ze ) 2 ={V ×( T 2 d−T 2 b )+ V×Tb} 2 Formula (15)
[0099] In Formulas (13), (14), and (15), the coordinates B (Xb, Yb, Zb), the coordinates C (Xc, Ye, Zc), the coordinates D (Xd, Yd, Zd), and the sonic velocity V are known values and are stored in advance in the ROM 62 . The detection timings T 2 b , T 2 c and T 2 d respectively correspond to times at which The CPU 61 detects the ultrasonic wave via the receivers 94 , 95 , and 96 (step S 43 , refer to FIG. 15 ). The value Ze of the specified coordinates E (Xe, Ye, Ze) is deemed to be zero. Based on the above, the values Xe, Ye, and Tb can be calculated by solving the simultaneous equations represented by Formulas (13), (14), and (15). In this manner, the specified coordinates E (Xe, Ye, Ze (=0)) on the work cloth 100 that are specified using the ultrasonic pen 92 are calculated.
[0100] Processing that is performed by the CPU 61 of the sewing machine 1 to identify the specified position will be explained with reference to FIG. 15 . The main processing is performed by the CPU 61 in accordance with the program stored in the ROM 62 . The CPU 61 may start the main processing when, for example, a command to perform sewing is input by a panel operation.
[0101] The CPU 61 determines whether at least one of the receivers 94 , 95 , and 96 has detected the ultrasonic wave transmitted from the ultrasonic pen 92 (step S 41 ). If none of the receivers 94 , 95 , and 96 has detected the ultrasonic wave (NO at step S 41 ), the CPU 61 determines whether the ultrasonic wave has been detected by at least one of the receivers 94 , 95 , and 96 after the main processing has been started (step S 61 ). If none of the receivers 94 , 95 and 96 has detected the ultrasonic wave after the main processing has been started (NO at step S 61 ), the processing returns to step S 41 . If the ultrasonic wave has been detected by at least one of the receivers 94 , 95 , and 96 after the main processing has been started (YES at step S 61 ), the CPU 61 determines whether a predetermined time period (for example, one second) has elapsed from when the ultrasonic wave has been detected for the first time after the start of the main processing (step S 63 ). If the predetermined time period has not elapsed (NO at step S 63 ), the processing returns to step S 41 . If the predetermined time period has elapsed (YES at step S 63 ), the CPU 61 displays an error message, on the LCD 15 , indicating that the ultrasonic wave has not been detected (step S 65 ). The processing returns to step S 41 .
[0102] If at least one of the receivers 94 , 95 , and 96 has detected the ultrasonic wave within the predetermined time period (YES at step S 41 ), the CPU 61 identifies a time at which the ultrasonic wave has been detected. The CPU 61 acquires the identified time as the detection timing T 2 (step S 43 ). The CPU 61 stores the acquired detection timing T 2 in the RAM 63 .
[0103] The CPU 61 determines whether all the receivers 94 , 95 , and 96 have detected the ultrasonic wave (step S 45 ). If at least one of the receivers 94 , 95 , and 96 has not detected the ultrasonic wave (NO at step S 45 ), the processing returns to step S 41 . If all the receivers 94 , 95 , and 96 have detected the ultrasonic wave (YES at step S 45 ), the CPU 61 calculates differences “T 2 c T 2 b ” and “T 2 d -T 2 b ” between the detection timings (step S 47 ). The CPU 61 calculates the distances EB, EC, and ED based on the calculated differences and the propagation time Tb (step S 49 ) (refer to Formulas (3), (11), and (12)). The CPU 61 substitutes the coordinates B (Xb, Yb, Zb), the coordinates C (Xc, Ye, Zc), the coordinates D (Xd, Yd, Zd), and the distances EB, EC, and ED into Formulas (13), (14), and (15), and solves the simultaneous equations. Thus, the CPU 61 calculates the specified coordinates E (Xe, Ye, Ze (=0)). In this manner, the CPU 61 identifies the position specified using the ultrasonic pen 92 , namely, the specified position (step S 51 ). Processing from steps S 27 to S 33 is performed in the same manner as in the first embodiment to the third embodiment (refer to FIG. 7 ) and an explanation thereof is thus omitted here.
[0104] As explained above, in the fourth embodiment, the sewing machine 1 can calculate the specified coordinates E using only the detection timings T 2 without using the transmission timing T 1 , unlike the first embodiment to the third embodiment. Therefore, there is no need to provide structural elements that are necessary to identify the transmission timing T 1 , such as the signal output circuit 914 (refer to FIG. 5 ) in the first embodiment, or the electromagnetic wave detector 97 and the electromagnetic wave output circuit 921 in the third embodiment. As a result, in the fourth embodiment, the specified coordinates E can be calculated with a simpler configuration than the configurations of the first embodiment to the third embodiment.
[0105] In the fourth embodiment, the three positions in which the receivers 94 , 95 , and 96 are provided are not limited to the lower left end and the lower right end of the head 14 of the sewing machine 1 and the left surface 17 of the pillar 12 . For example, all the receivers 94 , 95 , and 96 may be provided on the head 14 . For example, the receiver 94 may be provided on the rear side of the lower left end of the head 14 , the receiver 95 may be provided on the rear side of the lower right end of the head 14 , and the receiver 96 may be provided at substantially the center of the front side of the lower end of the head 14 .
[0106] The receivers 94 and 95 may be provided on the left and right sides of the presser bar 31 or the presser foot 30 , and the receiver 96 may be provided on the left surface 17 of the pillar 12 . The receiver 96 may be provided on the lower surface of the arm 13 .
[0107] The receivers 94 and 95 may be provided on the left and right sides of the presser bar 31 or the presser foot 30 , and the receiver 96 may be provided at substantially the center, in the left-right direction, of the front side of the lower end of the head 14 .
[0108] As explained above, the receivers 94 , 95 , and 96 may be provided on any of the head 14 , the presser foot 30 , the presser bar 31 , the left surface 17 of the pillar 12 and the lower surface of the arm 13 . The combinations of the portions of the receivers 94 , 95 , and 96 are not limited to those of the above-described fourth embodiment and the modified examples.
[0109] In a case where the embroidery unit 2 is attached to the sewing machine 1 and used, the receivers 94 , 95 , and 96 may be provided on the carriage 52 (refer to FIG. 8 to FIG. 10 ). In this case, the receivers 94 and 95 may be respectively provided at the front end and the rear end of the top surface of the carriage 52 , and the receiver 96 may be provided at substantially the center, in the front-rear direction, of the top surface of the carriage 52 . The receivers 94 and 95 may be respectively provided at the front end and the rear end of the top surface of the carriage 52 , and the receiver 96 may be provided on the rear side of the lower right end of the head 14 . The receivers 94 and 95 may be respectively provided at the front end and the rear end of the top surface of the carriage 52 , and the receiver 96 may be provided on the left surface 17 of the pillar 12 .
Fifth Embodiment
[0110] A fifth embodiment will be explained. As shown in FIG. 16 , a multi-needle sewing machine 3 (hereinafter referred to as a sewing machine 3 ) according to the fifth embodiment includes a plurality of needle bars. The sewing machine 3 is provided with receivers 131 and 132 . A configuration of the sewing machine 3 will be explained with reference to FIG. 16 to FIG. 18 . In the explanation below, it is defined that the upper side, the lower side, the left side, the right side, the near side, and the far side of FIG. 16 are respectively defined as the upper side, the lower side, the left side, the right side, the front side, and the rear side of the sewing machine 3 . That is, the direction in which a pillar 103 , which will be described below, extends is the up-down direction of the sewing machine 3 . The direction in which an arm 104 extends is the front-rear direction of the sewing machine 3 .
[0111] As shown in FIG. 16 and FIG. 17 , a main body 120 of the sewing machine 3 includes a support portion 102 , the pillar 103 , and the arm 104 . The support portion 102 is formed in an inverted U shape in a plan view and supports the whole of the sewing machine 3 . A left and right pair of guide grooves 125 are provided on a top surface of the support portion 102 . The guide grooves 125 extend in the front-rear direction. The pillar 103 extends upward from the rear end of the support portion 102 . The arm 104 extends forward from the upper end of the pillar 103 . A needle bar case 121 is mounted on the leading end (the front end) of the arm 104 such that the needle bar case 121 can be moved in the left-right direction. Ten needle bars (not shown in the drawings) that extend in the up-down direction are provided inside the needle bar case 121 such that the needle bars are arranged at equal intervals in the left-right direction. One of the ten needle bars that is in a sewing position may be slidingly moved in the up-down direction by a needle bar drive mechanism (not shown in the drawings) that is provided inside the needle bar case 121 . A sewing needle 135 can be attached to and detached from the lower end of each of the needle bars.
[0112] An operation portion 106 is provided on the right side of a central portion, in the front-rear direction, of the arm 104 . The operation portion 106 includes a liquid crystal display (LCD) 107 , a touch panel 108 , and an operation switch 141 . The LCD 107 may display various types of information, such as an operation image that is used for the user to input a command, for example. The touch panel 108 is used to accept a command from the user. The user may perform an operation of pressing the touch panel 108 using a finger or a dedicated touch pen. Hereinafter, this operation is referred to as a “panel operation”. The touch panel 108 detects a position pressed by the finger, the dedicated touch pen, or the like, and the sewing machine 3 determines the item that corresponds to the detected position. In this manner, the sewing machine 3 recognizes the selected item. By the panel operation, the user can select or set a pattern to be sewn and various types of conditions, such as sewing conditions. The operation switch 141 is used to command the start or stop of the sewing.
[0113] A cylinder bed 110 is provided below the arm 104 . The cylinder bed 110 extends forward from the lower end of the pillar 103 . A shuttle (not shown in the drawings) is provided inside the leading end (the front end) of the cylinder bed 110 . The shuttle may house a bobbin (not shown in the drawings) around which a lower thread (not shown in the drawings) is wound. A shuttle mechanism (not shown in the drawings) is provided inside the cylinder bed 110 . The shuttle mechanism (not shown in the drawings) may drive the shuttle. A needle plate 116 , which has a rectangular shape in a plan view, is provided on a top surface of the cylinder bed 110 . A needle hole (not shown in the drawings), through which the sewing needle 135 may pass, is formed in the needle plate 116 .
[0114] A left and right pair of thread spool stands 112 are provided at the rear side of a top surface of the arm 104 . Ten thread spools (not shown in the drawings), the number of which is the same as the number of the needle bars, can be placed on the pair of thread spool stands 112 . A upper thread (not shown in the drawings) may be supplied from a thread spool placed on one of the thread spool stands 112 . The upper thread may be supplied to an eye (not shown in the drawings) of the sewing needle 135 that is attached to the lower end of each of the needle bars, via a thread guide 117 , a tensioner 118 , a thread take-up lever 119 , and the like. The ultrasonic pen 91 may be connected to the sewing machine 3 via the cable 912 , in the same manner as in the first embodiment.
[0115] An embroidery frame movement mechanism 111 (refer to FIG. 18 ) is provided below the arm 104 . The embroidery frame movement mechanism 111 may detachably support an embroidery frame 184 (refer to FIG. 18 ). Various types of embroidery frames can be used as the embroidery frame 184 . The embroidery frame 184 may hold the work cloth 100 . The embroidery frame movement mechanism 111 may be driven by an X axis motor (not shown in the drawings) and a Y axis motor (not shown in the drawings), and may move the embroidery frame 184 in the front-rear direction and in the left-right direction.
[0116] The embroidery frame movement mechanism 111 will be explained with reference to FIG. 18 . The embroidery frame movement mechanism 111 includes a holder 124 , an X carriage 122 , an X axis drive mechanism (not shown in the drawings), a Y carriage 123 , and a Y axis movement mechanism (not shown in the drawings). The holder 124 may detachably support the embroidery frame 184 . The X carriage 122 is a plate member that is long in the left-right direction. A part of the X carriage 122 protrudes forward from the front face of the Y carriage 123 . The holder 124 is attached to the X carriage 122 . The X carriage 122 may move in the left-right direction (the X axis direction) using the X axis motor as a driving source.
[0117] The Y carriage 123 has a box shape that is long in the left-right direction. The Y carriage 123 supports the X carriage 122 such that the X carriage 122 can be moved in the left-right direction. The Y axis movement mechanism (not shown in the drawings) is provided with a left and right pair of moving members (not shown in the drawings). The moving members are coupled to lower portions of the left and right ends of the Y carriage 123 . The moving members pass through the guide grooves 125 (refer to FIG. 16 ) in the up-down direction. The moving members may be moved in the front-rear direction (the Y axis direction) along the guide grooves 125 , using the Y axis motor as a driving source. The Y carriage 123 coupled to the moving members and the X carriage 122 supported by the Y carriage 123 may be moved in the front-rear direction (the Y axis direction) along with the movement of the moving members. In a state in which the embroidery frame 184 that holds the work cloth 100 is attached to the holder 124 , the work cloth 100 is arranged between one of the needle bars and the needle plate 116 .
[0118] As shown in FIG. 16 to FIG. 18 , the receiver 131 is provided at the left end of a top surface of the Y carriage 123 , and the receiver 132 is provided at the right end of the top surface of the Y carriage 123 . The receivers 131 and 132 are configured to receive an ultrasonic wave. The receivers 131 and 132 have the same configuration as the receiver 94 . The embroidery frame 184 attached to the folder 124 is located at the front of the Y carriage 123 . Therefore, the receivers 131 and 132 are located above the work cloth 100 held by the embroidery frame 184 . Openings provided in the receivers 131 and 132 are directed forward.
[0119] Processing that is performed by a CPU (not shown in the drawings) of the sewing machine 3 to identify the specified position will be briefly explained with reference to FIG. 7 . In a case where the CPU detects an electrical signal output from the signal output circuit 914 of the ultrasonic pen 91 via the cable 912 (YES at step S 11 ), the CPU acquires the transmission timing T 1 (step S 13 ). In a case where the CPU detects the ultrasonic wave transmitted from the ultrasonic pen 91 via the receivers 131 and 132 (YES at step S 15 ), the CPU identifies a time at which the ultrasonic wave is detected by the receiver 131 and a time at which the ultrasonic wave is detected by the receiver 132 , and acquires the identified times as the detection timings T 2 (step S 17 ). The CPU calculates the specified coordinates E and identifies the specified position (steps S 21 to S 25 ), In a case where a panel operation is performed to start sewing (YES at step S 29 ), the CPU controls the X axis motor and the Y axis motor and thereby moves the embroidery frame 184 such that the position of the specified coordinates E on the work cloth 100 matches a needle drop point (step S 31 ). The CPU starts sewing on the work cloth 100 . The CPU drives the needle bar and the shuttle mechanism simultaneously with the embroidery frame being moved in the left-right direction (the X direction) and the front-rear direction (the Y direction). The sewing needle attached to the needle bar sews an embroidery pattern on the work cloth 100 held by the embroidery frame. In this manner, the embroidery pattern is sewn in the specified position on the work cloth 100 (step S 33 ).
[0120] The receivers 131 and 132 are provided on the Y carriage 123 . Therefore, the ultrasonic wave that is transmitted from the ultrasonic pen 91 when the pen tip 911 is in contact with the work cloth 100 is unlikely to be shielded by a hand or an arm of the user who uses the ultrasonic pen 91 (refer to condition (A)). The distance between the receivers 131 and 132 is separated by a length, in the left-right direction, of the Y carriage 123 . Therefore, the receivers 131 and 132 are sufficiently separated from each other (refer to condition (B)). The distances, in the X direction and the Y direction, from the needle hole (the origin) of the needle plate 116 to the receivers 131 and 132 are large (refer to condition (C)). The distances between the origin and the receivers 131 and 132 are not extremely large (refer to condition (D)). The receivers 131 and 132 are provided above the cylinder bed 110 (refer to condition (E)).
[0121] As described above, in the fifth embodiment, the sewing machine 3 is provided with the receivers 131 and 132 . The sewing machine 3 can identify the specified position by detecting the ultrasonic wave by each of the receivers 131 and 132 . The positions in which the receivers 131 and 132 are provided satisfy all the above-described conditions (A) to (E). Therefore, the sewing machine 3 can calculate the specified coordinates E more precisely and can perform sewing on the work cloth 100 . Further, the height from the cylinder bed 110 to the receivers 131 and 132 is sufficiently small. As a result, the influence caused by approximating the value Ze in Formulas (5) and (6) to zero may decrease. Therefore, the error of the calculated specified coordinates E may become small.
[0122] In the above-described fifth embodiment, the sewing machine 3 may be provided with the ultrasonic pen 92 that may output an electromagnetic wave signal, instead of the ultrasonic pen 91 . The receivers 131 and 132 may be provided in positions other than the Y carriage 123 . For example, the receivers 131 and 132 may be provided on a front surface of the pillar 103 and a lower surface of the arm 104 .
[0123] The sewing machine 3 may be provided with three receivers as in the fourth embodiment. The sewing machine 3 may identify the specified position based only on the detection timings. In this case, the receivers may be provided on any positions on the sewing machine 3 , without being limited to the Y carriage 123 . For example, the receivers may be provided on the front surface of the pillar 103 and the lower surface of the arm 104 .
Sixth Embodiment
[0124] The number of the receivers may be one. For example, it is assumed that the one receiver is the receiver 94 that is provided on the left lower end of the head 14 . Then, with respect to the coordinates B indicating the position of the receiver 94 , specified coordinates indicating the specified position specified by the ultrasonic pen 91 are referred to as coordinates F. At this time, the X coordinates of the coordinates B and the coordinates F are assumed to be the same. To simplify an explanation, Z coordinates are omitted in the following explanation. In other words, the coordinates B are assumed to be (Xb, Yb) and the coordinates F are assumed to be (Xb, Yf). In this case, it is possible to calculate a distance FB between the coordinates F and the coordinates B in the Y direction, based on the propagation time required for the ultrasonic wave transmitted from the ultrasonic pen 91 that is at the coordinates F of the specified position to reach the receiver 94 . The coordinates B are known values. Thus, with respect to the needle drop point that is the origin, the Y coordinate “Yf” of the coordinates F of the specified position can be calculated.
[0125] The apparatus and methods described above with reference to the various embodiments are merely examples. It goes without saying that they are not confined to the depicted embodiments. While various features have been described in conjunction with the examples outlined above, various alternatives, modifications, variations, and/or improvements of those features and/or examples may be possible. Accordingly, the examples, as set forth above, are intended to be illustrative. Various changes may be made without departing from the broad spirit and scope of the underlying principles. | A sewing machine includes at least one detecting portion, a processor, and a memory. The at least one detecting portion is configured to detect an ultrasonic wave that has been transmitted from a transmission source. The memory is configured to store computer-readable instructions that instruct the sewing machine to execute steps including identifying a position of the transmission source of the ultrasonic wave based on information pertaining to the ultrasonic wave that has been detected by the at least one detecting portion, and controlling sewing based on the position of the transmission source that has been identified. | big_patent |
FIELD OF THE INVENTION
[0001] The present invention relates to fabrics and textiles, and more particularly to cellulosic fabric or textile materials. More specifically, although not solely limited thereto, this invention relates to preparations for application onto a textile or fabric material comprising cellulosic fabric to enhance utility. More particularly, although not solely limited thereto, the present invention relates to methods of applications of functional utility enhancing preparations onto a cellulosic material, and textile articles comprising cellulosic fabric material applied with such preparations.
BACKGROUND OF THE INVENTION
[0002] Textile articles comprising cellulosic fabric or textile materials such as cotton, linen, or other natural fibers are popular because of their various properties. In many textile goods, it is desirable to add functional additives to enhance the utility of such textile goods. For example, it is desirable to enhance ultraviolet protection, anti-bacterial, odor absorbing properties, or other useful properties to textile goods. However, the stability or performance of known textile articles comprising cellulosic fabric materials with functional additives to enhance functional utility is not very acceptable. For example, known clothing articles made from cellulosic fabric materials with functional additives for enhancing ultraviolet protection or bacteria resistance rapidly lose the added functional enhancement after several washing cycles.
[0003] Therefore, it is desirable if textile articles with improved functional durability could be provided.
SUMMARY OF INVENTION
[0004] According to the present invention, there is provided a preparation for application onto a cellulosic fabric or textile material, wherein the preparation comprises a blended mixture of wool particles or wool powder, and a binding agent, wherein the functional additive is carried by the wool particles. The wool particles or wool powder is preferably of macrofibril size or below.
[0005] A preparation comprising wool particles or wool powder of the macrofibril size as carriers for functional additives has demonstrated an exceptional functional additive-carrying and retention ability which enhances the durability of functional enhancements of a cellulosic fabric material.
[0006] Using ultrafine wool fibre in such preparations is both environmentally friendly and economical because wool fibres which are too short and weak to be spun into wool yarns are often scrapped.
[0007] According to another aspect of the present invention, there is provided a preparation for application onto a cellulosic fabric material comprising a mixture of powdered bamboo fibre, carrier agents, and binding agents. Preferably, the non-charcoal fibrous bamboo powder is nano-sized having an ultrafine particle size, say, of 1 μm or below. It is noted that fabric materials treated with ultrafine bamboo fibre powder has good moisture management properties.
[0008] According to another aspect of the present invention, there is provided a method of preparing a preparation for application onto a cellulosic fabric materials comprising wool as functional additive carrier, the method comprising:
Pulverizing wool to obtain ultrafine wool powder of macrofibril size, Forming an ultrafine wool suspension using the ultrafine wool powder.
[0011] The method may comprise the step of pulverizing the wool powder into a suspension of ultrafine wool particles by ultrasonic crushing.
[0012] According to yet another aspect of the present invention, there is provided a method of preparing a preparation comprising bamboo fibre as a functional additive, the method comprising:
Pulverizing bamboo fibre to obtain coarse bamboo powder, Adding 0.5-2g/l wetting agent and 4-10g/l bamboo powder into water to form a suspension, and Pulverising the coarse bamboo powder in the suspension into ultrafine bamboo powder.
[0016] The functional additive may include additives for ultraviolet protection, anti-bacteria, or other clothing functions.
[0017] The wool particles or wool powder may have a size of 200 nm or below.
[0018] The wool particles or wool powder may have a helix or helical structure capable of carrying the functional additives.
[0019] The functional additive may comprise an anti-UV (ultraviolet light) agent, such as zinc oxide, or titanium oxide, bamboo powder.
[0020] The functional additive may comprise one or a combination of anti-bacterial agents such as nano-silver, zinc oxide, titanium oxide, non-charcoal bamboo powder, or other comparable agents.
[0021] The functional additive may be in ultrafine powder form having a nano-sized particle of between 100-200 nm.
[0022] The non-charcoal fibrous bamboo powder may be ultrafine having a particle size of less than 1 μm.
[0023] The binding agent may be acrylic copolymer based, and the acrylic copolymer may be aqueous dispersed.
[0024] The carrier agent may comprise wool particles or wool powder of macrofibril size and below.
[0025] The functional additives may comprise an anti-UV (ultraviolet light) agent, such as zinc oxide, or titanium oxide, or other functional comparable agents.
[0026] The functional additives may comprise anti-bacterial agents such as nano-silver, zinc oxide, titanium oxide, or other functional comparable agents.
[0027] The cellulosic fabric material, such as a fabric material may comprise cotton or linen, which may be applied, bonded, deposited with a preparation of any of the preparation.
[0028] The cellulosic fabric material may comprise pulverized bamboo blended into the fabric material.
[0029] The preparation may be bonded to or deposited onto the cellulosic fabric.
[0030] The bonding or deposition may be by printing, padding or foam application.
[0031] The method may comprise adding 0.5-2g/l wetting agent and 4-10g/l ultrafine wool powder into water to form the suspension.
[0032] The method may comprise homogenizing the suspension.
[0033] The pulverizing step converting coarse bamboo powder into ultrafine bamboo powder may comprise ultrasonic pulverizing of the coarse bamboo powder followed by homogenization of the suspension containing the ultrafine bamboo powder.
[0034] The duration of the ultrasonic pulverizing of the coarse bamboo powder into ultrafine bamboo powder and the homogenization process respectively may last for 20-40 minutes and 5-15 minutes.
[0035] The method may comprise bonding or depositing the preparation to the textile material by printing, padding or foam application.
[0036] The preparation may be provided to provide enhanced moisture management, wicking and/or wrinkling resistance properties of the article.
BRIEF DESCRIPTION OF DRAWINGS
[0037] Embodiments of the present invention will be explained by way of example and with reference to the accompanying drawings, in which:—
[0038] FIG. 1 is a T-shirt illustrating an embodiment of the present invention,
[0039] FIG. 2 is a schematic diagram of wool fibre structure,
[0040] FIG. 3 is a schematic diagram illustrating a wool fibre showing cuticle and corticle cells,
[0041] FIG. 4 is a chart showing the UPF of the t-shirt of FIG. 1 with respect to the number of washes,
[0042] FIG. 5 is a chart showing wicking performance of the t-shirt of FIG. 1 with respect to number of washes, and
[0043] FIG. 6 are bar charts showing recovery angles of fabric materials treated and not treated with the present invention.
DETAILED DESCRIPTION OF EMBODIMENTS
[0044] A cotton tee shirt (“T-shirt”) 100 as an example of a textile article comprising a cellulosic fabric or textile material 110 and applied with a preparation 120 comprising ultrafine wool powder is depicted in FIG. 1 . The preparation is an aqueous suspension comprising a functional additive, ultrafine wool powder, and an aqueous binder. The ultrafine wool powder is a wool powder of the macrofibril size which has been found to demonstrate exceptional carrying and retention capability for functional additives. The term “functional additive” in the present context means an additive which confers useful function or utility to the article to which it is applied. Examples of useful function in the present context include ultraviolet (“UV”) protection, anti-bacterial properties, etc.
[0045] Examples of known functional additives for ultraviolet protection and/or anti-bacterial property include: zinc oxide or ultrafine zinc oxide, titanium dioxide or ultrafine titanium dioxide.
[0046] Examples of new functional additives according to the present invention include: ultrafine bamboo powder for improving moisture management properties of the fabrics.
[0047] An exemplary preparation of a first embodiment of a preparation will be described below.
A Preparation Comprising Ultrafine Wool Powder as Carrier
Pulverization of Wool Fibre
[0048] Firstly, wool fibre is pulverized into ultrafine powder as follows:
1. Cutting the wool fibres into short length of around 1-2 cm 2. Pulverizing the wool fibre into wool powder by means of rotary blade. 3. Adding 0.5-2 g/L wetting agent and 4-10 g/L wool powder into water. 4. Pulverizing the wool powder into ultrafine wool suspension by means of ultrasonic crusher and followed by homogenizer, where the ultrasonic and homogenizing operation duration are 20-40 minutes and 5-15 minutes, respectively.
Addition of Additives
[0053] After the wool suspension has been formed, functional additives are added to form the preparation.
[0054] In the present invention, wool fibre is pulverized into ultrafine wool particles and then used as a carrier for carrying chemical onto the cellulosic fibre or its blends fabric to provide multi-functional properties of cellulosic fibre or its blends fabric. The chemicals selected to be carried by ultrafine wool particles include ultrafine titanium dioxide, ultrafine zinc oxide and ultrafine bamboo particles. The ultrafine wool powder is attached onto the cotton fabric by means of aqueous dispersion of acrylic copolymer binder.
Wool Fibre
[0055] Wool consists of two types of cell: the internal cells of the cortex and external cuticle cells that form a sheath around the fibre as shown in FIG. 2 .
[0056] The cuticle cells (or scales) overlap like tiles on the roof, cover the wool fibre surface. The waxy, hydrocarbon coating, chemically bound to the surface of each scale acts as ‘shower-proof’ of the wool fibre providing wool natural water repellency in nature. The cuticle cells represent about 10% weight of wool fibre.
[0057] The cortex of wool comprises around 90% of the fibre. It is composed of overlapping, spindle-shaped cells, as shown in FIG. 2 . The cell membrane complex (CMC) hold the cortical cells together, also separates them from those of the cuticle. The CMC is a continuous region, containing relatively lightly-crosslinked proteins and waxy lipids, which extend throughout the whole fibre. It represents around 5% of the total fibre mass. As the CMC is only slightly crosslinked, it is also more susceptible to chemical attack. It also provides a channel where dyes and chemicals can diffuse in and out of wool.
[0058] Fine wool fibres consist of two major types of cortical cell (ortho- and para-). Coarser types of wool (diameters>>25 um) tend to have less distinction of segmentation of the two types of cortical cells. The orthocortex is always orientated towards the outside radius of the crimp. This occurs as a result of the two segments rotating around the fibre in phase with the crimp.
[0059] There are different structures of the proteins in wool between the various regions of the fibre. Some of the proteins in the microfibrils are helical, like a spring, in structure. For these kinds of proteins, the protein chains of amino acid residues were coiled into a helical structure. In general, there are 36 amino acid residues in 10 turns of the helix. Present evidence suggests that two α-helices are twisted and coiled together as in a rope. This provides flexibility, elasticity, resilience and good wrinkle recovery properties.
[0060] Other proteins, especially in the matrix that surrounds the macrofibrils, is more amorphous in structure and it absorbs a relatively large amount of water without feeling wet. The matrix proteins are also used for absorbing and retaining large amount of dyestuffs. (source: The chemical and physical structure of merino wool, http://www.csiro.au/files/files/p9ti.pdf)
[0061] During the pulverization of wool fibre, the roof-like structure of cuticle cells (scales) is damaged. Since the cuticle cells (scales) of the wool acts as a barrier for water and chemicals to enter the wool fibre, the damage of cuticle cells (scales) allows the chemicals and water diffuse into the internal structure of wool more easily and freely. The chemicals and water is then passed through the slightly crosslinked cell membrane complex for entering the cortex cells of the wool fibres. In the cortex cells, the helical structure spring like macrofibril acts as a storage site for carrying chemicals. In addition, the amorphous structure of matrix surround macrofibrils provides space for water absorption. The chemicals suspended in the water, can therefore be present in the matrix region.
[0062] It is appreciated that the above characteristics of wool fibre is beneficial for the present invention.
A Preparation Comprising Ultrafine Bamboo Powder
[0063] In another embodiment, powdered fibrous bamboo, or bamboo powder (not charcoal) is used as a functional additive. Initially, bamboo powder is obtained from fibrous bamboo as contrast to charcoal or bamboo pulp.
Pulverization of Bamboo Powder
[0064] The pulverization process is performed step by step as follows:
1. Cutting the bamboo fibres into short length of around 1-2 cm 2. Pulverizing the bamboo fibre into bamboo powder by means of rotary blade. 3. Adding 0.5-2 g/L wetting agent and 4-15 g/L bamboo powder into water. 4. Pulverizing the bamboo powder suspension into ultrafine bamboo suspension by means of ultrasonic crusher and followed by homogenizer, where the ultrasonic and homogenizing operation duration are 20-40 minutes and 5-15 minutes, respectively. 5. The ultrafine bamboo suspension is well prepared.
Formation of Bamboo Powder and Wool Solution
[0070] The wool and bamboo are first pulverized into ultrafine powder suspension and they are mixed well to form an ultrafine wool, bamboo suspension, which the volume ratio of ultrafine bamboo to ultrafine wool suspension ranges from 1:1 to 1:2. After the preparation of ultrafine wool and bamboo solution, ultrafine zinc oxide, ultrafine titanium dioxide is added into the suspension and mixed well first. The aqueous dispersion of acrylic copolymer binder is then added into the above suspension to form a finishing paste.
Recipe of Finishing Paste
[0000]
Ultrafine wool suspension (with solid content of 4 g-10 g wool powder)—200-400 g/L
Ultrafine bamboo suspension (with solid content of 4 g-10 g bamboo powder)—200-400 g/L
Ultrafine zinc oxide—5-20 g/L
Ultrafine titanium oxide—1-10 g/L
Aqueous dispersion of acrylic copolymer binder—200-600 g/L
0-25 g/L thickener
[0077] The finishing paste is then homogenized and made into finer solution to provide better handfeel through treating with ultrasonic crusher for 10-20 mins. After the ultrasonic crushing, the viscosity of the finishing paste is reduced that the finishing paste turns into solution form. This treatment solution is ready to be applied onto the cellulosic fibre or its blends fabrics by padding method.
Application of the Preparation to the Article
[0078] Printing is a process wherein the coloring or treating material, usually in the form of a paste, is deposited onto the surface of the fabric which is then typically further treated with steam, heat or chemicals for fixation of the coloring or treating material onto the fabric. The printing process affixes the treating material, to the surface of the yarns or fabrics with the addition of a binder. Binders can be considered as adhesives. Roller printing, flat screen printing and rotary screen printing, are widely used in commercial production. In present invention, both these three kinds of printing methods are suitable to apply the treatment paste onto the cellulosic or its blends fabrics.
[0079] In another embodiment, it has been found that certain foam application processes may provide an alternative method to applying treatment paste onto the fabrics. One system, known as the chemical foam system (CFS), is a highly controlled, patented system that has been used to accurately apply foamed, water soluble or water dispersible chemicals at very low moisture levels onto substrates such as textiles, carpets, non-woven, and paper and the like. In the context of the present invention, the treatment paste is for use on knitted or woven fabrics. Applying foam to woven and knitted fabrics use a pressure plenum which provides finite control over the chemical application to the fabrics with respect to uniform, quality and controlled penetration of the fabric. Foam application may be advantageous to the extent that the surface area of the chemical, when foamed, more closely matches the surface area of the fibers or yarns while greatly reducing water usage.
[0080] After the treatment by either padding, printing or foam application method, the treated fabric is first dried and curried under high temperature of above 150° C. by using stenter. After curing, in order to enhance handfeel of the treated fabric, the unfixed paste and chemicals are removed by detergent washing, followed by drying with the aid of tumble dryer.
[0081] After the preparation of fabric, the wicking and ultraviolet protection properties of the untreated and treated fabric are evaluated and compared. In present invention, 100% cotton single jersey is chosen as an example to be treated with the zinc oxide, titanium dioxide, ultrafine bamboo, ultrafine wool paste by printing method. The ultraviolet protection property and wicking of untreated control and treated fabrics are compared as shown in FIGS. 4 and 5 respectively.
[0082] The ultraviolet protection ability of the fabrics is evaluated in term of ultraviolet protection factor (UPF) value, which is determined by following the testing method of AATCC 183 standard. The ultraviolet protection of fabric is classified into different categories by following ASTM D6603 as shown in Table 1. In order to study the washing durability of the treated fabric, the UPF value of untreated and treated fabric for before washing and after 1, 5, 10, 15, 20 and 25 cycles of washing were tested. The fabrics were washed by following the washing condition mentioned in AATCC 135/150-2004 testing method.
[0000]
TABLE 1
Ultraviolet Protection Classification Category
Effective UVR
Transmission
UPF Range
Protection Category
%
UPF Rating
15-24
Good Protection
6.7 to 4.2
15, 20
25-39
Very Good Protection
4.1 to 2.6
25, 30, 35
40 to 50, 50+
Excellent Protection
≦2.5
40, 45, 50, 50+
[0083] FIG. 4 show that the UPF value of before and after 1, 5, 10, 20 and 25 cycles of washing untreated control single jersey are all under 7. They are not classified into any ultraviolet protection rating. For the zinc oxide, titanium dioxide, ultrafine bamboo, ultrafine wool paste treated single jersey fabric, however, has much more higher UPF value than untreated fabric. The UPF value of 25 cycle washes treated fabric is 17.03, which is still classified into good ultraviolet protection category. The zinc oxide, titanium dioxide, ultrafine bamboo, ultrafine wool paste treated single jersey fabric are classified to have excellent ultraviolet protection before washing, very good protection after 1 and 5 cycles of washing and good protection category after 10, 15, 20 and 25 cycles of washing.
[0084] Besides of providing ultraviolet protection, the zinc oxide, titanium dioxide, ultrafine bamboo, ultrafine wool paste treated fabric provides comfort to the wearers. Comfort properties of textiles are very important. Among all of the comfort properties, good absorption and easy drying are probably the major requirements.
[0085] The quick drying capability of textiles (absorption of moisture and perspiration) is usually obtained from the special contour of fibers/fabrics, special weave structure or absorbent finishing. Textiles which transfer moisture and dry quickly mostly depend either on capillary action in their fibers/fabrics or moisture absorbency to quickly absorb moisture on skin surface and wick it away to textile surface. Influenced by diffusion and air convection on textile surface, the moisture quickly evaporates, leaving the textile dry. These textiles are especially to be used in hot climates or during intense workouts. They absorb large amounts of perspiration; promote moisture to outer surface so as to keep the body dry. The capability of a textile to absorb water is called hygroscopicity and is measured by ‘wicking height’ and ‘water diffusion speed’.
[0000] (source: http://tft.ttfapproved.org.tw/e_tft/introduction/ftts-fa-004.asp)
[0086] “The Committee of Conformity Assessment of Accreditation and Certification on Functional and Technical Textiles” supported by the Taiwan Textile Research Institute's board of directors has developed 18 industrial standards for evaluation of functional clothing and household textiles. ‘Specified Requirements of Moisture Transferring and Quick Drying Textiles, FTTS-FA-004’ is one the industrial standards for evaluation the moisture management properties of textile materials.
[0087] In present invention, the moisture management of the zinc oxide, titanium dioxide, ultrafine bamboo, ultrafine wool treated are evaluated and compared with the untreated fabric in terms of wicking by referring to the FTTS-FA-004 testing method.
Wicking
[0088] Wicking is the spontaneous flow of a liquid in a porous substrate, driven by capillary force.(source: http://www.ftts.org.tw/eaboutus.aspx) In present invention, the wicking of the ultraviolet protection, the zinc oxide, titanium dioxide, ultrafine bamboo, ultrafine wool paste treated fabric is tested and compared with the control fabric by slightly modifying the standard method—Specified Requirements of Moisture Transferring and Quick Drying Textiles FTTS-FA-004. This testing is a method to determine the water absorption rate that showing the capillary ability of a strip of fabric against gravity. According to the FTTS-FA-04 testing method, when knitted fabrics are tested, five specimens with the size of 200 mm×25 mm in wale and course direction are taken respectively. The specimens are fixed onto the horizontal bar supported over the water surface of water bath with temperature 20±2° C. The horizontal bar is adjusted to lower position so that the lower ends of the specimens are immersed with 0.5 cm depth into the water for 10 minutes. The wicking length is recorded by capillarity to 1 mm. The test result is expressed by the mean value of five measurements of the height of water raised in wale and course directions respectively. (source: http://www.ttfapproved.org.tw/eng/cons/E04/download/FTTS-FA-004.doc) In present invention, this testing method is modified by not only recording the wicking height at immersing in water for 10 minutes, but recording the wicking height for immersing in water for 1, 3, 5, 10, 15, 20, 25 and 30 minutes so as to collect enough data for the wicking curve as shown in FIG. 5 .
[0089] By comparing the wicking curve of untreated and treated cotton single jersey fabric, the wicking of zinc oxide, titanium dioxide, ultrafine bamboo, ultrafine wool treated fabric is much higher than the untreated cotton fabric in both warp and weft directions. This shows that the zinc oxide, titanium dioxide, ultrafine bamboo, ultrafine wool treating enhances the water absorption and capillary ability of the fabric.
Wrinkle Recovery
[0090] By having helical spring like structure macrofibrils, wool has good flexibility, elasticity, resilience and good wrinkle recovery properties. In present invention, the ultrafine wool powder not only works as a carrier for carrying chemicals, but also gets help in enhancing the wrinkle recovery of cotton fabrics. In present invention, 100% cotton poplin woven fabrics are undergone zinc oxide, titanium dioxide, ultrafine bamboo, ultrafine wool treatment by following the preparation procedure same as that of single jersey. The wrinkle recovery of those before washes and after 5, 10, 15, 20 and 25 washes zinc oxide, titanium dioxide, ultrafine bamboo, ultrafine wool treated 100% cotton poplin fabrics are tested and compared with that of control untreated fabric by following the AATCC 66-1998 testing method. The washing conditions for the times of washing follows the AATCC 135/150-2004. During the testing, the test specimen is folded and compressed under controlled conditions of time and force to create a folded wrinkle. The test specimen is then suspended in a test instrument for a controlled recovery period after which the recovery angle is recorded. FIG. 6 demonstrates that the wrinkle recovery angle of the treated fabric is more than double than that of the control untreated fabric even after 25 times of washing. The enhancement in wrinkle recovery of the fabric after treatment is due to the presence of ultrafine wool powder which intrinsically exhibits wrinkle resistant properties of wool. When ultrafine wool powder is applied onto cotton fabric, the two ends of helical macrofibrils of wool are attached to the cotton fabrics to act like a spring to provide wrinkle resistance to the cotton fabrics.
Anti-Bacterial
[0091] Ultrafine zinc oxide and titanium dioxide are carried by ultrafine wool powder to be applied onto the fabric. Ultrafine zinc oxide and titanium dioxide not only enhance the ultraviolet protection of the fabric, they can provide anti-bacterial properties to the fabrics. In present invention, the anti-bacterial properties and its safety are tested according to FZ/T 73023-2006 standard.
[0092] When comparing the bacteria inhibition effectiveness of a single cotton jersey fabric materials untreated and treated with the functional additives as indicated by a reference inhibition percentage, it is noted that the antimicrobial activity of the cotton fabric treated with zinc oxide, titanium dioxide, ultrafine bamboo, ultrafine wool treated fabric in ultrafine powder form is much higher than that of the untreated cotton fabric. For example, experiments show that the inhibition percentage of antimicrobial activities of treated and untreated cotton single jersey fabric after 10 washes are greater than 90% and 13.95% respectively. It is understood that a higher inhibition percentage of antimicrobial activity means a higher anti-bacterial properties of the fabrics. Accordingly, the results confirm that the zinc oxide, titanium dioxide, ultrafine bamboo, ultrafine wool treatment enhances the anti-bacterial properties of the fabric effectively.
[0093] While the present invention has been explained with reference to the exemplary embodiments, it would be understood that the embodiments are only non-limiting examples for illustrating the invention and should not be construed as the only ways to practice the invention. For example, while reference has been made to textile or fabric materials, it will be understood by persons skilled in the art that blended (as contrast to non-blended) textile materials are included without loss of generality. Furthermore, it will be understood that the term macrofibril is used as an abbreviation to refer to wool particles of a size which demonstrates functional additive carrying capability as described herein. Actual dimensions of a macrofibril may refer to, but not limited by, that illustrated in FIG. 2 herein. | A preparation for application onto a cellulosic fabric or textile material includes a blended mixture of wool particles or wool powder, and a binding agent. The functional additive is carried by the wool particles. The wool particles or wool powder is preferably of macrofibril size or below. Such a preparation exhibits exceptional functional additive-carrying and retention ability which enhances the durability of functional enhancements of a cellulosic fabric material. In another embodiment, the preparation includes a mixture of powdered bamboo fibre, carrier agents, and binding agents. Preferably, the non-charcoal fibrous bamboo powder is nano-sized having an ultrafine particle size, e.g., 1 μm or below. Fabric materials treated with ultrafine bamboo fibre powder have good moisture management properties. | big_patent |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The field of the present invention relates to frame quilting machines which are large table-like structures used to sew patterns into large textile items; in particular bedspreads and quilts. The field of the present invention also relates to industrial sewing machine apparatus and processes used to sew patterns and stitching into large fabrics, which sewing operation is not easily performed on conventional sewing machine. The field of the present invention also relates to machines which include a method of duplicating a selected pattern over an entire bedspread or quilt. Finally, the field of the present invention relates to computer controlled quilting machines wherein the stitching pattern of the sewing machine head and the table movement of the frame relative to the sewing machine head are both controlled by computers or process controllers.
2. Description of the Prior Art
Industrial sewing machine operations are known in the prior art. Patterns and stitching into fabrics is commonly performed on industrial sewing machines. The operator hand guides the fabric between the needle and the sewing machine table and the pattern is sewn into the fabric. This process is practical for small pieces of fabric and is commonly done on piece goods such as garments. When handling larger pieces of fabric such as a roll of fabric, a metnod known in the prior art is roll to roll sewing. The sewing machine head is located along an X-axis and the material is unwound from a roll and caused to move transverse to the sewing machine head such that the fabric moves along a Y-axis. The sewing machine sews a stitch into the large fabric as the head moving along the X-axis and the fabric moving along the Y-axis intersect each other. The fabric is then wound onto a second receiving roll.
When sewing a very large piece of fabric such as a bedspread or quilt, a frame quilting machine is used. The frame quilting machine comprises a large frame, usually made of metal, onto which the fabric to be sewn is spread. Commonly, the pattern is sewn by a sewing machine guided by a computer into which a predetermined pattern has been programmed. The fabric remains stationary on the frame and the sewing machine head moves along the fabric and stitches in the predetermined pattern.
The current method for computer programmable quilting patterns uses a digitizer/cursor board with a method of plotting patterns. It is also used in the design of patterns and is accomplished on a scaled down version of the patterns. Plotting is accomplished using a mouse for indexing points on an XY axis. The points are programmed and followed through use of the computer. The prior art uses standard patterns which are preprogrammed into the computer and selected individualized patterns which are created as the bedspread or quilt is on the machine.
A major problem with all prior art embodiments is that the stitching function of the sewing machine needle and the frame table movement in the X and Y directions are controlled by a single computer. As a result, when it becomes necessary to program or reprogram the machine for a new stitch or pattern, or to make modifications in the existing stitch or pattern, all of the movements in the stitch function and table movement function must be reprogrammed. This results in an enormous amount of work in that thousands of combined stitch and movement operations must be reprogrammed and the effort takes many hours and sometimes days.
The inventors have previously filed three patent applications which are presently co-pending. These patent applications are as follows:
1. Patent application Ser. No. 07/220,734 filed 07/18/88 for "Automatic Quilting Machine For Specialized Quilting Of Patterns Which Can Be Controlled By A Remote Joy Stick And Monitored On A Video Screen".
2. Patent application Ser. No. 07/247,696 filed 09/22/88 for "Automatic Quilting Machine For Specialized Quilting Of Patterns Which Can Be Controlled By A Remote Joystick And Monitored On A Video Screen Including Pattern Duplication Through A Reprogrammable Computer".
3. Patent application Ser. No. 07/336,007 filed 04/10/89 for "Automatic Quilting Machine For Specialized Quilting Of Patterns Which Can Be Created By A Scanner Or On A Video Screen Utilizing Computer Graphics In Conjunction With A Reprogrammable Computer Which Includes Computer Aided Design".
The prior art known to the inventors is discussed in the above three referenced patent applications. None of this prior art discloses the concept of separate computers or process controllers to control the sewing machine functions and the frame table movements so that each can be independently programmed or reprogrammed to make adjustments or changes in either the stitch or accessory functions such as trim, etc. or in the table movement in the X and/or Y direction.
Therefore, there is a significant need for a system which selectively breaks down the the three functions of sewing machine stitch pattern, X movement and Y movement into individualized computer program modes so that reprogramming of one element does not require reprogramming the entire system.
SUMMARY OF THE PRESENT INVENTION
The present invention relates to an automatic quilting machine for use in stitching individual selected patterns into a large fabric such as a bedspread or quilt. The bedspread or quilt is stretched on a large metal frame which is mounted on a table which can be moved in the X-direction, the Y-direction, or any X-Y combination direction, either through a manually operated automatic joystick or mouse or through an automatic remote control directed by a computer. The sewing machine head is mounted on a cross beam which is aligned at the approximate center point of the metal frame on which the fabric is stretched. The needle of the sewing machine head can stitch a pattern into any location in the fabric and the metal frame is moved in any direction relative to the fixed sewing machine head in order to bring the desired stitch location on the fabric into alignment with the sewing machine head.
In addition, the present invention also relates to a reprogrammable function integrated into the system wherein the operator first manually draws the desired pattern on a monitor using conventional graphic systems apparatus such as a mouse. The tracing function is facilitated through a computer aided design program which automatically converts the drawn pattern into computer language which then can cause the stitch to be reprogrammed at any desired location on the fabric. An example of such a computer aided design program is AutoSketch-R or AutoCad-R which are federally registered trademarks of Autodesk, Inc. At the end of this step, the traced pattern is stored into the memory of the computer as a digitalized image of the pattern embodied in the computer aided design program. The computer aided design program then permits the patterns to be duplicated as often as desired after information concerning the dimension of the fabric and the desired locations for the repeated pattern are input into the computer program. At the end of this step, the computer will have generated and stored a digitalized map of the entire area to be quilted. In the third step of the process, the operator will command the start of the automated quilting generated process and the computer will cause the machine to to the marked locations in the computer which are comparable to the marked locations on the bedspread or quilt and repeat the individualized pattern which was created by the operator. The commands are placed into the remote control operation which causes the movement of the frame quilting table.
Further, the present invention also relates to a system wherein the sewing machine function is controlled by one computer usually connected to the sewing machine head and the quilting table motion in the X-direction, Y-direction, and X-Y direction is controlled by a separate computer. When it is desired to change a sewing machine computer function such as a stitch or accessory functions such as trim, the sewing machine computer can be independently reprogrammed. When it is desired to change the pattern, the separate computer controlling the X-Y table movement direction can be independently reprogrammed. It is not necessary to reprogram both functions which is an enormous task. Instead, only one of the functions needs to be reprogrammed, thereby greatly simplifying the process.
In general, this is a frame quilting machine. A bedspread, comforter, quilt, etc. is stretched securely on a metal frame. It is placed on an X-Y positioning table for movement controlled through a sewing machine. The sewing machine has been modified and mounted on a steel frame (two cross beams top and bottom) that can accommodate twelve feet by twelve feet six inches of stitching dimensions. Of course it can be made larger or smaller. The machine has been engineered and built to satisfy increased production needs of manufacturers who supply "customer, hand-guided, or outline quilted patterns". The key elements of the present invention are: (a) sewing and auxiliary functions; (b) the electronic coordination of movement and sewing speeds relative to direction and distance of travel of the remote control apparatus; (c) a reprogrammable computer into which the individualized pattern which can be converted into machine language by the computer aided design program of the computer can be programmed into the computer and after at least one point for each subsequent pattern duplication has been marked into the computer aided design computer program, the individualized pattern can be duplicated in each desired location of the bedspread or quilt through activation of the reprogrammable computer which commands the remote control apparatus to move the quilting table relative to the sewing needle; and (d) two separate computers, one which controls the sewing machine function and one which controls the table movement in the X-direction, Y-direction and combination X-Y direction.
It has been discovered, according to the present invention, that if a frame quilting machine can be moved relative to a fixed sewing machine head in the X-direction, the Y-direction or any X-Y combination direction by a remote operating means such as a computer, and the frame quilting machine comprises a metal table or frame on which a bedspread or quilt is stretched such that the surface area of the bedspread or quilt is open and unobstructed, and the metal frame can move relative to and between a pair of cross beams which hold a sewing machine head and plate, then an operator can cause a precise pattern to be programmed into the computer through the use of a computer aided design feature which converts the graphic picture pattern into machine readable language and is stored in the memory of the computer, which in turn through a remote control apparatus can cause the programmed pattern to be precisely stitched into the bedspread or quilt by moving the metal frame or quilting table relative to the fixed cross beams housing the sewing machine components in any desired direction to arrive at any desired location on the bedspread or frame where a stitch or pattern is to be sewn, and further the sewing function or the pattern through the table movement can be separately changed by reprogramming the sewing machine computer or the table movement computer separately.
It has further been discovered, according to the present invention, that if one computer controls the sewing function of the sewing machine and a second computer controls the movement of the quilting table, then reprogramming either computer is greatly simplified.
It is therefore an object of the present invention to provide an apparatus by which an operator can remain at a remote location from a large frame quilting machine and cause a precise pattern to be sewn into the large bedspread, comforter, quilt, or other fabric which is held on the metal frame or table of the frame quilting machine, through the use of a computer aided design feature in which the pattern can be drawn on a monitor by movement of a cursor which is guided by a remote movement apparatus such as a joystick or mouse and the drawn pattern can thereafter be automatically converted into machine readable language through use of a computer aided design program such as AutoSketch-R or AutoCad-R, which can automatically duplicate a graphic pattern into machine readable form. Thereafter, the pattern is stored in the memory of the reprogrammable computer and the pattern can be duplicated into the fabric through commands from the computer which guides a remote control apparatus which causes the frame quilting table to be moved relative to the sewing needle. If it is desired to change the pattern, the reprogrammable computer need only be reprogrammed to change the movement pattern of the table in the X-direction, Y-direction, and combination X-Y direction without having to also reprogram the sewing machine commands. If it is desired to change the sewing machine function, only the sewing machine function needs to be reprogrammed without having to also reprogram the frame table movement.
It is a further object of the present invention to provide an apparatus which can accommodate computerized pattern quilting of a predetermined computer generated pattern and also accommodate specialized hand selected patterns, or any combination thereof, in the same unit.
It is an additional object of the present invention to increase the rate of production of hand guided patterns sewn into large fabrics such as bedspread or quilts.
It is also an object of the present invention to provide a system for automatically duplicating the individualized patterns through a specialized computer aided design program or scanner, to thereby eliminate the necessity of using a digitizer/cursor board to individually record numerous plotted points of the pattern drawing and thereafter burn them into a E-Prom.
It is a further object of the present invention to provide a system wherein the computers which control the sewing machine function and the quilting table movement are segregated to thereby reduce the effort involved in reprogramming the computers.
Defined very broadly, the present invention is a method of repetitively sewing a pattern into a fabric having a large surface comprising: (a) positioning a sewing machine head having a source of thread and a sewing needle relative to said fabric; (b) retaining said fabric on a movable structure which can be made to move in a horizontal direction relative to the sewing needle and which can cause a portion of the surface of the fabric to be reached by the sewing needle so that thread can be sewn into the fabric; (c) causing said movable structure to move relative to the sewing machine through commands from a first process controller; and (d) causing said sewing machine head to perform stitching or alternative sewing machine functions from commands through a second process controller.
The present invention can also be defined as an apparatus for sewing thread into fabric, comprising: (a) a first structure supporting a sewing machine head having a sewing needle and a source of thread; (b) a second structure supporting the fabric in a position relative to said sewing needle so that thread may be sewn into the fabric; (c) said second structure capable of horizontal movement in the X-direction, the Y-direction, or any combination X-Y direction relative to said sewing needle; (d) means for generating the horizontal movement of said second structure in the X-direction, the Y-direction, or any combination X-Y direction; (e) a first process controller having an Input/Output board which is connected to said means for generating horizontal movement of said second structure and which processes commands for controlling movement of said second structure in the horizontal direction; (f) a second process controller connected to said sewing machine and which processes commands for controlling the sewing function of the sewing machine head, the second process controller also connected to said Input/Output board of said first process controller; and (g) said first process controller and said second process controller capable of being independently programmed so that programs and modifications to programs in one of the process controllers can be made independently of the other process controller.
Further novel features and other objects of the present invention will become apparent from the following detailed description, discussion and the appended claims, taken in conjunction with the drawings.
DRAWING SUMMARY
Referring particularly to the drawings for the purpose of illustration only and not limitation, there is illustrated:
FIG. 1 is a perspective view a frame quilting machine, including a process controller with computer aided design program and a sewing machine with a separate computer.
FIG. 2 is a block diagram of the components of the electronic control components of the present invention automatic quilting machine including pattern duplication through a reprogrammable computer or process controller which comprises a computer aided design computer program for controlling frame table movement and a sewing machine with a separate computer or process controller.
FIG. 3 is a top plan view of the main body of a frame quilting machine which includes the present invention of a separate process controller to control the table movement and a separate process controller to control sewing machine operation.
FIG. 4 is a front elevational view of a frame quilting machine which includes the present invention of a separate process controller to control the table movement and a separate process controller to control sewing machine operation.
FIG. 5 is an enlarged perspective view of the front portion of the main support bean of the frame quilting machine.
FIG. 6 is an enlarged perspective view of the rear portion of the main support beam of the frame quilting machine and attachments thereto.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Although specific embodiments of the invention will now be described with reference to the drawings, it should be understood that such embodiments are by way of example only and merely illustrative of but a small number of the many possible specific embodiments which can represent application of the principles of the invention. Various changes and modifications obvious to one skilled in the art to which the invention pertains are deemed to be within the spirit, scope and contemplation of the invention as further defined in the appended claims.
Referring to FIG. 1, the main structural elements of the automatic frame quilting machine for specialized quilting of patterns including pattern duplication through a reprogrammable computer which may comprise a computer aided design computer program (hereinafter referred to as "automatic quilting machine") will be discussed first. The entire automatic quilting machine is designated as 10. The main structural member of the automatic quilting machine 10 is a pair of posts or box members, comprising a left box member 12 and a right box member 14. By way of example, the left box member 12 which serves only as a support member can be made of quarter inch plate steel and can have a base which is twenty inches wide by twenty-four inches deep and fifty-two inches tall. The right box member 14 which includes the electronics and motors, as will be described later, in addition to acting as a support member, can also be made of quarter inch plate steel and can have a base which is forty-four inches wide by twenty-four inches deep and fifty-two inches tall. The two support boxes 12 and 14 support a pair of cross beams; an upper cross beam 16 and a lower cross beam 18. Upper cross beam 16 can be made of quarter inch plate steel and can be twenty-four feet long, four inches wide and eight inches tall. Lower cross beam 18 can be made of quarter inch plate steel and can be twenty-four feet long, eight inches wide and eight inches tall. As illustrated in FIG. 1, the two beams 16 and 18 run parallel to each other between support box members 12 and 14, and are separated by a gap "H" which by way of example may be nine and a half inches. The cross beams 16 and 18 are permanently attached to the supporting box members 12 and 14 by conventional means such as welding.
Referring to FIGS. 1 and 3, on the ground between the supporting box members 12 and 14 and beneath the lowermost cross beam 18 is the base track 20. The base track 20 is comprised of track supports 22 and 24 which support thereon a gear and rack system which will be described in greater later on. Track support 22 further comprises a track 23 on which a pair of rollers may roll. Track support 24 further comprises a track 25 on which a pair of rollers may roll. The track supports 22 and 24 are aligned parallel to each other and are attached by means of transverse spacing members 26 and 28 which also run parallel to each other, thereby forming a generally square base which rests on the ground. Resting immediately above the base track 20 is a first movable support member track 30. The first movable support member track 30 is comprised of a pair of parallel X-direction beams 32 and 34 and a pair of Y-direction beams 36 and 38 which are connected together to form a generally rectangular frame. The frame comprised of members 32, 34, 36 and 38 of first movable support members 30 supports transverse roller member 40 and 42. Transverse roller member 40 is supported between Y direction beams 36 and 38 and is generally parallel to X-direction beams 32 and 34 and is aligned directly over track support 22. Transverse roller member 40 further comprises a pair of rollers 39 and 41. Transverse roller member 42 is supported between Y-direction beams 36 and 38 and is generally parallel to X-direction beams 32 and 34 and is aligned directly over track support 24. Transverse roller member 42 further comprises a pair of rollers (not shown). First movable support track 30 can move in the X direction as the rollers on transverse roller members 40 and 42 can roll on the track 23 contained on track support 22 and on track 25 contained on track support 24 respectively. Y-direction beam 36 further comprises a track 35 and Y-direction beam 38 further comprises a track 37. Y-direction beams 36 and 38 further comprise gear and rack assemblies, as will be described later.
Resting immediately above the first movable support member track 30 is a second movable support member track 50. The second movable support member track 50 is comprised of a pair of parallel X-direction beams, one of which is shown at 52 and a pair of Y direction beams, one of which is shown at 58, which are connected together to form a generally rectangular frame. The Y-direction beams on the second movable support member track 50 each further comprise a pair of rollers which enable the second movable support track 50 to move in the Y-direction. Y-direction beam 58 comprises a pair of rollers 59 and 61 which move on track 37 and Y-direction beam 56 comprises a pair of rollers (not shown) which move on track 35.
Second movable track member 50 further comprises four posts at its corners, two of which, 60 and 62 are shown in FIG. 1. The four posts support quilt table 70 which is comprised of X-direction table beams 72 and 74 and Y-direction table beams 76 and 78, connected together by means such as welding. X-direction table beam 72 is supported on posts 60 and 62 and X direction table beam 74 is supported on the two opposite posts (not shown). Y-direction table beams 76 and 78 are supported on the two X-direction table beams 72 and 74 adjacent their respective ends, as shown in FIGS. 1 and 3. The two X-direction table beams 72 and 74 are parallel to each other and the two Y-direction table beams 76 and 78 are parallel to each other.
As illustrated in FIGS. 1 and 3, the posts on second movable track member 50 support the table beams such that the table beams 76 and 78 pass through gap H between cross beams 16 and 18 and table beams 72 and 74 can pass through the gap H if the Y direction movement is of sufficient length. In operation, a bedspread or quilt 100 is stretched across the table beams 72, 74, 76, and 78, which by way of example can form a table surface of approximately twelve feet in the X-direction by twelve and a half feet in the Y-direction, such that the quilt 100 is supported at its edges by the four table beams 72, 74, 76 and 78 which result in a fully accessible quilt over its entire interior upper and lower surface. The table beams are caused to move in the X-direction by first movable support track 30 as the rollers on transverse roller members 40 and 42 move along tracks 23 and 25 respectively. The length "L" of gap "H" is preferably at least twice the length of the two X-direction table beams 72 and 74. In this way, the entire X-direction area of the quilt table 70 can be reached by the centermost position along the cross beams 16 and 18. The table beams are caused to move in the Y direction by second movable support member track 50 when the rollers on its Y-direction beams move along tracks 35 and 37. The length of tracks 35 and 37 is at least twice the length of the two Y-direction table beams 76 and 78. In this way, the entire Y-direction area of the quilt table 70 can be reached by the centermost position along the cross beams 16 and 18. Through this combination of X and Y movements, the entire area of the quilt table 70 and the quilt 100 spread thereon can be reached by the centermost position of cross beams 16 and 18. In the preferred starting position, the quilt table 70 is centered relative to the cross beams 16 and 18 and can move in any X-Y direction relative the the centermost position of the cross beams.
The quilt table 70 can be caused to move in the X and Y directions as previously described by numerous conventional types of means, such as a gear and rack assembly. One such gear and rack assembly is illustrated in FIG. 4. Track support 22 supports track 23 on which rollers 39 and 41 can roll in the X-direction. Track support 22 further contains on its interior surface a rack assembly 80 having a conventional multiplicity of teeth which can accommodate a gear. Transverse roller member 40 further supports a rotatable gear 82 which is caused to rotate by a conventional gear drive mechanism 84 having smaller gears driven by a belt to drive the rotatable gear 82. The gear drive mechanism is driven by a conventional linkage hookup to a drive motor which causes a motor shaft to rotate and thereby drive the gear drive mechanism 84 which in turn causes the rotatable gear 82 to rotate. When the rotatable gear rotates in the clockwise direction, the rotatable gear moves along the rack assembly 80 and causes the transverse roller member 40 (and opposite transverse roller member 42) to move to the right in the X-direction. When the rotatable gear rotates in the counterclockwise direction, the rotatable gear moves along the rack assembly 80 and causes the transverse roller member 40 (and opposite transverse roller member 42) to move to the left in the X-direction. It will be appreciated that a comparable rack and gear assembly is supported on Y-direction beam 38 and Y-direction beam 58, thereby enabling Y-direction beams 58 (and the opposite Y-direction beam on second movable support member track 50) to move back and forth in the Y-direction.
It will be appreciated that conventional adjustment modifications can be incorporated into this system. For example the overall height of the quilt table 70 can be adjusted up and down by creating slidable adjustments in the the posts (60, 62 and to two opposite posts) in order to adjust the height of quilting table 70 relative to the cross beams 16 and 18.
Referring to FIGS. 4, 5, and 6, a sewing machine head 110 is bolted stationary to upper cross beam 16. To achieve the goal of the present invention in segregating the computer controlling the sewing functions from the computer controlling the quilting table movement, it is required that a sewing machine head having its own computer 120 be used. As illustrated in the block diagram of FIG. 2 and also in FIG. 6, the sewing machine 110 has attached to it a separate process controller or computer 120 which received input from the process controller of the frame quilting machine and thereafter feeds the commands to the sewing machine 110. This will be discussed in greater detail later on. By way of example, one type of sewing machine head which can be used with the present invention is the Mitsubishi Industrial Sewing Machine Model LS2-180 high speed, single needle lockstitch sewing machine. A microprocessor connected to this type of sewing machine head provides many auxiliary functions such as control of needle position, presser foot lift, undertrim, and tension release disk. The sewing machine head 110 is attached to the underside of upper cross beam 16 such that the sewing needle 112 is at the approximate center of cross-beam 16. In this manner, the sewing needle 112 can reach any portion of the quilt table 70 and quilt 100 thereon by the X-Y movement of the quilt table, as previously discussed. The sewing machine plate 114 is formed into the top of lower cross beam 18 such that the plate 114 is aligned with the needle 112, as best illustrated in FIG. 6.
A bobbin 124 is supported by a frame member 126 attached to one edge of upper cross beam 16. Thread 128 is wound on the bobbin 118 and is guided by conventional means through the sewing machine head 110 and to the needle 112.
While it would be possible to physically move the quilting table 70 as the needle is sewing the pattern, it is not practical since the table is heavy and could not be moved fast enough by hand to quickly guide the portion of quilt 100 to the area where the sewing needle 112 is sewing the next stitch. Therefore, an automatic electrical system for moving the quilting table 70 and quilt 100 thereon into position for appropriate sewing of the pattern is required. A block diagram of the electronics for performing this operation is presented in FIG. 2. A source of alternating current power 150 energizes the entire system. In one connection, the source of alternating current power 150 is connected to a monitor 140. In a second connection, the alternating current source is connected to an alternating current to direct current transformer 160. The transformer 160 is in turn connected to a process controller or computer 172 which provides control functions for movement of the quilting table beams in the X-direction, the Y-direction, and therefore the X-Y direction for subsequent duplication of the pattern as will be discussed hereafter. The AC to DC transformer 160 is also connected to a remote control apparatus such as a joystick or mouse 180 which in turn is connected to a control 170. The controller 170 has an X-axis input and a Y-axis input into the process controller or computer 172. The process controller 172 has an Input/Output (hereinafter "I/O") Board 177 which connects the process controller to an X-output and a Y-output. The X-output of the I/O Board 177 is connected to an X-axis controller 162 which in turn is connected to the X direction motor 164 which is a direct current motor. The I/O Board 177 of process controller 172 also has a Y-direction output which in turn is connected to a Y-axis controller 166 which in turn is connected to the Y direction motor 168 is which a direct current motor. In the block diagram of FIG. 2, the process controller 172 is also shown connected to an external memory 174. It is also within the spirit and scope of the present invention for the process controller to have an internal memory. Included within the process controller 172 is a graphics card 173 through which the process controller 172 is connected to the monitor 140. The process controller 172 may also be programmed through floppy disks or a hard disk with a computer aided design ("CAD") program 175.
Through use of the process controller 172, its graphics card 173 and the CRT monitor 140, a pattern may be drawn through use of the Joystick/Mouse 180 and drawn on the CRT Monitor 140. Thereafter the pattern is programmed into the process controller 172 through programming means such as a Computer Aided Design Program 175. The process controller 172 through the I/O Board 177 puts out RPM Commands through its X-output and Y-output to direct the X-axis controller 162 and Y-axis controller 166 to cause the X-axis motor 164 and Y-axis motor to run at certain RPM's and move the quilting table 70 is the desired pattern direction. The I/O Board 177 of the process controller 172 is also connected to the separate sewing machine controller 120. The process controller 172 through its I/O Board 177 sends out voltage commands to the sewing machine process controller 120. Typically, the voltage commands are from 0 to 10 volts. Upon receiving the voltage command, the sewing machine process controller converts them into RPM commands and directs the sewing machine 110 to perform either stitching functions or else to perform auxiliary functions such as trim, tension open disk, foot lift, etc. The critical element in the present invention concept is that the movement of frame quilting table 70 is controlled by one process controller 172 while the sewing machine 110 is controlled by its separate process controller 120. If it is desired to reprogram the pattern being sewn or to make a modification in the existing pattern, which therefore requires a program modification to change the commands which cause the frame quilting table 70 to move in a given set of directions relative to the sewing machine head 110, it is only necessary to reprogram the process controller 172 to change the movements of the frame quilting table 70. It is not necessary to also reprogram the stitching functions of the sewing machine process controller 120 or the sewing machine 110. Therefore, instead of having to reprogram all of the combinations of table movement and stitches to be made to correspond to the table movement which can take many hours and sometimes days to complete, it is only necessary to reprogram the table movement into the machine process controller 172 and thereafter this process controller 172 sends its voltage commands to the sewing machine process controller 120 which in turn commands the sewing machine 110 to perform either stitching functions or auxiliary functions. The CAD Program 175 is one of the types of computer programs which can be used with the present invention.
The frame quilting table 70 can be programmed to move in any desired direction and variable speeds so that high-speed and low-speed moves can be programmed from the process controller 172. By way of example, the high-speed may be set to a maximum diagonal speed of approximately twenty-five feet per minute. Limit switches may be included to prevent the table's overtravel. The DC motors 164 and 168 may be variable speed motors which are coupled to the quilt table through conventional drive belts, gears and racks, as previously described. The mechanical portion of the drive system can be suitable for adaptation to a computer controlled servo system and can therefore be controlled by the process controller 172. The electronic control components including the AC to DC transformer 160, the X-axis controller 162, the Y-axis controller 166, the X-direction motor 164, the Y-direction motor 168 and the controller 170 can all be housed in the larger supporting box member 14. In the illustration of FIG. 1, the process controller 172 is shown adjacent the monitor 140. It is also possible to house the process controller 172 and its external memory 174 within larger supporting box member 14. In the preferred embodiment, the sewing machine controller 120 is also housed within larger supporting box member 14 and connected to the sewing machine 110 through wires extending through the upper cross beam 16 and/or lower cross beam 18.
An improvement which may be used in conjunction with the present invention two computer or process controller system is a computer aided design system for creating the pattern which will be sewn by the frame quilting machine. The individual can select a pattern which is to be sewn into the machine. The pattern can be hand drawn onto the monitor 140 through use of a cursor moving apparatus such as a mouse 170. The cursor moving apparatus 180 can hand drawn the pattern onto the monitor 140 and the individual can make any number of modifications and selections so that a hand designed pattern can be completely drawn on the monitor 140. After the hand drawn pattern has been drawn onto the monitor 140, the operator feeds the drawing data into the computer aided design program 175 which automatically converts the drawn graphic image into machine readable form. In the event modifications are required, the graphic pattern can be called up on the monitor 140 and the required changes made by movement of the cursor through the mouse 170 until the modified pattern has been achieved. Then the pattern is once again fed through the computer aided design program 175 and converted into machine readable form. In addition, the operator can select a grid on the monitor 140 and program a point from the graphic pattern at each location on the grid where the pattern is to be duplicated. This information can also be fed into the computer aided design program and stored. Therefore, the process controller can automatically direct the frame quilting table to move in the desired X, Y, or X-Y direction to automatically sew the programmed pattern into the fabric 100 and to cause the pattern to be duplicated on the points as marked on the computer monitor grid. Commands are fed from the I/O Board 177 of the process controller 172 through the X-axis output to the X-axis controller 162 to the X motor 164, and from the I/O Board 177 of the process controller 172 through the Y-axis output to the Y-axis controller 166 to the Y motor 168. Therefore, the present invention of two separate computers used in frame quilting can be combined with a computer aided design program (which by way of example can be an AutoSketch-R or an AutoCad-R program) so that individualized patterns can be hand drawn on the computer monitor and automatically converted into machine readable language from which the process controller can automatically sew the pattern into the fabric (such as a quilt or bedspread) and further duplicate the pattern at any multiplicity of desired locations.
By way of example the computer aided design program 175 can be the AutoSketch-R program. The AutoSketch R program is a full-function computer-aided design package for generating line art. The drawing is created using a mouse and menus which have therein various shapes such as lines, arcs, circles, points, polygons and spline curves (spline curves are curves fitted to a frame of control points which have been specified). After the drawing has been made, the drawing can be duplicated at any desired location and in any manner. The drawings can be enlarged to add fine points or otherwise modified to suit the final desired pattern.
The key design element of the present system is that the process controller 172 which controls the X-Y movement of the quilting table and the trace pattern which is stored in the computer's memory as a computer aided design pattern is separate from the computer on the sewing head 110 which controls the sewing needle stitch and speeds. This is accomplished by using a sewing head which has its own independent computer such as a Mitsubishi Industrial Sewing Machine Model LS2-180 high speed, single needle lockstitch sewing machine. In this way, if it is necessary to add new stitch patterns into memory, it is a much simpler task to add the new stitch and program commands to the process controller 172 without also having to reprogram the stitching and other needle functions on the sewing machine head.
Because of the independent computer capability of the machine with one computer controller the X-Y movement and a second computer on the sewing machine controlling the sewing and stitching functions, the operator can trace a straight line pattern into the X-Y process controller 172 and a software program command to the X-Y process controller 172 will enable the pattern to be automatically modified into a zig-zag or any other desired pattern. This is a valuable modification which cannot be easily achieved with prior art systems where the computer for the sewing machine and X-Y movement is integrated into one large computer. The software program for such prior art systems is too complicated. In such prior art systems, each stitch and each movement for each stitch would need to be programmed. In the prior art you have for example 5 stitches per inch and 4,000 linear inches per fabric so 20,000 stitches and movements per stitch must be programmed. With the present invention, only the table movement needs to be programmed because the stitch pattern is a separate independent program controlled by a separate computer on the sewing machine.
Of course the present invention is not intended to be restricted to any particular form or arrangement, or any specific embodiment disclosed herein, or any specific use, since the same may be modified in various particulars or relations without departing from the spirit or scope of the claimed invention hereinabove shown and described of which the apparatus is intended only for illustration and for disclosure of an operative embodiment and not to show all of the various forms or modification in which the invention might be embodied or operated.
The invention has been described in considerable detail in order to comply with the patent laws by providing full public disclosure of at least one of its forms. However, such detailed description is not intended in any way to limit the broad features or principles of the invention, or the scope of patent monopoly to be granted. | An automatic quilting machine for use in stitching individual selected patterns into a large fabric such as a bedspread or quilt. The bedspread or quilt is stretched on a large metal frame which is mounted on a table which can be moved in the X-direction, the Y-direction, or any X-Y combination direction, either through a manually operated automatic joystick or mouse or through an automatic remote control directed by a computer. The sewing machine function is controlled by one computer connected to the sewing machine head and the quilting table motion in the X-direction, Y-direction, and X-Y direction is controlled by a separate computer. When it is desired to change a sewing machine computer function such as a stitch or accessory functions such as trim, the sewing machine computer can be independently reprogrammed. When it is desired to change the pattern, the separate computer controlling the X-Y table movement direction can be independently reprogrammed. It is not necessary to reprogram both funcions which is an enormous task. Instead, only one of the functions needs to be reprogrammed, thereby greatly simplifying the process. | big_patent |
TECHNICAL FIELD
[0001] The present invention relates generally to methods of making nonwoven fabrics, and more particularly, to a method of manufacturing a two-sided nonwoven fabric exhibiting a three-dimensional image, permitting use of the fabric in a wide variety of consumer applications.
BACKGROUND OF THE INVENTION
[0002] The production of conventional textile fabrics is known to be a complex, multi-step process. The production of fabrics from staple fibers begins with the carding process whereby the fibers are opened and aligned into a feedstock referred to in the art as “sliver”. Several strands of sliver are then drawn multiple times on a drawing frames to further align the fibers, blend, improve uniformity and reduce the sliver's diameter. The drawn sliver is then fed into a roving frame to produce roving by further reducing its diameter as well as imparting a slight false twist. The roving is then fed into the spinning frame where it is spun into yarn. The yarns are next placed onto a winder where they are transferred into larger packages. The yarn is then ready to be used to create a fabric.
[0003] For a woven fabric, the yarns are designated for specific use as warp or fill yarns. The fill yarns (which run on the y-axis and are known as picks) are taken straight to the loom for weaving. The warp yarns (which run on the x-axis and are known as ends) must be further processed. The large packages of yarns are placed onto a warper frame and are wound onto a section beam were they are aligned parallel to each other. The section beam is then fed into a slasher where a size is applied to the yarns to make them stiffer and more abrasion resistant, which is required to withstand the weaving process. The yarns are wound onto a loom beam as they exit the slasher, which is then mounted onto the back of the loom. The warp yarns are threaded through the needles of the loom, which raises and lowers the individual yarns as the filling yarns are interested perpendicular in an interlacing pattern thus weaving the yarns into a fabric. Once the fabric has been woven, it is necessary for it to go through a scouring process to remove the size from the warp yarns before it can be dyed or finished. Currently, commercial high-speed looms operate at a speed of 1000 to 1500 picks per minute, where a pick is the insertion of the filling yarn across the entire width of the fabric. Sheeting and bedding fabrics are typically counts of 80×80 to 200×200, being the ends per inch and picks per inch, respectively. The speed of weaving is determined by how quickly the filling yarns are interlaced into the warp yarns, therefore looms creating bedding fabrics are generally capable of production speeds of 5 inches to 18.75 inches per minute.
[0004] In contrast, the production of nonwoven fabrics from staple fibers is known to be more efficient than traditional textile processes, as the fabrics are produced directly from the carding process.
[0005] Nonwoven fabrics are suitable for use in a wide variety of applications where the efficiency with which the fabrics can be manufactured provides a significant economic advantage for these fabrics versus traditional textiles. However, nonwoven fabrics have commonly been disadvantaged when fabric properties are compared to conventional textiles, particularly in terms of resistance to elongation, in applications where both transverse and co-linear stresses are encountered. Hydroentangled fabrics have been developed with improved properties, by the formation of complex composite structures in order to provide a necessary level of fabric integrity. Subsequent to entanglement, fabric durability has been further enhanced by the application of binder compositions and/or by thermal stabilization of the entangled fibrous matrix.
[0006] Nonwoven composite structures typically improve physical properties, such as elongation, by way of incorporation of a support layer or scrim. The support layer material can comprise an array of polymers, such as polyolefins, polyesters, polyurethanes, polyamides, and combinations thereof, and take the form of a film, fibrous sheeting, or grid-like meshes. Metal screens, fiberglass, and vegetable fibers are also utilized as support layers. The support layer is commonly incorporated either by mechanical or chemical means to provide reinforcement to the composite fabric. Reinforcement layers, also referred to as a “scrim” material, are described in detail in U.S. Pat. No. 4,636,419, which is hereby incorporated by reference. The use of scrim material, more particularly, a spunbond scrim material is known to those skilled in the art.
[0007] Spunbond material comprises continuous filaments typically formed by extrusion of thermoplastic resins through a spinneret assembly, creating a plurality of continuous thermoplastic filaments. The filaments are then quenched and drawn, and collected to form a nonwoven web. Spunbond materials have relatively high resistance to elongation and perform well as a reinforcing layer or scrim. U.S. Pat. No. 3,485,706 to Evans, et al., which is hereby incorporated by reference, discloses a continuous filament web with an initial random staple fiber batt mechanically attached via hydroentanglement, with a second random staple fiber batt then attached to the continuous filament web, again, by hydroentanglement. A continuous filament web is also utilized in U.S. Pat. Nos. 5,144,729; 5, No. 187,005; and No. 4,190,695. These patents include a continuous filament web for reinforcement purposes or to reduce elongation properties of the composite.
[0008] More recently, hydroentanglement techniques have been developed which impart images or patterns to the entangled fabric by effecting hydroentanglement on three-dimensional image transfer devices. Such three-dimensional image transfer devices are disclosed in U.S. Pat. No. 5,098,764, which is hereby incorporated by reference; with the use of such image transfer devices being desirable for providing a fabric with enhanced physical properties as well as an aesthetically pleasing appearance.
[0009] For specific applications, a two-sided, three-dimensionally imaged nonwoven fabric must exhibit a combination of specific physical characteristics. U.S. Pat. No. 5,302,446 discloses a two-sided nonwoven fabric, however the fabric is ultrasonically bonded and both sides of the fabric are treated with a surfactant so as to render it hydrophilic. The two-sided hydroentangled fabric of the present invention is comprised of at least three layers. The second layer acts as a fiber distribution control layer between the first and third layers wherein the fibrous matrix of the two outer layers may be of the same or different compositions. This construct specifically lends itself useful as a wipe. For example, when the fabric of the present invention is employed in the formation of cleansing wipes, the fabric construct can exhibit sufficient softness for intimate contact with the skin, but also can be capable of exfoliating the skin. Further, the two-sided, three-dimensionally imaged nonwoven fabric is reinforced with a support layer or scrim that is water pervious to ensure effective integration of the construct during hydroentanglement, but able deter the fibers from the first side and from second side of the fabric from becoming extensively intermingled in the production process and yet retain sufficient resistance to delamination.
[0010] Notwithstanding various attempts in the prior art to develop a three-dimensionally imaged nonwoven fabric acceptable for home, medical and hygiene applications, a need continues to exist for a nonwoven fabric which provides a pronounced image, as well as the requisite mechanical characteristics.
SUMMARY OF THE INVENTION
[0011] The present invention is directed to a method of forming a two-sided nonwoven fabric, which exhibits a pronounced three-dimensional image that is durable to both converting and end-use application. In particular, the present invention contemplates that a fabric is formed from a first precursor web comprising a first fibrous matrix and a second precursor web comprising a second fibrous matrix. Between the first and second precursor web, a fluid-pervious support layer or scrim, is interposed and subjected to hydroentanglement on a moveable imaging surface having a three-dimensional image transfer device. By formation of a nonwoven fabric in this fashion, a three-dimensional image that is durable to abrasion and distortion due to elongation is imparted and a product formed which exhibits on its opposite surfaces the unique properties of the respective fibrous matrix used.
[0012] In accordance with the present invention, a method of making a nonwoven fabric embodying the present invention includes the steps of providing a first precursor web comprising a fibrous matrix and a second precursor web comprising a second matrix. While use of staple length fibers is typical, the first and/or second fibrous matrices may comprise substantially continuous filaments. In a particularly preferred form, the first and second fibrous matrices comprise staple length fibers, which are carded and cross-lapped to form precursor webs. In one embodiment of the present invention, the precursor webs are subjected to pre-entangling on a foraminous-forming surface prior to juxtaposition of a support layer or scrim and subsequent three-dimensional imaging. Alternately, one or more layers of fibrous matrix are juxtaposed with one or more support layers or scrims, then the layered construct is pre-entangled to form a precursor web which is imaged directly, or subjected to further fiber, filament, support layers, or scrim layers prior to imaging.
[0013] In a first embodiment, the fabric has a first side or surface comprised of a first fibrous matrix and a second side or surface comprised of a second fibrous matrix, wherein said first and second fibrous matrix are dissimilar. Further, the first and second sides are separated by an intermediate water pervious, fiber distribution control layer, which acts to deter the excessive intermingling of the first fibrous matrix and second fibrous matrix.
[0014] In a second embodiment, the fabric further includes apertures wherein the apertures may extend partially or entirely through one or more of the component layers.
[0015] In a third embodiment, the fibrous constituent of the first fibrous matrix and the second fibrous matrix exhibit a by fiber modulus difference of at least 10%, wherein the fibrous matrix with the lower fiber modulus comes in contact with the three-dimensional imaging transfer device. For example, if the first side is comprised of a first fibrous matrix comprising a 1.2 dpf fiber and the second side is comprised of a second fibrous matrix comprising a 15 dpf fiber, then the first side would become the side that comes in contact with the three-dimensional imaging transfer device.
[0016] The first and second precursor webs, with an interposed fiber distribution control layer, are advanced onto the imaging surface of the image transfer device. Hydroentanglement of the precursor web is affected to form a three-dimensionally imaged fabric. Significantly, the incorporation of a fiber distribution control layer acts to limit the ability of the fibrous constituent of the first precursor web and the second precursor web from becoming extensively intermixed, and yet results in a nonwoven fabric that exhibits sufficient resistance to delamination.
[0017] Subsequent to hydroentanglement, the three-dimensionally imaged fabric may be subjected to one or more variety of post-entanglement treatments. Such treatments may include application of a polymeric binder composition, mechanical compacting, application of surfactant or electrostatic compositions, and like processes.
[0018] In the preferred form, the precursor webs are hydroentangled on a foraminous surface prior to hydroentangling on the image transfer device. This pre-entangling of the precursor web acts to integrate the fibrous components of the web, but does not impart a three-dimensional image as can be achieved through the use of the three-dimensional image transfer device.
[0019] Optionally, subsequent to three-dimensional imaging, the imaged nonwoven fabric can be treated with a performance or aesthetic modifying composition to further alter the fabric structure or to meet end-use article requirements. A polymeric binder composition can be selected to enhance durability characteristics of the fabric, while maintaining the desired softness and drapeability of the three-dimensionally imaged fabric. A surfactant can be applied so as to impart hydrophilic properties. In addition, electrostatic modifying compound can be used to aid in cleaning or dusting applications.
[0020] Other features and advantages of the present invention will become readily apparent from the following detailed description, the accompanying drawings, and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] [0021]FIG. 1 is a diagrammatic view of an apparatus for manufacturing a durable nonwoven fabric, embodying the principles of the present invention.
DETAILED DESCRIPTION
[0022] While the present invention is susceptible of embodiment in various forms, there is shown in the drawings, and will hereinafter be described, a presently preferred embodiment of the invention, with the understanding that the present disclosure is to be considered as an exemplification of the invention, and is not intended to limit the invention to the specific embodiment illustrated.
[0023] The present invention is directed to a method of forming two-sided nonwoven fabrics by hydroentanglement, wherein three-dimensional imaging of the fabrics is enhanced and a fiber distribution control layer put into place between the two sides by the incorporation of at least one fluid-pervious support layer or scrim. Enhanced imaging can be achieved utilizing various techniques, one such technique involves minimizing and eliminating tension in the overall precursor web as the web is advanced onto a moveable imaging surface of the image transfer device, as represented by co-pending U.S. patent application Serial No. 60/344,259, to Putnam et al, entitled Nonwoven Fabrics Having a Durable Three-Dimensional Image, and filed on Dec. 28, 2001, which is hereby incorporated by reference. The use of a support layer or scrim benefits the fabric of the present invention providing a median fiber distribution control layer wherein the support layer deters the fibrous constituents of the two outer layers from becoming excessively intermingled with one another. The incorporation of a support layer improves the overall performance of the two-sided fabric by providing a three-dimensionally imaged nonwoven fabric that exhibits a pronounced difference in surface performance properties inherent to the fibrous matrix used.
[0024] A method of making the present two-sided, three-dimensionally imaged nonwoven fabric comprises the steps of providing at least a first precursor web comprised of a first fibrous matrix and a second precursor web comprising a second fibrous matrix and a median support layer or scrim to act as the fiber distribution control layer, which is subjected to hydroentangling. The precursor webs are formed into a three-dimensionally imaged nonwoven fabric by hydroentanglement on a three-dimensional image transfer device. The image transfer device defines three-dimensional elements against the precursor web whereby the first fibrous matrix is displaced into the three-dimensional topography while the second fibrous matrix is significantly retained on the side away from the three-dimensional topography forced during hydroentanglement.
[0025] With reference to FIG. 1, therein is illustrated an apparatus for practicing the present method for forming a nonwoven fabric. The fabric is formed from a fibrous matrix, which typically comprises staple length fibers, but may comprise substantially continuous filaments. The fibrous matrix is preferably carded and cross-lapped to form a fibrous batt, designated F. In a current embodiment, the fibrous batt comprises 100% cross-lap fibers, that is, all of the fibers of the web have been formed by cross-lapping a carded web so that the fibers are oriented at an angle relative to the machine direction of the resultant web. U.S. Pat. No. 5,475,903, hereby incorporated by reference, illustrates a web drafting apparatus.
[0026] A support layer or scrim is then placed in face to face to face juxtaposition with a first fibrous web and hydroentangled to form precursor web P. Alternately, the fibrous web can be hydroentangled first to form precursor web P, and subsequently, at least one support layer or scrim is applied to the precursor web, and the composite construct optionally further entangled with non-imaging hydraulic manifolds, then imparted with a three-dimensional image on an image transfer device.
[0027] [0027]FIG. 1 illustrates a hydroentangling apparatus for forming nonwoven fabrics in accordance with the present invention. The apparatus includes a foraminous-forming surface in the form of belt 10 upon which the precursor web P is positioned for pre-entangling by entangling manifold 12 . Pre-entangling of the precursor web, prior to three-dimensional imaging, is subsequently effected by movement of the web P sequentially over a drum 14 having a foraminous-forming surface, with entangling manifold 16 effecting entanglement of the web. Further entanglement of the web is effected on the foraminous forming surface of a drum 18 by entanglement manifold 20 , with the web subsequently passed over successive foraminous drums 20 , for successive entangling treatment by entangling manifolds 24 ′, 24 ′.
[0028] The entangling apparatus of FIG. 1 further includes a three-dimensional imaging transfer device 24 comprising a three-dimensional image transfer device for effecting imaging of the now-entangled precursor web. The image transfer device includes a moveable imaging surface which moves relative to a plurality of entangling manifolds 26 which act in cooperation with three-dimensional elements defined by the imaging surface of the image transfer device to effect imaging and patterning of the fabric being formed.
[0029] The present invention contemplates that the fluid-pervious support layer or scrim be any such suitable material, including, but not limited to, wovens, knits, open mesh scrims, and/or nonwoven fabrics, which exhibit low elongation performance. Two particular nonwoven fabrics of particular benefit are spunbond fabrics, as represented by U.S. Pat. No. 3,338,992, No. 3,341,394. No. 3,276,944, No. 3,502,538, No. 3,502,763, No. 3,509,009; No. 3,542,615; and Canadian Patent No. 803,714, these patents are incorporated by reference, and nanofiber fabrics as represented by U.S. Pat. No. 5,678,379 and No. 6,114,017, both incorporated herein by reference. A particularly preferred embodiment of support layer or scrim is a thermoplastic spunbond nonwoven fabric. The support layer may be maintained in a wound roll form, which is then continuously fed into the formation of the precursor web, and/or supplied by a direct spinning beam located in advance of the three-dimensional imaging drum 24 .
[0030] Manufacture of a durable nonwoven fabric embodying the principles of the present invention is initiated by providing the fibrous matrix, which can include the use of staple length fibers, continuous filaments, and the blends of fibers and/or filaments having the same or different composition. Fibers and/or filaments are selected from natural or synthetic composition, of homogeneous or mixed fiber length. Suitable natural fibers include, but are not limited to, cotton, wood pulp and viscose rayon. Synthetic fibers, which may be blended in whole or part, include thermoplastic and thermoset polymers. Thermoplastic polymers suitable for blending with dispersant thermoplastic resins include polyolefins, polyamides and polyesters. The thermoplastic polymers may be further selected from homopolymers; copolymers, conjugates and other derivatives including those thermoplastic polymers having incorporated melt additives or surface-active agents. Staple lengths are selected in the range of 0.25 inch to 10 inches, the range of 1 to 3 inches being preferred and the fiber denier selected in the range of 1 to 22, the range of 2.0 to 20 denier being preferred for general applications. The profile of the fiber and/or filament is not a limitation to the applicability of the present invention.
[0031] Using a forming apparatus as illustrated in FIG. 1, a nonwoven fabric was made in accordance with the present invention by providing a layered precursor web comprised of differing fiber compositions. In a preferred embodiment, a layered precursor web comprising a first side comprising layers including a first fibrous matrix blend of 85%, 1.2 dpf polyester, made commercially available as Wellman Type 472, and 15%, 2.0 dpf low melt bicomponent fiber, commercially available as Stein Type 131-00251S, and a second layer blend of 90%, 1.2 dpf polyester fiber and 10% rayon fiber, made commercially available as Lenzing 8192. The precursor web included a median layer of 0.50 os/y 2 of polypropylene spunbond, and a second side comprising a second fibrous matrix blend of 50%, 3 dpf polyester and 50% 15 dpf polyester. The first side, comprised of the first fibrous matrix comprising 1.2 dpf fibers was placed in contact with the three-dimensional imaging transfer device. The image transfer device defines three-dimensional elements against the precursor web whereby the first fibrous matrix is displaced into the three-dimensional topography while the second fibrous matrix is significantly retained on the side away from the three-dimensional topography forced during hydroentanglement. Such a construct, allows for a soft side comprised of fine denier fibers wherein upon imaging, the fine fibers perform so as to provide a pronounced imaged. The spunbond layer incorporated therein acts to separate the aforementioned three-dimensionally imaged side from the courser side, which is comprised of a larger fiber.
[0032] Optionally, the fabric of the present invention may comprise apertures. The apertures may be of various shapes and sizes while spaces equal distances from one another or randomly distributed throughout the resultant fabric. Further, the apertures may extend through one or more layers of the fabric.
[0033] The material of the present invention may be utilized in the construction of a numerous home cleaning, personal hygiene, medical, and other end use products where a three-dimensionally imaged nonwoven fabric can be employed. Disposable absorbent hygiene articles, such as a sanitary napkins, incontinence pads, diapers, and the like, wherein the term “diaper” refers to an absorbent article generally worn by infants and incontinent persons that is worn about the lower torso of the wearer can benefit from the improved resiliency of the imaged nonwoven in the absorbent layer construction. An imaged nonwoven fabric may also be utilized as a landing zone affixed to the disposable absorbent article whereby the distal end of a fastening strip may attach; the imaged nonwoven fabric exhibiting improved “loop” durability and fuzz resistance to repeated, or finite, “hook” attachment cycles. In addition, the material may be utilized as medical gauze, or similar absorbent surgical materials, for absorbing wound exudates and assisting in the removal of seepage from surgical sites. Other end uses include; fabrication into wet or dry facial or hard surface wipes, which can be readily hand-held for cleaning and the like, protective wear for medical and industrial uses, such as gowns, shirts, bottom weights, lab coats, face masks, and the like, and protective covers, including covers for vehicles such as cars, trucks, boats, airplanes, motorcycles, bicycles, golf carts, as well as covers for equipment often left outdoors like grills, yard and garden equipment, such as mowers and roto-tillers, lawn furniture, floor coverings, table cloths and picnic area covers. The material may also be used in apparel construction, such as for bottom weights of every day wear, which includes pants and shorts.
[0034] From the foregoing, it will be observed that numerous modifications and variations can be affected without departing from the true spirit and scope of the novel concept of the present invention. It is to be understood that no limitation with respect to the specific embodiments illustrated herein is intended or should be inferred. The disclosure is intended to cover, by the appended claims, all such modifications as fall within the scope of the claims. | The present invention is directed to a method of forming a two-sided nonwoven fabric, which exhibits a pronounced three-dimensional image that is durable to both converting and end-use application. In particular, the present invention contemplates that a fabric is formed from a first precursor web comprising a first fibrous matrix and a second precursor web comprising a second fibrous matrix. Between the first and second precursor web, a fluid-pervious support layer or scrim, is interposed and subjected to hydroentanglement on a moveable imaging surface having a three-dimensional image transfer device. By formation of a nonwoven fabric in this fashion, a three-dimensional image that is durable to abrasion and distortion due to elongation is imparted and a product formed which exhibits on its opposite surfaces the unique properties of the respective fibrous matrix used. | big_patent |
FIELD AND BACKGROUND OF THE INVENTION
This invention relates in general to sewing machines and in particular to a new and useful device for feeding a strip of material into a sewing machine and sewing it into a cut of fabric.
A device similar to the present invention is disclosed in German No. OS 24 48 887. The device is used in the manufacture of trimmed pockets, for simultaneously sewing in a strip of fabric, the so-called flap. To insert the strip of fabric in a position to start the sewing operation exactly at the edge of the strip, the needle stuck into the fabric is used as a stop for the strip. For this purpose, the needle must be brought, after putting the cut of fabric in place and prior to inserting the strip, from its upper position outside the fabric into its stuck-in low position. To eliminate the necessity of a manual intervention, a photocell unit is provided in the needle zone as a means for controlling the switching function of the sewing machine, which cooperates with a reflective surface of an apparatus for guiding the strip of fabric. Upon inserting the strip of fabric into the guide apparatus, the photocell unit responds to actuate a positioner of the sewing machine and move the needle from its upper into its lower position.
The leading edge of the strip of fabric can be displaced to the stop formed by the needle only upon starting the machine to bring the needle into the low position, and stopping it again. This affects a continuous operation.
With soft strips of fabric, the use of the needle as a stop does not show any disadvantage. It become prohibitive however, as soon as relatively stiff strips are involved, such as strips of paperboard, cardboard, plastic or leather, which are employed in the manufacture of automobile seat slipcovers, for example, since then there is a great chance of deforming the needle. Further sewing with a deformed needle not only can easily lead to erroneous stitches causing time losses in changing the needle, threading again, a mending of the seams, but even the rotary hook may get damaged. Further, the needle stuck in the fabric cannot be used as a stop if the seam is to be started with some backstitches under reversed feed, as is required in most instances, since then the stop must be displaced to some extent beneath and beyond the needle in the forward feed direction.
SUMMARY OF THE INVENTION
The invention is directed to a device ensuring a continuous operation, making it possible to sew relatively stiff strips of material, and being insensitive to disturbances.
Upon inserting the cut of fabric in the correct position, the leading edge of the strip of material, which is advanced to the stitch forming area, butts against the stop which has been brought into the feed path of the strip, and displaces it into an end position in which the stop is to be sewed onto the cut of fabric and in which a signal transmitter, such as a control switch of the sequence control for starting the retraction of the stop, the lowering of the presser foot, and the starting of the sewing machine are actuated, so that by a single feed motion the strip is brought into its predetermined end position and the switching processes necessary for starting the sewing operation are released.
In accordance with the invention, a device for feeding a strip of material into the sewing machine and sewing it onto a cut of fabric comprises control means which are actuable by a strip of material to control the switching functions of the sewing machine. The control means includes a stop which may be moved into the feed path of the strip and after being contacted by the strip can be retracted from the feed path. The movement of the stop controls a signal transmitter for a setting means for the stop. The stop is advantageously mounted on a two armed lever which is mounted for being moved and which is biased by a spring. A control cam is in the path of retraction of the stop and the lever can be moved into a position in which the signal transmitter is actuated independently of the strip. The stop is advantageously mounted for being displaced by a setting means in the form of an air cylinder and substantially perpendicularly to the feed motion of the workpiece. The limits of the setting motion of the stop can be adjusted by displaceable stops.
Accordingly, it is an object of the invention to provide a sewing machine which includes a guide chute for a strip of add on material which overlies the bed plate over which a workpiece material is fed. A stop is arranged in the feed path of the strip for contacting and stopping the feeding thereof which is displaceable out of the path and connectable by control means to the sewing machine for controlling the operation of the sewing machine in accordance with the position of the stop and the strip material.
A further object of the invention is to provide a sewing machine control for feeding strip materials to a workpiece which is simple in design, rugged in construction and economical to manufacture.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawing and descriptive matter in which a preferred embodiment of the invention is illustrated.
BRIEF DESCRIPTION OF THE DRAWING
The only FIGURE of the drawing is a perspective view showing a sewing machine with a bed plate over which material is fed into association with a strip of material constructed in accordance with the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawing, in particular the invention embodied therein comprises a sewing maching which includes a bed plate 1 having a slide 2 on which the workpiece or fabric W is positioned for feeding by feed means including a feed dog 4 into association with a needle 7 which reciprocates upwardly and downwardly. In accordance with the invention a guide apparatus 11 is provided for feeding a strip of material ST which has an opening adjacent the needle out of which the strip of material is fed into association with the workpiece W for sewing by the needle. In accordance with the invention a control setup is arranged which includes a stop in the feed path of the strip ST for contacting the feed path and preventing feed thereof when the strip is not fed in correct association with the fabric W and and it is carried by a doubled arm lever member 36 which is part of a control means including a control switch 41 and a setting means 30 for adjusting the position of the stop.
Of a sewing which is to be equipped with the inventive device, only a few parts are shown, namely the bed plate 1, the slide 2, the needle plate 3, and the legs 4 of a feed dog of the four-motion type, which protrude upwardly through slots 5 provided in needle plate 3, to move the workpiece through the stitch forming area. The thread guiding needle 7 moves downwardly through a needle hole 6, and cooperates with a rotary hook (not shown) to form a seam.
The inventive device comprises a mounting plate 8 which, in a manner known per se, is pivoted to bed plate 1 of the sewing machine. To guide the edge of the cut of fabric W, an arcuate web 9 and a guide edge 10 are provided on mounting plate 8. Upstream of the stitch forming area, a guide apparatus 11 is mounted for guiding a strip of material ST which is cut to a predetermined length and it is to be advanced by its leading edge 12 into a definite position, in the present example; into alignment with a notch 13 provided in cut W, and sewed into the cut W. Guide apparatus 11 is provided with a lateral flange 14 and is screwed to a plate 15 which is conformable to arcuate web 9 and slants toward the stitch forming area so as to leave sufficient space for cut W. Secured to one of the sidewalls of guide apparatus 11 is a supporting bracket 16 for a shaft 17 of a contact arm 18. Contact arm 18 extends through a slot 19 of guide apparatus 11 into the feed path of strip ST. Secured to shaft 17 is a switch arm 20 against which one leg 21 of a torsion spring 22 is applied having its other leg (not shown) bearing against bracket 16. Switch arm 20 operates on a proximity switch 23 which is supported by an angle 24 secured to mounting plate 8 and by which, through the sequence control known per se and comprising a selector switch, a solenoid valve 25 is controlled to start the operation for stopping the sewing machine as soon as strip ST loses contact with contact arm 18 shortly befor the end of the seam, and switch arm 20 moves away from proximity switch 23.
An angle 26 screwed to mounting plate 8 carries a supporting member 27 which is mounted for pivoting about a stud 28 and is secured against axial displacement by a locking washer 29. To one of the ends of supporting member 27, an air cylinder 30 is secured by means of an angle bracket 31 screwed to supporting member 27. To permit adjustment of air cylinder 30, the screws 32 securing angle bracket 31 are passed through an oblong slot 33. A piston rod 34 of air cylinder 30 has a square cross section, to secure it against rotation. To the free end of the piston rod 34, a holder 35 is secured on which a two-armed lever 36 is mounted for pivoting about a pin 37 of the holder 35, and secured by a locking washer 38 against axial displacement. One end of lever 36 is angled downwardly and forms a stop 39 for the leading end 12 of strip ST, which stop can temporarily be moved into the feed path of strip ST. The other end of lever 26 serves as a switch arm 40 for a proximity switch 41 which is supported on holder 35 and by which, through a sequency control known per se, a cylinder valve 42 is controlled to actuate air cylinder 30 and the lowering of the presser foot of the sewing machine, after lever 26 and stop 39 have been pivoted by strip ST into a position in which the strip is to be sewed on.
Two-armed lever 36 is biased by a torsion spring (without reference numeral) having two legs, 43 and 44. Leg 43 is engaged into a bore of the holder 35, and leg 44 bears against stop 39 of lever 36. To limit the pivotal movement of lever 36 in one direction, a fixed stop 45 is provided on holder 35, and a set screw 46 is provided in a lug 47 of holder 35 to limit the movement of lever 36 in the other direction. Set screw 46 can be adjusted by means of a knurled nut. A stop screw 49 settable by a knurled nut 50 is provided for adjusting the position of supporting member 27 and the parts carried thereon, vertically.
A tension spring 31 holds supporting member 27 and stop screw 49 in contact with mounting plate 8. Supporting member 27 can be pivoted about stud 28 and against the action of tension spring 51 by means of a single-action air cylinder 52 having its piston rod 53 spring biased and applying against a projection 54 of supporting member 27.
In the path of motion of stop 39, a cam 55 is provided through which lever 36 during its return into the shown rest position actuates proximity switch 41, independently of strip ST.
The pump connections P of solenoid valves 25 and 42 are connected by flexible lines 56,57 to a compressed air source 58. The operating connection A of solenoid valve 25 is connected through a flexible line 59 to air cylinder 52, while the operating connection A of solenoid valve 42 is connected through flexible line 60 to one side, and through a flexible line 61 to the other side of double-acting air cylinder 30.
The device operates as follows:
As soon as the trailing edge of strip ST has lost contact with contact arm 18 shortly before the end of the respective sewing operation, contact arm is turned under the action of spring 22, switch arm 20 is moved away from proximity switch 23, and a sequence control is thereby started to switch off solenoid valve 25 and start the final locking operation and stopping the sewing machine, with the following cutting of the thread, lifting the presser foot, and actuating solenoid valve 42. The workpiece can then be removed.
Upon switching off solenoid valve 25, compressed air is supplied through operating connection A and flexible line 59 to air cylinder 52, so that supporting member 27 is lifted at the side of stop screw 49, aginst the action of tension spring 51. Upon switching on solenoid valve 42, one side of air cylinder 30 is vented through flexible line 60 and connection A and R and the other side is supplied through pump connection P and operating connection B of solenoid valve 42 and flexible line 61 so that piston rod 34 which is connected to the working piston displaces holder 35 with lever 36 to the stitch forming area, and stop 39 comes into the feed path of strip ST. During this motion, stop 39, under the action of torsion spring 43/44, follows the curved surface of control cam 55, so that switch arm 40 moves away from proximity switch 41.
Since presser foot of the sewing machine and stop 39 are still lifted, a new cut of fabric W can be introduced below plate 15, with the lateral edge applied against web 9 and guide edge 10 and notch 13 being aligned with a mark on slide 2 and the leading corner being aligned with a mark N on bed plate 1. Then, a strip of material ST is fed through guide apparatus 11 into the stitch forming area, until leading edge 12 comes beyond needle 7. Strip ST thus lifts contact arm 18 and causes lifting of switch arm 20, so that proximity switch 23 is actuated to deliver a control signal to solenoid valve 25 which switches into its postion 1 in which air cylinder 52 is vented through line 59 and connections A and R, wherefore member 27 is moved downwardly under the action of spring 51 and stop screw 49 is pulled into contact with mounting plate 8. In this position, stop 39 applies against cut W in a position in front of the mount of guide apparatus 11.
During the further feed motion, leading edge 12 of strip ST butts against stop 39 thereby causing pivoting of lever 36 and of switch arm 40 against the action of torsion spring 43/44 about pin 37, into contact with stop screw 46 by which the end position of stop 39 and thus the sewing position of strip ST is determined. In the end phase of the pivotal motion, proximity switch 41 is actuated whereby first solenoid valve 42 is switched off, so that air cylinder 30 is vented through line 61 and connections P and R of the solenoid valve, and the air cylinder 30 is supplied with compressed air through connection P and A of solenoid valve 42 and line 60. Thereby, through piston rod 34 connected to the working piston of air cylinder 30, holder 35 with lever 36 are returned to their rest positions and stop 39 is retracted from the feed path of strip ST.
During this retraction, lever 36 is pivoted by spring 43/44 to apply stop 39 to the curved surface of control cam 55, and moves switch arm 40 away from proximity switch 41. A sequence control of the sewing machine is thereby started by which presser foot is lowered as soon as stop 39 has left the contact area of the presser foot and after a short delay, the sewing machine is started again to perform the sewing operation beginning with some back stitches for locking the seam.
During the further reverse motion, stop 39 follows the curved surface of control cam 55, and lever 36 is pivoted again into the shown position in which switch arm 30 opposes proximity switch 41.
As mentioned above, in connection with the operation of the device, the switching processes for stopping the sewing operation are released by contact arm 18 as soon as the trailing edge of strip ST passes by.
While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles. | A device for feeding a strip of material into a sewing machine so that it can be sewed onto a cut fabric which is fed over a base plate includes a stop which is positionable in the feed path of the strip of material and which control the operation of the sewing machine so that the strip will not be fed unless it is aligned with the associated workpiece and guided past a reciprocating needle. | big_patent |
BACKGROUND OF THE INVENTION
The present invention relates to a knitting method and a knit fabric for linking a rope- or tape-shaped knit fabric in the collar of a sweater, neck rope portion of a tanktop, lower end portion of baseball stockings, a neck rope portion of an apron or the like.
For example, when forming a tape-shaped knit part in the collar portion of a sweater, in the first place, a knit fabric in a length corresponding to the peripheral edge of the collar is formed in a desired width and this tape- or rope-shaped knit fabric is sewn to the collar of the sweater by linking or other sewing means, and then the end portion of the tape- or rope-shaped knit fabric is joined by linking or other sewing means.
In the case of forming the tape-shaped rope part in the collar of the sweater as set forth above, the end portions of the rope are overlaid and joined and the thickness is increased in that portion, which is unfavorable not only for appearance but also for comfort of wearing.
Besides, sewing means such as linking is performed in a separate process from a knitting process, the productivity is impaired due to the extra sewing process, and the manufacturing cost is increased.
Furthermore, since sewing means, such as linking, is done manually, it tends to be irregular and the value of the product is lowered.
SUMMARY OF THE INVENTION
The invention is devised in the light of the above problems, and an object of the invention is to provide a connective knitting method of two tape-shaped knit pieces which is employed in a knitting procedure of a tape-shaped knit piece and a tape-shaped knit fabric knitted thereby. The method comprises steps of: knitting two tape-shaped knit pieces by a flat knitting machine possessing at least a pair of front and rear needle beds, either or both of which are composed movably in a longitudinal direction, the two tape-shaped knit pieces being positioned with a boundary between them in a longitudinal direction on either of the front and the rear needle beds; overlaying symmetrical loops of the final course of both the knit pieces across the boundary and binding off the overlaid symmetrical loops gradually; thus repeating the latter step by a proper number of times depending on the width of two tape-shaped knit pieces until the two pieces are connected by the knitting machine.
First of all, by means of a flat knitting machine possessing needle beds disposed at least in a pair of front and rear sides, with one or both thereof being composed to be movable in the lateral direction, two pieces of tape-shaped knit fabric are knitted in a specified length by arbitrary needles in different ranges across the boundary in the longitudinal direction of one of the needle beds.
In consequence, when two pieces of tape-shaped knit fabric knitted across the boundary reach a specified length, the loop portion of the final course of one of the knit fabrics is transferred to the needles of the other needle bed, which is the moving side knit fabric, the needle bed is moved so that the loop portion of the end part of the moving side knit fabric is overlaid on the loop of the end part of the part adjoining other fixed side knit fabric, and the loop of the moving side knit fabric of the overlaying part is transferred and overlaid on the loop of the fixed side knit fabric and a new loop is formed on this overlaid part.
Thus, a part of the loop of the moving side knit fabric and a part of the loop of the fixed side knit fabric are overlaid and a new loop is formed in that portion, so that one loop is decreased in the moving side knit fabric.
Next, this new loop, a part of the loop of the adjoining moving side knit fabric, and a part of the loop of the fixed side knit fabric are overlaid, and another loop of the fixed side knit fabric are overlaid, and another loop is formed on the overlaid portion, and thereby one more loop is decreased in the moving side fabric, and in addition to the decrease of one loop in the fixed side loop, two loops (three loops when starting bonding) are decreased in total.
By repeating this sequence of forming a new loop on an overlaid loop by a proper number of times depending on the width of the knit fabric, the end parts of both knit fabrics are joined and the final end portion of the junction is prevented from loosening the stitch.
BRIEF DESCRIPTION OF THE DRAWINGS
The drawings illustrate an embodiment of a connective knitting method of tape-shaped knit fabric and a connective knitting method having the end portions linked in a knitted state according to the invention, in which:
FIGS. 1A-1D are knitting diagrams in the principal courses until joining the end parts of the tape-shaped knit fabric disposed, for example, in the collar part of a sweater;
FIGS. 1E AND 1F illustrate knitting diagram in the courses for arranging the joined ends;
FIG. 2 is a plan view showing the end-to-end joined state of moving side knit fabric (a) and fixed side knit fabric (b);
FIG. 3 is a developed diagram showing the end-to-end joined state of moving side knit fabric (a) and fixed side moving fabric (b);
FIG. 4 is a magnified view of part V in FIG. 2., and
FIG. 5 is a magnified view of part V in FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, one of the embodiments of the invention is described in detail below.
The knitting machine used in this embodiment is a flat knitting machine, having multiple knitting needles disposed on needle beds laid out in a V-form in a side view in a manner free to move and slide back and forth, with the rear one of the needle beds formed movably in the lateral direction.
FIGS. 1A-1D are knitting diagrams in the principal courses until joining the end portions of the tape-shaped knit fabric disposed, for example, in the collar part of the sweater, in which the Roman numeral I denotes the forward fixed needle bed, and II is the rear movable needle bed, and the capital letters A, B, C, D, E, . . . represent the needles of the both needle beds I, II.
In the diagrams, blocks 1 and 3 are knitting courses of the tape-shaped knit pieces, one of which being a moving side knit piece (a) knitted by a knitting yarn (1) supplied from a carrier, which is out of the area of the drawing, into the knitting needles A to N among the knitting needles A, B, C, D, E, . . . , Y, Z, a, b of the fixed side knit piece (b) knitted by a knitting yarn (2) supplied from another carrier, which is out of the area of the drawing, into the knitting needles O to b. As the courses of the blocks 1 to 3 are repeated, two pieces of tape-shaped knit pieces are knitted with a boundary between the needle N and knitting needle O.
When both the moving side knit fabric (a) and fixed side knit fabric (b) are knitted to a specific length, in block 4, the rear moving needle bed II is moved (by racking) one pitch to the left in the drawing from the reference position of blocks 1 to 3, and the loop of the moving side knit fabric (a) knitted by knitting yarn (1) with knitting needles A to N is transferred to the knitting needles B to O of the moving needle bed II.
Afterwards, when the moving needle bed II is returned to the reference position, the loop stopped on the knitting needle O is confronted with the loop of the knitting needle O of the adjoining fixed needle bed I.
In block 5, the loop on the knitting needle O of the moving needle bed II is transferred to the loop of the knitting needle O of the fixed needle bed I and overlaid, and in block 6, the knitting yarn (I) is supplied to the two overlapped loops on the knitting needle O of the fixed needle bed I and a new loop is formed thereby knitting a bind-off.
At this time, the carrier for feeding the knitting yarn (I) which has moved to the right of the knitting needle O of the fixed needle bed I in block 3 moves to the left of the knitting needle O in block 4 and further, it moves to the right of the knitting needle O in block 5. Further, the carrier is returned to the left of the knitting needle O of the fixed needle bed I after block 5 before block 6, that is, what is called, "kick-back" is performed.
In block 7, the new loop formed on the knitting needle O of the fixed needle bed I in block 6 is transferred to the knitting needle O of the moving needle bed II.
In block 8, racking the moving needle bed II one pitch to the right from the reference position, the loop of the knitting needle O of the moving needle bed II is transferred to the knitting needle P of the fixed needle bed I.
In block 9, racking the moving needle bed II further to the right by one pitch (two pitches from the reference position), the loops of the knitting needle B to N of the moving needle bed II are transferred to the knitting needles D to P of the fixed needle bed I. As a result, three loops are stopped on the knitting needle N of the fixed needle bed I.
In block 10, the knitting yard (1) is supplied from the carrier to the three loops stopped on the knitting needle P of the fixed needle bed I, and a new loop is further formed. The carrier supplying the knit yarn 2 is out of the area of the drawing when it does not operate.
In block 11, after racking the moving needle bed II two pieces to the left of the reference position, the loops stopped on the knitting needles D to P of the fixed needle bed I in block 10 are transferred to the knitting needles F to R of the moving needle bed II.
In block 12, racking the moving needle bed II one pitch to the right from the state of block 11 (the position one pitch left of the reference position), the loop of the knitting needle R of the moving needle bed II and the loop of the knitting needle Q of the fixed needle bed I are overlaid, and the loop of the knitting needle R of the moving needle bed II is transferred to the knitting needle Q of the moving bed II.
In block 13, racking the moving needle bed II one pitch to the right from the state of block 12 (reference position), the loop of the knitting needle Q of the moving needle bed II and the loop of the knitting needle Q of the fixed needle bed I are overlaid, and the loop of the knitting needle Q of the moving needle bed II is transferred to the knitting needle Q of the fixed needle bed I, so that three loops are stopped on the knitting needle Q of the fixed needle bed I.
In block 14, the knitting yarn (1) is supplied from the carrier to the three loops stopped on the knitting needle Q of the fixed needle bed I, and a new loop is further formed.
In block 15, the new loop formed on the knitting needle Q of the fixed needle bed I in block 14 is transferred to the knitting needle Q of the moving needle bed II.
In block 16, racking the moving needle bed II one pitch to the right of the reference position of block 15, the loop of the knitting needle O of the moving needle bed II is transferred to the knitting needle R of the fixed needle bed I.
In block 17, racking the moving needle bed II further one pitch to the right of the position in block 16 (two pitched right of the reference position), the loop of the knitting needle P of the moving needle bed II is transferred to the knitting needle R of the fixed needle bed I, and thus three loops are stopped on the knitting needle R.
In block 18, the knitting yarn (1) is supplied from the carrier to the three loops stopped on the knitting needle R of the fixed needle bed I, and a new loop is further formed.
In block 19, racking moving needle bed II two pitches to the left of the reference position, the loops stopped on the knitting needles H to R of the fixed needle bed I in block 18 are transferred to the knitting needles J to T of the moving needle bed II.
In block 20, racking the moving needle bed II one pitch to the right of the state in block 19 (one pitch left of the reference position), the loop of the knitting needle T of the moving needle bed II and the loop of the knitting needle S of the fixed needle bed I are overlaid, and the loop of the knitting needle T of the moving needle bed II is transferred to the knitting needle S of the moving needle bed II.
In block 21, racking the moving needle bed II one pitch to the right of the state in block 20 (corresponding to the reference position), the loop of the knitting needle S of the moving needle bed II and the loop of the knitting needle S of the fixed needle bed I are overlaid, and the loop of the knitting needle S of the moving needle bed II is transferred to the knitting needle S of the fixed needle bed I, so that three loops are stopped on the knitting needle S of the fixed needle bed I. The knitting yarn (1) is supplied from the carrier to the three loops on the knitting needle S of the fixed needle bed I, and a new loop is further formed.
When the courses from block 14 to 21 are repeated in this way, the loops of the moving side fabric (a) and fixed side fabric (b) having been knitted in blocks 1 to 3 are gradually knitted in, to be bound off and dislocated from the knitting needles, and in block 22 the loops are gradually decreased until they are stopped only on the knitting needles a, b of the fixing needle bed I and knitting needle Z of the moving, needle bed II.
FIGS. 1E and 1F show the courses of terminating the joint ends, and in block 23 the loop of the knitting needle a of the fixed needle bed I is transferred to the knitting needle a of the moving needle bed II.
In block 24, racking the moving needle bed II one pitch to the right of the reference position in block 23, the loop of the knitting needle a of the moving needle bed II is transferred to the knitting needle b of the fixed needle bed I.
In block 25, racking the moving needle bed II one pitch further to the right of the state in block 24 (two pitches to the right of the reference position), and loop of the knitting needle Z of the moving needle bed II is transferred to the knitting needle b of the fixed needle bed I. As a result, three loops are stopped on the knitting needle b of the fixed needle bed I.
In block 26 the knitting yarn (1) is supplied from the carrier to the three loops stopped on the knitting needle b of the fixed needle bed I, and a new loop is formed.
The loop formed on the knitting needle b of the fixed needle bed I is locked so as not to unravel by repeating blocks 27 and 28 by a specified number of times, and is dislocated from the knitting needle b.
Specifically according to the method of this invention the end extension portion of the left front body panel is knitted by the knitting needles A to N of the front needle bed and the end extension for the right front body panel is knitted by the knitting needles O to b of the front needle bed. The end portions of the moving side knit fabric (a) and fixed side knit fabric (b) formed through these courses is joined by stitching one-by-one as if each loop were knitted in spontaneously as shown in FIGS. 2 to 5.
In the foregoing embodiment, the flat knitting machine is composed of multiple knitting needles disposed on a pair of needle beds confronting each other back and forth, but the invention may be also realized if two pairs or more of needle beds are provided.
In the illustrated example, the rear needle bed is movable, but, needless to say, the invention may be realized if the front needle bed only is movable or both needle beds are movable.
Furthermore, the matrix texture of the belt-shaped knit fabric may be plain knitting, rib knitting, tubular knitting or any other.
In addition, the invention may be realized in the neck rope part of a tanktop, a lower end portion of baseball stockings, a neck rope part of an apron, and other parts linking the tape- or rope-shaped portions.
The two pieces of knit fabric are knitted together and the transfers are carried out by a controlled computer following a designed knitting pattern. | The present invention presents a connective knitting method of tape-shaped knit ends capable of joining the end portions nearly simultaneously when knitting a tape or rope and a tape-shaped knit fabric having the end portions linked in a knit state, which comprises two pieces of tape-shaped knit fabric knitted by an arbitrary number of needles in different ranges across the boundary in the longitudinal direction of the needle beds disposed at least in a pair of front and rear sides, wherein symmetrical loops of the final course of both knit fabrics across the boundary are overlaid and knitted by binding off. | big_patent |
BACKGROUND OF THE INVENTION
[0001] The invention relates to a flexible traction element which can be wound and unwound, in particular for passenger and/or goods lifts, which comprises at least one stranded cable made of a material guaranteeing tensile strength. The invention also relates to a production line for embedding a plurality of stranded cables in a flexible thermoplastic plastics material, which production line comprises, in each case, a reel for unwinding the stranded cables, a device for the precise orientation of the stranded cables, a heater for preheating the stranded cables, at least one extruder for co-extrusion of the stranded cables in a flexible plastics material jacket, a cooling trough, a roller store, a cutting device and a storage roller. Finally, the invention relates to a method for embedding at least one stranded cable in a flexible thermoplastic material.
[0002] U.S. Pat. No. 3,348,585 relates to a method and a device for producing industrially usable bands made of rubber with strands, also called wires or threads, made of ferromagnetic material, embedded therein and running approximately in parallel in the longitudinal direction. The strands consist in particular of steel, with their magnetic properties being used as tensile and spacing forces.
[0003] GB 1362514 relates to a coiler for band-shaped lifting cables, in which steel bands are sheathed by a synthetic plastics material, in particular by polyurethane. Various flat lifting cables are shown in the drawings. FIG. 1 shows a broad, flat cable with steel strands, which are sheathed by polyurethane. Longitudinally running recesses 17 are also shown in the plastics material jacket, these being designated as insignificant. In FIG. 2 , a band-shaped lifting cable with longitudinally extending steel strands is also shown in a plastics material jacket, which has smooth surfaces on either side, in other words has no longitudinally extending recesses.
[0004] WO 03/042085 A2 describes a method for producing a lift band with a plurality of bands or braids (cords) in a flat jacket, in which the braids are oriented in a selected arrangement. A special jacket material is selected and the strands are finally individually tensioned such that they are at a uniform distance everywhere from the smooth surface of the plastics material band. The band-shaped lift band minimises the production of disturbing noises and vibrations during lift operation.
[0005] The inventor has set himself the object of providing a traction element, a production line and a method for the production thereof according to the manner mentioned at the outset, which ensure increased flexibility in a traction element with a plurality of stranded cables and also improved adhesion over the long term between the stranded cables and the plastics material jacket, and more precisely and reliably control the spacing of the stranded cables guaranteeing tensile strength from the band surfaces even at increased production speed, and deliver band-shaped traction elements of the best commercially available quality.
SUMMARY OF THE INVENTION
[0006] With respect to the traction element, the object is achieved according to the invention in that the core strand of each stranded cable is sheathed by a flexible thermoplastic plastics material layer.
[0007] In order to produce stranded cables, at least six peripheral strand cords are wound around a central strand cord designated a core strand. The strand cords themselves, which are in turn stranded, consist of individual fibres or wires of a material guaranteeing tensile strength. The flexibility of a conventional stranded cable can be considerably increased again according to the invention; the coating of the core strands prior to applying the peripheral strand cords also opens the way to higher flexibility without conventional lubricants. The thermoplastic plastics material is made at least partially capable of flowing, but without becoming highly liquid, and applied.
[0008] The thickness of the thermoplastic plastics material layer is expediently in the range of 0.1 to 1 mm, the diameter of the core strands being one of the determining factors. The temperature region applied during stranding, for example 100 to 200° C., can cause penetration of the plastics material into cable grooves, but discharge from the surface of the stranded cable is avoided as far as possible. The outer surface of the stranded cables remains bare and is expediently degreased. Individual cables are preferably covered with a protective covering, in particular in the case of larger external diameters of the stranded cable in the range of about 5 mm or more.
[0009] Stranded cables of smaller diameter, for example with a diameter of approximately 1 to 3 mm, are in practice sheathed, running in parallel, with a flexible thermoplastic plastics material, for example by a co-extrusion method, while observing optimum adhesion conditions for the plastics material jacket. The degreasing mentioned, a plasma treatment or the application of an adhesion-promoting layer, for example, contribute substantially to this. Lift bands, have, for example, eight stranded cables of 2 mm in diameter arranged on a plane, with a plastics material jacket of 25×4 mm in cross-section. The lift band is a stable composite, which is extremely flexible and forms a traction element which can easily be wound and unwound.
[0010] The individual fibres guaranteeing tensile strength, of the stranded cables are, for example steel, aramid, glass, ceramic or carbon fibres. The flexible thermoplastic plastics material sheathing the core strands of the stranded cables consists of polythene, polypropylene, polyurethane or polystyrene, for example. The stranded cables with coated core strands are preferably embedded in the same flexible thermoplastic plastics material.
[0011] In relation to the production line for sheathing at least one stranded cable with a flexible thermoplastic plastics material, the object is achieved according to the invention in that the extruder has a thread guide for the stranded cables and at least one matrix, which can be adjusted with and in relation to one another, individually, in a plane P angled with respect to the cable plane. Special and refined embodiments are in turn the subject of dependent claims.
[0012] The stranded cables run through the extruder and the outlet opening of the matrix, lying on one plane E. Above all in the case of flat traction elements, it is of substantial significance that the stranded cables lie on one plane so the parallel surfaces of the plastics material jacket have approximately the same spacing everywhere from the embedded stranded cables. By means of a relative displacement of the thread guide, which is also called a wire guide, relative to the matrix, the relative position of the stranded cables changes in the nozzle outlet opening and therefore the position of the stranded cables in the plastics material jacket also changes. The thread guide and the matrix can also be displaced together, in other words with respect to height, without their spacing changing. The plane P which is angled with respect to the cable plane E has an angle of preferably 45 to 135°; in particular, the two planes extend at an angle of about 90°.
[0013] If a plurality of stranded cables arranged in parallel run on a plane through the production line, pressure rollers may be arranged directly downstream from the extruder. These consist, for example, of at least one pair of rollers, in particular two pairs of rollers, which can be adjusted in a direction which is at right angles to the traction element passing through. Thus, the position of the stranded cables can be corrected in the still soft plastics material, but only in the fine range of a few tenths of millimetres. The pressure rollers may, however, also be arranged offset in the longitudinal direction of the traction element and thus act on the still soft composite.
[0014] Further details of the production line are shown in the drawings and correspondingly described.
[0015] Obviously, the production line can also be used for sheathing individual stranded cables or a plurality of stranded cables not located on a plane. The devices which are important to the invention, in this case, are not operated or removed if superfluous.
[0016] Finally, the object is achieved in relation to the method for embedding at least one stranded cable with a plastics material-coated core strand according to the invention in that the unwound stranded cables are degreased and/or pretreated to improve the adhesion of the plastics material jacket, preheated to a temperature of about ±20° C. of the melting temperature of the flexible thermoplastic plastics material sheathing the core strands and sheathed in the extruder with the liquefied plastics material. Special and refined embodiments are the subject of dependent claims.
[0017] The preheating takes place, for example, with an induction heater, a flame burner and/or a hot air heater. In this case, residual gases inter alia are removed and the adhesion of the plastics material sheathing and the stranded cables is improved.
[0018] The sheathing of stranded cables with a flexible thermoplastic plastics material for producing a traction element by means of co-extrusion is possible in an optimal manner owing to the inventive knowledge. The degreasing or coating of the free surface of the stranded cables with an adhesion promoting layer and the preheating to about ±20° C. of the melting temperature of the liquefied plastics material play a decisive role and overall, a sharp improvement in the adhesion between the stranded cables and the plastics material jacket is achieved. The improvement also lasts over long-term and intensive use. Even the lasting deflection around comparatively narrow radii at high tensile forces, which is the case during operation of lifts, does not impair the adhesion between the stranded cables and plastics material, or only to a negligible extent, viewed over the long term.
[0019] With the method according to the invention, the economy of the process can also be improved. A very high running speed in the region of 10 to 60 m/min. is achieved.
[0020] Each individual stranded cable is tensioned, preferably with a tensile force of 5 to 100 N, in particular 35 to 45 N. If an extruder is used with a cable guide which can be displaced in relation to the matrix, the tensioning of the stranded cables is less critical.
[0021] The geometrical cross-sectional shape of the traction elements is decisively determined by the outlet opening of the extruder, in particular when a plurality of parallel stranded cables are being sheathed with a joint plastics material. A band form is preferred with stranded cables arranged on a plane, which generally have cross-sectional external dimensions in the region of 15×1, 5 to 100×20 mm. The cross-sectional dimensions also depend, in particular, on the external diameter of the stranded cables, which is most frequently 1 to 5 mm in particular about 2 mm. The position of the stranded cables, guided in parallel, in the embedded plastics material, can be adjusted by the relative adjustment of the cable guide/matrix to ±0.1 mm accuracy. The correction range is ±0.5 to 2 mm.
[0022] In the case of stranded cables located on a plane with a jacket, which has two outer faces located parallel to the plane of the stranded cables, the relative position of the stranded cables and the outsides of the jacket can still be modified. At least two pressure rollers are preferably arranged for this purpose directly downstream from the extruder, as already mentioned. These can also provide the surface of the traction element running through with a certain structure, for example a roughened surface. In the case of traction elements located on top of one another, the coefficient of friction is thus substantially increased and the band-shaped traction elements can thus be wound to form more dimensionally stable band rolls.
[0023] The traction elements according to the invention have a wide range of use. They are particularly suitable for the lifting and pulling of loads when the traction element is deflected once or repeatedly and/or stored on a coiler. Lift bands or cables are an important application area and have to meet high safety requirements. In the case of a strand diameter of about 2 mm, they have a tensile strength of at least about 4000 kN/steel stranded cable. In the case of appropriate strand material, the traction elements may also be used as electric conductors.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The invention will be described in more detail with the aid of embodiments shown in the drawings, which are also the subject of dependent claims. In the drawings, schematically:
[0025] FIG. 1 shows a production line for producing band-shaped traction elements,
[0026] FIG. 2 shows a cross-section through various traction elements,
[0027] FIG. 3 shows a horizontal section through a thread guide and a matrix,
[0028] FIG. 4 shows a vertical section through a thread guide and a matrix with a holder, along a stranded cable,
[0029] FIG. 5 shows a vertical section through a thread guide and a matrix,
[0030] FIG. 6 shows a vertical section through a thread guide and a two-part matrix,
[0031] FIG. 7 shows a variant of FIG. 6 and
[0032] FIG. 8 shows a cross-section through a stranded cable.
DETAILED DESCRIPTION
[0033] A production line 10 shown in FIG. 1 for producing band-shaped traction elements 38 with stranded cables 16 according to FIG. 8 made of twisted steel fibres and a rectangular jacket 39 made of a flexible thermoplastic plastics material begins at a system 12 with, in the present case, two times eight reels 14 for unwinding the flexible stranded cables 16 and ends with a storage roller 18 for winding the band-shaped traction elements 38 . In industrial production systems, the production line 10 is several dozen metres long.
[0034] For the production of traction elements 38 , for example lift bands, the diameter Ø of the flexible stranded cables 16 is 2 mm in the present case. All the stranded cables 16 have to have the same, constant, diameter Ø so they can be positioned precisely in the middle of the jacket 39 made of plastics material. The diameter tolerance is at most ±0.05 mm. The stranded cable 16 must not be welded nor have twisting defects. Finally, the stranded cable 16 must be faultlessly wound onto the reel 14 .
[0035] The individual control of the tensile force of the stranded cables 16 , which is held at about 50 N, takes place in a manner which is known per se with a pneumatic or electromagnetic system.
[0036] After unrolling, the stranded cables 16 are firstly moved into a plane by way of a stand 20 with a horizontal guide slot. As the stranded cables 16 should be clean and whenever possible without volatile gas components on the surface, they are guided in-line through a cleaning system 22 .
[0037] Directly downstream from the cleaning system 22 , the stranded cables 16 pass through a further stand 24 with a device for the exact orientation of the stranded cables 16 at a constant horizontal spacing. Oriented in this way, the stranded cables 16 pass through an induction heater 26 , a flame burner 28 and a hot air heater 30 and after this preheating, the stranded cables 16 have a surface temperature in the region of 100 to 200° C. and all residual gases are removed for the subsequent plastics material coating.
[0038] The oriented, cleaned and preheated stranded cables 16 pass through an extruder 32 with a wire or thread guide and matrix according to the invention, shown in detail in FIGS. 3 to 6 . The liquefied plastics material, in the present case polyurethane, is supplied perpendicularly to the running direction 80 of the stranded cables 16 shown by an arrow. The plastics material is poured, in powder or granulate form, into a filter 34 , whence the bulk material, which is not visible, pours into a horizontal feed screw 36 . During the feed, the plastics material is liquefied and pressed by way of the thread guide into the matrix, where the stranded cables 16 passing through in parallel are sheathed with plastics material. The extruder 32 , which is known per se with the exception of the thread guide and the matrix, ensures a constant supply of plastics material and excellent quality without gelled or crystallised plastics material particles. The discharge opening 90 ( FIGS. 5, 6 ) of the matrix defines the outer dimensions of a traction element 38 which is sheathed with plastics material.
[0039] The final dimensions of a traction element 38 are established by the subsequent pressure rollers 40 made of tetrafluoroethylene (TEFLON, Du Pont) or a material coated with TEFLON. Two pairs of rollers 40 also establish the surface structure of the traction element 38 . The pressure rollers 40 must not bind with the still warm, soft material of the traction elements and have to be precisely adjustable with respect to the roller gap and the height, and be dimensionally stable. The roller surfaces are roughened in the present case and precisely cylinder jacket-shaped. This produces traction bands of elongate rectangular shape and with a roughened surface according to FIG. 2 a.
[0040] Downstream from the pressure rollers 40 , the still warm traction element 38 runs into a cooling trough 42 of 20 to 40 m in length, for example. In FIG. 1 , the cooling trough 42 is shown in very shortened form. In a first section of the cooling trough 42 , the traction element 38 can be introduced into hot water of, for example, 65° C. In one or more further sections of the cooling trough 42 , the traction element 38 is guided through cooler and cooler water, finally through normal mains or industrial water at tap temperature. According to a variant, the entire cooling trough 42 may contain unheated mains or industrial water. While passing through, the traction element 38 is guided straight, with application of a tensile stress, so contact with the side walls of the cooling system can be avoided. The cooling trough 42 may also comprise one or more returns for the traction element 38 .
[0041] Upstream and downstream from the cooling trough 42 is arranged a control apparatus 44 , 46 , in each case for controlling the thickness d of the traction element 38 , in particular. The measured dimensions are recorded and stored for the fully or partially automatic control of the production line 10 (for example adjustment of the wire unwinding 12 , the preheating 26 , 28 , 30 , the extruder 32 and the pressure rollers 40 ). Furthermore, the stored data can be used for statistical evaluations and quality reports.
[0042] The traction elements 38 are marked when passing through an automatically or manually operable inscription device 48 , for example through an inkjet printer with an ink which adheres well on the surface of the traction element 38 .
[0043] A caterpillar conveyor 50 with two continuously circulating bands ensures that a constant tractive force is exerted on the band-shaped traction element 38 and a constant running speed is maintained.
[0044] A subsequent roller store 52 , also called an accumulator, has a plurality of rollers 58 held on a static stand 54 and on a mobile stand 56 . The two stands 54 , 56 are shown with a minimal spacing, in the normal working state. In the event of a change of roller, the roller store 52 has to receive the extruded traction element 38 for about 2 minutes, while the mobile stand 56 is displaced as indicated by dashed lines counter to the running direction 80 . This mobile stand 56 is also used as a dancer and any irregularities in the band speed can be compensated by its displacement. When the roller store 52 is, for example, 70 to 75% filled, the band speed is reduced to the minimum value, which is about 10 m/min. By increasing the band speed downstream from the roller store 52 the normal working state shown by a continuous line 38 in FIG. 1 is produced as quickly as possible again.
[0045] Downstream from the roller store 52 a second caterpillar conveyor 60 is arranged according to the present embodiment with a preceding guide roller 62 on a holder 64 . A cutting device 66 arranged downstream from the second caterpillar conveyor 60 cuts the traction element 38 to length when the storage roller 18 is full. The change of the storage roller 18 is matched to the roller store 52 and the change should be complete within 2 minutes. A guide roller 68 ensures regular winding of the traction element 38 onto the storage roller 18 .
[0046] In the cross-section through a traction element 38 according to FIG. 2 a , eight stranded cables 16 with a diameter Ø of 2.00 mm are embedded on a plane E at regular intervals a of 0.5 mm. These stranded cables 16 each have a core strand 124 and six peripheral strand cords 128 of in turn seven steel fibres 130 , in each case (cf. FIG. 8 ). The stranded cables 16 have the same spacing a from the surfaces 70 , 72 . The traction element 38 has an overall thickness d of 3 mm and a width b of 25 mm.
[0047] A traction element 38 according to FIG. 2 b has a longitudinal groove 17 on either side in the centre. A constriction 15 is formed thereby.
[0048] In the embodiment according to FIG. 2 c , the traction element 38 has longitudinally extending constrictions 15 formed between the stranded cables 16 by longitudinal grooves 17 in the jacket 39 . The longitudinal grooves 17 do not impair the tensile strength of the traction element 38 , or only marginally. The traction element 38 is more flexible, however, as a whole, for example in the use as a tensioning element for fixing articles.
[0049] The outer contours of the jacket 39 are also fixed by the pressure rollers 40 ( FIG. 1 ), which have a correspondingly structured jacket surface. The matrix opening of the extruder can be configured accordingly, but may also be elongate rectangular.
[0050] FIG. 2 d shows a traction element 38 with stranded cables 16 of different thicknesses. The inner stranded cables 16 are smaller, the outer ones larger. On one side, the surface 72 of the jacket 39 is adapted to the diameter of the stranded cables 16 , a broad longitudinal groove 17 is formed, and on the other side, the surface 70 is continuously smooth. This embodiment is suitable in turn for special purposes and the outer form of the jacket 39 is established in turn by the pressure rollers 40 ( FIG. 1 ).
[0051] The embodiment according to FIG. 2 e , in contrast to the previous examples, is asymmetrical in cross-section. The stranded cables 16 of different thicknesses are connected to one another by a connection web 15 and have a jacket 39 of approximately the same thickness everywhere.
[0052] FIG. 3 shows a horizontal section through a thread guide 74 and a matrix 76 at the level of the eight bores 78 corresponding to the thread diameter Ø for the stranded cables 16 running with little play in the running direction of the arrow 80 , of which stranded cables only one is indicated as a part piece. Bores 84 run parallel to the screws 82 detachably connecting the thread guide 74 and the matrix 76 , the bores having a diameter in the present case of 6 mm for feeding liquefied plastics material compound 86 , which—invisibly on the sectional plane—is pressed into a matrix cavity 88 with the stranded cables 16 running through. The liquefied plastics material 86 sheaths the stranded cables 16 . The composite leaves the discharge slot 116 , which is elongate rectangular in cross-section, through the matrix opening 90 as a sheathed traction element 38 .
[0053] FIG. 4 shows a vertical sectional plane placed through a stranded cable 16 , through the thread guide 74 and matrix 76 according to FIG. 3 . The stranded cables 16 are in turn guided in the running direction 80 through the thread guide 74 and the matrix 76 . Prior to entry into the bore 78 , the stranded cable 16 firstly passes through an outer inlet groove 92 and an inner smaller inlet groove 94 , which simplify the production of the precise bores 78 , lying closely together, for the stranded cables 16 . A V-shaped inlet slot 96 is fed by way of the bores 84 according to FIG. 3 with liquefied plastics material compound 86 .
[0054] By means of adjusting screws 98 , 100 , which act by way of guide plates 102 , 104 on the matrix 76 , the latter can be displaced in the vertical position by Δt of at most about 0.5 mm relative to the matrix 76 . This displacement can take place at a precision of about 0.05 mm or less. In the case of a displacement of the matrix 76 by Δt, the stranded cable 16 is displaced inside the discharge slot 116 or the matrix opening 90 by the same amount. The stranded cable 16 can thus be positioned precisely inside the matrix opening 90 . The position of the stranded cables in the traction element 38 is correspondingly precise ( FIG. 2 ). The thread guide 74 can also be positioned by adjusting screws 108 and guide plates 110 in the same holder 106 as the matrix 76 , if, instead of a continuous bore 112 , adjusting screws are also arranged at the bottom in the thread guide 74 . If the thread guide 74 is also displaceable, the mutual displacement range Δt can be correspondingly enlarged between the thread guide 74 and matrix 76 .
[0055] In FIG. 5 , the thread guide 74 and matrix 76 located on one another along a plane P are shown enlarged. The continuous, tensioned stranded cable 16 runs in the direction 80 through the thread guide 74 and the matrix 76 . On displacement of the thread guide 74 along the plane P, the stranded cable 16 is entrained, because it is guided with very little play through the bore 78 ( FIG. 4 ). If the matrix 76 is displaced with the thread guide 74 fixed, the stranded cable 16 remains untouched thereby. However, as the vertical position of the discharge slot 116 with the matrix opening 90 changes, the distance of the stranded cable 16 from the upper and lower limitation of the discharge slot 116 is changed. Thus the position of the stranded cable 16 in the centre of the discharge slot 116 can be established precisely by a simple displacement of the matrix 76 along the plane P in the vertical direction by one or a few tenths of millimetres. Therefore, the stranded cable 16 is adjusted precisely in the centre of the traction element 38 , i.e. the jacket 39 is the same size on the upper and lower apex of the stranded cable.
[0056] In the embodiment according to FIG. 6 , for co-extrusion, a further matrix 75 is arranged between the thread guide 74 and the matrix 76 and the same plastics material jacket 39 ( FIG. 5 ) is applied consecutively in a spatially separated manner.
[0057] The matrix 76 for the traction element 38 ( FIG. 5 ) has a projecting collar 114 with a lengthened discharge slot 116 and a discharge opening 90 . Owing to the arrangement of the collar 114 , the plastics material jacket 39 can cool better and harden better before discharge from the matrix opening 90 .
[0058] The thread guide 74 comprises two peripheral bores 118 and two V-shaped inlet slots 96 , also for the liquefied plastics material 86 . The holes 78 for passage of the stranded cables 16 remain substantially unchanged, as do the outer and inner inlet groove 92 , 94 .
[0059] The further matrix 75 arranged between the thread guide 74 and the matrix 76 comprises two V-shaped inlet slots 96 , which guide the fed liquefied plastics material 86 from the peripheral bores 118 to the matrix cavity 88 . An advanced matrix cavity 120 is fed through the V-shaped inlet slot 96 in the thread guide 74 . From this matrix cavity 120 , a connection channel 122 leads to the matrix cavity 88 in the matrix 76 , this connection channel 122 having a slightly larger diameter than the advanced bore 78 . The stranded cable 16 passing through reaches the matrix cavity 88 already precoated.
[0060] According to a variant shown in FIG. 7 , the thread guide 74 according to FIG. 6 is designed such that an impregnation means 87 for the stranded cable 16 is guided through the inlet slots 96 into the advanced matrix cavity 120 . The liquefied plastics material compound 86 is guided through the inlet slots 97 into the matrix cavity 88 . Obviously, various liquefied plastics material compounds 86 can also be guided through the inlet slots 96 , 97 .
[0061] FIG. 8 shows a cross-section through a stranded cable 16 . A central strand cord, the core strand 124 is sheathed with a flexible thermoplastic plastics material layer 126 , in the present case polyurethane. When stranding with six strand cords, the peripheral strand cords 128 , the plastics material layer which is capable of flowing or viscous deforms and flows into the cable grooves. The individual fibres 130 of the core strand 124 and peripheral strand cords 128 are stranded in a manner which is known per se.
[0062] A stranded cable 16 with an outer diameter of at least about 5 mm, for example, can, as a single cable, achieve the tensile force required for a traction element. The stranded cable is preferably protected with an outer jacket made of plastics material.
[0063] Stranded cables 16 with a smaller diameter are guided in parallel through a production line 10 according to FIG. 1 , sheathed with a plastics material 39 and used as a traction element 38 with a plurality of stranded cables 16 .
[0064] The coating of a stranded part 16 or a core strand 124 can take place in any manner which is known per se or preferably with a modified production line according to FIG. 1 , using the method according to the invention. | A flexible traction organ that can be wound and unwound, in particular for passenger and/or goods lifts, said organ comprising at least one stranded cable consisting of a tensile resistant material. The core strand of each stranded cable is surrounded by a flexible thermoplastic plastic layer. A production line for embedding several stranded cables in a flexible thermoplastic layer comprises a respective reel for unwinding the stranded cable, a device for accurately aligning the stranded cable, a heating element for pre-heating the stranded cable, at least one extruder for co-extruding the stranded cable in a flexible plastic sheathing, a cooling vat, a reel storage unit, a cutting unit and a reserve reel. The extruder, a wire guide and at least one die can be adjusted individually, conjointly and in relation to one another on a plane (P) that runs at an angle to the cable plane (E). The unwound stranded cables are degreased and/or pre-treated to improve the adhesion of the plastic sheathing, and pre-heated to a temperature of approximately ±20° C. in relation to the melting temperature of the flexible, thermoplastic plastic that surrounds the core strand and are sheathed with liquefied plastic in the extruder. | big_patent |
FIELD AND BACKGROUND OF THE INVENTION
The invention relates in general to sewing machines and in particular to a new and useful rotary hook arrangement for a lockstitch sewing machine.
A sewing machine similar to the invention is disclosed in U.S. Pat. No. 4,137,858 to Stepel et al. In the case of the rotary hook of this sewing machine the bobbin capsule carrier of the bobbin housing has a laterally projecting holding finger which for the rotationally secured retention of the bobbin housing engages between two cams disposed on the underside of the stitch plate near the stitch hole. Associated with the rotary hook is a spring rod clamped fixed, which cooperates with an abutment surface of a cutout in the bobbin capsule. The cutout is located at a distance before the holding finger in the direction of hook rotation. The spring rod is arranged and dimensioned so that the holding finger is approximately centered between the two cams when the sewing machine is running, so that a thread passage gap is formed on both sides of the holding finger. As a result, it is possible both at the beginning and at the end of the looping around the bobbin housing to move the needle thread loop through the rear and then through the front thread passage gap without using a capsule release device and without having to rotate the bobbin housing. During the looping of the needle thread loop the spring rod is merely bent back briefly by the needle thread. As the spring rod has little mass, it offers not appreciable resistance if the spring force is rated correctly.
Although the thread passage gaps are wide enough, after the guiding of the needle thread loop around the bobbin housing, a brief impediment of the thread movement occurs nevertheless during the upward pull-back. This is because the lower edge, turned toward the holding finger, of the front cam projects into the pull-off path of the needle thread loop and briefly retains the upwardly moved needle thread loop, which toward the end of the pull-back spins in part uncontrolled, until it snaps off the cam laterally into the thread passage gap. Due to this retention effect of the front cam, coming into play in particular at high rotational speed, the needle thread tension increased in an undesirable manner.
By German OS No. 33 03 033 to Rampack it is proposed to connect the holding finger which serves to prevent rotation of the bobbin housing firmly with the base plate outside the area of the stitch hole and to let its free end engage radially to the hook axis into a U-shaped cutout in the bobbin capsule. Preferably the holding finger is to be arranged diameterically to the stitch hole. By moving the holding means which serve to prevent rotation of the bobbin housing into a region diametrically opposite the stitch hole, it is now indeed possible to pull the needle thread loop upward unhindered after completed looping around the bobbin housing. However, then an impediment of the thread movement occurs during the guiding of the needle thread loop around the bobbin housing, in that it must squeeze through between the holding finger and the abutment faces of the cutout at the time of its greatest expansion.
Lastly there is known from German Pat. No. 31 02 457 a rotary hook revolving about a horizontal axis which to secure the bobbin housing against rotation is associated with a spring-loaded holding finger arranged on a support and with a cam on both sides of the holding finger. The holding finger and what in the direction of hook rotation is the rear cam span a finger formed at the bobbin capsule carrier. The front cam forms a support for the spring loaded holding finger. As the housing side holding means are arranged in the vicinity of the stitch hole, the pull-back of the needle thread loop is impeded, as in the case of the first named rotary hook, so that consequently one must operate with increased needle thread tension.
SUMMARY OF THE INVENTION
The invention provides a lockstitch sewing machine having a rotary hook where the holding means which prevent co-rotation and reverse rotation of the bobbin housing are arranged so that they hinder the guiding of the needle thread loop and in particular the pull-back occurring after its maximum expansion, as little as possible.
Since all housing side holding means are located on the loop cast-off side of the bobbin housing, the needle thread loop can be expanded totally unhindered until its maximum expansion is reached. On the loop cast-off side the needle thread loop is then pulled back by the thread take-up lever, the loop sliding at first still along the outer surface of the bobbin housing and thereafter along the front side face of the shoulder. In this manner the needle thread loop moves, without touching the front cam, through the gap between the latter and the shoulder and only thereafter it causes a brief bending of the low-mass spring rod. As little force is required for this, the bending of the spring rod causes only a slight increase of the needle thread tension. Since the rear cam serves only as a supporting element for the spring rod and comes in contact neither with the bobbin housing nor with the needle thread loop, the needle thread loop can, after having been moved through under the spring rod, be pulled back through the stitch hole by the thread feeder totally unhindered.
By a further feature of the invention, the slight impediment of the thread movement caused by the bending of the spring rod can be eliminated completely in that the capsule release device gives the bobbin housing a rotational impulse counter to the direction of hook rotation, so that the rear side face of the shoulder briefly moves away from the spring rod by the dimension of the thread thickness, so that the needle thread loop can slip through the thread passage gap thus created, entirely unhindered. In this case the needle thread tension required for satisfactory stitch formation can be reduced to a minimum. However, one must watch that during the reverse rotation of the bobbin housing the thread passage gap between the front side face of the shoulder and the front cam, serving as reverse rotation protection, remains large enough for the thread movement to take place unhindered as before at this point.
Accordingly it is an object of the invention to provide a rotary hook arrangement for a lockstitch sewing machine which includes first and second cams arranged on respective sides of a projection of the bobbin housing of a rotatable hook for controlling the rotation of the bobbin housing with the rotary hook housing which includes the spring rod extending between cams which cooperate with a projection of the housing.
A further object of the invention is to provide a rotary hook arrangement for a lockstitch sewing machine which is simple in design, rugged in construction and economical to manufacture.
The various feature of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which a preferred embodiment of the invention is illustrated.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a side elevational view of a sewing machine constructed in accordance with the invention;
FIG. 2 is an enlarged elevational view of the rotary hook and the capsule release device;
FIG. 3 is a perspective view of the rotary hook; and
FIG. 4 is a side sectional view of the rotary hook taken along line IV--IV of FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings in particular the invention embodied therein comprises a rotary hook arrangement shown in detail in FIGS. 2, 3 and 4 for a locksewing machine shown in FIG. 1.
The lockstitch sewing machine comprises a base plate 1, a standard 2, and an arm 3 with a head 4. In arm 3 is mounted an arm shaft 5, which is in drive connection with a needle bar 7 movable up and down in the head 4 and carrying a threaded needle 6. Also mounted in head 4 is the thread take-up lever 8, which in known manner cooperates with the needle 6 and executes an up and down movement, and which is also driven by an arm shaft 5. The head 4 carries a thread tensioning device 9.
Secured on the arm shaft 5 is a belt pulley 10 which, via a belt 11 and a belt pulley 12, transmits the drive movement of the arm shaft 5 to the rotary hook drive shaft 13 mounted in the base plate 1, in the ratio 1:1. Secured on the rotary hook drive shaft 13 is a bevel gear 14 which meshes with a counter-gear 16, disposed on the vertical rotary hook shaft 15 and thus drives the lockstitch rotary hook 17 disposed at the upper end of the hook shaft 15 and revolving in a horizontal plane.
The lockstitch rotary hook 17 has a hook body 18 and a hook tip 19 formed thereon. A bobbin housing 20 is supported in the hook body 18, and it comprises a bobbin capsule carrier 21 and a removable bobbin capsule 22. At the bobbin capsule 22 and at the bobbin capsule carrier 21, in the same plane, two projections 25,26 laterally projecting from the outer surface 23 of the bobbin housing 20 are arranged, which together form a triangular shoulder 27. The outer side face of projection 25 forms what in the direction of hook rotation A is the front side face 28 of shoulder 27. The outer side face of the projection 26 forms the, in direction A, rear side face 29 of shoulder 27. The front and rear side faces 28, 29 of the two projections 25, 26 jointly forming the shoulder 27 are tangential to the generated surface 23 of the bobbin housing 20.
In the bobbin housing 20, on a bobbin the rotary hook thread G is arranged in known manner. It runs through a thread opening 30 in projection 26 and thence to the stitch hole 31 of the stitch plate 32 recessed in top of the base plate 1. The shoulder 27 lies in the central region of the loop castoff side 51, of the bobbin housing 20. The loop castoff side 51 lies in the region of that half of the outer surface 23 which according to FIG. 2 lies outside a line conceived to extend through the stitch hole 31 and the axis of rotation of rotary hook 17.
At a carrier 33 attached to the base plate 1, a front cam 34, and, spaced therefrom a rear cam 35 is formed. By a screw 36, a spring rod 37 extending between the cams 34,35 is fastened to the carrier 33. The free end of the spring rod 37 is located between the rear side face 29 of shoulder 27 and the rear cam 35, leaving a gap between the free end of spring rod 37 and the free end of the rear cam 35. With the sewing machine running, the bobbin housing 20 takes support by engagement of the rear side face 29 of the shoulder 27 on the spring rod 37, whereby the rod hinders the bobbin housing 20 against co-rotating with the hook body 18. When the bobbin housing 20 abuts by the rear side face 29 against the spring rod 37, a relatively large gap 39 is formed between the free end of the front cam and the front side face 28 of shoulder 27.
On the hook drive shaft 13 an eccentric 40 is secured, which has a spherical circumferential surface. The eccentric 40 is spanned by one end of an eccentric rod 41, the other end of which is arranged at a crank 45 secured on a vertically mounted shaft 44. On shaft 44, a horizontally extending finger 46 is clamped, the free end of which projects a small distance into a cutout 47 in the bobbin capsule 22. The cutout 47 is offset relative to the stitch hole 31 of the stitch plate 32 by substantially 180°. Depending on the position of eccentric 40, a gap 49 exists between the finger 46 and an abutment surface 48 of cutout 47, or the finger 46 applies against the abutment surface 48 and in so doing rotates the bobbin housing 20 counter to the direction of hook rotation A. The parts 40 to 46 form a capsule release device 50.
The hook tip 19 having seized the needle thread loop N formed by needle 6 at the beginning of a stitch formation process, the loop is expanded by the revolving hook body 18 for looping around the bobbin housing 20, whereby the slack previously produced by the thread take-up lever 8 is used up. At the time of its greatest expansion the needle thread loop N moves through the gap 49 between the finger 46 and the abutment surface 48 without being hindered by finger 46. Thereafter the thread feeder 8 begins to pull back the needle thread loop N.
Immediately after the needle thread loop N has traversed the gap 49, the eccentric 40 moves the finger 46 against the abutment surface 48 and gives the bobbin housing 20 slight rotational impulse counter to the direction of hook rotation A. Due to this rotational impulse the bobbin housing 20 is rotated only so far counter to the direction of hook rotation A that there forms between the rear side face 29 and the spring rod 37 only a narrow gap approximately corresponding to the thickness of the needle thread, and the width of the gap 39 between the front side face 28 and the front cam 34 is reduced correspondingly little.
Although the angle distance between the abutment surface 48 for finger 46 and the point of contact of the spring rod 37 against the rear side face 29 is only about 120°, the capsule release device 50 can nevertheless create the gap between the rear side face 29 and the spring rod 37 in good time, namely due to the fact that the capsule release device 50 is driven at the same speed as rotary hook 17 and that the bobbin housing 20 is rotated back by only a relatively small amount.
In the course of the pull-back movement, the needle thread loop N drops off the hook tip 19, moves unhindered through the sufficiently wide gap 39, then slides almost jerklessly over the tip of the shoulder 27, and finally moves unhindered through the gap briefly created by the capsule release device 50 between the rear side face 29 and the free end of the spring rod 37. Thereafter the needle thread loop N is pulled back completely through the stitch hole together with a section of the hook thread G.
Since during its entire guiding movement around the bobbin housing 20 the needle thread loop N experiences no impediment except for the slight deflection around the shoulder 27, the rotary hook 17 is outstanding for an especially jerk-free and low friction motion of the needle thread loop N.
But also without the use of a capsule release device the rotary hook 17 has comparatively good sewing properties. In that case the low mass spring rod 37 is bent back by the amount of the thread thickness by the needle thread loop N. Since little force is required for the bending back if the spring rod 37 is suitably dimensioned, the motion of the needle thread loop N is hindered only correspondingly little. This force to be supplied by the thread take-up lever 8 and acting on the needle thread does indeed entail that the needle thread tension to be adjusted at the thread tension device 9 is somewhat higher than with the use of the capsule release device 50, the slightly increased needle thread tension is still definitely lower than with conventional rotary hooks.
While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles. | A lockstitch sewing machine includes a rotary hook. For the rotation secure retention of the bobbin housing of the hook, two cams are arranged in the central region of the loop cast-off side, which receive a spring rod between them. A shoulder formed at the bobbin housing is associated with the cam or with the spring rod. Through the special position of the cams, the movement resistances during the guiding of the needle thread loop around the bobbin housing is reduced to a minimum. | big_patent |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a 35 U.S.C. §111(a) continuation of PCT international application number PCT/US2012/000497 filed on Oct. 3, 2012, incorporated herein by reference in its entirety, which claims the benefit of U.S. provisional patent application Ser. No. 61/542,591 filed on Oct. 3, 2011, incorporated herein by reference in its entirety. Priority is claimed to each of the foregoing applications.
[0002] The above-referenced PCT international application was published as PCT International Publication No. WO 2013/103332 on Jul. 11, 2013 and republished on Oct. 10, 2013, which publications are incorporated herein by reference in their entireties
[0003] This application is also related to PCT international application number PCT/US11/31478, filed on Apr. 6, 2011, which is claims priority to U.S. provisional patent application Ser. No. 61/321,338 filed on Apr. 6, 2010, incorporated herein by reference in its entirety. The foregoing PCT international application was published as PCT International Publication No. WO 2011/127218 on Oct. 13, 2011 and republished on Feb. 2, 2012, and is incorporated herein by reference in its entirety.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0004] This invention was made with Government support under EPS-0447679 awarded by North Dakota EPSCoR/National Science Foundation and under H94003-09-2-0905 awarded by the DoD Defense Microelectronics Activity (DMEA). The Government has certain rights in the invention.
INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED IN A COMPUTER PROGRAM APPENDIX
[0005] Not Applicable
BACKGROUND OF THE INVENTION
[0006] 1. Field of the Invention
[0007] This invention pertains generally to synthesis schemes and methods for producing silicon based nanostructures and materials, and more particularly to compositions and methods for synthesis of silicon-based nanowires and composites from four-component inks comprising a liquid silane, a polymer, an accelerant and a solvent and five-component inks comprising a liquid silane, a polymer, an accelerant, a solid phase and a solvent.
[0008] 2. Description of Related Art
[0009] The beneficial electrical and electrochemical properties of silicon have been demonstrated in integrated circuits, solar cells and battery electrodes. However, such materials are typically produced by chemical vapor deposition or by etching a Si wafer and these processes are not amendable to continuous manufacturing schemes such as roll-to-roll manufacturing.
[0010] There is also increased interest in replacing carbon-based materials with silicon or silicon-based compounds in the anodes of next-generation lithium ion batteries (LIBs). Silicon has a theoretical capacity of approximately 4200 mAh/g, which is more than ten times greater than the 372 mAh/g capacity of conventional graphite anode materials. Therefore, Si-based anodes could increase the energy density of lithium ion batteries significantly.
[0011] However, fully lithiated silicon (Li 22 Si 5 ) undergoes a greater than 300% volume expansion during the lithiation and delithiation process which leads to mechanical failure of the silicon structure within a few cycles producing a significant and permanent loss of capacity. A number of approaches toward the development of silicon-containing anodes have been attempted. One approach was the use of a homogeneous dispersion of silicon particles within a suitable matrix to give composites that have improved mechanical stability and electrical conductivity versus pure silicon. It has been shown that silicon nanowires or fibers are able to accommodate the expansion that occurs during cycling. However, significant numbers of Si-nanowires (SiNWs) are needed for practical anode applications.
[0012] A Vapor Induced Solid-Liquid-Solid (VI-SLS) route to produce Si-nanowires has been proposed that uses bulk silicon powders thus offering the possibility of scalable and cost-effective mass manufacture without the need for a localized catalyst on a substrate. The VI-SLS process, however, is complicated by high process temperatures that tend toward the formation of carbide and oxide phases that limit electrochemical capacity and rate capabilities.
[0013] Another approach to the production of silicon nanowires is through electrospinning where the electrospun polymer fiber serves only as a template for the growth of silicon coatings by hot-wire chemical vapor deposition (CVD) or plasma enhanced CVD (PECVD). While these synthesis routes do allow the growth of a-Si nanowires with hollow cores, hot-wire and PECVD methods suffer from poor precursor utilization and traditionally slow rates of growth.
[0014] Accordingly, there is a need for an apparatus and method for reliably producing silicon based nanowires and films that are inexpensive and amenable to continuous roll-to-roll operation. The present invention satisfies these needs as well as others and is generally an improvement over the art.
BRIEF SUMMARY OF THE INVENTION
[0015] The present invention is directed to materials and methods for producing silicon based micro and nanofibers that can be used in a variety of applications including material composites, electronic devices, sensors, photodetectors, batteries, ultracapacitors, and photosensitive substrates and the like.
[0016] Liquid silanes have been considered as precursors in direct-write fabrication of printed electronics as well as in the production of silicon microwires and nanowires. Cyclohexasilane (Si 6 H 12 ), for example, can be transformed into solid polydihydrosilane (SiH 2 ) n by thermal treatment or light activation via radical polymerization. Additional thermolysis causes evolution of H 2 (g) giving a-Si:H at approximately 350° C. and crystalline silicon at approximately 750° C.
[0017] Marked microstructural changes, however, are associated with this thermolytic transformation. The thermal conversion of Si 6 H 12 -derived films and/or (SiH 2 ) n into a-Si occurs with marked shrinkage at around 290° C. and it appears to be related to the evolution of SiH 2 and SiH 3 fragments. This phenomenon may limit electrical transport as a result of microcracking within these thin films. This shrinkage does not lead to cracking when the films are less than a thickness of approximately 200 nm. The electrospinning methods of the present invention appear to manage the stress, in part, by reducing the dimensionality from 2D films to 1D wires.
[0018] Electrospinning, according to the invention, is a viable method for utilizing liquid cyclosilanes (i.e., Si n H 2n ) and linear or branched silanes (i.e., Si n H 2n+2 ) in the fabrication of electronic materials as these monomers are transformed directly into a useful form (i.e., a nanowire) prior to the formation of the insoluble (SiH 2 ) n network polymer. The lateral cohesive stresses that promote cracking in the aforementioned 2D thin films are well managed in 1D wires where radial shrinkage does not lead to the observed deleterious microstructural changes of larger silicon structures.
[0019] Electrospinning is a continuous nanofabrication technique based on the principle of electrohydrodynamics, and it is capable of producing nanowires of synthetic and natural polymers, ceramics, carbon, and semiconductor materials with the diameter in the range of 1 nm to 2000 nm. While the Taylor cone instability associated with electrospinning was historically used for nozzle-based systems, the surface instability of thin polymer-in-solution films in the presence of an electric field enabled the development of needleless electrospinning whereby numerous jets spin coincidently allowing a continuous, roll-to-roll manufacturing process. Additionally, continuous needleless electrospinning that utilizes a rotating cone as the spinneret has been demonstrated with production throughput of up to 10 g/minute.
[0020] This is in stark contrast to the two common silicon nanowire preparation methods known in the art where the ability to scale up appears to be limited by wafer size (i.e., when forming Si nanowires via wafer etching) or a growth temperature of approximately 363° C. (i.e., Au—Si eutectic in vapor-liquid-solid growth). In each instance, the transition to a continuous roll-to-roll manufacturing process is not straightforward and may not be possible.
[0021] It has been observed that the liquid silane monomers that are used in the invention are relatively unaffected by the high-voltage electrospinning process and remains associated with the polymeric carrier (i.e., poly(methyl methacrylate (PMMA) or polypropylene carbonate/polycyclohexene carbonate (QPAC100™, Empower Materials)) upon evaporation of the toluene or other solvent. Light-induced or heat-induced radical polymerization of the Si 6 H 12 gives a viscous polydihydrosilane deposit that assumes a geometry that is related to the structure of the copolymer. The structure of the silicon nanowires prepared from Si 6 H 12 /polymer carrier in toluene mixtures appears to be governed by the physics of the copolymer mixtures. For example, scanning electron micrograph (SEM) data shows that a fibrous structure is formed after treatment of an electrospun composite formed from a 1.0:2.6 wt % ratio of Si 6 H 12 /PMMA in toluene ink. This structure appears to be related to wetting of the polymer by the liquid silane after solvent evaporation. By way of comparison, thermolysis of the composite formed by electrospinning a 1.0:2.0 wt % ratio of Si 6 H 12 /QPAC100 in toluene precursor gives a porous wire where it appears the liquid silane and polymer carrier exist as a microemulsion and phase separate after solvent evaporation.
[0022] It has also been observed that the electrospinning of four-component Si 6 H 12 /polymer/accelerant inks gives products where the active silicon agent forms after the precursor is transformed to nanosized material. The approach offers the ability to tailor chemical composition of Si wires by adjusting precursor chemistries to give electrospun composites that possess targeted conductivities (electrical, thermal and ionic) and maintain structural stability throughout a lifetime of charge/discharge cycles. Barring any undesirable chemical reactivity with Si—Si or Si—H bonds, particles of carbon, metals and solid electrolytes can also be introduced into liquid silane-based electrospinning inks using standard dispersion chemistry to produce a five-component ink. Because the spun wires convert to amorphous silicon at relatively low temperature, formation of excessive surface oxide and carbide phases can be avoided, which otherwise negatively affect capacity and rate capabilities. It is important to note that other routes to Si wires yield crystalline products that become amorphous after lithium intercalation in LIBs.
[0023] The four-component and five-component inks that are disclosed are particularly useful with electrospinning procedures and the formation of micro and nanofibers are used as an illustration. However, the inks can also be used with other deposition techniques such as thin film deposition techniques. In addition, single or coaxial nozzle formation of nanofibers is used to illustrate the methods. However, it will be understood that the inks and methods of the invention are appropriate for any electrospinning technique including use with devices that have multiple nozzles, drums or films.
[0024] By way of example, and not of limitation, a preferred method for making silicon-containing wires with a four-component ink generally comprises the steps of: (a) combining a liquid silane of the formula Si n H 2n or Si n H 2n+2 , a polymer, an accelerant and a solvent to form a viscous solution; (b) expelling the solution from a source while exposing the stream of viscous solution to a high electric field resulting in the formation of continuous fibers that are deposited onto a substrate; and (c) transforming the deposited fibers, normally with thermal processing.
[0025] In another embodiment of the invention, a preferred method for making silicon-containing wires with a five-component ink generally comprises: (a) combining a liquid silane of the formula Si n H 2n or Si n H 2n+2 , a polymer, a solid phase, an accelerant and a solvent to form a viscous solution; (b) expelling the viscous solution and exposing the viscous solution to a high electric field whereby continuous fibers form from the solution and are deposited onto a substrate; and (c) transforming the electrospun deposit.
[0026] The solid phase components are preferably particulates of many different types such as metal spheres, silicon nanowires, and carbon particulates including nanotubes, as well as dopants, and metal reagents. For example, metal silicide wires can be formed with addition of metal reagents.
[0027] The polymers are preferably either an acrylate such as poly(methyl methacrylate) or a polycarbonate. The preferred solvents are toluene, xylene, cyclooctane, 1,2,4-trichlorobenzene, dichloromethane or mixtures thereof.
[0028] A wide variety of polyhydropolysilanes can act as accelerants for the polymerization of cyclohexasilane, Si 6 H 12 (CHS). Polyhydropolysilanes of formula Si n H n+2 , linear or branched, individually, or in combination, accelerate the polymerization of CHS when added to CHS. Polyhydropolysilanes composed of one or more polyhydrocyclopolysilane rings attached to another polyhydrocyclopolysilane, with or without the presence of substituents on the ring, will accelerate the polymerization of CHS when added to CHS.
[0029] CPS (cyclopentasilane, Si 5 H 10 ), when mixed with CHS, will accelerate the polymerization of CHS when added to CHS. Silylcyclopentasilane also accelerates polymerization and film formation. This structure has the formula of Si 6 H 12 , but is comprised of a five membered ring of silicon atoms with the 6 th silicon attached to the ring.
[0030] The substrate is preferably a metal foil. However, the substrate may also be a carbon fiber matte, metal web or rotating mandrel.
[0031] Transformation of the deposit is preferably by thermal treatment or light activation via radical polymerization. Transformation of the deposited nanofibers can take place at any time or location and need not take place on the substrate.
[0032] In certain embodiments, the methods for producing silicon based nanofibers may further include the step of coating the fibers with an electrically conductive material. The preferred coating is a coherent, ion conductive coating of carbon such as graphite, C black, graphene, KB carbon or carbon nanotubes. The coating of the fibers is preferably applied by chemical vapor deposition or solution deposition.
[0033] The silicon-based materials and nanofibers that are produced by the three- and four-component inks can be used in a variety of applications including as an active component in other composite materials. For example, electrically-conducting silicon composite electrodes can be produced with a four-component ink according to the invention by (a) combining a liquid silane of the formula Si n H 2n , or Si n H 2n+2 , a polymer and accelerant and a solvent to form a viscous solution; (b) expelling the viscous solution into the presence of a high electric field where continuous fibers are formed and deposited onto a substrate; (c) transforming the deposit into a material that contains a polysilane, an amorphous silicon and/or a crystalline silicon fraction with or without a binder; (d) forming a coherent, conductive coating on the external porosity of the silicon-containing fraction and (e) binding the material with one or more binders. The preferred binders include poly(vinylidene fluoride-co-hexafluoropropylene) or sodium carboxymethylcellulose or an elastic carbon such as KB carbon. Some binders can be thermally decomposable.
[0034] Another example of a composite material that can be produced is an electrically-conducting photoactive silicon-composite electrode material using a five-component ink. This material can be produced by (a) combining a liquid silane of the formula Si n H 2n or Si n H 2n+2 , a polymer, a photoactive solid phase, an accelerant and a solvent to form a viscous mixture; (b) expelling the viscous mixture into the presence of a high electric field where continuous fibers of the mixture are formed and deposited onto a substrate; (c) transforming the deposit into a material that contains an amorphous silicon and/or a crystalline silicon fraction and a photoactive phase; and binding the transformed material with a binder. The preferred photoactive phase can be a carbon fullerene, a carbon nanotube, a quantum dot of CdSe, PbS, Si or Ge, a core-shell quantum dot of ZnSe/CdSe or Si/Ge.
[0035] Accordingly, an aspect of the invention is to provide four-component or five-component silane inks that can be used in the formation of silicon based films and nanofibers and composite materials.
[0036] Another aspect of the invention is to provide liquid silane electro-spinning inks that include an accelerant for increased setting or curing times
[0037] Another aspect of the invention is to provide methods for producing polysilane nanowires and materials.
[0038] Another aspect of the invention is to provide a method for continuous production of nanofiber strands and coated nanofiber strands.
[0039] A further aspect of the invention is to provide silicon based fibers that can be used as a component in a variety of composite materials such as electrode composites.
[0040] Further aspects of the invention will be brought out in the following portions of the specification, wherein the detailed description is for the purpose of fully disclosing preferred embodiments of the invention without placing limitations thereon.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0041] The invention will be more fully understood by reference to the following drawings which are for illustrative purposes only:
[0042] FIG. 1 is a flow diagram of a method of forming silicon based nanofibers from a three-component ink according to one embodiment of the invention.
[0043] FIG. 2 is a flow diagram of a method of forming silicon based nanofibers from a four-component ink according to another embodiment of the invention.
[0044] FIG. 3 is a flow diagram of a method for producing an electrode material from carbon coated silicon nanofibers formed according to one embodiment of the invention.
[0045] FIG. 4 is a schematic diagram of the processing of cyclohexasilane and PMMA in toluene, a three-component ink, to produce transformed nanofibers.
[0046] FIG. 5 is a schematic diagram of the processing of cyclohexasilane and QPAC100 in toluene, a three-component ink, to produce transformed nanofibers.
[0047] FIG. 6 shows Raman spectra of electrospun four-component samples after heat treatment at 550° C. for one hour and laser crystallization for CdSe, C black, graphite, Ag, amphiphilic invertible micelle (AIP), BBr 3 and PBr 3 .
DETAILED DESCRIPTION OF THE INVENTION
[0048] Referring more specifically to the drawings, for illustrative purposes one embodiment of the present invention is depicted in the methods generally shown in FIG. 1 through FIG. 6 . It will be appreciated that the methods may vary as to the specific steps and sequence and the apparatus may vary as to structural details, without departing from the basic concepts as disclosed herein. The steps depicted and/or used in methods herein may be performed in a different order than as depicted in the figures or stated. The steps are merely exemplary of the order these steps may occur. The steps may occur in any order that is desired, such that it still performs the goals of the claimed invention.
[0049] The present invention provides methods for producing silicon containing nanowire/fiber composites and thin films that are produced from liquid silane inks by electrospinning as an illustration of an adaptation of the invention. Nanowire products from four-component and five-component liquid silane based “ink” compositions are produced and characterized to demonstrate the compositions and methods. The exemplary nanowires that are produced by the methods can be used as a component of other material compositions such as an anode for a lithium ion battery.
[0050] Turning now to FIG. 1 , the steps according to a preferred embodiment 10 of the present method for producing a silicon based nanowire material using four-component liquid silane inks with an optional conductive coating is illustrated. At block 12 , a solution of a liquid silane, a polymer, an accelerant and a solvent is provided. The resulting viscous solution preferably has a viscosity of between approximately 100 cP to approximately 10,000 cP for electrospinning procedures.
[0051] The preferred liquid silane has the formula Si n H 2n , where n=3, 4, 5, 6, 7 or 8. Linear and branched liquid silanes of the formula Si n H 2n+2 , where n=3, 4, 5, 6, 7 or 8 may also be used. Mixtures of one or more of these silanes may also be used.
[0052] Cyclohexasilane (Si 6 H 12 ) is a particularly preferred cyclosilane. Liquid Si 6 H 12 is preferably synthesized by reduction of a chlorinated salt prepared from trichlorosilane (HSiCl 3 ). Cyclohexasilane is a high melting point liquid (18° C.) that is stable toward reduced-pressure distillation as well as ambient light. Si 6 H 12 has been shown to be stable to room temperature fluorescent light for days and it can be stored for months in the solid state without marked degradation. Si 6 H 12 is stable toward ultrasonic atomization and has been used as a precursor in collimated aerosol beam direct write deposition of a-Si lines. In addition, Si 6 H 12 is stable when subjected to high voltage processing and electrospinning procedures to yield a-Si nanowires that may find application as anodes in lithium ion batteries and other materials.
[0053] In the embodiment shown in FIG. 1 , Si 6 H 12 undergoes ring opening polymerization under heat or prolonged exposure to laser light with additional thermal treatment transforming the solid polydihydrosilane (SiH 2 ) n into amorphous silicon first and then crystalline silicon material. Specifically, Si 6 H 12 can be transformed into solid polydihydrosilane (SiH 2 ) n by thermal treatment or light activation via radical polymerization. Additional thermolysis causes evolution of H 2 (g) giving a-Si:H at approximately 350° C. and crystalline silicon at approximately 850° C.
[0054] In another preferred embodiment, the liquid silane is cyclopentasilane, cyclohexasilane and/or 1-silylcyclopentasilane corresponding to Si n H 2n where n=5 or 6.
[0055] The preferred polymer is poly(methyl methacrylate). However, a polycarbonate such as polypropylene carbonate/polycyclohexene carbonate or poly(vinylidene fluoride-co-hexafluoropropylene) and polyvinyl butryal may also be used in the embodiment shown at block 12 of FIG. 1 .
[0056] In one embodiment, the percentage of silane to organic polymer in the viscous solution is kept within the range of approximately 5% to 20% silane, with the range of 10% to 16% silane preferred.
[0057] The preferred accelerant that is part of the composition at block 12 is a polyhydropolysilane. A wide variety of polyhydropolysilanes act as accelerants for the polymerization of cyclohexasilane, Si 6 H 12 (CHS). Polyhydropolysilanes with linear, branched, and cyclic structures have been shown to accelerate the polymerization of CHS when one or more of these compounds are added to CHS and the resulting mixture is exposed to energy from thermal, electromagnetic, or mechanical sources. There is a significant advantage to the use of polyhydropolysilanes as “promoters” or “accelerants” to the polymerization, or film forming process. Since they are composed of only Si and H, they are therefore completely compatible with the product material. Accelerants are usually distinctly different from the materials they accelerate and thus become impurities in the final product(s).
[0058] For example, polyhydropolysilanes of formula Si n H n+2 , linear or branched, individually, or in combination, accelerate the polymerization of CHS when added to CHS. For example, linear and branched polyhydropolysilanes of formula Si n H n+2 , where n ranges from 2-10,000, when mixed with CHS, accelerates polymerization to form films that can be placed in a variety of devices that respond to light, e.g., solar cells.
[0059] Polyhydropolysilanes composed of one or more polyhydrocyclopolysilane rings attached to another polyhydrocyclopolysilane, with or without the presence of substituents on the ring, will accelerate the polymerization of CHS when added to CHS. Similarly, polyhydropolysilanes composed of one or more cyclopolysilane rings, with or without the presence of substituents on the ring, will accelerate the polymerization of CHS when added to CHS.
[0060] CPS (cyclopentasilane, Si 5 H 10 ), when mixed with CHS, will accelerate the polymerization of CHS when added to CHS. Derivatives of CPS with one or more silyl groups attached to the ring, when mixed with CHS, accelerate polymerization of CHS.
[0061] Silylcyclopentasilane also accelerates polymerization and film formation. This structure has the formula of Si 6 H 12 , but is comprised of a five membered ring of silicon atoms with the 6 th silicon attached to the ring.
[0062] Additionally, derivatives of CHS with one or more linear or branched silyl-groups attached to the ring, when mixed with CHS will accelerate polymerization. It was also observed that partially or fully halogenated silanes and polysilanes accelerate polymerization of CPS and CHS.
[0063] The preferred solvents at block 12 include toluene, xylene, cyclooctane, 1,2,4-trichlorobenzene, and dichloromethane or mixtures thereof. However, although these solvents are preferred, it will be understood that other solvents may be selected based on the polymers and the silanes that are employed.
[0064] At block 14 of FIG. 1 , the viscous solution that was produced at block 12 is expelled from a nozzle or drawn from a film and exposed to a high electric field and continuous fibers arising from the solution are formed and deposited onto a substrate.
[0065] In one embodiment of the method, the high-voltage environment is formed by applying a direct current bias from the point where the solution is expelled from a nozzle to the collecting substrate. The voltage used for the electrospinning process normally ranges from approximately 5000V to approximately 20,000V with approximately 7000V to 11,000V typically used. In a preferred embodiment, a direct current bias that is greater than approximately 2 kV is applied across a gap of 10 cm in a nitrogen environment.
[0066] The electrospinning apparatus can also have a nozzle with an inner annulus and an outer annulus. In this configuration, liquid silane is expelled through the inner annulus of a coaxial delivery tube while viscous polymer solution is expelled through the outer annulus and both fluids are exposed to a high electric field resulting in the continuous formation of fibers that are deposited onto a substrate.
[0067] In one preferred configuration, the liquid silane that is directed through the inner annulus is Si 6 H 12 cyclohexasilane, Si 6 H 12 , 1-silyl-cyclopentasilane or Si 5 H 10 cyclopentasilane and the solution flowing through the outer annulus is polyacrylonitrile in dimethylformamide.
[0068] The strand of nanofiber material that is formed from solution expelled from the nozzle in a high electric field at block 14 is deposited and collected on a substrate at block 16 . In the embodiment shown in FIG. 1 , the substrate consists of a metallic foil such as copper foil or aluminum foil. In one configuration, the substrate includes conductive metallic portions and insulating portions and the silicon-containing wires that are produced span the insulating portions of the substrate. In another embodiment, the substrate is a conducting carbon fiber matte including a carbon fiber matte constructed of carbon nanotubes. The substrate may also be a rotating mandrel or a moving metal web of foil such as copper foil.
[0069] At block 18 of FIG. 1 the deposited and collected nanowires are transformed using thermal processing or laser processing. With cyclohexasilane based solutions, for example, the deposit can be transformed using thermal processing at temperatures ranging from approximately 150° C. to 300° C. to produce polysilane-containing materials. The deposit can also be transformed using thermal processing at temperatures ranging from about 300° C. to about 850° C., producing amorphous silicon-containing materials. The deposit from block 16 can be transformed using thermal processing at temperatures from approximately 850° C. to 1414° C. producing crystalline silicon-containing materials. As an illustration, the thermal treatment of cyclohexasilane and polymer solvent expelled through a coaxial nozzle consists of 350° C. under N 2 for one hour followed by 350° C. in air for one hour followed by 800° C. in N 2 for one hour. The deposit can also be transformed using laser processing to produce crystalline silicon-containing materials.
[0070] Optionally, at block 20 , the transformed fibers can be coated with a coherent, conductive coating and the coated transformed fibers can be used as a component of composite materials such as an anode material for a lithium ion battery, for example.
[0071] In one embodiment, the conductive coating is deposited by chemical vapor deposition using argon/acetylene, hydrogen/methane or nitrogen/methane as precursor gases. In another embodiment, the coherent, conductive coating is deposited at block 20 by solution deposition. For example, the solution deposition may employ a dispersion of conducting carbon milled together with the silicon-containing fraction in solvent. The conductive carbon can be graphite, carbon black, graphene, or carbon nanotubes in this embodiment.
[0072] Referring now to FIG. 2 , the steps according to a preferred embodiment 100 of the present method for producing a silicon-based nanowire material using five-component liquid silane inks with an optional conductive coating is illustrated. Five-component inks, according to the invention, may have essentially the same components as the four-component inks described herein with the addition of a solid phase. The solid phase component may be a particulate, photoactive or a reactive compound. Processing of the five-component inks is typically the same as the processing of the four-component inks.
[0073] At block 110 , a viscous solution is formed by combining a liquid silane preferably of the formula Si n H 2n , a polymer, a solid phase, an accelerant and a solvent. As with the four-component inks, the components may be combined sequentially in any order or by pairs.
[0074] The preferred liquid silane has the formula Si n H 2n , where n=3, 4, 5, 6, 7 or 8. Linear and branched liquid silanes of the formula Si n H 2n+2 , where n=3, 4, 5, 6, 7 or 8 may also be used. Mixtures of one or more of these silanes may also be used.
[0075] The preferred polymer is poly(methyl methacrylate) or a polycarbonate in the embodiment shown at block 110 of FIG. 2 . The preferred solvents at block 110 of FIG. 2 include toluene, xylene, cyclooctane, 1,2,4-trichlorobenzene, and dichloromethane or mixtures thereof. However, although these polymers and solvents are preferred, it will be understood that other polymers and solvents may be selected based on the polymers, the solid phases and the silanes that are employed.
[0076] One or more solid phase components can be part of the ink mixture provided at block 110 of FIG. 2 . For example, the solid phase can comprise a plurality of metallic particles, preferably nanoscale particles, which may be spherical or have a high aspect ratio. In one embodiment, the metallic particles are made of a metal such as Al, Au, Ag, Cu, In—Sn—O, fluorine-doped tin oxide, or a metal alloy. In another embodiment, the particles may be made from graphite, carbon black, or graphene. The metallic particles may also be composed of wires or tubes of suitable dimensions such as carbon nanotubes or silicon nanowires.
[0077] In other embodiments, the solid phase component of the ink contains elements that are known to substitutionally-dope silicon such as boron, phosphorous, arsenic or antimony containing compounds. The solid phase component can also be semiconducting particles formed from materials such as carbon nanotubes, CdSe, CdTe, PbS, PbSe, ZnO or Si.
[0078] The solid phase component can also include polydihydrosilane —(SiH 2 ) n —, formed by UV-irradiation of Si n H 2n (n=5,6) corresponding to cyclopentasilane, cyclohexasilane and/or 1-silylcyclopentasilane.
[0079] In another embodiment, metal silicide wires are formed where the solid phase at block 110 of FIG. 2 comprises a metal reagent. Examples of solid phase metal reagents includes CaH 2 , CaBr 2 , Cp 2 Ti(CO) 2 , V(CO) 6 , Cr(CO) 6 , Cp 2 Cr, Mn 2 (CO) 10 , CpMn(CO) 3 , Fe 2 (CO) 9 , Co 2 (CO) 8 , CO 4 (CO) 12 , Cp 2 Co, Cp 2 Ni, Ni(COD) 2 , BaH 2 , [Ru(CO) 4 ] ∞ , Os 3 (CO) 12 , Ru 3 (CO) 12 , HFeCo 3 (CO) 12 , Co 2 (CO) 8 and H 2 FeRu 3 (CO) 13 . Metal reagents at block 110 may also be a liquid such as TiCl 4 or Fe(CO) 5 .
[0080] In another embodiment, the solid phase is a photoactive solid phase. For, example, the photoactive phase can be particulates of a carbon fullerene, carbon nanotubes, quantum dots of CdSe, PbS, Si or Ge, core-shell quantum dots of ZnSe/CdSe or Si/Ge.
[0081] At block 120 , the solution is ejected through a nozzle in a high electric field to form a substantially continuous nanofiber through an electrospinning process. Although expulsion of a single solution though a single nozzle is described in the embodiment of FIG. 2 , other solution and nozzle configurations can be used with the four and five-component inks. For example, a coaxial nozzle and dispenser system can be used that has an inner annulus and an outer annulus. The polymer, solid phase, and a solvent can be combined to form a viscous solution that is the source of fluid flowing through the outer annulus. The selected liquid silane and accelerant is a second source of fluid that is expressed through the inner annulus.
[0082] For example, the liquid silane flowing through the inner annulus is Si 6 H 12 cyclohexasilane, Si 6 H 12 1-silyl-cyclopentasilane or Si 5 H 10 cyclopentasilane and the solution flowing through the outer annulus is polyacrylonitrile in dimethylformamide and metal particulates or carbon nanotubes.
[0083] In another embodiment, a viscous mixture of a polymer and a solvent is produced and that mixture is ejected through the outer annulus of the nozzle while simultaneously ejecting a liquid silane through an inner annulus of the nozzle. The two streams are directed through a high electric field to form Core-Shell Fibers. The fibers are transformed to silicon wires with a carbon outer coating. Many other combinations are also possible with this coaxial nozzle configuration.
[0084] At block 130 of FIG. 2 , the nanofiber that is formed at block 120 from the electrospinning apparatus is deposited on a conductive substrate. The substrate at block 130 is preferably a metallic foil such as copper foil or aluminum foil. The substrate can also be a conducting carbon fiber matte including a carbon fiber matte constructed of carbon nanotubes. In one configuration, the substrate includes conductive metallic portions and insulating portions and the silicon-containing wires that are produced span the insulating portions of the substrate.
[0085] The produced fiber collected at block 130 can be transformed to amorphous silicon or crystalline silicon composites through thermal treatment or light activation via radical polymerization at block 140 . The deposited material can also be collected and transformed at a different time and location.
[0086] As with the four-component inks, the fibers produced from the five-component inks are typically transformed using thermal processing at temperatures from 150° C. to 300° C. to give polysilane-containing materials. The deposit can also be transformed using thermal processing at temperatures from 300° C. to 850° C. to produce amorphous silicon-containing materials. The deposit can also be transformed using thermal processing at temperatures from approximately 850° C. to 1414° C. giving crystalline silicon-containing materials. Some variation in these temperature ranges may be seen depending on the nature of the particular solid phase that is used in the ink. Finally, the deposit can be transformed using laser processing to give crystalline silicon-containing materials at block 140 .
[0087] An optional coherent, conductive coating may be applied to the transformed materials before or after the thermal treatments at block 150 of FIG. 2 . The coatings at block 150 can be applied by chemical vapor deposition using argon/acetylene, hydrogen/methane or nitrogen/methane as precursor gases. The coatings can also be applied by solution deposition using a dispersion of conducting carbon milled together with the silicon containing fraction and a solvent and graphite, C black, graphene, nanotubes or wires as a carbon source.
[0088] It can be seen that the coated or non-coated nanofibers or wires that are produced according to the invention can be used as components of other composite materials with further processing. This can be illustrated with the production of an electrically-conducting silicon-composite electrode with a four-component ink or a five-component ink. Referring also to FIG. 3 , a method 200 for producing an anode material according to the invention is schematically shown. At block 210 , nanofibers are produced by electrospinning four or five-component inks. The fibers are transformed at block 220 by thermal or laser processing. The processed fibers are coated with carbon at block 230 . The carbon coating can be applied with chemical vapor deposition or by solution deposition. Carbon coatings preferably include coatings of graphite, carbon black, graphene, or nanotubes or nanowires.
[0089] At block 240 the coated fibers are combined with an ion conducting binder to form the body of the electrode. The polymer binder may either be inherently lithium ion conducting, or may become lithium ion conducting by absorbing an electrolyte solution. The coated nanofibers are mixed with a binder to give a material structure that can be further sized and shaped. For example, the binder may include poly(vinylidene fluoride-co-hexafluoropropylene) or sodium carboxymethylcellulose. Some binders may be volatile and capable of being removed with additional thermal or laser treatments. Other binders may also be ion or electrically conductive or have a conductive filler such as a carbon particulate like KB carbon or graphite.
[0090] Electrodes with coated silicon fibers are resistant to cracking from the sizeable volume changes that occur during the lithiation and delithiation processes during cycling, for example. KB carbon is an elastic carbon and is capable of stretching and compressing during ordinary volume changes and is a preferred conductive binder or filler at block 240 .
[0091] In one embodiment, an electrode can be produced by: (a) combining a liquid silane of the formula Si n H 2n , with a polymer such as poly(methyl methacrylate), polycarbonate, poly(vinylidene fluoride-co-hexafluoropropylene), sodium carboxymethylcellulose or a mixture of polymers, an accelerant and a solvent to form a viscous solution; (b) exposing the viscous solution to a high electric field where continuous fibers are formed and deposited onto a metal foil substrate; (c) transforming the deposit into a material that contains a polysilane, an amorphous silicon and/or a crystalline silicon fraction by thermal treatment under inert gas at a temperature <400° C.; (d) forming a coherent, ion conductive coating on the external porosity of the silicon-containing fraction deposited by vapor or solution deposition; and (e) mixing the coated silicon nanofiber material with a binder of poly(vinylidene fluoride-co-hexafluoropropylene), sodium carboxymethylcellulose and/or KB carbon to form an electrode.
[0092] The invention may be better understood with reference to the accompanying examples, which are intended for purposes of illustration only and should not be construed as in any sense limiting the scope of the present invention as defined in the claims appended hereto.
Example 1
[0093] In order to demonstrate the functionality of the electrospinning methods with different formulations of liquid silane inks, a test reactor was constructed. All electrospinning processing and post-deposition treatments were performed inside inert nitrogen gas gloveboxes with active oxygen scrubbing unless otherwise specified. After appropriate ink formulation, ink solutions and/or mixtures were taken up into 1 mL HDPE syringes fitted with blunt-nosed 18 gauge stainless steel needles 2.5 cm in length. The ink-containing syringe and needle were placed into a syringe pump in horizontal position with a needle-to-substrate standoff distance of approximately 25 cm.
[0094] Metallic copper foil pieces (5 cm×5 cm×0.8 mm) were employed as the electrode substrate in the electrospinning process and were cleaned according to the following protocol: rinsing with approximately 5 mL isopropanol using a squirt bottle; rinsing with approximately 5 mL 1.5 M hydrochloric acid using a squirt bottle; rinsing with approximately 10 mL deionized water using a squirt bottle; and, drying with a stream of particulate-filtered high-purity nitrogen gas. These substrates were then introduced into an electrospinning process glovebox.
[0095] The substrates were then placed into deposition position by connecting the metallic foil to an acrylic backdrop using an alligator clip that also served to make electrical connection to the ground of the power supply. A high voltage source (Gamma High Voltage Research Inc. Model ES40P-12 W/DDPM) was connected with the positive terminal on the needle and the negative (ground) on the metallic substrate. The syringe pump (Cole Parmer model EW-74900-00) was set to a flow rate of 0.4-0.5 mL/h and allowed to run until the needle was primed with liquid. Once a droplet formed on the outside of the needle, the power source was adjusted to 15 kV. A collimated halogen light source was used to visualize the spinning solution/mixture. Immediately after the 15 kV was applied, spinning fibers were seen moving from the needle horizontally to the substrate. The ground plate and needle location were adjusted so that the fibers were deposited at the center of the foil.
[0096] Cyclosilanes such as Si 6 H 12 and Si 5 H 10 were prepared and distilled under reduced vacuum yielding 99+% pure colorless liquid (by 1 H NMR). The Si 5 H 10 was prepared by reacting Si 5 Cl 10 with LiAlH 4 and used without additional purification. Inert atmosphere gloveboxes and standard Schlenk techniques were used to preclude the oxidation of liquid silane. This is necessary because Si 6 H 12 and Si 5 H 10 are pyrophoric liquids that burn upon contact with air and are treated as an ignition source and handled in inert atmosphere. In addition, (SiH 2 ) n reacts slowly with air and moisture to give amorphous silica.
[0097] An three-component ink, Si 6 H 12 /PMMA in toluene, was first used to demonstrate the electrospinning methods and the thermolysis products without the accelerant were characterized as a baseline for comparison as shown in FIG. 4 . A solution of PMMA in toluene was prepared by adding 4.60 g of dry toluene to a flame-dried vial with 0.52 grams of PMMA (Aldrich P/N 182265-500G Lot#07227DH, MW=996,000) mixed via magnetic stirring. The mixture was heated to 75° C. to expedite dissolution of the polymer. Next, 500 μL of this PMMA/toluene solution was cooled to room temperature and 100 μL of Si 6 H 12 was added dropwise giving two colorless immiscible phases with one being rather viscous. After stirring for 15 minutes, the mixture appeared to be homogeneous with an apparent viscosity that was higher than either of the immiscible phases indicating the formation of a three-component microemulsion or a single-phase mixture. Electrospinning was realized as described above using a copper foil as the substrate. After electrospinning, a piece of the sample was cut off with a scissors and heat treated to approximately 350° C. for 30 minutes.
[0098] Samples of inks with a variety of potential accelerants were prepared at room temperature in an oxygen free atmosphere using syringe techniques following degassing of the individual compounds using 3 or more freeze-thaw cycles. Polymerization rates of various candidates were compared with the baseline.
Example 2
[0099] Electrospinning of a three-component ink, Si 6 H 12 /PMMA using the solvent dichloromethane (DCM), without the accelerant was conducted to demonstrate an alternative solvent and to characterize performance of the resulting material as an electrode. A solution of PMMA in DCM was prepared by adding 18.0 mL of dry DCM to a flame-dried vial with 2.681 g of PMMA mixed via magnetic stirring at 500 RPM for 3 h. Next, 8.220 g of this PMMA/DCM solution, 858 μL of DCM and 418 μL of Si 6 H 12 were added dropwise while magnetically stirring to give a mixture of two immiscible liquids. After stirring for 15 minutes, the mixture appeared to be homogeneous with an apparent viscosity that was higher than either of the immiscible phases indicating the formation of a three-component microemulsion or a single-phase mixture. Electrospinning was realized as described above using a copper foil as the substrate.
[0100] Immediately after electrospinning each 1 mL aliquot, the deposited wires were scraped off of the copper foil and placed inside a flame-dried vial. The vials containing the samples were then heated on a ceramic hotplate with an aluminum shroud to 550° C. with a ramp rate no slower than 16° C./minute, and held for 1 h. The microstructure of the heat-treated deposit was probed using high-resolution scanning electron microscope and shown to consist of porous wires and agglomerates with primary particle size ˜150 nm in diameter. Raman microscope characterization of the product confirmed the existence of amorphous silicon phase given the characteristic broad band at 485 cm −1 . The Raman laser could also transform the a-Si wires into crystalline Si as evidenced by a band at 516 cm −1 that was observed after the laser beam was focused to ˜100 kW/cm 2 .
[0101] Optical micrographs of the electrospun deposit subjected to the higher power density showed clear signs of melting and densification in the wire. An 80 mg sample of the heated sample was sent to Galbraith Laboratories (Knoxville, Tenn.) for ICP-OES and combustion analysis where duplicate analyses showed 83.6 wt % silicon and 6.6 wt % carbon.
[0102] The produced nanowire materials were then used to make anodes in electrochemical cells. Before assembly in pouch cells, the a-Si wires were exposed to air and loaded into a chemical vapor chamber where a thin conducting carbon layer ˜10 nm thick was deposited. Afterwards, the C-coated a-Si wires were moved into a second inert atmosphere argon-filled glove box (H 2 O and O 2 <1 ppm). Lithium metal/a-Si wire half-cells were fabricated using Celgard-2300 as the separator and 1 M LiPF 6 in ethylene carbonate:diethyl carbonate 1:1 as the electrolyte with a mass loading of 4 mg/cm 2 . Electrochemical testing was performed by cycling between 0.02 and 1.50 V at 100 mA/g using an Arbin model B2000 tester. Charge/discharge data for a half-cell comprised of lithium metal and chemical vapor deposition carbon-coated a-Si nanowires was obtained. Specific capacity data showed an initial capacity of 3400 mAh/g, a 2nd cycle capacity of 2693 mAh/g with a fade of 16.6% after 21 cycles.
Example 3
[0103] The product of a second three-component ink, Si 5 H 10 /PMMA in DCM, without the accelerant using a post deposit treatment of 550° C. for 60 minutes and laser exposure was characterized. A 10 wt % polymer solution was prepared by adding dried and nitrogen-sparged DCM into a flame-dried glass vial with PMMA dissolved by stirring for ˜12 h. At that time, 45 μL of Si 5 H 10 was added to the solution using a micropipette and this mixture was stirred for 10 minutes using a PTFE-coated magnetic stir bar. The copper foil substrate was cleaned and moved into the electrospinning glovebox before being mounted and connected to the apparatus. Electrospinning was performed with a 20 cm stand-off distance, a 12 kV excitation, 0.5 mL/h ink flow rate and a total solution volume of ˜75 μL was dispensed.
[0104] Post thermal treatment of the electrospun sample on copper foil was conducted in a nitrogen ambient (<1 ppm O 2 and H 2 O). The sample was placed on a room temperature ceramic hotplate, and covered with an aluminum heat shield to improve temperature uniformity. The hotplate was ramped to 550° C. no slower than 30° C./minute and held at nominally 550° C. for one hour after which time, the sample was removed from the hotplate and placed on a room temperature aluminum plate and allowed to quickly cool to ambient.
[0105] Optical micrographs of the electrospun collected sample depicted wires that were ˜1 μm in diameter. Raman characterization of these wires showed the existence of crystalline silicon after melting with the Raman laser.
Example 4
[0106] The product of a three-component ink Si 6 H 12 /QPAC100 in toluene, without the accelerant was characterized by two different post deposit treatments: heating at 350° C. for 20 minutes; or 355 nm laser exposure followed by heating at 350° C. for 20 minutes. The latter of these two processes is shown schematically in FIG. 5 .
[0107] A polymer solution was prepared by placing 1.06 g of dried toluene into a flame-dried vial and adding 120 mg QPAC100 while stirring with a PTFE-coated magnetic stir bar for 2.5 h at 500 rpm. At this time, 50 μL Si 6 H 12 was added via pipette and a slight immiscibility was noted. The mixture was stirred for ˜40 h yielding a homogeneous mixture. The copper foil substrate was cleaned and moved into the electrospinning glovebox before being mounted and connected to the apparatus. Prior to electrospinning, the substrate was heat treated for one minute at 350° C. to desorb any trace water. Electrospinning was performed with a 30 cm stand-off distance, 0.5 mL/h ink flow rate and a 10 kV excitation.
[0108] After spinning for one hour, the sample was removed and cut into pieces with one being subjected to thermal treatment at 350° C. for 20 minutes. Interestingly, no wire like deposit was noted by optical microscopy after this thermal treatment. Scanning electron microscopy characterization showed dark areas that originated from the electrospun deposits with Raman characterization indicating the presence of a-Si on the substrate.
[0109] A description of this phenomenon can be envisioned by consideration of the thermal properties of each of the constituents of this three-component ink. Firstly, Si 6 H 12 shows that evaporation begins at around 225° C. with some polymerization that gives 32.9% residual mass after heating to 350° C. Secondly, QPAC100 begins to thermalize around 150° C. with 50% mass loss observed at 270° C. and less than 1% residue at 350° C. Therefore, when the electrospun wire formed by the three-component Si 6 H 12 /QPAC100 ink without the accelerant was thermally-treated, the polymer component volatized prior to the formation of a structurally stable poly(dihydrosilane). As the Si 6 H 12 fraction was yet unpolymerized, nanosized Si films appeared as shadows of the original wires.
[0110] After spinning for one hour, the second sample was cut into pieces and one was placed in an air-tight container and transferred into a glovebox that contained a beam from a HIPPO laser (355 nm illumination, Spectra Physics Inc.). Variable laser powers of 500 mW, 1 W, 2 W, 3 W, and 4 W for 1 minute and also 500 mW and 4 W for 5 minutes transformed the Si 6 H 12 into polysilane as evidenced by the appearance of yellow/brown discolorations for incident areas of the Si 6 H 12 /QPAC100 deposit. After this photolysis step, the (SiH 2 ) n /QPAC100 sample was placed on a room temperature hotplate and heated to 341° C. for a total of 20 minutes. The a-Si wires that were formed were characterized by high-resolution scanning electron microscopy and shown to possess significant porosity. Raman characterization of the product confirmed the existence of amorphous silicon phase that was melted by focusing the Raman laser.
Example 5
[0111] The electrospun fibers of the ink PMMA/Si 6 H 12 /Co 2 (CO) 10 in DCM without an accelerant and the resulting thermolysis products were characterized. A solution of PMMA in toluene was prepared by adding 10.38 mL of dry toluene to a flame-dried vial with 980 mg of PMMA mixed via magnetic stirring. 50 mg of a cobalt/silicon solution and 1 mL of the PMMA/toluene solution were mixed in a 4 mL flame-dried vial. After stirring for 15 minutes, the mixture appeared to be homogeneous. Electrospinning was realized as described above using a copper foil as the substrate.
[0112] After electrospinning, a piece of the sample was cut off with a scissors and rapidly thermal annealed to ˜600° C. using an IR lamp. A piece of this sample was adhered to a glass slide with silver contacts which were deposited with a wood toothpick using fast-drying silver paint. Resistance across the two silver contacts was measured using a two-point method with the Agilent B1500A semiconductor analyzer using I-V analysis. Resistivity values were obtained by manually approximating the amount of wires which were connecting between the electrodes and approximating the length between the electrodes (2 mm) and approximating the wire diameter (3-4 μm). The resistance was measured and resistivity calculated to be 4×10 4 Ω-m.
[0113] The microstructure of the heat-treated wires was probed using a high resolution scanning electron microscope and shown to consist of wires with diameters from 1 to 3 μm. EDS mapping confirms the presence of cobalt and silicon within the wires. The non-polymer components of this four-component electrospinning ink (i.e., Si 6 H 12 and Co 2 (CO) 8 ) have previously been reported as reagents for forming silicon-cobalt films.
Example 6
[0114] Another ink, PMMA/Si 6 H 12 /CdSe in DCM, without an accelerant and its thermolysis products were characterized. A 10 wt % solution of PMMA in dried and nitrogen-sparged DCM was mixed for ˜12 h and then 0.931 g of this solution was added to a flame-dried glass vial. To that solution, 46 μL of Si 6 H 12 and 47 μL of CdSe quantum dots in toluene (Lumidot® 480 nm excitation, 5 mg/mL in toluene, Sigma Aldrich P/N662356) were stirred for 10 minutes using a Teflon-coated magnetic stir bar. Electrospinning employed a copper substrate and was performed as described above.
[0115] Post-deposition treatment of electrospun deposit was performed in a nitrogen ambient (<1 ppm O 2 and H 2 O). The sample was placed on a room temperature ceramic hotplate, and covered with an aluminum heat shield to improve temperature uniformity. The hotplate was ramped to 550° C. no slower than 30° C./minute and held at nominally 550° C. for one hour. Thereafter, the sample was removed from the hotplate and placed on a room temperature aluminum plate and allowed to quickly cool to ambient temperature. The sample was then analyzed by Raman spectroscopy and the characteristic peak for crystalline silicon was noted after treatment with the Raman laser as shown in FIG. 6 .
Example 7
[0116] A third ink, PMMA/Si 6 H 12 /Carbon Black in DCM, without an accelerant and its thermolysis products were characterized. A suspension of carbon black (Cabot Industries, Black Pearls 2000) was prepared by mixing 52 mg of the carbon black with 1 mL of dried and nitrogen-sparged DCM in a flame-dried glass vial and sonicated for 30 minutes.
[0117] In a second flame-dried glass vial was placed 0.963 g of a 10 wt % solution of PMMA in dried and nitrogen-sparged DCM was mixed for ˜12 h. To that solution, 48 μL of Si 6 H 12 and 12 mg of the dried sonicated carbon black suspension were stirred for 10 minutes using a Teflon-coated magnetic stir bar. Electrospinning employed a copper substrate and was performed as described previously.
[0118] Post-deposition treatment of the electrospun deposit was performed in a nitrogen ambient (<1 ppm O 2 and H 2 O) atmosphere. The sample was then placed on a room temperature ceramic hotplate, and covered with an aluminum heat shield to improve temperature uniformity. The hotplate was ramped to 550° C. no slower than 30° C./minute and held at nominally 550° C. for one hour after which time, the sample was removed from the hotplate and placed on a room temperature aluminum plate and allowed to quickly cool to ambient temperature. The sample was analyzed by Raman and the characteristic peak for crystalline silicon was noted after treatment with the Raman laser as shown in FIG. 6 .
Example 8
[0119] For comparison, a fourth ink, PMMA/Si 6 H 12 /graphite in DCM without an accelerant and its thermolysis products were characterized. A suspension of graphite (Asbury Carbon, grade 4934) was prepared by mixing 52 mg of the graphite with 1 mL of dried and nitrogen-sparged DCM in a flame-dried glass vial and sonicated for 30 minutes. A 10 wt % solution of PMMA in dried and nitrogen sparged DCM was mixed for ˜12 h and 0.942 g of this solution was added to a flame-dried glass vial. To that solution, 47 μL of Si 6 H 12 and 47 μL of the sonicated graphite suspension were stirred for 10 minutes using a Teflon-coated magnetic stir bar. Electrospinning employed a copper substrate and was performed as described above.
[0120] Post-deposition treatment of the electrospun deposit was performed in a nitrogen ambient (<1 ppm O 2 and H 2 O). The sample was placed on a room temperature ceramic hotplate, and covered with an aluminum heat shield to reduce temperature inhomogeneity. The hotplate was ramped to 550° C. no slower than 30° C./minute and held at nominally 550° C. for one hour after which time, the sample was removed from the hotplate and placed on a room temperature aluminum plate and allowed to quickly cool to ambient. The sample was analyzed by Raman and the characteristic peak for crystalline silicon was noted after treatment with the Raman laser as shown in FIG. 6 .
Example 9
[0121] The product of a fifth ink, PMMA/Si 6 H 12 /Ag in DCM without an accelerant was characterized for comparison. In this illustration, a suspension of silver nanoparticles (<100 nm diameter, Sigma Alrich P/N 576832) was prepared by mixing 35 mg of the silver nanopowder with 700 μL of dried and nitrogen-sparged DCM in a flame-dried glass vial and sonicated for 30 minutes. A 10 wt % solution of PMMA in dried and nitrogen-sparged DCM was mixed for ˜12 h at which time 0.923 g of this solution was added to a flame-dried glass vial. To that solution, 46 μL of Si 6 H 12 and 46 μL of the sonicated silver nanoparticle suspension were stirred for 10 minutes using a Teflon coated magnetic stir bar. Electrospinning employed a copper substrate and was performed as described above.
[0122] Post-deposition treatment of the electrospun deposit was performed in a nitrogen ambient (<1 ppm O 2 and H 2 O). The sample was placed on a room temperature ceramic hotplate, and covered with an aluminum heat shield to improve temperature uniformity. The hotplate was ramped to 550° C. no slower than 30° C./minute and held at nominally 550° C. for one hour after which time, the sample was removed from the hotplate and placed on a room temperature aluminum plate and allowed to quickly cool to ambient. The sample was analyzed by Raman and the characteristic peak for crystalline silicon was observed after treatment with the Raman laser as shown in FIG. 6 .
Example 10
[0123] A sixth ink, PMMA/Si 6 H 12 /AIP in DCM, without an accelerant was characterized to further demonstrate the breadth of the methods. A 10 wt % solution of PMMA in dried and nitrogen-sparged DCM was mixed for ˜12 h after which time 0.949 g of this solution was added to a flame-dried glass vial. To that solution, 47 μL of Si 6 H 12 and 47 μL of an amphiphilic invertible polymer (AIP) (synthesized from poly(ethylene glycol) (PEG) and aliphatic dicarboxylic acids) were stirred for 10 minutes using a Teflon coated magnetic stir bar. Electrospinning employed a copper substrate and was performed as described above.
[0124] Post-deposition treatment of electrospun deposit was performed in a nitrogen ambient (<1 ppm O 2 and H 2 O). The sample was placed on a room temperature ceramic hotplate, and covered with an aluminum heat shield to improve temperature uniformity. The hotplate was ramped to 550° C. no slower than 30° C./minute and held at nominally 550° C. for one hour after which time, the sample was removed from the hotplate and placed on a room temperature aluminum plate and allowed to quickly cool to ambient. The sample was analyzed by Raman and the characteristic peak for crystalline silicon was noted after treatment with the Raman laser as shown in FIG. 6 .
Example 11
[0125] The products of a seventh ink, PMMA/Si 6 H 12 /BBr 3 in DCM without an accelerant were also characterized. A 10 wt % solution of PMMA in dried and nitrogen-sparged DCM was mixed for ˜12 h and 0.931 g of this solution was added to a flame-dried glass vial. To that solution, 46 μL of Si 6 H 12 and 1.5 μL of BBr 3 (>99.99% pure, Sigma Aldrich P/N 230367) were added and stirred for 10 minutes using a Teflon-coated magnetic stir bar. Electrospinning employed a copper substrate and was performed as described above.
[0126] Post-deposition treatment of the electrospun deposit was performed in a nitrogen ambient (<1 ppm O 2 and H 2 O). The sample was placed on a room temperature ceramic hotplate, and covered with an aluminum heat shield to improve temperature uniformity. The hotplate was ramped to 550° C. no slower than 30° C./minute and held at nominally 550° C. for one hour after which time, the sample was removed from the hotplate and placed on a room temperature aluminum plate and allowed to quickly cool to ambient. The sample was analyzed by Raman and the characteristic peak for crystalline silicon was noted after treatment with the Raman laser as shown in FIG. 6 .
Example 12
[0127] The electrospin products of an eighth ink, PMMA/Si 6 H 12 /PBr 3 in DCM, without an accelerant were characterized for comparison. A 10 wt % solution of PMMA in dried and nitrogen-sparged DCM was mixed for ˜12 h at which time 1.522 g of this solution was added to a flame-dried glass vial. To that solution, 75 μL of Si 6 H 12 and 2.3 μL of PBr 3 (>99.99% pure, Sigma Aldrich P/N 288462) were stirred for 10 minutes using a Teflon coated magnetic stir bar. Electrospinning employed a copper substrate and was performed as described above.
[0128] Post-deposition treatment of the electrospun deposit was performed in a nitrogen ambient (<1 ppm O 2 and H 2 O). The sample was placed on a room temperature ceramic hotplate, and covered with an aluminum heat shield to improve temperature uniformity. The hotplate was ramped to 550° C. no slower than 30° C./minute and held at nominally 550° C. for one hour after which time, the sample was removed from the hotplate and placed on a room temperature aluminum plate and allowed to quickly cool to ambient. The sample was analyzed by Raman and the characteristic peak for crystalline silicon was noted after treatment with the Raman laser as shown in FIG. 6 .
Example 13
[0129] The products of a ninth ink, PMMA/Si 6 H 12 /CNTs in DCM without an accelerant were also characterized. A 10 wt % solution of PMMA in dried and nitrogen-sparged DCM was mixed for ˜12 h at which time 1.960 g of this solution was added to a flame-dried glass vial that contained 4.04 mg of carbon nanotubes (Sigma Aldrich P/N 704148). To that solution, 98 μL of Si 6 H 12 were added and stirred for 10 minutes using a Teflon coated magnetic stir bar. Electrospinning employed a copper substrate and was performed as described above.
[0130] Post-deposition treatment of the electrospun deposit was performed in a nitrogen ambient (<1 ppm O 2 and H 2 O). After spinning, the sample was cut into pieces and one was placed in an air-tight container and transferred into a glovebox that contained a beam from a HIPPO laser (355 nm illumination, Spectra Physics Inc.). A laser power of 750 mW with a 1 cm 2 spot size was used to scan across the entire sample at a rate of 5 mm/s. After this photolysis step, the (SiH 2 ) n /PMMA sample was placed on a room temperature hotplate and heated to 350° C. at a ramp rate of 50° C./10 minutes. The sample was analyzed by Raman and the characteristic peak for crystalline silicon, as well as the D and G bands of the carbon nanotubes were noted after treatment with the Raman laser.
Example 14
[0131] The spin coating of thin films using a Si 6 H 12 /PMMA in DCM ink was demonstrated and compared with nanofibers produced by a conventional nozzle. A 10 wt % solution of PMMA in dried and nitrogen-sparged DCM was mixed for ˜12 h at which time 0.862 g of this solution was transferred to a flame-dried glass vial. To that solution, 43 μL of Si 6 H 12 was added and then stirred for 10 minutes using a Teflon-coated magnetic stir bar. The solution volume was then doubled by diluting with additional DCM.
[0132] Fused silica and quartz (1 cm×1 cm×1 mm) were employed as substrate in the spin coating process and were cleaned according to the following protocol: Liquinox™ detergent cleaning by rubbing for 30 sec with a latex glove; rinsing in a stream of hot water for 15 seconds; rinsing with ˜10 mL deionized water using a squirt bottle; rinsing with ˜10 mL acetone using a squirt bottle; rinsing with ˜10 mL isopropanol using a squirt bottle; and, drying with the flame of a propane torch. For the spin-coating procedure, 30 μL of the Si 6 H 12 /PMMA sample was dispensed onto a quartz substrate while spinning at 3000 RPM and under UV irradiation from a Hg(Xe) arc lamp (Newport Corp, lamp model 66142, power density ˜50 mW/cm 2 ) with a dichroic mirror used to filter the infrared photons.
[0133] Thermal treatment of samples deposited on fused silica and quartz was conducted in a nitrogen ambient (<1 ppm O 2 and H 2 O). The samples were placed on a room temperature aluminum hotplate and covered with an aluminum heat shield to improve temperature uniformity. The hotplate was ramped to 350° C. at 250° C./h at which time the thermal treatment was quenched by removing the sample from the hotplate to an aluminum plate at ambient temperature. Raman characterization of these films showed the existence of crystalline silicon after melting with the Raman laser.
Example 15
[0134] Spin coating of thin films using a Si 6 H 12 /PMMA/Ag in DCM ink without an accelerant was conducted to illustrate fiber formation from a thin film for comparison with other fiber producing methods. A mixture of silver nanoparticles (<100 nm diameter, Sigma Alrich P/N 576832) was prepared by mixing 35 mg of the silver nanopowder with 700 μL of dried and nitrogen-sparged DCM in a flame-dried glass vial. The vial was placed in an ultrasonic bath and treated with sonics for 30 minutes. A 10 wt % solution of PMMA in dried and nitrogen-sparged DCM was mixed for ˜12 h at which time 0.923 g of this solution was transferred to a flame-dried glass vial. To this PMMA solution was added 46 μL of Si 6 H 12 and 46 μL of the sonicated Ag/DCM mixture and the entire contents were stirred for 10 minutes using a Teflon-coated magnetic stir bar. The solution volume was then doubled by diluting with additional DCM.
[0135] Fused silica and quartz substrates (1 cm×1 cm×1 mm) were cleaned as described above. Thin films were prepared by spun-coating as described above using 30 μL of the four-component ink (Si 6 H 12 /PMMA/Ag). After spin-coating, thermal treatment of samples deposited on fused silica and quartz was conducted in a nitrogen ambient (<1 ppm O 2 and H 2 O). The samples were placed on a room temperature aluminum hotplate and covered with an aluminum heat shield to improve temperature uniformity. The hotplate was ramped to 350° C. at 250° C./h at which time the thermal treatment was quenched by removing the sample from the hotplate to an aluminum plate at ambient temperature. Raman characterization of these films showed the existence of crystalline silicon after melting with the Raman laser.
Example 16
[0136] In some instances a liquid that serves as a solvent for the polymer may react with Si 6 H 12 . A coaxial electrospinning approach can be employed to circumvent the deleterious interaction of Si 6 H 12 with some solvents. The product formed by coaxial electrospinning where neat Si 6 H 12 and a poly(acrylonitrile) (PAN) in dimethylformamide (DMF) solution were expelled from the inner and outer tubes, respectively was heat treated to 350° C. in nitrogen ambient for one hour, in air at 350° C. for one hour, and in nitrogen at 800° C. for one hour.
[0137] The PAN in DMF solution was prepared by placing 2.465 g of dried DCM into a flame-dried vial and adding a total of 548 mg PAN while stirring with a PTFE-coated magnetic stir bar for 24 h at 500 rpm. A 7.62 cm×7.62 cm×0.762 mm copper foil substrate was cleaned as previously mentioned and moved into the electrospinning glovebox before being mounted and connected to the apparatus. Electrospinning was performed with a 20 cm stand-off distance, 0.5 mL/h flow rate of both the inner and outer fluids and a 10 to 19 kV excitation.
[0138] After spinning for one hour, the sample was removed and subjected to thermal treatment at 350° C. for one hour on a hotplate in nitrogen ambient (<1 ppm O 2 and H 2 O) with a ramp rate of 200° C./h, followed by tube furnace treatment in air at 350° C. for one hour and nitrogen ambient at 800° C. for one hour. Optical microscopy of the annealed coaxial electrospun sample confirms the presence of wire-like deposits with diameter ˜1 μm. Raman analysis of this same sample shows the presence of silicon, as evidenced by a ˜480 cm −1 and 520 cm −1 bands corresponding to a-Si and c-Si, respectively.
[0139] A description of this phenomenon can be envisioned by consideration of the thermal properties of each of the constituents of this three-component ink. Firstly, Si 6 H 12 shows that evaporation begins at around 225° C. with some polymerization that gives 32.9% residual mass after heating to 350° C. Secondly, PAN crosslinks around 350° C. in air and thermalizes to carbon around 800° C. in nitrogen. Therefore, when the coaxial electrospun wires formed from the three-component Si 6 H 12 /PAN ink were thermally-treated, the silicon component converts to a-Si and/or c-Si and the polymer component carbonizes to form structurally stable and conductive carbon.
Example 17
[0140] Polyhydropolysilanes with linear, branched, and cyclic structures accelerate the polymerization of CHS when one or more of these compounds are added to CHS and the resulting mixture is exposed to energy from thermal, electromagnetic, or mechanical sources.
[0141] For example, polyhydropolysilanes of formula Si n H n+2 , linear or branched, individually, or in combination, have been shown to accelerate the polymerization of CHS when added to CHS.
[0142] Linear and branched polyhydropolysilanes of formula Si n H n+2 , where n ranges from 2-10,000, when mixed with CHS, accelerates polymerization to form films that can be placed in a variety of devices that respond to light, e.g., solar cells.
[0143] Polyhydropolysilanes composed of one or more polyhydrocyclopolysilane rings attached to another polyhydrocyclopolysilane, with or without substituent's on the ring, were also been shown to accelerate the polymerization of CHS when added to CHS.
[0144] Polyhydropolysilanes composed of one or more cyclopolysilane rings, with or without substituents on the ring, will also accelerate the polymerization of CHS when added to CHS.
Example 18
[0145] Samples comprised of 1%-50% (by volume) of a linear silane such as Si 3 H 8 , dissolved in CHS showed accelerated polymerization rates of 10%-200% compared to polymerization of pure CHS when exposed to energy from thermal, electromagnetic, or mechanical sources.
Example 19
[0146] Samples comprised of 1%-50% (by volume) of a branched polysilane such as neopentasilane, (H 3 Si) 4 Si, dissolved in CHS showed accelerated polymerization rates of 10%-200% compared to polymerization of pure CHS when exposed to energy from thermal, electromagnetic, or mechanical
Example 20
[0147] CPS (cyclopentasilane, Si 8 H 10 ), when mixed with CHS, was shown to accelerate the polymerization of CHS when added to CHS. Samples comprised of 1% to 50% (by volume) CPS dissolved in CHS have accelerated polymerization rates of 10% to 200% compared to polymerization of pure CHS when exposed to light in the ultraviolet range or temperatures in excess of 80 deg C.
[0148] Derivatives of CPS with one or more silyl groups attached to the ring, when mixed with CHS, were also shown to accelerate polymerization of CHS. Experiments were also conducted on samples sizes of 10 mg to 10 g. It was discovered that H 3 Si—Si 5 H 9 , where the Si 5 H 9 represents a cyclopentasilane structure, absorbs light efficiently in the 200 nm to 210 nm range and that exposure of mixtures of this compound with CHS could be readily polymerized at these wavelengths. This observation is expected to be the same for all compounds containing five silicon atoms in a ring. Pure CHS and pure CPS do not have significant absorptions of light at wavelengths greater than 200 nm. The fact that the H 3 Si—Si 5 H 9 , where the Si 5 H 9 represents a cyclopentasilane structure, is responsive to lower energy light was unexpected. Therefore, CHS can be polymerized with lower energy light using these accelerants. These technologies represent potentially significant cost savings in the production of many silicon containing materials.
Example 21
[0149] Silylcyclopentasilane was shown to accelerate polymerization and film formation of CHS and other liquid silanes. This structure has the formula of Si 6 H 12 , but is comprised of a five membered ring of silicon atoms with the 6 th silicon attached to the ring. Samples comprised of 1% to 50% (by volume) of silylcyclopentasilane dissolved in CHS showed accelerated polymerization rates of 10% to 200% compared to polymerization of pure CHS when exposed to energy from thermal, electromagnetic, or mechanical sources. In one example, the addition of silylcyclopentasilane to CHS, allows more efficient absorption of wavelengths above 200 nm than a sample of pure CHS. The light used for this compound is of lower energy than is needed for both CPS and CHS.
Example 22
[0150] Additionally, derivatives of CHS with one or more linear or branched silyl groups attached to the ring, when mixed with CHS, accelerate polymerization of CHS. It was also observed that partially or fully halogenated silanes and polysilanes accelerate polymerization of CPS and CHS.
[0151] It can be seen that many different novel four-component or five-component inks can be devised to commercially produce silicon based nanowires and similar materials in electrospinning reactors, and the accelerants can be selected to accelerate polymerization and reduce the energy input necessary to produce the silicon based materials.
[0152] From the discussion above it will be appreciated that the invention can be embodied in various ways, including the following:
[0153] 1. A method for synthesizing silicon nanofibers, comprising combining a liquid silane, a polymer, an accelerant and a solvent to form a viscous solution, passing a stream of viscous solution through a high electric field to form fibers, depositing the formed fibers onto a substrate, and transforming the deposited fibers into a silicon nanostructure.
[0154] 2. A method for synthesizing silicon nanofibers, comprising: combining a liquid silane, a polymer, an accelerant, a solid phase and a solvent to form a viscous solution, passing a stream of viscous solution through a high electric field to form fibers, depositing the formed fibers onto a substrate, and transforming the deposited fibers into an silicon nanostructure.
[0155] 3. The method as recited in embodiment 1 or 2, wherein the accelerant comprises cyclopentasilane and the liquid silane comprises cyclohexasilane.
[0156] 4. The method as recited in embodiment 1 or 2, wherein the accelerant comprises a Si substituted cyclopentasilane of the formula H 3 Si—Si 5 H 9 (n-silylcyclopentasilane).
[0157] 5. The method as recited in any of the proceeding embodiments, wherein the transformation of the deposited fibers comprises exposure of the formed fibers to light with a wavelength within the range of 200 nm to 210 nm.
[0158] 6. The method as recited in embodiment 1 or 2, wherein the accelerant comprises a polyhydropolysilane of formula Si n H n+2 where n ranges from 2-10,000.
[0159] 7. The method as recited in embodiment 1 or 2, wherein the accelerant is selected from the group of accelerants consisting of: a linear silane of formula Si 3 H 8 , a cyclohexasilane derivative with one or more linear or branched silyl groups attached to the ring, a halogenated silane, a polyhydrocyclopolysilane ring attached to another polyhydrocyclopolysilane and neopentasilane of formula (H 3 Si) 4 Si.
[0160] 8. The method as recited in any of the preceding embodiments, wherein the polymer is selected from the group of polymers consisting essentially of poly(methyl methacrylate), polycarbonate, poly(vinylidene fluoride-co-hexafluoropropylene), and polyvinyl butryal.
[0161] 9. The method as recited in any of the preceding embodiments, wherein the solvent is selected from the group of solvents consisting essentially of toluene, xylene, cyclooctane, 1,2,4-trichlorobenzene, dichloromethane or mixtures thereof.
[0162] 10. The method as recited in any of the preceding embodiments, further comprising coating the transformed fibers with a coherent, conductive coating selected from the group of coatings consisting essentially of graphite, carbon black, KB Carbon, carbon nanotubes and graphene.
[0163] 11. An electrospinning ink composition, comprising a liquid silane of the formula Si n H 2n , an accelerant, a polymer, and a solvent.
[0164] 12. An electrospinning ink composition, comprising: a liquid silane of the formula Si n H 2n , an accelerant, a polymer, a solid phase, and a solvent.
[0165] 13. The ink composition as recited in embodiment 11 or 12, wherein the liquid silane comprises a liquid silane is a cyclosilane selected from the group of cyclosilanes consisting essentially of cyclopentasilane, cyclohexasilane and 1-silylcyclopentasilane.
[0166] 14. The ink composition as recited in any of the preceding embodiments, wherein the liquid silane comprises a liquid silane of the formula Si n H 2n+2 .
[0167] 15. The ink composition as recited in embodiment 11 or 12, wherein the accelerant comprises cyclopentasilane.
[0168] 16. The ink composition as recited in embodiment 11 or 12, wherein the accelerant comprises a Si substituted cyclopentasilane of the formula H 3 Si—Si 5 H 9 (n-silylcyclopentasilane).
[0169] 17. The ink composition as recited in embodiment 11 or 12, wherein the accelerant comprises a polyhydropolysilane of formula Si n H n+2 where n ranges from 2-10,000.
[0170] 18. The ink composition as recited in embodiment 11 or 12, wherein the accelerant is selected from the group of accelerants consisting of: a linear silane of formula Si 3 H 8 , a cyclohexasilane derivative with one or more linear or branched silyl groups attached to the ring, a halogenated silane, a polyhydrocyclopolysilane ring attached to another polyhydrocyclopolysilane and neopentasilane of formula (H 3 Si) 4 Si.
[0171] 19. The ink composition as recited in embodiment 12, wherein the solid phase is a metallic particle selected from the group of metal particles consisting essentially of metallic particles of Al, Au, Ag, Cu, In—Sn—O, fluorine-doped tin oxide and carbon black.
[0172] 20. The ink composition as recited in embodiment 12, wherein the solid phase is a semiconducting particle selected from the group of semiconducting particles consisting essentially of carbon nanotubes, silicon nanowires, polydihydrosilane (Si n H 2 ) n , CdSe, CdTe, PbS, PbSe, ZnO and Si.
[0173] 21. The ink composition as recited in embodiment 12, wherein the solid phase is a metal reagent selected from the group of metal reagents consisting essentially of CaH 2 , CaBr 2 , Cp 2 Ti(CO) 2 , TiCl 4 , V(CO) 6 , Cr(CO) 6 , Cp 2 Cr, Mn 2 (CO) 10 , CpMn(CO) 3 , Fe(CO) 5 , Fe 2 (CO) 9 , Co 2 (CO) 8 , CO 4 (CO) 12 , Cp 2 Co, Cp 2 Ni, Ni(COD) 2 , BaH 2 , [Ru(CO) 4 ] ∞ , Os 3 (CO) 12 , Ru 3 (CO) 12 , HFeCo 3 (CO) 12 , and H 2 FeRu 3 (CO) 13 .
[0174] 22. An ink composition as recited in embodiment 12, wherein the solid phase is a photoactive particle selected from the group of photoactive particles consisting essentially of a carbon fullerene, a quantum dot of CdSe, PbS, Si or Ge, and a core-shell quantum dot of ZnSe/CdSe or Si/Ge.
[0175] Although the description above contains many details, these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the presently preferred embodiments of this invention. Therefore, it will be appreciated that the scope of the present invention fully encompasses other embodiments which may become obvious to those skilled in the art, and that the scope of the present invention is accordingly to be limited by nothing other than the appended claims, in which reference to an element in the singular is not intended to mean “one and only one” unless explicitly so stated, but rather “one or more.” All structural, chemical, and functional equivalents to the elements of the above-described preferred embodiment that are known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the present claims. Moreover, it is not necessary for a device or method to address each and every problem sought to be solved by the present invention, for it to be encompassed by the present claims. Furthermore, no element, component, or method step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is explicitly recited in the claims. No claim element herein is to be construed under the provisions of 35 U.S.C. 112, sixth paragraph, unless the element is expressly recited using the phrase “means for.” | Described herein are synthesis schemes and methods for producing silicon based nanostructures and materials, including compositions and methods for synthesis of silicon-based nanowires and composites from four-component inks of a liquid silane, a polymer, an accelerant and a solvent, or from five-component inks of a liquid silane, a polymer, an accelerant, a solid phase and a solvent. The methods can be used for producing silicon based microfibers and nanofibers that can be used in a variety of applications including material composites, electronic devices, sensors, photodetectors, batteries, ultracapacitors, and photosensitive substrates. | big_patent |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is directed to an arrangement for the control of thread tension in a spool creel having several spool holders each provided with a brake rotor working with a braking element that is adjustable by a tensioning lever carrying a roller; wherein the roller and lever is biased by the departing thread to take up an angular position dependent upon thread tension and net weight.
Such arrangements which are presently in the marketplace have the advantage that the force exercised by the braking band automatically decreases as the wind diameter of each spool is reduced. The weight distribution on the tensioning lever is predetermined and thus also the thread tension exercised by the creel spools on the threads.
2. Description of Related Art
The creel arrangements presently on the marketplace (compare for example, DE OS 19 18 161) have the advantage that the braking force exercised by the braking arrangement is automatically decreased when the wind diameter on the spools is reduced. The weight distribution on the tensioning level is predetermined and thus also the thread tension exercised upon the threads taken from the creel.
From DE PS 88 3 727, it is known to provide electromagnetic brakes to all spool holders to drive all magnets in parallel switching and to alter the activation current by a common setting arrangement. In this way, the entire tension from the various creels can be changed during operation and, at switch-off, a rapid braking action can be obtained by raising the braking force. This gives rise however to a loss of individual control of the tension of the individual spools.
It is also known to provide pneumatic biasing arrangements to thread brakes (DE GM 80 25 217) in which the biasing for a plurality of thread brakes in a spool creel can be centrally set and controlled.
Swiss Patent 358 043 describes a thread brake in which a braking platelet acts upon the threads by means of a pneumatic cylinder piston assembly whose pressure is set from a central control point.
British Patent 1 071 190 discloses the provision of a brake shoe to a spool which under the influence of a pressure means, can be forced against a rotating braking surface.
SUMMARY OF THE INVENTION
An object of the present invention is providing an arrangement for the control of thread tension in a spool creel in which the thread tension for the entire array as well as for individual spool holders can be achieved.
In accordance with the illustrative embodiments demonstrating features and advantages of the present invention, there is provided an arrangement for controlling tension of threads in a spool creel having a plurality of spool holders. This arrangement has a plurality of controllers. These controllers are simultaneously settable by fluid pressure. Each of the controllers are coupled to a different corresponding one of the spool holders. Each of the controllers has a brake rotor and an adjustable, tension responsive, braking element coupled to the brake rotor. The arrangement also has a tensioning lever coupled to the braking element for biasing it. The tensioning lever has a roller adapted to engage and be biased by the threads. This tensioning lever is operable to occupy an angular position dependent upon thread tension and weight. Also included is a biasing arrangement adapted to be activated by fluid pressure and connected to the tensioning lever, each of the tension levers being simultaneously settable by the fluid pressure.
By employing such apparatus an improved tension control is achieved in a creel arrangement wherein each spool holder is provided with a fluid pressure sensitive biasing arrangement, which influences the tensioning lever and wherein the fluid pressure is controllable in common for all the biasing arrangements.
The force generated by the preferred biasing arrangement operates in addition to the weight force on the tensioning lever, whereby the thread tension is also altered. This change can be centrally set so that the thread tension can be determined for the entire creel.
When the warping machine served by the creel is shut off, the braking force throughout the entire creel can be increased so that a quick braking action is possible. Since the biasing arrangement operates by fluid pressure, it can influence the tensioning lever without hindering the swinging action of the tension lever necessary for the control procedure.
Preferably, the biasing arrangement is formed by a piston/cylinder assembly. Piston cylinder arrangements can, by maintenance of the fluid pressure, readily follow the swinging movement of the tensioning lever by changing their length. Also using a pneumatic drive at the same time prevents contamination of the threads by the pressurizing substance. Each spool holder need only be connected to a conduit providing the necessary pneumatic pressure.
Preferably, the tensioning lever in the total working area subtends an angle A to the horizontal plane of more than 45°. Also the working elevation angle of the biasing arrangement attached to the tensioning lever should preferably subtend an angle B of less than 45°. In particular, it is preferred that the angle A should be in the range of 60° to 80° and the angle B in the range of 30° to 40°. In this manner, the force component exercised by the biasing arrangement on the tensioning lever is substantially equal in the entire control range since the angle B is minimally altered.
In a preferred modification the biasing arrangement furthermore operates on a brake shoe, which is provided to a further rotating braking surface. This brake shoe is applied only under higher fluid pressures to a further braking surface, which can cause the braking to occur rather rapidly at the shut down of the warping machine.
Advantageously, the braking shoe can be held by the tensioning lever. This gives rise to a rather simple mode of construction with few additional parts. Furthermore, the tensioning lever ensures that the braking shoe on restart of the warping machine is removed from contact with the further braking surface and therefore no locking can occur.
The brake rotor may advantageously be a brake drum wherein the braking element is a braking band contactable therewith and tensionable by the tensioning lever.
In a preferred alternative, the brake rotor is a braking disc of electro-conductive material and the braking element is a magnetic system, which is displaceable by the tensioning lever into a position more or less covering the braking disc. In particular the magnetic system can comprise a permanent magnet adjacent one of a pair of legs straddling the braking disc.
BRIEF DESCRIPTION OF THE DRAWINGS
The above brief description as well as other objects, features and advantages of the present invention may be illustrated by the preferred embodiments as set forth in the drawings described below, wherein:
FIG. 1 is a schematic, side elevational view of two spool holders having a tension controlling arrangement, in accordance with principles of the present invention;
FIG. 2 is a plan view of the arrangement of FIG. 1;
FIG. 3 is a schematic view of an embodiment that is an alternate of the control arrangement shown in FIG. 1;
FIG. 4 is a plan view of the arrangement of FIG. 3; and
FIG. 5 is a sectional view of the magnetic system of the braking arrangement of FIG. 3.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A spool holder 1 is attached to the creel by socket 2. Mounted on holder 1 is a rotatable spool 3 wound with thread. In the operating example, a bolt 25 serves to connect spool 3 to the braking drum 4 to prevent relative rotation. Thus spool 3 is non-rotatably connected with braking drum 4, which has braking surfaces on an inside circumference and an outside circumference thereof.
A braking band 5 lies on the outer circumference of drum 4. Drum 4 and the equipment described hereinafter for controlling the braking band 5 are referred to as a controller. The braking band 5 is connected at one end to an immovable pin 6 and at the other end via spring 7 to the fixedly supported tensioning lever 8.
The threads 9 taken from the circumference of the spool 3 are first led over fixedly supported roller 10 and then looped around a further roller 11 which is attached to the free end of tensioning lever 8 and finally via eyelet 12 is led to an adjacent machine, for example, a warping machine.
The mass of the tensioning lever 8 in combination with the portions attached thereto exercise a clockwise turning moment thereon. A turning moment in the opposite direction is exercised by the tension of the thread 9. If the thread tension is too great, the tensioning lever moves from position B to position A, whereby the braking force exercised by the braking band 5 is diminished. The spool 3 can thus rotate more rapidly, which reduces thread tension so tensioning lever 8 again moves from position A toward the direction of position B. This eventually brings lever 8 to an equilibrium setting where the thread is taken off at exactly the desired tension.
A pneumatic biasing arrangement 13 is connected to tensioning lever 8. This comprises a fixedly supported cylinder 14 and a piston 15 (a piston and cylinder assembly) which is connected to the tensioning lever 8 by means of a hinge pin 16. While tensioning lever 8 is oriented at angle A (illustrated with the Greek reference character, alpha) of 60° to 80° from the horizontal, the biasing arrangement 13 is oriented at an angle B (illustrated with the Greek reference character, beta) of 30° to 40° from the horizontal in the thread direction.
Furthermore, hingedly attached to tensioning lever 8 via pin 29, is brake shoe 17 (shown in phantom), which operates in conjunction with a braking surface on the inner circumference of braking drum 4. When the tensioning lever 8 is swung beyond position B, an additional braking effect is brought into play, since pin 29 brings the braking shoe 17 into contact with the internal braking surface of drum 4.
One of two pressure means 18 and 19 (shown herein as plenums) can be selected via a switching valve 20 for connection to a conduit system 21. System 21 is operatively connected to all the biasing arrangements 13 in the entire creel. A pressure pump 22 pressurizes the first pressure means 18 by means of a pressure regulator 23 to a predetermined working magnitude of pressure. Second pressure means 19 is likewise pressurized through pressure regulator 24 to a predetermined braking magnitude of pressure. The working magnitude of pressure may lie, for example, in the order or magnitude of two bars in order to support the operation of the mass of tensioning lever 8. Thus when the working pressure of conduit system 21 is increased, the thread tension in the entire creel is raised.
By altering the working pressure by assistance of regulator 23, the thread tension can be adjusted as desired. The braking pressure may, for example, lie in the range of eight bar so that the braking shoe 17 remains in contact with the appropriate braking surface and thus a rapid braking of the spools on the creel can occur.
Switching valve system 30 has connecting sections 31 and 33 and blocking chamber 32, which does not permit passage of fluid. When the adjacent machine is operating, a signal is sent via input means 41 to make section 31 operative and connect pressure means 18 to conduit system 21. When the said machine is shut off, a signal is sent via input means 42 to make section 33 operative and connect pressure means 19 to conduit system 21, thus driving the major braking system of shoe 17 to the internal braking surface of drum 4.
There is also a plurality of further possibilities. The tensioning lever 8 can be biased by an additional weight (not shown). This weight can be changed. The weight can also be attached to another lever arm (not shown) angularly displaced relative to the tensioning lever.
The alternate embodiment of FIGS. 3 and 4 corresponds substantially to that illustrated in FIGS. 1 and 2. Identical parts have the same reference numbers throughout the Figures. FIG. 5 is a detailed schematic view of the magnetic system of FIGS. 3 and 4.
An important difference in this alternate embodiment is the replacement of the friction brake (braking band 5 of FIGS. 1 and 2) with an electromagnetic brake. For this purpose, tensioning lever 8 is rigidly connected with a transverse lever arm 26, which carries at its free end a magnetic system 27. This system 27 surrounds braking disc 28, which is attached to brake drum 4 and is made from electrically conductive material, suitably aluminum. When the tensioning lever 8 is swung, the brake disc 28 covers the braking system 27 more or less (see arrow 29).
The magnetic system 27 comprises a U-shaped carrier 30 with two legs 31 and 32. Leg 32 carries a permanent magnet 33. Lever arm 26 is shown in two settings. In the completely engaged setting (lined in full), system 27 exercises a stronger braking force, but in the retracted setting (lined in phantom), system 27 exercises a lesser braking force.
The magnetic system 27 brakes by generating eddy currents in braking disc 28. The more disc 28 is covered by system 27, the greater the braking effect. Also with this construction, by the activation of the biasing arrangements of all the braking arrangements the thread tension can be globally altered, while by pressing the brake shoe 17 to the brake drum 14 a rapid braking can be obtained. | The arrangement controls thread tension in a spool creel with a brake rotor (brake drum 4) for each spool holder (1). A braking element (brake band 5) operates therewith and is biasable by a tensioning lever (8) which takes an angular setting dependent upon the thread tension and the force of gravity. A fluid pressure activated biasing arrangement 13 influences the tensioning lever 8 at each spool holder 1. The fluid pressure is commonly adjustable for all of the biasing arrangements 13. In this manner a general changing of the thread tension can be combined with control of individual thread tension. | big_patent |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a sewing machine detector for detecting, for example, the position of a sewing needle and the speed of the sewing machine. The detector is integral with the drive and control elements of the sewing machine.
2. Description of the Background Art
FIG. 8 shows one conventional sewing machine drive system, as disclosed in Japanese Patent Disclosure Publication No. 38496 (1988), including a sewing machine 1, motor 2, belt 3 for the transmission of rotation, needle section 4, control circuit section 5 for the drive control of the motor 2, detector 6 and power indicating light 100.
FIG. 9 shows, in more detail, an optical fiber type needle position detector of the conventional apparatus disclosed in Japanese Patent Disclosure Publication No. 38496 (1988) which includes a detecting section 6a, an optical fiber cable 6b, a photoelectric translation processing module section 6c, and electrical connectors 6d, 7 for connecting the module section 6c and control circuit section 5.
FIGS. 10 and 11 show, in more detail, the detecting section 6a of the conventional needle position detector shown in FIGS. 9 and 10, including a sewing machine shaft 10, a shaft 11 of the detecting section 6a rotated in engagement with the sewing machine shaft 10, and needle UP position and needle DOWN position detecting reflective discs 12, 13 installed on the shaft 11 for reflecting light from a needle UP position detecting optical fiber 14 and a needle DOWN position detecting optical fiber 15, respectively. FIG. 11 shows a reflecting portion 13a of the reflective disc 13, an optical fiber supporter 16, a light sending optical fiber 15a provided in correspondence with the reflecting portion 13a of the needle DOWN position detecting reflective disc 13, and a light receiving optical fiber 15b provided in correspondence with the reflecting portion 13a of the needle DOWN position detecting reflective disc 13. Though not shown in FIG. 11 (See FIG. 12), a light sending optical fiber 14a and light receiving optical fiber 14b, in correspondence with the reflecting area of the needle UP position detecting reflective disc 12, are also provided and perform the same functions as described above with respect to the light sending optical fiber 15a and light receiving optical fiber 15b.
FIG. 12 shows a module section 6c of the needle position detector including light emitting devices 20, light receiving devices 21, a light sending optical fiber 14a for needle UP position detection, a light receiving optical fiber 14b for needle UP position detection, a light sending optical fiber 15a for needle DOWN position detection, a light receiving optical fiber 15b for needle DOWN position detection, an enclosure 22 of the module section 6c, a circuit board 23 with light emitting devices 20 mounted thereon, electronic components 24 for a signal processing circuit, a circuit board 25 on which electronic components 24 are mounted, and a connector 6d for electrical connection to a control circuit section 5.
The operation of the detector will be described next. First, prior to initiating operation, the positional relationships between the UP and DOWN positions of the sewing machine needle and detector reflective discs 12, 13 must be adjusted and fixed. During operation, power is supplied from the control circuit section 5 via the connectors 7, 6d, and light which has been photoelectrically-translated by the light emitting devices 20 in the module section 6c enters the light sending optical fiber 14a or 15a, reaches the light radiating portion of the detecting section 6a via the optical fiber cable 6b, is reflected by the reflecting portion 12a of the reflective disc 12 or the reflecting portion 13a of the reflective disc 13, is received by the light receiving optical fiber 14b or 15b, returns to the module section 6c again, is photoelectrically-translated by the light receiving devices 21, is waveform-processed by the signal processing circuit 24, passes through the connectors 6d and 7 as an electrical signal, and is transmitted to the control circuit section 5 as a needle UP position or needle DOWN position signal for controlling the sewing machine.
In the conventional detector 6, the optical fibers 14, 15 act to both send and receive light to and from the detecting section 6a mounted in engagement with the sewing machine shaft 10 and including the reflective discs 12, 13 for indicating a sewing machine needle position, i.e., the optical fibers 14, 15 are employed solely for purposes of detection. The photoelectric translation processing module section 6c connected to the control circuit section 5 includes electronic parts, such as the light emitting and receiving devices 20, 21 and signal processing circuit 24, while the detecting section 6a and module section 6c are connected by optical fibers 14, 15 housed in an optical fiber cable 6b. With the conventional arrangement, as described above, the influence of static noise due to the friction of a fabric to be sewn as well as other noise is eliminated. Malfunction is thereby avoided and stable sewing machine operations can be performed.
In the conventional detector, as described above, light 13, sent through the light sending optical fibers 14a or 15a, is reflected by the reflecting portion of the reflective discs 12 or 13 secured to the shaft 11 and is received through the light receiving optical fibers 14b or 15b. However, the reflective discs 12, 13 must withstand constant vibration during the operation of the sewing machine 1. Furthermore, if the bearings supporting the shaft 11 are worn, the shaft 11 vibrates to an even greater extent, causing the optical axes between the optical fibers 14, 15 and the reflecting portions of the reflective discs 12, 13 to change, resulting in an inability to receive predetermined signals.
Also, since the reflecting portions of the reflective discs 12, 13 are curved, they are difficult and expensive to machine.
Further, the rotary reflective discs 12, 13 employed as components for signal detection make the detecting section 6a relatively thick and non-compact.
Further, in the conventional detector, since the light sending optical fibers 14a, 15a and light receiving optical fibers 14b, 15b must be flexed, as shown in FIG. 11, in consideration of the curvatures of the reflective discs 12, 13, significant stress is imposed on the optical fibers 14, 15.
Due to the elasticity of the optical fibers 14, 15, and depending on the degree of curvature of the fibers, there may be a relatively large internal force directing the fibers 14, 15 to return to their original, straight line status, which internal force, as noted above, results in a significant stress in the fibers 14, 15 in the area where the fibers 14, 15 are inserted into the optical fiber supporter. Thus, in combination with the above-mentioned vibration, there is a significant possibility that the optical fiber supporter 16 may fracture.
Furthermore, when the curvature radius is large, the light transmitting percentage of the optical fibers 14, 15 decreases, and the efficiency deteriorates. Consequently, expensive optical fibers are necessary to prevent the above described problems.
The conventional apparatus as shown in FIG. 8 also includes a power indicating light 100 having a light emitting diode and lead wires run through cable 6b to turn on the light emitting diode. As noted above, the optical fibers are only employed for detection purposes. By way of contrast, power is supplied by the control circuit section 5 through regular lead wires run through cable 6b to the power indicating light 100.
Industrial sewing machines are often used in areas where high frequency welders are used, e.g., to seal raincoats, tents, etc. However, since high frequency welders generate high frequency electromagnetic waves of about 27 Mhz to 42 Mhz with outputs of several KW to several tens of KW, the lead wires in cable 6b for the power indicating light 100 can act as antennas thereby receiving the electromagnetic waves and generating an electromotive force. This electromotive force is highly undesirable as it affects the control device 5 and may cause the control device 5 to operate erroneously.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to overcome the above described disadvantages with respect to conventional apparatus by providing a low-price detector for a sewing machine which detector is durable despite the detrimental effects of vibration and which includes a thinner and more compact detecting section.
Another object of the present invention is to provide a detector for a sewing machine which minimizes stress imposed on the optical fibers by minimizing the curvature of the optical fibers.
Another object is to provide a power indicating light which does not electrically interfere with the operation of the detector and controller.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of a detector for a sewing machine according to a preferred embodiment of the present invention.
FIG. 2 is a sectional view taken along the plane A--A of FIG. 1.
FIG. 3 is a side view of an optical fiber supporter in the sewing machine detector according to the preferred embodiment of the present invention.
FIG. 4 is a front sectional view of a module section in the sewing machine detector according to the preferred embodiment of the present invention.
FIG. 5 is a side sectional view of the module section in the sewing machine detector according to the preferred embodiment of the present invention.
FIG. 6 is a side view of a first light shielding disc in the sewing machine detector according to the preferred embodiment of the present invention.
FIG. 7 is a side view of a second light shielding disc in the sewing machine detector according to the preferred embodiment of the present invention.
FIG. 8 is an overall view showing the arrangement of a conventional sewing machine.
FIG. 9 is a front view of the conventional sewing machine detector shown in FIG. 8.
FIG. 10 is a front sectional view of the detecting section of the conventional sewing machine detector shown in FIGS. 8-9.
FIG. 11 is a side sectional view of the same detecting section shown in FIG. 10.
FIG. 12 is a sectional view of a module section of the conventional sewing machine detector shown in FIGS. 8-9.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A preferred embodiment of the present invention will now be described with reference to FIGS. 1-7. Flat, sheet-shaped first, second and third light shielding discs 26a, 26b and 26c, respectively, are mounted coaxially to a shaft 11 connected to a sewing machine shaft 10.
The first light shielding disc 26a detects the sewing machine speed and a needle UP position, its base material being formed from a light-transmitting synthetic resin. A speed detecting light shielding area 27, needle UP position detecting light shielding area 28, angle setting scale 29 and angle indication 30 are printed, for example, in black on the surface of the base material (FIG. 6), the shaft 11 being secured at a shaft-through hole formed in the center of the disc 26a. The angle indication is provided as one tenth of the actual angle, i.e. 340° is indicated as 34°.
The second light shielding disc 26b is designed to detect a needle DOWN position, and its base material is also made of light-transmitting synthetic resin. A needle DOWN position detecting light shielding area 31 and an indicator arrow 32 for indicating an angle are printed on the surface of the base material, in a color different from that on the first light shielding disc 26a (e.g. red). Also, the outer circumference of the second light shielding disc 26b is provided with projections 33 such that the second light shielding disc 26b may be easily rotated with respect to the first disc 26a, the second disc 26b being free to rotate relative to the shaft 11 via a shaft-through hole formed in the center of the disc 26b.
Though not shown, the base material of the third light shielding disc 26c is also made of light-transmitting synthetic resin as in the first and second light shielding discs 26a and 26b. A thread trimmer timing position detecting light shielding area 34 (FIG. 1) is provided on the surface of the base material and an indicator arrow for indicating an angle is also printed on the base material in a color different from that on the first and second light shielding discs 26a and 26b (e.g. blue). The outer circumference of the third light shielding disc 26c is provided with projections such that the disc 26c may be rotated with respect to discs 26a and 26b, the third disc 26c being free to rotate via a shaft-through hole formed in the center of the disc 26c through which the shaft 11 is inserted. When the second and third discs 26b and 26c are rotated to the proper settings, they are clamped in place by a clamp (not shown).
An optical fiber supporter 16, as shown in FIGS. 2 and 3, includes two optical fiber supporter pieces 16a and 16b of identical shape. The optical fiber supporter piece 16a is provided with linear optical fiber fixing holes 40a (FIG. 3) for locking the ends of the light sending optical fiber for UP position detection 14a, the light sending optical fiber for DOWN position detection 15a, the light sending optical fiber for sewing machine speed detection 35a, the light sending optical fiber for thread trimmer timing position detection 36a, and the power indicating optical fiber 37. Significantly, the fibers are not flexed when inserted in the fixing holes 40a. First reflecting portions 39a are provided opposite the end faces of the light sending optical fibers 14a, 15a, 35a and 36a, respectively. The first reflecting portions 39a are provided by plating or by attaching reflective plates having a reflecting portion.
The optical fiber supporter piece 16b is provided with linear optical fiber fixing holes 40b for locking the ends of the light receiving optical fiber for UP position detection 14b, the light receiving optical fiber for DOWN position detection 15b, the light receiving optical fiber for sewing machine speed detection 35b and the light receiving optical fiber for thread trimmer timing position detection 36b. Again, significantly, the fibers are not flexed when inserted in the fiber fixing holes 40b. Furthermore, second reflecting portions 39b are provided opposite to the end faces of the light receiving optical fibers 14b, 15b, 35b and 36b. The second reflecting portions 39b may be provided in an identical manner as described above with respect to the first reflecting portions 39a.
The optical fiber supporter 16 is fastened, as by a screw or the like, to the enclosure of the detecting section 6a such that the first reflecting portions 39a and second reflecting portions 39b are in opposition and such that the light shielding areas 27, 28, 31, 34 of the first to third light shielding discs 26a, 26b, 26c are disposed between the first and second reflecting portions 39a and 39b (see FIG. 2). Consequently, light transmitted from the light sending optical fibers 14a, 15a, 35a, 36a, and reflected by the first reflecting portions 39a, passes through the first to third light shielding discs 26a, 26b, 26c, is reflected by the second reflecting portions 39b, and enters the light receiving optical fibers 14b, 15b, 35b, 36b.
A power indicating window 38 is provided along a wall of the detecting section 6a so as to receive one end of the power indicating optical fiber 37. Also, a fixing block 41 is provided within the module section 6c for securing the light sending optical fibers 14a, 15a, 35a, 36a, 37 and the light receiving optical fibers 14b, 15b, 35b, 36b. A circuit board 23 (FIG. 5) is fixedly secured within the module section 6c to the light emitting devices 20 and the light receiving devices 21.
In the above described detector of the preferred embodiment, light is radiated from the light emitting devices 20 in the module section 6c (FIGS. 4, 5), passes through the light sending optical fibers 14a, 15a, 35a, 36a, 37 and is sent to the detecting section 6a. Light transmitted through the light sending optical fibers 14a, 15a, 35a, 36a is projected on the first reflecting portions 39a from the ends of the light sending optical fibers 14a, 15a, 35a, 36a and is reflected by the first reflecting portions 39a toward the first to third light shielding discs 26a, 26b, 26c. When the light shielding areas 27, 28, 31, 34 of the first to third light shielding discs 26a, 26b, 26c are in transmitting positions, light is transmitted through the first to third light shielding discs 26a, 26b, 26c and directed to the second reflecting portions 39b, then reflected by the second reflecting portions 39b to the light receiving optical fibers 14b, 15b, 35b, 36b. The light directed to the light receiving optical fibers 14b, 15b, 35b, 36b enters the light receiving devices 21 (FIG. 5), is photoelectrically-translated therein, and is output as an electrical signal (e.g., a low level signal) in a conventional manner.
By way of contrast, when the light shielding areas 27, 28, 31, 34 of the first to third light shielding discs 26a, 26b, 26c are in shielding positions, light is not transmitted through the first to third light shielding discs 26a, 26b, 26c, i.e., light does not reach the second reflecting portions 39b and is not directed to the light receiving optical fibers 14b, 15b, 35b, 36b. In this situation, the light (or its absence) is converted to an electrical signal (e.g., a high signal) by the light receiving devices 21.
Thus, a speed signal for detecting the speed of a sewing machine 1 can be detected by the speed detecting light shielding area 27; a sewing machine needle UP position by the needle UP position detecting light shielding area 28; a sewing machine needle DOWN position by the needle DOWN position detecting light shielding area 31; and a thread trimmer timing position by the thread trimmer timing position detecting light shielding area 34.
When the optical axes of the light sending optical fibers 14a, 15a, 35a, 36a and the light receiving optical fibers 14b, 15b, 35b, 36b are not precisely aligned, light does not reach the light receiving optical fibers 14b, 15b, 35b, 36b, even if the light shielding areas 27, 28, 31, 34 of the first to third light shielding discs 26a, 26b, 26c are in the transmitting positions. Consequently, only high level electrical signals are provided. In the preferred embodiment, however, the light sending optical fibers 14a, 15a, 35a, 36a, first reflecting portions 39a, second reflecting portions 39b and light receiving optical fibers 14b, 15b, 35b, 36b are integrally secured and fixed in position by the optical fiber supporter 16, thereby providing accurate optical axes and a constant and stable operation.
Also, in the preferred embodiment, light is radiated from the light emitting device 20 in the module section 6c in FIG. 5, through an additional power indicating optical fiber 37, to the power indicating window 38 for power indication. Since the power indicating optical fiber runs from the module section 6c all the way to the detecting section 6a, there is no interference or "noise" problem, as is the case in the conventional detector assembly including a regular lead wire.
First to third light shielding discs 26a, 26b, 26c are disposed coaxially, as shown in FIG. 2, the first light shielding disc 26a being unrotatably secured to the shaft 11, and the second and third light shielding discs 26b, 26c being rotatably mounted to the shaft 11 when clamps (not shown) are loosened. The second and third light shielding discs 26b, 26c are unclamped from the shaft 11 only during angle adjustment. In addition, the second and third light shielding discs 26b, 26c have indicator arrows printed thereon for indicating an angle of rotation. The indicator arrows are printed in different colors so that the discs 26a, 26b and 26c may be differentiated. Further, the outer circumferences of the second and third light shielding discs 26b, 26c are provided with projections for manually rotating the second and third light shielding discs 26b, 26c relative to the shaft 11 and the first disc 26a.
As noted above, the indicator arrows of the second and third light shielding discs 26b, 26c are printed in different colors to facilitate the reading of an angle as determined with reference to the angle setting scale 29 of the first light shielding disc 26a. Thus, by reading the angle indication 30 (one-tenth of the actual angle) printed on the first disc 26a, the angles of the needle UP signal, needle DOWN signal and thread trimmer timing are easily determined.
It should be noted that the light-transmitting base materials of the first to third light shielding discs 26a, 26b, 26c may, alternatively, be non-light-transmitting and include drilled portions where light is to be transmitted.
It should be noted that signals other than the four signals detected, i.e. needle UP position signal, needle DOWN position signal, speed detection signal and thread trimmer position detection signal, may also be detected, and that at least two or more of the signals may be detected simultaneously.
It should also be noted that the reflecting portions 39a, 39b, provided in two places in the first embodiment, may, alternatively, be provided in one place if the positions and reflecting angles of the reflecting portions are such that the ends of the optical fibers are supported linearly so as to reduce stress in the optical fibers.
The present invention, unlike the conventional apparatus having rotary reflective discs, is capable of stably detecting sewing machine control signals despite shaft vibration due to the excessive wear.
Also, since there is no need for curved reflecting portions on the reflective discs, the present invention is less expensive to manufacture and results in a thinner, more compact detecting section.
It should also be noted that the present detector significantly reduces stress imposed on the optical fibers since the fibers are supported linearly. Also, stationary reflecting portions enable optional and additional optical axes to be generated.
Also, the present invention provides for the easy generation, during assembly, of accurate optical axes, which accuracy is maintained for long periods of time.
The present invention also includes an optical fiber power indicating cable which does not interfere or adversely affect sewing machine control circuitry. Furthermore, the power indicating cable can be run simultaneously with the optical fibers for detection, thereby simplifying the construction. | A detector is provided for a sewing machine wherein light transmitting/shielding discs are mounted coaxially on a shaft of the sewing machine and sandwiched between light receiving and light transmitting optical fibers positioned along opposite side portions of the disc assembly and leading to a processing module section. The detector is able to detect a plurality of positional settings of the sewing machine as well as additional settings without imposing undue stress on the light transmitting optical fibers since the optical fibers remain linear. A power indicating light, connected to the processing module section via an optical fiber, ensures that there is minimal electrical interference with the operation of the detector. | big_patent |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention has as its object a process for the continuous production of viscose rayon yarns. More particularly it has as its object a simplified process for the continuous production of viscose rayon yarns having a high degree of whiteness (degree of white).
2. Prior Art
As is known, the continuous spinning of viscose rayon occurs through a rather complex series of treatments, which may advantageously take place while the yarn travels in a substantially helical path, viz. travels while it is wound onto rollers which are askew with respect to one another. A plurality of yarns may be concurrently treated on a single spinning machine, in this type of process, such as taught e.g. in a copending Italian application of the same applicant, No. 28324 A/78.
If the viscose rayon yarn which is obtained is to be used for textile purposes, it must have a certain degree of white, which can be measured by standard tests which will be discussed later. To this end the yarn, after having undergone coagulation in a coagulating bath, is typically subjected to setting, desulphurating, bleaching, finishing and various washings, besides a final drying. Desulphuration and bleaching are indispensable to obtain an adequate degree of white.
The art has sought for some time to improve this classic treatment, on the one hand by speeding it up, on the other by reducing the space take-up of the spinning machines, or in both ways. It has already been proposed to reduce the number of treatments by tolerating a lower degree of white, but the resulting yarn is only acceptable for some applications. The present invention solves the problem of simplifying the viscose rayon continuous spinning process, permitting accelerating it and/or reducing the space take-up of the spinning machines, without sacrificing an excellent degree of white, and, on the contrary, while obtaining a degree of white which is higher than that commonly accepted, and all this by extremely simple and economical means.
SUMMARY OF THE INVENTION
The process which is the object of the present invention comprises, in association, the following critical operations, which are carried out on a yarn that has already been partially coagulated and has been completely drawn (usually to a ratio of 1 to 1.57), which yarn preferably has already left the coagulating bath and has begun its substantially helical travel or other travel during which it is to undergo the final treatments:
1. completion of the coagulation, which at the exit from the coagulating bath corresponds to a coagulating index or "gamma index", as hereinafter defined, comprised between 15 and 25, until a final coagulation index not higher than 1 is obtained.
2. a treatment with water having a non alkaline pH--treatment which may be called "washing"--until the amounts of the following elements, which are retained on the yarn, have been reduced to the values hereinafter indicated: total sulphur, not more than 0.2%; sulphur bound as sulphides, not more than 0.02%; elemental sulphur, not more than 0.06% iron, not more than 40 ppm, preferably not more than 20 ppm; zinc, not more than 700 ppm, preferably not more than 500 ppm; lead, not more than 30 ppm, preferably not more than 10 ppm.
The completion of the coagulation may be effected in various ways:
(a) by the mere passing of time, without application of other reagents or liquors except those entrained by the yarn;
(b) by an acid treatment, e.g. in a sulphuric acid bath, which may contain zinc and/or sodium sulphates, e.g. at temperatures between 50° C. and 100° C.;
(c) by a succession of the aforesaid treatments--(a) and (b)--in two successive stages.
Other substitute or additional treatments may be carried out, such as treatments by means of baths having different acidities, the only essential condition being that the aforesaid coagulation index be attained.
After the treatment with water having a non alkaline pH, the yarn is such that, once it has been subjected to drying and possibly finishing, it will have a degree of white not lower than 45.
The degree of white (W) is measured by means of the Hunterlab apparatus by the Hunter method.
The coagulation index "γ" is defined and calculated as the number of moles of CS 2 per 100 anhydroglucosidic groups of the cellulose. A yarn having an index γ which lies between 0 and 1 is considered completely coagulated.
The process according to the invention therefore produces a finished yarn having a high degree of white, through the following processing stages: partial coagulation and drawing, completion of the coagulation, washing under the aforesaid conditions, drying, possibly finishing.
Other treatments for improving the degree of white are therefore not necessary, and actually the degree of white cannot be further improved in a significant manner. However the scope of the invention will not be exceeded if other auxiliary treatments are added to the aforesaid treatments.
The process is carried out preferably with spinning speeds, viz. yarn take-up speeds, not lower than 90 m/min.
Preferably the aforesaid washing is carried out at temperatures between 20° and 30° C. and for a period of time between 25 and 40 seconds. The completion of the coagulation is preferably effected in a period of time between 15 and 40 seconds.
Another aspect of the invention consists in the chemical composition of the wash water which permits washing under the specified conditions and with the results that have been set forth, and in the way of obtaining this wash water.
The water which is used should have a pH between 4.0 and 5.5.
Further, it should be free from cations in amounts higher than the following amounts: Ca 2+ 1.5 mg/l and Mg 2+ 1.0 mg/l.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
It has been found that a water having these characteristics, whenever it is not already available, which occurs only rarely, may be obtained by treating the water available from the industrial distribution network with weakly acid ion exchange resins. The treatment with resins is continued until the pH of the water reaches values between 4 and 5.5, preferably between 4 and 4.7.
An example of the invention will now be described for purely illustrative purposes.
A cellulose paste intended for dissolution, having a α-cellulose content of 92%, is mercerized in NaOH at 18% and is squeezed to a squeezing ratio of 1:2.8, so as to obtain an alkali cellulose having the following composition:
Cellulose: 32%
Total alkalinity expressed as NaOH: 15.7%
The alkali cellulose thus obtained is disintegrated and ripened until a polymerization degree of 350 of the cellulose therein contained is obtained. When the ripening has ended, the alkali cellulose is sulphurated with 30% of CS 2 , based on the cellulose contained therein. The xantate thus prepared is dissolved in a diluted NaOH solution so as to obtain a viscose having the following composition:
Cellulose: 8%
Total alkalinity expressed as NaOH: 6.0%
Total sulphur: 2%.
The viscose thus obtained is spun so as to produce a yarn having a count of 133 dtex, in a spinning bath at 45° C., having the following composition:
Sulphuric acid: 140 g/l
Zinc sulphate: 10 g/l
Sodium sulphate: 250 g/l.
The spinning process is carried into practice by means of a glass pipe within which the coagulated yarn travels in the same direction as the coagulating bath. The yarn is withdrawn from the bath and at the stage has a γ index of 18, and in the withdrawal stage it is drawn by friction against yarn guides to a ratio 1 to 1.5. At this point the yarn starts to travel in a substantially helical path on a device as described in the copending Italian patent application No. 22076 A/78 filed on Apr. 7, 1978, which essentially consists of a support and advancing structure, on which the yarn undergoes a series of chemical and physical treatments.
In the example which has been described, the yarn undergoes, in a first stage, a spontaneous synaeresis, and is then treated with a setting bath constituted by a 15 g/l H 2 SO 4 solution at 90° C., whereafter it is washed with water having a pH of 4.5 and a content of Ca and Mg ions respectively of 1.0 and 0.5 mg/l, is then treated with an emulsion of mineral oil, and is finally dryed and taken up on a ring twister.
The yarn which is obtained has the following mechanical characteristics:
Tenacity in the conditioned state--18 cN/tex
Elongation in the conditioned state--18%
Tenacity in the wet state--8.3 cN/tex
Elongation in the wet state--31%
The characteristics and the advantages of the invention will be better evidenced by Table 1, in which analytical data of yarns are tabulated. To show the criticality of the combination of operations according to the invention, comparison data have been obtained not from yarns treated with conventional processes--which require a greater number of operations and much longer times, therefore lower spinning speeds--but with yarns which have all undergone a partial coagulation in the bath and a completion of the coagulation, but have not undergone washing under the preferred conditions of the present invention. In the first column of the table the elements and the quantities which have been determined are indicated. Column 2 illustrates the analysis of the yarn after the completion of the coagulation. It is seen that the degree of white is 30, which if the normal washing and finishing treatments were carried out, would be the degree of white obtained on the finished yarn, requiring a separate bleaching operation in order to increase it.
Column 3 illustrates the characteristics of the yarn which after completion of the coagulation has been washed with distilled water having a pH of 7.0. It is seen that the degree of white has been improved somewhat, but still to an insufficient degree, in spite of the use of distilled water which is economically prohibitive.
Column 4 illustrates the characteristics of the yarn which, after the completion of the coagulation, has been treated with dehardened water having a pH of 8.2, and indicates the criticality of the pH values set forth according to the invention.
TABLE 1______________________________________ 1 2 3 4 5 6______________________________________Degree of white 30 40 35 49 52Total sulphur % 0.31 0.18 0.24 0.19 0.18Elementary 0.09 0.08 0.08 0.05 0.05Sulphur %Sulphur from 0.04 0.03 0.04 0.02 0.02sulphides %Sulphur from 0.18 0.07 0.12 0.12 0.11sulphates %Ashes % 0.50 0.07 0.36 0.09 0.09Zn, ppm 850 240 300 280 260Fe, ppm 25 7 10 8 5Pb, ppm 35 30 30 25 30______________________________________
Finally columns 5 and 6 show the data of two yarns treated by the process according to the invention, with water treated with weakly acid exchange resin having a pH of 4.6. It is seen that the degree of white is in both cases very high, respectively 49 and 52. The comparison of the analytical data leads one to believe that the determining factor is the reduction of the sulphur from sulphides. Actually said reduction is accompanied by an improvement of the degree of white, whereas the other analytical data do not seem to be correlated with the degree of white. However, the Applicants do not wish to be bound to any interpretation of the phenomenon on which the invention is based, and do not go beyond the experimental finding that a high degree of white is invariably obtained with a simplified, more rapid and more economical process, whenever the conditions of the invention are observed.
To show the advantages of the invention, a scheme is shown hereinafter in which the process according to the invention and the traditional process are compared, the starting viscose being the same and the final degree of white being the same. It is seen that the traditional process requires one to handle, separate and recover a higher number of treatment liquors, which implies an economical burden with respect to the process according to the invention.
In the following scheme treatments and characteristics of the yarn have been reported according to the traditional process (Column A) and according to the present invention (Column B).
__________________________________________________________________________ A B__________________________________________________________________________POSTCOAGULATION POSTCOAGULATION ##STR1## ##STR2## ##STR3## ##STR4## ##STR5## ##STR6##FINISHING - DRYING - TAKE-UP FINISHING - DRYING - TAKE-UP__________________________________________________________________________ A B__________________________________________________________________________ Degree of white 49 49 Total sulphur % 0.29 0.18 Elemental sulphur % 0.15 0.06 Sulphur from sulphides % 0.02 0.02 Sulphur from sulphates % 0.12 0.10 Ashes % 0.6 0.09 Zn ppm 330 280 Fe ppm 11 20 Pb ppm 15 19__________________________________________________________________________ | Process for the continuous production of viscose rayon yarns having a highegree of whiteness, comprising extruding a viscose solution into a coagulating bath, drawing and coagulating the extruded filaments, advancing said filaments in a substantially helical path while they undergo all the treatments required for the production of the finished yarn, which process is characterized by, after the exit of the filaments from the spinning bath, completion of the coagulation to a coagulation index not higher than 1 and a treatment with water having a non-alkaline pH. | big_patent |
RELATED CASES
This is a continuation-in-part of our patent application Ser. No. 594,455 filed Mar. 29, 1984 now abandoned.
BACKGROUND OF THE INVENTION
One of the problems encountered when bleaching pulp with oxygen is attempting to wash the pulp after the oxygen stage. The oxygen entrained in the pulp mat reduces the vacuum on the vacuum washer and mixes with the wash water to form foam which reduces the vacuum in the washer and prevents the chemicals and water from passing through the mat.
There have been a number of proposals for the deaerating the pulp before the washer. One proposal is to use a "Deculator" process which is described by Mac Gregor, "The Deaeration of Paper, Paperboard and Hardboard Stock by the Deculator Process," Appita, Vol. 22, No. 6, May 1969, pp. xvii-xxi. It is also described in Paper, Vol. 184, No. 11, 1975, Dec. 8, 1975, pp. 667-668 and in Jacobsson, "Complete Deaeration as a Basic Necessity: The Deculator System," Paper, Apr. 20, 1981, pp. 61-62, 64, and 67. The process involves the rapid acceleration and spraying of stock into a long 6 foot diameter stainless steel receiver where it is boiled under vacuum while being impinged against a suitable target surface. This system involves expensive equipment, including vacuum systems and vacuum vessels.
Another system is described in Sethy, U.S. Pat. No. 4,209,359 issued Jun. 24, 1980. In this system the slurry, usually containing no more that 3% by weight of fiber, is agitated by a radial flow impeller which imparts a substantially radial flow to the slurry. Several types of impeller are shown.
Other large degassing chambers are shown in Roymoulik, et al. U.S. Pat. No. 3,832,276 granted Aug. 27, 1974, and in Richter, U.S. Pat. No. 3,963,561 granted Jun. 15, 1976. These are large expensive systems utilizing large tanks which must be built to withstand pressure. The Richter patent describes a large pressure vessel.
SUMMARY OF THE INVENTION
The inventors decided that there was a need for a small deaeration tank which may be at either atmospheric pressure of under low pressure or vacuum and a system of operating this tank which would allow pulp which had been treated with oxygen to be deaerated before being washed. Preferably it would be the same diameter as an oxygen reactor so that it could be placed on top of the reactor and be supported by the reactor. It would have no moving parts, so there would be no need for motors to be mounted on or near the tank. A closed tank would allow steam or oxygen to be recovered.
They devised a system in which the deaerator is a small tank having an inlet pipe, an outlet, and a tangential swirl inducing inlet pipe. The locations and sizes of these elements provide optimum deaeration.
In the system the swirl inducing fluid is the filtrate from the washer after the oxygen bleach.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagramatic view of the oxygen reactor system from the inlet thick stock pump through the washer.
FIG. 2 is an isometric view of the deaeration tank.
FIG. 3 is a side plan view of the deaeration tank.
FIG. 4. is a top plan view of the deaeration tank.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The overall oxygen process is shown in diagramatic form in FIG. 1. In this process, the pulp is carried through line 10 into thick stock pump 11 where it is forced through line 12 to steam mixer 13. In the steam mixer 13 steam from line 14 is combined with the pulp and heats the pulp. The heated pulp is carried through line 15 to oxygen mixer 16.
The temperature of the pulp in line 15 is sensed by temperature sensor 17. The sensor 17 operates valve 18 which controls the flow of steam through line 14. In oxygen mixer 16 the pulp is mixed with oxygen from line 19. The amount of oxygen added to the pulp is controlled by valve 20.
The oxygenated pulp is carried through line 21 and isolation valve 22 into a tower 23. The tower shown is an open tower and the only pressure within the tower is the hydrostatic head. However, if desired it may be a closed pressure tower.
From the top of the tower the oxygenated pulp is carried through line 24, valve 25 and line 26 to the oxygen deaeration tank inlet 27. Valve 25 is the pressure control valve. Although the pulp is at a consistency of 8-15% and usually 11-14%, it flows easily to the system because of the oxygen within the pulp.
Inlet 27 carries the pulp into the deaeration tank 28. An emergency line 29 with its valve 30 is also provided in case of an upset condition within the system. The valve 30 is normally closed. In an upset condition, the valve 25 would be closed and the valve 30 opened to carry the pulp directly into the tank. The deaerated pulp 31 in the deaeration tank 28 leaves through line 32 to pulp washer 33. The flow in the line 32 is controlled by the height of the pulp in the deaeration tank 28. The pulp is maintained at a constant height in the tank 28. Deaeration tank pulp height sensor 34 controls valve 35 in line 32. The pulp from line 32 enters the tank 36 of washer 33 and the pulp is picked up on drum 37. The mat on the drum 37 is washed by washer heads 38 and 39, dewatered by the vacuum drum 37 and the washed and dewatered pulp leaves the washer 33 at 40.
The filtrate from the pulp mat is carried through the mat into the drum 37 and through the drop leg 41 into the filtrate tank 42.
In the diagram a vacuum washer is shown in which the washer heads 38 carry fresh water and washer head 39 carries counterflow filtrate from a subsequent washer. The flow of counterflow filtrate in washer head 39 is controlled by a valve in the line which is controlled by the level in the filtrate tank of the subsequent washer.
The filtrate 43 in filtrate tank 42 is carried by pump 44 and counterflow line 45 to an earlier washer or decker to be used as wash water. Again the flow of filtrate in this line is controlled by the height of filtrate 43 in tank 42. The filtrate must be maintained at a predetermined height to maintain the vacuum in the washer 33.
Some of the filtrate from line 45 is carried by line 46 to the deaeration tank 28 to be used as the swirling fluid in the deaeration tank. A valve 47 controls the flow in line 46. The amount of filtrate flowing through line 46 will maintain the consistency of pulp in tank 28 at a pumpable consistency. The consistency should be between 1 and 5%. The best consistency is around 3%.
Pressure washers may be substituted for the vacuum washers shown.
The deaeration tank 28 is shown in FIG. 2-4. The deaeration tank 28 is shown as a cylindrical tank 50 having an open top and a flat bottom 51. The tank has an exterior diameter "D". The diameter of the deaeration tank would normally be the same size as the diameter of tank 23 so that it can be placed on top of or hung from the side of tank 23. The deaeration tank, however, may have a diameter of from 0.75 to 1.5 times the diameter of the tank 23. The tank normally has an exterior height of approximately 2"D". The tank should be high enough to prevent the swirling slurry within the tank from spilling over the sides. This height will depend upon the consistency of the pulp slurry. For pulp slurries in the range of 8-15% the exterior height of the tank should be between 1 and 337 D". The nominal height of the pulp slurry in the deaeration tank 28 is 0.8"D". The nominal height of the pulp slurry is the height of the slurry if it were at rest or as measured by its hydrostatic head or by a manometer. The slurry is actually swirling in the deaeration tank and its surface is dished with the center being lower than the nominal height and the periphery being higher than the nominal height. For diagramatic purposes the height of the slurry in FIG. 3 is shown as being between the bottom of the tank and the highest point of the slurry. This was only to illustrate that the dimension was between the bottom of the tank and the surface of the slurry. The dimension given, 0.8"D", is the nominal height of the slurry. The nominal height of the slurry may be between 0.4 and 1.0"D".
The inlet pipe 27 of the tank 28 has its center line between the upper surface of the slurry and the top edge of tank 50, and on a diameter line of the tank 50. The inlet pipe 27 should allow the pulp to enter the tank above the surface of the slurry and to splash against the side wall of the tank 50. The inlet pipe should be low enough in the tank to prevent the pulp from splashing from the tank. It would normally be located from the top of the tank a distance equal to 10-50% of the height of the tank. In a tank having a height of 2"D" and a nominal slurry height of 0.8"D", the horizontal center line of the inlet pipe would typically be approximately 0.5"D" below the upper edge of the tank 50. The inlet pipe extends across the interior the tank a distance greater than 0.5"D" to allow the incoming pulp to strike the side wall of the tank 50. It would usually extend across the tank approximately 0.75 "D". Its length is actually slightly less than this because of its relationship with the outlet 53. Above the inlet pipe 27 and extending across the space between the end of inlet of pipe 27 and the opposing side wall of tank 50 is a splash plate 54. The inlet pipe 27 has an outer flange 52 which connects with a flange on pipe 26. The outside diameter of the inlet pipe 27 is between 0.07 and 0.16"D". The usual outside diameter is approximately 0.095"D⃡.
The tank 28 may be closed and be a pressure or vacuum tank. It will be closed if the oxygen or steam is being recovered. It would be built to withstand pressures of ±1 atmosphere.
The outlet 53 is located in the bottom plate 51 of the deaeration tank 28. Again the outlet 53 will be sized to handle the amount of pulp leaving the tank. This will be greater than the inlet pipe because recycled filtrate is added to the slurry in the tank 50. The outlet 53 has an outside diameter of between 0.12 and 0.2"D". The usual outside diameter of the outlet is approximately 0.14"D". The outlet 53 has a center line located in the same vertical plane as the center line of the inlet line 27. The center line of the outlet 53 is also located between 0.15 and 0.4"D", usually approximately 0.25"D", from the outside of the tank 50 directly below the outlet of inlet pipe 27. As can be seen in FIG. 4, the exact location of the outlet of inlet pipe 27 is along a chord line of the outlet 53. This chordline is approximately the diameter of the inlet pipe 27. The outlet 53 has a flange 55 which attaches to a flange on line 32.
The oxygen filled slurry is carried into the tank by the inlet pipe 27 and splashes against the side of the tank 50 opposite the inlet and drains down to the body of the slurry in the tank 28.
The height of slurry in tank 50 is controlled by the height sensor 34 at the bottom of the tank. The sensor 34 is at an angle of about 60° C. from the center line of the inlet pipe 27. The sensor controls the flow in outlet pipe 32 by operating the valve 25 between the deaeration tank and the washer.
The body of slurry in tank 28 is swirled by filtrate from washer 33. The velocity of filtrate entering the deaeration tank 28 is 6.1 meters per second (20 feet per second), at a 2% pulp consistency. The velocity may range from 4.57 to 12.19 meters per second (15 to 40 feet per second). This filtrate enters the tank through the filtrate swirler inlet 56. The filtrate swirler inlet 56 has a vertical center line that is between the bottom of the tank 50 and the surface of the slurry. It usually would be located from the bottom of the tank a distance equal to one-half of the distance between the bottom of the tank and the nominal height of the pulp slurry. In a tank in which the nominal height of the slurry is 0.8"D" the vertical center line of the filtrate inlet 56 would be 0.4"D". It is preferred that the filtrate swirl inlet be located from the bottom of the tank a distance equal to 10-25% of the height of the tank. The horizontal center line of the filtrate swirler-inlet 56 is between a tangent to the tank 50 and a radial line of the tank 50 that is perpendicular to the radial line passing through the tangent point. It should be placed off a radial line to provide a swirl to the slurry, and off a tangent to allow easier construction. It usually is placed in the same vertical plane as the center line of outlet 53. The filtrate inlet 56 has a diameter at its outer end 57 of from 0.07 to 0.16"D", usually 0.095"D", and necks down to a diameter at its inner end 58 of from 0.02 to 0.04, usually 0.028"D". This construction accelerates the filtrate to the required velocity as it enters the tank 28. The filtrate inlet has a flange 59 at its outer end which attaches to a flange on line 46.
The emergency bypass line 60 also has its center line between the bottom of the tank 50 and the upper surface of the slurry. It also would usually be placed one-half of the way between the bottom of the tank and the nominal height of the slurry. In a tank having a nominal slurry height of 0.8"D" it would usually be 0.4"D" from the bottom of the deaeration tank 28. It is in vertical alignment with the inlet pipe 27 and has a diameter of 0.12 to 0.2"D". It usually has a diameter of approximately 0.14"D". The flange 61 attaches to a flange on line 29.
Mounting brackets 62 and 63 and a mounting platform 64 are also shown.
A 50 ton of pulp per day installation has a tank with an outside diameter of 106.68 cm (42") and a height of 211.46 cm (831/4"). The inlet pipe is 53.34 cm (21") from the top of the tank. The outlet is 26.67 cm (10.5") from the center of the tank. The outside diameter of the inlet pipe is 10.16 cm (4"), of the outlet is 15.24 cm (6"), of the outer part of the filtrate inlet is 10.16 cm (4"), of the outlet of the filtrate inlet is 3.05 cm (1.2"), and of the bypass line is 15.24 cm (6"). | A small deaeration tank which may be either at atmospheric pressure on under low pressure or vacuum and a system of operating this tank which allows pulp which has been treated with oxygen to be deaerated before being washed. A closed tank would allow steam or oxygen to be recovered. Preferably it would be the same diameter as an oxygen reactor so that it could be placed on top of the reactor and be supported by the reactor. It would have no moving parts, so there would be no need for motors to be mounted on or near the tank. The deaerator is a small open tank having an inlet pipe, an outlet pipe, and a tangential swirl inducing inlet pipe. The locations and sizes of these pipes provide optimum deaeration. The swirl inducing fluid is the filtrate from the washer after the oxygen bleach. | big_patent |
FIELD OF THE INVENTION
[0001] This invention relates generally to composite materials and, in particular, to biomimetic tendon-reinforced (BTR) composite materials having improved properties including a very high out-plane stiffness and strength-to-weight ratio.
BACKGROUND OF THE INVENTION
[0002] Composite structures of the type, for example, for military air vehicles are generally constructed from a standard set of product forms such as pre-preg tape and fabric, and molded structures reinforced with unidirectional, woven or braided fabrics. These materials and product forms are generally applied in structural configurations and arrangements that mimic traditional metallic structures. However, traditional metallic structural arrangements rely on the isotropic properties of the metal, while composite materials provide the capability for a high degree of tailoring that should provide an opportunity for very high structural performance-to-weight ratio.
[0003] There is general confidence among the composite materials community that a high-performance all-composite lightweight aircraft can be designed and built using currently available manufacturing technology, as evidenced by aircraft such as the F-117, B-2, and AVTEK 400. However, composite materials can be significantly improved if an optimization tool is used to assist in their design. In the recent past, engineered (composite) materials have been rapidly developed [1-3]. Maturing manufacturing techniques can easily produce a large number of new improved materials. In fact, the number of new materials with various properties is now reported to grow exponentially with time, which results in difficulty in selecting proper materials when designing a new product. [4]
[0004] Composite materials should be designed in such a way that they are optimum for their functions in the structural system and for the loading conditions they will experience. A function-oriented material design (FOMD) process was therefore developed at the University of Michigan and MKP Structural Design Associates, Inc.[5-6] The FOMD process employs an advanced structural optimization method, called topology optimization [7]. Using this technique, the topology optimization problem is transformed into an equivalent problem of optimum material distribution by moving material in the design domain to improve the given objective function. By employing a proper optimization algorithm, the optimization process converges to a design that is optimal for the design problem.
[0005] The topology optimization technique has been generalized and applied to various areas, including structural designs and material designs [8]. It has also been applied to the design of structures for achieving static stiffness, desired eigenfrequencies, frequency response, reduced vibration and noise, and other static, thermal, and dynamic response characteristics. [e.g., 8-10] Combing the topology optimization technique with the FOMD process makes it possible to design new advanced materials—materials with properties never thought possible.
SUMMARY OF THE INVENTION
[0006] This invention improves upon the existing art by providing biomimetic tendon-reinforced (BTR) composite structures with improved properties including a very high structural performance (including out-plane stiffness) and strength-to-weight ratio. A basic structure comprises a plurality of spaced-apart stuffer members, each having a first end and a second end defining a length. A plurality of tendon elements interconnect with the first and second ends of the stuffer members in alternating fashion, such that the tendon elements criss-cross each other between the stuffer members. A first panel is bonded, stitched, or attached to the first ends of the stuffer members, and a second panel is bonded, stitched, or attached to the second ends of the stuffer members. In the preferred embodiments, the first panel, the second panel, or both the first and second panels include curved shapes suitable for different applications.
[0007] The stuffer members may be substantially parallel to one another and of equal or varying lengths. Alternatively, the stuffer members may be aligned along lines extending radially outwardly from a common center point (or multiple common center points, or without any common center point). The first and second panels may or may not be equidistant from one another. One of the panels may have a convex outer surface, with the other panel having a concave outer surface. Alternatively, both of the panels may have convex or concave outer surfaces. As a further alternative, one of the panels may be flat, with the other panel having a convex or concave outer surface. The stuffer members and tendon elements may embedded in a matrix material such as epoxy resin, metallic or ceramic foams, polymers, thermal isolation materials, acoustic isolation materials, and/or vibration-resistant materials.
[0008] The tendon elements may be made of carbon fibers, nylon, Kevlar, glass fibers, plant (botanic) fibers (e.g. hemp, flax), metal wires or other suitable materials. The stuffer members are preferably rigid, semi-rigid, or with desired flexibility, and may be solid or hollow components made of metal, ceramic or plastic. One or both of the panels are solid, perforated or mesh-like.
[0009] The tendon elements may be tied or otherwise attached to one another where they criss-cross, thereby forming joints. If the stuffer members are tubes, the tendon elements may be oriented through the tubes. Alternatively, the tendon elements may be provided in the form of bent wires, each with a first bent end inserted into the first end of a stuffer member and a second bent end inserted into the second end of a different member.
[0010] Both linear and planar structures may be constructed according to the invention. For example, the stuffer members may be arranged in a two-dimensional plane, with the structure further including a panel bonded to one or both of the surfaces forming an I-beam structure. Alternatively, the stuffer members may be arranged in a two-dimensional array such that the ends of the members collectively define an upper and lower surface to which the panels are bonded or attached.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1A depicts the definition of a design problem to be solved by the invention;
[0012] FIG. 1B depicts an optimized structural composite having several key components, including fibers, stuffers, and joints;
[0013] FIG. 2 shows how a matrix may be used to enhance strength;
[0014] FIG. 3 illustrates fundamental components of the BTR composite, which include tendons, ribs, joints, skin, flesh, and shell;
[0015] FIG. 4 shows how the two-dimensional BTR concept is extended to a three-dimensional BTR configuration;
[0016] FIG. 5 illustrates an example potential fabrication process;
[0017] FIGS. 6 a - d shows variations of BTR shapes, including flat, cylindrical, spherical, and cylinder shapes;
[0018] FIGS. 7 a, b show example prototypes developed for various BTR configurations;
[0019] FIG. 8 illustrates BTR concept can be extended to produce a composite armor with added ceramic layer for blast and ballistic protection;
[0020] FIG. 9 shows how fiber elements may be passed through stuffer tubes;
[0021] FIG. 10 shows elongated panel stuffer members;
[0022] FIG. 11 shows a sandwich BTR structure using spheroid stuffer members, at least in one plane;
[0023] FIG. 12 illustrates potential knot designs for assembling special BTR composites, including two-dimensional and three-dimensional structures;
[0024] FIG. 13 is a drawing which illustrates an embodiment of the invention wherein the stuffer members and tendon elements are disposed between curved panels;
[0025] FIG. 14 depicts an embodiment of the invention including two curved panels, one having a radius curvature different than the other;
[0026] FIG. 15 is a drawing which shows two curved panels, also with two radii;
[0027] FIG. 16 depicts an embodiment of the invention having one flat panel and one panel having a convex outer surface with the stuffer elements being parallel to one another;
[0028] FIG. 17 depicts an embodiment of the invention having one flat panel and one panel having a convex outer surface but with the stuffer elements being arranged along lines extending from a common center of curvature;
[0029] FIG. 18 depicts an embodiment of the invention having one flat panel and one panel having a concave outer surface;
[0030] FIG. 19 shows two curved panels, both having concave outer surfaces with the same radius of curvature;
[0031] FIG. 20 illustrates two curved panels, both with concave outer surfaces, but wherein the radius of curvature of one of the panels is different from that of the other;
[0032] FIG. 21 depicts an embodiment of the invention having two curved panels with convex outer surfaces and the same radius of curvature;
[0033] FIG. 22 shows two curved panels with convex outer surfaces and different radii of curvature;
[0034] FIG. 23 shows how panels with complex/compound shapes may be utilized in accordance with the invention;
[0035] FIG. 24 shows how, in all embodiments, the stuffer members and tendon elements may be embedded in a matrix material such as a polymer material, foam, rubber, or other filling material;
[0036] FIG. 25 shows how, in all embodiments, the stuffer members need not be spaced apart from one another by equal (or unequal) distances;
[0037] FIG. 26 shows how, in all embodiments, the tendon elements may be tied, glued or otherwise bonded at the points where they cross, thereby forming “joints;”
[0038] FIG. 27A illustrates the use of hollow stuffer members and tendon elements in the form of bent wires;
[0039] FIG. 27B shows how the components of FIG. 27A look when assembled from the side view perspective;
[0040] FIG. 27C is a top-down view showing four bent-wire tendon elements and a stuffer member having a round cross-section; and
[0041] FIG. 27D is a top-down drawing showing four bent-wire tendon elements and a stuffer member having a non-round cross-section, such as a square.
[0042] FIG. 28 illustrates additional configurations and options for assembling the stuffer members and bent-wire tendons.
DETAILED DESCRIPTION OF THE INVENTION
[0043] This invention uses a methodology called “function-oriented material design,” or FOMD, to design materials for the specific, demanding tasks. In order to carry out a FOMD, first the functions of a particular structure are explicitly defined, such as supporting static loads, dissipating or confining vibration energy, or absorbing impact energy. These functions are then quantified, so as to define the objectives (or constraint functions) for the optimization process. Additional constraints, typically manufacturing and cost constraints, may also need to be considered in the optimal material design process.
[0044] The FOMD system has resulted in a number of innovative structural material concepts, including the BTR (biomimetic tendon-reinforced) composite materials described in this specification. The original concept of the BTR composite was obtained through a topology optimization process which maximizes the out-plane stiffness of a composite made of carbon fiber and epoxy matrix material. The result shows that the fiber should be concentrated and oriented along the most effective load paths identified through the topology optimization process.
[0045] According to this new composite concept, which is different from the traditional fiber-reinforced laminate composites, fibers are evenly distributed in the matrix material. The analyses also showed that the materials in tension and materials in compression can be treated differently in the composite, and can be selected and designed separately with respect to their functionalities in the composite material. Additional covering and filling materials can also be added into the composite, and the further development of the concept through prototyping, testing, and developing fabrication method resulted in a wide range of new BTR composites.
[0046] An example BTR design process is illustrated in FIG. 1 . The goal here is to optimize the out-plane stiffness of the composite material for a given amount of the fiber and matrix materials. As shown in FIG. 1A , a static load was applied at the middle of a design domain fixed at its two ends. The objective function considered in the optimization problem is to minimize the total strain energy stored in the composite. This is equivalent to maximize the out-of-plane stiffness (resisting the out-of-plane load). FIG. 1B shows the optimum layout of the composite obtained using FOMD methods.
[0047] The optimum structural configuration of the composite has several key components, including: fiber, stuffer, and joint, as shown in FIG. 1B . Note that the optimum structure obtained from the concept design implies that the fibers should be concentrated and optimally arranged along the load paths where the reinforcements are most needed. Unlike traditional woven materials, in which the fibers are almost evenly distributed in one plane in the matrix materials, the new material will be reinforced by allocating concentrated fibers, such as fiber ropes, along load paths so as to increase transverse stiffness. In practical applications, a matrix or filling material may (or may not) be used to enhance structural performance, as shown in FIG. 2 .
[0048] One typical BTR composite structure, shown in FIG. 3 , includes six fundamental components: tendons/muscles (represented by fiber cables and/or actuators), ribs/bones (represented by metallic, ceramic, or other stuffers and struts), joints (including knots), flesh (represented by filling polymers, foams, thermal and/or acoustic materials, etc.), skins (represented by woven composite layers or other thin covering materials), and shell (represented by hard and stiff materials, such as metal or ceramic.)
[0049] In different embodiments, the two-dimensional material concept may be extended to a three-dimensional lattice, as shown in FIG. 4 . The preferred structure is made of various raw materials, for example, steel frame, steel columns, carbon-fiber ropes, and carbon fiber/epoxy cover panels. A potential fabrication procedure is shown in FIG. 5 . Here, bent-wire tendon elements 502 are inserted into the ends of stuffer members 504 to create linear structures 506 . These, in turn, may be replicated to create a planar structure 510 . If panels 512 , 514 are added, a lightweight yet rigid structure 516 results.
[0050] FIG. 6 illustrates possible structures using the basic BTR idea. FIG. 6 a shows a flat panel such as that depicted in FIG. 5 . FIG. 6 b shows a curved cylindrical section, and FIG. 6 c shows a curved spherical section. FIG. 6 d shows a complete cylinder may be formed using the process. FIG. 7 further illustrates example prototypes with a wide range of material variations.
[0051] FIG. 8 illustrates a design toolkit developed at MKP Inc., while an example finite element model of the BTR material shown in FIG. 4 is shown in FIG. 9 . The top and bottom plates may be metal carbon fiber/epoxy panel layers. The stuffers may be steel, aluminum or ceramic, and the tendon elements may be carbon fiber ropes. The panels are glued to the frames using epoxy to form the final BTR structure as shown in FIG. 4 . The dimension of the sample lattice structure is 100 mm×100 mm×12 mm. Note that commercial 1-EA codes can also provide an estimate for the response of the BTR under various loads.
[0052] FIG. 8 illustrates an extension of the BTR concept to develop a composite armor, which consists of stuffer, fiber ropes, woven fiber panels, and ceramic layers. Since the BTR structure is ultra-light, the proposed composite armor would benefit the future combat system in the total weight reduction as well as in the energy absorption. The carbon-rope reinforcement plan is optimized to withstand an actual impact.
[0053] In some BTR structures, the carbon ropes may be stitched to the frame structure. FIG. 9 shows how fiber elements 1102 , 1104 may be passed through stuffer tubes 1106 . FIG. 10 shows elongated panel stuffer members 1202 . FIG. 11 shows a sandwich BTR structure using spheroid stuffer members 1302 , at least in one plane. FIG. 12 illustrates potential knot designs for assembling special BTR composites, including two-dimensional and three-dimensional structures.
[0054] An advantage of the BTR composite is the use of embedded fiber tendons. When a load carrying carbon-fiber tendon in a well-designed BTR composite is broken, the neighboring fiber tendons can act as the safety members to preserve the integrity of the whole BTR structure provided the tendons are properly placed. In a practical application, several layers of the proposed BTR structure can be stacked together to provide even better out-of-plane performance when needed.
[0055] While certain of the embodiments so far described have depicted stuffer members and tendon elements disposed between flat, parallel tiles, non-parallel flat panels and non-flat panels may alternatively be used. As one example, FIG. 13 illustrates an embodiment wherein the stuffer members (i.e., 1502 ) and tendon elements (i.e., 1504 ) are disposed between curved panels 1506 , 1508 . In this case, panels 1506 , 1508 share a common radius of curvature from point “p” such that the panels are equidistant. Further in this embodiment the stuffer members are uniformly spaced and aligned along spokes extending radially outwardly from the common center point. Although a 2-dimensional structure is shown (i.e., one set of stuffer members in a plane), it will be appreciated that in this and all other embodiments 3-dimensional structures may be used, in which case addition groups of stuffers would be present in the spaces into and/or out of the plane. Additionally, although panels 1506 , 1508 are hemispherical, in this and all other embodiments using curved panels, non-hemispherical surfaces may be used, including parabolic, hyperbolic, and compound surfaces as shown in FIG. 21 .
[0056] FIG. 14 depicts an embodiment of the invention including two curved panels, 1602 , 1604 one having a radius curvature from point “p” and the other having a different radius of curvature based upon “p′.” The stuffer members are shown extending radially outwardly from point “p” but in this case they vary in length because the panels are not equally spaced apart. FIG. 15 is a drawing which shows two curved panels, also with two radii, but in this case the stuffers are aligned along spokes emanating from “p′.” Other stuffer alignments are possible, including arrangements based upon a center of curvature other than “p” and “p′,” including a center midway between them.
[0057] Curved and flat panels may also be intermixed in accordance with the invention. FIG. 16 for example depicts an embodiment of the invention having one flat panel 1802 and one panel 1804 having a convex outer surface. In this case the stuffer elements are parallel to one another, but as shown in FIG. 17 , the stuffers may be arranged along lines extending from a common center of curvature.
[0058] FIG. 18 depicts an embodiment of the invention having one flat panel 2002 and one panel 2004 having a concave outer surface. The stuffers are arranged along lines extending from a common center of curvature, but other arrangements may be used including parallel positioning.
[0059] FIG. 19 shows two curved panels 2102 , 2104 , both having concave outer surfaces with the same radius of curvature (i.e., r 1 =r 2 ). FIG. 20 illustrates two curved panels, both with concave outer surfaces, but wherein the radius of curvature of one of the panels is different from that of the other (i.e., r 1 ≠r 2 ). FIG. 21 depicts an embodiment of the invention having two curved panels 2302 , 2304 with convex outer surfaces and the same radius of curvature, whereas FIG. 22 shows two curved panels with convex outer surfaces and different radii of curvature. The stuffers are preferably parallel in the embodiments of FIGS. 19-22 .
[0060] FIG. 23 shows how panels 2502 , 2504 with complex/compound shapes may be accommodated in accordance with the invention. Such structures may be optimized, for example, to fabricate vehicular, aerospace and marine body parts. FIG. 24 shows how, in all embodiments, the stuffer members and tendon elements may be embedded in a hardened matrix material 2610 such as epoxy. FIG. 25 shows how, in all embodiments, the stuffer members need not be spaced apart from one another by equal distances, and FIG. 26 shows how, in all embodiments, the tendon elements may be tied, stitched, glued, or otherwise bonded at the points where they cross, thereby forming “joints” 2810 .
[0061] FIG. 27A illustrates the use of hollow stuffer members 2902 and tendon elements in the form of bent wires 2904 . FIG. 27B shows how the components of FIG. 27A appear when assembled from a side view perspective. FIG. 27C is a top-down view showing four bent-wire tendon elements and a stuffer member having a round cross-section, and FIG. 27D is a top-down drawing showing four bent-wire tendon elements and a stuffer member having a non-round cross-section, such as a square. The use of hollow stuffer members and bent-wire tendons simplifies manufacture and may even be automated using pick-and-place robotics, for example. FIG. 28 illustrates additional configurations and options for assembling the stuffer members and bent-wire tendons. In all bend-wire configurations, small pieces such as those shown in FIGS. 27A-27D may be used or, alternatively, the longer pieces of FIG. 5 may be used.
[0062] As with all embodiments described herein, the staffers may be composed of any suitable materials, including ceramic, metal or plastic, preferably semi-rigid or rigid. Although four bent-wire tendon elements are shown inserted into each end of the stuffer members, other arrangements such as three tendon elements may be used, in which case a top-down view of a two-dimensional structure could show multiple triangles or hexagons as opposed to squares, diamonds or parallelograms. It will also be appreciated that the use of hollow stuffer members and bend-wire tendons are not limited to structures including one or more curved plates, in that the stuffers and tendons may be sandwiched between parallel plates or tiles as shown in FIG. 6 , for example.
REFERENCES
[0000]
1. Wojciechowski, S., “New trends in the development of mechanical engineering materials,” Journal of Materials Processing Technology , Vol. 106, pp. 230-235 (2000).
2. Cherradi, N., Kawasaki, A., and Gasik, M., “World Trends in Functional Gradient Materials Research and Development,” Composite Engineering , Vol. 4, No. 8, pp. 883-894 (1994).
3. Ashby, M. F., et al., Metal Foams: A Design Guide , Butterworth-Heinemann, 2000.
4. Ashby, M. F., Materials Selection in Mechanical Design , Pergamon Press, Oxford, D.C., (1992).
5. Ma, Z.-D., Wang, H., Kikuchi, N., Pierre, C., and Raju, B, “Function-Oriented Material Design for Next-Generation Ground Vehicles,” Symposium on Advanced Automotive Technologies, 2003 ASME International Mechanical Engineering Congress & Exposition , Nov. 15-21, 2003, Washington, D.C., IMECE2003-43326.
6. Ma, Z.-D., Jiang, D., Liu, Y., Raju, B., and Bryzik, W., “Function-Oriented Material Design for Innovative Composite Structures against Land Explosives,” 25th Army Science Conference, Nov. 27-30, 2006, Orlando, Fla.
7. Bendsøe, M. P. and Kikuchi, N., “Generating optimal topologies in structural design using a homogenization method,” Comput. Methods Appl. Mech. Energ . Vol. 71, pp. 197-24 (1988).
8. Bendsøe, M. P., Optimization of Structural Topology, Shape, and Material , Springer-Verlag Berlin Heidelberg, 1995.
9. Ma, Z.-D., Kikuchi, N., and Cheng, H.-C., “Topological Design for Vibrating Structures,” Computer Methods in Applied Mechanics and Engineering , Vol. 121, pp. 259-280 (1995).
10. Ma, Z.-D., Kikuchi, N., Pierre, C., and Raju, B., 2006, “A Multi-Domain Topology Optimization Approach for Structural and Material Designs,” ASME Journal for Applied Mechanics , Vol. 73, No. 4, pp. 565-573 (2006). | Biomimetic tendon-reinforced” (BTR) composite structures feature improved properties including a very high strength-to-weight ratio. A basic structure comprises a plurality of spaced-apart stuffer members, each having a first end and a second end defining a length. A plurality of tendon elements interconnect with the first and second ends of the stuffer members in alternating fashion, such that the tendon elements criss-cross each other between the stuffer members. A first panel is bonded or attached to the first ends of the stuffer members, and a second panel is bonded or attached to the second ends of the stuffer members. In the preferred embodiments, the first panel, the second panel, or both the first and second panels are curved. An efficient manufacturing process based upon hollow stuffers and tendon elements in the form of bent wires is also disclosed. | big_patent |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention generally relates to the construction of dynamic load resistant building equipment. More particularly, the present invention relates to a device that dissipates energy during a major dynamic event. Further, the invention relates to a device that limits the loads being transmitted to the parts of the structures that are difficult to repair or replace. The invention relates to a device that may undergo plastic deformation to limit the loads levied on a structure during a dynamic event. The present invention may also be a load-limiting device that can be replaced and/or removed after plastic deformation.
[0003] 2. Description of the Prior Art
[0004] The response of buildings to major seismic events is often of sufficient magnitude to induce inelastic behavior of many components within the building. The inelastic behavior and/or characteristics displayed by the building may take the form of local yielding, cracking, buckling and fracturing of structural members. Often, the damage done to a building during a dynamic event is so severe that it jeopardizes the integrity of the entire building and/or the building must be destroyed to insure public safety.
[0005] A direct consequence of the acceptance of inelastic response of a building during major earthquakes is the possibility of significant damage being incurred during the seismic event. The cost of repairing the damage then becomes a component in the life cycle cost of the building. A well-documented comparison in the response of two difference buildings to an earthquake in Managua in 1972 highlighted the costs of repairing the damage done during a seismic event. (1)
[0006] One of two buildings observed in the comparison utilized a concrete shear wall lateral load carrying system. The concrete shear wall lateral load carrying system was able to withstand the seismic loads with modest damage while an adjacent building used a moment-resistant frame to withstand the lateral loads induced during the earthquake. This was believed to be a ductile system that provided a reliable method for avoiding catastrophic building failure. The building in question did not fail catastrophically but suffered extensive damage associated with inelastic response that proved to be too extensive to be repaired economically. In fact the building using the moment-resistant frame to withstand the lateral loads had to be abandoned and destroyed.
[0007] A structural system that relies on beneficial inelastic action during seismic response was proposed by Popov et al. (2) In that case, a modification was applied to the traditional braced frame building system. The modification of the commonly used braced frame system consisted of installing cross-braces into the building frame with marked end offsets. This had the effect of inducing increased bending stresses in the beam and, ultimately, plastic hinges at the high stress locations. The presence of these hinges may provide a method for dissipating energy in a ductile way. However, the damage associated with the formation of plastic hinges in the beams of the building is very difficult and expensive to repair.
[0008] Another method that has been used to limit structural response during a seismic event adopts a hydraulic damper at strategic locations throughout the frame. (3) This provides a method for dissipating energy from a seismic event in a controlled and engineered way. The disadvantage of this method is that it is very difficult to incorporate energy dissipation similar in magnitude to plastic hinge mechanisms without major cost and inconvenience for older, established building structures. Moreover, incorporating the hydraulic damper has many packaging ramifications associated thereto. Still further, the need for periodic routine maintenance of these hydraulic damper systems in locations throughout the building is a serious disadvantage to this type of system as the routine maintenance may be difficult to perform and costly to complete.
[0009] U.S. Pat. No. 6,651,395 discloses a device that limits relative movement of two elements of a structure by absorbing the deformation energy. The device absorbs the energy by plastic deformation using a method by which the deformable material is restrained by a stronger and stiffer guiding material. The performance of the device is dependent on the precise shape of the guiding component in the device.
SUMMARY OF THE INVENTION
[0010] The present invention provides a dampening system for bracing the frame of a structure during a dynamic event. More particularly, the present invention relates to a load-limiting device for braced frames. Moreover, the present invention relates to a load-limiting device that may be placed in a braced frame that may have plastic deformation characteristics. Further, the present invention relates to a load-limiting device that may be placed in a braced frame that may plastically deform during a dynamic event and wherein the load-limiting device may preserve a structure from extensive and/or comprehensive damage to the structure after a dynamic event. Moreover, the present invention relates to a load-limiting device that may plastically deform in response to a dynamic event and that may be positioned within a braced frame structure. The load-limiting device may be easily removed and replaced after plastic deformation with another non-plastically deformed load-limiting device.
[0011] To this end, in an embodiment of the present invention, a load-limiting device for use in a braced frame is provided. The device for use in the braced frame has a braced frame structure having at least one beam and a first column and a second column. Moreover, the present invention has a load-limiting device releasably attached to a brace wherein the brace is attached to the braced frame structure. Further, the present invention has a connection means releasably attached to the load-limiting device. Additionally, the invention has a load-limiting device providing biaxial support for the braced frame wherein said load-limiting device is being able to dissipate energy in the braced frame structure.
[0012] In an embodiment, the load-limiting device is able to plastically deform in response to a load applied thereto.
[0013] In an embodiment, the load-limiting device is able to plastically deform in response to load wherein said load-limiting device has elasto-plastic properties to allow for formation of a plastic hinge mechanism.
[0014] In an embodiment, the load-limiting device can withstand small loads without plastic deformation based on elasto-plastic properties.
[0015] In an embodiment, the load-limiting device is constructed of a plastic material.
[0016] In an embodiment, the load-limiting device is constructed of a metal based elasto-plastic material.
[0017] In an embodiment, the load-limiting device is attached to said connection means wherein said connection means couples the load-limiting device and the brace in the braced frame structure.
[0018] In an embodiment, the load-limiting device has an opening thereon for attachment of the connection means to the brace.
[0019] In an embodiment, the load-limiting device has a plurality of connection points wherein said connection points are releasably attached to said connection means.
[0020] In an embodiment of the present invention, a dynamic load, load-limiting device system for a braced frame is provided. The system has a braced frame structure having at least one beam and a first column and a second column. The system further has a brace frame structure having at least one brace. Moreover, the system has a load-limiting device releasably attached to said brace wherein said brace attaches to said at least one beam and a connection means detachably coupled to said at least one brace and said load-limiting device. Moreover, the system has the load-limiting device in connection with said brace and said braced frame structure to dissipate energy when high lateral loads are placed on the braced frame structure.
[0021] In an embodiment, the load-limiting device may undergo plastic deformation when subjected to high lateral loads.
[0022] In an embodiment, the load limiting device is releasably attached to said brace wherein said brace is attached to said at least one beam.
[0023] In an embodiment, the load limiting device is releasably attached to said brace wherein said brace is attached to said two columns.
[0024] In an embodiment, the load-limiting device when subjected to a dynamic event may yield to form hinged mechanisms to dissipate energy from the braced frame structure during a dynamic event.
[0025] In an embodiment, the load-limiting device may be removed from the braced frame structure after a dynamic event wherein the load-limiting device has undergone plastic deformation and further wherein a new un-deformed load-limiting device may be inserted into the braced frame structure to replace a plastically deformed load-limiting device.
[0026] In an embodiment of the present invention, a method for using a load-limiting device system is provided. The system comprising the steps of: providing a braced frame having at least one beam and two side columns; integrating at least one brace into the braced frame; integrating a load-limiting device into the system; and providing a connection means to connect the load-limiting device to the braced frame wherein a connection means is releasably attached to said load-limiting device and said brace.
[0027] In an embodiment, the method further comprises the step of: placing the load-limiting device into an existing braced frame with a connection means.
[0028] In an embodiment, the method further comprises the step of: providing the device with an indicator means wherein said indicator means allows for assessment of plastic deformation of the load limiting device.
[0029] In an embodiment, the method further comprises the step of: periodically checking said load-limiting device for the existence of plastic deformation after dynamic activity.
[0030] In an embodiment, the method further comprises the step of: removing a plastically deformed load-limiting device from a braced frame after a dynamic event.
[0031] In an embodiment, the method further comprises the step of: replacing a plastically deformed load-limiting device from a braced frame with an un-deformed load-limiting device after a dynamic event.
[0032] It is, therefore, an object of the present invention to provide a load-limiting device, a system and a method of using the same.
[0033] Another object of the present invention is to provide a load-limiting device and a method for using the same, for use in structural applications.
[0034] Still another object of the present invention is to provide a load-limiting device and a method for using the same wherein the load-limiting device may be integrated into a structural frame.
[0035] Yet another object of the present invention is to provide a load-limiting device and a method for using the same wherein the load-limiting device may be integrated into a structural frame having an X- or K-brace.
[0036] Still another object of the present invention is to provide a load-limiting device and a method for using the same wherein a frame incorporating the load-limiting device may withstand lateral seismic loads.
[0037] Yet another object of the present invention is to provide a load limiting device and a method for using the same wherein the load limiting device may withstand high dynamic loads.
[0038] Another object of the present invention is to provide a load-limiting device and a method for using the same wherein the load-limiting device may be compressed.
[0039] Yet another object of the present invention is to provide a loading limiting device and a method for using the same wherein the load-limiting device may withstand high seismic stress.
[0040] Another object of the present invention is to provide a load limiting device and a method for using the same wherein the load-limiting device may not undergo plastic deformation during low dynamic loads.
[0041] Still another object of the present invention is to provide a load-limiting device and a method for using the same wherein the load-limiting device may have a plurality of connection points to connect to a typical braced frame.
[0042] An object of the present invention is to provide a unique load-limiting device and a method for using the same wherein the load-limiting device may have a plurality of connection points and an opening therein.
[0043] A further object of the present invention is to provide a load-limiting device and a method for using the same wherein at low load levels the device will experience stresses within the linear elastic range for the material used in the load-limiting device wherein the load limiting device will not undergo plastic deformation.
[0044] Still another object of the present invention is to provide a load-limiting device and a method for using the same wherein the device may be comprised of metal.
[0045] Yet another object of the present invention is to provide a loading limiting device and a method for using the same wherein the device may be comprised of a high strength material.
[0046] Another object of the present invention is to provide a load-limiting device and a method for using the same wherein the device may be comprised of any material capable of undergoing plastic deformation.
[0047] Yet another object of the present invention is to provide a load-limiting device and a method for using the same wherein the load-limiting device may have a design that avoids local stress risers that may prematurely yield or fatigue with normal loads on a structure.
[0048] Still another object of the present invention is to provide a load-limiting device and a method for using the same wherein the load-limiting device may use materials that have elasto-plastic stress strain properties.
[0049] Another object of the present invention is to provide a load-limiting device and a method for using the same wherein the device may have elasto-plastic stress strain properties similar to low-carbon steels.
[0050] A further object of the present invention is to provide a load-limiting device and a method for using the same wherein the performance of the load-limiting device may not be impaired by strain-hardening of the material in the active part of the device.
[0051] Yet another object of the present invention is to provide a load-limiting device and a method for using the same that as deflections in the structure are increased, yielding of the device avoids a significant increase in internal loads in the building structure itself.
[0052] Another object of the present invention is to provide a load-limiting device and a method for using the same wherein the load-limiting device may form a plastic hinge mechanism when subject to loads.
[0053] An object of the present invention is to provide a unique load-limiting device and a method for using the same wherein the device may have a plastic hinge mechanism that may be induced during plastic deformation of the load-limiting device.
[0054] Still another object of the present invention is to provide a load-limiting device and a method for using the same wherein the device may have a plastic hinge mechanism wherein the plastic hinge mechanism may deform in response to a dynamic event.
[0055] Another object of the present invention is to provide a load-limiting device and a method for using the same wherein the device may be used in buildings, vehicles, aircraft, furniture, roller-coasters and other structures.
[0056] An object of the present invention is to provide a load-limiting device and a method for using the same wherein the device may be used for bridges, office or industrial buildings, homes, heavy lifting equipment and/or any structure that experiences severe dynamic loads and/or any structure prone to seismic events.
[0057] Yet another object of the present invention is to provide a load-limiting device and a method for using the same wherein the device may be able to dissipate energy during a dynamic and/or seismic event.
[0058] Still another object of the present invention is to provide a load-limiting device and a method for using the same wherein the device may be able to dissipate energy during a dynamic event by further yielding of the material in the plastic hinges of the load-limiting device.
[0059] Another object of the present invention is to provide a load-limiting device and a method for using the same wherein the plastic moment of a section of the device may be proportional to the plastic section modulus and the yield strength of the material used.
[0060] A further object of the present invention is to provide a load-limiting device and a method for using the same wherein the device may be able to dissipate energy during many load reversal cycles without premature failure due to cracking and/or buckling.
[0061] Yet another object of the present invention is to provide a load-limiting device and a method for using the same wherein the device may undergo reverse yielding and allow for a plastic hinge mechanism to be compressed.
[0062] Still another object of the present invention is to provide a load-limiting device and a method for using the same wherein the device may be manufactured with a plurality of load capacities depending on the strength requirements of the load-limiting device.
[0063] Still another object of the present invention is to provide a load-limiting device and a method for using the same wherein the load-limiting device strength may vary from story to story in the structure in which it is placed.
[0064] An object of the present invention is to provide a load-limiting device and a method for using the same wherein the device may be able to maintain ductility during severe load-limiting cycles.
[0065] Yet another object of the present invention is to provide a load-limiting device and a method for using the same wherein the device may be checked after an earthquake of moderate to severe intensity.
[0066] Still another object of the present invention is to provide a load-limiting device and a method for using the same wherein the device may be easily removed from the structure if plastic deformation of the device is found.
[0067] Another object of the present invention is to provide a load-limiting device and a method for using the same wherein the device may be easily removed from the structure of a building after a seismic event if plastic deformation of the device is detected.
[0068] Another object of the present invention is to provide a load-limiting device and a method for using the same wherein the device may be removed from the structure after a dynamic event if plastic deformation of the device is detected and further wherein a new load-limiting device may be inserted into the place of the plastically deformed load-limiting device.
[0069] Yet another object of the present invention is to provide a load-limiting device and a method for using the same wherein the device may be configured with a variety of variations depending on the type of structure for which the device is to be fitted.
[0070] Still another object of the present invention is to provide a load-limiting device and a method for using the same wherein the device is interchangeable with new load-limiting devices.
[0071] Yet another object of the present invention is to provide a load-limiting device and a method of using the same wherein the device may be connected to the X-brace of a building by a connection means.
[0072] Another object of the present invention is to provide a load-limiting device and a method of using the same wherein the load-limiting device may be connected to the bracing of the building by a connection means where the connection means may be a mechanical connection using high strength fasteners.
[0073] Yet another object of the present invention is to provide a load-limiting device and a method of using the same wherein the load-limiting device may be connected to the beam and/or column of a structure by a connection means wherein the connection means may be any means of connecting the load-limiting device to the braced frame structure.
[0074] A further object of the present invention is to provide a load-limiting device and a method for using the same wherein the load-limiting device may be rectangular in shape.
[0075] Still another object of the present invention is to provide a load-limiting device and a method for using the same wherein the load-limiting device may be square in shape.
[0076] Another object of the present invention is to provide a load-limiting device and a method for using the same wherein the load-limiting device may be oval in shape.
[0077] An object of the present invention is to provide a load-limiting device and a method for using the same wherein the load-limiting device may be circular in shape.
[0078] Still another object of the present invention is to provide a load-limiting device and a method for using the same wherein the load-limiting device may be connected to the existing brace of constructed building to stabilize and dissipate energy from a dynamic event.
[0079] Yet another object of the present invention is to provide a load-limiting device and a method for using the same wherein the load-limiting device may be applied externally to brace a building frame.
[0080] Another object of the present invention is to provide a load-limiting device and a method for using the same wherein the load-limiting device may be used on internally braced structures.
[0081] Still another object of the present invention is to provide a load-limiting device and a method of using the same wherein the device may be connected to the brace of a structure using a connection means wherein the connection means may be any mechanism to connect the device to the beam of the structure.
[0082] These and other objects of the invention will become more clear when one reads the following specification, taken together with the drawings that are attached hereto. The scope of protection sought by the inventors may be gleaned from a fair reading of the Claims that conclude this specification.
[0083] Additional features and objects of the present invention are described in, and will be apparent from, the detailed description of the presently preferred embodiments and from the drawings.
DESCRIPTION OF THE DRAWINGS
[0084] FIG. 1 is a perspective view of a load-limiting device attached to the frame of a structure in an embodiment of the invention;
[0085] FIG. 2 is a schematic representation of the prior art braced frame of a building which does not include a load-limiting device;
[0086] FIG. 3 a is a close-up schematic representation of the prior art braced frame of a structure which does not include a load-limiting device;
[0087] FIG. 3 b is a close-up schematic representation of a braced frame having a load-limiting device in an embodiment of the present invention;
[0088] FIG. 4 is a schematic illustrating a structure and the stresses involved during a dynamic event wherein the load-limiting device is illustrated in a previous state before dynamic activity and during a dynamic state;
[0089] FIG. 5 illustrates the plastic deformation undergone by the load-limiting device in an embodiment of the present invention;
[0090] FIG. 6 is an illustration of the load deflection sequence for the load-limiting device during a dynamic event in an embodiment of the present invention;
[0091] FIG. 7 is an illustrative view of a plurality of different load-limiting device geometries for various bracing configurations in an embodiment of the present invention;
[0092] FIG. 8 is an illustrative view of potential geometries for the load-limiting device in an embodiment of the present invention; and
[0093] FIG. 9 is a schematic of the external surface of a structure having external load-limiting devices in an embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0094] Turning now to the drawings wherein elements are identified by numbers and like elements are identified by like numbers throughout the 10 figures, the invention is depicted in FIG. 1 and shows a load-limiting device 1 for dissipating energy during a dynamic and/or seismic event. In a preferred embodiment of the present invention, the load-limiting device 1 may have a first side 3 , a second side 5 , a third side 7 and a fourth side 9 . It should be understood that although a preferred embodiment of the present invention illustrates a four sided object, the invention is in no way limited to a load-limiting device 1 having four sides. On the contrary, the invention includes inter alia, load-limiting devices as illustrated in FIG. 8 that may be manufactured and used in a plurality of different shapes and sizes to accommodate various structural applications. In a preferred embodiment, the structural application is for a building. The load-limiting device 1 in a preferred embodiment may have a first connection point 11 , a second connection point 13 , a third connection point 15 and a fourth connection point 17 .
[0095] As illustrated in FIG. 1 , the load-limiting device may have a connection means 19 that may attach the load-limiting device 1 to a brace 21 means that may attach to the frame (not shown) of the structure. The connection means 19 may attach to an opening 23 on the load-limiting device 1 that may allow for connection means 19 to be attached through opening 23 and ultimately connected to the frame of the building by brace 21 . The connection means 19 may be any means of connecting the load-limiting device 1 to the frame of the building and/or structure. The connection means 19 may be releasably attached to the load-limiting device 1 and/or it may be an external portion that may be attached to the load-limiting device 1 . The connection means may be a high strength bolt that passes through the opening 23 of the load-limiting device 1 that allows the brace to be clamped to the load-limiting device 1 . The connection means 19 may also be a weld, adhesive bonding, clevis, shackle and/or any other means for connecting the load-limiting device 1 to the brace 21 of the structure 27 .
[0096] FIG. 2 illustrates the prior art braced frame system 25 often employed in a structures 27 that is prone to dynamic and/or seismic activity. The braced frame system 25 consists of attaching a brace 21 to the building frame beams 29 with little or no joint eccentricity. As illustrated in FIG. 3 a , the building frame may have a first beam 31 and a second beam 33 and a first column 35 and a second column 37 that may be connected to a brace 21 which extends from a first beam 31 to a second beam 33 . The braced frame system 25 tends to be a reliable method of dissipating energy during a dynamic event without being subject to member yielding. A problem with the braced frame system 25 is that during a severe dynamic event, high stresses may be imposed in the frame beams 29 and if the stresses are high enough, they can cause serious or irreparable damage to the structure. The mechanism associated with the damage may be brittle in nature and lead to catastrophic failure.
[0097] FIG. 3 a further illustrates the prior art typical bay in the braced frame systems 25 used in the construction of a structure 27 in an attempt to accommodate lateral loads when a structure 27 is subjected to a dynamic load. As FIG. 3 a illustrates, the brace 21 is attached to the first beam 31 and the second beam 33 of the structure 27 and when subjected to a dynamic load, the brace 21 may stretch to accommodate these loads. However, if the loads imposed on the brace 21 are too great, severe damage may be caused to the structure 27 and extensive repairs must be made to repair and/or reconstruct the structure 27 .
[0098] FIG. 3 b illustrates the same braced frame system 25 that may include the load-limiting device 1 contained therein. The braced frame system 25 consists of a first beam 31 connected to both a first column 35 and a second column 37 . The first column 35 and the second column 37 are connected to a second beam 33 that is parallel to the first beam 31 . A brace 21 may be connected to the frame structure within the interconnected beams 31 , 33 and columns 35 , 37 . The brace 21 may be connected to a first beam 31 and extend to the second beam 33 . In another embodiment, the brace 21 may extend from a first column 35 of the braced frame system 25 to a second column 37 of the braced frame system 25 . The load-limiting device 1 illustrated in this embodiment is rectangular in shape. However, any shape and/or size of load-limiting device 1 may be contemplated. The load-limiting device 1 may be placed at a point on the brace 21 that may be connected to the beams 31 , 33 and/or the columns 35 , 37 of the structure 27 . In a preferred embodiment, the load-limiting device 1 may be positioned centrally between a plurality of braces 21 in the structure 27 . Moreover, the load-limiting device 1 may be located centrally between the interconnected beams 31 , 33 and columns 35 , 37 . The load-limiting device 1 may be connected to the brace 21 by a connection means 19 . The load-limiting device 1 , during dynamic loading of the braced frame structure 27 may undergo plastic deformation to dissipate and/or absorb dynamic energy. Moreover, after a dynamic load has been placed on a load-limiting device 1 and the load-limiting device 1 has undergone plastic deformation, the load-limiting device 1 may be removed from the structure 27 by disengaging the connection means 19 , removing the load-limiting device 1 and replacing the used, elasto-plastically deformed load-limiting device 1 with a new load-limiting device that has not undergone plastic deformation.
[0099] FIG. 4 illustrates a schematic of the deformation process of the modified braced frame system that shows the brace forces 41 acting on the load-limiting device 1 . FIG. 4 further illustrates the inertia force 43 placed on a structure 27 and more specifically on the beam 31 , 33 and braces 21 of the structure 27 during a dynamic event. If and when a structure 27 is exposed to a dynamic event, the inertia force 43 induced by the dynamic event would act on the braces 21 , the beams 31 , 33 , the columns 35 , 37 and the load-limiting device 1 . FIG. 4 further illustrates the inertia forces 43 induced by the dynamic event causing the braces 21 and the load-limiting device 1 to move in relation to the inertia forces 43 placed on the structure 27 . The deformed geometry of FIG. 4 illustrates that plastic hinges 45 have formed at the corners of the load-limiting device 1 . In the plastically deformed configuration, the loads carried by the load-limiting device 1 and the associated braces 21 may not be increased appreciably. The shear force being carried by the braced bay may not increase even when the bay inter-story sway increases. This behavior limits the magnitude of the loads acting on other parts of the frame including the beams 31 , 33 and the columns 35 , 37 , avoiding the possibility of fracture of other less ductile components in the braced frame system 25 .
[0100] FIG. 5 illustrates the load-limiting device 1 during a severe loading event in which parts of the load-limiting device 1 have plastically deformed. The regions that have deformed plastically are generally referred to as a plastic hinge 45 , because of the change in angle from one side of the plastic hinge 45 to the other side. The plastic hinge 45 is bounded on one side by a connection portion 44 which is designed to be strong enough to preclude plastic deformation. The plastic hinge 45 is bounded on a second side by an elastic portion 48 which takes up most of the length of the bottom cord of the load-limiting device 1 . Within the elastic portion 48 , the stresses are low enough that the load-limiting device 1 material remains elastic.
[0101] As FIG. 5 further illustrates, the load-limiting device 1 may have an opening 47 thereon wherein the opening may allow for connection to a connecting means 19 that may attach the load-limiting device 1 to the braces 21 of the structure 27 . During high loads, the load-limiting device 1 may undergo plastic deformation as shown in FIG. 5 . The areas of the load-limiting device 1 that deform plastically versus elastically are a function of the geometry of the load-limiting device 1 and the orientation of the braces 21 . FIG. 5 illustrates plastic hinging 45 in the horizontal portion of the load-limiting device 1 . In another embodiment of the present invention, the plastic hinging may occur in the vertical portion of the load-limiting device 1 . Moreover, plastic hinging may occur in both the horizontal portion and the vertical portion of the load-limiting device 1 .
[0102] The load-limiting device 1 is able to dissipate energy by further yielding of the material enclosed in the plastic hinges 45 as further deformation is imposed. The amount of energy dissipated may be dependent on the geometry of the braced frame system 25 , the geometry of the load-limiting device 1 and the plastic moment capacities of the relevant load-limiting device 1 cross-sections. The plastic moment of a section may be proportional to the plastic section modulus and the yield strength of the materials used. The design of the load-limiting device 1 may account for all these variables so that an optimum load-limiting device 1 may be manufactured that would have adequate elastic strength to survive design wind loads. Moreover, the design would allow for dissipation of energy during many load cycles without premature failure due to cracking and/or buckling during severe seismic events.
[0103] FIG. 6 illustrates the load-deflection sequence for the load-limiting device 1 during a dynamic event when the load-limiting device 1 is subjected to diagonally oriented loads as illustrated in FIG. 4 . The area enclosed by the load-deflection plot during a load cycle is a direct measure of the energy dissipated by the load-limiting device 1 during one cycle of the dynamic event. The peak ordinate of the plot is proportional to the plastic moment of the device cross-section. The peak abscissa is related to the maximum shear and/or plastic deformation experienced by the load-limiting device. FIG. 6 illustrates the elastic loading 47 portion of the load-limiting device 1 in relation to the elastic unloading 49 portion and the elastic re-loading 51 portion of the load-limiting device 1 .
[0104] FIG. 7 illustrates different device geometries for various braced frame systems 25 having different configurations. The basic prior art braced frame systems 25 are typically of the X-brace 53 or K-brace 55 type. The X-brace 53 or K-brace 55 type of configuration has braces 21 that attach to the beams 31 , 33 in a plurality of different formats. Changing the shape of the load-limiting device 1 could accommodate several other bracing configurations. When a different type of brace system 25 is employed, the load-limiting device 1 geometry and shape may be changed to accommodate the differently braced system 25 . However, the load-limiting device 1 geometry and/or shape may be changed to accommodate connection features, manufacturing techniques, materials, architectural detail, and other variables in structural design and purpose. As FIG. 8 illustrates, there is very little limitation in the shape of the load-limiting device 1 . The load-limiting device may be constructed in a plurality of geometries and/or shapes provided that a plastic hinge mechanism 45 can be supported when the device is severely loaded. A suitable load-limiting device 1 may exhibit the same plastic hinging mechanism 45 when the load is reversed.
[0105] FIG. 9 illustrates a further innovative application of the load-limiting device 1 . FIG. 9 illustrates the use of a load-limiting device 1 in conjunction with externally mounted braces 21 . In some situations, the structure 25 and/or building will use a brace system mounted on the outside of the structure 25 that may cover-several stories of the structure 25 . The load-limiting device 1 may be used in this type of external bracing system in a similar fashion as the internal bracing systems. The dimension of the load-limiting device 1 may be greatly expanded to be adapted for external applications but may be used, none the less.
[0106] The load-limiting device 1 may need to be checked after a dynamic event of moderate to severe intensity. In the case of a moderate event it is possible that the load-limiting device may not have suffered any yielding and therefore can be left in place. Some damage may be expected for a major dynamic event and may be apparent by visual inspection of the structure. A “kinked” configuration of the type shown in FIG. 5 may be noticed during inspection of the load-limiting device 1 . However, it is possible that yielding may not be obvious during the post dynamic event inspection. Therefore, in an embodiment of the present invention as illustrated in FIG. 1 , an indicator means 55 may be used to indicate whether plastic deformation has begun on a load-limiting device 1 . In an embodiment, the indicator means 55 may be a brittle coat of material that may be applied to the load-limiting device 1 in order to accentuate the presence of yielding and hence make detection of plastic deformation much more simplistic. A colored brittle coat may be used to assist in detection of plastic deformation and/or yielding. In another embodiment of the present invention, the indicator means 55 may be a mechanical device (not shown) to illustrate plastic deformation. In another embodiment, an electronic sensor (not shown) may be used as an indicator means 55 to confirm plastic deformation. However, it should be understood that any indicator means may be used that may indicate the presence of plastic hinging and/or plastic deformation.
[0107] While the invention has been described with reference to a particular embodiment thereof, those skilled in the art will be able to make various modifications to the described embodiment of the invention without departing from the true spirit and scope thereof. It is intended that all combinations of elements and steps which perform substantially the same function in substantially the same way to achieve substantially the same result are within the scope of this invention.
REFERENCES
[0000]
(1) Wyllie, L. A., et. al., “Effects on Structures of the Managua Earthquake of Dec. 23, 1972”, Bulletin of the Seismological Society of America, Vol. 64, No. 4, August, 1974.
(2) Popov, Egor P., Amin, Navin R., Louie, Jason J. C., and Stephen, Roy M., “Cyclic Behavior of Large Beam-Column Assemblies,” Earthquake Spectra, Earthquake Engineering Research Institute, vol. 1, No. 2, pp. 9-23, 1985.
(3) Taylor, Douglas P., “Seismic isolator and method for strengthening structures against damage from seismic forces”, U.S. Pat. No. 5,462,141, Oct. 31, 1995. | A load-limiting device for using in a braced frame structure is provided. The load-limiting device may be placed in a braced frame and connected to the braces of the braced frame. The load-limiting device is able to limit the lateral loads induced in the structure during a dynamic event by plastic and ductile deformation. The load-limiting device, by limiting the dynamic loads in the braced frame, may protect other less ductile areas of the structure from the loads that might lead to extensive damage, member failure and/or structural collapse. The load-limiting device is positioned within a braced frame structure and may be easily removed after it has undergone plastic deformation and replaced with an undeformed load-limiting device. The load-limiting device exhibits elastic strength to survive, without deformation, minor load scenarios. The device is suitable for retrofitting in existing structures that are susceptible to dynamic activity and that have inadequate dynamic loading capacity. | big_patent |
FIELD AND BACKGROUND OF THE INVENTION
The present invention relates to a bedroom cabinet, and more specifically, to a unit type bedroom cabinet which is optimum to provide a flophouse facility comprising a number of individual rooms on the floor of an existing building.
There have been heretofore proposed unit type bedroom cabinets used as a flophouse requiring no bath room or a flophouse for taking a nap. This bedroom cabinet is designed so that it has a floor area at least approximately equal to an area of a bed, has a height such that a user can erect the upper half of his body on the bed, and has the circumference completely shut off from the outside except a doorway. Such a bedroom cabinet can be carried afer it has been assembled and completed and can be simply installed for workmen's quarters or a stadium in a site of construction. In this case, since of course a plurality of bedroom cabinets can be arranged in a plane on the floor of the building and one bedroom cabinet can be stacked on the other, many workmen can be received in a limited floor area for rest. Fixing one's eyes upon this advantage, an attempt has been also made to provide a flophouse in which a number of bedroom cabinets as described above are installed for users to take a nap at at low charges.
DESCRIPTION OF THE PRIOR ART
Such a bedroom cabinet is disclosed, for example, in U.S. Pat. No. 4,395,785 invented by the inventor of the present application. This bedroom panel is assembled in the box-shape by six single layer panels, that is, a bottom panel, a ceiling panel, a front panel, a back panel, a left side panel and a right side panel. The front panel is provided with an opening for an exit, and the bottom panel has a mat thereon. Within the cabinet are projectingly provided an inclined portion which serves as a backrest when a user sits on the mat, a box for accommodating therein a TV receiver, and a box used for accommodating therein an interphone or a radio receiver. The box for a TV receiver can be provided at an upper corner within the cabinet, thus posing no problem, but the box for an interphone is provided at a lower position to which user is easily accessible. Thus, if a protruded portion is provided at the lower portion of the cabinet, a dwelling area is reduced through that amount. The bedroom cabinet is composed of single layer panels and a vent is provided on the panel which serves as a side wall surface. Therefore, the side wall portion is likely to be decreased in strength and in addition there has been encountered a problem in terms of sound-proof.
In this case, there is an idea such that the box is projected from the outer peripheral surface of the cabinet so as not to narrow the dwelling area. However, the provision of a portion projected from the outer periphery of the cabinet makes it necessary to provide a clearance through that projected portion and in addition deteriorates an external appearance, where a plurality of cabinets are stacked or installed adjacent to each other.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to overcome these disadvantages noted above with respect to conventional bedroom cabinets and provide a bedroom cabinet in which the external surfaces thereof are formed to be flat.
It is a further object of the invention to provide a bedroom cabinet in which shelves for accommodating therein a user's belongings and a box for accommodating therein devices such as an interphone can be provided within the cabinet without being projected therein and without being projected from the outer periphery of the bedroom cabinet.
In accordance with the present invention, there is provided a bedroom cabinet formed into a box-shape by a hexahedron consisting of four side surfaces, an upper surface and a lower surface, comprising an outer casing composed of upper and lower outer casings, the upper outer casing having front and rear side portions, left and right side portions and an upper surface portion integrally formed, the front side portion being formed with a notch portion corresponding to the upper half of an exit, the lower outer casing having front and rear side portions, left and right portions and a lower surface portion integrally formed, the front surface portion being formed with a notch portion corresponding to the lower half of the exit; an inner casing positioned within the outer casing and comprising a front surface panel, a back panel, left and right side panels, a ceiling panel and a bottom panel, the front surface panel having an opening in communication with the notches of the upper and lower outer casings and having an area approximately equal to the exit, the bottom panel having a mat thereon, wherein a peripheral edge at the lower end of the upper outer casing and a peripheral edge at the upper end of the lower upper casing are respectively formed with outwardly projected flanges, and the outer casing is assembled in such a way that the flange of the upper outer casing is brought into abutment with the flange of the lower outer casing.
The bedroom cabinet of the present invention is of the dual construction comprising the outer casing and the inner casing, and therefore it is excellent in mechanical strength. In addition, by providing a clearance is formed between the outer casing and the inner casing a box in which electric devices such as an illuminating instrument, an interphone or the like is mounted or a box which serves as a shelf for accommodating therein a user's belongings can be formed in this clearance, and therefore such boxes will not be projected within the cabinet and from the outer periphery of the outer casing. Accordingly, the dwelling area can be effectively utilized, and since the external surfaces of the cabinet are formed to be flat, a plurality of bedroom cabinets can be closed stacked or installed adjacent to each other. The clearance between the outer and inner casings used to form a box can house therein wirings or the like for interior electric devices.
The present invention further provides a bedroom cabinet wherein a clearance between an outer casing and an inner casing is formed over the whole periphery, and spacer members are interposed in the clearance in a suitably spaced relation, the spacer member being formed with a venting groove. Thereby, an uniform air flowpassage is formed in the outer periphery of the inner casing whereby natural ventilation within a room can be carried out smoothly, and sound-proofing effect can be also increased.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view showing one embodiment of a bedroom cabinet in accordance with the present invention.
FIG. 2 is a front view in longitudinal section of the bedroom cabinet of FIG. 1.
FIG. 3 is a sectional view taken on line 3--3 of FIG. 2.
FIG. 4 is a sectional view taken on line 4--4 of FIG. 2.
FIG. 5 is a perspective view showing the bedroom cabinet of FIG. 1 in an exploded form.
FIG. 6 is a perspective view, in an exploded form, showing a joint between an upper outer housing and a lower outer housing.
FIG. 7 is a front view in longitudinal section showing a further embodiment of the present invention.
FIG. 8 is a sectional view taken on line 8--8 of FIG. 7.
FIG. 9 is a perspective view showing a part of a spacer.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
One embodiment of a bedroom cabinet of the present invention shown in FIGS. 1 through 6 will be described. A bedroom cabinet has an upper outer housing 11 and a lower outer housing 12 which are integrally formed of a fiber reinforced plastic (FRP) or the like. The upper outer housing 11 has an upper surface portion 13, a back surface portion 14, left and right side surfaces 15 and a front portion 16, the front portion 16 being formed with a notch portion 18 for forming the upper half of an exit 17. The lower outer housing 12 has a lower surface portion 9, a back surface portion 20, left and right side surfaces 21 and a front portion 22, the front portion 22 being formed with a notch portion 23 for forming the lower half of the exit 17. The upper surface portion 13 and back surface portion 14 of the upper outer housing 11 and the lower surface portion 19 and back surface portion 20 of the lower outer housing 12 are respectively formed with a plurality of recesses 24 having a required width, and the recess 24 in the upper surface portion 13 of the upper outer housing 11 is formed with a number of venting through-holes 25 in a suitably spaced relation. A peripheral edge at the lower end of the upper outer housing 11 and a peripheral edge at the upper end of the lower outer housing 12 are respectively formed with horizontally outwardly projecting flanges 26, 27 so that when the upper outer housing 11 is placed on the lower outer housing 12, these flanges 26, 27 are placed in abutment with each other.
The upper and lower outer housings 11 and 12 are internally provided with an inner casing 2 comprising a front panel 31, a back panel 32, a right side panel 33, a left side panel 34, a ceiling panel 35 and a bottom panel 36, totalling to six panels. The front panel 31 positioned on the side of the exit 17 is provided with an opening 37 corresponding to the exit 17, as shown in FIGS. 4 and 5. One surface adjacent to the opening 37 is formed with a box 40 in which an illuminating device 38 or an interphone 39 is mounted and a box 42 in which a device 41 such as a clock or a radio receiver is mounted. These boxes 40 and 42 are formed to be projected outwardly. Upper and lower ends of the front panel 31 are inwardly bent to form a flange 43 on which is mounted a curtain rail 45 for a curtain 44 to block the exit 17. The back panel 32 is formed with boxes 46 and 47 similar to the boxes 40 and 42 and a box 48 constituting an accommodating shelf, as shown in FIGS. 2 through 5, and is formed at its lower portion with a plurality of vent holes 49. These boxes are also formed to be projected outwardly. It is noted that the boxes 46 and 47 can be also used for installation of devices which cannot be accommodated within the boxes 40 and 42 on the front panel 31 or can be used as arranging shelves. The right side panel 33 has a shelt 52 for accommodating therein a TV receiver 51, as shown in FIGS. 2 through 5, and the shelf 52 is formed to be projected inwardly. The left side panel 34 is formed with an inclined portion 53 which is useful as a backrest when a user rests in the bedroom cabinet, as shown in FIGS. 2, 4 and 5, and a cushion 54 is stuck to the surface of the inclined portion. The ceiling panel 35 has for example expanded styrol and urethane laminated to provide sound-proofing effect. The ceiling panel 35 is formed with a number of vent holes 55 in a suitably spaced relation. Finally, the bottom panel 36 is formed with a rim 57 used to fix a mat 56, as shown in FIGS. 2, 3 and 5. The box 48 of the back panel 32 is provided with a plurality of shelt plates 58 and an accommodating section with a door 59 that may be used for a locker or the like. Of course, this box 48 can be used as a mere box with the shelf plates 58 and the door 59 removed.
While adjacent end edges of each of the panels 31 to 36 are connected and fixed by seals 60, it should be noted that the seal 60 is not always necessary but a fit-in type groove can be formed in each end edge so that they are connected by said groove.
Next, assembling of the bedroom cabinet will be described. First, the lower half of the inner casing composed of the panels 31 to 36 connected and fixed as described above is received into the lower outer casing 12. It is of course at this time that the inner casing is fitted into the lower outer casing 12 in such a way that the notch portion 23 of the front portion 12 of the lower outer casing 12 is registered with the lower half of the opening 37 of the front panel 31. Next, the upper outer casing 12 is fitted in such a way that the notch portion 18 thereof is registered with the upper half of the opening 37 of the front panel 31, and the flange 26 is brought into abutment with the flange 27 of the lower upper casing 12. These two flanges 26 and 27 are resiliently held by a clip member 61 formed from a resilient metal plate, as shown in FIG. 6 in detail. Preferably, a recess 62 is formed in portions of the flanges 26 and 27 held by the clip member 61 to prevent the clip member 61 from being deviated in a lateral direction. An ornamental web 63 formed of an expansible material such as rubber or synthetic resin is wound so as to cover the flanges 26 and 27. This web 63 is formed at its inner surface with an escape groove 64 for the flanges 26 and 27, and on both ends thereof are mounted hooks 65 to be engaged with the end edge of the exit 17. The hook 65 is secured to be web 63 by inserting and locking a screw 67 to a stop plate 66 provided on the rear surface of the end of the web 63 therethrough. The exit 17 with which the hook 65 is engaged by superposition of the notches 18 and 23 of the upper and lower outer casings 11 and 12 and the opening 37 of the front panel 31, and an edge frame 68 formed of an elastic material is mounted so as to bridge over both peripheral edges of the notches 18, 23 and opening 37. Thus, the hook 65 is passed over the edge frame 68.
Articles such as a TV receiver 51 are mounted within the thus assembled bedroom cabinet. In this case, if various electric devices such as a TV receiver 51, an interphone 39 and the like are mounted under the condition that the inner casing is fitted and fixed within the lower outer casing 12, wiring work to the outside of the inner casing can be achieved easily.
As shown in FIGS. 2 to 5, in the above-described embodiment, a sheet 71 to cover the mat 36 is in the form of a web in which both ends thereof are wound by winding rollers 72 and 73, a dirty sheet 71 can be wound on one roller by rotating the winding rollers 72 and 73 in one direction. The sheet 71 is pressed against the mat by keep members 74 and 75 provided in the neighbourhood of each of the winding rollers 72 and 73.
Next, a second embodiment of the bedroom cabinet of the present invention shown in FIGS. 7 through 9 will be described. The same elements in this embodiment as those in the above-described first embodiment bear the same reference numeral, the details of which will not be described. In the second embodiment, the desired clearance over the approximately entire portion is provided between the upper and lower outer casings 11, 12 and the inner casing composed of six panels 31 to 36.
That is, the upper and lower outer casings 11 and 12 are formed to be somewhat large or the inner casing is formed to be somewhat small, whereby a clearance over the approximately entire portion can be formed between the outer casings 11, 12 and the inner casing. Spacer members 77 each having a vent groove 76 are interposed and locked between the inner surfaces of the upper and lower outer casings 11, 12 and the panels 31 to 36 opposed to the upper and lower inner surfaces thereof. The spacer member 77 can be different in strength depending on the position disposed. That is, the spacer member 77 interposed between the lower surface 19 of the lower outer casing 12 and the bottom panel 36 is subjected to the approximately entire load of six panels 31 to 36, loads of various devices provided and the user's weight, and therefore, it is formed of a material having a great strength. On the other hand, the spacer member 77 interposed between the upper surface 13 of the upper outer casing 11 and the ceiling panel 35 can be supported under the condition that the celing panel 35 is suspended to maintain its clearance, and therefore, a small strength thereof will suffice. Further the spacer members 77 respectively interposed between the side, front and back surfaces of the outer casings 11, 12 and the side panels 33, 34, the front panel 31 and the back panel 32 may have an intermediate strength between the spacer member between the uper surface portion 13 and the ceiling panel 35, and the spacer member between the lower surface portion 19 and the bottom panel 36.
As described above, in the second embodiment, a spacer member 77 having the required strength is interposed between the outer casings 11, 12 and the interior body to form a clearance in communication as a whole. This clearance acts as an intake and exhaust passage in communication with the vent hole 49 and with the vent hole 55 of the ceiling panel 35 and also serves as a sound-proofing wall. In this second embodiment, an inclined portion 53 is provided on the right side panel 33 and a box 52 for a TV receiver is provided on the left side panel 34. An illuminating device 38, an interphone 39 and a device 41 are mounted on the boxes 46 47 of the back panel 32. | A bedroom cabinet having a floor area at least approximately equal to an area of a bed and a height such that a user can erect the upper half of his body on the bed. This cabinet is composed of two layers, that is, an outer casing and an inner casing, the outer casing being divided into an upper casing and a lower casing, and a recess serving as an accommodating shelf for electric devices and a user's belongings is provided in the side wall of the inner casing so as to be projected outwardly. This projection of the recess is projected into a clearance between the outer casing and the inner casing, and the projection of the recess is formed so as not to be further projected from the outer periphery of the outer casing, the clearance being used as a wiring passage for electric devices and as vent passage for ventilation. | big_patent |
FIELD OF THE INVENTION
[0001] The present invention relates to a portable, temporary guard rail support and, more particularly, to a novel guard rail support for use in the erection of a safety barrier or fence at sites under construction such as office buildings, high rise apartments or the like.
BACKGROUND TO THE INVENTION
[0002] Modern construction techniques, particularly those commonly employed in high rise apartment and office building construction, require that safety barriers or guard rails be erected around the perimeter of all uncompleted floors (i.e. along the drop-off edges of concrete floor slabs) for two reasons: Firstly, personal safety requires the erection of at least a single rail at about waist height around the exterior of such uncompleted floors. Secondly, it is also necessary that a retaining kick board be erected at floor level so as to prevent the accidental dislodgement of articles which would otherwise cause a substantial safety hazard to workmen on the floors below and around the construction site. In certain cases, the provision of a weather barrier, such as a plastic tarpaulin or the like, may be necessary so as to protect the site under construction as well as workmen from inclement weather conditions.
[0003] The general practice in the erection of such safety barriers involves the use of lengths of lumber stock such as long boards of the 2″×4″ variety (commonly referred to as “two-by-fours”). Such boards are cut to length and then nailed together in varying patterns in order to provide the desired guard railings. After such railings have served their purpose they are knocked down, the longer boards typically reserved for future use in the piecing together of future guard railings. The shorter boards are not always reusable. Furthermore, the longer lengths of lumber frequently become damaged by splitting or otherwise due to the application thereto of repeated impact blows and different nail placements. While such makeshift such guard railings meet safety requirements, they require more than one person and a fair amount of time to construct and often result in the destruction of the materials used when they are disassembled after completion of work at a construction site. Obviously, the additional labour and cost of materials used will add to the expense of the job. Many such railings also fail to pass the rigidity requirements of safety inspectors.
[0004] As a result, various structures have been proposed to aid in the construction of temporary safety barriers which prevent workmen from accidental falls and which meet strict safety guidelines. To a large extent, however, most of the proposed structures are impractical, expensive and too complicated to use. Furthermore, structures that are too complicated to use will not be used efficiently and/or properly by workmen at a construction site, thereby posing a safety risk.
[0005] Consequently, a need exists for a portable and simple guard rail system which is effective in preventing accidental falls, meets safety guidelines and which can be assembled and disassembled in an efficient manner.
SUMMARY OF THE INVENTION
[0006] A portable guard rail support and assembly for use in erecting a safety barrier to provide a safe work area for workmen working at dangerous heights, particularly in the construction industry, is provided.
[0007] In accordance with a first aspect of the present invention, a guard rail support for use in erecting a temporary safety barrier is provided wherein the guard rail support comprises a substantially flat bottomed base plate, an upright column affixed to the flat bottomed base plate, at least one guard rail support bracket affixed to the upright column, a kick board retaining flange affixed to the flat bottomed base plate in spaced proximal relationship to the upright column, an angular brace affixed to the upright column and the flat bottomed base plate and a safety tie-off ring affixed to the upright column and the flat bottomed base plate.
[0008] In accordance with a further aspect of the present invention, a concrete-filled steel base is also provided that is adapted to receive the portable guard rail support in circumstances where anchoring of the portable guard rail support to a floor or ground surface is not possible. The concrete-filled steel base has a retaining groove formed in a bottom surface thereof for slidably receiving the substantially flat bottomed base plate of the portable guard rail support. The steel base further comprises a channel integrally formed therein extending from a top surface of the steel base to the retaining groove and wherein the channel is in perpendicular relation to the retaining groove and dimensioned so as to be able to receive at least one kick-board.
[0009] In accordance with another aspect of the present invention, a portable safety barrier for use about a drop-off edge of a floor surface is provided comprising at least first and second portable guard rail supports located in spaced relation to one another along the drop-off edge and wherein each of the at least first and second portable guard rail supports comprises a substantially flat bottomed base plate, an upright column affixed to the substantially flat bottomed base plate, at least one guard rail support bracket affixed to the upright column, a kick board retaining flange affixed to the substantially flat base plate in spaced proximal relationship with the upright column, an angular brace affixed to the upright column and the substantially flat bottomed base plate, a safety tie-off ring affixed to the upright column and the substantially flat bottomed base plate, and wherein the at least one guard rail support bracket and the retaining flange of the at least first and second portable guard rail supports fixedly retain guard rails and kick boards.
[0010] Other aspects and features of the present invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] A better understanding of the invention will be obtained by considering the detailed description below, with reference to the following drawings in which:
[0012] FIG. 1 is a front perspective view of a portable guard rail support in accordance with the present invention.
[0013] FIG. 2 illustrates a rear perspective view of the portable guard rail support according to FIG. 1 .
[0014] FIG. 3 is a side view of the portable guard rail support according to FIG. 1 .
[0015] FIG. 4 depicts a portion of a safety barrier constructed with overlapping wooden guard rails in accordance with a preferred embodiment of the present invention.
[0016] FIG. 5 depicts a portion of a safety barrier constructed with wooden guard rails in accordance with another embodiment of the present invention.
[0017] FIG. 6 is a perspective view of a portable guard rail support having a concrete-filled steel base in accordance with an alternate embodiment of the present invention.
[0018] FIG. 7 depicts a portion of a safety barrier constructed with a safety mesh in accordance with a further aspect of the present invention.
DETAILED DESCRIPTION
[0019] Throughout the following detailed description, the same reference numerals are used to denote the same features in all of the drawings.
[0020] FIGS. 1 and 2 depict front and rear isometric views, respectively, of a guard rail support 10 according to a preferred aspect of the present invention. The guard rail support 10 consists of a rectangular upright column 12 , the lower end of which is affixed to a substantially flat rectangular metallic base plate 14 in a central symmetric axis thereof. The flat base plate 14 is provided with at least two bores or holes 24 a and 24 b for receiving suitable fastening means (not shown) in order to anchor or secure the guard rail support 10 to a floor or ground surface (not shown). In a preferred embodiment, the fastening means comprises expansion anchors well known to those skilled in the art. However, any suitable fastening means (e.g. screws) may be used. First and second L-shaped rail supporting brackets 16 are affixed one above the other to the upright column 12 as shown to provide supporting means for wooden guard rails (not shown). A retaining flange 17 , spaced apart from the upright column 12 , is affixed to the baseplate 14 of the guard rail support 10 in order to receive and secure a kick board (not shown) in position. The rail supporting brackets 16 and the retaining flange 17 have bores 19 formed therein for receiving fasteners to secure wooden guard rails within the rail supporting brackets 16 and the retaining flange 17 . An angle brace 20 is affixed between the upright column 12 and the base plate 14 in the manner shown to provide for structural stability of the guard rail support 10 . Finally, a fall protection (or safety) tie-off ring 22 is affixed to the lower end of the upright column 12 and to the base plate 14 .
[0021] Preferably, the L-shaped rail supporting brackets 16 and retaining flange member 17 are dimensioned to accommodate two adjacent, overlapping wooden rails which may be secured to each other and within the brackets 16 and retaining flange 17 by suitable fastening means such as nailing or the like. In a preferred embodiment, the wooden rails would be comprised of stock lumber such as lengths of two-by-four (2×4). In this case, the brackets would be dimensioned so as to accommodate two 2×4's i.e. a width, 2 w, of 4 inches and a height, h, of at least 4 inches. Thus, it may be seen that the rail supporting brackets 16 and retaining flange 17 may be dimensioned in any appropriate manner, 2 w×h, to accommodate any size, w×h, of stock lumber desired.
[0022] In order to implement a guard rail assembly (safety barrier) at a construction site according to a first aspect of the invention, a plurality of guard rail supports 10 are located at set distances apart (preferably slightly less than the length of stock lumber to be used for the guard rails) along the outer edge or perimeter of a floor undergoing construction. The guard rail supports 10 are secured to the floor via suitable fasteners driven through the bores 24 a , 24 b formed in the base plate 14 of each guard rail support 10 . Lengths of stock lumber (at least spanning the distance between the corresponding rail supporting brackets 16 and retaining flanges 17 of consecutively aligned guard rail supports 10 ) may then be positioned and secured within the corresponding rail supporting brackets 16 and retaining flanges 17 of adjacent guard rail supports 10 so as to form a guard rail assembly (safety barrier) consisting of upper and lower wooden guard rails and a kick board. The configuration of such a guard rail assembly is discussed further in relation to FIG. 4 .
[0023] As seen in FIGS. 1 and 2 , the fall protection tie-off (safety) ring 22 has the preferred shape of a sideways “U” with one end portion affixed to the lower end of the upright column 12 and the other end affixed to the base of the upright column 12 and the flat base plate 14 . The fall protection tie-off ring 22 provides for numerous advantages. Firstly, the fall protection tie-off ring 22 may serve as retaining and attachment means for a safety cable which is frequently used by workers at sites undergoing construction. In this respect, a continuous safety cable may be run through the fall protection tie-off rings 22 of consecutively aligned guard rails supports comprising a guard rail assembly (see FIG. 4 ) constructed in accordance with the present invention. A workman may then “tie off” to such a safety cable at any desired location thereby providing protection from accidental falls. Alternatively, a workman may tie off to the actual fall protection tie-off ring 22 of an individual guard rail support 10 , if desired. Secondly, the fall protection tie-off rings 22 of individual guard rail supports 10 comprising a guard rail assembly may be used to fasten weatherproof tarpaulins or the like (not shown) to protect workmen and the site under construction from inclement weather conditions.
[0024] FIG. 3 is a side view of the guard rail support 10 in FIGS. 1 and 2 wherein like features are denoted by like numerals.
[0025] FIG. 4 depicts a portion of a guard rail assembly or safety barrier 40 assembled along the perimeter of a floor 33 under construction in accordance with one aspect of the present invention. In FIG. 4 , first and second guard rail supports 10 a and 10 b are located at a set distance d apart and secured along an outer floor edge 34 via expansion anchors 31 driven through the corresponding bores 24 a , 24 b of each guard rail support 10 a , 10 b into the floor 33 . Upper and lower wooden rails 36 a and 37 a , (e.g. suitable lengths of 2×4) span at least the distance between corresponding rail supporting brackets 16 on the guard rail supports 10 a , 10 b . Similarly, kick board 39 a spans at least the distance between the retaining flanges 17 on the guard rail supports 10 a , 10 b . In a preferred embodiment, the distance d between guard rail supports 10 a and 10 b is slightly less than the lengths of 2×4 comprising the wooden rails such that the upper and lower wooden rails 36 a , 37 a and kick board 39 a will have some overshoot at each rail supporting bracket 16 or retaining flange 17 .
[0026] Considering guard rail support 10 a , upper and lower wooden rails 36 a , 37 a and kick board 39 a are secured with overlapping wooden rails 36 b , 37 b and 39 b within the corresponding rail supporting brackets 16 and retaining flange 17 via suitable fasteners 23 placed through bores 19 . Suitable fasteners 23 may include nails, screws, rivets or the like. Similarly, upper and lower wooden rails 36 a , 37 a and kick board 39 a are secured with overlapping wooden rails 36 c , 37 c and 39 c within the corresponding rail supporting brackets 16 and retaining flange 17 of guard rail support 10 b via suitable fasteners 23 placed through corresponding bores 19 . As shown, the left end of upper wooden rail 36 a overlaps with the right end of upper wooden rail 36 b at the uppermost rail supporting bracket 16 of the first guard rail support 10 a . Similarly, the right end of upper wooden rail 36 a overlaps with the left end of upper wooden rail 36 c at the uppermost rail supporting bracket 16 of the second guard rail support 10 b . It should be understood that the configuration described above for the upper wooden rails 36 holds for lower wooden rails 37 and kick boards 39 . It will further be appreciated that upper wooden rails 36 b and 36 c , lower wooden rails 37 b and 37 c and kick board 39 b and 39 c span the distance to other respective guard rail supports 10 (not shown) and may be secured within the corresponding rail supporting brackets and retaining flanges of the other guard rail supports 10 in the same manner as described above.
[0027] In cases where it is not desired or possible to use the overlapping wooden rail scheme depicted in FIG. 4 , for whatever reason, an alternative configuration may be used at each guard rail support 10 of the present invention to construct a safety barrier 50 as shown in FIG. 5 . In this case, a short stub 35 of the same stock lumber used for the wooden guard rails (e.g. 2×4) may be used at the rail supporting brackets 16 and retaining flange 17 of each guard rail support 10 in order to firmly secure the upper and lower wooden guard rails 36 , 37 and kickboard 39 in place. As before, at the rail supporting brackets 16 and retaining flange 17 of each guard rail support 10 , the upper and lower wooden rails 36 , 37 and kick board 39 may be secured to their corresponding short wooden stubs 35 and to the rail supporting brackets 16 and flanges 17 via suitable fasteners 23 such as nails or the like.
[0028] It will further be appreciated that the safety barrier configuration 50 depicted in FIG. 5 also represents the configuration present at the guard rail supports defining the ends of the safety barrier 40 constructed in accordance with the embodiment of FIG. 4 . As can be envisioned, at each guard rail support defining an end of the safety barrier 40 , there will be no overlapping wooden rail scheme at the rail supporting brackets 16 and retaining flange 17 . Thus, short stubs of stock lumber (preferably of the same type used for the wooden rails) will be needed to firmly secure the wooden rails within their respective brackets and retaining flanges.
[0029] FIG. 6 depicts a guard rail support 60 in accordance with a further aspect of the present invention. Again, like numerals are used to denote like features with the guard rail support 10 of FIGS. 1 and 2 . As can be seen, the guard rail support 60 comprises the guard rail support 10 of FIGS. 1 and 2 , slidably received within a concrete-filled steel base 68 . The steel base 68 provides for greater stability and adequate support in cases where it is not possible, for whatever reason, to secure the base plate 14 of the guard rail support 10 to a floor surface via fasteners (e.g. expansion anchors or screws) placed through holes 24 a , 24 b . As shown, the concrete-filled steel base 68 is constructed so as to have a groove formed on the bottom surface thereof for slidably receiving the base plate 14 of the guard rail support 10 . The groove extends to an open end 66 of the steel base 68 in order to provide means for allowing the guard rail support 10 to slide into the steel base 68 . It will be appreciated that the groove terminates before reaching an opposite end 69 of the steel base 68 such that the guard rail support 10 may only be slidably received within and removed from the steel base 68 at the open end 66 .
[0030] The concrete-filled steel base 68 has a first channel or cavity 67 formed along its central longitudinal axis and dimensioned accordingly to receive angular brace 20 , retaining flange 17 and tie-off ring 22 of the guard rail support 10 . Furthermore, the steel base 68 has a pass-through channel or cavity 64 formed therein proximal the flange 17 and dimensioned to correspond to the distance between the flange 17 and the upright column 12 . The pass-through cavity 64 advantageously provides for pass-through of kick board rails (not shown), as appropriate.
[0031] In the embodiment of FIG. 6 , the guard rail support 10 is securely maintained within the concrete-filled steel base 68 due to the precise tongue-groove type of fitting of the base plate 14 within the groove and the weight of the steel base 68 . Advantageously, the substantial weight afforded by the concrete-filled base 68 provides the necessary stability and support to maintain the guard rail support 10 in a fixed and upright position. It will be appreciated that a resilient, non-slip pad 63 may also be fastened by suitable adhesive means to the underside of the concrete-filled steel base 68 to provide a frictional wear resistant non-slip surface for contacting and engaging a floor surface. A plurality of such guard rail supports 60 may then be located along the outer edge of a floor under construction and a safety barrier constructed in the manner shown by either of FIG. 4 or 5 .
[0032] In accordance with a further aspect of the present invention, a mesh-like fence structure may be used in conjunction with any of the guard rail supports 10 or 60 described in relation to FIGS. 1 and 2 or 6 to form a mesh-like (or fence) safety barrier at any desired site under construction. For example, a portion of a fence-like safety barrier 79 constructed in accordance with the present invention is depicted in FIG. 7 . Again, like features are denoted by like numerals. As shown, a framed mesh 80 includes three projecting U-beams 78 affixed to opposite vertical sides thereof. The U-beams 78 are preferably made of metal and are supported and secured within the rail supporting brackets 16 and retaining flanges 17 of the guard rails supports 10 a , 10 b in the same overlapping manner as described in relation to FIG. 4 . In this case, however, holes corresponding to the holes 19 of the rail supporting brackets 16 and retaining flanges 17 are pre-drilled into each U-beam. In this manner, two overlapping U-beams may be placed within the rail supporting brackets 16 and retaining flanges 17 of each guard rail support 10 and secured with suitable fasteners. Thus, in this particular embodiment, the rail supporting brackets 16 and retaining flange 17 of each guard rail support 10 are dimensioned so as to accommodate two adjacent and overlapping U-beams. It will be appreciated that the mesh-like structure 80 of FIG. 7 need not include three U-beams projecting from each side, as shown. Two projecting U-beams may provide for sufficient stability and support. In this case, a single rail supporting bracket along with the retaining flange would be used, as required.
[0033] The guard rail supports 10 , 60 of the present invention each have two rail supporting brackets 16 affixed to their upright column 12 and a single retaining flange 17 affixed to their base plate 14 for supporting upper and lower wooden rails and kick boards, respectively. Although the retaining flange 17 on each guard rail support is a necessary requirement for supporting kick boards in accordance with safety standards and regulations, it will be appreciated that the precise number of rail supporting brackets 16 affixed to the upright column 12 of a given guard rail support is not material to the invention. Those skilled in the art will appreciate that construction safety regulations in most jurisdictions require guard rail systems of the type described to have a top rail, an intermediate rail and a toe or kick board as a minimum. Thus, at least two rail supporting brackets (for supporting upper and lower wooden guard rails) and a retaining flange (for supporting the kick board) are provided in the guard rail support of the present invention in order to adhere to safety regulations. However, more than two rail supporting brackets for supporting more than two rails in addition to the kick board may be employed in alternative embodiments without departing from the scope of the invention.
[0034] In addition, it will be appreciated that safety regulations in most jurisdictions require that the top rail of a guard rail barrier be located at least 3 feet but not more than 3.5 feet above the floor or ground surface to which the guard rail barrier is to be anchored while the intermediate rail be midway between the top rail and the floor surface. Thus, in a preferred embodiment of the present invention, the rail supporting brackets 16 are spaced along the upright column 12 of the guard rail support 10 , 60 in such a manner so as to adhere to the above-prescribed safety regulations when fitted with upper and lower rails. In addition, safety regulations generally dictate that the top and intermediate rails be at least 1.5 inches by 3.5 inches in dimension and that the kick board be at least 3.5 inches in height. Advantageously, the rail supporting brackets 16 and retaining flange 17 of the guard rail support 10 , 60 of the present invention are preferably dimensioned so as to accommodate 2″×4″ wooden rails, thereby conforming to safety regulations. It will be appreciated, however, that the rail supporting brackets and retaining flange may be dimensioned in any appropriate manner that meets the minimum safety guidelines in the jurisdiction of concern.
[0035] To further comply with safety regulations, it will be appreciated that the spacing between guard rail supports of the present invention when used in the construction of a safety barrier as described should not exceed approximately 8 feet. With regard to safety line anchorage points, most safety regulations specify that the anchorage must be capable of supporting a static load on the order of 17.8 kN (or 4000 lbs) in any direction, with proper provision to accept a safety line connection. Advantageously, the safety tie-off ring 22 of the guard rail support 10 , 60 of the present invention has been tested to support a static load of 5000 lbs.
[0036] A guard rail system constructed with the guard rail support of the present invention provides for easy installation at, and removal from, sites under construction. As will be appreciated, installation may be accomplished by a single worker, if necessary. A first step in the installation procedure is to locate a plurality of supports 10 at spaced intervals up to eight feet long about the perimeter of a ground surface under construction and to attach the baseplate of each support to the ground surface using suitable fasteners or anchors. Once a series of supports according to the present invention are located and secured to the floor of a building under construction, the upper and lower safety rails may be individually placed and secured within the brackets of adjacent supports in the manner shown in FIG. 4 , so that the rails extend completely about the perimeter of a floor under construction. Thus, the assembly of a safety guard rail fence or barrier, together with kick boards may be quickly mounted in place. An advantage of the preferred embodiment is that each support may be attached to the floor of an existing building structure prior to insertion of the wooden rails or safety fences, thereby minimizing weight and bulk so that a single worker may install a guard rail assembly without assistance from another worker. Additionally, once construction is completed, the disassembly of such a guard rail assembly as well as the removal of the guard rail supports, may also be carried our in an efficient manner.
[0037] Advantageously, the guard rail support and associated guard rail assembly of the present invention reduces or eliminates the liability which may result from inadequately re-installed guard rails. Specifically, at sites under construction, workmen sometimes need to temporarily remove portions of a guard rail in order to gain access to certain regions. With prior art conventional wooden rail assemblies, the workmen typically just hammer out the appropriate section when required. Inherently lazy, however, workmen do not usually return the guard rails back to their original state, thereby compromising the integrity of the guard rail assembly and causing safety concerns. The guard rail support 10 of the present invention provides for a fast and efficient disassembling and reassembling of a portion of a guard rail assembly if need be. Furthermore, by preventing the damage of lumber which would ordinarily result from such crude hammering out, the inventive guard rail support prevents the possible reassembly of a hammered out portion of a guard rail assembly with damaged lumber. The all-steel construction of the guard rail support of the present invention also ensures durability and repeated use for many years, thereby providing a high return on investment and cost savings.
[0038] The temporary guard rail support and associated assembly of the present invention have been described in connection with the provision of a safety guard rail along the outer drop-off edge or perimeter of a concrete floor slab which defines an upper story level of a building while it is under construction; the principle purpose being to protect workmen on the floor slab from falls. It will be appreciated, however, that the guard rail support and assembly may be useful in other embodiments and a guard rail support embodying the principles of the invention may, if desired and with or without modification as required, be employed for guard rail support purposes in a wide variety of other situations or environments as, for example, in the provision of a temporary guard railing around the perimeter of a roof structure, along the sides of a bridge construction until such time as the permanent guard railings are installed, or along any drop-off edge wherever it may occur.
[0039] While preferred embodiments have been described and illustrated, it will be apparent to one skilled in the art that numerous modifications, variations and adaptations may be made without departing from the scope of the invention as defined in the claims appended hereto. | A guard rail support and assembly is disclosed for use in providing a safe work area for workmen working at dangerous heights, particularly in the construction industry. The guard rail support assembly comprises a plurality of guard rail supports arranged in a spaced fashion and wooden guard rails extending between and attached on either end to each support. Each guard rail support comprises an attachment base having quick fastening means for quick attachment and release of the support to a ground surface of the site under construction, a plurality of rail supports having quick fastening means for quick attachment and release of the wooden guard rails and a fall-protection or tarp tie-off ring. Advantageously, a portable and lightweight guard rail assembly may be constructed with the guard rail supports in an expedient and efficient manner to provide safe, unobstructive protection against falls. | big_patent |
CROSS REFERENCES TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of U.S. patent application Ser. No. 09/500,669 filed on Feb. 9, 2000, now U.S. Pat. No. ______.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention pertains to the stimulation of crude oil reservoirs to enhance production using a combination of pulsed power electrohydraulic and electromagnetic methods and the processing of the recovered crude oil into its components. In particular, the present invention provides a method and apparatus for recovery of crude oil from oil bearing soils and rock formations using pulsed power electrohydraulic and electromagnetic discharges in one or more wells that produce acoustic and coupled electromagnetic-acoustic vibrations that can cause oil flow to be enhanced and increase the estimated ultimate recovery from reservoirs.
BACKGROUND OF THE INVENTION
[0004] The stimulation of crude oil reservoirs to enhance oil production from known fields is a major area of interest for the petroleum industry. One of the single most important research goals in fossil fuels is to recover more of the hydrocarbons already found. At present, approximately 66% of discovered oil is left in the ground due to the lack of effective extraction technology for secondary and tertiary Enhanced Oil Recovery (EOR). A EOR technology that can be deployed easily and at low cost in onshore and offshore field locations would greatly improve the performance of many oil fields and would increase significantly the world's known recoverable oil reserves.
[0005] Methods that are widely used for the purpose rely on the injection of fluid at one well, called the injection well, and use of the injected fluid to flush the in situ hydrocarbons out of the formation to a producing well. In one mode of secondary recovery, a gas such as CO 2 that may be readily available and inexpensive, is used. In other modes, water or, in the case of heavy oil, steam may be used to increase the recovery of hydrocarbons. One common feature of such injection methods is that once the injected fluid attains a continuous phase between the injection well and the production well, efficiency of the recovery drops substantially and the injected fluid is unable to flush out any remaining hydrocarbons trapped within the pore spaces of the reservoir. Addition of surfactants has been used with some success, but at high cost, both economic and environmental.
[0006] Many methods have been developed that try address the problem of driving out the residual oil. They can be divided into a number of broad categories.
[0007] The first category uses electrical methods. For example, U.S. Pat. No. 2,799,641 issued to Bell discloses a method for enhancing oil flow through electrolytic means. The method uses direct current to stimulate an area around a well, and uses the well-documented effect known as electro-osmosis to enhance oil recovery. Another example of electro-osmosis is described in U.S. Pat. No. 4,466,484 issued to Kermabon wherein direct current only is used to stimulate a reservoir. U.S. Pat. No. 3,507,330 issued to Gill discloses a method for stimulating the near-wellbore volume using electricity passed upwards and downwards in the well using separate sets of electrodes. U.S. Pat. No. 3,874,450 issued to Kern teaches a method for dispersing an electric current in a subsurface formation by means of an electrolyte using a specific arrangement of electrodes. Whitting (U.S. Pat. No. 4,084,638) uses high-voltage pulsed currents in two wells, a producer and an injector, to stimulate an oil-bearing formation. It also describes equipment for achieving these electrical pulses.
[0008] A second category relies on the use of heating of the formation. U.S. Pat. No. 3,141,099 issued to Brandon teaches a device installed at the bottom of a well that causes resistive heating in the formation though dielectric or arc heating methods. This method is only effective within very close proximity to the well. Another example of the use of heating a petroleum bearing formation is disclosed in U.S. Pat. No. 3,920,072 to Kern.
[0009] A third category of methods relies on mechanical fracturing of the formation. An example is disclosed in U.S. Pat. No. 3,169,577 to Sarapuu wherein subsurface electrodes are used to cause electric impulses that induce flow between wells. The method is designed to create fissures or fractures in the near-wellbore volume that effectively increase the drainage area of the well, and also heat the hydrocarbons near the well so that oil viscosity is reduced and recovery is enhanced.
[0010] It has long been documented that acoustic waves can act on oil-bearing reservoirs to enhance oil production and total oil recovery. A fourth category of methods used for EOR rely on vibratory or sonic waves, possibly in conjunction with other methods. U.S. Pat. No. 3,378,075 to Bodine discloses a method for inducing sonic pumping in a well using a high-frequency sonic vibrator. Although the sonic energy generated by this method is absorbed rapidly in the near wellbore volume, it does have the effect of cleaning or sonicating the pores and fractures in the near-wellbore area and can reduce hydraulic friction in the oil flowing to the well. Another example of a vibratory only technique is disclosed by U.S. Pat. No. 4,049,053 to Fisher et al. wherein several low-frequency vibrators are installed in the well and are driven hydraulically using surface equipment. U.S. Pat. No. 4,437,518 issued to Williams describes the design for a piezoelectric vibrator that can be used to stimulate a petroleum reservoir. U.S. Pat. No. 4,471,838 issued to Bodine teaches a method for using surface vibrations to stimulate oil production. The surface source defined in this patent is not sufficient to produce significant enhanced recovery of crude oil.
[0011] Turning next to methods that use vibratory or sonic waves in conjunction with other methods, U.S. Pat. No. 3,754,598 to Holloway, Jr. discloses a method that utilizes at least one injector well and another production well. The method imposes oscillating pressure waves from the injector well on a fluid that is injected to enhance oil production from the producing well. U.S. Pat. No. 2,670,801 issued to Sherborne discloses the use of sonic or supersonic vibrations in conjunction with fluid injection methods: the efficiency of the injected fluids in extracting additional oil from the formation is improved by the use of the acoustic waves. U.S. Pat. No. 3,952,800, also to Bodine teaches a sonic treatment in which a gas is injected into the well and is used to treat the wellbore surface using sonic wave stimulation. The method causes the formation to be heated through the gas by heating from the ultrasonic vibrations. U.S. Pat. No. 4,884,634 issued to Ellingsen uses vibrations of an appropriate frequency at or near the natural frequency of the formation to cause the adhesive forces between the formation and the oil to break down. The method calls for a metallic liquid (mercury) to be placed in the wells to the level of the reservoir and the liquid is vibrated while also using electrodes placed in the wells to electrically stimulate the formation. Apart from the potential environmental hazards associated with the handling and containment of mercury, this method faces the problem of avoiding formation damage due to an excess of borehole pressure over the formation fluid pressure caused by the presence of a dense liquid. U.S. Pat. No. 5,282,508, also issued to Ellingsen et al. defines an acoustic and electrical method for reservoir stimulation that excites resonant modes in the formation using AC and/or DC currents along with sonic treatment. The method uses low frequency electrical stimulation.
[0012] The success of the existing art in stimulating reservoirs has been spotty at best, and the effective range of such methods has been limited to less than 1000 feet from the stimulation source. A good discussion on wettability, permeability, capillary forces and adhesive and cohesive forces in reservoirs is provided by the Ellingsen '508 patent. These discussions fairly represent the state of knowledge on these subjects and are not repeated herein. These discussions do not, however, address the limitations on the current state of the art in acoustic stimulation.
[0013] Existing acoustic stimulation methods have demonstrated clearly that they are limited to a range of about 1000 feet from the stimulation point. This limit is caused by the natural attenuation properties of the reservoir, which absorb high frequencies preferentially and reduce the effective frequency range to less than a few hundred Hertz at distances beyond about 1000 feet from the acoustic source. This same limit has plagued seismic imaging in cross-borehole studies for many years and is a fundamental physical limitation on all acoustic methods.
[0014] Effective acoustic stimulation of oil-bearing reservoirs requires support at greater distances from the stimulation source than possible with most of the prior art. In addition, there is some empirical evidence suggesting that higher frequencies than direct acoustic methods can generate may be more effective in stimulation of oil-bearing reservoirs. Accordingly, it is desirable to have a stimulation source that has a greater range of effectiveness than the prior art discussed above. Such a source should preferably be able to provide stimulation at higher frequencies than the 10-500 Hz typically attainable using prior art methods.
[0015] U.S. Pat. No. 4,345,650 issued to Wesley teaches a device for electrohydraulic recovery of crude oil using by means of an electrohydraulic spark discharge generated in the producing formation in a well. This method presents an elegant apparatus that can be placed in the producing interval and can produce a shock and acoustic wave with very desirable qualities. The present invention will build on the teachings of this patent and will extend the effective range of Wesley's method through new and novel equipment designs and field configurations of Wesley's apparatus and new apparatus designed to enhance the effect on oil reservoirs.
[0016] Hydrocarbons recovered from a wellbore may include a number of components. The term “crude oil” is used to refer to hydrocarbons in liquid form. The API gravity of crude oil can range from 6° to 50° API with a viscosity range of 5 to 90,000 cp under average conditions. Condensate is a hydroacarbon that may exist in the producing formation either as a liquid or as a condensable vapor. Liquefaction of the gaseous components occurs when the temperature of the recovered hydrocarbons is lowered to typical surface conditions. Recovered hydrocarbons also include free gas that occurs in the gaseous phase under reservoir conditions, solution gas that comes out of solution from the liquid phase when the temperature is lowered, or as condensable vapor. Recovered hydrocarbons also commonly include water that may be in either liquid form or vapor (steam). The liquid water may be free or emulsified: free water reaches the surface separated from liquid hydrocarbons whereas the emulsified water may be either water dispersed as an emulsion in liquid hydrocarbons or as liquid hydrocarbons dispersed as an emulsion in water. Produced well fluids may also include gaseous impurities including nitrogen, helium and other inert gases, CO 2 , SO 2 and H 2 S. Solids present in the recovered wellbore fluids may include sulphur. Heavy metals such as chromium, vanadium or manganese may also be present in the recovered fluids from a wellbore, either as solids or in solution as salts. In all enhanced EOR operations, it is desirable to separate these and other commercially important materials from the recovered fluids.
SUMMARY OF THE INVENTION
[0017] The present invention is a pulsed power device and a method of using the pulsed power device for EOR. Pulsed power is the rapid release of electrical energy that has been stored in capacitor banks. By varying the inductance of the discharge system, energies from 1 to 100,000 Kilojoules can be released over a pulse period from 1 to 100 microseconds. The rapid discharge results in a very high power output that can be harnessed in a variety of industrial, chemical, or medical applications. The energy release from the system can be used either in a direct plasma mode through a spark gap or exploding filament, or by discharging the energy through a single- or multiple-turn coil that generates a short-lived but extremely intense magnetic field.
[0018] When electricity stored in capacitors is released across a spark gap submerged in water, a plasma channel is created that vaporizes the surrounding water. This plasma ionizes the water and generates very high pressures and temperatures as it expands outward from the discharge point. In a plasma, or electrohydraulic (EH) mode, the pulse may be used in a wide range of processes including geophysical exploration, mining and quarrying, precision demolition, machining and metal forming, treatment and purification of a wide range of fluids, ice breaking, defensive weaponry, and enhanced oil recovery which is the purpose of the present invention. The basic physics of the shock wave that is generated by the EH discharge is well understood and is documented in U.S. Pat. No. 4,345,650 issued to Wesley, and incorporated herein by reference.
[0019] In the electromagnetic (EM) mode, the coil is designed to produce controlled flux compression that can be used to generate various physical effects without the coupled effect of the EH strong acoustic wave. In both systems, however, typical systems require about 0.5 to 1 seconds to accumulate energy from standard power sources. The ratio of accumulation time to discharge time (100,000 to 1,000,000) allows the generation of pulses with several gigawatts of peak power using standard power sources.
[0020] Given the physical limitations on direct acoustic stimulation caused by attenuation in natural materials, acoustic stimulation must be generated using wide band vibrations in these materials at distances much greater than the current limitation of about 1000 feet. The present invention addresses this issue in a new and innovative way using pulsed power as the source. The Wesley '650 patent teaches a method for generating strong acoustic vibrations for reservoir stimulation that has been shown in the field to have an effective limit of about 1000 feet. What was not recognized in the Wesley teachings was that the pulsed power method also has a unique ability to generate high-frequency acoustic stimulation of the reservoir separately from the direct acoustic response of the EH shock wave generated by the plasma discharge in the wellbore. In addition to the direct shock wave effect claimed in the Wesley patent, the pulsed power discharge also generates a strong electromagnetic pulse that travels at the speed of light across the reservoir. As this electromagnetic pulse transits the reservoir, it induces a coupled acoustic vibration at very high frequencies in geologic materials like quartz that causes stimulation at multiple scales in the reservoir body. This induced acoustic vibration acts for a short period of time after the pulse is discharged, usually on the order of about 0.1 to 0.3 seconds, but is induced everywhere that the electromagnetic pulse travels. Thus, it is not limited by the natural acoustic attenuation that limits the effectiveness of a direct acoustic pulse source because it is induced at all locations in-situ by the electromagnetic pulse. At the same time, the lower-frequency direct acoustic pulse travels through the reservoir at the velocity of sound. This direct acoustic pulse assists the electromagnetically-induced vibrations in stimulating the reservoir, but has a clearly limited range due to the finite speed that it can travel before the EM-induced vibrations decay and become ineffective.
[0021] Effective acoustic stimulation of oil-bearing reservoirs requires higher frequencies than direct acoustic methods can generate and support at great distances from the stimulation source. Every rock formation can be modeled as a uniform equivalent medium with imbedded inclusions. These inclusions can be present at the pore scale, grain scale, crack scale, lamina scale, bedding scale, sand body scale, and larger scales. Each of these inclusions, or features, of the formation act as scatterers that absorb acoustic energy. The frequency of the energy absorbed is directly correlated to the scale of the inclusions and the contrast in physical properties between the inclusion and the surrounding matrix, and this absorption provides the energy for enhanced oil recovery that is required at a specific scale of inclusion. Hence, an effective acoustic stimulation program can be designed to optimize the energy absorption and effective stimulation if the scale of the inclusions and their physical properties are known, and if the acoustic stimulation frequencies can be targeted at these inclusion scales over a large volume of the reservoir. The limitations and variations in the effectiveness of existing acoustic methods are directly correlated to the narrow band of seismic frequencies from 10-500 hertz used to stimulate and whether there are inclusions at those frequencies within the effective range of the stimulation method in question. When this physical understanding of the role of acoustic absorption by scale dependent features in reservoirs is included, it becomes readily apparent why existing acoustic methods with a frequency band limited to a few hundred hertz are not capable of stimulating most reservoirs effectively. The existing technology has demonstrated a spotty record because the narrow band of frequencies used are often not the right ones for stimulating the critical inclusions of a particular reservoir. The scale of the inclusions that are critical to effective stimulation exist at the Dore scale, grain scale, flat-crack scale, and fracture scale, all of which are activated by much higher frequencies (kilohertz and higher) than the band pass of the low-frequency direct acoustic wave.
[0022] The present invention differs from all of the prior art in several ways. First, it uses a coupled process of direct EH acoustic vibrations that propagate outward into the formation from one or more wells, and electromagnetically-induced high-frequency acoustic vibrations that are generated using both EH and EM pulsed power discharge devices that takes advantage of the acoustic coupling between the electromagnetic pulse and the formation. This is significantly different from the prior art which relies on acoustic vibrations only, or a combination of acoustic vibrations and low-frequency AC or DC electrical stimulation.
[0023] The present invention also recognizes that these two effects must occur together to effectively mobilize the oil and increase production of the oil. The problem that arises is that the EM-induced vibrations only occur for a short time after the electrohydraulic or electromagnetic pulse is initiated. The electrohydraulic acoustic pulse travels at a finite speed from the well where the pulse originates, so that the effective range of the technique is defined by how far the acoustic wave can travel before the electromagnetically-induced vibration in the reservoir ceases. Hence, a single pulse source has a range that is limited by the pulse characteristics employed.
[0024] In a preferred embodiment of the present invention, the technique can be applied using a multi-level discharge device that allows sequential firing of several sources in one well in a time sequence that is optimized to allow continuous electromagnetic-coupled stimulation of a large reservoir volume while the electrohydraulic acoustic pulse travels further from the pulse well than it could before a single source electromagnetic vibration would decay. This approach can be used to extend the effective range of the stimulation by a factor of 5-6 from about 1000 feet as claimed and proven in the Wesley patent, i.e., up to distances of 5000 to 6000 feet claimed in the present invention. This allows the technique to be applied effectively to a wide range of oil fields around the world. This concept can be extended to the placement of multiple tools in multiple wells to achieve better stimulation of a specific volume of the reservoir.
[0025] In another embodiment of the invention, the range of the technique is extended by using multiple pulse sources in multiple wells that allow the electromagnetically-induced vibrations to continue for a longer time, thus allowing the acoustic pulse to travel further into the formation, effectively extending the range of coupled stimulation that can be achieved. This embodiment utilizes a time-sequential discharge pattern that produces a series of electromagnetically-induced vibrations that will last up to several seconds while the direct acoustic pulse travels further from the discharge source to interact with the electromagnetically-induced vibrations at much greater distances in the reservoir.
[0026] In another embodiment of the present invention, multiple EH and EM sources can be placed in multiple wellbores and discharged to act as an array that will stimulate production of the oil in a given direction or specific volume of the reservoir.
[0027] In another aspect of the invention, the discharge characteristics of the pulse sources can be customized to produce specific frequencies that will achieve optimal stimulation by activating specific scales of inclusions in the reservoir. In this embodiment, the discharge devices can have their inductances modified to achieve a variety of pulse durations and peak frequencies that are tuned to the specific reservoir properties. This allows for the design of a multi-spectral stimulation program that can activate those inclusions that are critical to enhanced production, while preventing activation of those inclusions that might inhibit enhanced production. Once the desired inclusions for stimulation are defined by conventional geophysical logging methods, a reservoir model is constructed and the optimal frequencies for the stimulation are determined. The pulse tool can be adapted to a wide range of pulse durations and peak frequencies by adjusting the induction of the capacitor circuits in the pulse tool. Where multiple frequencies are desired to achieve stimulation at several scales, the multi-level tool in a single well or multiple tools placed in multiple wells can be tuned to the reservoir to optimize the desired stimulation effect and produce a multi-spectral stimulation of the reservoir.
[0028] The present invention also differs from the previous art in that it includes the use of EM pulse sources that do not generate a direct acoustic shock pulse like the plasma shock effect caused by the spark gap in the electrohydraulic device defined by Wesley. These pulse sources replace the conventional spark gap discharge device defined by Wesley with a single-turn magnetic coil that produces a magnetic pulse with no acoustic pulse effect. This tool can be placed in more sensitive wells that will not tolerate the strong shock effect of an EH pulse generator. They also allow a wider range of discharge pulse durations that will extend the effective frequency range of induced vibrations that can be applied to a given reservoir.
[0029] In another embodiment of the present invention, the EH pulse source can be directed using a range of directional focusing and shaping devices that will cause the acoustic pulse to travel only in specific directions. This reflector cone allows the operator to aim the pulses from one or multiple wells so that they can effect the specific portion of the formation where stimulation is desired.
[0030] In another embodiment of the present invention, the pulse source is placed in an injector well that is being used for water injection, surfactant injection, diluent injection, or CO2 injection. The tool can be configured to operate in a rubber sleeve to isolate it, where appropriate, from the fluids being injected. The tool can be deployed in a packer assembly suspended by production tubing, and can be bathed continuously in water to maintain good coupling to the formation. Gases generated by the electrohydraulic discharge can be removed from the packer assembly by pumping water down the well and allowing the gases to be flushed back up the production tubing to maintain optimal coupling and avoid the increase in compressibility that would occur if the gases were left in the well near the discharge device.
[0031] A chronic problem with electrohydraulic discharge devices is that the electrodes are prone to wear and must be replaced from time to time. In another embodiment of the present invention, the electrodes designed for electrohydraulic stimulation have been improved using several methods including (1) improved alloys that withstand the pulse discharge better and last longer, (2) two new feeding devices for exploding filaments, one with a hollow electrode using a pencil filament, and one with a rolled filament on a spool, that allows the exploding filament to be threaded across the spark gap rapidly between discharges so that the pulse generator can operate more efficiently, and (3) gas injection through a hollow electrode that acts as a spark initiation channel.
[0032] In another embodiment of the invention, the fluids produced from the wellbore are separated into its components. These components may include one or more of associated gas, condensate, liquid hydrocarbons, helium and other noble gases, carbon dioxide, sulphur dioxide, pyrite, paraffins, heavy metals such as chromium, manganese and vanadium.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] [0033]FIG. 1 is a diagram of the basic configuration of the tool as deployed in a wellbore, including the surface equipment, winch truck and control panel, and showing the activation of various scales of the reservoir in a blow-up insert to the diagram.
[0034] [0034]FIG. 2 is a diagram showing improvements in the basic one-level tool from U.S. Pat. No. 4,345,650 of Wesley.
[0035] [0035]FIG. 3 is a diagram showing the design of a multi-level tool allowing time sequential and variable inductance discharges with both EH and EM discharge devices under user control.
[0036] [0036]FIG. 4 is a schematic diagram showing the design of a single-turn coil EM discharge device for the tool with rubber sleeve for electrical isolation
[0037] [0037]FIG. 5 is a schematic diagram showing the activation of a reservoir adjacent to the tool with a multi-level discharge device.
[0038] [0038]FIG. 6 is a schematic diagram showing the deployment of multiple tools in multiple wells to act as a source array.
[0039] [0039]FIG. 7 is a schematic diagram showing the deployment of a tool contained in a packer assembly in an injector well with tubing to feed water and electrical and control leads.
[0040] [0040]FIG. 8. is a schematic diagram showing the design of the tool incorporating a sleeve exploder configuration for non-packer applications.
[0041] [0041]FIG. 9 is a schematic diagram showing the design of the directional energy cone for the EH discharge device.
[0042] [0042]FIG. 10 is a schematic diagram showing the design of hollow EH electrodes with a pencil exploding filament device.
[0043] [0043]FIG. 11 is a schematic diagram showing the design of hollow EH electrodes with a spooled feeding device for an exploding filament.
[0044] [0044]FIG. 12 is a schematic diagram showing the design of hollow electrodes with a gas-injection device for improving electrode wear.
DETAILED DESCRIPTION OF THE INVENTION
[0045] [0045]FIG. 1 shows a wellbore 1 drilled in the subsurface of the earth penetrating formations 7 , 9 , 11 , 13 , 15 . . . . The wellbore 1 is typically filled with a drilling fluid 5 known in the art as “drilling mud.”. The sonde 21 that forms part of the present invention is conveyed downhole, in the preferred embodiment of the present invention, on an armored electrical cable, commonly called a wireline 3 .
[0046] The wireline is supported by a derrick 19 or other suitable device and may be spooled onto a drum (not shown) on a truck 25 . By suitable rotation of the drum, the downhole tool may be lowered to any desired depth in the borehole. In FIG. 1, for illustrative purposes, the downhole tool is shown as being at the depth of the formation 11 . This is commonly a hydrocarbon reservoir from which recovery of hydrocarbons is desired. An uphole power source 33 and a surface control unit 23 provide electrical power and control signals through the electrical conductors in the wireline to the sonde 21 . In FIG. 1, the sonde is depicted as generating energy pulses 35 into one of the subsurface formations.
[0047] The control unit 23 includes a power control unit 25 that controls the supply of power to the sonde 21 . The surface control unit also includes a fire control unit 27 that is used to initiate generation of the energy pulses 35 by the sonde. Another component of the surface control unit 23 is the inductance control unit 29 that controls the pulse duration of the energy pulses 35 . Yet another component of the surface control unit is the rotation control 31 that is used to control the orientation of components of the sonde 35 . The functions of the power control unit 25 , the fire control unit 27 , the inductance control unit 29 and the rotation control unit 31 are discussed below in reference to FIG. 3.
[0048] One embodiment of the invention is a tool designed for operation at a single level in a borehole. This is illustrated in FIG. 2 that is a view of the sonde 21 and the major components thereof as adapted to be lowered into the well. The basic EH sonde is an improvement over that disclosed in U.S. Pat. No. 4,345,650 issued to Wesley and the contents of which are fully incorporated here by reference.
[0049] One set of modifications relates to the use of processors wherever possible, instead of the electronic circuitry. This includes the surface control unit 23 and its components as well as in the downhole sonde.
[0050] In a preferred embodiment of the invention, the sonde 21 is used within a cased well, though it is to be understood that the present invention may also be used in an uncased well. The sonde 21 comprises an adapter 53 that is supported by a cable head adapter 55 for electrical connection to the electrical conductors of the wireline 3 . The sonde 21 includes a gyro section 57 that is used for establishing the orientation of the sonde and may additionally provide depth information to supplement any depth information obtained uphole in the truck 25 based upon rotation of the take-up spool. The operation of the gyro section 57 would be known to those versed in the art and is not discussed further. The gyro section 57 here is an improvement over the Wesley device and makes it possible to controllably produce energy pulses in selected directions.
[0051] The other main components of the sonde 21 are a power conversion and conditioning system 59 , a power storage section 63 , a discharge and inductance control section 65 , and the discharge section 67 . A connector 69 couples the power conversion and conditioning section to the power storage section 63 . The power storage section 63 , as discussed in the Wesley patent, comprises a bank of capacitors for storage of electrical energy. Electrical power is supplied at a steady and relatively low power from the surface through the wireline 3 to the sonde and the power conversion and conditioning system includes suitable circuitry for charging of the capacitors in the power storage section 63 . Timing of the discharge of the energy in the power from the power storage section 63 through the discharge section 67 is accomplished using the discharge and induction control section 65 on the basis of a signal from the fire control unit ( 27 in FIG. 1). Upon discharge of the capacitors in the power storage section 63 through the discharge section 67 energy pulses are transmitted into the formation. In one embodiment of the invention, the discharge section 67 produces EH pulses. Refinements in the design of the discharge section 67 over that disclosed in the Wesley patent are discussed below with reference to FIGS. 9 - 12 .
[0052] Turning now to FIG. 3, an embodiment of the invention suitable for use with multiple levels of energy stimulation into the formation is illustrated. The downhole portion of the apparatus comprises a plurality of sondes 121 a , 121 b , . . . 121 n . For illustrative purposes, only three sondes are shown. The coupling between two of the sondes 121 a and 121 b is illustrated in detail in the figure. Eyehooks 141 and 143 enable sonde 121 b to be suspended below sonde 121 a . This eyehook arrangement allows for a limited rotation of sonde 121 b relative to sonde 121 a . Flexible electrical leads 153 carry power and signals to the lower sonde 121 b and the eyehooks ensure that the leads 153 are not subjected to stresses that might cause them to break. The leads are carried within support post 151 in the upper sonde 121 a . A similar arrangement is used for suspending the remaining sondes.
[0053] Each of the sondes 121 a , 121 b . . . 121 n has corresponding components in the surface control unit 123 . Illustrated are power control units 125 a , 125 b . . . 125 n for power supply to the sondes; inductance control units 127 a , 127 b . . . 127 n for inductance control; rotation control units 129 a , 129 b . . . 129 n for controlling the rotation of the various sondes relative to each other about the longitudinal axes of the sondes (see rotation bearing 71 in FIG. 2); and inclination control unites 131 a , 131 b , . . . 131 n for controlling the inclination of the discharge sections (see 67 in FIG. 2) of the sondes relative to the horizontal. In addition, the surface control unit also includes a fire control and synchronization unit 135 that controls the sequence in which the different sondes 121 a , 121 b , . . . 121 n are discharged to send energy into the subsurface formations.
[0054] Turning next to FIG. 4, an EM pulse source is depicted. This is a single-turn magnetic coil that produces a magnetic pulse with no significant acoustic pulse. This tool can be placed in more sensitive wells that will not tolerate the strong shock effect of an EH pulse generator. It also allows a wider range of discharge pulse durations that will extend the effective frequency range of induced vibrations (up to 100 microseconds) that can be applied to a given reservoir.
[0055] The input electrical power is supplied by a conductor 161 . The EM discharge device comprises a cylindrical single-turn electromagnet 179 having an annular cavity 174 filled with insulation 175 . The electromagnet body is separated by rubber insulation 173 from the steel top plate 164 and the steel base plate 181 . Steel support rods 171 couple the steel top plate 164 and the steel base plate 181 . The whole is within a nonconductive housing 163 with an expansion gap between the steel base plate 183 . Optionally, provision may be made for circulating a cooling liquid between the electromagnet body 179 and the rubber insulation 173 . The electromagnet does not allow current to flow back out of the device, which results in dissipative resistive heating of the magnet from each pulse, hence the potential need for a cooling medium if rapid discharge is desired.
[0056] Turning next to FIG. 5, the different scales at which the flow of reservoir fluids in the subsurface is depicted. Depicted schematically are four energy sources 211 , 213 , 215 and 217 within a borehole 201 . Waves 200 a from source 211 are depicted as propagating into formations 221 , 223 and 225 to stimulate the flow of hydrocarbons therein. The frequency of these waves is selected to stimulate flow on the scale of bedding layers: typically, this is of the order of a few centimeters to a few meters.
[0057] The energy source 217 is shown propagating waves 200 d into the subsurface to stimulate flow of hydrocarbons from fractures 227 therein. As would be known to those versed in the art, these fractures may range in size from a few millimeters to a few centimeters. Accordingly, the frequency associated with the waves 200 d would be greater than the frequency associated with the waves 200 a.
[0058] Also shown in FIG. 5 are waves 200 b and 200 c from sources 213 and 215 are depicted as propagating into the formation to stimulate flow of hydrocarbons on the scale of grain size 229 and pore size 231 . Typical grain sizes for subsurface formations range from 0.1 mm to 2 mm. while pore sizes may range from 0.01 mm to about 0.5 mm, so that the frequency for stimulation of hydrocarbons at the grain size scale is higher than for the fractures and the frequency for stimulation of flow at the pore size level is higher still.
[0059] As would be known to those versed in the art, the discharge of a capacitor is basically determined by the inductance and resistance of the discharge path. Accordingly, one function of the inductance control units ( 27 in FIG. 1; 65 in FIG. 2; 127 a . . . 127 n in FIG. 3) in the invention is to adjust the rate of discharge (the pulse duration) and the frequency of oscillations associated with the discharge.
[0060] [0060]FIG. 6 a is a plan view of an arrangement of wells using the present invention. Shown is a producing well 253 and a number of injection wells 251 a , 251 b , 251 c . . . 251 n . Each of the wells includes a source of EH or EM energy. Shown in FIG. 6 a are the acoustic waves 255 a , 255 b . . . 255 n propagating from the injection wells in the formation towards the producing well. When sources in all the injection wells 251 a , 251 b , 251 c . . . 251 n are discharged simultaneously, then the acoustic wavefronts, depicted here by 257 a . . . 257 n propagate through the subsurface as shown and arrive at the producing well substantially simultaneously, so that the stimulation of hydrocarbon production by the different sources occurs substantially simultaneously.
[0061] One or more of the wells 251 a , 251 b , 251 c . . . 251 n may be used for water injection, surfactant injection, diluent injection, or CO2 injection using known methods. The tool can be configured to operate in a rubber sleeve to isolate it, where appropriate, from the fluids being injected. The tool can be deployed in a packer assembly suspended by production tubing, and can be bathed continuously in water to maintain good coupling to the formation. Gases generated by the electrohydraulic discharge can be removed from the packer assembly by pumping water down the well and allowing the gases to be flushed back up the production tubing to maintain optimal coupling and avoid the increase in compressibility that would occur if the gases were left in the well near the discharge device. This is discussed below with reference to FIGS. 7 and 8.
[0062] [0062]FIG. 6 b shows a similar arrangement of injection wells 251 a , 251 b . . . 251 n and a producing well 253 . However, if the sources in the injection well are excited at different times by the surface control unit, then the acoustic waves 255 a ′, . . . 255 n ′ appear as shown and the corresponding wavefronts 257 a ′, . . . 257 n ′ arrive at the producing well at different times. In the example shown in FIG. 6 b , the acoustic wave 257 c ′ from well 251 c is the first to arrive.
[0063] In both FIG. 6 a and 6 b , the injection wells have been shown more or less linearly arranged on one side of the producing well. This is for illustrative purposes only and in actual practice, the injection wells may be arranged in any manner with respect to the producing well. Those versed in the art would recognize that with the arrangement of either 6 a or 6 b , the frequencies of the acoustic pulses may be controlled to a limited extent by controlling the pulse discharge in the sources using the inductance controls of the surface control unit. As noted in the background to the invention, these acoustic waves will have a limited range of frequencies. However, when combined with the large range of frequencies possible with the EM waves, the production of hydrocarbons may be significantly improved over prior art methods.
[0064] Turning now to FIG. 7, a tool of the present invention is shown deployed in a cased borehole within a formation 301 . The casing 305 and the cement 303 have perforations 307 therein. An upper packer assembly 309 and a lower packer assembly 311 serve to isolate the source and limit the depth interval of the well over which energy pulses are injected into the formation. In addition to the power supply 313 , provision is also made for water inflow 315 and water outflow 317 . The outflow carries with it any gases generated by the excitation of the source 319 . With the provision of the water supply, the borehole between the packers 309 , 311 is filled with water or other suitable fluid and is in good acoustic coupling with the formation. This increases the efficiency of generation of acoustic pulses into the formation.
[0065] An alternate embodiment of the invention that does not use packer assemblies is schematically depicted in FIG. 8 wherein a tool of the present invention is shown deployed in a cased borehole within a formation 351 . The casing 355 and the cement 353 have perforations (not shown). As in the embodiment of FIG. 7, in addition to the power supply 363 , provision is also made for water inflow 365 and water outflow 367 . The outflow carries with it any gases generated by the excitation of the source 369 . The tool is provided with a flexible sleeve 373 that is clamped to the body of the tool by clamps 371 and 375 . The sleeve isolates the fluid filled wellbore 357 from the water and the explosive source within the sleeve while maintaining acoustic coupling with the formation.
[0066] Turning now to FIG. 9, an embodiment of the invention allowing for directional control of the outgoing energy is illustrated. The tool 421 includes a bearing 403 that allows for rotation of the lower portion 405 relative to the upper portion 401 . This rotation is accomplished by a motor (not shown) that is controlled from the surface control unit. By this mechanism, the energy may be directed towards any azimuth desired. In addition, the tool includes a controller motor that rotates a threaded rotating post 409 . Rotation of the post 409 pivots a pulse director 412 in a vertical plane, and a substantially cone-shaped opening in the pulse director directs the outgoing energy in the vertical direction.
[0067] A common problem with prior art spark discharge devices is damage to the electrodes from repeated firing. One embodiment of the present invention that addresses this problem is depicted in FIG. 10. Shown are the electrodes 451 and 453 between which an electrical discharge is produced by the discharge of the capacitors discussed above with reference to FIG. 2. The electrode 451 connected to the power supply (not shown) is referred to as the “live” electrode. In such spark discharge devices, the greatest amount of damage occurs to the live electrode upon initiation of the spark discharge. In the device shown in FIG. 10, the live electrode is provided with a hollow cavity 454 through which a pencil electrode 457 passes. The pencil electrode 457 is designed to be expendable and initiation of the spark discharge occurs from the pencil electrode while the bulk of the electrical discharge occurs from the live electrode 451 after the spark discharge is initiated. This greatly reduces damage to the live electrode 451 with most of the damage being limited to the end 459 of the pencil electrode from which the spark discharge is initiated. The device is provided with a motor drive 455 that feeds the pencil electrode 457 through the live electrode upon receipt of a signal from the control unit received through the power and control leads 455 . In one embodiment of the invention, this signal is provided after a predetermined number of discharges. Alternatively, a sensor (not shown) in the downhole device measures wear on the pencil electrode and sends a signal to the control unit.
[0068] Another embodiment of the invention illustrated schematically in FIG. 11 uses a filament for the initiation of the spark discharge. The power leads (not shown) are connected to the live electrode 501 as before, and the return electrode 503 is positioned in the same way as before. The filament 511 is wound on a spool 509 and is carried between rollers 513 into a hole 504 within the live electrode. The spark is initiated at the tip 515 of the filament 511 . The filament 511 gets consumed by successive spark discharges and additional lengths are unwound from the spool 509 as needed using the power and control leads 505 .
[0069] [0069]FIG. 12 shows another embodiment of the invention wherein a gas 561 is conveyed through tubes 563 and 565 to the hollow lower electrode 553 via a threaded pressure fitting 569 . The lower electrode is coupled by means of a thread to the bottom plate 567 . The flowing gas gets ionized by the potential difference between the lower electrode 553 and the upper electrode 551 . The initiation of the spark takes place in this ionized gas, thereby reducing damage to the electrodes 551 and 553 .
[0070] There are a number of different methods in which the various embodiments of the device discussed above may be used. Central to all of them is the initiation of an electromagnetic wave into the formation. The EM wave by itself produces little significant hydrocarbon flow on a macroscopic scale; however, it does serve the function of exciting the hydrocarbons within the formation at a number of different scales as discussed above with reference to FIG. 5. This EM wave may be produced by an electromagnetic device, such as is shown in FIG. 4, or may be produced as part of an EH wave by a device such as described in the Wesley patent or described above with reference to FIGS. 10, 11 or 12 . This EM wave is initiated at substantially the same time as the arrival of the acoustic component of an earlier EH wave at the zone of interest from which hydrocarbon recovery is desired. Any suitable combination of EH and EM sources fired at appropriate times may be used for the purpose as long as an EM and an acoustic pulse arrive at the region of interest at substantially the same time.
[0071] For example, a single EH source as in FIG. 1, may be fired in a repetitive manner so that acoustic pulses propagate into the layer 11 : the EM component of later firings of the EH source will then produce the necessary conditions for stimulation of hydrocarbon flow at increasing distances from the wellbore 1 . Also by way of example, a vertical array of sources such as is shown in FIG. 5 may be used to propagate EM and acoustic pulses into the formation to stimulate hydrocarbon flow from different formations and from different types of pore spaces (fractures, intragranular, etc.). EH and/or EM sources may be fired from a plurality of wellbores as shown in FIG. 6 a , 6 b to stimulate hydrocarbon flow in the vicinity of a single production well. The sources may be oriented in any predetermined direction in azimuth and elevation using a device as shown in FIG. 9. In any of the arrangements, additional materials such as steam, water, a surfactant, a diluent or CO 2 may be injected into the subsurface. The injected material serves to increased the mobility of the hydrocarbon, and/or increase the flow of hydrocarbon.
[0072] The primary purpose of using electrohydraulic stimulation as described above is the recovery of hydrocarbons from the subsurface formations. However, as noted above in the Background of the Invention, the fluids recovered from a producing borehole may include a mixture of hydrocarbons and water and additional material such as, solids, CO 2 , H 2 S, SO 2 , inert gases
[0073] H. Vernon Smith in Chapter 12 of the Petroleum Engineering Handbook (Society of Petroleum Engineers), and the contents of which are fully incorporated herein by reference, reviews devices known as Oil and Gas Separators, that are normally used near the wellhead, manifold or tank battery to separate fluids produced from oil and gas wells into oil and gas or liquid and gas. In one embodiment of the present invention, any of the devices discussed in Smith may be used to separate fluids produced by the electrohydraulic stimulation discussed above. Favret (U.S. Pat. No. 3,893,918), the contents of which are fully incorporated herein by reference, teaches a fractionation column for separation of oil from a fluid mixture containing oil. Kjos (U.S. Pat. No. 5,860,476), the contents of which are incorporated herein by reference, teaches an arrangement in which a first cyclone separator is used to separate gas and liquid, a second cyclone separation is used to separate condensate/oil from water, and a membrane separation us used to separate gases including H 2 S, CO 2 , and SO 2 . U.S. Pat. No. 4,805,697 to Fouillout et al, the contents of which are fully incorporated herein by reference, teaches a method in which recovered fluids from the wellbore are separated into an aqueous and a light phase consisting primarily of hydrocarbons and the aqueous phase is reinjected into the producing formation.
[0074] U.S. Pat. No. 6,085,549 to Daus et al., the contents of which are fully incorporated herein by reference, teaches a membrane process for separating carbon dioxide from a gas stream. U.S. Pat. No. 4,589,896 to Chen et al, the contents of which are fully incorporated herein by reference, discloses the use of a membrane process for separation of CO 2 and H 2 S from a sour gas stream. One embodiment of the present invention uses a membrane process such as that taught by Daus and Chen et al to separate CO 2 , H 2 S, He, Ar, N 2 , hydrocarbon vapors and/or H 2 O from a gaseous component of the recovered fluids from the borehole: Perry's Chemical Engineers' Handbook, 7 th Ed., by Robert H. Perry and Don W. Green, 1997, Chapter 22, Membrane Separation Processes, page 22-61, Gas-Separation Processes the contents of which are incorporated herein by reference, teaches further methods for accomplishing such separation.
[0075] U.S. Pat. No. 5,983,663 to Sterner , the contents of which are fully incorporated herein by reference, discloses a fractionation process for separation of of CO 2 and H 2 S from a gas stream. One embodiment of the invention uses a fractionation process to separate CO 2 and H 2 S from the recovered formation fluids.
[0076] Another embodiment of the invention uses a solvent method for removing H 2 S from the recovered formation fluids using a method such as that taught by Minkkinen et al in U.S. Pat. No. 5,735,936, the contents of which are incorporated herein by reference.
[0077] Cryogenic separation may also be used to separate carbon dioxide and other acid gases from the recovered formation fluids. Examples of such methods are disclosed in Swallow (U.S. Pat. No. 4,441,900) and in Valencia et al (U.S. Pat. No. 4,923,493) the contents of which are fully incorporated herein by reference. Those versed in the art would recognize that removal of carbon dioxide from the recovered formation fluids is particularly important if, as discussed above with reference to FIG. 6 a , CO 2 injection is used in conjunction with electrohydraulic stimulation.
[0078] Another embodiment of the invention uses a process of cryogenic separation such as that taught by Wissoliki (U.S. Pat. No. 6,131,407), the contents of which are fully incorporated here by reference, for recovering argon, oxygen and nitrogen from a natural gas stream. Optionally, Helium may be recovered from a natural gas stream using a cryogenic separation such as that taught by Blackwell et al (U.S. Pat. No. 3,599,438), the contents of which are incorporated herein by reference. In another embodiment of the invention, a combination of cryogenic separation and solvent extraction, such as that disclosed in Mehra (U.S. Pat. No. 5,224,350) may be used for recovery of Helium.
[0079] As discussed above, a heavy liquid portion of the recovered formation fluids may include vanadium, nickel, sulphur and asphaltenes. In an alternate embodiment of the present invention, these may be recovered by using, for example, the method taught by UedaI et al (U.S. Pat. No. 3,936,371), the contents of which are incorporated herein by reference. The process disclosed in Ueda includes bringing the liquid hydrocarbon in contact with a red mud containing alumina, silica and ferric oxide at elevated temperatures in the presence of hydrogen. Another method for recovery of heavy metals disclosed by Cha et al (U.S. Pat. No. 5,041,209) includes mixing the heavy crude oil with tar sand, heating the mixture to about 800° F. and separating the tar send from the light oils formed during the heating. The heavy metals are then removed from the tar sand by pyrolysis.
[0080] While the foregoing disclosure is directed to the preferred embodiments of the invention, various modifications will be apparent to those skilled in the art. It is intended that all variations within the scope and spirit of the appended claims be embraced by the foregoing disclosure. | Pulsed power sources are installed in one or more wells in the reservoir interval. The pulse sources include (1) an electrohydraulic generator that produces an intense and short lived electromagnetic pulse that travels at the speed of light through the reservoir, and an acoustic pulse from the plasma vaporization of water placed around the source that propagates through the reservoir at the speed of sound in the reservoir and (2) an electromagnetic generator that produces only an intense and short lived electromagnetic pulse that travels at the speed of light through the reservoir. The combination of electrohydraulic and electromagnetic generators in the reservoir causes both the acoustic vibration and electromagnetically-induced high-frequency vibrations occur over an area of the reservoir where stimulation is desired. Single generators and various configurations of multiple electrohydraulic and electromagnetic generators stimulate a volume of reservoir and mobilize crude oil so that it begins moving toward a producing well. The method can be performed in a producing well or wells, an injector well or wells, or special wells drilled for the placement of the pulsed power EOR devices. The method can be applied with other EOR methods such as water flooding, CO2 flooding, surfactant flooding, diluent flooding in heavy oil reservoirs. The recovered formation fluids may be separated into various constituents. | big_patent |
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application is a continuation-in-part of co-pending U.S. patent application Ser. No. 12/684,479, entitled “Wave Anchor Soil Reinforcing Connector and Method,” which was filed on Jan. 8, 2010, the contents of which are incorporated herein by reference in their entirety.
BACKGROUND OF THE DISCLOSURE
Retaining wall structures that use horizontally positioned soil inclusions to reinforce an earth mass in combination with a facing element are referred to as Mechanically Stabilized Earth (MSE) structures. MSE structures can be used for various applications including retaining walls, bridge abutments, dams, seawalls, and dikes. Basic MSE technology involves a repetitive process by which layers of backfill and several horizontally placed soil reinforcing elements are sequentially positioned one atop the other until a desired height of the earthen structure is achieved.
Illustrated in FIG. 1 is a typical soil reinforcing element 100 that can be used in the construction of an MSE structure. The soil reinforcing element 100 generally includes a welded wire grid having a pair of longitudinal wires 102 that are disposed substantially parallel to each other. The longitudinal wires 102 are joined to a plurality of transverse wires 104 in a generally perpendicular fashion by welds or other attachment means at their intersections, thus forming the welded wire grid. In some applications, there may be more that two longitudinal wires 102 . The longitudinal wires 102 may have lead ends 106 that generally converge toward one another, as illustrated, and terminate at a wall end 108 . In other applications, however, the lead ends 106 do not converge, but instead terminate substantially parallel to one another. Backfill material and a plurality of soil reinforcing elements 100 are then combined and compacted sequentially to form a solid earthen structure taking the form of a standing earthen wall.
The wall end 108 of each soil reinforcing element 100 may include several different connective means adapted to connect the soil reinforcing element 100 to a substantially vertical facing 110 , such as a wire facing, or concrete or steel facings constructed a short distance from the standing earthen wall. Once appropriately secured to the vertical facing 110 and compacted within the backfill, the soil reinforcing element 100 provides tensile strength to the vertical facing 110 that significantly reduces any outward movement and shifting thereof.
The longitudinal wires 102 of the soil reinforcing element 100 may extend several feet into the backfill before terminating at corresponding reinforcing ends 112 . Where added amounts of tensile resistance are required, longer soil reinforcing elements 100 are required, thereby disposing the reinforcing ends 112 even deeper into the backfill. Single soil reinforcing elements 100 , however, often cannot be manufactured to the lengths required to adequately reinforce the vertical facing 110 , nor could such soil reinforcing elements 100 of extended lengths be safely or feasibly transported to job sites.
What is needed, therefore, is a system and method of splicing a soil reinforcing element to extend its length.
SUMMARY OF THE DISCLOSURE
Embodiments of the disclosure may provide a splice for a soil reinforcing element. The splice may include a first wave plate defining one or more first transverse protrusions configured to receive and seat a corresponding number of transverse wires of the soil reinforcing element, and a second wave plate defining one or more second transverse protrusions configured to receive and seat a corresponding number of transverse wires of a grid-strip. The splice may further include a first perforation defined in the first wave plate and a second perforation defined in the second wave plate, and a connective device extensible through the first perforation and the second perforation to couple the first wave plate to the second wave plate, wherein a portion of longitudinal wires of the soil reinforcing element and a portion of longitudinal wires of the grid strip are interposed between the first and second wave plates and are thereby prevented from removal.
Other embodiments of the disclosure may provide a composite soil reinforcing element. The composite soil reinforcing element may include a soil reinforcing element having a first plurality of transverse wires coupled to at least two longitudinal wires, the soil reinforcing element having a wall end and a reinforcing end, a grid-strip having a second plurality of transverse wires coupled to at least two longitudinal wires, the grid-strip having a splicing end, and a splice configured to couple the reinforcing end of the soil reinforcing element to the splicing end of the grid-strip. The splice may include a first wave plate defining one or more first transverse protrusions configured to receive and seat a corresponding number of the first plurality of transverse wires of the soil reinforcing element, and a second wave plate defining one or more second transverse protrusions configured to receive and seat a corresponding number of the second plurality of transverse wires of the grid-strip. The splice for the composite soil reinforcing element may further include a first perforation defined on the first wave plate and a second perforation defined on the second wave plate, and a first connective device extensible through the first perforation and the second perforation to couple the first wave plate to the second wave plate and clamp down on the at least two longitudinal wires of the soil reinforcing element and the at least two longitudinal wires of the grid-strip.
BRIEF DESCRIPTION OF THE DRAWINGS
The present disclosure is best understood from the following detailed description when read with the accompanying Figures. It is emphasized that, in accordance with the standard practice in the industry, various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or reduced for clarity of discussion.
FIG. 1 is a plan view of a prior art soil reinforcing element.
FIG. 2A is an isometric view of an exemplary splice, according to one or more aspects of the present disclosure.
FIG. 2B is an exploded view of the exemplary splice shown in FIG. 2A .
DETAILED DESCRIPTION
It is to be understood that the following disclosure describes several exemplary embodiments for implementing different features, structures, or functions of the invention. Exemplary embodiments of components, arrangements, and configurations are described below to simplify the present disclosure; however, these exemplary embodiments are provided merely as examples and are not intended to limit the scope of the invention. Additionally, the present disclosure may repeat reference numerals and/or letters in the various exemplary embodiments and across the Figures provided herein. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various exemplary embodiments and/or configurations discussed in the various Figures. Moreover, the formation of a first feature over or on a second feature in the description that follows may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features may be formed interposing the first and second features, such that the first and second features may not be in direct contact. Finally, the exemplary embodiments presented below may be combined in any combination of ways, i.e., any element from one exemplary embodiment may be used in any other exemplary embodiment, without departing from the scope of the disclosure.
Additionally, certain terms are used throughout the following description and claims to refer to particular components. As one skilled in the art will appreciate, various entities may refer to the same component by different names, and as such, the naming convention for the elements described herein is not intended to limit the scope of the invention, unless otherwise specifically defined herein. Further, the naming convention used herein is not intended to distinguish between components that differ in name but not function. Additionally, in the following discussion and in the claims, the terms “including” and “comprising” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to.” All numerical values in this disclosure may be exact or approximate values unless otherwise specifically stated. Accordingly, various embodiments of the disclosure may deviate from the numbers, values, and ranges disclosed herein without departing from the intended scope. Furthermore, as it is used in the claims or specification, the term “or” is intended to encompass both exclusive and inclusive cases, i.e., “A or B” is intended to be synonymous with “at least one of A and B,” unless otherwise expressly specified herein.
Referring to FIGS. 2A and 2B , depicted is an exemplary joint or splice 200 , according to one or more embodiments of the disclosure. The splice 200 may be employed to lengthen the extent of a soil reinforcing element 100 , such as the soil reinforcing element 100 generally described above with reference to FIG. 1 . Extending the length of the soil reinforcing element 100 may prove advantageous where the soil reinforcing element 100 is not long enough to adequately reinforce a vertical facing 110 ( FIG. 1 ) into adjacent backfill (not shown).
As will be appreciated by those skilled in the art, several designs of soil reinforcing elements 100 having numerous connective devices for attaching the soil reinforcing element 100 to a vertical facing 110 can be used without departing from the scope of the disclosure. For example, the soil reinforcing elements and their various connective devices described in co-owned U.S. Pat. Nos. 6,517,293 and 7,722,296 may be used, the contents of these patents are hereby incorporated by reference to the extent not inconsistent with the present disclosure. Other examples of soil reinforcing elements and their exemplary connective devices that may be appropriately used with the splice 200 disclosed herein include co-pending U.S. patent application Ser. Nos. 12/479,448, 12/756,898, 12/818,011, 12/837,347, and 12/861,632 filed on Jun. 5, 2009, Apr. 8, 2010, Jun. 17, 2010, Jul. 15, 2010, and Aug. 23, 2010, respectively, the contents of each application are also hereby incorporated by reference to the extent not inconsistent with the present disclosure.
To effectively extend the length of a soil reinforcing element 100 into adjacent backfill (not shown), the splice 200 may couple one or more grid-strips 202 to the soil reinforcing element 100 . The grid-strip 202 generally extends the length of the soil reinforcing element 100 to the length required for the particular MSE application. Similar to the soil reinforcing element 100 , the grid-strip 202 may include at least two longitudinal wires 204 welded or otherwise attached to a plurality of transverse wires 206 . Although only two longitudinal wires 204 are illustrated, it will be appreciated that the grid-strip 202 may include any number of longitudinal wires 204 without departing from the scope of the disclosure. Once coupled together, the combination of the soil reinforcing element 100 , splice 200 , and grid-strip 202 may be characterized or otherwise typified as a single composite soil reinforcing element, for purposes of reinforcing a vertical facing 110 ( FIG. 1 ).
In one or more embodiments, the transverse wires 206 may be equally-spaced or substantially equally-spaced along the length of the longitudinal wires 204 of the grid-strip 202 . The spacing between each transverse wire 104 of the soil reinforcing element 100 may be the same or substantially the same as the spacing between each transverse wire 206 of the grid-strip 202 . In other embodiments, however, the spacing of the transverse wires 104 , 206 may only need to be equally-spaced at or near the reinforcing end 112 of the soil reinforcing element 100 or a splicing end 214 of the grid-strip. In yet other embodiments, the spacing of the transverse wires 104 , 206 is irregular along the length of the longitudinal wires 102 , 204 , respectively.
The splice 200 may include one or more wave plates, such as a first plate 208 a and a second plate 208 b . In at least one embodiment, the first and second wave plates 208 a,b are mirror images of one another. Each wave plate 208 a,b may include one or more transverse protrusions 210 longitudinally-offset from each other. Each wave plate 208 a,b may further define one or more plate perforations, such as plate perforations 212 a , 212 b , and 212 c , as shown in FIG. 2B . Each transverse protrusion 210 may be configured to receive and/or seat either a transverse wire 104 from the soil reinforcing element 100 or a transverse wire 206 from the grid-strip 202 . Accordingly, in embodiments having two or more transverse protrusions 210 , each protrusion 210 may be spaced a predetermined distance from an adjacent protrusion 210 so as to correspond to the equally-spaced transverse wires 104 , 206 of either the soil reinforcing element 100 or the grid-strip 202 .
In one or more embodiments, one or more transverse wires 104 proximal the reinforcing end 112 of the soil reinforcing element 100 may be coupled to or otherwise seated within the first wave plate 208 a . Likewise, one or more transverse wires 206 proximal a splicing end 214 of the grid-strip 202 may be coupled to or otherwise seated within the second wave plate 208 b . As illustrated, the transverse wires 104 of the soil reinforcing element 100 may be disposed above their respective longitudinal wires 102 , and the transverse wires 206 of the grid-strip 202 may be disposed below their respective longitudinal wires 204 . In other embodiments, however, the relative disposition of the transverse wires 104 , 206 may be reversed without departing from the scope of the disclosure. Furthermore, the longitudinal wires 102 of the soil reinforcing element 100 may be laterally-offset from the longitudinal wires 204 of the grid-strip 202 .
As the plates 208 a,b are brought together, and the corresponding perforations 212 a,b,c of each plate 208 a,b are axially aligned, the transverse wire(s) 104 of the soil reinforcing element 100 may be seated or otherwise received into the transverse protrusions 210 of the first wave plate 208 a , and the transverse wire(s) 206 of the grid-strip 202 may be seated or otherwise received into the transverse protrusions 210 of the opposing second wave plate 208 b . With the corresponding perforations 212 a,b,c generally aligned, the transverse wires 104 of the soil reinforcing element 100 disposed within corresponding transverse protrusions 210 of the first wave plate 208 a may be vertically-offset from the transverse wires 206 of the grid-strip 202 disposed within corresponding transverse protrusions 210 of the second wave plate 208 b.
The splice 200 may be secured by coupling the first wave plate 208 a to the second wave plate 208 b . This can be done in several ways. In at least one embodiment, a connective device 216 , such as a threaded bolt or similar mechanism, may be extended through one or more of the perforations 212 a,b,c defined on each plate 208 . While only two connective devices 216 are shown in FIGS. 2A and 2B , it will be appreciated that any number connective devices 216 may be employed as corresponding to an equal number of perforations 212 defined in the plates 208 a,b . In one embodiment, a single connective device 216 may be employed to couple the first wave plate 208 a to the second wave plate 208 b.
Each connective device 216 may be secured against removal from the splice 200 by threading a nut 218 or similar device onto its end. Furthermore, one or more washers 220 may also be used to provide a biasing engagement with each plate 208 a,b . As can be appreciated, the nut 218 and connective device 216 configuration may be substituted with any attachment methods known in the art. For instance, rebar or any other rigid rod may be used and bent over on each end to prevent its removal from the perforations 212 a,b,c , and thereby provide an adequate coupling mechanism.
Once the splice 200 is made secure, the transverse wires 104 , 206 may be prevented from longitudinally escaping the splice 200 since they are seated in respective transverse protrusions 210 . Tightening the nut(s) 218 onto the bolt(s) 216 , or similar connection device, may clamp down on the longitudinal wires 102 , 204 of the soil reinforcing element 100 and grid-strip 202 , respectively, thereby preventing the soil reinforcing element 100 and/or grid-strip 202 from translating laterally and thereby escaping the splice 200 .
As will be appreciated, any number of splices 200 and grid-strips 202 may be used to extend the length of a single soil reinforcing element 100 and create a composite soil reinforcing element that achieves a desired reinforcing distance from the vertical facing 110 ( FIG. 1 ). For instance, if splicing a first grid-strip 202 to the reinforcing end 112 of the soil reinforcing element 100 does not extend a sufficient distance into the backfill (not shown), a second grid-strip 202 may be spliced to the end of the first grid-strip 202 , and so on until the desired distance is achieved. Accordingly, multiple splices 200 and multiple grid-strips 202 may be used to extend the length of a single soil reinforcing element 100 .
The foregoing has outlined features of several embodiments so that those skilled in the art may better understand the present disclosure. Those skilled in the art should appreciate that they may readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments introduced herein. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions and alterations herein without departing from the spirit and scope of the present disclosure. | A system and method of constructing a mechanically stabilized earth (MSE) structure. A wire facing is composed of horizontal and vertical elements. A soil reinforcing element has a plurality of transverse wires coupled to at least two longitudinal wires having lead ends that upwardly-extend. A bearing plate includes one or more longitudinal protrusions configured to receive and seat the upwardly extending lead ends and couple the soil reinforcing element to the wire facing, and in particular to the vertical element. Multiple systems can be characterized as lifts and erected one atop the other to a desired MSE structure height. | big_patent |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of and claims the benefit of U.S. patent application Ser. No. 10/396,619, filed Mar. 25, 2003, entitled “PLOW BLADE WITH WATER PASSAGEWAY.”
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable
BACKGROUND OF THE INVENTION
[0003] Many types of services are delivered to homes through conduits installed in relatively shallow underground trenches. These include telephone, television, natural gas, electricity, and drainage. These utilities are often installed with a plow. FIG. 1 illustrates an example installation of a utility 20 with a prior art plowing process. A plow 30 is attached to a prime mover, typically a tractor 10 . The tractor 10 propels the plow through the ground. The plow 10 is relatively narrow and will split the ground open with a sharpened steel blade. The utility line 20 is introduced into the ground through a chute 40 that is attached to and directly behind the blade. The chute 40 holds the ground open as the utility line 20 is being fed into the desired vertical position and places the utility line 20 into a horizontal position at the desired depth under ground.
[0004] An alternate configuration is illustrated in FIG. 2 where the utility line 20 is laid out on the ground behind its intended position and then the plow 30 is connected to one end. The plow is then pulled through the ground in order to pull the utility line 20 into the correct position. In this configuration there is no chute.
[0005] Depending on the desired depth, size of utility line, and the ground (soil) conditions (clay, sand, loam, etc.). This process may be slow and require a large amount of power from the tractor 10 to pull the blade/chute through the ground. To reduce this loading various efforts have been made to inject liquid to the plow and to the utility being installed to wet the ground.
[0006] In some past designs the liquid was water, ejected in the direction of travel of the plow blade, and at the edge of the plow blade, utilizing the water to assist in the cutting action required to slice the ground.
[0007] In other designs, useful for applications as illustrated in FIG. 2 , the liquid has been water directed to the area around the utility line being pulled through the ground to lubricate and reduce the frictional drag.
[0008] In still other designs water has been directed through long holes 36 drilled into the blade 34 of the plow 30 . Additional cross-drilled holes threaded to accept cooperating nozzles 38 are drilled near front edge 32 , as illustrated in FIGS. 3 and 4 . Water was then pumped into inlet fitting 37 to route water to the sides of the plow. This design has proven successful as the lubrication provided by the water significantly reduces the power necessary to pull the plow. However this requires complicated manufacturing processes, with the result that a wear item, the blade, becomes a relatively expensive component. There exists a need for a blade to provide this water distribution in a manner, that is less expensive to initially manufacture and to maintain.
BRIEF SUMMARY OF THE INVENTION
[0009] The present invention relates to a novel design for a plow blade which provides a fluid passage and points of fluid ejection which is produced with basic manufacturing processes allowing efficient production.
[0010] Another aspect of the present invention is a blade construction including a multiple component assembly. This provides the ability to rebuild a blade, replacing a portion of the blade that may be worn.
[0011] In another aspect of the present invention a process of ejecting a specific fluid at specific points along a plow blade the desirable characteristics are maximized, while the volume of ejected fluid is minimized. This method is adaptable in static plowing and vibratory plowing utilities. Lubricating the sides of the blade/chute that come into contact with the ground with fluid has been found to greatly reduce the amount of drag (friction).
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a side view of a prior art tractor propelling a plow through the ground and installing a utility line that is being ejected through a chute attached to the plow;
[0013] FIG. 2 is a side view of a prior art tractor propelling a plow through the ground and installing a utility that is being pulled through the ground and attached to the plow;
[0014] FIG. 3 is side view of a prior art plow;
[0015] FIG. 4 is cross section of the prior art plow taken along line 4 - 4 as illustrated in FIG. 3 ;
[0016] FIG. 5 is a side view of one embodiment of a plow constructed in a manner of the present invention;
[0017] FIG. 6 is an isometric view of a portion of another embodiment of the plow of the present invention;
[0018] FIG. 7 is a cross-section taken along plane 7 - 7 as illustrated in FIG. 6 ;
[0019] FIG. 8 is an isometric view of a front edge section;
[0020] FIG. 9 is an isometric view of a portion of still another embodiment of the plow of the present invention;
[0021] FIG. 10 is a cross-section taken along plane 10 - 10 as illustrated in FIG. 9 ;
[0022] FIG. 11 is a side view of another preferred embodiment of a plow constructed in a manner of the present invention;
[0023] FIG. 11A is an enlarged view of the part marked 11 A in FIG. 11 ;
[0024] FIG. 12 is a cross-section taken along plane 12 - 12 as illustrated in FIG. 11 ;
[0025] FIG. 13 is cross-section taken along plane 13 - 13 as illustrated in FIG. 11 ;
[0026] FIG. 14 is a partial cross-section taken along plane 13 - 13 as illustrated in FIG. 11 : and
[0027] FIG. 15 is a view like FIG. 7 but showing an alternate embodiment with the void or channel formed in the blade instead of in the back of the front edge section.
DETAILED DESCRIPTION OF THE INVENTION
[0028] Referring now to the drawings, like reference numerals designate identical or corresponding parts throughout the several views. The included drawings reflect the current preferred and alternate embodiments. There are many additional embodiments that may utilize the present invention. The drawings are not meant to include all such possible embodiments.
[0029] FIG. 5 illustrates a plow 100 constructed according to the principles of the present invention. Plow 100 consists of blade 110 , leading edge sections 120 , point 130 and a fluid tube 140 . Chute 40 is attached to the rear edge 114 of blade 110 , and is constructed to receive and guide utility line 20 from above the ground to the desired depth where it is oriented generally parallel to the ground surface. In other embodiments, the chute may be replaced by a puller adapted to hold a utility line that is being pulled through the ground, similar to the arrangement shown in FIG. 2 .
[0030] The blade 110 further includes a front edge 112 , a top end 116 and a bottom end 118 . The top end 116 includes apertures 117 which will serve as attachment points, to adapt to a power unit. Many different types of power units can be used in conjunction with the preset invention.
[0031] The bottom end 118 is adapted to support a variety of points 130 . The type of point to be installed may be dependent upon the soil conditions of a particular job.
[0032] A component of the present invention is the manner in which the components are assembled to form flow paths for fluid to exit the blade at controlled locations and with a controlled flow rate. The flow paths of this first embodiment illustrated in FIG. 1 are defined when the front edge 120 is attached to the blade 110 . FIG. 8 illustrates a void 124 in surface 122 of leading edge section 120 . Fluid tube 140 is adapted to travel in void 124 to transfer pressurized fluid from the top of plow 100 into the void 124 , and may be sealed with weld 152 illustrated in FIG. 6 . Other forms of sealing the connection between the tube 140 and the front edge sections 120 are possible, but are not illustrated herein as they are not a critical element of the present invention. Tube 140 has a top end 144 and a bottom end 146 and may extend into void 124 for any desired distance, as will be explained later.
[0033] As illustrated in FIGS. 6 and 7 the leading edge sections are attached to blade 110 with stitch welds 150 . Flow paths are defined by providing a small gap 154 between the front surface 112 of the blade and the rear surface 122 . The spaces between the stitch welds 150 results a flow path for the pressurized fluid, allowing fluid to pass from the void 124 , through the gap 154 between surfaces 122 and 112 , and out between the stitch welds 150 . In this manner, the location and length of the stitch welds 150 defines the location at which the fluid will exit the blade 110 . The gap 154 ( FIG. 7 ) between the surfaces 112 and 122 combined with the total amount of weld gap will define the volume at which the fluid will be ejected from the blade 110 at a certain fluid pressure.
[0034] FIG. 15 shows an alternate arrangement of the FIG. 7 structure, having the void or groove 224 formed in the front of the blade instead of having the void or groove 124 formed in the back of the leading edge section as shown in FIG. 7 .
[0035] The fluid pressure at a certain point along the blade's length will vary. If the tube 140 terminates at the top of blade 110 , the fluid pressure will be highest at that point and will decrease at points closer to the bottom. This is not ideal as there tends to be more resistance from the soils near the bottom of the blade, which requires the highest fluid pressure near that area. This is due to the types of soils typically encountered at lower depths. The surface soils typically include some percentage of organic matter, and higher percentage of air pockets: it is typically less dense. The soils encountered at points deeper can include the more difficult soils including clay. Thus there is an area, illustrated in FIG. 5 , as a critical high friction area. This is the area in which the fluid is most critical. In order to assure that the fluid is ejected most aggressively in this area tube 140 can be extended so that it terminates at a position towards the bottom of this critical high friction area, the tube end 146 is located near the bottom end 118 of the blade 110 . The fluid pressure in void 124 will be highest at the point the tube terminates. In this manner the volume of fluid at this point can be maximized.
[0036] In addition to varying the length of tube 140 , the number of leading edge sections 120 that are welded onto blade 110 can be varied to match the requirements of a specific job, including specific installation depths. The number of and location of the stitch welds can also be adjusted to tailor a plow 100 for a specific application. In this manner it is possible to provide a nearly infinite variety of configurations in an economic manner.
[0037] Another embodiment is illustrated in FIGS. 9 and 10 . In this configuration a manifold 160 is installed in between the blade 110 and the leading edge sections 120 . The manifold includes drilled holes 166 extending from a front side 164 to a rear side 162 , as illustrated in FIG. 10 . The drilled holes 166 intersect at the middle, and when the leading edges 120 are installed onto the front side 164 the drilled holes 166 will terminate at the void 124 in the leading edge 120 . In this manner a flow path is defined by the void 124 and the holes 166 which will allow fluid to be routed from tube 140 to nozzles 168 that are installed at the rear side 162 of the manifold 160 .
[0038] In this embodiment varying the nozzles 168 utilized in the assembly allows control of the flow rates and location of the fluid injection. The nozzles 168 can be replaced by plugs (not shown) if there are areas where fluid is not required, and the size of the nozzles 168 can be varied if the there are areas where extra flow is required. It provides a plow that can be modified using hand tools, without welding.
[0039] Still another preferred embodiment is illustrated in FIGS. 11 , 11 A, 12 and 13 . In this embodiment the fluid tube 140 has been located on the opposite side of blade 110 , the rear side 114 . As can be seen in FIG. 12 the fluid tube is located between the blade 110 and the chute 40 . In this configuration it is protected by plates 42 . The fluid tube includes an inlet fitting 142 at the top and travels to the bottom end 118 of blade 110 where it terminates at tube end 146 . The cross hatched portion shown in FIG. 11A represents a weld.
[0040] Tube end 146 is adapted to attach to a bottom end section 126 , as illustrated in FIG. 13 . Bottom end section 126 includes void 128 in the top side 127 as illustrated in FIG. 14 . Tube 140 includes a bend that allows it to enter into void. The tube 140 is then sealed by welding it to the bottom end section 126 and the blade 110 with weld 156 such that the fluid is forced into void 128 . The bottom end section 126 is also welded to the blade 110 at the locations where it contacts the blade 110 , thus sealing the void 128 .
[0041] Void 128 intersects void 124 at the bottom-front corner of blade 110 . At this point the fluid is transferred to void 124 and will flow along the front edge 112 of blade 110 . As described for the previous two embodiments, the fluid can then be allowed to travel to the edge of the blade and out to the soil either through a gap and spaces between stitch welds 150 , or through a manifold 160 between the front edge sections 120 and the blade 110 . FIGS. 11 and 12 illustrate the use of the stitch welds 150 and gaps 151 between stitch welds 150 . However, the manifold 160 would work equally well.
[0042] All the previously described embodiments provide a plow that can be tailored to provide fluid injection characteristics to match specific job requirements. The components are all manufactured with traditional manufacturing processes. The flow paths are defined by stacking together leading edge sections with flow voids, and welding or otherwise attaching them to a blade. This configuration provides appropriate function and provides an easily tailored configuration.
[0043] Obviously many modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described. | A plow blade having a fluid passageway and points of fluid ejection is produced with basic manufacturing processes allowing for efficient production. The blade construction has a multiple component assembly for providing the ability to rebuild a blade and replacing a portion of the blade that may be worn. In another aspect of the invention a process of ejecting a specific fluid at specific points along a plow blade the desirable characteristics are maximized, while the volume of ejected fluid is minimized. This method is adaptable in static plowing and vibratory plowing utilities since lubricating the sides of the blade/chute that come into contact with the ground with fluid has been found to greatly reduce the amount of drag (friction). | big_patent |
FIELD OF THE INVENTION
[0001] The present invention relates to a building system. More particularly the invention relates to stucco type cavity wall construction techniques and resultant consumables, subassemblies, assemblies, etc.
[0002] Exterior panels defined in situ in a plaster material in New Zealand have been restricted to a height no higher than about 2.4 meters high and 4 meters wide by building regulation. Larger cladding areas require movement control joints.
[0003] The present invention in one aspect is directed to a building system (eg. structures, methods, procedures, apparatus, etc) which would allow panels of greater than 2.4 meters in height to be created and/or greater than 4 meters width to be created without movement joints.
[0004] The present invention also or instead is directed to building envelopes being closed by a cavity wall plaster system which, with our without movement control joints (eg. vertical and/or horizontal control joints), can provide walls of considerable size and/or non-square or non-rectangular perimeter.
BACKGROUND OF THE INVENTION
[0005] For a typical (nominal) 21 mm panel thickness in compliance with NZS3604, we envisage at least square or rectangular panels being created in situ that can achieve, without a movement control joint, a height of at least 4.85 meters and can be as wide as much as, for example, up to 12 meters, all without mandatory movement control joints. Smaller panel widths of 6 meters, 8 meters or other are also within the compass of the present invention. Likewise heights.
[0006] By way of example, and without in any way being limiting, we expect for an in situ panel, of say 21 mm thickness so as to be NZ compliant, a single level panel size of, say, 2.4×6 metres and a double level panel size of say, 5.2×8 metres without any mandatory movement control joint.
[0007] In other countries (eg. USA) a thicker panel of say, about 40 mm may find favour. We expect our system to cater similarly for such panels.
[0008] Irrespective of the dimensions of any resultant panel, its peripheral shape, etc any method of in situ formation of a reinforced plaster panel that allows that greater dimensional reach of a panel is also within the scope of the present invention. However a preferred system of plaster matrix will be described with respect to NZ requirements but in no way restricted to NZ regulatory constraints.
[0009] It is an aim or object of the present invention to provide a building and/or a building system, related assemblies, sub assemblies, procedures, methods, panels, flashings, reinforcements, cavity walls of part stucco construction, etc which will at least provide the public with a useful choice.
[0010] It is a further or alternative aim or object of the present invention to provide compliance with the plaster code NZS4251 in the provision of a building and/or a building system, related assemblies, subassemblies, procedures, methods, panels, flashings, reinforcements, cavity walls of part stucco construction etc, all which will at least provide the public with the useful choice.
[0011] It is a further or alternative aim or object of the present invention to provide compliance with the building code NZS3604 in the provision of a building and/or a building system, related assemblies, subassemblies, procedures, methods, panels, flashings, reinforcements, cavity walls of part stucco construction etc, all which will at least provide the public with the useful choice.
[0012] It is a further or alternative aim or object of the present invention to provide compliance with the building code NZS3604 and plaster code NZS4251 in the provision of a building and/or a building system, related assemblies, subassemblies, procedures, methods, panels, flashings, reinforcements, cavity walls of part stucco construction etc, all which will at least provide the public with the useful choice.
[0013] It is a further or alternative aim to provide stucco walled structures having panel rigidity and integrity.
[0014] It is a further or alternative aim or object of the present invention, or at least some embodiments, of the present invention to provide methods to meet what is expected to be allowable under NZ regulation.
BRIEF DESCRIPTION OF THE INVENTION
[0015] In an aspect the invention is a building which has as a wall of its envelope, a wall of a size of at least 2.4 m high, at least 4 m wide and about 21 mm thick;
[0016] wherein the wall has
[0017] a frame or a substructure having studs at least some of which are spaced by a modular distance,
[0018] battens supported from and fixed to said frame or substructure, such battens fixed both on and between studs,
a first mesh (“inner mesh”) attached to such battens, a second (“outer”) mesh supported at least in part by a plaster matrix, and the plaster matrix applied as more than one layer, the plaster matrix penetrating the first mesh, interposing both meshes, attaching to the second mesh and covering the second mesh;
[0021] wherein the wall has at least one opening selected from a group consisting of door and window openings;
[0022] and wherein at least part of the periphery of each opening, within the matrix, has been further reinforced by one or more of
(a) one or more of at least one mesh and/or lattice-work at each corner, (b) one or more of at least one mesh and/or lattice-work at each vertical side, and/or (c) one or more mesh between adjacent openings.
[0026] Preferably the studs are of minimum cross-section of 45 mm×90 mm.
[0027] Preferably there are dwangs at nominal 900 mm spacings between the studs.
[0028] Preferably the batten attached mesh is of a metal.
[0029] Preferably the batten attached mesh overlies a backing sheet.
[0030] Preferably the battens are of nominal 35 mm×40 mm cross-section.
[0031] Preferably the second mesh is non-metallic
[0032] Preferably regional reinforcement is by or includes metallic mesh.
[0033] Preferably the metallic mesh regional reinforcement has been attached prior to being embedded.
[0034] Preferably regional reinforcement is by or includes a non-metallic sheet material or mesh able to be embedded and penetrated by the matrix material.
[0035] Preferably panel boundaries include at least partially embedded lattice-like periphery defining members.
[0036] In another aspect the invention is a building which has a wall that has
[0037] a frame or a substructure that includes studs substantially to a modularly spacing of about 600 mm where suitable,
[0038] battens supported from and fixed to said frame or substructure, said battens being fixed both to at least the modularly spaced studs and inbetween,
[0039] a first mesh attached to such battens,
[0040] a second mesh supported at least in part by a plaster matrix, and
[0041] one or more additional mesh as regional mesh reinforcement,
[0042] the plaster matrix applied as more than one layer, the plaster matrix penetrating the first mesh, embedding the second mesh, embedding the regional mesh or meshes.
[0043] Preferably the studs are of minimum cross-section of 45 mm×90 mm.
[0044] Preferably there are dwangs (preferably at nominal 900 mm spacings) between the studs.
[0045] Preferably the batten attached mesh is of a metal.
[0046] Preferably the batten attached mesh overlies a backing sheet.
[0047] Preferably the battens are of nominal 35 mm×40 mm cross-section.
[0048] Preferably the second mesh is non-metallic
[0049] Preferably regional reinforcement is by or includes metallic mesh.
[0050] Preferably the metallic mesh regional reinforcement has been attached prior to being embedded.
[0051] Preferably regional reinforcement is by or includes a non-metallic sheet material or mesh able to be embedded and penetrated by the matrix material.
[0052] Preferably panel boundaries include at least partially embedded lattice-like periphery defining members.
[0053] In still another aspect the invention is a stucco wall comprising or including
[0054] a stud including wall frame,
[0055] battens carried by the wall frame and in excess of the number of studs in the wall frame,
[0056] a mesh or the like perforate reinforcement sheet(s) carried by the battens,
[0057] a mesh or the like perforate reinforcement sheet(s) outwardly of and spaced from the batten carried sheet(s),
[0058] additional regional reinforcement mesh,
[0059] lattice and/or perforate reinforcement, and
[0060] a plaster or cementitious matrix, applied as at least a two layer application, that penetrates the batten carried sheet(s) and embeds or also embeds the other said reinforcement(s).
[0061] Preferably the studs are of minimum cross-section of 45 mm×90 mm.
[0062] Preferably there are dwangs (preferably at nominal 900 mm spacings) between the studs.
[0063] Preferably the batten attached mesh is of a metal.
[0064] Preferably the batten attached mesh overlies a backing sheet.
[0065] Preferably the battens are of nominal 35 mm×40 mm cross-section.
[0066] Preferably the second mesh is non-metallic
[0067] Preferably regional reinforcement is by or includes metallic mesh.
[0068] Preferably the metallic mesh regional reinforcement has been attached prior to being embedded.
[0069] Preferably regional reinforcement is by or includes a non-metallic sheet material or mesh able to be embedded and penetrated by the matrix material.
[0070] Preferably panel boundaries include at least partially embedded lattice-like periphery defining members.
[0071] In another aspect the invention is a building which has as a wall of its envelope, a wall of a size of at least 2.4 m high, at least 4 m wide and about 21 mm thick;
[0072] wherein the wall has
[0073] a frame or a substructure,
[0074] battens supported from and fixed to said frame or substructure,
[0075] a first mesh (“inner mesh”) attached to such battens,
[0076] a second (“outer”) mesh supported at least in part by a plaster matrix, and
[0077] the plaster matrix applied as more than one layer, the plaster matrix penetrating the first mesh, interposing both meshes, attaching to the second mesh and covering the second mesh;
[0078] wherein the wall has at least one opening selected from a group consisting of door and window openings;
[0079] and wherein the, or each, opening is positioned only as allowed and the, or each, opening is further reinforced in the plaster matrix at least substantially in accordance with the Rules as herein provided (preferably thereby to be NZS3604, or both NZS3604 and NZS4251, compliant, all as current June 2010).
[0080] Preferably the frame or substructure has studs that are of minimum cross-section of 45 mm×90 mm.
[0081] Preferably there are dwangs at nominal 900 mm spacings between the studs.
[0082] Preferably the batten attached mesh is of a metal.
[0083] Preferably the batten attached mesh overlies a backing sheet.
[0084] Preferably the battens are of nominal 35 mm×40 mm cross-section.
[0085] Preferably the second mesh is non-metallic
[0086] Preferably regional reinforcement is by or includes metallic mesh.
[0087] Preferably the metallic mesh regional reinforcement has been attached prior to being embedded.
[0088] Preferably regional reinforcement is by or includes a non-metallic sheet material or mesh able to be embedded and penetrated by the matrix material.
[0089] Preferably panel boundaries include at least partially embedded lattice-like periphery defining members.
[0090] In yet another aspect the invention is a building having at least one stucco wall, the stucco matrix having been layed up as plural settable layers, the wall being of at least 2.4 m high, at least 4 m wide and about 21 mm thick, the wall comprising or including
[0091] a frame or a substructure that includes studs of at least 45×90 mm cross-section, where appropriate, at about 600 mm centres,
[0092] battens of about 40 by 35 mm cross-section supported from the frame or substructure both on and in
[0093] between the studs,
[0094] reinforcement metal mesh attached to the battens and penetrated by a said layer of the stucco matrix,
[0095] reinforcement set out from the batten carried metal mesh and embedded in the stucco matrix,
[0096] regional extra embedded reinforcement, and
[0097] the stucco matrix
[0098] Preferably there are dwangs at nominal 900 mm spacings between the studs.
[0099] Preferably the batten attached mesh is of a metal.
[0100] Preferably the batten attached mesh overlies a backing sheet.
[0101] Preferably the second mesh is non-metallic
[0102] Preferably regional reinforcement is by or includes metallic mesh.
[0103] Preferably the metallic mesh regional reinforcement has been attached prior to being embedded.
[0104] Preferably regional reinforcement is by or includes a non-metallic sheet material or mesh able to be embedded and penetrated by the matrix material.
[0105] Preferably panel boundaries include at least partially embedded lattice-like periphery defining members.
[0106] In another aspect the invention consists in a building [or any kit, method or procedures which results in such a building] which has, or is to have, as part of its envelope and/or any wall,
a frame or a substructure, battens supported from and fixed to said frame or substructure, a first mesh (“inner mesh”) attached to such battens, a second mesh (“outer mesh”) supported at least in part by a plaster matrix, and the plaster matrix applied as more than one layer; wherein the plaster matrix penetrates the first mesh, interposes both meshes, attaches to the second mesh, and covers the second mesh;
[0113] wherein the panels (at least of said primary plaster matrix and the meshes has one or more of the following characteristics,
is about 21 mm thick is of a size of at least 2.4×4 m has no movement control joints has movement control joints mandated by the Rules hereafter has extra mesh reinforcement outwardly of the corners of openings has extra mesh reinforcement between openings has said extra mesh positioned within a base layer of the plaster matrix, the plaster matrix being of several applied layers has embedded unfixed extra mesh reinforcement mandated by the Rules hereafter has such extra reinforcement mandated by the Rules positioned within a layer of the plaster matrix, the plaster matrix being of several applied layers.
[0123] Preferably the first mesh is a metal mesh.
[0124] Preferably said first mesh “wraps” (as herein defined) the framing or substructure over the battens and to and/or substantially to any openings of the envelope.
[0125] Preferably prepared mesh sheet (preferably zinc coated) has been used as the inner mesh, paper side inwards.
[0126] Preferably the pre-papering provides, as if formwork, for first layer plaster application capture behind and to the inner mesh.
[0127] Preferably, or optionally, the inner mesh is of vertical and horizontal wire.
[0128] Optionally and preferably corners of openings have as additional reinforcement for and/or support for the plaster matrix (almost as if a patch), a zone a mesh with its wires running substantially at an angle with respect to the vertical and horizontal wires of the inner mesh “wrap”. These are outwards of each corner of any opening (e.g. doors or windows).
[0129] Preferably each corner is also further reinforced as additional reinforcement for, and/or support for, the plaster matrix, (almost as if a patch) a zone of a Rules mandated mesh between openings of close proximity (whether of same height or not). Preferably this is embedded in the base coat of the plaster system.
[0130] Preferably the first or inner mesh is a metal or wire mesh. It can be woven, forge knotted, welded or the like mesh or can be expanded perforate sheet material to define a “mesh”.
[0131] Preferably the outer or Rules mandated mesh is a non-metal mesh e.g. preferably fibreglass. Preferably that is a woven mesh.
[0132] Preferably external corners have a skeletal or lattice member embedded at least in part by the plaster matrix and embedded on both sides of the corner by the plaster matrix (eg. as if flanges).
[0133] Preferably the skeletal or lattice member is batten supported.
[0134] Preferably the external corner skeletal or lattice member is over the inner mesh.
[0135] Preferably the corner has acted as formwork.
[0136] Preferably said skeletal or lattice member is a corner moulding.
[0137] Preferably the external corner skeletal or lattice member is of a plastics material (eg. PVC).
[0138] Preferably window and/or door openings each have a head flashing to provide a canopy and that head flashing receives the inner mesh (ie. preferably holds the free ends of vertical wires of the mesh).
[0139] Preferably such flashings have end stopping (eg. flashing tape provided).
[0140] Preferably the flashings are of a plastics material (eg. PVC).
[0141] Preferably the head flashing is in part below the bottom ends of vertical battens and in part over a trim batten.
[0142] Preferably window and/or door openings have side jamb flashings.
[0143] Preferably each side jamb flashing locates a skeletal or lattice member (“side jamb skeletal or lattice member”) embedded at least in part by the plaster matrix.
[0144] Preferably each side jamb flashing is batten supported (at least in part).
[0145] Preferably each side jamb flashing is fixed to a trim batten or other batten.
[0146] Preferably window and/or door openings have a sill flange spanning between battens it is attached to.
[0147] Preferably a sill flashing (eg. of aluminium) overlays at least part of said sill flange.
[0148] Preferably the sill flashing is of “Z” section.
[0149] Preferably the sill flashing is of aluminium.
[0150] Preferably the sill flange has acted as a formwork periphery of the plaster matrix.
[0151] Preferably the top region of the sill flashing underlies the window frame (if opening is a window).
[0152] Preferably an inner mesh overlaps a flange of a wall bottom member (with preferably a drip edge).
[0153] Preferably the wall bottom member has two flanges, one to be positioned behind the bottom of vertical battens (and preferably to above any floor level) and one to be positioned over the same vertical battens and overlayed by the inner mesh.
[0154] Preferably the wall bottom member has acted as formwork for the plaster matrix.
[0155] Preferably the “Rules” hereafter described are or have been followed.
[0156] In another aspect the invention consists in a cavity wall type structure comprising:
a framing or a substructure, a paper or like wrap of such structure, battens supported from said framing or substructure but over said paper or like wrap, an inner metal mesh (preferably with its own paper) stapled or otherwise fixed to such battens, extra metal mesh attached to said battens and/or to the inner mesh outwardly of corners of openings, a second mesh (preferably a non-metallic mesh) as the (hereafter referred to as “outer mesh”) supported at least in part by a plaster matrix, mesh reinforcement (preferably a non-metallic mesh) of some regions with additional mesh as required by the Rules hereafter, and a plaster matrix that has been applied as more than one layer, at least one and preferably two layers having being applied prior to the association thereto of said outer mesh, the plaster matrix not showing any substantial amount of said outer mesh at the face surface to the outside of the building.
[0165] Preferably the plaster matrix is of at least a three layer application.
Preferably the inner metal mesh, extra metal mesh and the additional mesh reinforcement is in or to a base layer of the plaster matrix and the second mesh reinforcement is to a second layer of the plaster matrix.
[0167] In an aspect the invention is an in situ formed type stucco (ie. plaster matrix) panel of a building structure supported from cavity providing battens;
[0168] wherein the panel is supported (at least in part) from the battens by an embedded metal mesh (optionally and preferably of two layers in some areas) and the plaster matrix embeds, more outwardly than the metal mesh, another mesh (eg. of fibreglass) [optionally and preferably of two layers] in some areas;
[0169] wherein [optionally but preferably] the panel is about 21 mm thick;
[0170] and wherein the panel has no movement control joints;
[0171] and wherein the panel is of perimeter larger than 2.4 mm×4 m.
[0172] Preferably outwardly of corners of opening there is two layers of the metal mesh.
[0173] Preferably “Rules” as hereinafter described mandate use of an extra layer of the mesh more outwardly of the metal mesh and embedded into the base coat.
[0174] In still a further aspect, the invention consists in a building envelope having battens that support part or all of an in situ formed panel (preferably of about 21 mm thick);
[0175] wherein there is
an inner mesh attached to the battens, zonal reinforcement mesh outwardly of at least some corners of any openings in the panel, an outer mesh, different and/or same zonal reinforcement by a mesh, and a plaster matrix embedding all of the meshes; and wherein the outer mesh is of smaller opening size than both the mesh of the inner mesh and the zonal reinforcement mesh of each (or some) opening(s).
[0182] Preferably the Rules mandated mesh is of smaller opening size than the inner mesh.
[0183] In a further aspect the invention consists in a building envelope having battens that support part or all of an in situ formed panel (preferably of about 21 mm thick);
[0184] wherein there is
an inner mesh attached to the battens, zonal reinforcement mesh outwardly of at least some corners of any openings in the panel, an outer mesh different and/or same zonal reinforcement by a mesh, and a plaster matrix embedding all of the meshes; and wherein the outer mesh is of smaller opening size yet at least as flexible as the inner mesh and the zonal reinforcement mesh outwardly of each (or some) opening(s).
[0191] In a yet further aspect the invention consists in a building envelope having battens that support part or all of an in situ formed panel (preferably of about 21 mm thick);
[0192] wherein there is
an inner mesh attached to the battens zonal reinforcement mesh outwardly of at least some corners of any openings in the panel an outer mesh, different and/or same zonal reinforcement by a mesh, and a plaster matrix embedding all of the meshes; and wherein the Rules impose a mesh of smaller opening size than the inner mesh (or the inner mesh and the zonal reinforcement mesh outwardly of each (or some) corner(s)) for some spaces between openings (or elsewhere as the Rules mandate).
[0199] In yet another further aspect, the invention consists in a building envelope having battens that support part or all of an in situ formed panel (preferably of about 21 mm thick);
[0200] wherein there is
[0201] an inner mesh attached to the battens
zonal reinforcement mesh outwardly of at least some corners of any openings in the panel an outer mesh, different and/or same zonal reinforcement by a mesh, and a plaster matrix embedding all of the meshes; and wherein the perimeter of the in situ formed movement control jointed containing panel is other than square or rectangular; and wherein there is a Rule dictated movement control joint provided as a consequence of any significant departure of the square or rectangular perimeter.
[0208] In another aspect the invention consists in any of the assemblies, procedures, structures, NZ regulatory authority satisfying cavity wall stucco panels or the like substantially as herein described with or without reference to the “Rules” and/or with or without reference to any one or more of the accompanying drawings.
[0209] In a further aspect the invention consists in a building envelope having battens that support, part or all of an in situ formed panel of about 21 mm thick;
[0210] wherein there is
an inner mesh attached to the battens, a plaster matrix carried at least in part by the inner mesh and an outer mesh in turn supported, by embedment by the plaster matrix; and wherein any one or more of the preferments apply.
[0215] Preferably an envelope is further characterised in that the battens are supported from framing or a substructure.
[0216] Preferably that framing or substructure includes studs of timber, metal or other material.
[0217] Preferably the battens are fixed by penetrative fixers with preferably no fixing of the wire mesh is fully through a batten.
[0218] Preferably the panel reinforced by overlays of one or both the inner and outer mesh with further mesh reinforcing.
[0219] In another aspect the invention consists in a method of in situ formation of a reinforced plaster panel as cladding of a support structure, (eg. thereby to define a stucco type cavity wall structure) said method comprising or including the steps of
said fixing battens to the support structure, preparing for the panel creation
(A) by affixing a mesh (as an “inner mesh”) to the battens, and (B) providing prior to such affixing of the inner mesh, during the affixing of the inner mesh and/or after the affixing of the inner mesh, a periphery to co-act with the inner mesh as at least part of the formwork,
applying plaster into and onto the inner mesh and/or to or adjacent to the periphery to provide a base coat of plaster, after at least a partial set of the base coat, applying plaster onto the base coat as a second and levelling coat to the periphery, overlaying the second and levelling coat with a mesh (the “outer mesh”), by any suitable means (eg. trowelling and or otherwise) embedding or part embedding the outer mesh into the second and levelling coat, and applying a third plaster coat onto the second and levelling coat or the second and levelling coat and the at least partially embedded outer mesh; and wherein steps leading to any of the preferments are employed.
[0230] Preferably a building, cavity wall type structure, or stucco panel, of any of the previously defined or preformed forms is a result of such method.
[0231] The invention is also any product of such a method.
[0232] The invention is also, in combination, components suitable for or of any such product produced by such a method.
[0233] In another aspect the invention is a building structure comprising or including
framing of a pair of intersecting walls; battens outwardly (as herein defined with respect to internal or external intersections); a lower set of stucco panels cladding over some of the battens; a higher set of stucco panels cladding over some of the battens, there being a space defined between the lower and higher sets; and plural flashing members in and/or behind said space, including one flashing member that extends about the framing at the transition of framing for one of the intersecting walls to the other, in a mutual lapping condition flashing member to flashing member, affixed to the framing behind the lower regions of the higher set of panels and behind some of the battens, and extending over and down higher regions to the outside of the lower set of panels.
[0239] Preferably any one or more of the preferments herein referred to apply.
[0240] In still another aspect the invention is a building structure comprising or including:
framing of a pair of intersecting walls; battens outwardly (as herein defined with respect to internal or external intersections); a lower set of panels being of mesh reinforced plastered material(s), cladding over some of the battens and attached by the mesh at least to the battens and/or framing; a higher set of panels, being of mesh reinforced plastered material(s), cladding over some of the battens and attached by the mesh at least to the battens and/or framing, there being a space defined between the lower and higher sets; and plural flashing members in and/or behind said space, including one flashing member that extends about the framing at the transition of framing for one of the intersecting walls to the other, in a mutual lapping condition flashing member to flashing member, affixed to the framing behind the lower regions of the higher set of panels and behind some of the battens, and extending over and down higher regions to the outside of the lower set of panels.
[0246] Preferably any one or more of the preferments herein referred to apply.
[0247] In still another aspect the invention is a building structure of a stucco type comprising or including:
framing of a wall; battens on said framing; a horizontally spaced pair of in situ formed panels cladding over said battens on said framing, the pair of panels defining a vertical movement control joint wherein the vertical movement control joint is being a vertically extending space bounded by opposing edges of each panel, and a vertically extending flashing having
(i) a zone (“zone 1”) underlying, as a flange, each proximate edge region of a panel but over a said batten; (ii) a zone (“zone 2”) from each flange-like zone facing and/or keying to the edge of the panel; and (iii) a zone (“zone 3”) of allowing flexure horizontally between zones (i), zones (ii) or zones 1 and 2.
[0255] Preferably any one or more of the preferments herein referred to apply.
[0256] In yet another aspect the invention is a side jamb assembly of or for a peripherally framed glazed or glazable assembly of a stucco type structure, the side jamb assembly having:
at least one framing member vertically extending about the opening to be glazed and dressed; at least one batten vertically extending from said framing members; a first extruded flashing affixed to at least one batten to underlie in part behind an inserted, or to be inserted, peripherally framed glazed or glazable assembly, and a second extruded flashing outwardly of but extending laterally to the first extruded flashing, and affixed to at least one batten.
[0261] Preferably any one or more of the preferments herein referred to apply.
In still another aspect the invention is a sill flashed window or door assembly of a stucco type building structure:
[0263] wherein a “Z” type flashing has
an upper flange behind part of each side jamb flashing extending down towards the median part of the “Z” form; an upturn of each partly freed end region of the median part, rising as it extends rearwardly from the lower flange, to or towards the upper flange, and each such upturn is sealed to the upper flange.
[0267] Preferably any one or more of the preferments herein referred to apply.
[0268] In still a further aspect the invention is a head flashed window or door assembly of a building structure of a stucco type:
wherein there is a ‘Z’ type head flashing with its median part and lower flange at each end overlying a top part of a side jamb flashing; and wherein a flashing tape from (preferably under) the median part at each end of the ‘Z’ type head flashing is captured above the median part of the ‘Z’ type head flashing as at least part of a stop-end of an extruded still like drip edge extrusion as a flashing above both the median part and lower flange of the ‘Z’ type head flashing.
[0271] Preferably any one or more of the preferments herein referred to apply.
[0272] As used herein the term “and/or” means “and” or “or”. In some circumstances it can mean both.
[0273] As used herein the term “(s)” following a noun means one or both of the singular or plural forms.
[0274] As used herein “stucco” or “stucco panel(s)” includes (but is not limited to) any batten fixed mesh carrying a plaster matrix which itself embeds a mesh more outwardly of the batten fixed mesh, the panel(s) having been in situ formed to structure or frame carried battens.
[0275] Preferably regional reinforcement by one or both meshes being overlayed is provided.
[0276] As used herein the term “wrap” and related words) in respect of the first or inner mesh envisages, but is not limited to, discrete mesh expanses being placed (preferably with lapping) to provide an inner mesh support wheresoever there is to be the laying up of the plaster system.
[0277] As used herein “mesh” includes any lath or indeed alternatives such as any suitable perforate sheet. Preferably in respect of the batten fixed “inner” reinforcement it is of metal substantially as herein described. However in other variants it can be of, for example, stainless steel. The term “mesh” (or indeed the alternatives referred to) where not the batten fixed “inner” reinforcement or fixed regional reinforcement preferably is of a suitable glass or plastics fibre or at least derived from such materials (i.e. glass or plastics). In still other less preferred embodiments it can be of metal.
[0278] As used herein, the term “regional” means less than coextensive with the whole panel (minus openings). The preferred inner and outer reinforcements that are preferably so coextensive are “nonregional” in that sense.
[0279] As used herein “plaster” or “plaster matrix” can include (but is not restricted to) in the same panel, the same or different “plaster” for different layers of application.
[0280] For example MCL® Stucco Rite® System plaster mixes. Such as, in sequence, NZ660 Multicoat cement plaster (pumped, and trowelled only after outer mesh placement) and top coat layer NZ660 Multicoat cement plaster (hand skimmed) and sponge finish.
[0281] Alternatively, a water repellent plaster sealer may be applied as a seal to the second layer and a top coat of a finishing plaster applied [e.g. MCL® Stucco Rite® AL40 SP Polymer Modified Finishing Plaster.
[0282] A water repellent plaster sealer may be applied prior to full set. A final waterproof coating can be applied post set.
[0283] To those skilled in the art to which the invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the scope of the invention as defined in the appended claims. The disclosures and the descriptions herein are purely illustrative and are not intended to be in any sense limiting.
BRIEF DESCRIPTION OF THE DRAWINGS
[0284] One preferred form of the present invention will now be described with reference to the accompanying drawings in which
[0285] FIG. 1 shows in isometric a preferred moulding (or if an extrusion preferably with added machining) to provide for leakage bottom preferably with a drip edge (eg. as in our NZ Registered Design 408975),
[0286] FIG. 2 shows in isometric a moulding (or extrusion preferably optionally with machining) suitable for use for the window and door head, and which also provides a drip edge (eg. as in our NZ Registered Design 408975),
[0287] FIG. 3 shows a soffit or sill flange (eg. as in our NZ Registered Design 408977) able to be extruded,
[0288] FIG. 4 shows a jamb flashing able to be extruded (eg. as in our NZ Registered Design 408976),
[0289] FIG. 5 shows a vertical movement control joint extrusion (eg. as in our NZ Registered Design 408978),
[0290] FIG. 6 shows a preferred form of mesh to be used as the first or inner mesh, the mesh having a full or partial paper backing,
[0291] FIG. 7 shows a variety of horizontal movement control joints each in the form of a Z flashing and with complementary components able to accommodate for both external and internal corners of the outer cladding of the building envelope, FIGS. 60-72 show these components in more detail,
[0292] FIG. 8 shows a typical batten for use in the framing or substructure in accordance with the present invention, such battens for example being treated to H3.1 or H3.2,
[0293] FIG. 9 shows a typical framing radiata pine dwang treated to H3.1 or H3.2,
[0294] FIG. 10 shows a typical stainless steel ring grip nail (for example of 75 mm×2.8 mm diameter) for insertion into battens and/or framing components,
[0295] FIG. 11 shows a typical hot dipped galvanised round head nail (for example 20 mm×2.8 mm) used in some of the subassemblies or assemblies hereinafter depicted,
[0296] FIG. 12 shows a typical stainless steel staple (for example of at least 1.6 mm diameter) able to be used to locate the inner mesh to the dwangs,
[0297] FIG. 13 shows a typical flashing tape to be used,
[0298] FIG. 14 shows a typical silicone sealant dispenser,
[0299] FIG. 15 shows a typical wall wrap which can be used between the framing members and dwangs such as in FIG. 9 and the battens (such as shown in FIG. 8 ),
[0300] FIG. 16 shows the Z form flashings preferably of powder coated aluminium that can be used as head or sill Z flashings,
[0301] FIG. 17 shows a typical timber framing layout typically of double stud adjacent openings and with dwang spacings of 900 mm or less, typical dwang sizes being 45 mm×90 mm or larger with the stud sizes being complementary,
[0302] FIG. 17A shows nominal stud spacings of 600 mm, nominal dwang spacings of 90 mm centres and batten placement on each stud and midway (i.e. at about 300 mm) between studs.
[0303] FIG. 18 shows framing such as shown in FIG. 17 wrapped with the moisture barrier wall wrap of FIG. 15 , also showing the use of flashing tape about the openings,
[0304] FIG. 19 shows a concrete floor slab and its juxtaposition to the bottom member depicted in FIG. 1 ,
[0305] FIG. 20 shows a batten layout for a double level wall showing with the detailing head, from the top left in a clockwise sense, the sill detail, the head batten detail and the butt joint on a double dwang,
[0306] FIG. 21 is an elevational view detailing the positioning of the sill flange and its relationship to the sill Z flashing,
[0307] FIG. 22 details the side jamb flashing,
[0308] FIG. 23 shows the elevation of the head Z flashing in its subassembly,
[0309] FIG. 24 shows the soffit flange in elevation in its subassembly,
[0310] FIG. 25 shows in elevation where it is a movement control joints meets a horizontal movement control joint, the Z flashing extending horizontally,
[0311] FIG. 26 is a plan view of the vertical movement control joint and its relationship to the inner metal mesh, the outer fibreglass mesh, the plaster matrix and the battens,
[0312] FIG. 27 shows, to the bottom right of an opening, how sheets of inner mesh substantially as depicted are lapped and are fixed by staples to the underlying battens through the carried paper,
[0313] FIG. 28 shows some metal mesh, without the paper being used, as a zonal reinforcement overlay or reinforcement “patch” outwardly of the opening at each corner, such square mesh being laid diagonally in order to provide strength in directions other than primarily the vertical and horizontal, outer fibreglass mesh is then laid outwardly of the metal mesh.
[0314] FIG. 29 is a typical detail of the bottom of a door,
[0315] FIG. 30 shows an inner mesh and inner mesh corner reinforcement at the head of an opening,
[0316] FIG. 31 shows a similar arrangement for the bottom of an opening (in this case a window),
[0317] FIG. 32 shows a typical mesh to be used as the outer mesh (typically of fibreglass),
[0318] FIG. 33 shows a gun applying a second layer of plaster onto the first layer or base layer of plaster which has passed through the inner mesh and has attached at least in part to the inner mesh,
[0319] FIGS. 34A and 34B show the skeletal or lattice external corner members (eg. as in our NZ Registered Design Application 408974) positioned respectively to the top of the wall and to the bottom of the wall over the inner mesh,
[0320] FIGS. 34C and 34 D show the skeletal or lattice flange members positioned to the side of a window opening,
[0321] FIG. 35A shows the skeletal or lattice-like flange member (eg. of NZ408974) for use with each window and door opening,
[0322] FIG. 35B shows a jamb flashing (as in our NZ Registered Design Application 408976) able to locate and anchor one part of the skeletal or lattice flange of FIG. 35A ,
[0323] FIG. 36 shows the combination of the two components of FIGS. 35A and 35B with the flange toeing into and being kept located by a shoulder of the side jamb flashing, the lattice region of the flange being able to be fixed by nail into a batten,
[0324] FIG. 37 shows an exploded diagram able to explain spacially how various components cooperate when an opening is to be glazed,
[0325] FIG. 38 shows in part the application of a mesh, as shown in FIG. 2 , over part of the lattice region of the flange of FIG. 35A ,
[0326] FIG. 39 shows the location of the lattice flange of FIG. 35 relative to a sill of a window opening,
[0327] FIG. 40 shows a base coat plaster being applied and using in part the lattice region to the nose of the member of FIGS. 34A , 34 B and 35 substantially as both reinforcement and formwork,
[0328] FIG. 41 shows the trowelling in of the outer mesh (as shown in FIG. 32 ) subsequent to the application of the second coat shown being applied in FIG. 33 ,
[0329] FIG. 42 shows a plan view of the relationship of the components of the cavity wall system of the present invention,
[0330] FIG. 43 shows a vertical section of the detail shown in FIG. 42 ,
[0331] FIG. 44 shows in elevation the detailing with respect to a soffit,
[0332] FIG. 45 shows in more detail the arrangement previously shown in FIG. 19 ie. the concrete foundation and base detail,
[0333] FIG. 46 shows in plan the detail of an external corner, there being seen the lattice and nose providing corner member as shown in FIGS. 34A , 34 B and 35 ,
[0334] FIG. 47 shows an internal corner (ie. internal only in the sense that it is still part of the exterior of the wall structures), no similar (but complementary) lattice member to that as depicted in FIG. 34A , 34 B or 35 being necessary,
[0335] FIG. 48 shows head detail in elevation,
[0336] FIG. 49 shows sill detail in vertical section,
[0337] FIG. 50 shows jamb detail in plan,
[0338] FIG. 51 shows in vertical section the bottom of a door to deck with some sill detail,
[0339] FIG. 52 shows the bottom of a door to deck with flush detail,
[0340] FIG. 53 shows, in vertical section, a horizontal movement control joint between different wall levels (ie. its position optionally at an intermediate floor location),
[0341] FIG. 54 is a three dimensional view of a break away drawing of some features of the present invention,
[0342] FIG. 55 shows a vertical movement control joint meeting a horizontal movement control joint, all in vertical section,
[0343] FIG. 56 shows bottom drip edge detail to a flat roof wall, all in elevation.
[0344] FIG. 57 shows the plan section through a jamb to a typical door,
[0345] FIGS. 58 A through 58 MMM show diagrams and detail (herein incorporated as text hereof by reference) appropriate for application of certain rules (“Rules”) as to movement control joint (“MCJ”) location and extra fibreglass mesh reinforcement placement, such extra fibreglass being insertable by, for example, trowelling of it into an unset plaster layer, preferably the base coat layer.
[0346] FIG. 59A shows MCL® Stucco Rite® NZ660 multicoat cement plaster in 25 kg bags,
[0347] FIG. 59B shows MCL® Stucco Rite® A140 SP polymer modified finishing plaster in 25 kg bags & pre-mixed in plastic buckets,
[0348] FIG. 59C shows MCL® water repellent plaster sealer in plastic containers,
[0349] FIG. 59D shows MCL® fibreglass mesh 1×50 m rolls 160 grams per square metre,
[0350] FIG. 59E shows a MCL® uPVC Kwik™ corner,
[0351] FIG. 59F shows a MCL® uPVC Kwik™ flange for windows and doors,
[0352] FIG. 59G shows a MCL® Stucco Rite® mortar pump (G5C),
[0353] FIG. 59H shows a MCL® Stucco Rite® pump (Blitz),
[0354] FIG. 59I shows a MCL® Stucco Rite® Mortar Pump (Ritmo),
[0355] FIG. 60 shows a straight joiner moulding,
[0356] FIG. 61 shows a ‘Z’ flashing aluminium extrusion,
[0357] FIG. 62 shows a straight joiner moulding joining two ends of ‘Z’ flashing aluminium extrusions,
[0358] FIG. 63 shows a front view of the assembly of FIG. 62 , and shows the location of the cross section A-A,
[0359] FIG. 64 shows an end view of the assembly of FIG. 62 ,
[0360] FIG. 65 shows the cross section view A-A of FIG. 63 , and shows the location of the detail ‘B’,
[0361] FIG. 66 shows the detail ‘B’ of FIG. 65 ,
[0362] FIG. 67 shows a corner joiner moulding (as moulded), which is reversible to suit both external and internal corner configurations via the use of packers,
[0363] FIGS. 68A and 68B shows corner joiner packer mouldings which can be clipped into the corner joiner moulding of FIG. 67 for the external corner configuration,
[0364] FIG. 69 shows an external corner joiner assembly with packers clipped into place,
[0365] FIG. 70 shows an end view of the external corner joiner assembly of FIG. 69 ,
[0366] FIG. 71 shows an internal corner joiner assembly, no packers are required,
[0367] FIG. 72 shows an end view of the internal corner joiner assembly of FIG. 71 .
DETAILED DESCRIPTION OF THE INVENTION
[0368] The existing MCL StuccoRite® Cavity Wall Cavity System is a masonry cladding system incorporating a 35 mm vented cavity, comprising of special pre-papered steel mesh fixed to H3.1 treated timber battens, incorporating flashings for openings and penetrations, control joints, H3.1 treated fixing blocks, plus a proprietary cementitious render. The cladding system is installed on timber framing that complies with NZS3604 protected by a building wrap and protected by a building wrap and pre-qualified window sealing tape that complies with Table 23 of E2/AS1 and BQI interim Performance Standard BQI C4021*. The render is protected from the weather with a coating system complying with BQI interim Performance Standard C5031*.
[0369] In the opinion of BEAL, the MCL StuccoRite® Cavity Wall Cavity System (known as MCL StuccoRite®) and when installed according to the MCL StuccoRite Technical Manual dated January 2006, will meet the following performance requirements of the Building Code:
Clause B1—Structural Integrity (including to NZS3604: 50 m+wind speed) Clause B2—Durability Claims C—Spread of Fire (resistance) Clause E2—External Moisture
[0374] The present invention is an evolution of that system.
[0375] The current system of the invention comprises proprietary plaster, reinforced with pre-papered hot dipped galvanised zinc steel wire MCL® StuccoRite® Mesh Sheet and other reinforcement, to achieve a nominal thickness of 21 mm with a standard sponge or plastic float finish. The plaster is applied by MCL® StuccoRite® Mortar Pumps over the mesh which is stapled to 35 mm×40 mm nominal sized H3.1 or H3.2 treated vertical timber battens providing a ventilated and drained cavity.
[0376] The proprietary plaster is applied in three coats; a base coat, a levelling coat, and the top coat. The base coat encapsulates the pre-papered MCL® StuccoRite® Mesh Sheet reinforcement as well as additional reinforcement at corners and around joinery. The levelling and mesh coat contains further reinforcement in the form of fibreglass mesh (MCL® Fibreglass Mesh).
[0377] The final skim coat is sponge or plastic float finish.
[0378] The MCL® StuccoRite® Mesh Sheet is fabricated from copper bearing cold drawn hot dipped galvanised zinc vertical face wires and horizontal back wires, electrically welded at all points of intersection. The zinc coating is not less than 27.9 g/m 2 .
[0379] The face and back wires are 1.5 mm diameter with openings not exceeding 51 mm. A layer of absorptive, slot perforated paper is placed between the face and back wires. The mesh is self furring by being fabricated horizontally into the lath at 152 mm centres with a 6.5 mm crimp in each face wire at its intersection with double back wires. A layer of Type 1, Grade D, Style 2 black building paper in compliance with UBC Standard No. 17-1 is strip glued to the back of the high absorbent slot perforated paper and is extended 100 mm beyond the lath at the left end of the sheet and 100 mm beyond the upper long edge of the sheet.
[0380] Reinforcement at all external corners is provided by MCL® uPVC Kwik corners being a 55 mm×55 mm angle with nosing and MCL®uPVC Kwik flanges, being 65 mm×15 mm angles with nosing, provide reinforcement at window and door openings.
[0381] MCL®Fibreglass Mesh is contained locally at certain openings in the base coat and continuously in the levelling and mesh coat. The MCL®Fibreglass Mesh is alkali resistant and woven with a 4 mm×4 mm aperture weighing not less than 165 grams per square mere.
[0382] The edges of the plaster are formed and supported by a number of uPVC mouldings. The MCL® Bottom J-Mould with Drip Edge and the MCL® Window/Door head with Drip Edge also provide vermin proofing and allow for drainage and ventilation to the cavity.
[0383] Movement is accommodated by providing physical breaks in the plaster. This is achieved with a uPVC moulding for the vertical movement control joint (VMCJ) and with a uPVC window head moulding and Z flashing for the horizontal movement control joint (HMCL).
[0384] Joinery shall comply with the requirements of E2/AS1 and be flashed with head and sill Z flashings as described in this Appraisal.
[0385] To provide a moisture resistant surface the completed plaster is sealed with the MCL® Water Repellent Plaster Sealer. The MCL® StuccoRite® System is completed by being waterproofed with the application of not less than a 2 coat paint system in accordance with Paragraph 9.3.7 of E2/AS1.
[0386] Components and consumables of the new system are preferably:
[0000] Battens—No. 1 framing, rough sawn or gauged 35 mm×40 mm Radiata Pine treated to H3.1 or H3.2.
Tolerance shall be + or −3 mm on both dimensions.
No. 1 framing Radiata Pine dwangs treated to H3.1 or H3.2. Minimum gauged 45 mm×90 mm.
Wall wrap complying with Table 23 of E2/AS1.
Flashing tape complying with Paragraph 4.3.11 of E2/AS!.
Powder Coated Aluminium Z flashings at head and sill of joinery.
Plain Aluminium Z flashing at garage door heads.
Mesh staples to the battens shall not be less than 1.6 mm diameter, 38 mm×9.5 mm or wider type 304 stainless steel gundriven divergent point staples.
Batten nails shall be not less than 75 mm long×2.8 mm diameter ring grip 304 stainless steel gun driven nail.
20 mm×2.8 mm diameter hot dipped galvanised round head nails.
Sealant to soffit, window/door jambs, HMCJ jointers and corners, meter box and all penetrations as per Paragraph 4.5.2 (g) of E2/AS1 which is a neutral cure silicone sealant.
At meter boxes 20 mm×20 mm×0.75 mm aluminium angle.
At decks:
M12 bolt with nut and washers; all Type 304 stainless steel length to suit.
50 mm×50 mmsq.×3 mm washer with 14 mm diameter hole, Type 304 stainless steel. 50 mm×50 mm sq.×3 mm EPDM washer.
10DN PVC Sleeve 22 mm long.
Saddle flashings as described in NZS 3604 and E2/AS1 can be used but to the dimensions described herein. Flashing material shall comply with Clause 4.10.2 of NZS 3604 or the ‘50 year’ requirement of Table 20 in E2/AS1.
Proprietary Type 304 Stainless Steel Joist Hanger minimum shear strength half span x spacing×3.35 kn (for 2.0 kpa Deck) or 4.85 kpa (for 3.0 kpa Deck)
140 mm×140 mm sq.×13 mm fibre cement board with 14 mm diameter hole.
Aluminium Z Flashings and uPVC Mouldings
MCL® Plain Aluminium deck and HMCJ Z flashings including uPVC Jointers and Corners to the HMCJ Z flashings all as described in the Technical Manual.
MCL® uPVC Bottom J-Mould with Drip Edge
MCL® uPVC Window/Door head with Drip Edge
MCL® uPVC Soffit/Sill Flange
MCL® uPVC Side Jamb Flashing
MCL® uPVC Vertical Movement Control Joint
Plaster and Sealer:
[0387] MCL® StuccoRite® NZ 660 Multicoat Cement Plaster (25 kg bags)
MCL® StuccoRite® AL 40 SP Polymer Modified Finishing Plaster (25 kg bags and pre-mixed in plastic buckets).
MCL® Water Repellent Plaster Sealer in plastic container.
Reinforcement
[0388] MCL® StuccoRite® Mesh Sheets by K-Lath Division of Tree Island Steel Inc, Monrovia California Fed. Spec. QQ-L-10c. (2.180 m×0.7 m)
MCL® uPVC Kwik Corner Reinforcing
MCL® uPVC Kwik Flange Reinforcing
MCL® Fibreglass Mesh with 4 mm×4 mm apertures and weighing 160 g/sqm (1 m×50 m rolls).
The MCL® plaster shall be mixed with potable water and applied to walls by a MCL® StuccoRite® Mortar Pump. These electric powered rotor/stator pumps are as shown in the Technical Manual and are supplied for purchase or hire by MCL®.
[0389] Materials for use as the plaster system are available from Mineral Coatings (NZ) Limited.
[0390] The MCL® StuccoRite® System requires a continuous concrete foundation or slab edge thickening under all walls.
[0391] The MCL® StuccoRite® System is intended to be fixed to timber walls with studs at 600 mm centres, heights up to 4.8 m and dwangs spaced at up to 900 mm centres. An additional dwang is required at soffit level as described in the Technical Manual.
[0392] The system is able to resist wind face loading up to and including those associated with VH wind speed zones.
[0393] The weight of the total system is 41 kg/m 2 and does not contribute to the building lateral bracing.
[0394] The system may be fixed to wet timber framing provided the interior lining and insulation is not installed until the framing moisture content is less than 18%.
[0395] The location of Movement Control Joints (VMCJs) shall be shown on the consented building elevations in compliance with the Rules.
[0396] Vertical Movement Control Joints (VCNJ's) shall be provided at changes in elevation, at openings and to break the length of a wall into sections no wider than 8 meters or 2.75 times the panel's height all as required by the Rules hereafter. Where VMCJ's are required they shall not be located any closer than 175 mm to any penetrations including those for windows or doors.
[0397] Horizontal Movement Control Joints (MMCJ's) shall be provided at intermediate floor level where the moisture content of flooring timbers or wall plates abutting the intermediate floor is greater than 18%. Checks on moisture content shall be conducted prior to plastering commencing to ensure this requirement is met.
[0398] Where battens extend continuously past an intermediate floor (i.e. with no provision for a HMCJ) and checks before plastering reveal a moisture content higher than 18% then either the wall shall be re-battened allowing for the provision of a HMCJ at intermediate floor level or plastering operations shall be delayed until such time as the moisture content has dropped to 18% or less.
[0399] In addition to any HNCJ that may be required at the intermediate floor level, HMCJ's shall be provided at horizontal steps and to break the height of the wall into panels with a maximum average height of 5 meters except at gable ends and other certain narrow panels all as required by the Rules hereafter. Where HMCJ's are required to limit height they shall be located at an intermediate floor as shown herein.
[0400] The MCL® Stucco Rite® System allows for the construction of decks, simply supported or cantilevered. The requirements of NZS 3604 must be followed except to extent required to account for the junction.
[0401] Whilst specific materials have been specified for various employments herein, various consumables in so far as the reinforcement attachment and building up the matrix, a person skilled in the art will appreciate other alternatives that might exist Likewise in respect of any weather proofing of the plaster matrix other options to those described or described in the aforementioned website can be used.
[0402] FIG. 1 shows a preferred bottom member 1 preferably of a small uPVC and having two main flanges and a drip edge as well as openings 1 A for moisture drainage purposes.
[0403] FIG. 2 shows, similarly of a uPVC material, a member able to act as a window and door head. This member 2 also has a drip edge feature 2 A and moisture drainage openings 2 B for use in the assembled condition shown in FIG. 55 as an example.
[0404] FIG. 3 shows a soffit and sill flange 3 , preferably also of uPVC.
[0405] FIG. 4 shows a member 4 which can act as a jam flashing. This also is preferably of uPVC.
[0406] FIG. 5 shows a preferred member, preferably also of uPVC, able to be used to provide a vertical movement control joint. This member with its bellows like central region and its two flanges (each with openings to facilitate water migration and/or fixing) is used in the manner as shown in FIG. 26 .
[0407] FIG. 6 shows MCL® Stucco Rite® zinc coated mesh sheet typically of 2.180 m×0.7 m double wire. This wire mesh is used as the inner mesh 6 and is laid with overlapping over battens 8 to be stapled by staples 12 .
[0408] The same mesh, without the paper backing shown in FIG. 6 , can be used for the reinforcement requirements at the corners herein described. These reinforcement members 23 likewise can be stapled to battens or can be tied to the existing mesh 6 , or both.
[0409] FIG. 7 shows aluminium control joint members showing assemblies of corner elements with straight flashing portions. The Z form flashing members 7 are used as part of the horizontal movement control hereinafter described. Shown as 7 A and 7 B respectively are assemblies of such components for use on an inside exterior corner and an outside exterior corner respectively.
[0410] FIG. 8 shows a typical rough sawn treated batten as foresaid typically 35 mm by 40 mm.
[0411] FIG. 9 shows a typical dwang component 9 preferably of minimum size 45 mm by 90 mm for use with the framing (typically shown in FIG. 17 ).
[0412] FIG. 10 shows a typical nail 10 that can be used in the system to secure battens to the under lying building structure or wooden frame such as shown in FIG. 17 .
[0413] FIG. 11 shows nails 11 able to be used to secure some of the flashing components and other components as hereinafter described.
[0414] FIG. 12 shows a staple 12 able to be used to secure the mesh 6 to the underlying battens 8 as hereinafter described.
[0415] FIG. 13 shows flashing tape 13 used, for example, in a manner shown in FIG. 18 in connection with the wall wrap 14 .
[0416] FIG. 16 shows powder coated aluminium head and sill Z flashings 15 used as hereinafter described.
[0417] FIG. 17 shows, by way of example, a simplified frame of studs, paired about openings and provided with appropriate dwangs.
[0418] Preferably the studs are at 600 mm centres or less.
[0419] Preferably the gaps between bottom plates and dwangs and between dwangs is a maximum of 900 mm.
[0420] The underlying frame as shown in FIG. 17 is then wrapped with the wrapping material 14 as already used in the Stucco Rite® system. The flashing tape 13 is applied as shown about a window opening 16 and door opening 17 .
[0421] Battens 8 are then applied over the surface. These battens are shown over the wrap as shown in FIG. 8 . Battens are paired alongside openings and are elsewhere spaced vertically such that there is a batten to all studs and in between. The maximum batten spacing is 300 mm.
[0000] The batten fixing with nails 10 is shown in FIG. 20 for a two level structure, the transition between the two levels being shown.
[0422] The construction method is preferably as previously stated. This results in a bottom panel near a foundation or concrete slab 18 having a batten 8 nailed by nails 10 into a floor plate on the slab 18 with building paper 14 interposed. A bottom member 1 as in FIG. 1 is located with its flanges as shown in FIG. 19 and nailed by nails 11 to the floor plate. In turn the inner metal mesh 16 is fixed to the battens 18 by staples 12 thereby to allow a sequence of applications of plaster to provide the build up of a plaster matrix 20 (preferably of three layers) which also embeds the fibreglass mesh 19 .
[0423] FIGS. 21 and 22 shows similar arrangement for the use of a sill flange and the side jam flashing.
[0424] In FIG. 21 the steam attached to a batten by nail a sill flange 3 and in turn its been overlayed so as to provide a canopy effect by a head flashing 15 or 7 .
[0425] FIG. 22 shows in plan a double batten arrangement 8 into a double stud arrangement about a window or door opening. Shown is a lattice like member 21 toed as in Figure?
[0426] In FIGS. 35A to 36 show the side jam flashing 4 , the lattice providing member 21 (preferably also of a PVC material) to be used in position substantially as shown in FIGS. 38 and 39 . Shown in part in FIG. 38 is the outer mesh 19 overlying the lattice type member 21 .
[0427] With reference to FIGS. 35 to 36 jamb flashing 4 may be installed flush with the inner window trim edge. The window flange 21 can then be fitted, by clipping the window flange 21 into the vertical groove of the jamb flashing 4 . Nails/clouts 11 can then be used to fasten the window flange 21 in place.
[0428] FIG. 37 shows in respect of an opening how a side jam member 4 is to be used to underlie the canopy of the to be fitted head flashing 7 . This position alongside an opening and to battens subsequently enables lattice member 21 to be toed in for nail fixing.
[0429] Incidentally FIG. 37 shows bevelled battens 8 to allow both the top 13 (and the end-stop tape 13 A) and the top region of flashing 7 under the battens 8 .
[0430] Later drawings show other preparative arrangements and the resultant stucco panels.
[0431] A feature that enables the satisfying of likely regulatory requirements for such larger size panels (albeit nominally of 21 mm thickness) is all as shown. A major requirement is not to take panels beyond an approved size without moving control joints or by satisfying the reinforcement requirements (that preferably involves the use of an extra amount of mesh as dictated by the Rules hereinafter described) and the movement control joint requires (also as dictated by the Rules).
[0432] FIG. 44 shows soffit 25 positioned relative to an underlying panel of the system, the soffit 25 being overlayed by a timber member 35 .
[0433] FIG. 51 shows flooring 30 over blocking 31 in relation to an in situ formed panel. FIG. 52 similarly but note the set down option.
[0434] FIG. 53 shows a HMCJ below flooring 30 and a joist 32 . Shown is a top plate 33 and a stud 26 . Also a bottom plate 34 .
[0435] The bevelling of battens 8 can be seen in a number of locations to accommodate flashing taped flashings.
[0436] The usual method of construction can be seen by reference to our website mentioned previously.
[0437] Shown, by way of example, in FIG. 1 is an already applied basecoat A over and through the mesh 6 and any additional regions of mesh 23 as mandated outwardly of each corner.
[0438] The second layer B is being shown applied in FIG. 3 and this is the region on to which mesh 19 is positioned and trowelled in as shown in FIG. 41 .
[0439] Any extra mesh material (e.g. of preferably a similar type to 19 ) mandated by the Rules is positioned on or applied into the base layer A (e.g. by a similar technique to that shown for mesh being positioned into layer B). This is in addition to the mesh 23 requirements.
[0440] Once the mesh impregnated layer B has been smoothed the third coat can then be applied thereby to leave the plaster matrix ready for finishing in a manner as previously described. For example any suitable preset/post set water repellent/resistance coating system.
Rules for MCJ Location and Fibreglass Mesh Reinforcing
[0441] For the purpose of these Rules the alphanumeric and numeric content of the appended drawings is here included by reference.
[0442] The location of movement control joints, both vertical (VMCJ) and horizontal (HMCJ), and additional Fibreglass Mesh into the basecoat, all is required by these Rules, shall be shown on plans and specifications.
[0443] With stucco extending vertically from the base of the wall (i.e. bottom member of FIG. 1 ) to the top of the wall (i.e. soffit flange shown in FIG. 44 ) and horizontally between external or internal corners (see FIGS. 46 and 47 ) it shall be divided (where size of panel dictates) into wall panels by means of horizontal (HMCJ) and vertical (VMCJ) control joints (see FIG. 25 and FIG. 26 ) as required by the following Rules.
[0444] The width and average height of a wall panel shall be measured between the control joints or the stucco edges (base soffit or internal/external corners) that bound the wall panel.
[0445] For the purposes of these Rules the locations and dimensions of the “openings” shall be measured to the plasters' edge.
[0446] Rule 1 A VMCJ, as required by these Rules, shall extend from the bottom member of FIG. 1 or a HMCJ of FIG. 25 up to the soffit or upper HMCJ. A HMCJ shall extend the full width of the wall panel and around internal or external corners along the adjacent wall panel to a VMCJ. A HMCJ does not have to extend beyond a VMCJ.
[0447] Rule 2 A VMCJ is required:
a) At each end of all openings wider than 3 m or higher than 1.95 m. the VMCJ's shall be placed no further than 300 mm from each side of the openings except a VMCJ is not required if the openings is closer than 600 mm from an internal or external corner or when Rule 10 applies. b) At a change in wall heights except as allowed by c) below. c) Where a change of direction occurs in either the top or bottom of the MCL®Stucco Rite® wall panel and the angle between the panel surfaces, as shown in the figures below, is less than 135°. A vertical offset (angle is 90°±20°) up to 600 mm long does not require a VMCJ.
VMCJ required at the locations shown in broken lines in each of FIGS. 58A to 58D . FIGS. 58A and 58B is for vertical offset lower and upper edge where height greater than 600 mm. FIGS. 58C and 58D were offset lower and upper edge at angle between surfaces less than 135°.
[0451] Rule 3 Install a HMCJ at any horizontal step in a wall panel where the width of the step is wider than 600 mm. For steps less than 600 mm embed a 400 mm square of fibreglass mesh in the basecoat diagonally across the step.
[0452] Rule 4 HMCJs shall be provided at intermediate floor level where, at the time of plastering, the moisture content of flooring timbers or wall plates abutting the intermediate floor is greater than 18%. In addition, HMCJs at intermediate floor level shall be provided where necessary to ensure the requirements on panel height are met.
[0000] The maximum average height of a MCL® Stucco Rite® wall panel shall be 5.2 m except in the following situations where the maximum height of the wall panel shall be 7 m:
a) Panels wider than 2.5 m and less than 6 m with a monoslope top edge of angle greater than 11° from the horizontal, and b) Panels wider than 4, and less than 8 m with sloping top surfaces of angle greater than 11° from the horizontal forming a gable with the apex located within the middle third of the panel width. c) The Z-Flashings below a cantilevered timber deck, as required by on page and shown on drawing is also a HMCJ.
[0456] Rule 5 Not withstanding the above Rules, the maximum width (L) of a wall panel shall not be greater than 2.75 times its height or 8 m.
[0457] Rule 6 A minimum separation distance of 175 mm shall be provided between the following:
a) VMCJ's and openings b) VMCJ's and corners (internal or external) c) VMCJ's d) Openings e) Openings and corners (internal or external) f) Corners (internal or external)
[0464] In all situations above where the separation distance is less than 300 mm provide a layer of fibreglass mesh in the basecoat over the full length of the separation distance. Where the separation distance is at an opening extend the mesh 300 mm beyond each end of the opening. See FIG. 58E onwards.
[0465] If the separation between openings is not horizontal or vertical but instead at some angle then the layer of fibreglass mesh in the basecoat shall extend out perpendicular to that angle, in both directions, over the full width of the separation for a distance of at least twice the separation distance. See FIG. 58E onwards (particularly FIGS. 58H to 58I ).
[0466] Rule 7 When the sum of the opening heights (Σh) in a wall panel exceeds 40% of the wall panel's average height (H) then reduce the wall panel's width to not greater than 6 m. When determining the sum, openings separated horizontally by 900 mm or less shall be included as shown in FIG. 58E onwards.
[0467] Rule 8 When the ratio Σh/H as determined by Rule 7 exceeds 80% of the wall panel average height then in addition to meeting the Rule 7 a VMCJ shall be provided no further than 300 mm from each side of all openings. A VMCJ is not required if the opening is closer than 600 mm from an internal or external corner or when Rule 10 applies. See FIGS. 58H to 58I ).
[0468] Rule 9 When the sum of the opening widths (Σb) exceeds 60% of wall panel width (L) then a layer of fibreglass mesh embedded in to the basecoat, shall be provided between all openings between openings and the panels edges extending from 300 mm above to 300 mm below he openings. When determining the sum, openings separated vertically by 900 mm or less shall be included as shown in FIG. 58E onwards (particularly FIGS. 58K to 58M ). This mesh is not additional to that required by Rule 6.
[0469] Rule 10 If the distance between two openings is 1.2 m or less than two MVCJ's between the openings may be replaced by one centrally located VMCJ.
[0470] In respect of FIGS. 58E to 58M the following is the key:
[0000]
L = width of MCL ®
H = average Panel
MCL ® Fibre Mesh in
Stucco Rite ® Wall
Height
base coat extending
Panel
Σb = Sum of Opening
300 mm above and
Σh = sum of Opening
Widths
below opening
Heights
b 1 b 2 = opening widths
h 1 h 2 = opening heights
[0471] In FIGS. 58 N to 58 KK are shown examples for MCJ and mesh location on single level buildings. In these drawings the key is as follows:
[0000]
L = Width of MCL ®
R = Rise of Gable
MCL ® Fibre Glass
Stucco Rite ® Wall
B = Opening width −
Mesh in base coat
Panel
Single Level
extending 300 mm
H = Average Panel
Σb = Sum of Opening
above and below
Height
width
opening
H′ = Lower Panel
b′ = Opening width −
* = CMCJ's required
Height
lower level
by Rules 2 or 8 and
H″ = Upper Panel
b″ = opening width −
placed at min
Height
Upper Level
separation distance
h = opening heights −
He - Eaves Height
i.e. 175 mm
single level
VMCJ or HMCJ -------
* = CMCJ's required
Σh = Sum of
Floor/Wall Junction
by Rules 2 or 8 and
Opening Heights
—
placed at max
h′ = Opening Height −
separation distance
Lower Level
i.e. 300 mm
h″ = Opening Height −
Upper Level
[0472] In FIGS. 58 LL to 58 MM are shown examples for MCJ and mesh location on two level buildings. In these drawings the key is as follows:
[0000]
L = Width of MCL ®
R = Rise of Gable
MCL ® Fibre Glass
Stucco Rite ® Wall
B = Opening width −
Mesh in base coat
Panel
Single Level
extending 300 mm
H = Average Panel
Σb = Sum of Opening
above and below
Height
width
opening
H′ = Lower Panel
b′ = Opening width −
* = CMCJ's required
Height
lower level
by Rules 2 or 8 and
H″ = Upper Panel
b″ = opening width −
placed at min
Height
Upper Level
separation distance
h = opening heights −
He - Eaves Height
i.e. 175 mm
single level
VMCJ or HMCJ -------
* = CMCJ's required
Σh = Sum of
Floor/Wall Junction
by Rules 2 or 8 and
Opening Heights
—
placed at max
h′ = Opening Height −
separation distance
Lower Level
i.e. 300 mm
h″ = Opening Height −
Upper Level
[0473] The present invention has been described by reference to the drawings and requirements that might satisfy New Zealand regulatory approvals. Whilst the description is in respect of a wooden framed structure having a cavity depth of about 35 mm clad by a reinforced and weather sealed plaster matrix of about 21 mm thick, variations that might satisfy requirements in other countries are within the scope of the present invention. Reference is drawn to our website www.mineral.co.nz/stuccorite.cfm which discloses details of the existing MCL StuccoRite cavity wall cladding system described in our Technical Manual dated January 2006.
[0000] Some features of note in the new system include:
Stucco Panel
[0000]
Pumped in mortar to mark face
Bagged dry-mix—consistent high quality mix design and consistency
Lower water/cement to achieve lower shrinkage
Fibreglass mesh standard in top coat
Square of fibreglass mesh diagonal in top coat across corners of openings
Additional fibreglass mesh in base coat of narrower stucco panels located between larger stucco panels
Max panel size 8 m×5.2 m
Mesh
[0000]
K-Lath mesh is stapled to batten, not timber framing
Mesh can span up to 460 mm 16 g wire to 300 mm system or up to 640 mm with 149 g wire.
Built in plastering paper
Built in backing bituminous paper
Supplied and fixed as sheet with overlap of mesh and bituminous paper on two edges
Batten
[0000]
Vertical timber batten is structural size and enhances strength and strength of wall
Batten placement at 300 mm spacings fixed not only to stud face but can span up to 1.2 m between dwang to plates
Battens can span over floor/walls junction
HMCJ
[0000]
Spaced up to 5 m centres (instead of 2.4 m)
Special PVC z-flashing
Special PVC z-flashing splice and corner jointers
If z-flashing not nailed to batten then is replaceable due to taper at back of vertical batten
Can be located at
floor/wall junction window head any locations on timber framed wall
[0497] VMCJ
Spaced up to 8 m apart instead of 4 m Not located at side of openings Can be located as close as 175 mm to side of openings or corners No VMCJ at top corner of openings No VMCJ at bottom corner of openings Shrinkage absorbed by rolling/deflection of the batten
Special uPVC Profiles
Special pvc moulding for base of stucco wall panel incorporating batten, insert, drip edge Special pvc moulding for window head and VMCJ Special pvc moulding for window/door side jamb—two piece Special pvc moulding for soffit, sill and edge Special pvc moulding for VMCJ Fully waterproof moulding Accepts shrinkage or expansion Does not require double studs at VMCJ Does not even require any stud at VMCJ
[0513] Compliance with the Rules as set out we believe will enable compliance with both building code NZS3604 and plaster code NZS4251. | A building which has as a wall of its envelope, a wall of a size of at least 2.4 m high, and at least 4 m wide; wherein the wall has a frame or a substructure having studs at least some of which are spaced by a modular distance, battens supported from and fixed to said frame or substructure, such battens fixed both on and between studs, a first mesh (“inner mesh”) attached to such battens, a second (“outer”) mesh supported at least in part by a plaster matrix, and the plaster matrix applied as more than one layer, the plaster matrix penetrating the first mesh, interposing both meshes, attaching to the second mesh and covering the second mesh; wherein the wall has at least one opening selected from a group consisting of door and window openings; and wherein at least part of the periphery of each opening, within the matrix, has been further reinforced by one or more of (a) one or more of at least one mesh and/or lattice-work at each corner, (b) one or more of at least one mesh and/or lattice-work at each vertical side, and/or one or more mesh between adjacent openings. | big_patent |
BACKGROUND OF THE INVENTION
The background of the invention will be discussed in two parts:
1. Field of the Invention
This invention relates to the field of safes adapted to contain valuable papers and articles.
2. Description of the Prior Art
There are numerous prior art wall and floor safes adapted to be embedded in concrete, etc. or adapted to be free-standing. The variations, and complexities in such safe structures have a direct impact on the cost of construction, and ultimately, the cost of such safes. Many of such safes are intended for residential use, and may be installed in a wall or in a floor of the residence, and, in the latter instance such safes are normally embedded in concrete.
One such early structure is shown and described in U.S. Pat. No. 67,045 issued July 23, 1867, to Hall for a "Burglar-Proof Safe" in which a stepped laminated door structure fits within a correspondingly formed door opening.
Another such structure is shown and described in U.S. Pat. No. 3,481,288, entitled "Wall Safe", issued to Teleky on Dec. 2, 1969, the safe including a permanently installed container with lateral vertically arranged recesses configured for receiving a separate door portion by lateral insertion into the recesses.
U.S. Pat. No. 3,715,998, is directed to another such safe structure, and is entitled "Wall Safe", such patent being issued to Teleky on Feb. 13, 1973, the structure having a door which is substantially rectangular and when it is in the closed position the margins of the door substantially throughout their entire length are overlapped by recesses along the margins of the opening that is closed by the door.
U.S. Pat. No. 4,070,074, entitled "TamperProof Cabinet", issued to Rohme, on Jan. 24, 1978, such patent disclosing cabinet having a door which is required to be unlatched by an initial unlatching sliding movement and then the usual pivotal traverse from its closed into its open position.
Another safe structure is shown and described in U.S. Pat. No. 4,176,440, issued to Robert J. Lichter, the applicant herein, on Dec. 4, 1979, such patent being entitled "Safe, and Method and Apparatus for Building It", the safe being a "do it yourself" safe having a liner with various grooves or slots adapted to receive the inner edge portions of steel bars of predetermined size, a bottom, a firecap mold, and a strong steel door with associated lock. The parts are assembled in an appropriate location within the residence, and then the concrete is poured, and the balance of the parts attached.
A building door is shown in U.S. Pat. No. 4,294,040, entitled "Safety Door for Buildings and Rooms", issued Jan. 8, 1957, to Crotti, the patent disclosing a safety door structure which is transveresly sliding with one part thereof serving as a supporting column equipped with hinges and the other serving as a door panel rotatably supported by the hinges, the supporting column disappearing from view during the opening stage with the opposite side of the door, including the lock, disappearing from view upon closing with the lock accessible through an access opening.
U.S. Pat. No. 4,136, 792, was issued to Wilson, on Jan. 30, 1979, and is entitled "Quick Attachment Device for a Lifting Tractor", this patent being included to illustrate closure release mechanisms, and discloses an implement, such as a bucket, for attachment to and removal from, a highlift or tractor.
It is an object of the present invention to provide a new and improved safe and door structure.
It is another object of the present invention to provide a new and improved readily assembled, low cost door and safe structure.
SUMMARY OF THE INVENTION
The foregoing and other objects are accomplished by providing a safe having a valuables receiving chamber with a generally rectangular opening with a first set of inwardly extending ledges on opposing walls for placement of a plateshaped separate steel door thereon, and a set of grooves formed on the opposite walls transverse to the first set of opposing walls providing stops for retaining the door therein, the width of the grooves being a distance slightly more than the thickness of the door, with one groove having a depth substantially greater than the other, with one edge of the door being inserted on a slight angle into the deeper groove while the other edge is pivoted toward the ledge, the door then being laterally displaced until the latter edge is in abutment with the seat of the shallower groove. A lock assembly on the reverse side of the door has the latch bolt engaging a detent in one bar for prevention of lateral movement with reinforcing bolts on both sides of the lock bolt preventing transmission of force to the lock mechanism in the event of forceful intrusion attempts. In one embodiment, the grooves are formed by elongate bar members, while in another embodiment, the grooves are formed within the walls themselves.
Other objects, features and advantages of the invention will become apparent from a reading of the specification, when taken in conjunction with the drawings, in which like reference numerals refer to like elements in the several views.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded perspective view of the components of the safe apparatus in accordance with the present invention;
FIG. 2 is a side elevational view, partially in cross-section and partially broken away of the safe apparatus of FIG. 1 illustrating the door engagement;
FIG. 3 is a bottom plan view of the apparatus of FIG. 2, as viewed generally along line 2--2 thereof;
FIG. 4 is a side elevational view of a portion of the structure of FIG. 2, partially in cross-section, as viewed generally along line 4-4 thereof;
FIG. 5 is a perspective view of an alternate embodiment of the safe apparatus according to the invention;
FIG. 6 is a side elevational view of the embodiment of FIG. 5, partially broken away and partially in cross-section, illustrating the door engagement therewith; and
FIG. 7 is a cross-sectional view of the apparatus of FIG. 6 as viewed generally along line 7--7 thereof.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The safe construction to be hereinafter described is a floor safe and may be formed utilizing the construction heretofore described in applicant's U.S. Pat. No. 4,176,440, which is herein hereby incorporated by reference. The construction in such patent is an in place construction wherein a liner, preferably formed of an appropriate plastic material, is employed as a combination liner and form for the pouring of concrete thereabout to provide the majority of the body of the floor safe.
Referring now to the drawings, and particularly to FIG. 1, there is shown in exploded perspective view a safe, generally designated 10, having a somewhat elongate generally rectangular (in plan view) liner 12 forming a valuables chamber 14. The liner 12 is formed of a first set of opposing side walls 16 and 18, and an interconnecting set of mutually perpendicular opposing end walls 20 and 22. The corners thereof are suitably reinforced as with corner brackets 23-26, which may be integrally formed with the side walls or may be angle iron or the like, depending on the method of fabrication of the liner 12. Such a liner may be made for example by injection molded plastics techniques, or may be fabricated from sheet metal or sheet steel of sufficient thickness suitably connected such as by welding. Liner 12 may also be formed of a thermosetting resin or other fire-resistant and heat insulating substance. By reference also to FIG. 2, in accordance with the teachings of applicant's above-mentioned U.S. Pat. No. 4,176,440, after assembly and pouring, the concrete 11 and reinforcing bars or rebars 13 surround the liner 12 and other parts of the safe. It is also to be understood that the invention described herein is equally applicable to a safe which is formed of all metal, such as by steel fabrication or steel casting methods, and as such the invention is not intended to be limited to a cast in place concrete construction.
The upper edges of the walls 16, 18, 20 and 22 define a common plane. Spaced downwardly from this common plane, and extending inwardly from the side walls 16 and 18 are integrally formed laterally extending grooves 28 and 30, both of which are at a predetermined distance from, and parallel to, the upper edges of the container opening 14. Similarly, the end walls 20 and 22 have integrally formed therein opposing laterally extending grooves 32 and 34, each being at the same distance from, and generally parallel to, the upper edges of the walls 20 and 22, but spaced closer thereto than the grooves 28 and 30. The distance between the lower edge of the grooves 32 and 34 and the upper edges of the grooves 28 and 30 form door receiving grooves of a width slightly greater than the thickness of the coacting edges of the door, generally designated 40.
The grooves 32 and 34 on the end walls 20 and 22 are configured and dimensioned for receiving therein the edges of bar members 42 and 44, respectively, such bar members preferably being formed of a steel composition, such as case-hardened steel. Similarly, the grooves 28 and 30 in the side walls 16 and 18 are configured and dimensioned for receiving therein the edges of bar members 46 and 48, respectively, such bars, likewise being formed of suitable steel material, and having a generally rectangular cross-sectional configuration. To facilitate assembly, the grooves 28, 30, 32 and 34 are formed to enable them to receive the bars therein in a relatively light press fit relationship, such that after placement of the corresponding bar therein, there will be no danger of slippage.
The bar members 42 and 44 are generally identically configured and are of a generally rectangular elongate configuration, having a length greater than the corresponding dimension of the grooves 32 and 34, respectively, that is, each bar member 42 and 44 is longer than the width of the end walls 20 and 22. Similarly, the bar members 46 and 48 have a length greater than the width of the side walls 16 and 18, respectively.
The dimensions and configurations of the bar members 42, 44, 46 and 48 enable coupling of the bar members together in spaced relation upon assembly, after insertion into the grooves 28, 30, 32 and 34. For this purpose bar members 46 and 48 have formed in the leading edges thereof, cutouts 46a, 46b, 48a and 48b, respectively, for receiving therein bolt members 42a, 44a, 42b, and 44b, respectively, depending from the bar members 42 and 44, respectively. As shown in FIG. 2, the bolt members may be attached by drilling and tapping holes in the upper bar members 42 and 44, and threadably engaging these holes with the bolt members 42a, 42b, 44a and 44b, with final tightening accomplished upon assembly. With the respective bar members in the respective grooves, the bolt members engage the cutouts (See FIG. 2). For example, bolt member 42b of bar member 42 engages cutout 48a of bar member 48, while bolt member 44b engages cutout 48b. Similarly, bolt member 42a of bar member 42 engages cutout 46a of bar member 46, while bolt member 44a of bar member 44 engages cutout 46b of bar member 46 (See FIG. 2). This engagement retains the bar members in spaced generally parallel relation after assembly.
As shown in FIGS. 1 and 3, the groove 30 and the bar member 48 are provided with coacting indentations which form a lockbolt receiving notch 50 disposed generally centrally relative to the width of the sidewall 18. The door 40 is formed of a generally rectangular steel plate member 52 having a lower edge 53 thereof rounded for reasons which will be hereafter discussed. Located relatively centrally on, and extending therough the plate member 52 is a lockset 54, which includes a combination dial 55 accessible from the exterior of the door 40. The lockset 54 is secured to the bottom or interior of plate member 52 such as by bolts and includes a slidable lockbolt 56, which is movable from a position within the housing of the lockset 54 to an extended position, shown in FIG. 3 into engagement with the notch 50. Lockbolt reinforcing means are provided, such means including safety bolts 58 and 59 secured to the undersurface of the plate member 52 in generally perpendicular relation thereto, such bolts 58, 59 being positioned in spaced relation on either side of the lockbolt 56. The purpose of these bolts is to reinforce the door assembly 40 against lateral movement in the event an intruder attempts to pry the door laterally as viewed in FIG. 3. As shown in FIG. 1, the door 40 preferably includes a pair of handles 60, 61 secured to the exterior of the plate member 52 for facilitating lifting and removal of the door 40. The handles 60 and 61 are secured with fasteners in such a way that excessive force, such as by applying a lever to force the door 40 will result in breakage of the fasteners.
Referring now to FIGS. 2 through 4, the relationship of the bar members 42, 44, 46, and 48 to the door 40 will be described. The door 40 is dimensioned for being received in and completely removed from the open upper end of the chamber 14. For this purpose, the plate member 52 is generally rectangularly configured, or square, in plan elevation with the width thereof closely approximating the width of the chamber 14.
The length of the plate member 52 of the door 40 is dimensioned to provide clearance while inserting at an angle as shown in dotted lines in FIG. 2, with the rounded lower edge 53 positioned in the groove formed beneath the intruding inner edge of groove 34 which is reinforced with bar member 42. It is to be emphasized that the inner edge of groove 34 intrudes into the chamber 14 a distance substantially greater than that of the intrusion of the inner edge of groove, 32, with the length of the plate member 52 being equal to the distance between these inner edges plus the intruding length of the inner edge of groove 34, with a slight variance allowing for tolerances. The distance of intrusion of groove 34 may be one and one-half times, and preferably twice the distance of intrusion of groove 32. When discussing the operation of the door 40 herein, it is to be understood that reference to the bar members includes the corresponding groove in which the bar member is positioned, with the bar members being the primary structural components for attachment of the door 40.
In this manner for closing the safe 10, the door 40 is positioned at the angle as shown in FIG. 2 with the rounded lower edge of plate member 52 resting on the lengthwise extending bar members 46 and 48. A slight force is exerted laterally until this first edge is abutting against the sidewall 22 during which time the door 40 is being lowered along the opposite edge until this opposite edge clears the upper corner of the inner edge of groove 32. Thereafter the door 40 is permitted to drop until totally supported by the longitudinally extending ledges formed by bar members 46 and 48. The door 40 is then shifted laterally in the opposite direction into the groove 32 formed between bar 42 and lower stop ledge bar members 46 and 48, until the opposite edge of plate member 52 is seated in the groove in abutting relation with the opposite sidewall 20, as shown in solid lines in FIGS. 2 and 3, the sidewall 20 being the bottom or the seat of the door receiving groove so-formed. At this position, the lockbolt 56 is in alignment with the notch 50 and the combination 55 may be spun to lock the door 40 between the bar members 42 and 44.
With this configuration of the plate member 52 relative to the upper retaining bar members 42 and 44, along with the notch 50 and the safety bolts 58 and 59, an efficient, yet simple arrangement is provided for secure locking. In the event an intruder attempts to pry the door 40 by placing a pry bar between the inner edges of either groove 32 or 34, the side forces exerted will place the lockbolt 56 in shear relative to the notch 50. The safety bolts 58 and 59 disposed in proximate relation to the inner edge of bar member 48 assures that these force are localized and concentrated on the lockbolt 56 only, and are not transmitted to the locking mechanism of the lockset 54, thus protecting the lockset 54 from damage by prying.
FIGS. 5 through 7 depict a modified liner 70 which is more economical in that a number of bar members are eliminated with structural integrity being accomplished by means of the concrete 72 and judicious placement of rebars 73. The door 40 is identical to that previously described. However, the liner 70 is formed with a lower portion 74 defined by sidewalls 75 and 76, and end walls 77 and 78, and an upper portion 80 being defined by sidewalls 81 and 82 and end walls 83 and 84, the lower portion 74 being the rectangularly configured valuables receiving chamber of smaller cross-section to define a peripheral door receiving ledge 88, with this ledge 88 being the dividing line between the lower and upper portions 74 and 76, respectively. The door 40,as shown in FIGS. 6 and 7 rests on this ledge 88.
Immediately above this ledge laterally opposing grooves 90 and 92 are formed for receiving the opposite ends of the plate member 52 of the door 40 (See FIG. 6). The grooves 90 and 92 of this embodiment are the equivalent of the door receiving groove means formed in the preceding embodiment between bar members and, as in the preceding embodiment, the grooves are dimensioned so that the depth of one groove 92 is substantially greater than the depth of groove 90, as stated above.
The exterior of the liner 70 is provided on the end walls 83 and 84 of the upper portion 80 with outwardly extending flanges or fins 93 and 94 on end wall 83 and fins 95 and 96 on end wall 84. Each of the fins extends generally perpendicular to the corresponding end wall a distance sufficient to cooperate with a rebar 73 postioned thereon prior to pouring of the concrete (See FIG. 6). In additon rebars 73 are positioned on the exterior of the end wall grooves 90 and 92. The rebars 73 and concrete 72 provide structural integrity for the liner 70.
However, to assure integrity in the locking arrangement, a lock notch 100 is formed in the sidewall 75 of the lower portion 74 of the liner 70 and a longitudinal fin 94 is formed on the exterior of sidewall 75 in alignment with the lower edge of notch 100. An elongate bar member 99 having a notch for mating with the lock notch 100 is positioned on this fin 94 to provide shear strength at the locking location, that is where lockbolt 56 engages notch 100.
Insertion and removal of door 40 is accomplished in the same manner as that previously described, with the door 40, in its locked position being depicted in FIGS. 6 and 7. In this embodiment, the liner 70 is lowered into position within a hole in the ground and then leveled. The bar member 99 is positioned on fin 94, and the rebars 73 are positioned in resting relation on each of the fins 93-96,as well as on the exterior of the ledge formed by grooves 90 and 92. The rebar 73 and bar member 99 are suitably secured, such as by wire, to prevent movement during pouring of the concrete 72. After curing of the concrete, the concrete 72, the bar member 99 and the rebar 73 provide the required strength for the safe construction, while the grove and notch arrangement along with the safety bolts 58 and 59 protect the lock mechanism 54 from damage in the event one attempts to pry the door 40. With the lockbolt 56 operable in a direction transverse to the direction of insertion of the door, the strength of the safe is greatly increased to protect against shear.
In accordance with the safe construction hereinabove described, there is a simple, yet effective door and safe construction, which may be equally applicable to a basic steel safe preassembled at the factory. While there has been shown and described a preferred embodiment, it is to be understood that various other adaptations and modifications may be made within the spirit and scope of the invention. For example, although the door is depicted as being formed of a plate member 52 of generally uniform thickness, it is only necessary that the groove contacting edges be of a thickness consisitent for being received within the appropriate groove. Furthermore, the lower ledges supporting the door 40 need not be continuous surfaces, but may be, for example, pins or rods projecting into the opening. In addition, the safety bolts 58 and 59 may be replaced by steel blocks or the like in close relation to the lockbolt 56 for performing the same function. Furthermore, although the safety bolts 58 and 59 provide a margin of protection, such parts may be eliminated since, in any event, the lockbolt 56 is formed of a high strength steel material which has much greater strength in shear than in compression. A firecap such as shown in applicant's above-mentioned patent may likewise be affixed to the upper open end of the safe structure herein. Furthermore, it is to be understood that the term rectangular, equally includes a square configuration of the door plate member 52. Other such variations will be readily apparent to those skilled in the art, and it is intended that the invention be limited only to the scope of the appended claims. | A safe having a valuables chamber with an access opening with inwardly extending ledges for placement of a plate-shaped separate steel door thereon, and a set of grooves formed on opposing walls retaining the door therein, the width of the grooves being a distance slightly more than the thickness of the door, with one groove being substantially greater than the depth of the other, with one edge of the door being inserted on a slight angle into the deeper groove while the other edge is pivoted toward the ledge, the door then being laterally displaced until the latter edge is in abutment with the seat of the shallower groove. A lock assembly on the reverse side of the door has the latch bolt engaging a detent in a metal bar for prevention of lateral movement with reinforcing bolts adjacent the lock bolt preventing force on the lock mechanism in the event of forceful intrusion attempts. In one embodiment, the grooves are formed by elongate bar members, while in another embodiment, the grooves are formed within the walls themselves. | big_patent |
RELATED PATENT APPLICATION
This international PCT patent application claims priority to Australian provisional patent application filed 11 Oct. 2011, and accorded application number 2011904211. The disclosure of the Australian provisional patent application is incorporated herein by reference.
TECHNICAL FIELD OF THE INVENTION
The present invention relates in general to the monitoring and measuring of fluid pressures in geological formations, and more particularly to measuring techniques which more accurately measure the fluid pressure in the formation at a desired elevation or depth, without being influenced by pressures in the formation above and below the pressure measuring apparatus.
BACKGROUND OF THE INVENTION
The measurement of pressures in geological formations is often of great importance to engineering and environmental matters. To the civil engineer, pore pressures in soils are important in the design of foundations, slopes and retaining walls. To the hydro-geologist, pressures in aquifers and aquicludes are a key to determining groundwater resources and movement. To the petroleum engineer, understanding the pressure of the fluids is critical in determining the resources and reserves of petroleum fluids.
The civil engineering industry often refers to pressure monitoring systems as piezometers. Piezometers take a variety of forms. The most traditional piezometer involves the placement of an open tube standpipe into a borehole with a sand or gravel pack around a slotted tip. A bentonite seal is placed above the gravel pack and the remainder of the hole is cemented. Variations on this theme exist with some standpipes being fitted with a filter tip, where the filter tip is driven into a clay.
The fluid level is generally measured in standpipe piezometers by measuring the water level therein either manually by some form of dipping system, or by the measurement of pressure above a certain point in the standpipe. This has previously been accomplished by measuring the required pressure to force a bubble out of a tube in the standpipe, but is more commonly undertaken by the use of pressure transducers.
The disadvantage of the standpipe system is that the standpipe has a significant volume. To produce a change in the volume of the fluid in the standpipe, fluid must either come out of the formation to fill the standpipe, or pass from the standpipe into the formation. This requires the formation to have an adequate permeability and storage characteristic to operate with the standpipe. This pressure measuring technique also requires a very good connection between the standpipe and the formation. In all cases, the standpipe adversely functions to dampen the true pressures of the formation.
To overcome the volumetric problems with the use of standpipes, low volume pressure transducers were fixed in a filter zone in a borehole or structure. Because of the inherent instability of early electronic devices, pneumatic piezometers were developed. In the use of pneumatic piezometers, two tubes were fitted to the transducer—one to permit the passage of compressed air to the device, and the other to permit the return of the compressed air after it passed through a pneumatic valve. The pressure of the fluid in the formation was detected by the pressure required to pneumatically open the valve, as detected by the airflow up the return tube. This type of transducer was particularly well suited to the monitoring of earth dams as the tubing and transducers could be easily incorporated into the earth structure.
The next major development was to use electrical transducers, particularly of a vibrating wire type. This type of transducer exhibited better long term drift characteristics as compared to the bridge type transducers of the same era. The vibrating wire transducers had very low volumetric requirements to operate an internal diaphragm, and as such were easily incorporated into filter zones within boreholes. The availability of vibrating wire transducers made it possible to install multiple transducers into a single borehole, although this was generally accomplished by the use of multiple levels of gravel packing and cementing.
The next major development was the realisation that in many cases a pressure transducer could be cemented directly into a borehole. To make this possible, the pressure sensing diaphragm of the transducer must be isolated from the direct contact with the cement, and the cement required adequate permeability to permit a fluid connection between the geological formation and the transducer. With this installation method, there is always an uncertainty as to what is connected to what, i.e. is the formation fluid at the same elevation as the transducer in the borehole, or is the fluid in the formation at some other level in the borehole? It has been generally assumed that the pressure measured by the transducer is that of the formation fluid located directly adjacent to where the transducer has been installed. This may not, however, be universally correct as, if the formation adjacent to the transducer is extremely impermeable, and the formation further up the hole is not, then depending on the relative permeabilities of the formations and the cement grout, the pressure measured may not be that produced by the formation located directly adjacent to the pressure transducer. This becomes particularly problematic if shrinkage of the cement grout occurs, which leads to longitudinal leakage paths within the cured grout. When this occurs, the pressure transducer can be influenced by formation pressures that exist above and below the pressure transducer. In this event, the pressure transducer measures the composite of all of the formation pressures to which it is exposed.
Because most exploitable aquifers have high permeability and storage characteristics, the groundwater industry has generally managed to utilise traditional standpipes or the use of monitoring wells. In low permeability formations, investigations have been undertaken to consider low volume fluid pressure measuring techniques.
The petroleum industry is a field where the measurement of geological formation pressures was traditionally accomplished by pressure measurements in test wells or production wells. This situation has since changed dramatically with the introduction of several formation testing tools. Permanent monitoring of formation pressures has also grown with the use of pressure transducers which are fixed in the casing, or to the tubing, having been run into a well and cement grouted into place.
Lastly, it has been proposed that one or more pressure sensing lines could be grouted in the borehole formed in a coal seam to measure the fluid pressures therein. This technique is disclosed in a technical paper published in SPE Reservoir Engineering (February 1987) and entitled ‘Reservoir Engineering in Coal Seams: Part 2—Observations of Gas Movement in Coal Seams’ by Ian Gray. According to this technique, the pressure sensing line(s) is strapped to a PVC conduit and the assembly is lowered into the borehole. The borehole is grouted around the assembly, and the line is filled with water to prevent the grout from flowing up the pressure sensing line. The PVC pipe can accommodate the flow of grout therein. After the grout has set, the pressure sensing line is pressurised to fracture the grout and create an opening to the coal seam. The pressure sensing line can be connected to a pressure gauge or chart recorder located at the surface.
From the foregoing, it can be seen that a need exists for a fluid measuring technique that more accurately measures the fluid pressure in the part of the formation that is at the same depth, elevation or vicinity of the pressure sensor. A further need exists for isolating the pressure sensor in a borehole so that it is only exposed to the fluid pressure in the formation adjacent to the pressure sensor and not to the formation pressure at another position in the hole. A further need exists for a method to isolate the pressure sensor in the borehole using a cement grout between the pressure sensor and the borehole, and then opening a communication path in the cement grout between the pressure sensor and the wall of the borehole where the formation fluid pressure is to be measured. Yet another need exists to undertake the installation of one or more sensors in a single cementing operation.
SUMMARY OF THE INVENTION
The various features of the invention permit a more reliable connection system between a pressure sensing location within a cement grouted borehole and the transducer system used to monitor the pressure in the surrounding geological formation. This is accomplished by cementing a conduit fitted with a filter at its bottom end in the borehole at a desired location. The filter is the inlet to the pressure measuring apparatus. The conduit is pressurised with fluid to clear the conduit of any cement grout during this operation. A valve is used to block the backflow of cement grout from the borehole back into the conduit. The valve is preferably a check valve.
Once the cementing operation is complete, but before the cement grout has completely set, a fluid is again introduced into the conduit. The fluid is forced out of the bottom end of the conduit (and the filter) and displaces the cement grout to achieve a fluid connection between the formation and the filter. The process of introducing the fluid into the conduit is preferably accomplished in several stages. The first stage of the initial fluid injection is to ensure the filter end of the conduit is cleaned of cement grout. The second stage of fluid injection takes place to move the cement grout in the borehole from around the bottom end of the conduit. The second stage is normally carried out when the cement grout has started to set. The final fluid injection stage can be advantageously employed to ensure connectivity in certain circumstances, and follows the full setting of the cement grout. In this final stage, a fluid is pumped through the conduit and filter at adequate pressure to cause the local hydrofracture of the geological formation located laterally adjacent to the filter. As such, pressures produced by the geological formation at the filter depth are coupled directly to the input of the pressure measuring apparatus.
In an alternative process, the fracturing of both the grout and the formation can be accomplished following the filter washing and setting of the grout.
According to a feature of the invention, the cement grout is pumped through the borehole formed in the formation using either a grout pipe to convey the grout from the base upwards in the borehole, or if grouting is being undertaken from a borehole collar, a return tube is employed.
In one embodiment of the invention suitable for any reservoir type, a pressure transducer is installed at a desired depth in a bore to measure formation pressures at such depth. The pressure transducer is placed between a filter and a check valve equipped with a pressure relief valve. The check valve is of the type that opens at a predetermined pressure. The opening pressure of the check valve is designed to prevent a standing fluid level in the fluid monitoring zone. The installation involves the lowering of the pressure transducer into the formation on the end of a cable, together with a conduit that is typically a small diameter tubing pipe (typically ¼′ diameter). Cement grouting of the borehole is undertaken along with the staged process of fluid injection in the conduit to clear the filter of grout and then displace the grout so that the filter is in communication with the formation pressure to be measured. In certain circumstances the method can be followed by a hydrofracture process once the grout has set.
In another embodiment of the invention the conduit run into the borehole can be constructed with a small diameter tubing pipe connected to a larger diameter tubing section located near the surface. The installation of the tubing pipe would normally, but not necessarily, be strapped to a grout pipe. When located at a desired depth in the borehole, the top of the tubing pipe is filled with fluid and fitted with a non-return valve. The non-return valve may be automatically or manually operated to achieve a no-return behaviour. The grouting operation for the borehole is then undertaken, whereupon the non-return valve prevents fluid from being pushed out of the conduit due to density or pumping pressure difference. Once grouting is complete, a small volume of fluid is pumped through the conduit to clean the filter. This is followed by the pumping of additional fluid into the conduit to displace the grout in the borehole radially around the inlet filter, usually when the grout has started to set, to avoid mixing the fluid and the grout. In some cases the method can be followed by a hydrofracture process once the grout has set. In this embodiment, fracturing pressures are not impeded by the pressure limitations of the downhole transducer used in the embodiment described above. Once the grout has set, the non-return valve is removed and the pressure sensing transducer is run into the top of the conduit. It is undesirable to permit fluid movement within the conduit as this requires the formation to supply or receive that fluid. To avoid this and to permit the pressure transducer to be located in its most suitable pressure range, the pressure transducer is preferably attached to a packer which is lowered with it into the enlarged upper portion of the conduit. The packer may then be set to block the upper end of the conduit. In this embodiment, the transducer can be removed periodically for calibration or maintenance. It is also possible to alter the location of the transducer within the conduit to suit the pressure range of the device. This embodiment is ideally suited to high accuracy monitoring of groundwater where the fluid in the conduit is a liquid (preferably water) of known density. Preferably the density of the fluid should match that of the reservoir located in the geological formation.
According to a further embodiment of the invention, disclosed is a method of monitoring a fluid pressure in a subterranean formation. The method includes forming a borehole in the subterranean formation at least to a depth where the fluid pressure is to be measured, and then placing a conduit into the borehole to a depth so that a bottom inlet end of the conduit is laterally adjacent a location where the formation pressure is to be measured. A non-return valve is used in the conduit so that liquid cannot pass upwardly all the way through the conduit. A cementitious material is placed in the borehole until the cementitious material rises at least above the bottom inlet end of the conduit. A liquid is pumped down the conduit through the non-return valve, out of the inlet end of the conduit and into the cementitious material in the borehole to displace the cementitious material around the bottom inlet end of the conduit to thereby form a fluid connection to the formation. A pressure sensing device is coupled to the formation fluid pressure within the conduit to measure the fluid pressure of the formation at the desired depth.
According to yet another embodiment of the invention, disclosed is a method of monitoring a fluid pressure in a subterranean formation, which includes forming a borehole in the subterranean formation at least to a depth where the fluid pressure is to be measured. A pressure sensing device is connected to a bottom inlet end of a conduit so that the pressure sensing device measures fluid pressures at the inlet end of the conduit, and the conduit is lowered into the borehole until the inlet end of the conduit is at a depth where the formation pressure is to be measured. The borehole is then filled with a cementitious material to a level substantially above the inlet end of the conduit and the cementitious material is prevented from flowing up the conduit, whereby the cementitious material surrounds the inlet end of the conduit. The inlet end of the conduit is purged of cementitious material by pumping a liquid down the conduit. A lateral fluid path is formed between the inlet end of the conduit and the formation, whereby the formation pressure forces the formation fluid to flow through the fluid path and through the inlet end of the conduit to the pressure sensing device so that the formation fluid pressure is measured.
According to yet a further embodiment of the invention, disclosed is a method of monitoring a fluid pressure in a subterranean formation, which includes placing a conduit in a borehole formed in the subterranean formation so that a pressure measuring inlet of the conduit is located at a depth where the formation pressure is to be measured. A pressure sensing device is connected to the conduit to measure pressures at the pressure measuring inlet of the conduit. The borehole is filled with a cementitious material above and below the pressure measuring inlet of the conduit so that the pressure measuring inlet has a fluid communication path outwardly to the formation, but the pressure measuring inlet of the conduit is isolated by the cementitious material from other portions of the formation located above and below the pressure measuring inlet of the conduit.
BRIEF DESCRIPTION OF THE DRAWINGS
Further features and advantages will become apparent from the following and more particular description of the preferred and other embodiments of the invention as illustrated in the accompanying drawings, in which like reference characters generally refer to the same parts, functions or elements throughout the views, and in which:
FIGS. 1A-1D illustrate the sequence of installation steps of a formation pressure sensing system according to the first embodiment, which incorporates a permanent downhole pressure transducer.
FIG. 2 is a component diagram illustrating the details of the pressure sensor arrangement, including a pressure sensor, a check valve and a filter.
FIGS. 3A-3F illustrate the sequence of installation steps of a formation pressure sensing system, including a hydrofracture stage, of the second embodiment of the invention where the transducer is readily accessible from the surface.
FIG. 4 shows graphically the chronological record of pressure for a pressure transducer such as that installed in FIGS. 1A-1D .
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1A illustrates a borehole ( 1 ) which has been drilled in the ground. Situated in the borehole ( 1 ) is a grout pipe ( 3 ) for carrying a cementitious material, such as a cement grout. Materials other than cement grout can be employed with equal effectiveness. The grout pipe ( 3 ) is constructed with a port ( 4 ) near its base to permit the cement grout to be deposited at the bottom of the borehole ( 1 ). Also located in the borehole ( 1 ) is a pressure sensor arrangement comprising a connector block ( 9 ) for internally connecting together a filter ( 10 ), a pressure transducer ( 5 ) and a check valve ( 7 ). The filter ( 10 ) can be any type of filter, and can be of sintered metal construction to prevent formation debris from clogging the input of the pressure transducer ( 5 ). The check valve ( 7 ) is preferably of the type which is preset to open at a suitable differential pressure. The pressure transducer ( 5 ) is lowered into the borehole ( 1 ) via a fluid injection pipe ( 8 ) which extends to the surface. Moreover, the pressure transducer ( 5 ) is located in the borehole ( 1 ) at a location where the corresponding formation fluid pressure is to be measured.
As noted above, the connector block ( 9 ) is internally cross ported to connect together the filter ( 10 ), the pressure transducer ( 5 ) and the check valve ( 7 ). The pressure transducer ( 5 ) is electrically connected to the surface by a cable ( 6 ) which transfers signals corresponding to the differential pressure across the transducer ( 5 ). The pressure transducer ( 5 ) can be of the conventional piezometer type for sensing the differential pressure across a movable diaphragm, and providing a corresponding electrical signal output. Other types of pressure sensors having electrical outputs can be employed with equal effectiveness. The check valve ( 7 ) is connected to the fluid injection pipe ( 8 ) which also extends to the surface.
Prior to grouting the borehole ( 1 ) via the grout pipe ( 3 ), the fluid injection tube ( 8 ) is filled with a liquid, such as water, under sufficient pressure that the fluid passes through the check valve ( 7 ), the connector block ( 9 ), out of the filter ( 10 ) and into the borehole ( 1 ). The liquid is pumped into the injection tube ( 8 ) to clear the system of any bubbles of gas and to ensure the filter ( 10 ) is clear of any blockage which may have occurred during its placement in the borehole ( 1 ).
FIG. 1B illustrates the borehole ( 1 ) during the grouting operation in which a cement grout material is pumped down the grout pipe ( 3 ). The cement grout exits the grout pipe ( 3 ) via the bottom port ( 4 ) where it fills the bottom of the borehole ( 1 ) and flows upwardly where it temporarily reaches a level at location ( 11 ). It can be appreciated that during the grout pumping operation, the pressure sensor arrangement is surrounded with the cement grout material.
FIG. 1C illustrates the borehole ( 1 ) which is filled with the cement grout material. As can be seen, the filling of the borehole ( 1 ) with the cement grout from the bottom up displaces the liquid in the borehole ( 1 ). At this time, a small amount of liquid is pumped down the injection tube ( 8 ) through the check valve ( 7 ) and filter ( 10 ) to clear the filter ( 10 ) of the grout material.
FIG. 1D illustrates the next stage of the fluid injection operation which displaces the cement grout from around the filter ( 10 ) to form a void at location ( 13 ) and to provide a fluid connection from the formation through the parted cement grout ( 13 ) and thence back through the filter ( 10 ) and connector block ( 9 ) to the pressure transducer ( 5 ). The injection liquid is prevented from passing back up the injection tube ( 8 ) by the check valve ( 7 ). This stage is preferably undertaken when the cement grout has started to set so that the addition of the injection fluid via the filter ( 10 ) does not dilute the grout. The grout material is then left undisturbed until fully set.
FIG. 2 illustrates the pressure transducer assembly which includes the connector block ( 9 ) with the pressure transducer ( 5 ) screwed therein so as to be connected to the internal porting of the connector block ( 9 ). The pressure transducer ( 5 ) is of the type where the top of the pressure sensing member is exposed to pressure which is the reference internal pressure of the transducer and is preferably a vacuum, or in shallow applications may be vented by another conduit (not shown) to atmospheric pressure. The bottom of the pressure sensing member is exposed to the fluid pressure produced by the geological formation. The electrical output of the pressure transducer ( 5 ) is connected to an electrical cable ( 6 ), which carries the electrical pressure signals to surface-located monitor equipment. The electrical signals can be carried to surface-located equipment and converted to conventional pressure readings, such as millibars, psi, etc. The pressure signals can also be transmitted via telemetry equipment to remote locations where the pressures of a number of geological formations can be monitored.
A preset pressure relief type of check valve ( 7 ) is similarly screwed into the connector block ( 9 ), as is the filter ( 10 ). The connector block ( 9 ) contains internal passages ( 20 ), ( 21 ), ( 25 ), and ( 22 ) to provide a common connection between the components connected to the block ( 9 ). The passage ( 20 ) is blocked by grub screws ( 23 ) and ( 24 ) to prevent communication of the internal passages of the connector block ( 9 ) with the borehole ( 1 ). The fluid injection pipe ( 8 ) is connected to the inlet side of the pressure relief and check valve ( 7 ). As described above, the fluid injection pipe ( 8 ) is supplied with a fluid from up hole pump equipment.
From the foregoing, described is an embodiment of a formation fluid pressure sensing system in which the pressure transducer ( 5 ) is precisely located down a borehole ( 1 ) at a location where the pressure in the geological formation is to be measured. The pressure transducer ( 5 ) together with a filter ( 10 ) is fixed in the borehole ( 1 ) at the desired location by placing a cement grout around the pressure transducer ( 5 ). Before the cement grout is fully cured, a liquid is pumped down hole through a check valve ( 7 ) to clear the filter ( 10 ) of the cement grout material. Subsequently a fluid is again pumped down the borehole ( 1 ) through the check valve ( 7 ) to form a void or communication path between the formation and the pressure transducer ( 5 ). The cement grout material around the void ( 13 ) isolates the pressure transducer ( 5 ) in the borehole ( 1 ), except the laterally adjacent portion of the geological formation where it is desired to obtain fluid pressure measurements.
FIGS. 3A-3F illustrate another embodiment of the invention. In FIG. 3A , a borehole ( 1 ) is formed in the geological formation in which it is desired to determine the fluid pressure at a particular depth. A grout pipe ( 3 ) is installed in the borehole ( 1 ) so that the borehole ( 1 ) can be filled with a cement grout material from the bottom. To that end, the grout pipe ( 3 ) is constructed with a port ( 4 ) near its base through which cement grout can be pumped into the bottom of the borehole ( 1 ). Also installed at a desired location in the borehole ( 1 ) is a filter ( 10 ) which is connected to the bottom of a fluid injection tube ( 30 ). According to this embodiment, the check valve ( 32 ) and the pressure transducer ( 5 ) (shown in FIG. 3F ) are not connected to the bottom end of the fluid injection tube ( 30 ). Near the top of the borehole ( 1 ), the injection tube ( 30 ) is connected to a larger tube ( 31 ). At the surface of the borehole ( 1 ) site, the check valve ( 32 ) and an input tube ( 33 ) are connected to the larger tube ( 31 ). A fluid is pumped through the input tube ( 33 ), which then passes through the check valve ( 32 ), the large tubing ( 31 ), the smaller fluid injection tube ( 30 ) and filter ( 10 ) before passing into the borehole ( 1 ). As shown, the pumped fluid has risen in the borehole ( 1 ) to a level ( 2 ).
FIG. 3B illustrates the next step in the method in which the cement grout is pumped down the grout pipe ( 3 ) and out of the bottom port ( 4 ) into the bottom of the borehole ( 1 ). At this time, the cement grout moves upwardly in the borehole ( 1 ) and reaches level ( 34 ). The cement grout continues to be pumped into the grout pipe ( 3 ) until the borehole ( 1 ) is filled to a desired level. The raised pressure at the filter ( 10 ) and the action of the check valve ( 32 ) prevent either the fluid or the cement grout from passing back up the tubing ( 30 ) and ( 31 ). As can be appreciated, any formation fluid initially in the borehole ( 1 ) is displaced with the cement grout material.
FIG. 3C illustrates a step in the operation in which a fluid, such as water, is pumped into the surface-located input tube ( 33 ). The fluid passes through the check valve ( 32 ) and through the fluid injection tubing ( 31 ) and ( 30 ) to clear the filter ( 10 ) of the fresh cement grout. A small diluted area of cement grout around the filter ( 10 ) is shown at location ( 12 ).
FIG. 3D illustrates the next stage, preferably when the cement grout at location ( 13 ) has started to set. This prevents dilution of the cement grout around the filter ( 10 ). According to a feature of the invention, the fluid is pumped into the surface input tube ( 33 ) so that the fluid is forced out of the filter ( 10 ), and displaces the cement grout at location ( 13 ) around the filter ( 10 ). The displaced cement grout forms a pocket, void or fluid pathway between the filter ( 10 ) and that part of the borehole ( 1 ) sidewall that is laterally adjacent to the filter ( 10 ). The filter ( 10 ) connected to the bottom end of the injection tube ( 30 ) is thus adjacent to that part of the geological formation where the fluid pressure is to be measured. Importantly, the cement grout confines the inlet to the pressure sensor arrangement to the formation pressures that exist at the desired elevation. As will be described below, the inlet to the pressure sensor arrangement is the filter ( 10 ). The filter ( 10 ) prevents cement grout particles entering the injection tube ( 30 ), and at a later stage the ingress of any particles with formation fluid. The filter ( 10 ) could be omitted in some cases. In this case the inlet to the pressure sensor arrangement would be the bottom end or inlet port of the injection tube ( 30 ). The isolation of the pressure transducer input prevents it from being influenced by borehole fluid pressures above or below the filter ( 10 ), which would otherwise occur.
FIG. 3E illustrates the operation which is carried out after the cement grout has set. In this case, a pressurised fluid is pumped into the surface input tube ( 33 ) to displace fluid from the injection tubing ( 31 ) and ( 30 ), through the check valve ( 32 ) and out of the filter ( 10 ) through the opened cement grout at location ( 13 ). The pressure of the fluid pumped into the input tube ( 33 ) is sufficient to fracture the formation at location ( 40 ) via the void area ( 13 ) around the filter ( 10 ). The hardened cement grout in the borehole ( 1 ) above and below the void area ( 13 ) functions to concentrate the pressurised fluid in the annular area of the formation surrounding the filter ( 10 ) component of the pressure sensor arrangement. Depending on the pressure and volume of the injected fluid, the fracture zone ( 40 ) of the geological formation can extend radially outwardly from the borehole ( 1 ) a significant distance. After fracturing the formation, the natural pressures of the geological formation cause the formation fluid to enter the fracture zone ( 40 ) into the void area ( 13 ), and from the filter ( 10 ) to the pressure transducer ( 5 ) described in FIG. 3F .
FIG. 3F illustrates the borehole ( 1 ) set up for monitoring the fluid pressure around the borehole ( 1 ) at fracture location ( 40 ). Here, the surface input tube ( 33 ) and check valve ( 32 ) are removed from the large injection tube ( 31 ). The large injection tube ( 31 ) remains connected to the underlying smaller tubing ( 30 ). A packer ( 34 ) carrying a pressure transducer ( 5 ) at its bottom end is inserted into the large tube ( 31 ) and sealed therein. The pressure transducer ( 5 ) is of the type where the top of the pressure sensing member is exposed to the transducer internal pressure which is preferably a vacuum, or in shallow applications to monitor an unconfined aquifer, may be advantageously connected to atmospheric pressure via a conduit (not shown), and the bottom of the pressure sensing member is exposed to the fluid pressure produced by the geological formation. The packer ( 34 ) is inflated and sealed in the large tube ( 31 ) by fluid pressure delivered through a tube ( 36 ) connected to the packer inflation tubing ( 35 ). The packer ( 34 ) effectively plugs the large tube ( 31 ) so that the pressure in the formation can pressurise the lower injection tube ( 30 ). To that end, the packer ( 34 ) functions as a seal to block the flow of formation liquid in the large tube ( 31 ). The top ( 37 ) of the packer inflation tubing ( 35 ) is sealed around the electrical cable ( 6 ) which carries the electrical signals from the pressure transducer ( 5 ). It must be realised that the pressure transducer ( 5 ) is removable and/or relocatable within the large tube ( 31 ). This provides the user with the advantage of servicing the transducer ( 5 ) or relocating it to a depth suited to its pressure range. The pressure transducer ( 5 ) is relocatable to a different depth by deflating the packer ( 34 ), and moving it together with the attached pressure transducer ( 5 ) to a different elevation in the large tube ( 31 ). When moved to the new depth, the packer ( 34 ) is again inflated to fix it in the large tube ( 31 ) in the manner described above. The packer ( 34 ) is described above as an inflatable device. In another embodiment it could be a mechanically expandable packer or a seal element which may be slid within the injection tube ( 31 ). In the latter case a vent would need to be incorporated into the device to permit fluid to pass through the seal when it is being moved. As can be seen in this embodiment, the pressure sensor arrangement includes components that are not all located in the same area, but rather are distributed in the system.
In operation, the fluid pressure produced by the geological formation enters the pressure sensing system through the formation fractures to the void zone ( 13 ) around the filter ( 10 ). Again, this occurs at an elevation in the formation where it is desired to measure the pressure. The pressure of the formation fluid rises in the injection tube ( 30 ) and exerts a corresponding force on the bottom of the pressure sensing member of the pressure transducer ( 5 ). The top of the pressure sensing member is held at a static pressure, and thus the pressure transducer is able to accurately measure the formation pressure. In some instances the transducer will be used to measure water head in a groundwater body with a phreatic surface. In this case it is advantageous to vent the top of the pressure sensing member to atmospheric pressure and the bottom to the local groundwater pressure. Changes in the formation pressure, if any, are sensed by the pressure transducer ( 5 ) and coupled by corresponding electrical signals to the surface monitoring equipment.
It should be appreciated that while reference is made in FIGS. 3A to 3F of a tube ( 30 ) being of smaller size than the upper tubing ( 31 ), this is not a necessary feature of the invention. The tubing could be of the same size provided it is large enough to take the transducer ( 5 ) and seal. The choice of tubing sizes is dependent on the local economics of the situation and the degree of variability in location that is required for the packer ( 34 ) and transducer ( 5 ) combination to monitor formation fluid pressure.
FIG. 4 shows a typical chronological record of pressure at the transducer ( 5 ) for the installation described in FIGS. 1A to 1D . Here, the borehole ( 1 ) is filled with fluid with an initial borehole hydrostatic pressure ( 51 ). With the pumping of cementitious grout up hole and past the transducer ( 5 ), the pressure increases ( 52 ) to final hydrostatic pressure ( 53 ) of the cementitious grout. As hydration takes place the fluid pressure of the cementitious grout pressure begins to decline ( 54 ). The pressure may decline to far below formation pressure before recovery ( 55 ) begins to reach formation pressure ( 56 ). This drop in pressure is more severe if the cement grout has lost fluid to the formation prior to hydration. The dotted line shows the advantageous use of fluid injection to maintain pressure at the transducer ( 5 ) to approximate formation pressure. Here, injection is conducted twice to reach peak pressures at ( 57 ) and ( 58 ) before the pressure asymptotes to the final reservoir pressure.
From the foregoing, disclosed are various embodiments of geological formation pressure sensing systems that more accurately measure the formation pressures at desired depths. The inlet to the pressure sensing apparatus is located at a desired depth in the formation, and isolated to pressures produced by the formation at such depth. As such, the measurement of the formation pressure is not affected by other and different pressures that could otherwise exist in the borehole above and below the inlet to the pressure measuring apparatus.
While the preferred and other embodiments of the invention have been disclosed with reference to specific formation pressure sensing systems, and associated methods and manufacture thereof, it is to be understood that many changes in detail may be made as a matter of engineering choices without departing from the spirit and scope of the invention, as defined by the appended claims. | A method of installing a pressure transducer in a borehole to measure the fluid prepare of a geological formation. The pressure transducer is installed into the borehole at a desired depth, and then the borehole is filled with a cement grout. The fluid connection between the pressure transducer and the formation is opened by pumping a fluid through tubing to displace the cement grout. A process of hydrofracture can be employed to provide a communication path of fluid between the formation and the pressure transducer surrounded by the fractured grout. In one embodiment of the invention, a pressure transducer is cemented into the borehole along with a check and pressure relief valve. In another embodiment, the pressure transducer is installed in the tubing at a subsequent stage. | big_patent |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a jointing structure in vehicle traveling path joints and the like having an expansion function and also to a method of mounting an elastic member therein, and is useful in applications mainly to vehicle traveling path joints in new transit systems, monorails and the like and besides, to road bed plate joints in road bridges, footbridges and the like.
2. Description of the Related Arts
One well-known urban traffic means is a new transit system which makes use of rubber tires to provide traveling on an exclusive vehicle traveling path using a motor, with power fed via a feeder line laid parallel to the traveling path.
This type of traffic means is such that a vehicle traveling path is built continuously in a belt-like form with concrete on a bridge girder and has an expansion gap in the same position as a bridge girder joint in order to absorb bridge girder expansion or contraction caused by temperature changes or the like.
With this type of traffic means, a traveling path joint is especially fitted with a rubber or steel expansion joint to prevent the occurrence of tire fallen-in, stuck-in and/or like situations so that the increased riding quality as well as the maintainability of in-traveling safety are provided.
Regarding an expansion joint applied to an expansion gap and having an elastic function with respect to the bridge girder expansion or contraction, the patent document 1, for instance, describes an expansion joint having a top-plate reinforcing material laid over the expansion gap, side-plate reinforcing materials respectively fixed to the traveling path ends, and chloroprene rubber or the like adapted to join the top-plate reinforcing material and both the side-plate reinforcing materials together.
Patent Documents on The Related Arts
[Patent document 1] Japanese Laid-open Patent Publication No. Hei.9-59904
[Patent document 2] Japanese Laid-open Patent Publication No. Hei.10-82002
[Patent document 3] Japanese Laid-open Patent Publication No. 2000-104204
[Patent document 4] Japanese Laid-open Patent Publication No. 2003-184006
However, the rubber expansion joint has encountered with such problem that it is difficult to ensure slip resistance to rubber tires and/or to pass judgement on the time for replacement because of a lack of its durability required for a tire-supporting surface.
Meanwhile, the steel expansion joint has encountered with, in addition to the problem about the slip resistance to the rubber tires, such problem that it is difficult to be given difference-in-level management by reason that a difference in level is liable to occur between the expansion joint and the traveling path, and consequently, would be considered to have a great effect on the tires and the like unless it is managed in several millimeter units.
The steel expansion joint has further involved the problem of in-traveling safety by reason that it may well be that tire punctures will occur in course of traveling due to cracks resulting from metal fatigues of mounting bolts or like components.
With both the above types of expansion joints, there has been still some fear of the tire fall-in and/or stuck-in situations occurring in cases of bridge girder portions in which a greater extent of expansion or contraction caused by temperature changes is found and/or of small-sized vehicles whose tires are small in diameter, in which case, it has been likely to lead to a reduction in riding quality.
In conventional expansion joint applications, vertical differences in level (which are such that the bridge girders are displaced in their joints on different levels) and/or lateral displacements (which are such that the bridge girders are displaced in their joints perpendicularly to a bridge girder axis) and besides, kinked joints (which are such that the bridge girders are kinked in their joints laterally) and the like when occurred in the joints of the bridge girders due to an earthquake or the like could be left as they were even after the earthquake, or could lead to the complete collapse of the bridge girders under certain circumstances. Accordingly, for the passage of emergency vehicles and the like, it has been necessary to take such emergency measures as to cover the bridge girder joints with steel sheets or the like.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a jointing structure in vehicle traveling path joints and the like having an expansion function, more specifically, a jointing structure which is adaptable for applications of various tire configurations different in tire diameter and the like, ensures high slip resistance to tires, permits less occurrence of tire fallen-in and/or stuck-in situations and is easy to be given maintenance, and also to provide a method of mounting an elastic member therein.
A jointing structure in vehicle traveling path joints and the like having an expansion function according to the present invention comprises more than one step provided face to face at the coaxially built traveling path ends with an expansion gap between, more than one elastic member respectively mounted inside the above more than one step, and a joint block mounted on the above more than one elastic member across the above expansion gap.
The present invention is to be adapted to prevent, by blocking up the expansion gap in a bridge girder joint with the joint block while permitting an expansion gap function to be maintained, the occurrence of tire fall-in and/or stuck-in situations for the achievement of smooth and safe vehicle traveling (see FIG. 2 ), and is thus useful in applications mainly to vehicle traveling path joints in new transit systems, monorails and the like, i.e., joints of vehicle traveling paths respectively built on bridge girders as an integral part thereof, and besides, to road bed plate joints in road bridges, foot bridges and the like.
According to the present invention, it will be appreciated that even in the occurrence of any displacement such as the vertical differences in level and/or the lateral displacements and besides, the kinked joints in the joints of the bridge girders especially due to the earthquake or the like, the joint block may be conditioned to be always in the center of the expansion gap thanks to elastic member deformation for the elimination and/or relief of the differences in level and/or the lateral displacements and the like, resulting in the achievement of smooth vehicle traveling without the need for any emergency measures involving the use of the steel sheets or the like.
It will be appreciated also that the joint block is placed across the expansion gap, and thus, the adequate management of accuracy of each member if given may be adapted to prevent the differences in level from occurring in any joint portion between the joint block and the traveling path.
It is noted that the use of a joint block made of the same concrete as that of the traveling path may be adapted to provide more substantially increased slip resistance to the tires, as compared with the rubber or steel expansion joint. It is noted also especially that a high-strength fiber-reinforced concrete joint block is as highly durable as hardly worn away, and is thus considered to be suitably applicable to the joint block for use in the present invention.
The elastic members are desirably of a material that is hard to be deformed vertically and vice verse easy to be deformed horizontally in a soft manner. The present invention employs elastic members mainly consisting of laminated rubber. Further, the elastic members and the joint block are fitted to each other detachably by bolting or the like and consequently, may be easily given the maintenance thereof as well.
It would be possible also to mount supporting blocks inside the steps with the joint block between in order to protect the traveling path ends with the thus mounted supporting blocks so as to prevent the traveling path ends from being damaged due to tire impingement and/or impact responses and the like at the time of passage of the vehicles (see FIG. 2 ). The supporting blocks may be of concrete or high-strength fiber-reinforced concrete like the traveling path and the joint block.
In this case, the supporting blocks are fitted detachably to the intra-step traveling path side walls in close contact therewith with mounting bolts or the like to form a continuously extending traveling path surface and consequently, may be easily restored to normal by replacement even if damaged.
It would be possible also to mount, in a manner that one or more than one intermediate joint block is mounted inside the steps with the joint block between, more than one joint block in the traveling path joint in order to decentralize the expansion gap in the traveling path joint into more than one expansion gap to make the size of each individual expansion gap smaller, so that the occurrence of tire fall-in and/or stuck-in situations may be prevented more surely for the achievement of the increased driving quality (see FIG. 6 ). For instance, the size of the expansion gap in the traveling path joint may be reduced down to one fourth by mounting the intermediate joint blocks one by one to the opposite sides of the intra-step joint block.
Furthermore, the use of a joint block, supporting blocks and intermediate joint blocks that are of concrete of the same quality as that of the traveling path or of high-strength fiber-reinforced concrete may be adapted to lead to such advantage that the difference in level will be hard to occur in any joint portion between the blocks because of the substantially same-mannered developments of wear on each member, so that the difference-in-level management of the joints becomes more facilitated.
By reason of a structure which is such that members such as metal members and rubber members are not exposed to the traveling path joints, especially, to the traveling path surface, it is possible not only to eliminate the problems such as developments of rust on these members and degradations thereof but also to prevent scattering of these members for the achievement of the increased in-traveling safety for vehicles.
It would be possible also to provide, obliquely with respect to the axial direction of the traveling path, the expansion gap in a joint portion between each of the traveling path ends and the joint block in order to prevent the occurrence of tire fall-in and/or stuck-in situations particularly in cases of small-sized vehicles whose tires are small in diameter, while ensuring a required expansion gap (see FIG. 7 ).
It is noted that it is possible to prevent the occurrence of tire fall-in and/or stuck-in situations in cases of small-sized vehicles whose tires are small in diameter, while ensuring a required expansion gap, also by providing, obliquely with respect to the axial direction of the traveling path, the expansion gap in a joint portion between the joint block and each of the supporting blocks, that in a joint portion between the joint block and each of the intermediate joint blocks and that in a joint portion between each of the intermediate joint blocks and each of the supporting blocks.
In a method of mounting an elastic member in vehicle traveling path joints and the like having an expansion function and each composed of more than one step provided face to face at the coaxially built traveling path ends with an expansion gap between, more than one elastic member respectively mounted inside the above more than one step, and a joint block mounted on the above more than one elastic member across the above expansion gap, a method of mounting an elastic member in vehicle traveling path joints and the like having an expansion function comprises the steps of joining the above elastic members together across the above expansion gap and fixing the elastic member on one side to the step on one side, then subjecting the thus fixed elastic member to deformation toward the bridge girder axis, and thereafter fixing the elastic member on the other side to the step on the other side.
It is generally known in the bridge girders of RC construction, PC construction and/or steel-frame construction that the width of the expansion gap in the joint between the bridge girders varies with seasonal changes and temperature changes in a day as well. It is known also that the bridge girders of RC construction and/or PC construction easily produce fluctuations of the expansion gap width even with concrete drying shrinkage and/or creep effects
In designing the elastic member under such environments, it is the most economical as the elastic member that it is designed so as to permit no deformation to occur in the elastic member too at the time when the drying shrinkage and/or any shrinkage resulting from the creep has come to be convergent and besides, a bridge girder length varying with temperature has reached a median (i.e., a bridge girder length in time of ordinary temperatures) between a bridge girder length in time of high temperatures and that in time of low temperatures.
For that reason, the elastic member may be mounted without being affected by the seasons and/or the periods of time in a day and besides, by the bridge girder ages. Desirably, the elastic member should be so mounted that it will be conditioned to be free of any deformation therein at the time when the drying shrinkage and/or the creep of the bridge girders has come to be convergent and besides, the bridge girder length in time of ordinary temperatures has been reached.
In attempting to make setting of the expansion gap in conventional expansion joint applications in order to provide an expansion gap that meets a temperature at the time of mounting and/or the bridge girder ages, expansion gap adjustments have been made by taking steps of predicting a temperature at the time of mounting, then preliminarily adjusting the expansion gap width in a factory and the like, then temporarily fixing the expansion gap with an exclusive fixing jig or the like, and finally releasing the expansion gap from its temporarily fixed state after mounting in a construction site.
However, by reason that the temperature at the time of mounting is of a predicted value, it is necessary to make expansion gap readjustments in accordance with an actual temperature at the time of mounting in cases where the predicted value is much different from the actual temperature at the time of mounting, resulting in the need for troublesome mounting.
According to the present invention, it will be appreciated that it is possible to easily mount the elastic member without being affected in any way by the seasons and/or the periods of time and besides, by the bridge girder ages and the like so that it will be conditioned to be free of any deformation therein or in normal position whenever the bridge girder length in time of ordinary temperatures has been reached.
In this case, it would be possible also to set the expansion gap width in time of ordinary temperatures at a median between the greatest expansion gap width and the smallest expansion gap width in order to minimize the expansion gap of the greatest width and also to avoid bringing the bridge girder ends into contact with each other even if the expansion gap comes to be narrowed.
It is noted that the elastic members may be easily joined together by mounting, across the expansion gap over the elastic members, the joint block or a backing plate used to mount the joint block (see FIG. 9A ). It is noted also that the elastic members may be easily subjected to deformation by pressing them toward the bridge girder axis using an oil hydraulic jack or the like (see FIGS. 9B and 9C ).
According to the present invention, it will be appreciated that it is possible to prevent, by decentralizing the expansion gap in the joint between the bridge girders into more than one smaller-width expansion gap with the joint block while permitting the expansion gap function to be maintained, the occurrence of tire fall-in and/or stuck-in situations for the achievement of smooth vehicle traveling. It will be appreciated also that the components such as the joint block are fitted in detachable fashion by bolting or the like and consequently, may be easily given the maintenance thereof.
It will appreciated also that the present invention is adaptable for applications of various tire configurations different in tire diameter, ensures high slip resistance to the tires, permits less occurrence of tire fall-in and/or stuck-in situations, and is easy to be given the maintenance.
BRIEF DESCRIPTION OF THE DRAWINGS
Other features and advantages of the invention will become apparent from the following description taken in connection with the accompanying drawings in which:
FIG. 1A is a fragmentary side view showing the track of an urban transit system;
FIG. 1B is an enlarged plan view showing a portion A in FIG. 1A ;
FIG. 2A is a sectional view, taken on line B-B in FIG. 1B , showing one embodiment of a jointing structure in vehicle traveling path joints and the like having an expansion function according to the present invention;
FIG. 2B is a sectional view, taken on line C-C in FIG. 1B , showing one embodiment of a jointing structure in vehicle traveling path joints and the like having an expansion function according to the present invention;
FIG. 3A is an exploded sectional view showing one embodiment of a jointing structure in vehicle traveling path joints and the like having an expansion function according to the present invention;
FIG. 3B is a perspective view showing another embodiment of the jointing structure in the vehicle traveling path joints and the like having the expansion function according to the present invention;
FIG. 4A is a plan view showing the traveling path ends in the traveling path joints and the like;
FIG. 4B is a sectional view, taken on line D-D in FIG. 4A , showing the traveling path ends in the traveling path joints and the like;
FIG. 5A is a sectional view showing the behavior of an expansion gap in the traveling path joints and the like in association with bridge girder expansion or contraction caused by temperature changes or the like;
FIG. 5B is a sectional view showing the behavior of an expansion gap in the traveling path joints and the like resulting from bridge girder expansion caused by temperature changes or the like;
FIG. 5C is a sectional view showing the behavior of an expansion gap in the traveling path joints and the like resulting from bridge girder contraction caused by temperature changes or the like;
FIG. 6 is a sectional view showing a further embodiment of the jointing structure in the vehicle traveling path joints and the like having the expansion function according to the present invention;
FIG. 7 is a plan view showing a still further embodiment of the jointing structure in the vehicle traveling path joints and the like having the expansion function according to the present invention;
FIG. 8A is a plan view showing a still further embodiment of the jointing structure in the vehicle traveling path joints and the like having the expansion function according to the present invention;
FIG. 8B is a plan view showing a still further embodiment of the jointing structure in the vehicle traveling path joints and the like having the expansion function according to the present invention;
FIG. 9A is a sectional view showing a method of mounting an elastic member;
FIG. 9B is a sectional view showing a method of mounting an elastic member; and
FIG. 9C is a sectional view showing a method of mounting an elastic member.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1A to 5C respectively show one embodiment of the present invention wherein a bridge girder 2 serves to support a traveling path 1 adapted for vehicle traveling. The traveling path 1 is of concrete and extends continuously in a belt-like form on the bridge girder 2 in the axial direction thereof. The traveling path 1 is formed as an integral part of the bridge girder 2 and has an upper end surface in a flat form.
The bridge girder 2 is formed with manufactured girders such as RC girders, PC girders and steel girders. A joint between the bridge girders 2 , 2 has an expansion gap ±ΔL extending perpendicularly to the axis of the bridge girder 2 in order to absorb the expansion or contraction of the bridge girders 2 caused by temperature changes or the like.
Further, there is provided between the traveling paths 1 , 1 the same joint as the joint between the bridge girders 2 , 2 in the direction perpendicular to the axis of the traveling path 1 in conformity with the bridge girder joint, and the joint between the traveling paths 1 , 1 also has the same expansion gap ±ΔL as the expansion gap ±ΔL in the joint between the bridge girders 2 , 2 in the direction perpendicular to the axis of the traveling path 1 .
The traveling paths 1 , 1 have, at the ends thereof in the traveling path joint, steps 3 , 3 facing each other with the expansion gap ±ΔL between, and laminated rubbers 4 , 4 are respectively mounted inside the steps 3 , 3 with the expansion gap ±ΔL between.
The laminated rubber 4 is formed by piling up a thin rubber layer and a steel sheet alternately in multiple layers to place the rubber layers under restraint so that it will be hard to be deformed vertically and vice verse easy to be deformed horizontally in a soft manner.
Further, the laminated rubber 4 is formed in the shape of a rectangular parallelepiped lengthwise in the direction perpendicular to the axis of the traveling path 1 and has at a lower end thereof a base plate 4 a . And, the laminated rubber 4 is fixedly placed in detachable fashion on a bottom 3 a of each of the step 3 , 3 by fastening the base plate 4 a to the bottom 3 a with more than one anchor bolt 5 .
Further, a backing plate 6 is mounted on the laminated rubbers 4 , 4 across the expansion gap ±ΔL, so that the laminated rubbers 4 , 4 are integrally joined together through the thus mounted backing plate 6 . Thus, the laminated rubbers 4 , 4 are supposed to get deformed as a unit, following the expansion or contraction or the like of the bridge girders 2 as shown in FIGS. 5A , 5 B and 5 C.
FIG. 5A shows that the laminated rubbers 4 are being free of any deformation therein (or in normal position) as the result of no development of the expansion or contraction caused by temperature changes or the like on any bridge girder 2 , wherein the backing plate 6 is fixedly placed on the laminated rubbers 4 , 4 . From the seasonal point of view, such deformation-free state is considered to be that found in the spring and/or autumn time with the smallest difference in temperature.
FIG. 5B shows that the laminated rubbers 4 are being deformed such as to absorb the expansion of the bridge girders 2 caused by the temperature changes as the result of the narrowed expansion gap ±ΔL due to the above bridge girder expansion, and such deformed state is considered to be that found in the summer time from the seasonal point of view. Meanwhile, FIG. 5C shows that the laminated rubbers 4 are being deformed such as to absorb the contraction of the bridge girders 2 caused by the temperature changes as the result of the widened expansion gap ±ΔL due to the above bridge girder contraction, and such deformed state is considered to be that found in the winter time from the seasonal point of view.
It is noted that the laminated rubber 4 may be also in a square or circular-in-plan form, in which case, such laminated rubber may be mounted to the bottom 3 a in each step 3 in such a manner as to be placed in more than one position. Referring to FIG. 3B , there is shown one laminated rubber arrangement which is such that three pieces of square-in-plan laminated rubbers 4 are spaced at fixed intervals in the direction perpendicular to the axis of the bridge girder 2 .
The backing plate 6 is formed in the shape of a rectangular plate lengthwise in the direction perpendicular to the axis of the traveling path 1 , and is attached with, respectively in the center and at the opposite ends in the direction of the lengthwise sides thereof, projecting anchor bolts 7 .
Further, a joint block 8 is mounted on the backing plate 6 , and supporting blocks 9 , 9 are respectively mounted to the opposite sides of the joint block 8 with this joint block between.
Both the joint block 8 and each supporting block 9 are of the same concrete as the traveling path 1 and in the shape of a rectangular parallelepiped lengthwise in the direction perpendicular to the axis of the traveling path 1 , an upper end surface of the joint block 8 and that of each supporting block 9 being made flush with the upper end surface of the traveling path 1 .
The joint block 8 has, respectively in the center and at the opposite ends in the direction of the lengthwise sides thereof, loose holes 8 a , 8 b , into which the anchor bolts 7 are respectively inserted.
Further, the loose holes 8 a , 8 b are respectively charged with a hardening material 10 such as mortar. Thus, the joint block 8 is fixedly placed on the backing plate 6 .
It is noted that the loose hole 8 a is formed in the shape of a circular cone having a downwardly gradually increasing inner diameter, and the loose hole 8 b at each of the opposite ends of the loose hole 8 a is formed in the shape of a circular cone having an upwardly gradually increasing inner diameter.
By reason that the loose holes 8 a , 8 b respectively take the shapes as described the above, the joint block 8 is firmly fixed in three positions to the upside of the backing plate 6 . Further, the removal of the joint block 8 from the upside of the backing plate 6 , if required, can be made in such a relatively easy manner as to only crush the hardening material 10 in the loose hole 8 b.
Each supporting block 9 is fixedly fitted in detachable fashion to the side wall 3 b of each step 3 in close contact therewith with more than one mounting bolt 11 .
It is noted that it would be possible also to mount the joint block 8 directly on the laminated rubbers 4 , 4 with bolts, adhesives or the like in order to eliminate the need for the backing plate 6 so that a simplified structure may be provided.
With the above arrangements, it will be appreciated that the expansion gap ±ΔL in the joint between the traveling paths 1 , 1 is blocked up with the joint block 8 so that an expansion gap ±ΔL/2 smaller in width than the expansion gap ±ΔL is provided between the joint block 8 and each of the supporting blocks 9 at the opposite sides thereof, and this allows the occurrence of tire fallen-in and/or stuck-in situations in vehicles to be substantially reduced, resulting in the achievement of smooth vehicle traveling on the traveling path 1 . It will be appreciated also that the absorption of the expansion or contraction of the bridge girders 2 caused by the temperature changes or the like may be achieved as well thanks to the deformation of the laminated rubbers 4 , 4 .
It is noted that each expansion gap ±ΔL/2 in a joint portion between the joint block 8 and each of the supporting blocks 9 at the opposite sides thereof will be made uniform by adjusting the shear modulus of the laminated rubber 4 .
It will be appreciated also that the laminated rubbers 4 , the joint block 8 and the supporting blocks 9 are all fitted in detachable fashion so that the maintenance of the joints may be facilitated.
FIG. 6 shows another embodiment of the present invention which is especially such that the bottom in each step 3 is in the form of a two-stepped bottom composed of a bottom 3 a and a bottom 3 b extending in the axial direction of a traveling path 1 . In this embodiment, first-stage laminated rubbers 4 A, 4 A are respectively mounted on the first-stage bottoms 3 a , 3 a.
Further, a first-stage backing plate 6 A is mounted on the laminated rubbers 4 A, 4 A across an expansion gap ±ΔL, and on the first-stage backing plate 6 A is mounted a joint block 8 .
Furthermore, second-stage laminated rubbers 4 B, 4 B are respectively mounted on both the second-stage bottom 3 b and the first-stage backing plate 6 A, and on the second-stage laminated rubbers 4 B, 4 B is mounted a second-stage backing plate 6 B across a space between the laminated rubbers 4 B, 4 B.
Moreover, an intermediate joint block 12 is mounted between the joint block 8 and each of the supporting blocks 9 , wherein it is fixedly placed on the second-stage backing plate 6 B. The upper end surface of each supporting block 9 , that of the joint block 8 and that of each intermediate joint block 12 are made flush with the upper end surface of the traveling path 1 .
With the above arrangements, it will be appreciated that the expansion gap ±ΔL in the joint between the traveling paths 1 , 1 is blocked up with the joint block 8 so that an expansion gap ±ΔL/4 smaller in width than the expansion gap ±ΔL is provided between the joint block 8 and each of the intermediate joint blocks 12 at the opposite sides thereof and between each of the intermediate joint blocks 12 and each of the supporting blocks 9 , and this allows the occurrence of tire fallen-in and/or stuck-in situations in vehicles to be substantially reduced, resulting in the achievement of smooth vehicle traveling on the traveling path 1 . It will be appreciated also that the absorption of the expansion or contraction of the bridge girders 2 caused by the temperature changes or the like may be easily achieved as well thanks to the deformation of the laminated rubbers 4 , 4 .
It will be appreciated also that the laminated rubbers 4 B, 4 B, the joint block 8 , the intermediate joint blocks 12 and the supporting blocks 9 are all fitted in detachable fashion so that the maintenance of the joints may be facilitated.
It will be appreciated also that each expansion gap ±ΔL/4 in a joint portion between the joint block 8 and each of the intermediate joint blocks 12 at the opposite sides thereof and each expansion gap ±ΔL/4 in a joint portion between each of the intermediate joint blocks 12 and each of the supporting blocks 9 in the case of the embodiment shown in FIG. 6 can be made uniform by adjusting the shear modulus of the laminated rubber 4 .
FIG. 7 shows a further embodiment of the present invention which is especially such that joint portions between a joint block 8 and each of traveling path steps 3 at the opposite sides thereof respectively have mutually parallel expansion gaps ±ΔL/2 extending obliquely with respect to the axial direction of a traveling path 1 , wherein the joint block 8 is in a parallelogrammic-in-plan form whose two sides respectively facing the expansion gaps ±ΔL/2 are assumed to be oblique sides.
Other arrangements are substantially the same as the embodiment having been previously described with reference to FIGS. 1A to 5C . According to the embodiment in FIG. 7 , it will be appreciated that the occurrence of tire fall-in and/or stuck-in situations particularly in cases of small-sized vehicles whose tires are small in diameter may be reduced.
FIGS. 8A and 8B respectively show a still further embodiment of the present invention which is especially such that joint portions between a joint block 8 and each of supporting blocks 9 at the opposite sides thereof respectively have symmetrical expansion gaps ±ΔL/2 extending obliquely with respect to the axial direction of a traveling path 1 , wherein the joint block 8 is in a trapezoidal-in-plan form whose two sides respectively facing the expansion gaps are assumed to be oblique sides.
With the embodiment shown, the laminated rubber is supposed to be placed with no deformation developed therein (or in normal position) at the time when the expansion gap ±ΔL between the bridge girders 2 , 2 reaches its maximum due to the contraction of the bridge girders 2 caused by the temperature changes. Other arrangements are substantially the same as the embodiment having been previously described with reference to FIGS. 1A to 5C .
In such arrangements, shifting of the joint block 8 in the direction perpendicular to the axis of the traveling path 1 is applied to meet the fluctuations of the expansion gap ±ΔL with the expansion or contraction of the bridge girders 2 .
As shown in FIG. 8A , in cases where the expansion gap ±ΔL comes to be widened due to the bridge girder contraction caused by the temperature changes so that the laminated rubber deformation occurs to absorb such bridge girder contraction, the joint block 8 shifts in the direction shown by an arrow in association with the above laminated rubber deformation.
As shown in FIG. 8B , in cases where the expansion gap ±ΔL comes to be narrowed due to the bridge girder expansion caused by the temperature changes so that the laminated rubber deformation occurs to absorb such bridge girder expansion, the joint block 8 shifts in the direction shown by an arrow in association with the above laminated rubber deformation.
FIGS. 9A , 9 B and 9 C respectively show a method of mounting a laminated rubber for use in the embodiment having been previously described with reference to FIGS. 1A to 5C , and the procedure thereof will be described in the following.
(1) Firstly, the laminated rubbers 4 are joined together by placing the backing plate 6 across the expansion gap ±Δ over the laminated rubbers 4 , 4 respectively mounted inside the steps 3 (see FIG. 9A ). The backing plate 6 is joined to the laminated rubbers 4 by bolting or with adhesives or the like.
It is noted that it would be possible also to place the joint block directly across the expansion gap ±Δ over the laminated rubbers 4 , 4 in order to eliminate the need for the backing plate 6 .
(2) Subsequently, the laminated rubber 4 on one side is fixed to the bottom 3 a in the step 3 with the anchor bolts 5 . It is noted that the laminated rubber 4 on the fore side ahead of the expansion gap ±Δ is supposed to be fixed in cases where mounting of the laminated rubbers takes place in the summer time and the like considered that the bridge girder expansion will be ready to occur with increasing temperature (see FIG. 9B ). Meanwhile, it is noted also that the laminated rubber 4 on this side of the expansion gap ±Δ is supposed to be fixed in cases where mounting of the laminated rubbers takes place in the winter time and the like considered that the bridge girder contraction will be ready to occur with decreasing temperature (see FIG. 9C ). The anchor bolt 5 is fitted into a preliminarily embedded insert in the bottom 3 a. (3) Then, an oil hydraulic jack 13 is set inside the step 3 on one side. Then, the backing plate 6 is pressed out toward the bridge girder axis by bringing the oil hydraulic jack 3 into contact with the end of the backing plate 6 . By so doing, the laminated rubber 4 fixed to the bottom 3 a in the step 3 comes to be deformed toward the bridge girder axis. (4) Then, after the deformation of the laminated rubber 4 reaches a predetermined amount, the laminated rubber 4 on the other side is fixed to the bottom 3 a in the step 3 with the anchor bolts 5 . Then, the jack 13 is removed, and it therefore follows that the laminated rubbers 4 , 4 in such form as shown in FIG. 5B or 5 C will be obtained. It is noted that the anchor bolt 5 is fitted into the preliminarily embedded insert in the bottom 3 a.
It will be thus appreciated that the present invention is adaptable for applications of various tire configurations different in tire diameter, ensures high slip resistance to tires, permits less occurrence of tire fall-in and/or stuck-in situations and is easy to be given the maintenance.
While the preferred embodiments of the invention have been described, it is to be understood that changes and variations may be made without departing from the spirit or scope of the following claims. | A jointing structure comprising multiple steps provided face to face at the coaxially built traveling path ends with an expansion gap between, multiple elastic members respectively mounted inside the multiple steps, and a joint block mounted on the multiple elastic members across the expansion gap. Multiple supporting blocks and one or more than one intermediate joint block are mounted inside the multiple steps with the joint block between. The multiple supporting blocks, the joint block and the one or more than one intermediate joint block are of concrete. The elastic members are joined together across the expansion gap. The elastic member on one side is fixed to the inside of the step on one side and then subjected to deformation toward the bridge girder axis, and thereafter, the elastic member on the other side is fixed to the inside of the step on the other side. | big_patent |
BACKGROUND OF THE INVENTION
The present invention relates generally to track transport systems, and more particularly to floor track systems such as used in sanitary fluid treatment chambers for transporting thereinto food stuffs on wheeled hand trucks, or the like.
In processing cooked meat products, such as smoked meat and sausage, it is a conventional practice to roll racks or hand trucks loaded with cooked meat into a cooling chamber and circulate therethrough chilled air to cool the meat. This method of chilling the cooked meat has the major drawback of evaporating meat juices and thus causing excessive dehydration and shrinkage of the product. This dehydration, especially in meat products such as sausage or frankfurters results in difficulty in removing the cellulose casing. Another disadvantage of air chilling is that the rate of heat transfer from the meat to the air is relatively slow.
More recent approaches to chilling cooked meat products employ fluid treatment chambers with a system for showering the meat products with a chilled brine solution to quickly transfer the heat from the meat to the solution where it can be recovered, recooled and then recirculated. Because of the volume of water needed as part of the brine solution to cool the meat products is significant, it becomes economically advantageous to recover the brine solution from the chamber and recirculate it.
The meat products processed in this manner are generally for human consumption and must therefore be processed in a sanitary environment as required by the U.S. Department of Agriculture. It is also desirable to chill large quantities of meat products at one time, and be able to quickly move such large quantities about the processing plant as desired. The method of transporting cooked meat into and out of the fluid treatment chamber must maintain the sanitary condition of the chamber as well as the recovered brine solution.
One transport system used with a certain degree of success in cooling chambers is the overhead rail or trolley onto which product carriers, such as racks or trees, are suspended and automatically moved or manually pushed and pulled by a gaff or similar device. These overhead rail transport systems suffer the disadvantage of fixing the route of transfer. In other words, the meat products can only be moved to places where an overhead rail or trolley has been previously installed. Another disadvantage of the overhead trolley system, when used in recirculating brine solution environments, is that the solution which comes into contact with the lubricating grease on the transport wheels becomes contaminated, and cannot thereafter be used unless sterilized. This disadvantage has been overcome by locating the brine shower system below the overhead track system, and by employing a false ceiling between the shower system and the track system with slots in the ceiling through which the depending arm of the meat carriers move when transported. This slot can be covered with rubber flaps which seal the slot, but yet allow movement of the depending arm.
These and other disadvantages of the overhead rail system have, by and large, been overcome by the use of wheeled dolly-like floor trucks which can be pushed to any desired destination, or stored at remote seldom-used locations. The mobility advantage gained by the wheeled floor trucks is, however, offset by the unsanitary nature of the wheels which invariably become contaminated with foreign substances picked up from the processing plant floor.
The use of wheeled hand trucks to carry meat products into a sanitary chilling chamber has therefore presented an impediment to the recovery and reuse of the cooling brine solution. This problem can be circumvented by retreating to the air chilled chamber, but only at the expense of product dehydration and longer cooling cycles. It would therefore be advantageous to provide a chilling system which uses fluid as a quick cooling agent, along with wheeled hand trucks for quick and versatile meat products transportation, and also where the contamination attendant with the use of wheels is eliminated as a factor so that the cooling fluid maintains its sanitary nature and thus can be reused without incurring the expense of reprocessing it to a sanitary condition.
The primary object of the invention therefore is to provide a floor transport system which allows dolly-like floor trucks to be used in a fluid treatment center in a manner which prevents the wheels or other support structure on the dolly from contaminating the treatment fluid.
Another objective of this invention is to provide a floor transport track system where the wheels of the trucks used to support the product to be treated can be segregated from the recirculated treatment solution such that any objectionable contaminant on the wheels will not be carried into the treatment solution and prevent the reuse thereof.
Other objects of the invention will become apparent from the following detailed description of the various embodiments when considered in connection with the attached drawings.
SUMMARY OF THE INVENTION
In accordance with the invention there is provided an enclosed floor track system for use in a fluid treatment chamber for moving wheeled trucks, or the like, into and out of the chamber without contaminating the sanitary environment of such chamber.
In one embodiment of the invention the enclosed track includes a wheel channel into which the wheels of the truck roll, and which is disposed above the fluid level on the floor by support legs. The wheel channel includes opposed sidewalls one of which extends upwardly more than the other and which has attached to it a cover plate horizontally overlying the top of the channel. The vertical space between the shorter sidewall and the cover plate above it accommodates the axle structure connecting the truck frame to the wheel disposed in the channel. In this manner, the wheel channel standing off the floor, and the overlying plate prevent showered fluid, or fluid flowing on the floor, from entering the wheel channel area and becoming contaminated by the truck wheels.
The overlying cover plate may be connected to the longer sidewall by a hinge so that it can be pivoted away from the wheel channel and thereby facilitate the cleaning of the channel.
In another embodiment of the invention the enclosed floor track is structured to accommodate trucks with downwardly depending struts supporting the wheel structure. Here, the sidewalls of the wheel channel extend upwardly beyond the top of the wheel structure and include at the top edges thereof inflatable elastomer seals. These seals are hose-like and are attached along the length of the sidewall top edges so as to enclose around the hand truck wheel struts and prevent entry of the brine solution into the guide track. When inflated, the elastomer strips perfect a seal around the wheel struts, as well as against itself along the remaining length of the floor track.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric view of a fluid treatment chamber with which the present invention is well adapted for use.
FIG. 2 is a cross-sectional view of one embodiment of the enclosed floor track system adapted for use with a horizontally axled hand truck.
FIG. 3 is a cross-sectional view of another embodiment of the floor track system utilizing inflatable seals to enclose the interior wheel channel of the track.
FIG. 4, is a partial side view of FIG. 2, showing the floor track system pitched to drain away liquid.
DETAILED DESCRIPTION OF THE INVENTION
Referring generally to the drawings, the fluid treatment chamber utilizing the features and advantages of the present invention is generally identified by the reference character 10. While it should be realized that the present invention will be described in terms of use with a meat product chilling chamber, it should be understood that the principles of the invention are not limited thereto and thus may find applications in other industries. For example, wheeled hand trucks are only exemplary of the transport vehicles which may be used with the present invention. Other types of vehicles may, of course, be advantageously used.
Referring particularly to FIG. 1, the environment in which the present invention is commercially embodied includes a meat product chilling chamber 10, a brine distribution piping system 12, a return piping system 14, a brine receptor 16 and a brine recirculation pump 18. A control panel 20 is utilized to start and stop the brine circulation system, and also control the rate of flow of the brine solution.
The brine solution is pumped under pressure through the distribution piping system 12 where it is showered (not shown) onto meat-laden hand trucks, such as shown generally by reference character 22. The temperature of the cooked meat is quickly lowered by transferring the heat to the showered liquid which then drains off the meat and onto the tracks and floor below. The floor of this fluid treatment chamber is inclined to collect the warm brine solution in a sump (not shown) where it is then cooled by a refrigeration system (not shown) and returned to be cycled again. Because the liquid treatment chamber 10 and the associated circulation equipment does not form a part of the present invention, this disclosure will not be further encumbered by a detailed analysis of such apparatus.
The present invention relates to an enclosed floor track system for transporting the hand trucks 22 into and out of the fluid treatment chamber 10. Chamber doors 26 keep the showered brine solution contained within the chamber when closed, and when open permit the transportation of meat-laden hand carts 22 into and out of such chamber 10 via the floor tracks 24.
As discussed above, the present invention is well adapted for use in this environment by preventing the brine solution from being showered onto the wheel structure 28 of the hand trucks and becoming contaminated. FIG. 1 shows an open floor track 24 for the set of wheels 28 on one side of the hand truck, and another open track 25 for the other set of wheels 30. These tracks 24 and 25 extend to the entrance of fluid treatment chamber 10. Suitable ramps (not shown) can be provided to guide the wheels 28 of the truck 22 onto the floor tracks 24, 25. The floor tracks inside the cooling chamber are slightly pitched to drain any liquid within the tracks into a waste sewer (not shown). The majority of liquid which may enter the track system is water which is used to flush and thus clean the track system. Any brine solution which may leak into the track system becomes contaminated by the hand truck wheels 28 and 30, and is also drained to the waste sewer.
Turning now to FIG. 2 there is shown a cross-section of the enclosed floor track system as utilized within the fluid treatment chamber 10. It can be seen that some of the meat products 32 and 34 are suspended on the hand truck 22 directly over the tracks 36 where brine solution dripping off the meat products would be contaminated by the hand truck wheels 28 and 32 were it not for the enclosed floor tracks of the present invention. The enclosed tracks, generally indicated by reference character 36, as utilized within the fluid treatment chamber are supported above the chamber floor 38 by support legs 40. As noted by FIGS. 1 and 4, the sloping grade of the floor upon which the track system rests provides the floor tracks 36 with an incline sufficient to drain washing fluids into the waste sewer. The length of the support legs 40 may also be varied to achieve different angles of incline. The overall structure of the hand truck, except the wheels, and the chamber interior including the floor are sanitary. Thus, any brine solution coming into contact with the hand truck structure or chamber floor 38 is also maintained sanitary and can be reclaimed and recirculated. The enclosed floor track system shown in FIG. 2 prevents showered or dripping brine from entering into the track system, and what little solution which may enter the tracks and become contaminated is drained away separately from the solution 42 on the chamber floor 38.
The enclosed floor tracks shown in FIG. 2 are well adapted for use with hand trucks having horizontally axled wheel structures. The tracks 36 of this embodiment include an open wheel channel 44 into which the wheels 28 or 30 of the hand truck are moved in the chamber. Running along the length of the channel 44 and centrally located therein is a wheel guide 46 which keeps the hand truck centered within the bottom of the track system. The wheel guides 46 are welded to the wheel channels 44 which, in turn, are welded to the support legs 40. Each wheel channel 44 includes a bottom portion 48 and upwardly extending sidewalls 50 and 52. The outer sidewall 52 extends upwardly a distance greater than that of the inner sidewall 50.
A cover plate 54 generally overlies the top of the wheel channel 44 and is attached to the outer sidewall 52 by a hinge 56. This hinged connection permits the cover plate 54 to be pivoted away from the wheel channel 44 to facilitate cleaning it by flooding or otherwise. The outer sidewall 52 is angled inwardly at its top end 58 to serve as a rest stop for the cover plate 54 when it is swung to a position enclosing the floor track system. The vertical space between the upper edge of the inner sidewall 50 and the overlying cover plate 54 accommodates the horizontal axle structure 60 of the hand truck 22. The end of the cover plate 54 and the wheel channel inner sidewall 50 include end portions 62 and 64 respectively, bent to prevent splashing, spattering or running of the brine solution into the floor track system. Also, the cover plate 54 extends laterally beyond the inner sidewall 50 to form a drip edge and assure that no liquid falls or drips into the wheel channel area.
It is thus seen that the enclosed floor track system shown in FIG. 2 greatly enhances the recovery and reuse of the brine solution by segregating the hand truck wheel structure from the general environment within the fluid treatment chamber 10. Needless to say, the recovery and reuse of the brine solution preserves natural resources as well as achieves an economic advantage.
With reference now to FIG. 3 there is shown another embodiment of the enclosed floor track system according to the present invention. This embodiment also includes a wheel channel 44 for generally enclosing the wheel structure of a hand truck and thereby segregating such wheel structure from the environment of the fluid treatment chamber 10. The wheel chamber 44 includes a bottom portion 48 and also upwardly extending identically-structured sidewalls 66 and 68. The wheel channel 44 is somewhat wider than the width of a hand truck wheel at its bottom 48, and then angles upwardly a short distance, and then again vertically to form the sidewalls. The narrow track bottom 48, along with angled parts 70 form a wheel guide which maintains the hand truck wheels generally centered on the bottom of the track channel. The tendency of the wheels of a hand truck is to roll along the channel bottom 48 rather than climb the angled part 70 of the sidewalls.
The illustrated hand truck of FIG. 3 is of the type having a depending I-beam strut connecting the wheel section to the hand truck frame 74. The sidewalls 66 and 68 extend upwardly a distance such that the longitudinal edges thereof are proximate the center of the I-beam 72. The sidewall upper edges 76 have attached to the inner surfaces thereof inflatable elastomer-type seals 78. These seals are of the Nytryle type of material and are shown in FIG. 3 in the inflated state fitting snugly around the central part of the I-beam 72. These inflatable elastomer seals are commercially available and thus need not be discussed here in further detail. In the inflated state the seal 78 on each side of the I-beam section 72 makes firm contact with the I-beam and thereby prevents the brine solution from entering the guide track channel. At locations along the length of the guide track where there is no hand truck and thus no I-beam strut, the inflatable seals 78 will expand to seal against each other. When inflated, the seals 78 being closed tightly around the I-beam strut 72 also act as a brake on the meat-laden hand trucks so as to prevent movement of the trucks along the slightly inclined track system.
When it is desired to remove the hand truck 22 from the fluid treatment chamber 10 the compressed air within the seal 78 is released whereupon the seals are deflated leaving sufficient space between them for ease of movement of the I-beam 72 and thus the hand truck.
Each inflatable seal has a flat base section 80 compressed to its associated channel sidewall by two clamps 82 and 84. Clamp 84 may be fixed to the floor track sidewall by spot welding, and the top clamp 82 may be removably attached to the sidewall by suitable means, such as by a screw. The inflatable seal member brackets 82 and 84, as well as the enclosed wheel channels 44, are preferably constructed of stainless steel to resist corrosive attack by the brine solution.
It is readily seen that a need exists for the use of an enclosed floor track system, and that the present invention fulfills such need. In addition to preventing corrosion of the hand truck wheel bearings, and the deterioration of the rubber wheels, the enclosed track system according to the present invention prevents the brine solution from coming into contact with the hand truck wheels and becoming contaminated. Recirculation and reuse of the brine solution may thereby be effected without the need for decontaminating the brine solution.
Although the invention has been described above with a certain degree of particularity with respect to the apparatus involved, it should be understood that this disclosure has been made only by way of example. Consequently, numerous changes in the details and construction of the enclosed floor track system may be apparent to those familiar with the art and may be resorted to without departing from the scope of the invention as claimed. | An enclosed floor track system for use with wheeled hand trucks or the like in sanitary liquid treatment chambers. An elongate wheel channel into which the wheels of the truck are disposed includes a cover comprising either a cover plate or inflatable elastomer seals to prevent liquid from entering the contaminated wheel channel. In the cover plate embodiment the wheel channel includes an elongate side slot to accommodate the wheel axle structure. The inflatable seal is split to slidably receive a wheel axle structure. | big_patent |
BACKGROUND OF THE INVENTION
1. Technical Field
The present invention relates to a lock device which prevents a work machine of a construction machine from being tilted by the weight thereof. Especially, the present invention relates to a lock device which prevents a boom of a backhoe work machine from being rotated downward by the weight thereof.
2. Background Art
Conventionally, there is well known a so-called tractor loader backhoe constructed so that a loader is attached to a front portion of a traveling vehicle and a backhoe is attached to the rear portion thereof. With regard to such a kind of a tractor loader backhoe, a side column supporting a boom is standingly provided on a side frame at the front portion of the tractor, a bucket is supported at the tip of the boom, and the boom and the bucket can be rocked respectively by hydraulic cylinders, whereby a front loader is constructed. A boom is supported in the rear portion of the tractor so as to be rotatable vertically and laterally, an arm is supported at the tip of the boom so as to be rotatable vertically, a bucket is supported at the tip of the arm so as to be rotatable vertically, and each of them can be rotated by a hydraulic cylinder, whereby a backhoe is constructed.
The front loader is operated by an operation part arranged at a side of a seat. The backhoe is operated by a lever or the like provided on an operation column standingly provided on a frame of the rear portion while the seat is reversed longitudinally.
The tractor loader backhoe travels by wheels so that the tractor loader backhoe can travel at relatively high speed. At the time of traveling, if the loader or the backhoe which is a work machine is fallen by vibration, leak of pressure oil or the like, the travel may be hindered. Then, there is well known an art for locking the work machine at the time of not operating the work machine (for example, see the Patent Literature 1).
Patent Literature 1: the Japanese Patent Laid Open Gazette 2004-360331
BRIEF SUMMARY OF THE INVENTION
However, with regard to the art of the Patent Literature 1, the movement of the operation lever is restricted, and leak of pressure oil causes fall of the work machine by the weight thereof. Then, there is an art preventing the fall mechanically. For example, a lock member is provided at the rotary basal part of the boom and an operation member is extended from the operation column so as to operate the lock member, thereby locking the boom. However, the operation member always touches the lock member so that friction occurs every time each mechanism is actuated so that the touch part is abraded and rusts, whereby the life of the members is shortened.
Thus, the present invention is intended to provide a lock device comprising an engaging member and an engaged member such that lock operation can be performed manually easily.
The above-mentioned problems are solved by the following means.
According to a first aspect of the present invention, a lock device of a work machine including a main body and an excavating device is provided for locking a boom of the excavating device to the main body. In the lock device, an engaging member is provided on one of the boom and a boom bracket provided on the main body, and an engaged member is provided on the other of the boom and the boom bracket. The engaging member is constituted by a plate formed on one side thereof with a hook part, and on the other side thereof with a slot. A support pin is inserted into the slot, and a guide member is disposed above the support pin, so that the support pin and the guide member support the engaging member. The engaging member is provided on the other side thereof with first and second surfaces so that the first surface is parallel to the slot, and the second surface is slanted from the slot. When the engaged member is released from the hook part, either the first surface or the second surface can touch the guide member. When the engaged member is engaged with the hook part, the second surface touches the guide member.
According to a second aspect of the invention, the guide member is provided on the boom, and does not become horizontal while the boom is rotated between its highest position and its lowest position.
According to a third aspect of the invention, an end surface of the one side of the engaging member at which the hook part is positioned is enabled to touch the engaged member and is slanted toward a lengthwise center of the engaging member.
According to a fourth aspect of the invention, a slip-prevention plate is fixed to a tip of the support pin and the support pin can be inserted into the slot through the slip-prevention plate at a prescribed angle.
According to a fifth aspect of the invention, a member supporting the engaging member is projected from the boom bracket and the guide member is formed integrally with the boom bracket.
According to sixth aspect of the invention, the engaging member is provided with upper and lower guide members such as to slidably touch upper and lower surfaces of the other side of the engaging member.
The present invention constructed as the above brings the following effects.
According to the first aspect of the present invention, the lock device is constructed easily, and by sliding the engaging member along the slot and by touching the guide member with either the first or second surface of the engaging member, the engaging member can be held in the lock position or the lock release position.
According to the second aspect of the present invention, at any rotation position of the boom between the highest position and lowest position, the engaging member maintains the lock position, whereby it is not necessary to provide a holding mechanism for the engaging member so that the lock device is simplified and the cost is reduced.
According to the third aspect of the present invention, at the time that the engaging member moves to the lock side, when the boom is rotated to the lock position, the engaging member can evade by the slanting of the end surface of the one side of the engaging member, thereby preventing the engaging member and the engaged member from being damaged by their touching.
According to the fourth aspect of the present invention, the engaging member is inserted while the support pin is disposed at the predetermined angle, and the engaging member is prevented from slipping off by changing the angle of the support pin. Accordingly, the slip-prevention mechanism is constructed easily and it is not necessary to provide any slip-prevention member separately, whereby the number of parts is reduced, and the number of assembly processes is also reduced.
According to the fifth aspect of the present invention, it is not necessary to provide any guide member separately, whereby part number is reduced. It is not necessary to assemble the guide member, whereby number of assembly processes is reduced so as to reduce the cost.
According to the sixth aspect of the present invention, the engaging member is guided at its upper and lower sides, whereby the guide of the engaging member is stabilized so as to prevent ricketiness. Force applied on the guide member is dispersed into two, whereby the guide member is constructed small and the life of the lock mechanism is prolonged.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 It is an entire side view of a work vehicle according to the present invention.
FIG. 2 It is a side view of a lock device according to the present invention.
FIG. 3 It is a perspective view of the lock device.
FIG. 4 It is a side view of the lock device in a lock state.
FIG. 5 It is a side view of the lock device in the state that a boom is fallen to the lowest position.
FIG. 6 It is a side view of the lock device in the state that a lock plate is slid to a lock side so as to touch a lock pin.
FIG. 7 It is a perspective view of the vicinity of the boom that an operation lever is provided on the lock plate.
FIG. 8 It is a side view of an embodiment that the lock plate is provided at a side of a boom bracket.
FIG. 9 It is a rear view of the same.
FIG. 10 It is a rear view of the same in the state that a support pin is removed.
FIG. 11 It is a rear view of the same in the state that the support pin is inserted into the lock plate.
FIG. 12 It is a rear view of the same in the case that the support pin is in slip-prevention state.
DETAILED DESCRIPTION OF THE INVENTION
Next, explanation will be given on the mode for carrying out the present invention. FIG. 1 is an entire side view of a work vehicle according to the present invention. FIG. 2 is a side view of a lock device according to the present invention. FIG. 3 is a perspective view of the lock device. FIG. 4 is a side view of the lock device in the lock state. FIG. 5 is a side view of the lock device in the state that a boom is fallen to the lowest position. FIG. 6 is a side view of the lock device in the state that a lock plate is slid to lock side so as to touch a lock pin.
Firstly, explanation will be given on entire construction. A work vehicle 1 shown in FIG. 1 is a tractor loader backhoe equipped with a loader 2 and an excavating device 3 . An operation part 4 is provided at the center of the work vehicle 1 . The loader 2 is disposed before the operation part 4 , and a backhoe as the excavating device 3 is disposed behind the operation part 4 . The work vehicle 1 is equipped with front wheels 8 and rear wheels 7 so that the work vehicle 1 equipped with the loader 2 and the excavating device 3 is enabled to travel.
A steering wheel 5 and a seat 6 are disposed in the operation part 4 . A travel operation device and an operation device of the loader 2 are disposed at the side of the seat 6 . Accordingly, steering operation of the work vehicle 1 and operation of the loader 2 can be performed at the operation part 4 .
The loader 2 , i.e., a loading device, is connected to side portions of the work vehicle 1 and is extended forward, and a bucket is equipped on the tip of the loader 2 . An engine is disposed in the front portion of a frame 9 which is a chassis of the work vehicle 1 , and a bonnet 30 disposed on the frame 9 covers the engine. The loader 2 is disposed outside the bonnet 30 .
The work vehicle 1 is detachably equipped on the rear portion thereof with the excavating device 3 , and the excavating device 3 is operated with a lever and the like on an operation column 11 disposed behind the seat 6 .
A pressure oil tank 90 is disposed at a side portion of the operation part 4 , and the pressure oil tank 90 also serves as a step to the operation part 4 . A step constructed by a fuel tank is disposed at the opposite side of the operation part 4 .
An attachment part for a work machine is provided at the rear end of the frame 9 , and a work machine frame 13 of the excavating device 3 is fixed to the attachment part. The operation column 11 is standingly provided at the lateral center of the work machine frame 13 , and the operation lever and the like are disposed on the operation column 11 . Stabilizers 10 are provided at both left and right sides of the work machine frame 13 and can be rotated vertically by expansion and contraction of hydraulic cylinders 20 . A boom bracket 15 is attached to the rear portion of the work machine frame 13 so as to be rotatable laterally centering on the vertical axis and is rotated by a hydraulic cylinder (not shown). A basal part of a boom 16 is pivotally attached to the rear portion of the boom bracket 15 so as to be rotatable vertically centering on the lateral axis and is rotated by a boom cylinder 21 . A basal part of an arm 17 is pivotally attached to the tip of the boom 16 so as to be rotatable vertically centering on the lateral axis and is rotated by an arm cylinder 22 . A bucket 18 is attached to the tip of the arm 17 through a linkage mechanism so as to be rockable and is rocked by a bucket cylinder 23 .
As shown in FIG. 2 , the boom bracket 15 is substantially U-like shaped when viewed in side. Support parts 15 a and 15 b are respectively formed in the upper front portion and the lower portion of the boom bracket 15 . Support holes are respectively formed vertically in the support parts 15 a and 15 b . The boom bracket 15 and the work machine frame 13 are pivotally connected to each other through two pivot pins 27 which are lateral-rotation fulcrums so that the boom bracket 15 is laterally rotatably supported at the lateral center of rear portion of the work machine frame 13 . Two pivot parts 15 c are respectively formed in the lower portions of both left and right sides of the boom bracket 15 , and support holes are respectively formed vertically in the pivot parts 15 c so that each of the pivot parts is connected pivotally to a tip of a swing cylinder, whereby the boom bracket 15 is rotated laterally by the swing cylinder. A support part 15 d is projected rearward from the lower rear portion of the boom bracket 15 and a support hole is bore laterally in the support part 15 d so as to support pivotally the lower portion of the boom 16 by a pivot pin 25 . A support hole is bore laterally in the upper rear portion of the boom bracket 15 so as to pivotally support the lower portion of the boom cylinder 21 by a lock pin 54 also serving as a pivot pin.
Next, explanation will be given on a lock device 51 of the present invention according to FIGS. 2 to 6 .
The lock device 51 comprises the lock pin 54 provided in the boom bracket 15 of the vehicle so as to serve as an engaged member, a lock plate 52 serving as an engaging member of the work machine engaging with the lock pin 54 , and a guide member 53 keeping the lock plate 52 at a prescribed position.
Explanation will be given according to FIGS. 2 and 3 showing the state that the boom 16 is raised to the highest position (rotated forward).
The lock plate 52 and the guide member 53 are attached to the side surface of the boom 16 , and the lock pin 54 is projectively provided on the side surface of the boom bracket 15 . In addition, to the contrary, it may alternatively be constructed that the lock pin is attached to the boom and the lock plate is attached to the boom bracket. A hook part 52 a which is substantially C-like shaped and opened downward is formed at one of sides of the lock plate 52 , and a forward-slanted surface 52 b is formed at the tip (front end) of the lock plate 52 . The forward-slanted surface 52 b is slanted downward to the opened side of longitudinal center of the lock plate 52 when viewed in side.
A slot 52 c which is elongated longitudinally is opened at the other side (rear side) of the lock plate 52 . A support pin 55 is inserted into the slot 52 c so as to support the lock plate 52 rotatably and slidably. The support pin 55 is projectively provided on the side surface of the boom 16 along the same direction as the lock pin 54 .
The lock plate 52 is formed at the rear end thereof with a rearward-slanted surface 52 d , and is provided with a rear upper surface 52 e before the rearward-slanted surface 52 d so as to have an obtuse angle between the rearward-slanted surface 52 d and the rear upper surface 52 e . When the support pin 55 is positioned in the rear portion of the slot 52 c , the lock plate 52 can be rotated vertically between the lock position and the release position, while the angle of the lock plate 52 is regulated by the guide member 53 in cooperation with the rearward-slanted surface 52 d and the rear upper surface 52 e due to the substantially trapezoidal shaped rear portion of the lock plate 52 . Namely, as shown in FIG. 6 , the part where the rear upper surface 52 e is contiguous to the rearward-slanted surface 52 d is circular arc-like shaped centering on the axis of the support pin 55 while the lock plate 52 is slid forward. The slot 52 c is disposed parallel to the rear upper surface 52 e , and the shortest distance between the axis of the support pin 55 and the rear upper surface 52 e is the same as that between the axis of the support pin 55 and the rearward-slanted surface 52 d . In addition, though it is not shown in the drawings of this embodiment, it may alternatively be constructed that one of ends of a link or wire is connected to the part of the lock plate 52 in the vicinity of the hook part 52 a and the other end of the link or wire is connected to an operation member arranged in the operation part 4 , whereby the lock and release operation by the lock plate 52 can be performed by operating (pushing and pulling) the operation member at the operation part 4 .
As shown in FIG. 7 , it may alternatively be constructed that one of end of an operation lever 56 is supported in the vicinity of the hook part 52 a of the lock plate 52 and the other end of the operation lever 56 is engaged with the front side (back surface) of the boom 16 . The operation lever 56 is substantially inverse U-like shaped when viewed in front. The open end of the operation lever 56 is inserted into an engaged hole opened in the hook part 52 a and is pivotally supported. The other end of the operation lever 56 is extended upward along the boom 16 , and two engage fittings 57 constructed by metal leaves or the like are fixed to the front surface of vertical middle portion of the boom 16 so as to be engaged with both left and right sides of the other end of the operation lever 56 . Accordingly, when the lock plate 52 is disposed in the lock position or the release position, the other end of the operation lever 56 is engaged with and held by the engage fittings 57 , and at the time of operation, the closed side of the operation lever 56 is gripped by a hand and the operation lever 56 is rotated to this side so as to release the engagement, and then the lock or release operation is performed and the operation lever 56 is engaged with the engage fittings 57 again. In addition, though the lock plate 52 is provided at each of the left and right sides in this case, it may alternatively be constructed that the lock plate is provided at one of the left and right sides and operated by one operation lever. The engagement of the operation lever 56 is not limited to the above-mentioned construction.
The guide member 53 is formed by bending a plate L-like shaped when viewed in rear, and is fixed to the side surface of the support pin 55 at the side of basal part of the boom 16 so that the upper surface of the guide member 53 is projected sideward. In other words, as shown in FIG. 2 , when the boom 16 is positioned vertically (at the foremost position), the support pin 55 is positioned below the front end of the guide member 53 . In addition, the guide member 53 may alternatively be constructed integrally with the boom 16 . In the state of FIG. 2 , the distance between the support pin 55 and the guide member 53 is slightly longer than the distance between the inner surface of the slot 52 c and the rear upper surface 52 e of the lock plate 52 so that the lock plate 52 is attached longitudinally slidably. In the state of FIG. 4 , the distance between the support pin 55 and the guide member 53 is slightly longer than the distance between the inner surface of the slot 52 c and the rearward-slanted surface 52 d of the lock plate 52 . Accordingly, when the lock plate 52 is slid forward to the lock position, the lock pin 54 is engaged therewith and the rear portion of the rearward-slanted surface 52 d touches the lower surface of the guide member 53 so as to prevent further downward rotation of the lock plate 52 .
With regard to the tilt angle of the guide member 53 , as shown in FIG. 4 , when the boom 16 is rotated the foremost position, i.e., the lock position, and the hook part 52 a of the lock plate 52 is engaged with the lock pin 54 , the rearward-slanted surface 52 d is parallel to the guide member 53 and touches the guide member 53 , whereby the guide member 53 is slanted rearward. As shown in FIG. 5 , when the boom 16 is rotated to the lowest position, the angle between the guide member 53 and a horizontal line GL is positive. In other words, the angle of the surface of the guide member 53 touching the lock plate 52 is always positive (in the first or second quadrant).
Accordingly, when the lock plate 52 is in the release state that the rear upper surface 52 e touches the guide member 53 as shown in FIG. 2 , the state can be maintained even if the boom 16 is rotated to any position. Namely, even if the lock plate 52 is projected along the slot toward the bucket 18 by vibration or the like, the rear upper surface 52 e is fallen along the guide member 53 or the slot 52 c is fallen along the support pin 55 by the weight thereof so as to return to the original position. Even if the lock plate 52 is locked at the lowest position (projected), the lock plate 52 is rotated rearward by the weight thereof centering on the support pin 55 and slid downward so as to reach the release position automatically.
When the boom 16 is rotated forward so as to be locked at the time of finishing the work, even if the lock plate 52 is at the lock position (projected) by vibration or the like as shown in FIG. 6 , the forward-slanted surface 52 b touches the lock pin 54 so that the lock plate 52 is lifted and rotated upward centering on the support pin 55 , thereby prevented from being stretched against the guide member 53 and damaged. When the boom 16 is rotated to the foremost position while the lock plate 52 is projected, the lock pin 54 moved from the forward-slanted surface 52 b reaches the hook part 52 a of the lock plate 52 so that the lock plate 52 is engaged with the lock pin 54 so as to be locked.
The lock pin 54 is projectively provided from the side surface of upper rear portion of the boom bracket 15 and can be engaged with the lock plate 52 . In this embodiment, the lock pin 54 is arranged at the lower end of the boom cylinder 21 , that is, at a side of a fulcrum pin 26 pivotally supporting the tip of the rod. In addition, the lock pin 54 may alternatively be constructed integrally with the fulcrum pin 26 or constructed to also serve as the fulcrum pin 26 .
With regard to the above-mentioned construction, at the time of work of the excavating device 3 , the lock plate 52 is disposed at the release position where the rear upper surface 52 e touches the lower surface of the guide member 53 and the support pin 55 is positioned in the slot 52 c at the side of the center of the lock plate. When the vehicle travels after finishing the excavation work of the excavating device 3 , when the loader work is performed, or when the machine is to be stored, the boom cylinder 21 is contracted so as to rotate the boom 16 to the foremost position (toward the operation part 4 ). In this state, the lock plate 52 is pulled forward and rotated downward about the rear portion of the slot 52 c as a fulcrum so as to engage the hook part 52 a with the lock pin 54 , whereby the boom is locked. Accordingly, the boom 16 is prevented from being unexpectedly rotated forward by vibration, leak of operating oil or the like.
When the lock is released, in the order opposite to the above mentioned, the front portion of the lock plate 52 is lifted, the hook part 52 a is disengaged from the lock pin 54 , and then the lock plate 52 is slid rearward along the slot 52 c to the release position.
Next, explanation will be given on another embodiment that the lock device 51 is provided on the boom bracket according to FIGS. 8 to 11 .
With regard to the lock device 51 , the lock pin 54 as the engaged member is projected sideward (not shown) from the side surface of the boom 16 of the work machine, a lock plate 60 as the engaging member to engage with the lock pin 54 is provided on the boom bracket 15 of the vehicle, and guide members 58 and 59 are disposed in the boom 16 so as to hole the lock plate 60 at a prescribed position and to guide the lock plate 60 at the time of operation.
The lock plate 60 , formed in the substantially same shape as the lock plate 52 , includes a hook part 60 a , a forward-slanted surface 60 b and a slot 60 c . Since the boom bracket 15 is not tilted forward or backward at the time of work, the lock plate 60 does not comprise any rearward-slanted surface. The lower guide member 58 and upper guide member 59 guide the upper and lower parallel surfaces of the lock plate 60 , and are projectively provided integrally on the side surface of the boom bracket 15 . A support pin 61 is disposed in the substantial middle of the guide members 58 and 59 . The lower guide member 58 is longer than the upper guide member 59 so that the lock plate 60 is held stably by the weight thereof while released, and the lower surface of the lock plate 60 touches the upper rear tip of the lower guide member 58 while locked.
When the lock plate 60 is shifted from the released state to the locked state, the upper guide member 59 touches the upper surface of the lock plate 60 , and is slid thereon so as to guide the lock plate 60 stably. The guide member 59 reaches the place above and before the support pin 61 so that the lock plate 60 can be rotated rearward downward after reaching the highest position. A lower end of an operation lever 62 is fixed to the hook part 60 a , and the grip of the operation lever 62 is extended upward forward toward the operation part so as to make the operation easy.
In the state that the boom 16 is rotated to the foremost position, the lock plate 60 is lifted upwardly rearward by operating the operation lever 62 while being guided by the guide members 58 and 59 , and then while the support pin 61 touches the end of the slot 60 c , the lock plate 60 is rotated downwardly rearward so as to be engaged with the lock pin 54 , whereby the lock operation has been performed. Otherwise, when the boom 16 is not positioned at the foremost position and the lock plate 60 is slid upward and rotated rearward by the operation lever 62 so that the upper front portion of the lock plate 60 is separated from the guide member 59 , the lock pin 54 touches the forward-slanted surface 60 b by rotating the boom 16 forward so that the lock plate 60 is slid, lifted and engaged automatically with the hook part 60 a similarly to the above mentioned, whereby the lock operation has been performed.
With regard to the release operation, opposite to the above mentioned, the lock plate 60 is rotated rearward by operating the operation lever 62 so as to be released from the lock pin 54 , and then is pulled rearward so as to be held at the released position.
The support pin 61 supports the lock plate 60 and pivotally supports the tip of the piston rod of the boom cylinder 21 . The slip-prevention construction after inserting the support pin 61 to the lock plate 60 is made simple so as to reduce part number and make the assembly easy.
A slip-prevention plate 64 is fixed to the tip of the support pin 61 and the slip-prevention plate 64 is rotated so as to make the prescribed angle which is the same as that of the slot 60 c , thereby enabled to be inserted into the lock plate 60 . After the insertion, the support pin 61 is rotated to the fixed position so as to be prevented from slipping off from the slot 60 c.
Namely, an oval rotation-prevention plate 63 is fixed to one of ends of the support pin 61 perpendicularly to the axis, and a bolt hole 63 a is opened at the tip of the rotation-prevention plate 63 . Then, a bolt of the like is screwed into a bolt hole 15 e opened in the boom bracket 15 so as to prevent the support pin 61 from being rotated at the time of work, and to fix the angle of the support pin 61 .
A small diameter shaft part 61 a , whose diameter is in agreement with the shorter diametric width of the slot 60 c of the lock plate 60 , is formed in the other end of the support pin 61 so as to be inserted into the lock plate 60 . A slip-prevention plate 64 is fixed to the tip of the support pin 61 perpendicularly. The slip-prevention plate 64 is constructed so that upper and lower sides of a disc larger than the shorter diametric width of the slot 60 c are shaved so as to form slot surfaces, whereby the disc is formed ovally. The width of the slip-prevention plate 64 in its shorter direction is substantially in agreement with that of the slot 60 c so that the small diameter shaft part 61 a of the support pin 61 can be inserted into the lock plate 60 in the state that the slip-prevention plate 64 is disposed parallel to the slot 60 c.
As shown in FIGS. 8 , 10 and 11 , in the state that the lock plate 60 is arranged between the guide members 58 and 59 and the lengthwise direction of the slot surfaces of the slip-prevention plate 64 of the support pin 61 are parallel to the lengthwise direction of the slot 60 c , the support pin 61 can be inserted into the lock plate 60 . The position of the support pin at which the support pin can be inserted into the lock plate 60 is offset from the bolt hole 63 a of the rotation-prevention plate 63 and the bolt hole 15 e of the boom bracket 15 .
In this state, by pushing the support pin 61 as shown in FIG. 9 , the small diameter shaft part 61 a is inserted into the slot 60 c . After the insertion, as shown in FIG. 12 , the slip-prevention plate 64 is rotated so as to make the bolt hole 63 a in agreement with the bolt hole 15 e and then a bolt is screwed into the bolt holes, whereby the ends in the lengthwise direction of the slip-prevention plate 64 overlap the part of the plate around the slot 60 c so that the lock plate 60 cannot be pulled off from the support pin 61 . Furthermore, the lock plate 60 is regulated its upper and lower sides by the guide members 58 and 59 and can be slid only in the lengthwise direction of the slot 60 c . Accordingly, even if the lock plate 60 is slid to any position, the lock plate 60 is prevented from being removed by the slip-prevention plate 64 . In addition, the slip-prevention is also adoptable to the construction that the lock plate is attached to the side of the boom.
Accordingly, at the time of assembly of the lock plate 60 , the support pin 61 is inserted into the boom bracket 15 and the tip of the piston rod of the boom cylinder 21 and the slot surfaces of the slip-prevention plate 64 is made parallel to the lengthwise direction of the slot 60 c , and then the support pin 61 is inserted into the lock plate 60 . After that, only by rotating the rotation-prevention plate 63 , the lock plate 60 is prevented from slipping off, whereby the assembly can be performed easily.
INDUSTRIAL APPLICABILITY
The lock device according to the present invention is adoptable for locking a boom, an arm or the like in the state of stored in a main body, and is available in an excavating device, a loader, a crane and the like. | A lock device is improved in durability by operating the operation member of a boom lock device in a non-contact state to solve a problem in a conventional work machine because there is a problem that the operation member is worn at the lateral rotating part of a boom bracket. In the lock device 51 for locking a boom 16 of the excavating device to the main body, an engaging member is provided on one of the boom and a boom bracket 15 provided on the main body, and an engaged member is provided on the other of the boom and the boom bracket. The engaging member is constituted by a plate formed on one side thereof with a hook part 52 a , and on the other side thereof with a slot 52 c . A support pin 55 is inserted into the slot, and a stopped 53 is disposed above the support pin, so that the support pin 55 and the stopper 53 support the engaging member. | big_patent |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to swimming pool vacuum cleaning devices. More particularly, the invention concerns a swimming pool vacuum cleaning apparatus having a flexible platform the central, vacuum portion of which is readily adjustable relative to the pool bottom to enable precise regulation of suction efficiency during the pool cleaning operation.
DISCUSSION OF THE INVENTION
2. Introduction
Several types of devices have been suggested for cleaning swimming pools using a suction source such as the pool circulation pump. Typically, these prior art devices include a suction head which is connected to a flexible suction line and then moved manually across the pool bottom using an elongated handle which is connected to the suction head. Devices of the aforementioned character are described in U.S. Pat. Nos. 3,805,309 issued to Levack; 4,402,101 issued to van Zyl; and 4,637,086 issued to Goode.
A drawback of many of the prior art devices resides in the fact that there is no expeditious way to regulate the suction being exerted by the device during the cleaning operation. Because the suction pressure available varies widely from pool to pool there is a real need to have a simple adjustment on the vacuum head itself to enable real time adjustment of the suction being exerted by the vacuum head without having to adjust the vacuum at the circulation pump. As will be appreciated from the discussion which follows, the apparatus of the present invention overcomes the drawbacks of the prior art by providing an adjustment on the vacuum head itself which enables the quick and easy regulation of the amount of suction being exerted by the suction head.
In the device of the preferred form of the invention, the suction adjustment is accomplished using conveniently located adjustment mechanisms provided on the top of the suction head. These adjustment mechanisms precisely regulate the spacing between the lower surface of the central, suction portion of the suction head and the bottom of the pool.
In the devices of the previously identified U.S. Pat. Nos. 4,402,101 and 4,637,086, adjustment of the spacing between the suction head and the pool bottom can be done by separately adjusting the position of each of the rollers with respect to the base or platform of the device. However, such adjustments are difficult and time consuming and are of little value to commercial pool cleaning operators who must use the vacuum head for continuous cleaning of a number of pools having suction sources of widely varying capabilities.
With respect to devices of the general character described in U.S. Pat. No. 4,637,086 wherein the individual wheel carrying axles of the wheel assemblies use movable upwardly and downwardly within slots provided in outwardly extending rib sections, the adjustment means of the present invention can frequently be added to the existing devices with relatively minor changes to the device being required. This aspect of the present invention will be discussed in greater detail in the paragraphs which follow.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a swimming pool vacuum cleaner in which the vacuum head can be readily adjusted with respect to the pool bottom so that the effective suction being exerted by the suction head can be easily regulated on a real time basis during the pool cleaning operation.
Another object of the invention is to provide a pool cleaner of the aforementioned character in which the adjustment mechanisms are conveniently located on the top of the vacuum head and can be quickly operated by hand without the need for hand tools.
Another object of the invention is to provide a pool cleaner of the character described in the preceding paragraphs in which the suction exerted by the vacuum head can be precisely regulated without the need for regulation of the remotely located suction source.
Still another object of the invention is to provide adjustment mechanisms in kit form which can be interconnected with certain types of existing, prior art pool cleaning devices without the need for major retrofit of the existing devices.
A further object of the invention is to provide an adjustment mechanism of the aforementioned character which is simple and easy to use, easy to connect to existent devices and one which can be manufactured very inexpensively.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a generally perspective view of the adjustable pool vacuum head of the present invention.
FIG. 2 is an enlarged top plan view of the apparatus of the invention.
FIG. 3 is a cross sectional view taken along lines 3--3 of FIG. 2.
FIG. 4 is a cross sectional view taken along lines 4-- 4 of FIG. 3.
FIG. 5 is a cross sectional view taken along lines 5--5 of FIG. 2.
FIG. 6 is a cross sectional view taken along lines 6--6 of FIG. 5.
FIG. 7 is a cross sectional view taken along lines 7--7 of FIG. 2.
FIG. 8 is a cross sectional view taken along lines 8--8 of FIG. 7.
FIG. 9 is a cross sectional view similar to FIG. 8, but illustrating the adjustability of the device to raise the suction portion thereof a greater distance above the bottom of the pool surface.
FIG. 10 is a cross sectional view taken along lines 10--10 of FIG. 9.
DESCRIPTION OF THE INVENTION
Referring to the drawings and particularly to FIGS. 1 through 3, the suction head assembly of the present invention comprises a generally rectangular, horizontally extending platform 12 having a central portion 14, longitudinally extending edges 16, longitudinally spaced end portions 17 and a plurality of longitudinally spaced, transverse stiffening ribs 18. The central portion of platform 12 is provided with an opening 20 and an upwardly extending cylindrical member 22 in communication with opening 20. As indicated by the phantom lines in FIGS. 1 and 7, cylindrical member 22 is adapted for interconnection with a flexible suction line which, in turn, is interconnected with a source of suction such as the pool circulation pump. A handle assembly 24 of standard construction is pivotally interconnected with platform 12 proximate the center portion 14 thereof and is used for moving the suction head across the bottom of the pool. The platform 12 and cylindrical member 22 are preferably integrally formed from a yieldably deformable plastic material.
A first, or outboard roller assembly 26 is connected to to platform 12 proximate each end portion 17 thereof. In the instant form of the invention, each outboard roller assembly 26 comprises a pair of spaced apart ribs, or walls 28, the end portions of which extend outwardly from the longitudinally extending edges 16 of the platform. As best seen in FIG. 3, each end portion of each rib member 28 is provided with a vertically extending slot 30. An axle 32 spans the adjacent walls 28 and is vertically movable within slots 30. Axles 32 function to rotatably support rollers 34, which, as shown in FIGS. 3 and 4, are adapted to engage the pool bottom B. Each axle 32 is threaded at one end to threadably receive a wing nut 36 and is provided at its other end with a head 37. By tightening and loosening wing nut 36 relative to walls 28 each axle 30 can be vertically adjusted within slots 30. In this way, the vertical height of the rollers 34 can be adjusted relative to platform 12, thereby adjusting the spacing between the pool bottom and the outboard end portions 16 of the platform 12. As will be discussed in greater detail hereinafter, adjustment of the end portions of the platform is rarely necessary because of the novel adjustability feature of the central, suction portion of the platform, the details of which will presently be described. Also, forming a part of the outboard wheel assemblies 26, is an elongated lead weight 40 and a cover 42 which is interconnected with platform 12 by a threaded connector 44 (FIG. 3).
An important aspect of the apparatus of the present invention is the second, or inboard roller assemblies 46 which are interconnected with platform 12 on either side of central opening 20. As best seen by referring to FIG. 5, the construction of the inboard roller assemblies 46 is somewhat similar to the construction of the outboard roller assemblies just described. For example, each of the outboard roller assemblies includes a weight housing having spaced apart ribs, or walls 48 (FIG. 8), each of which has an end portion 48a which extends outwardly from edges 16 of platform 12. Each end portion 48a is provided with a vertical slot 50 adapted to closely receive an axle member 52 which rotatably carries a roller 58 intermediate space member 52 which rotatably carries a roller 58 intermediate space apart end portions 48a. Each of the inboard roller assemblies 46 also includes a weight 54 and a cover 56 which is superimposed over weight 54.
A highly novel feature of the apparatus of the present invention resides in a specially configured frame member 60 which is connected to and spans platform 12 in the manner best seen in FIGS. 2 and 5. Each frame member 60 has a central portion 62 and spaced end portions 64 which extend outwardly on either side of longitudinally extending edges 16 of platform 12. As indicated in FIGS. 1 and 6, each end portion 64 of each frame member 60 includes downwardly extending, spaced apart legs 64a, each of which is provided with an aperture 68 adapted to closely receive the ends of axles 52. Legs 64a are closely receivable over walls 48 in the manner shown in FIG. 8. Frame members 60 can be constructed of metal, rigid plastic or any suitable, durable material.
The central potion 62 of each frame member 60 is provided with an aperture 70 (FIG. 8) which is adapted to closely receive a connector means, shown here as an elongate connector 72 which comprises a part of the adjustment means of the invention. As indicated in FIG. 8, connector 72 has a head portion 72a which is received in a counter bore 73 provided in platform 12 and a threaded shank portion 72b. Shank portion 72b is received through an aperture provided in each weight 54 and in each cover 56. The upper end of each connector 72 extends through the apertures 70 of the frame members 60 for interconnection with a wing nut 74 which can be threaded downwardly into engagement with the upper surface of each frame member 60 in the manner shown in FIG. 8. By tightening the wing nuts 74 against the upper surface of each frame member 60, each axle 52 will be caused to move downwardly within slots 50 from a first position shown in FIG. 5 to a second position shown in FIG. 10. This downward movement of axles 52 lowers the wheels 58 relative to platform 12 from the position shown in FIG. 8 to the position shown in FIG. 10. Lowering of wheels 58 causes an upward deformation of platform 12 in the manner shown in FIG. 9 so as to increase the spacing between the central, suction portion of the platform 12 and the pool bottom B.
Disposed intermediate the inner surface of each frame member 60 and the top surface of each cover 56 is a biasing means shown here as a coil spring 78. Coil spring 78 functions to yieldably resist downward movement of frame 60 from the position shown in FIG. 5 wherein the spring is expanded to the lowered position shown in FIG. 10 wherein the spring is compressed. It is apparent that by raising and lowering the rollers in the manner described to vary the spacing between the central, suction portion of the platform the effective suction of the device can be precisely regulated without having to adjust the suction at the suction source.
As previously mentioned another aspect of the present invention is a roller height adjustment device which can be provided in kit form for use in combination with certain types of prior art suction head assemblies. More particularly, the roller height adjustment device of the invention is usable in combination with a suction head assembly for sweeping a swimming pool using a section line connected to a source of suction of the character having a generally horizontally extending platform having a central portion longitudinally extending edges, and longitudinally spaced end portions, the end portions having an opening therethrough adapted for connection with the suction line. The suction head assembly must also have a first roller assembly connected to the platform proximate each end portion thereof with each roller assembly comprising at least two rollers adapted to maintain the end portions of the platform in a spaced relationship with respect to the bottom of the swimming pool. Finally, the suction head assembly must have a roller construction disposed on either side of the opening in the central portion of the platform with each roller construction including a housing connected to the platform having spaced apart walls including end portions having vertical slots formed therein and a pair of axles received within the vertical slots for rotatably carrying a pair of rollers for rotation about the axle between the end portions of the spaced apart walls. Preferably the roller construction of the existing suction head assembly will also have a lead weight disposed intermediate the walls of the housing, a cover member superimposed over the lead weight and a threaded connector for interconnecting the cover member with the platform of the suction head. Such a construction is shown in the right hand portion of FIG. 8 wherein the weight is designated by the numeral 40, the cover is designated by the numeral 42 and the threaded connector is designated by the numeral 44.
With a suction head assembly of the aforementioned character, the roller height adjustment device of the present invention can readily be assembled to the suction head assembly with minimum modification thereto. More particularly, the roller height adjustment device of the invention comprises a pair of frames 60 adapted to be positioned over the walls of the housing of the roller construction so as to span the platform in the manner shown in FIG. 2. Each frame 60 is of a construction previously described herein and includes transversely spaced end portions 64a each having an aperture 68 therethrough of the character shown in FIG. 6. Apertures 68 are adapted to closely receive the axles of the roller construction of the device so that an axle such as an axle 52 will extend through aperture 68 provided in frame 60 as well as through the vertical slots provided in the end portions of the spaced apart walls of the roller construction of the device. In some instances it may be necessary to replace the axles of the existing suction head with slightly longer axles.
The roller height adjustment device of the present form of the invention further comprises connector means for connecting each frame 60 to the platform of the existing device and adjustment means associated with each frame 60 for vertically adjusting the axle of each roller construction within the slots provided in the end portion of the walls of the housings of the roller constructions. In the form of the invention shown in the drawings, the connector means is provided in the form of an elongated connector such as that previously described and identified in the drawings by the numeral 72. This elongated connector includes a threaded shank portion 72 and a head portion 73. The connector is of the same general configuration as the connector used in the existing device to maintain the cover in position over the weight and the housing. However, the connector 72 is slightly longer so that the threaded upper end thereof will protrude through the central aperture provided in the frame member 60 in the manner shown in FIG. 8.
The adjustment means of this form of the invention comprises a wing nut, such as that previously described and identified by the numeral 74, which can be threadably received over the upper threaded end of the shank portion of the connector 72. The adjustment means of the invention also includes a coil spring, such as that previously identified by the numeral 60, which is adapted to be disposed intermediate the lower surface of frame 60 member and the cover 42 of the existing suction head.
The roller height adjustment device of the present invention, when sold in kit form, comprises a frame such as frame 60, an elongated connector such as connector 72, a wing nut such as wing nut 74, a coil spring such as coil spring 72 and four axles such as axles 52. Assembly of the adjustment device of the invention to an existing unit is quite simple and involves the following steps. First, the existing connector such as a connector 44 is disconnected from the closure cap which secures the weight in position within the housing of the roller construction. The cover and weight are then removed and the replacement connector element 72 is inserted through the weight in the manner shown in FIG. 8 with the head of the connector being disposed within the counter bore provided in the platform of the suction head. If necessary, the cover, such as cover 42, is then drilled out to receive the shank portion of the connector 72. Next, each of the axles of the inboard roller constructions of the existing device is removed from the vertically slotted spaced apart walls. With the axles removed and the connector element 72 in place, the coil spring is placed over the shank portion of the connector. This done, the frame 60 can be placed over the spaced apart walls, such as walls 48, so that the apertures in the downwardly extending legs thereof align with the slots in the wall portions of the existing device. As the frames 60 are implaced over the walls 48, the upper end of the connector 72 is inserted through the aperture 70 provided in the central portion of each frame 60. With the frame 60 thusly in position, each of the axles 52 can be inserted through the apertures provided in the downwardly extending leg portions of the frame member 60 and through the vertical slots provided in the side walls of the inboard roller construction of the existing device. The wing nuts 74 can then be threaded over the upper end of shank 72b, thereby completing the retrofit of the existing suction head assembly. With the frames 60 thusly positioned, precise adjustment of the inboard rollers relative to the platform can be accomplished in the manner previously described herein.
Having now described the invention in detail in accordance with the requirements of the patent statutes, those skilled in this art will have no difficulty in making changes and modifications in the individual parts or their relative assembly in order to meet specific requirements or conditions. Such changes and modifications may be made without departing from the scope and spirit of the invention, as set forth in the following claims. | A swimming pool vacuum cleaning apparatus having a flexible platform, including an apertured central portion adapted for interconnection with a suction line, a pair of outboard roller assemblies for maintaining the end portions of the platform in a spaced relationship with the pad bottom and a pair of inboard roller assemblies which are readily vertically adjustable relative to the platform so that the spacing between the central, suction portion of the platform and the pool bottom can be quickly and easily adjusted during the pool cleaning operation. The inboard roller assemblies as individual units can also readily be attached to certain types of existing cleaning apparatus to provide an improved vertical adjustment feature. | big_patent |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to oil well drilling tools and apparatuses. More particularly, the present invention relates to an apparatus for retrieving the wear bushing from around the interior of the well head and casing, including a sub-unit for mounting there onto the drill string.
2. General Background
Wear sleeves or wear bushings, as they are called, are utilized during oil and gas well drilling and other operations on wells to protect against excessive wear, in particular, the wear bushings prevent wear to seal areas of casing heads and other well head elements, including the joint of the housing and the initial length of pipe or casing to which it is secured.
In U.S. Pat. No. 3,747,914 issued to Slack, the wear sleeve is equipped with an interior bore smaller in diameter than the width of the bit so that the sleeve may be somewhat loosely incorporated on the drill string, resting on the drill bit and lowered to its position in order to operate as a drill string is run into the hole and retrieved from the bit as the bit is withdrawn following the drilling process. However, often times it may be desirable to retrieve the wear sleeve or bushing without the use of the bit. For example, when the drill pipe is lodged, the pipe may be backed off above the drill bit and withdrawn from the hole leaving the drill collar and bit itself down in the hole.
In order to retrieve the drill collars and bit, it is necessary to wash over with a wash over string larger in inside diameter than the outside diameter of the drill collar and equal to that of the bit itself. Due to the size, the aforementioned equipment will not go through a normal wear sleeve, and it becomes necessary to remove the wear sleeve or bushing.
One of the methods utilized in the present state of the art, as exhibited in U.S. Pat. No. 3,489,214 issued to Phipps, et al, the removal of the wear sleeve or bushing in those instances when removal of the bit is undesirable or impossible as taught. One would use a wear sleeve or bushing section providing with what is called a J-slot and a retriever body having outwardly protruding dowels or the like for engaging the J-slot. The dowels or the like would protrude around the entire radias of the retriever body. This retriever is incorporated in the drill string with the usual pin and box threaded upper and lower ends. In the preferred embodiment, the tool is a body having a longitudinally through bore large enough to pass over the upset end of a pipe, a plurality of segmental split sleeves slidably into the bore of the end facing away from the pipe upset end; means defining a lineable opening radially through the body in splits sleeves; the split sleeves having lower end surfaces adapted to seat on the rear of the pipe upset end; screws threadably advancable in said openings, partly through the body, and to the respective sleeves and into engaging with the exterior of the pipe to secure the two together and prevent its rotation with respect to the pipe. Protruding means such as radial projecting pins are provided on the tool for engaging a cooperating means on the wear sleeve or similar element.
One of the short comings of this particular apparatus as taught in U.S. Pat. No. 3,489,241 is the fact that the retriever body must be secured in rigid engagement with the exterior of the pipe so that it will not rotate with respect to the pipe. This shortcoming shall be discussed in the latter sections of this application.
GENERAL DISCUSSION OF THE PRESENT INVENTION
The present invention would solve the problems in the present state of the art in a simple and inexpensive, straight-forward manner. The apparatus of the present invention provides for a sub-body having a mandrel with a longitudnal bore therethrough having a rigidly attached upper collar section for engagement onto a section of pipe or the like, and having a threadably removable lower collar section for threadably engaging the end of a second lower section of drill pipe, insertable onto the mandrel or body section of the sub-unit is a retriever section, which is substantially circular in nature and slidably movable between the end collars of the sub-unit. The retriever section is adapted with means, for example, protruding members, radially around its exterior most vertical wall for engaging with an extended J-slot of a wear bushing following the lowering of the retrieving unit into the bushing. Also provided is a pair grooved sections running substantially the length of the mandrel section of the sub-unit on both sides of the mandrel, wherein a an insertion member on the retriever unit is slidably engaged, so that the retriever unit may move along the vertical body, but is disallowed for rotational movement thereupon.
Thus, it is an object of the present invention to provide a retrieving tool which is removably securable on the exterior surface of a sub-unit so that it may be mounted on a string of drill pipe independently of threading on the pipe.
It is a further object of the present invention to provide a retriever apparatus for a wear bushing inside the casing head for allowing vertical movement of the retrieving unit yet allowing rotational movement of the retriever unit during the operation of the apparatus.
It is a further object of the present invention to provide a retriever unit which may be mounted onto a mandrel and connected onto drill pipe and allow a vertical play or movement of the retriever unit in order to prevent damage to the retriever unit or the wear bushing or both due to excessive weight below retriever.
It is still a further object of the present invention to provide a wear bushing retriever apparatus which can be threadably engaged between any two sections of drill pipe without retrieval of the drill bit from the hole.
It is still a further object of the present invention to provide a wear bushing retriever apparatus which is easily removable and installable for quickly removing the wear bushing during the drilling operation.
It is still a further object of the present invention to provide an embodiment of the retriever apparatus to retrieve the bushing by threadably engaging the bushing.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates the disassembled apparatus of the preferred embodiment of the present invention between 2 sections of drill pipe;
FIG. 2 is a side, partial cut-away view of the apparatus of the present invention illustrating the wear bushing in position (phantom) inside the well head, and the wear bushing as retrieved by the apparatus;
FIG. 3 illustrates a side cut-away view of the retriever section of the apparatus of the present invention slidably engaged into the double grooved mandrel portion of the sub-unit section;
FIGS. 4A and 4B illustrate an exploded cut-away side view and top view respectively of the extended J-slot for receiving the retriever unit thereunto.
FIG. 5 illustrates a side view of an additional embodiment of the retriever unit of the apparatus of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIGS. 1 through 4 illustrate the preferred embodiment of the wear bushing retriever section and sub-unit comprising apparatus 10 of the present invention. In the preferred embodiment, apparatus 10 comprises sub-unit 12 having a mandrel section 13, extending the greater length of sub-unit 12. At the first end of sub-unit 12 is enlarged collar section 18, integrally attached to the upper end of mandrel section 13, and at the lower end of mandrel section 13 is removably engaged collar section 20, which is threadably engaged to male portion 21 of mandrel section 13 of sub-unit 12. As is further illustrated in FIG. 1, enlarged collar section 20 has male portion 22 for threadably engaging with a lower section of drill pipe 23. The upper end of sub-unit 12 threadably engages the male end 25 of drill pipe 28. Thus, the sub-unit 12, during operation, as will be discussed further, may be placed between any two sections of drill pipe along the drill string in FIG. 1 represented by pipe sections 23 and 28.
The sub-unit 12, in the preferred embodiment, would have a longitudinal bore 24 therethrough so that the flow of material through the drill string is not obstructed when sub-unit 12 is in position. Also, the exterior diameter of the mandrel section 13 and collars 18 and 20 are equivalent to a section of drill pipe, so that when sub-unit 12 is in place along the drill string, its exterior diameters are no greater than the exterior diameter of the drill string itself.
The complete apparatus 10, as illustrated in FIG. 1, also includes retriever section 26. Retriever section 26 is substantially circular in shape having a bore 27 therethrough for fitting around mandrel section 13. In the preferred embodiment, the interior diameter of bore 27 of retriever section 26 is slightly larger than the exterior diameter of mandrel section 13, so that upon placement of retriever section 26 around mandrel 13, the retriever section 26 is able to slide easily along substantially the entire length of mandrel section 13. This feature is crucial and will be explored more fully further.
In order to position retriever section 26 onto mandrel section 13, lower collar 20 must be removed since the interior diameter of bore 27 of retriever section 26 is substantially less than the exterior diameter of lower collar 20. In fact, in operation, lower collar 20 serves to maintain retriever section 26 along the length of the mandrel section 13, and prevents retriever section 26 from sliding off a lower end of sub-unit 12.
As is illustrated in FIGS. 1 and 3, retriever section 26 comprises upper angular wall portion 30, which integrally attaches to upper vertical wall 31 to form essentially the upper portion of the retriever section 26, which serves as a "cap" or hub portion 29 of retriever section 26. Integrally attached to the shoulder portion 32 of the upper section of retriever section 26 is vertical wall portion 34, which, in operation, would be of sufficient exterior diameter to fit into the interior diameter of a wear bushing during the retrieval or replacement process.
In the preferred embodiment, vertical wall 34 would be adapted with a plurality of protruding members 36, preferably four, which would be equally spaced around the exterior of wall 34, and protruding therefrom as seen in FIGS. 1 and 3. These protrusions 36 serve to engage the wear bushing to be retrieved, as will be discussed further. The lower portion 37 of retriever section 26 serves primarily to guide the retriever section 26 into the opening of the wear bushing to be retrieved.
Also illustrated in FIG. 1, are groove portions 40 and 42 along the exterior surface of mandrel 13. (Groove portion 42 is not shown in FIG. 1 since it is around the far side of the mandrel 13.) Grooves 40 and 42 would extend substantially the entire length of mandrel sections 13. Grooves 40 and 42, as illustrated in exploded in FIG. 3, serve to slidably accommodate insertion members 43 and 44 (illustrated in FIG. 3 in phantom view) located on the inner wall of bore 27 of retriever section 26. Thus, retriever section 26 is free to move vertically along mandrel section 13, yet prevented from freely rotating around mandrel section 13, due to the engagement of insertions 43 and 44 in grooves 40 and 42 respectively. However, with rotation of sub-unit 12, rotation is imparted to retriever section 26 during operation of apparatus 10, said rotation which is critical to the success of the apparatus during operation.
OPERATION OF FLOATING RETRIEVER APPARATUS
During the drilling process, a drill string is comprised of a series of drill pipe sections threadably engaged to one another culminating in the drill bit at the bottom of the hole. The drill string, as illustrated in FIG. 2, by sections 23 and 28 is set within interior casing 52, the upper most end of the casing head 53 which is connected at the well head area 54. Above the well head 54, as further illustrated in FIG. 2, is blow-out preventer stack 58 (shown in partial view), for use in the event of a blow-out in the well. It is through this configuration of connections between the casing head 53 and the well head 54 and blow-out preventer 58, that the string of drill pipe sections 23 and 28 (for example) rotate during the drilling process. It is critical therefore, that the rotation of the drill pipe, which can be at very high RPM's, does not make contact with the surfaces in the well head 54 in order to prevent damage to the well head area. In order to prevent this possible contact, there is positioned a wear bushing or collar 60 as shown in partial phanthom in FIG. 2 and in operating position and in total view after being retrieved. A wear bushing is essentially a metal collar which is seated in that area between the drill pipe 23 and the well head 54, and serves to take the wear as the drill pipe 23 is rotated during the drilling process. As seen in FIG. 2, the construction of wear bushing 60 is an enlarged collar section 62, tapering to a long body section 63. The exterior of the wear bushing undergoes a reduction of diameter at 64 below collar 62, providing a downwardly facing circumferential seat at 65, the length of the wear bushing and the positioning of the seat 65, being such that when the wear bushing 60 has been lowered to its operating position, the seat 65 rests on the head through a bore surface 67, and the collar 62 projects upwardly into the lower end of the bore of the blow-out preventer 58 to protect this region and projects downwardly past the casing head to pipe connection at 71.
Due to the constant rotation of the drill string within the wear bushing 60, the bushing 60 will become worn to a point that replacement is necessary, thus the wear bushing 60 must be retrieved out of its operating position and brought up out of the hole in order to be replaced.
In retrieving wear bushing 60, sections of pipe 23 and 28 would be disassembled as in FIG. 1, so that apparatus 10 could be threadably engaged therebetween. Retriever section would be placed upon mandrel section 13, with insertion members 43 and 44 located on the inner surface of bore 27 of retriever section 26 being slidably engaged into grooves 40 and 42 on mandrel 13 respectively. The lower collar portion 20 of mandrel 13 would then be threadably engaged to the lower end of mandrel 13, and the entire apparatus 10 would then be threadably assembled onto the drill string itself as seen in FIG. 2. Upon placement of the apparatus onto the drill string, the drill string would then be relowered into the hole, until the retriever section makes contact with wear bushing 60, as seen in FIG. 2. As explained earlier, the lower portion of retriever section 26 would fit into that space between the drill pipe 23 and the interior most wall of the collar portion 62 of wear bushing 60.
As is illustrated in FIGS. 4A and 4B, protruding members 36 on the exterior wall of retriever section 26 would align themselves with vertical slots 74 in the wall of the wear bushing 60 and engage therein. Upon positioning of the four protruding members 36 in the respective slots 74, the drill string would then be slightly rotated, thus imparting rotation movement to the sub-unit 13 itself, and due to the engagement of the intruding members 36 in the groove slots of the mandrel sections of sub-unit 13, the retriever section 26 would be likewise rotated. This rotation of the retriever section 26 would in effect slidably engage the protruding members 36 within the horizontal slots 76 of the wall of the wear bushing 60, and thus be in locked position for retrieval of the bushing 60 from the hole. Upon locking in the vertical slots, the drill string would then be "backed up" and the wear bushing retrieved out of the hole. Retrieval is also seen in FIG. 2 as bushing 60 has been retrieved from the hole. The wear bushing 60 would then be rotated a quarter turn in the opposite direction and the protruding members 36 would slip out of the vertical slots 74 and upon disengagement of the apparatus 10 from the drill string, the old worn wear bushing 60 removed, and a new wear bushing 60 would then be manually set upon the retriever section 26 and the process would be repeated except that the wear bushing 60 would then be lowered in the hole for replacement into operating position. As is illustrated in FIGS. 4A and 4B, the horizontal slots 76 could be continuous in the wall of bushing 60 with the exception of stop 78, which, when a protruding member 36 strikes the stop the members 36 are either locked in following clockwise rotation (arrow 88) of the members 36 to be on in position to be slipped out of vertical slots 74 following counterclockwise (arrow 90) rotation of the drill string.
What is critical about the entire operation is shown in the present state of the art as illustrated in U.S. Pat. No. 3,489,214. In the present state of the art, the retriever section would be rigidly engaged upon a section of drill pipe for retrieval of the wear bushing. This rigid connection in the present state of the art, is necessary so that the retriever section will not rotate while the protruding members are being aligned with the vertical slots in the wear bushing itself. However, with this rigid interconnection between the retriever section and the mandrel section of the drill pipe, the retriever section is therefore not free to have any vertical play at all. What results, then is when the retriever section makes contact with the wear bushing, if the protruding members are not properly aligned, the entire weight of the drill string may, and often does, crimp the walls of the wear bushing and, in effect, ruin any chance for retrieval of the bushing in this conventional manner.
With the present invention, the groove sections 40 and 42 in the walls of the mandrel 13, which are engaged by the insertion members 43 and 44 from the interior most wall of the retriever section, serve to allow the retriever section to have approximately 3 feet in vertical play while the protruding members 36 are being aligned with slots 74 of the wear bushing 60, yet having no free rotational movement. Therefore, should a first or second try in aligning the members 36 with slots 74 in the wear bushing 60 not occur, the weight of the drill string would not be imparted onto the wear bushing 60, since the retriever section 26 is free to "float" along the length of the mandrel section 13 of the sub-unit 12. This, in effect, would eliminate the problem of crimping the walls of the wear bushing 60 or damage to the unit itself due to the weight of the drill string imparted upon the rigidly connected retriever section 60 as is in the present state of the art.
FIG. 5 illustrates an additional embodiment of the retriever section 90 of the apparatus 10 in side view. Rather than having the protruding members 36 for slidably engaging with the wear bushing 60, this particular embodiment would have a threaded lower end section 80 which would be adapted to retrieve a particular type of wear bushing, that type of wear bushing having a threaded collar section. Simply, the retriever section 90 would again be lowered into the hole, and upon contact of the retriever section 90 with the wear bushing, the drill string would be rotated and the threaded male end of the retriever section 90 would threadably engage the female end of the wear bushing, and the drill string could then be lifted out of the hole and the wear bushing retrieved in the process. The placement of this embodiment onto the drill string is precisely as described in the preferred embodiment, utilizing sub-unit 12, with the retriever section 90 being slidably attached to mandrel section 13 of sub-unit 12.
Because many varying and different embodiments may be made within the scope of the inventive concept herein taught, and because many modifications may be made in the embodiments herein detailed in accordance with the descriptive requirement of the law, it is to be understood that the details herein are to be interpreted as illustrative and not in a limiting sense. | An apparatus which provides for a sub-body having a mandrel with a longitudinal bore therethrough having a rigidly attached upper collar section for engagement onto a section of pipe or the like, and having a threadably removable lower collar section for threadably engaging the end of a second lower section of drill pipe. Insertable onto the mandrel or body section of the sub-unit is a retriever section, which is substantially circular in nature and slidably movable between the end collars of the sub-unit. The retriever section is adapted with protruding members, radially around its exterior most vertical wall for engaging with an extended J-slot of a wear bushing following the lowering of the retrieving unit into the bushing. Also provided is a pair grooved sections running substantially the length of the mandrel section of the sub-unit on both sides of the mandrel, wherein a intruding member on the retriever unit may move along the vertical body, but is disallowed for rotational movement thereupon. An alternate embodiment would include exterior threads for threadably engaging the wear bushing to be retrieved. | big_patent |
FIELD OF THE INVENTION
The field of this invention is generally downhole vibratory tools and more specifically those tools that selectively allow passage therethrough for other tools.
BACKGROUND OF THE INVENTION
Vibratory tools are used to dislodge a stuck object known as a fish from a downhole location. They have other applications such as allowing a pulling force to be transmitted from the surface to a fish stuck in a deviated wellbore. In that application the vibratory devices can be placed in the deviation such that their presence helps transmit forces to the fish that would have otherwise been resisted by the deviated wellbore through which the string extended to reach the fish. An illustration of such as application is U.S. Pat. No. 6,502,638.
Vibratory tools known in the art have operated on a similar principle. An overpull is applied to the string supporting the tool and pressure is applied within the string. A piston then travels against the bias of a spring, in effect stretching the string while compressing the spring. At some point of travel, the force applied by the spring that acts on a valve member becomes higher than the pressure applied from above to that valve member. When this happens, there is relative movement that takes the valve member off a seat. The pressure that had been keeping the valve member on the seat up to that point is suddenly relieved as the valve member is biased off the seat by the rising spring force due to compression of the spring. Once the valve member is off the seat, the pressure acting on the piston that drove the mandrel down against the spring in the first place is suddenly relieved. Flow through the tool causes a sudden drop in the applied pressure causing the piston to snap back under the spring force and re-close the valve. At that point the cycle repeats. There are variations on this basic concept. Some designs employ a piston or opposed pistons that drive the mandrel in opposed directions.
There are other common features of known designs that limit their utility. Most earlier designs did not have a capability to have a central passageway clear so that a wireline could be run through the tool to determine conditions in the vicinity of the fish. Using those designs, the vibratory tool had to be removed to run a wireline or other tools down to the fish. Most all of these designs had the dump valve that relieved pressure located in the center of the tool preventing a clear run through the tool for a wireline or other tools. A few examples of such designs are U.S. Pat. Nos. 6,062,324 and 6,206,101.
More recently a drop in dart that incorporates the working components of the vibratory tool has been developed as shown in U.S. Pat. No. 6,866,104. This patent offered a solution to the need to have wireline access through the tool body and the dart could be retrieved after the vibration operation that commenced with the landing of the dart and application of pressure. While this design allowed for wireline access through the tool it also included additional compromises unique to the design of a dart that landed and sealed around a seat downhole. The main area of compromise was that the components of the vibratory tool had to be made to fit in the dart and the dart was limited in outside diameter so that it could fit into the receptacle in the tool body. Doing this required miniaturization of the vibratory tool key components which limited the power delivery of the generated vibrations from the tool. The use of smaller components also increased the effects of fatigue on the moving parts of the vibratory tool and there were also many components to the dart assembly making it fairly costly to build and maintain.
Other issues that affected reliable operation in the previous designs included a dump valve assembly that was pounded against a seat with each cycle resulting in rapid wear and potential loss of sealing contact. Another problem in the past had been the limited power delivery from the driving piston since its area was limited by the maximum available inside diameter in the tool housing. Many applications simply needed a higher power delivery to get the fish released.
A few other examples of known designs for vibratory tools are U.S. Pat. Nos. 6,474,421; 6,182,775; 6,164,393; 5,875,842 and 5,375,671.
What is needed and is addressed by the tool described below is a collection of features that solve the issues with prior design and lead to a more economical and reliable design. The dump valve is reconfigured into an annular shape to keep the middle of the tool free and clear. This allows a central passage to exist to permit a wireline operation through the tool when the tool is not set up to be in vibratory mode. The tool can be simply put in vibratory mode by dropping a removable plug onto a seat. The dump valve opens and closes without getting slammed against a seat. The mandrel is powered by stacked pistons in the tool body to magnify the delivered power from the vibratory tool. Since the essential parts of the vibratory tool are in the housing and only the delivery of the plug is required to initiate operations, the remaining components can be designed to be more beefy so as to run longer and more reliably as compared to the prior design where the key movable components were delivered into the tool housing on a dart. The tool can be configured so that the pistons can travel their entire stroke without being banged against travel stops. The tool has the capability to tolerate continued downward mandrel movement to dissipate its momentum even after the dump valve opens. The components are then configured to apply power to the mandrel for a down cycle when the dump valve closes close to the point where the pistons reach their upward travel limit. In this way a longer power stroke is achieved in an effort to free the fish. The tool can be run to apply up oscillating forces with or without impacts depending on how the tool is operated by rig personnel. These and other advantages of the present invention and its scope will become more apparent to those skilled in the art from a review of the description of the preferred embodiment, the drawings and the claims appended below.
SUMMARY OF THE INVENTION
A vibratory tool for downhole use is capable of letting a wireline or other tools pass a passage therethrough that can be subsequently closed by landing a plug on a seat. The dump valve is disposed annularly about the central passage so that cycling the tool does not cause it to be slammed against a seat. Since only a plug is delivered to a passage the functioning parts already in the housing are made stronger to improve reliability. Additional power is delivered per stroke from modular stacked piston units. The tool can be run in a manner where the high amplitude low frequency oscillating forces are delivered to the stuck fish without impacts of the pistons on the housing.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a section view of the tool with the plug in place and ready to vibrate;
FIG. 2 is a section view of the modular piston stack that can be used in the tool;
FIG. 3 is a section view of the lower end of the tool without the plug in position;
FIG. 4 is the view of FIG. 3 with the plug seated and pressure being applied;
FIG. 5 is the view of FIG. 4 just before the dump valve opens;
FIG. 6 is the view of FIG. 5 as the dump valve trips open;
FIG. 7 is the view of FIG. 6 after sufficient uphole movement of the mandrel to close the dump valve again and repeat the cycle.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The tool has an outer body 20 with a lower end 22 that is attached to a stuck object or fish 24 . The outer body 20 has an upper end 26 . Within the outer body 20 and extending uphole from upper end 26 is the mandrel 28 . Mandrel 28 is connected to the surface through a string 30 . Mandrel 28 has a passage 32 that is in fluid communication with the passage in the string 30 so that pressure can be delivered from the surface to lateral ports such as 34 or 36 . Ports 34 and 36 are at different elevations. Although only two rows of such ports are illustrated in the preferred embodiment, the construction of the tool is preferably modular so that different numbers of rows of ports can be used. A row of ports such as 34 lead to an annular space 38 with which there is communication to a piston 40 that is attached to the mandrel 28 . Pressure in space 38 pushed down piston 40 and with it mandrel 28 at the same time displacing fluid from chamber 42 through opening 44 . FIG. 2 shows that this type of piston arrangement is modular allowing as many or as few pistons such as 40 to be stacked. More pistons such as 40 connected to the mandrel 28 mean more force imparted in a downward direction on the string 30 while at the same time creating an opposite reaction force on the outer body 20 that is attached to the fish 24 . It should be noted that space 38 and chamber 42 are created between mandrel 28 and outer body 20 . Chamber 42 sees downhole pressures through opening 44 . Stacking pistons 40 in effect increases the area of total pistons exposed to the applied pressure thus increasing the delivered power of the tool to considerably more by orders of magnitude than had been available in prior art tools.
Referring now to FIG. 4 , the mandrel 28 has a lower end 9 that marks the end of passage 32 and a nearby shoulder 46 . A drop in plug 16 is shown landed on shoulder 46 to close off passage 32 . Those skilled in the art will appreciate that before plug 16 is dropped the passage 32 is open, as shown in FIG. 3 , so that a wireline or other tool can be run through passage 32 and into the stuck fish or further down to collect any required data that may be helpful in determining the progress of the operation trying to get the fish unstuck or for any other reasons. The plug 16 is preferably retrievable and for that purpose has a fishing neck 48 so that it can be captured and returned to the surface with known tools. Plug 16 also has a seal 50 to help close off passage 32 and build pressure in it. Lower end 9 features openings 52 that lead into chamber 54 . Dump valve 12 is shown closing off chamber 54 so that application of pressure to passage 32 will build pressure on piston(s) 40 to move the mandrel 28 downwardly. It should be noted that valve 12 is cylindrically shaped with a seal ring 11 initially riding on surface 56 to hold pressure in chamber 54 as the movement of the mandrel 28 stretches out string 30 that is connected to it. At some point the ring seal 11 moves off of surface 56 to surface 58 that represents an increase in inside diameter and as a result a loss of sealing contact that had previously closed off passage 32 . For a time the pressure in passage 32 drives the valve 12 in tandem with the mandrel 28 due to applied pressure in chamber 54 from ports 52 . The movement of valve 12 is against the bias of spring 14 bearing on spring stop 13 . At some point of pressure buildup in passage 32 and tandem movement of mandrel 28 and valve 12 the force of spring 14 on stop 13 exceeds the downward force on valve 12 from pressure in passage 32 . This results in the valve 12 being moved uphole with respect to the mandrel 28 to relieve the pressure built up in the passage 32 . This happens due to ring seal 11 now being placed in juxtaposition with surface 58 of valve 12 , breaking the seal, as shown in FIG. 5 . The mandrel 28 continues to move downhole due to momentum from the extension force applied from the pressure with the passage 32 closed off at the bottom and piston(s) 40 forcing the mandrel 28 down. However, the valve 12 in the open position and the pressure in passage 32 dissipated the momentum of mandrel 28 carrying it further downhole quickly dissipates as it reaches its lowest position shown in FIG. 6 .
With the pressure dissipated in passage 32 the stretching of the string 30 that accompanied the downhole movement of the mandrel 28 now reverses as the string 30 , now no longer exposed to a stretching force goes into a contraction cycle. With the fish 24 still stuck and holding the outer housing 20 in position, the mandrel 28 and the piston(s) 40 attached to it move up relative to the housing 20 . At some point preferably before the piston(s) 40 slams into a radial surface in chamber 38 the seal ring 11 gets back into sealing contact with surface 56 of valve 12 closing off passage 32 again to allow pressure buildup and to reverse the direction of movement of mandrel 28 to allow the next cycle to begin, as shown in FIG. 7 . It should be noted that the tool can be operated so that there are jarring blows delivered in every cycle or by avoiding such jarring blows. The factor that controls this is the amount of surface overpull applied to string 30 before and during when passage 32 is pressurized.
The basic operation of the tool having been reviewed, the features of the tool of the present invention can now be explored in greater detail. One such feature is the ability to stack pistons 40 to increase the available piston area in a confined downhole space so as to increase the power of the pressure spike that is applied to the fish 24 . The impacting of pistons 40 on the housing 20 is optional and depends of the applied overpull to string 30 . The cycling continues until applied pressure is turned off, the overpull force is removed from the surface or by the fish 24 becoming unstuck. It should be noted that without plug 16 in position, the tool can't cycle but wireline and other operations are possible through passage 32 . The tool is activated by dropping a simple and cheap plug 16 into passage 32 to seal its lower end. The design of the valve 12 as an annular ring gets it out of the center of the tool to allow the wireline access feature through passage 32 before the plug 16 is dropped. It further allows the opening and closing of the valve 12 to occur without slamming any part of the valve against a seat, as in some prior designs. Instead, the ring seal 11 simply slides between surfaces 56 and 58 respectively to close and open the valve. The configuration of the valve 12 and the spring 14 about the central bore of the tool allows those components to be designed to better perform in a cyclical loading environment without fatigue or failure. It also takes away the need, as in the prior art to put all the workings of the tool in a dart that is seated in the tool body after a wireline operation below the tool body. Instead, the components of the tool are delivered within the body and still are configured to leave a passage open for wireline or other activity through the passage 32 before the plug 16 is dropped into position. This means that the components delivered with the tool initially can be bigger than they could have been as part of a dart and will give longer trouble free service. It also means that the plug 16 is simple and cheap because it has no moving parts. Additionally, the tool can be made to operate with fewer moving parts than the previous design that involved dropping the critical tool components as part of the dart assembly.
The design of valve 12 eliminates significant cyclical impacts on opening and closing due to the cylindrical shape and the seal ring 11 simply moving into alignment and misalignment with the surface that surrounds it. The use of a cylindrically shaped valve 12 allows for the spring 14 to be more beefy thus reducing the stresses on it and extending its life.
The modular design that allows selection of the number of pistons allows for a tool design to be matched to the power required for the particular work string, or the surface equipment available or the anticipated downhole conditions with the stuck fish. Presenting the valve 12 outside the mandrel 28 and the piston(s) 40 opens the center and allows the use of the simple plug 16 . Wear on the valve is eliminated by avoiding banging valve components on a valve seat. Special materials can also be used for seal ring 11 to increase resistance to wear. The layout of the components allows the mandrel 28 to continue moving downhole after valve 12 opens. The result is that forces created in the modular piston 40 assembly stay in phase with the oscillating string 30 or the fish 24 . This is accomplished by engaging the power stroke near the upper end of piston movement, after valve 12 opens, and before valve 12 is allowed to close again. In that manner if the momentum from the string 30 allows for a longer stroke the tool can accommodate that by not engaging the power stroke until the pistons are at or near their maximum uphole travel. On the other hand the tool can also be operated to have impacts on each cycle with the pistons 40 against the housing 20 . These impacts can be on the up or down stroke and can be induced during operation by varying the overpull amount. The tool can operate without impact of the pistons 40 and can still be effective in releasing a fish 24 . The tool may also be used in stimulation or fishing operations. It provides large amplitude vibrations in a tubing string. It relies on a single valve for operation.
The tool can also have a rotational lock between the mandrel 28 and the housing 20 for the purposes of torque transmission.
It is to be understood that this disclosure is merely illustrative of the presently preferred embodiments of the invention and that no limitations are intended other than as described in the appended claims. | A vibratory tool for downhole use is capable of letting a wireline or other tools pass a passage therethrough that can be subsequently closed by landing a plug on a seat. The dump valve is disposed annularly about the central passage so that cycling the tool does not cause it to be slammed against a seat. Since only a plug is delivered to a passage the functioning parts already in the housing are made stronger to improve reliability. Additional power is delivered per stroke from modular stacked piston units. The tool can be run in a manner where the high amplitude low frequency oscillating forces are delivered to the stuck fish without impacts of the pistons on the housing. | big_patent |
FIELD OF THE INVENTION
[0001] The present invention pertains generally to retaining walls. Specifically, the invention relates to an apparatus and method of installation for a completely precast concrete retaining wall of the type typically used alongside highways and railways.
BACKGROUND OF THE INVENTION
[0002] Various retaining wall systems have been developed for use in retaining soil on an embankment. In a conventional retaining wall design, one of the major design criteria that must be considered is the pressure exerted on the foundation at the front of the base (toe) of the retaining wall system. This becomes particularly limiting in tall vertical walls with sloping backfill. Conventionally designed cantilevered walls reduce the pressure at the toe by providing a lever arm perpendicular to and behind the wall face upon which the vertical load of the backfill acts, creating a moment opposite in direction to the moment due to the horizontal force of the backfill material on the wall face. This moment is increased for design purposes by increasing the area of the cantilever arm subject to the vertical loads by increasing the size or length of the moment arm until a suitable toe pressure is reached and a suitable factor of safety against overturning is reached.
[0003] Many different schemes for increasing the opposing moment force, i.e., the vertical force on the lever arm, have been employed and are well known in the art. Some ways that the industry has tried to oppose the moment force are through using a gravity wall, piling wall, mechanically stabilized earth wall, cantilever wall or an anchored wall. FIGS. 1 and 2 show examples of a prior art retaining wall.
[0004] A major disadvantage of the prior art is that many of the tieback elements, including straps, anchors, and/or stems, must extend too far behind the face to engage the wall panels in order to produce a margin of safety which is sufficient to overcome the overturning moment. In these situations, there is frequently insufficient room to introduce stabilizing members of adequate length between the front of the wall and the stable earth or rock mass created by excavation. Consequently, a considerable cut must be made into the soil behind the retaining wall in comparison to the height of the soil retained for conventional static, leverage retaining wall systems in order to meet suitable margins of safety. This design constraint effectively limits the height of a wall to single tiers 10 to 12 feet high.
[0005] Cast-in-place cantilever retaining walls are a proven method of retaining earth. These retaining walls typically consist of a vertical wall on top of a horizontal base. These walls work by utilizing the same soil they are retaining at the face of the wall to also anchor the base below. The walls are very commonly designed for up to approximately twenty feet tall retained earth, which is the height difference from the high elevation to the low elevation. For walls over twenty feet, one way to keep the sections from getting too massive is to utilize counterforts. Counterforts are also vertical but perpendicular to the face extending at an angle from the top of face to the base.
[0006] While counterforts have been a great innovation to the industry, a disadvantage of prior art counterforts is that they can require special forming and labor which can be expensive when performed on site. Inside a plant, the sections can be pre-manufactured in a controlled environment at less cost. There is prior art that consists of a face with counterforts, but it still relies on a final pour on-site to fill a base shell which is substantially open. This cast-in-place base can take a significant amount of time to cure and can be costly to form and place the rebar in situ. These prior art retaining walls also require labor intensive temporary shoring to hold the face upright until the cast-in-place base has cured.
[0007] Another prior art product has a precast base and precast wall, but fails to include a counterfort for support. This is disadvantageous as the wall heights grow, since the lever arm to resist the overturning moment is confined within the planes of the base and face. Not only does this lead to unpractical, inefficient reinforcement design and panel thickness, but it requires a large number of expensive and labor intensive mechanical splice sleeve connections at the critical juncture between the face and base. Another disadvantage to not having a counterfort is that the wall needs to be temporarily braced during installation, which adds both cost and time.
[0008] There is also prior art of pre-manufactured upside-down, T-shaped retaining walls with small scale counterfort ribs. The disadvantage of these walls is that they require specific foams and therefore are not customizable. Also their installation allows for less flexibility due to the fixed connection between the base and face of these T-shaped retaining walls. Further, due to how this system needs to be formed, it makes it difficult to add textured aesthetics to the face of the wall. This system is also limited in retained height due to the challenge of handling such a large, one-piece unit. At a certain height, these retaining walls are also limited in size due to shipping limitations.
SUMMARY OF THE INVENTION
[0009] The present invention provides an apparatus and method for constructing a retaining wall which allows for taller walls and shorter bases by pre-manufacturing parts of the wall to be transported to and assembled at the site. Using pre-manufactured assembly components will save both on installation and transportation costs. Generally, a precast, substantially solid, rectangular or trapezoidal base is set on grade at the job site, and a face panel with an integral counterfort is set upright on the base with a connection joining them together. Temporary shoring is not required with this assembly. As soon as the face panel and counterfort are set on the base, it can withstand temporary wind loads immediately. The invention is also flexible in that the height or width of any of the individual components can vary over a wide range. All of the pieces of the assembly can easily be made to custom sizes.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] In describing the prior art and preferred or illustrative embodiments, reference is made to the accompanying drawings. It should be understood, however, that the application is not limited to the precise arrangements and instrumentalities shown therein:
[0011] FIG. 1 represents a perspective view of a prior art retaining wall.
[0012] FIG. 2 represents a perspective view of a prior art retaining wall.
[0013] FIG. 3 represents a perspective view of a retaining wall comprising a first embodiment of the present invention.
[0014] FIG. 4 represents a plan view of the embodiment of FIG. 3 .
[0015] FIG. 5 represents a front elevation view of the embodiment of FIG. 3 .
[0016] FIG. 6 represents a right elevation view of the embodiment of FIG. 3 .
[0017] FIG. 7 represents a close-up view of a connection between a base and face panel with an exposed end of rebar fixed into an opening in a base with grout.
[0018] FIG. 8 a represents a plan view of a retaining wall comprising a second embodiment of the present invention using H-Piles beneath the base.
[0019] FIG. 8 b represents a front view of a retaining wall comprising a second embodiment of the present invention using H-Piles beneath the base.
[0020] FIG. 8 c represents a right side view of a retaining wall comprising a second embodiment of the present invention using H-Piles beneath the base.
[0021] FIG. 8 d represents a perspective view of a retaining wall comprising a second embodiment of the present invention using H-Piles beneath the base.
[0022] FIG. 9 a represents a plan view of a retaining wall comprising a third embodiment of the present invention using H-Piles beneath a pocket in the base.
[0023] FIG. 9 b represents a front view of a retaining wall comprising a third embodiment of the present invention using H-Piles beneath a pocket in the base.
[0024] FIG. 9 c represents a right side view of a retaining wall comprising a third embodiment of the present invention using H-Piles beneath a pocket in the base.
[0025] FIG. 9 d represents a perspective view of a retaining wall comprising a third embodiment of the present invention using H-Piles beneath a pocket in the base.
[0026] FIG. 10 a represents a plan view of a retaining wall comprising a fourth embodiment of the present invention using a barrier located on top of the face panel.
[0027] FIG. 10 b represents a front view of a retaining wall comprising a fourth embodiment of the present invention using a barrier located on top of the face panel.
[0028] FIG. 10 c represents a right side view of a retaining wall comprising a fourth embodiment of the present invention using a barrier located on top of the face panel.
[0029] FIG. 10 d represents a perspective view of a retaining wall comprising a fourth embodiment of the present invention using a barrier located on top of the face panel.
[0030] FIG. 11 a represents a plan view of a retaining wall comprising a fifth embodiment of the present invention using a barrier located on the rear side of the face panel.
[0031] FIG. 11 b represents a front view of a retaining wall comprising a fifth embodiment of the present invention using a barrier located on the rear side of the face panel.
[0032] FIG. 11 c represents a right side view of a retaining wall comprising a fifth embodiment of the present invention using a barrier located on the rear side of the face panel.
[0033] FIG. 11 d represents a perspective view of a retaining wall comprising a fifth embodiment of the present invention using a barrier located on the rear side of the face panel.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0034] While embodiments of this invention can take many different forms, specific embodiments thereof are shown in the drawings and will be described herein in detail with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention, and is not intended to limit the invention to the specific embodiment illustrated.
[0035] Referring to the drawings in detail, wherein like numerals indicate like elements throughout, there is shown in FIGS. 3-7 a preferred embodiment of a retaining wall in accordance with the various aspects of present invention. While retaining wall systems are commonly used in retaining soil, it should be understood that the present invention can be used in many different applications including retaining other materials such as sand, pebbles or rocks.
[0036] FIG. 3 illustrates a perspective view of an embodiment of wall 10 embodying principles of the present invention. The retaining wall 10 of the present invention is made of precast concrete in two discrete, modular parts.
[0037] Wall 10 comprises a precast concrete face panel 12 with an integral counterfort piece 14 and a precast base piece 16 . A first precast modular part 11 is a generally flat front face panel 12 with an integral counterfort 14 extending from the rear side of the panel 18 . The face panel is typically not completely “flat” because it has surface ornamentation so that for example it appears to be a stone or brick or other ornamentation wall. The panel 12 can have a common height of twenty feet. The counterfort 14 which extends from the rear side of the panel 18 is unitary with the face panel 12 . The face panel 12 will preferably have at least two counterforts 14 spaced apart evenly from ends of the face 12 . The counterfort 14 has a flat bottom, so that in side view, the counterfort 14 is generally a right triangle. However, it should be understood that many different embodiments of the shape of the counterfort have been envisioned. For instance, when viewed from the side, the counterfort 14 could be a generally rectangular shape or be made of a shape that is generally rectangular and then transitions to a triangular shape. Many different combinations are claimed and disclosed herein. A side view of an embodiment of the retaining wall 10 is shown in FIG. 6 .
[0038] Unless the wall is designed to retain water, it is important to have proper drainage behind the wall in order to limit the pressure to the wall's design value. Therefore an opening for drainage is preferably provided or the wall can be constructed using the dry stone building method so that the wall can be self-draining. Drainage materials will reduce or eliminate the hydrostatic pressure and improve the stability of the material behind the wall. Therefore, as seen in FIG. 6 , the counterfort 14 may also have an opening 20 for drainage near the bottom front corner of the counterfort 14 . Face panel 12 may also have a weep hole for drainage towards the bottom.
[0039] The front face panel 12 may have more than one counterfort 14 providing support. The counterfort 14 extends perpendicularly from the face panel 12 , and its base extends rearward (illustratively thirteen feet). The top of the “triangle” may be squared off to have a horizontal top ledge (illustratively of six inches), with a bottom edge (illustratively of ten feet). The bottom edge may also be squared off.
[0040] Reinforcing bars (rebar) 22 can be cast within the counterfort 14 . Preferably, there will be more longitudinal, approximately vertical steel reinforcements incorporated in the lower part of the counterfort securing that part of the wall 10 where overturning forces are greatest. Furthermore, such rebars 22 are preferably in greater concentration at the rear of the counterfort 14 where they can best resist tensile forces, although reinforcements will normally also run approximately vertically at intermediate positions nearer the facing panel 12 . Rebars can also be added within the base 16 for additional strength.
[0041] These rebars 22 act as a tensioning device within the concrete helping to meet design loads. In one embodiment, the rebars 22 extend through the bottom of the counterfort 14 . The rebars 22 can also terminate in an “L” or “backwards L” configuration. This helps the exposed portions of the rebars 22 act as anchors. Another option is to utilize a forged foot 24 at the free end, where the bar (illustratively one inch diameter) terminates in a horizontal disk (illustratively two and a half inch diameter). However, it should be understood that the rebar 22 can terminate in a number of differing configurations.
[0042] A second precast modular part 15 comprises a base 16 which is illustratively one foot thick. The base 16 is generally a rectangular or trapezoidal shaped platform and typically is set on grade. Because the base 16 is a platform, it is generally solid with no substantial openings other than small openings for grout fill. The base 16 is precast concrete and therefore does not require that the base 16 be cast in-situ at the construction site.
[0043] In one embodiment, a shear key 26 can be made between the face 12 or counterforts 14 and the base 16 . This shear key can be a depression in the base 16 and sized to accept the bottom 30 of the front face panel 12 . Once the bottom 30 of the face 12 is set into place, the voids between the shear key 26 and bottom 30 of the face panel 12 can be filled with grout to solidify the connection.
[0044] A shear key 26 can also extend down from the base 16 into the ground. This could be a pre-manufactured shear key or there can be exposed rebar extending down from the base 16 to be later poured with concrete in the field. In another embodiment, the base 16 can be precast with a front lip which protrudes from the end of the base 16 near the face panel 12 .
[0045] In one embodiment, the base 16 has at least one opening 32 sized to accept the downward-extending rebar 22 ends from the counterfort 14 . This opening 32 can be sized to accept more than one rebar 22 end. In a preferred embodiment, the base has a single row or multiple rows of openings 32 , illustratively four and a half inches in diameter, to receive multiple downward-extending rebar 22 ends from the counterfort 14 . This connection point between the counterfort 14 and base 16 is shown more closely in FIG. 5 . As shown in this Figure, rebar 22 can terminate in forged foot anchor 24 .
[0046] The connection between the first module 11 and second module 15 is made by inserting an end of a piece of rebar of one module into an opening in the other module and then sealing the connection with grout. For the purposes of this disclosure, a method of connecting the modules will be described where the first module has protruding rebar and the second module has openings. However, it should be understood to one of ordinary skill in the art that the connection described herein can be reversed with the second module 15 having rebar extending from its top surface and connecting with openings within the bottom surface of the first module 11 .
[0047] To connect the first module 11 and second module 15 , an installer would place the second module 15 into a substantially horizontal position. The installer would then raise the first module 11 above the second module 15 and align the exposed ends of the rebars 22 of the first module 11 with the openings 32 on the second module 15 . The installer would then lower the first module 11 on top of the second module 15 such that the exposed ends of the rebar 22 of the selected first module are placed within the openings in the second module. One advantage of this arrangement is that once the first module 11 is placed on the second module 15 , no temporary shoring is required to hold the face upright until the grout connection between the first module 11 and second module 15 has cured.
[0048] By lowering the first module 11 onto the second module 15 , the anchor 24 is simultaneously lowered into an opening 32 in the base 16 . This opening 32 can be a straight cylindrical shape, tapered or formed using a corrugated pipe. It can extend partially or all the way through the base 16 . It shall be understood that those of ordinary skill in the art can use a number of different sizes and shapes for the opening 32 . Before the first module 11 is completely set on the second module 15 , an installer can use one or more shims 36 to make the front face panel 12 plumb in both the vertical and horizontal directions. An installer can also use shims 36 to rotate the face 12 to any desired angle.
[0049] Once the installer has installed the shims 36 and is satisfied with the placement of the first 11 and second modules 15 , the anchor 24 can finally be set into the opening 32 . The shims 36 elevate the first module 11 above the second module 15 enough so that an installer can pump a high strength grout 34 into the opening 32 . This high strength grout 34 fills the void remaining in the opening 32 and bonds itself to the concrete base 16 and the anchor 24 . This results in a shear cone in the base to resist the pullout of the rebar 22 , ultimately connecting the two precast modular pieces 11 , 15 . Once the face 12 and counterfort 14 are connected to the base 16 with grout 34 , the connection is complete. An installer can then backfill the area behind the retaining wall 10 .
[0050] In a typical installation, multiple retaining walls 10 are placed adjacent to one another to form a continuous wall. To allow for flexibility between adjacent walls 10 , an installer can place a shear key or use ship laps between adjacent modules. This interface between adjacent walls can either be grouted or not grouted. A product such as butyl mastic joint sealant or wrap can also be used to seal the vertical joint between adjacent faces 12 .
[0051] If circumstances require extra precautions to keep the base 16 from sliding once it is backfilled and any surcharge loads are applied, several measures can be taken. One option is that the bottom of the base 16 can be textured or roughened to increase friction between the base 16 and subsurface ground beneath the base. An alternative is that the base 16 can be set on shims and have various holes or ports 38 in the base 16 so that flow-able grout can be pumped through the base 16 and into the void created by the shims underneath. This grout will serve to increase the frictional force between the base 16 and subsurface.
[0052] If there are poor soil conditions under the base, then H-piles 40 can be driven into the ground and the base 16 set on top of these piles 40 for added stability. FIG. 8 shows an embodiment of the present invention with piles 40 driven into the earth underneath the base 16 . If desired, a pocket 42 can be created in the base 16 to allow the pile 40 to extend up into the base 16 and then the connection can be filled with grout. FIG. 9 shows images of pocket 42 formed in base 16 . Alternatively, the piles 40 could extend up into the grouted area between the subsurface and the base 16 and then this void would be filled with grout. Still a fourth alternative method would be to utilize a cast-in-place pile cap which can be poured prior to setting the base 16 . This pile cap is typically a thick concrete mat that rests on concrete, steel or timber piles that are driven into the unstable ground to provide a suitable stable foundation.
[0053] In another embodiment, a vehicle impact barrier 44 can be formed and cast-in-place on top of the wall 10 or behind the wall 10 . FIG. 10 shows an embodiment of the retaining wall 10 with a vehicle impact barrier 44 attached on top of the wall 10 . FIG. 11 shows an alternative embodiment of the retaining wall 10 with a vehicle impact barrier 44 attached to the rear side of the panel 18 . To create a cast-in-place impact barrier, will use a face panel 12 that has exposed rebar extending out of the face 12 . This rebar will extend vertically out of the top surface of the face panel 12 if a user wishes to have the impact barrier 44 formed on top of the face 12 . However if a user prefers that the impact barrier 44 be formed on a rear surface 18 of the face 12 , then the rebar will extend horizontally out of the rear surface 18 . In either scenario, an installer can cast an impact barrier 44 around the exposed rebar to form the cast-in-place barrier 44 at the desired location. Another embodiment of this impact barrier eliminates the need for in situ casting because a pre-manufactured, pre-cast barrier can also be formed integrally with the face 12 at the factory. The pre-cast concrete barrier can be precast in a number of different desired locations. However, in a preferred embodiment, the pre-cast concrete barrier is located on top of the face 12 .
[0054] All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.
[0055] Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.
[0056] The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed. | A retaining wall comprises a precast concrete face panel with integral counterfort connected to the rear of the facing and a precast concrete base supporting the facing and the counterfort. The counterfort comprises a reinforced concrete slab having a substantially vertical front portion at a substantially right angle to a base portion, and a rear portion running from substantially the top of the counterfort to the rear of the base portion thereof. The face and counterfort module is connected to the base module through the use of rebar and openings which are fixedly attached together using a high strength group. | big_patent |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to systems and methods for producing or delivering heat at or near the down hole end of production tubing of a producing oil or gas well for improving production therefrom.
[0003] 2. Background Information
[0004] Free-flowing oil is increasingly difficult to find, even in oil wells that once had very good flow. In some cases, good flowing wells simply “clog up” with paraffin. In other cases, the oil itself in a given formation is of a viscosity that it simply will not flow (or will flow very slowly) under naturally ambient temperatures.
[0005] Because the viscosity of oil and paraffin have an inverse relationship to their temperatures, the solution to non-flowing or slow flowing oil wells would seem fairly straight forward—somehow heat the oil and/or paraffin. However, effectively achieving this objective has proven elusive for many years.
[0006] In the context of gas wells, another phenomena—the buildup of iron oxides and other residues that can obstruct the free flow of gas through the perforations, through the tubing, or both—creates a need for effective down hole heating.
[0007] Down hole heating systems or components for oil and gas wells are known (hereafter, for the sake of brevity, most wells will simply be referred to as “oil wells” with the understanding that certain applications will apply equally well to gas wells). In addition, certain treatments (including “hot oil treatments”) for unclogging no-flow or slow-flow oil wells have long been in use. For a variety of reasons, the existing technologies are very much lacking in efficacy and/or long-term reliability.
[0008] The present invention addresses two primary shortcomings that the inventor has found in conventional approaches to heating oil and paraffin down hole: (1) the heat is not properly focused where it needs to be; and (2) existing down hole heaters fail for lack of design elements which would protect electrical components from chemical or physical attack while in position.
[0009] The present inventor has discovered that existing down hole heaters inevitably fail because their designers do not take into consideration the intense pressures to which the units will be exposed when installed. Such pressure will force liquids (including highly conductive salt water) past the casings of conventional heating units and cause electrical shorts and corrosion. Designers with whom the present inventor has discussed heater failures have uniformly failed to recognize the root cause of the problem—lack of adequate protection for the heating elements and their electrical connections. The down hole heating unit of the present invention addresses this shortcoming of conventional heating units.
[0010] Research into the present design also reveals that designers of existing heaters and installations have overlooked crucial features of any effective down hole heater system: (1) it must focus heat in such a way that the production zone of the formation itself is heated; and (2) heat (and with it, effectiveness) must not be lost for failure to insulate heating elements from up hole components which will “draw” heat away from the crucial zones by conduction.
[0011] However subtle the distinctions between the present design and those of the prior art might at first appear, actual field applications of the present down hole heating system have yielded oil well flow rate increases which are multiples of those realized through use of presently available down hole heating systems. The monetary motivations for solving slow-flow or no-flow oil well conditions are such that, if modifying existing heating units to achieve the present design were obvious, producers would not have spent millions of dollars on ineffective down hole treatments and heating systems (which they have done), nor lost millions of dollars in production for lack of the solutions to long-felt problems that the present invention provides (which they have also done).
SUMMARY OF THE INVENTION
[0012] It is an object of the present invention to provide an improved down hole heating system for use in conditioning oil and gas wells for increased flow, when such flow is impeded because of viscosity and/or paraffin blockage conditions.
[0013] It is another object of the present invention to provide an improved design for down hole heating systems which has the effect of more effectively focusing heat where it is most efficacious in improving oil or gas flow in circumstances when such flow is impeded because of oil viscosity and/or paraffin blockage conditions.
[0014] It is another object of the present invention to provide an improved design for down hole heating systems for oil and gas wells which design renders the heating unit useful for extended periods of time without interruption for costly repairs because of damage or electrical shorting caused by unit invasion by down hole fluids.
[0015] It is another object of the present invention to provide an improved method for down hole heating of oil and gas wells for increasing flow, when such flow is impeded because of viscosity and/or paraffin blockage conditions.
[0016] In satisfaction of these and related objects, the present invention provides a down hole heating system for use with oil and gas wells which exhibit less than optimally achievable flow rates because of high oil viscosity and/or blockage by paraffin (or similar meltable petroleum byproducts). The system of the present invention, and the method of use thereof, provides two primary benefits: (1) the involved heating unit is designed to overcome an unrecognized problem which leads to frequent failure of prior art heating units—unit invasion by down hole heating units with resulting physical damage and/or electrical shortages; and (2) the system is designed to focus and contain heat in the production zone to promote flow to, and not just within, the production tubing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] [0017]FIG. 1 is an elevational view of a producing oil well with the components of the present down hole heating system installed.
[0018] [0018]FIG. 2 is an elevational, sagittal cross section view of the heating unit of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0019] Referring to FIG. 1, the complete down hole heating system of the present invention is generally identified by the reference numeral 10 . System 10 includes production tubing 12 (the length of which depends, of course, on the depth of the well), a heat insulating packer 14 , perforated tubing 16 , a stainless steel tubing collar 18 , and a heating unit 20 .
[0020] Referring in combination to FIGS. 1 and 2, heating unit 20 includes electrical resistance type heater rods 26 , the electrical current for which is supplied by cables 22 which run down the exterior of production tubing 12 and connect to leads 24 at the upper end of heating unit 20 .
[0021] Heat insulating packer 14 and stainless steel collars 18 are includes in their stated form for “containing” the heat from heating unit 20 within the desired zone to the greatest practical degree. Were it not for these components, the heat from heating unit 20 would (like the heat from conventional down hole heater units) convect and conduct upward in the well bore and through the production tubing, thereby essentially directing much of the heat away from the area which it is most needed—the production zone.
[0022] Perhaps, it goes without saying that oil that never reaches the pump will never be produced. However, this truism seems to have escaped designers of previous down-hole heating schemes, the use of which essentially heats oil only as it enters the production tubing, without effectively heating it so that it will reach the production tubing in the first place. Largely containing the heat below the level of the junction between the production tubing 12 and the perforated tubing 16 , as is achieved through the current design, has the effect of focusing the heat on the production formation itself. This, in turn, heats oil and paraffin in situ and allows it to flow to the well bore for pumping, thus “producing” first the viscous materials which are impeding flow, and then the desired product of the well (oil or gas). Stainless steel is chosen as the material for the juncture collars at and below the joinder of production tubing 12 and perforate tubing 16 because of its limited heat conductive properties.
[0023] Physical and chemical attack of the electrical connections between the power leads and the heater rods of conventional heating systems, as well as shorting of electrical circuits because of invasion of heater units by conductive fluids is another problem of the present art to which the present invention is addressed. Referring to FIG. 2, the present inventor has discovered that, to prevent the aforementioned electrical problems, the internal connection for a down hole heating unit must be impenetrably shielded from the pressures and hostile chemical agents which surround the unit in the well bore.
[0024] As shown in FIG. 2, a terminal portion of the heater rods 26 which connect to leads 24 are encased in a cement block 28 of high temperature cement. The presently preferred “cement” is an epoxy material which is available as Sauereisen Cement #1, and which may be obtained from the Industrial Engineering and Equipment Company (“Indeeco”) of St. Louis, Mo., USA. Cement block 28 is, in turn, encased in a steel fitting assembly 30 (“encasement means”), each component of which is welded with continuous beads to each adjoining component. To safely admit leads 24 to the interior of heating unit 20 , a CONAX BUFFALO sealing fitting 32 (available from the Conax Buffalo company of Buffalo, N.Y., USA) is used to transition the leads 24 from outside the production tubing 12 to inside heating unit 20 where they connect with rods 26 .
[0025] Fitting assembly 30 and sealing fitting 32 are, as would be apparent to anyone skilled in the art, designed to threadingly engage heating unit 20 to the perforated tubing which is up hole from heating unit 20 .
[0026] The shielding of the electrical connections between leads 24 and rods 26 is crucial for long-term operation of a down hole heating system of the present invention. Equally important is that power is reliably delivered to that connection. Therefore, solid copper leads with KAPTON insulation are used, such leads being of a suitable gauge for carrying the intended 16.5 Kilowatt, 480 volt current for the present system with its 0.475 inch diameter INCOLOY heater rods 26 (also available from Indeeco).
[0027] The present invention includes the method for use of the above-described system for heat treating an oil or gas well for improving well flow. The method would be one which included use of a down hole heating unit with suitably shielded electrical connections substantially as described, along with installation of the heat-retaining elements also as describe to properly focus heat on the producing formation.
[0028] In addition to the foregoing, it should be understood that the present method may also be utilized by substituting cable (“wire line”) for the down hole pipe for supporting the heating unit 20 while pipe is pulled from the well bore. In other words, one can heat-treat a well using the presently disclosed apparatuses and their equivalents before reinserting pipe, such as during other well treatments or maintenance during which pipe is pulled. It is believed that this approach would be particularly beneficial in treating deep gas wells with an iron sulfide occlusion problem.
[0029] Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limited sense. Various modifications of the disclosed embodiments, as well as alternative embodiments of the inventions will become apparent to persons skilled in the art upon the reference to the description of the invention. It is, therefore, contemplated that the appended claims will cover such modifications that fall within the scope of the invention. | A down hole heating system for use with oil and gas wells which exhibit less than optimally achievable flow rates because of high oil viscosity and/or blockage by paraffin (or similar meltable petroleum byproducts). The heating unit the present invention includes shielding to prevent physical damage and shortages to electrical connections within the heating unit while down hole (a previously unrecognized source of system failures in prior art systems). The over-all heating system also includes heat retaining components to focus and contain heat in the production zone to promote flow to, and not just within, the production tubing. | big_patent |
FIELD OF THE INVENTION
This invention relates generally to down hole tools for conducting mechanical activities in wells and, more specifically, relates to a simply and efficiently operable mechanism for installing and removing objects in wells, including objects that might be stuck or lost within a well bore.
BACKGROUND OF THE INVENTION
The subject matter hereof is related to the subject matter of U.S. Pat. No. 4,061,389 and is directed specifically to the improvement that promotes effective connection of a pull tool to a down hole object or fish and simple and effective disconnection of the pull tool from the article if such is desired.
During drilling operations, well servicing operations and the like, objects may become lost or stuck within a well bore and these objects are typically referred to in the industry as "fish." For example, a section of drill pipe or production tubing might become disconnected from a pipe string and it is then necessary to introduce a pull tool into the well bore, establish connection with the fish and then remove the fish. Many different types of pull tools, grap pling devices, spears, etc. have been developed for the purpose of conducting fishing operations in well bores. It is typical for wire line operations to be utilized for the purpose of introducing a pull tool into the well bore for fishing operations.
In many cases, down hole devices are positioned within casing and tubing strings for the purpose of controlling well operations. In most cases, such down hole devices are equipped with API Standard fishing necks which normally include an undercut shoulder to enable grappling by standard installation and retrieval tools. Quite often the API Standard fishing neck will become corroded or eroded by well conditions to the point that only a stub pipe is exposed without the usual undercut shoulder that is provided on the fishing neck. Connection between a wire line controlled fishing tool and a worn fishing neck may be accomplished by means of an overshot type grappling device generally defined by a collet structure having internal teeth that establish a gripping relation with the worn fishing neck. Although overshot type retrieving tools are successfully utilized in many cases, a common problem with such tools is the inability of the operator to achieve disconnection from the worn fishing neck in the event the tool is unable to accomplish an effective pulling operation. Occasionally, disconnection can be achieved by a substantial jarring or other violent mechanical movement, but, in some cases, disconnection of the pulling tool from the fish is extremely difficult if not impossible. In cases where the pulling tool or wire line is inadequate for the pulling operations that are required, it is necessary that the pulling tool be disconnected from the fish and replaced with a wire line controlled pulling tool of substantially greater pulling capacity. If a light-weight wire line pulling tool is unable to accomplish the pulling operation and becomes firmly fixed to the fish or other object to be pulled, retrieval of the fishing equipment itself obviously compounds the problem and adds materially to the expense of the service operation.
As mentioned above, application of shocks to the pulling tool will sometimes result in disconnection, thereby enabling service personnel to remove the wire line pulling tool and substitute a tool and wire line of substantially heavier gauge. Application of mechanical shocks to the down hole equipment of the well and the wire line tool itself can easily cause failure or excessive wear of one or more of these mechanical components. It is desirable, therefore, to provide down hole service equipment, such as wire line controlled pulling tools, that will effectively become interconnected with down hole objects such as wire line tools, fish, etc., and, in the event disconnection is necessary, will readily become disconnected upon simple mechanical movement of a wire line controlled pulling tool.
SUMMARY OF THE INVENTION
The present invention may effectively take the form of an external pull tool or overshot that is adapted for use in well servicing operations or an internal pull tool or spear, depending upon the particular service operation that is involved. Although not restricted particularly to wire line service operations, the invention is effectively adapted to be provided on a wire line controlled pulling tool and run into the well casing or well bore for the purpose of establishing a mechanical connection with an object positioned in the well bore and applying sufficient force thereto to remove the object from the well. Whether the pulling tool takes the form of an external overshot or an internal spear, in each case, the tool structure takes the form of an outer tubular body having an inner body structure disposed in movable relation therein. Telescoping movement of the inner and outer body structures of the tool causes the overshot or spear to selectively move into gripping relationship with the object that is to be removed from the well bore. The tubular outer body is secured about the inner body by means of a catch mechanism having a locking position and an unlocking position, depending upon the relative positions of the inner and outer body structures. A pin structure forming a part of the catch mechanism is selectively positioned within pin receiving grooves and a control spring is employed to ensure that the pin alternately enters one or the other of a pair of unlocking or locking grooves each time the inner and outer body structures are cycled linearly relative to one another. If the tool is locked in relation to the fish or other object positioned in the well bore, unlocking may be achieved simply by downward movement of the control line tool followed by subsequent upward movement thereof. Further, in the event the pulling tool is unlocked with respect to the down hole object, locking may be achieved simply by downward movement of the pulling tool, followed by subsequent upward movement thereof.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is an axial sectional view of a mechanism for installation and retrieval of down hole objects, which mechanism is constructed in accordance with the teachings of the present invention and is provided with an expandable collet type device for establishing internal connection with an object to be pulled from the well bore.
FIG. 1a is a partial sectional view of an object that is positioned within a well and illustrating the various surfaces thereof that are engageable by a pulling tool according to the present invention.
FIG. 2 is a fragmentary elevational view of the internal body structure of the tool taken along line 2--2 of FIG. 1 and illustrating a portion of the catch mechanism thereof in detail.
FIG. 3 is a partial elevational view of an external grapple device that may be substituted for the collet structure shown at the lower extremity of FIG. 1 and incorporating external teeth for internally gripping an object such as drill pipe or tubing.
FIG. 4 is an axial sectional view of a mechanism for installation and retrieval of down hole objects in a well which mechanism represents an alternative embodiment of the present invention adapted for overshot type grappling and removal of objects from well bores.
FIG. 5 is a fragmentary elevational view of the inner body structure of the mechanism of FIG. 4, taken along line 5--5 of FIG. 4 and illustrating a portion of the catch mechanism thereof in detail.
FIG. 6 is a fragmentary sectional view representing the lower portion of an overshop type down hole pulling tool representing a further modified embodiment of the present invention that is adapted for engagement with a standard fishing neck of a down hole object.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings and first to FIG. 1, there is shown an object removal tool generally at 10 having a upper sub 12 that is formed to define a fishing neck 14 and upper external threads 16 so as to enable the tool to be run into the well by suitable wire line equipment that establishes a threaded connection with external threads 16 of the upper sub. In the event the wire line equipment should become inadvertently separated from the upper sub 12, a wire line controlled fishing tool may simply be run into the well and will establish a suitable interconnection with the fishing neck structure 14. The upper sub 12 is also formed to define an internal bore or fluid passage 18 and a lower internally threaded extremity 20 that establishes threaded connection with an externally threaded upper portion 22 of an inner body element 24 that is also formed to define an internal bore or fluid passage 26. The intermediate portion of the inner body 24 is formed to define a portion of a locking mandrel illustrated generally at 28 and which will be described in detail hereinbelow. The inner body structure 24 is formed to define an externally threaded lower portion 30 that is adapted to receive the internally threaded portion 32 of a piston and guide element 34 having an outer cylindrical surface 36 that is adapted to be disposed in close fitting, sliding relationship with an internal cylindrical surface 38 defined by an outer body structure or housing 40. The piston and guide element 34 is also formed to define an external seal groove within which is received an annular sealing element 42, such as an O-ring or the like, that establishes a sealed relationship with the inner cylindrical surface 38 of the housing structure 40. The piston and guide portion functions to establish proper positioning relative to the inner and outer body structures 24 and 40 during all phases of relative movement therebetween. The lower portion of the outer housing structure is formed to define an internally threaded portion 44 that is adapted to receive an externally threaded portion 46 of a body closure element 48 that is also formed to define a cylindrical internal bore 50 and an externally threaded tool adjustment portion 52. An adjusting spacer element 54 is threadedly received by the elongated externally threaded adjustment portion 52 of the closure element 48 and may be locked in place relative to the adjustment portion 52 by means of a locking ring 56. By adjusting the position of the adjustment spacer 54 relative to the adjustment portion 52 of the closure element, a connection device such as a spear slip or collet may be accurately positioned with respect to internal locking structure of various locking mandrels, pipes, etc.
As illustrated in FIG. 1, a tool connector sub 58 having an internal fluid passage 60 formed therein, is also formed to define an externally threaded connector portion 62 that is adapted to be received by an internally threaded portion 64 of the piston and guide element 34. The tool connector sub 58 is also formed to define a transverse passage or port 66 that establishes communication between the passage 60 of the connector sub and an annulus or chamber 68. The lower extremity of the tool connector sub 58 is formed to define an internally threaded portion 70 that is adapted to receive an externally threaded connector portion 72 of a tool support sub 74 that is formed to define an internal passage 76 that is in communication with a restricted internal passage 78 defined at the upper extremity of the tool support sub. A nose cone element is threadedly connected to the lower extremity of the tool support sub 74 and defines a frusto-conical cam surface 82 that reacts with internal cam surfaces 84 defined on a plurality of collet elements 86 that are integral or interconnected to the lower portion of the threaded adjustment portion 52 of the closure element 48. As the nose cone element 80 is moved upwardly relative to the collet elements 86, the cam surfaces react thereby forcing the collet elements outwardly in order that collet shoulder surfaces 88 will engage internal support surfaces 90 defined within the object 92 to be removed from the well bore. The collet elements 86 are properly positioned relative to the internal shoulder 90 of the objects 92 when the lower extremity of the adjustable spacer element 54 is brought into contact with the object. Accurate positioning may be accomplished simply by adjusting the position of the adjustable spacer element relative to the threaded adjustment portion 52 of the closure element 48. With reference to FIG. 1a, the various dimensions referred to as A, B and C may be adjusted for by means of the adjustment spacer 54. If dimension B is distorted, such as by erosion, corrosion, etc., the adjustment spacer may be positioned in such manne as to cause the spear slip structure to engage dimension A, thereby establishing a firm interconnection between the pulling tool and the object 92. If dimension A is distorted, a fishing operation may be accomplished by adjusting the spacer element 54 in order that the collet structure illustrated in FIG. 1 or the slip structure illustrated in FIG. 3 may be utilized to establish a firm connection with dimension B defined by the object 92. In the event dimensions A and B are both distorted, then the adjustable spacer element 54 may be positioned in such manner as to cause the spear slip structure shown in FIG. 3 to establish firm engagement with dimension C. In this case, the spear slip structure illustrated in FIG. 3 takes the general form of the collet structure illustrated in FIG. 1 with the exception that slip elements 94 are formed at the lower extremities of the yieldable fingers 96 and slip teeth 98 are defined for the purpose of establishing a firm gripping relationship with the cylindrical surfaces defined at B or C in FIG. 1a.
It is desirable to provide means for controlling, locking and unlocking of the collet or spear slip structures illustrated in FIG. 1 with respect to the object 92 illustrated in FIG. 1a. In order to facilitate locking and unlocking, the pulling tool structure is provided with a controllable locking mechanism illustrated at the central portion of FIG. 1 and shown in detail in FIG. 2. The inner body structure 24 is formed to define a plurality of locking or latching recesses, three of which are illustrated in broken lines at 100 and 102, and one recess being shown in full line at 104. Each of the locking or latching recesses is of substantially identical configuration and function together with other structure to provide controlled guiding or tracking movement for guide pins that are associated respectively with each of the recesses. As shown in FIG. 1, a pair of guide pins 106 and 108, each being retained by the outer housing structure 40, are associated respectively with latching recesses 100 and 102 while in FIG. 2, guide pin 110 is associated with latching recess 104. In the case of the pulling tool illustrated in FIG. 1, the latching mechanism incorporates four substantially identical latching recesses and guide pins being received respectively therein. It should be borne in mind, however, that the particular number of latching recesses and guide pins is not in any way restrictive as regards the present invention. In some cases, only two latching recesses and guide pins may be employed to control latching and unlatching of the pulling tool mechanism.
As illustrated in FIG. 2, each of the latching recesses takes the form shown defining a pair of lower pin receiving slots, grooves or receptacles 113 and 115 that are each adapted to receive the guide pin 110 and inclined cam surface 112 is defined between slots. A pair of parallel guide surfaces 114 and 116 are also defined by the recess and a upper inclined cam surface 118 extends from surface 116 to a upper pin receiving receptacle 120 that is also adapted to receive the guide pin 110 depending upon particular vertical positioning of the inner and outer body structures.
It should be pointed out that pin receiving slot 113 comprises an unlatching slot while pin receiving slot 115 defines a latching slot. When the pin member 110 is received within the unlatching slot 113 as shown in FIG. 2, the inner body structure 24 and the nose cone 80 will be moved upwardly relative to the outer body or housing portion 40 and the collet elements 86 or spear slip elements 94 will be positioned at the unexpanded or inner positions thereof and will not be capable of establishing interlocking engagement with the object to be removed from the well bore. When the pin member 110 is received within the latching slot 115, the inner body structure 24 will be positioned upwardly relative to the outer housing structure 40, thus causing the nose cone element 80 to cam the collet elements 86 or spear slip elements 94 outwardly into engaging and locking relation with the object.
In order to control selective positioning of the guide pin member 110 relative to the latching or unlatching slots, relative rotation of the inner and outer body portions of the pulling mechanism must occur. By providing appropriate guide surfaces within the recess structure, the guide pin will engage these guide surfaces and will accomplish relative rotational positioning of the inner and outer body portions. Inclined cam surfaces 112 and 118 will obviously induce transverse movement of the guide pin 110 when the pin is in engagement with these cam surfaces and the inner and outer body structures are caused to move axially one relative to the other. It is desirable to provide means for ensuring alternate latching and unlatching of the pulling tool mechanism in order that the operating personnel thereof may ensure appropriate selective control of the pulling tool mechanism to accomplish desired results. It is desirable, therefore, to provide a closed circuit feature by means of appropriate cam surfaces and ensure that the pin is capable of moving only within the restrictions of the closed circuit and thus enabling operating personnel to provide efficient selective control. In accordance with the present invention, a plurality of spring elements are provided as shown at 122, 124 and 126. Each of these spring elements is substantially identical and, as illustrated generally at 124, the spring elements incorporate an intermediate support portion 128 that is interconnected with the inner body structure by any suitable means of connection. The spring element is formed to define a pair of opposite disposed camming elements 130 and 132 that are interconnected with the intermediate portion 128 and are free for movement within the recess 104. As the outer body or housing moves downwardly relative to the inner body, guide pin 110 is moved downwardly and engages the inclined spring portion 132. The free extremity of the spring is thus forced into engagement with the surface 116 and therefore prohibits further axial movement of the pin 110 unless there is relative rotation between the inner and outer body structures. As the pin 110 moves downwardly within the recess 104, the inclined spring portion 132 causes rotation of the pin and thus relative rotation of the inner and outer body structures until the pin reaches the level of the intermediate axially oriented portion 128. After the pin has been so oriented with respect to the spring element 124, further downward movement of the pin causes the pin to contact the lower inclined spring portion 130. At this point, it should be noted that the pin 110 will be oriented above the tapered cam surface 112 or the unlatching receptacle or groove 113. If the pin is caused to move downwardly from this point, it will move directly into the unlatching receptacle 113 or first engage the cam surface 112 and will then be cammed into the latching receptacle 115. The pulling tool mechanism, therefore, may be unlatched simply by causing limited axial movement of the inner and outer housings and then causing relative movement of the inner and outer housings in the opposite direction. When it is again desired to cause the pulling tool mechanism to be moved to the latching position thereof, the guide pin 110 is moved upwardly from the latching receptacle 115 or from any position therebelow and is caused to move into forcible engagement with the inclined spring portion 132. Further upward movement of the guide pin 110 causes the inclined portion 132 of the spring to yield, thereby allowing the guide pin 110 to enter the upper portion of the recess 104 where it engages the inclined cam surface 118 thus causing relative rotation of the inner and outer body structures until the pin has moved into contact with the upper pin receptacle 120. After this has been accomplished, downward movement of the pin 110 relative to the recess 104 will cause the pin to move into engagement with the spring element 124. If slight rotational movements occurred as the pin is being moved upwardly, the pin may contact the inclined upper portion 132 of the spring 124. If this occurs, the upper portion of the spring will yield into engagement with the side surface 116 of the recess and will cause the pin to be cammed toward side surface 114, thus causing relative rotation of the inner and outer body structures. Further axial movement of the pin relative to the recess 104 will cause the pin to engage the lower inclined portion 130 of the spring element thus causing the lower portion of the spring element to yield inwardly to the extent necessary to allow the pin 110 to pass. In this condition, the pin 110 will be oriented properly with respect to the unlatching slot or receptacle 113 and it will move directly into the unlatching slot, thus locking the inner and outer body portions of the pulling tool mechanism against further relative rotation. The collet structures 86 or the slip structures 94 will therefore be disconnected from the object in this particular condition and the pulling tool may be removed from the well bore, if desired. Also, if desired, the pulling tool may be caused to move into subsequent latching engagement with the object within the well bore without necessitating removal and recocking of the latching mechanism. Latching and unlatching of the pulling tool from the object may occur any suitable number of times within the discretion of the operating personnel in charge of the tool pulling or fishing operation. There is no necessity to cause jarring or mechanical vibration of the fishing tool in order to accomplish removal of the object from the well or in order to accomplish release of the object from the pulling tool in the event the pulling tool is found insufficient to accomplish the pulling operation.
The upper portion of the outer housing structure is defined by an internally threaded portion 134 that is adapted for threaded connection to an externally threaded portion 136 of an upper closure or cap structure 138 that defines an aperture 140 through which the inner body structure 24 extends. An annular sealing element 142 as an O-ring or the like retained within an appropriae seal groove establishes a sealed relationship between the inner body structure 24 and the closure portion 138 of the outer housing. The upper portion of the closure element 138 is formed to define a shoulder surface 144 against which the lower portion of a compression spring element 146 is seated. The upper portion of the spring element is received in engagement with an abutment surface 148 defined by the upper sub element 12. The compression spring element 146 functions to maintain the inner body portion 24 of the mechanism in an upward position relative to the outer housing 40 and, in the free condition thereof, causes the guide pin element 110 to be positioned at one of the lower receptacles 113 and 115. The guide pin is caused to move upwardly within the recess 104 when the adjustable spacer element 54 is moved into engagement with the upper extremity of the object, thus causing the collet or spear to be inserted into the object and positioned for engagement with an appropriate surface or structural formation therein. Further downward movement of the inner body element 24 relative to the outer body structure results in downward movement of the guide pin 110 relative to the recess structure 104 thus positioning the guide pin 110 within respective ones of the unlatching or latching slots 113 and 115. Downward movement of the outer housing structure 40 relative to the inner body structure 24 is induced by the compression spring 146 when the tool mechanism is moved upwardly and the force against the lower portion of the outer housing is relieved by such upward movement.
Referring now to FIGS. 4-6, there is illustrated a pulling tool mechanism that is in the form of an overshot structure but which functions from the latching, and unlatching standpoint in similar manner as described above in connection with the tool illustrated in FIGS. 1-3. The overshot pulling tool mechanism is illustrated generally at 150 in FIG. 4 and includes an upper sub structure 152 that is formed to define an internally threaded upper portion 154 that may be interconnected with suitable wire line running equipment. The upper sub member 152 is also formed to define an internal passage 156 that is enlarged at the lower portion thereof and defines a receptacle 160 adapted to receive a tubular sleeve element 162 that extends through a guide aperture 164 defined at the lower portion of the upper sub. The lower portion of the upper sub is also externally threaded and is adapted to receive the internally threaded upper portion 166 of an upper housing 168 that cooperates with the internal tube 162 in such manner as to define an annulus or spring chamber 170 adapted to receive a compression spring 172. The compression spring is interposed between abutment surfaces 174 and 176 that are defined respectively by the upper sub member 152 and the upper portion of an inner body structure 178 that is movably disposed within an intermediate latching mandrel portion 180 of the outer body or housing of the tool mechanism 150. The latching mandrel portion 180 of the body structure is provided with an upper externally threaded portion 182 that is adapted for threaded engagement with the lower internally threaded extremity 184 of the housing structure 168. The latching mandrel portion 180 of the housing is also formed to define an externally threaded lower extremity 186 that is adapted for threaded engagement with the upper internally threaded portion 188 of an overshot housing 190 that defines a frusto-conical internal cam surface 192 and an external tapered guide surface 194 that functions to guide objects into the overshot housing or to guide the overshot housing relative to such objects.
The inner body structure 178 is defined by an enlarged upper extremity defining a stop shoulder 196 that is adapted to engage the upper portion of the upper externally threaded extremity of the latching mandrel 182. Thus, the shoulder relationship between the inner body structure 178 and the upper extremity of the latching mandrel prevents further downward movement of the inner body structure relative to the outer housing. As shown in FIG. 4, the inner body structure 178 may move only upwardly relative to the outer housing and such movement is of course against the compression of the spring 172 and causes movement of the guide tube 162 relative to the guide aperture 164. The inner body structure 178 includes a reduced diameter portion 198 having a lower externally threaded extremity 200 that is received in threaded engagement within an internally threaded connector element 202 that defines a shoulder surface 204 capable of supporting the lower extremity of a latching control element 206 that is positioned about the tubular portion 198 of the inner body. The latching control element 206 has an outer configuration that is merely reversed in comparsion to the structure of the latching control mechanism illustrated in FIG. 2.
The connector element 202 is formed to define a lower internally and externally threaded portion 208 that is adapted externally to receive an internally threaded portion of a collet element 210 having a plurality of depending spring fingers 212 that are formed to define tapered external cam surfaces 214 and internal gripping teeth 216. As the collet mechanism is cammed radially inwardly responsive to downward movement of the inner body structure 178, the gripping teeth 216 of the respective collet fingers establish a locked engagement with a fish that has been received within the overshot housing 190.
For the purpose of achieving actuation of the latching control mechanism 206, an adjustable spacer tube 218 is threadedly connected to the lower internally threaded portion 208 of the connector element 202 and is adjustably locked relative thereto by means of a locking element 220. An enlarged abutment element 222 is threadedly secured to the lower extremity of the tube 218 and is positioned to contact the object or fish that is received within the overshot housing. Appropriate adjustment of the tube 218 relative to the connector element 202 will accurately position the lower extremity of the abutment element 222 in order to properly position the grappling teeth 216 of the collet fingers when latching movement occurs.
The latching mandrel 180 is provided with a plurality of guide pin elements such as shown at 224 and 226, having the inner extremities thereof projecting into respective latching recesses 228 and 230 and being maintained in fixed relation with the latching mandrel. The latching control element 206 is formed to define a plurality of recesses, one of which is shown in full line at 230 in FIG. 5. The recess is formed to define upper pin receptacle portions 232 and 234 that are adapted to receive and properly position the guide pin element 226 to achieve latching and unlatching configuration of the collet structure relative to the overshot housing. The recess 230 is also formed to define opposed generally parallel guide surfaces 236 and 238 and lower and upper tapered cam surfaces 240 and 242, respectively. The lower portion of the recess 230 defines a lower pin receptacle 244 that is adapted to receive the guide pin 226 in properly seated engagement therein. A plurality of guide spring elements are provided as shown generally at 246, one being positioned within each of the recesses and reacting with appropriate ones of the guide pins to induce relative rotational control and guidance of the pins as the pins move relative to the inner body structure. Each of the spring elements incorporates an intermediate portion 248 that is interconnected with respect to the latching control element 206 in any suitable manner and includes lower and upper inclined and yieldable extremities 250 and 252.
As the overshot mechanism 150 is moved downwardly into engagement with the fish, abutment element 222 contacts the upper extremity of the fish and further downward movement of the mechanism 150 causes the outer housing structure and the guide pins to move downwardly relative to the respective recesses, thus positioning the guide pins within respective ones of the latching and unlatching receptacles 232 and 234. In the position illustrated in FIG. 5, the pin 226 is moving toward the unlatching receptacle 234 and thus the collet fingers 212 are not cammed inwardly by the cam surface 192 into tightly secured engagement with the fish. In the event such latching movement is desired, the outer housing structure is moved upwardly, causing the force of the fish against the abutment element 222 to be relieved and thus allowing the compression spring 172 to urge the inner body structure 178 downwardly relative to the outer housing and thus, as seen in FIG. 5, causing a relative upward movement of the guide pin 226 as compared to the recess 230. When this occurs, the pin will engage the inclined yieldable portion 250 of the control spring and will cause relative rotational movement of the inner and outer body structures of the overshot mechanism thus causing the pin 226 to be oriented with respect to the latching receptacle 232 or with the inclined cam surface 242. The pin is then caused to move downwardly into engagement with the upper spring portion 252 which causes rotation of the latching control element 206, orienting cam surface 242 or latching receptacle of 232 relative to the pin. Relative upward movement of the pin as compared to the recess will then cause the pin to engage the cam surface and be cammed into the receptacle 232 or to be moved directly into the receptacle 232. Such movement will cause the lower cam surface 192 of the overshot housing to urge the lower extremities of the spring fingers into tight engagement with the fish, thus causing the teeth 216 of the grappling collet structures to establish appropriate gripping relationship with the object to be removed from the well.
In the event subsequent unlatching movement is desired, the inner and outer body structures are controllably shifted in such manner that the guide pin 226 will move downwardly in relation to the recess 230 thus causing the guide pin to engage the upper or lower yieldable portions of the control spring 246. If the upper portion 252 of the controlled spring is engaged, the guide pin will be cammed in such manner as to cause relative rotation of the inner and outer body portions and thus causing the guide pin to move into engagement with the yieldable lower portion 250 of the spring structure. Further downward movement of the pin will yield the lower spring portion and allow the pin to pass whereupon further upward movement will cause camming of the pin into the receptacle 244 by means of the tapered cam surface 240. The inner and outer body structures of the overshot mechanism then may be moved in such manner as to achieve upward movement of the pin relative to the recess 230, thereby causing the pin to be cammed into appropriate guided relationship past the yieldable upper extremity 252 of the spring structure 246 and into received relationship within the unlatching receptacle 234.
In FIG. 6 there is illustrated an overshot housing structure 254 having a tapered internal cam surface 256 that is capable of causing inward camming movement of spring fingers 258, thus positioning lower tool engaging elements 260 into gripping relationship with a standard fishing neck 262. An internal cylindrical surface 264 cooperates with the tool engaging elements 260 to maintain the tool engaging elements in properly interlocked relationship with the shoulder surface 266 of the fishing neck. The overshot mechanism illustrated in FIG. 6 functions in similar manner as the overshot grappling structure of FIGS. 4 and 5 and may be simply substituted for the lower portion of the structure illustrated in FIG. 4.
The latching and unlatching cycles described above in connection with FIGS. 4 and 5 may be repeated indefinitely without any necessity for removing the overshot mechanism from the well bore for resetting operations, etc. The mechanism may be latched and unlatched as many times as is appropriate to accomplish the service operation involved. Moreover, in the event the overshot type pulling tool is undersized for the particular pulling opertion involved, it may be simply unlatched from the fish or from the down hole tool, removed from the well bore and replaced with an overshot mechanism of heavier duty.
The present invention is thus intended for use in accomplishing a wide variety of down hole service operations including installation and removal of down hole tools and fishing operations for stuck or lost tools within the well bore. It is intended that the embodiments disclosed herein not be in any way considered limiting of the spirit and scope of the present invention, it being obvious that other embodiments of the invention may be employed within the teachings of the invention. Having thus described my invention in detail, | A pulling tool for retrieving an article or fish from a well bore and utilizing a spear or grapping type action to establish connection with the fish. Cooperative internal and external tubular members are selectively movable to secure the pulling tool to the fish or to release the fish. An internal spring element cooperating with a positioning pin establishes controlled relative movement of the internal and external tubular members upon simple linear movement of the tool. | big_patent |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the benefit under 35 U.S.C. §365(a) of PCT International Patent Application Ser. No. PCT/MX2011/000063 to the inventor, filed May 25, 2011, now pending, which in turn claims priority to co-pending Mexico patent application Ser. Nos. MX/a/2011/005499, filed May 25, 2011, and MX/a/2010/005899, filed May 28, 2010, each by the same invento. The entirety of the contents of each application is hereby incorporated by reference herein.
BACKGROUND
[0002] 1. Field
[0003] The example embodiment in general relates to stave floors, in particular to modular composed stave floors.
[0004] 2. Related Art
[0005] In patent application number MX/a/2010/005899, there are disclosed the drawbacks that exist in composed stave floors or engineering floors, which include at least a base substrate (after face) also known as a core and at least a sight substrate, of finished (face) or top part for the traffic surface. The sight substrate is selected from a group that consists of: noble hard woods, exotic woods, capricious woods which, for the formation of its seam, have great acceptance on the market.
[0006] In the known stave floors, the minimum material to be rushed for corrective maintenance is 1 mm, while it is known that the sight substrate, also referred to as micro plates or plates, has a thickness from 2 to 3 mm. The drawback of such a thin sight substrate thickness is that upon being sanded or rushed, the remaining material warms up and tends to be deformed and eventually becomes partially or completely detached, thereby completely spoiling the appearance of the floor, as related to its physical, aesthetic and functional properties.
[0007] Generally speaking, the micro plate or plate that constitutes the sight substrate, is “de-rolled” wood of the tree trunk from which it is obtained. This affects the aesthetic properties of the final product since the forces of the mechanical action on “de-rolling” generate a sheet that will tend to curl or recover its cylindrical original form. The base substrate nowadays is composed of slung wood or is plated against (triplay). Both sheets are joined by means of glue. A disadvantage of using only glue is that with the open period, both sheets can suffer deformations and/or changes of displacement between them, as well as changes of dimensions. Another disadvantage is that it is necessary to provide a uniform and level surface of assembly, in order to assemble both sheets, as well as to maintain a constant pressure in order to reach the desired adhesion when the glue is uniformly distributed between both substrates. Another disadvantage is the long cure or wait time that the pieces must remain static, without moving. So that the glue completely hardens, the cure or wait time may stretch several days.
[0008] The compose stave floors life, due to the thin thickness of the plate of the noble layer or sight substrate therein, is very short, and with no possibility of providing corrective maintenance. Though the materials are supplied pre-varnished from the supplier, the thin thickness of the sheet does not offer a solid base of attachment, the resistance of the glaze is poor, is susceptible to be easily scratched, or easily suffers the effect of peeling.
[0009] Currently, one problem of joining both sheets of plate is in preventing the displacement or change of dimensions. As previously noted, different factors, prevent that the sheets are fixed in a firm way, even though patent application number MX/a/2010/005899 tried to solve the problem, finding great benefits, it was not the optimal solution.
SUMMARY
[0010] An example embodiment is directed to a method for the manufacture of composed stave floors. The method includes providing a sight substrate having a thickness of at least 4 mm and providing a base substrate having a thickness of at least 12 mm. The base substrate and sight substrate are assembled together with glue and multidirectional holding means. The multidirectional holding means consist of dendrites, adhesion and horizontal reinforcement means, in the union plane; and adhesion and vertical reinforcement means, normal to the union plane.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Example embodiments will become more fully understood from the detailed description given herein below and the accompanying drawings, wherein like elements are represented by like reference numerals, which are given by way of illustration only and thus do not limit the example embodiments.
[0012] FIG. 1 is a perspective view of a conventional composed stave floor or conventional engineering floor.
[0013] FIG. 2 is a perspective cross-section view of a composed stave floor or engineering floor according to an example embodiment.
[0014] FIG. 3 is a side view of a composed stave floor or engineering floor according to an example embodiment.
[0015] FIG. 4 is a perspective cross-section view of a composed stave floor or engineering floor which depicts the means of holding according to an example embodiment.
[0016] FIG. 5 is a representation that shows a perspective top view of a conventional composed stave floor or floor of conventional engineering floor showing detachment.
[0017] FIG. 6 shows a top view of a conventional composed stave floor or floor of conventional engineering floor, wavy deformed.
DETAILED DESCRIPTION
[0018] Whereas the example embodiments will be described hereafter, it should be understood that the above mentioned embodiments will not limit the invention. The sizes in the figures are exaggerated with purpose of clarity.
[0019] One object of the example embodiments is to preserve the physical, aesthetic and functional properties in sight substrate of composed stave floors or engineering floors.
[0020] Another object is to provide a sight substrate for composite stave compounds or engineering floors, without any trend to be deformed.
[0021] An additional object is to bond both sheets without displacement or change of dimensions, using bonding means such as dendrite, glue, knitted wire, clamps, or cemented clamps or divergent legs.
[0022] Another object is to provide to the floors with a major time of useful life and to allow giving it corrective maintenance.
[0023] An additional object is to provide improved composed stave floors, with applied glaze from the supplier, eliminating the time and the inconveniences of the application of the glaze in a period of the installation. Site preferred glazes include aluminum oxide or another metal that provide higher hardness without changing its aesthetic appearance.
[0024] All the numbers, numerical parameters and/or ranges that are expressed here with, for example, sizes or thicknesses, used in the specification and claims, are to be understood as modified in all the instances by the term “approximately”. Accordingly, unless it is indicated on the contrary, the numerical parameters established in the following specification and attached claims are approximations that can change depending on the properties provided by the example embodiments. At a minimum, and not as an attempt for limiting the application of the doctrine of equivalents to the scope the claims, every numerical parameter should be considered at least in the light of the number of significant reported digits and for application of techniques of ordinary rounded.
[0025] Likewise, there is to be understood that any numerical range described herein is intended to embrace all the sub-ranges there included: for example, a range of “1 to 10” is intended to include all the intermediate sub-ranges (and including) the minimal described value of 1 and the maximum described value of 10, this is with a minimal value equal to, or major that 1 and one maximum value equal to, or minor that 10.
[0026] FIG. 1 is a perspective view of a conventional composed stave floor or conventional engineering floor. In FIG. 1 , there is depicted a conventional composed stave floor or conventional engineering, floor which includes at least a base substrate (after face) ( 10 ) also known as a core and at least a sight substrate, of finished face or top part ( 20 ), having a thickness from 2 to 3 mm for the traffic surface;
[0027] FIG. 2 is a perspective cross-section view of a compose stave floor or engineering floor according to an example embodiment. In FIG. 2 , is shown the base substrate (after face) ( 10 ) having a practical minimal thickness from 12 to 19 mm; the sight substrate or finished (face) ( 20 ) having a practical minimal thickness of at least 4 mm and the dendrites ( 15 ), for the traffic surface of a composed stave floor in accordance with the present invention;
[0028] FIG. 3 is a perspective cross-section view of a compose stave floor or engineering floor which illustrates multidirectional holding means, including: dendrite ( 15 ), in conjunction with adhesion means and horizontal reinforcement means, or in the union plane: glue, and adhesion means and vertical or normal reinforcement means perpendicular with respect to the union plane: clamp, divergent clamp and/or cemented clamp ( 30 ).
[0029] Referring to FIG. 3 , the multidirectional holding means includes: dendrites ( 15 ), in conjunction with adhesion and horizontal reinforcement means; in the union plane: glue; and adhesion and vertical reinforcement means perpendicular or normal to the union plane: clamp, divergent clamp and/or cemented clamp ( 30 ); that join the base substrate (after face) ( 10 ) with thickness from 15 to 19 mm and the sight substrate or of finished (face) ( 20 ) having a practical minimal thickness of at least 4 mm, for the traffic surface of a composed stave floor in accordance with the present invention.
[0030] In an embodiment, the face substrate of the example embodiment is obtained from decorative or functional substrate, wood cut in tangential form, quarter form or another possible cutting, giving it a beautiful appearance and without limiting the manifestation of the natural seams, preserving its properties of uniform physical resistance that is maintained along the length of the entire substrate.
EXAMPLES
Example of Composed Stave Floor or Conventional Engineering Floor
[0031] A conventional composed stave floor or conventional engineering floor was manufactured including at least a base substrate (after face) also known as a core and at least a sight substrate, of finished (face) or top part for the traffic surface. After a short period of time, the conventional composed stave floor exhibited detachment as shows in FIG. 5 .
[0032] On the other hand a test of deformation was conducted by applying the glue in conventional form to the sight substrate, of finished (face) or top part for the traffic surface, resulting in a simple sight perceptible frizziness as shown in FIG. 6 .
Example of Composed Stave Floor or Engineering Floor of the Invention
[0033] A composed stave floor or engineering floor of the example embodiment, was manufactured comprising a base substrate (after face) having a thickness of 15 mm and a sight substrate, of finished (face) or top part for the traffic surface having thickness of 6 mm. The assembly of both substrates was carried out by gluing both substrates, using multidirectional holding means: dendrite ( 15 ), in conjunction with adhesion and horizontal reinforcement means in the union plane: glue; and adhesion and reinforcement vertical means normal to the union plane: clamp, divergent clamp and/or cemented clamp ( 30 ), the clamps being distributed in an uniform way. The composed stave floor of the present invention thus obtained did not present deformation or any detachment. After a period of use when it required corrective maintenance, it was possible to provide the mentioned maintenance, obtaining again the physical, aesthetic and functional properties of the original floor. Thus, the example compose stave floor herein provides the floors with increased durability.
[0034] The example embodiments being thus described, it Will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the example embodiments, and all such modifications as would be obvious to one skilled in the art are considered to be included within the scope of the following claims. | Example embodiments relate to improvements to composed stave flooring, methods for the production thereof and the corrective maintenance of same. The improvements allow corrective maintenance to be performed without negatively affecting the physical aesthetic and functional properties thereof. The flooring comprises a sight substrate and a base substrate, with the sight substrate having a minimum practical thickness of 4 mm and the base substrate having a minimum practical thickness of 12 mm, the two substrates being assembled using adhesive and securing means that distribute the adhesive uniformly between both substrates, thereby rendering the flooring more durable and stable. | big_patent |
TECHNICAL FIELD
This invention generally relates to ladders, and, more particularly to ladder attachments for positioning the ladder away from the work surface, preventing the ladder from defacing the work surface, and preventing the ladder from slipping or sliding.
BACKGROUND OF THE INVENTION
A ladder is used to help people reach places they would not ordinarily be able to reach. Ladders are often used to climb onto roofs of buildings and are used when washing window or painting. In normal use, the bottom portion of the ladder rests on the ground or other surface, and the top end of the ladder typically leans against the building or work surface. The ladder is oriented at an angle which makes it easy for a user to climb up and down the ladder, and also aids in keeping the ladder from slipping.
One problem with ladders, especially when painting or cleaning the exterior of a house, is that there is an amount of instability because the ladder rests on the side of the house with the only contact with the house being a small portion of the siderails of the ladder. When a person on the ladder reaches outside the rails, the center of gravity shifts causing one or both rails may slide along the work surface, thereby damaging the work surface. Accordingly, it will be appreciated that it would be highly desirable to have a ladder that has lateral stability under normal working conditions and resists sliding.
Another problem with typical ladders is that the siderails of the ladder rest on the work surface with a very small contact area which sometimes dents, scrapes, bruises or otherwise defaces the work surface. It is desirable to have a ladder that contacts the work surface with a broad surface area that does not deface the work surface.
With typical ladders, a work surface with a corner presents a problem. The ladder has to be positioned on one of the two surfaces forming the corner to stabilize the ladder, but this makes the other surface difficult to reach. A typical ladder cannot straddle the corners because the rungs would rest against the corner with the siderails void of contact with the two surfaces creating an unstable condition. Accordingly, it will be appreciated that it would be highly desirable to have a ladder that can straddle a corner without losing stability.
SUMMARY OF THE INVENTION
The present invention is directed to overcoming one or more of the problems set forth above. Briefly summarized, according to one aspect of the present invention, a brace for a ladder having first and second siderails connected by a rung comprises an extension arm having a flange on one end portion and an opening in the distal end portion. The flange has first and second openings. A U-bolt has its legs inserted through the first and second openings of the flange. The legs have threaded ends and are spaced to receive said ladder rung therebetween. First and second nuts are threadably mateable with the legs of the U-bolt to secure the flange to the U-bolt. A resilient pad assembly is pivotally connected to the extension arm.
It is an object of the present invention to provide a non-slip gripping portion for a ladder that grips the work surface without damaging the work surface.
Another object of the invention is to provide ladder which effectively increases the contact area of the ladder with the work surface.
Another object of the invention is to provide an attachment for a ladder to improve the lateral stability of the ladder.
Still another object of the present invention is to provide a ladder that can straddle a corner without losing stability.
These and other aspects, objects, features and advantages of the present invention will be more clearly understood and appreciated from a review of the following detailed description of the preferred embodiments and appended claims, and by reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric view of a preferred embodiment of a ladder with large contact area braces attached in accordance with the present invention.
FIG. 2 is a diagrammatic view of a ladder with large contact area braces similar to FIG. 1, but illustrating another embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, a ladder 10 has first and second siderails 12, 14, and a plurality of rungs 16 extending at spaced intervals between the siderails 12, 14. In the ladder 10, the length of the rungs 16 is fixed and thereby fixes the width of the ladder 10. The width of the ladder 10 typically ranges from about ten to about twenty inches, while the length ranges from about ten to about forty feet or more. Thus, the ladder 10 is very long compared to its width.
A first large contact area brace assembly 18 is attached to the first siderail 12 of the ladder 10, and a second large contact area brace assembly 20 is attached to the second siderail 14 of the ladder 10. The brace assemblies 18, 20 are interchangeable, and the left brace 18 may be used on the right siderail 14 while the right brace 20 is used on the left siderail 12. Only the right brace assembly 20 will be described in detail herein with it being understood that the left brace assembly 18 is identical.
The right brace assembly 20 includes an arm 22 with a flange 24 formed on one end opposite its distal end. On the distal end, the arm 22 has a bore for vertically pivotally connecting a resilient pad assembly 26, preferably by means of a bolt 28. Such a resilient pad assembly is described in detail in U.S. Pat. No. 4,754,842, which issued to the present inventor on Jul. 5, 1988, and which is incorporated herein by reference.
The flange 24 has two openings through which the two ends a U-bolt 30 extend. The two ends of the U-bolt 30 are secured with nuts, and washers as desired. The U-bolt 30 encircles the rung 16 which is preferably the top rung of the ladder 10, but may be positioned about any rung on the fly rail of the ladder 10 without hindering the extension and retraction of the ladder 10. The arm 22 and flange 24 are preferably formed of a single piece of steel or other strong, durable material. When a rigid piece of steel is used for the flange 24, the U-bolt 30 may simply be secured with nuts with enough torque to maintain the arm 22 in position. Lock washers are not necessary because the nuts on the U-bolt 30 can be tightened sufficiently as desired. When the flange 24 is made of softer material, washers may be used so that the flange 24 does not deface or deteriorate.
A clamp 32 is formed from an L-shaped piece of material. The arm 22 has an opening that is alignable with an opening in the clamp 32. The clamp 32 is positioned in abutting contact with the siderail 14 and arm 22 and secured in position with a bolt through the openings in the arm 22 and clamp 32. The opening in the arm 22 may be an elongated opening or slot so that the clamp 32 can be moved or adjusted to accommodate different sizes of ladders 10. The left brace assembly 18 is constructed in the same manner as the right brace assembly 20 with the exception that the clamp abuts the left arm and left siderail.
Referring to FIG. 2, another embodiment of an arm 22' illustrated wherein the arm 22' has a twist to rotate the opening in the distal and of the arm 22' about ninety degrees so that the resilient pad assembly 26' pivots horizontally instead of vertically. The ability to pivot horizontally allows the ladder 10 to straddle corners because the pad 26' can be pivoted to contact opposite faces of a corner. Inside corners, as well as outside corners, can be straddled.
While operation of the present invention is believed to be apparent from the foregoing description, a few words will be added for emphasis. The brace assembly 20 is installed by attaching the resilient pad assembly 26 to the arm 22 with the bolt 28 so that the pad assembly pivotally moves on the arm 22. After attaching the pad assembly 26, the arm 22 is moved toward the rung 16 so that the flange 24 abuts the rung 16. The U-bolt 30 is inserted and the nuts finger tightened. With the U-bolt nuts finger tight, the clamp 32 is positioned with one side of the L-shaped clamp 32 abutting the bottom surface of the siderail 12 and the other side of the clamp 32 abutting the arm 22. The openings are aligned, a bolt is inserted and a nut is tightened to secure the clamp 32 to the arm 22. Once the clamp 32 is securely tightened in position, the nuts on the U-bolt are finally tightened to secure the brace assembly 20 in position. When assembled in this manner, the clamp 32 exerts a force against the bottom face of the siderail 14 to prevent any motion of the arm 22 toward or away from the siderail 14. In use on a flat work surface, the forces exerted against the brace assembly 20 are outward forces from the center of the ladder 10 toward the siderail 14. Thus, the U-bolt 30 can be torqued enough to prevent inward movement of the arm 22. In use on a corner work surface the forces exerted against the brace arm 22' may be inward or outward forces which are resisted by the action of the resilient pad 26' on the work surface.
When the length of the arm 22 exceeds about six to eight inches, the construction of the brace assembly 20 may be of heavier gauge material to resist forces tending to move the arm 22 toward the center of the ladder. Alternatively, the bolts securing the clamp 32 to the arm 22 may be a single bolt extending from the arm 22 of the right brace assembly 20 to the arm of the left brace assembly 18 with nuts abutting each side of each arm to resist inward movement of the arms, and outward movement as well. This can be advantageous when it is desired to position the arms inward of the siderails instead of abutting the siderails. As another alternative, the bolt 28 may be a single bolt extending from the right pad assembly 26 all the way over to the left pad assembly to thereby resist movement of the pad assembly 26 and arm 22 inward, and outward as well. Such arrangements could be useful in less substantial aluminum ladders and fiberglass ladders, and others, where there is a limit on the amount the U-bolt 30 can be torqued.
It will be now appreciated that there has been presented a an attachment for a ladder to improve the lateral stability of the ladder. The ladder that contacts the work surface with a broad surface area that does not dent, scrape or mar the work surface. The present invention to provide a non-slip gripping portion for a ladder that grips the work surface without damaging the work surface. The non-slip gripping portion effectively increases the contact area of the ladder with the work surface which improves the lateral stability of the ladder, and allows the ladder to straddle corners.
While the invention has been described with particular reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements of the preferred embodiment without departing from invention. In addition, many modifications may be made to adapt a particular situation and material to a teaching of the invention without departing from the essential teachings of the present invention.
As is evident from the foregoing description, certain aspects of the invention are not limited to the particular details of the examples illustrated, and it is therefore contemplated that other modifications and applications will occur to those skilled the art. It is accordingly intended that the claims shall cover all such modifications and applications as do not depart from the true spirit and scope of the invention. | Large contact areas braces for attachment to the siderails of a ladder maintain the top end of the ladder away from the work surface against which the siderails would ordinarily rest. Each brace provides a large surface area to contact the work surface to prevent defacing of the work surface by the side rails of the ladder. The large contact areas of the braces grip the work surface to prevent the ladder from slipping or sliding. The braces have contact pads that pivot horizontally so that the ladder can straddle corners. | big_patent |
CROSS-REFERENCE TO RELATED APPLICATION DATA
This application is a continuation-in-part of U.S. patent application Ser. No. 11/734,684, filed Apr. 12, 2007, which is a continuation-in-part of U.S. patent application Ser. No. 11/383,032, filed May 12, 2006.
BACKGROUND OF THE INVENTION
The present invention pertains to collated fasteners. More particularly, the present invention pertains to a collated nail strip formed with a debris-free plastic material for use in a fastener driving tool.
Fast-acting fastener driving tools are in widespread use in the construction industry. Such tools are used in industries ranging from re-fabricated housing construction to luxury residential, commercial and industrial construction. For use in these tools, the nails are assembled in strips that are inserted into a magazine of the tool. The strips are flat and the nails or other fasteners are held parallel to one another. The nails are assembled in a staggered or stepped manner such that the major axis of the nail forms an angle to the longitudinal direction of the strip. In presently known collated nails, the angle is about 0 degrees to 40 degrees and preferably between 15 degrees and 35 degrees. An in-depth discussion of such fasteners is provided in U.S. Pat. No. 5,733,085, to Shida, which is incorporated herein by reference. The strips can also be “rolled” or formed into coils for use in certain tools.
Presently known collated nails are assembled using tape strips or an extruded plastic material. The molten plastic (or polymer) in the plastic-formed strips is cooled and hardens to hold the nails in the strip form for use in the tool. The tape strips are formed from a kraft paper or other paperboard material having a plastic (polymer) adhesive on a surface thereof that is heated on contact with hot nails and, as it cools, adheres to the nails.
Although tape strips have the advantage of minimizing the debris that is formed as the tool is actuated and the nails are driven into the material (typically wood) to be fastened, the plastic strips provide ease of manufacture, especially for larger spaced nails. No materials, other than the nails and the plastic collating material are needed.
However, it has been noted that as the plastic collated nails are driven into the workpiece, the plastic material, not adhering to the nail, shatters and separates from the nail shank. This can create loose debris at the worksite which can result in housekeeping problems.
Accordingly, there is a need for a plastic collation system for strip-formed fasteners that reduces the tendency for the plastic to generate debris as the nail is driven into the workpiece. Desirably, the collation system reduces the tendency for the nail strip to corrugate or advance on itself in the tool magazine. More desirably, such a system minimizes the amount that the strip can flex, and maximizes the adhesion of the plastic to the nail shanks. More desirably still, such a system is configured to permit the collation to be coiled for use in driving tools that accept collations in this manner.
BRIEF SUMMARY OF THE INVENTION
A fastener assembly is for use in an associated fastener driving tool for driving a fastener from the assembly into an associated substrate, such as a wood substrate. The fastener assembly includes a row of fasteners arranged substantially parallel to each other. Each fastener has a shank.
A collation system is formed from a plastic material that is molded onto and adhered to the fasteners. The plastic material defines a collar portion that captures or at least substantially encircles the fastener shank and a connecting portion extending between and connecting adjacent collar portions. The plastic material is formulated from an adhesive polymer such as a polyolefin, a polyolefin blend, an epoxy or the like. When the fastener is driven from the driving tool, the collar portion remains adhered to the fastener such that the collar portion penetrates the substrate with the fastener.
In a present strip, the polymer is a blend of polypropylene and a maleic anhydride modified polypropylene and adhesion is effected by preheating the fasteners prior to molding the plastic material to the fasteners. A preferred preheating temperature is about 450° F. and preferably about 450° F. to 600° F.
In the strip, the fasteners are parallel to one another and at an angle relative to an axis of a selected one of the fasteners.
The connecting portion can be formed as a bridge and a rib in which the bridge and rib have a generally cruciform shape. The rib can be formed parallel to the collation. Alternately, the rib can be formed at an angle (not parallel to) the collation. Alternately still, the connecting portion has an embossed pattern formed therein.
In a present strip, the collation system includes upper and lower plastic moldings adhered to the fasteners. The upper and lower plastic moldings are formed parallel to one another, with the upper molding formed nearer to the head of the fastener and the lower molding formed nearer to the tip of the fastener. The lower molding is formed on the shank of the fastener within the lower half and preferably within about ½ inch of the tip of the fastener. The plastic molding can be formed having a taper to facilitate penetration into the substrate.
A method for making a fastener assembly includes the steps of arranging a plurality of fasteners in a row parallel to one another, preheating the plurality of fasteners to elevate the temperature of the fasteners, molding a polymer material onto the preheated fasteners and between adjacent fasteners to form a plastic collation having a collar that captures or at least substantially encircles a shank of each fastener and a connecting portion between adjacent fasteners and cooling the strip to form the fastener assembly. The strip can then be post heat treated.
The fastener assembly can also be configured to influence or encourage separation of the fasteners from one another (separation of the connecting portions) at a desired location. Such a configuration further reduces debris by reducing the impact on the connecting portion by the fastener as it is driven by the tool into the substrate.
The fastener assembly includes a row of fasteners arranged substantially parallel to each other and a collation system formed from a plastic material that is molded onto and adhered to the fasteners. The connecting portion includes a preferentially weakened region to influence separation of the connecting portion from the collar at a desired location.
A preferred preferentially weakened region is at about a juncture of the connecting portion and the collar portion, and most preferred a juncture of the connecting portion and the collar portion of a subsequent fastener in the row of fasteners.
The preferentially weakened region can be formed by a notch in the connecting portion, such as at an upper edge of the connecting portion. A notch can also be formed in a lower edge of the connecting portion. The upper edge notch can have an arcuate wall.
The preferentially weakened portion can be formed by the connecting portion having a varying cross-sectional area with a smaller cross-sectional area at the desired location than at other locations in the connecting portion. The connecting portion can include a bridge and a rib, such that the varying cross-sectional area corresponds to transitions between the rib and the collar portions being formed having different radii of curvature. The preferentially weakened region can be formed by a smaller cross-sectional area at the juncture of the connecting portion and the collar portion of a subsequent fastener in the row of fasteners than at a juncture of the connecting portion and the collar of the driven fastener.
The fasteners can also be positioned eccentrically relative to their respective sleeves to define a thin-walled sleeve section at the desired location.
The assembly can also be configured with the connecting portion including a rib that extends less than an axial length of the collar portion (e.g., is not as long as the collar), and the rib can have a width that is greater than the width of the collar.
The connecting portion can include a bridge that is integral with the rib and extends substantially the axial length of the collar portion, such that the rib and bridge have a substantially cruciform shape.
The rib can be tapered, narrowing toward the tip of the fastener, and the bridge can be tapered, narrowing toward the tip of the fastener. The rib can be a relatively thick, short element disposed at about an upper portion of the bridge. The rib can have a tapered shaped, narrowing in a direction proximal to a tip of the fastener. The taper can be incorporated into a diamond shaped rib.
The assembly can include upper and lower collations parallel to and spaced from one another. In such as a configuration, the lower collation (that is the collation closer to the tip) is narrower that the upper collation. Preferably, the lower collation is about ½ of the width of the upper collation.
These and other features and advantages of the present invention will be apparent from the following detailed description, in conjunction with the appended claims.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The benefits and advantages of the present invention will become more readily apparent to those of ordinary skill in the relevant art after reviewing the following detailed description and accompanying drawings, wherein:
FIG. 1A is a plan view of one embodiment of a nail strip or collation having a pair of plastic molded carrier strips, and FIG. 1B illustrates a coiled collation configuration;
FIG. 2 is a cross-sectional view taken along line 2 - 2 of FIG. 1 ;
FIG. 3 is a cross-sectional view taken along line 3 - 3 of FIG. 1 ;
FIG. 4 is an illustration similar to FIG. 2 , showing a tapered collar;
FIGS. 5A and 5B illustrate portions of strips having angled ribs; and
FIGS. 6 and 6A illustrate an alternate bridge portion that is embossed, in which FIG. 6A is a cross-section taken along line 6 A- 6 A of FIG. 6 ;
FIGS. 7A and 7B illustrate the locations at which a leading of driven nail is separated from the nail strip, in which FIG. 7A is a leading nail separation and FIG. 7B is a trailing nail separation;
FIGS. 8A and 8B illustrate various notch locations and configurations;
FIGS. 9A and 9B are cross-sectional views of embodiments of nail strips with concentric ( FIG. 9A ) and eccentric ( FIG. 9B ) nail placements and having large and small radius bridge to collar transitions;
FIGS. 9C and 9D are a cross-sectional view and an enlarged partial cross-sectional view of a nail strip with a reduced thickness neck area;
FIGS. 10A and 10B are alternate embodiments of stiff rib thin bridge ( FIG. 10A ) and no bridge ( FIG. 10B ) nail collation connecting portions;
FIGS. 11A-11E illustrate embodiments of the nail collations with tapered connecting portions;
FIG. 12 illustrates still another embodiment in which the upper and lower collations have different widths;
FIGS. 13A and 13B illustrate still another embodiment in which the fasteners include a penetration expanding portion;
FIGS. 14A and 14B illustrate still another embodiment in which the nail shanks have deformations thereon, below the plastic carrier strips; and
FIGS. 15A and 15B are side and partial cross-sectional views of still another embodiment of the nail collation system.
DETAILED DESCRIPTION OF THE INVENTION
While the present invention is susceptible of embodiment in various forms, there is shown in the drawings and will hereinafter be described a presently preferred embodiment with the understanding that the present disclosure is to be considered an exemplification of the invention and is not intended to limit the invention to the specific embodiment illustrated.
It should be further understood that the title of this section of this specification, namely, “Detailed Description Of The Invention”, relates to a requirement of the United States Patent Office, and does not imply, nor should be inferred to limit the subject matter disclosed herein.
Referring now to the figures and in particular to FIG. 1 , there is shown a nail strip 10 having a plastic collation system 12 embodying the principles of the present invention. In the illustrated strip 10 , the nails 14 are positioned at an angle α of about 20 degrees to the transverse direction of the strip 10 ; however, other angles α (including zero degrees) are contemplated for use with the present invention. The strip in FIG. 1B is a coiled collation.
As will be appreciated by those skilled in the art, the illustrated nails 14 are full head nails, rather than D-head (or clipped head) nails. Accordingly, the nails 14 provide increased holding characteristics (due to the increased surface area of the nail head H). However, it will also be appreciated that using full head H nails 14 requires that the strip 10 is fabricated with a slightly greater distance d 14 between the (axes A 14 of the) nails 14 to accommodate the larger nail heads H.
The nails 14 are collated and held to one another by the plastic collation 12 . The plastic collation 12 is molded to, over and around the shanks 16 of the nails 14 , and connects each nail 14 to its adjacent nail or nails (that is, extends between the nails 14 ). The collation 12 is formed as a contiguous molding (as indicated generally at 18 ) around and between the nails 14 ; nevertheless, for purposes of this disclosure, the molding 18 is viewed as having a collar portion 20 , which is that portion that encircles the nail shank 16 , and a connecting portion 22 , which is that portion that extends between and connects adjacent collar portions 20 . In the nail strip 10 illustrated in FIG. 1 , two plastic moldings or collations are shown, namely an upper molding or collation 12 a and a lower molding or collation 12 b , that are formed with structure similar to one another. The following disclosure is applicable for both of the moldings and are referred to collectively as molding or collation 12 . For purposes of the present disclosure, the term molded is intended to include all methods of forming the collation 12 on or to the nails 14 .
The present nail collation 12 differs from previously known plastic collations in a number of important aspects. First, rather than the plastic merely encircling and extending around and between the nails, the present collation uses a material that is molded (or formed) and adheres to the nails 14 . It has been found that plastic that is adhered to the nails, rather than merely molded around the nails is advantageous in that the plastic material tends to remain on the nail shank 16 during driving. That is, the collation 12 material is maintained on the shank 16 as the nail 14 penetrates the substrate and thus enters the substrate with the nail 14 . Advantageously, much less debris is generated during driving of a nail 14 from the present nail strip 10 compared to prior known nail strips.
It will also be appreciated that the adhesion of the plastic material to the nails 14 also has benefits vis-à-vis the rigidity of the nail strip 10 . That is, when the plastic merely encircles the nail shanks, the plastic can slip around the nail shanks. On the other hand, by adhering the plastic molding 12 to the shanks 16 , the nail strip 10 tends to become more rigid and is less likely to flex and to corrugate.
The material is an adhesive polymer, an epoxy or the like. The material can be, for example, an adhesive polyolefin such as a maleic anhydride modified polyolefin, such as polypropylene, polyethylene or the like. The material can include a blend of a polyolefin and a modified polyolefin, such as a blend of polypropylene and a maleic anhydride modified polypropylene. One or more other resins can also be used, such as a polyvinyl alcohol (PVA) based material, an ethylene vinyl alcohol (EVA) based material, an acrylonitrile butadiene styrene (ABS) based material, ionomers, methyl methacrylates and the like. Fillers can also be used as can blends of any of the materials, as suitable. Other materials will be recognized by those skilled in the art and are within the scope and spirit of the present invention.
A present plastic composition is a polypropylene resin that has been modified to enhance adhesion to surfaces, including metal surfaces. A preferred resin is a maleic anhydride modified polypropylene commercially available from Mitsui Chemicals America, Inc, of Rye Brook, N.Y., under the tradename ADMER® QF5512A.
It has been found that unexpectedly high levels of adhesion were achieved using these modified resins when the resins were applied to nails 14 that were heated to elevated temperatures prior to application of the polymer (resin). Samples of nails were prepared by preheating the nails to a temperature of about 450° F. to about 600° F., and preferably about 500° F. to 550° F. and molding the maleic anhydride modified polypropylene to the nails. These were tested against other molded nail strip compositions, in which the molding was carried out with the nails at ambient temperature and with the nails at elevated temperatures (shown as Cold and Hot under column listed as Nail Temp). Tests were also carried out with strips that were postmolding heat treated (shown in columns identified as As Extruded and After 30 Min. Bake). That is, after the plastic material has been molded to the nails, the nail strip was heated for a period of time (30 minutes) at a predetermined temperature. The results of the testing are shown in Table 1, below.
TABLE 1
PLASTIC ADHESION SHEAR STRENGTH OF
VARIOUS PLASTIC NAIL COLLATIONS
Plastic Adhesion Shear
Strength (lbs)
As
After 30
Bake
Polymer
Material
Nail
Ex-
Min.
Temp
Composition
Tested
Temp
truded
Bake
(° F.)
Polypropylene (PP)
Current
Cold
6.0
17.4
375
material
Modified PP-
Amplify GR
Cold
6.5
48.4
300
anhydride
205
Cold
6.5
44.4
350
Modified PP -
Amplify GR
Cold
0.0
39.9
300
anhydride
HDPE/anhydride
MSI
Cold
5.3
3.6
250
blend
Cold
5.3
90.9
350
Hot
64.0
86.5
350
Modified PE-
Bynel
Cold
6.7
5.9
250
anhydride
Cold
6.7
49.4
350
12% vinyl acetate
Elvax
Cold
4.5
12.0
225
copolymer
Cold
4.5
15.9
350
EMMA Copolymer
Suryin 9150
Warm
0.0
51.2
375
(Zn)
Modified PP-
Tymor
Cold
8.4
15.6
350
anhydride
CP97X110
Cold
8.4
88.0
375
Modified PP-
Admer
Cold
4.6
17.1
300
anhydride
QF551A
Cold
4.6
28.0
350
Hot
71.0
210.4
350
Blend
75% Current
Cold
7.0
7.3
350
PP
In Table 1, the plastic adhesion shear strength (in pounds, lbs.) was measured using a tensile testing device, by forcing the nails through a precisely sized hole in a direction parallel to the nail axis A 14 and measuring the force required to separate the nail 14 from the plastic 12 . The nails that were pre-heated prior to molding were heated to a temperature of about 500° F. to 550° F., after which the plastic was molded to the nails. For the post heat treatment, the nails were heated to the temperature shown for a period of about 30 minutes.
As can be seen from Table 1, the difference in plastic shear strength between the non-pre-heated nails and the preheated nails is quite significant. For the present maleic anhydride modified polypropylene, the difference is a factor of over 15 (71.0 lbs./4.6 lbs.) without post molding heat treatment. With post molding heat treatment, the shear strength increased by a factor of almost 3 over the non-post heat treated (pre-heated) nails. The plastic shear strength was shown to be about 71.0 lbs with pre-heating the nails prior to molding the plastic to the nails. In no case did a cold-applied plastic approach the shear strength of the pre-heated nail strips.
It was observed that nails strips formed in accordance with the present invention exhibited a very limited amount of debris compared to known plastic collations, principally because the plastic remained on the nail shank and penetrated the substrate (wood) with the nail. Moreover, it was found that the debris that was generated was in the form of a finer material (smaller sized particles) so there was less of a housekeeping issue with the debris that was generated.
Debris was collected from samples of nails to determine the “debris performance”, or reduction of debris generation of the present collation system. The amount of loose debris was measured by first weighing a given collated nail strip consisting of 10 nails. The starting weight of plastic was calculated by subtracting the weight of 10 uncollated nails from this amount. The test nail strip was then fired into a substrate (e.g., wood board) surrounded by an enclosure to facilitate the capture and collection of the loose debris. The collected loose debris was then weighed and divided by the original starting plastic amount to yield the percent loose debris for a particular plastic collation material.
Table 2, below, summarizes the results obtained with selected three of collating plastic materials (a non-adhesive polypropylene material, an adhesive material in accordance with the present invention that was formulated as a blend of 50 percent by weight polypropylene and 50 percent by weight of the maleic anhydride modified polypropylene, and a formulation of 100 percent of the maleic anhydride modified polypropylene). Firing tests were conducted in both pine and medium density fibreboard (MDF) substrates.
TABLE 2
DEBRIS GENERATED FROM VARIOUS
PLASTIC NAIL COLLATIONS
% Loose Debris
% Loose Debris
Plastic collating material
(Pine)
(MDF)
Non-adhesive polypropylene
86
91
Polypropylene/maleic anhydride
17
14
modified polypropylene blend
(50%/50% by weight)
100% maleic anhydride modified
0
0
polypropylene,
It was also found that the nails carried the plastic into the wood and that the plastic was embedded in the wood with the nail. In fact, surprisingly, this increased the nails' holding power in the wood. It is believed that this was due to the adhesive nature of the plastic as it embedded in the wood, in conjunction with the adhesion of the plastic to the nail. That is, it is believed that the plastic (adhesive) flowed into the wood structure and bonded with the wood structure, thus providing even greater holding power.
Table 3 below shows the results of evaluations that were conducted to compare the holding power or withdrawal strength of nails that were “fired” into wood from nail strips in accordance with the present invention to non-pre-heated polypropylene or control molded nail strip collations. The withdrawal strengths were measured as the force (in lbs/in of withdrawal) required to pull the nail from the wood. The values were normalized (e.g. calculated per inch of withdrawal) by dividing the force by the penetration depth.
TABLE 3
PENETRATION AND WITHDRAWAL STRENGTH OF NAILS
CARRIED IN VARIOUS PLASTIC NAIL COLLATIONS
Withdrawal
Strength
Plastic
Sample
Standing
Penetration
Ultimate
(lbs./in. of
Collation
No.
Ht. (in)
(in)
(lbs)
withdrawal)
Material
1
0.258
2.432
408.73
168.06
Tymor ™
2
0.585
2.415
372.28
154.14
Tymor ™
3
0.618
2.382
150.06
63.00
Control
4
0.616
2.384
150.93
63.31
Control
5
0.621
2.379
231.86
97.46
Admer ®
6
0.644
2.356
127.87
54.27
Control
As can be seen from the data of Table 3, nail strips in accordance with the present invention exhibited considerably higher withdrawal strengths compared to non-adhered (control) nails. The control nails exhibited withdrawal strengths of about 54.3 to 63.3 lbs, whereas the preheated nails exhibited withdrawal strengths of about 97.5 to 168.1 lbs. In each case, the pre-heated nails required almost 54 percent greater force to withdraw or pull out the nails. At the same time, the nail penetration was essentially equal to that of the non-preheated nails. The Admer® and Tymor™ materials are both maleic anhydride modified polypropylene.
In the present nail strips 10 , the plastic is a uniform material that is molded over the nail shanks 16 and between the nails 14 . It will be appreciated that the plastic material can be a multi-part molding, in which discrete layers in the molding (collating) material are provided on the nails. In such a system, an adhesive can be applied or bonded to the nails onto which a layer of a material with desired characteristics (e.g., a stiffer or more rigid material or a more impact resistant material) is applied. Alternately, of course, a layered configuration can be achieved using a coextrusion of two or more plastics.
Another aspect of the present nail strip 10 is the shape or configuration of the molding around and between the nails 14 . That is, the shape of the collars 20 and the connecting portions 22 . In a present strip 10 , the collars 20 are formed as encircling elements that have a greater longitudinal or axial length at about a midpoint L 20M between the connecting elements 22 (that is at about the midpoint of the circle inscribed by the nail), and dip to a smaller axial length at about the connecting portions L 20C .
The connecting portions 22 include a bridge 24 that extends from one collar 20 a to the adjacent collar 20 b and is about the height H 22 of the collar 20 at the collar 20 /connecting portion 22 juncture. The bridge 24 is a relatively long, thin element that in fact “bridges” the two adjacent collars 20 a , 20 b . A rib 26 runs along the bridge 24 from one collar 20 a to the next 20 b . The rib 26 is a cross-piece to the bridge 24 and has a low profile (e.g., is short) in the nail axial direction or along the length of the nail (i.e., has a low thickness t 26 ), but has a greater depth or width w 26 than the bridge 24 . As seen in FIGS. 2 and 3 , the cross-section of the bridge 24 and rib 26 is cruciform-shaped, and with the 26 rib serving as the cross-piece, the rib 26 resides at about the middle of the bridge 24 . A cross-section taken through the nails 14 (see, FIG. 3 ) that provides a top or bottom view of the connecting portion 22 shows that the rib 26 actually has a concave shape as it extends between the nails 14 . Both the bridge 24 and the rib 26 are formed having rounded ends, as indicated at 28 .
As will be appreciated by those skilled in the art, when a nail 14 is driven from the strip 10 , it is the nail 14 , the collar 20 and the connecting portion 22 between the driven nail 14 and the next adjacent nail 14 b (see right-hand side of FIG. 1 ) that are separated from the strip 10 . Desirably, this entire “assembly” is driven into the substrate, and it will be understood that it is desirable to drive as much of the assembly as possible into the wood to, among other things, reduce the amount of debris that is generated.
To effect separation of the connecting portion 22 , a notch 30 can be formed at the base or bottom 32 of the connecting portion 22 along a desired line of separation, or at the juncture of the connecting portion and the next adjacent nail. This provides a location at which the nail 14 , collar 20 and connecting portion 22 , as a unit, separate from the strip 10 .
The connecting portion 22 provides the necessary rigidity to the strip 10 that, in conjunction with the adhesive characteristics of the plastic, prevents corrugation of the strip 10 . Nevertheless, even with the increased adhesion and rigidity, that no significant increase in force is needed to drive the nail 14 and separate the nail 14 from the strip 10 .
In a present nail strip 10 , the upper and lower collations 12 a,b have essentially equal dimensions. The collar 20 has a length L 20M , L 20C of about 0.360 inches to 0.480 inches and a thickness t 20 of about 0.005 inches to 0.015. The bridge 24 has a length l 24 of about 0.280 inches to 0.420 inches and a thickness t 24 of about 0.006 inches to 0.014 inches and the rib 26 has a thickness t 26 of about 0.045 inches to 0.060 inches and a width w 26 of about 0.087 inches to 0.128 inches. It will be appreciated that because the rib 26 has a concave shape, the width w 26 varies along the length of the rib 26 .
Referring to FIG. 4 , the collar 120 can be formed having a taper or a thinned region 122 at the collar portion 124 closest to the tip 34 of the nail 14 or at the leading end of the collar 120 . The collar 120 expands or thickens toward the trailing end 126 . It has been observed that this taper 122 facilitates penetration of the nail 14 and plastic collar portion 120 into the wood. The taper 122 is preferably formed at an angle β relative to the longitudinal axis A 14 of the nail 14 , of about 0.5 degree to about 5.0 degrees, and most preferably about 1.0 degrees. The taper 122 forms a wedge 128 that assists penetration of the nail 14 into the substrate and can further enhance the withdrawal resistance. It should, however, be recognized that the angle β cannot be too great in that the wedge 128 could serve to split the wood.
It has also been observed that the location of the collar 20 on the shank 16 contributes to increasing the penetration of the nail 14 into the wood. Specifically, it has been found that positioning the collar 20 closer to the tip 34 of the nail 14 results in increased nail penetration. It is believed that because the collar 20 (which is an interference to penetration) is positioned closer to the nail tip 34 , the greatest interference (that is as the collar 20 is entering the wood) is encountered while the impulse from the nail driving tool is high. Accordingly, the greatest resistance to penetration is overcome while the impulse from the tool is high, and, as such, penetration of the nail is greater when the collar 20 is positioned close to the nail tip 34 rather than farther back on the nail shank 16 , near to the nail head H.
An evaluation of the effect of the collar 20 position on the shank 16 was conducted. Using a nail 14 that was 3 inches long and 0.131 nominal diameter, with a collar length L 20M of 0.5 inches and a thickness t 20 of about 0.020 inches and a collation material of maleic anhydride modified polypropylene (Admer®) and a pneumatic driving force of 90 psi, it was found that a nail 14 having a collar 20 positioned 2.25 inches from the tip 34 was driven (had a penetration of) 2.45 inches, a nail 14 having a collar 20 positioned 1.5 inches from the tip 34 was driven 2.75 inches, a nail 14 having a collar 20 positioned 0.5 inches from the tip 34 was driven 2.975 inches, and a bare nail 14 was driven 2.925 inches
It will be appreciated by those skilled in the art that the use of a forward positioned collar 20 (or more generally a forwardly positioned collation element or support) is not limited to use with a collated nail strip 10 . Rather, such an arrangement can be used with other strip formed fasteners and other strip-formed consumables.
FIGS. 5A and 5B illustrate an embodiment 210 in which the ribs 226 are formed at an angle γ and γ′ relative to an axis A 210 of the strip 10 (as opposed to the ribs 26 in the embodiment of FIG. 1 which are generally parallel to the axis A 10 ).
FIGS. 6 and 6A illustrate an alternate embodiment of the plastic nail collation 310 in which an embossed pattern 324 is formed in the connecting portion 322 of the strip 310 , rather than the bridge 24 and rib 26 configuration (of FIGS. 1-5 ). In the embossed pattern 324 embodiment, a pattern of ribs 326 is formed in the connecting portion 322 that can extend in one or both directions relative to a plane P 322 that is defined by the connecting 322 portion extending between the collars 320 (e.g., into or out of or both into and out of the plane P 322 defined by the connecting portion 322 and the adjacent nails 14 a,b ). A cross-section of a one-directional embossing 324 is illustrated in FIG. 6A . The embossing 324 serves to provide a three-dimensional structure, much like the bridges 24 and ribs 26 , to enhance the rigidity of the strip 310 . In addition, it is anticipated that the embossing 324 can provide the necessary rigidity and predictability in separation while at the same time, reducing the amount of material needed to form the strip 310 . A rib 325 can be used with the embossed collation embodiment 310 , as well. The embossing can also be formed in the collar.
It will be appreciated by those skilled in the art from a review of the drawings that the present collation can be used with a coiled nail collation (see, FIG. 1B , which shows a coiled nail strip 10 ′) as well. In such an arrangement, the collation is formed with a bridge connecting the collar portions, however, a reinforcing or stiffening element (e.g., rib) is not used so that the strip can be coiled. In such an arrangement, the collations can be such as those shown in FIGS. 11A and 11E , in which the connecting portions 822 , 1822 include bridges 824 , 1824 , but no ribs. This permits the flexing of the collations as necessary to roll or coil the collation.
Referring to FIGS. 7A and 7B , it has been found that the amount of debris that is generated when the nail 14 is driven from the strip 10 is reduced when the nail connecting portion 22 is separated as close as possible to the next trailing nail 14 b ( FIG. 7B ). Comparing FIGS. 7A and 7B , it can be seen that debris is reduced when the driven nail 14 a is separated from the strip 10 with as much of the trailing connecting portion 22 b as is practical. This is to reduce the opportunity for the downward moving head H 14a of the driven nail 14 a to contact and tear (actually, a better description is strip) the connecting portion 22 from the connecting portion 22 that remains. It will be appreciated that if the connecting portion is 22 separated as far from the driven nail 14 a as possible, then little to nothing will remain for the nail head H 14a to contact and tear from the connecting portion 22 (see for example FIG. 7B ). It has been found that the portion of the connecting portion 22 that remains connected to the driven nail 14 a , that is the trailing connecting portions 22 b , are sufficiently strong to remain intact and attached to the nail 14 a as the nail 14 a is driven into the substrate.
In order to provide this selectively or preferentially located separation region, a number of configurations have been examined. One such configuration is to include the notch 30 as seen in the embodiment 10 of FIG. 1 and as seen in FIGS. 8A and 8B . To effect separation of the connecting portion 22 as close to the trailing nail 14 b as possible, the notch 30 should be positioned as close to the trailing nail 14 b as possible.
Essentially, the strip 10 is configured with a weakened region so that separation is influenced or encouraged at a desired location. However, it should be noted that it is desirable to have the remaining portion of the connecting portion 22 remain intact as the nail 14 a is driven into the substrate to reduce the debris generated. Accordingly, as seen in FIG. 8B , the notch 30 can be configured with a semi-circular notch wall 30 a , and may also include a lower notch 30 b to further influence separation location.
Another embodiment of the strip 410 can be configured so that separation is influenced by selectively thinning areas at which separation is desired. For example, in FIG. 9A , the bridge 424 is thinned at the trailing nail 14 b collar 420 (the desired separation location) by forming a small radius transition (indicated generally at 423 ) between the bridge 424 and the collar 420 b or the trailing nail 14 b and maintaining a larger radius transition (indicated generally at 425 ) between the bridge 424 and the leading nail 14 a (the nail to be driven) collar 420 a . The smaller radius transition is about 0.015 to 0.025 inches, whereas the larger transition radius is about 0.050 to 0.060 inches.
The larger radius transition 425 results in more material being present at the leading nail collar 420 a /bridge 424 transition. This in turn influences separation to occur closer to the transition between the bridge 424 and the trailing nail 14 b (the smaller radius area with less material). In FIG. 9A the nails 14 a , 14 b and the connecting portion 422 are shown (with the nail heads H 14a and H 14b shown in phantom lines) to illustrate that the head H 14a of the leading nail 14 a is at about the same location as, e.g., overlying, the thinned bridge region 423 . As such, the connecting portion 422 (that is, the bridge 424 and rib 426 ) is not struck by (or minimally struck by) the nail head H 14a as it is driven from the strip 410 . This, as will be appreciated by those skilled in the art, will reduce the amount of debris generated.
Another embodiment 510 is illustrated in FIG. 9B , which shows a variation on the large radius/small radius configuration in which the axes A 14a , A 14b of the nails 14 a , 14 b are offset (or eccentric) relative to the axes of the collars 520 a , 520 b . In this embodiment, the nails are offset to establish a thinner collar region at the smaller radius juncture. This further influences or encourages separation as close as possible to that juncture (as indicated at 523 ).
In still another embodiment illustrated in FIGS. 9C and 9D , the thinned region 1423 is provide at the trailing nail 14 b transition by forming a small radius region (about 0.010 to 0.018 inches compared to the leading nail radius region 1425 of about 0.060 inches) that defines a neck region 1428 . The neck can have a thickness t 1428 of, for example, about 0.0070 inches.
Other embodiments of the nail collation 610 , 710 , respectively, are seen in FIGS. 10A and 10B , in which the connecting portion 622 includes a thin bridge 624 with a relatively stiff rib 626 extending between the collar portions 620 ( FIG. 10A ) or even no bridge with a relatively stiff rib 726 extending between the collar portions 720 ( FIG. 10B ). The rib 726 can be dimensioned so that the width w 726 is greater than the width w 720 of the nail 14 and collar 720 (that is, measure across the collar 720 ).
To further enhance the ability of the nail to penetrate the substrate, while maintaining a high level of confidence of the structural integrity of the plastic collations, the various structural portions of the connecting portion 22 can be tapered. As seen in FIG. 11A , the connecting portion 822 can be formed with a bridge 824 that tapers outwardly from the leading edge 827 (the edge to first enter the substrate) to the trailing edge 829 . As seen in FIG. 11E , the tapered connecting portion 1822 can be inverted relative to that shown in FIG. 11A . It is anticipated that both of the rib-less configurations, those shown in FIGS. 11A and 11E will be particularly well suited for coiled applications ( FIG. 1B ). Alternatively, as illustrated in FIG. 11B , the rib 926 can be tapered with straight bridge section 924 , or, with a tapered bridge section 1024 ( FIG. 11C ). The rib 1226 can be tapered on both the upper and lower ends, preferably at an angle γ of about 45 degrees, with or without a tapered bridge 1224 ( FIG. 11D ), to provide increased stiffness and less debris. The rib 1226 can have a thickness t 1226 of about 0.070 inches and the bridge 1224 can have a thickness t 1224 of about 0.013.
As seen in FIG. 12 , another way to reduce the amount of debris generated is to reduce the size (width) of the lower collation 1112 b . In the illustrated embodiment, the lower collation 1112 b width w 1112b is about ½ of the width w 1112a of the upper collation 1112 a.
FIGS. 13A and 13B illustrate an embodiment 1310 of the strip in which the nails 1314 a,b include rings or serration-like formations 1320 that extend outwardly from the nail shanks 1316 , beyond an outer periphery of the shank 1316 . The formations 1320 facilitate creating an enlarged opening in the substrate to ease penetration of the collation material 1322 into the substrate, without creating debris. Essentially, the rings or serration-like formations 1320 tend to further expand the opening the substrate to allow for lower-stress penetration of the collation material 1322 .
FIGS. 14A and 14B illustrate yet another embodiment 1410 in which the nail 1414 have deformations 1420 in the shanks 1416 under the collation material 1422 . The deformations can be formed as rings, abraded or roughened regions, or the like, to increase adhesion of the material 1422 and the shank 1416 .
FIGS. 15A and 15B illustrate still another embodiment of the nail collation 1510 . In this embodiment, the rib 1526 is formed at or near the top of the bridge 1524 . In a present embodiment, the rib 1526 has a tapered shape, narrowing toward the tip 34 of the nail 14 a . Again, this promotes penetration of the entirety of the nail 14 a and the collar 1520 (and portions of the bridge 1524 and rib 1526 , as appropriate) into the wood, to further minimize generation of debris. It has been found that following molding of the collation 1512 , the rib 1526 tends to cure into the tapered shape as well. It will be appreciated that the shape of the rib 1526 can be as shown (a diamond-like shape) or any of a side variety of shapes, including but not limited to those illustrated herein. The bridge 1524 and rib 1526 are formed integral with the collar 1520 (the entirety of the collation system 1512 is formed as an integral system). The other features described above, such as the weakened or selectively weakened regions, thinned areas and the like can also be incorporated into this embodiment.
In each of these embodiments, the collation is configured so as to minimize or eliminate corrugation while at the same time, to reduce the amount of debris generated when the nail 14 a is driven into the substrate.
All patents referred to herein, are incorporated herein by reference, whether or not specifically done so within the text of this disclosure.
In the present disclosure, the words “a” or “an” are to be taken to include both the singular and the plural. Conversely, any reference to plural items shall, where appropriate, include the singular.
From the foregoing it will be observed that numerous modifications and variations can be effectuated without departing from the true spirit and scope of the novel concepts of the present invention. It is to be understood that no limitation with respect to the specific embodiments illustrated is intended or should be inferred. The disclosure is intended to cover by the appended claims all such modifications as fall within the scope of the claims. | A fastener assembly is for use in an associated fastener driving tool. The assembly includes a row of fasteners arranged substantially parallel to each other. Each fastener has a shank and defines an axis. A collation system is formed from a plastic material that is molded onto and adhered to the fasteners. The plastic material defines a collar portion at least substantially encircling the fastener shank and a connecting portion extending between and connecting adjacent collar portions. The connecting portion includes a bridge and a rib. The bridge is a relatively thin, elongate element spanning adjacent collar portions and the rib is a relatively thick, short element that is disposed at about an upper portion of the bridge. When the fastener is driven from the driving tool, the collar portion remains adhered to the fastener such that the collar portion penetrates the substrate with the fastener. The connecting portion can include a weakened region for separating the connecting portion from the collar. | big_patent |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is the national stage of International Application NO. PCT/ES2012/000275, filed Oct. 31, 2012, and claims priority of European Patent Application No. 11380089.0 filed Oct. 31, 2011, both of which applications are incorporated by reference herein in their entirety.
TECHNICAL FIELD OF THE INVENTION
[0002] This invention relates to devices for applying sealants such as silicones and the like in multiples artifacts or machines such as automobiles, trains, ships and aircrafts, therefore, it is useful in diverse industries such as aviation, automotive, naval, railway, and robotics or similar industries. More particularly, the invention is directed to a nozzle, comprising a bell or hood lower section that is coupled in a non-permanent manner to an injection button with a particular design, which is highly useful in applying silicone and similar sealants on said artefacts and machines.
BACKGROUND OF THE INVENTION
[0003] The manufacturing of machines and other related artefacts or accessories in several industries, such as aviation, automobile, naval, railway, robotics and the like requires processes wherein it is necessary the application of silicones and similar or related sealants to said machines or artefacts, particularly during its manufacture processes. Sealants application requires the use of nozzles in order to apply said sealants to the machines or artefacts from a sealant-container, such as cartridges or injection machines. Thus, the sealant may be applied with a nozzle manually and directly from cartridges filled with sealant, or by an extrusion or manual gun, as those currently available in the market and known in the art. Some of the nozzles known in the art are made of metal and are intended to be reusable; particularly those meant to be used in injections machines, thus they must be cleaned up with solvent or products specifically prepared for such cleaning purpose. Such solvents or cleaning products are hazardous, abrasive and highly irritant to the skin. Furthermore, the design of said nozzles does not allow their use with both manual cartridges and automatic processes using injection machines, nor they have a precision dispersion of the sealant as required in, for instance, sealing operations involving injecting sealants in the chamfers in which rest the heads of rivets and screws or in the walls of orifices, wherein highly precise sealant application is needed and required.
OBJECTS AND SUMMARY OF THE INVENTION
[0004] The above drawbacks and needs are overcome by a nozzle for applying sealants with a bell or hood lower section and an injection button as described herein, which provides several advantageous and novel characteristics for its intended function inherent to its innovative organization and construction, which will be described in detail further below, and which represents a considerable improvement with respect to what is currently known in the market in its field of application.
[0005] One of the main the objective of the invention is to provide a nozzle that once it is connected to a cartridge or injection machine, facilitates the injection of silicone or other sealants in multiple industrial applications. Another objective of the invention is to provide a nozzle having an outlet shaped as a bell or hood in order to facilitate the encapsulation of rivets or screws, particularly applicable in the aeronautical industry, having the innovative characteristic that it also has an injection button coupled to the end section of said bell or hood, said button having a special design with a number of channels and orifices for carrying out sealing operations with greater accuracy, allowing to guide the injection of the sealant around the rivets and nuts. In yet another objective of the invention is to provide a nozzle having a button section that by its particular design substantially improving the encapsulation and providing an optimum sealing of rivets and nuts, and that allows the user to apply sealant operations both manually and by automated sealant injection machines. In still another objective of the instant invention is to provide a nozzle having a bell or hood lower section for sealing rivets and nuts, which may be used in the aviation industry and the automotive, naval, railway and robotics industries.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] The foregoing and additional features and characteristics of the embodiments of the present invention will become more apparent from the following detailed description considered with reference to the accompanying drawings, which are used herein in a manner of example only, and wherein:
[0007] FIG. 1 shows a diagrammatic representation in perspective view of an example of one preferred embodiment of the nozzle for applying sealants, according to the instant invention, said representation illustrating general outer configuration, and its main parts or elements.
[0008] FIG. 2 shows a cross sectional view along a longitudinal axis of the nozzle according to the invention already shown FIG. 1 .
[0009] FIG. 3 shows a diagrammatic illustration of the plan view of one preferred embodiment the injection button incorporated in the nozzle according to the instant invention.
[0010] FIG. 4 shows a diagrammatic representation of an enlarged view of section 11 on FIG. 2 , wherein the detail of the configuration of the coupling or matching between the bell-shaped tip or lower section of the nozzle and the injection button is illustrated.
[0011] FIG. 5 shows a diagrammatic representation in perspective view of an example of another embodiment of the nozzle for applying sealants, according to the instant invention, said representation illustrating general outer configuration, and its main parts or elements and comprising a button comprising lateral outlets or openings.
[0012] FIG. 6 shows a cross sectional view along a longitudinal axis of the nozzle according to the invention already shown FIG. 5 .
[0013] FIG. 7 shows a diagrammatic illustration of the plan view of a second preferred embodiment of the injection button incorporated in the nozzle according to the instant invention, already illustrated in FIGS. 5 and 6 , wherein such button comprises lateral outlets or openings.
[0014] FIG. 8 shows a diagrammatic representation of an enlarged view of section 31 on FIG. 6 , wherein the details of the configuration of the coupling or matching between the bell-shaped tip or lower section of the nozzle and the injection button of the embodiment illustrated in FIG. 5 are illustrated.
DETAILED DESCRIPTION OF THE INVENTION
[0015] The following detailed description illustrates the invention by way of example and is not limited to the particular limitations presented herein as principles of the invention. This description is directed to enable one skilled in the art to make and use the invention by describing embodiments, adaptations, variations and alternatives of the invention. Potential variations of the limitations herein described are within the scope of the invention. Particularly, the size and shapes of the invention's elements illustrated in the discussion may be varied and still provide embodiments having different sizes or geometric shapes, that are within the scope of the instant invention.
[0016] The instant invention is directed to a nozzle for applying silicones and similar sealants, said nozzle comprising a bell or hood shaped tip and an injection button, which provides several advantageous and novel characteristics for its intended function inherent to its innovative organization and construction, which will be described in detail further below, and which represents a considerable improvement with respect to what is currently known in the market in its field of application.
[0017] A first embodiment of the invention is illustrated in FIG. 1 wherein the nozzle embodiment 10 is illustrated. FIG. 2 illustrates a diagrammatically representation of a cross sectional view of nozzle 10 . The nozzle 10 comprises a main elongated hollow body 12 having a truncated cone shape. Said elongated body 12 comprises a first end 14 and a second end 15 . First end 14 has a wider diameter that second end 15 .
[0018] Physically connected to first end 14 , nozzle 10 comprises connecting hollow round section 16 , which comprises a threaded exterior surface 17 , which allows nozzle 10 to be connected to a silicone or similar sealant cartridge or injection machine. Said threaded section thus allows the coupling of nozzle 10 to most cartridges or machines present in the market, adding versatility in the manner that nozzle 10 is used. Connecting section 16 also comprises protruding ring 18 , which is surrounding the end of said connecting section 16 that is in direct physical contact with said first end 14 of the main elongated body 12 . Protruding ring 18 stops against the cartridge or gun to which nozzle 10 is coupled, as it is the union between the nozzle 10 and the cartridge thus providing or establishing a precision adjustment of nozzle 10 to the sealant container cartridge or injection machine.
[0019] At the second end 15 , nozzle 10 comprises a bell or hood shaped section 19 , physically connected to the second end 15 of said main elongated body 12 . As illustrated in cross section, along a longitudinal axis or line of the nozzle 10 in FIG. 2 , at its peripheral end, bell shaped section 19 has an annular flanged section 21 .
[0020] Bell shaped section 19 is sized to encapsulate rivets or nuts in order to cover them completely with the sealing material and provides a connection element discussed below in detail. Main elongated body 12 , round connecting section 16 and bell shaped section 19 may constitute a single unit, physically connected.
[0021] Connected to the peripheral annular flanged section 21 of the bell-shaped section 19 , nozzle 10 also comprises injection button 22 , which is diagrammatically illustrated in FIG. 3 . It comprises a circular main body 23 and a peripheral groove section 26 around the end of said circular main body 23 . On its front surface, injection button 22 comprises hollow central circular protrusion 27 , which is projected from said main body 23 , and multiple series of radially oriented channels 28 ending in orifices 29 which are distributed around said central circular protrusion 27 .
[0022] As illustrated diagrammatically in FIG. 4 , which illustrates section 11 , the annular flanged section 21 of the bell shaped section 19 cooperatively match with the peripheral groove 26 of injection button 22 , allowing a strong and firm non-permanent connection or coupling of button 22 to the bell shaped section 19 . Once coupled to the bell-shaped section 19 , the button 22 covers the exit or mouth of bell shaped section 19 .
[0000] The whole structure of nozzle 10 is preferably made of plastic, preferably of polypropylene.
[0023] FIGS. 5 to 8 diagrammatically illustrate a second preferred embodiment 30 according to the invention. Embodiment 30 is similar to embodiment 10 since both embodiments comprise a main elongated hollow body 12 having a truncated cone shape; a hollow round and threaded section 16 and a bell or hood shaped section 19 wherein said main parts have the same elements already described previously and wherein the said sections are connected as previously described as illustrated particularly as illustrated in FIGS. 5 and 6 . However, second embodiment 30 comprises injection button 32 in place of injection button 22 . As described previously regarding injection button 22 injection button 32 as illustrated diagrammatically in FIGS. 5 , 6 7 and 8 and particularly in FIG. 7 , comprises a circular main body 23 having a peripheral groove section 26 around the end of said circular main body 23 . On its front surface, injection button 32 comprises hollow central circular protrusion 27 , which is projected from said main body 23 and also comprises multiple series of radially oriented channels 28 ending in orifices 29 which are distributed around said central circular protrusion 27 . Contrary to injection button 22 , nonetheless and as illustrated in FIG. 7 , injection button 32 comprises a series of lateral grooves or openings 34 , located around the lateral sides of said central circular protrusion 27 .
[0024] As in the case of embodiment 10 , and has illustrated diagrammatically in FIG. 8 , which shows the detailed view of section 31 in embodiment 32 , the annular flanged section 21 of the bell shaped section 19 cooperatively match with the peripheral groove 26 of injection button 32 , allowing a strong and firm non-permanent connection or coupling of button 32 to the bell shaped section 19 . Once coupled to the bell-shaped section 19 , the button 32 covers the exit or mouth of bell shaped section 19 .
[0025] In operational terms, the nozzle according to the instant invention may be coupled or connected to most cartridges or machines containing sealant which are present in the market or commercially available by threading connecting hollow round section 16 to the sealant containing cartridge or injection machine. The protruding ring 18 acts as a stopper in the insertion or threading of the cartridge and reinforces the area of greatest pressure, which is the union between the nozzle and the cartridge, allowing the achievement of precision adjustment. The sealant then may enter to the interior of the main hollow elongated conical body 12 via threaded hollow section 16 , which is the sealant inlet point of the nozzle herein described. From the central section of the main hollow elongated body 12 , the sealant is expelled out of the nozzle via the bell or hood shaped section 19 , which acts as the sealant outlet point. The shape of bell shaped section 19 being meant for encapsulating rivets or nuts in order to cover them completely in the sealing material. Once the sealant is expelled from the bell shaped section 19 , it most moves out through injection bottom 22 , which is fitted or coupled in a strong but non-permanent manner to the bell shaped section 19 . Due to said non-permanent coupling, button 22 may be fitted to or remove from bell shaped section 19 at the user's will. The particular design of this button, with channels 28 and orifices 29 , allows executing different precision sealing operations. Specifically, it allows directing the flow of sealing material in two different ways: (1) towards the chamfers in which the rivet heads are adjusted, by means of the series of radially positioned channels 28 , that lead to through orifices 29 located at annular area 27 of the central part of the button or alternatively, and (2) when using injection button 32 , towards the walls of the orifice in which the screws are inserted, by means of lateral outlets 34 provided in an alternative embodiment of the button 32 , which has a hollow central part 27 . In this manner, the plugging of the orifice in which the screw is inserted is prevented, which is important in order to allow its subsequent riveting.
[0026] The sealant applying operations are performed after drilling orifices in the various claddings or parts to be joined, by a riveting that will consequently be fast, clean and uniform, since the appropriate doses of sealant have been applied at the specific points described, as enabled by this system.
[0027] The application of the sealant with the nozzle according to the instant invention may be performed either manually, by cartridges filled with silicone or other sealing materials, or by an extrusion or manual gun, as those currently available in the market. The used of the nozzle according to the invention in applying sealants provides a perfect seal from air and oxidising liquids, which is very important for the pressurisation and lifetime of aircrafts, ships, trains or automobiles.
[0028] Finally, it is worth mentioning that once the aforementioned sealing operations are performed, simply cutting the anterior part of the nozzle with a bell shape, a traditional truncated-cone shaped nozzle is obtained that may be used to apply sealing cords, filler sealant or safety cords that ensure that there is no liquid between two parts joined by rivets and leaving fully sealed the fuel tanks or other elements made from parts joined by rivets. Therefore, the nozzle according to the instant invention disclosed herein provides a device that simplifies the sealing work in both the aesthetic appearance and speed of execution, thus, reducing the sealant application time. As a consequence, the herein disclose nozzle reduce the sealant application time, thus saving time and labour, provides a more economical sealing process and increases the quality of the resulting sealant application simultaneously.
[0029] While the invention has been described in conjunction with some embodiments, it is to be understood that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the forgoing description. Accordingly, the invention is intended to embrace all such alternatives, modifications and variations falling within the spirit and scope of the appended claims. | A nozzle that includes a connecting section, a main hollow elongated and conical body, a bell shaped section and an injection bottom is described. The design of the connecting section allows it to be connected to injections machines or to a sealant containing cartridges. The injection button is non-permanently connected to the bell shaped section and it has a circular central protrusion, a series of radially oriented channels ending in circularly positioned openings, which facilitates the direction of the expelled sealant. Alternatively, the button may also include lateral grooves at the walls of the central circular protrusion. The particular design of the injection button allows an efficient and highly accuracy distribution of the sealant on the surfaces and selected parts of machines and artifacts wherein the sealant is applied. | big_patent |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] [0001]This application claims the benefit of U.S. Provisional Application having Ser. No. 60/524,799 for Offset Compensated Position Sensor, and U.S. Provisional Application having Ser. No. 60/524,919 for Minimized Cross-Section Sensor Package, both having filing date Nov. 25, 2003, the disclosures of which are herein incorporated by reference in their entirety, both commonly owned with the instant application.
FIELD OF THE INVENTION
[0002] The present invention generally relates to sensors, and in particular to position and motion sensors.
BACKGROUND OF THE INVENTION
[0003] Many mechanical systems contain moving parts not directly linked through mechanical means whose position, timing, or speed must be monitored and controlled with correction schemes for safe or efficient operation. A prime example is the operation of diesel engine fuel injectors. These injectors are usually controlled either hydraulically through rapid compression of fuel or electrically through operation of a fast moving solenoid valve. In both systems, the timing and speed of the actual injection of fuel into the combustion chamber greatly depends on the characteristics of the fuel being used. This is especially true of biodiesel fuels that contain various entrained organic materials and gases that make the fuel compressible and change its viscosity or other characteristics that affect valve speed or timing.
[0004] Mechanical systems such as internal combustion engines usually contain a significant number of these moving objects. For instance, there are usually multiples of 4, 6, 8 or more cylinders in diesel engines utilizing fuel injectors each containing a moving valve or other object that must be monitored for efficient or safe operation. Each injector requires a separate sensor. The wiring of these sensors to a remotely located engine monitoring and control system must be designed to accommodate extreme temperatures and vibrations and adds cost and weight to the system. A method of reducing the amount of wires should be employed when implementing these position sensors for maximum efficiency and minimum cost. One widely accepted method of reducing the wiring is to provide output signals in the form of changes in current drawn by the sensor that is directly proportional to the position of the object being monitored. This allows the sensor to operate requiring only two wires; one to deliver operating voltage and current to the sensor and another to provide a ground reference and to form a complete path for the current through the sensor. An example is a sensor that draws zero milliAmperes when the object is at rest and draws 5 milliAmperes when the object is closest to the sensor, with intermediate currents being drawn when the object is between these extremes of movement. These sensors operate by drawing their current through an external resistance inline with their connecting wires such that the resistance develops a dropped voltage level that is directly proportional to the current through the sensor. For instance, connecting a 20-Ohm resistor inline with the 5-milliAmpere sensor listed above results in a varying voltage drop of 0 to 100 millivolts across this inline resistor. This voltage drop is monitored by external devices to convert the current information into voltage information for further processing.
[0005] Mechanical systems such as internal combustion engines also are designed so that the objects that must be monitored are known to be moving within specific limits or windows of timing such that at least some objects are moving at times that other objects are known to be at rest. For instance, the internal combustion engine fuel injectors operate in sequences equally timed in relation to the rotational position of the crankshaft. For instance, injector number one opens between 0 and 25 degrees of rotation, injector number two operates between 50 and 75 degrees, and the like. A method of further reducing the number of wires required for these systems can be employed by multiplexing or connecting all sensors to the same set of wires and a single inline resistor. Since each signal from each individual sensor is known to be occurring within a separate period or window of time, monitoring equipment that also monitors this timing information can know which sensor output is being sampled at any particular time. In the example for the internal combustion engine, a timing signal may be developed from a separate sensor delivering the rotational position of the crankshaft that is used to inform the injector position sensor monitoring system which injector should be operating at any specific rotational position of the crankshaft. This information is used to tag or otherwise mark the pulse train from the monitoring resistor to identify each individual sensor output.
[0006] Position sensors used to monitor these moving objects generate an electrical signal that is proportional to the distance between the moving object and a fixed position. An ideal output signal contains only this information; however, several unwanted electrical signals generally characterized as noise are also usually generated or otherwise transmitted along with the desired position signal. These noise signals are generally divided into either low frequency or into high frequency noise. Higher frequency noise is usually easily filtered out with a low pass filter since the frequency of these noise signals is higher than the frequency of the position signal because moving objects are constrained to velocities that generate signals in or just above the audio or ultrasonic range and because in a well designed sensor these high frequency noise levels are usually several magnitudes in power level below the desired output position signal.
[0007] Most position sensing transducers also generate low frequency noise in the form of a slowly drifting or static DC offset, or error signals that may be a significant portion of the total overall signal. An example of such transducers is a Hall cell where the signal generated is produced by a magnet. The signal from this transducer contains a large DC offset voltage generated by the magnet and a smaller AC signal generated as the target changes the magnetic flux density. Another example is a capacitive or inductive sensor where the slowly changing signal is caused by semiconductor device drift caused by temperature or other changes. This slowly changing or static error signal causes numerous problems in employing two-wire current output position sensors. The generation of any signal current through the sensor causes power to be dissipated inside the sensor. This adds to the temperature of the devices in the sensor, reducing the maximum ambient temperature that the sensor can operate at and reducing overall sensor reliability. The addition of a relatively static or DC current through the output sensing resistor connected to any number of these sensors increases the voltage dropped across the resistor. This leaves less power for the sensors or means that the applied voltage must be increased to generate the required operating voltage for the sensors. This power is wasted and also requires a higher power capability for resistors, by way of example. Also, increased current through the sensor wires means they also must be increased in diameter to accommodate the increased power lost through their series resistance. A further limitation on these type sensors is that especially upon power-up, the sensor should desirably not draw a large amount of current and should automatically calibrate itself so that no excessive current is drawn at any time during its operation. For instance, on vehicles utilizing storage batteries, the initial power-up of these sensors usually occurs at the same time that the battery is being used to crank the engine, reducing the amount of power available to power the sensors.
SUMMARY OF THE INVENTION
[0008] The present invention is directed to sensing position or movement of an object. A position sensor signal conditioner and remotely electrically connected sensor monitoring equipment provide a method of multiplexing multiple numbers of sensors on a minimum number of wires with a minimum of energy required from each sensor monitoring system.
[0009] One embodiment of the invention is herein described as a sensor that may comprise a waveform generator and an error correction generator for modifying a sensing signal by removing unneeded power and providing the signal to a remote monitor via two wires useful in multiplexing multiple sensors. The waveform generator is operable for receiving an unconditioned sensing signal from a transducer and modifying the unconditioned sensing signal in response to an error correction signal for providing a conditioned sensing signal. The error correction generator may provide the error correction signal using a comparator for receiving the conditioned sensing signal and determining a value thereof, a controller for providing first and second timing signals responsive to the value of the conditioned sensing signal, and a signal processor for providing the error correction signal responsive to the first and second timing signals.
[0010] The error correction generator determines and eliminates strong static signals and error signals that do not deliver information about a position of an object being sensed, wherein inclusion of the static and error signals would require energy. One embodiment may include a digitally stored offset and error correction closed-loop compensation circuit for constantly comparing a value of the conditioned sensing signal to a desired minimum value and generates a correction signal that is subtracted from the offset and error signal to deliver a sensor signal output that is close to a desired minimum value. The constant comparing of the sensor signal output to the desired minimum value proceeds in a first direction relative to a direction of sensor output signals generated when an object being sensed moves in a relatively slow manner compared to a nominal speed of objects being monitored such that signals are generated as the objects move are not subtracted from the sensor output to a degree significant enough to cause significant variance between a position of the object and a signal level delivered by the sensor indicating the position. Further, the constant comparing of the sensor signal output to the desired minimum proceeds in a second direction relative to the direction of signals generated when the object being monitored moves in a relatively fast manner compared to the speed of objects being monitored so signals generated by errors or from other noise sources are subtracted from the sensor output in a manner sufficient to allow for a deletion of these error or static signals from being a significant portion of the position signal generated by the sensor.
[0011] One embodiment of the invention may include a window reference circuit that constantly compares a desired conditioned sensor signal output to an existing conditioned sensor signal output and adjusts the conditioned sensor signal output if it is above a preset high reference signal or below a preset low reference signal. The signal processor may generate a relatively small reference signal that is large enough to eliminate small values of drift in a negative going direction yet is small enough not to generate a significant amount of signal due to a discrete nature of calibration voltages from a DAC and counter combination employed thereby. The error correction generator may generate a relatively large reference signal that substantially exceeds the largest voltage encountered by the sensor as an object being monitored moves its maximum amount, allowing rapid recalibration due to sudden changes in an offset voltage caused by rapid temperature or other changes. Yet further, the signal processor may include a DAC and counter combination circuit that contains enough resolution such that even if a sensor offset correction signal is generated as a result of a change in sensor output due to a movement of an object being sensed, the error correction signal is not a significant portion of the conditioned sensing signal representative of a position of the object.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] For a fuller understanding of the invention, reference is made to the following detailed description, taken in connection with the accompanying drawings illustrating various embodiments of the present invention, in which:
[0013] FIG. 1 is a functional block diagram illustrating one embodiment of a position sensor according to the teachings of the present invention; and
[0014] FIG. 2 is a schematic block diagram illustrating one electronic circuit implementation of position sensor of FIG. 1 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0015] The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout, and prime notation is used to indicate similar elements in alternate embodiments.
[0016] With reference initially to FIG. 1 , a position sensor 100 is herein described as including a waveform generator 102 operable for receiving an unconditioned sensing signal 104 S from a transducer 104 and modifying the unconditioned sensing signal responsive to an error correction signal 105 S for providing a conditioned sensing signal 102 S. As will herein de described, a window reference circuit may constantly compare an ideal sensor output to the existing sensor output and adjust the output if it is above a preset large reference signal or below a preset small reference signal. An error correction generator 105 is operable with the waveform generator 102 for providing the error correction signal 105 S. The error correction generator 105 , as herein described by way of example, comprises a comparator 105 A for receiving the conditioned sensing signal 102 S and determining a value thereof, a controller 105 B for providing first and second timing signals responsive to the value of the conditioned sensing signal, and a signal processor 105 C for providing the error correction signal 105 S responsive to the first and second timing signals. A sensor monitoring system 200 may be remotely located for providing power to the sensor 100 and receiving the conditioned sensing signal 102 S via two wires, making the sensor 100 most desirable for multiplexing with other sensors.
[0017] Referring now to FIG. 2 , comparators 116 and 118 , along with a voltage divider network composed of resistors 110 , 112 , and 114 , comprise a window comparator, the comparator 105 A that, along with the controller 105 B including control logic having OR gates 120 and 134 , inverters 122 and 128 , SR Latch 130 , Clock 126 , and divider 132 , control the count rate and direction of the signal processor 105 C including a counter 108 and digital to analog converter (DAC) 106 . The output 105 S of the DAC 106 is subtracted from the output 104 S of the transducer 104 in the waveform generator, herein presented as differential amplifier 102 . The voltage divider network provides reference voltages to the negative pins of comparators 116 and 118 . The reference to comparator 118 is the low end of the window and the reference to comparator 116 is the high end of the window. When the output of differential amplifier 102 is below the window the comparators 116 and 118 and logic system will cause counter 108 to count down at a high rate, providing, via the DAC 106 , a negative going offset to the negative input of differential amplifier 102 , causing its output to go positive. This output will keep going positive until it passes above the low end of the window at which time the comparators and logic will cause counter 108 to count down at a low rate. Counter 108 will count down at a low rate whenever the window comparator input is inside the window from below. A very high ratio between counting up and counting down around the lower edge of the window keeps the signal baseline right at the lower edge of the window when the signal is a pulse train. If the ratio was 1/1 the average pulse height would seek the lower end of the window. If, for some reason, a transient has driven the signal above the window, the comparators and logic will cause counter 108 to count down at a high rate until part of the signal has gone below the window. Thereafter it will only count down at a low rate.
[0018] Upon a rapid increase in sensor voltage on power-up, preset 124 generates a pulse that causes counter 108 and DAC 106 outputs to go to their highest value and the output of differential amplifier 102 to go to zero thereby lowering the current through resistor 136 to zero. Thus upon startup and initial calibration the sensor draws a minimum of current. Also, the sensor can be recalibrated at any time by external means by simply removing and reapplying power.
[0019] The low end of the window set by resistors 110 , 112 , and 114 is just high enough in value to compensate for any offset in comparator 118 that ordinarily might not allow the output of differential amplifier 102 to get below the comparator 118 threshold. This divider network also sets the value of the window on the negative pin of comparator 116 to a level substantially higher than the dynamic signal from the transducer 104 and differential amplifier 102 generated when an object moves or when a parameter being monitored by transducer 104 changes.
[0020] With reference to the controller 105 B, logic may operate in the following manner. If the input to the window comparator 105 A is below a preselected window, the resultant low output from comparator 118 is inverted by an inverter 122 , placing a high signal into the lower input of Or gate 134 and forcing its output high which connects the wiper of switch 138 to a FastCLK pin of divider 132 . At the same time, since the inputs to both comparators 116 , 118 are low, both inputs to Or gate 120 are high which causes counter 108 to count down rapidly, causes the output 105 S of DAC 106 to fall, and causes the output 102 S of differential amplifier 102 to rise. When this output 102 S rises above the lower edge of the window comparator 118 , it goes high forcing the output of Or gate 120 high and the output of inverter 122 low and consequently the output of Or gate 134 low, changing connecting switch 138 to a SlowCLK pin. Counter 108 now counts down at the slow rate until the output of differential amplifier 102 goes below the window and the process continues to cycle. Generally, the slow clock signal will be used for error correction when a transducer output signal is anticipated, and a fast clock signal used for an error correction when noise and only error signals are expected.
[0021] When a sensor system baseline from differential amplifier 102 is in a desired position with all offset corrected, the high end of the window generated by the resistor network is significantly higher in value than a normal dynamic signal from differential amplifier 102 caused by a changing magnetic field.
[0022] As the object or process being monitored increases the output of differential amplifier 102 , the components of the sensor operate to begin increasing the output of the DAC 106 in order to compensate for an increase in value. However, the rate of clock 126 is chosen to be slow enough that a significant number of changes of signal level do not occur during a fast movement of objects being monitored. Also, the number of bits chosen for the operation of the counter 108 and the DAC 106 are such that the increase and decrease in the output 105 S, while the differential amplifier 102 output changes, are not a significant portion of the dynamic signal generated by the transducer 104 when the object being monitored moves. The DAC 106 and counter 108 combination may contain enough resolution such that even if sensor offset correction signal is generated as a result of a change in sensor output due to the movement of the object being sensed, the error correction signal is not a significant portion of the sensor position signal.
[0023] With the sensor 100 , as herein described by way of example, there is a determination and elimination of strong static signals or other error signals that do not deliver information about the position of the object being sensed whose inclusion in the sensor output signal would waste energy. A digitally stored offset and error correction closed-loop compensation may thus constantly compare the sensor output to a desired minimum value and generate a correction that may be subtracted from the offset and error signal to deliver a sensor output that is as close to the desired, an ideal minimum, as is practical without requiring unnecessary circuitry that is typically used for signal conditioning. For the sensor 100 , herein described, the constant comparison of the sensor output 102 S to the desired value, an ideal minimum value, proceeds in a first direction relative to a direction of signals generated when the object (a target) being monitored moves in a relatively slow manner compared to the speed of objects being monitored such that signals are generated as the objects move that are not subtracted from the sensor output to a degree significant enough to cause significant variance between the position of the object and the position signal level delivered by the sensor. The constant comparison of sensor output proceeds in a second direction relative to the direction of signals generated when the object being monitored moves in a relatively fast manner compared to the speed of objects being monitored so that signals generated by errors or from other noise sources are subtracted from the sensor output in a manner sufficient to allow for a deletion of these error or static signals from being a significant portion of the position signal generated by the sensor.
[0024] By way of further example, in operation, the sensor 100 may generate a relatively small reference signal that is large enough to eliminate small values of drift in a negative going direction yet is small enough not to generate a significant amount of signal due to the discrete nature of the calibration voltages from the DAC and counter combination. A relatively large reference signal that may substantially exceed the largest voltage encountered as the object moves its maximum amount is accommodated by allowing rapid recalibration due to sudden changes in offset voltage caused by rapid temperature or other changes.
[0025] With reference again to FIG. 2 , for the embodiment herein described by way of example, the sensor 100 is connected to the sensor monitoring system 200 , external circuitry through a current-to-voltage converter resistor 202 to a power supply 204 . Upon a rapid increase in sensor voltage caused by an inrush of current upon power-up, a preset 124 generates a signal that causes counter 108 to go to its highest value, driving DAC 106 output 105 S to its highest value. The output 105 S of DAC 106 thus drives differential amplifier 102 output 102 S low. A resistor 136 is connected between the output of differential amplifier 102 and system ground 206 through a sensor lead 142 . Thus, upon startup and initial calibration, the sensor 100 draws a minimum of current. For the embodiment herein described by way of example, the resistor 136 converts the voltage output 102 S of the differential amplifier 102 to a current drawn through sensor leads 140 and 142 . This results in a requirement of only two wires to connect the sensor 100 to the external circuitry of the monitoring system 200 . The sensor 100 thus modulates a current across the pair of wires 140 , 142 connected to the sensor monitoring system 200 where the modulated sensor current is converted into a modulated sensor signal voltage.
[0026] If system parameters change suddenly and significantly, causing a large and rapid increase in the output 102 S of the differential amplifier 102 , the voltage at the negative input pin of the comparator 116 is set by the values chosen for resistors 110 , 112 , and 114 to a value higher than the dynamic signal caused by the object moving. In this way movement of the object being monitored does not cause the sensor 100 to attempt a subsequent rapid calibration of the offset level.
[0027] Many modifications and other embodiments of the invention will come to the mind of one skilled in the art having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is understood that the invention is not to be limited to the specific embodiments disclosed, and that modifications and embodiments are intended to be included within the scope of the appended claims. | A position sensor monitors relatively fast moving objects with signal conditioning for reduced power and reduced wiring. A transducer and related circuitry generate a dynamic signal proportional to a position of a moving object and also generate one or more low frequency or static (DC or zero frequency) error signals. The low or zero frequency error signals are removed and a position signal is generated using only two connections to a remote sensor monitor, thus allowing ease in multiplexing and reduced wiring. | big_patent |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority of Provisional Application S. No. 60/276,889 entitled VALVE ACTUATION SYSTEM filed Mar. 16, 2001, which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to valve action in relation to an internal conbustion engine in automobiles and, more particularly, to a desmodromic valve actuation system for intake and exhaust function of a four-stroke piston in such engines.
[0003] Valve action of internal combustion engines is required to control the piston chamber for four functions of intake, compression, combustion and exhaust. The proper timing for opening and closing these valves is extremely critical to effectively and efficiently produce the horsepower for an internal combustion engines. The standard method of controlling and operating these cams is initiated by a timing belt that connects the engine crankshaft to a camshaft. The camshaft has a series of cams, one for each intake and exhaust valve in each cylinder. The cams, as presently configured in all four cycle engines, are designed to displace the valve inwardly to open either the intake port or the exhaust port. The cams are incapable of closing the port openings; and, accordingly, springs, that are compressed when the cams open a port, are energized to provide forces that close the port. The energy merely supplies the force to return the valve to closed position when the energy is released, but the cam provides control of the valve. This control is necessary so that acceleration/deceleration of the valve can be accomplished with minimum impact loading of the valve seat and hence minimize noise. Further, the frequency of cycles for opening and closing of the valve is quite high requiring very high spring loading to accelerate the mass of the valve.
[0004] The four-cycle internal combustion engine requires a first cycle that is the intake wherein a mixture of gas and air enters an opened valve intake port. The piston is displaced vertically down the piston cylinder by the engine crankshaft. The second cycle is compression of the gas/air mixture. The piston is driven up the cylinder by the crankshaft. Both intake and exhaust valves are in a closed position to effectively seal the piston cavity and allow the pressurization of the gas/air mixture. At the appropriate time a spark is introduced to the mixture and an explosion occurs with rapid expansion of the resulting gases. The piston is driven down by the force of the expanding gas which in turn applies a resultant torque to the crankshaft. This torque when combined with a sequence of these explosions at additional pistons will result in the rotational energy of the engine and in its output horsepower. The final cycle is the return up the cylinder by the piston wherein the exhaust valve port is opened and allows gases to escape. At the conclusion of this cycle the next series of cycles is ready to commence by the intake cycle. It can be seen that the valve's closing and opening are essential in the process along with their control in the speed of their action and the duration they remain closed. It is desirable to operate these valves at the highest speed possible for effective and efficient power generation.
[0005] The opening of the valves by the camshaft is a positive mechanical operation by the individual cams. The closing of the valve is a kinematic action resulting from the energy stored in the spring to return and close the valve. This complete function severely limits the speed at which the engine can run, as the valve mass inertia is critical for the stored energy of the spring and limits the cycle time. The acceleration and deceleration of the cam for high cycling conditions can severely limit the size of the spring.
[0006] The normal function in the automobile engine is such that there is a firing sequence for the cyclinders that are constantly repeatable regardless of whether the car is parked or moving at any speed. Accordingly, the same displacement of gas/air mixture is constantly used regardless of speed or stopped. It can be seen that, when stopped, the engine uses much more gas than necessary, when all that is required is to keep the engine running can be accomplished with very minimal amounts of air/gasoline mixture. Power is required for accelerating a vehicle which requires richer mixtures and higher speeds of the engine. If the valves can be controlled during acceleration, efficient and effective volumes of mixture can be ingested in the cylinder for the appropriate condition of speed, thereby offering fuel economy. Finally, when achieving a desired speed it is only necessary to overcome the wind drag forces, the friction of the wheels on the road and the internal friction of the drive train and engine inertia to maintain the velocity. This can be accomplished with less than the total displacement put out by the engine. It would be desirable for effective gas consumption to have the ability to not only control the amount of air/gas mixture entering each piston but also have the ability to close any number of cylinders while the engine is performing with the remaining operational cylinders. Of necessity, the timing is critical for the closing down and reopening of the selected cylinders that become inoperative.
[0007] It is, therefore, the object of the present invention to provide means that will significantly reduce gas consumption of an internal combustion engine as typically found in an automobile by efficiently and effectively controlling valve port openness in concert with the requirements of the operation of a vehicle.
[0008] It is yet another object of the invention to present the means by which valve control is simple, precise and timely, which in turn will be in concert with the engine performance and results in immediate smooth sensitive control of the engine performance and in turn the automobile.
[0009] It is an additional object of the invention to provide the means for the necessary timing of the valve in a piston to be in sequence and in position relative to port opening and closing as well as acceleration and deceleration requirements of the valve.
[0010] It is also an object of the invention to present the means by which piston firing sequences and individual operations will be designed and controlled.
[0011] It is a further object of the present invention to provide a valve control system that is simplified in nature but more effective in controlling the percentage opening of valve ports and will completely eliminate the necessity of springs in the functioning of valves as found in present-day automotive internal combustion engines.
[0012] It is another object of the invention to provide a valve actuation system that will be considerably amenable to higher engine speed performance, enhancing the engine performance with resulting savings of gasoline.
[0013] It is a further object of the present invention to provide a simple robust construction of a valve actuator that is simple in operation and precisely controlled at all times.
SUMMARY OF THE INVENTION
[0014] These and other objects are well met by the presently disclosed effective, highly efficient, essentially springless (desmodromic) and substantially infinitely variable valve actuator system of this invention for use with, for example, an internal combustion engine. In one aspect of the invention a first action of a linearly reciprocating actuation system by a rotating cam and translating means interacts with a second controllable actuating means that controls valve position, and will be substantially infinitely variable in displacement thereby controlling the percentage of port opening in each piston separately or in unison. Any percentage opening of the valve port is achievable to the extent that the valve port can be closed indefinitely all the while the engine is performing under the influence of the remaining operating pistons. All the control exercised on the valves are performed easily, quickly and in total concert with the continuous smooth operation of the engine. All these functions can be computer controlled as a function of vehicle performance and will not affect the smoothness of operation of the internal combustion engine and in turn the vehicle itself.
[0015] In an embodiment of the invention, a reciprocating cam translating device is coupled to a rotary cam which receives an input from, for example, a pulley driven by a timing belt from an output shaft of an internal combustion engine. A second device, under controlled conditions, converts the reciprocating linear motion at the reciprocating cam translating device into a substantially infinitely variable reciprocating motion, which, in fact, is the valve itself. The rotary cam having a grooved track in a circular flat disk, with appropriate configuration, displaces a translating means which is a ball constrained in a slide which, in turn, reciprocates in a slot to achieve the first reciprocating linear movement. Attached to the slide is an assembly that contains a rotable link in which a slot of appropriate length and juxtaposition such that as the assemblage translates in accordance to the reciprocation of the first device along its line of action the slot presents an angle to that line. Pins affixed to the valve will ride in the slot and the valve, fixed in the engine block will move up and down as the slot reciprocates in accordance with the first cam/translating means. The up and down movement of the valve is dependent on the angle the slot makes with the line of action of the first translating means. A repeatable fixed point in the slot is required no matter what the angle is and as it will repeatably define the closed position of the valve regardless of how much opening of the port is required. If the link is rotated to where the centerline is co-axial with the line of action the valve has closed the port and will remain closed while the engine is still performing. Rotation of the link is performed by an adjustable member which has a slot parallel to the line of action that allows a pin, which rotates the link to any angle, to slide along the line of action and at the same time secures the angular position of the slot. This adjustable slide must move normal to the line of action in a housing affixed to the engine block. Control of the adjustable slide by an actuator, electromechanical or hydraulic, with position information of the slide will effectively control rotation of the link and in turn the amount of port opening.
[0016] The cam groove curvatures are shown such that the proper rise and fall along with dwell time are in concert with the engine. The rise and fall cam curvature can be of any variation—linear, spiral, sinusoidal or desired algebraic polynominal. Curvatures ideally should be such that significant effort should be exercised to use as long a time as possible to decelerate and land the valve as easily as possible to reduce landing click.
[0017] In another aspect of the invention computer control of each valve allows operation of any set of pistons such that for, preferably, an eight cylinder engine 2, 4, 6 or 8 pistons (although the invention is not limited to a specific number of cylinders) could be operating at any time while those that are operating have the further enhancement of variable valve displacement. Under the most economic conditions while stopped six cylinders could be non-functional while two cylinders with minimal valve openings would be sufficient to keep the motor running. Under computer control while accelerating, the required number of pistons and valve opening percentages will be functioning. At the required cruising speed the minimal number of pistons and most economical valve port opening will be in effect. There are any number of variations on how to control these valves. One controller could control all the valves at once with no ability to turn off any piston. Two controllers where one controls two pistons and the other controls four pistons. This gives the option of two, four or six pistons working. The ideal would be one controller for each cylinder.
[0018] For a better understanding of the present invention, together with other and further objects thereof, reference is made to the accompanying drawings and detailed description and its scope will be pointed out in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] [0019]FIG. 1A represents a partial, cross-sectional view of an embodiment of the valve system of this invention;
[0020] [0020]FIG. 1B represents a partial, cross-sectional view of an embodiment of a valve system of the prior art;
[0021] [0021]FIG. 2A represents a partial, cross-sectional view of a close valve position of the valve system of this invention;
[0022] [0022]FIG. 2B represents a partial, cross-sectional view of an open valve position of the valve system of this invention;
[0023] FIGS. 3 A- 3 F illustrate the kinematics of the valve system of this invention;
[0024] [0024]FIG. 4 represents a partial, cross-sectional view of the intake and exhaust valves of the valve system of this invention;
[0025] FIGS. 5 A- 5 F illustrate the variable displacement features of the valve system of this invention, with FIGS. 5 B- 5 D showing the invention with a portion removed;
[0026] FIGS. 6 A- 6 J illustrate various side and top views, respectively, moments in the movement of the valves within the system of this of this invention;
[0027] [0027]FIG. 7 represents a partial top view of two valve assemblies in a common housing of this invention;
[0028] FIGS. 8 A- 8 D illustrate the basic control function of the valve assemblies of this invention;
[0029] FIGS. 9 A- 9 D illustrate the methodology utilized with the valve assemblies of this invention; and
[0030] [0030]FIG. 10 is a schematic representation of a further embodiment of the invention representing multiple valves per cylinder.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0031] One embodiment of the present invention is shown in FIG. 1A. As illustrated, the elements of this variable, desmodromic, valve actuation system of this invention are configured in juxtaposition for intake and exhaust valves 1 and 2 , respectively, as they would interact with a single piston of a four-cycle internal combustion engine. By way of comparison the present prior art cam/spring valve actuation is shown in FIG. 1B. The benefits derived from a variable valve actuation capability are well known and chronicled in the automotive market. The object here is to present a substantially infinitely variable actuation system that can be precisely controlled to present the most advantageous configuration of valving including any percentage port opening on the intake cycle to closure of the intake port and resulting benign piston performance. The ability to perform these functions reliably and precisely while the engine is operational will be shown. This highly sensitive system, under computer control, and while the vehicle is traveling will effectively and efficiently consume gasoline and maximize engine performance. The description and kinematics of this substantially infinitely variable, desmodromic, valve actuation system of the present invention follows.
[0032] In FIG. 2A and 2B, a standard piston arrangement with the valve actuation system of the present invention is shown. As illustrated, the present invention eliminates the cam and spring method of valving with a essentially springless (desmodromic) kinematic system that positively controls the valve cycling and requires no springs. This is of considerable advantage, as the springs must be compressed to as much as 65 to 85 pounds depending on size and displacement of an engine. This large force is necessary to accelerate the valves at the high cyclic rates of an engine, as high as 6,000 to 7,0000 revolutions per minute (RPM). A considerable amount of energy is used just to deflect the springs rather than applying it to the engine crankshaft. The present invention will require considerably less, as the mass inertia of the valve system will be less and the kinematics of the valve actuation will be more effective. It will be possible with the present invention to run the engine at higher speeds which is a further enhancement to engine performance.
[0033] The basic principal in the operation of an internal combustion engine is the requirement of the proper timing of opening and closing the valves for the 4 cycles of each piston. Once the engine crankshaft starts to rotate, the relationship between it and the camshaft is established and the configuration of cams on the camshaft controls the timing of opening and closing the intake and exhaust valves. The standard automobile engine, using the cam/spring valve actuator system of FIG. 1B presents a repetitive, non-variable valve port opening which is inefficient for maximum engine performance and gasoline consumption. The basic kinematics of valve actuation in accordance with the present invention as shown in FIG. 1A will be described and will be further developed to introduce the variable aspect of valve actuation which is the preferred embodiment of the present invention.
[0034] [0034]FIGS. 2A and 2B illustrate closed and opened positions of a valve 33 in a cylinder 34 in accordance with the embodiments of the present invention. As the camshaft 10 rotates in a clockwise direction, in concert and at half speed of the crankshaft, the input cam 11 initiates a reciprocating motion via the cam assemblage 15 . FIGS. 3A and 3B illustrate in detail the kinematics of the cam assemblage 15 . In FIG. 3A input cam rise 25 is shown in the initial condition of the cam groove or track 20 and a ball 16 at the minimum Rc radius. As the input cam rotates in a clockwise direction, the ball 16 which is captured in a slide or drive link 17 is radially displaced to a maximum position D at Rmax by the rise cycle 26 which is shown in FIG. 3B. The slide is contained in the guideway 18 of the non-rotating backing plate 19 as shown in FIG. 3C. As the input cam continues to rotate the ball and slide are displaced inwardly along the guideway 18 by the full cycle 25 of the cam track 20 . This 90-degree rotation of the input cam will result in reciprocating the slide 17 back and forth in the guideway and establish a line of action (LOA) of the slide. As this input cam continues to rotate the remaining 270 degrees in FIG. 3E, the ball and slide will not be displaced as the cam track 26 will present a circular groove and thereby a constant radius Rc. This, in effect, results in a dwell period for the slide and no reciprocating motion will be in effect. The action described for 360 degrees rotation of the camshaft reflects the four cycles of either the intake or exhaust valve actions. The valve is opened and closed by the rise and fall cycle and for the 270 degrees for the intake valve compression, combustion and exhaust occur requiring the intake valve to remain closed for that period as the 270 degrees dwell will affect. For the exhaust valve, the action is offset 90 degrees as shown in FIG. 3F. Rise cycle 25 e , dotted, and fall cycle 26 e of the exhaust valve precede rise cycle 25 i and fall cycle 26 i of the intake cycle as the camshaft rotates in clockwise direction. As shown in FIG. 1A with intake valve 1 , (cam rotated 45 degrees) in opened position and exhaust valve 2 in closed position at radius Rc with its rise 25 e and fall 26 e cycle also rotated 45 degrees. These cams in their function and juxtaposition will be described later.
[0035] Alternate radial groove locations 14 shown in FIG. 3D are located in the backing plate 19 for the purpose of containing balls that will be used solely for stabilizing the plane of the rotating input cam. During rotation of the input cam these balls will merely reciprocate back and forth in these grooves 14 . Also shown in the backing plate is the guideway 18 that guides the slide during its reciprocating motion.
[0036] In FIG. 4 a basic configuration of the intake valve 1 and exhaust valve 2 are shown. As the camshaft 10 rotates in clockwise direction the cam assemblages 30 i and 30 e will slide along their respective lines of action and, in accordance with their rise and fall cycles, reciprocate back and forth and dwell in accordance with the slide. Slotted cam 31 at some angle α will reciprocate along the LOA in concert with the slide. In the slotted cam are pins 32 e and 32 i which extend from the valve stem are forced to travel in the slot and by virtue of the fact that the valve is captured in the cylinder head 3 and can only move up and down in the piston, the drive cam with its slotted angular cam track will force the pin down as the assemblage is displaced outwardly and, in turn, force the pin up as it returns to its initial position. Accordingly, as the camshaft rotates 90 degrees, the rise and fall cycles will displace the valve from a closed to an open to a closed condition. As the input cam continues to rotate the remaining 270 degrees, valve 2 will dwell and remain closed as shown in FIG. 4. In FIG. 4 the valve 1 is at its maximum 100% opened condition. This essentially springless kinematic action is a preferred embodiment of the present invention in that its minimal mass inertia and positive essentially springless control during actuation indicates an ability that can co-exist with higher engine speeds.
[0037] The configuration shown in FIG. 4 illustrates a valve actuation system with fixed displacement and is functional in the same capacity as the spring-cam system. Although the variable displacement feature of this invention has not yet been introduced the configuration represents substantial advantages over the spring-cam system in that considerable power savings are possible by eliminating the stored energy in the springs and the minimal mass inertia of the valve assembly will be accommodating to higher engine speeds.
[0038] [0038]FIG. 5A illustrates the variable displacement feature for valve actuation of the present invention. In the actuator system shown in FIG. 5A, the intake valve 50 illustrates the mechanism by which a valve stroke cannot only be incrementally adjustable to its full opening but can also be controlled to close the valveport indefinitely while the engine is running. The kinematics will be first described and the control features will follow. The exhaust valve 60 is not necessarily a controlled function and will not be included at this time, although a similar variable actuation system can be utilized therewith if desired.
[0039] The drive cam slot earlier described in FIG. 4 as a fixed angle is now included in the circular disk 52 in FIG. 5A and configured to be rotatable and preferably about point M, the center of the disk.
[0040] The rotation function as shown, although not limited to, comprises of a circular disk 52 of radius R that rotates in housing 53 containing a circular cavity also of radius R and a pin 54 , FIG. 5B, that extends beyond the housing 53 and rotates in circular slot segment 55 . Pin 54 is the means by which a control system, later described, can rotate the circular disk 52 any angular position within the angle α. FIGS. 5C, 5D and 5 E illustrate various rotational angles of the circular disk 52 and the resulting orientation of the slot 56 . In FIG. 5C, the plunge of the valve 51 will be maximum and equal to D. FIG. 5E shows the circular disk slot 56 rotated the angle λ so the slotted cam is horizontal and does not allow for any plunge of the valve 51 as the drive link slot is co-linear with the line of action of the reciprocating slide so there is no resultant downward displacement. FIG. 5D shows the circular disk slot rotated to an intermediate angle with the resulting downward motion B which is a fraction of the maximum excursion D. It can be seen that by rotating the circular disk link about M, adjustment of the valve 51 displacement is essentially infinitely variable from zero displacement to its maximum value D.
[0041] The center point M is critical in that it represents the closed position of the valve 51 and must be consistent and repeatable for any rotational angle of the circular drive disk as shown in 5 C, 5 D and 5 E. Since the valve 51 must be closed for each cycle and since the variable aspect of valve displacement can be required at any time it follows that for the valve to close for each cycle, the pin 54 must achieve the position at M for each cycle. By maintaining point M at the same juxtaposition regardless of circular disk rotational angle this requirement is well met.
[0042] In the assembly 70 of FIG. 5F, intake and exhaust valve actuator systems 50 and 60 , respectively, are shown as part of the preferred embodiment of the present invention. The intake variable valve actuation system 50 for the intake cycle was previously described in FIG. 5A and the exhaust valve actuation 60 was described in FIGS. 2A and 2B. The cam track or groove configurations which initiate the reciprocating motion of the slide are integral with the input cam 61 one on either face, groove or track 62 for the intake stroke and groove or track 63 for the exhaust stroke. As the input cam 61 rotates both assemblages, 50 intake and 60 exhaust will reciprocate at precisely the same rate in concert with the engine crankshaft 57 in accordance with cam grooves 62 intake and 63 exhaust.
[0043] FIGS. 6 A- 6 J illustrate side and top views of the input cam sequencing in concert with the four cycle internal combustion engine and timed by the engine crankshaft. Other cycle engines can also be based upon this inventive concept as well.
[0044] [0044]FIGS. 6A and 6B are snapshots of the moment when both the intake and exhaust valves 50 and 60 , respectively, are closed and their cam tracks 62 and 63 are at the Rc radius as described in FIG. 4. The camshaft clockwise rotation at this moment reflects the just completed closure of the exhaust valve and the imminent opening of the intake valve. The valve stems are at point M, the closed position of the valve ports 68 intake and 69 exhaust. FIGS. 6C and 6D occur after 45 degrees of camshaft rotation and illustrates the maximum displacement Rmax of cam track 62 and full displacement of the slide at point B resulting in the complete opening of the intake valve 68 and maximum port opening since the circular drive disk slot is oriented at its angle λ in accordance with FIG. 5C. This completes the intake cycle of the cylinder. In the meantime, the exhaust valve remains closed as its cam track 63 at point A still reflects the Rc radius and therefore maintains the valve in its closed position.
[0045] [0045]FIGS. 6E and 6F occurs 45 degrees later and at this instant Rc is reflected at points A and B which results in both cams 68 and 69 being closed. These valves will remain closed for the ensuing 180 degrees of camshaft rotation as both cam tracks 62 and 63 will present Rc at both points A and B. This is necessary to allow the piston to experience the compression and combustion cycles. Accordingly, the camshaft at the time has rotated a total of 270 degrees and the cam tracks have achieved their position shown in FIGS. 6G and 6H with exhaust cam track 62 ready to open the exhaust valve for the final 90 degrees at point A while the intake cam track 63 is at Rc at point A and remain at Rc for the final 90 degree rotation of the camshaft. FIGS. 6 I and 6 J reflect the opened exhaust valve 69 at 45 degree rotation of the camshaft from FIGS. 6 g and 6 H as dictated by cam track 63 at point A R max while the intake valve 68 remains closed as the intake cam track 62 is reflecting the Rc radius at point B. The exhaust port is constantly opened to its maximum port opening as shown, but can be adjusted by similar means as the intake valve if desired. An additional 45 degree rotation of the camshaft will close the exhaust port and complete the 4 stroke cycle of the engine. Its final configuration will be as shown in FIGS. 6A and 6B. It can be seen that the intake valve 68 opening can be adjusted by rotating the circular drive disk 52 in accordance with rotation of the camshaft just described. The valve displacement can be varied indiscriminately without affecting the piston cycling by having means of adjusting the circular drive disk cam slot can be achieved independently.
[0046] The precise sequencing and timing requirements for the four cycle engine are well met with the cam sequencing assembly 70 (shown in top view), FIG. 6B as the two cam grooves 62 and 63 are precisely machined and phased in a single input cam. It can be seen that the assemblage 70 is a complete, robust and simple assembly which can control one intake and one exhaust valve. FIG. 7 illustrates how two of these assemblies in a common housing 90 can control two intake and two exhaust valves of a single cylinder. Engine designs in the overwhelming number of vehicles operate with four valves for more efficient operation. To describe the control function of these valves, the basic principal will be presented kinematically and then introduced into the four-valve assembly of FIG. 7 to complete this embodiment of the present invention. FIGS. 8 A- 8 D illustrate the basic control function and is shown on a single intake valve.
[0047] The intake valve assembly 100 shows the valve as presented earlier, which includes the complete kinematic function in accordance with the preferred embodiments of this invention. It was shown how the valve actuation displacement can be incrementally varied by the circular disk ( 52 ) 101 drive slot 56 and slide assemblage 102 . As demonstrated earlier, (FIG. 5A, pin 54 ), adjustment pin 103 is the component used to rotate the circular disk for varying the drive slot 56 angle α which in turn varies the stroke of the valve 108 . As shown in FIG. 8A the angle α reflects maximum opening of valve 104 . There are two principal constraints imposed on the pin 103 . The first is the ability to rotate the pin for the desired valve opening and the second is to maintain the adjusted (closed) position while the valve is operational.
[0048] A control block 105 captures the pin 103 in slots 106 as it extends beyond the slide assembly 102 . Slots 106 must be aligned and maintained parallel to the line of action LOA of the slide assembly 100 . When a force P is applied to the control block 105 , the downward displacement D, FIG. 8C, which must maintain the parallel juxtaposition of the slots 106 parallel to the LOA, and then the pin 103 , which is captured in the circular slot segment 107 , will rotate circular drive disk 101 any angle incrementally from 0 degrees to the angle λ. As the circular drive disk 101 rotates the pin 103 rotates in circular slot segment 107 , it will require axial displacement in the slot 56 to accommodate the rotation. Constraint is required on the control block to assure the parallelism required of the slot 106 and the LOA. The kinematics are discussed here and a methodology will be presented later. When the desired angular position is achieved, the reciprocating motion of the slide assembly will also reciprocate the adjustment pin 103 at the same time. Slot 106 which is in the control block and parallel with the LOA will accommodate the action of adjustment pin 103 insuring its angular position relative to the angular position of the drive slot and in turn the desired displacement of the valve while the slide assembly is reciprocating. The control block is fixed relative to the valve assemblage 100 and insures the juxtaposition of circular drive disk from any loads applied to the valve and any dynamic noise impressed on the slide assemblage. FIG. 8B is a sectional view of the assemblage and shows the adjustment pin 103 in the slot 106 and the circular segment slot 107 of the slide housing 102 .
[0049] [0049]FIG. 8C illustrates an auxiliary view of the assembly in the condition of maximum valve displacement at slot angle while FIG. 8D illustrates the circular disk at 0 degree position after application of load P to rotate the circular drive disk. The centerline connecting the two views illustrates the fixed position of the slide assemblage but shows the change of the circular disk 101 , which is the difference between the flat 111 on the circular disk 101 and its radius R. The dotted position of the drive slot 110 which is the zero angle and no valve displacement is represented in FIG. 8D. It has been shown that the two conditions of restraint are well met by the control block 105 and demonstrates the required function of adjusting the intake valve displacement and maintaining the required displacement during the reciprocating motion of the slide assemblage and the proper sequencing cycle of the intake valve.
[0050] FIGS. 9 A- 9 D illustrate, but are not limited to, a methodology which can be used with all the preferred embodiments of the present invention. FIG. 9B is a top view of a four valve cylinder; 9 C is a cutaway top view and FIG. 9D is an auxiliary side view cutaway section. The four-valve assembly 120 as described in FIG. 7 is integrated with a control assembly 125 and integrated with intake valve assembly 135 as described in FIG. 5A. The control assembly 125 will demonstrate the control function described in FIG. 9A and as it will apply to a four valve cylinder of an internal combustion engine or any internal combustion engine regardless of the number of valves in its cylinders. The two intake valve slide assemblies 135 as shown in FIGS. 9B, 9C and 9 D will be controlled by the control block assembly 125 . As shown in 9 C and 9 D the adjustment pins 136 of both intake slide assemblies are captured in the control block slots 137 . The control block is captured in the guideway housing 127 . The block assembly is constrained in lateral and axial directions at 128 interface for axial motion and 129 interface for lateral motion. These interfaces are so disposed as to insure a vertical up and down motion of the control block that maintains the juxtaposition of the slot 137 parallel to the line of action of the reciprocating intake valve assembly 135 . The control block when acted upon by an actuator, such as, but not limited to, a hydraulic cylinder 140 , the centerline of which is so disposed as to be parallel with the valve, the control block can be incrementally displaced to produce the desired valve opening characteristic. Of course, it will be necessary to control the cylinder displacement and lock it in the desired position with suitable valving techniques. Accordingly, for a four-valve cylinder with two intake valves, yet another preferred embodiment of the present invention is the control aspects for varying the valve actuation.
[0051] It can be seen that, for example, in a six-cylinder engine with six such assemblies, that with a central control system that has position information of the hydraulic cylinders, it is possible to control gasoline intake for all cylinders individually or altogether and to control them as the engine is operating. Further, for 6 cylinder engines, six assemblies shown in FIG. 9A would be quite effective as only a single camshaft on each side of a V6 engine is required rather than the four camshafts, two intake and two exhaust, as required in the cam/spring valve actuation systems in present day automobile engines. Alignment between these shafts and timing is very critical and complicated as compared to the simple 6 assemblages of FIG. 9A and a single crankshaft. Timing in each piston is self contained, precise, repeatable and easily aligned. The valve actuation systems described above utilizes the same actuation assemblage for each cylinders with four valve and only requires adjusting each actuator in accordance with the firing sequence. The prior art spring-cam system presently in use not only requires the sensitive alignment and timing of the four camshafts but the installation of 24 springs all preloaded to produce 65 to 80 pounds of force. Finally, the elimination of power required to overcome these preloads and accelerate the valve mass inertia will be significant and contribute a more efficient delivery of power for each gallon of gasoline. The present invention without springs (desmodromic) and less mass inertia along with variable valve displacement, will offer a significant increase in performance for an internal combustion engine. The simple, robust actuation system of the present invention is not only more advantageous in performance but is more easily manufactured, assembled and installed over the cam-spring system presently installed in automobiles today.
[0052] As shown in FIGS. 1 - 9 , the valve configuration of an intake and exhaust valve mechanism is for a cylinder having two valves. There are engines with multiple valves per cylinder and include four and six valves per cylinder. As shown in FIG. 10, it is possible to include multiple valve actuation from the same drive link of the single valve mechanism. The drive 150 of this embodiment of the invention becomes a muti-fingered drive link with two drive links 151 and 152 with associated driving (actualting) mechanisms for each valve. Duplicate actuating mechanisms will be required for the four valves as shown. Accordingly, a single cam 153 on camshaft 154 controls four valves as shown, as for example, with the case of six valve cylinders.
[0053] Although the invention has been described with respect to various embodiments, it should be realized this invention is also capable of a wide variety of further and other embodiments within the spirit and scope of the appended claims. | A desmodromic valve actuation system for opening and closing at least one valve of an engine having a cam assemblage and a driving mechanism for reciprocal movement operably connected to said cam assemblage. The cam assemblage includes a cam mechanism for rotational movement and the driving mechanism also being operably connected to the at least one valve of the engine to move the at least one valve between a valve closed position and a valve open position and between the open position and the closed position in a manner directly related to the rotational movement of the cam mechanism. In addition, a mechanism is provided for adjustably controlling the movement of the at least one valve in order to provide a variable amount of opening of the at least one valve in the open position. The opening and closing of the at least one valve takes place without the intervention of a spring action. | big_patent |