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SPECIFICATION
This application bases its priority on Provisional Application No. 60/021,589, filed Jul. 11, 1996.
BACKGROUND OF THE INVENTION
Malignant transformation is characterized by uncoupling of proliferation and differentiation, leading to continuing amplification of cells with loss of their ability to progress to differentiation. Agents capable of restoring the differentiation ability of cancer cells are thus potentially useful in cancer therapy.
Various extracts, proteins and chemicals have been shown to induce differentiation of certain cancer cells in vitro and in vivo. For example, Sachs et al. (1987) Cancer Research 47: 1981 provide a review of induction of differentiation of leukemia myeloid hematopoietic cells, including observations that myeloid leukemia cells can be induced to differentiate in vitro and in vivo by a normal differentiating protein. Tallman et al. (1992) J. Clin. Pharmacol. 32: 868 review the role of retinoids in cancer treatment. Retinoids have been investigated as differentiating agents for the prevention and therapy of bladder and mammary cancers and leukemias. Platica et al. (1992) Endocrinolog 131: 2573 report that extracts of bovine pituitary and a rat mammosomatotropic tumor induce differentiation of rat mammary tumor cells.
Differentiation agents identified by in vitro studies and in vivo rodent studies have also been assessed clinically. For example, differentiation agents including hexamethylene bisacetamide and retinoic acid have entered clinical trials for cancer treatment and prevention and are reviewed by Linskey et al. (1995) Neurosurgery 36: 1. Successful use of differentiation agents for the treatment of acute promyelocytic leukemia has been reported by Warrell et al. (1993) New Engl. J. Med. 329: 177. Retinoids have been shown to be therapeutically useful in the treatment of cervical cancer by Lippman et al. (1993) J. Natl. Cancer Inst. 85: 499.
The clinical use of differentiation agents to induce cancer cells to differentiate and thus assume more normal characteristics has been termed differentiation therapy. Differentiation therapy provides an alternative approach to conventional cancer therapy such as cytotoxic chemotherapy. Accordingly, there is a need in the art for the identification and isolation or synthesis of new agents capable of promoting the differentiation of cancer cells.
SUMMARY OF THE INVENTION
The present invention is directed to pituitary differentiation factor (PDF), a pituitary factor that is capable of differentiating cells including breast cancer and prostate cancer cells.
In one embodiment, the present invention provides isolated nucleic acids encoding PDF. Vectors and host cells containing isolated nucleic acids encoding PDF are further provided.
Another embodiment of the present invention provides isolated and purified PDF and biologically active analogs and fragments thereof, and a method of making PDF and biologically active analogs and fragments thereof.
The present invention further provides a method of promoting differentiation of breast cancer or prostatic cancer cells comprising contacting the breast or prostatic cancer cells with a differentiation-promoting effective amount of PDF.
Another embodiment of the present invention provides a method of treatment of breast cancer or prostatic cancer comprising administering a therapeutically effective amount of PDF to a patient in need of such treatment.
In another embodiment of the present invention, pharmaceutical compositions are provided that include PDF or biologically active analogs or fragments thereof admixed with a pharmaceutically acceptable carrier.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts MCF-7 human breast cancer cells in conditioned medium in the absence of PDF.
FIG. 2 depicts MCF-7 human breast cancer cells treated with lysate of oocytes injected with cDNA encoding PDF, and illustrates aggregation induced by PDF.
FIG. 3 depicts DU145 prostate cancer cells cultured in the absence of PDF.
FIG. 4 illustrates the morphological changes, including aggregation and spheroid formation, induced by PDF on DU145 cells.
FIG. 5 provides the nucleotide sequence of SEQ ID NO:1.
FIG. 6 is a graph demonstrating the effect of oocyte lysate containing PDF on spheroid formation in MCF-7 cells.
FIG. 7 is a graph demonstrating the effect of PDF on spheroid formation in DU-145 cells.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is directed to pituitary differentiation factor (PDF). PDF is a polypeptide obtainable from mammalian pituitary and from pituitary tumors including MtTW10. PDF promotes the differentiation of cells including breast cancer and prostatic cancer cells.
In one embodiment the present invention provides an isolated nucleic acid encoding PDF. A plasmid designated pBS-PDF1 containing a 2.2 kB cDNA encoding PDF has been deposited on Jul. 8, 1996 with the American Type Culture Collection (ATCC), 12301 Parklawn Drive, Rockville, Md. 20852; in accordance with the Budapest Treaty and has been accorded accession number ATCC 97648. In a preferred embodiment, the isolated nucleic acid encoding PDF comprises the nucleotide sequence of SEQ ID NO: 1 set forth in FIG. 5.
In accordance with the present invention, an isolated nucleic acid encoding PDF may be obtained from mammalian pituitary by expression cloning. A mammalian pituitary cDNA library may be prepared by methods known to one of ordinary skill in the art, as described for example by Sambrook et al (1989) Molecular Cloning: A Laboratory Manual, 2nd edition, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y. In addition, mammalian pituitary cDNA libraries are available commercially, for example from Clontech, Palo Alto, Calif. A human pituitary library is preferred.
An isolated nucleic acid encoding PDF was obtained from a mammalian cDNA library by expressing the cDNA clones of the library, and assessing the expressed product for PDF activity in a functional assay. Various expression systems are known to the ordinarily skilled artisan. In a preferred embodiment, Xenopus oocytes are used as the host for expression of the pituitary cDNA. The use of Xenopus oocytes for the expression of exogenous nucleic acids is known in the art and described, for example, by Gurdon et al. (1983) Methods in Enzymology 101: 370. Expression vectors containing pituitary cDNA under the control of a strong promoter can be injected into the nuclei of oocytes, after which oocytes are incubated for from one to several days, followed by assessment of oocyte lysates or conditioned media (CM) for PDF activity. Alternately, mRNA can be synthesized in vitro from pituitary cDNA, and injected into oocytes, followed by assessment of oocyte lysates or CM for PDF activity as described hereinbelow. The pituitary cDNA may be divided into pools from which RNA is synthesized, injected into oocytes, and tested for functional activity. Positive pools are divided into subpools and the protocol is repeated until a single cDNA encoding PDF is identified.
Bioassays useful for the identification of PDF are based upon the ability of PDF to promote the differentiation of breast and prostate cancer cells. Any breast or prostate cancer cells that are responsive to the differentiation-inducing activity of PDF as described herein are suitable for use in the bioassay of the present invention. Various cultured breast and prostate cancer cells are available from the ATCC. In a preferred nonlimiting embodiment, the breast cancer cells used for the bioassay are the rat mammary tumor cell line MTW9/P1 available from D. Sirbascu, University of Texas Medical School, Houston, Tex. or MCF-7 human breast cancer cells available from the ATCC. In another preferred embodiment, the prostate cancer cells are from the human prostate cell line DU145 available from the ATCC.
Treatment of breast or prostate cancer cells with PDF causes undifferentiated cancer cells to differentiate. Differentiation can be measured by morphological and biochemical parameters that are consistent with differentiation toward the structure of a normal mammary or prostate gland. The cancer cells, which normally grow in culture as single cell suspensions, aggregate and form spheroids within 24 hours of treatment with PDF. Aggregation may be measured by removing and counting suspended single cells, then detaching and counting the remaining aggregated and adherent cells, and then determining the percentage of total cells that have aggregated. A statistically significant increase in aggregation of treated cells as compared to untreated cells is evidence of PDF activity. The measurement of aggregation thus provides a simple and convenient bioassay for PDF activity.
The aggregation bioassay may be performed as follows. About 1×10 5 breast cancer cells, for example MTW9/P1 cells, are grown in 1 ml serum-free Dulbecco's modified Eagle's Medium (DMEM) in the presence or absence of the expression product of the pituitary cDNA at a concentration of from about 10 ng/ml to about 10 μg/ml. The cultures are incubated at 37° C. in a 5% CO 2 atmosphere for about 72 hours. Suspended single cells are removed by rinsing with serum-free DMEM and then counted. The remaining aggregated and adherent cells are detached by trypsinization with trypsin-EDTA for five minutes and then counted. Cells are conveniently counted by viewing cells by light microscopy on gridded culture dishes. A dose-responsive increase in aggregation in response to treatment with the pituitary cDNA expression product indicates that the cDNA encodes PDF.
A spheroid formation assay may be performed as follows. About 1×10 5 prostate cancer cells, for example DU145 cells, are grown in RPMI 1640 medium (Sigma) supplemented with 10% fetal bovine serum (FBS) (BioWhittacker, Walkersville, Md.), 10 IU penicillin/ml and 50 mg streptomycin/ml at 37° C. in a 5% CO 2 atmosphere. Cultures are treated with various concentrations of PDF, for example from 50-300 ug/ml culture. After 72 hours, cultures are scored for the formation of spheroids. Spheroids are defined as multicellular aggregates with no individual distinguishable cell morphology. Cultures are conveniently scored by viewing gridded culture dishes by light microscopy and counting spheroids. A dose-responsive increase in spheroid formation is indicative of PDF bioactivity.
In a modification of the foregoing aggregation bioassay, aggregation and spheroid formation may be detected by light microscopy or electron microscopy of fixed sections. After culturing and treating cells as described above, cultured cells are fixed and sectioned for microscopy by methods known in the art. For example, cultured cells are fixed in 1.5% glutaraldehyde in 0.1 M cacodylate buffer for one hour. Pellets obtained by low speed centrifugation are postfixed in 1.5% osmium tetroxide in collidine buffer for 30 minutes, followed by 30 minutes in uranyl acetate in maleate buffer, and then dehydrated and embedded in Epon 812. For light microscopy, 1 μm sections are stained with methylene blue, azure-II, and basic fuchsin. For electron microscopy, 60 to 90 nm sections are cut and stained with uranyl acetate-lead citrate. Aggregation and spheroid formation can then be visualized by light or electron microscopy. A statistically significant increase in aggregation and spheroid formation of treated cells as compared to untreated cells is evidence of PDF bioactivity.
Treatment of breast cancer cells with PDF produces other effects that can be observed by microscopy, thus providing further PDF assays. By light microscopy, it can be observed that PDF-treated cells are smaller in size than untreated cells, and are clustered in organoid structures consistent with gland formation. By electron microscopy it can be observed that treated cells are smaller, with smaller nuclei than untreated cells. Further, the cytoplasm is rich in polarized organelles such as lysosomes and endoplasmic reticulum, as opposed to untreated cells that have vacuolated cytoplasm, with few organelles other than mitochondria.
Breast cancer cells treated with PDF also undergo biochemical changes that provide additional bioassays for PDF. Specifically, lactalbumin, which is secreted only in differentiated mammary cells, is produced by PDF-treated MTW9/P1 cells but not by untreated cells. Thus the synthesis of lactalbumin, as detected, for example, by conventional Northern or Western blotting, histochemical techniques, or immunoassays provides another bioassay for PDF.
By the foregoing cloning methods and bioassays, an isolated cDNA encoding PDF has been identified. It has thus been discovered in accordance with the present invention that a single nucleic acid encoding a single polypeptide directs the pituitary differentiating activity.
The isolated nucleic acid encoding PDF may be additionally characterized by its nucleotide sequence. Nucleotide sequencing may be accomplished by methods known to one of ordinary skill in the art, including for example the dideoxy chain termination method of Sanger et al. (1977) Proc. Natl. Acad. Sci. 74: 5463. An isolated nucleic acid encoding PDF in accordance with the present invention contains the sequence set forth at SEQ ID NO:1 in FIG. 5.
The present invention encompasses isolated nucleic acids that can be obtained from mammalian pituitary and pituitary tumors and that encode PDF, a polypeptide having the ability to promote the differentiation of breast cancer cells as determined by any of the above-described bioassays. In a preferred embodiment, the nucleic acid is the 2.2 kB nucleic acid contained in plasmid pBS-PDF1 and comprising the sequence set forth at SEQ. ID NO:1 in FIG. 5. In another preferred embodiment, the isolated nucleic acid is a contiguous fragment of the 2.2 kB insert wherein the fragment encodes biologically active PDF. The ordinarily skilled artisan can obtain fragments of the 2.2 kB insert by conventional molecular biological techniques, prepare expression vectors containing the fragments, express the nucleic acid, and assay the resulting product for PDF activity as described hereinabove to identify fragments that encode PDF.
Isolated nucleic acids encoding PDF can also be obtained by using synthetic nucleic acids having the sequence of SEQ ID NO:1 or fragments thereof as probes to isolate the desired nucleic acid from a pool of pituitary nucleic acids. Suitable methods are described, for example, by Sambrook et al.
In a preferred embodiment of the present invention, the isolated nucleic acid encoding PDF is contained in the 2.2 kB insert of plasmid pBS-PDF1. The present invention further encompasses analogs of the nucleic acid contained in the 2.2 kB insert of plasmid pBS-PDF1 wherein said analogs encode PDF. For example, the ordinarily skilled artisan, with the knowledge of the degeneracy of the genetic code, can determine nucleic acid sequences that encode the amino acid sequence encoded by the insert of plasmid pBS-PDF1. Further, the sequence can be selected to optimize expression in a particular host organism by utilizing known preferred codons for a host organism of choice. In addition, analogs may be made by making substitutions or deletions of residues that are not necessary for biological activity. Such analogs may be identified by the bioassays described above.
The present invention further encompasses nucleic acids isolatable from mammalian pituitary or pituitary tumors and capable of hybridizing under moderate or high stringency conditions to the 2.2 kB insert of plasmid pBS-PDF1 or to an isolated nucleic acid having the sequence of SEQ ID NO:1 or its complement and further capable of encoding biologically active PDF. Moderate and high stringency hybridization conditions are known to the skilled artisan and described, for example, in Sambrook et al. and Beltz et al. (1983) Methods Enzymol. 100: 226. High stringency conditions include, for example, hybridization at 68° C. in aqueous buffered solution or at 42° C. in 50% formamide. Moderate stringency conditions are typically achieved by reducing the temperature, reducing the amount of formamide, or increasing the ionic strength of the aqueous solution. The ability of the isolated nucleic acid of the present invention to encode biologically active PDF can be determined by the functional assays described hereinabove.
The present invention is further directed to vectors comprising the isolated nucleic acids of the present invention. The vectors are useful for the amplification and/or expression of the nucleic acids encoding PDF. In one embodiment, the vectors of the present invention comprise the nucleic acid encoding PDF operably linked to suitable transcriptional and/or translational regulatory elements to effect expression of PDF in a suitable host cell. The regulatory elements may be derived from mammalian, microbial, viral or insect genes, and include, for example, promoters, enhancers, transcription and translation initiation sequences, termination sequences, origins of replication, and sequences encoding leader and transport sequences. Suitable regulatory elements are selected for optimal expression in a desired host cell. Useful expression vectors can be constructed by methods known to one of ordinary skill in the art, and are also commercially available. Recombinant viral vectors, including retrovirus, parvovirus, densovirus and baculovirus vectors are particularly preferred.
In a preferred embodiment, the expression vector comprises a strong constitutive or inducible promoter operatively linked to a nucleic acid encoding PDF. Suitable promoters are well known and readily available to one of ordinary skill in the art and include, for example, bacterial, yeast, viral, mammalian, and insect promoters. Expression vectors compatible with insect and mammalian cells are particularly preferred.
Another embodiment of the present invention provides host cells comprising a nucleic acid encoding PDF. Host cells comprising the nucleic acid are useful for replicating and expressing the nucleic acid encoding PDF. The host cell may be procaryotic or eucaryotic, including bacterial, yeast, insect or mammalian cells. Insect and mammalian cells are preferred. Particularly preferred host cells are insect cell lines including, for example, Spodoptera frugiperda and Trichoplusia ni cells.
The isolated nucleic acids or expression vectors may be introduced into the host cells by methods known to one of ordinary skill in the art, including transformation, transfection and infection. For example, transfection may be accomplished by known methods such as liposome mediated transfection, calcium phosphate mediated transfection, naked DNA transfection, microinjection and electroporation. Transformation methods of procaryotic cells are described, for example, by Cohen et al. (1972) Proc. Natl. Acad. Sci. USA 69: 2110. Transformation of eucaryotic host cells is described, for example, by Sambrook et al.
Expression systems utilizing baculovirus vectors and insect host cells are also preferred. The use of baculoviruses as recombinant expression vectors to infect lepidopteran insect cells is known in the art and described for example by Luckow et al. (1988) BioTechnology 6: 47.
The present invention is further directed to isolated and purified PDF and biologically active analogs and fragments thereof. In a preferred embodiment of the present invention, the isolated and purified PDF has an amino acid sequence encoded by the DNA in plasmid pBS-PDF1.
Isolated and purified PDF may be made by introducing a nucleic acid encoding PDF into a suitable host cell, for example by transformation, transfection or injection, culturing the host cell under conditions suitable for expression, and recovering recombinant PDF. Recombinant PDF may be recovered from cells or culture medium by protein purification methods known in the art. In a preferred embodiment, an expression vector comprising a nucleic acid encoding PDF under the control of a suitable promoter is introduced into an insect or mammalian host cell.
Biologically active analogs and fragments of PDF are similarly made utilizing a nucleic acid encoding a biologically active analog or fragment of PDF. The isolated recombinant analog or fragment may be identified by the bioassay described above. The term "analogs" includes substitutions and alterations of the amino acid sequence of PDF, which substitutions and alterations maintain the biological activity of PDF. Amino acid insertional derivatives include amino and carboxy terminal fusions and single or multiple intra-sequence insertions. Deletional variants have one or more amino acids removed from the sequence. In substitutional amino acid variants, at least one residue has been removed or replaced by a different residue. Biologically active fragments are fragments of PDF or PDF analogs that do not encompass the entire length of the PDF polypeptide but which maintain the biological activity of PDF. The biologically active analogs and fragments may be made by recombinant methods as described for example by Sambrook et al, or by peptide synthetic techniques well known in the art such as solid phase peptide synthesis.
The present invention provides a method of promoting differentiation of breast cancer or prostatic cancer cells comprising contacting the breast or prostatic cancer cells with a differentiation-promoting effective amount of PDF or an analog or fragment thereof. A differentiation promoting effective amount of PDF is that amount that promotes differentiation of cancer cells by any of the above-described bioassays for differentiation.
Another embodiment of the present invention provides a method of treatment of breast cancer comprising administering a therapeutically effective amount of PDF or an analog or fragment thereof to a patient in need of such treatment. A therapeutically effective amount of PDF for breast cancer treatment is an amount that leads to change in the behavior of sentinel tumor masses such as morphologic or biochemical differentiation, reduction in tumor markers, tumor regression, apoptosis, or partial cessation of tumor growth or invasion. PDF is administered as a pharmaceutical composition containing PDF or a biologically active analog or fragment thereof and a pharmaceutically acceptable carrier.
Another embodiment of the present invention provides a method of treatment of prostate cancer comprising administering a therapeutically effective amount of PDF or an analog or fragment thereof to a patient in need of such treatment. A therapeutically effective amount of PDF for prostate cancer treatment is an amount that results in change in behavior of sentinel tumor masses as described hereinabove. PDF is administered as a pharmaceutical composition containing PDF or a biologically active analog or fragment thereof and a pharmaceutically acceptable carrier.
The formulation of pharmaceutical compositions is generally known in the art and reference can conveniently be made to Remington's Pharmaceutical Sciences, 17th ed., Mack Publishing Co., Easton, Pa. Formulation of PDF and biologically active analogs and fragments thereof for use in present invention must be stable under the conditions of manufacture and storage and must also be preserved against the contaminating action of microorganisms such as bacteria and fungi. Prevention against microorganism contamination can be achieved through the addition of various antibacterial and antifungal agents.
The pharmaceutical forms of PDF suitable for administration include sterile aqueous solutions or dispersions and sterile powders for the extemporaneous preparation of sterile injectable solutions or dispersions. In all cases, the form must be sterile and must be fluid to the extent that easy syringability exists. Typical carriers include a solvent or dispersion medium containing, for example, water buffered aqueous solutions (i.e., biocompatible buffers), ethanol, polyols such as glycerol, propylene glycol, polyethylene glycol, suitable mixtures thereof, surfactants, or vegetable oils.
Sterilization can be accomplished by an art-recognized technique, including but not limited to filtration or addition of antibacterial or antifingal agents, for example, paraben, chlorobutanol, phenol, sorbic acid or thimerosal. Further, isotonic agents such as sugars or sodium chloride may be incorporated in the subject compositions.
Production of sterile injectable solutions containing the subject PDF is accomplished by incorporating these compounds in the required amount in the appropriate solvent with various ingredients enumerated above, as required, followed by sterilization, preferably filter sterilization. To obtain a sterile powder, the above solutions are vacuum-dried or freeze-dried as necessary.
The subject PDF or analogs and fragments thereof are thus compounded for convenient and effective administration in pharmaceutically effective amounts with a suitable pharmaceutically acceptable carrier and/or diluent in a therapeutically effective dose.
As used herein, the term "pharmaceutically acceptable carrier and/or diluent" includes any and all solvents, dispersion media, antibacterial and antifingal agents, microcapsules, liposomes, cationic lipid carriers, isotonic and absorption delaying agents and the like which are not incompatible with the active ingredients. The use of such media and agents for pharmaceutical active substances is well known in the art. Supplementary active ingredients may also be incorporated into the compositions and used in the methods of present invention.
The precise therapeutically effective amount of PDF, analog or fragment thereof to be used in the methods of this invention applied to humans can be determined by the ordinary skilled artisan with consideration of individual differences in age, weight, extent of disease and condition of the patient. It can generally be stated that the PDF pharmaceutical preparation of the present invention should be preferably administered in an amount of at least about 1 mg per infusion dose, and more preferably in an amount up to about 10 mg per dose, or at a dose that achieves a local breast or prostate tissue concentration of from about 10 -9 M to 10 -6 M.
It is especially advantageous to formulate parenteral compositions in dosage unit form for ease of administration and uniformity of dosage. Dosage unit form as used herein refers to physically discrete units suited as unitary dosages for the mammalian subjects to be treated, each unit containing a predetermined quantity of active material calculated to produce the desired therapeutic effect in association with the required pharmaceutical carrier. The specification for the novel dosage unit forms of the invention are dictated by and directly depend on the unique characteristics of the active material (i.e., PDF, analogs, or fragments thereof), and the limitations inherent in the art of compounding such an active material for the treatment of breast or prostatic cell cancer.
The principal active ingredient is compounded for convenient and effective administration in effective amounts with a suitable pharmaceutically acceptable carrier in dosage unit form as hereinabove disclosed. In the case of compositions containing supplementary active ingredients, the dosages are determined by reference to the usual dose and manner of administration of the ingredients.
In the method of treatment according to the present invention, the PDF, analogs or fragments thereof may be administered in a manner compatible with the dosage formulation, in such amount as will be therapeutically effective, and in any way which is medically acceptable for the treatment of breast or prostatic cell cancer. Possible administration routes include injections by parenteral routes such as intravascular, intravenous, intraarterial, subcutaneous, intramuscular, intratumor, intraperitoneal, intraventricular or intraepidural. The compositions may also be directly applied to tissue surfaces, for example, during surgery. Sustained release administration is also specifically included in the invention, by such means as depot injections or erodible implants.
The invention is further illustrated by the following specific examples which are not intended in any way to limit the scope of the invention.
EXAMPLE 1
Pituitary Extracts Induce Differentiation Of Breast Cancer Cells and Prostatic Cancer Cells
Extracts prepared from bovine pituitary and from a mammosomatotropic pituitary tumor were assessed for ability to induce differentiation of breast cancer cells.
Alkaline pituitary extracts of the mammosomatotropic tumor MtTW10 and the pituitary tumor MTW9-0M obtained from Dr. Untae Kim, Roswell Park Memorial Institute, Buffalo, N.Y. were prepared as described by Platica et al. (1992) Endocrinology 1: 2573. Bovine pituitary extract was obtained commercially from Collaborative Research, Bedford, Mass.
Pituitary extracts were added to serum-free cultures of MTW9/P1 rat mammary tumor cells, MCF-7 human breast cancer cells, normal epithelial breast cells, and myelocytic and lymphocytic leukemic cells. After twenty-four hours, breast cancer cells, which normally grew as single cell suspensions, aggregated and formed spheroids. Electron microscopy demonstrated changes indicating differentiation toward the structure of a normal mammary gland including polarization of organelles, lumen-like formation, junction formation, and appearance of intracellular secretory granules. Northern and Western blots performed by standard methods demonstrated that pituitary extract induced expression of laminin, casein and lactalbumin, and overexpression of E-cadherin, in breast cancer cells. Normal epithelial cells and myelocytic and lymphocytic leukemic cells were unaffected by treatment with pituitary extract.
Prostatic cancer cells were obtained from the ATCC. Serum-free cultures of the prostatic cancer cells were treated with pituitary extract prepared by Platica et al. as described above and assessed morphologically and biochemically for evidence of differentiation. Pituitary extract induced differentiation of prostatic cancer cells as measured by bioassay.
Extracts were similarly prepared from rat liver and kidney and added to cell cultures as described above. Rat liver and kidney extracts had no effect on differentiation of breast cancer or prostatic cancer cells.
Various hormones and growth factors, including epidermal growth factor (EGF), transforming growth factor (TGF), platelet-derived growth factor (PDGF), fibroblast growth factor (FGF), insulin-like growth factor (IGF) -I and -II, estradiol, growth hormone and prolactin, were added to cultures of breast cancer cells and assessed for differentiation activity as described above. None of the hormones or growth factors exhibited the ability to induce differentiation.
EXAMPLE 2
Identification of a Cloning System for Pituitary Differentiating Activity
An expression cloning method was devised to further characterize the pituitary differentiation activity. To determine whether Xenopus oocytes were an appropriate expression system, Xenopus oocytes were assessed for absence of pituitary differentiation-like activity, toxicity for breast cancer cells in the selected functional assay, and presence of factors that may destroy or interfere with pituitary differentiation activity.
The aggregation bioassay for pituitary differentiation activity measured spheroid formation of MCF-7 breast cancer cells. MCF-7 cells aggregate and form spheroids in response to the pituitary differentiation-activity of pituitary extract. Spheroids were visualized by light microscopy.
Oocyte lysate was obtained by homogenization of oocytes in 0.15M NaCl, followed by centrifugation for 30 minutes at 15,000 xg at 4° C. and collection of supernatant. Various amounts of oocyte lysate containing 50-400 μg of protein and conditioned medium in which oocytes were kept for 24 hours, were added to 1 ml. cultures containing 1×10 5 MCF-7 cells, followed by incubation at 37° C. for 72 hours. No morphological changes or toxic effects on MCF-7 cells were observed at any concentration of lysate or medium, indicating that Xenopus oocytes do not contain a pituitary differentiation-like activity, and that oocyte lysate is not toxic to breast cancer cells.
To determine whether the pituitary differentiation activity remains active in the presence of Xenopus oocyte lysate, cultures containing 1×10 5 MCF-7 cells were incubated with 150 μg/ml pituitary extract at 37° C. for 72 hours in the presence or absence of varying amounts of oocyte lysate (50-400 μg/ml). The aggregation effect induced by pituitary extract was unaffected by the presence of oocyte lysate. These results indicated that the pituitary differentiation activity remains active in the presence of Xenopus oocyte lysate.
The ability of Xenopus oocytes to express the pituitary differentiating activity in amounts sufficient for detection by the aggregation bioassay was determined. Poly (A) + RNA from the rat pituitary tumor MtTW10 was prepared by the guanidinium/cesium chloride (CsCl) centrifugation method as described by Sambrook et al. in an RNAse free environment. Briefly, one gram of tissue was homogenized in 5 ml of 4M guanidinium thiocyanate, 0.1 Tris-HCl (pH 7.5) and 1% 2-ME, at room temperature. Then 9.7 ml homogenate was layered on a 3.3 ml pad of 5.7M CsCl and 4 mM EDTA Ph 7.5 and centrifuged at 30,000 rpm for 24 hours at room temperature. The RNA, pelleted at the bottom of the tube, was dissolved in 10 mM Tris pH 7.4, 1 mM EDTA, 0.1% SDS and then ethanol precipitated. The poly(A)+RNA was obtained by twice passing the total RNA on an oligo dT cellulose column. Seventeen micrograms of poly(A) + RNA were obtained from 900 μg total RNA. Then, 20 fully grown oocytes (stage V and VI), kept in sterile MBS solution at 19° C., were injected with 5 ml containing 50 ng mRNA per oocyte, using an automatic syringe. The oocytes were then placed in MBS solution containing penicillin and streptomycin and incubated at 19° C. After 3 days the supernatants from oocyte lysates (prepared as described above) and conditioned medium (CM) from RNA-injected oocytes were tested for pituitary differentiating activity. Cultures containing 1×10 5 MCF-7 cells in 1 ml serum free RPMI were incubated in the presence of various protein concentrations of oocyte lysate (10-300 μg) or CM (50-200 μl/culture), at 37° C. in a 5% CO 2 atmosphere. After 72 hours, aggregation was seen in MCF-7 cultures treated with the oocyte lysate, but not in CM-treated MCF-7 cells. A linear relationship between the number of aggregates obtained and the lysate protein concentration was seen, as shown in FIG. 6.
Similar experiments were performed using rat liver poly(A) + RNA. Neither the conditioned medium, nor the lysates from oocytes injected with liver mRNA had any effect on MCF-7 cells.
These results indicated that pituitary differentiation activity can be detected by the aggregation bioassay even when the whole population of pituitary MRNA was expressed in Xenolus oocytes.
The foregoing results demonstrate that Xenopus occytes do not contain a pituitary differentiating-like activity, are not toxic for MCF-7 cells, and do not destroy the pituitary differentiating activity. Further, Xenopus oocytes injected with pituitary MRNA expressed pituitary differentiating activity at a level detectable by the aggregation bioassay.
EXAMPLE 3
Characterization of Pituitary Differentiating Activity
A human pituitary cDNA library was obtained from Clontech, Palo Alto, Calif. and tested for the presence of cDNA encoding pituitary differentiating activity. The cDNA library was directionally cloned in the EcoRI-HindIII site of lambda Bluemid phage, which allows the transcription of either strand of DNA inserts with T7 or T3 RNA polymerases. Five μl of serial dilutions of phage library were mixed with 200 μl K802 E. coli (OD 600 =0.25) and incubated at 37° C. for 20 minutes. Then, 3 ml of 0.7% agar molten at 48° C. were added and the mixture was spread on top of a 100 mm plate containing 1.5% LB agar. After incubation at 37° C. overnight the plaques were counted for each phage dilution and the library titer determined to be 1×10 10 pfu/ml. Then a pool of 400,000 pfu from the library was plated on 20 plates (20,000 pfu per plate) and incubated at 37° C. until the plaques reached about 1 mm in diameter. The top agar was then harvested in SM buffer (0.1M NaCl, 10 mM MgSO 4 .7H 2 O, 10 mM Tris-HCl, pH 7.5, 2% gelatin) and the bacterial cells lysed with chloroform. The agar and bacterial debris were pelleted by centrifugation at 8,000 xg for 20 minutes. The supernatant was treated with 1 μg/ml DNase I and 5 μg/ml RNase A for 1 hour at 37° C. and then recentrifuged at 8,000 rpm for 20 minutes. The supernatant, containing the phage particles, was centrifuged at 25,000 rpm (Beckman, SW27 ROTOR) for 2 hours at 20° C. The pelleted phages were then resuspended in 0.5M Tris buffer pH 8, incubated with 100 μg/ml proteinase K for 30 minutes at 37° C., followed by three phenol, one phenol/chloroform and one chloroform extraction and ethanol precipitation.
Since in this library the T3 RNA polymerase synthesizes the (+) strand of cloned inserts, the phage DNA was linearized by digestion with Sal I which cuts in the polycloning region on the site of the insert opposite to T3 RNA polymerase promoter. For efficient translation, a CAP site was added to the 5' end of transcripts. The transcription followed Melton's protocol (Krieg et al., 1987, Methods Enzymol. 155 397) with minor modifications as described by Regec et al. (1995) Blood 85: 2711 using a mMessage mMachine kit from Ambion which can generate 30-50 μg of capped RNA 10 per each μg of plasmid DNA. The reaction was carried out in 20 μl volume using 5 μg linearized phage DNA and the protocol and reagents provided by manufacturer. After a one hour incubation at 37° C., 1U RNase free DNase I was added for each μg of DNA and the incubation continued for 15 minutes. Then the reaction mixture was phenol/chloroform extracted, followed by precipitation with half volume 7.5 MNH 4 acetate and three volumes of ethanol. With three such successive ethanol precipitations, 99% of unincorporated nucleotides were removed.
Twenty oocytes were injected with 50 ng RNA per oocyte, as described above, placed in MBS solution containing penicillin and streptomycin, and incubated at 19° C. for 3 days. The oocyte lysate, prepared as described above, was then tested for differentiating activity on MCF-7 cells using the above-described bioassay. The treated cells formed spheroids, similar to those formed by these human breast cancer cells in the presence of pituitary extract. A linear relationship between the number of spheroids formed and the protein lysate used in the bioassay was seen. (Please provide data). These data show that the Clontech human pituitary cDNA library contains one or more clones encoding for pituitary differentiating activity.
The above-described pool of 400,000 pfu from the pituitary cDNA library was used for sib selection. From the 400,000 pfu pool, ten subpools of about 40,000 plaques each were plated separately and grown until they reached about 1 mm in size. The phage DNA from each pool was prepared, and capped transcripts were synthesized with T3 RNA polymerase as described. RNA from each subpool was injected into 20 frog oocytes (50 ng/oocyte) and the lysates were tested for differentiating activity on MCF-7 cells. For each bioassay, controls with mRNA from pituitary tumors, with lysate from non-injected oocytes and with pituitary extracts were prepared. Of the ten subpools analyzed, three showed aggregating activity in the bioassay. Subpool #2 displayed the strongest biological activity and was selected for further sib selection. This subpool was divided in 10 subpools of about 4,000 pfu each, which were processed as above. From these subpools, the subpool #6 was shown to have the strongest differentiating activity, and was further divided in ten subpools (each containing above 400 pfu) which were processed similarly. Subpool #4 was found to contain the highest differentiating specific activity, and was used for further sib selection. This process was continued by further dividing positive pools and screening for differentiation activity until a single positive clone encoding pituitary differentiating factor (PDF) was identified. The identified PDF cDNA phage clone was converted into a plasmid clone following the procedure of clontech. The phage DNA was digested with NotI to release the pBLUESCRIPT plasmid DNA containing the cDNA insert. After phenol chloroform extraction and ethanol precipitation, the digested plasmid DNA was ligated and used to transform competent DM5 alpha E. coli (Gibco, BRL). The colonies were grown on agar plates with 50 μg/ml ampicillin, and contained the Bluescript plasmid with the cloned PDF cDNA.
To ensure that the plasmid clone contained cDNA encoding PDF, the transcript from the cDNA was synthesized with T3 RNA polymerase and translated in Xenopus oocytes. The oocyte lysate was tested for PDF activity as described above. FIG. 1 depicts MCF-7 cells incubated with control CM. FIG. 2 depicts MCF-7 cells treated with lysate of oocytes containing the cDNA transcript. The treated cells aggregated and formed spheroids, thus confirming that the cDNA clone encoded PDF. The plasmid DNA was then prepared for sequencing.
Five hundred ml ampicillin/LB media inoculated with 0.5 ml stock suspension of E. coli carrying the plasmid containing the PDF cDNA was incubated, with shaking, at 37° C. overnight. The next day the cells were pelleted at 8,000 xg for 20 minutes at 4° C. and plasmid DNA prepared by alkaline lysis method of Bimboim and Dolly (1979) Nucleic Acid Res, 7: 1573. The bacterial pellet was resuspended in 10 ml 50 mM glucose, 25 mM Tris-HCl (pH 8.0) and 10 mM EDTA (pH 8.0). After treatment with lysozyme, the bacterial cells were lysed with 0.2N NaOH, 1% SDS, for 10 minutes at room temperature. Then, 15 ml of 3M cold potassium acetate was added. The mixture was stored on ice for ten minutes and centrifuged at 4000 xg for 15 minutes at 4° C. The supernatant containing primarily plasmid DNA was filtered and precipitated with 0.6 volumes of isopropanol. The nucleic acid was sedimented by centrifugation at 5,000 rpm for 15 minutes, washed with 70% ethanol and dissolved in TE buffer.
CsCl/ethidium bromide gradients were prepared according to Sambrook et al. (1989) Molecular Cloning: A Laboratory Manual, 2nd edition, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y. One gram of CsCl was dissolved in each ml of plasmid preparation and 80 ul of ethidium bromide (10 mg/ml) were added to each ml of CsCl DNA solution. After the centrifugation at 60,000 rpm for 24 hours at 20° C. in a Ti 65 rotor, the bacterial DNA was separated in two bands: the upper band containing the linear, chromosomal and nicked circular plasmid DNA and the lower band consisting of closed circular supercoiled plasmid DNA. The plasmid DNA was recovered, ethidium bromide extracted with 1-butanol and after removing CsCl by dialysis, the DNA was precipitated with ethanol.
The PDF cDNA sequencing was performed in the Core Facility of Mount Sinai Medical School, New York, using the dideoxy chain termination method of Sanger et al. (1977) Proc. Natl. Acad. Sci. 74: 5463. Each portion of the clone was sequenced from both forward and reverse orientations. 530 nucleotides of the 2.2 kB insert were sequenced using M13-20 and reverse primers from Bluescript plasmid sequence. The 530 base pairs of the PDF cDNA have the nucleotide sequence set forth in SEQ ID NO: 1. The sequence was analyzed with the DNASIS program (Hitachi Software Engineering Co.) for homology with other sequences from GENBANK and EMBL. No simple homology of this sequence with any sequence from the GENBANK database was found. The greatest maximum matching found was 72.5% over a stretch of 98 base pairs, indicating that PDF is a novel polypeptide.
EXAMPLE 4
Effect of PDF on Prostatic Cancer Cells
The human prostatic cell line DU145 was obtained from the American Type Culture Collection and grown in RPMl 1640 medium supplemented with 10% fetal bovine serum (FBS) (BioWhittacker, Walkersville, MC.), 10 IU penicillin/ml 50 mg streptomycin/ml, at 37° C. in a humidified atmosphere containing 5% CO 2
To look for the effect of PDF on these cells, cultures containing 1×10 5 DU-145 cells in serum free-RPMI 1640 medium were treated with various concentrations of PDF (50-300 μg/ml culture). Three days later, the cultures were scored for the formation of spheroids. A correlation between PDF concentration and the number of spheroids formed was found, as depicted by the graph in FIG. 7.
FIG. 3 depicts DU145 cells cultured in the absence of PDF. FIG. 4 illustrates the morphological changes induced by 150 μg PDF/ml on DU145 prostate cancer cells after 72 hours. The PDF-treated cells aggregated and formed spheroids similar to those produced by breast cancer cells treated with PDF.
EXAMPLE 5
Sequencing and Expression of PDF
The complete nucleotide sequence of the PDF cDNA described in Example 3 is determined by a primer extension strategy as described, for example, by Sambrook et al. From the complete sequence, the start and stop codons, open reading frame and deduced amino acid sequence are determined.
Baculovirus expression vectors containing the cDNA encoding PDF are prepared. The PDF cDNA is cloned into the baculovirus vector AcNPv, and the recombinant baculovirus vector is used to transform cells of the insect cell line Sf21. The baculovirus/insect system is cultured to express recombinant PDF, which is then purified from the culture media or cell extracts. Biological activity of recombinant PDF is confirmed by the in vitro aggregation assay.
EXAMPLE 6
Effect of Recombinant PDF on Tumor Growth
Nude mice bearing the mammary tumor MTW9 are obtained by transplantation as described by Diamond et al. (1976) Cancer Research 36: 77. Recombinant PDF is administered to the tumor-bearing mice by intraperitoneal injection for 21 days at a dosage of 50 μg/kg per day. Reduction in tumor size in response to treatment with PDF is assessed at regular intervals by measuring tumor length, width and height with calipers and calculating tumor volume.
Various publications are cited herein, the contents of which are hereby incorporated by reference in their entireties.
__________________________________________________________________________SEQUENCE LISTING(1) GENERAL INFORMATION:(iii) NUMBER OF SEQUENCES: 1(2) INFORMATION FOR SEQ ID NO:1:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 538 nucleic acids(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE:(iii) ORIGINAL SOURCE:(A) ORGANISM: human(iv) FEATURE:(A) NAME/KEY:(B) LOCATION:(C) OTHER INFORMATION: Pituitary Differentiation Factor(v) SEQUENCE DESCRIPTION: SEQ ID NO:1:ACGCCAAGCTCTAATACGACTCACTATAGGGAAAGCTGGTACGCCTGCAGGTACCGGTCC60GGAATTCCCGGGTCGACGAATCCGCGGNCGCCCTATAGTGAGTCGTATTACGCGCCGATT120NAGGTGACACTATAGNCCGATTTAGGTGACACTATAGTCGATTTAGGTGACACTATAGTG180AGTCGTATTAGAAGCTTGGCGATTTAGGTGACACTATAGNCCGATTTAGGTGACACTATA240GTCGATTTAGGTGACACTATAGTCGGGCCGCCCTATAGTGAGTCGTATTAGGCGTCGATT300TAGGTGACACTATAGTCGTATTAGCCGCCCTATAGTGAGTCGTATTACGCGCCGATTTAG360GTGACACTATAGTCGTATTAGCCGCCCTATAGTGAGTCGTATTACGCGCCGATTTAGGTG420ACACTATAGNCGACGAATTCGCGGCCGCTCTAGAGGATCCAAGCTTACGTACGCGTGCAT480GCGACGTCATNNTCTTCTTTAGTGTCAACCTAAATCAATCANTGGCCGCCGGTTACAA538__________________________________________________________________________
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The present invention is directed to pituitary differentiation factor (PDF), a pituitary factor that is capable of differentiating cells including breast cancer and prostatic cancer cells. Isolated nucleic acids encoding PDF and related vectors and host cells are also provided. Restoration of differentiating ability to malignantly transformed cells provides a modality of cancer therapy. The isolated and purified PDF of the invention is accordingly useful in the treatment of breast and prostatic cancer.
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FIELD OF THE INVENTION
[0001] The present invention relates to a chromium plating method which utilizes trivalent chromium ions in the plating bath and insoluble anodes. An additive is proposed for the plating bath which will minimize the creation of hexavalent chromium ions at the anode while the plating bath is being used.
BACKGROUND OF THE INVENTION
[0002] Trivalent chromium based electrolytes have been in use industrially now for many years since the late 1970s. These processes have advantages over those based on hexavalent chromium in terms of health and safety and toxicity to the environment. However, selection of suitable anodes for these trivalent processes can present significant problems. Insoluble anodes have to be used since the cathode efficiency of the process is very low. The low cathode efficiency would cause a build up of chromium metal in the bath if soluble anodes made of chromium were used. Also, chromium is passive in the electrolyte until an anodic potential sufficient to dissolve the chromium as Cr(VI) is reached. This means that chromium would dissolve in a hexavalent rather than trivalent form if chromium metal anodes were used. Hexavalent chromium is a serious contaminant in trivalent processes and it is important to prevent the formation of this species. Historically, there have been several approaches to this problem: Chloride based electrolytes (where chlorine evolution from insoluble anodes may also be a problem) use bromide ions to catalyse anodic oxidation of chemical species such as formate ions or ammonium ions rather than oxidation of chromium(III) to chromium(VI) (for example see U.S. Pat. No. 3,954,574).
[0003] Due to the type of additives used in sulfate based trivalent processes, this strategy cannot be used. In sulfate based processes, there are two possible methods of preventing chromium oxidation. Originally, a divided cell arrangement was used with these processes (for example UK Patent No. 1,602,404). Typically, a lead anode was used in a sulfuric acid anolyte which was separated from the plating bath with a permeable membrane. The plating current was carried by hydrogen cations through a cation permeable membrane. This effectively prevented any contact of trivalent chromium with the surface of the anode, thus preventing oxidation of trivalent to hexavalent chromium. However, this type of arrangement was expensive and difficult to maintain. Also, the membrane had a limited lifespan resulting in unfavourable costs. A later development in trivalent chromium electroplating technology from sulfate based electrolytes utilised iridium/tantalum oxide coated anodes (for example see U.S. Pat. No. 5,560,815). These were used directly in the trivalent chromium solution and the surface of these anodes was found to have a low oxygen over potential (thus facilitating oxygen liberation at the lowest possible anode potentials). However, over a period of operation, the oxidation of trivalent to hexavalent chromium on these anodes was facilitated. Because of the problems outlined above, there remains a need for a suitable cost effective anode for sulfate based trivalent chromium plating processes.
SUMMARY OF THE INVENTION
[0004] The inventors herein propose a process for plating chromium metal onto a substrate, said process comprising contacting the substrate with a plating bath comprising:
[0005] (a) trivalent chromium ions;
[0006] (b) sulfate ions and/or sulfonate ions; and
[0007] (c) manganese ions;
[0000] wherein the substrate is made the cathode and insoluble anodes comprising a surface coating comprising iridium oxide, ruthenium oxide, and/or platinum are used.
[0008] The anodes used in this invention may be placed directly in the plating bath or may be separated from the plating bath in a compartment using a semi-permeable membrane as the separator. It is preferable, however, from cost and efficiency perspectives for the anodes to be placed directly in the plating bath.
BRIEF DESCRIPTION OF THE FIGURES
[0009] FIG. 1 —The effect of manganese on the hexavalent chromium in a trivalent chromium plating bath.
DETAILED DESCRIPTION OF THE INVENTION
[0010] The inventors herein have discovered that the addition of manganese ions to trivalent plating baths which use insoluble anodes can substantially improve the performance of the process and increase the lifetime of the anodes by a large margin. Non-limiting examples of the types of electrolytes useful in plating baths of this invention are given in U.S. Pat. Nos. 4,141,803; 4,374,007; 4,417,955; 4,448,649; 4,472,250; 4,507,175; 4,502,927; and 4,473,448. The amount of manganese ions added to the bath is preferably at least 10 ppm and can be up to the limit of solubility. However, in practice, we have found that large amounts of manganese (more than 700 ppm) co-deposit at the cathode to an unacceptable degree and cause problems with the cosmetic appearance and corrosion performance of the chromium deposited thereon. Therefore, the preferred amount of manganese ions added is within the range of 10 to 700 ppm and more preferably from 100 to 300 ppm. The manganese ions may be added as any suitable bath soluble salt. Manganese sulfate is the preferred salt because the sulfate anion is compatible with the composition of the plating bath.
[0011] Without wishing to be bound by theory, we consider that manganese (II) ions are oxidised to manganese dioxide at a lower potential than the oxidation potential of the chromium(III)/chromium(VI) reaction, thus forming a manganese dioxide coating on the surface of the insoluble anodes. The manganese dioxide coated anodes then operate by either facilitating oxygen evolution and/or inhibiting chromium oxidation. When the current is switched off, the manganese dioxide gradually re-forms manganese (II) ions and liberates oxygen. When the current is re-applied, the manganese dioxide coating re-forms on the anode. Thus the addition of a small amount of manganese ions to the plating bath prevents formation of excessive amounts of hexavalent chromium.
[0012] As a result, the inventors propose a process for plating chromium metal onto a substrate, said process comprising contacting the substrate with a plating bath comprising:
[0013] (a) trivalent chromium ions;
[0014] (b) sulfate and/or sulfonate ions;
[0015] (c) manganese ions;
[0000] wherein the substrate is made the cathode and insoluble anodes are used.
[0016] The source of trivalent chromium ions can be any soluble source of trivalent chromium ions. Preferably chrome (III) sulfate is used. However chromium III chloride, chromium (iii) oxylate, chromium (III) carbonate, chromium (III) hydroxide and other similar trivalent chromium ion salts or complexes can be used. The concentration of trivalent chromium ions in the plating bath is preferably from 5 to 40 g/l, most preferably from 10 to 15 g/l. Hexavalent chromium ions are detrimental to the proper working of the plating bath and as a result the concentration of hexavalent chromium ions in the plating bath is preferably as low as possible but most preferably less than 0.1 g/l.
[0017] Similarly the source of sulfate and/or sulfonate ions can be any soluble source of these anions. Preferably sulfuric acid is used. Other alternatives include alkane sulfonic acid, salts of sulfuric acid or salts of alkane sulfonic acids. The concentration of sulfate and/or sulfonate anions in the plating bath is preferably from 50 to 150 g/l, most preferably from 90 to 110 g/l. The pH of the plating bath is preferably maintained in the range of3 to 4.
[0018] The source of manganese ions can be any soluble manganese containing salt. It is preferable to use manganese sulfate. However, other salts such as manganese chloride, manganese sulfonate or manganese carbonate can also be used. Preferably the concentration of manganese ions in the plating bath is from 0,01 to 0.7 g/l, most preferably from 0.02 to 0.3 g/l.
[0019] As noted, the anodes used should be insoluble in the plating bath. In this regard, insoluble anodes are anodes which do not dissolve or are substantially insoluble in the matrix of the plating bath. Examples of suitable insoluble anodes include lead, lead alloy, platinized titanium anodes, or metal anodes comprising surface coating comprising iridium oxide, ruthenium oxide or mixed iridium/tantalum oxide. Preferably the anodes are metal anodes comprising a surface coating comprising iridium oxide, ruthenium oxide or mixed iridium/tantalum oxide. The metal substrate of the iridium oxide/ruthenium oxide or mixed iridium/tantalum oxide coated anodes can be any bath insoluble metal such as titanium, tantalum, niobium, zirconium, molybdenum or tungsten. Preferably titanium is used. These preferred anodes are well known and are described in U.S. Pat. No. 5,560,815, the teaching of which is incorporated herein by reference in their entirety.
[0020] Generally, the plating bath is operated at temperatures ranging from 55 to 65° C. The pH should preferably be from 3 to 4. The cathode current density should generally range from 2 to 10 Amps per square decimeter.
[0021] If platinized titanium or lead (alloy) anodes are used, the concentration of manganese ions in the plating bath may need to be increased into the higher end of the recommended range. In this case, manganese ion concentrations of from 0.6 to 0.7 g/l are recommended.
[0022] Other additives useful in the plating bath of the invention include carboxylic acid anions such as formate, oxalate, malate, acetate and boric acid.
Example I
[0023] In order to test the effectiveness of the invention, we used an iridium oxide coated tantalum anode which had been used to the end of its effective life and was producing substantial amounts of hexavalent chromium. This was introduced to a cell equipped with a cation exchange membrane. Both sides of the cell were filled with the trivalent chromium plating electrolyte. The purpose of the cell was to isolate the anode and cathode reactions so that any hexavalent chromium produced at the anode could not be reduced at the cathode. Thus we considered that this would represent a “worst case” scenario.
[0024] FIG. 1 shows the results we obtained using a trivalent chromium electrolyte containing:
[0000] 7 g/l Chromium metal added as basic chromium sulfate 160 g/l Sodium sulfate 75 g/l Boric acid 10 g/l Malic acid
The cell was operated at 60 degrees centigrade using an anode current density of 5 amps/square decimetre and a pH of 3.4. The volume of the anolyte was 3 50 ml.
[0025] It can be seen from this figure that in the comparative example (no manganese added), the hexavalent chromium increased very rapidly reaching a value of 245 ppm after an electrolysis time of 60 minutes. With 100 ppm of manganese sulfate added (equivalent to 30 ppm manganese), the amount of hexavalent chromium produced still continued to increase reaching a value of 130 ppm after 60 minutes. Even at this manganese concentration, the hexavalent chromium generation rate was markedly reduced when compared to the comparative example. The effect of higher concentrations of manganese sulfate (0.25 g/l and 0.5 g/l respectively) are also demonstrated. These examples illustrate that at 0.5 g/l manganese sulfate (equivalent to 150 ppm manganese), after 80 minutes continuous electrolysis, no further increase of hexavalent chromium was determined. This indicates that after this period, the anode was substantially inhibited from producing hexavalent chromium.
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A plating process for plating chromium metal onto substrates is disclosed. The process uses a trivalent chromium plating bath with a sulfate and/or sulfonate matrix. The process also utilizes insoluble anodes. An addition of manganese ions to the plating bath inhibits the formation of detrimental hexavalent chromium ions upon use of the plating bath.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a pulse detecting device for detecting pulses having any frequencies, and more particularly, to a device for generating a pulse signal based on the slower pulses of input pulse signals.
2. Description of the Background Art
In order to detect one or more pulses, conventional mechanical pulse detection devices employing switches have been used. In the conventional device, since there must be provided mechanical processing, the structure is complicated and it has been difficult to decrease the size of the device.
SUMMARY OF THE INVENTION
An essential object of the present invention is to provide a pulse detecting device which can be manufactured with electronic elements of a small size.
Another object of the present invention is to provide a pulse detecting device which can be assembled with semiconductor circuit elements.
According to the present invention, there is provided a pulse detecting device which comprises
a pulse detection circuit, or condition detecting circuit, having two input terminals for receiving separate pulse signals and for detecting the condition of the received signals,
a pulse change detecting circuit, or condition change detecting circuit, for detecting the change of the condition of the received signals in said condition detecting circuit, and
a pulse synthesizing circuit for synthesizing the pulse signals obtained in said condition change detecting circuit and for generating pulse a signal corresponding to any one of the input pulse signals having the slower pulse frequency.
There is further provided a pulse detecting device which comprises:
first means for receiving two input pulse signals and for generating pulse signals at two separate output terminals with different phase, even if the two input pulse signals change with the same phase,
second means for generating a pulse signal by detecting a condition of the outputs of the first means,
third means for discriminating change of the output of the first means, and
frequency dividing means for dividing the frequency of the output of the third means into 1/2 so that the frequency dividing means generates pulse signals corresponding to any one of the input pulse signals having the slower pulse frequency.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitative of the present invention, and wherein:
FIG. 1 is a block diagram showing an embodiment of a pulse detecting device according to the present invention,
FIG. 2 is a detailed circuit diagram of the pulse detecting device shown in FIG. 1,
FIG. 3 is a state diagram representing operation of the device shown in FIGS. 1 and 2,
FIG. 4 is a timing diagram showing an operation of the device in FIGS. 1 and 2,
FIG. 5 is a block diagram showing another embodiment of a pulse detecting device according to the present invention,
FIG. 6 is a detailed circuit diagram of the device shown in FIG. 5,
FIG. 7 is a timing diagram showing the operation of the device shown in FIG. 6,
FIG. 8 is a circuit diagram showing operation of the device shown in FIG. 5, and,
FIG. 9 is a timing diagram showing operation of the device shown in FIG. 5.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, two pulse sources 1 and 2 are connected to a condition detecting circuit 3, or a pulse detecting circuit, which detects two input pulses X and y, applied thereto through terminals 1X and 1Y from the input pulse sources 1 and 2, and generates four output signals A, B, C and D by detecting the conditions of the input pulses X and Y, as defined hereinafter. The four output terminals 3A, 3B, 3C, 3D of the condition detecting circuit 3 are connected to four input terminals of a condition change detecting circuit 4, or a pulse change detecting circuit, which detects the change of the conditions of the signals A, B, C and D and generates two output pulses E and F. The pulses E and F generated at the circuit 4 are synthesized in a pulse synthesizing circuit 5 into an output pulse signal Z having a frequency of the slower pulse of the two pulses X and Y.
In the arrangement shown in FIG. 1, the condition of the input signals applied to the terminal 1X and 1Y are discriminated by the condition detecting circuit 3 and converted into four signals A, B, C and D, which are applied to the condition change detecting circuit 4 and the condition change of the two input pulses X and Y is outputted as the two signals E and F from the condition change detecting circuit 4. The output signals E and F are synthesized in the pulse synthesizing circuit 5 into the output pulse signal Z having a frequency based on the frequency of the slower pulse of the input pulses X and Y.
The detail of the pulse detecting device is shown in FIG. 2. The condition detecting circuit 3 is formed by four AND gates 31, 32, 33 and 34 and two inverters 35 and 36 connected as shown in the drawings. The condition change detecting circuit 4 is formed by two R-S latch circuits 41 and 42. The pulse synthesizing circuit 5 is formed by an exclusive OR circuit 51. In case there is a possibility of occurrence of two simultaneous pulses at the input terminals 1X and 1Y, there may be added a phase difference generation circuit 6 at the input terminals 1X and 1Y.
Although the output signal Z at the output terminal 1Z may directly be used, there may be provided a frequency divider 7 made of a flip-flop circuit 71 at the output terminal 1Z so as to obtain the output signal having 1/2 frequency of the output pulse signal Z at the terminal Z*. The ratio of the frequency division may be selected as desired.
In the embodiment shown in FIG. 2, two flip-flops 61 and 62 and an inverter 63 are used as the phase difference generation circuit 6 to which clock pulses sufficiently faster than the two input pulses X and Y are applied to the clock input terminal CK. In this arrangement, it can be spaced a time interval longer than a half of the clock period for the period between change of one pulse X*, for example, to generation of another pulse Y*, whereby it is possible to avoid the simultaneous occurrence of the two pulses X* and Y*.
FIG. 3 shows a state diagram for the condition detecting circuit 3. In the device shown in FIGS. 1 and 2, it is assumed that the states A, B, C and D are defined in the table below.
X*=0, Y*=0 : A
X*=1, Y*=0 : B
X*=0, Y*=1 : C
X*=1, Y*=1 : D
The pulses X and Y applied to the terminals 1X and 1Y are converted to the pulse signals X* and Y* having a predetermined phase difference by the phase difference generation circuit 6. The condition of the pulse signals X* and Y* is discriminated into four states A, B, C and D. Among the various state changes of the pulse signals X* and Y* when the pulses are applied to the terminals X and Y, there are detected the following state changes of A - B - D, A - C - D, D - B - A, D - C - A, B - A - C, B - D - C, C - A - B and C - D - B. The result of the discrimination is output as the signals E or F. It is noted that since the signals X* and Y* are so modified that they do not occur simultaneously, the condition changes A - D, D - A, B - C and C - B do not occur.
The pulse signals E and F are synthesized by the circuit 5 and the synthesized signal is frequency divided by the divider 7 so that there can be obtained the signals Z*, the frequency of which is divided into 1/2 from the frequency of the signals Z. FIG. 4 shows an operation of the embodiment shown in FIG. 2.
According to the embodiment shown in FIG. 2, it is possible to output the signal Z* based on the input pulse of the slower frequency of both pulses X and Y.
In the pulse detecting device explained above, if the state changes in the order of A - B - D - C - D - B, the wave form of the output signal Z* must be analogous to the wave form of the input signal Y which contains low frequency components rather than the wave form of the signal X. However, the wave shape of the output signal of the device shown in FIG. 2 is not analogous to the signal Y.
The embodiment shown in FIG. 5 and FIG. 6 eliminates the problem mentioned above.
It is noted that like parts are designated by like reference numerals throughout the drawings and the detailed explanation of the like parts already explained in the foregoing is herein omitted.
There is provided a detecting pulse generating circuit 10 which generates a pulse when any one of the signals X0 and Y0 is changed. The output of the detecting pulse generating circuit 10 is coupled to the condition change detecting circuit 4 to provide an enabling pulse to the condition change detecting circuit 4.
The condition change detecting circuit 4, as shown in FIG. 6, comprises two stages of flip-flops 31 and 32, and 33 and 34 for the X input and the Y input, respectively, and detects change of both input pulse signals X0 and Y0, generating signal EXO. The frequency of the signal EXO is divided into 1/2 by the frequency divider 7 and the divided output signal Z is generated.
Referring further to FIG. 6 showing the detailed circuit of the second embodiment of the pulse detecting device the detecting pulse generating circuit 10 comprises an exclusive OR gate 22, an exclusive NOR gate 23 and a flip-flop circuit 21. The clock pulses CK1 for the flip-flop 21 has a pulse frequency of twice of the frequency the clock pulses CK2 applied to the phase difference generation circuit 6. Every time the condition of the signals on the input terminals X and Y change, the circuit 10 generates a pulse PC on the line 24 in synchronism with the clock pulse CK1 with a pulse length equal to the length of one cycle of the clock pulse CK1.
The condition change detecting circuit 4 comprises four flip-flops 31, 32, 33 and 34 each receiving the signals PC as the clock pulses, AND gates 311, 312, 321 and 322, OR gates 313 and 323, two exclusive OR gates 35 and 36 and an inverter 37.
In operation, when the flip-flops 11 and 12 maintain the outputs X0 and Y0 (this condition is referred to as the condition S3), in this case, the flip-flops 31 and 32 hold the outputs X1 and Y1 of the condition S2. The flip-flops 33 and 34, which receive the signals DX1 and DY1 prepared by switching any one of X1 or X0 and Y1 or Y0 by the signal EXO, hold signals X2 and Y2, that is the condition S1.
When the level of the signals X0 and X2 are different, the output Xou of the exclusive OR gate 35 is made "1". When the level of the signals Y0 and Y2 are different, the output You of the exclusive OR gate 36 is made "1". When both of the exclusive OR gates output logic "1", the signal DX1 is made X0 and DY1 is made Y0.
As a result, assuming that the conditions S1 and S3 correspond to A and B respectively or vice versa, and to B and C or vice versa, the signal EXO is generated, whereby the condition the same as S3 is set as the conditions S1 and S2. Namely, when the signal EXO is generated, all of the conditions before generation of the signal EXO are cleared off and a new operation can be started after the signal EXO is generated. In case the condition changes in the same manner as A - B - D - C - D - B as shown in FIG. 4, the EXO signal is generated by the change A - B - D, the conditions A and B are neglected. Therefore, the EXO signal is not generated at the condition C but is generated at the time of change of the conditions C - D - B as shown in FIG. 9. It can be understood from FIG. 9 that the wave form of the signal Z, which is 1/2 the frequency of divided EXO signal is equal to the signal Y.
From FIGS. 8 and 9 showing the operation of the circuit arrangement of FIG. 6, it can be seen that the output signal Z is synchronized with the slower signal Y in the left half portion of the drawing of FIG. 9. In the right half portion, the signal Z synchronizes with the slower signal X.
The invention 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 invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.
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In a pulse detecting device, there is provided a condition detecting circuit, or a pulse detecting circuit, which receives separate pulse signals and detects the condition of the receioved signals. A condition change detecting circuit, or pulse change detecting circuits, detects the change of the condition of the received signals, whereby a pulse synthesizing circuit synthesizes the pulse signals obtained in said condition change detecting circuit and generates a pulse signal corresponding to any one of the input pulse signals having the slower pulse frequency.
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BACKGROUND OF THE INVENTION
This invention relates to the manufacture of chenille yarns. More specifically, the invention is directed to a method of making multi-segmented chenille yarns on a crochet knitting machine. In multi-segmented chenille yarns, adjacent longitudinal segments of the yarns are formed from different constituent yarns or filaments and can have different physical properties. The invention specifically encompasses making multi-colored chenille yarns without any need for application of dye to the finished yarns by manufacturing chenille yarns with segments formed from constituent yarns or filaments of different colors.
In the prior art, chenille is made in a flat form, or a form having a generally rounded cross section, i.e., akin to a pipe cleaner. The latter, generally round form, is usually more desirable than the flat type of yarn.
Prior art flat chenille yarns are produced on machines specifically made to produce this type of yarn. These machines typically use a form of twisting or spinning yarns around a V-shaped former foot. As the yarns progress down the “V”, a circular knife is slid up the “V” for cutting the yarn fibers thereby forming a chenille yarn. Flat chenille yarns are also produced on leno type weaving machines in the form of a fabric which is then slit into flat chenille yarn. The aforementioned prior art methods of producing chenille yarn require specialized machinery which is expensive and consumes valuable space in a yarn-producing factory.
It is also known in the art to knit a fabric from which chenille yarns are obtained by slitting the knitted fabric as is disclosed in U.S. Pat. No. 2,845,783 to Underwood for Chenille Fur Strips and Method of Manufacture. U.S. Pat. No. 1,981,741 to Morton for Manufacture of Chenille also discusses manufacturing chenille by first producing a preparatory cloth and then cutting the cloth into strips which constitute the chenille. U.S. Pat. No. 3,715,878 to Kim for a Process for Making Chenille-Type Yarn discloses the formation of flat chenille yarns by slitting a fabric between warp threads.
Multicolored chenille yarns, that is yarns having longitudinal segments of different colors, are known for use in achieving decorative effects. In order to manufacture such multi-colored yarns, it has heretofore been necessary to dye segments of the yarns along their lengths or sections of fabric from which the chenille yarns are cut. Dyeing is a time consuming and expensive process which can significantly increase the cost of manufacture of multi-colored yarn vis-à-vis conventional monotone yarn. Moreover, because yarns are generally dyed in a wound disposition, spacing between color changes varies along the radius of the winding.
It is known in the art to employ colored filaments in the manufacture of yarns which can have a space-dyed appearance. For example, U.S. Pat. No. 5,613,285 to Chester, et al. for a Process For Making Multicolor Multifilament Non Commingled Yarn teaches how to assemble different colored filaments into a single yarn which can provide multicolor effects rather than a diffused or blended color effect, including a space-dyed appearance and a “chunky appearance.” U.S. Pat. Nos. 4,993,218 and 5,056,200 to Schwartz et al. for Textured Yarns And Fabrics Made Therefrom also describe a method for making yarns which can have a space-dyed appearance when multicolored supply yarns are employed. However, neither Chester et al. nor Schwartz et al. disclose how to produce multicolored chenille or chenille-like yarns, or how to produce such yarns on a conventional crochet knitting machine.
SUMMARY OF THE INVENTION
The instant invention overcomes the aforestated shortcomings of prior art methods of making chenille yarn and, in particular, multi-colored chenille yarn, by teaching a method which provides for knitting a fabric on a conventional crotchet knitting machine and applying parallel spaced chain stitches to the fabric in a warp direction transverse to the weft yarns from which the fabric is knitted and parallel to the direction of movement of the fabric through the machine. The introduction and withdrawal of different weft yarns each having unique physical properties, e.g., having differing colors, during the knitting process produces a knitted chenille fabric having a sections formed from different weft yarns which have the color and/or other physical characteristics of the weft yarns from which they are knitted.
Parallel cuts through the fabric are then made between the parallel chain stitches to form flat chenille yarns having alternating colors along their lengths. By interrupting and restarting the application of the weft yarns to the knitting process, gaps my be formed in the knitted fabric which, when longitudinally slit, result in the formation of chenille yarns having spaced slubs.
The flat chenille yarns may be passed through a twisting machine to form chenille yarns having substantially round cross sections. Differently colored weft yarns may be interchanged throughout the knitting cycle to produce multicolored flat or round chenille yarns without having to dye the chenille yarns.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a crotchet knitting machine suitable for use in accordance with the preferred embodiment of the invention.
FIG. 2 is a view of a fabric crotchet knitted in accordance with the method of the preferred embodiment of the invention.
FIG. 3 is a view of the crotchet knitted fabric shown in FIG. 2 as it is being slit into individual chenille yarns in accordance with the method of the preferred embodiment of the invention.
FIG. 4 is a view of a segment of one of the individual chenille yarns made in accordance with the method of the preferred embodiment of the invention.
FIG. 5 is a schematic view of a twisting machine for producing chenille yarns having a substantially round cross section in accordance with the preferred embodiment of the invention.
FIG. 6 is a view of a segment of one of the individual chenille yarns, made in accordance with the method of the preferred embodiment of the invention, having spaced slubs.
FIG. 7 is a view of an alternate form of a crotchet knitted fabric, made in accordance with the method of the preferred embodiment of the invention, as it is being slit into individual chenille yarns having spaced slubs.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1 of the drawings, there is shown a crochet knitting machine 1 with a needle bed having a horizontally reciprocable needle gauge 2 . Weft yarns 3 from a first creel (not shown) are fed through an inlay tube guide or carrier 5 , mounted on a laterally reciprocable weft bar 7 . Weft yarns 4 from a second creel (not shown) are fed through an inlay tube guide or carrier 6 , mounted on a laterally reciprocable weft bar 8 . The weft yarns 3 preferably differ from the weft yarns 4 in one or more physical properties such as weight, texture, and/or most notably, color. Although the physical property of the hereinafter referred to will be color, it is to be understood that as used in the disclosure and claims, the term “color” can include virtually any physical property of a yarn including, without limitation, texture, reflectance, size, and density.
Warp yarns 10 are fed from a beam 12 over a support bar 14 to eyelets 16 mounted on an eyelet bar 18 for guiding the warp yarns 10 .
A needle gauge 2 , with needles 9 mounted thereon, reciprocates inwardly and outwardly in a direction parallel to the Z axis as shown in FIG. 1 . Each time the needles 9 move outwardly, i.e., toward the eyelets 16 , each eyelet 16 wraps a segment of a warp yarns 10 threaded therethrough around the shank of a corresponding needle 9 . Each time the needles 9 move inwardly, i.e., away from the eyelets 16 , a hook on the end of each needle, be it a beard needle or a latch needle, pulls the segment of wrapped warp yarns 10 inwardly to form a loop. Contemporaneously, the previously formed loop is cast off from the needle over the beard or latch of the needle, depending upon whether the needle is of the beard or latch type.
During the portion of each cycle when the needles 9 are in their inward positions, a motor 28 is engaged via gears (not shown) with weft bar 7 causing it to move in the X direction as shown in FIG. 1, for transporting its respective guide carrier 5 across the width of the knitted fabric 15 and laying its corresponding weft yarn(s) 3 over the loops of warp yarns 10 held in the hooks of the retracted needles 9 . The needles 9 are then extended for having the next segments of warp yarns 10 wrapped onto their shanks. When the needles are again withdrawn into their inward (retracted) positions, the previous loops are cast off and the segments last wrapped onto the shanks are pulled through the cast off loops entrapping the last transversely laid weft yarns 3 within the chain stitches 11 formed by the interlocking loops of the warp yarns 10 .
The cycle is repeated with the needles 9 again being extended. The weft yarn carrier 5 is then moved across the width of the knitted fabric in a direction opposite to its direction of movement in the previous cycle to lay down another length of weft yarns 3 across the warp yarns 10 . The needles are again withdrawn to complete the chain stitches 11 and lock the last laid down length of weft yarns 3 into the knitted fabric 15 .
The foregoing cycle continues until it is desired to change a physical characteristic of the knitted fabric and, hence, the chenille yarns to be cut from it. For a space dyed effect, the weft yarns in the carrier 5 may be of a single color, e.g. red. The weft yarns in the carrier 6 may be of a different single color, e.g. blue.
In order to change the color of the fabric from red to blue, under control of a computer processor 29 , the motor is caused to disengage weft bar 7 and to engage weft bar 8 . The next time that the needles 9 are retracted, the weft bar 8 is moved in the X direction to transport carrier 6 containing blue weft yarns 4 which are laid down over the warp yarns 10 extending between the eyelets 16 and needles 9 . At this time, the weft bar 7 remains stationary with its carrier 5 outside the width of the knitted fabric 15 . The red yarns 3 , attached to the side of the web of knitted fabric 15 is drawn from its creel through carrier 5 and is suspended alongside the fabric 15 . At any time in the process, the weft bar 8 which transports the carrier 6 having the blue threads can be disengaged from the motor 28 under control of the microprocessor 29 and the weft bar 7 may be reengaged to again introduce red weft yarns into the knitted fabric 15 .
Both weft bars 7 and 8 may be engaged by the motor 28 under control of the microprocessor 29 to lay both red and blue weft yarns across the warp yarns 10 during each knitting cycle for still another visual effect. For simplicity, only two weft bars have been shown in FIG. 1 . Many additional weft bars, each with its own weft yarn carrier may be included for inserting a different weft yarn into the knitted fabric, either alone or in combination with one or more yarns distributed by the carriers on other weft bars.
Referring to FIG. 2, there is shown a section of a chenille fabric knitted on a crochet knitting machine having four weft bars each with a carrier for respectively feeding green, red, blue and white weft yarns into the fabric 15 . In FIG. 2, the weft yarns run horizontally across the page while the warp yarns 10 appear as vertical lines. Along the right side of the fabric are the threads which are suspended, when not being included in the knitted fabric, between successive exit and entry points from and into the fabric.
When the weft bar and carrier applying a green weft yarn to the fabric is disengaged, and the weft bar and carrier containing red yarns is engaged by the motor under control of the microprocessor 29 , the green weft yarns are suspended alongside the fabric as it advances through the knitting machine until the weft bar and carrier which feeds the green yarns is, again, engaged, at which time the green yarns enter the fabric. The same occurs for the red, blue and white weft yarns as seen in FIG. 2 . The suspended segments of the weft yarns can be trimmed and discarded or recycled.
Referring additionally to FIG. 3, the knitted fabric containing the weft yarns, all locked together by the chain stitches 11 formed from the warp yarns 10 , is fed about a take-up roller 13 (FIG. 1) and then passes over spaced circular rotating knives 17 for cutting the fabric between the warp yarns 10 having chain stitches 11 , thereby creating a group of individual strips of fibers, each locked in place by a central axial chain stitch 11 as can be readily seen in FIG. 4 . Each of the produced strips is a flat chenille yarn.
Referring now to FIG. 5, in order to produce chenille yarns which are substantially round in cross section, i.e., pipe cleaner-like, flat chenille yarns 21 are produced as described above. The flat chenille yarns are then passed through a high speed twister 23 creating a round chenille. The more twists per foot, the more round is the chenille yarn. Heat and/or steam can also be applied to the flat chenille for causing the yarn fibers to explode open.
The above-described process can be used with numerous types of yarn fibers including pre-dyed acrylic fibers such as supplied by Finetex Yarn Company which offers fibers in a complete color range and in a 2/24 acrylic.
Yield is conventionally measured in units of yarns per pound (ypp). The yield of the chenille yarn can be changed, e.g., by adding or removing the number of fibers or yarns fed into the laterally reciprocating weft carriers 5 , 7 , or by spacing the crocheting knitting needles 9 and their respective eyelets 16 closer, or further apart. The lower the yield, the greater is the diameter of the resulting round chenille yarn or the width of the flat chenille yarn. The greater the yield, the finer or thinner is the chenille yarn.
The above described process of the invention also permits the manufacture of chenille yarns having slubs spaced along their lengths. That is, chenille yarns can be fabricated with segments having weft yarns anchored by a central longitudinally running chain stitch 11 , interspersed with segments having no weft yarns, but only warp yarns 10 forming a narrow thread running between the weft yarn-containing segments as seen in FIG. 6 .
A fabric can be knitted with the microprocessor 29 programmed to have the weft bars and their carriers traverse the entire width of the knitted fabric, or, as shown in FIG. 7, to traverse bands of the fabric narrower than the entire fabric width. The result is a chenille fabric having parallel bands running in the warp direction, each of which has differing spaced segments which alternately include weft yarns and have no weft yarns.
In FIG. 7 there is shown a chenille fabric which can be formed using only a single weft bar and carrier. In the fabrication of the fabric of FIG. 7, the weft yarn carrier has been caused to reciprocate within the boundaries of one band of the fabric while an adjacent band receives no weft yarns. The carrier then reciprocates within the boundaries of the adjacent band for inserting weft yarns there while the other band now receives no weft yarns, thereby causing a checkerboard effect. A solid checkerboard effect can be obtained by applying two or more yarns of different colors to respective different bands, simultaneously, thereby creating a chenille yarn fabric having bands of different alternating color patterns each of which runs in the warp direction and each of which is displaced from an adjacent band in the weft direction.
Slitting of the chenille fabric shown in FIG. 7 on rotary cutters 17 results in the formation of chenille yarns having slubs with different spacings among adjacent yarns.
It is to be appreciated that the foregoing is a description of a preferred embodiment of the invention to which variations and modifications may be made without departing from the spirit and scope of the invention. Numerous effects may be obtained by varying the number and colors of weft yarns inserted into the chenille fabric, the boundaries of the bands of weft yarns that are laid down, the spacings between weft yarns, the distance between warp yarns as well as weft yarns, and the degree of twisting of the flat chenille yarns to form round chenille yarns.
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Chenille yarns having a spaced dyed appearance of made by crochet knitting a chenille fabric having a plurality of parallel spaced warp yarns with which chain stitches are formed for securing weft yarns laid transverse to the warp yarns as each stitch is formed. Weft yarns of different colors are applied at different times to create a chenille fabric with differently colored sections. Slitting of the fabric in the warp direction between the parallel chain stitches yields individual multi-colored chenille yarns which can be used a flat yarns or twisted to form round chenille yarns.
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This is a divisional of application Ser. No. 07/327,495, filed Mar. 24, 1989, now abandoned, which in turn is a division of application Ser. No. 07/243,753, filed Sept. 14, 1988, now U.S. Pat. No. 4,925,966.
FIELD OF THE INVENTION
The present invention relates to trifluorobenzene compounds represented by the general formula (I): ##STR2## wherein Z represents a cyano group or a carboxyl group and a process for producing said compounds. The trifluorobenzene compounds having the general formula (I) are novel compounds which have not been described in any of the previously published documents. These compounds are useful as starting materials for the manufacture of medicines, agrichemicals and other industrial chemicals. For instance, 2,4,5-trifluorobenzoic acid which is an intermediate for the synthesis of fluorine-containing 4-pyridone-3-carboxylic acid based bactericides can be produced by a sequence of steps starting with the compounds of the present invention.
BACKGROUND OF THE INVENTION
Several methods have been known for producing 2,4,5-trifluorobenzoic acid from 2,4,5-trifluorobromobenzene, such as synthesis by Grignard reactions as described, for example, in JP-A-58-188839 (The term "JP-A" as used herein means an "unexamined published Japanese patent application") and synthesis by reaction with cuprous cyanide as described, for example, in JP-A-60-72885, but these methods suffer disadvantages such as difficulty involved in obtaining 2,4,5-trifluorobromobenzene as a starting material.
Many reactions have also been known for dehalogenating aromatic halogen compounds with reducing agents and they include, for example, reduction with triethylsilane in the presence of palladium on carbon as described in J. Org. Chem., 34, G38 (1969), reduction with a zinc/acetic acid system as described in Organic Synthesis, Coll. Vol. 5, p. 149 (1973), reduction with a copper/benzoic acid system as described in J. Amer. Chem. Soc., 75, 3602 (1953), and reduction with a triethylsilane/cyclohexane system under ultraviolet irradiation as described in Synthesis, 1971, 537. However, the process of the present invention is not disclosed in any of the known documents including those listed above. The major problem with the prior art methods concerns the need to selectively reduce the 4-position only of tetrafluoroisophthalonitrile which contains four possible sites of dehalogenation (defluorination). It should also be mentioned that 2,4,5-trifluoroisophthalonitrile and 2,4,5-trifluoroisophthalic acid are novel compounds and processes for producing them are of course not yet to be known.
SUMMARY OF THE INVENTION
The main object, therefore, of the present invention is to provide a compound that is useful as a starting material for the synthesis of 2,4,5-trifluorobenzoic acid. In one aspect, the present invention intends to provide a process by which a novel compound 2,4,5-trifluoroisophthalonitrile can be produced selectively by reacting tetrafluoroisophthalonitrile with a metal hydride. In another aspect, the present invention aims at providing a process for producing a novel compound 2,4,5-trifluoroisophthalic acid with high yield by hydrolyzing 2,4,5-trifluoroisophthalonitrile under acidic conditions. In a further aspect, the present invention provides the compounds produced by these processes.
The present inventors conducted intensive studies on the reaction of tetrafluoroisophthalonitrile with metal hydrides. As a result, they found a process for producing 2,4,5-trifluoroisophthalonitrile which comprises reacting tetrafluoroisophthalonitrile with a metal hydride at -80° to 100° C. in an aprotic solvent. The 2,4,5-trifluoroisophthalonitrile produced by this process is a novel compound. The present inventors also conducted studies on the reaction of hydrolysis of 2,4,5-trifluoroisophthalonitrile, and found a process for producing 2,4,5-trifluoroisophthalic acid which comprises hydrolyzing 2,4,5-trifluoroisophthalonitrile under acidic conditions. The 2,4,5-trifluoroisophthalic acid produced by this process is also a novel compound.
DETAILED DESCRIPTION OF THE INVENTION
Tetrafluoroisophthalonitrile is used as the starting material in the process of the present invention for producing 2,4,5-trifluoroisophthalonitrile. This starting material can be prepared by known methods as described, for example, in British Patent No. 1,026,290 (1966); Bull. Chem. Soc. Japan, 40, 688 (1966); Kagaku Kogyo Zasshi, 73, 447 (1970); and JP-B-41-11368 (The term "JP-B" as used herein means an "examined Japanese patent publication"). For instance, the tetrafluoroisophthalonitrile can be obtained by a reaction of potassium fluoride and tetrachloroisophthalonitrile which is the effective ingredient of a commercially available agricultural fungicide, Daconi® (product of SDS Biotech K.K.).
The term "metal hydride" as used herein means both hydrogenated metal compounds and metal-hydrogen complex compounds. Useful metal hydrides include hydrides of boron, aluminum, silicon, tin, etc., lithium aluminium hydride, sodium borohydride and hydrogenated organoaluminum. Typical examples of hydrides of silicon include trimethylsilane, triethylsilane, diphenylsilane, phenylsilane, polymethyl hydroxysiloxane, etc. Typical examples of hydrides of tin include hydrogenated tri-n-butyltin, hydrogenated diphenyltin, hydrogenated di-n-butyltin, hydrogenated triethyltin, hydrogenated trimethyltin, etc. Typical examples of hydrides of aluminum include hydrogenated diisobutylaluminum, etc. Preferred examples of metal hydrides are sodium borohydride and hydrides of boron. The amount of metal hydrides used in the present invention varies with several factors including the type of metal hydrides, the reaction temperature, the reaction time and the like. Normally, metal hydrides are used in amounts of 1.1-3.0 equivalents in terms of hydrogen anion per mole of tetrafluoroisophthalonitrile, with the range of 1.3-2.5 equivalents being preferred. The higher the reaction temperature, the less of the metal hydride needs to be used.
The reaction temperature generally ranges from -80° C. to 100° C., preferably form -70° C. to 40° C. A more advantageous reaction temperature is within the range of from -70° C. to 20° C. Generally speaking, the selectivity of reaction tends to increase with decreasing temperature and more resinous by-products are prone to occur at elevated temperature.
Aprotic solvents are used as reaction solvents in the present invention. Typical examples of the aprotic solvents include ethyl ether, benzene, toluene, xylene, cyclohexane, tetrahydrofuran, dioxane, dimethyl sulfoxide, acetonitrile, hexamethylphosphoramide, etc. These aprotic solvents can be used either individually or in combination. When sodium borohydride is to be used as a metal hydride, tetrahydrofuran and acetonitrile are preferred as a solvent. The amount of the aprotic solvent used in the present invention varies with several factors including the type of solvent, the type and amount of metal hydrides, and the like. Preferably, the solvent is used in amounts of 0.5 to 5 l per mol of tetrafluoroisophthalonitrile. The larger the amount of solvent used, the reaction rate is more reduced. Conversely, the smaller the amount of solvent used, the generation of heat is more vigorously caused, thereby resulting in difficulty in controlling the reaction temperature.
The reaction time ranges from 0.1 to 20 hours, preferably from 0.3 to 10 hours. The higher the reaction temperature, the shorter the reaction time tends to be.
After the above reaction, a processing in which the excess or unreacted metal hydrides are decomposed may be performed. In the processing, in order to prevent the reaction system from becoming alkaline, a suitable acid such as acetic acid, formic acid, dilute sulfuric acid, dilute hydrochloric acid or aqueous ammonium chloride solution is added in a sufficient amount to maintain acidic or neutral conditions. The amount of the acid used is sufficient if it is more than the equivalents of the metal hydrides added to the reaction. The 2,4,5-trifluoroisophthalonitrile as a reaction product can be purified and isolated by extraction with an organic solvent such as hexane, cyclohexane, toluene or petroleum ether, optionally followed by fractional distillation.
The resulting 2,4,5-trifluoroisophthalonitrile may be hydrolyzed under acidic conditions to produce 2,4,5-trifluoroisophthalic acid. Mineral acids such as sulfuric acid, phosphoric acid, etc. or organic acids such as acetic acid, etc. are used to render the reaction conditions acidic and sulfuric acid is preferred. These acids can be used either individually or in combination, and are normally used in an amount of 3 parts by weight or more per one part by weight of 2,4,5-trifluoroisophthalonitrile, preferably 3 to 20 parts by weight. The acid concentration is in the range of from 5 to 80 wt %. At low acid concentrations, the reaction rate is slowed down, and at high acid concentrations, 2,4,5-trifluorophthalimide forms as a by-product. Therefore, the preferred range of acid concentration is from 50 to 70 wt %. The reaction temperature generally ranges from 100° C. to 200° C., preferably from 130° C. to 170° C. Hydrolysis under basic conditions is not suitable for the purpose of obtaining the desired 2,4,5-trifluoroisophthalic acid since the fluorine atom at 2- or 4-position will be hydrolyzed.
The present invention is now illustrated in greater detail by way of the following Examples, but it should be understood that the present invention is not deemed to be limited thereto.
EXAMPLE 1
Forty grams (0.2 moles) of tetrafluoroisophthalonitrile (hereinafter, referred to as TFIPN) was dissolved in 200 ml of tetrahydrofuran. To the solution being cooled at -10° C., a suspension of 3.20 g (0.084 moles) of sodium borohydride in 200 ml of tetrahydrofuran was added in small portions under agitation at -10° C. After the addition of the suspension, the resulting reaction solution was stirred at -5° to 0° C. for 3 hours and left to stand overnight at room temperature. After adding an aqueous solution of 14.3 g (0.24 moles) of acetic acid in 20 ml of water, tetrahydrofuran was distilled off under reduced pressure. The residual brown oil was continuously extracted with hot hexane, which was distilled off under reduced pressure. The residue was subjected to fractional distillation under reduced pressure, thereby obtaining 21,65 g of a fraction having a boiling point of 104° C./5 torr. The purity of the product was at least 99%.
1 H NMR (ppm, internal standard: tetramethylsilane, solvent: d--CHCl 3 ): 7.81 (ddd; J=8.54 Hz, 7.8 Hz, 5.86 Hz).
19 F NMR (ppm, internal standard: C 6 F 6 , solvent: C 6 F 6 ) 60.439 (ddd; 1F; J=14.65 Hz, 5.85 Hz, 0.49 Hz) 46.975 (ddd; 1F; J=20.50 Hz, 7.81 Hz, 0.48 Hz) 27.663 (ddd; 1F; J=20.50 Hz, 14.64 Hz, 8.54 Hz).
IR (cm -1 ; neat) 3060, 2240, 1625, 1500, 1450, 1360, 1275, 1205, 1120, 970, 905, 735, 715, 700.
The above spectroscopic data show that the product obtained was 2,4,5-trifluoroisophthalonitrile.
EXAMPLE 2
20.02 g of TFIPN was dissolved in 100 ml of acetonitrile. To the solution being cooled at -42° C., a solution of 1.52 g of sodium borohydride in 100 ml of acetonitrile was added dropwise for 2 hours with vigorously stirring. The resulting reaction solution yellowed. After the addition thereof, the reaction solution was stirred for 2 hours with its temperature held at -40° C. Thereafter, a solution of 10.4 g of acetic acid in 20 ml of acetonitrile was added dropwise thereto with its temperature held at -40° C. After removing the refrigerant, the stirring of the reaction solution was continued until its temperature became equal to room temperature. After distilling off acetonitrile under reduced pressure, the residue was dissolved in 100 ml of toluene and the solution was washed three times with 100 ml of a saturated solution of sodium chloride. The 15 washing water used was also extracted three times with 20 ml of toluene. After drying these resulting extracts with anhydrous magnesium sulfate, the solvent was distilled off under reduced pressure to obtain an oil in an amount of 21.10 g. The oil obtained was subjected to fractional distillation under reduced pressure, thereby obtaining 14.56 g of 2,4,5-trifluoroisophthalonitrile having a boiling point of 80°-90° C./0.55 torr (yield, 80%).
EXAMPLE 3
Forty grams (0.2 moles) of TFIPN was dissolved in 300 ml of tetrahydrofuran. To the solution being cooled at -55° C., a suspension of 4.75 g (0.125 moles) of sodium borohydride in 100 ml of tetrahydrofuran was added in small portions with stirring at -55° C. After the addition of the suspension, the reaction solution was stirred for 2 hours with its temperature held at -40° C. After a solution of 15.0 g (0.25 moles) of acetic acid in 20 ml of water was added, the stirring of the reaction solution was continued until its temperature became equal to room temperature. After distilling off tetrahydrofuran under reduced pressure, the residual oil was dissolved in 400 ml of ethyl ether and the solution was washed three times with a saturated solution of sodium chloride. After. drying with anhydrous magnesium sulfate, ethyl ether was distilled off. The residue was continuously extracted with hot cyclohexane, which was subsequently distilled off under reduced pressure to obtain an oil in an amount of 33.82 g. The oil obtained was subjected to fractional distillation under reduced pressure, thereby obtaining 25.19 g of a fraction having a boiling point of 96° C./4 torr. The purity of this product was at least 99.3%. The spectroscopic data of the product was the same as that obtained in Example 1.
EXAMPLES 4 to 8
Reactions were carried out in the same manner as in Example 1 except that the reaction conditions were changes as shown in the following Table 1. The results are also shown in Table 1 below.
TABLE 1______________________________________ Sodium ReactionEx- Boro- Tempera- Reactionample TFIPN hydride ture Time ProductsNo. (g) (g) (°C.) (hr) A B C D______________________________________4 2.00 0.10 30 4 48 0 27 285 2.00 0.23 30 6 34 18 0 486 2.00 0.15 65 1.5 45 1 2 527 40.0 2.95 -10 6 77 0 5 188 40.0 3.42 5 10 66 7 0 27______________________________________ Notes A: 2,4,5trifluoroisophthalonitrile, B: various forms of difluoroisophthalonitrile (mostly 2,5difluoroisophthalonitrile), C: unreacted TFIPN, and D: products other than A, B, and C (mostly resinous materials)
EXAMPLE 9
35.4 g of 2,4,5- trifluoroisophthalonitrile was added to 150 ml of 60% sulfuric acid and the mixture was heated under reflux for 5 hours. As the reaction proceeded, crystallization occurred. After the reaction, the reaction mixture was cooled to room temperature and the crystal was separated by filtration. The filtrate was extracted 5 times with 100 ml of ethyl ether each and the crystal was dissolved in the ethyl ether extracts. The resulting ethyl ether solution was washed several times with 10 ml of a saturated solution of sodium chloride. Thereafter, sulfuric acid was removed by washing with 10 ml of a 5% CaCl 2 solution saturated with sodium chloride. Following another washing with 10 ml of a saturated solution of sodium chloride, the solution was dried with MgSO 4 and ethyl ether was distilled off. The resulting white solid was dissolved in 240 ml of hot water and heated under reflux for 1 hour in the presence of activated carbon. Thereafter, the solution was filtered while hot and the filtrate was evaporated under reduced pressure. The residual white solid was further dried with a vacuum pump. The product was obtained in an amount of 41.96 g (yield, 97%). It was easily soluble in water, alcohol or ethyl acetate, but slightly soluble in benzene or hexane.
mp. 214°-216°.
1 H NMR (ppm, internal standard: tetramethylsilane, solvent: CD 3 OD): 7.94 (ddd; J=10.25 Hz, 8.91 Hz, 5.37 Hz). 19 F NMR (ppm, internal standard: C 6 F 6 , solvent: CD 3 OD): 51.440 (ddd; 1F; J=16.60 Hz, 6.34 Hz, 5.37 Hz) 35.442 (ddd; 1F; J=21.24 Hz, 8.91 Hz, 5.37 Hz) 22.454 (ddd; 1F; J=21.24 Hz, 16.60 Hz, 10.25 Hz).
IR (cm -1 ; Nujol mull): 3600˜2300 (br.), 1700 (br.), 1490, 1460, 1245, 1090, 950, 890, 800, 740.
These spectroscopic data show that the product obtained was 2,4,5-trifluoroisophthalic acid.
REFERENCE EXAMPLE
Synthesis of 2,4,5-trifluorobenzoic acid
A mixture of 2.20 g (0.01 mole) of 2,4,5-trifluoroisophthalic acid (dried under high vacuum), 1.0 ml of quinoline and 0.23 g of copper powder was heated on an oil bath at 200° C. After a while, the mixture liquefied and released a gas (ca. 280 ml by top purging). After the gas had been completely released, the liquefied mixture was cooled to room temperature, followed by addition of 15 ml of a mixture (1:1 by weight) of conc. HCl and water.
The mixture was subjected to repeated extraction with 100 ml of ethyl ether and the ethyl ether extracts were washed twice with 10 ml of 5% HCl solution that had been saturated with sodium chloride. Following drying on MgSO 4 , ethyl ether was distilled off to obtain a crude crystal in an amount of 1.66 g. The crude crystal was dissolved in 20 ml of hot water and subjected to discoloration with activated carbon for 1 hour. The solution was filtered while hot and allowed to stand overnight at room temperature to obtain the desired pure product (m.p.: 100°-101.5° C.) in an amount of 1.14 g (yield, 65%).
1 H NMR (ppm, internal standard: tetramethylsilane, solvent: CD 3 OD): 7.825 (td; 1H; J=10.49 Hz, 10.01 Hz, 6.34 Hz) 7.250 (ddd; 1H; J=10.50 Hz, 9.04 Hz, 6.59 Hz).
19 F NMR (ppm, internal standard: C 6 F 6 , solvent: CD 3 OD): 53.806 (dddd; 1F; J=16.12 Hz, 10.01 Hz, 8.78 Hz, 6.59 Hz) 36.406 (ddt; 1F; J=20.99Hz, 10.50 Hz, 9.04 Hz, 8.79 Hz) 20.660 (dddd; 1F; J=20.99 Hz, 16.11 Hz, 10.49 Hz, 6.34 Hz).
IR (cm -1 ; Nujol mull): 3200˜2400 (br.), 1690, 1510, 1460, 1395, 1340, 1295, 1265, 1220, 1200, 1155, 1070, 900, 860, 840, 760, 735cm -1 .
The above spectroscopic data show that the product obtained was 2,4,5-trifluorobenzoic acid.
The present invention provides a process by which 2,4,5-trifluoroisophthalonitrile can be produced from TFIPN with high yield and selectivity. Defluorination of TFIPN potentially involves the formation of various by-products, i.e., 4,5,6-trifluoroisophthalonitrile, 2,4,6-trifluoroisophthalonitrile, 2,4-difluoroisophthalonitrile, 2,5-difluoroisophthalonitrile, 4,5-difluoroisophthalonitrile, 4,6-difluoroisophthalonitrile, 2-fluoroisophthalonitrile, 4-fluoroisophthalonitrile, 5-fluoroisophthalonitrile. A change in the nitrile group is another possibility since the reaction is performed under reducing conditions. However, the process for production of 2,4,5-trifluoroisophthalonitrile in accordance with the present invention is immune to these problems and enables selective production of 2,4,5-trifluoroisophthalonitrile.
The so obtained 2,4,5-trifluoroisophthalonitrile may be hydrolyzed under acidic conditions and this enables 2,4,5-trifluoroisophthalic acid to be produced with high yield.
By reacting the so produced 2,4,5-trifluoroisophthalic acid with a suitable reagent such as copper/quinoline, 2,4,5-trifluorobenzoic acid which is a useful intermediate for the synthesis of chemicals can be easily obtained.
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.
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A trifluorobenzene compound represented by the general formula (I): ##STR1## wherein Z represents a cyano group or a carboxyl group, and a process for producing said compounds.
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CROSS-REFERENCE TO RELATED APPLICATIONS
The present application is a continuation in part of U.S. patent application Ser. No. 09/899,769 filed Jul. 2, 2001, now U.S. Pat. No. 6,633,139.
TECHNICAL FIELD
The present invention relates to converters for converting alternating current (AC) power main voltage to a voltage suitable for driving a lamp.
BACKGROUND OF THE INVENTION
Most electronic converters for converting AC power main voltage to a voltage for driving a lamp, such as a halogen lamp, are based on self-oscillating technology using bipolar transistors. Since bipolar transistors are current operating devices, obtaining feedback for oscillation is relatively simple. However, bipolar transistor converters with or without diode rectification suffer from several disadvantages. For example they are subject to secondary breakdown phenomena, increased current leakage and increased power losses at elevated temperatures. The practical limit for junction temperature is 100° C. (case temperature typically 85° C.). Bipolar transistor converters are also expensive for high voltage applications (for example 277V, 240V and 220V). They also are less efficient in operation than field-effect transistors, because a typical limitation on frequency of operation is 35 kHz due to switching losses. Precise protection against fault conditions is difficult in a simple circuit using bipolar transistors. In addition, size reduction is limited due to operating frequency limitations, and it is difficult to achieve UL Class B temperature classification (130° C. maximum insulation limitation) without a sacrifice in reliability.
U.S. Pat. No. 6,157,551 to Barak, et al., assigned to Lightech Electronic Industries Ltd., which issued Dec. 5, 2000, teaches a power converter using bipolar transistors. However, this converter suffers from the foregoing disadvantages.
U.S. Pat. No. 6,208,806 to Nerone, assigned to General Electric, which issued Mar. 21, 2001, teaches a power converter using N-channel and P-channel field effect transistors (FETs). Nerone achieves size reduction and improves efficiency by operating at higher frequencies (30 kHz-90 kHz). However, Nerone fails to address the issue of high temperature operation and fault protection. Besides, P-channel FETs are expensive and difficult to obtain compared to N-channel FETs.
There therefore exists a need for a converter that is simple and inexpensive to construct, while providing fault protection and achieving reliable, sustained operation at elevated operating temperatures.
SUMMARY OF THE INVENTION
The present invention provides a converter for converting alternating current (AC) power main voltage to a voltage suitable for driving a lamp. The converter comprises a rectifier circuit connectable to the AC power main, adapted to rectify the AC power main voltage and adapted to provide a direct current (DC) voltage; a driver circuit adapted to receive the unsmoothed DC voltage from the rectifier circuit, and provide a driver output voltage and a driver output current, and further adapted to receive an output current limiting signal; a starter circuit for providing a starter signal that initiates oscillation at an operating frequency in the driver circuit; a sensing circuit for sensing the driver output current and providing the output current limiting signal in response to the sensed driver output current; and a transformer for transforming the driver output voltage to a voltage suitable for driving a lamp such as a halogen lamp.
The sensing circuit may be further adapted to provide overheating protection for the converter. Overheating protection can be provisioned in a plurality of ways. In one embodiment, the sensing circuit includes a Negative Temperature Coefficient (NTC) thermistor that is in good thermal contact with the converter. A resistance of the NTC thermistor is reduced as a temperature of the converter rises. This causes the output current limiting signal to reduce output current from the driver circuit when the converter overheats. The reduction in driver output current permits the converter to cool and inhibits component failure. In another embodiment, a silicon diode is used rather than a NTC thermistor. A switching threshold of the silicon diode is reduced as a temperature of the converter rises. This causes the output current limiting signal to output current from the driver circuit to halt the rise in temperature.
In accordance with another aspect of the invention, a method is provided for controlling an output voltage of a driver circuit in response to an output current of a converter for converting an AC (alternating current) power main voltage to a voltage suitable for driving a lamp. The method comprises the steps of sensing the converter output current; testing whether the sensed converter output current exceeds a threshold; sensing the extent to which the converter output current exceeds the threshold; triggering a latch when the sensed converter output current exceeds the threshold and stopping an oscillation of the driver circuit; re-setting the latch after a period of time related to an extent to which the converter output current exceeds the threshold, and re-starting the oscillation of the driver circuit.
Advantages of the invention include power savings, extended service life for converter components, reduced power loss, and reduced heat generation.
A further advantage of the invention is an avoidance of high cost tantalum capacitors, and improved reliability at high temperature operation.
Another advantage of the invention is a precise control of output current in addition to protection against fault conditions, such as output short circuits.
A further advantage of the invention is an extended operational temperature range for the converter, which enables the converter to achieve an Underwriters Laboratories (UL) Class B temperature classification up to 130° C., which is a maximum insulation limitation.
Yet another advantage of the invention is providing a converter with an operating frequency that is greater than 30 kHz, which enables smaller converter packages and more power efficient converters especially when output rectification is MOSFET synchronous.
Still another advantage of the invention relates to decreased current leakage and switching losses at elevated temperature resulting from the use of MOSFET (metal oxide silicon field-effect) transistors for switching drive current and rectifying output current.
The invention also provides a converter that is reliable, versatile, compact and efficient, with a reduced parts count.
BRIEF DESCRIPTION OF THE DRAWINGS
Further features and advantages of the present invention will become apparent from the following detailed description, taken in combination with the appended drawings, in which:
FIG. 1A is a block diagram of a converter in accordance with the present invention;
FIG. 1B is another block diagram of a converter in accordance with the present invention;
FIG. 2 is a schematic diagram of an exemplary rectifier circuit for use in the converter shown in FIGS. 1A and 1B ;
FIG. 3A is a schematic diagram of an exemplary starter circuit for use in the converter shown in FIG. 1A ;
FIG. 3B is a schematic diagram of an exemplary starter circuit for use in the converter shown in FIG. 1B ;
FIG. 4A is a schematic diagram of an exemplary driver circuit for use in the converter shown in FIG. 1A ;
FIG. 4B is a schematic diagram of an exemplary driver circuit for use in the converter shown in FIG. 1A ;
FIG. 4C is a schematic diagram of an exemplary driver circuit for use in the converter shown in FIG. 1B ;
FIG. 5A is a schematic diagram of an exemplary sensing circuit for use in the converter shown in FIG. 1A ;
FIG. 5B is a schematic diagram of an exemplary sensing circuit for use in the converter shown in FIG. 1A ;
FIG. 5C is a schematic diagram of an exemplary sensing circuit for use in the converter shown in FIG. 1A ;
FIG. 5D is a schematic diagram of an exemplary sensing circuit for use in the converter shown in FIG. 1A ;
FIG. 5E is a schematic diagram of an exemplary sensing circuit for use in'the converter shown in FIG. 1A ;
FIG. 5F is a schematic diagram of an exemplary sensing circuit for use in the converter shown in FIG. 1B ;
FIG. 6A is a schematic diagram of an exemplary transformer circuit for use in the converter shown in FIGS. 1A and 1B ;
FIG. 6B is a schematic diagram of another exemplary transformer circuit for use in the converter shown in FIGS. 1A and 1B ;
FIG. 7 is a plot of an output voltage of the rectifier circuit shown in FIG. 2 , versus time;
FIG. 8 is a plot of an output voltage of the driver circuits shown in FIGS. 4A , 4 B, and 4 C, versus time;
FIG. 9 is a plot of an output current of the transformer circuit shown in FIG. 6A , versus time;
FIG. 10 is a plot of an output voltage of the transformer circuit shown in FIG. 6A , versus time; and
FIG. 11 is a flowchart of a method of controlling pulse-width modulation in a converter in accordance with the present invention.
It will be noted that throughout the appended drawings, like features are identified by like reference numerals.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1A illustrates a converter 100 A in accordance with the invention. The converter 100 includes a rectifier circuit 104 , a starter circuit 106 A, a driver circuit 108 A, a sensing circuit 110 A, and a transformer circuit 112 A. The rectifier circuit 104 has a first and second input 118 , 120 connectable to an AC (alternating current) power main 102 (shown in dotted outline), a first terminal 122 connected to a power supply node 117 and a second terminal 124 connected to a ground reference node 116 . The starter circuit 106 A has a first terminal 126 connected to power supply node 117 , a second terminal 132 connected to ground reference node 116 , a clamp output 128 , and a starter output 130 . The driver circuit 108 A has a first output 134 connected to the clamp output 128 of starter circuit 106 A, a first input 136 connected to the starter output 130 of starter circuit 106 A, a second input 138 , a first terminal 140 connected to the power supply node 117 , a second output 142 and a second terminal 144 . The sensing circuit 110 A has an output 146 connected to the second input 138 of the driver circuit 108 A, a first terminal 148 connected to the second terminal 144 of the driver circuit 108 A and a second terminal 150 connected to ground reference node 116 . The transformer circuit 112 A has an input 152 connected to the second output 142 of the driver circuit 108 A, a first terminal 154 connected to the power supply node 117 , a second terminal 160 connected to ground reference node 116 and a first and second output 156 , 158 connectable to a lamp 114 (shown in dotted outline).
FIG. 1B illustrates an alternative embodiment of a converter 100 B in accordance with the invention. The converter 100 B shown in FIG. 1B is identical to the converter 100 A shown in FIG. 1A except that a starter circuit 106 B has a charging output 129 connected to a thermal shutdown terminal 147 of a sensing circuit 10 F.
FIG. 2 illustrates a conventional embodiment of the rectifier circuit 104 . The rectifier circuit 104 includes a fuse 202 , an inductor 204 , a resistor 206 , a capacitor 208 , a metal oxide varistor (MOV) 210 , a first diode 212 , a second diode 214 , a third diode 216 and a fourth diode 218 . The fuse 202 is connected between the first input 118 of the rectifier circuit 104 and a first node 220 . Inductor 204 is connected between the first node 220 and a second node 222 . The resistor 206 is connected between the second node 222 and a third node 224 . The capacitor is 208 is connected between the third node 224 and the second input 120 of the rectifier circuit 104 . The MOV 210 is connected between the second node 222 and the second input 120 of the rectifier circuit 104 . The first diode 212 has an anode 226 connected to the second input 120 of the rectifier circuit 104 and a cathode 228 connected to the first terminal 122 of the rectifier circuit 104 . The second diode 214 has an anode 230 connected to the second terminal 124 of the rectifier circuit 104 and a cathode 232 connected to the second input 120 of the rectifier circuit 104 . The third diode 216 has an anode 234 connected to the second node 222 and a cathode 236 connected to the first terminal 122 of the rectifier circuit 104 . The fourth diode 218 has an anode 238 connected to the second terminal 124 of the rectifier circuit 104 and a cathode 240 connected to the second node 222 .
FIG. 3A illustrates a conventional embodiment of the starter circuit 106 A that includes a resistor 302 , a capacitor 305 , a capacitor 306 , a diode 308 and a diac 314 . The resistor 302 is connected between the first terminal 126 of the starter circuit 106 A and a charging node 316 . The capacitor 305 is connected across the resistor 302 , and improves lamp dimming performance in a manner known in the art. The capacitor 306 is connected from the charging node 316 to the second terminal 132 of the starter circuit 106 A. The diode 308 has an anode 310 connected to the charging node 316 and a cathode 312 connected to the clamp output 128 of the starter circuit 106 A. The diac 314 is connected between the charging node 316 and the starter output 130 of the starter circuit 106 A.
A starter circuit 106 B of FIG. 3B is identical to the starter circuit 106 A shown in FIG. 3A except that the charging node 316 is connected to the charging output 129 .
FIG. 4A illustrates a preferred embodiment of the driver circuit 108 A, which includes a high-side switch, preferably a first N-channel FET (field effect transistor) 402 , a low-side switch, preferably a second N-channel FET 410 , a first bi-directional voltage clamping circuit 418 A, a second bi-directional voltage clamping circuit 432 A and a feedback transformer 446 .
The first N-channel FET 402 has a gate 404 connected to a first node 472 , a source 406 connected to the first output 134 of the driver circuit 108 A and a drain 408 connected to the first terminal 140 of the driver circuit 108 A. The second N-channel FET 410 has a gate 412 connected to the second input 138 , a source 414 connected to the second terminal 144 of the driver circuit 108 A and a drain 416 connected to the first output 134 of the driver circuit 108 A.
The first bi-directional voltage clamping circuit 418 A includes a first zener diode 420 having an anode 422 connected to a second node 474 and a cathode 424 connected to the first node 472 ; and a second zener diode 426 A having an anode 428 A connected to the second node 474 and a cathode 430 A connected to the first output 134 of the driver circuit 108 A. This arrangement of diodes is known as a “back to back” connection. The second bi-directional voltage clamping circuit 432 A includes a third zener diode 434 having an anode 436 connected to a third node 476 and a cathode 438 connected to the second input 138 of the driver circuit 108 A; and a fourth zener diode 440 A having an anode 442 A connected to the third node 476 and a cathode 444 A connected to the second terminal 144 of the driver circuit 108 A.
The feedback transformer 446 includes a first winding 448 having a first terminal 450 and a second terminal 452 , a second winding 454 having a first terminal 456 and a second terminal 458 , a third winding 460 having a first terminal 462 and a second terminal 464 , and a fourth winding 466 having a first terminal 468 and a second terminal 470 . The first terminal 450 of the first winding 448 is connected to the second terminal 144 of the driver circuit 108 A. The second terminal 452 of the first winding 448 is connected to the second input 138 of the driver circuit 108 A. The first terminal 456 of the second winding 454 is connected to the ground reference node 116 . The second terminal 458 of the second winding 454 is connected to the first input 136 of the driver circuit 108 A. The first terminal 462 of the third winding 460 is connected to the first node 472 . The second terminal 464 of the third winding 460 is connected to the first output 134 of the driver circuit 108 A. The first terminal 468 of the fourth winding 466 is connected to the first output 134 of the driver circuit 108 A. The second terminal 470 of the fourth winding 466 is connected to the second output 142 of the driver circuit 108 A.
The first winding 448 , the second winding 454 , the third winding 460 and the fourth winding 466 of the feedback transformer 446 are arranged so that current flowing into the first terminal 136 of the second winding 454 causes current to flow out of terminal 452 into node 412 and out of node 404 into terminal 462 .
FIG. 4B illustrates an alternative embodiment of the driver circuit 108 B. The embodiment shown in FIG. 4B is identical to the embodiment shown in FIG. 4A except that the second zener diode 426 A and the fourth zener diode 440 A may be replaced by a first silicon diode 426 B in series with a first resistor 480 and a second silicon diode 440 B in series with a second resistor 484 respectively. Also, the source 414 of the first N-channel FET 410 is connected to the ground reference node 116 ; and the anode 436 of the third zener diode 434 and the anode 442 B of the second silicon diode 440 B are connected to the second terminal 144 of the driver circuit 108 B.
FIG. 4C illustrates another alternative embodiment of the driver circuit 108 C. The embodiment shown in FIG. 4B is identical to the embodiment shown in FIG. 4A except that the second zener diode 426 A and the fourth zener diode 440 A are in series with the first resistor 480 and the second resistor 484 respectively. Also, the source 414 of the first N-channel FET 410 is connected to the ground reference node 116 ; and the cathode 444 A of the third zener diode 440 A are connected to the second terminal 144 of the driver circuit 108 B.
FIG. 5A illustrates a preferred embodiment of the sensing circuit 110 A, which includes a first resistor 502 , a second resistor 506 , a first diode 508 which is preferably a schottky diode, a first capacitor 514 , a third resistor 516 , a second capacitor 520 , a fourth resistor 522 , an NPN transistor 524 , a PNP transistor 532 , a fifth resistor 540 , a third capacitor 542 , a fourth capacitor 544 and a second diode 546 .
The first resistor 502 is connected between the first terminal 148 of the sensing circuit 110 A and the second terminal 150 . of the sensing circuit 110 A. The second resistor 506 is connected between the first terminal 148 of the sensing circuit 110 A and a first node 552 . The first diode 508 has an anode 510 connected to the first node 552 and a cathode 512 that is connected to a second node 554 . The first capacitor 514 is connected between the second node 554 and the second terminal 150 of the sensing circuit 110 A. The third resistor 516 is connected between the second node 554 and a third node 556 . The second capacitor 520 is connected between the third node 556 and the second terminal 150 of the sensing circuit 110 A. The fourth resistor 522 is connected between the third node 556 and the second terminal 150 of the sensing circuit 110 A. The NPN transistor 524 has a base 526 connected to the third node 556 , an emitter 528 connected to the second terminal 150 of the sensing circuit 110 A and a collector 530 connected to a fourth node 558 . The PNP transistor 532 has a base 534 connected to the fourth node 558 , an emitter 536 connected to a fifth node 560 and a collector 538 connected to the third node 556 . The fifth resistor 540 is connected between the fourth node 558 and the fifth node 560 . The third capacitor 542 is connected between the fourth node 558 and the fifth node 560 . The fourth capacitor 544 is connected between the fifth node 560 and the second terminal 150 of the sensing circuit 110 A. The second diode 546 has an anode 548 connected to the output 146 of the sensing circuit 110 A and a cathode 550 connected to the fifth node 560 . For convenience, a portion of sensing circuit 110 A that includes the fourth resistor 522 , the NPN transistor 524 , the PNP transistor 532 , the fifth resistor 540 , the third capacitor 542 , the fourth capacitor 544 and the second diode 546 is hereinafter referred to as a latch 562 .
FIG. 5B illustrates an alternate embodiment of a sensing circuit 110 B. The sensing circuit 110 B is identical to the sensing circuit 110 A except that a negative temperature coefficient (NTC) thermistor 518 has been added in parallel with third resistor 516 . The NTC thermistor 518 provides thermal protection for the converter 100 , as will be explained below in detail.
FIG. 5C shows another alternate embodiment of a sensing circuit 110 C. The sensing circuit 110 C is identical to the sensing circuit 110 A except that the first diode 508 has been replaced with a silicon diode 509 having a cathode 511 connected to the first node 552 and an anode 513 connected to the second node 554 . The silicon diode 509 also provides thermal protection for the converter 100 , as will likewise be explained below in detail.
FIG. 5D shows another alternate embodiment of a sensing circuit 110 D. The sensing circuit 110 D is identical to the sensing circuit 110 B except that the first diode 508 has been replaced with a silicon diode 509 having a cathode 511 connected to first node 552 and an anode 513 connected to second node 554 . Also, the first resistor 502 has been removed.
FIG. 5E shows still another alternate embodiment of a sensing circuit 110 E. The sensing circuit 110 E is identical to the sensing circuit 110 B except that the first resistor 502 has been removed.
FIG. 5F shows yet another alternate embodiment of a sensing circuit 110 F. The sensing circuit 110 E is identical to the sensing circuit 110 D shown in FIG. 5D except that: the third resistor 516 and the second capacitor 520 have been removed; a first zener diode 564 having an anode 564 A connected to the third node 556 and a cathode 564 B connected to the second node 554 replaces the third resistor 516 ; the NTC thermistor 518 is connected from the third node 556 to a sixth node 568 ; and a second zener diode 570 has an anode 570 A connected to the sixth node 568 and a cathode 570 B connected to the thermal shutdown terminal 147 .
FIG. 6A shows a conventional embodiment of the transformer circuit 112 A that includes a first capacitor 602 , a second capacitor 604 , and a transformer 606 . The first capacitor 602 is connected between the first terminal 154 of the transformer circuit 112 A and a node 620 . The second capacitor 604 is connected between the node 620 and the second terminal 160 of the transformer circuit 112 A. The transformer 606 has a first winding 608 having a first terminal 610 and a second terminal 612 ; and a second winding 614 having a first terminal 616 and a second terminal 618 . The first terminal 610 of the first winding 608 is connected to the input 152 of the transformer circuit 112 A. The second terminal 612 of the first winding 608 is connected to the node 620 . The first terminal 616 of the second winding 614 is connected to the first output 156 of the transformer circuit 112 A. The second terminal 618 of the second winding 614 is connected to the second output 158 of the transformer circuit 112 A.
FIG. 6B shows an alternative embodiment of the transformer circuit 112 B. The first capacitor 602 is connected between the first terminal 154 of the transformer circuit 112 A and a first node 620 . The second capacitor 604 is connected between the first node 620 and the second terminal 160 of the transformer circuit 112 B. A transformer 630 has: a first winding 632 having a first terminal 632 A connected to the first node 620 and a second terminal 632 B connected to the input 152 of the transformer circuit 112 B; a second winding 634 having a first terminal 634 A connected to the second output 158 of the transformer circuit 112 B and a second terminal 634 B connected to a second node 658 ; a third winding 636 having a first terminal 636 A connected to a third node 666 and a second terminal 636 B connected to the second output 158 of the transformer circuit 112 B; a fourth winding 638 having a first terminal 638 A connected to the second node 658 and a second terminal 638 B connected to a fourth node 646 ; and a fifth winding 640 having a first terminal 640 A connected to a fifth node 652 and a second terminal 640 B connected to the third node 666 . The transformer circuit 112 B also includes: a first N-channel FET 642 having a gate 642 A connected to a sixth node 650 , a source 642 B connected to the seventh node and a drain connected to the first output 156 of the transformer circuit 112 B; a second N-channel FET 644 having a gate 644 A connected to a seventh node, a source 644 B connected to the third node 666 and a drain connected to the first output 156 of the transformer circuit 112 B; a first resistor 648 connected between the fourth node 646 and sixth node 650 ; a second resistor 654 connected between the fifth node 652 and the seventh node 656 ; a third capacitor 660 connected between a the second node 658 and a eighth node 662 ; and a third resistor 664 connected between the eighth node 662 and the third node 666 .
The first winding 632 , the second winding 634 , the third winding 636 , the fourth winding 638 , and the fifth winding 640 of the transformer 630 are arranged so that current flowing into the first terminal 632 A of the first winding 632 causes current to flow out of the first terminal 634 A of the second winding 634 , the first terminal 636 A of the third winding 636 , the first terminal 638 A of the fourth winding 638 , and the first terminal 640 A of the fifth winding 640 .
In operation, the rectifier circuit 104 ( FIG. 1 ) receives a 60 Hz, 120V power main voltage applied to first and second inputs 118 , 120 and outputs a semi-sinusoidal voltage 702 at 120 Hz, as shown in FIG. 7 . In FIG. 7 , the x-axis 704 represents time (seconds) and the y-axis 706 represents voltage (Volts). The operation of the rectifier circuit 104 is understood by those skilled in the art.
Oscillation of the driver circuit 108 A starts each cycle when the voltage applied to the charging node 316 in the starter circuit 106 A rises sufficiently to turn on the diac 314 . When the diac 314 turns on, a pulse of current is provided to the second winding 454 of the feedback transformer 446 . The pulse of current is coupled through the third winding 460 to the gate 404 of the first N-channel FET 402 and through the second winding 454 to the gate 412 of the second N-channel FET 410 . The direction of the third winding 460 and the second winding 454 are selected so that the pulse of current from the starter circuit 106 A will turn off the first N-channel FET 402 and turn on the second N-channel FET 410 . This causes the voltage on the first output 134 of the driver circuit 108 A to fall. If a load, such as a lamp 114 , is connected to the first and second outputs 156 , 158 of the transformer circuit 112 , then a driver output current will flow through the fourth winding 466 . The direction of the fourth winding 466 is selected so that a positive feedback is supplied to the gate 404 of the first N-channel FET 402 and the gate 412 of the second N-channel FET 410 . The voltage of the first output 134 of the driver circuit 108 A falls to the voltage of the ground reference node 116 . After a period of time determined by the size and a maximum flux density of the core used in the feedback transformer 446 , the feedback to the gate 404 of the first N-channel FET 402 and the gate 412 of the second N-channel FET 410 is removed. The voltage of the first output 134 of the driver circuit 108 A starts to rise, creating a positive feedback that turns on the first N-channel FET 402 and turns off the second N-channel FET 410 . The voltage of the first output 134 of the driver circuit 108 A rises to the voltage of the power supply node 117 . Again, after a period of time determined by the size and the maximum flux density of the core used in feedback transformer 446 , the feedback to the gate 404 of the first N-channel FET 402 and the gate 412 of the second N-channel FET 410 is removed. The voltage of the first output 134 of the driver circuit 108 A then starts to fall, creating positive feedback that turns off the first N-channel FET 404 and turns on the second N-channel FET 410 . Thus, oscillation is established at an operating frequency in the driver circuit 108 . If no load is present, there is no positive feedback and no oscillation occurs.
Once oscillation has been established, the diode 312 of the starter circuit 106 A ( FIG. 3 ) maintains a voltage of the charging node 316 of the starter circuit 106 A at a value that is less than a conduction threshold voltage of the diac 314 .
Voltage waveform 802 of the first output 134 of the driver circuit 108 A is shown in FIG. 8 , in which the x-axis 804 represents time (seconds) and the y-axis 806 represents voltage (Volts). The resulting current waveform 902 in the lamp 114 is shown in FIG. 9 , wherein the x-axis 904 represents time (seconds) and the y-axis 906 represents current (Amperes). It should be noted that the operating frequency illustrated in FIGS. 8 , 9 , and 10 is much lower than the normal operating frequency for purposes of clarity, and that normal operating frequency is preferably greater than 43 kHz.
The converter 100 provides current overload protection. When a current overload condition occurs, such as a short circuit between the first and second outputs 156 , 158 of transformer circuit 112 causing the output current of driver circuit 108 A to rise above a predetermined threshold, a voltage across the first resistor 502 of the sensing circuit 110 A ( FIG. 5A ) is large enough to turn on the first diode 508 of the sensing circuit 110 A. The first capacitor 514 and the second capacitor 520 are charged so that latch 562 is triggered. The triggering of latch 562 causes current to be drawn into the output 146 of the sensing circuit 110 A and to reduce voltage on the gate 412 of the second N-channel FET 410 and the gate 404 of the first N-channel FET 402 by mutual coupling (FIG. 4 ). This turns off the second N-channel FET 410 , which causes the voltage on the first terminal 148 of the sensing circuit 110 A to decrease, oscillation of the driver circuit 106 then stops, which turns off the first diode 508 of the sensing circuit 110 A. After a period of time determined by values of the first capacitor 514 , the third resistor 516 , the second capacitor 520 , the fourth resistor 522 , the fifth resistor 540 , the third capacitor 542 , the fourth capacitor 544 , and the extent to which the output current of the driver circuit 106 exceeded the predetermined threshold, the latch 562 re-sets to permit oscillation of driver circuit 106 to re-start. The resulting waveform 1002 of the voltage across the lamp 114 is shown in FIG. 10 , wherein the x-axis 1004 represents time (seconds) and the y-axis 1006 represents voltage (Volts). The voltage across the lamp 114 is thus pulse-width modulated by the current limiting signal on the output 146 of the sensing circuit 110 A.
The embodiment shown in FIG. 5B introduces the NTC thermistor 518 to provide temperature protection for the converter 100 . The NTC thermistor 518 is placed in good thermal contact with converter 100 . As the temperature of the converter 100 rises, the impedance of the NTC thermistor 518 is reduced. This has the effect of reducing the predetermined threshold for the current overload condition described above. Consequently, as the temperature of the converter 100 increases beyond a threshold determined by resistance characteristics of the NTC thermistor 518 , the driver output current provided to the lamp 114 is reduced, permitting the converter 100 to cool. As cooling occurs, the driver output current is increased. The cycle automatically repeats, as required.
In the embodiment shown in FIG. 5C , the silicon diode 509 serves the same function as the NTC thermistor 518 . The silicon diode 509 is placed in good thermal contact with the converter 100 . As the temperature of the converter 100 rises, the switching threshold of the silicon diode 509 is reduced. This also has the effect of reducing the predetermined threshold of the current limiting circuit described above, to provide thermal protection as described with reference to FIG. 5 B.
The embodiment shown in FIG. 5D functions substantially the same as the embodiment shown in FIG. 5 B. The removal of the first resistor 502 permits the use of the silicon diode 509 having a higher forward voltage than the schottky diode 508 .
The embodiment shown in FIG. 5E functions substantially the same as the embodiment shown in FIG. 5 B.
In the embodiment shown in FIG. 5F , the current sensing functions substantially the same as in the embodiment shown in FIG. 5 C. However, the thermal protection functions differently. When the impedance of the thermistor 518 is reduced as the temperature of the converter 100 rises above a predetermined threshold, the latch 562 is triggered by a voltage of the shutdown node 127 .
The embodiment of the driver circuit 108 B shown in FIG. 4B has the advantage sensing the driver output current indirectly. That is, the driver output current is fed back via the fourth winding 466 of the transformer 468 through the first winding 448 to the second bi-directional voltage clamping circuit 432 . The second resistor 484 of the driver circuit of FIG. 4B is used for sensing the driver output current instead of the first resistor 502 of the sensing circuits shown in FIGS. 5A , 5 B, and 5 C.
The embodiment of the driver circuit 108 A shown in FIG. 4A is used in conjunction with the embodiment of the starter circuit 106 A shown in FIG. 3 A and with the embodiments of the sensing circuit 110 A, 110 B, or 110 C shown in FIGS. 5A , 5 B and 5 C respectively. The embodiment of the driver circuit 108 B shown in FIG. 4B is used in conjunction with the embodiment of the starter circuit 106 A shown in FIG. 3 A and with the embodiments of the sensing circuit 110 D or 110 E shown in FIGS. 5D and 5E respectively. The embodiment of the driver circuit 108 C shown in FIG. 4C is used in conjunction with the embodiment of the starter circuit 106 B shown in FIG. 3 B and with the embodiment of the sensing circuit 110 F shown in FIG. 5 F.
The embodiment of the transformer circuit 112 A shown in FIG. 6A is used in conjunction with any of the above combinations of starter circuits 106 A or 106 B, driver circuits 108 A, 108 B or 108 C and sensing circuits 110 A, 110 B, 110 C, 110 D, 110 E or 110 F for providing an AC voltage suitable for driving the lamp 114 . The embodiment of the transformer circuit 112 B shown in FIG. 6B is used in conjunction with any of the above combinations of starter circuits 106 A or 106 B, driver circuits 108 A, 108 B or 108 C and sensing circuits 110 A, 110 B, 110 C, 110 D, 110 E or 110 F for providing a DC voltage suitable for driving the lamp 114 wherein the first output 156 is a positive terminal and the second output 158 is a negative terminal.
The embodiment shown in FIG. 6B functions as a synchronous full-wave rectifier, in which the fourth winding 638 provides a gating voltage to the first FET 642 and the fifth winding 640 provides a gating voltage to the second FET 644 . The third capacitor 660 and second resistor 664 provide filtering of the DC voltage.
The invention also provides a method for controlling an output voltage of the driver circuit 106 to provide current limiting protection for the converter 100 . FIG. 11 is a flowchart 1100 illustrating the method. The method starts (step 1102 ) when power is supplied to the AC inputs 118 , 120 of the rectifier 104 . The driver output current is sensed (step 1104 ) by the sensing circuit 110 A, 110 B, 110 C, 110 D, 110 E, or 110 F to determine whether the sensed driver output current exceeds a threshold (step 1106 ) determined by the component values of the components of the sensing circuit 110 A, as described above. If the driver current is not greater than the threshold, the sensing of the driver output current continues (step 1104 ). If, however, the sensed driver output current exceeds the threshold, then the extent to which the driver output current exceeds the threshold is sensed (step 1108 ). The latch 562 is triggered when the sensed driver output current exceeds the threshold. This stops an oscillation of the driver circuit (step 1110 ). The latch 562 is re-set after a period of time related to an extent to which the driver output current exceeded the threshold (step 1112 ). Meanwhile, the sensing circuit 110 A continues to sense the driver output current (step 1102 ).
As explained above, if the NTC thermistor 518 ( FIGS. 5B , 5 D, 5 E, or 5 F) or the silicon diode 509 ( FIG. 5C ) are added to the sensing circuit 110 , the converter 100 is further provided with temperature protection, which permits the converter 100 to continue to operate at elevated temperatures without component damage. Experimentation has shown that the converter 100 in accordance with the invention can be operated for extended periods of time at case temperatures of at least 110° C., provided that the sensing circuit 110 is constructed as shown in FIGS. 5B , 5 C, 5 D, 5 E, or 5 F.
The invention therefore provides a simple, high-frequency, light-weight, compact converter 100 that is inexpensive to construct and more robust than converters known from the prior art. The high operating frequency permits all capacitors: 306 shown in FIGS. 3A and 3B ; 514 , 520 , 542 , 544 shown in FIGS. 5A-F ; 602 , 604 shown in FIGS. 6A and 6B ; and 606 shown in FIG. 6B ; to be solid-state non-polarized capacitors, thereby reducing the weight and package size of the converter 100 .
The embodiment(s) of the invention described above is (are) intended to be exemplary only. The scope of the invention is therefore intended to be limited solely by the scope of the appended claims.
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An electronic converter converts high-voltage AC power main voltage, such as 120V, 240V or 277V, to a low-voltage suitable for driving a halogen lamp. The converter includes a rectifier circuit, starter circuit, a driver circuit, a current sensing circuit and a transformer circuit with an optional synchronous output rectifier. The current sensing circuit senses an output current of the converter. The sensed current is used to govern pulse-width modulation of the lamp drive voltage, to provide over-voltage protection. Temperature protection can also be provided to reduce drive current when the converter overheats. This enables reliable operation of the converter over an extended temperature range, and reduces the occurrence of converter component failures due to ground faults or overheating.
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This is a division of application Ser. No. 07/434,514, filed Nov. 14, 1989, now U.S. Pat. No. 5,092,899, which is a continuation-in-part application of co-pending U.S. application Ser. No. 849,172 filed Apr. 7, 1986 now abandoned.
BACKGROUND OF THE INVENTION
This invention relates, generally, to a prosthesis and more particularly to a bone prosthesis having an intramedullary fixation stem which is somewhat flexible and also comparable in flexibility to that of the surrounding supportive cortical bone. This structure gives great advantages and overcomes the difficulties encountered with prior art devices as will be more fully described and explained herein below.
Heretofore, prosthesis components and particularly femoral prosthesis components which are utilized for surgical reconstruction of a human hip joint have incorporated solid and relatively stiff intramedullary fixation stems. These stems are fabricated of suitable, compatible metallic alloys and are generally integral with the prosthetic neck and head portions. Therefore, the stems of these components are stiff, that is, they do not provide significant flexure along the length of the stem. However, the surrounding support of cortical bone within which they are implanted does offer some flexibility. Therefore, stiff stems, relative to the more flexible structure of the cortical bone, result in a composite structure wherein the flexural rigidity of the constituent parts varies significantly, depending upon prosthesis stem factors related to sectional size, shape, thickness and material modulus of elasticity.
The use of relatively stiff intramedullary stems has been clinically suspect of producing adverse and destructive bone reactions over a long period of time. More particularly, stiff stems can be attributed to producing micromotion at the stem and bone interface and can also be attributed to the development of reduced levels of force or stress shielding within the surrounding support of bone structure. Both the presence of interlace micromotion and reduced bone stresses can result in adverse bone reactions which have been attributed to the diminution of bone mass at the interface and also within the surrounding bone matrix. Understandably, loss of bone is detrimental to the function of the implant and can produce loosening of the prosthesis and accompanying loss of articular joint or hip function and also results in severe pain. Depending upon the severity of these functional factors, surgical revision may be indicated.
The reaction forces between an implant stem and supportive bone are preferably distributed in such a manner that the greater forces are transferred proximally and decrease uniformly along the length of the fixation stem distally. This force distribution allows a greater proportion of joint reaction force to be transferred to the surrounding supportive cortical bone to levels comparable to that of an intact femur. It is most important for maximum advantages to have a uniformly flexible stem with relatively greater flexibility proximately than distally.
This therefore avoids adverse postoperative bone reaction which has been attributed to the stress shielding phenomenon of relatively stiff conventional hip stems. However, conventional relatively stiff stems reduce the forces distributed to surrounding bone to levels significantly below normal anatomical levels of an intact femur. Therefore, under the influence of reduced levels of bone stress distribution incident to stiff conventional stems, adverse bone reaction may occur postoperatively where the adjacent bone structure degenerates, diminishes or atrophies. This resultant bone loss can seriously affect the structural integrity of the adjacent supportive bone and may ultimately lead to significant loss or compromise of stem fixation. The loss of stem fixation will eventually compromise the long-term function of the implant prosthesis if the resulting pain and/or also loss of function becomes significantly intolerable to the patient.
The present invention therefore incorporates a flexible fixation stem which is integral to the metal prosthetic component neck and head portions. This stem flexibility significantly reduces the micromotion at the stem and bone interface while increasing the levels of force transferred to the adjacent supportive bone structure. This reduction of interface micromotion and the attainment of higher levels of bone force or stress over the entire bone can significantly improve the attainment and sustainment of stem fixation in a number of cementless modes, such as bony ingrowth fixation or press fit fixation. Heretofore the use of relatively stiff stems as are present in prior art and known devices now in use compromised good long-term results in hip joint reconstruction, where the adjacent bone has been adversely affected by the presence of intolerable micromotions at the fixation interface and from stress shielding within the adjacent supportive bone structure.
Accordingly, a number of devices have been utilized which attempt to provide a prosthesis having some flexibility. Examples of these devices may be found in U.S. Pat. Nos. 4,530,114, "Total Hip Joint Prosthesis", issued Jul. 23, 1985 to Tepic; 4,287,617, "Femoral Pin for Hip Prosthesis", issued Sep. 8, 1981 to Tornier; 4,261,063, "Titanium or Titanium Alloy Pin to be Fixed in Long Bones", issued Apr. 14, 1981 to Blanquaert; 3,965,490, "Femural Insert for Hip Joint Prosthesis", issued Jun. 29, 1976 to Murray et al: and 3,893,196, "Body Implant Material", issued Jul. 8, 1975 to Hochman.
The Tepic reference provides for flexure through the use of tension transmitting wires. The Tornier reference utilizes bent sheet metal having a longitudinal slit therein, in an attempt to give the prosthesis some elasticity or flexibility. The Blanquaert reference utilizes a lattice of titanium wire in an attempt to have a modulus of elasticity close to that of the cortical bone tissue. The Hochman reference, while directed to an implant material, attempts to produce an implant material having a module of elasticity which is comparable to that of the cortical bone.
The Tornier reference shows a U-shaped sheet metal femoral component with an opening on the lateral side. The reason for this design is to provide a relatively stiff proximal end. The shape is designed with the objective to provide transverse elasticity, thus having the intent of facilitating positioning of the stem into the medullary canal and thus give a tight fit with the anticipated advantage of a certain "springiness" to the inserted device.
The Hochman et al patent describes a graphite or boron fiber-plastic composite fabrication of several conventional hip prosthesis design, a hip fracture fixation device and an intramedullary fracture fixation rod for long bones. The stem portion of the prosthesis will be somewhat more flexible than its equivalent metal counterpart, but this is accomplished in a different manner by utilizing a more compliant, flexible material of construction.
Other prior art which attempts to disclose and describe devices similar to, related to, or having one or more features of this invention include, U.S. Pat. Nos. 2,066,962, "Shaft for Golf Clubs or the Like", issued Jan. 5, 1937 to Cross; 4,375,810, "Joining Element for Fixation of Bone Tissues", issued Mar. 8, 1983 to Belykh et al; and 4,562,598 "Joint Prosthesis" issued Jan. 2, 1986 to Kranz, German patent no. 2,933,237 to Hoogeveen et al; French patent no. 2,483,218 to Cuilleron; German patent no. 2,636,644 to Heibler et al; German patent no. 2,558,446 to "Pifferi et al; German patent no. 2,015,324 to Timmermans et al; European patent no. 0065481 to Anapliotis et al and European patent no. 0077868 to Godolin.
None of these devices describe or suggest the invention of this application or the devices described and claimed herein.
The Hoogeveen et al patent describes a hollow stem which has a modulus of elasticity conforming to the modulus of the surrounding bone. First of all, in this patent, the term "modulus of elasticity" is somewhat incorrectly used. It represents a property of an elastic material such as metal or bone which is the ratio of stress to strain. By using such a term, the inventor has inferred that the stem of invention device has a stiffness or flexibility of that of the surrounding bone. Thus, the inventors state that in their device the shank component in the proximal section must have particularly high rigidity from its contour and nature of the material. In the bottom section the shank should have only low rigidity, or only a low modulus of elasticity.
On the other hand and quite the opposite in structure, and result, in the device of this invention, the stem at the distal end may be intentionally solid and rigid. Preferably, for maximum cementless fixation advantage, the flexible end is the proximal end with more rigidity in the distal end to minimize interface shear and maximize low transfer to the supporting cortical bone as required to maintain stem support by osseous integration or press fit. If severe osteoporosis is present, one advantage would be to have the entire stem flexible, since all the intact bone is flexible from bone (calcium) loss and flexual matching is especially important for the entire length of the device stem.
The Cuilleron patent shows a femoral prosthesis component which incorporates a sagittal slot. The stated purpose of this slot is to "make the stem elastic, expanding in the medullary canal so as to anchor it without the use of any sealing agent" (bone cement). The forces normally acting on the hip joint in use would in fact, react to close the split stem and therefore would obviously produce a loss of stem fixation from the ensueing collapse of the structure.
The Heibler et al patent describes a composite fiber hip prosthesis of carbon ceramic, MOS 2 , or aromatic polyamide fibers combined with a compatible matrix of polyamides or expoxy resin. The hip stem has a hollow distal end to improve intramedullar fixation. Here again, the flexible portion is distally, not proximally used and is incorporated to improve stem fixation within the bone.
The Pifferi et al reference also does not suggest or describe the features of the invention and neither do the Timmermans et al Kranz, or Anapliotis patents relate to this invention except to generally disclose well-known hollow stem devices.
The Godolin European Patent shows a device in which the stem has incorporated therein an expansion screw-actuated taper mechanism to provide a tight fit within the medullary canal of the femur. Frustro conical segments expand radially upon tightening of a screw connected to an expansion cone and mandrel interface. Further, as described, the orientation of the frustro-conical segments are inappropriate to provide stability of the implant or preventing subsidence of and within the bone implantation in situ. If the screw arrangement were reversed, the operability of the device would be more positive.
However, all of these devices have one or more disadvantages in that they are expensive to manufacture, difficult to manufacture, unworkable from a clinical standpoint, or the like. Furthermore, none of them incorporate, describe, or suggest the devices disclosed herein for this invention nor do they give the advantages obtained by use of the herein described devices.
SUMMARY OF THE INVENTION
Therefore, it would be advantageous and it is an object of the present invention to produce a device which incorporates an integral, metallic alloy stem having a sectional design which provides flexural rigidity comparable to the surrounding support bone.
It is another object of the present invention to produce a composite structure of bone and metallic stem which are functionally identical in terms of bending and torsional deformation under the influence of active load forces.
It is still a further object of the present invention to produce a device having comparable flexural characteristics between the cortical bone and the metallic stem which will improve the long-term postoperative course of the prosthetic device.
It would also be advantageous to produce an implantable device which reduces, minimizes or eliminates the interface shear forces at the bone and stem interface.
It is also advantageous to produce an implant having a porous surface which is incorporated on the exterior surface of a flexible stem for ingrowth of bone to achieve fixation.
It is still a further object to produce a device which improves the quality of adjacent bone and/or the quality of the adjacent bony ingrowth while significantly reducing the postoperative time for subsequent bone remodeling to occur.
It would also be advantageous to produce a prosthesis which improves the distribution of the interface reaction forces between the stem and the bone.
It would also be advantageous to produce a hip or joint prosthesis, having a first portion for use exterior to a bone and a second portion contoured to be disposed within a bone, characterized in that the second portion is generally annular and axially tapering from a first diameter adjacent the first portion. The second portion has a bore in a portion thereof wherein the bore provides flexibility of the second portion which is comparable to the bone in which the second portion is disposed. Such a device is taught by the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
Reference is now made to the accompanying figures, in which:
FIG. 1A is an elevational view of the hip implant prosthesis of the present invention;
FIGS. 1B, 1C and 1D are top and cross-sectional views, respectively, of FIG. 1A;
FIG. 1E is a cross-sectional view of the implant of FIG. 1A when in a femur;
FIG. 2 is a cross-sectional view through the implant of FIG. 1A;
FIG. 3A is a side elevational view of an alternate embodiment of the present invention illustrating a collar portion;
FIGS. 3B, 3C and 3D are top and cross-sectional views, respectively, of FIG. 3A;
FIG. 3E is an illustrative view of the implant of FIG. 3A when disposed in a femur;
FIG. 4A is a cross-sectional view of an alternate embodiment of the implant of the present invention showing how the bore therein is sealed;
FIG. 4B is a top view taken through FIG. 4A;
FIG. 5A is another alternate embodiment of the present invention illustrating a porous surface;
FIG. 6A is an elevational, partly cross-sectional view of a further alternate embodiment of the present invention showing an external porous surface and proximal and distal internal porous surfaces;
FIG. 7A is an additional alternate embodiment of the present invention shown in elevation and having a filament wound thereon;
FIG. 8A is a cross-sectional view taken through another alternate embodiment of the present invention having a longitudinal slit therein;
FIG. 8A' is the view of FIG. 8A showing how the bore therein is sealed.
FIGS. 8B, 8C and 8D are top and cross-sectional views, respectively, of FIG. 8A; and these figures are believed to incorporate many of the most important parts of the invention device.
FIG. 9A is still another alternate embodiment of the present invention showing openings in the stem; and
FIGS. 9B and 9C are top and cross-sectional views taken through FIG. 9A, respectively.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1A, there is shown a side elevational view of a hip joint prosthesis of the present invention. The prosthesis or implant is shown generally at 10 and has at one end a femoral head 12. The neck portion 14, which may be considered as facing the medial side of the prosthesis 10, forms an intermediate portion between the femural head 12 and a collarless transition joint at 18. The stem portion 16 has a bore 26 therein. The bore 26 may extend to different depths in the stem 16 as indicated by first bore depth 22, second or intermediate bore depth 24 or a bore through the distal end at 25.
The stem 16 is of a certain wall thickness 20 and generally tapers at a taper angle Theta (θ). The taper angle Theta (θ) may vary up to 5° which therefore results in an upper wall thickness 28, an intermediate wall thickness 29, and a distal wall thickness 30 which may be uniform or different from each other. It is this wall thickness 20, which may be considered as being disposed in a radial manner, and the bore 26 which aid in providing flexibility of the stem. It has been found that the ratio of internal diameter to outside diameter can be varied, depending upon the stiffness desired, and it preferably ranges up to 0.95 inches per inch, relative to the distal end as desired. Additionally, the stiffness along the stem 16 length may be varied by adjusting the depth of the internal cavity and hence partial depths 22, 24 and 25 may be employed. By referring to FIGS. 1B, 1C and 1D, the wall thickness 20 may be more clearly seen. Further, the distal end of the stem 16 is tapered at an angle alpha which preferably ranges up to 5 degrees.
Referring now to FIG. 1E, there is shown the implant of the present invention in use in a femur. Here, the stem 16 is disposed inside the femur 32 and forms a relatively snug fit which preferably forms a force fit therebetween. It is preferred that a press fit mode between the stem 16 and the bone 32 be utilized as opposed to the use of cement, although both modes are acceptable. The collarless transition joint 18 is disposed at the top part of the stem 16 just as the stem 16 emerges from the femur 32.
Accordingly, the prosthesis or implant 10 incorporates an integral metallic fixation stem of hollow construction. This is distinct from conventional, essentially more or less solid metallic fixation stems of the prior art. It has been found that by varying the sectional geometry, section thickness, material of construction and depth of the internal cavity or bore in the stem 16, predetermined levels of flexibility may be provided. It has also been found that by more closely approximating the flexibility of the adjacent support of cortical femoral bone, a significant reduction of interface micromotion between the bone 32 and the stem 16 will result. Also, a significant improvement in the level of stress developed between the surrounding bone structure will result. By reducing the interface micromotion as mentioned and improving bone loading so as to more closely match that of a natural femur, the prosthesis clinical performance and reliability may be improved. While the stem 16 may be manufactured of different materials, it is preferred that stainless steel, cobalt-chrome alloys or titanium alloys be utilized.
FIG. 2 shows a cross-sectional view taken through FIG. 1A. More clearly observable is the thickness 20 of the metal alloy 34.
Referring now to FIG. 3A, there is shown an alternate embodiment of the present invention. Here, the implant joint is shown generally at 11. This embodiment is essentially the same as that of FIG. 1, with the exception that a collared transition joint 36 is utilized. This collar 36 provides additional stem 16 support with respect to the medial bone shelf as shown in FIG. 3E. Also, as can be seen in FIGS. 3B, 3C and 3D, are the top and cross-sectional views of FIG. 3A which are essentially identical to that of FIG. 1.
Referring now to FIGS. 4A an alternate embodiment of the present invention is shown at 13. Here, the implant 13 is generally the same as that of FIG. 1A with the exception that a proximal closure 38 is disposed at the top of the bore 26. The closure 38 is comprised of a closure bore 40 on the underside having closure extensions or legs 42, 44. Therefore, the closure 38 may be force-fit into the bore 26 and allows for the extensions 42, 44 to "collapse or compress" slightly. Disposed at the distal end of the stem 16 is an integral distal closure 45 which is formed when the bore 26 is not drilled to the extent shown in FIG. 1A. The bore 26 is closed in the manner shown so as to prevent the possible capture of biological fluids in certain clinical situations where the patient is at high risk of infection.
FIG. 8A' shows a similar bore closure.
Referring now to FIG. 5, a porous implant is shown generally at 15. This implant is essentially the same as in FIG. 1A with the exception that a portion of the stem 16 has a porous surface 46. This porous surface 46 provides a conventional tissue ingrowth type of implant. Therefore, ingrowth of bone into the integral porous surfaces may be achieved since the present invention provides implant stability, as well as maintaining close proximity to adjacent bone, as previously mentioned. Therefore, use of the porous surface 46 in conjunction with the flexible stem 16 will substantially improve ingrowth mechanics due to the reduced micromotion of the stem 16 and bone interface. This will also result in reduced postoperative time to achieve bone remodeling and ingrowth. Additionally, this combination may provide improved structure and strength of the ingrowing and surrounding bone.
Referring now to FIG. 6, a porous implant having open ends is shown generally at 17. This implant 17 is essentially the same as that in FIG. 5 with the exception that a proximal end porous surface 48 is disposed at the top of the bore 26 while a distal end porous surface 50 is at the lower end of the stem 16. The presence of the partial porous surfaces 48 and or 50, within the bore 26 is utilized to enhance stem fixation by enhancing resistance to transverse movement as well as subsidence or sinking instability. These interior and exterior porous surfaces consist of conventional types of interfused spherical compatible metallic particles and are preferably in the 200-800 micron range.
The concept of a macro surface structure or a micro surface structure such as a porous coated surface at the proximal end, where the section is relatively equal in flexibility as compared to the adjacent bone, is of great importance. The concept is also important with respect to the relative rigidity at the distal end of the device.
As a typical and most important, defined and descriptive detail, and improvement, the device is somewhat larger at the proximal end and tapered somewhat to a smaller portion at the distal end. This form provides great advantages for the invention.
Referring now to FIG. 7, a filament type prosthesis or implant is shown generally at 19. This implant 19 is structurally the same as FIG. 1 with the exception of filament 52 which is wound onto the stem 16. The filament 52 is wound in separate directions so as to be essentially in a biased first direction 54 and a biased second direction 56. The two biased elements 54, 56 are biased with respect to each other at an angle Beta (β) which preferably may be in a range of up to 45°. The filament 52 is a small diameter metallic or nonmetallic biologically compatible material, such as 6AL-4V titanium alloy or carbon, which are conventional materials available from a number of manufacturing sources. The spacing between adjacent windings of the filament 52 may be adjusted up to 1 mm so as to provide a lattice structure for tissue ingrowth fixation. Further, the filament winding 52 may provide or augment the structural strength of the stem 16, particularly in those situations where section thickness 20 is 1/2 millimeter or less. However, this does not totally define or comprise the invention and the device design.
Referring now to FIGS. 8A-8C, a compressible implant is shown generally at 21. Here, the overall structure is similar to that of FIG. 1A. However, as can be seen from FIGS. 8B, 8C and 8D, a longitudinal slit or opening 58 is formed in one side of the outer wall. This lateral opening or slit 58 may extend through the entire stem 16 or may only go as far as bore depths 22 or 24 or 25 as shown in FIG. 1A. This slit 58 extends from the exterior of the stem 16 through the wall and to the bore 26. It should be pointed out that it is most important and in fact vital to achieve the advantages of this invention, to have the opening of the stem device on the lateral side for improved torsional constraint once bone infiltration has occurred. Furthermore, an opening on the medial side can detract from the bearing area between the stem and bone producing indesirable high unit loading proximally. This also is a very important difference and distinction over prior art devices. The opening 58 reduces the radial stiffness at a given transverse section, thereby enhancing the interference or wedge fit of the stem 16 with the cortical bone. The longitudinal opening 58 may also reduce the resultant hoop stresses within the cortical shaft during press fitting, thereby minimizing interoperative harm from premature bone fracture. Again, the implant 21 is made of stainless steel, cobalt-chrome alloys or titanium alloys which have been milled or cast accordingly. The longitudinal opening or slit 58 also enhances the torsional stability or fixation of the hip implant 21. Further, the channel or spacing allows bone remodeling through an intrusion of the bone therein. The depth and the length of the groove or slot may be continuous or interrupted or inclined. Additionally, the width of the opening 58 may vary and is preferably from 1-10 millimeters.
Referring now to FIGS. 9A-9C, a perforated implant is shown generally at 23. The overall shape of the implant 23 is similar to that of FIG. 1A. A distal end closure 60 is at one end of the bore 26. At various heights along the stem 16, there are provided openings 62 which are preferably on the anterior and posterior surfaces of the stem 16. The bore 26 and openings 62 are provided for storage and in vivo release of various bioactive substances to enhance bone remodeling postoperatively. The openings 62 also provide the chance for the storage and subsequent release of antibiotic substances in instances where the patient is at high risk of infection. These openings 62 extend through to the bore 26 in the stem 16, as shown in FIGS. 9B and 9C.
It is to be understood that many variations of the present invention may be practiced without departing from the spirit and scope of the present invention. For example, different types of fermoral heads may be utilized while the implant may be utilized in different portions of the body, such as the shoulder or knee joint. Further, slightly different shapes or proportions may be utilized while different materials for the implant may also be used.
Although the present invention has been described in connection with a plurality of preferred embodiments thereof, many other variations and modifications will now become apparent to those skilled in the art. It is preferred, therefore, that the present invention be limited not by the specific disclosure herein, but only by the appended claims.
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An implant for a hip or other joint is provided. Briefly stated, a intramedullary stem is provided having flexibility which is comparable to that of the surrounding bone. A bore is disposed in the stem portion with the stem wall thickness uniform or varying from the proximal end to the distal end, depending upon the amount of flexibility desired. This flexibility therefore distributes the loading forces from the joint more uniformly over the supporting cortical bone with the result that bone degeneration from stress shielding is minimized or eliminated.
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CROSS REFERENCE TO RELATED PATENT APPLICATION
A patent application entitled "RF-Pumped Infrared Laser Using Tranverse Gas Flow" bearing application Ser. No. 470,409, and filed on Feb. 28, 1983 by John H. S. Wang et al and assigned to Hughes Aircraft Company describes and claims a laser upon which the present case is an improvement therefor.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates generally to the field of transverse gas flow RF pumped waveguide lasers, and specifically to continuous wave mid-infrared lasers.
2. Description of the Related Art
Transverse gas flow radio frequency excited discharge waveguide laser technology development by the assignee has included continuous wave and pulse excitation for infrared CO 2 gas lasers, and pulse excitation mid-infrared chemical lasers.
In particular, the development of such lasers began with radio frequency waveguide CO 2 gas lasers that operated in the continuous wave mode at far-infrared with a wavelength of 10.6 microns. The RF waveguide laser was then utilized as a CO 2 gas laser in the pulse mode at far-infrared with a wavelength of 10.6 microns. Next, a RF waveguide laser in the pulse in the mid-infrared was implemented with HF and DF kinetics. Finally, a transverse gas flow RF waveguide laser was developed that was able to operate in various embodiments in a pulse or continuous wave mode at far-infrared with a wavelength of 10.6 microns for a CO 2 gas laser, a pulse mode at wavelengths of 2.7 or 3.8 microns for HF or DF gas lasers, respectively, and finally a pulse mode mid-infrared rare gas laser.
SUMMARY OF THE INVENTION
It is an important object of the invention to provide a transverse gas flow radio frequency discharge waveguide laser capable of operating as a continuous wave mode mid-infrared gas laser.
Another object of the invention is to operate the laser at a relatively high gas flow velocity to enhance efficient cooling of the laser medium and the electrodes, as well as increased replenishment rate of deterent gases, so that high laser output per unit gain length can be extracted.
Yet another object of the invention is to provide a hydrogen-fluoride or deuterium-fluoride laser as the gas laser.
BRIEF DESCRIPTION OF THE DRAWINGS
Various other objects, advantages and meritorious features of the invention will become more fully apparent from the specification, appended claims and accompanying drawing sheets.
The features of a specific embodiment of the invention are illustrated in the drawings, in which:
FIGS. 1a, 1b and 1c are schematic diagrams of the transverse gas flow mid-infrared continuous wave RF-pumped gas laser system;
FIG. 2 is a graph illustrating chemical laser output power vs. total velocity for the laser system of FIGS. 1a, 1b and 1c; and
FIG. 3 illustrates a compact recirculating gas DF laser package.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1a, 1b, 1c, 2 and 3 by the characters of reference, there is illustrated a laser system for carrying out the objects of the invention.
In a prior patent application, U.S. Ser. No. 470,409, noted supra, the transverse gas flow laser system, as illustrated in FIGS. 1a and 1b, is described in detail. The laser system consists of a solid metal body 1 having two ports 3, 5 for gas circulation connected to a gas recirculation pump 76. A metal screen is spatially offset from the RF excitation electrodes 9, 11 to provide uniform gas flow within the discharge region 13. The upper electrode 9 is set into a section of nonconducting material 12 providing insulation of the electrode from the metal body 1. The lower electrode 11 is attached to the laser body 15 to provide a common ground. The optics consist of a total reflector or mirror 21 and a partial reflector 23. The electrode faces are polished smooth to minimize diffractive and scattering losses. The optics are spatially offset from the bore. This sets to minimize the coupling while at the same time preventing discharge to the reflectors 21 and 23.
The electronic circuit is illustrated in FIG. 1c and includes a 50 ohms RF power source 130 which operates in a continuous wave mode. The off-the-shelf cw power source used herein is manufactured by Amplifier Research with a model number of 100LM9, and is referred to as an RF Amplifier. It has a frequency capability of 1 to 200 megahertz, a maximum power of 200 watts linear RF, a minimum gain of 53 db, and a flatness of plus or minus 1.5 db.
Energy from source 130 is transmitted through an aperture 132 to an RF circulator 134 having a 50 ohm lead 136 attached, and from there to a cw forward/reflecting power meter 138. The power meter 138 is used to monitor the forward and reflected waves from the laser cavity 133 through a matching network 140 and a RF switch 142. The matching network 140 matches the inductance of the cavity 133 to the source 130 in order to achieve efficient power coupling into the laser medium. Although absorbed power in the gas was measured, all efficiencies quoted hereafter are referenced to the RF power from the power source 130.
It will be appreciated that a much faster gas flow can be achieved by recirculating the laser gas. A design for such a recirculating gas laser is illustrated in FIG. 3. This design includes the electrodes 9, 11 of FIG. 1a, a chemical scrubber and heat exchanger 30, a gas recirculator 32, a gas supply bottle 34 and a chassis 36 having the RF power supply electronics. An increase in the gas replenishment rate will result in an order of magnitude improvement of laser power. A scrubber to eliminate the generated HF or DF molecules is also required along with a small replenishment supply of SF 6 and H 2 or D 2 .
Continuous wave (cw) oscillation can be obtained in the 2.7μ (micron) wavelength for hydrogen-fluoride (HF) and the 3.8μ (micron) wavelength for deuteriumfluoride (DF) laser systems of FIGS. 1a-c by utilizing the transverse flow (TF) hybrid waveguide laser configuration. This configuration was used previously to demonstrate efficient lasing for both 2.7μ HF and 3.8μ DF with pulsed excitation as already noted. The transverse flow configuration provides a high replenishment rate of the laser which is necessary for cw operation. The replenishment rate of a system is determined by the gas velocity and the distance the gas travels within the discharge region 13. A comparable replenishment rate in the waveguide configuration would therefore be difficult to obtain because of the small cross-section of the bore and large pressure drop across the discharge region 13. This high replenishment rate is necessary in order to allow the deterent HF or DF, which is generated during the chemical reaction, to be swept out of the gain regions. As an example, for an HF system, the laser gas consists of SF 6 , He and H 2 . Alternatively, for a DF system, the laser gas consists of SF 6 , He, and D 2 . For the DF system, the RF discharge disassociates the SF 6 to produce a fluoride atom which, in turn, reacts with D 2 to prodcue vibrationally excited DF molecules. When the excited molecule relaxes to its ground state, it emits a photon at a wavelength of 3.7-4.0μ (microns). The formulas for the above are as given infra:
SF.sub.6 +e goes to SF.sub.5 +F+e
F+D.sub.2 goes to DF(v)+D
DF(v) goes to DF(v-1)+hv(3.7-4.0μ)
The generated ground state molecules prevent the laser from oscillating, especially on the low J(v=1→0) transitions. By increasing the replenishment rate via increased gas velocity, the efficiency will increase, but will never reach pulsed mode efficiencies. The maximum expected electrical efficiency is 2%.
The 3.8μ DF laser was demonstrated using cw RF technology wherein a maximum output power of 0.25 watts was achieved. An input power of 85 watts, with approximately 45 watts being reflected back in the associated electronics shown in FIG. 1c, was used to characterize the laser. The laser gas ratio He:SF 6 :O 2 was 200:1:0.5 for varied flow rates of lasant wherein the laser has a 200 centimeter gain length and the discharge for cavity 133 is uniform throughout the length. The output power increased as the velocity or flow rate increased as shown in FIG. 2. This is due to the increased velocity and hence an increased replenishment rate. Operating pressure for the laser system was between 60 to 80 Torr, varying with increased flow rates. It will be appreciated that velocity is directly proportional to pressure in the laser system.
It is axiomatic that the lasant must be kept at a cool temperature for good efficiency 6. As the temperature increases, the population in the V 2 vibrational mode increases, and the laser efficiency decreases. Improved cooling of the laser gas is provided by flowing gas. Small decreases in efficiency can be retrieved by optimizing the lasant mixture to allow for higher powers.
It will be appreciated that the system as described can be utilized as a relatively small compact cw laser at the mid-IR wavelength.
While the above referenced embodiment of the invention has been described in considerable detail with respect to the system, it will be appreciated that other modifications and variations thereon may be made by those skilled in the art without departing from the true spirit and scope of the invention.
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An improved transverse gas flow RF pumped waveguide laser has been developed utilizing RF discharge waveguide technology in a mid-infrared laser. A potential application has been identified in a continuous wave gas laser. For the laser, the flowing gas provides efficient cooling so that high output power per unit gain length can be achieved.
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BACKGROUND
[0001] Test cases are typically comprised of program code. Over time a large test bed of many different programs is typically developed. When the software the test programs test changes, the test programs need to be refactored and updated. The high cost of maintaining the test programs hinders not only the development of new test cases but also the evolution of the libraries that the test cases use. Writing test cases in program code also makes it more difficult to outsource test work to other companies or vendors because the process of writing code needs to be reviewed and because it requires considerable skill.
SUMMARY
[0002] The test case is abstracted into a declarative form such as a re-useable script or file, etc. that expresses the intent of a task rather that defining how the test will be performed. Tools translate the declarative statements into a series of steps corresponding to code that implements the action indicated in the test. The schema for the tests can be dynamic. New forms of test cases can take advantage of existing and new actions so that the library of actions can be extended. Libraries are interchangeable. Test cases can be generated using a state machine. New test cases can be composed dynamically using a state machine to create new test cases.
[0003] Because the test is developed in a non-traditional programming language, the test developer is subjected to a discipline that puts constraints on his or her test making options, preventing him or her from creating invalid tests and providing a built-in feature that forces the test author to consider how the test will be performed as he or she writes the test case. At any given point only a finite set of available actions are available, preventing the test writer from inadvertently causing problems by creating incorrect tests.
[0004] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] In the drawings:
[0006] FIG. 1 a illustrates an example of a system 100 for using a declarative language to call APIs to perform software testing in accordance with aspects of the subject matter disclosed herein;
[0007] FIG. 1 b illustrates an example of how the layered architecture of system 100 can be shared among developer teams in accordance with aspects of the subject matter disclosed herein;
[0008] FIG. 2 a is an example of a test case in accordance with aspects of the subject matter disclosed herein;
[0009] FIG. 2 b is an example of an implementation of an action in accordance with aspects of the subject matter disclosed herein;
[0010] FIG. 2 c is another example of a test case in accordance with aspects of the subject matter disclosed herein;
[0011] FIG. 2 d is another example of an implementation of an action in accordance with aspects of the subject matter disclosed herein;
[0012] FIG. 2 e is a flow diagram of an example of a method 250 for using a declarative language to call APIs to perform software testing in accordance with aspects of the subject matter disclosed herein as described with respect to FIG. 1 ;
[0013] FIG. 3 is a block diagram illustrating an example of a computing environment in which aspects of the subject matter disclosed herein may be implemented; and
[0014] FIG. 4 is a block diagram of an example of an integrated development environment in accordance with aspects of the subject matter disclosed herein.
DETAILED DESCRIPTION
Overview
[0015] Typically, tests are written in code and are tightly coupled to implementation. Tests written in code are fragile and difficult to maintain. Implementation changes often render the tests inoperative. Porting tests to a different automation framework tends to be labor-intensive and costly. It is often difficult to know what scenarios an automated test case covers because it is hard to perform queries on test code written in a traditional programming language. Tests written in program code are hard to read and hard to write. Tooling support for writing tests is limited. For these reasons and others, testing is difficult to outsource.
[0016] The subject matter disclosed herein describes methods, systems and computer program products for a data-driven (instead of a code-driven) test framework in which tests are abstracted into actions that are specified in a declarative or domain specific language or script instead of coded in a traditional programming language. The test cases are independent of the underlying test automation framework and implementations of the software being tested. Tests express what to test and what is expected rather than how to test. A test engine can execute the test by interpreting the actions specified in the test. Interchangeable libraries can be developed for different implementations and/or different automation frameworks. The abstraction layer described herein can be layered on top of any automation framework including but not limited to MAUI, DTE Microsoft's Visual Studio® automation library and other automation frameworks.
[0017] Tests written as described herein are easy to write, run, debug, query, understand and maintain. Test authors are forced to factor tests in a clean, maintainable way that avoids duplication and promotes reuse. The layered architecture enables sharing of common layers across teams of developers. Changes in software implementations are easily managed by having interchangeable libraries. Tests written as described herein can be used to test at the user interface level, at the component level, at the application programming interface (API) level and so on.
Using a Declarative Language to Call APIs to Perform Software Testing
[0018] FIG. 1 a illustrates an example of a system 100 for using a domain specific language to call APIs to perform software testing in accordance with aspects of the subject matter disclosed herein. All or portions of system 100 may reside on one or more computers such as the computers described below with respect to FIG. 3 . All or portions of system 100 may reside on one or more software development computers such as the computers described below with respect to FIG. 4 . The system 100 or portions thereof may comprise a portion of an integrated development environment such as the ones described below and illustrated in FIG. 4 . Alternatively, system 100 or portions thereof may be provided as a stand-alone system or as a plug-in or add-in.
[0019] System 100 may include one or more computers such as computer 102 . The one or more computers may include one or more of: a processor (such as processor 142 ), a memory such as memory 144 , and one or more modules, such as module 140 , etc., for using a declarative language to call APIs to perform software testing. Other components well known in the arts may also be included but are not here shown. It will be appreciated that the module(s) for using a declarative language to call APIs to perform software testing can be loaded into memory 144 to cause one or more processors such as processor 142 to perform the actions attributed to the module(s) for using a declarative language to call APIs to perform software testing.
[0020] The system 100 for using a declarative language to call APIs to perform software testing may include one or more of the following: a test engine such as a script executer or scripting engine or an interpreter 106 , etc., one or more libraries of test actions such as library 108 , library 109 , etc., tests such as test 110 , etc. a schema 112 , a test query engine 114 and a test editor 116 . The system 100 may also include software being tested, as illustrated in FIG. 1 by software 120 , software 121 , etc. Software 120 can be, for example one implementation of software being tested and software 121 can be another implementation of software being tested. The test engine (e.g., interpreter 106 ) can execute the test 110 step by step by extracting an action from the test 110 , finding its implementation in a library 108 of test actions and executing the action. For example, interpreter 106 can execute test 110 by interpreting test 110 and executing a corresponding implementation for each step of the test at runtime. Implementation can be provided or changed without changing existing tests by loading a different library into interpreter 106 . A running instance of the software being tested (acting as a state machine 118 ) may also be included in system 100 . System 100 may comprise a portion of an interactive editing environment or REPL or an integrated development environment or IDE such as IDE 104 .
[0021] A test or test case such as test 110 can be an abstraction of a testing intent. The testing intent can be specified in a declarative form by declarative statements that are independent of implementations of the software and/or independent of a testing framework or testing automation framework. Tests such as test 110 , etc. can be written in a customized declarative language, a scripting language, or a domain specific language. Test 110 is not written in a traditional, general purpose programming language like C++ or C#. In test 110 , the intent of the test is expressed but how the test is conducted is not defined. That is, the test expresses what to test but not how to test it. Test intent is separated from implementation, so that implementation does not affect the test. This means that if implementation aspects of software change, the tests that test the software do not have to be changed. Implementation changes can be handled by changing the library of action implementations, for example, by loading a different library into the interpreter during testing.
[0022] For example, a first library of actions may test a first implementation of software using a test and a second library of actions may test a second implementation of software (such as a second version of the software, for example) using the same (unchanged) test. Similarly, a first library of actions may test a first automation framework for software testing using a test and a second library of actions may test a second automation framework for software testing using the same (unchanged) test. Because tests are not dependent on implementation, tests are reusable and are resilient to underlying test framework changes. Automation infrastructure can be modified or replaced without affecting the utility of the tests. Tests as described herein can be used to test software at the user interface level, at the component level, at the API level and for both test and production software environments. Tests can be created according to a methodology. For example an explicit API design can require actions to have recognizable signatures. A test case can comprise a sequence of actions. An action can be implemented as a call to an API using a method caller as described more fully below.
[0023] A test (e.g., test 110 ) can be associated with a schema such as schema 112 . A schema enables a test to be checked for correctness resulting in verifiable tests. For example, tests written in XML can be verified with an XML schema. Association with a schema can provide automatic correctness proving and can provide static type checking programming aids such as auto-completion, member lists and so on when editing and developing tests in a test editor such as test editor 116 . User input 134 (e.g., creating a test case) can be received by the editor 116 and can by checked for correctness as the user is developing the test case using the schema 112 . A schema 112 can be generated by a schema generation tool 113 that reflects over the libraries and generates a schema that includes all the valid actions and valid signatures for each valid action. That is, the schema can establish a finite set of valid actions and a finite set of valid signatures for each action in the finite set of valid actions during development of the test case. A schema defines a valid test file and can be used to provide interactive programmer aids like auto-completion and correctness checking when writing or editing test cases.
[0024] Because tests are written in a language that is machine-readable, rich tool support can be provided for test authoring. Examples of tools include editors, such as editor 116 in FIG. 1 , and others including but not limited to generators, test searchers, navigators and so on. An editor such as editor 116 may be provided for developing tests. Editor 116 may receive one or more schemas such as schema 112 to provide static type checking program aids such as auto-completion to the test author as he or she is writing or editing a test 110 . Editor 116 may also be able to provide verification of correctness of the test based on the schema or based on information derived from the schema.
[0025] Libraries such as library 108 , etc. include one or more action implementations. A library can be an extensible pool of atomic actions. Libraries, as described above, can be interchangeable. That is, an action implementation can be substituted by another action implementation so that the same test can execute on different implementation frameworks or on different implementations of software by loading a different library or set of libraries. More than one library can be loaded into the interpreter or script engine concurrently. If more than one library includes a specified action, an algorithm for selecting which action to execute can be provided (e.g., use action from the last library loaded, from the first library loaded, select an action at random, cycle through libraries, and so on). Each action within the library can be parameterized with data. The data description can form the signature of an action. Each action can provide the data prescribed by the signature of an action. An action implementation can be written in a general purpose programming language such as C#, C++ and so on. Duplication of code is more easily avoided by centralization of code in a library.
[0026] A state machine (e.g., a running instance of the software to be tested) such as state machine 118 may provide changes in state so that continuous testing can occur. A query engine such as query engine 114 can search all the tests for occurrences of a specified action, (e.g., find all tests that exercise (push) the calculator equals button). Because tests are written in a declarative form, untested portions of software under development can be more easily discovered. During test execution, one or more libraries can be loaded, an action in the library can be identified and dynamically loaded and the action can be executed. A script executing engine or interpreter such as interpreter 106 can receive a test, load it, load one or more libraries, identify the actions to be executed and execute the actions of the test in a sequential order. Interpreter 106 may dynamically load known actions from an action library such as library 108 . An example of a test 220 is illustrated in FIG. 2 a . Test 220 is written in XML but it will be appreciated that test 220 can be written in any declarative, domain specific or scripting language.
[0027] The layered architecture described above facilitates sharing common layers across teams of developers. FIG. 1 b illustrates an example of how layers can be shared. Product unit teams 150 can include developer teams such as a C# team 152 , a VB team 154 and an F# team 156 . Examples of product unit specific functionality 158 is represented by separate testhooks for the C# language service specific testhooks 160 , the VB language service specific testhooks 162 and the F# language service specific testhooks 164 . Common IDE functionality 168 can be shared by all the product teams (*.IDEWrapper 170 ). Common automation frameworks 172 may include frameworks such as TNugget 174 used by the C# team, while the DTE automation library 176 may be used by the VB team and the MAUI framework 180 with its adapter *.Maui 178 may be used by the F# team where all the teams are testing a product 182 such as an IDE 184 .
[0028] FIG. 2 a illustrates a fragment of a test case 200 beginning with a test node called TestScenario 202 . The test case TestScenario 202 is written in the declarative, domain specific, non-traditional programming language XML, although it will be appreciated that test case 200 could be written in any declarative, domain specific language, non-traditional programming language such as but not limited to Json, LISP, Python, custom text file format, or as a Microsoft Excel® spreadsheet. The node titled LaunchCalcProgram in the statement <LaunchCalcProgram/> 204 is an example of an action that expresses the intent of launching a program (such as calc.exe, for example) in a declarative way that is independent of any particular implementation. Elsewhere, in one or more libraries, code typically exists that actually launches the calculator program and interacts with the host operating system. The statement “<LaunchCalcProgram/> 204 is followed by several statements that indicate the intent of clicking on a calculator's two key: <ClickCalcButton ButtonName=”2″/> 206 , plus key <ClickCalcButton ButtonName=“+”> 208 , two key, <ClickCalcButton ButtonName=“2”/> 210 or equals key, <ClickCalcButton ButtonName=“=”/> 212 . ButtonName is a parameter (e.g., of type integer) that is being passed and refers to an attribute (name) of the button to click. Thus, instead of using custom code in the test case, the intent is indicated in a declarative way. The statement <VerifyCalcResult=“4”/> Line 213 expresses an expected result. It will be appreciated that even a test author with no programming language skills in a traditional general purpose programming language with no knowledge of automation libraries would be able to author such a test case. The action name and the parameters comprise the signature of the action. The schema associated with the declarative language can be used to provide auto-completion and other types of programming aids for the developer as he or she is writing the test case in a test editor.
[0029] As described above, a test engine such as an interpreter can load the test case (e.g., test case 200 ), can identify the actions to be executed and can identify any applicable parameters. For example, interpreter 106 of FIG. 1 can load test case 200 , identify the action ClickCalcButton with parameter ButtonName=“2” of statement ClickCalcButton ButtonName=“2”/> 206 . The interpreter can then dynamically load known actions from a library of actions such as library 108 of FIG. 1 which can contain the actual code to automate the test scenario. This can be done through a code reflection based mechanism to decouple the test case language from the automation code.
[0030] FIG. 2 b illustrates a portion of an example implementation of the action ClickCalcButton. For example, code in a traditional programming language such as C# may define a class name ClickCalcButton 214 of type Action 216 that can implement a particular interface or inherit from a particular base action so that when ClickCalcButton 214 is executed the custom code that performs the instructions to do the clicking of the calc button action in that particular implementation. At runtime the test engine can access all the properties of the elements in the test case. For example in the test scenario example described above, the code corresponding to the ClickCalcButton action would be executed four separate times. The first time the ClickCalcButton was invoked the property for ButtonName would have the value “2”, the second time it would have the value “+” and so on. A preprocessing step may load the test case file and find the corresponding code elements that correspond to the elements in the test case file. At runtime the code elements can be constructed in such a way that information from the test case file is passed to the code elements so that for example, the ClickCalcButton action has a property called ButtonName that refers to the key that was pressed. Every time the ClickCalcButton action is executed, the button name is set to the appropriate value.
[0031] FIG. 2 c illustrates another example of a test 220 that renames classes. The statement <AddFileByContext FileName=“RenameGenerics.cs” 222 adds the file RenameGenerics.cs to the IDE. The statement <OpenFileByContext Filename=“RenameGenerics.cs” 224 opens the file (e.g., triggered by doubleclicking the name, or by selecting an option from a menu). The statement <Rename StartLocation=“class1” OldName=“A” NewName=“ARenamed”/> 226 invokes the functionality to rename class A to class ARenamed. The statement <Find What=“ARenamed”/> 228 verifies that the rename operation was successful by finding the class ARenamed. In the statement <AddFileByContext FileName=“RenameGenerics.cs” 222 , FileName is a parameter having the value “RenameGenerics.cs”. In the statement <OpenFileByContext Filename=“RenameGenerics.cs” 224 FileName is a parameter having the value “RenameGenerics.cs”. In the statement <Rename StartLocation=“class1” OldName=“A” NewName=“ARenamed”/> 226 , StartLocation with the value “class1”, OldName with the value “A” and NewName with the value “ARenamed are parameters of the action Rename.
[0032] FIG. 2 d illustrates a sample action implementation 230 written in C#. In the sample action implementation 230 , action signature 232 is a declaration of the data that is needed by the action. In action implementation 230 , one string (for What is to be found) and three Booleans will be read from the test case. The implementation of the action 234 defines what is done with the data that is extracted from the test case. For each action call in the test case, the test engine initializes the action instance and automatically fills properties from the test case. For example for the statement <Find What=“ARenamed”/> 228 the content of the string What in line 236 of FIG. 2 d is set by reading line <Find What=“ARenamed”/> 228 from FIG. 2 c and setting What to “ARenamed”. Properties can be of primitive types such as Boolean (bool), string or integer (int), complex types such as .NET types or lists of any types. Mapping can be performed by an object deserializer. If a property (e.g., What in line 236 ) is marked with the Required property 242 and is not found in the test case, an exception can be thrown.
[0033] FIG. 2 e illustrates an example of a method 250 for using a domain specific language for calling APIs to test software in accordance with aspects of the subject matter disclosed herein. One or more of the acts described in method 250 are optional. At 252 an implementation for actions is written or received. At 254 a schema is created from the library of actions. At 256 a test case as described herein is written or received and can be validated using the schema. At 258 a test using the test case is run. A test engine can receive the test case, extract the first action, find the action in one or more libraries by matching the name of the action in the test case with a name of an action in the one or more libraries, instantiate the class implementing the action, create an instance of the class in memory, reading in the parameters for the instance of the class from the test case and calling the execute method on that class. Alternatively, instead of calling an execute method, a method caller can read in the action from the test case and can match the action name not only to an action class but also to any method on any class. Thus, if there are any public (callable) methods then the method caller can treat the parameters for the action as parameters for that method. Instead of calling the execute method the method caller can call whatever method was specified. This feature opens possibilities for generic scripting, API calling, testing, and creation of an XML-based DSL for calling APIs because APIs are typically methods on classes.
Example of a Suitable Computing Environment
[0034] In order to provide context for various aspects of the subject matter disclosed herein, FIG. 3 and the following discussion are intended to provide a brief general description of a suitable computing environment 510 in which various embodiments may be implemented. While the subject matter disclosed herein is described in the general context of computer-executable instructions, such as program modules, executed by one or more computers or other computing devices, those skilled in the art will recognize that portions of the subject matter disclosed herein can also be implemented in combination with other program modules and/or a combination of hardware and software. Generally, program modules include routines, programs, objects, physical artifacts, data structures, etc. that perform particular tasks or implement particular data types. Typically, the functionality of the program modules may be combined or distributed as desired in various embodiments. The computing environment 510 is only one example of a suitable operating environment and is not intended to limit the scope of use or functionality of the subject matter disclosed herein.
[0035] With reference to FIG. 3 , a computing device for efficient resumption of co-routines on a linear stack in the form of a computer 512 is described. Computer 512 may include a processing unit 514 , a system memory 516 , and a system bus 518 . The processing unit 514 can be any of various available processors. Dual microprocessors and other multiprocessor architectures also can be employed as the processing unit 514 . The system memory 516 may include volatile memory 520 and nonvolatile memory 522 . Nonvolatile memory 522 can include read only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM) or flash memory. Volatile memory 520 may include random access memory (RAM) which may act as external cache memory. The system bus 518 couples system physical artifacts including the system memory 516 to the processing unit 514 . The system bus 518 can be any of several types including a memory bus, memory controller, peripheral bus, external bus, or local bus and may use any variety of available bus architectures.
[0036] Computer 512 typically includes a variety of computer readable media such as volatile and nonvolatile media, removable and non-removable media. Computer storage media may be implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CDROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other transitory or non-transitory medium which can be used to store the desired information and which can be accessed by computer 512 .
[0037] It will be appreciated that FIG. 3 describes software that can act as an intermediary between users and computer resources. This software may include an operating system 528 which can be stored on disk storage 524 , and which can control and allocate resources of the computer system 512 . Disk storage 524 may be a hard disk drive connected to the system bus 518 through a non-removable memory interface such as interface 526 . System applications 530 take advantage of the management of resources by operating system 528 through program modules 532 and program data 534 stored either in system memory 516 or on disk storage 524 . It will be appreciated that computers can be implemented with various operating systems or combinations of operating systems.
[0038] A user can enter commands or information into the computer 512 through an input device(s) 536 . Input devices 536 include but are not limited to a pointing device such as a mouse, trackball, stylus, touch pad, keyboard, microphone, and the like. These and other input devices connect to the processing unit 514 through the system bus 518 via interface port(s) 538 . An interface port(s) 538 may represent a serial port, parallel port, universal serial bus (USB) and the like. Output devices(s) 540 may use the same type of ports as do the input devices. Output adapter 542 is provided to illustrate that there are some output devices 540 like monitors, speakers and printers that require particular adapters. Output adapters 542 include but are not limited to video and sound cards that provide a connection between the output device 540 and the system bus 518 . Other devices and/or systems or devices such as remote computer(s) 544 may provide both input and output capabilities.
[0039] Computer 512 can operate in a networked environment using logical connections to one or more remote computers, such as a remote computer(s) 544 . The remote computer 544 can be a personal computer, a server, a router, a network PC, a peer device or other common network node, and typically includes many or all of the elements described above relative to the computer 512 , although only a memory storage device 546 has been illustrated in FIG. 4 . Remote computer(s) 544 can be logically connected via communication connection 550 . Network interface 548 encompasses communication networks such as local area networks (LANs) and wide area networks (WANs) but may also include other networks. Communication connection(s) 550 refers to the hardware/software employed to connect the network interface 548 to the bus 518 . Connection 550 may be internal to or external to computer 512 and include internal and external technologies such as modems (telephone, cable, DSL and wireless) and ISDN adapters, Ethernet cards and so on.
[0040] It will be appreciated that the network connections shown are examples only and other means of establishing a communications link between the computers may be used. One of ordinary skill in the art can appreciate that a computer 512 or other client device can be deployed as part of a computer network. In this regard, the subject matter disclosed herein may pertain to any computer system having any number of memory or storage units, and any number of applications and processes occurring across any number of storage units or volumes. Aspects of the subject matter disclosed herein may apply to an environment with server computers and client computers deployed in a network environment, having remote or local storage. Aspects of the subject matter disclosed herein may also apply to a standalone computing device, having programming language functionality, interpretation and execution capabilities.
[0041] FIG. 4 illustrates an integrated development environment (IDE) 600 and Common Language Runtime Environment 602 . An IDE 600 may allow a user (e.g., developer, programmer, designer, coder, etc.) to design, code, compile, test, run, edit, debug or build a program, set of programs, web sites, web applications, and web services in a computer system. Software programs can include source code (component 610 ), created in one or more source code languages (e.g., Visual Basic, Visual J#, C++, C#, J#, Java Script, APL, COBOL, Pascal, Eiffel, Haskell, ML, Oberon, Perl, Python, Scheme, Smalltalk and the like). The IDE 600 may provide a native code development environment or may provide a managed code development that runs on a virtual machine or may provide a combination thereof. The IDE 600 may provide a managed code development environment using the .NET framework. An intermediate language component 650 may be created from the source code component 610 and the native code component 611 using a language specific source compiler 620 and the native code component 611 (e.g., machine executable instructions) is created from the intermediate language component 650 using the intermediate language compiler 660 (e.g. just-in-time (JIT) compiler), when the application is executed. That is, when an IL application is executed, it is compiled while being executed into the appropriate machine language for the platform it is being executed on, thereby making code portable across several platforms. Alternatively, in other embodiments, programs may be compiled to native code machine language (not shown) appropriate for its intended platform.
[0042] A user can create and/or edit the source code component according to known software programming techniques and the specific logical and syntactical rules associated with a particular source language via a user interface 640 and a source code editor 651 in the IDE 600 . Thereafter, the source code component 610 can be compiled via a source compiler 620 , whereby an intermediate language representation of the program may be created, such as assembly 630 . The assembly 630 may comprise the intermediate language component 650 and metadata 642 . Application designs may be able to be validated before deployment.
[0043] The various techniques described herein may be implemented in connection with hardware or software or, where appropriate, with a combination of both. Thus, the methods and apparatus described herein, or certain aspects or portions thereof, may take the form of program code (i.e., instructions) embodied in tangible media, such as floppy diskettes, CD-ROMs, hard drives, or any other machine-readable storage medium, wherein, when the program code is loaded into and executed by a machine, such as a computer, the machine becomes an apparatus for practicing aspects of the subject matter disclosed herein. In the case of program code execution on programmable computers, the computing device will generally include a processor, a storage medium readable by the processor (including volatile and non-volatile memory and/or storage elements), at least one input device, and at least one output device. One or more programs that may utilize the creation and/or implementation of domain-specific programming models aspects, e.g., through the use of a data processing API or the like, may be implemented in a high level procedural or object oriented programming language to communicate with a computer system. However, the program(s) can be implemented in assembly or machine language, if desired. In any case, the language may be a compiled or interpreted language, and combined with hardware implementations.
[0044] While the subject matter disclosed herein has been described in connection with the figures, it is to be understood that modifications may be made to perform the same functions in different ways.
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A test case is abstracted into a re-useable script or other declarative form that expresses the intent of a task rather that defining how the test will be performed. Tools translate the declarative test into a series of steps corresponding to code that implements the action indicated in the declarative test. The schema for the tests can be dynamic. New forms of test cases can take advantage of new actions so that the library of actions can be extended. Libraries are interchangeable. Test cases can be generated using a state machine. New test cases can be composed dynamically using a state machine to create new test cases.
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FIELD OF THE INVENTION
There is a need for substantial amounts of water for hydraulic fracturing operations. A potential exists in many areas to access and use a non-potable water aquifer formation for this purpose. An example would be the Debolt aquifer or the like, which was tested successfully.
BACKGROUND OF THE INVENTION
Nexen Inc. (“Nexen”), the assignee, has natural gas shale deposits in northeast British Columbia. Efficient and cost effective production of the natural gas shale deposits in the area is dependent upon the availability of water for fracturing operations. The expected daily gas production in the area will require an estimated annual volume of at least 1.3 MM m 3 of water with such water generally coming from natural above ground sources and/or pre-treated underground sources. In order to maximize the value of this natural gas reserve, a reliable supply of sufficient quantities of water for fracturing stimulation programs is necessary to enable the delivery of the projected production levels.
One of the opportunities for achieving value is to streamline the process for providing water for frac programs through the innovative use of non-potable water.
It is therefore a primary object of this invention to provide a method and process for fracturing a hydrocarbon reservoir utilizing water from an aquifer adjacent said reservoir. The suitable aquifer could also be nearby and be either shallower or deeper than the said reservoir.
It is another object of the invention to use the method and process when fracturing a natural gas reserve.
It is yet another object of the invention to avoid treating the aquifer water prior to using it for hydrocarbon fracturing.
It is a further object of the invention to use the Debolt aquifer as a source of water for the fracturing of a natural gas reserve.
It is another object of the invention to provide said fracturing pump with construction materials in alignment with the well known recommendations published for material performance criteria from for example NACE, ASTME or ANSI trim packaging or the like in view of the corrosive nature of the fluids being pumped).
Further and other objects of the invention will be apparent to one skilled in the art when considering the following summary of the invention and the more detailed description of the preferred embodiments described and illustrated herein along with the appended claims.
SUMMARY OF THE INVENTION
The Debolt subsurface formation or zone is an aquifer whose water contains approximately 22,000 ppm of total dissolved solids (“TDS”) and a small amount of hydrogen sulphide—H 2 S. The scope and volume of the Debolt formation is still being investigated, but it has the potential to be extensive. This aquifer has high permeability and porosity. A Debolt well at b-H18-1/94-O-8 was tested in May, 2010, with a 10.25″ 900 HP downhole electrical submersible pump (“ESP”). The well showed a Productivity Index of 107 m3/d per 1 kPa drawdown, indicating that the reservoir will provide a high enough rate of flow to support the volume and rate requirements needed to support well fracturing operations.
Debolt formation water contains sour gas in solution. When depressurized to atmospheric conditions, the Debolt water flashed off sour gas at a gas water ratio of 1.35 standard m 3 of gas to 1 m 3 of water. The flashed gas contained 0.5% H 2 S, 42% CO 2 and 57% CH 4 (methane). These gases are the same gases present in shale gas production being performed, which is normally in the range of 0.0005% H 2 S, 9% CO 2 , and 91% CH 4 (methane), and the use of raw Debolt water would have a negligible impact on the current percentage of shale gas components.
The challenge is how to use sour water, for example Debolt water, for fracing in a cost effective manner since current water fracturing equipment does not comply with the well known recommendations published for material performance criteria from for example NACE, ASTME or ANSI standards for trim packaging or the like. Current water frac contractors are reluctant to use Debolt water for fracturing operations. In part because current equipment is not NACE complian. But the primary reason relates to safety concerns with respect to H 2 S content of the Debolt water.
There are two different ways of using Debolt formation water for fracturing operations. The first is to construct and operate a water treatment plant to remove the H 2 S from Debolt water. This approach has been taken by other industry participants who have constructed an H 2 S stripping plant to remove the H 2 S from Debolt water. A recent paper published by Canadian Society for Unconventional Resources entitled “Horn River Frac Water: Past, Present, Future” discusses the technical and operational aspects of the Debolt Water Treatment Plant constructed and operated for the foregoing purposes. This paper states that a very expensive treatment plant is required to remove the H 2 S and other solution gases from the Debolt water.
The second approach is to maintain the aquifer water at a pressure above its saturation pressure (also known as the “Bubble Point Pressure” or “BPP”) on a continuous basis while being produced to surface and transported in pipelines to enable it to be used for fracturing. Tests conducted on the Debolt water properties indicates that as long as the Debolt water is maintained at a pressure high enough to keep the solution gas entrained in the water, the water is stable with no precipitates, and remains crystal clear in colour. Further the water is in the least corrosive state. These findings reveal that the Debolt aquifer fluid can be used in its natural state requiring no treatment. This is the basis of the proprietary Pressurized-Frac-on-Demand (“PFOD”) process.
The primary aspect of this invention is therefore to provide a method or process of fracturing a hydrocarbon deposit on demand comprising the steps of:
using as a source of water an underground aquifer which contains water which is stable and clear in the aquifer but which may include undesirable constituents that are in solution when subjected to surface conditions such as hydrogen sulfide and other constituents,
utilizing the water from the aquifer as a source of water to be used in a hydrocarbon fracturing process and to pump the water under pressure at a predetermined rate for the aquifer water and above the bubble point pressure (BPP) for the water contained in a particular aquifer to keep the water stable. We have found that the water becomes unstable when the pressure is reduced and gas is allowed to evolve out of the water. This depressuring and gas removal initiates a chemical reaction with the dissolved solids in the water to cause precipitates to form. To prevent these chemical reactions from occurring and causing the undesirable constituents of said water from falling out of solution,
maintaining said water pressure at a minimum required for each aquifer at all times during the fracturing process,
drilling a source well into the aquifer,
drilling a disposal well to the aquifer,
providing a pump capable of maintaining the required pressure needed to prevent the constituents of the aquifer water from coming out of solution only by maintaining the minimum pressure,
establishing a closed loop with a manifold, or a manifold and pumps, to keep the aquifer water circulating at all times until the fracturing operation begins when water will be supplied from that manifold,
providing the fracturing operation with water from the manifold so as to fracture a hydrocarbon reserve,
wherein in using water from an aquifer in the fracturing process and by maintaining said water under pressure at a minimum at all times, said water remains stable and the undesirable constituents remain in solution and the water remains clear thereby avoiding the necessity of treating the water from the aquifer prior to using it in a fracturing processes.
According to another aspect of the invention there is provided a method or process of high-pressure fracturing of a hydrocarbon deposit, for example a shale gas deposit on demand comprising the steps of using as a source of water from an underground aquifer such as the Debolt aquifer which contains sour water including H 2 S and other constituents,
utilizing the sour water from the aquifer as the water source to be used preferably on at least the clean side of a gas fracturing process and to pump said sour water under pressure at a minimum of for example 2310 kPa for Debolt water at approximately 38 degrees Celsius (which varies with the actual temperature of source water for each aquifer, and any surface cooling which may occur to such water) and above the BPP for the sour water contained in a particular aquifer to prevent H 2 S and other constituents of said sour water from falling out of solution,
maintaining said sour water pressure at a minimum required for each aquifer, for example for Debolt of 2310 kPa at all times during the fracturing process,
drilling a source well into the aquifer,
drilling a disposal well into the aquifer,
providing a pump capable of maintaining the required pressure needed to prevent the constituents of the sour water from coming out of solution only by maintaining the minimum pressure required which, for example, for Debolt water is 2310 kPa at 38 degrees Celsius, establishing a closed loop with a manifold to keep the sour water circulating at all times until the well fracturing operation begins when water will be supplied from that manifold, or a manifold and pumps,
providing the clean side of a well fracturing operation with sour water from the manifold so as to fracture a well reserve (normally an oil or gas zone reserve), wherein in using sour water from an aquifer such as Debolt for the gas fracturing process and maintaining said sour water under pressure at a minimum, as an example for Debolt water being at 2310 kPa and 38 degrees Celsius, said water remains stable and the constituents remain in solution and the water remains clear thereby avoiding the necessity of stripping out the hydrogen sulfide and other constituents as is required by other well fracturing processes.
In one embodiment of the invention said water source and method or process is utilized along with sand on the dirty side of the well fracturing operation with the addition of a high-pressure blender since the sour water must be maintained above its BPP, for example 2310 kPa for Debolt water at 38 degrees Celsius at all times thereby avoiding the constituents including the H 2 S from falling out of solution.
In a further embodiment of the method or process the necessary number of pumps and source wells and disposal water wells are provided with the method or process to enable a high-pressure fracturing operation on demand for a target number of fracs (which depends on the particular well design chosen for a reservoir stimulation or other purpose) for each well, or number of wells, stimulated as part of a program.
Preferably in the method or the process said water from the source aquifer is at an elevated temperature, for example for Debolt water a temperature under normal circumstances has been 38 degrees Celsius, which therefore requires no additional heating, or insulated piping, and which may be used as a source of sour water for the pressurized fracturing on demand process even during the colder winter months experienced in, for example, Western Canada or similar areas and which can contribute considerable cost savings when compared to utilizing surface water.
In yet another embodiment the method or process utilizes sour water from the Debolt aquifer and continuously circulates said water at a pressure above the BPP from the source well to the disposal well in an underground pipeline system accomplished by a back pressure control valve located downstream of the well to be fractured near the Debolt water circulation line and yet upstream of the disposal wells wherein when water is required for frac operations, water will be withdrawn from a manifold strategically located on this circulation line thereby feeding Debolt water to the frac operation under pressure, which is above the Debolt BPP.
According to yet another embodiment of the method or process the Debolt water is maintained at a pressure above its saturation pressure and is continuously used for fracing so that as long as the Debolt water is maintained at a high enough pressure to keep the solution gas entrained in the water, then the water remains stable, with no precipitates and is in the least corrosive state thus requiring that all frac operations (at least on the clean side) be conducted at pressures above the Debolt water BPP which is the basis for a successful PFOD process.
In yet another embodiment the method or process further comprises a NACE trim, preferably a High Pressure Horizontal Pumping System (“HPHPS”) frac pump capable of providing a discharge pressure of about 69 MPa. The pump construction uses materials in alignment with the recommendations published by the National Association of Corrosion Engineers (“NACE”) trim packaging in view of the corrosive nature of the fluids being pumped). Alternatively, materials may be selected from material performance criteria for a HPHPS frac pump or equivalent published by for example ASTME, ANSI or the like.
In order to carry out the process of this invention, a multistage centrifugal pump is built capable of delivering a discharge pressure or differential pressure between pump internal and external pressures to over 10,000 psi. A pressure sleeve or pump housing is designed to be the primary pressure containment. The sealing interface between the pump base and pump head is a metal on metal type achieved by using specialized thread. The diffusers are designed with openings to allow rapid pressure equalization across the diffuser outside edge to avoid failure from high differential pressure which could cause diffuser failure. A seal is used on the outside of the diffusers to prevent pressure communication, and fluid flow, between the outside of the individual diffusers enclosed within the housing. The pump connections to pump intake and discharge are upgraded to ring or gasket style sealing.
The present invention also relates to a multistage centrifugal pump design, which has the diffusers, impellors, and a shaft, inserted within a high pressure housing or barrel, wherein this assembly is fully enclosed within the housing, and the housing is of sufficient strength to be suitable for safe pressure containment of the fluids being pumped. This aspect of the invention describes the technical details used to reconfigure the known multistage centrifugal pump design to enable increase of the discharge pressure capabilities higher than the 6,000 psig of current designs. The design modifications discussed herein have been successfully tested at 10,000 psig discharge pressure. The 10,000 psig pressure capability provides a pressure suitable for fracturing formations penetrated by wellbores.
This style of pump unit is well suited to the hydrocarbon fracturing industry to be used to pump fluids at sufficient pressures, to stimulate oil and gas reservoirs.
The invention is a housing type of centrifugal pump, which is designed for operating at speeds of 30 to 90 hz, (1800 to 5400 rpm), with discharge pressures that may be 10,000 psig, and with a suction pressure that may be 15-600 psig. Fora 10,000 psig discharge pressure capability, such as this multistage centrifugal pump design enclosed within a housing, this is a more economical cost effective option as compared to prior structures such as a split casing multistage centrifugal pump.
Preferably said pump is utilizing pressure sleeve ( 21 ) on top of diffuser ( 22 ) wall for improved wall strength by compression fit between sleeve ( 21 ) and outside diameter of diffuser ( 22 ) wall.
Also preferably said pump is utilizing equalizations hole ( 23 ) in diffuser wall, resulting in zero deferential pressure across diffuser wall and also allows for rapid depressurizing.
Preferably to prevent stages from collapsing due to pressure transfer from one pump stage to another o-ring ( 31 ) style sealing is utilized between each diffuser ( 34 ) and housing ( 33 ).
In one embodiment sealing between pump housing ( 16 ) and both pump base ( 12 ) and pump head ( 19 ) is by specialized threads providing metal on metal sealing, eliminating all elastomeric and non-elastomeric seals through the use of proven metal-to metal thread sealing technology such as Base/Head Pin-Housing Connection).
The multistage centrifugal pump is designed for injecting fluids to a wellbore for purpose of fracturing this well.
According to that aspect of the invention there is provided a multiple stage centrifugal pump for fracturing hydrocarbon deposits capable to deliver discharge pressure or differential pressure between the pump internal and external pressure to be over 10,000 psi and including a pressure sleeve or pump housing designed for the primary pressure containment, sealing between the pump base and pump head is metal on metal type achieved by using specialized thread, diffusers are included designed with openings to allow rapid pressure equalization across the diffuser outside edge to avoid failure from high differential pressure which could cause diffuser failure, a seal is used on the outside of the diffusers to prevent pressure communication, and fluid flow, between the outside of the individual diffusers enclosed within the housing and the pump connections to pump intake and discharge are upgraded to ring or gasket style sealing.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a PFOD Flow Schematic.
FIG. 2 is a PFOD Elevation View.
FIG. 3 is a drawing of a high pressure multistage centrifugal pump assembly illustrating and describing all key components used within the pump assembly.
FIG. 4 is a cross section drawing of the high pressure multistage centrifugal pump assembly describing the components used within assembly.
FIG. 5 is a cross sectional illustration showing a number of impellor and diffuser stages in the high pressure multistage centrifugal pump housing.
FIG. 6 is a cross sectional illustration of diffuser, for the high pressure multistage centrifugal pump assembly and diffuser details showing compression sleeve ( 21 ) on top of diffuser ( 22 ).
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Over the past two years, Nexen has been working on the PFOD process as outlined below, using Debolt water above its BPP for fracing thus eliminating the need for an expensive H 2 S removal process.
In order to guarantee a reliable source of water for its fracturing operations, it was necessary to identify ways to utilize the Debolt water as part of the frac water source. One of the options reviewed was to use Debolt water for only the clean side of the frac program.
In light of its requirements, Nexen designed and built a small flow HPHPS frac pump for testing. In June 2010, a 0.25 m 3 /min NACE trim HPHPS test frac pump capable of providing a discharge pressure of 69 MPa was tested on the b-18-1 pad in northeast British Columbia. Technicians were onsite to operate the Debolt water source well (“WSW”) ESP and the HPHPS test frac pump. Three chokes consisting of two bean types and one variable choke were piped up in series to provide the back pressure to test the HPHPS frac pump at fracturing pressure.
In the initial tests, the HPHPS test frac pump used freshwater from a tank truck. All the pump control parameters were set. In subsequent tests, Debolt water was used and fed by the Debolt WSW at b-H18-I/94-O-8 by ESP to the suction of the HPHPS test frac pump. The discharge from the test frac pump flowed through three chokes at various back pressures. The Debolt water then exited the chokes and flowed into a disposal water pipeline to the water disposal well (“WDW”) at b-16-I. The back pressure was progressively increased at 7000 kPa intervals and ran at that discharge pressure for approximately 30 to 60 minutes. When pump operations remained steady, the choke was adjusted to increase the discharge pressure of the pump.
The HPHPS frac test pump was successfully tested on July 7 and 8, 2010. It operated at a discharge pressure of 71 MPa. The pump was run using Debolt water for approximately 6 hours at 62 MPa to simulate a complete fracturing operation.
It is understood that for other aquifers will have different physical parameters. For example pump specifications will reflect different Bubble Point Pressures for alternative water sources. For the Debolt water source, the BPP of the aquifer water was 2310 kPag at 38 degrees Celsius.
In August 2010 during the completion of the 8 wells at pad b-18-1, the HPHPS test frac pump was integrated into six fracturing operation. Three of the 6 fracs ran using freshwater and three ran using Debolt water. The HPHPS test frac pump ran well for all 6 fracs and there were no operational or safety issues encountered.
Only one source water well and one disposal well are required for the initial testing of the PFOD system, and additional wells will provide increased capacity and backup to ensure minimum flow rate and injection capacities are available as required for the system to operate reliably with maximum system availability and use. Nexen is planning to drill and complete additional Debolt formation WSWs and additional Debolt WDW in the future as required to optimize the Debolt water system to support fracturing operations. Together with the existing b-H18-I Debolt WSW and the existing Debolt WDW b-16-I, these 2 initial wells plus any additional wells will form the basis of the PFOD water circulation system identified for such well fracturing program.
Nexen will continue to further evaluate the need to source and test a 1.25 m3/min full size 3000 kPa suction pressure for a trim plunger frac pump for the dirty side based on the well known recommendations published for material performance criteria from for example, NACE, ASTME or ANSI trim packaging or the like. This also includes the evaluation of the need for a pressurized blender, or another method for utilizing Debolt water for the dirty side.
Based on the Debolt water well tests conducted in June 2010, a feasibility study of the PFOD process, and initial field testing of a prototype NACE trim HPHPS frac pump in July and August of 2010, it was concluded:
It is technically and economically feasible to use Debolt water in its untreated state for fracturing operations. It is possible using the PFOD process to maintain pressures above 2310 kPa (BPP for Debolt water) thus keeping gases including H 2 S contained in solution. No compatibility issues have arisen using Debolt water for fracturing or injection into shale. A HPHPS NACE trim frac pump using Debolt water can be constructed and used on the clean side of fracturing operations. No operational or safety issues were identified during the testing and ultimate use in the field of the HPHPS frac pump. Freshwater may not be readily available for operations. Water from Debolt using PFOD process is readily available availability is not subject to spring and summer rainfall or suspension of licenses due to drought. For example, in August, 2010, government regulators in British Columbia suspended freshwater withdrawal licenses for hydrocarbon fracturing operations in the Montney area due to a drought in the Peace River watershed. There is experience in the pump industry in building a high suction pressure plunger style pump, with a NACE trim fluid end. There is no experience in the frac pump industry in building a high suction pressure (over 330 prig (2300 kpag)) plunger style frac pump, with a NACE trim fluid end, capable of pumping American Petroleum Institute (“API”) quality frac sand for the dirty side fracing. There is no apparent technical limitation or constraint to prevent the engineering and fabrication of a pressure blender to use Debolt water under pressure.
The PFOD Process
The PFOD process maintains Debolt water at a pressure above its BPP at all times in order to prevent gases (including H 2 S, CO 2 and CH 4 ) from coming out of solution. Based on Debolt well formation water and Pressure-Volume-Temperature (“PVT”) tests, the Debolt water BPP is 2310 kPa (335 Psi) at 38 degrees Celsius. When the Debolt water at 38 degrees Celsius was de-pressurized to atmospheric pressure, approximately 1.35 m 3 gas was released per m 3 of water. The flashed gas contained 0.5% H 2 S, 42% CO 2 and 57% CH 4 (methane). These are the same gases present in certain shale gas operations (normally 0.0005% H 2 S, 9% CO 2 , and 91% CH 4 (methane). The use of raw Debolt water would have negligible impact on the current percentage of shale gas components content.
For the typical PFOD system, a total of 3 Debolt WSWs and 2 Debolt WDWs will be required. These WSWs and WDWs will be centrally located for two to three identified well pads selected for development. Debolt water will be continuously circulated at a pressure above the BPP from the WSWs to the WDWs in an underground pipeline system. This will be accomplished by a back pressure control valve located downstream of the well to be fractured near the Debolt water circulation line and yet upstream of the disposal wells wherein when water is required for frac operations, water will be withdrawn from a manifold strategically located on this circulation line thereby feeding Debolt water to the frac operation under pressure, which is above the Debolt BPP. The two figures show a PFOD flow schematic and a subsurface elevation view. These figures demonstrate how the PFOD pipeline system would work.
The advantages of a PFOD process are numerous and include the following:
Fracturing operations can to be conducted on a continuous basis year round. Debolt water is typically at 38 degrees Celsius. This allows for the use of Debolt water in the winter months without requirement for heating or the other infrastructure often required for winter frac operations including insulated pipelines for water circulation. Furthermore, service contractors for fracturing operations tend to be more available during non-peak winter months. Year round fracing capability will allow for production flexibility relative to commodity demand and pricing. The PFOD process eliminates the intensive capital and operation costs associated with building, operating and maintaining water treatment facilities. The PFOD process also reduces the need for secondary facilities that are required as development of fracturing operations occurs at greater distances from the water treatment and H 2 S removal plants. The PFOD process eliminates the need for above ground treated water storage tanks or large holding ponds that would ordinarily be required to heat the water for an above ground treatment process. The Debolt aquifer therefore acts as a natural storage tank with no surface facilities, heating or maintenance required. The Debolt aquifer could also be used as the main storage location of excess fresh water to be used later during a fracturing operations.
PFOD Pump Details
FIG. 3 illustrates a High Pressure multistage centrifugal pump assembly describing all components used in a preferred embodiment as follows:
15 pump support—skid frame. 42 pump driver—electric motor. 43 thrust chamber to support shaft load from pump. 44 pump intake section example. 45 Shows a low pressure multistage centrifugal pump housings containing the diffusers, impellors and shaft. Two pump sections are shown. Maximum design was to 6,000 psi discharge pressure. 46 Shows the high pressure multistage centrifugal pump housing containing the diffusers, impellors and shaft. This is the inventive aspect that takes the pressure capability from 6,000 psig up to 10,000 psig discharge pressure. 47 High pressure discharge head for 10,000 psig. This is the invention aspect that takes the pressure capability from 6,000 psig up to 10,000 psig discharge pressure.
FIG. 4 is a cross section drawing of High Pressure multistage centrifugal pump assembly of the invention describing all components used within assembly including pump base ( 12 ) and pump head ( 19 ) threaded into pump housing ( 16 ). Pump stage is an assembly of impeller ( 13 ) and diffuser ( 14 ). The impellers ( 13 ) are install on pump shaft ( 15 ) and are the rotating part of the pump. The diffusers ( 14 ) are fixed in the pump assembly by being compressed by compression bearing ( 18 ) in the pump housing ( 16 ) and against pump base ( 12 ).
FIG. 5 is a cross section drawing showing a number of impellor and diffuser stages in the High Pressure multistage centrifugal pump housing ( 16 ). This invention includes the equalization hole ( 23 ) for rapid depressurizing, and the support sleeve ( 21 ) completely around the diffuser, which has grooves ( 25 ) to contain the O-Ring ( 31 ) to prevent pressure communication, and fluid flow, between the outside of the individual diffusers enclosed within the housing. This high pressure housing ( 33 ) is designed to safely contain pressures up to 10,000 psig.
FIG. 6 is a cross section drawing of the diffuser, for the High Pressure multistage centrifugal pump assembly and diffuser details showing compression sleeve ( 21 ) on top of diffuser ( 22 ). This invention includes the equalization hole ( 23 ) for rapid depressurizing, and the O-Ring ( 31 ) to prevent pressure communication, and fluid flow, between the outside of the individual diffusers enclosed within the housing
CONCLUSIONS
Any fracturing operation requires large volumes of water. The PFOD process provides an alternative to use of fresh or treated subsurface water. The Debolt formation in northeast British Columbia has proven to contain non-potable water at volumes necessary for fracturing operations. The PFOD process eliminates water treatment by maintaining gases and particulates in solution thus allowing for use of natural untreated sour aquifer water for example as found in the Debolt aquifer or the like. This is accomplished by maintaining water pressure above the BPP eliminating costly water treatment and secondary facilities, replacing the use of freshwater by non-potable subsurface sour water, and decreasing the environmental footprint of fracturing operation.
As many changes therefore may be made to the preferred embodiment of the invention without departing from the scope thereof. It is considered that all matter contained herein be considered illustrative of the invention and not in a limiting sense.
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A method or process for hydraulically fracturing an underground hydrocarbon deposit includes using as a source of water an underground aquifer which contains water which is stable and clear in the aquifer but which may include undesirable chemical compounds as soluble components that are not in solution when subjected to reduced pressure at atmospheric conditions. Water from the aquifer is used as a source of water for the hydrocarbon fracturing process. The water is pumped at a pressure above its bubble point pressure A source well and a disposal well are drilled into the aquifer. A pump capable of maintaining the water above its bubble point pressure is provided, and a closed loop is established with a manifold, or a manifold and pumps, to keep the aquifer water circulating at a pressure above its bubble point pressure. The hydrocarbon reserve is fractured using the water.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a device for pressing a pressure shoe against a backing surface.
2. Background Description
A pressure shoe of this type can, in particular, be part of a shoe press unit, in particular of a shoe roll, and serve to press a flexible belt or flexible press cover for forming a press nip which is extended in the web running direction against a backing surface which is formed, for example, by a backing roll. A corresponding shoe press unit can be provided, for example, for manufacturing and/or treating a fibrous web, in particular a paper or paperboard web. Here, the fibrous web can be guided through the relevant press nip together with at least one felt or fabric.
Up to now, the pressure shoe was pressed on either by an oil pressure bed or separate pressing pistons. However, an oil pressure bed causes problems, in particular, with regard to sealing. The use of separate pressing pistons is associated with the disadvantage of a deviation in the transverse pressure profile which is caused by the individual pistons.
SUMMARY OF THE INVENTION
The invention is based on the aim of providing an improved pressing device of the type which is mentioned in the introduction, in which the abovementioned problems are eliminated. Here, in particular, a relatively uniform pressure distribution in the machine running direction and in the transverse direction is to be made possible, in order to achieve a pressure profile which is as planar as possible. The occurrence of reaction forces in the machine running direction and transverse direction is to be reduced to a minimum.
According to the invention, this aim is achieved by the fact that the device comprises at least one pressure element which is supported on a supporting body, is flexible at least in regions and has at least one hollow space which can be acted on with pressure fluid, in order to produce a predefinable pressing force via a corresponding pressure element volume. Here, the pressure element is preferably configured to be leakfree.
On account of this embodiment, a relatively uniform pressure distribution is possible in the machine running direction and transverse direction, with the result that pressure profiles which are as planar as possible can be produced. This therefore results in a relatively large pressing surface which faces the pressure shoe or its lower part, which results in the pressure which is required to achieve the necessary line force can be kept relatively low. In comparison with pressing using individual pistons, lower pressure levels of the pressure fluid are possible.
The risk of leakage of the pressure fluid is practically precluded. Moreover, reduced manufacturing expenditure and simple assembly result.
The pressure element can be configured, in particular, as a lifting cushion or pressure cushion or as a pressure tube.
In one preferred practical embodiment of the pressing device according to the invention, the pressure element is configured in the form of a folding bellows. Here, the folding bellows can have a plurality of, for example three, outer folds which are preferably circumferential, by which a relatively small initial height is achieved.
The pressure element can have, in particular, a generally cuboidal design.
However, the pressure element can also be formed by a pressure tube which extends preferably axially.
That pressing surface of the pressure element which acts on the pressure shoe or its lower part preferably corresponds at least substantially to the maximum pressure element cross section. This results in a pressing surface which is as large as possible, as a result of which the pressure which is required to achieve the necessary line force can be kept as small as possible.
A plurality of pressure elements which follow one another in the machine running direction and/or a plurality of pressure elements which follow one another in the transverse direction are advantageously provided.
In one expedient practical embodiment having a plurality of pressure elements which follow one another in the machine running direction, in order to vary the line force profile and/or pressure longitudinal profile in the press nip which is formed with the backing surface, the pressure elements can be acted on with pressure fluid at least partially independently of one another.
In one expedient practical embodiment having a plurality of pressure elements which follow one another in the transverse direction, in order to vary the line force profile and/or transverse pressure profile in the press nip which is formed with the backing surface, the pressure elements which follow one another in the transverse direction can be acted on with pressure fluid at least partially independently of one another.
At least three pressure elements which follow one another in the transverse direction are advantageously provided, as a result of which, for example, control in the edge zones is also made possible.
Pressure elements having different lengths can be provided for adaptation to the respective working width.
In one preferred practical embodiment of the pressing device according to the invention having at least three pressure elements which follow one another in the transverse direction, the two pressure elements on the edges have a smaller length, measured in the transverse direction, than the central pressure element or elements.
In order to form a modular system, in accordance with a further refinement of the invention, pressure elements can be provided which have a length which corresponds to a fraction of a working width. Depending on the working width, more or less pressure elements of this type can be arranged behind one another or next to one another. If required, compensation pressure elements having a smaller length are used, in order to fill a remaining part of the working width.
The pressure element preferably has one or more connections to the pressure fluid supply mechanism. Here, ventilation and/or cooling and/or heating of the pressure element is also advantageously possible via the least one connection.
Water, gas, air and/or oil can be provided as pressure fluid, for example.
In one expedient practical embodiment of the pressing device according to the invention, the pressure element is mounted in a pressure bed of the supporting body. This is possible in all vertical and horizontal directions. Here, the pressure element can be fixed, in particular, by a corresponding design of the pressure bed and of the pressure shoe lower part.
The pressure shoe is advantageously assigned at least one return element, by which it can be moved away from the backing surface. Relatively sensitive transverse profiling is possible as a result of a suitable combination of pressure element or pressure elements and return element or return elements.
A respective return element can comprise, in particular, at least one spring element and/or at least one cylinder/piston element.
The length and shape of the pressure element are expediently defined at least partially by stops.
A stop bar can be provided in the center of the working width, for example. As a result, movements of the pressure shoe unit in the working width direction can advantageously be suppressed, and at the same time the deformation-free thermal expansion of the pressure shoe lower part can be permitted. A plurality of stop bars can also be provided, for example in each case on the outer sides of the pressure shoe.
The stop bar can also be provided with sliding strips which can preferably be exchanged, in order to reduce the friction between the stop bars and the bellows or the supporting body.
The stop bar in the center of the working width is preferably configured to be longer than the other stops. Moreover, the stop bar is preferably guided in a U-shaped stop in the center of the working width.
The brackets which serve to connect with the pressure fluid supply mechanism are expediently arranged on that side of the pressure element which faces away from the pressure shoe.
Moreover, it is advantageous for the connections to the pressure fluid supply mechanism to be arranged diagonally relative to the pressure element. In the case of adjacent pressure elements, the brackets are preferably connected to one another in pairs, in particular in an alternating manner on the inlet/outlet side. This results in short connecting paths.
It is also preferred for the connection to be provided below the supporting body upper belt, that is to say its horizontal part, and/or next to the web of the supporting body, that is to say its vertical part. The connections can be accommodated here in a protected manner and do not require any additional space.
The pressure element is preferably composed at least partially of fiber reinforced plastic.
According to a further refinement of the invention, the pressure shoe can be mounted rotatably in the machine running direction, to be precise, in particular, centrally. Moreover, the pressure shoe can also be mounted in the machine transverse direction, in particular in a multiple manner. This has the advantage that a defined position of the pressure shoe results, without stop bars being required. As a result, the pressure shoe is given a position which can be calculated exactly, and the pressure profile can also be calculated exactly. Furthermore, the rotatable mounting can for its part be mounted so as to move freely in the horizontal direction.
According to the invention, two or more pressure elements can also be arranged one above another. Here, one or more dividing plates are preferably arranged between the pressure elements. Pressure pistons can also be provided instead of the lower pressure elements, at least partially. In this way, further variation possibilities and setting possibilities can be realized.
The solution according to the invention is used, in particular, in dewatering devices in machines for manufacturing and/or finishing paper webs, paperboard webs, tissue webs or other fibrous webs. Here, the fibrous web is guided, together with at least one dewatering belt, through a press nip which is formed with the aid of the pressing device. The line force in the press nip preferably lies between 50 and 980 KN and, in particular, between 60 and 210 KN. The use is therefore particularly suitable for the manufacture of tissue webs.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be explained in greater detail in the following text using exemplary embodiments with reference to the drawing, in which:
FIG. 1 shows a diagrammatic cross-sectional illustration of a pressure shoe having an associated pressing device,
FIG. 2 shows a diagrammatic illustration of the pressure element which is shown in FIG. 1 , in a view from below,
FIG. 3 shows a diagrammatic illustration of a further embodiment of the pressing device having two pressure elements which follow one another in the machine running direction and restoring elements which are assigned to the pressure shoe,
FIG. 4 shows a diagrammatic illustration of a further embodiment of the pressing device having only one pressure element, as viewed in the machine running direction, the pressure shoe also being assigned restoring elements in this case again,
FIG. 5 shows a diagrammatic illustration of an embodiment of the pressing device having three pressure elements which follow one another in the transverse direction,
FIG. 6 shows a diagrammatic illustration of an embodiment having a pressure tube,
FIG. 7 shows an illustration, corresponding to FIG. 1 , of a further variant of the invention, and
FIG. 8 shows an illustration according to FIG. 1 of yet another variant of the invention.
DETAILED DESCRIPTION
In a diagrammatic cross-sectional illustration, FIG. 1 shows a pressure shoe 10 having an associated pressing device 12 .
The pressing device 12 comprises at least one pressure element 16 which is supported on a supporting body 14 and is flexible at least in regions. The pressure element 16 has at least one hollow space 18 which can be acted on with pressure fluid, in order to produce a predefinable pressing force via a corresponding pressure element volume.
In the present case, the pressure element 16 has only a single, continuous hollow space 18 .
A flexible belt, for example the flexible press cover of a shoe roll, can be guided over the pressure shoe 10 . Via the pressing unit which acts on the lower part 20 of the pressure shoe 10 , the pressure shoe 10 and thus the relevant flexible belt can be pressed against a backing surface which can be formed, for example, by a backing roll, in order to form an extended press nip.
The pressure element 16 which is configured as a lifting cushion or pressure cushion in the present case is configured to be practically leakfree. As can be seen from FIG. 1 , it is configured in the present case in the form of a folding bellows having, for example, three outer folds 22 which are preferably circumferential.
The pressure element 16 is to have as large a pressing surface 24 as possible which acts on the pressure shoe 10 or its lower part 20 , in order to keep the pressure which is required to achieve the necessary line force as low as possible. This is achieved with the pressure element 16 according to the invention.
The pressure element 16 can, for example, have a generally cuboidal design. That pressing surface 24 of the pressure element 16 which acts on the pressure shoe 16 or its lower part 20 can correspond at least substantially to the maximum pressure element cross section.
Moreover, a connection 26 to the pressure fluid supply mechanism is to be seen in FIG. 1 .
As results from FIG. 2 , the pressure element 16 can in principle also have a plurality of connections 26 to the pressure fluid supply mechanism. In the present case, two connections 26 of this type are provided. As is to be seen from FIG. 2 , the brackets which serve to connect with the pressure fluid supply mechanism are expediently arranged on that side of the pressure element 16 which faces away from the pressure shoe 10 (cf. also FIG. 1 ). Here, a diagonal arrangement of these brackets can be provided for improved throughflow of the pressure fluid.
The pressure element 16 can expediently be acted on with the relevant pressure fluid in a variable manner, in order to produce a pressing force which can be set in a variable manner by a corresponding variation of the pressure element volume.
As results from FIGS. 3 to 5 , a plurality of pressure elements 16 which follow one another in the machine running direction MD and/or a plurality of pressure elements 16 which follow one another in the transverse direction CD can be provided.
FIG. 3 shows a diagrammatic illustration of an embodiment of the pressing device 12 having two pressure elements 16 which follow one another in the machine running direction MD, and also having return or restoring elements 28 which are assigned to the pressure shoe 10 .
The pressure elements 16 which follow one another in the machine running direction MD are provided with separate connections 26 to the pressure fluid source 30 . Here, these pressure elements 16 which follow one another in the machine running direction MD can be acted on with pressure fluid, in particular independently of one another, in order to vary the line force profile and/or longitudinal pressure profile in the press nip which is formed with the backing surface. In the present case, although the pressure elements 16 are connected to the same pressure fluid source 30 , a pressure reducing valve 32 or the like, for example, can be provided in the feed line to one of the two pressure elements 16 , with the result that the two pressure elements 16 can be acted on with different pressures if required.
As is to be seen from FIGS. 3 and 4 , return or restoring elements 28 can be provided both on the front side and on the rear side of the pressure shoe 10 , as viewed in the machine running direction, in order to move the pressure shoe 10 away from the backing surface.
A respective return element 28 can, for example, comprise at least one spring element and/or at least one cylinder/piston element.
FIG. 4 shows a diagrammatic illustration of an embodiment of the pressing device 12 having only one pressure element 16 , as viewed in the machine running direction MD. In this case, the pressure shoe 10 is also again assigned return elements 28 . In the present case, a respective return element 28 can also again comprise, for example, at least one spring element and/or at least one cylinder/piston element.
As is to be seen from FIGS. 3 and 4 , the return elements 28 can be provided on that side of the supporting body 14 which faces away from the pressure shoe 10 , and can be connected to the pressure shoe 10 via pulling elements 34 which extend through the supporting body 14 .
As is to be seen from FIG. 4 , the pressure element 16 is again provided with at least one connection 16 to the pressure fluid supply mechanism 30 .
FIG. 5 shows a diagrammatic illustration of an embodiment of the pressing device 12 having three pressure elements 16 which follow one another in the transverse direction CD.
In order to vary the line force profile and/or transverse pressure profile in the press nip which is formed with the backing surface, the pressure elements 16 which follow one another in the transverse direction CD can be acted on with pressure fluid, in particular again independently of one another. They are therefore again provided with separate connections 26 to the pressure fluid supply mechanism.
In the present case, for example, three pressure elements 16 are provided which follow one another in the transverse direction CD; however, more than three or only two pressure elements 16 can also follow one another in the transverse direction.
In particular, a combination of the embodiments according to FIGS. 3 and 4 with the embodiment according to FIG. 5 is also conceivable.
In FIG. 6 , the pressure shoe 10 is pressed via two pressure elements 16 which lie next to one another in the pressure bed 36 in the direction of rotation, in the form of axially extending pressure tubes. The expansion of the pressure tube in the pressing direction is also set here via the pressure of the pressure fluid in the pressure tube.
Pressure elements 16 having different lengths can be provided for adaptation to the respective working width.
If at least three pressure elements 16 which follow one another in the transverse direction CD are provided, it is possible to control the edge zones, for example, via the pressure elements 16 at the edges. As is to be seen from FIG. 5 , the pressure elements 16 at the edges can have, for example, a smaller length, measured in the transverse direction, than the central pressure element or elements 16 .
The length and shape of the pressure elements 16 can be limited, in particular, by stops.
That pressing surface of a respective pressure element 16 which faces the pressure shoe 10 is relatively great, with the result that the required oil pressure is kept correspondingly low. The brackets for connection to the pressure fluid supply means are arranged on the underside of a respective pressure element 16 (cf. FIG. 2 ). Here, the brackets can be arranged diagonally for improved pressure fluid throughflow (cf., in particular, FIG. 2 again). The respective displacement results from a change in volume by opening of the folds 22 (cf., in particular, FIG. 1 ). The result is a correspondingly lower initial height with a limited number of outer folds 22 (cf. the embodiment according to FIG. 1 having only three outer folds). The pressure elements 16 can, in particular, be composed of fiber reinforced plastic or the like.
A respective pressure element 16 can be mounted in a pressure bed 36 of the supporting body 14 (cf., in particular, FIG. 1 ). Here, the pressure element 16 can be fixed by a corresponding design of the pressure bed 36 and of the pressure shoe lower part 20 .
FIG. 7 shows a pressure shoe 10 which is mounted rotatably via a bearing element 36 in the machine running direction MD, as indicated by arrow 38 . For its part, the mounting 36 is mounted so as to move freely in a horizontal bearing 40 . In this refinement, as shown, two pressure elements 16 are arranged one behind another in the machine running direction MD. In addition, there can also be provision for a rotatable mounting in the machine transverse direction CD, preferably in a multiple manner, which is not shown here.
FIG. 8 shows a variant, in which two pressure elements 16 are arranged one above another. A dividing plate 42 is provided between the two pressure elements 16 . Instead of the lower pressure element 16 , it is also possible for pressure pistons to be provided. Moreover, a plurality of pressure elements 16 can be arranged next to one another, in each case in the machine transverse direction CD, as has been described with respect to the previous exemplary embodiments. The same is true for the variant of FIG. 7 .
LIST OF DESIGNATIONS
10 Pressure shoe
12 Pressing device
14 Supporting body
16 Pressure element
18 Hollow space
20 Lower part
22 Outer fold
24 Pressing surface
26 Connection
28 Return or restoring element
30 Pressure fluid source
32 Pressure reducing valve
34 Pulling element
36 Pressure bed
37 Mounting
38 Arrow
40 Horizontal bearing
42 Dividing plate
MD Machine running direction
CD Transverse direction
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The invention relates to a device ( 12 ) which is used to press a pressure shoe ( 10 ) against a counter surface, comprising at least one at least partially flexible pressure body ( 16 ) which is supported on the bearing body ( 14 ), said pressure body comprising at least one cavity ( 18 ) which can be impinged upon by pressure fluid in order to produce a predetermined pressing force over a corresponding pressure body volume.
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CROSS REFERENCE TO RELATED APPLICATION
This is a continuation-in-part of co-pending U.S. application Ser. No. 09/072,120 filed May 4, 1998.
BACKGROUND OF THE INVENTION
The invention relates in general to refrigeration systems and more specifically to means for providing heat to an evaporator coil which is used in a refrigeration system.
A common problem associated with refrigeration systems, such as transport refrigeration units, relates to the evaporator unit and defrosting the evaporator coil in a timely and efficient manner. The prior art has addressed the problem in several ways.
One approach has been to provide for a flow of hot gas over the frosted coil. This method has not proven to be efficient and causes problems with the refrigerant which tends to migrate back to the condenser.
Another method provides for the use of simple electrical resistance, spaced at a fixed distance from the evaporator coils. To provide radiant heat this method, however, fails to provide for defrosting in a timely or even manner.
It can therefore be seen from the above that there is a need in the field for an efficient way in which to effectively defrost an evaporator coil and avoid creating other problems in the refrigeration system.
Accordingly it is an object of the present invention to provide for means which overcome the problems associated with the frosting or icing of evaporator coils for refrigeration systems.
It is another object to provide an efficient and economical means for heating an evaporator coil yet retain the ease of serviceability and replacement of the hearing means.
It is yet another object of the present invention to provide an effective means for providing heat on demand to an evaporator coil.
It is a further object of the present invention to provide heating means which are integral to an evaporator coil which shorten defrost time.
It is another object of the present invention to provide for electrical heating means which defrost a refrigeration evaporator coil in an efficient and timely manner.
SUMMARY OF THE INVENTION
The present invention is directed to an evaporator unit suitable for use in a refrigeration system which includes heating means integral with the evaporator coil to provide conductive electric heat to the coil on demand or under predetermined conditions.
The evaporator coil, which includes a plurality of contiguous metal cooling fins, further includes means for directly providing heat to the cooling fins. The heating means include a plurality of interconnected electrically heated rods which are in direct contact with the outer surface of the cooling fins of the evaporator coil. In one embodiment, the heating means comprises a several elongated electrically heated metal rods which are arranged in an interconnected parallel array in direct contact with an outer surface of the coil. The metal rods may also be partially embedded in the fins of the coil to enhance conductive heat flow to the coil. The metal rods may be electrically connected in pairs by a common electrical connection to provide heat to the coil by electrical resistance. In another embodiment, the metal rods may be sized to fit between the fins of the coil.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view of a transport refrigeration system.
FIG. 2 is a perspective view of an evaporator coil unit suitable for use in a refrigeration system.
FIG. 3 is a perspective view of a pair of electrically heated rods.
FIG. 4 is an enlarged view of the evaporator coil and mounting frame of FIG. 2 .
FIG. 5 is a sectional view of the coil of FIG. 4 taken along line 5 — 5 .
FIG. 6 is a schematic diagram of a circuit supplied with a DC voltage controlling the heating rods of the present invention, wherein each conductor is routed through a tube pair.
FIG. 7 is a schematic diagram of a circuit supplied with an AC voltage controlling the heating rods of the present invention, wherein each conductor is routed through a tube pair.
FIG. 8 is a top view of a preferred embodiment of the rod pair or the present invention.
FIG. 9 is a side view of the rod pair shown in FIG. 8 .
FIG. 10 is a cross sectional view of the metal rod of FIG. 8 taken along line 10 — 10 .
FIG. 11 is a top view of a rod pair of the prior art.
FIG. 12 is a side view of the rod pair shown in FIG. 11 .
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates a transport refrigeration system more particularly known as a trailer refrigeration unit. As shown in FIG. 1, a truck trailer refrigeration unit 500 integrally includes a mounted diesel engine driven generator 300 and the diesel engine 350 in accordance with a system which may use one embodiment of the present invention. The truck trailer refrigeration unit 500 has the compressor/drive motor unit 116 , 118 and other refrigeration system components. All multi-phase power, single phase power and control system power for the refrigeration unit 500 is provided by the single integrally mounted diesel engine driven generator 300 and associated voltage, current, and frequency controls. The internally mounted diesel engine driven generator 300 also provides the necessary higher voltage ac power to the electrically driven compressor/motor unit 116 , 118 , electrically driven evaporator fans, the electrically driven condenser fans 123 and a host of high power consumption devices such as heaters.
The present invention is illustrated more clearly in FIGS. 2-5. FIG. 2 illustrates an evaporator unit 10 which includes a pair of fans 12 and 14 contained within an outer support frame 16 . Frame 16 contains an inner mounting frame 18 which contains coil evaporator 20 . Coil 20 is made up of a plurality of interconnected spaced metal fins 22 . Separate and apart from the coil are a plurality of interconnected electrically heated rods 24 which are in direct contact with coil fins 22 . Metal brackets 34 , 36 , and 38 function to hold the coil in place within the evaporator unit. The combination of the coil evaporator and interconnected electrically heated rods is called an evaporator coil assembly.
As shown more clearly in FIG. 3, each rod 24 is formed as a tube 25 enclosing an electrical conductor 28 , the conductor 28 dissipating heat according to Joule's law (wherein the heat generated is inversely proportional to the resistance of the conductor for a given voltage). The conductor 28 is preferably connected at one end via a connector 30 to a suitable source of electrical power, and runs through enclosed tube 25 to an electrical connector 32 , and connects to another tube via an electrical connector 32 , and run through that other tube to another connector 30 that connects the conductor to the electrical power ground, or another electrical phase (not shown). Alternatively, rather than each conductor passing through two separate serial rods and thus efficiently connecting proximately to the source and ground, each conductor may be connected at one rod end to the electrical power source and at the other rod end to ground or another electrical phase, and thus routing through only a single rod. In accordance with Joule's law, the resistance per length of each conductor is selected according to the chosen heat generation of each road, the length of each conductor, and the current constraints of the voltage source. Each tube 25 comprises a material that efficiently conducts heat from the conductor to the contacted fin and at the same time protects the enclosed conductor from deleterious environmental contact. The tube material is ceramic, or alternatively metallic wherein the conductor is surrounded by a thin heat conducting dielectric between the metallic tube and the conductor.
As shown more clearly in FIG. 4, mounting frame 18 contains side mounting brackets 34 and 36 and top mounting bracket 38 which hold the coil in place within the evaporator unit. The electrically heated rods are arranged in a parallel array such that they are in direct contact with the coil fins in order to maximize conductive heat flow to the coil, when needed, and provide an integral fit either in or between the fins as desired.
In FIG. 5, which is a sectional view of FIG. 4, taken along a lines 5 — 5 , the location and function of the rods with respect to the evaporator fins is shown in greater detail. It can be seen that the array of the rods uniformly covers a major portion of the surface area of the coil, and in the embodiment illustrated, the coils have been cut at 42 to allow the rod to nest in direct contact in a positive secure fit within the coil. This configuration also provides for a even flow of conductive heat from the rods to the coil.
Referring to FIG. 6, a DC voltage supplied circuit comprises a voltage source 50 , a switch 52 that opens and closes on demand or alternatively in response to predetermined conditions, a conductor 54 that connects via connectors 30 to each heat dissipating conductor 28 , portrayed as three separate conductors 28 a, 28 b, and 28 c. Each conductor 28 runs serially through two rods, electrically connected between each rod by a pair of connectors 32 . Each conductor terminates in a connector 30 that is connected to ground.
Referring to FIG. 7, an AC voltage supplied circuit comprises a voltage source 51 (portrayed here as three phase AC), a switch 53 that opens and closes on demand or alternatively in response to predetermined conditions, conductors 54 a, 54 b, and 54 c that each connect a different phase of the voltage source and connect via connectors 30 to two of the three separate heat dissipating conductors 28 , portrayed as separate conductors 28 a, 28 b, and 28 c. Each conductor 28 runs serially through two rods 24 that are electrically connected between rods by a pair of connectors 32 .
FIGS. 11 and 12 represent the state of the prior art in which a rigid, substantially inflexible rod pair 60 having two metal rods 62 forming a stiff inflexible continuous U-shaped end 64 are used in pairs and partially embedded in an evaporator coil. The width or dimension D illustrated in FIG. 11 is a substantially constant dimension which must be maintained to fit in the notch or holes 42 in the coil fin. Any slight deviation from the exact required dimension results in a misfit or mismatch. Therefore, if the dimensions of the given rod pair, whether it be newly manufactured or a replacement, does not exactly match the dimension of the receiving notches or holes on the evaporators fins, there can be great difficulty in removing or installing a rod pair of this type during manufacturing or servicing.
As shown in FIGS. 8-10, according to a preferred embodiment of the present invention, the rod pair 40 has a flexible rubberized connection 42 at one end of the rod pair which allows for the evaporator coil assembly to be manufactured with more efficiency and also facilities ease of servicing in that the flexible end 42 allows for ease of movement of the two metal side rods 44 . Therefore, in manufacturing an evaporator coil assembly or in servicing, such as replacing a defective or broken rod pair, the flexible end 42 does not require an exact dimensional fit when partially embedded in the coil fins in that there is enough flexibility in the rubberized end to accommodate any dimension which is reasonably close. The main rod structure, as illustrated in FIG. 9 is typically a conductive metal wire 48 , such as copper surrounded by a ceramic material 46 , having an outer metal sheath 44 such as stainless steel. The flexible rubber end 42 surrounds the conductive wire and is connected to a larger vulcanized rubber connector 49 . The opposite end of the rod pair contains a rubberized connector 50 over wire 48 which at the end of the rod, is encased in a smaller diameter rubberized sheath 52 .
The present invention may be used with any conventional refrigeration unit. One example of such a unit is more clearly shown in the Carrier Corp., Transicold Division Operation and Service Manual for Models 69NT40511 and 69NT40521 which is incorporated herein by reference. In particular page 1-7 of the manual illustrates in detail the key operative components of a suitable evaporator unit which may utilize the present invention.
While specific embodiments of the invention have been illustrated and described herein, it is realized that modifications and changes will occur to those skilled in the art. It is therefore to be understood that the appended claims are intended to cover all modifications and changes as fall within the true spirit and scope of the invention.
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An evaporator coil for a refrigeration system which includes a plurality of contiguous metal fins which include means for providing conductive heat to the fins on demand or under a predetermined conditions. The heating means care in the form of a plurality of interconnected electrically heated rods which are in direct contact with the outer surface of the fins of the evaporator coil.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an integrated converter for use as an integrated analog-to-digital converter or an integrated digital-to-analog converter.
2. Description of the Prior Art
Analog-to-digital (A/D) converters include an integrated A/D converter, a successive approximation A/D converter, and a parallel approximation A/D converter among others. The integrated A/D converter (see Japanese Laid-Open Patent Publication No. 60-79811, for example) is capable of converting signals with high accuracy, as with the integrated digital-to-analog (D/A) converter.
FIGS. 1A and 1B of the accompanying drawings show a conventional three-stage cascade integrated A/D converter for converting audio input signals in a frequency range of about 20 kHz. The integrated A/D converter shown in FIGS. 1A and 1B has an A/D converter unit 1 constructed as an integrated circuit (IC). An analog input signal VI supplied through a input terminal 2 to the A/D converter unit 1 is converted into a serial digital signal DS which is outputted from an output terminal 3. The A/D converter unit 1 is supplied with an integrating clock signal MCK, an output clock signal BCK, and an integration start signal WCK through respective terminals 4, 5, 6.
A system clock signal SCK having a frequency of 12 MHz (more accurately, 12.288 MHz) is supplied to an input terminal 7. The frequency of the system clock signal SCK is divided by a frequency divider 8 into a 1/6 frequency, which is then divided by a frequency divider 9 into a 1/32 frequency. The system clock signal SCK is transmitted through a buffer 10A as the integrating clock signal MCK (see FIG. 2A). The output signal from the frequency divider 8 is transmitted through a buffer 10B as the output clock signal BCK (see FIGS. 2B and 2C) which has a frequency of about 2 MHz. The output signal from the frequency divider 9 is transmitted through a buffer 10C as the integration start signal WCK (see FIG. 4D) which has a frequency of 64 kHz.
In the A/D converter unit 1, the input signal VI is supplied to an inverting input terminal of a differential amplifier 14 through a resistor 11 and a first input terminal and an output terminal of a switch circuit 13. The first input terminal of the switch circuit 13 is connected to the output terminal of the differential amplifier 14 through a resistor 12 which has the same resistance as that of the resistor 11. The inverting input terminal of the differential amplifier 14 is connected to the output terminal thereof through an integrating capacitor 15. The differential amplifier 14 has a noninverting input terminal connected to ground. The switch circuit 13 also has second, third, and fourth input terminals supplied with respective reference signals VR1, VR2, VR3 through respective resistors 16, 17, 18. If the input signal VI is of a positive voltage, then the reference signals VR1, VR2, VR3 are of negative voltages. With the resistors 16, 17, 18 being of equal resistances, since 2 5 =32, the following equations are satisfied:
VR1=32×VR2, VR2=32 VR3.
A converted output signal VC produced from the differential amplifier 14 is supplied to inverting input terminals of comparators 19, 20, 21 whose noninverting input terminals are supplied with reference signals having a voltage level El, a voltage level E2, and a ground level, respectively. Output signals from the respective comparators 19, 20, 21 and the integrating clock signal MCK are supplied to a clock signal selector 22. The voltage levels El, E2 are of negative voltages, respectively. If the level difference between an input voltage and a 1-bit output voltage is expressed as ΔE, then the following equations are satisfied:
E1=32×E2, E2=32×ΔE.
The clock signal selector 22 supplies the integrating clock signal MCK to a high-order counter 23 when the output signals from the comparators 19, 20, 21 are of a high level of "1", to an intermediate-order counter 24 when only the output signals from the comparators 20, 21 are of a high level of "1", and to a low-order counter 25 when only the output signal from the comparator 21 is of a high level of "1". Each of the counters 23, 24, 25 comprises a 5-bit binary counter. Output count signals from the counters 23, 24, 25 correspond respectively to high-order five bits, intermediate-order five bits, and low-order five bits, of a converted 15-bit output signal. These parallel output count signals from the counters 23, 24, 25 and the output clock signal BCK are supplied to a shift register 26. The shift register 26 supplies its output signal as the serial digital signal DS to the output terminal 3 in synchronism with the output clock signal BCK.
The A/D converter unit 1 also includes a control circuit 27 which is supplied with the integrating clock signal MCK and the integration start signal WCK. The control circuit 27 is also supplied with a signal indicative of the address of the counter 23, 24, or 25 which is being supplied with the integrating clock signal MCK, from the clock signal selector 22. When the integration start signal WCK is of a low level of "0", the control circuit 27 controls the switch circuit 13 to select the first input terminal to integrate the input signal VI. When the integration start signal WCK is of a high level of "1", the control circuit 27 controls the switch circuit 13 to select one of the reference signals VR1, VR2, VR3 depending on the selection by the clock signal selector 22 of the counter 23, 24, or 25. Immediately after the integration start signal WCK goes high, the control circuit 27 clears the counts of the counters 23, 24, 25 through a line (not shown). Immediately after the integration start signal WCK goes low, the control circuit 27 loads the parallel data into the shift register 26.
Operation of the conventional integrated A/D converter shown in FIGS. 1A and 1B will be described below with reference to FIGS. 2A through 2E. FIGS. 2C through 2E show signal waveforms in a period T5 (FIG. 2A) corresponding to 96×2 pulses of the integrating clock signal MCK. The integration start signal WCK is obtained by dividing the frequency of the integrating clock signal MCK by 6×32, and the period T5 of the integrating clock signal MCK is equivalent to the period of the integration start signal WCK.
During an interval in which the signal WCK is of a level of "0" in the period T5, the switch circuit 13 selects the input signal VI. Since the capacitor 15 is quickly charged with a current of the signal VI, the converted output signal VC from the differential amplifier 14 becomes a signal which is opposite in polarity and equal in magnitude to the signal VI, as indicated by the solid-line curve 28 in FIG. 2E. Therefore, the input signal VI is sampled during this interval. When the signal WCK thereafter goes high, the control circuit 27 clears the counts of the counters 23, 24, 25, and then causes the switch circuit 13 to select any one of the reference signals VR1, VR2, VR3 depending on the address information from the clock signal selector 22.
More specifically, as shown in FIG. 2E, during an interval T1 in which the converted output signal VC is lower than the level E1, the switch circuit 13 selects the reference signal VR1, and the high-order counter 23 is supplied with the integrating clock signal MCK. While the reference signal VR1 is being integrated by the capacitor 15 (i.e., discharged thereby in the illustrated arrangement), pulses of the clock signal MCK are counted by the high-order counter 23. During an interval T2 in which the converted output signal VC is of a level between the levels El, E2, the reference signal VR2 and the intermediate-order counter 24 are selected. During an interval T3 in which the converted output signal VC is of a level between the level E2 and the ground level 0, the reference signal VR3 and the low-order counter 25 are selected. The integrated value produced by the capacitor 15 as the converted output signal VC becomes zero, the low-order counter 25 stops counting the pulses. Therefore, a binary code composed of a serial combination of the 5-bit output signals from the counters 23, 24, 25 serves as the digitally converted data of the input signal VI. Stated otherwise, according to the three-stage integrating arrangement shown in FIG. 1, since 2 5 =32 and 3 ×32=96 for 15-bit digital conversion, only 96 pulses are required to be used as the integrating clock signal MCK. If 15-bit digital conversion were to be effected by one-stage integration, however, since 2 1 5 =32768, 32678 pulses are required for use as the integrating clock signal MCK.
When the integration start signal WCK becomes "0", the control circuit 27 loads the 15-bit data into the shift register 26, and enables the switch circuit 13 to select the input signal VI again. The shift register 26 supplies the 15-bit data serially to the output terminal 3 in synchronism with the output clock signal BCK, and at the same time the input signal VI starts being sampled.
If the A/D converter is used to convert an ordinary audio signal, then another integrator comprising a differential amplifier 14 is connected parallel to the existing differential amplifier 14, for integrating a right channel input signal, the existing differential amplifier 14 integrating a left channel input signal, which may be the input signal VI. While the integration start signal WCK is being of a level of "1", the right channel input signal is sampled, and while the integration start signal WCK is being of a level of "0", the right channel input signal is converted into a digital signal. The shift register 26 alternately supplies the left channel 15-bit data and the right channel 15-bit data to the output terminal 3. In this manner, two-channel input signals are successively converted into digital signals at 64 kHz.
When the input signal VI is reduced in amplitude, the sampled converted output signal VC is of a waveform as indicated by the broken-line curve 29 in FIG. 2E, and the integrated voltage gradients during analog-to-digital conversion are the same as those when the input signal VI is higher in amplitude.
Recently, research has been carried out to incorporate in portable battery-operated electrocardiographs A/D converters for converting analog bioelectric signals, such as electrocardiographic signals, into digital signals for digital signal processing. The A/D converters for such medical applications are supplied with input signals whose frequencies range from 0 to 100 Hz, and are required to have a minimum electric power requirement. If A/D converters for audio signal processing use can be used as A/D converters for medical use, then it will be possible to lower the cost of developing and manufacturing electrocardiographs.
ICs of the CMOS configuration consume electric energy at positive- or negative-going edges of pulses, and hence their electric energy consumption generally increases in proportion to the frequencies of various clock signals used in the ICs. Therefore, inasmuch as the frequencies of input signals such as bioelectric signals are about 1/100 of audio frequencies, when the frequencies of the integrating clock signal MCK, the output clock signal BCK, and the integration start signal WCK in the A/D converter shown in FIGS. 1A and 1B are reduced to 1/100, the electric power consumption by the A/D converter unit 1 as it is used in medical applications may be reduced to 1/100 of the electric power consumption for audio signal processing applications.
When the frequency of the integrating clock signal MCK in FIGS. 1A and 1B is to be reduced to 1/100, it is necessary to reduce the integrated voltage gradients to 1/100 (the time constant is increased 100 times) in the periods T1 through T3 shown in FIG. 2E. However, if the time constant is increased 100 times, the capacitance of the integrating capacitor 15 is too large or the integrating current is too small, resulting in unstable operation. Conversely, if the integrated voltage gradients were too small, then it would be difficult to determine the end of an integration process through zero-crossing detection of the converted output voltage VC, with the results that a conversion error would be increased and the tendency to induce noise would also be increased.
In order to set a sampling frequency for the input signal VI in the A/D converter shown in FIGS. 1A and 1B to 640 Hz, for example, for bioelectric signals, it may be desirable to sample and convert the input signal VI once during the period T5 (1/T5=64 kHz) as is the case with the conventional arrangement, and to introduce the finally produced 15-bit digital signal in a period T4 (T4=100 T5). However, though the sampling frequency for the input signal is reduced to 1/100, the electric power consumption cannot be reduced since it remains the same as that of the conventional A/D converter.
OBJECTS AND SUMMARY OF THE INVENTION
It is an object of the present invention to provide an integrated converter which is capable of effecting stable conversion from analog to digital signals or vice versa and consumes a reduced amount of electric energy when the integrated converter operates at a conversion rate that is lower than the original conversion rate originally designed for the integrated converter.
According to the present invention, there is provided an integrated converter comprising integrating means for integrating reference signals in synchronism with an integration start signal, counting means for counting integrating clock pulses until the integrated value of the integrating means reaches a value corresponding to an input signal, thereby to convert the input signal into a digital or analog signal based on the count of the counting means, and a gate for gating the integrating clock pulses to supply the integrating clock pulses to the counting mean only during a predetermined period in synchronism with the integration start signal, so that the integrating clock pulses are supplied to the counting means only during an integrating period for the reference signals.
The gate comprises an AND gate having first and second input terminals, the first input terminal being supplied with the integrating clock pulses, further including a counter for applying a high-level signal to the second input terminal of the AND gate while the count of the counter is lower than a predetermined value.
The integrated converter may typically be used as an integrated analog-to-digital converter or an integrated digital-to-analog converter.
Only during the integrating period for the reference signals, the integrating clock pulses are supplied as a burst of pulses to the counting means. Since no integrating clock pulses are supplied to the counting means in an interval except the integrating period, the electric power consumption due to the integrating clock pulses is reduced. The frequency at which the input signal is converted is lowered by lowering only the integration start signal but not lowering the frequency of the integrating clock pulses. In this manner, the electric power consumption due to the integrating clock pulses is greatly reduced.
The above and other objects, features, and advantages of the present invention will become apparent from the following detailed description of an illustrative embodiment thereof to be read in conjunction with the accompanying drawings, in which like reference numerals represent the same or similar objects.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A and 1B are block diagrams of a conventional integrated converter;
FIGS. 2A through 2E are timing charts showing signals produced in the conventional integrated converter shown in FIGS. 1A and 1B;
FIGS. 3A and 3B are block diagrams of an integrated converter according to the present invention; and
FIGS. 4A through 4E are timing charts showing signals produced in the integrated converter shown in FIGS. 3A and 3B.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIGS. 3A and 3B show an integrated converter according to the present invention. The integrated converter shown in FIGS. 3A and 3B is in the form of an analog-to-digital (AD) converter which is originally designed for converting audio signals into digital signals at a conversion frequency of 64 kHz, but modified for conversion at a frequency of 640 Hz, so that it may be used as an A/D converter in an electrocardiograph or the like which handles low-frequency bioelectric signals.
Those parts shown in FIGS. 3A and 3B which are identical to those in FIGS. 1A and 1B are designated by identical reference numerals and will not be described in detail below.
The A/D converter shown in FIGS. 3A and 3B additionally has a frequency divider 30 having a frequency division ratio of 1/100, an AND gate 31, and a counter 32 with a limit signal output terminal OUT. The counter 32 produces, from the limit signal output terminal OUT, a limit signal which is of a high level of "1" when the count of the counter 32 is 96 or lower, and of a low level of "0" when the count exceeds 96.
The input terminal 7 is supplied with a system clock signal SCK (see FIG. 2A) having a frequency of 12 MHz (more accurately, 12.288 MHz) from a data processor (not shown). The system clock signal SCK is supplied to the input terminal of the frequency divider 30, one input terminal of the AND gate 31, and the clock terminal CK of the counter 32. The clock signal whose frequency has been divided into 1/100 by the frequency divider 30 is supplied through the frequency divider 8 to the frequency divider 9 and the buffer 10B. The output signal from the frequency divider 9 is supplied to the clear terminal CL of the counter 32 and the buffer 10C. The limit signal from the counter 32 is supplied to the other input terminal of the AND gate 31, whose output signal is supplied to the buffer 10A.
The output signals from the buffers 10A, 10B, 10C serve respectively as an integrating clock signal MCK (see FIG. 4D) having burst pulses of a frequency of 12 MHz, an output clock signal BCK (see FIG. 4C) having a frequency of about 20 kHz, and an integration start signal WCK (see FIG. 4B) having a frequency of 640 Hz. These clock signals are supplied through the terminals 4, 5, 6 to the A/D converter unit 1. The A/D converter unit 1 and the manner in which the buffers 10A, 10B, 10C are connected to the A/D converter 1 in FIGS. 3A and 3B are the same as with the A/D converter shown in FIGS. 1A and 1B, and therefore will not be described in detail below.
Operation of the A/D converter shown in FIGS. 3A and 3B will now be described below with reference to FIGS. 4A through 4E. The A/D converter shown in FIGS. 3A and 3B serves to convert an analog input signal VI into a 15-bit serial digital signal DS with a sampling frequency of 640 Hz. The count of the counter 32 is cleared by a positive-going edge of the integration start signal WCK having a period T4 (1/T4=640 Hz). The limit signal from the counter 32 is of "1" during a period T6 after the count is cleared and until all of 96 pulses of the system clock signal SCK are supplied to the clock terminal CK. As shown in FIG. 4D, the integrating clock signal MCK comprises a burst of successive 96 count pulses having a frequency of 12 MHz only in each period T6. The count pulse bursts of the integrating clock signal MCK are periodically generated at a frequency of 640 Hz.
The A/D converter unit 1 operates in the same manner as the A/D converter unit 1 shown in FIGS. 1A and 1B. While the integration start signal WCK is of a low level of "0", the input signal VI is sampled. When the integration start signal WCK is a high level of "1", the input signal VI is converted into a digital signal. Since the capacitance of the integrating capacitor 15 is the same as that of the integrating capacitor 15 shown in FIGS. 1A and 1B, the analog-to-digital conversion is completed within the period T6 after a positive-going edge of the signal WCK. As shown in FIG. 4E where the period T6 is shown at an enlarged scale, the counters 23, 24, 25 count the pulses of the integrating clock signal MCK in the interval T1 in which the converted output signal VC from the differential amplifier 14 is lower than the level E1, in the interval T2 in which the converted output signal VC is of a level between the levels E1, E2, and in the interval T3 in which the converted output signal VC is of a level between the levels E2, 0. When the converted output signal VC reaches the level 0, the 15-bit converted data are established. Because the capacitance of the capacitor 15 is the same as that shown in FIGS. 1A and 1B, the integrator composed of the differential amplifier 14 and the capacitor 15 effects integrating operation highly stably without the danger of inducing a conversion error.
When the integration start signal WCK thereafter goes low, i.e., to the level "0", the 15-bit converted data are loaded into the shift register 26, which supplies the converted data as the digital signal DS to the output terminal 3 in synchronism with the output clock signal BCK having the frequency of 20 kHz. At the same time that the digital signal DS is outputted to the output terminal 3, the differential amplifier 14 samples the input signal VI in a next cycle.
The electric power consumption by the A/D converter shown in FIGS. 3A and 3B will be considered below. The A/D converter unit 1 in the form of an IC is supplied with the integrating clock signal MCK, which has the highest frequency of 12 MHz among all the signals involved and affects the electric power consumption, only in the period T6 in each period T4. Therefore, the electric energy consumed by the A/D converter unit 1 with respect to the integrating clock signal MCK is about T6/T4 compared with the electric energy consumed by the conventional A/D converter unit. Since T6/T4=96/(100·6·32)=1/200, the electric energy consumed by the A/D converter unit 1 shown in FIG. 3 is about 1/200 of the electric energy consumed by the A/D converter unit 1 shown in FIGS. 1A and 1B. Therefore, if the A/D converter shown in FIGS. 1A and 1B is used to convert the input signal with a frequency which is 1/N (N is an frequency, then the electric energy consumed by the A/D converter is reduced to about 1/2N.
Though the frequency divider 30, the AND gate 31, and the counter 32, which are added to the A/D converter shown in FIGS. 3A and 3B, consume a certain amount of electric energy, it is negligibly small compared with the electric energy consumption by the entire A/D converter unit 1 since the buffers of the IC generally consume a major proportion of electric energy.
The A/D converter according to the present invention can convert analog signals into digital signals highly stably and accurately, and its electric power consumption is greatly reduced in substantial proportion to the conversion frequency used.
While the present invention has been described and shown as being applied to an integrated A/D converter, the principles of the present invention are also applicable to an integrated D/A converter.
With the present invention, as described above, the electric power consumption due to the integrating clock signal is reduced in intervals except the integrating periods for reference signals. Therefore, when the integrated converter operates at a frequency lower than the frequency designed originally therefor, the integrated conversion can integrate the input signal highly stably and reduce the electric power consumption during operation.
Although a certain preferred embodiment has 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.
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An integrated A/D converter includes an integrator 8integrating reference signals in synchronism with an integration start signal, and counters for counting integrating clock pulses until the integrated value of the integrator reaches a value corresponding to an input signal, thereby to convert the input signal into a digital or analog signal based on the counts of the counters. An AND gate supplies the integrating clock pulses to the counters only during a predetermined period in synchronism with the integration start signal, so that the integrating clock pulses are supplied to the counters only during an integrating period for the reference signals.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is related to the following Patent Applications: U.S. Patent Application Ser. No.______ filed Sep. 10, 2003, entitled “Printing Digital Documents” (HP reference 200207150-1; Attorney docket 621239-6); U.S. Patent Application Ser. No.______ filed Sep. 10, 2003, entitled “Location Patterns And Methods And Apparatus For Generating Such Patterns” (HP reference 200310542-1; Attorney docket 621241-9); U.S. Patent Application Ser. No.______ filed Sep. 10, 2003, also entitled “Location Patterns And Methods And Apparatus For Generating Such Patterns” (HP reference 200310543-1; Attorney docket 621242-7); British Patent Application No.______ filed Sep. 10, 2003, entitled “Methods, apparatus and software for printing location pattern” (HP reference 200300566-1; Attorney docket JL3824); and, British Patent Application No.______ filed Sep. 10, 2003, entitled “Printing of documents with position identification pattern” (HP reference 200310132-1; Attorney docket ASW1329).
FIELD OF THE INVENTION
[0002] The present invention relates to methods and apparatus for generating position identifying pattern, which can be detected by a suitable detection system. The pattern may be applied to a product such as a document, which may be a form, label or note pad, or any other form of product suitable for such marking, such as a packaging product.
BACKGROUND TO THE INVENTION
[0003] It is known to use documents having such position identification pattern in combination with a pen having an imaging system, such as an infra red sensitive camera, within it, which is arranged to image a small area of the page close to the pen nib. The pen includes a processor having image processing capabilities and a memory and is triggered by a force sensor in the nib to record images from the camera as the pen is moved across the document. From these images the pen can determine the position of any marks made on the document by the pen. The pen markings can be stored directly as graphic images, which can then be stored and displayed in combination with other markings on the document. In some applications the simple recognition that a mark has been made by the pen on a predefined area of the document can be recorded, and this information used in any suitable way. This allows, for example, forms with check boxes on to be provided and the marking of the check boxes with the pen detected. In further applications the pen markings are analysed using character recognition tools and stored digitally as text. Systems using this technology are available from Anoto AB and described on their website www.Anoto.com.
[0004] In order to allow documents to be produced easily with the position identifying pattern on them, it is desirable for the pattern to be suitable for printing on the types of printer that are readily available to a large number of users, such as an ink jet, laser jet or LEP printer. These are digital printers and typically have a resolution of 300, 600 or 1200 dots per inch, and the accuracy with which each dot can be located is variable. Also such printers are generally either monochrome, or, if they are colour printers, have only a small number of ink colours. Therefore, if it is desired to print position coding pattern on a part of a product which has human visible content on it as well, it can be a problem to ensure that the position identifying pattern can be distinguished from the content by the reading device, and that the content remains clearly visible to the human eye, and distinguishable over the content.
SUMMARY OF THE INVENTION
[0005] According to a first as aspect of the invention there is provided a method of generating an image comprising a position identifying pattern and a content feature, the method comprising the steps of: generating the pattern and the content feature each as a plurality of graphical elements, and superimposing the content feature and the pattern, wherein the content elements are smaller than the pattern elements in at least one dimension. This can enable the pattern elements within the superimposed area to be machine read, for example by a digital pen.
[0006] The step of generating the content feature may comprise the steps of: defining the content feature, determining whether the content feature is to be superimposed on the pattern and, if it is, converting the content feature so that it comprises said content elements. This ensures that substantially any content feature can be printed with the pattern. Clearly some initial content features will be modified more than others in the conversion process to enable them to be distinguished from the pattern. Content features which are already formed from a number of graphical elements may simply require changes to the size or spacing of those elements. Content features which are initially solid colour, for example solid black, will need to be broken down into separate graphical content elements.
[0007] The method may comprise, before the converting step, determining whether the content feature already comprises said content elements and, only if it does not, performing the converting step. This allows features which are already in a form which can be superimposed on the pattern, without preventing the pattern from being read, to be printed in their original form without undergoing any further modification.
[0008] The content marks may be smaller in two dimensions, which may be orthogonal dimensions, than the pattern marks, and may each be smaller in area than the pattern marks.
[0009] The difference in size between the pattern elements and the content elements, which is required to enable the pattern to be machine read, will depend on the details of the reading device. If the reading device is arranged to recognize marks in a predetermined range of sizes as being pattern elements, then the content elements need to be of a size that is well outside that range to ensure that the reading device does not erroneously identify the content elements as pattern elements. For example the content elements may be no bigger than half as big, in said one dimension, as the pattern elements. Where the content elements comprise discrete dots, they may be, on average, no bigger than a third, or even a quarter, of the area of the pattern elements.
[0010] When applied to a product the pattern elements may each be formed from a plurality of dots or pixels merged together to form a substantially solid mark, and the content elements may each be formed from at least one dot or pixel. This is how the product can be printed on a printer, such as an inkjet, laser jet or LEP printer. Such printers apply ink or torier in a large number of discrete areas, or pixels, which are the smallest areas that the printer can mark individually. The content elements may therefore each comprise a single pixel, thereby being as small as the printer can make them. Alternatively they may each be made up of a plurality of pixels merged together into a single mark.
[0011] The pattern and the content may be printed substantially simultaneously in a one-pass printing process, i.e. on a single pass of a carrier through the printer. This allows the product, which may be a document, label, packaging article, or any other printed product, to be printed on demand on ordinary plain paper, card or other carrier material. Alternatively the content and the pattern may be printed onto the product separately, for example the content may be printed onto the product which has already been printed with the position identifying pattern.
[0012] The present invention is particularly suitable to monochrome printing. However, it can also be used with colour printers, and may indeed be advantageous under some circumstances. For example, colour printers can often be set to print in grey scale, which causes them to mix the different coloured toners, such as cyan, magenta and yellow, to produce different shades of grey. When operating in this mode colour printers can advantageously be operated according to the invention. Also where a colour printer has run out of one or more ink colours it may become necessary to print the content and the position identifying pattern using the same colour, for example to print some of the content in black ink as well as the pattern. Again, in these circumstances, the present invention can usefully be used.
[0013] The density of the content elements, which may for example be measured as the total area of content elements per unit area of the image, may be greater than the density of the pattern elements, which may be measured as the total area of the pattern elements per unit area of the image. As the density of the content elements increases the visibility, to a human reader, of the content over the pattern increases, but the ease with which the pattern can be machine read by a reading device, such as a digital pen, decreases. For example, where the content is to be applied as a grey scale, the density may be measured as the grey scale of the content. This is particularly applicable to monochrome printing methods. Where colour printing or marking methods are used for the content, the density may be defined as the average reflectivity of the defined content within a particular wavelength. For example if the pattern is to be produced in some regions using a marking material having a reflectivity in a particular wavelength, then the density can be defined as the average reflectivity of the content within that range of wavelengths. Other measures of density may also be used. For example, where the content is to be applied as a grey scale, the density may be measured as the grey scale of the content. This is particularly applicable to monochrome printing methods. Where colour printing or marking methods are used for the content, the density may be defined as the average reflectivity of the defined content within a particular wavelength. For example if the pattern is to be produced in some regions using a marking material having a reflectivity in a particular wavelength, then the density can be defined as the average reflectivity of the content within that range of wavelengths.
[0014] The minimum possible contrast between the individual pattern marks and the content, which allows the reading device to detect the pattern, depends on various factors relating to the reading device, including the resolution of its imaging device and the processing methods it uses to analyse the pattern.
[0015] According to a second aspect of the invention there is provided a corresponding system for generating an image.
[0016] According to a third aspect of the invention there is provided a product having a position identifying pattern and a content feature applied to it, wherein the pattern comprises a plurality of discrete pattern marks each being of at least a predetermined size, the content feature comprises content marks, the content and the pattern are superimposed on each other within at least an area of the product, said area having two dimensions, and within said area the content marks are smaller than the pattern marks in at least one of the dimensions.
[0017] According to a fourth aspect of the invention there is provided a method of analysing a position identifying pattern on a product, the product having thereon the position identifying pattern comprising a plurality of pattern elements and a content feature comprising a plurality of content elements, the content elements being smaller than the pattern elements, the method comprising the steps of forming an image of an area of the pattern and the content, and processing the image to extract the pattern from the content on the basis of the relative sizes of the pattern elements and the content elements.
[0018] A corresponding system for analysing a position on a product is also provided.
[0019] According to a further aspect of the invention there is provided a data carrier carrying data arranged to control a computer system to operate as a system according to the invention, or to carry out the methods of the invention.
[0020] The data carrier can comprise, for example, a floppy disk, a CDROM, a DVD ROM/RAM (including +RW, −RW), a hard drive, a non-volatile memory, any form of magneto optical disk, a wire, a transmitted signal (which may comprise an internet download, an ftp transfer, or the like), or any other form of computer readable medium.
[0021] Preferred embodiments of the present invention will now be described by way of example only with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1 shows a document according to an embodiment of the invention and a digital pen according to and embodiment of the invention;
[0023] FIG. 2 shows a part of a position identifying pattern on the document of FIG. 1 ;
[0024] FIG. 3 shows a part of the position identifying pattern of the document of FIG. 1 with a content feature superimposed thereon;
[0025] FIG. 4 shows a part of the position identifying pattern of the document of FIG. 1 with a darker content feature superimposed thereon;
[0026] FIG. 5 shows a system, according to an embodiment of the invention, for printing the document of FIG. 1 ;
[0027] FIG. 6 shows some of the functional units within the computer of the system of FIG. 5 ;
[0028] FIG. 7 shows a part of a position identifying pattern and content on a document according to a further embodiment of the invention; and
[0029] FIG. 8 shows part of a process according to an embodiment of the invention for analysing the pattern and content on the document of FIG. 1 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0030] Referring to FIG. 1 , a document 2 according to an embodiment of the invention for use in a digital pen and paper system comprises a carrier 3 in the form of a single sheet of paper 4 with position identifying markings 5 printed on some parts of it. The markings 5 , which are not shown to scale in FIG. 1 , form a position identifying pattern 6 on the document 2 . Also printed on the paper 4 are further markings 7 which are clearly visible to a human user of the document, and which make up the content of the document 2 . The content 7 is in the form of a number of lines which extend over, and are therefore superimposed upon, the pattern 6 .
[0031] The pen 8 comprises a writing nib 10 , and a camera 12 made up of an infra red (IR) LED 14 and an IR sensor 16 . The camera 12 is arranged to image a circular area of diameter 3.3 mm adjacent to the tip 11 of the pen nib 10 . A processor 18 processes images from the camera 12 taken at a specified sample rate. A pressure sensor 20 detects when the nib 10 is in contact with the document 2 and triggers operation of the camera 12 . Whenever the pen is being used on an area of the document 2 having the pattern 6 on it, the processor 18 can determine from the pattern 6 the position of the nib 10 of the pen whenever it is in contact with the document 2 . From this it can determine the position and shape of any marks made on the patterned areas of the document 2 . This information is stored in a memory 22 in the pen as it is being used. When the user has finished marking the document 2 , this is recorded in a document completion process, for example by making a mark with the pen 8 in a send box 9 . The pen is arranged to recognise the pattern in the send box 9 and send the pen stoke data to a pen stroke interpretation system in a suitable manner, for example via a radio transceiver 24 which provides a Bluetooth radio link with an internet connected PC. Suitable pens are available from Logitech under the trade mark Logitech Io.
[0032] Referring to FIG. 2 , the position identifying pattern 6 is made up of a number of graphical elements in the form of black ink dots 30 arranged on an imaginary grid 32 . The grid 32 , which is shown in FIG. 2 for clarity but is not actually marked on the document 2 , can be considered as being made up of horizontal and vertical lines 34 , 36 defining a number of intersections 40 where they cross. The intersections 40 are of the order of 0.3 mm apart, and the dots 30 are of the order of 100 μm across. One dot 30 is provided at each intersection 40 , but offset slightly in one of four possible directions up, down, left or right, from the actual intersection 40 . The dot offsets are arranged to vary in a systematic way so that any group of a sufficient number of dots 30 , for example any group of 36 dots arranged in a six by six square, will be unique within a very large area of the pattern. This large area is defined as a total imaginary pattern space, and only a small part of the pattern space is taken up by the pattern on the document 2 . By allocating a known area of the pattern space to the document 2 , for example by means of a coordinate reference, the document and any position on the patterned parts of it can be identified from the pattern printed on it. An example of this type of pattern is described in WO 01/26033.
[0033] Referring to FIG. 3 , the content markings 7 are made up of a regular square array of discrete, equally spaced, graphical elements, in the form of content dots 50 , each of which is significantly smaller in both the horizontal and vertical dimensions, and in area, than each of the pattern dots 30 . The content dots 50 are also spaced apart in both the horizontal and vertical directions. In this case the content dots 50 are each formed from a single dot or pixel of a 1200 dpi printer, and each dot is separated from the adjacent dots 50 , both vertically and horizontally, by a space equivalent to the size if one single printer pixel. They therefore have a nominal diameter of 21 μm, and are spaced apart so that their centres are spaced at intervals of twice their diameter, i.e. 42 μm. If the content dots 50 were exactly circular and had a diameter of exactly 21 μm, then the content dots 50 would cover about 20% of the area to which they are applied, the spaces between them would make up the other 80%. In practice, each printer dot is arranged to be larger in diameter than the spacing between the dot centres, so as to ensure that total coverage is achieved in a black area where all of the dots are applied. Therefore the coverage produced by the content dots 50 will be higher than 20%. Assuming the pattern dots are 100 μm in diameter, they cover about 9% of the area to which they are applied. This means that, to the human eye, the content is clearly visible and distinguishable as a darker shade of grey over the position identifying pattern.
[0034] Referring back to FIG. 1 , the processor 18 in the pen 8 receives a digital image of the combined pattern and content, as shown in FIG. 3 , from the camera 12 and then processes the image in a known manner to identify the pattern dots 30 . The processor 18 can identify the pattern dots 30 provided they are within a predetermined size range around 100 μm diameter, have at least a predetermined contrast with the background, defined as the relative level of absorption of light within a specific range of wavelengths, and are spaced apart with a grid spacing that is within a predetermined range around 300 μm. Therefore, because the content dots 50 are considerably smaller than the acceptable range of pattern dot sizes, and have a completely different spacing from the pattern dots 30 , and produce a light enough grey scale to maintain sufficient contrast with the pattern dots 30 , the pen can still identify the pattern dots 30 where the content 7 is superimposed on the pattern. The processor then analyses the positions of the pattern dots 30 and determines from them the position of the imaged area within the total pattern space. This process is then repeated at each sample period, so that the pen can determine the position of pen strokes made on the document 2 as they are made. This pen stroke data is stored as in the pen's memory 22 for transmission to a pen stroke interpretation device as described above.
[0035] The density, or grey scale, of the content dots can vary up to a certain limit, above which the pen 8 is unable to reliably read the pattern 7 . Using the normal grey scale where 0 represents black and 255 represents white, a grey scale of from 255 down to about 200, which represents about 30% coverage of black ink on a white carrier, can be used with the pen 8 . FIG. 4 shows an area of a document in which the pattern dots 30 and the content dots 50 are the same size as in FIG. 3 , but the content dots are closer together covering about 75% of the document surface. In this case the contrast between the pattern dots 30 and the surrounding areas of content dots 50 is not sufficient for the pen 8 described above to be able to read the pattern dots.
[0036] Referring to FIGS. 5 and 6 , a very simple system according to an embodiment of the invention for producing printed documents having the position identifying pattern on them comprises a personal computer (PC) 200 and a printer 202 . The PC 200 has a screen 204 , a keyboard 206 and a mouse 208 connected to it to provide a user interface 209 as shown generally in FIG. 6 . As also shown in FIG. 6 , the PC 200 comprises a processor 210 and a pattern allocation module 212 which is a software module stored in memory. The pattern allocation module 212 includes a definition of a total area of pattern space and a record of which parts of that total area have been allocated to specific documents, for example by means of coordinate references. The PC 200 further comprises a printer driver 214 , which is a further software module, and a memory 216 having electronic documents 218 stored in it. The user interface 209 allows a user to interact with the PC 200 .
[0037] The printer 202 can be any printer which has sufficient resolution to print the pattern dots 30 and the content dots 50 . In this case it is a 1200 dots per inch (dpi) monochrome laser jet printer. It will be appreciated that the dimensions of the content dots 50 correspond to the dimensions of single pixel of ink from a 1200 dpi printer, and that the spacing between the content dots 50 is twice the spacing of the printer pixels. This enables the printer to print the content dots 50 as single ink dots and the pattern dots 30 as groups of ink dots, for example about 12 dots. The printer dots are not exactly circular but each comprise an irregular mark of ink on the document 2 . However the exact shape of the content dots 50 is not important as the human eye cannot see their shape, and the pattern dots 30 , because they are made up of a group of printer dots, are close enough to a regular shape to be read by the pen 8 . Because they can be distinguished by the pen 8 by virtue of their size, the pattern dots 30 and content dots 50 can be printed using the same type of ink from the monochrome printer. Where a colour printer is used, the ink which is used for the pattern, which would typically be a black ink, can also be used for part of the content where appropriate.
[0038] In order to produce the printed document 2 the processor 210 retrieves an electronic document 218 , which may be in the form of a PDF file, from the memory 216 and sends it to the printer driver together with instructions as to whether it is to be printed with pattern or not. The electronic document 218 contains a definition of the content 7 , and the areas of the document 2 which can have the pattern 6 printed on it. The printer driver then determines from the instructions received whether the document is to be printed with pattern or not. If the document is to be printed without pattern on it, the content is sent for printing. If the document is to be printed with pattern on, the printer driver converts checks the nature of the content to determine whether it is already made up of graphical elements of a suitable format to enable the pattern to be read when the pattern and content are superimposed. If the content is already made up of suitable graphical content elements, then the printing process can proceed. If the content is not suitable made up, for example if it includes areas of solid black, then it is converted so that it is made up entirely of content elements 50 as described above.
[0039] When it is determined that the content is all in a suitable format, the printer driver 214 requests the required amount of pattern from the pattern allocation module 212 which allocates by means of coordinate references an area of the pattern space to the document, generates the pattern 6 for that area using a pattern generation algorithm, and communicates the details of the pattern including the positions of all the required dots, back to the printer driver 214 . The printer driver 214 then combines the content 7 and the pattern 6 into a single electronic file. This file therefore forms a combined electronic definition of both the pattern and the content. The printer driver then converts the content 7 and the pattern 6 to a format, such as a postscript file, suitable for the printer 202 , and sends it to the printer which prints the content 7 and the pattern 6 simultaneously in a one-pass process, i.e. on a single pass of the paper, on which the document is printed, through the printer.
[0040] In practice the various components of the system can be spread out over a local network or the internet. For example the pattern allocation module 212 can be provided on a separate internet connected server so that it can be accessed by a number of users.
[0041] While the use of a 1200 dpi printer is described above, a similar result can also be achieved with lower resolution printers, such as 600 dpi printers. For a 600 dpi printer, the approximate diameter if each ink dot is 42 μm. This is therefore still well below the minimum diameter for a dot that will be recognized by the pen 8 as a pattern dot. Therefore if the content is printed as single, spaced apart ink dots or pixels from a 600 dpi printer, and the pattern dots are printed as groups of ink dots, then the content and pattern can be printed simultaneously on a 600 dpi printer. Again the grey scale of the content dots needs to be kept at such a level that it will not interfere with the pens ability to identify the pattern dots. A maximum of about 30% grey has been found to work with the Logitec Io ™ pen.
[0042] If other methods of printing, such as offset printing are used, the resolution of the printed pattern and content can be much higher than with inkjet or laser jet printers. This gives greater freedom in the manner in which the content can be produced. FIG. 7 shows an example of a document in which the position identifying pattern is again provided by a set of pattern dots 300 , but the content is produced as a set of lines 302 , using the same ink as for the dots. The content lines 302 are much narrower than the pattern dots 300 and spaced apart by a distance equal to about four times their width. This means that they cover about 20% of the document surface. In this case the pattern dots are again about 100 μm in diameter and the content lines 302 are about 20 μm in width and spaced apart at a pitch of about 100 μm.
[0043] With the format of content and position identifying pattern described above, it is possible to use various image processing techniques within the pen processor 18 to help distinguish the content from the pattern, for a given resolution of the camera 12 in the pen 8 . Because the content dots 50 are smaller than, and closer together than, the pattern dots 30 , spatial filtering can be used to select, from all the marks on the document, those which make up the pattern dots 30 . Spatial filtering is typically carried out using Fourier transforms, for example as described in WO 01/75783. Referring to FIG. 8 , in a modification to the embodiment described above, the processor 18 is arranged to first receive, at step 300 , an image of a viewed area of the document 2 . Then at step 302 it performs a Fourier transform on the image which produces a map of the image in the spatial frequency domain. Next at step 304 , the elements of the spatial frequency domain map which correspond to the spatial frequency of the pattern 6 are selected, and the elements which correspond to the spatial frequency of the content dots 50 are removed using a low pass filtering process. At step 306 , the frequency domain map is transformed back to a new image, by reverse Fourier transform, to produce an image containing the pattern 6 but not the content 7 . The modified image is then analysed by the processor 18 in the normal way to determine the position of the pattern dots 30 at step 308 .
[0044] When this Fourier transform method is used, the ability of the processor 18 in the pen 8 to distinguish the pattern 6 from the content 7 is increased, so the content 7 can be made darker than that shown in FIG. 3 . For example the content shown in FIG. 4 could potentially be distinguished using this method. Also the lined content of FIG. 7 can more easily be distinguished using the Fourier transform method since the content lines only have a spatial frequency in one direction, and the method of removing them is therefore simplified.
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A method of generating an image comprising a position identifying pattern and a content feature comprises the steps of: generating the pattern and the content feature each as a plurality of graphical elements, and superimposing the content feature and the pattern. The content elements are smaller than the pattern elements in at least one dimension.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] A synchronous induced wind power generation system is provided, which is comprised of a rotatable turbine-generator section and a control system operable to rotate same in a direction corresponding to optimal wind conditions. In particular, a wind power generation system is provided having a turbine-generator section with a horizontally disposed rotating shaft therein connecting the turbine to the generator, orifices formed therein so as to optimally funnel wind over the turbines, turbine brakes to control the rotational speed of the turbines and the shaft power delivered to the generator, and a control system operable to orient the turbine-generator section with respect to the direction of the wind and generation of power via control of the turbine brakes and the synchronous generator.
[0003] 2. Description of the Related Art
[0004] Wind as an alternate motive force for generating electricity has long provided an attractive alternative to conventional power generation techniques. However, the effectiveness of conventional wind power generation systems have been limited by various difficulties such as, for example, the inconsistency of the wind, appropriate locations for placement of wind power generation system far from load centers and the problems of long distance transmission of power, difficulty in repair and maintenance of large systems, etc. These difficulties have inhibited large scale adoption of wind power as an alternate means of energy.
[0005] With regards to appropriate locations to place the systems, generally, wind power systems using turbines are developed, built and installed by large power companies, and are generally large units with very long turbine blades. The generator is mounted within a housing or nacelle that is positioned on top of a truss or tubular tower. The turbine blades transform wind energy into a rotational force or torque that drives a generator through a gearbox that steps the speed of the generator up to around 1200 RPM. The generators are DC generators, and produce DC power in proportion to the variable wind speed. The DC power is run through an inverter to get AC power, and the AC power is transmitted to the grid for later sale.
[0006] The power companies that install such wind turbines are generally interested only in systems capable of generating large amounts of power. Thus, most current wind turbines use large-sized blades (e.g., 60 meters or more in length). These large size blades result in an economy of scale. However, the longer blades require a supporting tower having a corresponding increased height and size.
[0007] Further, such large size blades prevent placement of conventional wind turbines within urban/suburban environments where the greatest demand for energy exists. Moreover, the large wind turbines are more subject to damage from high winds, as well as structural fatigue failures. Namely, the blades are subject to fatigue by encountering significantly higher wind loads at the top of the arc of rotation, followed a second later by lower velocity wind loads, which culminate at the bottom of the arc of rotation by a big thud as the blade passes the supporting column, where the flow of air is disrupted.
[0008] To minimize the chance that such conventional wind turbines are damaged by high winds, conventional wind turbines are frequently shut down when winds exceed a predetermined speed. And, the large blades frequently strike birds, resulting in conflict with environmental groups and government regulations.
[0009] In view of the deficiencies of conventional wind turbines discussed above, it is an object of the present invention to provide a wind driven electricity generating system that can be run safely and efficiently at 100% load regardless of higher wind speeds, that results in distributed power generation of many small wind generators inside load centers, that do not kill birds, that have no problem with blade failures, and that directly generate synchronous power.
[0010] It is a further object of the present invention to provide a wind driven electricity generating system which is structurally unobtrusive so as to be installable in urban/suburban environments close to the source of power consumption, thereby negating the need for expensive and inefficient transmission systems, which is not subject to damage from high winds while remaining at peak generation capacity (rather than shut down for protection), and which is not harmful to wildlife.
BRIEF SUMMARY OF THE INVENTION
[0011] In order to achieve the objects of the present invention, the present inventors endeavored to develop a synchronous induced wind power generation system capable of generating synchronous consistent power regardless of wind velocity or direction, and which may be installed in various locations, including urban and suburban environments. Accordingly, in a first embodiment of the present invention, a synchronous induced wind power generation system comprising:
[0012] (a) a turbine-generator section comprised of an outer shell having a first end, a second end opposite the first end, an interior area disposed therebetween, a first orifice disposed at the first end, a second orifice disposed at the second end, a horizontal wind flow axis extending from the first orifice to the second orifice, and an axis of rotation disposed perpendicular to the wind flow axis;
[0013] (b) one or more turbine/generator units disposed within the interior area of the turbine-generator section at or between the first orifice and second orifice, each of said turbine/generator units comprised of:
(i) one or more turbine blades disposed in a plane parallel or approximately parallel with the axis of rotation; (ii) one or more directrix blades disposed in a plane parallel or approximately parallel with the axis of rotation; (iii) a rotatable shaft having a first end and a second end, the first end of the shaft in connection with the turbine blades; (iv) a synchronous generator in connection with the second end of the rotatable shaft; and (v) one or more turbine brakes disposed on or adjacent to the turbine blades;
[0019] (c) a direction orientation means in communication with the turbine-generator section at or adjacent to the axis of rotation, said direction orientation means operable to controllably rotate the turbine/generator section about the axis of rotation so as to control the orientation of the turbine-generator section relative to the direction of the wind; and
[0020] (d) a control system in conductive communication with each synchronous generator so as to be operable to synchronize the frequency and the voltage phase of the generator with the voltage phase of an external AC power line in conductive communication with the synchronous generator, in conductive or mechanical communication with the direction orientation means so as to be operable to control a position of the turbine/generator section relative to wind direction, and in conductive or mechanical communication with the turbine brakes so as to be operable to control the speed of rotation with no load, or maximum torque during synchronous operation of the turbine, thereby controlling shaft power delivered to the generator, said control system comprised of:
(i) a computer processor; (ii) one or more of a phase sensor and speed sensor in connection with the computer processor and each of the turbine/generator units; (iii) one or more of an anemometer and a wind direction detector (wind vane) in communication with the computer processor; (iv) one or more differential pressure sensors operable to determine fine wind direction in communication with the computer processor.
[0025] In a preferred embodiment, the synchronous induced wind power generation of the first embodiment above is provided, wherein the area of the turbine-generator section adjacent the first orifice and the second orifice of larger than the area of the turbine-generator section adjacent the interior area, so as to funnel wind into the turbine-generator section. More preferably, the area of the turbine-generator section adjacent the first orifice and the second orifice is 1.1 to 12 times larger than the area of the turbine-generator section adjacent the interior area. Even more preferably, the area of the turbine-generator section adjacent the first orifice and the second orifice is 5 to 8 times larger than the area of the turbine-generator section adjacent the interior area. Most preferably, the area of the turbine-generator section adjacent the first orifice and the second orifice is about 8 times larger than the area of the turbine-generator section adjacent the interior area.
[0026] In a further preferred embodiment, the synchronous induced wind power generation of the first embodiment above is provided, further comprising a computer program product (computer software application) for managing operation of the wind power generation system. This computer program product is comprised of computer usable program code operable to enable the computer processor to communicate with one or more of the various sensors, synchronize frequency and voltage phase of the generator units with the voltage phase of an external power line in communication with the system, monitor and adjust the orientation of the turbine-generator section relative to the wind flow axis, via control of the direction-orientation means. Further, the computer usable program code is operable to control the turbine brakes so as to control and monitor the speed of rotation of the turbine, especially during initial synchronization with the power line and during loss of load, when the load is suddenly removed and the magnetic brakes must supply braking action equivalent to 100% of the generator's output at the instant that the load is lost and attempt to maintain the phase of the line in case the load returns a few seconds later.
[0027] In another preferred embodiment, the synchronous induced wind power generation of the first embodiment above is provided, further comprising one or more controllable, pivotable air bypass doors disposed in or adjacent to the first end and second end of the outer shell of the turbine/generator units, which may be operated in such a manner as to reduce excess air flow through the turbine-generator unit.
[0028] Additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The aspects of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0029] FIG. 1 is a perspective view of the synchronous induced wind power generation system of the present invention.
[0030] FIG. 2 is a side view of the synchronous induced wind power generation system of the present invention.
[0031] FIG. 3 is a partial cross-sectional view of the synchronous induced wind power generation system of the present invention, illustrating the internal configuration of the turbine-generator section having the turbine-generator disposed therein.
[0032] FIG. 4 is a partial cross-sectional view of the synchronous induced wind power generation system of the present invention, illustrating one preferred disposition of the turbine-generator unit, turbine brakes relative to the turbines, fixed directrix blading and pivotable air bypass doors within the turbine-generator section.
[0033] FIG. 5 is a box diagram illustrating the connectivity of the various components of the control system of the system of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0034] As illustrated in FIGS. 1-3 , the present invention provides a synchronous induced wind power generation system 1 comprised generally of a turbine-generator section 3 , a turbine-generator unit 21 disposed therein, a direction orientation means 45 in movable connection with the turbine-generator section 3 , and a control system 33 operable to control the entire system 1 based on, for example, wind velocity, wind direction, external load characteristics, power requirements, etc.
[0035] Specifically, as shown in FIGS. 1 and 2 , the turbine-generator section 3 is comprised of an outer shell 5 having a first end 7 , a second end 9 opposite the first end 7 , and an interior area 11 disposed there between. A first orifice 13 is disposed at the first end 7 , a second orifice 15 is disposed at the second end 9 , a wind flow axis 17 extends from the first orifice 13 to the second orifice, and an axis of rotation 19 disposed perpendicular to the wind flow axis 17 . The turbine-generator section 3 may be formed in any shape, such as conical, square or rectangular shape, a variation thereof, as well as two or more of same.
[0036] In a preferred embodiment, as illustrated in FIGS. 1 and 2 , the area of the turbine-generator section 3 adjacent the first orifice 13 and the second orifice 15 are larger than the area of the turbine-generator section 3 adjacent the interior area 11 so as to funnel wind into the turbine-generator section, thereby increasing wind flow through the turbine-generator section 3 and allowing power generation in relatively light wind velocity. Preferably, the area of the turbine-generator section adjacent the first orifice 13 and the second orifice 15 is 1.1 to 12 times larger than the area of the turbine-generator section 3 adjacent the interior area 11 , more preferably, 5 to 8 times larger than the area of the turbine-generator section 3 adjacent the interior area 11 , most preferably about 8 times larger than the area of the turbine-generator section 3 adjacent the interior area 11 .
[0037] By forming the turbine-generator section with orifices having a wider diameter (area) than the interior area 11 of section 3 , two coaxial “funnels” are formed. Thus, wind that is blowing horizontal to the ground can blow through one end of the turbine-generator section 3 and exit out the other end. The exit end induces a negative pressure from the wind blowing past it. The upwind end forms a positive pressure from the wind blowing against it. The differential pressure between the two causes a substantial increase in wind velocity through the interior area 11 of the turbine-generator section 3 , and hence an increased wind velocity over the turbine blades 23 disposed therein.
[0038] Specifically, as shown in FIGS. 3 and 4 , the turbine/generator unit(s) 21 is disposed within the interior area 11 of the turbine-generator section 3 at or between the first orifice 13 and the second orifice 15 . The turbine/generator unit(s) 13 is comprised of one or more turbine blades 23 , a rotatable shaft 25 in connection therewith, and a synchronous generator 31 in connection with the rotatable shaft 25 opposite the turbine blades 23 . Preferably, the turbine blades 23 are disposed in a plane parallel or approximately parallel with the axis of rotation 19 .
[0039] As illustrated in 4 , one or more turbine brakes are disposed on or adjacent to the turbine blades. The turbine brakes, which are in communication with the control system 33 so as be operated thereby, are comprised of metallic brake discs 47 and turbine brake electromagnets 49 operable to induce magnetic lines of flux perpendicular to the horizontal axis of the metallic brake discs 47 , so as to induce braking action in the metallic brake discs. This orientation allows precise control of the turbine velocity without use of high maintenance, moving parts. Further, the turbine brakes, which are in conductive or mechanical communication with the control system 33 , are used to control the speed of rotation with no load, or torque during synchronous operation of the turbine generator unit 21 , thereby controlling shaft power delivered to the synchronous generator 31 .
[0040] To maximize power generation, the wind flow axis 17 of the turbine-generator section 3 should be brought into an approximately parallel orientation with respect to current wind flow. If wind speed increases turbine shaft power above 100% and below about 150% of the generator's power rating, the magnetic brakes are employed to keep the generator at 100% loading. If the wind speed increases turbine power above about 150% of the generator's power rating, the pivotable air bypass doors 53 can be opened as needed to keep turbine power around 150%, with the magnetic brakes absorbing the excess power above 100% of the generator's power rating.
[0041] Further, if wind speed increases to a level capable of damaging the turbine-generator unit, a means for rotating the turbine-generator section 3 away from the wind to decrease air flow through the turbine-generator section 3 is desirable. To provide such a means, a direction orientation means 45 , as shown in FIGS. 1-3 , is provided in communication with the turbine-generator section 3 at or adjacent to the axis of rotation 19 . The direction orientation means 45 is operable to controllably rotate the entire turbine/generator section 3 about the axis of rotation 19 , so as to control the orientation of the turbine-generator section relative to the direction of the wind.
[0042] The direction orientation means 45 may be comprised of any conventional means of rotating a structure about an axis. In a preferred embodiment, the direction orientation means 45 is comprised of an electric, pneumatic or hydraulic motor in connection with shaft. As illustrated in FIGS. 1 and 2 , the shaft 46 has a first end and a second end, the first end of the shaft 46 being in rotatable communication with the motor means 48 , and the second end of the shaft 46 being affixed to the turbine-generator section 3 . The motor means 48 is in communication, via one or more of a conductive, mechanical or fluid connection, depending on the type of motor used, with the control system 33 , such that the control system may actuate the motor means so as to rotate the turbine-generation section 3 to a desired position with respect to wind flow.
[0043] As mentioned above, and as illustrated in FIGS. 3 and 5 , a control system 33 is provided in conductive communication with each synchronous generator 31 so as to be operable to synchronize the frequency and the voltage phase of the generator with the voltage phase of an external AC power line 61 in conductive communication with the synchronous generator. In a preferred embodiment, a voltage regulator 63 is provided in communication with the computer processor. Preferably, the wind turbines are set to rotate at a one fixed (predetermined) speed when generating electrical power. This one fixed operating speed is mainly dependent on turbine diameter. The fixed turbine operating speed determines the number of poles required for the generator to produce 60 hertz power. For example, a 450 RPM turbine requires a 16-pole synchronous generator to produce 60 hertz power, and the 450 RPM speed equates to a turbine tip speed of 471 feet per second for a 10-foot diameter turbine, which facilitates the operation of the magnetic brakes.
[0044] The ability to choose a generator to match the speed of the turbine desirably allows for direct drive, rather than a geared drive, thereby simplifying the design and minimizing the cost of construction. The turbine is designed to optimize energy transfer at some fixed speed. The synchronous generator 31 runs synchronized with the power line when operating, and generates 60 hertz AC power (for US applications) at any power factor desired, such that the AC output voltage can be regulated by controlling the field current in the generators. Thus, the synchronous generator 31 of the present invention can produce VARS to create any Power Factor within the operating range of the generator.
[0045] During start-up, the magnetic brakes are used to absorb all turbine power until about 10% power is achieved while holding the turbine speed at approximately the synchronous speed of the generator. Then, the exciter is energized to cause AC voltage output of the generator to match the voltage of the outside electrical grid (via an external AC line). The magnetic brakes are used to adjust the phase of the generator to the phase of the line, then the unit breaker is closed to connect the synchronous generator 31 to the power grid. The magnetic brakes are then released, allowing the 10% or so power that was being absorbed by the magnetic brakes to reach the generator. If the generator power falls below about 1%, the unit breaker is opened and the magnetic brakes resume controlling the maximum speed of the turbine.
[0046] The control system 33 is comprised of a computer processor 35 . The computer processor 35 may be any conventional computer, such as a desktop computer, a laptop computer, or any computing mechanism that performs operations via a microprocessor, which is a programmable digital electronic component that incorporates the functions of a central processing unit (CPU) on a single semi-conducting integrated circuit (IC). One or more microprocessors typically serve as the CPU in a computer system, embedded system, or handheld device.
[0047] A data processing system suitable for storing and/or executing program code will include at least one processor coupled directly or indirectly to memory elements through a system bus. The memory elements can include local memory employed during actual execution of the program code, bulk storage, and cache memories which provide temporary storage of at least some program code in order to reduce the number of times code must be retrieved from bulk storage during execution. Input/output or I/O devices (including but not limited to keyboards, displays, pointing devices, etc.) can be coupled to the system either directly or through intervening I/O controllers. Network adapters may also be coupled to the system to enable the data processing system to become coupled to other data processing systems or remote printers or storage devices through intervening private or public networks. Modems, cable modem and Ethernet cards are just a few of the currently available types of network adapters.
[0048] The control system 33 is further comprised of one or more of a phase sensor 37 and speed sensor 38 , both of which are in connection with the computer processor 35 and each of the synchronous generators 31 . The phase sensor 37 and speed sensor 38 are preferably one or more of an optical sensor, mechanical sensor, or magnetic sensor. Further, as illustrated in FIGS. 1 and 2 , one or more of an anemometer 39 and a wind direction detector (wind vane) 41 is provided in communication with the computer processor 35 . In addition, in a preferred embodiment, one or more differential pressure sensors 65 is provided in communication with the computer processor 35 to determine fine wind direction.
[0049] The anemometer 39 and a wind direction detector (wind vane) 41 are preferably disposed on or adjacent to the turbine-generator section 3 . The phase sensor 37 , which is operable to sense the phase and speed of rotation of the shaft 25 , is disposed on, adjacent to, or in connection with the rotatable shaft 25 of each of the turbine-generator units 21 , said phase sensor. Data is recorded by each of these sensors/detectors, and fed to the computer processor 35 for use/analysis by the control system 33 in determining proper operating parameters of the system 1 .
[0050] As illustrated in FIG. 4 , in a preferred embodiment, two or more fixed directrix blades 51 are disposed adjacent to and upwind of the wind turbine 21 at one end thereof, and attached to the turbine-generator section 3 at an opposite end thereof, and may also support the turbine generator unit 21 within the interior area 11 of the turbine-generator section 3 . However, the fixed directrix blading, which perform the function of directing air flow and/or supporting the integrity of the turbine-generator section 3 , may be alternately or additionally disposed forward of the turbine blades 23 , between the blades 23 and first orifice 13 , or rearward of the blades 23 , between synchronous generator 31 and the second orifice 15 . Further, alternatively, the fixed directrix blades 51 may be disposed in the orifices 13 and 15 .
[0051] In a further preferred embodiment, as illustrated in FIG. 4 , one or more pivotable air bypass doors 53 , as mentioned above, are disposed in or adjacent to the first end 7 and/or second end 9 of the outer shell 5 of the turbine/generator section 3 . These doors 53 , which are in communication with the control system 33 via mechanical, electrical or hydraulic means, may be opened proportionally to shunt air around the wind turbine during high ambient wind conditions. In particular, when the control system 33 determines that air flow through the turbine-generator section 3 has exceeded a predetermined desirable level, the pivotable air bypass doors 53 may be fully or partially opened to limit excess air flow through the turbine-generator unit 21 .
[0052] The synchronous induced wind power generation system 1 of the present invention further comprises a computer program product for managing operation of the wind power generation system, and method of operating the wind power generation system via use of same. The computer program product is stored on a computer-usable or computer readable medium which may be any apparatus that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. The medium can be an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system (or apparatus or device) or a propagation medium. Examples of a computer-readable medium include a semiconductor or solid state memory, a removable FLASH memory medium, a random access memory (RAM), a read-only memory (ROM), a rigid magnetic disk and an optical disk. Current examples of optical disks include compact disk—read only memory (CD-ROM), compact disk—read/write (CD-R/W) and DVD.
[0053] The computer usable medium has computer usable program code embodied thereon, the computer usable program code comprising various code operable to control the operation of the system 1 . In particular, in a first embodiment, the computer usable program code is operable to enable the computer processor to communicate with one or more of the anemometer, wind direction detector, differential pressure sensor, and phase sensors, so as to receive and store data therefrom. Further, computer usable program code is operable to enable the control system 33 to synchronize frequency and voltage phase of the synchronous generator 31 with the voltage phase of an external AC power line 61 in communication with the system 1 .
[0054] In a further preferred embodiment, the computer program of the present invention is further operable to control the magnetic brakes to modulate shaft power delivered to the generator(s) units during wind transients, so as to prevent instantaneous overloads of the generator units, to control the speed of the generator units during loss of external electrical load of the generator units via application of the magnetic brakes and rotation of the turbine/generator section relative to the direction of the wind, to control voltage of the generator units during normal operation and at a moment of loss of external electrical load of the generator units, and to monitor and redirect mechanical loads of greater than 150% of full generator power from the wind turbines after loss of external electrical load of the generator units to the generator units as shaft power, so as to maintain the turbines at full speed until the external electrical load is restored, thereby allowing the generator to recover full power after short line load interruptions in very short time periods.
[0055] Thus, the computer program product provide the following general functionality:
[0056] (1) communication of the computer processor with one or more of the various sensors;
[0057] (2) synchronization of the frequency and voltage phase of the generator units with the voltage phase of an external power line in communication with the system;
[0058] (3) monitoring and adjustment of the orientation of the turbine-generator section relative to the wind flow axis, via computer control of the direction-orientation means; and
[0059] (4) electrical control of the turbine brakes so as to control and monitor the speed of rotation of the turbine.
[0060] Further, the computer program is operable to monitor and adjust the orientation of the turbine-generator section relative to the wind flow axis, via control of the direction-orientation means, so as to maintain a maximum amount of air flow through the turbine-generator section. In addition, as mentioned above, the computer usable program code is operable to enable the control system 33 to control operation of the turbine brakes.
[0061] In another preferred embodiment, computer program is also operable to enable the control system 33 to control operation (opening and closing) of the pivotable air bypass doors 53 .
[0062] Although specific embodiments of the invention have been disclosed, those having ordinary skill in the art will understand that changes can be made to the specific embodiments without departing from the spirit and scope of the invention. The scope of the invention is not to be restricted, therefore, to the specific embodiments. Furthermore, it is intended that the appended claims cover any and all such applications, modifications, and embodiments within the scope of the present invention.
LIST OF DRAWING ELEMENTS
[0000]
1 : synchronous induced wind power generation system
3 : turbine-generator section
5 : outer shell of turbine-generator section
7 : first end of turbine-generator section
9 : second end of turbine-generator section
11 : interior area of turbine-generator section
13 : first orifice
15 : second orifice
17 : wind flow axis
19 : axis or rotation
21 : turbine/generator unit
23 : turbine blades
25 : rotatable shaft
31 : synchronous generator
33 : control system
35 : computer processor
37 : phase sensor
38 : speed sensor
39 : anemometer
41 : wind direction detector (wind vane)
45 : direction orientation means
46 : shaft of direction orientation means
47 : metallic brake discs
48 : motor means
49 : turbine brake electromagnets
51 : fixed directrix blade
53 : pivotable air bypass door
61 : external AC line
63 : voltage regulator
65 : differential pressure sensor
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A synchronous induced wind power generation system is provided, which is comprised of a rotatable turbine-generator section and a control system operable to rotate same in a direction corresponding to optimal wind conditions. The turbine-generator section has a horizontally disposed turbine therein in an interior area thereof, and orifices formed at either end thereof, with wider areas than the interior area, so as to form a funnel-like shape at either of the turbine-generator section. These funnel-shaped sections optimally funnel wind to the turbine, which is connected to a synchronous generator that runs at synchronous speed with an external power line in connection therewith. Further, turbine brakes are employed to modulate turbine power and speed, and the control system is operable to orient the turbine-generator section with respect to the direction of the wind and generation of power via control of the turbines and synchronous generator, and via receipt of sensor/detector data received from a plurality of sensors/detectors in communication therewith.
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RELATED APPLICATIONS
[0001] This continuation application claims priority to and the benefit of U.S. patent application Ser. No. 14/160,849 filed on Jan. 22, 2014 which claims priority to and the benefit of U.S. Patent Application Ser. No. 61/759,750 filed on Feb. 1, 2013, both of which are incorporated by reference in their entirety.
BACKGROUND OF THE INVENTION
[0002] Four wheel drive for vehicles can be advantageous in certain circumstances, like when additional traction is needed because of surface conditions, or during cornering or acceleration. Driving all four of the wheels and their associated components, however, is not often required during most driving conditions and it results in increased fuel consumption.
[0003] It is preferable that two of the four wheels be selectively engaged only when required at least to avoid the increase in fuel consumption. It is known to directly drive two wheels of a vehicle and then to use a power take off unit to selectively drive the other two wheels. Typically, a shift fork and a sliding clutch, among other components, are used to selectively engage and disengage the rear wheels at the power take off unit.
[0004] One embodiment of a prior art shift fork 10 and sliding clutch 12 is depicted in FIG. 1 . The shift fork 10 is moved in the axial direction by a linear push rod or piston 14 . The shift fork 10 is connected to the sliding clutch 12 . The sliding clutch 12 slides on, and rotates with, a source of rotation. In the depicted in embodiment, the sliding clutch 12 is mounted for axial movement on a ring gear 16 . The ring gear 16 is driven by a shaft 18 .
[0005] The clutch 12 has a set of teeth 20 on one of its side surfaces. The shift fork 10 selectively moves the sliding clutch 12 , and its teeth 20 , axially into and out of engagement with a set of teeth 22 on an adjacent shaft 24 . The shaft 24 is connected to a drive shaft 26 , such as an axle half shaft. As shown in the figures, the adjacent shaft 24 is concentric about the drive shaft 26 .
[0006] The above-described system has a number of drawbacks. First, it requires a large amount of space for the sliding clutch 12 to be translated in the axial direction. Second, it requires a relatively large and powerful device to move the entire fork 10 and the entire clutch 12 . Third, because the clutch 12 is moved, the shift fork 10 and other components must be robust, and thus heavy, to withstand the repeated loading and unloading. Fourth, the response time for the clutch 12 to be engaged or disengaged is slow often because of the large amount of time needed for the shift fork 10 to axially move the clutch 12 adequately for engagement or disengagement with the adjacent set of teeth 22 .
SUMMARY OF THE INVENTION
[0007] A shifting mechanism and method of using the shifting mechanism are described. The shifting mechanism has a shift fork with a lower arm, an upright portion and an upper arm. An upper flange and a lower flange located on an outer surface of the upright portion. A first pin aperture is located in the upper flange and a second pin aperture is located in the lower flange. A first block pin is located within the first pin aperture and a second block pin is located within the second pin aperture. A block is provided on which the first block pin and the second block pin are attached. The block has internal threads. A screw gear is engaged with the block internal threads and the screw gear is connected to a shift motor.
BRIEF DESCRIPTION OF THE FIGURES
[0008] The above will become readily apparent to those skilled in the art from the following detailed description when considered in the light of the accompanying drawings in which:
[0009] FIG. 1 is one embodiment of a prior art shift mechanism;
[0010] FIG. 2 is a schematic of a vehicle driveline;
[0011] FIG. 3 is a side view of one embodiment of the invention;
[0012] FIG. 4 is a perspective view of the invention of FIG. 3 ;
[0013] FIG. 5 is a top view of the invention of FIG. 3 ;
[0014] FIG. 6 is a detail view of the invention of FIG. 3 ;
[0015] FIG. 7 is a partial cross-section side view of another embodiment; and
[0016] FIG. 8 is a perspective view of the embodiment of FIG. 7
DETAILED DESCRIPTION OF THE INVENTION
[0017] It is to be understood that the invention may assume various alternative orientations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions, directions or other physical characteristics relating to the embodiments disclosed are not to be considered as limiting, unless the claims expressly state otherwise.
[0018] FIG. 2 schematically depicts a drivetrain 28 of an all-wheel drive (AWD) or four-wheel-drive (4WD) motor vehicle. The AWD drivetrain 28 comprises a pair of front drive wheels 30 and 32 , a pair of rear drive wheels 34 and 36 and a front-wheel-drive (FWD) transaxle unit 38 . The FWD transaxle unit 38 is operatively connected to a prime mover 40 , such as an internal combustion engine, electric motor, etc.
[0019] The FWD transaxle unit 38 is a drive setup in which a power transmission 42 , a final drive, and a front differential assembly 44 are combined into a single unit connected directly to the prime mover 40 ; these components do not have to be in a single unit. The FWD transaxles are commonly used in front wheel drive motor vehicles. The power transmission 42 is commonly known in the art as a mechanical unit containing a manual or automatic change-speed gear system and associated actuating machinery. An output from the power transmission 42 is connected to the front differential assembly 44 through the final drive. The front differential assembly 44 is drivingly connected to right-hand and left-hand front output axle shafts 46 and 48 , respectively. In turn, the output axle shafts 46 and 48 drive the front wheels 30 and 32 , through suitable coupling means, such as constant-velocity joints (not shown).
[0020] As illustrated, the FWD transaxle unit 38 further includes an integrated torque-coupling device 50 and power take-off unit (PTU) 52 . The torque-coupling device 50 is provided for selectively restricting differential rotation of the front differential assembly 44 , i.e. of the output axle shafts 46 and 48 , and the PTU 52 is adapted for use in a full-time AWD system and is operable to transfer drive torque from the prime mover 40 and the power transmission 42 at a predetermined distribution ratio to the rear wheels 34 , 36 of a rear drive axle 54 through a propeller shaft 56 , a rear differential assembly 58 and rear axle shafts 60 and 62 .
[0021] Although, the preferred embodiment of the present invention is described with the reference to the front-wheel-drive transaxle unit, it will be appreciated that the present invention is equally applicable to a rear-wheel-drive transaxle unit. The components described below may also be adapted to any other known power take off units for vehicles or other machinery.
[0022] FIGS. 3-6 depict one embodiment of a PTU 52 . An input shaft 64 , rotationally driven by the transmission 42 , is depicted. The input shaft 64 drives a pinion gear (not shown), which is in meshed engagement with a ring gear (not shown). In a preferred embodiment, the ring and pinion gears are in a hypoid arrangement, but other connections between the ring and pinion gears are permissible. The pinion gear and ring gear are located within a power-take-off unit housing 66 .
[0023] The ring gear is connected to a power take off output shaft 68 . The power take off output shaft 68 is oriented substantially transversely to the input shaft 64 in the depicted embodiment. The ring and pinion gears transfer rotational power coming from the input shaft 64 , which is aligned along a first axis 70 , to the power take off output shaft 68 , which is perpendicular to the input shaft 64 , and aligned along a second axis 72 .
[0024] A shift motor 74 is located within the power take off housing 66 . The motor 74 may be an electric motor, but pneumatic, hydraulic, mechanical and/or magnetic sources may also be used. In the depicted embodiment, an electric motor is provided and oriented along an axis 76 . The motor axis 76 is perpendicular to the input shaft axis 70 and power take off output shaft axis 72 . The motor 74 may also be located outside of the power take off housing 66 .
[0025] An output shaft 78 , connected to the motor 74 , extends through an output end of the motor 74 . The shaft 78 is aligned with the motor axis 76 . A gear 80 is secured to the shaft 78 for rotation therewith.
[0026] The motor 74 may be adapted to turn in both a clockwise and a counterclockwise direction. A controller (not shown) signals the motor 74 when to turn and in what direction the motor 74 should turn in. The controller may be such an electronic controller connected to the motor 74 .
[0027] The motor gear 80 is part of a reduction gear system 82 that also comprises a first intermediate gear 84 . The motor gear 80 is in meshed engagement with the first intermediate gear 84 .
[0028] The first intermediate gear 84 may be larger in diameter than the motor gear 80 . The increased diameter size of the first intermediate gear 84 compared with the motor gear 80 results in a reduction in the revolutions per minute of the first intermediate gear 84 compared with the motor gear 80 .
[0029] The first intermediate gear 84 is mounted for rotation within the power take off housing 66 . The first intermediate gear 84 rotates about an axis 86 that is parallel to the axis 76 of the motor 74 .
[0030] The reduction gear system 82 also comprises a second intermediate gear 88 . The second intermediate gear 88 rotates about the same axis 86 as the first intermediate gear 84 . The second intermediate gear 88 may be located above the first intermediate gear 84 . The first and second intermediate gears 84 , 88 may be mounted to one another or they may be separate. If the gears 84 , 88 are separate a means for one to drive the other is preferred.
[0031] The second intermediate gear 88 may have an outer diameter that is reduced compared to the first intermediate gear 84 . Therefore, the number of revolutions per minute of the second intermediate gear 88 compared with the first intermediate gear 84 is increased.
[0032] The gear reduction system 82 may be comprised of greater or fewer gears than depicted in the figure, and of the gears selected, the sizes and number or type of teeth may vary from what is shown.
[0033] A lever arm 90 is provided with a first end portion 92 and a second end portion 94 . The first end portion 92 terminates in an edge 96 . Preferably, the edge 96 is curvilinear; most preferably, it is arc-shaped. The width of the edge 96 may be greater than the diameter of the second intermediate gear 88 , as shown in the Figures. The width of the edge 96 may be less than, equal to or greater than the diameter of the first intermediate gear 84 . The thickness of the edge 96 may be approximately that of the second intermediate gear 88 .
[0034] A plurality of teeth 98 may define the lever arm edge 96 . The teeth 98 are directly engaged with teeth 100 on the second intermediate gear 88 .
[0035] The lever arm first end portion 92 extends to the second end portion 94 in a bar-like fashion. The second end portion 94 is unitary, one-piece and integrally formed with a shift fork 102 . The shift-fork 102 comprises a C-shaped portion 104 where one of the legs of the C is elongated and comprises the lever arm.
[0036] The shift fork 102 thus comprises the lever arm as a lower leg 106 , an upwardly extending portion 108 and an upper leg 110 all of which are unitary, one-piece and integrally formed with one another. The shift fork 102 also comprises an inner hemispherical surface 112 , which partially defines the C-shape 104 of the fork 102 .
[0037] While terms like “upper,” “lower,” and “upwardly” are used with certain elements above, these terms are not intended to be limiting since the shift fork 102 can be located in any orientation. The terms are merely used for clarification of the shift fork elements depicted in one orientation in the figures.
[0038] At least one shift fork peg is provided in the shift fork 102 . Preferably, two shift fork pegs are utilized. A first peg 114 is located in the upper leg 110 of the shift fork 102 and a second peg 116 is located in the lower leg 106 of the shift fork 102 . The pegs 114 , 116 are preferably axially aligned with one another, as shown in FIG. 3 .
[0039] The pegs 114 , 116 extend through the shift fork 102 and into a groove 118 of a clutch collar 120 . The groove 118 may be circumferential, or only partially circumferential, about the collar 120 . Preferably, the inner hemispherical surface 112 of the shift fork 102 is complimentary to an outer surface 122 of the clutch collar 120 . The outer surface 122 defines the groove 118 . Thus, it can be appreciated that, at least partially, the shift fork 102 is externally concentric with the clutch collar 120 .
[0040] Internally concentric with the clutch collar is a hub structure 124 that locates the collar 120 on to the power take off shaft 68 . The hub structure 124 permits the collar 120 to selectively move axially along the power take off shaft 68 . The hub structure 124 may be comprised of a splined connection between the hub structure 124 and the shaft 68 , or the structure may be comprised of smooth engagement surfaces between the hub structure 124 and the shaft 68 that permit the collar 120 to move along the shaft 68 .
[0041] The clutch collar 120 is connected to a synchronizer (not shown). Synchronizers are used for matching, or synchronizing, the rotation of two parts that might rotating at different rates, or where one part is rotating and the other is not.
[0042] In one embodiment, the synchronizer may be such as a cone synchronizer. A cone synchronizer generally comprises two parts: a selectively rotatable cone-shaped structure, such as a ring, and a complimentary shaped structure. The cone structure may be moved selectively into and out of engagement with the complimentary shaped structure, or vice versa.
[0043] It can be appreciated that, for example, if the cone structure is rotating and the complimentary structure is not, as the cone structure is introduced into the complimentary structure, the complimentary structure begins to rotate. As the cone structure is introduced more and more into the complimentary structure, the complimentary structure begins to rotate closer to the speed of the cone structure. If the rotation of the complimentary structure is to be reduced, the cone structure is gradually withdrawn in the same fashion.
[0044] The clutch collar 120 may be connected to either the cone structure or the complimentary shaped structure. Thus, it can be appreciated that the clutch collar 120 and the power take off shaft 68 can be selectively engaged and disengaged from the power take off unit 52 for engagement and disengagement of drive for the rear wheels.
[0045] The vehicle on which the power take off unit 52 is located has various sensors, programmed software and computers (not shown) to determine when the power take off unit 52 should transfer power to the rear drive wheels 34 , 36 . In some cases, the operator of the vehicle may make the determination when the rear wheels 34 , 36 should be engaged so that vehicle operates in four wheel drive.
[0046] Engaging the rear wheels 34 , 36 begins with the shift motor 74 receiving a signal to rotate the motor gear 80 . The gear 80 rotates causing the first and second intermediate gears 84 , 88 to also rotate. The second intermediate gear 88 drives through the arc-shaped toothed surface of the lever arm 90 . The lever arm 90 pivots in response to the movement of the second intermediate gear 88 . The lever arm 90 pivots about a pivot axis 126 located through the arm 90 . The pivot axis 126 is parallel to the motor axis 76 and transverse to the input shaft axis 72 and the second axis 76 .
[0047] The lever arm edge 96 moves along an arc 128 as best seen in FIGS. 5 and 6 . The lever arm pivot point/axis 126 can also be more clearly appreciated in FIG. 5 .
[0048] The pivot action of the lever arm 90 and the shift fork 10 axially slides the clutch collar 120 to engage the synchronizer. Rotation transfers through the synchronizer resulting in the rotation of the power take off output shaft 68 .
[0049] Disconnecting the drive to the rear wheels 34 , 36 begins with the shift motor 74 receiving a signal to rotate in the opposite direction. The motor gear 80 rotates in the second direction, which rotates the first and second intermediate gears 84 , 88 . The second intermediate gear 88 drives back across the arc-shaped toothed edge 92 of the lever arm 90 . The clutch collar 120 pivots about the pivot axis away from the synchronizer, thus disengaging the drive.
[0050] Based on the foregoing, it can be appreciated that the amount of space required to accommodate the lever arm 90 , the clutch collar 120 and the movement of both is reduced compared with prior art designs. Additionally, it can be appreciated that because the entire clutch collar 120 does not have to be axially moved, but just a portion has to be pivoted, that the size of the motor required to do the moving can be reduced. Further, the lever arm 90 provides a mechanical advantage that the prior art designs did not have to move the clutch collar 120 . The motor 74 , and the other components, may therefore be smaller and lighter weight than the prior designs. Lastly, because the lever arm 90 accentuates the movement received by the reduction gears 84 , 88 , the clutch collar 120 is moved relatively quickly into and out of position resulting a fast clutch engagement and disengagement.
[0051] FIGS. 7 and 8 depict an alternative embodiment wherein the shift motor 74 ′ is oriented parallel and planar with the power take off output shaft 68 ′. The shift motor 74 ′ drives a screw-type gear 130 that extends axially with the shift motor 74 ′. The screw-type gear 130 extends through a block 132 .
[0052] The block 132 has internal threads complementary to the gear 130 . The combined screw-type gear 130 and threaded block 132 create a worm gear. The complementary threads of the worm gear effectively lock together when the motor 74 ′ stops turning. This has the advantage of holding the gear 130 with respect to the block 132 in a fixed position, thus the shift fork 102 ′ is also locked in position.
[0053] The block 132 is connected to shift fork 102 ′. In the depicted embodiment, the block 132 has at least one pin extending transversely to the motor axis. Preferably, two pins 134 , 136 , which are axially aligned with one another, are located within flanges 138 on the shift fork 102 ′. The pins are connected to the block. The flanges 138 extend from an outer surface 140 of the shift fork 102 ′. There may be an upper flange and a lower flange. The upper and lower flanges 138 extend opposite the lower arm and the upper arm but the flanges 138 are parallel the arms and the flanges 138 are parallel one another.
[0054] The flanges 138 define pin apertures 142 for receiving the block pins 134 , 136 therein. There may be a first pin aperture and a second pin aperture in the first and second flanges, respectively. Preferably, the first pin aperture is aligned with the second pin aperture. The block pins 134 , 136 are free to rotate within the pin apertures 142 . The block pins 134 , 136 extend opposite one another from the block. The shift fork 102 ′ utilizes the pins 134 described above to connect with the clutch collar 120 ′.
[0055] It can be appreciated that upon rotation of the screw-type gear 130 in a first direction, the block 132 is moved away from the motor 74 ′. The clutch 120 follows the block 132 resulting in the collar 120 ′ moving away from the synchronizer. The synchronizer is thus disengaged. The collar 120 ′ pivots about a pivot point 144 , which is opposite the flanges 138 . The arc 146 traveled by the flanges 138 can be appreciated by FIG. 7 . Upon rotation of the screw-type gear 130 in a second opposite direction, the block 132 is moved toward the motor 74 . The clutch collar 120 ′ follows the block 132 resulting in the collar 120 ′ moving toward the synchronizer. The synchronizer is thus engaged. The flanges 138 travel along the same arc 128 and pivot about the same pivot point 144 .
[0056] The connection of the block 132 and collar 120 ′ creates a lever arm, thus providing a mechanical advantage for moving the clutch collar 120 ′. The mechanical advantage provided by the lever arm means that the motor 74 ′ does not have to be as large to move the clutch collar 120 ′ compared with prior art designs. The space reduction means that the entire system can be located in a smaller envelope. The space reduction and small motor translate to lighter weight. Lastly, because the lever arm accentuates the movement received by motor 74 ′, the clutch collar 120 ′ is moved relatively quickly into and out of position resulting a fast clutch engagement and disengagement.
[0057] In accordance with the provisions of the patent statutes, the principles and modes of operation of this invention have been described and illustrated in its preferred embodiments. However, it must be understood that the invention may be practiced otherwise than specifically explained and illustrated without departing from its spirit or scope.
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A shifting mechanism and method of using the shift mechanism is described. The shifting mechanism has a shift fork. Flanges are connected to a portion of the shift fork. Pin apertures in the flanges receive pins therein. The pins are connected to a block, which receives a screw gear therein. The screw gear is connected to a shift motor.
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DESCRIPTION
The invention relates to a control apparatus for a material flow emitted by a vacuum heated evaporation source and intended to equip a thin film deposition or coating machine using vacuum evaporation and in particular a machine having several sources for depositing a mixture of materials.
It is frequently necessary to control the speed of deposition or, in the case of a simultaneous deposition of several materials to regulate their proportion when it is wished to e.g. regulate the refractive index of a filter. Several methods exist. In one of them, for each source use is made of a quartz balance, which is connected to a servocontrol device, which deduces the evaporation speed from the readings of the balance and controls the variations of the source supply in order to obtain the desired flow rate. This servocontrol is not always adequate, because the response delay of the sources to the supply variations is not accurately known. According to another method, one of the materials is extracted from a source and then projected towards the object to be coated, whereas the other is introduced into the enclosure containing said object by another means, such as a flow of gas or ion bombardment. The first of these methods is not very accurate due to the inertia of the gas flow and their inadequate uniformity in the enclosure and the second requires a special apparatus.
A novel method is proposed with the apparatus according to the invention. It consists of using screens, masks or covers provided with openings and which constantly move in front of the source, so as to present in front of it the openings alternating with the solid parts. The cover is mobile relative to the source in such a way that it makes it possible to vary the degree of source hiding, i.e. the proportion of the time during which the source is covered by the solid parts compared with the total passage time. The flow rate of the source in the direction of the part to be covered is, under these conditions, perfectly defined. The support in which the cover is fitted is preferably mobile relative to that of the source, so that it is possible to continuously vary the hiding level on displacing the source. It is also possible to make the variations of the degree of hiding proportional to the support displacement.
A preferred embodiment of said apparatus comprises several sources and the same number of covers moved by motors. All the covers and motors are mounted on a single plate and the covers are designed in such a way that the displacements of the support relative to that of the sources bring about different variations of the degree of hiding of each source. It is then possible to freely modify the compositions of the deposits made.
The invention is described in greater detail hereinafter relative to non-limitative embodiments and the attached drawings,
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view of a vacuum evaporation coating machine using the apparatus according to the invention, the cover being a disk seen by its edge.
FIG. 2 is a view of an embodiment with two fixed sources, the complementary covers seen from the front being mounted on a support performing a translatory movement.
FIG. 3 is a view of a vacuum evaporation coating machine using the apparatus of FIG. 2.
FIG. 4 is a view of an embodiment with two sources, the identical covers seen from the front being in each case rotated about a fixed axis and the two sources perform an oscillatory movement on a circular path.
With reference to FIG. 1, the vacuum evaporation machine comprises an enclosure 1 in which is placed the sample 2 to be covered with a deposit in front of a source 3 subject to an evaporation, supplied by an electric cable 4 and a current generator 5.
A cover 6 is placed between the sample 2 and the source 3 and much closer to the latter. It is a disk of limited thickness and a shape which will be described hereinafter. In its centre it has a shaft 7, which spins it and which extends at some distance from the source 3. The shaft 7 is placed in a case 8, which contains an electric motor 9. The latter has a drive shaft 10 in the extension of the shaft 7 and which is separated from the latter by a tight partition 11 passing across the interior of the case 8. Thus, there is no mechanical connection between the drive shaft 10 and the shaft 7, but the drive is ensured by permanent magnets 12 located on their facing ends and which are constituted by groups of magnets arranged in ring-like manner and alternating poles positioned so as to produce an attraction force whilst opposing relative rotations.
Ducts 13 traverse the enclosure 1, the case 8 and lead to the electric motor 9. They contain electric supply wires and are traversed by a cooling air current. The electric motor 9 is consequently protected from the high temperature of approximately 300° C. created on the mask or cover 6 by the source 3. The shaft 7 rotates in an open part of the case 8 by means of ballbearings 14, which must not be lubricated with grease and which are covered with a thin molybdenum disulphide film. The balls are made from a ceramic material. The drive shaft 10 can be guided by ordinary ballbearings.
The case 8 is mounted on a table 15 serving as a support and which moves in the enclosure 1 towards the source 3 and away from the latter. It can e.g. be provided with a rack 16, which can be advanced by a pinion 17 controlled by a crank 18, which extends externally of the enclosure 1. It can be seen that the cover 18 is moved in front of the source 3, whilst remaining in the same plane, so as to pass in front of it a circumference with a selected diameter when the motor 9 is started up and the shaft 7 rotates.
The means for sealing the enclosure 1 and for creating the vacuum necessary for deposition under satisfactory conditions are of a conventional, not shown nature. The devices permitting the sliding of the table 15 and which can be constituted by slides or rails fixed to the wall of the enclosure 1 are also not shown.
FIG. 2 illustrates a machine having two fixed sources 3a,3b supplied by respective electric cables 4a,4b and cooperating with a respective cover 6a or 6b located on a support 15 performing a translatory movement on the rails 29 and rotating under the effect of a shaft 7a or 7b. Two main shapes for the covers 6 are shown. The first cover 6a is a disk having a circular outer contour 20 and which is provided with three lobe-shaped openings 21, whereof the arc extension ceaselessly decreases towards the periphery. The openings meet almost to form a circumference with a relatively small radius, but are then interrupted towards the inside in such a way that the first cover 6a has central surface 22a for connection to the shaft 7a. Three solid portions 23 extend between the openings 21 and meet at the periphery of the first cover 6a in order to form the circular outer contour 20, whilst being in one piece with the central surface 22.
The second cover 6b has a different shape, because it has three solid, lobed portions 24, whose shape is like the openings 21. The solid portions 24 are joined together and extend on the shaft 7b. Cavities 25 between the solid portions 24 form openings on the periphery of the second cover 6b, but which is solid within its contour 26. In the same way as the solid portions 24, the openings 21 are equidistant of the shaft 7 and regularly distributed over the circumference of the covers 6. The openings 21 and the solid portions 24 have identical shapes and sizes.
The covers 6a and 6b having complementary shapes rotate independently in the same plane. They can be moved by different motors or by a single motor having two transmission systems joining it to the two shafts 7a and 7b. In this embodiment of the invention shown in FIGS. 2 and 3, both the motors 9a and 9b are fixed to the table 15. The latter slides on rails 29 whilst the sources 3a,3b are stationary. A movement of the table in the direction S1, by a purely radial movement, moves the sources 3a,3b towards the rotation axis of their associated mask. Thus, the source 3a moves away from the circular outer contour 25 of the mask 6a, which increases the passage time of the openings 21 in front of the source 3a and decreases the passage time of the solid portions 23, i.e. the degree of hiding of the source 3a. The source 3b approaches in the same time and by the same quantity the shaft 7b, so that the passage time of the solid portions 24 and its degree of hiding increase. Therefore this apparatus makes it possible to bring about an opposite variation of the degrees of hiding of the sources 3a and 3b, whose sum remains equal to 1 if the lobes of the solid portions 24 are shaped for this purpose. The mixture deposited on the object to be covered has a variable composition and the deposition rate remains constant.
In another embodiment of the invention shown in FIG. 4, the covers 6c,6d are identical, have the same shape as the cover 6a and are at fixed locations in the enclosure 1, on which they are supported, but the sources 3 are attached to the ends of two arms of a balance or pendulum 27, which extends beneath the covers 6c,6d and which is mobile in its centre about a pivot 28, parallel to the shafts 7, which can be moved from the exterior of the enclosure 1 by a crank or a similar means.
Thus, unlike in the preceding case, instead of being fixed the sources 3a,3b perform an oscillatory movement on a circular path about the axis 28 of the balance 27.
The displacements of the balance 27 move one of the sources 3 away from the shaft 7 of the associated cover and does the opposite with the other source 3, whilst maintaining the sources 3 at a constant distance from the covers 6. A clockwise movement of the balance 27 consequently moves the source 3a radially towards the outer circular contour 20 of the first cover 6c, which reduces the passage time of the openings 21 in front of the source 3a and increases the passage time of the solid portions 23, i.e. the degree of hiding of the source 3a. The source 3b radially approaches in the same time and by the same quantity the shaft 7b, if the axis 28 is equidistant of the two sources 3, so that the passage time of the solid portions 23 and its degree of hiding decrease. Therefore this apparatus permits an opposite variation of the degrees of hiding of the sources 3a,3b, whose sum can remain the same if the lobes of the solid portions 23 are formed or shaped for this purpose. Thus, when the material flows from the sources 6c,6d are identical, the deposition rate remains constant and the mixture deposited on the object to be covered has a composition, whose variation is controlled by the conditions imposed by the shape of the covers and the movement of the balance.
It is clear that covers having different shapes or positioned at different locations would make it possible to vary the degrees of hiding in accordance with other principles, i.e. with different variations, as a function of the sought result and in particular the fineness of the regulation of the composition or the deposition rate of the mixture which is evaporated and then deposited. These results can be achieved by placing the sources 3 at the end of different arm lengths of the balance, by using the covers with lobes or openings of different widths, or by placing the covers on two sides of the balance. It is also possible to use covers 6 and shafts 7 which are detachable and which can be replaced for each machine use. Conversely, it would be possible to fix the sources 3 to the enclosure 1 as in the preceding embodiment and place the covers 6 and their motor 9 on the balance.
A vacuum evaporation deposition machine of the same type can be equipped in the same way with identical covers having the same shape as the cover 6b.
The shapes of the lobes are advantageously chosen in such a way that the variations of the degree of hiding are proportional to the displacements. In the case of translatory movements between the source 3 and the cover 6, this result is achieved if the limits of the openings or lobes are spiral portions (of equation R=aθ+b, in which a and b are constant coefficients, with the conventions of FIG. 2 and in which R and θ are polar coordinates centered on the shaft 7).
Covers other than rotary disks are possible and endless belts or belts subject to an alternating movement and having a sawtooth contour are possible examples. The fundamental advantages of the invention, namely the ease, precision and fineness of the evaporation flow from the sources towards the object to be covered would be retained.
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Source evaporation machine for covering samples optionally by a mixture produced by several sources (3).
Mobile covers (6) are placed between the sources (3) and the sample. The covers (6) are designed so as to ensure that the solid parts (23,24) and the openings (21,25) alternate and the sources (3) move relative to the covers in such a way that different circumferences of the covers pass in front of them. As the angular sectors surrounded by the openings differ for each circumference, the degree of hiding of the sources (3) can be regulated in a very accurate and reliable manner. It is possible to modify the flow of the source on the sample or, in the case of several sources, vary the composition of the deposited mixture.
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This application is a continuation-in-part of U.S. Ser. No. 084,307, filed Aug. 11, 1987, now abandoned.
FIELD OF THE INVENTION
The instant invention relates generally to an interlock system for use in an array of vertically stacked storage elements or cradles designed to prevent the opening of more than one storage element at any one time. If more than one element is opened at any one time, the array can become unstable and tip, causing injury. Thus, the incorporation of an interlock system is necessary to insure the safety of employees and users of vertically disposed storage elements.
DESCRIPTION OF THE PRIOR ART
File interlock systems are necessary, and in some situations required by law, in order to protect personnel from the potential "tipping" hazard created if more than one storage element of a vertical array of file drawers is opened at one time. The prior art describes many types of interlocks for use in office cabinets. These interlock devices all depend on various complex combinations of sliding bars, springs, cables and cams, and the majority are either too cumbersome and complicated, or too easily overcome.
For example, U.S. Pat. No. 3,378,321 for "Filing Cabinets", relates to a filing cabinet having a series of laterally stacked drawers, each attached to each other by a cable. Tension on this continuous cable prevents more than one drawer from being withdrawn from the cabinet at any one time. However, the cable may be cut by an overanxious user.
U.S. Pat. No. 3,870,387, for a "File Drawer Interlock Mechanism", describes a mechanism in which a channel is mounted on each drawer and a series of corresponding rollers are mounted on a single sliding lock bar mounted within the cabinet. The lock bar is configured in such a manner that when one drawer is withdrawn the channel attached to that drawer engages a corresponding roller on the lock bar causing the lock bar to shift in position. In this shifted position none of the remaining channels can engage any of their respective rollers and therefore, opening of any of the remaining drawers is prevented. This type of interlock mechanism is one of several in the prior art which use a sliding lock bar mounted in a cabinet, which shifts in position when engaged by a cam or other mechanism mounted on an opened drawer. It is sometimes cumbersome, and not capable of being retrofit on an existing cabinet, in other words, it must be manufactured with the interlock in place.
U.S. Pat. No. 3,900,236 for a "File Interlock" describes a side mounted interlock for use in a filing cabinet in which a series of individual lock bars are used rather than one continuous lock bar. In addition, a rotating cam is used to maintain the lock bars in a blocking position when any one of the drawers is open. The multiple lock bar system has an advantage in preventing the defeat of the interlock by attempted forced opening of more than one drawer simultaneously. It, too, is cumbersome and generally incapable of a retrofit or modification.
U.S. Pat. No. 4,272,138 describes a "Cabinet Drawer Antitip Lock Device" which uses a series of multiple lock bars held in place by a fixed cam mounted to each drawer. This also suffers the aforementioned drawbacks.
The abstract of Netherlands Patent No. 7,604,359, shows a series of lugs that swing levers into recesses in a set of similar components, to provide an interlock. This, too, suffers the drawbacks.
U.S. Pat. No. 4,711,505 to Lakso discloses a line of balls contained in a channel and compressed via springs 39 at either end of the channel. Each drawer is provided with an actuator and a ball 36. The actuator is essentially a metal plate that possesses a chamfered recess 38 in which at least a portion of the ball resides in the unlocked position. As actuator 38 swings (that is a drawer is opened), the ball 36 is forced out of the recess 38 against the metal plate of the actuator, on one side, and against but not into the line of balls on the other, locking, in theory, the line in place and barring insertion of any additional ball 36, and thus no other drawers may open. However, the Lakso device will not function if the ball 36 enter the line of balls fully, because there is no extraction mechanism for removing the ball from the line. It is contemplated that the Lakso device will suffer from periodic jamming to the extent that the ball 36 becompes trapped by the bias effect of the line of balls. This complicated device also suffers from the same drawbacks generally mentioned above.
U.S. Pat. No. 4,447,098 to Parker deals with a manually moveable series of blocking elements 36 which, in order to be operated, must be manipulated by the user before attemps can be made to open a drawer. The blocking elements in Parker are also placed upon a guide 38 as an additional manufacturing step rather than being place in an already existing support member. Thus, though this manually assisted device is simple, it is inaccurate, as it is dependent upon the user to set up, and is also incapable of a retrofit. Generally, an interlock must also be invisible and inaccessible to the user to prevent the user from removing it. Parker also fails in this regard.
The instant invention resides in changes to the slidable mounting means ("slide"). The slide is retractable, and is mounted on the storage elements and support structure of the cabinet (columns, etc.). Prior art slides are known and commonly used in file cabinets to support and provide the articulation for lateral file drawers. Such devices are manufactured by companies such as Thomas Regout NV, the Netherlands. Each slide features a movable slide section or sections upon which a storage element is mounted and a stationary slide section which is affixed to a supporting wall or post of the cabinet or array structure. The movable slide section features a detent cam mechanism which is used to hold the drawer in a closed position until force is applied to open it, thereby preventing the drawer from opening by itself due to vibration or imperfect placement.
All of the interlock devices known to applicants are cabinet-based and feature complex structures which must be installed as part of the cabinet at the time the cabinet is manufactured. None of these devices is designed to be retrofitted into an existing cabinet or prefabricated shelving system, or is invisible and innaccessible to the user, or is failsafe and accurate.
Therefore, it is one object of the present invention to provide an interlock system for use with an array of retractable storage elements which prevents more than one element from being open at any one time.
It is a further object of the present invention to provide an interlock system which can be installed in an existing cabinet or prefabricated structure.
It is yet a further object of the present invention to provide an interlock system that is relatively invisible and inaccessible to the user.
It is still a further object of the present invention to provide an interlock system for use in an array which is self-aligning and accurate for repeated use.
SUMMARY OF THE INVENTION
The instant invention replaces the sliding lock bar, multiple lock bar and cable systems known in the prior art with an interlock system utilizing a substantially filled member placed within one or more walls or columns of a cabinet or prefabricated vertical array of retractable storage elements.
These storage elements are generally comprised of cradles each of which can, with the addition of a front face, act as a drawer, or alternatively form a base for a file shelf. As used herinafter "cradles" include drawers, shelves, platforms and the like.
File cabinets are designed basically to comprise two side walls and optionally a rear wall. File cabinets can be constructed using column supports, and a rear support. It is to be understood that the particular design of the file cabinet superstructure or skeletal structure is not critical to the invention, and any known design can be made to accomodate the instant interlock.
Cradles are retractably mounted within a cabinet on telescoping slides. Such slides are shown herein to also function as structural support members, attaching horizontally to vertical columns. Similarly the cradles of a prefabricated array can be slide-mounted to other support members of the array.
In the instant invention, the prior art telescoping slide is modified by installing an insertion-extraction cam and insertion plunger along a portion of the stationary section of the slide and in contact with the detent cam of the slide. Also, each side wall of a cabinet, or vertical support member (column) of a prefabricated array, is fitted with a vertical slide trough with a retaining lip. This trough is substantially filled with blocking members, held in position by the lip. Each blocking member is generally tubular, cylindrical or spherical, and can be fabricated in many shapes, and of extruded plastic or other rigid or semi-rigid materials.
In one embodiment of the invention, the partially filled blocking member comprises a channel containing a plurality of slidable components which can move relatively freely within the available space of the channel. Each of these slidable components is shown equal diameter or dimension, though the dimensions are not critical and even differently components will work. The channel contains a number of components such that an unfilled portion of the channel (void) is created of special vertical dimension (height).
When a cradle is opened, the detent cam of the stationary section of the slide is forced to rotate by an engaging tab attached to the movable section of the slide means which is attached to the cradle. The detent cam possesses a cam on its forward face which, simultaneously with the opening of a cradle, engages a pivoting armiture which urges its insertion head portion into the channel or trough substantially filling the void between the components, and causing the slidable components therein to shift position as necessary. The respective insertion heads associated with the remaining closed cradles are thus blocked from entering the channel and therefore these cradles cannot be opened.
If an attempt is made to open two or more cradles simultaneously no drawers will open because the unfilled portion of the channel will allow the entry of only one insertion head at a time. Since the insertion head on other unopened cradle slides will not be able to enter the channel, the cam will not be able to turn and the detent cam section will remain stationary, confining the detent and disallowing the opening of the cradle. Once the open cradle's slide is closed, the detent pushes its associated cam rearwards of the cabinet, and the cam on the forward face allows the spring loading armiture to ease rearward, as well, thereby extracting, by positive action, the insertion head from the channel. After extraction, any one cradle can next be opened and the operation of its interlock is repeated.
The instant interlock is designed so that the spacing between the storage elements can be irregular and adjustable when used in a prefabricated shelving system. This is because the number and spacing of the storage elements are not dependent on a matching number of blocking elements, e.g. lock bars.
It is, therefore, a feature of the present invention to provide an interlock which can be easily installed in a file cabinet or a prefabricated structure.
It is a still further feature of the invention to provide an interlocked vertical array of retractable storage elements which can be irregularly spaced.
It is yet a further feature of the invention to provide an easily installed insertion-extraction cam which is controlled by simple modification of the detent cam built into the drawer slide.
It is another feature of the invention that it can be used with a prefabricated filing structure built to meet design requirements specified by an architect or customer.
It is still a further feature of the invention to provide a self-aligning insertion head controlled by action of a positive action insertion-extraction mechanism.
These and other objects and features of the present invention will become more apparent when taken in conjunction with the following description and drawings, wherein like characters indicate like parts.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric, partially sectional view of an array of vertically mounted retractable cradles incorporating one embodiment of the instant invention.
FIG. 2 is side sectional view of a portion of FIG. 1, taken along line 2--2, and showing a cradle in the closed position.
FIG. 3 is a side plan view of FIG. 2, taken along line 3--3 thereof.
FIG. 4 is a bottom plan view of FIG. 2, taken along line 2--2 thereof.
FIG. 5 is side sectional view of a portion of FIG. 1, taken along line 2--2 thereof, and showing a cradle in the open position.
FIG. 6 is a side plan view of FIG. 5, taken along line 6--6 thereof.
FIG. 7 is a bottom plan view of FIG. 5, taken along line 7--7 thereof.
DETAILED DESCRIPTION OF THE INVENTION
In order to prevent tipping, safety dictates that a prefabricated array of vertically stacked retractable cradles or a similarly designed cabinet be provided with means to prevent more than one cradle from being opened at any one time. An array of vertically stacked retractable cradles 1 comprising one embodiment of the instant invention is described in FIG. 1. The cradles are mounted to a plurality of prefabricated structural members by horizontally mounted slides, each supplied with a detent cam.
FIG. 1 describes four vertical, rectangularly disposed posts 3, 5, 7 and 9 which are designed to be fastened together by various horizontal members 4 and with other structural members (not shown) in order to form a prefabricated office shelving system or office dividing wall system 1. This type of prefabricated structure is designed to be constructed to the specification of the customer and the posts can support a variety of storage elements such as stationary or retractable cradles which in turn can support document files, recording files, shelves with adjustable dividers etc. Posts 3, 5, 7 and 9 are each formed with a trough 11 running along the longitudinal axis of each member, each trough having a retaining lip 13. Three retractable cradles 15 are each mounted on pairs of slides 21. Cradles can be configured to accomodate whatever elements are desired to be stored therein. Thus the cradle could be provided with a front face or door (to make a drawer, for example), though this is not shown for simplicity. Only one drawer is shown in FIG. 1, modified in accordance with the invention, but it is to be understood that the same modification is provided for each successive, lower cradel in the array 1, provided, as stated below, that the interlocks all align on the same column.
Slides 21 are designed to provide the slidable opening and closing of the cradles in order to allow access to the contents, each including a biased detent cam 23 which, among other things, retains retractable cradles in a closed position and provides interlock features in the open position, as explained further below. Only one slide per cradle need be modified in the instant invention, provided the interlocks are all aligned on the same column. FIG. 1 shows an interlock on both sides of the first cradle simply for ease of understanding the invention.
As part of the instant invention the slides 21 mounted to post 3 or 7, for example, are modified as follows. First, the cam is replaced with a new cam 23 having on its rearward face the standard detent cam for holding the cradle closed, and on its forward face a new cam for engaging the armiture 25 which pivots and inserts the insertion head 27 into the vertical trough 11.
Each of the columns 3, 5, 7 and 9 possesses a trough 11 which defines a channel 30. At least one of these channels is partially filled with a plurality of movable components 31 which are shown as generally having the same shape, though the shape, itself, is not critical to the invention. Channel 30 can be a plastic extrusion which is inserted into trough 11 and held in place by retaining lip 13.
The center cradle 15 is shown in the open position and its corresponding slides 21 are shown in the extended position showing stationary slide section 33 and movable slide sections 35 common to all of the slides 21.
FIG. 2 through 4 are detailed views of top cradle 15 in the closed position, showing an enlarged view of slide 21 comprising stationary slide section 33 and movable slide section 35, as well as armiture 25, insertion-extraction cam 23, post 3 or 7, trough 11, channel 30 and components 31. FIG. 2 is a partially sectional view from the inside of the structure 1 along line 2--2. Insertion-extraction cam 23 is shown held in the "closed" position by the tension of spring 39. Movable section 35 of slide 21 is retracted within stationary section 33 and engagement tab 37 of movable section 35 is held in place within slot or detent 38 of cam 23. Slot 38 is formed with two ridges 49 and 51 which are formed of walls perpendicular to the plane of the cam 23 (i.e., outwardly from the plane of the page) and which contact the tab 37. Cam 23, on its rearward face possesses detent 38 with walls 49 and 51. On its forward face, cam 23 is adapted with a protrusion (essentially another cam) 53 which in operation articulates armiture 25 by contacting a pin 57. Armiture 24 is attached to the back of stationary slide section 33 via pivot 57, and thus is shown in dotted form in FIG. 2. Pin 59 passes through slide section 33 and rides the contours of protrusion 53, in operation. Armiture 55 is biased by spring 55 such that it is forced rearward, away from the line of movable components 31.
Fitted on the lower section of armiture 25 is insertion head 27, swingably mounted by pivot pin 59 such that the head 27 can move 5 to 10 degrees from its center to provide alignment with the line of components 31, in operation, to ensure a precise fit.
As shown in FIG. 3, channel 30 is formed with an open face 50, resembling the letter "C" when viewed from the top. Components 31 are slidably stacked within the channel 30, and are held horizontally in place by the arms of channel 30. The insert of head 27 is in alignment with the opening of trough 11 and the open face 50 of channel 30.
FIG. 3 shows the invention along lines 3-3 of FIG. 2, in the closed position, and the various components identified above.
FIG. 4 is a cross-sectional view looking upward along line 4--4 of FIG. 2, showing the placement of the interlock device in a standard column 3 or 7 and slide 21. Between the trough 11 and rectangular wall 67 of the column 3 or 7 is a gap 61 which provides for the placement and movement of armiture 25. Tab 63 provides for the mounting of the modified slide within grooves 65 of the columns 3, 5, 7 and 9 (see FIGS. 2 and 1).
FIGS. 5 through 7 depict the embodiment of the invention shown in FIGS. 2 through 4, with the cradle in the open position. When the cradle is withdrawn, the movable section 35 of slide 21 extends outwardly from stationary section 33. Movable section 35 supports the cradle in the open position as shown in FIG. 1. As movable section 35 is urged forward by the force applied to open the cradle, engagement tab 37 engages ridge 51 of detent cam 23 causing it to overcome the bias provided by the spring 39 and rotate to its "open" position. As this occurs, rearward cam 53 of cam 23 rides along pin 57 (which passes through stationary section 33 and attaches to armiture 25), causing armiture 25 to move forward in the same direction as movable section 35. As the bias caused by spring 55 is overcome by movement of cam 23, insertion head 27 is urged forward, and enters channel 30, displacing the components 31, and generally filling the remaining volume within the channel 30. Therefore, with any one cradle in the open position, insufficient room remains in the channel for the entry of another insertion head corresponding to another cradle. The result is that one and only one cradle can be opened at one time.
Critically, we have identified the maximum void or vertical space 69, as shown in FIG. 6, to be at least as large as the vertical height of the insertion head 27, but less twice its height, in order for the interlock to be effective. In other words, with respect to dimension (x), as shown in FIG. 5, and dimension (y) as shown in FIG. 6:
x≦y<2x
If y becomes larger than 2x, it is possible that more than one drawer can be opened at one time, since two insertion heads 27 of height x can thereby be inserted. Thus, these dimension become very critical.
It can also be seen that the precise shapes of the components 31 are less critical than the size of the void 69. Even variously different shaped components 31 can be used without impeding the operation of the system, provided these components can be fitted into trough 11 and channel 30, and provided they allow some tapering for insertion of head 27.
Spring 39 is attached to the detent cam 23 in such a manner as to exert retaining tension on the detent cam 23 in both its "open" and "closed" position. This tension tends to retain the cam in whichever position it is in. In its "open" position, the curved orientation and stop of the forward cam 53 against the pin 57 tends to hold the slide and drawer in an open position, as the forces acting thereon tend to balance one another, until the user urges the drawer closed, at which time, the pin rides the contours off cam 53, and the cooperative spring biases 39 and 55 assist in providing positive action for extraction of the head, simultaneously bringing the slide to a closed position. Thus it can be seen that the bias created by the components 31 do not affect the operation of the insertion-extraction, as the insertion head 27 is inserted beyond the point where the bias has any effect, and is extracted by action of the bias of the spring.
In operation, when cradle 15 is returned to the closed position, the engaging tab 37 of movable member 35 engages ridge 49 of detent cam 23 urging it to rotate against the tension of spring 39 and into its "closed" position once again. In its "closed" position, detent cam 23 tends to lose contact with pin 57, and thus spring 55 holds the armiture 25 in place, preventing insertion into the channel.
In terms of construction, components 31 should be shaped to allow efficient intergration with and separation by the plunger cam insert and ease of movement within the channel, and should be hard but not brittle and can be made of metal, plastic, hard rubber, wood, ceramic, or other resilient materials. The posts and other structural members are properly constructed of steel or sheet metal and the channel can be a plastic extrusion or suitable molded or cast material. The armiture can be made of plastic, steel or other suitable material, although steel is preferred to prevent breakage by tugging. The insertion head can be of hard plastic, matching the construction of components 31.
In a prefabricated array of shelves, the instant invention allows the cradles to be spaced at irregular intervals within the limits of cradle size and the mounting constraints of the slide mounts, by placement of grooves 65 at increments along the columns (see, e.g., FIG. 1), into which tabs 63 may be inserted (see, e.g. FIGS. 4 and 7). In addition, the instant interlock system permits an array of stationary prefabricated shelves to be converted at a later date to an array of retractable cradles by inserting a prefabricated channel with slidable components e.g. spheres or cylinders or the like, into at least one of the support posts (which must already have the trough formed within it) and mounting the cradles upon slides as modified by the instant invention described above. This retrofit is easy, and effective.
A lock can also be provided by mounting a rotating or sliding cam on the post in which the channel in installed. The cam can be made to enter the channel when all of the cradles are closed, thereby taking up the remaining volume and preventing any of the cradles from being opened.
Although the embodiment described above, are shown mounted along only one side of the structure, it is to be understood that the embodiments described can be placed on both sides and work together to accomplish in reinforced fashion, the interlock effect of the instant invention. In addition, combinations of the embodiments can be used within one particular cabinet.
While the invention has been particularyly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes in form and details may be made therein without departing from the spirit and scope of the invention.
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An interlock system for use in an array of retractable storage cradles. The instant system prevents the opening of more than one cradle at one time through a slide modified generally by a biased cam insertion-extraction means and a column of movable components. The system can be used in free-standing file cabinets as well as prefabricated and modular storage units.
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FIELD OF THE INVENTION
The present invention relates generally to fountain pens and more specifically to the refillable ink cartridges used in fountain pens.
BACKGROUND OF THE INVENTION
In general there are three methods of supplying ink to a fountain pen: (1) dipping the nib directly into an ink well to coat the same with ink; (2) providing a disposable ink cartridge that is inserted into the body of the pen such that fluid communication is established between the ink cartridge and the nib to supply the same with ink; and (3) providing a refillable ink cartridge that is either removable from or integral with the body of the pen and such that fluid communication is established between the ink cartridge and the nib. The refillable ink cartridges are often referred to as piston converters by the skilled artisan. A piston converter, in general, is a hollow body with a plunger slidably disposed therein. The hollow body is fluidly connected at one end to the nib of a fountain pen. In order to fill a piston converter with ink, the plunger is pushed forward into the hollow body, the nib of the pen is substantially submerged into a well of ink (in the case of a removable type converter, an end of the hollow body is inserted into the well of ink), and the plunger is withdrawn, thereby drawing ink into the hollow body; the operation is analogous to drawing fluid into a syringe. The plunger remains in the hollow body, thereby sealing one end of the hollow body. The second end of the hollow body, as mentioned above, is in fluid communication with the nib. After filling the piston converter the pen can be used until the ink runs dry, after which the process is repeated to fill the piston converter with ink again. In some cases a removable piston converter can be replaced by a disposable cartridge if the user prefers disposable cartridges over piston converters.
In one prior art piston converter the plunger is moved within the hollow body by a drive mechanism. The general concept of the drive mechanism uses a plunger shaft connected to the plunger and a drive member fixed relative to the hollow body and engaged with the plunger shaft. The plunger shaft has either external or internal threads, and the drive member has threads that mate with the threads of the plunger shaft. Because the drive member is fixed relative to the hollow body, turning the drive member causes its threads to rotate, which causes the plunger shaft to move longitudinally relative to the hollow body. Thus, turning the drive member moves the plunger within the hollow body permitting a user to draw ink into the hollow body.
One disadvantage to using this drive mechanism for piston converters is that the drive member is often inadvertently rotated, thereby causing a relatively large quantity of ink to discharge out of the nib. This inadvertent ink discharge can stain clothes, hands, fingers, it can ruin documents and virtually anything else it contacts. Likewise, inadvertently rotating the drive knob may cause air to be drawn into the hollow body, thereby affecting the performance of the pen. Thus, there is a need in the art for a piston converter with a drive mechanism that a user selectively activates, which, among other things, will substantially prevent the accidental discharge of ink from a fountain pen.
SUMMARY OF THE INVENTION
A preferred embodiment of a piston converter in accordance with the present invention includes a hollow body having a distal end and a proximal end, a plunger assembly, a metering knob, a drive rod, and an engagement rod. The distal end of the hollow body provides fluid communication between the hollow body and a nib of a fountain pen. The plunger assembly, preferably a plunger attached to a plunger rod, is slidably disposed in the hollow body. The metering knob is configured to engage the plunger assembly, preferably the plunger rod, to advance or withdraw said plunger within said hollow body. The drive rod is configured to engage the metering knob such that turning the drive rod will turn the metering knob, which will advance or withdraw the plunger assembly. An engagement end of the engagement rod is configured to selectively engage the drive rod, preferably by drawing or pushing the engagement end into or out of a cavity within the drive rod configured to engage the engagement end, such that when in the engaged position turning the engagement rod will cause the drive rod to turn which will cause said metering knob to advance or withdraw said plunger within said hollow body.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial cross-sectional view of a fountain pen with a piston converter in accordance with an embodiment of the present invention;
FIG. 2A is an enlarged partial cross-sectional view of the top half of the fountain pen and piston converter of FIG. 1;
FIG. 2B is a cross-sectional view of a drive knob from the fountain pen in FIGS. 1 and 2A;
FIG. 3 is a cross-sectional view of a hollow body from the fountain pen and piston converter of FIGS. 1 and 2A;
FIG. 4 is a cross-sectional view of a drive rod from the piston converter depicted in FIGS. 1 and 2.
FIG. 5 is a three-dimensional view of an engagement rod from the fountain pen and piston converter of FIGS. 1 and 2A;
FIG. 6 is a cross-sectional view of a drawer from the fountain pen and piston converter of FIGS. 1 and 2A;
FIG. 7 is a cutaway three-dimensional view of a sleeve from the fountain pen and piston converter of FIGS. 1 and 2A; and
FIG. 8 is a three-dimensional view of a sleeve from the fountain pen and piston converter of FIGS. 1 and 2 A.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 1 and 2 there is shown a fountain pen 2 with piston converter 4 in accordance with an embodiment of the present invention. Piston converter 4 has a hollow body 6 , a plunger 8 , a plunger rod 10 , a metering knob 12 , a drive rod 14 , an engagement rod 16 , and a drive knob 18 .
Referring to FIGS. 1-3, plunger 8 is slidably disposed in hollow body 6 . Plunger rod is attached to plunger 8 and has external threads 20 . Metering knob 12 is preferably a hollow cylinder with internal threads 22 configured to engage external threads 20 of plunger rod 10 . In an alternative embodiment the metering knob has external threads that engage internal threads in a hollow plunger rod. A skilled artisan will readily recognize that other means of engagement between metering knob 12 and plunger rod 10 may be used without departing from the scope of the present invention. Metering knob 12 abuts proximal end 24 of hollow body 6 , and is fixed relative thereto, for example, by crown 26 . Cover 28 is affixed to distal end 30 of hollow body 6 and has an orifice (not shown) therethrough to provide fluid communication between hollow body 6 and tube 32 and to provide fluid communication from hollow body 6 to a nib (not shown) of fountain pen 2 .
Referring to FIGS. 1, 2 , and 4 , drive rod 14 is preferably a hollow cylinder. Externally, drive rod 14 has ridge 34 towards its proximal end 36 , followed by a narrower straight cylindrical region 38 and then by circular barb 40 at its proximal end 36 . Drive rod 14 has teeth 42 at its distal end 44 that engage similarly shaped teeth 46 on proximal end 48 of metering knob 12 (the latter is best shown in FIG. 3 ). A skilled artisan will readily recognize that other alternatives for this engagement may be used, including without limitation, permanently joining the two pieces. Internally, drive rod 14 , towards proximal end 36 , has nut cavity 50 configured to engage with nut 52 on distal end 54 of engagement rod 16 (the latter is best shown in FIG. 5 ), which is described in more detail below.
Referring to FIGS. 1-3, and 6 - 8 , piston converter 4 is secured in pen 2 by drawer 56 , sleeve 58 , cap 60 , and cylindrical collar 62 . Drawer 56 (best shown in FIG. 6) is half of a hollow cylinder with distal band 64 and proximal band 66 . Distal band 64 receives cover 28 of hollow body 6 . Proximal band 66 secures cylindrical collar 62 to drawer 56 . Cylindrical collar 62 receives sleeve 58 therethrough. Referring to FIGS. 6 and 7, sleeve 58 is a hollow cylinder. Internally, sleeve 58 has ridge 68 configured to abut ridge 34 of drive rod 14 (the latter is best shown in FIGS. 2A and 4) when the two pieces are mated together, as more fully described below. Externally, sleeve 58 has abutment 72 towards its distal end 74 , shelf 76 towards its proximal end 78 followed by rim 80 , followed by indentation 82 and then by flared rim 84 that preferably has a slightly smaller outer diameter than rim 80 .
Proximal end 78 of sleeve 58 slides into and through collar 62 and is snap fit into cap 60 such that rim 80 snaps over the top of concentric ring 86 of cap 60 , and such that shelf 76 of sleeve 58 abuts distal side 88 of concentric ring 86 . Additionally, when sleeve 58 is snap fit into cap 60 , flared rim 84 extends through hole 90 and into cylindrical cavity 92 of cap 60 . In this manner drawer 56 and sleeve 58 are affixed to cap 60 , because abutment 72 prevents collar 62 from passing over distal end 74 of sleeve 58 , and sleeve 58 is fixed into cap 60 by rim 80 , as previously described. The octagonal shape 94 of the central portion of sleeve 58 (best shown in FIG. 7) is configured to mate with a similarly shaped surface (not shown) inside of cap 60 , thus preventing rotation of sleeve 58 within cap 60 .
Referring to FIGS. 1 and 2, proximal end 36 of drive rod 14 is slid into distal end 74 of sleeve 58 such that circular barb 40 snap fits over flared rim 84 of sleeve 58 and such that drive rod 14 may rotate with respect to sleeve 58 . Proximal end 96 of engagement rod 16 extends out of proximal end 36 of drive rod 14 and drive knob 18 is fixed thereto by adhesive and threads. The skilled artisan will recognize many other ways of fixing drive knob 18 to engagement rod 16 , such as and without limitation, press fitting, locking threads, or pins.
Referring to FIG. 2B, drive knob 18 has internal cavity 98 with groove 100 around the inside wall thereof, and cylindrical ring 102 at distal end 104 of drive knob 18 . Cylindrical ring 102 has a smaller outside diameter than the inside diameter of cylindrical cavity 92 of cap 60 . When drive knob 18 is pushed in the distal direction into the unengaged position flared rim 84 of sleeve 58 removably snap fits into groove 100 . When in the unengaged position, drive knob 18 may preferably rotate about its central axis. When drive knob 18 is pulled in the proximal direction into the engaged position, drive knob 18 snaps out of its unengaged position such that the top of flared rim 84 rests against cylindrical ring 102 , which prevents drive knob 18 from returning to the disengaged position unless the user snaps it back into the disengaged position.
Referring to FIGS. 4 and 5, distal end 54 of engagement rod 16 is shaped as nut 52 . Nut 52 may have an approximate shape selected from a group consisting of an eight-sided nut, a seven-sided nut, a six-sided nut, or a five-sided nut. When engagement rod 16 is moved in the proximal direction, by unsnapping drive knob 18 into the engaged position, nut 52 engages with nut cavity 50 , such that rotation of drive knob 18 causes drive rod 14 to rotate. When engagement rod 16 is moved in the distal direction, by snapping drive knob 18 into the unengaged position, nut 52 disengages from nut cavity 50 , such that rotation of drive knob 18 will not cause drive rod 14 to rotate. The specific hex-nut configuration of the preferred embodiment is not necessarily required. The skilled artisan will readily recognize that engagement rod 16 may selectively engage drive rod 14 externally rather than internally, and that selective engagement may be achieved using any number of other alternatives, including without limitation having selective engagement between drive knob 18 and proximal end 96 of engagement rod 16 or drive rod 14 . Additionally, the skilled artisan will readily recognize that many alternatives may be used to engage drive rod 14 with engagement rod 16 , such as and without limitation shapes with more or less than eight sides may be use, tapered shapes may be used, threads may be used, or teeth may be used.
To use piston converter 4 a user snaps drive knob 18 into the engaged position and rotates it, which rotates drive rod 14 , which rotates metering knob 12 , which, through engagement of external threads 20 of plunger rod 10 with internal threads 22 of metering knob 12 , causes plunger 8 to advance or withdraw within hollow body 6 . When the user has drawn ink into hollow body 6 , the drive knob is snapped into the disengaged position such that rotation of drive knob 18 will not advance or withdraw plunger 8 .
Although various embodiments of the present invention have been described, the descriptions are intended to be merely illustrative. Thus, it will be apparent to the skilled artisan that modifications may be made to the embodiments as described without departing from the scope of the claims set forth below.
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A piston converter for a fountain pen that permits a user to selectively engage the drive mechanism to the converter is disclosed. The converter has a hollow body fluidly connected to a nib of the pen at one end and a plunger assembly slidably disposed therein. The plunger assembly is engaged to a hollow drive rod. An engagement rod with a first end and an engagement end extends into the drive rod. The drive rod has an internal cavity configured to engage the engagement end of the engagement rod. The engagement end of the engagement rod can be selectively moved into or out of the engagement cavity, thereby permitting selective engagement of the drive mechanism for the piston converter.
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This is a divisional of copending Ser. No. 08/262,353, filed Jun. 20, 1994, which is a continuation of Ser. No. 08/135,575, filed Oct. 13, 1993, now abandoned, which is continuation of Ser. No. 08/022,433, filed Feb. 16, 1993, now abandoned, which is a continuation of Ser. No. 07/540,399, filed Jun. 19, 1990, now abandoned, which is a continuation of Ser. No. 07/279,907, filed Dec. 5 1988, now abandoned.
The present invention relates to improved methods of food processing. More specifically it relates to improving the firmness of fruits and vegetables which are processed by blanching followed by sterilization.
BACKGROUND OF THE INVENTION
Thermal processing is one of the most important methods mankind has developed for extending the storage life of perishable foodstuffs. However, the thermal process causes some destruction of the food qualities. Nutritional value, texture, color and flavor are usually damaged to a greater or lesser extent during the thermal process.
The soft texture of most canned vegetables is recognized as a major quality defect. It is probably one of the main reasons why the sales of canned vegetables are declining while sales of fresh vegetables are increasing. Protecting food against excessive softening caused by thermal processing is an on-going problem.
VanBuren et al, J. Food Sci., 27:291 (1962), have processed snap beans using a low temperature blanch at about 170° F. before canning to give a firmer-textured canned snap bean as compared to the conventional blanching at 200° to 212° F. The vegetable canning industry typically uses a blanch temperature of about 170° F. for snap beans. Similarly, Lee et al, J. Food Sci., 44:615 (1979) have shown that a 170° F. blanch gives firmer textured canned carrots.
Large quantities of vegetables and fruits are preserved by canning. This technology requires enclosing the product in hermetically sealed containers and heating at a specified temperature for a specified time to destroy all microorganisms inside the container. Products with a pH above 4.5 require a substantial heating regime to obtain commercial sterility. For example, green beans packed in brine in 1 lb cans require 22 minutes at 240° F. or 13 minutes at 250° F. This heavy heat treatment cannot be compromised because microorganisms of public health significance, such as Clostridium botulinum, require this degree of heat treatment to be destroyed. Unfortunately, this amount of heat causes great damage to the food texture. Most canned vegetables have a softer than desirable texture.
The present invention relates to a process for improving fruit and vegetable firmness, particularly in thermal processed foods.
BRIEF DESCRIPTION OF THE INVENTION
One object of the present invention is to improve the firmness of canned fruits and vegetables subjected to thermal sterilization processing by predetermining optimum low-temperature blanch temperatures for each food from softening curves and a plot of the rate of firmness increase with blanch temperature.
Another object is to provide a process to prepare canned fruits and vegetables having improved firmness qualities by using lower blanch temperatures and optimum holding times prior to sterilization to replace or as an adjunct to conventional processing methods.
Another object is to maximize the factors that contribute to food firmness by selecting conditions for increasing the firmness and simultaneously countering conditions which have the effect of softening the food.
Yet another object relates to a low temperature blanching process for maintaining the firmness of fruits and vegetables subjected to sterilization processing which comprises blanching the fruits or vegetables at a temperature of from about 125° F. to about 160° F. prior to sterilization for a time sufficient to cause said fruit or vegetable to remain firmer after sterilization as compared to said fruit or vegetable sterilized without said blanching step.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a softening curve graph of log extrusion force (KN) versus process time in minutes for diced beets processed at 220° F.
FIG. 2 is a softening point curve where firmness (N) is plotted against processing time in minutes for cut green beans in #303 cans, blanched at 3 minutes at 74° C. (165.2° F.); the National Food Processor recommends a process time of 22 minutes at this temperature.
FIG. 3 is a graph comparing a softening curve for Nantes carrot blanched 4 minutes at 74° C. and 100° C. respectively before processing at 100° C.
FIG. 4 is a series of graphs for Nantes carrots processed at 250° F. where the log of the firmness is plotted against process time in minutes together with equations for lines of best fit and correlation coefficient R, data used to measure substrate "b" and thermal firmness value (y-axis intersect).
FIG. 5 is a plot of the thermal firmness versus hold time (minutes) after 3 minutes blanching at various temperatures where the slope of lines equal the rate of firmness increase.
FIG. 6 is a plot of the rate of firmness increase (Newtons per minute) vs. blanch temperature (degrees Fahrenheit) for Chantenay var. carrots. From the graph, optimum blanch temperatures can be selected based on rates of firmness increase.
FIG. 7 is a graph of rate of firmness increase versus blanch temperature for three varities of green beans, namely Labrador, Bonanza and BBL 47.
FIG. 8 is a graph of rate of firmness increase versus blanch temperature for three varieties of carrots, namely Nantes, Danvers and Chantenay.
DETAILED DESCRIPTION OF THE INVENTION
The invention relates to improved methods of food processing and particularly relates to improving the firmness of fruits and vegetables over commercial processes requiring a blanching step followed by sterilization.
The invention relates to a process to increase or maintain the firmness of fruits and vegetables subjected to thermal sterilization processing which comprises;
a) preparing a fruit or vegetable for sterilization processing;
b) blanching the fruit or vegetable at a temperature in the range of from about 125° F. to about 160° F., preferably from 135° F. to 155° F. and most preferably at temperatures from about 140° F. to about 150° F.; wherein the optimum blanching temperature is determined in advance for the fruit or vegetable as follows:
(1) determining the thermal firmness of the said fruit or vegetable as a function of the blanching temperature and blanch time;
(2) determining the rate of thermal firmness increase with blanch time for a series of blanching temperatures;
(3) selecting blanch temperatures or ranges thereof based on (1) and (2) adapted to provide an optimum firmness increase.
c) holding the blanched fruit or vegetable for a hold period of time up to 120 minutes before sterilization processing;
d) sterilizing the product resulting from step (c).
The thermal firmness and the rate of increase of thermal firmness with blanch temperatures and blanch time can be determined by various methods. A preferred method is to determine the firmness of the fruit or vegetable as a function of the blanching temperature and blanch time and determine the thermal firmness therefrom. By plotting the thermal firmness versus blanch time for a series of blanching temperatures, one determines the rate of thermal firmness increase. When the rate of thermal firmness increase is graphed against blanch temperature a curve is obtained which allows one to conveniently select a blanch temperature adapted to provide an optimum firmness increase.
Another aspect of the invention relates to a method for further enhancing the firmness of fruits or vegetables subjected to thermal processing by combining the above process with treatments using food-grade multivalent salt compounds such as for example magnesium chloride, magnesium oxide, magnesium sulfate, calcium chloride, calcium sulphate, calcium oxide, calcium acetate, calcium citrate and the like; food grade acids selected from the group consisting of citric acid, acetic acid, malic acid, tartaric acid, lactic acid and the like or combinations of both.
It is recognized that the invention can be practiced using a variety of blanch temperature and times preceding further processing steps including thermal sterilization. Thus blanch time as used herein is defined broadly as the time the product is held at the blanch temperature and includes a holding time where the blanched product is held for a defined period prior to sterilization processing.
Another aspect of the invention relates to the use of a low blanching temperature sufficient to activate the natural enzyme which promotes firmness in said fruit or vegetable but lower than the temperature which inactivates such enzyme.
DISCUSSION
Kinetic studies have shown that the rates of thermal softening of thermally processed fruits and vegetables is a two-phase process. There is an initial rapid rate of softening which is followed by a much slower rate of softening.
Huang and Bourne (J. Texture Studies, 10:1-23 (1983)) investigated the effect of thermal processing on the firmness of vegetables. These authors measured firmness by placing the sample in a back extrusion cell mounted in the Instron Universal testing machine (cf. Bourne and Moyer 1968). The back extrusion cell used was 10.2 cm I.D. by 12 cm height with a 4 mm annulus. Extrusion speed was 30 cm/min and the downward movement of the plunger was reversed 6 mm from the bottom of the cell. The maximum peak of the recorded force-distance curve, measured in Kilonewtons, was taken as the firmness of the commodity.
The effect of process time on firmness of fruits and vegetables can be shown by plotting log extrusion force vs. process time. Typical softening curves are shown in FIGS. 1, 2 and 3. The softening curve is characterized by an initial rapid decrease in firmness (negative slope) that is almost linear but which curves off into a second straight line with a shallow negative slope at longer process times. Since a first-order kinetic process is represented by a rectilinear plot on a semilogarithmic scale it is evident that simple first-order kinetics does not apply when lengthy process times are used on canned vegetables. The general shape of this curve is typical for all vegetables studied. Fruits show similar thermal softening curves but the initial rate of softening is completed more rapidly than for vegetables.
The shape of these experimental curves is similar to that obtained for the sum of two independent simultaneous first-order processes occurring at different rates. From analogy with kinetic theory the linear portion of the semi-logarithmic curve that is obtained after prolonged heating times (referred to as mechanism 2) gives the apparent softening rate constant for this mechanism. When the linear portion of mechanism 2 is extrapolated back to zero process time and the extrapolated line subtracted from the line above it, the result is a second straight line with a much steeper slope (referred to as mechanism 1) and the slope of this derived line gives the apparent softening rate constant for mechanism 1. This kinetic evidence indicates that the softening of vegetables during thermal processing is composed of two pseudo first-order processes with different rate constants occurring simultaneously. One process is rapid and the other process is slow.
From analogy with kinetic theory for two apparent first order processes we can postulate that the firmness of vegetable tissue is composed of two substrates, "a" and "b" and that substrate "a" softens rapidly by mechanism 1 while substrate "b" softens slowly by a different mechanism (mechanism 2). When the linear portion of mechanism 2 is extrapolated back to zero process time (dotted line in FIG. 1) and this extrapolated line is subtracted from the solid line above it, a second line is obtained as shown by the open circles and dashed line in FIG. 1. The derived dashed line represents mechanism 1 and the slope is its apparent rate constant. The linear portion of the solid line represents mechanism 2 and the slope is its apparent rate constant.
Predicting Process Conditions for Optimum Firmness
As shown in the best mode examples (Table 1, FIG. 6), a plot of the rate of firmness increase (Newtons per minute) versus blanch temperature gives a graph which allows one to select blanch temperatures to produce optimum firmness in the shortest time.
For example, with reference to FIG. 6, suitable blanch temperature ranges for Chantenay variety of carrots can be selected directly from the graph. Broad ranges are those falling within rate of firmness increase (Newtons/minute) of up to about 1.5, i.e. temperatures of 125° F. to 170° F.; preferred ranges are those with rate of firmness increase of 1.50 or greater (i.e. temperatures of from about 135°-155° F.) and most preferred ranges are those having positive rate increase of 2.5-3.0 (i.e. temperatures of from about 140° to about 150° F.).
It is recognized that because of the differences in the food types to be processed, the temperatures and the holding times sufficient to produce the described rate of firmness increase will vary. Generally the best blanching temperature will be broadly in the range of about 120° F. to 160° F. sufficient to provide a fast rate of firmness increase in Newton's/minute; preferably at about 135° F. to about 155° F.; and most preferably at a temperature from about 140° to about 150° C. sufficient to provide the fastest rate of firmness rate increase. It is recommended that experiments be run to establish graphs for each food type to be processed.
A wide variety of vegetables can be processed according to the present invention. These include for example, carrots, beets, potatoes, wax beans, green beans, cauliflower and the like.
Similarly the invention is applicable to a wide variety of fruits such as peaches, apples, cherries, pears and the like.
The following best mode examples are meant to illustrate the invention; they should not be narrowly constructed as to limit the invention.
EXAMPLE 1
Two carrot varieties (Nantes and Chantenay) were washed, topped, diced into 3/8" cubes on an Urschel dicing machine and small pieces removed by passing over a shaking screen. Seven 5 Kg lots of diced carrot were weighed for each blanch temperature. Nine blanch temperatures were used--120°, 130°, 140°, 150°, 160°, 170°, 180°, 190°, 200° F. Each lot was blanched 6 min. in water at the designated temperature, then removed from the water and held with no further heating for a designated hold time, then blanched again 3 minutes at 212° F. in water to stop further enzyme activity and cooled by immersion in cold water. Hold temperatures were 0, 15, 30, 45, 60, 75, 90 minutes.
Sixteen #303 cans were filled from each of the 63 blanch temperature-hold time combinations (7 hold times×9 blanch temperatures). One 60 grain salt tablet was added to each can. The cans were filled with near boiling water, closed, and processed at 250° F. in steam in still retorts with pressure cooling at the conclusion of the designated process time. For each blanch temperature-hold time: 4 cans were processed 40 minutes; 4 cans were processed 60 minutes; 4 cans were processed 80 minutes; 4 cans were processed 100 minutes.
Beginning one week later, the cans were opened and the firmness measured using a back extrusion cell (7.4 cm I.D.×7.8 cm internal height with a 4 mm wide annulus) mounted in an Instron Universal testing machine. This machine plots on a strip chart the force required to extrude the vegetable up through the 4 mm wide annulus between the descending ram and the inside wall of back extrusion cell. This test was replicated eight times for each sample. The maximum force was measured from the Instron chart and the mean value calculated for each treatment.
The logarithm of the mean firmness was graphed against the process time in minutes. A typical series of graphs so obtained is shown in FIG. 4 which gives the data for the 140° F. blanch treatment of Chantenay carrots. The calculated line of best fit to the data points is drawn. The intercept of this line on the vertical axis (firmness at zero process time) is called "thermal firmness".
The thermal firmness data are then graphed against hold time after blanch and the calculated time of best fit is drawn. A typical graph is shown in FIG. 5 for each of 9 blanch temperatures for Chantenay carrot. The slope of each line is measured and this is the rate of increase in thermal firmness for each blanch temperature (shown at the right hand edge of the figure).
The data obtained from FIG. 5 is then graphed against blanch temperature to give FIG. 6. This figure shows that the rate of increase of thermal firmness increases as the blanch temperature rises from 120° F. to 150° F. and then decreases at temperatures above 150° F. In this case, for Chantenay carrot, 150° F. blanch gives the fastest rate of increase in thermal firmness.
Food processors prefer to keep holding times as short as possible. Graphs like FIG. 6 enable processors to determine a blanch temperature-hold time regime that will give a firmer textured product in the shortest possible time.
Table 1 shows thermal firmness values versus hold times in minutes for Chantenay and Nantes variety carrots.
TABLE 1______________________________________Thermal Firmness (Force (N)) Versus Hold Time*______________________________________Chantenay CarrotsHold Time Blanch Temperatures (°F.)(minutes) 120 130 140 150 160 170______________________________________ 0 199.5 195.0 245.5 239.9 251.2 223.915 182.0 234.4 346.7 363.1 269.2 234.430 218.8 316.2 371.5 436.5 263.0 218.845 234.4 316.2 501.2 467.7 302.0 245.560 213.8 323.6 501.2 457.1 346.7 245.575 229.1 309.0 467.7 524.8 371.5 229.190 281.8 331.1 489.8 549.5 389.0 234.4______________________________________Chantenay CarrotsHold Time Blanch Temperatures (°F.)(minutes) 180 190 200______________________________________ 0 213.8 204.2 218.815 213.8 204.2 195.030 223.9 213.8 213.845 234.4 229.1 223.960 218.8 234.4 199.575 229.1 199.5 204.290 218.8 199.5 195.0______________________________________Nantes CarrotsHold Time Blanch Temperatures (°F.)(minutes) 120 130 140 150 160 170______________________________________ 0 169.8 195.0 169.8 204.2 269.2 245.515 269.1 208.9 239.9 309.0 302.0 263.030 275.4 218.7 269.2 346.7 363.1 263.045 281.8 295.1 316.2 380.2 398.1 257.060 338.8 295.1 363.1 446.7 380.2 302.075 309.0 309.0 338.8 457.1 436.5 263.090 426.6 380.2 398.1 467.7 426.6 218.8______________________________________Nantes CarrotsHold Time Blanch Temperatures (°F.)(minutes) 180 190 200______________________________________ 0 223.9 173.8 166.015 186.2 169.8 173.830 213.8 182.0 169.845 229.1 166.0 154.960 204.2 166.0 169.875 213.8 182.0 162.290 223.9 173.8 162.2______________________________________ *Time Interval Minutes between end of blanch and beginning of thermal sterilization.
Table 1 shows that a conventional process of a 200° F. blanch (no hold time) give thermal firmness values of 219N and 166N respectively for Chantenay and Nantes variety carrots with no increase of firmness for holding times of 30 minutes after blanching. However, when the carrots are blanched at 150° F. the respective thermal firmness values are 240N and 204N and these increase to 437N and 346N at 30 minutes hold and to 550N and 460N at 90 minutes hold time. Thus a low temperature blanch temperature plus hold time before sterilization gives a marked increase in firmness. FIG. 5 shows a plot of thermal firmness versus hold time (minutes) for Chantenay carrots. It is seen that firmness increases most rapidly for 150° F. and 140° F. blanched carrots, less rapidly for 130° and 160° blanch. There is only slight increase of thermal firmness with hold time for the remaining blanch temperatures.
FIG. 6 is a graph of rate of firmness increase (newtons/minute) versus blanch temperature for Chantenay carrots. Both FIGS. 5 and 6 allow one to select optimum blanch temperatures and hold times for optimum firmness.
Referring to FIG. 6 it is seen that desirable blanch temperatures for Chantenay carrot are broadly from about 125° F. to about 160° F., preferably from about 135° to 155° F. and most preferably from about 140° to about 150° F.
EXAMPLE 2
In an experiment similar to that of Example 1, Danvers variety of carrots was evaluated using 4° F. increments in blanch temperatures over the range of 140° to 160° F. to more critically define this range. The results are shown in Table 2 and FIG. 8.
TABLE 2______________________________________Firmness of Canned Danvers Carrot (Newtons Force)Hold Time Blanch Temperatures (°F.)(minutes) 140 144 148 152 156 160______________________________________ 0 247.6 206.0 191.0 234.9 259.2 254.315 294.6 333.3 303.2 339.0 337.5 264.730 364.6 327.2 376.5 368.2 359.5 270.745 452.7 444.6 393.7 402.1 394.7 287.460 513.7 452.6 413.0 405.7 352.7 299.675 424.1 449.4 400.5 432.4 372.2 293.390 449.1 474.2 437.3 393.2 364.5 304.1______________________________________
From the above it is seen that the 144° F. blanch temperature gave the fastest rate of increase in firmness; however, temperatures of 140°, 148° and 152° F. also gave high values for the rate of firmness increase. FIG. 8 also shows a rate of firmness increase for two other carrot varieties (Nantes, Chantenay) in the narrower blanch temperature range of 140° F. to 160° F.
EXAMPLE 3
Ten Kg lots of Danvers variety carrots (unpeeled) were blanched 15 minutes and 30 minutes at 150° F. They were then peeled, sliced and diced and sterilized for 24 minutes at 250° F. in #303 cans (21 cans per treatment). For comparison purposes a control was blanched 4 minutes at 212° F. with no hold time before peeling, cutting and sterilization. The firmness results (newton's) are shown in Table 3.
TABLE 3______________________________________Firmness of Canned Carrot (in Newton's Force)TreatmentBlanch Temp. °F. Type Firmness (N) & SD______________________________________ 4 min. at 212° F. (control) slices 214 N ± 11.715 min. at 150° F. slices 255 N ± 10.730 min. at 150° F. slices 328 N ± 14.9 8 min. at 212° F. dices 202 N ± 8.115 min. at 150° F. dices 268 N ± 10.930 min. at 150° F. dices 317 N ± 15.3______________________________________
From Table 3, it is seen that a 150° F. blanch for 15 and 30 minutes gives a marked increase in firmness as compared with conventional processing of 212° F. for 4 minutes.
EXAMPLE 4
In an experiment similar to Example 1, three varieties of snap beans were processed to establish the blanch temperature that gives the fastest rate of increase of thermal firmness. The varieties were Labrador (a green bean), BBL-47 (a green bean) and Bonanza (a wax bean). Example 1 protocol was used except for the following differences:
1) the beans were cut into 11/2 inch lengths;
2) hold times of 0, 15, 30, 45 and 60 minutes were used;
3) blanch temperatures were 120°, 130°, 140°, 145°, 150°, 160°, 170° and 180° F.
The results are shown graphically in FIG. 7 which is a graph of the rate of firmness increase versus blanch temperature. The difference in the maximum rate of firmness increase is noted i.e. 130° F. for Bonanza; 145° F. for BBL-47 and 150° F. for Labrador.
EXAMPLE 5
Heads of cauliflower were broken apart into curds, then blanched 10 minutes at 145° F. in hot water containing 6 grams of citric acid per liter, hold for 20 minutes, then sterilized in No. 303 cans for 22 minutes at 240° F. As a control some of the curds were blanched 4 minutes at 200°-210° F. then sterilized in the same manner with no hold time. The mean value of 8 replicate texture measurements showed that the firmness (newton's force) for the 145° F. blanched product was 127 as opposed to 65 for the control.
EXAMPLE 6
Small white potatoes (B grade) were peeled in an abrasive rotary peeling machine, then blanched 15 or 30 minutes at 145° F., filled into No. 303 cans and sterilized 26 minutes at 250° F. in a still retort. A control batch of potatoes was sterilized at 250° F. for 26 minutes without blanching. The blanched potatoes gave a mean firmness values of 405 and 431N as opposed to 378N for the control.
EXAMPLE 7
Two types of sweet cherries (Sodus-light variety and Duron II--a dark variety) were blanched 5 minutes at 140° F., then held for 30, 60, 120 minutes before being canned in 20 percent sugar syrup and sterilized at 212° F. for 20 minutes. For controls, some cherries were canned with no blanch treatment which is the conventional commercial procedure. Firmness was measured as the force in newtons to push Dunkley cherry pitters simultaneously through 30 cherries. The firmness is shown in Table 3.
______________________________________Treatment, Hold Time Firmness (Newtons Force)Blanch Temp, °F. (minutes) Sodus Durone II______________________________________Control (no blanch) -- 87 97140° F. 30 116 114140° F. 60 114 146140° F. 120 128 164______________________________________
Normally, cherries are not blanched but processed in syrup. It is seen that low temperature blanch (140° F.) with 30, 60 and 120 minutes hold times gives increased firmness.
EXAMPLE 8
Freestone peaches were cut in halves and blanched 20 minutes in water held at 145°-150° F., held for 2 hours and then canned in 25 percent sugar syrup using a sterilization of 20 minutes at 212° F. Control peaches were canned with no blanch treatment which represents conventional commercial practice. Firmness was measured in a back extrusion cell. Four days later another lot of the same peaches were blanched 30 minutes and canned immediately with no hold time before sterilization. The peaches blanched 20 minutes at 145° F. with a 2 hour hold gave a firmness (newton's force) of 221, while those blanched 30 minutes at 145° F. with no hold gave a firmness of 237. Both results exceeded the control firmness of 174N.
EXAMPLE 9
Golden Delicious apples were blanched 30 minutes (9A) and 60 minutes (9B) at 145° F. in water, then peeled, sliced and canned in 20 percent sugar syrup with a sterilization of 20 minutes at 212° F. Control apples were canned with no blanch which is the conventional process. Firmness was measured in the back extrusion cell. The firmness in newton's force, 223 for sample 9A and 265 for 9B, greatly exceeded the control of 89.
EXAMPLE 10
It is well known in the food processing industry that the addition of compounds such as salts of calcium or magnesium impart firmer texture to processed vegetables and fruits. Two vegetables (green beans and potatoes) and one fruit (peaches) were canned with and without 0.07 percent added calcium chloride after being subjected to a conventional commercial blanch or a blanch in the 140°-150° F. range as described in the prior art examples. Firmness results using a back extrusion cell are given in the following table:
TABLE 5______________________________________ Hold Firmness Blanch Time Without WithProduct Temperature (minutes) Calcium Calcium______________________________________Green beans 205° F. -- 218 266(BBL-47) 145° F. 30 476 646Potatoes no blanch (control) 378 362(white) 145° F. 15 405 402 145° F. 30 431 407Peaches no blanch (control) 174 221(Freestone) 20 min. @ 145° F. 120 221 269 30 min. @ 145° F. 0 237 289______________________________________
The results in Table 5 above, show that a firmer product is produced in both green beans and peaches using either a 145° F. or a calcium treatment. A synergistic effect is noted for the combined treatment using both 145° F. blanch and calcium salt. Note the firmness of green beans increases to 646 with calcium and blanch versus 476 (blanch alone) as compared with 266 (calcium only) and 218 (no calcium), for the 205° F. blanch control. These limited tests showed no synergism for potatoes.
EXAMPLE 11
It is known in the food industry that the heating regime needed to sterilize foods with a pH below about 4.5 is much less rigorous than for foods with a pH above 4.5 because heat resistant bacterial spores cannot grow below pH 4.5. This example is to show the effect of the combination of a milder heat sterilization with the addition of sufficient acid to bring the pH of a food having a pH higher than 4.5 to a pH of below 4.5.
Carrots, green beans and cauliflower were given a conventional commercial blanch treatment, or a blanch in the 145°-150° range before processing with, and without, calcium and sufficient acid to reduce the pH below 4.5. The products without the addition of acid were given a commercial high temperature sterilization. The products with added acid were sterilized for 20 minutes at 212° F. which is sufficient to obtain commercial Sterility because the pH was below 4.5. The results are shown in Table 6.
Dramatic synergism is noted for carrots, green beans and cauliflower. For carrots an 8 minute blanch at 212° F. followed by sterilization using both calcium and citric acid gives a firmness of 2168 newton's force. In contrast, a blanch at 150° F. for 15 or 30 minutes using both calcium and citric acid gives firmness values of 3058 and 3485 newton's force. The combination of calcium plus citric acid and 145° F. blanch and 20 min. (212° F.) sterilization gives a 2168 firmness for cauliflower and 4376 for green beans.
TABLE 6______________________________________Effect of Added Calcium and Acid on Firmness______________________________________TreatmentProduct Blanch Sterilization______________________________________carrots, 8 min. at 212° F. 24 min. at 250° F., still retortDanvers 8 min. at 212° F. --sliced 8 min. at 212° F. 20 min. at 212° F., still retort 15 min. at 150° F. 24 min. at 250° F., still retort -- -- -- 20 min. at 212° F., still retort 30 min. at 150° F. 24 min. at 250° F., still retort -- -- -- 20 min. at 212° F.green beans 6 min. at 172° F. 8.5 min. at 250° F. in SteritortRBL-47 4 min. at 145° F. -- (hold 30 min.) -- 20 min. at 212° F., still retortcauliflower 6 min. at 212° F. 22 min. at 240° F., still retort 10 min. at 145° F. -- (hold 30 min.) -- 20 min. at 212° F. in water______________________________________ TreatmentProduct Additives Firmness - Newtons Force______________________________________carrots, none 202Danvers +Ca 279sliced +Ca + citric acid 2168 none 268 +Ca 362 +Ca + citric acid 3058 none 317 +Ca 440 +Ca + citric acid 3485green beans none 336RBL-47 none 454 +Ca + vinegar 4376cauliflower none 65 none 127 +Ca + citric acid 2168______________________________________
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Firmness of processed canned foods including fruits and vegetables has been markedly improved by subjecting the fruit or vegetable to a low temperature blanching step at a temperature in the range of 125° F. to 160° F. and preferably from about 140° F. to 155° F. prior to conventional sterilization. Determination of blanch temperature conditions to produce optimum firmness in the processed food is made by first obtaining firmness values of specific foods at various blanch and hold temperatures and thereafter plotting the rate of firmness increase (Newtons/minute) against blanch temperatures. Preferred conditions, which vary for different foods, are obtained from individual plots for each food. Synergistic improvement of firmness results by combining the low temperature blanching with food grade acid (pH) and/or calcium salt additions.
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RELATED APPLICATIONS
The present patent document claims the benefit of the filing date under 35 U.S.C. § 119(e) of Provisional U.S. Patent Application Ser. No. 60/977,989, filed 5 Oct. 2007, and the benefit of priority to Danish Patent Application No. PA 2007 01439, filed 5 Oct. 2007, the entirety of each of which are incorporated herein by reference.
TECHNICAL FIELD
The invention generally relates to an assembly to be run in conjunction with a perforated or non-perforated well tubular and for being arranged in a wellbore. In particular, the invention relates to a sealing system, such as an anchor or a packer, which includes a triggering section, an energy source section, and an inflatable packer section.
After a well has been drilled, a well tubular is introduced into the well. The well tubular can be a casing or a liner. The outside diameter of the casing is smaller than the inside diameter of the wellbore, providing an annular space, or annulus, between the casing and the wellbore. The well tubular is perforated at one or more zones to allow hydrocarbons to flow into the tubular. Sometimes the well tubular may be sealed off from a part of the annular space. Sealing systems, such as packers or anchors, may be used in the oilfield.
RELATED ART
Packers may be used to seal the annulus between a casing or a liner string and a surface exterior to the string, such as an open wellbore or a casing and often packers are actuated by hydraulic pressure which is transmitted either through the bore of the string, the annulus, or a separate line. Other packers are actuated and controlled by electricity via an electric cable which runs from the wellbore to the surface. Normally the cable is deployed from the ground surface. The packers may also be actuated by a ball dropped from the surface into the well to create a seal. The seal may build up pressure in the wellbore and activate inflation of the packer.
The packer may also comprise swellable materials. GB 2411918 describes a system and method to seal off a space surrounding a well tubular with materials that swell and create a seal when the material comes into contact with a triggering fluid. U.S. Pat. No. 6,302,214 B describes another method for providing annular isolation in a well liner using inflating packers.
Because of the very harsh conditions in oil wells and the remote locations of these wells, which are often thousands of feet below the surface, methods of controlling the operation of downhole devices, such as inflatable packers, may be severely challenged. This challenge may be especially severed if multiple packers are required along a pre-perforated tubular, in which case it may not be possible to seal off the perforations to build up pressure in the wellbore to inflate the packers.
OBJECT OF THE INVENTION
This invention may remove the problems with known techniques and provide a new and more reliable assembly. The assembly may make it possible to inflate packers without the use of an electric cord or hydraulic line between the packers and the ground surface. The ability to activate and control such systems without worrying about electric cable or hydraulic line deployment may give the ability to control production from the wellbore in an easier and more reliable way.
For example, the assembly may be of such a size as to require a larger hole to be drilled or a liner having a smaller inner diameter to be deployed into the wellbore in order to accommodate the assembly. The inner diameter of the assembly may equal the full bore inner diameter of the liner such that the assembly does not obstruct any work string that may be run through the liner.
SUMMARY OF THE INVENTION
The objects of the invention may be achieved by an assembly run in conjunction with a perforated or non-perforated liner, which may be arranged in a wellbore. The assembly may comprise an inflatable packer section that may be expanded by fluid. The inflatable packer section may be provided with valve means for opening and closing of fluid communication into the inflatable packer section; a fluid section being in fluid communication with said inflatable packer section and comprising a suitable fluid for being delivered into said inflatable packer section; an energy section comprising an energy source for the delivering of fluid into the inflatable packer section; a triggering section comprising means for controlling of said energy source and/or for controlling of said valve means thereby being capable of controlling the delivery of said fluid into said inflatable packer section, said triggering section further being provided with means for communication with a triggering device for initiating the expanding of said inflatable packer section.
In one embodiment of the invention the assembly may be run in conjunction with a perforated or a non-perforated well tubular into a wellbore. The assembly comprises an inflatable packer section. The inflatable packer section may be equipped with one or more packers which may be inflated by fluid. The inflatable packers may be used on the outside of a well tubular. However, the packers may be used in any situation or location where down hole packers are required to be inflated.
The packer section may be provided with one or more valves for opening and closing of fluid communication into the inflatable packer section. The energy required for delivering of fluid into the inflatable packer section may be delivered by a suitable energy source, such as by one or more batteries, which may be contained in an energy section. To control the expanding of the inflatable packers in the packer section the assembly may further comprise a triggering section. The triggering section may be capable of controlling the energy source and/or controlling of the valve means. The triggering section may be capable of controlling the delivery of fluid into the inflatable packer section. The triggering section may be a “trigger/detect function” that is capable of controlling the flow of inflation fluid to the packer. The triggering section may release the flow of fluid by opening of valve(s) to the packer, or the triggering section may turn on an electrical pump that transfers the fluid into the packer. The triggering section may be provided with a means for communication with a triggering device for initiating the expanding of the inflatable packer section.
The triggering device may be a pre-set time delay. Alternatively, the triggering device may be based on RFID (radio frequency identification) technology where RFID chips are detected when passing through the assembly. The triggering could also be accomplished in other ways, such as by sending an acoustic signal through the walls of the well tubulars.
In one embodiment of the invention, the assembly comprises a fluid section which is in fluid communication with the inflatable packer section. The fluid section contains a fluid which is suitable for being delivered into the inflatable packer section and thereby expanding the packers. The fluid used to inflate the packers might be cement but other fluids may be used to activate the packer, including brines, one- or two-compound epoxy fluids, gels, inert gas, or other chemicals, including completion fluids. The fluid(s) may include fluid that occurs naturally in a well.
In one embodiment of the invention, the fluid section is adapted for storing of a hardenable two-component fluid system that hardens after mixing of the two fluids. In this embodiment, the two fluids are kept separated in the fluid section until the fluids are delivered into the inflatable packer section. For facilitating the mixing of the two fluids prior to injection into the packer section, the assembly may comprise a connection (mixing) section arranged between the packer section and the fluid section.
Although this description only has discussed a well tubular of circular cross section, the concept may be applicable to different cross sections, such as flat-oval rectangular etc. The assembly may be made as separate modules (sub-assemblies) comprising one or more sections. Alternatively, the assembly may be made as a single unit comprising an energy section, a packer section, a fluid section and a triggering section. Packers may not necessarily have a circular geometry.
Other systems, methods, features, and advantages will be, or will become, apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description, be within the scope of the invention, and be protected by the following claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The systems and methods may be better understood with reference to the following drawings and description. The elements of the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the system. In the figures, like-referenced numerals designate corresponding parts throughout the different views.
FIG. 1 shows an assembly according to an embodiment of the invention;
FIG. 2 shows a schematic drawing of an embodiment of the invention;
FIG. 3 shows a schematic drawing of another embodiment of the invention;
FIG. 4 shows a schematic drawing of yet another embodiment of the invention;
FIG. 5 shows a schematic drawing of a well;
FIG. 6 shows a schematic drawing of a well being equipped with a perforated tubular;
FIG. 7 shows a schematic drawing of a well having a tubular equipped with an embodiment of the invention inserted therein;
FIG. 8 shows the use of an inner tubular together with an embodiment of the invention;
FIG. 9 shows a flow diagram for sealing an annulus.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Tubulars are used for many purposes in the oil production industry. For example, they may be used for reinforcing a well and transporting oil from a reservoir to the surface.
FIG. 1 shows an embodiment of the invention where a tubular 1 of a type that may be used for oil extraction is arranged in an oil well. The tubular 1 may be a casing with a diameter of about 15.24 cm (7 inches). In connection with the tubular wall, means may be arranged for establishing a number of external packers such that gas or oil may be produced from selected areas of the oil reservoir.
The packer may also support a production pipe, tubular or other equipment. These packers may be expanded from the outside of the well tubular. For example, the packers may be expanded outwards to provide a seal with an abutment on the formation or to provide a seal with the inside of another well tubular surrounding the inside tubular. The other well tubular may be a casing surrounding the inside tubular. The material and the energy for such expansion may be supplied from the ground surface, high-pressure injection of cement or the like being performed for expanding the packer.
A part or all of the equipment or material necessary for establishing these barriers formed from packers may be contained in the pipe wall of a well casing or any other tubulars used in an oil well. Such static properties may make the tubular suitable not only for oil production but also may provide for a tubular with external and internal dimensions suitable for insertion between other tubulars in a conventional oil well. Such tubular units may be inserted between conventional pipes as a casing liner.
Depending on where and how the assembly is to be used, the requirements for the volume of cavities for energy storage and other purposes may vary. In response to these variations, the tubular units may be integrated in a single tubular section. Alternatively, the tubular units may be in several tubular sections that are subsequently combined prior to being conveyed down into the well. Where the assembly comprises a number of independent tubular sections, means may be provided for transferring the material, energy and/or electronic signals necessary for the expansion process between the tubular sections.
A tubular with an essentially unchanged flow area may be achieved by storing in the tubular wall the means necessary for establishing the packer. A number of these prepared tubular sections may be introduced into an oil well without significantly influencing the well operation.
FIG. 1 further shows cavities provided in the tubular wall. In those cavities equipment may be arranged for establishing an external packer. The tubular section 1 comprises a number of tubular sections, each of which comprises constituent components for establishing a packer on the tubular outside. The assembly of FIG. 1 comprises the following sections:
A tubular section 10 (trigger section) that contains an activator unit initiating and controlling the expansion of the packer (trigger sub); A tubular section 2 (energy section) that supplies the requisite energy for expanding the packer; A tubular section 5 (packer section) that contains one or more expandable packer(s); A tubular section 3 (fluid section) that contains a suitable fluid, such as a two-component system that sets following admixture, for being injected into the expandable packer for establishment of a barrier; A tubular section 4 (mixing section) that contains means for mixing the fluids.
Tubular sections 10 , 2 , 5 , 3 , 4 may be constituents of a casing, liner or any other tubular element that partakes in an oil well.
Speed, time and extent of the inflation of the packer may be controlled by the trigger unit in the tubular section 10 . By providing the assembly with a trigger unit (as will be explained in further detail below) the assembly according to the invention may be conveyed down into an oil well in its non-activated state and then be activated to establish a barrier on the outside of the tubular when there is a need. The need may arise due to ingress of water or to delimit a part of the well. The establishment of a packer may also be due to a need for supporting a production tubular. These two scenarios are fundamentally different since, as opposed to the need for preventing ingress of water, which often occurs unpredictably, the need for establishing a supportive packer is usually predictable. The choice of a suitable trigger unit may be based on this need.
Thus, one embodiment of the invention comprises a trigger unit containing a timer that starts the expansion after a predetermined period of time. This embodiment may be particularly suitable for assemblies that comprise a packer unit capable of supporting a tubular section. The assembly may be introduced in a non-activated state into the well at the site where support is desired. The trigger unit may activate expansion of the packer. A timer may be set in advance to initiate the expansion of the supportive packer after a suitable period of time (after which experience has shown the tubular section to be properly located).
According to a further embodiment the expansion may be controlled by a trigger unit that initiates expansion only when it receives a signal. The signal may be based on radio technology, such as RFID (Radio-Frequency Identification) technology, where a sensor is capable of (at a distance of upwards of several meters) detecting and identifying an RFID tag. By using RFID technology, a high degree of reliability may be obtained such that the assembly does not unprovokedly initiate an expansion of the packer. Furthermore, several independent assemblies may be introduced into the well without having concerns about one or more assemblies shutting off productive areas due to malfunction.
Several independent assemblies that include RFID technology may be arranged in sites where there is a concern that, at any point in time, it may be convenient to establish a barrier against ingress of water. When such need arises, the relevant assembly may be activated by pumping the electrode specific to that particular assembly from the surface and down through the tubulars. When the trigger unit of the assembly detects that the relevant RFID tag passes through the tubular, it may initiate and control the expansion of the packer. In this manner, the costs of blocking water-producing areas may be reduced. These costs may be very high, since, it is generally necessary to first discontinue the oil recovery and then lower suitable equipment into the well. When several mutually independent RFID-based systems partake as elements (in any number) inserted between the conventional tubulars of a well, one option may be to selectively activate a number of assemblies by pumping liquid containing RFID electrodes from the surface of the well and down through the tubulars.
According to a further embodiment of the invention, the trigger unit may be based on acoustic transmission of data between the surface and the trigger unit 10 . The acoustic transmission may occur through acoustic signals transmitted through the tubulars of the well. The trigger unit 10 may be provided with recording equipment (not shown) which is able to read physical parameters in the well, such as temperature, pressure or the presence of water. For the recording equipment to function optimally, the equipment or parts of the equipment may be arranged on the outside of the tubular. By providing the trigger unit with recording means and a means for acoustically transmitting data between the recording means and the ground surface, it is possible not only to monitor the well, but also to establish barriers in other suitable places as soon as the need arises. This embodiment of the invention may be combined with other methodologies for transmitting signals between the trigger unit 10 and the surface above the well. For instance, it may be advantageous if the trigger unit 10 has integral means for acoustic transmission of well parameters to the surface and simultaneously means for activating the expansion means of the packer by means of both acoustic signals and signals provided by means of RFID-tags.
The assembly may comprise a section 2 that features means for establishing the energy requisite for operating the assembly. Such means for establishing energy may rely on batteries, compressed gas, or they may utilise the pressure differences between well pressure and atmospheric pressure.
The assembly may also comprise a tubular section 3 (fluid section) in which a fluid is contained in a cavity in the wall of a tubular section suitable for expanding one or more packers (packer section) 5 .
As shown in FIG. 1 , a connection sub is arranged between the packer section 5 and the fluid section 3 . The connection sub may be where two-component epoxy systems are mixed prior to being injected into the packer. The expansion of the packer need not be limited to two-component glue systems. The expansion may also be based on a single fluid that makes the packer expand, such as by means of a swellable material.
A tubular may be established in which all the units are incorporated into the wall of the tubular without significantly and adversely affecting the cross-sectional area of the tubular. In one embodiment of the invention where the cross-sectional internal area remains unchanged (fullbore), the assembly comprises sections of the following lengths:
Trigger section: 0.91 meters (36 inches);
Energy section: 1.27 meters (50 inches);
Fluid section: 3.20 meters (126 inches);
Mixing section (connection sub): 0.30 meters (12 inches);
Packer section: 2.13 meters (84 inches).
In another embodiment of the invention, the internal diameters of the tubular sections 10 , 2 , 3 , 4 , 1 , 5 may be slightly reduced, but the sections may still partake as conventional well tubulars. In this embodiment, the assembly comprises sections of the following lengths:
Trigger section: 0.91 meters (36 inches);
Energy section: 0.66 meters (26 inches);
Fluid section: 1.47 meters (58 inches);
Mixing section (connection sub): 0.30 meters (12 inches);
Packer section: 2.13 meters (84 inches).
FIG. 2 shows a tubular section containing an assembly for establishing a packer on the outside of the tubular and, on the left in the Figure, the components of the assembly are shown incorporated into the tubular wall 21 . The tubular 20 comprises several longitudinally extending cavities in which means are provided for establishing the barrier.
The injection of fluid into the packer takes place by means of a piston 27 that may be displaced by means of pressurized gas or an electric pump contained in the energy section 25 . However, systems for performing such injection of the fluid may assume a wide variety of configurations and it follows that the invention should not be limited to the above-mentioned embodiments.
The activation of the assembly shown in FIG. 2 is accomplished by means of the trigger unit 26 arranged between the fluid section 23 and the energy section 25 . The trigger unit 26 may control a valve (not shown) arranged between the energy section 25 and the fluid section 23 .
Similar to other embodiments, the expandable packer may also be incorporated into the wall of the tubular. The wall of the tubular may be provided with suitable openings on the outside through which the packer expands. In one configuration, the packer is not arranged into the tubular walls, but the packer's valve arrangement is. The valve system of the packer may be valve system 22 . FIG. 2 shows that the openings are constituted by holes 22 , but the openings may also have other configurations.
FIG. 3 shows a further embodiment of an assembly according to the invention. The trigger unit 26 is arranged between the section containing the expandable packer's fluid injection valves 22 and the section 23 containing fluid. By arranging the units in this way, a very accurate dosing of fluid into the expandable packer may be accomplished.
FIG. 4 shows an alternative embodiment of the invention, in which the assembly does not contain a section with fluid. Instead, the assembly includes a tubular section 31 , in which means are provided to enable expansion of the packer(s) through pumping by means of the liquid(s) that are present in the oil reservoir. For instance, those means may be an electric pump 34 (not shown in detail) that pumps liquid from an opening in the tubular 32 to the packer section 5 via a passage 33 configured in the wall of the tubular. The assembly may be configured with a packer that contains (or is supplied with) a swellable material.
FIG. 5 shows a horizontal well 40 drilled into the formation 41 . FIG. 6 shows that the well 40 has been drilled and a well tubular 42 is introduced into the well. The well tubular may be a casing or a liner. The outside diameter of the casing is smaller than the inside diameter of the wellbore, providing thereby an annular space 43 , or annulus, between the tubular and the wellbore. The well tubular is perforated 42 at one or more zones to allow hydrocarbons to flow into the tubular. In order to stimulate the well fluid, acid may be discharged into the annular space through these openings configured in the wall of the tubular 42 . One or more assemblies according to the invention (not shown in FIG. 6 ) may be run in conjunction with the well tubular 42 .
FIG. 7 shows how assemblies according to the invention may be used to establish an isolated zone 44 between two packers 5 . The assemblies 1 may have been activated by two RFID chips 48 , 49 which may have been pumped from the surface and down through the tubular.
FIG. 8 shows an embodiment where an inner tubing 45 is introduced into said well tubular thereby providing a gap 47 between the inner tubing and the well tubular 43 . The inner tube 45 has means 50 for sealing off the specific part of the gap 47 being in fluid communication with the isolated zone 44 established between the expanded packers 5 . FIG. 8 shows the inner tube 45 provided with a closable opening 46 that may be operable from the surface. Thus the inner tube 45 may be chosen to be in fluid communication with the isolated zone 44 between the packers 5 . By establishing several independent arrangements in a well, such as shown in FIG. 8 , it may be possible to open up or close off selected parts of the well.
FIG. 9 shows a flow diagram 900 for an exemplary embodiment of a method for sealing an annulus. A well is first drilled into a formation ( 902 ). The well may be drilled according to conventional systems and methods. An illustration of an example drilled well is presented in FIG. 5 . Next, a tubular is introduced into the wellbore of the well ( 904 ). The tubular may be a well casing or a well liner. The introduction of the tubular may create a gap between the tubular and the surrounding formation in the wellbore. An illustration of an example tubular introduced into the well is presented in FIG. 6 .
Annulus sealing assemblies are introduced into the wellbore ( 906 ). The annulus sealing assemblies may be one or more of the assemblies presented in FIGS. 1 , 2 , 3 , or 4 . The annulus sealing assemblies may be all the same type of assembly, they may all be different, or they may be some combination of types of assemblies. The annulus sealing assemblies may be introduced concurrently with the tubular into the wellbore or at a later point in time than the tubular. For example, the annulus sealing assemblies may be attached to the inner or outer surface of the tubular prior to introduction into the wellbore. Alternatively, the annulus sealing assemblies may be components of the tubular.
The well is then stimulated ( 908 ). An acid or aggressive fluid may be introduced into the well through the tubular to stimulate the well. The acid or aggressive fluid may reach the formation by passing from the inside of the tubular to the annular space between the tubular and the formation through openings in the tubular.
A section of the annular space between the tubular and the formation is sealed off ( 910 ). The section may be sealed off by activating the annulus sealing assemblies. An illustration of an example sealed-off annular space is presented in FIG. 7 . It may be advantageous to seal off a section of the annular space where the section evidences a high concentration of contaminants. The contaminants may include sand, soil, ground debris, water, heat, and/or pressure. The section may alternatively be sealed off to provide additional structural support for the tubular.
An inner tubing is introduced inside the tubular ( 912 ). The introduction of the inner tubing produces a gap between the inner tubing and the tubular. The inner tubing may include or comprise annulus sealing assemblies. The annulus sealing assemblies for the inner tubing may be the same as or different from the annulus sealing assemblies for the tubular.
An annular space between the inner tubing and the tubular is sealed off ( 914 ). The annular space may be sealed off by triggering the annulus sealing assemblies for the inner tubing. An illustration of the sealed-off annular space between the inner tubing and the tubular is presented in FIG. 8 .
The inner tubing may have one or more closable openings in its surface. The closeable openings may be opened or closed ( 916 ). The closable openings may be operable from the surface to establish or cut off fluid flow between the inside of the inner tubing and the annular space between the inner tubing and the tubular. Because the annular space between the inner tubing and the tubular may be open to the annular space between the tubular and the formation through perforations in the tubular, the closable openings can regulate fluid flow between the inside of the inner tubing and the fluid in the annular space outside the tubular. Thus, the closeable openings can selectively access oil, gas, or other fluids from the formation and/or selectively deliver acid or aggressive fluid to stimulate specific sections of the formation. Note that in this embodiment, the steps may occur in varied order.
While various embodiments of the invention have been described, it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible within the scope of the invention. Accordingly, the invention is not to be restricted except in light of the attached claims and their equivalents.
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An assembly arranged in a well bore and run in conjunction with a perforated or a non perforated liner has an inflatable packer section prepared for being expanded by fluid and a valve device for opening and closing of fluid communication into the inflatable packer section. The assembly also has a fluid section connected to the inflatable packer section. The fluid section holds a fluid that is delivered into and used to inflate the inflatable packer section. An energy section in the assembly contains an energy source for delivering the fluid from the fluid section into the inflatable packer section. A triggering section includes a control for the energy source and/or the valve device. The triggering section can control the delivery of the fluid into the inflatable packer section. The triggering section also includes a communicator that signals a triggering device for initiating the expanding of the inflatable packer section.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a bar guideway for the flat strip bar of a bar closure which in particular is provided for installation in the fillet gap of sheet metal cabinet doors and in which the flat strip bar does not have any or has only tediously disassemblable locking means such as pins, hooks, roll pins or double roll pins.
2. Prior Art Background
A bar guideway for the flat strip bar of a bar closure, which is arranged in the fillet gap of sheet metal cabinets, is known from European Patent 01776890. The bar guideway described there is provided with recesses and functions to guide the bars and for locking, e.g. for accepting a peg carried by the body of the cabinet upon the sheet metal cabinet door being closed. Subsequently, an axial section of the flat strip bar slides onto said bar guideway and brings about locking. This yields a relatively stable locking. However, this kind of locking requires very precise installation of the bar guideway and requires the bolt to be received by the bar guide, so that the door can be closed properly. In addition, another disadvantage is that locking can only take place at the ends of the bar should the bar of the bar closure be intended for right as well as for left closing doors. For example, greater sheet metal cabinet heights and greater loads, through the explosion pressure of arcs within the switch cabinet. It can, however, become necessary, to fix the door panel not only above and below, but also at intermediate levels, which, with the known bar closure, cannot be realized at all or only by accepting other disadvantages such as nonsymmetry cf the bars of the bar closure.
A further disadvantage of the known bar guideway is that the bar can only be introduced into the guideway by sliding it axially from above or below. With particular constructions of the bar closure, this can lead to difficulties or it can be completely impossible.
A further disadvantage of the subject matter of the above-mentioned publication is that no explanation is given regarding the method by which the bar guideway is fastened on the door panel.
SUMMARY OF THE INVENTION
It is the task of the invention to further develop a bar guideway so that the kind of fastening on the door panel becomes clear. In particular, the bar guideway does not need to be slid onto the bar axially, nor does the bar need to be slid axially into the bar guideway, but rather the bar guideway can be slid laterally onto the bar. The bar guideway can be clipped on or applied in a similar fashion, so that sliding the entire bar axially through the bar guideway become superfluous.
This task is solved by implementing one of two alternative constructions. In the first alternative, the bar guideway has an L-shaped cross-section of resiliently elastic material such as synthetic material The bar guideway has a pair of legs extending from a corner area so that the legs and corner area together form the L-shaped cross-section. One leg has a fastening hole and the other leg has a free edge. Extending from the free edge and from the corner area are projecting guide rails each with a hook-shaped profile, which forms a guide track in which is guided the flat strip bar. The second alternative, fulfills the same task. However, the bar guide comprises a first L-shaped corner piece, of which is provided with a first aperture or cut for receiving the set bolts for fastening the screws on the door panel corner and the other leg forms a guideway for the surface of the flat strip bar directed away from the door panel corner. The bar also comprises a second L-shaped cornerpiece, one leg of which is provided with a second aperture for fastening with screws to the first angle, and the other leg of which forms a guideway for the other surface of the flat strip bar lying toward the door panel corner and forms at the end a hook reaching around the one narrow side of the flat strip bar.
Both solutions have the advantage that the flat strip bar they are to carry does not need to be slid through, but can be stuck onto the bar laterally and subsequently be installed on the door panel. In many applications this simplifies installation of the flat strip bar closure. Thus, the installation of flat strip bar closures becomes possible, which, due to the construction of the flat strip bars, cannot even be pushed through guideways.
Both approaches permit different embodiments. In the kind of bar guideway mentioned first, bilateral reinforcing walls can be arranged within the frame surrounded by the legs, which is of an advantage, if the bar guideway is injection molded of synthetic material.
According to a yet different embodiment, it is desirable for foot rails, which continue and widen the walls, to extend from the outer surface of the leg carrying the fastening hole. This ensures improved contact when fastening with welding bolts, because welding material residues do not become a nuisance.
The hook rail fastened at the angle corner region can have an offset region of lesser cross section. The decreased cross section could, for example, be formed by a triangular groove, with the tip of the triangle lying near the associated inner corner of the guide track. In particular, the hook rail fastened on the angle corner region could form a resilient clip, the one end of which braces itself on the fastening surface for the bar guideway.
According to a yet different embodiment, the bar guideway may be formed in such a way that the outer angle surface around the fastening hole forms an undercut for receiving the bore ridge (for screw fastening) or welding material (for welding bolt fastening). Preferably, the leg forming the guide track has a greater axial extent than the leg provided with the fastening hole.
According to yet another embodiment, the reinforcing walls and/or the side edges of the leg or the extended guide track may form a stopping surface for a locking part carrying the bar. However, a stopping surface can be provided which also represents an alignment projection for a locking part carried by the door frame. The door edge has a labyrinth for water-repelling ventilatability. The door edge of the door (instead of a rubber seal which acts as stop) never makes contact directly with the surface of the unlacquered frame which would otherwise possibly damage the lacquer. Instead, a defined distance by the stopping devices is maintained.
The alternative construction likewise permits several variations, which can be used to advantage. The second aperture or the cut could be arch-shaped and have a radius significantly greater than that of the fastening bolt in order to receive here flashing, welding residues or the like and, in this way, effect full contact of the bar guideway on the door panel. The advantage of the arch-shaped cut (compared to a round hole of identical radius) lies in its simple installation: the first L-shaped corner piece can subsequently be pushed under the second L-shaped corner piece, which is already placed on the screw bolt or similar means. Before the second L-shaped corner piece is inserted, the flat strip bar can still be slid under the hook of the second angle.
Furthermore, for more precise guidance of the one narrow edge of the flat strip bar, it is, favorable if the second L-shaped corner piece forms in its second leg, which is directed away from the door panel plane, a cut, from which extends a guide lug or a guide web for the one narrow side of the flat strip bar. This guide lug or guide web can be created by bending the leg end inward by 90° in the region of the cut or by cutting all the way into the other leg and bending out an auxiliary leg parallel to the second leg but by a shorter fashion and displaced toward the inside. The two parts may be punched out of metal, injection molded of light metal, cast, or partially injection molded of synthetic material.
BRIEF DESCRIPTION OF THE DRAWINGS
Below, the invention is explained in greater detail in conjunction with embodiments represented in the drawings, which show:
FIG. 1 is a side elevational view of the fillet gap of a sheet metal cabinet door as viewed from behind with a flat strip bar closure installed in this fillet gap as an explanation of the application of the bar guideway according to the invention;
FIG. 2 is an axial sectional view along line 2--2 of FIG. 1;
FIG. 3 is an axial sectional view along line 3--3 of FIG. 1;
FIG. 4 is an axial sectional view along line 4--4 of FIG. 1 as an illustration of a locking device for a flat strip bar, so that it is not slidable through the guide device;
FIG. 5 is an axial sectional view along line 5--5 of FIG. 1 to represent the embodiment of a bar guideway according to the invention used in FIG. 1;
FIGS. 6 A-C are respectively side elevational, axial sectional and bottom views of the bar guideway according to FIG. 5;
FIGS. 7 A-C are views similar to those of FIGS. 6A-C but for another embodiment;
FIG. 8 is a sectional representation of still another embodiment, but which is similar to FIG. 5;
FIG. 9 is a plan view of an embodiment of the bar guideway according to FIG. 6C in a modification;
FIG. 10 is a representation similar to FIG. 5 of another embodiment of a bar guideway, which consists of two parts;
FIG. 11 is the upper part of the FIG. 10 bar guideway in a separate representation;
FIG. 12 is a plan view of the lower part of the FIG. 10 bar guideway;
FIG. 13 is a plan view of a somewhat modified lower part of FIG. 12; and
FIG. 14 is a representation of bar guideway similar to FIG. 10 with the modified lower part according to FIG. 13.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows the fillet gap or channel 10 of a sheet metal cabinet door 12 in a view from behind the door 12. A bar closure 14 arranged in this gap consists of a lock 16, from which a flat strip bar 18 extends in this fillet gap 10. The flat strip bar 18 is supported within the lock 16 and is also displacably supported in a bar guideway 20 on the door panel 12. The sheet metal cabinet door 12 is, as shown in FIG. 3, articulated in a known manner with joint hinges 22 and with the body of the cabinet 24, which, in turn, utilizes the other fillet gap 11, which is formed between the outer edge 26 of door 12 and a sheet metal section 30 welded to the inside of the door panel 12 and a sheet metal section 30 welded to the inside of the door panel 12 and sealed by a seal 28. In sheet metal cabinets, which have a fillet gap 10, 11 of this nature, it is customary that in the fillet gap for the closure one or, if use of sinkable pivot lever closures is planned, two rectangular apertures 32 and 34 are arranged symmetrically to the horizontal door center 36.
As shown in FIG. 2, which represents an axial sectional view along line B--B of FIG. 1, a hook-like projection 38 is screwed to the body of the cabinet 24, into which, when the bar closure is closed, a double roll pin 40 carried by the closure bar penetrates and forms a lock arrangement 42. In the sectional view C--C through this locking arrangement (see FIG. 4), it can be seen that the bar 18, which is rectangular in cross section and formed of flat strip material, carries a peg 44 in press fit, which holds bilaterally rotatable rollers 46. The rollers have so much play that they are readily rotatable but cannot slide off the peg 44; this is due to the presence of a head 48 on the one side of peg 44, and a flange (beading) 52, which is generated on the opposite side of the peg after the peg and rollers have been installed.
The hook 38 is provided with a slit 50 for receiving the bar 18, within section C--C of FIG. 4. The hook has a U-shaped profile, with the web of the U having a threaded bore, into which a setscrew 51 can be screwed in order to fix the hook 38. The hook 38 may also have a safeguard against rotation. For example, a prismatic aperture in the body of the cabinet 24, into which corresponding projections of the hook can be slid forming a safeguard against rotation.
FIG. 5, which is the sectional view D--D according to FIG. 1, shows a bar guideway 20, in which a part, still to be described in detail and preferably injection molded of synthetic material, is arranged in a rotation-proof fashion with a stud bolt arrangement in the corner gap of the fillet gap 10. The part is formed so that the flat strip bar 18, after having been previously bent away from projection 54, can be slid into the guideway. Subsequently, the fastening nut 56 of the welding bolt 58 can be tightened, which presses the projection 54 against the bar 18 forming a safeguard. The guideway 20 can also be arranged on the other side of bar 18 outside the corner region of the door panel where it is occasionally difficult to access for welding work. In this case the bottom support of the bar guideway 20 could have small projections which would increase friction, so that the separate rotation safeguard, advisable for welding bolt fastening, is achieved. In FIGS. 6A-C, the bar guide part, which is injection molded of synthetic material and used in FIG. 5, is again emphasized more clearly. As can be seen, the bar guideway 20 consists of a base angle 60 of resiliently elastic material, in particular synthetic material, the one leg 62 of which has a fastening hole 64 and the other leg 66 of which has at its edge 68, which is free in the upward direction, and in the angle region 70 between the two legs 62, 66 one projecting rail 72. Each rail has a hook-shaped profile and, in this way, forms a guide track 76 for the flat strip bar.
Reinforcing walls 78 are arranged on both sides of the fastening hole 64 within the angle, which if produced on an elastic synthetic material, lend sufficient strength to the overall arrangement.
The hook-shaped rails 72, 74 are bent obliquely at their hook ends toward the outside and facilitate through their funnel shape the insertion of the flat strip bar. As a supplement, as shown in FIG. 6B, the hook rail 74 fastened at the angle corner region 70 can have an offset of lesser cross section, with this lesser cross section being formed, for example, by a triangular groove 80, with the tip of the triangle lying near the associated inner corner 82 of the guide track 76. During insertion, before installing the base angle 60 or at least before tightening the particular fastening screw, the hook rail 74 can be folded away in the direction of arrow 84 and the bar slid into the upper hook. Subsequently, the rail 74 (which represents the projection 54 according to FIG. 5) can be folded back again, whereupon the base angle 60 is fastened in the region of the corner. The fold-away hook 74 is simultaneously held firm by the bottom surface (see FIG. 5) of the door panel.
As shown in FIGS. 7A-C, which is an embodiment similar to FIGS. 6A-C, foot rails 88 continuing and widening the walls 78 can extend from the outer surface 86 of the leg 62 carrying the fastening hole 64. The advantage of this construction is more space for receiving the ridge or welding residues is available, when welding bolts are used for fastening. I n FIG. 8, which is an embodiment in a model similar to that of
FIG. 6 A-C, a base angle for a bar guideway is shown in which the hook rail fastened on the angle corner region 70 forms a resilient clip 90, the end 92 of which braces itself on the fastening surface (not shown here) for the bar guideway, so that the swing-away motion cannot take place in the direction of arrow 84. However, this clip-like design 90 is so elastic, that even after installation, sufficient resiliency exists in order to slide the flat bar in at the top and subsequently achieve over the run-up surface of clip 90 insertion at the bottom, with the clip giving so far, that the bar clicks in behind the corner 94 and, subsequently, is held tight.
FIG. 9 shows that the leg 66 forming the guide channel may extend greater axially than the leg 62 provided with the bore. The bar guideway is preferably formed so that the outer angle surface again forms around the bore an undercut 96 for receiving bore ridges (when fastening takes place with screws) or welding material (when fastening is done with welding bolts).
In FIGS. 10 to 14 a bar guideway is shown consisting of two parts.
The first part comprises a first angle 110 with one leg 114 provided with an arch-shaped cut 116 for fastening with screws in the corner gap of the door panel to receive the fastening bolt 58, and the other leg 118 forms a guideway for the surface 120 of the flat strip bar 18 directed away from the door panel corner gap. The second part comprises a second angle 112 (FIG. 11) with one leg 122 provided with a round bore 124 for fastening with screws to the first angle 110, and the other leg 126 forming a guideway for the other surface 128 of the flat strip bar lying toward the door panel corner gap. At the end of this other leg forms a hook 132 encompassing the narrow side 130 of the flat strip bar 18.
As is readily apparent in FIG. 12, the arch-shaped cut 116 has a radius substantially greater than that of the round aperture 124 of angle 112 adapted to the radius of the fastening bolt, again for the purpose of receiving flashing, welding residues or the like and to permit full contact of the angle on the fastening surface within the corner gap of the door panel. As FIG. 10 shows, the bend 134 of the door panel 12 provides a stopping surface for the free edges 136 of the two angles 110, 112 and an excellent safeguard against rotation in connection with the tightened screw bolt connection 58. A closed aperture (round hole) with identical radius can also be provided instead of the arch-shaped cut. However, in that case, installation of both angles can only take place simultaneously (with the flat bar inserted). The cut permits installation of the second angle, flat strip bar, and first angle in separate steps, which can be of advantage.
As seen in FIG. 13, the first angle 110 can form a cut 140 in its second leg 118 directed away from the door panel plane. From this cut extends a guide lug or guide web 142 (FIG. 12) or 144 (FIG. 13) for the other narrow side 146 of the flat strip bar 18. The guide lug or the guide web can be generated by bending the leg end in the region of the cut inward by 90° (see FIG. 13 and 14), or by cutting all the way into the other leg 136 and bending out an auxiliary leg parallel to the second leg 118 but shorter and displaced toward the inside (see FIG. 12 and FIG. 10). The advantage of both constructions is that the flat strip bar 18 receives a somewhat greater distance from the door panel 12, which can be of advantage with respect to other devices of the bar closure.
The two parts 110, 112 shown in FIGS. 10 to 14 can be punched out of metal or produced of synthetic material.
In general, it is favorable to attach the bar guideway 20 as near as possible to one of the closure hooks 38, in order to keep as small as possible the lever forces acting upon the flat strip bar. If the two parts 20, 38 respectively are moved even closer to each other as is shown in FIG. 2, the lower part 148 of hook 38 braces itself on a corresponding bearing surface 150 of the bar guideway 20 and results in a particularly precise guidance of the door panel with respect to the door frame. The guidance is as precise as is obtained with different means in prior art. Particularly, the hook 38 is clamped between the surface 150 of the bar guideway 20 and the double roll pin 40, so that an extraordinarily shake-proof closing effect is achieved. Depending on the construction of the bar guideway 20, the reinforcing wall 78, the side edges of leg 68 or, in FIG. 9, the front face of the extended guide channel should be considered as a bearing surface.
Special alignment projections, which extend from the door frame 24, can be provided instead of hook 38 as an alignment device, which, in connection with the bar guideway 20, accomplishes fixing the door panel with respect to the door frame in the closed state.
Bar guideways of the described kind are used in the electrical industry for building closures for switch cabinets manufactured of sheet metal.
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A bar guideway for the flat strip bar (18) of a bar closure (14) is described which is intended for installation in the fillet gap of sheet metal cabinet doors, and the flat strip bar (14) does not carry any or only tediously dissemblable locking means such as pins, hooks, roll pins or double roll pins. According to the invention, the bar guideway (20) forms a base angle (60) of resiliently elastic material such as synthetic material, whose one leg (62) has a fastening hole (64) and whose other leg (66) has one projecting rail (72 respectively 74) each. Each rail has a hook-shaped profile, and thereby forms a guide track (76) for the flat strip bar (18) (FIG. 1 and 6).
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[0001] This application claims priority based on provisional application 60/584,332 filed Jul. 1, 2004
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates generally to sports equipment but more particularly to a dumbbell having an angled bar to favor motion by a user.
[0004] 2. Background of the Invention
[0005] Dumbbells have been around for centuries, but with the ever increasing variety of exercise moves being created, some flaws in the design of current dumbbells are beginning to show. Due to body configuration, more particularly in the way hands grab dumbbells, some moves are awkward or have the weights of the dumbbell interfere with body motion because of the way the hand has to grasp the bar between the weights.
[0006] Some effort has been made in that direction by having handles incorporated along or as replacement to the bar between the weights such as in U.S. Pat. No. 460,270, U.S. Pat. No. 734,062 and U.S. Pat. No. 1,917,566.
[0007] Also, but more specifically for barbells, kinks have been incorporated in the bar such as in U.S. Pat. No. 2,508,567, U.S. Pat. No. 2,722,419, U.S. Pat. No. 4,288,073. Also, the use of an offset bar is disclosed in U.S. Pat. No. 4,288,073.
SUMMARY OF THE INVENTION
[0008] In view of the foregoing disadvantages inherent in the known devices now present in the prior art, the present invention, which will be described subsequently in greater detail, is to provide objects and advantages which are:
[0009] To have a dumbbell that does not interfere with the body or with body motion.
[0010] To have a dumbbell that fits ergonomically.
[0011] To have a dumbbell that is easy to use.
[0012] To have a dumbbell with a shorter bar.
[0013] To attain these ends, the present invention generally comprises a bar that is set non perpendicularly to the weights of the dumbbell and has added features such as indicias that a user can quickly see in order to know which direction the dumbbell is for appropriate grasping as well as footings which orient the dumbbell so as to make it easy to use. Since the bar reorients the weights so that they do not interfere with the body, a shorter bar can be used which brings each weight closer to the other.
[0014] There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are additional features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto.
[0015] In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.
[0016] As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.
[0017] Further, the purpose of the foregoing abstract is to enable the U.S. Patent and Trademark Office and the public generally, and especially the scientists, engineers and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application. The abstract is neither intended to define the invention of the application, which is measured by the claims, nor is it intended to be limiting as to the scope of the invention in any way.
[0018] These together with other objects of the invention, along with 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 the specific objects attained by its uses, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENT
[0019] FIG. 1 a Side view of the prior art with user arm.
[0020] FIG. 1 b Side view of this invention with user arm.
[0021] FIG. 2 Isometric view of the invention.
[0022] FIG. 3 a Side view of the invention.
[0023] FIG. 3 b Front view of the invention.
[0024] FIG. 4 a Front view of the invention with swiveling bar assembly.
[0025] FIG. 4 b Side view of the invention swiveling bar assembly.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0026] FIGS. 1 a and 1 b show the differences between a dumbbell ( 10 ′) of the the prior art and a dumbbell with angled bar ( 10 ) wherein a bar ( 12 ) is set at an angle other than perpendicular in relation to the weights ( 14 ). There are two types of dumbbells, those with integral weights and those with releasably attached plates. In this description, the terms weights will be used to describe weights or plates interchangeably. The dumbbell with angled bar ( 10 ) improves the way a user can hold it without interfering with, as per fig 1 a , the forearm ( 11 ) for example.
[0027] To make it easier for a user to always grab the dumbbell with angled bar ( 10 ) correctly, the weights ( 14 ) have a stabilizing element ( 15 ) which help the dumbbell with angled bar ( 10 ) rest stably on a surface. The stabilizing element ( 15 ) extends peripherally from at least one weight ( 14 ) in a configuration which turns the round shape of the weight ( 14 ) into a nearly to totally flat surface shape. The weights ( 14 ) can be of a larger diameter than conventional dumbbell weights ( 14 ′) since the angle eliminates potential interference with forearms ( 11 ) as is the case with standard dumbbells ( 10 ′) because the way a user holds them makes the weights ( 14 ′) not parallel with the forearm ( 11 ), whereas in the case of dumbbell with angled bar ( 10 ), the weights ( 14 ) are parallel to the forearms ( 11 ) and as such, will never touch the forearm ( 11 ) no matter how large they are.
[0028] Because one side of the bar ( 12 ) is higher than the other side, there is a specific direction in which the dumbbell with angled bar ( 10 ) is to be grappled and to help in that matter, an indicia ( 16 ) is put either on the weight ( 14 ) or on the bar ( 12 ) in order to eliminate second guessing.
[0029] As described from FIG. 1 to FIG. 3 the invention appears to describe a proprietary dumbbell with proprietary designed weights ( 14 ) having offset holes ( 18 ) in the case of a dumbbell with interchangeable weights ( 14 ), in which case the bar ( 12 ) extends (dotted lines on FIG. 3 b ) beyond an elbow ( 13 ) to engage one or more weights ( 14 ) or in the case of a fixed weight dumbbell with no interchangeable weights ( 14 ) the bar ( 12 ) is integral with the weights ( 14 ).
[0030] In order to make use of generic weights ( 14 ′), a swiveling bar assembly ( 20 ) is shown in FIG. 4 in which ends ( 17 ) of the bar ( 12 ) do not connect with proprietary weights ( 14 ) but rather non proprietary weights ( 14 ′) similar to those found in the prior art. In order to connect with the weights ( 14 ′), each end ( 17 ) of the bar ( 12 ) connects to a first member ( 22 ) and that first member is rotationally connected to a second member ( 24 ). The second member ( 24 ) has a rod ( 26 ) extending therefrom. The rod ( 26 ) is configured similar to a bar ( 12 ′) of the prior art (or the dotted lines of FIG. 3 b ) and as such, can receive weights ( 14 ′). The rotational connection between the first member ( 22 ) and the second member ( 24 ) can be by way of ball bearings although any suitable rotational connector as are known in the art could provide the required rotational means. The bar ( 12 ) thus being able to rotate, the weights ( 14 ′) do not require to have stabilizing elements ( 15 ) as described earlier but the bar ( 12 ) or the weights ( 14 ′) can still make use of the indicia ( 16 ) as described earlier.
[0031] An obvious variation would be to have a bar ( 12 ) with elbows ( 13 ) as shown partially in dotted lines in FIG. 3 but used with non proprietary weights ( 14 ′) which of course would have the dumbbell off kilter when laid on a flat surface but would still be usable for exercizing. Also, the means used for attaching removable weights ( 14 ′) are similar to means known in the art.
[0032] As to a further discussion of the manner of usage and operation of the present invention, the same should be apparent from the above description. Accordingly, no further discussion relating to the manner of usage and operation will be provided.
[0033] With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention.
[0034] Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.
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A dumbbell having a bar that is set non perpendicularly to the weights of the dumbbell and has added features such as indicias that a user can quickly see in order to know which direction the dumbbell is for appropriate grasping as well as footings which orient the dumbbell so as to make it easy to use. Since the bar reorients the weights so that they do not interfere with the body, a shorter bar can be used which brings each weight closer to the other.
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[0001] Priority of application Ser. No. 60/400,219 filed Jul. 31, 2002, in the United States Patent Office is hereby claimed.
BACKGROUND OF THE INVENTION
[0002] The present invention relates generally promoting the development of conservation areas through the granting of conservation easements on real property.
[0003] The conservation movement has been very successful in educating the public about the need to husband resources and protect lands from development for future enjoyment by the next generation such that the land is still in its natural or historic state. In some cases, wealthy philanthropists donate the land for a public good and the government manages the land through a trust typically set up by the philanthropist.
[0004] Some lands, however, are able to be utilized by the property owner, yet, the desire to restrict the future development of that property is also important so rather than grant the land over to the government or a non-profit entity in its entirety, federal and state governments have established what are called conservation easements that allow the landowner to retain ownership of the land, but provide the public with assurances that the land will not be developed against the restrictions of the easement.
[0005] A conservation easement is a set of restrictions a landowner voluntarily places on his or her property in order to preserve its conservation values. The conservation values of the property and the restrictions created to preserve those values, along with the rights reserved by the landowner, are detailed in a legal document known as a conservation easement. This document is filed with the local county land records. Conservation easements are utilized to allow interested landowners the opportunity to preserve important natural and scenic resources by limiting the use and development of their land.
[0006] A conservation easement is conveyed to a government agency or non-profit conservation organization qualified to hold and enforce easements. Most conservation easements are perpetual. They apply to the current owner and all future landowners, permanently protecting the property. Furthermore, each conservation easement is unique, specifically tailored to the particular land being protected as well as to the particular situation of the landowner.
[0007] Conservation easements are typically utilized to protect lands that serve as natural habitat for wildlife, fish and plants and include areas such as prairies, forests, bluff lands, or wetlands. They protect lands that have lakeshore, rivers and streams that are desired to be preserved. Further, they serve to protect scenic landscapes, particularly those with local community, cultural or historic significance.
[0008] When a conservation easement is crafted, the conservation values are first defined and then restrictions are created to protect those values. Restrictions may apply to all of a landowner's property or to only a portion of it. Typically, easements address subdivision, commercial or industrial uses, mining, construction of buildings or roads, utilities, disturbance of the vegetation or topography. These easements preclude activities on the property that might interfere with the conservation purpose for the easement. For example, an easement preserving rare woodland habitat may require that the property be left entirely in its natural state, prohibiting all development. Or, to protect a lake or stream, an easement may allow limited inland construction of buildings or trails while restricting such activities along the more fragile shoreline. Some easements may permit continued farming or limited timbering. Others may provide for enhancement of wildlife habitat or restoration of native prairie. Still others may provide for recreational activity such as hunting or fishing, or sports activities such as golf, hiking or cycling.
[0009] After a conservation easement has been placed on the landowner's property, the landowner still retains all rights to the property not specifically restricted or relinquished by the easement. The landowner still owns the land and has the right to use it for any purpose that is consistent with the easement, to sell, to transfer or to leave it through a will. Typically, landowners also retain the right to restrict public access.
[0010] Since the landowner continues to possess the land, the landowner remains responsible for the land such as for its maintenance and upkeep, for paying taxes and for otherwise meeting the typical obligations of landownership. Conservation easements add only a few further requirements. These typically include notifying the state land trust of any proposed changes to the property, allow for periodic monitoring visits of the property, notifying the state land trust when selling or transferring the property is to occur, and to comply with the restrictions in the easement.
[0011] Conservation easements are encouraged because they are a cost-effective tool to protect a state's increasingly threatened land and water resources, preserve wildlife habitat, safeguard the waters and capture scenic vistas for present and future enjoyment. Conservation easements provide landowners with a living legacy as they have protected the land so that it will be respected and remain essentially the same throughout time.
[0012] In order to encourage greater use, conservation easements have been structured to provide financial benefits for their creation. These benefits are intended to promote and reward those who relinquish their rights and encumber their lands with such easements. Firstly, a conservation easement can result in a tax deduction both on the federal income tax as well as the state tax, depending upon the conservation easement statutes in that particular state. The donation of the conservation easement may allow the owner to claim such a federal income tax deduction for the value of the easement.
[0013] The value of the easement is calculated under several possible methods. In one method, the easement is valued as the difference in value of the land as appraised before and after the easement has been placed on the land. Another method of valuing the easement is to appraise the land for its possible economic development value, less the cost necessary to provide such development, and then less the cost of the land with the easement placed thereon.
[0014] If the easement is granted via a will, the conservation easement may reduce the federal estate tax, which makes this an effective way to transfer land to the next generation with its natural features intact. Further, as the easement reduces the value of the land, it may also result in lowered annual property taxes.
[0015] Often, the value of the tax deduction for the easement exceeds the ability of the landowner to fully take advantage of the value of the tax benefit. At times, the inability of the landowner to make full use of the tax benefit tends to discourage the landowner from placing an easement on the land as the economics of doing such makes it difficult for the landowner to dedicate the land to the public through the restrictions established in the easement. Such limitations deter expansion of the conservation easement program and therefore frustrate the public policy of land preservation.
[0016] Accordingly, what is needed is a method of enhancing the incentive to the landowner to grant a conservation easement on the landowner's property as well as to maximize the monetary interests that the easement can generate so as to promote the granting of more easements than would otherwise be possible.
SUMMARY OF THE INVENTION
[0017] According to the present invention, a method of encouraging the formation of conservation easements on real property is disclosed. The method comprises identifying a parcel of real property owned by a first party and suitable for securing a conservation easement wherein the first party is unable to utilize a maximum monetary value generated by the conservation easement; selling an interest in the identified parcel of real property to an intermediate party qualified to receive maximum tax deduction benefit for the conservation easement; processing the conservation easement on the parcel of real property with proper government authorities; and exchanging at least a portion of the monetary value in the real property with the conservation easement to the intermediate party for consideration less than the maximum monetary value.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] [0018]FIG. 1 is a block diagram of the formation of a conservation easement with an attending investment group(s) that encourages such easements in accordance with an embodiment of the present invention.
[0019] [0019]FIG. 2 is a flow diagram of the encouragement of conservation easements involving the group(s) of FIG. 1.
[0020] [0020]FIG. 3 depicts a flow diagram of determining the monetary value of the easement.
[0021] [0021]FIG. 4 depicts a flow diagram of determining the monetary value of the easement based on a virtual business plan in accordance with the present invention.
DETAILED DESCRIPTION
[0022] Reference will now be made to the exemplary embodiments illustrated in the drawings, and specific language will be used herein to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended. Alterations and further modifications of the inventive features illustrated herein, and additional applications of the principles of the inventions as illustrated herein, which would occur to one skilled in the relevant art and having possession of this disclosure, are to be considered within the scope of the invention.
[0023] Conservation easements serve as an important tool for increasing the stock of lands that are protected from future development for the preservation of either their natural beauty or historic value to society. To promote the formation of conservation easements, various state and federal governments have introduced tax benefits through either tax deductions or actual tax credits to reward and promote the formation of such conservation easements. Often, however, the landowner is unable to utilize fully the tax deductions generated by the formation and recording of the conservation easement on the landowner's property. To this end, the present invention provides a way of allowing the full benefit of the tax deduction and tax credits generated by the placement of a conservation easement on a particular property to be shared by those not originally part of the landownership that initially proposed and pursued the conservation easement. The invention proposes to bring together those landowners whose easements generate more tax deductions and benefits than otherwise possible to be utilized by the landowner and share them or transfer them to other groups who may be able to take full advantage of the maximum tax benefits and monetary interest provided in such tax incentives. Typically, the landowner receives some additional consideration as compensation for yielding the tax benefits to the other interested parties. It is through this maximizing the monetary interests that are provided through the tax incentives granted by the various states and federal governments that an increase in the formation and recordation of conservative easements is encouraged and promoted.
[0024] The formation of the conservation easements and the promotion thereof can be enhanced by first identifying a parcel of real property owned by a landowner that is suitable for the granting of a conservation easement. Typically, this landowner is unable to utilize the maximum monetary value generated by the conservation easement through the tax deductions and credits associated with the easement's reduction of value of the real property. An undivided interest in this parcel of land is sold to one or more individuals or a group of individuals such as a limited liability corporation, before the easement is recorded. The landowner receives some compensation directly for allowing the easement to be placed on the property. The individual or groups of individuals purchasing the interest then are then entitled to share in the monetary interest generated by the tax consequences of the easement being placed on the land. This group may either enjoy the monetary interest solely or share the interest with yet a third party in exchange for some type of consideration so that the remaining and maximum value of the monetary interest generated by the tax consequences may be fully utilized.
[0025] In order for the monetary interests and value in the real property to be transferred to these other parties, strict procedures must be followed so that the conservation easement qualifies as a tax deductible easement under Internal Revenue Code § 170(h). One requirement is that the conservation easement is managed by a non-profit organization that qualifies as a charitable contribution organization under Internal Revenue Code § 501(c)(3). FIG. 1 illustrates a relational diagram involving groups of individuals or entities that participate in the maximization of the utilization of monetary value realized in the formation of and placement of a conservation easement on a parcel of real property. FIG. 2 depicts the steps taken to enhance the grant of conservation easements as carried out by the groups of FIG. 1. A parcel of land is identified by the owner 10 upon which the conservation easement will be placed (block 50 ).
[0026] Typically, the property owner 10 whose land is to be encumbered with the easement is an individual or C Corporation that is unable to take full advantage of the tax benefits that accrue to the property and the owners through the placement of the easement on the property. An intermediate party 12 who has access to investor groups that have an interest in obtaining the monetary tax value that would otherwise be unrealized in real property is introduced to the property owner 10 (block 52 ). The intermediate party 12 may be an individual or a group of investors. This intermediate party 12 encourages the property owner 10 to participate in the conservation easement program (block 54 ). A real estate transaction occurs between these two entities 10 and 12 (block 56 ) and allows the intermediate party 12 to share and take advantage of the monetary value of the tax consequences of the easement. After the undivided interest has been sold to the intermediate party 12 , the easement is recorded (block 58 ) in the land office 16 of the state of residence of the land. The easement is also granted to a qualified land trust 14 or state organization (block 60 ) to manage the easement so that it properly qualifies as a charitable deduction according to the specific state and federal regulations associated with the land.
[0027] If the intermediate party 12 has sufficient enough income that can be offset by the full value of the monetary interest of the tax consequences of the encumbering of the easement on the property, then the members or the individual in the intermediate party utilizes the full benefit of the tax consequences associated with the property (block 62 ). For example, if the landowner is merely an individual, often the value of the easement exceeds the adjusted gross income (AGI) deduction potential that the landowner could otherwise take individually. Although there are provisions for the deduction to be spread out over years, the value of the deduction is diluted by limiting the landowner to taking incremental deductions over the course of years. The value of the deduction is greatest when it is maximized in a given year, rather than spread out over multiple years. Consequently, the intermediate party 12 either has sufficient resources to be entitled to offsetting the value of the tax consequences against their own adjusted gross income or, the intermediate party 12 can act with a third party 18 (block 64 ), which typically is one or more investors that have sufficient enough AGI such that the full value of the tax consequences of the easement encumbrance on the real property can be fully realized by this third party 18 .
[0028] With the exchange of consideration with the second party 12 , the third party 18 receives the tax deductions in a pass-through mechanism allowed by the federal tax code. Typically, the consideration paid by the third party 18 is less than the full value of the tax deductions so that the third party 18 receives a benefit and has incentive to invest with the intermediate party 12 . It is through the shifting of consideration from one party to another in exchange for the use of the monetary value of the tax consequences of the easement that encourages or promotes the placement of the easements on real property than would otherwise be possible if the landowner was the sole entity that could utilize the tax deductions associated with the easement.
[0029] The value of the tax deductions, as shown in the flow diagram of FIG. 3 is based on taking the difference of the value or fair market value (FMV) of the land before the easement and then assessing the value of the land after the easement. Often, however, the land is undeveloped at this point and so the market value of the land prior to the easement is rather low and the value of the property after the easement is not much less than the original value. In order to maximize the opportunity for promoting easements, the value of the land prior to the easement may be calculated by determining what the actual high market value of the land would be were it to be developed in a realistic business endeavor. This is shown in the flow diagram of FIG. 4. Typically, developed land is worth far more than undeveloped land and this is including deducting the cost incurred to develop the land for the business use. As such, what may be done is to formulate a business plan of developing the land (block 70 ), back out the actual costs required to develop that land (block 72 ), and then utilize the fair market value of the developed land in a virtual sense (block 74 ) in order to maximize the tax consequences that may be beneficial to the landowner and the investment group participating in the sharing of those tax benefits.
[0030] Thus if a parcel of property is worth $100,000 prior to development, and is worth only $60,000 after an easement is placed thereon, then the actual tax deduction would be $40,000, of which 35% to 40% typically passes through at the highest level of federal and state tax write off. A single property owner may not have sufficient incentive to forfeit land rights for this amount.
[0031] If, however, the property that is valued at $100,000 prior to development is developed in a virtual sense, in other words plans are formulated and costs are incurred and a fair market value assessment of what the land would be worth after the development has been performed, the value can be substantially increased. In this example, the developed land may be worth $500,000 after construction, with construction costs amounting only to $200,000. Thus, the value of the land would then be $500,000 less $200,000 which yields $300,000. This value is then deducted from the actual market value of the land with the easement in place, which is $60,000. Thus, the tax write off would then be $300,000 minus $60,000, yielding $240,000. This is much greater than the $40,000 that the landowner would have been entitled to under a straight fair market adjustment from pre-easement to post-easement.
[0032] In the case of the higher developed value, the landowner may not be able to maximize this write off against their own adjusted gross income, resulting in an economic loss. Further, if the landowner is a C Corporation, then the landowner is entitled to take merely a 10% deduction rather than the 30% deduction that is entitled to non C Corporation type entities. The value of a 10% deduction on $240,000 is merely $24,000. The value of a 30% deduction on $240,000 is $72,000, a $48,000 increase. The intermediate party 12 can then pass this $74,000 tax deduction to the third party 14 in exchange for consideration, typically the third party 14 may pay anywhere from 50% to 80% of the tax deduction value in order to receive even half or 20% of the actual tax deduction value. This still nets the third party anywhere from $10,000 to $30,000 in real money that would otherwise be lost where the landowner was the only entity entitled to utilizing the tax deduction.
[0033] It is to be understood that the above-referenced arrangements are only illustrative of the application for the principles of the present invention. Numerous modifications and alternative arrangements can be devised without departing from the spirit and scope of the present invention while the present invention has been shown in the drawings and fully described above with particularity and detail in connection with what is presently deemed to be the most practical and preferred embodiments(s) of the invention, it will be apparent to those of ordinary skill in the art that numerous modifications can be made without departing from the principles and concepts of the invention as set forth in the examples.
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A method of encouraging the formation of conservation easements on real property is disclosed. The method comprises identifying a parcel of real property owned by a first party and suitable for securing a conservation easement wherein the first party is unable to utilize a maximum monetary value generated by the conservation easement; selling an interest in the identified parcel of real property to an intermediate party qualified to receive maximum tax deduction benefit for the conservation easement; processing the conservation easement on the parcel of real property with proper government authorities; and exchanging at least a portion of the monetary value in the real property with the conservation easement to the intermediate party for consideration less than the maximum monetary value.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This is a non-provisional application claiming the benefit of U.S. Provisional Patent Application Serial No. 60/460,487, filed on Apr. 3, 2003, and entitled Articulating Shaft, which is fully incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates generally to surgical instruments and more specifically to instruments having flexible or articulating shafts.
[0004] 2. Description of the Prior Art
[0005] Surgical instruments, particularly those used in arthroscopic surgery, commonly are constructed with a shaft having a proximal end and a distal end. Some of these instruments have flexible shafts which permit them to be bent into a desired configuration. In most of these cases, the proximal end of a shaft is operable to articulate the distal end of the shaft.
[0006] By way of example, it will be noted that in many arthroscopic surgeries it is necessary to introduce a forceps or some other instrument through a straight cannula. Once the tip of the instrument is inside the body it may be desirable to force a curve into the distal end so that the tip can cut, grab or perform some other function from a perspective not possible with a straight approach. Many instruments have a bend permanently set in the distal end; in order to accommodate such an instrument, a straight cannula with a very large diameter has been required.
BRIEF SUMMARY OF THE INVENTION
[0007] In accordance with at least one embodiment of the present invention, a flexible shaft is provided which can be controlled at the proximal end to flex or articulate the shaft at the distal end. It is of particular advantage that the shaft can be locked in the desired shape so that it maintains the shape while accommodating aggressive cutting or grabbing of the tissue. In one aspect of the invention, an articulating shaft has a distal end that is bendable by operation of a proximal end of the shaft. An outer member having an axis extending from the proximal end to the distal end is provided in the form of an outer tube. An inner tube is disposed within the outer tube. Portions of one of the inner tube and the outer tube define a slot having a first end and a second end wider then the first end. A wedge is carried by the other of the inner tube and the outer tube and is movable within the slot between the first end of the slot and the second end of the slot. The outer tube and the inner tube are operable at the proximal end to move the wedge within the slot toward the first end of the slot. This movement bends the tubes and articulates the distal end of the shaft.
[0008] In one aspect of the invention, an articulating shaft with a proximal end and a distal end is bendable at the distal end by operation of the proximal end. The shaft includes an outer member having an axis extending from the proximal end to the distal end, the outer member having a configuration of a tube with a first longitudinal side and a second longitudinal side Portions of the first longitudinal side define a slot having a first end and a second end wider than the first end. An inner member is disposed within the outer member and carries a wedge that is movable within the slot between the first end of the slot and the second end of the slot. The inner member is operable at the proximal end of the shaft to move the wedge within the slot and toward the first end of the slot. This movement bends the outer tube away from the first longitudinal side and toward the second longitudinal side of the outer member.
[0009] In another aspect of the invention, an outer tubular member has a longitudinal axis and portions defining a slot. An inner member is disposed within the outer member and movable about the axis of the outer member. A wedge is carried by the inner member and movable within the slot in an interference fit with the slot portions to bend the outer member.
[0010] In another aspect of the invention, the inner member is disposed within the outer member and movable with a turn of a particular distance and a particular direction to produce in the outer member a bend having a magnitude and direction. The magnitude of the bend is dependent on the particular distance of the turn, and the direction of the bend is dependent upon the particular direction of the turn.
[0011] In still a further aspect, the invention includes a method wherein an outer member is provided with a slot and an inner member is provided with a wedge. The inner member is mounted within the outer member with the wedge disposed in the slot. The outer member is bent in a first direction by turning the inner member in a second direction, while the outer member is bent in a third direction opposite to the first direction by turning the inner member in a fourth direction opposite to the second direction.
[0012] These and other features and advantages of the invention will become more apparent with a description of preferred embodiments and reference to the associated drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] [0013]FIG. 1 is a perspective view of one embodiment of the articulating shaft of the present invention;
[0014] [0014]FIG. 2 is a perspective view of an outer tube illustrating the narrow end of slots formed in one longitudinal side of the tube;
[0015] [0015]FIG. 3 is a perspective view of the outer tube showing a wide end of the slots formed in a second longitudinal side of the outer tube;
[0016] [0016]FIG. 4 is a side elevation view showing the individual slots with a narrow end and a wide end;
[0017] [0017]FIG. 5 is a top plan view illustrating a web disposed between the narrow ends of the opposed slots;
[0018] [0018]FIG. 6 is a perspective view illustrating an inner tube in the embodiment of FIG. 1;
[0019] [0019]FIG. 7 is a top plan view of the inner tube illustrating a web and bend stops associated with the slots;
[0020] [0020]FIG. 8 is a wedge pads associated with the embodiment of FIG. 1;
[0021] [0021]FIG. 9 is a perspective view of a wedge carried on a wedge pad of the inner tube;
[0022] [0022]FIG. 10 is a top plan view of the wedge;
[0023] [0023]FIG. 11 is a side elevation view of the wedge; and
[0024] [0024]FIG. 12 is a perspective view of a bent shaft.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] A flexible or articulating shaft is illustrated in FIG. 1 and designated by the reference numeral 10 . In this embodiment, the shaft 10 includes an outer tube 12 and a coaxial inner tube 14 that are circumferentially moveable with respect to each other. The tubes 12 and 14 are disposed on a common axis 16 , which extends between a proximal end 18 and a distal end 21 .
[0026] The outer tube 12 of this embodiment is illustrated in the perspective view of FIG. 2. In this view, it can be seen in the outer tube 12 has a pair of longitudinal sides 23 and 25 that are separated by a pair of webs 27 and 30 . A plurality of slots 32 are formed in the longitudinal side 25 and configured to extend circumferentially from a large end 34 to a narrow end 36 . Similar slots 38 are formed in the longitudinal side 23 . These slots 38 are formed as a mirror image of the slots 32 so that the narrow ends of the slots 32 and 38 are disposed in proximity to the web 27 , and the wide areas 34 of the slots 32 and 38 are formed in proximity to the web 30 . The outer tube 12 is rotated 180 degrees in the perspective view of FIG. 3 in order to better illustrate the wide end 34 of the slots 32 and 38 and the associated web 30 . A side elevation view showing the full length of the slots 32 is illustrated in FIG. 4, while the web 27 is best shown in the top plan view of FIG. 5.
[0027] A preferred embodiment of the inner tube 14 is illustrated in the prospective view of FIG. 6. This inner tube 14 also has slots 40 and 42 which are disposed on opposing sides of webs 44 and 46 . In the illustrated embodiment, the slots 40 and 42 are similar in shape and have a generally constant width along their circumferential length.
[0028] The slots 40 are defined by adjacent wedge pads 48 which extend circumferentially between the webs 44 and 46 . Similar wedge pads 51 define the opposing slots 42 which extend circumferentially between the webs 44 and 46 . A top plan view illustrated in FIG. 7 best shows the web 44 disposed between the slots 40 and 42 . From this view it can be appreciated that when the inner tube 14 is bent or articulated to the right in FIG. 7, the slots 40 close and form bend stops which inhibit overbending of the inner tube 14 . Similarly, if the inner tube 14 is bent to the left in FIG. 7, the slots 42 function as bend slots inhibiting overbending of the tube 14 .
[0029] A plurality of wedge pads 48 , best illustrated in the side view of FIG. 8, provide substrates for the attachment of wedges 60 , best illustrated in FIG. 9. In this embodiment, the wedge pads 48 are each provided with a cylindrical surface 53 that is bounded by radial surfaces 55 and 57 . It is these cylindrical surfaces 53 of the wedge pads 48 which are configured to receive the wedges 60 . These wedges 60 can be adhered, welded, machined or otherwise disposed in a fixed relationship with an associated one of the cylindrical surfaces 53 . In a preferred embodiment, the wedge 60 has a broad end 62 and a narrow end 64 with side surfaces 66 and 68 which extend between a concave surface 71 and a convex surface 73 . These elements are also illustrated in the top plan view of FIG. 10. Of course, the wedges 60 , 62 may have other than a triangular configuration; for example, a round pin may be of particular advantage in a different embodiment.
[0030] With further reference to FIG. 1, it can be seen that when operatively disposed, the wedges 60 are mounted with the concave surface 71 fixed to the cylindrical surface 53 of the wedge pad 48 . Importantly, the wedges 60 are mounted within respected slots 32 , with the broad end 62 of the wedge 60 facing the wide end 34 of the slot 32 and the narrow end 64 of the wedge 60 facing the narrow end 36 of the slot 32 . Other wedges 62 are similarly disposed on the opposite side of the shaft 10 and oriented as a mirror image of the wedges 60 in the slots 42 .
[0031] In operation, the inner tube 14 can be rotated relative to the outer tube 12 to move the wedges 60 and 62 within their respective slots 32 and 42 . When the inner tube is turned counterclockwise with respect to the outer tube 14 , the wedges 60 move toward the narrow end 36 of the slots 32 , upwardly in FIG. 1. As this movement occurs, the wedges 60 tend to separate the walls defining the slots 32 . As a result, the side of the tube 12 which has the slots 32 and the wedges 60 , tends to elongate. This same counterclockwise rotation moves the wedges 62 downwardly toward the broad end of the slots 42 . This permits the side of the tube 12 having the slots 42 and wedges 62 to contract. This opposing expansion and contraction articulates the outer tube 12 as well as the inner tube 14 so that the entire shaft 10 tends to bend away from the slots 32 and towards the slots 38 . It will be noted that the direction the inner tube 14 is turned is an angular direction, while the direction the outer tube 12 is bent is a linear direction.
[0032] The opposite effect is achieved when the inner tube 14 is rotated clockwise with respect to the outer tube 12 . In this case, the wedges 62 move toward the narrow end of their slots 42 causing those slots to expand and the associated side of the tube 12 to elongate. The wedges 60 are moved toward the wider end of their slots 32 to permit contraction of their side of the tube 12 . As a result, the shaft 10 tends to articulate away from the slots 38 and towards the slots 32 . This articulation of the distal end 21 of the shaft 10 is accomplished merely by rotating the tubes 12 and 14 relative to each other at the proximal end 18 to the shaft 10 .
[0033] In will be appreciated that in another embodiment of the invention, the tubes 12 and 14 could be switched. In such an embodiment, the wedges 60 and 62 would be carried on an inner surface of the outer tube and would be moveable within radial slots created in the inner tube.
[0034] In another embodiment, the wedges 60 and 62 , could be replaced generally with any structure moveable within radial slots to alternatively expand and contract these slots on opposing sides of the shaft. As an example and not by way of limitation, the wedges 60 and 62 may be replaced with round pins, for instance.
[0035] One advantage associated with the present invention relates to the tendency of the wedges 60 and 62 to remain at any given point within the associated slots 32 , 34 until the tubes 12 and 14 are again actively rotated relative to each other. This locking feature of the associated embodiment, is achieved by the frictional resistance encountered between the wedges 60 , 62 and the associated sides of their respective slots 32 and 38 . The locking feature can be further enhanced by adding frictional resistance in the form of detents located on the proximal control sections. In general, the locking feature permits the surgeon to articulate the shaft to a particular curve configuration and to know that the shaft 10 will retain that degree of curvature until it is changed by the surgeon.
[0036] These features collectively permit the surgeon to introduce the shaft 10 through a small diameter straight cannula and then to operate the shaft 10 at the proximal end 18 to articulate the distal end 21 . When the desired degree of articulation is achieved, the relative rotation of the tubes 12 and 14 can be stopped and the locking feature relied on to maintain the desired bend through aggressive cutting and/or grabbing of the tissue.
[0037] Thus, these and other modifications and additions will be obvious to those skilled in the art and may be implemented to adapt the present invention for use in a variety of different applications.
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An articulating shaft includes an outer tubular member having a longitudinal axis and portions defining a slot. An inner tubular member is disposed within the outer member and movable about the axis of the outer member. A wedge carried by the inner member is movable within the slot in an interference fit with the slot portions to articulate the outer member. In an associated method, the inner member can be turned in a first direction to bend the outer member in an associated second direction, and the inner member can be turned in a third direction to move the outer member in an associated fourth direction.
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BACKGROUND
In a traditional method of building masonry walls, a mortar mix has been commonly used to hold blocks together horizontally as well as vertically. The mix of sand and cement resists compression but does not resist lateral impact.
BRIEF SUMMARY OF THE INVENTION
With the proposed method, which is based on the modular dimensioning of the blocks, a continuity of vertical holes in the blocks is achieved for both sand with cement, as well as clay. A specially designed device (called “connector”) is proposed for assembling one block with another and achieve such continuity of the holes in the blocks, in such a manner that the building of masonry walls is done in a dry mode, that is with no mortar mix needed for holding the blocks together, providing the following advantages:
Savings in manpower, as skilled labor is not needed except for a bricklayer to install the first row. Savings in materials, with less waste since a mortar mix is not used between blocks. Time savings in the building of walls, which can be assembled much more rapidly, by positioning the blocks with no need for leveling and no use of mortar mix. Time savings in the finishing of walls with mortar which is applied to the vertical surfaces of the blocks only to seal the blocks. Savings in that plastic materials which are non-biodegradable are recycled to make the connectors used to hold the blocks together, thus lessening the impact on the environment. Savings in the amount of mortar mix (sand and cement), reducing the indiscriminate extraction of sand from the littoral or beaches.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an embodiment of a clay block according to the invention.
FIGS. 2A , 2 B and 2 C are plane and elevation views of an embodiment of a clay block according to the invention with a slot for anchoring to a steel structure.
FIGS. 3A , 3 B and 3 C show respectively a perspective view, plane view and side elevation view of an embodiment of the connector 1 A according to the invention.
FIGS. 4A , 4 B and 4 C show respectively a perspective view, plane view and side elevation view of an embodiment of the connector 2 A according to the invention.
FIG. 5 shows a plane view of an embodiment of a concrete block according to the invention.
FIGS. 6A , 6 B and 6 C show respectively a perspective view, plane view and side elevation view of an embodiment of the connector C 1 according to the invention.
FIG. 7 shows a plane view of an embodiment of a thicker block and connectors according to the invention.
FIGS. 8A , 8 B and 8 C show respectively a plane view, elevation view and lateral view of an embodiment of a connector C 2 according to the invention.
FIGS. 9A , 9 B and 9 C are schematic side view illustration of the fastening of the blocks in the top row by means of an extensor according to the invention.
FIGS. 10A , 10 B and 10 C are schematic plane views of mortar-filled reinforcing columns at the corner and adjacent to the corner in T-shaped, +-shaped and L-shaped intersections of walls.
FIGS. 11A , 11 B and 11 C are respectively perspective views of L-shaped, T-shaped and +-shaped intersecting walls reinforced at the corner with concrete filling around a steel bar.
FIGS. 11D and 11E are respectively perspective views of holes reinforced with concrete filling around a steel bar adjacent to a window opening or at the edge of a free-standing wall.
FIGS. 12A , 12 B and 12 C show respectively a front view, a plane view and another front view of an inclined wall reinforced with a mortar filled column and a reinforcing abutment.
FIG. 13 is a plane view showing the required dimensions for a whole block according to the invention.
FIG. 14 shows schematically an embodiment of a wall built with the blocks and connectors according to the invention.
DESCRIPTION OF THE INVENTION
The construction system of the invention consists of an original method in which the holes in the blocks are aligned exactly in a vertical direction. That is achieved by a special modular configuration for the blocks which can be of clay or concrete, both conventional primary materials. For joining the blocks we use a device that we call “connectors” to hold the blocks internally, providing great strength and sturdiness to the masonry, eliminating the use of mortar mix (cement and sand) between the blocks in the vertical as well as horizontal directions.
The construction system of the invention is characterized by the following:
a. VERTICALITY. Due to the fact that the system consists of assembling the blocks by means of the internal connectors, the verticality of the wall is maintained (plumb and square.) Therefore the construction of the walls is completed without having to use fillers to ensure verticality, resulting in a direct saving in masonry. b. PATTERN DEVELOPMENT. Blocks were developed with special patterns which are produced industrially by means of specific machinery, nozzles and dies designed by the inventor. c. EFFICIENCY. Consists of rationalizing construction, reducing costs, shortening delivery dates and eliminating waste. d. DRY CONSTRUCTION TECHNIQUE. Assembly done by an internal fitting system, very simple, low cost and efficient e. CONNECTORS. The connector piece is made of recycled plastic material of high strength, which holds the blocks together internally. f. APPEARANCE. Has an appearance similar to that of conventional masonry. The characteristic of this system of blocks and connectors is that they are the only unique and differentiated elements of the process, as the remaining components and their application are similar to conventional ones, except that their use is rationalized in terms of patterns and sizes.
The construction system of the invention presents the following advantages:
The construction system of the invention presents the following advantages:
Speed (50% faster)
Due to the fact that the construction is carried out in a toy building block-like manner, the walls are built quickly without having to wait for the mortar to set so that the external finish of the walls can be performed right after the assembly of the blocks.
Lower cost (30% cheaper) per meter
Since no mortar mix is used between blocks, the need for skilled labor is reduced (one assistant and one masonry apprentice) for the assembly. Furthermore are savings in materials for the mortar mix and its respective waste.
Elimination of the use of skilled labor in the erection of walls. Conventional masonry techniques are used only for the first row. Only one qualified bricklayer is needed for the leveling and laying of the first row. Computerized design of the work, flexibility in the modular design (three sizes of blocks). The design can dimension the walls with this system with elimination of waster, by using the three sizes of blocks, avoiding the need to split a block and discard the remainder. Ease of expansion, addition and repair in civil construction sites. Can be performed very fast; construction of a wall can be extended in other directions by using the connectors, providing easy expansion without difficulty, reducing waste on the site while providing a solid and safe wall.
Clean worksite without debris Except for the blocks and connectors, the rest of the components of the construction are conventional and available commercially.
A. Ceramic Blocks:
A strict and exact modular sizing has been established for the ceramic (clay) blocks.
To streamline the construction three types of blocks are used, all of the same height, as shown in the following chart for clay blocks. An embodiment of such a block as shown in FIG. 1 has three holes ( 2 ). FIGS. 2A , 2 B and 2 C show an embodiment of a block provided with a slot ( 4 ) for anchoring the block to a steel structure ( 6 ) with a steel bracket ( 5 ).
TABLE FOR CLAY BLOCKS DIMENSIONS TYPE E H L AREA VOLUME WEIGHT SERIES BLOCK THICKNESS HEIGHT LENGTH (M 2 ) (M 3 ) (KG) A A1 10 30.5 10 0.030 0.0013 1.560 A2 20 0.060 0.0026 3.120 A3 30 0.090 0.0044 5.280 B B1 12.5 30.5 12.5 0.038 0.0018 2.160 B2 25 0.075 0.0035 4.200 B3 37.5 0.113 0.0051 6.120 C C1 15 30.5 15 0.045 0.0023 2.760 C2 30 0.090 0.0044 5.280 C3 45 0.135 0.0064 7.680
Connectors
As the construction is a dry construction system, a connector has been designed for the fitting of one block with another. Two connectors are used per block. For each type of block a respective type of connector was created.
There are two types of connector for clay blocks: connector 1 A and connector 2 A.
CONNECTOR 1 A is shown in FIGS. 3A , 3 B and 3 C.
CONNECTOR 2 A is shown in FIGS. 4A , 4 B and 4 C.
(For filling with concrete the holes in the block.) The connectors are made of recycled plastic material having high strength.
The CONNECTOR 1 A is used to fit one block with another. The CONNECTOR 2 A is used when there is a need for more resistance and stability.
B. Concrete Blocks:
Just as with the ceramic blocks, the modular configuration is maintained in order to achieve continuity of the vertical holes. Rationalization is derived from the use of ⅓ blocks; ⅔ blocks and whole blocks. To streamline and reduce construction costs. See table below.
TABLE FOR CONCRETE BLOCKS
DIMENSIONS
TYPE
E
H
L
AREA
VOLUME
WEIGHT
SERIES
BLOCK
THICKNESS
HEIGHT
LENGTH
(M 2 )
(M 3 )
(KG)
A
A1
10
21.5
10
0.0215
0.00138
3.036
A2
20
0.0430
0.00281
6.182
A3
30
0.0645
0.00413
9.086
B
B1
12.5
21.5
12.5
0.0215
0.00269
3.982
B2
25
0.0430
0.00538
8.118
B3
37.5
0.0645
0.00806
11.058
C
C1
15
21.5
15
0.0215
0.00323
4.928
C2
30
0.0430
0.00645
9.878
C3
45
0.0645
0.00968
14.044
The connectors are of the same size and shape as the holes in the blocks. The connector is at one end of the same size as the upper portion of the hole, and at the other end has the dimension of the lower portion of the hole, the holes in the block being slightly conical. In the middle of the connector is a horizontal plate which separates the two connected blocks in a uniform manner.
Depending on the building needs the following are provided:
B.1. 10 cm×45 cm Blocks
10 cm blocks. Having conventionally a length of 45 cm. With three oval shaped holes. Said holes are of trapezoidal shape to facilitate unmolding during the manufacture of the blocks.
Connectors C 1 .
The connectors for the 10 cm concrete blocks have two dimensions because of the configuration of the holes in the block, since those holes are slightly trapezoidal.
B.2. 15 cm×45 cm Blocks
To meet the needs in different stages of the construction, a block of large thickness, as shown in FIG. 7 , has been designed as required for thicker walls, e.g. bathrooms.
Connectors C 2 :
The connectors for 15 cm concrete blocks were designed in a manner that they can be used in both directions in the holes of the blocks, to provide better stability to the wall and maintain the fitting in two dimensions due to the configuration of the hole of the block, the holes being slightly trapezoidal. These connectors are illustrated in FIGS. 8A , 8 B and 8 C.
With the construction system of the invention, the process starts after having the floor or slab for the construction. To proceed, follow the sequence of steps described below:
1. The first row is placed on mortar or a traditional mix and checked to be plumb and square, the subsequent blocks are positioned by means of the connectors, using two connectors per block, preferably in the outermost holes. 2. Doors and windows are dimensioned in a modular format. For example, the opening for a door should end in row number 7 or a multiple of 30 cm. Proceed with the same format for windows. 3. When reaching the final row, a piece called “EXTENSOR” is used to fix the wall to the tie beam or existing slab. See FIGS. 9A , 9 B and 9 C showing an extensor ( 7 ) between a block at the top of the wall and the lower face ( 13 ) of a slab or beam. A NEOPRENE rubber plate ( 8 ) is pressed against the lower face ( 13 ) by a screw ( 9 ) provided with a nut ( 10 ) and a washer ( 11 ). A flat bar of galvanized steel ( 12 ) is placed between the block at the top of the wall and the screw/nut/washer assembly. 4. Tie columns: To increase resistance and stability small columns are created by filling the holes in the block with 1:3:3 concrete and ⅜″ steel Embodiments of such columns formed by inserting a steel bar ( 14 ) in a hole and filling the hole with concrete ( 15 ) are shown in FIGS. 10A , 10 B, and 10 C, and FIGS. 11A , 11 B and 11 C.
a. Applied in cases such as: wall intersections in shape of L, T and +. The corners and the first hole in each direction are filled. b. The holes adjacent to windows and doors openings are filled in the same manner. c. In free standing walls, i.e., which do not intersect, the last hole is filled in the same manner. d. When the walls have long stretches, more than 2 meters, the holes are reinforced at every meter. e. An inclined wall as seen in FIGS. 12A , 12 B and 12 C may have a column filled with concrete ( 15 ) as well as an abutment ( 16 ) filled with concrete.
In preferred embodiments of the system of the invention, the blocks are characterized by the dimensions represented by the distance ( 2 A) at the center being twice the distance (A) at the end of a block, i.e., equal parts from center to center of each section of the block. This exact and repetitive modular configuration ensures continuity of the holes in a vertical succession of holes from one layer to another. An example of these dimensions is shown in FIG. 13 , which illustrates that the distance X should be the same in all the sections of the blocks. This principle also applies to blocks with different sizes and numbers of cells or holes, and for holes with different shapes but of equal dimensions. By following this modular configuration the holes or cells are held in vertical continuity, as illustrated in FIG. 14 .
As we have described the invention consists of two basic and indispensable elements for fulfilling the purpose of the invention, one being the blocks to be correctly set in modular fashion, and the other being the connectors which are fitted in the holes of the blocks. One advantageous aspect of the system of the invention is that no mortar is needed for fixing one block to another, either in the vertical or horizontal direction. Another novel aspect is that, since the assembly is a dry technique, it is not necessary to wait for the setting or hardening of the mortar so that the wall can be completed by proceeding immediately to the step of applying an outer finishing layer to the wall.
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The invention relates to the Soloarmar construction system comprising an original wall construction method, in which the cavities in the blocks are precisely aligned in the vertical axis. According to the invention, the blocks are assembled using an inner engagement device such that resistant masonry can be produced quickly and specially adapted for clay or concrete blocks using specific industrial templates, machines, nozzles and dies designed by Soloarmar. The appearance and characteristics obtained are similar to those obtained with standard masonry techniques, but with the mixture only being used to lay the first course instead of between all of the blocks.
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BACKGROUND OF THE INVENTION
The present invention relates to methods for detection of anti-human leukocyte antigen (HLA) reactive antibodies. Individuals may be sensitized to HLA antigens during pregnancy, or by blood transfusion or previous organ grafts. Testing to determine sensitivity to HLA alleles is relevant to tissue and organ transplantation where the presence in the recipient of antibodies against HLA antigens of the donor (donor specific crossmatch) is predictive of a high risk of graft rejection. It is a standard practice in the transplant field to test all potential recipients against a panel of HLA antigens selected to represent a human population and the percentage of HLA alleles against which the serum is reactive is determined. In this panel reactive antibody (PRA) testing reaction of a patient's serum against a high percentage of HLA alleles present in a normal human population is predictive of a high risk of graft rejection.
Methods known in the art for HLA testing include the complement-dependent lymphocytotoxicity (CDC) test in which serum from a recipient is incubated with donor or panel lymphocytes followed by incubation with complement. The level of cytotoxicity is then estimated by discriminating between dead and viable cells using a dye. This method is labor intensive, requires viable cells, may be nonspecific and requires a subjective evaluation.
Pouletty et al. U.S. Pat. No. 5,223,397 discloses methods for testing HLA compatibility between a donor and a recipient comprising the steps of adding blood from the donor to a substrate having anti-HLA antibodies bound thereto and incubating for sufficient time for soluble HLA antigens present in the blood to bind to the antibodies or ligand. Blood from the recipient is then added to the solid substrate whereby any antibody specific for any HLA antigens bound to the solid substrate may become bound. The detection of an absence of antibodies from the recipient's blood to the HLA antigen is indicative of a cross-match.
Zaer et al., Transplantation 63: 48-51 (1997) discloses use of an ELISA using HLA class I molecules purified from pooled platelets to detect anti-HLA antibodies. The reference reports that in patients found to be unsensitized, the incidence of false-positive results was less for ELISA testing than for panel studies. In patients who were highly sensitized, both tests performed equally well, whereas discordant results were registered mainly in cases of mild sensitization. In such cases, the incidence of false-negative results was higher for ELISA testing than for panel studies.
Of interest to the present invention are assay methods making use of flow cytometry. Wilson et al., J. Immunol. Methods 107: 231-237 (1988) disclose the use of polyacrylamide microspheres coupled with cell membrane proteins in immunofluorescence assays for antibodies to membrane-associated antigens. The method is said to make possible the rapid flow cytometric analysis of plasma membrane antigens from cell populations that would otherwise be unsuitable for use in flow cytometry. Scillian et al., Blood 73: 2041-2048 (1989) disclose the use of immunoreactive beads in flow cytometric assays for detection of antibodies to HIV. Frengen et al., Clin. Chem. 40/3: 420-425 (1994) disclose the use of flow cytometry for particle-based immunoassays of α-fetoprotein (AFP). This reference further reports the ability of serum factors to cross-link labeled mouse monoclonal antibodies of irrelevant specificity to different particle types coated with various immunoglobulins.
Flow cytometry methods using lymphocytes are also known but suffer with difficulties because of the activity of auto-antibodies. See Shroyer et al., Transplantation 59:626-630. Moreover, when using flow cytometry with lymphocytes, use of ten or more different lymphocytes tends to result in confusing signals. As a consequence, studies using lymphocytes have been limited by presenting a small panel of HLA antigens that do not effectively simulate the distribution of HLA antigens in a normal human population.
Sumitran-Karuppan et al., Transplantation 61: 1539-1545 (1996) discloses the use of magnetic beads which use an anti-HLA capture antibody to immobilize a variety of soluble HLA antigens pooled from 80 to 100 individuals on each bead. The beads can then be directly added to patient serum for efficient absorption of HLA antibodies. The reference discloses visualization of antibody binding to the antigen-coated beads using flow cytometry. The reference suggests that this development will allow testing for antibody specificity for crossmatching purposes and for the screening of panel-reactive antibodies. The methods of Sumitran-Karuppan are limited, however, because the pooling of antigens causes sensitivity to certain rare HLA antigens. Moreover, the method is not capable of detecting the percentage of PRA.
Accordingly, there remains a need in the art for improved methods of HLA typing including methods for determination of percentage of PRA which is rapid, convenient and accurate.
SUMMARY OF THE INVENTION
The present invention generally relates to methods for detection of panel reactive antibodies in serum of a subject against HLA antigens including Class I and class II antigens. Specifically, the method comprises the steps of providing a collection of microbeads of different subtypes wherein microbeads of at least one subtype each present HLA antigens derived from a cell population presenting the same HLA antigens which is preferably but not necessarily a single lymphocyte cell line; adding serum from a subject to said collection of microbeads; incubating said serum and microbeads for sufficient time for anti-HLA antibodies in said serum to bind to said HLA antigens; removing said serum components which do not specifically bind with said HLA antigens presented on said microbeads; incubating said microbeads with a labeled ligand capable of binding with anti-HLA antibodies bound to said HLA antigens; removing said labeled ligand which is not bound to said anti-HLA antibodies; and detecting the presence of labeled ligand bound to said anti-HLA antibodies by flow cytometry. According to a preferred aspect of the invention, microbeads of each subtype present HLA antigens derived from a cell population presenting the same HLA antigens which can be derived from a single human individual and may be lymphocytes, platelets or another cell population which present HLA antigens. A preferred source is a single lymphocyte cell line. According to preferred methods of the invention, the panel of HLA antigens is selected to simulate distribution of Class I and/or Class II HLA antigens in a normal human population and also allows most rare antigens to be represented. According to particularly preferred methods, the panel comprises 54 different Class I HLA antigens obtained from 30 different cell lines. Alternatively, the panel can preferably comprise 22 different Class II HLA antigens preferably selected from 15 to 30 different cell lines. While the use of greater numbers of cell lines as sources for antigens can more closely simulate the natural distribution of antigens there is also a desire to minimize the number of cell lines used to promote greater sensitivity of the assay. Nevertheless, it will be within skill in the art to balance these factors in specifically designing an assay format.
The microbeads of the invention may be made of a wide variety of suitable materials with latex beads such as those available from Spherotech Inc. being particularly preferred. The microbeads may be of any size suitable for analysis by flow cytometry with diameters ranging from about 2 μm to about 15 μm being preferred and particles with diameters of about 3 μm being particularly preferred for beads presenting Class I HLA antigens and diameters of about 5 μm being preferred form beads presenting Class II HLA antigens. The invention further provides methods wherein microbeads of at least one HLA subtype differ from microbeads of at least one other HLA subtype by being selected to have different diameters or by having different labels such as are known to the art with fluorescent labels being preferred.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 depicts the correlation between the results of the method of the invention in determining the percentage PRA versus a standard cytotoxity test for sample sera; and
FIGS. 2a-2d depict the reaction of the mixture of Class I and Class II beads and their reaction to anti-HLA Class I antibodies (FIGS. 2a and 2b) or anti-HLA Class II antibodies (FIGS. 2c and 2d).
DETAILED DESCRIPTION OF THE INVENTION
The methods of the invention utilize microparticles coated with purified HLA antigen for detecting anti-HLA antibodies in human serum by flow cytometry. According to the methods of the invention, a panel of mixed microbeads coated with a panel of purified HLA antigens is used to detect percentage of PRA. The invention also provides an array of microbeads coated with different purified HLA antigens which are detectably distinguishable such as by being of different sizes or having distinguishable labels. Such a use of differently sized microbeads or microbeads labelled such as with fluorophores allows the identification and/or separation of different beads by flow cytometry.
According to a general method of practicing the invention, HLA antigen coated microbeads are incubated with serum to be tested for 30 minutes at 20°-25° C. at a suitable dilution which may readily be determined by those of skill in the art but preferably ranges from neat to a dilution of 1:10. The microbeads are then washed with wash buffer comprising PBS with 0.1% polysorbate 20 (TWEEN® 20 ) three times and are incubated with Goat anti-Human IgG antibodies conjugated with PE Phycocrythrin or FITC (fluorescine isothiocyanate) fluorescent labels and incubated for 30 minutes. The microbeads are then washed two times with wash buffer and analyzed on a flow cytometer. Sera which contains anti-HLA antibodies will show a fluorescent channel shift compared to negative sera. Signal thresholds can be established by testing both positive and negative control samples. Using such a cut-off, anti-HLA positive serum will be assigned by a higher fluorescent channel shift than the threshold while negative anti-HLA sera will be assigned by a lower fluorescent channel shift than the threshold. The reactivity of all of the bound antigens may be confirmed by the serological defined human alloantisera.
According to one aspect of the invention, a mixture of microbeads coated with a panel of purified HLA antigen selected to simulate the frequency of those antigens in a normal population may be used to determine the percentage of PRA. The percentage of PRA is represented by the percentage of the microbeads which are positive.
Other aspects and advantages of the present invention will be understood upon consideration of the following illustrative examples.
EXAMPLE 1
According to this example, Class I HLA antigen preparations were purified from Epstein Barr virus transformed lymphocyte cell lines according to the methods of Henderson et al., Virology 76: 152-163 (1977). Thirty of the Class I HLA antigen preparations were then selected to simulate the distribution of HLA in a normal population as set out in Table 1 and were coated by passive absorption onto 3 μm latex beads obtained from Spherotech according to the method of Cantarero et al., Anal. Biochem., 105: 373-382 (1980).
TABLE 1______________________________________Bead No. HLA CLASS I Antigen Typing______________________________________1 A11 B27, 482 M2, 29 B39, 563 A1, 29 B8, 454 A2, 24 B7, 555 A2, 25 B18, 646 A26, 24 B52, 627 A31, 68 B538 A2, 11 B13, 629 A23, 33 B45, 6310 A23, 34 B4411 A11, 23 B49, 5212 A11, 24 B59, 6013 A24, 33 B44, 5114 A23, 26 B41, 7215 A3, 32 B50, 5616 A2, 24 B54, 6717 A2 B52, 7318 A26, 66 B38, 7519 A11, 33 B51, 5420 A30 B13, 7221 A30, 36 B35, 7122 A69 B35, 6123 A1, 32 B60, 6424 A2 B7, 4625 A30 B4226 A2 B8, 5827 A2, 3 B58, 6528 A1, 36 B37, 5729 A3, 68 B7, 6530 A33, 36 B53, 61______________________________________
The reactivity of the HLA antigen on each bead was confirmed by a panel of serologically defined HLA inonoclonal antibodies or by human allosera using a flow cytometry test. Each bead reacted specifically to the HLA monoclonal antibodies or allosera with the same HLA specificity.
The sensitivity of the beads was tested by mixing two beads with different typing at different percentages. A minimum of 2 to 3% of one kind of bead was found to be sufficient to detect the antigen.
EXAMPLE 2
According to this example, the sensitivity of the microbeads useful with the invention was tested by carrying out a serial dilution of selected PRA sera. The results presented in Table 2 below show that most PRA sera decrease the percentage of reactivity at a 1:10 dilution measured by a cytotoxicity test while they did not decrease the percentage of reactivity at a 1:40 dilution by use of the microbeads in a flow cytometry device according to the invention.
TABLE 2______________________________________ Percentage FlowSera ID Dilution Cytotoxicity Cytometry______________________________________N21 1 40 1:10 10 41 1:20 0 30 1:40 0 41 1:50 0 18 1:160 0 16A2 1 30 1:20 0 25 1:40 0 26 1:80 0 8S193 1 25 1:10 31 28 1:20 17 100 1:40 10 100 1:80 0 100S176 1 54 1:10 24 40 1:20 28 41 1:40 10 40 1:50 0 40S199 1 100 1:10 10 97 1:20 3 97 1:40 10 97 1:50 3 99B73 1 65 1:10 27 54 1:20 3 40 1:40 3 43 1:50 0 25______________________________________
EXAMPLE 3
According to this example, an assay to detect panel reactive antibodies was carried out by mixing 10 μl of a mixture of the 30 different types of beads produced according to Example 1 with 100 μl (1:10 diluted) serum to be tested and incubating for 30 minutes at 20°-25° C. with gentle rotating. The beads were then washed three times with 1 mL of wash buffer. The beads were then incubated with 100 μl of 1:100 diluted Goat anti-human IgG-PE obtained from Jackson InnumoResearch for 30 minutes. The beads were then washed twice and 1 mL of wash buffer and read on a flow cytometer (B. D. FacStar Plus). The percentage of PRA is represented by the percentage of microbeads which are positively labelled.
According to this example, 61 sera samples including 22 negative and 39 PRA patients who had panel reactive antibody activities developed by earlier transplantation or transfusion were tested with the results shown in FIG. 1 which shows the correlation of the flow cytometry results with those where the same samples were tested by complement-dependent lymphocytotoxicity. The correlation coefficient R is 0.94 for the 61 data points indicating a high degree of correlation between results obtained by flow cytometry and those obtained by a cytotoxicity test.
EXAMPLE 4
According to this example, 30 Class II HLA antigen preparations as set out in Table 3 were purified from Epstein Barr virus transformed lymphocyte cell lines according to the methods of Henderson et al., Virology 76: 152-163 (1977). The antigen preparations may then be coated by passive absorption onto 5 μm latex beads obtained from Spherotech according to the method of Cantarero et al., Anal. Biochem., 105: 373-382 (1980). From this collection of Class II HLA preparations, from 15 to 30 beads may selected to simulate the distribution of the 22 Class II HLA antigens in a normal population.
TABLE 3______________________________________Beads No. HLA Class II Antigen Typing______________________________________1 DR15, 9 53, 51 DQ5, 92 DR4, 15 53, 51 DQ6, 73 DR16, 4 53, 51 DQ4, 54 DR8, 14 52 DQ4, 55 DR4, 7 53 DQ2, 86 DR15, 18 51, 52 DQ6, 47 DR11, 12 52 DQ5, 78 DR103, 17 52 DQ5, 29 DR1, 13 52 DQ5, 610 DR9, 10 53 DQ5, 911 DR15, 12 51, 52 DQ5, 712 DR16, 14 51, 52 DQ513 DR13, 8 52 DQ5, 614 DR11, 13 52 DQ5, 615 DR17, 7 52, 53 DQ2, 916 DR15, 8 51 DQ6, 817 DR15, 4 51, 53 DQ2, 618 DR15, 17 51, 52 DQ6, 219 DR15, 7 51, 53 DQ6, 220 DR1, 7 53 DQ2, 521 DR15, 11 52 DQ5, 622 DR7, 13 52, 53 DQ6, 923 DR15, 13 51, 52 DQ6, 224 DR9, 14 52, 53 DQ5, 925 DR8, 9 53 DQ2, 726 DR17, 14 52 DQ2, 527 DR1, 11 52 DQ5, 628 DR17, 4 52, 53 DQ229 DR11, 4 52, 53 DQ7, 830 DR1, 14 52 DQ5______________________________________
EXAMPLE 5
According to this example, 3 μm latex beads presenting HLA Class I antigens produced according to the methods of example 1 and 5 μm latex beads presenting HLA Class II antigens produced according to the methods of example 4 were mixed to perform an assay to detect the presence of antibodies specific to HLA Class I and Class II antigens. Because the beads presenting HLA Class II antigens are different in size from the HLA Class I beads, the two different sized beads can be electronically distinguished according to their sizes when analyzed on a flow cytometer as illustrated in FIGS. 2a-2d. FIG. 2a-d depict the reaction of the mixture of Class I and Class II beads and their reaction to anti-HLA Class I antibodies (FIGS. 2a and 2b) or anti-HLA Class II antibodies (FIGS. 2c and 2d). When the Class I beads are selected by gating around the 3 μm size, the beads react to the anti-Class I antibody as illustrated in FIG. 2a. When the Class II beads are selected by gating around the 5 μm size, there is no reaction to the anti-Class I antibody as illustrated in FIG. 2b. The reaction pattern of the mixed beads to the anti-class II antibody is the reverse. When Class I beads are selected by gating around 3 μm in size, the beads do not react to the anti-Class II antibody as illustrated in FIG. 2c. When Class II antibodies are selected by gating around 5 μm in size, the Class II antigen beads react to the anti-Class II antibody as illustrated in FIG. 2d.
Numerous modifications and variations in the practice of the invention are expected to occur to those skilled in the art upon consideration of the foregoing description on the presently preferred embodiments thereof. Consequently, the only limitations which should be placed upon the scope of the present invention are those that appear in the appended claims.
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The present invention provides an improved method for detection of panel reactive antibodies in serum of a subject against HLA class I antigens, which comprises the steps of adding serum from a subject to an array of microbeads, each microbead presenting HLA antigens from a cell population presenting the same HLA antigens; incubating the serum and microbeads for sufficient time for anti-HLA antibodies in the serum to bind to the HLA antigens presented on the microbeads; removing the serum components which do not specifically bind with the HLA antigens presented on the microbeads; incubating the microbeads with a labeled ligand capable of specifically binding with anti-HLA antibodies bound to said HLA antigens; removing the labeled ligand which is not bound to said HLA antigens; and detecting the presence of labeled ligand bound to said HLA antigens by flow cytometry.
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[0001] This application is a continuation-in-part (CIP) of U.S. patent application Ser. No. 10/437,305, filed May 14, 2003, which is a divisional of U.S. patent application Ser. No. 09/993,912, filed Nov. 27, 2001, now U.S. Pat. No. 6,582,886.
FIELD OF THE INVENTION
[0002] The present invention relates to an improved solvent and process for the production of flexographic printing plates crosslinked by photopolymerization. More specifically, the invention relates to a solvent system using alkyl esters, alone or in combination with co-solvents and/or non-solvents, as washout solvents for the unpolymerized material in the printing plates to develop a relief image and a method for developing printing plates.
BACKGROUND OF THE INVENTION
[0003] Washout processes for the development of photopolymerizable flexographic printing plates are well known and is described in detail in U.S. Pat. No. 5,240,815 which is incorporated herein by reference. Ordinarily, exposed plates are washed (developed) in a developing solvent that can remove the unpolymerized material while leaving the polymerized (cured) material intact. The solvent typically used in such processes include: (a) chlorohydrocarbons, such as trichloroethylene, perchloroethylene or trichloroethane, alone or in a mixture with a lower alcohol, such as n-butanol; (b) saturated cyclic or acyclic hydrocarbons, such as petroleum ether, hexane, heptane, octane, cyclohexane or methylcyclohexane; (c) aromatic hydrocarbons, such as benzene, toluene or xylene; (d) lower aliphatic ketones, such as acetone, methyl ethyl ketone or methyl isobutyl ketone; and (e) terpene hydrocarbons, such as d-limonene.
[0004] One important disadvantage of the known solvents and the procedures for their use is that the solvents being used as developers may act too slowly, cause swelling of the plates and/or cause damage to the fine detail in the plate by undercutting and/or pinholing. Moreover, when non-chlorinated solvents are used in the washout process, long drying times may be necessary. Furthermore, many of these solvents have flashpoints of less than 100° F., so that the process can only be operated in special, explosion-protected plants. Many of the prior art solvents are considered Hazardous Air Pollutants (HAPS), and are subject to stringent reporting requirements. When chlorohydrocarbons and other toxic chemicals are used, their toxicity also gives rise to disposal problems and worker safety issues.
[0005] An essential step to any photopolymerizable relief printing process is the development of the printing plate after the image is formed through imagewise exposure of the photopolymerizable plate to light. The image is formed by polymerizing and crosslinking of the photopolimerizable material that is exposed while the unexposed portion remains unpolymerized. Ordinarily, development is accomplished by washing the exposed plate in a solvent which can remove the unpolymerized material while leaving the polymerized (cured) material intact. Since such plates can be formed from a variety of materials, it is necessary to match a specific plate with an appropriate solvent. For example, U.S. Pat. Nos. 4,323,636, 4,323,637, 4,423,135, and 4,369,246, the disclosures of which are incorporated herein by reference, disclose a variety of photopolymer printing plate compositions based on block copolymers of styrene and butadiene (SBS) or isoprene (SIS). These compositions can be utilized to produce printing plates which can be developed by a number of aliphatic and aromatic solvents, including methyl ethyl ketone, toluene, xylene, d-limonene, carbon tetrachloride, trichloroethane, methyl chloroform, and tetrachloroethylene. These solvents may be used alone or in a mixture with a “non-solvent” (i.e. a substance that cannot dissolve unpolymerized materials), for example, trichloroethane with ethanol. In any case, during the development step, the solvent can be applied in any convenient manner such as by pouring, immersing, spraying, or roller application. Brushing, which aids in the removal of the unpolymerized or uncrosslinked portions of the composition, can also be performed to facilitate the processing of the plate.
[0006] Similarly, UK 1,358,062 discloses photosensitive compositions consisting of a nitrile rubber with an addition of photopolymerizable tri- or tetra-unsaturated ester derived from acrylic or methacrylic acid combined with an addition polymerization initiator activated by actinic radiation. Plates made from this composition can be developed by organic solvents including aliphatic esters such as ethyl acetate, aliphatic ketones such as acetone, methyl ethyl ketone, d-limonene, halogenated organic solvents, such as chloroform, methylene chloride, CFC 113 or blends of such solvents. Brushing or agitation can be used to facilitate the removal of the non-polymerized portion of the composition.
[0007] U.S. Pat. No. 4,177,074 discloses a photosensitive composition containing a high molecular weight butadiene/acrylonitrile copolymer which contains carboxyl groups, a low molecular weight butadiene polymer which may or may not contain carboxyl groups, and an ethylenically unsaturated monomer, combined with a free-radical generating system. This composition is also used as the polymer layer of a flexographic printing plate and requires processing with such organic solvents as methyl ethyl ketone, benzene, toluene, xylene, d-limonene, trichloroethane, trichlorethylene, methyl chloroform, tetrachloroethylene, or solvent/non-solvent mixtures, e.g., tetrachloroethylene and n-butanol. The composition may also be processed with water-soluble organic solvents in an aqueous basic solution, such as sodium hydroxide/isopropyl alcohol/water; sodium carbonate/isopropyl alcohol/water; sodium carbonate/2-butoxyethanol/water; sodium borate/2-butoxyethanol/water; sodium silicate/2-butoxyethanol/water; sodium borate/2-butoxyethanol/water; sodium silicate/2-butoxyethanol/glycerol/water; and sodium carbonate/2-(2 -butoxyethoxy) ethanol/water.
[0008] U.S. Pat. No. 4,517,279, the disclosure of which is incorporated herein by reference, discloses a photosensitive composition containing a high molecular weight butadiene acrylonitrile copolymer which contains carboxyl groups, and a high molecular weight butadiene/acrylonitrile copolymer which does not contain carboxyl groups, combined with ethylenically unsaturated monomer and a free radical generating system. That composition, which is also used as the polymer layer of a flexographic printing plate, requires processing by blends of tetrachloroethylene and a non-solvent. The composition may also be processed in mixtures of sodium hydroxide/isopropyl alcohol/water; sodium carbonate/2-butoxyethanol/water; sodium silicate/2-butoxyethanol/water; sodium carbonate/2-butoxyethanol/glycerol/water; and sodium hydroxide/2-(2-butoxyethoxy)ethanol/water.
[0009] As can be seen from the foregoing examples of the prior art, the solvents needed for image development will vary depending on the composition of the polymer layer of the plate. The need for different solvent systems is particularly inconvenient, especially if different photopolymer systems are being processed at the same facility. Furthermore, many of the solvents used to develop the plates are toxic or suspected carcinogens. Thus, there exists a real need for solvent systems which can be used with a greater degree of safety. In addition, there exists a need for solvent systems which can be used in a variety of plates. U.S. Pat. Nos. 4,806,452 and 4,847,182, the disclosures of which are incorporated herein by reference, disclose solvent developers for flexographic plates containing terpene hydrocarbons such as d-limonene which are effective on a variety of plate types. These terpene hydrocarbon-based developers are also non-toxic. However, they have proven to be hazards in the workplace because of their tendency to spontaneously combust thereby causing fires.
[0010] Therefore, commonly assigned U.S. Pat. No. 6,248,502 solves the drawbacks of terpene by using terpene esters as a substitute developing solvent. Because terpene ester has a higher flash point, the fire risk is greatly decreased. However, terpene esters tends to breakdown through repeated distillation which limits the recyclability of the solvent.
[0011] The present invention relates to an environmentally friendly developing solvent that offers improvement over the prior art. The solvent comprises alkyl esters which have higher flash points when compared to current solvents. For example, d-limonene (a terpene), terpene ester, and alkyl ester have a flash points of 120° F., 141° F., and >250° F., respectively. By having a high flash point, alkyl esters offer superior safety in addition to low toxicity, reduced cost, and biodegradability. Furthermore, compared developing solvents of the prior art including terpene ester, alkyl ester causes less plate swelling. Therefore, more alkyl esters (up to 70% by volume) can be used in the developing solvent resulting in faster removal rate of the non-polymerized portion of the plate.
SUMMARY OF THE INVENTION
[0012] The present invention comprises solvents for use in the processing of a wide variety of photopolyrneric materials used to form photopolymer printing plates. These solvents, which comprise alkyl esters either alone or in the presence of other organic materials (co-solvents and non-solvents), can be used with a variety of polymeric systems. The alkyl esters are natural products with low toxicity and are relatively safe to use compared with other solvent systems. Alkyl esters, it has been discovered, provide a unique combination of reduced cost, improved plate quality, low volatility, improved regulatory compliance, low toxicity, reduced washout time, and biodegradability.
[0013] It is, therefore, an object of the present invention to provide a solvent system and a process for the preparation of relief plates crosslinked by photopolymerization, in which the washout time and the drying time are substantially shorter compared with the conventional process solvents, and wherein the relief plates suffer neither excessive surface swelling nor under-washing and are characterized by improved relief depths and sidewall structure.
[0014] Another object of the present invention is to provide a process for the preparation of relief plates crosslinked by photopolymerization which is capable of operation without expensive explosion protection.
[0015] It is another object of the present invention to provide solvent systems for use with photopolymeric printing plates which overcome the spontaneous combustion problems of the prior art solvent systems.
[0016] It is another object of the present invention is to provide solvent systems which minimizes workplace hazards and requires minimal regulatory reporting.
DETAILED DESCRIPTION OF THE INVENTION
[0017] The present invention comprises alkyl ester solvents for use in photopolymer printing plate processing. The alkyl esters, which can be used either alone or in a blended form with co-solvents or non-solvents, can be used to develop a number of different photopolymer printing plates. As used herein, co-solvents are non-alkyl ester compounds that can also dissolve the non-polymerized material; and non-solvents are compounds that cannot dissolve the non-polymerized material. The alkyl esters have the general formula RCOOR′, where R can be any organic moiety, and R′ is an alkyl group, preferably having 1 to 12 carbon atoms. R′ can also be a linear or branched alkyl group. Thus, the preferred alkyl esters for this invention includes methyl esters, ethyl esters, propyl esters, butyl esters, pentyl esters, hexyl esters, octyl esters, nonyl esters, decyl esters, undecyl esters, dodecyl esters, and any branched compound thereof including isopropyl esters, isobutyl esters, etc. A wide variety of alkyl esters are suitable for use in the solvents of this invention including, but not limited to, alkyl esters of fatty acids with 8-18 carbons. An especially preferred alkyl ester is methyl hexadecanoate.
[0018] Mixtures of alkyl esters can also be used and may show synergistic effects when compared with a alkyl ester used alone. When a combination of two or more alkyl esters is used, the resulting blend is often more effective as a solvent than the individual alkyl esters. This blend is referred to herein as a MAE (Mixed Alkyl Ester) solvent.
[0019] Various co-solvents (non-alkyl ester compounds that can also, by themselves, dissolve the non-polymerized material) and non-solvents (compounds that cannot, by themselves, dissolve the non-polymerized material) can also be employed with the alkyl esters and MAE according to the invention. Suitable co-solvents include, but is not limited to, n-butanol, 2-ethoxyethanol, benzyl alcohol, ethanol, methanol, propanol, isopropanol, alpha terpineol, dipropylene glycol methyl ether, 2-butoxyethanol, isopropyl alcohol, and 2-(2-butoxyethoxy) ethanol, cyclopentanol, cyclohexanol, cycloheptanol, substituted cyclopentanol, substituted cyclohexanol, substituted cycloheptanol, cyclopentyl substituted alcohol, cyclohexyl substituted alcohol, and cycloheptyl substituted alcohol.
[0020] The co-solvent should be soluble in the alkyl ester or MAE, should have suitable dissolving properties towards the non-photolysed (non-polymerized) portions of the plate that are to be dissolved, should have low toxicity and acceptable safety profiles, and should be readily disposable. The co-solvents are used to modify the properties of the solvent blend. This includes, for example, the addition of co-solvents to aid in the removal of the top protective cover skin on the flexographic plate. In addition, several of the co-solvents, such as terpene alcohols, in particular alpha terpineol, serve as stabilizers to prevent the separation of the solvent blend, which can occur at reduced temperatures. This stabilizer property of the co-solvent becomes important when isoparaffinic hydrocarbons are used as the non-solvent and benzyl alcohol is used as a co-solvent to remove the outer layer of the photopolymerizable printing plate since the benzyl alcohol may separate from the alkyl esters and paraffinic hydrocarbon mixture. Further, the mixture of alkyl esters and co-solvent is often more effective as a solvent than the individual alkyl esters by itself.
[0021] The non-solvent should be miscible with the alkyl ester or alkyl esters and the co-solvents, should have acceptable toxicity and safety profiles, and should be readily disposable or recyclable. The non-solvent are typically used as a filler to reduce cost, therefore, recyclability of the non-solvent material is highly desirable. Suitable non-solvents include, but is not limited to, petroleum distillates, such as aliphatic petroleum distillates, naphthas, paraffinic solvents, hydrotreated petroleum distillates, mineral oil, mineral spirits, ligroin, decane, octane, hexane and other similar materials. Isoparaffinic solvents are commercially available in a wide range of volatility and corresponding flash points. The developing solvent of the invention can made with a wide range of commercially available isoparaffinic solvents as its non-solvent base. The following table shows volatilities and properties of commercially available isoparaffinic solvents suitable for use with the invention.
TABLE 1 Volatility Flash Point (° F.) 106 129 135 147 196 Initial Boiling Point (° F.) 320 352 350 376 433 50% Dry Point (° F.) 331 360 365 383 460 345 370 386 405 487 Vapor Pressure (mm Hg @ 100° F.) 14 6.2 5.7 5.2 3.1
[0022] Parameters such as drying rates, fire risk, workplace air quality and volatile organic compound emissions will also play a role in the selected non-solvent choice.
[0023] In addition, in a commercially acceptable product, odor masking materials or perfumes are often added. Such odor masking materials or perfumes can include terpenes to impart a clean, fresh odor.
[0024] The developing solvent components can be varied but a suitable composition would be about 30-75% by volume of at least one alkyl ester and preferably a mixture of alkyl esters, about 20-60% by volume of a first co-solvent capable of dissolving the top protective cover layer of the flexographic plate, about 5-35% by volume of a second co-solvent. Optionally less than about 2% by volume of a perfume or odor masking material can be added to the solvent; however, it is important that the perfume must not adversely affect the function of the solvent. A non-solvent can also be included in the solvent in an amount up to about 45% by volume. A preferred composition would be about 50-70% by volume of at least one alkyl ester and preferably a mixture of alkyl esters, about 20-50% by volume of a first co-solvent capable of dissolving the top protective cover layer of the flexographic plate, about 10-30% by volume of a second co-solvent. A non-solvent can also be included in the preferred mixture in an amount up to about 20% by volume. The preferred co-solvents are 2-ethylhexanol and cyclohexanol; and the preferred non-solvent is an isoparaffinic hydrocarbon. The following solvents are especially preferred: 1) about 70% methyl hexadecanoate, about 20% 2-ethylhexanol, and about 10% cyclohexanol; 2) about 80% propyl tetradecanoate and about 20% dodecanol; 3) about 75% isopropyl hexadecanoate and about 25% benzyl alcohol; 4) about 80% ispropyl tetradecanoate and about 20% cyclohexylethanol; and 5) about 75% ethyl hexadecanoate and about 25% dodecanol.
[0025] The alkyl ester solvents may be substituted for the synthetic hydrocarbon, oxygenated solvents or halogenated hydrocarbon solvents used for processing photopolymer printing plates. For example, the alkyl ester solvents are suitable in the processing of photopolymer printing plates based on block copolymers of styrene and butadiene (SBS) or styrene and isoprene (SIS), copolymers of butadiene and acrylonitrile, terpolymers of butadiene, acrylonitrile and acrylic acid and other similar photopolymers. The alkyl ester solvents can be applied to the plates by any conventional application means including spraying, brushing, rolling, dipping (immersing) or any combination thereof. The alkyl ester solvents also produce photopolymer plates with less cured polymer image swelling than those processed in conventional hydrocarbon or chlorinated hydrocarbon solvents. Since swelling tends to distort the image formed, this surprising result permits clear, sharp images to be formed at much lower exposure times than those resulting from the use of conventional solvents. Additionally, the solvents of the invention have fairly low volatility which reduces worker exposure during plate processing. Furthermore, because alkyl esters are natural products, they are much less toxic and are more readily biodegradable than synthetic hydrocarbon or chlorinated hydrocarbon solvents.
[0026] The following examples are given to illustrate the present invention. It should be understood that the invention is not to be limited to the specific conditions or details described in these examples.
EXAMPLE 1
Plate Preparation
[0027] Plates were made of Dupont 112 TDR, a photopolymerizable material. The plate sizes are as follows: plate #1) 24″×52″, plate #2) 27″×42″, and plate #3) 50″×55″. Each plate was exposed on the backside for 95 seconds and on the front for 700 seconds.
EXAMPLE 2
Development
[0028] The plates were developed using a solvent blend of about 70% of methyl hexadecanoate, about 20% 2-ethylhexanol, and about 10% cyclohexanol. The plates were processed at 50 mm per minute processor speed for plates #1 and #2 and 85 mm per minute for plate #2, and at brush pressure of 1 mm down pressure for all three plates.
EXAMPLE 3
Swell and Dry Times
[0029] The following tables gave the face and floor thickness of each plate after development with the developer of Example 2 (all measurements were given in {fraction (1/1000)} inch). The plates measurements were checked at random locations on the plate. The plates were dried to the correct gauge for the plate before final measurements were taken.
TABLE 2 Plate #1 Just before After 15 min. After 40 min. drying in plate dryer in plate dryer Face Floor Face Floor Face Floor 0.118 0.056 0.115 0.052 0.114 0.042 0.117 0.056 0.114 0.040 0.113 0.030 0.118 0.048 0.114 0.036 0.113 0.037 0.117 0.034 0.117 0.043 0.115 0.038 0.117 0.040 0.116 0.049 0.112 0.046 Average 0.1174 .0468 0.1152 0.0440 0.1134 0.0386
[0030] [0030] TABLE 3 Plate #2 Just before After 60 min. drying in plate dryer Face Floor Face Floor 0.118 0.063 0.112 0.049 0.118 0.057 0.112 0.044 0.118 0.046 0.112 0.036 0.118 0.043 0.112 0.030 0.118 0.060 0.113 0.034 — — 0.113 0.041 Average 0.1180 0.538 0.1123 0.0390
[0031] [0031] TABLE 4 Plate #3 Just before After 60 min. drying in plate dryer Face Floor Face Floor 0.116 0.062 0.114 0.049 0.115 0.056 0.113 0.044 0.115 0.040 0.113 0.036 0.115 0.043 0.112 0.030 0.116 0.046 0.112 0.034 — — 0.113 0.041 Average 0.1154 0.0494 0.1128 0.0390
[0032] The data clearly showed faster drying times when compared to developing solvents of the prior art. The drying times using the alkyl ester solvent of Example 2 were less than 60 minutes while typical drying times of prior art solvents were about 90 to 180 minutes. For example, the drying times of the terpene ester solvent disclosed in U.S. Pat. No. 6,248,502 were from 70 to 160 minutes.
[0033] The invention has been disclosed broadly and illustrated in reference to representative embodiments described above. Those skilled in the art will recognize that various modifications can be made to the present invention without departing from the spirit and scope thereof.
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Flexographic printing plates are produced by exposing the photopolymer plates to a light source and washing out (developing) the masked out, non-exposed areas with a solvent. The invention provides alkyl ester solvents suitable for use in the development of photopolymer printing plates. The solvents, which include alkyl esters alone or mixed with co-solvents and/or non-solvents, are effective in developing a large number of different photopolymer printing plates and can produce images superior to those obtained with commercially available solvents currently used in such applications.
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BACKGROUND OF THE INVENTION
This invention relates generally to parabolic trough solar energy collectors.
Solar energy collectors have long been known. They generally comprise concentrating and non-concentrating collectors. The former class includes flat plate collectors which operate at relatively low temperatures and do not concentrate the solar energy. The latter class includes various types of collectors which concentrate or focus solar energy onto a given area or line and are capable of operating at higher temperature. The latter type has included parabolic trough collectors of various configurations.
A drawback with the prior collectors is that they are not cost effective. The cost of the installation and of the reflector exceeds the savings realized by the utilization of solar energy as compared to the use of conventional fuel such as gas, oil or electricity. Furthermore, such reflectors have not been suitable for extended usage under the environmental conditions to which they are subjected for year-round operation. Furthermore, prior devices have been cumbersome to transport and expensive and difficult to erect at the site.
OBJECTS AND SUMMARY OF THE INVENTION
It is an object of the present invention to provide a cost effective parabolic trough solar energy collector.
It is another object of the present invention to provide a parabolic trough solar collector which is simple in construction and easy to erect at the site.
It is a further object of the present invention to provide a parabolic trough solar collector in which the reflecting surface has high predictable accuracy.
It is still another object of the present invention to provide a solar collector which is capable of mass production.
The foregoing and other objects are achieved by a solar reflector comprising an elongated rib support, a plurality of ribs formed of sheet material secured to and extending outwardly from said support with the upper edges of said ribs defining a parabolic trough surface, a thin reflecting sheet disposed to contact said edges of said ribs and to be supported thereby to form a parabolic trough reflection, retainer means cooperating with the edges of the reflective sheet serving to secure the sheet to the ribs and force the sheet against the upper edges thereof to conform the sheet to the parabolic surface, and means for presenting fluid to be heated along the focal line of said parabolic trough reflector.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a parabolic trough reflector in accordance with the present invention.
FIG. 2 is a sectional view taken along the line 2--2 of FIG. 1 showing the support and support ribs and reflecting surface.
FIG. 3 is an elevational view of a plurality of reflectors of the type shown in FIGS. 1 and 2 supported and driven by a common drive.
FIG. 4 is a sectional view taken generally along the line 4--4 of FIG. 3 and line 4--4 of FIG. 5.
FIG. 5 is a sectional view taken along the line 5--5 of FIG. 4 showing the system for driving & tracking the sun.
FIG. 6 is an elevational view taken along the line 6--6 of FIG. 3 showing a typical support system.
FIG. 7 is an enlarged view taken generally along the line 7--7 of FIG. 6 and showing the support for the solar reflector system.
FIG. 8 is a schematic diagram of the solar tracking system employed in the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to FIGS. 1 and 2, there is shown a parabolic trough solar reflector 10 in accordance with the present invention. More particularly, the solar reflector includes an elongated rib support such as tube 11 which extends the length of the parabolic reflector. Support flanges 12 and 13 are secured to the ends of the support tube 11 and are adapted to receive the end ribs 14 and 16 which may be suitably attached to the flange by means of rivets or bolts. Disposed and spaced along the intermediate portion of the support tube 11 are a plurality of flanges 17, each of which is adapted to have secured thereto and extend outwardly therefrom intermediate ribs 18. Each of the ribs 14, 16 and 18 are identical in their construction and are made of thin sheet material, such as steel, with their end portions including a bent tab 19. The rib bottom includes a bend edge portion or lip 21. The upper edges of the ribs each define a parabola. A thin sheet of reflecting material 22 is placed to contact the upper edges of the thin ribs. The sheet 22 has its ends bent at right angles to form a lip such as shown at 23. Retainers 24 are suitably secured to the tabs 19 by means of screws, bolts or other suitable attachments 26 whereby the retainers are urged against the confronting face of the lips 23 to force the sheet 22 into intimate contact with the adjacent upper edges of the ribs. This causes the sheet to contour to the parabolic edges of the ribs and define a reflecting trough surface. Because of the thinness of the adjacent edge of the ribs, the thin sheet is in intimate contact and will be so maintained as long as there is pressure from the retainers. It is advantageous but not necessary to provide a cover such as the cover 27 which is suitably secured to lip portions 21 of the ribs by means of screws or bolts 28. This protects the back surface of the reflecting sheet and the ribs against the environment.
The advantage of the system just described is that the plurality of the ribs may be easily formed by stamping or machining in large quantities and then at the site attached to the flanges 17 to form the rib-like assembly for receiving the reflector sheet 22. It is apparent that the assembly is relatively light in construction and yet is rather sturdy because of the support provided by the elongated member 11 and the outwardly extending ribs having their ends secured to the retainer. The assembly is reinforced by the thin sheet 22 which prevents and minimizes shearing action. The trough reflector is relatively sturdy, much as the wings or fuselage of an airplane.
Referring to FIG. 3, there is shown a plurality of parabolic trough reflectors 10 supported by a plurality of posts 32. A central drive means 33 drives the plurality of reflectors in unison to track the sun. Referring more particularly to FIGS. 4-7, the support and drive system is illustrated in detail. The support system comprises posts 32 each having their bottom suitably secured to a plate 34. The plate may be attached to a concrete foundation element or other support. Brackets 36 may be provided to reinforce each of the posts. The upper end of each of the outer posts 32 supports a plate 37 which carries three spaced roller bearings 38 which engage a short hollow shaft 39. It is noted that the shafts 39 are free to move longitudinally with respect to the bearings 38. A support plate 41 is connected to the central post. The plate 41 includes roller bearings 42 which ride in the groove 43 formed in shaft 44. This prevents any longitudinal movement of the shaft with respect to its bearings. The arrangement of the outer support shafts 39 which are free to move in relation to their support bearings 38 provides means whereby thermal expansion of the system due to solar radiation is accommodated while maintaining the central drive portion in intimate relationship with its drive means.
The support plate 41 extends downwardly and receives motor and drive mounting brackets 46 and 47. Referring now more particularly to FIGS. 4 and 5, the drive means for driving the reflector is shown in more detail. The drive means includes a gear 46 driven by a worm gear 45. The worm gear is driven by reversible motor 48 via a belt or other suitable drive 49 which extends between the drive pulley 51 and pulley 52. The driven gear 46 is suitably attached to the shaft 44 whereby when the motor is energized, the shaft is driven by the driven gear 46.
The ends of the shafts 39 and 44 are provided with plates 53. The plates 53 are suitably attached to the ends of the shaft as by welding or screws. The plates extend downwardly to receive the end support flanges 12 and 13 of associated cylindrical supports 11. Thus, as the worm gear is driven, the support shaft 11 is rotated about an axis which corresponds to the axis of the shafts 39 and 44. The reflectors are moved to scan different portions of the sky. The opposite ends of the support tube 11 associated with the driven shaft 44 are connected to plates 53 which then cause the associated shaft 39 to rotate. The opposite ends of the shaft 39 accommodate similar plates 53 which are suitably attached to the flanges 11 and 12 of the ends of the associated supports 11. In this manner, a plurality of reflectors are supported and driven.
A support bracket 56 is secured to the driven gear. The bracket 56 is adapted to receive and support the fluid conduit assembly 61 which presents the fluid to the focal line of the parabolic trough reflector. The support 56 is suitably attached to the upper end of the gear as, for example, by means of studs 57. Each of the support shafts 39 includes supports 58 which extend upwardly and serve to receive the fluid conduit assembly 61.
The fluid conduit assembly 61 extends the length of the total reflector assembly and is supported by the supports 56 and 58. The conduit is disposed along the focal line of the parabolic trough reflectors. The conduit assembly 61 includes an inner conduit 62 which may be stainless steel coated with black paint or black chromium over a nickel plate. To minimize convective losses, a transparent jacket such as the Pyrex tube 63 surrounds or encloses the receiver or main tube 62. Since there may be a difference in thermal expansion between the tubes 62 and 63 made of different materials, the central tube 62 is continuous and supported by spaced insulating rings 64 disposed at each of the supports. The rings 64 are supported by cooperating flanges 66, 67 suitably attached to the ends of the supports. The insulating rings contact the adjacent ends of the ceramic or Pyrex outer tubing and permit it to expand longitudinally while it is supported by the flanges 66, 67. Thus, there is provision for differential expansion between the outer tube 63 and inner tube 62. Furthermore, it is to be observed that each of the tubes is supported in such a manner as to allow expansion of the assembly whereby the spacing between the supports varies.
The support 56 additionally supports a solar tracking means. The tracking means comprises shadow vane 71, a pair of main photocells 72 and 73, a pair of desteer photocells 74 and 76 and gross error photocell 77 connected via switch 78 to amplifier 79. The amplifier is connected to control a motor drive such as triac motor drive 81 which drives the reversible motor 48.
The main photocell pair are connected in opposition and give no output when they are equally illuminated whereby the reflector is tracking the sun and the reflectors provide energy to the fluid conducted in the receiver tube 62. The desteer photocells are switched into the system to steer the image of the sun off of the receiver tube during malfunction such as fluid pump failure. The gross error photocell is provided to reacquire the sun with gross alignment.
Thus, there has been provided an improved parabolic trough solar energy collector assembly which is simple in construction, easy to erect on site, and inexpensive to manufacture.
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A parabolic trough solar energy collector including an elongated support with a plurality of ribs secured thereto and extending outwardly therefrom. One surface of said ribs is shaped to define a parabola and is adapted to receive and support a thin reflecting sheet which forms a parabolic trough reflecting surface. One or more of said collectors are adapted to be joined end to end and supported for joint rotation to track the sun. A common drive system rotates the reflectors to track the sun; the reflector concentrates and focuses the energy along a focal line. The fluid to be heated is presented along the focal line in a suitable pipe which extends therealong.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a multi-function face protector, more particularly, to a face protector having a protective shade that enables the worker to perform welding as well as grinding while wearing the multi-function face protector and that can be used with safety glasses, goggles and a mask.
[0003] 2. Description of the Related Art
[0004] Generally, a face protector protects the face of the worker from materials scattered toward the worker during a certain process in the factory and the industrial field. The face protector can be used in processes such as cutting, drilling, mining and power woodworking in which scattered materials of high impact energy are generated. Further, the face protector can be used for cases such as grinding, machining, woodworking and lumbering in which scattered materials of relatively low impact energy may be generated. Yet further, the face protector can be used in processes such as furnacing iron, nonferrous metal or glass in which scattered materials of molten state may be generated. Yet further, the face protector can be used in processes in which scattered materials of liquid or floating dust may be generated.
[0005] The face protector is commonly divided into a type in which the face protector can be worn on the head of the worker and a type in which the face protector can be placed on a safety cap. The face protector placed on the safety cap is secured to the safety cap mainly by a frame and springs connecting the opposite ends of the frame. On a lower portion of the frame, a transparent or translucent protective plate is secured by rivets or the like.
[0006] The face protector includes springs, the rivet and other components which are made of metals having relatively heavy weight, so that the weight of the face protector is quite heavy. Thus, when using the face protector for a long time, there is a problem that the user becomes fatigued by the weight of the face protector. Further, when using the face protector for a long time, there is another problem that it is difficult to change only the protective plate in a case that the protective plate is scratched by the scattered materials.
[0007] The face protector has a wide field of view, but needs a separate shield for shading the light generated from welding.
SUMMARY OF THE INVENTION
[0008] The present invention has been made to solve the above problems, and it is an object of the present invention to provide a face protector having a protective shade that enables the worker to perform welding as well as grinding while wearing the multi-function face protector and that can be used with safety glasses, goggles and a mask.
[0009] Another object of the present invention is to provide the face protector having a protective shade of a novel structure capable of easily changing a shield plate and a protective shade plate, and capable of minimizing a weight felt by the worker when used by reducing the weight of it.
[0010] Yet another object of the present invention is to provide the face protector having a protective shade wherein a bottom of the shield plate is expanded so as to protect the neck as well as the whole face.
[0011] In accordance with one aspect of the present invention, the above and other objects can be accomplished by the provision of a multi-function face protector including a head band, a forehead cover, and a face shield, the face shield comprising: resilient hooks formed at the upper central portion of the face shield; and engaging portions formed at the opposite ends of the face shield respectively, and the forehead cover comprising: shield couplings formed at the central portion of the inner surface of the forehead cover; and projections formed at the opposite ends of the inner surface of the forehead cover respectively, wherein, the resilient hooks of the face shield are engaged with the respective shield couplings of the forehead cover.
[0012] The forehead cover further comprises guide grooves formed at the opposite sides of the forehead cover respectively so as to easily couple the face shield with the forehead cover.
[0013] The forehead cover has connector couplings formed at the opposite ends of its inner surface respectively, and the protective shade has connectors coupled with the opposite ends of its inner surfaces, wherein the connectors are engaged with the connector couplings respectively.
[0014] The face shield is configured so that its full surface may be three-dimensionally protruded like a human face, and increases in width toward its lower portion so that it may cover and protect the neck of the worker while working.
[0015] Each of the connectors has U-shape when viewed from the front side, each of the connectors is provided with an inserting projection and guide projections on its inner side, wherein each of the connectors is engaged with each of the connector couplings of the forehead cover by the inserting projection and the guide projections, each of the connectors is provided with plural indents on its outer side, and into the plural indents, hinging projections of the protective shade are inserted, wherein the protective shade stepwise hinges about the plural indents.
[0016] Each of the connectors is further provided with a reinforcing projection 30 - 1 on its outer side so as to enhance the resilience of the plural indents.
[0017] The hinging projections of the protective shade are provided with an 8-shaped separation-proof projection.
[0018] Each of the hinging projections is provided with an independent separation-proof projection.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The foregoing and other objects and features of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:
[0020] FIG. 1 is a perspective view illustrating a multi-function face protector in accordance with a preferred embodiment of the present invention;
[0021] FIG. 2 is a view illustrating a combined state of a forehead cover and a face shield of the multi-function face protector in accordance with a preferred embodiment of the present invention;
[0022] FIG. 3 is a sectional view of the multi-function face protector in accordance with a preferred embodiment of the present invention;
[0023] FIG. 4 is a view illustrating a separated state of a coupling and a connector coupling of the multi-function face protector in accordance with a preferred embodiment of the present invention;
[0024] FIG. 5 is a perspective view of the connector coupling of the multi-function face protector in accordance with a preferred embodiment of the present invention;
[0025] FIG. 6 is a side perspective view of the connector coupling of the multi-function face protector in accordance with a preferred embodiment of the present invention;
[0026] FIG. 7 is a side perspective view of the connector coupling of the multi-function face protector in accordance with a preferred embodiment of the present invention;
[0027] FIG. 8 is a side perspective view of the connector coupling of the multi-function face protector in accordance with another preferred embodiment of the present invention;
[0028] FIG. 9 is a view illustrating a combined state of the face shield of the multi-function face protector in accordance with a preferred embodiment of the present invention; and
[0029] FIG. 10 is a view illustrating operating states of the protective shade of the multi-function face protector in accordance with a preferred embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0030] Preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, in which like components are denoted by the same reference numerals, and repetitious descriptions thereof will be omitted.
[0031] A multi-function face protector of the present invention is shown in FIGS. 1 to 10 . The multi-function face protector includes a head band 230 , a forehead cover 200 , and a face shield 130 . The forehead cover 200 and the face shield 130 are configured such that the face shield 130 is easily coupled with and separated from the forehead cover 200 .
[0032] The face shield 130 includes resilient hooks 120 formed at its upper central portion, and engaging portions 110 formed at its opposite ends respectively, so as to couple with the forehead cover 200 .
[0033] The forehead cover 200 includes shield couplings 140 and projections 150 . The shield couplings 140 are formed at the central portion of the inner surface of the forehead cover 200 . The projections 150 are formed at the opposite ends of the inner surface of the forehead cover 200 respectively.
[0034] The resilient hooks 120 of the face shield 130 are engaged with the respective shield couplings 140 of the forehead cover 200 . The opposite engaging portions 110 of face shield 130 are engaged with projections 150 of the forehead cover 200 respectively.
[0035] The forehead cover 200 further includes guide grooves 160 . The guide grooves 160 are formed at the opposite sides of the forehead cover 200 respectively so as to easily couple the face shield 130 with the forehead cover 200 .
[0036] In such a configuration, when the face shield 130 is coupled with the forehead cover 200 , the engaging portions 110 are engaged with the opposite projections 150 respectively, and then, the engaging portions 110 are pushed and inserted into the guide grooves 160 respectively.
[0037] Herein, the resilient hooks 120 are engaged with the shield couplings 140 of the forehead cover 200 respectively, so that each of the resilient hooks 120 is closely inserted into each of the shield couplings 140 by its resilience.
[0038] As such, the forehead cover 200 and the face shield 130 are closely coupled with each other. When separating the face shield 130 from the forehead cover 200 , the forehead cover 200 and the face shield 130 are operated reversely to the coupling process. For instance, each of the resilient hooks 120 is depressed and drawn from each of the shield couplings 140 , so that each of the resilient hooks 120 is separated from each of the shield couplings 140 . Then, the engaging portions 110 are drawn from the respective opposite projections 150 , so that the face shield 130 is completely separated from the forehead cover 200 .
[0039] In such a way, the face shield 130 is coupled with and separated from the forehead cover 200 .
[0040] Further, the head band 230 includes a size adjuster 210 at its upper end. The size adjuster 210 may adjust vertical circumferential size of the head band 230 according to the vertical circumferential size of the user's head. Thus, the size adjuster 210 may adjust the head band 230 so that eyes of the user are positioned at the central portion of the lens of the face shield.
[0041] The head band 230 also includes an adjusting lever 220 . The adjusting lever 220 may adjust a horizontal circumferential size of the head band 230 according to the horizontal circumferential size of the user's head.
[0042] The forehead cover 200 is coupled with the head band 230 by screws 190 at its opposite sides.
[0043] The forehead cover 200 of the present invention has stepped portions 170 on its upper sides for aesthetic purpose.
[0044] The face shield 130 of the present invention is configured so that its full surface may be three-dimensionally protruded like a human face. Further, the face shield 130 of the present invention increases in width toward its lower portion so that it may cover and protect the neck of the worker while working.
[0045] Further, the forehead cover 200 may be coupled with a protective shade 80 . The protective shade 80 and the forehead cover 200 are configured so that the protective shade 80 is stepwise raised against the forehead cover 200 as shown in FIG. 10 . The forehead cover 200 has connector couplings 90 formed at the opposite ends of its inner surface respectively. The protective shade 80 has connectors 40 coupled with the opposite ends of its inner surface respectively. The connectors 40 are engaged with the connector couplings 90 respectively.
[0046] Each of the connectors 40 has U-shape when viewed from the front side as is apparent from FIGS. 6 and 7 .
[0047] Each of the connectors 40 is provided with an inserting projection 10 and guide projections 20 on its inner side. Each of the connectors 40 is engaged with each of the connector couplings 90 of the forehead cover 200 by the inserting projection 10 and the guide projections 20 .
[0048] Each of the connectors 40 is provided with plural indents 30 on its outer side. Into the plural indents 30 , hinging projections 60 of the protective shade 80 are inserted. Thus, the protective shade 80 stepwise hinges about the plural indents 30 . The hinging projections 60 of the protective shade 80 will be described in detail later.
[0049] According to another preferred embodiment of the present invention as shown in FIG. 8 , each of the connectors 40 is further provided with a reinforcing projection 30 - 1 on its outer side so as to enhance the resilience of the plural indents 30 .
[0050] The protective shade 80 has hinging projections 60 that are inserted into and coupled with the plural indents 30 of the connector 40 of the protective shade 80 shown in FIGS. 5 to 8 . When the protective shade 80 is forced to hinge downwardly in the state that the hinging projections 60 are coupled with the plural indents 30 , the hinging projections 60 are stopped at a first position of the plural indents 30 . Herein, the protective shade 80 may be further forced to hinge downwardly, then the hinging projections 60 pass over the first position of the plural indents 30 , and then stop at a second position of the plural indents 30 . By this way, the protective shade 80 operates to hinge in conjunction with three stop positions as shown in FIG. 10 .
[0051] As shown in FIG. 4 , the hinging projections 60 of the protective shade 80 may be also provided with an 8-shaped separation-proof projection 60 - 1 connecting the hinging projections 60 so as to prevent the hinging projections 60 separating from the plural indents 30 . The separation-proof projection 60 - 1 projects laterally from the sides of the hinging projections 60 . Thus, when the hinging projections 60 are coupled with the plural indents 30 , the separation-proof projection 60 - 1 may be engaged with the edge of the plural indents 30 . Thus, the hinging projections 60 may not be separated from the plural indents 30 .
[0052] As shown in FIG. 5 , each of the hinging projections 60 may be provided with an independent separation-proof projection 60 - 1 . Due to the independent separation-proof projection 60 - 1 , contact between the connector 40 and the connecting portion of the hinging projections 60 may be obviated.
[0053] The multi-function face protector of the present invention may be used by optionally coupling with the protective shade if necessary. On use, the protective shade hinges in conjunction with three stop positions, so that the user may use the protective shade with an ability to stop it at necessary positions.
[0054] As is apparent from the above description, according to the present invention, the face shield has a three-dimensional configuration that is integrally molded and ergonomically designed so as to effectively protect the face and the neck of the user. Therefore, the user may use the multi-function face protector conveniently and the multi-function face protector suffers from little heat-deformation.
[0055] Further, according to the present invention, the multi-function face protector can be used with other protectors such as goggles and the mask in the workplaces in which the scattered materials of high impact energy, molten state, and heat may be generated.
[0056] Further, according to the present invention, the multi-function face protector includes the coupling structure for easily changing the face shield, and the protective shade hinging in conjunction with three stop positions, so that the user may use the protective shade with an ability to stop it at necessary positions. Therefore, the user may use the multi-function face protector conveniently and the multi-function face protector is very effective in a safety equipment industry.
[0057] It should be understood that the embodiments and the accompanying drawings as described above have been described for illustrative purposes and the present invention is limited by the following claims. Further, those skilled in the art will appreciate that various modifications, additions and substitutions are allowed without departing from the scope and spirit of the invention as set forth in the accompanying claims.
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Disclosed herein is a face protector having a protective shade that enables the worker to perform welding as well as grinding while wearing the multi-function face protector and that can be used with safety glasses, goggles and a mask. The multi-function face protector includes a head band, a forehead cover, and a face shield. The face shield comprises resilient hooks formed at its upper central portion, and engaging portions formed at its opposite ends respectively. The forehead cover comprises shield couplings formed at the central portion of its inner surface, and projections formed at the opposite ends of its inner surface respectively. The resilient hooks of the face shield are engaged with the respective shield couplings of the forehead cover.
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This is a continuation of application Ser. No. 282,726, filed on Dec. 12, 1988, now abandoned, which is a continuation-in-part of application Ser. No. 236,080 filed Aug. 24, 1988, now U.S. Pat. No. 4,95,787.
This invention relates to an improved process for making ether carboxylic acids and more particularly to processes for making ether carboxylates prepared by a calcium ion catalyzed reaction in alkaline medium of maleic acid salt and a carboxylate salt containing a reactive hydroxyl group. Such reactions are of the type typically referred to as Michael condensation reactions.
Polycarboxylic acids have long been known to be useful, usually in the salt form, as detergent builders or sequestrants. Also, ether carboxylates useful as metal sequestering and detergent builders have been known and are most desirable for their beneficial effects in laundering applications.
While many carboxylate compounds in the prior art have utility as a builder or sequesterant in laundry detergent formulations, it has been found that certain ether carboxylates are more attractive and cost effective for such utility. In the field of detergent builders and sequesterants for laundry detergent formulations low cost of the components is extremely important because it is in a very competitive market. While many ether carboxylate compounds have been found to be useful there is needed more economical manufacturing processes whereby such compounds can be economically produced in large volume.
One example of ether carboxylates is a mixture of polycarboxylic acids or salts thereof, particularly the sodium salts, of 1-hydroxy-3-oxa-1, 2, 4, 5-pentane tetracarboxylic acid (HOPTC) and 3, 6-dioxa-1, 2, 4, 5, 7, 8-octane hexacarboxylic acid (DOOHC) which is highly useful in detergent formulations as a sequesterant or builder. This mixture is prepared by reaction of a combination of D, L-tartrate salts with maleate salts catalyzed by calcium ions.
The production of builders or sequesterants for the detergent industry usually involves large volumes of materials. Also, the reaction of organic materials generally provides by-products unwanted or undesired and cost is incurred for their removal. The unwanted by-products often become waste products requiring disposal thereby presenting environmental issues. It is therefore desired to have processes for manufacture which reduce or eliminate by-product disposal requirements and associated costs, particularly in large scale production such as is encountered in the production of builders or sequesterants for use in detergent formulations.
SUMMARY OF THE INVENTION
In accordance with this invention, there is provided a process for preparing HOPTC and DOOHC by the reaction of the salts of maleic acid and a tartaric acid (solids content) said reaction catalyzed by calcium ions and conducted under alkaline conditions wherein unwanted fumarate by-product is reduced. Such reduction is achieved by concentrating the reaction mixture to a solids content of above 60%, by weight, prior to initiation of the reaction. More preferably, the reaction mixture is concentrated by removal of water to a range of from about 62% to about 70% and more particularly to about 62% to about 65% solids.
While the process of this invention achieves the objective of reduced by-product formation in the ranges of solids content as noted above, it is most desired to operate the process of this invention in the preferred range 65% solids content or below because calcium tartrate has been found to precipitate in smaller crystals at higher solids content concentration. While small crystals are not less pure, processing steps such as filtration, etc. become more difficult with smaller crystals.
Various embodiments of this invention may be employed to achieve the concentration of the reaction mixture which has been found to provide advantageous reduction of by-product. In one embodiment concentration of the reaction mixture is provided by holding the reaction mixture for a period of time at moderate temperature while sweeping the reactor with an inert gas such as air to remove water. In another embodiment, the reaction mixture is heated to an elevated temperature such as the reaction temperature or even boiling prior to adding the required amount of base to initiate a reaction thereby removing water at a more rapid rate. It is preferred to subject the reaction mixture to reduced pressure to achieve efficient concentration of the reaction mixture prior to adding the required amount of base to initiate the reaction.
Because there are provided various recycle systems whereby unreacted starting materials are recovered and reused in subsequent reactions process efficiency is maintained even at high reactor solids concentration.
DETAILED DESCRIPTION OF THE INVENTION
Calcium catalyzed reactions for the production of ether carboxylates are known. A typical example of such a process is disclosed in U.S. Pat. No. 4,663,071 to Bush et al and such patent is hereby incorporated by reference.
The U.S. Patent discloses a process for preparing a mixture of HOPTC and DOOHC referred to above. In such process the mixture is obtained by the reaction of maleic acid and tartaric acid salts. This disclosure is a typical example of the reaction of maleic acid with tartaric acid said reaction being catalyzed by calcium ions and conducted in alkaline medium. Such reactions are known in the art as Michael condensation reactions. It is typical of the Michael condensation reactions to provide the most effective equilibrium state for the production of the desired compound or mixture by control of the reactant ratio.
It has been found that D, L-tartaric acid salts possess different solubility characteristics than do either the D- or L- isomers such that the D, L- isomer conveniently precipitate from solution at a pH in the range of from about 7 to about 9.5 while the calcium salts of HOPTC and DOOHC remain in solution and can be purified for use as a builder combination in detergent formulations.
The recovery of unreacted maleate salts from calcium catalyzed reactions of maleic acid salts with salt of tartrate salts in alkaline medium is conveniently achieved by acidifying the reaction product so as to reduce the pH to within the range of about 4 to below about 6.
A particular advantage of the process of this invention, whereby unreacted maleate salt is recovered, is the ability to regulate the reactant ratios more freely since convenient recovery and recycle is possible. Loss of unreacted maleate salt is insignificant and its recovery economical, particularly when maleic acid is employed to reduce the pH of the reaction product of the condensation reaction.
In accordance with one embodiment of this invention the unreacted D, L-tartrate and maleate starting materials are removed by precipitation from the reaction mass prior to the removal of calcium from the system. Specifically, calcium D, L-tartrate and mono sodium maleate are precipitated from the reaction mixture by adjustment of the pH of the reaction solution in two steps. The precipitate of calcium D, L-tartrate and mono sodium maleate is then returned to a subsequent condensation synthesis reaction. It has been found that the small amounts of by-products such as malate and fumarate and residual amounts of HOPTC and DOOHC trapped in the precipitate are not deleterious to the use of this recycled precipitate in subsequent condensation synthesis reaction.
FORMATION OF HOPTC/DOOHC MIXTURES
The first step is the synthesis of HOPTC/DOOHC mixtures by the reaction in aqueous medium of maleate and D, L-tartrate reactants comprising both monovalent cation and calcium salts of maleic acid and D, L-tartaric acid. As noted above, the total amount of maleate plus D, L-tartrate reactants in the aqueous reaction mixture will generally range from about 20% to about 70% by weight of the mixture, more preferably from about 55% to about 65% by weight. Calcium maleate is provided by first reacting maleic acid with calcium hydroxide or calcium carbonate the later preferably provided at least in part by recycle from earlier reactions. The D, L-tartrate is typically provided by epoxidation of maleic acid (from maleic anhydride) in the presence of a catalyst and hydrogen peroxide by known means followed by hydrolysis of the epoxide. One portion of the D, L-tartaric acid employed in the synthesis reaction is taken from the neutralized hydroxylation reaction product. Another portion of the needed D, L-tartrate is provided by the recycled calcium D, L-tartrate provided by earlier reactions as will be more fully described below.
The molar ratio of maleic acid to D, L-tartaric acid in the reaction mixture provided from all the sources noted above will generally range from about 0.5:1 to 8:1, more preferably from about 0.8:1 to about 1.2:1. The ratio of reactants will control the ratio of HOPTC/DOOHC in the final product.
As noted above the synthesis reaction takes place in the presence of a catalyst comprising calcium ions. To provide the necessary amount of calcium cation, several sources can be used. Calcium maleate, prepared from recycled calcium carbonate and maleic acid, may provide one calcium ion source. Previously used but unreacted calcium D, L-tartrate recovered in the process of this invention provides another major calcium ion source. Any additional needed calcium ions, usually a very small amount, is typically provided by an additional calcium ion source such as calcium hydroxide added either as a solid or as a slurry. Other water soluble calcium salts can be employed, but calcium hydroxide possesses the additional advantage of supplying needed hydroxide ions. The total amount of calcium ion present provides a total molar ratio of calcium cation to maleate of 1:1. However, the amount of calcium cation can vary greatly and may be such that the ratio of moles of calcium cations to total moles of maleic and D, L-tartaric acids in solution can approach, but be less than 1.
The hydroxide of a monovalent cation is also essentially added to the reaction mixture as a source of alkalinity. This neutralizing agent is usually added in an amount such that the ratio of moles of monovalent cations to total moles of D, L-tartaric acid plus the moles of maleic acid minus the moles of calcium cations ranges from about 2.1:1 to about 3.8:1. More preferably this ratio ranges from about 2.2:1 to about 3.3:1. The monovalent cation-containing neutralizing agent can be any hydroxide which upon addition to water yields monovalent neutralizing cations in solution. Such neutralizing agents include, for example, alkali metal, ammonium or substituted ammonium hydroxide. Sodium hydroxide is highly preferred.
Sufficient neutralizing agent which, in combination with calcium hydroxide, is added to the synthesis reaction mixture to insure that the reaction mixture is over-neutralized. Thus, the reaction mixture in the process of this invention will generally have a pH within the range of from about 8.5 to 13, more preferably from about 10.5 to about 12.5. The aqueous reaction mixture, after the appropriate amounts of reactants, catalysts and neutralizing agent are combined, is maintained at a temperature of from about 20° C. to about 120° C., preferably from about 70° C. to about 95° C. for a period of time sufficient to form a reaction product mixture containing the desired amounts of HOPTC and DOOHC. Reaction times of from about 0.5 to 50 hours, more preferably from about 1 to 4 hours, would generally be suitable for realizing acceptable yields of the 2 components of the desired mixture. Reaction time is highly affected by temperature whereby higher temperature increases the rate of reaction. The mole ratio of reactants in the reaction mixture, that is, tartrate, maleate, calcium and free hydroxide is 1.1/1.0/0.85/0.50 respectively.
At completion of the reaction the mixture is quenched with water to cool it to a temperature in the range of 80° C. Addition of water also improves the handling of the viscous reaction mass.
MONOSODIUM MALEATE AND D, L-TARTRATE PRECIPITATION
The reaction mixture containing mixed salts of HOPTC and DOOHC also contains relatively large amounts of unreacted maleic and tartrate acid salt. These salts are recovered and recycled to provide higher efficiency of utilization of this valuable raw material.
The recovery of these salts is achieved by a two step method of lowering of the pH of the reaction mixture whereby sodium hydrogen maleate or monosodium maleate and calcium tartrate precipitate. In the preferred embodiment the reaction mixture is cooled and diluted with water. An acidic material such as sulfuric acid, or an organic acid such as formic acid is combined with the reaction mixture in sufficient amount to bring the combined synthesis mass and acid to an initial pH in the range of from about 6 to about 9, preferably slightly below 7. Then, with further addition of suitable acid the pH of the reaction mixture is relatively more rapidly acidified further to a pH in the range of from about 4.5 to below 6, preferably to about 4.8 to about 5.2.
Any number of acidic materials can be employed to lower the pH of the reaction mixture. Combinations of acidic materials may also be employed. Typical examples of such acids are sulfuric acid, hydrochloric acid, nitric acid, formic, acetic, propionic, butyric and D, L-tartaric, carbonic, phosphoric, sulfonic, sulfurous, boric, phosphorous, adipic, benzoic, citric, fumaric, glycolic, malic, maleic, malonic, oxalic, succinic, sorbic, nitrilotriacetic, long chain fatty acids, etc.
In the process of this invention, the acid substance may be added to the crude reaction mass. Alternately, the reaction mass may be added to a heel containing the acid substance. In a further process of this invention, the acid substance and the reaction mass may be added concurrently into a mixing vessel. Sufficient water is added to the reaction mass and/or acid material so that the final concentration of desired ether carboxylate in the completed mixture is about 40%.
Sufficient acid is added to reach a preferred pH of near 5.0 and the precipitated reaction mass is cooled to below 50° C., preferably from just above the freezing point of the mixture to about 40° C. most practically to from about 20° C. to about 30° C. to obtain usable filtration rates in large scale production. In a preferred mode, cooling the reaction product from the 80° C. reaction temperature to 65° C. over 30 minutes is followed by slow cooling to from about 30° C. to about 40° C. The suspension is then allowed to rest for about 30 minutes. The slurry is preferably cooled slowly with mild or slow agitation so as to grow particles which can be filtered in an appropriately short time. Other methods of acid addition such as are noted above can also be employed with appropriate adjustment of precipitation conditions.
In the process of this invention wherein HOPTC and DOOHC are produced it has been found that both unreacted starting acids, D, L-tartaric acid and maleic acid can be recovered in their salt form. Also, it has been found that the calcium salt of D, L-tartaric acid precipitates from the reaction mixture at a pH in the range of from about 7 to about 12 and is typically of smaller crystal habit than the maleate salt. However, according to this invention the two acid salts may be precipitated in a two step procedure which produces globular particles including both acid salts.
When a mixed acid solution is employed to precipitate tartrate and maleate in the process of this invention, the acids may be added either sequentially or concurrently. In one mode of operation, the reaction mass at a temperature of about 80° C., is added to a heel of aqueous acid, typically formic acid, and then a solution of maleic acid is added to the partly neutralized reaction mass.
It has been found that when the pH of the reaction mixture is in the above-stated range calcium D, L-tartrate precipitates when such mixture is diluted with water or cooled to a temperature in the range of from about at least above freezing to about 70° C. The reaction mixture is typically diluted with water in amounts up to about 200 percent by weight. Greater dilution may be accomplished but additional amounts of water are not beneficial due to increased solubility or the salts being precipitated and also would probably require removal later. Dilution of the reaction mixture by about 30 to about 80 percent, by weight, is typical and usually both cooling and dilution are employed to provide maximum amount of tartrate precipitation.
In the process of this invention, there is employed, in conjunction with the above-noted stepwise reduction of pH, the use of crystal seeding whereby small particles of calcium tartrate/monosodium maleate recovered from previous production of mixtures of HOPTC and DOOHC are added to the reaction mixture. Thus, when the temperature of the reaction mixture is first reduced to about 80° C. by diluting the reaction mixture as noted above, crystals of calcium tartrate/sodium maleate from a previous batch are introduced into the reaction mixture. Amounts of crystals in the range of up to about 30 percent of the expected weight of the fresh precipitate may be added. When crystals are employed from the previous filter cake there is provided seed crystals of monosodium maleate. These crystals dissolve leaving calcium tartrate. However, the dissolved monosodium tartrate buffers the solution to a pH of about 6. When the pH is reduced in the second step dissolved monosodium maleate begins to precipitate below about 5.8.
Following the addition of crystals, the pH of the reaction mixture is then slowly reduced by combining the reaction mixture with acid to provide a reaction mixture having a pH in the range of about 7 to about 9 without prior seeding as described above. However, with seeding as noted above it is more preferable to reduce the pH of the reaction mixture in the first step of pH reduction to from about 6 to about 7. While lowering the pH of the reaction mixture it is also cooled to a temperature in the range of from above the freezing point of the mixture to about 50° C. It has been surprisingly found that, in the second step of pH reduction when the pH of the reaction mixture is reduced rapidly, or over a brief period of time, for example up to about one minute to about 10 minutes, unexpectedly large agglomerates of the combined salts of calcium tartrate and monosodium maleate are created. Throughout pH reduction, cooling is required to maintain the temperature of the reaction mixture in the desired range of from above freezing to about 35° C. As noted above, the reaction mixture is held for about 30 to about 40 minutes after final pH reduction to allow crystal formation. It is preferred to allow a short rest period between steps whereby the reaction mixture, at a pH above about 6, rests for about 10 minutes before the second step of pH reduction is performed. The larger agglomerates are more easily separated from the reaction mixture.
Removal of the precipitated acid salt may take any form practical and typically is performed by continuously drawing the slurry from the precipitator to a belt or drum filter or centrifuge. Other forms of removal such as decantation, etc. may also be employed. The filtrate contains the ether carboxylate in salt form. In a preferred embodiment the filtrate is transferred to another precipitator for removal of the calcium cations in the form of calcium carbonate.
In the production the HOPTC/DOOHC mixture filter cake is discharged and, in one embodiment, reslurried with water. The slurry is recycled directly or indirectly to the synthesis reactor to supply a portion of the required D, L-tartrate and maleate salts. Preferably the recovered maleate salt and/or D, L-tartrate salt is slurried with water and mixed with calcium maleate for recycle into the synthesis reaction.
CALCIUM CARBONATE PRECIPITATION
After removal of the insoluble acid salt or salts as described above, the filtrate from such operation is recovered and purified for use as detergent builder. In a preferred embodiment, calcium is removed either batchwise or preferably continuously. Typically, the filtrate from the above-mentioned step is pH adjusted with a base, preferably sodium hydroxide, as it is being fed into a calcium carbonate precipitator to bring the pH of the solution into a range of from about 10 to about 12, preferably from about 10 to about 10.5. The pH adjustment may be performed either in the precipitator or in a separate vessel if desired. The pH adjusted material is maintained in the range of from about 75° C. to about 110° C., preferably at about 90° C. to 100° C. Concurrently a solution of a basic carbonate, preferably sodium carbonate, preferably at a concentration of about 25%, is added to the precipitator to provide an overall mole ratio of carbonate to calcium of 1.3:1.
Alternatively, calcium carbonate is removed by increasing the mole ratio of carbonate ion to calcium ion without change in pH.
Although this invention is described with respect to carbonate precipitation using the preferred sodium cation, it is to be understood that other suitable cations may also be employed to obtain precipitation of calcium carbonate. Other cations useful in the process of this invention include potassium, ammonium or organo substituted ammonium. Other salts may be employed to obtain the calcium carbonate precipitate and includes sodium bicarbonate and mixtures of carbonates and bicarbonates.
During the precipitation of calcium carbonate it is preferred that water is continuously removed from the slurry to maintain the concentration of the organic acid salts in the range of from about 30% to about 50% by weight. Filtration of the precipitated calcium carbonate may take any form practical and typically is performed by continuously drawing the slurry from the precipitator to a centrifuge or to a belt or drum filter. The filtrate contains the desired ether carboxylate mostly as the alkaline salt along with minor amounts of raw material and by-products. In the preparation of HOPTC/DOOHC mixtures, the by-products comprise typically less than 20% by weight of the HOPTC and DOOHC present.
The wet cake from the separation is mechanically reslurried with water to form an approximately 50% calcium carbonate slurry for recycle to the synthesis reaction. The recovered carbonate may be added directly to the ether carboxylate synthesis reactor or together with recovered, unreacted tartrate and maleate. Preferably, the recovered calcium carbonate is converted to calcium maleate in a separate vessel before return to the synthesis reaction.
CALCIUM MALEATE FORMATION
Before introduction into the synthesis reaction, the calcium carbonate precipitate obtained from the product as described above is preferably converted to calcium maleate by reaction with maleic acid. Preferably, the maleic acid is prepared in situ. In one embodiment, the maleic acid is prepared by charging molten maleic anhydride to water heated to 65° C. to 75° C. After hydrolysis of the maleic anhydride to maleic acid is complete, the slurry of calcium carbonate solids is added at a rate slow enough to avoid uncontrolled foaming due to the evolution of carbon dioxide. During the addition of calcium carbonate the reaction mass is heated to a temperature in the range of from about 90° C. to about 100° C. and preferably to about 95° C.
In the production of HOPTC and DOOHC it is preferred that calcium D, L-tartrate and monosodium maleate slurry obtained from the tartrate/maleate removal step is added to the calcium maleate while heating to a boil at atmospheric pressure. The mixture is held at boiling for about 15 minutes to ensure conversion of all of the calcium carbonate to the maleate. The mixture is then charged to the synthesis reactor for the preparation of additional HOPTC and DOOHC. During transfer to the synthesis reactor water may be evaporated to reduce volume.
Although the above described process follows a particular scheme, it is obvious that other schemes or flow charts may also be followed. For example, hold tanks, mixing tanks and transfer tanks may be employed which are not described above. Other variations will occur to those knowledgeable in the art.
EXTRACTION
The filtrate obtained from the procedure to remove calcium carbonate is purified by extraction with methanol and water. Such purification in the production of HOPTC and DOOHC mixtures is shown in U.S. Pat. No. 4,633,071 referred to above.
According to such patent the solution obtained after removal of calcium carbonate is thoroughly mixed with methanol. After settling, two layers form because the desired solution of HOPTC and DOOHC is less soluble in methanol than the impurities to be removed. The undesired solution is decanted and stripped of residual methanol. The residue is dissolved in water and extracted again with methanol.
After purification the product is concentrated so as to provide the desirable concentration of ether carboxylate solution for use as detergent builder or sequestrant. The concentrated material may also be dried by any typical means such as by spray drying, etc. to provide granular or particulate material which is the form traditionally employed.
To further illustrate the process of the present invention there is described below nonlimiting preferred embodiments. In the following examples all percentages are by weight unless otherwise noted.
EXAMPLE 1
Into a round bottom flask equipped with a thermometer, addition funnel, condenser and mechanical stirrer there were placed 39.4 g of maleic anhydride and 200 g of water. The mixture was heated to 70° C. to form maleic acid to which was added 50.lg of calcium carbonate. Then wet filter cake, 350 g, from a previous run together with 100 g of water were added to the flask. The wet cake contained the following in weight percent:
______________________________________Disodium meso tartrate 0.321Calcium D,L-tartrate 19.62Disodium Malate 1.27HOPTC 13.24DOOHC 0.7Monosodium Maleate 15.71______________________________________
After addition of wet cake 62.95 g of D, L-tartaric acid and 550 g of disodium tartrate solution obtained by hydrolysis of epoxysuccinate were added to the reaction. This mixture was heated to 90° C. with stirring. Air was swept through the reactor to remove about 760 g of water during a period of 70 minutes after the reaction mass reached 90° C. Then 127.9 g of sodium hydroxide, 50% solution, was added to the mixture. Heating at 90° C. was continued for another 90 minutes. The reaction mixture was quenched with 126 g of water to reduce the organic solids content from 65% to 54% thereby cooling the reaction mass from 90° C. to about 80° C. The resulting mixture, a clear solution, was then divided into 2 parts with Portion A containing 566 g and Portion B containing 280 g.
Into this portion of the reaction mixture 40 g of filter cake from a previous reaction containing both calcium tartrate and sodium hydrogen maleate together with 160 g of water were added and the reaction mass held at 60° C. After holding for 10 minutes at that temperature formic acid was added over 20 minutes to lower the pH to 5.9. After reducing the pH the reaction mixture was cooled to 35° C. over 30 minutes. The reaction mixture was then held at 35° C. for an additional 30 minutes. A sample was taken for a filtration rate test (A-1). Then a 40% maleic acid solution was added to adjust the pH to 4.85 over a period of about 5 minutes and the system again held at 35° C. for an additional 30 minutes. Another sample was taken (A-2).
B
In this portion of the reaction mixture there were added 15 g of calcium tartrate filter cake as described above in Part A together with 80 g of water. The diluted reaction mixture was then cooled to 35° C. Then formic acid was added over a period of 20 minutes to adjust the pH to 6. The reaction mixture at the lower pH value was held at 35° C. for 45 minutes and a sample taken for a filtration rate test (B-1). A 40% maleic acid solution was added to adjust the pH to 4.8 with relatively rapid addition and the system held at 35° C. for an additional 30 minutes. Another sample was taken for a filtration rate test (B-2). The results of these tests are presented below in Table I. As shown in Table 1, the filtration rates of both samples in Part B are much lower than the samples in Part A. This is believed to be due to the addition of greater amounts of crystal seed material from the previous filter cake in Part A. The filtration rate reported in Table I below was measured at a cake thickness of 12.7 mm.
TABLE I______________________________________Sample A-1 A-2 B-1 B-2______________________________________pH during filtration 5.9 4.85 6.0 4.8Filtration rate 4237 11,407 1263 3259liters/hr/meter.sup.2______________________________________
The filtrates were analyzed to determine their components. The results of the analyses are shown in Table II below. The results indicate that the maleate salt is mostly removed from the system at the lower pH even though maleic acid is employed to acidify the reaction mixture.
TABLE II______________________________________Analyses A-1 A-2 B-1 B-2______________________________________Disodium tartrate 2.2 1.9 2.0 1.6Disodium malate 0.3 0.3 0.0 0.0Disodium maleate 4.6 0.7 4.3 0.5Disodium fumarate 1.1 1.2 1.1 1.0HOPTC 21.0 21.5 20.4 20.0DOOHC 3.2 3.3 3.1 3.3______________________________________
EXAMPLE 2
(Prior Art)
A sodium tartrate solution, 385 g (analysis below), diluted with 115 g. water was charged to a 2 liter 4-necked reactor fitted with a mechanical stirrer, condenser, thermometer and addition funnel. In a separate vessel, maleic anhydride, 92.5 g, was mixed with 200 g. of water and heated to 60° C. to form maleic acid. Then 47 g. of calcium carbonate was added to form calcium maleate. This mixture was then added to the reactor containing the sodium tartrate solution. Calcium tartrate filter cake from a previous reaction, 275 g. (analysis below) was then charged to the reactor. 50% sodium hydroxide, 173 g, and D, L-tartaric acid, 49.5 g, were also added to the reactor. The analyses of these materials are given below in Table III.
TABLE III______________________________________ SODIUM CALCIUM FINALCOMPONENT TARTRATE TARTRATE REACTION(WEIGHT %) SOLUTION FILTER CAKE CHARGE______________________________________Tartrate 29.6 42.1 23.9Malate 0.9 0.4 0.4Maleate 7.3 2.7 15.2Fumarate 0.5 0.7 0.3HOPTC -- 11.1 2.5DOOHC -- 1.1 0.2______________________________________
The mole ratio of reactants at the start of the reaction was tartrate/maleate/calcium/hydroxide=1.3/1.0/0.9/1.0.
The reaction mixture was stirred at 120 rpm and heated at 90°±3° C. for three hours while sweeping air across the reaction to remove water from the system. [Final total solids concentration was 60-65%.] At the end of the reaction, 185 g. of water was added to quench the reaction. Then 45 g of 88% formic acid and 60 g water was added and the reaction mixture allowed to cool to room temperature. The final pH after the addition of formic acid was 5.2. After filtration to remove the crystallized calcium tartrate and sodium hydrogen maleate, the filtrate was analyzed and the results shown below in Table IV.
TABLE IV______________________________________Component Weight %______________________________________disodium tartrate 1.8disodium malate 0.6disodium maleate 0.4disodium fumarate 2.0HOPTC 28.0DOOHC 5.7______________________________________ Total diacids, 4.8% or 14.2% of HOPTC + DOHC Fumarate, 2.0% or 5.9% of HOPTC + DOOHC
This example shows the use of a "standard" procedure for the synthesis of HOPTC+DOOHC that employs recycle of a previously produced filter cake of calcium tartrate and sodium hydrogen maleate.
EXAMPLE 3
The procedure of Example 1 was repeated except that after all the charges were added the reaction mixture was held at 78°∓3° C. for 1.5 hours while removing the excess water by sweeping with air. When the reaction mixture had reacted 60-65% solids level it was heated to 85° C. and held for an additional hour. The reaction was treated as in Example 1. Final pH was 5.0. The filtrate was analyzed as shown below in Table V.
TABLE V______________________________________Component Weight %______________________________________disodium tartrate 1.3disodium malate 0.4disodium maleate 0.4disodium fumarate 1.0HOPTC 24.1DOOHC 5.1______________________________________ Total diacids, 3.1% or 10.6% of HOPTC + DOOHC Fumarate, 1.0% or 3.4% of HOPTC + DOOHC
This example shows that a significant reduction of fumarate content is achieved by concentrating the reaction mixture at a lower temperature prior to heating to the desired reaction temperature.
EXAMPLE 4
This example demonstrates the disadvantage of cooling the reaction mixture before reducing the pH by combining the mixture with acid. A reaction mixture obtained in accordance with the procedure of Example 1 was obtained and divided into four equal portions of 180 g, then each was quenched with 40 g of water. A heel comprising 10 g of formic acid, 88%, and 40 g of water was prepared for each portion.
One portion of the reaction mixture at 52° C. was added to the acid heel thereby lowering the pH of the mixture to about 6.9 while cooling continued over a period of about 32 minutes. Cooling was then continued until the reaction mixture and the combined heel reached about 34° C. The maleic acid mixture, 40%, was then added over a period of about 5 minutes with continued cooling to maintain the reaction mixture at about 34° C. and lowering the pH to 5.0. Globular precipitate formed and the mixture was then filtered to recover the precipitate.
B
The reaction mixture was cooled to 43° C. before being added to the heel. The combined heel and reaction mixture was further cooled to a temperature of about 30° C. during combination which produced a pH of about 7.1 after holding at the noted temperature and pH for about 10 minutes. Maleic acid was then added to the solution over a period of 6 minutes lowering the pH to 5.0. The resulting mixture was then filtered to recover the precipitate.
The filtration rate of each precipitate was measured during filtration and the results appear in Table III below.
TABLE VI______________________________________ Filtration Rate - liters/hr/M.sup.2Cake Thickness - mm A B______________________________________ 9.5 2770.3 1751.812.7 2077.7 1495.115.8 1670.7 1197.7______________________________________
The data in Table III above indicates that combining the reaction mixture with the acid heel at higher temperature improves the filtration rates.
EXAMPLE 5
A reaction mixture obtained in accordance with the procedure of Example 1, 360 g, was quenched with 80 g of water and cooled to about 80° C. An acid heel was prepared by combining 23 g of 88% formic acid and 80 g of water. Into this heel was charged the quenched reaction mixture; however, the pH was lowered, with cooling to about 35° C. as it was combined with the acid heel in the one step whereby the pH of the combination reached about 6.3. Maleic acid, 40%, was added over a period of one hour resulting in a final pH of 5.0. Cooling was continued for an additional one hour and 40 minutes to obtain a final temperature of 32° C. The precipitate was recovered by filtration and the filtration rates at the varying filter cake thicknesses are reported below.
TABLE VII______________________________________Cake Thickness - mm Filtration Rate - liters/hr/M.sup.2______________________________________ 9.5 1222.212.7 93715.8 774______________________________________
By comparing the data presented in Tables II and IV the improvement in product by means of reduced by-product formation in accordance with this invention is clearly shown.
There has been described a novel process of general application for the production of ether carboxylates. While the process has been described with reference to specific compounds no intention is made by such reference to limit the scope of this invention unless expressly stated. Various modifications may be made in the materials and sequence of process steps as well as process combinations which are adapted to suit the various reactants and products without departing from this invention.
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There is disclosed an improved process for preparing 1-hydroxy-3-oxa-1,2,4,5-pentane tetracarboxylic acid and 3,6-dioxa-1,2,4,5,7,8-octane hexacarboxylic acid wherein the reaction mixture has a solids concentration of above about 60%, by weight whereby the amount of by-product fumarate is reduced.
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CLAIM TO PRIORITY
[0001] The present invention claims priority to U.S. Provisional Application No. 60/551,096, filed Mar. 8, 2004, entitled, “METHODS AND APPARATUS FOR ENHANCED RETENTION OF PROSTHETIC IMPLANTS,” and U.S. Provisional Application No. 60/551,080, filed Mar. 8, 2004, entitled, “METHODS AND APPARATUS FOR PIVOTABLE GUIDE SURFACES FOR ARTHROPLASTY,” and U.S. Provisional Application No. 60/551,078, filed Mar. 8, 2004, entitled, “METHODS AND APPARATUS FOR MINIMALLY INVASIVE RESECTION,” and U.S. Provisional Application No. 60/551,631, filed Mar. 8, 2004, entitled, “METHODS AND APPARATUS FOR CONFORMABLE PROSTHETIC IMPLANTS,” and U.S. Provisional Application No. 60/551,307, filed Mar. 8, 2004, entitled, “METHODS AND APPARATUS FOR IMPROVED CUTTING TOOLS FOR RESECTION,” and U.S. Provisional Application No. 60/551,262, filed Mar. 8, 2004, entitled, “METHODS AND APPARATUS FOR IMPROVED DRILLING AND MILLING TOOLS FOR RESECTION,” and U.S. Provisional Application No. 60/551,160, filed Mar. 8, 2004, entitled, “METHODS AND APPARATUS FOR IMPROVED PROFILE BASED RESECTION,” and U.S. patent application Ser. No. 11/036,584, filed Jan. 14, 2005, entitled, “METHODS AND APPARATUS FOR PINPLASTY BONE RESECTION,” which claims priority to U.S. Provisional Application No. 60/536,320, filed Jan. 14, 2004, and U.S. patent application Ser. No. 11/049,634, filed Feb. 3, 2005, entitled, “METHODS AND APPARATUS FOR WIREPLASTY BONE RESECTION,” which claims priority to U.S. Provisional Application No. 60/540,992, filed Feb. 2, 2004, entitled, “METHODS AND APPARATUS FOR WIREPLASTY BONE RESECTION,” the entire disclosures of which are hereby fully incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention generally relates to methods and apparatus for prosthetic implant devices. More particularly, the present invention relates to prosthetic implants for joints that include structure permitting the enhanced retention of the prosthetic implants.
[0004] 2. Background Art
[0005] The replacement or augmentation of joints with artificial or prosthetic implants is well known in the field of orthopedics. Total knee arthroplasty (TKA) procedures involving the replacement of the knee joint are a good example. U.S. Publ. Appl. 2003/0028196A1 and the PFC RP Knee Replacement manual provide a good background for the techniques and devices used as part of these TKA procedures.
[0006] Most typically, a prosthetic implant is provided either with a long post or peg that is seated in a hole drilled into the longitudinal axis of the bone, such as for a tibial implant. In some cases, the peg is provided with a longitudinal fin running anterior-to-posterior that mates with a corresponding channel cut into the bone, such as for a femoral implant. U.S. Publ. Appl. 2003/0100953A1 describes a knee implant that has a pair of shaped pegs for the tibial implant and a longitudinal fin for the femoral implant that includes a peg with external recess features to assist in the fixation of the femoral implant. In one embodiment of the knee implant procedures described in U.S. Publ. Appl. 2003/0028916A1, a TKA femoral implant is described which utilizes a medio-laterally oriented protruding slot on the upper surface of the implant to interface with the femoral surface instead of a peg. The purpose and arrangement of this sideways oriented feature of this femoral implant is to permit the implant to be slid into place from a minimally invasive incision in either the lateral or medial side, as compared to the conventional approach where the major incisions for the TKA procedure are made primarily on the anterior (front) side of the knee.
[0007] It would be desirable to provide for an orthopedic prosthetic implant that could be implanted more consistently and effectively, yet be adaptable for implantation by minimally invasive procedures.
SUMMARY OF THE INVENTION
[0008] The present invention is a prosthetic implant that utilizes lateral retaining structures as part of the interior surface of the implant, instead of pegs and longitudinal fins. The lateral retaining structures serve to more effectively secure and retain the implant while reducing the overall size and mass of the implant, decreasing bone volume lost during the procedure and facilitating minimally invasive surgical techniques. In one embodiment, the prosthetic implant is provided with one or more T-shaped members extending from the inner surface of the implant, with the cross-member of the T-shaped member forming the laterally retaining structure. In this embodiment, the T-shaped members preferably mate with a correspondingly shaped channel formed in the bone and are inserted into that channel at one or more oversize locations along the channel. In another embodiment, the prosthetic implant is provided with one or more grommet features on the inner surface of the implant that are laterally secured with a force fitted cross pin inserted through an aperture formed by the grommet feature. In this embodiment, the apertures of the grommet features are preferably commonly aligned with the holes used to secure the cutting guides. Alternatively, the injection of flowable materials such as bone cement or polymethymethacrylate could be injected or placed so as to ‘form’ a cross pin type retention feature.
[0009] The present invention provides for embodiments of prosthetic implant designs facilitating intraoperative and postoperative efficacy and ease of use. The present invention utilizes a number of embodiments of prosthetic implants, or prosthetic implant features to facilitate clinical efficacy of arthroplasty procedures. The overriding objects of the embodiments are to facilitate short and long terms fixation of the implant with respect to the bone, enable bone preservation to facilitate ease and efficacy of revision, and/or to take advantage of the natural physiological phenomenon determining bone growth response to load stimuli.
[0010] It should be clear that applications of the present invention is not limited to Total Knee Arthroplasty or the other specific applications cited herein, but are rather universally applicable to any form of surgical intervention where the resection of bone is required. These possible applications include, but are not limited to Unicondylar Knee Replacement, Hip Arthroplasty, Ankle Arthroplasty, Spinal Fusion, Osteotomy Procedures (such as High Tibial Osteotomy), ACL or PCL reconstruction, and many others. In essence, any application where an expense, accuracy, precision, soft tissue protection or preservation, minimal incision size or exposure are required or desired for a bone resection and/or prosthetic implantation is a potential application for this technology. In addition, many of the embodiments shown have unique applicability to minimally invasive surgical (MIS) procedures and/or for use in conjunction with Surgical Navigation, Image Guided Surgery, or Computer Aided Surgery systems.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Other important objects and features of the invention will be apparent from the following detailed description of the invention taken in connection with the accompanying drawings in which:
[0012] FIGS. 32-34 , 99 - 115 and 120 - 129 show various depictions of embodiments and methods in accordance with alternate embodiments of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0013] It should be noted that, in many of the figures, the cut surface created by the cutting tool are shown as having already been completed for the sake of clarity. Similarly, the bones may be shown as being transparent or translucent for the sake of clarity. The guides/pins, cutting tool, bones, and other items disclosed are may be similarly represented for the sake of clarity or brevity.
[0014] FIGS. 99 through 112 generally represent prosthesis and prosthesis fixation feature embodiments of the present invention.
[0015] FIGS. 99 through 102 show representations of a tongue in groove fixation feature applied to a Unicondylar femoral component enabling anterior insertion of one tongue element into a ‘t-slot’ style groove formed in bone and a progressively increasing press fit obtained by forcing the implant posteriorly, as is represented in comparing FIGS. 99 and 100 . The t-slot feature, or groove, formed in the femur is easily formed by, in one embodiment, providing a trial component possessing a contoured groove and slot for guiding a t-slot cutter along its length. Such a contour groove would be responsible for controlling the depth of the t-slot in the bone with respect to the cut surface to which the implant fixation surface is attached, while the slot in the trial would dictate the mediolateral location of the t-slot style groove. It is preferable to include an aperture in the slot and/or contour groove in the trial component to allow for insertion and plunging of the wider T cutting surfaces prior to sweeping.
[0016] Alternatively, FIGS. 103 through 112 represent combinations of finned and/or crosspinned implants. It should be noted that the AP Fin Profile of the fin may be linear as shown in FIG. 106 (in other words, the fin may be may be planar), or it could be slightly tapered to achieve an interference fit with the walls of the groove as the implant fixation surfaces are forced into contact with the cut surfaces to which they are mated (see FIGS. 107 through 109 ), or in could be curved as looked at from the viewpoint of FIG. 106 to further provide stability of fixation (this curve could be a single curve or spline or sinusoidal curve, in one embodiment of the present invention allowing for a multiaxial interference fit between the fin and bone to facilitate fixation and avoid deleterious levels of postoperative micromotion). Interestingly, the fixation aperture created to fix a cutting guide to the bone could be utilized to cross pin a flange or fin of a femoral prosthesis. It should be noted that although the embodiment shown is a Unicondylar femoral prosthesis, this concept could be applied to tibial, femoral, or patellofemoral prostheses in any application, or in other joint, trauma, spine, or oncology procedures, as is generally represented in FIGS. 120 through 127 .
[0017] In FIGS. 105 through 112 , a tapered pin is used to engage the cross pin hole in the fin of the prosthesis. The tapered pin may be utilized to facilitate a resulting press fit between the pin and the fixation surfaces of the implant and/or ease of introducing the pin into the hole in the fin. The pin could be of any known material, but resorbable materials are especially interesting as they are ‘consumed’ by the body leaving minimal hardware within the body after a fairly predictable amount of time has passed. PLA/PGA compositions, Tricalcium Phosphate, allograft and autograft bone, bone substitutes, and the aforementioned slurry type compositions may serve well. Alternatively, bone cement or other liquid or semi-liquid material may be injected into the portals/apertures to achieve intimate interdigitation, and the crosspins optionally inserted thereafter, but prior to complete hardening or curing. Alternatively, the crosspin(s) could be hollow with radially extending holes allowing the pins to be inserted and then have bone cement injected into them and up under the implant. Alternatively, the cross pin could be threaded to engage threads in the fin, or to engage the bone (both for short term stability and to facilitate removal) or both. These embodiments hold significant promise in both providing for intraoperatively stable for cemented or cementless fixation as well as facilitating long-term biological ingrowth. It should be noted that the use of multiple holes, pins, and apertures in the prosthesis could be used and that the holes in the bone need not be fixation holes to which guides are attached. Also it should be noted the condylar sections, and patellofemoral sections of the implant could be wholely separate, modularly joined, be composed of a dual condylar prosthesis and separate patellofemoral prosthesis, or any combination of the above. Although the bone/implant interface shown is curved in two planes, these concepts apply to implants with 3 planar curved geometry (where the cutting path and cutting profiles of the resected surface geometry and therefore the fixation surface geometry do not remain in two planes through the entirety of the cutting path, or where the cutting path is contained within multiple or single curved surfaces), entirely planar geometries, or anything in between.
[0018] FIGS. 107 through 112 demonstrate another embodiment of the present invention allowing for benefits well above and beyond those of the prior art. This will be referred to herein as a BMO Prosthesis or BMO Cortical type implant (Biomechanical Optimization Prosthesis). This embodiment has several applications. For instance, if the resected surfaces will to vary significantly from the fixation surface geometries, as may be seen in unguided kinematic resection, it may be advantageous to implement fixation surface geometries that can conform to variation in resection geometry. Most implant materials in joint replacement are thought of as being rigid, and that their rigidity is a desirable characteristic for achieving stable fixation. In the case of surface replacement, that is not necessarily the case. Anecdotally, picture a bar of aluminum 2 inches square and 5 inches long—now picture trying to manually bend it. At these dimensions, aluminum is rigid; however, it is obvious that aluminum foil is not so rigid. The point to this is that very thin (less than 3 mm thick, probably closer to a range of 1.5 to 0.01 mm thick) sections of many metals, including implant grade metals and alloys including cobalt chrome, titanium, zirconium, and liquid metal™, can be processed into very thin forms capable of conforming to variations in the resected surface and yet still have bearing surfaces that are highly polished and provide significant contact area, where desirable, for bearing against the bearing or articular surfaces of the opposing implant. The construct or prosthesis resulting from applying the present invention to a femoral component in Unicondylar knee replacement, for example, may start out being a 1″ wide be 3″ long strip of 1.5 mm thick material curved in a manner to generally look like the curved cutting path and curved cutting profile of a natural, healthy femur. A process such as Tecotex from Viasys Healthcare of Wilmington, Mass. is used to remove material from the strip down to a nominal thickness of perhaps 0.1 mm thick while leaving multiple protruding ‘hooks’ (almost like the hook and eye concept of Velcro) emerging from the thin fixation surface to engage the bone. One or more fins can be attached or be made a continuous part of this construct as shown in FIG. 107 . During insertion, the anterior most cross pin could lock that portion of the prosthesis in place, then the prosthesis could be wrapped around the remaining, more posteriorly resected surfaces and the posterior cross pin inserted (see FIG. 111 ). Alternatively, the fins can be located about the periphery of the articular surfaces of the condyle in the form of tabs and the cross pins or screws or tapered dowels, etc. known in the art inserted through holes in the tabs and into bone to fix the cortical implant. The combination of fins and tabs may also be useful. In using the tabs, it is critical to keep all features of the implanted device ultralow profile to avoid irritating the surrounding soft tissues (perhaps creating recesses in the bone underlying the tabs would be desirable to allow for a form of countersinking of the tabs and/or the pins or screws or other fixation devices).
[0019] Another embodiment of the present invention would be to apply the aforementioned principals to tibial implant design and fixation methodologies. It should be obvious to one of ordinary skill in the art that the crosspin and/or tongue and groove configurations would provide for outstanding stability of tibial component fixation to living bone whether for conventional finned tibial components or the AP or ML fin embodiments of the present invention. FIGS. 32 through 34 represent, very generally, some of the basic primary cut surface geometries to which such implants may be attached (although the fin accommodating cuts are not shown). In regards to conventional state of the art tibial component designs, the implementation of the crosspin embodiments of the present invention will provide for attaining sufficiently robust cementless fixation of implant to bone that the currently substandard results of pressfit tibial components may be significantly improved upon.
[0020] The flexibility of the implant in accordance with the present invention allows the implant to conform to the resection surface and the stability of the crosspin fixation would assist in reducing interfacial micromotion known to inhibit bone ingrowth and fixation (this concept could be used with PMMA, but it is also desirable to avoid the tissue necrosis and bone preservation for revision issues associated with the use of bone cement if the patients health/comorbidities/indications allow). This kind of implant has some very interesting clinical benefits beyond simple bone preservation. Given how well this kind of conformable implant imparts load to underlying bone, thus avoiding stress shielding, it is possible not only to promote healthy bone ingrowth into and around the interfacial features, but the bearing contact and strains/stresses imparted to the bone could motivate the bone to change its shape (and therefore the shape of the conformable implant also changes over time because of the flexibility) to ideally conform to the tibial component bearing surface such that bearing stresses are carried through the broadest desirable contact area just like modeling/remodeling in a healthy unmodified joint).
[0021] FIGS. 113 through 115 are an embodiment of the present invention that may prove to be a very usefully alternative to conventional rectilinear based referencing techniques. In essence, conventional alignment techniques, once having established appropriate flexion extension angulation and varus valgus angulation of desired implant location, reference the anterior cortex, distal most femoral condylar surface, and posterior most condylar surface (indicated in FIG. 114 by stars) to dictate the anterior posterior location, proximal distal location (otherwise known as distal resection depth), and appropriate implant size in determining the ‘perfect’ location and orientation for the appropriately sized implant (mediolateral location is normally ‘eyeballed’ by comparison of some visual reference of the mediolateral border surrounding the distal cut surface and some form of visual guide reference). These conventional techniques fail to directly reference the distinctly different anatomic bone features which dictate the performance of distinctly separate, but functionally interrelated, kinematic phenomena, and they also attempt to reference curvilinear articular surfaces by way of rectilinear approximations. The embodiment of the present invention is an alternative alignment technique with an object to overcome the errors inherent in prior art. As shown in FIG. 115 , the femur possesses two distinct kinematic features and functions that lend themselves to physical referencing; the patellofemoral articular surface and the tibiofemoral articular surfaces, both of which are curved, more specifically these surfaces represent logarithmic curves that may be effectively approximated by arcs. The one codependency between the two articular functions, and therefore any geometric approximation made of them in referencing, is that they must allow for smooth kinematically appropriate articulation of the patella as it passes from its articulation with the trochlear groove (shown in blue in FIG. 115 ) to its articulation with intercondylar surfaces between the femoral condyles (shown in red in FIG. 115 ). Thus, knowing that three points define an arc and may be used to approximate a curve or sections of a curve, what is proposed is to use a referencing device which contacts at least one femoral condyle at three points to determine both an approximation of arc radius and centerpoint location, while independently or simultaneously referencing the trochlear groove at three points to determine both an approximation of arc radius and centerpoint location. The referencing system would further need to provide for the need of the articular surfaces of the trochlear articular surfaces to smoothly transition to those of the intercondylar surfaces. Armed with this information, a surgeon may most appropriately determine appropriate implant location and orientation.
[0022] This embodiment of the present invention is especially useful in determining the proper location, orientation, and implant size for the modular tricompartment components shown in FIGS. 120 through 124 , the non-modular implants shown in FIGS. 125 through 127 , and standard implants where the appropriate size, location, and orientation would be determined by that which best mimics existing articular bone surfaces thus resulting in optimal postoperative kinematic function. FIG. 123 represents one method of fixing the patellofemoral implant with respect to the condylar implant(s) so as to maintain smooth transitional articulation. It should be noted that this crosspin method of interconnecting the separate components could be augmented by tongue and groove interlocking between the medial side of the condylar component shown and the lateral side of the patellofemoral component shown. What is critical is that the transition between the patellofemoral component and the condylar component surfaces responsible for patellofemoral articulation are and remain tangent at at least one point. FIGS. 128 and 129 represent an alignment guide that could be easily modified to accomplish the aforementioned 3 point referencing by addition or inclusion of dedicated or modular referencing means. Alternatively, surgical navigation methods could be implemented in registering these articular surfaces and determining the resulting idealized implant location(s) and orientation(s) as reflected by the geometry and/or kinematics of the joint.
[0023] The complete disclosures of the patents, patent applications and publications cited herein are incorporated by reference in their entirety as if each were individually incorporated. Various modifications and alterations to this invention will become apparent to those skilled in the art without departing from the scope and spirit of this invention. It should be understood that this invention is not intended to be unduly limited by the illustrative embodiments and examples set forth herein and that such examples and embodiments are presented by way of example only with the scope of the invention intended to be limited only by the claims set forth herein.
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A prosthetic implant utilizes lateral retaining structures as part of the interior surface of the implant to more effectively secure and retain the implant while reducing the overall size and mass of the implant. In one embodiment, the prosthetic implant is provided with one or more T-shaped members extending from the inner surface of the implant, with the cross-member of the T-shaped member forming the laterally retaining structure that mate with a correspondingly shaped channel formed in the bone and are inserted into that channel at one or more oversize locations along the channel. In another embodiment, the prosthetic implant is provided with one or more retentions apertures in a projection structure extending inwardly from the inner surface of the implant that are laterally secured with a force fitted cross pin inserted through the retention aperture.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a process for preparing organosilanes by hydrosilylation in the presence of an iridium compound as catalyst and free diene as cocatalyst.
2. Background Art
Substituted alkylsilanes are of tremendous economic importance in many fields. They are used, for example, as adhesion promoters and as crosslinkers.
The platinum- or rhodium-catalyzed hydrosilylation of unsaturated compounds has been widely studied in the past. The product yields are often very low, being only 20-45%, which is attributable to considerable secondary reactions.
Iridium catalysts containing diene ligands are, according to U.S. Pat. No. 4,658,050, used in the hydrosilylation of allyl compounds by means of alkoxy-substituted silanes. JP-A-07126271 describes the hydrosilylation of allyl halides using chlorodimethylsilane in the presence of iridium catalysts containing diene ligands. Disadvantages of these processes are either moderate yields, an uneconomically high catalyst concentration and/or a very short catalyst life.
SUMMARY OF THE INVENTION
It is an object of the invention to develop a catalyst system which has a long life, which ensures high product yields and purities when using very small amounts of catalyst, and which further allows both continuous and batchwise operation.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The invention provides a process for preparing a silane of the formula I
R 6 R 5 CH—R 4 CH—SiR 1 R 2 R 3 (I),
which comprises reacting a silane of the formula II
HSiR 1 R 2 R 3 (II),
with an alkene of the formula III
R 6 R 5 CH═CHR 4 (III),
in the presence of an iridium compound of the formula IV as catalyst
[(diene)IrCl] 2 (IV),
and free diene as cocatalyst, where
R 1 , R 2 , and R 3 are each independently a monovalent Si—C-bonded, unsubstituted or halogen-substituted C 1 -C 18 -hydrocarbon radical, a chlorine atom or a C 1 -C 18 -alkoxy radical,
R 4 , R 5 , and R 6 are each independently a hydrogen atom, a monovalent C 1 -C 18 -hydrocarbon radical which may be unsubstituted or may optionally bear F, Cl, OR, NR′ 2 , CN or NCO atoms/groups as substituents, a chlorine atom, a fluorine atom or a C 1 -C 18 -alkoxy radical, where in each case 2 radicals R 4 , R 5 , R 6 together with the carbon atoms to which they are bound may form a cyclic radical,
R is a hydrogen atom or a monovalent C 1 -C 18 -hydrocarbon radical and diene is a C 4 -C 50 -hydrocarbon compound which may be unsubstituted or bear F, Cl, OR, NR′ 2 , CN or NCO atoms/groups as substituents and has at least two ethylenic C═C double bonds.
In this process, the target products of the formula I are typically obtained in yields of from 95% to 98% when using very small amounts of catalyst. Depending on the field of application, work-up by distillation can therefore often be dispensed with.
C 1 -C 18 -hydrocarbon radicals R 1 , R 2 , R 3 are preferably alkyl, alkenyl, cycloalkyl or aryl radicals. R 1 , R 2 , R 3 preferably have not more than 10, in particular not more than 6, carbon atoms. R 1 , R 2 , R 3 are preferably linear or branched C 1 -C 6 -alkyl radicals or C 1 -C 6 -alkoxy radicals. Preferred halogen substituents are fluorine and chlorine. Particularly preferred radicals R 1 , R 2 , R 3 are methyl, ethyl, methoxy, ethoxy, chlorine, phenyl and vinyl.
Hydrocarbon radicals R 4 , R 5 , R 6 are preferably alkyl, alkenyl, cycloalkyl or aryl radicals. It is preferred that not more than one of R 4 , R 5 , R 6 is an alkoxy radical. R 5 , R 6 preferably have not more than 10, in particular not more than 6, carbon atoms. R 5 , R 6 are preferably linear or branched C 1 -C 6 -alkyl radicals or C 1 -C 6 -alkoxy radicals. Particularly preferred radicals R 5 , R 6 are hydrogen, methyl, ethyl, chlorine and phenyl.
The hydrocarbon radical R 4 preferably has not more than 6, in particular not more than 2, carbon atoms. Particularly preferred radicals R 4 are hydrogen, methyl, and ethyl.
The hydrocarbon radical R preferably has not more than 6, in particular not more than 2, carbon atoms.
The hydrocarbon compounds used as diene may comprise not only molecular units containing the ethylenic C═C double bonds, but may also comprise alkyl, cycloalkyl or aryl units. The dienes preferably have from 6 to 12 carbon atoms. Preference is given to monocyclic or bicyclic dienes. Preferred examples of dienes are butadiene, 1,3-hexadiene, 1,4-hexadiene, 1,5-hexadiene, isoprene, 1,3-cyclohexadiene, 1,3-cyclooctadiene, 1,4-cyclooctadiene, 1,5-cyclooctadiene and norbornadiene.
The diene in the catalyst of the formula IV and the free diene serving as cocatalyst can be identical or different. Preference is given to the two dienes being identical.
In a particularly preferred case, the catalyst of the formula IV used is [(cycloocta-1c,5c-diene)IrCl] 2 and the cocatalyst used is 1,5-cyclooctadiene.
The silane component of the formula II is preferably used in an excess of from 0.01 to 100 mol % of II, more preferably from 0.1 to 10 mol %, based on the alkene of the formula III. The iridium compound of the formula IV is preferably present in a concentration of from 5 to 250 ppm, in particular from 10 to 50 ppm, based on all components present in the reaction mixture. The diene as cocatalyst is preferably added in a concentration of from 50 to 2500 ppm, in particular from 50 to 1000 ppm, based on all components present in the reaction mixture.
The process can be carried out in the presence or absence of aprotic solvents. If aprotic solvents are used, solvents or solvent mixtures having a boiling point or boiling range up to 120° C. at 0.1 MPa are preferred. Examples of such solvents are ethers such as dioxane, tetrahydrofuran, diethyl ether, diisopropyl ether, and diethylene glycol dimethyl ether; chlorinated hydrocarbons such as dichloromethane, trichloromethane, tetrachloromethane, 1,2-dichloroethane, and trichloroethylene; hydrocarbons such as pentane, n-hexane, hexane isomer mixtures, heptane, octane, naphtha, petroleum ether, benzene, toluene, and xylene(s); ketones such as acetone, methyl ethyl ketone, diisopropyl ketone, and methyl isobutyl ketone (MIBK); esters such as ethyl acetate, butyl acetate, propyl propionate, ethyl butyrate, and ethyl isobutyrate; carbon disulfide; and nitrobenzene, or mixtures of these solvents. This list is exemplary and not limiting.
The target product of the formula I can also be used as an aprotic solvent in the process. This process variant is preferred. For example, the reaction components of the formula II together with the iridium catalyst of the formula IV and optionally the diene are placed in a reaction vessel and the reaction component of the formula III, optionally in admixture with the diene, is introduced while stirring. In another variant, the target product of the formula I together with the catalyst of the formula IV and optionally diene are placed in a reaction vessel and a mixture of components II, III and optionally diene is introduced. The reaction time to be employed is preferably from 10 to 2000 minutes. The reaction is preferably carried out at a temperature of from 0 to 300° C., in particular from 20 to 200° C. The use of superatmospheric pressure may also be useful; the pressure is preferably up to 100 bar.
The addition of the diene also allows a plurality of reactions to be carried out without further addition of catalyst. Preference is given to adding further amounts of diene as cocatalyst as the reaction proceeds, in particular, in a continuous manner.
The meanings of all the symbols in the formulae above are in each case independent of one another. In the following examples, all concentrations and percentages are by weight, all pressures are 0.10 MPa (abs.) and all temperatures are 20° C. unless indicated otherwise.
EXAMPLE 1
(Embodiment I)
19.2 g (0.25 mol) of allyl chloride, 0.1 g (9.2·10 −4 mol) of 1,5-cyclooctadiene and 3.0 mg (4.5·10 −6 mol) of di-μ-chlorobis[(cycloocta-1c,5c-diene)iridium(I)] were placed in a 100 ml three-neck flask provided with a low-temperature condenser, internal thermometer and dropping funnel. At a bath temperature of 37° C., a mixture of 23.7 g (0.25 mol) of chlorodimethylsilane and 0.1 g (9.2·10 −4 mol) of 1,5-cyclooctadiene was introduced over a period of 1.5 hours in such a way that the internal temperature did not exceed 45° C. For the post-reaction, the mixture was maintained at a bath temperature of 45° C. for an additional one hour. Work-up by distillation gave 40.8 g of chloro(3-chloro-propyl)dimethylsilane, corresponding to a yield of 95% based on the silane.
EXAMPLE 2
(Reusability of a Catalyst Charge)
The procedure was analogous to that of Example 1. In place of the work-up by distillation, 19.2 g (0.25 mol) of allyl chloride and 0.1 g (9.2·10 −4 mol) of 1,5-cyclooctadiene were added to the mixture and a mixture of 23.7 g (0.25 mol) of chlorodimethylsilane and 0 . 1 g (9.2·10 −4 mol) of 1,5-cyclooctadiene was again introduced. The reaction was carried out in a manner analogous to Example 1. The total yield after distillation was 76.2 g (89%).
EXAMPLE 3
(Demonstration of the Catalytic Activity of the Distillation Bottoms)
19.2 g (0.25 mol) of allyl chloride and 0.1 g (9.2·10 −4 mol) of 1,5-cyclooctadiene were added to the distillation residue from Example 2 and a mixture of 23.7 g (0.25 mol) of chlorodimethylsilane and 0.1 g (9.2·10 −4 mol) of 1,5-cyclooctadiene was again introduced. The reaction was carried out in a manner analogous to Example 1. The yield after distillation was 37.0 g (87%).
EXAMPLE 4
(Embodiment II)
The procedure was analogous to that of Example 1. In addition, 10.0 g (0.06 mol) of chloro(3-chloropropyl)dimethylsilane were placed in the reaction flask as solvent. Distillation gave 48.8 g of product. After subtraction of the 10.0 g used, the yield is 38.8 g, corresponding to a percentage yield of 91%.
EXAMPLE 5
(Embodiment III)
Using a batch size as in Example 2, chloro(3-chloropropyl)dimethylsilane, catalyst and 1,5-cyclooctadiene were placed in the reaction flask and a mixture of allyl chloride, chlorodimethylsilane and 1,5-cyclooctadiene was added dropwise. Distillation gave 50.1 g of product. After subtraction of the 10.0 g of desired product employed as solvent, the yield is 40.1 g, corresponding to a percentage yield of 94%.
EXAMPLE 6
(Comparative Example Using a Platinum Catalyst)
19.2 g (0.25 mol) of allyl chloride and 21.0 mg (3.1·10 −5 mol, 125 ppm) of dichlorodicyclopentadieneplatinum(II) were placed in a 100 ml three-neck flask provided with a low-temperature condenser, internal thermometer and dropping funnel. At a bath temperature of 37° C., 23.7 g (0.25 mol) of chlorodimethylsilane were introduced. The mixture was allowed to react further at 50° C. for another 3 hours. Work-up by distillation gave only 18.1 g (42%) of chloro(3-chloropropyl)dimethylsilane.
EXAMPLE 7
(Comparative Example Without Addition of the Cocatalyst)
The procedure of Example 1 was used, but without addition of 1,5-cyclooctadiene. Even after a reaction time of 24 hours, no measurable reaction was found (NMR).
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The invention relates to a process for preparing a silane of the formula I
R 6 R 5 CH—R 4 CH—SiR 1 R 2 R 3 (I),
which comprises reacting a silane of the formula II
HSiR 1 R 2 R 3 (II),
with an alkene of the formula III
R 6 R 5 CH═CHR 4 (III),
in the presence of an iridium compound of the formula IV as catalyst
[(diene)IrCl] 2 (IV),
and free diene as cocatalyst, where R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R and diene are as defined in claim 1.
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FIELD OF THE INVENTION
This invention relates to a method of improving the properties of cellulosic paper. In another aspect it relates to paper which exhibits improvements in properties such as wet and dry tensile strength, wet and dry burst strength, wet and dry tear resistance, fold resistance, and the like.
BACKGROUND OF THE INVENTION
Cellulosic pulp based products comprise one of the largest and most important markets for commercial materials. The technology involved with paper and cardboard is well developed and comprises many additives to yield a multitude of property improvements. Property improvements desired include wet and dry tensile strength, wet and dry burst strength, wet and dry tear resistance, fold resistance, oil resistance, solvent/stain resistance, etc. Additives to paper are characterized by the position of addition relative to the paper-making process. The addition of additives to the slurried pulp (paper stock) prior to sheet formation is commonly referred to as wet-end addition. The addition to paper after formation and at least partial drying is referred to as dry-end addition.
Various additives are applied to the pulp slurry prior to sheet formation. These include retention aids to retain fines and fillers (e.g. alum, poly(ethyleneimine), cationic starches), drainage aids (e.g. poly(ethyleneimine), defoamers, additives which control pitch or stickies (e.g. microfibers, adsorbent fillers). Additionally wet strength additives such as cationic polyacrylamides and poly(amide amine/epichlorohydrin) are added in the wet end to improve wet strength as well as dry strength. Starch, guar gums, and polyacrylamides are also added to yield dry strength improvements. Urea-formaldehyde and melamine-formaldehyde resins are employed as low cost wet strength additives; however, due to residual formaldehyde these resins have fallen out of favor and are being replaced.
Sizing agents are added to impart hydrophobic character to the hydrophilic cellulosic fibers. These agents are used for liquid containers (e.g. milk, juice), paper cups, and surfaces printed by aqueous inks (to prevent spreading of the ink). Rosin sizes derived from pine trees were initially used as well as wax emulsions. More recently, cellulose-reactive sizes have been employed. These include alkyl ketene dimer (AKD) and alkenyl succinic anhydride (ASA). AKD is discussed b Marton (TAPPI J., p. 139, Nov. 1990) and Zhou (Paper Technology, p. 19, Jul. 1991).
The additives noted above can also be added to the dry-end of the papermaking process. These additives can be added various ways. One of the common methods is referred to as the size press addition. This generally involves nip rolls in which a water solution of the additive(s) is flooded and allowed to penetrate the paper. Other methods of addition include spray application and tub sizing.
Starch is the most commonly employed additive in size press addition. Carboxy methyl cellulose, polyvinyl alcohol, cellulose reactive sizes, wax emulsions are also commonly employed for size press addition. Poly(vinyl acetate) emulsions, as well as poly(ethylene-vinyl chloride), poly(styrenebutadiene) and polyacrylic emulsions are commonly added at the dry-end of the paper making process as a surface size or paper coating additive. The add-on levels (dry additive on dry pulp) at the dry end can be low (0.05-4 wt%) as sizing additives (either surface or internal sizing) or high (4-20+wt% dry-on-dry) in the case of saturation sizing. The properties desired are variable, however, include wet and dry tensile strength, fold resistance, wet and dry burst strength, porosity closing, wet and dry tear strength, printability, surface characteristics, oil resistance, etc.
Specific versions of poly(vinyl alcohol) offer many of these improvements, specifically dry strength, wet strength, fold resistance, burst strength and oil resistance. Poly(vinyl alcohol) is generally added in dry-end application as it has poor substansivity to cellulosic products. Highly crystalline poly(vinyl alcohol) generally yields the best wet strength properties as it is insoluble in cold water. Crosslinking additives such as glyoxal can be added to yield specific property improvements. (See Polyvinyl Alcohol Developments, C.A. Finch, ed. (1992) pp 270-273; 591-595).
The use of functional polymers of various types has been known for many years as a means to improve papermaking processes and paper properties. Several of these resins for improving wet strength of the paper have involved products derived from epihalohydrin. U.S. 3,535,288 Lipowski, et al. (1970) discloses an improved cationic polyamide-epichlorohydrin thermosetting resin as useful in the manufacture of wet-strength paper. U.S. 3,715,336 Nowak, et al. (1973) describes vinyl alcohol/vinylamine copolymers as useful flocculants in clarification of aqueous suspensions and, when combined with epichlorohydrin, as useful wet-strength resins for paper. The copolymers are prepared by hydrolysis of vinylcarbamate/vinyl acetate copolymers made by copolymerization of vinyl acetate and vinyl isocyanate followed by the conversion of the isocyanate functionality to carbamate functionality with an alkanol. Additionally, Canadian Pat. No. 1,155,597 (1983) discloses wet-strength resins used in papermaking, including polymers of diallylamine reacted with epihalohydrin and a vinyl polymer reacted with epihalohydrin wherein the vinyl polymer is formed from a monomer prepared by reacting an aromatic vinyl alkyl halide with an amine, such as dimethylamine.
Functional polymers derived from amides have also been used to improve paper processes. U.S. 3,597,314 Lanbe, et al. (1971) discloses that drainage of cellulose fiber suspensions can be enhanced by the addition of a fully or partially hydrolyzed polymer of N-vinyl-N-methyl carboxylic acid amide. U.S. 4,311,805 Moritani, et al. (1982) discloses paper-strength additives made by copolymerizing a vinyl ester, such as vinyl acetate, and an acrylamide derivative, followed by hydrolysis of the ester groups to hydroxy groups. The presence of the remaining cationic groups enables the polymer to be adsorbed on pulp fibers. Utilities for the polymers as sizing agents, drainage aids, size retention aids and as binders for pigments are disclosed but not demonstrated. U.S. 4,421,602 Brunnmueller, et al. (1983) describes partially hydrolyzed homopolymers of N-vinylformamide as useful as retention agents, drainage aids and flocculants in papermaking. European patent application 0,331,047 (1989) notes the utility of high molecular weight poly(vinylamine) as a wet-end additive in papermaking for improved dry strength and as a filler retention aid. U.S. Pat. No. 4,614,762 discusses a water soluble product of polyethyleneimine reacted with formaldehyde and poly(vinyl alcohol). The product is noted to be useful as an improved drainage and retention aid in papermaking.
More recently, vinylamide copolymers have been disclosed as useful in papermaking to improve the properties of the product. U.S. Pat. No. 4,774,285 Pfohl, et al. (1988) describes amine functional polymers formed by copolymerizing vinyl acetate or vinyl propionate with N-vinylformamide (NVF) followed by 30-100% hydrolysis to eliminate formyl groups and the acetyl or propionyl groups. The copolymer contains 10-95 mole, NVF and 5-90 mole% vinyl acetate or vinyl propionate. The hydrolyzed copolymers are useful in papermaking to increase dry strength and wet strength when added in an amount of 0.1 to 5 wt% based on dry fiber. The polymer can be added to the pulp or applied to the formed sheet. The two polymers used to show dry and wet strength improvements are said to contain 40% and 60% N-vinylformamide before hydrolysis. Lower levels of amine functionality in poly(vinyl alcohol) are not demonstrated to be effective.
U.S. Pat. Nos. 4,880,497 and 4,978,427 discuss the use of amine functional polymers for use in improving the dry and wet strength of paper. These amine functional polymers are based on copolymers comprising 10 to 95 mole % N-vinyl formamide which are hydrolyzed to yield amine functionality. The copolymer also contains an ethylenically unsaturated monomer including vinyl esters (such as vinyl acetate), alkyl vinyl ethers, N-vinyl pyrrolidone, and the esters, nitrites and amides of acrylic acid or methacrylic acid. The problems of copolymerization to yield uniform copolymers of vinyl acetate/N-vinyl formamide above 10 mole % NVF are not noted and the examples shown in these patents do not represent random copolymers but most probably polymer mixtures of various compositions between poly(vinyl acetate) and poly(N-vinyl formamide) (before hydrolysis).
U.S. Pat. No. 4,808,683 Itagaki, et al. (1989) describes a vinylamine copolymer such as a copolymer of N-vinylformamide and N-substituted-acrylamide, which is said to be useful as a paper strengthening agent and European patent application 0,251,182 (1988) describes a vinylamine copolymer formed by hydrolysis of a copolymer of N-vinylformamide and acrylonitrile or methacrylonitrile. The product is said to be useful in papermaking as a drainage aid, retention aid and strength increasing agent. Examples presented to demonstrate the paper strengthening effect of the polymer used a pulp slurry containing cationic starch, alkyl ketene dimer as a sizing agent and a filler retention improving agent, but there is no indication of any cooperative effect between the polymer and the sizing agent.
On the other hand, certain combinations of additives have been found to be useful as paper additives. U.S. Pat. No. 4,772,359, Linhart, et al. (1988) discloses utility of homopolymers or copolymers of N-vinylamides, such as N-vinylformamide (NVF), in combination with phenol resin as a drainage aid in pulp slurries for production of paper. In this service unhydrolyzed poly NVF is said to function cooperatively with the phenol resin, while a partially hydrolyzed poly NVF does not (see Example 6). European patent application No. 0,337,310 (1989) describes improving moist compressive strength of paper products using the combination of hydrolyzed poly(vinyl-acetate-vinylamide) and an anionic polymer such as carboxymethyl cellulose or anionic starch. The hydrolyzed polymer can contain 1-50 mole% vinylamine units and examples are given of polymers having amine functionality of 3-30%.
G. G. Spence in Encyclopedia of Polymer Science and Technology, 2nd Ed., Wiley-Interscience, Vol. 10, p. 761-786, N.Y., 1987, provides a comprehensive survey of paper additives describing the functions and benefits of various additives and resins used in the manufacture of paper. Wet-end additives are discussed at length. Resins containing amine groups that provide cationic functionality and have low molecular weights (10 3 to 10 5 ) e.g., poly(ethyleneimine), are used to aid retention of fines in the paper. Acrylamide-based water soluble polymers are used as additives to enhance dry strength of paper while a variety of resins, such as melamineformaldehyde resins, improve wet strength. Poly(ethyleneimine), however, is said not to be commercially significant as a wet-strength resin. Sizing agents are used to reduce penetration of liquids, especially water, into paper which, being cellulosic, is very hydrophilic. Sizing agents disclosed are rosin-based agents, synthetic cellulose-reactive materials such as alkyl ketene dimer (AKD), alkenyl succinic anhydrides (ASA) and anhydrides of long-chain fatty acids, such as stearic anhydride, wax emulsions and fluorochemical sizes. Cationic retention aids, such as alum, cationic starch or aminopolyamide-epichlorohydrin wet-strength resin, are used to retain the size particles in the sheet.
SUMMARY OF THE INVENTION
We have found that the addition of crosslinking additives along with polyvinyl alcohol/vinylamine copolymers (PVOH/VAm) at the dry end step of a papermaking process results in unexpected improvements in the properties of the resultant paper products, especially at low levels of copolymer addition; i.e., from about 0.1 to 8 wt% dry-on-dry (dry additive/dry pulp). The properties which are enhanced by this process include wet and dry tensile strength, burst strength and fold resistance. An option of this invention involves the addition of the copolymer at the wet end with the crosslinking additive added at the dry end.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graph of wet tensile strength as a function of wt% (dry-on-dry) copolymer add-on for Airvol 325 (a polyvinyl alcohol avail commercially from Air Products and Chemicals, Inc.); Airvol 325 with a crosslinking agent; PVOH/VAM copolymer; and PVOH/VAM copolymer with a crosslinking agent.
FIG. 2 is a graph of dry tensile strength as a function of wt% (dry-on-dry) copolymer add-on for the same compositions as in the graph of FIG. 1.
FIG. 3 is a graph of wet burst strength as a function of wt% (dry-on-dry) copolymer add-on for the same compositions as in the graph of FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
We have found that the addition of crosslinking additives along with polyvinyl alcohol/vinylamine copolymers offer significant improvements in property achievements in dry end addition to cellulosic based materials (e.g. paper and paper-type products). The addition of the crosslinking agents allows for significant property improvements with low levels of PVOH/VAm addition. For example, wet tensile strength and wet burst strength show significant improvements at copolymer addition levels from about 0.1 to 8 wt% (dry-on-dry) when crosslinking additives are employed. PVOH/VAm crosslinked versions also show improvements in dry tensile strength, dry burst strength and fold resistance at these levels of copolymer addition. Synergistic results are also observed when cellulosic reactive sizes are added. An option to dry end addition of both copolymer and crosslinking additive is to add the copolymer at the wet end of the papermaking operation with the crosslinker added at the dry end. When both the copolymer and the crosslinker are added at the wet end no advantage is seen with crosslinker addition.
The vinyl alcohol/vinylamine copolymers used in this process contain between 0.5 and 25 mole% vinylamine units, with from 2 to 12 moles% being preferred, and can be produced by the polymerization of vinyl acetate/N-vinylamides (e.g. N-vinyl formamide, N-vinyl acetamide) followed by the hydrolysis of both the vinyl acetate (to vinyl alcohol) and the vinyl amide (to vinylamine). Hydrolysis does not have to be complete, and suitable PVOH/VAm copolymers may contain up to 60% of unhydrolyzed amide units and up to 25% unhydrolyzed acetate units.
The preparation of poly(vinyl acetate) and the hydrolysis to poly(vinyl alcohol) are well known to those skilled in the art and are discussed in detail in the books "Poly(vinyl alcohol): Properties and Applications," ed. by C. A. Finch, John Wiley & Sons, N.Y., 1973 and "Poly(vinyl alcohol) Fibers," ed. by I. Sakurada, Marcel Dekker, Inc., N.Y. 1985. A recent review of poly(vinyl alcohol) was given by F.L. Marten in the Encyclopedia of Polymer Science and Engineering, 2nd ed., Vol. 17, p. 167, John Wiley & Sons, N.Y., 1989.
Poly(vinyl acetate) can be prepared by methods well known in the art including emulsion, suspension, solution or bulk polymerization techniques. Rodriguez in "Principles of Polymer Systems," p. 98-101, 403, 405 (McGraw-Hill, N.Y., 1970) describes bulk and solution polymerization procedures and the specifics of emulsion polymerization. Amine functional poly(vinyl alcohol) can be prepared by copolymerization of N-vinyl amides (e.g. Nvinyl formamide or N-vinyl acetamide) or allyl amine with vinyl acetate using methods employed for poly(vinyl acetate) polymerizations. Above 10 mole % incorporation of the N-vinylamides leads to product variations unless delayed feed of the N-vinyl amides is employed. With allyl amine, above 10 mole % leads to lower molecular weight than desired, thus the desired vinyl alcohol copolymers would contain up to 10 mole % allyl amine.
When preparing poly(vinyl acetate) by suspension polymerization, the monomer is typically dispersed in water containing a suspending agent such as poly(vinyl alcohol) wherein an initiator such as peroxide is added thereto. The unreacted monomer is devolatilized after polymerization is completed and the polymer is filtered and dried. This procedure for preparation of poly(vinyl acetate) can also be employed for the vinyl acetate copolymers (as precursors for amine functional poly(vinyl alcohol)) of this invention.
Poly(vinyl acetate) can also be prepared via solution polymerization wherein the vinyl acetate is dissolved in a solvent in the presence of an initiator for polymerization. Following completion of the polymerization, the polymer is recovered by coagulation and the solvent is removed by devolatilization. The vinyl acetate copolymers (as precursors for amine functional poly(vinyl alcohol)) can be prepared via this procedure.
Bulk polymerization is not normally practiced in the commercial manufacture of poly(vinyl acetate) or vinyl acetate copolymers. However, bulk polymerization could be utilized if proper provisions are made for heat of polymerization removal.
Crosslinking agents which are added along with the copolymer include glyoxal, glutaraldehyde, phenol-formaldehyde resins, urea-formaldehyde, melamine-formaldehyde, epoxy resins, maleic anhydride copolymers, diisocyanates, dicarboxylic acids and other crosslinking agents commonly employed for poly(vinyl alcohol). The crosslinking agents can be added to the copolymer prior to addition to the dry end pulp, or may be added separately to the dry end pulp either before or after the addition of the copolymer. Typically, the crosslinking agent is added in a concentration from about 2 to 50 wt% based upon copolymer, with from 4 to 30 wt% being preferred.
The experimental data presented in the examples below demonstrate that PVOH/VAm copolymers with crosslinking additives offer major property improvements (wet and dry tensile strength, burst strength, and fold resistance) over control paper and PVOH modified paper (including PVOH with crosslinking additives) at low levels of add-on with dry end addition. These examples are presented to better illustrate and are not meant to be limiting.
Experimental
The following examples are presented to better illustrate the present invention and are not meant to be limiting.
Sample Preparation
Test samples were prepared as follows using Whatman #4 filter paper all from the same lot (roll). The filter paper was cut into 3"wide pieces which were then weighed. 8% aqueous solutions of the various polymers were prepared in accordance with standard synthesis techniques. Solution solids were adjusted to achieve the desired coat weights. Crosslinking material was added to the solution for those particular tests. The desired solution was poured into a pan and a filter paper sample was then submerged in the pan with solution for several seconds until thoroughly saturated. The polymer saturated sample was then put through an Atlas Padder to remove excess polymer solution. The sized sample was then placed in an oven at 150° C. for 5 minutes. After cooling and equilibrating, the dried filter paper sample was then reweighed and the final coat weight calculated. If the coat weight (wt % copolymer addition) was off from the desired weight, the sample was discarded and the polymer solution solids were adjusted to achieve the desired coat weight. Four samples of the desired weight were prepared, equilibrated in a constant temperature humidity (CTH) chamber (50% R.H. and 24° C. temp.) cabinet overnight and tested.
Gurley Porosity
TAPPI T-460 - Air Resistance of Paper
This test was used to measure the air resistance of paper by measuring the time it takes a given volume of air to pass through a sample.
The test sample, preconditioned at 24° C. and 50% relative humidity, was clamped into the testing apparatus and subjected to air pressure by the weight of the inner cylinder, when released. The amount of time it takes 100 ml of air to pass through the test sample is measured to the nearest 0.1 second.
MIT FOLD
TAPPI T-511 - Folding Endurance of Paper
This test was used to determine the folding endurance of paper. The basic apparatus consists of a stationary clamping jaw, a spring assembly to apply the desired load and an oscillating clamping jaw to induce folding of the sample.
The test sample, pre-conditioned at 24° C. and 50% relative humidity was placed in the test apparatus. The spring assembly was set to 0.25 kilograms. Power was turned on and the oscillating jaw folded the sample 175±25 cycles/min. An automatic counter recorded the number of double fold cycles to sample breakage.
Mullen Burst
TAPPI T-403 - Bursting Strength of Paper
This test was used to measure the bursting strength, both wet and dry, of the paper samples.
The test sample, preconditioned at 24° C. and 50% relative humidity was clamped into the testing apparatus. Power was turned on and air pressure was continually applied to expand a rubber diaphragm until the paper sample burst. The dry burst strength was reported in psi. For wet burst strength, the preconditioned test sample was soaked for 5 seconds in water. The sample was then immediately clamped into the testing apparatus and the burst strength measured in psi.
% Water Absorption
This test was developed to measure the amount of water absorbed by the test sample.
The test sample, preconditioned at 24° C. and 50% relative humidity, was pre-weighed to the nearest 0.01 gram. The sample was then immersed in a pan of water for 5 seconds and then blotted to remove excess surface water and reweighed. The result was reported as the percent of water weight gained with respect to the original samples dry weight.
Tensile Strength
TAPPI T-494 - Tensile Breaking Properties of Paper and Paperboard (using constant rate of elongation apparatus)
A test similar to TAPPI T-494 was used to measure the force per unit width required to break a sample. The test sample, preconditioned at 24° C. and 50% relative humidity is cut into 1/2 strips. For dry tensiles the strips were clamped into an Instron tensile tester. The gauge length was 4"and crosshead speed was 0.20 in/min. A 20 to 50 pound load range was used depending on the strength of the sample. The dry strips (3-4 samples) were then broken with average dry tensile reported in pounds/inch. For wet tensiles, the 1/2 strips were soaked in tap water for 30 minutes, blotted and immediately clamped into the Instron. Instrument conditions for wet tensiles were the same as dry tensiles except a 10 pound load range was used. Again 3-4 samples were run and the average wet tensile strength reported in pounds/inch.
Example 1
Samples were prepared according to the previously described Sample Preparation section using polyvinyl alcohol/(10% ) vinylamine (PVOH/VAm), a fully hydrolyzed, medium molecular weight, water soluble copolymer from Air Products and Chemicals. Samples were prepared at a coat weight of 8% with and without Glyoxal N-40 from American Hoechst added at 15% dry based on dry polymer. Results showed the PVOH/VAm copolymer with no Glyoxal N-40 addition improved all paper properties tested except Gurley Porosity, when compared to untreated Whatman #4 filter paper. All Gurley porosity values are very low and comparable. When 15% Glyoxal N-40 was added, all wet strength properties improved even much more over the untreated filter paper. The Glyoxal N-40 treated samples also showed large improvements over samples without the Glyoxal N-40, especially in wet strength and tear resistance.
TABLE 1______________________________________ Untreated PVOH/(10%) VAm°HCl Filter 8% Coat Weight Paper No N-40 15% N-40______________________________________Tensile Strength (pli)Dry 10.9 17.7 19.4Wet 0.4 0.7 8.7Mullen Burst (psi)Dry 8 38 32Wet 1 3 24MIT Fold 7 347 5% Water Absorption 159 175 76Gurley Porosity (sec) 2.2 2.1 3.2______________________________________
Example 2
Samples were prepared according to the previously described Sample Preparation section using polyvinyl alcohol/(5%) vinylamine (PVOH/VAm), a fully hydrolyzed, medium molecular weight, water soluble copolymer from Air Products and Chemicals. Samples were prepared at a coat weight of 8%, with and without Glyoxal N-40 from American Hoechst, Glyoxal N-40 added at 15% dry based on dry polymer. Results showed the PVOH/VAm copolymer with no Glyoxal N-40 addition improved all paper properties tested except Gurley Porosity and wet Mullen Burst, when compared to untreated Whatman #4 filter paper. When 15% Glyoxal N-40 was added, all properties improved except MIT fold over the untreated filter paper. The Glyoxal N-40 treated samples also showed large improvements in wet strengths over samples without the Glyoxal N-40.
TABLE 2______________________________________ Untreated PVOH/(5%) VAm°HCl Filter 8% Coat Weight Paper No N-40 15% N-40______________________________________Tensile Strength (pli)Dry 10.9 14.5 20.8Wet 0.4 0.8 8.2Mullen Burst (psi)Dry 8 33 37Wet 1 2 30MIT Fold 7 469 177% Water Absorption 159 148 73Gurley Porosity (sec) 2.2 1.8 3.0______________________________________
Example 3
Samples were prepared according to the previously described Sample Preparation section using polyvinyl alcohol/10% vinylamine (PVOH/VAm), a fully hydrolyzed, medium molecular weight, water soluble copolymer. Samples were prepared at a coat weight of 1.5% dry polymer based on dry paper using 5 and 15% levels (based on dry polymer) of Parez 802 (urea formaldehyde resin from American Cyanamid) for crosslinking. Results showed improvements in wet and dry tensiles, wet and dry Mullen Burst strength and MIT fold resistance over uncrosslinked PVOH/10% VAm and untreated control paper (#4 Whatman filter paper).
TABLE 3______________________________________ No 15% Control Crosslinker 5% Parez 802 Parez 802______________________________________Tensile (pli)Dry 8.9 8.2 10.0 9.7Wet 0.3 0.6 3.6 3.5MullenBurst (psi)Dry 8 14 18 15Wet 1 2 7 6MIT Fold 7 15 23 26% Water 165 139 135 139AbsorptionGurley 1.6 1.9 1.9 1.9Porosity______________________________________
Example 4
Samples were prepared according to the previously described Sample Preparation section using polyvinyl alcohol/10% vinyl amine (PVOH/VAm), a fully hydrolyzed, medium molecular weight, water soluble copolymer. Samples were prepared at a lower coat weight of 1.5% dry polymer based on dry paper using 15% level (based on dry polymer) of Cymel 385 (melamine formaldehyde resin from American Cyanamid) for crosslinking. The resin was catalyzed using 2% Cycat 6060 (toluene sulfonic acid type from American Cyanamid). Results showed improvements in wet and dry tensiles, wet and dry Mullen Burst strength and MIT fold resistance over uncrosslinked PVOH/10% VAm and untreated control paper (#4 Whatman filter paper).
TABLE 4______________________________________ No Control Crosslinker 15% Cymel 385______________________________________Tensile (pli)Dry 8.9 8.2 11.2Wet 0.3 0.6 4.2Mullen Burst (psi)Dry 8 14 22Wet 1 2 9MIT Fold 7 15 28% Water 165 139 143AbsorptionGurley Porosity 1.6 1.9 1.9______________________________________
Example 5
Samples were prepared according to the previously described Sample Preparation section using polyvinyl alcohol/(5%) vinylamine (PVOH/VAm), a fully hydrolyzed, medium molecular weight, water soluble copolymer from Air Products and Chemicals and Airvol 325, a fully hydrolyzed, medium molecular weight, polyvinyl alcohol from Air Products and Chemicals. Samples were prepared at coat weights of 0.5, 1.5, 4 and 8%, with and without Glyoxal N-40 from American Hoechst, Glyoxal N-40 added at 15% based on dry polymer.
The results are illustrated in the graphs of FIGS. 1 through 3 for wet tensile strength, dry tensile strength and wet burst strength respectively. The results of all the tests for these samples are set out in Table 5 below.
TABLE 5__________________________________________________________________________ Con- Airvol Airvol Airvol Airvol PVOH/PVAm PVOH/PVAm PVOH/PVAm PVOH/PVAm trol 325 325 325 325 (5%) (5%) (5%) (5%)__________________________________________________________________________NO GLYOXALCoat Weight (%) 0.0 0.5 1.5 4.0 8.0 0.5 1.5 4.0 8.0Tensiles (pli)Dry 6.8 8.8 10.8 14.8 19.3 9.8 11.6 11.5 19.4Wet 0.2 0.6 1.5 3.5 4.8 1.7 2.0 1.5 0.7Mullen Burst (psi)Dry 8 13 18 25 34 20 17 25 34Wet 1 1 2 6 12 3 3 2 2MIT Fold 7 18 37 60 120 23 21 224 447% Water Absorption 171 148 147 137 135 149 143 162 154Gurley Porosity 0.9 0.9 0.9 1.1 1.4 1.1 1.1 1.0 1.015% GLYOXALCoat Weight (%) 0.5 1.5 4.0 8.0 0.5 1.5 4.0 8.0Tensiles (pli)Dry 10.4 12.2 21.1 23.2 15.1 15.6 16.8 21.2Wet 0.8 1.0 3.2 4.1 5.3 5.9 7.0 4.6Mullen Burst (psi)Dry 16 20 31 37 25 28 27 37Wet 4 7 25 31 15 21 23 34MIT Fold 18 38 90 67 87 94 43 105% Water Absorption 137 133 101 90 111 100 95 55Gurley Porosity 0.9 1.0 1.2 1.6 4.6 2.8 4.9 1.8__________________________________________________________________________
Example 6
An intermediate size paper machine capable of 500 lbs/hour was employed to make an unbleached paper based on unbleached Southern Softwood Pulp (K#˜60) from Champion international. Pulp was added to a pulp chest and mixed with water and added to a beater to reduce the Canadian Freeness to ˜650. The resultant pulp was pumped to another pulp chest where a poly(vinyl alcohol/vinylamine) (HCl) (˜7 mole% VAm•HCl) was added (predissolved in water). The PVOH/VAm•HCl had a 4% solution pH of 2.99 and a 4% solution viscosity of 45.30 cps. The PVOH/VAm•HCl was added at dry-on-dry levels of 0.5 wt% and 0.95 wt% on the pulp. The pulp slurry was fed to the paper machine to yield a basis weight of 50 lbs/3000 ft 2 . The paper width produced was a 48 inch slice with a 42 inch trim. The line rate was 125 ft/min. The dried paper was rolled up after production samples were taken and tested in the machine direction (see Table 6). A control paper without any additives was also produced for comparison. The addition of PVOH/VAm•HCl (wet-end) yielded increased dry and wet tensile strength and wet and dry burst strength.
The unbleached Kraft paper containing either 0.5% or 0.95% PVOH/VAm copolymer, was post-treated with a solution containing glyoxal N-40. The glyoxal was applied at levels of both 20 and 40% active glyoxal based on dry polymer solids. The glyoxal application was accomplished by saturating the Kraft paper sheet in the appropriate solution, processing the wet paper through an Atlas coater and then curing it in an oven at 150° C. for 5 minutes. Then the samples were conditioned overnight in a CTH chamber (23° C. 50% humidity). After conditioning, the samples were tested for dry and wet tensile strength, dry and wet Mullen burst strength and percent water absorption. Also tested for comparison were papers containing the two levels of PVOH/VAm copolymers without glyoxal post-treatment and untreated control paper.
The glyoxal addition (as a dry-end addition) to the wet-end addition of the PVOH/VAm copolymer yielded significant improvements in wet strength.
TABLE 6______________________________________Dry Wet Dry WetTen- Ten- % % Mullen Mullen %sile sile Streng Water Burst Burst Streng(pli) (pli) Retain Absorp (psi) (psi) Retain______________________________________Control 26.3 1.2 5 159 31 2 6UntreatControl 31.1 4.8 15 29 43 17 400.5%PVOH/VAm0.5% 37.9 10.3 27 28 50 22 44PVOH/VAm20%Glyoxal0.5% 37.5 10.6 28 28 51 29 57PVOH/VAm40%GlyoxalControl 36.4 6.5 18 35 42 23 550.95%PVOH/VAm0.95% 32.8 11.9 36 28 45 31 69PVOH/VAm20%Glyoxal0.95% 30.7 12.2 40 29 55 34 62PVOH/VAm40%Glyoxal______________________________________
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An improved papermaking process has been developed to enhance the properties of the resultant paper or paper-type products. The process involves adding a polyvinyl alcohol/vinylamine copolymer along with a crosslinking agent at the dry end step of a conventional papermaking process. Improvements in the properties of the resultant paper products are observed, especially at low levels of copolymer addition.
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FIELD OF THE INVENTION
[0001] This invention relates generally to energy-conversion and, more particularly, to devices such as motors, generators and alternators and the like which provide a mechanical output in response to electrical energy and vice versa.
BACKGROUND OF THE INVENTION
[0002] For purposes of this disclosure, the term electric energy-conversion machine means a machine or device having magnetic field generating components and which converts a non-electrical energy input into an electric energy output and vice versa. The operation of an electric energy-conversion machine, such as a motor, alternator, or generator, relies upon effective coupling of magnetic flux or field developed in the stator poles into the rotor air gap or space and, hence, the rotor. However, in most electric energy-conversion machines, there is considerable fringe or leakage flux which bypasses the rotor space, and, therefore, is not coupled to the rotor since the magnetic flux takes the path of least resistance in the magnetic circuit, or the path of lowest magnetic reluctance. Since the opposing poles in a two pole electric energy-conversion machine are in the shape of circular cylindrical surfaces, to accommodate the cylindrical rotor, the extreme portions of the opposing poles, which are the closest to each other, offer the path of least resistance to the magnetic flux and a significant portion of that flux bridges such portions of the opposing poles and, thereby, bypasses the rotor. This fringe or leakage flux serves no useful purpose and prevents the electric energy-conversion machine from achieving optimum operational or performance characteristics.
[0003] In U.S. Pat. No. 4,942,323, issued on Jul. 17, 1990, an electric motor is disclosed having a stator that uses two electromagnetic elements. The first electromagnetic element includes windings of a conventional design while the second electromagnetic element includes windings that encircle the rotor. While this construction provides a number of performance benefits, the increased weight and manufacturing complexity is unsuitable for certain applications.
SUMMARY OF THE INVENTION
[0004] The shortcomings of the prior art are addressed by the present invention. In accordance with one aspect of the present invention, a motor, generator, alternator or the like uses a stator whose magnetic field generating element encircles the rotor and is disposed above and below the longitudinal axis of the rotor. This magnetic field generating element may be either an electromagnet or a permanent magnet. The resulting structure provides a motor, generator or alternator having significantly reduced weight.
[0005] In accordance with another aspect of the present invention, the use of a stator whose magnet field generating element encircles the rotor above and below its longitudinal axis may be combined with a conventional stator magnetic field generating element. In this combination, at least one of the stator elements that provide a magnetic field is a permanent magnet.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] The present invention will be more fully appreciated from a consideration of the following Detailed Description, which should be read in light of the accompanying drawings in which:
[0007] [0007]FIG. 1 shows a perspective view of a motor having a rotor with a single rotor winding and two commutator segments, and a stator including only two stator windings in accordance with the principle of the invention;
[0008] [0008]FIG. 2 shows a perspective view of a motor having a rotor with multiple rotor windings and commutator segments, and a stator including only two stator windings in accordance with the principle of the invention;
[0009] [0009]FIG. 3 shows a DC motor having a pair permanent magnets in the stator and those components from FIG. 2 in accordance with the principle of invention; and
[0010] [0010]FIG. 4 shows a DC motor according to the principle, in which the stator has only two field windings and two supplemental windings, and the motor has multiple windings with commutator segments.
DETAILED DESCRIPTION
[0011] [0011]FIG. 1 shows a perspective view of exemplary motor assembly 100 having rotor 110 , and a stator including only two stator windings, 120 a and 120 b, which encircle rotor 110 in accordance with the principles of the invention. Rotor 110 comprises armature 111 and rotor, rotor winding 112 , shaft 130 , and commutator 140 , which are well known in the art and are not described herein. It should be noted that there are only two commutator segments because there is only one rotor winding.
[0012] According to the principles of the invention, stator windings 120 a and 120 b, encircle rotor 110 above and below the longitudinal axis of rotor 110 (shown as 150 in FIG. 1) of the rotor. These windings are not wound on conventional stator supports or forms to reduce weight and are disposed parallel to longitudinal axis 150 . Without the restrictions of the supports or the forms, stator windings 120 a and 120 b are disposed side by side and opposite to each other with respect to dash line 160 which is perpendicular to and intersects the axis of the rotor. Stator windings 120 a and 120 b are arranged to avoid shaft 130 , so that the rotary motion of rotor 110 is not obstructed. Stator windings 120 a and 120 b are arranged in such a way that the magnetic fluxes generated by both windings pass through the rotor from the same side, i.e., they are arranged in the same North-South (N-S) orientation. Stator windings 120 a and 120 b are arranged side by side, so that they are as close to the center of the motor as possible. It should be noted that stator windings 120 a and 120 b can be converted into a single winding by electrical coupling therebetween. An advantage for converting into one winding is that the magnet field generated is stronger, and, thus, the resulting electric energy-conversion machine utilizing these components is more efficient.
[0013] As readily appreciated by a person skilled in the art, the structure of motor assembly 100 can also be used to as DC (direct current) or AC (alternating current) generators or AC motors.
[0014] [0014]FIG. 2 shows a perspective view of another exemplary motor assembly 200 in which the stator includes only stator windings 120 a and 120 b. The components that are of the same type as those in FIG. 1 are labeled the same. For example, stator windings 120 a and 120 b are of the same type as those in FIG. 1. They are disposed in the same manner and can be converted into a single winding as in FIG. 1. Motor assembly 200 is essentially the same as motor assembly 100 except the following two differences. First, rotor 210 has six windings, 212 a - 212 e, rather than just one and, thus, armature 211 has six slots for the six rotor windings. Second, commutator 240 have six commutator segments rather than two. Like motor assembly 100 , motor assembly 200 can be used to as DC or AC motors or generators.
[0015] Referring now to FIG. 3, an exemplary DC motor 300 utilizing those components from motor assembly 200 except that stator 370 comprises a pair of permanent magnets, 371 a and 371 b, in addition to stator windings 120 a and 120 b. Stator 370 has an air gap for receiving rotor 210 (see FIG. 2 for the components of rotor assembly 200 ). Rotor 210 is rotatably mounted on stator 370 . The assembly of stator 370 and rotor assembly 200 without stator windings 120 a and 120 b are known in the art and is not described herein. The attachment of stator windings 120 a and 120 b to stator 370 is by two metal straps (not shown) holding the two stator windings and screwed to the sides of the stator, one on the front side and the other on the back side of stator 370 . Other fastening methods can be used as well. For example, stator windings 120 a and 120 b can be glued to stator 370 . As show in FIG. 3, stator windings 120 a and 120 b (shown in solid lines) are located between commutator 240 and the rotor windings. Optionally, stator windings 120 a and 120 b (shown in phantom lines) can be shifted further to the left into the area of commutator 240 . However, the two stator windings must be shaped in a way (such as shown) as to avoid interfering with the rotary motion of commutators 240 . It should be noted that stator windings 120 a and 120 b can be replaced with a pair of magnets encircling rotor 210 above and below longitudinal axis 150 . It should be noted that the magnetic fluxes generated by the stator windings should pass through the motor from the same side as the flux generated by the permanent magnets, so that they do not cancel each other. It should also be noted that the same machine shown in FIG. 3 can be used as a DC generator by converting the rotational mechanical power into DC power output at commutator 240 whose segments are connected to the rotor windings. In a similar manner, the components of motor assembly 100 can be combined with stator 370 to form a DC motor or a DC generator.
[0016] Referring now to FIG. 4, another exemplary DC motor 400 is shown. DC motor 400 comprises the same components as DC motor 300 except that the pair of permanent magnets are replaced by the pair of field windings 471 a and 471 b in stator 470 . The magnet fluxes generated by stator windings 120 a and 120 b, which can be viewed as supplemental stator windings, should pass through the rotor from the same side as the magnet flux generated by field windings 471 a and 471 b. In this illustrative embodiment, field windings 471 a and 471 b are not electrically coupled to stator windings 120 a and 120 b. However, field windings 471 a and 471 b can be electrically coupled to stator winding in any conventional fashion, e.g., in series or in parallel. The same electric energy-conversion machine shown in FIG. 4 can be used as an DC generator for converting the rotational mechanical power from rotor assembly into DC power at commutator 240 whose segments are connected to the rotor windings. The same machine can be used as an AC motor if the input power is AC. It can also be used as AC generator if the input power to field windings 471 a and 471 b is AC.
[0017] It should be noted that a motor or a generator comprises other components such as brushes but those components are known in the art and are not described herein.
[0018] The examples given herein are presented to enable those skilled in the art to more clearly understand and practice the instant invention. The examples should not be considered as limitations upon the scope of the invention, but as merely being illustrative and representative of the use of the invention. Numerous modifications and alternative embodiments of the invention will be apparent to those skilled in the art in view of the foregoing description. Accordingly, this description is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the best mode of carrying out the invention and is not intended to illustrate all possible forms thereof. It is also understood that the words used are words of description, rather than limitation, and that details of the structure may be varied substantially without departing from the spirit of the invention and the exclusive use of all modifications which come within the scope of the appended claims is reserved.
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A design for a motor, alternator, generator, or the like wherein the stator element that provides the magnetic field passing through the rotor completely encircles the rotor above and below its longitudinal axis. This stator element may be a permanent magnet or an electromagnet. This stator design can be combined with a conventional stator element that also provides a magnetic field. In such case, at least one of the magnetic field producing elements of the stator is a permanent magnet.
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BACKGROUND AND BRIEF SUMMARY OF THE INVENTION
This invention relates to land or amphibious vehicles with articulated legs. Prior art vehicles, especially those adapted for moving over rough or uneven terrain have been proposed. Typically these vehicles employ telescopic legs pivotally secured to a body or segmental legs adapted for limited oscillatory movement in one or more fixed planes. These prior art vehicles are generally subject to the problems of both lack of flexibility of movement of the vehicle per se in several directions such as forward, reverse, banking and rotatable movement; and the inability to control the movement of all legs substantially simultaneously. In this latter situation the legs are not all controlled substantially simultaneously such as when moving over rough terrain, the vehicle moves slowly and awkwardly.
My invention is directed to a vehicle with articulated legs and a method of operating the same, which vehicle can travel over rough terrain at high speeds.
My invention broadly comprises a vehicle and a method of operating the same; which vehicle has a plurality of articulated legs. Each of the legs is adapted to move in a plurality of planes. A level sensor is provided to ascertain the plane of the vehicle in reference to the horizontal. The legs and level sensor communicate both with a control module and a power source.
The power source provides the drive for the movement of the legs and the legs in turn control the movement and plane of the vehicle.
The control module includes a computer with associated interface equipment. The computer is programmed particularly for operation of the vehicle. The computer senses commands such as direction and speed of movement, the present position of the legs, the movements which each of the legs must effect to respond to the direction and speed input signal, and lastly transmits the proper communications to the legs whereby the desired movement is effected.
In a preferred embodiment of the invention the legs are pivotally secured to the vehicle at one end and contact the surface at another end. Further the legs are comprised of at least two linkages and the legs are controlled by determining the angular relationship of the linkages in reference to the vertical and the horizontal.
In the preferred embodiment six legs are used; each leg having an upper link and a lower link. The vehicle may move through six basic movements: rotation around a Z-axis, which axis passes vertically through the vehicle; forward or reverse movement along a Y-axis, which axis is perpendicular to the Z-axis; lateral movement along an X-axis which X-axis is perpendicular to both the Y and Z axes; upward and downward movement along the Z-axis; rotary movement about the Y-axis; and rotary movement about the X-axis or any combination thereof.
The legs are moved through an increment or distance delta a (Δa) with a variable height (h) which in combination with the distance traveled (a+Δa) allows control of the legs.
At least three basic angles are defined, from which angles the necessary calculations are made: angle A (∠A), preferably an acute angle, between the longitudinal axes of the upper and lower links, angle B (∠B), preferably an acute angle, between the horizontal plane of the vehicle and the longitudinal axis of the upper link; and angle C (∠C), preferably less than 180°, between the plane of the vehicle and the plane within which both links like.
The means to sense the plane of the vehicle comprises a gimbal-pendulum arrangement wherein the pitch, roll and/or yawl of the vehicle may be sensed. Each leg is controlled by a computer. The computer reads the desired speed and direction from a control stick and a control wheel. Each actual leg position is read by a sensor which reads angular position, and the level position of the vehicle is read by sensors associated with the gimbal-pendulum arrangement. These control signals and position sense signals are read by the computer and the computer controls the leg movements following the preestablished programs in the computer memory.
The machine can move in any direction, such as in a circle, forward, sideways or at any angle, can turn about its center axis (Z), can turn and move in any plane, and can change its level and can bank while turning.
My invention broadly comprises a vehicle adapted for use on land or sea which includes a housing having a longitudinal axis Y, a transverse axis X, and a vertical axis Z, the axes being mutually perpendicular one to the other. A plurality of articulated legs are secured to and extending downwardly from the housing, the legs each comprising an upper link and a lower link. The upper link is joined to the housing and to the lower link. The longitudinal axes of the links intersect and define an angle A. The longitudinal axis of the upper link is adapted for movement in at least two planes through two angles. A first plane parallel to the Y and Z axes and through an angle B, and a second plane parallel to the X and Z axes and through an angle C. The movement in said planes results in a substantially cone-shaped region. The legs are in communication with a drive means and also with a control means. The legs are responsive to the control means and the drive means to move through at least one of the three angles.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a land vehicle with articulated legs embodying my invention;
FIG. 2 is a side schematic illustrating my invention;
FIG. 3 is a front view of FIG. 2;
FIG. 4 is a top view of FIG. 2;
FIG. 5 is a front view of an articulated leg of FIG. 1;
FIG. 6 is a side view of the leg of FIG. 5;
FIG. 7 is a perspective view of the leg of FIG. 5;
FIG. 8a is a perspective illustration of a gimbal-pendulum arrangement;
FIG. 8b is a side view of the control wheel and the control stick;
FIG. 9 is a graphic representation of the angles derived from the articulated leg positions formulated in determining the leg movement formulas;
FIGS. 10a and 10b are schematics of one leg during trace and retrace cycles;
FIGS. 11 through 19 are pictorial representations used to illustrate the operation of the invention; and,
FIG. 20 is a functional block diagram of input-output to the computer.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, a land vehicle with articulated legs is shown generally at 10 and it comprises a body 11 including a platform 12 to which is secured a seat 14, a forward housing 16 through which passes a control wheel (steering wheel) 18. A control stick 20 is secured to the platform 12. Enclosed within the housing 16 is an engine 22, such as a General Motors 4 cylinder 200 horsepower engine.
A computer 200 with associated interface equipment (FIG. 20), a variable delivery oil pump 24 and a gimbal-pendulum arrangement 60 (FIG. 8) are also disposed in the housing 16.
The engine 22 is standard and includes a speed governor to maintain a constant rpm. The oil pump 24 is a constant pressure variable delivery bypass type. When a demand is placed on the pump 24 to maintain constant pressure the load is transferred to the engine 22. Because of the governor the engine will maintain constant speed. This particular concept is well known in the art and need not be described in detail. Further for this same reason the engine components such as coils, fuel supply, ignition, etc. have not been shown in detail.
The variable oil pump 24 is geared to the engine 22. A pump such as an ABEX DENISON Series 2-700 may be used. The pump includes an output hose 25a and an input hose 25b. Hoses such as Parker 34 Series (SAE100R9 Type AT) are suitable. As will be described, eighteen four-way solenoid valves are used, three for each of the six legs. Thus the input and output hoses 25a and 25b branch to include eighteen output conduits 29a through 29r and eighteen input conduits 31a through 31r, two pairs to each of the solenoid valves. For purposes of clarity not all of these lines are shown. Two bladder type accumulators 28a and 28b such as Parker Type MS-28700-4 are placed in the input and output hoses 25a and 25b between the pump 24 and where the hoses 25a and 25b branch to form conduits. The accumulators 28 eliminate or reduce the standing wave ratio (reflection) problem created when solenoid valves are opened and closed at a high rate.
Each pair of input/output conduits 29a-31a, 29b-31b, etc., are hydraulically secured to a solenoid valve. In this embodiment there are eighteen solenoid valves, three for each leg.
For the purposes of clarity only three solenoid valves with associated cylinders will be described in detail. It is to be understood that although only one leg will be described in detail that each leg of the vehicle 10 functions mechanically and hydraulically in the same manner.
There are six legs 40, 42, 44, 46, 48 and 50: legs 40, 44, 46 and 50 at corners of the platform 12; and legs 42 and 48 secured to the platform 12 at the sides thereof, intermediate the legs 40 and 44; and 46 and 50 respectively. One of these legs with its associated cylinders and solenoid valves is shown more clearly in FIGS. 5, 6 and 7. A gimbal-pendulum level sensor 60 is shown schematically in FIG. 1 and in greater detail in FIG. 8. This gimbal-pendulum level sensor 60 is positioned in the center of the vehicle 12, such that when the Z axis of the vehicle (or CT axis, see FIG. 4) passes therethrough.
Each of the total leg assemblies being identical only one will be described in detail namely the leg 40.
Referring to FIG. 5, secured below the platform 12 adjacent the cut-out portion 12a is a hinge 32. A support plate 34 is secured to the hinge 32. As will appear this allows movement of the leg 40 through ∠C.
The leg 40 comprises an upper link 300 and a lower link 302. Relative movement of the links, one to the other, is through ∠A. Movement of the link 300 to the platform is through ∠B. The upper link includes two parallel supports 306 and 308 rotatably pinned at their one or upper ends to the plate 34 and pinned at their other or lower ends to the one or upper end of the lower link 302. At the other or lower end of the lower link 304 is a rectangular shaped foot 310 pinned thereto for movement in two planes.
A plurality of solenoids 312, 314 and 316 are secured to the top surface of the platform 10. Each of the solenoids includes paired lines 312a, 312b; 314a, 314b; and 316a, 316b; and output lines 312b, 314b and 316b are connected respectively to cylinders 318, 320 and 322. The input and output conduits 29 and 31 are connected to the accumulators 28 and thus to pump 24. The solenoids also are electrically responsive to the computer 200.
As shown most clearly in FIGS. 5 and 7, the cylinder 318 which effects the lateral movement (∠C) of the leg 40 is rotatably pinned at one end between the arms of a U-shaped plate 324 which plate is rotatably secured to the underside of the platform 12. The end of the piston rod of the cylinder 318 is secured at its other end to the upper linkage 302. More specifically, the other end is rotatably pinned between the arms of a U-shaped plate 326, which plate is rotatably secured to the support 306 of the link 300. If desired ball and socket joints could be used in place of the U-shaped support plates.
The cylinder 320 in its upper portion has extending pins. Arms 340 are secured to the supports 306 and 308. The pins are rotatably received in the arms 340 securing the cylinder 320 therein. The lower link 302 has extending arms 342. The end of the piston rod of the cylinder 320 is rotatably secured to the arms 342. The cylinder 320 controls the ∠A.
The end of the piston rod of the cylinder 322 is characterized by an extending pin 344 which is rotatably received in the supports 306 and 308. The cylinder 322 is rotatably secured to the plate 34 by an arm 346. Preferably the arm is welded to the cylinder 322 and journaled in the plate 32. The cylinder 322 controls the ∠B.
As shown in FIGS. 5 and 7, cylinders 318, 320 and 322 have associated solenoid valves 312, 314 and 316 with paired lines 312a, 312b, etc., to the cylinders and input conduits and output conduits 29-31, etc. to the main oil pump.
The specific arrangement of cylinders, solenoid valves, lines, conduits, linkages, pins, braces, etc., are illustrative of the preferred embodiment of this invention. Other variations of mechanical and hydraulic configurations will be apparent to those skilled in the art in which one effects the movement of the leg 40 through an ∠C through an ∠B, and through an ∠A, these movements ocurring solely or in any combination thereof. Alternatively all connections between links, the upper link to the platform, the foot to the lower link, and the securing of the pistons to the links and to the vehicle could be achieved through ball and socket joints.
Sensors of the type used for the gimbal-pendulum level sensor measure the angles A, B and C. A sensor 360 measures ∠A, a sensor 362 measures ∠B and a sensor 364 measures ∠C. The sensors are shown schematically in FIG. 5 and may be secured in any suitable manner. Further they are responsive to the computer 200. The sensors, as will be described, may either by optical encoders or potentiometers. The sensors are calibrated and scaled to provide an output signal, such as voltage.
FIG. 2 is a side schematic view of the vehicle 10 illustrating the X, Y and Z axes of the vehicle. FIGS. 3 and 4 are front and top views of FIG. 2 also illustrating the same axes as well as associated angles as will be referred to in the description of the operation of the invention.
The gimbal-pendulum level sensor 60 which is shown generally in FIG. 1, is shown in perspective illustration in FIG. 8a and comprises two depending support plates 382 and 384 secured to the platform and extending downwardly from the bottom surface thereof. A gimbal 386 is journalled to the lower ends of these supports 382 and 384. A sensor 388 such as a rheostat or an optical encoder monitors movement about the X axis and a sensor 390 such as a rheostat or an optical encoder monitors movement about the Y axis. A pendulum 392 extends from the lower portion of the gimbal. Both sensors communicate with the computer 200. A height switch 27 is on the front panel. The switch 27 is a potentiometer which ranges from OFF at 1.2 volts to full at 0.3 volts output. At OFF level platform 12 is 60 inches from ground; at full level platform 12 is 15 inches from ground. It establishes a desired height of the vehicle 10 when level.
The control wheel 18 is connected to a shaft as shown in FIG. 8b. At the end of the shaft there is a wheel position sensing device 19 such as a potentiometer or an optical encoder. When the wheel is moved the sensor is moved by the shaft and its change in position generates a corresponding change in electrical signal. This signal is input into the computer 200. The computer converts this information to the desired turning ratio to complete the control of the leg movement.
The control stick 20 is movably secured to the platform and to a position sensing device 21. This device 21 is a gimbal arrangement identical to the type remote control unit for a hobbyist's airplane. Two sensors for the X and Y axes such as potentiometers or optical encoders are used as with the gimbal 60. When in a neutral position the output to the computer 200 indicates no movement. As will be described in the operation of the invention, when the stick 20 is moved forward to the rear or to the side then of course the optical encoders or rheostat provide signals to the computer 200 indicating the amounts of movement that are required for each leg. The sensors of the preferred embodiment are potentiometers such as Allen Bradley type GAINO5bS hot molded composite potentiometer-linear taper. Optical encoders such as available from Dynamic Research Corporation or other sensors may be used. Each leg has three sensors. For leg 40, FIGS. 5, 6 and 7, the potentiometers are shown schematically. All legs being identical, the remaining legs 42, 44, 46, 48 and 50, each have three sensors for a total of eighteen sensors from the six legs.
The gimbal-pendulum level sensor 60 has two sensors, both potentiometers shown schematically in FIG. 8a. The control wheel 18 has a sensor 18 which is a potentiometer.
The control stick 20 has two sensors; potentiometers to measure changes from level along the X axis and Y axis. The height switch 27 has a potentiometer. In all there are twenty-four sensors which communicate with the computer 200 in reference to position.
These sensors are potentiometers. Alternatively optical encoders could be used. With the potentiometers the scales for all sensors are as follows:
1. Electrical signal 0 volts to 5.12 volts dc equivalent to 256 decimal divisions or one 8 BITS BYTE. This means that 1 bit is equal to 20 mV.
2. One BYTE equal to two Radians or 114.6 degrees.
3. When the control stick 20, control wheel 18 and sensor 60 are neutral 2.56 volts are output from all associated sensors. When the angles A, B and C are each half-way between a fully extended and fully retracted position the output is 2.56 volts. The height switch has a range from 0.3 volts to 1.2 volts.
In other words, when any of the angles, A, B and/or C, are one-half range, this equals one radian; when full range this equals two radians and where zero range, this equals zero radians.
The analog to digital converter changes these signals to 128 decimal. The computer substracts 128 decimal from any reading received such that it is a conversion from; 0 to 5.12 VDC =0 to 256 decimal, to; 0-5.12 VDC=-128 to 128.
An optical encoder if used is scaled in the same way (1 radian equal to 128 division). In this instance the signal would go digitally directly from the optical encoder to the computer interface.
4. Each bit represents 1 inch in linear movement.
If we move the control stick full forward or one radian (57.3 degrees) we are going to read 128 decimal (or 128 inches per computer loop per second, this means 12.66 feet per loop, there are five of these loops per second). Full speed means 63.33 feet per second or approximately 43.18 mph. In actuality full speed will be somewhat less than this because of hydraulic shock waves.
Routine DELTA step 11 limits forward speed, step 20 limits backward speed. (The example of this application is limited to 10 units or 50 inches/sec., equivalent to 3 mph.)
Summary:
Scales--
1 bit=1 inch
1 bit=0.055 radian=20 mv
1 BYTE=2 radians
1 Radian=2.56 volt=57.2 degrees.
Those scales apply to all sensors and all controls.
The Computer
An electrical functional block diagram of the computer 200 is shown in FIG. 20. The computer 200 used in the preferred embodiment is a microprocessor such as an 8085 miniprocessor available from Intel Corporation Santa Clara, Calif. Two interfaces for input, output and random access memory such as Intel's 8155 was used; and two interfaces for input, output and programmable read only memories such as Intel's 8755 are also used. Components are connected according to a standard system configuration such as found in the manual published by Intel Corporation, MC5-85 User manual, Appendix 1, pages A1--1 through A1-5; and FIG. 3 which manual is hereby incorporated in this application in its entirety. Three single chip data acquisitions systems such as National Semiconductors adc0816 are connected to the interface, and the address lines of the data acquisition systems are connected also to the address lines to the computer and the 8205 selection Ic's in the computer. Reference to FIG. 20 will show all inputs to and from the computer.
The control of the computer is accomplished through the instructions. The instructions are written in terms of the particular mode of operation desired. The computer 200 thus has stored in its memory the programs and routines corresponding to each mode of operation.
As is well known to those skilled in the art the computer comprises suitable control, storage and computational units for performing various arithmetic functions on data which is presented in digital form. Any standard computer language consistent with the capability of the computer can be used for the instructions. All sub-routines are not described in detail since they can be written upon a particular computer being utilized, the computer language, etc. Programs and instructions described below are put in terms of structural flow. When necessary and applicable for purposes of the invention, the individual programs are described.
All controls initiate and return to and from the main program depending upon the mode of operation.
In the main program the first fifteen steps typically comprise the main loop. Within the main loop, as is understood in computer programming there may be one or more sub-loops. In this invention for the preferred embodiment, there are six such sub-loops. Each of the six legs is handled sequentially. When the pointer is set to 1 for leg loop 1 NN=1 then all various sub-routines, etc. are completed for leg 1. At its completion then the pointer is set to 2 for leg loop 2 and so on until the completion of leg loop 6.
In the discussion of the programs for this embodiment the following sets forth the relationship between the computer language and the legs. ##SPC1## ##SPC2## ##SPC3##
Leg Movement Formulas
The following formulas in combination with the graphical representations of FIGS. 9 and 10 illustrate the basis of the functioning of the articulated legs of the invention.
1. When a >0
∠cc=Arctan a.sub.h
b=h/coscc
∠D=ArcCos (b/2)/c
∠A/2=π/2-∠D
π/2=∠B+∠CC+∠D
∠B=π/2-∠D-∠CC
∠B=∠A/2-∠CC
2. When a <0
∠CC=Arctan (a/h)
b=h/cosCC
∠D=ArcCos(b/2/c)
∠A/2=∠/2-∠D
∠B=π/2-(∠D-∠CC)
∠B=π/2-∠D+∠CC
∠B=∠A/2+∠CC
The limit of any leg movement is illustrated in FIGS. 10a and 10b and the tables set forth below.
______________________________________Table for the Retrace or Regress Limit of the Legs Machine Machine Forward Movement Reverse Movement legs 2,3,5,6 legs 1,4 legs 2,3,5,6 legs 1,4______________________________________ ##STR1## [a.sub.n ] > h.sub.n ##STR2## ##STR3## [a.sub.n ] > h.sub.n ##STR4## ##STR5## [a.sub.n ] = h.sub.n [a.sub.n ] = h.sub.n ##STR6##______________________________________
By incrementing values of a (a=a+Δa) and keeping delta a/t (time) constant we create constant speed. The input into the computer 200 as described generates values of angle A or angle A/2 and angle B for each new value of "a". The value of h is determined by the desired height, the vehicle balance and the control wheel 18. If the ground is flat all "h" are the same. If the ground is irregular then there will be different values of "h" for each of the legs. (Sub. "SETH", Sec. B, Steps 1 to 33)
The "h" value for any leg is kept constant during each trace. In the description of the operation of the invention only certain movements of the machine will be described in detail for illustrative purposes. It will be apparent to those skilled in the art based on the description of the structure and function of the vehicle together with the programs provided that an almost infinitesimal amount of various movements are possible.
In this example the movements described in detail will consist of vehicle balance and moving forward on a flat surface, turning around a point and steering; moving across a mountain slope, leg adjusting to obstacles; and braking and backward and side motion.
Vehicle Balance and Moving on A Flat Surface
The vehicle is four feet in width, eight feet long and with the legs fully extended the bottom surface of the platform is sixty inches from the surface.
The computer 200 is initialized and the engine 22 started and the fluid pump 24 raised to the appropriate pressure.
The computer 200 checks the sensors 388 and 390 of the gimbal-pendulum 60 to determine if the vehicle 10 is balanced, program steps 2, 3, 12 in sub-routine SET h. For example, if the vehicle 10 is tilted about the Y axis as shown in FIG. 3 (angle R>0) legs 40, 42 and 44 are lower than legs 46, 48 and 50. The "h" height of each leg is then analyzed by the computer 200 and is balanced changing h4, h6 for legs 40, 44, in sub-routine SET h Steps 4-6.
Each leg has pressure-sensitive ground switches which output a signal when the leg contacts either an obstacle or the ground. The sense switches 396 for leg 40 are shown in FIGS. 5 and 6.
As is apparent from the sub-routine SET h when the vehicle 10 is balanced only the four corner legs 40, 44, 46 and 50 are initially controlled. The computer determines which legs should be raised or lowered based on the present leg height h and the distance of the leg loop. When balance is achieved the signals from the sense switches of the two middle legs 42 and 48 are checked to determine whether or not they are in contact with ground; if not they are extended until they contact ground and balance is complete. (SET h, steps 13-17)
In order to increase or decrease the height of each of the legs the computer controls the angle A and angle B values of each leg. These angles are calculated based on the desired height (actual h plus a change in h=h+Δh) and the actual value of "a". Referring to FIG. 5, for leg 40, the sensors 360 (∠A) and 362 (∠B) provide signals to the computer 200. The computer determines the amount of movement of each of the legs. For leg 40 outputs to the solenoid valves 314 and 316 are sent and the corresponding cylinders 320 and 322 are actuated. This sequence of calculations the desired angles, measuring the actual angles and actuating the associated cylinders to move the legs to the calculated values is done for each leg. The solenoid valves on the left side of the vehicle 10 referring to FIG. 3 are opened and the valves of the right side referring to FIG. 3 are closed until the actual angle A's and angle B's are equal to the calculated angles. At this point we have the desired height equal to the actual height. These steps are repeated for each and every leg until balance is achieved. Where the vehicle 10 is tilted around the X axis (angle P>0) legs 46 and 40 are increased (SUB-ROUTINE SETH Step 29) and legs 44 and 50 are decreased (SUB-ROUTINE SETH Step 32) until balance is achieved using the same h concept. Again the corner legs are moved to achieve the desired balance. Subsequently the side legs are actuated to engage the ground to stabilize the vehicle.
Moving On A Surface
Once balance is achieved the vehicle 10 is ready to move. The operator moves the control stick 20. Movement of the stick 20 changes the position of the sensing device 21 (FIG. 8b). The device 21 has two sensors as previously described. If the operator moves the control stick forward the machine will move forward at a speed specified by the amount of stick forward movement. When the operator desires to stop he moves the control stick backward to a center (neutral) position. If the operator wants to move sideward he moves the control stick sidewards.
The computer 200 will increase the value of "a" for each leg according to the amount of movement of the control stick 20 (SUB-ROUTINE "DELTA" Steps 8, 18). This increment of "a" will be constant as far as the stick 20 is offset from its neutral position. If the rate of change of "a" is constant per unit of time then the speed will be constant. The distance "a" is shown in FIGS. 10a and 10b. For each increment of the distance "a" in each leg, the computer will calculate angle A and angle B using formulas I and II set forth above (SUB-ROUTINE CALC SEC. E Steps 1 to 23).
The leg height h is going to be constant during the forward or trace cycle. This value h will change only at the beginning of the retract cycle and at the beginning of the next leg cycle when the leg is going to be adjusted to a new location on the ground and the balance is checked again. It is to be understood that during the trace cycle the foot of the leg remains fixed on the ground while the vehicle moves. This may be seen in FIGS. 11-14.
Turning On A Flat And An Irregular Surface
To turn around its center on or about the Z axis, referring to FIG. 3, the control wheel 18 is turned. Each leg will move around a circle with its radius equal to the distance between CT and the position of the leg at the time turning is commenced. The computer selects the values of "d" and "a" for each leg such that the net effect will be to turn the vehicle around CT (SUB-ROUTINE DELTA Steps 29 to 51). The radius R is calculated at the leg start movement for each and every leg for precision turning. The leg displacement is going to be controlled by X 2 +Y 2 =R 2 when Y=a n (a n is the actual leg "a" value plus the distance from "X" axis) for each leg or for n=1, 2 . . . 6. The control wheel 18 is connected to a shaft at the end of which is the wheel position sensing device 19. Change in position of the optical encoder generates a corresponding change in electrical signal (1 RADIAN=57.3°=128D=2.56 volt DC 1 turn/sec) which is input to the computer 200. In this way the computer determines the desired turning ratio (1/128 turn sec per bit) and now has the desired ratio to control the leg movement. The computer 200 calculates the corresponding values of X and Y. If the vehicle 10 is moving and turning at the same time the value of "Y" corresponding to the turn ratio is incremented by delta a (change in a) corresponding to the forward or backward movement. The displacements along the X axis (FIG. 4) are going to be achieved by changing the ∠C corresponding to each leg when turning and moving either forward or backward. Sideward or lateral movement is achieved by changing angle C (∠C) with respect to time in a similar way as "a" is changed with respect to time (ROUTINE DELTA Steps 53 to 55).
Moving Across A Sloped Surface
When a=0 and h is constant then there are no changes of a in time and the machine clearly does not move. As soon as "a" by movement of the stick 20 is incremented (a n+ 1=a n +Δa) which essentially means a new value for "a", the old values of angle A and angle B are calculated and the actual angle A and angle B are changed to the calculated values and the net result is forward movement.
When a reaches the established limit ("a" value for the leg in relation to its "h" value) the retract sequence starts (See RETRACT LIMIT TABLE). The value of h is reduced, the computer checks to determine if there are other legs in the retract mode at the same time before starting retrace in leg 40, for example (SUB-ROUTINE RETRO Steps 7, 28 to 30, for leg 40). The value of h is reduced to a preset value specifically h/4 (SUB-ROUTINE RETRO Step 52) then the leg synchronization routine (RETRO Step 1 to 50) sets the time when the next leg trace should start. The value of "a" is reduced to the preset value according to the retrace limit table. When the trace starts values of "a" are incremented again, values of "a" are incremented at the same time as the other machine legs are, in order to allow this leg to be moving at machine speed when it engages the ground. Ground is detected when the ground sense switch is closed (SUB. RETRO Steps 58 and 59). Now values of "h" start to be incremented until the gimbal-pendulum sensor 60 feels an unbalance (this feature allows the leg to be adjusted to the terrain). Any obstacle is cleared because the leg height is divided by 4 during retract (FIGS. 15 and 16). If there is an obstacle the leg is going to be adjusted to it if it has not been cleared in the retrace mode (FIGS. 17 and 18).
When the vehicle 10 is moving across a mountain slope the legs of both sides are going to be adjusted until balance is achieved. Any obstacle will be handled in the same way. If the obstacle is too big to be cleared the vehicle will stop indicating that the leg cannot clear the obstacle.
If a leg through its retract (loop) cannot clear the obstacle then the sense switch such as 396, leg 40, will be actuated when it hits the obstacle before the leg has completed its maximum retract (SUB-ROUTINE RETRO Step 58).
This will place the vehicle in a hold position and the operator must then move in a different direction to avoid the obstacle which cannot be overcome (SUB-ROUTINE RETRO Step 58).
Leg Adjustment To Obstacles
The angles A and B in each leg are adjusted based on the value of "a" and the value of "h". Once established the value of "h" is kept constant during trace while the value of "a" is going to change with time. Referring to FIG. 11, "a"=0. As the vehicle moves forward, FIG. 12, "a" increases. When the value of "a" is equal to a preset value measured in terms of the h and conditioned to the position of the other legs, to avoid one hitting the other (For LEG 40 IN FORWARD, RETRO Step 67) all retracing at the same time (Example: SUB-ROUTINE RETRO Steps 7, 29 to 30 prevent Leg 40 retrace at the same time as leg 42 or 44 is retracting), or any other desirable condition, the leg starts the retrace action as shown in FIG. 13.
Initially the value of "h" is decreased, FIG. 14. Then the value of "a" is decreased to the preset value, FIGS. 15 and 16. Decreasing h while "a" is changing allows the leg to be moving at the vehicle's speed at lift-off time.
After checking the leg synchronization computer routine (for the forward cycle start time) the leg starts the forward motion increasing h until an imbalance is sensed due to this leg movement, FIG. 17. The leg h value is fixed by the computer until the leg will start the retrace cycle again. The forward movement continues. The first obstacle has been cleared and the leg adjusted to the next obstacle as shown in FIG. 18. Now the leg is ready to commence the retrace "a" and having established the retraced relation with "h". The h value for this leg will be smaller in this case due to the obstacle. In case of a slope or an obstacle each leg is adjusted individually until balance is achieved.
Braking Backward Motion, Sideward Motion and Bank Effect
If the vehicle 10 is moving forward at constant speed then "delta a"/"delta t" is constant (rate of change of "a" is constant with time because "a" is distance).
ds/dt=v
d.sup.2 s/dt.sup.2 =dv=A
s=∫vdt
s=distance=a
v=velocity
A=acceleration
If we reduce the rate of change of "a" with respect to time, deceleration or braking will result. If "a" increases 10 units per second the machine is moving 10 units per second when the stick 20 is moved closed to the neutral position, and the level of this signal is two units per second the computer senses the change in position and "a" is reduced by 2 units every second wherein the machine will brake in 5 seconds. When the machine is braking the gimbal-pendulum arrangement 60 moves forward then the computer senses this movement and maintains the balance of the vehicle in reference to the pendulum. The computer will increase h1 (leg 50), h4 (leg 44) and decrease h3 (leg 48), h6 (leg 40) in order to maintain the balance. The net result will be the front is higher than the back while braking.
Backward Motion
The concepts that apply to forward motion equally apply to reverse motion but with opposite signs. In reverse when the control stick 20 is pulled rearwardly from the neutral position and sensed by the computer, the legs start their trace at the opposite point of forward. The value of "a" decrements with time instead of increments. The leg regress or retrace starts at the same point as with the leg start trace in the forward motion.
Side Motion
In sideward movement angle C is changed with time (delta "d"/time) until its limit (MAIN PROGRAM Step 6) is reached then h is decreased as before and the retract cycle starts. The angle C is changed to the other extreme--C and h starts to increase until balance is achieved. The HH value (the real leg length) will be equal to h/cos C. The "h" value will be constant but HH will be a sinusoidal function of C. This is set forth in the program identified as "CALC" steps 2 and 3. Sideward acceleration will affect the gimbal-pendulum 60 and the computer will adjust the vehicle to it in the same manner as when turning.
For example the control stick 21 is moved 12 degrees sideward (approximately 1/5 Radian), the sensor sends a 500 mv signal that is changed to 25 decimal in the computer 200. If an optical encoder is used it will send the 25 decimal or 31 octal signal directly to computer interface (SUB-ROUTINE DELTA Step 54). This is the "delta d" value and it is added to "d" (SUB. DELTA Step 55). The angle C necessary for this new value of "d" will be equal to ARCTAN d/h ("CALC" Step 3). Once the angle C is calculated based on "d" and "h" we are ready to control Routine CONTROL STEPS 1 to 11. The solenoids that control ∠C for each leg (in sequence are actuated) such that angle C desired will be equal to angle C actual as determined from the leg sensors. The control sub-routine for angle A for all legs has been detailed. The same routine format is used for all angle B and all angle C of all legs.
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A vehicle with articulated legs is provided for movement across a surface or through water. Each of the legs is adapted to move in at least two planes with reference to vehicle balance. The movement of the legs is controlled sequentially to effect movement over an uneven surface while maintaining the vehicle balance.
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BACKGROUND OF THE INVENTION
Lipase enzymes are known to catalyze hydrolysis of triglycerides and other fats in accordance with the following reaction: ##STR1##
The lipase enzyme hydrolysis reaction requires water as a reactant, as indicated above. Lipase enzyme is a hydrophilic protein, and water is its natural environment, so that lipase enzyme-catalyzed reactions normally are carried out in an aqueous medium.
Recently, it has been found that some enzymes, among them lipases, also hydrolyze fats in organic solvent media. Water-miscible solvents, such as ethanol and acetone, cannot be used because of their denaturating effect on the enzymes. For example, aqueous alcohol solutions are used for wound treatment, because of their denaturating effect. However, hydrocarbons such as hexane and petroleum ether are effective in lipase-catalyzed hydrolysis, because the enzymes are stable in such solvents, but water as a reactant must be present, although the amount of water can be quite small. If the solvent system is anhydrous, i.e., if no water is present, the lipase catalyzes ester formation, i.e., the reverse reaction between fatty acid and glycerol to form a triglyceride, but not the hydrolysis of the triglyceride to form fatty acid and glycerol. Thus, it is possible simply by controlling the amount of water present to carry out either hydrolysis or condensation, using lipase enzymes. The water need not even be present in a water phase, or distributed in the organic solvent, but can also be hydrated or absorbed on a sorbent such as Celite or calcium carbonate, which is then dispersed in the organic solvent.
The fact that enzymes can function in what is essentially an anhydrous environment containing little or no water has expanded the range of utilization of enzyme-catalyzed reactions in organic synthesis. Both hydrolyses and condensations can be carried out, and solubility problems with organic substrates in water can be avoided, since organic solvents can be substituted for the water.
The use of lipases in condensation reactions of fatty acids with glycerol is of no practical interest, Because the triglycerides are available as raw materials in any desired quantities, and are inexpensive. However, transesterification of naturally-occurring triglycerides, or triglycerides prepared from naturally-occurring fats and oils, is of interest, because this enables the substitution of any desired combination of fatty acid groups in selected positions on the triglyceride. It is accordingly possible, starting from inexpensive naturally-occurring or prepared triglycerides, to prepare by transesterification triglycerides substituted with fatty acid groups in combinations that do not exist or are rarely found in nature. Since many lipase enzymes are selective in the positions which they attack in transesterification reactions on the triglyceride molecule, it is possible to incorporate the desired fatty acid groups in any selected position on the triglyceride molecule, i.e. positions 1, 2, or 3, or a random distribution of all three.
K. Yokozeki et al, Europ J. Appl Microbiol Biotechnol 14 1 (1982); T. Tanaka et al, Agric Biol Chem, 45 2387 (1981); and M. H. Coleman and A. R. Macrae, U.S. Pat. No. 4,275,081, patented June 30, 1981, describe the transesterification of triglycerides using position-specific lipases such as Rhizopus delemar to convert inexpensive triglyceride distillation fractions derived from palm oil and olive oil to a fatty acid composition and distribution which corresponds to that of cocoa butter. Natural cocoa butter is in very short supply, and quite expensive.
The chemical reaction in this transesterification can be illustrated as follows: ##STR2## in which S is stearic acid, P is palmitic acid, and O is oleic acid. A mixture of stearic acid and a triglyceride with palmitic acid residues in positions 1 and 3 and an oleic acid residue in position 2 has been converted into a mixture of palmitic acid and a new triglyceride where the stearic acid residue now is in positions 1 and 3. The 1,3-specific lipase enzyme catalyzes a transesterification reaction in positions 1 and 3, and leaves position 2 intact.
Of course, other reactions take place as well, because palm oil or olive oil is not a pure P--O--P triglyceride, and cocoa butter is not a pure S--O--P triglyceride, but the above reaction does constitute a meaningful representation of what primarily takes place.
The process as described in the literature quoted above is preferably carried out in hexane or other aliphatic hydrocarbon. However, the reaction rate is slow, and reaction times of the order of 40 to 50 hours are required, to bring the transesterification to completion. The reaction temperature is effectively limited to 40° C., because of enzyme instability at higher temperatures, and so it is not possible to overcome the slow reaction rate by increasing the reaction temperature. Thus, the process has not been commercialized, because such long reaction times make the process uneconomic.
SUMMARY OF THE INVENTION
In accordance with the present invention, these difficulties are overcome by carrying out the reaction in a microemulsion comprising a hydrophobic component, a surface-active component, and water. In such a reaction medium, lipase enzyme rapidly transesterifies triglycerides, and by selection of the enzyme and the fatty acid that is transesterified with the triglyceride, it is possible to obtain any combination of fatty acid groups in the triglyceride, and these groups will be located according to the position-specificity of the lipase enzyme.
DETAILED DESCRIPTION OF THE INVENTION
Under normal reaction conditions, normal reaction temperatures within the range from about 25° to about 40° C., it is possible to reduce the reaction time to one-tenth of the time required in hexane or other aliphatic hydrocarbons, under the same reaction conditions.
The amount of water is not critical, but there is no reason to use large amounts of water. The maximum amount of water is that which would be tolerated in the microemulsion without making the microemulsion unstable, i.e. susceptible to phase separation.
Normally, the water content in the microemulsion should not exceed about 4% by weight, and preferably the amount is within the range from about 0.3 to about 2% by weight, still more preferably within the range from about 0.1 to about 2% by weight. At amounts of water in excess of about 4%, under some conditions, with certain enzymes, hydrolysis of the triglyceride may set in as a competing reaction, and the amount of triglyceride yield may be reduced.
The amount of lipase enzyme in the microemulsion is not critical, either, but a small amount is usually adequate to catalyze the reaction at a rapid rate. A suitable amount is within the range from about 0.1 to about 10 mg per 100 g of triglyceride, i.e., from about 0.1 to about 10% by weight of the triglyceride.
Any lipase enzyme capable of catalyzing the transesterification reaction can be used. These lipase enzymes are known, and are described in the literature. Exemplary are: Aspergillus niger, Pseudomonas fluorescens, Numicola languinosa, Chromobacterium viscosum and the various Rhizopus and Mucor species, such as Rhizopus delemar.
A microemulsion is a thermodynamically stable solution of an organic solvent immiscible in water together with a surface-active component having a hydrophobic group and a surface-active group, and water. The surface-active component serves as a stabilizer for the microemulsion.
The organic solvent component of the emulsion that is immiscible in water is preferably a hydrocarbon that is inert under the reaction conditions. Aliphatic hydrocarbons, such as hexane, heptane, isooctane, isoheptane, nonane, decane, undecane, dodecane, tridecane and tetradecane, can be used. Also useful are cycloaliphatic hydrocarbons, such as cyclopentane, cyclohexane and cycloheptane, as well as mixed hydrocarbons obtained from natural sources, such as for example petroleum or coal tar, for example, paraffin hydrocarbon solvents and petroleum ether boiling in the 60° to 80° C. range.
The water may also contain a buffer to provide a pH which is acceptable for the enzyme. Such buffers are known and form no part of theinstant invention; sodium bicarbonate, sodium monohydrogen phosphate, and sodium dihydrogen phosphate are exemplary.
As surface-active components providing both a hydrophobic group and a surface-active group, there can be used anionic, cationic, amphoteric and nonionic surface-active agents.
Exemplary anionic surface-active agents are the alkyl sulfates, alkylaryl sufonates, alkyl sulfonates, aryl sulfonates, sulfated fatty oils and acids, sulfated polyoxyalkylene glycol ethers and amidoalkane sulfonates.
The alkyl sulfonates are defined by the structure R--SO 3 --M where R represents a long chain saturated or unsaturated aliphatic group having from eight to eighteen carbon atoms, such as the mixed sodium alkane sulfonates derived from petroleum, sodium decane sulfonate, sodium dodecane sulfonate and sodium octadecane sulfonate.
The alkyl sulfates are the sulfated long chain alkyl alcohols having the formula R--O--SO 3 --M such as sodium lauryl sulfate, sodium palmityl sulfate, sodium octadecyl sulfate, sodium decyl sulfate and sodium octyl sulfate.
The aryl sulfonates and alkyl aryl sulfonates contain an aromatic ring having sulfonate groups attached to one or more of the ring carbon atoms. The alkyl aryl sulfonates have in addition an alkyl group having from one to sixteen carbon atoms. Both are defined by the chemical structure; ##STR3## where R can be hydrogen or an alkyl group having from three to eighteen carbon atoms and m is the number of such groups and has a value from one to about four. Typical are sodium benzene sulfonate, sodium toluene sulfonate, sodium xylene sulfonate, sodium dodecyl benzene sulfonate, and sodium lauryl benzene sulfonate. One group of these compounds, the sodium polypropylene benzene sulfonates, is described in U.S. Pat. No. 2,477,383 to Lewis. Also useful are the sodium keryl benzene sulfonates.
The amidoalkane sulfonates are characterized by the structure of an amide, of which the nitrogen is attached through an alkylene group to the sulfonate radical, and have the structure: ##STR4## n is a small whole number from 1 to about 5, preferably 2 or 3, R' is hydrogen or an alkyl, aryl, or cycloaliphatic group, such as methyl, and R is an alkyl or alkylene radical, such as myristyl, palmityl, oleyl and stearyl. Sodium plamitic tauride, sodium plamitic methyl tauride, sodium myristic methyl tauride, sodium palmitic-stearic methyl tauride and sodium palmitic methyl amidopropane sulfonate are typical examples thereof. These are amphoteric.
The sulfonated acids and esters of organic acids also are useful, particularly the sulfuric acid esters of aliphatic acids of eight to twenty carbon atoms, particularly oleic acid, tall oil acids, turkey red oil acids, and acids derived by the reduction of the fatty acids derived from coconut oil, palm oil, sperm oil and the like long-chain fatty acids, sulfonated castor oil, esters and ethers of isethionic acid (beta hydroxyethylene sulfuric acid) and the esters and ethers of the acid sulfate of isethionic acid, i.e., ethionic acid, such as for example lauroylcycloimidinium-1-ethoxy-ethionic acid 2-ethionic acid, long-chain fatty acid esters and long-chain alkyl ethers of 2,3-dihydroxypropane sulfonic acid, and sulfuric acid esters of monoglycerides and glycerol monoethers.
The sulfated polyoxyalkylene glycol ethers have the structure R--A--(YO) x --Y--O--SO 3 M. These compounds are in every respect the same as the polyoxyalkylene glycol ethers described below, with the addition of the sulfate group O--SO 3 --M.
In all of the above formulae, it will be understood that M represents hydrogen, or a monovalent inorganic cation such as sodium, potassium or ammonium, or a monovalent organic cation such as a highly basic amine, for example triethanolamine, diethanolamine, monoethanolamine or tributylamine.
Examples of suitable anionic compounds are di-(2-ethylhexyl) sulphosuccinate, and carboxy-methylated nonyl phenol ethyxylate containing 1-4 ethyleneoxy groups.
Also useful are the phosphate esters of the formula: ##STR5## or alkali salts or ammonium salts thereof, in which R 1 and R 2 represent hydrogen or a group R(OC 2 H 4 ) n where R represents a saturated or unsaturated, straight or branched alkyl or alkenyl radical having a total of 4-22, preferably 8-18, carbon atoms in the alkyl or alkenyl portion or a mono, di or trialkyl substituted phenol having a total of 6-24, preferably 8-18 carbon atoms in the alkyl portion, wherewith R 1 and R 2 do not at the same time comprise hydrogen, and n is 0-30, preferably 5-25.
The corresponding phosphonate esters of similar structure ##STR6## are also useful, as well as phospholipids, such as lecithin, which contain both phosphate and quaternary ammonium groups.
The nonionic surface active agents include polyoxyalkylene glycol ethers defined by the following general formula:
R--A--(Y--O).sub.x --Y--OH
wherein R is a straight or branched chain saturated or unsaturated hydrocarbon group having from about eight to about twenty-four carbon atoms, or an aralkyl group having a straight or branched chain saturated or unsaturated hydrocarbon group of from about eight to about twelve carbon atoms attached to the aryl nucleus, the aralkyl group being attached to A through the aryl nucleus. A is selected from the group consisting of ethereal oxygen and sulfur, amino, carboxylic ester and thio carboxylic ester groups. Y represents a straight or branched chain alkylene group having from two to four carbon atoms and x is a number from about 3 to about 20, preferably 3 to 8.
R can for example be a straight or branched chain alkyl group, such as octyl, nonyl, decyl, lauryl, myristyl, cetyl or stearyl; an alkylene group, such as hexenyl, dodecenyl, oleyl, linoleyl, ricinoleyl, or linolenyl; or an alkyl aryl group, such as octyl phenyl, nonyl phenyl, decyl phenyl, dodecyl phenyl, or isooctyl phenyl. Y can be ethylene, 1-methylethylene, 1,2-diethylethylene, 1,1-diethylmethylene, 1,3-propylene and 1-butylene.
When R is alkyl, it will be evident that the polyoxyalkylene glycol ether can be regarded as derived from an alcohol, mercaptan, amine, or an oxy or fatty acid of high molecular weight, by condensation with an alkylene oxide, for example, ethylene oxide, 1,2-propylene oxide, 2,3-butylene oxide or 1,2-butylene oxide. Typical of this type of product are the condensation products of oleyl, stearyl, lauryl, palmityl, and mydristic alcohol, mercaptan or amine or oleic, lauric, palmitic, myristic or stearic acid, with from 8 to 1 moles of ethylene oxide such as Emulfor-ON, Nonic 218, Sterox SE and Sterox SK. Typical alkyl esters are Renex (polyoxyethylene ester of tall oil acids) and Neutronyx 330, and 331, higher fatty acid of polyethylene glycol.
When R is aralkyl the polyoxyalkylene glycol ether can be derived from an alkyl phenol or thiophenol.
Examples of such compounds are ethylene oxide adducts of nonyl phenol, octyl phenol and fatty alcohols. Monoglycerides are another preferred group of nonionic surfactants.
The polyoxyalkylene alkyl phenols and thiophenols have the following general formula: ##STR7## where R is a straight or branched chain saturated or unsaturated hydrocarbon group having from about eight to about eighteen carbon atoms, A is oxygen or sulfur, and x is a number from 8 to 20. R can, for example, be a straight or branched chain octyl, nonyl, decyl, lauryl, cetyl, myristyl or stearyl group. Typical are the condensation products of octyl and nonyl phenol and thiophenol with from 8 to 17 moles of ethylene oxide, available commercially under the tradenames "Igepal CA" and "CO", NIW, Antarox A 400, Triton X-100, Neutronyx 600 and Tergitol NFX.
Also useful are the mixed polyoxyethylene oxypropylene ethers having the formula:
Y.sub.n (C.sub.2 H.sub.4 O).sub.x (C.sub.3 H.sub.6 O).sub.m (C.sub.2 H.sub.4 O).sub.yp H.sub.n
These compounds are described in U.S. Pat. Nos. 2,674,619 to Lundsted, dated Apr. 6, 1954, and 2,677,700 to Jackson et al, dated May 6, 1954. They are condensates of a 1,2-alkylene oxide, such as 1,2-propylene oxide and 1,2-ethylene oxide, the ethylene oxide residues constituting from 20 to 90 percent of the resulting concentrate. Y as defined in these patents is the residue of an organic compound containing therein a single hydrogen atom capable of reacting with a 1,2-alkylene oxide, and the total of x and y is from 2 to 20. x and y may also be zero. n is a number from 1 to 25; p is a number from 1 to 5, and the average weight of the entire block polymer is from 1,000 to 4,000.
Organic compounds suitable for forming Y are compounds in which the hydrogen atoms are activated by an oxygen atom, such as in a hydroxyl group, a phenol group or a carboxyl group, or by a basic nitrogen atom, such as in an amine group and amide group, a sulfamide group, a carbamide group, and a thiocarbamide group, or by a sulfur atom, such as in a mercaptan.
Exemplary Y compounds are glycerol, ethylene glycol, propylene glycol, ethanol, ethanol, isopropanol, n-butanol, 2-ethylhexanol, lauryl alcohol, cetyl alcohol, stearyl alcohol, eicosanol, oleyl alcohol, so-called OXO-alcohol mixtures, butanediol, pentaerythritol, oxalic acid, triethanolamine, aniline, resorcinol, triisopropanolamine, sucrose, ethylenediamine, diethylenetriamine, acetamide, coconut oil fatty amine, methyl mercaptan, dodecyl mercaptan, hexadecyl mercaptan, etc.
Exemplary of this type of nonionic surfactants are propylene glycol condensed with 20 moles of propylene oxide and then with 5 moles of ethylene oxide, Y being hydroxyl, n=1, x+y=5, m=21, and p=1, as well as ethylene diamine with which have been condensed 12 moles of propylene oxide followed by 10 moles of ethylene oxide, Y being an ethylene diamine residue, n=4, x=0, y=2.5, m=3, and p=4.
Another type of polyoxyalkylene glycol ether surfactants has the formula: ##STR8## Y is an organic residue as defined above, and R 1 , R 2 , R 3 and R 4 are selected from the group consisting of hydrogen, aliphatic and aromatic radicals, at least one of these substituents not being hydrogen. n is a number greater than 6.4, as determed by hydroxyl number, and X is a water-solubilizing group, as defined in U.S. Pat. Nos. 2,674,691 and 2,677,700.
Exemplary of this type of compound are the fatty alcohol styrene oxide condensates containing 7 moles of styrene oxide, with the water-solubilizing group X being 70 moles of ethylene oxide.
Among nonionic surfactants, polyethylene glycol is the preferred hydrophilic component, and the average length of the polyethyleneglycol chain is between 3 and 8 ethylene oxide units. The hydrophobic part may be derived from hydroxyl compounds or carboxyl compounds containing an alkyl chain of 8 to 20 carbon atoms, or an alkylaryl group of 9 to 24 carbon atoms.
Useful cationic surface active components include quaternary ammonium lower alkyl and/or lower alkanol and/or polyoxyalkylene alkanol salts which have the formula: ##STR9##
In the above formula, from one to four of R 1 , R 2 , R 3 and R 4 are saturated aliphatic hydrocarbon radicals having from one to about four carbon atoms; and/or from one to four of R 1 , R 2 , R 3 and R 4 are hydroxyalkyl or polyoxyalkylene radicals terminating in a hydroxyl group, and having a formula selected from the group consisting of (C 2 H 4 O) m H, (C 3 H 6 O) p H and (C 4 H 8 O)H, wherein m is an integer from one to ten, p is an integer from one to five, and q is an integer from one to two; and mixtures of two or more thereof. Thus, all of the R radicals are either saturated lower aliphatic hydrocarbon radicals or hydroxyalkyl or hydroxyalkylene polyoxyalkylene radicals of these types.
X is an inorganic anion, and is preferably selected from the group consisting of HSO 4 , CH 3 SO 4 , C 2 H 5 SO 4 , Cl and Br.
Additional cationic wetting agents are the higher fatty acid esters of hydroxy amide quaternary salts, such as the lauric ester of N(β-hydroxyethyl-α-chloropyridinium)acetamide, the quaternary ammonium salt type, such as triamylbutylammonium cymene sulfonate, cetyl pyridinium bromide, oleyl pyridinium chloride, dimethyl phenyl benzyl ammonium salt of dibutyl-naphthalene sulfonic acid, trimethyl heptyl ammonium salt of sulfated butyl oleate, octadecyl trimethyl ammonium chloride, straight chain fatty amines of eight to eighteen carbon atoms, such as stearylamine, dilaurylamine, lauryl di(hydroxy ethyl)amine, the polyamines made from the reduction of polymerized unsaturated fatty nitriles, i.e., the polymerized nitrile of linseed oil fatty acids, and the quaternary compounds from alkyl halides and hexamethylene tetramine, the reaction products of α-halogenated fatty acid anilides or esters such as α-chloro-stearic anilide or α-bromo-stearic ethyl ester with tertiary amines such as trimethylamine, reaction products of long chain alkyl phenols with amines and aldehydes, such as the reaction product of p-t-octylphenol with formaldehyde and dimethylamine, which products may also be quaternized, such as ##STR10## where R is an alkyl group of six to eighteen carbon atoms, the amidoalkylene amines RCONHCH 2 CH 2 N--R 1 R 2 where R is an alkyl group of six to eighteen carbon atoms, and R 1 and R 2 are alkyl or hydroxyalkyl groups of one to five carbon atoms (the Sapamines), the amidoalkylene quaternary ammonium salts ##STR11## where R is as above, R 1 , R 2 and R 3 are alkyl or aryl or alkaryl, and X is an anion such as halide, alkyl ether amines of the type ROCH 2 NR 1 R 2 and their quaternary ammonium salts ROCH 2 NR 1 R 2 R 3 X where R, R 1 , R 2 , R 3 and X are as above, the corresponding thio ethers RSCH 2 NR 1 R 2 and RSCH 2 NR 1 R 2 R 3 X, the long-chain alkyl sulfonium compounds of the type ##STR12## where R, R 1 , R 2 and X are as above; such as cetyl methyl ethyl sulfonium bromide, and amido sulfonium salts of the type ##STR13## where R, R 1 , R 2 and X are as above, and the Victamines ##STR14## where R and R 1 are as above, such as that made from stearylamine and ethyl metaphosphate: ##STR15##
In addition to the surface-active component, the microemulsion can include an auxillary surfactant, which is usually a low molecular weight alcohol or glycol ether, and forms no part of the instant invention.
Examples of conventional substances of this type are butanol, pentanol, hexanol, butyl glycol and butyl diglycol.
It has proved especially advantageous to use a surface-active component capable of forming microemulsions without an auxiliary surfactant. Exemplary of such surface-active components are the polyoxyalkylene glycol esters described above, as well as anionic compounds having the anionic hydrophilic group in a nonterminal position on a hydrocarbon chain.
In general, the microemulsion suitable as a reaction medium for the process of the invention contains:
(1) an amount within the range from about 81 to about 99.8%, preferably from about 93 to about 99%, by weight of the hydrophobic component;
(2) an amount within the range from about 0.1 to about 15%, preferably from about 0.3 to about 8%, by weight of the surface-active component; and
(3) an amount within the range from about 0.1 to about 4%, preferably from about 0.3 to about 2%, by weight of water.
The process of the invention is applicable to any triglyceride, but particularly to the triglycerides in naturally-occurring fats and oils, either in the form of the naturally occurring fat or oil, or in a fraction or derivative thereof, such as a distillation product or hydrogenation product thereof. Exemplary fats and oils to which the process can be applied include lard, tallow, palm oil, coconut oil, cottonseed oil, safflower seed oil, tung oil, sunflower seed oil, fish oil, rapeseed oil, whale oil, sperm oil, oiticica oil, palm kernel oil, olive oil, corn oil, and soybean oil.
The transesterification can be effected with any fatty acid, but is normally with a fatty acid derived from a naturally-occurring fat or oil. The fatty acid can be any aliphatic saturated or unsaturated fatty acid having from about six to about twenty four carbon atoms, including capric acid, caprylic acid, caproic acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, ricinoleic acid, erucic acid, and behenic acid. Mixtures of acids can be used.
The following Examples represent preferred embodiments of the process of the invention:
Example 1
An enzymatic transesterification of palm oil triglyceride with stearic acid was carried out in a microemulsion having the following composition, in % by weight:
______________________________________2.7% Triethylene glycol ether of dodecyl alcohol96.2% Technical nonane1.1% Water in the form of sodium hydrogen phosphate buffer (pH 8)______________________________________
The amount of palm oil/stearic acid (weight ratio 2:1) was 5.3 grams per 100 grams microemulsion. The enzyme was Rhizopus delemar, in an amount of 34 mg per 100 g of microemulsion.
The reaction was carried out at 35° C., with stirring. The microemulsion was mixed with the Rhizopus delemar, and then heating begun to bring the temperature to 35° C. The reaction was continued for 48 hours at 35° C., with samples being taken after 4, 8, 24 and 48 hours. The triglyceride was analyzed chromatographically in respect to the fatty acid composition.
The reaction, as shown in Table I below, progressively replaces with stearic acid the palmitic acid and the oleic acid in the palm oil. The transesterification reaction has effectively reached completion after about four hours, since there is very little change in composition thereafter.
TABLE I______________________________________Reaction time Fatty acid composition of the triglyceride (%)(hours) Stearic acid Palmitic acid Oleic acid______________________________________0 5.4 48.7 45.94 27.8 32.1 40.18 27.0 33.2 39.824 31.1 34.9 34.048 31.2 35.4 33.4______________________________________
In comparison, the same transesterification was carried out in accordance with the prior art, transesterifying palm oil with stearic acid in hexane as a solvent. The composition of the reaction mixture was as follows, per 100 g microemulsion:
______________________________________5 g palm oil/stearic acid 2:10.3 g Celite94.6 g Technical nonane0.1 g Water in the form of sodium hydrogen phosphate buffer (pH 7)34 mg Rhizopus delemar______________________________________
The components were mixed, and the reaction mixture brought to 35° C. with stirring, and continued at 35° C. for 48 hours. Samples were taken after 4, 8, 24 and 48 hours. The triglyceride was subjected to chromatographic analysis, and the fatty acid composition determined, with the results shown in Table II below.
TABLE II______________________________________Reaction time Fatty acid composition of the triglyceride (%)(hours) Stearic acid Palmitic acid Oleic acid______________________________________0 5.4 48.7 45.94 7.5 49.2 43.38 17.2 42.8 40.024 22.4 40.7 36.948 32.6 31.2 36.2______________________________________
It is apparent from the results in Table II that a reaction time of about 40 hours is required to bring the reaction to completion, about 10 times longer than in the process according to the invention.
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A process is provided for the rapid transesterification of triglycerides with fatty acids in the presence of lipase enzyme, using an aqueous microemulsion reaction medium comprising a hydrophobic component, a surface-active component, and water.
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CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority from Taiwan Patent Application No. 103135381, filed on Oct. 13, 2014, in the Taiwan Intellectual Property Office, the contents of which are hereby incorporated by reference in their entirety for all purposes.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The disclosure relates to a preparation method of carboxylic acids or ketones using ozone, singlet state-oxygen atom or hydroxyl free radical, and more particularly, to a preparation method of carboxylic acids or ketones using ozone in the dark or under uv light irradiation.
2. Description of the Related Art
As far as plastic industry is concerned, adipic acid and terephthalic acid have been playing critical roles. Adipic acid is a precursor for preparation of nylon; and terephthalic acid can be used to prepare polyethylene terephthalate (PET). In the food processing industry, benzoic acid is served as an additive. Methods for mass production of adipic acid, terephthalic acid and benzoic acid in the current industry are, respectively, to oxidize cyclohexane, p-xylene, and toluene at high temperature and high pressure; and the details can be, respectively, referred to parts (a), (b) and (c) in the Reaction 1.
As shown in part (a) of the Reaction 1, the preparation of adipic acid is by oxidizing cyclohexane using oxygen at a temperature of higher than 125° C. and at a high pressure in the range of 8 to 15 atm in the presence of catalysts, such as, cobalt and manganese, to produce cyclohexanone and cyclohexanol (the so-called “KA” oil), followed by nitric acid (50% to 65%) oxidation to produce adipic acid at temperatures in the range of 70˜90° C. By means of the aforementioned method, the conversion and selectivity are good, though, a side product, N 2 O, is produced. N 2 O not only can cause global warming, but also can destruct the ozone layer. Production of 1 kg adipic acid is accompanied with the formation of 0.3 kg of N 2 O. It is troublesome and energy-consuming to recycle N 2 O gas, and to avoid direct release to the atmosphere. In addition, the harsh condition of high temperature and high pressure for the Reaction 1 is highly energy-demanding. Moreover, the use of corrosive nitric acid can only be done in expensive titanium reaction vessels, and the operation thereof may be dangerous to the personnel, who is running the reaction.
As shown in the part (b) of the Reaction 1, preparation of terephthalic acid is by oxidizing p-xylene with oxygen at a high temperature of 200° C. and a high pressure of 8 to 15 atm using catalysts, such as, cobalt and manganese along with bromide ions in acetic acid; and the reaction is progressed by multiple steps to produce terephthalic acid. The preparation of terephthalic acid has good conversion and good selectivity. Owing to the high temperature and high pressure, the industrial terephthalic acid production process is also high energy demanding (and thus high production cost). In addition, both bromide ions and acetic acid are corrosive at high temperatures. The primary impurity, 4-carboxybenzaldehyde (4-CBA), is an inhibitor in the latter polyethylene terephthalate (PET) polymerization process, and has to be removed from the terephthalic acid product. Part (c) of the Reaction 1 is akin to the part (b). The preparation of benzoic acid is to oxidize toluene using oxygen (air) at a high temperature and a high pressure in the presence of catalysts, such as, cobalt and manganese along with bromide ions in acetic acid. Consequently, it is also high energy demanding and environmentally unfriendly.
Inasmuch as the preceding technical problems, the scientific community has been seeking for alternatives. In 1994, the preparation of adipic acid by enzymatic catalysis of glucose was reported, and details can be referred to the Reaction 2 below:
As shown in the Reaction 2, the conversion of glucose to adipic acid was achieved in a biochemistry system (enzymes and reagents are not shown), and the yield is up to 97%. Mass production of adipic acid by the above enzymatic process requires the use of million tons of enzymes, which are not commercial available. This method does not comply with efficiency of manufacturing cost. As a result, this enzymatic reaction is still not able to replace the current industrial production of adipic acid.
In addition, another alternative “green” reaction was reported for the preparation of adipic acid via catalytic oxidation of cyclohexene using hydrogen peroxide (H 2 O 2 ) as an oxidant. The details can be referred to the following Reaction 3.
As shown in the Reaction 3, only H 2 O 2 and water are involved in the reaction, and manufacturing process thereof is very simple and environmentally friendly. However, this cyclohexene-H 2 O 2 process was not industrialized, since the cost of H 2 O 2 is higher than the value of adipic acid produced. Overall, 4-4.4 equivalents of H 2 O 2 was required for production of 1 mole of adipic acid. The price of H 2 O 2 is ˜55% of adipic acid, and thus for the entire reaction, the cost of H 2 O 2 is ˜2.2 times the value of the adipic acid product. Thus, it is economically infeasible. Moreover, cyclohexene is more expensive than cyclohexane. As a result, the reaction is void of industrial applicability.
Because the quantity of the global demand of the adipic acid is ˜3.9 million tons/year in 2014, which is equivalent to a market value of about US$ 6.2 billion. In the case of terephthalic acid, the quantity of worldwide annual production is ˜44 million tons/year in 2014, which is equivalent to a market value of about US$ 44 billion. In the case of benzoic acid, the quantity of worldwide annual production is ˜0.7 million tons/year, which is equivalent to a market value of ˜US$ 1.1 billion. Overall, the total market value of adipic acid, terephthalic acid and benzoic acid is about ˜51.3 billion USD. Hence, if there is a method being able to improve the preceding problems of the three synthesis methods using the same reaction mechanism, it will benefit the industry a lot and reduce the manufacturing cost greatly at the same time.
SUMMARY OF THE INVENTION
Inasmuch as the aforementioned problems, the purpose of the present invention is to provide a method of preparing carboxylic acids or phenyl ketones using ozone, singlet state-oxygen atom O( 1 D) or hydroxyl free radical to resolve the technical problems and high pollution problems involved in the conventional art concerning the harsh conditions, such as, high temperature, high pressure and highly corrosive reaction mediums, required for industrial production of adipic acid, terephthalic acid and benzoic acid.
In accordance with one purpose of the present invention, it provides a method to prepare ketones, which may include steps of: filling at least one of following three oxidants, including ozone, a singlet state-oxygen atom O( 1 D), and a hydroxyl free radical to cycloalkanes at a pre-determined temperature and a pre-determined pressure without using transition metal catalysts or bromide catalysts and without using nitric acid or acetic acid as solvent to produce cycloketones; wherein the pre-determined temperature may be in a range between −10° C. and 50° C., and the pre-determined pressure may be in a range between 0.8 atm and 1.2 atm; wherein the cycloalkanes may comprise cyclopentane, cyclohexane, cycloheptane, cyclooctane or a combination thereof; the cycloketones may comprise cyclopentanone, cyclohexanone, cycloheptanone, cyclooctanone or a combination thereof.
Preferably, the singlet state-oxygen atom O( 1 D) may be produced by irradiation of ozone by a light beam having a wavelength between 230 nm and 330 nm.
Preferably, the hydroxyl free radical may be produced by reaction of ozone with water, by reaction of a singlet state-oxygen atom O( 1 D) with water, by reaction of hydrogen peroxide with ferrous ions, or by reaction of hydrogen peroxide with cuprous ions.
In accordance with another purpose of the present invention, it provides a method to prepare carboxylic acids, which may include steps of: filling at least one of following three oxidants, including ozone, a singlet state-oxygen atom O( 1 D), and a hydroxyl free radical to the cycloketones prepared by the method of claim 1 at a second pre-determined temperature and a second pre-determined pressure without using transition metal catalysts or bromide catalysts and without using nitric acid or acetic acid as a solvent to produce aliphatic dicarboxylic acids; wherein the aliphatic dicarboxylic acids may comprise glutaric acid, adipic acid, pimelic acid, suberic acid or a combination thereof.
Preferably, the second pre-determined temperature may be in a range between −10° C. and 50° C., and the second pre-determined pressure may be in a range between 0.8 atm and 1.2 atm; the method may further include a step of adding a co-solvent, and the co-solvent may include at least one component from aluminum oxide, acetonitrile and water.
In accordance with one more purpose of the present invention, it provides a method to prepare aromatic ketones which may include steps of: filling at least one of following three oxidants, including ozone, a singlet state-oxygen atom O( 1 D), and a hydroxyl free radical to alkylbenzenes at a pre-determined temperature and a pre-determined pressure without using transition metal catalysts or bromide catalysts and without using nitric acid or acetic acid as a solvent to produce aromatic ketones, wherein an alkyl group of the alkylbenzenes comprises two or more carbon atoms; wherein the alkylbenzenes may include ethyl benzene or diphenylmethane, and the aromatic ketones may include acetophenone or benzophenone.
Preferably, the pre-determined temperature may be in a range between −10° C. and 50° C., and the pre-determined pressure may be in a range between 0.8 atm and 1.2 atm.
Preferably, the singlet state-oxygen atom O( 1 D) may be produced by irradiation of ozone by a light beam having a wavelength between 230 nm and 330 nm.
Preferably, the hydroxyl free radical may be produced by reaction of ozone with water, by reaction of a singlet state-oxygen atom O( 1 D) with water, by reaction of hydrogen peroxide with ferrous ions, or by reaction of hydrogen peroxide with cuprous ions.
In accordance with another purpose of the present invention, it further provides a method to prepare aromatic carboxylic acids, which may include steps of: filling at least one of following three oxidants, including ozone, a singlet state-oxygen atom O( 1 D), and a hydroxyl free radical to benzenes at a pre-determined temperature and a pre-determined pressure without using transition metal catalysts or bromide catalysts and without using nitric acid or acetic acid as solvent to produce aromatic carboxylic acids, wherein the number of carbon atoms of each substituent of the benzenes is 1; wherein the benzenes may comprise toluene, p-xylene, o-xylene, m-xylene, p-toluic acid, 4-carboxybenzaldehyde or a combination thereof; and the aromatic carboxylic acids may comprise benzoic acid, terephthalic acid, phthalic acid, isophthalic acid or a combination thereof.
Preferably, the pre-determined temperature may be in a range between −10° C. and 50° C., and the pre-determined pressure may be in a range between 0.8 atm and 1.2 atm; the method may further comprise a step of adding a co-solvent; and the co-solvent comprises at least one of aluminum oxide, acetonitrile and water.
Preferably, the singlet state-oxygen atom O( 1 D) may be produced via irradiation of ozone molecules by a light beam having a wavelength between 230 nm and 330 nm.
Preferably, the hydroxyl free radical may be produced by reaction of ozone with water, by reaction of a singlet state-oxygen atom with water, by reaction of hydrogen peroxide with ferrous ions, or by reaction of hydrogen peroxide with cuprous ions.
According to the preceding descriptions, a method to prepare carboxylic acids or aromatic ketones using ozone, singlet state-oxygen atom or hydroxyl free radical in accordance with the present invention may have one or more advantages as follows:
(1) By means of the method, irradiated-ozone, singlet state-oxygen atom or hydroxyl free radical may be able to react with various kinds of substrates in a closed reactor without limitations of high temperature and pressure and the use of corrosive nitric acid. In addition, production of toxic N 2 O can therefore be avoided. As a result, the goals of energy-saving, environmental protection and cost reduction can be accomplished.
(2) By means of the method, ozone may be able to react with various kinds of substrates in normal temperature and pressure in a closed reactor without irradiation, and the process is a simple and convenient manufacturing method.
BRIEF DESCRIPTION OF THE DRAWINGS
The sole FIGURE is a flow chart of a preparation method of carboxylic acids using ozone in accordance with Embodiment 1 of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The exemplary embodiments of the present invention will be understood more fully from the detailed description given below and from the accompanying drawings of various embodiments of the invention, which, however, should not be taken to limit the invention to the specific embodiments, but are for explanation and understanding only.
Please refer to the FIGURE, which is a flow chart of the current method to prepare carboxylic acids using ozone in accordance with Embodiment 1 of the present invention. As shown in the FIGURE, a preparation method of carboxylic acids using ozone according to the present invention may include steps of: filling ozone to cycloalkanes or benzenes at a pre-determined temperature and a pre-determined pressure (step S 1 ) to produce aliphatic-dicarboxylic acids or aromatic carboxylic acids (step S 2 ); wherein the cycloalkanes may be selected from the group consisting of cyclopentane, cyclohexane, cycloheptane and cyclooctane, the benzenes may be selected from the group consisting of toluene, p-xylene, o-xylene, m-xylene, p-toluic acid and 4-carboxybenzaldehyde; the aliphatic dicarboxylic acids may be selected from the group consisting of glutaric acid, adipic acid, pimelic acid and suberic acid, and the aromatic carboxylic acids may be selected from the group consisting of benzoic acid, terephthalic acid, phthalic acid and isophthalic acid; and wherein the pre-determined temperature may be in a range between −10° C. and 50° C., and the pre-determined pressure may be in a range between 0.8 atm and 1.2 atm. The reaction can be represented in the following Reaction 4 and Reaction 5.
In Embodiment 1, the method further includes a step of adding a co-solvent while p-xylene, o-xylene or m-xylene reacts with ozone; and wherein the co-solvent may include at least one component from aluminum oxide, acetonitrile or water.
In accordance with Embodiment 2 of the present invention, firstly, neat cyclohexane is filled in a glass tube and 20 v/v % of water is added at (dry condition is also allowable) 25° C. and 1 atm, and the opening of the reaction vessel is covered by a lid. Next, the glass tube is exposed to the irradiation from a 100 W Hg lamp, and a plastic pipe is inserted into the glass tube, and ozone is filled continuously through the plastic pipe for about 8 hours. White precipitate is produced gradually, and the crude product of adipic acid is remained in the glass tube when the Hg lamp irradiation stops. The crude product of adipic acid is dispersed in solvents such as ethyl acetate and hexane to become slurry. After shaking for a while, the white precipitate below is pure adipic acid, and conversion and selectivity thereof are 82% and 100%, respectively. Wherein, the conversion indicates a sum of yield of the product and derivatives thereof. The reaction mechanism in accordance with Embodiment 2 is shown in the following Reaction 6.
(i) The reaction of ozone with anhydrous cyclohexane under irradiation.
(ii) The reaction of ozone with hydrous cyclohexane under irradiation.
As shown in part (i) of the Reaction 6, when ozone is under irradiation by a 100 W Hg lamp, it produces singlet state-oxygen atom O( 1 D). When the O( 1 D) reacts with the liquid-phase cyclohexane, the O( 1 D) will insert into a C—H bond on the cyclohexane ring to form cyclohexanol; and this reaction is a spontaneous exothermal reaction. The same O( 1 D) insertion will occur selectively at the geminal C—H bond to the hydroxyl group to form a geminal diol, which will rapidly undergo dehydration to form cyclohexanone. Afterwards, O( 1 D) can further insert into the C—H bond on α carbon of cyclohexanone to form a ketone-hydroperoxide. An O—O bond of the ketone-hydroperoxide breaks, and the electron pair shifts to open ring to produce 6-al-hexanoic acid through the path a. Adipic acid is then formed via further ozone oxidization. The path b is another possible reaction pathway towards producing adipic acid. The reaction of the path b is firstly to form cyclohexanedione. Under the ozone-uv irradiation condition, cyclohexanedione was converted to glutaric acid, instead of adipic acid (see results in Table 1). Therefore, the path b doesn't happen under practical circumstance. It can be observed through what has discussed above that cyclohexanone and cyclohexenol are reversible enol-keto form tautomers. In path c, cyclohexenol can react with ozone in the dark to generate adipic acid.
In the presence of water, both ozone and singlet state-oxygen atom O( 1 D) can react with water to produce hydroxyl free radical (referring to part (ii) of Reaction 6); and the hydroxyl free radical can react with cyclohexane through a series of peroxidation to produce adipic acid. Here, the hydroxyl free radical may be produced by other reactions, such as, by reaction of H 2 O 2 with Fe 2+ or Cu + . As a result, the production of the hydroxyl free radical is not limited to the processes via reactions of ozone or singlet state-oxygen atom O( 1 D) with water.
Embodiments 3 to 5, in accordance with the present invention, are akin to the Embodiment 2, and the difference thereof only lies in that cyclopentane, cycloheptane and cyclooctane are, respectively, served reactants; and upon ozone-uv irradiation for 5 hours, these substrates were oxidized and converted to glutaric acid, pimelic acid and suberic acid with yields of 40%, 62% and 70%, respectively.
Please refer to the Reaction 4. The aforementioned Embodiments 2 to 5 all belong to the reaction shown in the Reaction 4. As shown in the Reaction 6 which shows the reaction mechanism of the Embodiment 2, there are many intermediates produced in the process, and these intermediates may also be able to react with singlet state-oxygen atom to produce aliphatic dicarboxylic acids. Therefore, Embodiments 6 to 8 in accordance with the present invention are akin to the Embodiment 2; and the difference thereof only lies in that cyclohexanol, cyclohexanone and cyclohexanedione are, respectively, served reactants; and they react with ozone under irradiation for 5, 5 and 1 hour, respectively, to produce adipic acid, adipic acid and glutaric acid, respectively.
For the sake of clarity, the related reaction conditions and results of Embodiments 2 to 8 in accordance with the present invention are summarized in the Table 1.
TABLE 1
Reaction Time
Yield
Selectivity
Reagent
Products
(Hour)
(%)
(%)
Embodiment 2
8
82
100
Embodiment 3
5
40
100
Embodiment 4
5
62
100
Embodiment 5
5
70
100
Embodiment 6
5
75
100
Embodiment 7
5
90
100
Embodiment 8
1
95
100
In accordance with the Embodiment 9 of the present invention, firstly, neat p-xylene is filled in a glass tube, and ozone gas flow is introduced to the glass tube for about 10 minutes. The reaction solution was exposed to 100 W Hg lamp light irradiation for about 15 hours. White precipitate is produced gradually. After light irradiation, solvents are added therein to wash away unreacted substrate from the solid precipitate; and the white solid precipitate was collected by either centrifugation or filtration. The white solid is composed of terephthalic acid and p-toluic acid; and the conversion was determined to be ˜80 mol %.-Embodiment 9 in accordance with the present invention is shown in the Reaction 5.
Please refer to the Reaction 5, the condition of the Embodiment 9 leads to formation of 20 mol % terephthalic acid and 60 mol % p-toluic acid. Because p-toluic acid does not dissolve in p-xylene and exists in the form of a solid, the poor contact of solid p-toluic acid forbids further oxidative conversion of p-toluic acid to terephthalic acid. Consequently, if increase in the yield of terephthalic acid is expected when a “better” solvent is used to help dissolution of p-toluic acid, which allows p-tuluic acid to be easily accessed by oxidants in the solution. As a result, Embodiments 10 in accordance with the present invention is akin to the Embodiment 9; and the difference thereof only lies in the process of reaction. 45 mol % of terephthalic acid and 45 mol % of p-Toluic acid are, respectively, produced after 10 hours of reaction. Hence, the yield of terephthalic acid is effectively enhanced.
Embodiment 11 in accordance with the present invention is akin to the Embodiment 9; and the difference thereof only lies in the fact that a co-solvent of xylene, acetonitrile and water (in 5:3:2 volume ratio) is used in the reaction, and the pH value is controlled to be ˜4.5. The co-solvent is a so-called “green solvent” which is composed of a mixture of several environmentally-friendly solvents; and the purpose of using the co-solvent is to dissolve the otherwise insoluble, reaction intermediate, such as, p-toluic acid, so that further oxidation of p-toluic acid can be proceeded and the yield of the desirable ultimate product, i.e., terephthalic acid, is increased. Hence, in the Embodiment 11 in accordance with the present invention, the p-toluic acid is re-dissolved by the co-solvent to allow further oxidation and the yield of terephthalic acid is effectively promoted up to 65%.
In the Embodiment 11 in accordance with the present invention, even though re-dissolving in the co-solvent of xylene, acetonitrile and water (in 5:3:2 volume ratio), the yield of p-toluic acid is 32%. In addition, another reaction intermediate, i.e., 4-carboxybenzaldehyde (4-CBA), may be detected by NMR spectrum. Hence, Embodiment 12 in accordance with the present invention is to treat 1 M p-toluic acid in an acetonitrile-water co-solvent (in a 2:1 volume ratio) with ozone-uv irradiation for 8 hours, and terephthalic acid is produced with a yield up to 95%. Embodiment 13 in accordance with the present invention is to treat 1 M 4-carboxybenzaldehyde in a acetonitrile-water (in a 2:1 volume ratio) co-solvent with ozone-uv irradiation for 5 hours; and terephthalic acid is produced with a yield up to 98%. As a result, in Embodiment 11, ozone-uv irradiation of a p-xylene-acetonitrile-water (in 5:3:2 volume ratio) solution leads to formation of terephthalic acid with a higher yield of 65%.
Embodiment 14 in accordance with the present invention is to prepare phthalic acid by ozonolysis-uv irradiation of o-xylene; and the reaction thereof is akin to the Embodiment 9. The reaction solution is composed of o-xylene, acetonitrile and water in a 5:3:2 volume ratio with a pH value of ˜4.5. The uv light irradiation time is about 20 hours, which leads to formation of 45 mol % phthalic acid and 50 mol % o-toluic acid. The Embodiment 15 is akin to the Embodiment 14, and the difference thereof only lies in that the m-xylene is used as a substrate, where 53 mol % isophthalic acid and 42 mol % m-toluic acid were formed.
The Embodiment 16 in accordance with the present invention is to prepare benzoic acid by ozone-uv irradiation of neat toluene without adding co-solvent, and reaction thereof is akin to the Embodiment 9. After 8 hours of ozone-uv irradiation, 55 mol % of benzoic acid and 5 mol % of benzaldehyde were produced.
For the sake of clarity, the related reaction conditions and results of the Embodiments 9 to 16 in accordance with the present invention are summarized in the following Table 2.
TABLE 2
Reaction
Products
By-products
Time
Selectivity
Reagent
Solvent
(Yield, %)
(Yield, %)
(Hour)
(%)
Embodiment 9
—
15
80
Embodiment 10
γ Al 2 O 3 (25 wt %)
10
95
Embodiment 11
p-Xylene: acetonitrile: Water = 5:3:2 (pH = 4.5)
20
97
Embodiment 12
Acetonitrile: Water = 2:1 (1M)
—
8
95
Embodiment 13
Acetonitrile: Water = 2:1 (1M)
—
5
98
Embodiment 14
o-xylene: Acetonitrile: Water = 5:3:2 (pH = 4.5)
20
95
Embodiment 15
m-Xylene: Acetonitrile: Water = 5:3:2 (pH = 4.5)
20
96
Embodiment 16
—
8
60
In summary, preparation of carboxylic acids by ozone-uv irradiation in accordance with the present invention is expected to greatly reduce the production cost of adipic acid and terephthalic acid; and this method is economically feasible. The present invention is also applicable for preparation of aromatic ketones, albeit their total worldwide annual capacities are not as large as those for adipic acid and terephthalic acid. Aromatic ketones are important intermediates for synthesis of various medicinal molecules used in the pharmaceutical industry; and aromatic ketones are of high prices, thus aromatic ketone absolutely has its applied values. Therefore, the Embodiment 17 in accordance with the present invention is to produce acetophenone with a yield of 75% by ozone treatment and concurrent uv irradiation of neat ethylbenzene. The embodiment 18 is to produce benzophenone with yield of 80% by ozone treatment and concurrent uv irradiation of neat diphenylmethane. The related reaction conditions and results of Embodiments 17 and 18 in accordance with the present invention are summarized in the following Table 3.
TABLE 3
Reaction Time
Yield
Selectivity
Reagent
Products
(Hour)
(%)
(%)
Embodiment 17
8
75
75
Embodiment 18
8
80
80
The present invention is mainly to prepare singlet state-oxygen atom O( 1 D) by ozone under irradiation, and singlet state-oxygen atom may also be produced by the other gases such as N 2 O upon irradiation. However, the singlet state-oxygen atom O( 1 D) produced by irradiation of N 2 O has short presence duration and may become triplet state-oxygen atom O( 3 P) soon, so the singlet state-oxygen atom produced by irradiation of N 2 O is not be able to carry out the reaction efficiently in accordance with the present invention. Therefore, if the presence duration for singlet state-oxygen atom O( 1 D) used to carry out the reaction is sufficient, the singlet state-oxygen atom can be prepared by any other gases and is not limited to ozone.
On the other hand, the present invention may also only use ozone and substrates to carry out the reaction without additional irradiation, but yield thereof is lower (as compared to the photo-irradiated reaction). The mechanism of the dark reaction is also not the same as that of the photo-irradiated reaction. The mechanism of the dark reaction mainly involves that ozone abstracts a hydrogen atom directly from substrates to produce HOOO. and alkyl (R.) free radicals. The alkyl free radical can further react with molecular oxygen to proceed through a peroxidation chain reaction to generate alkyl hydroperoxide (ROOH). Consequently, the Embodiments 19 to 35 in accordance with the present invention are akin to the Embodiments 2 to 18 which are to use the same reactants, co-solvent; and the reaction time is the same, as well. The difference thereof only lies in that the former is the reaction carried out in the presence of ozone in the dark, and the related reaction conditions and yields of the Embodiments 19 to 35 in accordance with the present invention are summarized in the following Tables 4, 5 and 6.
TABLE 4
Yield
Selectivity
Reagent
Products
(%)
(%)
Embodiment 19
22
100
Embodiment 20
5
100
Embodiment 21
10
100
Embodiment 22
13
100
Embodiment 23
15
100
Embodiment 24
25
100
Embodiment 25
95
100
TABLE 5
Reaction
Products
By-products
Time
Selectivity
Reagent
Solvent
(Yield, %)
(Yield, %)
(Hour)
(%)
Embodiment 26
—
15
80
Embodiment 27
γ Al 2 O 3 (25 wt %)
10
95
Embodiment 28
p-Xylene: acetonitrile: Water = 5:3:2 (pH = 4.5)
20
97
Embodiment 29
Acetonitrile: Water = 2:1 (1M)
—
8
95
Embodiment 30
Acetonitrile: Water = 2:1 (1M)
—
5
98
Embodiment 31
o-xylene: Acetonitrile: Water = 5:3:2 (pH = 4.5)
20
95
Embodiment 32
m-Xylene: Acetonitrile: Water = 5:3:2 (pH = 4.5)
20
96
Embodiment 33
—
8
60
TABLE 6
Reaction Time
Yield
Selectivity
Reagent
Products
(Hour)
(%)
(%)
Embodiment 34
8
40
75
Embodiment 35
8
50
80
In conclusion, a method was invented for preparation of carboxylic acids or ketones using ozone, singlet state-oxygen atom or hydroxyl free radical in accordance with the present invention at normal temperature and pressure without producing global warming and ozone-depleting N 2 O gas. This method uses environmentally-friendly solvents, and thus, the method is an energy-saving, and environmentally-friendly process. Particularly, this method is applicable to prepare those important industrial key chemicals of great annual capacities, such as adipic acid, terephthalic acid, benzoic acid, acetophenone, and benzophenone, which are of higher price. As a result, the present invention is expected to be economically feasible in the industry.
While the means of specific embodiments in the present invention has been described by reference drawings, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope and the spirit of the invention set forth in the claims. The modifications and variations should not be limited by the specification of the present invention.
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A preparation method of carboxylic acids or ketones using ozone, singlet state oxygen atom O( 1 D) or hydroxyl free radical is provided. The method includes: filling ozone, singlet state oxygen atom O( 1 D) and/or hydroxyl free radical to cycloalkanes or benzenes at a pre-determined temperature and a pre-determined pressure in the presence or absence of light irradiation to produce carboxylic acids or ketones. The reaction occurs at room temperature and atmospheric pressure without producing harmful side products. The preparation method is a simple, low energy consuming, and eco-friendly method.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the fabrication of integrated circuit devices and more particularly to a method of fabricating high density dynamic random access memory (DRAM) devices and the like.
2. Description of the Prior Art
As DRAMs are scaled down in dimensions, there is a continuous challenge to maintain a sufficiently high stored charge per capacitor unit area. In order to construct high density DRAMs in a reasonable sized chip area, the cell structures have to change from the conventional planar-type capacitors to either trench capacitors or stack capacitors, in particular beyond the 4 Mbit DRAM era. All efforts to increase capacitance without increasing the planar area of the capacitor can be categorized into the following techniques:
(1) Thinning the capacitor dielectric and/or using films with a higher dielectric constant, such as oxide-nitride-oxide (ONO) films composite, and more recently tantalum pertoxide which will require further development to overcome leakage and reliability problems.
(2) Building three dimensional capacitor structures to increase the capacitor area without increasing the planar area of the capacitor. There are two major branches of this approach, that is trench capacitors and stacked capacitors. In the category of trench capacitors, when the DRAM is beyond 16 Mbit, the trench needs to be very deep. There are technology and even theoretical physical limitations to processing the deep trenches that would be needed. When the stacked capacitor approach is used to fabricate 16 Mbit DRAMs and beyond, very complicated stacked structures are needed, such as fin structures, crown structures, and so forth. The making of such structures require complicated manufacturing processes which are costly and result in reduced yield.
Most recently a new concept has been advanced which calls for roughening the polycrystalline silicon surface of the capacitor electrode to increase the surface area. Several techniques for achieving a roughened surface of a polycrystalline silicon electrode layer have been suggested in technical paper recently presented by M. Sakao et al entitled "A CAPACITOR-OVER-BIT-LINE (COB) CELL WITH A HEMISPHERICAL-GRAIN STORAGE NODE FOR 64 Mb DRAMs" in IEDM 1990 TECHNICAL DIGEST pages 655-658; M. Yoshimaru et al entitled "RUGGED SURFACE POLY-SI ELECTRODE AND LOW TEMPERATURE DEPOSITED SILICON NITRIDE FOR 64 MBIT AND BEYOND STC DRAM CELL" in IEDM 1990 TECHNICAL DIGEST pages 659-662; and Pierre C. Fazan et al entitled "ELECTRICAL CHARACTERIZATION OF TEXTURED INTERPOLY CAPACITORS FOR ADVANCED STACKED DRAMs" in IEDM 1990 TECHNICAL DIGEST pages 663-666.
SUMMARY OF THE INVENTION
A principal object of the invention is to provide an effective and very manufacturable method to fabricate a capacitor device having an increased effective electrode surface area and the resulting capacitor structure.
Another object of this invention is to provide an new method for producing a roughened surface on a polycrystalline silicon surface for use in highly dense capacitor structures.
Yet another object of this invention is to provide a new more reliable method for producing high density DRAM devices and the resulting structure which features a new stacked capacitor structure.
In accordance with these objects of this invention, a new method to produce a microminiturized capacitor having a roughened surface electrode is achieved. The method involves depositing a first polycrystalline silicon layer over a suitable insulating base. A thin layer of refractory metal is deposited over the first polysilicon layer. The resultant composite layer is heated to cause silicidation and growth of silicon grain crystals on the surface which thereby produces a roughened surface. The metal silicide is now removed. An insulating layer is deposited over the roughened surface. The capacitor structure is completed by depositing a second thin polycrystalline silicon layer over the insulating layer.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings forming a material par of this description, there is shown:
FIG. 1 is a schematic circuit diagram of a typical DRAM cell, which is known to the Prior Art.
FIGS. 2, 3 and 5 schematically illustrate in cross-sectional representation one preferred embodiment of this invention.
FIG. 4 schematically shows how the roughened surface is formed.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now more particularly to FIG. 1, there is shown an illustration of a single DRAM cell having a transistor 10, with gate electrode 12 electrically connected to a word line 14, and a capacitor 16 having a plate (ground plate) electrode 18 electrically connected to the ground, which could be for example the substrate, off chip, etc. and a electrode 20 (storage node) electrically connected to the drain region 22 of transistor 10.
Referring now to FIG. 2, there is illustrated a partially completed DRAM structure upon which the new capacitor structure of the invention will be fabricated. The first series of steps involve the formation of the dielectric isolation regions for isolating semiconductor surface regions from other such regions in the semiconductor substrate 30. The semiconductor substrate is preferably composed of silicon having a (100) crystallographic orientation. In an effort to simplify the description and the drawings the dielectric isolation between devices has been only partially shown and will not be described in detail, because they are conventional. For example, one method is described by E. Kooi in his U.S. Pat. No. 3,970,486 wherein certain selected surface portions of a silicon semiconductor substrate is masked against oxidation, and then the exposed unmasked surface is oxidized to grow a thermal oxide which in effect sinks into the silicon surface at the unmasked areas. The masked silicon remains as a mesa surrounded by the sunken silicon dioxide or Field OXide pattern, FOX 28. Then semiconductor devices can be provided in the silicon mesas according to the following processes.
The surface of the silicon substrate 30 is thermally oxidized to form the desired gate oxide 11 thickness. The preferred thickness is between about 80 to 200 Angstroms. The polysilicon layer 12 is blanket deposited by LPCVD (Low Pressure Chemical Vapor Deposition) method. The preferred thickness of the polysilicon layer 12 is between about 2000 to 4000 Angstroms. The polysilicon layer 12 is ion implanted with phosphorous or arsenic ions under the conditions 5 to 10 E 15 dosage per cm 2 and 20 to 60 Kev. or doped with phosphorus oxychloride at a temperature about 900° C. The surface of the layer is either thermally oxidized or a chemical vapor deposition process to form silicon oxide layer 13. The layers 11, 12 and 13 are patterned by conventional lithography and anisotropic etching techniques as are conventional in the art to provide a desired pattern of gate electrodes and structure on the FOX 28 surfaces or elsewhere as seen in FIG. 2.
The source/drain structure of the MOS FET may now be formed by the following steps. The FIG. 2 illustrates the formation of an N channel FET integrated circuit device. However, it is well understood by those skilled in the art that a P channel FET integrated circuit device could also be formed by simply substituting opposite polarities to those given for the N channel embodiment. Also, a CMOS FET could in a similar way be formed by making both N channel and P channel devices upon the same substrate.
FIG. 2, for example shows the ion implantations of N- dopants. Lithographic masks may be required to protect the areas not to be subjected to that particular N- ion implantation. The formation of the lithographic masks are done by conventional lithography and etching techniques. The N- lightly doped drain implantation 23 and 25 are done with, for example phosphorous P31 at a dose of between about 1 to 10 E 13 atoms/cm. 2 and with an energy of between about 20 to 40 Kev.
The dielectric spacer 27 is now to be formed followed by the completion of the lightly doped drain source/drain structures. A low temperature silicon oxide deposition is preferred such as through the chemical vapor deposition of tetraethoxysilane (TEOS) at a temperature in the range of between about 650° to 900° C. Other silicon oxide deposition methods include silane based LPCVD. The thickness of the dielectric silicon dioxide layer 27 is between about 2000 to 5000 Angstroms and preferably about 2500 Angstroms.
An anisotropic etching of this layer produces the dielectric spacer layer 27 on the sidewalls of the layer structures 11, 12, 13. The preferred anisotropic etching uses a conventional reactive ion etching ambient.
A thin silicon oxide, silicon nitride or the like masking layer 29 is formed upon the layer structure regions 11, 12, 13; the spacers 27 and the exposed monocrystalline silicon substrate regions. The conditions for forming this layer 29 are LPCVD deposition of TEOS or LPCVD silicon nitride deposition at about 600° to 900° C. or a composite layer of silicon oxide and nitride. The preferred thickness of this dielectric layer is between about 200 to 1000 Angstroms and a preferred thickness of about 600 Angstroms.
The N+ source/drain ion implantation uses Arsenic, As75 with a dose of between about 2 E 15 to 1 E 16 atoms/cm. 2 and energy of between about 20 to 70 Kev. to complete the source/drain regions 22 of the N channel lightly doped drain MOS FET integrated circuit device as seen in the FIG. 2. The layer 29 is removed from the surface of the DRAM active drain areas as shown in FIG. 2 to form the capacitor node contact area.
Referring now to FIG. 3, the capacitor structure is fabricated by depositing a first polycrystalline silicon layer 32 over the surface of the substrate 30 using the same deposition techniques described in regard to polycrystalline silicon layer 12. The thickness of the first layer is typically between about 3000 to 6000 Angstroms. An impurity is introduced into the first layer, either by ion implantation techniques or in situ doping. The impurity concentration in this first layer 32 is preferably between about 10 18 to 10 21 per cm. 3 . A thin layer (not shown) of a refractory metal is now deposited over the surface of the first polycrystalline layer. The thin layer preferably has a thickness in the range of about 400 to 2000 Angstroms and is deposited by a suitable and conventional sputtering or evaporation method. The metals suitable for the thin refractory metal layer are titanium, cobalt, tungsten, platinum, etc. We will describe titanium as our preferred metal as our example hereinafter.
The composite polycrystalline and metal layer are heated to cause a metal silicide 33 to form in the surface of the first polycrystalline layer and cause the formation of silicon grain crystals on the surface. Because the metal film will react preferentially with the grain boundaries of the polycrystalline silicon under certain conditions, the uneven reaction rates of silicon grains and grain boundaries cause the roughened surfaces. FIG. 4 schematically shows this reaction effect wherein indentations at grain boundaries which reach the surface are the cause of the roughened surface. This effect is very unfavored in the common applications of the metal silicidations, but is favored in this particular application. The roughened surface is indicated by numeral 34.
An important feature of the process is that an excellent electrical contact is formed at the interface 36 between the source/drain 22 and the layer 32. The interface is indicated in FIG. 1 between electrode 20 and drain 22. Layer 32 is the eletrode 20 is FIG. 1. The contact resistance of the interface 36 between the polycrystalline silicon layer 32 and the drain of the access transistor 10 should be very low, and the resistance should be consistent batch to batch, between wafers in a single batch, and uniform across a single wafer in a batch. Maintaining an absolute highly clean interface during is difficult, because contamination of the substrate surface is difficult to avoid. Impurities present during processing, and the formation of native silicon oxide are the chief sources of contamination. However, in this process during the heating step, impurities at the interface are sucked toward the metal silicide layer. This gettering effect of the silicidation not only largely improves the consistency and uniformity, but also reduces the contact resistance and therefore speeds up the DRAM chip operation. The polycrystalline silicon grains will grow large, and the silicidation will take place preferentially along the polcrystalline silicon grain boundaries. The annealing temperature and time of annealing will vary depending upon the relationship. However, typically the annealing temperature will be in the range of about 500° to 1000° C., and the annealing time will be in the range of about 10 to 180 minutes in a conventional furnace with either argon or nitrogen ambient. Rapid thermal annealing can also be used, in this case 30 seconds to several minutes can be used. The temperature and time, of course will vary with the choice of metal. For titanium, 600° to 800° C. can be used. In the rapid thermal annealing case, about 60 to 120 seconds are operative in a nitrogen ambient.
Now the metal silicide 33 is removed, preferably with a clean etching solution, for titanium silicide such as hydrofluoric acid or buffered hydrofluoric acid. The metal silicide 33 can be easily striped from the roughened surface as seen in FIG. 4. Following the removal of the metal silicide, the roughed polysilicon layer is patterned, using conventional lithography and etching techniques.
Then a thin dielectric layer 38 is deposited. This layer serves as the capacitor dielectric. The thin dielectric or insulating layer has a thickness that is preferably in the range of about 30 to 250 Angstroms. The material of the dielectric layer can be of any suitable material having a high dielectric constant, and which forms a continuous, pinhole free layer. Preferably the dielectric layer is a composite layer of a silicon oxide-silicon nitride-silicon oxide with a total thickness of between about 40 to 150 Angstroms. Alternatively, and of particular importance for the future is the dielectric tantalum oxide, such as tantalum pentoxide or in combination with silicon dioxide and/or silicon nitride.
The preferred thickness of tantalum oxide or tantalum pentoxide is between about 150 Angstroms to 1000 Angstroms. The materials are of particular importance, because of their high dielectric constant and the well understood relationship between capacitance, C, dielectric constant, E, and thickness of dielectric, d, which is C=E/d. The dielectric constant of silicon dioxide is 3.9, silicon nitride is 8.0 and tantalum pentoxide is 22.0. Therefore, the effective thickness of tantalum pentoxide is about 5 times thinner than silicon dioxide.
Tantalum oxide may be deposited by several well known methods including chemical vapor deposition as taught by, for example, M. Saitoh et al ELECTRICAL PROPERTIES OF THIN TA 2 O 5 FILMS GROWN BY CHEMICAL VAPOR DEPOSITION published at IEDM'86 pages 680-683; Y Numasawa et al TA 2 O 5 PLASMA TECHNOLOGY FOR DRAM STACKED CAPACITORS published at IDEM '89 pages 43-46; and by reactive sputtering deposition as shown by H. Shinriki et al OXIDIZED TA 2 O 5 /SI 3 N 4 DIELECTRIC FILMS FOR ULTIMATE STC DRAMS published in IEDM '86 pages 684-687.
As shown in FIG. 5, a second polycrystalline silicon layer 40 is deposited over layer 30 and patterned to serve as the second electrode 18 in FIG. 1. The second polycrystalline silicon layer is also doped with an impurity, preferably with a concentration in the range of about 10 18 to 10 21 cm 3 .
FIG. 5 shows the completion of the metal contacts to the monocrystalline silicon regions such as the bit line 26 contact to source regions 24. An insulating structure 45 may be composed of, for example, a layer of silicon dioxide and a much thicker layer of borophosphosilicate glass, phosphosilicate glass or similar insulating layer. The operational thicknesses of these layers are between about 1000 to 2000 Angstroms for the oxide layer and between about 2000 to 10,000 or more Angstroms for the glasseous layer. These layers are typically deposited by chemical vapor deposition in low pressure or atmospheric pressure, or in a plasma enhanced reactive chamber.
The contact windows or openings are now formed through the insulating layered structure to the source regions 24 or the like in the device regions. The opening are not shown to the other regions, because they are outside of the cross-section of FIG. 5. This process step is conventionally done by lithography and etching techniques which preferably use a reactive ion etching process that will anisotropically etch both components of the insulating layer structure 45. A typical reactive ion etching process using fluorine containing etching chemical species. These oxide/glass layers etching processes are well known to those in the art. The size of the contact window opening can be as small as limitation of the etching and lithography patterning capability.
A bit line metal or composite metal layer or polycide composite layer (such as tungsten polycide) 26 is deposited over the exposed device region 24 and the insulating layer structure 45 both above and on the sides of the opening. This layer may be deposited by, for example chemical vapor depostion or sputtering. The operational thickness is between about 2000 to 10,000 Angstroms and the preferred thickness is between about 5000 to 7000 Angstroms. The thickness of this layer 26 is dependant upon the height and profile of the contact hole. This metal layer may be aluminum, aluminum-silicon, aluminum-silicon-copper, polycide, conductively doped polysilicon, tungsten or the like. Alternatively, a barrier metal layer (not shown) can be used under this metal layer.
The effective capacitor area, due to the roughened surface of the electrode, increases the electrical capacitance, per unit planar area, of the capacitor by approximately 50%. This will make it possible ot fabricate DRAMs of 16 Mbit and 64 Mbit or beyond with a simple stacked capacitor as described by the invention herein where ONO dielectric is used. To otherwise produce a capacitor for 16 to 64 Mbit DRAMs would require a 3-D complicated capacitor structure using ONO. When using the present invention, 256 Mbit to 1 Gbit DRAMs are possible using tantalum oxide dielectric materials.
The process of the invention also results in an excellent cell contact. Further, the process is simple and effective.
While the invention has been particularly shown and described with reference to the preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made without departing from the spirit and scope of the invention.
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A method of fabricating a microminaturized capacitor having an electrode that is roughened to increase the effective area per unit area and resulting structure, particularly adapted for use in high density dynamic random access memory devices. The method involves depositing a conductive polycrystalline silicon layer. The depositing a metal such as a refractory metal over the polysilicon layer. The composite layer is heated to form a metal silicide and roughened polycrystalline silicon surface while the grains also grow large. The metal silicide is removed, leaving a roughened surface. The capacitor dielectric layer is deposited upon the roughened surface. The second conductive polycrystalline silicon layer is now formed upon said dielectric layer to complete the capacitor.
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This is a division of application Ser. No. 007,096, filed Jan. 29, 1979 now U.S. Pat. No. 4,234,648.
BACKGROUND OF THE INVENTION
This invention relates to novel resin impregnated fabrics which are both thermally and electrically conductive, and more specifically, to resin impregnated fabrics woven from aluminum coated glass fibers.
It is known to fabricate structural elements or parts from resin/fiber composite systems in which the fibers provide the mechanical strength and the resin serves as a matrix to maintain the fibers in alignment. The fiber material is often in the form of a fabric woven from yarn, ie. relatively loose strands of twisted or untwisted fibers. Typically the fibers may be made of glass, or other reinforcing materials having the desired characteristics. The fabric is then impregnated with a suitable resin, such as an epoxy, polyester, polyimide or polysulfone resin, to form what is known as prepreg material (prepreg) which, generally speaking, comprises flat sheets of fabric impregnated with uncured resin. Layers of prepreg are typically laminated and cured at an elevated temperature and pressure to form the desired article.
Prepreg may be used to fabricate molded parts, as well as flat sheets for use, for example, when making honeycomb sandwich materials. To form the finished product or part, the prepreg is laminated by applying heat and pressure to multiple overlaying layers of prepreg in a mold or a so-called "lay-up".
Prepreg materials wherein the fibers are made of glass are particularly well adapted for high strength/lightweight applications, for example, in the aircraft and aerospace industries. In such a composite the material acts as reinforcement adding mechanical strength.
For many applications present prepreg laminate materials are unsuitable because of their poor electrical conductivity, i.e. high dielectric characteristics. For example, in the field of structural materials, it is well known that plastic surfaces are subjected to a build-up of static electricity. The usual solution is to coat the surface with a conductive paint. Similarly, electronic instruments require EMI shielding. Because of the dielectric characteristics of prepregs, metals or other electrically conductive materials are presently used for such casings. Also, to render plastic surfaces reflective, as is required for dish-antennae, for example, the surfaces must be flame sprayed with aluminum or a similar material if the dish-antennae are constructed of prepreg.
Thus, as a result of their lack of thermal or electric conductivity, plastic materials in general and prepregs in particular are either unusable for certain applications or they require a special treatment of their surfaces, normally the application of a separate coating. Where the electric and thermal characteristics of prepreg prevent its use altogether, an otherwise advantageous, e.g. inexpensive and readily worked, material is lost. Where the prepreg material requires the application of surface coatings and the like to give it the required conductivity, the cost of the finished product is increased. More importantly, surface coatings require periodic maintenance and/or replacement which adds to the cost of using such products and, unless conscientiously performed, may render the products inoperative until the surface coating has been repaired or replaced. Further, the additional weight of a conductive surface coating can be a significant disadvantage, e.g. in the aerospace industry. As a result, other materials, primarily metals, continue to be extensively used for applications where plastic materials and in particular prepregs could be advantageously employed from a structural point of view.
Thermal conductivity is applicable to better permit heat transfer, e.g. during heat molding operations. Thermal conductivity may also be applicable for heat dissipation, for example in electrical circuitry.
Accordingly it would be desirable to have a prepreg material which could be structurally utilized and which has the necessary electric and thermal conductivity so that it can be employed for the dissipation of static electricity for EMI shielding, as a lightning strike protection, for reflective surfaces, etc.
SUMMARY OF THE INVENTION
The present invention allows for the above summarized advantageous use of prepreg materials, in that it provides a prepreg material which has both good thermal conductivity and good electrical conductivity. More particularly, the present invention provides a prepreg material which includes a fabric woven from a multiplicity of fibers constructed of a dielectric material, e.g. glass, at least some of which have been at least partially coated with an electrically conductive material, e.g. a metal such as aluminum, and an uncured resin carried by the fabric. Prepreg materials of the present invention are light-weight structural materials which are a relatively inexpensive and easy to use substitute for metal sheets, or conventional prepregs coated with reflective or conductive paint and the like. For example, prepreg materials of the present invention can be substituted for conductive paint to render the surface of conventional prepregs conductive without adding weight by forming at least the outer ply of aluminum coated fabric.
Prepreg materials of the present invention are woven from continuous yarns which are bundles of dielectric fibers at least some of which have been at least partially coated with an electrically conductive material, such as a metal, typically aluminum. Depending on the characteristics desired in the prepreg there may be incorporated into the yarns other fibers, such as uncoated glass fibers. Normally, it is necessary to twist the continuous yarns about themselves prior to weaving to permit them to be handled during the weaving operation. Similarly, depending on the desired characteristics, continuous yarns comprising metal coated fibers may be woven in one or both directions, i.e. as either or both the fill and the warp of the fabric, to thereby impart to the prepreg a directionalized electric or thermal conductivity.
Prepreg material constructed in accordance with the present invention generally exhibits all the mechanical characteristics of conventional prepreg materials. In addition, it has electric and thermal conductivity to permit its use for a wide range of applications for which conventional prepregs were considered either unsuited or required special treatment.
Thus, the prepreg material of the present invention can be employed for the dissipation of static electricity which may accumulate on the surface of an article by constructing at least the outermost prepreg layer of a fabric woven from aluminum coated glass fibers. The prepreg of the present invention can further be utilized to provide reliable EMI shielding for electronic instruments to replace the heretofore common metal shielding. The shielding afforded by the prepreg of the present invention substantially enhances the manufacture of such shielding because prepreg is easier and less expensive to form than metals presently in use and further because the prepreg has a wider design range than metal. The prepreg material of the present invention can further be used as a structural prepreg to replace structural aluminum mesh screens for certain lightning strike applications, particularly on aircraft skins. Further, because of the firm bond between the glass fibers and the metal coating applied thereto, the prepreg functions as a built-in heat sink for the electrically conductive metal coating which greatly enhances the current that can be carried by it, particularly if the current is applied for relatively short durations.
Thus, the present invention makes it feasible to convert an otherwise dielectric prepreg material into an electrically and thermally conductive material by precoating the fibers which are then woven into a fabric for the prepreg. Consequently, the prepreg can be rendered electrically conductive without mixing metal strands, metal spheres and the like into the resin as was heretofore sometimes attempted and which adversely affects the structural integrity of the prepreg.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a flow diagram which schematically illustrates the method of forming articles from resin impregnated fabrics made of aluminum coated glass fibers in accordance with the present invention;
FIGS. 2A and 2B, respectively, are cross-sectional views of a glass fiber which is entirely and partially coated with aluminum.
FIG. 3 is a schematic side elevational view, in cross-section, of a prepreg material made in accordance with the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings and first to FIGS. 2A, 2B and 3, the present invention is particularly concerned with the manufacture of a prepreg material 2 that has a relatively high electric and thermal conductivity. The prepreg material is defined by a woven fabric 4 and uncured resin carried by the fabric and it is subsequently manufactured into a product or article in an essentially well-known manner. Briefly, a mold (not separately shown in the drawings) which has the desired shape of the finished article is prepared and one or more sheets of prepreg material, commonly referred to as "layers" or "plies", are placed over the mold. The prepreg plies are relatively limp and thus drape over and generally conform to the shape of the mold. In accordance with well-known techniques, the prepreg plies are then sufficiently heated to effect a curing of the resin and pressure, normally fluid pressure, is simultaneously applied so as to assure an exact conformity of the prepreg material to the mold and effect a cross-flow of resin between the plies to intimately bond the plies to each other and to thus structurally integrate them.
Conventional fabric used for the fabrication of prepreg material is made by weaving individual fibers, (untwisted) fiber bundles, or (twisted) fiber yarns in the desired pattern and density. A widely used fabric comprises glass fibers, such as E-glass fibers commercially available from the Hexcel Corporation of Dublin, Calif.
Such fabrics, the resulting prepreg material and the ultimate product exhibit poor electric and thermal conductivity since the fibers are usually constructed of a dielectric material. To render the fibers and therewith the prepreg and the product electrically conductive the present invention applies an electrically conductive, e.g. metal, coating such as an aluminum coating 8, 9 to the outer surface 10 of each fiber 6. Although the coating 9 may extend over the entire exterior surface 10 of the fibers (as shown in FIG. 2A), in the presently preferred embodiment of the invention the aluminum coating 8 extends over only a portion of the outer fiber surface 10, preferably over about one-half of the circumference of the surface (as shown in FIG. 2B) so that the aluminum coating effectively defines a troughshaped metallic shell 8 which has an inner diameter equal to the outer diameter of the fiber, which receives the fiber and which extends over the entire length of the fiber.
Although the fabrication of the fibers 6 per se does not form part of the present invention, and the aluminum coating 8, 9 can be applied in any desired manner so long as it firmly adheres to the surface of the fibers, it is preferred that the coating be applied by dipping continuous glass fibers in molten aluminum. In this manner the applied aluminum film is less uniform (as compared to a film applied by vapor deposition, for example), resulting in a non-uniform film thickness and a relatively uneven or irregular film surface. Such an uneven surface in turn establishes a better bond between the aluminum film and the resin of the prepreg than films having smooth surfaces. Metal-coated fibers constructed in this manner are available from MB Associates of San Ramon, Calif. under its trademark, Metafil G.
The coated fibers 20, 21 are preferably supplied in long, continuous lengths of up to several thousand yards to facilitate their subsequent weaving and to ensure a continuous electric conductor over the full length of the woven fabric. Further, the fibers are preferably half coated (see FIG. 2B) because of the better mechanical strength of the half coated fiber with no significant difference in electrical properties. Typically, the fibers of the present invention will be continuous, essentially endless fibers having diameters of from about 0.5 to 1.0 mil and an aluminum coating thickness of about 0.05 to 0.2 mil.
The fibers have an extraordinary current carrying capability in the region of ten microseconds to one millisecond because of the excellent coupling, i.e. intimate bonding, which takes place between the aluminum and glass. Consequently, the glass can serve as a heat sink. For example a 0.7 mil glass fiber with a 0.1 mil aluminum coating exhibits a heat capacity of twice that of the aluminum up to the melting point of the aluminum. Thus, for short time periods metal coated fibers are more efficient as a current carrier than 200 mesh aluminum screen with about the same aluminum content.
The particular fabric construction, i.e., the weave, is not critical. Virtually any fabric construction typical of prepregs can be utilized. Initially, a bundle 5 of aluminum coated glass fibers 20, 21 is twisted into a fiber yarn of essentially unidirectional fibers or two or more bundles are twisted about themselves into a yarn. Uncoated fibers may be made of the above mentioned E glass or of other materials such as a high temperature aramide available from I. E. duPont, under its trademark Kevlar.
Next, the yarns are woven into a fabric 4 by employing any desired combination of coated and/or uncoated fiber yarn. For example, hybrid yarns, i.e. aluminized and non-aluminized yarns twisted about themselves can be used in one direction, e.g. as the fill, of the weave while non-aluminized twisted glass yarns are utilized in the transverse direction, e.g. as the warp. Depending on the yarn material and the intended use, the fabric may be a mat or web of relatively open weave having relatively large interstices 12 between the yarns, or it may be a close weave fabric with relatively small or essentially no interstices.
The fabric is then impregnated with resin to form a prepreg fabric material, the resin being deposited onto the fabric from a solution in a conventional manner. Resins adapted for use with the present invention are uncured or partially cured resins, i.e. thermosetting resins which are not at all or only partially polymerized and high temperature thermoplastic resins such as polysulfones which, at the encountered temperatures act like thermosetting resins i.e. are moldable at elevated temperatures but hard at temperatures of use. For purposes of this disclosure and the claims the terms "cured resin" and "uncured resin" therefore also include thermosetting resins as well as thermoplastic resins which act in the above manner. The proportion of resin generally depends on the materials involved and the desired end use.
The proportion of resin to fiber is dictated by the strength-to-weight requirements of the fabricated parts. In particular, since the tensile strength comes from the fiber rather than the resin, a low resin content is desirable. While the proportions will vary according to the materials and the application, a cured prepreg sheet comprising a woven fabric (made of partially aluminum coated glass fibers) impregnated with a 250° F. curing epoxy resin should contain approximately 30-50% resin by weight. The prepreg layer may be rolled and/or laminated with other such layers depending on the characteristics of the prepreg desired.
Now referring to the FIG. 1 of the drawings, the overall process for making a finished, thermally and electrically conductive article from resin impregnated material (prepreg) is described. Initially, aluminum coated glass fibers (see FIGS. 2A and 2B) are formed into a yarn or bundle of, generally at least 45 and no more than 540, preferably 45 to 180, essentially unidirectional fibers. The yarn can, additionally contain fibers of other materials such as uncoated glass fibers. The bundle of fibers is then twisted to enhance its weavability. Since the present invention is particularly well adapted for use with partially aluminum coated glass filaments, the further description of the invention will be so directed. Next, the yarn of aluminum coated fibers is woven into a fabric as the yarn in one or both directions, i.e. as either or both the fill and the warp of the fabric.
Referring momentarily to FIG. 3. the fabric is a motor web defined by transverse, e.g. perpendicular yarns 5, a first series of which extends in a longitudinal direction and a second series of which extends in a transverse direction. The yarns define between each other generally square interstices.
Referring again to FIG. 1, the woven fabric is impregnated with resin to form a prepreg fabric material, the resin being deposited into the fabric from a solution. In a preferred embodiment of the invention, an aluminum coated glass fabric is impregnated with an amount of resin which generally represents approximately 35%-42% by weight of the prepreg material.
Thereafter, the prepreg material is laminated by placing at least two layers over each other in a mold or lay-up. Heat and pressure are applied to the prepreg to cure the resin and to thereby form the finished article. Depending on the particular characteristics desired in the prepreg laminate, some of the layers may comprise aluminum coated fibers according to the present invention, while other layers may comprise other prepreg materials. For example, in applications, such as those wherein a layer of conductive paint has heretofore been employed, i.e. where enhanced conductivity is desired on the surface, only the top prepreg layer or layers of the laminate may comprise conductive prepregs of the present invention.
It has been determined that two layers of prepreg material treated as above-described, each material layer having a thickness of no less than about 4 mils and no more than about 30 mils and a resin content or no more than about 50% by weight of the prepreg material, can be molded into a thin-walled (e.g. approximately 14 mils thick) finished article which has electric as well as thermal conductivity.
The following examples are provided by way of illustration and not by way of limitation.
EXAMPLE 1
Conductive fiber yarn comprising 22 aluminum coated glass fibers and 23 noncoated glass fibers (22/45) in which the glass fiber diameter was approximately 0.8 mils with the aluminum coated glass fibers having approximately 40% by weight aluminum coated around one-half the circumference of the fibers was twisted with 150 denier single (150 1/0) yarn. This was then used as the fill in weaving a cloth on the following construction:
Warp--two 150 denier glass yarns (150 1/2) (nonconductive)
Fill--150 1/0//22/45 (conductive)
Weave--8 harness satin
Weight--8.6 oz/yd 2
The fabric was then impregnated using conventional solution coating techniques with a 250 degrees F. curing epoxy resin to form a single ply conductive prepreg. The single ply conductive prepreg was then laminated and cured onto 4 plies of conventional epoxy/E-glass prepreg layers and tested for surface resistivity. The unit resistivity ranged from 0.006 to 0.02 ohm-cm.
EXAMPLE 2
Twelve piles of conductive prepreg constructed in accordance with Example 1 (with conductive yarn in fill direction) were laminated together and cured after which they exhibited the following mechanical properties.
______________________________________ Warp Fill (psi) (psi) Test Method______________________________________Tensile Strength 65,000 37,200 FTMS 1031Tensile Modulus 3.75 × 10.sup.6 3.35 × 10.sup.6Compressive Strength 68,200 61,500 ASTM D-695Compressive Modulus 3.8 × 10.sup.6 3.87 × 10.sup.6______________________________________
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A novel electrically and thermally conductive prepreg is provided comprising a resin impregnated fabric woven from a multiplicity of dielectric fibers at least some of which are metal-coated, e.g. aluminum-coated glass fibers. Articles made therefrom are useful for dissipation of static electricity, lightening strike protection, EMI shielding and antennae surfaces. Directional conductivity is achieved by orientation of the metal-coated fibers in the ply.
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INCORPORATION BY REFERENCE
U.S. Pat. Nos. 3,598,573; 3,876,421; 3,929,464; 3,998,625; 4,078,915; 4,137,072; 4,139,369; 4,194,902; 4,266,969; 4,315,773; 4,345,940; 4,395,282; 4,592,777; 4,705,561; 4,708,737; 4,764,211; 4,765,830; 4,832,739; 5,021,086; 6,352,570; and 6,372,014; and Luxemburg Patent No. 88,252 are incorporated herein by reference as examples of desulfurization agents that could incorporate the use of the reclaimed magnesium of the present invention.
The present invention relates to an apparatus and method of recovering magnesium, and more particularly to the recovery of magnesium from magnesium turnings and chips for use in a desulfurization agent that desulfurizes molten iron.
BACKGROUND OF THE INVENTION
The sulfur content in iron ores and other materials commonly used in pig-iron production, i.e. coal and coke, have increased the costs of steel making. As a result, it is becoming increasingly desirable to desulfurize the pig-iron before the iron enters the basic oxygen furnace and/or steel making furnace. In addition, specifications for the sulfur content of finished steel are decreasing to extremely low levels to make high strength low alloy steel, and steels resistant to hydrogen induced cracking, among other applications requiring low sulfur contents. In combination with the economic benefits of blast furnace operations producing molten pig-iron with decreased sulfur contents, the desulfurization of molten pig-iron external to the blast furnace before the molten pig-iron enters the steel making furnace has become a practical necessity.
Over the years, a wide variety of materials and mixtures have been used to desulfurize pig-iron. It has long been known that various calcium compounds are good desulfurization agents. It has also been known that magnesium, alone or in combination with various alkaline metal oxides, is also a good desulfurization agent. There have been several patents which disclose the use of calcium oxide and magnesium as the primary desulfurization agents. (See Skach 4,765,830; Skach 4,708,737; Green 4,705,561; Kandler 4,139,369; Kawakami 4,137,072; Koros 3,998,625.) Furthermore, desulfurization agents disclosing the use of calcium carbide as the primary desulfurization agent have also been known and well documented. (See Freissmuth 3,598,573; Todd U.S. Pat. No. 3,929,464; Braun U.S. Pat. No. 4,395,282.)
The use of a desulfurization agent that includes magnesium and iron carbide or high carbon ferromanganese is disclosed in Luxemburg Patent No. 88,252 dated Jan. 3, 1999 and invented by Axel Thomas. The desulfurization agent disclosed in Thomas '252 includes a majority of iron carbide or high carbon ferromanganese. The desulfurization agent also includes magnesium, and one or more additives to improve the formed slag.
The use of a calcium compound and/or magnesium, in combination with a gas-producing compound, has also been used to increase the amount of sulfur removal. It has been found that the gas-producing compound releases a gas upon contact with the molten pig-iron to create a turbulent environment within the molten pig-iron. The released gas primarily breaks down agglomerations of the desulfurization agent and disperses the desulfurization agent throughout the molten pig-iron. The gas-producing agent is typically a hydrocarbon, carbonate or alcohol which has a tendency to release various amounts of gas upon contact with the molten pig-iron. Use of these various gas-producing agents is well documented. (See Takmura U.S. Pat. No. 3,876,421; Meichsner U.S. Pat. No. 4,078,915; Gmohling U.S. Pat. No. 4,194,902; Koros U.S. Pat. No. 4,266,969; Freissmuth U.S. Pat. No. 4,315,773; Koros U.S. Pat. No. 4,345,940; Green U.S. Pat. No. 4,705,561; Rellermeyer U.S. Pat. No. 4,592,777; Meichsner U.S. Pat. No. 4,764,211; U.S. Pat. No. Meichsner 4,832,739; and Luyckx U.S. Pat. No. 5,021,086.)
The use of compounds to increase the desulfurization efficiencies of magnesium particles are disclosed in Bieniosek U.S. Pat. No. 6,352,570 and Bieniosek U.S. Pat. No. 6,372,014. High melting temperature particles are combined with and/or coated onto the magnesium particles to delay the melting of the magnesium particles.
Desulfurization agents can contain various slag-forming agents. The importance of the slagging agent generally has been passed over for more immediate concerns about the economics of using various ingredients of the desulfurization agent. The composition of the slag can be important to retain the removed sulfur within the slag and not allow the sulfur to re-enter the molten pig-iron. Various slagging agents have been used for various purposes. In U.S. Pat. No. 4,315,773 a desulfurization agent comprising calcium carbide, a gas-involving compound, and fluorspar is disclosed. Fluorspar is used to modify the properties of the slag to prevent carbon dust production from igniting during the desulfurization. In U.S. Pat. No. 5,021,086, fluorspars are used to modify the characteristics of the slag increasing the fluidity of the slag during the desulfurization process.
Many of the above described desulfurization agents remove the desired amount of sulfur and other impurities from molten iron. However, in an industry constantly driven by margins, there remains a need for a more cost effective desulfurization agent. The magnesium component of the desulfurization agent is typically the highest-cost component. Domestically, magnesium powder can cost up to $1.80/lb. Foreign sources of magnesium cost less, typically about $0.79/lb. As a result, there has been some interest in using magnesium scrap. Magnesium scrap is available from rejected and process scrap in the form of machined chips which are common in the automobile and electronics industry. Over the past several years, the amount of generated magnesium scrap has increased due to the increased use of magnesium. Magnesium metal is commonly machined using mineral oil and oil/water emulsions resulting in waste magnesium chips and turnings and cutting fluid. The cutting fluid can constitute up to 35-50 weight percent of the waste material. The magnesium/liquid mixture typically cannot be disposed of due to the reactivity of magnesium with water. The large volume of cutting fluid in the magnesium/liquid mixture increases the transportation costs of the mixture. Due to the transport costs and/or processing problems of the magnesium/liquid mixture, the mixture is commonly burned instead of being reclaimed.
Some progress has been made concerning the recovery of magnesium from a magnesium/liquid mixture. Several of these processes are disclosed in U.S. Pat. Nos. 2,299,043; 2,852,418; 3,656,735; 3,767,179; and 5,338,335. In these processes, the water and oil in the magnesium/liquid mixture is burnt off in a rotary kiln. The substantially oil free magnesium chips are then remelted and formed and/or extruded into a final product. Solvents may be used to separate a portion of the cutting fluid from the magnesium chips prior to drying the magnesium chips. Although these processes are successful in reclaiming magnesium, the energy costs associated with the heating of the magnesium/liquid mixture has not resulted in a cost effective process. In addition, combustion problems remain with the drying of the magnesium chips resulting in higher recovery costs. Furthermore, the oxidation of the magnesium during the drying process accounts for a significant loss of magnesium being reclaimed. Additional losses are encountered when using a solvent prior to drying.
Another process for reclaiming magnesium from a magnesium/liquid mixture is by pressing the mixture together to form a magnesium puck or briquette. This process can reduce the cutting fluid content of puck or briquette to about 7%. The squeezed out cutting fluid can be recycled and the transport costs of the magnesium in the form of a puck or briquette is significantly reduced. In addition, the puck or briquette can be more safely transported in such form. Although the compression process has several cost advantages, the cutting of fluid content of up to 7% poses problems for further processing of the compressed magnesium chips. Smelting of the magnesium pucks or briquettes is not feasible because of extreme flame and emissions generation. As a result, magnesium pucks or briquettes have not been accepted in the industry. In addition, the magnesium pucks or briquettes cannot be disposed of in land fills due to environmental and safety concerns.
In view of the present state of technology, there is a need for a lower cost and more effective process for recovering magnesium from magnesium scrap, which magnesium can be used in a wide variety of applications.
SUMMARY OF THE INVENTION
The present invention relates to an improved apparatus and method of recovering magnesium from magnesium scrap. The invention is particularly applicable to an apparatus and method of recovering magnesium from magnesium scrap for use in a desulfurization agent that desulfurizes molten iron and will be described with particular reference thereto; however, the invention has broader applications wherein the recovered magnesium can be extruded and/or remelted to form and/or be used in a variety of products that include magnesium metal (e.g., automotive parts, electronic components, etc.).
In accordance with the principal aspect of the present invention, the desulfurization agent for use in molten iron includes magnesium that has been at least partially reclaimed from magnesium scrap. In one embodiment of the present invention, a majority of the magnesium of the desulfurization agent is reclaimed from magnesium scrap. The magnesium scrap can be derived form a variety of sources. One common source is the automotive industry where many automotive components such as motors, gear boxes, steering wheels, etc. are made of or include magnesium; however, many other industries also generate magnesium scrap that can be used in the present invention (e.g., electronics industry, etc.). In addition, the magnesium scrap can come from post consumer scrap (PCS). It is estimated that over a million tons of magnesium scrap is generated by the automotive industry per year. Much of this magnesium scrap is mixed with oil and/or water. The oil and/or water functions as lubricant during the shaping and/or cutting of the magnesium during the formation of various components. Various prior art process have been developed to recycle magnesium scrap that includes oil. Several of these processes are disclosed in U.S. Pat. Nos. 2,299,043; 3,656,735; 3,767,179; and 5,338,335, which are incorporated herein by reference. In these processes, the water and oil in the magnesium/liquid mixture is thermally removed by burning off the oil and water in a heated rotary kiln. The substantially liquid free magnesium chips are then remelted and formed and/or extruded into a final product. Although these processes are successful in reclaiming magnesium which can be used in the present invention, the energy costs associated with the heating of the magnesium/liquid mixture remains a significant cost for the magnesium recovery. In addition, the heated magnesium frequently ignites resulting in down time and/or loss of magnesium product, and/or damage to the processing equipment. The heating and drying of the magnesium chips also results in significant amounts of oxidation of the magnesium, thereby resulting in loss of final magnesium product. The magnesium yields using standard drying techniques are typically no more than about 50%, and the analysis of the magnesium product includes typically no more than about 80-85% magnesium. The apparatus and method of the present invention utilizes a novel drying process for recovered magnesium which substantially eliminates oil and/or water that is combined with the magnesium chips. In accordance with one embodiment of the invention, a rotary tray dryer is used to at least partially dry the magnesium chips. The rotary tray dryer has been found to more efficiently dry the magnesium chips as compared with previously used rotary drum dryers or auger type dryers. The cost savings in using the rotary drum dryer for the magnesium chips results in an economically viable process for reclaiming magnesium from recycled magnesium. In one aspect of this embodiment, the rotary tray dryer is a continuous rotary tray dryer. In one non-limiting design, the continuous rotary tray dryer receives magnesium chips that include liquid such as, but not limited to, solvents, oil, water and the like. The magnesium chips are fed on a top tray of the rotary tray dryer, typically through an inclined chute. While the magnesium chips are on the trays, the trays are rotated and the magnesium chips arc exposed to a heated gas environment, which heated gas is used to at least partially remove the liquid from the magnesium chips. In another and/or alternative aspect of this embodiment, the rotary tray dryer includes a plurality of rotary trays. In one non-limiting design, the magnesium chips are transferred from tray to tray by passing the magnesium through chutes which extend between vertically adjacent trays. Upon rotation of the trays, wiper arms associated with each tray guide the magnesium chips over the laterally outer edges of the trays and into the upper ends of the chutes, while additional wiper arms and leveler arms associated with each tray distribute the magnesium chips transferred to the tray from the next highest tray evenly over the surface of the tray. One such rotary tray dryer that can be used is disclosed in U.S. Pat. Nos. 3,681,855; 3,728,797 and 3,777,409, which are incorporated herein by reference. In another and/or alternative non-limiting design, the rotary tray dryer is operated such that the magnesium chips are transferred between vertically adjacent trays at intervals of from about 1 minute to about one hour; however, other time intervals can be used. The total time the magnesium chips are resident in the rotary tray dryer is generally between about 2 minutes to four hours, and typically about 0.5-3 hours; however, other resident times can be used. In still another and/or alternative aspect of this embodiment, the rotary tray dryer includes a sufficient number of trays to provide a residence time for the magnesium chips to be sufficiently dried. In one non-limiting design, the rotary tray dryer includes 1-10 trays, and typically about 2-5 trays; however, other tray numbers can be used. In yet another and/or alternative aspect of this embodiment, the temperature within the rotary tray dryer is maintained sufficiently high to dry the magnesium chips; however, is maintained at a sufficiently low level to reduce loss of magnesium (e.g., oxidation of the magnesium, etc.) and to prevent the magnesium from melting. The temperature is also selected so that special costly components need not be used which would unduly increase the costs of recovering the magnesium. In addition, the temperature is selected so as not be too high resulting in undue high energy costs to dry the magnesium chips. The typical liquid components mixed with the magnesium chips are water and cutting fluid. Water has a boiling point of about 212° F. (100° C.) and the cutting fluid has a boiling point typically ranging from about 100-250° F. (38-121° C.). In one non-limiting design, the average temperature in the rotary tray dryer is about 250-1150° F. (121-622° C.), typically about 250-1000° F. (121-538° C.), and more typically about 350-700° F. (176-372° C.); however, other temperatures can be used. In still yet another and/or alternative aspect of this embodiment, the rotary tray dryer is heated by a heater such as, but not limited to, an electric heater, a gas burning heater, a oil burning heater, heating coils, and/or the like. In a further aspect of this embodiment, the rotary tray dryer can be operated under subatmospheric, atmospheric or superatmospheric pressure. In one non-limiting design, the rotary tray dryer is operated at atmospheric or sightly above atmospheric pressure. In still a further and/or alternative aspect of this embodiment, the rotary tray dryer reduces the liquid content of the magnesium chips to less than about 5 weight percent, and typically less than about 3 weight percent, and more typically less than about 2 weight percent, and even more typically less than about 1 weight percent. In still a further and/or alternative aspect of this embodiment, the rotary tray dryer reduces the liquid content of the magnesium chips by at least about 50%, typically at least about 75%, more typically at least about 85%, and still more typically at least about 90%.
In another and/or alternative aspect of the present invention, the internal atmosphere of the rotary tray dryer is maintained so as to limit or prevent combustion of the magnesium and/or other components in the rotary tray dryer. The common reactions that can take place which cause a fire or explosion in the rotary tray dryer include:
H 2 O+Mg→MgO+H 2 1.
Mg+O 2 →2MgO 2.
In addition to these two reactions, the hydrocarbons in the rotary tray dryer can combust in the proper atmosphere. When combustion of the magnesium occurs, magnesium recovery is reduced as indicated by the two above reactions. Once a fire has started, the magnesium is lost due to vaporization, melting, oxidation and/or the like. In addition, the rotary tray dryer may have to be stopped to terminate the fire, thereby reducing the amount of magnesium recovered over a period of time, and increasing the costs of magnesium recovery. The combustion in the rotary tray dryer may also result in damage to the rotary tray dryer resulting in significant down times and significant repair costs. When combustion of the oil, solvents and/or other hydrocarbons occurs, magnesium recovery is reduced and the magnesium recovery costs are increased for similar reasons. In one embodiment, the amount of oxygen in the rotary tray dryer is controlled during the drying process to limit or prevent combustion of the materials from occurring in the rotary tray dryer. The limiting of the oxygen content also reduces the amount of oxidation of the magnesium, thereby increasing magnesium recovery efficiencies. The oxygen content in the rotary tray dryer can be controlled in a number of ways such as, but not limited to, continuous oxygen removal and/or purging, insertion of non-oxygen gasses into the rotary tray dryer, and/or the like. In one aspect of this embodiment, the oxygen level in the rotary tray dryer is maintained at less than about 5 volume percent, typically up to about 4 volume percent, more typically up to about 3 volume percent, still more typically up to about 2.44 volume percent, still even more typically up to about 2 volume percent, yet still even more typically about 0-1.8 volume percent, still yet even more typically about 0.7-1.5 volume percent. In another and/or alternative embodiment of the invention, the amount of hydrogen and/or hydrocarbons in the rotary tray dryer is controlled during the drying process to limit or prevent combustion of the materials from occurring in the rotary tray dryer. Hydrogen gas is produced from the hydrocarbons that are vaporized during the drying of the magnesium. The hydrogen and/or hydrocarbon content in the rotary tray dryer can be controlled in a number of ways such as, but not limited to, continuous hydrogen and/or hydrocarbon removal and/or purging, insertion of non-hydrogen and/or hydrocarbon containing gasses into the rotary tray dryer, and/or the like. In one aspect of this embodiment, the hydrogen level in the rotary tray dryer is maintained at less than about 2.5 volume percent, typically up to about 1.5 volume percent, more typically up to about 1 volume percent, still more typically about 0-0.99 volume percent, still even more typically about 0-0.9 volume percent. In still another and/or alternative embodiment of the invention, the oxygen, hydrogen and/or hydrocarbon content within the rotary tray dryer is at least partially controlled by the introduction of an inert gas into the rotary tray dryer. The inert gas is typically selected so as not to 1) be flammable, 2) substantially react with magnesium, 3) form noxious compounds in the rotary tray dryer, 4) form a sediment in the rotary tray dryer and/or on the magnesium, 5) be toxic, 6) be environmentally unfriendly, and/or 7) damage the components of the rotary tray dryer. The inert gas should also be selected so as to not add significant cost to the drying of the magnesium. In one aspect of this embodiment, the inert gas includes one or more noble gases. In one non-limiting arrangement, a majority of the inert gas is one or more noble gases. In another and/or alternative arrangement, the inert gas is principally a single noble gas. In still another and/or alternative arrangement, the inert gas is at least 90 volume percent argon.
In still another and/or alternative aspect of the present invention, excess fluid is removed from the magnesium chips prior to drying the magnesium chips. The liquid content of the magnesium chips will vary from source to source. The liquid content can be as high as about 50 weight percent or more, and is typically about 25-48 weight percent liquid. The removal of some of this liquid by non-drying techniques can reduce the drying time and energy costs associated with the high liquid content mixture. In one embodiment, the magnesium chips and liquid are transported to screens which allow some of the liquid to flow through the screens to be separated from the magnesium chips. The magnesium chips and liquid can be transported to the screens by a number of different techniques such as, but not limited to, pumps, augers, conveyors, and/or the like. In another and/or alternative aspect of this embodiment, the screen size is selected to substantially prevent the magnesium chips from passing through the screens. Typically, the mesh size of the screen is about 50-400 U.S. standard mesh, more typically about 100-400 U.S. standard mesh, even more typically about 120-325 U.S. standard mesh, still even more typically about 140-325 U.S. standard mesh, and yet even more typically about 200-325 U.S. standard mesh. In another and/or alternative embodiment, the magnesium chips and liquid are transported to a chip-wringer or cyclonic separator to separate the excess liquid from the magnesium chips. In still another and/or alternative aspect of the present invention, at least about 1 weight percent of the excess liquid is separated from the magnesium chips. In one aspect of this embodiment, at least about 2 weight percent of the excess liquid is separated from the magnesium chips. In another and/or alternative aspect of this embodiment, at least about 3 weight percent of the excess liquid is separated from the magnesium chips. In still another and/or alternative aspect of this embodiment, at least about 4 weight percent of the excess liquid is separated from the magnesium chips. In yet another and/or alternative aspect of this embodiment, at least about 5-20 weight percent of the excess liquid is separated from the magnesium chips.
In yet another and/or alternative aspect of the present invention, the recovered magnesium is included in a desulfurization agent to remove sulfur from molten ferrous materials such as, but not limited to, molten pig-iron, ferro-silicon alloy, etc. Typically, the desulfurization agent is a solid material at least at ambient temperature (i.e. 70° F.). The solid desulfurization agent is formulated to maintain its solid form until at least just prior to being combined with the molten ferrous materials. The desulfurization agent is formulated to minimize the introduction of undesired materials, such as sulfur, into the molten iron during the desulfurization process. The desulfurization agent includes magnesium, and optionally one or more other agents that can facilitate in the removal of sulfur from the molten ferrous material. Such one or more agents include, but are not limited to a calcium compound, and/or a gas-producing compound. In one embodiment of the present invention, the calcium compound is selected to readily react with sulfur in the molten iron. The calcium compound can be a single calcium compound or a combination of two or more calcium compounds. In one aspect of this embodiment, various calcium compounds can be used such as, but not limited to, calcium carbide, calcium carbonate, calcium chloride, calcium cyanamide, calcium iodide, calcium nitrate and/or calcium nitrite. In one non-limiting formulation, the calcium compound primarily includes calcium oxide, calcium carbonate, and/or calcium carbide. In one aspect of this embodiment, the calcium compound constitutes at least about 1 weight percent of the desulfurization agent. In another and/or alternative embodiment of the present invention, the magnesium, other than the reclaimed magnesium, is included in the desulfurization agent. Such magnesium includes powdered ore magnesium, magnesium alloy and/or a magnesium compound. In one aspect of this embodiment, the total magnesium content constitutes at least about 5 weight percent of the desulfurization agent. In still another and/or alternative embodiment of the present invention, the gas-producing compound is selected to enhance the desulfurization efficiencies of the desulfurization agent. The gas-producing compound forms a gas upon contact with molten iron. The produced gas at least partially mixes the various components of the desulfurization agent throughout the iron to facilitate in enhancing the reaction between the various desulfurization agents and the sulfur in the molten iron. The produced gas can also facilitate in the breakup, mixing, and dispersement of the desulfurization agent in the molten iron so as to facilitate in increasing the active sites available for reaction with the sulfur, thereby further increasing the efficiency of sulfur removal from the molten iron. In one aspect of this embodiment, the gas-producing compound includes, water, hydrocarbons, alcohols, and/or carbonates. In another and/or alternative aspect of this embodiment, the gas-producing compound can be a liquid and/or a solid material. In one non-limiting formulation, the gas-producing material includes a solid compound such as, but not limited to, coal, plastic, rubber, solid hydrocarbons, solid alcohols, solid nitrogen containing compounds, solid esters and/or solid ethers. In another and/or alternative non-limiting formulation, the gas-producing material includes a liquid compound such as, but not limited to, liquid hydrocarbons. The liquid hydrocarbon can be saturated or unsaturated, halogenated or unhalogenated. In still another and/or alternative aspect of this embodiment, the gas-producing compound constitutes at least about 0.1 weight percent of the desulfurization agent. In one non-limiting formulation, the gas-producing compound constitutes at least about 1 weight percent of the desulfurization agent.
In yet another and/or alternative aspect of the present invention, the desulfurization agent is at least partially coated with a heat absorbing compound. The heat absorbing compound is formulated to absorb heat around the desulfurization agent. In one embodiment of the present invention, the heat absorbing compound is formulated to absorb heat about and/or closely adjacent to the desulfurization agent to increase the time the desulfurization agent remains in the molten iron for reaction with sulfur and/or to increase the reaction rate of the desulfurization agent. In another and/or alternative embodiment of the present invention, the desulfurization agent is pre-coated with the heat absorbing compound or coated with the heat absorbing compound just prior to being added to the molten iron. In still another and/or alternative embodiment, the particle size of the desulfurization agent is larger than the average particle size of the heat absorbing compound. In one non-limiting design, the heat absorbing compound constitutes at least about 1 weight percent of the coated desulfurization particle, typically at least about 2 weight percent, and more typically about 2-30 weight percent. In still another and/or alternative embodiment of the present invention, the particles of heat absorbing compound can form a blend and/or conglomeration with a single or a plurality of particles of desulfurization agent. In yet another and/or alternative embodiment of the present invention, the heat absorbing compound includes solid carbide compounds and/or ferroalloys. In one aspect of this embodiment, the carbide compound and/or ferroalloy has a higher melting point than the desulfurization agent. In still another and/or alternative aspect of this embodiment, the carbide compound and/or ferroalloy endothermically reacts and/or disassociates in the molten iron thereby absorbing heat. In still yet another and/or alternative embodiment of the present invention, at least a portion of the particles of heat absorbing compound are at least partially bonded to the particle surface of the desulfurization agent by a bonding agent.
In accordance with still yet another and/or alternative aspect of the present invention, the desulfurization agent is injected into molten iron by a lance. The melting of the components of the desulfurization agent in the transport pipe of the lance can be at least inhibited or overcome by mixing the desulfurization agent with and/or including in the desulfurization agent high melting temperature particles. The high melting temperature particles are designed to absorb heat as the high melting temperature particles and the magnesium particles are transported through the lance and into the molten iron. The absorption of heat by the high melting temperature particles inhibits or prevents the components of the desulfurization agent from melting or completely melting prior to being injected into the molten iron. By inhibiting the melting of the components of the desulfurization agent in the lance, the problems associated with plugging of the lance are reduced or overcome. In one embodiment of the present invention, the high melting temperature alloy particles are made up of two or more of the following metals namely, aluminum, antimony, beryllium, boron, calcium, chromium, copper, iron, magnesium, manganese, nickel, rare earth metals, silicon, silver, sodium, strontium, tin, titanium, vanadium, zinc, zirconium, and mixtures thereof. The specific composition of the high melting temperature particles is selected to obtain the desired heat absorbing characteristics of the particles when used in combination with the magnesium particles. The specific composition of the high melting temperature particles is also typically selected to minimize contamination of the molten iron. In another and/or alternative embodiment, the average melting temperature of the high melting temperature particles is about 2200° F.
In accordance with a further and/or alternative aspect of the present invention, the molten iron is shielded from the atmosphere during the desulfurization process. In one embodiment of the present invention, the shielding takes the form of creating an inert and/or non-oxidizing environment about the molten iron. The inert and/or non-oxidizing environment can be formed by placing the molten iron in a chamber filled with inert and/or non-oxidizing gas and/or by flowing an inert and/or non-oxidizing gas over the top of the molten iron during desulfurization. The inert and/or non-oxidizing environment inhibits or prevents oxygen from contacting the molten iron and oxidizing various components of the desulfurization agent and/or from reacting with the molten iron during desulfurization. Inert and/or non-oxidizing gases, which can be used to form the inert and/or non-oxidizing environment include, but are not limited to, helium, nitrogen, argon, and natural gas.
In accordance with still a further and/or alternative aspect of the present invention, a secondary calcium compound is co-injected with the desulfurization agent to assist in the removal of sulfur from the molten iron. The secondary calcium compound is selected to react with sulfur in the molten iron. Various calcium compounds can be used such as, but not limited to, calcium oxide, calcium carbide, calcium carbonate, calcium chloride, calcium cyanamide, calcium iodide, calcium nitrate, diamide lime, and calcium nitrite. In one embodiment of the present invention, the secondary calcium compound disassociates and the calcium ion forms in the molten iron so as to be available to react with the sulfur. The secondary calcium compound may or may not have a melting point which is less than the temperature of the molten iron. In another and/or alternative embodiment of the present invention, the secondary calcium compound is selected such that the ions previously associated with the calcium ion do not adversely affect the desulfurization process. In one aspect of this embodiment, the secondary calcium compound includes calcium oxide, calcium carbonate, and/or calcium carbide. In still another and/or alternative embodiment of the present invention, the particle size of secondary calcium compound is selected to provide the necessary reactivity or activity of the secondary calcium compound with the sulfur in the molten iron. When the particle size is too large, fewer calcium ions will be produced, resulting in poorer desulfurization efficiencies. In one aspect of this embodiment, the particle size of the secondary calcium compound is an average particle size of about 14 to about 500 U.S. Standard Mesh, typically about 14 to about 325 U.S. Standard Mesh, more typically about 16 to about 200 U.S. Standard Mesh, even more typically about 16 to about 100 U.S. Standard Mesh, still even more typically about 18 to about 100 U.S. Standard Mesh, and yet even more typically about 18 to about 50 U.S. Standard Mesh.
In accordance with yet a further and/or alternative aspect of the present invention, a slag-improvement agent is added to and/or co-injected with the desulfurization agent to generate a more fluid slag and/or to reduce the amount of liquid iron entrapped within the slag. Various slag-improvement agents can be used such as, but not limited to, metallurgical and/or acid grade fluorspar, dolomitic lime, silica, sodium carbonate, sodium chloride, potassium chloride, potash, cryolite, potassium cryolite, colemanite, calcium chloride, calcium aluminate, sodium fluoride, anhydrous borax, nepheline syenite, and/or soda ash. In one embodiment, a metallurgical and/or acid grade fluorspar is used such as, but not limited to, calcium fluoride. Metallurgical and/or acid grade fluorspar causes desired modifications to the physical properties of the slag. The amount of slag-improvement agent is selected to improve the slag characteristics without unduly reducing the viscosity of the slag, whereby the sulfur can easily transfer back into the molten iron.
In accordance with still yet a further and/or alternative aspect of the present invention, the desulfurization agent is injected beneath the surface of the molten iron, such as molten pig-iron. The desulfurization agent can be injected such that the coated desulfurization agent is injected by itself into the molten iron, injected with other components of the desulfurization agent, or co-injected with other components of the desulfurization agent. In one embodiment of the present invention, the components of the desulfurization agent are fluidized prior to being injected into the molten iron. In one aspect of this embodiment, the desulfurization agent is fluidized in a semi-dense state before being injected into the molten iron. The fluidized desulfurization agent is carried into the molten iron by a carrier gas. In another and/or alternative aspect of this embodiment, the carrier gas is inert and/or non-oxidizing to the components of the desulfurization agent. Carrier gases that can be used are, but not limited to, argon, nitrogen, helium, natural gas or various other inert and/or non-oxidizing gases.
The primary object of the present invention is the provision of an apparatus and method of reclaiming magnesium scrap and to reuse the reclaimed magnesium.
Another object of the present invention is the provision of an apparatus and method of reclaiming magnesium scrap that is economical and feasible.
Still another and/or alternative object of the present invention is the provision of an apparatus and method of reclaiming magnesium scrap that incorporates the use of a novel drying system.
Yet another and/or alternative object of the present invention is the provision of an apparatus and method of reclaiming magnesium scrap that reduces the incidents of combustion during the reclamation process.
Still yet another and/or alternative object of the present invention is the provision of an apparatus and method of reclaiming magnesium scrap which scrap can be reformed and/or remelted to be formed into a magnesium containing component for various types of industries (e.g., automotive, electronic, etc.).
A further and/or alternative object of the present invention is the provision of an apparatus and method of reclaiming magnesium scrap which scrap can be use as the sole component or one of the components of a desulfurization agent.
Still a further and/or alternative object of the present invention is the provision of a desulfurization agent that increases the efficiency of desulfurization of iron.
These and other objects of the invention will become apparent to those skilled in the art upon reading and understanding the following detailed description of preferred embodiments taken together with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention may take physical form in certain parts and arrangement of parts preferred embodiments of which will be described in detail and illustrated in the accompanying drawings which form a part hereof and wherein:
FIG. 1 is a flow chart illustrating the process steps for recovering magnesium from magnesium scrap;
FIG. 2 is a simplified diagram of the process steps for recovering magnesium from magnesium scrap as illustrated in FIG. 1; and,
FIG. 3 is a diagram illustrating the basic operation of a rotary tray dryer.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings, wherein the showings are for the purpose of illustrating the preferred embodiments of the invention only and not for the purpose of limiting same, FIG. 1 illustrates the improved process for recovering magnesium from magnesium scrap in accordance with the present invention. The demand for magnesium continues to grow in popularity as a substitute for steel and aluminum products. As more products are produced with magnesium, the amount of magnesium scrap has correspondently increased. Magnesium metal is commonly machined with the use of cutting fluids. The cutting fluids are typically used to increase the life of the cutting tools. As a result, the magnesium scrap from such processes constitutes a mixture of magnesium turnings or chips and cutting fluid. The cutting fluid commonly includes mineral oil, water and other lubricants. The mixture of magnesium and cutting fluid has posed significant handling and recycling problems due to the volume and weight of the mixture, and the instability of the mixture. Indeed, the mixture can contain up to 50 weight percent or more liquid. The present invention is an improved process for recovering magnesium from this magnesium scrap. The reclaimed magnesium has a very low liquid content and high magnesium content, thus the reclaimed magnesium can be extruded into magnesium containing components and/or remelted to be formed into magnesium containing components. The reclamation process of the present invention is more efficient, more effective, and less costly as compared with present reclamation processes.
Referring now to FIG. 1, post consumer scrap (PCS) and/or secondary metal turnings (SMT) 10 that include magnesium are collected from various manufacturers and/or other facilities. A few sources of PCS include electronic equipment, appliances, used automotive parts and the like. The PCS typically does not include a high liquid content (e.g. less than about 15 weight percent); however, the magnesium in the PSC is commonly mixed with other metals. One primary source of SMT is from the manufacture of automotive parts. The SMT typically includes a high liquid content (up to 50 or more weight percent) due to the use of cutting fluid during the manufacture of the automotive parts. FIG. 1 illustrates that the PCS and SMT to be processed includes about 17-48 weight percent liquid; however, the liquid content can be more or less. The collected PCS and/or SMT typically are sorted prior to being wet milled 12 : however this is not required. The sorting process is used to remove undesired materials from the PCS and/or SMT (e.g., ferrous materials, plastic, glass, etc.). A magnet can be used to facilitate in the removal of ferrous material from the PCS and/or SMT. Glass, plastic and/or other undesired materials can be removed by visual inspection. The PCS and/or SMT can also be pre-sorted by size prior to the wet mill process; however, this is also not required. Very large pieces and/or smaller pieces of PCS and/or SMT can be removed prior to the wet mill process.
After the PCS and/or SMT has been dumped into a hopper 14 and/or other holding container, the PCS and/or SMT is fed to the wet milling process as illustrated in FIGS. 1 and 2, typically by a feed belt 16 ; however, other feeders can be used (e.g. auger, pump, etc.). The wet milling process is designed to reduce the size of the PCS and/or SMT for further processing. The wet milling process typically includes a hammer mill that drives the PCS and/or SMT through a ¼ screen and into a mixing tank. As can be appreciated, the size of the screen can be larger or smaller. Typically, the magnesium contained in the PCS and/or SMT is less than about 3″ due to prior processing; however, this is net required. Water is typically added from a water reservoir 18 during the grinding process to facilitate in the sizing of the PCS and/or SMT. A hammer mill is typically used to reduce the incidence of combustion of the magnesium during the milling process; however, other grinding processes can be used. As can be appreciated, if the magnesium in the PCS and/or SMT is smaller than the screen size being used in the wet mill, the PCS and/or SMT can be directly fed into the mixing tank 20 without being subjected to the wet mill.
The PCS and/or SMT in the mixing tank is then transferred to a chip wringer 22 or continuous centrifuge to remove excess liquid from the magnesium. Typically the PCS and/or SMT are pumped from the mixing tank and into liquid separating screens and then into a cyclonic separator. The liquid separating screens initially remove the excess liquid from the magnesium and additional excess liquid is removed from the magnesium in the chip wringer or centrifuge. The amount of liquid typically removed from the PCS and/or SMT is at least about 5 weight percent. Typically, the liquid content of the PCS and/or SMT prior to entering the rotary tray dryer 24 is less than about 40 weight percent, typically less than about 35 weight percent, more typically less than about 30, even more typically less than about 25 weight percent, and still even more typically less than about 15 weight percent. The composition of the liquid that is associated with the PCS and/or SMT is generally about 1-20 weight percent water and about 80-99 weight percent oil and/or solvent; however, other liquid compositions may exist. As can be appreciated, the liquid separating screens can be the sole process used to separate the excess liquid from the magnesium prior to drying the magnesium. Alternatively, the chip wringer or centrifuge can be the sole process to separate the excess liquid from the magnesium prior to drying the magnesium. The collected excess liquid is transported to a filtering system 26 by a pump 28 and/or other device. The filter system is used to at least partially separate the water from other liquid components (e.g., oil, solvents, etc.) The filtered water can then be transported to the water reservoir that is used to supply water to the wet milling process and/or disposed of. The oil 30 , solvent, etc. that is filtered from the water in the filter system is transported to an oil recovery facility wherein the oil, solvent, etc. is recycled and/or disposed of.
Referring now to FIGS. 1 and 3, the PCS and/or SMT is transported to the rotary tray dryer from the chip wringer by a conveyor, auger, or the like 32 . A variable speed auger feeder is typically used to maintain a constant feed rate to the rotating drying tray. Each tray of the rotary tray dryer typically has at least one stationary bed leveler and a tray wiper. Each bed leveler is designed to spread the pile of PCS and/or SMT evenly on its respective tray so that it may be uniformly dried. Each tray rotates at a predetermined speed. Typically the trays rotate at the same speed; however, this is not required. After each tray rotates a predetermined distance, each respective tray wiper transfers the PCS and/or SMT through a respective opening to the next lower tray. After the drying is completed on the last tray, the PCS and/or SMT is transferred through an opening and transported to the next processing step. The rotary tray dryer provides continuous, automatic operation, thus requires little maintenance. The rotary tray dryer also provides relatively precise control of the drying temperature and the residence time of the PCS and/or SMT, as well as adjustable and automatically maintained drying. The specifications of the rotary tray dryer are selected based on the volume of PCS and/or SMT to be processed. The rotary tray dryer is typically a 2-10 rotary tray dryer wherein the trays are vertically spaced from one another. As can be appreciated, more trays can be used. The trays are typically designed to rotate about a central axis of the rotary tray dryer. A heated stream of gas 34 is introduced into the rotary tray dryer to heat the interior of the rotary tray dryer by convection. The interior temperature of the rotary tray dryer is maintained at about 300-800° F. (148-427° C.), and typically about 550-600° F. (287-316° C.). The resident time of the PCS and/or SMT in the rotary tray dryer is about 0.5-5 hours, and typically about 1-3 hours. The PCS and/or SMT is continuously fed onto the top tray of the rotary tray dryer and is thereafter distributed on the top tray at a generally uniform thickness of at least about 0.5 inch, and typically about 0.5-3 inches. The gas that is introduced into the rotary tray dryer is heated by an electric heater 36 ; however, other types of heaters can be used. The heated gas is used to heat the PCS and/or SMT in the rotary tray dryer, thereby vaporizing and removing the liquid on the PCS and/or SMT. The heated gas and the vaporized liquid are removed from the top 37 of the rotary tray dryer and transported into a condenser 38 . In the condenser, the gas and vaporized liquid are cooled and the vaporized liquid is removed from the gas. A solvent spray 40 (e.g., water) may be used to facilitate in the removal of the vaporized liquid from the gas. The condenser is cooled by cooling water 42 or some other cooling fluid. The condensed vapor is collected in the solvent receiver 44 at the base of the condenser. The collected liquid in the solvent condenser can be filtered and recycled and/or disposed of as illustrated in FIG. 1 . The gas from the condenser is passed through a demister 46 to further filter out any solvent, water, hydrocarbons and/or other liquids in the gas stream. A recycle fan 48 blows the gas from the demister through the electric heater and into the rotary tray dryer. A portion of the gas can be vented 50 out or additional gas can be added to the system as needed by use of the valves.
The type of gas that is inserted into the rotary tray dryer is selected to limit or prevent combustion of the magnesium and/or other components in the rotary tray dryer. Composition can occur from the reaction of the magnesium with water and/or oxygen, and/or combustion of the hydrocarbons in the rotary tray dryer. The gas is also selected to not adversely react with the compounds in the rotary tray dryer. An argon gas 52 is typically used to dry the PCS and/or SMT in the rotary tray dryer. Argon is an inert gas that does not react with any of the components in the rotary tray dryer. The flow rate of the argon through the rotary tray dryer is selected so as to control the amount of oxygen, hydrogen and/or hydrocarbon vapor or gas in the rotary tray dryer. Typically the flow rate of the argon into the rotary tray dryer is sufficient to limit the oxygen content in the rotary tray dryer to less than about 3 volume percent, and typically less than about 2.44 volume percent, and/or to limit the hydrogen and/or hydrocarbon content in the rotary tray dryer to less than about 1.5 volume percent, and typically less than about 1 volume percent. By controlling the oxygen and/or hydrogen content in the rotary tray dryer to these low limits, the incidence of combustion in the rotary tray dryer is significantly reduced. The rotary tray dryer can have a number of different configurations. One type of rotary tray dryer that can be used is disclosed in U.S. Pat. Nos. 3,681,855; 3,728,797 and 3,777,409, which are incorporated herein by reference, thus further details concerning the configuration and operation of the multi-tray dryer need not be further set forth.
The dried PCS and/or SMT has a liquid content of less than about 2 weight percent, typically less than about 1 weight percent, more typically less than about 0.5 weight percent, and even more typically less than about 0.1 weight percent. The dried PCS and/or SMT is substantially water-free. The dried PCS and/or SMT is then transported by conveyor, auger, etc. to a separator and/or grinder 54 . As the dried PCS and/or SMT is being transported from the rotary tray dryer, the dried PCS and/or SMT can be cooled by cooling screws or the like; however, such cooling is not required. The separator, if used, removes some of the remaining undesired material such as ferrous material. Such a separation can be done manually and/or by the use of a magnet. The dried PCS and/or SMT is typically screened 56 using a 16 U.S. stand mesh screen and subsequently ground so that a majority of the magnesium particles is about 30-80 U.S. standard mesh, and typically about 40-60 U.S. standard mesh. The magnesium percentage in the dried PCS and/or SMT is about 85.4-93%, and about 59-84% of the feed material was recovered as dried PCS and/or SMT. The same feed material using prior reclamation processes resulted in the magnesium percentage in the dried PCS and/or SMT of about 85%, and about 55% of the feed material was recovered as dried PCS and/or SMT. The reclamation process of the present invention results in a 4-29% increase in finished product recovery rate of magnesium as compared with prior processes. In addition, the percentage of magnesium in the finished product is about 0.4-7% greater than in prior processes. The increase in recovery rate and magnesium percentage is a significant improvement over prior reclamation processes. The ground magnesium can then be used as or a component of a desulfurization agent to remove sulfur from molten iron. Alternatively, the ground magnesium can be remelted or extruded to form magnesium containing components.
When the magnesium is to be used as a component of a desulfurization agent, the magnesium is commonly added to and/or co-injected with a calcium compound. The calcium compound is formulated to react with sulfur in the molten iron to form calcium sulfide in the slag layer. Typically, the desulfurization agent is added to pig-iron; however, the molten iron can be other types of iron. The particles of calcium compound which do not react with sulfur migrate into the slag layer. The magnesium vaporizes upon contact with the molten iron to form magnesium vapor bubbles. The vapor bubbles create turbulence in the molten iron as the vapor bubbles migrate up through the molten iron and through the slag layer. The turbulence caused by the vapor bubbles increases the sulfur removal efficiency by the desulfurization agent. A hydrocarbon containing compound can be added to the desulfurization agent to increase the turbulence during the desulfurization process.
The invention has been described with reference to the preferred embodiments. These and other modifications of the preferred embodiments as well as other embodiments of the invention will be obvious from the disclosure herein, whereby the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation. It is intended to include all such modifications and alterations in so far as they come within the scope of the appended claims.
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A method and apparatus of reclaiming magnesium from post consumer scrap and/or secondary magnesium turnings by feeding the post consumer scrap and/or secondary magnesium turnings into a rotary tray dryer and subjecting the post consumer scrap and/or secondary magnesium turnings to a controlled temperature and atmospheric environment to remove a substantial amount of liquid from the post consumer scrap and/or secondary magnesium turnings.
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This is a continuation of co-pending application Ser. No. 796,115, filed on Nov. 8, 1985, now abandoned.
FIELD OF THE INVENTION
The present invention relates to document handling and counting apparatus and more particularly to novel document handling and counting apparatus in which document sheets and bills of varying size may be handled without adjustment in the document handling apparatus.
BACKGROUND OF THE INVENTION
Apparatus presently exists for handling, counting and stacking sheets such as paper currency, checks, food stamps and the like. One apparatus which is highly advantageous for counting and stacking sheets is described in copending application Ser. No. 449,665 filed Dec. 14, 1982, now U.S. Pat. No. 4,615,518 issued Oct. 3, 1986 and assigned to the assignee of the present invention.
The above-mentioned copending application employs a technique for accurately controlling the feeding of sheets to the outfeed stacker, which technique is required in order to perform batching and/or counterfeit detection operations. The technique employed in the above-mentioned copending application utilizes electromagnetic brake and clutch mechanisms to perform the above-identified operations.
The apparatus of the above-mentioned copending application employs a feed roller and cooperating stripper shoes for feeding sheets one at a time through the sensing and counting devices. It has been found that the mechanism employed for feeding and stripping sheets has the disadvantages of causing damage to the edges of the sheets as well as causing streaking and/or scuffing of the sheets, and especially stiff new sheets such as new paper currency
BRIEF DESCRIPTION OF THE INVENTION
The present invention provides improved sheet handling and counting apparatus which is characterized by comprising means which is greatly simplified as compared with the apparatus of the above-mentioned copending application for handling and counting sheets and which, for example, totally eliminates the need for electromagnetic clutch and brake means while at the same time, being capable of performing all of the operations previously requiring such apparatus.
The sheet handling and counting apparatus of the present invention comprises a feed roller directly coupled to a drive motor. The drive coupled to the feed roller is also directly coupled to the picker roller utilized for advancing the bottom sheet from an input tray to the feed roller.
A pair of acceleration rollers are directly driven by the feed roller and cooperate with a pair of acceleration idlers for accelerating sheets fed into the nip between said acceleration rollers and idlers for delivering and rapidly urging the sheets toward an output stacker.
The output stacker includes stacker wheels coupled to the drive motor through a one-way clutch which enables freewheeling rotation of the stacker wheels even after the motor has been abruptly halted.
An idler roller cooperates with the feed roller for positively advancing sheets toward the acceleration nip.
The large diameter acceleration rollers and cooperating idler impart more positive acceleration drive to the sheets while at the same time operating at reduced angular velocity as compared with prior art techniques. The use of a dynamic braking technique provides feeding of only those sheets desired to be fed to output stacker, while eliminating the need for the electromagnetic clutch and brake required in prior art apparatus.
The orientation of the strippers relative to the feed roller and the path of incoming sheets is such as to substantially totally eliminate scuffing and damaging of the sheets being handled and counted.
The apparatus further employs a dancer roller assembly which cooperates with the feed roller to provide sufficient drive for advancing the last few sheets in a stack to the feed nip to assure positive feed to these sheets as well as facilitating the handling of light, fluffy sheets.
OBJECTS OF THE INVENTION AND BRIEF DESCRIPTION OF THE FIGURES
It is therefore one object of the present invention to provide a novel sheet handling and counting apparatus of simplified design which is capable of handling and counting sheets of various sizes without mechanical adjustment.
Still another object of the present invention is to provide novel apparatus for handling and counting sheets and which is capable of accurately controlling the feeding of sheets to the output stacker while eliminating the need for electromagnetic clutch and brake devices required in conventional apparatus.
Still another object of the present invention is to provide a novel feed and stripper arrangement which substantially eliminates the scuffing and wearing of sheets handled by the apparatus.
The above as well as other objects of the present invention will become apparent when reading the accompanying description and drawing in which:
FIG. 1 shows an elevational view of sheet handling and counting apparatus design in accordance with the principles of the present invention.
FIG. 2 shows an exploded view of the stripper shoes and feed, acceleration and pinch rolls employed in the arrangement of FIG. 1 in greater detail.
FIG. 3 is a simplified diagramatic view showing the drive train for the sheet handling and counting apparatus shown in FIG. 1.
FIG. 3a is a diagrammatic elevational view of the apparatus of FIG. 1 showing the drive train of the apparatus.
FIGS. 4a and 4b show perspective views of the enclosure portions making up the enclosure for the sheet handling and counting apparatus of FIG. 1.
FIGS. 5a-5f shows views of the assembly for mounting the stripper shoes and acceleration and feed pinch rollers shown in FIG. 1.
FIGS. 6a and 6b show side end views of the holding clip employed for holding the stripper shoes in the operative position.
FIGS. 7a and 7b show side end views of one stripper shoe.
FIG. 8a shows an elevational view comparing the conventional stripper and feed roller arrangement with the arrangement of the present invention.
FIG. 8b is an enlarged view of the stripper and feed roller arrangement of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows sheet handling and counting apparatus 10 embodying the principles of the present invention, the housing for said apparatus being comprised of housing portions 12, 14, 16 and 18 shown respectively in FIGS. 1, 4a and 4b. The sheet handling and counting apparatus 10 shown in FIG. 1 is arranged within the main housing portion or chassis 12 which is shown in FIG. 4a and comprises a base 12a, generally triangular-shaped side-walls 12b and 12c, rear wall 12d having a large opening 12e, top wall 12f and diagonally upwardly extending portions 12h and 12i on sidewalls 12b and 12c. Portions 12h and 12i have openings (to be more fully described) for securing elongated, substantially rectangular-shaped housing 14a (FIG. 4b) which contains the system electronics. The numbered openings in the sidewalls 12b, 12c represent the shafts supported by these openings. Opening 14b in front wall 14a of housing 14 exposes the control panel operating members (not shown for purposes of simplicity). A display panel (not shown) is positioned in opening 14d.
Side covers, not shown, are arranged to cover the mechanical mechanisms and other components projecting beyond and/or mounted along the outer surfaces of triangular-shaped side-walls 12b and 12c. A plate 17 is positioned across the forward open end of the chassis and has: a curved portion 17a which is aligned with the sheet accelerating assembly (to be described below) and is provided with slots 17b, 17c through which the stacker wheels extend. Ribs 17d guide sheets from the acceleration assembly towards the stacker wheels.
The rear opening 12e in housing portion 12 shown in FIG. 4a is covered with a releaseable cover member (not shown) to enable access to the rear of chassis 12.
An output tray 27 is joined to chassis 12 for receiving and stacking sheets delivered to the output tray.
The electronics and display enclosure 14 shown in FIG. 4b has a top surface 14f which serves as the floor 24 of input tray 22 (see also FIG. 1) for receiving a stack of sheets to be counted.
Movable sidewalls 23, 25 define the side supports for supporting a stack of sheets and move either in unison or individually either further apart or closer together to adjust the input tray side supports to accomodate a stack of sheets of any size within certain predetermined limits, as will be more fully described.
The upper portion of the apparatus 10 shown in FIG. 1 includes input tray 22 with floor 24 for receiving a stack of sheets to be counted. The sheets move through apparatus 10 and, after being handled and counted, are neatly stacked in output tray 27.
Input tray 24 is comprised of an inclined supporting surface 14f (see also FIG. 4b) which supports a stacks of sheets. Rear supporting surface 16a-1 (see FIG. 1) provided at the lower end of surface 16a, engages the leading edges of a group of sheets at the bottom of the stack of sheets and serves to "fan" the stack of sheets to facilitate the feeding operation. The leading edges of the bottom group of sheets within the stack move toward a nip N 1 , defined by feed roller 26 mounted upon shaft 26a. Shaft 26a is supported by openings 12b-1 and 12c-1 in chassis sidewalls 12b, 12c. The feed roller 26, which is shown in detail in FIG. 2, is formed of a suitable rubber or rubber-like material having a durometer of the order of 65 SHORE A. The feed roller 26 is provided with two rectangular-shaped annular grooves 26b, 26c which cooperate to form three (3) rectangular-shaped annular projecting portions 26d, 26e and 26f of increased diameter relative to annular recesses 26b and 26c.
Bearings 28b and 30b freewheelingly mount pulleys 28 and 30 upon shaft 26a. Pulley 28 is provided with an annular groove 28a of substantially semi-circular-shaped cross-section for receiving and supporting a resilient O-ring 29, entrained about groove 28a of pulley 28 and the groove 32a of an acceleration pulley 32 shown in FIGS. 1 and 3, for imparting drive to pulley 28 through pulley 32 and O-ring 29.
Pulley 30, positioned on the opposite side of feed roller 26, is provided with an annular groove 30a of substantially semi-circular cross-section. Pulley groove 30a receives a resilient O-ring 29' shown in FIG. 3 and which is similar to O-ring 29. O-ring 29' is received within a groove 34a in acceleration pulley 34 shown in FIG. 3 and which is substantially identical to acceleration pulley 32 shown in FIGS. 1 and 3.
An O-ring 35 (see FIG. 3) is arranged within annular groove 113a of pulley 113 and in an annular groove 37a of pulley 37 provided on shaft 39a. Picker roller 39 arranged on shaft 39a drives the bottom sheet of the stack from tray 24 into nip N 1 .
Swingable guide plate 31 (see FIGS. 1, 5a, 5c) has: a curved portion 31a, which curves about feed roller 26 as shown best in FIG. 1; a substantially straight upper portion 31b which extends towards straight portion 16a-1 and a straight lower portion 31c which extends towards output tray 27. The portion 17a of cover 17 (see FIGS. 3a and 4b) curves about the stacker wheels to guide sheets to the stacker wheels, as will be more fully described.
The curved guide plate 31 forms an integral part of a guide plate assembly 50 (see FIGS. 5a to 5g) and is provided with an opening 31a-1 (FIG. 5a) through which feed pinch wheel 40 extends. Pinch wheel 40 rollingly engages central portion 26e of feed wheel 26, as can be seen in FIG. 2, to form a nip N 2 . The pinch wheel shaft 40a extends through a pair of elongated, oval-shaped openings 41a, 41a in support plates 41, 41, which plates are integrally joined to guide plate 31 of swingably mounted guide plate assembly 50 to be more fully described. Spring means 42, 42 encircle pin 42a, have the ends of arms 42b, 42b secured to plates 41, 41 and have the opposite ends of arms 42b, 42b arranged to engage the shaft 40a to resiliently urge the feed pinch wheel 40 against feed wheel 26.
The stripper assembly 44 (FIGS. 1, 5d, 5e, 5f) is comprised of a pair of individual stripper members 44a, 44b, having a durometer of 80±5, Shore A, removably mounted upon a mounting member 53 forming part of swingably mounted guide plate assembly 50, which assembly 50 is pivoted about pivot pin 45a for swingably moving stripper assembly 44, feed pinch roller 40, and acceleration pinch rollers 46 and 48 into and out of their operative positions. A pin 44c extends through openings in stripper shoes 44a, 44b and opening 53a in mounting member 53 (FIG. 5d) to hold the stripper shoes on member 53. A stripper clip 60 (FIGS. 6a, 6b) snaps upon stripper shoes 44a, 44b (FIGS. 7a, 7b) so that arms 60a, 60b press stripper shoes 44a, 44b towards mounting member 53 and hold pin 44c in place. The indentation 60d in the top 60c of clip 60 enters the slots 44s, 44s in stripper shoes 44a, 44b to properly mount clip 60 relative to shoes 44a, 44b. The forward end 60e curves about the forward ends of stripper shoes 44a, 44b to protect the forward ends of the stripper shoes 44a, 44b and to reduce the sliding friction between the stripper shoes and the incoming sheets to facilitate feeding of sheets into the feed nip N 1 .
Acceleration pinch wheels 46 and 48, shown in FIGS. 1 and 2, are each mounted upon a common shaft 46a, which is arranged for slidable movement within an elongated oval-shaped pair of openings 49b, 49b provided in mounting brackets 49, 49 integrally joined to guide plate 31 of swingable guide plate assembly 50. Each of the acceleration pinch wheels 46 and 48 is urged against its associated acceleration wheel O-ring 33, 33, shown in FIGS. 1 and 3, by means of torsion springs 51 having one end portion 51a arranged around pin 45a and having the other end portion 51b arranged around shaft 46a.
By moving swingably mounted guide plate assembly 50 counterclockwise about pivot 45 (see arrow A), wheels 40, 46 and 48 are moved away from cooperating wheels 26, 32 and 34, respectively and the stripper assembly 44 is moved away from feed wheel 26 to facilitate inspection, maintenance and repair operations. The assembly 50 may be swung clockwise (arrow B) to return the last-mentioned components to the operative position.
The stripper members 44a, 44b each have a curved lower surface as shown in FIGS. 1 and 7a, the surface being comprised of a convex curved portion 44a-1 and a concave curved surface portion 44a-2 joining the convex curved surface portion 44a-1. The right-hand end of the convex curved surface 44a-1 forms a tapering entrance region or throat with the feed wheel 26. The width of each stripper 44a, 44b is less than the width of the associated groove 26b, 26c (FIG. 2) provided in feed roller 26, enabling the left-hand-most portion of the convex curved surface to preferably extend at least slightly into its associated recess 26b, 26c. The upstream end of the convex surface portion cooperates with the periphery of portions 26d, 26e and 26f of feed roller 26 to define a tapered throat for guiding the leading edge of a sheet into the feed nip N 1 , (see FIGS. 1 and 8b). The downstream end of each of the stripper shoes 44a, 44b extends at least partially into an associated one of the grooves 26b, 26c. At the point X 2 (FIG. 8b) where the rearward end of the convex surface portion intersects with the periphery of the feed roller 26, the surface is concave. The concave surface portion 44a-2 lies outside of the periphery of feed roller 26. The point X 3 represents the portion of the convex surface of the stripper shoes which makes the deepest penetration into the cooperating recess 26b, 26c of feed roller 26. The point X 3 of deepest penetration is oriented so that the line L 3 passing through the axis of rotation of feed roller 26 and the point X 3 (hereinafter referred to as the "pinch line") forms an angle of 15°±5° with imaginary vertical line L to yield the optimum desired results of feeding sheets one-at-a-time without damaging or scuffing the handled sheets.
The supporting surface 24 of the input tray is preferably inclined at an angle of 23°±5° to the imaginary horizontal line L 2 to optimize feeding of sheets from the input tray into feed nip N 1 . The relationship between the inclination of the input tray and the orientation of the stripper shoes is such that the angle therebetween is equal to 15°=(90°-23°)=15°+67°=82°± °, and is preferably 82°±8°.
Although the preferred stripping surface of the stripper shoe has a shape and contour, for example, as shown in FIG. 8a, the stripping surface may have a convex contour such as a round or circular shaped periphery. As another alternative, the convex stripping surface need not penetrate into a recess in the feed roller and need only be positioned in close proximity to the periphery of the feed roller. Regardless of the amount of penetration, it is nevertheless important that the pinch line L 3 forms an angle of 15°±5° with the imaginary vertical line and preferably that the pinch line form an angle of 82°±8° and most preferably an angle of 82°±5°.
In the absence of sheets, the stripper shoes 44a, 44b do not engage feed roller 26. In the presence of sheets, and due to the partial projection of each stripper shoe 44a, 44b into an associated recess 26b, 26c of feed roller 26, each sheet fed into nip N 1 is urged into an undulating configuration which stiffens the sheets and greatly facilitates feeding of the sheets.
Also, the diameter of the feed roller is preferably reduced of the order of 14 to 15 percent relative to feed rollers employed in conventional apparatus, providing a feed roller having an outer periphery with a radius of curvature smaller than that of conventional feed rollers. The diameter of feed roller 26 is preferably 1.5"±0.2". FIG. 8a shows the conventional arrangement and the arrangement of the present invention superimposed upon one another. Dotted roller 26 and dotted stripper shoes 44a represent the arrangement of the present invention. Roller R and stripper shoe S shown in solid-line fashion represent the conventional arrangement. Plates 24 and 31 respectively represent the floor of the input tray and the guide plate (see FIG. 1). This arrangement has the unique, remarkable and totally unexpected result of reducing damage to processed sheets of the order of 99% or greater and substantially eliminating the nicking or cutting of the leading edges of the handled sheets entering the nip N 1 . The new design also prevents mutilated sheets from being damaged and prevents sheets from developing rolled edges as a result of sheet handling by the apparatus. Streaks and scuffs normally found on sheets such as brand new paper currency are also totally eliminated by the design of the present invention. The conventional arrangement does not provide these unique results.
The feed wheel 26 is formed of a material having a greater coefficient of sliding friction than the stripper members 44. When a single sheet is fed into nip N 1 , the feed wheel 26 exerts a greater force upon the single sheet than the drag force imparted to the sheet by the stripper members 44a, 44b, causing the sheet to move in the forward feed direction. In the event that two or more sheets are fed into nip N 1 , the frictional force exerted upon the bottom sheet by feed roller 26 is greater than the force exerted upon the top of the bottom sheet by the upper sheet, causing the bottom sheet to be moved in the forward feed direction. Conversely, the force exerted by the stripper members 44a, 44b upon the top surface of the upper sheet is greater than the force exerted upon the bottom surface of the upper sheet by the lower sheet, preventing the upper sheet from moving in the forward feed direction and thereby feeding only single sheets through nip N 1 . Substantially the same operation occurs with multiple feed sheets greater than two in number.
Single fed sheets passing through nip N 1 are guided through a curved guide path formed by plate portion 31a and feed wheel 26. The leading edge of the sheet passing through nip N 1 approaches and enters nip N 2 formed between feed roller 26 and idler roller 40 to provide positive feeding of the sheet about the curved guide path.
The leading edge of the aforementioned sheet passes through nip N 2 and enters into a guide region defined by the straight portion 31c of plate 31 and the O-rings 29, 29' entrained about the pulleys 28, 30 mounted upon the same shaft 26a as feed roller 26 and the pulleys 32, 34. The O-rings 29, 29' form an acceleration nip N 3 with the acceleration pinch wheels 46, 48. When the leading edge of a sheet enters nip N 3 , the sheet is abruptly accelerated in the forward feed direction and moved along the lower end of guide plate 31c and a cooperating guide surface 58 (FIG. 1). The leading edge of a sheet eventually enters into a pocket 56a formed by a pair of adjacent flexible blades 56b, 56b' provided on the stacker wheels 56. The sheet is delivered to the base portion 27a of input tray 27 which strips the sheet from its pocket 56a and stacks the sheet in the output tray 27. Portions 27b, 27c of the input tray served to hold the stack of accumulating sheets in a generally upright position.
FIGS. 5a through 5f show the guide plate assembly 50 in greater detail as being comprised of guide plate 31 having opening 31a-1 through which the feed roller pinch wheel 40 extends and openings 31e, 31f through which the acceleration pinch wheels 46, 48 extend (FIG. 1). Arms 49, 49 are integrally joined to the rear of guide plate 31 and are each provided with opening 49a for receiving a pivot pin 45a for swingably mounting assembly 50 to the stacking apparatus frame. Elongated openings 49b each receive a common shaft 46a, which rotatably support the acceleration pinch wheels 46 and 48 a spacer 47 maintains the pinch rollers 46, 48 in a properly spaced apart arrangement to align rollers 46, 48 with the openings 31e, 31f in guide plate 31. Torsion spring 57 shown in FIG. 1 urges the shaft 46a of the acceleration pinch wheels 46, 48 toward the acceleration roller 32. The pinch wheels 46, 48 rollingly engage the O-rings 29, 31 (FIG. 3).
Arms 41, 41 integrally joined to the rear surface of guide plate 31 are each provided with an elongated opening 41a which receives the common shaft 40a of feed wheel pinch roller 40. The aforementioned torsion spring 42 urges shaft 40a and hence roller 40 towards feed roller 26. The pinch roller 40 engages the surface of the central projection 26e of feed wheel 26, providing positive driving of the sheet just as the sheet is ready to leave the influence of the feed wheel 26. In addition, the orientation of the pinch roller 40 relative to the feed wheel and the acceleration nip N 3 assures that the sheets are positively driven in the proper direction. Pinch roller 40 also cooperates with the feed roller to hold a sheet which is in nip N 2 when the apparatus is abruptly halted to prevent that sheet from reaching the acceleration nip N 3 .
Openings 31g, 31h in guide plate 31 are provided to permit the passage of light from light sources designated LED (see FIG. 1) mounted upon guide plate 58. Suitable openings are provided in guide plate 58 through which the feed roller 26, acceleration rollers 32, 33, and O-rings 29, 29' extend. Sensors 61 are mounted upon plate 31 and are aligned with openings 31g, 31h and function as count sensors to detect the passage of a gap between sheets for sheet counting purposes.
The O-rings 29, 29' prevent sheets moving between the second feed nip N 2 and the acceleration nip N 3 from moving away from the feed path and also aid in moving the sheet towards nip N 3 . A gap space is provided for the O-ring surfaces in the region of the feed nip N 1 to allow the leading edge of a light or curled sheet to engage the O-rings and thereby provide positive feed to incoming sheets, assisting the picker roller 39 in feeding sheets into the first feed nip N 1 . A dancer roller assembly 130 is comprised of an arm 131 swingably mounted to a shaft 132 extending through an opening 131a in arm 131 and openings 41c, 41c in arms 41, 41. A pair of rollers 133, 133 are freewheelingly mounted upon a shaft extending through an opening 131b in arm 131 (see FIG. 2). Rollers 133, 133 are each arranged to cooperate with feedwheel 26 and lightly engage the surfaces 26d, 26f of the feedwheel to assist in the feeding of light, fluffy sheets. Stiffer sheets simply move the dancer rollers away from the feedwheel 26. The dancer rollers also provide sufficient drive friction to assure feeding of the last few sheets in the input tray into the feed nip N 1 .
The swingable movement of guide plate assembly 50 provides ready access to the components mounted thereon as well as the components facing the guide plate 31, thus greatly facilitating inspection, maintenance and repair of the equipment. Shaft 71 (FIG. 1) cooperates with a spring 73 for releaseably securing assembly 50 in the operating position. The curved end 73a of spring 73 releaseably snaps onto post 71 (see FIGS. 1 and 3a). Threaded member 75 threadedly engages the tapped aperture 67a and bears against post 71 to easily and yet accurately adjust the location of the stripper shoes 44a, 44b relative to feed roller 26.
The apparatus 10 of FIG. 1 is capable of handling sheets of varying length measured in the feed direction without any adjustment whatsoever. The only adjustment provided is the sliding movement of the side-wall members 23, 25 (see FIG. 4b) provided for alignment of sheets of varying length measured in a direction perpendicular to the feed direction. Side-wall supports 23, 25 are movable either closer together or farther apart to facilitate the formation and maintaining of a neat, upright stack within the input tray preparatory to a sheet handling and counting operation.
The power train for the sheet handling apparatus of FIG. 1 is shown best in FIGS. 3 and 3a and includes motor M driving a pulley 77 having a pair of grooves 77a for receiving a pair of O-rings 79 which are entrained about grooves 77a in pulley 77 and grooves 83a in pulley 83 rovided on stationary shaft 81. The pulley 83 is freewheelingly mounted upon shaft 81. Integral therewith are pulleys 85 and 87. Pulleys 83, 85 and 87 rotate as an integral unit and are freewheelingly mounted upon shaft 81. O-ring 89 is entrained about the groove 87a in pulley 87 and the groove 91a in pulley 91 mounted upon shaft 93. A flywheel 95 is mounted upon shaft 93. One-way clutch assembly 96 (FIG. 3) is coupled between shaft 93 and pulley 91 to enable shaft 93 and flywheel 95 to continue rotation when motor M has been abruptly halted. The left-hand end of shaft 93, which is supported by bearings 97a, 97a mounted within housing 99, rollingly engages the rubber surface of roller 101 secured to the stacker wheel shaft 56c. Housing 99 further incorporates bearing 97b for mounting shaft 56c.
O-rings 103 are entrained about the grooves 85a in pulley 85 provided on stationary shaft 81 and bear against the grooves 105a in pulley 105 and are entrained about grooves 107a of pulley 107 mounted upon the feed assembly shaft 26a. Pulley 107 is secured to shaft 26a. Pulley 109 is integral with pulley 107 and is provided with grooves 109a receiving O-rings 112 which are entrained about grooves 109a and grooves 111a provided in pulley 111 mounted upon shaft 32b. Pulley 111 is secured to shaft 32b and rotates shaft 32b, as well as acceleration pulleys 32 and 34. The O-rings 29 and 29' entrained about grooves 32a and 34a of pulleys 32 and 34 and about grooves 28a and 30a in pulleys 28 and 30, rotate the pulleys 28 and 30, which are freewheelingly mounted upon feed shaft 26a, at an angular velocity which is significantly greater than the angular velocity of feed roller 26.
A pulley 113, integral with pulleys 107 and 109, is further provided on shaft 26a. O-ring 35 which is entrained about groove 113a of pulley 113 and groove 37a of pulley 37 mounted upon picker wheel shaft 39a, imparts rotation to picker wheel 39.
An encoder 115 is mounted upon shaft 32b and provides timing pulses for use by the electronic controls employed for operating the apparatus 10. The pulse rate of the pulses generated by encoder 115 is a function of the output speed of motor M. Thus, any changes in motor speed is directly indicated by encoder 115.
The operation of the apparatus is a follows:
Motor M is energized causing rotation of feed roller 26, acceleration pulleys 32 and 34, picker roller 39, acceleration idlers 28 and 30 and the stacker wheels 26. The tangential velocity of the acceleration pulleys 32 and 34 is significantly greater than the tangential velocity of the periphery of feed roller 26, causing the tangential velocity of the O-rings on the freewheeling pulleys 28 and 30 to be greater than the tangential velocity of feed roller 26. O-rings 29, 29' and dancer rollers 133, 133 aid in the feeding of the light, fluffy sheets into feed nip N 1 . Sheets are accelerated by nip N3, being positively fed thereto by nip N 2 . Accelerated sheets are fed to stacker wheels 56 and are ultimately stripped from the stacker wheel pockets 56a and collected in the output tray.
If, for any reason the motor M is halted the picker roller 39, acceleration pulleys 32 and 34, feed roller 26 and acceleration idlers 28 and 30 are abruptly halted. However, the one-way clutch assembly 97 disengages pulley 91 from shaft 93. The inertia of flywheel 95 causes the flywheel to continue rotating thereby rotating shaft 93 which rotates stacker shaft 56c and stacker wheels 56 through roller 101, thus assuring that sheets which have reached stacker wheels 56 are delivered to the output tray 27. When motor M is abruptly halted, any sheets between the nips N 1 , N 2 or N 3 are also abruptly halted, thus assuring an accurate count of sheets reaching the output tray 27.
A sheet entering acceleration nip N 3 is abruptly accelerated causing a wider gap between the trailing edge of the accelerated sheet and the leading edge of the next sheet being feed toward nip N 3 to facilitate counting, which is accomplished by the LED light sources and cooperating sensors 61.
The apparatus may also be provided with magnetic sensing means utilized to detect suspect counterfeit currency. The sensing apparatus is comprised of a pair of magnetic heads 117 and 119 shown in FIG. 2. The sensing heads 117, 119 are arranged within openings 31j and 31k in guide plate 31 shown in FIG. 5a. Openings 31m and 31n, also provided in guide plate 31 each receive a permanent magnet member, causing those portions of the currency being processed moving over the magnetic heads 117, 119 to pass through magnetic fields created by these magnetic heads, thereby exerting an influence upon ferromagnetic particles contained within the ink utilized to print the paper currency. These particles experience some magnetization and, when these magnetized particles move over the sensors 117, 119, the magnetic head sensors generate electrical signals, the presence of which indicate genuine currency and the absence of which indicate suspect counterfeit currency.
The sensitivity of the counterfeit detection apparatus is greatly enhanced by the provision of freewheeling rollers 123, 125 (see FIGS. 3 and 5a) which rollers are freewheelingly mounted upon acceleration shaft 32b to urge the bills toward the magnetic head sensors. The freewheeling rollers 123, 125, being free to rotate independently of shaft 32b, do not cause any wearing of the paper currency. The periphery of each roller is spaced from the associated magnetic head sensor to prevent any sliding engagement therebetween in the absence of sheets thus avoiding any unnecessary wearing of the magnetic head sensors.
A latitude of modification, change and substitution is intended in the foregoing disclosure, and in some instances, some features of the invention will be employed without a corresponding use of other features. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the spirit and scope of the invention herein.
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Sheet handling and counting apparatus comprising cooperating stripper shoes and feed rollers forming a feed nip which strips multiple fed sheets causing sheets to be delivered from a feed nip one at a time toward an acceleration nip. The orientation of the stripper shoe relative to the feed roller and the input tray provides excellent stripping action while preventing damage to the sheets being handled. The acceleration nip is formed by cooperating acceleration idlers and O-rings supported by acceleration rollers for accelerating sheets entering the acceleration nip to form a gap between adjacent sheets which aids in the counting of sheets. The stripper shoe is mounted within a clip which also serves to protect the forward end surface of the stripper shoe as well as providing a low friction guide surface engaged by the leading edges of sheets approaching the feed nip. The acceleration rollers drive freewheeling acceleration idlers provided on a common shaft with the feed roller by way of O-rings which further cooperate with dancer rollers to facilitate the feeding of light, thin documents into the feed nip. The O-rings increase the path length between the feed and acceleration nips facilitating the handling of sheets over a broad range of sheet length, measured in the feed direction. Feed idlers cooperate with the feed roller to provide an additional driving nip for directing sheets leaving the curved path leading out of the feed nip toward the acceleration nip. The O-rings provide a greater path length between the feed and acceleration nips to permit the handling of a wide range of sheet sizes with the need for any mechanical adjustment. Sheet feeding is accomplished without the need for an electromagnetic brake and clutch which devices are required in conventional apparatus.
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BACKGROUND OF THE INVENTION
The present invention concerns improvements in drilling equipment for use in horizontal drilling through rocks into strata of earth and sand.
Drilling of this kind below ground level is carried out for insertion of pipes for various purposes. Before blasting of tunnels, pipes thus are inserted into holes drilled one adjacent the other in the rock in an annular shape, to serve as casings for refrigerating pipes. The latter in turn serve the purpose of creating an artificial frost mass in the soil about the strata of earth that are later to be blasted away. The frost soil mass thus created in an artificial manner prevents water from flowing into the excavated tunnel, which saves times and effort.
Drilling equipment for use in such horizontal drilling operations comprises a drilling unit, said casing sections, a cutter head disposed at the forward end of the foremost casing as seen in the drilling direction, and drill rod sections which extend through the casing sections between the drilling aggregate and the cutter head and which are provided with an axial through channel feeding drill water to the cutter head.
The drilling operations involve several problems, however, particularly when the cutter head penetrates through rock into strata of earth and sand. If the air pressure inside the casing sections and the water pressure in the cutter head drill water channels are lower than the external ground water pressure, water and earth material will penetrate into said casing sections and channels all the way up to the drilling chamber. These displacements of material will in turn give rise to subsidence above the drilling space. In addition, material displacements also increase the risks of deviations from the intended drilling direction.
One has tried to eliminate this problem by using a cutter head, the diameter of which somewhat exceeds the internal diameter of the adjacent casing and which is mounted so as to close the forward casing end. Although this had a positive effect and partly prevented earth, sand, and water from penetrating, some other disadvantages arose in its stead. For instance, a cutter head of this size cannot be retrieved through the casing and used again. If, in addition, one fails to loosen the drill rod sections from the cutter head after completion of the drilling operation, which is not unusual, the drill hole cannot be used and a new hole must be started.
It is also possible to increase the air pressure inside the drill chamber for the purpose of preventing penetration of earth and water into the casing sections. However, this entails safety risks for the workmen and it is necessary to construct a sluice at the drill chamber entrance, which makes all transports to and from the drill chamber difficult and in addition time-consuming and expensive.
During the drilling operation the casing sections keep pace with the successive advancement of the cutter head through the strata of rock and earth. In rock drilling water does, however, seep into the drill hole also at the outside of these casing sections and flows into the drill chamber. When the cutter head reaches less compact strata of earth, the water is mixed with earth and sand, which aggravates the situation.
Attempts have been made to solve this problem by applying a seal in the form of an O-ring or a V-packing between the casing and the drill hole walls. These seals are, however, difficult to secure because of the movement of the casing in the working direction of the cutter head, and consequently the sealing effect is poor. On the other hand, if one succeeds in obtaining a comparatively good sealing effect, one instead has to face the disadvantage of accummulation of earth and sand forming plugs in front of the seal, which cause the casings to stick. In severe cases it might be necessary to drill a new hole for the casing adjacent the stuck one.
SUMMARY OF THE INVENTION
The present invention substantially eliminates the problems described above and this through very simple means. The invention is characterised by a combination of a metal seal and a seal consisting of a softer material, preferably rubber or plastics, these seals being positioned adjacent one another between the casing and the cutter head and arranged for cooperation to prevent ground level water and mud from entering into the casing.
In accordance with another characteristic of the present invention the drill rod positioned just behind the cutter head is provided with a one way valve arranged in the drill water channel and formed in a manner known per se by a valve ball arranged to be pressed against a valve seat by means of a compression spring.
Usually, this foremost drill rod has a drill water opening just behind the cutter head. In accordance with a further characteristic of the invention a seal is arranged behind this opening for the purpose of preventing drill water from flowing between the drill rod and the casing in the direction towards the drill chamber.
Through these means penetration of mud between casing and drill rod sections as well as into the drill water channels is efficiently prevented. When the drill fluid in these channels is cut off during the operation of jointing the drill rod sections, the one way valve positioned in the front drill rod will rapidly close the channel thereof, and consequently it becomes possible to work without impediments to connect a new drill rod.
An extra advantage gained with the combined seals is that it no longer is necessary to use a cutter head of the kind described above but instead an eccentric cutter head may be used which may be retrieved and thus re-used over and over again.
To prevent also penetration into the drill chamber of water and mud at the outside of the casing a pressure sleeve is arranged in accordance with the invention between the casing and the drill hole walls, said sleeve arranged to close off communication between the drill chamber and the annular channel existing between this casing and the drill hole wall, and into this annular channel debouches a conduit for supply of pressurized air or water.
In accordance with a preferred embodiment this pressure sleeve consists of an expansion ring arranged between two clamping rings and through which pass threaded bolts which likewise pass through an anchoring ring abutting against the drill chamber wall around the drill hole mouth, in addition to which between this anchoring ring and the adjacent clamping ring a distance sleeve is provided on each bolt. In this embodiment preferably at least one of the bolts is provided with a through channel to which may be connected the pressurized water or air supply conduit.
Owing to the pressure sleeve in accordance with the invention it is possible to apply a positive pressure to the external face about the casing. It is also possible to supply water from the drill chamber thereto. In this manner are eliminated the inconveniences of ground water penetration to the drill chamber resulting in material displacements in the less compact soil strata and subsidence therein, which would make drilling in the correct direction more difficult. At the same time advancement of the casing sections is facilitated because the latter slide forwards with less friction.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described more in detail in the following with reference to the accompanying drawings, wherein
FIG. 1 is a schematically illustrated general arrangement plan of a drilling installation for performance of drilling with the use of casing sections,
FIG. 2 is a vertical section through a casing with a cutter head arranged at the outer casing end,
FIG. 3 is a vertical section, shown on an enlarged scale, through a drill rod including a one way valve in the rod drill water channel in accordance with the invention,
FIG. 4 is a vertical section through a casing provided with a pressure sleeve in accordance with the invention, and
FIG. 5 is a vertical section through said pressure sleeve, shown on an enlarged scale.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The working enviroment is illustrated in FIG. 1. In a rock 1 below ground a drill chamber 2 has been blasted so as to extend close to a slope 3 of the rock. The purpose is to drill from this position a row of bores, one adjacent the other in an annular shape, through the rock wall 3 in a horizontal direction through less compact strata of earth consisting of soil, sand, clay and water, the ground level having been designated 4 and the ground water level 5, and into another rock ridge 1a positioned below ground. Casing sections 8 are arranged concentrically about the drill rod sections 7 of the drilling unit 6 so as to advance together with the cutter head 9 when the latter works itself successively forwards through the strata of earth.
As appears from FIG. 2, between the casing 8 closest to the cutter head 9 and the cutter head itself are arranged two seals positioned adjacent one another one outer metal seal 10 and an inner seal 11 of a softer material, preferably hard rubber or plastics. The metal seal 10 preferably is in the form of a hard-welding bead applied about the cutter head 9, the upper surface of the welding bead having been ground even and having a thickness calculated so as to make the welding bead fit well into the casing 8. The welding bead also serves to center and guide the cutter head 9 inside the casing 8. The softer seal 11 is preferably vulcanized to the cutter 9 in a peripheral groove 12 formed in the cutter head.
These two seals 10 and 11 provide, in combination, an extremely good sealing effect and prevent to a considerably high degree penetration of both coarser and finer particles and water into the casing. The combined effect of the seals also helps in slowing up wear compared to what would otherwise have been the case, had one used either a metal seal or a soft seal only.
The drill rod 7 is provided with a drill water channel 13 merging into a channel 14 passing through the cutter head 9, this channel 14 dividing into channel arms 15, 16, and 17. At its rear, the cutter head 9 is provided with a cleaning device 18. At its forward end, the drill rod 7 is provided with a drill water opening 19. Further to the rear in the joint between two drill rod sections 7 is provided a one way valve 20. This one way valve is in the form of a valve ball 21, as appears from FIG. 3, and arranged to be pressed against a valve seat 22 by a compression spring 23.
When mounting the one way valve 20 the valve ball 21 is placed in position in the valve seat 22 at one end of a drill rod 7, the compression spring 23 is applied externally thereof, a jointing sleeve 24 screwed onto the drill rod end, whereupon finally the end of another drill rod 7 is screwed into the jointing sleeve 24 until the drill rod ends abut against one another. The compression spring 23 is then compressed somewhat, whereby the valve ball 21 will abut against the valve 22 while exerting a certain pressure thereon.
In accordance with the invention it is suitable to position on the outside of the jointing sleeve 24, a seal 25, preferably consisting of hard rubber which upon application of a casing 8 about the jointing sleeve will abut sealingly against the inner face thereof.
During the drilling operation water will be flushed through the channels 13 in the direction of arrow 26, the water having a pressure exceeding the pressure with which the valve ball 21 presses against the valve seat 22. The stream of water will continue out through the channel arms 14, 15, 16, and 17 of the cutter head 9. Some water will flow out through the drill water opening 19 in the drill rod 7 and fill the space 27 existing between the drill rod 7 and the casing 8, which space is limited and closed by the double seal 10, 11 at one end and the seal 25 on the joint sleeve 24 at the opposite end. A positive pressure will exist in this space 27. This arrangement excludes every possibility of soil, sand, or water entering into the casing 8.
When it is time to joint drill rod sections 7 and casing sections 8, the cutter head 9 is stopped, and the drill water supply closed off. As a result the one way valve 20 will start functioning immediately, i.e. the spring 23 presses the ball 21 against the seat 22 which means that the drill water channel 13 ahead of the one way valve 20, as well as the channel arms 14, 15, 16, and 17 and the space 27 will be kept filled with water and thus constantly prevent ground water mixed with earth, sand, drill dust and other particles from entrance into the casing through these passageways. When the jointing operation is completed it is therefore possible to resume the drilling immediately without preliminary rinsing of the entire system.
In the bore opening 28 in the rock 1 is inserted concentrically about the casing 8 a guide tube 29 (see FIG. 4) serving to retain the direction of the casing at the casing exit from the rock. In accordance with the invention furthermore a pressure sleeve 31 is disposed between the casing 8 and the wall 30 of the drill opening 28, said sleeve 31 arranged to close the annular channel 32 formed between the casing and the walls of the drill hole.
In accordance with the embodiment illustrated in the drawings the pressure sleeve consists of an expansion ring 33 disposed between two clamping rings 34. An anchoring ring 26 abuts against the wall 35 of the drill chamber 2. Threaded bolts 37 pass through the expansion ring 33, the clamping rings 34, and the anchoring ring 36. Between the latter and the adjacent clamping ring 34 is arranged a distance sleeve 38 on each bolt 37. When nuts 39 are tightened against the anchoring ring 36 the expansion ring 33 will swell out between the clamping rings 34, thus closing off the annular channel 32 from communciation with the drill chamber 2.
In accordance with the invention is furthermore provided a conduit means 40 supplying pressurized air or water and connected to the annular channel 32. In accordance with one embodiment of the invention one of the bolts 37 is then provided with a through channel 41 debouching into the annular channel, the conduit 40 communicating with this bolt.
By flushing water into the annular channel 32 at a pressure exceeding the pressure of the external ground water are efficiently prevented displacements of material in the strata of earth and the risk of subsidence therein is eliminated. As a consequence hereof it becomes easier to maintain the intended direction of drilling. The water thus forced into the channel also excludes formation of plugs in the annular channel 32 while at the same time serving as a lubricating means about the casing 8.
The invention is not limited to the embodiment as described and illustrated but may be constructively altered in a variety of ways within the scope of the appended claims. For instance, it is possible to attach the double seal against the inner face of the casing 8 instead of on the cutter head 9. Neither is there anything to prevent the seals 10 and 11 to change place, i.e. to position the rubber seal in the outer position and the metal seal in the inner position.
The one way valve 20, the structure of which is known per se, may of course be designed in a different manner and still fulfil its function in accordance with the inventive idea.
The hard rubber seal 25 need not be placed on the jointing sleeve 24 but may be attached about the drill rod 7 immediately behind the drill water opening 19. The space 27 thus becomes smaller and will be filled with water more rapidly.
Furthermore, other modifications of the pressure sleeve are possible, and the connection of the conduit 40 to the annular channel 32 may of course be through another means than a bolt 37.
It is also possible to inject into the annular channel 32 some medium other than water or air, e.g. some gas containing an ingredient which deposits on the rock walls and successively fills out crevices therein, thus preventing ground water from flowing into the annular channel.
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Improved sealing means in rock drilling equipment of the kind comprising casing sections positioned between the drilling unit and the cutter head and housing the drill rod sections. A combined seal consisting of a metal part and a resilient part is positioned between the casing and the cutter head to prevent water and mud from penetrating into the casing. In addition, sealing means are provided to prevent drill water from flowing between the drill rod and the casing in the direction towards the drill chamber, and further means are provided to close off communication between the drill chamber and the annular chamber between the casing and the drill hole wall.
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FIELD OF THE INVENTION
[0001] This invention relates to cartons. More specifically, this invention relates to an improved beverage carton and associated blank and carton sleeve that improves production rates and efficiencies.
BACKGROUND OF THE INVENTION
[0002] In the marketing of soft drinks, beer and other beverages, such retail consumer products are commonly sold in cans which are grouped together in six or 12 packs. Particularly in the case of 12 can packs, the cans are commonly packaged in cartons to make it easier to handle the product for the wholesaler and the retailer as well as for the retail consumer.
[0003] There are any number of different types of can cartons. One particular type of carton that has found significant commercial success over the years is referred to as a “wrap around” carton. In a wrap around carton, a number of cans, typically 12, are wrapped in a paperboard box or carton that includes top and bottom wall panels, sidewall panels and end flaps on each end. The end flaps at each end of the carton are sealed one to the other, thereby providing a closed or sealed package or carton for the cans.
[0004] A common carton production method involves converting paperboard into carton blanks and then into folded cartons which are eventually erected and filled with the beverage cans. The fabrication of beverage cartons typically begins with paperboard being drawn in a web from a roll of paperboard. Commonly, one surface of the paperboard is printed with a desired graphic design. The paperboard web is then die cut into multiple individual carton blanks. The printed carton blanks are then transferred typically within the same carton manufacturing facility, to a folder/gluer machine where each carton blank is folded and glued into a flattened sleeve or fill-ready carton configuration. The flattened cartons or sleeves are packed and then palletized for shipment to a customer such as a soft drink canner or the like.
[0005] During the conversion of the paperboard into a carton sleeve, the web of paperboard commonly passes between various counter rotating rollers including an impression roller and a stripper drum. Typically, a carton blank includes certain holes or apertures and after each hole is die cut in the paperboard, the paperboard material must be removed from the hole portions of the web as scrap. Such scrap pieces of paperboard are removed by a series of pins arranged on the stripper drum and appropriately configured for the particular carton blank in production. Optimally, the pins puncture the scrap portions of the paperboard and continued movement of the paperboard web and rotation of the stripper drum pulls or strips the scraps from the web.
[0006] However, one inherent requirement in the stripping process is that the pins on the stripper drum be appropriately aligned with the scrap portions of the paperboard web for removal. If the pins do not puncture the scrap portion of the web, the scrap is not removed by the stripper drum and an operator must manually remove the scrap downstream from the stripper drum, for example, by punching the scrap with a screw driver or other tool. Because of the size and processing speed of the converting equipment, it is often difficult to accurately and precisely align the stripper drum with the web for consistent removal of the scrap by the stripper drum. The manual removal of the scrap results in a very inefficient beverage carton sleeve production process. The die cutting machines cannot operate at peek production speeds because of the consistent need to manually remove the scrap from the die cut carton blanks.
[0007] For example, one known type of carton blank is disclosed in U.S. Pat. No. 5,292,059, which is incorporated herein by reference in its entirety. The carton blank shown in the '059 patent includes a number of generally triangular-shaped apertures identified by reference numeral 86 in that patent. Such a carton blank is generally shown in FIG. 1 herein. The triangular-shaped apertures according to the '059 patent assist in providing a carton having end walls of increased flatness so that it can be utilized as a billboard, display or advertising space while still maintaining adequate structural integrity for the carton.
[0008] However, one shortcoming of the carton blank shown in the '059 patent and FIG. 1 herein is that the triangular apertures are sized and configured so that the scrap is not consistently, reliably and efficiently removed from the carton blank during production. Therefore, production of carton blanks of this type are significantly more slower because the machines on which the paperboard is converted to produce such carton blanks cannot run at peak speeds due to the fact that the scrap from the triangular apertures often must be manually removed.
SUMMARY OF THE INVENTION
[0009] As such, there is a need for an improved carton blank and sleeve style carton design which enables the carton manufacturing process to be more efficient and deliver higher production rates.
[0010] Moreover, there is a need for such a carton blank and carton design which provides certain advantages and benefits of known carton designs without the need for repeated manual removal of scrap from apertures in the carton blank during the production process.
[0011] These and other objectives of this invention have been attained by an improved carton and blank design in which the paperboard web can be processed at or near peak production rates into carton blanks and without the need for manual removal of scrap from apertures in the carton blank. Specifically, the carton blank according to this invention can be processed at or near peak production rates of about 625 feet per minute which is a 30 percent or more increase in production rates achieved for similar carton blanks, such as those shown in U.S. Pat. No. 5,292,059 and the like. The increase in production rates is principally obtained because the stripping pins on the stripper drum consistently and reliably puncture and remove the scrap from apertures in the die cut carton blank thereby alleviating the need to slow or stop the machine for manual removal of the scrap.
[0012] In one presently preferred embodiment of this invention, a tubular carton sleeve is adapted to be formed into a carton for holding beverage containers. The carton sleeve is erected and formed from a carton blank that includes a top wall and a pair of sidewalls that are each foldably joined to the top wall. A pair of bottom lap panels are each foldably joined to one of the sidewalls and are adapted for folding relative to the respective sidewalls and joined to each other in overlapping relation to form a bottom wall of the resulting carton. Major end flaps are foldably joined to an end of each of the sidewalls and minor end flaps are likewise foldably coupled to an end of the top wall or bottom wall panels. When the carton is erected, the major and minor end flaps are folded relative to the respective side, top and bottom walls to form end walls of the carton. A plurality of gussets are each foldably joined to one of the major end flaps and an adjacent one of the minor end flaps. The gussets foldably interconnect the major and minor end flaps and are tucked in between those end flaps when the carton is formed. A preferably rectangular bevel panel is formed between the minor end flaps and the associated top and bottom wall adjacent to the gussets. The bevel panel is supported by the adjacent beverage cans when the carton is filled and therefor contributes to the tightness of the carton and the prevention of undesirable crushing of the corners of the carton.
[0013] Advantageously, gusset holes which are formed at a juncture of the top or bottom walls and the adjacent sidewalls in part define the gussets. The gusset holes are preferably generally trapezoidal-shaped to provide for increased surface area of the gusset hole relative to prior art configurations. The trapezoidal-shaped larger gusset holes provide for a more consistent and reliable removal of the carton material scrap from the gusset hole during production of the blank. The trapezoidal-shaped gusset holes are on the average 27 percent larger than triangular-shaped apertures in prior art carton blanks thereby providing for an increased area for the stripper pins on the stripper drums to puncture the scrap material in the gusset hole for removal. As such, even if the paperboard web is not precisely aligned with the location of the stripper pins on the stripper drum, the web can be processed at or near maximum speeds in the production facility because the stripper pin reliably and consistently removes the scrap from the gusset holes, unlike prior art carton blank designs.
[0014] Therefore, the advantages and benefits of certain known wrap around or sleeve style tubular cartons can be achieved with the carton blank, tubular carton sleeve and associated beverage carton of this invention while still allowing for maximum production efficiencies and process rates by avoiding the need for manual removal of the scrap from apertures, gusset holes or the like in the carton blank.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The objectives and features of the invention will become more readily apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
[0016] [0016]FIG. 1 is a plan view of a prior art carton blank;
[0017] [0017]FIG. 2 is a plan view of a carton blank according to a presently preferred embodiment of this invention;
[0018] [0018]FIG. 3 is a perspective view of a stripper pin on a stripper drum rotating to intersect the scrap material in a gusset hole of a carton blank according to one presently preferred embodiment of this invention;
[0019] [0019]FIGS. 4A and 4B are sequential views of the stripper pin removing scrap from the gusset hole of the carton blank in FIG. 3;
[0020] [0020]FIG. 5 is a perspective view of a tubular carton sleeve formed from the carton blank of FIG. 2;
[0021] [0021]FIG. 6 is a partially broken away perspective view of one end of the tubular carton sleeve of FIG. 5 being folded into an end wall of the carton;
[0022] [0022]FIGS. 7A and 7B are enlarged partial plan views of trapezoidal-shaped gusset holes from a carton blank according to one presently preferred embodiment of this invention; and
[0023] [0023]FIG. 8 is a view similar to FIGS. 7A and 7B of a triangular-shaped aperture in a prior art carton blank.
DETAILED DESCRIPTION OF THE INVENTION
[0024] A presently preferred embodiment of a carton blank 10 according to the present invention is shown in FIG. 2 and includes a top wall 12 . Sidewalls 14 , 14 are foldably joined to the side edges of the top wall 12 along fold lines 16 , 16 . Bottom lap panels 18 , 18 are foldably joined respectively to the sidewalls 14 , 14 along fold lines 20 , 20 . A carrying handle 22 is provided for the carton and includes a pair of flaps 24 , 24 . The details of such a carrying handle 22 are disclosed for example in U.S. Pat. No. 5,106,014 issued Apr. 21, 1992, which is hereby incorporated by reference.
[0025] Major end flaps 26 , 28 are foldably joined to the end edges of sidewalls 14 , 14 along fold lines 30 , 32 , respectively. Minor end flaps 34 , 34 are foldably coupled respectively to bevel panels 36 , 36 at the end edges of the top wall 12 along fold lines 38 , 38 and 40 , 40 . Likewise, partial minor end flaps 42 , 42 , 42 , 42 are foldably joined respectively to partial bevel panels 44 , 44 , 44 , 44 at the end edges of the bottom lap panels 18 , 18 along fold lines 46 , 46 , 46 , 46 , and 48 , 48 , 48 , 48 .
[0026] Gussets 50 interconnect the adjacent end flaps 26 and 34 ; 28 and 34 ; 26 and 42 as well as 28 and 42 . Since all of the gussets 50 are virtually identical, only the specific features of the gusset 50 will be described here in detail. With particular reference to FIGS. 2 and 5, the gusset 50 is foldably joined to the minor end flaps 42 , 34 along a fold line 52 . The opposite end of the gusset 50 is foldably joined to the major end flaps 26 , 28 along a fold line 54 .
[0027] A rectangular bevel panel 36 , 44 is defined between the fold lines 46 , 48 , and 38 , 40 respectively. Bevel panel 36 is foldably joined to the top wall 12 and to the minor end flap 34 . Likewise, bevel panel 44 is foldably joined to the bottom lap panels 18 and to the partial minor end flaps 42 .
[0028] Specifically, in one presently preferred embodiment the carton blank 10 includes gusset holes 74 that are trapezoidal in shape and likewise provide an increased surface area relative to the prior art blank 11 having triangular apertures 13 (FIG. 1) for more reliable removal of scrap 72 (FIGS. 4A and 4B) from the gusset hole 74 during production of the carton blank 10 . In one presently preferred embodiment, the gusset hole 74 is trapezoidal-shaped and the gusset holes 74 a in the carton blank 10 proximate the top wall 12 include first and second edges 76 , 78 that are each generally parallel to one another and third and fourth edges 80 , 82 that are obliquely oriented relative to each other and relative to the first and second edges 76 , 78 . These gusset holes 74 a in one presently preferred embodiment have a surface area of about 0.4554 square inches. Additionally, in another presently preferred embodiment the gusset holes 74 b proximate the bottom lap panels 18 of the carton blank 10 have first and second edges 84 , 86 that are generally parallel to one another and a third edge 88 is generally perpendicular to the first and second edges 84 , 86 and a fourth edge 90 is obliquely oriented relative to the first, second and third edges 84 , 86 , 88 . The gusset holes 74 b proximate the bottom lap panels 18 have a surface area of approximately 0.4293 square inches. The trapezoidal-shaped gusset holes 74 a , 74 b according to this invention are advantageously larger than the triangular-shaped apertures 13 in the prior art carton blank 11 of FIG. 1. More specifically, the triangular-shaped prior art aperture 13 of FIG. 8 has a surface area of approximately 0.3487 square inches. As such, the gusset hole 74 b of FIG. 7A is approximately 23 percent greater than that of the prior art triangular-shaped apertures 13 of FIG. 8; whereas, the trapezoidal-shaped gusset hole 74 a of FIG. 7B is 31 percent larger than the triangular-shaped aperture 13 of the prior art in FIG. 8. On the average, the gusset holes 74 a , 74 b of FIGS. 7A and 7B of this invention are 27 percent larger than the prior art aperture 13 of FIG. 8. While the gusset holes 74 a , 74 b are shown as being different trapezoidal shapes and sizes, the gusset holes 74 may be the same configuration and size and preferably trapezoidal and as large as practically possible to increase the likelihood of removing the scrap. The advantageous size and configuration of the gusset holes 74 a , 74 b result in an increase in production because the web 10 a moves at a rate of approximately 625 feet per minute which is a 30 percent or greater increase relative to production rates for the prior art carton blank 11 of FIG. 1. As such, the carton blank 10 configuration according to this invention and shown in FIG. 2 provides a significant increase in production rate and advantage over known prior art designs due in large part to the configuration of the gusset holes 74 a , 74 b.
[0029] To complete the basic elements of the carton, one or more outlet ports 56 are each defined by severance lines 58 as shown in FIG. 2. The severance lines 58 are formed in at least one of the sidewalls 14 . The outlet port(s) 56 provide(s) a dispensing means for dispensing the beverage cans from the carton. A preferred embodiment in the outlet port 56 is disclosed U.S. Pat. No. 5,249,681, issued Oct. 5, 1993 and hereby incorporated by reference.
[0030] To form a tubular carton sleeve 60 from the carton blank 10 , the bottom lap panels 18 , 18 are partially overlapped onto one another and glued together, typically on a folder-gluer machine as is well known in the art. The sleeve 60 can then be collapsed about fold lines 16 and 20 for storage and/or shipping.
[0031] To form the carton from the sleeve 60 , the minor end flaps 34 , 42 , as viewed in FIGS. 5 and 6, are pivoted and folded into the positions shown in FIG. 6. This action causes the bevel panels 36 , 44 to swing inwardly together with each gusset 50 into the respective positions as shown in FIGS. 5 and 6. Following this, the major end flap 26 is folded inwardly along the fold line 30 and major end flap 28 is then folded inwardly along fold line 32 until the major end flaps 26 , 28 overlap and are glued together to form end walls. Once this is completed on both ends of the sleeve 60 , the carton is formed. The articles are loaded into the carton through the open end or ends of the carton.
[0032] It should be recognized that as used herein, the terms “top”, “bottom” and “side” with respect to the various carton walls or components are relative terms, and that the carton and/or its contents may be re-oriented as necessary or as desired. Further, rather than the bottom wall being formed from separate lap panels 18 , 18 , it will be recognized that the carton blank 10 may be rearranged whereby some other panel is formed as a composite from lap panels.
[0033] One advantage of this invention is that the end walls of the completed carton have large flat surfaces and that the carton still maintains adequate integrity due to the bevel panels 36 , 44 at the ends of the top wall 12 and bottom wall. The endwall enlarged flat surfaces are useful as space for carrying printing such as an advertisement, trademark, and other information.
[0034] A principal advantage of this invention is demonstrated in FIGS. 3, 4A, 4 B, 7 A, 7 B and 8 . Once a web of paperboard 10 a is die cut, it commonly passes between various counter rotating rollers and drums. One such drum is a stripper drum 62 having a number of stripper pin assemblies 64 with pins 66 projecting from the outer circumference of the drum 62 . Each stripper pin is mounted to the drum 62 on a base 68 and a movable sleeve 70 surrounds the pin 66 .
[0035] Referring to FIGS. 3, 4A and 4 B, as the die cut paperboard web 10 a passes in the direction of arrow A past the stripper drum 62 rotating in the direction of arrow B, the stripper pins 66 are spaced and configured on the stripper drum 62 so that one of the pins 66 puncture the scrap portion 72 of the paperboard 10 a formed in the gusset hole 74 . Once the stripper pin 66 punctures the scrap 72 as shown in FIG. 4A, continued movement of the paperboard web 10 a and the stripper drum 62 separates the scrap 72 and pin 66 from the paperboard web 10 a thereby exposing the gusset hole 74 as shown in FIG. 4B. Due to the centrifugal forces of the rotating stripper drum 62 , the movable sleeve 70 slides along the stripper pin 66 to project in the direction of arrow C and thereby dislodge the scrap 72 from the pin 66 for disposal. As such, upon subsequent rotation of the stripper drum 62 , the stripper pin 66 is free to puncture scrap 72 in a subsequent die cut portion of the paperboard web 10 a.
[0036] The above-described removal process for scrap 72 from die cut holes or apertures in the carton blank 10 is generally the desired objective of many carton blank production facilities and paperboard converters. However, because of the design of prior art carton blanks 11 such as those shown in FIG. 1, frequently the stripper pin does not puncture the scrap portions of the die cut blank and, consequently, does not remove the scrap from die cut holes or apertures in the paperboard web. As a result, the process must be halted or interrupted so that an operator manually punctures the scrap from the die cut holes with a screw driver or the like. The misalignment of the stripper pin 66 relative to the scrap may be the result of a number of factors including misalignment of the web relative to the stripper drum 62 , inaccurate placement of the stripper pin assemblies 64 on the stripper drum 62 for a given die cut configuration or the like. Additionally, wobble or loosely mounted stripper pins 66 are commonly utilized so that dust or other foreign matter can be easily and/or automatically ejected from the stripper pin assembly 64 to prevent clogging, jamming or the like. Such inherent movement in the stripper pin 66 may also create inaccuracies in the puncturing of the paperboard web.
[0037] Nevertheless, the carton blank 10 according to one embodiment of this invention overcomes these problems and allows for maximum or near peak production rates because scrap 72 in particular apertures in the gusset hole 74 is consistently and reliably punctured by the stripper pins 66 for removal thereby alleviating the requirement for interruption of the process or manual removal of the scrap.
[0038] From the above disclosure of the general principles of the present invention and the preceding detailed description of at least one preferred embodiment, those skilled in the art will readily comprehend the various modifications to which this invention is susceptible. Therefore, I desire to be limited only by the scope of the following claims and equivalents thereof.
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An improved sleeve style beverage carton can be processed at or near peak production rates for carton blanks and without the need for manual removal of scrap from apertures in the carton blank. The increase in production rates and efficiency is principally obtained because the stripper pins on the stripper drum used in producing the carton blank consistently and reliably puncture and remove the scrap from apertures in the die cut carton blank thereby alleviating the need to slow or stop the machine for manual removal of the scrap. Advantageously, gusset holes which are die cut in the carton blank are preferably generally trapezoidal-shaped to provide for increased surface area of the gusset hole relative to prior art configurations. The trapezoidal-shaped larger gusset holes provide for a more consistent and reliable removal of the carton material scrap from the gusset hole during production of the blank.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to portable hydraulic stake puller. More specifically, the present invention relates to a portable hydraulic stake puller useful for removing tent stakes, ground rods, fence posts, sign posts, and the like.
2. Description of the Related Art
Pulling tent stakes out of the ground can be a task more difficult than many people realize. This is mostly because, in the world of commerce, tent stakes are not the short thin rods that are used for camping tents. Instead, when used for large commercial tents and structures, such as those rented for parties, large sales events and other special events, tent stakes are typically one inch to one and one quarter inch diameter rods (or larger) constructed of, for example, reinforcing rods such as is used for concrete, carbon steel, or wood. These stakes have a length that is usually in excess of two feet.
A hammering device is often used to pound this type of stake into asphalt paving or hard ground. Such a driven stake cannot be pulled from the ground by hand by merely loosening it with a few blows against its exposed top, or by turning the top with a turning device such as a wrench. Removal of these types of stakes is very difficult.
Perhaps the most similar task to pulling such large tent stakes is that of pulling railroad tie spikes. In that situation, although railroad tie spikes are not as long as large tent stakes, and the removal force potentially less, the difficulty is similar. The major difference between removing spikes from railroad ties and pulling large tent stakes from the ground is the availability of powerful machines for easy removal. On the railroad, there are machines movable only along the railroad tracks which remove the spikes. Unfortunately, there is a lack of means for providing a powerful tent stake pulling machine, often times in remote locations with poor access, and no or only limited access to power sources.
For example, conventional railroad spike pullers use pneumatic power. This requires a nearby source of power, of significant weight, and hoses which must be moved between the locations of the spikes to be removed. Such an arrangement is extremely difficult to obtain at typically isolated sites at which large tents are erected.
OBJECTS AND SUMMARY OF THE INVENTION
It is an object of the present invention to provide a portable hydraulic stake pulling apparatus which overcomes the foregoing problems.
It is a further object of the present invention to provide a portable hydraulic stake pulling apparatus which has its own integrated power source and which can be operated by one person is swift and easy precision.
It is a further object of the present invention to provide a portable hydraulic stake puller which can be positioned to grab a stake for removal with a simple twist of the handles, allowing rapid removal of multiple stakes.
It is a further object of the present invention to provide a portable hydraulic stake puller which can be easily and readily loaded into and transported in a truck.
It is a further object of the present invention to provide a portable hydraulic stake puller which can be swiftly and readily adapted for use in removing fence posts, or other items to be withdrawn from a surface.
Briefly stated, the present invention provides a portable hydraulic stake puller powered by an engine. The lifting action is produced by the extension of a hydraulic cylinder that extends to raise a jaw assembly. The jaw assembly pivots, while being raised, to grab the stake. A grab hook is also provided for use to extract similar items such as fence posts, signposts, grounding rods, spikes, pins, pipes, etc. The jaw or chain tension is released when the control lever is released at any height of the stroke. Squeezing the control lever can again attain grip. The gripping action of the jaw is attained by at least friction. The entire lift assembly returns to the neutral position, when the control lever is released, by the use of springs. The hydraulic stake puller is mounted on wheels and controlled via handles.
According to an embodiment of the present invention, there is provided a hydraulic stake pulling apparatus, comprising, an engine mounted on a frame, a hydraulic pump driven by the engine, a hydraulic fluid valve selectable between an open position and a neutral position, the open position communicating hydraulic fluid to a hydraulic cylinder, a jaw attached to the hydraulic cylinder, the jaw having a guide slot for positioning the stake therein, and a control lever for selecting one of the open position and the neutral position, whereby, in the open position, the hydraulic cylinder is actuated, driving the jaw to lift the stake.
According to another embodiment of the present invention, there is provided a hydraulic stake pulling apparatus further comprising, a lifting tube, attached to the hydraulic cylinder, positioned between the jaw and the hydraulic cylinder, and a grab hook mounted on the lifting tube, whereby an attachment member may be used to link the grab hook with the stake, thereby removing the stake when the lifting tube is raised by the hydraulic cylinder.
According to another embodiment of the present invention, there is provided a hydraulic stake pulling apparatus, wherein the hydraulic cylinder is mounted in and guided by a tube running in the lifting direction of the hydraulic
According to another embodiment of the present invention, there is provided a hydraulic stake pulling apparatus, wherein the jaw is at least hard faced, providing improved friction with the stake during a lifting operation of the jaw.
According to another embodiment of the present invention, there is provided a hydraulic stake pulling apparatus further comprising, at least one spring member, and the spring member providing resiliency to return the jaw to an original position after the control lever is released and the valve is in the neutral position.
According to another embodiment of the present invention, there is provided a hydraulic stake pulling apparatus, wherein the engine is a gasoline engine.
According to another embodiment of the present invention, there is provided a hydraulic stake pulling apparatus further comprising, a gear box or hydraulic mechanism controllably linking and connecting the engine with the hydraulic pump.
According to another embodiment of the present invention, there is provided a hydraulic stake pulling apparatus further comprising, further comprising a flexible coupling connecting the engine with the hydraulic pump.
According to another embodiment of the present invention, there is provided a hydraulic stake pulling apparatus further comprising, a cover encasing at least the hydraulic pump and the valve, whereby the hydraulic pump and the valve receive protective cover from environmental damage.
According to another embodiment of the present invention, there is provided a hydraulic stake pulling apparatus, wherein the jaw is at least one of being mounted partially pivotably and mounted partially slidably on the lifting tube.
According to another embodiment of the present invention, there is provided a hydraulic stake pulling apparatus further comprising, at least two wheels attached on the frame, at least two handles attached to the frame, and the control lever is mounted on one of the handles.
According to another embodiment of the present invention, there is provided a method for removing stakes, comprising, driving a hydraulic pump with an engine, connecting a hydraulic cylinder to a valve on the hydraulic pump, opening the valve with a control lever, the opening causing the hydraulic cylinder to extend, providing a jaw on the hydraulic cylinder, the jaw having a guide slot for inserting the stake, removing the stake inserted in the guide slot when the jaw is raised by the hydraulic cylinder.
The above, and other objects, features and advantages of the present invention will become apparent from the following description read in conjunction with the accompanying drawings, in which like reference numerals designate the same elements.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view drawing of the hydraulic pulling device according to the present invention.
FIG. 2 is a detailed drawing of a lift tube of the hydraulic pulling device of FIG. 1 .
FIG. 3 (A) is a plan view of the lifting jaw in a neutral position according to the present invention.
FIG. 3 (B) is a plan view of an alternate embodiment of the lifting jaw according to the present invention.
FIG. 4 is a partial front view of the hydraulic pulling device of FIG. 2 in a partially extended position.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, the present invention is a hydraulic powered stake puller 1 that is able to be operated by a single user. An engine 3 , mounted on a frame 13 , provides the necessary power to operate the unit. Engine 3 is preferably at least a 4 horsepower engine (gasoline engine), and more preferably at least a 5.5 horsepower engine, operating at about 3600 rpm. Stake puller 1 is preferably mounted on wheels 5 , allowing for flexibility and portability for use in many diverse stake pulling situations.
Furthermore, wheels 5 are optionally driven by engine 3 by any conventional self-propel means. For example, the user engages the self-propel means by gripping a control lever 7 on one of handle members 9 . Moreover, wheels 5 are optionally braked by any conventional means, such as direct restriction of the wheel itself or by mechanical locking of a wheel axle 11 .
A hydraulic pump 15 , mounted on frame 13 , is driven by engine 3 . A valve 17 releases hydraulic fluid pressure generated by hydraulic pump 15 into a hydraulic line 19 . Valve 17 is opened and closed through control lever 7 mounted on one of handle members 9 .
Additionally referring now to FIGS. 2-4, hydraulic line 19 attaches to a hydraulic cylinder 21 and is positioned within an inner tube member 23 . Inner tube member 23 operates to support and protect hydraulic cylinder 21 during operation.
A base member 22 supports hydraulic cylinder 21 and inner tube member 23 , and operates to support the unit in operation and spread the pressure during operation over a broader surface area of the ground. Base member 22 may be in any convenient shape but must be strong enough to prevent bending during use and provide sufficient support for proper operation.
Hydraulic fluid pressure, introduced into hydraulic line 19 through valve 17 , causes hydraulic cylinder 21 to extend and move in the direction indicated by arrow A in FIG. 4 .
Hydraulic cylinder 21 includes an extendable member having an end attachment part (not shown). A telescopic lifting tube 25 , fits over and guidably slides around inner tube member 23 , and is attached to the end attachment part of hydraulic cylinder 21 with a first attachment member 46 .
Telescopic lifting tube 25 provides protection to hydraulic cylinder 21 during use and transfers the force from hydraulic cylinder 21 to the jaws or lifting member during lifting, as will be explained.
At the bottom of inner tube member 23 , a second attachment member 47 extends through inner tube member 23 , and serves to secure the bottom ends of a pair of spring members 43 , 43 , as will be explained.
A pair of spring tubes 45 , 45 extend along the outside of lifting tube 25 and guide spring members 23 during operation and use.
A pair of support brackets 49 , 49 extend away from the outside of lifting tube 25 , above respective spring tubes 45 , 45 . A pair of third attachment members 48 , 48 operate to join top portions of spring members 43 , 43 to support brackets 49 , 49 . Spring members 43 , 43 are respectively adjustably retained between third attachment members 48 , 48 and second attachment members 47 , 47 . Third attachment members 48 , 48 are adjustable relative to support brackets 49 , 49 to adjust the spring tension of spring members 43 , 43 .
During operation, lifting tube 25 is raised by hydraulic cylinder 21 pressing against the resiliency of spring members 43 , 43 operably retained in spring tubes 45 , 45 . During downward operation, spring members 43 , 43 return lifting tube 25 (by elastic urging), in a direction indicated by arrow B in FIG. 4 to its starting position (shown in FIG. 2 ). This operation occurs when control lever 7 is released, allowing valve 17 to return from an open position to a neutral position.
A pair of support members 27 , 27 extend outward away from lifting tube 25 and optionally retain and support a jaw 29 for removal of stakes. A grab hook 28 is preferably mounted on lifting tube 25 above support members 27 , 27 . Grab hook 28 may be alternatively positioned anywhere along the length of lifting tube 25 or even on support members 27 , 27 themselves dependant upon customer need.
Grab hook 28 may be particularly useful when jaw 29 cannot reach, access, or grip the stake to be removed. In these cases, a chain or sling (not shown) may be attached to grab hook 28 and then to the stake or other item to be raised. For example, while removing a 4×4 fence post from the ground, a sling or chain may be wrapped around the post and then hooked to grab hook 28 . During lifting, the sling or chain may be readjusted around the post as it rises from the ground. Thus, the present invention provides safe and easy removal a plurality of items useful to customers.
A first set of lifting members 50 is mounted on frame 13 in a rear position and a second set of lifting members 51 is mounted on frame 13 in a front position proximate lifting tube 25 . Lifting members extend from frame 13 and allow an operator or a pair of operators to lift hydraulic stake puller 1 into, for example, a pick-up truck for easy transportation to a distant job cite.
Jaw 29 is removably mounted on lifting tube 25 , between supports 27 , 27 . In the present embodiment a bolt (shown but not numbered) pivotably retains jaw 29 . A choice of jaw sizes is available depending upon the particular application required by the client. Jaw 29 is preferably partially pivotably mounted on lifting tube 25 . This pivoting action allows jaw 29 , having been placed around a stake, to pivot upon lifting and trap the stake between edges in a guide slit 31 .
In a first embodiment of jaw 29 , shown in FIG. 3A, guide slit 31 , may have roughened or hardened surfaces 33 to improve grip during pulling and minimize damage during extended ware.
In a second embodiment of jaw 29 , shown in FIG. 3B, jaw 29 may be optionally provided with one fixed head 35 and one adjustable head 37 . Adjustable head 37 is adjustable relative to fixed head 35 thereby allowing for varying dimensions of guide slot 31 . Movement of adjustable head 37 , relative to fixed head 35 , may be attained by any convenient means, such as a screw member 39 and locking nut 41 .
Operation of the Device
The stake puller according to the present invention is wheeled to a location where stakes are required to be removed. The stake is inserted into the guide slot of the jaw and secured. The stake maybe secured by a simple twist of the stake puller machine, lodging the stake within the guide slit, or by attaching to a hook.
The user then squeezes the control lever, opening the valve, whereby the hydraulic pump generates pressurized hydraulic fluid through the hydraulic fluid line to the hydraulic cylinder. The hydraulic cylinder raises the lifting tube to which is attached the jaw. The surfaces of the jaw engage and hold the stake through rotation while the lifting tube raises. When the user releases the control, the valve returns from an open position to a neutral position. The spring members then guide the lifting tube and jaw to their starting positions.
Should the stake, such as a ground rod, be longer than the lifting capacity of the stake puller (which, in a preferred embodiment of the present invention, is at least 20 inches), once the stake puller removes the stake through its lifting capacity, the user releases the control lever, causing the lifting tube and jaw to return to the starting position. The user may then insert the ground rod into the guide slot of the jaw, and repeat the lifting process until the desired length of the rod is removed. As noted, alternatively a sling may be attached to the item to be removed and attached to the grab hook and alternatively readjusted after each pull stroke until the item is completely removed.
Alternative embodiments of the present invention are envisioned. For example, a hydraulic or mechanical vibration mechanism may be added to the stake puller, causing at least the jaw of the puller to vibrate. Such vibrations will assist in loosening the stake as it is being pulled.
Additionally, fold-stabilizing legs attached to either base member 22 or other member of hydraulic stake puller 1 and brace the device against twisting or shifting on an unstable surface during stake removal.
The present invention is preferably designed with at least a 4 horsepower gas engine, and more preferably at least about a 5.5 horsepower engine. However, any effective type of engine may be used to power the hydraulic pump. Diesel or electric engines may be substituted, so long as they are able to support the operation of the hydraulic pump.
The jaw of the present invention is shown as a V-type or C-type claw member. However, any suitable gripping means may be used, as long as it is adequate to grip and retain the stake as it is being removed. The present simple design provides great convenience and speed to the user, but the alternative embodiments with adjustable jaws, clamps, or hooks are readily adaptable by a user according to need.
Although only a single or few exemplary embodiments of this invention have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiment(s) without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the spirit and scope of this invention as defined in the following claims. In the claims, means- or step-plus-function clauses are intended to cover the structures described or suggested herein as performing the recited function and not only structural equivalents but also equivalent structures. Thus, for example, although a nail, a screw, and a bolt may not be structural equivalents in that a nail relies entirely on friction between a wooden part and a cylindrical surface, a screw's helical surface positively engages the wooden part, and a bolt's head and nut compress opposite sides of at least one wooden part, in the environment of fastening wooden parts, a nail, a screw, and a bolt may be readily understood by those skilled in the art as equivalent structures.
Having described preferred embodiments of the invention with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention as defined in the appended claims.
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A portable hydraulic stake puller includes a hydraulic cylinder that extends to raise a jaw assembly. The jaw assembly pivots, while being raised, to grab and trap the stake. A grab hook may alternatively extract similar items not readily removable with the jaw assembly. The jaw or chain tension is controllably released when the control lever is released at any height of the stroke. Squeezing the control lever can again attain grip easily. The gripping action of the jaw is attained by at least friction against the jaw. When the control lever is released, the entire lift assembly returns to the neutral position under a spring tension. The hydraulic stake puller is mounted on wheels and controlled via handles allowing easy maneuvering.
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FIELD
[0001] This application claims all rights and priority on prior pending patent applications U.S. Ser. No. 12/774,763 filed May 6, 2010, CN201010180707.7 filed May 6, 2010, and PCT/CH2011/000107 filed May 5, 2011. The present invention relates to the field of fiber processing. More particularly, it relates to a method and an apparatus for measuring the weight of impurities in a mixed volume of fibers and impurities. One embodiment is the measurement of the impurity content in raw cotton.
BACKGROUND
[0002] Currently in the textile industry, it is usually necessary to measure the fiber impurity content in raw cotton. The impurity content means the ratio of undesired impurities such as sand, branches and leaves, boll hull, and soft seed skin in the fiber. For example, the impurity content of saw ginned cotton according to the Chinese National Standard is 2.5%. A raw cotton impurity analyzer is generally used in actual work to measure the raw-cotton impurity content. As the term is used herein, “impurities” refers to any non-primary-fiber material, such as husks, twigs, leaves, dirt, rocks, and any other non-primary-fiber material that might become mixed into the fiber volume. In other publications, the term “trash” is used as a synonym for “impurities.” In the case of cotton fibers for example, “impurities” refers to anything that isn't cotton fiber.
[0003] A test analysis instrument with a single taker-in cylinder mechanism, e.g. YG041, YG042, and Y101 as described in Chinese National Standard (GB/T0499) “Testing methods for the trash contents of raw cotton,” is adopted in all the traditional test methods for raw cotton impurity content. The typical structure of these traditional raw cotton impurity analyzers is the following: first there is a cotton feeding roller, behind which is a taker-in cylinder, along the circumference of which are installed two or more separation knives; then there is an air current channel for stripping and taking away the fibers on the surface of the taker-in cylinder; and below the separation knife is an impurity disk that is used for collecting impurities and can be taken out manually.
[0004] The mechanical impurity-separation principle applied in the known instruments is the following: the raw cotton is rolled up by the cotton feeding roller and brought into contact with the taker-in cylinder. The taker-in cylinder rotates at a high speed and combs the raw cotton. The fibers and the impurities, being loosened after being combed by the sawtooth structure on the surface of the taker-in cylinder, adhere to the surface of the taker-in cylinder under the action of an air current, and rotate at a high speed along with the taker-in cylinder. Due to the different shapes, masses and densities of the fibers and the impurities, under the combined action of the centrifugal force and the air current, the fibers adhere to the surface of the taker-in cylinder, while the impurities are floated in the air current layer farther away from the surface of the taker-in cylinder. When passing across the separation knife, the impurities are blocked and fall down to the impurity disk under the action of gravity, while the fibers continue to rotate with the taker-in cylinder. When the fibers continuing to rotate with the taker-in cylinder are brought into the air current channel tangent to the rotating direction of the taker-in cylinder, due to the pressure change resulting from the special shape of the air current channel, the fibers are detached from the surface of the taker-in cylinder, and taken away by the air current.
[0005] During the above-mentioned impurity separation process, under the action of machinery and the air current, a small amount of fibers may inevitably be detached from the surface of the taker-in cylinder and fall onto the impurity disk. In the traditional impurity analytical apparatus, the weight content of impurities in the raw cotton can be obtained through manual picking and weighing of the fibers admixed to the impurities. This manual picking method will not only waste a great deal of manpower and time, but also its results show personal differences resulting from the personal picking, causing a deviation in the measured value.
[0006] The publication EP-0'533'079 A2 gives an example of an aeromechanical separation of impurities from fibers, as applied in the fiber-testing system USTER® AFIS PRO 2 from Uster Technologies AG, Uster, Switzerland. The weight of the mixed volume of fibers and impurities is measured by weighing on scales. Then the mixed volume is formed into a sliver, and the sliver is delivered to a first pinned separator wheel. A second pinned separator wheel is located below the first separator wheel. The separator wheels have each a radius of about 32 mm and rotate at very high speeds of 7000-8000 rpm (i.e., 117-133 s −1 ). Due to the large centrifugal forces generated at such high rotational speeds, the impurities are centrifuged from the surfaces of the separator wheels into a counterflow of air. The counterflow air returns fibers back to the separator wheels, but is overcome by the impurities. The thus separated impurities are optically sensed by an optical sensor. A computer receives the weight data from the scales and the output signal from the optical sensor. It calculates the weight of the impurities from the accumulated projected area of the impurities. The fibers may be processed in the same way as the impurities. This method also suffers from the drawback that the mechanical separation may be incomplete.
[0007] In summary, the conventional analysis instruments and methods have shortcomings such as low efficiency and great labor load; besides, two analysis cycles on the test sample are generally required in the test analysis process, with the lower analysis efficiency; moreover, the separated impurities usually contain effective cotton fibers, which results in a deviation in the test result and requires manual picking, thus still resulting in a personal difference in the test result.
SUMMARY
[0008] A purpose of the embodiments according to the present invention is to provide an apparatus and a method for measuring the weight of impurities in a mixed volume of fibers and impurities, which not only increase efficiency and accuracy of the measurement to a great extent, but also reduce the labor load.
[0009] The above problem is solved by the method and the apparatus as defined in the independent claims. Additional embodiments are defined in the dependent claims.
[0010] Any mechanical separation of the impurities from the fibers in the mixed volume is potentially imperfect, since some undesired fibers will still remain admixed to the impurities after separation. Therefore, the embodiments according to the invention propose to mechanically separate the impurities from the fibers, to weigh the separated impurities and the undesired fibers, and to subsequently correct the measured weigh by means of image processing. In this manner, the weight can be corrected by electronic means. This yields a more accurate weight of the impurities.
[0011] In the inventive method for measuring the weight of impurities in a mixed volume of fibers and impurities, the impurities are mechanically separated from the fibers, whereupon some undesired fibers still remain admixed to the impurities due to imperfections of the mechanical separation. A total weight of the separated impurities and the undesired fibers is gravimetrically measured. An image of the separated impurities and the undesired fibers is created. A weight of the undesired fibers is estimated from the image. The estimated weight of the undesired fibers is subtracted from the total weight to yield a corrected weight of the impurities.
[0012] In one embodiment, an air current is provided for the mechanical separation. The mixed volume is fed onto a surface of a rotating primary taker-in cylinder located in the air current. The impurities are mechanically striped off from the fibers on the primary taker-in cylinder. Part of the mixed volume is transferred from the primary taker-in cylinder to a secondary taker-in cylinder located in the air current. The impurities are separated from the fibers on the secondary taker-in cylinder. The impurities separated on the primary taker-in cylinder and the secondary taker-in cylinder are collected.
[0013] The separation of the impurities from the fibers on the primary taker-in cylinder and the secondary taker-in cylinder may make use of the action of centrifugal force, gravity, the air current and mechanical stripping.
[0014] In one embodiment, the primary taker-in cylinder has a diameter of 20-30 cm, and in another of 25 cm, and the secondary taker-in cylinder has a diameter of 10-20 cm, and in another of 16 cm. The primary taker-in cylinder rotates at a rotational speed of 1300-1700 rpm (21.7-28.3 s −1 ), and in another embodiment at 1500 rpm (25.0 s −1 ). The secondary taker-in cylinder rotates at a rotational speed of 900-1200 rpm (15.0-20.0 s −1 ), and in another embodiment at 1050 rpm (17.5 s −1 ). The primary taker-in cylinder has a surface linear velocity of 15-25 m/s, and in another embodiment of 19.7 m/s, and the secondary taker-in cylinder has a surface linear velocity of 5-12 m/s, and in another embodiment of 8.7 m/s. The centrifugal acceleration on the surface of the primary taker-in cylinder is 1860-4740 m/s 2 , and in another embodiment of 3090 m/s 2 , and the centrifugal acceleration on the surface of the secondary taker-in cylinder is 444-1580 m/s 2 , and in another embodiment of 967 m/s 2 . These centrifugal accelerations are clearly lower than those on the surfaces of the separator wheels as described in EP-0'533'079 A2, where mechanical stripping devices are not used.
[0015] In some embodiments the surface of at least one of the primary taker-in cylinder and the secondary taker-in cylinder bears a serrated structure or sawtooth structure. The primary taker-in cylinder and the secondary taker-in cylinder may have the same rotational direction.
[0016] In one embodiment, the air current below the taker-in cylinders has essentially a horizontal direction. Such a horizontal air current acts like a sheet of air that carries away fibers detached from the taker-in cylinders. The impurities, which are heavier than the fibers, fall through this sheet of air under the action of gravity.
[0017] The inventive apparatus for measuring the weight of impurities in a mixed volume of fibers and impurities comprises a separation device for mechanically separating the impurities from the fibers, a gravimetric scale for measuring a total weight of the separated impurities and undesired fibers remaining admixed to the impurities, and a sensor for creating an image of the separated impurities and the undesired fibers. The apparatus further comprises a processor for detecting undesired fibers within the image, estimating a weight of the undesired fibers from the image, and subtracting the estimated weight of the undesired fibers from the total weight to yield a corrected weight of the impurities.
[0018] In one embodiment, the separation device comprises an air current channel, a fiber feeding device located at a front end of the air current channel, a primary taker-in cylinder located in the air current channel behind the fiber feeding device, and at least one stationary stripping device located near the surface of the primary taker-in cylinder. A secondary taker-in cylinder is located in the air current channel behind the primary taker-in cylinder, surfaces of the primary taker-in cylinder and the secondary taker-in cylinder being adjacent to each other. An impurity collecting apparatus is located below the primary taker-in cylinder and the secondary taker-in cylinder. In one embodiment the impurity collecting apparatus is connected to the gravimetric scale.
[0019] The primary taker-in cylinder and the secondary taker-in cylinder in one embodiment are mutually arranged such that part of the mixed volume is transferrable from the primary taker-in cylinder to the secondary taker-in cylinder. In one embodiment, the minimum distance between the surfaces of the taker-in cylinders is between 0.1 and 1 mm, and in another embodiment is 0.25 mm. The primary taker-in cylinder has a diameter of 20-30 cm, and in another embodiment is 25 cm, and the secondary taker-in cylinder has a diameter of 10-20 cm, and in another embodiment is 16 cm.
[0020] In one embodiment, the separation device comprises a drive mechanism for the primary taker-in cylinder, which drive mechanism is adapted for driving the primary taker-in cylinder at a rotational speed of 1300-1700 rpm (21.7-28.3 s −1 ), and in another embodiment of 1500 rpm (25.0 s −1 ). Likewise, the separation device comprises a drive mechanism for the secondary taker-in cylinder, which drive mechanism is adapted for driving the secondary taker-in cylinder at a rotational speed of 900-1200 rpm (15.0-20.0 s −1 ), and in another embodiment of 1050 rpm (17.5 s −1 ). At least one of the primary taker-in cylinder and the secondary taker-in cylinder may have a width in axial direction of 30-70 cm, and in another embodiment of 50 cm. The surface of at least one of the primary taker-in cylinder and the secondary taker-in cylinder may bear a serrated structure or sawtooth structure. Such serrated surfaces are more aggressive than the pinned surfaces known from the prior art, and thus more effectively separate the impurities from the fibers. A potential damaging of the fibers is irrelevant in the present application. The height of the serrated structure may be 1-4 mm, and in another embodiment is 2.5 mm.
[0021] The apparatus according to the embodiments of the invention is thus able to process 30 grams of sample per minute, whereas the apparatus according to EP-0'533'079 A2 processes only 0.25 grams per minute. The high processing capacity makes the apparatus according to the invention suitable for high-volume fiber processing.
[0022] At least one additional stationary stripping device may be located near the surface of the secondary taker-in cylinder. The distance between the at least one stripping device and the surface of the respective taker-in cylinder is between 0.1 mm and 1 mm, and in another embodiment is between 0.2 and 0.6 mm.
[0023] The fiber feeding device preferably includes a fiber feeding roller and a fiber feeding plate.
[0024] Thanks to the embodiments according to the present invention, the mixed volume does not need to be painstakingly separated in some time-consuming or labor-consuming process. Nor does the weight need to be compromised by the weight of undesired fibers. Thus, a corrected weight that accurately represents the impurities can be quickly, easily, and automatically generated. After the preferred double impurity removal with the primary taker-in cylinder and the secondary taker-in cylinder, the impurities are removed from the cotton sample more completely compared to the prior-art single taker-in cylinder structure, making the subsequent impurity measurement value more accurate. Therefore, efficiency and accuracy of the measurement is increased significantly.
DRAWINGS
[0025] Embodiments of the present invention are further described below in detail with reference to the drawings.
[0026] FIG. 1 shows a functional block diagram of the apparatus according to an embodiment the invention.
[0027] FIG. 2 shows a functional block diagram of the impurity separation section of the apparatus according to an embodiment the invention.
[0028] FIG. 3 shows a schematic front view of part of a taker-in cylinder included in the apparatus according to an embodiment the invention.
[0029] FIG. 4 shows a functional block diagram of the weight-determining section of the apparatus according to an embodiment the invention.
[0030] FIG. 5 shows a flow chart of an embodiment of the method according to the invention.
DESCRIPTION
[0031] As can be seen in FIG. 1 , the apparatus according to the invention comprises a fiber feeding device comprising a fiber feeding roller 1 and a fiber feeding plate 2 , the fiber feeding roller 1 feeding the raw cotton sample (not shown) that needs an impurity test. The raw cotton sample, gripped by the fiber feeding roller 1 and the fiber feeding plate 2 , is combed by a primary taker-in cylinder 5 and a secondary taker-in cylinder 6 . The mechanical separation of the impurities from the fibers is described in more detail below with reference to FIGS. 2 and 3 .
[0032] An impurity disk 8 is positioned below the taker-in cylinders 5 , 6 . The impurities that are combed out fall downwards to the impurity disk 8 . The impurity disk 8 is big enough such that all the impurities separated from the taker-in cylinders 5 , 6 are collected on the impurity disk 8 . An electronic scale 9 is positioned below the impurity disk 8 and in some embodiments is connected to it. The impurities, falling to the impurity disk 8 when passing across the taker-in cylinders 5 , 6 , are weighed automatically by the electronic scale 9 after sample completion.
[0033] In most cases the separation of the impurities from the fibers is imperfect, so that some undesired fibers are still admixed to the impurities on the impurity disk 8 . Therefore, the weight measured by the electronic scale 9 is higher than the actual weight of the impurities. The invention proposes to correct the weight, as described in the following. A digital camera 12 takes images of the impurities and undesired fibers on the impurity disk 8 . The digital camera 12 and the electronic scale 9 are both connected to a processor 13 . The processor 13 analyzes the image provided by the digital camera 12 and estimates the weight of the undesired fibers admixed to the impurities by means of image processing. Then it corrects the measured weight by subtracting from it the estimated weight of the undesired fibers. The weight correction is described in more detail below with reference to FIGS. 4 and 5 .
[0034] FIG. 2 shows in more detail the mechanical impurity separation section of the apparatus according to the present invention. It includes an air current channel which comprises an air current guide 7 . The fiber feeding device 1 , 2 and the taker-in cylinders 5 , 6 are arranged in the air current. The directions of the air current at various locations are indicated by arrows. The air current below the taker-in cylinders 5 , 6 has an essentially horizontal direction. The black dots shown in FIG. 2 indicate the impurities 11 that are combed out, some of the impurities 11 falling downwards to the impurity disk 8 under the combined action of gravity and centrifugal force.
[0035] Primary separation knives 3 . 1 , 3 . 2 are positioned in a stationary manner along and near the surface of the primary taker-in cylinder 5 . The above-mentioned impurities adhering to the taker-in cylinder 5 , when passing across the primary separation knives 3 . 1 , 3 . 2 , are blocked by the separation knives 3 . 1 , 3 . 2 and fall down to the impurity disk 8 . Thus, the separation knives 3 . 1 , 3 . 2 act as stripping devices that strip off or comb out the impurities. There are one or more such separation knives 3 . 1 , 3 . 2 , the amount being determined as required. The linear surface velocity v (see FIG. 3 ) of the primary taker-in cylinder 5 according to the invention is significantly higher, e.g., nearly twice as high, than that of the taker-in cylinder in a traditional analytical apparatus. It is within the range of 15-25 m/s in one embodiment, and in another embodiment of 17.7-21.7 m/s, and in another embodiment is 19.7 m/s.
[0036] According to the embodiments of the present invention, behind the primary taker-in cylinder 5 is positioned the secondary taker-in cylinder 6 , whose surface is near but not in direct contact with the surface of the primary taker-in cylinder 5 . The secondary taker-in cylinder 6 rotates more slowly than the primary taker-in cylinder 5 ; its linear surface velocity v in one embodiment is within 5-15 m/s, and in another embodiment within 7.5-9.9 m/s, and in another embodiment is 8.7 m/s. The secondary taker-in cylinder 6 has the same rotational direction as the primary taker-in cylinder 5 . In the region where the surfaces of the taker-in cylinders 5 , 6 have minimum distance, the surface speed vectors of the taker-in cylinders 5 , 6 are opposed to each other and the relative linear surface velocity equals the sum of the two velocities. The fibers are transferred from the primary taker-in cylinder 5 to the secondary taker-in cylinder 6 .
[0037] The cotton fibers, after being combed, are attached to the surface of the primary taker-in cylinder 5 and move with it and, when passing the region where the surfaces of the taker-in cylinders 5 , 6 have minimum distance, are combed again by the secondary taker-in cylinder 6 . Thus, impurities not combed out by the separation knives 3 . 1 , 3 . 2 are combed out by the secondary taker-in cylinder 6 . In addition, a secondary separation knife 4 may be assigned to the secondary taker-in cylinder 6 ; the secondary separation knife 4 and the secondary taker-in cylinder 6 cooperate as described for the primary separation knives 3 . 1 , 3 . 2 and the primary taker-in cylinder 5 in order to strip off the remaining impurities. As mentioned above, the impurities 11 fall to the impurity disk 8 under the action of gravity and centrifugal force. Thus, the invention, after double impurity removal with the primary taker-in cylinder 5 and the secondary taker-in cylinder 6 , removes the impurities from the cotton sample more completely compared to the prior-art single taker-in cylinder structure, making the subsequent impurity measurement value closer to the actual value.
[0038] The cotton fibers, on the other hand, continue to rotate with the taker-in cylinders 5 , 6 . When the air current is tangent to the surface-velocity vector of the respective taker-in cylinder 5 , 6 , they experience a pressure drop. The fibers are then detached from the surface of the respective taker-in cylinder 5 , 6 , and taken away by the air current.
[0039] The secondary taker-in cylinder 6 can be designed to have the same structure as the primary taker-in cylinder 5 . For example, two or more separation knives, the amount being determined as required, can be positioned along the surface of the secondary taker-in cylinder 6 .
[0040] The primary taker-in cylinder 5 has a diameter 2 r (see FIG. 3 ) in one embodiment of 20-30 cm, and in another embodiment of 25 cm, and the secondary taker-in cylinder 6 has a diameter 2 r in one embodiment of 10-20 cm, and in another embodiment of 16 cm. The widths in axial direction of the taker-in cylinders 5 , 6 in one embodiment are 30-70 cm, and in another embodiment are 50 cm. The minimum distance between the surfaces of the taker-in cylinders 5 , 6 in one embodiment is between 0.1 and 1 mm, and in another embodiment is 0.25 mm. The distance between each of the separation knives 3 . 1 , 3 . 2 , 4 and the surface of the primary taker-in cylinder in one embodiment is between 0.1 and 1 mm, and in another embodiment is between 0.2 mm and 0.6 mm.
[0041] FIG. 3 shows a schematic front view, not to scale, of part of the taker-in cylinder 5 or 6 . The radius r of the taker-in cylinder 5 , 6 in one embodiment is in the range between 5 and 15 cm. The surface of the taker-in cylinder 5 , 6 bears a serrated structure 10 built up, e.g., of a sequence of saw teeth equally distributed along the circumference of the taker-in cylinder 5 , 6 . In one embodiment the height h of the serrated structure is in the range between 1 and 4 mm, i.e., the ratio of the height h and the radius r is in the range between 0.7% and 8%. The serrated structure 10 extends over essentially the whole width of the taker-in cylinder 5 , 6 . This may be realized by a serrated band that wraps the lateral area of the cylinder 5 , 6 in the form of a helical curve. The angular speed w of the taker-in cylinder 5 , 6 in one embodiment is in the range between 94.3 rad/s and 178 rad/s. The surface velocity v can be calculated according to the formula:
[0000] v=ωr,
[0042] and the centrifugal acceleration a is given by the formula:
[0000] a=ω 2 r.
[0043] The embodiments of present invention can be applied to the impurity measurement in raw cotton and other fiber products. The embodiments discussed above have a primary taker-in cylinder 5 and a secondary taker-in cylinder 6 . Depending on the actual application, based on the conception of the present invention, a third taker-in cylinder, a fourth taker-in cylinder and so on can be provided, with their surfaces consecutively near to each other and their structure being similar to that according to the embodiment discussed above. The total number N of taker-in cylinders is a positive integer bigger than or equal to 2.
[0044] The fibers, after being combed by the primary taker-in cylinder 5 , can be combed again by the secondary taker-in cylinder 6 according to the invention, which can comb out more impurities that are not combed out during the first impurity removal process. For example, the apparatus according to the above embodiment of the invention can complete the impurity weight content analysis of a 30-gram raw cotton sample within one minute. Its efficiency is increased by a factor of 3.5 compared with the traditional raw cotton impurity content analysis instruments. Meanwhile, with the introduction of a camera system, the analysis accuracy of raw cotton impurity content is increased to a great extent, and the labor load reduced at the same time.
[0045] In FIG. 4 , there is depicted a functional block diagram of a weight-determining section of the apparatus according to the invention. The impurity disk 8 receives the volume in which impurities 11 are to be weighed. In the example as depicted, the volume is comprised of components 11 , 14 and 15 . For example, the volume might include impurities 11 , an unknown object 14 , and fibers 15 . The electronic scale 9 measures the total weight of the volume, and provides the total weight to the processor 13 for further analysis. The camera 12 records an image of the volume on the impurity disk 8 within a field of view 16 , and provides the image to the processor 13 for further analysis. The processor 13 implements the algorithm as described below, and determines the corrected weight, as desired.
[0046] With reference now to FIG. 5 , there is depicted a flow-chart of a method according to the invention. As given in block 101 , the impurities 11 are mechanically separated from the fibers 15 , albeit incompletely, so that some undesired fibers 15 are admixed to the impurities 11 . The separated impurities 11 and the remaining undesired fibers 15 are weighed, as given in block 102 . This weight can be accomplished in a variety of different ways. For example, the separated impurities 11 and the remaining undesired fibers 15 can be directly weighed with a gravimetric device like a scale 9 . Whatever method is used, this initial weight of the mixed volume is designated herein as the total weight.
[0047] An image is then created of the volume on the impurity disk 8 , as given in block 103 . In some embodiments, the volume is scattered across a surface, such that all components of the mixed volume can be readily seen from one direction, such as from above the volume. In this manner, the individual components of the mixed volume are not hidden, one by another, from the view-point of the camera 12 . In some embodiments a single optical visible-light image from a single camera 12 at a single location is used to create the image of the volume. In other embodiments, multiple images from multiple sensors at multiple orientations are created, and in some embodiments wavelengths other than visible wavelengths are used to create the image or images. In still other embodiments, three-dimensional or quasi-three-dimensional imaging techniques such as tomography are applied. Other combinations of properties such as these are also contemplated.
[0048] Once the image has been obtained, as given in block 103 , an algorithm is performed using the image as an input. The algorithm discriminates the various components of the image, as given in block 104 . By “discriminates” it is meant that the various components 11 , 14 , 15 of the volume as depicted in the image are identified as to classification. For instance, those portions of the image that represent fibers 15 are identified as one classification, and those portions of the image that represent impurities 11 are identified as another classification.
[0049] The algorithm can be adapted so as to identify more than two classes of components 11 , 14 , 15 within the volume, as desired. Various threshold levels can be set as desired so as to make the determination as to how a given portion of the image should be classified. Because in some embodiments the volume does not completely cover the surface upon which is it disposed, the algorithm can be set, in those embodiments, to exclude from classification those portions of the surface that are visible in the image, as desired.
[0050] Once the image has been classified, the weight of at least those classes of material that do not relate to impurities 11 is estimated, as given in block 105 , such as by the algorithm. In some embodiments, the weights of all of the classes of material within the volume are estimated, or the weights of some variable number of the classes are estimated. This can be accomplished by, for example, determining from the image the total volume of fibers 15 within the volume, and then multiplying that total volume by a presumed or measured fiber density value. A variety of different algorithms for determining the weight of the fibers 15 could be used in different embodiments. These determined weights are designated as the component weights.
[0051] After the weight of at least one component of the volume has been estimated, the corrected weight of the impurities is determined, as given in bock 106 , such as by subtracting one or more of the component weights from the total weight. For example, the component weight of the fibers 15 can be subtracted from the total weight, yielding a corrected weight of impurities 11 .
[0052] It is appreciated that some of the steps of the embodiment of the method as described above do not need to be performed in the order as described above or depicted in FIG. 5 . For example, measuring the total weight of the mixed volume, as represented in block 102 , does not need to be accomplished prior to imaging the mixed volume and estimating the component weight or weights, as given in blocks 103 - 105 . However, the steps of measuring the total weight 102 and estimating at least one component weight 105 do need to be accomplished prior to determining the corrected weight 106 . In some embodiments, these steps of measuring the total weight 102 and estimating at least one component weight 105 are accomplished substantially simultaneously.
[0053] The present invention is not limited to the embodiments discussed above. The descriptions of the embodiments above are only for describing and explaining the technical solution involved in the invention. An obvious transformation and substitution based on the present invention should also be thought to be within the scope of protection of the invention. The embodiments above are used to enable those skilled in the art to achieve the purpose of the present invention by using various embodiments and various substitute methods.
REFERENCES
[0000]
1 Fiber feeding roller
2 Fiber feeding plate
3 . 1 , 3 . 2 Primary separation knives
4 Secondary separation knife
5 Primary taker-in cylinder
6 Secondary taker-in cylinder
7 Air current guide
8 Impurity disk
9 Electronic scale
10 Serrated structure
11 Impurities
12 Sensor
13 Processor
14 Unknown object
15 Fiber
16 Field of view
101 Mechanical separation
102 Total weight measurement
103 Image creation
104 Image discrimination
105 Fiber weight estimation
106 Weight correction
h Height of the serrated structure
r Radius of the taker-in cylinder
v Surface linear velocity of the taker-in cylinder
ω Rotational speed of the taker-in cylinder
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A method for measuring the weight of impurities in a mixed volume of fibers and impurities by mechanically separating the impurities are from the fibers, whereupon some undesired fibers still remain admixed to the impurities due to imperfections of the mechanical separation. A total weight of the separated impurities and the undesired fibers is gravimetrically measured. An image of the separated impurities and the undesired fibers is created. A weight of the undesired fibers is estimated from the image. The estimated weight of the undesired fibers is subtracted from the total weight to yield a corrected weight of the impurities. The mechanical separation and the subsequent electronic correction yield a more accurate weight of the impurities.
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RELATED APPLICATION
The present disclosure relates to subject matter contained in priority Korean Application No. 10-2006-0098151, filed on Oct. 9, 2006, which is herein expressly incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to air conditioning, and more particularly, to a dehumidification apparatus for removing moisture from the air and lowering a temperature of the air, and an air conditioning apparatus and system having the same.
2. Description of the Background Art
Air conditioning is to keep temperature, humidity, air stream, bacteria, dust and harmful gas in the best conditions for persons or objects indoors. The representative air conditioning functions include cooling and heating relating to temperature control, and dehumidification and humidification relating to humidity control.
In addition to electricity generation, the cogeneration supplies heat to district heating or industrial processing by using the waste heat from the electricity generation process.
FIG. 1 is a concept view illustrating a heating process of houses by cogeneration.
Waste heat discarded from the process of electricity generation of a cogeneration plant 10 is stored in a thermal storage tank 11 , and transferred to a liquid (water) flowing in a heat transfer line 14 through a heat exchanger 12 by a circulation pump 13 . The resulting hot water is transferred to a cooling/heating system 20 of the houses.
A heat exchanger 21 of the cooling/heating system 20 exchanges heat between the hot water and the water circulating in a hot water circuit 22 . Then, the hot water is supplied to the houses in response to demand in the houses.
Since the production ratio of power to heat is fixed to about 3:4, it is advantageous if the ratio of demands for power and heat is close to the production ratio. However, the demands for power and heat from commercial or residential sectors show very different patterns from each other in annual variation.
The demand for power has a maximum value in summer with a relatively small annual fluctuation, while the demand for heat has a large fluctuation with a maximum value in winter. According to a statistical review, the ratio of the minimum to the maximum in the annual heat demand is only 8.7% in middle and high latitude regions.
FIG. 2 is an instance showing monthly heat/electricity supply from a district heating corporation.
As shown in FIG. 2 , according to the demand for heat, the heat supply N 2 from the district heating corporation has a minimum value from June to September, namely, a hot season. A particular point in the graph is that the electricity supply N 1 becomes almost zero in the summer regardless of the increasing demand in the electricity in the summer. This is because the cogeneration stops in the summer and the small heat demand is sufficed by a dedicated boiler for heat supply. The reason for this is that the operation of the cogeneration is economically efficient and energy efficient as well only when the demand ratio between electricity and heat matches well with the production ratio, as mentioned previously. When the demand ratio deviates much from the production ratio, the operation of cogeneration becomes economically inefficient and the cogeneration process needs to be stopped.
As described above, the efficient operation of the cogeneration plant cannot be ensured in summer without increasing the demand for the waste heat generated as a byproduct from the electricity generation.
As shown in FIG. 1 , in order to increase the demand for heat in summer, the district cooling has been devised applying an absorption type chiller 23 using the district heat as the heat source. However, the absorption type chiller 23 has a drawback in that the cooling performance of the chiller decreases considerably with a low temperature heat source such as the waste heat from the cogeneration plant 10 . In addition, the cold water circuit 24 connected to the absorption type chiller 23 must be installed separately from the hot water circuit 22 .
SUMMARY OF THE INVENTION
Therefore, an object of the present invention is to provide a desiccant cooling system using hot water as the heat source for the regeneration of the desiccant.
Another object of the present invention is to perform air conditioning including cooling and dehumidification.
To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided a dehumidification apparatus, including: a desiccant rotor having a desiccant for adsorbing moisture; and a regeneration unit disposed at one side of the desiccant rotor, for desorbing the moisture adsorbed to the desiccant, wherein the regeneration unit comprises at least one of a hot water tube containing hot water exchanging heat with the air flowing toward the desiccant rotor.
According to the second embodiment of the present invention, there is provided an air conditioning apparatus, including: a casing enclosing first and second channels separated by a partition wall; a desiccant rotor rotatably installed across the partition wall to be placed crossing the channels, for adsorbing moisture from an air flowing into the first channel; and a regeneration unit configured to desorb the moisture adsorbed to the desiccant rotor, by heating an air flowing into the second channel toward the desiccant rotor.
According to the third embodiment of the present invention, there is provided an air conditioning apparatus, including, a first hollow casing having its inlet and outlet opened to be in communication with the outdoor air; a second hollow casing disposed in the first casing, for partitioning off the first casing into first and second channels in communication with each other; a partition wall formed in the second casing, for partitioning off the second casing into third and fourth channels in communication with each other; a desiccant rotor rotatably installed in the second casing to be placed crossing the adjacent first and fourth channels, for adsorbing moisture from an air flowing into the first channel; a regeneration unit disposed in the fourth channel, for desorbing the moisture adsorbed to the desiccant rotor, by heating an air flowing into the fourth channel; and a heat exchanger placed crossing the adjacent second and third channels, for exchanging heat between an air flowing in the second channel and the air flowing into the third channel through the desiccant rotor.
According to the fourth embodiment of the present invention, there is provided an air conditioning system, including, a dehumidification system having a desiccant for adsorbing moisture; and a hot water supply system in communication with the dehumidification system, for supplying hot water, and also supplying heat for regenerating the desiccant of the dehumidification system.
The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention.
In the drawings:
FIG. 1 is a concept view illustrating a heating process of houses by cogeneration;
FIG. 2 is a graph showing monthly heat/electricity supply of a district heating corporation;
FIG. 3 is a concept view illustrating a dehumidification apparatus in accordance with one preferred embodiment of the present invention;
FIG. 4 is a concept view illustrating an air conditioning apparatus in accordance with another preferred embodiment of the present invention;
FIG. 5 is a concept view illustrating an air conditioning apparatus in accordance with yet another preferred embodiment of the present invention; and
FIG. 6 is a concept view illustrating a cooling process of houses by using the district heat supply.
DETAILED DESCRIPTION OF THE INVENTION
Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.
FIG. 3 is a concept view illustrating a dehumidification apparatus in accordance with one preferred embodiment of the present invention.
Referring to FIG. 3 , the dehumidification apparatus 100 includes a desiccant rotor 110 and a regeneration unit 120 .
The desiccant rotor 110 is normally formed in a cylindrical shape filled with a honeycomb structure, so that the air can pass through channels defined by the honeycomb structure. A desiccant (not shown) such as silica gel, zeolite or LiCl is coated on the walls defining the air paths through the desiccant rotor 110 . The desiccant adsorbs moisture from the air passing through the desiccant rotor 110 . The desiccant rotor 110 is mounted on a structure (not shown) to be rotated around a rotation shaft 111 at its center.
The regeneration unit 120 is disposed at one side of the desiccant rotor 110 , for heating the air flowing toward the desiccant rotor 110 . Hot water is supplied to the regeneration unit 120 to provide thermal energy to heat the air. Accordingly, the regeneration unit 120 becomes at least one of a hot water air heater. The hot water supplied to the regeneration unit can be from a district energy facility such as a cogeneration plant 500 (refer to FIG. 6 ), or a water heater for heating (not shown) such as a boiler.
Moreover, in order to prevent mixing of the air flows F 1 and F 2 flowing into first and second regions A 1 and A 2 of the desiccant rotor 110 , respectively, a partition wall (not shown) can be installed on a imaginary line 112 dividing the first and second regions A 1 and A 2 .
The operation of the dehumidification apparatus 100 in accordance with the present invention will now be described.
The air flow F 1 flowing into the first region A 1 of the desiccant rotor 110 passes through the desiccant rotor 110 through a channel formed by the honeycomb structure of the desiccant rotor 110 . In this process, the desiccant coated on the desiccant rotor 110 adsorbs moisture from the air flow F 1 . Therefore, the air flow F 1 ′ is dehumidified and dried through the desiccant rotor 110 . On the other hand, the first region A 1 of the desiccant rotor 110 has high moisture uptake due to the moisture adsorption.
The air flow F 2 passing through the regeneration unit 120 is heated to the regeneration temperature by the hot water flowing in the regeneration unit 120 . This air flow F 2 at the regeneration temperature flows into the second region A 2 of the desiccant rotor 110 .
Since the desiccant rotor 110 rotates around the rotation shaft 111 , the part of the desiccant rotor 110 with high moisture uptake previously occupied the first region A 1 turns to the second region A 2 . Then the moisture is desorbed by the air flow F 2 having the raised temperature. As a result, the air flow F 2 ′ which has passed through the second region A 2 has high humidity.
As the moisture is desorbed by the air flow F 2 , the second region A 2 is dried again, which is called regeneration of the desiccant rotor 110 . The regenerated part of the desiccant rotor 110 at the second region A 2 turns to the first region A 1 as the desiccant rotor 110 rotates. Accordingly, at the first region A 1 the moisture is removed from the air flow F 1 continuously.
In the above dehumidifying process, the air flow F 2 supplied to the desiccant rotor 110 directly contacts the desiccant rotor 110 and transfers heat, thereby improving transfer efficiency. Even if the temperature of the regeneration heat source (hot water) is low, the desiccant rotor 110 is efficiently regenerated to attain a sufficient dehumidification effect.
FIG. 4 is a concept view illustrating an air conditioning apparatus in accordance with another preferred embodiment of the present invention.
As illustrated in FIG. 4 , the air conditioning apparatus 200 includes a casing 210 , a desiccant rotor 220 and a regeneration unit 230 .
The casing 210 encloses two channels, i.e., the first and the second channels 211 and 212 . The first and second channels 211 and 212 are divided by a partition wall 213 disposed inside the casing 210 . Both ends of the first and second channels 211 and 212 are opened, so that the air can flow through the first and second channels 211 and 212 , respectively.
The desiccant rotor 220 and the regeneration unit 230 correspond to the desiccant rotor 110 and the regeneration unit 120 , respectively, mentioned above. Detailed explanations thereof are omitted.
The desiccant rotor 220 is installed across the partition wall 213 to be placed crossing the first and second channels 211 and 212 . The regeneration unit 230 is disposed inside the second channel 230 . As mentioned above, the regeneration unit 230 is a hot water air heater supplied with hot water from the district energy facility or the water heater for space heating.
To facilitate the air flows passing through the first and second channels 211 and 212 , first and second fans 241 and 242 can be additionally disposed in the first and second channels 211 and 212 , respectively.
When the air flow which has passed through the first channel 211 is supplied to an indoor space intended to be air-conditioned, the air flow passing through the second channel 212 must be taken from an outdoor space and discharged back to the outdoor space. For this, extension ductwork 260 for connecting the second channel 212 to the outdoor space is provided with at both ends of the second channel 212 .
To supply the low temperature and low humidity air into the indoor space, a cooling unit 250 is added to the dehumidification apparatus.
For example, a sensible heat rotor 251 can be used as the cooling unit 250 . The sensible heat rotor 251 is made of heat absorbing material having high thermal capacity, so that the air flows flowing in the first and second channels 211 and 212 can exchange heat via the sensible heat rotor 251 . The air in the first channel 211 flowing out of the desiccant rotor 220 , which is increased in temperature due to the heat release from the moisture sorption process through the desiccant rotor 220 , is cooled transferring heat to the sensible heat rotor 251 . Then, the heated part of the heat rotor 251 rotates into the second channel 212 to release heat to the air flowing from outdoors. For this, identically to the desiccant rotor 220 , the sensible heat rotor 251 is installed across the partition wall 213 , and rotates over the first and second channels 211 and 212 .
For further cooling, a cooling coil 252 can be installed in the first channel 211 at the outlet of the sensible heat rotor 251 . The cooling coil 252 additionally cools the air which has passed through the sensible heat rotor 251 by refrigerants or chilled water.
FIG. 5 is a concept view illustrating an air conditioning apparatus in accordance with yet another preferred embodiment of the present invention.
As shown in FIG. 5 , the air conditioning apparatus 300 includes a first casing 310 , a second casing 320 , a partition wall 330 , a desiccant rotor 340 and a regeneration unit 350 .
The first casing 310 is a hollow body with its inlet 311 ′ and outlet 311 ″ opened at both ends. The inside space of the first casing 310 is divided into a first channel 311 and a second channel 312 by the second casing 320 disposed inside the first casing 310 .
The second casing 320 is a blocked hollow body. The partition wall 330 is disposed inside the second casing 320 . The partition wall 330 partitions off the inside space of the second casing 320 into third and fourth channels 321 and 322 in communication with each other.
The desiccant rotor 340 and the regeneration unit 350 correspond to the desiccant rotor 220 and the regeneration unit 230 explained above. Therefore, detailed explanations thereof are omitted.
As shown in FIG. 5 , the air conditioning apparatus 300 includes a condensing unit 360 in addition to the second embodiment shown in FIG. 4 . The condensing unit 360 condenses the moisture from the air flowing out of the desiccant rotor in the fourth or regeneration channel 322 . The air flowing out of the condensing unit 360 is decreased in the humidity due to the moisture condensation and is redirected to the regeneration channel 322 of the desiccant rotor 340 . With this embodiment, the regeneration air can be recycled to make the regeneration air channel in a closed circuit and the desorbed moisture from the regeneration of the desiccant rotor 340 is removed in the form of condensed liquid water by the condensing unit 360 , the condensed liquid water is collected in a water tank 390 which is detachably mounted on the second casing 320 .
The condensing unit 360 is a sort of heat exchanger for exchanging heat between the hot humid air from the regeneration side of the desiccant rotor and the relatively cool air branching from the return air stream through an independent air channel 312 . The hot humid air from the regeneration side is cooled by the relatively cold return air resulting in the moisture condensation. Consequently, the desorbed moisture from the desiccant rotor in the regeneration side is removed from the regeneration air at the condensing unit 360 .
A cooling unit 380 for cooling the air dehumidified by the desiccant rotor 340 corresponds to the cooling unit 250 described above. The dehumidified air from the desiccant rotor 340 is finally cooled by the cooling unit 380 and is supplied to an indoor space intended to be air-conditioned. Fans 371 and 372 for facilitating air flows in the casings 310 and 320 correspond to the fans 241 and 242 described above.
Differently from the air conditioning apparatus 200 , the air conditioning apparatus 300 recycles the air in the second casing or regeneration circuit 320 , and thus does not need to induce the outdoor air. When the air conditioning apparatus 300 is disposed indoors, the indoor air is taken through the inlet 311 ′ and discharged to the indoor space through the outlet 311 ″. That is, induction of the outdoor air is not required. As a result, holes are not bored through an outer wall of a building in the installation of the air conditioning apparatus 300 . In addition, as compared with the air conditioning apparatus 200 , the air conditioning apparatus 300 does not require the extension channel or ductwork 260 . Accordingly, the air conditioning apparatus 300 can be easily installed and disassembled.
FIG. 6 is a concept view illustrating an air conditioning system using the district heat supply.
Referring to FIG. 6 , the air conditioning system includes a dehumidification system 400 and a district heat supply system 500 .
The dehumidification system 400 is composed of a dehumidification or air conditioning apparatus 410 , a hot water circuit 420 and a heat exchanger 430 .
The dehumidification or air conditioning apparatus 410 installed in indoor space (house, workroom, etc.) is one of the dehumidification apparatus 100 and the air conditioning apparatuses 200 and 300 for supplying the dehumidified (and cooled) air to the space requiring air-conditioning. Such apparatuses 100 , 200 and 300 have been described above.
The dehumidification or air conditioning apparatus 410 is connected to the hot water circuit 420 to be supplied with the regeneration heat for the desiccant rotor 110 , 220 or 340 . The heat exchanger 430 transfers heat from the district heat supply system 500 to the hot water circuit 420 .
The district heat supply system 500 is a central energy facility such as a cogeneration plant. The cogeneration plant 500 stores waste heat generated by electricity generation in a thermal storage tank 510 . A heat exchanger 520 performs heat exchange with water. The water supplied with heat moves along a heat transfer line 540 connected to the heat exchanger 430 by a circulation pump 530 .
By this configuration, the waste heat can be supplied from the district heat supply system 500 to each space requiring air-conditioning, and used to dehumidify and cool the air. With this increased heat demand to supply air-conditioning in the summer, it is possible to operate the cogeneration plant 500 even in the summer which has not been normally managed due to large decrease in the heat demand in summer.
Another advantage of the present invention is that any additional installation of the water lines is not required for the embodiment of the present invention except the original hot water circuit for heating. It is thus possible to efficiently economically use the waste heat for air conditioning.
As the present invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, it should also be understood that the above-described embodiments are not limited by any of the details of the foregoing description, unless otherwise specified, but rather should be construed broadly within its spirit and scope as defined in the appended claims, and therefore all changes and modifications that fall within the metes and bounds of the claims, or equivalents of such metes and bounds are therefore intended to be embraced by the appended claims.
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Disclosed are a dehumidification apparatus, and an air conditioning apparatus and system having the same. The dehumidification apparatus includes: a desiccant rotor having a desiccant for adsorbing moisture; and a regeneration unit disposed at one side of the desiccant rotor, for desorbing the moisture adsorbed to the desiccant. The regeneration unit includes at least one of a hollow hot water line containing hot water exchanging heat with the air flowing toward the desiccant rotor. The dehumidification apparatus efficiently reproduces the desiccant for dehumidification and air conditioning.
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FIELD OF THE INVENTION
The present invention generally relates to a liquid cooling system for a motor vehicle and concerns, more particularly, the heat exchanger for a system of this type.
BACKGROUND OF THE INVENTION
Cooling systems, of the water cooling type, conventionally include a heat exchanger or radiator, in which the water which has been heated on contact with the engine circulates. The radiator is designed so as to have a maximum surface in contact with the air, and it is usually arranged to be perpendicular to the air flow path, either at the front, or at the rear of the vehicle. Generally of a rectangular shape, these conventional radiators constitute a resistance to the flow of air around the moving vehicle, which has a negative effect upon the drag coefficient (or Cx) and, consequently, the performance of the latter. For automobiles with an electric motor, it is particularly important to reduce to the minimum any energy loss as these limit considerably the maximum autonomy of the vehicles. Obtaining a very small Cx is a necessity for vehicles driven by an electric motor and intended to be able to reach speeds in the order of 100 km per hour. It is also highly desirable for the weight of the batteries, which store the basic energy, to be kept to a value as low as possible. The batteries constitute a non negligible part of the total weight of electrically controlled vehicles.
SUMMARY OF THE INVENTION
The invention thus has as an object a heat exchanger for a motor vehicle offering a lower air flow resistance than in the cooling systems of the prior art.
Yet a further object of the invention is an inexpensive heat exchanger for a motor vehicle.
Still a further object of the invention is an easy-to-install heat exchanger for a motor vehicle.
According to one feature of the invention, the heat exchanger for a motor vehicle liquid cooling system is produced to form of a hollow cylindrical cavity.
According to another feature of the invention, the heat exchanger is mounted in the motor vehicle so that its longitudinal axis is substantially parallel to the direction of the air flow in said vehicle.
According to a further feature of the invention the heat exchanger is mounted on a hollow tubular member which is connected to the motor vehicle chassis and forms an integral part of the latter.
The fact of using a heat exchanger with the features mentioned above enables the vehicle's air penetration coefficient to be improved by reducing the apparent surface of this exchanger in the direction of movement. Further, the exchanger may easily be mounted on a tubular member connected to the chassis, which considerably increases the heat exchanging efficiency between the cooling circuit and the surrounding air.
Other objects, features and advantages of the present invention will appear more clearly upon reading the following description of particular embodiments; said description being made by way of non limiting examples and in conjunction with the attached drawings.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 shows schematically a first example of a heat exchanger according to the invention arranged on a hollow cylindrical member connected to the chassis of a motor vehicle;
FIG. 2 shows, in cross-section, the heat exchanger of FIG. 1;
FIG. 3 shows, in perspective view of another embodiment example of a heat exchanger according to the invention;
FIG. 4 shows, in cross-section a first alternative embodiment of the mounting means of the heat exchanger of FIG. 3;
FIGS. 5a and 5b show, in cross-section, a second alternative embodiment of the mounting means of the heat exchanger of FIG. 3; and
FIG. 6 is a general schematic diagram of the cooling system.
DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 shows an example of a particularly advantageous application of the invention. It shows a part of a chassis as disclosed in U.S. Pat. No. 5,548,510. This chassis 3 comprises a rigid central beam 31 to which elongated tubular members 2 are fixed. The principal function of these tubular members is to form energy absorption zones by deforming themselves in the event of a frontal collision of the vehicle with an obstacle. Since they are hollow and arranged longitudinally in relation to the vehicle, air coming from outside naturally circulates therein when the vehicle is moving. According to the present alternative embodiment it is thus proposed to take advantage of this arrangement by arranging the heat exchanger comprising a sleeve 1 on one or more ends of said tubular members 2. In this way, advantage is taken of the flow of air in tubular member 2 and at the external surface of the latter to dissipate the heat carried by the cooling liquid circulating from the inlet 11 to the outlet 12 of heat exchanger 1. If tubular members 2 are made of a very good heat conducting material such as for example, aluminum or aluminum alloys, the heat exchange is correspondingly better and the contact surface between exchanger 1 and tubular member 2 may be reduced to a minimum.
FIG. 2 shows, in cross-section, a first embodiment of the heat exchanger mounted as indicated, in FIG. 1. As illustrated in FIG. 2, exchanger 1 has the general shape of a sleeve and consequently does not form a closed cavity. It is thus able to use the external surface of tubular member 2 as an internal wall (when mounted). The direct contact of the cooling liquid with the surface of the tubular member increases the heat exchanging efficiency. The water tightness of the cooling circuit is assured by the O rings 13 and 14. Annular grooves 21 and 22 may be made on the external face of tubular members 2 in order to assure exchanger 1 is maintained in position. In order to enable a good exchange of heat, even when the vehicle is stationary or moving slowly, a fan 30 may be provided to increase the circulation of air in tubular member 2. This fan may for example be conventionally controlled by a thermostat (not shown) arranged in the cooling circuit or in the engine-block of the vehicle.
FIG. 3 shows a heat exchanger according to the invention viewed in perspective. In the preceding figures, the heat exchanger was shown with flat external surfaces for the sake of simplification and also, for the purposes of showing that the preferred heat exchange surface is the one in contact with tubular member 2. All the faces of the exchanger participate in this exchange of heat and, in order to increase the exchange surfaces, it is advantageous to form the exchanger in such a way that its external surfaces have an corrugated profile, as is shown. An exchanger of this type may easily and inexpensively be produced in sheet metal pre-formed by rolling or by pressing and welding. The inlet 11 and outlet 12 nozzles may also be welded onto the principal body of heat exchanger 1.
FIG. 4 shows, in cross-section, an alternative embodiment of the means for mounting the heat exchanger of FIG. 3. According to this alternative, the interior edge 130, which is intended to come into contact with tubular member 2, is formed so as to have two annular, hollow embossings 131 and 132. These two embossings are provided for receiving two O rings 13.a and 13.b which will assure the water tightness of exchanger 1. Further, part 133 of internal edge 130 is designed so as to be able to be deformed by the action of a pressure P; the effect of said deformation being to apply ring 13.b onto the external surface of tubular member 2. This part 133 is represented in FIG. 3 by an unbroken line in its original form and position and in a dotted line in its final form and position. Mounting an exchanger of this type comprises the following steps. The exchanger is initially positioned on tubular member 2, the leak proofness being at this stage partially assured by O rings. 13.a. Next, pressure P is generated inside the exchanger, by filling the latter with the aid of a gas or a liquid, in order to deform parts 133 so as to apply O rings 13.b to the external surface of tubular member 2.
FIG. 5 shows, in partial cross-section, another alternative embodiment of the heat exchanger according to the invention provided with mounting means involving only one O ring for each side of the exchanger. According to this alternative, the internal edges 140 and 150 are formed so as to have a first annular hollow embossing 141 and 151 respectively, and a second annular hollow embossing 142 and 152 respectively. Said second embossings have an inclined section 144 and 154 respectively, and stopping means 143 and 153 respectively. The mounting of this exchanger is carried out in the following manner. Heat exchanger 1 is initially positioned on tubular member 2 in the direction of the arrow I (FIG. 5.a); O rings 13 and 14 having, initially, been placed in said second embossings 142 and 152. During this first phase, the O rings are prevented from coming out of said second embossings by stopping means 143 and 153. Then, in a second phase, a movement backwards of the exchanger (in the direction of the arrow II), causes the relative displacement of O rings 13 and 14 towards said first the embossings 141 and 151. The inclined sections 144 and 154 facilitate the movement of the O rings towards their definitive position illustrated in FIG. 5.b.
In the previously described application examples, it has been considered that there already existed at least one tubular member on which said heat exchanger could be mounted. It is obvious that in such a case, the solution of the invention is particularly advantageous since not only do the tubular members enable said heat exchangers to be mounted easily, but the effect of their attachment to the vehicle chassis is to increase the heat exchanging capacity. Further, the production and assembly costs of such heat exchangers are particularly low. However, it should be understood that the heat exchanger according to the invention may also be advantageously used in vehicles which do not use such tubular members. The heat exchangers must then be arranged so that a sufficient flow of air is produced on the exchanging surfaces; namely the internal and external surfaces. Because of its shape and provided that it is arranged in such a way that its axis is substantially parallel to the direction of the air flow, the air resistance offered by the exchanger will be minimum and the drag coefficient (Cx) will only be slightly affected. It goes without saying that, for a given heat exchanging capacity, the total surface of the exchanger which is not mounted on a chassis member will be substantially greater than that of the exchanger mounted on a tubular member. Finally, if tubular members are not used to mount said exchangers, the latter will, of course, be realised in the form of a completely closed cavity.
FIG. 6 shows, schematically, a complete cooling system for a motor vehicle. comprising, for example, a heat engine and an electric motor.
This system comprises a liquid cooling circuit (generally water with additives, such as antifreeze) 100, which circulates in the electric motor 70, passes through a first 1 then a second 1' heat exchanger, cools the power components of an electric motor 50 and passes through a circulation pump 60. A temperature sensor 80, arranged in the cooling circuit, is also provided, whose output is used by a control circuit 90 to start the operation of fans 30 and 30' when this temperature becomes excessive. The diagram of FIG. 6 shows only one example among many of a water cooling system able to be used in motor vehicles. It should also be noted that other components may need to be cooled such as, for example, the components of the braking mechanism.
Although the present invention has been described in relation to particular embodiments, it will be understood that the invention is not limited to the described embodiments which may be varied and modified without departing from the scope of the invention as defined by the appended claims.
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A heat exchanger for a motor vehicle cooling system includes a sleeve-like meter heretically mounted on, and surrounding, a hollow tubular chassis meter of the vehicle. The sleeve is provided with inlets and outlets communicating with the space between the sleeve and the chassis meter and vehicle coolant flows through the inlet and outlet. Air, flowing over the outside surface of the sleeve and the inside surface of the chassis meter, cools the vehicle coolant.
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BACKGROUND OF THE INVENTION
The present invention represents a particular apparatus related to a spatial structure which can be obtained, preferably but not necessarily, by means of a pneumatic lifting system and is composed of extendable modular elements, coupled to the nodes by means of spherical hollow hinges, all the elements being assembled on a substantially plane level on a membrane fixed to a perimetral foundation ridge or the like.
In a previous patent application (Italian application No. 49254 A/79 filed on May 30th, 1979, in the name of Dante Bini), which is included herein as reference, a method is illustrated for performing a covering, preferably domeshaped and pneumatically erected, which is substantially constituted by a plurality of rod-like elements which are assembled and connected at their end to non-spherical nodes and rigidly fixed to a membrane anchored peripherally on a planar surface which in practice delimits the covering region. In said application, variable-length rod-like elements are furthermore provided which are still assembled on a base plane, coupling their ends to connecting nodes, the rod-like elements having a limited possibility of articulation with respect to the nodes, during the phase of automatic raising. After connecting the various rod-like elements and the nodes by preassembling on a base plane, an erection of the supporting structure of the covering is provided by means of a pneumatic action or the like, acting on said membrane so that, in reaching the desired configuration, the variable-length rod-like elements extend telescopically until they reach a selected length, by rotating about their own axis, but not about the geometrical center of the node.
When the present length has been reached, locking means intervene which are directly provided in the rod-like elements, and prevent said elements from assuming a length which differs from the preset one.
With the above described arrangement, the various rod-like elements, assembled beforehand on a base plane, allow to achieve a precise automatic positioning thereof to provide a specific spatial structure substantially in the shape of a dome or of a vault and pneumatically erected.
In the above mentioned patent, the connection between the known rod-like elements of the non-spherical type is generally provided by means of complex elements with different shapes which lock into or insert in corresponding specifically provided seats.
The various embodiments illustrated in the previous patent have proved to be susceptible to improvement, especially regarding the possibility of allowing a complete freedom of articulation between each rod-like element and node, and the possibility of giving the absolute assurance of preserving the concentricity of the axes of all the rodlike elements with the corresponding geometrical centers of the nodes, no matter what the angle of incidence, furthermore allowing a remarkable constructive simplicity of the components.
Another limitation which can be found in the solution illustrated in said patent application resides in the fact that, especially in bad weather, the covering membrane, which is rigidly coupled to the assembly of the node, can transmit directly to the metallic structure stresses and vibrations which are capable of triggering moments which can be harmful to the local stability of the rod-node assembly, due to the lack of concentricity of the axes of the rods with respect to the geometrical center of the node as the angle of incidence of the axes of the rod-like elements varies with respect to the vertical axis which passes through the center of the nodes.
SUMMARY OF THE INVENTION
The aim of the invention is indeed to eliminate the above described disadvantages by providing a reticular structure for variable geometries, including the global ones which can be contained in spherical shapes and preferably with pneumatic forming, which offers the advantage of greatly facilitating all the steps of making the components, their assembly, raising the structure, disassembly of the components and their possible recovery for other purposes or future uses of the same structure.
Within the scope of the above described aim, a particular object of the present invention is to provide a reticular structure, provided with a more efficient and simplified perimetral anchoring/connection node for the various rod-like elements connected thereto and which, even when the structure is erected, can be replaced or makes it possible to replace or eliminate one or more rod-like elements connected thereto, with the possibility of facilitating their locking once the designed preset position has been reached.
The aim described above, as well as the objects mentioned and others which will become apparent hereinafter, are achieved by a reticular spatial structure preferably pneumatically erected, composed of modular elements, according to the invention, comprising a plurality of perimetral rod-like elements associable, at their ends, with perimetral nodes, a plurality of variable-length rod-like elements pivotable, at their ends, to connecting nodes provided, like the perimetral nodes, with a spherical contact surface adapted to allow the rotation of at least part of said variable-length rod-like elements both about the axis of said elements and with respect to the geometrical center of the various nodes, for the extension of said variable-length elements during the pneumatic raising of the framework preassembled on a substantially horizontal base plane for the formation of a reticular spatial structure, preferably but not necessarily in the shape of a dome, locking means being furthermore provided to prevent the return of said variable-length rod-like elements to lengths which differ from the intended final extension lengths, characterized in that said connecting nodes comprise a lower plate and an upper plate securing a pneumatic raising membrane used as covering and coupled to the interior of the connecting node suspended rocker-like to a hollow body having at least two concentric walls shaped like a spherical crown without the polar caps, said walls being provided with a plurality of openings in the equatorial regions which allow the rod-node connection, the locking of the ends of said rod-like elements being possible, once the pneumatic raising has occurred, since the interior of the node is accessible because of the lack of its upper cap or by removing a cover.
BRIEF DESCRIPTION OF THE DRAWINGS
Further characteristics and advantages will become apparent from the description of a number of preferred, but not exclusive, embodiments of a reticular spatial structure, illustrated only by way of non-limitative example in the accompanying drawings, where:
FIG. 1 is a schematic view of the structure according to the invention during the assembly phase, on a pneumatic seal membrane, on a plane before the erection to produce a preferred dome-like geometry, in this case with an hexagonal base;
FIG. 2 shows a schematic prospect of a dome with reticular spatial structure, according to the invention;
FIG. 3 is a schematic exploded perspective view of a connecting node;
FIG. 4 is an exploded perspective view of a variablelength rod-like element;
FIG. 5 is a view of an automatic locking means;
FIG. 6 is a diametral cross section view of a connecting node comprising the rocker supporting apparatus for the membrane and with the end of a rod-like element applied;
FIG. 7 is an exploded cross section view of a connecting node;
FIG. 8 is a plan view, in partial cross section, of a connecting node;
FIG. 9 is a view of a connecting node from the opposite side;
FIG. 10 is a schematic perspective view of a plinth for anchoring a perimetral node to the foundations;
FIG. 11 is a cross section view of a perimetral node coupled to said plinth;
FIG. 12 is a partial cross section view of a perimetral rod-like element;
FIG. 13 is a cross section view of a variable-length rod-like element before its extension in length;
FIG. 14 is a cross section view of a rod-like element once it has reached its preset working length;
FIGS. 15 and 16 are enlarged scale views of the locking means respectively before and after the extension has occurred;
FIG. 17 is an exploded perspective view of another aspect of the rod-like element with variable working length;
FIG. 18 is a detailed view of the rod-like element illustrating the locking means during their action phase;
FIG. 19 is a view of the locking means once the locking has occurred;
FIGS. 20 and 21 are views of the attachment body of the rod-like elements with a device for performing the final extension.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to the above described figures, the pneumatically erected reticular spatial structure, according to the invention, comprises a plurality of perimetral rod-like elements, indicated by 1, which advantageously but not necessarily are of the fixed-length type, and at their ends are coupled to perimetral nodes, generally indicated by the reference numeral 2, after arranging the lower plates 12a on the resting plane according to the preset geometry.
As schematically indicated in FIG. 1, the structure is arranged on a base plane on a membrane 13, anchored peripherally to the pneumatically sealed foundations, arranging the rod-like elements 1 according to a geometrical pattern provided by the project and connecting them to the perimetral nodes.
The reticular structure, according to the invention, furthermore comprises variable-length rod-like elements, generally indicated by the reference numeral 10 which also, at their ends, are articulated to connecting nodes 11 with the possibility of rotating about their own axis of rotation with respect to the geometrical center of said connecting nodes; furthermore, part of the rod-like elements 10 are articulated also to the perimetral nodes 2, so as to create, in practice, a plane grid applied both to the membrane 13, at selected points, and to the perimetral foundation plinths.
As illustrated in detail in FIG. 6 and in the subsequent figures, the entire apparatus of the connecting node 11 is provided with a lower plate 12a and with an upper plate 12b securing the membrane 13 between themselves by means of a threaded connecting pivot 14 suspended, rockerlike, from the node.
For the sake of descriptive completeness, it should be furthermore added that the plates 12a and 12b are provided, on their face connecting the membrane 13, with annular recesses, indicated by 15, which facilitate the adhesion of the membrane to the plates, in order to ensure a waterproof connection.
The pivot 14 is suspended from the hollow body, indicated by 20, which is substantially composed of a lower base 21 and of an upper base 22 connected to a wall having the inner and outer surfaces shaped according to concentric spherical surfaces.
The lower base 21 defines, in the region of coupling to the pivot 14, a coupling seat 25 shaped like a spherical portion, in which a complementarily shaped nut 26 engages and allows a variable positioning of the hollow body 20 with respect to the pivot 14.
It should be furthermore added that a ring 26 of elastically deformable material is interposed between the lower base 21 and the upper plate 12 and acts as a shock absorber, absorbing part of the vibrations transmitted by the membrane to the metallic structure.
A plurality of openings 30 is provided on the wall 23 for the passage of the locking bolts 34 required to lock the ends of the rod-like elements 10. For this purpose, the rodlike elements 10 are provided with a terminal body 31 which defines a spherical seat 32 in the region of coupling to the wall 23 which has a curvature matching the curvature of the node spherical surface, so as to achieve a stable coupling also when the angle of the terminal body with respect to the node varies.
Similarly, inside the hollow body 20 a shaped body 33 is provided which has a spherical configuration in the region of contact to the inner surface, so as to ensure a perfect coupling also of the surfaces in contact inside the node, as the angle of incidence of the terminal body with respect to the node varies.
The upper base 22 is screwed to the hollow body 20 so as to be removable and to permit access to the bolts 34 for the final locking in the preset position of the various rodlike elements once their extension is completed to reach the preset length after the structure has been erected.
The structure can be raised, as previously mentioned, by pneumatic means, but conceptually nothing varies if it is raised by means different from pneumatic ones, such as for example, by means of cables, jacks or other mechanical systems.
The various variable-length rod-like elements 10 have a tubular body, indicated by 40, which, at least at one end, defines a threaded portion 41 with which a ring nut 42 engages. The ring nut 42 is provided with an abutment 43, which, in cooperation with the end of the tubular body 40, defines the snap coupling seat 44 for a locking means which is advantageously constituted by a split elastic ring 45 housed in a piston-like body 46 which is slideable within the tubular body 10. The elastic ring 45 is positioned on the body 46 on the opposite side with respect to the terminal body 31
A threaded portion 47 is provided in the region of coupling between the piston body 46 and the terminal body 31, and a locking nut 48 is engaged therein once the desired extension has been performed.
In practice, as is better illustrated in FIGS. 13 and 14, in assembly conditions the piston-like body 46 is housed in the tubular body 40 and supports the elastic ring 45.
Once the the rod-like element has been extended following the raising of the structure pneumatically or by other means, the ring locks in the coupling seat 44 defined by the abutment 43 and by the end of the tubular body 40 thus preventing any further axial motion of the tubular body with respect to the piston-like body.
In FIGS. 17, 18 and 19, it is illustrated a rod-like element with variable working length, according to another aspect of the invention.
In practice, an outer tubular body 60 has, at one of its ends, an outer threaded portion 61 engaging a sleeve 62 which inwardly defines an abutment or sleeve abutment 63 delimitating, with the end of the outer tubular body 60, a seat 64 in which split elastic rings 65 are provided acting in compression. On the elastic rings 65 act the threaded means 66 arranged outside the sleeve 62 to radially compress the rings 65.
An inner tubular body 70 is accommodated inside the tubular body 60 and defines a piston-like portion 71 providing a locking seat 72 in which said elastic rings 65 are locked to prevent the reentry of the inner tubular body 70 once it has been extended to the preset length.
In some cases, it may happen that the rod-like elements cannot extend completely to reach the preset length, so that the elastic locking rings do not insert in the related seat; to make this insertion possible in any case, a device for performing the final extension can be provided as illustrated in FIGS. 20 and 21.
Such a device comprises a threaded sleeve 80 which is connected to the terminal body 81 and engages rotatably with a threaded portion 83 defined by the tubular element 82.
The threaded sleeve 80 is provided with a diametral hole 84 which is engageable by a tool to rotate the sleeve so as to "pull" the tubular element 82 until the snaptogether coupling of the elastic rings is achieved.
Furthermore, an element for locking the reentry of the tubular element 82 is provided, which consists of a diametral body 85 diametrally supported by the tubular element 82. The body 85 has a minimum length such as to be included in the dimensions of the tubular element 82 and is extendable to engage in abutment with the sleeve provided on the outer tubular element. For this purpose, the body 85 is composed of a first part 85a and of a second part 85b with a mutual coupling of the bolt-threaded seat type.
It should be furthermore added that the perimetral nodes 2 can be made similar to the nodes 11, assembling them in such a way as to make them capable of oscillating in order to assume the correct position, or possibly a hollow body 20 can be fixed with a preset inclination to an upper base plate 50 which, by means of the locking tension elements 51, locks onto a lower base plate 52 which can be connected to a plinth for anchoring to the ground or to the perimetral foundation ridge.
In practice, in the assembly, after arranging the suspension plates 12a on the resting plane, a plane reticular structure is applied to a membrane 13 which is peripherally anchored and pneumatically sealed, by connecting to one another the perimetral nodes of the foundations of the rod-like elements 1, as well as variable-length rod-like elements 10 to the connecting nodes, according to a preset pattern, then air is forced below the membrane, performing the gradual raising, which, as already mentioned above, can also be achieved with different means
During the raising of the structure, the rod-like elements 10 extend and rotate both about their own axis and about the various geometrical centers of the connecting nodes until, once the preset working length has been reached the rod-like elements lock at the set position.
Once the desired structural configuration has been achieved, the ring nuts of the locking nuts and of the various rod-like elements are tightened, and then the rod-like elements are locked with respect to the nodes by using the bolt 14 which can be reached from the interior of the hollow body 20, thus achieving also the locking at all the nodes.
From what has been described, it can be seen that the invention achieves the proposed aims, and in particular the fact is stressed that the reticular structure, according to the invention, has a remarkably easy assembly, due to the presence of components similar to one another, composed of nodes and variable-length rod-like elements, which have the possibility of reaching a preset length during the pneumatic raising.
Moreover, the system makes it possible to release quickly the various lockings in order to recover the elements at a substantially plane level, preferably through a pneumatic disassembly.
It is furthermore specified that the variable-length rod-like elements can be provided, according to the requirements, either with both ends extendable or with one fixed end and with one extendable end.
It has been furthermore observed that it is possible to use a limited variety of rod-like elements since the various rod-like elements all have the same central portion constituted either by the tubular body 40 or by the outer tubular body 60 and, according to the working length needed, just the length of the terminal body 31 has to be modified.
The invention thus conceived is susceptible to numerous modifications and variations, all of which are within the scope of the inventive concept.
Moreover, all the details may be replaced with technically equivalent elements.
In practice, the materials employed, so long as compatible with the specific use, as well as the dimensions and the contingent shapes, may be any according to the requirements.
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A reticular spatial structure comprising a plurality of perimetral rod-like elements which are associable, at their ends, with perimetral nodes; a plurality of variable-length rod-like elements hinged to connecting nodes having a spherical contact surface adapted to allow the rotation of at least part of the variable-length rod-like elements both about the axis of said elements and with respect to the geometrical center of the various nodes, for the extension of the variable-length elements during the raising of the framework which is preassembled on a base plane. A connecting node comprises a lower plate and an upper plate securing a covering membrane, which can be fixed to a rocker suspension pivot connected to a hollow body having both the outer surface and the inner surface in the shape of equatorial segments of concentric spheres. The hollow body is provided with openings for the insertion of the node-rode fixing bolts.
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NOTICE OF RELATED APPLICATION
This patent application is a continuation in part of U.S. patent application Ser. No. 07/434,068 filed on Nov. 8, 1989, now abandoned, which is a continuation in part of U.S. patent application Ser. No. 07/364,917, filed on Jun. 9, 1989 now abandoned.
FIELD OF THE INVENTION
The present invention relates to connectors for coaxial cables. More particularly, the present invention relates to a very low cost, easily installable feedthrough connector for coaxial cable of the type typically used indoors for wideband RF signal distribution, for example.
BACKGROUND OF THE INVENTION
Coaxial cable is in widespread use for distributing wideband radio frequency ("RF") information, such as television and radio signals. Coaxial cable typically provides two conductors, a central axial conductor and an outer conductor which is substantially concentric with the inner central conductor. The central conductor is typically completely surrounded by the outer conductor, and a low-loss, high dielectric insulation material, such as plastic foam, separates the two conductors. An outer insulating jacket is usually, although not necessarily, provided over the outer conductor to provide electrical insulation and physical protection to the cable. The outer conductor may be a single element, or it may be a composite of several layered elements of conductive foil, wire braid, etc. One element of a composite outer conductor construction may be a conductive film or coating applied to the outside surface of the low-loss, high dielectric insulation material.
Relatively large diameter, semi-rigid coaxial cables are widely used outdoors in cable television distribution networks as a delivery conduit for delivering the cable network signals to drop box locations near the service subscriber's premises. Smaller, more flexible coaxial cables having external insulating jackets are used to provide service drops to the subscriber premises.
Connectors are provided for connecting the cables in the outdoor environment. Such connectors not only must provide positive, signal-tight electrical connections, they must also provide positive leak-tight, sealed physical connections to prevent intrusion of moisture into the cable. Installation of such connectors typically requires cable end preparation such as coring or removal of the insulator dielectric core for some distance, followed by installation and tightening of the conductor assembly by a trained craftsperson, with or without special tools, depending upon the conductor/cable design. Typically, the outdoor environment connectors provide a central connector element which is secured in coaxial arrangement over an exposed end portion of the central conductor. The central connector element thus contributes significantly to the securement of the connector structure to the prepared cable end.
Usually, the distribution network operator does not want a subscriber to install a connector to a cable for use with "outside plant" distribution boxes, cables and the like; thus, special keyed tools are often provided for use by trained installers in order to preclude unauthorized access to system distribution boxes, service drops and the like.
Within the subscriber premises the opposite situation often exists. Usually, the subscriber has a number of appliances which require interconnection and connection to the service cable outlet jack, typically mounted to and extending outwardly from a wall plate within the home or other interior location, etc. Connections may be needed between the service jack and the jacks of a television set, a video cassette recorder ("VCR"), and a stereo FM receiver, for example.
Small diameter (approximately one quarter inch or smaller), flexible coaxial cables are typically employed to accomplish the needed connections. These coaxial cables typically include a solid wire central conductor, a foam core, an outer composite conductor formed of an inner aluminum coating on the foam core, one or more layers of open-mesh aluminum wire braid and one or more layers of an aluminum foil. The outer composite conductor is typically covered by a plastic outer insulator jacket of one or several layers of insulating material in order to complete the coaxial cable construction. The dimensions of such coaxial cables may vary, depending upon type and source thereof. Also, the properties of the cable may vary, depending upon type and source, and also depending upon such factors as ambient temperature. When ambient temperature is low, the polymer cable materials become very stiff and difficult to manouver during connector installation procedures. Also, the foil coated inner insulating core may vary in diameter from about 0.140 inch to as much as about 0.200 inch.
These small diameter cables have been made available to the consumer in standard lengths with connectors installed at the factory. Also, connectors have been made available for installation, but installation of these connectors to a prepared cable end has typically required a crimping tool for crimping a retaining ferrule, or a tool for spreading a retaining slip ring, or the tightening of a compression nut which retains the connector to the cable end, or the like. Some connectors for indoor service provide and require compressive coaction between the face of the threaded jack and the connector body, which is achieved in practice by tightening a threaded nut of the connector over the outer threads of the jack.
The connectors for indoor service are known as "feedthrough" connectors, in h sense that there is no separate central connector element of the connector provided for connection, the center conductor of the cable providing this element of the connection mechanism. The center conductor is usually engaged by a receptacle element of a jack. Such element, sometimes referred to as a center seizure mechanism, when present, provides a positive mechanical engagement between the connector assembly and the center conductor of the coaxial cable.
In the case of the feedthrough connector, an exposed end portion of the solid wire central conductor of the coaxial cable is directly engaged by the center seizure mechanism of the jack when the feedthrough connector is mounted thereon. Since the central conductor of the coaxial cable is not maintained in mechanical engagement with the feedthrough connectors, and since those connectors function only to feed or connect the outer conductor to the jack and thereby to position the exposed central conductor for engagement with the central gripping mechanism of the jack, the prior techniques for securing the connector to the cable have proven to have drawbacks related to installation and have proven not to be entirely satisfactory for ready installation and extended, reliable use within indoor use environments.
Irrespective of the particular approach followed by the prior art, hitherto there has not been a very low cost feedthrough coaxial cable connector which may be easily assembled and attached to the cable with a simple manipulation by a user without special tools, or skills, and which provides a positive, superior engagement over time with the jack to which it is mated for use.
A wide variety of techniques are to be found in the coaxial cable connector art for attaching a feedthrough connector to a prepared cable end. One representative example is to be found in the Quackenbush U.S. Pat. No. 3,781,762. Therein, a tubular connector body includes an annular flare. The body is dimensioned to fit between the insulating core and outer conductor of the prepared cable end, and it aligns and positions an exposed end section of the central conductor. The annular flare of the tubular body causes the outer conductor to become stretched over it as the body is pushed between the core and the outer conductor during installation. A cylindrical ferrule, such as a split ring or crimp ring, is then installed over the body inside of the annular flare. The Quackenbush arrangement is said to provide good electrical and mechanical connection of the cable outer conductor to the connector body. However, the Quackenbush connector cannot be easily installed on the prepared cable end without special tools needed for installation of the clamping ferrule.
As mentioned, another feedthrough connector relies upon a compression engagement obtained by tightening a threaded nut to the jack. The tightened nut of the connector compresses the outer conductor against the connector body and thereby secures the connector to the cable. One drawback of this approach is that when the nut is not tightened upon the threaded jack, or when the connector end is not engaged with the jack, a slight tug or jerk on the connector may cause it undesirably to become separated from the cable.
Other more conventional approaches are to be found in the coaxial cable connector art which include means for engaging the exposed end of the central conductor. For example, British Patent Specification 621,459 describes a tubular connector body for insertion between the insulation core and the outer conductor of a coaxial cable. An annular flared or bulged region expands the outer conductor of the cable, and a longitudinally extending split ferrule tube is pushed over the coaxial cable end to surround the body at the bulged region so as to press the cable against the bulged region to improve electrical connection and mechanical attachment. The ferrule includes fingers enabling it to be secured to the connector body after it is positioned in place.
An annular split ring is described in the Leeper U.S. Pat. No. 2,805,399 in order to retain an outer conductor of a coaxial cable along an arrow ring location immediately adjacent a bulged annular frustoconical clip portion of a body which is slipped under the outer conductor of the coaxial cable in order to provide very secure mechanical retention of the cable to the connector. Here, a special tool is needed in order to position and install the slip ring.
In the Pugner U.S. Pat. No. 4,053,200, a connector body has two radially raised portions. A plural-fingered, elongated brass ferrule slides over the cable and the outer radially raised portion in order to seat or nest between the two raised portions of the body and press the outer conductor of the cable against the connector body. While the elongated brass ferrule provides a radial band of circumferential compression force to press the cable outer conductor against the tubular body, similar to the manner described in the Quackenbush reference discussed above, no engagement is provided between the elongated ferrule or other structure of the connector and the cable behind the outer raised portion of the connector body. Apparently, to aid requisite securement of the cable to the connector, the Pugner reference teaches a central connector structure which is crimped or otherwise secured to an exposed end section of the central conductor of the cable.
Without the further retention means by the central connector structure as shown in the Pugner patent, tugging and pulling stresses upon the coaxial cable will tend to cause it to become disconnected from the connector as described by Pugner, especially if the connector is threaded onto the jack at the time. Also, any flexures of the cable, particularly within an indoor environment such as the home, will tend to cause the outer conductor to stretch and possibly to lose effective electrical contact with the ridge of the outer raised portion and/or provide an unwanted signal leakage path at the connector.
The Schwartz U.S. Pat. No. 3,264,602 provides a connector body for a coaxial cable which has a rearwardly tapered, ringed frustoconical surface which is slipped under the outer conductor of the coaxial cable. An outer member snap-locks over the cable in a manner which compresses the outer conductor against the frustoconical surface in order to lock the cable to the connector and to provide a positive electrical connection between the inner surface of the outside conductor of the cable and the facing frustoconical ringed surface of the conductive connector body.
The Lee U.S. Pat. No. 4,789,355 provides a coaxial cable connector plug which has tines or leaves which slide over the threaded end of the jack. An outer annular sleeve may then be pushed forward over the tines in order to compress them against the threaded jack and lock the connector plug against the jack in the manner of a compression collet, even though the plug is not threaded to mate with the threads of the jack.
The Samichisen U.S. Pat. No. 4,834,675 describes what the inventor calls a "snap-n-seal" coaxial cable connector for a prepared end of a coaxial cable. This four-part connector assembly includes a mandrel body 30 which has a ramped contour 39 diverging from the rear end thereof, so that the body 30 may be press fit between the dielectric core and the shielding braid. As seen in FIG. 2B and as best seen in FIG. 4, the ramped contour 39 appears to flatten out and ends at a step inwardly forming a right angle with the flattened region. A plastic compression sleeve 60 is pushed over the body 30 and the cable end. The compression sleeve snap-locks into a metal collar member 20 and is said thereby to lock the cable end to the connector assembly. Since the ramped contour 39 appears to end at a flattened region, the body 30 fails to provide a knife edge for effectively cutting into the braid or aluminum sheet forming the outer conductor of the coaxial cable.
The Ito et al. U.S. Pat. No. 4,249,790 describes a push-on type connector plug for a coaxial cable end. In pertinent part, the connector plug includes a slotted shield casing forming a plurality of resilient fingers which engage the outer cylindrical surface of a connector receptacle as the connector plug is pushed onto the receptacle. The fingers appear to be contoured to cooperate with an outer band structure in order to provide a spring bias force which pushes the fingers against the outer cylindrical surface of the receptacle and thereby provide a good electrical and mechanical push-on, pull-off attachment.
The Morello Jr. U.S. Pat. No. 3,196,382 describes a crimp type coaxial cable connector 12 which includes a mandrel body having an integrally threaded mating cap for mating with a receptor connector 14. The Morello Jr. connector device is not a push-on feedthrough connector.
While the foregoing approaches recognize the problem of providing effective contact and positive mechanical attachment of the prepared cable end and the cable connector, none of the foregoing approaches achieve a simplified, easily installed, positively acting feedthrough coaxial cable connector intended primarily for ready installation by the untrained user or consumer or by the trained technician, and for reliable use typically within an indoor environment over an extended time period.
SUMMARY OF THE INVENTION WITH OBJECTS
A general object of the present invention is to provide a feedthrough coaxial cable connector which overcomes the limitations and drawbacks of the prior art.
A more specific object of the present invention is to provide a feedthrough coaxial cable connector for indoor use which may be installed by a user with exertion of but moderate finger strength and without any special tools or skills being required.
One more specific object of the present invention is to provide a feedthrough coaxial cable connector which achieves improved flexual strain relief against rearward pulling force thereby to prevent the cable from being disconnected from the connector in response to tugging or pulling forces whether or not the connector is pulled free of the jack. That is to say, a specific object of the present invention is to provide a feedthrough coaxial cable connector which preferentially releases from a jack with which it is mated, rather than becoming damaged and inoperative by separation of the connector and the coaxial cable end.
Yet another specific object of the present invention is to provide a kit of a few co-acting parts which may be assembled and installed by the consumer as a connector on an easily prepared end of an indoor coaxial cable by hand without special tools and without special training or skills.
Still a further specific object of the present invention is to provide a retenton ring having a resiliently deformable portion of elastomeric material which coacts with an annular or helical blade edge forming an annular or helical barb of a mandrel body underlying the outer conductor, so that once locked in place, the resiliently deformable portion of the retention ring effectively locks the cable onto the connector and impedes rearward tugging forces from causing the cable end to be detached from the connector.
Yet one more specific object of the present invention is to provide a mandrel body for a coaxial cable connector which has an annular or helical blade edge forming a sharply contoured surface projecting outwardly from a substantially tubular mandrel body portion, and to use an elastomeric retention ring to cause an aluminum foil and braded wire portion of an outer conductor of the coaxial cable to be contacted by the blade edge in a way which fosters positive long term connection to the foil and braded wire conductor elements without formation of insulating oxides and without actually shearing the fine wires of the outer conductor braid, so that the connector will operate reliably throughout wide ranging temperature cycles of the ambient surroundings and without impairment resulting from occasional movement and tugs on the cable.
Still one more object of the present invention is to provide, most preferably by die casting, a mandrel body including a tubular portion defining an annular or helical blade edge forming a sharply contoured surface projecting outwardly from the tubular portion. The tubular portion may be formed to act as a collet in order to engage differently dimensioned coaxial cables within a predetermined dimensional range. In this object ramping is effectively promoted with the aid of an expendable conically shaped guide for providing a ramp between the different cable diameters.
Yet one more object of the present invention is to provide a nesting tool for containing a kit of parts comprising the elements of the cable connector in a manner which facilitates proper and ready assembly of the elements into an installed feedthrough connector at the prepared end of a coaxial cable.
A feedthrough coaxial cable connector is provided for connecting to a prepared end of a coaxial cable having an exposed solid-wire central conductor. In accordance with the principles of the present invention, the connector includes a tubular mandrel body of conductive material such as yellow brass which has been plated with a suitable metal or alloy, such as tin, in order to improve lubricity, for example. The tubular mandrel body is dimensioned to be pressed between a foil-bonded dielectric core and other elements of an outer conductor of the prepared end of the cable.
In one presently preferred embodiment, the mandrel body preferably includes a rearwardly converging, generally frustoconical surface portion defining a shallow angle with respect to the cable, a first radial wall portion defining a knife edge with the frustoconical surface portion, a tubular shank portion extending from the first radial wall portion to a second radial wall portion, and a jack engagement portion coaxial about the exposed central conductor and dimensioned to fit on and contact an outer surface of a jack with which the connector mates in use. The jack engagement portion is preferably adapted to diverge radially from the second radial wall portion thereby enabling an initial slide-on engagement with the outer surface of the jack. A tight friction fit is desireably achieved between the jack engagement portion and the outer surface of the jack. In one preferred form, the jack engagement portion defines an inside compression collet structure. Preferably, the mandrel body is formed by die casting, in preference to machining.
In another aspect the mandrel body preferably includes a helical barbed thread extending radially outwardly therefrom in the nature of a shallow, spaced apart continuous thread of controlled sharpness to enable the mandrel body to be rotatably inserted onto the prepared cable end by threading into the underside of the outer conductor, thereby to establish a positive electrical connection, as well as a positive mechanical connection, but without actually shearing the fine wires typically forming at least a part of the outer conductor.
A radial compression providing structure, which preferably may include a flanged or splined snap-ring, includes a resiliently deformable elasomeric portion which is shaped and dimensioned to cause an inside surface region of the outer conductor to bear directly against and bend over the knife edge barb formed by the first radial wall portion at the inside end of the frustoconical portion of the mandrel body.
Preferably, a slideable shell is disposed over at least the jack engagement portion of the mandrel body. The shell is slideably positionable generally away from a connector end facing the outer surface of the jack to enable the jack engagement portion of the connector to slide over the outer surface of the jack, and is slideably positionable toward the connector end so as to radially compress the radially diverging jack engagement portion against the outer surface of the jack to enable the the connector to be securely connected thereto in a positive friction fit.
In one aspect of the present invention, the slideable shell further defines a radial portion for compressing a region of the coaxial cable outer conductor against the frustoconical surface portion of the mandrel body when the slideable shell is slideably positioned toward the connector end.
In another aspect of the present invention, the jack engagement portion is slotted longitudinally to form a slip ring for slideable engagement over the outer surface of the jack.
In a further aspect of the present invention, the jack engagement portion includes plural slots, and it functions as a compression collet to lock onto the outer surface of the plug as the slideable shell is positioned toward the connector end facing the jack.
In one more aspect of the present invention, the snap ring includes a cap portion for fitting snugly over the jack engagement portion of the mandrel body thereby to provide initial additional strength to resist hoop stresses that may develop in the jack engagement portion before the slideable shell means is positioned toward the connector end facing the jack.
In still a further aspect of the present invention, the slideable shell is adapted to guide the snap ring into position over the coaxial cable end and adjacently against the first radial wall region of mandrel body during installation of the connector onto the prepared end of the coaxial cable.
In a somewhat different aspect of the present invention a method is provided for assembling a feedthrough coaxial cable connector from a kit of parts at an end of a coaxial cable, the method comprising the steps of:
preparing an end of the cable by peeling back a first cylindrical portion of outer insulator covering for a first length to expose an outer conductor braid/foil layer, and peeling back the outer conductor braid/foil layer and coaxially underlying dielectric insulator for a second length shorter than the first length thereby to expose a center solid conductor wire end portion,
providing a kit of parts by the steps of preforming a tubular mandrel body of conductive material dimensioned to be pressed between a dielectric core and an outer conductor of the prepared end of the cable, the mandrel body as preformed including an annular or helical knife edge surface extending from a tubular shank portion, a radial wall portion extending radially outwardly from the tubular shank portion, and a coaxial jack engagement portion extending forwardly from the radial wall portion and coaxially disposed about the exposed central conductor and dimensioned to slide onto and contact an outer surface of a jack with which the assembled connector mates in a close fitting friction engagement, and preforming a radial compression member for compressing the inside surface of the outer conductor of the coaxial cable over the knife edge of the tubular mandrel body installation,
sliding the radial compression member over the prepared cable end in one direction of movement away from the prepared end,
installing the mandrel body onto the prepared end of the cable by pushing it onto the cable end in the case of the annular knife blade or rotating it onto the cable end in the case of the helical knife blade, and
sliding the radial compression member over the prepared end of the cable installed on the mandrel body so as to compress the inside surface of the outer conductor of the coaxial cable over the knife edge of the tubular mandrel body.
The radial compression member may be preformed as a retention or snap-ring, and the kit of parts may further advantageously include an outer shell which cooperates with and co-acts with the snap-ring to position it during assembly and installation and further to compress the jack engagement portion against the jack when the assembled connector is in use in its intended manner. A "throw-away" installation tool which enables the kit of parts to be nested for delivery to the user and which facilitates ready and easy assembly and installation of the connector onto a prepared end of the coaxial cable is yet another aspect and advantage of the present invention. The tool may also provide a visual gage for installation, and it may also be adapted to self-release, once the connector elements are properly installed on the prepared cable end.
These and other objects, aspects, advantages and features will be more fully understood and appreciated upon consideration of the following detailed descripion of preferred embodiments, presented in conjunction with the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
In the Drawings:
FIG. 1 is a greatly enlarged partial view in elevation and longitudinal section along a central axis of a portion of a coaxial cable connector incorporating principles of the present invention.
FIG. 2A is a greatly enlarged diagrammatic view in elevation and longitudinal section of a portion of a resiliently elastomeric snap ring element of the FIG. 1 connector. FIG. 2B is an end view in elevation of the inside collet structure of the mandrel body of the FIG. 1 connector. FIG. 2C is a view in elevation and partial section of the mandrel body of the FIG. 1 connector modified to define an inside helical thread within the collet structure portion thereof. FIG. 2D is an end view in elevation of the inside collet structure in which the fingers thereof are formed by parallel saws. FIG. 2E is a view in elevation and partial section of the FIG. 2D mandrel body. FIG. 2F is a view in front elevation of an outer shell of the FIG. 1 connector. FIG. 2G is a view in partial section and side elevation of the FIG. 2F outer shell.
FIG. 3 is a longitudinally exploded view of the FIG. 1 connector about to be installed on a prepared cable end of a coaxial cable with the aid of one form of expendable plastic assembly tool or jig.
FIG. 4 shows the FIG. 3 assembly nested within the assembly jig incident to installation of the FIG. 1 connector onto the coaxial cable end.
FIG. 5 shows the FIG. 4 assembly with the coaxial cable installed thereon.
FIG. 6 shows the installed connector assembly with the outer shell element slid back to a position enabling the connector to be installed on a receptacle or jack.
FIG. 7 shows the installed connector assembly mounted on a receptacle or jack with the outer shell pushed forward to lock the connector in place on the receptacle.
FIG. 8A illustrates in front view and axial section a tined, resiliently elastomeric portion of a snap-ring in accordance with the principles of the present invention. FIG. 8B illustrates the FIG. 8A tined snap-ring in rear elevation.
FIG. 9 shows in exploded view an alternative embodiment of connector in accordance with the principles of the present invention.
FIG. 10 shows the FIG. 9 mandrel element positioned onto the prepared cable end.
FIG. 11 shows the completed assembly of the FIG. 9 embodiment.
FIG. 12 shows the FIG. 9 embodiment engaging a connection receptacle.
FIG. 13 illustrates yet another embodiment of the present invention in unassembled, axially exploded view.
FIG. 14 shows the FIG. 13 connector mandrel mounted on a prepared end of a coaxial cable.
FIG. 15 shows completion of assembly of the FIG. 13 connector on the prepared end of the coaxial cable in accordance with the present invention.
FIG. 16 shows the FIG. 13 connector in engagement with a connection receptacle.
FIG. 17 shows yet a further embodiment of the present invention inn unassembled, axially exploded view.
FIG. 18 shows the FIG. 17 mandrel mounted on a prepared end of a coaxial cable.
FIG. 19 shows completed assembly of the FIG. 17 mandrel on a prepared cable end and as mounted upon a mating connection receptacle.
FIG. 20 shows another embodiment of the present invention in unassembled, axially exploded view.
FIG. 21 shows partial assembly of the FIG. 20 mandrel being mounted on a prepared end of a coaxial cable.
FIG. 22 shows placement of a resiliently elastomeric band over the FIG. 20 mandrel.
FIG. 23 shows the now fully assembled FIG. 20 embodiment engaging a connection receptacle.
FIG. 24 shows yet another embodiment of the present invention in unassembled, axially exploded view.
FIG. 25 shows placement of the FIG. 24 mandrel onto the prepared end of a coaxial cable.
FIG. 26 shows placement of a snap member over the mandrel-cable assembly depicted in FIG. 25.
FIG. 27 shows the fully assembled FIG. 24 embodiment in electrical and mechanical attachment with a connection receptacle or jack.
FIG. 28 illustrates yet another embodiment of a connector assembly in accordance with the present invention in unassembled, axially exploded view in elevation and partial section.
FIG. 29 shows the FIG. 28 embodiment nested in initial, unassembled arrangement incident to installation upon a prepared coaxial cable end. An expendable insertion tool provides a nest or container for holding and aligning the uninstalled component parts of the FIG. 28 connector assembly in axial alignment to facilitate assembly onto the prepared end of the coaxial cable.
FIG. 30 illustrates installation by rotation of the FIG. 28 container and nested connector assembly elements onto the prepared coaxial cable cable end.
FIG. 31 illustrates the FIG. 28 connector assembly after the installation procedure of FIG. 30 has been completed.
FIG. 32 illustrates the assembled FIG. 28 connector assembly in electrical and mechanical connection with a receptacle or jack.
FIG. 33 shows yet another embodiment of connector assembly in accordance with the principles of the present invention. FIG. 33 is an exploded view of the connector assembly in elevation and partial section along a longitudinal explosion axis.
FIG. 34 illustrates the mounting of the mandrel portion of the FIG. 33 connector assembly onto the prepared cable end.
FIG. 35 illustrates the FIG. 33 connector assembly following placement of a resiliently elastomeric band over the FIG. 33 mandrel.
FIG. 36 illustrates the FIG. 33 connector assembly in electrical and mechanical attachment with a receptacle or jack.
FIG. 37 comprises a cable end view in elevation of an embodiment of a colleting mandrel body which is radially expansive thereby to adapt and be used with coaxial cables having insulating cores of varying diameters within a predetermined range in accordance with principles of the present invention.
FIG. 38 is a side view in elevation and section of the FIG. 37 mandrel body, taken along the line 38 in FIG. 37.
FIG. 39 is a somewhat diagrammatic view in side elevation of the FIG. 38 mandrel body and an expendable conical, ramp-shaped colleting guide member enabling installation of the FIG. 38 mandrel body onto two cables having inner cores of differing diameters.
FIG. 40 is a view in partial section and axial explosion of the FIG. 28 coaxial cable connector embodiment showing a modified container/nesting tool.
FIG. 41 illustrates placement of the coaxial cable connector elements within the container tool and threading of the assembly and tool over the prepared end of the coaxial cable.
FIG. 42 illustrates initial engagement of the dielectric core of the cable with the plug end of the container tool.
FIG. 43 illustrates the final position of the FIG. 40 assembly when the dielectric core of the cable has pushed the container tool to a point of disengagement between the teeth thereof and the slots of the mandrel cap.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
With reference to FIG. 1 a coaxial cable 10 includes a central longitudinal conductor 12 which is concentrically surrounded by a high dielectric, insulator material 14, such as plastic foam for example. A thin metal conductive foil or coating 16, typically formed of aluminum alloy, is bonded to the outer surface of and thereby contains the foam core 14 and embedded central conductor 12. An open mesh wire braid or wrap 18 is wrapped or placed immediately outside of the outer metal coating 16 to provide mechanical strength to the cable and yet, to permit the cable 10 to flex quite freely without damage. Additional layers of aluminum foil and wire braid may be included as part of a composite outer conductor. Together, these composite elements 16, 18 form an outer electrical conductor and shield which is substantially concentric with, and spaced (by the dielectric core material 14) away from the center conductor 12.
An outer insulator coating 20 of a suitable thermoplastic resin material covers the outer electrical conductor to seal the cable from the ambient, to isolate the outer conductor electrically from the ambient and to provide some additional stiffness and mechanical protection to the cable 10.
The cable 10 may be type RG-6 having a nominal overall diameter of about 0.275 inch, or a type RG-59 having a nominal overall diameter of about 0.240 inch. The diameter of the inner core material 14 of the RG-6 cable is about 0.185 inch, whereas the diameter of the inner core material 14 of the RG-59 cable is about 0.145 inch, thereby illustrating a core diameter variance range of about 0.040 inch between two very popular indoor cables.
As shown in FIG. 1, the end of the cable 10 has been prepared by cutting back the outer conductor 20, outer braid 18, outer foil jacket 16 and dielectric core 14 for a short distance to a location referred to by the lead line associated with the reference numeral 22 in FIG. 1, so as to expose a short segment of the central conductor 12. The exposed segment of the central conductor 12 is engaged by a central conductor receptacle within a conventional jack typically having a threaded outer cylindrical surface. The jack may be a standard threaded "F" port connector having a nominal outer diameter of about 0.375 inches although this diameter is known to vary somewhat in practice.
As shown in FIGS. 1 and 2A through 2G, a preferred embodiment 24 of a connector incorporating the principles of the present invention includes a mandrel body 26 formed of a suitable conductive material, such as yellow brass, for example. Preferably, the mandrel body 26 is die cast with a two-part mold that separates along the longitudinal axis of the mandrel body 26. As formed by die casting, for example, the mandrel body 26 is formed with suitable reliefs and edge contours, so that it cooperates as intended with the other structural elements of the connector without scratching or unwanted interferences. By employing a die casting operation, rather than machining, each mandrel body 26 may be formed in less than one second, leading to substantial economies in manufacturing. Preferably, the mandrel body 26 is plated with a suitable metal or alloy, such as tin, in order to improve its lubricity characteristics.
The conductive mandrel body 26 includes a thinned tubular region 28 with a slight, axially converging chamfer 29 at the end of the body 26. A frustoconical region 30 forms a frustoconical outer surface region 31. Preferably, the frustoconical outer surface region 31 forms an acute angle (less than 90 degrees) with a central longitudinal axis of the mandrel body 24 (which is generally in alignment with the central conductor 12 of the coaxial cable 10). Preferably, the angle formed by the surface region 31 with the longitudinal axis is between about 20 degrees and about 5 degrees, and it is preferably 10 degrees, plus or minus one degree.
A first, radially extending annular wall 32 extends outwardly to converge the inner end of the frustoconical surface 31 thereby to form an annular knife-edge projection or barb 33. The barb edge 33 is designed to be a cutting surface which cuts or bites slightly into an inside ring portion of the outer metal braid and foil layers 18 without actually shearing them, thereby to cut through any oxide or other insulating formations or deposits on the inside surface of the metal foil 16 so as to achieve and maintain a positive, very low resistance electrical connection between the mandrel body 26 and the outer conductor foil and braid 18. As seen in FIG. 1, the frustoconical surface 31 forms an acute angle with the annular wall 32, most preferably about 30 degrees.
A thinned tubular region 34 extends away from the base of the first radial wall portion 32 and meets a thickened second radial wall portion 36. The second wall portion 36 extends radially outwardly to the location of a collet structure 37 at which fingers or leaves 38 extend. The fingers 38 define the inside collet structure 37 and provide an inside cylindrical engagement surface suitable for engaging the outer threaded surface of a jack with which the connector 10 is intended for use, such as an "F" jack, for example. The inside surface of the collet structure 37 may be smooth, as shown in FIG. 1, or it may be provided with a shallow-cut helical groove or thread 39 as shown in FIG. 2C. A radially diverging chamfer or bevel edge 40 at the entrance of the collet structure of fingers 38 facilitates slidable engagement of the leaves or fingers 38 upon the threaded surface of the jack. The pitch of the groove 39 is set to correspond with the thread pitch of the jack. If the groove 39 is present, a more positive attachment is achieved with the threaded jack than if the thread 39 is not provided, should such a characteristic be desired.
Preferably, each finger 38 is formed with a thickened region 42 adjacent to the chamfer 40 and becomes gradually thinned at a region 44 adjacent to the second, thickened radial wall portion 36. The inside geometry of the connector 24 is generally cylindrical when in an unstressed, uncompressed state. In this relaxed state which enables the conductor 24 to be slid over the outer surface of the jack, the outer surfaces of the fingers 38 define a slightly curved or frustoconical geometry. Preferably, there are four fingers 38 provided by the mandrel body 26. There may be more or fewer fingers; however, four fingers 38, each defining a quadrant of a cylinder and separated by longitudinal slots 46 from adjacent fingers, cooperate to provide a very effective compression collet closure structure for positive engagement over the outer surface of the jack, when a hoop, band, slip ring, or other circumferentially compressing member is slidably positioned over the thickened regions 42 of the fingers 38. The fingers 38 may be formed by cross-sawing across the collet structure 37 at right angles, as shown in FIG. 2B, for example. Alternatively, and preferably for mass production, the fingers 38 are formed by a single machining operation of two parallel saws which move in one direction across the collet structure 37, as shown in FIGS. 2D and 2E.
The connector 24 further includes a resiliently deformable elastomeric cap 50 which is preferably formed by injection molding of a suitable thermoplastic resin material. The cap 50 includes a deformable flange region 52 which becomes thinned and tapered into a rearwardly flaired, knife-like annular edge 54. When the cap 50 is properly positioned over the mandrel body 26 and cable 10, a cap region 56 snugly fits over the fingers 38 and provides some additional hoop strength and protection to the fingers 38 from overbending due to proper insertion into the jack.
As shown in FIG. 2A, the cap 50 is dimensioned such that the flange region 52 snap-locks into a recess formed adjacent to the first radial wall 32 of the mandrel body 26. Since the flange region 52 is initially flaired outwardly, the thinned annular edge 54 curls up around the outer plastic insulation 20 and tends to stretch or pull it down over the knife edge 33 of the mandrel body 26. When positioned against the outer insulator 20 of the cable 10, the flaired edge 54 of the cap 50 actually presses the cable 10 against the first radial wall portion 32, causing the outer conductor braid and foil layers 18 to become sharply creased at the knife edge 33. This resultant crease not only prevents aluminum oxide from impeding a very low resistance, high conductance contact between the outer conductor and the conductive mandrel body 26, it also effectively prevents rearward displacement of the cable 10 relative to the conductor 24. In effect, tugging forces applied to the cable 10 will cause the connector to become disconnected from the jack, rather than result in separation of the cable end from the conductor, given the acute angle of the knife edge 33 of the mandrel body 26 and the compressive action of the flaired edge 54 of the elastomeric cap 50.
Preferably, an outer shell 58 is provided which further cooperates with and strengthens the connector 24. The shell is formed by injection molding of a hard plastic material, such as 6/6 nylon. As diagrammed in FIG. 1, the shell 58 has a forward cylindrical portion 60 which is dimensioned to compress the mandrel fingers 38 against the outer surface of the jack when the portion 60 is slid forward along an axial locus denoted by the arrow 61. An inside edge region 62 of the portion 60 bears against the cap region 56 which in turn presses inwardly against and compresses the fingers 38 toward the outer surface of the jack in the manner of a compression collet.
At the same time, a rear, frustoconical portion 64 of the shell 58 positions an inside surface 66 against a region of the outer plastic insulator 20 adjacent to the frustoconical surface 31 of the mandrel body 26. The inside surface 66 thereby clamps the insulator and outer conductor jacket against the surface 31, thereby preventing relative movement of the cable 10 relative to the connector 24 and particularly relative to the knife edge 33, and further accentuating the creasing action of the outer conductor jacket over the mandrel knife edge 33 and preventing rearward movement relative to the connector 24.
The outer shell 58 must have a sufficiently high modulus of elasticity and resilience to stretching so that it effectively closes the fingers 38 of the collet structure 37 as the shell 58 slides forward over the mandrel body 26. Since "F" jacks are found in practice to range in diameter over about an 0.015" range, the sizing of the inside diameter of the edge region 62 should be such that when the front edge of the outer shell portion 60 is slid about halfway over the collet structure 37, a secure grip is thereby achieved between the structure 37 and a jack of nominal diameter, e.g. 0.375 inches. In this manner, smaller and larger diameter jacks of the "F" type, for example, may be securely engaged by the connector 24, particularly if the inside surface of the collet structure 37 is provided with the shallow thread 39, as shown in FIG. 2C. A modulus of elasticity of at least 100,000 pounds per square inch, and a resiliency enabling stretching up to about four percent of nominal are presently preferred characteristics for the outer shell 58.
An oxide-formation preventing gel may be coated onto the mandrel body 26 on the radial wall portion 32 adjacent to the knife-edge 33, or on the frustoconical surface 31, or at both locations as desired. The gel may have lubricating properties and may facilitate insertion of the mandrel body 26 between the dielectric core 14 and the outer conductor foil jacket 16. Gels under compression, such as disclosed in commonly assigned U.S. Pat. Nos. 4,634,207; 4,643,924; 4,721,832; and, 4,701,574, the disclosures of which are hereby incorporated by reference, are suitable for use with the embodiments of the present invention disclosed herein.
Also, with the connector 24, a space 53 is provided between the thickened radial portion 36 of the mandrel body 26 and the flaired region 52 of the deformable elastomeric cap 58. This space 53 enables excess outer cable material to be curled up and accomodated, further relaxing the tolerance requirements for preparation of the end of the cable 10 for installation of the conductor 24.
Turning to FIGS. 3-7, an assembly sequence of a kit of parts which will eventually comprise the connector 24 is illustrated. Therein, a molded plastic assembly tool or jig 70 is shown in axial alignment with the other components previously discussed in conjunction with FIGS. 1 and 2. In FIG. 3, an end 11 of the cable 10 is prepared as shown, so that the foam core 14 and exposed outer coating 16 extend a small distance beyond the outer insulator 20, and braid and aluminum foil layers 18. The braid and foil layers 18 are folded up and radially outwardly away from the longitudinal axis of the cable 10. The cable end 11 may be prepared with a special tool, or simply by using a sharp knife or single edge razor blade. The stubby wires of the braid and foil layers 18 are folded back by the installer's finger after the ring of outer insulator coating has been cut away.
In FIG. 4, the mandrel body 26, cap 50 and outer shell 58 are nested into the assembly tool 70 in preparation for receiving the prepared cable end 11 as shown therein. A annular ring portion 71 of the tool 70 provides a convenient grip location for the user's fingers. The cable is gripped in one hand, and the assembly tool 70 containing the body 26, cap 50 and outer shell 58 is gripped in the other hand. Then, the cable is pushed toward the tool 70 and into and through the the outer shell and cap 50. When the cable engages the mandrel body 26, it pushes the body forward and away from the cap 50 and outer shell 58, as shown in FIG. 5.
In FIG. 5, the cable end 11 is shown inserted into the tool 70 and the end has pushed the mandrel body 26 to the forward end of the tool 70, passing over and leaving behind the cap 50 and the shell 58. If the tool 70 is formed of a transparent plastic material, then it is possible for the installer to see that the cable end 11 has passed over the frustoconical region 30 and the thinned tubular region 34 and is butted up against the outside of the second radial wall portion 36. In this manner the transparent tool 70 acts as a gage for aiding proper installation. When the cable has reached the desired position, as shown in FIG. 5, the cable 10 is then pulled away from the tool 70, with the installer grasping the outer shell 58.
As the cable 10 and mandrel body 26 are drawn rearwardly, the outer shell 58 retains the cap 50 and causes it to slip over the cable 10 and over the annular bulge therein now formed by the outer jacket elements lying upon the surface 31. Continuing to pull the cable 10 relative to the shell 58 causes the cap 50 to be moved into its final locking position over the thinned tubular region 34 in front of the first wall portion 33, as shown in FIG. 1. The cap 50 is thus snap-locked against the outer insulator 20 at the vicinity of the radial wall 32 and prevents rearward movement of the cable 10 by coaction with the knife edge barb 33 of the mandrel body 26.
It will be appreciated that the tool or jig 70 forms a convenient package for containing a kit of parts including the mandrel body 26, snap-lock cap 50 and outer shell 58. A "blister-pack" package may include the tool and parts and be formed onto a cardboard substrate for convenient distribution to the householder or other installer/user of the connector 24. The substrate may conveniently provide printed instructions and illustrations for assembly and use of the connector 24.
In FIG. 6, the connector assembly 24 has been withdrawn from the tool 70 (which may now be discarded as spent, or retained for installation of another connector assembly 24). Then, with the outer shell in the slid back position as shown in FIG. 6, the connector 24 may be pushed onto a jack 72, as shown in FIG. 7. The exemplary jack 72, typically an "F" jack, may define an outer threaded surface against which the fingers 38 of the mandrel body 26 come into contact. The shallow thread 39 (if present on the inside surface of the collet structure 37) is pitched to mate with the threaded surface of the jack. The outer shell 58 is then slid forward to a position shown in FIG. 7 which simultaneously locks the fingers 38 against the threaded surface 74 and the outer jacket elements against the frustoconical surface 31 of the mandrel body 26. The connector 24 is now securely, yet removably, attached to the connector. Any tugging on the cable 10 will result in the connector 24 becoming dislodged from the jack 72 in preference to an unwanted separation of the connector 24 and the prepared cable end 11.
To remove the connector 24 from the jack 72, the outer shell 58 may be grasped between the fingers and rotated to facilitate loostening the connector from the jack. The shell 58 is then slid rearwardly, thereby releasing the fingers 38 and enabling ready removal of the connector assembly 24. An outer annular ring or a pair of opposed flanges 59 (FIGS. 2F and 2G) formed on the shell 58 provides a suitable thumb-finger gripping mechanism to enable rotatable and slideable movement of the shell 58 relative to the mandrel 26, cap 50 and cable 10 for installation and removal of the connector 24 to and from the jack 72.
FIG. 8 shows a cap 50a which is provided with a plurality of splines 55 in lieu of the continuous resilient portion 54. The operation of the cap 50a is similar with that described for the cap 50. However, the splines 55 dig into the outer plastic insulation 20 of the cable 10 to create a series of stress points or barbs which coact securely to retain and lock the braid and foil layers 18 against the knife-edge barb 33. In practice, the pointed tips of the splines 55 actually dig into the outer plastic coating 20.
FIGS. 9-12 illustrate an alternative embodiment 24a of a connector embodying the principles of the present invention. In these figure, the same reference numerals are applied to the elements discussed in conjunction with FIGS. 1-7. A modified cap 50b includes a thickened radial portion 52a leading to the deformable annular edge 54. A disk 58a provides the finger closure function provided by the region 60 of the shell 58, previously described. The advantage of this embodiment 24a is that it provides a very flat and compact connector assembly. Also, there is very little drawback from stress relaxation of the thick disk, a problem sometimes encountered with the thinner outer shell 48 of the earlier described embodiments. One disadvantage with the connector 24a is that without the portion 64 of the outer shell, there is no additional reinforcement or support provided to the cable end at the vicinity of the frustoconical portion 30 of the mandrel body 26.
FIGS. 13-16 illustrate yet another embodiment 24b of connector embodiment the principles of the present invention. In this embodiment 24b, the outer shell 58 has been replaced by a split ring 58b which is nested in a suitable band retention structure 39 formed around the periphery of the fingers 38 of the mandrel shell 26a. The cap is formed as a disk 50c which includes the elastomeric edge 54. An outer portion of the disk 50c enables the fingers to grasp the connector 24b for installation and removal from the jack 72. Because of the thickness of the disk 50c, there is very little stress relaxation, and once installed on the cable end over the mandrel body, the dick 50c will securely lock the cable end to the mandrel body 26. This embodiment 24b also has the drawback of not providing any structure for retaining the cable at the frustoconical portion of the mandrel body as is provided by the outer shell 58. Also, the split-ring 58b does not provide as secure an engagement with the jack as is achieved with the inside compression collet structure 37.
FIGS. 17-19 illustrate a connector 24c also embodying the principles of the present invention. In this embodiment, only two elements are present, a slightly modified mandrel body 26b, and an elongated elastomeric threaded cap 50c. The fingers 38 of the mandrel body 26b are thickened for greater hoop strength. The threaded cap 50c is fit over the cable 10. The cable end 11 is then installed on the mandrel body 26b, and the cap 50c is then threaded onto the mandrel-cable arrangement as shown in FIG. 19, thereby securing the cable end 11 to the mandrel body 26b.
FIGS. 20-23 illustrate yet another embodiment 24d embodying the principles of the present invention. In this three-part embodiment 24d, the cap 50 is replaced by a cylinder 50d of elastomeric material. The cylinder 50d and an outer shell 58b are positioned onto the cable 10, and it is then forced onto the mandrel body 26 as with the connector 24. The shell 58b is then used to push the elastomeric cylinder 50d into a position overlying the knife edge 33 of the mandrel body 26, as shown in FIG. 22. Then, the connector 24d may be installed on the jack 72 and the shell 58b slid forward to lock the fingers 38 onto the outer threaded surface 74 of the jack, as shown in FIG. 23.
The connector 24e shown in FIGS. 24-27 reveals yet another combination of cap 50e and outer shell 58c for use with the originally described mandrel body 26. In this embodiment of connector 24e, the cap 50e includes an elongated tail section 53 which is dimensioned and configured to overly the knife edge 33 of the mandrel body 26. When assembled and installed on the jack 72, the outer shell 58 is pushed to its forward position by grasping the outer flange 59. This action locks the fingers 38 onto the threaded outer surface 74 of the jack 72. A tapered annular edge 63 cooperates with the cap 50e to provide further compression to the cable jacket at the vicinity of the knife edge 33, as shown in FIG. 27.
The connector 24f, shown in FIGS. 28-32, includes a mandrel body 26c in which the frustoconical knife-blade edge 33 of the prior embodiments is replaced by a knife-blade helical thread or edge 33a projecting radially outwardly from the thinned tubular region 28. In one practical example, the thinned tubular region may be slightly frustoconical and have an average outside diameter of about 0.180 inch. The helical knife blade edge 33a has an apex which is approximately 0.210 inch and is formed as an acutely angled projection extending from the tubular region 28. The helical knife blade 33a is so shaped as to bite sufficiently into the fine aluminum strands of the outer conductor braid or aluminum foil to obtain a positive electrical contact with the foil and also to provide a positive mechanical securement therewith, without causing the strands to shear or break off.
An effective compromise between sharpness and dullness of the knife edge is to make it flat across for about two to three mils. A one mill flat is too sharp and will result in shearing the fine wire braid, while an eight mil radius at the edge has been found to be too dull with resultant slippage of the braid under tension. Ideally, the knife blade 33a should subject the braid wires to shear stresses without actually resulting in shearing them off. In practice the compromise is reached by considering sharpness of the knife edge 33a and the hardness of the material of which it is made.
The jig or tool 70a is modified to include teeth 80 which are sized and positioned to engage the slots 82 defined between the fingers 38 of the collet structure 37. An outer end portion 84 of the tool 70 may be provided with radial spokes or projections to facilitate gripping and impartation of rotational torque to the tool 70 to enable insertion of the threading mandrel 26c onto the prepared end of the cable 10. Rotational installation of the mandrel 26c onto the prepared cable end is illustrated diagrammatically in FIG. 30 by the arrow 84. The use of a helical knife-blade edge 33a on the mandrel 26c has been found to be particularly advantageous in order to facilitate ready installation of the assembly 24f onto the coaxial cable 10 at low ambient temperatures which cause substantial stiffness of the outer elastomer jacket 20 thereof. When the outer jacket 20 has stiffened due to lower ambient temperatures, it aids in causing the helical knife-blade edge 33a to bite into and positively engage the outer conductor braid/foil of the coaxial cable 10. Otherwise, the assembly of the connector assembly 24f is the same as described hereinabove for the assembly 24.
The connector 24g, shown in FIGS. 3-36, combines the FIG. 28 helically threaded mandrel body 26c with the elastomeric cylinder 50d used in the FIG. 20 connector embodiment 24d. The mandrel 26c is threaded onto the prepared cable end as explained above in connection with the connector body 24f of FIG. 28, whereas, the elastomeric cylinder 50d is positioned as explained in conjunction with the FIG. 20 embodiment above.
The mandrel body 26d, illustrated in FIGS. 37-39, solves a problem otherwise associated with coaxial cables having different diameter foam cores within a predetermined size range. For example, an RG-59 cable 10a may have a diameter of about 0.145 inch for the core 16a, whereas an RG-6 cable 10b may have a diameter of about 0.185 for its core 16b. Both cables may be effectively terminated by a connector assembly including the mandrel body 26d. The body 26d, otherwise identical to the body 26, is formed to define e.g. four longitudinal slots 86. The slots 86 are very narrow, e.g. 0.10 inch, for example; and they extend from the cable end to the wall 36. An inside diameter, denoted by reference numeral 88, at the cable end corresponds generally to the outside diameter of the smallest cable core 16a within the size range to be accomodated, while an inside diameter, denoted by reference numeral 90, of the central bore of the tubular portion 34 of the mandrel body 26d is sized to accomodate the outside diameter of the largest cable core 16b within the predetermined size range. The frustoconical portion 30a of the mandrel body 26d is tapered toward the cable end diameter 88 on both the inside and outside thereof.
An expendable ramping tool 92 is provided for use in attaching the mandrel body 26d to the prepared cable end. The ramping tool 92, when positioned axially over the exposed central conductor 12 of the cable 10 to abut the core 16 causes the fingers formed by the slots 86 to expand radially as the mandrel body 26d is pushed toward the core 16. This radial expansion of the cable end of the mandrel body 26d positions it so that it will properly come into overlying engagement with the cable core, whether it be of a smaller diameter such as the core 16a, or of a larger diameter such as the core 16b. After the outside of the core 16 is engaged, the ramping tool is forced axially all the way through the tubular portion and into the region enclosed by the collet structure 37 where it may be readily removed and discarded by the installer.
While the frustoconical knife-blade edge 33 is illustrated in the FIG. 37-39 embodiment, it is clear that a helical knife blade edge 33a may also be used with equally successful results in this embodiment.
Referring now to FIGS. 40-43, the connector 24f depicted in FIGS. 28-32 and discussed in conjunction with those figures is again depicted. However, in FIGS. 40-43, a modified tool 70b illustrated in combination with the elements of the connector 24f and the cable 10. The tool 70b has a significant advantage in that it automatically prevents over-installation of the connector mandrel 26c into the prepared cable end.
In certain locations, low light levels make it most difficult or even impossible to gage whether the connector mandrel body 26c has been rotated onto the prepared cable end sufficiently. The consequence in practice has been that the mandrel body 26c has been threaded onto the cable end too far, with the result that the outer conductor braid and shield has become bunched up, leading to poor electrical and mechanical connection of the connector onto the cable end. The tool 70b is configured to prevent the mandrel body 26c from being rotated too far onto the prepared cable end.
In accordance with an aspect of the present invention, the tool 70 is formed with a hollow cylindrical plug region 83. The plug region 83 is concentric with the connector elements and with the prepared cable end. The plug region 83 defines an inner wall 85 which butts up against the mandrel body, as shown in FIG. 41. A central opening 87 is defined through the inner wall 85. Since the center conductor wire 12 has a diameter which typically ranges between 32 mils and 40 mils, the central opening 87 is sized to be about twice the largest wire diameter, or about 80 mils in diameter. This diameter is selected for two very important reasons: first, it is sufficiently smaller than the diameter of the dielectric core 16 of the cable 10 so that an end wall 17 thereof will come into contact with the inner wall 85 and thereafter dislodge the tool 70b. Secondly, the small diameter opening 87 serves as a gage to be sure that the center conductor 12 which is exposed at the prepared cable end is not bent. (If the exposed end of the inner conductor 12 is bent, damage will likely ensure to the center contact within a receptacle with which the assembled conductor and cable end will be used).
As shown in FIG. 41 the cable 10 is just entering engagement with the mandrel body 26c. As the tool 70b is rotated, the teeth 80 thereof engage the slots 82 between the leaves 38 of the outer cap portion 37 of the mandrel body 26c and cause it to rotate with the rotation of the tool 70b. FIG. 42 illustrates a position at which the mandrel body 26c has been screwed onto the prepared end of the cable 10 to a position at which the end wall 17 of the dielectric has butted up against the inner wall 85 of the tool.
As shown in FIG. 43, continued rotation of the tool 70b causes the mandrel body 26c to move rearwardly along the prepared cable end, and results in the dielectric core 26 projecting slightly beyond the end of the inner wall of the mandrel body. At this position, the inner wall 85 of the tool 70b is pushed away from the mandrel, causing the teeth 80 of the tool to become disengaged with the slots 82 between the cap fingers 38. At the point shown in FIG. 43, further rotation of the tool 70b does not cause any further rotation of the mandrel body 26c and thereby prevents it from becoming installed too far along the prepared cable end. Thus, with the tool 790b, the installer may rotate it relative to the cable 10 until automatic disengagement occurs, at which point the mandrel body 26c is properly installed to a correct length along the prepared cable end. While the same concept may be employed with a push-on tool 70 and annular barb 33, discussed previously, it is particularly advantageous to use the concept with the mandrel 26c having the helical thread barb 33a.
Statement of Industrial Applicability
The present invention realizes a three-part feedthrough connector assembly for a coaxial cable which may be readily installed upon a prepared end of a coaxial cable, and which efficiently and effectively clamps onto the prepared cable end to provide a secure electrical and mechanical securement to the outer conductor. A locking mechanism for locking the connector onto a jack or receptacle, and an installation tool, provide important aspects of the present invention.
While the instant invention has been described by reference to what is presently considered to be the most practical of embodiment and the best mode of practice thereof, it is to be understood that the invention may embody other widely varying forms without departing from he spirit of the invention. For example, the outwardly diverging shape of the inside compression collet 37 may be curved as opposed to frustoconical thereby to enable overstroke to account for the range in diametral tolerances of various jacks within a type with which the connector may be used. Also, alternatively, the outwardly divergent shape may be provided by the cap member 50. The presently preferred embodiments are presented herein by way of illustration only and should not be construed as limiting the present invention, the scope of which is more particularly set forth in the following claims.
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A feedthrough coaxial cable connector includes a tubular mandrel body dimensioned to be pressed between a foil-bonded dielectric core and other elements of an outer conductor of the prepared end of the cable. The body has cable engagement surface which defines a knife edge projection therearound for engaging an outer conductor of the cable by creating shear stresses therein without actually shearing the outer conductor. A tubular shank portion extends from the cable engagement surface portion to a radial wall portion, and a jack engagement portion is coaxial about the exposed central conductor. The jack engagement portion achieves a tight friction fit upon a jack and may be formed as an inside compression collet. A radial copmression providing structure causes an inside surface region of the outer conductor to bear directly against and bend over the knife edge portion. Preferably, a slideable shell is slideably positionable generally away from a connector end facing the outer surface of the jack to enable the jack engagement portion of the connector to slide over the outer surface of the jack, and slideably positionable toward the connector end so as to radially compress the radially diverging jack engagement portion against the outer surface of the jack to secure the connector thereto. A kit of parts including an expendable installation tool enables proper asembly of the cable connector without special skills or tools.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a thread cutting device for a cylinder bed forming seams machine for sewing by means of a plurality of needles on the pieces of fabric supported on a cylindrical bed while transporting the fabric pieces in a given direction.
Thread cutting devices of the type must have a thread cutter, and a thread catch member for catching needle thread loops formed in numbers corresponding to the number of needles and looper threads interlooped with the needle thread loops for directing them to the cutter. In cylinder bed sewing machines, however, the internal space of the bed is very limited and various components such as a looper and the like have to be housed in a limited internal space. For this reason, special consideration has been given with respect to the mounting position for the thread cutting device and the path of movement thereof.
A prior-art thread cutting device disclosed in U.S. Pat. No. 4,098,209 is shown in FIG. 10. In the FIG. 10 thread cutting device, a thread catch member 50 having dogleg-shaped slots 51, 51 is connected to a driving lever 52 so that when the lever 52 is pivotally moved from its position shown in the direction of arrow A, the thread catch member 50 is caused to move lower-leftwardly in FIG. 10 by the action of guide pins 53, 53 fitted in the slots 51, 51, being then allowed to move linearly in the leftward direction. A support member 55 having a slot 54 is urged leftward by a resilient member means 56, so that when the thread catch member 50 is moved lower-leftwardly, the support member 55 is actuated by the thread catch member 50 to move in the lower-leftward direction until it goes into abutment with a stopper 57. When the thread catch member 50 is in linear movement as aforesaid, the support member 55 is on standby as it is in abutment with the stopper 57, so that as the thread catch member 50 turns back with needle thread and looper thread (not shown) caught thereinto, the caught-up threads are cut by a thread cutter 58 provided at the front end of the support member 55.
As FIG. 12 illustrates, a straight line path X 1 along which the thread catch member 50 is linearly moved is in orthogonal relation to the direction Y of fabric feed during sewing operation, and the starting point S of a path X 2 which the thread catch member 50 follows when it is in lower-leftward movement is located away from an extension of the straight line path X 1 so that the catch member 50 may not interfere with the movement of a looper 59 shown in FIG. 11.
The looper 59, as shown in FIG. 11, is caused to move toward and away from the straight line path X 1 (see FIG. 12), along which the thread catch member 50 moves, while being inclined at an angle of θ relative to the path X 1 , and accordingly, when the movement of the looper 59 is stopped at a left dead point, the needle thread loops 60 are inclined at a specified angle relative to the direction Y of fabric movement.
Such a thread cutting device involves a problem that since it is simply of such arrangement that the thread catch member 50 is caused to move back and forth along the aforesaid straight line path X 1 , the catch member 50 may sometimes fail to catch some needle thread loop or loops 60 when it turns back on the straight line path X 1 , thus causing a loop catching error.
SUMMARY OF THE INVENTION
Accordingly, the aforsaid problem is solved by providing a thread cutting device which includes a cutter, a thread catch member having hook portions, and a support member pivotally and slidably supported on a machine bed and with which the thread catch member is slidably engageable only in a direction toward needle and looper thread loops. Unlike the well known arrangement such that the hook portion of the thread catch member which is caused to project into needle thread loops is movable back and forth in orthogonal relation to the direction of fabric feed, the present invention provides a thread cutting device in which the thread catch member is movable toward and away from needle thread and looper thread loops only after both the support member and the thread catch member are displaced with a pivot link connected to the support member so as to assure a specified tilted pose. While the support member is held in a specified tilted pose, the hook portions of the thread catch member move in linear fashion from a position at which they overlap the cutter to a projected position at which the hook portions seize the needle thread loops and looper thread loop. In this connection, the straight line path along which the hook portions travel is inclined at an angle of θ 1 relative to the direction orthogonal to the direction of fabric feed during sewing operation. This angle of inclination θ 1 is generally identical with the inclination angle θ 2 at which the looper is inclined relative to aforesaid straight line path X 1 . The thread catch member is moved in reverse, so that after the hook portion seize the needle thread and the looper thread loops they are cut by a trimming action of the hook portion and the cutter. Thereafter both the thread catch member and the support member remove into a standby position.
It is an object of the invention to provide a thread cutting device which is caused to project into and retreat from a plurality of needle thread loops in a more conveniently orthogonal relation to the plane of opening of the needle thread loops.
It is another object of the invention to provide means for assuring seizement of a plurality of needle thread loops as well as looper thread loop to ensure trimming of all the thread loops carried from the looper.
The above and further objects and novel features of the invention will more fully appear from the following detailed description when the same is read in connection with the accompanying drawing. It is to be expressly understood, however, that the drawing is for purpose of illustration only and is not intended as a definition of the limits of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 to 3, inclusive, are plan views, partially cutaway, showing a thread cutting device representing one embodiment of the invention;
FIG. 4 is an enlarged plan view showing key portions of the device seen in FIG. 3;
FIG. 5 is a partially cutaway side view corresponding to FIG. 4;
FIG. 6 is an enlarged section taken along line VI--VI in FIG. 1;
FIG. 7 is an enlarged section taken along line VII--VII in FIG. 1;
FIG. 8 is a fragmentary schematic view in plan illustrating the function of the thread cutting device;
FIG. 9 is an explanatory view illustrating the path to be followed by hook portions of a thread catch member;
FIG. 10 is a partially cutaway plan view showing a conventional thread cutting device;
FIG. 11 is a fragmentary schematic view in plan illustrating the function of the conventional thread cutting device; and
FIG. 12 is an explanatory view illustrating the path to be followed by hook portions of a thread catch member in the conventional thread cutting device.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
One embodiment of the thread cutting device according to the invention will now be described as to the arrangement and functions thereof, with reference to FIGS. 1 to 9, inclusive, of the accompanying drawings.
In FIGS. 1 through 3, numeral 1 designates a support member having a thread cutter 2 at the front end thereof and provided with a slot 3 at a suitable spot therein. In the slot 3 there is fitted a guide pin 4 consisting of a machine screw and the like, which is fixed to a machine bed. The rear end of the support member 1 is pivotably connected by a pin 6 to a free end 5a of a pivot link 5. Accordingly, the support member 1 is pivotally movable on the guide pin 4 between a standby position shown in FIG. 1 and an operative position shown in FIGS. 2 and 3 as it is guided by the pivot link 5. A support pin 7 by which the other end of the pivot link 5 is pivotally supported is secured to a mounting member 9 located on the bed 8 as shown in detail in FIG. 6. Numeral 10 designates a stopper member fixed to the mounting member 9, which engages the support member 1 to prevent it from moving toward needle and looper threads when the support member 1 is in the operative position as may be seen from FIGS. 2 and 3. Shown by 11, 12 are resilient means, each consisting of a springy material. The one resilient means 11 constantly urges the support member 1 to slide toward needle and looper thread loops, while the other resilient means 12 constantly exerts pressure on the pivot link 5 to urge its free end to turn toward the needle and looper thread loops.
Numeral 13 designates a thread catch member having hook portions 14, 15 at two front end locations therein and held in engagement with guide members 16, 16, fixed to the support member 1, so that it is slidable only toward needle thread loop 60 and looper thread loops 61 (FIGS. 4 and 5). As FIG. 7 illustrates, the thread catch member 13 is slidable held between the each guide members 16 each and the mounting member 9. An engagement portion 17 of the thread catch member 13 is opposed to a stepped portion 18 of the support member 1. Accordingly, when the support member 1 under the force of the resilient means 11, 12 is pivotally moved between the standby position and the operative position, the stepped portion 18 is pressed against the engagement portion 17, so that the support member 1 is moved to follow the thread catch member 13.
Numeral 30 designates drive means for driving the thread catch member 13. The drive means include a drive lever 19 which is connected at its front end 19a to the thread catch member 13 through engagement of a front end 19a with a recess 20 formed in the catch member 13. The base end 19b of the drive lever 19 is connected through a connecting member 22 to a drive power source including a solenoid 21 or the like. Numeral 31 designates a slide piece mounted to the thread catch member 13 at a median portion thereof, which is adapted to be stopped by a guide piece 32 mounted to the machine bed when the thread catch member 13 is displaced to the operative position shown in FIG. 2 while being held in the specified tilted pose. When the thread catch member 13 alone is caused to move back and forth as FIG. 3 illustrates, the slide piece 31 goes in slide contact with the guide piece 32 to allow a smooth and accurate linear movement of the thread catch member 13 in the specified tilted pose.
Thus, when the drive power source 21 of the drive means 30 is actuated, the support member 1 strikes the stopper member 10 so that it is displaced to the operative position while being caused to assume the specified tilted pose as FIG. 2 shows; and then the lever 19 is pivotally moved in a forward direction shown by the arrow M, whereupon the thread catch member 13 is guided by the guide members 16, 16 into slide movement in conjunction with the guide piece 31 guided by the guide piece 32, so that the hook portions 14, 15 of the thread catch member 13 move in linear fashion from a position at which they overlap the cutter 2 to a projected position shown in FIG. 3. When the lever 19 is pivotally moved away from the FIG. 3 position thereof and in the reverse direction indicated by the arrow N, the thread catch member 13 is actuated to slide so that the hook portions 14, 15 are moved in reverse.
In this connection it is noted that as FIGS. 8 and 9 illustrate, the straight line path Z 1 along which the hook portions 14, 15 travel is inclined at an angle of θ relative to the direction orthogonal to the direction Y of fabric feed during sewing operation. This angle of inclination θ, as above mentioned, is generally identical with the inclination angle θ at which the looper 23 is inclined relative to the aforesaid straight line path X 1 , which angle is set at approximately 3 degrees.
FIG. 4 is a plan view showing the thread catch member 13 as it appears when it plunges into a plurality of needle loops 60 and a looper loop 61 caught in the needle loops 60. FIG. 5 is a partially cutaway side view thereof. As can be clearly seen from these figures, when the thread catch member 13 moves to the projected position, the one hook portion 14 thereof plunges into the looper loop 61 and the other hook portion 15 plunges into the needle loops 60. As the thread catch member 13 slides back from the projected position so that the hook portions 14, 15 thereof reverses the straight line path Z 1 shown in FIG. 9, the hook portion 14 carries along the looper thread 61 caught thereinto and similarly the hook portion 15 carries along the needle threads 60 caught thereinto. Thus, the needle threads 60 are cut by the thread cutter 2, and then the looper thread 61 is cut likewise. As explained earlier with reference to FIG. 8, the straight line path Z 1 is inclined at an angle of θ relative to the direction orthogonal to the direction Y of fabric feed, and therefore the needle threads 60 . . . are caught into the hook portion 15 accurately and without any catching error. The cut end of the looper thread 61 continued from the thread supply is held in position between a fitting strip 25 shown in FIGS. 4, 5 and the thread catch member 13.
In a cylinder-type multi-needle sewing machine wherein a plurality of needle thread loops 60 are formed, as in the present instance, the needle loops 60 are slightly distorted in relation to the direction Y of thread feed as may be seen from FIGS. 4, 5 and 8, and the plane of opening of the individual needle loops (i.e., a plane defined by each needle loop) is slightly inclined relative to the direction Y of fabric feed. Therefore, by displacing the thread catch member 13, together with the support member 1, into the tilted pose by means of the pivot link, then causing the catch member 13 to move back and forth along the straight line path Z 1 , the hook portions 14, 15 are caused to plunge into corresponding thread loops from a more orthogonal direction relative to aforesaid plane of opening, which fact assures more accurate plunging as compared with the case shown in FIG. 11 in which the hook portions plunge into the loops in oblique relation to the plane of opening. Furthermore, even if the needle thread loops 60 are somewhat irregularly distorted, the hook portions 14, 15 can be caused to plunge accurately into the loops 60 and to accurately catch the loops 60 as they reverse their path. Thus, erroneous catching possibilities may be effectively prevented.
When the support member 1 is pivotally moved by the lever 19 from the standby position to the operative position and vice versa, the thread catch member 13 is pivotally moved integrally with the support member 1. In this case, the path which the hook portions 14, 15 pass through is an arcuate path shown by Z 2 in FIG. 9. Therefore, when the support member 1 is in the standby position, both the thread catch member 13 and the support member 1 are positioned outside the path of movement of the looper 23 shown in FIGS. 4, 5 and 8, and thus they do not interfere with the movement of the looper 23.
In the above described embodiment, the support member 1 and the pivot link 12 are constantly urged by the biasing means 11 and 12 respectively so that the pivot link 12 is pivotally moved toward needle and looper thread loops and so that the support member 1 is caused to slide in the same direction. The invention is not limited to such arrangement. Depending upon the urging force of such biasing means, use of either one of the biasing means 11, 12 may achieve similar purposes.
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A thread cutting device for a cylinder bed sewing machine for sewing by means of a plurality of needles a piece of fabric supported on a cylindrical bed while transporting the fabric piece in a given direction, wherein a hook portion of a thread catch member which is adapted to plunge into and retreat from needle thread loops in orthogonal relation to an obliquely inclined plane of opening of the needle thread loops so that a plurality of needle and looper threads are accurately caught into the hook portion and then carried along thereby for cutting. In addition, an arrangement is disclosed which enables the mounting of the thread cutting device without interferring with the movement of a looper, even if the available space within the bed is very limited.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application claims benefit of priority from U.S. Provisional Application No. 60/376,991, filed on Apr. 30, 2002.
FIELD OF THE INVENTION
The invention relates to a process for preparing highly functionalized γ-butyrolactams and γ-amino acids by reductive amination of mucohalic acid or its derivatives, and discloses a process for preparing pregabalin, a GABA analog with desirable medicinal activity.
BACKGROUND OF THE INVENTION
Pregabalin (S-3-Aminomethyl-5-methyl-hexanoic acid) is a 3-substituted γ-amino butyric acid (GABA) analog that exhibits an array of useful medicinal properties, as disclosed in WO 93/23383, as well as U.S. Pat. No. 6,306,910 and WO U.S. Pat. No. 00/76958, the latter two of which are assigned to the same assignee as the instant application.
Synthetic approaches to pregabalin, its racemate and related analogues such as 3-aminomethyl-5-methyl-octanoic acid, which has the structure
generally commence from a linear precursor. For instance, WO 93/23383 discloses a route commencing from 5-methyl-hexanoic acid that requires 8 transformations. A recently disclosed alternative strategy commences with the enantioselective conjugate addition of S-α methylbenzyl amine to 2-Methylene-succinic acid dimethyl ester (Michael J. Mayer, Trip Report, Synthetic Pathways 9 th Symposium on the Latest Trends in Organic Synthesis , Albany Molecular Sciences Technical Report Vol. 5, No. 19 (2001), p. 9; also available at http://www.albmolecular.com. logical. net/features/tekreps/vol05 no19/ last visited Feb. 6, 2003). The reaction provides a mixture of diastereomers, which can be separated, and the requisite diastereomer is then converted to pregabalin via 6 additional steps.
A shortcoming of either of these approaches, particularly in scale-up and production contexts, is that they require a multitude of steps and purification operations. As a result, there is a need for a process for synthesizing pregabalin and other 3-substituted γ amino acids that minimizes the total number of synthetic transformations and simplifies purification steps.
SUMMARY OF THE INVENTION
These and other needs are met by the present invention which provides a process for preparing a compound of formula I
wherein: R 1 is H, (C 1 -C 8 )alkyl, (C 3 -C 7 )cycloalkyl, aryl, (CH 2 ) n -aryl, heterocyclo, (CH 2 ) n -heterocyclo, heteroaryl, or (CH 2 ) n -heteroaryl, wherein n is 0, 1, 2, or 3; and
R 2 and R 2′ are each independently H, straight or branched (C 1 -C 6 )alkyl, a straight or branched (C 2 -C 7 )alkenyl, (C 3 -C 7 )cycloalkyl, alkylcycloalkyl, alkylalkoxy, alkylphenyl, alkyphenoxy, phenyl or substituted phenyl;
comprising:
(a) treating mucochloric or mucobromic acid 1 wherein X is Cl or Br with R′OH, wherein R′ is (C 1 -C 6 )alkyl, —CH 2 -phenyl, or —CH 2 -substituted phenyl, in the presence of acid to provide 2
(b) conjugate addition of R 2 R 2′ CHM 0 wherein R 2 and R 2′ are as defined above and wherein M 0 is MgBr, CuBr, or B(OH) 2 , to 2, to provide 3A
(c) hydrogenation of 3A to provide 4A
and (d) reductive amination of 4A under hydrogenation conditions using ammonium formate or R 1 NH 2 , wherein R 1 is (C 1 -C 8 )alkyl, (C 3 -C 7 ) cycloalkyl, aryl, (CH 2 ) n -aryl, heterocyclo, (CH 2 ) n -heterocyclo, heteroaryl, or (CH 2 ) n -heteroaryl, wherein n is 0, 1, 2, or 3, followed by hydrolysis
What is also provided is a process for preparing 3-Aminomethyl-5-methyl-hexanoic acid
comprising:
(a) treating mucochloric or mucobromic acid 1 wherein X is Cl or Br with R′OH, wherein R′ is (C 1 -C 6 )alkyl or—CH 2 -aryl, in the presence of acid, to provide 2
(b) conjugate addition of
wherein M 1 is MgBr, CuBr, or
wherein M 2 is B(OH) 2 , to 2 to provide 3B, wherein “- - -” is absent or is a bond;
(c) hydrogenation of 3B to provide 4B
(d) reductive amination of 4B using ammonium formate, followed by hydrolysis
What is also provided is a process for preparing 3-aminomethyl-5-methyl-octanoic acid
comprising:
(a) treating mucochloric or mucobromic acid 1 wherein X is Cl or Br with R′OH, wherein R′ is (C 1 -C 6 )alkyl or —CH 2 -aryl, in the presence of acid, to provide 2
(b) conjugate addition of
wherein M 1 is MgBr, CuBr, or
wherein M 2 is B(OH) 2 , to 2 to provide 3BB, wherein “- - -” is absent or is a bond;
(c) hydrogenation of 3BB to provide 4BB
and (d) reductive amination of 4B using ammonium formate, followed by hydrolysis
What is also provided is a process for preparing a compound of formula I
wherein: R 1 is H, (C 1 -C 8 )alkyl, (C 3 -C 7 )cycloalkyl, aryl, (CH 2 ) n -aryl, heterocyclo, (CH 2 ) n -heterocyclo, heteroaryl, or (CH 2 ) n -heteroaryl, wherein n is 0, 1, 2, or 3; and
R 2 and R 2 are each independently H, straight or branched (C 1 -C 6 )alkyl, a straight or branched (C 2 -C 7 )alkenyl, (C 3 -C 7 )cycloalkyl, alkylcycloalkyl, alkylalkoxy, alkylphenyl, alkyphenoxy, phenyl or substituted phenyl;
comprising:
(a) reductive amination of mucochloric or mucobromic acid 1 wherein X is Cl or Br, using a reducing agent in the presence of ammonium formate or R 1 NH 2 , wherein R 1 is (C 1 -C 8 )alkyl, (C 3 -C 7 )cycloalkyl, aryl, (CH 2 ) n -aryl, heterocyclo, (CH 2 ) n -heterocyclo, heteroaryl, or (CH 2 ) n -heteroaryl, wherein n is 0, 1, 2, or 3, and an acid catralyst, to provide 2C
(b) conjugate addition of R 2 R 2′ CHM 0 , wherein M 0 is MgBr, CuBr, or B(OH) 2 , to 2C to provide 3C
(c) hydrogenation of 3C to provide 4C
and (d) hydrolysis of 4C
What is also provided is a process for preparing 3-Aminomethyl-5-methyl-hexanoic acid
comprising:
(a) reductive amination of mucochloric or mucobromic acid 1 wherein X is Cl or Br using a reducing agent in the presence of benzylamine or 1-phenyl-ethylamine to provide 2D
(b) conjugate addition of
wherein M 1 is MgBr, CuBr, or
wherein M 2 is B(OH) 2 , to 2D to provide 3D, wherein “- - -” is absent or is a bond;
(c) hydrogenation of 3D to provide 4D
and (d) hydrolysis of 4D
What is also provided is a process for preparing 3-aminomethyl-5-methyl-octanoic acid
comprising:
(a) reductive amination of mucochloric or mucobromic acid 1 wherein X is Cl or Br using a reducing agent in the presence of benzylamine or 1-phenyl-ethylamine to provide 2D
(b) conjugate addition of
wherein M 1 is MgBr, CuBr, or
wherein M 2 is B(OH) 2 , to 2D to provide 3DD, wherein “- - -” is absent or is a bond;
(c) hydrogenation of 3DD to provide 4DD
and (d) hydrolysis of 4DD
What is also provided is a process for reductively aminating mucohalic acid, comprising:
(a) contacting mucochloric or mucobromic acid I wherein X is Cl or Br with a reducing agent, an acid catalyst, and R 3 NH 2 , wherein R 3 is H, (C 1 -C 8 )alkyl, (C 3 -C 7 )cycloalkyl, aryl, (CH 2 ) n -aryl, heterocyclo, (CH 2 ) n -heterocyclo, heteroaryl, or (CH 2 ) n -heteroaryl, wherein n is 0, 1, 2, or 3; to provide 2E
DETAILED DESCRIPTION OF THE INVENTION
The invention processes for preparing 3-substituted γ amino butyric acids disclosed herein possess a number of advantages. Firstly, they give rise to 3-substituted γ-amino butyric acids such as pregabalin, its racemate, or its analogues such as 3-aminomethyl-5-methyl-octanoic acid in a minimum number of steps and under mild conditions. Secondly, they make use of generally inexpensive and readily available reagents. Thirdly, they exploit the synthetic potential of mucohalic acid.
Mucochloric acid 1 (2,3-dichloro-4-oxo-2-butenoic acid) and mucobromic acid (2,3-dibromo4-oxo-2-butenoic acid) are commercially available and inexpensive starting materials. Both molecules are characterized by the presence of a carbon-carbon double bond with Z configuration, two halogen atoms, and two carbonyl groups. This high degree of functionality makes both mucochloric and mucobromic acid particularly useful building blocks for the synthesis of a variety of biologically active heterocycles, such as substituted 1,5-dihydropyrrol-2-ones, pyrrolidines, and γ-lactams, and γ-amino acids such as pregabalin.
Mucobromic and mucochloric acid surprisingly have not been commonly employed in organic synthesis as C-4 building blocks. Presumably, this is because of the many reactive sites in the molecules, their poor stability under basic conditions, and the perception among those of ordinary skill in the art of the difficulties associated with the selective manipulation of the halogen atoms in the presence of the other functional groups.
In spite of these perceived difficulties, mucohalic acid is the keystone of the invention processes disclosed herein. As summarized in Scheme 1, the processes differ in the relative sequence of the reaction steps, but both rely on the use of mucohalic acid as a synthetic platform for the elaboration of the 3-substituted γ amino butyric acid framework. Thus, in Route A, protection of mucohalic acid in Step A provides the hemiacetal 2A. In Step B, Conjugate addition of R 2 R 2 ′M to 2A, followed by elimination of halide, provides conjugate addition product 3A. Hydrogenation of 3A in Step C to provide 4A, followed by reductive amination of 4C in Step D provides lactam 5A, which may undergo hydrolysis in situ or in a separate step to provide 3-substituted γ amino butyric acid I. In contrast, in Route A′, reductive amination is the first step in the synthetic sequence (Step A′), followed by conjugate addition (Step B′), hydrogenation (Step C′), and hydrolysis (Step D′).
Pregabalin, its opposite enantiomer, or its racemate, is readily prepared by either of these routes. As depicted in Scheme 2, Route A, mucohalic acid is first converted to the O-benzyl acetal 2B. Organocuprate additon provides the conjugate addition product 3B. Hydrogenation and dehalogenation gives rise to 4B. Reductive amination under hydrogenation conditions gives rise to lactam 5B, which may be hydrolyzed under basic conditions to provide pregabalin or any of its analogues including 3-Aminomethyl-5-methyl-octanoic acid. Alternatively, as depicted in Route A′ of Scheme 2, reductive amination of mucohalic acid in the first step using benzyl amine or 1-phenylethyl amine provides 2D. Conjugate addition, hydrogenation, and hydrolysis as described for Route A, provides the target compound.
This same methodology can be exploited to prepare the pregabalin analogue 3-aminomethyl-5-methyl-octanoic acid. All the steps are identical to the above, except that Step B or Step B′ would require the use of
or the like as described herein for the 1,4 conjugate addition/halide elimination reaction.
1. Definitions
The following definitions are used, unless otherwise described: halo is fluoro, chloro, bromo, or iodo. Alkyl, alkoxy, alkenyl, alkynyl, etc. denote both straight and branched groups; but reference to an individual radical such as “propyl” embraces only the straight chain radical, a branched chain isomer such as “isopropyl” being specifically referred to.
Thus the term “alkyl” means a straight or branched hydrocarbon radical having from 1 to 8 carbon atoms and includes, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, and the like.
The term “alkenyl” means a straight or branched hydrocarbon radical having from 2 to 7 carbon atoms and includes, for instance, vinyl, allyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, 2-methyl-2-propenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, 3-methyl-2-butenyl, 3-methyl-3-butenyl, 1-hexenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl, 5-hexenyl, 4-methyl-3-pentenyl, 1-heptenyl, 2-heptenyl, 3-heptenyl, 2-methyl-1-hexenyl, 2-methyl-2-hexenyl, 3-methyl-2-hexenyl, 3-methyl-3-hexenyl, 3-methyl-1-hexenyl, 4-methyl-1-hexenyl, 5-methyl-1-hexenyl;
The term “cycloalkyl” means a hydrocarbon ring containing from 3 to 7 carbon atoms, for example, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cycloctyl, decalinyl, norpinanyl, and adamantyl. Where possible, the cycloalkyl group may contain double bonds, for example, 3-cyclohexen-1-y1. The cycloalkyl ring may be unsubstituted or substituted by one or more substituents selected from alkyl, alkoxy, thioalkoxy, hydroxy, thiol, nitro, halogen, amino, alkyl and dialkylamino, formyl, carboxyl, —CN, —NH—CO—R, —CO—NHR, —CO 2 R, —COR, wherein R is alkyl, cycloalkyl, heterocycloalkyl, aryl, or heteroaryl, wherein alkyl, aryl, and heteroaryl are as defined herein.
The term “aryl” means a cyclic or polycyclic aromatic ring having from 5 to 12 carbon atoms, and being unsubstituted or substituted with one or more of the substituent groups recited above for alkyl, alkenyl, and alkynyl groups. Examples of aryl groups include phenyl, 2,6-dichlorophenyl, 3-methoxyphenyl, naphthyl, 4-thionaphthyl, tetralinyl, anthracinyl, phenanthrenyl, benzonaphthenyl, fluorenyl, 2-acetamidofluoren-9-yl, and 4′-bromobiphenyl.
The term “alkoxy” means a straight or branched hydrocarbon radical which has from 1 to 8 carbon atoms and is attached to oxygen. Alkoxy includes, for example, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy, isobutoxy, tert-butoxu, n-pentoxy, n-hexoxy, n-heptoxy, and the like.
The term “alkylcycloalkyl” means a straight or branched hydrocarbon radical having from 1 to 8 carbon atoms as defined above attached to cycloalkyl group as defined above.
The term “alkylalkoxy”, means a straight or branched hydrocarbon radical having from 1 to 8 carbon atoms as defined above attached to an alkoxy group as defined above.
The term “alkylphenyl” means a straight or branched hydrocarbon radical having from 1 to 8 carbon atoms as defined above attached to a phenyl or substituted phenyl group.
The term “alkyphenoxy” means a straight or branched hydrocarbon radical having from 1 to 8 carbon atoms as defined above attached to a phenoxy or substituted group.
The compounds prepared by the invention process may have one or more chiral centers and may exist in and be used or isolated in optically active and racemic forms. It is to be understood that the processes of the present invention can give rise to any racemic or optically-active forms, or mixtures thereof. It is to be further understood the products of the invention process can be isolated as racemic, enantiomeric, or diastereomeric forms, or mixtures thereof. Purification and characterization procedures for such products are known to those of ordinary skill in the art, and include recrystallization techniques, as well as chiral chromatographic separation procedures as well as other methods.
2. 3-Substituted γ Amino Butyric Acid Synthesis Via 5Alkoxy-3,4-dihalo-5H-furan-2-ones (Route A)
In Scheme 1, Step A of Route A, mucobromic or mucochloric acid is converted to the corresponding 5-alkoxy-3,4-dihalo-5H-furan-2-one 2A upon treatment with a C 1 -C 6 alcohol or benzyl or substituted benzyl alcohol in the presence of acid. In a typical procedure, a toluene solution of I equivalent of mucohalic acid is combined with 1.5 equivalents of benzyl alcohol and 0.05 equivalent of p-toluene sulfonic acid. The mixture is then heated at reflux for 8 to 24 hours. The product furanone is typically obtained in high yield (85-90 percent).
In Step B of Route A, conjugate addition of an organocuprate reagent R 2 R 2′ CM to 2A, followed by halide elimination, provides the substituted furanone 3A. In a typical procedure, the organocuprate is generated in situ in the presence of N-methypyrrolidinone (NMP) from a commercially available Grignard reagent (e.g., an alkyl- aryl-, or alkylmagnesium bromide) and copper iodide. If the requisite Grignard reagent is not commercially available, it can be readily prepared from the corresponding organohalide compound using one of the many methods available to the skilled artisan. The furanone is then added to the organocuprate reagent over 5 to 10 minutes at −10 to 0° C., and the resulting mixture is allowed to warm to room temperature.
In Step C of Route A, hydrogenation of alkylfuranone 3A according to a method readily available to the skilled artisan provides dihydrofuranone 4A. In a typical procedure, the furanone is dissolved in THF, and combined with a tertiary amine base such as triethyl amine, and Pd/C. This mixture is hydrogenated in a high-pressure reactor until hydrogen uptake ceases.
In Step D of Route A, reductive amination of dihydrofuranone 4A with ammonium formate or R 1 NH 2 gives rise to lactam 5A, which may be hydrolyzed in situ or isolated and converted to the 3-substituted γ amino butyric acid I in a separate step. In a typical procedure, dihydrofuranone 4A is combined in methanol with ammonium formate, triethyl amine, and Pd/C. This mixture is hydrogenated in a high pressure reactor until hydrogen uptake ceases to give rise to a mixture of the lactoam 5A and the desired ring-opened material I. Submission of the mixture to hydrolysis conditions known to the skilled artisan (for example, treatment with aqueous base), as depicted in Step E, gives rise to I.
Route A is readily adapted to the synthesis of pregabalin or 3-aminomethyl-5-methyl-octanoic acid. For pregabalin, step A remains the same. Step B requires the use of sec-butyl magnesium bromide to generate the necessary organocuprate. Alternatively, the sidechain can be attached in a Suzuki-type coupling procedure using
and a palladium catalyst. Steps C, D, and E remain the same. Similarly, as indicated earlier,
or the like as described herein, may be used to provide the precursor to 3-aminomethyl-5-methyl-octanoic acid. 3. 3-Substituted γ Amino Butyric Acid Synthesis Via 3,4-Dihalo-1-Substitued-1,5-dihydro-pyrrol-2-ones (Route A′)
The first step in Route A′ of Scheme I for the synthesis of 3-substituted γ amino butyric acid requires reductive amination of mucohalic acid to provide compound 2C.
A. Route A′/Step A: Reductive Amination of Mucohalic Acid
As indicated previously, mucobromic and mucochloric acid are not popular C-4 building blocks because of the many reactive sites in the molecules, their poor stability under basic conditions, and the perception among those of ordinary skill in the art of the difficulties associated with the selective manipulation of the halogen atoms in the presence of the other functionality. As an example, although it is known that in the presence of acetic acid, mucobromic or mucochloric acid may react with hydrazine or arylhydrazines to form pyridazinones (Scheme 3), the reaction conditions are severe: acetic acid as the solvent, a pH of 1 to 2, and temperatures between 60 and 120 ° C.
Other than this reported transformation, however, a manifold for the selective manipulation of the functional groups present in mucohalic acid is unknown.
i. Reagents
The reductive amination process described herein accommodates a wide variety of reagents and conditions.
Mucohalic Acid: To begin, either mucobromic or mucochloric acid are suitable for use in the reductive amination process.
Amine: Also, a wide variety of amines may be used in the reductive amination process, and are represented by the formula R 1 NH 2 , wherein R 1 is selected from hydrogen or C 1 -C 7 alkyl or substituted C 1 -C 7 alkyl, C 3 -C 12 cycloalkyl or substituted C 3 -C 12 cycloalkyl, C 3 -C 12 heterocycloalkyl or substituted C 3 -C 12 heterocycloalkyl, aryl or substituted aryl, or heteroaryl or substituted heteroaryl.
The primary or secondary alkyl, cycloalkyl, heterocycloalkyl, aryl, or heteroaryl amine used in the invention can be substituted with one or more groups selected from halo, hydroxy, C 1 -C 6 alkoxy, carboxy, C 1 -C 6 alkoxycarbonyl, aminocarbonyl, halomethyl, dihalomethyl, trihalomethyl, haloethyl, dihaloethyl, trihaloethyl, tetrahaloethyl, pentahaloethyl, thiol, (C 1 -C 4 )alkylsulfanyl, (C 1 -C 4 ) alkylsulfinyl, and aminosulfonyl, Examples of substituted alkyl groups include fluoromethyl, difluoromethyl, trifluoromethyl, tribromomethyl, hydroxymethyl, 3-methoxypropyl, 3-carboxypentyl, 3,5-dibromo-6-aminocarbonyldecyl, and 4-ethylsulfinyloctyl. Examples of substituted alkenyl groups include 2-bromoethenyl, 1-amino-2-propen-1-yl, 3-hydroxypent-2-en-1-yl, 4-methoxycarbonyl-hex-2-en-1-yl, and 2-nitro-3-bromo4-iodo-oct-5-en-1-yl. Typical substituted alkynyl groups include 2-hydroxyethynyl, 3-dimethylamino-hex-5-yn-1-yl, and 2-cyano-hept-3-yn-1-yl.
The amine used in the reductive amination process may be an amino acid or its corresponding ester. Typical amino acids include L-lysine, L-alanine, L-arginine, L-aspartic acid, N-alpha-benzyloxycarbonyl-L-arginine, L-citrulline, gamma-L-glutamic acid, L-glycine, L-histidine, L-hydroxproline, L-isoleucine, L-leucine, L-lysine, L-methionine, L-ornithine, L-phenylalanine, L-proline, L-pyroglutamic acid, L-serine, L-tryptophan, L-tyrosine, L-valine. The amine may also be a carboxy terminal-linked peptide having 1 to 10 amino acids or an addition salt thereof. Such peptides may include L-arginyl-L-arginine, N-benzyloxycarbonyl-glycyl-L-proline, L-glutaryl-glycyl-arginine, glycyl-glycine, glycyl-L-phenylalanine, glycyl-L-proline, and L-seryl-L-tyrosine, as well as others.
The amine used in the reductive amination process of the present invention may have one or more chiral centers and may exist in and be used or isolated in optically active and racemic forms. It is to be understood that the process of the present invention can employ any racemic, optically-active, polymorphic, geometric, or stereoisomeric form, or mixtures thereof, of an amine. It is to be further understood the products of the reductive amination process can be isolated as racemic, optically-active, polymorphic, geometric, or stereoisomeric forms, or mixtures thereof. Purification and characterization procedures for such products are known to those of ordinary skill in the art, and include recrystallization techniques, as well as chiral chromatographic separation procedures as well as other methods.
However, typically, benzyl amine or S-1-phenyl-ethyl amine is used.
Reducing Agent: A number of reducing agents can be used in the reductive amination process of the present invention. These reducing agents include sodium triacetoxy borohydride, sodium cyanoborohydride, triethyl silane, Ti(OiPr) 4 /NaBH 3 CN, borohydride exchange resin, Zn/acetic acid, sodium borohydride/magnesium perchlorate, or zinc borohydride/zinc chloride. Preferably, the reducing agent is sodium triacetoxyborohydride.
Acid Catalyst: A variety of acid catalysts can be used in the reductive amination process of the present invention. The acid may be a Bronsted, or protic, acid, or a Lewis, or non-protic, acid. Examples of protic acids suitable for use in the reductive amination process of the present invention include acetic acid, trichloroacetic acid, trifluoroacetic acid, or formic acid. Examples of non-protic acids suitable for use in the reductive amination process of the instant application include magnesium chloride, magnesium triflate, boron trifluoride etherate, AlCl 3 , FeCl 3 , ZnCl 2 , AlBr 3 , ZnBr 2 , TiCl 4 , SiCl 4 and SnCl 4 .
ii. Procedure and Stoichiometry
In the reductive amination process of the present invention, the mucohalic acid is contacted with the amine, reducing agent, and acid catalyst. “Contacted” means that the reaction components are typically mixed in a liquid to form a homogeneous or heterogeneous mixture. The liquid employed in the reductive amination process of the present invention is selected from a polar aprotic solvent. Preferably, the polar aprotic solvent is selected from tetrahydrofuran, acetonitrile, nitromethane, chloroform, methylene chloride, monochloro ethane, 1,1, or 1,2 dichloroethane, 1,1,1 or 1,1,2 tricholoroethane, or 1,1,1,2, or 1,1,2,2 tetrachloroethane. More preferred solvents include methylene chloride or chloroform. Mixtures of solvents can also be used.
The molar equivalents of each of the reaction components (i.e., mucohalic acid, amine, reducing agent, and acid catalyst) used in the reductive amination process of the instant application are:
(a) 1 equivalent of mucohalic acid; (b) 1 to 5 equivalents of amine; (c) 1 to 10 equivalents of reducing agent; and (d) sufficient acid catalyst to maintain a pH of about 2 to about 7.
More preferably, the molar equivalents of each of the reaction components (i.e., mucohalic acid, amine, reducing agent, and acid catalyst) used in the reductive amination process if the instant application are:
(a) 1 equivalent of mucohalic acid; (b) 1 to 3 equivalents of amine; (c) 1 to 5 equivalents of reducing agent; and (d) sufficient acid catalyst to maintain a pH of about 3 to about 6.
Most preferably, the molar equivalents of each of the reaction components (i.e., mucohalic acid, amine, reducing agent, and acid catalyst) used in the reductive amination process if the instant application are:
(a) 1 equivalent of mucohalic acid; (b) 1 to 2 equivalents of amine; (c) 1 to 3 equivalents of reducing agent; and (d) sufficient acid catalyst to maintain a pH of about 4 to about 5.
In the reductive amination process of the present invention, the initial concentration of mucohalic acid in the polar aprotic solvent is typically 0.1 to 0.5 M. More preferably, it is 0.15 to 0.45 M. Most preferably, it is 0.2 to 0.3 M.
In the reductive amination process of the present invention, the temperature is typically from about −25° C. to about 50° C., with lower temperatures being more suitable for mucobromic acid and higher temperatures being more suitable for mucochloric acid. When mucochloric acid is used, the temperature is more preferably from about about 0° C. to about 40° C., and most preferably from about 10° C. to about 30° C.
In the reductive amination process of the present invention, reaction times are typically from about 30 minutes to about 5 days; more preferably, from about 1 hour to 3 days; and most preferably, from about 6 hours to 48 hours.
To demonstrate the present invention process, the reactions of mucobromic or mucochloric acid with aniline or benzylamine in acetic acid were investigated (Table 4). A mixture of dichloromethane and acetic acid (1:1 v/v) was chosen as the solvent to maintain the stability and solubility of both starting materials. Sodium triacetoxyborohydride was used as the reducing agent and the reactions were conducted at room temperature. Initially γ-lactam 7 was isolated in 46% yield, but a solvent screen illustrated that 7 could be obtained in 65 to 75% yield once the amount of acetic acid was reduced.
TABLE 4
Reductive amination in different solvents. a
entry
Solvent
Yield (%)
1
CH 2 Cl 2 :HOAc
46
(1:1)
2
1,4-dioxane
48
3
THF
52
4
CH 3 CN
49
5
DCE
68
6
CHCl 3
66
7
CH 3 NO 2
35
8
CHCl 3
76
a Reaction conditions for entries 1, 2 and 6: 1 equiv of mucochloric acid, 1.1 equiv. of “aniline”, 1.5 equiv of NaBH(OAc) 3 , CHCl 3 (cat. HOAc), under N 2 for 24 h. Reaction conditions for entries 3-5, 7-8: 1 equiv of mucochloric acid, 1.0 equiv. of “aniline”, 3.0 equiv of NaBH(OAc) 3 , CH 2 Cl 2 :HOAc (5:3 v/v), under N 2 for 24 h. The reaction time was not optimized. Products were isolated and
# purified by silica gel chromatography and/or crystallization. Products are estimated to be >95% pure by 1 H NMR and elemental analysis. All compounds gave satisfactory elemental analysis data.
The invention process has been further extended to anilines, with electron-donating, electron-withdrawing and neutral substituents, as well as an heteroaromatic amine system (table 5). Electron-deficient anilines (entries 3, 4 and 9) and electron-rich anilines (entries 2, 5 and 7) reacted with almost equal facility and the heteroaromatic amine (entry 6) also underwent selective reaction with reasonable yield
TABLE 5
Reductive amination with different “anilines”. a
En-
Yield
Yield
try
“Aniline”
Product
(%)
Entry
“Aniline”
Product
(%)
1
50
5
40
2
55
6
55
3
65
7
60
4
42
8
68
5
40
9
75
6
55
10
20
a Reaction conditions for entries 1, 2 and 6: 1 equiv mucochloric acid, 1.1 equiv. of “aniline”, 1.5 equiv of NaBH(OAc) 3 , CHCl 3 (cat. HOAc), under N 2 for 24 h. Reaction conditions for entries 3-5, 7-10: 1 equiv of mucochloric acid, 1.0 equiv of “aniline”, 3.0 equiv NaBH(OAc) 3 , CH 2 Cl 2 :HOAc (5:3 v/v), under N 2 for 24 h. The reaction time was not optimized. Products were isolated and purified by
# silica gel chromatography and/or crystallization. Products are estimated to be >95% pure by 1 H NMR and elemental analysis. All compounds gave satisfactory elemental analysis data.
Mucochloric acid (1) can exist as the open or cyclic form (Scheme 6). However, the ultraviolet spectrum in CHCl 3 indicates 1 exists predominantly in the lactone form. Additional spectral data, i.e. vibrational (IR, Raman) and others (NMR and NQR) suggest that the lactone is the dominant form in both the liquid and solid states. Experimental results further support these observations.
The proposed mechanism for the reductive amination process is depicted in Scheme 7. Thus, protonation of the aldehyde pushes the equilibrium in favor of the open-form aldehyde. Reductive amination of the aldehyde moiety, followed by ring closure and loss of water, provides the cyclic lactam.
In accordance with this proposed mechanism, reductive amination with dialkyl amines and N-alkyl anilines provided substituted αβ-unsaturated γ-amino acids. All the attempts were successful and all products were isolated in acceptable yield. (Table 8).
TABLE 8
Reductive amination with different amines. a
En-
yield
try
amine
product
(%)
1
67
2
20
3
48
4
89
5 b
50/82
6
80
7
85
a Reaction conditions: 1 equiv of mucochloric acid, 1.1 equiv. of amine, 1.5 equiv of NaBH(OAc) 3 , CHCl 3 (cat. HOAc), under N 2 for 24 h. The reaction time was not optimized. Products were isolated and purified by silica gel chromatography and/or crystallization. Products are estimated to be >95% pure by 1 H NMR and elemental analysis. All compounds gave satisfactory elemental analysis data.
b This reaction provides a effective method of obtaining substituted γ-butyrolactones.
Interestingly, attempted reductive aminations with ammonium formate provided not the expected lactam 8, but instead, lactone 9, in 50% yield. When the reaction was repeated without adding ammonium formate, the yield of 9 increased to 82%. Also, when ammonium acetate was used, the reaction gave lactone 9 in 80% yield.
In summary, Step A′ of Scheme 1, Route A′ represents a simple, efficient and selective method to prepare N-benzyl-3,4-dichloro-1,5-dihydropyrrol-2-one, N-aryl (or alkyl)-3,4-dichloro-1,5-dihydropyrrol-2-ones and substituted γ-amino acids. These products possess a geometrically defined tetrasubstituted olefin, two differentiated vinyl halides and an acidic sight, and could be used in the synthesis of a variety of compounds.
B. Route A′/Steps B, C, and D
Steps B, C, and D of Route A′ are as provided for Steps B, C, and E of Route A.
The following examples are intended to illustrate various embodiments of the invention and are not intended to restrict the scope thereof.
EXAMPLES
Route A Scheme 2
Step A: 5-Benzyloxy-3,4-dihalo-5H-furan-2-one.
Mucohalic acid (0.4-0.6 mol, I equivalent), benzyl alcohol (1.5 equivalents), and para-toluenesulfonic acid (0.05 equivalent) were combined in 1000 mL toluene and in an apparatus equipped with a Dean Stark Strap. The mixture was heated at reflux until water collection in the Dean Stark Trap had ceased. The mixture was then cooled to room temperature. The toluene was removed in vacuo at 35-40° C. to leave the crude product as a very pale amber oil. The crude material was purified by column chromatography on silica gel eluting with 55, then 10% ethyl acetate in heptane.
1. 5-Benzyloxy-3,4-dichloro5H-furan-2-one. Prepared as provided in Procedure A. 95% yield. 1 H NMR (CDCl 3 , 300 MHz) δ 7.41 (br, s, 5H), 5.87 (s, 1H), 4.94 (d, 1H), 4.79 (d, 1H). Elemental Analysis Observed(Theoretical) for C 10 H 8 Cl 2 O 3 : C, 51.12(50.99); H, 2.92(3.11); N, <0.05(0.00); Cl, 27.19 (27.37).
2. 5-Benzyloxy-3,4-dibromo-5H-furan-2-one. Prepared as provided in Procedure A. 100% yield. 1 H NMR (CDCl 3 , 300 MHz) δ 7.41 (br, s, 5H), 5.87 (s, 1H), 4.92 (d, 1H), 4.78 (d, 1H). Elemental Analysis Observed(Theoretical) for C 10 H 8 Br 2 O 3 : C, 38.62(37.97); H, 2.30(2.32); N, <0.05(0.00); Br, 44.71 (45.92).
Step B: 5-Benzyloxy-3-halo4-isopropyl-5H-furan-2-one.
Alternative 1: Via Cuprate Addition
5-Benzyloxy-3,4-dihalo-5H-furan-2-one (0.03-0.15 mol, 1 equivalent), 1-methyl- 2-2 pyrrolidinone (NMP) (excess), and copper iodide (1 equivalent) were combined and stirred at room temperature under an inert atmosphere. After about 30 minutes, the resulting tan suspension was cooled to about —15 to about −20° C., and isobutylmagnesium bromide (1.5 equivalents) was added dropwise as a 2.0 M solution in diethyl ether. The reaction mixture was then quenched with a saturated solution of aqueous ammonium chloride, and extracted with methyl tertbutyl ether to provide the crude product as an amber oil. Purification by column chromatography on silica gel eluting with 10% ethyl acetate in heptane provided the product as a colorless oil.
1. 5-Benzyloxy-3chloro4-isopropyl-5H-furan-2-one. 70% yield. MS (AP+) 281.0.
2. 5-Benzyloxy-3-bromo4-isopropyl-5H-furan-2-one. 70% yield. MS (AP+) 325.0.
Alternative 2: Via Suzuki Coupling
5-Benzyloxy-3,4-dihalo-5H-furan-2-one (1 equivalent), 2-methyl-1-propenyl boronic acid (2 equivalents), cesium fluoride (2.5 equivalents, PdCl 2 (PPh 3 ) 2 (0.05 equivalent), and triethylbenzyl ammonium chloride (0.05 equivalent) were combined. To this mixture was added a nitrogen-purged toluene and water solvent mixture. The reaction mixture was stirred at room temperature over night and then quenched with 2N aqueous HCl and extracted with 100 mL toluene. The extract was concentrated in vacuo to provide the crude product as a pale orange oil which was purified by column chromatography on silica gel eluting with 10% ethyl acetate in heptane.
2. 5-Benzyloxy-3-bromo4-isopropyl-5H-furan-2-one. 30% yield. MS (AP+) 325.0.
Step C: 5-Benzyloxy-4-isopropyl-dihydro-furan-2one
A mixture of 5-Benzyloxy-3-halo4-isopropyl-5H-furan-2-one (5 mmol, 1 equivalent) and triethyl amine (1.2 equivalents) was dissolved in 65 mL THF. Was transferred to a high pressure reactor. Pd/C (0.3 g) was added, and the mixture was hydrogenated with stirring under 40 pounds per square inch (psi) of hydrogen. The mixture was hydrogenated until hydrogen uptake ceased (about 3 hours). The Pd/C catalyst was filtered out and the solvent was removed in vacuo. The residue was diluted with ethyl acetate, washed with saturated aqueous ammonium chloride and dried over magnesium sulfate. The extract was concentrated in vacuo to give the product as a colorless oil. 1. From 5-Benzyloxy-3-chloro-4-isopropyl-5H-furan-2-one. 38% yield. MS (AP+) 249.1.
2. From 5-Benzyloxy-3-bromo4-isopropyl-5H-furan-2-one. 83% yield. MS (AP+) 249.1
Steps D/E: 3-Aminomethyl-5-methyl-hexanoic acid 5-Benzyloxy-4-isopropyl-dihydro-furan-2-one was hydrogenated in a high pressure reactor as provided above in Step C. Thus, 1.3 g of 5-benzyloxy-4-isopropyl-dihydro-furan-2-one was combined with 1.7 g of ammonium formate, 0.3 g of 20% Pd/C, 1.7 g of ammonium formate and 0.07 g of [Ir(COD)Cl] 2 in 25 mL of methanol. The mixture was hydrogenated at 70° C. and 20 pounds per square inch of pressure until hydrogen uptake ceased (about 7 hours) to provide a mixture of 3-Aminomethyl-5-methyl-hexanoic acid (M+160.1) contaminated with 4-isopropyl-pyrrolidin-2-one (M+142.1).
The mixture may be submitted to base hydrolysis to provide exclusively 3-Aminomethyl-5-methyl-hexanoic acid.
Route A′, Scheme 1
Step A′. Reductive Amination of Mucohalic Acid with Benzylamine.
Sodium triacetoxyborohydride (6.4 g, 3.0 equivalents) was added slowly to a mixture of mucohalic acid (1 equivalent), acetic acid (0.2 mL) and benzyl amine (1.1 equivalent) in chloroform (50 mL). The reaction mixture was stirred at approximately 25° C. for 24 hours. The reaction mixture was then quenched with water (200 mL) and washed with water (100 mL). The organic layer was dried over magnesium sulfate and concentrated in vacuo to give 1.28g of the product which was further purified by silica gel column chromatograpy to provide the lactam (1.59 g, 66% yield.).
Reductive Amination of Mucochloric Acid with (R)-1-phenylethylamine.
Following the procedure as provided above, provided an 89% yield of the product lactam after purification.
All patents, and patent documents are incorporated by reference herein, as though individually incorporated by reference. The invention has been described with reference to various specific and preferred embodiments and techniques. However, it should be understood that many variations and modifications may be made while remaining within the spirit and scope of the invention.
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The invention relates to a process for preparing highly functionalized γ-butyrolactams and γ-amino acids by reductive amination of mucohalic acid or its derivatives, and discloses a process for preparing pregabalin, a GABA analog with desirable medicinal activity.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of Korean Patent Application No. 10-2004-0061508, filed Aug. 4, 2004, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a multi air conditioning system and a method for operating the same, and more particularly to a multi air conditioning system, which adjusts opening degrees of indoor units in a stopped state to control the optimum amount of refrigerant flowing into indoor units in an operating state, and a method for operating the multi air conditioning system.
[0004] 2. Description of the Related Art
[0005] Generally, a multi air conditioning system comprises one outdoor unit, a plurality of indoor units connected to the outdoor unit, and electric valves for adjusting the amount of refrigerant entering into the indoor units.
[0006] The above conventional multi air conditioning system operates compressors in a cooling mode or a heating mode, and adjusts opening degrees of the electric valves installed in the indoor units, thus controlling the amount of refrigerant entering into the indoor units. In case that predetermined temperatures of the indoor units differ from each other, the indoor units are operated at different operating capacities so as to optimally condition air in indoor spaces, in which the indoor units are installed.
[0007] Further, when some indoor units of the plural indoor units are stopped, the opening degrees of the electric valves installed in the indoor units in a stopped state are maintained to predetermined values, and the opening degrees of the electric valves installed in the indoor units in an operating state are changed to proper values according to the operating conditions of the multi air conditioning system. Korean Patent Laid-open No. 2003-0073358 discloses the conventional multi air conditioning system in detail, and is incorporated herein by reference.
[0008] When only some of the plural indoor units are operated, the above-described conventional multi air conditioning system maintains the electric valves of those indoor units in the stopped state to have constant opening degrees regardless of the operating conditions of the overall system. Thus, the conventional multi air conditioning system is disadvantageous in that the overall system efficiency is decreased when the amount of the refrigerant flowing into the indoor units in the operating state is not proper.
[0009] That is, when the opening degrees of the electric valves of the indoor units in the stopped state are excessively high, a large amount of the refrigerant flows into the stopped indoor units whereas a small amount of the refrigerant flows into the indoor units in the operating state, thereby reducing the heating and cooling efficiency of the system.
[0010] On the other hand, when the opening degrees of the electric valves of the stopped indoor units are excessively low, the refrigerant scarcely flows into those stopped indoor units, and part of the refrigerant is trapped in heat exchangers of the stopped indoor units (particularly, in the heating mode), thereby reducing the amount of the refrigerant circulating into the refrigerant route and thus reducing the heating and cooling efficiency of the system.
SUMMARY OF THE INVENTION
[0011] Therefore, an object of the invention is to provide a multi air conditioning system for adjusting the amount of refrigerant flowing into indoor units in a stopped state, to improve the overall system efficiency, and a method for operating the multi air conditioning system.
[0012] In accordance with one exemplary embodiment, a method is provided for operating a multi air conditioning system having a plurality of indoor units, comprising: determining whether or not some indoor units are in a stopped state; measuring temperatures of heat exchangers of those indoor units in the stopped state; and changing opening degrees of valves installed in the stopped indoor units to change the amount of refrigerant flowing into the stopped indoor units if the temperatures of the heat exchangers of the stopped indoor units deviate from a reference range.
[0013] In accordance with another exemplary embodiment, a method is provided for operating a multi air conditioning system having a plurality of indoor units, comprising: determining, in a heating mode of the system, whether or not some indoor units are in a stopped state; measuring temperatures of pipes connected to heat exchangers of the indoor units in the stopped state; and increasing opening degrees of valves for adjusting the amount of refrigerant flowing into the stopped indoor units if the temperatures of the pipes connected to the heat exchangers of the stopped indoor units are lower than a first reference temperature, and decreasing the opening degrees of the valves, in case that the temperatures of the pipes are higher than a second reference temperature
[0014] In accordance with yet another object, a multi air conditioning system is provided having a plurality of indoor units, comprising: a plurality of valves for adjusting the amount of refrigerant flowing into the indoor units; a plurality of pipe temperature sensors for measuring temperatures of pipes connected to heat exchangers of the indoor units; and a controller for changing opening degrees of valves installed in the stopped indoor units if the temperatures of the pipes measured by the pipe temperature sensors of the stopped indoor units deviate from a reference range.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] These and/or other aspects and advantages of the invention will become apparent and more readily appreciated from the following description of the exemplary embodiments, taken in conjunction with the accompanying drawings in which:
[0016] FIG. 1 is a schematic view illustrating a route of a refrigerant of a multi air conditioning system in accordance with one exemplary embodiment of the present invention;
[0017] FIG. 2 is a block diagram of the multi air conditioning system shown in FIG. 1 ; and
[0018] FIG. 3 is a flow chart illustrating a method for operating the multi air conditioning system shown in FIGS. 1 and 2 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] Reference will now be made in detail to the exemplary embodiment of the present invention, an example of which is illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. The embodiment is described below by referring to the figures.
[0020] As shown in FIGS. 1 and 2 , a multi air conditioning system in accordance with one exemplary embodiment comprises an outdoor unit 10 , and first and second indoor units 20 and 30 connected to the outdoor unit 10 .
[0021] The outdoor unit 10 includes a compressor 11 for compressing a refrigerant, a four-way valve 12 for adjusting the flow direction of the refrigerant discharged from the compressor 11 , an outdoor heat exchanger 13 for receiving the refrigerant compressed by the compressor 11 and exchanging heat between the refrigerant and external air, an outdoor fan 14 for forcibly blowing air to the outdoor heat exchanger 13 , and an outdoor fan motor 15 for rotating the outdoor fan 14 .
[0022] The outdoor unit 10 further includes an outdoor electric valve 16 for expanding the refrigerant, an accumulator 17 for transmitting the refrigerant in a gaseous state to the compressor 11 , and an outdoor unit microcomputer 18 ( FIG. 2 ) for controlling the components of the outdoor unit 10 and communicating data with indoor unit microcomputers 26 and 36 .
[0023] The first and second indoor units 20 and 30 respectively include first and second indoor heat exchangers 21 and 31 for receiving internal air and exchanging heat with the internal air, first and second indoor fans 22 and 32 for inhaling the internal air from the outside of the indoor units 20 and 30 , causing the internal air to pass through the first and second heat exchangers 21 and 31 , and discharging the internal air to the outside of the indoor units 20 and 30 , and first and second indoor fan motors 23 and 33 for rotating the first and second indoor fans 22 and 32 .
[0024] The first and second indoor units 20 and 30 respectively further include first and second indoor electric valves 25 and 35 for adjusting the amount of the refrigerant flowing into the first and second indoor units 20 and 30 , first and second inlet temperature sensors 24 and 34 installed at pipes located at inlets of the first and second indoor heat exchangers 21 and 31 , through which the refrigerant enters into the first and second indoor heat exchangers 21 and 31 (in the cooling mode), first and second indoor temperature sensors 27 and 37 for measuring the temperatures of spaces, in which the first and second indoor units 21 and 31 are installed, and the first and second indoor unit microcomputers 26 and 36 for controlling the components of the first and second indoor units 20 and 30 and for communicating data with the outdoor unit microcomputer 18 .
[0025] Now, with reference to FIG. 3 , a method for operating the multi air conditioning system shown in FIGS. 1 and 2 will be described in detail. When the operation of the outdoor unit microcomputer 18 is started, the outdoor unit microcomputer 18 communicates data with the first and second indoor unit microcomputers 26 and 36 and inspects operating conditions of the first and second indoor units 20 and 30 . Then, the outdoor unit microcomputer 18 determines whether or not both the first and second indoor units 20 and 30 are in a stopped state (S 40 ). In case that both the first and second indoor units 20 and 30 are in the stopped state, then the indoor electric valves 25 and 35 of the first and second indoor units 20 and 30 are completely opened so that pressure equilibration of the overall route of the refrigerant is performed (S 58 ).
[0026] In case that both the first and second indoor units 20 and 30 are not in the stopped state, it is determined whether or not the multi air conditioning system is operated in the heating mode (S 42 ). In case that it is determined that the multi air conditioning system is not operated in the heating mode, the method is returned to the initial step. If, however, it is determined that the multi air conditioning system is operated in the heating mode, then it is inspected whether or not at least one of the first and second indoor unit 20 and 30 is in the stopped state (S 44 ).
[0027] In case that it is inspected that at least one of the first and second indoor units 20 and 30 is not in the stopped state, then it is determined that all of the first and second indoor units 20 and 30 are operated, and the first and second indoor electric valves 25 and 35 of the first and second indoor units 20 and 30 are normally controlled (S 60 ). If it is inspected that at least one of the first and second indoor units 20 and 30 is in the stopped state, then it is determined whether or not the operating capacity of the system is changed (S 46 ).
[0028] The change of the operating capacity of the system is caused by the change of the states of the first and second indoor units 20 and 30 , i.e., the change of the operating state to the stopped state or the change of the stopped state to the operating state. In case that the operating capacity of the system is changed, the opening degree of the indoor electric valve of the indoor unit in the stopped state is initialized to a predetermined value, and a reference time is initialized (S 62 ).
[0029] Here, the opening degree of the indoor electric valve of the indoor unit in the stopped state varies according to the system. The opening degree of the indoor electric valve of the indoor unit in the stopped state is set to a proper value by experimentation, and is stored in advance by the microcomputer. Further, the reference time is set in consideration of a time taken to stabilize the system from the time when the operating capacity of the overall system is changed.
[0030] In case that it is determined that the operating capacity of the system is not changed in step S 46 , it is determined whether or not the reference time has elapsed (S 48 ). In case that it is determined that the reference time had not elapsed, it is determined that the system is not stabilized after the change of the operating capacity of the system, and the method is returned to the initial step, and in case that it is determined that the reference time has elapsed, then the temperature of the inlet of the indoor heat exchanger of the indoor unit in the stopped state is measured by the inlet temperature sensor of the indoor unit in the stopped state, and the temperature of the indoor space, in which the indoor unit in the stopped state is installed, is measured by the indoor temperature sensor of the indoor unit in the stopped state (S 50 ).
[0031] Thereafter, it is determined whether or not the temperature of the inlet of the indoor heat exchanger of the indoor unit in the stopped state is lower than a first reference temperature (S 52 ). The first reference temperature varies according to the type of compressor 11 or other configurations of the system. Preferably, in this embodiment, the first reference temperature is set above the temperature of the indoor space, in which the indoor unit in the stopped state is installed, by approximately 20° C. That is, in step S 52 , it is determined whether or not the temperature of the inlet of the indoor heat exchanger of the indoor unit in the stopped state is lower than the value obtained by adding a designated temperature to the temperature of the indoor space measured by the indoor temperature sensor.
[0032] In case that it is determined that the temperature of the inlet of the indoor heat exchanger of the indoor unit in the stopped state is lower than the first reference temperature, the opening degree of the indoor electric valve of the indoor unit in the stopped state is increased (S 64 ). When the opening degree of the indoor electric valve of the indoor unit in the stopped state is excessively low, the refrigerant is trapped in the indoor heat exchanger of the indoor unit in the stopped state and changed in phase, thereby decreasing the temperature of the inlet of the indoor heat exchanger below the first reference temperature. Thus, in this case, the opening degree of the indoor electric valve is increased so that the refrigerant is not trapped in the indoor heat exchanger of the indoor unit in the stopped state, thereby increasing the amount of the refrigerant circulating along the route of the refrigerant.
[0033] In case that it is determined that the temperature of the inlet of the indoor heat exchanger of the indoor unit in the stopped state is not lower than the first reference temperature, it is determined whether or not the temperature of the inlet of the indoor heat exchanger of the indoor unit in the stopped state is higher than a second reference temperature (S 54 ).
[0034] The second reference temperature varies according to the capacity of the compressor 11 or other configurations of the system. Preferably, in this embodiment, the second reference temperature is set above the temperature of the indoor space, in which the indoor unit in the stopped state is installed, by approximately 30° C. That is, in step S 54 , it is determined whether or not the temperature of the inlet of the indoor heat exchanger of the indoor unit in the stopped state is higher than the value obtained by adding a designated temperature to the first reference temperature.
[0035] In case that it is determined that the temperature of the inlet of the indoor heat exchanger of the indoor unit in the stopped state is higher than the second reference temperature, then the opening degree of the indoor electric valve of the indoor unit in the stopped state is decreased (S 66 ). When the opening degree of the indoor electric valve of the indoor unit in the stopped state is excessively high, an excessively large amount of the refrigerant in a high-temperature and high-pressure state discharged from the compressor flows into the indoor heat exchanger of the stopped indoor unit, thereby increasing the temperature of the inlet of the indoor heat exchanger above the second reference temperature. Thus, in this case, the opening degree of the indoor electric valve is decreased so that the amount of the refrigerant flowing into the indoor heat exchanger of the indoor unit in the stopped state is decreased and a large amount of the refrigerant flows into the indoor unit in the operating state.
[0036] In case that it is determined that the temperature of the inlet of the indoor heat exchanger of the indoor unit in the stopped state is not higher than the second reference temperature, then it is determined that the opening degree of the indoor electric valve of the indoor unit in the stopped state is proper, and the set opening degree of the indoor electric valve is maintained (S 56 ).
[0037] In this embodiment, the first and second inlet temperature sensors 24 and 34 are installed at the inlets of the indoor heat exchangers (in the cooling mode), and the temperature sensors for indirectly measuring the amount of the refrigerant flowing into the indoor heat exchanger of the indoor unit in the stopped state are installed around the pipes connected to the outlets of the indoor heat exchangers (in the cooling mode), the indoor heat exchangers, or peripheries of the indoor heat exchangers. Here, the first reference temperature and the second reference temperatures are set to different values.
[0038] As apparent from the above description, the exemplary embodiment provides a multi air conditioning system comprising a plurality of indoor units, which adjusts the amount of refrigerant flowing into some indoor units in a stopped state, and a method for operating the multi air conditioning system, thereby causing the proper amount of the refrigerant to flow into indoor units in an operating state.
[0039] Although an embodiment has been shown and described, it would be appreciated by those skilled in the art that changes may be made in this embodiment without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.
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A multi air conditioning system for adjusting the amount of refrigerant flowing into indoor units determined to be in a stopped state, to improve the overall system efficiency, and a method for operating the multi air conditioning system. The method includes determining whether or not some indoor units are in a stopped state; measuring temperatures of heat exchangers of the indoor units in the stopped state; and changing opening degrees of valves installed in those indoor units determined to be in the stopped state to change the amount of refrigerant flowing therein if the temperatures of the heat exchangers of the stopped indoor units deviate from a reference range.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 60/866,569, filed 20 Nov. 2006, which is incorporated by reference herein in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention is related to the measuring devices and measurement of anatomical pathologies.
[0004] 2. Description of the Related Art
[0005] The ability to accurately measure the dimensions of anatomical structures is of vital importance. In many cases, the anatomical geometry defines the treatment. A small object, small hole, or short length of anatomical pathology can go untreated because it has little to no clinical significance. Larger objects, holes, and longer length of anatomical pathology may lead to adverse clinical outcomes.
[0006] Additionally, many anatomical pathologies are treated with devices, including implantable devices, that are sized to fit the pathology. Knowledge of the specific size of the pathology aids the selection of an appropriately sized treatment device. Using trial and error techniques to determine the proper size of an implantable treatment device undesirably prolongs the surgical procedure, and fitting and removing improperly sized devices often further traumatizes the already-injured anatomical site.
[0007] Existing devices do not easily measure tunnel defects in soft tissue within body structures. Tunnel defects can be found in the heart (e.g., patent foramen ovale (PFO), left atrial appendage, mitral valve prolapse, aortic valve defects). Tunnel defects can be found through out the vascular system (e.g., venous valve deficiency, vascular disease, vulnerable plaque, aneurysms (e.g., neurovascular, abdominal aortic, thoracic aortic, peripheral). Tunnel defects can be found in non vascular systems (e.g., stomach with GERD, prostate, lungs).
[0008] A device for measuring the width of a distended defect in tissue is disclosed. The device has a longitudinal axis. The device can have a first elongated member. The first elongated member can be configured to expand away from the longitudinal axis. The device can have a second elongated member. The first elongated member can be opposite with respect to the longitudinal axis to the second elongated member. The second elongated member can be configured to expand away from the longitudinal axis. The device can have a lumen, for example, in a catheter. The device can have a porous cover on the lumen.
[0009] A method for sizing a tunnel defect. The method can include inserting a measurement tool into the tunnel defect. The method can include distending the tunnel defect into a distended configuration. The method can include measuring the tunnel defect in the distended configuration. Distending can include radially expanding the measurement tool. Measuring can include bending the first measuring wire around a front lip of the tunnel defect. Measuring can include emitting a contrast fluid in the tunnel defect.
BRIEF SUMMARY OF THE INVENTION
[0010] Tissue distension devices can be deployed to tunnel defects in tissue. The tissue distension devices can be used to substantially close tunnel defects to treat, for example, patent foramen ovale (PFO), left atrial appendage, mitral valve prolapse, aortic valve defects. Examples of tissue distension devices include those disclosed in U.S. patent application Ser. No. 10/847,909, filed 19 May 2004; Ser. No. 11/184,069, filed 19 Jul. 2005; and Ser. No. 11/323,640, filed 3 Jan. 2006, all of which are incorporated by reference herein in their entireties.
[0011] To select a properly fitting tissue distension device, a measuring tool can first be deployed to measure the size of the tunnel defect. The tunnel defect can be measured in a relaxed or distended configuration. The tunnel defect can be distended by the measuring tool before or during measurement.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 illustrates a variation of the measurement tool in a first configuration.
[0013] FIGS. 2 a, 2 b, 3 a and 3 b illustrate variations of cross-section A-A of FIG. 1 .
[0014] FIGS. 4 and 5 illustrate various embodiments of cross-section B-B of FIG. 1 .
[0015] FIGS. 5 through 11 and 13 through 16 illustrate variations of the measurement tool in a second configuration.
[0016] FIG. 12 is a close-up view of the a portion of the measurement tool of FIG. 11 including the first measuring wire only, for illustrative purposes, transforming from a radially contracted to a radially expanded configuration.
[0017] FIGS. 17 through 27 illustrate variations of the measuring wire.
[0018] FIG. 28 illustrates a variation of cross-section C-C of FIG. 27 .
[0019] FIG. 29 illustrates a variation of cross-section D-D of FIG. 27 .
[0020] FIG. 30 illustrates a variation of a wire assembly.
[0021] FIG. 31 illustrates a variation of a wire sub-assembly.
[0022] FIG. 32 illustrates a variation of a wire assembly.
[0023] FIG. 33 illustrates a variation of a wire sub-assembly.
[0024] FIG. 34 illustrates a variation of a wire assembly.
[0025] FIGS. 35-37 illustrate variations of the measurement tool.
[0026] FIGS. 38 a and 38 b illustrate various sections of tissue having a tunnel defect.
[0027] FIG. 39 illustrates the tunnel defect of FIG. 38 a or 38 b.
[0028] FIGS. 40 through 42 illustrate a variation of a method for deploying an embodiment of the measurement tool.
[0029] FIGS. 43 and 44 illustrate a variation of a method for using various embodiments of the measurement tool.
[0030] FIG. 45 illustrates a variation of a method for using a variation of the measurement tool.
[0031] FIGS. 46 and 47 illustrate a variation of a method for using a variation of the measurement tool.
[0032] FIGS. 48 and 49 illustrate a variation of a method for using a variation of the measurement tool.
DETAILED DESCRIPTION
[0033] FIG. 1 illustrates an anatomical measurement tool 2 , such as a tool for measuring the width in a relaxed and/or distended configuration of a tunnel defect 156 in tissue 154 , in a radially contracted configuration. The measurement tool 2 can have a longitudinal axis 16 . The anatomical measurement tool 2 can have a catheter 26 , a first measuring wire 100 a, and a second measuring wire 100 b. The measuring wires 100 can be deformable, resilient, or combinations thereof over the length of the measuring wires 100 .
[0034] The catheter 26 can have a catheter porous section 20 . The catheter 26 can be entirely substantially non-porous. The catheter 26 can have a catheter non-porous section 24 . The catheter porous section 20 can partially or completely circumferentially surround the catheter 26 . The catheter porous section 20 can have holes or pores in the catheter outer wall 28 . The pores can have pore diameters from about 1 μm (0.04 mil) to about 1 mm (0.04 in.), more narrowly from about 2 μm (0.08 mil) to about 300 μm (10 mil), for example about 150 μm (6.0 mil).
[0035] The first 100 a and second measuring wires 100 b can each have at least one wire radially constrained section 10 and at least one wire radially unconstrained section 8 . The measuring wires 100 can transition from the wire constrained sections 10 to the wire radially unconstrained sections 8 at the wire proximal sheath ports 22 . The first 100 a and second measuring wires 100 b between the wire proximal sheath ports 22 and the wire distal anchor 14 can be the radially unconstrained sections 8 . The measuring wires 100 can be distally fixed to the catheter 26 at a wire distal anchor 14 . The wire distal anchor 14 can be a hinged or otherwise rotatable attachment, for example, to allow the measuring wire 100 to rotate away from the longitudinal axis 16 at the wire distal anchor 14 during use.
[0036] The measurement tool 2 can have a tip 12 extending from a distal end of the catheter 26 . The tip 12 can be blunt or otherwise atraumatic (e.g., made or coated with a softer material than the catheter 26 , made with a soft substantially biocompatible rubber tip 12 ). A guide lumen 4 can extend from the tip 12 . The guide lumen 4 can be configured to slidably receive a guidewire 170 . The guide lumen 4 can exit through a dimple in the tip 12 . The tip 12 need not be dimpled at the exit of the guide lumen 4 .
[0037] FIG. 2 a illustrates that the catheter 26 can have a catheter outer wall 28 . The catheter outer wall 28 can be porous, or non-porous, or partially porous and partially non-porous. The catheter 26 can have a fluid lumen 36 . The guide lumen 4 can be configured central to the cross-section of the catheter 26 or offset from the center of the cross-section, for example attached to the catheter outer wall 28 . The guide lumen can have a guide lumen wall 34 .
[0038] The first measuring wire 100 a can removably and slidably reside in or removably and slidably attach to a recessed or raised first track 32 in the catheter outer wall 28 . The second measuring wire 100 b can removably and slidably reside in or removably and slidably attach to a recessed or raised second track 40 in the catheter outer wall 28 .
[0039] To transform the measurement tool 2 from the radially contracted configuration to the radially expanded configuration, the first 100 a and second measuring wires 100 b in the wire radially constrained section 10 can be longitudinally translated, as shown by arrows 54 (not shown in FIG. 2 a ), in a distal direction. The first and second wires, for example, rotatably fixed at the wire distal anchor 14 and not radially constrained between the wire proximal sheath ports 22 and the wire distal anchor 14 , can translate, as shown by arrows 52 (not shown in FIG. 2 a ), radially outward from the longitudinal axis 16 .
[0040] FIG. 2 b illustrates that the measuring wires 100 can have a configuration substantially equivalent to the configuration of the respective track 32 or 40 . The measuring wires 100 and catheter 26 can be configured to create a substantially smooth, flush, regular configuration to the radial exterior cross-section (e.g., at A-A) of the measurement tool 2 when the wires 100 are in a contracted configuration. For example, the radially exterior cross-section (e.g., at A-A) of the measurement tool 2 can be configured substantially as a circle when the wires 100 are in a contracted configuration.
[0041] FIG. 3 a illustrates that the first 100 a and second measuring wires 100 b in the wire radially unconstrained section 8 can be adjacent to, and reside on or attach to, the catheter outer wall 28 . The catheter outer wall 28 can have no tracks for the measuring wires 100 .
[0042] FIG. 3 b illustrates that the measuring wires 100 can have a low-profile configuration. The low-profile configuration can have a cross-sectional configuration (e.g., at A-A) of a semi-circle, crescent, arc, oval, rectangle, or combinations thereof. The low-profile configuration can have a larger angular dimension than radial dimension, when measured with respect to the substantial center of the measurement device in the longitudinal direction. The measuring wires 100 and catheter 26 can be configured to create a substantially smooth, flush and regular exterior surface of the measurement tool 2 when the wires 100 are in a contracted configuration.
[0043] FIG. 4 illustrates that the first 100 a and second measuring wires 100 b can be slidably attached to and/or encased by first 48 and second sheaths 50 , respectively. The interior of the sheaths can be coated with a low-friction material (e.g., polytetraflouroethylene (PTFE), such as Teflon® by E.I. du Pont de Nemours and Company, Wilmington, Del.).
[0044] FIG. 5 illustrates that the first sheath 48 and/or the second sheath 50 can be inside the catheter 26 (i.e., radially interior to the catheter outer wall 28 ).
[0045] The wire distal anchor 14 and wire sheaths 48 and/or 50 can be fixedly attached to the catheter 26 . The wire distal anchor 14 and wire sheaths 48 and/or 50 can be slidably attached to the catheter 26 .
[0046] The catheter outer wall 28 can be porous and/or non-porous, for example at different lengths along the catheter 26 . For example, the catheter outer wall 28 in FIGS. 3 a and 3 b can be porous and the catheter outer wall 28 in FIGS. 4 and 5 can be non-porous.
[0047] The catheter 26 and/or tip 12 can have a stop. The stop can be longitudinally fixed with respect to the catheter 26 and/or the tip 12 . The stop can be the tip 12 , for example if the diameter of the tip 12 is larger than the diameter of the wire distal anchor 14 . The stop can be configured to interference fit against the wire distal anchor 14 when the wire distal anchor 14 is distally translated beyond a maximum translation point with respect to the catheter 26 and/or tip 12 .
[0048] FIG. 6 illustrates the measurement tool 2 in a radially expanded configuration. The first 100 a and second measuring wires 100 b in the wire radially unconstrained section 8 can bow, flex, or otherwise be radially distanced or translate, as shown by arrows 52 , with respect to the longitudinal axis 16 from the catheter 26 . The first 100 a and second measuring wires 100 b can expand in a single plane (i.e., be coplanar).
[0049] The measuring wires 100 can be longitudinally translated, as shown by arrows 54 , in the wire radially constrained sections 10 . The first 100 a and second measuring wires 100 b in the wire radially unconstrained sections 8 can be radially expanded or otherwise translated, as shown by arrows, away from the catheter 26 (e.g., longitudinal axis 16 ) into a radially expanded configuration, for example by distally translating the measuring wires 100 in the wire radially constrained sections 10 . The first 100 a and second measuring wires 100 b in the wire radially unconstrained sections 8 can be radially contracted or otherwise translated toward the catheter 26 (e.g., longitudinal axis 16 ) into a radially contracted configuration, for example by proximally translating the measuring wires 100 in the wire radially constrained section 10 .
[0050] FIG. 7 illustrates that the catheter porous section 20 can have a porous section length 56 . The longitudinal distance between the wire distal anchor 14 and the wire proximal sheath ports 22 (i.e., the wire radially unconstrained section 8 ) can be an unconstrained wire longitudinal length 58 . The unconstrained wire longitudinal length 58 can be less than, substantially equal to (as shown in FIGS. 1 and 6 ), or greater than (as shown in FIG. 7 ) the catheter non-porous section 24 .
[0051] FIG. 8 illustrates that the first and second wires can have substantially discrete angles when the wires are in the radially expanded configurations. Each wire 100 can have a wire first hinge point 60 and a wire second hinge point 66 . The wire hinge points 60 and/or 66 can be biased (e.g., before the measurement tool 2 is configured in the first configuration) to bend when the tension on the measuring wire 100 is decreased. The wire hinge points 60 and/or 66 can have hinges 106 , bends, seams, links, other articulations, or combinations thereof.
[0052] The wire first hinge point 60 can have a wire first hinge angle 62 a. The wire second hinge point 86 can have a wire second hinge angle 62 b. In a radially expanded configuration, the wire hinge first and second angles 62 a and 62 b can be from about 10° to about 170°, more narrowly from about 30° to about 150°, yet more narrowly from about 45° to about 135°, for example about 125°. The wire hinge angle 62 when the measurement tool 2 is in a radially expanded configuration can be equivalent to the hinge angle 62 , described infra, when the measurement tool 2 is in a radially contracted configuration.
[0053] FIG. 9 illustrates that the measurement tool 2 can have about 12 measuring wires 100 . The measuring wires 100 can be radially expandable in a configuration where the first measuring wire 100 a deploys substantially longitudinally adjacent to a third measuring wire 100 c. The measuring wires 100 can be radially expandable in a configuration where the second measuring wire 100 b deploys substantially longitudinally adjacent to a fourth measuring wire 100 d.
[0054] The measuring wires 100 can each have a unique or paired longitudinal position for their wire proximal sheath ports 22 and wire distal anchors 14 . For example, the first 100 a and second measuring wires 100 b can exit from wire first proximal sheath ports 22 a (not shown on FIG. 9 ) and can be fixed at wire first distal anchors 14 a (not shown on FIG. 9 ). The third 100 c and fourth measuring wires 100 d can exit from wire second proximal sheath ports 22 b (not shown on FIG. 9 ) and can be fixed at wire second distal anchors 14 b (not shown on FIG. 9 ). The wire first distal anchors 14 a can be distal to the wire second distal anchors 14 b. The wire first proximal sheath ports 22 a can be at a substantially equivalent longitudinal position to the wire second distal anchors 14 b. The wire second distal anchors 14 b can be distal to the wire second proximal sheath ports 22 b. This longitudinal spacing of the wire distal anchors 14 and wire proximal sheath ports 22 can be used for all of the measuring wires 100 .
[0055] The measuring wires 100 on each side of the catheter 26 (e.g., the first, third, fifth, seventh, ninth and eleventh measuring wires or the second, fourth, sixth, eighth, tenth and twelfth measuring wires) can pass through the same or different sheaths.
[0056] FIG. 10 illustrates that the measuring wires 100 can have distal ends that are not attached to the catheter 26 when the measuring wires 100 are in radially expanded configurations. Any or all measuring wire 100 can have a terminal end 80 . When the measurement-tool 2 is in a radially expanded configuration, the terminal ends 80 can be unattached to the catheter 26 . When the measurement tool 2 is in a radially expanded configuration, the measuring wires 100 can have a medial turn 82 , bend, hinge 106 , or otherwise angle medially between the terminal ends 80 and the wire proximal ports. A length of the measuring wires 100 can be biased to turn or bend medially when that length of the measuring wire 100 is in a relaxed configuration. The measurement tool 2 can have about eight measuring wires 100 .
[0057] FIG. 11 illustrates that the measuring wires 100 can form a substantially circular or oval loop when the measuring wire 100 is in the radially expanded configuration. The measurement tool 2 can have six measuring wires 100 . Each measuring wire 100 can have a separate proximal sheath port 22 (e.g., first, second, third, fourth, fifth and sixth proximal sheath ports 22 a, 22 b, 22 c, 22 d, 22 e, and 22 f ), and wire distal anchors 14 (e.g., wire first, second, third, fourth, fifth and sixth distal anchors 14 a, 14 b, 14 c, 14 d, 14 e and 14 f )
[0058] FIG. 12 illustrates that the loop of wire radially unconstrained section 8 can expand when the measuring wires 100 transform from the radially contracted configuration to the radially expanded configuration. The measuring wires 100 can be longitudinally translated, as shown by arrow 54 , in the wire radially constrained sections 10 . Along the length of the measuring wires 100 near the wire proximal port, the measuring wires 100 can translate along the longitudinal wire-axis, as shown by arrow 84 . The measuring wires 100 in the wire radially unconstrained sections 8 can be radially expanded or otherwise translated, as shown by arrow 52 , away from the catheter 26 (e.g., longitudinal axis 16 ) into a radially expanded configuration, for example by distally translating the measuring wires 100 in the wire radially constrained sections 10 . The measuring wires 100 in the wire radially unconstrained sections 8 can be radially contracted or otherwise translated toward the catheter 26 (e.g., longitudinal axis 16 ) into a radially contracted configuration, for example by proximally translating the measuring wires 100 in the wire radially constrained section 10 .
[0059] FIG. 13 illustrates that the measuring wires 100 can exit from the respective wire sheaths at the respective wire proximal ports. The measuring wires 100 can all exit the wire proximal ports on the same side of the catheter 26 , or immediately turn to the same side of the catheter 26 after exiting the proximal wire ports. When the measurement tool 2 is in a radially expanded configuration, the measuring wires 100 can have a proximal turn, bend, hinge 106 , or otherwise angle proximally after exiting the proximal wire port. When the measurement tool 2 is in a radially expanded configuration, the measuring wires 100 can have a medial turn 82 , bend, hinge, or otherwise angle toward the longitudinal axis 16 , for example, between the proximal bend 90 and the terminal end 80 . Any length of the measuring wires 100 can be biased to turn or bend when that length of the measuring wire 100 is in a relaxed configuration. FIG. 14 illustrates that the measuring wire 100 can have a proximal turn, bend, hinge 106 , or otherwise angle proximally.
[0060] FIG. 15 illustrates that the catheter 26 can be removably or fixedly attached to a coupler 96 . The coupler 96 can be removably or fixedly attached to a handle 98 . The coupler 96 can be made from any material disclosed herein including rubber, elastic, or combinations thereof. The coupler 96 can have a substantially cylindrical configuration. The coupler 96 can have threads. The coupler 96 can have slots. The couple can have a joint and/or hinge 106 .
[0061] The coupler 96 can be flexible. The coupler 96 can substantially bend, for example, permitting the longitudinal axis 16 of the handle 98 to be a substantially non-zero angle (e.g., from about 0° to about 90°) with respect to the longitudinal axis 16 of the catheter 26 . The coupler 96 can permit substantially resistance free rotation between the longitudinal axis 16 of the catheter 26 and the longitudinal axis 16 of the handle 98 .
[0062] FIG. 16 illustrates that the coupler 96 can be removably or fixedly attached to the catheter 26 on the proximal and distal end of the coupler 96 . The coupler 96 can have and/or be proximally adjacent to the wire proximal sheath ports 22 .
[0063] The measuring wire 100 can have a low and/or high friction surface. The measuring wire 100 can have a higher friction surface on the side of the measuring wire 100 radially exterior to the catheter 26 and a lower friction surface on the side of the measuring wire 100 radially interior to the catheter 26 . The measuring wire 100 can have a surface having a substantially uniform friction around substantially the entire measuring wire 100 .
[0064] The surface of the measuring wire 100 can be textured, for example knurled, pebbled, ridged, Toped, or combinations thereof. The surface of the measuring wire 100 can be textured on the side of the measuring wire 100 radially exterior to the catheter 26 and not substantially textured on the side of the measuring wire 100 radially interior to the catheter 26 . The surface of the measuring wire 100 can be substantially uniformly textured around substantially the entire measuring wire 100 .
[0065] The surface of the measuring wire 100 can be encrusted with a granulized material, for example diamond, sand, a polymer, the material from which the measuring wire 100 is made, any other material described herein, or combinations thereof. The surface of the measuring wire 100 can be encrusted on the side of the measuring wire 100 radially exterior to the catheter 26 and not substantially encrusted on the side of the measuring wire 100 radially interior to the catheter 26 . The surface of the measuring wire 100 can be substantially uniformly encrusted around substantially the entire measuring wire 100 .
[0066] FIG. 17 illustrates that the measuring wire 100 can have a wire body 104 and one or more markers 102 . The wire body 104 can have no markers 102 . The markers 102 can be echogenic, radiopaque, magnetic, or configured to be otherwise visible by an imaging technique known to one having ordinary skill in the art. The markers 102 can be made from any material disclosed herein including platinum (e.g., pure or as powder mixed in glue).
[0067] The markers 102 can be uniformly and/or non-uniformly distributed along the length of the wire body 104 . The markers 102 can be uniformly and/or non-uniformly distributed along the radius of the wire body 104 . The markers 102 can be separate and discrete from the wire body 104 . The markers 102 can be attached to the wire body 104 . The markers 102 can be incorporated inside the wire body 104 . The marker 102 can have configuration symmetrical about one, two, three, or more axes. The marker 102 can have an omnidirectional configuration. The marker 102 can have a configuration substantially spherical, ovoid, cubic, pyramidal, circular, oval, square, rectangular, triangular, or combinations thereof. The marker's 102 radius can be smaller than or substantially equal to the wire body's 104 radius at the location of the marker 102 . FIG. 18 illustrates that the marker's 102 radius can be greater than the wire body's 104 radius at the location of the marker 102 .
[0068] FIG. 19 illustrates that the marker 102 can have a unidirectional configuration. The marker 102 can be configured in the shape of an arrow. All or subsets of the markers 102 on a wire body 104 can be aligned, for example all of the unidirectionally configured markers 102 can be oriented in the same longitudinal or radial direction (e.g., distally, proximally) along the wire body 104 .
[0069] FIG. 20 illustrates that the markers 102 can have alphanumeric characters. The alphanumeric characters can increase in value (e.g., 1, 2, 3, or A, B, C, or I, II, III) incrementally along the length and/or radius of the wire. The markers 102 can include unit values (e.g., mm, in.)
[0070] FIG. 21 illustrates that the markers 102 can be configured as a cylinder (e.g., disc), ring (e.g., toroid, band), partial cylinder, partial ring, or combinations thereof. FIG. 22 illustrates that the markers 102 can be integrated with the measuring wire 100 . FIG. 23 illustrates that the markers 102 can be wires or threads. The markers 102 can extend along the length and/or radius of the wire body 104 .
[0071] FIG. 24 illustrates that the wire body 104 can have one or more hinges 106 . The hinges 106 can be configured to allow bending or other distortion of the wire body 104 . The hinges 106 can be a change in material and/or a configuration. The hinge 106 can be configured by material absent from a side of the wire body 104 . For example, the hinge 106 can be an angled cut (i.e., the angled cut is not necessarily cut. The angled cut can be cut, crimped, molded, etched, or combinations thereof) in the side of the wire body 104 . The hinge 106 can have a stop to limit the bending of the measuring wire 100 . For example, for an angle cut hinge 106 , the stop can be the side of the hinge 106 . The hinge 106 can have a hinge angle 62 . The hinge angle 62 can correlate to the maximum angle of bending. The hinge angle 62 can be, as described elsewhere herein, or from about 1° to about 179°, more narrowly from about 15° to about 90°, yet more narrowly from about 20° to about 60°, for example about 45°.
[0072] FIG. 25 illustrates that the hinge 106 can be a round cut. For example, the hinge 106 can be circular (e.g., semi-circular), oval, or combinations thereof. FIG. 26 illustrates that the hinge 106 can be a rectangular cut. For example, the hinge 106 can be rectangular (e.g., square). The hinge 106 can be any combination of the aforementioned configurations. The hinges 106 with various configurations can be on the same wire body 104 . The hinges 106 can be on various sides of, or otherwise distributed at various angles around, the measuring wire 100 .
[0073] FIGS. 27 through 29 illustrate that the wire body 104 can be hollow. The measuring wire 100 can have one or more wire conduits 114 on the radial interior of the wire body 104 . The measuring wire 100 can have one or more wire conduit ports 110 in fluid communication with the one or more wire conduits 114 and the radial exterior of the measuring wire 100 . The wire conduit ports 110 can regulate release of material inside of the wire conduits 114 . For example, the wire conduit ports 110 (or wire conduits 114 themselves) can have and/or be filled and/or covered by an osmotic material, such as a matrix or film. The wire conduit ports 110 can all be on the same side of the measuring wire 100 . The wire conduit ports 110 can be on various sides of, or otherwise distributed at various angles around, the measuring wire 100 .
[0074] FIG. 30 illustrates that a wire assembly 118 can have a measuring wire 100 connected to one or more other elements. The first measuring wire 100 a can be connected to the second measuring wire 100 b at a distal collar 122 and/or a proximal collar 124 . The first measuring wire 100 a can be attached to and/or integral with the distal collar 122 and/or proximal collar 124 . The second measuring wire 100 b can be attached to and/or integral with the distal collar 122 and/or proximal collar 124 . The wire assembly 118 can be made by being pressed, molded or cut from a tube, for example laser cut from a Nitinol tube. The collars can be cylindrical, have a rectangular, square, triangular, pentagonal, octagonal, oval cross section, or combinations thereof with respect to a longitudinal axis 16 .
[0075] FIG. 31 illustrates that a wire sub-assembly 120 can have a first measuring wire 100 a connected to one or more other elements. The first measuring wire 100 a can be connected to a distal collar 122 and/or a proximal collar 124 . The first measuring wire 100 a can be attached to and/or integral with the distal collar 122 and/or proximal collar 124 . The wire sub-assembly 120 can be made by being pressed, molded, or cut from a tube, for example laser cut from a Nitinol tube.
[0076] FIG. 32 illustrates that the wire assembly 118 can have a first wire sub-assembly 134 and a second wire sub-assembly 136 . The first wire sub-assembly 134 and the second wire sub-assembly 136 can be integral and/or attached or separate. The first wire sub assembly can be positioned 180° opposite to the positioning of the second wire sub-assembly 136 , with respect to a longitudinal axis 16 of the wire assembly 118 .
[0077] FIG. 33 illustrates that the wire assembly 118 can have a first measuring wire 100 a that can have one or more hinges 106 . For example, the first measuring wire 100 a can have a wire distal hinge 144 and/or a wire proximal hinge 142 . The wire distal hinge 144 can be at the connection between the first measuring wire 100 a and the first wire distal collar 126 . The wire proximal hinge 142 can be at the connection between the first measuring wire 100 a and the first wire proximal collar 128 . The wire distal hinge 144 and the wire proximal hinge 142 can be configured to bend or otherwise rotate the first measuring wire 100 a radially outward from the central longitudinal axis 16 of the wire sub-assembly 120 when the measurement tool 2 is in a radially expanded configuration.
[0078] The wire can have a wire first hinge 138 and/or a wire second hinge 140 . The wire first and/or second hinges can be on the first measuring wire 100 a, for example, between the wire distal hinge 144 and the wire proximal hinge 142 . The wire first hinge 138 and/or the wire second hinge 140 can be configured to bend or otherwise rotate the first measuring wire 100 a radially inward from the central longitudinal axis 16 of the wire sub-assembly 120 when the measurement tool 2 is in a radially expanded configuration.
[0079] FIG. 34 illustrates that the wire assembly 118 can have wire distal hinges 144 , and/or wire proximal hinges 142 , and/or wire first hinges 138 , and/or wire second hinges 140 on the first measuring wire 100 a and/or the second measuring wire 100 b.
[0080] FIG. 35 illustrates that the measurement tool 2 can have a wire assembly 118 connected to the catheter 26 . The wire assembly 118 can be integrated and/or attached to the catheter 26 . For example, the proximal collar 124 and/or distal collar 122 can be integral with and/or fixably and/or slidably attached to the catheter 26 . For example, the distal collar 122 can be slidably attached to the catheter 26 near or on the tip 12 and/or the proximal collar 124 can be fixedly attached to the catheter 26 .
[0081] The wire assembly 118 can have a retraction leader 148 . The retraction leader 148 can be integral with or attached to the distal collar 122 . The retraction leader 148 can be rigid and/or flexible. The retraction leader 148 can be radially external to the catheter 26 and/or the retraction leader 148 can be slidably attached to a retraction leader conduit 146 or channel inside of the catheter 26 . The retraction leader conduit 146 or channel can be partially or completely open to the radial outside of the catheter 26 . For example, the retraction leader conduit 146 can be open to the radial outside of the catheter 26 for all or part of the retraction leader conduit's 146 length distal to the proximal conduit.
[0082] FIG. 36 illustrates that the first wire sub-assembly 134 and the second wire sub-assembly 136 can be integral with and/or attached to the catheter 26 . The first wire sub-assembly 134 can be proximal, distal, or overlapping with the longitudinal position of the second wire sub-assembly 136 on the catheter 26 . The second wire distal collar 130 can be distal and/or proximal to the first wire distal collar 126 . The second wire proximal collar 132 and be distal and/or proximal to the first wire proximal collar 128 . The first wire distal collar 126 can be attached to or integral with a first retraction leader 148 . The second wire distal collar 130 can be attached to or integral with a second retraction leader 148 .
[0083] FIG. 37 illustrates that the measurement tool 2 can have a catheter sheath 152 . The catheter sheath 152 can be slidably attached to the catheter 26 . In an undeployed configuration, the catheter sheath 152 can be radially outside and longitudinally overlapping the wire assembly 118 . The catheter sheath 152 can be sufficiently rigid to retain the wire assembly 118 in a radially contracted configuration. The catheter sheath 152 can have, for example at a distal end of the catheter sheath 152 , a catheter sheath port 150 through which the catheter 26 and other elements (e.g., the wire assembly and measuring wires), can exit and enter the catheter sheath 152 .
[0084] Any or all elements of the measurement tool 2 and/or other devices or apparatuses described herein can be made from, for example, a single or multiple stainless steel alloys, nickel titanium alloys (e.g., Nitinol), cobalt-chrome alloys (e.g., ELGILOY® from Elgin Specialty Metals, Elgin, Ill.; CONICHROME® from Carpenter Metals Corp., Wyomissing, Pa.), nickel-cobalt alloys (e.g., MP35N® from Magellan Industrial Trading Company, Inc., Westport, Conn.), molybdenum alloys (e.g., molybdenum TZM alloy, for example as disclosed in International Pub. No. WO 03/082363 A2, published 9 Oct. 2003, which is herein incorporated by reference in its entirety), tungsten-rhenium alloys, for example, as disclosed in International Pub. No. WO 03/082363, polymers such as polyethylene teraphathalate (PET), polyester (e.g., DACRON® from E. I. Du Pont de Nemours and Company, Wilmington, Del.), polypropylene, aromatic polyesters, such as liquid crystal polymers (e.g., Vectran, from Kuraray Co., Ltd., Tokyo, Japan), ultra high molecular weight polyethylene (i.e., extended chain, high-modulus or high-performance polyethylene) fiber and/or yarn (e.g., SPECTRA® Fiber and SPECTRA® Guard, from Honeywell International, Inc., Morris Township, N.J., or DYNEEMA® from Royal DSM N.V., Heerlen, the Netherlands), polytetrafluoroethylene (PTFE), expanded PTFE (ePTFE), polyether ketone (PEK), polyether ether ketone (PEEK), poly ether ketone ketone (PEKK) (also poly aryl ether ketone ketone), nylon, polyether-block co-polyamide polymers (e.g., PEBAX® from ATOFINA, Paris, France), aliphatic polyether polyurethanes (e.g., TECOFLEX® from Thermedics Polymer Products, Wilmington, Mass.), polyvinyl chloride (PVC), polyurethane, thermoplastic, fluorinated ethylene propylene (FEP), absorbable or resorbable polymers such as polyglycolic acid (PGA), poly-L-glycolic acid (PLGA), polylactic acid (PLA), poly-L-lactic acid (PLLA), polycaprolactone (PCL), polyethyl acrylate (PEA), polydioxanone (PDS), and pseudo-polyamino tyrosine-based acids, extruded collagen, silicone, zinc, echogenic, radioactive, radiopaque materials, a biomaterial (e.g., cadaver tissue 154, collagen, allograft, autograft, xenograft, bone cement, morselized bone, osteogenic powder, beads of bone) any of the other materials listed herein or combinations thereof. Examples of radiopaque materials are barium sulfate, zinc oxide, titanium, stainless steel, nickel-titanium alloys, tantalum and gold.
[0085] Any or all elements of the measurement tool 2 and/or other devices or apparatuses described herein, can be, have, and/or be completely or partially coated with agents and/or a matrix a matrix for cell ingrowth or used with a fabric, for example a covering (not shown) that acts as a matrix for cell ingrowth. The matrix and/or fabric can be, for example, polyester (e.g., DACRON® from E. I. Du Pont de Nemours and Company, Wilmington, Del.), polypropylene, PTFE, ePTFE, nylon, extruded collagen, silicone or combinations thereof.
[0086] The measurement tool 2 and/or elements of the measurement tool 2 and/or other devices or apparatuses described herein and/or the fabric can be filled, coated, layered and/or otherwise made with and/or from cements, fillers, glues, and/or an agent delivery matrix known to one having ordinary skill in the art and/or a therapeutic and/or diagnostic agent. Any of these cements and/or fillers and/or glues can be osteogenic and osteoinductive growth factors.
[0087] Examples of such cements and/or fillers includes bone chips, demineralized bone matrix (DBM), calcium sulfate, coralline hydroxyapatite, biocoral, tricalcium phosphate, calcium phosphate, polymethyl methacrylate (PMMA), biodegradable ceramics, bioactive glasses, hyaluronic acid, lactoferrin, bone morphogenic proteins (BMPs) such as recombinant human bone morphogenetic proteins (rhBMPs), other materials described herein, or combinations thereof.
[0088] The agents within these matrices can include any agent disclosed herein or combinations thereof, including radioactive materials; radiopaque materials; cytogenic agents; cytotoxic agents; cytostatic agents; thrombogenic agents, for example polyurethane, cellulose acetate polymer mixed with bismuth trioxide, and ethylene vinyl alcohol; lubricious, hydrophilic materials; phosphor cholene; anti-inflammatory agents, for example non-steroidal anti-inflammatories (NSAIDs) such as cyclooxygenase-1 (COX-1) inhibitors (e.g., acetylsalicylic acid, for example ASPIRIN® from Bayer AG, Leverkusen, Germany; ibuprofen, for example ADVIL® from Wyeth, Collegeville, Pa.; indomethacin; mefenamic acid), COX-2 inhibitors (e.g., VIOXX® from Merck & Co., Inc., Whitehouse Station, N.J.; CELEBREX® from Pharmacia Corp., Peapack, N.J.; COX-1 inhibitors); immunosuppressive agents, for example Sirolimus (RAPAMUNE®, from Wyeth, Collegeville, Pa.), or matrix metalloproteinase (MMP) inhibitors (e.g., tetracycline and tetracycline derivatives) that act early within the pathways of an inflammatory response. Examples of other agents are provided in Walton et al, Inhibition of Prostoglandin E 2 Synthesis in Abdominal Aortic Aneurysms, Circulation, Jul. 6, 1999, 48-54; Tambiah et al, Provocation of Experimental Aortic Inflammation Mediators and Chlamydia Pneumoniae, Brit. J. Surgery 88 (7), 935-940; Franklin et al, Uptake of Tetracycline by Aortic Aneurysm Wall and Its Effect on Inflammation and Proteolysis, Brit. J. Surgery 86 (6), 771-775; Xu et al, Sp1 Increases Expression of Cyclooxygenase-2 in Hypoxic Vascular Endothelium, J. Biological Chemistry 275 (32) 24583-24589; and Pyo et al, Targeted Gene Disruption of Matrix Metalloproteinase-9 (Gelatinase B) Suppresses Development of Experimental Abdominal Aortic Aneurysms, J. Clinical Investigation 105 (11), 1641-1649 which are all incorporated by reference in their entireties.
Methods of Use
[0089] FIG. 38 a illustrates a section of tissue 154 that can have a tunnel defect 156 passing through the tissue 154 . The tunnel defect 156 can be substantially perpendicular to the face of the tissue 154 . For example, the tunnel defect 156 can be an atrial septal defect (ASD). FIG. 38 b illustrates that the tunnel defect 156 can be at a steep angle or substantially parallel to the face of the tissue 154 . For example, the tunnel defect 156 can be a patent foramen ovale (PFO).
[0090] FIG. 39 illustrates that the tunnel defect 156 can have a defect front face 162 and a defect back face (not shown). A defect front lip 160 can be defined by the perimeter of the defect front face 162 . A defect back lip 158 can be defined by the perimeter of the defect back face. The tunnel defect 156 can have a defect height 164 , a defect depth 166 and a defect width 168 .
[0091] FIG. 40 illustrates that a guidewire 170 can be deployed through the tunnel defect 156 . The guidewire 170 can be passed through the guide lumen 4 in the measurement tool 2 . The measurement tool 2 can be in a radially contracted (as shown) or radially expanded configuration. The measurement tool 2 can be translated, as shown by arrow, along the guidewire 170 . The measurement tool 2 can be translated to the tunnel defect 156 with or without the use of the guidewire 170 .
[0092] FIG. 41 illustrates that the measurement tool 2 can be translated into the tunnel defect 156 . The guidewire 170 can be left in place or removed. The location of the measurement tool 2 can be monitored by dead reckoning, and/or imaging, and/or tracking along the length of the guidewire 170 . The measurement tool 2 can be positioned so that the tunnel defect 156 is located adjacent to the catheter porous section 20 . The measurement tool 2 can be positioned so that the tunnel defect 156 is located substantially between the most distal wire distal anchor 14 and the most proximal wire proximal sheath.
[0093] FIG. 42 illustrates that the measurement tool 2 can be radially expanded. The measuring wires 100 in the wire radially constrained section 10 can be distally longitudinally translated, as shown by arrow 54 . The measuring wires 100 can translate radially (i.e., away from the longitudinal axis 16 ), as shown by arrows 52 . The measuring wires 100 can radially distend the tunnel defect 156 , for example causing the tunnel defect 156 to widen (shown by arrows similar to arrows 52 ) and shorten or otherwise contract in height, as shown by arrows 172 . The measuring wires 100 can radially distend the tunnel defect 156 , for example, until the tunnel defect 156 will no longer distend without structurally damaging the tunnel defect 156 .
[0094] FIG. 43 illustrates that the measuring wires 100 can be radially translated beyond the extent that the tunnel defect 156 can be distended without structural damage. The measuring wires 100 can deform around the front and back defect lips. Portions of the measuring wires 100 can configure into wire overdeployment sections 176 proximal and distal to the tunnel defect 156 . The wire overdeployment sections 176 , or markers 102 thereon, can be imaged, for example using x-rays (e.g., radiography, fluoroscopy), ultrasound, or magnetic resonance imaging (MRI). The wire overdeployment sections 176 can illustrate the defect width 168 (i.e., the length between the wire deployment sections) when the defect is in a fully distended configuration.
[0095] FIG. 44 illustrates that the measurement tool 2 can have no catheter porous section 20 , for example, when the measurement tool 2 is used for the measurement method as shown in FIG. 43 . The methods of use shown in FIGS. 43 and 44 can, for example, measure the defect depth 166 and/or the defect height 164 .
[0096] FIG. 45 illustrates that contrast fluid or particles can be deployed into the fluid lumen 36 of the catheter 26 , for example, when tunnel defect 156 is in a fully distended configuration. The contrast fluid can be radiopaque, echogenic, visible contrast (e.g., dyes, inks), any other material disclosed herein, or combinations thereof. The fluid pressure of the contrast fluid or particles can be increased. The contrast fluid or particles can emit, as shown by arrows 180 , through the catheter porous section 20 . The contrast fluid or particles outside of the catheter 26 can configure into a marker cloud 178 . The marker cloud 178 can move into position around the tissue 154 . The marker cloud 178 can illustrate the defect dimensions (i.e., visible with imaging systems known to those having ordinary skill in the art, including x-ray, CAT, MRI, fiber optic camera, ultrasound/sonogram) when the defect is in a fully distended configuration.
[0097] A drug can be deployed from the catheter porous section 20 , for example, similar to the method of deploying the contrast fluid.
[0098] FIG. 46 illustrates that a proximal force, as shown by arrows, can be applied to the distal collar 122 . For example, the retraction leader 148 can be pulled proximally.
[0099] FIG. 47 illustrates that the distal collar 122 can translate proximally, as shown by arrows 52 . The measuring wires 100 can expand radially away from the central longitudinal axis 16 of the measurement tool 2 . The wires can bend radially outward at the wire distal hinge 144 and the wire proximal hinges 142 . The wires can bend radially inward at the wire first hinge 138 and wire second hinge 140 . The wires can also form a curved or splined configuration (e.g., similar to the configuration shown in FIG. 6 , inter alia) instead of or in addition to the hinges 106 .
[0100] The measuring wires 100 can be resiliently biased to the radially contracted configuration. When the proximal force is no longer applied to the distal collar 122 , the measuring wires 100 can straighten and distally force the distal collar 122 to translate to the position shown in FIG. 46 .
[0101] The measurement wires can be deformable. The retraction leader 148 can be rigid. For example, to radially contract the measuring wires 100 , the retraction leader 148 can distally force the distal collar 122 to translate to the position shown in FIG. 46 . The measuring wires 100 can deform to the position shown in FIG. 46 .
[0102] FIG. 48 illustrates that the wire assembly 118 can be radially constrained by the catheter sheath 152 . The catheter sheath 152 can radially encircle the measuring wires 100 and/or the entire wire assembly 118 . The catheter sheath 152 can longitudinally encompass the measuring wires 100 and/or the entire wire assembly 118 . A distal force, as shown by arrows, can be applied to the catheter sheath 152 .
[0103] FIG. 49 illustrates that the measuring wires 100 can be resiliently biased to radially expand away from the center longitudinal axis 16 of the measurement tool 2 . When the catheter sheath 152 is retracted distal to the measuring wires 100 , the measuring wires 100 can radially expand, as shown by arrows. The distal collar 122 can proximally translate, as shown by arrows.
[0104] The catheter sheath 152 can be rigid. The catheter sheath 152 can be distally translated, for example to radially contract the measuring wires 100 . The catheter sheath 152 can radially contract the measuring wires 100 as the catheter sheath 152 substantially underformably slides distally over the measuring wires 100 .
[0105] A distension device size can be determined as described, supra. The measurement tool 2 can be radially contracted and removed from the tunnel defect 156 , or the coupler 96 and/or the elements of the measurement tool 2 proximal to the coupler 96 can be detached from the remainder of the measurement tool 2 and removed. If the entire measurement tool 2 is removed from the tunnel defect 156 , a distension device can be selected that has a size that substantially matches (e.g., is equivalent when the distension device is in a substantially or completely radially expanded configuration) the size of the distended tunnel defect 156 . The distension device can be deployed to the tunnel defect 156 , for example along the guidewire 170 . The guidewire 170 can be removed. The distension device can be, for example, a filter, stopper, plug, any distending device described in U.S. patent application Ser. No. 10/847,909, filed 19 May 2004; Ser. No. 11/184,069, filed 19 Jul. 2005; and Ser. No. 11/323,640, filed 3 Jan. 2006, all of which are incorporated by reference herein in their entireties, or any combinations thereof.
[0106] Any elements described herein as singular can be pluralized (i.e., anything described as “one” can be more than one). Any species element of a genus element can have the characteristics or elements of any other species element of that genus. The above-described configurations, elements or complete assemblies and methods and their elements for carrying out the invention, and variations of aspects of the invention can be combined and modified with each other in any combination.
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A measuring device for measuring tunnel defects in tissue is disclosed. The measuring device can size the defect to aid future deployment of a tissue distension device. Exemplary tunnel defects are atrial septal defects, patent foramen ovales, left atrial appendages, mitral valve prolapse, and aortic valve defects. Methods for using the same are disclosed.
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FIELD OF THE INVENTION
The present invention relates to a method and/or architecture for image processing generally and, more particularly, to a high performance warp correction in two-dimensional images.
BACKGROUND OF THE INVENTION
Camera image processing uses a warp correction system to correct for warping in an input image. Warp correction is a mapping of a pixel in an output image to a pixel in the input image. The mapping is defined by a two-dimensional (2D) warp field that depends on the optical characteristics of the lens and a zoom factor. Conventionally, the warp field is computed for a camera design and stored in 2D tables of an actual camera. Since the table entry spacing covers more than a single pixel, 2D bilinear interpolation is used to calculate the warp field at the missing pixels. The warp field spans hundreds of lines across the input image and so a large buffer space is used to hold sufficient input image data. Management of the buffer is based on a minimum warp field calculated across a next pixel line. Conventional approaches hold the warp field in either a 5-ported memory or 5 memory banks to achieve a single pixel per clock performance.
It would be desirable to achieve the single pixel per clock performance with a single-ported memory.
SUMMARY OF THE INVENTION
The present invention concerns an apparatus generally having a first memory, a second memory and a circuit. The first memory may be configured to store a warp table. The warp table is generally accessed through a single data port of the first memory. The second memory may be configured to buffer an input image. The input image may have a plurality of input pixels arranged in two dimensions. The circuit may be configured to generate an output image by a warp correction of an input image. The warp correction may be defined by the warp table. The output image may include a plurality of output pixels. At least one of the output pixels maybe generated during each clock cycle of the circuit.
The objects, features and advantages of the present invention include providing a high performance warp correction in 2-dimensional images that may (i) achieve a single output pixel per clock performance, (ii) store a warp field in a single-port memory, (iii) read fewer warp table entries than conventional techniques for interpolation calculations, (iv) compute interpolation parameters in advance of warping an input image, (v) utilize pipelining and chaining of the interpolation parameters, (vi) compute warp fields at every pixel using the adders instead of multipliers and/or (vii) achieve a small hardware cost while maintaining high performance compared with conventional designs.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects, features and advantages of the present invention will be apparent from the following detailed description and the appended claims and drawings in which:
FIG. 1 is a block diagram of an example method for warp correction in two-dimensional images;
FIG. 2 is a diagram of an example two-dimensional image;
FIG. 3 is a diagram of a rectangular grid superimposed on an output image;
FIG. 4 is a block diagram of an apparatus in accordance with a preferred embodiment of the present invention;
FIG. 5 is a flow diagram of an example method for calculating a minimum warp field;
FIG. 6 is a flow diagram of an example method for calculating interpolation parameters;
FIG. 7 is a diagram of the interpolation parameters and a chaining operation when crossing a grid boundary;
FIG. 8 is a flow diagram of an example method for calculating a motion vector and fetching an input tile; and
FIG. 9 is a flow diagram of an example method for calculating the output pixels.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Some embodiments of the present invention may concern an apparatus having a single-ported memory, multiple (e.g., 4) stages of a process pipeline, an arbitration logic, an input tile buffer and an output tile buffer. The single-ported memory generally holds a two-dimensional (2D) warp field. The input tile buffer may be configured to hold multiple input tiles. An on-chip memory or an off-chip memory may store a partial image. An initial stage of a circuit may be configured to compute a minimum warp field across a pixel line. The next stage of the circuit may be configured to compute a warp field at specific points. Another stage of the circuit is generally configured to fetch the input tiles from the image buffer. A subsequent stage of the circuit may be configured to calculate a warp field at every output pixel point and compute output pixels from the fetched input tile. All stages of the circuit generally work in a pipelined fashion to achieve a high performance circuit. Access to the warp table may be arbitrated between the two front-end stages by the arbitration logic. A later of the front-end stages generally reads several (e.g., 4) warp table entries where an initial output tile is being generated. The later stage may read a few (e.g., 2) warp table entries where other output tiles are being generated. Since grid spacing in the warp field usually covers many pixels, the initial stage may utilize several clock cycles to access the appropriate warp table entries.
Referring to FIG. 1 , a block diagram of an example method 100 for warp correction in 2D images is shown. The method (or process) 100 generally comprises a step (or block) 102 , a step (or block) 104 , a step (or block) 106 , a step (or block) 108 . The steps 102 to 108 may be implemented in hardware, software, firmware or any combination thereof in an apparatus.
In the step 102 , one or more portions of an input image within a signal (e.g., IN) may be buffered in an image buffer. From the image buffer, a warp correction along a horizontal direction may be performed on an input image portion in the step 104 . Operations of the step 104 may generate an intermediate image portion. The step 104 may be implemented in a unit (or circuit) of the apparatus referred to as a horizontal warp correction unit. In the step 106 , the intermediate image portion may be buffered in another image buffer. In some embodiments, both image buffers may reside within a common memory device in different addressable regions. In other embodiments, each image buffer may reside in a separate memory. The step 108 generally performs another warp correction in a vertical direction on the intermediate image portion to generate a corresponding portion of an output image in a signal (e.g., OUT). The step 108 may be implemented by a unit (or circuit) of the apparatus referred to as a vertical warp correction unit. In some embodiments, the horizontal warp correction unit and the vertical warp correction unit may be the same unit within the apparatus. The horizontal warp correction unit generally works on horizontal components of a warp field and thus achieves warp correction in the horizontal direction. The vertical warp correction unit may work on vertical components of the warp field and thus achieve warp correction in the vertical direction.
Referring to FIG. 2 , a diagram of an example 2D image 120 is shown. The image (or region) 120 may have a height (e.g., H) and a width (e.g., W). The image 120 may represent an input image or an output image. The height H may be a distance between (i) an upper-left corner (e.g., (X,Y)=(0,0)) and a lower-left corner (e.g., (X,Y)=(0,H) of the image 120 and/or (ii) an upper-right corner (e.g., (X,Y)=(W,0)) and a lower-right corner (e.g., (X,Y)=(W,H) of the image 120 . The width W may be a distance between the upper-left corner and the upper-right corner of the image 120 and/or the lower-left corner and the lower-right corner of the image 120 .
The image 120 is generally divisible into multiple tiles (or subregion) 122 a - 122 n . Each tile 122 a - 122 n may be a rectangle. Tiles 122 a - 122 n in an input image may be referred to as input tiles. The tiles 122 a - 122 n in the intermediate image may be referred to as intermediate tiles. Tiles 122 a - 122 n in an output image may be referred to as output tiles.
The tiles 122 a - 122 n may be arranged in one or more tile rows 124 a - 124 k (only rows 124 c and 124 f are shown for clarity). Each input tile 122 a - 122 n may comprise a 2D array of input pixels. Each intermediate tile 122 a - 122 n may comprise a 2D array of intermediate pixels. Each output tile 122 a - 122 n may comprise a 2D array of output pixels. By way of example, a particular tile (e.g., 122 g ) may be defined by four corners (e.g., A1, B1, C1 and D1).
The warp correction units generally fetch fixed-size tiles from the corresponding image buffers (e.g., image buffer 102 , image buffer 106 ). The warp correction units may generate fixed-size intermediate tiles and fixed-size output tiles. For example, the vertical warp correction unit may (i) fetch intermediate tiles having a size of 64 rows by 8 columns and (ii) generate output tiles having a size of 16 rows by 8 columns. Furthermore, the horizontal warp correction unit generally (i) fetches input tiles having a size of 1 row by 6 columns and (ii) generate intermediate tiles having a size of 1 row by 1 column (e.g., a single intermediate pixel).
Referring to FIG. 3 , a diagram of a rectangular grid 126 superimposed on an output image (e.g., 120) is shown. The row 124 f of output tiles is also shown. The output tiles may be generated in a raster scan order.
A grid field is generally specified at the crossing points of the grid 126 and stored in a single-port memory. The single-port memory may have only a single x-bit wide data port. An address to the single-port memory is generally a number formed by a concatenating a grid row value (e.g., GRIDROW) and a grid column value (e.g., GRIDCOL) such that the address accesses data at {GRIDROW, GRIDCOL}.
The value GRIDROW value may be stored in an n-bit register. A value of 2^n is generally designed to be greater than or equal to a maximum number of grid rows in the grid 126 . The value GRIDCOL may be stored in an m-bit register. A value 2^m is generally designed to be greater than or equal to a maximum number of grid columns in the grid 126 . A grid spacing value (e.g., GHS) of the grid 126 may refer to a grid spacing in the horizontal direction. A grid spacing value (e.g., GVS) of the grid 126 generally refers to a grid spacing in the vertical direction. The value GHS may be an integer fraction of the width of the output tiles. The value GVS may be another integer fraction of the height of the output tiles.
Referring to FIG. 4 , a block diagram of an apparatus 130 is shown in accordance with a preferred embodiment of the present invention. The apparatus (or device) 130 generally comprises a circuit (or module) 132 , a circuit (or module) 134 and a circuit (or module) 136 . The signal IN may be received by the circuit 136 . The signal OUT may be generated and presented by the circuit 136 . A clock signal (e.g., CLK) may be received by the circuit 132 . The circuits 132 - 136 may be implemented in hardware, software, firmware or any combination thereof in an apparatus. In some embodiments, the apparatus 130 may be a digital video camera, a digital still camera or a hybrid digital video/still camera.
The circuit 132 may implement a pipelined processor circuit. The circuit 132 is generally operational to generate an output image by a warp correction of an input image. Warp correction may be defined by multiple values stored in a warp table. The warp correction may include a directional warp correction along an initial direction (e.g., horizontal direction) of the input image to create an intermediate image. The warp correction may also include another directional warp correction along a different direction (e.g., vertical direction) of the intermediate image to create the output image.
The circuit 134 may implement a single-port memory circuit. The circuit 134 may be operational to store the warp table 140 used by the circuit 132 . The circuit 134 generally has a single x-bit wide data port, a single y-bit wide address port and corresponding command and control interfaces. In some embodiments, the circuit 134 may implement a nonvolatile memory. In other embodiments, the circuit 134 may implement a volatile memory with the warp table 140 being loaded at power up and/or reset. In still other embodiments, the circuit 134 may implement a multi-port memory with a single port being utilized in a design of the circuit 130 . The circuit 134 may be fabricated either on (in) a same die as the circuit 132 or on (in) a separate die from the circuit 132 .
The circuit 136 may implement one or more memory circuits. The circuit 136 may be operational to establish an input tile buffer 142 and an output tile buffer 144 in different addressable areas. In some embodiments, the circuit 136 may comprise two or more memories with the buffer 142 residing in one memory circuit and the buffer 144 residing in another memory circuit. The circuit 136 may be fabricated either on (in) a same die as the circuit 132 or on (in) a separate die from the circuit 132 . The circuit 136 may also be fabricated either on (in) a same die as the circuit 134 or on (in) a separate die from the circuit 134 .
The circuit 132 generally comprises a circuit (or module) 146 , a circuit (or module) 148 , a circuit (or module) 150 , a circuit (or module) 152 and a circuit (or module) 154 . The circuits 146 and 148 may bidirectionally communicate with the circuit 154 . The circuit 154 may bidirectionally communicate with the circuit 134 to access the warp table 140 . The circuit 150 may bidirectionally communicate with the circuit 136 to access the buffer 142 . The circuit 152 may bidirectionally communicate with the circuit 136 to access the buffer 142 and the buffer 144 . The circuits 146 - 154 are generally arranged in a pipeline fashion such that each circuit 146 - 152 is in bidirectional communication with a neighboring circuit 146 - 152 . In some embodiments, additional pipelined circuits may be included in the circuit 132 at the output-end of the circuit 152 .
The circuit 146 may implement a stage of the pipeline. The circuit 146 is generally operational to fetch a portion of the warp table 140 from the circuit 134 corresponding to a current tile row being analyzed. The circuit 146 may also generate a minimum warp field across the current tile row in the output image utilizing the warp table 140 . Generally, the circuit 146 may calculate warp fields at the top-left point of the tile row using one-dimensional interpolation. The one-dimensional interpolation may be repeated at incremental points along the top line at every vertical grid crossing. The above approach may result in reading at most two table entries from the warp table 140 per grid spacing. The minimum warp field may be passed to the circuit 148 .
The circuit 148 may implement another stage of the pipeline. The circuit 148 is generally operational to fetch a portion of the warp table 140 from the circuit 134 corresponding to the current tile row. The circuit 148 may also generate multiple interpolation parameters of the tile row based on the warp table 140 . The interpolation parameters and the minimum warp field may be passed to the circuit 150 .
The circuit 150 may implement another stage of the pipeline. The circuit 150 is generally operational to fetch an input tile of an input image into the buffer 142 . The fetching may be based on the interpolation parameters generated by the circuit 148 and the minimum warp field generated by the circuit 146 . The circuit 150 is also operational to generate multiple phasing parameters corresponding to the input tile. The interpolation parameters, minimum warp field and phasing parameters may be transferred to the circuit 152 .
The circuit 152 may implement another stage of the pipeline. The circuit 152 is generally operational to fetch several neighboring input pixels from the buffer 142 . The circuit 152 may generate output tiles in the tile row of the output image based on the interpolation parameters, the phasing parameters and the input tile. The output tiles may be written to the buffer 144 for subsequent use in other parts of the apparatus 130 .
The circuit 154 may implement an arbitrator circuit. The circuit 154 is generally operational to perform arbitration between the circuits 146 and 148 for access to the circuit 134 and the warp table 140 therein. In some embodiments, the circuit 154 may be formed external to the circuit 132 .
When information generated by a particular circuit 146 - 152 is ready, the particular circuit 146 - 152 may assert a signal (e.g., VALID) to the next neighboring circuit 148 - 152 in the pipeline. A signal (e.g., NEXT) may be generated by the next neighboring circuit 148 - 152 when ready for more information, the signal NEXT may be transferred back to the previous neighboring circuit 146 - 152 . The information may be transferred from a one circuit (e.g., circuit 148 ) to another circuit (e.g., circuit 150 ) when both the signal VALID and the signal NEXT between the neighboring circuits are asserted in the same clock cycle of the signal CLK. Once the information has been transferred, the information may be latched locally in the receiving circuit 148 - 152 and used in the next computations of the stage.
The circuits 146 and 148 may arbitrate for access to warp table 140 . The circuit 154 may perform the arbitration. In some embodiments, the arbitration scheme may be a priority arbitration with a highest priority to the circuit 148 . If the circuit 148 is trying to access the circuit 134 , the circuit 148 is generally granted access in the same cycle. If the circuit 148 is not requesting access and the circuit 146 is requesting access, access may be granted to the circuit 146 . Accesses to the warp table 140 from the circuit 146 and the circuit 148 may be time multiplexed with circuit 148 having higher priority. Other arbitration schemes may be implemented to meet the criteria of a particular application.
The following definitions are generally used in the descriptions below:
OUT_TILE_HEIGHT: Height of the output tile in units of pixels;
OUT_TILE_WIDTH: Width of the output tile in units of pixels;
GHS: Horizontal grid spacing in units of pixels;
GVS: Vertical grid spacing in units of pixels;
GVS_: GVS/OUT_TILE_HEIGHT;
FILTERTAPS: Number of taps of a Finite Impulse Response (FIR) filter used for generating the output pixels.
Referring to FIG. 5 , a flow diagram of an example method 160 for calculating the minimum warp field is shown. The method (or process) 160 may be implemented by the circuit 146 . The method 160 generally comprises a step (or block) 162 , a step (or block) 164 , a step (or block) 166 , a step (or block) 168 , a step (or block) 170 , a step (or block) 172 , a step (or block) 174 , a step (or block) 176 , a step (or block) 178 and a step (or block) 180 . The steps 162 to 180 may be implemented in hardware, software, firmware or any combination thereof in an apparatus.
The circuit 146 generally comprises multiple internal registers. A register (e.g., OUT_TILE_ROW) may point to a current row of a current output tile. Another register (e.g., GRIDCOL) may point to a current grid column. Another register (e.g., GA) may store a warp value read from the warp table 140 . A register (e.g., GC) may store another warp value read from the warp table 140 . A register (e.g., MINIMUM_WARP) may store the minimum warp field value. The circuit 146 may calculate the minimum warp field value across a next output tile row and transfer the minimum warp field value to the circuit 148 . The computation generally occurs once for each output tile row.
On power up and/or reset, (i) the value GRIDCOL may be initialized (e.g., GRIDCOL=0), (ii) the value OUT_TILE_ROW may be initialized (e.g., OUT_TILE_ROW=1) and (iii) the circuit 146 may wait for a start of frame in the step 162 . The register GRIDCOL and the register OUT_TILE_ROW may be used as local counters. The start of frame is generally a software mechanism used to start hardware processing. In the step 164 , the circuit 146 may (i) compute GRIDROW=integer (OUT_TILE_ROW/GVS_) and (ii) clear the value MINIMUM_WARP (e.g., MINIMUM_WARP=0).
In the step 166 , the circuit 146 may (i) form an address by concatenating the value GRIDROW and the value GRIDCOL (e.g., ADDRESS={GRIDROW, GRIDCOL}), (ii) read the warp table 140 at the address and (iii) latch the read data into the register GA. The step 166 may include (i) generating another address by concatenating the values GRIDROW+1 and GRIDCOL (e.g., ADDRESS={GRIDROW+1,GRIDCOL}), (ii) reading the warp table 140 at the address and (iii) latching the read data into the register GC. In the step 168 , the circuit 146 generally computes a temporary value (e.g., TEMP) as TEMP=GA+(GC−GA)*FRACTION, where FRACTION=(OUT_TILE_ROW % GVS_)/GVS_. The function x % y may be a modulus function that returns the remainder of x divided by y. The circuit 146 may compute MINIMUM_WARP=min(MINIMUM_WARP, TEMP) in the step 170 , where min(a,b)=if(a<b)?a:b. The function x?y:z generally means that if x is true, return the value y, else return the value z.
A check may be performed in the step 172 to determine if the value GRIDCOL is that of the rightmost column of the output image. If true (e.g., the YES branch of step 172 ), (i) the signal VALID may be asserted in the step 174 , (ii) the value MINIMUM_WARP may be presented to the circuit 148 and (iii) the circuit 146 waits for the signal NEXT to be activated by the circuit 148 . If false (e.g., the NO branch of step 172 ), the GRIDCOL counter may be incremented in the step 176 and the method 160 returns to the step 166 .
Once the signal NEXT has been asserted by the circuit 148 , a check may be performed in the step 178 to determine if the value OUT_TILE_ROW is that of the last row of the output image. If the check is true (e.g., the YES branch of step 178 ), the method 160 may return to the step 162 and wait for the next start of frame. If false (e.g., the NO branch of step 178 ), the value GRIDCOL may be cleared (e.g., GRIDCOL=0) and the value OUT_TILE_ROW may be incremented in the step 180 . The method 160 generally returns from the step 180 to the step 164 .
Referring to FIG. 6 , a flow diagram of an example method 190 for calculating the interpolation parameters is shown. The method (or process) 190 may be implemented by the circuit 148 . The method 190 generally comprises a step (or block) 192 , a step (or block) 194 , a step (or block) 196 , a step (or block) 198 , a step (or block) 200 , a step (or block) 202 , a step (or block) 204 , a step (or block) 206 , a step (or block) 208 , a step (or block) 210 , a step (or block) 212 and a step (or block) 214 . The steps 192 to 214 may be implemented in hardware, software, firmware or any combination thereof in an apparatus.
The circuit 148 generally comprises multiple internal registers similar to the internal registers of the circuit 146 . The register OUT_TILE_ROW may point to a current row of a current output tile. The register GRIDCOL may point to a current grid column. The register GA may store a warp value read from the warp table 140 . The register GC may store another warp value read from the warp table 140 . The register MINIMUM_WARP may store the minimum warp field value. The circuit 148 may calculate value for multiple interpolation parameters and transfer the values to the circuit 150 .
Referring to FIG. 7 , a diagram 218 of the interpolation parameters and the chaining operation when crossing a grid boundary (e.g., going from grid X to grid (X+1)) is shown. The circuit 148 is generally operational to compute the interpolation parameters. When a grid boundary is crossed, the circuit 148 may chain the interpolation parameters. The circuit 148 may(i) transfer a N_START_POINT parameter (e.g., warp field at top right corner) into a START_POINT parameter (e.g., warp field at top left corner), (ii) transfer a N_END_POINT parameter (e.g., warp field at bottom right corner) into an END_POINT parameter (e.g., warp field at bottom left corner) and (iii) compute the N_START_POINT parameter and the N_END_POINT parameter for the next grid. The interpolation parameters may include, but are not limited to (i) the START_POINT parameter, (ii) the END_POINT parameter, (iii) the N_START_POINT parameter, (iv) the N_END_POINT parameter, (v) a HORZ_S_INC parameter (e.g., increment along top pixel line) and (vi) a HORZ_E_INC parameter (e.g., increment along bottom pixel line) as illustrated.
Returning to FIG. 6 , on power up and/or reset, the circuit 148 may (i) initialize the value GRIDCOL (e.g., GRIDCOL=0) and (ii) initialize the OUT_TILE_ROW (e.g., OUT_TILE_ROW=0) in the step 192 . The register GRIDCOL and the register OUT_TILE_ROW may be used as local counters. Upon receiving the start of frame, the circuit 148 may compute the value GRIDROW as GRIDROW=integer(OUT_TILE_ROW/GVS_) and wait for the signal VALID to be asserted by the circuit 146 in the step 194 .
When the signal VALID is asserted by the circuit 146 , the circuit 148 may (i) latch the value MINIMUM_WARP in a local register in the step 196 , (ii) generate an address by concatenation of GRIDROW and GRIDCOL (e.g., ADDRESS={GRIDROW,GRIDCOL}), (iii) read the warp table 140 from the address and (iv) latch the read data into the register GA. In the step 196 may also include (i) forming another address by concatenation of the values GRIDROW+1 and GRIDCOL (e.g., ADDRESS={GRIDROW+1,GRIDCOL}), (ii) read data from the warp table 140 from the address and (iii) latch the read data into register GC.
In the step 198 , the circuit 148 may compute (i) START_POINT=GA+(GC−GA)*FRACTION, where FRACTION=(OUT_TILE_ROW % GVS_)/GVS_, (ii) END_POINT=START_POINT+(GC−GA)*FRACTION where FRACTION=1/GVS_and (iii) increment the value GRIDCOL (e.g., GRIDCOL=+1). The circuit 148 may use the step 200 to (i) form an address by concatenating the values GRIDROW and GRIDCOL (e.g., ADDRESS={GRIDROW,GRIDCOL}), (ii) read the warp table 140 from the address and (iii) latch the read the read data into register GA. The step 200 may also include (i) forming another address by concatenating the values GRIDROW+1 and GRIDCOL (e.g., ADDRESS={GRIDROW+1,GRIDCOL}), (ii) read the warp table 140 from address and (iii) latch the read data into register GC.
In the step 202 , the circuit 148 may compute (i) N_START_POINT=GA+(GC−GA)*FRACTION, where FRACTION=(OUT_TILE_ROW % GVS_)/GVS_and (ii) N_END_POINT=N_START_POINT+(GC−GA)*FRACTION, where FRACTION=1/GVS_. The circuit 148 may compute (i) an increment along the top horizontal line (e.g., HORZ_S_INC=(N_START_POINT−START_POINT)/GHS, where the value GHS is horizontal grid spacing in units of pixels) in the step 204 and (ii) an increment along the bottom horizontal line (e.g., HORZ_E_INC=(N_END_POINT−END_POINT)/GHS.
In the step 206 , the signal VALID may be asserted to the circuit 150 and the circuit 148 may wait for the signal NEXT to be asserted by the circuit 150 . Once the signal NEXT has been asserted by the circuit 150 , the circuit 148 may check to determine if the value GRIDCOL is that of the rightmost column of the image in the step 208 . If true (e.g., the YES branch of step 208 ), the circuit 148 may check in the step 210 to determine if the value OUT_TILE_ROW is that of the last row. If the check in the step 208 is false (e.g., the NO branch of step 208 ), the circuit 148 may (i) move the value N_START_POINT into the value START_POINT, (ii) move the value N_END_POINT into the value END_POINT, (iii) increment the value GRIDCOL in the step 212 and proceed to the step 200 .
If the value OUT_TILE_ROW is that of the last row of the image (e.g., the YES branch of step 210 ), the process may return to step 192 and wait for the next start of frame. If the check is false (e.g., the NO branch of step 210 ), the circuit 148 may (i) increment the value OUT_TILE_ROW by one, (ii) clear the value GRIDCOL (e.g., GRIDCOL=0) and return to the step 194 .
Referring to FIG. 8 , a flow diagram of an example method 220 for calculating a motion vector and fetching an input tile is shown. The method (or process) 220 may be implemented by the circuit 150 . The method 220 generally comprises a step (or block) 222 , a step (or block) 224 , a step (or block) 226 , a step (or block) 227 , a step (or block) 228 , a step (or block) 230 , a step (or block) 232 , a step (or block) 234 , a step (or block) 236 , a step (or block) 238 , a step (or block) 240 and a step (or block) 242 . The steps 222 to 242 may be implemented in hardware, software, firmware or any combination thereof in an apparatus.
The circuit 150 may be operational to fetch input tiles into the buffer 142 . Once a complete input tile is in the buffers local to the circuit 150 , the signal VALID may be asserted to the circuit 152 . The circuit 150 generally comprises multiple internal registers. A pair of registers (e.g., A and B) may be used to store intermediate calculated values. A register (e.g., CURRENT_PHASE) may store a pointer into the input picture. For an output pixel line N, a value of CURRENT_PHASE may be N*PHASE_INC. A register (e.g., SBASE) may store an address of the initial row stored in the image buffer 102 , image buffer 106 . The address may refer to the input picture. An address=0 may be an initial row of the input picture. The register MINIMUM_WARP may store the value of the minimum warp field. A register (e.g., ZERO_POINT) may store an address of an initial row of an input tile in the buffer 142 . A register (e.g., MV) may store an offset address into the image buffer 102 , image buffer 106 . MV=(row=0, column=0) generally means an initial row and an initial column in the image buffer 102 , image buffer 106 . A register (e.g., OUT_TILE_WIDTH) may store the width of the output tiles. The circuit 150 may calculate values for multiple phasing parameters and transfer the phasing parameter values, the interpolation values and the value MINIMUM_WARP to the circuit 152 . The phasing parameters may include, but are not limited to, the value CURRENT_PHASE and the value ZERO_POINT. The values in the registers CURRENT_PHASE and SBASE may be used to compute the value in the register MV, which is an address into the image buffer 102 , image buffer 106 . The values in the registers CURRENT_PHASE and ZERO_POINT are generally used to compute the address into the buffer 142 .
On power up and/or reset, the circuit 150 may (i) clear the register SBASE (e.g., SBASE=0), the register CURRENT_PHASE (e.g., CURRENT_PHASE=0), the register MINY (e.g., MINY=0) and the register OUT_TILE_COL (e.g., OUT_TILE_COL=0) in the step 222 . Upon receipt of the start of frame, the circuit 150 may wait for the circuit 148 to assert the signal VALID in the step 224 .
Once the signal VALID has been asserted by the circuit 148 , the circuit 150 may latch the values START_POINT, END_POINT, HORZ_S_INC, HORZ_E_INC and MINIMUM_WARP in the step 226 as received from the circuit 148 . In step 227 , the circuit 150 may compute a motion vector (e.g., MV) as:
1. B=A+(OUT_TILE_WIDTH−1)*HORZ_S_INC
2. ZERO_POINT=CURRENT_PHASE+min(A, B)+1−FILTERTAPS/2
3. MV=ZERO_POINT-SBASE
A check may be performed in the step 228 to determine if space is available in the buffer 142 to hold a complete new input tile. If space is available (e.g., the YES branch of step 218 ), the circuit may fetch the new input tile into the buffer 142 in the step 230 from an ADDRESS (X,Y)=(OUT_TILE_COL,MV) of the image buffer 102 , image buffer 106 . If insufficient space is available (e.g., the NO branch of step 228 ), the circuit 150 may wait in the step 232 for space to become available, then fetch the new input tile in the step 230 .
A check may be performed in the step 234 to determine if a grid boundary crossing is in progress. If the condition is true (e.g., the YES branch of step 234 ), another check may be made in the step 236 . If the condition is false (e.g., the NO branch of step 234 ), the circuit 150 may calculate A=+OUT_TILE_WIDTH*HORZ_S_INC in the step 238 and return to the step 227 .
The step 236 may determine if the right edge of the image has been reached. If false (e.g., the NO branch of step 236 ), the method 220 may proceed to the step 242 . If true (e.g., the YES branch of step 236 ), the circuit 150 may calculate CURRENT_PHASE=+PHASE_INC*OUT_TILE_HEIGHT in the step 240 , where PHASE_INC may be programmable from (0,1]. When the value PHASE_INC is programmed less than 1, an up-sampling may be achieved as well as warping. If the value PHASE_INC is programmed with 1, a warping may be achieved without up-sampling. The step 240 may also set SBASE=integer(CURRENT_PHASE+MINIMUM_WARP−FILTERTAPS/2+1). Thereafter, the method 220 may proceed to the step 242 .
A check may be made in the step 242 to determine if an end of frame has been reached. If the end of frame has been reached (e.g., the YES branch of step 242 ), the method 220 may return to step 222 and wait for a next start of frame. If no end of frame has been reached (e.g., the No branch of step 242 ), the method 220 may return to the step 224 and wait for the circuit 148 to assert the signal VALID.
Referring to FIG. 9 , a flow diagram of an example method 250 for calculating the output pixels is shown. The method (or process) 250 may be implemented by the circuit 152 . The method 250 generally comprises a step (or block) 252 , a step (or block) 254 , a step (or block) 256 , a step (or block) 258 , a step (or block) 260 , a step (or block) 262 , a step (or block) 264 , a step (or block) 266 and a step (or block) 268 . The steps 252 to 268 may be implemented in hardware, software, firmware or any combination thereof in an apparatus.
The circuit 152 may be operational to fetch pixels from the buffer 142 , generate the output pixels and store the output pixels in the buffer 144 . Generation of the output tiles may be performed in inverse raster scan order. Once a complete output tile is written to the buffer 144 , the output tile may be sent to either a next camera block in the pipeline of the circuit 132 and/or stored to an external memory for display/modification later.
On power up and/or reset, the circuit 152 may clear the local registers in the step 252 and wait for the signal VALID to be asserted by the circuit 150 . Once the signal VALID is asserted, the circuit 152 may (i) latch into the local registers the values CURRENT_PHASE, ZERO_POINT, END_POINT, START_POINT, HORZ_S_INC and HORZ_E_INC as received from the circuit 150 and (ii) initialize a column counter (e.g., COLUMN=0) in the step 254 . In the step 256 , the circuit 152 may (i) compute a vertical increment (e.g., VERTICAL_INCREMENT) as VERTICAL_INCREMENT=END_POINT−START_POINT, (ii) compute PHASE=CURRENT_PHASE (e.g., the CURRENT_PHASE received from the circuit 150 ) and (iii) initialize a row counter (e.g., ROW=0). In the step 258 , the circuit 152 may fetch input pixels from the buffer 142 starting from an ADDRESS=integer(PHASE−FILTERTAPS/2−1)−ZERO_POINT. The number of pixels fetched generally depends upon the filter values (e.g., FILTERTAPS) of the FIR filter. The step 258 may include (i) applying the FIR filtering on the fetched input pixels to generate an output pixel at a point (ROW,COLUMN) in the output tile and (ii) computing PHASE=+(PHASE_INC+VERTICAL_INCREMENT).
A check may be performed by the circuit 152 in the step 260 to determine if the counter ROW is less than the value OUT_TILE_HEIGHT. If counter ROW is less (e.g., the NO branch of step 260 ), the counter ROW may be incremented in the step 262 and the method 250 returns to the step 258 to calculate the next output pixel. Once the counter ROW reaches the value OUT_TILE_HEIGHT (e.g., the NO branch of step 260 ), the counter COLUMN may be incremented in the step 264 .
A check may be performed in the step 266 to determine if the counter COLUMN is less than the value OUT_TILE_WIDTH. If the counter COLUMN is less (e.g., the YES branch of step 266 ), the circuit 152 may (i) compute START_POINT=START_POINT+HORZ_S_INC and (ii) END_POINT=END_POINT+HORZ_E_INC in the step 268 . Thereafter, the method 250 may return to the step 256 to work on the next output column. Once the counter COLUMN reaches the value OUT_TILE_WIDTH (e.g., the NO branch of step 266 ), the method 250 may return to the step 252 and wait for the signal VALID to be come active again
The functions performed by the diagrams of FIGS. 1 , 4 , 6 , 8 and 9 may be implemented using one or more of a conventional general purpose processor, digital computer, microprocessor, microcontroller, RISC (reduced instruction set computer) processor, CISC (complex instruction set computer) processor, SIMD (single instruction multiple data) processor, signal processor, central processing unit (CPU), arithmetic logic unit (ALU), video digital signal processor (VDSP) and/or similar computational machines, programmed according to the teachings of the present specification, as will be apparent to those skilled in the relevant art(s). Appropriate software, firmware, coding, routines, instructions, opcodes, microcode, and/or program modules may readily be prepared by skilled programmers based on the teachings of the present disclosure, as will also be apparent to those skilled in the relevant art(s). The software is generally executed from a medium
The present invention may also be implemented by the preparation of ASICs (application specific integrated circuits), Platform ASICs, FPGAs (field programmable gate arrays), PLDs (programmable logic devices), CPLDs (complex programmable logic device), sea-of-gates, RFICs (radio frequency integrated circuits), ASSPs (application specific standard products) or by interconnecting an appropriate network of conventional component circuits, as is described herein, modifications of which will be readily apparent to those skilled in the art(s).
The present invention thus may also include a computer product which may be a storage medium or media and/or a transmission medium or media including instructions which may be used to program a machine to perform one or more processes or methods in accordance with the present invention. Execution of instructions contained in the computer product by the machine, along with operations of surrounding circuitry, may transform input data into one or more files on the storage medium and/or one or more output signals representative of a physical object or substance, such as an audio and/or visual depiction. The storage medium may include, but is not limited to, any type of disk including floppy disk, hard drive, magnetic disk, optical disk, CD-ROM, DVD and magneto-optical disks and circuits such as ROMs (read-only memories), RAMs (random access memories), EPROMs (electronically programmable ROMs), EEPROMs (electronically erasable ROMs), UVPROM (ultra-violet erasable ROMs), Flash memory, magnetic cards, optical cards, and/or any type of media suitable for storing electronic instructions.
The elements of the invention may form part or all of one or more devices, units, components, systems, machines and/or apparatuses. The devices may include, but are not limited to, servers, workstations, storage array controllers, storage systems, personal computers, laptop computers, notebook computers, palm computers, personal digital assistants, portable electronic devices, battery powered devices, set-top boxes, encoders, decoders, transcoders, compressors, decompressors, pre-processors, post-processors, transmitters, receivers, transceivers, cipher circuits, cellular telephones, digital cameras, positioning and/or navigation systems, medical equipment, heads-up displays, wireless devices, audio recording, storage and/or playback devices, video recording, storage and/or playback devices, game platforms, peripherals and/or multi-chip modules. Those skilled in the relevant art(s) would understand that the elements of the invention may be implemented in other types of devices to meet the criteria of a particular application.
While the invention has been particularly shown and described with reference to the preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made without departing from the spirit and scope of the invention.
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An apparatus generally having a first memory, a second memory and a circuit is disclosed. The first memory may be configured to store a warp table. The warp table is generally accessed through a single data port of the first memory. The second memory may be configured to buffer an input image. The input image may have a plurality of input pixels arranged in two dimensions. The circuit may be configured to generate an output image by a warp correction of an input image. The warp correction may be defined by the warp table. The output image may include a plurality of output pixels. At least one of the output pixels maybe generated during each clock cycle of the circuit.
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RELATED APPLICATIONS
[0001] This application is related to and claims the benefit of previously filed U.S. Provisional Application 61/358,521, filed Jun. 25, 2010 and entitled “Dual Therapy Exercise Device with Tethered Control Panel”.
BACKGROUND
[0002] The present invention relates to a device designed to assist a user in exercising certain muscles within their body, and thus helping to manage/control the user's weight. A preferred embodiment of the invention includes a system to provide multiple exercise therapies to a user, while also having a convenient and accessible user control device.
[0003] Many different exercise and weight loss devices currently exist. In addition to typical gym equipment (i.e. weights, treadmills, exercise bikes, etc.), examples include devices which apply electrical signals to produce involuntary contractions of targeted muscles and devices which subject muscles (and other body tissue) to a physical vibration signal. To focus the desired therapy on particular portion of the user's body, each of these devices include some type of attachment system which allows the device to be appropriately positioned.
[0004] When an exercise device includes electrical systems or components, it is often necessary to appropriately position a user interface or control panel so it is easily viewed or accessed by the user. Obviously, the positioning of this user interface should be at a location which is convenient and easy to use. Unfortunately, this may be difficult when the particular exercise device is positioned at certain locations. For example, if an exercise device is positioned adjacent a user's back, it is obviously difficult to include a convenient user interface on the device itself.
[0005] In addition to the placement of the user interface, the type of therapy provided and the effectiveness of the device can vary greatly. The effectiveness of the provided therapy is critically important and is a primary consideration for the design of exercise devices. Obviously, the device should be capable of effectively providing the desired therapy, and thus producing the desired results for the user. In this case, the device must provide appropriate therapies to exercise the user's muscle tissue.
SUMMARY
[0006] The preferred embodiments of the present invention provide a convenient multi-therapy exercise device that is capable of providing targeted exercise therapies to desired locations of a user's body. The device of the preferred embodiment provides both vibration and electrical stimulation therapy to the user by appropriately positioning the device adjacent the desired area. The dual therapies more efficiently exercise those portions of the user's body using both exercise methodologies. In addition, convenience is provided by having a control panel for the device which is detachable. In this manner, a user can easily view and access the control panel, no matter where the device is positioned.
DESCRIPTION OF THE DRAWINGS
[0007] Further objects and advantages of the present invention are described in the following detailed description, in conjunction with the drawings, in which:
[0008] FIG. 1 is a perspective view of a first embodiment of the present invention;
[0009] FIG. 2 is a perspective view of the first embodiment with a control panel being retracted;
[0010] FIG. 3 is an inside rear view of the first embodiment; and
[0011] FIG. 4 is a schematic diagram of the interior components within the first embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0012] Generally speaking, the preferred embodiment includes a belt structure which is wearable by a user to allow for the application of multiple exercise therapies. In this embodiment, these therapies include vibration therapy, and electrical signal stimulation therapy. In addition, a convenient and removable control panel is provided which can facilitate operation of the exercise device while positioned at all possible locations. Further, structures are included within a housing of the exercise device to retain the control panel at a seated location so the control panel is contained and not swinging dangerously during use. To accommodate the above discussed features of the control panel, a cord take-up mechanism helps to appropriately contain the cord, which is attached between the exercise device housing and the control panel. This take-up mechanism allows the cord and attached control panel to be easily pulled away from the exercise device so the user can easily see and operate the device.
[0013] Referring now to FIGS. 1 and 2 , one embodiment of an exercise device 10 of the present invention is illustrated. As shown, exercise device 10 includes a belt structure 12 and an exercise device housing 14 coupled to one another. Belt structure 12 is specifically configured to be positioned around the user's torso. That said, it is contemplated that exercise device 10 could be attached to other portions of the user's body, including arms or legs. In these alternative locations, it is also contemplated that belt structure 12 would be configured differently.
[0014] As better illustrated in FIG. 3 , belt 12 also includes a pair of electrodes 16 positioned on a backside thereof. As further discussed below, electrodes 16 are configured to contact a user's body when the belt structure 12 is attached, thus providing electrical signals to stimulate muscle contractions as desired.
[0015] As also shown in FIGS. 1-3 , exercise device 10 includes a removable control panel 20 , which is coupled to housing 14 via a cable or cord 22 . As best illustrated in FIG. 2 , control panel 20 includes a display 24 , a power button 26 and a plurality of control buttons 28 . Each of these components are utilized to control operation of the exercise device 10 as desired by the user. As discussed below, exercise device 10 includes the systems to provide multiple exercise therapies. It is contemplated that control panel 20 would provide appropriate components (i.e. displays 24 and control buttons 28 ) to control the various therapy systems, either independently or in conjunction with one another.
[0016] Referring now to FIG. 4 , the various components of exercise device 10 are schematically illustrated. More specifically, FIG. 4 illustrates an internal schematic view of housing 14 . As indicated above, cord 22 is utilized to electrically couple control panel 20 to the various components of exercise device 10 . To accommodate this, and also provide convenience to the user, a take-up system is included within housing 14 . More specifically, a take-up wheel 30 is housed within housing 14 at a position adjacent a top wall 18 . Cord 22 extends through an opening 32 in top wall 18 , and then around take-up wheel 30 . As will be recognized by those skilled in the art, take-up wheel 30 is spring loaded and includes various stop mechanisms to easily accommodate the withdrawal and retraction of cord 22 .
[0017] To provide further convenience, top wall 18 also includes a recessed section 40 which is configured to receive control panel 20 . In addition, a magnetic coupling system is utilized to hold control panel 20 in place when seated in recessed section 40 . In this particular embodiment, a pair of magnets 42 are positioned immediately below recessed portion 40 while cooperating metal plates 44 are positioned in a lower portion of control panel 20 . As anticipated, a magnetic coupling is created when control panel 20 is seated in recessed section 40 . In this matter, control panel 20 will be securely held in place until selectively removed by the user.
[0018] Also illustrated in FIG. 4 are the various components of exercise device 10 which are contained within housing 14 . Again, exercise device 10 of the present invention provides dual exercise therapies to the user, in order to increase efficiency and effectiveness. A first therapy is provided by a vibration system 50 located within housing 14 . Although the components are not specifically illustrated in FIG. 4 , it is contemplated that vibration system 50 will include a motor and an eccentric weight mechanism attached thereto. As will be easily recognized by those skilled in the art, actuation of the motor and rotation of this eccentric weight will cause internal vibration. When the exercise device 10 is attached to a user, this vibration will be transmitted to a user's body, thus creating a desired physiological effect. The size and speed of the eccentric weight can vary depending upon the desired strength and frequency of the vibration.
[0019] In addition, exercise device 10 also includes an electrical stimulation system 60 configured to provide low current electrical signals to the user's body. As generally discussed above, exercise device 10 includes electrodes 16 positioned on one side of belt structure 12 . These electrodes are driven or powered by electrical signal stimulation system 60 based upon the desired and well understood methodologies. These electrical stimulation methodologies will induce muscle contractions, thus providing desired muscle conditioning. As will be further appreciated, the strength and frequency of the electrical stimulation signals will directly effect the muscle exercise encountered by a user.
[0020] The overall operation of exercise device 10 is controlled by a system controller 100 which is also contained within housing 14 . System controller 100 communicates with control panel 20 , vibration system 50 and electrical stimulation system 60 in an effort to provide coordinated operation of all of these components. System controller 100 may include any well understood microprocessor or microcontroller, or variations thereof. Additionally, control processor 100 may be located within the body of control panel 20 , to more easily communicate with display 24 and control buffers 28 .
[0021] As discussed above, the preferred embodiments of the present invention provide both effective exercise therapies to a user, while also being convenient and easy to use. Naturally, variations are possible which will still achieve the coordinated overall operation as discussed above. For example, the control panel could be physically coupled, using appropriate clips or related physical structures as opposed to the magnetic coupling discussed above. Alternatively, the control panel could be coupled to the various therapy devices via a wireless coupling system. Further, the electrodes could take many forms depending on the therapy desired, or coupld include a number of additional electrodes. Additionally, exercise device 10 could be configured as a smaller belt, thus accommodating attachment to the user's arms or legs, as opposed to around their waist. Many different variations are also contemplated depending upon the desired positioning of the device and the related body structure to which the exercise therapies are being applied. As an additional alterative, those skilled in the art will recognize that alternative methods for generating the desired vibration generation could be used.
[0022] Although specific embodiments are discussed above and shown in the drawings, several additional variations exist. It is intended that all variations coming within the general scope and spirit of the following claims are necessarily included in this description.
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A device having a number of exercise therapy systems contained within a single housing is capable of providing multiple exercise therapies to a predetermined position of a user's body and thus efficiently exercising those portions of the user's body. To provide additional convenience, the device includes a user control panel that is movably coupled to the housing, thereby allowing removal in a manner which allow for easy user access. The multiple therapies can include both a vibration therapy and an electrical stimulation therapy, thus providing for more efficient exercising of the user's muscle tissue adjacent the housing.
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[0001] This application claims benefit of U.S. Provisional Application No. 60/460,676, filed Apr. 4, 2003 and 10/817,628, filed Apr. 2, 2004.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to laminated glass structures. This invention particularly relates to laminated glass structures that can withstand severe impact and/or severe pressure loads.
[0004] 2. Description of the Prior Art
[0005] Conventional glazing structures comprise a glazing element mounted in or to a support structure such as a frame. Such glazing elements can comprise a laminate window, such as a glass/interlayer/glass laminate window. There are various glazing methods known and which are conventional for constructing windows, doors, or other glazing elements for commercial and/or residential buildings. Such glazing methods are, for example: exterior pressure plate glazing; flush glazing; marine glazing; removable stop glazing; and, silicone structural glazing (also known as stopless glazing).
[0006] For example, U.S. Pat. No. 4,406,105 describes a structurally glazed system whereby holes are created through the glazing element and a plate member system with a connection being formed through the hole.
[0007] Threat-resistant windows and glass structures are known and can be constructed utilizing conventional glazing methods. U.S. Pat. No. 5,960,606 ('606) and U.S. Pat. No. 4,799,376 ('376) each describes laminate windows that are made to withstand severe forces. In International Publication Number WO 98/28515 (IPN '515) a glass laminate is positioned in a rigid channel in which a resilient material adjacent to the glass permits flexing movement between the resilient material and the rigid channel. Other means of holding glazing panels exist such as adhesive tapes, gaskets, putty, and the like and can be used to secure panels to a frame. For example, WO 93/002269 describes the use of a stiffening member that is laminated to a polymeric interlayer around the periphery of a glass laminate to stiffen the interlayer, which can extend beyond the edge of the glass/interlayer laminate. In another embodiment, '269 describes the use of a rigid member, which is inserted into a channel below the surface of a monolithic transparency, and extending from the transparency.
[0008] Windows and glass structures capable of withstanding hurricane-force winds and high force impacts are not trouble-free, however. Conventional glazing methods can require that the glazing element have some extra space in the frame to facilitate insertion or removal of the glazing element. While the additional space facilitates installation, it allows the glazing element to move in a swinging, rocking, or rotational motion within the frame. Further, it can move from side to side (that is, in the transverse direction) in the frame depending upon the magnitude and direction of the force applied against the glazing element. Under conditions of severe repetitive impact and/or either continuous or discontinuous pressure, a glass laminate can move within the frame or structural support in such a way that there can be sufficient stress built up to eventually fracture the window and allow the laminate to be pulled out of the frame. For example, when subjected to severe hurricane force winds the flexing movement in the windows of IPN '515, wherein glass flexes within a rigid channel, can gradually pull the laminate out of the channel resulting in loss of integrity of the structure. In '376, the glass held against the frame can be broken and crushed, causing a loss of structural integrity in the window/frame structure. In WO '269, inserting a stiff foreign body into the interlayer as described therein can set up the structure for failure at the interface where the polymer contacts the foreign body when subjected to severe stresses.
[0009] WO 00/64670 describes glass laminates that utilize the interlayer as a structural element in glazing structures thereby providing greater structural integrity to the laminate during duress or after initial fracture of the glass.
SUMMARY OF THE INVENTION
[0010] In one aspect, the present invention is a glazing element useful for exterior pressure plate glazing comprising a transparent laminate and an attachment means for attaching the laminate to a support structure wherein: (1) the laminate comprises at least one layer of glass bonded directly to a thermoplastic polymer interlayer on at least one surface of the glass; (2) the interlayer extends beyond at least one edge of the laminate; (3) one surface of the extended portion of the interlayer is bonded to at least one surface of the attachment means; (4) another surface of the extended portion of the interlayer is bonded to the glass; (5) the attachment means is a clip useful for aligning and holding the laminate in a retaining channel of the support structure; (6) the clip further comprises at least one interlocking extension useful for restricting rotational and/or transverse movement of the laminate within the channel and/or movement of the laminate out of the channel.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a conventional glass laminate in a frame.
[0012] FIG. 2 is a glass/plastic/glass laminate of the present invention comprising a thermoplastic interlayer, wherein the laminate is held in a channel formed from a mullion and a pressure plate, the laminate being held in place with the assistance of an attachment means bonded to the thermoplastic interlayer.
[0013] FIG. 3 depicts a glazing element having a reduced moment arm compared with the glazing element of FIG. 2 due to a redesigned pressure plate.
[0014] FIG. 4 depicts a glazing element comprising an attachment means having two symmetrical extensions and a redesigned mullion having recesses for accepting and constraining one of the extensions.
[0015] FIG. 5 depicts an attachment clip having two symmetrical extensions and a flattened surface.
[0016] FIG. 6 depicts an attachment clip having two extensions that are not identical.
[0017] FIG. 7 depicts an attachment clip having one extension and an adhesive applied inside the channel to restrict rocking of the glazing under negative pressure.
DETAILED DESCRIPTION OF THE INVENTION
[0018] FIG. 1 shows a conventional laminate comprising glass ( 1 ), a thermoplastic interlayer ( 2 ) and glass ( 3 ), the glass being attached to a frame ( 4 ) through an intermediary adhesive layer ( 5 ) which is typically a gasket, putty, sealant tape, or silicone sealant.
[0019] The present invention is a glass laminate system that utilizes the interlayer for the purpose of attaching the laminate to the support structure, as described in WO 00/64670, hereby incorporated by reference. In a process for producing glazing units for architectural applications that incorporate the interlayer as a structural element of the glazing, it has now been found that attaching the interlayer of a glass laminate to a support structure for the laminate can provide glazing units having improved strength and structural integrity against severe threats. The present invention relates to glazing elements that are constructed for exterior pressure plate glazing applications and which utilize the interlayer to attach to the structural support.
[0020] In a conventional exterior pressure plate glazing application, the glazing element is typically inserted into a frame, which comprises a mullion and a pressure plate. The mullion and pressure plate are useful for the purpose of providing an attachment for the glazing element to the building or structure being fitted with the glazing element. The pressure plate is used in concert with the mullion to hold the glazing element securely in place in the frame. The pressure plate is attached to the mullion using a fastener.
[0021] In one embodiment, the glazing element of this invention comprises a support structure capable of supporting a glazing structure comprising a laminate having at least one layer of glass and at least one thermoplastic polymer interlayer that is self-adhered directly to at least one surface of the glass. By self-adhered, it is meant that the interlayer/glass interface does not require and therefore possibly may not include any intervening layers of adhesives and/or glass surface pre-treatment to obtain bonding suitable for use as a safety glass. In some applications it is preferable that there is no intervening film or adhesive layer.
[0022] Thermoplastic polymers useful in the practice of the present invention should have properties that allow the interlayer to provide conventional advantages to the glazing, such as transparency to light, adhesion to glass, and other known and desirable properties of an interlayer material. In this regard, conventional interlayer materials can be suitable for use herein. Conventional interlayer materials include thermoplastic polymers. Suitable polymers include, for example; polyvinylbutyrals (PVB); polyvinyl chlorides (PVC); polyurethanes (PUR); polyvinyl acetate; ethylene acid copolymers and their ionomers; polyesters; copolyesters; polyacetals; and others known in the art of manufacturing glass laminates. Blended materials using any compatible combination of these materials can be suitable, as well. In addition, a suitable interlayer material for use in the practice of the present invention should be able to resist tearing away from a support structure under extreme stress. A sheet of a suitable polymer for use in the practice of the present invention has a high modulus, excellent tear strength and excellent adhesion directly to glass. As such, a suitable interlayer material or material blend should have a Storage Young's Modulus of at least 50 MPa at temperatures up to about 40° C. It can be useful to vary the thickness of the interlayer in order to enhance the tear strength, for example.
[0023] While many conventional thermoplastic polymers can be suitable for use in the practice of the present invention, preferably the polymer is an ethylene acid copolymer. More preferably the thermoplastic polymer is an ethylene acid copolymer obtained by the copolymerization of ethylene and a α,β-unsaturated carboxylic acid, or derivatives thereof. Suitable derivatives of acids useful in the practice of the present invention are known to those skilled in the art, and include esters, salts, anhydrides, amides, nitrites, and the like. Acid copolymers can be fully or partially neutralized to the salt (or partial salt). Fully or partially neutralized acid copolymers are known conventionally as ionomers. Suitable copolymers can include an optional third monomeric constituent that can be an ester of an ethylenically unsaturated carboxylic acid. Suitable acid copolymers useful in the practice of the present invention can be purchased commercially from, for example, E.I. DuPont de Nemours & Company under the trade names of Surlyn® and Nucrel®, for example.
[0024] In the practice of the present invention the edges of the interlayer can be attached either directly to a support structure or indirectly to the support structure by way of an attachment means. As contemplated in the practice of the present invention, a support structure can be any structural element or any combination of structural elements that hold the glazing element in place on the building or support the weight of the glazing element. The support structure can comprise a frame, bolt, screw, wire, cable, nail, staple, and/or any conventional means for holding or supporting a glazing element, or any combination thereof. In the present invention, “support structure” can mean the complete or total support structure, or it can refer to a particular structural component or element of the complete support structure. One skilled in the art of glazing manufacture will know from the context which specific meaning to apply. Direct attachment of the interlayer, as contemplated herein, means a direct attachment of the laminate to the support structure or any element thereof wherein the interlayer is in direct and consistent contact with the support structure. Direct attachment of the interlayer to the support can be from the top, sides, bottom, or through the interlayer material. By indirect attachment it is meant any mode of attachment wherein the interlayer does not have direct contact with the support structure, but does have contact with the support structure through at least one intervening structural component of the glazing element. Indirect attachment of the interlayer to the support structure by way of an attachment means is most preferable in the practice of the present invention. The attachment means can be any means for holding or constraining the glass laminate into a frame or other support structure.
[0025] In a preferred embodiment, the attachment means is an attachment clip that can be bonded to an extended portion of the interlayer by a bonding process. In the practice of the present invention there is no direct contact intended between the clip and any portion of the glass layer(s) of the laminate, and any such contact is incidental. In any event, it can be preferred to minimize contact between the clip and the glass in order to reduce glass fracture under stress or during movement of the laminate in the support structure. To that end, the portion of the interlayer that extends from the edges of the laminate preferably forms an intervening layer between the clip and the glass layer such that the clip does not contact the glass. The surface of the clip that contacts the interlayer can be smooth, but preferably the surface of the clip has at least one projection and/or one recessed area, and more preferably several projections and/or recessed areas, which can provide additional surface area for bonding as well as a mechanical interlocking mechanism with the interlayer to enhance the effectiveness of the adhesive bonding between the dip and the interlayer, thereby providing a laminate/dip assembly with greater structural integrity.
[0026] In another embodiment, a conventional glass laminate unit can be used to create a laminate glazing unit of the present invention. To achieve the same or similar effect as in other embodiments, the interlayer material can be bonded to the thermoplastic material without the necessity of actually extending the interlayer beyond the edges of the laminate. In this embodiment, strips of thermoplastic polymer material suitable for bonding to the thermoplastic interlayer can be positioned on the periphery of the laminate and heated to promote melting, or flow, of the interlayer and the thermoplastic polymer on the periphery of the laminate such that the two materials come into direct contact and become blended. Upon cooling below the melting point of the polymers, the two materials will be bonded to one another and thus be available to perform the bonding function between the glass and the attachment means. Other processes for bonding the interlayer to the attachment means can be contemplated and within the scope of the present invention if the interlayer is effectively extended outside the edges of the laminate by that process. The thermoplastic polymer can be the same polymer as used for the interlayer, or it can be a different material that forms a strong enough bond with the interlayer material under the process conditions used. In a preferred embodiment bonding the thermoplastic strips to the glass of the laminate and to the attachment means can be performed simultaneously.
[0027] A bonding process suitable for use in the practice of the present invention is any wherein the interlayer can be bonded to the attachment means. In the present invention, by “bonding” it is meant that the interlayer and the attachment means form a bond that results in adhesion between the attachment means and the interlayer. Bonding can be accomplished by physical means or by chemical means, or by a combination of both. Physical bonding, for the purposes of the present invention, is adhesion that results from interaction of the interlayer with the attachment means wherein the chemical nature of the interlayer and/or the attachment means is unchanged at the surfaces where the adhesion exists. For example, adhesion that results from intermolecular forces, wherein covalent chemical bonds are neither created nor destroyed, is an example of physical bonding. Chemical bonding, according to the present invention, would require forming and/or breaking covalent chemical bonds at the interface between the interlayer and the attachment means in order to produce adhesion.
[0028] The bonding process of the present invention preferably comprises the step of applying heat to the dip while it is in direct contact with the interlayer, that is, applying heat or energy to a clip/interlayer assembly such that the polymeric interlayer and the clip are bonded at the interface where the clip and interlayer are in contact. Without being held to theory, it is believed that this results in a physical bonding rather than a chemical bonding. Application of heat in the bonding process can be accomplished by various methods, including the use of: a heated tool; microwave energy; or ultrasound to heat the interlayer and/or the attachment clip and promote bonding. Preferably the clip/interlayer assembly can be bonded at a temperature of less than about 175° C., more preferably at a temperature of less than about 165° C. Most preferably, the clip/interlayer assembly can be bonded at a temperature of from about 125° C. to about 150° C. Once bonded, the clip/interlayer/laminate form a laminate/clip assembly that can be fitted or otherwise attached to a frame or other support structure.
[0029] A clip that is suitable for use in the practice of the present invention has a mechanical interlocking extension that can, by interlocking with the support structure, reduce the motion available to the laminate in the channel of a frame, or against any other rigid support structure member. The extension member of the clip can thereby reduce the force of the rigid support structure against the laminate and also assist in holding the laminate in or to the support structure. The extension member can have various forms and/or shapes to accomplish its function. For example, the extension member can form part of a ball and socket; it can form a “C”, an “L”, or a “T” shape to hold it into the support structure, or it can be any sort of extension arm such as a hook or a clamp, for example. Any design of the extension member, which accomplishes the function of facilitating the laminate being held into the support structure, is contemplated as within the scope of the present invention.
[0030] For the purposes of this invention, a laminate/clip assembly of the present invention is said to be attached to a support structure if the assembly is nailed, screwed, bolted, glued, slotted, tied or otherwise constrained from becoming detached from the structure. Preferably, a laminate/clip assembly of the present invention is geometrically and/or physically constrained within a channel formed by elements of a conventional framing structure. In the practice of the present invention, a conventional framing structure comprises a mullion which functions to attach and hold a glazing element to a building, for example. A framing structure useful in the practice of the present invention can comprise a pressure plate and a fastener which functions to hold a glazing element in place against the mullion. Use of pressure plates and mullions in the glazing art for exterior glazing is conventional.
[0031] In one of the preferred embodiments of the present invention, depicted in FIG. 2 , a glazing element ( 1 ) comprises: a glass ( 2 )/interlayer ( 3 )/glass ( 2 ) laminate; and an attachment clip ( 4 ). The glazing element is contacted by gaskets ( 7 ), which assist in holding the glazing element in a channel formed by a mullion ( 5 ) and a pressure plate ( 6 ). The attachment clip comprises an interlocking extension ( 9 ), which projects outward and away from the outer edge of the laminate. The arm can function to restrict the movement of the glazing element within the frame channel ( 10 ) by cutting down on the rocking motion available to the laminate upon being subjected to positive pressure at the surfaces of the laminate. In addition, the arm can assist in keeping the laminate from being pulled out by movement of the glazing element from side to side. The fastener ( 11 ) holds the pressure plate and mullion together, and can be tightened or loosened to apply more or less pressure to the gaskets holding the glazing element. A thermal separator ( 12 ) can be used for temperature insulation. The design depicted in FIG. 2 results in a laminate that can withstand either severe positive pressure or negative pressure loads. The clip can optionally comprise an engagement hook at the end of the extension, to assist in retaining the laminate in the frame channel.
[0032] In another embodiment depicted in FIG. 3 , the glazing element shown therein is identical to the glazing element of FIG. 2 . The mullion and pressure plate are identical to FIG. 2 except that the shape of the thermal separator ( 12 ) has been redesigned and inverted in order to reduce the moment arm of the glazing element. The reduced moment arm can further restrict the movement in the channel in a manner that can prevent sufficient force being generated to damage the laminate and/or allow the laminate to be pulled from the structure.
[0033] In another embodiment depicted in FIG. 4 , the glazing element is identical to the glazing element of FIG. 3 , except that the attachment clip ( 4 a ) comprises a second extension arm ( 13 ), which functions to further promote retention of the glazing element in the channel ( 10 ) whether subject to either positive or negative pressure. The mullion of FIG. 4 has a recess ( 14 ) to accept the additional extension arm.
[0034] In another preferred embodiment depicted in FIG. 5 , the glazing element is identical to the glazing element of FIG. 3 , except that the attachment clip ( 4 b ) has a flattened surface, which is more amenable to the application of heat during the clip/interlayer bonding process. The modified design of the clip in FIG. 5 can result in greater glass capture or glass bite, of the laminate in the frame, which can result in greater structural integrity for the glazing element. The mullion of FIG. 5 is identical to the mullion of FIG. 4 .
[0035] In still another preferred embodiment shown in FIG. 6 , the glazing element is identical to the glazing element of FIG. 3 , except that the attachment clip ( 4 c ) comprises a second extension arm ( 13 a ) that is shorter than extension arm ( 9 ), and functions to promote retention of the glazing element in the channel ( 10 ) whether subject to either positive or negative pressure. The mullion of FIG. 6 is identical to the mullion of FIG. 3 .
[0036] In still another preferred embodiment shown in FIG. 7 , the glazing element is identical to the glazing element of FIG. 3 , except that the attachment clip ( 4 ) is bonded to the mullion by an adhesive ( 14 ). While an adhesive is optional in the practice of the present invention, use of an adhesive in this manner does not require great skill and technical prowess to apply the adhesive because the adhesive is not visible outside of the frame of the glazing element.
[0037] A laminate of the present invention has excellent durability, impact resistance, toughness, and resistance by the interlayer to cuts inflicted by glass once the glass is shattered. A laminate of the present invention is particularly useful in architectural applications in buildings subjected to hurricanes and windstorms. A laminate of the present invention that is attached or mounted in a frame by way of the interlayer is not torn from the frame after such stress or attack. A laminate of the present invention also has a low haze and excellent transparency. These properties make glazing elements of the present invention useful as architectural glass, including use for reduction of solar rays, sound control, safety, and security, for example.
[0038] In a preferred embodiment, the interlayer is positioned between the glass plates such that the interlayer is exposed in such a manner that it can be attached to the surrounding frame. The interlayer can be attached to the support structure in a continuous manner along the perimeter of the laminate. Alternatively, the interlayer can be attached to the structural support in a discontinuous manner at various points around the perimeter of the laminate. Any manner of attaching the laminate to the frame by way of the interlayer is considered to be within the scope of the present invention. For example, the frame surrounding the laminate can contain interlayer material that can bond with the laminate and also with the frame; the laminate can be mechanically anchored to the frame with a screw, hook, nail, or clamp, for example. Mechanical attachment includes any physical constraint of the laminate by slotting, fitting, or molding a support to hold the interlayer in place within the structural support.
[0039] Air can be removed from between the layers of the laminate, and the interlayer can be bonded, or adhered, to the glass plates by conventional means, including applying heat and pressure to the structure. In a preferred embodiment, the interlayer can be bonded without applying increased pressure to the structure.
[0040] One preferred laminate of this invention is a transparent laminate comprising two layers of glass and an intermediate thermoplastic polymer interlayer self-adhered to at least one of the glass surfaces. The interlayer preferably has a Storage Young's Modulus of 50-1,000 MPa (mega Pascals) at 0.3 Hz and 25° C., and preferably from about 100 to about 500 MPa, as determined according to ASTM D 5026-95a. The interlayer should remain in the 50-1,000 MPa range of its Storage Young's Modulus at temperatures up to 40° C.
[0041] The laminate can be prepared according to conventional processes known in the art. For example, in a typical process, the interlayer is placed between two pieces of annealed float glass of dimension 12″×12″ (305 mm×305 mm) and 2.5 mm nominal thickness, which have been washed and rinsed in demineralized water. The glass/interlayer/glass assembly is then heated in an oven set at 90-100° C. for 30 minutes. Thereafter, it is passed through a set of nip rolls (roll pressing) so that most of the air in the void spaces between the glass and the interlayer may be squeezed out, and the edge of the assembly sealed. The assembly at this stage is called a pre-press. The pre-press is then placed in an air autoclave where the temperature is raised to 135° C. and the pressure raised to 200 psig (14.3 bar). These conditions are maintained for 20 minutes, after which, the air is cooled while no more air is added to the autoclave. After 20 minutes of cooling when the air temperature in the autoclave is less than 50° C., the excess air pressure is vented. Obvious variants of this process will be known to those of ordinary skill in the art of glass lamination, and these obvious variants are contemplated as suitable for use in the practice of the present invention.
[0042] Preferably, the interlayer of the laminate is a sheet of an ionomer resin, wherein the ionomer resin is a water insoluble salt of a polymer of ethylene and methacrylic acid or acrylic acid, containing about 14-24% by weight of the acid and about 76-86% by weight of ethylene. The ionomer further characterized by having about 10-80% of the acid neutralized with a metallic ion, preferably a sodium ion, and the ionomer has a melt index of about 0.5-50. Melt index is determined at 190° C. according to ASTM D1238. The preparation of ionomer resins is disclosed in U.S. Pat. No. 3,404,134. Known methods can be used to obtain an ionomer resin with suitable optical properties. However, current commercially available acid copolymers do not have an acid content of greater than about 20%. If the behavior of currently available acid copolymer and ionomer resins can predict the behavior of resins having higher acid content, then high acid resins should be suitable for use herein.
[0043] Haze and transparency of laminates of this invention are measured according to ASTM D-1003-61 using a Hazeguard XL211 hazemeter or Hazeguard Plus Hazemeter (BYK Gardner-USA). Percent haze is the diffusive light transmission as a percent of the total light transmission. To be considered suitable for architectural and transportation uses. The interlayer of the laminates generally is required to have a transparency of at least 90% and a haze of less than 5%.
[0044] In the practice of the present invention, use of a primer or adhesive layer can be optional. Elimination of the use of a primer can remove a process step and reduce the cost of the process, which can be preferred.
[0045] Standard techniques can be used to form the resin interlayer sheet. For example, compression molding, injection molding, extrusion and/or calendaring can be used. Preferably, conventional extrusion techniques are used. In a typical process, an ionomer resin suitable for use in the present invention can include recycled ionomer resin as well as virgin ionomer resin. Additives such a colorants, antioxidants and UV stabilizers can be charged into a conventional extruder and melt blended and passed through a cartridge type melt filter for contamination removal. The melt can be extruded through a die and pulled through calendar rolls to form sheet about 0.38-4.6 mm thick. Typical colorants that can be used in the ionomer resin sheet are, for example, a bluing agent to reduce yellowing or a whitening agent or a colorant can be added to color the glass or to control solar light.
[0046] The polymer sheet after extrusion can have a smooth surface but preferably has a roughened surface to effectively allow most of the air to be removed from between the surfaces in the laminate during the lamination process. This can be accomplished for example, by mechanically embossing the sheet after extrusion or by melt fracture during extrusion of the sheet and the like. Air can be removed from between the layers of the laminate by any conventional method such as nip roll pressing, vacuum bagging, or autoclaving the pre-laminate structure.
[0047] The Figures do not represent all variations thought to be within the scope of the present invention. One of ordinary skill in the art of glazing manufacture would know how to incorporate the teachings of the present invention into the conventional art without departing from the scope of the inventions described herein. Any variation of glass/interlayer/glass laminate assembly wherein a frame can be attached to the interlayer—either directly or indirectly through an intermediary layer, for example an adhesive layer, is believed to be within the scope of the present invention.
[0048] For architectural uses a laminate can have two layers of glass and an interlayer of a thermoplastic polymer. Multilayer interlayers are conventional and, can be suitable for use herein, provided that at least one of the layers can be attached to the support structure as described herein. A laminate of the present invention can have an overall thickness of about 3-30 mm. The interlayer can have a thickness of about 0.38-4.6 mm and each glass layer can be at least 1 mm thick. In a preferred embodiment, the interlayer is self-adhered directly to the glass, that is, an intermediate adhesive layer or coating between the glass and the interlayer is not used. Other laminate constructions can be used such as, for example, multiple layers of glass and thermoplastic interlayers; or a single layer of glass with a thermoplastic polymer interlayer, having adhered to the interlayer a layer of a durable transparent plastic film. Any of the above laminates can be coated with conventional abrasion resistant coatings that are known in the art.
[0049] The frame and/or the attachment means can be fabricated from a variety of materials such as, for example: wood; aluminum; steel; and various strong plastic materials including polyvinyl chloride and nylon. Depending on the material used and the type of installation, the frame may or may not be required to overlay the laminate in order to obtain a fairly rigid adhesive bond between the frame and the laminate interlayer.
[0050] The frame can be selected from the many available frame designs in the glazing art. The laminate can be attached, or secured, to the frame with or without use of an adhesive material. It has been found that an interlayer made from ionomer resin self-adheres securely to most frame materials, such as wood, steel, aluminum and plastics. In some applications it may be desirable to use additional fasteners such as screws, bolts, and clamps along the edge of the frame. Any means of anchoring the attachment means to the frame is suitable for use in the present invention.
[0051] In preparing the glazing elements of this invention, autoclaving can be optional. Steps well known in the art such as: roll pressing; vacuum ring or bag pre-pressing; or vacuum ring or bagging; can be used to prepare the laminates of the present invention. In any case, the component layers are brought into intimate contact and processed into a final laminate, which is free of bubbles and has good optics and adequate properties to insure laminate performance over the service life of the application. In these processes the objective is to squeeze out or force out a large portion of the air from between the glass and plastic layer(s). In one embodiment the frame can serve as a vacuum ring. The application of external pressure, in addition to driving out air, brings the glass and plastic layers into direct contact and adhesion develops.
[0052] For architectural uses in coastal areas, the laminate of glass/interlayer/glass must pass a simulated hurricane impact and cycling test which measures resistance of a laminate to debris impact and wind pressure cycling. A currently acceptable test is performed in accordance to the South Florida Building Code Chapter 23, section 2315 Impact tests for wind born debris. Fatigue load testing is determined according to Table 23-F of section 2314.5, dated 1994. This test simulates the forces of the wind plus air born debris impacts during severe weather, e.g., a hurricane. A sample 35 inches×50 inches (88.9×127 cm) of the laminate is tested. The test consists of two impacts on the laminate (one in the center of the laminate sample followed by a second impact in a corner of the laminate). The impacts are done by launching a 9-pound (4.1 kilograms) board nominally 2 inches (5 cm) by 4 inches (10 cm) and 8 feet (2.43 meters) long at 50 feet/second (15.2 meters/second) from an air pressure cannon. If the laminate survives the above impact sequence, it is subjected to an air pressure cycling test. In this test, the laminate is securely fastened to a chamber. In the positive pressure test, the laminate with the impact side outward is fastened to the chamber and a vacuum is applied to the chamber and then varied to correspond with the cycling sequences set forth in Table 1. The pressure cycling schedule, shown in Table 1, is specified as a fraction of the maximum pressure (P). In this test P equals 70 PSF (pounds per square foot), or 3360 Pascals. Each cycle of the first 3500 cycles and subsequent cycles is completed in about 1-3 seconds. On completion of the positive pressure test sequence, the laminate is reversed with the impact side facing inward to the chamber for the negative pressure portion of the test and a vacuum is applied corresponding to the following cycling sequence. The values are expressed as negative values
[0000]
TABLE 1
Pressure Range [pounds
Number of Air
Pressure
per
Pressure Cycles
Schedule*
square foot (Pascals)]
Positive Pressure (inward acting)
3,500
0.2 P to 0.5 P
14 to 35 (672-1680
Pascals)
300
0.0 P to 0.6 P
0 to 42 (0-2016 Pascals)
600
0.5 P to 0.8 P
35 to 56 (1680-2688
Pascals)
100
0.3 P to 1.0 P
21 to 70 (1008-3360
Pascals)
Negative Pressure (outward acting)
50
−0.3 P to −1.0 P
−21 to −70 (−1008 to −3360
Pascals)
1,060
−0.5 P to −0.8 P
−35 to −56 (−1680 to −2688
Pascals)
50
0.0 P to −0.6 P
−0 to −42 (0 to −2016
Pascals)
3,350
−0.2 P to −0.5 P
−14 to −35 (−672 to −1680
Pascals)
*Absolute pressure level where P is 70 pounds per square foot (3360 Pascals).
[0053] A laminate passes the impact and cycling test when there are no tears or openings over 5 inches (12.7 cm) in length and not greater than 1/16 inch (0.16 cm) in width.
[0054] Other applications may require additional testing to determine whether the glazing is suitable for that particular application. A glazing membrane and corresponding support structure can fail by one of three failure modes:
1. The glazing membrane breaches (a tear or hole develops) as a result of a force being applied to the glazing or surrounding structure. 2. The glazing membrane pulls away or from the support structure losing mechanical integrity such that the glazing membrane no longer provides the intended function, generally a barrier. 3. The support structure fails by loss of integrity within its makeup or loss of integrity between the support structure and the surrounding structure occurs.
Only failure modes 1 and/or 2 defined above are the subject of the present invention.
[0058] The best-optimized system is defined herein as one where no failure occurs in any component/subcomponent of the glazing system when the maximum expected ‘threat’ is applied to the glazing system. When some threshold is exceeded, the ideal failure mode is one where a balance is achieved between failure modes 1 and 2 above. If the glazing membrane itself can withstand substantially more applied force or energy then the support structure has capability to retain the glazing, then the glazing ‘infill’ is over-designed or the glazing support structure is under-designed. The converse is also true.
EXAMPLES
[0059] The Examples are for illustrative purposes only, and are not intended to limit the scope of the invention.
Examples 1 Through 3 and Comparative Examples C1 Through C3
[0060] Conventional glass laminates were prepared by the following method. Two sheets of annealed glass having the dimensions of 300 mm×300 mm (12 inches square) were washed with de-ionized water and dried. A sheet (2.3 mm thick) of ionomer resin composed of 81% ethylene, 19% methacrylic acid, with 37% of the acid neutralized and having sodium ion as the counter-ion, and having a melt index of 2 was placed between two pieces of glass. A nylon vacuum bag was placed around the prelaminate assembly to allow substantial removal of air from within (air pressure inside the bag was reduced to below 100 millibar absolute). The bagged prelaminate was heated in a convection air oven to 120° C. and held for 30 minutes. A cooling fan was used to cool the laminate to ambient temperature and the laminate was disconnected from the vacuum source and the bag removed yielding a fully bonded laminate of glass and interlayer.
[0061] Laminates of the present invention were prepared in the same manner as above with the following exception. In some of the examples a triangular-shaped ‘corner-box’ retaining assembly as depicted in FIGS. 6 and 9 of the present application, having a wall thickness of 0.2 mm and dimensions of 50 mm×50 mm×71 mm (inside opening of 10 mm) was placed on each corner of the laminate after fitting pieces of ionomer sheet (2.3 mm thickness) within the inside of the box thereby ‘lining’ the inside. The assembly was placed into the vacuum bag and the process above was carried out to directly ‘bond’ the attachment to the interlayer. To better insure that the laminates were free of void areas, that is entrained bubbles, areas of non-contact between the ionomer and glass surface and that good flow and contact was made between the ionomer and the inside of the ‘corner-box’ all laminates were then placed in an air autoclave for further processing. The pressure and temperature inside the autoclave was increased from ambient to 135° C. and 200 psi in a period of 15 minutes. This temperature and pressure was held for 30 minutes and then the temperature was decreased to 40° C. within a 20-minute period whereby the pressure was lowered to ambient atmospheric pressure and the unit was removed.
[0062] A test apparatus similar to that described in SAE Recommended Practice J-2568 (attached as Appendix) was assembled to measure the degree of membrane integrity. The apparatus consisted of a hydraulic cylinder with integral load cell driving a hemispherical metal ram (200 mm diameter) into the center of each glazing sample in a perpendicular manner, measuring the force/deflection characteristics. Deflection was measured with a string-potentiometer attached to the ram. The glazing sample was supported either by a metal frame capturing the sample around the periphery, only at the corners or any configuration where performance information is desired. The data acquisition was done via an interface to a computer system with the appropriate calibration factors. Further treatment of the data was then possible to calculate the Maximum Applied Force (F max ) in Newtons (N), and the deflection. Integration of the data enabled the derivation the total energy expended in reaching a failure point of the glazing or supporting conditions. Testing of the laminates was done after fracturing the laminate in order to more accurately measure the load-bearing capability of the interlayer attachment system.
[0063] Example C1 was an annealed glass plate (10 mm) that was stressed until fracture. The test glazing had a standard installation with all four sides captured by the frame using a typical amount of edge capture (that is, overlap of the frame and glass), and lined with an elastomeric gasket.
[0064] Example C2 was a 90-mil polyvinylbutyral (PVB) laminate that was prefractured. The laminate construction was a typical patch plate design.
[0065] Example C3 was a 90-mil SentryGlas® Plus (SGP) laminate that was prefractured and constructed with a typical patch plate design.
[0066] Example 1 was a laminate of the present invention, using a 90-mil SentryGlas® Plus interlayer that was prefractured and constructed with a full perimeter attachment design (that is, the interlayer was attached to the frame around the full perimeter of the laminate).
[0067] Example 2 was the same as Example 1, except that it was constructed with a corner attachment design.
[0068] Example 3 was the same as Example 2, except that a 180-mil SentryGlas® Plus laminate that was used.
[0069] To measure the relative performance of a glazing membrane capacity against an applied force/energy and the capability for the glazing support structure (or means) to retain the glazing the following testing was performed. The displacement (D), which is defined as the distance traveled by the ram from engaging the laminate to the point of laminate failure, was measured. The membrane strength to integrity (S/R) ratio was measured. The S/R ratio is defined as the ratio of the applied energy required to cause a failure in a given laminate over the applied energy required to break C1. The performance benefit (B) over the traditional patch plate design was calculated by dividing the applied energy required for failure in the laminate by the applied energy required to for failure in C3. The resulting data is supplied in Table 2.
[0000]
TABLE 2
F max
Ex
D (mm)
(N)
S/R
B
C1
9
5284
1
.02
C2
122
108
22
.5
C3
65
939
45
1
1
80
11595
408
9.1
2
80
7243
274
6.1
3
90
9003
452
10.0
[0070] Examples 4 through 10 and Comparative Example C4 Laminates were prepared using 9/16″ thick laminated glass incorporating 0.090″ thick SentryGlas® Plus, available from E.I DuPont de Nemours and Company (DuPont) and ¼″ heat strengthened glass. In all but one respect this is a common glazing alternative used in commercial glazing applications for large missile impact resistance. The improvement over the existing industry standards is the attachment means used, that is, bonding of aluminum profiles to the laminated glass' interlayer edge with a contact-heating device. The aluminum profile was a “u” channel shape with a leg extending from the base of the “u” engaging an interlocking profile design in a custom extruded pressure plate. The 12″ long aluminum profiles were positioned around the glass edge in strategic locations to determine the most optimal location for load transfer within the glazed system. The attachment means geometry used for design validation was purposely designed to minimally impact the framing system into which it was installed. Because of this, the structural performance on inward acting air pressure cyclical loads behaved differently within the system than outward acting air pressure loads. This allowed for validation that the design of the attachment means of the present invention did indeed provide a substantial improvement over conventionally dry glazed systems.
[0071] Eight different individual test specimens were subjected to the test procedures required for large missile impact resistance with the location of the attachment means of the present invention varying with each test specimen. Example C4 was tested without any attachments of the present invention to define a baseline performance standard for a dry-glazed application with ½″ glass bite. Each test specimen was 63″ wide×120″ high and was mounted in a steel test frame to simulate a punched opening installation in a building.
[0072] All of the tested specimens passed the required impact resistance with a 2″×4″ wooden missile weighing 9# and traveling at 50 feet/second. The results of the cycling test for the various test specimens are shown in Table 3. Pressure cycling was conducted according to the Pressure Schedule shown in Table 1. A laminate of the present invention is given a passing mark for (+) load if the laminate holds in the support structure at 4500 cycles in the positive load direction and a passing mark in the (−) load direction at 4500 cycles in the negative load direction. The test laminates (with the exception of the comparative example) were designed so that the attachment means of the present invention was only engaged in the (+) load direction, and retention under negative load would be nearly identical to conventional laminates.
[0073] The units that failed in the negative load direction demonstrated precisely how much of an improvement the attachment means provided the installation. Given that without the attachment means, the limitation for a framing of this type, dry-glazed, with ½″ glass bite is about a 50 PSF design pressure differential. Through testing at least a doubling of the effective design pressure differential to 100 PSF was demonstrated. It is contemplated that higher-pressure loads would have been obtainable had the interior extruded aluminum profiles been designed to accept the attachment clips as well.
[0000]
TABLE 3
Ex
Pressure
Results
Cycles (no.)
C4
+/−50 PSF
Passed +/− loads
9000
4
+/−100 PSF
Failed + load
4424
5
+/−100 PSF
Failed + load
3800
6
+/−100 PSF
Failed + load
4416
7
+/−100 PSF
Passed + load
4509
8
+/−100 PSF
Passed + load
4502
9
+/−100 PSF
Failed + load
4409
10
+/−100 PSF
Passed + load
4500
Examples 11 Through 15, C5 and C6
[0074] Laminates of the present invention were constructed similarly to FIGS. 2 and 3 (Examples 11-13) and FIGS. 4 and 5 (Examples 14 and 15). The tensile force required to failure was measured on unbroken laminates and on intentionally broken laminates. Examples 13 and 14 utilized aluminum (Al) frames which were modified with grooves to allow the polymer to flow into channels in the surface of the frames, creating additional mechanical interlocking of polymer to frame. The results are shown in Table 4.
[0000]
TABLE 4
Pre-test
Tensile
Example
Frame Style
Damage
Force (lbs)
C5
gasket
unbroken
24.7
C6
silicone
unbroken
40.7
11
Aluminum
unbroken
265.9
12
Aluminum
broken
166.7
13
Al(grooved)
broken
77.4
14
Al(grooved)
unbroken
440.1
15
Aluminum
broken
210.4
|
This invention is an architectural glazing structure for exterior mounting that is a glass laminate having enhanced resistance to being pulled from a frame upon being subjected to severe positive and/or negative pressure loads. This invention is particularly suitable for architectural structures having windows that can be subjected to the extreme conditions prevalent in a hurricane, or window that can be placed under severe stress from repeated forceful blows to the laminate.
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RELATED APPLICATIONS
This application derives benefit from U.S. Provisional Application No. 60/909,472, filed Apr. 1, 2007.
FIELD
The described devices are spinal implants that may be surgically implanted into the spine to replace damaged or diseased discs using a posterior approach. The discs are prosthetic devices that approach or mimic the physiological motion and reaction of the natural disc.
BACKGROUND
The intervertebral disc is an anatomically and functionally complex joint. The intervertebral disc is composed of three component structures: (1) the nucleus pulposus; (2) the annulus fibrosus; and (3) the vertebral end plates. The biomedical composition and anatomical arrangements within these component structures are related to the biomechanical function of the disc.
The spinal disc may be displaced or damaged due to trauma or a disease process. If displacement or damage occurs, the nucleus pulposus may herniate and protrude into the vertebral canal or intervertebral foramen. Such deformation is known as herniated or slipped disc. A herniated or slipped disc may press upon the spinal nerve that exits the vertebral canal through the partially obstructed foramen, causing pain or paralysis in the area of its distribution.
To alleviate this condition, it may be necessary to remove the involved disc surgically and fuse the two adjacent vertebrae. In this procedure, a spacer is inserted in the place originally occupied by the disc and the spacer is secured between the neighboring vertebrae by the screws and plates or rods attached to the vertebrae. Despite the excellent short-term results of such a “spinal fusion” for traumatic and degenerative spinal disorders, long-term studies have shown that alteration of the biomechanical environment leads to degenerative changes particularly at adjacent mobile segments. The adjacent discs have increased motion and stress due to the increased stiffness of the fused segment. In the long term, this change in the mechanics of the motion of the spine causes these adjacent discs to degenerate.
Artificial intervertebral replacement discs may be used as an alternative to spinal fusion.
SUMMARY
Prosthetic intervertebral discs and methods for using such discs are described. The subject prosthetic discs include an upper end plate, a lower end plate, and a compressible core member disposed between the two end plates. The compressible core may be introduced between the two end plates after the end plates have been placed in the intervertebral space formed after the natural disc has been removed. The described prosthetic discs have shapes, sizes, and other features that are particularly suited for implantation using minimally invasive surgical procedures, particularly from a posterior approach.
In one variation, the described prosthetic discs include top and bottom end plates separated by one or more compressible core members. The two plates may be held together by at least one fiber wound around at least one region of the top end plate and at least one region of the bottom end plate. The described discs may include integrated vertebral body fixation elements. When considering a lumbar disc replacement from the posterior access, the two plates are preferably elongated, having a length that is substantially greater than its width. Typically, the dimensions of the prosthetic discs range in height from 8 mm to 15 mm; the width ranges from 6 mm to 13 mm. The height of the prosthetic discs ranges from 9 mm to 11 mm. The widths of the disc may be 10 mm to 12 mm. The length of the prosthetic discs may range from 18 mm to 30 mm, perhaps 24 mm to 28 mm. Typical shapes include oblong, bullet-shaped, lozenge-shaped, rectangular, or the like
The described disc structures may be held together by at least one fiber wound around at least one region of the upper end plate and at least one region of the lower end plate. The fibers are generally high tenacity fibers with a high modulus of elasticity. The elastic properties of the fibers, as well as factors such as the number of fibers used, the thickness of the fibers, the number of layers of fiber windings in the disc, the tension applied to each layer, and the crossing pattern of the fiber windings enable the prosthetic disc structure to mimic the functional characteristics and biomechanics of a normal-functioning, natural disc.
A number of conventional surgical approaches may be used to place a pair of prosthetic discs. Those approaches include a modified posterior lumbar interbody fusion (PLIF) and a modified transforaminal lumbar interbody fusion (TLIF) procedures. We also describe apparatus and methods for implanting prosthetic intervertebral discs using minimally invasive surgical procedures. In one variation, the apparatus includes a pair of cannulae that are inserted posteriorly, side-by-side, to gain access to the spinal column at the disc space. A pair of prosthetic discs may then be implanted by way of the cannulae to be located between two vertebral bodies in the spinal column.
The prosthetic discs may be configured by selection of sizes and structures suitable for implantation by minimally invasive procedures.
Other and additional devices, apparatus, structures, and methods are described by reference to the drawings and detailed descriptions below.
BRIEF DESCRIPTION OF THE DRAWINGS
The Figures contained herein are not necessarily drawn to scale. Some components and features may be exaggerated for clarity.
FIG. 1 shows a method for placement of prosthetic intervertebral discs using a posterior approach.
FIG. 2 is a perspective view of one variation of my prosthetic disc.
FIG. 3 is a perspective view of a core member insertable between end plates as a part of the variation of the prosthetic disc shown in FIG. 2 .
FIG. 4 is a side view of an insertion tool for my prosthetic disc.
FIG. 5 is a cross section, side view of one variation of an end plate.
FIG. 6 is a cross section, side view of the compressible core between two end plates as shown in FIG. 5 .
FIG. 7 is a cross section, side view of another variation of an end plate.
FIG. 8 is a cross section, side view of the compressible core between two end plates as shown in FIG. 7 .
FIGS. 9A and 9B schematically illustrate a method for extending an anchor into adjacent vertebral bone.
FIG. 10 schematically illustrate a method for implanting the described prosthetic discs.
DETAILED DESCRIPTION
Described below are prosthetic intervertebral discs, methods of using such discs, apparatus for implanting such discs, and methods for implanting such discs. It is to be understood that the prosthetic intervertebral discs, implantation apparatus, and methods are not limited to the particular embodiments described, as these may, of course, vary. It is also to be understood that the terminology used here is only for the purpose of describing particular embodiments, and is not intended to be limiting in any way.
Insertion of the prosthetic discs may be approached using modified conventional procedures, such as a posterior lumbar interbody fusion (PLIF) or transforaminal lumbar interbody fusion (TLIF). In the modified PLIF procedure, the spine is approached via midline incision in the back. The erector spinae muscles are stripped bilaterally from the vertebral lamina at the required levels. A laminectomy is then performed to further allow visualization of the nerve roots. A partial facetectomy may also be performed to facilitate exposure. The nerve roots are retracted to one side and a discectomy is performed. Optionally, a chisel may then used to cut one or more grooves in the vertebral end plates to accept the fixation components on the prostheses. Appropriately-sized prostheses may then be inserted into the intervertebral space on either side of the vertebral canal.
In a modified TLIF procedure, the approach is also posterior, but differs from the PLIF procedure in that an entire facet joint is removed and the access is only on one side of the vertebral body. After the facetectomy, the discectomy is performed. Again, a chisel may be used to create on or more grooves in the vertebral end plates to cooperatively accept the fixation components located on each prosthesis. The prosthesis discs may then be inserted into the intervertebral space. One prosthesis may be moved to the contralateral side of the access and then a second prosthesis then inserted on the access side.
It should be apparent that we refer to these procedures as “modified” in that neither procedure is used to “fuse” the two adjacent vertebrae.
FIG. 1 shows a top, cross section view of a spine ( 100 ), sectioned across an intervertebral disc ( 102 ). This Figure depicts a minimally invasive surgical procedure for implanting a pair of intervertebral discs in an intervertebral region formed by the removal of a natural disc. This minimally invasive surgical implantation method is performed using a posterior approach, rather than the conventional anterior lumbar disc replacement surgery or the modified PLIF and TLIF procedures described above.
In FIG. 1 , two cannulae ( 104 ) are inserted posteriorly, through the skin ( 107 ), to provide access to the spinal column. More particularly, a small incision is made and a pair of access windows created through the lamina ( 106 ) of one of the vertebrae ( 108 ) on each side of the vertebral canal ( 110 ) to access the natural vertebral disc. The spinal cord ( 112 ) and nerve roots are avoided or moved to provide access. Once access is obtained, the two cannulae ( 104 ) are inserted. The cannulae ( 104 ) may be used as access passageways in removing the natural disc with conventional surgical tools. Alternatively, the natural disc may be removed prior to insertion of the cannulae. The cannulae are also used to introduce the prosthetic intervertebral discs ( 114 ) to the intervertebral region.
The described prosthetic discs are of a design and capability that they may be employed at more than one level, i.e., disc location, in the spine. Specifically, several natural discs may be replaced with my prosthetic discs. As will be described in greater detail below, each such level will be implanted with at least two of my discs. Kits, containing two of my discs for a single disc replacement or four of my discs for replacement of discs at two levels in the spine, perhaps with sterile packaging are contemplated. Such kits may also contain one or more cannulae having a central opening allowing passage and implantation of my discs.
Once the natural disc has been removed and the cannulae ( 104 ) located in place, a pair of prosthetic discs ( 114 ) is implanted between adjacent vertebral bodies. The prosthetic discs have a shape and size suitable making them suitable for use with (or adapted for) various minimally invasive procedures. The discs may have a shape such as the elongated one-piece prosthetic discs described below.
A prosthetic disc ( 114 ) is guided through each of the cannula such that each of the prosthetic discs ( 114 ) is implanted between the two adjacent vertebral bodies. The two prosthetic discs ( 114 ) may be located side-by-side and spaced slightly apart, as viewed from above. Optionally, prior to implantation, grooves may be formed on the internal surfaces of one or both of the vertebral bodies in order to engage anchoring components or features located on or integral with the prosthetic discs ( 114 ). The grooves may be formed using a chisel tool adapted for use with the minimally invasive procedure, i.e., adapted to extend through a relatively small access space (such as the tunnel-like opening found in through the cannulae) and to chisel the noted grooves within the intervertebral space present after removal of the natural disc.
These discs may be used as shown in FIG. 1 or, optionally, they may be implanted with an additional prosthetic disc or discs, perhaps in the position shown for auxiliary disc ( 116 ).
Additional prosthetic discs may also be implanted in order to obtain desired performance characteristics, and the implanted discs may be implanted in a variety of different relative orientations within the intervertebral space. In addition, the multiple prosthetic discs may each have different performance characteristics. For example, a prosthetic disc to be implanted in the central portion of the intervertebral space may be configured to be more resistant to compression than one or more prosthetic discs that are implanted nearer the outer edge of the intervertebral space. For instance, the stiffness of the outer discs (e.g., 114 ) may each be configured such that those outer discs exhibit approximately 5% to 80% of the stiffness of the central disc ( 116 ), perhaps in the range of about 30% to 60% of the central disc ( 116 ) stiffness. Other performance characteristics may be varied as well.
This description may describe a number of variations of prosthetic intervertebral discs. By “prosthetic intervertebral disc” is meant an artificial or manmade device that is so configured or shaped that it may be employed as a total or partial replacement of an intervertebral disc in the spine of a vertebrate organism, e.g., a mammal, such as a human. The described prosthetic intervertebral discs have dimensions that permit them, either alone or in combination with one or more other prosthetic discs, to substantially occupy the space between two adjacent vertebral bodies that is present when the naturally occurring disc between the two adjacent bodies is removed, i.e., a void disc space. By “substantially occupy” is meant that, in the aggregate, the discs occupy at least about 30% by surface area, perhaps at least about 80% by surface area or more. The subject discs may have a roughly bullet or lozenge shaped structure adapted to facilitate implantation by minimally invasive surgical procedures.
The discs may include both an upper (or top) and lower (or bottom) end plate, where the upper and lower end plates are separated from each other by a compressible element such as one or more core members, where the combination structure of the end plates and compressible element provides a prosthetic disc that functionally approaches or closely mimics a natural disc. The top and bottom end plates may be held together by at least one fiber attached to or wound around at least one portion of each of the top and bottom end plates. As such, the two end plates (or planar substrates) are held to each other by one or more fibers that are attached to or wrapped around at least one domain, portion, or area of the upper end plate and lower end plate such that the plates are joined to each other.
FIG. 2 shows a variation of my prosthetic intervertebral disc ( 200 ). This variation comprises an upper end plate ( 202 ) and a lower end plate ( 204 ) separated by a compressible core ( 206 ). As discussed below in more detail, the compressible core ( 206 ) may comprise one or more core members (not shown) and be bounded by one or more fibers ( 207 ) extending between the upper end plate ( 202 ) and the lower end plate ( 204 ). I also refer to the upper and lower end plates as the first and second end plates since the relative upper and lower positions of the end plates do not affect the operation of my discs. The upper and lower end plates ( 202 , 204 ) may include apertures ( 208 ), through which the fibers ( 207 ) may pass. The shallow trough or depression ( 209 ) is used for direction of the insertable, compressible core ( 206 ) onto its final site from exterior to the end plate subcomponent assembly. Other components (woven or nonwoven fabrics, wires, etc.) may be used in functional substitution for the fibers ( 207 ). As may be apparent, this prosthetic disc is implanted in the following way: An “end plate subcomponent assembly,” a low profile assembly made up of the upper and lower end plates ( 202 , 204 ) and the in-place fibers ( 207 ) and having the trough or guideway ( 209 ), is first placed in the intervertebral space. The compressible core ( 206 ) is then positioned in the guideway ( 209 ) and pushed into the space between the end plates ( 202 , 204 ) thereby expanding the disc assembly in situ.
The discs may also include fibers ( 207 ) wound between and connecting the upper end plate ( 202 ) to the lower end plate ( 204 ). These fibers ( 207 ) may extend through a plurality of openings or apertures ( 208 ) formed on portions of each of the upper and lower end plates ( 202 , 204 ). Thus, a fiber ( 207 ) extends between the pair of end plates ( 202 , 204 ), and extends up through a first aperture ( 208 ) in the upper end plate ( 202 ) and back down through an adjacent aperture ( 208 ) in the upper end plate ( 202 ). The fibers ( 207 ) may not be tightly wound, thereby allowing a degree of axial rotation, bending, flexion, and extension by and between the end plates. The amount of axial rotation generally is in the range from about 0° to about 15°, perhaps from about 2° to 10°. The amount of bending generally has a range from about 0° to about 18°, perhaps from about 2° to 15°. The amount of flexion and extension generally has a range from about 0° to about 25°, perhaps from about 3° to 15°. Of course, the fibers ( 207 ) may be more or less tightly wound to vary the resultant values of these rotational values. An annular capsule may be included in the space between the upper and lower end plates ( 202 , 204 ), surrounding the compressible core ( 206 ).
FIG. 3 is a perspective view of the insertable, compressible core ( 206 ) having an insertion support ( 210 ) that may be used in introducing the core ( 206 ) into the end plate subcomponent assembly after that subassembly has been introduced into an intervertebral space created when a natural disc has been removed.
FIG. 4 shows, in a schematic way, a combination of an insertion tool ( 214 ) and a collapsed end plate subcomponent assembly ( 216 ). The insertion tool ( 214 ) supports the upper and lower end plates ( 202 , 204 ) via insertion into openings ( 211 ). The insertable disc ( 206 ), with its support member ( 210 ) is advanced into the collapsed end plate subcomponent assembly ( 216 ) by use of a screw ( 218 ). When the insertable disc ( 206 ) is fully advanced into the collapsed end plate subcomponent assembly ( 216 ), the full height disc (as shown in FIG. 2 ) is achieved.
Various profiles of end plates may be used to provide various final disc profiles. For instance, FIG. 5 shows a side view, cross section of an end plate ( 300 ) with a trough or runway ( 302 ) for passage of the compressible core to its final site.
FIG. 6 shows a side view, cross section of the final profile of a prosthetic disc ( 304 ) after insertion of the compressible core ( 306 ) between the two end plates ( 300 ). The final shape may be used to provide a specific lordotic or kyphotic angle to the disc ( 304 ) while preserving significant inter-end-plate spacing. The low profile, collapsed, end plate subcomponent assembly ( 216 ) also allows entry into the intervertebral space through small access openings as might be used with a posterior approach.
FIG. 7 shows, in cross section, side view, another profile of an end plate ( 308 ) also having a trough or route ( 310 ) for passage of the compressible core. FIG. 8 , in turn, shows, in cross-section, side view, the expanded profile of the resulting prosthetic disc ( 314 ). In this instance, the ramps are angled to provide a simple pathway for the compressible core ( 316 ) to its final site. The profile of the disc ( 314 ) has generally parallel surfaces facing the vertebrae.
The end plates may be planar substrates having a length of from about 12 mm to about 45 mm, such as from about 13 mm to about 44 mm, a width of from about 11 mm to about 28 mm, such as from about 12 mm to about 25 mm, and a thickness of from about 0.5 mm to about 5 mm, such as from about 1 mm to about 3 mm. The top and bottom end plates are fabricated or formed from a physiologically acceptable material that provides for the requisite mechanical properties, primarily structural rigidity and durability. Representative materials from which the end plates may be fabricated are known to those of skill in the art and include: metals such as titanium, titanium alloys, stainless steel, cobalt/chromium, etc.; plastics such as polyethylene with ultra high molar mass (molecular weight) (UHMW-PE), polyether ether ketone (PEEK), etc.; ceramics; graphite; etc.
The lateral, or horizontal, surface area of each of the end plates ( 202 , 204 )—i.e., the area of the disc surfaces that engage the vertebral bodies—is substantially larger than the cross-sectional surface area of the core member or members. The cross-sectional surface area of the core member or members may be from about 5% to about 80% of the cross-sectional area of a given end plate ( 202 , 204 ), perhaps from about 10% to about 60%, or from about 15% to about 50%. In this way, for a given compressible core ( 206 ) having sufficient compression, flexion, extension, rotation, and other performance characteristics but having a relatively small cross-sectional size, the core member may be used to support end plates having a relatively larger cross-sectional size in order to help prevent subsidence into the vertebral body surfaces. In the variations described here, the compressible core ( 206 ) and end plates ( 202 , 204 ) also have a size that is appropriate for or adapted for implantation by way of posterior access or minimally invasive surgical procedures, such as those described above.
FIGS. 9A and 9B provide a cross-section, side-view of an extendible anchoring feature ( 350 ) that is rotated into position by placement of the core member ( 352 ). The depicted anchor may rotate around a hinge-pin ( 354 ) or by mere placement of the anchor ( 350 ) in a properly shaped opening.
The surfaces of the upper and lower end plates, those surfaces in contact with and eventually adherent to the respective opposed bony surfaces of the upper and lower vertebral bodies, may have one or more anchoring or fixation components or mechanism (such as those discussed in respect to FIGS. 9A and 9B ) for securing those end plates to the vertebral bodies. For example, the anchoring feature may be one or more “keels,” a fin-like extension often having a substantially triangular cross-section and having a sequence of exterior barbs or serrations. This anchoring component is intended to cooperatively engage a mating groove that is formed on the surface of the vertebral body and to thereby secure the end plate to its respective vertebral body. The serrations enhance the ability of the anchoring feature to engage the vertebral body.
Further, this “keel” variation of the anchoring component may include one or more holes, slots, ridges, grooves, indentations, or raised surfaces to further assist in anchoring the disc to the associated vertebra. These physical features will so assist by allowing for bony ingrowth. Each end plate may have a different number of anchoring components, and those anchoring features may have a different orientation on each end plate. The number of anchoring features generally ranges in number from about 0 to about 500, perhaps from about 1 to 10. Alternatively, another fixation or anchoring mechanism may be used, such as ridges, knurled surfaces, serrations, or the like. In some variations, the discs will have no external fixation mechanism. In such variations, the discs are held in place laterally by the friction forces between the disc and the vertebral bodies.
Further, each of the described variations may additionally include a porous covering or layer (e.g., sprayed Ti metal) allowing boney ingrowth and may include some osteogenic materials.
FIG. 10 , step (a), shows placement of a collapsed end plate subcomponent assembly ( 400 ) into the intervertebral space ( 402 ) between an upper vertebra ( 404 ) and the adjacent lower vertebra ( 406 ). The placement tool has been omitted for clarity. The end plate subcomponent assembly ( 400 ) has been passed through the cannula ( 410 ) to the implantation site. The insertable core ( 412 ) is shown approaching the end plate subcomponent assembly ( 400 ).
FIG. 10 , step (b), shows the implanted disc ( 416 ) after expansion. The cannula ( 410 ) and the core placement tool ( 418 ) are being removed.
Each of the described prosthetic discs depicted in the Figures has a greater length than width. The aspect ratio (length:width) of the discs may be about 1.5 to 5.0, perhaps about 2.0 to 4.0, or about 2.5 to 3.5. Exemplary shapes to provide these relative dimensions include rectangular, oval, bullet-shaped, lozenge-shaped, and others. These shapes facilitate implantation of the discs by the minimally invasive procedures described above.
As noted above, in the variations shown herein, the upper end plate and lower end plate may each contain a plurality of apertures through which the fibers may be passed through or wound, as shown. The actual number of apertures contained on an end plate is variable. Increasing the number of apertures allows an increase in the circumferential density of the fibers holding the end plates together. The number of apertures may range from about 3 to 100, perhaps in the range of 10 to 30. In addition, the shape of the apertures may be selected so as to provide a variable width along the length of the aperture. For example, the width of the apertures may taper from a wider inner end to a narrow outer end, or visa versa. Additionally, the fibers may be wound multiple times within the same aperture, thereby increasing the radial density of the fibers. In each case, this improves the wear resistance and increases the torsional and flexural stiffness of the prosthetic disc, thereby further approximating natural disc stiffness. In addition, the fibers may be passed through or wound on each aperture, or only on selected apertures, as needed. The fibers may be wound in a uni-directional manner, where the fibers are wound in the same direction, e.g., clockwise, which closely mimics natural annular fibers found in a natural disc, or the fibers may be wound bi-directionally. Other winding patterns, both single and multi-directional, may also be used.
The apertures provided in the various end plates discussed here, may be of a number of shapes. Such aperture shapes include slots with constant width, slots with varying width, openings that are substantially round, oval, square, rectangular, etc. Elongated apertures may be radially situated, circumferentially situated, spirally located, or combinations of these shapes. More than one shape may be utilized in a single end plate.
One purpose of the fibers is to hold the upper and lower end plates together and to limit the range-of-motion to mimic or at least to approach the range-of-motion of a natural disc. The fibers may comprise high tenacity fibers having a high modulus of elasticity, for example, at least about 100 MPa, perhaps at least about 500 MPa. By high tenacity fibers is meant fibers able to withstand a longitudinal stress of at least 50 MPa, and perhaps at least 250 MPa, without tearing. The fibers 207 are generally elongate fibers having a diameter that ranges from about 100 μm to about 1000 μm, and preferably about 200 μm to about 400 μm. The fibrous components may be single strands or, more typically, multi-strand assemblages. Optionally, the fibers may be injection molded or otherwise coated with an elastomer to encapsulate the fibers, thereby providing protection from tissue ingrowth and improving torsional and flexural stiffness. The fibers may be coated with one or more other materials to improve fiber stiffness and wear. Additionally, the core may be injected with a wetting agent such as saline to wet the fibers and facilitate the mimicking of the viscoelastic properties of a natural disc. The fibers may comprise a single or multiple component fibers.
The fibers may be fabricated from any suitable material. Examples of suitable materials include polyesters (e.g., Dacron® or the Nylons), polyolefins such as polyethylene, polypropylene, low-density and high density polyethylenes, linear low-density polyethylene, polybutene, and mixtures and alloys of these polymers. HDPE and UHMWPE are especially suitable. Also suitable are various polyaramids, poly-paraphenylene terephthalamide (e.g., Kevlar®), carbon or glass fibers, various stainless steels and superelastic alloys (such as nitinol), polyethylene terephthalate (PET), acrylic polymers, methacrylic polymers, polyurethanes, polyureas, other polyolefins (such as polypropylene and other blends and olefinic copolymers), halogenated polyolefins, polysaccharides, vinylic polymers, polyphosphazene, polysiloxanes, liquid crystal polymers such as those available under the tradename VECTRA, polyfluorocarbons such as polytetrafluoroethylene and e-PTFE, and the like.
The fibers may be terminated on an end plate in a variety of ways. For instance, the fiber may be terminated by tying a knot in the fiber on the superior or inferior surface of an end plate. Alternatively, the fibers may be terminated on an end plate by slipping the terminal end of the fiber into an aperture on an edge of an end plate, similar to the manner in which thread is retained on a thread spool. The aperture may hold the fiber with a crimp of the aperture structure itself, or by an additional retainer such as a ferrule crimp. As a further alternative, tab-like crimps may be machined into or welded onto the end plate structure to secure the terminal end of the fiber. The fiber may then be closed within the crimp to secure it. As a still further alternative, a polymer may be used to secure the fiber to the end plate by welding, including adhesives or thermal bonding. That terminating polymer may be of the same material as the fiber (e.g., UHMWPE, PE, PET, or the other materials listed above). Still further, the fiber may be retained on the end plates by crimping a cross-member to the fiber creating a T-joint, or by crimping a ball to the fiber to create a ball joint.
The core members provide support to and maintain the relative spacing between the upper and lower end plates. The core members may comprise one or more relatively compliant materials. In particular, the compressible core members in this variation and the others discussed herein, may comprise a thermoplastic elastomer (TPE) such as a polycarbonate-urethane TPE having, e.g., a Shore value of 50 D to 60 D, e.g. 55 D. An example of such a material is the commercially available TPE, BIONATE. Shore hardness is often used to specify flexibility or flexural modulus for elastomers.
We have had success with core members comprising TPE that are compression molded at a moderate temperature from an extruded plug of the material. For instance, with the polycarbonate-urethane TPE mentioned above, a selected amount of the polymer is introduced into a closed mold upon which a substantial pressure may be applied, while heat is applied. The TPE amount is selected to produce a compression member having a specific height. The pressure is applied for 8-15 hours at a temperature of 70°-90° C., typically about 12 hours at 80° C.
Other examples of suitable representative elastomeric materials include silicone, polyurethanes, or polyester (e.g., Hytrel®).
Compliant polyurethane elastomers are discussed generally in, M. Szycher, J. Biomater. Appl. “Biostability of polyurethane elastomers: a critical review”, 3(2):297 402 (1988); A. Coury, et al., “Factors and interactions affecting the performance of polyurethane elastomers in medical devices”, J. Biomater. Appl. 3(2):130 179 (1988); and Pavlova M, et al., “Biocompatible and biodegradable polyurethane polymers”, Biomaterials 14(13):1024 1029 (1993). Examples of suitable polyurethane elastomers include aliphatic polyurethanes, segmented polyurethanes, hydrophilic polyurethanes, polyether-urethane, polycarbonate-urethane, and silicone-polyether-urethane.
Other suitable elastomers include various polysiloxanes (or silicones), copolymers of silicone and polyurethane, polyolefins, thermoplastic elastomers (TPE's) such as atactic polypropylene, block copolymers of styrene and butadiene (e.g., SBS rubbers), polyisobutylene, and polyisoprene, neoprene, polynitriles, artificial rubbers such as produced from copolymers produced of 1-hexene and 5-methyl-1,4-hexadiene.
One variant of the construction for the core member comprises a nucleus formed of a hydrogel and an elastomer reinforced fiber annulus.
For example, the nucleus, the central portion of the core member, may comprise a hydrogel material. Hydrogels are water-swellable or water-swollen polymeric materials typically having structures defined either by a crosslinked or an interpenetrating network of hydrophilic homopolymers or copolymers. In the case of physical crosslinking, the linkages may take the form of entanglements, crystallites, or hydrogen-bonded structures to provide structure and physical integrity to the polymeric network.
Suitable hydrogels may be formulated from a variety of hydrophilic polymers and copolymers including polyvinyl alcohol, polyethylene glycol, polyvinyl pyrrolidone, polyethylene oxide, polyacrylamide, polyurethane, polyethylene oxide-based polyurethane, and polyhydroxyethyl methacrylate, and copolymers and mixtures of the foregoing.
Silicone-base hydrogels are also suitable. Silicone hydrogels may be prepared by polymerizing a mixture of monomers including at least one silicone-containing monomer and or oligomer and at least one hydrophilic co-monomer such as N-vinyl pyrrolidone (NVP), N-vinylacetamide, N-vinyl-N-methyl acetamide, N-vinyl-N-ethyl acetamide, N-vinylformamide, N-vinyl-N-ethyl formamide, N-vinylformamide, 2-hydroxyethyl-vinyl carbonate, and 2-hydroxyethyl-vinyl carbamate (beta-alanine).
The annulus may comprise an elastomer, such as those discussed just above, reinforced with a fiber.
The shape of each of the core members may be cylindrical or have an oval cross section, although the shape (as well as the materials making up the core member and the core member size) may be varied to obtain desired physical or performance properties. For example, the core member's shape, size, and materials will directly affect the degree of flexion, extension, lateral bending, and axial rotation of the prosthetic disc.
Where a range of values is provided, it is understood that each intervening value within the range, to the tenth of the unit of the lower limit (unless the context clearly dictates otherwise), between the upper and lower limit of that range and any other stated or intervening value in that stated range is described. The upper and lower limits of these smaller ranges may independently be included in the smaller ranges is also described, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also described.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the medical devices art. Although methods and materials similar or equivalent to those described here may also be used in the practice or testing of the described devices and methods, the preferred methods and materials are described in this document. All publications mentioned herein are incorporated herein by reference to disclose and describe the methods and/or materials in connection with which the publications are cited.
It must be noted that as used herein and in the appended claims, the singular forms “a”, “an”, and “the” include plural referents unless the context clearly dictates otherwise.
As will be apparent to those of skill in the art upon reading this disclosure, each of the individual variations described and illustrated herein has discrete components and features which may be readily separated from or combined with the features of any of the other several embodiments without departing from the scope or spirit of this disclosure. For example, and without limitation, several of the variations described here include descriptions of anchoring features, protective capsules, fiber windings, and protective covers covering exposed fibers for integrated end plates. It is expressly contemplated that these features may be incorporated (or not) into those variations in which they are not shown or described.
All patents, patent applications, and other publications mentioned herein are hereby incorporated herein by reference in their entireties. The patents, applications, and publications discussed herein are provided solely for their disclosure prior to the filing date of the present application. Nothing herein is to be construed as an admission that contents of those patents, applications, and publications are “prior” as that term is used in the Patent Law.
The preceding merely illustrates the principles of the invention. It will be appreciated that those skilled in the art will be able to devise various arrangements which, although not explicitly described or shown herein, embody the principles otherwise described here and are included within its spirit and scope. Furthermore, all examples and conditional language recited herein are principally intended to aid the reader in understanding the described principles of my devices and methods. Moreover, all statements herein reciting principles, aspects, and variation as well as specific examples thereof, are intended to encompass both structural and functional equivalents. Additionally, it is intended that such equivalents include both currently known equivalents and equivalents developed in the future, i.e., any elements developed that perform the same function, regardless of structure.
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The described devices are spinal implants that may be surgically implanted into the spine to replace damaged or diseased discs using a posterior approach. The discs are prosthetic devices that approach or mimic the physiological motion and reaction of the natural disc.
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FIELD OF THE INVENTION
This invention relates to sheltering structures particularly for protection against hurricanes, tornadoes, squalls and the like.
BACKGROUND OF THE INVENTION
Storms, hurricanes, typhoons, tornadoes and the like are devastating to building structures. In the United States, wind damage to building structures result in numerous injuries and deaths each year. Moreover, these storms also cause millions of dollars in property losses each year. Hurricane Andrew, which struck Florida in 1992, caused numerous injuries and deaths as well as an estimated $100 million in damages to residential homes alone. Even in the heaviest hit areas in Florida, however, where wind speeds exceeded 150 Knots, reinforced structures withstood the wind far better than non-reinforced structures.
Much of the wind damage to the structures occurred at “weak links” of the building structure, namely the junction between the roof and vertical support structures, i.e., walls. Another “weak link” of the building structures most affected by the storm, was the nailedsecured joints, i.e., where the aluminum siding attached to the outside of the structure or a joint securing one piece of material to another. When wind is able to get under these “weak links,” as one is weakened, additional pieces that are attached are also weakened, causing the integrity of the structure to be compromised and sometimes totally destroyed.
In addition to winds causing damage to the outside of a structure, high velocity winds can also destroy a structure from the inside out. For example, if any of the openings in a structure are breached, the high velocity force of the winds entering the structure create positive pressure against the roof weakening the structure. At the same time the high velocity of the winds streaming over the roof on the outside creates a suction. This combination of internal positive pressure and external suction will inevitably tare the roof off of the house.
In an effort to prevent the breach of openings in the structure as well as, to protect windows and doors against shattering from debris colliding at high velocity, homeowners and businesses usually board-up openings with various types of panels when there is a threat that the weather pattern will bring high velocity winds. In the case of certain types of wind driven storms, i.e. squalls and tornadoes, however, the landowner may not have sufficient time to secure windows and doors from eminent destruction. Thus, in this situation the structure is left unprotected and is vulnerable to the force of the high velocity winds generated by the fast approaching weather pattern.
In cases where landowners have enough warning and are able to protect the openings in the structure, in many instances, corrugated metal panels are fastened over the openings by top and bottom rails which remain in place at all times even in non-hurricane seasons. Of course, the rails are very unsightly and distract from the clean lines of a structure. Other panels are fastened to the openings by screws screwed into permanent anchors which are placed into the flush walls surrounding the openings. These again are permanent installations that are very unsightly, are subject to corrosion, and potentially represent another “weak link” that may be affected by high velocity winds.
In addition, hurricane force winds of one hundred miles/hr and higher are known to set up harmonic vibrations that will result in rattling loose the above described installation because of the metal to metal contact between the fasteners and the corrugated metal panels. Further, anchors of various types are also prone to failure because of progressive corrosion in coastal areas. In addition, anchors driven into blocks which are hollow and only ½ inch thick are inadequate to hold a large force form shaking loose during a major storm.
In a residential setting where the resident decides to nail protective covers, i.e., plywood sheets, to the side of the house, most homeowner have no experience in nailing into concrete and any nailing close to the edge of an opening will simply break the block away behind the panel and any anticipated holding power is greatly diminished from this common mistake. Even assuming that the homeowner is able to nail the protective covers to the side of the house, there will always be at least one opening unprotected so as to provide for egress. This one opening when breached is enough to cause the internal positive pressure discussed above. Moreover, the nailed protective covers add additional “weak links” to the structure which are vulnerable to high velocity winds. In addition, although the techniques discussed above may provide some protection to a structure against high wind velocity, these techniques do not protect the walls and roofs of the structure. These sections of the structure remain vulnerable to the high velocity winds.
In view of the problems associated with the foregoing, there is a need for a protection system for building structures that is easy to implement, can withstand high winds, reduce the number of “weak links” in a structure, and protect a structure against destruction during high wind situations.
SUMMARY OF THE INVENTION
The present invention provides an interlocking roof and wall system for protecting a building structure. The interlocking roof and protective wall system comprises a plurality of supports that form downward facing open channels which are either already attached o an overhang or for existing roofs are attachable to the overhang. For the purpose of this application the term “interlocking” means any system where one piece fits into another. The plurality of protective walls that interlock into the overhang surround the building structure, a portion of the walls fit into the channel formed by the supports. The interlocking roof and protective walls can be secured in place by additional mechanisms or can simply lie within one another.
Surrounding at least a portion of the plurality of protective walls is a plurality of retainer walls. The retainer walls form a cavity which is at least partially below grade wherein the protective walls are positioned within. At the base of the protective walls is a hydraulic lifting system that is in contact with a portion of the protective walls. The hydraulic lifting system is actuable to extend a member which pushes against the protective walls, thereby lifting the protective walls out of the cavity formed by the retainer walls. The protective walls are lifted to a height whereby at least a portion of the protective walls interlock in the downward facing open channel attached to the overhang of the roof.
After the storm is over, the protective walls can be lowered back into the cavity formed by the retainer walls by releasing the hydraulic fluid from the pressurized cylinders, causing the protective walls to slowly disengage from the interlocking supports and rest in the cavity.
This system can be installed at the time of construction or can be retrofitted to most existing building structures. It is understood that some building structures may need additional construction, i.e., building an overhang, for the system to work.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 illustrates a cross-section of a structure incorporating the protectable building system of one embodiment of the invention.
FIG. 2 illustrates a cross-section of a structure incorporating the protectable building system showing the hydraulic system of one embodiment of the invention.
FIG. 3 illustrates a cross-section of a structure incorporating the protectable building system showing the roof overhang support of one embodiment of the invention.
FIG. 4 illustrates cross-section of a structure incorporating the protectable building system of an alternative embodiment of the invention.
FIG. 5A is a cutaway view of a roller and ratchet mechanism of one embodiment of the invention.
FIG. 5B is a cutaway view of a roller and ratchet mechanism of an alternative embodiment of the invention incorporating a cross-sectional view of the roller and ratchet mechanism.
DETAILED DESCRIPTION OF THE INVENTION
According to one embodiment of the present invention, a protectable building system 10 that has the appearance of a conventional house is depicted in FIG. 1 . The protectable building system 10 may have a slab 15 foundation which is not required for the operation of the protectable building system, but is an easy construction method for building the structure. In addition to making construction easier, the slab 15 provides additional support for the protectable building 30 as well as protective walls 20 and 25 (described below).
The protectable building system 10 may be constructed on site, or may be a prefabricated modular design which is assembled on site. The protectable building system 10 is used as an illustrative example of the present invention which includes protectable building structures other than residential houses, such as commercial buildings.
Surrounding the protectable building structure 30 are protective walls 20 and 25 . Protective walls 20 and 25 are spaced far enough away from the protectable building 30 so that when the protective walls 20 and 25 are extended (described below) there is ample clearance of any projections extending from the protectable house i.e. window frames, extended bay windows, or air conditioners. The preferable space between the protectable building 30 and protective walls 20 and 25 is between about 1 to about 4 feet, most preferably between about 1 to about 2 feet.
The protective walls 20 and 25 are constructed from material that is strong enough to withstand forces placed on the walls by high velocity winds. The width of the protective walls 20 and 25 vary according to the material used for its construction. In other words, the stronger the material, the thinner the wall; the weaker the material, the thicker the wall. The combination of material and thickness used, however, must be able to withstand forces associated with a wind velocity up to about 85 mph, preferably up to about 100 mph, more preferably up to about 150 mph.
The height of the protective walls 20 and 25 vary with the height of the structure being protected. Preferably the protective walls are at least about 1 to about 3 feet higher than the height of the structure being protected. The portion of the wall in excess of the height of the structure remains below grade even when the protective walls 20 and 25 are fully extended (described below). The portion of the protective wall that remains below grade provides additional support to the protective walls. In other words, if the protectable building structure 30 is about 15 feet above grade, the protective walls 20 and 25 are about 16 to 18 feet height. When these walls are extended to reach the roof (as described below) at least about 1 to about 3 feet remains below grade as support.
In one embodiment, surrounding the protective walls 20 and 25 are first and second retainer walls 35 and 40 , respectively. The first retainer wall 35 is located closest to the protectable building structure 30 and second retainer wall 40 is furthest from the building structure 30 . The width of the cavity formed by the space between the first and second retainer walls is greater than the width of protective walls 20 and 25 so that the protective walls fit within the first and second retainer walls 35 and 40 . The first and second retainer walls 35 and 40 can be constructed from treated plywood, PVC, plastics, corrugated steel or the like. The number of retainer walls needed is directly proportional to the nuinber of protective walls needed to protect the building structure. In other words, if the size or shape of the structure requires additional protective walls, the number of retainer walls is also increased.
The protective walls 20 and 25 are in contact with a hydraulic system 45 which is used to raise the protective walls 20 and 25 towards the roof. The hydraulic system 45 exerts an upward force against a lifting plate 50 which is embedded at the base of protective walls 20 and 25 . The lifting plates 50 can be made of steel or any other material capable of enduring an upward force equal to or greater than the force exerted back on the plate by the weight of the wall. The hydraulic system 45 also includes at least two pressurizes cylinders shown in FIG. 2 . The pressurized cylinders may be located inside the protective walls or outside the protective walls. FIG. 2 illustrates hydraulic cylinders that are located inside the protective walls.
In FIG. 2 a pressurized cylinder 55 is shown in the unextended and extended view. The pressurized cylinder 55 shows the base 60 , a boom 65 , and a top 70 . The pressurized cylinders located within protective walls 20 and 25 do not require a lifting plate. The pressurized cylinder 55 , can be activated by either air or fluid. The boom 65 , whether located inside the protective walls or outside the protective walls, desirably has three stages and is capable of extending a height at least equal to the height of the protectable building structure 30 .
In one embodiment illustrated in FIG. 2, the pressurized cylinders are located outside the protective walls and the top 70 of boom 65 is anchored to the lifting plate 50 located at the bottom of the protective walls. The lifting plate located on the top portion of the pressurized cylinder is attached flush against the underside portion of the lifting plate 50 . Desirably, lifting plate 50 includes a depression into which the top portion of the pressurized cylinder 55 is attached. The depressed portion of the lifting plate 50 provides additional lateral strength to the connection between the pressurized cylinder 55 and lifting plate 50 . This connection prevents slippage of the pressurized cylinder 55 when the hydraulic system 45 is applying lifting forces to the lifting plate.
The hydraulic system also includes a pressurized hydraulic line 75 which extends from a pump 80 to an inlet valve 85 (FIG. 3) located at the base 60 of the pressurized cylinder 55 . At least four pressurized cylinders positioned beneath the protective walls 20 and 25 are required to lift the protective walls from the cavity to protect a four sided building structure. Additional protective walls and pressurized cylinders may be required to accommodate uniquely shaped structures, i.e., structures having a shape different than a square or a rectangle.
When the pump 80 is activated, fluid or air is pumped into the inlet valve 85 in the base 60 of the pressurized cylinder 55 and the boom 65 begins to rise. The boom 65 provides an upward vertical force on the lifting plate 50 , thereby lifting the protective wall above grade. In one embodiment, the hydraulic cylinders are equipped with the control valves that maintain the hydraulic cylinders at a predetermined height until the locking control valves are deactivated and the hydraulic cylinders lowered to a resting position. The pump 80 can be powered by electric and can be connected to a back-up 12-volt battery in case of power failure. In the alternative the pump can be powered by a gas generator.
FIG. 3 illustrates one embodiment where the roof 90 of the protectable building structure 30 has a overhang 95 . Attached to the underside of the overhang 95 is a support 100 forming a downward facing channel 105 . The downward facing channel 105 has a width that is greater than the width of the protective walls 20 and 25 so that the top portion of the protective walls fit within the channel 105 of the support 100 . In one embodiment, the top portion of the protective wall has a cut-away portion (not shown) that interlocks into the channel 105 of the support 100 whereby the outside portion of the support is flush with the outside portion of the protective walls 20 and 25 . This arrangement reduces the production of “weak links” discussed above, which in turn reduces the chance of high velocity winds can weakening the building structure. The supports 100 can be made of a reinforced material such as corrugated galvanized metals, reinforced wood, or the like. In any case, the supports 100 must be strong enough to both support the protective walls 20 and 25 and to prevent the roof from disconnecting from the building structure, when subjected to high velocity winds.
In one embodiment of the present invention, the supports 100 are located at the outermost portion of the overhang 95 . Positioning the supports 100 at the outermost portion of the overhang 95 reduces the amount of the overhang that is exposed to the high velocity winds once the protective walls 20 and 25 are in place. In other words, the outside surface of the protective walls 20 and 25 , once positioned into the supports 100 , sit flush against the rim of the overhang 90 thereby exposing little if any of the overhang 95 to the high velocity winds. Since winds can easily get under the rim of the overhang 95 and pry the roof from the building structure, reducing the exposure of the overhang 95 to the winds reduces yet another “weak link” in the building structure.
The supports may be equipped with a locking mechanism that interlocks the top portion of the protective walls into the supports. The locking mechanism (not shown) can be manually or automatically engaged once the top portion of the protective walls comes in contacts with the support. When fluid is drained from the hydraulic cylinders the locking mechanism can be manually or automatically disengaged so as to permit the protective walls to be lowered back into the cavity formed by the reinforced walls.
Since the protective walls 20 and 25 are usually heavy, one embodiment is equipped with one or more guide posts that are position in close proximately to the protective walls. These guide posts 110 shown in FIG. 4 provide strength and rigidity to the protective walls and are used to maintain the path of the walls as they are lifted and lowered. The guide posts 110 as well as the protective walls 20 and 25 are anchored in caissons 115 . Illustratively, the caissons 115 are concrete caissons made by pouring cement into cylindrical sona tubes made of waterproof cardboard which act as a mold and disintegrate over time.
The caissons 115 begin at the existing grade level and extend below ground a distance dictated by the soil density and size/height of the protective walls 20 and 25 . Preferably, the distance is at least about 2 to about 5 feet below the existing grade level. The soil and protective wall size also dictate the size of the caissons 105 as well as the guide posts 110 . Preferably, the diameter of the caissons 115 is about twice the diameter of the guide posts 110 . Illustratively the guide posts 110 are 4″×8″ steel H-beams which may be galvanized to prevent corrosion, and the diameter of the caissons 115 is about 16″, being twice the 8″ dimension of the guideposts 110 .
FIG. 5A illustrates one embodiment wherein the guide posts 110 work in conjunction with roller guides 120 and a ratchet mechanism 115 . The protective walls 20 and 25 have rollers 125 which roll along the guide posts 110 during vertical movement of the protective walls, i.e., when the hydraulic cylinders are activated. Below the rollers 125 , the ratchet mechanism 115 is located between the protective walls 20 and 25 and the guide post 110 . The ratchet mechanism 115 permits the protective walls 20 and 25 to rise along the guide posts 110 as the boom of the hydraulic cylinder is extended and prevents a accidental lowering of the protective walls. The roller 125 is attached to the outer surface of the protective walls 20 and 25 . The ratchet mechanism 115 has two parts. The first part is attached to the guide posts 110 and the outer surface of the protective walls and the second part is attached to the outer portion of the protective walls. Each guide post 110 has its own ratchet 115 and roller 125 mechanism. The rollers 125 roll along the larger section of the guide post 110 . The rollers 125 may be bolted or anchored into the protective walls 20 and 25 using bolts, two J-hooks or a single U-shaped J-hook (not shown). The rollers 125 maybe rubber, Teflon™, hard plastic or rubberized metal. Illustratively in FIG. 5B, the rollers 125 are located above the ratchet mechanism 115 . Alternatively, the rollers 125 may be located adjacent to the ratchet mechanism 115 . This allows the first part of the ratchet mechanism 115 to extend further up the guide post 110 , thus permitting the protective walls 20 and 25 to remain locked in place at a higher height. The ratchet mechanism 115 keeps the protective walls 20 and 25 in an elevated position after the protective walls have been raised by pressurized cylinders.
The first part of the ratchet mechanism 115 is attached to the guide post 110 via bolts, welding or the like. The first part of the ratchet mechanism 115 has fixed teeth 140 separated by segments. The second part of the ratchet mechanism 115 has a body which is attached, e.g., bolted, to the outer surface of the protective walls 20 and 25 with bolts. In addition, the second part of the ratchet mechanism 115 has a locking lever 130 which is attached to the body via a hinge 135 located at the top of the movable tooth 145 . The fixed teeth 140 of the first part mate with the movable teeth 145 of the second part to prevent a premature lowering of the protective walls 20 and 25 . In other words, the surfaces 155 of the movable teeth and the surfaces 145 of the fixed teeth 150 complement each other so as to temporarily lock together. This ratchet system allows the protective walls 20 and 25 to rise but prevent them from descending. Preferably, the surface 155 of the movable teeth 145 has a downward slant and the surface 150 of the fixed teeth 140 have an upward slant. This provides a better locking of the first and second parts of the ratchet when the surfaces 155 of the movable teeth 145 mate with the surfaces 150 of a fixed teeth 140 . In one embodiment, the movable teeth 145 of the second part are pushed forward by a spring loaded rod (not shown) which is attached to the back of the movable teeth 145 .
The ratchet mechanism 115 can also be equipped with a locking lever 130 that locks the ratchet mechanism 115 in place when the walls are stationary in the raised position. The locking lever 130 can be attached to an emergency locking lever release cord that releases the ratchet mechanism 115 when it is pulled away from the protective walls. In other words, the locking lever 130 disengages from the fixed teeth 140 and the protective walls 20 and 25 are free to move in the vertical position. Upon releasing the locking lever, fluid, i.e., gas or oil, can be released from the pressurized fluid resulting lowering of the protective walls into the cavity formed by the first and second retainer walls 35 and 40 .
The operation of the protective wall system is as follows. In the event of an approaching weather front with sustained winds greater than 50 mph, the hydraulic lifting system 45 can be activated to lift the protective walls 20 and 25 into position. When the hydraulic system is activated a pump, which is attached to the pressurized cylinders 55 via a pressurized hydraulic line 75 , begins to pump fluid into the pressurized cylinders 55 . The pump 80 is attached to a flow divider (not shown) by connecting lines. The flow divider evenly distributes the fluid pumped by the pump to the pressurized cylinders 55 . As the pressured cylinders begin to fill with fluid, the booms begin to extend out of the pressurized cylinders and exert an upward force on the protective walls. As shown in the figures, the boom 65 may be located within the protective walls 20 and 25 or positioned so that a portion of the boom 65 is in contact with a portion of the protective walls 20 and 25 . When the boom is outside the protective walls, the portion of the protective walls that experience the bulk of the stress due to the upward force is further supported by a lifting plate 50 . If the boom 65 is inside the protective wall, no lifting plate is necessary. As a result of this upward force, the protective walls 20 and 25 rise out of the cavity formed by the first and second retainer walls 30 and 40 . In one embodiment, the walls are guided by several guide posts 110 that provide support as well as guidance for the vertical movement of the rising walls. In another embodiment no guide posts are utilized.
When the protective walls 20 and 25 rise, the movable teeth 145 of the ratchet system attached to the guide posts 110 are pushed back toward the walls as it slides up the fixed teeth 140 . When the movable teeth 145 reaches over one of the fixed teeth 140 , the spring loaded rod pushes the movable teeth 145 forward toward the guide post 110 . This extends the movable teeth 145 over the fixed teeth 140 and prevents the protective walls 20 and 25 from accidentally lowering. The protective walls 20 and 25 are lifted until the upper portion of the protective walls fit into a downward facing channel formed by the supports 100 attached to the overhang 95 of the roof. Once at least a portion of the protective walls fit into the downward channel 105 of the supports 100 , the protective walls 20 and 25 enclose the building structure 30 and protect it from high velocity winds. Once the walls are in this position, the pressurized cylinders 55 are locked in place by the ratchet mechanism 15 .
After the winds diminish, in order to allow a lowering of the protective walls 20 and 25 of the embodiment containing guide posts 100 , the movable tooth 145 that is in the locked position is manually pulled back and locked in a recessed position. Illustratively, a release cord 165 (FIG. 5 A), which may be constructed of braided rope or metal mesh, has one end attached to the spring loaded rod and the other to a handle. Alternatively, the spring loaded rod can be dispensed and the release cord 165 directly attached to the movable teeth 145 . In this embodiment, instead of the spring being coiled around the rod, it is coiled around a portion of the release cord 165 which is between the outer surface of the protective wall 20 and 25 and the movable teeth 145 . The spring, whether it is coiled around the braided rope or the rod has a diameter larger than the diameter of the hole that the braided rope and the rod pass through. This keeps the spring between the outer surface of the wall 20 and 25 and the movable teeth 145 . Alternatively, or in addition to the spring, the hinge 135 of the movable teeth 145 may be spring loaded to bias the movable teeth 145 in the forward direction toward the guide post 110 . The movable teeth 145 is recessed back by pulling on the handle. To lock the movable teeth 145 in a recessed position, the handle is hooked on the protrusions attached to the inner surface of the protective walls 20 and 25 .
In an alternative, a safety pin 160 (FIG. 5A) may be inserted in a hole of a fixed plate positioned on the side of the movable teeth 145 . The fixed plate (not shown) is located at the other side of the movable teeth 145 . When the safety pin 160 enters the hole in the fixed plate, the movable teeth 145 is locked in a recessed position. When the movable teeth 145 are locked in this position, the protective walls 20 and 25 can freely slide down the guide posts 110 .
The movable teeth 145 may be pulled back easily when it is located along the segments between two of the fixed teeth 140 . However, pulling back the movable teeth 145 is nearly impossible when it is resting on the fixed teeth 140 , supporting the weight of the protective walls 20 and 25 and preventing it from lowering. Therefore, to be able to pull back the movable teeth 145 while it is supporting the weight of the protective walls 20 and 25 , it is necessary to lift the protective walls 20 and 25 . This removes the weight of the protective walls from the movable teeth 145 so that it may be pulled back to the recessed position. The protective walls may be lifted using the pressurized cylinders 55 . The protective walls 20 and 25 need only be lifted approximately ¼ inch in order to release the engagement of the movable teeth 145 into the fixed teeth 140 and allow the protective walls to lower back into the cavity formed by the reinforced walls.
In the embodiments that are not equipped with guide posts, the protective walls are lowered by simply releasing the fluid from the hydraulic cylinders so that the boom begins to lower. When substantially all the fluid is released from the hydraulic cylinders, the boom is in the resting position. To lift the boom, fluid is again pumped into the hydraulic cylinders.
While the invention has been described by the references to specific embodiments, this was for the purposes of illustration only and should not be construed to limit the spirit or the scope of the invention. Numerous alternative embodiments may be devised by those skilled in the art without departing from the spirit and scope of the following claims.
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An interlocking wall and roof system for the protection of a building structure is disclosed. The interlocking roof and wall system is equipped with a plurality of supports that form downward facing open channels that are either already attached to the overhang of the roof or are easily attachable to the overhang. The system also includes a plurality of protective walls that surround the building structure. The protective walls can be lifted from a resting position to a position where at least a portion of the walls fit into the downward facing open channels of the overhang. These walls are lifted by a hydraulic lifting system. The invention also provides a complete building structure already fitted with the supports, hydraulic lifting system and protective walls.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a power ON reset circuit, and, more particularly to a power ON reset circuit which is suitable for a reset power supply circuit of a microcomputer constituted of CMOS transistors.
2. Description of the Related Art
A microcomputer has many sequential circuits typified by flip-flops. The sequential circuit looses its one stable status once powered off, and will have a so-called unstable status of either a logical value of "0" or "1" when powered on next time. This is called "volatile." A RAM (Random Access Memory) is well known to show this feature most prominently.
For a microcomputer to execute a predetermined operation immediately after power on, the statuses of at least some sequential circuits should always be the same immediately upon power on. In a micro-coded microcomputer, for example, it is necessary to always access the address of the same micro ROM (Read Only Memory) immediately after power on.
To set the status of the sequential circuit, which should always be the same upon power on, immediately after power is given, is called "initialization" or "system reset." This system reset has conventionally been executed using a circuit which outputs a pulse of a given width upon power on. This circuit is called a "power ON reset circuit."
FIG. 1 is a circuit diagram showing an example of a conventional power ON reset circuit. A series circuit of a P channel MOS type FET (Field Effect Transistor) M1 and a resistor R1 is connected between a power supply of voltage VDD and ground, with the FET M1 connected to the power supply (VDD). The gate of the FET M1 is connected to a node N1 between the FET M1 and the resistor R1.
Also connected between the power supply (VDD) and ground is a series circuit of a resistor R2 and an NMOSFET M2, with the FET M2 connected to the ground. The gate of the FET M2 is connected to the node N1, with a capacitor C1 connected between the node N1 and the ground potential.
A series circuit of CMOSFETs M3 and M4 is connected between the power supply (VDD) and ground, with the FET M4 connected to the power supply (VDD). The gates of the FETs M3 and M4 are both connected to a node N2 between the resistor R2 and the FET M2. A capacitor C2 is connected between the supply voltage VDD and the node N2 (the gates of the FETs M3 and M4).
Connected to the subsequent stage of the CMOSFETs M3 and M4 are CMOSFETs M5 and M6 having the same structure as the FETs M3 and M4. The gates of the CMOSFETs M5 and M6 are connected to a node N3 between the FETs M3 and M4. The gates of the FETs M5 and M6 are connected via a capacitor C3 to the ground potential. A node N4 is where the FET M5 is connected to the FET M6.
The input terminals and output terminals of the CMOSFETs M3 and M4 are the node N2 and the node N3 respectively, while the input terminals and output terminals of CMOSFETs M5 and M6 are the node N3 and the node N4, respectively.
This circuit outputs a high pulse which is reset when the power supply voltage VDD rises to a predetermined potential from the ground (GND) potential. This function is accomplished by the capacitors C1 and C3 connected at one end to the GND and the capacitor C2 connected to the power supply of voltage VDD. When the power is given from the power supply (VDD), those capacitors C1, C3 and C2 are not charged so that the nodes N1, N2 and N3 are at the same potential levels as the power supply voltage VDD and GND. But, the output of the node N4 becomes a high level (potential nearly equal to the supply voltage VDD) first, after which the capacitors C1-C3 are charged in order and the potentials at the nodes N1, N2 and N3 become the potentials of the (VDD-|VTM1|), GND and VDD. As a result, the output of the node N4 becomes a low level (about the GND potential). VTM1 is the threshold voltage of the FET M1.
As the output of the node N4 becomes a low level, VDD-|VTM1| should be higher than the logical threshold voltage of an inverter comprising the FET M2 and the resistor R2.
It is apparent from the above that the circuit which merely outputs a reset pulse upon power on can be accomplished by a simple structure having PMOSFETs M7 and M9, an NMOSFET M8 and a capacitor C4 as shown in FIG. 2. In FIG. 2, the FET M7 and the capacitor C4 are connected in series between the power supply of voltage VDD and ground, while the PMOSFET M9 and NMOSFET M8 are connected in series therebetween. The gates of the FETs M9 and M8 are both connected to a node N5 where the FET M7 is connected to the capacitor C4, with the gate of the FET M7 grounded. A node N6 where the FET M9 is connected to the FET M8 is the output terminal of this circuit.
Referring to FIG. 2, as the capacitor C4 has not been charged immediately after power from the supply voltage VDD is given, the node N5 becomes a low level and the output of the node N6 becomes a high level. If the potential of the power supply voltage VDD is higher than the absolute value of the threshold voltage of the FET M7 thereafter, the FET M7 is turned on, causing the capacitor C4 to be charged up. As a result, the nodes N5 and N6 respectively become a high level and a low level.
The power ON reset circuit shown in FIG. 1 has an advantage over the circuit shown in FIG. 2 in that the former circuit also has the function of a voltage detector. Even if the VDD potential falls after the supply voltage VDD rises once and the output of the node N5 becomes a low level in the circuit in FIG. 2, the node N6 stays low and there is no way to know that the VDD potential has dropped.
According to the circuit in FIG. 1, from a viewpoint of DC current, when the potential of the power supply voltage VDD becomes higher than |VTM1|+VTM2 (VTM2: threshold voltage of the FET M2), the output of the node N4 becomes a low level while when the VDD potential becomes lower than |VTM1|+VTM2, the output of the node N4 becomes a high level, thus making it possible to detect whether the power supply voltage VDD is higher or lower than |VTM1|+VTM2. This is because that as the gate and drain of the FET M1 are short-circuited, the potential at the node N1 becomes VDD-|VTM1| and the potential at the node N2 changes from a high level to a low level when VDD-|VTM2| becomes higher than the logical threshold voltage of the inverter which comprises the FET M2 and the resistor R2. That is, the potential at the node N4 is a low level when the value of A expressed by the following relationship is positive: A=VDD-|VTM1|-(the logical threshold value of the inverter having the FET M2 and resistor R2). Conversely, the potential at the note N4 is a high level when the value of A is negative.
As the load of the inverter comprising the FET M2 and the resistor R2 has a constant resistance R2, the logical threshold value of this inverter is around the threshold voltage of the FET M2 whose current varies greatly. Accordingly, when VDD-|VTM1|-VTM2=VDD-(|VTM1|+VTM2) is positive, the output of the node N4 in the power ON reset circuit in FIG. 1 becomes a low level, while the former potential is negative, the output of the node N4 becomes a high level, so that the positive or negative difference between VDD and |VTM1|+VTM2 will be detected. It is of course possible to adjust the detection voltage by the resistances of the resistors R1 and R2 and (gate width)/(gate length) of the FETs M1 and M2.
In general, a power ON reset circuit which, like the one shown in FIG. 1, can also detect the DC supply voltage is incorporated in the microcomputer that is used in battery-driven devices, such as portable devices. This power ON reset circuit allows the microcomputer to inform a user of a low battery or stops the microcomputer before it crashes due to the battery voltage dropping below the proper operational voltage range.
Due to the recent widening application of microcomputers to various types of portable devices, fast operation of microcomputers is often demanded in battery-driven devices. The operational voltage range therefore becomes narrower, demanding for a power ON reset circuit which can detect the supply voltage more accurately.
Since the detection voltage of the conventional power ON reset circuit in FIG. 1 depends on (VTM1+VTM2), this circuit has a large manufacturing variation and is temperature dependent. As the threshold voltage of MOSFETs normally has a manufacturing variation of ±0.1 to ±0.2 V and a temperature dependency of around -2 mV/° C., (VTM1+VTM2) has a temperature variation of ±0.2 to ±0.4 V normally, and about ±0.2 V with the operational temperature range set to ±50° C. The difference between the maximum and minimum values of the detection voltage therefore becomes 0.8 to 1.2 V.
A band-gap reference voltage generator is well known as having a high voltage precision. FIGS. 3 and 4 illustrate two typical examples of the conventional band-gap reference voltage generator which uses MOSFETs. The anode area is determined so that the saturated currents IS1, IS2 and IS3 of PN junction diodes D1, D2 and D3 have a relation of IS1=IS3>IS2. The ratio of the resistance of a resistor R3 to that of a resistor R4 is set to a predetermined value according to the output voltage. For easier explanation, it is assumed below that ratio R4/R3=n (n: positive integer).
In the circuit in FIG. 3, a diode D1, a resistor R3 and CMOSFETs M10 and M11 are connected in series, a diode D2, and CMOSFETs M12 and M13 are connected in series, with the gates of the FETs M11 and M13 connected together and the gates of the FETs M10 and M12 connected together, and a diode D3, a resistor R4 and PMOSFET M14 are connected in series, with the gate of the FET M14 connected to the gates of the FETs M11 and M13. The VDD side end of the resistor R3 is a node N10, the anode of the diode D2 is a node N11, and the VDD side end of the resistor R4 is a node N12 which is the output terminal of this circuit.
The circuit in FIG. 4 has a comparator 7 which has the node N10 as a positive (+) input 8 and the node N11 as a negative (-) input 9 and has its output coupled to the gate of the FET M14. This circuit does not have the FETs M10 and M12 of the circuit shown in FIG. 3. Except for those points, the circuit in FIG. 4 is the same as the circuit in FIG. 3. Therefore, the same reference numerals as used in FIG. 3 are also used in FIG. 4 to denote the identical or corresponding components, and their detailed explanation will not be repeated.
The PMOSFETs M11, M13 and M14 have the same ratio of (gate width)/(gate length) and NMOSFETs M10 and M12 also have the same (gate width)/(gate length).
The operations of those circuits will now be discussed. In FIGS. 3 and 4, the constant current flows through the FETs M11, M13 and M14, and the current value is determined so that the potentials at the nodes N10 and N11 become equal to each other. When the same current flows through the FETs M10 and M12, their gate-source voltages should be the same, because the FETs M10 and M12 have the same (gate width)/(gate length) ratio. With the gates of the FETs M10 and M12 short-circuited, therefore, the potentials at the nodes N10 and N11 where the sources of those transistors are connected become equal to each other. In FIG. 4, the potentials at the nodes N10 and N11 are compared with the comparator 7 and are so controlled as to be equal to each other. Thus, the following equation is derived.
I×R3+VT×ln(I/IS1)=VT×ln(I/IS2)
where I is the current flowing through the FETs M11, M13 and M14 and VT=kT/q (k: Boltzmann's constant, T: absolute temperature and q: unit charge). Thus, I is given by the following equation (1).
I=VT×ln(IS1/I2)×1/R3 (1)
The output voltages of the nodes N12 and N13 both become the voltage across the resistor R4, which is given by the following equation (2), plus the forward voltage across the diode D3.
R4×VT×ln(IS1/IS2)×1/R3=n×VT×ln(IS1/IS2)(2)
The equation (2) is determined by the resistance ratio n, the ratio of the anode area of the diode D1 to that of the diode D2, and the absolute temperature T. Generally speaking, the area ratio of the resistors, the PN junction, and etc. is obtained at high precision by the MOS processing technology, so that the output voltage given by the equation (2) becomes a constant value very accurately at a constant temperature.
As the absolute value of the forward voltage of diodes normally has a slight variation of less than about ±20 mV at a constant temperature, the output voltages at the nodes N12 and N13 are approximately constant at the same temperature and are about 1.1 to 1.2 V at the normal temperature.
While the voltage across the resistor R4 has a positive temperature dependency with respect to the absolute temperature T as apparent from the equation (2), the forward voltage of diodes has a negative temperature dependency. The temperature characteristic can therefore become considerably small by properly selecting n in the equation (2).
FIG. 5 shows a circuit which uses a circuit 14 similar to the one shown in FIG. 3 or FIG. 4, in addition to a comparator 16 and resistors R5 and R6. This circuit can accurately detect the power supply voltage of an arbitrary value by selecting the proper resistances for the resistors R5 and R6. Thus, the circuit in FIG. 5 is expected to be adapted for a power ON reset circuit. The circuit in FIG. 5 however has two critical shortcomings as a power ON reset circuit.
First, the circuits shown in FIGS. 3 and 4 do not properly function by simply activating the power supply (VDD) because the state of no current flowing through the FETs M11 and M13 before power on will be satisfied in those circuits even after the power supply (VDD) is activated. The requirements for the circuits in FIGS. 3 and 4 are such that the same current should flow through both the FETs M11, M13 and M14, and also through the FETs M10 and M12, and that the potentials at the nodes N10 and N11 should be equal to each other. The state of no current flowing through the FETs M11 and M13 fulfills the requirements.
As a solution to this problem, a capacitor C5 is connected to a node N14 in the circuit in FIG. 3, and a capacitor C6 is connected to a node N15 in the circuit in FIG. 4, as shown in FIGS. 6 and 7, respectively. With this modification, upon power on, the PMOSFETs M11 and M13 are always turned on to permit a current to flow therethrough, and the modified circuits will properly start functioning. This modification, however, has the following shortcoming. Given that VGSM11 represents the potential difference between the gate and source of each of the FETs M11 and M13 under the proper operation, when VDD drops abruptly by |VGSM11|-max(|VTM1|, |VTM3|), the FETs M11 and M13 are turned off and the current flowing through those FETs M11 and M13 becomes 0 (max (a, b) representing a larger one of a and b). Even if the supply voltage VDD is above the designed detection voltage, the modified circuits still have the same power-on problem as the circuit without the capacitor C5 or C6 has.
The second critical shortcoming is that the modified circuits would malfunction when the supply voltage falls down to or below a certain level. To provide the expected output voltage, all the MOSFETs in the circuit in FIG. 3, the FETs M10 to M14, should operate in the saturated area. In view of the series connection of the diode D2 and FETs M12 and M13, this requires a supply voltage equal to or above
0.1 V+VTM12+VFD2 (3)
where VTM12 is the threshold voltage of the FET M12 which is normally about 0.7 V, VFD2 is the forward voltage of the diode D2, normally about 0.5 to 0.7 V, and the first term, 0.1 V, is the minimum voltage necessary to saturate the FET M13.
The voltage expressed by the equation (3) is therefore normally 0.3 to 1.5 V below which the output of the node N12 rapidly drops, setting a low level in the circuit in FIG. 3 as in the case where the supply voltage is sufficiently high. When the supply voltage becomes below the operational voltage of the comparator 7, the circuit in FIG. 4 naturally malfunctions. Normally, the minimum operational voltage of a comparator designed by the CMOS processing technology to function on a low voltage is about 1.5 to 1.8 V. The power ON reset circuit shown in FIG. 1 does not have the above-described two problems inherent to the circuit in FIG. 5 which is designed based on the circuit in FIG. 3 or FIG. 4. In this respect, the power ON reset circuit in FIG. 1 having a large variation in detection voltage has conventionally been used in a microcomputer.
While the conventional power ON reset circuit in FIG. 1 surely outputs a reset pulse upon power on, it has a large variation in DC detection voltage, so that the voltage allowable by the entire microcomputer-based system should be the minimum operational voltage of microcomputers plus a voltage variation of the power ON reset circuit. In other words, while this conventional circuit can control the crashing of microcomputers, it inevitably requires an increased minimum operational voltage.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a power ON reset circuit which will detect a supply voltage at a high precision and allows the minimum operational voltage of a microcomputer to be designed lower.
A power ON reset circuit according to one aspect of the present invention has a voltage detector, which has a low minimum operational voltage and surely outputs a pulse upon power on though having a large variation in detection voltage, in combination with a band-gap reference voltage generator, which uses the output pulse of the detector to have an improved power-on operation and has an additional capacitor to properly function even if there is a sharp change in supply voltage. This power ON reset circuit can therefore accomplish a power ON reset function as well as a function of detecting the supply voltage at a high accuracy.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a circuit diagram showing one example of a conventional power ON reset circuit;
FIG. 2 is a circuit diagram showing another example of the conventional power ON reset circuit;
FIG. 3 is a circuit diagram showing one example of a conventional band-gap reference voltage generator;
FIG. 4 is a circuit diagram showing another example of the conventional band-gap reference voltage generator;
FIG. 5 is a circuit diagram showing an example of the application of the circuit in FIG. 3 or FIG. 4;
FIG. 6 is a circuit diagram of an improved modification of the circuit in FIG. 3;
FIG. 7 is a circuit diagram of an improved modification of the circuit in FIG. 4;
FIG. 8 is a block diagram showing a power ON reset circuit according to a first embodiment of the present invention;
FIG. 9 is a circuit diagram of a first example of a voltage generator shown in FIG. 8;
FIG. 10 is a circuit diagram of a second example of the voltage generator shown in FIG. 8;
FIG. 11 is a waveform diagram showing a first example of the operation of the circuit in FIG. 8;
FIG. 12 is a waveform diagram showing a second example of the operation of the circuit in FIG. 8;
FIGS. 13A and 13B are timing charts for explaining the operation of the first embodiment;
FIG. 14 is a circuit diagram showing a second embodiment of the present invention; and
FIGS. 15A and 15B are timing charts for explaining the operation of the second embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 8 presents a block diagram showing a power ON reset circuit according to a first embodiment of the present invention. Referring to FIG. 8, the power ON reset circuit of this embodiment comprises a supply-voltage detector 17, which has an excellent characteristic at the time of power on at which a variation in detection voltage is normally large and has a wide operational voltage, i.e., the above-described circuit in FIG. 1, and a band-gap reference voltage generator 18 with an improved supply-voltage variation characteristic, i.e., the circuit in FIG. 9 or the circuit in FIG. 10. This power ON reset circuit further comprises an exclusive OR (EXOR) gate 20, which has one input connected directly to an output node N4 of the detector 17 and another input connected via a delay circuit 19 to this node N4 and has its output connected to an input node N23 of the voltage generator 18, a comparator 16, which receives the voltage of a power supply VDD divided by resistors R5 and R6 as a negative (-) input and the output from a node N12 of the voltage generator 18 as a positive (+) input, and an OR gate 21, which receives the output (node N25) of the comparator 16 and the output node N4 of the detector 17 as its inputs and provides an output from a node N22.
FIG. 9 illustrates a first specific example of the circuit structure of the voltage generator 18 shown in FIG. 8. This generator 18 has an NMOSFET M15, which has the input from the node N23 as a gate input, and a capacitor C6 connected between the gates of the FETs M11 and M13 and the power supply VDD. Since this circuit is the same as the one shown in FIG. 6 except for the NMOSFET M15 and capacitor C6, the same reference numerals as used in FIG. 6 will also be used in FIG. 9 to denote the corresponding or identical components and their description will not be repeated below.
FIG. 10 illustrates a second specific example of the circuit structure of the voltage generator 18 shown in FIG. 8. This generator 18 has an NMOSFET M15, which is connected between the output of the comparator 7 and the ground potential and has the input node N23 as its gate input, and a capacitor C6 connected between the output of the comparator 7 and the power supply VDD. Since this circuit is the same as the one shown in FIG. 7 except for those FET M15 and capacitor C6, the same reference numerals as used in FIG. 7 will also be used in FIG. 10 to denote the corresponding or identical components and their description will not be repeated below.
As mentioned above, the power ON reset circuit according to this embodiment has the voltage detector 17, which surely outputs a pulse upon power on, the pulse generating circuit which produces a pulse with a predetermined width when the potential status of the output node N4 changes from a low level to a high level or vice versa, and the voltage generator 18, which has the output of the pulse generating circuit as its one input and has a small manufacturing variation and a small temperature dependency. While having a large manufacturing variation and large temperature dependency, the voltage detector 17 can detect the DC supply voltage and will not malfunction even when the supply voltage is around 0 V. Further, the detection voltage of the voltage detector 17 is always higher than the minimum operational voltage of the voltage generator 18.
The voltage detector 17 is the power ON reset circuit shown in FIG. 1, which is used in a microcomputer, and thus has the following three major characteristics as mentioned earlier.
(1) It always outputs a reset pulse upon power on.
(2) It operates even on a voltage of around 0 V.
(3) It functions as a DC supply-voltage detector whose detection voltage has a large manufacturing variation and large temperature dependency.
The voltage generator 18 is an improved band-gap voltage generator of this invention, whose specific structure is illustrated in FIG. 9 or FIG. 10 and which has the following four major characteristics.
(1) It will not operate upon power on.
(2) It malfunctions when the supply voltage becomes lower than about 1.3 to 1.8 V.
(3) When the supply voltage drastically changes, the circuit keeps malfunctioning thereafter.
(4) The voltage detecting accuracy under the normal operation has a small manufacturing variation and shows a small temperature dependency.
The combination of the circuit 17 and the circuit 18 as in this embodiment will overcome the aforementioned shortcoming (3) of the circuit 17 and the aforementioned shortcomings (1), (2) and (3) of the circuit 18, and will only have the merits (1) and (2) of the circuit 17 and the merit (4) of the circuit 18.
The reason for the above will now be discussed.
When the supply voltage VDD is given, the circuit 17 which is used as a power ON reset circuit for a microcomputer outputs a high-pulse voltage E whose peak voltage is nearly equal to the detection voltage (broken line) of the circuit 17 as shown in FIG. 11 when the supply voltage VDD rises slowly and outputs a high-pulse voltage E whose peak voltage is equal to the supply voltage VDD after rising as shown in FIG. 12 when the supply voltage VDD rises sharply.
When the potential at the node N4 of the circuit 17 changes to a low level from a high level at this time, the EXOR 20, whose inputs are the output from the node N4 and the output of the delay circuit 19 connected to the node N4, outputs a high pulse having a width equivalent to the amount of delay of the delay circuit 19 at the falling edge. This pulse becomes the input (node N23) of the band-gap reference voltage generator 18 and is input to the gate of the NMOSFET M15 in FIG. 9 or FIG. 10.
Upon power on, therefore, the gates of the PMOSFETs M11, M13 and M14 of the voltage generator 18 are temporarily short-circuited, so that a current flow through the series circuit including the FETs M11 and M13 at the initial stage, allowing the power ON reset circuit to start functioning properly. The drawback (1) of the circuits shown in FIGS. 1 and 2 is therefore overcome.
While the output of the EXOR gate 20 is at a high level, a through current flows through the FETs M11 and M15, but this current is a pulse current which hardly increases the average current consumption.
Further, even though the NMOSFET M15 is added, the circuits shown in FIGS. 9 and 10 do not have a lower detection precision than the conventional band-gap reference voltage generators shown in FIGS. 3 and 4.
After the circuit 18 starts the normal function and the output of the node N12 becomes stable, the comparator 16 compares the voltage obtained by dividing the supply voltage VDD by the resistors R5 and R6, with the output voltage of the circuit 18 at the node N12. The output of the comparator 16 becomes a low level when the supply voltage VDD is higher than the voltage expressed by the following equation (4) and becomes a high level when VDD is lower than that voltage, thus accomplishing the function to detect whether the supply voltage VDD is higher or lower than the voltage given by the equation (4).
(R5+R6)×(output voltage of circuit 18)×1/R6 (4)
Since the voltage having a small manufacturing variation and a small temperature dependency is multiplied by the resistance ratio in the equation (4), the voltage given by this equation also has a small manufacturing variation and a small temperature dependency, so that the precision of detecting the supply voltage VDD is considerably high.
The outputs of the circuit 17 and the comparator 16 are input to the OR gate 21. When one of the inputs has a high level, the output (node N22) of the power ON reset circuit of this embodiment becomes a high level, invoking the system reset. When one of the inputs has a low level, on the other hand, the microcomputer is permitted to function.
The reason why the output at the node N22 is given by the OR operation of the outputs of the circuit 17 and comparator 16 is that when the supply voltage falls below the minimum operational voltage of the circuit 18, the lower limit of the detection voltage of the circuit 17 is set to slightly higher than this minimum operational voltage of the circuit 18 to thereby overcome the shortcoming (2) of the conventional band-gap reference voltage generator.
In addition, since the capacitor C6 is connected between the gates of the FETs M11 and M13 and the power supply VDD in FIGS. 9 and 10, which show specific circuits examples of this embodiment, the gate-source voltages of the FETs M11 and M13 are kept constant even if there is a sharp variation in supply voltage. Accordingly, the shortcoming (3) of the conventional circuits in FIGS. 3 and 4 is overcome. In short, even when the supply voltage is about 1.3 to 1.5 V upon power on or when the supply voltage VDD suddenly changes, the power ON reset circuit of this embodiment always has a detection precision that is achieved by the precision of the output voltage of the band-gap reference voltage generator 18 multiplied by a resistance ratio.
FIGS. 13A and 13B are timing charts for the individual signals of the power ON reset circuit shown in FIG. 8. Those diagrams show the voltage at a node N24 at which the supply voltage VDD is divided by the resistors R5 and R6 and the voltage at the output node N25 of the comparator 16 in addition to the supply voltage VDD and the voltages at the nodes N12, N22 and N23. FIG. 13A shows the case where the supply voltage VDD rises or falls slowly, and FIG. 13B shows the case where the supply voltage VDD rises sharply. The supply voltage VDD will not fall suddenly.
Referring to FIG. 14, a power ON reset circuit according to a second embodiment of the present invention will be described. This embodiment differs from the first embodiment only in that the output of the voltage detector 17 (node N4) is supplied to one input of the OR gate 21 through the delay circuit 19 and another delay circuit 24 at the subsequent stage. Since the other parts are the same as those of the circuit shown in FIG. 8, the same reference numerals as used in FIG. 8 will also be used in FIG. 14 to denote the corresponding or identical components and their description will not be repeated below.
In the second embodiment, the output (node N4) of the circuit 17 is connected to one input of the OR gate 21 via two stages of delay circuits 19 and 24, not directly, thereby providing a large delay from the output (node N4) of the detector 17 to the input (node N26) of the OR gate 21. Before the circuit 18 starts functioning, therefore, the input (node N26) of the gate 21 connected to the circuit 17 becomes a low level, thus preventing the reset state from being canceled.
FIGS. 15A and 15B are timing charts for the individual signals of the power ON reset circuit according to the second embodiment. Those diagrams show the voltage at a node N26 of the delay circuit 24 in addition to those signals shown in FIGS. 13A and 13B. FIG. 15A shows the case where the supply voltage VDD rises or falls slowly, and FIG. 15B shows the case where the supply voltage VDD rises sharply. Likewise, the supply voltage VDD will not fall suddenly. During a period T in FIG. 13A, the voltage at the node N4 and the voltage at the output node N25 of the comparator 16 are both at a low level, so that the circuit may malfunction during this period T. In FIG. 15A, the voltage at the node N4 and the voltage at the output node N25 of the comparator 16 will not become a low level at the same time, so that the circuit will not malfunction during that period.
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A supply-voltage detector having a low minimum operational voltage while having a large variation is combined with a supply-voltage detector having a high detection precision while having a high minimum operational voltage, so that the supply voltage is detected at a high accuracy without malfunctioning even on a low voltage. A system, such as a microcomputer, could then be reset when the detected supply voltage falls below a certain value. This combined circuit will improve the accuracy of detecting this supply voltage.
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BACKGROUND
[0001] The present invention relates to a coupon issuing method and a coupon issuing system, and in particular to a method and system for generating and issuing a coupon on the basis of an image generated by a user.
[0002] In recent years, various kinds of coupons are being used at a restaurant, a movie theater, an online shopping mall, etc., which allow a customer to buy products and services at lower prices. A coffee shop, a book store, a restaurant, a beauty shop, a beauty parlor, a private educational institute, a travel/accommodation facility, a recreation/movie theater, etc. which provides various kinds of product and services may promote the sales of such products and services, thus increasing sales.
[0003] Since the above-mentioned coupons may be distributed only through a distribution enterprise established for the distribution of such coupons, the above-listed shops cannot have any chances to provide the coupons to a number of unspecified customers.
[0004] To this end, the Korean patent application number 2010-0096344 describes a method for providing a discount coupon sale agent service using a social commerce, wherein for a sale agent of a discount coupon with respect to an item or a sale service requested from an advertiser, a social commerce server provides a discount coupon on an internet webpage. As a condition for finally determining the purchase of the discount coupon, a minimum sale quantity and sale period are given together. A user pays a purchase money corresponding to the price discounted with a discount coupon and inputs a recommender of the discount coupon. The social commerce server provides a reward for the recommendation provided by a multi-level marketing method with respect to the recommender and an upper level recommender. The system is designed to increase the reward on the basis of a number of recommendations calculated in the multi-level marketing method with respect to each recommender. In addition, a predetermined upper limit is set with respect to the above reward. The above-described prior art document discloses just a coupon sale method, not resolving the problem wherein the coupons should be distributed through only a limited distribution enterprise. To this end, it needs to develop a technology which is able to resolve the above mentioned problem.
[0005] In recent years, a SNS (Social Network Service) becomes a hot issue. The users can post an image, a video, etc. taken by himself on a SNS page. In particular, if a specific product or service is purchased or used, the user posts an image or video showing the product or service that the user purchased or used before. There may be a potential way to resolve the above-mentioned problems using the above new trend.
[0006] The inventor of the present invention owns the above-described background technology for the development of the present invention or as a technical information obtained during the development of the present invention, so such a background technology may not mean a prior art technology open to the public.
SUMMARY OF THE INVENTION
[0007] Accordingly, It is an object of the present invention to provide a coupon issuing method and a coupon issuing system.
[0008] To achieve the above object, according a first aspect of the present invention, there is provided a coupon issuing method which may be executed by a coupon issuing system wherein an interaction with a first user is available, which may include, but is not limited to, obtaining an image information and shop identification information generated by the first user; generating a coupon on the basis of the image information and shop identification information; and issuing the generated coupon.
[0009] To achieve the above object, according a second aspect of the present invention, there is provided a coupon issuing system wherein an interaction with a first user is available, which may include, but is not limited to, an information obtaining unit configured to obtain an image information and shop identification information generated by the first user; a coupon generating unit configured to generate a coupon on the basis of the image information and shop identification information; and a coupon issuing unit for issuing the generated coupon.
[0010] On the basis of any one of the above-mentioned objects of the present invention, an exemplary embodiment of the present invention can provide a coupon issuing method and to coupon issuing system.
[0011] On the basis of any one of the above-mentioned objects of the present invention, the present invention can provide a coupon issuing method and to coupon issuing system which allow to introduce a self-advertisement of a user at a coffee shop, a restaurant, a movie theater, etc., thus naturally advertising shops.
[0012] According to any one of the objects of the present invention, a user can share an advertisement containing a shop benefit with his colleagues on the SNS service, which may promote the sale in the shop, while providing the colleagues with a reliable advertisement.
[0013] The effects which may obtained in the present invention are not limited to the above-described effects. Other effects not mentioned in the above may be understood clear by a person having ordinary skill in the art with the aid of the descriptions below.
BRIEF DESCRIPTION OF DRAWINGS
[0014] FIG. 1 is a view illustrating a configuration of a coupon issuing system according to an exemplary embodiment of the present invention.
[0015] FIG. 2 is a block diagram illustrating a coupon issuing system according to an exemplary embodiment of the present invention.
[0016] FIG. 3 is a flow chart for describing a coupon issuing method according to an exemplary embodiment of the present invention.
[0017] FIGS. 4 to 7 are views for describing a coupon issuing method according to an exemplary embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0018] The preferred exemplary embodiments of the present invention will be described with reference to the accompanying drawings so that a person having ordinary skill in the art can implement the present invention. The present invention may be implement in various forms, which is not limited thereto. For the sake of better understanding, the portions not directly related to the description of the present invention will be omitted, and similar components throughout the specification are given same reference numbers.
[0019] In the descriptions of the present invention, the term “connected” with other portions means a “direct connection” and a “electrical connection” with a predetermined component being connected between the two connected components. The term “include”, unless otherwise stated, may mean “including another component”, not excluding other components.
[0020] The present invention will be described with reference to the accompanying drawings.
[0021] FIG. 1 is a view illustrating a configuration for describing a coupon issuing system 100 according to an exemplary embodiment of the present invention.
[0022] The coupon issuing system 100 is a system which is able to interact with a user and may include, but is not limited to, a user terminal 10 , and a coupon issuing server 20 .
[0023] The user terminal 10 and the coupon issuing server 20 may communicate each other through a network “N”. The network “N” may be any of all kinds of wired/wireless networks, for example, a local area network (LAN), a wide area network (WAN), a value added network (VAN), a personal area network (PAN), a mobile communication network, a Wibro (Wireless broadband internet), a mobile WiMAX, a HSDPA (High Sped Downlink Packet Access), and a satellite communication network.
[0024] For this, the user terminal 10 is configured to process an interaction with a user who wants to generate a coupon through a coupon issuing system or wants to receive a coupon.
[0025] For example, the user terminal 10 may have a client program to execute a coupon issuing method. The coupon issuing service provided by the coupon issuing system can be provided to a user who may control the user terminal 10 .
[0026] At this time, depending on the roles of the user, the user terminal 10 may be classified into a first terminal 110 , a second terminal 120 and a third terminal 130 .
[0027] The first terminal 110 may obtain an image information and a shop identification information to generate a coupon and may be controlled by a first user who wants to generate a coupon.
[0028] The second terminal 120 may receive the generated coupon and may be controlled by a second user who wants to take any benefit coming together with the coupon after the coupon is obtained.
[0029] The third terminal 130 may obtain an information to generate a shop identification information and may be preferably controlled by a third user who provides an item (including product or service) which is sold on a shop like an owner or a staff of a shop. Here, the shop means all kinds of shops, for example, an online shop, an offline shop, etc.
[0030] Meanwhile, an acquaintance relationship may be set between the first user and the second user in the coupon issuing system 100 (or third party server (not shown)). If the coupon that a user, one party, has generated or obtained can be received by another user, the other party, both the users may be called “acquaintance”. The second user who has an acquaintance relationship with the first user can receive the coupon generated by the first user.
[0031] According to an exemplary embodiment of the present invention, the first terminal 110 , the second terminal 120 and the third terminal 130 may perform the above-described work, but the roles of each terminal may be changed with one another. The roles of the first terminal 110 , the second terminal 120 and the third terminal 130 may be changed, thus performing all the above work.
[0032] The user terminal 10 may include a photographing device (for example, a camera) to photograph an image (a still image, a motion image (video), etc.) or an identification information (one to three dimensional codes, etc.), which can be photographed. In addition, the user terminal 10 may include a reading device (RFID reader, NFC reader, etc.) which is able to read various kinds of information (for example, RFID (Radio Frequency Identification) tag, NFC (Near Field Communication) tag, etc.) which could be the target of the reading.
[0033] The user terminal 10 may be a computer, a portable terminal or a television which may access through a network “N” to a distant coupon issuing server 20 or a third party server or may be connected with other user terminals and a server. Here, the computer may be a notebook computer, a desktop computer, a laptop computer, etc. which equips with a WEB browser, and the portable terminal is a wireless communication device which has a portability and mobility and may be all kinds of handheld-based wireless communication devices, for example, PCS (Personal Communication System), PDC (Personal Digital Cellular), PHS (Personal Handyphone System), PDA (Personal Digital Assistant), GSM (Global System for Mobile Communication), IMT (International Mobile Telecommunication)-2000, CDMA (Code Division Multiple Access)-2000, W-CDMA (W-Code Division Multiple Access), Wibro (Wireless Broadband Internet), a smart phone, a mobile WiMAX (Mobile Worldwide Inter operability for Microwave Access), a wearable device, etc. The television may be IPTV (Internet Protocol Television), an internet TV, a ground wave radio TV, a cable TV, etc.
[0034] The coupon issuing server 20 may generate or issue a coupon based on a coupon issuing method while communicating with the user terminal 10 .
[0035] For example, the coupon issuing server 20 may operate like a server with respect to the user terminal 10 having a client program.
[0036] The coupon issuing server 20 may receive from the user terminal 10 an image information, a shop identification information, etc. to generate coupons and may generate coupons and provide to the coupons to the user terminal 10 .
[0037] Meanwhile, the coupon issuing system 100 may communicate with a third party server (not illustrated) through a network “N”.
[0038] The third party server may post the coupon received from the coupon issuing system 100 and may post the generated coupon on the user account of the third party server of the first user. The third party server may provide a SNS (Social Network Service), whereupon the second user who has an acquaintance relationship with the first user who has posted the coupon on the user account of the third party server may receive the coupon through the account of the first user.
[0039] Meanwhile, the coupon issuing server 20 and the third party server (not illustrated) may be implemented with a conventional web server to which a web access is available or a conventional mobile web server to which a mobile web access is available. The coupon issuing server 20 and the third party server (not illustrated) may be a web server which is able to provide a web service to the user terminal 10 . For example, they may be a portal site server or a server system of each various wed contents providers, for example, an online shopping server, etc. The coupon issuing server 20 and the third party server (not illustrated) may be implemented with a group of server systems, for example, a load balancing server, a database server, etc.
[0040] FIG. 2 is a block diagram illustrating a coupon issuing system 100 according to an exemplary embodiment of the present invention.
[0041] Referring to FIG. 2 , the coupon issuing system 100 may include, but is not limited to, an information obtaining unit 210 , a coupon generating unit 220 , a coupon issuing unit 230 and an account managing unit 240 .
[0042] The coupon issuing system 100 may include a communication unit (not illustrated) which allows a communication with internal components, for example, the information obtaining unit 210 , the coupon generating unit 220 , the coupon issuing unit 230 and the account managing unit 240 and also allows a communication with external components.
[0043] The coupon issuing system 100 may include a storing unit (not illustrated) to store data for executing the coupon issuing method according to an exemplary embodiment of the present invention and may communicate with an externally located storage (not illustrated), for example, a database.
[0044] The information obtaining unit 210 may obtain information to generate coupons.
[0045] The information obtaining unit 21 may obtain an image information and a shop identification information.
[0046] Here, the image information may include general information on the image generated by the user. For example, the image information may be any of an image, an image identification information, an image detail description, an image generation time and a position information on the position where the image is generated.
[0047] The shop identification information means an information to identify the shop from other shops or users. The shop identification information may be formed of a series of characters or numbers or may be implemented with a one-dimensional barcode, a two-dimensional barcode or a three-dimensional barcode or may be implemented with a RFID tag or a NFC tag. Such a shop identification information may be same as the user identification information of the third user and may be included in the user identification information of the third user or may include a user identification information of the third user.
[0048] The information obtaining unit 210 may obtain a shop identification information and may provide a photographing interface to generate an image information on the basis of the obtaining of the shop identification information and may obtain an image information through the photographing interface.
[0049] The information obtaining unit 210 may obtain an image information and may provide an input interface to receive the shop identification information and may obtain a shop identification information through the input interface.
[0050] The coupon generating unit 220 may generate a coupon based on the image information and the shop identification information.
[0051] The coupon generating unit 220 may obtain a shop information corresponding to the shop identification information and including any of a shop name information, a shop position information and a shop contact information, thus generating a coupon by adding the shop information to a coupon information.
[0052] At this time, if the matching shop information is stored in the shop identification information, the shop information may be obtained by searching for a shop information matching with the obtained shop identification information. For example, the shop information may be registered in the coupon issuing system 100 by other users or a shop owner. To this end, the coupon generating unit 220 may obtain the registered shop information by searching force the shop identification information matching with the shop information.
[0053] The coupon generating unit 220 may obtain a shop information in such a way to extract a shop information contained in the shop identification information. For example, if a shop information is contained in the obtained shop identification information itself, namely, if the shop identification information is an image, the coupon generating unit 220 may extract and obtain a shop information from the shop identification information itself based on a technique, for example, an OCR (Optical Character Reader).
[0054] The coupon generating unit 220 may generate a coupon by adding any of the user identification information of the first user who provides an image and the shop information to a coupon information. Here, the coupon information means various information that the user can confirm for reading the coupon information or a general information which is necessary for the user to use. Here, the coupon information may include any of a benefit information which can be received when using the coupon, a shop information to use coupons, an image information of the image used for the coupon, a user identification information of a user who generates a coupon, and a coupon identification information to identify the coupon.
[0055] In addition, the coupon generating unit 220 may generate a user identification information of the user which will be added to a coupon information and may add to the coupon. In addition, it may generate an identification information by combining the user identification information and the shop information (or shop identification information) and may add to a coupon. For example, the coupon generating unit 220 may generate a new identification information by combining the user identification information of the first user and the shop identification information (or the user identification information of a third user) and may add the generated identification information to the coupon information. The thusly added identification information allows an access to the account of the first user who has generated the coupon when confirming the coupon and an access to the account of the third user who will use the coupon.
[0056] The coupon generating unit 220 determines the matching of the image information and the shop identification information based on the position information included in the image information obtained for the generation of the coupon, thus generating a coupon in case of matching.
[0057] The coupon issuing unit 230 may issue the generated coupon to other users.
[0058] At this time, the coupon issuing unit 230 may issue the coupon for a predetermined time period and may continuously issue the coupon. The coupon issuing unit 230 is basically configured to issue coupons, but may issue by limiting a range (for example, a use who has generated the coupon and an acquaintance user) of targets who may receive the coupon, and the number of the targets may be limited when issuing. The coupon issuing unit 230 may provide the coupons to the second user by selecting the coupons based on the characteristic of the second user who reads the coupons (for example, the position of the second user (the position registered by the second user or the position of the second user when reading the coupon), the age of the second user, the category of the read coupon, etc.).
[0059] The coupon issuing unit 230 may issue through a service which is provided through the third party serer in such a way to transfer the coupon (or coupon information) to the third party server. Such a third party server has an allocated third party identification information to identify the third party server, so the coupon issuing unit 230 may add the third party identification information to the coupon information when transferring the coupon to the third party server.
[0060] The coupon issuing unit 230 may provide a reading interface which allows the second user who wants to receive a coupon to receive the coupon. The reading interface may allow the coupon to be downloaded by the user terminal of the second user or may allow the coupon to be downloaded on the user account of the second user or may allow the coupon to be transferred to on the user account of the third party server of the second user or may allow the coupon to be transferred to a printing device, for example, a printer.
[0061] The account managing unit 240 may allow any benefit corresponding to the coupon to be accumulated on the user account of the first user who has generated the coupon. Namely, the account managing unit 240 may allow a predetermined benefit to be accumulated, as a benefit for the generation of the image or coupon, on the user account of the first user who has generated the image or the coupon. Whenever the benefits are accumulated, the account managing unit 240 may notify to the first user in a form of a message or an e-mail or a push message the benefits have been accumulated.
[0062] Here, the benefit may be an existing goods or a virtual money. The benefit amount may be a price corresponding to a predetermined ratio of the goods sale amount corresponding to the coupon. For example, part of the amount accumulated on the user account of the third user may be accumulated, as a benefit, on the user account of the third user, and the amount of the user account of the third user may be deducted by as much as the accumulated amount. Therefore, when the benefit is accumulated, part of the coupon information may be stored in the user account.
[0063] The account managing unit 240 may confirms the use of the coupon. When the use of the coupon is confirmed (namely, if it is confirmed that the second user uses the coupon at the shop corresponding to the coupon), the benefit corresponding to the coupon may be accumulated on the user account of the first user.
[0064] The account managing unit 240 may accumulate the benefit corresponding to the coupon on the user account of the first user if it obtains a user identification information of the second user who wants to the coupon together with the coupon use confirmation request.
[0065] The account managing unit 240 may accumulate the benefit corresponding to the coupon on the user account of the first user only if the confirmation time of the coupon is within a predetermined range after the generation time of the coupon.
[0066] In order to perform the accumulation of the benefit in the above way, the account managing unit 240 may manage the user accounts of each of the first user, the second user and the third user.
[0067] The account managing unit 240 may manage the user account of the first user. For example, the account managing unit 240 may store an information on the total amount on the benefit that the first user has accumulated and may store any history (for example, the statistical history on the accumulation of the coupon information which was a ground of the accumulation of the benefit or the shop identification information corresponding to the coupon which was a ground of the accumulation of the benefit or a third party server identification information with which the coupon being a ground of the accumulation of the benefit has been provided. In addition, the account managing unit 240 may allow the first user to freely use the benefit accumulated on the user account of the first user at the shop registered in the coupon issuing system 100 . At this time, the shop registered in the coupon issuing system 100 means a shop which may be recognized as an exchange value that the benefit accumulated on the user account of the coupon issuing system 100 is sold at the shop.
[0068] The account managing unit 240 may manage the user account of the second user. The account managing unit 240 , therefore, may confirm if the second user who requests the coupon confirmation is a user (namely, the user who has a history on the previous use of the same coupon) who has a history on the coupon confirmation request on the same coupon. If the second user received before the discount benefit using the same coupon, the benefit is not accumulated on the user account of the first user or any benefit is not provided to the second user.
[0069] In addition, the account managing unit 240 may manage the user account of the third user. For example, it may store the shop information, the shop identification information, etc, which match with the third user or may store a coupon use history (for example, a coupon use frequency, an information on the users who have generated the coupons matching with the shops, etc.) or may generate and store a statistical data based on the above history so that the third user can read.
[0070] The account managing unit 240 may manage any information on the acquaintance relationship between the users registered in the coupon issuing system 100 .
[0071] The account managing unit 24 may allow the sharing of the coupon between the users who have acquaintance relationship and may provide an evaluation interface to evaluate the first users who have generated the coupons, whereupon the second user who has downloaded the coupon generated by the first user can evaluate the first user, so other users can confirm that the coupons generated by the first user are reliable coupons.
[0072] Each component of the above coupon issuing system 100 may be implemented on any device of the user terminal 10 or the coupon issuing server 20 . Each of the coupon generating unit 220 , the coupon issuing unit 230 and the account managing unit 240 may be implemented on the coupon issuing server 20 .
[0073] The coupon issuing method according to an exemplary embodiment in FIG. 3 may include steps which are time series processed by the coupon issuing system 100 in FIGS. 1 and 2 . Therefore, if there are any contents which were omitted, the above contents on the coupon issuing system 100 in FIGS. 1 and 2 may apply to the coupon issuing method according to an exemplary embodiment in FIG. 3 .
[0074] The configuration in FIG. 3 will be described later with reference to FIGS. 4 to 7 , and FIGS. 4 to 7 are views illustrating a coupon issuing method according to an exemplary embodiment of the present invention.
[0075] The coupon issuing method may be may be executed in case where a program for executing the coupon issuing method is installed at a user terminal or may be triggered when the user requests the generation of coupons.
[0076] As illustrated in FIG. 3 , the coupon issuing system 100 may obtain an image information and a shop identification information (S 310 ).
[0077] For this, the coupon issuing system 100 may obtain an image information through the photographing interface. For example, if the camera is provided as a photographing interface, the coupon issuing system 100 may obtain an image information in such a way to photograph a photographing target using the camera.
[0078] In addition, the coupon issuing system 100 may obtain a shop identification information through an input interface. For example, in order to obtain a shop identification information provided in a form of a QR code, the coupon issuing system 100 may provide a QR reader as an input interface, thus obtaining a shop identification information by photographing the shop identification information using the reader.
[0079] The obtainable image information and shop identification information may be simultaneously obtained by the coupon issuing system 100 .
[0080] The coupon issuing system 100 may first obtain an image information and then may provide an input interface to receive the shop identification information, whereupon the shop identification may be inputted through the input interface.
[0081] The coupon issuing system 100 may first obtain a shop identification information and then may provide a photographing interface to generate an image information based on the obtaining of the shop identification information, thus obtaining an image information.
[0082] FIG. 4 is a view for describing the coupon issuing method according to the present invention while showing a procedure wherein the image information is obtained.
[0083] On the user terminal 10 , the first user may first obtain a shop identification information which may be attached on a table of the shop where sells foods in a form of the QR code. As the shop identification information is obtained, the coupon issuing system 100 may provide a photographing interface which allows the user to photograph foods by operating the camera of the user terminal 10 . As illustrated in FIG. 4 , when the food 410 is photographed through the photographing interface, the coupon issuing system 100 may obtain the thusly photographed image as an image information.
[0084] When the image information and shop identification information are obtained in the above way, the coupon issuing system 100 may generate a coupon on the basis of the image information and shop identification information (S 320 ).
[0085] At this time, the coupon issuing system 100 may determine the matching of the image information and shop identification information on the basis of the position information of the image information. The coupon may be issued in case of matching. More specifically, the coupon issuing system 100 may generate a coupon only if in case where the position information of the image information is a shop “A”, the shop identification information of the shop “A” is received. If the shop identification information of a shop “B” is received, the generation of the coupon may be blocked.
[0086] FIG. 5 is a view for describing the coupon issuing method according to the present invention. It shows a coupon 500 issued based on the coupon issuing method according to the present invention.
[0087] As illustrated in FIG. 5 , a coupon 500 may include a coupon information. The coupon information may include, but is not limited to, an image information 510 , a benefit information 520 , a shop name information in shop information, a shop position information and shop contact information 540 and 550 , and a user identification information 560 of a first user.
[0088] For this, instead of the user identification information of the first user, a newly generated identification information may be added to the coupon information. For example, a newly generated identification information may be added to the coupon information in such a way to combine the user identification information of the first user and the user identification information (or shop identification information) of the third user matching with the shop.
[0089] The thusly generated coupon may be stored on the user account of the first user.
[0090] In addition, the coupon issuing system 100 may provide coupons (S 330 ).
[0091] The coupon issuing system 100 may upload coupons in order for the second user who may have access to the coupon issuing system 100 to download the coupon.
[0092] In addition, the coupon issuing system 100 may allow the coupon to be transferred to a third party server in such a way to transmit a coupon information to the third party server to which the second user may have access while communicating with the coupon issuing system.
[0093] For example, the coupon issuing system 100 may upload the coupon on the coupon issuing system 100 so that the second user who has an acquaintance relationship with the first user can read the coupon on the coupon issuing system 100 .
[0094] For example, the coupon issuing system 100 may transfer a coupon information to the account of the first user of the third party server which provides a SNS, and the third party server may upload the coupon on the user account of the first user of the third party server, thus providing the coupons. In addition, the second user who has an acquaintance relationship with the first user on the third party server may read the coupon posted on the user account of the first user of the third party server.
[0095] For example, the coupon issuing system 100 may transfer the coupon to the third party server which provides a chatting service. To this end, the third party server may share the coupons in a chatting room wherein the first user enters, thus providing the coupons. The second user who has an acquaintance relationship with the person who enters the chatting room can read the coupon.
[0096] FIGS. 6 and 7 are views for describing the coupon issuing method according to an exemplary embodiment of the present invention while showing a configuration of the coupon through the third party server.
[0097] Referring to FIG. 6 , the first user may post the coupon 610 together when posting a text 620 on the third party server. The second user who can read the text 620 because he has an acquaintance relationship with the first user may obtain the coupon on the reading interface 630 which allows the obtaining of the coupon. At this time, the coupon 610 may be posted in whole or as illustrated in FIG. 7 , part of the coupon may be posted, which allows to protect the natural purpose (for example, only the image information in the coupon information is allowed to share) of the third party server.
[0098] The coupon issuing system 100 may allow the selections of the coupon which will be provided to the second user based on the characteristic of the second user who may read the coupon. For example, if the category of the coupon that the second user read with the highest frequency is “pizzas”, only the coupon related with the pizza among the multiple coupons generated by the first user may be selected and provided to the second user. For example, if the location of the second user is “Pusan”, only the coupon which may be used only at Pusan among the multiple coupons may be selected and provided to the second user.
[0099] The second user may store the thusly posted coupon on the account of himself or may download through the user terminal controlled by himself.
[0100] The coupon issuing system 100 may confirm if the coupon was used by the second user (S 340 ).
[0101] For example, if the shop corresponding to the coupon is an offline shop, when there is an input containing a notification that a coupon has been received from the terminal (for example, POS terminal) of the offline shop (for example, if a coupon identification information is received or there is an input wherein a third user confirms that the coupon has been received), the coupon issuing system 100 may confirm that the coupon has been used. For example, if the shop corresponding to the coupon is an online shop, when a coupon information is inputted as an item is purchased at the online shop, the use of the coupon can be confirmed.
[0102] When the use of the coupon is confirmed, points may be accumulated on the user account of the first user (S 350 ). At this time, only if the confirmation time is over a predetermined range as compared to the generation time of the coupon, the points can be accumulated on the user account of the first user. In addition, any benefits may be accumulated on the user account of the first user only if the user identification information of the second user who wants to use the coupon is obtained. At this time, the user identification information of the second user may be formed with a series of characters or numbers or may be implemented with a one-dimensional barcode, a two-dimensional barcode, a three-dimensional barcode, etc. or may be implemented with a RFID tag or a NFC tag.
[0103] The above steps 340 to 350 may be repeatedly performed whenever the confirmation of the coupon is requested. Therefore, the first user who has generated the coupon may be continuously guaranteed with the accumulations of the benefits for the generation of the coupon.
[0104] The first user may freely use the accumulated benefits at the shop registered in the coupon issuing system 100 . Whichever the benefits are accumulated, the first user can purchase using such benefit an item that he wants to at a shop wherein the use of the benefit is affiliated.
[0105] The second user who used the coupon generated by the first user may evaluate the first user.
[0106] The coupon issuing method according to the exemplary embodiment described in FIG. 3 may be implemented using a recording medium which includes commands executable by a computer like a program module executed by the computer. The computer readable medium may be a predetermined available medium to which the computer may access or may be a volatile medium, a non-volatile medium, a separable medium or a non-separable medium. In addition, the computer readable medium may include a computer storing medium and a communication medium. The computer storing medium may include a computer readable command, a data structure, a program module or a predetermined method for storing information like other data or a volatile medium, a non-volatile medium, a separable medium or a non-separable medium which may be implemented with technologies. The communication medium may include a typical computer readable command, a data structure, a program module, other data of modulated data signals like carrier waves, other transfer mechanisms, etc. and may include a predetermined information transfer medium.
[0107] As the present invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, it should also be understood that the above-described examples are not limited by any of the details of the foregoing description, unless otherwise specified, but rather should be construed broadly within its spirit and scope as defined in the appended claims, and therefore all changes and modifications that fall within the meets and bounds of the claims, or equivalences of such meets and bounds are therefore intended to be embraced by the appended claims.
[0108] The scope of the present invention may be defined by the claims below. It should be understood that all modifications or modified configurations which may be derived from the meaning, scope and equivalent concepts of the claims should be included in the scope of the present invention.
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Provided is a coupon issuing method and to a coupon issuing system which concerns a coupon issuing method implemented by means of a coupon issuing system capable of interaction with a user, the method comprising the steps of: acquiring image data and store identification data generated by the user, generating a coupon on the basis of the image data and store identification data; and issuing the generated coupon.
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BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a first side elevational view of the construction machine of the present invention.
FIG. 2 is a second side elevational view of the construction machine.
FIG. 3 is a plan view of the construction machine.
FIG. 4 is an elevational view of one of the transporters of the construction machine taken along line 4--4 of FIG. 3.
FIG. 5 is a plan view of a portion of the central frame of the construction machine showing the rams and hydraulic circuit utilized to pivot the transporters for steering.
FIG. 6 is a top view of the steering assembly of the construction machine.
FIG. 7 is a bottom view of the steering assembly. FIG. 8 is a partial cross-section of the steering assembly taken along line 8--8 of FIG. 6.
FIG. 9 is a cross-section of a ternary link mount in the steering assembly taken along the line 9--9 of FIG. 6.
FIG. 10 is a bottom view of one of the transporter representation members showing the mounting of one of the blocked-center valves thereon.
FIG. 11 is a cross-section taken along line 11--11 of FIG. 10.
FIG. 12. is a schematic representation of the linkage assembly of the steering assembly.
FIG. 13 is another schematic representation of the linkage assembly of the steering assembly.
FIG. 14 is a schematic representation of the chassis of the construction machine showing a preferred mode of steering thereof.
FIG. 15 is a plan view of portions of the feedback assembly utilized in steering the construction machine.
FIG. 16 is a perspective view of one of the stringline support assemblies.
FIG. 17 is a perspective view of the first indicator subassembly of the indicator assembly.
FIG. 18 is a perspective view of the third indicator subassembly of the indicator assembly.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings in general and to FIGS. 1, 2, and 3 in particular, shown therein and designated by the general reference numeral 30 is a construction machine constructed in accordance with the present invention. In general, the construction machine 30 comprises: a chassis 32, constructed above a central frame 34 and having a forward end 36, a rear end 38, a first side 40 and an opposing second side 42 (FIG. 3), the sides 40, 42 extending generally between the ends 36, 38 of the chassis 32; a plurality of transporters 44 and 46 (FIG. 1), and 48 and 50 (FIG. 2) which support the chassis 32 above a work surface 52 and, as will be described below, move the machine 30 therealong; a cutting tool 54 (indicated in dashed lines in FIGS. 1, 2 and 3) disposed on a medial portion of the chassis 32 for forming a cut 56 in the work surface 52 as the machine 30 is moved therealong; a first grade averaging assembly 58 (FIG. 1, 3) disposed generally adjacent the first side 40 of the chassis 32 and having a first forward stringline support apparatus 60 pivotally connected to the forward end 36 of the chassis 32 and a first rear stringline support apparatus 62 pivotally connected to the rear end 38 of the chassis 32; a second grade averaging assembly 64 (FIGS. 2, 3) disposed generally adjacent the second side 42 of the chassis 32 and having a second forward stringline support apparatus 66 pivotally connected to the forward end 36 of the chassis 32 and a second rear stringline support apparatus 68 pivotally connected to the rear end 38 of the chassis 32; and an indicator assembly comprised of a first indicator sub-assembly 70 (FIG. 1) disposed on the first side 40 of the chassis 32 near a first end 72 of the cutting tool 54, a second indicator sub-assembly 74 (FIG. 2) disposed on the second side 42 of the chassis 32 near a second end 76 of the cutting tool 54 and a third indicator sub-assembly 78 (FIG. 1) disposed generally on the first side 40 of the chassis 32 near the rear end 38 thereof. As shown in FIGS. 1 and 2, two of the transporters, 44 and 46, are disposed on the first side 40 of the chassis 32, the transporter 44 near the forward end 36 of the chassis 32 and the transporter 46 near the rear end 38 of the chassis 32, and two of the transporters, 48 and 50, are disposed on the second side 42 of the chassis 32, the transporter 48 near the forward end 36 of the chassis 32 and the transporter 50 near the rear end 38 of the chassis 32, as will be discussed below, the transporters 44-50 are arranged in a rectangular array on the chassis 32. By means which will be presently discussed, the transporters 44-50 are pivotally mounted on the chassis for pivotation about axes 80, 82 (FIG. 1), 84 and 86 (FIG. 2) respectively, the axes 80-86 extending substantially perpendicularly to the work surface 52, and each transporter is driven in rolling engagement with the work surface 52 (one transporter 46 engages portions of the work surface 52 within the cut 56) so that the machine 30 can be moved along the work surface 52 and such movement can be guided, or steered, by concertedly pivoting the transporters 44-50 such that the lines of rolling contact thereof with the work surface 52 are formed into a preselected pattern with respect to the chassis 32. Similarly, the transporters 44-50 are axially positionable on the chassis 32, along the axes 80-86 so that the chassis 32 can be positioned in height and attitude relative to the work surface 52 and such positioning is utilized to position the cutting tool 54 to set the profile of the cut 56. In the preferred embodiment of the machine 30, motive power for the operation of components of the machine 30 is provided by pressurized hydraulic fluid, as will be discussed below, and the machine 30 is provided with a prime mover (not shown), such as a deisel engine, and a plurality of hydraulic pumps (not shown--one pump 88 has been schematically indicated in FIG. 5) to supply the pressurized hydraulic fluid.
The mounting of the transporters 44-50 on the chassis 32 has been shown in FIG. 4 for the transporter 46 disposed on the first side 40 of the chassis 32 near of rear end 38 thereof. With exceptions to be noted below, the transporters 44, 48 and 50 are indentical to the transporter 46 and are mounted in an indentical manner so that it will not be necessary for purposes of the present disclosure to provide a detailed description of each of the transporters 44-50 and the manner of mounting thereof on the chassis 32. Rather, it will suffice to describe the transporter 46 and the mounting thereof on the chassis 32 and to note the differences between the transporter 46 and the transporters 44, 48 and 50 and the difference in the mounting between transporter 46 and transporters 44, 48 and 50.
For the purpose of mounting the transporter 46b on the chassis 32, the chassis 32 includes a mounting well 90 which is secured to the chassis 32 in any convenient manner as, for example, via a beam 92 welded to the central frame 34 of the chassis 32. The mounting well 90 has a cylindrical portion 94 having an axis coinciding with the axis 82 of pivotation of the transporter 46 and the upper end of the mounting well 90 is closed by a cap 96 secured in any convenient manner to the cylindrical portion 94. An aperture 98 is formed in the cap 96 of the mounting well 90 for a purpose to be described below. Mounting wells 100, 102 and 104 are similarly provided for the transporters 44, 48 and 50 (FIGS. 1, 2 and 3) and the mounting wells 100, 102 and 104 differ from the mounting well 90 in that no apertures, such as the aperture 98, are formed in the caps of the mounting wells 100, 102 and 104. The mounting wells 90, 100-104 are disposed in a rectangular array in the preferred embodiment and, as will be clear from the description of the mounting of transporter 46 in mounting well 90, such description applying to the mounting of transporters 44, 48 and 50 in mounting wells 100-104, such arrangement of the mounting wells 90, 100-104 positions the transporters 44-50 in a rectangular array.
Referring again to FIG. 4, a lug 106 is mounted on the inner surface of the cap 96 and the lug 106 is connected to the piston rod of a hydraulic ram 108 which extends along the axis 82 of pivotation of the transporter 46. The body of the ram 108 is secured to the transporter 46 so that the transporter 46 can be moved axially along the axis 82 to raise and lower portions of the chassis near the first side 40 and the rear end 38 thereof. Similar rams (not shown) are provided for the transporters 44, 48 and 50 so that the chassis 32 can be positioned with respect to the work surface 52, both in attitude and height, via the rams in the mounting wells 90, 100, 102 and 104. A hydraulic control circuit (not shown), supplied with hydraulic pressure from one of the pumps (not shown) driven by the prime mover (not shown) is utilized for positioning the chassis 32 and the control circuit can be manually adjusted to position the chassis 32 or can be adjusted via hydraulic sensors to automatically position the chassis in accordance with a preselected reference. As will be described below, the grade averaging assemblies 58, 64 provide one such reference. The hydraulic control circuit is conventional and need not be described for purposes of the present disclosure.
A flange 110 is formed about the lower end of the cylindrical portion 94 of the mounting well 90 and a cylindrical sleeve 112, having an axis coinciding with the axis 82 and having a flange 114 extending about a medial portion thereof, is secured to the lower end of the mounting well 90 via bolts (not shown) passing through the flanges 110 and 114. A portion of the sleeve 112 extends into the mounting well 90 for securing a square-to-round adapter 116, utilized in pivoting the transporter 46 about the axis 82, and the lower end of the mounting well 90 s will now be described. The square-to-round adapter 116 has a cylindrical portion 118 which mates with the inner periphery of the sleeve 112 so that the square-to-round adapter 116 is supported for pivotation about the axis 82 by the sleeve 112. An exterior flange 120 at the upper end of the cylindrical portion 118 engages the upper end of the sleeve 112 and a circular feedback sheave 122, secured to the lower end of the square-to-round adapter 116 via bolts (not shown), engages the lower end of the sleeve 112 to axially position the square-to-round adapter 116 at the lower end of the mounting well 90 while permitting the square-to-round adapter 116 to pivot with respect thereto. (The feedback sheave 122 is a portion of the guidance system of the machine 30 and the structure thereof will be described in more detail below.) Interior flanges 124, 126 are formed on the interior periphery of the square-to-round adapter 116, at the upper and lower ends thereof respectively, and square apertures 128, 130 respectively, centered on the axis 82 and aligned such that the sides of aperture 130 are parallel to the sides of aperture 128, are formed through the flanges 124, 126 respectively.
The transporter 46 comprises a support shaft 132 which is formed of square tubing to mate with the apertures 128, 130 in the square-to-round adapter 116. The support shaft 132 passes through the square-to-round adapter 116 so that the support shaft 132 has an upper portion disposed in the mounting well 90 and a lower portion which extends out of the lower end of the mounting well 90. An annulus 134 (see also FIG. 18) is welded to the upper end of the support shaft 132 and a second square-to-round adapter 136, comprised of a circular plate having a square aperture formed through the center thereof, is welded to the support shaft 132 near the upper end thereof, the upper square-to-round adapter 136 slidingly engaging the inner periphery of the cylindrical portion 94 of the mounting well 90 so as to coact with the square-to-round adapter 116 to center the support shaft 132 about the axis 82. (The transporters 44, 48 and 50 differ from the transporter 46 in that no annulus, such as the annulus 134, is included in the transporter 44, 48 and 50. The purpose of the annulus 134 will be discussed below.)
An inverted L-shaped support bracket 138 is welded to the lower end of the support shaft 132 to support a ground engagement member 140 on the lower end of the support shaft 132 for rolling engagement with the work surface 52. In a preferred embodiment of the present invention, the ground engagement member 140 is a wheel rotationally driven about an axis 142, transverse to the axis 82 of the transporter 46, via a hydraulic motor 144 mounted on the bracket 138 and supplied with pressurized hydraulic fluid from one of the pumps (not shown) driven by the prime mover (not shown). However, as will be clear to those skilled in the art, the present invention is not limited to a wheeled machine; rather, the present invention encompasses tracked machines and the term "rolling engagement" as used herein means that portions of the groun engagement member 140 engaging the work surface 52 are instantaneously at rest.
For pivoting the transporter 46 about the axis 82, the transporter 46 includes a lever arm 146 (see also FIG. 5), which can be conveniently welded to the lower side of the feedback sheave 122. The lever arm 146 extends transversely to the axis 82 and has an aperture (not shown) near the extensive end thereof to permit the lever arm 146 to be pivotally connected to the piston rod of a hydraulic ram 148. As is more clearly shown in FIG. 5, the ram 148 extends along the exterior of the central 34 of the chassis 32 and the body thereof is pivotally connected to a vertical brace 150 welded to the central framework 34 so that the transporter 46 can be pivoted about the axis 82 by extending and retracting the piston rod of the ram 148.
With the exceptions noted above, the transporters 44, 48 and 50 are constructed and are connected to the chassis 32 in the same manner that the transporter 46 is connected to the chassis 32. In particular, as shown in FIG. 5, feedback sheaves 152, 154 and 156 are provided for the transporters 44, 48 and 50 respectively, and lever arms 158, 160 and 162 are welded to feedback sheaves 152, 154 and 156, respectively. Hydraulic rams 164, 166 and 168, connected between the lever arms 158, 160 and 162, respectively, and braces 170, 172 and 174, respectively, on the chassis 32 are utilized to pivot the transporters 44, 48 and 50 respectively about the axes 80, 84 and 86, respectively, in the same manner that the ram 148 pivots the transporter 46 about the axis 82. For purposes of describing the guidance system of the machine 30, the rams 148, 164 and 168 connected to the lever arms 146, 158, 160 and 162, respectively, of transporters 46, 44, 48 and 50, respectively, will be referred to herein as corresponding to such transporters 46, 44, 48 and 50.
As will be clear to those skilled in the art, steering of the construction machine 30 can be accomplished via the positioning of the totality of the transporters 44-50 about the axes 80-86 respectively. That is, the relative orientations of the transporters 44-50 are determinative of the motion of the machine 30 along the work surface 52 as the machine 30 is driven therealong via the hydraulic motors, such as the motor 144, of the transporters 44-50. For purposes of describing the steering of the machine 30 and the control thereof, conventions will be used herein to describe coactive relationships among pluralities of similar elements such as, for example, the coactive positioning of the transporters 44-50 to steer the machine 30. It will be clear that the machine 30 will move on a straight line path extending forwardly of the machine 30 at such times that the ground engagement members, such as the ground engagement member 140, of the transporters 44-50 roll along reference lines, indicated by numerals 176, 178, 180 and 182 for the transporters 44, 46, 48 and 50 respectively, extending longitudinally of the chassis 32 and directed forwardly of the chassis 32. (In FIG. 5, the forward end 36 of the chassis 32 is diposed above the portions of the frame 34 shown therein). Steering of the machine 30 is accomplished by concertedly pivoting the transporters 44-50 such that the lines along which the ground engagement members of the transporters 44-50 roll are displaced from the lines 176-182 in a coherent manner. For purposes of describing these pivotations, the directions of pivotation of the transporters 44-50 are defined with respect to the chassis and the definition of a direction of pivotation for one transporter 44-50 extends to all transporters 44-50. That is, where a first direction of pivotation is chosen for one transporter 44-50 to be counterclockwise pivotation of such transporter 44-50 on the chassis 32 as viewed from above the chassis 32, a counterclockwise pivotation of any transporter 44-50 on the chassis as viewed from above the chassis 32 will also be pivotation in a first pivotation direction. With this convention, first and second directions of pivotation of the transporters 44-50 designated 184 and 186 respectively, have been shown in FIG. 5 for purposes of describing the steering of the machine 30. A similar convention is utilized herein to describe the sense of hydraulic pressure supplied to the hydraulic rams 148, 164, 166 and 168. (As used herein, the term "sense of hydraulic pressure" denotes the supply of pressurized hydraulic fluid to one of two ports of a ram while draining hydraulic fluid from the other of the two ports so that one sense of hydraulic pressure will extend the piston of the ram while an opposite sense of hydraulic pressure will retract the piston of the ram.) That is, where hydraulic pressure is supplied to the ports of a ram to turn the transporter in correspondence therewith in the first direction 184, the sense of hydraulic pressure supplied to such ram will be referred to herein as a first sense of hydraulic pressure; where hydraulic pressure is supplied to the ports of a ram to turn the transporter in correspondence therewith in a second direction 186, the sense of hydraulic pressure supplied to such ram will be referred to herein as a second sense of hydraulic pressure. Thus, with the first and second directions of pivotation 184, 186 defined as shown in FIG. 5, a first sense of hydraulic pressure for the rams 148 and 164 will be a sense of hydraulic pressure supplied so as to extend the piston rods of the rams 148 and 164 while a first sense of hydraulic pressure for the rams 166 and 168 will retract the piston rods thereof.
Referring once again to FIG. 1, the construction machine 30 is provided with an operator's cabin 188, mounted high on the first side 40 of the chassis 32 and in a medial portion thereof with respect to the length of the chassis 32. A conventional steering mechanism 190 is mounted in the operator's cabin 188 and a portion of the steering mechanism 190 extends through the floor of the cabin 188 to connect to a transporter pivotation initiating assembly 192 which is mounted beneath the operator's cabin 188 and which is utilized to supply pressurized hydraulic fluid to the rams 148, 164, 166 and 168. For clarity of illustration, details of the construction of the transporter pivotation initiating assembly 192 have been omitted in FIG. 1 and FIGS. 6 through 11 have been provided to illustrate the preferred form of the transporter pivotation initiating assembly 192.
For reasons which will become clear below, it is convenient to orient the transporter pivotation initiating assembly 192 so as to align with the general front-rear, first side-second side layout of the chassis 32. Specifically, the central frame 34 has a first lower base beam 194 (FIG. 1), extending longitudinally along the underside of the chassis 32 and displaced toward the first side 40 of the chassis 32 from the center thereof, and a second lower base beam 196 (FIG. 2), extendng longitudinally along the underside of the chassis 32 parallel to the base beam 194 and displaced toward the second side 42 of the chassis 32 from the center thereof. As shown in FIG. 1, the transporter pivotation initiating assembly 192 is disposed a short distance above the base beam 194, 196 and the transporter pivotation initiating assembly 192 is positioned generally toward the first side 40 of the chassis 32 from the lower base beam 194. The transporter pivotation initiating assembly 192 is mounted within a case 198 which is oriented with respect to the base beams 194, 196 as has been illustrated for the first lower base beam 194 in FIGS. 6 and 7 wherein are shown top and bottom views respectively of the transporter pivotation initiating assembly 192.
Referring specifically to FIGS. 6, 7 and 8, the case 198 is constructed of a plurality of plates to form a rectangular parallelpiped-shaped enclosure, such plates including a forward end wall 200 disposed substantially perpendicularly to the first lower base beam 194 and extending generally toward the first side 40 of the chassis 32 therefrom; a rear end wall 202, substantially parallel to forward end wall 200 and displaced a distance rearwardly therefrom; an inner side wall 204 extending between the end walls 200, 202 substantially parallel to the first lower base beam 194 and displaced a short distance therefrom toward the first side 40 of the chassis 32; and an outer side wall 206 extending between the end walls 200, 202 substantially parallel to the inner side wall 204 and displaced a distance therefrom toward the first side 40 of the chassis 32. A bottom cover (not shown) extends across and closes the bottom of the case 198 and suitable connectors 208 (FIGS. 6 and 7) having threaded apertures formed therethrough for receiving bolts (not shown) inserted through holes in the bottom cover (not shown) are welded into the corners of the case 198 at the bottom thereof for connecting the bottom cover to remaining portions of the case 198. The top of the case 198 is closed by three plates which extend from the inner side wall 204 to the outer side wall 206, such plates including: a forward representation member mounting plate 210 (FIG. 6) extending along the forward end wall 200 and welded to the forward end wall 200 and the side walls 204, 206 (portions of the forward representation member mounting plate 210 have been cut away in FIG. 6 to show portions of the transporter pivotation initiating assembly 192 disposed within the case 198); a rear representation member mounting plate 212 extending along the rear end wall 200 and welded to the rear end wall 200 and the side walls 204, 206 (portions of the rear representation member mounting plate 212 have been cut away in FIG. 6 to show portions of the transporter pivotation initiating assembly 192 disposed within the case 198); and a central plate (not shown) welded between the representation member mounting plates 210, 212 and to the side plates 204, 206.
A flange 214 (FIG. 6) is welded to the exterior of the case 198 along the bottom edge of the inner side wall 204, the flange 214 extending the length of the inner side wall 204 and extending substantially perpendicularly from the inner side wall 204 toward the center of the machine 30. A flange 216 (FIG. 8) is welded to the interior of the case 198 a short distance from the top of the case 198, the flange 216 extending the length of the outer side wall 206 generally parallel to the representation member mounting plates 210, 212. On the exterior of the case 198, eight ribs 218 are welded to outer side wall 206, the ribs 218 extending from the top of the case 198 to the bottom thereof generally parallel to the end walls 200, 202 of the case 198. The purpose of the flanges 214, 216 and of the ribs 218 will be discussed below.
A bracket 220 is welded to the exterior of the case 198, on the forward end wall 200 thereof, for pivotally mounting the lower end of the stacking mechanism 190 on the case 198. The bracket 220 is mounted off center on the case 198 with respect to the side walls 204, 206, the bracket 220 being positioned nearer the inner side wall 204 than the outer side wall 206. The steering mechanism 190 includes a lug 222 near the lower end thereof, the lug 222 extending laterally of the bracket 220 generally toward the outer side wall 206 and the lower portions of the steering mechanism are mounted on the case 198 such that the lug 222 moves in an arc generally parallel to the top and the bottom of the case 198 in response to manual operation of the steering mechanism 190 by the operator of the machine 30. (Universal joints, not shown, in the steering mechanism 190 and bearing blocks 221, FIG. 6, and 223, FIG. 7, mounted on the bracket 220, are utilized to position portions of the steering mechanism 190 for such pivotation of the lug 222 in a conventional manner.) The lug 222 has a reference position, shown in FIGS. 6 and 7, wherein the lug extends along an axis 224 generally parallel to the forward end wall 200. The lug 222 is pivotable away from the axis 224, toward or away from the forward end wall 200 and, for purposes of description of the steering of the machine 30, the directions of pivotation of the lug 222 from the reference position thereof are designated herein as a first direction 226, wherein the extensive end of the lug 222 is moved toward the forward end wall 200 from the reference position of the lug 222, and as a second direction 228, wherein the extensive end of the lug 222 is moved away from the forward end wall 200 (FIGS. 6, 7). A circular aperture 230 (FIG. 7) is formed near the extensive end of the lug 222 and the aperture 230 is threaded for pivotally connecting the lug 222 to the transporter pivotation initiating assembly 192 as will be discussed below.
The transporter pivotation initiating assembly 192 includes a linkage assembly 234 including a first ternary link 236 and a second ternary link 238 which are pivotally mounted on the case 192 via a first link mount 240, mounting the first ternary link 236 on the inner side wall 204 of the case 198, and a second link mount 242, mounting the second ternary link 238 on the outer side wall 206 of the case 198. The link mounts 240, 242 are identical and extend from the side walls 204, 206 into the interior of the case 198 along a central line with respect to forward and rear end walls 200, 204 thereof.
FIG. 9, wherein is shown a cross-section of the first link moun 240, has been provided to illustrate the common structure of the link mounts 240, 242 and the manner in which the link mounts 240, 242 are utilized to mount the linkage assembly 234 on the case 198. The link mount 240 comprises a bar member 244 which is welded at one end thereof to the inner side wall 204 and extends substantially perpendicularly therefrom. A transverse circular bore 246 is formed through the bar member 244 near the extensive end thereof and bar member 244 is oriented on the case 198 such that the axis 248 of the bore 246 extends substantially parallel to the inner side wall 204 and substantially perpendicularly to the top and bottom of the case 198. A stud 250 is welded to the first ternary link 236 to mate with the bore 246 and the stud 250 extends through the bore 246 so as to journal the first ternary link 236 on the bar member 244. The first ternary link 236 is secured to the bar member 244 via a circular disc 252, having a diameter greater than the bore 246, bolted to the extensive end of the stud 250. A bearing 254, extending about the stud 250, is interposed between the first ternary link 236 and the bar member 244 and a bearing 256, similarly extending about the stud 250, is interposed between the disc 252 and the bar member 244 so that the first ternary link 236 is free to pivot about the axis 248 of the bore 246. The second link mount 242 (FIG. 6) similarly has a bar member 258 welded to the outer side wall 206 and the second ternary link 238 is mounted on the bar member 258 for pivotation about an axis substantially parallel to the axis 248 in the same manner that the first ternary link 236 is mounted on the bar member 244.
The ternary links 236, 238 are formed of flat metal plate and the studs which connect the links 236, 238 to the bar members 244, 258 are welded to one side of each of the links 236, 238 so that the pivotation axes of the links 236, 238 are substantially perpendicular to the planar configuration of the links 236, 238. As shown in FIG. 7, each of the ternary links has a triangular portion 260 (dotted lines have been utilized to delineate portions of the ternary links 236, 238 in FIG. 7) and the links 236, 238 are connected to the link mounts 240, 242 near the apices of the triangular portions 260. The first ternary link 236 has an ear portion 262 on the base of the triangular portion 260 thereof; that is, opposite the apex of the triangular portion 260 thereof. An aperture 264 is formed through an ear portion 262 and the aperture 264 is threaded. The lug 222 on the steering mechanism 190 is connected to the transporter pivotation initiating assembly 192 via an arm 266 which passes through a slot (not shown) in the forward end wall 200 of the case 198 and which is pivotally connected to the lug 222 and the ear 262. For this purpose, circular apertures 268 (FIG. 6) and 270 are formed in the arm 266, near the ends thereof, and spherical bearings 272, 274 are pressed into the apertures 268, 270. Bolts 276 and 278, inserted through the bearings 272, 274, are screwed into the apertures 230 and 264, in the lug 222 and the first ternary link 236 respectively, to pivotally secure the arm 266 to the lug 222 and the first ternary link 236.
Returning to FIG. 7, each of the ternary links 236, 238 has an ear 280 formed on the side thereof nearest the forward end wall 200 and threaded holes (not shown) are formed through the ears 280 of the ternary links 236, 238 about axes parallel to the pivotation axes of the ternary links on the case 198. A cross-arm 282, having spherical bearings pressed into circular apertures formed through portions of the cross-arm 282 near the ends thereof, is pivotally bolted to the ternary links 236, 238 via the threaded holes in the ears 280 thereof and via the spherical bearings in the cross-arm 282. The hole in the ear 280 of the second ternary link 238 is spaced from the axis of pivotation of the second ternary link on the case 198 a distance equal to he spacing between the hole in the ear 280 of the first ternary link 236 and the axis of pivotation of the first ternary link 236 on the case 198 and the spacing between the spherical bearings in the cross-arm 282 is the same as the distance between the axes of pivotation of the ternary links 236, 238 on the case 198. Thus, the axes of pivotation of the ternary links 236, 238 on the case 198 and of the cross arm 282 on the ternary links 236, 238 are positioned at the corners of a parallelogram so that a pivotation of the first ternary link 236 on the case 198 is accompanied by a pivotation, of equal magnitude, of the second ternary link 238 on the case 198.
As is the case with the lug 222, reference positions are defined for the ternary links and FIG. 7 has been drawn for the case wherein the ternary links 236, 238 are disposed in the reference positions thereof. In the reference positions, the triangular portions 260 of the ternary links 236, 238 are disposed symmetrically with respect to axes 284, 286, defined for the first and second ternary links 236, 238 respectively, which extend from the axes of pivotation of the ternary links 236, 238 along a line connecting the axes of pivotation of the ternary links 236, 238. (The positions of the holes in the ears 280 of the ternary links 236, 238 are selected such that the second ternary link 238 will be in the reference position thereof when the first ternary link 236 is in the reference position thereof.) The length of the arm 266 connecting the lug 222 to the first ternary link 236 is selected to position the first ternary link 236 and, accordingly, the second ternary link 238 in the reference positions thereof when the lug 222 is in the reference position thereof. Accordingly, the ternary links 236, 238 can be simultaneously pivoted away from the reference positions thereof by a pivotation of the lug 222 away from the reference position thereof in one of the first and second directions 226, 228. Further, the direction in which a ternary link 236, 238 is pivoted from its reference position depends on whether the lug 222 is pivoted in the first direction 226 or in the second direction 228. For purposes of description of the steering of the construction machine 30 to be given below, the direction of pivotation of either ternary link 236, 238 from the reference position thereof at such times that the lug 222 is pivoted in the first direction 226 thereof will be referred to herein as a first direction of pivotation of such ternary link 236, 238 and the opposing direction of pivotation of such ternary link 236, 238 from the reference position thereof will be referred to herein as a second direction of pivotation of such ternary link. The first directions of pivotation of the ternary links 236, 238 have been shown in FIG. 7 and are designated by the numerals 288 and 290 for the first and second ternary links respectively. Similarly, the second directions of pivotation are designated 292 and 294 in FIG. 7 for the first and second ternary links 236, 238 respectively.
Near the bases of the triangular portions 260 of the ternary links 236, 238, two threaded holes 296 are formed through each of the ternary links 236, 238 about axes parallel to the pivotation axes of the ternary links 236, 238. (For clarity of illustration, only one of the holes 296, through each ternary link 236, 238, has been numerically designated in the drawings.) The holes 296 in each ternary link 236, 238 are equidistant from the axis of pivotation of such ternary link 236, 238 on the case 198 and the holes 296 in the second ternary link 238 are spaced the same distance from the axis of pivotation of the second ternary link 238 that the holes 296 in the first ternary link 236 are spaced from the axis of pivotation of the first ternary link 236. The holes 296 are symmetrically positioned on the links 236, 238 with respect to the triangular portions 260 thereof. That is, at such times that the ternary links 236, 238 are in the reference positions thereof, all holes 296 are equally spaced from a line connecting the axes of pivotation of the ternary links 236, 238 and each hole is identically spaced toward the center of the case 198 from the axis of pivotation of the ternary link 236, 238 wherein such hole 296 is formed.
The linkage assembly 234 comprises two identical first intermediate links 298, 300 which are pivotally connected to the first ternary link 236 via spherical bearings pressed into circular apertures near one end of each first intermediate link 298, 300 and the holes 296 in the triangular portion 260 of the first ternary link 236. The linkage assembly 234 similarly comprises two second intermediate links 302, 304, identical to the first intermediate links 298, 300 and connected to the second ternary link 238 in the same manner that the first intermediate links 298, 300 are connected to the first ternary link 236. The opposite end of each intermediate link 298-304 is similarly provided with a spherical bearing and the spherical bearings near such opposite ends are utilized to pivotally connect the first intermediate links 298, 300 to first terminal links 306 and 308 respectively and to pivotally connect the second intermediate links 302, 304 to second terminal links 310 and 312 respectively. As is the case with the intermediate links 298-304, the terminal links 306-312 are identical and the structure of the terminal links 306-312 has been shown for the terminal link 306, in FIGS. 10 and 11. As shown therein, the terminal link 306 is a bar having a threaded, blind bore 314 formed near one end thereof for connection to the intermediate link 298 via a spherical bearing in the manner described above. Near the opposite end of the terminal link 306, a hole 316 is formed through the terminal link 306 parallel to the hole 314. A slit 318, extending radially from the hole 316, is formed in the terminal link 306 between the hole 316 and the end of the terminal link 306 nearest the hole 316 to permit the terminal link 306 to be clamped to a shaft inserted through the hole 316 via a bolt 320 screwed into a partially threaded hole 322 formed transversely through portions of the terminal link 306 wherein the slit 318 is formed. A hole 324 is formed through the terminal link 306 substantially parallel to the holes 314 and 316 and substantially midway therebetween for a purpose to be described below. The termnal links 306-312 are mounted within the case 198, as will be described below, such that the axes of the holes formed therein for connection to the intermedate links 298-304 are parallel to the axes of pivotation of the ternary links 236, 238 on the case 198 so that the linkage assembly 234 has a generally flat structure and components thereof pivot in arcs generally parallel to the top and bottom of the case 198 in response to pivotation of the lug 222 of the steering mechanism 190.
Referring once again to FIGS. 6, 7 and 8, the transporter pivotation initiating assembly 192 further comprises four transporter representation members 326-332 which have the form of circular sheaves and which are placed in a rectangular array disposed symmetrically with respect to the pivotation axes of the ternary links 236, 238. That is, a rectangle formed by lines extending between the centers of the transporter representation members 326-332 is bisected both by a line extending between the axes of pivotation of the ternary links 236, 238 and the perpendicular bisector of such line.
The transporter representation members 326-332 are grouped into two pairs, a pair of first transporter representation members comprising the transporter representation members 326 and 328 and a pair of second transporter representation members comprising the transporter representation members 330 and 332, for purposes of connecting the transporter representation members 326-332 to the linkage assembly 234 in a manner to be described below. Specifically, the pair of first transporter representation members 326, 328 are disposed near the inner side wall 204 of the case 198 on opposite sides of the first ternary link 236 and are associated with the first ternary link 236 by connection to the first terminal links 306, 308 respectively as will be described below. Similarly, the pair of second transporter representation members 330, 332 are disposed near the outer side wall 206 of the case 198 on opposite sides of the second ternary link 238 and are associated with the second ternary link 238 via connection to the second terminal links 310, 312 respectively, as will be described below.
The transporter representation members 326-332 are pivotally mounted on the case 198, for pivotation about the symmetry axes thereof, in a common manner that has been shown for the transporter representation members 328 and 332 in FIG. 8 and for the transporter representation member 326 in FIG. 11. As shown in FIG. 8, spaced apart cylindrical studs 334, 336 are welded to the rear representation member mounting plate 212 and extend therefrom into the interior of the case 198 about axes 338, 340 respectively which are parallel to the axes of pivotation of the ternary links 236, 238 on the case 198. Circular bores 342, 344 are formed through the transporter representation members 328, 332 respectively about the symmetry axes thereof and the bores 342, 344 mate with the perpheries of the studs 334, 336 respectively to journal the transporter representation members 328, 332 on the case 198. Similar studs (one such stud is shown in FIG. 11) are provided on the forward representation member mounting plate 210, such studs being spaced a distance equal to the spacing of the studs 334 and 336, and the transporter representation members 326 and 330 are similarly provided with bores for mounting the transporter representation members 326, 330 on the forward representation member mounting plate 210. The manner in which the transporter representation members 326-332 are secured to the studs is more particularly shown for the mounting of the transporter representation member 326 on the forward representation member mounting plate 210 in FIG. 11 wherein the stud for mounting the transporter representation member 326 has been designated by the numeral 346, the bore through the transporter representation member 326 has been designated by the numeral 348 and the axis of the stud 346 has been designated by the numeral 350. As shown in FIG. 11, a disc 352, having a diameter larger than the bore 348 bolts to the extensive end of the stud 346 so that the transporter representation member can be mounted on the stud 346 by slipping the transporter representation member 326 thereon with the disc 352 removed and the transporter representation member 326 is then secured to the stud 346 by bolting the disc 352 to the stud 346. Suitable bearings 354 are interposed between the representation member mounting plate 210 and the transporter representation member 326 and between the transporter representation member 326 and the disc 352 so that the transporter representation member 326 can pivot about the axis 350 of the stud 346. Similar discs and bearings are provided for the transporter representation members 328, 330 and 332. The studs which mount the transporter representation members 326-332 are positioned on the plates 210, 212 to form the transporter representation members into the rectangular array noted above.
For purposes which will become clear below, the first transporter representation members 326, 328 are constructed differently from the second transporter representation members 330, 332 and such differences in structure have been shown in FIGS. 6 and 8. Each of the first transporter representation members 326, 328 has a groove formed circumferentially in the outer circular periphery thereof adjacent the side of the transporter representation member, 326 or 328, nearest the representation member mounting plate, 210 or 212, respectively, whereon the first transporter representation members 326 and 328 are mounted. (The groove in the first transporter representation member 328 is shown in FIGS. 6 and 8 and designated by the numeral 353 therein.) Each of the second transporter representation members 330, 332 has a groove formed circumferentially in the outer circular periphery thereof adjacent the side of the transporter representation member, 330 or 332, farthest from the representation member mounting plate, 210 or 212 respectively, whereon the second transporter representation members 330 and 332 are mounted. (Such groove in the second transporter representation member 332 is shown in FIG. 8 and designated 335 therein.) The grooves 353, 355 in the transporter representation members 328, 332, and corresponding grooves in the transporter representation members 326, 330, are formed on a common radius which has been shown for the groove 355 in FIG. 8 and designated by the numeral 356 therein. The second transporter representation members 330, 332 are further provided with circumferential grooves 357, 358 respectively, (FIG. 6) formed to intersect the sides of transporter representation members 330, 332 nearest the representation member mounting plates 210, 212 respectively whereon the transportation representation members 330, 332 are mounted. The groove 358 is aligned with the groove 353 in transporter representation member 328 and the groove 357 is aligned with the groove (not shown) in transporter representation member 326, such groove in transporter representation member 326 corresponding to the groove 353, for a purpose to be described below.
Referring specifically to FIG. 7, the transporter representation members 326, 328, 330, 332 are connected to the linkage assembly 324 via four identical rotary, four-way, blocked-center hydraulic valves 360, 362, 364, 366 respectively which are connected between the transporter representation members 326, 328, 330, 332 and the terminal links 306, 308, 310 and 312 respectively. The manner in which the valves 360-366 connect the transporter representation members 326-332 to the terminal links 306-312 is the same for all valves 360-366 and such manner of connection has been shown for the valve 360, the transporter representation member 326 and the terminal link 306 in FIGS. 10 and 11.
The valve 360 has a case 368 and a valve member (not shown) pivotally mounted within the case 368. Inlet ports 370, 372 and outlet ports 374, 376 are provided on the case 368 so that, when inlet port 370 is connected to a hydraulic pump such as the pump schematically indicated and designated by the numeral 88 in FIG. 5 and inlet port 372 is connected to a sump, schematically indicated and designated by the numeral 378 in FIG. 5, from which hydraulic fluid is supplied to such pump, pressurized hydraulic fluid can be supplied to a selected one of the outlet ports 374, 376 and drained from the other of the outlet ports 374, 376 by a pivotation of the valve member (not shown) of the valve 360 in a selected direction from the blocked-center position thereof. Thus, the valve 360 can supply a hydraulic ram connected to the outlet ports 374, 376 thereof with no pressure, when the valve 360 is in blocked-center positioned thereof, a first sense of hydraulic pressure in response to a pivotation of the valve member in one direction from the blocked-center position thereof, and a second sense of hydraulic pressure in response to a pivotation of the valve member in the other direction from the blocked-center position thereof. Moreover, the direction in which the valve member is to be pivoted to supply a first or second sense of hydraulic pressure to a ram is selectable by the connection of the ram to the valve; that is, by the choice of which of two hydraulic conduits connected to the ram is connected to the outlet port 374 and which is connected to the outlet port 376. In the present invention, selection rules are utilized to select the valve 360-366 to be connected to a particular ram 148, 164-168 and to select the direction in which a valve member is to be turned to supply a first sense of hydraulic pressure to the particular ram to which each valve 360-368 is connected. These selection rules will be discussed in detail below.
The case 368 of the valve 360 is mounted on one side of a bracket 380 having the general form of an elongated plate and the case 368 is mounted adjacent one end of the bracket 380. Near the other end of the bracket 380, a bore 382 is formed therethrough parallel to the pivotation axis 384 of the valve member of the valve 360 and the bore 382 is dimensioned to receive the disc 352, which holds the transporter representation member 326 on the forward representation member mounting plate 210, and the bearing 354 interposed between the disc 352 and the transporter representation member 326. As shown in FIGS. 10 and 11, the valve 360 is assembled to the transporter representation member 326 by abutting the side of the bracket 380, opposite the side thereof upon which the valve 360 is mounted, to the transporter representation member 326 with the bore 382 centered on the pivotation axis 350 of the transporter representation member 326 and bolting the bracket 380 to the member 326.
The mounting of the valve 360 near one end of the bracket 380 and the centering of the bore 382, near the opposite end of the bracket 380, on the pivotation axis 350 of the transporter representation member 326 displaces the axis 384 of pivotation of the valve member of the valve 360 a preselected distance from the pivotation axis 350 as has been shown in FIG. 11. As will be explained below, such displacement enhances the operation of the transporter pivotation initiating assembly 192 but the present invention is not limited to the inclusion of such a displacement in the mounting of the valve 360-366 on the transporter representation members 326-332. As used herein, the words parallel as applied to the axis of pivotation of a transporter representation member 326-332 and the valve member of a valve 360-366 mounted thereon includes coincidence of such axes of pivotation.
The valve member of the valve 360 is mounted on a shaft 386 which extends through a cover 388 of the valve case 368 along the pivotation axis 384. The shaft 386 is sized to mate with the hole 316 through the terminal link 306 and the valve 360 is connected to the linkage assembly 234 by inserting the shaft 386 into the hole 316 and tightening the bolt 320 to clamp portions of the terminal link 306 about the hole 316 on the shaft 386 in the conventional manner.
The terminal links 306-312 each have a reference position with respect to the respective transporter representation members 326-332 mounting the valves to which the terminal links are connected and these reference positions are defined with regard to the blocked-center positions of the valve members of the valves 360-366 and with regard to a line between the pivotation axes of the valve members and the transporter representation members 326-332 as will now be explained for the terminal link 306. Prior to clamping the terminal link 306 to the shaft 386, the shaft 386 is positioned to place the valve member of the valve 360 in the blocked-center position thereof. The terminal link 306 is then positioned about the shaft 386 such that the center of the hole 314 utilized to connect the terminal link 306 to the intermediate link 298 is disposed on a line 390 which intersects the pivotation axes 350 and 384 as shown in FIG. 10. The terminal link 306 is clamped to the shaft 386 as has been described above. The angular disposition of the terminal link 306 with respect to the transporter representation member 326 such that the above described alignment of the hole 314 and the axes, 350, 384 occurs is defined herein as the reference position of the terminal link 306 with respect to the transporter representation member 326. The reference positions of the terminal links 308, 310, and 312 with respect to the transporter representation members 328, 330 and 332 respectively are defined in the same manner. (Should the valves 360-366 be positioned on the transporter representation members 326-332 such that the axes of pivotation of the valve members of the valves 360-366 coincide with the axes of pivotation of the transporter representation members 326-332, the reference positions of the links 306-312, with respect to the transporter representation members 326-332, can be selected arbitrarily subject only to the condition that the valve members of the valves 360-366 are in the blocked-center positions thereof in the reference positions of the links 306-312.)
An arcuate slot 392 is formed in the surfaces of the cover 388 of the valve 360 adjacent the link 306 and underlying the hole 324 in the link 306 in the reference position of the link 306. A pin 394, driven through the hole 324, extends into the slot 392 to limit the pivotation of the valve member of the valve 360 from the blocked-center position thereof in order to prevent a reversal of the operation of the valve 360 which would result should the valve member of the valve 360 be turned through too large an angle from the blocked center position thereof.
The above described construction of the transporter pivotation initiating assembly 192 permits each of the transporter representation members 326-332 to assume either of two positions at such times that the ternary links 236, 238 and the terminal links 306-312 are in the reference positions thereof. For example, referring to the transporter representation member 326 and the terminal link 306 in FIG. 7, terminal link 306 can extend generally toward the inner side wall 204 from the shaft 386 at such times that the terminal link 306 is in the reference position thereof on the transporter representation member 326 and the first ternary link 236 is in the reference position thereof. However, terminal link 306 can also extend generally toward the outer side wall 206 from the shaft 386 at such times that the ternary link 236 and the terminal link 306 are in the reference positions thereof as defined above. For purposes of establishing a preferred mode of steering for the construction machine 30, reference positions for the transporter representation members 326-332 are defined in accordance with a selection rule as follows: the reference position of a transporter representation member is that position thereof wherein the terminal link connected thereto via one of the valves will be in the reference position thereof on the transporter representation member and will extend toward the nearer of the side walls 204, 206 to the transporter representation member whereon such terminal link is mounted when the ternary links 236, 238 are in the reference positions thereof.
The above grouping of the intermediate links 298-304, the terminal links 306-312 and the transporter representation members 326-332 into pairs of first intermediate links, first terminal links and first transporter representation members and into pairs of second intermediate links, second terminal links and second transporter representation members divides the linkage assembly into a first linkage sub-assembly into a first linkage sub-assembly 407, based on the first ternary link 236 and including the first intermediate links 298, 300 and first terminal links 306, 308, and into a second linkage sub-assembly 409, based on the second ternary link 238 and including the second intermediate links 302, 304 and second terminal links 310, 312. With the reference positions of the ternary links 236, 238, the terminal links 306-312 and the transporter representation members 326-332 defined as above, the first linkage sub-assembly 407 connects the pivotation axis of the first terminal link 306 on the first transporter representation member 326 (via the connection of the first terminal link 306 to the shaft of the valve 360) to the pivotation axis of the first terminal link 308 on the first transporter representation member 328 through a plurality of link arms which lie along a zig-zag path as has been shown in solid lines for the reference positions of the ternary links 236, 238, the reference positions of the terminal links 306-312 and the reference positions of the transporter representation members 326-332 in FIGS. 12 and 13. A similar plurality of link arms forming a zig-zag path connect the pivotation axes of the second terminal links 310, 312 on the second transporter representation members 330, 332 respectively, and such path has similarily been shown in solid lines for the reference positions of the ternary links 236, 238, the terminal links 306-312 and the transporter representation members 326-332 in FIGS. 12 and 13. (FIGS. 12 and 13 have been drawn to show the link arms from a viewpoint above the linkage assembly 234 and corresponds to the view of the transporter pivotation initiating assembly 192 in (FIG. 6.) In FIGS. 12 and 13, link arms provided by the intermediate links and the terminal links have been designated by the numerals used to designate the intermediate links and terminal links in FIG. 7. Link arms formed by portions of the first ternary link 236 between the axis of pivotation thereof on the case 198 and the two first intermediate links 298, 300 have been designed 402 and 404 respectively and link arms formed by portions of the second ternary link 238 between the axis of pivotation thereof on the case 198 and the two second intermediate links 302, 304 have been designated 406 and 408 respectively. Also shown in FIGS. 12 and 13 are arms between the shafts of the valves 360-366 and the pivotation axes of the transporter representation members 326-332 on the case 198, such arms being designated 410-416 for the transporter representation members 326-332 respectively. (For clarity of illustration, linkages formed by the arm 266 connected the lug 222 to the first ternary 236 and the cross-arm 282, interconnecting the ternary links 236, 238, have not been shown in FIGS. 12 and 13.) In addition to showing the form of the linkage assembly 234 for the reference positions of the ternary links 236, 238, the terminal links 306-312 312 and the transporter representation members 326-332, FIGS. 12 and 13 further show the form of the linkage assembly 234 for two additional cases. In FIG. 12, the form of the linkage assembly 234 is shown in dashed lines for the case wherein the ternary links 236, 238 have been pivoted in the first directions of pivotation 288, 290 thereof from the reference positions thereof while the transporter representation members 326-332 are in the reference positions thereof on the case 198. (For clarity of illustration, pivotations of the terminal links 306-312 in FIG. 12 have been exaggerated. It will be clear from the above description of the terminal link 306 that the pin 394 engaging the arcuate slot 392 in the cover 388 of the valve 360 will prevent the terminal link 306 from pivoting through the angle shown in FIG. 12 and similar limitations are imposed on the terminal links 308-312. It will also be clear, from the following, that such limitations on the pivotation of the terminal links 306-312 will not limit the operation of the transporter pivotation initiation assembly 190.) Dashed lines in FIG. 13 show the form of the linkage assembly 234 for the case wherein the ternary links 236, 238 have been pivoted in the first directions of pivotation 288, 290 thereof from the reference positions thereof while the terminal links 306-312 are in the reference positions thereof on the transporter representation members 326-332.
As will be clear from FIG. 12, a pivotation of the ternary links 236, 238 in the first directions of pivotation 288, 290 thereof from the reference positions thereof at such times that the transporter representation members 326-332 are in the reference positions thereof establishes a pattern of pivotations of the terminal links 306-312 from the reference positions thereof on the transporter representation members 326-332. Such pattern of pivotation of the terminal links 306-312, referred to herein as a first pattern of pivotation of the terminal links 306-312, is defined by the totality of pivotations of the terminal links 306-312 in response to pivotations of the ternary links 236, 238 in the first directions of pivotations 288, 290 thereof and will be characterized below in terms of each terminal link 306-312 pivoting in a selected one of a first direction and a second direction defined with respect to the transporter representation member 326-332 whereon such terminal link 306-312 is mounted and defined by means of selection rules to be discussed below. Similarly, pivotations of the ternary links 236, 238 in the second directions of pivotation 292, 294 thereof define a second pattern of pivotation (not shown) for the terminal links 306-312 wherein the terminal links 306-312 are pivoted in directions opposite to the directions of pivotation thereof in the first pattern of pivotation of the terminal links 306-312.
As will be clear to those skilled in the art, the angles through which the first terminal links 306, 308 pivot in response to a specific angle of pivotation of the first ternary link 236, for the case wherein the first transporter representation members 326 and 328 are in the reference positions thereof, need not be equal and, similarly, the second terminal links 310, 312 need not undergo equal pivotations in response to a pivotation of the second ternary link 238 at such times that the second transporter representation members 330 and 332 are in the reference positions thereof. Rather, the relative magnitudes of pivotations of the first terminal links 306, 308 and of the second terminal links 310, 312 for a specific pivotation of the ternary links 236, 238 can be adjusted by selecting the lengths of the link arms of the linkage assembly 234 and the lengths of the arms 410-416 shown in FIGS. 12 and 13. Such adjustment will be discussed below.
However, the symmetry of the linkage subassemblies 407, 409 and the symmetrical placement of the transporter representation members 326-332 with respect to the ternary links 236, 238 establishes relationships between angles of pivotation of the terminal links 306-312 which are used in the steering of the construction machine 30 and these relationships will now be discussed with reference to FIG. 12. As will be clear from the above description of the structure of the linkage assembly 234, a pivotation of the first ternary link 236 in the first direction 288 thereof through a specific angle such as the angle 418 in FIG. 12 results in a pivotation of the second ternary link 238 in the first direction of pivotation 290 thereof by an equal amount. That is, the second ternary link also pivots through an angle equal to the angle 418 as has been indicated in FIG. 12 via the designation of the angle of pivotation of the second ternary link 238, for a pivotation of the first ternary link 236 through the angle 418, by the same reference numeral 418. The effect of these pivotations is to pull the first terminal link 306 and the second terminal link 312 from the reference positions thereof and the symmetry of construction of the linkage subassemblies 407 and 409 requires that the angles through which the terminal links 306 and 312 pivot be identical as has been shown in FIG. 12 by designating such angles by the same reference numeral 420. Similarly, first terminal link 308 and second terminal link 310 are pushed from the reference positions thereof by equal amounts when the ternary links 236, 238 are pivoted in the first directions thereof as has been indicated by the angles designated 422 in FIG. 12. Should the ternary links 236, 238 be pivoted by an angle equal to the angle 418 in the second directions of pivotation thereof, two reversals in the pivotations of the terminal links 306-312 will occur. The terminal links 306 and 312 will in such case be pushed from the reference positions while the terminal links 308 and 310 will be pulled from the reference positions thereof so that the directions of pivotation of the terminal links 306-312 will be reversed. Similarly, the relative magnitudes of the angles through which the first terminal links 306 and 308 and the relative magnitudes of the angles through which the second terminal links 310 and 312 are pivoted is reversed. That is, for pivotations of the ternary links 236, 238 through an angle equal to the angle 418, the terminal links 306 and 312 will be pivoted through angles equal to the angles 422 while the terminal links 308 and 310 will be pivoted through angles equal to the angle 420. (The reversal in magnitudes of the angles of pivotation of the terminal links from the first pattern of pivotations to the second pattern of pivotations follows from the symmetry of the linkage subassemblies 407, 409 about a line connecting the pivotation axes of the ternary links 236, 238 so that the form of second pattern of pivotations of the terminal links 306-312 can be generated from FIG. 12 by reflecting the dashed lines therein through a line connecting the points 424, 426 which represent the pivotation axes of the ternary links 236, 238 on the case 198.)
The relationship between the angles through which the first terminal links 306, 308 are pivoted and the corresponding relationship between angles of pivotation for the second terminal links 310, 312 is selected in a manner which will now be discussed with reference to FIGS. 13 and 14. Initially, it will be noted that the structure of the first linkage subassembly 407 (and of the second linkage subassembly 409) and the placement of the first transporter representation members 326, 328 (and of the second transporter representation members 330, 332) will establish a fixed relationship between relative pivotations of the first terminal links 306, 308 (and of the second terminal links 310, 312) at such times that the ternary links 236, 238 are pivoted while the transporter representation members 326-332 remain in place and relative pivotations of the first transporter representation members 326, 328 (and of the second transporter representation members 330, 332) at such times that the ternary links 236, 238 are pivoted while the terminal links 306-312 remain in the reference positions thereof on the transporter representation members 326-332. That is, a fixed relationship exists between the relative magnitudes of the angles 420, 422 in FIG. 12 and the relative magnitudes of the angles which have been designated 428 and 430 in FIG. 13. (The same symmetry considerations that require the identity of the angles of pivotation of the first terminal link 306 and second terminal link 312 and require the identity of the angles of pivotation of first terminal link 308 and second terminal link 310 in FIG. 12 also require the identity of the angles of pivotation of first transporter representation member 326 and second transporter representation member 332, as represented by the pivotation of arms 410 and 416 of FIG. 13, and the identity of the angles of pivotation of first transporter representation member 328 and second transporter representation member 330, as represented by pivotation of the arms 412 and 414 in FIG. 13 for the case, shown in FIG. 13, wherein the transporter representation members 326-332 rather than the terminal links 306-312 are displaced from the reference positions thereof in response to a pivotation of the ternary links 236, 238.)
The lengths of the link arms of the linkage subassemblies 407, 409 are selected such that the relationship between the angles 428, 430 in FIG. 13 approximates a relationship between angles which will now be defined with reference to FIG. 14. FIG. 14 is a schematic representation of the chassis 32 wherein the chassis 32 is represented by a rectangle, designated 32 in FIG. 14, having vertices located at the pivotation of axes of the transporters 44-50 and designated by the reference numerals 44-50. The sides and ends of the chassis 32 in FIG. 3 correspond generally to the sides and ends of the rectangle 32 in FIG. 14 and the sides and ends of the rectangle 32 in FIG. 14 have been designated by the numerals used for designating the sides and ends of the chassis 32 in FIG. 3. In order to discuss the preferred mode of steering of machine 30, lines corresponding to the reference lines 176-182 for the transporters 44-50, such lines being shown in FIG. 5, have been drawn on the rectangle in FIG. 14 and designated by the reference numerals corresponding to the reference lines 176-182 in FIG. 5. Similarly, the directions of pivotation 184, 186 of the transporter representation members 44-50 have been indicated in FIG. 14 and designated by the reference numerals used therefor in FIG. 5.
As will be clear to those skilled in the art, the chassis 32 can be caused to turn in a circle about a selected turning center disposed to one side of the chassis 32 by pivoting the totality of transporters 44-50 in a pattern which has been shown for the case wherein the turning center, designated 432 in FIG. 14, is disposed on the first side of the chassis 32. For turning the chassis 32 about the center 432, the dashed lines designated 434-440 in FIG. 13, along which the ground engagement members of the transporters 44-50 roll to accomplish the turn, are positioned perpendicularly to lines, designated 442-448 in FIG. 14, which extend from the pivotation axes of the transporters 44-50 and converge at turning center 432. In the preferred practice of the present invention, turning centers for the chassis 32 are selected to shift along a line, 450 in FIG. 14, which longitudinally bisects the rectangle 32 and such selection establishes relationships between the angles through which the transporters 44-50 are pivoted to effect a turn in a circle about a selected turning center. These relationships are embodied in the linkage 234 for steering the machine 30. The selection of the turning center to lie along the line 450 qualitatively requires that transporters on the same side of the chassis 32 be canted through the same angle and that transporters on opposite sides of the chassis be canted by different amounts as has been shown in FIG. 14 wherein the transporters 44 and 46 are pivoted through the angle 454 and transporters 48 and 50 are pivoted through a smaller angle 456 to produce a turning center 432 displaced a selected distance 452 from a line connecting the pivotation axesof the transporters 44 and 46 on the first side 40 of the chassis 32. Quantitatively, the angle 456 is related to the angle 454 via the identity of the angles 456 and 454 to the angles 458 and 460 respectively shown in FIG. 14. Thus, simple trigonometric relationships between the distance 452 and the positioning of the transporters 44-50 on the chassis 32 define the angles 454 and 456 for selected values of the distance 452. These relationships are embodied in the linkage assembly 234 via the symmetries thereof described above and by selecting the lengths of the link arms. Specifically, the length of the link arms are selected such that the relationship between the angles 430 and 428 in FIG. 13 is approximately the same as the relationship between the angles 458 and 460 in FIG. 14. Such approximation can be carried out via well-known graphical techniques and it has been found that for the case wherein the distance between the pivotation axes of transporter 44 and 46 is 10 feet and the distance between the pivotation axes of the transporters 44 and 48 is 76 inches, suitable lengths for the arms 404, 300, 308 and 412 respectively are 2.653 inches, 4.223 inches, 1.500 inches and 1.365 inches when the pivotation axes of the transporter representation members 326-332 are displaced to the side of the line connecting the points 424, 426 in FIG. 13 by a distance of 4.750 inches, when the distance between the centers of the transporters representation members on one of the representation member mounting plates is 7.250 inches, and when the separation between the pivotation axes of the ternary links 236, 238 on the case 198 is 10 inches. With such structure of the linkage assembly 234, the angle 428 will vary from the angle 460 by less than 1.5 degrees for equal values of up to 72 degrees for the angles 458 and 430. In FIG. 14, the value 72 degrees for the angle 458 corresponds to a value of approximately 18.75 inches for the distance 452 with the above described separations of the transporters 44 and 46and of the transporters 44 and 48. The equality of the two angles designated 454 and of the two angles designated 456 in FIG. 14 is embodied in the linkage assembly 234 by the equality of the two angles designated 430 and of the two angles designated 428 respectively in FIG. 13.
Should the turning center for the chassis 32 be shifted to the second side 42 thereof, the relative magnitudes of the pivotation of the transporters on opposite sides of the chassis 32 is reversed. That is, the transporters 48, 50 pivot through greater angles than do the transporters 44, 46 for such a case. This relationship is embodied in the linkage assembly 234 by the mirror symmetry of the linkage subassemblies 407, 409 about a line between the points 424 and 426. In the same manner that a reversal occurs in the relative magnitudes of the angles 420 and 422 in FIG. 12 for first and second patterns of pivotations of the linkage assembly 234, a reversal in the relative magnitudes of the angles of pivotation of the arms 410 and 412 in FIG. 13 occurs when the ternary links 236, 238 are pivoted in the second directions of pivotation thereof rather than in the first directions of pivotation as shown in FIG. 13.
As shown in FIG. 14, the transporters 46 and 50 near the rear end 38 of the chassis 32 are pivoted in the second direction 186 when the transporters 44, 48 are pivoted in the first direction 184 to effect a turn about a turning center, such as the turning center 432, disposed on the first side 40 of the chassis 32. Similarly, for a turn about a turning center disposed on the second side 42 of the chassis 32, the transporters 44, 48 are pivoted in the second direction 186 while the transporters 46, 50 are pivoted in the first direction 184. This relationship, that the transporters 46, 50 near the rear end 38 of the chassis 32 be pivoted in a direction opposed to the direction of pivotation of the transporters 44, 48 near the forward end 36 of the chassis, is embodied in the linkage assembly 234 by connecting the valves 360-366 to the rams 148, 164-168 in accordance with selection rules which will now be described.
Referring again to FIG. 12, it will be noted that a pivotation of the ternary links 236, 238, as represented in FIG. 12 by the link arms 402, 404 (first ternary link 236) and the link arms 406, 408 (second ternary link 238), in the first directions 288, 290 of pivotation thereof from the reference positions thereof so as to establish a first pattern of pivotations of the terminal links 306-312 will pivot one of the first terminal links 306, 308 and one of the second terminal links 310, 312 through greater angles from the reference positions thereof than such pivotation of the ternary links 236, 238 will pivot the other of the first terminal links 306, 308 and the other of the second terminal links 310, 312 from the reference positions thereof. The valves connected to the terminal links pivoted through the greater angles from the reference positions thereof via pivotation of the ternary links 236, 238 in the first directions 288, 290 of pivotation thereof are connected to the rams 148, 164 which, in turn, are connected to the transporters 44, 46 on the first side 40 of the chassis 32. This selection rule has been exemplified in FIGS. 5, 7 and 12. As shown in FIG. 12, a first pattern of pivotation of the terminal links pivots the first terminal link 308 and the second terminal link 310 through greater angles than the first terminal link 306 and the second terminal link 312. As shown in FIG. 7, the terminal links 308 and 310 are mounted on the valves 362 and 364 respectively, and, as shown in FIG. 5, the valves 362 and 364, are connected to rams 148 and 164, respectively, which position transporters 44 and 46 on the first side 40 of the chassis 32. Similarly, as is also shown in FIG. 5, valves 360 and 366, connected to terminal links 306 and 312 (FIG. 7), such terminal links undergoing the greater angle of pivotation in response to pivotations of the ternary links 236, 238 in the second direction 292, 294 of pivotation of the ternary links 236, 238, are connected to rams 166 and 168 respectively, such rams being in turn connected to the transporters 48 and 50 respectively, disposed on the second side 42 of the chassis 32.
The selection of which of the valves 362, 364 is to be connected to the ram 148 and which is to be connected to the ram 164 can be made arbitrarily. That is, the connection of valve 362 to ram 148 in FIG. 5 and the connection of valve 364 to ram 164 is by way of example and not of limitation. Similarly, the connection of valve 360 to ram 166 and of valve 366 to ram 168 is by way of example and not of limitation. However, the connection of a specific valve to a specific ram establishes a series of correspondences which are utilized in a manner that will become clear below. The connection of a specific valve to a specific ram establishes a correspondence between each valve and a specific transporter via the above noted correspondence between the rams and the transporters, That is, the valve corresponding to a specific transporter is the valve connected to the ram which can be utilized to pivot such transporter. Similarly, the terminal link connected to the valve member of a valve corresponding to a specific transporter will be referred to herein as corresponding to such specific transporter and the transporter representation member where is mounted a valve corresponding to a specific transporter will be referred to herein as corresponding to such specific transporter.
As noted above, the sense of hydraulic pressure a valve 360-366 supplies to a ram 148, 164-168 when the valve member thereof is pivoted in a specific direction from the block-center position thereof can be selected by the selection of which of two conduits connected to the ram to conduct hydraulic fluid between the ram and the valve is connected to each of the outlet ports of the valve. In order to provide the construction machine 30 with the mode of steering shown in FIG. 14, a selection rule is utilized in connecting the valves to the rams. Specifically, the valves connected to rams corresponding to transporters 44, 48 near the forward end 36 of the chassis 32, are connected to such rams so as to provide a first sense of hydraulic pressure thereto in response to pivotations of the ternary links 236, 238 in the first directions 288, 290 of pivotation thereof and the valves connected to rams corresponding to transporters 46, 50 near the rear end 38 of the chassis 32 are connected to such rams so as to provide a second sense of hydraulic pressure thereto in response to a pivotation of the ternary links 236, 238 in the first directions 288, 290 of pivotation thereof. Referring once again to FIG. 5, wherein the hydraulic circuit shown therein is drawn to exemplify the selection rule for corresponding the valves 360-366 to the rams 148, 164-168, such hydraulic circuit has also been drawn to exemplify the present selection rule as will now be discussed.
In FIG. 5, the schematic representations of the valves 360-366 have been drawn such that the lower sections of such representations indicate the hydraulic circuit formed by pivoting the ternary links 236, 238 in the first directions 288, 290 of pivotation thereof so as to pivot the valve members of the valves 360-366 from the blocked-center positions thereof and the upper sections indicated the hydraulic circuit resulting from pivoting the ternary links 236, 238 in the second directions 292, 294. As shown in FIG. 5, the pivotation of the ternary links 236, 238 in the first directions 288, 290 extends the piston of ram 164 (to pivot transporter 44 connected to feedback sheave 152 in the first direction 184), retracts the piston of ram 148 (to pivot transporter 46 connected to feedback sheave 122 in the second direction 186), retracts the piston of a ram 166 (to pivot transporter 48 connected to feedback sheave 154 in the first direction 184) and extends the piston of ram 168 (to pivot transporter 50 connected to feedback sheave 156 in the second direction 186). That is, rams 164, 166 connected to transportation 44, 48 near the forward end 36 of the chassis 32 are supplied with a first sense of hydraulic pressure to pivot the transporters 44, 48 in the first direction 184 and rams 148, 168 connected to transporters 46, 50 near the rear end 38 of the chassis 32 are supplied with the second sense of hydraulic pressure to pivot the transporters 46, 50 in the second direction 186. Accordingly, the transporters 44-50 are pivoted in directions required to establish a turning center on the first side 40 of the chassis 32 via a pivotation of the ternary links 236, 238 in the first directions 288, 290 respectively thereof. Similarly, a pivotation of the ternary links 236, 238 in the second directions 292, 294 will provide a second sense of hydraulic pressure to each of the rams 164, 166 connected to the transporters 44, 48 near the forward end 36 of the chassis 32 so as to pivot the transporters 44, 48 in the second direction 186 while supplying a first sense of hydraulic pressure to the rams 148, 168 so as to pivot the transporters 46, 50 near the rear end 38 of the chasses 32 in the first direction 184. That is, a pivotation of the tenary links 236, 238 in the second directions 292, 294 will pivot the transporters 44-50 in the directions required to establish a turning center on the second side of the chassis 32.
As will be clear from the above discussion of FIG. 14, the establishment of a turning center involves the magnitudes of the angles through which the transporters 44-50 are pivoted as well as the directions in which the transporters 44-50 are pivoted. In order to limit the angle through which each transporter 44-50 is pivoted so as to establish a turning center to one side of the chassis 32, the present invention includes a feedback assembly 470, shown in FIG. 15 and FIGS. 5-8, connecting each transporter 44-50 to the corresponding transporter representation member 326-332. In order to facilitate a discussion of the feedback assembly 470, it is useful to first establish a convention for describing the directions of pivotations of the terminal links 306-312 in relation to pivotations of the transporters 44-50 in the directions 184, 186. A first direction of pivotation of a terminal link 306-312 on a transporter representation member 326-332, as such term is used herein, means that direction of pivotation which will cause the valve to which such terminal link is connected to provide a first sense of hydraulic pressure to the ram to which such valve is connected; that is, to cause the transporter corresponding to the terminal link to pivot in the first direction 184 via the requisite extension or retraction of the piston rod of the ram corresponding to such transporter. A second direction of pivotation of a terminal link 306-312 similarly causes a pivotation of the corresponding transporter 44-50 in the second direction 186. For the example of correspondences between the valves 360-366 and the transporters 44-50 shown in FIG. 5, the first direction of pivotation of the terminal links 306-312 have been indicated in FIG. 12 and identified by the common reference numeral 472 and the second directions of pivotation of the terminal links 306-312 have been similarly identified by the common reference numeral 474 in FIG. 12. Corresponding to a first direction 472 of pivotation of a terminal link 306-312 on a transporter representation member 326-332, each transporter representation member 326-332 has a first direction of pivotation 476 and a second direction of pivotation 478 on the case 198 and such directions are shown in FIG. 13 via direction arrows on the arms 410-416 which are disposed along lines between the axes of pivotation of the transporter representation members 326-332 and the shafts on the valve members of the valves 360-362 as previously discussed. As shown in FIGS. 12 and 13, the first direction of pivotation of a transporter representation member 326-332 is the direction wherein the transporter representation member 326-332 is pivoted to return the corresponding terminal link 306-312 to the reference position thereof on such transporter representation member 326-332 where a pivotation of the ternary links 236, 238 has caused such corresponding terminal link 306-312 to pivot in the first direction 472 at such times that the transporter representation members 326-332 have remained in fixed positions. That is, where a pivotation of the ternary links 236, 238 will pivot a specific terminal link from the reference position thereof in the first direction 472, a pivotation of the corresponding transporter representation member in the first direction 476 returns such terminal link to the reference position thereof. The directions 476, 478 of pivotation of the transporter representation member 328 have also been shown in dashed lines in FIG. 6.
The feedback assembly 470 includes the feedback sheaves 122, 152-156 and the construction of the feedback sheaves is shown in FIG. 5 for the feedback sheave 122. The feedback sheave 122 is formed of plate metal in two semicircular portions 480 and 482 which join along a common diameter 484. Notches, 486, 488, formed in the portions 480, 482 respectively along the diameter 484, coact to form a square hole in the center of the feedback sheave 122 to permit the support shaft 132 of transporter 46 to pass through the feedback sheave 122. A groove 490 is formed circumferentially about the outer periphery of the feedback sheave 122 on a radius 492 and such radius is selected to be twice that of the radius 356 of the grooves 353 and 355 in the circumferential peripheries of the transporter representation members 326-332 (FIG. 8) for a purpose which will become clear below. The feedback sheaves 152-156 are constructed in the same manner as the feedback sheave 122.
Referring now to FIG. 15, shown therein are portions of the base beams 194, 196 between the transporters 44-50 as the base beams 194, 196 would be seen from above the chassis 32 with the forward end of the chassis 32 to the left of the drawing. Portions of the feedback assembly 470 are disposed between the base beams 194, 196 and such portions include cables which extend to the transporter pivotation initiating assembly 192 in a manner to be discussed with particular reference to FIG. 6. In order to more clearly show the extension of these cables to the transporter pivotation initiating assembly 192, FIG. 6 has been placed below FIG. 15 and portions of the feedback assembly 470 shown in FIG. 15 have been drawn on an expanded scale, with respect to the forward-to-rear extent of the chassis 32, so as to generally align portions of these cables shown in FIG. 15 with remaining portions thereof shown in FIG. 6.
The feedback assembly 470 comprises four feedback subassemblies 494-500, each of which connects a specific feedback sheave 122, 152-156, connected to a specific transporter 44-50, to the specific transporter representation member 326-332 corresponding to such specific transporter 44-50. Thus, each feedback assembly corresponds to a specific one of the transporters 44-50. The feedback subassemblies 494-500 have common structure so that it will suffice for purposes of the present disclosure to describe one of the feedback subassemblies 494-500 in detail, point out corresponding features of the other feedback subassemblies 494-500 and describe the system whereby the feedback subassemblies 494-500 connect the feedback sheaves 122, 152-156 to the transporter representation members 326-332.
The feedback subassembly 496, which connects the feedback sheave 122 mounted on the transporter 46 to the transporter representation member 328, in correspondence with the transporter 46, comprises a pulley 502 having a sheave mount 504 and a sheave 506 pivotally mounted at one end of the sheave mount 504. A first feedback cable 508 has one end secured to the periphery of the feedback sheave 122 by a suitable clamp (not shown) and portions of the first feedback cable 508 near such end thereof are disposed in the circumferential groove 490 (FIG. 5) formed in the periphery of the feedback sheave 122, such portions of the first feedback cable 508 extending about a portion of the feedback sheave 122. It is convenient to attach the first feedback cable 508 to the feedback sheave 122 such that portions of the first feedback cable 508 extend substantially in a semicircular arc about the support shaft 132 of the transporter 46 at such times that the ground engagement member 140 of the transporter 46 is positioned to roll along reference line 178 and such that the first feedback cable 508 is taken up by the feedback sheave 122 in response to a pivotation of the transporter 46 in the first direction 184 and is paid out therefrom in response to a pivotation of the transporter 46 in the second direction 186. For this purpose, the common diameter 484 of the two portions 480, 482 of the feedback sheave 122 is aligned with the reference line 178 of the transporter 46, with the portion 482 of the feedback sheave 122 adjacent the first base beam 194, when the ground engagement member 140 is positioned to roll along line 178. The end of the first feedback cable 508 attached to the feedback sheave 122 is then attached thereto at substantially the center of the circular portion of the periphery of the semicircular portion 482 of the feedback sheave 122 and extends along rear portions of the feedback sheave 122 to substantially the center of the semicircular portion 480 of the feedback sheave 122. From the feedback sheave 122, the first feedback cable 508 extends over the first base beam 194 to the pulley 502 and is looped about the sheave 506 thereof. The other end of the first feedback cable 507 is then secured to the first base beam 194 by any suitable means. The pulley 502 is aligned with the transporter pivotation initiating assembly 192 in a manner which has been indicated in the relative positioning of FIGS. 15 and 6 and the above described forward-to-rear expansion of the feedback assembly 470, such alignment to be presently discussed, and a sheave 510 is mounted in any suitable manner on the chassis 32 to position intermediate portions of the first feedback cable 508 so as to align the first feedback cable 508 both with the feedback sheave 122 and the pulley 502 for routing the first feedback cable 508 in the manner described.
The feedback subassembly 496 further comprises a sheave 512 mounted on the second base beam 196 and generally aligned with the sheave 510 and the pulley 502. A second feedback cable 514 is secured at one end thereof to the sheave mount 504, via a turnbuckle 516, and the other end of the second feedback cable 514 is attached to one end of a spring 518 which is secured, at the other end thereof, to the second base beam 196. Intermediate portions of the second feedback cable 514 are routed to, and looped about the transporter representation member which corresponds to the transporter 46 whereon the feedback sheave 122 is mounted. (The feedback assembly 470 has been drawn in FIG. 15, and in FIG. 6, so as to be consistent with the correspondences between the transporters, the rams and the valves shown in FIG. 5. For the exemplary connection shown in FIG. 5, the valve 362 is mounted on the transporter representation member 328 so that the feedback subassembly 496, which corresponds to the transporter 46 via the connection of the first feedback cable 504 to the feedback sheave 122, is looped about the transporter representation member 328 which similarly corresponds to the transporter 46).
Referring now to FIG. 6, shown therein is the manner wherein the second feedback cable 514 is looped about the transporter representation member 328. As noted above, portions of cables extending from between the base beams 194, 196, as shown in FIG. 15, to the transporter pivotation initiating assembly 192 are aligned with remaining portions of such cables shown in FIG. 6 and portions of the second feedback cable 514 near the upper portion of FIG. 6 have been designated with the reference numeral 514 to more clearly show such alignment. In order to loop the second feedback cable 514 about the transporter representation member 328, sheaves 520, 522 (FIG. 7) are mounted on the flange 214 at the lower edge of the inner side wall 204 to route the sides of the loop formed by the second feedback cable 514 under the case 198 of the transporter pivotation initiating assembly 192. Sheaves 524, 526 (FIG. 7) are mounted on two of the ribs 218, near the lower ends thereof, on the outer sidewall 206 to route the second feedback cable 514 along the outer sidewall 206. Sheaves 528, 530 (FIG. 6) near the upper ends of the ribs 218 whereon are mounted the sheaves 524, 526 route the second feedback cable 514 through an aperture 525 (FIG. 8) in the outer side wall 206 to the transporter representation member 328 whereon the second feedback cable 514 is looped to extend through a portion of the groove 353 in the outer periphery of the transporter representation member 328 as shown in FIG. 6.
As shown in FIGS. 6 and 7, the ribs 218 whereon the sheaves 524-530 are mounted are aligned with diametrically opposed edges of the transporter representation member 328. The sheaves 520 and 522 on flange 214 are similarly aligned with the transporter representation member 328 and such alignment is used to position those portions of the feedback subassembly 496, shown in FIG. 15, disposed between the base beams 194, 196 of the cahssis 32. The second feedback cable 514 thus has the general form of the letter U folded to extend along three sides of the case 198 of the transporter pivotation initiating assembly 192 with the base of the U extending along the groove 353 and the sheave 520-530 are positioned to maintain such form of the second feedback cable 514. It will be noted that such configuration of the second feedback cable 514, the placement of the transporter representation members 328 and 332 on the case 198, and the placement of the groove 353 in the transporter representation member 328 causes the second feedback cable 514 to pass thrugh the groove 358 in the transporter representation member 332 and the groove 358 is formed for the purpose of preventing interference between the second feedback cable 514 and the transporter representation member 332 while permitting the groove 353 in the transporter representation member 328 and the groove 355 (FIG. 8) in the transporter representation member 332 to have equal diameters.
As will be clear from the above description of the feedback subassembly 496, the spring 518 will provide tension in the feedback cables 508, 514 such that a pivotation of the transporter 46 and, accordingly of the feedback sheave 122, will be accompanied by a pivotation of the transporter representation member 328. (A suitable clamp, not shown, can be mounted on the transporter representation member 328 to engage the second feedback cable 514 and prevent slippage thereof in the groove 353.)
Moreover, the structure of the feedback subassembly 496 and the manner in which the feedback cables 508 and 514 are connected to the feedback sheave 122 and the transporter representation member 328 respectively establish a fixed relationship between the pivotation of the transporter 46 and the pivotation of the transporter representation member 328, both as regards the magnitude of such pivotations and the directions thereof. Referring first to the relative magnitudes of such pivotations, a pivotation of the transporter 46, to pivot the feedback sheave 122, such that the first feedback cable 508 is paid out or taken up by the feedback sheave 122 will result in a shift in position of the pulley 502 by an amount equal to one half of the length of the first feedback cable 508 which is paid out or taken up by the feedback sheave 122. That is, the shift in position of the pulley 502 is one half the product of the radius of the groove 490 in the feedback sheave 122 and the angle of pivotation (in radian measure) of the transporter 46. Thus, a length of the second feedback cable 514 equal to one half the product of the diameter of the groove 490 in the feedback sheave 122 and the angle of pivotation of transporter 46 will roll on transporter representation member 328 to pivot the transporter representation member 328. Since the radius of the groove 353 in transporter representation member 328 is one half the radius of groove 490, the angle of pivotation of transporter representation member 328, found by dividing the shift in position of pulley 502 by the radius of groove 353, is equal to the angle of pivotation of transporter 46. (That is, the result of dividing one half the product of a given radius and a given angle by one half the given radius is the given angle.)
For purpose of relating the direction of pivotation of transporter representation member 328 to the direction of pivotation of the transporter 46, the arm 412 of FIG. 13, between the center of transporter representation member 328 and the valve member of valve 362 mounted on such transporter representation member, and the first and second directions 476, 478 of pivotation of the transporter representation member 328, shown in FIG. 31, have been drawn in dashed lines on the transporter representation member 328 in FIG. 6. With the first feedback cable 508 connected to the feedback sheave 122 as shown in FIG. 15 and as described above, a pivotation of the transporter 46 in the first direction 184 will result in an additional portion of the first feedback cable 508 being taken up by the feedback sheave 122 so as to draw the pulley 502 toward the first base beam 194. The movement of pulley 502 draws portions of the second feedback cable 514 passing over the sheave 528 in FIG. 6 away from the transporter representation member 328 so that transporter representation 328 is pivoted in first direction 476 thereof on the case 198. Thus, the feedback subassembly 496 pivots the transporter representation member 328 in response to a pivotation of the transporter 46 to which the transporter representation member 328 corresponds in accordance with a rule as follows: the angle of the pivotation of the transporter representation member 328 is the same as the angle of the pivotation of the transporter 46 and a pivotation of the transporter 46 in the first direction 184, as first and second directions of pivotation have been defined therefor, results in a pivotation of the transporter representation member 328 in the first direction thereof, as first and second directions of pivotation have been defined for the transporter representation member 328.
As shown in FIGS. 15 and 6, the remaining feedback subassemblies 494, 498, and 500 respectively similarly comprise: pulleys 532-536 respectively having sheaves 538-542 respectively; first feedback cables 544-548 which are attached at one end to base beams 194, 196, and 196 respectively, pass over the sheaves 538-542 respectively, and are routed to and attached to the feedback sheaves 152-156 respectively; and second feedback cables 550-554 respectively, which are attached at one end of each thereof to the pulleys 532-536 respectively and are each attached at the other ends thereof to springs 556-560 respectively. The other ends of the springs 556-560 are each secured to the base beam 196 and intermediate portions of the second feedback cables 550-554 are looped about the transporter representation members 330, 326 and 332 respectively, to pivot the transporter representation members 330, 326, and 332 respectively, in response to pivotations of the transporters 44, 48 and 50 respectively.
The second feedback cable 552 is routed to the transporter representation member 326 in the same manner that the second feedback cable 514 is routed to the transporter representation member 328; that is, via sheaves 562 and 564 (FIG. 7) on the flange 214 and via sheaves 566, 568 (FIG. 7) and sheaves 570, 572 (FIG. 6) on two of the ribs 218 on the outer side wall 206 of the case 198. A variation in such routing is utilized for second feedback cables 550 and 554 to prevent crossing and possible entanglement of portions of different feedback subassemblies 494-500. As shown in FIG. 15, the spring 556 and pulley 532 of feedback subassembly 494 are positioned between the spring 558 and the pulley 534 of feedback subassembly 498 and sheaves 574, 576 (FIG. 7) on the flange 214, sheaves 578, 580 (FIG. 7) and sheaves 582, 584 (FIG. 6) mounted on two of the ribs 218 between the ribs 218 whereon the sheaves 566-572 are mounted, maintain portions of the second feedback cable 550 on opposite sides of the transporter representation member 330 in a parallel arrangement to the top of the outer side wall 206 of the case 198. Sheaves 573 and 575 (FIG. 6) mounted on the flange 216 guide the second feedback cable 550 into the groove (not shown) formed in the periphery of the transporter representation member 330. The spring 560 and pulley 542 of feedback subassembly 500 are similarly disposed between the spring 518 and pulley 502 of feedback subassembly 496 and sheaves 577, 579 (FIG. 7) on flange 214, sheaves 581, 583 (FIG. 7) and sheaves 586, 588 (FIG. 6) on two of the ribs 218 between ribs 218 whereon the sheaves 524-530 are mounted, and sheaves 594, 596 (FIG. 6) on the flange 216 route the second feedback cable 554 to the transporter representation member 332. As in the case of the second feedback cable 514, second feedback cables 550-554 enter the case 198 via the aperture 525 (FIG. 8) formed in the outer side wall 206 of the case 198.
The above described rule for the relative magnitude and direction of a pivotation of the transporter representation member 328 in response to a pivotation of the transporter 46 applies to the transporter representation member 326, 330 and 332. That is, a pivotation of any transporter 44-50 causes a pivotation of equal magnitude of the transporter representation member 326-332 corresponding thereto and a pivotation of a transporter 44-50 in the first direction 184, as directions of pivotation have been defined for the transporters 44-50, causes a pivotation of the transporter representation member 326-332 corresponding thereto in the first direction 476, as directions of pivotation have been defined for the transporter representation members 326-332 above. As will be clear to those skilled in the art, the rule as regards the relative directions of pivotation of transporters 44-50 and transporter representation members 326-332 can be selected by the manner wherein the first feedback cables 508, 544-548 are wrapped on the feedback sheaves 122, 152-156 respectively. As noted above, at such times that the transporter 46 is aligned with the reference direction 178, the first feedback cable 508 is secured to the feedback sheave 122 adjacent the first base beam 194 of the chassis 32 and extends about the rear of the feedback sheave 122. With the routing of the second feedback cable 514 to the transporter representation member 328 as has been described above, such attachment of the first feedback cable 508 results in the relative direction of pivotation rule recited above for the transporter 46 and the transporter representation member 328. Similarly, such relative direction of pivotation rule for the feedback subassemblies 494, 498 and 500 is achieved by the manner wherein the first feedback cables 544, 546 and 548 are attached to the feedback sheaves 152, 154 and 156. Specifically, the first feedback cable 548 is attached to the feedback sheave 156 at a point adjacent the second base beam 196 at such times that the transporter 50 is aligned with the reference direction 182 and the first feedback cable 548 extends about the rear of the feedback sheave 156. In the feedback subassemblies 494 and 498, the first feedback cables 544 and 546 are attached to the feedback sheaves 152 and 154 respectively, at points diametrically opposed to points of the feedback sheaves 152, 154 adjacent the base beams 194, 196 respectively and the first feedback cables 544, 546 extend about forward portions of the feedback sheaves 152 and 154 respectively.
It will be useful at this point to consider the operation of the transporter pivotation initiating assembly 192 and the feedback assembly 470 in steering the construction machine 30 and reference is made to FIGS. 5, 12, 13, and 14 for this purpose. As noted above the drawings exemplify one manner of connecting the components in the present invention and have been drawn so as to be consistent with one another. Accordingly, the following description will be given with regard to the exemplification of the present invention shown in the drawings. Referring first to FIG. 12, a pivotation of the ternary links 236, 238 in the first directions of pivotation thereof will displace the terminal links 306-308 from the reference positions thereof, shown in solid lines in FIG. 12, at such times that the transporters 44-50 are aligned with the reference directions 176-182 so as to position the transporter representation members 326-332 (as represented by the arms 410-416 in FIG. 12) in the reference positions of the transporter representation members 326-332. Specifically, for the exemplification of the present invention shown in the drawings, the terminal links 306 and 310 will be pivoted in the first direction 472 while the terminal links 308 and 312 will be pivoted in the second direction 474. That is, the terminal links 306, 310 will be pivoted such that the valves 360, 364 (FIG. 5) connected thereto will provide a first sense of hydraulic pressure to the rams 164 and 166 and the terminal links 308, 312 will be pivoted such that the valves 362, 366 connected thereto provide a second sense of hydraulic pressure to the hydraulic rams 148 and 168. As noted above, a first sense of hydraulic pressure supplied to a ram will extend or retract the piston rod of the ram so as to pivot the transporter to which such ram corresponds in the first direction 184 while a second sense of hydraulic pressure will extend or retract the piston rod of the ram so as to pivot the transporter to which such ram corresponds in the second direction 186. Accordingly, since valves 360 and 364 are connected to rams 166 and 164 respectively, such rams corresponding to transporters 48, 44 respectively near the forward end 36 of the chassis 32, the transporters 44 and 48 will be pivoted in the first direction 184. Conversely, transporters 46 and 50, near the rear end 38 of the chassis 32, will be pivoted in the second direction 186.
The pivotation of the transporters 44-50 pivots the transporter representation members 326-332 from the reference positions thereof via the connections provided between the transporters 44-50 and the transporter representation members 328-332 by the feedback assembly 470. Specifically, transporter representation members 330 and 326, corresponding to transporters 44 and 48 respectively and represented in FIG. 13 by the arms 414 and 410 respectively, will be pivoted in the first direction 476 by the feedback subassemblies 494 and 498 respectively. Conversely, transporter representation members 328 and 332, represented in FIG. 13 by the arms 412 and 416 respectively, will be pivoted in the second direction 478. As a comparison of FIGS. 12 and 13 shows, pivotations of the arms 414 and 410 in the first direction 476 has the effect of pivoting the terminal links 310 and 306 toward the reference positions thereof on the transporter representation members 330 and 326 respectively and pivotations of the arms 412 and 416 has the effect of pivoting the terminal links 308 and 312 toward the reference positions thereof on the transporter representation members 328 and 332 respectively. Thus, the transporters 44-50 will be pivoted by the rams 148, 164-168 and will pivot the transporter representation members 326-332 corresponding thereto until such time that the arms 410-416, representing the transporter representation members 326-332 respectively, in FIG. 13, reach the positions shown in dashed lines in FIG. 13. For such pivotations of the transporter representation members 326-332, the terminal links 306-312 will be in the reference positions thereof on the transporter representation members 326-332 so that the valve members of the valves 360-366 will be in the blocked-center positions thereof wherein no hydraulic pressure is transmitted to the rams 148, 164-168. Since the angle of pivotation of each transporter representation member 326-330 is equal to the angle of pivotation of the transporter 44-50 to which such transporter representation member 326-332 corresponds, the transporters 44-50 will be pivoted, by a pivotation of the ternary links 236, 238 through the angle 418 in FIGS. 12 and 13, through angles having magnitudes as follows: transporters 44, 46 on the first side 40 of the chassis 32, to which transporter representation members 330 (arm 414 in FIG. 13) and 328 (arm 412 in FIG. 13) respectively correspond will be pivoted through the angle 430; transporters 48, 50, on the second side 42 of the chassis 32, to which transporter representation members 326 (arm 410 in FIG. 13) and 332 (arm 416 in FIG. 13) respectively correspond will be pivoted through the smaller angle 428. As noted above, the relationship between the angles 430 and 428 in FIG. 13 is made to be approximately equal to the relationship between the angles 458 and 460 in FIG. 14 with the result that the transporters 44-50 are positioned such that the lines along which the ground engagement members thereof roll are substantially the lines 434-440 respectively, in FIG. 14. Accordingly, the chassis 32 will turn about the turning center 432 on the first side 40 of the chassis 32. As described above, such turning center is disposed along the line 450 which longitudinally bisects the rectangular array of transporters 44-50 on the chassis 32 and the line 450 has been drawn on FIG. 3. In the preferred embodiment of the present invention, the cutting tool 54 is a rotating drum cutter having an axis defined by the line 450 so that steering of the construction machine 30 sweeps the cutting tool 54 in an arc centered on a turning center such as the turning center 432. As will be clear to those skilled in the art, the inside radius of the arc along which the cutting tool 54 is swept will depend upon the lateral placement of the cutting tool 54 on the chassis 32. As shown in FIG. 3, the cutting tool 54 is preferably placed assymmetrically with respect to the sides 40, 42 of the chassis 32. That is, the cutting tool 54 is generally displaced relative to the central frame 34 toward the first side 40 of the chassis 32, such side of the chassis 32 being the side thereof whereon the operator's cabin 188 is disposed. Such placement of the cutting tool 54 permits the construction machine 30 to be steered in a circle about an obstacle, such as a manhole or the like, having dimensions comparable to obstacles to be found in a work surface such as a roadway. It will be noted that such placement of the cutting tool 54 places the mounting well 90 and accordingly, the transporter 46 inside the cut 56 made by the cutting tool 54. The extent of the cut 56 to encompass the transporter 46 will be referred to hereinbelow.
It will be noted by those skilled in the art that the above mode of steering of the construction machine is not dependent upon the displacement of the axes of pivotation of the valve members of the valves 360-366 from the axes of pivotation of the transporter representation members 326-332 on the case 198 as has been shown in FIG. 11 for the mounting of the valve 360 on the transporter representation member 326. Rather, the valve 360 can be mounted on the bracket 380 so that the axes 350 and 384 coincide and the terminal link 306 can be lengthened accordingly. (Similar modifications can be made with regard to the valves 362-366 and the terminal links 308-312.). The purpose of displacing the axis 384 from the axis 350 can be seen from a comparison of FIGS. 12 and 13. In general, the separation of the axes 350 and 384 results in the angles 422 and 420, through which the terminal links 306-312 are pivoted for a specific angle of pivotation 418 of the ternary links 236, 238 at such times that the transporter representation members 326-332 are in the reference positions thereof, being larger than the angles 430 and 428 through which the transporter representation members 326-332 are pivoted for the pivotation 418 of the ternary links 236, 238, to return the terminal links 306-312 to the reference positions thereof. Thus, the off-center mounting of the valves 360-366 on the transporter representation members 326-332 enhances the steering of the construction machine 30 by effectively reducing the angular extent of the blocked-center positions of the valve members of the valves 360-366 to permit more precise adjustment of the positions of the transporters 44-50 on the chassis 32.
Referring once again to FIGS. 1, 2 and 3, the construction machine 30 includes a shroud 600 which is secured to the underside of the base beams 194, 196 and which extends transversely across the chassis 32 to support the cutting tool 54. The shroud 600 has a central portion 601 having an open first end 602 (FIG. 1) adjacent the first side 40 of the chassis 32 and a similar open second end (not designated in the drawings) adjacent the second side 42 of the chassis 32. A flange 604 is formed on the first end 602 of the central portion 601 of the shroud 600, the flange 604 having the general shape of an inverted letter U, and a groove 606 is formed about the interior portions of the flange 604. An end plate 608 is bolted to the flange 604 and extends across upper portions of the first end 602 of the central portion 601 of the shroud 600 so that the groove 606 and end plate 608 coact to form a channel extending about the first end 602 of the central portion 601 of the shroud 600. (Portions of the end plate 608 have been cut away in FIG. 1 to show the flange 604 and the groove 606.) A first skid plate 610 extends across lower portions of the first end 602 of the central portion 601 of the shroud 600 and portions of the first skid plate 610 extend into the channel formed by the groove 606 and the end plate 608 so that the first skid plate 610 can slide along a substantially vertical line in the channel so formed. A bearing 612 is mounted on the end plate 608 to support one end of a shaft 614 whereon the cutting tool 54 is mounted. (A rectangular aperture 616 is formed in the skid plate 610 to provide clearance between the skid plate 610 and the bearing 612. A cross piece, not shown, extends across the top of the aperture 616 to prevent the skid plate 610 from being dislodged from the shroud 600 should the chassis 32 be raised via the rams disposed along the axes of the transporters 44-50. A portion of the skid plate 610 has been cut away to show the flange 604 and the groove 606.) A forward skid 618 is bolted to the first skid plate 610 near the forward end 620 thereof and a rear skid 622 is bolted to the first skid plate 610 near the rear end 624 thereof. The skids 618, 622 engage uncut portions of the work surface 52 near the first end 72 of the cutting tool 54 so as to locate such uncut portions of the work surface 52 adjacent one side of the cut 56 relative to the chassis 32. An indicator rod mount 626 is bolted to the skid plate 610 with the forward skid 618 for a purpose to be described below.
The central portion 601 of the shroud 600 is closed adjacent the second side 42 of the chassis 32 in the same manner that the end 602 is closed. That is, as shown in FIG. 2, the central portion 601 of the shroud 600 is closed by an end plate 628, similar to the end plate 608, and a vertically slidable second skid plate 630, similar to the skid plate 610. A bearing (not shown) mounted on the end plate 628 supports the end of shaft 614 (not shown in FIG. 2) near the second end 76 of the cutting tool 54 in the same manner that the shaft 614 is supported near the first end 72 of the cutting tool 54. Similarly, the second skid plate 630 is provided with a forward skid 632, a rear skid 634 and an indicator rod mount 636, the indicator rod mount being bolted to the second skid plate 630 with the forward skid 632 in the same manner that the indicator rod mount 626 is bolted to the first skid plate 610 with the skid 618.
The shaft 614 extends laterally of the shroud 600 on the second side 42 of the chassis 32 and a hydraulically driven cutting tool drive assembly 640 is mounted on the end plate 628 to provide a means for rotating the cutting tool 54. The shroud 600 further includes a moldboard assembly 642 having a general V-shape converging toward the rear end 38 of the chassis 32 to deposit asphalt cut from the work surface 52 along selected portions of the cut 56.
The mounting of the cutting tool 54 via the end plates 608, 628 which are rigidly secured to the chassis 32 by means of the central portion 601 of the shroud 600 permits the cutting tool 54 to be positioned with respect to the work surface 52 via positioning the chassis 32 relative to the work surface 52 and, as has been previously noted, the construction machine includes a conventional hydraulic circuit (not shown) for positioning the chassis 32. Such positioning of the chassis 32 can be in response to hydraulic control signals, as is known in the art, and the machine 30 is provided with a hydraulic sensor 644 (FIGS. 1 and 3) on the first side 40 of the chassis 32 near the first end 72 of the cutting tool 54 and a hydraulic sensor 646 (FIGS. 2 and 3) on the second side 42 of the chassis 32 near the second end 76 of the cutting tool 54. The sensors 644, 646, which can be mounted on the chassis 32 in any convenient manner as, for example, the sensor 646 is mounted on the cutting tool drive assembly 640, are of the conventional positionable wand type. That is, the sensors 644, 646 have cases 648, 650 respectively, and wands 652, 654 extending from the cases 648, 650 respectively engage a reference so that the wands provide control signals to cause the chassis 32 to follow such reference. In many applications, the known grade averaging technique, wherein an average grade for the surface whereon work is performed is utilized as a reference, provides a convenient method for controlling the positioning of a machine so as to control cutting operations by the machine on a work surface. The grade averaging assemblies 58, 64 which will now be described, provide the construction machine 30 with the capability of utilizing such grade averaging technique.
Referring to FIG. 3, a bracket 660 having a pair of forwardly projecting, laterally spaced lugs 662, 664 is welded to the forward end 36 of the chassis 32 adjacent the first side 40 thereof. Apertures (not shown) are formed through the lugs 662, 664 to establish a pivotation axis 666, extending laterally along the forward end 36 of the chassis, to provide a means for pivotally mounting the first forward string line support apparatus 60 to the forward end of the chassis 32 as will be described below. A similar bracket 668, having a similarly disposed pair of apertured lugs 670, 672, similarly provides a means for pivotally connecting the second forward stringline support apparatus 66 to the forward end 36 of the chassis 32 for pivotation about a laterally extending axis 674. A bumper 676 is welded to the rear end 38 of the chassis 32 and extends transversely thereacross. Adjacent the first side 40 of the chassis 32, a pair of rearwardly projecting, laterally spaced lugs 678, 680 are welded to the bumper 676 and a similar pair of lugs 682, 684 is welded to the bumper 676 adjacent the second side 42 of the chassis 32. The lugs 678-684 have apertures (not shown) in the manner of the lugs 662, 664, 670, and 672 for pivotally mounting the first rear stringline support apparatus 62 on the rear end 38 of the chassis 32, adjacent the first side 40 thereof, such that the first rear stringline support apparatus 62 will pivot about a laterally extending axis 686 and for pivotally mounting the second rear stringline support apparatus 68 on the rear end 38 of the chassis 32, adjacent the second side 42 thereof, such that the second rear stringline support apparatus 68 will pivot about a laterally extending axis 688. The stringline support apparati 60, 62, 66 and 68 engage the work surface 54 and are positioned thereby about the axes 666, 686, 674, and 688 so that portions of the stringline support apparati 60, 62, 66 and 68, displaced from the axes 666, 686, 674 and 688 respectively, are moved vertically with respect to the chassis 32 by changes in the grade of the work surface 54. A first stringline 689 is connected between such vertically moving portions of the first forward string line support apparatus 60 and the first rear stringline support apparatus 62 and extends along the first side 40 of the chassis 32. The wand 652 of the hydraulic sensor 644 on the first side 40 of the chassis 32 engages medial portions of the first stringline 689 to provide hydraulic control signals to the control circuit (not shown) for positioning the chassis 32 in response to changes in the position of the first stringline 689 in a conventional manner. A second stringline 691 is similarly connected between the second forward stringline support apparatus 64 and the second rear stringline support apparatus 68 and medial portions of the stringline 691 are similarly engaged by the wand 654 of the hydraulic sensor 646 on the second side 42 of the chassis 32 for providing hydraulic control signals to the control circuit (not shown).
The pairs of lugs, 662 and 664, 670 and 672, 678 and 680, and 682 and 684 are equally spaced and each of the stringline support apparati 60, 62, 66 and 68 is constructed in the same manner and connected to the lugs in the same manner. FIG. 16, wherein is shown the second forward stringline support apparatus 66, has been provided to illustrate the common construction of the stringline support assemblies and the common connection thereof to the lugs.
As shown in FIG. 16, the second forward stringline support apparatus 66 has a pivot arm 690 comprising a strap 692 and an arm member 694 welded to one side of the strap 692 near one end thereof, the arm member 694 extending transversely from the strap 692 so as to shape the pivot arm 690 in the general form of the letter L. A pair of lugs 696, 698 are welded to the other side of the strap 692, near the ends of the strap 692, and the lugs 696, 698 are spaced to fit about the lugs 670, 672 on the bracket 668 in an abutting relation with the lugs 670, 672. Apertures (not shown) are formed through the lugs 696, 698 to align with the apertures (not shown) in the lugs 670, 672 and a pin 700, inserted through the apertures in the lugs 670, 672, 696 and 698 is utilized to connect the pivot arm 690 to the lugs 670, 672 for pivotation of the pivot arm 690 about the axis 674. One end of the pin 700 is enlarged and a transverse hole (not shown), accepting a clip (not shown), is formed through the other end of the pin 700 to facilitate removal and connection of the pivot arm 690 from the lugs 670, 672 for a purpose to be described below.
At the distal end 702 of the pivot arm 690, the pivot arm 690 further comprises a tubular member 704 welded to the arm member 694. The tubular member 704 is constructed of square tubing and is connected near one end thereof to the arm member 694 in a parallel relation with the strap 692 so as to be generally parallel to the axis 674 at such times that the second forward stringline support apparatus 66 is mounted on the chassis 32. The tubular member 704 extends from the arm member 694 in the same direction that the strap 692 extends from the arm member 694 and, for a purpose to be described below, has a length approximately half that of the strap 692. A brace 706, connecting the ends of the strap 692 and tubular member 704 opposite the ends thereof welded to the arm member 694, is utilized to form the pivot arm 690 into a rigid structure. The second forward stringline support apparatus further comprises a walking beam support arm 708 constructed of square tubing of a size to telescope within the tubular member 704 and the tubular member 704 is provided with set screws 709, which can be screwed into threaded holes formed in one wall thereof, so that a portion of the walking beam support arm 708 can be inserted into the tubular member 704 and secured thereto via the set screws 709.
The second forward walking beam support arm 708 has two portions 710, 712 which are welded together so as to shape the walking beam support arm 708 into the general form of the letter L. When the second forward stringline support apparatus 66 is assembled on the chassis 32, the portion 710 is disposed in the tubular member 704 with the portion 712 depending therefrom as shown in FIG. 16. A bearing (not shown) is mounted in lower portions of the portion 712 for pivotally mounting a walking beam 714 on the walking beam support arm 708 such that the walking beam 714 extends transversely to the tubular member 704 and pivots about an axis 716 generally parallel to the tubular member 704. That is, the axis 716 is generally parallel to the axis 674. A pin 718 mounted on the walking beam 712 extends into the bearing (not shown) on the portion 712 of the walking beam support arm 708 and is suitably secured therein for mounting the walking beam 714 thereon. Casters 720, 722 mounted on the ends of the walking beam 714 engage the work surface 52 so as to vertically position the distal end 702 of the pivot arm 690 as the machine 30 moves along the work surface 52.
A stringline attachment assembly 724 is mounted on the tubular member 704 for attaching the stringline 691 to the second forward stringline support apparatus 66. The stringline attachment assembly 724 comprises a length of square tubing 726 which is welded to the tubular member 704, opposite the arm member 694, and is disposed transversely to the arm member 694 and the tubular member 704. A T-piece 728, formed of a length of round tubing 730 welded transversely across one end of a length of square tubing 732, sized to telescope in the square tubing 726, is mounted in the square tubing 726 via insertion of the square tubing 732 therein and securing the T-piece 728 to the square tubing 726 via set screws 734 which screw into holes formed in the square tubing 726. A rod 736, having a hook 738 on one end thereof, slides within the round tubing 730 and is secured therein via a set screw 740. The stringline 691 is connected to the hook 738 via a spring 742 which, when the other end of the stringline 691 is connected to a hook (not shown), similar to the hook 738 and mounted on the second rear stringline support apparatus 68, maintains the stringline 691 in a taut condition extending along the second side 42 of the chassis 32.
The stringline support apparati 60, 62 and 68 are constructed in the same manner as the stringline support apparatus 66 so that it will not be necessary to provide a detailed description of the stringline support apparati 60, 62 and 68 for purposes of the present disclosure. Rather, it suffices to note the common construction of the stringline support apparati, 60, 66, 62 and 68 and to designate major components of the stringline support apparati 60, 62 and 68 in FIGS. 1, 2 and 3 with the numerical designations used for such components of the second forward stringline support apparatus 66 in FIG. 16.
The indicator assembly, comprising the indicator subassemblies 70, 74 and 78, shown in FIGS. 1, 2 and 3, provides the operator of the construction machine 30 with a particularly convenient means for manually controlling the position of the chassis 32 with respect to the work surface 52 and for initially positioning the chassis 32 with respect to the work surface 52 for control of the height and attitude of the chassis 32 via one or both of the grade averaging assemblies 58 and 64 and the hydraulic control circuit (not shown). (As will be clear to those skilled in the art, control circuits are available to permit a variety of modes of control of such height and attitude.). The indicator subassemblies 70 and 74 provide direct visual indications of the depth of the cut 56, at each side thereof, so as to provide indirect visual indications of the height of selected portions of the chassis 32 above cut portions of the work surface 52, such indirect indications of height following from the fixing of the cutting tool 54 on the underside of the chassis 32. The indicator subassembly 78 provides an indirect visual indication of the height of the chassis 32 above cut portions of the work surface 52. Specifically, the first indicator sub-assembly 70 provides an indirect visual indication of the height of a first location 752 (FIG. 1), a selected distance above the first end 72 of the cutting tool 54, above cut portions of the work surface 52; the second indicator sub-assembly 74 provides an indirect visual indication of the height of a second location 754 (FIG. 2), a selected distance above the second end 76 of the cutting tool 54, above cut portions of the work surface 52; and the third indicator subassembly 78 provides an indirect visual indication of the height of a third location 756 (FIG. 1), on the cap 96 of the mounting well 90, above cut portions of the work surface 52. The locations 752, 754 and 756 project onto a triangle, shown in phantom lines and designated 750 in FIG. 3 so that the heights of the three locations 752, 754 and 756, will specify the position of the chassis with respect to the work surface 52. The purpose of indicating the heights of the locations 752, 754 and 756 indirectly is for the convenience of the operator of the machine 30 as will be discussed below.
Turning now to FIG. 17, shown therein is the first indicator subassembly 70. The first indicator subassembly 70 comprises a first scale 758, extending substantially vertically on the chassis 32 and having position indicia marked along the length thereof. The position indicia include a reference indicium 760 marked with the numeral "0" and a plurality of auxiliary indicia 762 marked with numerals indicating the distance of each auxiliary indicium from the reference indicium 760. (For clarity of illustration, only one of the auxiliary indicia 762 have been so designated in FIG. 17.) The first scale 758 has a flange 764 on the lower end thereof and the first scale 758 is conveniently mounted on the chassis 32 by screws 766 which secure the first scale 758 to the end plate 608 of the shroud 600. Near the upper end of the first scale 758, an L-shaped rod guide 768 is attached to the side thereof opposite the side bearing the position indicia 760, 762 and the leg of the L extends about one side of the first scale 758 so as to be positioned to one side of the indicia 760, 762. An aperture 770 is formed through the leg of the L. A similar rod guide 772, having a similarly positioned aperture 774, is similarly attached to the first scale 758 near the lower end thereof. A first indicator rod 776 extends through the apertures 770, 774 and is positioned thereby alongside the indicia 760, 762 on the first scale 758. The first indicator rod 776 extends downwardly of the first scale 758 and a bearing 778 is fixed to the lower end thereof. The first indicator rod 776 is bolted, via the bearing 778, to the indicator rod mount 626 which, as noted above, is bolted to the first skid plate 610. Since the first skid plate 610 is supported by uncut portions of the work surface 52 adjacent the side of the cut 56 nearest the first end 72 of the cutting tool 54, the first skid plate 610 provides a means for locating such uncut portions of the work surface 52 for the first indicator sub-assembly 70. A pointer 780 having an aperture 782 formed therethrough to slide on the first indicator rod 776 is mounted on the first indicator rod 776 between the rod guides 768, 772 and portions of the pointer 780 overlay the indicia 760, 762 on the first scale 758. A set screw 784 is utilized to secure the pointer 780 to the first indicator rod 776 in the usual manner so that the pointer 780 can be selectively positioned on the first indicator rod 776 for a purpose to be described below.
The second indicator subassembly 74 (FIG. 2) similarly comprises a second scale 786, a second indicator rod 788, and a second pointer 789 mounted on the second indicator rod 788. The second scale 786 is identical to the first scale 758 and the second indicator rod differs from the first indicator rod 776 only in length. It is convenient for the operator of the construction machine 30 for the location 754 whereat the second scale 786 is disposed to be placed at a greater elevation on the chassis 32 than the location 752 whereat the first scale 758 is disposed on the greater length of the second indicator rod 788 permits the second indicator rod 788 to be connected to the indicator rod mount 636 on the second skid plate 630 in the same manner that the first indicator rod 776 is connected to the indicator rod mount 626 on the first skid plate 610. The scales 758 and 786 are observable by the operator of the machine 30 via a window (not shown) formed near the bottom of the operator's cabin 188 and in the wall thereof facing the forward end 36 of the chassis 32 and via a window 790 (FIG. 2) facing the second side 42 of the chassis 32.
Referring now to FIG. 18, the third indicator subassembly 78 includes a third scale 792 which is mounted on the cap 96 of the mounting well 90 above the aperture 98 formed therethrough. The third scale 792 extends substantially vertically from the cap 96 and has a flange 794 on the lower end thereof which is secured to the cap 96 via screws 796. As shown in FIG. 1, the placement of the third scale 792 on the mounting well 90, positions the third scale 792 behind the operator's cabin 188 and a window (not shown) is provided in the wall of the operator's cabin 188 facing toward the rear end 38 of the chassis 32 to permit the operator of the construction machine 30 to observe the third scale 792. The third scale 792 is oriented to present one side thereof to the operator of the construction machine 30 and position indicia (not shown), identical to the position indicia 760, 762 are marked on such side of the scale 792 presented to the operator of the construction machine 30.
Returning to FIG. 18, rod guides 798 and 800 are attached to the third scale 792, at the top and bottom thereof and on the side thereof facing away from the operator's cabin 188. The rod guides 798, 800 are conveniently formed from strips of sheet metal bent so as to form square loops 802, 804 near one end of the rod guide 798 and the rod guide 800 respectively. The square loops 802, 804 are positioned to one side of the scale 792 so as to slidably position a third indicator rod 806 alongside the third scale 792. The third indicator rod 806 is constructed from square metal rod to mate with the loops 802, 804 and extends from the third scale 792, through the aperture 98 in the cap 96 into the mounting well 90. A right angle bend is formed near the lower end 808 of the third indicator rod 806 and a bearing 810 is fixed on the lower end 808 of the third indicator rod 806 so as to engage the annulus 134 on the support shaft 132 (FIG. 4) of the transporter 46 and roll thereon at such times that the transporter 46 is pivoted to steer the construction machine 30. A pointer 812 is mounted, via a set screw 814, on portions of the third indicator rod 806 between the rod guides 798, 800 and a portion of the pointer 812 (shown in phantom lines in FIG. 18) overlays the position indicia (not shown) on the third scale 792.
The indicator subassemblies 70, 74 and 78 facilitate the positioning of the chassis 32 for both manual and automatic control of the profile of the cut 56 as will now be explained. Prior to any use of the construction machine 30, the construction machine 30 can be driven onto a plane surface and positioned such that the base beams 194, 196 are parallel to such surface and such that the cutting tool 54 will grazingly contact such plane surface. With the construction machine 30 in such position, the pointers on the indicator rods 776, 788 and 806 can be positioned to overlay the reference indicium and can be clamped in such position. Thereafter, the position indicium overlaid by the pointers will specify the position of the chassis with respect to a work surface such as the work surface 52. A particular application wherein such specification is useful would be in situations wherein it is desired that the cut 56 have a rectangular profile and a selected depth for such profile. In such case, the desired profile can be established by positioning the transporters 44-50 axially along the axes of pivotation thereof such that the desired depth of cut is shown directly above the reference indicium on the scales 758 and 786 while the pointer 812 of the third indicating subassembly 76 overlays the reference indicium on the scale 792. Referring to FIG. 1, it will be clear that at such times that the chassis 32 is disposed such that the base beams 194, 196 are parallel to the surface formed by the cut 56 (so that the tool 54 is in grazing contact with the upper surface of the cut 56) the pointer 812 of the third indicator assembly 78 will overlay the reference indicium because the transporter 46 is supported, as noted above, on the surface of the cut 56 and the transporter 46 supports the pointer 812 via the third indicator rod 806. However, the indicator rods 776 and 788 are supported by the skids 618 (FIG. 1) and 636 (FIG. 2) and such skids, engaging portions of the work surface 52 adjacent the cut 56 will be displaced above the surface of the cut 56 by an amount equal to the depth of the cut. Thus, where the chassis 32 is positioned such that the first and second indicator subassemblies 70 and 74 respectively indicate the desired depth of cut while the pointer 812 of the third indicator subassembly 78 overlays the reference indicium on the scale 792, the base beams 194, 196 will parallel the upper surface of the cut 56 and the depth of the cut 56 will be equal to the desired depth.
OPERATION OF THE PREFERRED EMBODIMENT
The machine 30 is suitable for many uses wherein it is desired to form a cut in a work surface and it will be instructive for purposes of describing the operation of the machine 30 to consider an example of a use of the machine 30. It is contemplated that the construction machine 30 will often be used to form a cut in the upper surface of a roadway, such cut having a selected depth and such cut following the grade of the uncut surface. It is further contemplated that the construction machine 30 will often be used in situations wherein the path along which the cut 56 is to be made will not lie along a straight line. For example, in some cases it will be necessary to form a cut about a manhole or the like. Such use is contemplated in the present example. Initially, the construction machine 30 is driven to the location where the cut 56 is to be initiated and the construction machine 30 is positioned to form the cut 56 as the construction machine 30 is driven forwardly. In many cases, automatic control of the profile of the cut 56 will be desirable and one or both of the grade averaging assemblies 58, 64 can be employed to accomplish such control. In such case, smoother portions of the work surface 52 are selected to support the walking beams of one or both of the grade averaging assemblies 58 and 64 to prevent undulations in the cut surface which might otherwise arise from roughness of the uncut surface. For example, in FIG. 16, the walking beam support arm 708 of the stringline support apparatus 66 can be positioned in the tubular member 704 to position the walking beam 714 at a selected distance to the second side of the chassis 32 so that the casters 720, 722 of the walking beam 714 can be supported by relatively smooth portions of the work surface 52 on the second side 40 of the chassis 32. However, should portions of the work surface 52 to the second side of the chassis 32 be severely marred as, by way of example, by the presence of potholes, the walking beam support arm 708 can be removed from the tubular member 704 and reinserted therein such that the walking beam 714 engages portions of the work surface 52 in front of the chassis 32. Again, a range of positions for the walking beam 714 can be selected by positioning the walking beam support arm 708 in the tubular member 704. As will be clear from FIG. 16, where the pivot arm 690 is mounted on the lugs 696 and 698 as shown therein, a dead space in the range of positioning of the walking beam 714 in front of or to the second side of the chassis 32 will exist because of the finite length of the tubular member 704. Such dead space has been eliminated in the present invention by the relative lengths of the tubular member 704 and the strap 692 and by the manner wherein the pivot arms 690 are attached to the chassis 32. As will be clear from the above description of the stringline support apparatus 66, the pivot arm 690 of the stringline support apparatus 66 is easily removed from the lugs 670 and 762 by removal of the pin 700 from the apertures formed through the lugs 670, 672 and the lugs 696, 698. The pivot arm 690 can thus be mounted with the lug 698 engaging the lug 670 and the lug 696 engaging the lug 672 and the pin 700 can then be reinserted. (The T-piece 728 is similarly removed from the tubing 726 and reinserted therein so as to extend above the inverted pivot arm 690.) With such mounting of the pivot arm 690, the arm member 694 is displaced from the second side 42 of the chassis 32 toward the center of the chassis 32 a distance equal to substantially twice the length of the tubular member 704. That is, the tubular member 704 is displaced toward the first side 40 of the construction machine 30 a distance equal to its length. Such displacement of the tubular member 704 permits the positioning of the walking beam 714 within the dead range resulting from the mounting of the pivot arm 690 on the lugs 670 and 672 as shown in FIG. 16. Thus, the walking beam 714 of the stringline support apparatus 66 can be disposed along any line extending forwardly of the chassis 32 within a range extending through approximately one-half the width of the chassis and adjacent the second side 42 thereof. A substantially equal range for positioning of the walking beam 714 is available beyond the second side 42 of the chassis 32. The walking beams of the remaining stringline support apparati 60, 62 and 68 are similarly positionable. Thus, any line extending longitudinally of the chassis 32 can be selected to indicate the grade of the work surface 52 for control purposes so that smoother portions of the work surface 52 can be used for these purposes. In addition, such line can be a composite rather than a single line. Thus, for example, where grade averaging control is to be based on the stringline 691 of the second grade averaging assembly 64 comprised of the stringline support apparati 66 and 68 adjacent the second side 42 of the chassis 32, the walking beam of the second forward stringline support apparatus 66 can be disposed along one line while the walking beam of the second rear stringline support apparatus 68 can be disposed along another line. A particularly advantageous utilization of such capability would be to position the walking beam of the second rear stringline support apparatus within the cut 56 made by the construction machine 30. That is, the construction of the grade averaging assemblies 58 and 64 permits exploitation of the smooth cut made by the construction machine 30 to be utilized in controlling the position of the chassis 32 to continue the cut 56.
Once the walking beams of the grade averaging assemblies 58 and 64 have been positioned on the chassis 32, the chassis 32 is lowered by a manual operation of the hydraulic control circuit which positions the transporters 44-50 along the axes of pivotation thereof such that the pointers of the indicator assemblies 70, 74 and 78 show the desired depth of cut 56. The stringlines 689 and 691 are then positioned, by positioning the T-piece of each of the stringline support apparati 60, 62, 66 and 68, such as the T-piece 728 of the second forward stringline support apparatus 66 shown in FIG. 16, such that the sensors 644 and 646 provide no correction signal to the hydraulic circuit (not shown) which controls the positioning of the chassis 32 relative to the work surface 52. The construction machine 30 is then driven forward over the desired path. It will be noted that after a short distance of travel, the transporter 46 will drop into the cut 56 to lower portions of the chassis 32 near the rear end thereof. However, the walking beam of the first rear stringline support apparatus 62 will, at such time, be supported by uncut portions of the work surface 52. Accordingly, the wand 652 of the sensor 644 will be raised with respect to the chassis 32 to provide a signal to the control circuit to lift the rear end of the chassis 32 by an amount equal to the depth of the cut. With such raising of the rear end 38 of the chassis 32, the pointer 812 of the third indicator subassembly 78 will be lowered with respect to the scale 792 thereof to overlay the reference indicium on the scale 792. The construction machine 30 can then be driven forward under the control of the control circuit so that the cut 56 follows the original grade of the work surface 52.
As has been previously noted, at times it will be desirable that the walking beam of one of the rear stringline support apparati 62, 68 engage portions of the work surface 52 within the cut 56. Where such is the case, the construction machine 30 is driven forward under either manual or automatic control until such walking beams can be disposed within the cut as has been described above. In such operation, the positioning of the stringlines 689, 691 is carried out after a sufficient length of the cut 56 has been formed to permit positioning of the walking beams of the rear stringline support apparati 62 and 68 within the cut 56.
Should an obstacle, such as a manhole or the like be encountered on the path of the cut 56, the operator of the construction machine 30 can position the transporters 44-50, as has been described above, so as to establish a turning center centered on the obstacle. The construction machine 30 can then be driven in an arc about the obstacle and such arc can extend through a complete circle or a portion thereof. Thus, depending upon the application of the construction machine 30, the cut 56 can be formed completely about an obstacle in an initial pass along the work surface 52 or can be formed only partly thereabout in the initial pass and such circular pass about the obstacle can be completed in a subsequent pass. When the construction machine 30 reaches the end of a path whereon the cut 56 is to be formed, the above described guidance system of the construction machine 30 permits the construction machine 30 to be turned on a small radius so that the construction machine 30 can be easily positioned for extraction from locations accessible from only one direction as would be the case, for example, where the work surface 52 is a dead end street.
In many applications, automatic control of the profile of the cut 56 will be unnecessary and the operator of the machine 30 will control the profile of the cut by manual actuation of valves which control rams disposed along the axes of pivotation 80-86 of the transporters 44-50 for raising and lowering the chassis 32 on the transporters 44-50. The first and second indicator subassemblies 70, 74 particularly facilitate such control by providing the operator of the machine 30 with direct visual readings of the depth of the cut 56 at each end of the cutting tool 54. Thus, the operator of the machine 30 can provide corrections to the profile of the cut 56, as needed, by adjusting rams along the axes of transporters on one or the other side of the chassis 32.
It is clear that the present invention is well adapted to carry out the objects and obtain the ends and advantages mentioned as well as those inherent therein. While a presently preferred embodiment of the invention has been described for purposes of the disclosure, numerous changes may be made which will readily suggest themselves to those skilled in the art and which are encompassed in the spirit of the invention disclosed and as defined in the appended claims.
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A wheeled roadway planing machine in which the wheels are pivotable by individual hydraulic rams for steering purposes. Each ram is controlled by a rotary, blocked-center valve and the valves are simulataneously actuated by a linkage which establishes a pattern of off-center displacements of their valve members to initiate pivoting of the wheels. The valves are mounted on pivotable wheel representation members which pivot with the wheels, via cables connecting the representation members to support shafts upon which the wheels are mounted, to return the valves to their blocked-center positions as the wheels pivot to a pattern of positions on the chassis of the machine similar to the pattern of displacements of the valve members resulting from operation of the linkage. A cutting drum is mounted on the chassis to form a cut in the roadway, such cut having a shape determined by the position of the chassis on the support shafts. Such position and the depth of each side of the cut are shown by scales, mounted on the chassis near each end of the drum and near the rear end of the chassis, and pointers mounted on rods positioned by the roadway surface. String lines, extending between supports pivotally attached to the ends of the chassis, provide a grade reference for control of the position of the chassis relative to the roadway. Portions of the supports which engage the roadway are laterally positionable on the chassis for selection of a grade line.
SUMMARY OF THE INVENTION
The present invention relates generally to construction machines and, more particularly, but not by way of limitation, to construction machines having a cutting tool for forming a cut in the surface of a paved work surface as the machine is driven therealong.
In the past it has been common practice to repair blemishes in paved surfaces, such as potholes, cracks and the like in roadways, by the addition of asphalt concrete to the surface. This addition has, in some cases, taken to form of patching the surface and, in other cases, has taken the form of repaving; that is, of overlaying an existing, blemished surface with a new layer of asphalt. It has been found that better results of repair can be achieved, in either case, by preparing the surface for the addition of asphalt by planing away a portion of the surface prior to the addition of new asphalt. A machine for planing such surfaces has been disclosed in U.S. Pat. No. 4,139,318, issued Feb. 13, 1979 to Jakob, et al., and assigned to the assignee of the present invention.
A number of problems are encountered in the use of machines of this type and these problems vary with the circumstances under which machines are used. A very common problem occurs when a machine is used to plane a roadway or the like wherein are located relatively small obstacles, such as manholes, which must be avoided in the planing operation. It is desirable that the machine be large in order that obstacle-free areas can be planed as rapidly as possible and this size has, in the past, resulted in difficulty in the maneuvering of machines about such small obstacles. While linkages, for connecting and turning wheel and track assemblies for turning a machine, are known which will provide various types of machines with a reasonable degree of maneuverability, such linkages are generally unsuited for a planing machine because of the weight and size the planing machine must have to carry out the planing operation. On the other hand, where the machine is guided by servomechanisms, known servomechanisms have not, in the past, been able to provide the machine with the maneuverability required to avoid small obstacles. For example, a known servomechanism includes a master-slave system wherein one track assembly supporting a machine, the master track, is positioned by opening a valve to a ram which turns the master track assembly and providing a means for repositioning the case of the valve to close the valve as the master track assembly reaches a selected position and a similar valve and repositioning means for causing the slave track assembly to follow the master track assembly. While such a servomechanism is capable of steering a heavy machine, such as a planing machine, the turning of track assemblies by equal amounts does not provide a machine with the degree of maneuverability required in many of the applications of a machine used to plane a paved surface.
In the present invention, this problem is solved via a linkage which is connected between representations of the transporters rather than between the transporters themselves. The linkage is utilized to open a plurality of valves mounted on the representation members and a feedback assembly, connecting the transporters to the representations thereof is utilzed to cause the representations to pivot with the transporters to close the valves as the transporters assume desired positions for steering the machine.
It is common in machines of this type to mount the tool used to form a cut in the work surface on the chassis of the machine and to control the position of the tool relative to the work surface by positioning the chassis of the machine relative thereto. Problems arise both in the control of the position of the chassis during a planing operation and in the initial positioning thereof at the commencement of a planing operation. In general, machines of this type are provided with some means for establishing a reference for the chassis with respect to the work surface and a control circuit which senses the position of the reference relative to the chassis of the machine and provides control signals for extablishing the attitude of the chassis from the reference. A common reference is the average grade of an interval of the work surface containing the machine and various types of grade averaging assemblies have been developed to permit such an average grade to be used as a reference. In the past, a problem which has arisen in many cases is that portions of the work surface engaged by a grade averaging assembly have been severely blemished with the result that overcontrol of the chassis of the machine has been affected to leave a cut surface with undesirable undulations. The present invention includes a novel stringline support assembly, attachable to the ends of the construction machine for supporting the ends of a stringline utilized for averaging control, which permits a selection of a wide range of lines, fore and aft of the chassis of the machine, along which the average grade of the work surface is to be measured. For this purpose, the stringline support assembly has a pivot arm which is attached to the end of the chassis and a walking beam which is attached to the pivot arm via a walking beam support arm which is slidable laterally on the pivot arm.
Where control of the attitude of the chassis is accomplished during a planing operation via automatic controls, such controls must be set at the commencement of the planing operation and it is desirable that the controls be set as quickly as is feasible. In the past, it has been found that such setting can be facilited by mounting scales on portions of the chassis adjacent the transporters which move the machine along the work surface and to support pointers by the transporters to indicate the positions of the transporters with respect to the chassis. The pointers are zeroed when the cutting tool grazingly contacts the work surface so that the attitude of the chassis can be established for a desired depth of cut by means of manually raising and lowering the chassis on the transporters while observing the position of the pointers on the scales. While such scales and pointers have been found useful for establishing the position of the chassis of the machine when automatic control of the attitude of the chassis is to be carried out, a problem has arisen where, as is often the case, the attitude of the machine is to be controlled manually. For example, a common type of contract for a planing operation will call for a particular depth of the work surface to be removed. Often, such removal is most conveniently carried out by manually positioning the chassis of the machine during the cutting oeration provided that the position of the cutting tool is known with respect to the work surface. The present invention provides the ease of setting of automatic controls which has heretofore been provided by mounting pointers on the transporters of the machine and further permits for manual control of the attitude of the chassis by utilizing pointers which are positioned by uncut portions of the work surface mounted on the chassis of the machine. By this means, the depth of the cut, at each side thereof, is measured directly and such information is visually displayed to the operator of the machine. A third pointer which is supported by one of the transporters of the machine of the present invention and which rides in the cut made by the cutting tool, overlays a third scale on the chassis of the machine so that the three scales and three pointers can be utilized, at the commencement of a planing operation wherein automatic control of the attitude of the chassis of the machine is to be carried out, to permit rapid positioning of the chassis for setting the automatic controls.
An object of the present invention is to provide a planing machine with a high degree of maneuverability while avoiding the use of heavy linkages between transporters which support the machine on a work surface and move the machine therealong.
Another object of the present invention is to provide a planing machine having the capability of grade averaging control utilizing a selection of lines longitudinal of the chassis of the machine for establishing the control grade.
Yet a further object of the present invention is to provide a planing machine with a scale assembly which permits gauging of the cut made by the machine in a work surface for manual control of the position of the chassis of the machine relative to the work surface, at such times that is desirable to employ manual control, while further permitting the rapid positioning of the chassis of the machine for the setting of devices utilized to automatically control the cut made in the work surface.
Other objects, features and advantages of the present invention will become apparent from the following detailed specification when read in conjunction with the attached drawings and appended claims.
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BACKGROUND OF THE INVENTION
[0001] This invention relates to an electrically actuated vehicle brake that utilizes electromagnets (EMs) to actuate vehicle brake shoes and more particularly to an improved electromagnet construction for such a brake. Such systems must be reliable and have a long life with a response that has low variability of any kind. The EM is attached to one end of a lever that is attached to a backing plate. There is a light spring force between the lever and the EM, thus putting the EM in contact with the face of the brake drum. The EM, when energized, forcibly drags against the face of a rotating brake drum and effects pivotal movement of the lever to actuate the brake shoes. The EM is mounted for limited movement relative to the lever so as to ride flat on the face of the brake drum disk during braking. When an electric current is passed through the coil, the side of the EM housing that faces the face of the brake drum disk is drawn against the rotating brake drum. The lever to which the EM is attached in turn expands the brake shoes into frictional engagement with the brake drum.
[0002] The amount of resultant braking is a function of the amount of electrical current supplied to the EM and the coefficient of friction between the EM and the brake drum disk. As the current increases, the magnetic force of the EM against the brake drum disk creates an increasing frictional drag. The brake shoe actuating arm moves arcuately (within its movement limits) against the arm springs. When the electrical current is decreased, the braking force is lessened. The brake shoe retraction springs operate to retract the brake shoes from engagement with the brake drum and also to return the brake shoe actuating arm to the brake release position. Since electric brakes rely on an electromagnet to convert the electrical energy supplied by a controller to mechanical energy, safety and reliability of the vehicle brakes depend on the low variability and the high repeatability, effectiveness, and reliability of the electromagnet.
[0003] EMs for actuating vehicle brakes have included cast, stamped, and sintered powder metal (PM) EM housings. In general, the EM housings have been cup-shaped and have provided an annular opening to receive a coil winding. Typically, after the coil is positioned within the annular opening, the housing opening is closed with a molding material and it is this visage that develops attractive and frictional drag.
[0004] Most of the currently available magnets in the industry use an epoxy-like material or an injection molding compound to encapsulate the magnet coil in the iron core of the EM and are filled flush to the active frictional face. This material comes in contact with the surface of the brake drum disk. As the material heats, it tends to change its form and can deposit residue on the brake drum. This residue, which is sometimes slippery, cohesive and/or adhesive, tends to cause the brakes to slip, then grab, then slip, and then grab. Some of the material used can also create very low friction and wear (such as in the case of nylon-like material) and can prevent the EM from readily wearing if it stands proud (i.e. prevents the metal from touching). Due to the oftentimes high thermal expansion coefficient and/or high tendency to expand with moisture, this can be a problem as desired frictional drag is uncertain and often greatly reduced. The delayed functional contact of the EM core with the opposing moving metal surface is highly undesirable and dangerous. In both cases the plastic material that is used does not keep the metal-to-metal surfaces from galling and/or does not exhibit the desired frictional drag characteristics.
[0005] Another approach that has been employed is discussed in U.S. Pat. No. 3,668,445 to Grove. Grove uses a frictional insert that is supposed to have a lower wear rate than the PM and is supposed to supply the frictional drag of the unit by way of it standing proud. Grove's explanation is that the primary frictional drag comes not from the metal-to-metal interface but from the insert and the brake drum disk. However, Grove's insert material can carry little force due to its low modulus of elasticity. Thus, approximately 99% of the frictional drag comes from the metal-to-metal contact.
[0006] Grove U.S. Pat. No. 3,760,909 discloses grooves for the purpose or removing surface dust. With the attractive force of the EM in the 200-lb. range and considering the surface speeds, as well as the area of the brake drum disk as compared to the area of the EM, this is not viewed as a primary problem.
[0007] Pressed sintered PM housings have been widely used for electromagnets due to the low cost of manufacturing relative to other methods. Another prime advantage is that very low-carbon high-purity annealed iron can be used that has highly desirable magnetic properties such as having high magnetic saturation capabilities. The disadvantage of the current powdered metal EMs is that they degrade from moisture infiltration. Environmental moisture infiltration can readily occur in powdered metal electromagnets even as they are stored. Moisture infiltration of the powdered metal causes internal corrosion of the powdered metal causing it to have a lower level of magnetic saturation. This reduced magnetic saturation level reduces the drag force that the electromagnet can apply to a drum brake. Degradation of the powdered metal electromagnets due to moisture infiltration has been observed to cause high variability by reducing the drag force of commercially available EMs. As the powder metal corrodes, maximum magnetic saturation level is reduced. The impact can be as high as 65% reduction in the effectiveness of an EM prior to or after being installed in an electric brake. Use of copper infusion, and other like approaches, decreases the allowed magnetic saturation an impractical amount. Use of nonporous coatings cannot exist on the wearing metal-to-metal contact that is required at the EM to drum disk interface. Therefore, moisture can still enter the EM on that surface. Commercially available powdered metal electromagnets that have not yet degraded on the storage shelf can readily degrade in the field upon exposure to moisture. Typically, such EMs in use have had high variability from unit to unit in operating the brake mechanism.
[0008] The current commercially available EMs suffer from premature local magnetic saturation effects within their magnetic circuits that limit the magnetic field that can be produced. This effect is due to variable magnetic cross section in the core structures. The result is that they use more excitation current, larger copper, and more turns to get the magnetic force that is required. The cost of producing such units and the total current for operating a braking system is great. The required power to operate a system using these devices is very high. The wiring installed system excitation wiring resistance for such a system has to be lower due to the higher required operating currents, thus increasing the cost of installation by requiring heavier copper wiring. If smaller copper is used, then the sensitivity of various parts the installation becomes a greater concern in maintaining equal braking responses for the various wheels because of the variations in the excitation circuit for the various axles.
[0009] Some units that are marketed will burn out due to high energy dissipation when on the work bench. When in contact with the brake drum disk, the unit experiences a large protective heat sink; however, when in the process of braking a vehicle, the frictional drag of the EM can produce heat on the order of a thousand watts. Thus the magnetic core heat sink of the coil is at a high temperature that can be on the order of 375 degrees Fahrenheit. The coils and potting of commercial units do not prevent this problem.
SUMMARY OF THE INVENTION
[0010] One aspect of the present invention is an improved electromagnet for use in a brake. the electromagnet comprises a powder metal housing and core, a bobbin, a copper coil, and a friction material. The donor material comprises a powder metal housing and core, a bobbin, a copper coil, and a friction material comprising a polymeric donor material, where the donor material comprises 18% to 35% of a polymer from the group consisting of polyphenylene sulfide, epoxy and phenolic, 5% to 30% Kyanite, 4% to 18% graphite, 9% to 45% of a sulfide or sulfate compound, and 8% to 30% glass fibers, by the total weight of the donor material.
[0011] These and other features, advantages and objects of the present invention will be further understood and appreciated by those skilled in the art by reference to the following specification, claims, and appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] [0012]FIG. 1 is an elevational view of a drum brake assembly employing the present invention;
[0013] [0013]FIG. 2A is a front elevational view of the actuating lever portion of the brake of Fig.
[0014] [0014]FIG. 2B is a side elevational view of the actuating lever of FIG. 2A;
[0015] [0015]FIG. 2C is a perspective view of the actuating lever of FIG. 2A;
[0016] [0016]FIG. 3A is a perspective view of the retaining clip portion of the drum brake assembly of FIG. 1;
[0017] [0017]FIG. 3B is an elevational view of the retaining clip portion of the drum brake assembly of FIG. 1;
[0018] [0018]FIG. 3C is a side elevational view of the retaining clip portion of the drum brake assembly of FIG. 1;
[0019] [0019]FIG. 4 is an exploded perspective view of the electromagnet assembly of the present invention;
[0020] [0020]FIG. 5 is a plan view of the electromagnet assembly of the present invention; and
[0021] [0021]FIG. 6 is a plan view of the surface layers of the electromagnet of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0022] On a vehicle it is essential that all of the wheels have essentially the same braking. Uncertain and unequal electromagnet (EM) response must be avoided to as large an extent as possible to prevent some wheels from having overly aggressive braking response which can lead to lockup that can cause a dangerous loss of control of the vehicle.
[0023] [0023]FIG. 1 illustrates an electric drum brake 100 according to the present invention. Drum brake 100 includes a backing plate 102 , which supports a pair of brake shoes 104 and 106 . The upper portions of brake shoes 104 and 106 engage a post 108 . The lower portion of brake shoes 104 and 106 are positioned by an adjusting link 110 . Tension springs 112 and 114 maintain the relative position of shoes 104 and 106 to post 108 , to adjusting line 110 , and to each other. A pivot pin 116 attached to backing plate 102 supports an actuating lever 118 . The lower end of actuating lever 118 includes a slot (described below), which serves as a means to allow attachment of an electromagnet 120 to actuating lever 118 . Electromagnet 120 is attached to actuating lever 118 by a retaining clip 122 (described below).
[0024] Drum brake 100 operates as follows. Briefly described, when the brakes of a towing vehicle are applied, an electric current is sent to the electromagnet 120 of electric drum brake 100 . The electric current energizes electromagnet 120 . The energized electromagnet 120 is attracted to a brake drum 124 . As electromagnet 120 attempts to rotate with brake drum 124 , actuating lever 118 moves which causes brake shoes 104 and 106 to move radially, thus causing contact and friction between the brake drum and brake shoe.
[0025] [0025]FIGS. 2A, 2B, and 2 C further illustrate actuating lever 118 . Actuating lever 118 is arcuately shaped and has an assembly 133 that accepts pivot pin 116 . Actuating lever 118 also includes a leg 132 at the opposite end from a hole 130 . Leg 132 is sized and shaped to attach to electromagnet 120 .
[0026] FIGS. 3 A- 3 C show the retaining clip 122 in detail. Retaining clip 122 has a first biasing arm 136 , a second biasing arm 138 , a base 140 , and bottom portions 142 and 144 , which depend from biasing arms 136 and 138 , respectively. Biasing arms 136 and 138 are recessent so that retaining clip 122 will snugly hold electromagnet 120 on actuating lever 118 .
[0027] [0027]FIG. 4 illustrates the components of the electromagnet 120 . Included is a housing 150 . Housing 150 includes a channel 152 and a notch 154 in its exterior wall 156 . Housing 150 also has a bore 157 sized and shaped to receive retaining clip 122 . An inner core 158 sits inside housing 150 . Inner core 158 has a bore 160 through it, matching up with bore 157 , and is also sized and shaped to receive retaining clip 122 . Housing 150 and inner core 158 are preferably made of powder metal. Electromagnet 120 also includes a bobbin 162 preferably made of glass-filled nylon, and a coil 164 which is preferably formed of 26-gauge wire having 187 turns. A friction wear material 166 fills the grooves and spaces in the electromagnet 120 . Friction material 166 is described in detail below.
[0028] The rim of the electromagnet of the present invention is preferably between about 0.127 inches and about 0.400 inches, and most preferably about 0.220 inches in thickness. At 0.220 inches, the EM can handle 100 mph conditions of emergency braking. The rim thickness should be formed proportionally to the core width. In other words, as the rim size increases, the core width should increase by the same proportion to balance the propensity of the EM to avoid early limiting magnetic saturation which can cause an enhanced non-linear response.
[0029] PM electromagnets have certain characteristics that make them desirable for automotive brake assemblies and from a magnetic standpoint. They are typically of fully annealed very low carbon (on the order of 0.01%) iron which has a high saturation capability. It is possible to substitute very low cast or rolled fully annealed iron for powdered metal EMs. However, from a wear standpoint, powder metal EMs are superior to such material. It has been found that premature aging of powder metal electromagnets can be eliminated by impregnating the powder metal with a polymeric sealing material. The polymer serves to prevent internal corrosion caused by moisture absorption. As previously stated, moisture infiltration results in corrosion, which reduces the maximum magnetic saturation level capability of the material. Impregnation of the powdered material with the polymer also positively affects the friction and wear characteristics of the EM. The wear between the PM EM surface and the drum brake surface is rather complex due to the free graphite, iron oxides, and grain complexity of a cast iron drum. A typical PM EM is essentially a pure iron structure made up of broadly shaped particles scattered throughout its very porous structure. The pores of the PM EM of the present invention, though impregnated with a sealant, have a propensity to be loaded with the stiffer donor wear products on the exposed contact surface which is highly desirable.
[0030] Impregnating the powdered metal with a polymer aids in the machining of the powdered material because the polymer stabilizes the structure by supporting the particles in shear and reducing the frangible nature of the powdered metal. Thus, impregnation of the powdered metal tends to decrease friability and hence reduces the wear rate of the PM EM.
[0031] Due to the huge surface area of the compressed powder metal particles, it is difficult to protect the powder metal, but impregnation of the EM core assembly is a viable protection of the powder metal to prevent deterioration of the magnetic saturation due to inner magnetic particle oxidation. This is preferable over 100% compaction, which is very costly. Impregnation of the sintered powder metal part allows the performance of the magnet to be a consistent from unit to unit as well as over time.
[0032] Competitor units do not have designs that keep the magnetic cross section throughout the PM Core of the EM. This makes the designs have an inherently poor magnetic performance. Premature saturation takes place in certain areas of the core that limits the desired overall strength and linearity of the magnetic attractive force of the EM. Because of this problem, a constant cross of the EM to within plus or minus three percent is preferable for the present invention.
[0033] The subject cross sections are: the central core, the area below the outside margin of the perimeter of the central core through the thickness of the back body of the cup core, the inside perimeter of the bottom of the rim of the central core through the thickness of the back of the cup core, and the cross section of the body of the rim. The magnetic cross section of the surface of the central core and the surface of the rim is also controlled and held to the highest possible degree in consideration of the need for thermal, magnetic, and donor material supply recovery and redistribution for the frictional drag requirements.
[0034] The approach of the present invention yields a balanced design with better utilization of the material that results in an EM with greater magnetic strength for a given amount of iron and copper. One example is the rim thickness which is increased to prevent saturation of the rim as well as other places that takes place in various commercial electromagnets. This magnetic saturation takes place prior to saturation in other parts of current EMs and is a weak link in current designs. A separate consideration is excessive heating in the rim areas of commercial designs which is due to insufficient cross section, and hence high frictional stress levels and lower thermal conduction. The effect is that there is a greater concentration of thermal energy at this region of the EM. In addition there is a higher thermal gradient due to the small thermal conduction path which increases the temperature thus enhancing the tendency of galling the EM and scoring the brake drum disk. This reduces the service life of both the EM and the brake drum disk. The metal contact areas in the face of the rim of the housing and the face of the inner core have thus been increased in concert with the constant magnetic cross section of the EM. An additional thermal path for the rim is through the higher thermal conductivity of the donor material versus that of the plastic molding compounds used in commercially available EMs.
[0035] It was also found that the lack of mechanical rigidity in the commercial electromagnets caused them to flex and yield so that their mating face flatness to the brake drum disk varied, thus resulting in a changing air gap, causing a change in the attraction force, thereby changing the EM drag force. The current invention corrects this rigidity deficiency by changing the cross sectional area of the core parts which leaves less room for the coil and incorporates more metal in the structural rigidity of the core design. This is in concert with the magnetic constant cross section principal and the use of higher density PM material that has higher yield strength and a higher modulus of elasticity. The yield strength of the PM material is preferably between about 18.5 ksi (kilo psi) and about 50 ksi, and more preferably above 20 ksi. Another preferable method is the selection of a high strength potting material with a high modulus of elasticity, which contributes to the rigidity and strength of the EM.
[0036] A stiff, high thermal conductivity injection molding compound has been invented that also serves as a lossy lubricant that protects the surface of the EM and the brake drum disk from wear yet causes a high coefficient of friction to exist between them. The compound also produces a very thin coating on the ferrous parts that protects by way of increasing the PVF (pressure×velocity×friction coefficient=energy dissipated) capability of the metal contacting surfaces, as well as increasing the friction between them by way of a renewable coating, thus preventing galling and reducing wear. This compound thus serves as a lossy donor lubricant that creates a high coefficient of friction when used with surfaces of PM iron, cast iron or steel, while creating a wear resistant surface on the metal-to-metal contact surfaces. This donor material is used as molding compound that is in the contacting face of the EM, distributed in the annular space between the EM pole pieces, and within the grooves of the metal surfaces of the EM. The grooves thus serve as a source of donor material to accomplish the above purposes prior to and during the engagement of the EM and the brake drum disk surfaces.
[0037] In the preferred embodiment, the powdered metal electromagnets are manufactured out of Hoerganaes 1000 series or 0.45 p Anchor cold rolled steel or their equivalent. This iron is generally made up of 200/325 sieve size particles. The powder metal is green pressed at approximately 30 tons per square inch at approximately room temperature, and then sintered at a temperature of approximately 2050° F. to a density of 6.8 g/cc. Alternatively, the powder metal can be green pressed at 285° F. providing a desired higher density and a higher magnetic saturation capability at an increased cost. Impregnation must take place as soon as possible after sintering.
[0038] The initial DC resistance of a powder metal electromagnet of the present invention is approximately 3.6 ohms. Initially applying 3 amps requires a range of 9.6-10.5 volts to be delivered to the electromagnet terminals at an electromagnet temperature of approximately 75° C. In this voltage range the dissipation is initially 28.8-31.5 W. The external temperature of the electromagnet increases while in use due to electrical current, mechanical friction, and/or temperature of the drum brake. Increasing the temperature of the electromagnet requires constant drive current or an increasing excitation voltage to maintain the same attractive force. The increase in the coil resistance in turn causes an increase in the power dissipation of the electromagnet when driven by a constant current source.
[0039] One method of stabilizing the ampere turns as a function of temperature on a braking system that is voltage controlled is through the use of a series element in each EM that has a negative temperature coefficient of resistance so that when acting in concert with the positive coefficient of the copper wire of the coil, the coil current will remain essentially constant with temperature when excited by a constant voltage. Another method is through the use of a second opposing winding that has a positive temperature coefficient so that the EM has more AT subtracted at low temperature and less subtracted at higher temperature. Thus, in both cases the ampere turns of the EM would be stabilized over temperature. Both methods rely on a brake controller that controls the desired braking by way of establishing a controlling voltage. The system that operates on a controlling voltage principal assures that each wheel of a vehicle receives the same braking. A system that operates on a constant controlling current works well if the current going to each brake EM is the same. Such equal division requires parallel current sources. In each of the above systems an essentially parallel approach is maintained to maximize safety so that loss of one brake does not endanger all.
[0040] The thermal effects can be addressed in part by minimizing the thermal dissipation path. This can be accomplished by minimizing the volume that the windings of the coil need occupy, which in turn minimizes the required cavity volume in the cup core and thus the thermal path. Minimizing the required cup cavity volume allows heat to more quickly dissipate from the electromagnet. Molding the coil with a thermally conductive donor material also decreases the thermal path of the EM. Using the donor material throughout the assembly also allows the EM to operate at a lower drive current to achieve the same frictional drag.
[0041] [0041]FIG. 5 shows the face of the EM 120 with an over-lay of vectors showing motion of the brake drum disk over its face. The frictional drag force between the EM and the ferric brake drum disk face mainly comes from the zone between the metal-to-metal interface. There is a lesser drag force coming from the surface of the non-metal part of the EM and its extended shelf 200 . EM 120 also includes grooves 202 that contain donor material therein. There is a small eddy current drag due to the electrical conductivity of the material of the moving parts.
[0042] The Young's modulus of elasticity of the PM portion of the EM is preferably between about 13 million psi and 29.5 million psi, more preferably between about 17 million psi and about 21 million psi, and most preferably about 19 million psi, compared to 2.5 million psi for the selected non-metal part. This modulus of the magnetic core changes with the density of the PM. The ratio of the areas of the non-metal part and PM faces is approximately 2 to 1 which equates to approximately 10% of the frictional drag being from the surface of the non-metal part. In one unit the non-metal part insert had a modulus approximately 0.125 million psi and if all was the same, the frictional drag contribution of the insert would be 0.5% that of the EM core face. Assuming 100 lb. total drag, the calculated drag from the non-metal part is 10 lb. (due to the modulus being a factor of {fraction (1/10)} that of the PM and the area being double that of the metal). This compares to 0.5 lb. out of a total drag of 60 lb. At 60 mph the eddy current drag is 5 lb. due to the resistivity of cast iron of the inside of brake drum.
[0043] In the case of sliding surfaces between the EM and the brake drum disk, the goal is to minimize wear and yet have a large coefficient of friction. There exist surface-to-surface characteristics and interactions such as electrical contact conduction, heat transfer, frictional electrostatic effects, adhesion, cohesion, mechanical force effects (such as elastic and non-elastic and plastic deformations), mechanical wear, chemical reactivity, absorbed surface layers, and friction, all of which depend on the materials, the surface velocity, the pressure, and temperature.
[0044] There is a large variety of circumstances that exist in the situation of sliding surfaces and hence a large number of theories of lubrication. Commonly, lubrication has a connotation of the reduction of wear and friction. In a broader sense it refers to the control of wear and friction. The frictional phenomenon is in the region of boundary layer lubrication. The measure of success is measured in the value of PVF (in ft.-lb./sec), which is the rate of heat production. The ultimate goal is to control the damaging effects of the energy generation and its mode of dissipation.
[0045] The above non-metal is a donor material that supplies the compounds that make it possible to get high friction, high thermal tolerance with high thermal conductivity, and low wear while having a high elastic modulus. FIG. 6 illustrates one example of how the donor material may be applied through frictional shear and adhesion from the donor surface to the disk and from the disk to the EM interface. The surfaces are likewise supplied material from the donor shelf 200 and the grooves 202 . At the bottom of FIG. 6 is the cast iron drum 222 and at the top, powder metal 220 . FIG. 6 illustrates how it may be to a very large extent controlled, recovered, redistributed, and reused by the multiple transition edges (that have a large dynamic heat mass transfer due to high velocity gradients and hence intense curl at these regions) of the grooves 202 in the face of the EM 120 . The transfer rate tends to be greatest at these places and anywhere there is a rather abrupt change in the point-by-point spacing of the moving surfaces. Grooves 202 serve to recover and distribute the donor material to the EM and brake drum disk contact surfaces. This enhances friction as well as increasing the PVF. Also, the grooved surfaces break up the contact areas so as to better conduct away the heat due to frictional drag, thus preventing a continuing buildup of temperature of the surfaces. Once the surface temperature reaches a certain point, the thermal conductivity starts to significantly decrease and the temperature rises significantly. Once this happens, the local frictional drag increases, thus destroying the original smooth condition of the surfaces.
[0046] The interface must have a sufficiently large overall bearing interface characteristic PVF product capability (Pressure in lb./sq. in)×(relative Velocity in ft./sec.)×(coefficient of Friction experienced), release of heat (in ft.-lb./sec), and thermal conductivity of the assembly to prevent galling and high wear rates. Experimentally it has been shown that the PVF of other commercially available units for the operating conditions of cast iron against the PM in the intended application was too low. Thus there was high wear and galling. In order to extend the magnitude of the PVF product capability of the interface to satisfy the need for the desired performance, special steps and formulation of materials are required. The magnitude of the PVF product is a measure of the performance that a bearing can withstand. At 60 mph the PVF of the EM is in the order of 1,000 watts which is approximately 300 W/sq. in (the EM electrical dissipation at 3 amp is in the order of 35 watts and, a 500-lb. loaded tire brake would be in the order of 36 KW). This must be tolerated without undo alteration of the frictional drag mechanism that is to be protected.
[0047] Certain areas of the EM are made to be a source of the donor material that will supply the materials to create the desired lossy lubricant that will satisfy the required level of PVF. The highest potential PVF is best taken advantage of when the contiguous moving parts are flat and smooth. If they are not flat and smooth, the microscopic and/or macroscopic dissipated heat is uneven and therefore the PVF capacity is not fully utilized. In addition, the thermal conductivity of the thin transfer layers (see FIG. 6) and the nature of the transition layer (free particles) between them and the brake drum disk face all play a roll in the outcome of a moving contact event. The goal is to develop a sufficiently high PVF to cover the basic circumstances as well as its variances so as to support the highest PVF by controlling every link in the chain, the ability to get rid of heat, and to protect the materials. The application is such that the PVF varies with road speed, intensity of desired braking, operating temperature, and the particular surface point on the EM. This latter variable is affected by the geometrical design factors and mounting of the EM on the actuating arm of the brake mechanism.
[0048] The arrows in FIG. 5 indicate the motion of the brake drum disk across the surface of the EM. The surface speed varies as the radius of the path changes, and as the radial area changes, the force changes and hence the stress and the drag force also change. The frictional drag force comes chiefly from the region of the transition layers of the interface between the engaging metal surfaces. The result is that the PVF is different across the face of the EM due to position as well as material. The effect is that the distribution of frictional drag and heat varies. The goal has been to have a high enough PVF characteristic to satisfy the need so that the wear will be minimally affected.
[0049] The design of the EM and the mounting of the EM on the brake activation arm must be such as to cause little torque of the arm from its rest plane to assure free movement of the activation arm. The coupling should be such that the arm is non-binding and free to convey frictional drag force to the activation arm with as little EM overturning moment as possible. Such a moment can cause tilting of the EM which develops uneven surface pressure on the EM face. This must be countered so that the wear on the face of the EM is even. To balance any residual moment, a counter moment is created by including the leading shelf 200 of donor material (see FIG. 5). The shelf 200 is made of an insert of non-magnetic material (so as not to create additional tilting force due to magnetic attraction) that has a low wear rate against the cast iron disk.
[0050] The use of injection molding, use of a thermoset fill, or the use of an insert in the contact face, all of which have special donor characteristics, are used in the assembly of the EM. In all, the binder material has hard particles to clean and hone the surfaces to maximize planar contact area and create friction. Factors for choosing a suitable binder material include its heat deflection temperature, flame retardancy, and a high modulus of elasticity. Suitable binders include polyphenylenesulfide, polyether-ether-ketone, polyether-ketone, polyether-ketone-ether-ketone-ketone, polylmide, polyethernitrile, polyariether-ketone, liquid crystal polymer, epoxy, phenolic, and polyester thermoset.
[0051] Referencing FIG. 6, these hard particles wear less than the main body of the donor material, stand proud, and function to gage the thickness and distribution of the transfer layer 223 . These particles plow the transfer layer 223 and occasionally the pyrite and/or the metals, leaving them clean in small microscopic areas. The plowing also produces high microscopic temperatures when plowing pyrite and metal which can thermochemically reduce a metallic sulfate such as Barite (which includes barium sulfate) or a metallic sulfide such as antimony trisulfide, which is part of the donor. The exposed iron can then be converted into a hard pyrite 224 which is mainly iron sulfide with impurities and is thick at some places and very thin at others. The EM core material is similarly affected except that the metal is relatively soft and malleable pure iron along with a microsurface that can react readily with sulfur and metals. The EM PM surface is full of surface pores and small fissures that can readily retain surface deposits and coatings which offer some special advantages to limit wear yet allow a reasonable coefficient of friction. This takes place through the action of the special donor lubricant.
[0052] Hard particle compositions 225 , graphite, binder particle compositions, iron, along with iron oxides, pyrites, barium with various compounds, and mixtures of the hard particles such as Kyanite pyrites, or aluminum oxide conglomerate mixtures form the transfer films. In this case the clean surfaces promote adhesive coating 226 of the above mixtures made possible by the donor material on the EM and on the cast iron faces. In addition these hard particles 225 of angular crystal-like particles that are imbedded in the surface films as well as in the transfer powder plow the softer interface coatings on the metal surfaces, thus doing work converting mechanical energy to heat. These surfaces are re-finished by cohesive friction of the coatings. Graphite is included to control the degree of cohesive bonding (at 228 for example) of the moving surface coatings and the adhesive bonding of the metal surfaces. Material such as Barite and other materials in the form of relatively small soft somewhat rounded particles serve to better absorb energy of turbulent particles in the layer between the moving surfaces.
[0053] Fiber, such as glass (0.005″ to 0.032″ long×0.0001″ to 0.001″ in diameter, preferably 0.005″ to 0.015″ long×0.0001″ to 0.0005 in diameter), is added to the donor mix to increase shear strength of the donor material of the extended over-hanging shelf, as well as to increase the effective shear strength of the coatings. Another item of importance is the binding material that has characteristics that maintain the renewable surfaces on the cast iron and PM and can withstand the operating temperatures. This combination also works together to form a thin lossy transition lubricant. The donor material preferably includes 18 to 35% PPS, epoxy, or phenolic, 5 to 30% Kyanite or 0 to 20% aluminum oxide, 4 to 18% graphite, 9 to 45% Barite, and 8 to 30% glass fibers by total weight of the donor material. A preferred example donor material has 24% PPS, 19% Kyanite, 41% Barite, 9.5% glass fibers, and 5.7% graphite by total weight of the donor material.
[0054] Due to the fact that the donor material is molded around the EM coil, it was formulated to be an electrical insulator and have a high thermal conductivity. The donor material was also selected to supply a restoration moment. The shelf and the donor material in the slots apply donor material ahead of the surfaces of the metal-to-metal contact of the brake drum disk, thereby supporting the required PVF.
[0055] Torque tests were performed on brakes using the current invention and commercially available brakes. The results from these tests are shown in Tables 1-3. The brakes of Table 1 were tested at 20 mph, the brakes of Table 2 at 40 mph, and the brakes of Table 3 at 60 mph. T 1 , T 2 , T 3 , and T 4 are brakes using the present invention, and C 1 , C 2 , and C 3 are different commercially available electric brake assemblies. “T 1 ” means that the test was aborted due to a safety torque limit so the test fixture would not be destroyed. At 20 mph, the brakes with the present invention had as much as a 42% increase in maximum torque, at 40 mph as much as a 106% increase, and at 60 mph as much as an 82% increase for three-amp excitation compared to the “best” commercial units.
TABLE 1 20 Miles Per Hour Brake Curves for 10 × 2 ¼″ Electric Brake 0 0.5 1 1.5 2 2.5 3 Current in Amps T2 0 700 800 900 1050 1200 1300 Torque: lb-ft T3 0 800 1700 T1 T1 T1 T1 Torque: lb-ft T4 0 500 750 950 1200 1400 1750 Torque: lb-ft T1 0 200 550 725 900 1100 1375 Torque: lb-ft C1 0 200 700 900 1000 1100 1200 Torque: lb-ft C2 0 0 225 425 625 775 925 Torque: lb-ft C3 0 250 600 775 825 1000 1125 Torque: lb-ft
[0056] [0056] TABLE 2 40 Miles Per Hour Brake Curves for 10 × 2 ¼″ Electric Brake 0 0.5 1 1.5 2 2.5 3 Current in Amps T2 0 400 600 800 900 1010 1100 Torque: lb-ft T3 0 400 1000 1200 1400 1700 T1 Torque: lb-ft T4 0 400 750 1000 1200 1350 T1 Torque: lb-ft T1 0 250 600 800 1000 1200 T1 Torque: lb-ft C1 0 100 400 550 650 700 775 Torque: lb-ft C2 0 0 175 350 450 500 600 Torque: lb-ft C3 0 200 475 600 675 750 825 Torque: lb-ft
[0057] [0057] TABLE 3 60 Miles Per Hour Brake Curves for 10 × 2 ¼″ Electric Brake 0 0.5 1 1.5 2 2.5 3 Current in Amps T2 0 300 400 600 700 750 800 Torque: lb-ft T3 0 300 500 575 825 910 1000 Torque: lb-ft T4 0 300 425 625 750 825 900 Torque: lb-ft T1 0 200 425 625 750 825 900 Torque: lb-ft C1 0 100 300 325 400 450 500 Torque: lb-ft C2 0 0 150 175 200 250 300 Torque: lb-ft C3 0 125 300 350 425 425 550 Torque: lb-ft
[0058] These results demonstrate the benefits of brakes made with electromagnets of the present invention. The brakes of the present invention allow the user to create a higher brake torque with less current, therefore creating less heat in the magnet. Also, the larger cross-section of the outer rim allows the PVF to be distributed over a large area which can better conduct away the heat. The heat is also conducted away by the high thermal conductivity of the donor material. These characteristics act in concert to prevent the powder metal from over heating and to prevent galling of the magnet that takes place in the commercial units currently available.
[0059] Wear tests were also performed on two brakes using formulations of the present invention and a commercially available brake assembly. The tests were run at a constant temperature of 200° F. operating at 419 RPM at a constant pressure of against the moving surface of 25 psi. The tests were run for 200 cycles of 20 seconds on, and 10 seconds off. The results of these tests are shown in Table 4. Formula 1 is the commercially available brake friction material, Formula 2 is the result using the present invention, and Formula 3 is the result using the preferred donor material composition of the present invention.
TABLE 4 Material Coefficient of Friction Wear (in inches) Formula 1 0.323 0.108 Formula 2 0.502 0.007 Formula 3 0.556 0.0075
[0060] Formulas 2 and 3 resulted in much higher coefficients of friction and much lower wear as compared to the commercially available brake friction material.
[0061] The above description is considered that of the preferred embodiment only. Modification of the invention will occur to those skilled in the art and to those who make or use the invention. Therefore, it is understood that the embodiment shown in the drawings and described above is merely for illustrative purposes and not intended to limit the scope of the invention, which is defined by the following claims as interpreted according to the principles of patent law, including the doctrine of equivalents.
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A powdered metal electromagnetic is provided that has much less variance between units, increased frictional drag, reduced wear of itself and the brake drum disk during use and an increased resistance to moisture due to the use of a donor material that increases performance and reliability. In addition it can withstand much higher surface speeds while producing higher frictional drag.
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BACKGROUND OF THE INVENTION
[0001] 1. Technical Field
[0002] The present invention relates to lighters. In particular, it relates to lighters that use combustible fuel in which the direction of the flame output is selectively altered by the user.
[0003] 2. Background
[0004] Originally, lighters were designed to project flames vertically. While this may have been an optimum design for cigarettes, it left something to be desired for other uses, such as lighting pipes, cigars, candles, barbeques, etc. A variety of attempts have been made to provide lighters that provide the user with greater control over the direction of the lighter's flame. The development of lighters having a flame which projects at a fixed angle to the side of the lighter has been one attempt to improve the lighter's functionality. A further improvement has been the development of lighters with two flame angles: vertical and/or horizontal. Another development has been lighters that have adjustable flame angles. Lighters that provide adjustable flame angles have a disadvantage in that they have the flame control mechanism that is too close to the flame. In addition, for lighters with extended nozzles, the nozzle or the nozzle extension must be manipulated by hand in order to adjust the flame angle. As a result, safety becomes an issue since they can be difficult to use depending on what is being lit and how it is accessed.
[0005] While these variations of prior art devices accomplish their intended purposes, they also fail to provide a device with a mechanism to retract and/or extend a lighter's flame output, and/or a lighter with an adjustable angle that is safely controlled without requiring the finger(s) of the user to be in close proximity to the flame, output nozzle, or nozzle extension.
SUMMARY OF THE INVENTION
[0006] The present invention provides a lighter with an adjustable flame angle that is controlled by switches or controls that are located at a safe distance from the flame. In one embodiment, a slide mechanism is used in combination with a rotatable flame output that is controlled by operation of a switch or control button that is safely positioned away from the flame output. The control button or switch can be positioned at any suitable location on the lighter. For example, switches or control buttons that may be positioned on different models of the lighters to accommodate left-handed or right-handed users. Optionally, the flame angle can be adjusted along multiple planes of rotation (e.g., up and down, side to side, 360°, etc.).
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a side transparent view of a preferred embodiment of the lighter with the lid in the closed position.
[0008] FIG. 2 is a side transparent view of the preferred embodiment of FIG. 1 with the lid in the open position and the flame ignited and oriented in a vertical direction.
[0009] FIG. 3 is a side transparent view of the preferred embodiment of FIG. 1 with the lid in the open position and the flame ignited and oriented in a side facing direction.
[0010] FIG. 4 is a front perspective view of an alternative preferred embodiment of the lighter showing the flame output and the ignition switch.
[0011] FIG. 5 is a rear perspective view of an alternative preferred embodiment of FIG. 4 showing the flame output, the ignition switch, and the control button.
[0012] FIG. 6A it is a front view of another preferred embodiment of the lighter.
[0013] FIG. 6B is a left side view of the embodiment of FIG. 6A .
[0014] FIG. 6C is a rear view of the embodiment of FIG. 6A .
[0015] FIG. 6D is a right side view of the embodiment of FIG. 6A .
[0016] FIG. 6E is a top view of the embodiment of FIG. 6A .
[0017] FIG. 6F is a bottom view of the embodiment of FIG. 6A
[0018] FIG. 6G Is a perspective view of the embodiment of FIG. 6A .
[0019] FIG. 7A it is a rear view of yet another preferred embodiment of the lighter.
[0020] FIG. 7B is a left side view of the embodiment of FIG. 7A .
[0021] FIG. 7C is a front view of the embodiment of FIG. 7A .
[0022] FIG. 7D is a right side view of the embodiment of FIG. 7A .
[0023] FIG. 7E is a top view of the embodiment of FIG. 7A .
[0024] FIG. 7F is a bottom view of the embodiment of FIG. 7A
[0025] FIG. 7G is a perspective view of the embodiment of FIG. 7A .
[0026] FIG. 8A it is a front view of a further preferred embodiment of the lighter.
[0027] FIG. 8B is a left side view of the embodiment of FIG. 8A .
[0028] FIG. 8C is a rear view of the embodiment of FIG. 8A .
[0029] FIG. 8D is a right side view of the embodiment of FIG. 8A .
[0030] FIG. 8E is a top view of the embodiment of FIG. 8A .
[0031] FIG. 8F is a bottom view of the embodiment of FIG. 8A
[0032] FIG. 8G is a perspective view of the embodiment of FIG. 8A .
[0033] FIG. 9A is a side view of the internal mechanism that adjusts the angle of the flame output.
[0034] FIG. 9B is a front view of the internal mechanism that adjusts the angle of the flame output.
[0035] FIG. 9C is a bottom perspective view of the internal mechanism that adjusts the angle of the flame output.
[0036] FIG. 10A is a side view of an extended multi-segment flame output that adjusts the angle of the flame.
[0037] FIG. 10B is a side view of the extended multi-segment flame output that adjusts the angle of the flame output.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0038] Prior to a detailed discussion of the figures, a general overview of the invention will be presented. The invention provides a lighter 1 with a mechanism that allows the direction of the flame output to be redirected under control of the user. In one preferred embodiment, the mechanism allows a lighter to be ignited in the conventional manner, and after ignition of the lighter 1 , it can be redirected by the user from a thumb slide switch 6 that is remote from the flame output to protect the user from inadvertently burning a finger.
[0039] The preferred embodiment was designed with the intention of producing a product with the minimum number of parts. By minimizing the complexity of the device, the production costs will be reduced and superior reliability will be created due to the simplicity of design.
[0040] Those skilled in the art will recognize that components of the lighter 1 can be fabricated from any suitable material, from low-cost plastics, synthetic materials glass, crystal, wood, metal, precious metal, etc. The only requirement is that the material used to fabricate the device can be safely used as a component of a lighter. Likewise, the materials used for the internal components can be anything suitable for the purpose of the device.
[0041] In the embodiment provided to illustrate the features of the invention, the lighter operates in a similar manner to conventional cigarette lighters. The fuel can be anything suitable, such as gas or liquid fuel.
[0042] Having discussed the features and advantages of the invention in general, we turn now to a more detailed discussion of the figures.
[0043] In FIG. 1 , a preferred embodiment of the lighter 1 is shown. This figure is a transparent side view of the lighter 1 that illustrates the components. The lighter 1 has an external case 2 and an external lid 13 that is attached to the external case 2 by a hinge 14 . Also shown are frictional thumbwheel 12 and flint 11 both of which represent conventional ignition mechanisms found in many lighters. Those skilled in the art will recognize that any suitable ignition mechanism can be used. For example, the mechanical spark igniter illustrated in this figure can be replaced with an electronic spark generator, or any other suitable mechanism.
[0044] The lid 13 shown in FIGS. 1-3 is exemplary of lids commonly used for cigarette lighters. However, those skilled in the art will recognize that the lid 13 is not part of the invention, and depending on the design of the lighter 1 , it can be dispensed with entirely.
[0045] Also shown in this figure is fuel supply 3 . Fuel supply 3 can contain any suitable fuel, such as butane, propane, liquid lighter fuel, etc. Fuel is supplied from the fuel supply 3 to the flame output 8 via a fuel conduit 4 . In the preferred embodiment, the fuel conduit 4 is routed through a hollow portion of the slide mechanism 5 . Fuel output 8 is hingedly attached to slide mechanism 5 via hinge 9 .
[0046] In this figure, the fuel output 8 is fully retracted. Also shown in this figure are thumb slide switch 6 , which is used to slide mechanism 5 up and down, and cam 7 .
[0047] As can be seen from the figure, the flame output 8 is held in a substantially vertical position by cam 7 .
[0048] FIG. 2 illustrates the embodiment of FIG. 1 with the lighter ignited and the flame 15 projecting upward from flame output 8 . In this configuration, the lighter 1 would operate in an identical manner to prior art lighters.
[0049] FIG. 3 illustrates how the direction of flame 15 is user controlled. As the slide mechanism 5 is moved under control of the thumb slide switch 6 , the spring mechanism 10 maintains pressure against the flame output 8 such that it rotates against cam 7 . The user controls the angle of flame 15 with thumb slide switch 6 . As a result, the user can adjust the angle of the flame 15 without having their fingers in close proximity to the flame output 8 . As can be seen, the thumb slide switch 6 is safely located far from the flame output 8 . Likewise, the flame angle can continuously vary under user control.
[0050] This embodiment has the advantage of using a minimal number of parts that reduces costs and reduces the possibility of failure due to the low part count. However, those skilled in the art will recognize that a variety of mechanical alternatives can be used in place of the mechanical slide 5 . For example, the cam 7 used in the embodiment of FIGS. 1-3 can be replaced with a gear assembly that can be operated by a rotatable thumbwheel in place of thumb slide switch 6 . Likewise, thumb slide switch 6 can be replaced with an electronic switch that drives a gear assembly. The gear assembly can also be controlled by electromagnets that are activated by an electronic switch that cause magnets attached to the gear assembly to move in response to the electromagnets, thereby causing the flame output 8 to rotate.
[0051] FIG. 4 is a front perspective view of an alternative preferred embodiment of the lighter 1 showing the flame output 8 and the ignition switch 16 . This embodiment uses a conventional ignition mechanism that is activated by the ignition switch 16 . Typically, these are piezoelectric devices that are well known in the art. A significant advantage of piezoelectric ignitions over older flint ignitions is that flint is eliminated and the reliability of the lighter 10 is improved.
[0052] FIG. 5 is a rear perspective view of the alternative preferred embodiment of FIG. 4 showing the flame output 8 , the ignition switch 16 , and the thumb slide switch 6 . Thumb slide switch 6 is operatively connected to flame output 8 such that when thumb slide switch 6 slides along slot 17 , under control of the user, the flame output 8 rotates to a different angle. Those skilled in the art will recognize that the lighter 1 can be configured such that the flame output 8 can be rotated to any angle, or configured to stop at predetermined angles. Likewise, the angle of flame output 8 can be adjusted before or after ignition since the ignition switch 16 is separate from thumb slide switch 6 .
[0053] An important safety advantage of the invention is that the angle of the flame output 8 can be adjusted remotely, due to the location of thumb slide switch 6 that prevents inadvertent injuries from contact with the flame output 8 . In this figure, thumb slide switch 6 is positioned such that the user controls the flame angle with the user's thumb. However, those skilled in the art will recognize that thumb slide switch 6 can be placed at any convenient location.
[0054] FIG. 6A it is a front view of another preferred embodiment of the lighter 1 . In this figure, the external case 2 , the flame output 8 , the fuel adjuster 19 , and the optional LED lights 20 are shown. The fuel adjuster 19 is a multi-position switch that allows the user to adjust flame height.
[0055] Also shown are the optional LED lights 20 , which provide a flashlight capability that is conveniently available in the lighter that is carried by the user. In the present invention, the LED lights 20 are positioned on the front of lighter 1 to improve ease of use. Those skilled in the art will recognize that when the optional LED lights 20 are present, the user has the advantage of a conveniently available light. However, in embodiments where the optional LED lights 20 are not present, there will be more space available for more fuel storage because the LED battery and LED electronics will not be present. For ease of discussion, three LED lights 20 are shown in this figure. While only one LED light 20 is necessary for this feature, any suitable number of LED lights 20 may be selected based on design choices.
[0056] FIG. 6B is a left side view of the embodiment of FIG. 6A . In this figure, the thumb slide switch 6 is used to rotate the flame output 8 such that the flame direction is user controlled. Ignition switch 16 is also shown. In practice, ignition switch 16 can be activated before or after the direction of flame output 8 is adjusted by thumb slide switch 6 , or simultaneously with adjustment of the flame output. Thumb slide switch 6 changes the direction of the flame output 8 to a plurality of positions. The thumb slide switch 6 can be designed to stop at fixed points. For example, it could be designed such that the flame output 8 stops at 0°, 45°, or 90°. Alternatively, it can be designed such that it can be freely moved to any position from approximately 0° to 360°. Those skilled in the art will recognize that any suitable method for changing the angle of the flame output 8 can be used, including push rods, levers, pulleys, springs, magnets, gears, etc. Those skilled in the art will also recognize that a locking switch (not shown) can be used to allow the flame to remain on for extended periods of time once ignited. The thumb slide switch 6 in the embodiments shown herein is positioned at the rear side of the lighter 1 . However, those skilled in the art will recognize that the thumb slide switch 6 can be positioned at any convenient location on the lighter 1 .
[0057] FIG. 6C is a rear view of the embodiment of FIG. 6A . This figure, the thumb slide switch 6 is shown along with the ignition switch 16 , and the flame output 8 . In addition, the LED activation switch 27 is shown on the rear of the lighter 1 . Those skilled in the art will recognize that activation switch 27 can take the form of a button, a switch, or any other suitable device. Likewise, it can be located at any suitable location on the lighter 1 .
[0058] FIG. 6D is a right side view of the embodiment of FIG. 6A . FIG. 6E is a top view of the embodiment of FIG. 6A . In this view, the gas output port 22 is illustrated along with igniter 21 . When the lighter 1 is activated, gas output port 22 is opened and gas is released. Simultaneously, igniter 21 is activated to initiate the flame. FIG. 6F is a bottom view of the embodiment of FIG. 6A . This view further illustrates gas input port 23 , which is used to refill the lighter 1 . Also shown is battery cover 24 , which secures a battery (not shown) that powers the LED lights 20 , and depending on the ignition method selected, will also power the igniter 21 . FIG. 6G Is a perspective view of the embodiment of FIG. 6A . This illustrates the lighter 1 output 8 in the vertical position.
[0059] FIG. 7A it is a rear view of yet another preferred embodiment of the lighter 1 . This figure illustrates an alternative embodiment in which an alternative flame output 25 rotates under control of thumb slide switch 6 . This embodiment preferably uses a piezoelectric ignition, but suitable alternatives can be used. In this embodiment, the lighter 1 can be designed with a one-step or two-step operation. In the one-step operation, the user pushes the thumb slide switch 6 in to ignite the lighter 1 and simultaneously slides the thumb slide switch down to rotate the flame output 25 . In the two-step operation, the ignition and rotation of the flame output 25 are executed separately. Alternatively, the user can push to ignite the lighter 1 and then slide the slide switch 6 to change the angle or vice-versa. An advantage of the invention is that the user only needs to use one hand to ignite the lighter 1 and to rotate the flame output 25 . As a result, the user is less likely to inadvertently be burned.
[0060] FIG. 7B is a left side view of the embodiment of FIG. 7A . In this figure, the thumb slide switch 6 is used to rotate the flame output 25 such that the flame direction is user controlled. As was the case above, the thumb slide switch 6 changes the direction of the flame output 25 to a plurality of positions such that the flame direction is user controlled. Likewise, the thumb slide switch 6 can be designed to stop at fixed points. For example, it could be designed such that the flame output 25 stops at a variety of predetermined angles. For example, the lighter can be set to any desired angle. By way of example, it could be set to 0°, 45°, or 90°. Further, any suitable angle can be chosen to suit the purposes of a particular lighter. For example, the best angles for use with a cigar may be different than the best angles for use with a pipe, a candle, etc. Alternatively, it can be designed such that it can be freely moved to any position from approximately 0° to 90°. Those skilled in the art will recognize that any suitable method for changing the angle of the flame output 8 can be used, including push rods, levers, pulleys, springs, magnets, gears, etc. Those skilled in the art will also recognize that a locking switch (not shown) can be used to allow the flame to remain on for extended periods of time once ignited.
[0061] FIG. 7C is a front view of the embodiment of FIG. 7A . This figure, flame output 25 is shown. FIG. 7D is a right side view of the embodiment of FIG. 6A . In this figure, flame output 25 is illustrated along with thumb slide switch 6 . FIG. 7E is a top view of the embodiment of FIG. 7A . In this figure, flame output 25 is illustrated. FIG. 7F is a bottom view of the embodiment of FIG. 7A . This view also illustrates flame output 25 . FIG. 7G Is a perspective view of the embodiment of FIG. 7A . This illustrates the flame output 25 in the vertical position.
[0062] FIG. 8A it is a front view of yet another preferred embodiment of the lighter 1 . This embodiment provides a transparent window 26 that allows the user to see the fuel chamber such that the user can determine when the fuel is running low. FIG. 8B is a left side view of the embodiment of FIG. 8A . FIG. 8C is a rear view of the embodiment of FIG. 8A . FIG. 8D is a right side view of the embodiment of FIG. 8A . FIG. 8E is a top view of the embodiment of FIG. 8A . FIG. 8F is a bottom view of the embodiment of FIG. 8A . FIG. 8G is a perspective view of the embodiment of FIG. 8A . The embodiment represented by FIGS. 8A-8G is similar to the embodiment of FIGS. 6A-6G . The difference in the present embodiment is that a transparent window 26 is provided which allows the user to see the internal fuel chamber.
[0063] FIG. 9A is a side view of the internal mechanism that adjusts the angle of the flame output 8 . Thumb slide switch 6 is connected to arm 28 that is in turn connected to loop 29 . When thumb slide switch 28 is moved upward or downward, arm 28 forces loop 29 upward or downward. Loop 29 is slidably attached to posts 31 (shown in FIG. 9C ). As loops 29 are moved vertically, posts 31 slide within loops 29 and force flame output 8 to rotate about pivot 30 . As the flame output 8 rotates on the pivot 30 , the flame angle is selectively adjusted by the user. FIG. 9B is a front view of the internal mechanism that adjusts the angle of the flame output 8 . This figure further illustrates the arms 28 that drive loops 29 . FIG. 9C is a bottom perspective view of the internal mechanism that adjusts the angle of the flame output 8 . This view better illustrates the posts 31 that slide within loops 29 .
[0064] FIG. 10A is a side view of an extended multi-segment flame output 8 that adjusts the angle of the flame. In this embodiment the flame output 8 has extension segments 32 that rotate on knuckles 33 . The advantage of this embodiment is that it allows the lighter 1 to be used in applications where the object of the lighter's flame is difficult to reach (e.g. candles, barbeques, etc). Those skilled in the art will recognize that the number of segments 32 , as well as their length, can vary. Those skilled in the art will recognize that existing finger designs from known robot hands can be used to control movement of the extended multi-segment flame output 8 . As was the case with other embodiments, the lighter 1 can be ignited before, after, or while the segments 32 are being moved.
[0065] FIG. 10B is a side view of the extended multi-segment flame output 8 that adjusts the angle of the flame. This figure shows the extended multi-segment flame output 8 disconnected from the lighter 1 . The control wire 34 extends through the extended multi-segment flame output 8 and connects to the knuckles 33 such that the angle of the flame output can be controlled in the same manner as the other embodiments. For ease of illustration, the gas supply line and ignition line have been omitted.
[0066] While the invention has been described with respect to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in detail may be made therein without departing from the spirit, scope, and teaching of the invention. For example, the material used to construct the lighter and its internal mechanisms may be anything suitable for its purpose, the size and shape of a lighter can vary, the mechanical controls can vary, etc. Accordingly, the invention herein disclosed is to be limited only as specified in the following claims.
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An adjustable lighter in which the flame angle is controlled by a switch located on the lighter a safe distance from the flame. In one embodiment, a thumb slide switch is used to rotate the flame output to one or more flame angles. An alternative embodiment uses a flame output in the form of in the form of a wheel. An optional features include an integral LED lamp, and/or a transparent window that allows the user to view the inside of the lighter.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is being filed simultaneously with the U.S. patent application Ser. No. 773,397 disclosing common subject matter entitled "CASING HANGER LOCKING DEVICE", inventor William David Wightman.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates in general to subsea wellhead equipment, and in particular to a casing or tubing hanger having a metal-to-metal seal.
2. Description of the Prior Art
A typical subsea wellhead assembly includes a wellhead housing mounted within a permanent guide base that is supported on the ocean floor by a temporary guide base. Large diameter conductor pipe is secured to the wellhead housing and extends downward into the earth a short distance. A wellhead is mounted inside the wellhead housing and to a permanent guide base which mounts on the top of the temporary guide base. Surface casing secured to the wellhead extends a few hundred feet down into the well. The top of the wellhead is connected to pressure equipment and risers that extend to a drilling vessel at the surface. As the well is drilled deeper, a first string of casing may be set to a certain depth. Subsequently, a second string of casing may be set.
In a typical installation, the casing hanger includes a casing hanger body which is secured to the upper end of the casing string. The body is supported on an annular shoulder in the wellhead. A seal and a locking means are located in annular clearances between the casing hanger body and wellhead bore. The seal normally includes an elastomeric ring which is compressed by compression rings between the casing hanger body and the wellhead bore. The locking means includes a split ring and/or various wedges, which are normally actuated by rotation of a running tool to lock the elastomeric seal in compression and to lock the casing hanger in the wellhead. Wickers, which are small parallel grooves, may be located in the wellhead bore for engagement by the split ring or wedges. The locking means provides support for the casing hanger.
While successful, elastomeric seals may not have as long of a life as a metal-to-metal seal, particularly if subjected to heat. Metal seals, and combinations of metal and rubber seals, are commercially available for casing hangers. Improvements, however, are desirable.
SUMMARY OF THE INVENTION
The metal seal ring of this invention has inner and outer walls radially separated by annular cavity. An energizing ring is movable into a lower engaged position in the cavity. In this lower position, the energizing ring pushes the walls outward, causing them to seal tightly against the casing hanger body and the wellhead to form a seal. The inner and outer walls each have a seal section which contacts either the hanger or the wellhead to form the seal. A gripping section is located on each wall above the seal section. The gripping section contains a plurality of vertical slots to facilitate expansion of the walls outward. The seal section contains circumferential grooves to concentrate the sealing forces.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial vertical sectional view of a wellhead having a seal constructed in accordance with this invention, and also is showing a locking means for locking the casing hanger in place.
FIG. 2 is an enlarged sectional view of the seal of FIG. 1, shown in the disengaged position.
FIG. 3 is a top partial view of the seal ring for the seal of FIG. 1.
FIG. 4 is a side view of a seal ring shown in FIG. 3.
FIG. 5 is an enlarged vertical sectional view of the locking and supporting means for the casing hanger of FIG. 1, shown in a storage position prior to locking engagement.
FIG. 6 is a further enlarged vertical sectional view of one of the washers of the locking and supporting means, shown in a set position.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The subsea well assembly shown in Fig. 1 includes a wellhead 11. Wellhead 11 is a tubular member located at the sea floor at the top of the well. Wellhead 11 has a bore 13 that contains an upwardly facing landing shoulder 15. Landing shoulder 15 is inclined downwardly. A plurality of locking grooves 17 are located a short distance above the landing shoulder 15 in the bore 13. The locking grooves 17 are approximately 1/4 inch deep in the preferred embodiment, and the centers of each groove are about one inch apart. Locking grooves 17 are circumferential, parallel to each other and have rounded edges.
A plurality of wickers 19 are located in a set spaced above the locking grooves 17. The wickers 19 are much smaller grooves. They are parallel, circular, and formed perpendicular to the axis of bore 13. Preferably there are about eight grooves of wickers 19 per inch. Wickers 19 are generally triangular in cross-section.
A casing hanger 21 is secured to a string of casing (not shown) and lowered into a landing position in the wellhead 11. Often there will be more than one casing hanger 21, each secured to a string of casing of smaller diameter than the casing supported by the casing hanger immediately below. Casing hanger 21 has a body 23 that has an axial bore or passage 25. Body 23 is a tubular member with an outer diameter smaller in diameter than the wellhead bore 13, except for an annular band 27 located intermediate the ends of casing hanger 21. Band 27 closely fits within the bore 13. This results in an upper annular clearance 29 above band 27 and between the casing hanger body 23 and wellhead 11, and a lower annular clearance 31 located below annular band 27. A lock assembly 33 is located in the lower clearance 31 for locking the casing hanger 21 to the wellhead 11. A seal assembly 35 is located in the upper clearance 29 for sealing the casing hanger 21 to the wellhead 11.
Referring to FIG. 5, the lock assembly 33 includes a collar 37 on the lower end. Collar 37 has an upper flange 39 with a downwardly facing surface that is adapted to mate with and engage the landing shoulder 15 in the wellhead bore 13. A shear pin 41 releasably secures the collar 37 to the casing hanger body 23. When flange 39 contacts the landing shoulder 15, the weight is applied, the shear pin 41 will shear, allowing the hanger body 23 to move downwardly a short distance. A plurality of vertical flutes 43 extend up the hanger body for allowing return flow during cementing of the casing string.
Collar 37 has an interior annular recess 45. Recess 45 is adapted to receive a plurality of washers. Washers 47 are flat steel members, having a hardness of about 60 Rockwell B, which is not as hard as collar 37 or hanger body 23. Each washer 47 is split. The outer diameters of the washers 47 engage the inner wall of recess 45 in a snug fit. The inner diameter of each washer 47 will be located adjacent to a reduced diameter portion 49 formed on the hanger body 23, and will not contact the portion 49. When collar 37 lands on shoulder 15, and hanger body 23 moves downwardly relative to collar 37, the washers 47 will contact an enlarged diameter portion 50 of hanger body 23, which is located above the reduced diameter portion 49 and slightly greater in diameter. The enlarged diameter portion 50 has a diameter that is about 0.016 inch greater than the inner diameter of each washer 47. This causes the washers 47 to deflect downward into a locking position as shown in FIG. 6. The washers 47 undergo permanent deformation beyond their yield strengths when deflected. In the locking position, the hanger body 23 cannot be readily pulled upward relative to the collar 37.
In the locking position, the flat surfaces of the washers 47 incline at an angle a from 5° to 15°, preferably about 10°, with respect to a line perpendicular to the axis of hanger body 23. A 45° bevelled surface 47a is located on the outer lower edge of each washer 47. A 45° bevelled surface 47b is located on the inner upper edge of each washer 47. This results in better surface contact between the washers 47 and the collar 37 and hanger body 23 when in the set position.
A split ring 51 has its lower end in contact with the collar 37. Split ring 51 comprises an expansible annular ring spaced around the hanger body 23. The split ring 51 has a plurality of grooves 53 located on the exterior. Grooves 53 have the same dimension as the locking grooves 17 in the wellhead bore 13. Split ring 51 has three inclined reacting surfaces 55, 57, and 59 located on the interior.
An upper load ring 61 is secured by threads on its interior to the hanger body 23. Upper ring 61 has an outwardly extending flange 62 with an inclined lower surface. Upper ring 61 also has two cam surfaces 63 and 65 which are inclined at the same angle to mate with the reacting surfaces 57 and 59 of the split ring 51. The hanger body 23 also has a cam surface 67 which is inclined at the same angle as reacting surface 55. When collar 37 lands on the landing shoulder 15 and the hanger body 23 continues downward movement, the split ring 51 will not be able to move downward along with body 23 due to its contact with the collar 37. The reacting surfaces 55, 57, and 59 act against the cam surfaces 63, 65, and 67 to result in a radial outward movement. Grooves 53 will engage the locking grooves 17 to lock the casing hanger 21 in place and provide support. Downward force on casing hanger 23 is transmitted through split ring 51 to the grooves 17 and wellhead 11. The locked position is shown is FIG. 1.
A retaining ring 69 is located below the collar 37 for retaining the collar 37 and split ring 51 should the casing hanger 21 later be withdrawn to the surface. To withdraw the casing hanger 21, a force sufficient to overcome the resistance of the washers 47 must be exerted. Preferably this force is around 200,000 pounds.
Referring to FIG. 2, the seal assembly 35 has a metal seal ring 71. Seal ring 71 has an outer annular wall 73 that is spaced radially outward from an inner annular wall 75. This results in an annular cavity 77 located between the walls 73 and 75. A plurality of grooves 79 are located in a seal section 78 of the walls 73 and 75. The grooves 79 on inner wall 75 face inwardly for engaging hanger body 23. The grooves 79 on the outer wall 73 face outwardly for engaging the bore 13 of wellhead 11. Grooves 79 are circumferential grooves parallel to each other. They are larger than the wickers 19 in the wellhead bore 13 and smaller than the locking grooves 17 in the wellhead bore 13. Preferably each groove 79 has a depth of about 1/8 inch, and its centerline is spaced from the centerlines of adjacent grooves by about 1/4 inch. The grooves 79 are rounded, and cylindrical sealing surfaces 80 are located between each groove 79 for sealing contact with the wellhead bore 13 or the hanger body 23. Each sealing surface 80 has a longitudinal height or dimension that is from 1/16 to 3/32 inch. There is a lower groove 81 on each wall 73 and 75 which has a greater depth than the grooves 79. The lower groove 81 is located adjacent to the bottom of the cavity 77 between the walls 73 and 75. Prior to energizing, the radial dimension from the sealing surfaces 80 of grooves 79 on inner wall 75 to the sealing surfaces on outer wall 73 is preferably about 0.030 inch less than the width of upper clearance 29.
A gripping section 83 is located above the seal section on outer wall 73. The gripping section 83 does not contain any grooves 79, and it terminates in a rim 85 on outer wall 73. A plurality of vertical slots 87 extend through the outer wall 73 in the gripping section 83, as shown more clearly in FIGS. 3 and 4. Gripping section 83 aligns with wickers 19 in wellhead 111.
There is a gripping section 89 also on the inner wall 75 located radially inward from the gripping section 83. Gripping section 89 is located above the grooves 79 and adapted to align with a set of wickers 91 formed on the exterior of the hanger body 23. Wickers 91 are located adjacent to the wickers 19 in the wellhead bore 13 when the casing hanger 21 is landed in the wellhead 11. The gripping section 89 is located below the rim 93 of the inner wall 75, which is threaded. A plurality of vertical slots 95 extend through the gripping section in radial alignment with the slots 87. Slots 95, however, do not extend to the top of the rim 93, rather terminate a selected distance below as shown in FIG. 4. A retaining ring 97 is secured to the threads of the rim 93 and located on the exterior of the inner wall 75. The inner wall 75 extends above the outer wall 73 a considerable distance.
An energizing ring 99 is carried with the seal ring 71. Energizing ring 99 has a lower section 101 that is adapted to be forced into the cavity 77. Prior to actuating the seal ring 71, as shown in FIG. 2, the energizing ring 99 is located with its lower section 101 at the entrance of the cavity 77. The lower section 101 is greater in radial thickness than the cavity 77 by at least 0.030 inch, so as to wedge tightly therein and force the inner and outer walls 73 and 75 outward into sealing engagement with the hanger body 23 and the wellhead bore 13. The energizing ring 99 also has a middle section 103 which is of greater radial thickness than the lower section 101 and the cavity 77 between gripping sections 83 and 89. The middle section 103 when in the engaged position as shown in FIG. 1, locates in the upper portion of cavity 77 between the slotted or gripping sections 83 and 89. A tapered area exists between the lower section 101 and middle section 103. Energizing ring 99 also has an upper section 105 that extends above the retaining ring 97 while in the disengaged position. A shoulder 107 is located generally at the junction of the middle section 103 and the upper section 105. Shoulder 107 is located on the interior to contact the lower side of the retaining ring 97 if the seal assembly is being withdrawn.
Energizing ring 99 has a circumferential recess 109 formed in the interior of the upper section 105. Vertical channels 111 extend downwardly in the interior of ring 99 from the upper edge of ring 99 to recess 109. Recess 105 is adapted to be engaged by handling tools with members that enter through slots 111. Rotating the handling tool after the members reach recess 105 will secure the energizing ring 99 to the handling tool. A handling or setting tool shown schematically with dotted lines 112 will extend through channels 111 and contact the upper edge of recess 109 to move downwardly. A different handling tool (not shown) will be used to release energizing ring 99 by moving it upwardly. It will contact a dowardly facing shoulder 115 in recess 109 to move energizing ring 99 upwardly. A passage 113 extends through the lower section 101 to allow liquids contained in the cavity 77 to be purged as the energizing ring 99 enters the cavity 77.
The seal ring 71 is constructed of a mild steel which has a hardness less than about 150 BHN. The material should preferably have a hardness 40-50 BHN less than the hardness of wellhead 11 and hanger body 23. This material is sufficiently soft to permanently deform and seal against the hanger body 23 and the wellhead bore 13.
In operation, the lock assembly 33 will be secured to the hanger body 23 by the shear pin 41. The hanger body 23 will be secured to the upper end of the string of casing (not shown) as it is being lowered into the well. When the flange 39 contacts the landing shoulder 15 (FIG. 5), pin 41 will shear, and hanger body 23 will move downwardly relative to the collar 37 and the split ring 51. The washers 47 deflect downwardly because of the interference fit of the washers 47 between the hanger body 23 and the recess 45 that occurs when the hanger body 23 moves downwardly. The washers 47 serve as wedge means to allow downward movement of the hanger body 23 relative to the collar 37, but to resist any upward movement.
As the hanger body 23 moves downwardly, the cam surfaces 63, 65, and 67, serve as cam means to act against the reacting surfaces 55, 57, and 59 to urge the split ring 51 out into engagement with the grooves 17. The upper end of the split ring 61 will contact flange 62 of the upper ring 61. This will stop downward movement of the hanger body 23. The landing of the casing hanger 21 can be checked by pulling upwardly on the hanger body 23. If the washers 47 resist the upward movement, this indicates that the pin 41 has sheared properly and that the casing hanger 21 is properly locked in place. The split ring 51 will transmit forces on the hanger body 23 to the wellhead 11. Cement can then be pumped down through the casing hanger 21 and string to cement the string in place, with returns flowing through the flutes 43 to the surface.
After the cement has set, the seal assembly 35 can be lowered in place with the setting tool 112. The energizing ring 99 will be secured to the setting tool 112 by shear pins (not shown). The energizing ring 99 will be in the position shown in Fig. 2 while the setting tool 112 lowers the seal assembly 35 into the annular clearance 29. When in place, further downward movement of the setting tool 112 causes the energizing ring 99 to move downwardly. The lower and middle sections 101 and 103 spread the walls 73 and 75 apart. The seal sections 78 seal tightly against the hanger body 23 and the wellhead bore 13. The slotted or gripping sections 83 and 89 are pressed tightly against the wickers 19 and 91 to retain the seal ring 71 in place. The setting tool 112 can then be removed and withdrawn to the surface. The gripping sections 83 and 89 resist upward force tending to push the seal assembly 35 upwardly due to pressure.
To release the seal assembly 35, a handling tool (not shown) is lowered into engagement with the recess 109 and rotated to the right 45° to engage the upper shoulder 114 for release. The handling tool is picked up, causing the shoulder 107 of energizing ring 99 to move up into contact with the retaining ring 97. The entire seal assembly 35 may be withdrawn.
To remove the casing hanger 21, a handling tool must grip the casing hanger 21 and pull it upwardly sufficiently to deform the washers 47. The upward movement allows the split ring 51 to disengage from the grooves 17, allowing the casing hanger 21 to be pulled upwardly.
The invention has significant advantages. The seal is of metal, thus not subject to deterioriation that occurs with some elastomeric seals. The seal can be released. The small cylindrical lands between the sealing grooves provide good sealing surfaces and conform to irregularities. The vertically slotted gripping sections reduce the force required to energize the seal.
While the invention has been shown in only one of its forms, it should be apparent to those skilled in the art that it is not so limited but is susceptible to various changes without departing from the scope of the invention.
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A casing hanger seal for a subsea well uses a seal ring having inner and outer walls spaced radially apart from each other. An energizing ring is moved from disengaged position to an engaged position between the walls, wedging them apart to form the metal seal. Vertical slots are formed in the walls to facilitate expansion. The slots ae located in a gripping section that engages wickers formed on the inner and outer tubular members of the well. Circumferential grooves are located in the sealing areas.
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This application is a continuation-in-part of application Ser. No. 233,034, filed Mar. 9, 1972, now abandoned, of application Ser. No. 478,286, filed June 11, 1974, now abandoned, and a division of application Ser. No. 582,368, now U.S. Pat. No. 4,013,505 issued Mar. 27, 1977.
BACKGROUND OF THE INVENTION
The present invention relates to a method of and an apparatus for deinking printed wastepapers.
In accordance with well-known methods, printed wastepapers have hitherto been deinked in such a way that the feedstock has been exposed to an action of mechanical power, chemicals and heat, particularly in aqueous media. The actual removal of released printing inks from a fiber suspension or pulp has been carried out by washing or by flotation. In the prior art there have existed a large number of processes differing from one another by amounts and types of deinking chemicals used. All processes, however, have been characterized by common basic disadvantages resulting from the very methods of separating printing inks by washing or by flotation.
An essential problem to face in deinking processes resides, in general, in that the released particles of printing inks have to be prevented from being resorbed by fibers, the resorption taking place due to the fact that the aforesaid processes have been carried out in strongly alkaline media and that the fibers soaked with alkaline possess a relatively high adsorptive power. In the deinking processes, the printing inks are usually released within a very broad range of particle sizes, to wit, from the prevailing finest particles up to coarse grained ones which latter are visible with naked eye. It is why the separation of printing inks once released is rather difficult, since it is impossible to separate particles finer than 2 microns from the fiber by flotation. In addition, the flotation methods of separating printing inks, as a rule, lay excessive claims on industrial installations, in view of the size and number of the requisite flotation cells necessary to obtain desirable effects.
Another disadvantage of the flotation processes consists in a technically rather elaborate preparation of an air-dispersion in the flotation cell as well as in a complicated attendance resulting from a considerable sensitivity of the respective processing plant, which depends upon the necessity of absolutely homogeneous dosing rates and upon composition of the wastepapers feedstock. Every change in the composition of the respective wastepaper batch, requires a selective readjustment of the flotation plant as well as of the overall process.
On the other hand, deinking methods wherein the released printing inks are separated by washing, are connected with the generation of a considerable waste water volume and with troubles in processing highly diluted sludges of which removal is usually very elaborate and uneconomical. Any discharge of waste waters left after washing which is fed immediately into recipient water courses without prior liquidation of sludges is forbidden by law.
The purpose of the present invention and the basic object of the same is to overcome the aforementioned disadvantages and to significantly improve the deinking of printed wastepapers.
SUMMARY OF THE INVENTION
In accordance with one feature of our invention we provide a method of deinking printed wastepapers, which comprises the impregnating of the printed wastepapers with a solution, for example, 100 liters of water with dissolved surface-active agents in an amount of from 0.2 to 2.0 per cent by weight of wastepaper charge and with alkali-reacting substances in an amount of from 0.5 to 4.0 per cent by weight of wastepaper charge, the repulping of the same and simultaneously treating it with terpene hydrocarbons or alcohols, aliphatic or aromatic hydrocarbons, or alcohols, such as petroleum, crude oil and the like, or with a mixture thereof, there being added thereto a suitable vehicle, such as high-adsorptive flakes, of which size can be controlled by setting suitable condition of the precipitating process. The printing ink once released in the repulping process coagulates and adsorbs onto the flakes whereby relatively big-size granular particles arise, which are suitable for being separated from the stock in the proposed apparatus as hereinafter referred to.
In order to utilize also the centrifugal component of the separating force during the separating process to be effected in the apparatus proposed, the high-adsorptive flakes can be loaded with some natural or synthetic loading substances, such as bentonite, china clay, blavo fixer, gypsum, barytes, activated silica, magnetite, and the like, said loading substances being added during the precipitating process in an amount of from 0.5 to 5.0 per cent by weight of wastepaper charge, together with terpene hydrocarbons, or alcohol in an amount from 0.2 to 2.0 per cent by weight of metal soap used. The flakes of the resulting precipitate loaded with the aforementioned loading substances keep in the process according to the present invention their shape characteristics while their power of adsorbing themselves onto the released printing ink particles even increases. The temperature of the precipitation process should be kept within the limits of from 15 to 70° Centigrade. The concentration of the fatty and bituminous acids and the amount of the loading substances as well as of the terpene alcohol added is to be determined in accordance with the end use, that means the type of wastepaper to be processed, of the printing ink, or the like.
For carrying out the aforedescribed method of deinking printed wastepapers an apparatus has been proposed. The apparatus operates upon the principle of a latent vortex and designed for separating the aforementioned granular particles with printing ink content from the wastepaper stock, and comprises a series of separator batteries both the diameter and length of which cells gradually decrease in downstream direction, the conicity and the cross-section thereof being predetermined by the differential size and gravity of said granular particles as they pass through the separating system.
The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of a specific embodiment when read in connection with the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING
The single sheet of drawing shows a somewhat schematical vertical sectional view of an apparatus for deinking printed wastepapers.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Discussing now the drawings in detail, it will be seen that reference numeral 1 identifies a substantially vertical impregnator-repulper, it being irrelevant whether the repulper cell and the impregnator form one, or whether two separate cells are used and the fiber raw material is conveyed from the impregnator into the repulper. A suitable vessel, e.g. the impregnator-repulper 1 is adapted to be filled up, within given time intervals, with a solution of chemicals supplied from a preparation tank 2 and with wastepapers supplied by a conveyor 18, the cell content being simultaneously heated to a temperature of from 20°to 70° Centigrade. After an obligatory retention period of impregnation within the range of from 5 to 60 minutes has elapsed, the actual repulping process takes place, wherein granular particles with printing ink content will arise. Once repulped, the raw feed stock is discharged into a storage tank 3 of which content will then be forced by means of a pump 4 into a thick pulp separator 5 where it is freed from heavy contaminants prone to cause failures in further processing. The term"thick pulp separator" means a high density cleaner serving for the separation of impurities having a specific weight greater than that of pulp fiber, e.g. "Dickstoffreiniger" produced by the firm Voith GmbH (West Germany), working with an average consistency of 4%. The stock, once freed from said heavy contaminants will then be advanced to a strainer 6 where not yet repulped remnants are separated therefrom. The stock is then conveyed into a diluting tank 8 where it is diluted to a value of from 0.3 to 1.2 percent of dry solid fiber content. From the diluting tank 8 the diluted stock is forced by another pump 9 to the first step of a separator battery 10 of such a capacity to enable, as early as in said first step, the coarsest proportions of granular particles with printing ink content to be separated. From the separator battery 10, the purified or fair stock is conveyed into a tank 11 from which it will then be pumped by means of a pump 12 onto another separator battery 13 designed to separate therefrom the remaining granular particles with printing ink content. Diluates coming from both the separatory batteries 10 and 13 are discharged into a tank 14 wherefrom they are repumped by means of a pump 15 onto another separator battery 16. The purified stock discharged from the aforesaid separator battery 16 will then be recycled back into the diluting tank 8 and the ejects are collected in a tank 17 for reuse. The fair stock withdrawn from the separator battery 13 is transported into inlet holes 22 of a final separator battery 21 designed for separating the finest contaminants therefrom. The separator battery 21 is formed with an upright cylindrical vessel 23 having in its top portion said tangential inlet hole 22 and provided with a tangential outlet hole 24 in the bottom portion thereof. The two holes 22 and 24, respectively, are oriented in the direction of a latent vortex along an outer vortex. In addition, the cylindrical vessel 23 is provided with an axially disposed outlet tube 25 designed for withdrawing the finest separated contaminants from its uppermost part while in its lowermost part the vessel 23 is provided with a tube 26 for intake of a gaseous medium or water/gas dispersion into the separator battery 21. Before entering the separator battery 21 said gaseous medium is caused to pass through a perforated partition 27 designed for uniformly distributing the same all over the cross-section of the separator battery 21 wherein the intake rate of the substance supplied into the upper tangential inlet hole 22 is to be selected so that the ascension velocity of the gaseous medium or water/gas dispersion be higher than the descension one of the suspension flowing through the cross-section of the separator battery 21.
It is to be understood that both the diameter and the length of separator cells of the entire separating system gradually decrease in downstream direction and that the conicity and cross-section thereof are predetermined by the differential size and gravity of said granular particles as they pass through the system.
The merits of the proposed method and apparatus relative to well-known methods and apparatuses for deinking printed wastepapers as heretofore used consist in that the floor space requisite for the installation of the apparatus according to the present invention is relatively small because of small dimensions of the separating system and further that the aforesaid apparatus lays but low claims both upon power consumption and attendance, and finally that it is but slightly responsive to any changes encountered in the wastepaper charges.
An important secondary effect of the aforedescribed method and apparatus resides also in the fact that the proportion taken off from the separating system can be used as an admixture to low-grade fibrous products so that they enable thus any losses on fiber to be practially reduced to minimum.
The decrease of the solution volume used in the process of deinking printed wastepapers according to the proposed method performed in the respective apparatus is given but by the loss on the solution carried along with the deinked pulp to be processed in further steps.
While the invention has been illustrated and described as embodied in a method and apparatus for deinking printed wastepapers, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that from the standpoint of prior art clearly constitute essential characteristics of the generic or specific aspects of this invention and therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.
EXAMPLE I
3 kgs of waste newsprint and 0.5% by weight of the paper of a surface active agent such as Alfonal K which is a commercial designation of a product of condensation of fatty acids with diethanol amine, in a solution were placed into a vertical impregnator repulper. To the content in the impregnator-repulper 1% by weight of the paper of sodium hydroxide was added. The waste paper was allowed to absorb the mentioned substances for 20 minutes within which period the fiber swelled, the printing ink - paper bonds released. The mixture was heated to 50° C. and defibering 2.5% by weight of the paper of a terpenic hydrocarbon (e.g. pine oil) and thereafter 5% by weight of the paper of highly adsorptive flakes were added. The flakes were prepared separately by precipitating a solution of sodium salt of tall oil soap in the amount of 0.09 kg of a calcium chloride solution in a stoichiometric excess and with an additive of 0.06 kg of a loading agent such as e.g. china clay. In this process due to a mechanical effect, particles of printing ink were stripped and separated from the fibers, while the printing inks were dispersed in the substance suspension and adsorbed onto the highly adsorptive flakes of the vehicles. After the defibering process, the feed stock was discharged into a storage tank and then pumped into a thick pulp separator where it was freed from heavy contaminants. The stock was then advanced into a strainer where not yet repulped remnants were separated therefrom. Then the stock was conveyed into a diluting tank and was diluted to a value of 0.8% of dry solid fiber content. From the diluting tank the diluted stock was forced into an apparatus comprising several batteries of separators, where granular flakes with printing ink content were separated in latent vortex. The final purification was carried out in the last battery of separators.
Under the term "alkali reacting compounds", as used herein, there are to be understood, in general, alkalinously reacting compounds, such as e.g. caustic soda lye, sodium carbonate, or the like.
Examples of alkali reacting compounds:
Sodium hydroxide;
Potassium hydroxide;
Sodium silicate;
Sodium carbonate.
Under the term "surface-active agents" as used herein there is meant any surface-active agents characterized by having wetting and detergent power.
Examples of surface active agents:
Alkyl benzene sulphonates, e.g. Dubaral;
Alkyl ether polyoxyethylene sulphonates;
Alkyl phenyl ether polyoxyethylene sulphonates;
Polyoxyethylene alkyl phenol ethers;
Polyoxyethylene alkyl ethers;
Polyglycol esters of fatty acids;
Alkylolamids of fatty acids, e.g. Alfonal K;
Quarternary condensation products of fatty amine with ethylene oxide, e.g. Syntegal V 20.
In general all surface active agents usually used with deinking, at which their wetting power and their washing power are utilized.
EXAMPLE II
3 kgs of waste halftone paper and 1.5% by weight of the paper of a surface active agent such as e.g. Syntegal V 20 in a mixture with Alfonal K in ratio 2:1 were placed into a vertical impregnator-repulper. To the content in the impregnator-repulper 1 % by weight of the paper of sodium hydroxide was added. The wastepaper was allowed to absorb the mentioned substances for 20 minutes within which period the fibers swelled, the printing ink binders became softened and dissolved and the printing ink - paper bonds released. The impregnation was carried out at a consistency of 6% by weight of paper and at a temperature of 50° C. The mixture was defibered for 30 minutes. At the beginning of the defibering, 2% by weight of the paper of terpenic hydrocarbons, e.g. pine oil and thereafter 10% by weight of the paper of highly absorptive flakes were added. The flakes were prepared separately by precipitating a solution of sodium salt of a mixture of soft soap and napthenic soap in ratio 3:1 in the amount 0.09 kg of a calcium chloride solution in a stoichiometric excess. Napthenic soaps are mixtures of alkaline salts of napthenic acids. Napthenic acids are higher saturated monocarbon acids in the chain of which there are cyclopen tane rings; carboxyl group is usually situated at the end of the alkyl chain. In this process due to a mechanical effect particles of printing ink were stirred and separated from the fibers, while the printing inks were dispersed in the substance suspension and absorbed onto the highly absorptive flakes of the vehicles. After the defibering process, the feed stock was discharged into a storage tank and then pumped into a thick pulp separator where it was freed from heavy contaminants. The stock was then advanced into a strainer where not yet repulped remnants were separated therefrom. Then the stock was conveyed into a diluting tank and was diluted to a value of 0.8% of dry solid fiber content. From the diluting tank the diluted stock was forced into an apparatus comprising several batteries of separators, were granular flakes with printing ink content were separated in latent vortex. The final purification was carried out in the last battery of separators.
Latent vortex relates to flowing at which every particle revolves in a circle and moves without rotating on its own axis (this is valid for the whole range of the vortex with the exdeption of its center). It obeys the relationship VR n = constant, at n= 0-0- 1. Reference* Technicky slovnik naucny (Technical Encyclopedia, Praha SNTL, 1964).
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An apparatus for deinking printed wastepapers in a system of separators through which printed wastepapers, previously impregnated with surface-active agents and alkalis, and repulped in the presence of an organic hydrocarbon compound and high-adsorptive flakes obtained by precipitating solutions of metal soaps of fatty or bituminous acids with solutions of salts of alkaline earths, are forced. The adsorptive flakes containing printing ink are separated from the repulped paper stock by latent vortex action.
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TECHNICAL FIELD
[0001] The invention relates to controllers for controlling the play of computerised games, more particularly but not exclusively, the invention relates to an actuator system of a game controller for a gaming console.
BACKGROUND
[0002] There are many different types of gaming consoles currently available for operating a video game. For example, Microsoft®, Sony® and Nintendo® manufacture the Xbox®, Playstation® and Wil® gaming consoles, respectively. The gaming consoles typically include a game controller so that a user can control the operation of the video game.
[0003] Some known game controllers include a form of actuator system for the operation of control of the functions of the video games. Actuators, buttons or other depressible or manually operable devices are typically used for controlling discrete actions such as the firing of a weapon or an attack command. It is known to provide a button or actuator which is intended to be operable by the index finger of a user; such buttons are commonly known as triggers.
[0004] At times, dependent upon the video game being played, it can be necessary to depress the trigger a distance before the trigger initiation point is reached and the command actually acknowledged. This renders part of the depressing action futile. Likewise, after the command has been operated, it is often possible to carry out further depression of the trigger past the trigger initiation point. This further depression is unnecessary and may also be disadvantageous.
[0005] Furthermore, in other situations in some video games, the strength of a command is increased or decreased dependent upon how frequently the trigger is depressed. As such, depressing the trigger the whole distance is unnecessary and excessive for the command or operation required.
[0006] It is desirable to have a controller, particularly for gaming applications, that is more responsive or has less scope for allowing unnecessary over-movement by the user of the controller.
[0007] Due to the rapidly expanding gaming market and development of involved games invoking considerable player input, it is desirable for players to be able to customise their controllers in order to gain increased control in a variety of gaming circumstances.
[0008] The present invention seeks to improve upon or at least mitigate some of the problems associated with controllers of the prior art by providing a game controller, which includes an adjustable trigger system that has a mechanism to allow the end user to control or recalibrate the maximum and/or minimum trigger positions.
SUMMARY
[0009] There are a variety of different commands available for the trigger functions of a game controller and the adjustable trigger system of the various embodiments of present invention now provides use within the option to customise the trigger settings to suit the individual game at the time of operation.
[0010] In some embodiments the trigger system includes adjustments for the depression of the trigger so that it is already to some degree, “depressed,” before any contact is actually made with the trigger by the operator (player).
[0011] In some embodiments the trigger system includes adjustments for the amount that the trigger is depressed before there is no more motion available to be made by the operator. This removes any unnecessary distance travelled by the trigger.
[0012] The present invention provides a method of fully controlling both of the above features simultaneously for the amount of depression inflicted on the trigger without contact, and the amount of available motion to give the greatest advantage in any gaming circumstances.
[0013] In some embodiments, there would be the ability to switch the trigger adjustments between incremented settings on the threaded adjustments. This would allow the end user to quickly and accurately calibrate the triggers between customised or pre-set settings.
[0014] In some embodiments, there would be a thread cut directly into the chassis of the controller to take the threaded adjustment screws.
[0015] In other embodiments the thread in the chassis may be achieved via the fitting of a threaded insert.
[0016] There is provided an apparatus for supplying user inputs to a computer program, such as a game program, for controlling the game program, the apparatus comprising at least one depressible trigger mechanism and having a mechanism for manual adjustment of the depressible range of the trigger mechanism.
[0017] There is provided an apparatus for supplying user inputs to a computer program, such as a game program, for controlling the game program, the apparatus comprising at least one depressible trigger mechanism and having a mechanism for manual adjustment of the start position of the trigger mechanism.
[0018] There is provided an apparatus for supplying user inputs to a computer program, such as a game program, for controlling the game program, the apparatus comprising at least one depressible trigger mechanism and having a mechanism for manual adjustment of the stop position of the trigger mechanism.
[0019] There is provided a game controller for controlling electronic games, including a housing, at least one depressible trigger at least in-part exposed relative to the housing, said at least one depressible trigger being in operational association with electrical circuitry contained within the housing which electrical circuitry is controlled by depression of the each depressible trigger for manipulating electrical outputs of the circuitry for controlling electronic games and having a mechanism for manual adjustment of the depressible range of the trigger mechanism.
[0020] There is provided a game controller for controlling electronic games, where the game controller includes a controller chassis, a trigger body, a trigger mechanism chassis, a strike plate coupled to the trigger body, a first trigger adjustment control screw received in a screw thread disposed within the controller chassis, and a second trigger adjustment control screw received in a screw thread disposed within the controller chassis. A portion of each of the first trigger adjustment control screw and second trigger adjustment control screw engages with a respective portion of the strike plate and said portion of each of the first trigger adjustment control screw and second trigger adjustment control screw each create an end stop to limit the trigger movement.
[0021] Preferably the strike plate is integral with the trigger body.
[0022] There is additionally provided a method of adjusting the range of movement of a button on a game controller for controlling electronic games. The method includes providing a game controller including a controller chassis, a trigger body, a trigger mechanism chassis, a strike plate coupled to the trigger body, a first trigger adjustment control screw received in a screw thread disposed within the controller chassis, and a second trigger adjustment control screw received in a screw thread disposed within the controller chassis. In accordance with an aspect of the exemplary method, a portion of each of the first trigger adjustment control screw and second trigger adjustment control screw engages with a respective portion of the strike plate and said portion of each of the first trigger adjustment control screw and second trigger adjustment control screw each create an end stop to limit the trigger movement rotating one of said first trigger adjustment control screw or second trigger adjustment control screws to adjust the position of the end stop.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Exemplary embodiments of the invention will now be described with reference to the accompanying drawings, in which:
[0024] FIG. 1 is a front view of a game controller.
[0025] FIG. 2 is a cut-away side view of the trigger mechanism according to a first illustrated embodiment of the invention;
[0026] FIG. 3 is an enlarged view of FIG. 2 showing the trigger mechanism of FIG. 2 ;
[0027] FIG. 4 is a cross-sectional of view taken through the front of the trigger mechanism;
[0028] FIG. 5 is a full front profile showing hidden detail of trigger mechanism;
[0029] FIG. 6 is a side view of a trigger mechanism according to a second embodiment of the invention showing another mechanism for adjusting trigger travel motion;
[0030] FIG. 7 is a front view depicting a trigger mechanism according to a third embodiment having incremental trigger calibration; and
[0031] FIG. 8 is an enlarged view of the trigger mechanism system shown in FIG. 7 .
DETAILED DESCRIPTION OF THE INVENTION
[0032] Detailed descriptions of specific embodiments of the game controller and its trigger mechanisms are disclosed herein. It will be understood that the disclosed embodiments are merely examples of the way in which certain aspects of the invention can be implemented and do not represent an exhaustive list of all of the ways the invention may be embodied. Indeed, it will be understood that the game controller and its trigger mechanisms described herein may be embodied in various and alternative forms. The figures are not necessarily to scale and some features may be exaggerated or minimised to show details of particular components. Well-known components, materials or methods are not necessarily described in great detail in order to avoid obscuring the present disclosure. Any specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the invention.
[0033] FIG. 1 is exemplary of a game controller 100 in which the present invention could be employed. The game controller 100 includes a bumper control function 102 , button control functions 104 , analogue joystick controls 106 , and a trigger body 108 . FIG. 1 illustrates the positions of the trigger body 108 in relation to the position of the aforementioned features of the game controller 100 .
[0034] FIG. 2 is a cut-away view of part of the game controller 100 illustrating an adjustable trigger mechanism according to a first embodiment of the invention. The game controller 100 also includes a controller chassis 110 , which encloses its internal components. The trigger body 108 can extend at least partially through an opening in the controller chassis 110 . Referring now also to FIGS. 3-8 , the game controller 100 also includes:
[0035] a printed circuit board (PCB) 112 ;
[0036] a trigger mechanism chassis 114 fixed to the PCB 112 ;
[0037] an adjustment strike plate 116 integral to the trigger body 108 ;
[0038] a first trigger adjustment control screw 118 for adjustment of trigger depression;
[0039] a second trigger adjustment control screw 120 for adjustment of the trigger command initiation point;
[0040] a threaded insert or screw thread 122 cut into the controller chassis 110 ;
[0041] a trigger pivot bearing 124 integrally formed with the trigger mechanism chassis;
[0042] a trigger sensor link arm 126 ; and
[0043] a trigger motion sensor 128 .
[0044] FIG. 3 is an enlarged section of FIG. 2 showing in more detail the trigger adjustment mechanism in accordance with the invention.
[0045] FIG. 4 is a cross sectional view of the trigger mechanism. In this embodiment the trigger mechanism has two trigger adjustment control screws 118 , 120 ; first trigger adjustment control screw 118 for adjustment of trigger depression, and second trigger adjustment control screw 120 for adjustment of trigger command initiation point as shown in FIG. 2 respectively.
[0046] In this embodiment the first and second trigger adjustment control screws 118 and 120 that are used are grub screws but could be many different threaded mechanisms.
[0047] In this embodiment the screw thread 122 for receiving the screw mechanisms is cut into the chassis 110 of the game controller 100 as shown in FIGS. 2 and 3 , respectively. In other embodiments, it would be possible to use threaded inserts with nylon locking systems or entire adjustment mechanisms 130 , 132 fitted as a complete component that could be inserted through an aperture in the controller chassis 110 in such embodiment it is envisaged that the user may be able to adjust the trigger settings without the use of a tool, for example by providing a grip coupled to the screw thread, preferably this would be integral with the screw thread as shown in FIGS. 7 and 8 .
[0048] In some embodiments, the position of the trigger body 108 would be adjusted by use of a specified tool that would be provided to turn the first and second trigger adjustment control screws 118 and 120 , which are located next to the trigger body 108 , on the controller chassis 110 .
[0049] One advantage of the present invention is that it allows adjustments to be made to the trigger response; such adjustment could be customised to suit the nature of the video game that is in use at the time of operation and the skill of the operator. For example, in combat style games involving a shooting function it is often the case that the trigger would need to be depressed a certain amount before any command was prompted. The second trigger adjustment control screw 120 can be adjusted so that the command was prompted with any amount of depression of the trigger body 108 , by using the required tool (for example an Allen key, or hex or star driver, cross head or flat head screwdriver, spanner or wrench) to turn the second trigger adjustment control screw 120 , whereby driving it into or out of the controller chassis 110 by virtue of the threaded insert or screw thread located within controller chassis 110 .
[0050] After reaching or passing the command initiation point no further commands are given from the trigger sensor link arm 126 to the trigger motion sensor 128 ; therefore the first trigger adjustment control screw 118 which controls the degree of trigger depression allows the operator to restrict the amount of travel available to the trigger body 108 , as they desire. The first trigger adjustment control screw 118 would impede the movement by striking the adjustment strike plates, which are preferably formed integrally with the trigger body 108 , which trigger body 108 is pivotally mounted preferably on a trigger pivot bearing which may also be integral to trigger mechanism chassis 124 .
[0051] Such an adjustment would directly relate to the majority of combat style games or other varieties of firing operations in video games.
[0052] The present invention could find application in a variety of other video games genres but for the simplicity of this disclosure reference is made to combat style games.
[0053] A further advantage of the present invention is that it minimises the amount of motion an operators finger must travel, therefore minimising the recovery time after trigger initiation contacts have been made allowing the operator to commence command prompt again and again more rapidly, or to operate different commands quicker. As the movement that is required to operate commands detected by the trigger motion sensor 128 , by depressing the trigger body 108 , the risks of any related repetitive strain injury acquired due to the repeated movement of the finger when operating the trigger function would be greatly reduced. In known controllers the operator may be require to move their finger 11 mm whereas in the present invention adjustment of the first trigger adjustment control screw 118 and the second trigger adjustment control screw 120 allow the operator to reduce the required movement of their finger to 5 mm thus reducing the overall motion required by the operator by over 50% of the initial movement required, whereby providing a health benefit to users retaining healthy joints after many years of vigorous gaming. Repetitive strain injury is a clinically proven medical issue related to hours of repeated movements made during activities like the movements made while depressing the trigger function of the controller.
[0054] In other video game genres, such as driving games, trigger response could be controlled by adjustment of the first trigger adjustment control screw 118 and the second trigger adjustment control screw 120 to allow the operator greater control over breaking and accelerating functions of the game, for example restricting maximum throttle settings and breaking level settings for difficult corners. This could be adjusted by assessing where the greatest advantageous breaking or accelerating position would be, and then recreating this position with the trigger adjustment control screw for adjustment of trigger depression 118 .
[0055] In this application the degree of the trigger body 108 depression is detected by trigger motion sensor 128 which are coupled together by the trigger sensor link arm 126 . The degree of depression of the trigger body 108 is converted into a signal which signal directly relates to a command to be executed by the video game for example the amount of acceleration or braking to be applied. The trigger motion sensor 128 is connected to the trigger mechanism chassis 114 coupled to the printed circuit board 112 . The present invention provides a device to restrict the range of movement of the trigger body 108 which the trigger motion sensor 128 is effectively able to detect, and thus limit the magnitude of the command which can be made by the operator when depressing trigger. A further advantage of this embodiment is that the ergonomic design of the controller is not compromised.
[0056] FIG. 6 depicts the use of a stopping block 134 for control of trigger depression, this could be achieved by insertion into the base of the trigger of a screw comprising screw head which interacts with controller chassis 110 . This system could be used instead of the trigger adjustment control screw 118 for adjustment of trigger depression. This system may incorporate a stopping block of the desired shape and size to prevent the trigger from depressing fully and this would be attached via a screw fixing into a threaded portion of the trigger body 108 , or by any other means of mechanical fixing such as those that would be apparent to those skilled in the art. The stopping block 134 could be interchangeable with stopping blocks or different dimensions depending on the intended application and the degree to which movement of the trigger is to be restricted. The screw head itself may be shaped such that the angular orientation of the screw with respect to the controller chassis 110 determines the degree of trigger movement, for example the outer surface of the screw head could be any noncircular shape such as oval or spiral shape, wherein the radial dimension of the screw head is not constant. In such embodiment is envisaged that trigger adjustment control screw 120 may also be employed in order to provide adjustment of trigger command initiation point to achieve fully adjustable trigger commands.
[0057] It can be appreciated that various changes may be made within the scope of the various embodiments of present invention, for example, the size and shape of the features may be adjusted. In other embodiments of the invention it is envisaged that a system could incorporate several button or slider controls on the external case of the controller which may be adjusted to select pre-set ranges of movement, or pre-set trigger depression or preset trigger initiation command points. Each of these could be pre-set in manufacture or by the operator to correspond to popular video games or specifically chosen video games that the operator has chosen for maximum efficiency. It is also envisaged this invention could be used for other buttons provided on the controller. It is envisaged the invention could be employed with digital sensors or switches which generate digital signals having an on state and an off state since such switches typically require a predetermined range of movement to change states such that required range of movement to change states can be reduced, It is also envisaged this invention could be incorporated to adjust the button depression depth required of such digital switches to its greatest point before such a command for the function it controls would be given.
[0058] In some embodiments the first trigger adjustment control screws 118 and the second trigger adjustment control screw 120 can be entirely released restoring the full range of trigger movement.
[0059] It will be recognised that as used herein, directional references such as “top”, “bottom”, “front”, “back”, “end”, “side”, “inner”, “outer”, “upper” and “lower” do not limit the respective features to such orientation, but merely serve to distinguish these features from one another.
[0060] While particular embodiments of the invention have been shown and described, numerous variations and alternate embodiments will occur to those skilled in the art without departing from the scope of the present invention.
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A game controller for controlling video games or other electronic interactive systems, having an adjustable trigger system for calibration or customized control of trigger action. The game controller includes a controller chassis and an actuator system, which includes a trigger body, a trigger mechanism chassis, a strike plate coupled to the trigger body, a first trigger adjustment control screw received in a screw thread disposed within the controller chassis, and a second trigger adjustment control screw received in a screw thread disposed within the controller chassis, wherein a portion of each of the first trigger adjustment control screw and second trigger adjustment control screw engages with a respective portion of the strike plate, and said portion of each of the first trigger adjustment control screw and second trigger adjustment control screw each create an end stop to limit the actuator movement of the trigger body.
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BACKGROUND AND SUMMARY OF THE INVENTION
This invention relates generally to a refrigeration circuit through which a refrigerant is circulated. A typical circuit comprises a compressor, an evaporator, an expansion valve, and a condenser as principal components, and an example of such a circuit is contained in an automobile air conditioning system. Such a system also comprises a desiccant assembly in the circuit to perform a desiccant function on the refrigerant. More specifically, this invention relates to a new and unique desiccant assembly and method.
In a typical refrigeration circuit, such as the type commonly used in automobile air conditioning systems, refrigerant is circulated through the circuit to produce cooling. The energy input to the circuit is via the compressor which is driven from the automobile's engine and which serves to create a source of pressurized liquid refrigerant which is allowed to expand through the expansion valve into the evaporator. In the evaporator the expanding refrigerant absorbs heat thereby producing cooling of a medium which is in heat transfer relationship with the evaporator. ln an automobile air conditioning system that medium is air. From the evaporator the refrigerant passes to a condenser where the heat absorbed in the evaporator is rejected. The heat rejection is to the outside environment in the described automobile air conditioning usage. The refrigerant is then drawn from the condenser by the compressor where it is again compressed and the cycle repeated.
It has been found desirable for the circuit to have a desiccant which acts on the refrigerant, basically for the purpose of collecting entrained moisture which may have been introduced into the refrigeration circuit for any of a number of possible reasons. In other words, the desiccant serves to prevent moisture from circulating through the circuit where its presence might give rise to undesired consequences.
Since the refrigeration circuit is a closed one, it is vital for the desiccant to be in an operative relationship with the refrigerant in a manner which maintains the closed nature of the circuit. The prevailing practice is for the desiccant to be contained in a desiccant assembly which comprises a cylindrical container having an inlet and an outlet for connecting it into the circuit. The desiccant is itself located within the container, and is typically contained in a bag which fits into the bottom of the cylindrical container. The construction of the container is such that refrigerant flow is directed through the desiccant so that the latter can perform its intended function of removing moisture from the refrigerant.
The prevailing practice in the fabrication of such desiccant assemblies comprises the container being formed of two separate parts, such two half shells or a base and a cap, joined together around a circular seam. The two parts are typically drawn or stamped. The various component parts of the desiccant assembly are assembled into the two container parts before the latter are seamed together.
This known process for fabricating the desiccant assembly has therefore comprised operations performed on two separate container parts, a subsequent assembly of various parts, and finally a joining of the two container parts together, such as by brazing in the case of aluminum or aluminum alloy, or by welding in the case of steel. The presence of the seam is a potential source for leakage, and from a practical manufacturing standpoint in mass production, reliability of this type of process has been shown to be poor. Significant reject and scrap rates have been tolerated as being a necessary consequence of the known manufacturing procedures. Even though a seam may visually appear satisfactory, there can be minute pin holes which form leak paths. The effectiveness of seaming procedures can be impaired because of the residual presence of materials used to facilitate the formation of one or both of the two container parts, i.e. the residual presence of lubricants or drawing compounds for instance when the parts are drawn or extruded.
The present invention is directed to a new and improved desiccant assembly which avoids the disadvantages associated with the prior manufacture of desiccant assemblies as just described. An important attribute of the invention is that it can significantly reduce the reject and scrap rates in the mass production of such desiccant assemblies. Moreover it is of a more efficient construction since it uses a single part to form the desiccant container rather than two separate parts seamed together.
The invention involves the application of friction spinning to the ends of seamless tube stock to form closed endwalls whereby the container comprises a single unitary body having a sidewall and integral endwalls. With the invention the continuous seam which was required in the prior manufacture is eliminated. The invention also involves the fabrication of various components and their subassembly to the one piece container at various stages of the fabrication process. Hence, related aspects of the invention involve the method of assembly.
The invention is adaptable to various packaging and geometrical configurations. In an automobile usage where the desiccant assembly may be located in the engine compartment, it is often necessary for the assembly to be in a limited space and for the inlet and outlet to be in particular geometric relationship to the container so that refrigerant lines can be connected to them. The invention is advantageously useful with different configurations, such as an external tube version and an internal tube version, examples of both of which will be subsequently hereinafter described.
In application of the invention to automobile air conditioning systems, important benefits accrue. The preferred embodiment of the present invention utilizes light-weight material which is consistent with the efforts of the automobile industry to make weight savings and fuel economy gains. It is also a better finished product suited to the quality improvement effort of the industry than is the prior multi-piece body construction.
The foregoing features, advantages and benefits of the invention, along with additional ones, will be seen in the ensuing description and claims which should be considered in conjunction with the accompanying drawings. The drawings disclose a preferred embodiment of the invention according to the best mode contemplated at the present time in carrying out the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal sectional view through a component used in the desiccant assembly of the present invention at a beginning stage of its fabrication process.
FIG. 2 is a fragmentary view of a portion of FIG. 1 after the performance of a further particular fabrication step.
FIG. 3 is a view similar to FIG. 1 illustrating the completion of still further fabrication steps.
FIG. 4 is a view similar to FIG. 1 illustrating an intermediate stage of the fabrication process subsequent to FIGS. 2 and 3.
FIG. 5 is a fragmentary view taken generally within circle 5 of FIG. 4 but in an enlarged section and including a further fabrication step.
FIG. 6 is a view similar to FIG. 4, but after the performance of subsequent fabrication steps.
FIG. 7 is a view similar to FIG. 6 after the performance of the final fabrication step, and therefore shows the completed desiccant assembly. This view is taken at 90° to FIG. 6.
FIG. 8 is a top plan view of FIG. 7 rotated 90°.
FIG. 9 is a block diagram useful in explaining a preferred sequence of fabrication steps relating to the preceeding FIGS. 1-8.
FIG. 10 is a longitudinal sectional view illustrating a second version of desiccant assembly embodying principles of the invention.
FIG. 11 is a longitudinal view of the exterior of the version of FIG. 10 upon completion.
FIG. 12 is a top plan view of FIG. 11.
FIG. 13 is a longitudinal view of certain of the component parts of the second version shown apart from the assembly.
FIG. 14 is a block diagram useful in explaining a preferred sequence of fabrication steps for the version of FIGS. 10-13.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIGS. 1-9 relate to the fabrication of a desiccant assembly 20 which is shown in its finished form in FIGS. 7 and 8.
Referring first to FIG. 1 a piece of circular walled, seamless tube stock 22 is cut to a length appropriate to the final finished dimension for the desiccant assembly's body. The tube stock 22 will ultimately form a one-piece body in the finished assembly. The ends of the tube stock are shown to be cut at right angles to the main axis 24. The preferred material is aluminum or an aluminum alloy. This is represented by the step 100 in FIG. 9, and it is followed by a de-greasing step 101.
A friction spinning operation is then conducted on one end of the tube stock 22 for the purpose of forming an integral end wall. This result is shown in FIG. 2 which depicts the finished end wall 26 which is integral with the side wall 28. FIG. 2 shows the end wall fully closed. This step is designated 102 in FIG. 9.
The friction spinning process is conducted using conventional friction spinning procedures. The initial cut length of the tube stock 22 is greater than the finished length of the one piece body so as to take into account end wall formation by friction spinning.
A typical spinning procedure comprises the tube stock being chucked on the spindle of a spinning machine (not shown) and spun about axis 24 at a suitable speed. A suitable tool such as a spinning wheel is operated to engage the end of the spinning tube stock to displace it radially inwardly to form the integral end wall 24. The end wall may have a shape which progressively increases in thickness in the radially inward direction.
During the friction spinning operation the spinning rate and the feed of the spinning wheel which is used to close the end of the tube may be set in such a way that the central region of the end wall outer surface actually becomes molten. This procedure promotes a superior closure of the end wall.
The result can be beneficial from the standpoint of efficient use of material because a circular cylindrical walled vessel has inherent hoop strength in the circumferential direction around its sidewall. Thus from the standpoint of structural considerations the sidewall can be of a lesser thickness than the end wall and that is a construction which can be achieved through the use of the friction spinning procedure.
The next step (FIG. 3) involves the creation of certain holes, with the particular version which is the subject of FIGS. 1 through 8 having three holes in its sidewall spaced from the open top thereof and a fourth hole in the integral end wall 26. Only two of the three holes in the sidewall appear in FIG. 3 since the remaining hole is in the portion that has been sectioned away. The three holes which do appear in FIG. 3 are identified by the reference numerals 30, 32, and 34. The holes are utilized for the attachment of additional component parts to the one piece unitary body formed from tube stock 22. The two holes 30 and 32 are concentric to radials from axis 24 while hole 34 is concentric with axis 24.
Since the tube stock 22 has a circular cylindrical wall, it may be appropriate to coin the stock material around the margins of the sidewall holes so that each of the holes is disposed in a flat plane rather than on a circularly curved surface corresponding to the radius of curvature of the sidewall.
It was previously mentioned that end wall 26 was formed to be fully closed. Where a hole, such as the hole 34, is to be provided in the integral end wall it is possible that the friction spinning procedure could produce a substantially closed but not a fully closed end wall since a hole is to be provided in the end wall in any event. This however will depend upon the particular procedure.
These steps of punching the holes and coining whatever flat areas may be required are represented by the step 104 in FIG. 9, although the drawings do not specifically show any coined areas.
With the tube stock in the stage of fabrication represented by FIG. 3, it is ready for subsequent brazing operations to attach additional components which are also aluminum or aluminum alloy. In order to assure optimum brazing it is desirable to perform a de-greasing operation to remove undesirable contaminants from the metal, and this de-greasing step is represented by the reference numeral 106 in FIG. 9.
FIG. 4 shows a further stage of the fabrication process where additional components have been assembled. These additional components are a tube, generally 40, an inlet fitting 42, and a pair of valve core fittings 44 and 46, fitting 46 not appearing in FIG. 4.
Tube 40 fits into hole 34, fitting 42 fits into hole 32, and fitting 44 fits into hole 30. The remaining valve core fitting 46 has a fit with the hole which is not shown in FIG. 3; however the two valve core fittings and the two holes with which they fit are identical, and they are located generally diametrically opposite each other on sidewall 28.
The tube 40 is fabricated into the form illustrated in FIG. 4 prior to its being fitted into hole 34. The fabrication steps for tube assembly 40 are represented by the reference numerals 108, 110, 112 and 114 in FIG. 9.
The steps involve cutting tube stock 48 to an appropriate length (step 108) and then swaging a locating ring 50 at an appropriate location (step 110) so that when the tube is inserted into hole 34 the locating ring serves to limit the extent to which the tube is inserted, and thereby correctly locate the tube. In addition to the step of swaging the locating ring onto the tube, one or more very small bleed holes 52 are either pierced or drilled (step 112) through the sidewall of the tube so that they will be located within the interior of the one-piece container body in the finished desiccant assembly. With the small tube having been processed through the steps 108, 110, and 112, it is now ready for the brazing operation, and it is therefore appropriate to degrease the tube 40 (step 114) depicted in FIG. 9.
In accordance with conventional brazing procedures, flux and braze rings are first fitted onto the several fittings and the small tube where each of these component parts is fitted into the corresponding hole in the main body. This step is represented by the reference numeral 116 in FIG. 9. With the various components having been so assembled according to step 116, the brazing operation 118 is next conducted whereby the fittings and tube are joined to the partially formed main body by leak-proof joints.
In order to assure the successful completion of the brazing operation it is desirable to conduct a leakage test, on the joined parts in the condition represented by FIG. 4 (step 120). The leak test serves to prove the leak-proof joints of the locations of brazing. Thus after the performance of the leak test, the partially completed assembly has the form represented in FIG. 4.
Since the small tube 40 is intended to form the outlet connection of the desiccant assembly, a suitable means of connection is next created. This includes the steps of installing a nut 58 onto the exposed end of tube 40 (step 122), swaging the end of the tube at 62 to retain the nut thereon (step 124), moving the nut into engagement with the swage and then staking (numeral 64) the nut in place (step 126). It is to be appreciated that both the inlet fitting 42 and the outlet connection are suitably constructed so that when connections are made of the completed desiccant assembly into a refrigeration circuit, the connections form leakproof joints through which refrigerant is conducted into and out of the assembly. At this point a further de-greasing step 128 is performed.
The next steps in the fabrication process are described with reference to FIG. 6. An annular screen assembly 66 is inserted via the open end of the container onto tube 40. Screen assembly 66 has an ID which allows it to fit closely around tube 40 and to be disposed against the inside of end wall 26. FIG. 6 shows the final installed position of the screen assembly.
The screen assembly comprises a frame containing mesh screen elements 68, and the purpose of the screen assembly is to screen any contaminating material which may be in the system from potentially plugging the bleed orifice or orifices 52.
Next the desiccant element 70 is inserted into the container via the open end thereof. The illustrated configuration for the desiccant element comprises molecular sieve desiccant firmly contained in a polyester felt bag which fits with substantial conformity to the annular internal space surrounding tube 40 and screen assembly 66. FIG. 6 also shows the use of a retainer 72 which is associated with the desiccant bag to assist in holding the shape and placement.
The last element to be assembled into the container via the open end thereof is a baffle 74 which fits onto the upper end of tube 40. The purpose of the baffle is to shroud, but not block, the open upper end of tube 40 in the manner shown whereby fluid flow entering the inlet fitting 42 is caused to pass downwardly along the inside of the sidewall of the container and through the desiccant.
With the components 66, 70, 72 and 74 having been assembled into the open end of the container, as represented by 130 in FIG. 9, the next operation performed comprises friction spinning the open upper end of the sidewall of the tube stock to form the fully closed end wall 76 (step 132). Preferably end wall 76 is formed in the manner described earlier so that the best possible degree of closure is obtained. Because the components assembled to the container prior to spin forming of end wall 76 are substantially symmetrical about axis 24, the assembly can be suitably chucked on the spindle of a friction spinning machine and rotated with minimum imbalance. The fittings 42, 44, 46 are spaced from end wall 76 so as not to interfere with the friction spinning process forming that end wall.
FIGS. 7 and 8 illustrate the finished form of the desiccant assembly, and it can be seen that the tube 40 has been externally bent into a particular configuration subsequent to friction spinning of end wall 76. This is represented by the step 134 in FIG. 9. Consequently the completed assembly has been adapted for use in a particular installation so that connection of refrigerant lines to the inlet and outlet fittings can be conveniently performed. Although not shown, suitable provisions may be associated with the assembly for mounting it, such as through use of a bracket in the engine compartment of an automobile for air conditioning system usage.
Additional finishing procedures include the assembly of valves (not shown) into the fittings 44 and 46. Protective caps 43, 47, 60 are put over the various fittings until such time as the desiccant assembly is installed in a system, at which time these protective caps are removed.
Based upon the foregoing description it can be seen that the resulting construction has the container of a one piece unitary construction. There is no seam between two separate container parts as in the prior art. The invention provides significant improvements in fabrication and in reliability making the invention of meaningful cost-effectiveness. The illustrated embodiment 20 is referred to as an external tube version because a portion of tube 40 extends from the exterior as shown in FIGS. 7 and 8. It is possible to practice principles of the invention in an internal tube version and an example of such a version is described with reference to FIGS. 10-14.
The version 200 of FIGS. 10-14 comprises many of the same basic parts as the external tube version 20 and like reference numerals are used to identify these parts even though there may be some minor differences in appearance. A detailed description will therefore not be repeated.
One principal difference in the embodiment of FIGS. 10-14 is that the tube 202 is contained essentially entirely internally of the container. The tube is shown by itself in FIG. 13, and its shape can be perceived from that Figure and FIG. 10. The tube has a U-shaped bend at the bottom. The bleed hole 52 is provided at that bend and enveloped by the screen assembly 66. The version 200 enables the desiccant element 70 to be trapped by the tube itself so that a separate retainer structure may be omitted. The steps involved in the method are described with reference to FIG. 14.
The initial steps 300, 301, 302 in forming the main body are the same as described for the first version, namely cutting tube stock to length, de-greasing, and then friction spinning one end of the cut length of tube stock to form end wall 26 and sidewall 28. In this instance the end wall is fully closed and it remains so.
The small tube 202 is formed by conventional forming techniques into the illustrated configuration in a series of steps. These include cutting small tube stock to length (step 292), bending the cut tube into the desired curved shape (step 294), drilling or piercing the bleed hole, or holes (step 296), and de-greasing (step 298).
After the performance of step 302 on the large tube stock to form the one end wall 26, the step 304 of punching holes and coining flats is performed. The internal tube version 200 which has been illustrated does not use any end wall holes, but rather retains the three sidewall holes previously described for the external tube version 20 and includes a fourth hole 204 in the sidewall diametrically opposite hole 32 for a further fitting 207 to provide for the outlet connection. After step 304, a de-greasing step 306 is performed.
This is followed by assembling the fittings, flux and braze rings onto the body (step 308) and then brazing (step 310) whereby the various fittings 42, 44, 46, 207 are joined to the container body in a leakproof manner. Next a leak test is performed (step 312) to check the braze.
After performance of step 312, the desiccant element 70, and the formed tube 202, including screen 66 installed thereon, are assembled into the interior of the container via the open end thereof (step 314). The desiccant assembly is first inserted followed by the tube 202. The U-shaped bend of the tube fits between what may be considered as two halves of the desiccant bag, and in the final assembled position shown in FIG. 10, the tube holds the bag in place at the bottom of the inside of the container.
The shape of the tube is such that it can be manipulated so that the outlet end 206 can pass through hole 204 and be swaged into fitting 207. In the final position the inlet end 208 is disposed generally coaxial with axis 24.
Next the baffle 74 is inserted into the open upper end of the container to fit onto the inlet end 208 of tube 202 (step 316). Once again the baffle does not obstruct the inlet end of the tube but rather serves to shed downwardly refrigerant which enters the container via the inlet fitting so that the refrigerant will pass through the desiccant element.
The open end of the container is next closed by chucking the assembly in a suitable manner on the spindle of a spinning machine and friction spinning the open end of the tube stock to form the other closed end wall 74 (step 318).
The completed assembly 200, is shown in FIGS. 11 and 12, including the additional steps, after the formation of end wall 76, of the insertion of valves (not shown) into the fittings 44 and 46 and the placement of protective caps 43, 47, 60 onto the fittings for subsequent removal when the desiccant assembly is installed for its intended use in a refrigerant circuit.
The internal tube version has the same advantages as the external tube version in that the container body is of a one piece unitary construction. Hence it too is a cost effective improvement over the prior procedures for making this general type of product.
Although the drawing Figures have disclosed representative embodiments and the block diagrams of FIGS. 9 and 14 have portrayed representative steps, it is to be appreciated that these are merely exemplary of principles of the invention and that various other modes of practicing the invention are contemplated.
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A method of manufacturing a desiccant assembly for a refrigeration circuit of the type used in automotive air conditioning systems. The method includes performing a container body by cutting a piece of seamless tube stock and friction forming one end of the tube to form an end wall. One or more apertures are formed within the container body to accommodate refrigerant circuit fittings. A refrigerant tube is installed in the container body along with associated components such as the desiccant material, additional fittings etc. Thereafter, the container body is again friction formed to enclose the opposite end wall of the container. The method according to this invention avoids the disadvantages associated with a multi-piece desiccant container which is subject to refrigerant leakage.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a liquid fuel storage device including a fuel tank and a canister for use with a vehicle.
2. Description of Related Art
In order to fill-up a fuel tank with fuel smoothly, it is necessary that fuel vapor in the fuel tank be instantly emitted to the outside of the fuel tank to enable the fuel vapor to be replaced with the fuel without resistance. Further, since the fuel is vigorously ejected from a fuel gun inserted into a fuel port of the fuel tank in refueling, a lot of fuel mist is produced. Since the emission of fuel vapor and mist (hereinafter, referred to as "fuel gas") to the atmosphere causes an environmental problem, the fuel gas is generally introduced to a canister and adsorbed and captured thereby as in U.S. Pat. No. 5,090,459.
When refueling is necessary, since a fuel tank is usually almost entirely filled with a fuel gas, a large canister must be designed, taking the capacity of the fuel tank into consideration.
However, a large canister is not preferable to satisfy a trade-off request to increase the capacity of a fuel tank as well as the space in a vehicle.
To cope with this problem, a liquid fuel storage device for a vehicle has been proposed having a mechanism for inflating and deflating an air bag disposed in a tank according to a surplus space produced by an amount of storage fuel. This type of storage device has been disclosed, for example, in Japanese Patent Unexamined Publication No. 64-16426 (1989) wherein the space in a fuel tank filled with fuel gas (i.e., the space obtained by subtracting the amount of remaining fuel from the total capacity of the tank) can be reduced in refueling.
The fuel storage device arranged as described above usually requires pressurizing means (a pressurizing pump or the like) for pressurizing the air bag (by which the space occupied by the fuel storage unit as a whole is increased). Further, since the air bag communicates directly with the atmosphere to emit air in refueling, a fuel gas in the air bag which passes through an air bag film is simultaneously emitted.
SUMMARY OF THE INVENTION
In view of the above problem, an object of the present invention is to provide a liquid fuel storage device including a mechanism for inflating and deflating an air bag disposed in a fuel tank according to an amount of stored fuel, the liquid fuel storage device being arranged such that it does not need pressurizing means and does not raise the possibility of a fuel gas passing though the air bag being emitted to the atmosphere simultaneously with the emission of air to the atmosphere.
To solve the above problem, in accordance with the present invention, a liquid fuel storage device is provided which comprising:
a fuel tank;
a canister for absorbing fuel vapor as the fuel tank is refilled with fuel;
an air bag disposed in the fuel tank and constructed and arranged to inflate to occupy a space in the fuel tank according an amount of remaining fuel;
piping structure communicating the fuel tank with the engine for inflating the bag by reducing the pressure in the fuel tank;
an air introduction pipe communicating with the atmosphere and provided with a first valve mechanism for introducing air into the air bag and preventing air from flowing out of the air bag after the air bag is inflated; and
an air emission pipe provided with a second valve mechanism which is opened only in refueling to emit the air in the air bag in refueling and which is connected to the canister.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a system schematic diagram showing a liquid fuel storage device according to the present invention after an air bag is inflated; and
FIG. 2 is the system schematic diagram of FIG. 1 shown during refueling.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described below in detail with reference to an embodiment shown in FIGS. 1 and 2.
The liquid fuel storage device of the invention includes a fuel tank 12 and a canister 14.
Although the present invention is described with reference to a liquid fuel storage device provided with a mechanism for keeping an interior of a fuel tank at a predetermined, reduced pressure state for a predetermined time when an engine starts, so as to check for abnormal leakage of the fuel tank, the present invention is not limited thereto. Note, the fuel tank leakage check mechanism is one of the mechanisms developed for an on-board-diagnosis system established by the United States Government for controlling air pollution generated by vehicles. The system will be described below in detail.
A fuel tank 12 having a fuel filler pipe 16 stores liquid fuel 18 and feeds the fuel 18 to the engine of a vehicle (not shown). The fuel filler pipe 16 includes a filler neck 22 provided with a fuel cap 20. A seal member 26 provided with a trap door 24 and a protective cylindrical member 28 for protecting the seal member 26 are attached to the filler neck 22. Further, a bleeder pipe 30 serving as a bleeder port in refueling is disposed in the vicinity of the extreme end of the fuel filler pipe 16 above the upper wall of the fuel tank 12 and a fuel shut-off valve 34 to which a float 32 is assembled is disposed at position apart from the extreme end of the fuel filler pipe 16, respectively. A baffle 38 for preventing an abrupt back flow of the liquid fuel in the fuel tank 12 is attached to the downstream end of the fuel filler pipe 16. Note, numeral 39 denotes a fuel return pipe.
A canister 14 temporarily adsorbs and captures fuel gas produced in the fuel tank 12. An air inlet port 14a is formed at a bottom the canister 14 and is connected to an air cleaner 44 through an air inlet pipe 42, provided with a two-position switching valve (solenoid operation type) 40. The two-position switching valve 40 is opened and closed in response to a signal (electric signal) sent by an engine controller unit (hereinafter, abbreviated as "ECU").
A fuel gas emission port 14b and a fuel gas introduction port 14c are formed at an upper wall of the canister 14. The fuel gas emission port 14b is connected to an air inlet pipe 48 through a fuel gas emission pipe 46 provided with a flow rate/pressure reduction control valve (electromagnetic valve) 45. The air inlet pipe 48 defines a reduced pressure generation chamber communicating with the engine. The flow rate/pressure reduction control valve 45 has two roles: (a) it controls a flow rate of fuel gas separated from the canister 14; and (b) it controls pressure in the fuel tank in such a manner that the control valve 45 is opened and closed in response to a sensing signal from a pressure sensor 50 attached to an inside of the seal member 26 of the filler neck 22 by a signal sent from the ECU 62, in order to check for leakage of the fuel tank 12.
The fuel tank 12 and the fuel gas introduction port 14c of the canister 14 are connected to the fuel shut-off valve 34 of the fuel tank 12 through a fuel vapor pipe 66 provided with a positive/negative pressure control valve (spring-biased two-way valve) 64. A gas introduction valve (electromagnetic valve) 68 is connected to the fuel vapor pipe 66 in parallel with the positive/negative pressure control valve 64. The gas introduction pipe 68 is also opened and closed in response to a signal sent from the ECU 62 (opened when the engine is in operation).
The bleeder pipe 30 of the fuel tank 12 is connected to the fuel introduction port 14c of the canister 14 through a bleeder pipe 72 provided with a gas shut-off valve 70 which is normally closed and only opened during refueling. Since only one fuel gas introduction port 14c is provided with the canister 14 in the illustrated example, the port 14c joins the fuel vapor pipe 66 on the canister 14 side. However, two sets of fuel gas introduction ports may be provided and connected to completely different pipes.
The gas shut-off valve 70 may be of any construction, in the illustrated embodiment, the valve 70 is opened and closed in such a manner that a valve plug driving lever 76, which is biased in a valve plug closing direction by a circular cam 74 fixed to the rotary shaft 24a of the trap door 24, moves a seal valve plug 78 upwardly and downwardly. In the illustrated embodiment, numeral 77 denotes a coil spring for easing the bias and impact on the seal valve plug 76.
In the illustrated embodiment, the gas shut-off valve 70 is provided with a fuel check valve 82 accommodating a float 80 so that fuel does not flow out to the canister 14 when the vehicle turns sideways, or the like.
In the liquid fuel storage device arranged as described above, the embodiment is characterized in the following arrangement.
The storage device includes an air bag 36 disposed in the fuel tank 12, the pressure reduction pipe (fuel vapor pipe) 66 for reducing pressure in the fuel tank 12 to inflate the air bag 36, an air introduction pipe 84 communicating with the atmosphere to introduce air into the air bag 36, and an air emission pipe 86 for emitting the air in the air bag only during refueling.
The air bag 36 is preferably made of a resin film of polyvinyl fluoride, polyamide, polyethylene, polyvinyl chloride etc. A synthetic fiber cloth of polyamide, polyester etc. having a resistance to fuel, with the inside thereof coated with fuel resistant rubber may also be used.
In this embodiment, the pressure reduction pipe need not be provided, since the aforesaid fuel vapor pipe 66 can serve as the pressure reduction pipe.
The air introduction pipe 84 is connected to the air inlet pipe 42 between the air cleaner 44 and the two-position switching valve 40. The air inlet pipe 84 is provided with a valve mechanism for preventing the air bag 36 to be deflated after the air bag has been inflated. The valve mechanism is in the form of a spring-biased one way valve (check valve) 88.
The air emission pipe 86 is connected to the bleeder pipe 72 through an air emission valve 78b, wherein a seal valve plug 78, a bleeder valve plug 78a and an air emission valve plug 78b of the shut-off valve 70 connected to the bleeder pipe 72 are formed in parallel with each other on a single valve sheet 79.
As described above, although the gas shut-off valve 70 is mechanically opened and closed by the circular cam 74 associated with the rotary shaft 24a of the trap door 24, the gas shut-off valve 70 is not particularly limited to this arrangement and may be opened and closed by an electromagnetic mechanism or the like.
Next, operation of the embodiment will be described.
When the engine is started, the two-position switching valve 40 in the air inlet pipe 42 of the canister 14 is closed in response to a signal sent from the ECU 62, the flow rate/pressure reduction control valve 45 communicating with the fuel gas pipe 46 is opened, and the gas introduction pipe 68 disposed in the fuel vapor pipe 66 connecting the fuel gas introduction port 14c of the canister 14 to the fuel shut-off valve 34 of the fuel tank 12, is opened. As a result, the air inlet pipe 48 exposed to a reduced pressure is caused to communicate with the fuel tank 12 so that the pressure in the fuel tank 12 is reduced (lower than the atmospheric pressure) defining a reduced pressure state. When the ECU 62 receives a sensing signal from the pressure sensor 50 to check the presence of abnormal leakage of the fuel tank 62, the ECU 62 controls the reduced pressure state by inputting a command signal to the flow rate/pressure reduction control valve 45 as well as determines a change of the reduced pressure state for a predetermined time, and when leakage arises, the ECU 62 issues warning through a warning lamp or the like.
Since the reduced pressure state in the fuel tank 12 is maintained for a predetermined time as described above, the air bag 36 will inflate so that pressure in the air bag 36 is also reduced. Thus, the one-way valve 88 is automatically opened against a spring force so that the atmosphere flows into the air bag 36 through the air cleaner 44 to inflate the air bag 36 according to an amount of remaining fuel in the fuel tank.
Then, after the reduced pressure state is maintained for a predetermined time, that is, in response to a signal sent from the ECU 62 which indicates that the predetermined time has elapsed after starting the engine, the two-position switching valve 40 in the air inlet pipe 42 is opened. Thus, the air inlet pipe 42 communicates with the air inlet pipe 48 so that the pressure in the air introduction pipe 84 for the air bag 36 connected to the air inlet pipe 42 is also reduced. As a result, in the air introduction pipe 84, the one-way valve 88 is also automatically closed by a spring force due to the above reduced pressure state, and even if fuel gas is produced while the vehicle travels, parks or stops (except a time of refueling) and the pressure in the fuel tank 12 is made positive, air in the air bag 36 does not escape. Naturally, the gas shut-off valve 70 of the air emission pipe 86 communicating with the air bag 36 is closed (refer to FIG. 1).
When fuel is consumed as the vehicle travels and a space is created in the fuel tank 12 to permit the air bag 36 to inflate, the air bag is inflated by a pressure difference between the inside and the outside of the air bag 36 each time the engine is started and the space in the fuel tank 12 in which fuel can evaporate, is greatly reduced. When fuel violently evaporates and the pressure in the tank is increased excessively, a positive/negative pressure control valve 64 in the fuel vapor pipe 66 is operated and fuel vapor is emitted into the canister 14 through the fuel gas introduction port 14c and adsorbed and captured by the canister 14.
Next, when the fuel cap 20 is removed for refueling and a fuel gun 90 is inserted into the fuel filler 16, the protective cylindrical member 28 advances to push and open the trap door 24. At this time, since the circular cam 74 is rotated in association with the rotation of the rotary shaft 24a of the trap door 24, the valve plug driving lever 76 lifts the seal valve plug 78 upwardly through locking means by the long diameter portion of the circular cam 74. Therefore, the bleeder valve plug 78a and the air emission valve plug 78b are in open positions and the fuel tank 12 and the air bag 36 are caused to communicate with the canister 14 through the bleeder pipe 72 (refer to FIG. 2).
When refueling is started, fuel vapor in the fuel tank 12 and mist produced in refueling are introduced into the canister 14 through the bleeder pipe 30, the shut-off valve, in an open state, and the bleeder pipe 72. On the other hand, the air bag 36 is deflated by a refueling pressure and air in the air bag 36 is introduced into the canister 14 through the air emission pipe 86, the gas shut-off valve 70 and the bleeder pipe 72.
Consequently, even if air in the air bag 36 is mixed with fuel gas, since the fuel gas is introduced into the canister 14 and adsorbed and captured by the canister 14, the emission of fuel gas into the atmosphere can be minimized.
Since the liquid fuel storage device according to the present invention is arranged as described above, the device achieves the following meritorious effects.
Since the air bag is inflated in such a manner that pressure in the fuel tank is reduced by making use of the pressure reduction pipe through which the fuel tank is connected to the pressure reduction chamber and the engine, a special pressurizing unit is not required.
The fuel vapor pipe for connecting the fuel tank to the canister can be used as the pressure reduction pipe and the bleeder pipe connected to the canister can be used as the air emission pipe for emitting air in the air bag during refueling. Consequently, when the fuel storage unit is mounted on a vehicle, any additional space is not fully occupied.
Since the valve mechanism, opened only during refueling is provided and air in the air bag is emitted during refueling through the air emission pipe connected to the canister, fuel gas passing through the air bag is captured by the canister. Thus, there is not a possibility that fuel gas is emitted to the atmosphere when air is emitted from the air bag.
The size of the canister can be reduced by the reduction of an amount of fuel gas in the fuel tank.
While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiment, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.
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A liquid fuel storage device is provided for use with an automobile system including an engine, a fuel tank, and a canister for absorbing fuel vapor during refueling. The device includes an air bag disposed in the fuel tank and constructed and arranged to inflate to occupy a space in the fuel tank in accordance with an amount fuel remaining in the fuel tank. Piping structure communicates the fuel tank with the engine for inflating the air bag by reducing pressure in the fuel tank when the engine is started. An air introduction pipe communicates with the atmosphere and includes a first valve mechanism for introducing air into the air bag and prevents air from escaping from the air bag after inflation thereof. An air emission pipe includes a second valve mechanism, which is opened only in refueling to emit air in the air bag during refueling. The air emission pipe is connected to the canister.
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BACKGROUND OF THE INVENTION
[0001] The invention relates to a method of infrared-optically determining the concentration of at least one analyte in a liquid sample, wherein the infrared absorption of the analyte is measured and compared with a standard.
[0002] The invention further relates to a device for the infrared-optical transmission determination of the concentration of at least one analyte in a liquid sample, with a sample cuvette filled with the sample liquid, the sample cuvette being arranged in the radiation path between a radiation source for providing the infrared radiation and a detector for measuring the infrared absorption induced by the analyte in the sample cuvette.
[0003] Moreover, the invention relates to the use of such an arrangement for the infrared-optical transmission determination of the concentration of at least one analyte in a liquid sample.
[0004] The detection or measurement of concentration of substances in a sample is performed in many scientific and technological fields, e.g. chemistry, process technology, production technology, medical technology, environmental analytics, and food analytics, by means of absorption spectra. The infrared spectrum is particularly suitable, since precisely in this range many analytes have characteristic absorption bands from the intensity of which the analyte concentration can be determined.
[0005] GB 1 521 085 A discloses a detector for an infrared analyzer, which serves to determine the concentration of a certain component in a liquid or gaseous sample. A filter that passes infrared radiation of a single narrow wavelength range is placed between the sample cuvette and the radiation source. A wavelength range is chosen which is absorbed by the substance to be analyzed. By the difference between the absorption spectra of the sample with analyte and the sample without analyte, the presence as well as the concentration of the analyte in the sample can be determined. This described analyzer, however, requires a complicated arrangement, and the results obtained are not sufficiently specific.
[0006] WO 92/17767 relates to a method for quantitating fat in a fat-particle-containing emulsion by using infrared absorption techniques, wherein the absorption peak at a wavenumber of approximately 1160-1190 cm −1 is used for determining the fat concentration.
[0007] AT 404,514 B describes a further arrangement for measuring analytes in a liquid sample by infrared absorption. Before the measurement, the analyte to be measured is subjected to a chemical reaction which leaves all the remaining components of the liquid sample unaffected, and the change in the infrared absorption caused by the chemical reaction with the analyte is measured as a function of the analyte concentration to be determined. This chemical reaction is, e.g., a change of the pH, so that the substance to be analyzed is present in a certain form before the pH change, such as a single-charged substrate or an uncharged phosphoric acid which is non-absorbing or only slightly absorbing at the wavelength indicated. After the pH change, the analyte is present in a form, e.g. triple-charged phosphate, which has an absorption maximum at the wavelength indicated. From the difference of measurement before and after the chemical reaction, the presence and the concentration of the analyte can be determined. To produce light with a certain wavelength, a filter that passes infrared radiation of a single narrow wavelength range is placed between the sample cuvette and the source of radiation. This method is simple and rapid, yet in view of the described chemical reaction, includes difficulties as regards the sensitivity and robustness of the analyzer.
[0008] It also is known in the art that a selective concentration determination of glucose in complex mixtures such as human serum, is possible by absorption measurement at a few wavelengths in the middle region of the infrared spectrum, as described by Heise et al. in Fresenius J. Anal. Chem. (1997), 359, 93-99. Absorption spectra in the middle of the infrared spectrum were taken on blood plasma and whole blood samples using a Fourier Transform Infrared (FT-IR) spectrometer. Heise et al. also disclosed a chemometric model for the determination of glucose in unknown samples, where a few wavelengths were sufficient to obtain results equal to, or better than, results obtained by means of a PLS (partial least square) model covering the entire (1200-950 cm −1 ) spectral range. A drawback of this method is, however, that the FT-IR spectrometer is not handy and is heavy and the employed measurement on the surface of a toxic ZnSe crystal is not usable for on-line determinations of biological samples in so far as the samples, due to the contact with the toxic ZnSe crystal, also become toxic after the determination. Moreover, there are potential problems with the absorption of proteins on the surface, and, lastly, transmission measurements in practice cannot be made since the FT-IR spectrometer, which has a low light intensity, only allows for the use of layers only up to 50 micrometers thick. Such layer thicknesses, however, are not suitable particularly when determining the concentration in biological samples, since within a short time the thin layer will be clogged or the sample (e.g. whole blood) will be damaged, whereby an on-line measurement, e.g. on the living patient, with a return of the sample to the patient becomes life-threatening and thus completely impossible.
[0009] In general, conventional radiation sources for producing infrared radiation are based on thermic radiators and accordingly are limited in their radiation power. Thus, the radiation power emitted by a thermic radiator of 1500 K in the narrow spectral range of from 9.9 to 10.1 cm −1 is less than 0.2% of the entire radiation power emitted. Due to the practical difficulties of efficiently collecting emitted radiation, only a small fraction of the emitted radiation is actually available for the measurement. For example, a state of the art spectrometer from Bruker GmbH, the radiation power distributed over the entire region of the spectrum and finally available in the sample chamber is only approximately 25 mW. The consequence thereof is that in the narrow wavelength range from 9.9 to 10.1 cm −1 , only low power, approximately 50 μW, is available. With respect to the thermic radiator as disclosed in AT 404,514, it is estimated that the usable power is only in the range of approximately 10 μW.
SUMMARY OF THE INVENTION
[0010] Thus, it is an object of the present invention to provide a method as well as an arrangement for the infrared-optic transmission determination of the concentration of an analyte in a liquid sample, which can be carried out easily and rapidly, has a sufficient sensitivity and robustness so as to afford a marketable product, and which, in particular, is suitable for on-line measurement of biological samples where the sample is returned to the patient.
[0011] The method is characterized in that the liquid sample is irradiated with infrared radiation of high light density, wherein the infrared radiation has a sharp intensity peak at at least one wavelength.
[0012] Such infrared radiation with a high power density is produced with a laser, wherein, due to the high spectral density and the sharp intensity peaks with lasers, spectroscopic methods are possible, which cannot be carried out with conventional radiation sources. The combination of the [infrared] spectroscopy with laser spectroscopy results in a method for infrared-optic transmission determination of analytes in a liquid sample, which has a markedly higher sensitivity, flexibility and robustness than conventional methods.
[0013] With the method according to the invention, concentrations of ions as well as any other substances, such as organic acids, in particular fatty acids, alcohols, carbohydrates, in particular glucose, proteins, urea etc. can be measured with high precision.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] [0014]FIG. 1 schematically illustrates an arrangement wherein the preceding modulation is a raising of the pH of the sample;
[0015] [0015]FIG. 2 a shows the absorption spectrum of PO 4 3− and H 2 PO 4 − ;
[0016] [0016]FIG. 2 b shows the emission spectrum of a quantum cascade laser;
[0017] [0017]FIG. 3 shows the voltage-time diagram corresponding to FIG. 2 a;
[0018] [0018]FIG. 4 shows the absorption spectrum of EDTA and EDTA+Ca 2+ ;
[0019] [0019]FIG. 5 shows the absorption spectrum of pure glucose and of glucose in the glucose-borax complex; and
[0020] [0020]FIG. 6 shows the emission spectra of two quantum cascade lasers.
[0021] [0021]FIGS. 7, 8 and 9 show absorption spectra as obtained in the inventive determination of free fatty acids.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0022] The present invention will be explained in more detail by way of reference to the figures illustrated in the drawings.
[0023] In FIG. 1, an arrangement for the infrared-optical determination of an analyte in a liquid sample by means of a quantum cascade laser (QCL) is illustrated. In this instance, the detection is preceded by a modulation of the analyte, phosphate, i.e. a pH change. The sample is supplied to the detector QCL at a rate of 3.4 ml/min. Upstream of the detector, either a buffer having a pH of 5, or a soda lye having a pH of 13, is mixed with the sample, depending on the valve position.
[0024] In FIG. 2 a it can be seen that the absorption spectrum changes according to the change of the pH. The black bar characterizes the intensity peaks produced by the quantum cascade laser used (see also FIG. 2 b ). Up to approximately 20 seconds (pH=5), the analyte is present as H 2 PO 4 − . From about 30 seconds to about 60 seconds, the analyte is present as PO 4 3− (pH=13). At a pH of 5, less radiation is absorbed, while at a pH of 13, clearly more radiation is absorbed so that a peak forms in this range. Subsequently (after 60 sec), the pH is lowered to pH=5 again, so that the analyte absorbs the radiation to a lesser extent.
[0025] In FIG. 3, the voltage-time diagram corresponding to FIG. 2 a is shown. If less radiation is absorbed (pH=5), a maximum voltage of more than 0.0115 V is measured. If the pH is raised to 13 so that the analyte will absorb the radiation to a higher degree, the voltage measured will fall to a minimum of below 0.01 V. Gradually, the pH was changed so that the periodic curve illustrated in FIG. 3 was formed.
[0026] In FIG. 4, two infrared absorption spectra are illustrated. The absorption measurement can be preceded by a chelating procedure (the absorption spectrum of both the chelation complex EDTA-CA 2+ and of the EDTA without Ca 2+ has been illustrated). The differences in peak heights can be precisely determined by means of the quantum cascade laser.
[0027] [0027]FIG. 5 also shows two absorption spectra, the modulation preceding detection being a complexing of glucose with borax. The spectrum of pure glucose has other peak intensities than the spectrum of the glucose in the glucose-borax complex, this being precisely measurable when using a quantum cascade laser.
[0028] [0028]FIG. 6 shows two emission spectra produced by different quantum cascade lasers A, B. It can be seen that the wavelengths each had sharp intensity peaks, the wavelengths differing by a wavenumber of approximately 1 (0.01 μm). (When using a quantum cascade laser, the peaks are clearly visible, and the measurement becomes sensitive).
[0029] [0029]FIG. 7 shows the absorption spectra of a fatty acid ester (butyl stearate) and a free fatty acid (oleic acid) in n-propanol. It can be clearly recognized that the bands of the —C═O stretch oscillation of the two molecules overlap. For a precise determination of the free fatty acid in edible oils which mainly consist of fatty acid esters and secondary components, such as C═O containing compounds like aldehydes and ketones, it is necessary to selectively modulate the absorption spectrum of the free fatty acids.
[0030] [0030]FIG. 8 shows that by adding KOH/n-propanol, the spectrum of the fatty acid ester remains practically unchanged, whereas the spectrum of the free fatty acids changes clearly—the asymmetric stretch oscillation of the carboxylate ion formed is clearly recognizable at 1570 cm −1 and the symmetrical stretch oscillation at 1400 cm −1 . By measuring the infrared absorption of the modulated fatty acid ester spectrum, preferably at 1570 wavenumbers alone or relative to the absorption at 1612 wavenumbers, respectively, with a quantum cascade laser, a precise measurement of the free fatty acid content of edible oils becomes possible.
[0031] In FIG. 9, a practical example is shown; here, the free fatty acid content of a commercially available edible oil, sold under the trademark Mazola® was determined.
[0032] When talking about a “high light density” in the present description, it is meant a spectral power density higher by orders of magnitude than can be attained with conventional thermic radiators, in particular a spectral power density in the range of 10 −5 W/cm −1 and more, preferably in the range of 10 −3 W/cm −1 and more.
[0033] Such infrared radiation with a high power density is produced with a laser, wherein, due to the high spectral density and the sharp intensity peaks with lasers, spectroscopic methods are possible, which cannot be carried out with conventional radiation sources. The combination of infrared spectroscopy with laser spectroscopy results in a method for infrared-optic transmission determination of analytes in a liquid sample, which has a markedly higher sensitivity, flexibility and robustness than conventional methods.
[0034] The inventive method may be used to determine concentrations of ions as well as other substances, including organic acids, particularly fatty acids; alcohols; carbohydrates, particularly glucose; proteins; urea; and the like can be measured with high precision.
[0035] In phosphate-containing beverages, such as Coca Cola, the pH varies between 2.5 and 3. Thus, in such solutions, both H 2 PO 4 − (mostly more than 80%) and H 3 PO 4 are present. For the direct determination of the entire amount of phosphoric acid, thus, the measurement of both molecules is necessary. This is achieved by measurement of the infrared absorption in several sharp spectral regions, preferably at 1103 cm −1 , 1078 cm −1 , 1058 cm −1 (H 2 PO 4 − ), 1014 cm −1 and 975 cm −1 (H 3 PO 4 ). The aim of choosing the sharp wavelength regions is to measure the absorption maximums of H 2 PO 4 − (1078 cm −1 ) as well as H 3 PO 4 (1014 cm −1 ) relative to baseline points (1103 cm −1 , 1058 cm −1 and 975 cm −1 ) so that the determination of the total amount of phosphoric acid will not be disturbed by further components such as sodium cyclamate (absorption maximum at 1038 cm −1 ) as well as sugar die (absorption maximum at 1042 cm −1 ) or also a variable water absorption by a change of the pH.
[0036] Preferably, the analyte to be measured is additionally subjected to a modulation prior to or during the measurement, wherein changes of the infrared absorption caused by the modulation of the analyte are measured as a function of the analyte concentration to be measured.
[0037] By “modulation,” any change of the absorption of the sample or of the analyte, is to be understood, such as a chemical reaction or a separation of the sample, respectively, e.g. by means of a chromatographic method. A chemical reaction is, e.g., a change of the pH of the liquid sample so that after the chemical reaction, the analyte will be present in a different form in which it has a characteristic absorption spectrum. For instance, in the concentration determination of phosphate which in the acid region is almost exclusively present in the forms H 2 PO 4 − and H 3 PO 4 (single-charged phosphate or uncharged phosphoric acid), the pH is raised from an acid pH to a pH of more than 13 so that phosphate is almost exclusively present in the triple-charged form. Similarly, the pH can be raised to 9 to 11 so that the phosphate is almost exclusively present in the double-charged form. In the triple-charged form, phosphate has an absorption maximum at a wavenumber of 1005 cm −1 , and in the double-charged form, the phosphate has an absorption maximum of 1080 cm −1 .
[0038] The term “modulation” also comprehends chelation, wherein the analyte forms a chelation complex with the admixed reagent, the infrared absorption of the complex being measured so that the concentration of the analyte can be precisely determined. In the complexing reaction, EDTA (ethylene diamine tetra-acetic acid)-Ca 2+ -complex or glucose-borax-complex may be used, to mention but two examples. The advantage of such complexing lies in that in a sample comprising alcohols in addition to sugar, low sugar contents can be precisely measured in the presence of high alcohol concentrations by complexing, whereas in a direct, simple infrared-optical determination of the sample, the sugars and the alcohols cannot be determined side by side since the absorption spectra will overlap, as depicted in FIG. 7.
[0039] For further possibilities of the technique of modulation, reference is made to the publication by J. Ruzicka “The second coming of flow-injection analysis” (Analytica Chemica Acta, 261 (1992) 3-10).
[0040] The term “modulation” also includes the chromatographic separation of sample on a chromatographic column. In this instance, the liquid sample comprising the analyte is chromatographically separated, whereupon the separated sample, when leaving the column, is irradiated with infrared radiation of high light density, the infrared radiation having at least one sharp intensity peak. Each analyte absorbs radiation at a defined wavelength so that the absorption of this determined peak can also be quantitated in case of an incomplete separation.
[0041] Furthermore, “modulation” can also mean an interaction between a biological sample (e.g. protein solution, DNA solution, cell cultures etc.) and a certain active substance of a medicament, wherein a possible interaction between the biological sample and the active substance necessarily will be associated with a change of the concentration of the free active substance and a change of the absorption spectrum of the biological sample, respectively.
[0042] With the above embodiments of the method of the invention it is, of course, possible also to measure other ions as well as any other substances, such as organic acids, alcohols, carbohydrates, etc., with high precision. The change of the pH will be carried out e.g. by the addition of lye or acid as well as with an ion exchanger. For further embodiments of this method of the infrared-optic determination by means of a chemical reaction, reference is made to the patent specification AT 404,514 B.
[0043] When using two or more infrared radiation sources of different wavelengths, the peaks of the respective analyte incompletely separated in chromatographic procedures can be precisely associated, since two or more traces will be taken up at different wavelengths and possible uncertainties in the association of the respective peak can be eliminated by comparing the traces (thus, different analytes can absorb in one trace, yet not in the other ones, and vice versa, cf. also
[0044] Preferably, the infrared radiation is produced by means of at least one laser. In this manner, the maximum light density and the best resolution can be obtained. The adjustments of the laser will depend on the desired wavelength range.
[0045] In principle, any type of laser can be used for producing infrared radiation, such as diode laser, dye laser, color center laser, to mention but a few examples. For the method according to the invention it is important that the lasers produce practically monochromatic light. This ensures that a spectrum having one or more sharp peaks with closely adjacent wavelengths is obtained in the desired wavelength range. If an analyte in the sample absorbs radiation at a very distinct wavelength, the concentration of this substance will clearly be detected even at a very low concentration.
[0046] Moreover, an advantage of lasers, in contrast to thermic radiators, is that lasers can be operated effectively by pulsing, thus resulting in a higher modulation depth will result.
[0047] In diode lasers, a current is sent through a p-n semiconductor diode in transmission direction so that electrons and holes will recombine in the region of the p-n transition. The end faces of the diode in most instances act as a resonant mirror. Diode lasers do not have a definite wavelength.
[0048] Color center lasers are solid lasers in which a crystal with color centers is used as the active medium. With various crystals they cover the entire range of the near infrared wave range of from 0.8 to 4 μm.
[0049] Dye lasers are lasers whose active medium consists of organic dyes dissolved in liquids. The dyes have wide emission bands.
[0050] A further suitable method of the present invention results in that when several lasers are used, the mean values of the respective intensity peaks of the infrared radiation differ from each other by about 50 wavenumbers. The lasers generate radiation, which is tunable in a range of approximately 40 to 50 wavenumbers. If two lasers are used which generate radiation whose wavelengths differ by 50 wavenumber, these two lasers will cover a range of approximately 100 wavenumbers. The more lasers used, the larger the wavenumber range that can be covered.
[0051] A particularly preferred embodiment is a method where several sharp intensity peaks in one laser emission spectrum differ from one another by about 1 wavenumber (0.01 micrometer). This difference allows for a highly specific determination of even minute amounts of an analyte, since the absorption of a single absorption band can be precisely detected and quantitated. Such emission spectra can only be produced with lasers. Conventional infrared light sources (i.e., thermic radiators with a filter), are only capable of producing wavelength ranges of approximately 20 wavenumbers, which ranges differ by approximately 20 to 50 cm −1 .
[0052] It is also suitable if the infrared radiation is produced by several lasers. Each laser has a specific emission spectrum, and it thus becomes possible to cover any desired wavelength range. The lasers to be used will be selected depending on which wavelengths are absorbed by the analytes to be determined.
[0053] Preferably, a method is used wherein the lasers are quantum cascade lasers. A quantum cascade laser is a semiconductor laser which uses only one type of carrier and which is based on the principle of quantum restriction. In a quantum cascade laser, the electrons make the transitions between restricted conditions in ultra-thin alternating layers of a semiconductor material. The emission wavelength then will depend on the thickness of the layers so that a wide spectrum of mean infrared wavelengths far into the remote infrared region can be produced, in particular between 3.5 and 17 μm. A particular advantage of the quantum cascade laser is the possibility of higher operating temperatures. The disadvantage of nearly all diode lasers is the high current density, which, when reached without cooling, would lead to a thermal breakdown. The efficiency of cooling in this zone restricts the discharge current and thus the light power of the diode laser. On the other hand, quantum cascade lasers may be used at and above room temperature, which, until now, had not been possible. Since the quantum cascade laser is based on a cascade of identical conditions (typically from 20 to 50), an electron will emit many photons so that a higher optical power will be emitted. A further advantage of the quantum cascade laser lies in its increased robustness. The foregoing advantages establish that the method according to the present invention for the infrared-optic determination of the concentration of at least one analyte in a liquid sample, wherein the infrared radiation is produced by means of a quantum cascade laser, is specific, rapidly feasible, and optimal for industrial application.
[0054] In any event, it is particularly advantageous if the lasers of the present invention are designed to be tunable, that is, the wavelength of the laser can be changed in a controlled manner. Use of a tunable laser in an infrared-optical determination makes the method much more flexible. In this manner it becomes possible to use a single device for determining all types of analytes, complexes, molecules etc., a device that can be adapted to a wide variety of chemical analyses. With diode lasers, the wavelength is tunable in a range that depends on the semiconductor material used, and the tuning is effected by changing the temperature and/or the discharge current. Tunable diode lasers deliver light in the near, middle, and far infrared between 0.8 and 32 μm.
[0055] The inventive arrangement is characterized in that at least one laser is provided as the radiation source for the infrared radiation, the laser produces a radiation of high light density, and the infrared radiation has a sharp intensity peak at one or more wavelengths. The arrangement can be constructed such that an on-line measurement, e.g. on a living patient with a return of the sample to the patient is possible. Thus, an arrangement is provided which has a simple structure and allows for a rapid and specific determination of analytes.
[0056] Preferably, in the arrangement according to the invention, furthermore the sample cuvette is preceded by a modulation device, or the sample cuvette includes a modulation device, in which the analyte can be influenced in a manner that changes its absorption behavior.
[0057] A particularly preferred arrangement is comprises at least one laser that is a quantum cascade laser, which produces infrared radiation having at least one sharp intensity peak. As has already been described above, this will allow for an extremely precise determination of analytes.
[0058] Advantageously, an embodiment of the present invention is characterized in that the at least one quantum cascade laser produces infrared radiation whose intensity peaks will differ by a wavenumber of approximately 1 (0.01 micrometer). This embodiment allows the precise measurement of the analyte, since a high light intensity in the range of the infrared absorption band of the analyte is attained.
[0059] A preferred embodiment is arrangement wherein, when several lasers are used, the mean values of the respective intensity peaks of the infrared radiation will differ from each other by a wavenumber of approximately 50.
[0060] Particularly preferred is an arrangement in which the laser(s) is (are) designed to be tunable.
[0061] Furthermore, the present invention relates to the use of a quantum cascade laser as an infrared radiation source for the infrared-optical determination of the concentration of at least one analyte in a liquid sample.
[0062] Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and illustrative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.
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A method of infrared-optically determining the concentration of at least one analyte in a liquid sample, wherein the infrared absorption of the analyte(s) is measured and compared with a standard, which is characterized in that the liquid sample is sampled with an infrared radiation of high light density, wherein the infrared radiation has a sharp intensity peak at at least one wave length, as well as an arrangement for the infrared-optical transmission determination of the concentration of at least one analyte in a liquid sample, with a sample cuvette flowed through by the sample liquid, the sample cuvette being arranged in the radiation path between a radiation source for providing the infrared radiation and a detector for measuring the infrared absorption induced by the analyte in the sample cuvette.
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[0001] This application claims benefit from U.S. provisional application Ser. No. 60/559,954 filed Apr. 7, 2004 which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] This invention relates to automobile components, in particular the invention relates to air filter assemblies for use with internal combustion engines and in particular, air filtration assemblies which serve multiple functions.
BACKGROUND OF THE INVENTION
[0003] Internal combustion engines require a source of clean air and accordingly, it is typical in automotive applications to provide a housing which contains a replaceable air filtration cartridge. Such assemblies are placed in the engine compartment where they can be conveniently ducted to the engine air inlet point. The space in the engine compartment under the hood is typically at a premium. Accordingly, it is desirable that the housing serve other functions where possible.
SUMMARY OF THE INVENTION
[0004] In accordance with the present invention, an automotive air filtration assembly comprises an air flow chamber portion and a liquid reservoir portion. The air flow chamber portion defines an air flow inlet for ambient air and an air flow outlet for supply of clean air to the engine. The air flow chamber portion defines a suitable slot for receiving a panel filter and includes means for providing replacement of the panel filter in connection with routine maintenance. The fluid reservoir portion includes a fluid filler conduit, a fluid chamber for holding fluid and a fluid outlet. Most conveniently, the fluid reservoir portion is utilized for storage of fluid such as windshield washer fluid. In accordance with an advantageous embodiment of the invention, the housing may also define a clip, the clip locating an additional liquid reservoir such as a power steering fluid reservoir.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] A better understanding of the invention may be had from reference to the attached figures which illustrate an air filter assembly in accordance with a first embodiment of the invention and in which:
[0006] FIG. 1 is a perspective view of the embodiment, and
[0007] FIG. 2 is an exploded perspective view of the embodiment of FIG. 1 .
DETAILED DESCRIPTION OF THE INVENTION
[0008] The air filter assembly, indicated generally at 10 , includes an air flow chamber portion 12 and a liquid reservoir portion 14 .
[0009] The air flow chamber portion 12 defines an air flow inlet 20 and an air flow outlet 22 ( FIG. 2 ). An air flow inlet snorkel 24 is attached to the air flow inlet 20 . The air flow inlet snorkel 24 may include a subsidiary branch inlet 25 for connection to an acoustic resonator. Conveniently, a corrugated air flow outlet duct, illustrated generally as 26 , is attached to the air flow outlet 22 . The air flow outlet duct 26 may be of any suitable configuration and length so that it may be attached to the motor air flow inlet. That inlet may be of any type depending upon the vehicle fuelling system.
[0010] The air flow chamber portion 12 defines a slot 30 for housing a panel filter assembly 32 . The slot 30 extends downwardly and forwardly toward the air flow outlet, thereby providing a generally wedge shaped inlet area on the intake side of the panel filter assembly, The panel filter assembly 32 includes a generally U-shaped, injection molded, housing 34 which contains a replaceable filter media 36 and a handle/retainer 38 . The handle/retainer 38 is received within air flow filter chamber portion clips 40 located on the air flow chamber portion 12 opposite either side of the slot 30 . The clips 40 and the handle/retainer 38 function to permit replacement of the filter media 36 as part of routine maintenance.
[0011] Air induction systems for automobiles require acoustic considerations in design. Typically, the air flow chamber portion 12 defines at least one acoustic chamber 50 for attenuation of sound waves in the air induction system. Advantageously, there may be a second acoustic chamber 52 which also serves to help in sound attenuation. While the shape and configuration of the acoustic chambers 50 and 52 are open for design and selection by the designer, the requirement for such chambers is one of the significant space issues in designing the assembly of the present invention. Sufficient space must be made available to permit the acoustic design necessary. Acoustic considerations may also require use of a resonator which may be ducted to the snorkel 24 . A duct connection 25 may be incorporated into the snorkel 24 for this purpose.
[0012] One of the major advantages of the present invention, is that it provides for a panel filter to be contained within the slot 30 . The panel filter may include a single function filtration media suitable for the purpose of filtering incoming air to the requisite degree of cleanliness. However, another important aspect of pollution control requirements now being mandated, is to ensure that the amount of hydrocarbon back flow from an engine on shut down be minimized. Accordingly, the panel filter may include addition media such as hydrocarbon adsorbers which will help diminish any reverse flow of hydrocarbon vapors from the engine fuelling system after engine shut down. Such systems work by absorbing the hydrocarbons that might pass upstream from the engine fuelling system and are retained on the adsorber. When the engine is started again, incoming air is drawn through the adsorber and the hydrocarbons are drawn back into the engine for normal combustion.
[0013] Advantageously, the air flow chamber portion 12 and the panel filter housing 34 are injection molded. The injection molded parts can then be made with sufficient accuracy to ensure appropriate sealing so that there is no escape of hydrocarbon vapors from the assembly, nor is there any unwanted air inlet leakage.
[0014] The liquid reservoir portion 14 of the assembly 10 comprises an internal closed chamber for retaining of liquids. The liquid reservoir portion 14 is advantageously made in a blow molding operation, a manufacturing process which is particularly suited to making hollow articles. The liquid reservoir portion 14 comprises an upstanding boss 70 having an inlet aperture 72 . The air flow chamber portion 12 includes an upstanding boss 74 with an inlet aperture 76 . In the assembled condition, the aperture 76 of boss 74 is aligned over aperture 72 of boss 70 to provide a fluid communication conduit to the chamber of liquid reservoir portion 14 . The liquid handling system advantageously includes a liquid filler pipe 80 having an openable and closable cap 82 . The liquid filler pipe 80 works together with a seal 84 to sealingly engage the aperture 76 to provide a leak-free fluid communication between the cap 82 and the chamber within the liquid reservoir portion 14 .
[0015] The liquid reservoir portion 14 may also include an outstanding and preferably downwardly extending boss 90 . The outstanding boss 90 may include a pump 92 together with a liquid level sensor 94 . The pump 92 can deliver fluid from the chamber within the liquid reservoir portion 14 under pressure. Most preferably, the liquid reservoir portion 14 can be utilized to contain disposable fluid such as windshield washer fluid. As the chamber is emptied, more fluid can be filled into the container through the cap 82 .
[0016] The liquid reservoir portion 14 advantageously includes a recess 35 to receive the lower end of the panel filter assembly 32 when the unit is assembled and the filter panel assembly is put in place.
[0017] Advantageously, the air flow chamber portion 12 may define a retention clip 100 . The retention clip 100 may then be used to position an additional liquid reservoir 102 . In this case, the additional liquid reservoir 102 may be used for other automobile fluids such as power steering fluid.
[0018] The air flow chamber portion 12 and the liquid reservoir portion 14 are affixed together as an assembly by means of a plurality of screws 110 which may be placed around the periphery of a flange 112 of the air flow chamber portion 12 . The plurality of screws 110 engage a plurality of bosses 120 formed in the periphery of the liquid reservoir portion 14 .
[0019] The assembly 10 may be affixed to the vehicle by means of outstanding flanges such as those illustrated at 130 and 132 . The flanges 130 and 132 are positioned as necessary so that the assembly may be fixed to the vehicle at convenient mounting points.
[0020] The embodiment illustrated in the figures, thus provides an assembly of several components. The assembly defines the air flow path for the vehicle from inlet through a filter to a clean air delivery duct and provides appropriate space and configuration to meet the vehicle inlet air flow considerations including acoustic requirements as well as providing an appropriate seal to minimize reverse flow of hydrocarbon vapors on engine shut down. The housing defines a slot for use with a panel type filter cartridge which may include suitable media for air cleaning and vapor retention. In addition, the assembly provides a liquid reservoir with a refill cap and pump mounting. In addition, in the embodiment illustrated in the figures, the assembly includes an additional reservoir for including an additional liquid such as power steering fluid. This whole assembly can be assembled prior to delivery of the assembly to the typical automobile assembly plant thereby reducing the amount of assembly required at the automotive assembly plant while still providing an assembly meeting a plurality of engine compartment requirements.
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This invention relates to an automotive air filter assembly, in particular, an assembly which includes an air flow chamber portion and a liquid reservoir portion. The air flow portion includes a panel filter for filtering air flowing to an engine. The panel filter includes air filtration media and hydrocarbon absorption media to inhibit release of hydrocarbon vapours to the air on engine shut down. The air flow portion also may include resonance chambers for acoustic silencing purposes. The liquid reservoir portion can include a pump for delivery of fluid such as windshield washer fluid.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is related to my co-pending application Ser. No. 815,910, filed July 15, 1977, entitled "Pipe Coating System."
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to improvements in vehicles and more particularly, but not by way of limitation, to complementary pairs of vehicles adapted for mutually telescopic disposition during the transporting of in-line objects.
2. Description of the Prior Art
The service life of steel pipes, and the like, is greatly increased by the application of an external coating material thereto. Steel pipe sections are normally relatively long and heavy and somewhat difficult to handle during a coating operation. In order to overcome the present-day difficulties of these pipe coating operations, the system as set forth in my aforementioned application has been developed wherein a plurality of individual pipe sections are moved sequentially through the steps required for the efficient coating operation. During many of the coating steps, the heavy pipe sections are supported by rolling or wheeled vehicles which carry the pipe sections through the coating stations in such a manner that the entire outer periphery of each pipe section is thoroughly and efficiently coated.
In order to achieve the optimum coverage during the coating operation, the system set forth in my co-pending application, including the combined longitudinal and rotation movement of each pipe section carried by the wheeled vehicles, is used. The pipe sections are moved in a forward longitudinal direction by suitable push roller means and rotated about the longitudinal axes thereof by suitable plug means carried by the wheeled vehicles. In order to provide a more efficient movement of the individual pipe sections carried by the wheeled vehicles, it is important that the pipe sections be maintained in a substantially abutting end-to-end relation, which is difficult to achieve with presently available rolling or wheeled vehicles of this type.
SUMMARY OF THE INVENTION
The present invention contemplates complementary pairs of wheeled vehicles for supporting individual pipe sections in a suspended manner therebetween. Each vehicle is provided with an upstanding pipe-engaging plug means for insertion within the open end of the pipe section whereby the pipe section is suspended therebetween with contact of the inner periphery thereof only, thus precluding any interference with the subsequent coating operations. The plug means is suitably journalled on the respective vehicle for free rotation in order that each pipe section may be rotated about its own longitudinal axis while moving longitudinally as the vehicle is moved in the direction of the length of the pipe.
Each vehicle is provided with at least two pair of axially aligned spaced wheels with one pair of said wheels being the front wheels and the other pair of said wheels being the rear wheels. The distance between the axially aligned front wheels is different from the distance between the axially aligned rear wheels whereby the rear wheels of a leading vehicle may move in a passing relation with the front wheels of the next succeeding following vehicle in order that the adjacent pipe ends of the two pipe sequential sections may be moved into a substantially end-to-end abutting relationship without interference between the two supporting vehicles.
In addition, it is important that all of the pipe sections continually rotate about the longitudinal axes thereof. In order to facilitate this rotational movement, each plug means is preferably provided with a clutch or ratchet means automatically engagable with the clutch or ratchet means of the adjacent plug means whereby the nesting or telescopic arrangement between the two adjacent vehicles will interconnect the plug means thereof and any rotation of one of the individual pipe sections will be transmitted throughout all of the pipe sections in the connected sequence.
As hereinbefore set forth, and as set forth in my aforementioned co-pending application, the individual pipe sections are engaged by suitable push rollers for imparting a longitudinal movement to the particular pipe section disposed in engagement therewith. The longitudinal movement is imparted from the engaged pipe to all of the preceding pipe sections by virtue of the end-to-end positioning and clutching engagement of the respective plug clutch means as hereinbefore set forth. In addition, the engagement of the push roller means with the pipe section imparts a simultaneous rotational movement to the particular pipe section engaged thereby. This rotational movement is transmitted to the plug means of the rotating pipe section, and the engaged clutch means between two adjacent plug means transmits the rotation to the next preceding pipe section, and so forth, thus providing for a continuous combined rotational and longitudinal movement for the pipe sections being transported by the vehicles.
Of course, when a pipe section suspended between a pair of the novel vehicles has been completely coated, the pipe section may be released from engagement with the plug means, and the empty vehicles may be moved in a reverse direction for repeating the operation with another pipe section, as set forth in my aforementioned co-pending application.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of a pair of wheeled vehicles embodying the invention and disposed in a nested or mutually telescopic position.
FIG. 2 is a plan view of a pair of wheeled vehicles embodying the invention and disposed in a nested or mutually telescopic position.
FIG. 3 is a front elevational view of a wheeled vehicle embodying the invention.
FIG. 4 is a view taken on line 4--4 of FIG. 1.
FIG. 5 is a view taken on line 5--5 of FIG. 1.
FIG. 6 is a view taken on line 6--6 of FIG. 1.
FIG. 7 is a sectional view of mating clutch elements such as used in the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings in detail, reference character 10 generally indicates a vehicle for supporting one end of a pipe section 12, and reference numeral 14 generally indicates a vehicle for supporting the opposite end of the pipe section 12, as will be hereinafter set forth. The vehicle 10 comprises a basic framework structure 16 which includes a first pair of mutually parallel spaced channel members 18 and 20 spaced from a substantially identical second pair of mutually parallel spaced channel members 22 and 24, as particularly shown in FIG. 2. Assuming the vehicles 10 and 14 move in a direction as indicated by the arrow 25, the rear or right-hand end of the channel members 18 and 20, as viewed in FIG. 2, may be rigidly secured in said spaced relation by a suitable cross member 26, and the rear of right-hand ends of the channels 22 and 24 may be similarly rigidly secured in said spaced relation by a cross member 27. The front or left-hand ends of the channels 18 and 20 and channels 22 and 24 may be secured in said spaced relation by a common cross member 28 which preferably extends transversely across the entire width of the vehicle 10, from the outboard channel 18 to the outboard channel 24. Thus, a substantially rectangular configuration is provided for the framework structure 26.
A first pair of substantially aligned, downwardly depending bracket members 30 and 32 are welded or otherwise secured to the channels 18 and 20 in the proximity of the cross member 26, and a second pair of substantially identical aligned brackets 34 and 36 are similarly rigidly secured to the channels 18 and 20 in the proximity of the cross member 28. A first wheel 38, which may be considered as a rear wheel, is suitably journalled between the brackets 30 and 32, and a second wheel 40, which may be considered as a front wheel, is suitably journalled between the brackets 34 and 36, with the wheels 38 and 40 being disposed in substantial "tracking" relationship for a purpose as will be hereinafter set forth.
A pair of downwardly depending oppositely disposed brackets 42 and 44 are welded or otherwise rigidly secured to the channels 22 and 24 in substantial alignment with the brackets 30 and 32, and a rear wheel 46 corresponding to the wheel 38 and in substantial axial alignment therewith is suitably journalled between the brackets 42 and 44. A pair of similar brackets 48 and 50 are secured to the channels 22 and 24 in substantial alignment with the brackets 34 and 36, and a front wheel 52 corresponding to the wheel 40 is suitably journalled therebetween. The wheel 52 is in substantial axial alignment with the wheel 40 and is in substantial "tracking " relationship with the wheel 46. In addition, it is preferable that one pair of "tracking" wheels, such as the wheels 38 and 40, be of a fixed axial position, but freely rotatable thereabout, whereas the other "tracking" wheels, such as the wheels 46 and 52, be floating wheels, or mounted in such a manner as to be axially movable, for a purpose as will be hereinafter set forth.
The wheels 38, 40, 46 and 52 may be of any suitable type, but as shown herein, it is preferable that the wheels be of the type having a grooved outer periphery for engagement with suitable rails 54 and 56, as particularly shown in FIG. 2, for moving therealong in the manner as set forth in my aforementioned co-pending application.
A pair of spaced tubular members 58 and 60 extend transversely across the upper portion of the frame 16 and are preferably supported in the proximity of each end by suitable block members 62 and 64, respectively, which are in turn secured to the channels 18, 20, 22, and 24 in any well-known manner (not shown). It is also preferable to provide a strengthening member 66 secured between the channel members 18, 20, 22, and 24 and spaced slightly from the tubular member 58 as will be seen in FIGS. 1 and 2. A pedestal 68 is secured to the tubular support members 58 and 60 in any well-known manner for supporting a plug means generally indicated at 70.
The plug means 70 is provided for supporting one end of the pipe section 12 and as shown herein comprises a substantially horizontally extending rotatable axle 72 journalled in a pillow block bearing 74, or the like, secured to a support block 75. The block 75 is slidably secured to the pedestal 68. A pipe engaging plug 76 is secured to one end of the axle 72 for rotation simultaneously therewith, and a clutch element 78 is secured to the opposite end of the axle 72 for rotation therewith, as will be hereinafter set forth in detail.
The pipe engaging plug means 76 is adapted for insertion within the open end of the pipe section 12, as shown in FIG. 1, and engages only the inner periphery of the pipe, thus precluding interference with the coating of the exterior of the pipe, and eliminating contact with the coating material subsequent to the application thereof to the pipe and prior to the complete curing of the coating material. In order to accomplish this, the plug means 76 as shown herein comprises a plate or disc member 77 bolted or otherwise secured to a complementary flange member 80 which is secured to one end of the axle 72 for rotation simultaneously therewith. A central core member 80 extends axially outwardly drom the plate 78 and is provided with a plurality of circumferentially spaced radially extending pipe engaging elements or shoes 82. The outer or exposed edge of each shoe 82 is serrated or stair-stepped, as particularly shown at 82 in FIG. 1 in order that the pipe engaging means 76 may be utilized with a variety of diametric sizes of pipe sections 12. In addition, it may be preferable that each step of the edge 84 be of a tapered configuration whereby the shoes 82 may be securely wedged against the inner periphery of the pipe section 12 when the pipe section 12 is being supported by the vehicles 10 and 14 as will be hereinafter set forth.
It is desirable to provide a protector 85 (shown in broken lines in FIGS. 1, 2 and 3) for each pipe plug apparatus 76 and which covers the exposed portions of the plug 76 as well as the end of the pipe section 12 supported thereon. This precludes accidental coating of the plug 76 and the end of the pipe during the coating operation. The protector 85 may be of any suitable configuration, and as shown herein is substantially arcuated in cross section, and is supported by the block 75 in any suitable manner for encasing the end of the pipe and the plate 77 without engagement thereof.
The vehicle 14 cooperates with the vehicle 10 for supporting a pipe section 12 therebetween, an for transmitting a combined rotational and longitudinal movement between a plurality of successively disposed pipe sections moving through a pipe coating system as set forth in my aforementioned co-pending application Ser. No. 815,910, filed June 15, 1977. The vehicle 14 comprises a pair of spaced mutually parallel transversely extending channel members 86 and 88 (FIG. 2) having the opposite ends thereof spaced apart by suitable cross members 90 and 92. A pair of inboard cross members 94 and 96 are spaced from the cross members 90 and 92, respectively. A pair of oppositely disposed downwardly depending brackets 98 and 100 are secured to the cross members 90 and 94 and a wheel 102, which is similar to the wheels 38 and 40, and which may be considered as a rear wheel, is suitable journalled therebetween. The wheel 102 is preferably a fixed wheel in the same manner as the wheels 38 and 40 as hereinbefore set forth. A second pair of oppositely disposed downwardly depending brackets 104 and 106 are secured to the cross members 92 and 16, respectively, and a wheel 108 similar to the wheels 46 and 52 is suitable journalled therebetween. The wheel 108 is in substantial axial alignment with the wheel 102 but is preferably a fixed wheel in that it is not free for axial movement.
A first pair of longitudinally extending mutually parallel spaced channel members 110 and 112 are disposed inboard of the wheel 102, as shown in FIG. 2, and the right-hand ends thereof as viewed in the drawings are rigidly secured to the cross members 86 and 88 in any well-known manner. A second pair of longitudinally extending mutually parallel spaced channel members 114 and 116 are disposed inboard of the wheel 108 in spaced relation with respect to the channels 110 and 112, and the right-hand ends of the channels 114 and 116 are similarly rigidly secured to the cross members 86 and 88 in any suitable manner. The forward or left-hand ends of the channels 110, 112, 114 and 116 are rigidly secured to a common cross member 118 in any well known manner, thus providing a substantially rectangular framework inboard of the wheels 102 and 108.
A pair of downwardly depending brackets 120 and 122 are secured to the channels 110 and 112 in the proximity of the cross member 118, and a wheel 124 similar to the wheels 102 and 108 is suitably journalled therebetween. A second pair of downwardly depending brackets 126 and 128 are secured to the channels 114 and 116, and a wheel 130 is suitably journalled therebetween. The wheel 130 is preferably a floating wheel, as hereinbefore set forth, and is in substantial axial alignment with the wheel 124, which is preferably a fixed wheel.
The wheels 102 and 108 are preferably of the same type as the wheels 38, 40, 46, and 52. The wheel 102 is preferably disposed in "tracking" relation with the wheels 38 and 40 and rides along the rail 54 as hereinbefore set forth. The wheel 108 is preferably disposed in "tracking" relation to the wheels 46 and 52 and rides along the rail 56 in the same manner thereas. The wheels 124 and 130 are also preferably of the type having a grooved outer periphery for engaging and rolling along rails 112 and 134. The rails 132 and 134 are disposed inboard of the rails 54 and 56, respectively, and preferably extending in spaced parallel relation thereto for a purpose as will be hereinafter set forth.
A plurality of transversely extending spaced strap members 136 are secured to the upper portions of the channels 110, 112, 114, and 116 as particularly shown in FIG. 2 and span the distance therebetween for supporting a substantially centrally disposed pedestal 138. A pipe engaging means 140 generally similar to the pipe engaging means 70, but oppositely disposed with respect thereto, is suitably secured to the upper end of the pedestal 138 and is so arranged as to be in substantial axial alignment with the pipe engaging means 70 at an adjacent vehicle, such as the vehicle 10. The pipe engaging means 140 comprises a suitable rotatable axle 142 journalled in a pillow block bearing 144, or the like, which is secured to a support block 145. The block 145 is slidably secured to the pedestal 138. A clutch element 146 is carried at one end of the axle 142 for simultaneous rotation therewith. A pipe engaging plug means 76 is carried at the opposite end of the axle 142 in the same manner and for the same purpose as hereinbefore set forth.
The clutch elements 78 and 146 are preferably complementary elements adapted for selective engagement for transmitting rotation therebetween. As particularly shown in FIGS. 5, 6, and 7, the clutch element 78 may comprise a main body 148 having a centrally disposed outwardly extending boss 150 on the outer face thereof extending in a direction toward the clutch element 146. A reduced diameter centrally disposed hub 152 extends outwardly from the boss 150. A pair of rotatable pawl elements 154 and 156 are suitably journalled on the exposed face of the boss 150 and are diametrically disposed on oppposite sides of the hub 152. Each pawl element is provided with a pair of angularly disposed outwardly extending fingers or pawls 156 and 158 as particularly shown in FIG. 5. One pawl, such as the pawl 158, engages the outer periphery of the hub 152, and the outer end of the other pawl 156 is free for a purpose as will be hereinafter set forth.
The clutch element 146 comprises a main body portion 160 having a central recess 162 provided in the outer face thereof for selectively receiving the hub member 152 therein. In addition, a pair of diametrically opposed lugs 164 are provided on the outer face of the body 160 for engagement by the free pawls 156 in the engaged position between the clutch elements 78 and 146. Each lug 164 is preferably provided with one tapered end 166 and one square end 168.
When the clutch elements 78 and 146 are moved into a clutching engagement as shown in FIG. 7, the elements are both normally rotated about the axes thereof, as will be hereinafter set forth. As the elements 78 and 146 move into engagement, the hub member 152 engages the recess 162, and the pawls 156 rotate with the body 148 until the free ends thereof engage the square ends 168 of the lugs 164. Upon engagement of the pawls 156 with the lugs 164, the clutch elements 78 and 146 are locked together for simultaneous rotation therebetween. In the event the element 146 is rotating in a direction opposite from the direction of rotation of the element 78, the free ends of the pawls 156 will ride over the tapered ends 166 and will not engage the lugs 164 in a driving relationship. Of course, it is preferable that the pawls 158 be connected with the outer face of the boss 150 by suitable spring members 170 for constantly urging the pawl elements 154 and 156 in a clockwise rotational direction, as viewed in FIG. 5 whereby the free ends of the pawls 156 are constantly urged in an outward direction for efficiently engaging the lugs 164 of the clutch elements 146 in the engaged position of the clutch members.
In use, a vehicle 10 is disposed in the proximity of one end of a pipe section 12, such as the rear or following end thereof, and a vehicle 14 is disposed in the proximity of the opposite end of the pipe. The support blocks 75 and 145 may be slidably moved with respect to the pedestals 68 and 138 in order that sufficient clearance is provided between the end of the pipe sections 12 and the pipe engaging plug members 76 whereby a plug member 76 may be inserted into the opposite ends of the pipe section. The support blocks 76 may then be slidably moved on the respective pedestals 68 and 138 for moving the shoes 82 into a wedging engagement with the inner periphery of the pipe, thus securely engaging the opposite ends of the pipe section whereby the pipe 12 will be supported by and suspended between the two vehicles 10 and 14. The vehicles and pipe carried thereby are then free for movement along the rails 54, 56, 132, and 134, as particularly set forth in my co-pending application. The floating wheels compensate for any variating of space between the trucks or rails.
As a pipe section is moved longitudinally in any well-known manner, such as by the push roller means (not shown) set forth in my co-pending application, and simultaneously rotated about its own longitudinal axis in any suitable manner, such as by said push rollers, the cars or vehicles 10 and 14 roll freely along the rails, and the axles 72 and 142 are rotated simultaneously with the pipe section. When a pair of adjacent tandem or lineally arranged pipe sections are moved in a position of substantial end-to-end abuttment, the clutch leading vehicle 14 of the second pipe section tests or telescopes with respect to the rear or following vehicles 10 of the first pipe section 12 as shown in FIGS. 1 and 2. In this relative position between the vehicles 10 and 14, the clutch element 78 of the car 10 is brought into engagement with the clutch element 146 of the car 14. When the clutch elements 78 and 146 are rotating in a common direction, the pawls 156 of the clutch element 78 will engage the ratchets or lugs 164 of the clutch element 146, and particularly the shoulders 168 thereof, for transmitting rotation between the engaged clutch elements. Thus any rotation of one pipe section 12 is transmitted to the second pipe section. In addition, any longitudinal movement of one pipe section is also transmitted to the other pipe section by virtue of the engagement of the clutch element of the cars 10 and 14.
In a pipe coating system as described and disclosed in my co-pending application, canted push rollers (not shown) are provided for engagement with the outer periphery of the pipe sections for transmitting both longitudinal and rotational movement to the pipe section engaged thereby. When a plurality of linear pipe sections are passing through the pipe coating system and through the push roller section thereof, the pipe sections which have previously moved through the push roller section are longitudinally and rotationally moved by the pipe sections disposed within the push roller section at any one time. The push rollers are preferably arranged so as to engage a single pipe section through a sufficiently great longitudinal distance as to engage the next succeeding pipe section prior to a complete disengagement from the first pipe section. In this manner, at least one pipe section in the string of succeeding pipe sections will always be driven in both a rotational and longitudinal direction by the push roller means. In addition, as a following pipe section approaches the immediately preceding pipe section, the rotational speed of the following pipe section will be brought up to substantially the same rotational speed of the preceeding pipe section prior to the engagement between the respective clutch elements 78 and 146. It will be readily apparent that all of the pipe sections in the system which have at least reached the push roller section will be maintained in a longitudinally and rotationally moving procession.
When the pipe sections no longer require transporting by the vehicles 10 and 14, the blocks 75 and 145 may once again be moved slidably with respect to the pedestals 68 and 138 for permitting a disengagement of the pipe engaging plug means 76 from the ends of the pipe section 12. The pipe sections may be removed from the vehicles in any well-known manner (not shown), and the vehicles may be moved in a reverse direction in any suitable manner (not shown) in order that they may be reused as required or desired.
It is preferable that the vehicles 10 and 14 not be powered. However, if desired, any suitable power source, such as a gasoline engine, or the like, may be provided for the vehicles. In addition, it may be desirable to provide one or both vehicles 10 and 14 with a suitable winch and line mechanism (not shown) for facilitating movement of the vehicles independently of the pipe sections.
From the foregoing, it will be apparent that the present invention provides complementary wheeled vehicles for supporting and moving linearly arranged objects in a manner whereby the vehicles may be intersonnected in a nesting relationship for facilitating a continuity of movement between the successive objects. The novel vehicles are simple and efficient in operation and economical and durable in construction.
Whereas the present invention has been described in particular relation to the drawings attached hereto, it should be understood that other and further modifications, apart from those shown or suggested herein may be made within the spirit and scope of this invention.
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Telescoping vehicles particularly designed and constructed for supporting the opposite ends of elongated members whereby one elongated member is suspended between a pair of the vehicles and a succeeding elongated member is suspended between a succeeding pair of vehicles, the vehicles being so arranged that the rear vehicle of the leading elongated member will nest or telescope within the leading vehicle of the following elongated member in such a manner that the adjacent ends of in-line elongated members will be in abutment.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to devices for removably mounting various articles, and more particularly, to quickly and securely removably mounting devices in predetermined locations.
2. Description of Related Art
Numerous types of mounting apparatuses exist for removably securing articles or devices to desired locations. For example, Garmin International, located in Olathe, Kans., manufactures the Nuvi GPS Windshield Suction Cup Mount and Bracket Bundle for removably securing portable GPS devices to the inside windshield of a vehicle. This suction cup mount requires a bracket that surrounds the entire GPS device and a relatively large suction cup to secure a GPS to a vehicle windshield. Annex Products, located in Prahran, Australia, manufactures the Quad Lock® bike mount for an IPhone® 6, which is a type of smartphone. The Quad Lock® bike mount requires a case that surrounds a smartphone, and the case is mechanically secured to a bracket that is attached to a bicycle with zip straps or zip ties. The mounting bracket of the Quad Lock® bike also requires significant space on the handlebars of a bicycle. Rokform, located in Santa Ana, Calif., manufactures a universal bike mount for securing a smartphone using a mounting bracket attached to the back of a smartphone. The mounting bracket can be attached to various mounting attachments, such as a suction cup, a magnet, and a bracket that is secured to handlebars of a bicycle.
While each of these known apparatuses for removably mounting a device to various locations, such as a bicycle, can be effective, each of these known apparatuses require significant space or real estate on the device and multiple physical movements to be secured, such as the Quad Lock®, with the need to push and twist, or the space needed on the location to which a device is to be removably secured, such as the handlebars on a bicycle. Accordingly, there is a need for a removable mounting apparatus that minimizes movement and the amount of space required on a device to be mounted and on a location for the device to be removably mounted.
ASPECTS AND SUMMARY OF THE PRESENT INVENTION
One aspect of the present invention is to provide a removable mount that minimizes the amount of space or real estate required on a device to attach the device to a desired location.
Another aspect of the present invention is to provide a removable mount that minimizes the amount of space or real estate required on a desired location to attach a device to that location.
A further aspect of the present invention is to provide a removable mount that automatically centers a device when it is attached to a predetermined mounting location.
An additional aspect of the present invention is to provide a removable mount that enables the orientation of a mounted device to be manually adjusted if desired.
In order to achieve these aspects and others, the Magnetik™ Mount of the present invention provides a self-centering and adjustable removable mount, such as for a bicycle, having a circular base with an outer periphery, an upper inner wall with a first diameter, and a lower inner wall with a second diameter, wherein the first diameter is greater than the second diameter. An inner platform is located between a bottom of the upper inner wall and a top of the lower inner wall. Opposing outer sloping edges are on the outer periphery of the circular base, and a notch is formed between bottoms of the opposing outer sloping edges. A cylindrical shell surrounds the outer sloping edges of the circular base, and the cylindrical shell includes a tab on a lower inner wall of the cylindrical shell sized to fit into the notch of the circular base, wherein the outer sloping edges of the circular base guide the tab to slip into the notch when the cylindrical shell is placed around the circular base, thereby positioning the cylindrical shell in a predetermined orientation. A base magnet is located within the circular base and above the inner platform, and a lid is to be located on a top of the cylindrical shell. An outer perimeter on the bottom cover of the lid is teethed and the top of the cylindrical shell is teethed, and the lid and the cylindrical shell interlock when the lid is positioned on top of the cylindrical shell. A lid magnet is located within the lid, wherein the lid magnet is magnetically attracted to the base magnet when the lid is positioned on top of the cylindrical shell. The lid is to be secured to the back of a device to be removably mounted, such as a smartphone. An anti-snag guide surrounding the perimeter of the lid can be included, wherein an inner wall of the anti-snag guide extends at least to a top of the teeth of the lid, and an outer perimeter of the anti-snag guide slopes outward toward the back of the phone.
The foregoing has outlined, rather broadly, the preferred features of the present invention so that those skilled in the art may better understand the detailed description of the invention that follows. Additional features of the invention will be described hereinafter that form the subject of the claims of the invention. Those skilled in the art should appreciate that they can readily use the disclosed invention and specific embodiments as a basis for designing or modifying other structures for carrying out the same purposes of the present invention, and that such other structures do not depart from the spirit and scope of the invention in its broadest form.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a bicycle including a mount configured in accordance with the present invention to secure a smartphone to a steering column of the bicycle;
FIG. 1 a is an enlarged view of the smartphone secured to the bicycle using the mount of the present invention of FIG. 1 shown from a different angle;
FIG. 1 b is an exploded view of a smartphone on the bicycle using the mount of present invention shown in FIG. 1 , wherein a smartphone includes an anti-snag guard on a lid of the mount;
FIG. 2 a is a perspective view of the top of the mount shown in FIG. 1 a;
FIG. 2 b is a perspective view of the bottom of the mount shown in FIGS. 1 a and 2 a;
FIG. 3 is an enlarged perspective view of the mount of the present invention shown in FIGS. 1 a and 2 a wherein the smartphone has been removed from the mount;
FIG. 3 a is an enlarged view of the steering column of the bicycle and the mount shown is FIGS. 1 a , 2 a and 3 , wherein the smartphone and a cylindrical shell of the mount have been removed exposing a circular base of the mount.
FIG. 3 b is another view of the steering column of bicycle shown in FIG. 3 a , wherein the mount has been removed, exposing a bolt in the bicycle for tightening components of the steering column, and that bolt is utilized by present invention to secure the circular base to the top of the steering column;
FIG. 4 a is an enlarged perspective view of the smartphone shown in FIGS. 1 and 1 a after removal from the mount of the present invention shown in FIGS. 1-3 , and a lid from the mount can be seen attached to the back of the smartphone;
FIG. 4 b is a perspective view of the smartphone shown in FIG. 4 a from a different angle;
FIG. 4 c is an enlarged perspective view of the smartphone shown in FIG. 1 b including an anti-snag guide on the lid of the mount of the present invention;
FIG. 5 a is a perspective of the bottom of the lid of the mount shown in FIGS. 4 a and 4 b removed from the smartphone;
FIG. 5 b is a perspective view of the lid shown in FIG. 5 b from a different angle;
FIG. 5 c is a perspective view of the top of the lid shown in FIGS. 5 a and 5 b;
FIG. 5 d is a perspective view of the top of the lid shown in FIGS. 5 a -5 c wherein the lid magnet has been removed;
FIG. 6 a is a perspective view of the top of a cylindrical shell of the mount shown in FIG. 3 including a base magnet and configured in accordance with the present invention;
FIG. 6 b is a perspective view of the shell shown in FIG. 6 a from a different angle;
FIG. 6 c is a perspective view of the bottom of the cylindrical shell shown in FIGS. 6 a and 6 b from a different angle;
FIG. 7 a is a perspective view of the top of the cylindrical shell shown in FIGS. 6 a -6 c wherein a base magnet, a circular base, locking bolt, and cylindrical insert have been removed from the cylindrical shell;
FIG. 7 b is a perspective view of the cylindrical shell shown in FIG. 6 a from a different angle;
FIG. 7 c is a perspective view of the bottom of the cylindrical shell shown in FIGS. 6 a and 6 b shown from a different angle;
FIG. 8 a is a perspective view of the top of the circular base and the cylindrical insert of the mount shown in FIG. 3 a;
FIG. 8 b is a perspective view of the top of the circular base and the cylindrical insert shown in FIG. 8 a from a different angle;
FIG. 8 c is a perspective view of the top of the circular base and the cylindrical insert shown in FIGS. 8 a and 8 b;
FIG. 8 d is a perspective view of the front of the circular base and the cylindrical insert shown in FIGS. 8 a - 8 c;
FIG. 8 e is a perspective view of the bottom of the circular base and the cylindrical insert shown in FIGS. 8 a - 8 d;
FIG. 8 f is a perspective view of the bottom of the circular base and the cylindrical insert shown in FIGS. 8 a -8 e from a different angle;
FIG. 9 a is a perspective view of the top of the circular base without the cylindrical insert shown in FIGS. 8 a - 8 f;
FIG. 9 b is a perspective view of the top of the circular base shown in FIG. 9 a;
FIG. 9 c is a perspective view of the top of the circular base shown in FIGS. 9 a and 9 b from a different angle;
FIG. 9 d is a perspective view of the top of the circular base shown in FIGS. 9 a -9 c from a different angle;
FIG. 9 e is a perspective view of the bottom of the circular base shown in FIGS. 9 a -9 d from a different angle;
FIG. 9 f is a perspective view of the bottom of the circular base shown in FIGS. 9 a -9 e from a different angle;
FIG. 10 a is a perspective view of the top of the cylindrical insert shown in FIGS. 8 a - 8 f;
FIG. 10 b is a perspective view of the cylindrical insert shown in FIG. 10 a from a different angle; and
FIG. 10 c is a perspective view of the bottom of the cylindrical insert shown in FIGS. 10 a and 10 b.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, FIG. 1 is a perspective view of a bicycle 5 including a steering column 6 , handlebars 8 , handgrips 9 , and a seat 11 . The bicycle 5 includes a front wheel 13 and a rear wheel 15 . In accordance with the present invention, a smartphone 12 is removably secured to the top of the steering column 6 of the bicycle 5 using a magnetic mount.
FIG. 1 a is enlarged view of the steering column 6 , handlebars 8 , and smartphone 12 shown in FIG. 1 from a different angle looking upward. Further shown is a stem 14 for connecting the handlebars 8 to the steering column 6 . The handlebars 8 are secured to the stem 14 using a clamping bracket 16 .
In accordance with the present invention, a mount 10 is provided for securing the smartphone 12 to the top 17 of the steering column 6 . The mount 10 includes a lid 18 connected to the back 19 of the smartphone 12 . A circular base 20 of the mount 10 is connected to the top 17 of the steering column 6 , and a cylindrical shell 22 of the mount 10 connects the lid 18 to the circular base 20 . The lid 18 is connected to the cylindrical shell 22 .
FIG. 1 b is an enlarged exploded view of the mount 10 shown in FIG. 1 a , except the lid 18 includes an anti-snag guide 32 which surrounds the periphery of the lid 18 . The anti-snag guide 32 slopes outward towards a back 7 of the smartphone 4 . The bottom 71 of the anti-snag guide 32 is secured to the back 7 of the smartphone 4 , and the top 73 of the anti-snag guide 32 extends to at least the top of the teeth 26 of the lid 18 . The anti-snag guide 32 preferably is constructed of rubber or other elastic material and is stretched around the lid 18 to be secured to the lid 18 and smartphone 4 .
FIG. 2 a is an enlarged perspective view of the mount 10 shown in FIG. 1 a and configured in accordance with the present invention, wherein the complete mount 10 has been removed from both the bicycle 5 and the smartphone 12 . The mount 10 includes the lid 18 and the cylindrical shell 22 . The lid 18 includes a top cover 23 and a bottom cover 25 . The bottom 21 of the bottom cover 25 is teethed 26 around the periphery. The top cover 23 and the bottom cover 25 of the lid 18 are preferably molded from a polymer, such as plastic. The top 69 of the top cover 23 of the lid 18 preferably includes an adhesive, such as 3M 4646 VHB, for securing the lid 18 to a device or an article to be removably mounted, such as a smartphone or a handheld global positioning system (GPS).
A cylindrical shell 22 is located below the lid 18 . The top 27 of the cylindrical shell 22 is teethed 28 . The teething 28 of the cylindrical shell 22 and the teething 26 of the lid 18 are sized so as to interlock when the bottom 21 of the lid 18 is placed on the top 27 of the cylindrical shell 22 . The cylindrical shell 22 includes a threaded aperture 29 on the side for receiving a bolt 30 . The bolt 30 can be tightened to secure the cylindrical shell 22 to a circular base 20 ( FIG. 2 b ).
FIG. 2 b is a perspective view of the bottom 31 of the mount 10 shown in FIG. 2 a . FIG. 2 b illustrates a circular base 20 located within the cylindrical shell 22 . A cylindrical insert 34 is located within the circular base 20 . An aperture 33 is located within the cylindrical insert 34 for receiving a bolt, such as bolt 54 in FIG. 3 b , to secure the mount 10 to a desired location. A tab 35 is located on an inner wall 37 of the cylindrical shell 22 . A notch 36 is located within the circular base 20 , and the tab 35 is sized to be received within the notch 36 . The tab 35 and the notch 36 function to properly position the cylindrical shell 22 over and around the circular base 20 .
FIG. 3 is an enlarged perspective view of the mount 10 on the steering column 6 of the bicycle 5 shown in FIGS. 1 and 2 , wherein the smartphone 12 and lid 18 have been removed. An upper rim 39 of the cylindrical insert 34 is shown located within the circular base 20 , and the cylindrical shell 22 is located around and over the circular base 20 . A first magnet or base magnet 40 ( FIG. 6 a ) is to be located within the cylindrical shell 22 , and the base magnet 40 attracts and secures the cylindrical shell 22 , which is constructed of a magnetic metal, to the circular base 20 . The teeth 28 on the top 27 of the cylindrical shell 22 are further illustrated in FIG. 3 .
FIG. 3 a is an enlarged perspective view of the handlebars 8 and the circular base 20 of the mount 10 , wherein the cylindrical shell 22 has been removed to more clearly illustrate the circular base 20 . Also illustrated are the clamping bracket 16 , stem 14 , and steering column 6 .
In accordance with the present invention, the circular base 20 includes opposing sloping edges 42 , 44 on the outer wall 43 of the circular base 20 . A notch 36 is formed between the bottoms 45 , 47 of the opposing sloping edges 42 , 44 . A plateau 46 is formed between the tops 48 , 49 of the opposing sloping edges 42 , 44 . The circular base 20 is preferably constructed of non-magnetic metal or plastic. A cylindrical insert 34 is located within the circular base 20 . The cylindrical insert 34 includes a cylindrical body 50 having an upper outer rim 52 on the outer surface of the cylindrical body 50 .
FIG. 3 b is an enlarged perspective view of the handlebars 8 and steering column 6 shown in FIG. 3 a , wherein components of the mount 10 have been removed, exposing the bolt 54 for tightening the bicycle components of the steering column 6 . In accordance with the present invention, the bolt 54 fits through the aperture 33 of the cylindrical insert 34 to secure the circular base 20 to the top 17 of the steering column 6 . Most, if not all, bikes have a very long bolt such as bolt 54 that hold the entire structure of the steering column 6 of a bicycle together. This bolt generally has plenty of extra thread to allow it to be unscrewed and have an object, like our Magnetik™ base mount 10 of the present invention, to be inserted onto and screwed back down so everything is held together as if nothing changed other than there is now a circular base as a permanent interface to removably mount a phone or other desired item.
FIG. 4 a is a perspective view of the back 19 of the smartphone 12 shown in FIGS. 1 a and 2 a . The top cover 23 of lid 18 is shown affixed to the back 19 of the smartphone 12 , preferably by adhesive. The teeth 26 on the bottom 21 of the bottom cover 25 of the lid 18 are further illustrated. FIG. 4 b is a perspective view of the back 19 of the smartphone 12 , similar to FIG. 4 a , but shown from a different angle. Illustrated again is the lid 18 preferably glued to the back 19 of the smartphone 12 . The teeth 26 on the bottom cover 25 of the lid 18 also are visible.
FIG. 4 c is an enlarged perspective view of the smartphone 4 and lid 18 including the anti-snag guide 32 shown in FIG. 1 b . The anti-snag guide 32 surrounds the periphery of the lid 18 . The anti-snag guide 32 slopes outward towards the back 7 of the smartphone 4 . The bottom 71 of the anti-snag guide is secured to the back 7 of the smartphone 4 , preferably by gluing, and the top 73 of the anti-snag guide 32 extends to at least the top of the teeth 26 of the lid 18 . The anti-snag guide 32 preferably is constructed of an elastic plastic that stretch around the periphery of the lid 18 .
FIG. 5 a is a perspective view of the lid 18 including the top cover 23 and the bottom cover 25 . An enlarged view of the teeth 26 on the periphery of the bottom 21 of the bottom cover 25 are further illustrated. Apertures 41 are included in the bottom cover 25 to facilitate alignment of the lid 18 . The apertures 41 are located at 90 degrees from one another to enable a user to more accurately align the lid 18 at the desired location and desired orientation.
FIG. 5 b is a perspective view of the side of the top cover 23 and bottom cover 25 of the lid 18 shown in FIG. 5 a . The teeth 26 on the bottom or bottom face 21 of the bottom cover 25 of the lid 18 are clearly illustrated. The top 75 of the top cover 23 preferably includes an adhesive, such as 3M VHB adhesive, for securing the top 75 to a desired location, such as the back of a smartphone or other device.
FIG. 5 c is a perspective view of the top surface 51 of the bottom cover 25 of the lid 18 . The teeth 26 and apertures 41 can be seen. Also illustrated is the second magnet or lid magnet 56 located in a cavity 55 within the bottom cover 25 of the lid 18 . The second magnet 56 is magnetically attracted to the first magnet 40 in the circular base 20 when the lid 18 , attached to a smartphone or other device, is placed on top of the cylindrical shell 22 , thus holding the lid 18 on the cylindrical shell 22 .
The lid 18 preferably is milled out of aluminum or extruded with ABS plastic, which then has a 7-pound magnet mounted inside the cavity 55 using epoxy. The north and south poles on the magnet 40 are fixed in order to be attracted to the magnet 56 within the cylindrical shell 22 ( FIG. 6 a ).
FIG. 5 d is a perspective view of the top surface 51 of the bottom cover 25 of the lid 18 shown in FIG. 5 c , except the lid magnet 56 has been removed to more clearly see the cavity 55 for storing the magnet 56 . The apertures 41 and the teeth 26 on the bottom surface or face 21 of the bottom cover 25 of the lid 18 also are illustrated.
FIG. 6 a is a perspective view of the top 27 of the cylindrical shell 22 showing the teeth 28 on the top or top surface 27 of the cylindrical shell 22 . The locking bolt or locking screw or bolt 30 is located within the threaded aperture 29 . The base magnet 40 is shown located within a cavity 58 in the upper portion of the cylindrical shell 22 . A ledge 59 is formed between the upper inner wall 60 of the cylindrical shell 22 and the side wall 61 of the cavity 58 . The cylindrical shell 22 preferably is milled out of 6061-t6 aluminum or extruded ABS plastic. The base magnet 40 preferably is a 19-pound magnet mounted inside the cavity 58 using epoxy. The base magnet 40 is mounted to have a fixed north and south pole in order to attract to the second or lid magnet 56 within the lid 18 .
FIG. 6 b is a perspective view of the side of the cylindrical shell 22 shown in FIG. 6 a . The teeth 28 , top surface 27 , and upper inner wall 60 of the cylindrical shell are illustrated. The lock bolt 30 also is illustrated.
FIG. 6 c is a perspective view of the bottom 62 of the cylindrical shell 22 shown in FIGS. 6 a and 6 b . Similar to FIGS. 6 a and 6 b , the teeth 28 and locking bolt 30 are illustrated. FIG. 6 c further illustrates the bottom 63 of the circular base 20 and the bottom and lower inner rim 65 of the cylindrical insert 34 . The notch 36 on the circular base 20 can be seen as well as the tab 35 of the cylindrical shell 22 located within the notch 36 .
FIG. 7 a is a perspective view of the top 27 of the cylindrical shell 22 shown in FIGS. 6 a -6 c wherein the second magnet 40 , the lock bolt 30 , the circular base 20 , and the cylindrical insert 34 have been removed. The teeth 28 and the threaded aperture 29 are shown, as well as the upper inner wall 60 of the cylindrical shell 22 and the side wall 61 of the cavity 58 . The ledge 59 is shown between the upper inner wall 60 and the side wall 61 . The top of the floor 57 of the cavity 58 can be seen with the base magnet 40 removed. FIG. 7 b is a perspective side view of the cylindrical shell 22 shown in FIG. 7 a.
FIG. 7 c is a perspective view of the bottom 62 of the cylindrical shell 22 shown in FIGS. 7 a and 7 b . The full length of the tab 35 on the lower inner wall 64 of the cylindrical shell 22 can be seen with circular base 20 and the cylindrical insert 34 removed. The bottom of the floor 57 of the cavity 58 can also be seen with the circular base 20 and the cylindrical insert 34 removed.
FIG. 8 a is a perspective view of the top of the circular base 20 and the cylindrical insert 34 properly positioned within the circular base 20 . The upper outer rim 52 of the cylindrical insert 34 is located within the circular base 20 , and below or level with the top rim or surface 66 of the circular base 20 . The inner wall of the cylindrical body 50 of the cylindrical insert 34 extends all the way through the circular base 20 , wherein the lower inner rim 65 of the cylindrical insert 34 becomes flush with the bottom surface of the circular base 20 , as shown in FIG. 8 f.
The opposing sloped edges 42 , 44 are located on the outer wall 43 of the circular base 20 . The tab 46 is located between the upper ends 48 , 49 of the opposing sloped edges 42 , 44 . An aperture 68 is located in the side of the opposing sloped edges 42 , 44 below the plateau or tab 46 . The aperture 68 is preferably threaded and receives and secures the locking bolt 30 to secure the cylindrical shell 22 over the circular base 20 .
FIG. 8 b is a perspective view of the top of the circular base 20 and cylindrical insert 34 shown in FIG. 8 a from a different angle. The notch 36 is shown between the bottoms 45 , 47 of the opposing sloping edges 42 , 44 . Also shown is the top of the inner lower rim 65 of the cylindrical insert 34 . The aperture 33 is located in the lower inner rim 65 for received the steering column bolt 54 to secure the cylindrical insert 34 and the circular base 20 to the top 17 of a steering column 6 of a bicycle. Of course, other bolts or screws can be located within the aperture 33 to secure the cylindrical insert 34 and circular base 20 to any desired location, such as a vertical wall, cabinet, etc. The upper outer rim 52 of the cylindrical insert 34 secures the circular base 20 in place by being placed firmly against the plateau 70 ( FIG. 9 a ) of the circular base 20 when the cylindrical insert 34 is secured by a bolt or screw via the aperture 33 . In an alternative embodiment, the bottom of the circular base 20 and/or the lower inner rim 65 of the cylindrical insert 34 can include an adhesive for gluing the circular base 20 to a desired location.
FIG. 8 c is a perspective view of the top of the circular base 20 and the cylindrical insert 34 shown in FIGS. 8 a and 8 b from another angle. FIG. 8 d is a front perspective view of the circular base 20 and cylindrical insert 34 . FIGS. 8 e and 8 f are perspective views of the bottom 63 of the circular base 20 and cylindrical insert 34 shown in FIGS. 8 a -8 d from different angles.
FIGS. 9 a -9 d are perspective views of the top of the circular base 20 shown in FIGS. 8 a -8 f , wherein the cylindrical insert 34 has been removed. The inner platform or plateau 70 located between the upper inner wall 74 of the circular base 20 and the lower inner wall 72 of the circular base 20 . The upper outer rim 52 of the cylindrical insert 34 , as shown in FIGS. 8 a -8 c , fits within the upper inner wall 74 and on top of the inner platform 70 . The cylindrical body 50 of the cylindrical insert 34 is located within the lower inner wall 72 of the circular base 20 .
FIGS. 9 e and 9 f are perspective views of the bottom 63 of the circular base 20 shown in FIGS. 8 e and 8 f , wherein the cylindrical insert 34 has been removed. With the cylindrical insert 34 removed, the lower inner wall 72 of the circular base 20 is clearly visible. The circular base 20 preferably is milled out of 6061-t6 aluminum or extruded ABS plastic, which then has 1008 low carbon steel insert mounted inside the center of base 20 with epoxy within the lower inner wall 72 . The steel is necessary to maintain the magnetic attraction to the cylindrical shell 22 .
FIG. 10 a is a perspective view of the top of the cylindrical insert 34 shown in FIGS. 8 a -8 f . The upper outer rim 52 , cylindrical body 50 , lower inner rim 65 , and aperture 33 of the cylindrical insert 34 are clearly visible in FIG. 10 a . FIG. 10 b is a perspective view of the side of the cylindrical insert 34 shown in FIG. 10 a showing the cylindrical body 50 and upper outer rim 52 . FIG. 10 c is a perspective view of the bottom of the cylindrical insert 34 shown in FIGS. 10 a and 10 b illustrating the upper outer rim 52 , cylindrical body 50 , lower inner rim 65 , and aperture 33 .
While specific embodiments have been shown and described to point out fundamental and novel features of the invention as applied to the preferred embodiments, it will be understood that various omissions and substitutions and changes of the form and details of the invention illustrated and in the operation may be done by those skilled in the art, without departing from the spirit of the invention.
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A self-centering and adjustable removable mount having a circular base and opposing outer sloping edges on the outer periphery of the circular base. A notch is formed between the bottoms of the opposing outer sloping edges. A cylindrical shell surrounds the outer sloping edges of the circular base, and the cylindrical shell includes a tab on a lower inner wall of the cylindrical shell sized to fit into the notch of the circular base, wherein the outer sloping edges of the circular base guide the tab into the notch when the cylindrical shell is placed around the circular base, thereby positioning the cylindrical shell in a predetermined orientation. A magnetized lid is connected to the back of a device to be mounted, and the magnetized lid is attracted to a base magnet when the lid is positioned on top of the cylindrical shell.
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PRIORITY DATA
[0001] This application claims priority to U.S. Provisional Patent Application No. 62/264,658 filed Dec. 8, 2015, which is incorporated herein in its entirety.
FIELD OF INVENTION
[0002] The present invention is generally related to concrete form systems. In particular, the present invention is directed to an internally-braced concrete form system for ballast foundations.
BACKGROUND
[0003] Foundations which are used to support surface structures of many types, are preferably formed by substantial amounts of excavation to interface the foundation with the substrate, and provide stability. This is important for both the stability of the foundation and any structures supported thereby. However, there are a number of situations in which conventional excavation is impossible or not appropriate.
[0004] In such situations, structures known as ballast foundations must be used. These are foundations that support their overlying structures by virtue of the mass of the foundation resting upon the surface of the substrate (such as the underlying ground, pavement, structure, or the like) to provide stability to the structure supported thereon.
[0005] In many situations, concrete foundations are poured to have a large “footprint”. These foundations are often very shallow, being only a few inches in thickness. In some situations, multiple foundation structures are connected together for stability with elaborate superstructure configurations. Very often shallow ballast foundations are stabilized with external anchors driven into the substrate around the ballast foundation.
[0006] Unfortunately, there are a number of situations in which large footprints are inappropriate. One example is when there is an extremely uneven substrate contour. Further, in many circumstances it is inappropriate to excavate, even if only to drive relatively small anchors into the substrate around ballast foundations. One example of such circumstances includes landfills upon which structures are to be placed. In landfills, structures are typically anchored without excavating, or otherwise disturbing the underlying earth or substrate.
[0007] In some circumstances, the substrate surface is not flat, but the concrete pour of the ballast foundation must still conform to the topography of the underlying substrate. In order to provide proper support for various structures, the ballast foundations must be configured so as to provide the necessary support at any part of the substrate to be utilized.
[0008] One solution to the aforementioned problems is the use of precast ballast foundations which are manufactured (including the metal supports extending from the concrete pour) at another location and then transported to the site at which the structure is to be placed on the foundation. However, as efficient as this solution may appear to be, there are substantial drawbacks. In particular, transporting ballast foundations to the final support site may be impractical due to the fragility of the substrate (such as with the covering at a landfill). This is particularly problematic if large ballast foundations are required to support the structure to be mounted. The necessary handling equipment, such as large cranes, may not be able to traverse the substrate upon which the ballast foundations are to be placed. Moreover, this is especially true in situations such as landfills covered with relatively fragile turf. To be clear, if the structure to be mounted on the ballast foundation is to be located on a site where the substrate is still settling, or is subject to various types of environmental degradation, there may not be an appropriate place to safely put precast ballast foundations.
[0009] Further yet, the exact placement upon the construction site may be difficult so that propositioned metallic supports placed in the concrete may be inappropriately positioned for the structure to be supported. This is exacerbated by changes in the substrate covering a landfill for example, which might make repositioning of the overall supported structure necessary. Metallic extensions, such as vertical support structures, in precast ballast foundations may prove to be impossible to use due to inexact measurements taken before precasting or due to environmental changes. Once metallic supports are precast in concrete, they cannot be altered to accommodate changes at the job site.
[0010] Accordingly, concrete form system for ballast foundations, that can be assembled on-site and will allow adaptation to various types of substrate without excavation, is needed. In many situations, it is far easier to run a tube carrying liquid concrete from another location (more stable) to the site at which the ballast foundation is required. The resulting ballast foundation erected on-site must be sufficiently stable to support relatively heavy and unstable upper structures. The form system must be easy to ship and assemble, and should be adaptable to a wide range of foundation requirements.
SUMMARY OF THE INVENTION
[0011] Accordingly, it is a primary object of the present invention to provide a concrete form system to fabricate concrete ballast foundations suitable for a wide variety of different substrates and environments, without excavation of the substrate.
[0012] It is another object of the present invention to provide a concrete form system that is internally braced to be self-supporting.
[0013] It is an additional object of the present invention to provide a concrete form system with adjustable vertical structural supports.
[0014] It is a further object of the present invention to provide a ballast foundation concrete form system that is easily transportable in a compact package and can easily be assembled on-site for a concrete pour.
[0015] It is still another object of the present invention to provide a metal ballast foundation concrete forms system that is easily manufactured while still providing a sufficiently robust structure to withstand forces generated by large concrete pours.
[0016] It is yet an additional object of the present invention to provide a ballast foundation concrete form system that is easily transported and safely assembled at remote pour sites.
[0017] It is again a further object of the present invention to provide a ballast foundation concrete form system that is easily configurable and assembled on-site, while being designed for optimal nesting and stacking for transportation.
[0018] It is again another object of the present invention to provide a ballast foundation concrete form system that is inexpensive, simple to manufacture, transport and assemble on-site.
[0019] It is still a further object of the present invention to provide a ballast foundation concrete form system that admits to a wide variety of different internal bracing configurations for a wide range of ballast foundation sizes and uses.
[0020] It is yet an additional object of the present invention to provide a ballast foundation concrete form system that is easily manufactured to specific ballast foundation requirements so that the proper amount of concrete is always used to provide the weight for a specified load on the substrate beneath the ballast foundation.
[0021] These and other goals and objects of the present invention are achieved by a ballast foundation system constituted by interacting portable parts configured to a substrate underlying the ballast foundation system. The ballast foundation system in this case preferably includes at least two folding metallic casing sections arranged together to enclose a space over the substrate. The metallic casing sections are configured in two sets of attached opposing walls. A bracing configuration is arranged internal to the metallic casing sections and includes at least one longitudinal cross brace locked to the first set of opposing walls, a plurality of transverse cross braces, each attached to the longitudinal cross brace and locked to a second set of opposing walls. Also included is at least one upright vertical support attached to the longitudinal cross brace and to at least one of the transverse cross braces. A concrete pour is arranged within the metallic casing sections where the concrete pour conforms to the substrate underlying the ballast foundation system and rises no higher than the vertical height of the opposing walls of the metallic casing.
[0022] In another embodiment of the present invention, a ballast form is arranged to be placed on a substrate at the construction site. The ballast form includes two metal sheets each having a length, with a flat outer surface. Each of the sheets includes at least one V-notch at opposing edges along the length of the sheet, and creases across the width from the V-notch for bending to form an enclosure by connecting both metal sheets on-site on the substrate. The enclosure has first and second sets of parallel sidewalls once assembled. A bracing system is arranged inside the enclosure and includes at least one longitudinal cross brace and a plurality of transverse cross braces within the enclosure secured to the first and second sets of sidewalls. More specifically, the longitudinal cross brace is secured to the first set of sidewalls and each of the transverse cross braces is secured to the longitudinal cross brace and to the second set of parallel sidewalls. At least one substantially vertical support is placed within the enclosure and is also attached to the longitudinal and transverse cross braces. Concrete is poured and contained within the braced enclosure above the substrate, and is no thicker than the width of the metal sheets.
[0023] Another embodiment of the present invention includes a process for building a ballast foundation on-site wherein the process includes the manufacture of a plurality of enclosure sections of steel (i.e., each of the enclosure sections being formed, notched and scored using a single sheet of steel). Next, a plurality of the enclosure sections are stacked and shipped on a transport vehicle to at least one predetermined insulation site. Then, at least two of the enclosure sections are removed from the transport vehicle at a first predetermined installation site. The two enclosure sections are folded and placed together to form an enclosure. The enclosure is internally braced with at least one longitudinal brace and a plurality of transverse cross braces. The bracing is locked to the enclosure by locking tabs extending through slots in the enclosure. Then, at least one substantially vertical upright support is attached and adjusted to the desired vertical angle. Finally, concrete is poured into the enclosure to form a single integrated permanent ballast foundation from the enclosure with proper bracing and the substantially vertical upright support extending therefrom.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 is a perspective view of the assembled system configured for a concrete pour.
[0025] FIG. 2 is a perspective view of a single form section as manufactured.
[0026] FIG. 3 is a magnified side view of the V-notch portion of a concrete form section, in a configuration suitable for bending at installation.
[0027] FIG. 4 depicts the same structure as FIG. 3 , but with the form section bent and configured for assembly, such as that depicted in FIG. 1 .
[0028] FIG. 5 is a perspective view of a single form section bent and arranged for assembly with another form section (not shown).
[0029] FIG. 6 is a cross-sectional view of the bottom portions of two opposing form sections arranged in parallel to each other on a substrate.
[0030] FIG. 7A is an end view of the structure depicted in FIG. 1 .
[0031] FIG. 7B is an enlarged view of a portion of the structure in FIG. 7A , with a connecting flange of a brace depicted in the extended position passing through the form section sidewall.
[0032] FIG. 7C is a depiction of FIG. 7B , with the connecting flange bent to secure the brace in position to the form section sidewall.
[0033] FIG. 8A is a side elevational view of the structure of FIG. 1 .
[0034] FIG. 8B is an enlarged diagram of two identical portions of the structure of FIG. 8A , depicting connections between transverse and longitudinal cross braces, and vertical supports.
[0035] FIG. 9 is a magnified perspective view depicting the interconnections of multiple support pieces from FIG. 8B .
[0036] FIG. 10 is a magnified view of the interconnections between a vertical support and a tilt top cord.
[0037] FIG. 11 is a side elevational view depicting the tolerances in a first direction for positioning of the vertical supports with respect to internal cross bracing.
[0038] FIG. 12 is an end view of FIG. 11 , depicting tolerances in another direction for positioning the vertical supports.
[0039] FIG. 13A is a top view of the subject concrete forms arranged and packaged for shipping.
[0040] FIG. 13B is a side elevational view of the packaged forms of FIG. 13A .
[0041] FIG. 13C is an end view of the packaged concrete forms depicted in FIG. 13B .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0042] FIG. 1 is a perspective view depicting a single use ballast concrete form system 100 of the present invention. The system, as depicted, is configured to serve as a support with tilt bracket for framing for a solar panel array. However, the present invention need not be limited to support of solar panel arrays. The rear and front vertical supports 4 , 5 can be modified in a variety of ways to support any kind of structure that requires a ballast foundation. External bracing or supports such as a tilt top cord 7 can also be modified as necessary for the structure to be supported by ballast form system 100 .
[0043] While FIG. 1 depicts two vertical supports 4 , 5 , sized so that the top tilt cord 7 is at a particular angle, a wide variety of different vertical supports can be used within the concept of the present invention. Further, those supports can be of any size or height consistent with the structure to be supported and the concrete pour to be contained within form system 100 . For example, only a single vertical support can be used in some applications while more than two vertical supports can be provided for other types of applications.
[0044] Likewise, while four transverse cross braces 3 are depicted in FIG. 1 , form system 100 can be modified to accommodate a greater or lesser number of transverse cross braces to accommodate the size of the resulting ballast foundation and the size of concrete pour 2000 ( FIG. 6 ). Further, while U-shaped channels are used as vertical supports in FIG. 1 , different types of structures can be used as vertical supports to accommodate the requirements of the structure to be supported. Also, while top tilt cord 7 is provided to help support a solar panel array, other types of supports or external bracing can be used. Because of the capability, described infra., regarding the adjustments and bracing of the vertical supports 4 , 5 , external bracing (such as the use of top tilt cord 7 ) may not be necessary before providing the concrete pour 2000 .
[0045] Because the form sections 1 A, 1 B are rolled sheet steel, they are easily manufactured in different sizes to accommodate different ballast support requirements. These forms can be anywhere from 6 inches to several feet in height. The taller form arrangements will require additional internal cross bracing to properly contain the forces generated by concrete pour 2000 . Additional slots 18 are easily added during the manufacturing process of form sections 1 A, 1 B to accommodate bracing for greater heights. This allows the present form system 100 to be easily modified during the manufacturing process, and easily provided with additional internal bracing during the assembly process.
[0046] Further, the height, length and width (overall finished footprint) of the form can easily be modified by manufacturing the forms in varying lengths. This is a simple way in which to increase the strength of the resulting ballast foundation. The requirements for the load of the ballast foundation can be calculated in a manner that will permit an exact calculation as to the length of the form sections based upon a particular height of the form sections. All that need be done is that the concrete pour be applied to the very top of the form system 100 when assembled, so that the requirements of the ballast foundation are met without further adjustment at the pour site.
[0047] The benefit of this is that the ballast foundation requirements (for a particular type of load) are easily accommodated by simply adjusting the length of the form sections 1 A, 1 B during the manufacturing process. The resulting manufacturing, packing, shipping, assembly and pour steps of the process are thereby simplified substantially.
[0048] The form system 100 is preferably constituted by two substantially identical sections 1 A, 1 B, as depicted in FIG. 1 . A single form section 1 A, for example, is depicted in FIG. 2 . Form section 1 A is flat, which is the configuration in which it is manufactured, and shipped. This flat arrangement simplifies shipping because nesting and stacking of the various form sections is possible, as depicted in FIGS. 13A-13C .
[0049] Both form sections 1 A, 1 B have a sidewall 10 with a number of fastener apertures 16 (to accommodate screws), and fastener slots 18 to accommodate the flanges of the internal cross bracing 2 , 3 . Sidewall 10 is bounded on its width by transverse edges 12 A, 12 B best seen in FIG. 2 . At scored crease or pre-seam 11 , both transverse edges 12 A, 12 B are provided with a V-notch 13 A, 13 B. Each of the transverse edges 12 A, 12 B includes a lip structure 121 A, 121 B, respectively. These lip structures 121 A, 121 B can be discontinued at the V-notch structures 13 A, 13 B.
[0050] Each form section 1 A, 1 B is preferably made of rolled sheet metal. This particular kind of construction is less expensive for the type of structure shown in the drawings since the form sections 1 A, 1 B are more easily and inexpensively manufactured using rolled sheet metal. Further, this particular configuration aids in the transportation of the form sections 1 A, 1 B since these structures are easily nested and/or stacked during transportation.
[0051] The rolled sheet metal form sections 1 A, 1 B are able to withstand the pressure of a large concrete pour 2000 due to a number of factors. The sidewalls 10 are stiffened by the transverse edges 12 A, 12 B, and further by the lip structures 121 A, 121 B extending substantially perpendicular to the respective transverse edges. As a result, there is far less inclination for the sidewalls 10 to bulge outward under the stresses created by a concrete pour 2000 .
[0052] FIG. 3 depicts an enlarged view of the V-notch such as 13 A, 13 B. The subject V-notches result when a knock-out 125 (in FIG. 13B ) is removed after transport. Then, form sections 1 A, 1 B can be folded at pre-seam or crease 11 . It is relatively easy to manufacture form sections 1 A, 1 B with knock-outs 125 at each of the V-notches 13 A, 13 B to keep transverse edges 12 A, 12 B contiguous so as to remain robust during transport. The structure of the transverse edges 12 A, 12 B can be configured so that knock-outs 125 are easily removed after transport.
[0053] When a form section, such as 1 A, 1 B, is folded at the scored crease 11 , the V-notch 13 A, 13 B permits the transverse edges 12 A, 12 B, to come together as depicted in FIG. 4B and FIG. 5 . Each form section 1 A, 1 B now forms an L-shape as depicted in FIG. 5 . Because opposing ends of transverse edges 12 A, 12 B come together at the fold, they strengthen the overall structure.
[0054] Additional strength is provided to each of the form sections 1 A, 1 B by virtue of the fact that each form section forms two sides of the overall concrete form system 100 . Two such form sections 1 A, 1 B are connected together after each has been folded along crease 11 . The two intersections between the two form sections 1 A, 1 B, are connected together using corner braces 6 seen in FIGS. 1 and 11 , which are connected using screws or other fasteners to sidewalls 10 of each of the forms sections 1 A, 1 B.
[0055] Additional strength can come from ribs 17 , as depicted in FIG. 6 , to provide additional stiffness to sidewalls 10 of the form sections 1 A, 1 B. Ribs 17 are easily formed within the body of the sidewalls 10 through the rolling process used to create the overall form sections 1 A, 1 B. FIG. 6 depicts a cutaway view of parts of two parallel form sections 1 A, 1 B. Only the lower portions of the form sections are depicted, being supported by substrate 1000 . Also depicted is concrete pour 2000 , applied between the two form sections 1 A, 1 B. It is well-known that substantial force is generated by concrete pour 2000 , tending to force the form sections 1 A, 1 B outward, or otherwise distort the concrete form sections. This is addressed cumulatively by ribs 17 , transverse edges 12 A, 12 B and lip structures 121 A, 121 B. All of these, in conjunction with the corner brace 6 connecting the two L-shaped structures (one of which is depicted in FIGS. 1 and 11 ) to form the concrete form system 100 of FIG. 1 , help to address the issue of pressure generated by concrete pour 2000 . However, these expedients are not necessarily sufficient in themselves. This is especially true when fabricating large concrete foundation form systems 100 .
[0056] It is well-known that concrete structures benefit from reinforcement, such as metal bars (“rebar”) or meshes placed within the concrete pour. The current form system 100 provides such reinforcement, both for strengthening the concrete product, and holding the form system 100 together under the pressures generated by concrete pour 2000 . To provide additional bracing, longitudinal cross brace 2 is provided, along with transverse cross braces 3 . It should be noted that there are 4 transverse braces 3 in the form system 100 depicted in FIGS. 1 and 11 , and that the transverse cross braces 3 are arranged at two different heights between the sidewalls 10 of form sections 1 A and 1 B. There are also connections between the longitudinal cross brace 2 , transverse cross braces 3 , and front and rear vertical supports 4 , 5 , as seen for example in FIGS. 8A, 8B and 9 . All of these structures, which are almost entirely internal to the form system 100 , are eventually held within concrete pour 2000 , bracing the resulting concrete ballast structure.
[0057] While four transverse cross braces 3 and one longitudinal cross brace 2 are depicted in FIGS. 1 and 11 , additional bracing of both types can be provided. Further, there can be greater or fewer transverse cross braces 3 than the arrangement depicted in the Figures. The internal cross bracing 2 , 3 of the form system 100 can be arranged in a manner that will help support additional concrete reinforcing structures (not shown), such as metal mesh, rebar, and the like. However, it should be understood that the primary purpose of the longitudinal and transverse cross bracing 2 , 3 is to maintain strength and stability of the overall form system 100 during a concrete pour.
[0058] The internal cross bracing 2 , 3 is connected to opposite sidewalls 10 of form sections 1 A, 1 B, by means of slots 18 in the sidewalls of each of the form sections.
[0059] FIG. 7A depicts an end view of the arrangement of FIG. 1 . Transverse cross braces 3 are connected to opposite sidewalls 10 of parallel form sections 1 A, 1 B. In FIG. 7B flanges 31 at each end of transverse cross braces 3 extend through slots 18 in sidewalls 10 . In FIG. 7B , flanges 31 are depicted in the non-secure position. In FIG. 7C , flanges 31 have been bent against sidewall 10 , thereby securing the sidewall 10 to transverse cross brace 3 . The same can be done with respect to longitudinal cross brace 2 , which is also constructed so that flanges 21 extend from each end of longitudinal cross brace 2 . This is done in the same manner as the transverse cross braces 3 . Accordingly, the internal bracing of the form system 100 is accomplished in a simple, effective manner which holds sidewalls 10 in a fixed position, so as not to be deformed by concrete pour 2000 .
[0060] Further, as previously described, reinforcement is provided at the interfaces of the two complementary form sections 1 A, 1 B. The reinforcement is provided by corner braces 6 , which have apertures 61 aligned with apertures 16 in the sidewalls 10 of each of the form sections 1 A, 1 B. Preferably, fasteners, such as screws 65 , are used to hold the edges of the complementary form sections 1 A, 1 B together. In order for this to be accomplished, there is an incline cut 122 A, 122 B in the transverse edges at the two ends of each form section 1 A, 1 B as shown in FIG. 5 . The two incline edges of complementary form sections will butt up to each other so that complementary form sections 1 A, 1 B can fit together as depicted.
[0061] Front and rear vertical supports 4 , 5 are necessary for connection to the structure, or structures that are to be supported by the ballast foundation resulting from the concrete pour 2000 in form system 100 . It should be understood that within the context of the present invention, two vertical supports 4 , 5 (as depicted in the drawings) are not necessary. Rather, a single vertical support could be used, or more than two could also be used within the context of the present invention. The drawings depict a concrete form system 100 specifically arranged to support framing for a solar panel array. Consequently, tilt top cord 7 is also an essential part of the solar panel array support frame and at least two ballast foundations will be required for the solar panel array.
[0062] Another key feature of the present invention is the connection arrangement whereby the vertical supports 4 , 5 are connected to both the longitudinal cross brace 2 and at least one transverse cross brace 3 . This is depicted in the magnified view of FIG. 8B which depicts identical connection arrangements for both the front vertical support 5 and the rear vertical support 4 . The interrelationship between the vertical supports 4 , 5 and the longitudinal cross brace 2 and at least one transverse cross brace 3 is best depicted in FIG. 9 . Because the substrate 1000 may not be level, it is necessary to adjust the rear and front vertical supports 4 , 5 so that they are in a proper position to maintain the proper alignment of the structures (solar panel array) to be supported by those vertical supports. This means that before the concrete pour 2000 occurs, the rear and front vertical supports 4 , 5 must be adjusted. This requires latitude in the adjustability between the vertical supports 4 , 5 and the internal cross bracing 2 , 3 . This is accomplished through the use of slots, such as 25 in the longitudinal cross brace 2 , as depicted in FIG. 8B . There are also slots 35 in the transverse cross braces 3 as seen in FIG. 9 . Because of these slots in the cross braces, it is not necessary to have slots in the beams constituting rear and front vertical supports 4 , 5 .
[0063] Referring to FIGS. 8B and 9 , it is clear that each vertical support 4 , 5 is connected to at least the longitudinal cross brace 2 and at least one transverse cross brace 3 . This arrangement permits the tilt of each of the rear and front vertical supports 4 , 5 to be adjusted in two directions. The amount of tilt in each of the vertical supports 4 , 5 in the longitudinal direction is depicted in FIG. 11 . The lateral tilt (along a transverse cross brace 3 ) is depicted in FIG. 12 . As stated previously, this is achieved through slots such as 35 (in FIG. 9 ) and 25 (in FIG. 8B ).
[0064] Rear and front vertical supports 4 , 5 are constituted by U-shaped beams capable of supporting heavy loads such as solar panel arrays. The vertical support beams 4 , 5 must be carefully adjusted to the proper angle for a solar panel array. Consequently, the beams constituting the front and rear vertical supports 5 , 4 must be held in position in a manner that will allow close adjustment while accommodating the size and weight of those beams. To facilitate this process, resilient washers 55 are used with bolts and nuts to fasten the vertical supports 4 , 5 into place. The washers 55 permit a moderately tight connection between the front and rear vertical supports and the longitudinal cross brace and transverse cross braces so that the front and rear vertical supports are maintained in the proper disposition. The use of resilient washers allows sufficient controlled sliding (using slots 25 , 35 ) so that position of the front and rear vertical supports can be subjected to fine adjustment before tightening the fasteners in a permanent connection arrangement.
[0065] Once the bolts are thoroughly tightened down, the front and rear vertical supports 5 , 4 are secure, and will remain in the proper position during the concrete pour. The advantage of pouring in place is that precise adjustments can be made for the vertical supports extending from the concrete pour to accommodate existing conditions of the substrate 1000 .
[0066] Further, if necessary, with the present inventive concrete form system 100 , an unsuitable substrate surface can be accommodated with sand, gravel, or the like before the concrete pour 2000 is carried out. With the preferred open bottom of the concrete form system 100 , better accommodation can be made between the concrete form and an irregular substrate below. The connecting medium is the concrete pour 2000 , which holds the form system 100 and the substrate 1000 together by conforming to the shape and contour of the substrate. As depicted in FIG. 6 , the transverse edges next to the substrate 1000 , along with the lip structures 121 A, help hold the form system 100 to the substrate via concrete pour 2000 (which can spread to match the underlying substrate 1000 ). As a result, the base of the ballast foundation is formed in a manner that will conform to the substrate 1000 .
[0067] Additional adjustments to the front and rear vertical supports 5 , 4 can be made before the concrete pour 2000 is carried out. In particular, as depicted in FIG. 10 , the upper ends of the front and rear vertical supports 4 , 5 can be braced and positioned through the use of tilt top cord 7 . Such adjustment is particularly appropriate when the structure to be supported by the ballast foundation is a solar panel array. Adjustment and bracing of the upper ends of the front and rear vertical supports 5 , 4 is accomplished using slot 71 in the tilt top cord 7 . Preferably, such adjustment takes place before the concrete pour 2000 is carried out. However, because of the flexibility provided by the connection scheme depicted in FIG. 10 , such adjustment can be deferred until after the concrete pour 2000 has set. Preferably, the adjustment of the tilt top cord 7 to the front and rear vertical supports 5 , 4 is accomplished using nuts and bolts and resilient washers such as 72 (in FIG. 10 ) to provide a stable connection once the final adjustments have been made.
[0068] Yet another advantage of the present system 100 is that form sections 1 A, 1 B are made from rolled steel in the preferred shape depicted in FIG. 2 . The shape of form sections 1 A, 1 B facilitate easy packaging and shipping, as depicted in the transport configurations of FIGS. 13A-13C . Because these shipping packages are densely constituted (due to the substantially flat nature of form sections 1 A, 1 B, the shipping process is efficient and cost effective). Still further, because the design of the form sections 1 A, 1 B facilitate easy packaging and efficient shipment, placement at the job site is much easier.
[0069] For assembly, all that needs to be done is for the correct number of form sections 1 A, 1 B be taken from a truck and placed at the pour site. This is relatively easy due to the substantially flat nature of the form sections 1 A, 1 B. At the pour site, form sections 1 A, 1 B are bent at the various scored creases 11 , and then complementary form sections are connected together to achieve the preferred configuration as shown in FIG. 1 .
[0070] As part of the assembly process, knock-out piece 125 is removed from each of the form sections 1 A, 1 B to provide V-notches 13 A, 13 B. Easily removable knock-outs 125 are configured as part of the basic manufacturing process. These knock-outs 125 were preferrably kept in place during packing and transport in order to protect transverse edges 12 A, 12 B and to prevent unwanted bending of the form sections during transport that could weaken the form section. Ribs 17 also help maintain the structural integrity of the form sections 1 A, 1 B during handling and transport.
[0071] A key aspect of the present form system 100 is the overall simplicity and efficiency of all processes from manufacturing, to setting up the form on site, to receiving a concrete pour. To summarize, the entire process is essentially defined by the rolling process for manufacturing a product that is easily stackable for transport. Then, removing only those form sections 1 A, 1 B needed at a particular pour site, and bending the form sections 1 A, 1 B (after removing knock-outs 125 ) so that the form sections can be connected together with corner bracing 6 . The next, internal cross braces 2 , 3 are easily installed by bending the flanges 21 , 31 against the outer sidewalls 10 of the form sections 1 A, 1 B. Because of the multiple cross braces, alignment and securing of the vertical supports 4 , 5 is easily done. This last step provides precise alignment of the vertical supports for the particular substrate at the pour site. Afterwards, the concrete pour 2000 can be made for the form system 100 .
[0072] Relatively large ballast foundations can be achieved with the present form system 100 since the weight of the concrete pour 2000 is accommodated by the multiple interconnected cross bracing 2 , 3 , as well as the vertical supports 5 , 4 , which all provide substantial internal integrity capable of maintaining the sidewall 10 configuration under the force of concrete pour 2000 .
[0073] While at least one preferred embodiment has been described by way of example, the present inventive form system is not limited thereto. Rather, the present invention should be interpreted to include any and all variations, adaptations, derivations, and embodiments that would occur to one skilled in this art and with a full knowledge with the present invention.
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A ballast foundation includes a portable rolled steel enclosure formed from multiple sections and further includes internal bracing. The internal bracing is used to support an upright vertical structural member that connects to an external load (such as a frame structure for a solar array) that is supported by the ballast foundation when the enclosure is filled with concrete.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates primarily to a method and means for utilizing waste heat and more particularly to a method and means for utilizing the heat of molten slag.
2. Description of the Prior Art
In the blast furnace and steel making operation, slag is formed by the action of flux upon the gangue of ore and by the oxidation of impurities in the metal. The molten slag is separated from the molten metal and poured into ladles or cars and transported to a pit area where it is discharged for solidification and further processed for granulation or otherwise made into a friable product for non-metallurgical uses such as aggregate for concrete, macadam, and bituminous products or soil conditioners. The temperature of the molten slag when discharged from the blast furnace is approximately 3000° F. and is cooled to solidification temperature for further processing. The heat dissippated during this temperature drop is wasted in the prior art procedure of handling molten slag.
FIG. 1 diagramatically illustrates the prior art practice. The slag car is filled with molten slag during the furnace tapping and transported on tracks to slag dumps for solidification. After solidification and sufficient cooling, slag breaking equipment is used to break up the solidified slag into transportable pieces which are then collected and placed in scrap cars for transportation to a conveyor run. The conveyor run is provided with means to magnetically separate the iron content of the slag pieces. The slag pieces continue to be conveyed to a crusher mill where it is particulated for further use in the slag industry. The recovered iron is collected and returned as raw material charge. During this operation, the molten slag continues to be transported to another dump area which is being filled while the first slag dump area is cleared of solidified slag. When this operation is completed, the slag crushing equipment is moved to the now solidified second slag dump area for similar removal and crushing operation.
SUMMARY OF THE INVENTION
According to the teaching of this invention, we interpose a method and means between the source of molten slag and the solidification stage of the slag, whereby the heat of the molten slag which would otherwise be wasted, is retained and channeled to a heat utilizing device such as a steam generator, water heater or other heat utilizing device.
We accomplish the objective of our invention by discharging the molten slag from the blast furnace or metal melting crucible or any other type of molten metal processing apparatus where slag is formed as a part of the metallurgical process, into a heat refractory channel or vessel such as a Pugh car for transportation to a refractory domed basin having air passageways connected to a burner chamber or heating flues of a heat utilizing device such as a boiler, to substitute for or supplement the heat medium of the burner apparatus. The molten slag is discharged into the slag basin of my invention which has a volume capacity of approximately 10,000 tons which is substantially in excess of the volume capacity of the slag vessel used in transporting the slag to the basin. The refractory floor of the basin is slanted to a nadir, at which level, a hot metal tap hole is provided from the interior to the exterior of the basin. This tap hole is provided to recover the molten iron entrained with the molten slag and which had settled to the bottom of the basin. A slag discharge opening is provided in the wall of the basin substantially elevated in level from the iron tap hole which serves as a continuous discharge for the molten slag bath when the level of the slag bath exceeds that of the slag discharge opening. The discharge is directed into a solidification pit or water cooled conveyor means for further processing according to the prior art. We further provide a slag entrance opening in the basin of our invention through which molten slag is poured into the basin from the slag ladle cars by which means the molten slag is transported from the blast furnaces to the basin. In conjunction with the basin of our invention, we provide a rail track system comprising an elevated track running alongside the slag basin so that the slag vessel may be placed in position relative to the basin whereby the Pugh car vessel may be rotated to discharge the molten slag therein into the basin through the entrance opening, and after this operation is completed a number of times, the slag vessel, when thus emptied, may be relocated on the lower level track positioned beneath the iron tap hole. The slag vessel, now being upright, becomes a receiving vessel for the molten iron recovered from the iron tap hole after the iron has precipitated from the molten slag bath to the bottom portion of the basin. The molten iron thus recovered is returned in its molten state and transported to the steel making shops for further processing. This iron recovery vessel will occur when it is determined that there is sufficient molten iron in the basin to justify having a recovery delivery.
Thus, the method and means of our invention will not only utilize otherwise wasted heat of a high order, but also provide for the recovery of molten iron.
Other objects and advantages of our invention will become more apparent upon a more careful study of the following detailed specification and accompanying drawings which describe and illustrate a preferred embodiment of our invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a flow diagram illustrating the prior art steps in disposing of molten slag;
FIG. 2 is a cross section view of the heat exchange basin for molten slag showing its relationship with the heat utilizing devices and means for supplying the molten slag to the basin according to the practice of our invention;
FIG. 3 is a reduced side view of the heat exchange basin longitudinally sectioned at lines 3--3 of FIG. 2, showing its relationship with the slag processing apparatus in the method of this invention.
FIG. 4 is a side view of the stopper rod drive mechanism for the iron tap hole of the heat exchange basin, the stopper rod is shown in fragment;
FIG. 5 is an end view of the stopper rod drive mechanism sectioned along lines 5--5 of FIG. 4; and
FIG. 6 is a side view of the stopper rod drive mechanism sectioned along lines 6--6 of FIG. 5, showing the stopper rod in operative relation with the iron tap hole.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, particularly FIGS. 2 and 3 for the present, wherein is illustrated a preferred embodiment of this invention, numeral 10 designates generally the heat exchange reservoir basin which is constructed with refractory masonry material 12, appropriately reinforced according to conventional practice well known to the art of constructing metallurgical apparatus, having an enclosed chamber 14 the length thereof. Chamber 14 is provided with a dome 16 and floor 26 of the chamber is sloped to a low point 18. Slag outlet 20 is provided in the end wall structure of basin 10 at an elevation selected to determine level 22 of molten slag bath 24 to be retained in the basin. Iron tap outlet 25 is provided in the side wall structure of basin 10 communicating low point 18 of sloped floor 26 of basin 10 with the exterior of the basin. Slag entry opening 28 is also provided in the wall structure of basin 10 of this invention at a level above slag outlet opening 20 and at a location longitudinally distant therefrom so that the flow of molten slag from entry to discharge is maximum. The exterior of basin 10 at slag entry opening 28 is provided with runner 30 supported to extend from the basin wall and terminates adjacent rail track 32. Runner 30 receives the molten slag from slag car 34 on rail track 32. A passageway opening 36 is provided in the structure of basin 10 substantially above level 22 of molten slag bath 24, which is extended by refractory construction 38 to form a passageway 40 to communicate chamber 14 at the domed portion 16 thereof. The terminal end of structure 38 of passageway 40 is connected to a heat utilizing apparatus such as boiler apparatus 42. The basin structure of our invention is further provided with a refractory slag runner 44 at slag outlet opening 20, and is supported in any convenient manner to slope over a steel bed conveyor apparatus 46, which is cooled by water spray means 48, on which the basin discharged molten slag solidifies during the conveyor travel. At the end of the conveyor travel, the solidified slag is discharged on a second conveyor apparatus 50 by which it is transported to the hopper of a crusher mill 52 where it is particulated for other use and purposes.
Slag entry opening 28 and iron tap outlet 25 are provided on the same side of basin 10 so that double deck rail track structure 54 may be used to position slag car 34 for both openings 28 and 25 with minimum switching. Accordingly, I provide one track 32 at an elevation to raise the slag ladle car 34 above the slag entry 28 to discharge the molten slag from multiple slag car deliveries onto runner 30 and into the basin through opening 28. The other track 56 is at an elevation below iron tap outlet 25 so that slag car 34 may be positioned thereunder when empty to receive the accumulated molten iron 58 which settled from the molten slag bath 24. Iron tap outlet 25 is plugged with a tungsten plunger 60 seated into a tungsten cone 62 as shown in FIG. 6, during the slag deposit operation of this invention when iron tap outlet 25 is unplugged. A conveniently supported runner 59 is supported to channel the molten iron flow from outlet 25 to slag car 34. When the iron content of molten bath in the basin increases to a volume that will substantially fill the emptied slag car, slag car 34 is positioned on track 56 to receive the molten iron 58 from outlet 25, and the drive mechanism of stopper 60 is operated to open iron tap outlet 25 to recover the molten iron.
In this connection, the mechanism which operates stopper 60 to seat in cone 62 of iron tap outlet 25 is generally designated by the numeral 64 and is more clearly illustrated in FIGS. 4, 5 and 6. Mechanism 64 comprises stopper head 60 mounted at the distal end of rod 66 supported on carrier block 68 secured thereto by means of threaded connection 70. Carrier block 68 is provided with lateral guide plates 72 which are supported on and guided to longitudinally slide on table mounts 74. Table mounts 74 are laterally spaced apart one being on each side of carrier block 68 and forming the top side of pedestals 76 mounted on floor beam 78. The bottom side of carrier block 68 is provided with gear teeth 80 which engage gear 82 positioned therebelow supported on shaft 84. Shaft 84 is supported on bearing surfaces provided in pedestals 76 for rotation and is connected at one end thereof to motor drive 86 through speed reducers 88.
It is understood that mechanism 64 shown in FIGS. 4, 5 and 6 are illustrative only since the drive operation of stopper rod 66 may be accomplished by any convenient means and the support of mechanism 64 adjacent basin 10 at iron tap outlet 25 may be constructed to accommodate the structure of basin 10 and rail track structure 54.
In the operation of our invention, we provide heat exchange basin 10 positioned adjacent a heat utilizing apparatus 42 on one side thereof, the slag discharge and crusher apparatus' 44, 46, 50 and 52, on another side of the basin of our invention, and the track means 54 and 56 for transporting molten slag to the basin of our invention and removing accumulated iron therefrom at yet another side of basin 10 of our invention so that heat exchange basin 10 is the central point for receiving and storing a large volume of molten slag in a bath, recovering and channeling the heat of the molten slag bath to heat utilizing apparatus, recovering cooled molten slag and transporting it by conveyor apparatus 46, 50 for solidification and ultimately granulation operation in crusher mill 52, and recovery of accumulated molten iron for further use for completing the cycle of our invention.
Molten slag is discharged from furnace 90 into slag car 34 which, when filled with molten slag, is driven on tracks 32 onto upper deck rail track structure 54 and positioned thereon so that when the body of car 34 is revolved on its axis, the molten slag is discharged onto runner 30 through entrance opening 38 into basin 10. Slag car 34 is thus shuttled back and forth until a bath of molten slag 24 is formed and level 22 is reached. Further delivery of molten slag will cause the molten slag adjacent outlet opening 20 to discharge into slag runner 44. Since slag inlet 28 is longitudinally distant from outlet opening 20, the temperature of the molten slag adjacent outlet opening 20 will be sufficiently low so that upon discharge onto slag runner 44, the slag will be ready for solidification. The heat thereof being lost to the air in the chamber of the basin during the longitudinal travel of the molten slag from the entrance thereof to its discharge. The slag thus discharged falling on conveyor apparatus 46 will be solidified and further cooled and then discharged from the conveyor into the hopper of crusher apparatus 52. The air in the chamber of basin 10 being heated by the molten slag bath 24 will rise to accumulate in dome 16 of basin 10 from where it is channeled through passageway 40 into the heating chamber of boiler apparatus 42 by the flue stack current of the boiler apparatus 42.
Since we contemplate the volume of the molten slag bath 24 to be very large, on the order of 10,000 tons for example, so that the longitudinal travel of the molten slag from the entrance thereof to the discharge will be relatively slow, slag bath 24 will remain substantially quiescent allowing precipitation of the iron content entrailed in the slag to settle to the bottom of the basin. The volume amount of iron precipitated may be monitored by any convenient means known to the prior art, such as having electrodes in the wall of the basin 10 (not shown) to record when the iron has reached a level desired for removal from the basin. Empty slag car 34 may then be positioned on bottom rail track 56 beneath iron tap outlet 25 preparatory to receiving the accumulated molten iron. A runner may be provided and supported in any convenient manner to channel the molten iron from outlet 25 into the opening of car 34. Outlet 25 is plugged by means of stopper head 60 seated in cone 62 forming the mouth of iron tap outlet 25. To discharge the iron 58 from basin 10, stopper head 60, which is connected to stopper rod 66, is withdrawn from cone 62 by operation of drive mechanism 64 until the molten iron 58 is removed from basin 10 whereupon drive mechanism 64 is activated to re-seat stopper head 60 into cone 62 to close iron tap outlet 25. Car 34 is removed with its molten iron content to be discharged in shops for further processing.
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A method and means for handling molten slag from a metallurgical furnace to recover waste heat from the molten slag and molten iron entrained in the slag. The waste heat of the slag is channeled to a heat utilizing device such as a steam generator or water heater, the molten iron is collected for return to steel making shops for further processing and the cooled and solidified slag is recovered for conventional slag processing.
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FIELD OF THE INVENTION
[0001] The invention relates to a method for detecting air leakage in a tire, whether it be a fast leakage (in the case of burst tire for example) or a slow leakage (through diffusion of the air), this method including several types of measurements and of determinations in order to prevent false alarms.
BACKGROUND OF THE INVENTION
[0002] The field of the invention is the monitoring of the state of the tires as a function of the parameters of temperature and of pressure of these tires, in particular in the motor vehicle field. The tire pressure detection systems, known by the name TPMS (the initials of Tire Pressure Monitoring System) or SSPP (the initials for “Système de Surveillance de la Pression des Pneus” (in French)), comprises temperature and pressure sensors located in each tire, for example on the rim, and a central processor unit for processing the data supplied by these sensors by radio transmission.
[0003] In the event of leakage, these sensors supply the driver with information on the state of the tires with the aid of a display based on the processing of the data. Alarm means are triggered when this state corresponds to parameter values that go beyond a ceiling or fall below predefined thresholds.
[0004] In order to allow the detection of air leakages in a tire, whether they be slow or fast, various techniques for monitoring the pressure of this tire have been developed. It is known for example from patent EP 0 786 361 to monitor the inflation pressure (and/or a characteristic parameter), while safeguarding the pressure-drop measurements in several ways: by comparing the pressure data of several wheels with one another, by measuring the pressure regularly several times over different time periods, and by using a statistical method called “regression lines” calculated on the basis of these measurements. This solution requires long measurement periods and does not use the temperature compensation of the pressure measurements.
[0005] It is also known, for example from patent FR 2 871 736, that the detection of air leakages can advantageously be carried out by compensating for the value of the pressure with that of the temperature, and by comparing it with a threshold. This method makes it possible to quickly obtain results but it does not involve noise filtering and the risk of false alarms is thus not eliminated.
[0006] Patent FR 2 900 099 furthermore proposes to monitor the temperature-compensated pressure while neutralizing the alarms if the temperature variation per unit of time is less than a threshold value, provided that the pressure remains sufficient. But when the temperature does not vary very much, this approach can generate false alarms.
[0007] In general, the methods of the prior art culminate in the appearance of false alarms, despite the improvements made in the speed of detection.
SUMMARY OF THE INVENTION
[0008] The object of the invention is to avoid the risk of false alarms by supplementing the pressure and temperature measurements with a particular monitoring of their change over time. In order to do this, the fact that the pressure and temperature of a gas are a priori proportional has been taken into account, and studying the change in these two parameters as a function of time makes it possible to identify events affecting the pressure characteristics of the tire, notably: standard state (no leakage), fast leakage, slow leakage, braking, acceleration.
[0009] More precisely, the subject of the present invention is a method for detecting air leakage from a tire, wherein two parameters of temperature and of pressure of the air inside the tire are measured at successive moments separated by a measurement period, the measurements of the two parameters are referenced. This method consists in converting the referenced pressure measurements into values of a magnitude calibrated in temperature called converted pressure, in monitoring for at least two sampling periods, multiples of the measurement period, the change in a difference called significant at each measurement moment between the values of the converted pressure and the referenced temperature, these variations in the parameters being established over one and the same processing period greater than or equal to the highest sampling period, in determining slopes of variation in the significant difference for each sampling over the processing period and, when the slope of variation in the difference remains negative for at least one sampling over the processing period, in estimating that an air leakage is detected with a fast or slow level of flow rate associated with threshold values for the sampling period(s) in question.
[0010] According to preferred embodiments:
the number of samplings is equal to three with a first period sampling equal to the measurement period and the other two sampling periods equal to multiples of the measurement period; the pressure measurements and temperature measurements of the air of each of the tires of a vehicle are supplied by sensors according to the measurement period, transmitted to a central processor unit at the moments set by the measurement period, the measurements corresponding to the moments set by each sampling period, called sampling measurements, are selected on the basis of the measured values, stored in a memory when the vehicle starts and is running, and processed in the central unit in order to supply the slopes of variation in the significant difference; for each tire, the parameters are referenced on the basis of the values of temperature and of pressure minus reference measurements taken on startup, and the conversion of the pressure into temperature is determined by the application of a coefficient equal to the ratio between a reference temperature measurement and a reference pressure measurement to the values taken by the converted pressure; the slope of variation in the significant difference is established, for each sampling, by an average variation in this significant difference over a number of consecutive sampling periods defining the processing period; the number of periods taken into account is sufficient to confirm the reproducibility of the difference variation slope values with the aid of at least two determined threshold values, an amplitude threshold value and a period confirmation threshold value; for each sampling in standard running conditions, during a period at least equal to the period confirmation threshold, the slope is substantially zero in the event of no air loss, greatly negative in the event of fast leakage for at least the shortest period sampling, and constant for at least the longest period sampling, after a drop at least equal to the amplitude threshold.
[0017] One of the advantages of the invention is that it dispenses with noise and other decorrelations of measurements between the temperature and the pressure by using at least one sampling with a sufficiently long period.
[0018] According to advantageous features:
the measurements of the parameters are smoothed over time; the number of samplings is equal to two, the first sampling having a period equal to the measurement period and the second a period chosen between 2 to 6 times the measurement period; the number of samplings is equal to three, the first sampling having a period equal to the measurement period, the second a period chosen between 2 to 4 times the measurement period, and the third a period chosen between 5 and 12 times the measurement period; the number of samplings is equal to three, the first sampling having a period equal to the measurement period, the second chosen between 2 to 6 times the measurement period and the third a period between 7 and 12 times the measurement period; the measurement period is chosen between 15 seconds and one minute.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Other objects, features and advantages of the present invention will appear on reading the following nonlimiting description with reference to the appended figures which represent, respectively:
[0025] FIG. 1 , a functional diagram between each wheel unit and the central processor unit of the measurements supplied;
[0026] FIG. 2 , a diagram of the main steps in monitoring the pressure of each tire and of detecting leakages;
[0027] FIG. 3 a , a diagram of the change over time of the pressure and temperature parameters, in association with the speed of a tire which illustrates a case of no leakage;
[0028] FIG. 3 b , in the same case as that of the preceding figure, a detailed diagram of change over time in the variations in the temperature and in the significant difference, and in the variations in the slopes p(n) of the significant differences for three samplings;
[0029] FIG. 4 a , a diagram of the change over time in the parameters of a tire, in association with its speed, and characterizing a situation of fast leakage;
[0030] FIG. 4 b , in the same situation of fast leakage ( FIG. 4 a above), the detailed diagram of change in the magnitudes expressed for FIG. 3 b , with reiteration of an alarm confirmation;
[0031] FIG. 5 a , a diagram of change over time in the parameters of a tire, in association with its speed, which reveals a situation of slow leakage, and
[0032] FIG. 5 b , in the same slow leakage situation ( FIG. 5 a above), the detailed diagram of change in the magnitudes expressed for FIG. 3 b or 4 b , with reiteration of an alarm confirmation.
DETAILED DESCRIPTION OF THE INVENTION
[0033] The functional diagram of FIG. 1 illustrates the transmission of the data of the air pressure parameters P and temperature parameters T of each tire of a vehicle. The data are measured by a pressure sensor 101 and a temperature sensor 102 of each wheel unit 100 arranged in the tire, on the wheel rim. The data are sent by radio frequency to a central processor unit 110 at successive moments, set according to the measurement period of the sensors. In the example, the measurement period is equal to 1 minute.
[0034] The measurements of the parameters P and T taken at moments set by each sampling period, called sampling measurements, are selected from the data transmitted on startup of the vehicle and then during its journey. The sampling measurements of the parameters P and T are then processed in the unit 110 by a processor 112 , in connection with a memory 114 and a value comparator 115 . This comparator compares the values of variations in significant differences, determined on the basis of the sampling measurements and of the data supplied by the processor 112 , as explained below, with threshold values S 1 and threshold values S 2 also stored in the memory 114 . On leaving the comparator 115 , an estimation confirmation signal E 1 , E 2 , E 3 , etc. may or may not be transmitted to an alarm supplier 120 which is fitted, for example, to the vehicle dashboard.
[0035] The data of the pressure parameters P and temperature parameters T as measured successively by the sensors and the sampling measurements for each sampling are processed in the unit 110 in the following manner, with reference to the main steps of the diagram of FIG. 2 . The measurements of the parameters P and T taken in step 1 are first referenced (step 2 ) by difference with reference values, respectively P ref and T ref , supplied by the sensors in step 1 on startup of the vehicle. The differences P−P ref and T−T ref thus referenced are marked ΔP and ΔT and respectively called referenced pressure and referenced temperature.
[0036] The referenced pressure data ΔP are advantageously converted into data of a magnitude depending only on the temperature ΔP T (step 4 ). To do this, a compensation coefficient KT is defined by the relation T ref /P ref (step 3 ) based on the measurements T ref and P ref (step 1 ). The converted pressure ΔP T is then obtained by application of the coefficient KT: ΔP T =KT×ΔP. The referenced data ΔT and ΔP T are uniform magnitudes of temperature dimensioned according to the same unit (degrees Celsius).
[0037] Then (step 5 ) a significant difference ΔQ between the successive referenced values of converted pressure 66 P T and referenced temperature ΔT (ΔQ=ΔP T −ΔT) is generated and stored. The significant difference also has a temperature dimension. Moreover, the variations in this difference ΔQ for two consecutive sampling measurements, with reference to a sampling of period n, are determined, averaged and stored. Its change is then characterized by a slope of variation p(n) which again has a temperature dimension.
[0038] For each setting of sampling period n (step 6 ), three samplings in the example of period n 1 equal to 1 min, n 2 equal to 5 min and n 3 equal to 10 min are used. A slope p(n) is thus generated for each period n. The monitoring of three estimation magnitudes: significant differences ΔQ, referenced temperatures ΔT and slope p(n) for three settings in the example (n=1, 5 and 10 min) will then make it possible to supply estimations E 1 , E 2 , E 3 , etc. (step 7 ) on states of leakage of the tire—respectively: no leakage, fast air leakage, slow air leakage—, as a function of the data and of threshold values of amplitude S 1 and of period S 2 that are stored. As will appear in the situations described below, up to three pairs of threshold values of amplitude and of confirmation in period S 1 a, S 1 b, S 1 c and S 2 a, S 2 b, S 2 c are designed to detect, respectively, fast leakages, during an estimation E 2 , and slow leakages by an estimation E 3 . All the detection thresholds are applied in parallel during the processing period.
[0039] With reference to FIG. 3 a , the diagram illustrates the direct change in the measurements over time “t” on a first path, of the parameters of pressure P 1 and of temperature T 1 of a tire, in relation with the speed v 1 (in km/h) of the vehicle. In the situation illustrated, the pressure P 1 increases with the slow increase in the temperature T 1 , according to the law of proportion of ideal gases with a constant volume “V” (P 1 V=nRT 1 , where n=the number of moles of the gas, R being the constant of ideal gases).
[0040] The instantaneous speed v 1 of the vehicle shows many oscillations reflecting more or less long phases of acceleration and deceleration, for example around 1100 seconds where the slope of the speed v 1 increases and decreases rapidly with a peak at more than 140 km/h.
[0041] The utilization of the data of this diagram is illustrated by that of FIG. 3 b which shows the variations, with a scale of the temperatures T that is ten times as large, of the estimation magnitudes: ΔT 1 , ΔQ 1 and of the slope p(n) of variations in the significant difference ΔQ 1 for the three sampling period settings (n 1 =1 min, n 2 =5 min and n 3 =10 min) of the example. These magnitudes are determined on the basis of the data of the parameters T 1 and P 1 as explained above with reference to steps 6 and 7 of FIG. 2 . The diagram illustrates the particular variations in these magnitudes in connection with specific running conditions, in the following manner:
the even rise in the referenced temperature ΔT 1 up to the peak ΔTs falls sharply from the stopping of the vehicle (or the resetting of the data processing) at a moment situated approximately 1400 s after running begins; the significant difference ΔQ 1 also goes through a maximum ΔQm around 1100 seconds, corresponding to the acceleration/deceleration phase of greatest amplitude (identified with reference to FIG. 3 a ); the curve of change in the slope p 1 (n 1 =1 min) is “affected by interference” which results in oscillations, in particular at the time of the acceleration around 1100 seconds, while the other slopes p 1 (n 2 ) and p 1 (n 3 ) (where n 2 =5 min and n 3 =10 min) of the other two longer measurement period settings are substantially more smoothed over a large central portion.
[0045] Therefore, it appears that the significant difference ΔQ 1 increases slowly with the referenced temperature ΔT 1 and that the slopes of variation in the significant difference p 1 (n 1 ), p 1 (n 2 ) and p 1 (n 3 ) remains substantially constant for the three sampling period settings decorrelated from the variations in the other estimation magnitudes, ΔT 1 and ΔQ 1 . These substantially constant changes in the slopes p 1 (n) of the variations in the significant difference for three different periods make it possible to estimate—estimation El—that no air leakage has appeared during the processing period for the given journey, which is the case.
[0046] With reference to FIG. 4 a , the diagram illustrates the change in direct measurements of the parameters P 2 and T 2 of a tire, also in connection with the speed v 2 (in km/h) of the vehicle, over a time period “t” of approximately 2500 seconds covering a second journey.
[0047] In this diagram, it appears that the pressure P 2 rises slowly with the temperature T 2 up to a point P 2 m, and then decreases from a moment approximately equal to 1700 seconds, with a regular decrease of slope approximately equal to −18 kPa/min. The temperature T 2 continues to rise slowly, whereas the speed of the vehicle v 2 marks two stops, around 400 seconds and around 1700 seconds.
[0048] The detailed diagram of FIG. 4 b shows, on a scale of temperature T that is enlarged 10 times (as above with reference to FIG. 3 b ), the three estimation magnitudes: ΔT 2 , ΔQ 2 and slopes p 2 (n) of the variations in the significant difference ΔQ 2 , for the same sampling period settings “n” as before:
n 1 =1 min, n 2 =5 min and n 3 =10 min.
[0050] Whereas the curve of referenced temperature ΔT 2 rises slowly, as it can be predicted, the curve of significant difference ΔQ 2 shows a “sharp” decrease to the negative values, from the moment 1700 seconds, corresponding to the beginning of the decrease in pressure at the point P 2 m ( FIG. 4 a ).
[0051] The slopes p 2 (n) show falls in value that are staged over time because of the increasing sampling periods: the slope p 2 (n 1 ) with the shortest period (n 1 =1 min) falls first at approximately 1700 seconds, the slope p 2 (n 2 ) with a medium period (n 2 =5 min) falls twice at approximately 1800 seconds and then at approximately 2200 seconds, and the slope p 2 (n 3 ) with the longest period (n 3 =10 min) falls at approximately 2200 seconds.
[0052] Also with reference to FIGS. 1 and 2 , the falls in slope p(n) are compared with the aid of the comparator 115 at thresholds of amplitude S 1 a and of period confirmation S 2 a stored in the memory 114 in order to be adopted in an estimate of fast air leakage E 2 . S 1 a is equal to −100° C. and S 2 a equal to +120 seconds in the example. In these conditions, during the time period of 500 seconds—devoted to the estimation E 2 —seven fast leakage signals E 2 i are triggered by the alarm 120 . The first six are triggered by the drop in the slope p 2 (n 1 ) and the last by the drop in the slope p 2 (n 2 ), while the drop in the slope p 2 (n 1 ) is not confirmed because it is not maintained over at least the period of S 2 a (in this instance set to 120 seconds). In general, the threshold S 2 a is equal to a number of measurement periods that is small but sufficient to allow a fast air leakage to be detected. This FIG. 4B therefore illustrates clearly a case of fast air leakage with a negative slope p(n).
[0053] With reference to FIG. 5 a , the diagram illustrates the change in the direct measurements of the parameters P 3 and T 3 of a tire, still in connection with the speed v 3 (in km/h) of the vehicle, over a wide processing range “t” of approximately 7000 seconds (or approximately 2 hours) covering a third journey.
[0054] In this diagram, it appears that the pressure P 3 reduces slowly (approximately 0.3 Pa/min), the temperature T 3 is virtually constant and the speed of the vehicle v 3 is maintained at 150 km/h, with several sharp decelerations followed by fast accelerations in order to return to the 150 km/h level. The journey appears to be a run on a freeway.
[0055] The detailed diagram of FIG. 5 b shows, on the larger scale of temperature already used for the diagrams of FIGS. 3 b and 4 b (the temperature scale T multiplied by 10), the change in the estimation magnitudes ΔT 3 , ΔQ 3 and slopes p 3 (n) of variation in the significant difference ΔQ 3 , for the same sampling period settings “n” as before: n 1 =1 min, n2=5 min and n3=10 min.
[0056] More precisely, the referenced temperature ΔT 3 varies hardly at all after a startup phase with a duration equal approximately to 2000 seconds and the significant difference ΔQ 3 has a steady decrease to the negative values, after this same startup phase, because of the reduction in pressure P 3 ( FIG. 5 a ). The slopes p 3 (n 1 ), p 3 (n 2 ), p 3 (n 3 ) of variations in significant differences are greatly affected by interference but retain a substantially constant mean value.
[0057] However, the slope p 3 (n 3 ) adopts negative values after the startup phase, namely from approximately 2400 seconds. The slope p 3 (n 3 ) then fulfils the threshold criteria S 1 c and S 2 c—of amplitude and period for a number of periods that is sufficient to qualify the leakage as slow: in the example, S 1 c=−10° C. and S 2 c=1800 seconds. In the period of development of an estimation E 3 , five slow leakage signals E 3 i are then triggered by the alarm 120 ( FIG. 1 ) in the example illustrated. This figure therefore illustrates the case of a slow leakage.
[0058] The invention is not limited to the exemplary embodiments described and shown. Thus, it is possible to temporarily increase, while running, the duration of the confirmation phase during variations in high temperature in order to prevent false alarms: running on a snow-covered road or in a rain storm, or after washing.
[0059] Moreover, the number of detection thresholds is not limited to two pairs of values but it is possible to provide other thresholds characteristic of decorrelations between the variations in the referenced temperature ΔT, the significant difference ΔQ and/or the slopes p(n), reflecting particular conditions arising during the journey: sudden cooling or increase in temperature, change of altitude, etc.
[0060] Moreover, it is possible to modify, while running, the period settings by modifying the number of measurement periods for each sampling period.
[0061] As a variant, it should be noted that it is possible to express the temperature as a function of the pressure (ΔT P ,) and not the pressure as a function of the temperature (ΔP T ) as explained in the exemplary embodiment chosen above. Specifically, the temperature varies less rapidly, which makes it possible to smooth the curve that is obtained. In this case, for each tire, the parameters are referenced (ΔP, ΔT P ) on the basis of the values of pressure (P) and of temperature (T) minus reference measurements (P ref , T ref ) taken on startup, and the conversion of the temperature into pressure (ΔT P ) is determined by the application of a coefficient (K′P) equal to the ratio between a reference pressure measurement (P ref ) and a reference temperature measurement (T ref ) to the values taken by the converted temperature (ΔT P ).
[0062] Moreover, the invention applies to any inflated tire without being limited to motor vehicles.
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In order to avoid the risk of false alarms by supplementing the pressure and temperature measurements with a particular monitoring of their change over time, there is proposed a method which includes: converting referenced pressure measurements (ΔP) into values of a magnitude calibrated in temperature called converted pressure (ΔP T ); monitoring for at least two sampling periods (n 1, n 2 ) multiples of a measurement period, the change in a difference called significant (ΔQ) at each measurement moment between the values of the converted pressure (ΔP T ) and a referenced temperature (ΔT). The slope (p(n)) of these variations is monitored and signifies either an absence of leakage or an air leakage at a fast or slow rate.
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FIELD OF THE INVENTION
[0001] The present invention relates to conopeptides and analogs thereof that can control or otherwise affect behavior of voltage-gated sodium channels, such as Nav 1.1-1.7 channels. Many conopeptides are found in minute amounts in the venom of cone snails (genus Conus ). As such, the present invention involves the fields of chemistry, biochemistry, molecular biology, and medicine among others.
BACKGROUND OF THE INVENTION
[0002] All publications, patents, and other materials used herein are incorporated by reference.
[0003] The venom of marine gastropods in the genus Conus has yielded numerous structurally and functionally diverse peptidic components. The increasing variety of bioactive peptides identified in cone snail venoms has provided insight into the seemingly endless variety of directions taken by Conus species in evolving neuroactive molecules to suit their diverse biological purposes.
[0004] The bioactive peptides in Conus (“conopeptides”) are classified into two broad groups: the non-disulfide-rich and the disulfide-rich. The latter are conventionally called conotoxins. The non-disulfide-rich class includes conopeptides with no cysteines (contulakins and conorfamides), and conopeptides with two cysteines forming a single disulfide bond (conopressins and contryphans). The conopeptides that comprise the disulfide-rich class have two or more disulfide bonds. Among the major classes of molecular targets identified for these structurally diverse conopeptides are members of the voltage-gated and ligand-gated ion channel superfamilies.
[0005] The structure and function of a number of these peptides have been determined. Three classes of targets have been elucidated: voltage-gated ion channels; ligand-gated ion channels, and G-protein-linked receptors.
[0006] Conus peptides which target voltage-gated ion channels include those that delay the inactivation of sodium channels, as well as blockers specific for sodium channels, calcium channels and potassium channels. Peptides that target ligand-gated ion channels include antagonists of NMDA and serotonin receptors, as well as competitive and noncompetitive nicotinic receptor antagonists. Peptides which act on G-protein receptors include neurotensin and vasopressin receptor agonists. The pharmaceutical selectivity of conotoxins is at least in part defined by specific disulfide bond frameworks combined with hypervariable amino acids within disulfide loops.
[0007] Voltage-gated sodium channels are found in all excitable cells including myocytes of muscle and neurons of the central and peripheral nervous system. In neuronal cells, sodium channels are primarily responsible for generating the rapid upstroke of the action potential. In this manner sodium channels are essential to the initiation and propagation of electrical signals in the nervous system. Proper and appropriate function of sodium channels is therefore necessary for normal function of the neuron. Consequently, aberrant sodium channel function is thought to underlie a variety of medical disorders including epilepsy, arrhythmia, myotonia, and pain.
[0008] There are currently at least nine known members of the family of voltage-gated sodium channel (VGSC) alpha subunits. Names for this family include SCNx, SCNAx, and Navx.x. The VGSC family has been phylogenetically divided into two subfamilies Nav1.x (all but SCN6A) and Nav2.x (SCN6A). The Nav1.x subfamily can be functionally subdivided into two groups, those which are sensitive to blocking by tetrodotoxin (TTX-sensitive or TTX-s) and those which are resistant to blocking by tetrodotoxin (TTX-resistant or TTX-r).
[0009] The Nav1.7, alternatively written as NaV1.7, (PN1, SCN9A) VGSC is sensitive to blocking by tetrodotoxin and is preferentially expressed in peripheral sympathetic and sensory neurons. The SCN9A gene has been cloned from a number of species, including human, rat, and rabbit and shows about 90% amino acid identity between the human and rat genes.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIGS. 1A and 1B show concentration response curves for C. geo 1 analogs against hNaV1.7. FIG. 1A : IC 50 value for the internally-truncated synthetic peptide C. geo 1[des-Ser34] was calculated as 1.8 μM. FIG. 1B : Concentration-response curves were repeated on the full-length peptide, in addition to the analog containing the amino-butyric acid isosteric replacement at position 24 ( C. geo 1[C24Abu]).
DETAILED DESCRIPTION
[0011] In describing and claiming the present invention, the following terminology will be used in accordance with the definitions set forth below.
[0012] The singular forms “a,” “an,” and, “the” can include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a peptide” can include reference to one or more of such peptides, and reference to “the analog” can include reference to one or more of such analogs.
[0013] As used herein, “subject” refers to a mammal that may benefit from the administration of a composition or method according to aspects of the present disclosure. Examples of subjects include humans, and may also include other animals such as horses, pigs, cattle, dogs, cats, rabbits, and aquatic mammals.
[0014] As used herein, the term “peptide” may be used to refer to a natural or synthetic molecule comprising two or more amino acids linked by the carboxyl group of one amino acid to the alpha amino group of another. A peptide of the present invention is not limited by length, and thus “peptide” can include polypeptides and proteins. Amino acid sequences are written left to right in amino to carboxy orientation, respectively.
[0015] As used herein, the term “isolated,” with respect to peptides, refers to material that has been removed from its original environment, if the material is naturally occurring. For example, a naturally-occurring peptide present in a living animal is not isolated, but the same peptide, which is separated from some or all of the coexisting materials in the natural system, is isolated. Such isolated peptide could be part of a composition and still be isolated in that the composition is not part of its natural environment. An “isolated” peptide also includes material that is synthesized or produced by recombinant DNA technology or that is synthetically created.
[0016] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as is commonly understood by one of skill in the art to which the invention belongs.
[0017] As used herein, the term “substantially” refers to the complete or nearly complete extent or degree of an action, characteristic, property, state, structure, item, or result. For example, an object that is “substantially” enclosed would mean that the object is either completely enclosed or nearly completely enclosed. The exact allowable degree of deviation from absolute completeness may in some cases depend on the specific context. However, generally speaking the nearness of completion will be so as to have the same overall result as if absolute and total completion were obtained. The use of “substantially” is equally applicable when used in a negative connotation to refer to the complete or near complete lack of an action, characteristic, property, state, structure, item, or result. For example, a composition that is “substantially free of” particles would either completely lack particles, or so nearly completely lack particles that the effect would be the same as if it completely lacked particles. In other words, a composition that is “substantially free of” an ingredient or element may still actually contain such item as long as there is no measurable effect thereof.
[0018] As used herein, the term “about” is used to provide flexibility to a numerical range endpoint by providing that a given value may be “a little above” or “a little below” the endpoint without affecting the desired result.
[0019] As used herein, a plurality of items, structural elements, compositional elements, and/or materials may be presented in a common list for convenience. However, these lists should be construed as though each member of the list is individually identified as a separate and unique member. Thus, no individual member of such list should be construed as a de facto equivalent of any other member of the same list solely based on their presentation in a common group without indications to the contrary.
[0020] Concentrations, amounts, and other numerical data may be expressed or presented herein in a range format. It is to be understood that such a range format is used merely for convenience and brevity and thus should be interpreted flexibly to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly recited. As an illustration, a numerical range of “about 1 to about 5” should be interpreted to include not only the explicitly recited values of about 1 to about 5, but also include individual values and sub-ranges within the indicated range. Thus, included in this numerical range are individual values such as 2, 3, and 4 and sub-ranges such as from 1-3, from 2-4, and from 3-5, etc., as well as 1, 2, 3, 4, and 5, individually.
[0021] This same principle applies to ranges reciting only one numerical value as a minimum or a maximum. Furthermore, such an interpretation should apply regardless of the breadth of the range or the characteristics being described.
DETAILED DESCRIPTION
[0022] The present disclosure provides novel peptides showing activity in blocking sodium channels, including various associated compositions and methods. More particularly, these peptides block at least voltage-gated sodium channels. Much of the description herein pertains to NaV1.7 sodium channels; however it is understood that the present scope includes any sodium channels, voltage-gated or otherwise, that are affected by the present peptides. It is noted that these peptides are derived from the venom of Conus geographus snails using a combination of venom fractionation, sequencing, cloning and transcriptomics, and that the present scope additionally includes the naturally occurring peptides, completely or partially synthesized peptides, and related analogues thereof.
[0023] The present peptides can be identified by isolation from Conus venom. Additionally, the present peptides can be identified using recombinant DNA techniques by screening cDNA libraries of various Conus species using conventional techniques such as the use of reverse-transcriptase polymerase chain reaction (RT-PCR) or the use of degenerate probes. Primers for RT-PCR are based on conserved sequences in the signal sequence and 3′ untranslated region of the propeller peptide genes. Clones that hybridize to these probes can be analyzed to identify those which meet minimal size requirements, i.e., clones having approximately 300 nucleotides (for a precursor peptide), as determined using PCR primers that flank the cDNA cloning sites for the specific cDNA library being examined. These minimal-sized clones can then be sequenced. The sequences are then examined for the presence of a peptide having the characteristics noted above for peptides. The biological activity of the peptides identified by this method is tested as described herein, in U.S. Pat. No. 5,635,347, or conventionally in the art.
[0024] The present peptides are sufficiently small to be chemically synthesized by techniques well known in the art. The peptides are synthesized by a suitable method, such as by exclusively solid-phase techniques (Merrifield solid-phase synthesis), by partial solid-phase techniques, by fragment condensation or by classical solution couplings. Suitable techniques are exemplified by the disclosures of U.S. Pat. Nos. 4,105,603; 3,972,859; 3,842,067; 3,862,925; 4,447,356; 5,514,774; 5,591,821 and 7,115,708, each incorporated herein by reference. In one non-limiting aspect, a solid peptide synthesis protocol can be optimized using a low preloaded Wang resin in combination with pseudoproline Fmoc-Tyr(tBu)-Thr(ψ Me,Me pro)-OH to obtain enhanced purity for the crude linear products.
[0025] Various of the peptides described herein can also be obtained by isolation and purification from specific Conus species using the techniques described in U.S. Pat. Nos. 4,447,356; 5,514,774 and 5,591,821, the disclosures of which are incorporated herein by reference. The peptides described herein can also be produced by recombinant DNA techniques well known in the art.
[0026] Peptides produced by chemical synthesis or recombinant DNA techniques can be isolated, reduced if necessary, and oxidized to form disulfide bonds. One method of forming disulfide bonds is the air oxidation of the linear peptides for prolonged periods under cold room temperatures or at room temperature. This procedure results in the creation of a substantial amount of the bioactive, disulfide-linked peptides. The oxidized peptides can be fractionated using reverse-phase high performance liquid chromatography (HPLC) or the like, to separate peptides having different linked configurations. Thereafter, either by comparing these fractions with the elution of the native material or by using an assay, the particular fraction having the correct linkage for maximum biological potency can be determined. However, because of the dilution resulting from the presence of other fractions of less biopotency, a somewhat higher dosage may be beneficial.
[0027] Muteins, analogs, or active fragments of the peptides described herein are also contemplated. Derivative muteins, analogs or active fragments of the present peptides can be synthesized according to known techniques, including conservative amino acid substitutions, such as outlined in U.S. Pat. No. 5,545,723 (see particularly col. 2, line 50 to col. 3, line 8); U.S. Pat. No. 5,534,615 (see particularly col. 19, line 45 to col. 22, line 33); and U.S. Pat. No. 5,364,769 (see particularly col. 4, line 55 to col. 7, line 26), each incorporated herein by reference.
[0028] In one aspect of this invention, a novel peptide having 7 cysteine residues is provided, where the peptide has a sequence of X 1 X 2 C X 4 X 5 X 6 X 7 X 8 X 9 C X 11 X 12 X 13 X 14 X 15 X 16 CCX 19 X 20 X 21 C X 23 C 24 X 25 X 26 X 27 X 28 Ĉ (SEQ ID 033). It is noted that X 1-2 , X 4-9 , X 11-16 , X 19-21 , X 23 , and X 25-28 can each independently be any amino acid that allows functionality of the resulting peptide, and that the spacing of the cysteine residues is preserved. C 24 is cysteine or a substituted cysteine, and ̂ is a carboxylated C-terminus, as is discussed further herein.
[0029] In one aspect, X 27 can be lysine or glycine. In another aspect, X 6 can be hydroxyproline or alanine. In yet another aspect, X 23 can be aspartic acid, gamma-carboxyglutamic acid, or asparagine. In a further aspect, X 25 can be tyrosine or aspartic acid.
[0030] In one aspect, this invention provides peptides having a sequence GWCGDOGATC GKLRLYCCSG FCX 23 C 24 X 25 TKTC-X 30 ̂ (SEQ ID 001), where O is hydroxyproline, X 23 is aspartic acid, asparagine, or carboxyglutamic acid, C 24 is cysteine or a substituted cysteine, X 25 is tyrosine or aspartic acid, X 30 is a peptide from 0 to 6 amino acids, and ̂ is a carboxylated C-terminus. In one aspect, the peptide can be an isolated peptide. In another aspect, the peptide can be a synthetic peptide. Numerous synthesis protocols and techniques are known, and any such technique that can be utilized to generate synthetic peptides is considered to be within the present scope. For example, in one aspect solid peptide synthesis can be utilized.
[0031] A variety of substitutions and/or variations are contemplated that allow variability in the degree of modulation of sodium channels. The following substitutions and/or variations are thus intended to be merely exemplary of embodiments of this invention, and should not be seen as limiting. Table 1, for example, shows non-limiting examples of peptide analogs obtained in the context of this invention to demonstrate a few of the contemplated moieties. C 24 from SEQ ID 001 is a free-thiol substituted cysteine in some embodiments. C 24 is replaced by an alternative amino acid residue in other embodiments.
[0032] In other embodiments the C 24 residue of SEQ ID 001 forms a dimer with a variety of useful peptides. In one aspect, for example, the dimer can be a second peptide according to SEQ ID 001, as is shown in Table 1 as SEQ ID 015. It is noted that the second peptide can have the exact sequence of SEQ ID 001, a substantially similar sequence at to SEQ ID 001, or any degree of modification that allows beneficial functionality of the peptide.
[0033] In other embodiments, C 24 is reversibly modified with a molecule through a disulfide linkage. Numerous disulfide linkages are known, and any such linkage that can be utilized that allows sufficient functionality of the peptide is considered to be within the present scope. Non-limiting examples of such substitution molecules can include glutathione, cysteine, cysteamine, DTNB, selenocysteine, selenoglutathione, and any product of a reaction of C 24 with an alkanethiosulfonate reagent or a thiosulfate reagent, and combinations thereof. A few examples from Table 1 showing reversible substitutions include SEQ ID 003, SEQ ID 008, SEQ ID 009, SEQ ID 011, SEQ ID 012, SEQ ID 013, SEQ ID 015, SEQ ID 019, SEQ ID 020, and SEQ ID 021.
[0034] In other aspects, C 24 is irreversibly substituted with a molecule. Numerous irreversible substitutions are contemplated, and any such substitution that allows sufficient functionality of the peptide is considered to be within the present scope. Non-liming examples of irreversibly substituted molecules include acetamidomethyl, products of a reaction of C 24 with maleimides, vinyl sulfones and related α,β-unsaturated systems, β-haloethylamine, α-halocarbonyls, or a combination thereof. On example from Table 1 showing irreversible substitutions is SEQ ID 014.
[0035] In another aspect, a peptide is provided having a sequence of SEQ ID 001, wherein X 23 is aspartic acid, C 24 is an un-substituted cysteine, and X 25 is tyrosine, where such a sequence is GWCGDOGATC GKLRLYCCSG FCDCYTKTC-X 30 ̂ (SEQ ID 022). In a more specific aspect, X 30 can be SEQ ID 002, where the resulting peptide would be GWCGDOGATC GKLRLYCCSG FCDCYTKTCK DKSSA (SEQ ID 023).
[0036] In a further aspect, a peptide is provided having a sequence of SEQ ID 001, wherein X 23 is aspartic acid, C 24 is substituted with cystamine, and X 25 is tyrosine. In a more specific aspect, X 30 can be SEQ ID 002, where the resulting peptide can have a sequence of SEQ ID 011.
[0037] It is also noted that in some aspects, a peptide according to aspects of the present invention can further include a label, such as, for example, a fluorescent label. Such a labeled peptide can be used to probe libraries, such as small molecule libraries.
[0000]
TABLE 1
rNa v 1.7
hNa V 1.7
% block
IC 50 or
peptide
Peptide
Sequence
% block
concentration
C.geo1[1-35] SEQ ID 003
1.4 μM
70%
C.geo1[C24Abu] SEQ ID 004
>10 μM
20% (33 μM)
C.geo1[C24S] SEQ ID 005
>10 μM
20% (33 μM)
C.geo1[C24K] SEQ ID 006
>10 μM
20% (33 μM)
C.geo1[C24E] SEQ ID 007
>10 μM
15% (33 μM)
C.geeo1[K27G] SEQ ID 008
1.6 μM
60% (33 μM)
C.geo1[O6A] SEQ ID 009
>10 μM
60% (33 μM)
C.geo1[desGSH] SEQ ID 010
71 nM
70%
C.geo1[cystamine] SEQ ID 011
72 nM
70%
C.geo1[cystine] SEQ ID 012
925.8 nM
not tested
C.geo1[DTNB] SEQ ID 013
>3 μM
not tested
C.geo1[C24Cys(Acm)] SEQ ID 014
>1 uM
70% (33 μM)
C.geo1[dimer] SEQ ID 015
437 nM
70% (30 μM)
C.geo1[C24D-Cys] SEQ ID 016
2.86 μM
not tested
C.geo1[C24HoCys] SEQ ID 017
1.5 μM
not tested
C.geo1[C24Pen] SEQ ID 018
>1 μM
not tested
C.geo1[D23Gla; cystamine] SEQ ID 019
77.9% block at 3 μM
not tested
C.geo1[D23N; cystamine] SEQ ID 020
23.8% block at 300 nM
not tested
C.geo1[Y25D; cystamine] SEQ ID 021
16.2% block at 300 nM
not tested
[0038] It is noted that a variety of oxidative folding methods can be utilized to generate peptide analogs, and that any useful folding technique is considered to be within the present scope. Various folding methods utilized to generate the exemplary peptides of Table 1 can be as follows: folding in the presence of a 1:1 mixture of GSSH:GSH can be used to generate SEQ IDs 003-009 and SEQ ID 014; folding in the presence of cystamine can be used to generate SEQ ID 011 and SEQ IDs 019-021; folding in the presence of cystine can be used to generate SEQ ID 012; and folding in the presence of copper ions can be used to generate SEQ ID 010 and SEQ IDs 016-018. As other examples, SEQ ID 015 and SEQ ID 013 can be prepared from SEQ ID 010 by reacting it with DMSO and Ellman's reagent (DTNB) respectively. Peptides can subsequently be purified by, for example, RP HPLC, and masses can be confirmed by MALDI mass spectrometry.
[0039] In another aspect of the present invention, a peptide is provided having a sequence of DWCGDAGDAC GTLKLRCCSG LCNQYSGTCTĜ (SEQ ID 24), where ̂ is a carboxylated C-terminus. In yet another aspect, a peptide is provided having a sequence of CVGRDSKCGP PPCCMGMTCN YERVRKCT̂ (SEQ ID 25), where ̂ is a carboxylated C-terminus.
[0040] Table 2 shows a selectivity profile for various active peptide analogs against subtypes of hNa V 1s given as IC 50 data. The data in this Table show that all three peptides are potent inhibitors of hNa v 1.7. They also showed similarity in hNa v 1.7 potency between C. geo 1[desGSH] (SEQ ID 010) and C. geo 1[cystamine] (SEQ ID 011), which indicated that the second analog could be used as a substitute for the less stable C. geo 1[desGSH] (SEQ ID 003). These data reveal that analogs did not block TTX-resistant hNa V 1.5.
[0000]
TABLE 2
C.geo1[1-35]
C.geo1[desGSH]
C.geo1 [cystamine]
hNa v
SEQ ID 003
SEQ ID 010
SEQ ID 011
1.1
760
28
89
1.2
1110
52
51
1.3
>10000
126
336
1.4
1091
14
14
1.5
>10000
>10000
>10000
1.6
757
21
89
1.7
1396
71
72
[0041] It is noted that many amino acids in a given peptide can be variable, and such variations are considered within the present scope. For example, Pro residues may be substituted with hydroxy-Pro; hydroxy-Pro residues may be substituted with Pro residues; Arg residues may be substituted by Lys, ornithine, homoargine, nor-Lys, N-methyl-Lys, N,N-dimethyl-Lys, N,N,N-trimethyl-Lys or any synthetic basic amino acid; Lys residues may be substituted by Arg, ornithine, homoargine, nor-Lys, or any synthetic basic amino acid; Tyr residues may be substituted with any synthetic hydroxy containing amino acid; Ser residues may be substituted with Thr or any synthetic hydroxylated amino acid; Thr residues may be substituted with Ser or any synthetic hydroxylated amino acid; Phe and Trp residues may be substituted with any synthetic aromatic amino acid; and Asn, Ser, Thr or Hyp residues may be glycosylated. Tyr residues may also be substituted with the 3-hydroxyl or 2-hydroxyl isomers (meta-Tyr or ortho-Tyr, respectively) and corresponding O-sulpho- and O-phospho-derivatives or may be substituted with nor-Tyr, nitro-Tyr, mono-iodo-Tyr or di-iodo-Tyr. Aliphatic amino acids may be substituted by synthetic derivatives bearing non-natural aliphatic branched or linear side chains C n H 2n+2 up to and including n=8. Leu residues may be substituted with Leu(D). Trp residues may be substituted with halo-Trp, Trp(D) or halo-Trp(D). The halogen is iodo, chloro, fluoro or bromo; preferably iodo for halogen substituted-Tyr and bromo for halogen-substituted Trp. In addition, the halogen can be radiolabeled, e.g., 125 I-Tyr.
[0042] Examples of synthetic aromatic amino acids include, but are not limited to, nitro-Phe, 4-substituted-Phe wherein the substituent is C 1 -C 3 alkyl, carboxyl, hyrdroxymethyl, sulphomethyl, halo, phenyl, —CHO, —CN, —SO 3 H and —NHAc. Examples of synthetic hydroxy containing amino acids, include, but are not limited to, 4-hydroxymethyl-Phe, 4-hydroxyphenyl-Gly, 2,6-dimethyl-Tyr and 5-amino-Tyr. Examples of synthetic basic amino acids include, but are not limited to, N-1-(2-pyrazolinyl)-Arg, 2-(4-piperinyl)-Gly, 2-(4-piperinyl)-Ala, 2-[3-(2S)pyrrolininyl)-Gly and 2-[3-(2S)pyrrolininyl)-Ala. These and other synthetic basic amino acids, synthetic hydroxy containing amino acids or synthetic aromatic amino acids are described in Building Block Index, Version 3.0 (1999 Catalog, pages 4-47 for hydroxy containing amino acids and aromatic amino acids and pages 66-87 for basic amino acids; see also the website “amino-acids dot com”), incorporated herein by reference, by and available from RSP Amino Acid Analogues, Inc., Worcester, Mass.
[0043] In other aspects, Asn residues may be modified to contain an N-glycan and the Ser, Thr and Hyp residues may be modified to contain an O-glycan (e.g., g-N, g-S, g-T and g-Hyp). A glycan can refer to any N-, S- or O-linked mono-, di-, tri-, poly- or oligosaccharide that can be attached to any hydroxy, amino or thiol group of natural or modified amino acids by synthetic or enzymatic methodologies known in the art. The monosaccharides making up the glycan can include D-allose, D-altrose, D-glucose, D-mannose, D-gulose, D-idose, D-galactose, D-talose, D-galactosamine, D-glucosamine, D-N-acetyl-glucosamine (GlcNAc), D-N-acetyl-galactosamine (GalNAc), D-fucose or D-arabinose. These saccharides may be structurally modified, e.g., with one or more O-sulfate, O-phosphate, O-acetyl or acidic groups, such as sialic acid, including combinations thereof. The glycan may also include similar polyhydroxy groups, such as D-penicillamine 2,5 and halogenated derivatives thereof or polypropylene glycol derivatives. The glycosidic linkage is β and 1-4 or 1-3, preferably 1-3. The linkage between the glycan and the amino acid may be α or β, preferably α and is 1-.
[0044] Mucin type O-linked oligosaccharides are attached to Ser or Thr (or other hydroxylated residues of the present peptides) by a GalNAc residue. The monosaccharide building blocks and the linkage attached to this first GalNAc residue define the “core glycans,” of which eight have been identified. The type of glycosidic linkage (orientation and connectivities) are defined for each core glycan. Suitable glycans and glycan analogs are described further in U.S. Pat. No. 6,369,193 and in International Publication No. WO 00/23092, each incorporated herein by reference. In one aspect, a glycan can be Gal(β1→3)GalNAc(α1→).
[0045] The present peptides can be pharmacologically beneficial because they exhibit activity in animals, for example, in Nav1.7 channel blocking or inhibition. As such, compounds incorporating such peptides can be of use in the treatment of disorders for which a blocker or inhibitor for sodium channels (e.g. Nav1.7) is indicated.
[0046] In one aspect, pharmaceutical compositions are contemplated including a peptide having at least 95% sequence identity to SEQ ID 001, including pharmaceutically acceptable salts or solvates thereof, in a pharmaceutically acceptable carrier. In another aspect, the peptide can have a sequence of SEQ ID 001. In yet another aspect, X 23 can be aspartic acid, C 24 can be an un-substituted cysteine, and X 25 can be tyrosine. In a further aspect, X 30 can be SEQ ID 002. Additionally, in another aspect, X 23 can be aspartic acid, C 24 can be substituted with cystamine, and X 25 can be tyrosine. In a further aspect, X 30 can be SEQ ID 002.
[0047] Pharmaceutical compositions containing a compound, such as a peptide as an active ingredient can be prepared according to conventional pharmaceutical compounding techniques. See, for example, Remington: The Science and Practice of Pharmacy, 21st Ed., Lippincott Williams & Wilkins, Philadelphia, 2005. Typically, an therapeutically effective amount of active ingredient can be admixed with a pharmaceutically acceptable carrier. The carrier can take a wide variety of forms depending on the form of preparation desired for administration, e.g., intravenous, oral, parenteral or intrathecally. For examples of delivery methods see U.S. Pat. No. 5,844,077, incorporated herein by reference.
[0048] For oral administration, compound can be formulated into solid or liquid preparations such as capsules, pills, tablets, lozenges, melts, powders, suspensions or emulsions. In preparing the compositions in oral dosage form, any of the usual pharmaceutical media may be employed, such as, for example, water, glycols, oils, alcohols, flavoring agents, preservatives, coloring agents, suspending agents, and the like in the case of oral liquid preparations (such as, for example, suspensions, elixirs and solutions); or carriers such as starches, sugars, diluents, granulating agents, lubricants, binders, disintegrating agents and the like in the case of oral solid preparations (such as, for example, powders, capsules and tablets). Because of their ease in administration, tablets and capsules represent the most advantageous oral dosage unit form, in which case solid pharmaceutical carriers are obviously employed. If desired, tablets may be sugar-coated or enteric-coated by standard techniques. The active agent can be encapsulated to make it stable to passage through the gastrointestinal tract while at the same time allowing for passage across the blood brain barrier.
[0049] For parenteral administration, compounds can be dissolved in a pharmaceutical carrier and administered as either a solution or a suspension. Illustrative of suitable carriers are water, saline, dextrose solutions, fructose solutions, ethanol, or oils of animal, vegetative or synthetic origin. The carrier may also contain other ingredients, for example, preservatives, suspending agents, solubilizing agents, buffers and the like. When the compounds are being administered intrathecally, they may also be dissolved in cerebrospinal fluid.
[0050] A variety of administration routes are available. The particular mode selected will depend of course, upon the particular drug selected, the severity of the condition being treated and the dosage required for therapeutic efficacy. The methods of this disclosure, generally speaking, can be practiced using any mode of administration that is medically acceptable, meaning any mode that produces effective levels of the active compounds without causing clinically unacceptable adverse effects. Such modes of administration include oral, rectal, sublingual, topical, nasal, transdermal or parenteral routes. The term “parenteral” includes subcutaneous, intravenous, epidural, irrigation, intramuscular, release pumps, or infusion. For example, administration of the active agent according to this invention may be achieved using any suitable delivery means, including those described in U.S. Pat. No. 5,844,077, incorporated herein by reference.
[0051] Alternatively, targeting therapies can be used to deliver the peptide composition more specifically to certain types of cell, by the use of targeting systems such as antibodies or cell specific ligands. Targeting may be desirable for a variety of reasons, e.g. if the agent is unacceptably toxic, or if it would otherwise require too high a dosage, or if it would not otherwise be able to enter the target cells.
[0052] The active agents, which are peptides, can also be administered in a cell based delivery system in which a DNA sequence encoding an active agent is introduced into cells designed for implantation in the body of the patient, especially in the spinal cord region. Suitable delivery systems are described in U.S. Pat. No. 5,550,050 and published PCT Application Nos. WO 92/19195, WO 94/25503, WO 95/01203, WO 95/05452, WO 96/02286, WO 96/02646, WO 96/40871, WO 96/40959 and WO 97/12635. Suitable DNA sequences can be prepared synthetically for each active agent on the basis of the developed sequences and the known genetic code.
[0053] In some aspects, an active agent can be administered in a therapeutically effective amount. A “therapeutically effective amount” or simply “effective amount” of an active compound refers to a sufficient amount of the compound to treat the desired condition at a reasonable benefit/risk ratio applicable to any medical treatment. The actual amount administered, and the rate and time-course of administration, may depend on the nature and severity of the condition being treated. Prescription of treatment, e.g. decisions on dosage, timing, etc., is within the responsibility of general practitioners or specialists, and typically takes account of the disorder to be treated, the condition of the individual patient, the site of delivery, the method of administration and other factors known to practitioners. Examples of techniques and protocols can be found in Remington: The Science and Practice of Pharmacy.
[0054] Dosage can be adjusted appropriately to achieve desired drug levels, locally or systemically. Typically the active agents of the present disclosure exhibit their effect at a dosage range from about 0.001 mg/kg to about 250 mg/kg, preferably from about 0.01 mg/kg to about 100 mg/kg of the active ingredient, more preferably from about 0.05 mg/kg to about 75 mg/kg. A suitable dose can be administered in multiple sub-doses per day. Typically, a dose or sub-dose may contain from about 0.1 mg to about 500 mg of the active ingredient per unit dosage form. Another dosage can contain from about 0.5 mg to about 100 mg of active ingredient per unit dosage form. Dosages are generally initiated at lower levels and increased until desired effects are achieved. In the event that the response in a subject is insufficient at such doses, even higher doses (or effective higher doses by a different, more localized delivery route) may be employed to the extent that patient tolerance permits. Continuous dosing over, for example, 24 hours or multiple doses per day are contemplated to achieve appropriate systemic levels of compounds.
[0055] Advantageously, the compositions are formulated as dosage units, each unit being adapted to supply a fixed dose of active ingredients. Tablets, coated tablets, capsules, ampoules and suppositories are examples of dosage forms according to the invention.
[0056] It is noted that exact individual dosages, as well as daily dosages, can be determined according to standard medical principles under the direction of a physician or veterinarian for use humans or animals.
[0057] The pharmaceutical compositions will generally contain from about 0.0001 to 99 wt. %, or about 0.001 to 50 wt. %, or about 0.01 to 10 wt. % of the active ingredient by weight of the total composition. In addition to the active peptide, the pharmaceutical compositions and medicaments can also contain other pharmaceutically active compounds. Examples of other pharmaceutically active compounds include, but are not limited to, analgesic agents, cytokines and therapeutic agents in all of the major areas of clinical medicine. When used with other pharmaceutically active compounds, the peptides of the present invention may be delivered in the form of drug cocktails. A cocktail is a mixture of any one of the compounds useful with this invention with another drug or agent. In this embodiment, a common administration vehicle (e.g., pill, tablet, implant, pump, injectable solution, etc.) would contain both the instant composition in combination with a supplementary potentiating agent. The individual drugs of the cocktail are each administered in therapeutically effective amounts. A therapeutically effective amount will be determined by the parameters described above; but, in any event, is that amount which establishes a level of the drugs in the area of body where the drugs are required for a period of time which is effective in attaining the desired effects.
[0058] A Nav1.7 blocker or inhibitor can thus be usefully combined with another pharmacologically active compound, or with two or more other pharmacologically active compounds, particularly in the treatment of pain. Such combinations offer the possibility of significant advantages, including patient compliance, ease of dosing and synergistic activity. In such combinations, a conopeptide described herein can be administered simultaneously, sequentially or separately in combination with the other therapeutic agent or agents. Agents which may be administered with a conopeptide described herein include agents described in US 2012/0010207, which is incorporated herein by reference.
[0059] The term “pharmaceutical composition” refers to physically discrete coherent portions suitable for medical administration. “Pharmaceutical composition in dosage unit form” refers to physically discrete coherent units suitable for medical administration, each containing a daily dose or a multiple (up to four times) or a sub-multiple (down to a fortieth) of a daily dose of the active compound in association with a carrier and/or enclosed within an envelope. Whether the composition contains a daily dose, or for example, a half, a third or a quarter of a daily dose, will depend on whether the pharmaceutical composition is to be administered once or, for example, twice, three times or four times a day, respectively.
[0060] The term “salt”, as used herein, denotes acidic and/or basic salts, formed with inorganic or organic acids and/or bases, preferably basic salts. While pharmaceutically acceptable salts are preferred, particularly when employing the compounds of the invention as medicaments, other salts find utility, for example, in processing these compounds, or where non-medicament-type uses are contemplated. Salts of these compounds may be prepared by art-recognized techniques.
[0061] Examples of such pharmaceutically acceptable salts include, but are not limited to, inorganic and organic addition salts, such as hydrochloride, sulphates, nitrates or phosphates and acetates, trifluoroacetates, propionates, succinates, benzoates, citrates, tartrates, fumarates, maleates, methane-sulfonates, isothionates, theophylline acetates, salicylates, respectively, or the like. Lower alkyl quaternary ammonium salts and the like are suitable, as well.
[0062] As used herein, the term “pharmaceutically acceptable” carrier means a non-toxic, inert solid, semi-solid liquid filler, diluent, encapsulating material, formulation auxiliary of any type, or simply a sterile aqueous medium, such as saline. Some examples of the materials that can serve as pharmaceutically acceptable carriers are sugars, such as lactose, glucose and sucrose, starches such as corn starch and potato starch, cellulose and its derivatives such as sodium carboxymethyl cellulose, ethyl cellulose and cellulose acetate; powdered tragacanth; malt, gelatin, talc; excipients such as cocoa butter and suppository waxes; oils such as peanut oil, cottonseed oil, safflower oil, sesame oil, olive oil, corn oil and soybean oil; glycols, such as propylene glycol, polyols such as glycerin, sorbitol, mannitol and polyethylene glycol; esters such as ethyl oleate and ethyl laurate, agar; buffering agents such as magnesium hydroxide and aluminum hydroxide; alginic acid; pyrogen-free water; isotonic saline, Ringer's solution; ethyl alcohol and phosphate buffer solutions, as well as other non-toxic compatible substances used in pharmaceutical formulations.
[0063] Wetting agents, emulsifiers and lubricants such as sodium lauryl sulfate and magnesium stearate, as well as coloring agents, releasing agents, coating agents, sweetening, flavoring and perfuming agents, preservatives and antioxidants can also be present in the composition, according to the judgment of the formulator. Examples of pharmaceutically acceptable antioxidants include, but are not limited to, water soluble antioxidants such as ascorbic acid, cysteine hydrochloride, sodium bisulfite, sodium metabisulfite, sodium sulfite, and the like; oil soluble antioxidants, such as ascorbyl palmitate, butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), lecithin, propyl gallate, alpha tocopherol and the like; and the metal chelating agents such as citric acid, ethylenediamine tetraacetic acid (EDTA), sorbitol, tartaric acid, phosphoric acid and the like.
[0064] Sodium channels such as Nav1.7 may play a role in various pain states, including acute, inflammatory and/or neuropathic pain. Deletion of the SCN9A gene in nociceptive neurons of mice led to a reduction in mechanical and thermal pain thresholds and reduction or abolition of inflammatory pain responses. In humans, Nav1.7 protein has been shown to accumulate in neuromas, particularly painful neuromas. Gain of function mutations of Nav1.7, both familial and sporadic, have been linked to primary erythermalgia, a disease characterized by burning pain and inflammation of the extremities, and paroxysmal extreme pain disorder. Further, non-selective sodium channel blockers lidocaine and mexiletine can provide symptomatic relief in cases of familial erythermalgia and carbamazepine is effective in reducing the number and severity of attacks in PEPD. Further evidence of the role of Nav1.7 in pain is found in the phenotype of loss of function mutations of the SCN9A gene.
[0065] As such, in another aspect of the present disclosure, a method of treating a condition or treating effects of a condition in a subject where sodium channels exhibit increased activity is provided. Such a method can include administering to the subject a therapeutically effective amount of a composition as has been described herein to modulate the activity of the sodium channels. Non-limiting examples of such conditions can include, acute pain, chronic pain, neuropathic pain, cancer pain, diabetic neuropathy, inflammatory pain, trigeminal pain, perioperative pain, visceral pain, nociceptive pain including post-surgical pain, and mixed pain types involving the viscera, gastrointestinal tract, cranial structures, musculoskeletal system, spine, urogenital system, cardiovascular system and CNS, including cancer pain, back and orofacial pain, or a combination thereof. It is also contemplated that such a condition can be a neurological condition, including spinal cord injury, traumatic brain injury, peripheral nerve injury, and the like.
[0066] Peptides of the invention can be tested for their effect in reducing or alleviating pain using animal models, such as the SNL (spinal nerve ligation) rat model of neuropathic pain, carageenan induced hyperalgesia model, the Freund's complete adjuvant (CFA)-induced hyperalgesia model, the thermal injury model, the formalin model and the Bennett Model and other modes as described in U.S. Pat. Appl. No. 2011/0124711A1 and U.S. Pat. No. 7,998,980. Carageenan induced hyperalgesia and (CFA)-induced hyperalgesia are models of inflammatory pain. The Bennett model provides an animal model for chronic pain.
[0067] Any of the foregoing animal models may be used to evaluate the efficacy of peptides of the invention in treating pain. The efficacy can be compared to a no treatment or placebo control. Additionally or alternatively, efficacy can be evaluated in comparison to one or more known pain relieving medicaments.
[0068] Generally, physiological pain is an important protective mechanism designed to warn a subject of danger from potentially injurious stimuli. The pain system operates through a specific set of primary sensory neurons, and in some cases is activated by noxious stimuli via peripheral transducing mechanisms. These sensory fibers are known in the art as nociceptors, and they are characteristically small diameter axons with slow conduction velocities. Nociceptors can encode the intensity, duration, and quality of noxious stimuli; topographical organization of nociceptor projections to the spinal cord also allows stimuli location to be encoded.
[0069] Nociceptors are found on nociceptive nerve fibers of which there are two main types, A-delta fibers (myelinated) and C fibers (non-myelinated). The activity generated by nociceptor input is transferred, after complex processing in the dorsal horn, either directly, or via brain stem relay nuclei, to the ventrobasal thalamus and then on to the cortex, where the sensation of pain is generated.
[0070] Pain may generally be classified as acute or chronic. Acute pain begins suddenly and is short-lived (usually twelve weeks or less). It is usually associated with a specific cause such as a specific injury and is often sharp and severe. It is the kind of pain that can occur after specific injuries resulting from surgery, dental work, a strain or a sprain. Acute pain does not generally result in any persistent psychological response. In contrast, chronic pain is long-term pain, typically persisting for more than three months and leading to significant psychological and emotional problems. Common examples of chronic pain are neuropathic pain (e.g. painful diabetic neuropathy, postherpetic neuralgia), carpal tunnel syndrome, back pain, headache, cancer pain, arthritic pain and chronic post-surgical pain.
[0071] When a substantial injury occurs to body tissue, via disease or trauma, the characteristics of nociceptor activation are altered and there is sensitization in the periphery, locally around the injury and centrally where the nociceptors terminate. These effects lead to a heightened sensation of pain. In acute pain these mechanisms can be useful, in promoting protective behaviors which may better enable repair processes to take place. The normal expectation would be that sensitivity returns to normal once the injury has healed. However, in many chronic pain states, the hypersensitivity far outlasts the healing process and is often due to nervous system injury. This injury often leads to abnormalities in sensory nerve fibers associated with maladaptation and aberrant activity.
[0072] Clinical pain is present when discomfort and abnormal sensitivity feature among the patient's symptoms. Patients tend to be quite heterogeneous and may present with various pain symptoms. Such symptoms include: 1) spontaneous pain which may be dull, burning, or stabbing; 2) exaggerated pain responses to noxious stimuli (hyperalgesia); and 3) pain produced by normally innocuous stimuli (allodynia). Although patients suffering from various forms of acute and chronic pain may have similar symptoms, the underlying mechanisms may be different and may, therefore, require different treatment strategies. Pain can also therefore be divided into a number of different subtypes according to differing pathophysiology, including nociceptive, inflammatory and neuropathic pain.
[0073] Nociceptive pain is induced by tissue injury or by intense stimuli with the potential to cause injury. Pain afferents are activated by transduction of stimuli by nociceptors at the site of injury and activate neurons in the spinal cord at the level of their termination. This is then relayed up the spinal tracts to the brain where pain is perceived (Meyer et al., 1994). The activation of nociceptors activates two types of afferent nerve fibers. Myelinated A-delta fibers transmit rapidly and are responsible for sharp and stabbing pain sensations, whilst unmyelinated C fibers transmit at a slower rate and convey a dull or aching pain. Moderate to severe acute nociceptive pain is a prominent feature of pain from central nervous system trauma, strains/sprains, burns, myocardial infarction and acute pancreatitis, post-operative pain (pain following any type of surgical procedure), posttraumatic pain, renal colic, cancer pain and back pain. Cancer pain may be chronic pain such as tumor related pain (e.g. bone pain, headache, facial pain or visceral pain) or pain associated with cancer therapy (e.g. post-chemotherapy syndrome, chronic postsurgical pain syndrome or post radiation syndrome). Cancer pain may also occur in response to chemotherapy, immunotherapy, hormonal therapy or radiotherapy. Back pain may be due to herniated or ruptured intervertebral discs or abnormalities of the lumber facet joints, sacroiliac joints, paraspinal muscles or the posterior longitudinal ligament. Back pain may resolve naturally but in some patients, where it lasts over 12 weeks, it becomes a chronic condition which can be particularly debilitating.
[0074] Neuropathic pain is currently defined as pain initiated or caused by a primary lesion or dysfunction in the nervous system. Nerve damage can be caused by trauma and disease and thus the term ‘neuropathic pain’ encompasses many disorders with diverse aetiologies. These include, but are not limited to, peripheral neuropathy, diabetic neuropathy, post herpetic neuralgia, trigeminal neuralgia, back pain, cancer neuropathy, HIV neuropathy, phantom limb pain, carpal tunnel syndrome, central post-stroke pain and pain associated with chronic alcoholism, hypothyroidism, uremia, multiple sclerosis, spinal cord injury, Parkinson's disease, epilepsy and vitamin deficiency. Neuropathic pain is pathological as it has no protective role. It is often present well after the original cause has dissipated, commonly lasting for years, significantly decreasing a patient's quality of life. The symptoms of neuropathic pain are difficult to treat, as they are often heterogeneous even between patients with the same disease. They include spontaneous pain, which can be continuous, and paroxysmal or abnormal evoked pain, such as hyperalgesia (increased sensitivity to a noxious stimulus) and allodynia (sensitivity to a normally innocuous stimulus).
[0075] The inflammatory process is a complex series of biochemical and cellular events, activated in response to tissue injury or the presence of foreign substances, which results in swelling and pain. Arthritic pain is the most common inflammatory pain. Rheumatoid disease is one of the commonest chronic inflammatory conditions in developed countries and rheumatoid arthritis is a common cause of disability. The exact aetiology of rheumatoid arthritis is unknown, but current hypotheses suggest that both genetic and microbiological factors may be important. It has been estimated that almost 16 million Americans have symptomatic osteoarthritis (OA) or degenerative joint disease, most of who are over 60 years of age, and this is expected to increase to 40 million as the age of the population increases, making this a public health problem of enormous magnitude. Most patients with osteoarthritis seek medical attention because of the associated pain. Arthritis has a significant impact on psychosocial and physical function and is known to be the leading cause of disability in later life. Ankylosing spondylitis is also a rheumatic disease that causes arthritis of the spine and sacroiliac joints. It varies from intermittent episodes of back pain that occur throughout life to a severe chronic disease that attacks the spine, peripheral joints and other body organs.
[0076] Another type of inflammatory pain is visceral pain which includes pain associated with inflammatory bowel disease (IBD). Visceral pain is pain associated with the viscera, which encompass the organs of the abdominal cavity. These organs include the sex organs, spleen and part of the digestive system. Pain associated with the viscera can be divided into digestive visceral pain and non-digestive visceral pain. Commonly encountered gastrointestinal (GI) disorders that cause pain includes functional bowel disorder (FBD) and inflammatory bowel disease (IBD). These GI disorders include a wide range of disease states that are currently only moderately controlled, including, in respect of FBD, gastro-esophageal reflux, dyspepsia, irritable bowel syndrome (IBS) and functional abdominal pain syndrome (FAPS), and, in respect of IBD, Crohn's disease, ileitis and ulcerative colitis, all of which regularly produce visceral pain. Other types of visceral pain include the pain associated with dysmenorrhea, cystitis and pancreatitis and pelvic pain.
[0077] It should be noted that some types of pain have multiple aetiologies and thus can be classified in more than one area, e.g. back pain and cancer pain have both nociceptive and neuropathic components. Other types of pain include: (a) pain resulting from musculo-skeletal disorders, including myalgia, fibromyalgia, spondylitis, sero-negative (non-rheumatoid) arthropathies, non-articular rheumatism, dystrophinopathy, glycogenolysis, polymyositis and pyomyositis; (b) heart and vascular pain, including pain caused by angina, myocardical infarction, mitral stenosis, pericarditis, Raynaud's phenomenon, scleredoma and skeletal muscle ischemia; (c) head pain, such as migraine (including migraine with aura and migraine without aura), cluster headache, tension-type headache mixed headache and headache associated with vascular disorders; (d) erythermalgia; and (e) orofacial pain, including dental pain, otic pain, burning mouth syndrome and temporomandibular myofascial pain.
EXAMPLES
Example 1
Venom Screening
[0078] Material from 10 Conus species has been extracted, fractionated, and screened for block of hNaV1.7 using the QPatch assay. A summary of Conus species and fractionation data is provided in Table 1. Based on initial efforts, a total of 393 fractions have been collected and screened for activity. Of these initial crude fractions, 29 fractions were identified as ‘hits’, exhibiting ≧30% block of hNaV1.7 (˜9.2% of fractions were found to be active) (Table 3).
[0000]
TABLE 3
Overview of Screening Venom Libraries
Fractionation Number of ‘hits’
Species
(block ≧ 30%)
C. miles
2
C. vexillum
2
C. geographus
11
C. betulinus
0
C. textile
2
C. striatus
9
C. magus
0
C. marmoreus
1
C. distans
1
C. quercinas
1
Example 2
Screening of Conpeptide Fractions
[0079] From screening and deconvolution of venom fractions, we identified Conus geographus as one promising species in possessing conopeptide components that block hNaV1.7. Initial screening results of C. geographus venom are summarized in Table 4.
[0000]
TABLE 4
Initial QPatch Results From the Crude Fractionation of C. geographus .
Fraction
1
2
3
4
5
6
7
8
9
10
% Inh.
24 a
32
21
42
27
37
28
41
a
23
59
a
Fraction
11
12
13
14
15
16
17
18
19
20
% Inh.
11
31
15
6
22
8
21
2
10 a
15
Fraction
21
22
23
24
25
26
27
28
29
30
% Inh.
18
26
5
5
9
5
9
15
10
10
Fraction
31
32
33
34
34
36
37
38
39
40
% Inh.
−14
20
42
27
6
3
−1
7
18
13
Fraction
41
42
43
44
45
46
47
48
49
50
% Inh.
3
2
20
8
37
40
28
24 b
33
a
41
a
Fraction
51
52
53
54
55
% Inh.
17 a
22
−1
5
−7
Conopeptide material extracted from approximately 600 mg lyophilized C. geographus ducts and was screened against hNaV1.7. Fraction amounts corresponding to approximately 6 mg equivalents of total conopeptide material were re-suspended in 200 μL volume.
a denotes shorter exposure due to seal breakdown.
b n = 2
Fractions exhibiting ≧30% block of hNaV1.7 are indicated in bold
Example 3
Deconvolution and Identification of Hits
[0080] Initial screening of C. geographus crude fractions revealed two major groupings of fractions that blocked the hNaV1.7 response (See Table 4). Further purification of these fractions resulted in sub-fractions that exhibited hNaV1.7 block greater than 30%: SubFr 34.4 (69%), SubFr 34.5 (69% block), SubFr 33.5 (34% block), SubFr 33.6 (40% block), SubFr 33.7 (31% block) (Table 5).
[0000]
TABLE 5
QPatch Results From Sub-fractionation of C. geographus Fractions
Fraction
32
32.2
32.3
32.4
32.5
32.6
32.7
% Inh.
20
15
18
18
25
26
29
Fraction
33
33.3
33.4
33.5
33.6
33.7
33.8
% Inh.
42
31
23
34
40
31
20
Fraction
34
34.3
34.4
34.5
34.6
Inh.
27
33
69
69
18
Fraction
45
45.4
45.5
45.6
45.7
% Inh.
37
22 a
13
30
8
Fraction
46
46.3
46.4
% Inh.
40
11
22
Fraction
47
47.4
47.5
% Inh.
28
23
23
Fractions exhibiting ≧30% block of hNaV1.7 are indicated in bold
Example 4
Characterization of the Nav1.7 Active Peptides from C. Geographus
[0081] Initial sequencing efforts of the C. geographus active peptide identified in SubFr 33.6 revealed an incomplete peptide sequence (GXCCGDOGATC KLRLYCCSGF CDCYTcTc . . . ) where X denotes ambiguity in the amino acid sequence SEQ ID 026. To elucidate the complete sequence of this peptide, both mass spectrometry methods and molecular biology techniques were employed in parallel.
[0082] Molecular Biology Methods. Due to limited quantities of the native active peptide, RACE-PCR experiments were conducted in an attempt to elucidate the entire peptide sequence. From PCR experiments, the entire sequence was identified
[0000] SEQ ID 027 (GWCGDPGATC GKLRLYCCSG FCDCYTKTCK DKSSA).
Furthermore, transcriptome information confirmed this sequence in multiple locations using RNA isolated from C. geographus ducts.
[0083] Mass Spectrometry Analysis. The calculated mass (3739.2 Da), based upon the sequence obtained from PCR experiments, and the experimentally-determined mass (3934.4 Da) differed by 195.3 Da suggesting the presence of modified residues within the sequence.
[0084] Solid Phase Peptide Synthesis. Based on the unmodified sequence obtained from the PCR and transcriptome data, analogs of the C. geographus peptide were designed and synthesized by SPPS using standard Fmoc-protocols. Initial syntheses lacked Ser-34 (below). Synthesis of the active peptide was repeated successfully resulting in analogs C. geo 1[1-35] (SEQ ID 003) and C. geo 1[C24Abu] (SEQ ID 004).
[0000]
C. geo1[des-Ser34]:
SEQ ID 028
GWCGDOGATCGKLRLYCCSGFCDCYTKTCKDKS_A{circumflex over ( )}
C. geo1[C24Abu,des-Ser34]:
SEQ ID 029
GWCGDOGATCGKLRLYCCSGFCD(Abu)YTKTCKDKS_A{circumflex over ( )}
C. geo1[1-35]:
SEQ ID 003
GWCGDOGATCGKLRLYCCSGFCDCYTKTCKDKSSA{circumflex over ( )}
C. geo1[C24Abu]:
SEQ ID 004
GWCGDOGATCGKLRLYCCSGFCD(Abu)YTKTCKDKSSA{circumflex over ( )}
*Note:
Abu = Fmoc-aminobutyric acid;
{circumflex over ( )}denotes carboxylated C-terminus
[0085] Synthetic peptides were folded using both air oxidation and glutathione-assisted oxidation methods. Folding mixtures were purified by semi-preparative RP-HPLC and the molecular masses of the folding products were confirmed by MALDI-TOF mass spec.
[0086] Electrophysiology. Folded peptide analogs were first tested for activity at the University of Utah against NaV1.7 from rat. C. geo 1[des-Ser34] (SEQ ID 028) exhibited very slow reversibility and resulted in 70% block using 3.3 μM peptide. Isosteric replacement of Cys24 with aminobutyric acid (Abu) in C. geo 1[C24Abu,des-Ser34] (SEQ ID 004) decreased NaV1.7 block to 20% at 10 μM and was quickly reversible (data not shown). These data suggest that Cys24 is integral for efficient block of NaV1.7. As such, 10 nmols of C. geo 1[des-Ser34] (SEQ ID 028) was subsequently used for testing against human NaV1.7 in the QPatch assay ( FIG. 1 ).
[0087] RACE-PCR: RACE-PCR was employed to capture the entire sequence (unmodified; SEQ ID 030):
[0000] GGTQHRALRS TIKLSLLRQH RGWCGDPGAT CGKLRLYCCS GFCDCYTKTC KDKSSASSPS VLYPFLPES.
Δmass between unmodified sequence and MALDI-ToF data was +197.1 Da suggesting modification of the sequence.
[0088] MALDI-ToF analysis: MALDI-ToF analysis of C. geo[ 1-35, des-Ser34] (SEQ ID 028) and C. geo 1[1-35] (SEQ ID 003) showed the peptide to be ‘heavy’ by 305 Da indicating peptide-GSH adduct formed at Cys-24. Peptide-adducts may suggest bulky modification of Cys-24, e.g. S-linked glycosylation.
Example 5
Verification of which Cys (Cys22 or Cys24) is the Free Cys Residue in Synthetic, Folded C. Geo 1
[0089] The free cysteine of folded C. geo 1[desGSH] (SEQ ID 010) was alkylated with 4-vinylpyridine (VP) and then the peptide was reduced and all remaining cysteines were alkylated with iodoacetamide (IAM-iodoacetamide). Peptide treated this way was then digested with Endoproteinase AspN, subjected to analytical reversed phase (RP) HPLC, and all products were collected and analyzed by MALDI-TOF. The mass of peak 1 (17.16 min, analytical HPLC; [M+H]+=1123.56) was found to be the same as expected mass ([M+H]+=1123.93) for a peptide fragment DC(VP)YTKTC(IAM)K (SEQ ID 031) of digested C. geo 1. The results show that the Cys24 is the one with a free thiol and likely (disulfide) linked to GSH in synthetic C. geo 1.
Example 6
Connectivity of Cys Residues in Synthetic C. Geo 1
[0090] For this example C. geo 1[desGSH] (SEQ ID 010) was used. The peptide was treated with 4-vinylpyridine and purified by HPLC. Next, it was treated with tris(2-carboxyethyl)phosphine (TCEP) for 45 min, which caused partial reduction of the peptide. Finally, the mixture was treated with N-ethylmaleimide (NEM), and purified by analytical RP-HPLC. Masses of collected peaks 1 through 5 were analyzed by MALDI-TOF. Following results were obtained:
a) Peak 1 [M+H] + found =3842.37, which corresponds to 3 disulfide closed and alkylated Cys 24 ; b) Peak 2 [M+H] + found =4093.56, 2 disulfide bridges closed, 1 disulfide alkylated with NEM; c) Peak 3 [M+H] + found =4345.69, 1 disulfide bridge closed, 2 disulfide alkylated with NEM; d) Peak 4 [M+H] + found =4345.66, 1 disulfide bridge closed, 2 disulfide alkylated with NEM; e) Peak 5 [M+H] + found =4598.60, 3 disulfide bonds alkylated with NEM.
Intermediates labeled as Peak 1, 2 and 3 were treated with TCEP for 1 h and then reacted with IAM. The resulting material was purified by RP-HPLC and then treated with modified trypsin for 3 h. This material was next analyzed by MALDI-TOF. Based on the overall data, it was determined that the connectivity in synthetic C. geo 1[desGSH] (SEQ ID 010) is: Cys3-Cys18, Cys10-Cys22 and Cys17-Cys29, which falls into a predicted VI/VII cysteine framework. It was also an additional confirmation that Cys24 was not involved in disulfide-bond formation but nevertheless involved in the functional activity of the synthetic C. geo 1.
Example 7
Discovery of C. Geo 2
[0096] In addition to the biologically-active C. geo 1 peptide isolated from Conus geographus, a second active peptide has been identified from sub-fraction 34.5 ( C. geo 2). QPatch assay of the isolated peptide resulted in 69% block of hNaV1.7. The isolated native peptide was reduced and alkylated by treatment with dithiothreitol and 4-vinylpyridine in preparation for sequencing by Edman degradation at the University of Utah. Sequencing efforts revealed the partial peptide sequence of XXCGDAGDA CGTLKLRCCS GLCNQYSGTC S . . . , (SEQ ID 032) where X denotes ambiguity in the amino acid sequence. Using the partial sequence, the complete peptide sequence was retrieved by searching C. geographus transcriptome data as described previously. The complete sequence of C. geo 2 exhibits the canonical ω-conopeptide cysteine framework and shares a fair amount of sequence identity with C. geo 1 (˜55% homologous); however, C. geo 2 lacks the additional cysteine (Cys-24) observed in C. geo 1 (See alignment below).
[0000]
C. geo1
(SEQ ID 003)
G WCGD O G AT CG K L R L Y CCSG F C D CY TK TC KDKSSA{circumflex over ( )}
C. geo2
(SEQ ID 024)
D WCGD A G DA CG T L K L R CCSG L C NQ Y SG TC TG{circumflex over ( )}
*Note:
Bold represents homology between sequences;
{circumflex over ( )}denotes carboxylated C-terminus
[0097] Of particular interest is that members of the ω-conopeptide family typically possess a C-terminal [Ser-Ser-Ala] tripeptide following the stop codon. However, C. geo 1 (SEQ ID 003) has incorporated the tripeptide into the mature sequence, thereby increasing the C-terminal diversity of this peptide family.
Example 8
Discovery of C. Geo 3
[0098] A mass of 3094.35 Da was identified in an active SubFr 33.6 of conus geographus (40% block of hNav1.7). A sequence of a peptide was identified (SEQ ID 025) in the transcriptome data for Conus geographus, characterized by the same mass. It was then synthesized and folded in the presence of reduced and oxidized gluthatione. Three peaks of the same, desired mass were collected and tested against hNav1.7 and rNav1.7. In both cases peptide was not active.
[0099] It is to be understood that the above-described compositions and modes of application are only illustrative of preferred embodiments of the present invention. Numerous modifications and alternative arrangements may be devised by those skilled in the art without departing from the spirit and scope of the present invention and the appended claims are intended to cover such modifications and arrangements. Thus, while the present invention has been described above with particularity and detail in connection with what is presently deemed to be the most practical and preferred embodiments of the invention, it will be apparent to those of ordinary skill in the art that numerous modifications, including, but not limited to, variations in size, materials, shape, form, function and manner of operation, assembly and use may be made without departing from the principles and concepts set forth herein.
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The present invention relates to conopeptides that are naturally available in minute amounts in the venom of the cone snails or analogous to the naturally available peptides, and which block the sodium channels.
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[0001] This application is a continuation in part of application 20050198728 published Sep. 15, 2005
FIELD OF THE INVENTION
[0002] The present invention relates to wading pools. More specifically, to a wading pool retrofittable onto a main pool.
BACKGROUND OF THE INVENTION
[0003] Wading or accessory pools for in-ground or above-ground main pools are known in the art. However, wading or accessory pools are usually integrally built with the main pool. Therefore, if there is an existing main pool, it is often very hard or impossible to add an accessory or wading pool to the main pool. Furthermore, when the wading pool is fitted to the main pool, it is often impossible to disassemble the wading pool for moving or maintenance thereof.
[0004] In addition, accessory pools for residential use are typically relatively deep and are mainly used as hot tubs or jacuzzis. While helping a user to relax, hot tubs do not allow tanning as the user is covered in water. Also, hot tubs require that young children in the hot tub be under constant adult supervision.
[0005] Against this background there exists a need in the industry to provide a novel wading pool.
Prior Art Capability and Motivations, as Helping to Show Patentability Here
[0006] Even in hindsight consideration of the present invention to determine its inventive and novel nature, it is not only conceded but emphasized that the prior art had many details usable in this invention, but only if the prior art had had the guidance of the present invention, details of both capability and motivation.
[0007] That is, it is emphasized that the prior art had/or knew several particulars which individually and accumulatively show the non-obviousness of this combination invention. E.g.,
[0008] a) Use of fiberglass in constructing spas, tub and related water containing vessels;
[0009] b) The nature of an invention as being a “novel combination”, in spite of existence of details separately, is especially significant here where the novelty is of the plurality of concepts, i.e., the use of a shallow wading pool with the use of wooden “kit” construction in conjunction with an existing pool and its water filtration system;
[0010] c) The addition of providing support members integrated into the wading pool structure into which the privacy wall sections can be mechanically fastened;
[0011] d) The matter of particular cost-factors, in a detailed form which would surely convey the realization of the huge costs involved in installing a “kit” versus digging, making forms and pouring concrete as is known for existing adjoining spas and similar structures;
[0012] e) The ease of tooling for the present invention has surely given manufacturers ample incentive to have made modifications for commercial competitiveness in a competitive industry, if the concepts had been obvious;
[0013] f) The prior art has always had sufficient skill to make many types of fiberglass shapes, more than ample skill to have achieved the present invention, but only if the concepts and their combinations had been conceived;
[0014] g) Substantially all of the operational characteristics and advantages of details of the present invention, when considered separately from one another and when considered separately from the present invention's details and accomplishment of the details, are within the skill of persons of various arts, but only when considered away from the integrated and novel combination of concepts which by their cooperative combination achieve this advantageous invention;
[0015] h) The details of the present invention, when considered solely from the standpoint of construction, are exceedingly simple, basically fiberglass construction and plastic or wooden walls, benches and framing and the matter of simplicity of construction has long been recognized as indicative of inventive creativity;
[0016] i) Similarly, and a long-recognized indication of inventiveness of a novel combination, is the realistic principle that a person of ordinary skill in the art, as illustrated with respect to the claimed combination as differing in the stated respects from the prior art both as to construction and concept, is presumed to be one who thinks along the line of conventional wisdom in the art and is not one who undertakes to innovate; and
[0017] j) The predictable benefits from a novel swimming pool product and installation method having the features of this invention would seem sufficiently high that others would have been working on this type of product, but only if the concepts which it presents had been conceived.
[0018] Accordingly, although the prior art has had capability and motivation, amply sufficient to presumably give incentive to the development a product and installation method according to the present invention, the fact remains that this invention awaited the creativity and inventive discovery of the present Inventor. In spite of ample motivation, the prior art did not suggest this invention.
Prior Art as Particular Instances of Failure to Provide This Novel Product and Installation Method
[0019] In view of the general economic advantages of the present invention as an improved embodiment of the prior art, it may be difficult to realize that the prior art has not conceived of the combination purpose and achievement of the present invention, even though the need for shallow pools is a known requested commodity for people nowadays who want to sunbathe while being in cool water or who just want to dip their feet in water while socializing with friends or parents and grandparents alike being able to watch over children playing in a safe shallow water environment. Also, the ease of assembly also translates in an ease to disasemble should the owner of the wading pool decide to move and carry his wading pool with him. The various combination provided in this invention would have been desired and attempted long ago, but only if its factors and combination-nature had been obvious.
[0020] Other considerations, as herein mentioned, when realistically evaluated show the inventive nature of the present invention, a change in concept which the prior patent and other prior art did not achieve.
Summary of the Prior Art's Lack of Suggestions of the Concepts of the Invention's Combination
[0021] And the existence of such prior art knowledge and related ideas embodying such various features is not only conceded, it is emphasized; for as to the novelty here of the combination, of the invention as considered as a whole, a contrast to the prior art helps also to remind of needed improvement, and the advantages and the inventive significance of the present concepts. Thus, as shown herein as a contrast to all the prior art, the inventive significance of the present concepts as a combination is emphasized, and the nature of the concepts and their results can perhaps be easier seen as an invention.
[0022] Although varieties of prior art are conceded, and ample motivation is shown, and full capability in the prior art is conceded, no prior art shows or suggests details of the overall combination of the present invention, as is the proper and accepted way of considering the inventiveness nature of the concepts.
[0023] That is, although the prior art may show an approach to the overall invention, it is determinatively significant that none of the prior art shows the novel and advantageous concepts in combination, which provides the merits of this invention, even though certain details are shown separately from this accomplishment as a combination.
[0024] And the prior art's lack of an invention of an economical, easy to install shallow pool achieving a practical, durable, esthetic look and other advantages of the present invention, which are goals only approached by the prior art, must be recognized as being a long-felt need now fulfilled.
[0025] Accordingly, the various concepts and components are conceded and emphasized to have been widely known in the prior art as to various installations; nevertheless, the prior art not having had the particular combination of concepts and details as here presented and shown in novel combination different from the prior art and its suggestions, even only a fair amount of realistic humility, to avoid consideration of this invention improperly by hindsight, requires the concepts and achievements here to be realistically viewed as a novel combination, inventive in nature. And especially is this a realistic consideration when viewed from the position of a person of ordinary skill in this art at the time of this invention, and without trying to reconstruct this invention from the prior art without use of hindsight toward particulars not suggested by the prior art.
SUMMARY OF THE INVENTION
[0026] In view of the foregoing disadvantages inherent in the known devices now present in the prior art, the present invention, which will be described subsequently in greater detail, is to provide objects and advantages which are:
[0027] To provide a wading pool retrofittable to a main pool.
[0028] To provide a wading pool that is very shallow to allow for tanning.
[0029] To provide a wading pool assemblable in kit form.
[0030] To provide a wading pool which can be quickly installed or uninstalled to a main pool.
[0031] To provide a wading pool which discharges its water as a waterfall into the main pool and as such, acts as an intermediary for the normal water circulation circuit of a pool.
[0032] To provide a wading pool that can be manufactured economically.
[0033] To attain these ends, the present invention generally comprises a wading pool retrofittable to a main pool, the wading pool being for containing water. The wading pool includes a plumbing system for providing the water and a water basin for receiving the water provided by the plumbing system. The plumbing system is an extension of the existing plumbing system of an existing pool in that it reroutes the usual water feed so that it passes first into the wading pool and from the wading pool, excess water will fall into the existing pool. The water basin is defined by first and second side walls, a back wall and a front wall. The first and second side walls, the back wall and the front wall each have a respective height. The height of the front wall is substantially lower than the height of the back wall and of the first and second side walls. The wading pool is located such as to allow water to outflow from the front wall into the main pool. In a specific example of implementation, the water basin is configured such that the water contained therein is shallower than 15 centimeters.
[0034] Advantageously, the wading pool can be added to an existing main pool and can also be easily removed. In addition, the wading pool is relatively shallow and therefore allows a user to sunbathe. Furthermore, the shallowness of the wading pool makes the wading pool very safe. Finally, water flowing over the front wall into the main pool creates a waterfall. Such a waterfall presents a strong aesthetic appeal to many pool users, and the sound of water falling into the main pool can also provide a calming sensation such as when using a lip at the base of said front wall to break the flow of water into rai-like dripping.
[0035] There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are additional features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto.
[0036] In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.
[0037] As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.
[0038] Further, the purpose of the foregoing abstract is to enable the U.S. Patent and Trademark Office and the public generally, and especially the scientists, engineers and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application. The abstract is neither intended to define the invention of the application, which is measured by the claims, nor is it intended to be limiting as to the scope of the invention in any way.
[0039] These together with other objects of the invention, along with 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 the specific objects attained by its uses, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0040] FIG. 1 Perspective view of the wading pool in context.
[0041] FIGS. 2 ab Perspective view of the wading pool and perspcertive view detail, respectively.
[0042] FIG. 3 Top view of the frame.
[0043] FIG. 4 Top view of the frame structure for the benches.
DETAILED DESCRIPTION
[0044] FIG. 1 shows a wading pool ( 10 ) retrofittable to a main pool ( 12 ). The wading pool ( 10 ) includes a water basin ( 14 ) part, a bench ( 16 ) structure, decorative panels ( 18 ), and a privacy wall ( 20 ). The decorative panels ( 18 ), and the privacy wall ( 20 ) are mechanically attached to the bench ( 16 ), and the bench ( 16 ) structure surrounds the water basin ( 14 ) so that the bench ( 16 ) along with the decorative panels ( 18 ), and the privacy wall ( 20 ) create a monolithic entity large and heavy enough to settle in a given place once assembled. To facilitate on-site assembly, the bench ( 16 ) along with the decorative panels ( 18 ), and the privacy wall ( 20 ) have been factory pre-cut and prepared with predrilled holes and adapted hardware so as to provide a kit that is easily assemblable by a weekend handyman. Additionally, the kit can include stairs ( 64 ) and a ramp ( 66 ). A lighting system could also be part of the available options.
[0045] The wading pool ( 10 ) is positioned slightly higher than the main pool ( 12 ) so as to provide a waterfall coming from over a front wall ( 30 ) which is lower than side walls ( 24 ) and ( 26 ) and a back wall ( 28 ). The base of the front wall ( 30 ) can be equipped with a protuberant lip ( 31 ) which breaks the flow of water from a continuous or semi continuous curtain of water into a rain-like dripping which provides a soothing fountainlike sound.
[0046] The water basin ( 14 ) includes a base ( 22 ), side walls ( 24 , 26 ), a back wall ( 28 ) and a front wall. All walls ( 24 , 26 , 28 ) extend upwardly from the base ( 22 ).
[0047] The water basin ( 14 ) is obviously designed to hold water and that impermeable characteristic can be obtained by two means, either by a flexible elastomer type material place to line the base ( 22 ) and walls ( 24 , 26 , 28 ) of the water basin ( 14 ) to which it is adhering to by way of adhesive means or the water basin ( 14 ) can be intrinsically impermeable if made of a waterproof material such as would be the case with fiberglass. Such waterproof types of construction and materials are well known in the art and will therefore not be described in further details herein.
[0048] FIGS. 1 and 3 show, the decorative panels ( 18 ) and the bench ( 16 ) surround the base ( 22 ) and the side walls ( 24 , 26 ) as well as the back wall ( 28 ). The privacy wall ( 20 ) extends upwardly from the water basin ( 14 ) and provides both privacy and a decorative element. In the wading pool ( 10 ), the privacy wall ( 20 ) has a plurality of privacy panels ( 21 ) attached to columns ( 23 ). The columns are echanically fastened into reinforcing beams ( 25 ) which provides structural integrity to properly hold teh columns ( 25 ) and also structural integrity to the bench ( 16 ) so that it will not cave in as people sit on it. The exact shape of the privacy wall ( 20 ) is not critical to the invention and many types of privacy walls ( 20 ) can be used without detracting from the invention. Also, although only one privacy wall ( 20 ) is shown on FIG. 1 , the wading pool 10 can include more than one privacy wall ( 20 ).
[0049] The decorative panels ( 18 ), the bench ( 16 ) and the privacy wall ( 20 ) can be made of wood or of any other suitable material. Such panels, benches and walls are well known in the art and will therefore not be further described. Also, covers ( 17 ) can be cut into the bench ( 16 ) to cover coolers ( 27 ) used for storing cold beverages and such when filled with ice. Some premium models could even have coolers ( 17 ) refrigerated as real refridgerators.
[0050] The bench ( 16 ) is located above the water basin ( 14 ) and overlaps over the water basin ( 14 ) so as to cover the water inlet ( 47 ) and the drain ( 50 ). All the decorative panels ( 18 ), as well as the bench ( 16 ) and the privacy wall ( 20 ) are made of wood. However, the reader skilled in the art will appreciate any other suitable material could be used as long as it can withstand water and outside weather if the wading pool is located outdoors.
[0051] The plumbing system includes a water inlet ( 47 ), and a water outlet ( 50 ). The water inlet ( 47 ) is connected to a filtration system (not shown) of the main pool ( 12 ). Alternatively, the water inlet ( 47 ) is connected to an independent filtration system. Methods and devices to connect an inlet to an existing water filtration system are known in the art and therefore will not be further described hereinbelow. The water inlet ( 47 ) comes in through the base ( 20 ) and uses any of a variety of commercially available nozzles, some of those nozzles even comprise a built-in lighting source. The water outlet ( 50 ) is merely a plugged hole taht is unplugged for drainage purposes such as when closing down the pool in the fall or for maintenance. The water flow coming from the water inlet ( 47 ) is selected to provide a predetermined discharge of water which will results in a waterfall flowing over the front wall ( 28 ).
[0052] The reader skilled in the art will appreciate that a lighting system is optional and can take many alternative forms.
[0053] Finally, the wading pool ( 10 ) can include an optional heating system (not shown in the drawings). The heating system is of a type well known in art and heats the water that is to be fed through the inlet ( 47 ). The heating system can be included into the wading pool ( 10 ) or, alternatively, if such a heating system is available for the main pool ( 12 ), the water flowing to the inlet ( 47 ) can pass through the heating system of the main pool ( 12 ) before reaching the inlet ( 47 ). The heating system can be switched on and off.
[0054] In a specific example of implementation, the wading pool ( 10 ) is provided to customers in the form of a kit including all the components of the wading pool ( 10 ) and an instruction booklet including assembly instructions for the wading pool ( 10 ). The components of the wading pool ( 10 ) can be either permanently assembled or releasably assembled. In this last case, the wading pool ( 10 ) can be easily disassembled for maintenance or when the user moves from a house to another one, for example.
[0055] In operation, the wading pool ( 10 ) has water coming through the water inlet ( 47 ), fills the basin ( 14 ), when the water level in the basin ( 14 ) reaches an upper limit of the front wall ( 30 ), water flows over and into the main pool ( 12 ).
[0056] Typically, the water level in the wading pool ( 10 ) is between 5 and 15 centimetres high. However, many other water levels are within the scope of the invention. In a specific example of implementation, the water level in the wading pool ( 10 ) is substantially equal to 10 centimetres. This water level allows a user to suntan within the wading pool ( 10 ). In addition to allowing the waterfall effect of the water falling into the main pool ( 12 ), the front wall ( 30 ) allows a user to rest a head on top of the front wall ( 30 ) while laying on the back in the water basin ( 14 ).
[0057] In a specific example of implementation, the water basin ( 14 ) is between 1 and 3 meters wide and between 1 and 3 meters long. However, other widths and lengths are within the scope of the invention.
[0058] The reader skilled in the art will appreciate that many variations to the wading pool ( 10 ) can be made without detracting from the spirit of the invention. For example, the wading pool ( 10 ) could be used with an above-ground pool. In that case, the wading pool ( 10 ) needs to be supported by a structure such that the wading pool ( 10 ) is higher than a wall of the above-ground pool. The supporting structure can optionally be surrounded be walls such as to provide a storage area for a user.
[0059] Although the wading pool ( 10 ) is substantially rectangular, the wading pool can take any shape, such as a circular shape, an oval shape and a polygonal shape, among others. In addition, all the components of the wading pool can be made of any suitable material, such as a polymer, for example.
[0060] In a variant not shown in the drawings, decorative panels provided over the main pool ( 12 ) extend into the main pool ( 12 ), thereby providing guidance for the positioning of the wading pool ( 10 ) with respect to the main pool ( 12 ).
[0061] In addition, the wading pool ( 10 ) can be provided with additional nozzles to allow the creation of a spa-type wading pool, while nozzles perpendicular to the base ( 22 ) allow the creation of fountains.
[0062] As to a further discussion of the manner of usage and operation of the present invention, the same should be apparent from the above description. Accordingly, no further discussion relating to the manner of usage and operation will be provided.
[0063] With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention.
[0064] Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.
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A wading pool retrofittable to a main pool, the wading pool being for containing water. The wading pool includes a plumbing system for providing the water and a water basin for receiving the water provided by the plumbing system. The water basin is defined by first and second side walls, a back wall and a front wall. The first and second side walls, the back wall and the front wall each have a respective height. The height of the front wall is substantially lower than the height of the back wall and than the height of the first and second side walls. The wading pool is located such as to allow water to outflow from the front wall into the main pool.
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CROSS REFERENCE
[0001] This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Patent Application No. 61/101,436, filed Sep. 30, 2008, the entirety of which is hereby expressly incorporated by reference herein.
FIELD
[0002] The present invention relates to an interactive unit for a pet and more particular to pet furniture capable of providing pet interaction while being of easy to assemble construction.
BACKGROUND
[0003] Domestic animals, particularly cats, like to perch on raised platforms as well as nest in boxes and enclosures. However, many of the current pet beds, cat houses and other types of pet furniture are heavy, hard to ship, or else made of flimsy material. In many instances, the units are sold to the consumer as fully assembled, which increases shipping costs. Where unassembled, the pet furniture may be assembled at home by the consumer, but may require tools and detailed directions that can be complicated for the average pet owner.
[0004] Thus, there is a need to provide improved pet furniture.
SUMMARY
[0005] The present invention is directed to pet furniture that can take the form of an assembly capable of being assembled without using any tools and which can be of modular construction for ease of construction. In one preferred embodiment, the pet furniture assembly includes a bed and can be oriented in a manner that provides a bunk where the bed is on top and is reversible to provide a nestable box where the bed can be disposed on the bottom. In another preferred embodiment, the pet furniture is configured to provide a multi-tiered maze that is particular well suited for domestic house cats.
[0006] In one embodiment, the pet furniture assembly is formed of a plurality of pairs of opposed walls that carry a platform that can be configured to provide a support surface for a pet, such as to enable the pet to perch, rest or sleep thereon. Each pair of adjacent walls is engageable during assembly in a manner that requires no tools. The platform is a panel that also is engaged to one or more of the walls in a manner that requires no tools. Releasable engagement enables disassembly if it is desired to stow the pet furniture away.
[0007] In one embodiment, there are a plurality of sidewalls that releasably engage each one of a plurality of end walls via a latching arrangement that can include a coupling extension that is disposed interiorly along a corner formed where each one of the sidewalls and end wall engage. Such a latching arrangement can include a latch receiver that can releasably receive an outwardly extending engagement arrangement that includes a post or the like that releasably yet securely engages the latch receiver during assembly. In one preferred embodiment, the latch receiver includes a bracket or plate constructed and arranged to engage and secure the engagement arrangement. In a preferred implementation, the latch receiver is a keyhole fitting that receives a post with an enlarged head.
[0008] The platform is a panel that includes a plurality of movable couplers that engage a plurality of the walls. For example, in one preferred embodiment, each coupler includes a movable finger that is extended outwardly to engage part of a corresponding one of the walls. In one embodiment, the finger is received in a recess formed in a corresponding one of the sidewalls while the platform is disposed on one or more locators carried by the sidewalls. In another embodiment, the panel is received in a slot in each sidewall that is located relative to a corresponding recess or pocket formed in the sidewall in which one of the coupling fingers is received. In one preferred embodiment, each coupler is a turn button whose rotatable finger is receivable in a channel formed in each sidewall that can be a rabbet.
[0009] In another preferred pet furniture embodiment, a first pair of opposed walls are joined via hinges to a second pair of opposed walls with one of the pairs of opposed walls being hinged to enable the entire assembly to be folded up into a compact stack. A platform that can be formed of a plurality of panels connected via another hinge cooperates with a latching arrangement to be releasably attachable when the first and second pairs of walls are unfolded into a platform support frame. The latching arrangement includes a plurality of clips that each releasably receive a dowel with the clips carried by one of the platform and frame and the dowels carried by the other one of the platform and frame. For example, in a preferred embodiment, each one of the platform panels carries a plurality of dowel underneath its top surface and one of the pairs of opposed walls has a plurality of inwardly extending dowels that underlie the platform during assembly so as to register with and be engaged by a corresponding one of the clips in attaching the platform to the frame. The platform can receive a pad, such as of a mattress, upon which a pet can perch, rest or lay.
[0010] In a still further preferred pet furniture embodiment, an enclosure is defined that includes a plurality of animal sized openings that permit pet entry within along with at least one divider that defines a plurality of maze passages or chambers that a pet inside the enclosure can explore. In one embodiment, the divider is horizontally disposed defining a plurality of vertically separated maze passages or chamber levels. In a preferred embodiment, the divider has at least one animal sized opening permitting a pet inside the maze to travel between maze passages or chambers.
[0011] Various other features, advantages and objects will be made apparent from the following detailed description and the drawings.
DRAWING DESCRIPTION
[0012] Preferred exemplary embodiments of the invention are illustrated in the accompanying drawings, in which like reference numerals represent like parts throughout, and in which:
[0013] FIG. 1 is a side perspective view of a first embodiment of pet furniture;
[0014] FIG. 2 is a top perspective view of the first pet furniture embodiment.
[0015] FIG. 3 is a perspective view of one sidewall of the pet furniture embodiment shown in FIGS. 1 and 2 ;
[0016] FIG. 4 is a perspective view of another sidewall of the pet furniture embodiment shown in FIGS. 1 and 2 ;
[0017] FIG. 5 is a perspective view of one end wall of the pet furniture embodiment shown in FIGS. 1 and 2 ;
[0018] FIG. 6 is a perspective view of another end wall of the pet furniture embodiment shown in FIGS. 1 and 2 ;
[0019] FIG. 7 is a perspective view of a top or bottom panel of the pet furniture embodiment shown in FIGS. 1 and 2 ;
[0020] FIG. 8 is a perspective view of the first pet furniture embodiment shown fully assembled and in a first orientation;
[0021] FIG. 9 is a perspective view of another implementation of the first pet furniture embodiment shown assembled and in a second orientation;
[0022] FIG. 10 is an exploded view of a roof overlying the first pet furniture embodiment;
[0023] FIG. 11 is a perspective view of the roof assembled to the first pet furniture embodiment;
[0024] FIG. 12 is a perspective view of a second embodiment of pet furniture in a completely disassembled condition;
[0025] FIG. 13 is a perspective view of second pet furniture embodiment in a partially assembled condition;
[0026] FIG. 14 is a perspective view of second pet furniture embodiment in an assembled condition;
[0027] FIG. 15 is a perspective view of a third embodiment of pet furniture that is a multi-tiered cat maze; and
[0028] FIG. 16 is a second perspective view of the third pet furniture embodiment.
[0029] Before explaining one or more embodiments of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments, which can be practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and should not be regarded as limiting.
DETAILED DESCRIPTION
[0030] FIGS. 1-9 illustrates a first embodiment of a pet furniture assembly 30 that can be configured for animal interaction and which also is configurable to provide housing, an enclosure that can be protective and/or a pet support, such as a bed. The pet furniture assembly 30 is of modular construction and capable of being assembled manually without using any tools. The pet furniture assembly 30 is particularly well-suited for use with domestic pets kept in a house, such as a cat or the like.
[0031] With specific reference to FIGS. 1 and 2 , the pet furniture assembly 30 is a box 32 that can be of elongate construction as shown having a pair of opposed and spaced apart sidewalls 34 , 36 attached to a pair of spaced apart and opposed end walls 38 , 40 with a panel 42 extending therebetween. One of the walls, such as end wall 38 , is configured with a passage 44 large enough to allow passage of a pet (not shown) therethrough permitting pet ingress and/or egress. As is best shown in FIGS. 2 and 7 , the passage 44 is a circular opening 46 formed in end wall 38 .
[0032] Each one of the sidewalls 34 , 36 is a generally rectangular board or panel made of a suitably strong and durable material, such as wood. Similarly, each one of the end walls 38 , 40 is of generally square or rectangular construction and also made of a suitably strong and durable material, such as wood. Finally, panel 42 is generally rectangular and also made of a suitably strong and durable material, such as wood. In one preferred embodiment, each one of the walls 34 - 40 and panel 42 are made of a pressed fiberboard, such as medium density fiberboard (MDF). If desired, one or more or all of these can be made of another type of material, such as plastic or the like.
[0033] As previously indicated, the pet furniture assembly 30 can be configured in a manner that entices or encourages pet interaction. For example, one or more of the walls can include one or more openings 48 of a size that at least permits a pet located inside or outside of the box 30 to see therethrough. In the preferred embodiment shown in FIGS. 1-9 , each one of the smaller sized openings 48 are sized large enough to allow a pet to insert a limb or portion thereof through the opening 48 . For example, where the pet is a domestic cat, openings 48 preferably are sized large enough to allow a cat to insert its paw therethrough. In addition, as is best shown in FIGS. 1 , 2 and 4 , each wall, e.g., sidewall 36 , equipped with such openings 48 has at least a plurality of adjacent openings 48 spaced close enough together to permit a paw of a cat to be inserted through one opening 48 while the cat looks through an adjacent opening 48 . In one embodiment, there is at least plurality of pairs, i.e., at least three, such openings 48 formed in at least one of the walls. For example, as is shown in FIGS. 1 , 2 and 4 , sidewall 36 has ten such openings 48 formed therein disposed in two groups of five openings 48 with each openings group having a pair of spaced apart openings 48 disposed adjacent an upper and lower portion of the sidewall 36 with a single opening 48 centrally disposed between the upper and lower pairs. This enables cats of various sizes to be able to extend a paw through one of the openings 48 while being able to look through an opening 48 located above it.
[0034] To further encourage or entice pet interaction, one of the walls, such as sidewall 36 , can be configured to accept a plaything 50 , such as a cat toy 52 carried by an elongate wand 54 that extends outwardly from the wall 36 . Other types of playthings that include other types of cat toys, such as feathers, balls, etc., can be used. To accommodate attachment of a plaything 50 to the wall 36 , the wall 36 has a plurality of plaything holders or anchors 53 that can be receptacles formed in the wall 36 . For example, each plaything holder 53 can include a threaded nut (not shown) embedded in the wall 36 that threadably receives a threaded stem of the wand 54 in attaching the plaything 50 to the wall.
[0035] With continued reference to FIGS. 1 and 2 , panel 42 is generally horizontally disposed and has an outer surface 56 upon which a pad 58 , such as a layer of fabric that can be of padded construction, can be disposed. The fabric layer 58 is shown in FIG. 2 as overlying the outer surface 56 of panel 42 . With reference to FIG. 1 , the pad 58 is disposed in a recess 60 formed by panel 42 and an edge 62 , 64 of the walls 34 - 40 that extends upwardly above the outer surface 56 of panel 42 . The upraised edges of walls 34 - 40 border an outside edge 66 of the pad 58 , such as in the manner shown in FIG. 2 . When the pet furniture assembly 30 is configured as shown in FIG. 2 with a pad 58 disposed on panel 42 , it provides a support surface that is enticing to a pet, such as a cat, to rest upon. Indeed, when configured as shown in FIG. 2 , this arrangement can provide a bed 68 upon which a cat can rest or even sleep.
[0036] When the pet furniture assembly 30 is oriented as shown in FIGS. 1 , 2 and 8 , box 32 forms a substantially enclosed enclosure 70 having three sides defined by walls 34 , 36 and 40 , a top defined by platform 42 , and a bottom formed by a support surface 72 , such as the ground or a floor, with passage 44 permitting a pet, e.g., cat, to enter or exit the enclosure 70 . The furniture assembly 30 is convertible by flipping it over 180° as shown in FIG. 9 such that the box 32 has an open top 74 with the platform 42 being disposed adjacent to and overlying support surface 72 . When disposed in the orientation shown in FIG. 9 , the surface 57 ( FIG. 7 ) of the panel 42 opposite surface 56 forms a floor upon which pad 58 can be placed defining an enclosed bed 76 in which a pet, such as a cat, can rest or even sleep. When oriented forming substantially enclosed enclosure 70 , one set of outer edges of the walls 34 - 40 rests on the support surface 72 and when flipped over oriented as an open top box, an opposite said of outer edges of the walls 34 - 40 rests on the support surface 72 .
[0037] With reference to FIGS. 3-7 , the pet furniture assembly 30 can be formed modularly of separate components, including the sidewalls 34 , 36 , the end walls 38 , 40 and the platform 42 that doubles as an enclosure ceiling when an assembled pet furniture assembly 30 is disposed in one position, such as the position shown in FIGS. 1 , 2 and 8 , and as a floor when the assembled pet furniture assembly 30 is disposed in an opposite position, such as the position shown in FIG. 9 . In a currently preferred embodiment, these separate components can be manually assembled without using any tools as discussed in more detail below.
[0038] FIGS. 3 and 4 , illustrate preferred but exemplary embodiments of respective sidewalls 34 , 36 and FIGS. 5 and 6 illustrate preferred but exemplary embodiments of respective end walls 38 , 40 . Each sidewall 34 , 36 has a respective interiorly disposed surface 78 , 80 configured so as to enable engagement with a portion of each one of the end walls 38 , 40 in a manner that securely and positively assembles them together. Likewise, each end wall 38 , 40 has a respective interiorly disposed surface 82 , 84 configured in a manner that enables engagement with a portion of each one of the sidewalls 34 , 36 .
[0039] In a preferred embodiment, a latching arrangement carried by one or both of sidewalls 34 , 36 and end walls 38 , 40 enables tool-less coupling therebetween during assembly of the pet furniture assembly 30 . The latching arrangement is constructed and arranged to facilitate attachment, including in a releasable manner, at or along the corners or corner edges where each sidewall 34 , 36 and each end wall 38 , 40 converge in forming respective corners of box 32 . As discussed in more detail below, each latching arrangement can include a coupling extension carried by one plurality of walls, such as end walls 38 , 40 used to facilitate engagement during assembly with a respective engagement portion of another plurality of walls, such as sidewalls 34 , 36 .
[0040] As is shown in FIGS. 5 and 6 , each end wall 38 , 40 carries a coupling extension 86 that carries at least one latch receiver 88 that releasably engages a respective engagement portion 90 that can extend outwardly from a corresponding one of the sidewalls 34 , 36 when assembling the walls together. In the preferred embodiment shown in FIGS. 5 and 6 , there is a plurality of spaced apart latch receivers 88 . In a preferred embodiment, each latch receiver 88 can be a bracket or plate, such as a keyhole fitting 92 having a keyhole slot 94 with an enlarged slot portion 96 at one end and a narrower slot portion 98 extending therefrom. Each keyhole fitting 92 is fixed to coupling extension 86 , such as by fasteners or the like.
[0041] Each coupling extension 86 is a flange 100 extending outwardly from a respective interior surface 82 , 84 of a corresponding end wall 38 , 40 adjacent an outer side edge, such as depicted in FIGS. 5 and 6 . In the preferred embodiment shown in FIGS. 5 and 6 , each flange 100 is formed by an elongate board that can be fixed to a corresponding end wall 38 , 40 , such as by using an adhesive, fasteners or the like. To help facilitate assembly, each keyhole fitting 92 can be recessed or otherwise disposed in a pocket 102 formed in the flange 100 to which it is attached.
[0042] As is shown in FIGS. 3 and 4 , each sidewall 34 , 36 has a plurality of engagement portions 90 that are each releasably and slidably received in a slot 94 of a corresponding keyhole fitting 92 during assembly. Each engagement portion 90 can be in the form of a post 104 that extends outwardly from a corresponding interior surface 78 , 80 of a respective sidewall 34 , 36 . In a currently preferred embodiment, each post 104 has an outwardly extending shank 106 with an enlarged head 108 disposed at its free end. During assembly, one of the sidewalls, e.g. sidewall 34 or 36 , is manually maneuvered relative to one of the end walls, e.g., end wall 38 or 40 , until the head 108 of each one of the engagement posts 104 along one side edge of the sidewall is received in the enlarged slot portion 96 of a corresponding keyhole slot 94 of respective fitting 92 . Relative manual movement between the sidewall and end wall causes each post 104 to slide along the slot 94 in which is received until its head 108 is received in the narrower portion 98 of the slot 94 thereby preventing disengagement.
[0043] Referring now to FIGS. 3 , 4 and 7 , panel 42 and a plurality of walls, e.g., sidewalls 34 , 40 , are assembled toollessly using a latching arrangement that employs a plurality of movable or displaceable couplers 110 that includes a finger 118 movable between a disengaged position, such as shown in FIG. 7 , during assembly to an engaged position where it extends outwardly from the panel 42 in assembling the panel 42 to at least a plurality of walls. As is shown in FIG. 7 , the panel 42 has at least a plurality of pairs, i.e., at least three, couplers 110 attached by a pivot 112 that can be a fastener or the like. Each one of the couplers 110 is disposed adjacent a respective side edge 114 , 116 of the panel 42 that is going to be disposed toward a corresponding one of the walls to which the panel 42 is being assembled. In one preferred exemplary embodiment, each one of the couplers 110 is a turn button.
[0044] With specific reference to FIGS. 3 and 4 , each one of the walls, e.g., sidewalls 34 , 36 , to which the panel 42 is attached during assembly includes a socket that is a recess 120 in which an outwardly extending portion of a corresponding one of the fingers 118 of coupler 110 is received when the finger 118 is manually moved from a disengaged position, such as that shown in FIG. 7 , to an engaged position where it extends outwardly beyond an adjacent side edge 114 or 116 during assembly. In a preferred embodiment, each recess 120 is an elongate rabbet or channel 124 formed in a corresponding surface 78 , 80 of respective sidewall 34 , 36 that extends adjacent and along one of its edges 126 .
[0045] To help facilitate panel assembly, each sidewall 34 , 36 can include a platform locator 122 upon which the panel 42 can be placed prior to moving each coupler finger 118 toward an engaged position where is received in a corresponding one of the recesses 120 . Each platform locator 122 extends outwardly and can be elongate so as to help locate and support the platform 42 during assembly along substantially the entire length of the platform 42 . In addition, after assembly, the platform locator 122 can help support the platform 42 , such as when a pet is resting or sleeping thereon. Each locator 122 is an elongate strut 128 fixed to a corresponding sidewall 34 , 36 such as by using an adhesive, fasteners or the like. In one embodiment, as is depicted in FIGS. 3 and 4 , each strut 128 is received in an elongate channel 130 that extends generally parallel to rabbet 124 but disposed outwardly of the rabbet 124 and edge 126 . Each strut 128 can be adhesively attached to corresponding sidewall 34 , 36 .
[0046] In another preferred embodiment, channel 130 of each sidewall 34 , 36 can be of a width about the same or greater than the cross sectional width of the platform 42 and extend all the way to one or both sidewall edges 132 , 134 so as to enable panel 42 to be received in each channel 130 during assembly. Each recess 120 is spaced above channel 130 so as to receive a respective coupler finger 118 during assembly to securely yet releasably assemble panel 42 to sidewalls 34 , 36 .
[0047] In assembly, a plurality of pairs of walls, such as sidewalls 34 , 36 and one of the end walls 38 or 40 , are assembled together such as in the manner described above resulting in the walls forming a U-shape. Thereafter, platform 42 is assembled, such as in the manner described above, before the last wall, such as the other one of the end walls 38 or 40 , is assembled. Finally, where a pad 58 is used, it is placed on one of the surfaces 56 or 57 of the platform 42 , depending upon which way the assembled assembly 30 is oriented.
[0048] In a preferred method of assembly, sidewalls 34 and 36 are each attached to one of the end walls 38 or 40 , by attaching one of the sidewalls, such as sidewall 34 , to the endwall and then attaching the other one of the sidewalls, such as sidewall 36 , to the endwall. After that, platform 42 is assembled by placing it on locator supports 122 and then rotating each coupling finger 118 to its outwardly extended position so it received in a corresponding recess 120 , such as channel 124 , in a respective one of the sidewalls 34 , 36 . Where locator supports 122 are lacking, platform 42 can be slid in slot 130 of each sidewall 34 , 36 from the end opposite the assembled end wall until the platform 42 is disposed adjacent or in abutment with the assembled end wall. Thereafter, the other end wall is attached to sidewalls 34 , 36 producing a pet furniture assembly 30 in accordance with that depicted in FIG. 1 . Of course, if desired pad 58 can be placed on platform 42 . If desired, the pet furniture assembly 30 can be flipped over and used as an open box type cat bed such as is depicted in FIG. 9 .
[0049] FIGS. 10 and 11 illustrate a preferred embodiment of a roof assembly 136 that can be of Gable roof construction formed of a panel arrangement 138 that can be formed of a first panel 140 attached or otherwise coupled to a second panel 142 at an angle relative thereto defining a hip 144 that is a top edge or apex of the roof 136 . The roof 136 is constructed and arranged to be mountable on an object, such as pet furniture assembly 30 shown in FIGS. 10 and 11 . For example, roof 136 can be constructed with a pair of outwardly extending legs 146 , 148 that engage a portion of pet furniture assembly 30 such that the roof 136 overlies a portion and preferably substantially all of the pet furniture assembly 30 .
[0050] In the embodiment shown in FIGS. 10 and 11 , the roof 136 is constructed and arranged to releasably engage pet furniture assembly 30 in a manner where it positively insecurely remains in place during use and operation. For example, as is shown in FIG. 10 , each leg 146 , 148 extends downwardly from a respective roof panel 140 , 142 and is configured in a manner where it is engageable with a corresponding outer edge of one of the walls of the pet furniture assembly 30 . In the embodiment shown in FIGS. 10 and 11 , each leg 146 , 148 carries a channel 160 that receives a corresponding outer edge of one of the walls of the pet furniture assembly 30 . Channel 160 has a generally U-shaped cross-section and can slidably and frictionally engage each wall alongside the outer edge of the wall. In the preferred embodiment shown in FIGS. 10 and 11 , each leg 146 , 148 has a channel 160 fixed thereto that receives an outer edge of a corresponding one of the end walls 38 , 40 .
[0051] The top or outer surface of the roof 136 can be covered with fabric or material 150 , such as sisal, on which a cat 152 can scratch its paws 154 , such as in the manner depicted in FIG. 11 when disposed on top of the roof. The roof overlies panel 42 and pad 58 of pet furniture assembly 30 and is spaced apart therefrom providing sufficient space 156 underneath so as to enable a cat 158 to perch, rest, or lay underneath such as is shown in FIG. 11 . In addition, such a roof assembly 136 can advantageously be used with the pet furniture assembly 30 whether oriented as shown in FIG. 11 or oriented as shown in FIG. 9 .
[0052] FIG. 12 illustrates another embodiment of a pet furniture assembly 170 that preferably is intended and configured for use by a cat, such as a common house cat. As shown in a disassembled condition, the pet furniture assembly 170 is compact for storage and shipping. This minimizes costs to the manufacturer, distributor and retailer.
[0053] The pet furniture assembly 170 includes a pair of collapsible/expandable wall sections 172 ( 22 ) defined by wall segments 174 , 176 attached by a hinge 178 to each other and by a hinge 180 to each end wall 182 as best shown in FIG. 13 . The assembly 170 includes a hinged panel assembly 184 made of a pair of panel halves 186 , 188 connected by a hinge 190 enabling the halves to be unfolded into a generally planar or flat panel that can form a top wall of the assembly 170 when assembly is completed, such as is shown in FIG. 14 , or can be configured to be a bottom wall (not shown), such as if the assembly is of reversible construction. Each panel half of the panel assembly 186 , 188 has a plurality of clips 192 that each engage dowels 194 that extend inwardly from each one of the wall segments 174 , 176 and dowels 196 that extend inwardly from each one of the end walls 182 , such as is shown in FIG. 13 .
[0054] As is also shown in FIGS. 12-14 , sidewall segments 174 , 176 each have legs 198 that define an archway-type opening 200 through which a cat can pass to go underneath panel assembly 184 when assembly is complete. The sidewalls can be connected to flanges 206 affixed to the right and left edges of the front and rear end walls 28 End walls 182 also have legs 202 between which a cat ingress/egress passage 204 is defined. A pad, such as a pad like mattress pad 58 , can be laid over the top of the panel assembly 184 when the pet furniture assembly 170 is assembled, such as in the manner depicted in FIG. 14 .
[0055] With reference generally to FIGS. 12-14 , the end walls 182 define arches for a cat to pass through to enter the inside of a nook or nesting area underneath the panel assembly 184 . The sidewalls 172 also have two entry points on either sidewall and the sidewalls 172 are able to fold inward about hinge 178 to allow the entire assembly 170 to collapse into a small storage space, for instance, under a person's bed or a couch. It may be important to a pet owner to be able to easily collapse the assembly 170 to hide it away at times. The sidewalls 172 are split into two sections 174 , 176 , as best shown in FIGS. 12 and 13 . The sidewalls 172 can be connected to flanges 206 affixed to the right and left edges of the front and rear end walls 182 . Knobs (not shown) may be affixed to sections of the pet bed walls in order to make collapsing or folding the pet bed easier during disassembly. Such knobs can also be used to facilitate assembly.
[0056] FIG. 14 shows the assembly 170 in a fully assembled condition. As shown, the side wall sections 174 , 176 have a hinge 178 that is centrally vertically oriented, so as to allow each sidewall 172 to fold in half about hinge 178 . The side wall sections 174 , 176 are attachable to the end walls 182 by build-out flanges 206 connected to at least one of the front and rear edge of each sidewall 172 and left and right edges of each end wall 182 to provide an abutment surface between end walls 182 and sidewalls 172 when the box shaped frame is being formed as is depicted by the progression shown in FIGS. 13 and 14 . A mattress support panel assembly 184 is supportable within the frame formed by the unfolded sidewall sections 174 , 176 (shown in FIG. 14 in the unfolded condition) and end walls 182 beneath an upper edge of the frame so that the frame can retain a mattress, e.g., pad 208 shown in phantom in FIG. 14 , against movement along the mattress support panel 184 when the mattress 208 is on either side of the mattress support panel.
[0057] FIGS. 15 and 16 illustrate another preferred embodiment of an article of pet furniture 210 that is a maze for one or more cats. The article of pet furniture 210 has a plurality of top panels 212 , 214 disposed at varying heights for enabling exploration by a cat. Each top panel 212 , 214 has at least one opening 216 , 218 sized large enough for a cat to pass through. There also is a pair of sidewalls 220 , 222 , only one of which is clearly shown, that each can have one opening and in the embodiment shown in FIGS. 15 and 16 have plurality of similarly sized cat openings 224 , 226 formed therein. There also can be a pair of end walls 228 , 230 , with at least one of the end walls having at least one cat-sized opening 232 ( FIG. 16 ) formed therein. In a preferred embodiment, each end wall 228 , 230 has such a cat sized opening 232 formed therein. There also is a vertically extending upper section intermediate end wall 234 that can also have a cat-sized opening (not shown) formed therein.
[0058] Helping to form such a maze with the assembly 210 is a generally horizontal divider panel 236 disposed inside the assembly 210 that divides the article into a larger lower cat exploration chamber or maze segment 238 and a smaller upper cat exploration chamber or maze segment 240 . The divider panel 236 also has at least one cat-sized opening 242 formed therein enabling a cat disposed inside the cat furniture article 210 to climb through the opening 242 from one chamber or segment 238 to the other chamber or segment 240 and vice versa. The cat furniture article 210 can also have a bottom 244 that can be formed of a panel or the like, which defines a floor for the bottom chamber 238 , which can extend part of the length of the article 210 or substantially the entire length if desired. Such a maze-like, multi-chambered cat furniture assembly 210 provides multiple areas of exploration for a cat and takes advantage of their natural curious tendencies in facilitating play and exercise.
[0059] A pet furniture assembly 210 in accordance with the present invention can be constructed in a manner like that of assembly 30 shown in FIGS. 1-9 and described above or in a manner like that of assembly 170 shown in FIGS. 12-14 and described above. If desired, the components of maze 210 can also be assembled in another manner.
[0060] Various alternatives are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter regarded as the invention. It is therefore also to be understood that, although the foregoing description and drawings describe and illustrate in detail one or more preferred embodiments of the present invention, to those skilled in the art to which the present invention relates the present disclosure will suggest many modifications and constructions as well as widely differing embodiments and applications without thereby departing from the spirit and scope of the invention.
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Pet furniture embodiments including one unit that is a bunk when in one orientation and which can be disposed in another orientation forming a nestable enclosure and another unit that includes a maze that can be of multi-level or multi-tiered construction. Assemblies and methods are disclosed for tool-less assembly including one unit utilizing a first tool-less latching arrangement for assembling walls and a second tool-less latching arrangement for assembling a platform upon which a pet can perch, rest or lay to walls when assembled and another unit with hingedly connected walls that include a pair of opposed walls formed by wall sections also hingedly joined enabling the walls to be unfolded from a compact stack during assembly to form a platform-supporting frame that can include one or more integrally formed passages that permit a pet to explore underneath the platform.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation in part of U.S. patent application Ser. No. 09/982,148 filed Oct. 18, 2001 and entitled “An Intervertebral Spacer Device Having Arch Shaped Spring Elements”, which is fully incorporated herein by reference.
FIELD OF THE INVENTION
This invention relates generally to a spinal implant assembly for implantation into the intervertebral space between adjacent vertebral bones to simultaneously provide stabilization and continued flexibility and proper anatomical motion.
BACKGROUND OF THE INVENTION
The bones and connective tissue of an adult human spinal column consists of more than 20 discrete bones coupled sequentially to one another by a tri-joint complex which consists of an anterior disc and the two posterior facet joints, the anterior discs of adjacent bones being cushioned by cartilage spacers referred to as intervertebral discs. These more than 20 bones are anatomically categorized as being members of one of four classifications: cervical, thoracic, lumbar, or sacral. The cervical portion of the spine, which comprises the top of the spine, up to the base of the skull, includes the first 7 vertebrae. The intermediate 12 bones are the thoracic vertebrae, and connect to the lower spine comprising the 5 lumbar vertebrae. The base of the spine is the sacral bones (including the coccyx). The component bones of the cervical spine are generally smaller than those of the thoracic spine, which are in turn smaller than those of the lumbar region. The sacral region connects laterally to the pelvis. While the sacral region is an integral part of the spine, for the purposes of fusion surgeries and for this disclosure, the word spine shall refer only to the cervical, thoracic, and lumbar regions.
The spinal column of bones is highly complex in that it includes over twenty bones coupled to one another, housing and protecting critical elements of the nervous system having innumerable peripheral nerves and circulatory bodies in close proximity. In spite of these complications, the spine is a highly flexible structure, capable of a high degree of curvature and twist in nearly every direction.
Genetic or developmental irregularities, trauma, chronic stress, tumors, and degenerative wear are a few of the causes which can result in spinal pathologies for which surgical intervention may be necessary. A variety of systems have been disclosed in the art which achieve immobilization and/or fusion of adjacent bones by implanting artificial assemblies in or on the spinal column. The region of the back which needs to be immobilized, as well as the individual variations in anatomy, determine the appropriate surgical protocol and implantation assembly. With respect to the failure of the intervertebral disc, the interbody fusion cage has generated substantial interest because it can be implanted laparoscopically into the anterior of the spine, thus reducing operating room time, patient recovery time, and scarification.
Referring now to FIGS. 1 and 2, in which a side perspective view of an intervertebral body cage and an anterior perspective view of a post implantation spinal column are shown, respectively, a more complete description of these devices of the prior art is herein provided. These cages 10 generally comprise tubular metal body 12 having an external surface threading 14 . They are inserted transverse to the axis of the spine 16 , into preformed cylindrical holes at the junction of adjacent vertebral bodies (in FIG. 2 the pair of cages 10 are inserted between the fifth lumbar vertebra (L 5 ) and the top of the sacrum (S 1 ). Two cages 10 are generally inserted side by side with the external threading 14 tapping into the lower surface of the vertebral bone above (L 5 ), and the upper surface of the vertebral bone (S 1 ) below. The cages 10 include holes 18 through which the adjacent bones are to grow. Additional material, for example autogenous bone graft materials, may be inserted into the hollow interior 20 of the cage 10 to incite or accelerate the growth of the bone into the cage. End caps (not shown) are often utilized to hold the bone graft material within the cage 10 .
These cages of the prior art have enjoyed medical success in promoting fusion and grossly approximating proper disc height. It is, however, important to note that the fusion of the adjacent bones is an incomplete solution to the underlying pathology as it does not cure the ailment, but rather simply masks the pathology under a stabilizing bridge of bone. This bone fusion limits the overall flexibility of the spinal column and artificially constrains the normal motion of the patient. This constraint can cause collateral injury to the patient's spine as additional stresses of motion, normally borne by the now-fused joint, are transferred onto the nearby facet joints and intervertebral discs. It would therefore, be a considerable advance in the art to provide an implant assembly which does not promote fusion, but, rather, which nearly completely mimics the biomechanical action of the natural disc cartilage, thereby permitting continued normal motion and stress distribution.
It is, therefore, an object of the present invention to provide a new and novel intervertebral spacer which stabilizes the spine without promoting a bone fusion across the intervertebral space.
It is further an object of the present invention to provide an implant device which stabilizes the spine while still permitting normal motion.
It is further an object of the present invention to provide a device for implantation into the intervertebral space which does not promote the abnormal distribution of biomechanical stresses on the patient's spine.
Other objects of the present invention not explicitly stated will be set forth and will be more clearly understood in conjunction with the descriptions of the preferred embodiments disclosed hereafter.
SUMMARY OF THE INVENTION
The preceding objects of the invention are achieved by the present invention which is a flexible intervertebral spacer device comprising a pair of spaced apart base plates, arranged in a substantially parallel planar alignment (or slightly offset relative to one another in accordance with proper lordotic angulation) and coupled to one another by means of at least one spring mechanism. This at least one spring mechanism provides a strong restoring force when a compressive load is applied to the plates, and may also permit limited rotation of the two plates relative to one another. While there are a wide variety of embodiments contemplated, one preferred embodiment is described herein as representative of preferred types.
More particularly, with respect to the base plates, which are largely similar in all embodiments, as the assembly is to be positioned between the facing surfaces of adjacent vertebral bodies, and as such need to have substantially flat external surfaces which seat against the opposing bone surfaces. Inasmuch as these bone surfaces are often concave, it is anticipated that the opposing plates may be convex in accordance with the average topology of the spinal anatomy. In addition, the plates are to mate with the bone surfaces in such a way as to not rotate relative thereto. (The plates rotate relative to one another, but not with respect to the bone surfaces to which they are each in contact with.) In order to prevent rotation of a plate relative to the bone, the upper and lower plates alternatively may each include outwardly directed spikes or ridges which penetrate the bone surface and mechanically hold the plates in place. However, it is more preferably anticipated that the plates should include a porous coating into which the bone of the vertebral body can grow. The most desirable upper and lower plate surface porous feature is a deflectable wire mesh into which the bone can readily grow, and which mesh will deform to seat into the concave upper and lower bone faces. (Note that this limited fusion of the bone to the base plate does not extend across the intervertebral space.) These features, while being preferred are not required.
Between the base plates, on the exterior of the device, there may also be included a circumferential wall which is resilient and which simply prevents vessels and tissues from entering within the interior of the device. This resilient wall may comprise a porous fabric or a semi-impermeable elastomeric material. Suitable tissue compatible materials meeting the simple mechanical requirements of flexibility and durability are prevalent in a number of medical fields including cardiovascular medicine, wherein such materials are utilized for venous and arterial wall repair, or for use with artificial valve replacements. Alternatively, suitable plastic materials are utilized in the surgical repair of gross damage to muscles and organs. Still further materials which could be utilized herein may be found in the field of orthopedic in conjunction with ligament and tendon repair. It is anticipated that future developments in this area will produce materials which are compatible for use with this invention, the breadth of which shall not be limited by the choice of such a material. For the purposes of this description, however, it shall be understood that such a circumferential wall is unnecessary, and in some instances may be a hindrance, and thusly is not included in the specific embodiment set forth hereinbelow.
As introduced above, the internal structure of the present invention comprises a spring member, or other equivalent subassembly which provides a restoring force when compressed. It is desirable that the restoring forces be directed outward against the opposing plates, when a compressive load is applied to the plates. More particularly, the restoring force providing subassembly comprises a slotted arch-shaped metal strip which is secured to the lower plate and against movement therefrom at its lateral ends. The slotted arched strips of metal comprise continuous flat ends and a slotted curvate central portion. The curvate central portion is curvate in two axes, and shall hereinafter be termed a domed arch. The central portion is curved along the long axis (the length of the strip) of the strip into an upside down U-shape. The central portion is further curved in the lateral direction (the width of the strip) such that the outer surface (the top of the upside down U-shape) is convex. Stated alternatively, the central curvate portion of the metal strip comprises a section of a hemispheric shell (or paraboloid, or other suitable geometric shape) which has been cut along two arcs which are parallel to, but on opposing sides of a diameter (great circles) of the surface.
The slots formed in the curvate portion permit the spring extend along the length of the strip from the junction with the flat lateral ends up to points near to the peak of the domed arch. These slots permit the spring to deflect more easily than a continuous structure, thus permitting the design to more nearly approximate the loading profile of naturally occurring intervertebral disc cartilage.
More particularly, the slotted domed arch portions of the strips deflect under loading, but provide a restoring force in opposition to the loading until they are permitted to regain their original shape. The restoring force of an arched strip of metal is proportional to the elastic properties of the material as well as the length and arc of the curvate central portion of the strip. The elasticity of the metal, which endures and counteracts the strain of the material, causes a deflection in the height of the arch.
In the preferred embodiment, the peak of the slotted domed arch further comprises a socket for flexibly coupling to a post member on the interior surface of the opposing plate. This socket is formed at the center of the central portion, which is an unslotted region. This post couples to the spring to form a ball and socket joint at the peak of the domed arch, which joint permits the plates to rotate relative to one another. This rotation may be constrained by the specific conformation of the joint such that the plates are free to rotate through only a range of angles.
More particularly, this embodiment comprises a pair of spaced apart base plates, one of which includes means for coupling the flat lateral ends of the domed arched spring thereto it (such as simple set screws). The other of the plates is similarly shaped, having a flat exterior surface (which may include a mesh or porous coating to permit bony ingrowth), but further includes a short central post portion which rises out of the interior face at a nearly perpendicular angle. The top of this short post portion includes a ball-shaped knob. The knob includes a central threaded axial bore which receives a small set screw. Prior to the insertion of the set screw, the ball-shaped head of the post can deflect radially inward (so that the ball-shaped knob contracts). The insertion of the set screw eliminates the capacity for this deflection.
As introduced above, the slotted domed arch spring is mounted to this ball-shaped knob in such a way that it may rotate freely through a range of angles equivalent to the fraction of normal human spine rotation (to mimic normal disc rotation). In order to couple with the post, the strip spring includes an socket which accommodates the ball-shaped portion of the post. More particularly, the socket includes a curvate volume having a substantially constant radius of curvature which is also substantially equivalent to the radius of the ball-shaped head of the post. The deflectability of the ball-shaped head of the post, prior to the insertion of the set screw, permits the head to be inserted into the interior volume at the center of the spring, and the washer to be rotated into the proper lordotic angulation. Subsequent introduction of the set screw into the axial bore of the post flexibly retains the head in the socket of the strip spring. This assembly provides ample spring-like performance with respect to axial compressive loads, as well as long cycle life to mimic the axial biomechanical performance of the normal human intervertebral disc.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side perspective view of an interbody fusion device of the prior art;
FIG. 2 is a front view of the anterior portion of the lumbo-sacral region of a human spine, into which a pair of interbody fusion devices of the type shown in FIG. 1 have been implanted;
FIGS. 3 a and 3 b are top views of the upper and lower opposing plates of one embodiment of the present invention;
FIGS. 4 a and 4 b are a side perspective view and a cross section view of a lower plate having a slotted domed arch-shaped strip spring including a central socket mounted thereto it; and
FIG. 5 is a side cross-section view of a second embodiment of the present invention which utilizes the elements shown in FIGS. 3 a, 3 b, 4 a, and 4 b.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
While the present invention will be described more fully hereinafter with reference to the accompanying drawings, in which particular embodiments and methods of implantation are shown, it is to be understood at the outset that persons skilled in the art may modify the invention herein described while achieving the functions and results of this invention. Accordingly, the descriptions which follow are to be understood as illustrative and exemplary of specific structures, aspects and features within the broad scope of the present invention and not as limiting of such broad scope. Like numbers refer to similar features of like elements throughout.
Referring now to FIGS. 3 a and 3 b, side cross-section views of the top and bottom plate members 100 a 100 b of a first embodiment of the present invention are shown. More particularly, in this embodiment, the upper and lower plates 100 a, 100 b are nearly identical. As the device is designed to be positioned between the facing surfaces of adjacent vertebral bodies, the plates include substantially flat surface portions 102 a, 102 b (see FIGS. 4 b and 5 ) which seat against the opposing bone surfaces. In addition, the plates are to mate with the bone surfaces in such a way as to not rotate relative thereto. It is, therefore, preferred that the plates should include a porous coating into which the bone of the vertebral body can grow. The most desirable upper and lower plate surface porous feature is a deflectable wire mesh into which the bone can readily grow, and which mesh 104 a, 104 b will deform to seat into the concave upper and lower bone faces. (Note that this limited fusion of the bone to the base plate does not extend across the intervertebral space.)
Plate 100 a further includes a single set of threaded holes 111 for receiving the set screws (shown in FIGS. 4 a and 4 b ) required to affix the lateral ends of the domed arch strip spring thereto it.
Referring now also to FIGS. 4 b and 5 , plate 100 b has a similar shaped to the plates described above, i.e., having a flat exterior surface 102 b which is designed to seat against the exposed opposing bone face in an intervertebral space, but plate 100 b further includes a short central post member 105 which rises out of the interior face 103 at a nearly perpendicular angle. The top of this short post member 105 includes a ball-shaped head 107 . The head 107 includes a central threaded axial bore 109 which extends down the post 105 . This threaded bore 109 is designed to receive a small set screw 101 . Prior to the insertion of the set screw 101 , the ball-shaped head 107 of the post 105 can deflect radially inward (so that the ball-shaped head contracts). The insertion of the set screw 101 eliminates the capacity for this deflection.
Referring now to FIGS. 4 a and 4 b, the domed arch strip spring 130 of this embodiment is shown in a side view and a cross-section view, respectively. As introduced above, the slotted arched strips of metal comprise flat ends 142 and a curvate central portion 144 . The curvate central portion 144 is curvate in two axes, and shall hereinafter be termed a domed arch 144 . The central portion 144 is curved along the long axis (the length of the strip) of the strip into an upside down U-shape. The central portion 144 is further curved in the lateral direction (the width of the strip) such that the outer surface (the top of the upside down U-shape) is convex. Stated alternatively, the central curvate portion 144 of the metal strip comprises a section of a hemispheric shell (or paraboloid, or other suitable geometric shape) which has been cut along two arcs which are parallel to, but on opposing sides of a diameter (great circles) of the surface.
The lateral ends 135 of the slotted domed arch springs include holes 137 through which set screws 139 may be introduced therethrough and into the set screw holes 111 in the plate 100 a to secure the spring 130 to the plate. The slots 147 of the slotted spring 130 are provided to render the springs more deflectable, thus mimicking the natural behavior of the cartilage of the human intervertebral disc.
This slotted domed arch strip spring 130 further includes the additional feature of having an enlarged central opening 132 . This central opening 132 includes a curvate volume 133 for receiving therein the ball-shaped head 107 of the post 105 of the lower plate 100 b described above. More particularly, the curvate volume 133 has a substantially constant radius of curvature which is also substantially equivalent to the radius of the ball-shaped head 107 of the post 105 .
Referring also to FIG. 5, in which the fully assembled second embodiment of the present invention is shown, the combination and assembly of this embodiment is now provided. The deflectability of the ball-shaped head 107 of the post 105 , prior to the insertion of the set screw 101 , permits the head 107 to be inserted into the interior volume 133 at the peak of the slotted domed arch strip spring 130 . Subsequent introduction of the set screw 101 into the axial bore 109 of the post 101 flexibly couples the head 107 to the spring 130 by virtue of the head 107 not being compressible and removable from the central volume 133 , but the post 105 being polyaxially retained in the socket 133 . Ideally the post head 107 is locked loosely enough within the central volume 133 of the spring 130 such that anatomically relevant rotation of the plates 100 a, 100 b remains viable. In alternative variation, however, it is possible to design the coupling such that the locking of the set screw 101 in the head 107 locks the assembly in one rotational orientation, preventing free rotation of the plates relative to one another. A combined embodiment may be one in which the set screw 101 may be selectively positioned in an unlocked (but still securing for the purpose of retention) and a locked orientation.
While there has been described and illustrated embodiments of an intervertebral spacer device, it will be apparent to those skilled in the art that variations and modifications are possible without deviating from the broad spirit and principle of the present invention. The present invention shall, therefore, not be limited solely to the specific embodiments disclosed herein.
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An intervertebral spacer device having a pair of opposing plates for seating against opposing vertebral bone surfaces, separated by a spring mechanism. The preferred spring mechanism is a slotted domed arch strip spring which is coupled to the upper plate by set screws. The spring includes a socket formed in the peak thereof and mounts onto a ball-shaped head extending outwardly from the lower plate. The spring and post members are thereby flexibly coupled such that the upper and lower plates may rotate relative to one another.
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BACKGROUND OF THE INVENTION
This invention relates, in general, to security devices, and, in particular, to a security device for a lap top computer
DESCRIPTION OF THE PRIOR ART
In the prior art various types of security devices have been proposed. For example, U.S. Pat. No. 5,757,616 to May et al discloses a locking bar for locking a display and system unit together. The device also prevents removal of peripheral devices and disables input from the keyboard and mouse.
U.S. Pat. No. 5,709,110 to Greenfield et al discloses a lap top security system comprising mounting plate affixed to the monitor housing and a cable which attaches to a table or counter top.
U.S. Pat. No. 5,787,738 to Brandt et al discloses a security lock for a computer comprising a blade which passes through the gap between the monitor and keyboard and which is fastened to a fixed object.
U.S. Pat. No. 5,595,074 to Munro discloses a desktop security locking station comprising a box and a clamping mechanism for securing the box to the computer. The box is then secured to a table top.
SUMMARY OF THE INVENTION
The present invention is directed to a lap top security device which has two adjustable arms and two fixed arms which engage with a lock and which adjust to fit different size computers to lock the computer closed. In addition one of the fixed arms has a loop so the security device can be attached to a fixed object.
It is an object of the present invention to provide a new and improved computer security device.
It is an object of the present invention to provide a new and improved computer security device which will secure a lap top computer in a closed position.
It is an object of the present invention to provide a new and improved computer security device which has provisions to secure the security device to a fixed object.
These and other objects and advantages of the present invention will be fully apparent from the following description, when taken in connection with the annexed drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top view of the present invention attached to a lap top computer.
FIG. 2 is a bottom view of the present invention attached to a lap top computer.
FIG. 3 is a top view of the locking device of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings in greater detail, FIG. 1 shows the locking device 1 of the present invention as it would be attached to a lap top computer, as seen from the top 2 of the computer. The locking device, as more clearly seen in FIG. 3, comprises four arms 4 , 5 , 6 , 7 which slide into a lock casing 3 and are lockingly retained therein. It should be noted that the arms 4 , 5 , 6 , 7 as shown in FIG. 3 are turned 90° from their operating position for clarity.
As seen in FIG. 1, the arm 4 is offset slightly from the arm 6 , which is directly opposite arm 4 . Likewise, arm 5 is offset slightly from the arm 7 which is directly opposite arm 5 , in order to prevent any interference between the arms as they enter the lock casing 3 . Also, arms 4 and 6 will be offset slightly from the arms 5 and 7 for the same reason.
The lock casing 3 is a conventional lock having a top, bottom and a plurality of sides with the arms extending from the sides which has projections inside which will engage the grooves 13 on the arms 4 , 5 , 6 , 7 and hold the arms within the casing 3 , therefore, no further description of the lock casing is necessary. The lock casing can have an aperture 14 to receive a key for unlocking the arms 4 , 5 , 6 , 7 so they can be disengaged from the casing 3 . It should be noted that it is not critical that the key hole 14 be on the top of the lock casing in order to work. It could also be placed on one of the sides of the lock casing 3 .
As shown in FIGS. 1 and 2, when the lap top computer is closed, the security device of the present invention can be secured to the closed lap top by positioning the arms 4 , 5 , 6 , 7 as shown and sliding the arms into the lock casing 3 where they will be secured against removal. The hook portions 8 of the arms will engage beneath the lap top, and will prevent any one, without a key from opening the lap top. Therefore, even if a thief takes the lap top they will be unable to open and use it. This will make it undesirable for someone to take the lap top. Also, securing the lap top in this manner will prevent anyone from accessing any information stored on the lap top.
As shown in FIGS. 2 and 3, at least one of the arms has a loop 9 attached thereto. As shown in FIG. 2, this loop, along with a cable 11 and a lock 12 can be used to secure the lap top 2 , 3 to a fixed object, such as a desk, by looping the cable around a portion of the desk and securing it by means of the lock 12 . This will increase the security of the lap top.
Although the Lap Top Lock and the method of using the same according to the present invention has been described in the foregoing specification with considerable details, it is to be understood that modifications may be made to the invention which do not exceed the scope of the appended claims and modified forms of the present invention done by others skilled in the art to which the invention pertains will be considered infringements of this invention when those modified forms fall within the claimed scope of this invention.
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A lap top security device which has two adjustable arms and two fixed arms which engage with a lock and which adjust to fit different size computers to lock the computer closed. In addition one of the fixed arms has a loop so the security device can be attached to a fixed object.
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FIELD OF THE INVENTION
The present invention relates to an apparatus for controlling a semi-active suspension system; and, more particularly, to an apparatus for controlling a semi-active suspension system using a variable damping force type shock absorber, wherein the damping force characteristics in rebound strokes and in compression strokes are controlled independently by means of separate control valves and utilizing a magneto-rheological fluid.
BACKGROUND OF THE INVENTION
In a semi-active suspension system for a vehicle, damping forces of respective shock absorbers are controlled independently by measuring the behavior of respective wheels by using, for example, vertical acceleration sensors installed at respective portions of the vehicle body adjacent to the shock absorbers.
As a control method for such a semi-active suspension system, the so-called “sky-hook” method is usually employed. This control method works as follows: when the direction of a vehicular vertical velocity is upward with respect to a road surface, the damping force characteristic in rebound strokes becomes hard, i.e., the damping force becomes relatively large, whereas the damping force characteristic in compression strokes becomes soft, i.e., the damping force becomes relatively small; and when a direction of a vehicular vertical velocity is downward with respect to a road surface, the damping force characteristic in rebound strokes becomes soft or relatively small, while the damping force characteristic in compression strokes becomes hard or relatively large.
Conventionally, two types of shock absorbers are employed for the semi-active suspension system. One is a reverse type semi-active damper and the other a normal type semi-active damper. In a suspension system using the reverse type semi-active dampers, the “sky-hook” control method can be applied by measuring vehicular vertical velocities only. However, the suspension system using reverse type semi-active dampers cannot offer an anti-roll control for preventing rolling behavior which occurs when a vehicle is steering. On the other hand, a suspension system using the normal type semi-active dampers can adopt the “sky-hook” control method as well as prevent the rolling behavior. However, in this system, vertical velocities of axles as well as vehicular vertical velocities should be measured, requiring more sensors than the suspension system using the reverse type semi-active dampers.
In order to solve these problems, an apparatus and a method for controlling damping force characteristic of a vehicular shock absorber and two types of shock absorbers therefor have been disclosed in U.S. Pat. No. 6,092,011. In order to control the damping force characteristics of the shock absorbers, a first type shock absorber uses a control valve driven by a stepping motor while a second type shock absorber uses throttling mechanisms driven by solenoid valves. However, in such a configuration, the damping force characteristics do not change continuously and their response times are not fast enough, which give performance restrictions.
As a shock absorber which has continuous damping force characteristics and response times fast enough, magneto-rheological fluid dampers (MR dampers) have been proposed in U.S. Pat. No. 5,277,281. However, no control method is provided in this patent.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to provide an apparatus for controlling a semi-active suspension system using a variable damping force type shock absorber, wherein damping force characteristics in rebound strokes and in compression strokes are controlled independently and MR fluids are utilized.
In accordance with a preferred embodiment of the present invention, there is provided an apparatus for controlling a semi-active suspension system of a vehicle including at least one shock absorber using a magneto-rheological fluid. The shock absorber has a rebound valve and a compression valve which are configured such that damping forces of the shock absorber generated in rebound strokes and compression strokes are controlled independently of each other. The apparatus comprises a normal driving control unit for determining a ride value (S ride ) as well as a filtered vehicular vertical velocity (v i ) based on a vehicular vertical acceleration; an anti-roll control unit for determining a roll value (S roll ) based on a velocity and a steering angle of the vehicle; and a damping force adjusting unit for controlling the rebound valve and the compression valve of the shock absorber based on the roll value (S roll ), the ride value (S ride ) and the filtered vehicular vertical velocity (v i ) under a predetermined condition.
A shock absorber which has a configuration such as shown in FIG. 10 ( c ) of U.S. Pat. No. 5,277,281 may be used for the apparatus for controlling a semi-active suspension system of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects and features of the present invention will become apparent from the following description of preferred embodiments given in conjunction with the accompanying drawings, in which:
FIG. 1 shows a schematic block diagram of an apparatus for controlling a semi-active suspension system in accordance with a preferred embodiment of the present invention;
FIG. 2 illustrates a block diagram of the normal driving control unit shown in FIG. 1; and
FIG. 3 describes a block diagram of the anti-roll control unit shown in FIG. 1 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.
FIG. 1 shows a schematic block diagram of an apparatus for controlling a semi-active suspension system in accordance with a preferred embodiment of the present invention. As shown in FIG. 1, the apparatus for controlling a semi-active suspension system comprises a normal driving control unit 10 , an anti-roll control unit 20 , a damping force adjusting unit 30 and sensors S 1 -S 6 .
The normal driving control unit 10 includes an integrator 11 , a ride value calculating part 12 and a filtering part 13 , as shown in FIG. 2 .
The integrator 11 is electrically connected to the vertical acceleration sensors S 1 , S 2 , S 3 and S 4 and receives vehicular vertical acceleration signals detected thereby. Vehicular vertical velocities v h are derived by performing integration in either z-domain or s-domain as follows: v h ( z ) a ( z ) = 0.00345 z 2 - 0.00345 z 2 - 1.969 z + 0.96968 (1z) v h ( s ) a ( s ) = s s 2 + 2 ζ 1 ω 1 s + w 1 2 (1s)
where a(z) or a(s) is the vehicular vertical acceleration.
During this process, low frequency components of the vehicular vertical acceleration signals are removed therefrom.
Next, powers of the respective vehicular vertical velocities are determined by calculating absolute values thereof and then filtering the absolute values through a low pass filter which has a cut-off frequency of 0.5 Hz as follows: v _ h ( z ) v p ( z ) = 0.01065 z + 0.01065 z - 0.97869 , where v p ( z ) = | v h ( z ) | (2z) v _ h ( s ) v p ( s ) = 1 T s + 1 , T = 0.325 , where v p ( s ) = | v h ( s ) | (2s)
Further, the vehicular vertical acceleration signals are filtered through a band pass filter and filtered vehicular vertical velocities are determined as follows: a 10 Hz ( z ) a ( z ) = 0.11179 z 2 - 0.11179 z 2 - 1.6125 z + 0.77642 (3z) a sq 10 Hz ( z ) = ( a 10 Hz ( z ) ) 2 (4z) a _ sq 10 Hz ( z ) a s q 10 Hz ( z ) = 0.06195 z + 0.06195 z - 0.87611 (5z) a 10 Hz ( s ) a ( s ) = 2 ζ 2 ω 2 s s 2 + 2 ζ 2 ω 2 s + ω 2 2 , ζ 2 = 0.3 , ω 2 = 10 × 2 π (3s) a s q 10 Hz ( s ) = ( a 10 Hz ( s ) ) 2 (4s) a _ sq 10 Hz ( z ) a s q 10 Hz ( z ) = 1 T s + 1 , T = 0.053 (5s) v i = v h 1 + K v · a _ sq 10 Hz (6)
where K v is a tuning variable, v i a filtered vertical velocity and the superscript 10 Hz bandwidth of a band pass 10 filter.
When the frequency of the vertical acceleration is high, the vehicular vertical velocity v h becomes relatively large and, when the frequency of the vertical acceleration is low, the vehicular vertical velocity v h becomes relatively small.
Then, ride value S ride is determined by the ride value calculating part 12 as follows:
S ride =K ride — reb ×{overscore (v)} h , when v i >0 (7)
S ride =K ride — comp ×{overscore (v)} h , when v i <0 (8)
where K ride — reb , K ride — comp are gains having predetermined values, respectively.
As shown in FIG. 3, the anti-roll control part 20 includes a steering rate detecting part 21 and a roll value calculating part 22 and is electrically connected to a steering angle sensor S 5 and a vehicle speed sensor S 6 .
First, signals detected by the sensors S 5 and S 6 are delivered into the steering rate detecting part 21 .
A rolling velocity of a vehicle is proportional to a lateral acceleration of the vehicle and the lateral acceleration can be determined by using a steering angle displacement and a vehicular velocity of the vehicle. The lateral acceleration of the vehicle is determined as follows: a y = V 2 l × 1 1 + ( V V ch ) 2 × δ . sw i s ( 9 )
where i s is a steering gear ratio, {dot over (δ)} sw a steering wheel angle ratio, l a length of wheel base, V a vehicular velocity and V ch a characteristic velocity of the vehicle.
Then, a time delay is taken into consideration for the lateral acceleration determined above as follows: a y d e l a y ( z ) a y ( z ) = 0.01720 z + 0.01720 z - 0.96560 (10z) a y d e l a y ( s ) a y ( s ) = 1 0.2 s + 1 (10s)
The roll value calculating part 22 calculates a roll value based on the lateral acceleration determined above as follows:
S roll =|K roll ·a y relay | (11)
where K roll is a gain having a predetermined value.
Typically, K roll is a function of a slip ratio λ and defined as follows: λ = r R ω R - r F ω F r R ω R ( 12 )
where r is radius of a tire, ω a angular velocity of a tire and a superscript F stands for front and R for rear, which will be the same hereinafter.
The damping force adjusting unit 30 receives the ride value S ride and the roll value S roll and determines an operation value S i . More specifically, when the roll value S roll is larger than 70, operation values S i . For front and rear shock absorbers are determined as follows:
S iR F =S iC F =K roll F ·S roll (13 F )
S iR R =S iC R =K roll R ·S roll (13 R )
where a subscript R stands for rebound and C for compression, which will be the same hereinafter.
On the other hand, when the roll value is smaller than or equal to 70, the operation value S i is determined as follows:
S i =v i ·S ride (14)
This operation value S i will be larger than zero when the vertical velocity is upward and smaller than zero when the vertical velocity is downward. In order to realize the “sky-hook” control, the operation values for the front and rear shock absorber are determined as follows:
S iR =S i , when S i >0 (15)
S iC =|S i |, when S i <0 (16)
Finally, current amounts for the respective MR dampers are determined as follows: A R = 3 · S i R 128 ( 17 ) A C = 3 · S i C 128 ( 18 )
where A is an amount of control current for the valves of the MR dampers.
When the operation values S iR or S iC are greater than 128, the currents are set as follows:
A R =3 (19)
A C =3 (20)
These currents are delivered to the rebound valve and the compression valve of MR dampers and damping force characteristics of each MR damper are controlled independently.
In the apparatus in accordance with the present invention, damping force characteristics are varied continuously and can be controlled independently in rebound strokes and compression strokes, respectively. Further, response times are fast enough to realize the required ride comfort and anti-roll control. Furthermore, an optimal contacting state of a vehicle can be established when the inventive apparatus is used with an anti-lock braking system (ABS) and the like.
Although the invention has been shown and described with respect to the preferred embodiments, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the following claims.
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An apparatus for controlling a semi-active suspension system of a vehicle including at least one shock absorber using magneto-rheological fluids. The shock absorber has a rebound valve and a compression valve which are configured such that damping forces of the shock absorber generated in rebound strokes and compression strokes being controlled independently. The apparatus comprises a normal driving control unit for determining a ride value (S ride ) and a filtered vehicular vertical velocity (v i ) based on a vertical vehicular acceleration, an anti-roll control unit for determining a roll value (S roll ) based on a velocity and a steering angle of the vehicle, and a damping force adjusting unit for controlling the rebound valve and the compression valve of the shock absorber based on the roll value (S roll ), the ride value (S ride ) and the filtered vehicular vertical velocity (v i ) under a predetermined condition.
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This application claims priority under 35 USC § 119(e)(1) of provisional application Ser. No. 60/028,645, filed Oct. 16, 1996.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to improvements in integrated circuits and integrated circuit techniques, and more particularly to improvements in ground bounce compensation circuits for use in integrated circuits and methods for constructing and using same.
2. Relevant Background
Numerous circuits are used in digital bipolar devices which address the problem of ground falling below zero volts as transistors are switched on and off. This phenomenon is referred to as "negative ground bounce," or "NGB." However, also of concern are instances in the operation of integrated circuits in which the ground potential increases to undesirably high positive levels. This may result in propagation of erroneous data, in some cases, and may result in the damage or destruction of sensitive integrated circuit components, as well. Nevertheless, providing a circuit that alleviates the problem of the ground potential increasing positively ("positive ground bounce", or "PGB") to undesirable high positive voltage levels has not been sufficiently addressed.
Although this problem exists in many integrated circuit configurations, it is especially pronounced in integrated circuit that are used to switch more than one output. In such embodiments, the ground potential tends to become unstable as current is driven into it simultaneously from mere than one output.
In some configurations, this problem has been addressed by the circuit designer taking measures to reduce the upward ground bounce. Examples of this approach can be seen in many bipolar digital octal devices, which include means for reducing the amount of voltage ground movement. Techniques such as reducing the amount of base drive to output NPN transistors and decreasing the output drive capability of these devices were commonly used. These approaches, however, usually sacrificed the AC speed performance of the circuit.
What is needed, therefore is a circuit that compensates for positive ground bounce or movement, which can be used in integrated circuits, in general, and in integrated circuits of the type that have more than one output, in particular.
SUMMARY OF THE INVENTION
In light of the above, therefore, it is an object of the invention to provide a circuit that compensates for positive ground bounce or movement, which can be used in integrated circuits, in general, and in integrated circuits of the type that have more than one output, in particular.
These and other objects, features and advantages of the invention will be apparent to those skilled in the art from the following detailed description of the invention, when read in conjunction with the accompanying drawings and appended claims.
According to a broad aspect of the invention, a circuit is provided for reducing positive ground bounce effects on an integrated circuit of the type having at least one integrated circuit transistor that has reduced conduction when. exposed to a positive ground bounce potential. The circuit includes circuitry responsive to an increase in ground potential to produce a drive current and circuitry for applying the drive current to the at least one integrated circuit transistor to oppose the reduced conduction. In the particular circuit embodiment, the positive ground bounce may be sufficient magnitude to switch the integrated circuit transistor off. Accordingly, the circuitry responsive to an increase in ground potential to produce a drive current produces a current of magnitude sufficient to prevent the integrated circuit transistor from switching off. In addition, the circuitry responsive to an increase in ground potential to produce a drive current and the circuitry for applying the drive current to the at least one integrated circuit transistor are integrated circuit devices.
More particularly, the circuitry responsive to an increase in ground potential to produce a drive current may include a ground bounce sense transistor of same conductivity type as the integrated circuit transistor and a circuit to bias the ground bounce sense transistor normally into conduction to pass a control current. Thus, the ground bounce sense transistor has reduced conduction when exposed to a positive ground bounce potential. A diode then redirects the control current to the integrated circuit transistor. The circuit to bias the ground bounce sense transistor may include a first resistor, a second resistor and a diode ladder connected between the first and second resistors. One end of the diode ladder is connected to the ground bounce sense transistor. If the integrated circuit also has additional integrated circuit transistors that have a reduced conduction when exposed to a positive ground bounce potential, the circuit may further include a second diode to redirect the control current additionally to the at least a second integrated circuit transistor.
According to another broad aspect of the invention, a circuit is presented for reducing positive ground bounce effects on an integrated circuit of the type having an integrated circuit output transistor that has reduced conduction during exposure to a positive ground bounce potential. The circuit includes a first current flow path between a voltage source and ground. The first current flow path includes a first resistor and a ground bounce sense transistor of the same conductivity type as the output integrated circuit transistor connected in series. A second current flow path between the voltage source and ground, includes, in series, a second resistor, a diode ladder, and a third resistor. A control element of the ground bounce sense transistor is connected to a node in the second current flow path. A diode is connected between a control element of the output integrated circuit transistor and the ground bounce sense transistor to divert current from the first current flow path to the output transistor in the event of a positive ground bounce. The output transistor and the ground bounce sense transistors may be bipolar transistors, and more particularly NPN transistors. Moreover, the ground bounce sense transistor, the second resistor, the diode ladder, the third resistor, and the diode may also be integrated circuit devices, integrated onto the same semiconductor substrate as the output transistor. If the circuit has additional integrated transistors that have reduced conduction during exposure to a positive ground bounce potential, a second diode may be provided. The second diode may be connected between a control element of the second integrated transistor and the ground bounce sense transistor.
According to yet another broad aspect of the invention, a method is presented for reducing positive ground bounce effects on an integrated circuit of the type having at least one integrated circuit transistor that has reduced conduction when exposed to a positive ground bounce potential. The method includes producing a drive current in response to an increase in ground potential and applying the drive current to the at least one integrated circuit transistor to oppose the reduced conduction. The step of producing a drive current in response to an increase in ground potential may be performed by producing a drive current of sufficient magnitude to prevent the integrated circuit transistor from switching off. Additionally, the step of producing a drive current in response to an increase in ground potential may be performed by providing a ground bounce sense transistor of same conductivity type as the integrated circuit transistor, a circuit to bias the ground bounce sense transistor normally into conduction to pass a control current and to allow the ground bounce sense transistor to have reduced conduction when exposed to a positive ground bounce potential, and a diode for redirecting the control current to the integrated circuit transistor.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is illustrated in the accompanying drawing in which:
FIG. 1 is an electrical schematic diagram of an integrated circuit which includes a positive ground bounce circuit in accordance with a preferred embodiment of the invention, for controlling positive ground bounce effects of an output transistor device in the integrated circuit.
FIG. 2 is an electrical circuit diagram of the circuit of FIG. 1, incorporating an embodiment of the positive ground bounce circuit in accordance with a preferred embodiment of the invention, for controlling positive ground bounce effects of another transistor devices in the circuit.
FIG. 3 is an electrical circuit diagram of an inverter circuit incorporating a positive ground bounce circuit, in accordance with another preferred embodiment of the invention.
And FIG. 4 is an electrical circuit diagram of a circuit incorporating a positive ground bounce circuit, in accordance with another preferred embodiment of the invention.
In the various figures of the drawing, like reference numerals are used to denote like or similar parts.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference now to FIG. 1, a circuit 10 that includes a positive ground bounce circuit 12 is constructed on a semiconductor substrate 14 as a part of an integrated circuit. It will be appreciated that other circuitry, not shown, would typically also be fabricated on the substrate 14 to perform other circuit functions. The circuit 10 shown in FIG. 1 additionally should be regarded as exemplary only. Those skilled in the art will recognize the application of the positive ground balance circuit 12 in other integrated circuit configurations.
The particular circuit 10 includes an input stage 19 having an input PNP transistor, 20 connected to a supply voltage, such as V CC , on a voltage supply bus 21 via a resistor 22, and to a reference potential on ground bus 44. The base of the transistor 20 is connected to receive the input signal on input line 24. The collector of a second input NPN transistor 26 is connected to the supply voltage bus 21 by a resistor 28. The emitter of the transistor 26 is connected to the input line 24 in which a Schottky diode 30 is connected in series. The base of the transistor 26 is connected to the emitter of the input transistor 20. A third input transistor 32 is provided, with its collector connected to the supply voltage bus 21 by a resistor 34, and its emitter connected to the base of an output transistor 40. The base of the transistor 32 is connected to the anode of the diode 30.
The output stage 41 of the circuit 10 includes an output transistor 40, which is an NPN device that provides an output signal on output line 42 connected to its collector. The emitter of the NPN transistor 40 is connected to the ground bus 44. A Schottky diode 46 and resistor 48 are connected in series between the base of the transistor 40 and the ground bus 44.
Additionally provided in the embodiment shown, between the input line 24 and ground bus 44 are PNP transistor 50 and NPN transistor 52. The base of the PNP transistor 50 is connected to the input line 24, and the base of the NPN transistor 52 is connected to the ground bus 44.
The positive ground bounce circuit 12 includes an NPN transistor 56, having its emitter connected to the ground bus 44 and its collector connected to the supply voltage bus 21 through a resistor 58. The base of the NPN transistor 56 is connected to a node 60 between a resistor 62, which is connected to the ground bus 44 and a string of series connected diodes 64-68, forming a diode ladder. The diode ladder is connected by a resistor 70 to the supply voltage line 21, to provide a first current flow path 69. In the embodiment shown, a Schottky diode 72 is connected between the collector of the transistor 56 and the base of the output transistor 40.
In operation, in response to a low-to-high transition on input line 24, for example, a switch from a low voltage (0v˜0.8v) to a high voltage (2v˜5v), transistors 26, 32, and 40 turn on. This can cause a lot of current to be forced into the ground bus 44 very quickly. The voltage of the ground bus 44 may effectively increase due to parasitic inductances that may exist in the circuit and package environment, resulting in "positive ground bounce" in the circuit and semiconductor substrate. This behavior is described by the relation ##EQU1## This positive ground bounce will, in turn, switch transistors 40 and 56 off. Since transistor 56 can no longer sink the current sourced through resistor 58, it will flow through diode 72, and into the base of transistor 40. This added current is sufficient to keep transistor 40 turned on, thus, preventing an unwanted interruption or perturbation in the output.
As the ground potential begins to recover to its normal level, it may undershoot below the 0v level. The positive ground circuit 12, however, allows the output transistor 56 to remain on, forcing the bias current away from transistor 40. It will be appreciated that this behavior of the positive ground bounce circuit 12 is desirable, because of the positive ground bounce circuit 12 only supplies current when it is needed.
On the other hand, in response to a high-to-low transition on the input line 24, the transistors 26, 32, and 40 are turned off. Again, the switching of the states of the transistors can cause a large amount of current to be "dumped" into ground. However, in this case, it does not matter if the ground potential rises, because transistor 40 is already in the cut-off mode, or off state, and the output signal on line 42 will not be affected. Once the ground potential rises, for example due to a current spike, it will try to recover (as mentioned above) and, in doing so, will bounce negatively. If ground swings sufficiently below 0v, the base of transistor 40 will look like a "good" high, and transistor 40 will start to conduct. This is, of course, an unwanted circuit reaction, but can be handled by known negative ground bounce circuits, not shown.
The temperature considerations of the circuit 10 are as follows. At low temperatures, for example, less than room temperature, the voltage across the diode ladder from the resistor 70 to the base of transistor 56 will be sufficiently high to keep transistor 56 turned off at a DC state, and drive the current bias into the base of transistor 40. If the input on line 24 is in a high state, this poses no problem because transistor 40 should be turned on. However, if input on line 24 is held low, transistor 40 should remain off with the addition of a Schottky diode 74 between the collector of the transistor 56 and the input line 24, as shown in FIG. 2. This will supply an added current to the input equivalent to: ##EQU2##
For example, the Advanced Schottky (AS) family of devices has this parameter tested with V CC =5.5v and V(IN)=0.4v. If resistor 58 is 25 KΩ, the extra current is approximately 180 μA. A typical data sheet maximum specification for this technology is 500 μA.
At high temperatures, for example, greater than room temperature, the voltage of the base-emitter junction of bipolar transistors tends to decrease. This forces a higher potential across the resistor 70 above the diode ladder 64-68, and, thus, more base drive for transistor 56. This may require a slightly stronger positive ground bounce to initiate its functionality.
With respect to the current considerations of the circuits 10 and 10' shown in FIGS. 1 and 2, assuming that resistor 58=25 KΩ, resistor 70=20 KΩ and V CC =5.5v, at room temperature one can expect the following DC current performance: ##EQU3##
I.sub.RESISTOR 70 =(V.sub.CC -5*V.sub.be -V.sub.schot)*Resistor 70=75 μA
I.sub.POSITIVE GROUND BOUNCE CIRCUIT 12 ≅290 μA
Including the positive ground bounce circuit in an octal device will increase the total I CC current about 2.3 mA. In many digital bipolar devices this does not pose any problem.
An example of another application in which the ground bounce circuit may be incorporated is shown in FIG. 3. The circuit 80 is an inverter of the type typically used as control circuitry for many digital bipolar devices. Often, for example, the signal on the output line 82 is connected to an NPN transistor emitter. If the signal on the output line 82 were not clamped by the positive ground bounce circuit 84, its voltage may rise very close to V CC , which could cause a breakdown from the emitter to collector of the conducting transistor.
The circuit 80 includes an input stage 86 having a PNP transistor 88 to receive the input signal on input line 90 on its base. The emitter is connected to V CC by a resistor 92. The collector is connected to the ground bus 94. In addition, transistors 96 and 98 are each connected between the input line 90 and the ground bus 94. The base of the PNP transistor 96 is connected to the input line 90, and the base of the NPN transistor 98 is connected to the ground bus 94.
The input stage 86, additionally, has an NPN transistor 100, having its base connected to the emitter of the input transistor 88 and its collector connected to the V CC bus by a resistor 102. The emitter of the transistor 100 is connected to the input line segment 104 which is connected to the output stage 106 of the inverter circuit 80. A Schottky diode 108 is connected between the line segment 104 and the input line 90.
The output stage 106 includes a Darlington connected transistor pair 110 connected between V CC and the output line 82. The input to the Darlington pair 110 is by way of the base of the first transistor 112, which is connected to a current flow path that includes a resistor 114, an NPN transistor 116, and an NPN transistor 118. The emitter of the transistor 116 is connected to the base of a low-side output NPN transistor 120. Thus, in its operation, it can be seen that current is provided to the output line 82 by the Darlington pair 110, and current is sinked from the output line 82 by the NPN transistor 120, in known push-pull manner.
The positive ground bounce circuit 84 includes a first current path 130 which includes a resistor 128, a diode ladder that includes a number of series connected diodes 132-136, and a resistor 138, between the V CC bus 93 and the ground bus 94. The ground bounce circuit 84, additionally, has a second current flow path that includes a resistor 140 in series with an NPN transistor 144 connected between the V CC bus 93 and the ground bus 94.
A Schottky diode 146 is connected between the collector of the transistor 144 and the base of the transistor 116 of the output stage. In addition, a diode 148 is connected between the collector of the transistor 116 of the output stage 106 and the node 150 between the diodes 133 and 134 of the diode ladder in the first current path 130. The diode 148, in conjunction with the diode ladder of the first current path 130, prevents the rise in voltage of the conducting transistor as mentioned above. It should be noted that the circuit configuration of FIG. 3 does not require a Schottky diode connected to the input since the base of the transistor 116 has a voltage potential of 2 V be 's above ground when transistors 116 and 120 are turned on. The transistor 144, diode 146, in conjunction with the first current path 130 provides the positive ground bounce protection in the same manner as above-described with reference to FIGS. 1 and 2.
The positive ground bounce circuit, in accordance with the invention, may be used to control an opposite phase voltage from that described in FIG. 2, an example of which is shown in FIG. 4. The circuit 200 shown in FIG. 4 has an input stage 202 that receives an input signal on input line 204 to an input transistor 206. The input transistor 206 is connected between a V CC bus 208 and a ground bus 210, and is connected in series with a resistor 212. A PNP transistor 214 is connected between the input line 204 and the ground bus 210, and, similarly, and NPN transistor 216 is connected between the input line 204 and the ground bus 210. The base of the PNP transistor 214 is connected to the input line 204, and the base of the NPN transistor 216 is connected to the ground bus 210.
The input stage 202, additionally, has three NPN transistors 220, 222, and 224. The NPN transistor 220 is connected in series with a resistor 226 between the V CC bus 208 and the input line 204 via a Schottky diode 228. The emitter of the NPN transistor 220 is connected to the base of the NPN transistor 222, which is connected in series with resistors 230 and 232 between the V CC bus 208 and the ground bus 210. The NPN transistor 224 has its base connected to the emitter of the NPN transistor 222, and its emitter connected to the ground bus 210. The collector of the NPN transistor 224 is connected via a Schottky diode 240 to the collector of an NPN transistor 242 and the positive ground bounce circuit 244, below described in detail.
The output stage 248 includes two NPN transistors 250 and 252. The NPN transistor 250 is connected in a current flow path which includes, in series, a resistor 254, a diode 256 and a resistor 258, between the V CC bus 208 and the ground bus 210. The emitter of the NPN transistor 250 is connected to the base of the NPN transistor 252, the collector of which being connected to the output line 260 and the emitter of which being connected to the ground bus 210.
The positive ground bounce circuit 244 includes a first current flow path 270, which includes a resistor 272, a diode ladder that includes a plurality of diodes 274-278, and a resistor 280, connected between the V CC bus 208 and the ground bus 210. The ground bounce circuit 244 also contains a second current flow path 282, which includes a resistor 284 connected in series with the NPN transistor 242 mentioned above. A Schottky diode 288 is connected between the collector of the NPN transistor 242 and the base of the output NPN transistor 250.
The operation of the positive ground bounce circuit 244 is similar to that described above with reference to FIGS. 1 and 2, except that the transistor 250 is protected against the effects of a positive ground bounce. It should be noted, of course, that the protection of transistor 250 results also in the protection of the output transistor 252.
It should be appreciated that in many applications, such as an output subcircuit voltage clamp as shown in FIG. 3, the design of the positive ground bounce circuit of the type herein described enables a reduction in element count. This decrease will directly impact chip area, resulting, ultimately, in a cost savings. Thus, through the use of positive ground bounce circuit of the type herein described, valuable silicon area can be saved, in turn, enabling more devices per wafer to be realized. Moreover, devices can be designed with faster AC output specifications because ground current spikes produced from fast switching transistors can be controlled better with such a circuit. Also, devices can be designed with larger output current drive capability without experiencing perturbations when simulating simultaneous output switching.
Although the invention has been described and illustrated with a certain degree of particularity, it is understood that the present disclosure has been made only by way of example, and that numerous changes in the combination and arrangement of parts can be resorted to by those skilled in the art without departing from the spirit and scope of the invention, as hereinafter claimed.
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A circuit (12) for reducing positive ground bounce effects on an integrated circuit (10) of the type having an integrated circuit transistor (40) that has reduced conduction when exposed to a positive ground bounce potential includes circuitry responsive to an increase in ground potential to produce a drive current and circuitry for applying the drive current to the integrated circuit transistor (40) to oppose the reduced conduction. The positive ground bounce circuit (12) has a ground bounce sense transistor (56) of same conductivity type as the integrated circuit transistor (40), and a circuit (69) to bias the ground bounce sense transistor (56) normally into conduction to pass a control current. Since ground bounce sense transistor (56) also has reduced conduction when exposed to a positive ground bounce potential, a diode (72) is provided to redirect the control current to the integrated circuit transistor (40), thereby reducing the effects of a positive ground bounce condition.
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This is a division of application Ser. No. 244,436, filed Mar. 16, 1981, now U.S. Pat. No. 4,424,810.
BACKGROUND OF THE INVENTION
The present invention relates to hemostatic clips and clip appliers, and, more particularly, to hemostatic clips fabricated from absorbable or nonabsorbable polymeric materials and to instruments for applying such clips to blood vessels and the like.
Hemostatic clips are utilized in surgical procedures to close severed blood vessels and other small fluid ducts. In the past, hemostatic clips have been narrow U-shaped or V-shaped strips formed of tantalum or stainless steel which are capable of being deformed and possess sufficient strength to retain the deformation when clamped about a blood vessel. The clips are generally applied using a forceps-type device having jaws channeled or otherwise adapted to hold the open clip. Representative hemostatic clips and appliers of the prior art are best illustrated in U.S. Pat. Nos. 3,867,944; 3,631,707; 3,439,523; 3,439,522; 3,363,628; 3,312,216; and 3,270,745.
It has been suggested in the prior art, as in U.S. Pat. No. 3,439,523, for example, that hemostatic clips might be formed of inexpensive plastics or materials which are slowly absorbable in the body. Unfortunately, conventional U- and V-shaped hemostatic clips do not possess the required strength or deformability when constructed of known plastic materials to be successfully clamped about a blood vessel. Thus, although the need and desirability of providing inexpensive plastic ligating clips on both absorbable and nonabsorbable materials has been recognized for over ten years, there has been no practical way to satisfy this need.
U.S. Pat. No. 3,926,195 describes a small, plastic clip designed for the temporary or permanent close of the oviduct and vas deferens in humans. These clips preferably have a clamping surface of from 6 to 10 mm in length and 3 to 6 mm in width. The size of such clips are accordingly considerably larger than is desirable for hemostatic clips. Additionally, clips of U.S. Pat. No. 3,926,195 require the use of several complex tools to apply the clips which are acceptable for the purposes described in the reference but would be unacceptable in a surgical procedure requiring the rapid placement of a large number of hemostatic clips to stem the flow of blood from severed vessels.
It is accordingly an object of the present invention to provide a plastic ligating clip effective for clamping off small blood vessels and other fluid ducts in the body. It is a further object of this invention to provide plastic ligating clips of both absorbable and nonabsorbable materials. It is yet a further object of this invention to provide plastic ligating clips which are quickly and easily applied to severed blood vessels and other fluid ducts with a single forceps-type instrument such as those used in applying metallic clips.
SUMMARY
The ligating clips of the present invention comprise two legs joined at the proximal ends thereof along a line forming a resilient hinge, with the first leg terminating in a deflectable hook member adapted to engage the distal end of the second leg. Each leg is provided with an indentation extending across the width of the leg near the distal end thereof. The indentation on the second leg is spaced from the distal end thereof by a distance equal to the depth of the hook member of the first leg. The indentation on the first leg is aligned with the indentation on the second leg so that the major axis along the length of the clip is normal to the minor axis extending through each indentation when the clip is closed and locked.
The applier for the clips of the present invention is a forceps-type instrument wherein each jaw is channeled to receive the width and length of the clip and a flange is provided across the base of each channel to engage the indentation on each leg of the clip. The depth of the channel in each jaw forward of the flange (between the flange and the tip of the jaw) is greater than to the rear of the flange. When the open clip is placed between the jaws of the applier, it is held firmly in place with the indentation of each leg engaged by the flange of each jaw. As the jaws are closed, the clip is maintained in position in the applier by the engagement of the indentations by the flanges and the distal end of the second leg bypasses and locks under the hook member of the first leg.
The clips may be formed of plastic by injection molding or other suitable technique, and may be composed of a nonabsorbable material such as polypropylene or an absorbable material such as a homopolymer or copolymer of lactide and glycolide. The clips are formed in a normally open position and constructed with a small amount of material to minimize tissue reaction. The clips are readily applied with a forceps-type applier using conventional surgical techniques.
DESCRIPTION OF DRAWINGS
FIG. 1 is a greatly enlarged view in perspective of a surgical clip according to the present invention.
FIG. 2 illustrates the clip of FIG. 1 clamped about a blood vessel.
FIG. 3 illustrates a forceps-type applier useful with the clips of the present invention.
FIG. 4 illustrates the open clip of FIG. 1 retained in the jaws of a forceps-type clip applier.
FIG. 5 illustrates the clip of FIG. 4 closed and locked over a blood vessel in the jaws of the applier.
FIG. 6 illustrates an alternate construction of the jaws of the forceps-type clip applier.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now to FIG. 1, there is illustrated hemostatic clip 10 constructed of two leg segments 11 and 12 connected at the proximal ends thereof by hinge section 13. Leg 11 terminates at the distal end thereof in hook member 14 having inner face 15 substantially parallel to inner face 16 of leg 11 and forming an acute angle with end face 17. Leg member 12 terminates at the distal end in end face 19 which forms an obtuse angle with inner face 18 of leg 12. End face 19 is offset at 23 to form a notch approximately midway between surfaces 18 and 20, and additionally is squared off at face 25 to form a substantially right angle with surface 20.
The length and width of faces 16 and 18 are substantially equal, and face 15 of hook 14 is spaced from face 16 of leg 11 by a distance corresponding to the thickness of leg 12 between the plane of face 18 and surface 20. When legs 11 and 12 are pivoted about hinge 13 to bring faces 18 and 16 into opposition, hook 14 is deflected by surface 19 of leg 12 until the distal end of leg 12 snaps under hook 14 and is thereby locked in place. End face 17 of hook 14 and end face 19 of leg 12 are angled as illustrated to facilitate the passage of leg 12 past hook 14 during clip closure.
When the clip is closed over a tubular vessel as illustrated in FIG. 2, surfaces 16 and 18 engage and compress vessel 27 to close the lumen thereof. Surfaces 16 and 18 may be smooth as illustrated in FIG. 1, or may be provided with ridges or grooves to increase vessel holding power. Leg 11 may also be undercut at the juncture of hook member 14 and surface 16 as illustrated at 26 in FIG. 1 to increase the deflectability of hook member 14 and increase the space between the hook member 14 and leg 11, thereby compensating for any inward deflection of hook 14 during closure which might reduce the clearance between surfaces 15 and 16 and otherwise interfere with the latching of the clip.
Referring again to FIG. 1, leg 12 of clip 10 includes an indentation 21 extending across the width of the leg near the distal end thereof. Indentation 21 is spaced from surface 25 a distance sufficient to permit full engagement of hook member 14 by leg 12 when the clip is in a closed position using an applier having a flange which engages the indentations of the clip. Indentations 21 and 22 are equidistant from hinge means 13 so that when the clip is closed, indentations 21 and 22 define a line perpendicular to the major axis along the length of the clip as best illustrated in FIG. 5.
The distal end of leg 12 forward of indentation 21 is of reduced thickness relative to the thickness immediately to the rear of indentation 21, thereby forming step 24 between indentations 21 and surface 20. The significance of this clip configuration will be appreciated in connection with the instrument used to apply and close the clip as illustrated in FIGS. 3 through 5.
FIG. 3 illustrates a forceps-type ligating clip applier 30 comprising two handle members 31 and 32 crossing at hinge point 33 and maintained in a normally open position by spring 38. Handle 31 extends beyond hinge 33 forming jaw member 34 while the extension of handle 32 forms jaw member 35.
FIG. 4 illustrates the detail of the construction of jaws 34 and 35 and the interaction of the jaws with the clip of FIG. 1. Jaws 34 and 35 are of identical design and are provided respectively with channels 36 and 37 extending rearwardly from the tips of the jaws. Each channel is provided with a flange 38 and 39 respectively across the width of the channel and near the distal end thereof. Flanges 38 and 39 are in alignment when the jaws of the applier are closed and are sized to engage the indentations 21 and 22 of the clip. Channels 36 and 37 forward of flanges 38 and 39 are deeper than to the rear of the flanges as illustrated in FIG. 4. When the open clip is held in the applier, the indentations on the clip are engaged by the flanges in each jaw. Due to the angle of the clip in the applier, the distal ends of legs 11 and 12 extend into the deeper forward channel section of each jaw. The reduced thickness of leg 12 at the distal tip prevents interference between the tip and the channel of the applier when the clip is held in the open position as illustrated in FIG. 4. Also, the raised shoulder 42 facilitates the lifting or pulling of the clip as from a cartridge or similar clip receptacle when loading the applier.
Clip 10 is initially loaded in applier 30 in the open position as illustrated in FIG. 4. After moving the jaws of the applier and the clip into position over the vessel to be ligated, the jaws of the applier are closed and the clip is locked in position over the vessel as illustrated in FIG. 5. As the clip is closed, the indentations of legs 11 and 12 are engaged by flanges of jaws 37 and 38 and maintained in position in the applier until the outer surface of leg 12 rests on the base of channel 36 as illustrated in FIG. 5. At this point, the distal end of leg 12 has rotated away from the base of the channel and sufficient space exists for hook 14 to bypass leg 12 and latch over the outer surface thereof. After the clip has been securely latched over the vessel to be ligated, the jaws of the applier are opened to release the clip and vessel and a new clip is loaded in the applier. Since the jaws of the applier are identical, it is not necessary to orient the applier to the clip when loading the applier.
FIG. 5 illustrates an alternative construction of the jaws of the applier, wherein the flange or projection in the channel of the applier is constructed by fixing a rivet 40 in a hole 41 disposed in the channel of each jaw of the applier. The hole may extend into the jaw of the applier or may extend entirely therethrough.
Many variations in the clip design other than the embodiments disclosed herein will be apparent to those skilled in the art and are contemplated within the scope of the present invention. For example, the undercut at the juncture of hook 14 and surface 16 of leg 11 may be omitted, and the inner surface of leg 12 may be beveled at the distal end as indicated by broken line a in FIG. 1 to compensate for downward deflection of hook 14 during closure which might reduce the clearance under face 15 and interfere with the latching of leg 12. Offset 23 in end face 19 of leg 12 provides an intermediate latching position and effectively increases the length of face 18 at the distal end of leg 12, but may be omitted if desired. These and other modifications in the configuration of the clip may be employed without departing from the spirit and scope of the present invention.
The clips of the present invention may be constructed in various sizes according to their intended function. Hemostatic clips are typically less than 6 mm in length, about 1.5 mm in width, and have a vessel clamping surface about 3 mm in length. The dimensions of the clip may be reduced by about 50 percent for certain applications in microsurgery. Larger clips for special hemostatic applications and other functions such as closure of oviducts or vas deferens may have dimensions of about double those of a typical hemostatic clip. The various sizes of clips are preferably matched with individual appliers having jaws tailored to the size of the clip for best performance.
The clips of the present invention are most conveniently molded of biologically acceptable plastic materials which may be absorbable or nonabsorbable. Preferred absorbable polymers include homopolymers and copolymers of glycolide and lactide, and poly(p-dioxanone). Preferred nonabsorbable polymers include nylon and polypropylene. All these materials have been demonstrated to be biologically acceptable when used as sutures or other implantable medical devices. The clips may also be cast or machined from solid polymeric materials or from metals such as aluminum, magnesium, stainless steel, tantalum, and various alloys of these, some of which may also be absorbable in biological tissue.
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Plastic ligating clips of absorbable or nonabsorbable materials are formed by two legs joined with a resilient hinge. One leg terminates in a hook member which secures the other leg when the clip is closed. Each leg of the clip is provided with an indentation extending across its width near the distal end which secures the clip in the applier and allows the clip to rotate about its hinge during closure. The clip applier is a forceps-type instrument having channeled jaws especially adapted to receive and close the plastic clip.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. patent application Ser. No. 12/290,352 filed Oct. 30, 2008, which in turn claims priority of U.S. application Ser. No. 10/854,123 filed May 26, 2004, the disclosure of which is incorporated herein by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable
FIELD OF INVENTION
[0003] This invention relates to continuous digesters for wood chips in the papermaking industry.
BACKGROUND OF INVENTION
[0004] As commonly practiced in the prior art relating to papermaking, wood chips and alkali liquor (white liquor) are pumped into the top of a hydraulic cooking vessel (digester, approximately 180 feet high and approximately 23 feet in diameter) that is operated at high pressure (165 psig) and temperature (325 degrees F.). A chip cooking process proceeds over the time that it takes the saturated chip column to move down through the digester where the discharge rate of the chips to a blow line at the bottom of the digester is matched to the feed rate at the top so as to maintain a constant level and retention time of the chips in the digester.
[0005] In the cooking process (delignification of wood chips), approximately 50% of the organic chip mass is dissolved in the cooking liquor. At 1 to 3 locations above the lower section of the digester, liquor containing the dissolved solids is removed from the vessel by extracting liquor through sets of screens in the circumferential wall of the digester, the screens being aligned with the inner wall of the digester vessel. The screens are 3 to 4 feet in height. The wash screens are the lowest (often the only) set of screens in a continuous digester and are located 10 to 20 feet up from the bottom of the digester. The screen plates are made from stainless steel with multiple slots cut in them that are 0.12 to 0.35 inch wide by 3 to 4 inches long depending on the location in the digester. The liquor that is extracted can be sent to a chemical recovery system where the liquor solids are concentrated and the organic solids burned in a chemical recovery boiler. The chemicals (inorganic solids) are recovered in the bottom of the recovery boiler and re-used to produce white liquor for the cooking process.
[0006] Just prior to discharge from the digester bottom, the chip mass is washed and cooled by cold (120 to 150 degrees F.) filtrate which is generated externally of the digester (from black liquor for example) and introduced into the wash zone of the digester. As much as possible remaining organic/inorganic material dissolved in the cooking liquor is removed from the chip column by a displacement and diffusion wash in the bottom of the digester by extraction of high-dissolved-solids hot liquor through the wash screens. To displace the high-solids hot liquor and to cool the chip mass, cooled black liquor filtrate is added to the bottom of the digester at several locations in the wash zone.
[0007] In some instances, some of the liquor extracted and/or a combination of lower solids liquors (black liquor and/or white liquor) is added to a center pipe (downcomer) in the digester that discharges in the center of the chip column adjacent to a given set of screens. The liquor added to the center pipe at least partially displaces the liquor being pulled through the extraction screens at such given set of screens.
[0008] In summary, the purpose of the wash screens is to remove high solids filtrate from the chip column as it passes these screens by the efficient displacement and diffusion wash with cooler and cleaner liquor added to counter wash nozzles, to ring dilution nozzles and/or to the center of the chip mass via a downcomer that discharges adjacent to these screens. The efficiency of the wash is measured by the extent to which there is maintained optimum low temperature of the chip mass discharged from the digester with concomitant minimization of the cooling of the wash liquor added to the wash zone.
[0009] Because of the nature of the compaction of the chip column, it is difficult to predict and/or control the uniform flow of re-circulation flows or free liquor upflows or downflows through the chip mass in a large diameter continuous digester of the prior art. In the wash zone, there is a tendency for upflows to short circuit up the sides of the digester and for liquor contained in the chip mass to be carried down with the chip mass only to be displaced from the chip mass at the very bottom of the wash zone.
[0010] Temperature and alkali uniformity in the wash zone are impacted by flows at the bottom of the wash zone and in the wash zone of the digester. The temperature and alkali uniformity in the wash zone are key factors in achieving uniform cook (delignification) across the column. Uniform delignification reduces cellulose (pulp fiber) attack, helping to achieve overall maximum pulp fiber strength and yield. Cook non-uniformity across the column profile, with accompanying non-uniform retention of lignin on the individual fibers is a common deficiency of known prior art digesters.
[0011] As noted, in the prior art, The liquor added to the bottom of the chip mass passes through the chip column via paths of least resistance to the wash screens. The wash screens accommodate this process anomaly by removing the most easily removable flow to support the total wash screens flow. This results in poor displacement and diffusion of dissolved solids (poor wash efficiency) in the chip mass to the wash screens and poor heat transfer in some portions of the chip column. The poor wash efficiency causes downstream problems in the brown stock treatment and bleaching processes. The poor heat transfer in the chip column at the bottom of the digester increases the energy costs in these two affected process areas. Also, during operation, individual wash screens tend to plug off completely with the other screens picking up the flow. Continuous digesters are only shut down for maintenance on an annual basis, due to cost of such shutdowns. In some cases it has been observed that one or two wash screens will plug and remain plugged for the remainder of the year only to be unplugged during the annual shut down. The chip column adjacent to plugged wash screens leads to poor wash efficiency and poor heat transfer.
[0012] Thus, the prior art is deficient in that:
1. The flow through each of the wash screens is variable and dependent on the path of least resistance flow of wash filtrate added to the bottom of the digester. This is observed physically by the wide variance in wash screen exit nozzle temperatures. 2. There is no known current method to control the individual wash screen flow and temperature in order to break up the pattern of path of least resistance flow of cold blow wash filtrate. Further, there is currently no known method to unplug the wash screens other than when the digester is empty during the annual shut down. 3. The upflow through the wash zone is operated at higher than optimum for alkali and temperature profile uniformity because of the current inability to manage and maintain an acceptable wash efficiency in the bottom of the digester. 4. There is no known current method for adjusting the amount of free liquor upflow through the wash zone in order to maintain uniformity of temperature and alkali in the wash zone where the highest percentage of the cook (time at temperature) is completed with the highest potential for product non-uniformity to be affected. Currently, in the prior art, a higher free liquor upflow is maintained in order to compensate for the non-uniformity of the operation of the wash screens. Whereas this higher free liquor upflow helps to manage the dissolved solids level in the digester discharge, such flow has a negative impact on the temperature and alkali profiles in the wash zone.
SUMMARY OF INVENTION
[0017] In accordance with one aspect of the present invention, the total volume of liquor withdrawn from the digester through the wash screens within the wash zone of the digester is uniformly and automatically distributed between all of the wash screens. To this end, in accordance with the present invention there are installed individual temperature measurement, flow measurement and flow control valves in association with each of the wash screen to control the flow through such wash screen to maximize energy and wash efficiency. Further, this feature provides for sensing of a screen in difficulty and individual isolation of a screen by closing it's flow control valve to allow the down flowing chip column to wipe a screen thereby cleaning and avoiding total plugging of the screen as occurs in the prior art.
[0018] Additionally, in the present invention, there is provided a central downcomer within the digester. This downcomer includes side discharge ports adjacent to the bottom end of the downcomer through which filtrate liquor is discharged into the digester. These discharge ports of the downcomer are disposed substantially radially of the surrounding wash screens such that the discharge streams of filtrate liquor from the ports are directed substantially radially toward the surrounding screens, thereby creating a layer of filtrate liquor flowing perpendicularly from the center of the digester toward all the screens. This flow pattern of liquor filtrate is directed across the downward flow of the chip mass and has been found to break up or discourage formation of upflow/downflow streams of filtrate liquor within the area of the screens.
[0019] As desired, the piping associated with the wash screens may be provided with automatic or manual back flush apparatus to allow reverse flow of filtrate through the screens to assist in clearing a screen that is showing signs of plugging.
[0020] Still further, in accordance with one aspect of the present invention the present inventors have found that reducing the wash zone free liquor upflow ((for example, from about the current 0.25 gpm/ADt/d (US gallons per minute per air dry tonne per day to a 0.007 gpm/ADt/d of free liquor upflow or downflow)), provides improved uniformity of the product leaving the wash zone.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The foregoing, as well as other objects and advantages of the invention will become apparent from the following detailed description when taken in conjunction with the accompanying drawings, wherein like reference characters designate like parts throughout the several views, and wherein:
[0022] FIG. 1 is a schematic representation of a typical wood chip digester embodying various of the features of the present invention;
[0023] FIG. 2 is a schematic representation of a portion of the digester depicted in FIG. 1 and taken along the circle 2 of FIG. 1 ;
[0024] FIG. 3 is a schematic representation of various piping elements and flow directions of fluids into the digester from a downcomer and out of the digester via control elements associated with the present invention; and
[0025] FIG. 4 is detailed side view of the distal end of a downcomer as depicted in FIG. 1 .
DETAILED DESCRIPTION OF INVENTION
[0026] In the embodiment of the present invention depicted in FIGS. 1 and 2 , as noted hereinabove, approximately 50% of the organic chip mass 10 is dissolved in the looking liquor. The depicted digester 14 includes an upper zone 13 into which the chip mass is loaded. This is also the cooking zone. A set 16 of screens, twelve screens 18 in a typical embodiment, are disposed about the inner circumferential wall 20 of the digester at a location just below the cooking zone 13 and above a wash zone 24 which is disposed at the bottom end of the digester.
[0027] Liquor containing dissolved solids is extracted from the interior of the digester through the screens. The liquor extracted through the individual screens is conveyed to a discharge header 28 which encircles the girth of the digester externally of the digester in the region of the screens and is conveyed, as by a pump system 30 , to a chemical recovery station 32 or is selectively returned in part to the digester via a downcomer 54 . As desired, a heater may be interposed within the piping between the pump station and the downcomer to heat the filtrate prior to its return to the digester. The downcomer is located centrally of the digester and includes discharge ports 38 adjacent the lowermost end of the downcomer. As depicted in FIG. 1 , these ports are disposed substantially radially equidistant from the surrounding screens such that the filtrate liquor discharged through the ports is directed substantially radially outwardly (see arrows of FIG. 1 ) from the downcomer ports thereby ensuring that the filtrate liquor discharged from the downcomer flows simultaneously and substantially uniformly radially toward all of the screens. When the filtrate liquor discharged into the chip mass adjacent the wash screens is heated to about the cook filtrate liquor temperature, and by reason of the radially lateral flow of the discharge filtrate liquor, upflow or downflow of the liquor through the chip mass in the area of the screens is prevented or discouraged.
[0028] As needed or desired, black liquor from one or more known sources in a papermaking facility may be added to the filtrate liquor which is extracted from the screens and fed to the downcomer.
[0029] In the depicted digester, there is provided a single set 16 of wash screens includes multiple separate screens 18 covering the digester circumference. As noted, these screens serve to permit the withdrawal of hot liquor containing dissolved organic/inorganic solids from the digester for reuse or recovery of the individual components of the extracted filtrate. In accordance with one aspect of the present invention, and referring to FIGS. 1 and 2 , conveyance of extracted filtrate from each screen 18 is effected by means of a stub pipe 26 disposed behind each screen 18 and serves to accept the liquor extracted from the digester by the screen and to convey the same away from the screen. This stub pipe is in fluid flow communication with a discharge ring header 28 which encircles the digester outside of and along the outer wall 42 of the digester and which serves to convey the filtrate from the several screens to a pump station.
[0030] With specific reference to FIGS. 2 and 3 , in accordance with the present invention, a continuous digester 14 having a set 16 of screens 18 disposed about its inner circumference 20 for withdrawal from the digester through the screen solids-bearing hot liquor, is provided with a combination of elements associated with the stub pipe 26 which is in fluid communication between each screen and a generally circular discharge collection header 28 disposed externally about the outer circumference of the digester. In the depicted embodiment of the invention, these elements are interposed along the length of the stub pipe and between the outer wall of the digester and the header. Each such combination of elements includes a first manual valve 50 located adjacent the digester outer wall, a temperature sensor 52 next to the first manual valve, an electronically controlled valve 54 next to the temperature sensor, a flowmeter 56 next to the electronically controlled valve, and a second manually operated valve 58 adjacent the header. As seen in FIG. 1 , the header is in fluid communication with a pump 30 which functions to draw the hot liquor extracted by each screen through the header to remote locations such as a chemical recovery station 32 , etc.
[0031] FIG. 3 schematically depicts the combination of elements referenced above and shows the association of a combination of elements associated with each individual screen. In this FIG. 3 , the valves associated with back wash of each screen, as seen in FIG. 2 , have been omitted for purposes of clarity.
[0032] In the present invention, hot liquor extracted from the digester through a given screen flows through the combination of elements which are interposed between the digester and the header. In the depicted embodiment, the discharge flow of hot liquor initially encounters the first manual valve 50 . This valve is manually operable to provide a means for manually adjusting the outflow from a given screen to either full flow, partial flow, or no flow. Next in line, the discharge flow encounters the temperature sensor 52 which includes an electrical lead 60 that passes to a controller 62 . Next in line, the discharge flow encounters the electronically controlled valve 54 having an electrical lead 64 that passes to the controller. Next in line, the discharge flow encounters the flowmeter 56 which also includes an electrical lead 66 which passes to the controller. Finally in line, the discharge flow encounters the second manually operated valve 58 and then flows into the header 28 . In the depicted embodiment there is provided a conduit 68 which intersects the stub pipe at a location between the flowmeter and the second manual valve. This conduit is provided with a third manually operated valve 70 .
[0033] Operationally, the first manually operated valve 50 functions to allow manual control over the flow through the stub pipe (irrespective of direction of flow) as either full flow, partial flow or no flow. Thus, this first valve functions as a type of override to any automatic control over the flow between the digester and the header, and in a backwash situation to assist in the flow control of backwash liquid to a screen. For back washing of a screen, the automatic control of the flow of discharge liquor from the screen toward the header is deactivated (as by the controller), the second manual valve 58 is closed to close off all flow to the header, and the third valve 70 is opened to admit backwash liquid into the stub pipe, thence to the screen at a flow rate which can be selected by either or both of the first and third manual valves.
[0034] During normal operation of the digester, with the second and third manual valves closed, and the first manual valve open, the outflow of hot liquor through each of the screens of the set of screens is selected automatically via the controller. Specifically, as hot liquor is withdrawn through a given screen, under the influence of the pump 30 , this discharge liquor encounters the temperature sensor 52 which senses the temperature of the discharge flow and develops an electrical signal which is representative of such flow and transmits such signal to the controller. Like signals representative of the temperature of the discharge flow from each of the screens are fed into the controller where these temperatures are compared to one another and to a temperature which is representative of the desired flow from each screen and which serves as a standard against which each of the discharge flows of each of the screens is compared. Variations in the temperature of the discharge flow from a given screen from the standard temperature are indicative, first, of the existence of flow from the screen, and, second, of the possible existence of cool upflow liquor from the wash zone reaching the screen without passing through the chip mass as a disbursed stream.
[0035] After the discharge flow passes the temperature sensor, it encounters the electronically controlled valve 54 which functions to adjust the rate of discharge flow to a value which is determined by the controller.
[0036] Downstream of the electronically controlled valve, the discharge flow encounters the flowmeter whose function is to sense the rate of flow of the discharge liquor through the stub pipe, generate an electrical signal representative of the sensed rate of flow and transmit such signal to the controller via the electrical lead 66 .
[0037] From the foregoing, it will be evident that if a screen is fully plugged, all flow of hot liquor through the screen will be halted. In this event, the there is no flowing hot liquor to contribute to the temperature sensed by the temperature sensor so this sensor will report to the controller a relatively cool temperature. Within the controller this cooler temperature will be compared to the normal hot liquor temperature, or other set temperature, and generate a signal to the operator to alert the operator to this undesirable condition. Likewise, the flowmeter will signal the controller that there is no flow through the stub pipe, this condition also possibly being the result of a plugged screen. In the present system, to avoid actual full plugging of a screen, the controller may be set to alert the operator when there is only a small drop in the temperature of hot liquor and/or small drop in the flow rate of the hot liquor passing through the stub pipe so that the operator may take remedial action immediately to remedy the plugging of the screen. This combination of a reduction in the anticipated flow rate through a stub pipe as sensed by the flowmeter which also sends to the controller a signal representative of such reduced flow to the controller, with the sensed reduction in temperature of the flowing hot liquor provides a novel improved concept for monitoring the operability of each individual screen. Thus, the signal from the flowmeter provides the controller with a signal, which compliments the signal to the controller from the temperature sensor.
[0038] In like manner, if the temperature within the stub pipe is within a range recognized by the controller as acceptable, but the flow rate of hot liquor through a given stub pipe increases above a standard value set in the controller, such conditions may indicate that more than anticipated hot liquor is flowing through the given stub pipe. This condition can be indicative of the lack of contribution to the overall desired discharge rate of hot liquor from the digester by one or more of the other screens, for example, and an alert to the operator to at least investigate the digester operating conditions and, if needed, take remedial action. Thus, it is seen that the combination of the temperature sensor and the flow meter are essential to the successful functioning of the present invention.
[0039] Further, if the rate of flow of hot liquor through the stub pipe is within a range set in the controller, but the temperature of the flow of hot liquor is lower than anticipated, such condition may be indicative of relative cool wash liquor moving upwardly of the digester into the area of the screens, such flow of cool wash water being possibly due to too much wash water being added to the bottom end of the digester or the existence of excess upflow of the wash liquor to a given screen or screens.
[0040] Other combinations of sensed temperature and independently sensed flow rate may be indicative of other operating conditions within the digester which may call for operator interdiction. For example, since the flow of hot liquor from each screen is monitored, both for temperature and flow rate, independently of every other screen, it may be readily determined if one or more screens is not functioning as desired, and importantly, which one or more screens is involved, thereby localizing a malfunction within the digester.
[0041] The present invention provides prompt and early indication of a source of possible trouble with respect to the outflow of hot liquor from the digester. In this respect, if a given screen or screens is noted to be plugging, the operator can close down outflow from such screen or screens, thereby allowing the downflowing chip stream to sweep the surface of the screen interiorly of the digester and remove all or part of any material which is attempting to plug the screen or screens. If this technique is unsuccessful, the operator further has the option of back washing the screen or screens individually employing the first, second and third manually operable valve which are associated with the stub pipe of each screen.
[0042] In accordance with one aspect of the present invention, hot liquor withdrawn from the digester through the screens and after being subjected to chemical recovery, is reintroduced to the interior of the digester through the downcomer which is aligned with the vertical centerline 74 . In the present invention, contrary to the prior art, the discharge ports in the bottom end of the downcomer are disposed both centrally of the interior of the digester and radially aligned with the screens which surround the downcomer. In this manner, the present inventors provide for the injection into the chip mass of a substantially circular sheet of fresh hot liquor which flows from the downcomer ports radially toward the screens. This flowing sheet of hot liquor has been found to eliminate or substantially discourage the development of upflows or downflows within the chip mass at substantially all points radially between the downcomer and the screens in the digester wall. This effect has been particularly noted in the regions of the perpendicular cross-section of the digester at the level of the screens and adjacent the screens for reasons not fully understood.
[0043] In addition to the recycling of treated hot liquor which has been withdrawn from the digester via the discharge header and fed back into the digester via the downcomer, cold filtrate (below the cooking temperature of the chip mass in the digester) from black liquor sources common in a papermaking facility, may be introduced into the bottom end of the digester as wash liquor as by a pump and associated piping as is known in the art. As desired or needed, such black liquor may be added to the digester through the downcomer, either as a substitute for hot liquor from the chemical recovery station or as an additive to the hot liquor from the recovery station.
[0044] Control over the flow of black liquor into the digester may be controlled through the controller, and a plurality of electrically operable valves, such as valves 73 , 76 and 78 . Each of these, and all others of the electrically operable valves includes a respective electrical lead between the controller and each such valve. In the Figures, the electrical leads from these and others of the electrically responsive elements are indicated in dashed lines for purposes of clarity, but in all instances these electrical leads extend between the respective valve or element and the controller.
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A continuous digester comprises a wash zone having a plurality of individual wash screens disposed about an inner wall of the digester for the withdrawal of co-current downflow liquor from the wash zone. A conduit is connected in fluid communication between each of the wash screens and a collector for co-current downflow liquor withdrawn from the wash zone of the digester. A valve is interposed along the length of the conduit leading from each of the wash screens. The valve is operable between open and closed positions in response to a signal received from a temperature sensor associated with the conduit leading from each of the wash screens. The signal represent changes in temperature of a corresponding co-current down flow liquor through a corresponding conduit wherein a corresponding valve permits adjustment of a corresponding flow rate of liquor through said corresponding conduit to a flow rate that is substantially equal to each of the other flow rates of co-current downflow liquor through each of the other conduits.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention is directed to an electric thin-film circuit in which various thin films form the circuit and the components are formed from these thin films by selective etching.
2. Prior Art
The U.S. patent application Ser. No. 408,100 of Oct. 19, 1973 explains in detail that tantalum-aluminum alloys are well suited for electric thin-film circuits disposed upon a substrate made of an insulator material, and that particularly favorable electric values are obtained in view of temperature coefficients and the time constancy, when the tantalum content is relatively low, compared with the aluminum content, for instance in the range between 2 and 20 atomic percent.
It was stressed in this application that the aluminum forms a so-called face-centered cubic lattice (fcc lattice), in the case of a tantalum content of approximately 7 atomic percent or less, instead of forming a tetragonal lattice as this is the case with a higher tantalum content. This fcc lattice entails a great time stability of the finished electric components which were produced in accordance with this tantalum-aluminum thin-film technique.
The present invention proceeds from this suggestion and provides a thin-film circuit utilizing tantalum-aluminum layers of different tantalum contents and comprising a capacitor and at least one conductor path and/or at least one resistor, whereby the tantalum-aluminum oxide layer forming the capacitor dielectric is produced as independently as possible from the conductor path or the resistor path, in order to minimize production tolerances.
SUMMARY OF THE INVENTION
It has been found desirable to provide an electric thin-film circuit of the initially mentioned kind whereby the basic electrode, at least in the area of a capacitor, consists of two layers of tantalum-aluminum alloys with differing tantalum contents, whereby the layer with the higher tantalum content is placed directly onto the substrate, and the other one thereupon. The layer with the lower tantalum content oxidizes to form the capacitor dielectric, and this oxidation layer is provided with the opposite capacitor electrode, consisting preferably of a nickel-chromium-gold layer. This material may also be used for the conductor paths, whereby it is placed upon the layer with the higher tantalum content. It is also advantageous when the resistors are formed of the layer with the higher tantalum content.
In accordance with a preferred method for the production of such thin-film circuits, the substrate is first provided with the tantalum-aluminum-alloy having the higher tantalum content, for instance between 30 and 70 atomic percent, in particular approximately 50 atomic percent. The second tantalum-aluminum layer having the lower tantalum content, for instance between 2 and 20 atomic percent is applied onto the first layer, for instance by a way of cathode sputtering. Then, prior-art masking and etching techniques are used to interrupt both layers in places where capacitors are to be formed. After the removal of the first etching mask, a tantalum-aluminum-oxide layer is produced by way of an anodic oxidation. The portions of this tantalum-aluminum-oxide layer, which are to be used for the capacitor formation, are then covered by a further mask. The remaining portions are first freed from the tantalum-aluminum oxide and then from the layer having the lower tantalum content. After the residual mask portions have been removed, a good conductor is applied as a surface layer, for instance a nickel-chromium-gold layer. This layer serves as capacitor electrode and possibly as conductor paths. If resistors are present, they are produced from the tantalum-aluminum layer with the higher tantalum content.
It is recommended to carry out the anodic oxidation of the tantalum-aluminum layer while using a weak acid such as a diluted citric-acid solution. The process is preferably continued by using a current density in the order between 0.1 and 1.0 mA/cm 2 until a forming potential in the order of several hundred volts is obtained, in particular in the area around 500 volts. An electrolyte containing hydroflouric acid, for instance a diluted solution of hydroflouric acid and nitric acid, are suited for etching the tantalum-aluminum-oxide layer. A diluted cerium-sulfate solution or a diluted hydrochloric-acid solution or a diluted caustic-soda solution are suited for etching the tantalum-aluminum layer with the lower tantalum content. A diluted solution containing hydrofluoric acid and nitric acid is recommended for etching the tantalum-aluminum layer with the higher tantalum content. The above etching agents will operate at room temperature.
BRIEF DESCRIPTION OF THE DRAWING
In the drawings, which are not drawn to size, like reference characters indicate like or corresponding parts:
FIG. 1 is a diagram of a circuit produced in accordance with this invention,
FIG. 2 is a partial cross-sectional view of the circuit after the application of the two tantalum-aluminum layers,
FIG. 3 is a partial cross-sectional view of the arrangement in FIG. 2, after the application and exposure of the photo mask,
FIG. 4 is a partial cross-sectional view of the arrangement of FIG. 3, after the etching process, and the removal of the photo mask,
FIG. 5 is a perspective view of the arrangement of FIG. 4,
FIG. 6 is a partial cross-sectional view of the arrangement of FIG. 4, after the oxidation process.
FIG. 7 is a partial cross-sectional view of the arrangement after the application of a second photo mask defining the capacitor shape,
FIG. 8 is a partial cross-sectional view of the parts of the arrangement of FIG. 7 which remain after the etching process, of the tantalum-aluminum-oxide layer,
FIG. 9 is a partial cross-sectional view of the arrangement after the etching process of the second tantalum-aluminum layer has been carried out and the photo mask has been removed.
FIG. 10 is a partial cross-sectional view of the arrangement after the application of the conductive layer,
FIG. 11 is a partial cross-sectional view of the arrangement after a further etching process has been carried out to form the conductors or resistors, and
FIG. 12 is a perspective view of the finished circuit shown in FIG. 1.
DESCRIPTION OF PREFERRED EMBODIMENTS
The figures of this application explain a preferred embodiment of a circuit in accordance with the invention. Thereby, the longitudinal branch of a four terminal arrangement comprises a capacitor C. A resistor R2 may be arranged in series therewith, while a further resistor R1 is placed in the cross branch. The following figures explain a preferred method of production of the circuit in accordance with FIG. 1.
FIG. 2 shows a substrate 1 made of an insulating material such as glass, quartz, sapphire or polished fine-grain ceramic which is first provided with a tantalum-aluminum-alloy layer 2 having a tantalum content between 30 and 70 atomic percent, preferably approximately 50 atomic percent. This layer is applied in a prior-art manner, for instance by cathode sputtering. A further tantalum-aluminum-alloy layer 3 is applied onto the previous one 2, but this layer 3 has a relatively lower tantalum content in the order between 2 and 20 atomic percent.
The above substrate is now covered by a photo mask 4 which is exposed and developed to leave an opening for the later capacitor formation, for instance at the point 5. Thus, the tantalum-aluminum layer 3 is exposed at this point 5, as shown in FIG. 3. During an etching process, both tantalum-aluminum layers 2 and 3 are removed in the area of the opening 5, forming the opening 6 exposing the substrate 1, as shown in FIGS. 4 and 5. In these figures, the photo mask 4 had been previously removed.
FIG. 6 shows a layer 7 of tantalum-aluminum oxide formed by an anodic oxidation of the surface of layer 3 and of the frontal surfaces of both tantalum-aluminum layers 2 and 3.
In the above arrangement, the tantalum-aluminum layer 2 has an approximate thickness of a few tenths of a micrometer, the tantalum-aluminum layer 3 has a thickness of approximately 1 micrometer, and the substrate 1 is approximately 0.6 mm thick. The tantalum-aluminum-oxide layer 7, which is shown in FIG. 6, is produced by an anodic oxidation carried out with a constant current source. It is made so thick that a potential difference in the order of several 100 volts, preferably up to 500 volts, is produced between the free side of the layer 7 and the tantalum-aluminum layers 2 and 3 upon substrate 1, if 0.1 through 1 mA/cm 2 are applied. It is not advisable to exceed the above voltage since breakthroughs through the tantalum-aluminum-oxide layer cannot always be avoided at the present time. However, this value does result in a relatively high voltage strength, as compared with the capacitor dielectrics formed of prior-art tantalum-aluminum-oxide layers.
Next, the substrate 1 and the layers 2, 3, as well as the tantalum-aluminum-oxide layer 7 are cleaned and provided with a further photo mask 8, as shown in FIG. 7. This photo mask 8 fixes the area where the tantalum-aluminum oxide is to be retained to form the capacitor dielectric. The application of this photo mask 8 is well known in the art. In the following etching process, the tantalum-aluminum-oxide which is not covered by the mask 8 is removed, so that only the tantalum-aluminum-oxide area 7' shown in FIG. 8 will remain to form the dielectric. The etching mask 8 is also used in the next etching process, whereby the three areas of the tantalum-aluminum layer 3 with the relatively lower tantalum content are removed. Hereby, the layer 2 is not attacked because the layer 3 can be etched five through 20 times faster than the layer 2, due to the differing tantalum content. It is thus possible to obtain the shape shown in FIG. 9 with high precision. After the removal of the photo mask 8, the areas 2 and 2' of the tantalum-aluminum alloy with the higher aluminum content will remain.
It is shown in FIG. 9, the tantalum-aluminum layer 2' in the area of the capacitor will now be covered by the residual portion 3' of the tantalum-aluminum alloy with the lower tantalum content, and the frontal ends of both tantalum-oxide layers 2' and 3' as well as the upper portions of the layer 3' are still covered by the tantalum-aluminum-oxide film 7' which has a thickness in the order of a some tenths of a micrometer and serves as a capacitor dielectric.
The remaining production of the capacitor is in accordance with the prior art. The parts of the cleaned substrate which support one or several of layers 2, 2', 3' and 7' are now covered with a nickel-chromium-gold layer, for instance by successively evaporating a nickel-chromium layer 9 and a gold layer 10. The thickness of this combined nickel-chromium-gold layer 9, 10 is usually in the order of a few tenths of a micrometer. Such an embodiment is shown in FIG. 10. A further photo mask is used to cover the portion 11 of the nickel-chromium-gold layer 9, 10, which is required to form the conductor paths and the opposite electrode of the capacitor. The remaining portions of the nickel-chromium-gold layer 9, 10 are etched away in a prior-art manner, for instance with the help of a solution containing potassium-iodide and iodine solution for the gold and a diluted cerium-sulfate solution for the nickel-chromium portion. Then, prior art masking and etching techniques are used to produce the resistor R1. This resistor R1 is formed by layer 2 and it may be shaped as shown in FIG. 12.
If an additional resistor R2 is to be introduced (as indicated by interrupted lines in FIG. 1) in series with the capacitor, as shown in FIG. 11, this may be done by etching away more of the nickel-chromium-gold layer upon the tantalum-aluminum layer 2'. In this case, the portions 9, 10 and 9', 10' will remain which bridge the highly resistive tantalum-aluminum alloy whereby the layer 2' may be made to have a different shape to obtain different resistance values, for instance in the shape of a meander.
FIG. 12 shows the circuit designed in FIG. 1 in a perspective view, whereby the portions 10, 10' correspond to the like numbered portions of FIG. 11. In addition to the features of FIG. 11, the continuous conductor path 12 and the resistor path R1 are shown, whereby the resistor path R1 merges directly into the layers 2 of section 9, 10 and 12. The resistor layer of R1 and R2 consists of the tantalum-aluminum alloy with the relatively high tantalum content. The nickel-chromium gold layers supplement the tantalum-aluminum layer with the higher tantalum content to form conductor sections 9, 10 and 12 which have a high conductivity.
In accordance with another embodiment of this invention, it is possible to produce the conductor structure and the resistor structure directly from the substrate 1 with the two tantalum-aluminum-alloy layers 2 and 3, as shown in FIG. 5, whereby corresponding masks and etching process are applied. In this case, the capacitor is only formed in the area around location 6, while using further masks, and the anodic oxidation process which was explained with the help of FIGS. 6 through 11.
It will be apparent from the above description of the preferred embodiments that this invention provides a simple, practical and effective thin-film circuit and a method for its production. Although there may be variations and modifications made by those skilled in the art, it is desired to include them within the scope of the invention as defined in the appended claims.
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An electric thin-film circuit has a conductor path and at least one capacitor and/or one resistor, and it comprises a substrate base member with a first tantalum-aluminum-alloy layer formed thereupon, and is etched to form the outline of the conductor path. A second tantalum-aluminum-alloy layer with a tantalum content of approximately 2 through 20 atomic percent is disposed thereupon, at least in the area of a capacitor, and an oxidation layer is formed upon this second tantalum-aluminum-alloy layer to constitute the capacitor dielectric. The conductor paths and the opposite capacitor electrode are formed of a conductive layer such as a nickel-chromium-gold layer.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a sewing machine for automatically forming a plurality of stitch patterns selected from among a large number of predetermined juxtaposed patterns.
2. Description of Related Art
A sewing machine with which a plurality of stitch patterns selected from among a large number of predetermined patterns are juxtaposed is disclosed in Japanese Patent Laid-Open Publication No. 60-60890. The sewing machine includes a display device. The display device displays thereon a total length of the selected patterns, that is, a total length of a combination pattern, in a direction in which the patterns are juxtaposed. Such a direction will be hereinafter referred to as pattern arrangement direction. According to the sewing machine, an operator can confirm, before starting sewing, a total length of a combination pattern consisting of a plurality of selected patterns. Therefore, the operator can avoid forming a combination pattern that, when sewn, extends beyond a predetermined sewing area.
While the sewing machine can display a total length of a combination pattern in its pattern arrangement direction, it cannot display a total length of a combination pattern in a direction perpendicular to its pattern arrangement direction. Such a perpendicular direction will be hereinafter referred to as pattern widthwise direction. In particular, in the sewing machine, no attention is paid to the protrusion of a combination pattern from the predetermined sewing area in a pattern widthwise direction. The operator cannot confirm the total length of a combination pattern in a pattern widthwise direction before starting sewing. Therefore, the sewing machine has a problem that a combination pattern may be formed that extends beyond the predetermined sewing area on a fabric or a combination pattern may be formed in a partially overlapping relationship in a pattern widthwise direction with another pattern previously formed on the fabric.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a sewing machine wherein a combination pattern can be prevented from being formed beyond a predetermined sewing area on a fabric in a pattern widthwise direction.
In order to attain the object, according to the invention, there is provided a sewing machine capable of forming a plurality of stitch patterns, which comprises: size data storage means for storing therein size data related to sizes of a plurality of predetermined patterns; pattern selecting means for selecting a desired pattern from among the plurality of predetermined patterns; combination designating means for successively combining patterns selected by the pattern selecting means; stitch forming means for forming a plurality of patterns combined by the combination designating means to be juxtaposed in a pattern arrangement direction to form a combination pattern; pattern width calculating means for calculating a total length of a combination pattern to be formed by the stitch forming means in a pattern widthwise direction perpendicular to the pattern arrangement direction based on the size data stored in the size data storage means to determine a width of the combination pattern; and display means for displaying a width of the combination pattern calculated by the pattern width calculating means.
In the sewing machine of the present invention, the size data storage means stores therein size data related to sizes of a plurality of predetermined patterns. The pattern selecting means selects a desired pattern from among the plurality of predetermined patterns. The combination designating means successively combines patterns selected by the pattern selecting means. The stitch forming means forms the patterns combined by the combination designating means to be juxtaposed in a pattern arrangement direction to form a combination pattern. The pattern width calculating means calculates, based on the size data stored in the size data storage means, a total length of a combination pattern to be formed by the stitch forming means in a pattern widthwise direction perpendicular to the pattern arrangement direction to determine a width of the combination pattern. The display means displays the width of the combination pattern calculated by the pattern width calculating means.
According to the sewing machine of the present invention, a total length of a combination pattern in its pattern widthwise direction, i.e., a width of the combination pattern is displayed on the display means. Accordingly, an operator can confirm the width of the combination pattern before starting sewing. Therefore, a combination pattern selected can avoid protruding from a predetermined sewing area on a fabric in a pattern widthwise direction.
BRIEF DESCRIPTION OF THE DRAWINGS
A preferred embodiment of the present invention will be described in detail with reference to the following figures, wherein:
FIG. 1 is a perspective view showing a sewing machine to which a first embodiment of the invention is applied;
FIG. 2 is a block diagram showing the electrical structure of the sewing machine;
FIG. 3 is a flow chart illustrating operation of a CPU (central processing unit) of the sewing machine;
FIG. 4 is a table illustrating stored contents of a ROM (read only memory) of the sewing machine;
FIG. 5 is a table illustrating stored contents of a RAM (random access memory) of the sewing machine;
FIG. 6 is an illustration showing a pattern formed by the sewing machine;
FIG. 7 is an illustration showing a displaying condition of an LCD (liquid crystal display) of the sewing machine;
FIG. 8 is a similar view but showing another displaying condition of the LCD of the sewing machine;
FIG. 9 is a flow chart illustrating part of the operation of a CPU of a sewing machine to which a second embodiment of the invention is applied;
FIG. 10 is a table illustrating stored contents of a ROM of the second sewing machine;
FIG. 11 is a table illustrating stored contents of a RAM of the second sewing machine;
FIG. 12 is an illustration showing a pattern formed by the second sewing machine;
FIG. 13 is an illustration showing a displaying condition of an LCD of the second sewing machine; and
FIG. 14 is a similar view but showing another displaying condition of the LCD of the second sewing machine.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A first embodiment of the present invention will be described with reference to FIGS. 1 to 8. As shown in FIG. 1, a column portion 12 is provided uprightly on a bed portion 11 of a sewing machine 10. One end of an arm portion 14 is supported horizontally at the end of the column portion 12. A head portion 16 is formed at the other end portion of the arm portion 14. A needle bar 20 having a sewing needle 18 attached thereto is supported for upward and downward movement and also for rocking motion on the head portion 16. The needle bar 20 is driven to reciprocate in the upward and downward directions and the leftward and rightward directions in synchronization with rotation of a main shaft, not shown, provided in the arm portion 14. A presser foot 22 is supported for upward and downward movement on the head portion 16. The presser foot 22 can be moved between its lifted position and lowered position manually. A feed dog 24 is provided adjacent the location of the sewing needle 18, on the bed portion 11, and is driven to reciprocate in synchronization with the rotation of the sewing machine main shaft to feed a work fabric forwardly or rearwardly and/or leftwardly or rightwardly. A sewing machine motor, not shown, for rotating the main shaft is provided in the bed portion 11.
A pattern display section 26 is provided on the face of the arm portion 14. A large number of patterns belonging to three groups A, B and C are displayed on the pattern display section 26, the patterns having sizes smaller than those of the stitch patterns actually formed on a work fabric, together with two digit pattern identification numbers (not shown). Patterns belonging to group B include continuous stitch patterns including practical stitches, such as a straight stitch and a zigzag pattern stitch, and ornamental patterns. Patterns belonging to the group A include characters, numeric figures, and symbols. Patterns belonging to group C include common series of patterns or series of characters, numeric figures, and symbols. Accordingly, patterns belonging to groups A or C are cyclic patterns, each of which is sewn separately. However, the subject matter of the groups, as described herein, is for purposes of explanation. Other groupings could just as easily be employed.
A total of ten pattern selecting switches 28 for selecting a desired pattern are disposed below the pattern display section 26. A number is embossed on each of the ten pattern selecting switches 28. An LCD 30 is provided on the right-hand side of the pattern display section 26. The LCD 30 displays the name or shape of a pattern, the dimension of the pattern in a forward and rearward feeding direction (pattern arrangement direction) of a work fabric, and actual dimensions of the pattern in a needle rocking direction and a work fabric leftward and rightward feeding direction (pattern widthwise direction). A combination designating switch 34 is disposed on the right-hand side of the pattern selecting switches 28 and a start/stop switch 38 for starting or stopping the sewing machine 10 is provided at a lower end portion of the head portion 16. A speed setting device 40 for setting the speed of the sewing machine motor to a predetermined value is provided at a lower end portion of the column portion 12.
The electrical structure of the sewing machine 10 described above will be described with reference to FIG. 2. A pattern selecting device 44 includes the pattern selecting switches 28. When a pattern selecting switch 28 is operated by an operator, the pattern selecting device 44 supplies a pattern code to a CPU 46 corresponding to the selected switch. A combination designating device 48 is constructed to include the combination designating switch 34. When the combination designating switch 34 is operated by an operator, the combination designating device 48 supplies a combination designating signal to the CPU 46.
The CPU 46, when power is supplied to the sewing machine 10, operates as shown in the flow chart of FIG. 3. A ROM 50 has stored therein the programs for operating the CPU 46, stitch data for forming various patterns and display data for allowing the shapes of the patterns to be displayed. The ROM 50 further stores therein such uppermost position data and lowermost position data representative of sizes of various patterns in a pattern widthwise direction and pattern length data representative of sizes of the patterns in a pattern arrangement direction as seen in the table shown in FIG. 4.
The RAM 52 stores pattern codes corresponding to selected patterns in an order in which they are to be combined. The RAM 52 further stores temporarily therein uppermost and lowermost position data and pattern length data of the patterns in the order in which they are to be combined as shown in the table shown in FIG. 5. It is to be noted that, in FIGS. 4 and 5, data are represented not in the form of actually stored data but in the form of actual patterns and sizes for convenience. Description will be given subsequently of a manner in which uppermost position data and lowermost position data are determined. In particular, a distance in the rightward direction from a reference line extending in the forward and rearward direction and indicated by an alternate long and two short dashes line in FIG. 6 is determined as uppermost position data. Meanwhile, a distance in the leftward direction from the reference line is determined as lowermost position data.
A stitch forming apparatus 54 includes the sewing needle 18 and the feed dog 24. The stitch forming apparatus 54 drives the sewing needle 18 and the feed dog 24 in accordance with a signal supplied thereto from the CPU 46. It is to be noted that the detailed construction of an apparatus for causing rocking motion of the sewing needle 18 and another apparatus for causing forward and backward motion and leftward and rightward motion of the feed dog 24 are similar to those of an apparatus disclosed in U.S. Pat. No. 5,063,867, issued Nov. 12, 1991 accordingly, detailed description thereof is omitted herein. The U.S. Pat. No. 5,063,867 is incorporated by reference. The LCD 30 displays, in accordance with a signal supplied from the CPU 46, the name or shape of a pattern, the dimensions of the pattern in a forward and rearward feeding direction (pattern arrangement direction) of a work fabric, and the dimensions of the pattern in a needle rocking direction and a work fabric leftward and rightward feeding direction (pattern widthwise direction).
Operation of the sewing machine 10 having such a construction as described above will be described with reference to the flow chart of FIG. 3. It is to be noted that the reading of the data from the ROM 50, the storing of the data into the RAM 52 and the outputting of the data to the stitch forming apparatus 54 upon pattern selection by the CPU 46 are similar to those of the apparatus disclosed in Japanese Patent Laid-Open Publication No. 60-60890, and accordingly, detailed description thereof will be omitted herein. Japanese Patent Laid-Open Publication No. 60-60890 is incorporated by reference.
After power is applied to the sewing machine 10, the CPU 46 executes an initializing operation at step SP1. The initializing operation also includes an operation of setting to 0001 an address value which designates an area of the RAM 52 into which pattern dimension data are to be stored.
Subsequently, if an operator operates the pattern selecting switches 28 to select, for example, a pattern "A" in order to form a combination pattern, such as shown in FIG. 6, a pattern code representative of the pattern "A" is supplied from the pattern selecting device 44 to the CPU 46. When the CPU 46 judges selection of the pattern at step SP2, at step SP3 the CPU 46 stores the pattern code corresponding to the pattern "A" into the RAM 52. The CPU 46 then reads, from the ROM 50, display data for allowing a shape of the pattern "A" to be displayed and outputs the display data to the LCD 30. The CPU 46 then reads, from the ROM 50, uppermost position data (1.5), lowermost position data (0) and pattern length data (1.2), shown in FIG. 4, corresponding to the pattern "A". Then, the CPU 46 stores the uppermost position data (1.5), lowermost position data (0) and pattern length data (1.2), corresponding to the pattern "A", into a storage area of the address value 0001 of the RAM 54 as seen in FIG. 5.
Subsequently, the CPU 46 selects, at step SP4, maximum values among the uppermost position data and lowermost position data stored in the storage areas of the address values of 0001 et seq. of the RAM 54. The CPU 46 adds the thus selected uppermost position data and lowermost position data to determine pattern height data and outputs the thus determined pattern height data to the LCD 30. In the case where only the pattern "A" is selected, only one uppermost position data and only one lowermost position data are stored in the storage areas of the address values of 0001 et seq. of the RAM 54, and accordingly, the CPU 46 adds the uppermost position data (1.5) and the lowermost position data (0) of the pattern "A" and outputs pattern height data (1.5) obtained by such addition.
At step SP5, the CPU 46 adds all of pattern length data stored in the storage areas of the address values of 0001 et seq. of the RAM 54 and outputs the sum to the LCD 30. In the case where only the pattern "A" is selected, only one pattern length data is stored in the storage areas of the address value of 0001 et seq. of the RAM 54 and, accordingly, the CPU 46 outputs the pattern length data (1.2) of the pattern "A". As a result, the LCD 30 produces a display, as shown in FIG. 7, in accordance with the display data of pattern height data (1.5) and pattern length data (1.2) supplied thereto. It is to be noted that, since patterns in the present embodiment are arranged in a horizontal row in the forward and rearward direction, as viewed by an operator (FIG. 6), pattern height data are displayed as a distance in the leftward and rightward direction while pattern length data are displayed as a distance in the forward and rearward direction.
If an operator operates the combination designating switch 34 in order to combine a pattern "n" with the pattern "A", then the combination designating switch 34 supplies a combination designating signal to the CPU 46. When such combination designating signal is received, the CPU 46 judges at step SP6 whether the combination designating switch 34 has been operated, and the control sequence advances to step SP7. At step SP7, the CPU 46 increments the address value 0001 to obtain a new address value 0002 which designates an area into which uppermost and lowermost position data and pattern length data of a next pattern are to be stored. Then, the CPU 46 returns the control sequence to step SP2. When the pattern "n" is selected as the next pattern, steps SP3, SP4 and SP5 are again executed. If the combination designating switch 34 is operated at step SP6, in order to combine a further pattern "g" with the pattern "n", the CPU 46 executes step SP7 and returns the control sequence to step SP2.
After steps SP2 to SP7 are repeated to select and combine the patterns "A", "n", "g", "e" and "1", such data as seen in FIG. 5 are stored in the storage areas of the address values of 0001 through 00005, in order of entry, of the RAM 54. The shapes of the patterns and distances of the entire combination pattern in the leftward and rightward direction and also in the forward and rearward direction are displayed on the LCD 30 (FIG. 8). In this instance, the maximum uppermost position data among the patterns of the combination are the uppermost position data (1.5) of the pattern "A". Meanwhile, the maximum lowermost position data among the patterns of the combination are the lowermost position data (0.3) of the pattern "g". Accordingly, the uppermost position data (1.5) of the pattern "A" and the lowermost position data (0.3) of the pattern "g" are added to obtain pattern height data (1.8). The pattern height data (1.8) are displayed as a distance of the combination pattern in the leftward and rightward direction. Further, the pattern length data of all of the patterns (1.2, 0.8, 0.7, 0.5, 0.7) are added and a value of 3.9, obtained by the addition, is displayed as a distance of the combination pattern in the forward and rearward direction.
Since an operator can identify the placement and dimensions of the combination pattern as applied to the work fabric by observing the values displayed on the LCD 30, accurate positioning of the work fabric with respect to the sewing needle 18 can be accomplished readily. Then, if the start/stop switch 38 is operated by the operator, the sewing machine starts the sewing operation to form the combination pattern (FIG. 6) at the predetermined position on the work fabric.
A second embodiment of the present invention will be described with reference to FIGS. 9 to 14. It is to be noted that description of elements common to those of the first embodiment will be omitted herein.
In the present embodiment, the CPU 46 is constructed such that, when power is made available to the sewing machine 10, it operates in accordance with a flow chart shown in FIG. 9. The ROM 50 has stored therein a program for operating the CPU 46, stitch data for forming various patterns and display data for allowing the shape of a pattern to be displayed. The ROM 50 further has stored therein pattern width data and pattern length data representative of sizes of various patterns as shown in the table of FIG. 10. The RAM 52 stores therein pattern codes corresponding to selected patterns in an order in which the patterns are combined. The RAM 52 further stores temporarily therein pattern width data and pattern length data of patterns in an order in which the patterns are combined as seen in the table of FIG. 11. It is to be noted that, in FIGS. 10 and 11, data are represented not in the form of actually stored data but in the form of actual patterns and sizes for convenience.
Operation of the sewing machine 10 of the present embodiment will be described with reference to the flow chart of FIG. 9. After power is made available to the sewing machine 10, the CPU 46 executes an initializing operation at step SP11. The initializing operation also includes setting to 0001 an address value which designates an area of the RAM 52 into which pattern width and length data are to be stored.
Subsequently, if an operator operates the pattern selecting switch 28 at step 12 to select, for example, a pattern "A" of a small size in order to start forming a combination pattern, as shown in FIG. 12, a pattern code representative of the small size pattern "A" is supplied from the pattern selecting device 44 to the CPU 46. At step SP13, the CPU 46 stores a pattern code corresponding to the small size pattern "A" into the RAM 52. The CPU 46 then reads, from the ROM 50, display data for allowing a shape of the small size pattern "A" to be displayed and outputs the display data to the LCD 30. The CPU 46 then reads, from the ROM 50, pattern width data (0.8) and pattern length data (0.7), shown in FIG. 10, corresponding to the small size pattern "A" and stores the pattern width data (0.8) and pattern length data (0.7), corresponding to the small size pattern "A", into the storage area of the address value 0001 of the RAM 54 as seen in FIG. 11.
Subsequently, the CPU 46 selects, at step SP14, a maximum value among the pattern width data stored in the storage areas of the address values of 0001 et seq. of the RAM 54 and outputs the data to the LCD 30. In the case where only the small size pattern "A" is selected, only one pattern width data is stored in the storage areas of the address values of 0001 et seq. of the RAM 54 and, accordingly, the CPU 46 outputs the pattern width data (0.8) of the small pattern "A". Subsequently, the CPU 46 adds, at step SP15, all of pattern length data stored in the storage areas of the address values of 0001 et seq. of the RAM 54 and outputs the sum to the LCD 30. In the case where only the small size pattern "A" is selected, only one pattern length data is stored in the storage areas of the address values 0001 et seq. of the RAM 54 and, accordingly, the CPU 46 outputs the pattern length data (0.7) of the small size pattern "A". As a result, the LCD 30 displays the pattern width data and pattern length data supplied thereto. It is to be noted that patterns in the present embodiment are arranged in a horizontal row in the forward and rearward direction as viewed by an operator, shown in FIG. 12. Therefore, the pattern width data are displayed as a distance in the leftward and rightward direction while pattern length data are displayed as a distance in the forward and rearward direction.
If the operator operates the combination designating switch 34, in order to combine a pattern "B" of a medium size with the small size pattern "A", the combination designating switch 34 supplies a combination designating signal to the CPU 46. When such combination designating signal is received, the CPU 46 judges at step SP16 that the combination designating switch 34 has been operated and the control sequence advances to step SP17. At step SP17, the CPU 46 increments the address value 0001 to obtain a new address value 0002 which designates the area into which pattern width data and pattern length data of the next pattern are to be stored. Then, the CPU 46 returns the control sequence to step SP12. When the medium size pattern "B" is selected as a next pattern, the steps SP13, SP14 and SP15 described above are executed. If the combination designating switch 34 is again operated at step SP16, in order to combine a further pattern "C" of a large size with the medium size pattern "B", the CPU 46 executes the processing at step SP17 described above and then returns the control sequence to step SP12.
After the processings at steps SP12 to SP17 are repeated to select and combine the chosen patterns, such as the small size pattern "A", medium size pattern "B", large size pattern "C", medium size pattern "D" and small size pattern "E", of this example shown in FIG. 11, the pattern width and length data are stored in the storage areas of the address values of 0001 et seq. of the RAM 54. Further, the shapes of the patterns and the dimensions of the combination pattern in the leftward and rightward direction and the forward and rearward direction are displayed on the LCD 30 as shown in FIG. 14. In particular, the pattern width data (2.5) of the large size pattern "C" is displayed as a distance in the leftward and rightward direction. Further, the pattern length data of all of the patterns (0.7, 1, 2, 1, 0.7) are added, and a value of 5.4, obtained by the addition, is displayed.
Since the operator can observe the dimensions of the entire combination pattern of the selected patterns displayed on the LCD 30, accurate positioning of the work fabric with respect to the sewing needle 18 can be performed quickly such that the finished, sewn pattern lies completely within the desired sewing area. Then, if the start/stop switch 38 is operated by the operator, the sewing machine starts a known sewing operation to form the combination pattern, shown in FIG. 12, at the predetermined position on the work fabric.
The present invention is not limited to the first and second embodiments described in detail hereinabove, and many changes and modifications can be made thereto without departing from the spirit and scope of the invention as set forth herein.
For example, while a work fabric is fed by the feed dog 24 in the first and second embodiments, it may otherwise be fed using an embroidery frame or the like on which it is held.
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In a sewing machine, a visual display provides the operator not only a representation of how a stitch pattern will appear but also provides dimension data in both the fabric feed direction and in a cross-feed, transverse, direction. The dimensions are determined by using width data for the widest element of the pattern, or the portion of the width of the elements extending above and below a reference line and adding the greatest uppermost and greatest lowermost extensions, and a sum of the length data for each element of the pattern.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation-in-part of U.S. patent application Ser. No. 14/087,583, Filed Nov. 22, 2013, the contents of which are incorporated by reference as if set forth in their entirety herein.
BACKGROUND
[0002] Various outdoor and indoor activities incorporate and are centered around an open source of fire, from log bonfires to wood burning stoves. As the popularity of hiking and camping and other recreational activities increase, more individuals will be utilizing open fires, like log fueled fires, to provide heat for cooking and warmth, among other things. Outdoor tailgates at football and other sporting events often include charcoal barbeque grills. Indoor fireplaces that are fueled, at least in part, by wooden logs or the equivalent, as well as the types of outdoor fires mentioned, require to be properly ignited and maintained.
[0003] Proper ignition and maintenance of a log or charcoal fire, or the equivalent, can include providing enough air to circulate oxygen and fuel areas of the fire while it kindles. Other ways to maintain a camp or cook fire include rearranging the material fueling the combustion so that air can be more evenly and efficiently circulated around the burning matter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] Various features and advantages of the invention will become apparent from the following description of embodiments of the invention, given by way of example only, which is made with reference to the accompanying drawings, of which:
[0005] FIG. 1 is a schematic illustrating an embodiment of the fire stoking and poking system;
[0006] FIG. 2A illustrates a system operable according to embodiments of the present invention;
[0007] FIG. 2B illustrates a system that retracts via a telescoping hollow rod, and operable according to embodiments of the present invention;
[0008] FIG. 2C illustrates a system that extends via a telescoping hollow rod, and operable according to embodiments of the present invention;
[0009] FIGS. 3A , 3 B, 3 C, 3 D, 3 E, 3 F, 3 G, 3 H, 3 I, 3 J, 3 K, 3 L, 3 M, and 3 N are schematic diagrams illustrating embodiments of a fire stoking and poking system including a design theme; and
[0010] FIG. 4 is a process flow diagram showing a method of providing oxygen to a fire while rearranging the burning combustible matter of the fire.
SUMMARY
[0011] An example of the current techniques includes a system for stoking a fire with air and arranging materials in a fire. The stoking and poking system includes an air flow generator connected to a power source. The system also includes a hollow rod connected to the air flow generator, wherein the hollow rod is configured to conduct air sent from the air flow generator at an outlet or number of outlets of the hollow rod.
[0012] Another example includes a method for stoking a fire and rearranging combustible matter in a fire. The method includes generating a flow of air at an air flow generator, and flowing the flow of air from the air flow generator through a hollow rod that is connected to the air flow generator at a near end of the hollow rod. The method also includes stoking a fire with a far end of the hollow rod, wherein the far end of the hollow rod is configured to outlet the flow of air generated by the air flow generator. The method discloses altering a position of combustible matter in the fire with the far end of the hollow rod while the flow of air is conducted through an outlet of the hollow rod.
DETAILED DESCRIPTION
[0013] The present disclosure provides systems and techniques for stoking and poking combustible material in a fire. Exemplary embodiments of the current system include providing air and oxygen to select areas of a fire while simultaneously rearranging the combustible particles into preferred positions. Through the system disclosed herein, a user is able to prod the constituent matter of the fire and reposition material for desired burning, while air is being conducted at certain areas of the fire. The system can be made from a hollow metal rod or a similar structure that is configured to be resistant, at least in part, to damage from fire and excessive heat.
[0014] FIG. 1 is a schematic illustrating an embodiment of the fire stoking and poking system 100 . The system 100 is configured to attach an air flow generator 102 to a hollow rod 104 at a point of attachment/detachment 106 , so the hollow rod 104 can be disconnected from the air flow generator 102 when preferred. The hollow rod 104 can be configured to include a handle 108 . The air flow generator 102 can be a battery powered blower, a fan system including an electric motor and a fan connected to a rotatable shaft of the electric motor (not shown). The air flow generator 102 can include an “On/Off” switch 110 that may be toggled to start or stop generating a flow of air.
[0015] The air flow generator 102 can be housed by a housing. The housing of the air flow generator 102 can include a handle 112 , as the hollow rod 104 can include a handle 108 , for safer and easier use of the system 100 . The hollow rod 104 can include a hook 114 as shown in the exemplary embodiment in FIG. 1 , or a prong structure that is effective at moving burning wood, as embodied by another example. The hook 114 permits a user to more effectively break-up and relocate burning material in a fire. The air flow generator 102 , together with the hook 114 and durable hollow rod 104 , create an effective tool for a user to stoke a flame with oxygen provided by air generated by the air flow generator 102 . The generated air is configured to be conducted through an outlet or multiple outlets at the end of the hollow rod 104 .
[0016] FIG. 2A illustrates a system 200 operable according to embodiments of the present invention. The system 200 shows how the hollow rod 204 is configured to be telescoping, and is able to collapse into a compacted position 220 or extend into an extended position 222 . The poking and stoking system 200 is configured to attach an air flow generator 202 to a hollow telescoping rod 204 at a point of attachment/detachment 206 . Thus, the hollow telescoping rod 204 can simply be connected and disconnected from the air flow generator 202 when preferred, and the telescoping rod 204 retreated to meet compact storage needs.
[0017] The hollow telescoping rod 204 can be made of a series of hollow rods of progressively smaller diameters. The hollow rods of various diameter are coupled at various diameter sleeves 208 along the hollow telescoping rod 204 . The hollow rods of various diameter can extend and retract and the orientation of the diameter sleeves 208 will dictate where the various points of expansion and retraction may occur. When fully extended, the hollow telescoping rod 204 can optionally be configured to lock in the extended position, adding to the durability and ensuring the desired repositioning functionality.
[0018] The hollow telescoping rod 204 can be lightweight, and can be configured to include a handle 210 . The air flow generator 202 can be a fan system including an electric motor and a fan connected to a rotatable shaft of the electric motor (not shown). The air flow generator 202 can be powered from a variety of sources, including a standard lithium or alkaline battery, or other types of batteries, an electrical connection via a power cord and energized electrical outlet, or even a battery configured to store energy generated by solar or wind power. The air flow generator 202 can include an “On/Off” switch 210 . The switch 210 can be toggled by a user to start or stop generating a flow of air. The fan of the air flow generator 202 can optionally be a variable speed fan, and an additional switch (not shown) for controlling the speed of the fan can also be implemented.
[0019] The air flow generator 202 can be housed by a housing. The housing of the air flow generator 202 can optionally include a handle 212 , and the hollow rod 204 can include a handle 210 , for more safe and easy use of the poking and stoking system 200 . The hollow telescoping rod 204 can include a hook 216 as shown in the exemplary embodiment in FIG. 2 . The hook 216 permits a user to more effectively break-up and relocate burning material in a fire. The hollow telescoping rod 204 must be configured to withstand damage from flames and excessive heat. The telescoping hollow rod 204 is also configured to be strong enough to withstand the force of repositioning combustible materials, like wooden logs, in a fire without the fully-extended rod 204 bending or breaking.
[0020] The air flow generator 202 , together with the hook 214 and durable telescoping hollow rod 204 , create an effective tool for a user to stoke a flame with oxygen provided by air generated at the air flow generator 202 . Air that is generated is configured to be conducted through an outlet 218 at the end of the hollow telescoping rod 204 . There can be one or more than one outlet 218 at the end of the hollow telescoping rod 204 where the generated air is directed to flow out. The generated air may fuel the flames of a fire while the hook 214 or prong at the end of the hollow telescoping rod 204 can prod material into desired positions. Furthermore, the telescoping design of the hollow rod 204 , in addition to the attachment/detachment interface 206 , allows users to conveniently break down, and more easily store and carry the poking and stoking system 200 . The end of the hollow rod can be pointed as indicated for more effective poking and moving of materials. The air from the air flow generator 202 can still flow out of the far end of the hollow rod 204 , but will exit through an outlet 218 upstream of the pointed end.
[0021] The system 200 described herein is useful for individuals on the move, and with limited space for packing a conventional device for fire maintenance. The system 200 is configured to advantageously maintain a non-gas lit fire, whether burning indoors outdoors, by stoking some areas and materials while simultaneously pulling and prodding around other areas and materials of the fire.
[0022] FIG. 2B illustrates a system 200 that retracts via a telescoping hollow rod, and operable according to embodiments of the present invention. The figure shows how only a small amount of space 220 is occupied by the hollow telescoping rod when the rod has been retracted into its most compact position. The hollow telescoping rod 204 is configured to attach and detach from the air flow generator 202 for easy storage and accessibility.
[0023] FIG. 2C illustrates a system 200 that extends via a telescoping hollow rod, and operable according to embodiments of the present invention. The figure indicates the extended length 222 of the hollow telescoping rod 204 . When the system 200 is in this extended position 222 , some embodiments of the claimed method and system can be utilized, i.e., poking and rearranging of burning matter while simultaneously stoking the flame. In both FIGS. 2B and 2C , the handle 210 is facing in a downward direction, in the same plane as the air flow generator. Also, both these figures show a hook 216 that is oriented in the down position.
[0024] The schematic of FIGS. 2A , 2 B and 2 C is not intended to indicate that the system 200 is to include all of the components shown in FIGS. 2A , 2 B and 2 C. Further, any number of additional components may be included within the system 200 , depending on the details of the specific implementation. For example, additional hooks or air flow outlets can be included to achieve the desired stoking and poking of the combustible material of a fire.
[0025] FIG. 3A is a schematic illustrating an embodiment of a fire stoking and poking system 300 including a design theme. The design theme can be a custom-made design theme functioning as a housing for the system 300 . Like-numbered components can be described, for example, with respect to FIG. 1 . The system 300 of FIG. 3A illustrates a baseball-themed outer casing 301 that surrounds the air flow generator 102 . The outer casing 301 can be in the shape and style of a baseball, while functioning as a rigid exterior for the air flow generator 102 and system 300 .
[0026] FIG. 3B illustrates a system 300 that extends and retracts via a telescoping hollow rod, includes a design theme, and is operable according to embodiments of the present invention. Like-numbered components can be described, for example, with respect to FIG. 2 . The system 300 of FIG. 3B illustrates a baseball-themed outer casing 302 that surrounds the air flow generator 202 . The outer casing 302 can be in the shape and style of a baseball, while functioning as a rigid exterior for the air flow generator 202 and system 300 .
[0027] FIG. 3C is a schematic illustrating an embodiment of a fire stoking and poking system 300 including a design theme. Like-numbered components can be described, for example, with respect to FIG. 1 . The system 300 of FIG. 3C illustrates a football-themed outer casing 303 that surrounds the air flow generator 102 . The outer casing 303 can be in the shape and style of a football, while functioning as a rigid exterior for the air flow generator 102 and system 300 .
[0028] FIG. 3D illustrates a system 300 that extends and retracts via a telescoping hollow rod, includes a design theme, and is operable according to embodiments of the present invention. Like-numbered components can be described, for example, with respect to FIG. 2 . The system 300 of FIG. 3D illustrates a football-themed outer casing 304 that surrounds the air flow generator 202 . The outer casing 304 can be in the shape and style of a football, while functioning as a rigid exterior for the air flow generator 202 and system 300 .
[0029] FIG. 3E is a schematic illustrating an embodiment of a fire stoking and poking system 300 including a design theme. Like-numbered components can be described, for example, with respect to FIG. 1 . The system 300 of FIG. 3E illustrates a soccer-themed outer casing 305 that surrounds the air flow generator 102 . The outer casing 305 can be in the shape and style of a soccer ball, while functioning as a rigid exterior for the air flow generator 102 and system 300 .
[0030] FIG. 3F illustrates a system 300 that extends and retracts via a telescoping hollow rod, includes a design theme, and is operable according to embodiments of the present invention. Like-numbered components can be described, for example, with respect to FIG. 2 . The system 300 of FIG. 3F illustrates a soccer-themed outer casing 306 that surrounds the air flow generator 202 . The outer casing 306 can be in the shape and style of a soccer ball, while functioning as a rigid exterior for the air flow generator 202 and system 300 .
[0031] FIG. 3G is a schematic illustrating an embodiment of a fire stoking and poking system 300 including a design theme. Like-numbered components can be described, for example, with respect to FIG. 1 . The system 300 of FIG. 3G illustrates a basketball-themed outer casing 307 that surrounds the air flow generator 102 . The outer casing 307 can be in the shape and style of a basketball, while functioning as a rigid exterior for the air flow generator 102 and system 300 .
[0032] FIG. 3H illustrates a system 300 that extends and retracts via a telescoping hollow rod, includes a design theme, and is operable according to embodiments of the present invention. Like-numbered components can be described, for example, with respect to FIG. 2 . The system 300 of FIG. 3H illustrates a basketball-themed outer casing 308 that surrounds the air flow generator 202 . The outer casing 308 can be in the shape and style of a basketball, while functioning as a rigid exterior for the air flow generator 202 and system 300 .
[0033] FIG. 3I is a schematic illustrating an embodiment of a fire stoking and poking system 300 including a design theme. Like-numbered components can be described, for example, with respect to FIG. 1 . The system 300 of FIG. 3I illustrates a football-themed outer casing 309 that surrounds the air flow generator 102 . The outer casing 309 can be in the shape and style of a football helmet, while functioning as a rigid exterior for the air flow generator 102 and system 300 .
[0034] FIG. 3J illustrates a system 300 that extends and retracts via a telescoping hollow rod, includes a design theme, and is operable according to embodiments of the present invention. Like-numbered components can be described, for example, with respect to FIG. 2 . The system 300 of FIG. 3J illustrates a football-themed outer casing 310 that surrounds the air flow generator 202 . The outer casing 310 can be in the shape and style of a football helmet, while functioning as a rigid exterior for the air flow generator 202 and system 300 .
[0035] FIG. 3K is a schematic illustrating an embodiment of a fire stoking and poking system 300 including a design theme. Like-numbered components can be described, for example, with respect to FIG. 1 . The system 300 of FIG. 3K illustrates a hockey-themed outer casing 311 that surrounds the air flow generator 102 . The outer casing 311 can be in the shape and style of a hockey puck, while functioning as a rigid exterior for the air flow generator 102 and system 300 .
[0036] FIG. 3L illustrates a system 300 that extends and retracts via a telescoping hollow rod, includes a design theme, and is operable according to embodiments of the present invention. Like-numbered components can be described, for example, with respect to FIG. 2 . The system 300 of FIG. 3L illustrates a hockey-themed outer casing 312 that surrounds the air flow generator 202 . The outer casing 312 can be in the shape and style of a hockey puck, while functioning as a rigid exterior for the air flow generator 202 and system 300 .
[0037] FIG. 3M is a schematic illustrating an embodiment of a fire stoking and poking system 300 including a design theme. Like-numbered components can be described, for example, with respect to FIG. 1 . The system 300 of FIG. 3M illustrates a racecar-themed outer casing 311 that surrounds the air flow generator 102 . The outer casing 313 can be in the shape and style of a stock car or racing vehicle, while functioning as a rigid exterior for the air flow generator 102 and system 300 .
[0038] FIG. 3N illustrates a system 300 that extends and retracts via a telescoping hollow rod, includes a design theme, and is operable according to embodiments of the present invention. Like-numbered components can be described, for example, with respect to FIG. 2 . The system 300 of FIG. 3N illustrates a racecar-themed outer casing 314 that surrounds the air flow generator 202 . The outer casing 312 can be in the shape and style of a stock car or racing vehicle, while functioning as a rigid exterior for the air flow generator 202 and system 300 .
[0039] The schematics of FIGS. 3A , 3 B, 3 C, 3 D, 3 E, 3 F, 3 G, 3 H, 3 I, 3 J, 3 K, 3 L, 3 M, and 3 N are not intended to indicate that the system 300 is to include all of the components shown in FIGS. 3A , 3 B, 3 C, 3 D, 3 E, 3 F, 3 G, 3 H, 3 I, 3 J, 3 K, 3 L, 3 M, and 3 N. Further, any number of additional components may be included within the system 300 , depending on the details of the specific implementation. For example, various additional themes can be used as functional housings for an air flow generator that are aesthetically pleasing. Custom-made design themes can also be used as examples for an outer casing of the fire poking and stoking system described herein.
[0040] FIG. 4 is a process flow diagram showing a method of providing oxygen to a fire while rearranging the burning combustible matter of that fire. The method for stoking a fire and repositioning combustible matter in a fire 400 begins at block 402 , where a flow of air is generated at an air flow generator. The air flow generator can be a fan connected to a rotatable shaft of an electric motor, and the electric motor can receive electrical power from a variety of different sources. The air flow generator effectively pumps oxygen to a fire to stoke combustion where the air flow is directed.
[0041] The method 400 continues at block 404 , when air from the air flow generator is flowed through a hollow rod that is connected to the air flow generator at a near end of the hollow rod. The near end of the hollow rod is configured to readily attach and detach from a point of attachment found on the housing of the air flow generator. The fan or blower connected to the electric motor is configured to pump air from the near end of the hollow rod to an outlet at the far end of the hollow rod.
[0042] At block 406 , a fire is stoked with the far end of the hollow rod, wherein the far end of the hollow rod is configured to outlet the flow of air generated by the air flow generator. There can be a single outlet or there can be multiple outlets at the end of the hollow rod. An outlet at the far end of the hollow rod is configured to conduct a concentrated stream of air and oxygen pumped from the near end of the hollow rod to fuel a particular area of a fire.
[0043] At block 408 , the position or placement of combustible matter in the fire is altered by using the far end of the hollow rod while the flow of air is conducted through an outlet of the hollow rod. The hollow rod should be structurally configured to endure, without significant bending, the force and stress associated with altering, prodding, or repositioning heavy combustible matter in a fire, such as a wooden log. The hollow rod can optionally be aligned telescopically, wherein the hollow rod is configured to extend and collapse on itself, thereby saving space while maintaining functionality. The hollow rod can also be configured to include a hook or a prong mechanism at the far end of the hollow rod, making the task of arranging the combustible material in a fire more simple and effective.
[0044] The process flow diagram of FIG. 4 is not intended to indicate that the steps of the method 400 are to be executed in any particular order, or that all of the steps of the method 400 are to be included in every case. Further, any number of additional steps not shown in FIG. 4 may be included within the method 400 , depending on the details of the specific implementation.
[0045] While the present techniques may be susceptible to various modifications and alternative forms, the embodiments discussed above have been shown only by way of example. However, it should again be understood that the techniques are not intended to be limited to the particular embodiments disclosed herein. Indeed, the present techniques include all alternatives, modifications, and equivalents falling within the true spirit and scope of the appended claims.
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The present invention is directed toward a system for stoking and arranging materials in a fire. An air flow generator is configured to flow air down a passage in a hollow rod that is configured to prod and rearrange the combustible matter of a burning fire. The hollow rod is durable enough to poke and reposition the combustible materials in a fire. While this poking and repositioning is occurring, air sent from the air flow generator is conducted at an outlet of the hollow rod, thereby stoking the flame burning the combustible matter while the combustible matter is also being poked and prodded at. The hollow rod can be configured to be a telescoping hollow rod that is permitted to extend and collapse on itself for more convenient storage and transport options.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of priority under 35 U.S.C. §119(e) to U.S. Provisional Patent Application No. 62/186,042, filed Jun. 29, 2015. The disclosure set forth in the referenced application is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] This invention relates generally to a method for media blasting and finishing a gear or other workpiece or part. The powered part hold-down apparatus of U.S. Pat. No. 5,272,897 may be used for the peening step(s) of the present disclosure, and the disclosure of the U.S. Pat. No. 5,272,897 is hereby incorporated in its entirety by this reference. Elements of other known methods of media blasting and finishing, such as the peen finishing method and apparatus of U.S. Pat. No. 8,453,305, may be used for the present disclosure, and the disclosure of the U.S. Pat. No. 8,453,305 is hereby incorporated in its entirety by this reference.
[0003] Media blasting or peening is used to increase the fatigue strength of a gear, workpiece or part. Gears, such as those utilized in automobile transmissions are media blasted to increase their surface durability and ensure that they are suitable for performing their intended functions. As an example, media blasting with steel peening may be used for strengthening the root radius of the teeth of a geared workpiece. The media blasting steps of the present invention includes the steps disclosed in U.S. Pat. No. 6,612,909 and the disclosure of the U.S. Pat. No. 6,612,909 is hereby incorporated in its entirety by reference.
[0004] When media blasting a workpiece, such as a gear, the workpiece is placed in a closed chamber and the blasting system is actuated, whereby media are mixed with air. After mixing of the media and air, a stream of the air/media mixture is directed against the workpiece, often through increased or high-speed application. This process is referred to as peening.
[0005] A variety of materials/media may be used for the workpiece, depending on the ultimate application or outcome desired by the workpiece. In automotive applications, it is often desires to increase the strength or hardness of the media in order to have more favorable KSI. In the present disclosure, toughness is discussed in terms of “KSI” (kilo-pound[-force] per square inch) or 1000 psi. KSI is often used in materials science, civil and mechanical engineering to specify stress and Young's modulus. A higher KSI is favorable for materials that will be under larger compressive stresses.
[0006] When a workpiece, in particular a workpiece made of media that has a high KSI, is peened, the peening material is blasted against the surface of the workpiece, removing and modifying the microscopic landscape of the surface. When a workpiece includes sharp or distinct edges, such as the tip of a gear tooth, those edges or tips may be unintentionally radiused from the blasting of the peening material, such that a mushroom effect occurs on the edge or tip of the gear tooth. This mushroom effect may alter the operation or functionality of the workpiece. Even if the mushroom effect does not alter the operation or functionality of the workpiece, it may create unwanted noise when the workpiece engages with other components during operation. It is understood that the higher the KSI of a workpiece, the more the tips may be radiused during a peening process.
OBJECTS AND SUMMARY OF THE INVENTION
[0007] An object of the present invention is to remove or reduce the effect of radiused tips that may be created when a workpiece is subjected to a peening process by subjecting the workpiece to a spindle-finishing process after it has been peened. For a workpiece with gear teeth or other similar sharp edges, the peening process may be applied to strengthen the root radius and tooth face of gears by peening the gears and then optionally subjected to a vibratory finishing process. The peening step(s) toughen the gears and provide roughness to the gear surfaces. The spindle-finishing process after peening removes or reduces the mushrooming effect on the radiused tips that occurs during the peening process.
[0008] An object of the present invention is to provide a method of processing a metallic workpiece with defined edges (e.g., a gear) comprising media blasting of the workpiece by directing a first media (e.g., cut wire) against exposed surfaces on the workpiece to increase the root strength of the gear, ceasing the media blasting, loading the workpiece into a spindle-finishing apparatus, and subjecting the workpiece to a finishing process with a second media (e.g., metal, plastic, synthetic, glass, ceramic or FINE STEEL®), the exposed surfaces on the workpiece being subjected to the finishing process to reduce radiused tips on the workpiece created from the media blasting. In illustrative embodiments, the process of moving the workpiece to the spindle-finishing apparatus from the media blasting may be performed automatically by a machine. Once the workpiece has been subjected to the finishing process (spindle machine or vibe machine) with the second media, it may be removed from the spindle-finishing machine, washed, and rinsed with rust inhibitor whereby wear properties of the workpiece are enhanced. Media blasting and subsequent finishing of gears according to the present invention accomplishes an important object which is to reduce or eliminate undesired radiused tips of the gears.
[0009] Another object of the present invention is to provide a workpiece (e.g., a gear, shaft or other metal parts) with a higher KSI strength that has been media blasted/peened such that radiused tips exist on one or more tips or edges of the workpiece, and subsequently processing the workpiece with a fine finishing process (e.g., spindle-finishing or vibe-finishing process) to provide a reduction or elimination of the radiused tips of the workpiece as compared to before the fine finishing process.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The present invention will now be described, by way of example, with reference to the accompanying drawings in which:
[0011] FIG. 1 is a front elevational view of an exemplary media blasting apparatus for treating a workpiece according to the first media blasting process of the invention;
[0012] FIG. 2 is a right-side elevational view of the media blasting apparatus of FIG. 1 ;
[0013] FIG. 3 is a top plan view of the media blasting apparatus of FIG. 1 ;
[0014] FIG. 4 is an enlarged, partial fragmentary, side elevational view of a blast station of a first exemplary media blasting apparatus for treating a workpiece according to the invention;
[0015] FIG. 5 is schematic of a first media blasting apparatus and a second spindle finishing apparatus, and an exemplary transportation process between a first media blasting apparatus and the second spindle-finishing apparatus;
[0016] FIG. 6 is aside elevation view of an exemplary spindle-finishing apparatus;
[0017] FIG. 7 is a top view of an exemplary part or workpiece that may be processed by an exemplary media blasting apparatus and an exemplary spindle-finishing apparatus;
[0018] FIGS. 8A-8C are detailed view of the gear teeth of the workpiece of FIG. 7 before the workpiece is subjected to a first exemplary media blasting, after it is subjected to a first exemplary media blasting but before it is processed in the second spindle-finishing apparatus, and after it is processed in the second spindle-finishing apparatus, respectively;
[0019] FIGS. 9A-9C are microscopic views of a single gear tooth of the workpiece of FIG. 7 before the workpiece is subjected to a first exemplary media blasting, after it is subjected to a first exemplary media blasting but before it is processed in the second spindle-finishing apparatus, and after it is processed in the second spindle-finishing apparatus, respectively; and
[0020] FIGS. 10A-10C are cross-sectional views of a single gear tooth of the workpiece of FIG. 7 before the workpiece is subjected to a first exemplary media blasting, after it is subjected to a first exemplary media blasting but before it is processed in the second spindle-finishing apparatus, and after it is processed in the second spindle-finishing apparatus, respectively.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0021] Referring now to the drawings, FIGS. 1-4 illustrate a first media blasting apparatus according to the invention, generally indicated by the number 10 . FIGS. 5-6 illustrated a second finishing apparatus according to the invention, generally indicated by the number 200 . FIGS. 8A, 9A and 10A illustrate a teeth-portion of a workpiece prior to the workpiece being subjected to processing in the first media blasting apparatus 10 . FIGS. 8B, 9B and 10B illustrate the teeth-portion of the workpiece after processing in the first media blasting apparatus 10 but before it is subjected to processing in the second finishing apparatus 200 . FIGS. 8C, 9C and 10C illustrate the teeth-portion of a workpiece after processing in the second finishing apparatus 200 .
[0022] The first media blasting apparatus 10 will now be described. As illustrated, the first media blasting apparatus 10 includes a blasting cabinet or chamber 15 , in which a stream of media is directed against a workpiece 20 . Such media may comprise, for example, cut wire, glass beads, ceramic beads or fine steel beads. The cabinet 15 is connected to a cabinet media hopper 25 for collecting the media that fall after collision with the workpiece 20 . The fallen media will include broken pieces of media which have been recycled, as well as virgin or unbroken pieces. A conduit 30 connects the cabinet media hopper 25 to a media reclaim system, generally indicated by the number 35 . As best illustrated in FIG. 2 , the cabinet media hopper 25 is also connected to air supply means 40 . The air supply means 40 provides air flow to the cabinet media hopper 25 , for forcing the collected fallen media up through the conduit 30 to the media reclaim system 35 .
[0023] As illustrated in FIGS. 1 and 2 , the media reclaim system 35 includes a conduit 45 for conveying collected media to separation means 50 . In illustrative embodiments, the separation means 50 may be a two-deck system comprising a top screen 55 and a bottom screen 60 . In a preferred embodiment of the present invention, the top screen is between 20 and 40 mesh gauge and the bottom screen is between 170-200 mesh gauge. The separation means 50 generally separates the fallen media into unbroken media and broken media of sufficiently large size to be recycled for use in the first blasting operation and fines or dust which cannot be reused in the first media blasting apparatus 10 . The separator screens 55 and 60 are constantly vibrated to increase the efficiency of separation.
[0024] As illustrated in FIG. 1 , the separation means 50 of the first media blasting apparatus 10 may be connected to a double pressure chamber 90 via a conduit 95 . A media path may be defined between the cabinet media hopper 25 and the pressure chamber 90 . In a preferred embodiment, the double pressure chamber is held between 70 and 80 psi. The conduit 95 delivers the reclaimed reusable media to the double pressure chamber 90 where the reclaimed and reusable media are mixed with virgin media. In a preferred embodiment, the reclaimed media are of a mesh size greater than 100 mesh and the virgin media are of a mesh size between 60-100 mesh and preferably between 60-80 mesh. As stated previously, in the present invention, the media of the first medial blasting apparatus 10 may comprise glass, ceramic, or fine steel beads. The virgin media are supplied to the double pressure chamber 90 through a plurality of media supply valves 97 . The double pressure chamber 90 is also coupled to a media sensor monitor 100 for automatically controlling the supply of the virgin media. The supply of the virgin media is controlled to ensure adequate peening of the workpiece. Specifically, the supply of the virgin media is controlled to ensure that adequate compression stress is provided to the workpiece 20 so that a sufficiently high fatigue strength is obtained upon blasting. The double pressure chamber 90 may further include a media metering on/off valve 105 .
[0025] A further advantage of the pressurized system is that it helps ensure an adequate media velocity is obtained. As mentioned above, media velocity is an important control parameter in ensuring that sufficient compressive stress is provided to a workpiece 20 . The pressurized system helps ensure an adequate media velocity through control of the media flowrate and through the positioning of the air/media mix point. The media flowrate is controlled through the media metering valve 105 . The air/media mix point is located sufficiently far from the blast hose so that the media have time to develop a desired or adequate velocity before being blasted onto a workpiece.
[0026] An exemplary blasting station 120 inside the blasting cabinet 15 of the first media blasting apparatus 10 will now be described. As illustrated in FIG. 4 , the workpiece 20 to be processed, i.e., blasted with media, is mounted on a part holder 125 . Preferably, the part holder 125 has been hardened. In illustrative embodiments, the workpiece 20 is held in a predetermined position by a powered part hold-down apparatus 130 . In the present invention, the powered part-hold-down apparatus 130 is preferably that described in U.S. Pat. No. 5,272,897, to which reference is again invited. The subject matter of U.S. Pat. No. 5,272,897 is incorporated herein by reference. The patented powered part-hold-down apparatus 130 provides variable, compensating, cushioned clamping for maintaining the workpiece 20 in the predetermined position during media blasting. The device as taught in U.S. Pat. No. 5,272,897 is very important to facilitate processing high volume quantities of parts. This is especially important for parts such as gears which tend to rotate when peened since the hold-down device prevents free spinning of the parts. The hold-down device also controllably rotates the parts at a desired rate of rotation. Rotation of the powered part-hold-down apparatus 130 is provided via a rotatable shaft 135 .
[0027] In illustrative embodiments, hardened rods 140 , preferably steel, provide a support system for a gun-rack assembly 145 of the blasting station 120 . As illustrated in FIG. 4 , the gun-rack assembly 145 holds a nozzle holder 150 . A blast nozzle 155 , to which the blasting hoses 115 are connected, is attached to the nozzle holder 150 . The blast nozzle 155 directs a stream of media, suspended in air, against the surface of the workpiece 20 . Preferably, the blast nozzle is positioned between approximately four to eight inches away from the workpiece 20 . Although only one blast nozzle 155 is illustrated in FIG. 4 , it will be understood to those skilled in the art that a plurality of blast nozzles 155 could be used. In a preferred embodiment of the present invention, four such blast nozzles 155 are located in the blasting cabinet 15 , as shown in FIG. 3 . The blasting cabinet 15 , containing the part-hold-down apparatus 130 and blasting apparatus 120 is also provided with a door 160 for installation of a new workpiece 20 .
[0028] Operation of the first media blasting device 10 will now be described. After a workpiece 20 is placed in the part-hold-down apparatus 130 , door 160 is closed. A stream of media suspended in air is then directed against the workpiece 20 by the blast nozzle 155 . As the media are blasted, the workpiece is controllably rotated by the powered patented part-hold-down apparatus 130 . This controlled rotation ensures even peening of the surface of the workpiece 20 and obviates use of a high directivity stream of media, hence making the use of water-supported media unnecessary, allowing for the media to be streamed via an air-media mixture as discussed above.
[0029] The powered part-hold-down apparatus 130 is preferably rotated at between 8-12 rpm. A rate of rotation of 10-12 rpm, however, has been found to be particularly effective for treatment of gears. The rate of rotation can be related to the degree of peening required and to the evenness of dimpling on the resulting surface. A slow controlled rotation permits even peening with uniform small dimpling and prevents the media stream from striking the surface unevenly, resulting in indentations that could act as crack precursors. Thus, for example, if the workpiece 20 is a gear, the controlled rotation ensures that media, e.g. cut wire, ceramic beads, fine steel beads, or glass beads, are directed towards the root and tooth face of the gear during the course of the rotation. By ensuring even peening, the operational characteristics of the workpiece 20 are improved.
[0030] In a one embodiment a smaller mass flowrate of media is blasted at higher velocity and for a longer time than in the prior art methods. The preferred flowrate depends on the type and size of media used, as well as the particular application involved. For treatment of gears, we have found a media flowrate of approximately 1.5-3 lb/minute to be effective. Of course, other flowrates could be used, depending on the results desired. This flowrate was found to be effective with glass media, ceramic media, and fine steel media of mesh size falling in the range of 50-100 mesh. In a preferred embodiment of the present invention, however, 60-100 mesh glass media are used. When 60-100 mesh glass media were used to treat certain gears, including those made using 8620 steel or other material with a high KSI, a marked improvement in the operational characteristics of such gears was observed. The choice of media to be used depends upon the application and the relative economics. Ceramic and steel media last longer than glass; however, these media are more expensive. As with the rate or rotation, the flowrate and media used may be configured to ensure even peening of the workpiece.
[0031] The process of even peening may provide unintentional material change in the part being processed. In particular and as relevant to the present disclosure, the rate of rotation, peening media, flowrate, etc, all affect the condition of the surface of the workpiece. When processing a gear or other workpiece with teeth or other types of features that have tips, edges, or corners (e.g. sharp edges), the intensity of the peening flow against the workpiece, and in particular against the tips or edges of the workpiece, has been known to cause an unintentional mushrooming effect on the tips or edges, as illustrated for example in FIGS. 8B, 9B and 10B . This mushrooming effect causes the tips or edges to be radiused tips 350 that extend outward (e.g. from the side or top surfaces of the teeth). Such mushrooming may be considered problematic for the operation of a workpiece for a variety of reasons, including creating issues with the functionality, life-expectancy and/or noise output of the workpiece in operation.
[0032] An exemplary embodiment of a workpiece 201 with features that have tips, edges, or corners as envisioned within the scope of this disclosure will now be described, although other forms of such features with tips, edges or corners are also envisioned within the scope of this disclosure. As illustrated in FIG. 7 , the workpiece 201 , such as a gear or other part, includes a plurality of teeth 220 a , 220 b , 220 c , etc with channels 240 a , 240 b , 240 c , etc. therebetween. The teeth 220 include at least a first side surface 230 and a second side surface 232 , as illustrated in FIG. 7 , that extend upward from a base 250 of the workpiece 201 toward a top end 224 of the tooth 220 . The second side surface 232 a of a first tooth 220 a is spaced apart from the first side surface 230 b of a second tooth 220 b to form a channel 240 a therebetween. After processing, the teeth 220 are illustratively designed and configured to engage with other gears or parts (not shown) in operation, as is known in the art, by positioning the teeth 220 of one gear into the channels 240 of a second gear. In illustrative embodiments, the teeth 220 may be tapered to be wider near the base 250 of the workpiece 201 than at the top end 224 . Further, in illustrative embodiments, the teeth 220 may be angled or curved in nature such that the teeth curve along the base 250 , as illustrated in FIG. 7 . Other variations of teeth formation are well known in the art and envisioned as applicable to the present disclosure.
[0033] Each tooth 220 includes one or more edges 222 along a top end 224 of the tooth 220 . In exemplary embodiments, the tooth 220 may include a single edge 222 along the top end 224 , the edge 222 defining the transition from the first side surface 230 and the second side surface 232 of the tooth 220 . In other exemplary embodiments, and as illustrated n FIG. 8A , a tooth 220 a may include at least a first edge 222 a and a second edge 228 a along the top end 224 a . In illustrative embodiments, the first edge 222 a and second edge 228 a may be spaced apart from each other, with the edge 222 a positioned between the first side surface 230 a and a top surface 236 a of the tooth 220 a , and the edge 228 a positioned between the top surface 236 a and the second side surface 232 a of the tooth 220 a . The corresponding channel 240 of the second gear with which the tooth 220 a interacts should be sized accordingly to receive the tooth 220 a (e.g. if the tooth 220 a includes a first edge 222 a and a second edge 228 a spaced apart from the first edge 222 a , the corresponding channel 240 may have a larger width). As the workpiece 201 is typically cut from hardened media, such as steel, the edges 222 between the first side surface 230 a /second side surface 232 a and the top surface 236 a may be sharp or distinct after cutting, as illustrated for example in FIGS. 8A, 9A, and 10A .
[0034] After a geared workpiece 201 is processed in the first media blasting apparatus 10 , the edges 222 of the teeth 220 may have radiused tips 350 , as discussed previously and as illustrated in FIGS. 8B, 9B and 10C . In order to reduce the undesired features of the radiused tips 350 , further processing by the second finishing apparatus 200 is disclosed. The second finishing apparatus 200 includes further processing media that eliminates or reduces the radiused tips 350 from the edges 222 of the teeth 220 , as illustrated in FIGS. 8C, 9C and 10C .
[0035] The operation of the second finishing apparatus 200 will now be described. The second finishing apparatus 200 may be, for example, a spindle apparatus or a vibe apparatus. In illustrative embodiments, the finishing apparatus 200 includes a bowl 208 , a spindle unit 260 that can transfer parts into the bowl 208 , and motor 282 that can rotate the bowl 208 , as illustrated in FIGS. 5 and 6 . After peening occurs in the first media blasting apparatus 10 , the gear 201 is transferred to and secured on the spindle unit 260 of the second finishing apparatus 200 . The bowl 208 contains a fine finishing medium 212 which may be a wet or dry medium, such as plastic, synthetic, ceramic or steel media. As noted with the media of the first blasting apparatus 10 , the finishing media 212 may be of a variety of sizes and types and still fall within the scope of this invention. The fine finishing medium 212 is preferably a wet acidic medium or slurry, or it may be a dry medium.
[0036] The finishing apparatus 200 is depicted in FIGS. 5 and 6 . In illustrative embodiments, the bowl 208 of the finishing apparatus 200 has an outlet 202 , an inlet 204 , sides 206 , an open top 209 , and a bottom 210 , as illustrated in FIG. 6 . The inlet 204 may be configured to permit transfer of finishing medium 212 into the bowl 208 , while the outlet 202 may permit transfer of finishing medium 212 out of the bowl 208 . The bowl 208 may be configured to retain the finishing medium 212 during the second finishing process. In illustrative embodiments, the bowl 208 is vibrated at a high speed frequency. The vibration of the bowl 208 of the finishing apparatus 200 may be performed via one or more vibration belts or spindles 216 coupled to and driven by the motor 282 . In other illustrative embodiments, the bowl 208 is rotated to rotate the finishing medium 212 . The bowl 208 may be rotated such that the finishing medium 212 moves at a high number of revolutions. For example, the bowl 208 may rotate the finishing medium at speeds up to 1000 surface feet per minute. The bowl 208 may be configured to rotate clockwise or counterclockwise. In still other embodiments, the bowl 208 may include a supplemental mixing blade 252 positioned within the bowl 208 near the bottom 210 , the mixing blade 252 configured to rotate the medium 212 within the bowl 208 at a different speed that the rotation of the bowl 208 . The bowl 208 is typically made of steel and may have a polyurethane liner (not shown) which can transfer the vibrations or rotations of the bowl 208 to the medium 212 .
[0037] In illustrative embodiments, the centrifugal force created within the bowl 208 during rotation may spin the selected finishing medium 212 into a form-fitting grinding wheel (not shown). In other embodiments, if the bowl 208 and/or medium 212 within the bowl 208 is rotated at a slower rotation speed, the slurry of finishing medium 212 may remain dispersed throughout the bowl 208 . As an example, it may be beneficial to rotate the bowl 208 at a slower speed in order to assure uniform deburring and finishing of all surfaces of a workpiece.
[0038] In illustrative embodiments, the second finishing apparatus 200 includes two or more spindles 260 a , 260 b , etc., as depicted in FIG. 6 . In various embodiments, each spindle 260 may process a single part or a cluster of small parts depending on the design of the spindle 260 . The spindle 260 include a head 262 onto which the workpiece 201 may be securely coupled or connected. The spindle 260 may further include a connection arm 264 to which the head 262 is coupled, the connection arm 264 being permitted to pivot and rotation upon direction of a computer or other electronic system (not shown) accordingly to the requirements of operation or input from an operator of the finishing apparatus 200 . In illustrative embodiments, the head 262 may also be configured to rotate or pivot with respect to the connection arm 264 . Alternatively, the head 262 may be connected to an extension arm 266 that rotates with respect to the connection arm 264 , as indicated by the path of rotation 270 as illustrated in FIGS. 5 and 6 . The extension arm 266 and/or head 262 may be configured to rotate clockwise or counterclockwise. The entire spindle 260 may work together to position the part 201 coupled to the head 262 within the slurry of finishing medium 212 , as illustrated in FIG. 6 .
[0039] In illustrative embodiments, prior to operation of the finishing apparatus 200 , finishing medium 212 may be pumped into the bowl 208 via a connection line 254 that is coupled to the inlet 204 . Similarly, a connection line 256 may extend from the outlet 202 of the bowl 208 to permit drainage of the finishing medium 212 when the finishing apparatus 200 is not in use or the finishing medium 212 is replaced. The finishing apparatus 200 may include an overflow tank 258 to receive and store finishing medium 212 , the overflow tank being connected to the connection lines 254 and 256 . In illustrative embodiments, a pump 268 may be positioned within the overflow tank 258 or along the connection line 254 to pump the finishing materials 212 into the bowl 208 .
[0040] In illustrative embodiments, the finishing medium 212 may be a wet acidic fine finishing medium that is sufficient to wet the gears 201 and ceramic media 212 . In other embodiments, the finishing medium may be dry. The relative size of the gear 201 and media 212 may vary depending on the type of gear, media, and desired finished product. The relative size of the media 212 and gears 201 is such that the media 212 is small enough to fit into the space between the gear teeth 220 so that during fine finishing (vibration/rotation), the edges 222 and 228 of the teeth are subjected to the finishing process. One example of a fine finishing medium 212 comprises a mixture of ceramic media with a slightly acidic solution. Such finishing may be continued to reduce or remove the radiused tips 350 of the gear teeth 220 .
[0041] In illustrative embodiments, the finisher apparatus 200 may be used to finish the side surfaces of the gear, including the surfaces of the gear teeth 230 and 232 , in addition to the edges 222 and 228 . In a preferred embodiment a gear is coupled to the spindle 260 , and the edges and surfaces of the gear that are desired to be fine-finished are submerged into the finishing media 212 . The head 262 or extension arm 266 of the spindle 260 rotates the gear or part 201 , while the spindle 260 holds the gear 201 in a stationary position relatively to the rest of the bowl 208 . In illustrative embodiments, the bowl 208 may also vibrate and rotate as discussed previously. The rotation and/vibration of the head 262 , extension arm 266 , and/or bowl 208 is continued for a time sufficient to reduce the radius of the tips or edges, as discussed herein.
[0042] During rotation and/or vibration (fine finishing), additional water and/or fine finishing medium may be added via one or more inlets 204 . Excess fine finishing medium, water etc, may be removed via outlet 202 . In illustrative embodiments, fine finishing may be continued to smooth the gear (workpiece) surfaces in addition to reducing or removing the radiused tips 350 of the gear teeth 220 . Such finishing may also provide small indentations on the other surfaces of the gear, which may improve compressive stress and oil retention features of the gear.
[0043] After sufficient processing in the second finishing apparatus 200 , the radiused tips 350 of the teeth 220 of the gear 201 may be substantially lower in profile, as shown at 370 , as illustrated in FIGS. 8C, 9C and 10C , or be removed altogether. For example, in illustrative embodiments, the radiused tips 350 of the teeth 220 prior to the second finishing process may be a certain width W 1 across, as shown in FIG. 9B . After the second finishing process, the radiused tips 370 may have a smaller width W 2 that the width W 1 of the radiused tips 350 prior to the second finishing process, as illustrated in FIG. 9C .
[0044] After fine finishing the gear is removed from the bowl, washed, and rinsed. The gear may be further treated with rust inhibitor in a final step whereby a gear with enhanced wear properties is provided.
[0045] In illustrative embodiments, the gear may be transported from the first media blasting apparatus 10 to the second finishing apparatus 200 via any known conventional transportation means. In an exemplary embodiment, the transportation means may be fully automated without user input. For example, the transportation means may include a removal apparatus 380 that removes the part 201 from the part-hold-down apparatus 130 of the media blasting apparatus 10 , as illustrated in FIG. 5 . The removal apparatus may include an electronically controlled hand 382 that can grasp and retain the part 201 , as well as a pivotable and/or rotatable arm 384 that can rotate the part to engage with the head 262 of the spindle 260 to connect the part 201 to the head 262 . In other embodiments, the rotatable arm 384 may rotate the hand 382 holding the part 201 to a movable track or conveyor system 386 which conveys the part 201 to a location where the spindle 260 may rotate or pivot to pick up the part 201 , as illustrated in FIG. 5 . Other methods of automatic transportation are known in the art.
[0046] In another embodiment the gears are fine finished in a bowl without the addition of liquid medium (i.e., with dry fine finishing medium). In this embodiment the gears are in effect fine finished while dry and in the presence of wear material that smoothes the gear surface, but wherein the wear material is not in liquid form. Coupling vibrations and/or rotations to the container to vibrate the fine finishing medium with the gear reduces the size of indentations on the surfaces of the gear during the second finishing process, leaving compressive stress and oil retention advantages remaining on the gear surface. The edges of the teeth resulting after finishing has smoothness and the radiused tips 350 are reduced, as discussed above, with the surface of the teeth, and in particular the edges of the teeth, having indentations resulting from peening and reduced by but remaining after finishing.
[0047] For gears treated by the above-discussed preferred two-step process of media blasting followed by fine finishing, tests confirm that gears so treated exhibit superior performance relative to gears not treated with this process. It has been found that gears treated with this preferred process exhibit reduced noise-generation when the gears are used in operation. Other advantages may be found as well, including superior fatigue strength and less failure of gears to operate properly due to a misconnection between gear teeth from the mushrooming effect.
[0048] While the method of media blasting and finishing for gears is disclosed herein with respect to a hold down apparatus, it is contemplated that other conventional part holders and blasting apparatus may also be used with the steps described herein. The above discussed process recognizes that most often gears need steel peening at the gear root to prevent fatigue bending in the root radius.
[0049] The applicant has provided description and figures which are intended as an illustration of certain embodiments of the invention, and are not intended to be construed as containing or implying limitation of the invention to those embodiments. It will be appreciated that, although applicant has described various aspects of the invention with respect to specific embodiments, various alternatives and modifications will be apparent from the present disclosure which are within the spirit and scope of the present invention as set forth in the following claims.
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A method and apparatus for processing a metallic workpiece with defined edges (e.g., a gear) comprises media blasting of the workpiece by directing a first media against exposed surfaces on the workpiece to increase the root strength of the gear, the blasting causing the defined edges to be radiused or mushroomed, ceasing the media blasting, loading the workpiece into a finishing apparatus, and subjecting the workpiece to a finishing process with a second media, the exposed surfaces on the workpiece being subjected to the finishing process to reduce the radiused edges on the workpiece created from the media blasting. The process of moving the workpiece to the spindle-finishing apparatus from the media blasting may be performed automatically by a machine. Once the workpiece has been subjected to the finishing process with the second media, it may be removed from the spindle-finishing machine, washed, and rinsed with rust inhibitor whereby wear properties of the workpiece are enhanced.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority, under 35 U.S.C. §119(e), to U.S. Patent Application No. 61/088,856, filed on Aug. 14, 2008, the contents of which are herein incorporated by reference in its entirety.
BACKGROUND OF INVENTION
1. Field of the Invention
Embodiments disclosed herein relate generally to improved tool joints or other wear surfaces used in wellbore operations. In particular, embodiments disclosed herein relate generally to methods of applying wear resistant materials to and otherwise improving the properties of tool joints or other wear surfaces.
2. Background Art
Drilling wells for hydrocarbon recovery involves the use of drill pipes, to which at one end, a drill bit is connected for drilling through the formation. Rotational movement of the pipe ensures progression of the drilling. Typical pipes may come in sections of about 30 feet in length, and thus, these sections are connected to one another by a tool joint. Tool joints are the connecting members between sections of drill pipe—one member (the box) has an internal thread and the mating member (the pin) has an external thread, by which means they are assembled into a continuous unit with the drill pipe to form a drill string. Often, these tool joints have a diameter significantly larger than the body of the pipes, thus requiring protection against wear, particularly when drilling through highly abrasive, highly siliceous earth formations. In particular, as drilling proceeds, the tool joints rub against the drilled hole and/or drilled hole lining (i.e., casing). The strength of the connection is engineered around the wall thickness and heat-treated properties of the box above the thread. During drilling, the wall thickness above the thread thins as it rubs against the wall or casing. Thus, the life of the pipe is predicated upon the remaining strength of the tool joint.
Because increasing the life of the tool joint is desirable, there have been numerous attempts to provide weld a protective hardfacing alloy or cladding to the tool joint (or other wear prone surfaces such as a stabilizer or drill collar) to form a hardband. A variety of methods have been used to apply such wear-reducing materials to joints, including: GMAW (gas metal arc welding), GTAW (gas tungsten arc welding), PTA (plasma transferred arc), and FCAW (flux cored arc welding). These welding processes are characterized by establishing an arc between an electrode (either consumable or non-consumable) and a tool joint base material. Once this arc is established, intense heat forms a plasma. The gas that forms the plasma is furnished by means of an external gas or an ingredient from a tubular wire. The temperature of the plasma is in excess of 10,000 degrees Kelvin and is highest at the center of the weld, and decreases along the width of the weld.
Historically, and in practice, tool joints have been coated with tungsten carbide to resist the abrasion of the rock earth in the drill hole on the tool joint. However, tungsten carbide is expensive, it can act as a cutting tool to cut the well casing in which it runs, and the matrix is a soft steel which erodes away easily to allow the carbide particles to fall away.
Other prior art hardfacing materials used that are harder than siliceous earth materials are brittle and crack in a brittle manner after solidification and upon cooling due to the brittle nature of its structure and the inability of the structure to withstand solidification shrinkage stresses and typically emit sound energy upon cracking as well as causing considerable casing wear as previously stated. These hardfacing materials are alloys which belong to a well-known group of “high Cr-irons” and their high abrasive resistance is derived from the presence in the microstructure of the Cr-carbides of the eutectic and/or hypereutectic type.
Siliceous earth particles have a hardness of about 800 Brinell hardness number (BHN). In U.S. Pat. No. 5,244,559 the hardfacing material used is of the group of high Cr-irons that contains primary carbides which have a hardness of about 1700 Hv in a matrix of a hardness of at least 300 BHN to 600 Hv. These primary carbides at this high hardness are brittle, have little tensile strength and hence pull apart on cooling from molten state at a frequency that depends on the relative quantity of the primary carbides in the mix of metal and carbide. Thus, this type of hardfacing material, which is harder than siliceous earth materials, when applied by welding or with bulk welding, form shrinkage cracks across the weld bead. This material has been applied extensively and successfully during many years for the hardbanding of tool joints and hardfacing of other industrial products.
Although these materials have become and still are widely accepted by the trade, users expressed a desire for a hardbanding tool joint alloy combining casing-friendliness with the capability of being welded free of brittle cracks in order to minimize any concerns of mechanical failure risks. Indeed, in most industries (including the oil and gas industry's use of down hole drilling equipment) the metal components which make up the structure and equipment of a given plant must have integrity, which means being free of any kind of cracks, because such cracks might progress through the piece and destroy the part.
U.S. Pat. No. 6,375,865 describes an alloy having a martensitic-austenitic microstructure which is preheated before welding to the industrial product and cooled down after welding. Alloys of this structural type can be deposited crack-free (further aided by the pre- and post-treatments and are characterized by excellent metal to metal wear properties and low brittleness.
Wear by abrasion mechanisms always has been, and still remains a main concern in many segments of industry, including the drilling industry. However, there is some limitation on the types of materials that may be used due to limitations of their use with GMAW, GTAW, PTA, and FCAW, as well as limitations on the types of materials which do not harm the casing.
Accordingly, there is a continuing need for developments in methods of improving the properties of a tool joint or other wear surfaces by applying treatment techniques and/or material in order to increase the component's service life.
SUMMARY OF INVENTION
In one aspect, embodiments disclosed herein relate to a method for applying a wear reducing material to a tool used in a wellbore operation that includes welding a hardfacing alloy to a surface of the tool, wherein the welding comprises friction stirring the alloy into the tool's surface.
In another aspect, embodiments disclosed herein relate to a method for applying a wear reducing material to a tubular member used in a wellbore operation that includes locating a preformed sleeve of a high melting temperature hardfacing alloy concentric with an outer surface of the tubular member at a desired location; and welding the preformed sleeve to the outer surface of the tubular member, wherein the welding comprises friction stirring the alloy into the tool's outer surface.
In yet another aspect, embodiments disclosed herein relate to a method for applying a wear reducing material to a tool used in a wellbore operation that includes locating a preformed, malleable width of a high melting temperature hardfacing alloy on an outer surface of the tool; and welding the preformed width to the outer surface of the tool, wherein the welding comprises friction stirring the alloy into the tool's outer surface.
Other aspects and advantages of the invention will be apparent from the following description and the appended claims.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a fragmentary longitudinal sectional view of a box of a tool joint with a raised hardband according to one embodiment.
FIG. 2 is a view similar to FIG. 1 illustrating a pin of the tool joint with a raised hardband according to one embodiment.
FIG. 3 is a view similar to FIG. 1 illustrating flush hardbanding of a box of the tool joint according to another embodiment.
FIG. 4 is a view similar to FIG. 1 illustrating flush hardbanding of a pin of the tool joint according to another embodiment.
FIG. 5 is a longitudinal view of a stabilizer hardbanded according to one embodiment.
FIGS. 6A to 6D illustrate use of a friction stir welding tool in accordance with one embodiment.
FIGS. 7A to 7D illustrate formation of a weld in accordance with one embodiment.
FIG. 8 is a schematic of one embodiment of a hardband weld.
DETAILED DESCRIPTION
In one aspect, embodiments disclosed herein relate to formation of hardbands on the surface a tool used in a wellbore operation. In particular, embodiments disclosed herein relate to formation of a hardband weld using friction stir welding.
The methods of the present disclosure may be used to form a hardband or layer of wear reducing material on any type of tool used in a wellbore operations. However, particular embodiments may relate to use of friction stir welding to apply hardbanding to a region of a downhole tool or component having a greater OD than other adjacent components, thus necessitating wear protection for the component. For example, components having a greater OD than other adjacent downhole components may include drill pipe joints, drill collars, stabilizers, etc. However, one skilled in the art would appreciate that the methods of the present disclosure are not so limited, and friction stir welding may instead be used to apply a wear reducing material to any downhole component.
Friction stir welding uses a combination of rotational and orbital motion applied to the interface between the two objects to weld two pieces together. A rotating member is conventionally applied to the interface (joint) and is moved in an orbital fashion until a plasticized state of the material is achieved. The rotating member is moved along the interface to create a bonded seam between the two objects.
Thus, the friction stir welding process generally involves engaging the material of two adjoining workpieces on either side of a joint by a rotating stir pin or spindle. Force is exerted to urge the spindle and the workpieces together, and frictional heating caused by the interaction between the spindle and the workpieces results in plasticization of the material on both sides of the joint. The spindle is traversed along the joint, plasticizing the material at the joint as it advances, and the plasticized material left in the wake of the advancing spindle cools and solidifies to form a weld.
One example operation of a friction stir welding tool is shown in FIGS. 6A to 6D . As shown in FIG. 6A to 6D , two workpieces (e.g., workpieces, 60 a , and 60 b ), are aligned so that edges of the workpieces 60 a and 60 b to be welded together are held in direct contact along interface 62 . A friction stir welding tool 65 has a shoulder 64 at its distal end, and a welding pin 66 extending downward centrally from the shoulder 64 . As the rotating tool 65 is brought into contact with the interface 62 between workpieces 60 a and 60 b , the pin 66 is forced into contact with the material of both workpieces 60 a and 60 b , as shown. The rotation of the pin 66 in the material produces a large amount of frictional heating of both the welding tool pin 66 and shoulder 64 and at the workpiece interface. The heating tends to soften the material of the workpieces 60 a and 60 b in the vicinity of the rotating pin 66 , thereby inducing a plasticization and commingling of material from the two workpieces 60 a and 60 b to form a weld 68 .
However, as shown in FIG. 6A to 6D and described above in its conventional use, the friction stir welding tool is moved along the interface in such a manner that the pin or spindle of the tool presses into the interface at an orientation that is co-planar with the interface/seam between the two objects. One skilled in the art would appreciate that when applying a wear resistant layer onto an outer surface of a tool, such as a sleeve being welded onto a tubular, the pin or spindle of the friction stir welding tool is oriented perpendicular to the interface or seam plane. Depending on the component being hardbanded and its configuration, one skilled in the art would appreciate that either orientation of the tool may be used.
The types of material that may be hardbanded in accordance with the embodiments disclosed herein may depend on the desired material properties for the particular application, such as hardness, toughness, casing-friendly wear resistance, etc., as well as the type of wellbore in which the tool is being used (cased or open hole). However, in particular embodiments, the hardfacing alloy being hardbanded may include ferrous alloys, such as steel, as well as iron- nickel-, copper-, and cobalt-based alloys. In using friction stir welding, alloys previously unweldable by conventional welding techniques may be welded using friction stirring. Additional elements in the types of materials being welded include, but are not limited to, chromium, molybdenum, manganese, silicon, carbon, boron, tungsten, aluminum, titanium, niobium, tantalum, vanadium, nickel, cobalt, zirconium, phosphorus, and rhenium. Some of these alloys used in hardbanding may be described as “high melting temperature compounds,” or compounds having a melting temperature greater than steel. Other such high melting temperature compounds may form the base material of the tool components being used downhole. However, lower melting temperature alloys may also be used. Further, in open-hole drilling (where casing-friendliness is not as necessary), the alloy may be provided with tungsten carbide particles dispersed therein.
In addition to being able to weld a greater number of alloys previously unweldable by conventional welding techniques, a greater hardness of the wear reducing material may be achieved. For example, by using friction stirring a greater hardness by about 5 to 15 Rockwell C points (when comparing a friction stir weld to a conventional weld, using the same material) may be achieved. That is, for an alloy that would have a hardness ranging from 45 to 55 Rockwell C when using conventional welding, a hardness of about 50 to 70 Rockwell C may be achieved when using friction stirring. Such improved hardness may result from the change in the material microstructure (i.e., through grain refinement/recrystallization to produce fine precipitates such as carbides). Another byproduct of the friction stirring techniques of the present disclosure may be a reduction in the surface roughness, i.e., reduced asperity heights, as compared to a conventional weld.
In order to weld the high melting materials used in the present disclosure, referring back to FIG. 6A to 6D , the pin 66 and the shoulder 64 of the friction stir welding tool may be coated with a superabrasive material. In one embodiment, polycrystalline cubic boron nitride (PCBN) may be used as a superabrasive coating on a substrate material being used for the shoulder 64 with the integral pin 66 . In a preferred embodiment, rather than a coating, the shoulder 64 and the pin 66 (which may or may not be integrally formed with the shoulder) are formed of polycrystalline cubic boron nitride themselves, rather than being coated. Tools suitable for use in the methods of the present disclosure may include tools similar to those discussed in U.S. Pat. Nos. 7,124,929, 7,270,257, and U.S. Patent Publication No. 2005/0082342, which are assigned to the present assignee and herein incorporated by reference in their entirety.
Referring now to FIGS. 1 and 2 , one example of a downhole tool, in particular, a drill pipe joint that has been provided with hardbanding by friction stir welding is shown. As shown in FIGS. 1 and 2 a tool joint 10 for drill pipe 14 is illustrated as having a box 12 at the end of the drill pipe 14 that is internally threaded at 16 . Internal threads 16 of box 12 threadedly receive a pin 18 having co-acting threads 20 to the threads 16 so that the pin 18 may be threaded into box 12 . The pin 18 forms the end of a drill pipe, such as 14 , so that a string or joints of pipe may be threadedly secured together and disconnected for drilling oil, gas, and other wells.
The box 12 and the pin 18 are enlarged and have outer cylindrical surfaces 22 having an outer diameter greater than the outer diameter of the drill pipe 14 onto which hardbanding 24 is deposited. In such an embodiment, the outer diameter of the coupling at the hardband 24 is greater than the outer cylindrical surfaces 22 such that the hardband preferentially contacts the borehall wall or casing when the tool joint is employed in a drill string. One skilled in the art would appreciate that when selecting the outer diameter of the hardband 24 , care should be taken, with consideration as to the borehole diameter in which the drill string is being used to reduce adverse effects on annular flow of drilling fluids through the borehole to the surface. For example, such thickness of the hardbanding may range from about about 3/32 to ¼ inch thick without detriment to the alloy properties and may be deposited in single or double layers.
Referring now to FIGS. 3 and 4 , another embodiment of a tool joint 30 for drill pipe 34 is shown. Tool joint 30 is similar to tool joint 10 of FIGS. 1 and 2 except that tool joint 30 has a reduced cylindrical portion 46 formed by either the removal of a circumferential band of material from the outer cylindrical surfaces 42 of the box 32 and the pin 38 or was originally formed with these reduced diameter sections 32 , and the hardbanding 44 is welded in this space so that the surface of the weld deposited hardfacing is substantially flush with the outer cylindrical surface 42 of the box 32 and the pin 38 . One skilled in the art would appreciate that when a flush hardbanding is desired, an amount of material similar to the thickness of the hardband 24 shown in FIGS. 1 and 2 may be removed from the tool joint 30 so that a similar thickness of hardband 44 may be deposited thereon and be flush with the outer surfaces 42 .
Referring to FIG. 5 , a stabilizer 50 according to the present disclosure is illustrated. Stabilizier 50 has an elongated cylindrical or pipe-like body 52 having a pin 51 and box 56 for connection in a string of drill pipe (not shown). The stabilizer 50 possesses stabilizer ribs 58 extending outwardly from body 52 for stabilizing the drill pipe in a well bore (not shown). Hardbanding alloy 54 is welded to stabilizer ribs 58 . Further, while the methods of the present disclosure is particularly suited for hardbanding tool joints and stabilizers, it may be applied to any surface requiring hardbanding or facing, such as drill collars, structural members, process components, abrasion resistant plates, and the like.
Thus, while the present application is directed to the general use of friction stir welding to weld a hardfacing alloy to the outer surface of a downhole tool, specific embodiments are also directed to the various techniques by which a hardfacing alloy may be provided to, located relative to, and affixed to the underlying tool surface. For example, the hardfacing alloy may be provided in a variety of shapes and forms. One example embodiment, shown in FIGS. 7A to 7D , may include a preformed sleeve 72 of a hardfacing alloy for use with a tubular member. A sleeve (full or split) 72 may be slid onto a box end 74 of a joint 70 of pipe 76 , where the box end 74 has a larger outer diameter as compared to the remainder of the pipe 76 . It may be located (and temporarily affixed) at the region of joint 70 desired to have wear protection. A friction stir welding tool 65 (having shoulder and pin components as described above) may be brought into contact with sleeve 72 . As the tool 65 rotates and is forced normal to the surface of the sleeve 72 /joint 70 , frictional heating generated from the rotation of the tool 65 softens the material of the sleeve 72 and joint 70 (in the area proximate the sleeve 72 ) in the vicinity of the rotating tool 65 , thereby inducing a plasticization and commingling of material from the sleeve 72 and joint 70 to form a hardband 78 welding onto the surface of joint 70 . Further, while sleeve 72 may be located on joint 70 simply by sliding the sleeve to the desired location, sleeve 72 may optionally be interference fit or tack-welded to the desired location.
Moreover, while a sleeve is generally considered to a relatively rigid material (not readily deformable during the positioning of the alloy on the tool), other embodiments may use a non-rigid, malleable material that may be somewhat deformed during the positioning of the alloy on the tool. For example, instead of a preformed sleeve of material, a preformed, malleable width of alloy (for example, wire or wider strip) may be positioned on the tool, taking the general shape-form of the tool surface (i.e., for a tubular member, a wire or strip of alloy may be wrapped around the circumference of the tubular). Thus, such materials may be supplied in (or formed to have) various widths, ranging from several millimeters to several centimeters, for example, from about 5 mm to about 5 cm. However, one skilled in the art would appreciate that smaller or larger widths may also be used. Thus, depending on the size, the materials may be formed such as by wire-drawing or by high shear compaction (or tape-casting) methods known in the art.
Further, to aid in relative placement of such malleable materials on a tool, a tackifying agent or adhesive may be used so that the alloy may be accurately placed in the desired location of the tool. Upon placement of the alloy on the tool, the alloy and tool part may be welded together, similar to as described above, using friction stir welding. Alternatively, it is also within the scope of the present disclosure that such a malleable material is continuously fed onto (or wrapped around) a tool ahead of the friction stir welding tool moving along the metal-tool interface yet to be welded.
Moreover, it is also within the scope of the present disclosure that during the welding process, welding the entire hardband region may be accomplished in one or more passes, depending, for example, on the width of the material to be welded to the tool. Thus, for example, for a hardband wider than an available friction stir welding tool, multiple passes of welding 88 a , 88 b may be performed, such as shown in FIG. 8 . During such multiple passes, some embodiments may change the direction of rotation of the tool while other embodiments may use the same rotation direction between the multiple passes. Further, one skilled in the art would appreciate that during the welding process, some of the base material adjacent the desired or newly formed weld may also be stirred despite not having an additional material mixed therewith.
A byproduct of the welding techniques of the present disclosure may be a reduction in the surface roughness, i.e., reduced asperity heights. For example, in one embodiment, a hardband applied using the methods of the present disclosure may have a reduced asperity height as compared to a conventionally applied weld.
Further, the hardbanding of the present disclosure is generally repairable. Thus, in particular, the downhole components may be repeatedly recoated with a hardbanding layer, either in a shop or in the field at the rig location. Further, when performing a re-coat, the friction stir welding of a new metal alloy into the used pipe may be performed on the same or different earlier weld type.
Advantageously, embodiments of the present disclosure may provide for at least one of the following aspects. Conventional welding processes present limitations on the types of hardbanding materials that can be used in hardbanding a downhole toole. For example, using welding techniques conventionally used in hardbanding, e.g., gas metal arc welding, the hardbanding material options are limited. Specifically, materials that are casing friendly are difficult to weld, and result in cracking (despite pre- and post-heat treatments) due to the stresses which arise in the microstructure during the liquid-to-solid transition during welding. Moreover, materials which are more easily weldable using conventional means (such as conventional tungsten carbide containing hardbands) are known to wear down a casing string.
However, using the welding methods of the present disclosure, the number of materials that may be used with the friction stir welding techniques does not posses the same limitations associated with conventional gas arc welding. By having fewer (or no) limitations on the types of material that may be used, the techniques may be used to apply welds that are either casing or open-hole friendly. Further, in addition to having broader choice in hardband materials, the solid-state processing principles associated with friction stir welding may likely reduce the microstructure defects, reducing the incidence of cracking. By reducing the incidence of cracking, the need for additional heat processing treatments, such as pre- and/or post-heat treatments may be eliminated. Additionally, the welding technique may be less hazardous, which may also allow for the hardbanding to be placed at any given location, including at the rig site, allowing for better rebuild service. Lower asperity heights may also be achievable, giving a smoother finish, and reducing an apparent need for surface finishing or grinding.
While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims.
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A method for applying a wear reducing material to a tool used in a wellbore operation that includes welding a hardfacing alloy to a surface of the tool, wherein the welding comprises friction stirring the alloy into the tool's surface is disclosed. Methods of welding a preformed sleeve or width of wear reducing material using friction stirring are also disclosed.
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CROSS REFERENCE OF RELATED APPLICATION
[0001] This is a U.S. National Stage under 35 U.S.C. 371 of the International Application PCT/CN2014/088954, filed Oct. 20, 2014, which claims priority under 35 U.S.C. 119(a-d) to CN 201410476502.1, filed Sep. 17, 2014.
BACKGROUND OF THE PRESENT INVENTION
Field of Invention
[0002] The present invention relates to hydraulic system technical field, and more particularly to a variable-speed volume-control direct-drive all-electric hydraulic excavator driving and energy recovery system adopts distribution mutual redundancy electric control energy sources.
Description of Related Arts
[0003] With the remarkable development of engineering machinery, excavator has already become one of the pillar industries. How to effectively reduce the energy consumption of the hydraulic excavator in action has become an intermediate problem we are facing. The research on the energy recovery of the dynamic system, transmission system and hydraulic system is a key hot point in domestic and international engineering field.
[0004] Conventionally the energy source of hydraulic excavator mainly is internal combustion engine which drives the hydraulic pump and works with the control valve to realize the action of multiple hydraulic actuators. In order to reduce the energy loss of the hydraulic excavator load sensitive control and negative control is the most frequently adopted technology which has the disadvantage of increasing the energy consumption and heating due to the big throttle loss on the actuator with low load pressure; in order to improve the overall energy efficiency of the hydraulic excavator a hybrid energy technology appears which adopts hybrid energy source to control the running of generator. The hybrid energy technology improves the efficiency compared to the internal combustion engine while still has the problem of big throttle loss and discharge pollution.
[0005] All-electric drive is the direction of future development which is able to reduce energy loss, running cost and discharge pollution by combining the electric-control and hydraulic control. In 2005, Komatsu Ltd invented a pneumoelectric hydraulic excavator the boom, arm, bucket differential cylinder and swing device on the bus of which are controlled by eight dual-quantitative pump driven by four servo motor respectively based on the closed circuit theory (U.S. Pat. No. 6,962,050 B2). In 2007, Takeuchi MFG. Co., Ltd. realized the electric-driven of the hydraulic excavator with the strategy of single motor single pump, single motor dual-pump and dual-motor dual-pump (European patent EP 1985767 A1). In 2013, Hitachi Construction Machinery Co., Ltd. invent an all-electric hydraulic excavator which adopts five servo motor, four main pump and one slippage pump and combines the pump-control differential cylinder closed circuit and complex differential cylinder gap area compensate circuit to realized the boom, arm and swing drive and control (US 20130312399 A1); In 2013, Chinese patent CN 103255790 A published a mutual DC bus electric hydraulic excavator which adopts a combination of pump-control closed circuit and mutual DC bus to realize the all-electric drive and control for the boom and the arm. Due to the above mentioned electric-drive technology adopts the pump-control circuit to control the actuator the pump used must have at least two high pressure port, which increases the cost. At same time due to there is gap area between the two cavities of the hydraulic cylinder of the actuator the differential cylinder gap area compensate circuit to ensure the normal performance of the hydraulic cylinder of the actuator, which increases the throttle loss and the cost. When the actuator needs big power output the drive motor is not able to satisfy the requirement.
SUMMARY OF THE PRESENT INVENTION
[0006] An object of the present invention is to provide a variable-speed volume-control direct-drive all-electric hydraulic excavator drive and energy recovery system to solve the problems the conventional all-electric drive hydraulic excavator has, which adopts an open type control circuit, wherein each of the two cavities of the hydraulic cylinder is controlled by a energy source; the pressure and flow rate of every cavity is able to be adjusted independently by the control of the rotational speed and torque of the motor. The present invention is adapted to all kinds of asymmetry characters of the system and is four-quadrant running.
[0007] Accordingly, in order to accomplish the above object, the present invention provides a variable-speed volume-control direct-drive all-electric hydraulic excavator drive and energy recovery system, comprising: a boom hydraulic cylinder, an arm hydraulic cylinder, a bucket hydraulic cylinder, a swing motor, a left travel motor, a right travel motor, a mutual DC bus, a main switch, a rectifier, a smooth capacitor, a DC-DC converter, and a storage battery, wherein a drive control circuit is also included, comprising: an A energy source, a B energy source, a C energy source, a boom cylinder control valve group, an arm cylinder control valve, a swing motor control valve group, a bucket control valve, a swing control valve, a swing motor control valve group, a left travel control valve, a right travel control valve, a I-VIII 2-position 2-way valve, a I and II 2-position 3-way valve, a I and II accumulator; wherein the A, B, and C, energy source comprises a hydraulic pump, a motor generator, an inverter, an input of the inverter is connected with the mutual DC bus, an output of the inverter is connected with a motor generator driven by the inverter, the motor generator is connected with the hydraulic pump driven by the motor generator; wherein the control valve group of the boom cylinder, the arm cylinder and swing motor comprises A, B, C, D 2-position 2-way valve, wherein one of ports of A, D 2-position 2-way valve is connected to an oil tank respectively; the other port of A, D 2-position 2-way valve is connected to a first port of the B 2-position 2-way valve and C 2-position 2-way valve respectively; a second port of the B 2-position 2-way valve and C 2-position 2-way valve are connected together; an oil passage is drawn from a piping between the A and B 2-position 2-way valve to be connected with a rod cavity of the boom hydraulic cylinder, a rod cavity of arm hydraulic cylinder and a first port of the swing motor; wherein an oil passage is drawn from a piping between the C and D 2-position 2-way valve to be connected with a rodless cavity of the boom hydraulic cylinder, a rodless cavity of the arm hydraulic cylinder and a second port of the swing motor.
[0008] A first working port of the hydraulic pump of the A energy source is connected with a first port of the I 2-position 3-way valve; a second port and a third port are connected with the I accumulator and the tank respectively; a second working port of the hydraulic pump of A energy source is connected with a first port of the left travel control valve, a first port of the bucket control valve, a piping between the B 2-position 2-way valve and C 2-position 2-way valve of the boom cylinder control valve group, a first port of the IV 2-position 2-way valve and a first port of the V 2-position 2-way valve.
[0009] An inlet port of the hydraulic pump of the B energy source is connected with the tank, an oil outlet of which is connected with a second port of the V 2-position 2-way valve; wherein an oil outlet of the hydraulic pump of the B energy source is connected with a piping between the B and C 2-position 2-way valve of the bucket control valve group and swing motor control valve group respectively, a first port of the right travel control valve, and a first port of the VI 2-position 2-way valve; the oil outlet of the hydraulic pump of the B energy source is connected with the II accumulator through the VII 2-position 2-way valve.
[0010] A first working port of the hydraulic pump of the C energy source is connected with a first port of the II 2-position 3-way valve, wherein a second and a third port is connected with the II accumulator and the tank; a second working port of the hydraulic pump of the C energy source is connected with a second port of VI 2-position 2-way valve, a second port of the I and II 2-position 2-way valve, and a first port of swing control valve; wherein a second working port of the hydraulic pump of the C energy source is connected with the II accumulator and a second working port of the hydraulic pump of the A energy source through the VIII 2-position 2-way valve and the IV 2-position 2-way valve; a first port of the I 2-position 2-way valve and the II 2-position 2-way valve are connected with the rod cavity of the boom hydraulic cylinder and the arm hydraulic cylinder respectively.
[0011] A second and a third port of the swing control valve are connected with two ports of the swing motor respectively; working ports of the left travel motor and the right travel motor are connected with the left travel control valve and right travel control valve respectively; a first working port of the III 2-position 2-way valve is connected with the rodless cavity of the arm hydraulic cylinder; a second working port of the III 2-position 2-way valve is connected with a first working port of the II 2-position 2-way valve.
[0012] The control circuits of the boom hydraulic cylinder, arm hydraulic cylinder and swing motor are all independent-cavity variable-speed pump-control volume direct-drive circuit; the A energy source feeds oil to the left travel motor, the bucket hydraulic cylinder and boom hydraulic cylinder; the B energy source feeds oil to the arm hydraulic cylinder, the swing motor and the right travel motor; the C energy source feeds oil to the left travel motor, bucket hydraulic cylinder, boom hydraulic cylinder, arm hydraulic cylinder, swing motor and right travel motor by on/off control of the IV, V and VI 2-position 2-way valve.
[0013] A redundancy control of the A, B and C energy source is that the rod cavity and rodless cavity of the boom hydraulic cylinder is controlled by the A energy source or the C energy source or the combination of the A and C energy source and the B energy source or the C energy source or the combination of the B and C energy source respectively, the rod cavity and rodless cavity of the arm hydraulic cylinder is controlled by the B energy source or the C energy source or the combination of the B and C energy source and the B energy source or the C energy source or the combination of the B and C energy source respectively, and the oil is able to pass through the rod cavity and rodless cavity of the arm hydraulic cylinder by the on/off control of the III 2-position 2-way valve.
[0014] Control circuits of the boom hydraulic cylinder, arm hydraulic cylinder and swing motor are active and passive composite energy recovery circuit, wherein when the pressure inside the I and II accumulator is lower than the pre-set minimal value the potential energy of the boom hydraulic cylinder and arm hydraulic cylinder and the kinetic energy of the swing motor braking is stored in the I or II accumulator by connecting the IV-VIII 2-position 2-way valve; when the pressure inside the I and II accumulator is higher than the pre-set maximum value the potential energy of the boom hydraulic cylinder and arm hydraulic cylinder and the kinetic energy of the swing motor braking is stored in the mutual DC bus as electric energy transferred by the motor generator; the energy storage in the I or II accumulator and mutual DC bus is able to be carried out simultaneously; wherein the passage and transfer of system energy between the accumulator, mutual DC bus and motor generator is able to drive a load by control the A, B and C energy source.
[0015] A redundancy control of the energy recovery of the A, B and C energy source is when the motor generator is recover the energy as a generator the A, B and C energy source is able to work separately or in combination to recover the potential energy of the boom hydraulic cylinder and arm hydraulic cylinder and the kinetic energy of the swing motor braking.
[0016] The hydraulic pumps of the A, B, C energy source are a fixed hydraulic pump or different kinds of variable hydraulic pump; the motor generators of the A, B and C energy source are a permanent magnet synchronous generator or a asynchronous AC generator or a switched reluctance generator.
[0017] The A, B, C and D 2-position 2-way valve of the boom cylinder control valve group, arm cylinder control valve group and swing motor control valve group, the bucket control valve, swing control valve, left travel control valve, right travel control valve, the 2-position 2-way valve the I and II 2-position 3-way valve is electromagnetic switched valve and electric proportional valve or a valve group of cartridge valve.
[0018] The A, B, C and D 2-position 2-way valve of the boom cylinder control valve group, arm cylinder control valve group and swing motor control valve group are replaceable by a combination of 3-position 3-way valves which with a same function.
[0019] The present invention has the below benefits:
1) The system is four-quadrant running: each of the two cavities of cylinder is controlled by an energy source respectively and the pressure and flow rate of the cavities are adjusted by the rotational speed and torque control of the generator independently, which is adapted to all kinds of asymmetry characters of the system and is four-quadrant running and satisfies the requirements of all kinds of loads. 2) High efficiency: the present invention adopts the theory of distribution variable-speed pump independent inlet and outlet port direct-drive differential cylinder circuit and the control technology of active and passive composite swing, which is able to eliminate throttle loss. Compared to the collective energy source drive variable pump, every motor and fixed hydraulic pump works within the high efficiency zone, which improves the overall efficiency significantly. 3) High integrity: the layout overall control plan of the present invention is flexible, convenient, highly integrated, and free of the limitation by space. 4) Low consumption: the overall control plan of the present invention reduces the installing power and the system heating and increases the sustainable working time while reducing the cooling power, which solve the problem of hydraulic oil heating and aging due to small hydraulic oil tank of the engineering machinery. 5) Energy source redundancy: the overall control plan of the present invention has redundancy function which is able to shut off the mal-function energy source and ensures the stable performance of the actuator while the energy source failure. 6) The control plan of the present invention adopts open type working while remains the advantages of the closed circuit, which has many advantages such as no need for pilot supply, low noise, integrate recovery of kinetic energy and potential energy etc. and makes up the disadvantages of the closed control.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIG. 1 illustrates a system of the present invention;
[0027] FIG. 2 is an assembly of a boom cylinder control valve group, arm cylinder control valve group and swing motor control valve group of the present invention;
[0028] FIG. 3 illustrates a servo system circuit of independent-cavity variable-speed volume direct-drive differential cylinder of the present invention;
[0029] FIG. 4 illustrates the active and passive composite energy recovery circuit.
[0030] Element reference: 1 —boom hydraulic cylinder 1 —arm hydraulic cylinder, 3 —bucket hydraulic cylinder, 4 —swing motor, 5 —left travel motor, 6 —right travel motor, 7 —mutual DC bus, 8 —main switch, 9 —rectifier, 10 —smooth capacitor, 11 —DC-DC converter, 12 —storage battery, 13 —A energy source, 14 —B energy source, 15 —C energy source, 16 —boom cylinder control valve group, 17 —arm cylinder control valve, 18 —swing motor control valve group, 20 —bucket control valve, 21 —swing control valve, 22 —left travel control valve, 23 —right travel control valve, 24 ˜ 31 —I-VIII 2-position 2-way valve, 32 —I 2-position 3-way valve, 33 —II 2-position 3-way valve, 34 —I accumulator, 35 —II accumulator, 38 —inverter, 39 —motor generator, 40 —hydraulic pump, 41 —actuator, 42 —motor controller, 43 —control system.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0031] Referring to FIG. 1 to FIG. 4 of the drawings, according to a preferred embodiment of the present invention is illustrated, wherein as illustrated in FIG. 1 a variable-speed volume-control direct-drive all-electric hydraulic excavator drive and energy recovery system, comprising: a boom hydraulic cylinder 1 , an arm hydraulic cylinder 2 , a bucket hydraulic cylinder 3 , a swing motor 4 , a left travel motor 5 , a right travel motor 6 , a mutual DC bus 7 , a main switch 8 , a rectifier 9 , a smooth capacitor 10 , DC-DC converter 11 , and a storage battery 12 , wherein a drive control circuit is also included, comprising: an A energy source 13 , a B energy source 14 , a C energy source 15 , a boom cylinder control valve group 16 , an arm cylinder control valve 17 , a swing motor control valve group 18 , a bucket control valve 20 , a swing control valve 21 , a left travel control valve 22 , a right travel control valve 23 , I-VIII 2-position 2-way valves 24 ˜ 31 , I and II 2-position 3-way valves 32 , 33 , I and II accumulators 34 , 35 ; wherein each of the A, B and C energy source comprises a hydraulic pump 40 , a motor generator 39 , an inverter 38 , an input of the inverter is connected to the mutual DC bus, an output of the inverter is connected to a motor generator driving the inverter, the motor generator is connected with the hydraulic pump driven by the motor generator.
[0032] As illustrated in FIG. 1 and FIG. 2 the control valve group of the boom cylinder, the arm cylinder and swing motor comprises A, B, C, D 2-position 2-way valve, wherein the first ports of A, D 2-position 2-way valve are connected to an oil tank respectively; the second ports of A, D 2-position 2-way valve are connected to the first port of B 2-position 2-way valve and the first port of the C 2-position 2-way valve respectively; the second port of the B 2-position 2-way valve and the second port of the C 2-position 2-way valve are connected together; a oil passage is drawn from a piping between the A and the B 2-position 2-way valve to be connected with a rod cavity of the boom hydraulic cylinder, a rod cavity of the arm hydraulic cylinder and a first port of the swing motor; wherein another oil passage is drawn from a piping between the C and the D 2-position 2-way valve to be connected with a rodless cavity of the boom hydraulic cylinder, a rodless cavity of the arm hydraulic cylinder and a second port of the swing motor.
[0033] A first working port of the hydraulic pump of the A energy source is connected with a first port of the I 2-position 3-way valve; a second and a third port of the I 2-position 3-way valve are connected with the I accumulator and the tank respectively; a second working port of the hydraulic pump of the A energy source is connected with a first port of the left travel control valve, a first port of the bucket control valve, a piping between the B 2-position 2-way valve and the C 2-position 2-way valve of the boom cylinder control valve group, a first port of the IV 2-position 2-way valve and a first port of the V 2-position 2-way valve.
[0034] An inlet port of the hydraulic pump of the B energy source is connected with the tank, an outlet of which is connected with a second port of the V 2-position 2-way valve; wherein an outlet of the hydraulic pump of the B energy source is connected with a piping between the B and C 2-position 2-way valve of the bucket control valve group and swing motor control valve group respectively, a first port of the right travel control valve, and a first port of the VI 2-position 2-way valve; the outlet of the hydraulic pump of the B energy source is connected with the II accumulator through the VII 2-position 2-way valve.
[0035] A first working port of the hydraulic pump of the C energy source is connected with a first port of the II 2-position 3-way valve, wherein a second and a third port is connected with the II accumulator and the tank respectively; a second working port of the hydraulic pump of the C energy source is connected with a second port of VI 2-position 2-way valve, a second port of the I and II 2-position 2-way valve, and a first port of swing control valve; wherein a second working port of the hydraulic pump of the C energy source is connected with the II accumulator and a second working port of the hydraulic pump of the A energy source through the VIII 2-position 2-way valve and the IV 2-position 2-way valve respectively; a first port of the I 2-position 2-way valve and the II 2-position 2-way valve are connected with the rod cavity of the boom hydraulic cylinder and the arm hydraulic cylinder respectively.
[0036] A second and a third port of the swing control valve are connected with two ports of the swing motor respectively; working ports of the left travel motor and the right travel motor are connected with the left travel control valve and right travel control valve respectively; a first working port of the III 2-position 2-way valve is connected with the rodless cavity of the arm hydraulic cylinder; a second working port of the III 2-position 2-way valve is connected with a first working port of the II 2-position 2-way valve.
[0037] Control circuits of the boom hydraulic cylinder, arm hydraulic cylinder and swing motor are all independent-cavity variable-speed pump-control volume direct-drive circuit; the A energy source feeds oil to the left travel motor, the bucket hydraulic cylinder and boom hydraulic cylinder; the B energy source feeds oil to the arm hydraulic cylinder, the swing motor and the right travel motor; the C energy source feeds oil to the left travel motor, bucket hydraulic cylinder, boom hydraulic cylinder, arm hydraulic cylinder, swing motor and right travel motor by on/off control of the IV, V and VI 2-position 2-way valve.
[0038] A redundancy control of the A, B and C energy source is that the rod cavity and rodless cavity of the boom hydraulic cylinder is controlled by the A energy source or the C energy source or the combination of the A and C energy source and the B energy source or the C energy source or the combination of the B and C energy source respectively, the rod cavity and rodless cavity of the arm hydraulic cylinder is controlled by the B energy source or the C energy source or the combination of the B and C energy source and the B energy source or the C energy source or the combination of the B and C energy source respectively, and the oil is able to pass through the rod cavity and rodless cavity of the arm hydraulic cylinder by the on/off control of the III 2-position 2-way valve.
[0039] As illustrated in FIG. 3 the theory for independent-cavity variable-speed pump-control volume direct-drive circuit to drive the boom, arm and swing motor is that the actuator 41 may be the boom hydraulic cylinder or arm hydraulic cylinder, or the swing motor. The actuator drives load M. The rod cavity and rodless cavity of the boom hydraulic cylinder or the arm hydraulic cylinder, and the two ports of the swing motor are controlled and driven by A energy source 13 and B energy source 14 . The A, B energy source is able to feed oil to the two cavities of the hydraulic cylinder or the two ports of the swing motor independently or together according to the requirement of the load by on/off control of the I 2-position 2-way valve 24 and the V 2-position 2-way valve 28 . For example when the A energy source feed oil independently, the B and D 2-position 2-way valve of the boom cylinder control valve group (or the arm cylinder control valve group or the swing motor control valve) is in on-state. The A energy source input the oil to the rodless cavity of the actuator through the B 2-position 2-way valve of the boom cylinder control valve group (or the arm cylinder control valve group or the swing motor control valve). The oil in the rod cavity flows back to the tank through the D 2-position 2-way valve of the boom cylinder control valve group (or the arm cylinder control valve group or the swing motor control valve). When the A and B energy source feed the oil together, the V 2-position 2-way valve 28 is in on-state. The A and B energy source input the oil to the rodless cavity of the actuator. The oil in the rod cavity flows back to the tank through the D 2-position 2-way valve of the boom cylinder control valve group (or the arm cylinder control valve group or the swing motor control valve). The A and B energy source are both connected with the mutual DC bus. As illustrated in FIG. 3 the rod cavity and rodless cavity of the hydraulic cylinder or the two ports of the swing motor are controlled independently, the pressure and flow rate of all the cavities of the actuator are able to be adjusted separately by controlling the rotational speed and torque of the motor, which meets the requirements of all kinds of system with asymmetry character and realize four-quadrant running.
[0040] The theory illustrated in FIG. 3 is applied to hydraulic excavator. The boom hydraulic cylinder, arm hydraulic cylinder, swing motor, left travel motor, right travel motor and bucket hydraulic cylinder are driven by A, B and C energy source. Under normal state, wherein the A energy source feeds oil to the left travel motor, the bucket hydraulic cylinder and the boom hydraulic cylinder; the B energy source feeds oil to the arm hydraulic cylinder, the swing motor and the right travel motor; when strong driven force is needed by the load, C energy source feeds oil to the actuator as a complement according to the requirements by on/off control of the IV 2-position 2-way valve 27 , the V 2-position 2-way valve 28 and the VI 2-position 2-way valve 29 ; the rod cavity and to rodless cavity of the boom hydraulic cylinder and arm hydraulic cylinder and two working ports of the swing motor are controlled by two energy source respectively. The distributed A, B and C energy source are all connected with the mutual DC bus. The control valves in the circuit make the A, B and C energy source to be redundant system to each other. The A, B and C energy source is able to drive the actuator independently or in arbitrary combination, which makes the actuators act separately or in combination. If any of the three energy sources fail to work, the mal-function energy source is able to be separated by the control valves in the circuit and the normal working energy source will be set in working mode. The system is able to working normally if there is energy source malfunction.
[0041] As illustrated in FIG. 1 , the variable-speed volume-control direct-drive all-electric hydraulic excavator drive system has energy recovery function which constitutes independent-cavity variable-speed volume-control all-electric hydraulic excavator energy recovery system. The control circuits of the boom hydraulic cylinder, arm hydraulic cylinder and swing motor are active and passive composite energy recovery circuit, wherein when the pressure inside the I and II accumulator is lower than the pre-set minimal value the potential energy of the boom hydraulic cylinder and arm hydraulic cylinder and the kinetic energy of the swing motor braking is stored in the I or II accumulator by connecting the IV-VIII 2-position 2-way valve; when the pressure inside the I and II accumulator is higher than the pre-set maximum value the potential energy of the boom hydraulic cylinder and arm hydraulic cylinder and the kinetic energy of the swing motor braking is stored in the mutual DC bus as electric energy transferred by the motor generator; the energy storage in the I or II accumulator and mutual DC bus is able to be carried out simultaneously; wherein the system energy is past and transfered between the accumulator, the mutual DC bus and the motor generator, which is able to drive a load by control the A, the B and the C energy source
[0042] A redundancy control of the energy recovery of the A, B and C energy source is when the motor generator is recover the energy as a generator the A, B and C energy source is able to work separately or in combination to recover the potential energy of the boom hydraulic cylinder and arm hydraulic cylinder and the kinetic energy of the swing motor braking.
[0043] The theory of active and passive composite energy recovery circuit for recovering the potential energy of the boom and arm hydraulic cylinder and the kinetic energy of swing motor braking is illustrated in FIG. 4 . The actuator 41 may be the boom hydraulic cylinder or arm hydraulic cylinder or the swing motor, which drives the load M. The A energy source 13 and the B energy source 14 both comprises motor controller 42 , motor generator 39 and hydraulic pump 38 . The input terminal of the motor controller is connected with the control system 43 and the output terminal of the motor controller is connected with motor generator driven by the motor controller. The motor generator is connected with the hydraulic pump driven by the motor generator.
[0044] For example when the actuator is the swing motor and the active circuit is the drive circuit. A and B energy source feed oil to the two ports of the swing motor independently or together according to the load requirements by on/off control of the swing motor control valve group and the swing control valve. The passive circuit is energy recovery circuit. By on/off control of the swing control valve and the VIII 2-position 2-way valve 31 , the motor braking kinetic energy is stored in the II accumulator 35 . All the control valves, A energy source and B energy source is controlled by the control system 43 . The energy stored in the accumulator II is able to be released as auxiliary drive for the system.
[0045] The active and passive composite swing drive theory illustrated in FIG. 4 is applied to hydraulic excavator. The A, B and C energy source drive the actuators, all three of which is connected with the mutual DC bus and constitute the independent-cavity variable-speed volume direct-drive all-electric hydraulic excavator energy recovery system. The A, B and C energy source is able to drive the boom hydraulic cylinder, the arm hydraulic cylinder, the swing motor, the left travel motor, the right travel motor and the bucket hydraulic cylinder while the potential energy of the boom hydraulic cylinder and arm hydraulic cylinder and the kinetic energy of the swing motor braking are able to be recovered. When the pressure inside the I and II accumulator is low, the potential energy of the boom hydraulic cylinder and arm hydraulic cylinder and the kinetic energy of the swing motor braking are able to be stored in the I or II accumulator by connecting the IV-VIII 2-position 2-way valve. When the pressure inside the I and II accumulator is too high to store energy, the potential energy of the boom hydraulic cylinder and arm hydraulic cylinder and the kinetic energy of the swing motor braking are able to be stored in the mutual DC bus as electric energy transferred by the motor generator.
[0046] The motor generator is able to work as a motor and a generator according to the different requirement of the load. The motor generator works as a motor when drive the load and a generator when recovery the energy. The system energy is passed and transferred among the accumulator, mutual DC bus and motor generator without the need to add specific energy storage components.
[0047] The hydraulic pumps of the A, B, and C energy source are fixed hydraulic pumps or different kinds of variable hydraulic pumps; the motor generators of the A, B and C energy source are permanent magnet synchronous generators or asynchronous AC generators or switched reluctance generators.
[0048] The A, B, C and D 2-position 2-way valve of the boom cylinder control valve group, arm cylinder control valve group and swing motor control valve group, the bucket control valve, swing control valve, left travel control valve, right travel control valve, the I-VIII 2-position 2-way valve the I and II 2-position 3-way valve are electromagnetic switched valve and electric proportional valves or valve groups of cartridge valves.
[0049] The A, B, C and D 2-position 2-way valve of the boom cylinder control valve group, arm cylinder control valve group and swing motor control valve group are replaceable by a combination of 3-position 3-way valves with a same function.
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A variable-speed volume-control direct-drive all-electric hydraulic excavator drive and energy recover system the control drive circuit of which includes the A, B, C energy source, boom cylinder control valve group, arm cylinder control valve group, bucket control valve, swing control valve, swing motor control valve group, left travel control valve, right travel control valve, eight 2-position 2-way valve, I and II 2-position 3-way valve, I and II accumulator. The drive control circuit adopts open control independent-cavity variable-speed pump-control volume direct-drive circuit. Each of the cavities of cylinder is controlled by an energy source and the pressure and flow rate of the cavities are adjusted by the rotational speed and torque control of the generator independently. The present invention is four-quadrant running and have advantages of high efficiency, high integrity, low consumption, redundancy energy source, no need for pilot supply, low noise, integrate recovery of kinetic and potential energy.
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FIELD AND BACKGROUND OF THE INVENTION
The invention relates to a control arrangement, in particular a power-control arrangement for a vehicle engine, having a movable actuating lever, particular a pedal, and a damping device which counteracts movement of the actuating lever. In order to give the operator of such a control arrangement a perceptible indication of force along the displacement of the actuation lever for example, a gas pedal) and to avoid excessive vibration of the arrangement, damping, e.g. by frictional elements, is also provided in addition to a restoring force--usually displayed by a restoring spring. Naturally, such damping is usually the same in both directions of movement, that is to say counter to the restoring force as well. On account of aging, wear or the like, the damping can become excessive, with the result that the control arrangement is only restored slowly or, in the extreme case, not at all.
A damping or braking hysteresis has therefore already been provided between the two directions of movement. One embodiment is described in DE 34 12 318 A1. In this document, frictional elements which can be moved in a translatory manner are subjected to the action of a restoring spring. When the pedal is pressed down, they are pressed against their mating frictional surfaces increasingly the more the spring is stressed, whereas when the movement is reversed the contact-pressure force, and thus the action of friction, are reduced as relaxation of the spring increases. With this arrangement, however, it would be possible for the pairs of frictional elements to wedge against one another as spring force increases.
In another known method of frictional damping for a gas pedal (DE 195 17 172 A1), the pedal-restoring spring is arranged between the pedal itself and a rocker-type braking lever. The latter presses a friction lining onto a rotary bearing sleeve of the pedal lever. The contact-pressure force of the friction lining increases proportionally as the pedal is pressed down further, and decreases correspondingly again when the pedal is released. At the moment the pedal is released (turning point), however, the maximum friction force is still effective temporarily.
In one relevant arrangement with hydraulic displacement transmission (DE 25 50 326 A1) from a pedal-side master cylinder to a control-side slave cylinder, there is a stronger restoring spring on the slave cylinder than on the master cylinder, with the result that the slave cylinder cannot trail when the pedal is relieved of loading. Damping of this arrangement is ensured by the unavoidable flow resistances between the master and slave cylinders; on the other hand, there is no force hysteresis between the pedal being loaded and relieved of loading.
SUMMARY OF THE INVENTION
The object of the invention is to improve the functional reliability of the damping of such a control arrangement.
According to the invention a freewheel is provided which at least reduces the damping force which acts on the actuating lever, in one direction of movement of the actuating lever.
If a freewheel, which is active in the direction in which the pedal is relieved of loading or restored, is provided between the pedal support and the frictional element coupled to the pedal, the movement damping only acts when the pedal is pressed down, while it is at least significantly reduced, or rendered totally ineffective, by the freewheel when the pedal is released. With sufficient damping of pedal vibration, this ensures a spontaneous reaction of the controlled variable--e.g. engine power--to the release of the actuating lever.
This measure also changes the mutual weighting of the restoring force and damping force, because, in combination with a restoring freewheel, the restoring force can be rendered weaker than in previous applications, in which, in addition to the mass of the actuating lever and, if appropriate, bearing-point friction, the restoring force also had to overcome the additional damping force. In contrast, the damping or hysteresis can be enhanced because it no longer has an effect on the restoring movement.
In a rotary frictional arrangement, the pedal-side frictional body, in the same way as in a ratchet, can only be rotated further in one direction, namely when the pedal is pressed down, counter to the friction force, while the frictional body remains in the same position when the pedal is restored. An advantageous secondary effect of this is that, overall, the frictional surface of the frictional body wears to a lesser extent, and uniformly, over its circumference.
A particularly advantageous design of a mechanical freewheel with an extremely small space requirement is a sleeve-type freewheel (e.g. of INA HF 1012 design type produced by a company INA of Herzogenaurach in Germany) which is known per se and is externally constructed like a needle bearing, although its bearing needles act as clamping rollers, and have a locking action, in one direction of rotation.
Depending on the installation conditions, however, it is also possible for other types of freewheels to be used. The important factor in each case is that by the freewheel freedom of movement is provided between the actuating lever or pedal and the damping device such that the damping force does not act counter to the force of the restoring spring or at least from the start has vastly diminished action counter to the force of the restoring spring.
If the damping device acts fluidically/hydraulically (e.g. flow through at least one throttle bore in a piston sliding between two operating chambers), then it is possible to provide therein a freewheel or at least a reduced damping force in one direction of movement by a bypass parallel to the throttle bore, which in a manner known per se, and pressure-controlled by a nonreturn valve (flutter valve), is automatically closed when the actuating lever is loaded, and opened when said lever is relieved of loading, in order to release an enlarged overflow cross section.
The freewheel may also be realized in that, when the actuating lever is relieved of loading, the friction lining is mechanically raised from its frictional surface automatically, following minimal return travel, in order to cancel the friction fit. Such an arrangement could also be provided in a frictional-damping arrangement with translatory relative movement.
BRIEF DESCRIPTION OF THE DRAWING
With the above and other objects and other advantages in view, the present invention will become more clearly understood in connection with basic representations for illustrating arrangements and action of the freewheel as well as the detailed description of preferred embodiments, when considered with the accompanying drawing of which
FIG. 1 shows a first embodiment with frictional damping and a mechanical freewheel,
FIG. 2 shows a second embodiment with fluidic damping and a restoring bypass, and
FIG. 3 shows a third embodiment with a device for canceling frictional damping when the actuating lever is restored.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
According to FIG. 1, an actuating lever 1 is mounted such that it can be pivoted back and forth about a spindle 2A at a bearing point 2. The actuating lever (e.g. a gas pedal of a motor vehicle) is designed with two arms in this case. An actuating force 3, which is represented by a downwardly oriented arrow on the first (right-hand) arm of the lever, pivots said lever in the clockwise direction counter to the force of a restoring spring 4. The latter is supported--in a manner known per se--in a floating manner between the second (left-hand) arm of the actuating lever 1 and a first (left-hand) arm of a likewise two-armed braking lever 5. The braking lever is, in turn, mounted pivotably at a bearing point 6. A friction lining 7 is arranged on its other (right-hand) arm. The friction lining is pressed by the force of the spring, or the moment exerted about the bearing point 6 by the spring, onto the lateral surface of a cylindrical frictional body 8. The latter can be rotated about the same bearing point 2 as the actuating lever 1. The elements designated 5 to 8 are to be regarded overall as the damping device.
A sleeve-type freewheel 9 is arranged between the frictional body 8 and the spindle 2A of the actuating lever 1. The function of the freewheel is indicated by arrows: the spindle 2A of the actuating lever 1 can be pivoted in both directions, in the clockwise direction by the actuating force 3 and in the counterclockwise direction by the restoring spring 4, as is symbolized by a double arrow. In the clockwise direction, the sleeve-type freewheel 9 carries along the frictional body 8; this is thus its locking direction. This is illustrated by small arrow tips distributed over the circumference of the freewheel and by an arrow on the frictional body. In this case, the friction lining slides over the lateral surface of the frictional body 8.
If, in contrast, only the restoring spring acts, then the actuating lever 1 is guided back in the counterclockwise direction into its basic position, while the frictional body 8 runs freely with respect to the spindle 2A and is secured in its current position by the friction with the friction lining 7. As a result, with each actuation of the actuating lever 1 by a force 3, the frictional body 8 is rotated further by an angle corresponding to the pivot angle of said lever, and thus rotates in steps in the clockwise direction about the spindle 2A.
When the actuating lever 1, designed as a pedal, is pressed down, the friction-damped indication, or force on the foot, which has hitherto been usual in such arrangements is thus maintained. In contrast, when the foot is raised or withdrawn, the pedal follows on without delay as a result of the freewheel. If required, the freewheel itself could be damped slightly in order to avoid rebound of the actuating lever when the latter is suddenly relieved of loading.
It is merely for the sake of simplicity that the power-control elements arranged downstream of the actuating lever are not illustrated, these elements being, for example, an angle or displacement pickup for converting the respective pivot angle into a corresponding electric signal, and the associated evaluating and control means.
In the exemplary embodiment according to FIG. 2, the same parts are designated by the same designations as in FIG. 1. Instead of the friction damping, however, in this case a fluidic damper 10 is supported, parallel to the restoring spring 4, between the left-hand arm of the actuating lever 1 and a fixed support 6'. The function--known per se--of the damper is illustrated schematically: a piston 11 is guided in a sliding manner in a cylinder 12 and subdivides the latter into two chambers 13 and 14. The piston 11 has a throttle bore 15 which, with each movement of the piston 11, permits damped pressure and volume equalization between the chambers. A bypass bore 16 is provided parallel to the throttle bore 15. When the piston 11 is moved upward, said bypass bore is closed off by a nonreturn or flutter valve 17 as a result of the increased pressure in the chamber 13, with the result that volume equalization takes place merely, or essentially, via the throttle bore 15. This is thus the (strongly) damped direction of movement of the actuating lever 1. When the lever is restored by the spring 4, the pressure in the bottom chamber 14 increases straight away and opens the flutter valve acting with bypass bore 16 as a freewheel, with the result that quicker pressure equalization can take place via the bypass. This is thus the freewheeling direction, even if slight damping is maintained. However, as has already been mentioned, this damping may actually be utilized in order to prevent a gas pedal from springing back suddenly. In relation to the restoring spring, the damping will have to be such that the pedal follows withdrawal of the foot without delay.
A gas (e.g. air) or else a suitable liquid can be used as flow medium for the damper 10. If gas is used, the sealing of the damper is not subject to any particular requirements; rather, the compression of the gas may advantageously contribute to increasing the effective restoring force.
In a third embodiment, shown in FIG. 3, with a mechanical freewheel 18, the restoring spring 4 is supported, analogously to FIG. 2, between the actuating lever 1 and a fixed support 6'. A fluidic damper 18 (basic illustration) with a piston rod on either side is arranged between the actuating lever 1 and the braking lever 5 according to FIG. 1, with the result that the fluid contained can be pumped back and forth via the throttle bore 19 of the piston 20, with complete volume equalization. The frictional body 8 is connected in a rotationally fixed manner to the actuating lever 1 without a freewheel.
In this embodiment, the braking lever 5 can only be pivoted, or subjected to loading, about its bearing point 6 by forces transmitted by the damper 18. Under the action of the actuating force 3, the piston 20 is pressed upward counter to the damping force. In relation to the bearing point 6, a pivot force then acts on the braking lever 5 in the clockwise direction. This pivot force presses the friction lining 7 onto the frictional body 8. When the arrangement is at a standstill, basically no friction force takes effect, nor is it needed.
When the actuating lever 1 is restored by the spring 4, the braking lever is pivoted in the counterclockwise direction by the tensile force which is transmitted temporarily in the damper 18 as a result of the throttled return flow. This means that the friction lining 7 is raised up from the frictional body 8, as indicated by dashed lines. This results in the abovementioned mechanical canceling of the friction fit, with the result that the actuating lever runs freely and/or can be restored without braking. The amount of travel of the friction lining 7 which is necessary for this purpose is very small.
The damper 18 is preferably made such that its piston is automatically prestressed into a central position--in this case indicated by the springs 21--in order to equalize, by damped restoring movements, differences in length caused by the pumping and to provide length stops on either side. This means that, even in the rest state, there may be a slight contact-pressure force between the friction lining and the frictional body, but that this force is reliably canceled at the moment when movement is reversed or the lever is relieved of loading.
Overall, the dampers, like the springs, may, of course, be designed such that they can reliably follow even the maximum movements of the actuating lever 1.
The basic illustrations discussed here are not provided as limitations of the structural elements of the control arrangement.
Thus, for example in the embodiment according to FIG. 2, a space-saving combination of the spring 4 and of the damper 10 will be preferred, it being possible for these to be designed coaxially as a spring leg, or the spring being installed in the damper, e.g. in the top operating chamber. If the damper 10 is operated with a fluid filling, then complete volume equalization or corresponding volume buffering of the differential action of the piston should be ensured.
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A control arrangement, in particular a power-control arrangement for engines of vehicles, having an actuating lever (1), in particular a pedal, and a damping device (5-8; 10) which counteracts a movement of the actuating lever (1), comprising a freewheel (9; 16, 17; 18) which at least reduces in one direction of movement the damping force which acts on the actuating lever.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to vehicle which are heavier than air, and more specifically to aircraft constructions involving multiple engines and wings.
2. Discussion of the Prior Art
Since the beginning of flight, aircraft constructions providing increased safety and reliability have been of particular interest. This is especially true with respect to the smaller private aircraft where many of the safety features available on larger aircraft have not been economically justifiable. Smaller aircraft which are designed to carry fewer passengers, have also suffered from the need to provide economy not only in the purchase of the aircraft but also in its operation and maintenance. Such configurations commonly include a single engine having a pull propeller at the nose of the aircraft. When this single engine has failed, an emergency landing, often with fatal consequences, has been required.
In some cases, a single engine has been disposed in the rear of the aircraft and provided with a push propeller. In either location, the single engine generates an undesirable reverse torque on the aircraft along the roll axis. This reverse torque has required the pilot to provide a counter torque in the flight characteristics of the aircraft.
Aircraft of the past have commonly included a fixed main wing disposed generally centrally of the aircraft, and a tail wing disposed at the rear of the aircraft. Vertical stabilizers have typically been positioned to extend upwardly from the tail wing. A forward wing, commonly referred to as a Canard wing, has also been provided to facilitate forward control of the aircraft. Often these three wings have been positioned in generally common planes so that the slip stream of one wing has tended to interfere with the control characteristics of the other wing.
Landing systems have commonly supported aircraft in a horizontal position with a nose wheel, and a pair of main wheels extending laterally from the fuselage. This type of landing structure is susceptible to tail drag particularly during take-off at an excessive angle. Forward engine aircraft have been provided with tail wheels mounted to the fuselage to avoid this contact between the tail and the ground. Unfortunately, rear engine aircraft include propellers which often extend beneath the fuselage. In such cases, tail wheels attached to the fuselage have not provided adequate protection for the aircraft.
SUMMARY OF THE INVENTION
In accordance with the present invention, a pair of engines are provided, one at the front of the aircraft and one at the rear of the aircraft. These engines torque the aircraft in opposite directions so there is substantially no roll torque to be corrected. These engines are disposed on different vertical axes so the tail propeller receives at least a portion of its air from outside the wash of the nose propeller.
A preferred embodiment of the invention includes a main wing disposed above the fuselage of the aircraft and a tail wing which is disposed below the main wing and forward of the tail propeller. Vertical stabilizers can be positioned along the tail wing and in a preferred embodiment directed downwardly to support a drag wheel. This is of particular interest to embodiments wherein the tail propeller is disposed at the furthest end of the aircraft.
In other embodiments, a Canard wing can be provided and disposed in a plane different from the planes associated with the main wing and the tail wing. This insures that each of the wings receives a generally undisturbed flow of air to facilitate its control characteristics. Ailerons associated with the Canard wing and the tail wing are operable in tandem to provide a high degree of control over the pitch characteristics of the aircraft. Also, by controlling the lift characteristics of the Canard wing relative to the tail wing, the stall characteristics of the aircraft can be adjusted so that the airplane automatically tends to dive from a stall condition.
All of these features add to the safety and reliability of the aircraft. They are easily accommodated in a small private aircraft as well as larger commercial aircraft.
These and other features and advantages of the invention will be more apparent with a description of preferred embodiments and reference to associated drawings.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of one embodiment of the aircraft construction associated with the present invention;
FIG. 2 is a top plan view of the embodiment illustrated in FIG. 1;
FIG. 3 is a bottom plan view of the aircraft illustrated in FIG. 1;
FIG. 4 is a side elevation view of the aircraft illustrated in FIG. 1;
FIG. 5 is a front elevation view of the aircraft illustrated in FIG. 1;
FIG. 6 is a side view of an embodiment including a downwardly extending vertical stabilizer and a drag wheel;
FIG. 7 is a top plan view of a further embodiment of the aircraft construction of the present invention;
FIG. 8 is a side elevation view of the aircraft illustrated in FIG. 7; and
FIG. 9 is a elevation view of the aircraft illustrated in FIG. 7.
DESCRIPTION OF PREFERRED EMBODIMENTS
An aircraft is illustrated in FIG. 1 and designated generally by the reference numeral 10. The aircraft includes a fuselage 12, a tail section 16, and a Canard wing 18. Although these wings 14-16 are referred to singularly, it will be understood that each of the wings includes a portion which extends to the left of the fuselage 12 and a portion which extends to the right of the fuselage. Thus the main wing 14 includes a left wing 14a and a right wing 14b.
A pair of engines 21 and 23, disposed in the front and rear of the aircraft respectively, are designed to counter rotate respective propellers 25 and 27 to provide a motive force for the aircraft. For example, the propeller 25 may be rotated counter clockwise (in the direction of arrow 30) to pull the aircraft, while the propeller 27 is rotated clockwise (in the direction of arrow 32) to push the aircraft. Landing gear 34 is provided of the type which maintains the fuselage 12 in a generally horizontal orientation.
As best illustrated in FIG. 4, the fuselage 12 will typically have an offset or S-shaped configuration with a nose section 41, central section 43 and tail section 45. The nose section 41 will typically house the engine 21 and support the wing 18 and propeller 25. Similarly, the tail section 45 will typically house the engine 23 and support the wing 16 and propeller 27. Between the nose section 41 and tail section 45, the central section 43 will typically include the center of gravity 47 and support the main wing 14. This central section 43 may also typically house the cockpit characterized by a windshield 50 and the passenger compartment characterized by the side windows 52.
In the illustrated embodiment, the nose section 41 extends generally forwardly from the bottom of the central section 43 while the tail section 45 extends generally rearwardly from the top of the central section 43. With this configuration both the axes 56 and 58 extend through the central section 43 which has the greatest vertical dimension, as illustrated in the side view of FIG. 4.
With reference to FIG. 4, it is apparent that the propeller 25 defines an axis 56 for the nose section 41 while the propeller 27 defines an axis 58 for the tail section 45. The effect of the rear propeller 27 is greatly increased if the air it receives is generally undisturbed. In a preferred embodiment this advantage is achieved by vertically offsetting the axes 56 and 58. This offset is easily accommodated in an embodiment wherein the fuselage 12 has the S-shape. In such an embodiment, the axis 56 can be aligned with the lower nose section 41 while the axis 58 is aligned with the higher tail section 45.
The highly desirable result is that this axis offset separates the wash associated with the respective propellers 25 and 27. Thus the wash associated with the forward propeller 25 has less affect on the rear propeller 27 than if the axes 56, 58 were aligned. This can be particularly appreciated with reference to FIG. 5 wherein the wash associated with the propeller 25 is represented by a dotted circle 61 and the wash associated with the propeller 27 is represented by a dotted circle 63. From FIG. 5 it is also apparent that the aircraft 10 is generally symmetrical about a vertical plane 59 which includes the axes 56 and 58.
This view also illustrating the vertically offset relationship of the respective wings 14, 16, and 18. In this particular embodiment, the main wing 14 is positioned over the fuselage 12. In this location the wing 14 is disposed above the windows 52 so the passengers have a better view of the ground. The Canard wing 18 is disposed generally beneath the fuselage 12. In this position, the wing 18 is disposed beneath the engine 21 and provides additional support for its weight.
It is desirable that the three wings 14, 16 and 18 be disposed in three separate generally horizontal planes in order that each wing might be disposed out of the slip stream associated with the other wings. In this particular embodiment it is desirable for the tail wing 16 is disposed in a horizontal plane between the main wing 14 and the Canard wing 18. As was the case with the Canard wing 18, it is also desirable for the tail wing 16 to be disposed beneath the engine 23 for the added support. Both of these advantages can be achieved with the S-shaped fuselage 12 which permits the tail wing 16 to be elevated from the Canard wing 18 and still positioned beneath the engine 23.
In the illustrated embodiment, roll stabilization is provided by a pair of vertical stabilizers 65, 67 which can extend transverse to the tail wing 16. In the illustrated embodiment, these stabilizers 65, 67 extend vertically upwardly from the tail wing 16. These stabilizers 65, 67 can be disposed generally anywhere along the tail wing 16 from the fuselage 12 to the outer edges of the wing 16. In the FIG. 5 embodiment, the stabilizers 65 and 67 are disposed generally intermediate the respective portions of the wing 16. The front view of FIG. 5 also best illustrated a preferred embodiment of the landing gear 34 which includes a nose wheel 70 and a pair of main wheels 72 and 74.
With the rear propeller 27 providing the rearmost element of the aircraft 10, it may be somewhat susceptible to damage during take-off at excessive angles. Under these circumstances, it would be desirable to provide a drag wheel for protecting the rear propeller 27. In the embodiment illustrated in FIG. 6, wherein the ground is designated by the reference numeral 75, the vertical stabilizers 65 and 67 are positioned to extend downwardly from the tail wing 16. At this extended downward position, the stabilizers 65 and 67 provide excellent supports for a pair of drag wheels 76 and 78, respectively. In this location the drag wheels 76, 78 would contact the ground thereby protecting the propeller 27 during take-off at excessive angles.
A further embodiment of the invention is illustrated in FIGS. 7-9 and includes elements which are similar to those previously discussed. These elements are designated by the same reference numeral followed by the lower case letter "a". Thus in FIG. 7 it can be seen that the aircraft includes the fuselage 12a, main wing 14a and tail wing 16a. Also illustrated in FIG. 7 are the forward engine 21a, rear engine 23a and associated propellers 25a and 27a, respectively. This particular aircraft construction is intended to carry fewer passengers and therefore may not benefit as much from a third wing, such as the Canard wing 18. Nevertheless, the aircraft advantageously includes the two engines 23a and 25a which are vertically offset by the accommodation of a S-shaped fuselage best illustrated in FIG. 8. In this embodiment, the main wing 14a may be advantageously located beneath the fuselage 12a in the central section 43a, with both the main wing 14a and the tail wing 16a positioned beneath the center of gravity 47a.
The three wing embodiment of the present invention offers further advantages in the control of the aircraft. As best illustrated in FIG. 2, the Canard wing 18 includes ailerons 85 while the tail wing 16 includes ailerons 87. In this particular embodiment, the ailerons 85, 87 can be mechanically coupled to operate simultaneously from a single aileron control in the cockpit. Thus, to produce an upward pitch in the aircraft 10, the ailerons 85 of the Canard wing 18 would pivot downwardly while the ailerons 87 of the tail wing 16 would simultaneously pivot upwardly. Similarly, to produce a downward pitch on the aircraft, the ailerons 85 on the Canard wing 18 would pivot upwardly while the ailerons 87 on the tail wing 16 would simultaneously pivot downwardly. Thus, the pitch of both the nose section 41 and tail section 45 of the aircraft 10 would be simultaneously controllable from a single aileron control in the cockpit.
From the foregoing discussion it will be apparent that other embodiments of the concept can also benefit from the advantages previously discussed. For example, engines other than propeller driving engines could be used in a particular embodiment. Other shapes for the fuselage 12 could provide the desired vertical offset for the axes 56 and 58. Other transverse orientations of the vertical stabilizers 65, 67 relative to the tail wing 16 will also be apparent. Structure other than the vertical stabilizers 65, 67 may also be provided to support drag wheels at a sufficient downward location to prevent damage to the rear propeller 27 during take-off. The relative horizontal positions of the respective wings 14-18 may also be varied in a particular embodiment. For example, the Canard wing 18 may be disposed in a horizontal plane between the main wing 14 and the tail wing 16. Alternatively, the Canard wing might be disposed on top of the fuselage 12 with the main wing 14 positioned below the fuselage 12.
Given these wide variations, which are all within the scope of this concept, one is cautioned not to restrict the invention to the embodiments which have been specifically disclosed and illustrated, but rather encouraged to determine the scope of the invention only with reference to the following claims.
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An aircraft construction includes a fuselage, a first engine mounted on an axis extending through the fuselage for pulling the aircraft, and a second engine vertically offset from the first engine and mounted on an axis extending through the fuselage for pushing the aircraft. A main wing is disposed generally in a first plane and a tail wing is disposed generally in a second plane. A Canard wing may be disposed in a third plane different than the first plane and the second plane. Vertical stabilizers positioned to extend downwardly from the tail wing support drag wheels to protect the second engine during takeoff.
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This application is a divisional application Ser. No. 09/562,249 filed May 2, 2000, now U.S. Pat. No. 6,423,776.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to oxygen barrier polyamide compositions exhibiting high oxygen scavenging capability suitable for extended shelf-life packaging applications. The polyamide products are particularly suited for producing barrier packaging articles such as monolayer or multi-layer films, sheets, thermoformed containers and coinjection/coextrusion blow molded bottles comprising polyethylene terephthalate (ET), polyolefin or polycarbonate as structural layers. Such articles are useful in a variety of oxygen-sensitive food, beverage, pharmaceutical, and health care product packaging applications.
2. Description of the Related Art
It is well known in the art to provide polyamide based packaging articles such as films, bottles and containers, which are useful for food packaging. Many such articles are made of multiple layers of different plastics in order to achieve the desired barrier properties. For example, U.S. Pat. Nos. 5,055,355 and 5,547,765 teach laminates of polyamides and ethylene vinyl alcohol copolymers which have good oxygen barrier properties.
In order to enhance freshness preservation, it is standard practice to package food and other materials within laminated packaging material that generally includes a barrier layer, that is, a layer having a low permeability to oxygen.
The sheet material can be thin, in which event it is wrapped around the material being packaged, or it can be sufficiently thick that it forms a shaped container body. It is known to include an oxygen scavenger in sheet material. The oxygen scavenger reacts with oxygen that is trapped in the package or that permeates into the package. This is described, for instance, in U.S. Pat. Nos. 4,536,409 and 4,702,966. U.S. Pat. No. 4,536,409, for example, describes cylindrical containers formed from such sheet material.
Various types of oxygen scavengers have been proposed for this purpose. U.S. Pat. No. 4,536,409 recommends potassium sulfite as an oxygen scavenger. U.S. Pat. No. 5,211,875 discloses the use of unsaturated hydrocarbons as oxygen scavengers in packaging films. It is known in the art that ascorbic acid derivatives as well as sulfites, bisulfites, phenolics, etc. can be oxidized by molecular oxygen, and can thus serve as an oxygen scavenging material. U.S. Pat. No. 5,075,362 discloses the use of ascorbate compounds in containers as an oxygen scavengers. U.S. Pat. Nos. 5,202,052 and 5,364,555 describe polymeric material carriers containing oxygen scavenging material. These polymeric carriers for the oxygen scavenging material include polyolefin, PVC, polyurethanes, EVA and PET. U.S. Pat. Nos. 5,021,515, 5,049,624 and 5,639,815 disclose packaging materials and processes therefor which utilize a polymer composition which is capable of scavenging oxygen; such compositions include an oxidizable organic polymer component, preferably a polyamide (preferably MXD6) and a metal oxidation promoter (such as a cobalt compound). These compositions can be used with PET, for example.
U.S. Pat No. 5,529,833 describes the use a composition comprising an ethylenically unsaturated hydrocarbon oxygen scavenger which is incorporated into a film layer and used for making packaging for oxygen sensitive products. The oxygen scavenger is catalyzed by a transition metal catalyst and a chloride, acetate, stearate, palmitate, 2-ethylhexanoate, neodecanoate or naphthenate counterion. Preferred metal salts are selected from cobalt (II) 2-ethylhexanoate and cobalt (II) neodecanoate. Because water deactivates the oxygen scavenger composition, the composition can only be used for packaging for dry materials.
There remains a need for the selection of a substrate which can provide oxygen scavenging in order to reduce the oxidation of the constituents contained therein. Accordingly, it is an object of the invention to provide an improved oxygen scavenging blend for use in coating substrates for food packaging applications.
The present invention provides a single polyamide layer which is an effective oxygen barrier as well as a multiple layered structure formed from the polyamide layer to provide even more effective oxygen barrier properties. These high oxygen barrier polyamide compositions exhibit unusually high oxygen scavenging capability suitable for extended shelf-life, packaging applications. The oxygen scavenging polyamide compositions may be prepared by a reactive extrusion process of compounding polyamides with a small amount of a low molecular weight, oxidizable polydiene or polyether polymer. The polyamide products are particularly suited to making barrier packaging articles which are useful in a variety of oxygen-sensitive applications.
SUMMARY OF THE INVENTION
The invention provides a polyamide composition which comprises a polyamide homopolymer, copolymer, or blends thereof, and at least one polyamide reactive, oxidizable polydiene or oxidizable polyether.
The invention also provides a polyamide composition which comprises a blend of a polyamide homopolymer, copolymer, or blends thereof, and at least one polyamide reactive, oxidizable polydiene or oxidizable polyether.
The invention further provides a polyamide composition which comprises the reaction product of a polyamide homopolymer, copolymer, or blends thereof, and at least one polyamide reactive, oxidizable polydiene or oxidizable polyether.
At The invention still further provides a oxygen barrier film comprising a layer of a polyamide composition which comprises a polyamide homopolymer, copolymer, or blends thereof, and at least one polyamide reactive, oxidizable polydiene or oxidizable polyether.
The invention yet further provides a multilayer article which comprises an oxygen barrier polyamide composition layer comprising a polyamide homopolymer, copolymer, or blends thereof, and at least one polyamide reactive, oxidizable polydiene or oxidizable polyether, and a thermoplastic polymer layer on one or both sides of the polyamide composition layer.
The invention also provides a shaped article which comprises a polyamide composition which comprises a polyamide homopolymer, copolymer, or blends thereof, and at least one polyamide reactive, oxidizable polydiene or oxidizable polyether.
The invention further provides a process for producing a polyamide composition which comprises melting a polyamide homopolymer, copolymer, or blends thereof, and blending the molten polyamide homopolymer, copolymer, or blend thereof with at least one polyamide reactive, oxidizable polydiene or oxidizable polyether to form a mixture, and then cooling the mixture.
The invention also provides a process for producing an oxygen barrier polyamide film which comprises melting a polyamide homopolymer, copolymer, or blends thereof, and-blending the molten polyamide homopolymer, copolymer, or blend thereof with at least one polyamide reactive, oxidizable polydiene or oxidizable polyether to form a mixture, and then extruding, casting or blowing the mixture into a film with subsequent cooling.
The invention also provides a process for producing an oxygen barrier polyamide film which comprises melting a composition comprising a polyamide homopolymer, copolymer, or blends thereof, and at least one polyamide reactive, oxidizable polydiene or oxidizable polyether, and then extruding, casting or blowing the composition into a film with subsequent
The invention also provides a process for producing a multilayer article which comprises melting a polyamide homopolymer, copolymer, or blends thereof, and blending the molten polyamide homopolymer, copolymer, or blend thereof at least one polyamide reactive, oxidizable polydiene or oxidizable polyether to form a mixture; separately melting a thermoplastic polymer composition; and then coextruding, casting, blowing, thermoforming, blow molding or coinjecting the mixture and thermoplastic polymer composition into a multilayer article, with subsequent cooling.
The invention also provides a process for producing a multilayer article which comprises melting a composition comprising a polyamide homopolymer, copolymer, or blends thereof, and at least one polyamide reactive, oxidizable polydiene or oxidizable polyether; separately melting a thermoplastic polymer composition; and then coextruding, casting, blowing, thermoforming, blow molding or coinjecting the mixture and thermoplastic polymer composition into a multilayer article, with subsequent cooling.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a graph of the oxygen transmission data for Examples 6 and 9 and Comparative Example 1.
FIG. 2 shows a graph of the oxygen transmission data for Examples 11 and 13 and Comparative Examples 1, 4 and 5.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In the present invention, an improved polyamide composition is prepared by combining a polyamide homopolymer, copolymer, or blends thereof and an oxidizable polydiene or polyether. Preferably the composition also comprises a metal carboxylate salt catalyst and a nanoscale clay.
The preferred polyamide homopolymer or copolymer is selected from aliphatic polyamides and aliphatic/aromatic polyamides having a molecular weight of from about 10,000 to about 100,000. General procedures useful for the preparation of polyamides are well known to the art Useful diacids for making polyamides include dicarboxylic acids which are represented by the general formula
HOOC—Z—COOH
wherein Z is representative of a divalent aliphatic radical containing at least 2 carbon atoms, such as adipic acid, sebacic acid, octadecanedioic acid, pimelic acid, suberic acid, azelaic acid, dodecanedioic acid, and glutaric acid. The dicarboxylic acids may be aliphatic acids, or aromatic acids such as isophthalic acid and terephthalic acid. Suitable diamines for making polyamides include those having the formula
H 2 N(CH 2 ) n NH 2
wherein n has an integer value of 1-16, and includes such compounds as trimethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, octamethylenediamine, decamnthylenediarmine, dodecamethylenediamine, hexadecamethylenediamine, aromatic diamines such as p-phenylenediamine, 4,4′-diaminodiphenyl ether, 4,4′-diaminodiphenyl sulphone, 4,4′-diaminodiphenylmethane, alkylated diamines such as 2,2-dimethylpentamethylenediamine, 2,2,4-trimethylhexamethylenediamine, and 2,4,4 trimethylpentamethylenediamine, as well as cycloaliphatic diamines, such as diaminodicyclohexylmethane, and other compounds. Other useful diamines include heptamethylenediamine, nonamethylenediamine, and the like.
Useful aliphatic polyamide homopolymers include poly(4-aminobutyric acid) (nylon 4), poly(6-aminohexanoic acid) (nylon 6, also known as poly(caprolactam)), poly(7-aminoheptanoic acid) (nylon 7), poly(8-aminooctanoic acid) (nylon 8), poly(9-aminononanoic acid) (nylon 9), poly(10-aminodecanoic acid) (nylon 10), poly(11-amioundecanoic acid) (nylon 11), poly(12-aminododecanoic acid) (nylon 12), poly(hexamethylene adipamide) (nylon 6,6), poly(hexamethylene sebacamide) (nylon 6,10), poly(heptamethylene pimelamide) (nylon 7,7), poly(octamethylene suberamide) (nylon 8,8), poly(hexamethylene azelamide) (nylon 6,9), poly(nonamethylene azelamide) (nylon 9,9), poly(decamethylene azelamide) (nylon 10,9), poly(tetramethylene adipamide (nylon 4,6), caprolactam/hexamethylene adipamide copolymer (nylon 6,6/6), hexamethylene adipamide/caprolactam copolymer (nylon 6/6,6), trimethylene adipamide/hexamethylene azelaiamide copolymer (nylon trimethyl 6,2/6,2), hexamethylene adipamide-hexamethylene-azelaiamide caprolactam copolymer, (nylon 6,6/6,9/6), poly(tetramethylenediamine-co-oxalic acid) (nylon 4,2), the polyamide of n-dodecanedioic acid and hexamethylenediamine (nylon 6,12), the polyamide of dodecamethylenediamine and n-dodecanedioic acid (nylon 12,12), as well as blends and copolymers thereof and other polyamides which are not particularly delineated here.
Of these polyamides, preferred polyamides include polycaprolactam, which is also commonly referred to as nylon 6, and polyhexamethylene adipamide, which is also commonly referred to as nylon 6,6, as well as mixtures of the same. Of these, polycaprolactam is most preferred.
Polyamides used in the practice of this invention may be obtained from commercial sources or prepared in accordance with known preparatory techniques. For example, poly(caprolactam) can be obtained from Honeywell International Inc., Morristown, N.J. under the trademark CAPRON®. Suitable variants of CAPRON® for use as a first polyamide in the present invention include CAPRON® 8200 nylon, a balanced nylon 6 having a formic acid viscosity (FAV) of 75, CAPRON® 1767 nylon, a balanced nylon 6 having an FAV of 35, and CAPRON® 8224HSL nylon, a heat stabilized, lubricated nylon 6 having an FAV of 60. A suitable variant of CAPRON® nylon for use as a second polyamide includes CAPRON® 1250 nylon, an amine-terminated nylon 6 with a FAV of 60 and having terminal amino groups of 70 to 78 milliequivalents per gram.
Exemplary of aliphatic/aromatic polyamides include poly (2,2,2-trimethyl hexamethylene terephthalamide), poly(m-xylylene adipamide) (MXD6), poly(p-xylylene adipamide), poly(hexamethylene terephthalamide) (nylon 6,T), poly(hexamethylene isophthalamide) (nylon 6,I), poly(dodecamethylene terephthalamide), polyamide 6T/6I, poly(tetramethylenediamine-co-isophthalic acid) (nylon 4,I), polyamide 6/MXT/I, polyamide MXDI, hexamethylene adipamide/hexamethylene-isophthalamide (nylon 6,6/6I), hexamethylene adipamide/hexamethyleneterephthalamide (nylon 6,6/6T) and as well as others which are not particularly delineated here. Blends of two or more aliphatic/aromatic polyamides and/or aliphatic polyamides can also be used. Aliphatic/aromatic polyamides can be prepared by known preparative techniques or can be obtained from commercial sources. Other suitable polyamides are described in U.S. Pat. Nos. 4,826,955 and 5,541,267, which are incorporated herein by reference.
The polyamide component is present in the overall composition in an amount of from about 80% to about 99.9% by weight, preferably from about 90% to about 99%o and more preferably from about 95% to about 98%.
The composition of the current invention also contains a functional, nylon reactive, oxidizable polydiene or polyether as an oxygen scavenger. Such are low molecular weight, small particles which are compatible and uniformly dispersible in the polyamide. Preferably the nylon reactive, oxidizable polydiene or polyether comprises an epoxy or anhydride functionality such that it reacts with the carboxyl or amino end groups of the polyamide. The functionality in the polydiene or polyether may also react with amide group in the polyamide backbone. The functionality can be pendant to the backbone or at the chain ends of the polydiene or polyether. The preferred functional polydienes are functional polyalkadiene oligomers which can have the following general backbone structure.
where R 1 , R 2 , R 3 and R 4 can be the same or different and can be selected from hydrogen (—H) or any of the lower alkyl groups (methyl, ethyl, propyl, butyl etc.). R 2 & R3 may also be a chloro (—Cl) group. Illustrative of the backbone structure are polybutadiene (1,4 or 1,2 or mixtures of both), polyisoprene (1,4 or 3,4), poly 2,3-dimethyl butadiene, polychloroprene, poly 2,3-dichlorobutadiene, polyallene, poly 1,6-hexatriene, etc.
Specific non-limiting examples of functional, oxidizable polydienes as suitable oxygen scavengers include epoxy functionalized polybutadiene (1,4 and/or 1,2), maleic anhydride grafted or copolymerized polybutadiene (1,4 and/or 1,2), epoxy functionalized polyisoprene, and maleic anhydride grafted or copolymerized polyisoprene.
Specific non-limiting examples of functional oxidizable polyethers as oxygen scavengers include amine, epoxy or anhydride functionalized polypropylene oxide, polybutylene oxide (2,3 or 1,2) and polystyrene oxide. The preferred oxygen scavenger is an epoxy functional polybutadiene oligomer. The oxygen scavenger is present in the polyamide composition as a large number of small particles. The molecular weight of the functional polydiene or polyether oligomer may range from about 500 about to 5,000, preferably from about 750 to about 3000 and most preferably from about 1000 to about 2000. It is present in the overall composition in an amount of from about 0.1% to about 10% by weight, preferably from about 1% to about 10% and more preferably from about 2% to about 5%. The functional, oxidizable polydiene or polyether is in the form of particles whose average particle size is in the range of from about 10 nm to about 1000 nm, wherein the particles are substantially uniformly distributed in the polyamide. The polyamide composition may comprise either a blend of the polyamide and the polydiene or polyether, or a reaction product of the polyamide with the oxidizable polydiene or polyether.
Preferably the composition further comprises a metal fatty acid salt catalyst such as a low molecular weight metal carboxylate salt catalyst. Suitable metal fatty acid salt catalysts have a counterion which is an acetate, stearate, propionate, hexanoate, octanoate, benzoate, salicylate, and cinnamate or combination thereof. Preferably the metal fatty acid salt catalyst is a cobalt, copper or ruthenium, acetate, stearate, propionate, hexanoate, octanoate, benzoate, salicylate or cinnamate, or combinations thereof The preferred metal carboxylate is cobalt, ruthenium or copper carboxylate. Of these the more preferred is cobalt or copper carboxylate and the most preferred is cobalt carboxylate. It is present in the overall composition in an amount of from about 0% to about 1% by weight, preferably from about 0.001% to about 0.5% and more preferably from about 0.005% to about 0.1%. The most preferred range is from about 0.01% to about 0.05%.
Preferably the composition further comprises a nanometer scale dispersed clay. Suitable clays are described in U.S. Pat. No. 5,747,560, which is incorporated herein by reference. Preferred clays non-exclusively include a natural or synthetic phyllosilicate such as montmorillonite, hectorite, vermiculite, beidilite, saponite, nontronite or synthetic flouromica, which has been cation exchanged with a suitable organoammonium salt. The preferred clay is montmorillonite, bectorite or synthetic flouromica. The more preferred clay is the montmorillonite or hectorite. The most preferred clay is montmorillonite. The preferred organoammonium cation for treating the clay is N,N′,N″,N′″Bis(hydroxyethyl), methyl, octadecyl ammonium cation or ω-carboxy alkylammonium cation, i.e., the ammonium cation derived such ω-aminoalkanoic acids as 6-amionocaproic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid. The preferred fine dispersions of nanometer scale silicate platelets are obtained either via an in-situ polymerization of polyamide forming monomer(s) or via melt compounding of polyamide in the presence of the organoammonium salt treated clay. The clay has an average platelet thickness in the range of from about 1 nm to about 100 nm and an average length and average width each in the range of from about 50 nm to about 500 nm. It is present in the overall composition in an amount of from about 0% to about 10% by weight, preferably from about 2% to about 8% and more preferably from about 3% to about 6%.
The composition of the invention may optionally also include one or more conventional additives whose uses are well known to those skilled in the art The use of such additives may be desirable in enhancing the processing of the compositions as well as improving the products or articles formed therefrom. Examples of such include: oxidative and thermal stabilizers, lubricants, mold release agents, flame-retarding agents, oxidation inhibitors, dyes, pigments and other coloring agents, ultraviolet light stabilizers, organic or inorganic fillers including particulate and fibrous fillers, reinforcing agents, nucleators, plasticizers, as well as other conventional additives known to the art Such may be used in amounts of up to about 10% by weight of the overall composition.
Representative ultraviolet light stabilizers include various substituted resorcinols, salicylates, benzotriazole, benzophenones, and the like. Suitable lubricants and mold release agents include stearic acid, stearyl alcohol, and stearamides. Exemplary flame-retardants include organic halogenated compounds, including decabromodiphenyl ether and the like as well as inorganic compounds. Suitable coloring agents including dyes and pigments include cadmium sulfide, cadmium selenide, titanium dioxide, phthalocyanines, ultramarine blue, nigrosine, carbon black and the like. Representative oxidative and thermal stabilizers include the Period Table of Element's Group I metal halides, such as sodium halides, potassium halides, lithium halides; as well as cuprous halides; and further, chlorides, bromides, iodides. Also, hindered phenols, hydroquinones, aromatic amines as well as substituted members of those above mentioned groups and combinations thereof Exemplary plasticizers include lactams such as caprolactam and lauryl lactam, sulfonamides such as o,p-toluenesulfonamide and N-ethyl, N-butyl benylnesulfonamide, and combinations of any of the above, as well as other plasticizers known to the art.
Suitable fillers include inorganic fillers, including those of fibrous and granular nature, as wells as mixtures thereof The fibrous fillers include glass, silica glass, ceramic, asbestos, alumina, silicon carbide, gypsum, metal (including stainless steel) as well as other inorganic and carbon fibers. The granular fillers include wollastonite, sericite, asbestos, talc, mica, clay, kaolin, bentonite, and silicates, including alumina silicate. Other granular fillers include metal oxides, such as alumina, silica, magnesium oxide, zirconium oxide, titanium oxide. Further granular fillers include carbonates such as calcium carbonate, magnesium carbonate, and dolomite, sulfates including calcium sulfate and barium sulfate, boron nitride, glass beads, silicon carbide, as well as other materials not specifically denoted here. These fillers may be hollow, for example glass microspheres, silane balloon, carbon balloon, and hollow glass fiber. Preferred inorganic fillers include glass fibers, carbon fibers, metal fibers, potassium titanate whisker, glass beads, glass flakes, wollastonite, mica, talc, clay, titanium oxide, aluminum oxide, calcium carbonate and barium sulfate. Particularly, glass fiber is most preferred. The inorganic fillers should preferably be treated with silane, titanate, or another conventional coupling agent, and glass fibers should preferably be treated with an epoxy resin, vinyl acetate resin or other conventional converging agent.
Preferably the polyamide compositions are produced via a melt extrusion compounding of the polyamide with the other composition components. The composition may be formed by dry blending solid particles or pellets of each of the polyamide components and then melt blending the mixture in a suitable mixing means such as an extruder, a roll mixer or the like. Typical melting temperatures range from about 230° C. to about 300° C., preferably from about 235° C. to about 280° C. and more preferably from about 240° C. to about 260° C. for nylon 6 and its copolymers. Blending is conducted for a period of time required to attain a substantially uniform blend Such may easily be determined by those skilled in the art. If desired, the composition may be cooled and cut into pellets for further processing, it may be extruded into a fiber, a filament, or a shaped element or it may be formed into films and optionally uniaxially or biaxially stretched by means well known in the art.
The barrier polyamide films and articles of this invention may be produced by any of the conventional methods of producing films and articles, including extrusion and blown film techniques, bottles via extrusion or injection stretch blow molding and containers via thermoforming techniques. Processing techniques for making films, sheets, containers and bottles are well known in the art. For example, the polyamides may be preblended and then the blend fed into an infeed hopper of an extruder, or each polyamide may be fed into infeed hoppers of an extruder and then blended in the extruder. The melted and plasticated stream from the extruder is fed into a single manifold die and extruded into a layer. It then emerges from the die as a single layer film of nylon material. After exiting the die, the film is cast onto a first controlled temperature casting roll, passes around the first roll, and then onto a second controlled temperature roll, which is normally cooler than the first roll. The controlled temperature rolls largely control the rate of cooling of the film after it exits the die. Once cooled and hardened, the result film is preferably substantially transparent.
Alternatively the composition may be formed into a film using a conventional blown film apparatus. The film forming apparatus may be one which is referred to in the art as a “blown film” apparatus and includes a circular die head for bubble blown film through which the plasticized film composition is forced and formed into a film “bubble”. The “bubble” is ultimately collapsed and formed into a film.
The composition may also be used to form shaped article through any well known process, including extrusion blow molding and injection stretch-blow molding. An injection molding process softens the thermoplastic nylon blend in a heated cylinder, injecting it while molten under high pressure into a closed mold, cooling the mold to induce solidification, and ejecting the molded preform from the mold. Molding compositions are well suited for the production of preforms and subsequent reheat stretch-blow molding of these preforms into the final bottle shapes having the desired properties. The injection molded preform is heated to suitable orientation temperature in the 100° C.-150° C. range and then stretch-blow molded. The latter process consists of first stretching the hot preform in the axial direction by mechanical means such as by pushing with a core rod insert followed by blowing high pressure air (up to 500 psi) to stretch in the hoop direction. In this manner, a biaxially oriented blown bottle is made. Typical blow-up ratios range from 5/1 to 15/1.
The barrier polyamide composition of this invention may be formed as an integral layer in a multilayered film, bottle or container which include one or more layers of another thermoplastic polymer such as polyesters—particularly polyethylene terephthalate (PET) and PET copolymers, polyolefins, ethylene vinyl alcohol copolymers, acrylonitrilecopolymers, acrylic polymers, vinyl polymers, polycarbonate, polystyrene, etc. The polyamide composition of this invention is particularly suitable as a barrier layer in the construction and fabrication of multilayer bottles and thermoformed containers in which PET or polyolefin function as structural layers. Such PET/polyamide multilayer bottles can be made by coinjection stretch-blowmolding process similar to the injection-stretch blowmolding process describe before. Similarly, polyamide/polyolefin multilayer bottles can be made by coextrusion blowmolding. The latter process usually employs suitable tie layers for adhesion.
Useful polyesters for coinjection stretch blowmolding process include polyethylene terephthalate (PET) and its copolymer in the intrinsic viscosity (I.V.) range of 0.5-1.2 d1g range, more preferably in the I.V. range of 0.6 to 1.0 and most preferably in the I.V. range of 0.7-0.9. The polyolefins used in the coextrusion blowmolding include polymers of alpha-olefin monomers having from about 2 to about 6 carbon atoms and includes homopolymers, copolymers (including graft copolymers), and terpolymers of alpha-olefins. Illustrative homopolymer examples include ultra low density (ULDPE), low density (LDPE), linear low density (LLDPE), medium density (MDPE), or high density polyethylene (HDPE); polypropylene; polybutylene; polybutene-1; poly-3-methylbutene-1; poly-pentene-1; poly-4-methylpentene-1; polyisobutylene; and polyhexene. The polyolefin may have a weight average molecular weight of about 1,000 to about 1,000,000, and preferably about 10,000 to about 500,000. Preferred polyolefins are polyethylene, polypropylene, polybutylene and copolymers, and blends thereof. The most preferred polyolefins are polyethylene and polypropylene.
Copolymers of ethylene and vinyl alcohol suitable for use in the present invention can be prepared by the methods disclosed in U.S. Pat. Nos. 3,510,464; 3,560,461; 3,847,845; and 3,585,177. Additional layers may also include adhesive tie layers to tie various layers together. Non-limiting examples of other optional polymeric layers and adhesive or tie layers which can be used in the film laminate of the present invention are disclosed in U.S. Pat. Nos. 5,055,355; 3,510,464; 3,560,461; 3,847,845; 5,032,656; 3,585,177; 3,595,740; 4,284,674; 4,058,647; and 4,254,169.
The multilayered barrier articles of this invention can be formed by any conventional technique for forming films, including lamination, extrusion lamination, coinjection, stretch-blow molding and coextrusion blowmolding. The preferred method for making multilayer film is by coextrusion. For example, the material for the individual layers, as well as any optional layers, are fed into infeed hoppers of the extruders of like number, each extruder handling the material for one or more of the layers. The melted and plasticated streams from the individual extruders are fed into a single manifold co-extrusion die. While in the die, the layers are juxtaposed and combined, then emerge from the die as a single multiple layer film of polymeric material. After exiting the die, the film is cast onto a first controlled temperature casting roll, passes around the first roll, and then onto a second controlled temperature roll, which is normally cooler than the first roll. The controlled temperature rolls largely control the rate of cooling of the film after it exits the die. In another method, the film forming apparatus may be one which is referred to in the art as a blown film apparatus and includes a multi-manifold circular die head for bubble blown film through which the plasticized film composition is forced and formed into a film bubble which may ultimately be collapsed and formed into a film. Processes of coextrusion to form film and sheet laminates are generally known. See for example in “Modern Plastics Encyclopedia”, Vol. 56, No. 10A, pp. 131-132, McGraw Hill, October 1979. Alternatively the individual layers may first be formed into sheets and then laminated together under heat and pressure with or without intermediate adhesive layers.
Adjacent to the fluoropolymer layer is an adhesive layer, also referred to in the art as a “tie” layer, between each film layer. In accordance with the present invention, suitable adhesive polymers include modified polyolefin compositions having at least one functional moiety selected from the group consisting of unsaturated polycarboxylic acids and anhydrides thereof. Such unsaturated carboxylic acid and anhydrides include maleic acid and anhydride, fumaric acid and anhydride, crotonic acid and anhydride, citraconic acid and anhydride, itaconic acid an anhydride and the like. Of these, the most preferred is maleic anhydride. The modified polyolefins suitable for use in this invention include compositions described in U.S. Pat. Nos. 3,481,910; 3,480,580; 4,612,155 and 4,751,270 which are incorporated herein by reference. Other adhesive layers non-exclusively include alkyl ester copolymers of olefins and alkyl esters of α,β-ethylenically unsaturated carboxylic acids such as those described in U.S. Pat. No. 5,139,878. The preferred modified polyolefin composition comprises from about 0.001 and about 10 weight percent of the functional moiety, based on the total weight of the modified polyolefin. More preferably the functional moiety comprises from about 0.005 and about 5 weight percent, and most preferably from about 0.01 and about 2 weight percent. The modified-polyolefin composition may also contain up to about 40 weight percent of thermoplastic elastomers and alkyl esters as described in U.S. Pat. No. 5,139,878.
Nylon films produced according to the present invention may be oriented by stretching or drawing the films at draw ratios of from about 1.1:1 to about 10:1, and preferably at a draw ratio of from about 2:1 to about 5:1. The term “draw ratio” as used herein indicates the increase of dimension in the direction of the draw. Therefore, a film having a draw ratio of 2:1 has its length doubled during the drawing process. Generally, the film is drawn by passing it over a series of preheating and heating rolls. The heated film moves through a set of nip rolls downstream at a faster rate tan the film entering the nip rolls at an upstream location The change of rate is compensated for by stretching in the film.
The film may be stretched or oriented in any desired direction using methods well known to those skilled in the art. The film may be stretched uniaxially in either the longitudinal direction coincident with the direction of movement of the film being withdrawn from the film forming apparatus, also referred to in the art as the “machine direction”, or in as direction which is perpendicular to the machine direction, and referred to in the art as the “transverse direction”, or biaxially in both the longitudinal direction and the transverse direction.
The thickness of the polyamide film is preferably from about 0.05 mils (1.3 μm) to about100 mils (2540 μm), and more preferably from about 0.05 mils (1.3 μm) to about 50 mils (1270 μm). While such thicknesses are preferred as providing a readily flexible film, it is to be understood that other film thicknesses may be produced to satisfy a particular need and yet fall within the scope of the present invention; such thicknesses which are contemplated include plates, thick films, and sheets which are not readily flexible at room temperature (approx. 20° C.).
One noteworthy characteristic of the articles made from the compositions of this invention is that they exhibit excellent gas barrier properties, particularly oxygen barrier properties. Oxygen permeation resistance or barrier may be measured using the procedure of ASTM D-3985. In general, the films of this invention have an oxygen transmission rate (O 2 TR) at 90% relative humidity less than about 1.0 cm 3 /100 in 2 (645 cm 2 )/24 hrs/Atm at 23° C. and usually less than about 0.5 cm 3 /100 in 2 (645 cm 2 )/24 hrs/Atm at 23° C.
The following non-limiting examples serve to illustrate the invention.
PROCESSING DETAILS
Reactive Extrusion
Process 1: A Leistritz 18-mm co-rotating twin screw extruder equipped with a K-Tron volumetric feeder was employed. The polybutadiene (either carboxy terminated polybutadiene—Hycar, or epoxy functionalized polybutadiene—Elf-Atochem Poly BD 600/Poly BD605E) was stored in a sealed drum and metered with a Nichols-Zenith pump directly into a sealed extruder barrel directly following the feed barrel. The polybutadiene was injected prior to the first (of two) mixing zones via a Leistritz direct liquid injection nozzle. Nylon 6 pellets, or blends of nylon 6/amorphous nylon, nylon 6/EVOH, or other materials, were fed into the nitrogen-blanketed throat of the extruder at a rate of 10 pounds (22 kg) per hour. The polybutadiene was pumped at a rate such that weight percentages of 1% to 5% polybutadiene were added. The extruder was equipped-with two mixing zones consisting primarily of kneading elements. The extruder was equipped with a vacuum zone subsequent to the second mixing zone and prior to the die plate. The extrudate was quenched in a water bath and then pelletized.
Process 2: A Leistritz 18-mm co-rotating twin screw extruder equipped with a K-Tron volumetric feeder was employed. The polybutadiene (either carboxy terminated polybutadiene—Hycar, or epoxy functionalized polybutadiene—Elf-Atochem Poly BD 600/Poly BD 605E) was stored in a sealed drum and metered with a Nichols-Zenith into the extruder throat. Nylon 6 pellets or other materials were fed into the nitrogen-blanketed throat of the extruder at a rate of 5 pounds (11 kg) per hour. The polybutadiene was pumped at a rate such that weight percentages of 1% to 5% polybutadiene were added. The extruder was equipped with two mixing zones consisting primarily of kneading elements. The extrudate was quenched in a water bath and then pelletized.
Process 3: A Leistritz 18-mm co-rotating twin screw extruder equipped with a K-Tron volumetric feeder was employed. A blend of nylon 6 pellets and cobalt stearate pastilles were fed into the nitrogen-blanketed throat of the extruder at a rate of 10 pounds (22 kg) per hour. The blend consisted of 95% nylon 6 and 5% cobalt stearate. The extruder was equipped with two mixing zones consisting primarily of kneading elements. The extrudate was quenched in a water bath and then pelletized. The resulting pellet was used as a masterbatch additive in some of the processes listed below.
Process 4: A:Leistritz 18-mm co-rotating twin screw extruder equipped with a K-Tron volumetric feeder was employed. The polybutadiene (either carboxy terminated polybutadiene—Hycar, or epoxy functionalized polybutadiene—Elf-Atochem Poly BD 600/Poly BD 605E) was stored in a sealed drum vessel and metered with a Nichols-Zenith pump directly in the extruder barrel following the feed throat. The polybutadiene was injected directly into the extruder prior to the first (of two) mixing zones via a Leistritz direct liquid injection nozzle. A blend of nylon 6 and cobalt stearate masterbatch was fed into the nitrogen-blanketed throat of the extruder at a rate of 10 pounds per hour. The blend consisted of approximately 98 weight percent nylon 6 and 2 weight percent cobalt masterbatch. The polybutadiene was pumped at a rate such that weight percentages of 1% to 5% polybutadiene were added. The extruder was equipped with two mixing zones consisting primarily of kneading elements. The extruder was equipped with a vacuum zone subsequent to the second mixing zone and prior to the die plate. The extrudate was quenched in a water bath and then pelletized.
Pellet Blending
Process 5: Blending of 98 weight percent material prepared in process 1 or 2 (or other material) and 2 weight percent material prepared in process 3. Blending was accomplished by weighing out required amount of each material into a large container. The container was tumbled for approximately 5 minutes to ensure thorough mixing of the two components. These blends were used subsequently as feedstock for cast film processing.
Cast Film
Process 6: A Haake single screw extruder equipped with a six-inch (152.4 mm) wide film die was flood fed with pellets from process 3, 5 or 6. Extruder temperature was set at approximately 260° C. Extrudate passed through the slit die onto a heated Killion cast roll. Film thickness was adjusted via cast roll speed and/or screw RPM to prepare a film with typical thickness of 0.001 inch to 0.003 inch (0.0254 to 0.0762 mm).
Process 7: A Killion 1.5 inch (38.1 mm) single screw extruder equipped with a twelve-inch wide film die was flood fed with pellets from process 3, 5 or 6. Extruder temperature was set at approximately 260° C. Extrudate passed through the slit die onto a heated Killion cast roll. Film thickness was adjusted via cast roll speed and/or screw RPM to prepare a film with typical thickness of 0.001 inch to 0.003 inch (0.0254 to 0.0762 mm).
Process 8: Three Killion single screw extruders equipped with a twelve-inch wide film coextrusion die were utilized to prepare a three-layer film. One extruder was flood fed with pellets from process 5. Two extruders were flood fed with approximately 1.0 IV PET. Extruder temperatures were approximately 260° C. for pellets from process 5 and 280° C. for PET pellets. Extrudate passed through the slit die onto a heated cast roll. Film thickness was adjusted via cast roll speed and/or screw RPM to prepare a film of the following thickness: 0.004 inch (0.1016 mm) PET outer layers and 0.002 inch (0.0508 mm) active barrier nylon inner layer.
Oxygen Transmission Measurements
Oxygen transmission measurements were conducted on film samples on a Mocon Oxtran 2/20 apparatus equipped with SL sensors. Tests were conducted at 80% to 90% relative humidity in air (21% oxygen). Data were collected as a function of time and recorded in units of: cc-mil/100 in 2 /atm day. Tests were conducted for up to 28 days.
Description of Examples
Listed in the Table are the summarized results obtained from the following examples which illustrate the effect on oxygen transmission rate of the oxygen binding system described herein.
COMPARATIVE EXAMPLES 1-8
Comparative examples 1-8 are useful as reference points or “baselines” for the examples which will be described later. Comparative example 1 is a commercial grade nylon 6 homopolymer available from Honeywell. Comparative example 2 is a nylon 6 homopolymer containing 100 ppm cobalt. Comparative example 2 illustrates that a 100 ppm addition of cobalt to nylon 6 has no affect on the oxygen transmission rate of nylon 6. Comparative example 3 is a nylon 6 homopolymer containing 3 weight percent Poly BD 600. This example illustrates that the addition of 3 weight percent Poly BD 600 (epoxy functionalized 1,3 polybutadiene) to nylon 6 worsens the oxygen transmission rate. Comparative example 4 is an experimental grade nylon 6/nanoclay blend (Nanomer I24TL organoclay polymerized in situ with nylon 6). Comparative example 5 is a commercially available nylon 6/nanocomposite from Unitika. Comparative example 6 is a commercially available semi-aromatic nylon 6 from Mitsubishi (MXD6). Comparative example 7 is MEXD6 containing 100 ppm cobalt. Comparative example 8 is a commercially available amorphous nylon (Grivory) available from EMS.
EXAMPLES 1-9
Examples 1-9 illustrate the effect of the oxygen binding system on the oxygen transmission rate of nylon 6. The examples illustrate the dramatic improvement in oxygen binding ability of the copolymers of this invention. In general for all examples the oxygen binding epoxy functionalized polybutadiene is nano/micro-phase separated from the nylon matrix with polybutadiene particle size on the order of 10-1000 nm. Example 1 is a copolymer of this invention containing 1 weight percent Poly BD-600 and 100 ppm by weight of cobalt. Samples of this example were prepared by methods 1,3,5 and 6 (described above). Example 2 is the same as example 1 except it contains 2 weight percent Poly BD 600. Example 3 is the same as example 1 except it contains 3 weight percent Poly BD 600. The oxygen transmission rate of example 3 decreases rapidly to near zero (3.4 E-3 cc mil/100 in 2 /atm day after 2 days) and remains low (less than 0.1 cc mil/100 in 2 /atm day) for five days. Example 4 is similar to example one except that compounding method 2 was used rather than compounding method 1 (each described above). Compounding method 1 is preferable because whiter pellets are obtained. Whiter pellets are the result of direct liquid injection of Poly BD 600/605E into the extruder in the absence of air which prevents oxidation of the polybutadiene). The oxygen transmission rate of example 4 results in very low oxygen transmission rate for 5 days. Examples 3 and 4 have an average 65 times lower oxygen transmission rate of over a 5 day period relative to comparative examples 1, 2 and 3. Example 5 is a copolymer of this invention containing three weight percent Poly BD 600 and 100 ppm by weight cobalt. This example, in which the cobalt and Poly BD 600 were added simultaneously to the same extruder (methods 4 and 7 described above), exhibited a low oxygen transmission rate for 3 days. Examples 3 and 5 were comparable in their oxygen scavenging behavior and were an average 25 times lower in oxygen transmission rate over a 5 day period relative to comparative examples 1, 2 and 3. This illustrates that the oxygen binding effect is observed in films prepared from two differently prepared starting materials, i.e. (1) a pellet blend approach (methods 1, 2 and 3) or (2) a fully compounded approach (method 4). Example 6 is the same as Example 3 except that Poly BD 605E (higher epoxy functionality relative to Poly BD 600) was used. Example 7 is similar to example eight except it contains 4 weight percent Poly BD 600. Example 8 is a copolymer of this invention containing 5 weight percent Hycar carboxy terminated polybutadiene (Hycar CTB). Samples were prepared by methods 2, 3, 5 and 7. The oxygen transmission rates measured on this example illustrate that Hycar CTB is a less effective oxygen binding polybutadiene. However, this example did exhibit lower oxygen transmission rates than comparative examples 1, 2 and 3. Example 9 is a co-extruded cast film example comprised of example three as a barrier layer between two PET outer layers. The sample was made with process steps 1, 3, 5 and 8. The outer layers of PET result in a film with a longer near zero oxygen transmission rate as compared with a neat film of the barrier layer (example 3). The oxygen transmission data for comparative example 1 and examples 6 and 9 are given in FIG. 1 .
EXAMPLES 10-13
Examples 10-13 illustrate the effect of the oxygen binding system on the oxygen transmission rate of a nylon 6/organo-clay blend of this invention and a commercially available grade of nylon 6/organo-clay blend. The oxygen transmission data for examples 11 and 13 and comparative examples 1, 4 and 5 are given in FIG. 2 . These examples illustrate the dramatic improvement in oxygen binding ability of the copolymers of this invention. Further, these examples demonstrate the synergistic effect of combining the oxygen binding system of this invention with a nylon 6 with organo-clay). The passive barrier afforded by the organo-clay combined with the active barrier of the oxygen binding copolymers result in a nylon 6 material with dramatically improved oxygen transmission properties. Example 10 is a copolymer of this invention containing 98 weight percent nylon 6/nanocomposite (containing 6 weight percent Nanocor Nanomer I24T), 2 weight percent Poly BD 600 and 100 ppm by weight cobalt and was prepared by methods 1, 3, 5 and 6. The oxygen transmission rate of example 10 is near zero for 10 days (test duration) and is 225 times less than comparative examples 1, 2 and 3. Example 11 is the same as example 10 except it contains 3 weight percent Poly BD 600. This example has a near zero oxygen transmission rate for 10 days (test duration) and is more than 900 times lower in oxygen transmission rate relative to comparative examples 1, 2 and 3. Example 12 was prepared as a blend of 77 weight percent nylon 6/organo-clay blend (containing 6 weight percent Nanocor Nanomer I24T), 20 weight percent amorphous nylon (EMS Grivory G21), 3 weight percent Poly BD 600 and 100 ppm cobalt This example exhibited a very low oxygen transmission rate for 16 days (test duration) and is at least 105 times lower in oxygen transmission rate relative to comparative examples 1, 2 and 3. Example 13 is a copolymer of this invention containing 95% nylon 6/organo-clay blend (commercially available from Unitika), 5 weight percent Poly BD 600 and 100 ppm cobalt. This example exhibited a very low oxygen transmission rate for 26 days (test duration) and is 300 times lower in oxygen transmission rate relative to comparative examples 1, 2 and 3. There exists a strong synergy when a passive barrier (organo-clay) is combined with an active barrier system (epoxy functionalized polybutadiene/cobalt). This may be the result of increased “tortuosity” for oxygen diffusing through the barrier material due to the elongated (high aspect ratio) clay particles and the presence of the highly dispersed and finely sized polybutadiene phase. Oxygen molecules are blocked by the clay particles and then forced to the epoxy functionalized polybutadiene phase where they become chemically bound.
EXAMPLE 14
Example 14 relate to poly(m-xylyleneadipamide), a polymer prepared from equimolar amounts of the two monomers(1) metaxylylene diamine and (2) adipic acid. This polymer is usually referred to as MXD-6. Example 14 was prepared by melt compounding 6 weight percent clay (Rheox) and MXD-6. Subsequent to this compounding step 3 weight percent Poly BD 600 and 100 ppm cobalt were added by methods 2, 3, 5 and 6. This sample exhibited a low oxygen transmission rate, and improved by a factor of 2 (in oxygen transmission rate) relative to comparative example 7, and by a factor of 4 relative to comparative example 6.
EXAMPLES 15-17
Examples 15-17 illustrate the effect of the oxygen binding system on amorphous nylon and blends of nylon and amorphous nylon. Example 15 is a copolymer of this invention containing 97 weight percent amorphous nylon (EMS Grivory G21), 3 weight percent Poly BD 600 and 100 ppm cobalt. Example 16 was prepared as 68 weight percent nylon 6 homopolymer blended with 29 weight percent amorphous nylon, 3 weight percent Poly BD 600 and 100 ppm cobalt (prepared by processes 1, 3, 5 and 6). Example 17 was prepared as 22 weight percent nylon 6, 67 weight percent amorphous nylon, 8 weight percent Nanomer I24TL organoclay, 3 percent Poly BD 600 and 100 ppm cobalt (prepared by processes 1, 3, 5 and 6). Each of these examples exhibited oxygen scavenging and resulted in lower oxygen transmission rates relative to comparative example 8.
EXAMPLES 18-21
Examples 18-21 illustrate the effect of the oxygen binding system on EVOH and blends of nylon and EVOH. Example 18 is a blend containing 70 weight percent nylon 6, and 30 weight percent EVOH. Example 19 was prepared as 70 percent nylon 6/organo-clay blend (containing 6 weight percent Nanocor Nanomer I24T) and 30 weight percent EVOH Example 20 was prepared as 69 weight percent nylon 6, 28 weight percent EVOH and 3 weight percent Poly BD 600/Example 21 was prepared as69 weight percent nylon 6/organo-clay blend (containing 6 weight percent Nanocor Nanomer I24T), 28 weight percent EVOH and 3 weight percent Poly BD 600. Examples 18-21 were prepared by process steps 1, 3, 5 and 6. The samples containing the oxygen scavenging copolymer exhibit oxygen scavenging and resulted in low oxygen transmission rates.
Wt.
Wt. %
OTR
OTR
OTR
Example
Process
%
Nylon
PPM
OTR‡
OTR
OTR
OTR
OTR
OTR
Day
Day
Day
No.
Steps
PBD*
6
Co
Day 1
Day 2
Day 3
Day 4
Day 5
Day 7
10
16
26
Comparative
6
0
100
0
1.7
1.6
1.6
1.6
1.6
N/A
N/A
N/A
N/A
1
Comparative
3,5,6
0
100
100
1.7
1.6
1.6
1.6
1.6
N/A
N/A
N/A
N/A
2
Comparative
2,6
3
97
0
1.9
1.9
1.9
1.9
1.9
1.9
N/A
N/A
N/A
3
Comparative
6
0
100 a
0
0.27
0.29
0.3
0.3
0.3
N/A
N/A
N/A
N/A
4
Comparative
7
0
100 b
0
N/A
N/A
N/A
N/A
N/A
0.24
N/A
N/A
N/A
5
Comparative
6
0
100 c
0
0.18
0.16
0.17
0.17
N/A
N/A
N/A
N/A
N/A
6
Comparative
3,5,6
0
100 c
100
0.067
0.079
0.090
0.082
N/A
N/A
N/A
N/A
N/A
7
Comparative
6
0
100 d
0
0.3
0.3
0.3
0.3
N/A
N/A
N/A
N/A
N/A
8
1
1,3,5,
1
99
100
0.07
0.02
0.25
0.42
N/A
N/A
N/A
N/A
N/A
6
2
1,3,5,
2
98
100
0.02
0.07
0.16
0.28
0.4
0.62
N/A
N/A
6
3
1,3,5,
3
97
100
0
0.0034
0.0086
0.026
0.097
0.54
N/A
N/A
N/A
6
4
2,3,5,
3
97
100
0.0075
0.0069
0.0097
0.034
0.11
0.53
N/A
N/A
N/A
7
5
4,7
3
97
100
0
0.0091
0.046
0.15
0.38
N/A
N/A
N/A
N/A
6
1,3,5,
3
97
100
1.2
0.65
0.027
0.016
0.012
0.018
0.14
N/A
N/A
6
7
1,3,5,
4
96
100
0.0098
0
0.02
0.08
0.17
0.48
0.75
N/A
N/A
6
8
2,3,5,
5††
95
100
0.14
0.68
0.98
1.1
1.3
1.4
N/A
N/A
N/A
7
9
1,3,5,
3
97
100
0.008
0.008
0.008
0.008
0.009
0.01
0.028
N/A
N/A
8
10
1,3,5,
2
98 a
100
0.05
0.0063
0.0063
0.0076
0.007
0.008
N/A
N/A
6
11
1,3,5,
3
97 a
100
0
0
0.00006
0.00026
0.0008
0.002
0.002
N/A
N/A
6
12
1,3,5,
3
77 a ,20 d
100
0.27
0.11
0.0084
N/A
0.010
0.014
0.027
0.042
N/A
6
13
2,3,5,
5
95 b
100
0.044
0.006
0.006
7
14
2 f,3,5,
3
97 c
100
0.014
0.028
0.037
0.040
0.046
0.044
N/A
N/A
N/A
6
Elf Atochem Poly BD 600 (unless otherwise noted)
†Elf Atochem PolyBD605E
††Goodrich Hycar CTB
‡Units cc mil/100 in 2 /atm day, RH = 80-90% unless otherwise noted, Tested in air (21% O 2 ).
To convert to cc mm/m 2 /atm day, multiply by 3.94 × 10 −1 .
a Polymerized nylon6/nanoclay (Nanocor I24TL organoclay)
b Commercially available nylon 6 nanocomposite from Unitika
c Commercially available nylon 6 from MGC (MXD-6)
d Commercially available amorphous nylon from EMS (Grivory G21)
e Commercially available EVOH from EVAL Co.
f 6% Rheox 2355 clay pre-blended in MXD6 prior to process step number 2.
g 8% Nanomer I24TL organoclay added to twin screw extruder during process 1.
The foregoing examples illustrate the effect of the oxygen binding system on the oxygen transmission rate of the inventive nylon composition. While the present invention has been particularly shown and described with reference to preferred embodiments, it will be readily appreciated by those of ordinary skill in the art that various changes and modifications may be made without departing from the spirit and scope of the invention. It is intended that the claims be to interpreted to cover the disclosed embodiment, those alternatives which have been discussed above and all equivalents thereto.
|
Oxygen barrier polyamide compositions exhibiting high oxygen scavenging capability suitable for extended shelf-life packaging applications. Thus a polyamide composition comprises a polyamide homopolymer, copolymer, or blends thereof, and at least one polyamide reactive, oxidizable polydiene or oxidizable polyether. The polyamide products are particularly suited to making barrier packaging articles such as monolayer or multi-layer films, sheets, thermoformed containers and coinjection/coextrusion blow molded bottles comprising PET, polyolefin or polycarbonate as structural layers. Such articles are useful in a variety of oxygen-sensitive food, beverage, pharmaceutical and health care product packaging applications.
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BACKGROUND OF THE INVENTION
[0001] This invention relates to a data arrangement method and a data management system, and more particularly, to a technology of arranging data on a storage system by a computer.
[0002] It is indispensable for corporate activities to utilize a large amount of business data. Therefore, systems for accumulating the large amount of business data in databases (hereinafter, referred to as DBs), and multidimensionally analyzing the accumulated data are widely used.
[0003] In the data analysis processing, a database management system (hereinafter, referred to as DBMS) receives a query, and issues a request to read a large amount of data to a storage system storing the DB.
[0004] If a plurality of storage devices are provided from the storage system to a computer executing the DBMS, a unified storage volume technology for providing a plurality of unified storage devices is known as one of conventional technologies for efficiently processing a large number of data read requests.
[0005] The unified storage volume technology causes an application program (hereinafter, referred to as AP) such as a DBMS or an operating system (hereinafter, referred to as OS) to unify storage devices provided by the storage system. The unified storage volume technology then evenly stripes and arranges a DB on the unified storage devices in a distributed manner, to thereby enable even use of the plurality of storage devices (see A J Lewis, “LVM HOWTO” http://ibiblio.org/pub/Linux/docs/HOWTO/other-formats/pdf/LVM-HOWT O.pdf, for example).
SUMMARY OF THE INVENTION
[0006] In the above-mentioned conventional storage system, instead of directly providing physical storage devices for the computer, a function of virtually providing a logical storage device, which is a combination of physical storage devices, is generally employed.
[0007] The redundant array of independent disks (RAID) function for combining a plurality of physical storage devices within a system, thereby realizing redundancy and an increased speed, is widely employed as a specific virtualization function for the storage system.
[0008] While the storage virtualization function by means of the RAID function is generally used, cases where a plurality of logical storage devices different in configuration of combining physical storage devices are provided for a computer can frequently occur in a real operation.
[0009] On this occasion, the unified storage volume technology evenly distributes and arranges data on the plurality of logical storage devices recognized by the APs and the OS. Therefore, according to this conventional technology, if a plurality of logical storage devices different in the combinational configuration of physical storage devices are provided, there has been a problem that performances of all the physical storage devices cannot be evenly used for a request to access an entire range of the stored data, and the request to read the large amount of data cannot be efficiently processed.
[0010] For example, if a logical storage device A is constituted of four physical storage devices, a logical storage device B is constituted of three physical storage devices, the logical storage device A and the logical storage device B are unified into a logical storage volume X, and the logical storage volume X is provided for a computer by means of the conventional unified storage volume technology in a storage system, the conventional technology evenly distributes the quantity of data read/written by the computer to the logical storage device A and the logical storage device B. If performances of the physical storage devices constituting the logical storage volume X are even, and the logical storage device A and the logical storage device B are constituted by means of the RAID function (RAID 5 in which parities are arranged in a distributed manner, for example), the read/write performance of the logical storage device A exceeds that of the logical storage device B. According to the conventional technology, the same amounts of data are read/written on the logical storage device A and the logical storage device B in the logical storage volume X of the conventional technology. As a result, there has been a problem in that the logical storage device A cannot sufficiently exert the read/write performance due to the obstruction by the read/write performance of the logical storage device B.
[0011] This invention has been made in view of the above-mentioned problem, and therefore has an object to provide a data arrangement method capable of, for providing a computer with a plurality of logical storage devices different in combination of physical storage devices, even use of the physical storage devices constituting the logical storage devices by using the virtualization function of the storage system.
[0012] According to this invention, a data arrangement method, the computer connected to a storage system which provides a plurality of logical storage devices comprising a plurality of physical storage devices arranges data in a logical storage volume constructed by integrating the plurality of logical storage devices. The method includes: a step wherein the computer receives an instruction to construct the logical storage volume using the plurality of logical storage devices or to reconstruct the constructed logical storage volume; a step wherein the computer obtains information about the plurality of physical storage devices constituting each of the plurality of logical storage devices included in the received instruction; and a step wherein the arrangement position of data into the logical storage volume is determined on the basis of the obtained information about the plurality of physical storage devices.
[0013] Therefore, according to the embodiment of this invention, even if the storage system provides a computer with a plurality of logical storage devices different in configuration of combining physical storage devices, arrangement positions of data on the logical storage devices can be determined in accordance with configuration information on the physical storage devices, and the arrangement positions enable even use of the physical storage devices. As a result, efficiency of processing of reading a large amount of data can be increased by utilizing input/output processing performances of all the physical storage devices.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1A is a block diagrams illustrating a hardware configuration and a logical configuration of an information processing system according to the embodiment of this invention.
[0015] FIG. 1B is a block diagrams illustrating a hardware configuration and a logical configuration of an information processing system according to the embodiment of this invention.
[0016] FIG. 2 is a block diagram illustrating a relationship between logical storage devices provided by the storage system according to the embodiment of this invention.
[0017] FIG. 3 is a flowchart illustrating a processing sequence of building a logical storage volume by the data management module of the host computer according to the embodiment of this invention.
[0018] FIG. 4 is an explanatory diagram illustrating an example of the physical storage device information according to the embodiment of this invention.
[0019] FIG. 5 is an explanatory diagram illustrating an example of the data arrangement management information according to the embodiment of this invention.
[0020] FIG. 6 is a screen image illustrating an example of the GUI output to the console by the DBMS management module according to the embodiment of this invention.
[0021] FIG. 7 is a flowchart illustrating a processing sequence of rebuilding, by the data management module of the host computer, a logical storage volume already built according to the embodiment of this invention.
[0022] FIG. 8 is an explanatory diagram illustrating another example of the data arrangement management information according to the embodiment of this invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0023] A description is now given of an embodiment of this invention referring to the accompanying drawings.
<Configuration of Information Processing System>
[0024] FIGS. 1A and 1B are block diagrams illustrating a hardware configuration and a logical configuration of an information processing system according to the embodiment of this invention. A description is first given of the hardware configuration.
[0025] The information processing system illustrated in FIGS. 1A and 1B includes a host computer 1 , a storage system 2 , a storage management terminal 3 , a storage area network (hereinafter, referred to as SAN) 4 , a network (management network) 5 , and a database management terminal 6 .
[0026] The host computer 1 is a computer such as a personal computer, a workstation, or a mainframe. On the host computer 1 , an operating system (hereinafter, referred to as OS) 100 suited to the type of the computer, a database management system (hereinafter, referred to as DBMS) 200 for accumulating and managing business data, and application programs (hereinafter, referred to as APs) 300 for issuing queries to the DBMS 200 operate. The OS 100 , the DBMS 200 , and the APs 300 are described later.
[0027] The host computer 1 includes a processor 12 , a memory 11 , a local storage device 13 , a host bus adapter 15 , and a network adapter 14 .
[0028] The processor 12 executes programs such as the OS 100 , the DBMS 200 , and the APs 300 . The memory 11 temporarily stores programs executed by the processor 12 and data used by the programs. The local storage device 13 functions as a storage medium for storing data used by programs such as the APs 300 and the DBMS 200 , and data used by the programs. The host bus adapter 15 is an interface coupling the SAN 4 and the host computer 1 to each other. The host bus adapter 14 is an interface coupling the network 5 and the host computer 1 to each other.
[0029] It should be noted that the host computer 1 may include a plurality of components such as the processor 12 for securing redundancy. Moreover, the host computer 1 includes an input device and a display device, which are not illustrated.
[0030] The storage system 2 is a system including a single storage device such as a disk device or a plurality of storage devices such as a disk array. Moreover, the storage system 2 stores data and programs used by the host computer 1 . Then, the storage system 2 receives an input/output (hereinafter, referred to as I/O) processing request from the host computer 1 , carries out processing corresponding to the I/O processing request, and transmits a processing result to the host computer 1 .
[0031] The storage system 2 includes a control device 20 , a coupling interface 21 , and physical storage devices 22 a to 22 e. The physical storage devices 22 a to 22 e are generally referred to as physical storage devices 22 in the following description.
[0032] Moreover, the physical storage device 22 stores the data and the programs used by the host computer 1 . The physical storage device 22 is a non-volatile storage device, and is constituted of a hard disk drive including a magnetic disk and a magnetic head, for example. The coupling interface 21 is constituted of a local bus, for example, and couples the physical storage devices 22 and the control device 20 to each other.
[0033] The control device 20 carries out processing of the I/O processing request from the host computer 1 , and control of the physical storage devices 22 . The control device 20 includes a processor 26 , a memory 27 , a physical storage device adapter 23 , a network adapter 24 , and a network adapter 25 .
[0034] The processor 26 executes a predetermined control program. The memory 27 stores programs executed by the processor 26 , information required for executing the programs, and setting information and configuration information on the storage system 2 . The memory 27 further temporality stores data input to the storage system 2 from the host computer 1 , data to be transferred from the storage system 2 to the host computer 1 , or data input/output within the storage system 2 . The memory 27 may be constituted of a non-volatile memory and a cache memory, may store the programs and the configuration information in the non-volatile memory, and may store the input/output data in the cache memory.
[0035] The physical storage device adapter 23 couples to the physical storage devices 22 via the coupling interface 21 . The network adapter 25 couples the storage system 2 and the SAN 4 to each other. The network adapter 24 couples the storage system 2 and the network 5 to each other.
[0036] It should be noted that the storage system 2 may include a plurality of control devices 20 . Moreover, in order to secure redundancy, the storage system 2 may have a redundant configuration in which each of the components within the system such as the memory 27 , the physical storage device adapter 23 , and the coupling interface 21 is duplexed.
[0037] The storage management terminal 3 is a computer for managing the components within the storage system 2 . An administrator of the storage system 2 inputs setting information to the storage management terminal 3 when the administrator manages the components of the storage system 2 . The storage management terminal 3 transmits contents input by the administrator to the storage system 2 via the network 5 .
[0038] The storage management terminal 3 includes a processor 30 , a memory 31 , and a network adapter 32 as the host computer 1 does. The storage management terminal 3 may include a local storage device, which is not illustrated. Moreover, the storage management terminal 3 includes a console 33 including an input device and an output device.
[0039] The database management terminal 6 is a computer for managing the DBMS 200 executed on the host computer 1 . An administrator of the DBMS 200 inputs setting information to the database management terminal 6 when the administrator manages the DBMS 200 of the host compute 1 . The database management terminal 6 transmits contents input by the administrator to the host computer 1 via the network 5 .
[0040] The database management terminal 6 includes a processor 60 , a memory 61 , and a network adapter 62 as the host computer 1 does. The database management terminal 6 may include a local storage device, which is not illustrated. Moreover, the database management terminal 6 includes a console 63 including an input device and an output device.
[0041] The SAN 4 couples the host computer 1 and the storage system 2 to each other, and is used to transmit the I/O processing request from the host computer 1 to the storage system 2 . An optical fiber or a copper wire is used for the SAN 4 . Moreover, a communication protocol such as the Fibre Channel, the small computer system interface (SCSI), or the transmission control protocol/internet protocol (TCP/IP) is used on the SAN 4 .
[0042] The network 5 functions as a management network for the information processing system, and couples the host computer 1 , the storage system 2 , the storage management terminal 3 , and the database management terminal 6 to one another. The network 5 is used to communicate the configuration information on the storage system 2 and the management information on the DBMS 200 of the host computer 1 among the storage system 2 , the host computer 1 , the storage management terminal 3 , and the database management terminal 6 . A cable and a communication protocol used for the network 5 may be the same as those used for the SAN 4 or may be different from those used for the SAN 4 .
<Logical Configuration of Storage System 2 of Information Processing System>
[0043] A description is now given of a logical configuration of the information processing system in FIGS. 1A and 1B . The control device 20 of the storage system 2 stores programs constituting a device management module 28 and a command processing module 29 in the memory 27 in order to control processing by the storage system 2 as illustrated in FIG. 1A . The control device 20 controls processing described later by executing these programs by the processor 26 .
[0044] A program constituting the device management module 28 is executed by the control device 20 for managing physical storage devices 22 and logical storage devices 280 a and 280 b provided for the host computer 1 . It should be noted that, hereinafter, the logical storage devices 280 a and 280 b are generally referred to as logical storage devices 280 .
[0045] The control device 20 executes the device management module 28 to thereby combine the plurality of physical storage devices 22 (illustrated by dotted lines on the memory 27 in FIG. 2 ) into redundant array of independent disks (RAID) groups. By configuring the RAID groups, the storage system 2 can reduce an I/O processing time by means of the striping technology, thereby distributing and storing data to and in the plurality of physical storage devices 22 , and can increase reliability of the data by means of the parity recording technology, which generates a parity of pieces of data located at the same position on at least two physical storage devices, and stores the parity on another physical storage device. The configuration of the RAID group may be the mirroring configuration which simultaneously copies a content of one physical storage device 22 to another physical storage device 22 .
[0046] The control device 20 executes the device management module 28 , thereby providing the host computer 1 with one logical storage device 280 from a storage space generated by the plurality of physical storage devices 22 constituting one RAID group.
[0047] FIG. 2 is a block diagram illustrating a relationship between logical storage devices provided by the storage system 2 for the host computer 1 and physical storage devices. In the example illustrated in FIG. 2 , a logical storage device “a” ( 280 a ) from a RAID group constituted of the physical storage devices 22 a, 22 b, and 22 c, and a logical storage device “b” ( 280 b ) from a RAID group constituted of the physical storage devices 22 d and 22 e are provided for the host computer 1 .
[0048] The control device 20 executes the device management module 28 , thereby managing physical storage device information 281 , which is information on the physical storage devices 22 of the logical storage devices 280 . The physical storage device information 281 is described later in detail referring to FIG. 4 .
[0049] The control device 20 executes the device management module 28 , thereby handling requests from the host computer 1 and the storage management terminal 3 . For example, the device management module 28 defines and sets the logical storage devices 280 , and transmits the physical storage device information 281 in response to a request from the storage management terminal 3 .
[0050] The control device 20 executes the program of the device management module 28 in order to carry out the I/O processing. The device management module 28 calculates, based on the physical storage device information 281 , an address of a physical storage device 22 corresponding to a logical storage device 280 specified by an I/O processing request. The control device 20 makes an access to the physical storage device 22 based on the calculation result.
[0051] Moreover, when the control device 20 receives an I/O processing request from the host computer 1 via the network adapter 24 , the control device 20 executes the program of the command processing module 29 .
[0052] If the I/O processing request received from the host computer 1 is a write processing request for data, the command processing module 29 carries out processing of writing data transferred from the host computer 1 into a predetermined area of the memory 27 or the physical storage device 22 , and the like.
[0053] If the command processing module 29 receives a read processing request for data from the host computer 1 , the command processing module 29 carries out processing of reading data corresponding to the read processing request from a predetermined area of the memory 27 or the physical storage device 22 , and transferring the read data to the host computer 1 , and the like.
[0054] If the control device 20 receives a processing request other than those of reading or writing data from the host computer 1 , the control device 20 operates the command processing module 29 to carry out the requested processing. For example, this request includes an Inquiry command (command of instructing the device search) of the SCSI from the host computer 1 or the storage management terminal 3 .
[0055] The storage system 2 can dynamically change the configuration of the RAID group containing the logical storage device 280 provided for the host computer 1 . As an example of the dynamic configuration change of the RAID group, a RAID group constituted of two physical storage devices is reconstituted with three physical storage devices by adding one physical storage device. The dynamic configuration change of the RAID group is not recognized by the host compute 1 , and is processed in the background.
[0056] When the configuration of the RAID group is dynamically changed, the control device 20 executes the programs of the command processing module 29 and the device management module 28 , thereby carrying out migration processing for data caused by the change.
[0057] The control device 20 executes the command processing module 29 , thereby reading data in the physical storage device 22 of a migration source into the memory 27 , and writes the read data to a physical storage device 22 of a migration destination. Moreover, the control device 20 executes the device management module 28 , thereby applying the change in the physical storage device information 281 caused by the configuration change of the RAID group. It should be noted that the control device 20 can receive an I/O processing request intended for all data including a subject of migration even during the migration of data caused by a dynamic configuration change of the RAID group.
<Software Configurations of Host Computer 1 , Storage Management Terminal 3 , and Database Management Terminal 6 of Information Processing System>
[0058] As illustrated in FIG. 1A , the host computer 1 includes, in the memory 11 and the local storage device 13 , various programs including the OS 100 , the DBMS 200 for accumulating the business data and managing the accumulated business data, and APs 300 for issuing queries to the DBMS 200 , and information required for executing the programs. It should be noted that the AP 300 may be executed on another computer coupled to the network 5 other than the host computer 1 on which the DBMS 200 is running. In this case, the DBMS 200 receives a query from the AP 300 via the network 5 .
[0059] The OS 100 carries out control of the entire computer such as management of the memory 11 and the local storage device 13 . Moreover, the OS 100 of the host computer 1 recognizes the presence of the two logical storage devices 280 a and 280 b provided by the storage system 2 as logical storage devices 280 a ′ and 280 b ′ as illustrated in FIG. 2 . The logical storage devices 280 a ′ and 280 b ′ are generally referred to as logical storage devices 280 ′. The logical storage devices 280 ′ recognized by the DBMS 200 or the OS 100 of the host computer 1 are the same as the logical storage devices 280 provided by the storage system 2 according to this embodiment.
[0060] The DBMS 200 stores and manages a database (hereinafter, referred to as DB) of the business data in the storage system 2 . The DB is stored in the physical storage devices 22 via the logical storage devices 280 a ′ and 280 b ′ recognized by the host computer 1 , and constituted of a plurality of tables and indices.
[0061] The DBMS 200 is constituted of a data management module 210 , a physical storage device information acquisition module 220 , and a query processing module 230 as illustrated in FIG. 1A .
[0062] The data management module 210 unifies the logical storage devices 280 a ′ and 280 b ′ recognized by the OS 100 into a logical storage volume 2800 , and manages the logical storage volume 2800 . The DBMS 200 stores the DB in the logical storage volume 2800 . The data management module 210 builds data arrangement management information 2100 , thereby managing the logical storage volume 2800 . The data arrangement management information 2100 contains a ratio of data distributed to and arranged on (stored in) the plurality of logical storage devices 280 a ′ and 280 b ′ constituting the logical storage volume 2800 . The data arrangement management information 2100 is described later in detail referring to FIG. 5 .
[0063] The physical storage device information acquisition module 220 receives an instruction from the data management module 210 , thereby acquiring the physical storage device information 281 , which is the information on the physical storage devices 22 of the storage system 2 constituting the logical storage devices 280 a ′ and 280 b ′, from the storage system 2 or physical storage device information 311 described later from the storage management terminal 3 , and retains the physical storage device information 281 or the physical storage device information 311 as the physical storage device information 221 . Moreover, the physical storage device information acquisition module 220 provides a dedicated interface, thereby acquiring information from the database management terminal 6 and the like.
[0064] The query processing module 230 receives a query from the AP 300 , carries out a plurality of pieces of database processing in response to the received query, and returns an execution result to the AP 300 . When it becomes necessary to read data from the DB, the query processing module 230 issues a data read request to the storage system 2 via the OS 100 during the execution of the database processing.
[0065] The DBMS 200 can build a database buffer (hereinafter, referred to as DB buffer) for temporarily storing data by using a part of the memory 11 and the local storage device 13 . Moreover, the data management module 210 containing the data arrangement management information 2100 and the physical storage device information acquisition module 220 may operate not within the DBMS 200 but within the OS 100 .
[0066] FIG. 4 is an explanatory diagram illustrating an example of the physical storage device information 281 of the storage system 2 . It should be noted that the physical storage device information 311 of the storage management terminal 3 is the same as the physical storage device information 281 of the storage system 2 , and the physical storage device information 221 of the DBMS 200 is the same as a table formed by removing a logical storage device number 402 described later from the physical storage device information 281 of the storage system 2 , and hence duplicate description thereof is omitted.
[0067] Columns of the physical storage device information 281 are respectively a host logical storage device number 401 for storing the number of a logical storage device provided for the host computer 1 by the storage system 2 , the logical storage device number 402 for storing the number of the logical storage device as an identifier internally managed by the storage system 2 , a logical storage device capacity 403 for storing a storage capacity of the logical storage device corresponding to the logical storage device number, a RAID group number 404 for storing a RAID group identifier of the logical storage device, a RAID level 405 for storing the RAID level (type) of the logical storage device, a physical storage device number 406 for storing identifiers of a plurality of physical storage devices 22 constituting the RAID group, and a physical storage device type 407 for storing types of the respective physical storage devices 22 .
[0068] The host logical storage device number 401 is an identifier allocated to a logical storage device provided for the host computer 1 by the device management module 28 of the storage system 2 . The DBMS 200 and the OS 100 identify a logical storage device provided by the storage system 2 by the host logical storage device number 401 . The logical storage device number 402 to the logical storage device type 407 are information on the logical storage device 280 and the physical storage devices 22 set by the device management module 28 of the storage system 2 .
[0069] The logical storage device number 402 is an identifier of the logical storage device set by the storage system 2 . The logical storage device capacity 403 is the capacity of the logical storage device provided for the host computer 1 by the storage system 2 .
[0070] The RAID group number 404 and the RAID level 405 are information on the RAID configuration of the logical storage device, and are managed by the storage system 2 . The RAID level 405 stores the type of the RAID such as 0 , 10 , 5 , and 6 . The physical storage device number 406 stores identifiers of the plurality of physical storage devices 22 which are managed by the storage system 2 and constitute the RAID group.
[0071] The physical storage device type 407 stores types of the plurality of physical storage devices 22 constituting the RAID group indicated by the RAID group number 404 , and stores types of interface such as FC, SATA, and SAS as the types.
[0072] In addition to the above-mentioned examples, information manageable by the device management module 28 of the storage system 2 may be included in the physical storage device information 221 , and the seek time and the rotation speed of the physical storage devices 22 , for example, may be stored as performance information.
[0073] As described above, the host computer 1 using the storage system 2 can recognize the RAID configuration and the physical storage devices 22 of the logical storage devices 280 ( 280 ′) by forwarding the physical storage device information 281 managed by the device management module 28 of the storage system 2 to the physical storage device information 221 of the DBMS 200 of the host computer 1 or to the physical storage device information 311 of the storage management terminal 3 .
[0074] FIG. 5 is an explanatory diagram illustrating an example of the data arrangement management information 2100 managed by the data management module 210 of the DBMS 200 .
[0075] Columns of the data arrangement management information 2100 are respectively a logical storage volume name 2101 for storing a name of a logical storage volume managed by the DBMS 200 (or OS 100 ), a logical storage volume number 2102 for storing an identifier of the logical storage volume managed by the DBMS 200 (or OS 100 ), a logical storage volume capacity 2103 for storing a capacity of the logical storage volume, a host logical storage device number 2104 for storing identifiers of logical storage devices constituting the logical storage volume, a data arrangement ratio 2105 for storing a ratio for distributing the data to the logical storage devices by the data management module 210 , and a stripe size 2106 for storing a unit of the data (stripe size) to be distributed to the logical storage devices by the data management module 210 .
[0076] The logical storage volume 2800 is constituted of a plurality of logical storage devices 280 , and the host logical storage device number 2104 of the data arrangement management information 2100 stores the host logical storage device numbers 401 of the host logical storage devices constituting the logical storage volume 2800 out of the host logical storage devices identified by the host logical storage device numbers 401 illustrated in FIG. 4 .
[0077] The data arrangement ratio 2105 is set by the data management module 210 , and stores a ratio of data to be read/written (to be allocated) on the logical storage devices identified by the host logical storage device number 2104 . The host logical storage device number 2104 stores “ 101 ” and “ 102 ” as illustrated, and if the data arrangement ratio 2105 is “3:2”, it means that the data is arranged at the ratio of “3” (3/5) on the logical storage device having the host logical storage device number 2104 of “ 101 ” to “2” (2/5) on the logical storage device having the host logical storage device number 2104 of “ 102 ”. Moreover, the stripe size 2106 is also a value set by the data management module 210 .
[0078] Referring again to FIG. 1B , the storage management terminal 3 stores a program of a storage management module 310 and information required for executing the program in the memory 31 and the local storage device (not shown). The storage management terminal 3 may include an OS, which is not illustrated, for controlling the computer.
[0079] The storage management module 310 manages a configuration of the storage system 2 . Moreover, the storage management module 310 acquires, from the storage system 2 , and stores the physical storage device information 311 on the physical storage devices 22 constituting the logical storage devices 280 in the storage system 2 . The physical storage device information 311 is the same as the physical storage device information 281 existing on the device management module 28 of the storage system 2 . The storage management module 310 updates the physical storage device information 311 periodically or when the physical storage device information 281 is updated, thereby synchronizing this information with that in the storage system 2 .
[0080] The database management terminal 6 then stores a program for managing a DBMS management module 610 and information required for executing the program in the memory 61 and the local storage device (not shown). The database management terminal 6 may include an OS, which is not illustrated, for controlling the computer.
[0081] The DBMS management module 610 manages the DBMS 200 of the host computer 1 . The DBMS management module 610 determines a configuration of the logical storage volume 2800 from/to which the DBMS 200 of the host computer 1 reads/writes the business data, and instructs the DBMS 200 of the host computer 1 to provide the configuration, thereby managing the DBMS 200 , for example.
[0082] In order for that, the DBMS management module 610 outputs a graphical user interface (GUI) to the display device of the console 63 as illustrated in FIG. 6 as described later, thereby receiving an input from the administrator. The DBMS management module 610 receives from the input device of the console 63 an instruction to build the logical storage volume 2800 using the plurality of the logical storage devices 280 a ′ and 280 b ′, or an instruction to rebuild the logical storage volume 2800 already built. The DBMS management module 610 then transmits the received instruction to build or rebuild the logical storage volume 2800 to the DBMS 200 of the host computer 1 .
[0083] FIG. 6 is a screen image illustrating an example of the GUI output to the console 63 by the DBMS management module 610 of the database management terminal 6 . The screen in FIG. 6 is a user interface for building a logical storage volume, and is provided by the DBMS 200 to the database management terminal 6 . It should be noted that the DBMS 200 can provide the host computer 1 and other computers including a display device with the GUI in FIG. 6 . It should be noted that the DBMS 200 can provide an equivalent interface in a form of the command line.
[0084] A database (DB) administrator for managing the DBMS 200 of the host computer 1 uses this screen on the database management terminal 6 to control the DBMS 200 to acquire the physical storage device information and to build the logical storage volume.
[0085] In FIG. 6 , a window 64 is mainly constituted of fields 641 to 643 for storing specifications of the logical storage volume to be built by the data management module 210 , checkboxes 645 to 647 for selecting destinations from which the physical storage device information is acquired, and a build execution button 648 for instructing to start building (or rebuilding) the logical storage volume 2800 .
[0086] The field 641 stores a name of the logical storage volume 2800 to be built by the data management module 210 . The field 642 stores the capacity of the logical storage volume 2800 . The filed 643 stores identifiers (numbers) of logical storage devices 280 ′ to be allocated to the logical storage volume 2800 . The identifier of the logical storage device 280 ′ may be selected from the host logical storage device number 401 of the physical storage device information 281 illustrated in FIG. 4 .
[0087] If the administrator then selects the checkbox 645 for selecting the destination from which the physical storage device information is acquired, this selection indicates that the information on the physical storage devices is to be acquired from the physical storage device information 281 of the storage system 2 . If the administrator selects the checkbox 646 , this selection indicates that the information on the physical storage devices is to be acquired from the physical storage device information 331 of the storage management terminal 3 . If the administrator selects the checkbox 647 , values input to fields 6471 to 6475 from the console 63 are to be used as information on the physical storage devices as described later.
[0088] If the administrator selects any one of the check boxes 645 and 646 , the administrator selects a criterion for determining a data arrangement ratio, which is a ratio of data arranged by means of the striping on the plurality of logical storage devices 280 ′, using any one of checkboxes 6461 to 6464 .
[0089] If the administrator selects the checkbox 6461 , the selection indicates that the data arrangement ratio is to be determined based on the number of the physical storage devices 22 constituting the logical storage devices 280 ′. If the administrator selects the checkbox 6462 , the selection indicates that the data arrangement ratio is to be determined based on information on the RAID of the logical storage devices 280 ′ (such as the level of the RAID). If the administrator selects the checkbox 6463 , the selection indicates that the data arrangement ratio is to be determined based on performance information on the physical storage devices 22 (information affecting the throughput such as the type of interface) constituting the logical storage devices 280 ′. If the administrator selects the checkbox 6464 , the selection indicates that the data arrangement ratio is to be determined based on capacities of the logical storage devices 280 ′.
[0090] If the administrator selects the checkbox 647 , the administrator is required to input information on the logical storage devices 280 ′ in the fields 6471 to 6475 .
[0091] The field 6471 stores the number of the physical storage devices 22 constituting the logical storage devices 280 ′. The field 6472 stores identifiers of RAID groups of the logical storage devices 280 ′. It should be noted that the administrator can refer to the RAID group number 404 of the physical storage device information 281 in FIG. 4 for inputting the identification numbers of the RAID groups. The field 6473 stores the levels of RAID. The administrator can refer to the values of the RAID level 405 of the physical storage device information 281 illustrated in FIG. 4 for inputting the RAID level.
[0092] The field 6474 stores the types of the physical storage devices 22 . The administrator can refer to the values of the physical storage device type 407 of the physical storage device information 281 in FIG. 4 for inputting the types of the physical storage devices 22 . The field 6475 stores the capacity of the logical storage devices 280 ′. The administrator can refer to the logical storage device capacity 403 of the physical storage device information 281 in FIG. 4 for inputting the capacity of the logical storage devices 280 ′.
[0093] After the corresponding information is set to the specifications and the checkboxes 645 to 647 of the logical storage volume 2800 , when the administrator clicks the building execution button 648 , the database management terminal 6 transmits a building instruction of the logical storage volume 2800 to the host computer 1 . The building instruction contains the values of the checkboxes and the fields input on the window 64 . The DBMS 200 of the host computer 1 builds the logical storage volume 2800 based on the building instruction.
[0094] If the number of the physical storage devices, the RAID group information (identification information and RAID levels), and the performance information (physical storage device types) are specified (acquired or input), this embodiment arranges the data so that the performance of the physical storage devices is maximally utilized. On the other hand, if the capacities of the host storage devices are specified (acquired or input), the data is arranged depending on the capacities of the respective host storage devices.
<Processing Overview>
[0095] The configuration of this embodiment of this invention has been described. A description is now given of the processing of this embodiment of this invention. When the data management module 210 of the host computer 1 receives the instruction to build the logical storage volume 2800 or the instruction to rebuild the logical storage volume 2800 already built from the database management terminal 6 , the data management module 210 outputs an instruction to update the physical storage device information 221 to the physical storage device information acquisition module 220 . The physical storage device information acquisition module 220 issues a transmission instruction of the physical storage device information to the storage management terminal 3 or the storage system 2 .
[0096] A description is now given of a case in which the instruction to build the logical storage volume 2800 or the instruction to rebuild the logical storage volume 2800 is transmitted from the database management terminal 6 according to this embodiment. However, a computer other than the database management terminal 6 may transmit the instruction to build or the instruction to rebuild the logical storage volume 2800 , or the instruction may be received from a console, which is not shown, of the host computer 1 . Moreover, the physical storage device information acquisition module 220 of the DBMS 200 may acquire the physical storage device information 311 of the storage management terminal 3 or the physical storage device information 281 of the storage system 2 at a predetermined cycle, thereby updating the physical storage device information 221 .
[0097] The physical storage device acquisition module 220 acquires the physical storage device information 281 (or 311 ) via the storage system 2 , the storage management terminal 3 , or the dedicated interface, thereby updating the physical storage device information 221 in the memory 11 .
[0098] The data management module 210 determines, as the data arrangement ratio, the ratio of data arranged on the plurality of logical storage devices 280 a ′ and 280 b ′ constituting the logical storage volume 2800 by means of the striping based on the physical storage device information 221 acquired by the physical storage device information acquisition module 220 as described later. The data management module 210 updates the data arrangement management information 2100 regarding the determined data arrangement ratio, and defines the logical storage volume 2800 based on the data arrangement management information 2100 .
[0099] For example, in the case of FIG. 2 , the physical storage device information which the host computer 1 can acquire from the storage system 2 is information indicating that the number of the physical storage devices 22 constituting the logical storage device 280 a ′ is three ( 22 a, 22 b, and 22 c ) and the number of the physical storage devices 22 constituting the logical storage device 280 b ′ is two ( 22 d and 22 e ).
[0100] When the data management module 210 evenly arranges data on physical storage devices 22 different from one another, the ratio of data distributed to and arranged on the logical storage devices 280 a ′ and 280 b ′ is determined to 3:2 in proportion to the numbers of the physical storage devices 22 , and the ratio is set to the data arrangement ratio 2105 of the data arrangement management information 2100 . The data arrangement ratio represents a ratio of data quantity for distributing data to the plurality of logical storage devices 280 ′.
[0101] The data management module 210 then divides data received from the query processing module 230 into a plurality of management units having a predetermined size (such as the stripe size) and distributes the data to the logical storage devices 280 a ′ and 280 b ′ in accordance with the data arrangement ratio.
[0102] In other words, the data management module 210 divides the data received from the query processing module 230 into the predetermined management units such as management units “ 1 ” to “ 5 ” (“ 1 ” to “n” denote data management units of the logical storage volume 2800 ) and stores “ 1 ”, “ 3 ”, and “ 5 ” in the logical storage device 280 a ′ and stores “ 2 ” and “ 4 ” in the logical storage device 280 b ′ in accordance with the data arrangement ratio of 3:2 indicated by the data arrangement management information 2100 , thereby arranging the data in the distributed manner.
[0103] For the following data “ 6 ” to “ 10 ”, the data management module 210 also arranges striped data to the plurality of logical storage devices 280 at the same ratio. It should be noted that the management unit treated by the data management module 210 may be the same as or different from a data quantity of a data block read/written from/to the logical storage devices 280 ′.
[0104] As a result, when the logical storage volume 2800 is built by unifying the plurality of logical storage devices 280 different in combination or configuration of physical storage devices 22 , the DBMS 200 can evenly use the physical storage devices 22 of the storage system 2 in accordance with the physical storage device information 221 , thereby maximally utilizing the input/output processing performance of all the physical storage devices 22 .
<Processing in Detail>
[0105] A detailed description is now given of the processing of this embodiment of this invention. FIG. 3 is a flowchart illustrating a processing sequence of building a logical storage volume 2800 by the data management module 210 of the host computer 1 according to the embodiment of this invention. This processing is executed when the data management module 210 receives the instruction to build the logical storage volume 2800 from the database management terminal 6 . It should be noted that the rebuilding instruction is described later referring to FIG. 7 .
[0106] First, the data management module 210 receives the instruction to build the logical storage volume 2800 from the database management terminal 6 in Step S 1 . This building instruction contains the information received on the GUI in FIG. 6 . It should be noted that the instruction to build or the instruction to rebuild the logical storage volume 2800 may be received from a console (not shown) of the host computer 1 .
[0107] The data management module 210 instructs the physical storage device information acquisition module 220 to update the physical storage device information 221 in Step S 2 . The physical storage device information acquisition module 220 acquires, based on the instruction, the physical storage device information 281 or 311 on physical storage devices 22 which are components of logical storage devices 280 ′ contained in the building instruction from the storage system 2 or the storage management terminal 3 , thereby updating the physical storage device information 221 on the memory 11 .
[0108] In Step S 3 , if a plurality of logical storage devices 280 ′ are contained in the building instruction, the data management module 210 determines whether or not the physical configurations of the physical storage devices 22 constituting each of the logical storage devices 280 ′ are the same.
[0109] This determination is based on the determination criterion for the physical configuration received by the database management terminal 6 on the GUI in FIG. 6 . The determination criterion for the physical configuration is any one of the checkboxes 6461 to 6464 in FIG. 6 . The checkboxes 6461 to 6464 respectively represent the different items in information on the plurality of physical storage devices 22 .
[0110] In this embodiment, if the checkbox 6461 is selected, the number of the physical storage devices 22 constituting the logical storage devices 280 is used as the determination criterion for the physical configuration. If the checkbox 6462 is selected, the RAID group (or RAID level) constituting the logical storage devices 280 is used as the determination criterion for the physical configuration.
[0111] If the checkbox 6463 is selected, the performance information of the physical storage devices 22 constituting the logical storage devices 280 is used as the determination criterion for the physical configuration. If the checkbox 6464 is selected, the capacity of the logical storage devices 280 is used as the determination criterion for the physical configuration. The performance information of the physical storage devices 22 may be the types of interface (FC, SCSI, SATA, and SAS) stored in the physical storage device type 407 of FIG. 4 , but the performance information may instead be the seek time, the rpm, or the capacities of the physical storage devices 22 .
[0112] The data management module 210 proceeds to Step S 4 if a determination result is that the physical configurations of the plurality of the logical storage devices 280 ′ are not the same. On the other hand, the data management module 210 proceeds to Step S 5 if they are the same.
[0113] In Step S 4 , the data management module 210 warns the database management terminal 6 that the logical storage volume 2800 to be built is formed by unifying the plurality of logical storage devices 280 ′ different in the physical configuration. The database management terminal 6 displays the warning (notification) from the data management module 210 of the host computer 1 on the console 63 . On this occasion, a DB administrator or the like may transmit an instruction to stop building the logical storage volume 2800 from the console 63 to the host computer 1 , and if the data management module 210 receives the stopping instruction, the data management module 210 can finish the building of the logical storage volume 2800 .
[0114] In Step S 5 , the data management module 210 determines the data arrangement ratio, which is the ratio of the data arranged on the plurality of the logical storage devices 280 ′ by means of the striping, based on the criterion for the physical configuration contained in the building instruction input on the GUI in FIG. 6 . The data arrangement ratio is determined depending on the difference in the criterion for the physical configuration as follows.
[0115] The data arrangement ratio can be determined in accordance with the physical configuration of the physical storage devices 22 constituting the logical storage devices 280 ′ for the following cases (1) to (4), for example.
[0000] (1) Data Arrangement Ratio Determined in Accordance with the Number of Physical Storage Devices 22
[0116] The number of the physical storage devices 22 constituting the logical storage device 280 is used as the criterion for the data arrangement ratio. For example, when respective numbers of physical storage devices 22 of logical storage devices A, B, and C are different, and when the number of the physical storage devices 22 of the logical storage device A is 4, the number of the physical storage devices 22 of the logical storage device B is 3, and the number of the physical storage devices 22 of the logical storage device C is 2, the data management module 210 determines the data arrangement ratio as 4:3:2.
[0117] In other words, if the total number of the physical storage devices 22 constituting the logical storage volume 2800 is n, and the number of the physical storage devices 22 in the logical storage device 280 ′ is x, the distribution ratio to this logical storage device 280 ′ is represented as x/n.
[0000] (2) Data Arrangement Ratio Determined in Accordance with RAID Levels of Logical Storage Devices
[0118] The logical storage devices have the RAID configurations. The data management module 210 acquires the number of physical storage devices 22 accessible from the host computer 1 and determines the data arrangement ratio in accordance with this number and the RAID levels. For example, if the logical storage device A is configured by means of the RAID 5 and has three physical storage devices 22 , the logical storage device B is configured by means of the RAID 1 and has two physical storage devices 22 , and the logical storage device C is configured by means of the RAID 0 and has two physical storage devices 22 , in which a physical storage device for mirroring of the RAID 1 is not accessible from the host computer 1 , then the data arrangement ratio is thus determined as 3:1:2 in accordance with the numbers of the physical storage devices 22 excluding the inaccessible physical storage device.
[0119] In other words, if the total number of the physical storage devices 22 accessible from the host computer 1 in the logical storage devices 280 ′ constituting the logical storage volume 2800 is n and the number of the physical devices 22 accessible from the host computer 1 in a logical storage device 280 ′ is x, the distribution ratio to this logical storage device 280 ′ is represented as x/n.
[0000] (3) Data Arrangement Ratio Determined in Accordance with Performance Information on Physical Storage Devices
[0120] If the data arrangement ratio is determined in accordance with the performance information on the physical storage devices 22 , the data management module 210 determines the data arrangement ratio in accordance with the physical storage device type 407 . For example, the data arrangement ratio is determined in accordance with the transfer rate (theoretical value) of the physical storage device type 407 such as 3 for the FC, 2 for the SAS, and 2 for the SATA in the physical storage device type 407 .
[0121] In other words, the data management module 210 sets a value x for each of the physical storage device types 407 in advance. If the total of the values x of the respective logical storage devices 280 ′ constituting the logical storage volume 2800 is X, the distribution ratio of each of the logical storage devices 280 ′ is represented as x/X.
[0000] (4) Data Arrangement Ratio Determined in Accordance with Capacities of Logical Storage Devices
[0122] If the data arrangement ratio is determined in accordance with the capacities of the logical storage devices, the data management module 210 determines the data arrangement ratio in accordance with the capacities of the respective logical storage devices, thereby using the capacities of the respective logical storage devices without waste. For example, if the capacity of the logical storage device A is 2 TB, the capacity of the logical storage device B is 1 TB, and the capacity of the logical storage device C is 500 GB, the data arrangement ratio determined in accordance with a capacity ratio is 4:2:1.
[0123] In other words, the total of the capacities of the logical storage devices 280 ′ constituting the logical storage volume 2800 is X and the capacity of the each of the logical storage devices 280 ′ is Y, the distribution ratio of each of the logical storage devices 280 ′ is represented as Y/X.
[0124] In other words, processing in Step S 5 is processing of determining in which logical storage device 280 ′ write data to be received from the query processing module 230 is stored in accordance with the data arrangement ratio and processing determining distributed locations of the data.
[0125] In Step S 6 , the data management module 210 stores the information input in FIG. 6 and the data arrangement ratio determined in Step S 5 in the data arrangement management information 2100 .
[0126] Specifically, the data management module 210 sets the name input to the logical storage volume name 641 on the GUI in FIG. 6 to the logical storage volume name 2101 of the data arrangement management information 2100 in FIG. 5 , sets the logical storage devices specified in the logical storage device number 643 to the host logical storage device number 2104 of the data arrangement management information 2100 , sets the capacity specified in the logical storage volume capacity 642 to the logical storage volume capacity 2103 of the data arrangement management information 2100 , sets the data arrangement ratio determined in Step S 5 to the data arrangement ratio 2105 of the data arrangement management information 2100 , and sets a value set in advance to the stripe size 2106 of the data arrangement management information 2100 , thereby building the new logical storage volume 2800 .
[0127] In Step S 7 , the data management module 210 defines the logical storage volume 2800 constituted of the plurality of the logical storage devices 280 ′ based on the updated data arrangement management information 2100 , and provides the query processing module 230 with the logical storage volume 2800 .
[0128] When the above-mentioned processing has been completed, if a write request or a read request is issued from the query processing module 230 to the logical storage volume 2800 , the data management module 210 writes/reads data to/from the plurality of the logical storage devices 280 ′ constituting the logical storage volume 2800 in accordance with the data arrangement ratio 2105 corresponding to the configuration and combination of the physical storage devices 22 .
[0129] As described above, the logical storage volume 2800 instructed by the DB administrator from the database management terminal 6 is built for the host computer 1 , and the data arrangement ratio 2105 is determined by the data management module 210 of the DBMS 200 corresponding to the configuration and combination of the physical storage devices 22 .
[0130] If the query processing module 230 of the DBMS 200 issues a write request to the logical storage volume 2800 , the data management module 210 divides data received from the query processing module 230 into the predetermined management units, and writes the divided pieces of data respectively to the logical storage devices 280 a ′ and 280 b ′ in accordance with the data arrangement ratio 2105 .
[0131] For example, if the logical storage device 280 a ′ is constituted of the three physical storage devices 22 a, 22 b, and 22 c, and the logical storage device 280 b ′ is constituted of the two physical storage devices 22 d and 22 e as illustrated in FIG. 2 , and the checkbox 6461 “NUMBER OF PHYSICAL STORAGE DEVICES” is selected on the GUI of FIG. 6 , the data management module 210 determines the data arrangement ratio of 3:2 in accordance with the numbers of the physical storage devices 22 a - 22 e, and sets the data arrangement ratio to the data arrangement management information 2100 .
[0132] When the data management module 210 receives the data to be written from the query processing module 230 , the data management module 210 divides the received data in accordance with the predetermined management unit (stripe size according to this embodiment), thus divides the received data into the management units “ 1 ”-“ 5 ” (hereinafter, referred to as stripes) as illustrated in FIG. 2 , for example. The data management module 210 then allocates the divided pieces of data “ 1 ”-“ 5 ” by means of the round robin in accordance with the data arrangement ratio 2105 to the logical storage device 280 a ′ and the logical storage device 280 b′.
[0133] As a result, the pieces of data “ 1 ”, “ 3 ”, and “ 5 ” are allocated to the logical storage device 280 a ′ having the three physical storage devices 22 , and the pieces of data “ 2 ” and “ 4 ” are allocated to the logical storage device 280 b ′ having the two physical storage devices 22 , and those pieces of data are written to the respective logical storage devices 280 ′. The pieces of data are written in parallel to the plurality of physical storage devices 22 in each of the logical storage devices 280 ′. It should be noted that the read processing is inverse to the above-mentioned processing, and the logical storage devices 280 ′ carry out reading in units of the stripe size in parallel from the physical storage devices 22 .
[0134] On the other hand, the conventional technology evenly distributes the data to those two logical storage devices 280 a ′ and 280 b ′ without referring to the physical configurations of the physical storage devices 22 constituting the logical storage devices 280 a ′ and 280 b ′. Therefore, according to the conventional technology, compared with the read/write speeds from/to the logical storage device 280 a ′ constituted of the three physical storage devices 22 , the read/write speeds from/to the logical storage device 280 b ′ constituted of the two physical storage devices 22 are low. Therefore, in terms of the read/write performance of the logical storage volume 2800 , the logical storage device 280 b ′, which is slow in speed, constitutes a bottle neck, and the performance of the physical storage devices 22 of the logical storage device 280 a ′ becomes excessive.
[0135] On the other hand, according to this invention, the data arrangement ratio 2105 for each of the logical storage devices 280 ′ is determined in accordance with the physical configurations of the physical storage devices 22 constituting the logical storage devices 280 ′, and hence the read/write speeds for each of the logical storage devices 280 ′ can be equalized, thereby maximizing the read/write performance of the logical storage volume 2800 .
[0136] As described above, if a logical storage volume 2800 constituted of a plurality of logical storage devices 280 different in physical configuration using the virtualization function of the storage system is provided for the computer, the data management module 210 according to this invention can set the data arrangement ratio for the plurality of the logical storage devices 280 for maximally using the performance of the physical storage devices 22 , thereby using the performance of each of the physical storage devices 22 without waste.
[0137] FIG. 7 is a flowchart illustrating a processing sequence of rebuilding, by the data management module 210 of the host computer 1 , a logical storage volume 2800 already built according to the embodiment of this invention. In Step S 11 of the processing flow, if any one of the following events occurs, the data management module 210 receives the event as an instruction for rebuilding, and starts rebuilding of the logical storage volume 2800 already built.
[0138] A first event is an instruction received from the database management terminal 6 in order to add a logical storage device 280 to the logical storage volume 2800 . If the DBMS 200 receives the instruction to add the new logical storage device 280 to the existing logical storage volume 2800 from the database management terminal 6 , the data management module 210 executes processing starting from Step S 12 .
[0139] A second event is an instruction received from the database management terminal 6 in order to remove a logical storage device 280 from the logical storage volume 2800 . If the DBMS 200 receives the instruction to remove the logical storage device 280 from the existing logical storage volume 2800 from the database management terminal 6 , the data management module 210 executes processing starting from Step S 12 .
[0140] A third event is an instruction received from the database management terminal 6 in order to change the capacity of the logical storage volume 2800 . If the DBMS 200 receives the instruction to change the capacity of the existing logical storage volume 2800 from the database management terminal 6 , the data management module 210 executes processing starting from Step S 12 .
[0141] A fourth event is a notification received from the storage system 2 or the storage management terminal 3 indicating a change in configuration of a logical storage device 280 . If the DBMS 200 or the DBMS management module 610 receives a notification from the storage system 2 or the storage management terminal 3 indicating a change in configuration of a logical storage device 280 ′ constituting the existing logical storage volume 2800 , the database management module 210 executes processing starting from Step S 12 .
[0142] A fifth event is an event instructing the DBMS 200 to periodically activate the data management module 210 to start the processing starting from Step S 12 . Each time the predetermined period elapses, the DBMS 200 controls the data management module 210 to execute the processing starting from Step S 12 of FIG. 7 , thereby monitoring a change such as addition or removal of a physical storage device 22 constituting a logical storage device 280 being used by the logical storage volume 2800 .
[0143] In Step S 12 , the data management module 210 determines whether or not the data management module 210 has been activated as a result of the fifth event. If the data management module 210 determines that the data management module 210 has been activated as a result of the fifth event (elapse of predetermined period), the data management module 210 monitors a change in configuration of the logical storage devices 280 ′ constituting the logical storage volume 2800 in Steps S 15 and S 16 .
[0144] In Step S 15 , the data management module 210 instructs the physical storage device information acquisition module 220 to acquire the physical storage device information 281 or 311 from the storage system 2 or the storage management terminal 3 . It should be noted that the physical storage device information acquisition module 220 may acquire the physical storage device information from a preset one out of the storage system 2 and the storage management terminal 3 .
[0145] In Step S 16 , the data management module 210 compares the physical storage device information 221 to the physical storage device information 281 or 331 acquired by the physical storage device information acquisition module 220 from the storage system 2 or the storage management terminal 3 , thereby determining whether or not the both pieces of the physical configuration information on the physical storage devices 22 are the same. If the physical storage device information 281 or 331 and the physical storage device information 221 are the same, the data management module 210 determines that there is no change in the physical storage devices 22 constituting the logical storage devices 280 ′, and finishes the processing.
[0146] On the other hand, if the acquired physical storage device information and the physical storage device information 221 held by the DBMS 200 are not the same, the physical configuration of the logical storage device 280 ′ has changed, and the data management module 210 proceeds to Step S 17 .
[0147] If it is then determined in Step S 12 that the event that has occurred is an event other than the fifth event, in Step S 13 , the data management module 210 determines whether the generated event is the first event (addition of a logical storage device 280 to the logical storage volume 2800 ). If the event that has occurred is the first event, the data management module 210 proceeds to Step S 14 , acquires information on physical storage devices 22 constituting the logical storage device 280 to be added, and proceeds to Step S 17 . On the other hand, if the event that has occurred is not the first event (occurrence of second to fourth events), the database management module 210 directly proceeds to Step S 17 .
[0148] In Step S 17 , the data management module 210 then refers to the physical storage device information 221 , thereby acquiring information on physical storage devices 22 constituting logical storage devices 280 ′ contained in the logical storage volume 2800 already built.
[0149] On this occasion, if the event that has occurred is the first event, and types of the physical storage devices constituting the logical storage device to be added to the logical storage volume 2800 and the types of the physical storage devices 22 constituting the logical storage devices 280 ′ of the existing the logical storage volume 2800 are different, the data management module 210 may output a warning (notification) that the physical configuration of the logical storage device to be added is different from those of the existing logical storage devices to the database management terminal 6 or another terminal. This can prevent the administrator from combining logical storage devices different in physical configuration by mistake, thereby configuring the logical storage volume 2800 .
[0150] Further, the data management module 210 may output the warning (notification) that the physical configuration is different from those of the existing logical storage devices to the database management terminal 6 , and may then receive an instruction to stop rebuilding the logical storage volume 2800 from the database management terminal 6 . The data management module 210 stops the processing if the data management module 210 receives the instruction to stop rebuilding the logical storage volume 2800 .
[0151] In Step S 18 , as in Step S 5 of FIG. 3 , the database management module 210 calculates the data arrangement ratio based on the physical configuration of the plurality of logical storage devices 280 ′ constituting the logical storage volume 2800 . The criteria for the physical storage device 22 in order to determine the data arrangement ratio are the same as (1)-(4) described in Step S 5 , and the data management module 210 acquires the data arrangement ratio in accordance with any one of these criteria.
[0152] In Step S 19 , as in Step S 6 of FIG. 3 , the data management module 210 then stores the information specified by the instruction for rebuilding and the data arrangement ratio determined in Step S 18 in the data arrangement management information 2100 , thereby updating the data arrangement management information 2100 .
[0153] In Step S 20 , as in Step S 7 of FIG. 3 , the data management module 210 rebuilds (redefines) the logical storage volume 2800 constituted of the plurality of the logical storage devices 280 ′ based on the updated data arrangement management information 2100 , and provides the query processing module 230 with the logical storage volume 2800 .
[0154] The data management module 210 then rearranges the data in accordance with the new data arrangement ratio 2105 for the added logical storage device 280 ′ or the removed logical storage device 280 ′. If a physical storage device is added to the logical storage device 280 b in the example of FIG. 2 , for example, the data arrangement ratio is updated from 3:2 to 1:1. The data management module 210 controls the data in the logical storage device 280 a ′ and the logical storage device 280 b ′ to migrate to corresponding logical storage devices 280 ′ for attaining the new ratio.
[0155] When the above-mentioned processing has been completed, if a write request or a read request is issued from the query processing module 230 to the logical storage volume 2800 , the data management module 210 writes/reads data to/from the plurality of the logical storage devices 280 ′ constituting the rebuilt logical storage volume 2800 in accordance with the data arrangement ratio corresponding to the configuration and combination of the physical storage devices 22 .
[0156] As described above, the data arrangement ratio 2105 is determined by the data management module 210 of the DBMS 200 corresponding to the physical configuration and the combination of the physical storage devices 22 also for rebuilding the logical storage volume 2800 . As a result, the read/write speeds for the respective logical storage devices 280 can be equalized, thereby maximizing the read/write performance of the logical storage volume 2800 .
[0157] It should be noted that, though the DBMS 200 includes the data management module 210 for determining the data arrangement ratio, and distributing the data to the logical storage devices 280 in the above-mentioned example, the data management module 210 may be provided in the OS 100 of the host computer 1 .
[0158] Moreover, the logical storage volume 2800 to be provided for the query processing module 230 of the DBMS 200 is constituted using a plurality of logical storage devices 280 ′ recognized by the OS 100 of the host computer 1 in the above-mentioned preferred configuration example. This embodiment is not limited to this configuration, and a logical storage space may be constituted using a plurality of logical storage devices 280 of the storage system 2 recognized by the host computer 1 , a logical storage volume 2800 may be built in the logical storage space, a data arrangement ratio may be determined in accordance with the physical configuration of the logical storage devices 280 as described above, and the data may be distributed, and arranged (stored).
[0159] Moreover, if the RAID 5 or 6 is applied to the host computer 1 by means of software, the parity may also be distributed and stored based on the data arrangement ratio in addition to the data arranged on the storage system 2 .
[0160] Moreover, the stripe size 2106 of the data distribution management information 2100 may store a plurality of stripe sizes for respective host logical storage devices as illustrated in FIG. 8 in the above-mentioned configuration, and the data management module 210 may access the different stripe sizes for the respective storage devices 280 , thereby managing the substantial data arrangement ratio.
[0161] Though the detailed description has been given of this invention referring to the drawings, this invention is not limited to this specific configuration, and includes various variations and equivalent configurations within the gist of the accompanying claims.
[0162] As described above, this invention can be applied to a computer system using a storage system provided with a plurality of logical storage devices and a distributed arrangement method for data.
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According to this invention, a data arrangement method, the computer connected to a storage system which provides a plurality of logical storage devices comprising a plurality of physical storage devices arranges data in a logical storage volume constructed by integrating the plurality of logical storage devices. The method includes: a step wherein the computer receives an instruction to build the logical storage volume using the plurality of logical storage devices or to rebuild the constructed logical storage volume; a step wherein the computer obtains information about the plurality of physical storage devices constituting each of the plurality of logical storage devices included in the received instruction; and a step wherein the arrangement position of data into the logical storage volume is determined on the basis of the obtained information about the plurality of physical storage devices.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 60/676,908, filed on May 2, 2005. The disclosure of the above application is incorporated herein by reference.
TECHNICAL FIELD
[0002] The present disclosure relates in general to vehicle door displacement and anti-chucking devices and more specifically to a resilient wedge device and method for assembling a vehicle door resilient wedge device.
BACKGROUND
[0003] Vehicles including automobile sport utility vehicles, station wagons, mini-vans, cross-over vehicles, cargo vans and trucks often provide an access door, commonly known as a lift-gate door. Other similar door designs include hatchback doors, sliding doors and horizontally swinging doors. Although these door designs can be mounted differently, for simplicity, these door designs will hereinafter be summarized in reference to lift-gate doors. Lift-gate doors are frequently hinged along an upper horizontal surface, and latch adjacent to a flooring system of the automobile, commonly adjacent to the rear fender of the automobile. One or more latches can be used. The side edges of lift-gate doors are generally not hinged or physically connected to the vehicle structure or support posts at the rear of the vehicle. Motion of the vehicle therefore can result in “match-boxing”, or non-parallel deflection of the support posts relative to the squared sides of the lift-gate door. Match-boxing is undesirable for several reasons. First, side-to-side or non-parallel motion of support posts can impart additional vehicle noise, known as “chucking” at the lift-gate latch as the vehicle travels along rough or uneven surfaces. Second, unless a mechanism is positioned between the lift-gate door edge and the support posts of the vehicle, full structural allowance for the stiffness of the lift-gate cannot be used in the design of the support structure area.
[0004] In order to include the stiffness of the lift-gate door in the analysis and design of structural support posts, relatively rigid normally plastic wedge assemblies having movable slides have been used which displace to span the gap between the lift-gate door and the support post. These assemblies reduce match-box deflection of the support posts by transferring some deflection load to the lift-gate door using wedge assemblies generally positioned between each support post and the lift-gate door. The wedge assembly can be fastened to either or both edges of the lift-gate door or to an edge of one or both of the support posts. In a further known design, a slide assembly is positioned against each lift-gate door side edge and a striker plate is separately mounted to each support post such that the slide engages the striker plate to limit match-boxing of the support posts.
[0005] Common designs for wedge assemblies have several problems. First, vehicle raffling noise is produced if the slide is not maintained in continuous contact with the striker plate (or vehicle support post) throughout the travel length of the slide. Tolerances used for common wedge assembly slides permit easy translation, but can result in rattling between the parts during vehicle travel. Second, vehicle manufacturing tolerances can result in positions of non-contact between the slide and the striker plate (or vehicle support post). If the slide is not maintained in contact with the vehicle support post or striker plate, rattling can occur. Third, contaminants such as dirt which contact portions of the wedge assembly can prevent the slide from moving freely, thus resulting in increased chucking or rattling noise.
SUMMARY
[0006] According to one embodiment of a resilient wedge for a vehicle door wedge assembly of the present disclosure, the hard plastic wedge of known wedge systems is replaced with a resilient wedge system including a body having an engagement surface with a first extending portion directed inwardly with respect to the body from the engagement surface. A second surface is opposed to the engagement surface, the second surface is oriented at an angle with respect to the engagement surface. The second surface includes a second extending portion directed inwardly from the second surface and toward the first extending portion. Opposed ends integrally join the engagement surface to the second surface. The first and second extending portions define opposed internal cavities of the body. The internal cavities are interconnected by a passageway positioned between the first and second extending portions. The passageway is narrower than the internal cavities and permits elastic deflection of the first extending portion toward the second extending portion.
[0007] According to another aspect of the disclosure, a vehicle door resilient wedge system includes a receiving element having a mating face and a receiving ramp positioned opposite to the mating face. The receiving ramp continuously slopes further away from the mating face between a ramp first end and a ramp second end. An elastically deflectable wedge body engageable with the receiving element in an installed condition includes an engagement surface slidingly received by the receiving ramp. A second surface is opposed to the engagement surface. The second surface is oriented at an angle with respect to the engagement surface. Opposed ends integrally join the engagement surface to the second surface.
[0008] According to yet another aspect of the disclosure, a method for assembling a vehicle door wedge assembly is provided. According to yet still another aspect, a method for creating an elastically deformable wedge for a vehicle door-to-body engagement system is provided.
[0009] A resilient wedge of the present disclosure offers several advantages. By replacing the rigid plastic wedge of common anti-chucking wedge assemblies with a slide-in resilient wedge capable of elastic deformation of the present disclosure, a noise transmission path through the wedge assembly is at least partially attenuated. The resilient wedge also limits match-boxing by its capability to elastically deflect while maintaining continuous contact with either the vehicle door or structural post of the vehicle. The resilient wedge of the present disclosure is a one-piece element which therefore does not require a separate biasing device such as a spring to permit its deflection, which reduces complexity and costs of the design. A one piece resilient wedge of a thermo-plastic or polymeric material also is resistant to the detrimental affects from exposure to moisture and/or dirt.
[0010] Further areas of applicability of the present disclosure will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating several embodiments of the disclosure, are intended for purposes of illustration only and are not intended to limit the scope of the disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein:
[0012] FIG. 1 is a rear elevational view of a vehicle having resilient wedge assemblies of the present disclosure;
[0013] FIG. 2 is a front perspective view of a resilient wedge of the present disclosure installed in an exemplary wedge assembly;
[0014] FIG. 3 is a side elevational view of the resilient wedge of FIG. 2 ;
[0015] FIG. 4 is an end elevational view of the resilient wedge of FIG. 2 ;
[0016] FIG. 5 is a top plan view of the resilient wedge of FIG. 2 ;
[0017] FIG. 6 is a front perspective view of an exemplary wedge assembly body;
[0018] FIG. 7 is an elevational perspective view showing a typical installation of a resilient wedge assembly of the present disclosure into a door frame of a vehicle;
[0019] FIG. 8 is a side elevational view of another embodiment of the resilient wedge of FIG. 2 ;
[0020] FIG. 9 is a plan view of the resilient wedge of FIG. 8 taken at view 9 - 9 of FIG. 8 ;
[0021] FIG. 10 is a cross sectional end elevational view taken at section 10 - 10 of FIG. 8 ; and
[0022] FIG. 11 is a side elevational view of yet another embodiment of the resilient wedge of FIG. 2 .
DETAILED DESCRIPTION
[0023] The following description of several embodiments is merely exemplary in nature and is in no way intended to limit the disclosure, its application, or uses.
[0024] Referring generally to FIG. 1 , a vehicle 10 includes a rear lift-gate door 11 positioned between both a left support post 12 and a right support post 13 of vehicle 10 . A latch 14 is generally provided about mid span along a bottom edge of rear lift-gate door 11 . Side edges of rear lift-gate door 11 adjacent to left support post 12 and right support post 13 , respectively, are generally not latched or otherwise connectable to left support post 12 or right support post 13 .
[0025] According to one aspect of a resilient wedge for an anti-chucking wedge assembly of the present disclosure, and referring generally to FIG. 2 , a resilient wedge 15 of an elastomeric material such as, but not limited to a thermo-plastic elastomer, rubber, neoprene, silicon rubber, a block copolymer material, or other elastically deformable polymeric material(s) is connected to a wedge support member 17 . Resilient wedge 15 is slidably received in the direction of installation arrow “A” between first and second channel walls 18 and 19 to engage resilient wedge 15 with support member 17 in the engaged position shown. A first end 20 of resilient wedge 15 abuts a contact wall 22 of support member 17 in the engaged position. An engagement member 24 extending outwardly from a second end 25 of resilient wedge 15 is partially received by opposing first and second flanges 26 , 27 of support member 17 . To retain resilient wedge 15 in the engaged position, engagement member 24 contacts one of a plurality of raised ribs 28 . Raised ribs 28 are created on a ramp 30 of support member 17 and are positioned substantially parallel to and substantially equidistantly spaced with respect to each other. Ramp 30 slopes upwardly (as viewed in FIG. 2 ) from an end face 29 of support member 17 continuously toward contact wall 22 .
[0026] Referring now generally to FIGS. 3 through 5 , resilient wedge 15 includes a body 31 having an engagement surface 32 and an oppositely positioned second or exposed surface 34 . Second surface 34 is oriented at an angle α with respect to engagement surface 32 . According to one aspect of the present disclosure, angle α is approximately 19.6°. Wedge first end 20 includes a first wall 36 , and second end 25 includes a second wall 37 . In several aspects of the present disclosure, each of first wall and second wall 36 , 37 have a wall thickness “B” of approximately 3.0 mm.
[0027] A first extending portion 38 extends inwardly from second surface 34 . A second extending portion 40 extends inwardly from engagement surface 32 and generally toward first extending portion 38 . A passageway 42 is defined between distal ends of each of first and second extending portions 38 , 40 . In one aspect of the disclosure, passageway 42 has a passageway opening depth “C” of approximately 1.5 mm. First and second extending portions 38 , 40 together define each of a first internal cavity 44 and a second internal cavity 46 having passageway 42 in open communication between them. First and second walls 36 , 37 are preferably created having a convex shape curving outwardly with respect to first and second internal cavities 44 , 46 . The convex shape of first and second walls 36 , 37 permit elastic displacement of first extending portion 38 towards second extending portion 40 until a first contact face 47 of first extending portion 38 contacts a second contact face 48 of second extending portion 40 . Following elastic deformation, second surface 34 returns elastically to the general position shown in FIG. 3 .
[0028] Second contact face 48 is oriented at an angle β with respect to engagement surface 32 . First contact face 47 is oriented substantially parallel to second contact face 48 . This geometry of first and second contact faces 47 , 48 also permits first extending portion 38 to displace in the direction of displacement arrows “H” either before or after contact between first and second contact faces 47 , 48 .
[0029] First and second flanges 50 , 51 extend outwardly from a first and a second side 61 , 62 of body 31 . The purpose of first and second flanges 50 , 51 is to provide additional engagement of resilient wedge 15 with each of first and second flanges 26 , 27 of wedge support member 17 . First flange 50 further includes a first tapering portion 52 and second flange 51 correspondingly includes a second tapering portion 53 . Each of first and second tapering portions 52 , 53 have a distal end face 54 proximate to a distal surface 56 . First and second tapering portions 52 , 53 also help support engagement member 24 . Engagement member 24 further includes an engagement member face 58 and an outer corner 60 which substantially aligns with end face 29 when resilient wedge 15 is fully installed on wedge support member 17 .
[0030] In one aspect of the present disclosure, end face 54 has a face height “E” of approximately 2.0 mm. Engagement member 24 extends beyond end face 54 by an extension length “F” of approximately 4.3 mm. An engagement member face height “G” is approximately 3.5 mm. A total engagement member width “J” is approximately 21.4 mm and a body width “K” is approximately 15.1 mm. Each of first and second tapering portions 52 , 53 have an individual flange element width “L” of approximately 3.2 mm. According to this aspect of the present disclosure, contact face angle β is approximately 7°.
[0031] First and second flanges 50 , 51 extend outwardly as noted from each of first and second sides 61 , 62 and extend longitudinally approximately two-thirds of a total length of body 31 . The length of extension of first and second flanges 50 , 51 can be varied by the designer without departing from the scope of the present disclosure. The shape of each of first and second internal cavities 44 , 46 and passageway 42 can also vary from that shown herein without departing from the scope of the present disclosure.
[0032] As best seen in reference to FIG. 6 , wedge support member 17 according to one aspect of the disclosure includes a support member end face 64 . Ramp 30 is divided into each of a first ramp extension 66 and a second ramp extension 68 . The plurality of raised ribs 28 continue along each of first and second ramp extensions 66 , 68 . Wedge support member 17 further includes a first wing member 70 and a second wing member 72 . A first clearance aperture 74 is positioned in first wing member 70 and a second clearance aperture 76 is positioned in second wing member 72 . A contact face 78 is provided to engage wedge support member 17 with a surface of vehicle 10 .
[0033] Wedge support member 17 further includes a first clearance gap 80 proximate to and running substantially parallel with first flange 26 . Similarly, a second clearance gap 82 is positioned proximate to and running substantially parallel to second flange 27 . First and second flanges 50 , 51 and engagement member 24 are slidably received within each of first and second clearance gaps 80 , 82 when resilient wedge 15 is slidably engaged in installation direction “A”. First and second ramp extensions 66 , 68 are each substantially equally spaced from a ramp longitudinal axis 84 . Each of first and second ramp extensions 66 , 68 end at a ramp second end 85 defining contact wall 22 . In the aspect shown in FIG. 6 , first wing member 70 is substantially smaller than second wing member 72 . First and second wing members 70 , 72 can also be substantially equally sized or first wing member 70 can be larger than second wing member 72 . By changing the geometry of first or second wing members 70 , 72 a right hand or left hand configuration of wedge support member 17 can be provided. The disclosure is therefore not limited to the geometry of wedge support member 17 shown but can be used for a plurality of geometries of wedge support member 17 .
[0034] Resilient wedge 15 is intended to replace the sliding hard plastic wedges of previous anti-chucking wedge assemblies. For example, resilient wedge 15 of the present disclosure can be used to replace slide element 14 and spring element 18 in the assembly identified in U.S. Pat. No. 4,932,100 issued to Flowers et al. on Jun. 12, 1990, which is commonly owned by the assignee of the present disclosure.
[0035] For simplicity, discussion of the present disclosure refers in general to resilient wedge assemblies 16 connected to right support post 13 . Wedge assemblies 16 of the present disclosure are not limited to specific installation locations, and can be connected to left support post 12 or other component parts including the sides, top, or bottom of rear lift-gate door 11 of vehicle 10 or to similar door or door support structure of vehicle 10 . A striker (not shown) can be mounted opposite to resilient wedge 15 on the directly opposing vehicle component to contact resilient wedge 15 , or resilient wedge 15 can directly contact the surface of the directly opposing vehicle component. Wedge assemblies 16 of the present disclosure can be “non-handed” for general interchangeable use or can be configured in “left hand” and/or “right hand” configurations at the discretion of the designer.
[0036] Referring now to FIG. 7 , an exemplary installation of resilient wedge assembly 16 abuts wedge support member 17 against a receiving area 86 of right support post 13 with resilient wedge 15 oriented away from right support post 13 . Receiving area 86 is shown as a stamped or recessed area prelocated on right support post 13 , but can be any suitable surface. Receiving area 86 includes each of a first and a second fastener engagement aperture 88 , 90 . A pair of fasteners 92 and 94 of metal or other known material, including screws, self-tapping screws, self-tapping bolts, or the like are inserted through each of first clearance aperture 74 and second clearance aperture 76 , respectively, to threadably engage with first and second fastener engagement apertures 88 , 90 . Pre-installed or pre-molded nuts (not shown) can also be used in place of the engagement apertures.
[0037] Referring now to FIGS. 8 through 10 , a resilient wedge 100 is modified from resilient wedge 15 to reduce part shrinkage during molding and to provide for moisture drainage to prevent freezing during cold weather application. First extending portion 38 can be modified to include first and second opposed partial cavity pairs 102 , 102 ′ and 104 , 104 ′. First and second opposed partial cavity pairs 102 , 102 ′ and 104 , 104 ′ are separated by a common wall 106 and act to remove material from first extending portion 38 to reduce part shrinkage during production of resilient wedge 100 . Because first and second opposed partial cavity pairs 102 , 102 ′ and 104 , 104 ′ are used, a first through aperture 108 joining first opposed partial cavity pairs 102 , 102 ′ is provided and a second through aperture 110 joins second opposed partial cavity pairs 104 , 104 ′. First and second through apertures 108 , 110 help drain fluid which may be present in any of first and second opposed partial cavity pairs 102 , 102 ′ and 104 , 104 ′ to prevent the fluid from freezing during cold weather conditions of operation.
[0038] Second extending portion 40 is similarly provided with third and fourth opposed partial cavity pairs 112 , 112 ′ and 114 , 114 ′ and third and fourth through apertures 118 , 120 respectively, which serve the same functions as noted above. A second common wall 116 separates third and fourth opposed partial cavity pairs 112 , 112 ′ and 114 , 114 ′. First and second opposed partial cavity pairs 102 , 102 ′ and 104 , 104 ′, and third and fourth opposed partial cavity pairs 112 , 112 ′ and 114 , 114 ′ are substantially oppositely positioned with respect to a resilient wedge longitudinal axis 122 , and a resilient wedge vertical axis 124 .
[0039] A depth and size of each of first and second opposed partial cavity pairs 102 , 102 ′ and 104 , 104 ′, as well as third and fourth opposed partial cavity pairs 112 , 112 ′, and 114 , 114 ′ can also be controlled. This depth and size control helps predetermine the amount of deflection or compression that each of first and second extending portions 38 , 40 can accept when first contact face 47 contacts second contact face 48 . The geometry of first and second extending portions 38 , 40 can also be modified to predetermine the amount of deflection or compression that each of first and second extending portions 38 , 40 can accept.
[0040] Referring now to FIG. 11 , in several embodiments a resilient wedge 126 is modified from resilient wedge 100 . Resilient wedge 126 includes an engagement member 128 having a tapering portion 130 extending therefrom. Tapering portion 130 includes an end face 132 . A curved outer wall 134 encloses first and second internal through cavities 135 , 136 . An inner first wall 138 and an inner second wall 140 define first and second contact faces 142 , 144 between which a passageway 146 opens between the first and second through cavities 135 , 136 . A junction area 148 is created between outer wall 134 , first wall 138 and a column portion 150 . Column portion 150 is oriented at an angle to a base wall 152 and includes a column thickness “M”. A neck region 154 is created between column portion 150 and junction area 148 by a curved surface 156 . A neck region wall thickness “N” is smaller than column thickness “M”, therefore permitting neck region 154 to deflect relative to column 150 . A neck region 157 similar to neck region 154 can also be created between column portion 150 and an extending portion 158 . The extending portion 158 is an extension of base wall 152 and extends away from column 150 by a dimension “P”. Similar to resilient wedge 100 , resilient wedge 126 can include a first partial cavity 160 having a through aperture 162 and a second partial cavity 164 with a through aperture 166 .
[0041] A resilient wedge of the present disclosure offers several advantages. By replacing the rigid plastic wedge of common anti-chucking wedge assemblies with a slide-in resilient wedge of the present disclosure capable of elastic deformation, a noise transmission path through the wedge assembly is at least partially attenuated. The resilient wedge also limits match-boxing by its capability to elastically deflect while maintaining continuous contact with either the vehicle door or structural post of the vehicle. The resilient wedge of the present disclosure is a one-piece element which therefore does not require a separate biasing device such as a spring to permit its deflection, which reduces complexity and costs of the assembly. A one piece resilient wedge of a thermo-plastic or polymeric material also is resistant to the detrimental affects from exposure to moisture and/or dirt.
[0042] The description of the disclosure is merely exemplary in nature and, thus, variations that do not depart from the gist of the disclosure are intended to be within the scope of the disclosure. Such variations are not to be regarded as a departure from the spirit and scope of the disclosure.
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A vehicle door resilient wedge system includes a resilient wedge body coupled to a receiving element. The body includes engagement and second surfaces, and opposed convex ends integrally joining the surfaces. Inwardly extending portions of both surfaces create internal body cavities. A passageway interconnects the cavities which permits wedge elastic deflection.
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BACKGROUND OF INVENTION
1. Field of the Invention
The present invention relates to the vertical blanking interval (VBI) of TV signals, and more particularly, to an apparatus and method for detecting the vertical blanking interval.
2. Description of the Prior Art
The vertical blanking interval (VBI) is a blank interval reserved in a TV signal for the attachment of all kinds of user information. FIG. 1 shows the positions of scan lines for the VBI in different TV specifications. In the National Television System Committee (NTSC) system, each video frame has 525 scan lines; in the Phase Alternating Line (PAL) system, each video frame has 625 scan lines. FIG. 1 illustrates the scan line numbers for Closed Caption (CC), Copy Generation Management System (CGMS), Wildscreen Signaling (WSS), Video Programming System (VPS), and Teletext (TTX) 625B.
FIG. 2 is a schematic diagram of a typical VBI signal. As shown, the VBI signal contained in a scan line comprises the following portions: Hsync signal, color burst signal, clock run-in signal, frame code and data. Different VBI types correspond to different clock run-in signals and frame codes. A conventional VBI decoder is configured according to scan lines positions for a VBI signal within the TV signal. For example, VBI decoding is set to start when the scan line at a certain position is received. The VBI decoding first digitizes the received signals in reference to a preset constant level, for example, the DC voltage level, where the received signal is taken as 1 if its level is above the preset level, and 0 if its level is below the preset level. Next, the digitized signals are subject to slicing and parsing to complete the decoding.
However, the prior art is unable to identify whether the received signal is a VBI signal and hence unable to filter non-VBI noises. In addition, different reference levels needs to be set for different TV specifications, and also the level value should vary under different operating conditions. Hence using a constant reference level for signal digitizing lacks flexibility and accuracy.
SUMMARY OF INVENTION
It is therefore an object of the present invention to provide a VBI detection apparatus and method which can identify and automatically filter non-VBI noises.
Another object of the present invention is to provide a VBI detection apparatus and method, which can compute a corresponding level value for digitizing different types of TV signals.
A further object of the present invention is to provide a VBI decoder which includes the above VBI detection apparatus to enhance its performance.
According to an embodiment of the present invention, an apparatus for detecting a vertical blanking interval is provided. The apparatus comprises: a first detecting unit which generates a detecting signal according to a TV signal; and a computing unit coupled to the first detecting unit to compute a slope of the detecting signal and determine whether the TV signal contains a clock run-in signal according to the computed slope.
According to another embodiment of the present invention, a method for detecting a vertical blanking interval is provided. The method comprises the steps of: generating a detecting signal according to a TV signal; computing a slope of the detecting signal; and determining whether the TV signal contains a clock run-in signal according to the slope.
BRIEF DESCRIPTION OF THE DRAWINGS
The details of the present invention will be more readily understood from a detailed description of the preferred embodiments taken in conjunction with the following figures.
FIG. 1 shows the scan line positions for different VBI types.
FIG. 2 is a schematic diagram of a typical VBI signal.
FIG. 3 is a block diagram of a VBI detection apparatus according to a preferred embodiment of the invention.
FIG. 4 is a diagram showing the correspondence between the clock run-in signal and the detecting signal in the embodiment of FIG. 3 .
FIG. 5A is a block diagram of an embodiment of the first detecting unit in FIG. 3 .
FIG. 5B and FIG. 5C are circuit diagrams respectively showing an embodiment of the IIR filter and the FIR filter in FIG. 5A .
FIG. 6 is a schematic diagram of another embodiment of the first detecting unit in FIG. 3 .
FIG. 7 is a flow chart of a VBI detection method according to a preferred embodiment of the invention.
DETAILED DESCRIPTION
FIG. 3 shows a block diagram of a VBI detection apparatus 30 according to an embodiment of the invention. The VBI detection apparatus 30 can detect different types of VBI signals in TV signals, such as CC, CGMS, WSS, VPS, TTX625B, etc. As shown, the VBI detection apparatus 30 comprises a first detecting unit 31 , a computing unit 32 , a digitizing circuit 33 , and a second detecting unit 34 . The first detecting unit 31 receives a TV signal and generates a detecting signal according to the TV signal. The TV signal is a CVBS signal, Y/C signal, VGA signal, or Y/Pb/Pr signal. The computing unit 32 coupled to the first detecting unit 31 is for computing a slope of the detecting signal, and then comparing the slope with a first threshold to determine whether the TV signal contains a clock run-in signal of the VBI signal.
FIG. 4 is a diagram showing the correspondence between the clock run-in signal and the detecting signal in FIG. 3 . When the first detecting unit 31 receives the clock run-in signal, it generates the corresponding detecting signal as shown in FIG. 4 . The waveform of the detecting signal increases incrementally towards a stable value. The computing unit 32 picks the values of the detecting signal via a window and compute its slope. The width of the window can be adjusted according to actual situations. When the difference of the right side value s_y and the left side value s_x of window-A is greater than the first threshold, it means the clock run-in signal is detected; when the difference is not greater than the first threshold, it means the TV signal does not contain a clock run-in signal, i.e. the TV signal is not a VBI signal but a filterable noise.
After the clock run-in signal is detected, the computing unit 32 will compare the slope of the detecting signal with a second threshold to determine whether the first detecting unit 31 has locked a level value (or called DC level). The second threshold and the first threshold described above can be adjusted according to actual situations. When the difference of the right side value e_y and the left side value e_x of window-B is smaller than the second threshold, it means the first detecting unit 31 has locked the level value, which is the stable value approached by the detecting signal in FIG. 4 . After the first detecting unit 31 has locked the level value, the computing unit 32 emits a control signal to the digitizing circuit 33 . In one embodiment, the first detecting unit 31 includes an infinite impulse response (IIR) filter 311 and a finite impulse response (FIR) filter 312 serially connected as shown in FIG. 5A . FIG. 5B and FIG. 5C are circuit diagrams showing an embodiment of the IIR filter 311 and the FIR filter 312 . As shown, the IIR filter 311 and FIR filter 312 are composed of arithmetic circuits and delay elements to generate the detecting signal. In another embodiment, the IIR filter 311 is serially connected behind the FIR filter 312 . In still another embodiment, as shown in FIG. 6 , the first detecting unit 31 includes an integrator 313 , where the detecting signal is generated by adjusting the resistance R and capacitance C of the integrator 313 .
After the high-frequency noise in the TV signal is filtered by a noise filter 35 , the TV signal is transmitted to the digitizing circuit 33 . After receiving the control signal emitted by the computing unit 32 , the digitizing circuit 33 converts the TV signal into a digital signal in reference to the level value provided by the first detecting unit 31 , where the TV signal is taken as 1 if the signal level is above the level value, and taken as 0 if the signal level is below the level value. The second detecting unit 34 is coupled to the digitizing circuit 33 to detect whether the digital signal contains a frame code. The second detecting unit 34 decodes the frame code, and compare it with the frame codes of various VBI types to determine whether the TV signal contains a VBI signal and to identify the type of the VBI signal. If the TV signal contains the VBI signal, the VBI signal is transmitted to a data slicer for subsequent processing.
The VBI detection apparatus 30 in FIG. 3 can be applied to a VBI decoder to identify and filter non-VBI noises, and according to the type of a detected VBI signal, lock a corresponding level value as a reference for digitizing the TV signal, thereby enhancing the operational flexibility and accuracy of the VBI decoder.
FIG. 7 is a flow chart of a VBI detection method according to a preferred embodiment of the invention. The flow comprises the following steps:
Step 70 : generate a detecting signal according to a TV signal;
Step 71 : compute a slope of the detecting signal;
Step 72 : determine whether the slope in a first interval is greater than a first threshold; if yes, execute step 73 , otherwise return to step 70 ;
Step 73 : determine whether the slope in a second interval is less than a second threshold; if yes, execute step 74 , otherwise return to step 70 ;
Step 74 : generate a level value according to the detecting signal;
Step 75 : filter the noise of the TV signal;
Step 76 : convert the TV signal into a digital signal in reference to the level value;
Step 77 : detect whether the digital signal contains a frame code; if yes, execute step 78 , otherwise return to step 70 ; and
Step 78 : determine whether the TV signal contains a VBI signal and the type of the VBI signal according to the detected frame code.
In step 72 , it can be determined whether the TV signal contains a clock run-in signal. In step 74 , the level value produced is the stable value approached by the detecting signal. In steps 72 , 73 and 77 if the outcome is negative, it means the TV signal does not contain a VBI signal, and the flow would return to step 70 to begin the detection for a next incoming TV signal.
While the present invention has been shown and described with reference to the preferred embodiments thereof and in terms of the illustrative drawings, it should not be considered as limited thereby. Various possible modifications and alterations could be conceived of by one skilled in the art to the form and the content of any particular embodiment, without departing from the scope and the spirit of the present invention.
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An apparatus and method for detecting vertical blanking intervals (VBI) is disclosed. The apparatus can identify and filter non-VBI signals, and calculate a level value for digitization corresponding to the type of television signals. The apparatus includes a detecting unit and a coupled computing unit. The detecting unit is for generating a detecting signal according to a television signal. The computing unit is for calculating a slope of the detecting signal, and for determining whether the television signal contains a clock run-in signal according to the slope.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention concerns a fan control for air conditioning units. More particularly, the herein described invention pertains to an economical control for a multi-speed fan for use in an air conditioning unit including an economizer.
2. Prior Art
Since the rise in the cost of energy, commercial structures, office buildings and retail stores, and other large air handling equipment users have investigated methods of saving energy relative to fan energy consumed in circulating air. Air handling requirements of an air conditioning system are designed to meet the highest requirements of the load or structure. Since the greatest power demand for cooling often occurs during the summer the air handling system must be designed for maximum summer conditions. Thus, during most of the year, the flow of conditioned air through the air handling units may be much greater than necessary. This increased capacity requires a greater initial equipment investment and potentially increased maintenance costs over the operating lift of the system. The operation of the air handling unit at higher capacity then necessary consumes considerable energy in powering fans and may add to the overall cooling load if the fan motor is located in the area cooled.
One method of decreasing air handling energy consumption at less than peak demand is to install load shedding equipment to cycle various air handling devices. Load shedding systems, however, involve motor and belt wear due to frequent cycling and uneven air distribution based on which air handlers are energized. In order to avoid the problems of load shedding, multiple speed fans have been used as an energy reduction device. By operating a system with multiple speed fans it is possible to match the volume of air being circulated with the air conditioning load.
It has been found advantageous to utilize air conditioning systems with economizers. The economizer as used herein is incorporated into an air conditioning unit to allow outdoor ambient air to be drawn into the unit for circulation to the enclosure. It is desirable to circulate outdoor air to the enclosure when its temperature and humidity are such that cooling of the enclosure may be accomplished without operating the refrigeration circuit of the air conditioning unit. The utilization of an economizer requires that sufficient air be circulated such that the air being drawn into the unit through the economizer is circulated to the enclosure and a sufficient volume of air is circulated back to the air conditioning unit. Under some conditions a power exhaust fan, return air fan or a discharge opening may be utilized such that the return air from the enclosure is discharged to the ambient. Hence, any cooling created in this mode of operation is the substitution of cool outdoor ambient air for the existing indoor air.
The present described invention concerns a rooftop type air conditioning unit having an economizer for drawing ambient air into the enclosure when appropriate. The herein invention also includes a multiple speed fan. To optimize energy consumption the fan is operated at high speed whenever ambient air is of sufficiently low temperature to provide cooling to the enclosure even though it is necessary to simultaneously operate refrigeration circuits to effect additional cooling. The fan is operated at low speed saving fan energy when the outdoor ambient temperature is high and the return air from the enclosure to the unit is being reconditioned by operation of the refrigeration circuits and recirculated to the enclosure.
When the temperature differential between the desired temperature and the temperature of the enclosure reaches a predetermined level an override is provided to operate the fan at high speed regardless of the economizer position or temperature of the outdoor air.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a control for an air conditioning unit.
It is a further object of the present invention to provide a method of operating an air conditioning unit having both an economizer and a multiple speed fan.
It is a further object of the present invention to provide a control method capable of saving energy in an air conditioning unit by operating an indoor fan at an appropriate fan speed depending upon the mode of operation of the air conditioning unit as well as the availability of cooler ambient air and the load on the unit.
It is another object of the present invention to provide a safe, efficient and reliable control for operating an air conditioning unit.
Further objects will be apparent from the description to follow and the appended claims.
The above objects are achieved according to a preferred embodiment of the invention by controlling the operation of an air conditioning unit including an adjustable volume air handling means such as a two speed fan for supplying air to an enclosure to be conditioned. Additionally, an economizer having adjustable dampers is provided with the air conditioning unit for regulating the flow of outdoor ambient air to the enclosure. The temperature of the enclosure to be conditioned is sensed and a signal is generated indicative of the difference between the desired temperature of the enclosure and the actual temperature sensed. Additionally, ambient air conditions are sensed and the dampers of the economizer are positioned to allow ambient air to enter the unit when the conditions warrant such that outdoor air may be circulated to the enclosure to effect cooling thereof. The air handling means is energized at a reduced volume flow rate when the conditions do not warrant economizer operation. The air handling means is energized at an increased volume flow rate when the conditions do warrant economizer operation and outdoor ambient air is circulated to the enclosure. Additionally, an override may be included in the method of operation such that whenever the desired temperature exceeds a certain level from the actual temperature sensed the air handling means may be operated at the increased volume flow rate.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of a rooftop type air conditioning unit.
FIG. 2 is a partial wiring schematic of a control for use with an air conditioning unit.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The air conditioning unit described herein will be a two compressor rooftop type unit. It is to be understood that the apparatus and method as described herein are applicable to other types of air conditioning units and are not limited in structure or method to the specific embodiments set forth.
As detailed herein a microprocessor control will be utilized to effect switching between fan speeds and various compressor operations. It is to be understood although a microprocessor control is described herein, numerous other types of devices could achieve the same result. A series of electrical contacts preset to close at different temperature conditions, a mechanical device having separate sensing elements or other apparatus could achieve the same switching operation as set forth in the description and as presently available in the microprocessor control.
Referring now to FIG. 1, there can be seen an air conditioning unit 10 which is designed to be mounted to the rooftop of an enclosure to be conditioned. This air conditioning unit is divided by partition 46 into an indoor section 4 and outdoor section 6. Compressors referenced by numerals 14 and 16 are located in the outdoor section of the unit. Additionally, condenser 18 and condenser fan 29 powered by condenser fan motor 28 are located in the outdoor section of the unit.
The indoor section 4 of the unit includes an evaporator 20, supply fan motor 26, supply fan scroll 24, supply fan 22 and electric heaters 30. Coil supports 36 and 38 are shown for supporting evaporator 20. The supply fan is a centrifugal or squirrel cage type fan mounted for rotational movement on a bearing system and is driven by a pulley system through supply fan motor 26. The indoor air flow, as shown in FIG. 1, is upwardly through return air opening 40 through evaporator 20 into the fan scroll. Air is discharged from fan 22 downwardly through electric heaters 30 and through the supply air opening back to the enclosure.
Economizer 50 is shown mounted to a portion of indoor air section 4. Dampers 52 are mounted for rotational movement and are driven by economizer motor 54 such that they may be positioned to either allow or prevent ambient air flow into the indoor section of the unit. Outdoor condition sensor 48 and thermostat 46 are both shown.
Referring to FIG. 2, there may be seen a partial wiring schematic for an air conditioning unit. As shown therein, power is supplied between lines L-1 and L-2 through wires 101 and 102. Wire 101 is connected to fan relay FR1-1 normally open contacts and to fan relay FR2-1 normally open contacts. Wire 106 connects fan relay FR1-1 contacts with fan relay FR2-1 contacts, fan relay FR3-1 normally closed contacts and fan relay FR3-2 normally open contacts. Wire 107 connects normally closed fan relay FR3-1 contacts with time delay relay TDR-1 and the time delay relay TDR-1 contacts. Wire 108 connects the time delay relay TDR-1 contacts with the low speed fan contactor FC-1.
Wire 109 connects the fan relay FR3-2 contacts with time delay relay TDR-2 and time delay relay normally open contacts TDR-2. Wire 110 connects the normally open time delay relay contacts TDR-2 with high speed fan contactor FC-2. A winding of transformer T-1 is connected between wires 101 and 102. The portion of the circuit just described is the power portion of the circuit and is typically operated at 115 volts. Although various contactors have been shown the remaining elements such as compressor motors, indoor and outdoor fan motors, reversing valve solenoids and other elements that may be typically incorporated in the unit have not been included herein since they have no direct bearing on the invention set forth.
In the control portion of the wiring schematic, power is supplied between the wires 120 and 130 through a winding of transformer T-1. Microprocessor control 80 has a series of six contacts contained therein, these contacts being normally open such that upon the receipt of the appropriate signal they are closed. These six contacts are labeled Heat 1, Heat 2, Cool 1, Cool 2, Cool 3 and Cool 4.
Wire 120 connects transformer T-1 to low ambient lockout 60, heating relay contacts HR-1, to microprocessor control 80 and through the microprocessor control to switches Heat 1, Heat 2 and Cool 4. Low ambient lockout 60 is connected via line 152 to the Cool 2 switch of the microprocessor control. The low ambient lockout is also connected by wire 154 to the Cool 3 switch of microprocessor control 80.
Microprocessor control 80 is supplied with power via connections by line 120 to one side of transformer T-1 and via lines 134 and 130 to the other side of transformer T-1.
Heating relay contacts HR-1 are connected by wire 132 to fan relay FR-1 which is connected to wire 130. The Heat 1 switch of the microprocessor control is connected by wire 136 to heating relay HR-1 and fan relay FR-4. The Heat 2 switch of the microprocessor control is connected by wire 138 to heating relay HR-2. The Cool 1 switch of the microprocessor control is connected by wire 142 to fan relay FR-3. The Cool 1 switch is also connected by wire 140 to the Cool 4 switch of the microprocessor control and to the normally open fan relay contacts FR4-1 and to the normally open freezestat contacts F.
Wire 144 connects the normally open switch Cool 2 of the microprocessor to compressor relay CR-1. The Cool 3 switch of the microprocessor control is connected by wire 146 to the second compressor relay CR-2. Wire 148 connects thermostat 46 to the microprocessor control and wire 150 connects economizer motor 54 to the microprocessor control.
Fan control 47, a portion of thermostat 46, is connected by wire 158 to fan relay FR-2 to enthalpy control 49 and to the normally closed power exhaust relay contacts PER-1. Wire 160 connects the enthalpy control to power exhaust relay PER. Wire 156 connects the normally closed power exhaust relay contacts PER-1 to the Cool 1 switch of the microprocessor control and to normally open fan relay contacts FR3-3. Wire 130 connects one side of transformer T-1 to fan relay FR-1, heating relay HR-1, fan relay FR-4, heating relay HR-2, fan relay FR-3, first compressor relay CR-1, second compressor relay CR-2, fan relay FR-2, power exhaust relay PER and to exhaust motor contactor EMC. Wire 162 connects fan relay contacts FR3-3 to economizer limit switch ELS which is connected by wire 164 to exhaust motor contactor EMC.
Operation
A refrigeration circuit of an air cooled air conditioning unit is normally utilized to transfer heat energy between the indoor air and outdoor air. The supply fan circulates air from the space to be conditioned through the indoor coil or evaporator 20 herein then returns said air to the space to to be conditioned through supply air opening 42. When the outdoor air temperature is sufficiently cool, air is drawn by supply fan 22 through the economizer through dampers 52 into the unit and then circulated to the space to be conditioned. When the economizer is operating air may be discharged from the enclosure by an exhaust fan or other device not shown.
When the air conditioning unit is in the cooling mode of operation the thermostat 46, including fan on control 47, signals the unit to become energized. Typically, a building is programmed to turn the air conditioning on in the morning prior to the building occupancy. At this time power is supplied through wire 158 to fan relay FR-2 which acts to close fan relay contacts FR2-1 completing the circuit to time delay relay TDR-1. After a short time interval contacts TDR-1 close energizing fan contactor FC-1 through wires 101, 106, 107 and 108 thereby operating the fan at low speed. The actual fan contactors and fan motors are not shown. The unit operates with the fan circulating air for ventilation purposes at low speed at all times the unit is energized. Thermostat 46 senses the temperature of the air in the enclosure and compares that temperature to a setpoint. Thermostat 46 is designed to generate an increasing signal as the variance between the setpoint and the desired temperature increases. This increasing signal is allowed to close switches Cool 1, Cool 2, Cool 3 and Cool 4 in successive order as the variance from the setpoint increases.
Enthalpy control 49 senses the temperature and potentially the humidity of the ambient air and determines whether or not the ambient air may be circulated to othe enclosure to effect cooling. The microprocessor control based upon a signal from the thermostat acts to effect switching if a cooling demand is present. Upon the thermostat sensing a first stage cooling demand switch Cool 1 is closed. If the enthalpy control senses ambient air may be used for cooling then the enthalpy control does not energize power exhaust relay PER and normally closed power exhaust relay contacts PER-1 remain closed and power is supplied through wires 158 and 156 to switch Cool 1. When the thermostat senses the appropriate cooling load switch Cool 1 is closed and fan relay FR-3 is energized through wire 142. Normally closed fan relay contacts FR3-1 are opened and normally open fan relay contacts FR3-2 are closed. This allows the time delay relay TDR-2 to be energized through wire 109. Shortly thereafter time delay relay contacts TDR-2 are closed energizing fan contactor FC-2, the high speed contactor, through wire 110. Hence, under this particular condition the indoor fan is operated at high speed. Since normally closed fan relay contacts FR3-1 are now opened the fan cannot be operated at low speed.
Upon the thermostat sensing an additional cooling need switch Cool 2 will be closed energizing through wire 144 compressor relay CR-1. Compressor relay contacts CR-1 then close energizing compressor contactor CC-1 which acts to energize the first compressore thereby operating a refrigeration circuit. If the energization of this first refrigeration circuit still does not serve to meet the cooling load the thermostat, upon a further rise in temperature, will energize switch Cool 3 through which wire 146 energizes compressor relay CR-2 and consequently compressor contactor CC-2. At this point in time both refrigeration circuits are operating. Should the temperature still continue to rise then relay switch Cool 4 will be closed supplying power to the fan relay 3. However, since the unit is already operating with the fan at high speed this will have no effect.
During operation of the unit with the enthalpy control sensing cooling available in the ambient air, normally closed contacts PER-1 supply power to normally open fan relay contacts FR3-3. Since fan relay FR-3 is energized upon a cooling load being sensed fan relay contacts FR3-3 will close energizing an exhaust fan via exhaust motor contactor EMC. An economizer limit switch ECL is provided to close when the economizer is open to prevent operation of the exhaust fan if the economizer is closed.
If the air conditioning unit, when in the cooling mode, senses through enthalpy control 49 that the ambient air is at a high temperature and is not capable of being used to cool the enclosure then enthalpy control 49 energizes power exhaust relay PER. Power exhaust relay contacts PER-1 are opened and the potential source of power to switch Cool 1 and fan relay contacts FR3-3 is removed. Hence, with the economizer in the closed position the advent of a cooling load will result in switch Cool 1 being closed, however, the fan speed does not switch since there is no power supplied to the Cool 1 switch. Upon an increased cooling load being sensed, the Cool 2 switch will close energizing, through wire 144, compressor relay CR-1. Upon a further request for cooling the Cool 3 switch will close energizing compressor relay CR-2 through wire 146. During the operation of one or both compressors the fan speed has remained at low speed since fan relay FR-3 has not been energized. Should the temperature in the space continue to rise the Cool 4 switch will be closed. By closing the Cool 4 switch power is supplied through wire 140 to wire 142 energizing fan relay FR-3 thereby switching the fan speed from low to high.
In the heating mode of operation, heating relay HR-1 and fan relay FR-4 are energized once switch Heat 1 is closed by the thermostat sensing a heating need. Fan relay FR-4 acts to close fan relay contacts FR4-1 which connects power to fan relay FR-3 acting to switch the fan to the high speed mode of operation. Hence, upon a first stage heat demand being sensed the fan operates at high speed. Upon the second stage heat demand being sensed by thermostat 46 switch Heat 2 will close energizing, through wire 138, heating relay HR-2. While not shown, the heating relays will act to energize electric heaters 30 of the air conditioning unit to supply heat energy to the enclosure.
Low ambient lockout 60 prevents the compressors from being energized through compressor relays CR-1 and CR-2 when the outdoor ambient temperature is below a predetermined level.
Freeze contacts F are closed by a temperature sensing device when a potential freezeup problem at the indoor coil develops. The closing of freezeup contacts F energizes the fan at high speed through fan relay FR-3 to prevent ice formation by circulating a larger volume of indoor air per unit time.
The microprocessor control described herein is a commercially available control manufactured by Honeywell, Inc. of Minneapolis, Minn.
The invention has been described herein referenced to a particular embodiment. It is to be understood that modifications and variations can be made within the spirit and scope of this invention. It is also to be understood that although a microprocessor switching device has been described, other methods of accomplishing this same control function would serve equally well.
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An apparatus and method for operating an air conditioning unit incorporating both an economizer and a two speed fan are described. When the economizer is in operation the fan is typically operated at high speed regardless of refrigeration circuit operation to circulate sufficient outdoor air to the enclosure. When the economizer is closed, indicating the outdoor air is too warm to provide cooling to the enclosure, the fan is typically operated at low speed saving fan energy. An override control is provided for operating the fan at high speed regardless of the outdoor temperature should sufficient cooling demand be detected.
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FIELD OF THE INVENTION
The present invention relates to methods and devices for preventing the formation of pinholes in the production of laminates of non-woven webs and polymer film. In particular, these laminates have spaced laminated strips of non-woven webs and film with areas of nonlaminated film therebetween (herein referred to as “zone laminates”).
BACKGROUND OF THE INVENTION
Methods of making microporous film products have been known for some time. For example, U.S. Pat. No. 3,832,267, to Liu, teaches the melt-embossing of a polyolefin film containing a dispersed amorphous polymer phase prior to stretching or orientation to improve gas and moisture vapor transmission of the film. According to the Liu '267 patent, a film of crystalline polypropylene having a dispersed amorphous polypropylene phase is embossed prior to biaxially drawing (stretching) to produce an oriented imperforate film having greater permeability. The dispersed amorphous phase serves to provide microvoids to enhance the permeability of the otherwise imperforate film to improve moisture vapor transmission (MVT). The embossed film is preferably embossed and drawn sequentially.
Many other patents and publications disclose the phenomenon of making microporous thermoplastic film products. For example, European patent 141,592 discloses the use of a polyolefin, particularly ethylene vinyl acetate (EVA) containing a dispersed polystyrene phase which, when stretched, produces a voided film which improves the moisture vapor permeability of the film. The EP '592 patent also discloses the sequential steps of embossing the EVA film with thick and thin areas followed by stretching to first provide a film having voids which, when further stretched, produces a net-like product. U.S. Pat. Nos. 4,596,738 and 4,452,845 also disclose stretched thermoplastic films where the dispersed phase may be a polyethylene filled with calcium carbonate to provide the microvoids upon stretching. Later U.S. Pat. Nos. 4,777,073; 4,921,653; and 4,814,124 disclose the same processes described by the above-mentioned earlier publications involving the steps of first embossing a polyolefin film containing a filler and then stretching that film to provide a microporous product.
U.S. Pat. Nos. 4,705,812 and 4,705,813 disclose microporous films having been produced from a blend of linear low density polyethylene (LLDPE) and low density polyethylene (LDPE) with barium sulfate as the inorganic filler having an average particle diameter of 0.1-7 microns. It is also know to modify blends of LLDPE and LDPE with a thermoplastic rubber such as KRATON. Other patents such as U.S. Pat. No. 4,582,871 disclose the use of thermoplastic styrene block tripolymers in the production of microporous films with other incompatible polymers such as styrene. There are other general teachings in the art such as the disclosures in U.S. Pat. Nos. 4,921,652 and 4,472,328.
The stretching, as discussed above, results in the appearance of stripes along the length of the web. These stripes are caused by the difference in appearance between the highly stretched areas, occurring between the digits on the interdigital rolls, and the areas at the digits which are not as highly stretched. These methods result in stripes of highly stretched, highly porous areas adjacent moderately stretched, but still substantially porous, areas.
Relevant patents regarding extrusion lamination of unstretched non-woven webs include U.S. Pat. Nos. 2,714,571; 3,058,868; 4,522,203; 4,614,679; 4,692,368; 4,753,840 and 5,035,941. The above '863 and '368 patents disclose stretching extruded polymeric films prior to laminating with unstretched non-woven fibrous webs at pressure roller nips. The '203 and '941 patents are directed to co-extruding multiple polymeric films with unstretched non-woven webs at pressure roller nips. The '840 patent discloses preforming non-woven polymeric fiber materials prior to extrusion laminating with films to improve bonding between the non-woven fibers and films. More specifically, the '840 patent discloses conventional embossing techniques to form densified and undensified areas in non-woven base plies prior to extrusion lamination to improve bonding between non-woven fibrous webs and films due to the densified fiber areas. The '941 patent also teaches that unstretched non-woven webs that are extrusion laminated to single-ply polymeric films are susceptible to pinholes caused by fibers extending generally vertically from the plane of the fiber substrate and, accordingly, this patent discloses using multiple co-extruded film plies to prevent pinhole problems. Furthermore, methods for bonding loose non-woven fibers to polymeric film are disclosed in U.S. Pat. Nos. 3,622,422; 4,379,197 and 4,725,473.
U.S. patent application Ser. No. 08/547,059 (herein incorporated by reference in its entirety), now abandoned, discloses a process and apparatus to continuously perform web splitting, separating, guiding and laminating steps in a single unit. A single wide web of a non-woven is slit into a number of narrow webs which are separated by the use of turning bars and steered into a laminator. More specifically, a web is unrolled from a wide roll of non-woven material. The incoming web is slit into narrow webs, the narrow webs move down line to turning bars which are displaced one from the other by a desired web separation distance. The spaced narrow webs are then guided into a nip of rollers for extrusion lamination with a polymer film. A molten polymer is extruded into the nip at a temperature above its softening point to form a polymeric film laminated to the narrow webs. The compressive force between the webs and the extrudate at the nip is controlled to bond one surface of the web to the film to form the laminate. The resulting laminate includes spaced strips of non-woven laminated to the polymer film with areas of nonlaminated film between the strips.
U.S. patent application Ser. No. 08/722,286 (herein incorporated by reference in its entirety), a Continuation-In-Part of U.S. patent application Ser. No. 08/547,059, discloses a process and apparatus to continuously perform lamination of a polymer to another material to which it is laminated. The '286 application is directed to a process and apparatus to continuously perform non-woven web splitting, folding, guiding and laminating steps in a single unit. Depending on the spacing between folded webs, each strip of polymer may include a loose flap on either side of the laminate area which may be suitable for forming a barrier cuff in a diaper or other hygiene product. The spacing between folded webs determines the width of the loose polymer flap which is formed. Again, the resulting laminate includes spaced strips of non-woven laminated to the polymer film with areas of nonlaminated film between the strips. These laminates, having spaced laminated strips of non-woven and film with areas of nonlaminated film therebetween, are referred to as zone laminates. The resulting laminate includes spaced strips of non-woven laminated to the polymer film with areas of nonlaminated film between the strips.
SUMMARY OF THE INVENTION
With the development of the above referenced zone laminates, it has been discovered that pin-holes form at the boundary area between the laminated and non-laminated areas when the zone laminate is made microporous by stretching across the length of the strip. The method and apparatus of the present invention prevents the formation of pin-holes during such stretching of zone laminates. Pinholes are prevented by creating slack areas along the length of the web where the edges of the non-woven strips meet with the polymer film, pressing the slack areas into interdigital stretching rollers without stretching the slack areas, and stretching the remainder of the web by interdigitation. The slack regions are formed prior to interdigitation by, for example, formation of a furrow, a fold or a corrugation.
In one embodiment, the present invention includes a first interdigital roller and a second interdigital roller and at least one disc for contacting a slack area in the laminate and pressing the slack area into the first interdigital roller without stretching the slack area. In a preferred form, the device includes at least one disc which interengages with spaced rollers to create a slack area along the length of a laminate, the interengaged disc and rollers being laterally adjustable to create the slack area in a predetermined position on the width of the web.
These and other advantages and features, which characterize the invention, are set forth in the claims. For a better understanding of the invention, and of the advantages and objectives attained through its use, reference should be made to the Drawings, and to the accompanying descriptive matter, in which exemplary embodiments of the invention are described.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic perspective view showing an apparatus for pinhole prevention in zone laminates in accordance with one embodiment of the present invention.
FIG. 2 is a cross-sectional view showing an apparatus for pinhole prevention suitable for use in accordance with one embodiment of the present invention.
FIG. 3 is a cross-sectional view taken along line 3 — 3 of FIG. 2 of spacer discs and a furrow disc suitable for creating a slack area in a laminate in accordance with the present invention.
FIG. 3A is an enlarged plan view of the spacer discs and furrow discs shown in FIG. 3 .
FIG. 4 is a cross-sectional view taken along line 4 — 4 of FIG. 2 of the presser disc forcing the laminate into the grooves on the first interdigital roller in accordance with one embodiment of the present invention.
FIG. 5 is a cross-sectional view taken along line 5 — 5 of FIG. 2 showing the intersection of the first and second interdigital rollers used for stretching the laminate in the cross machine direction.
FIG. 6 is a plan view of a progressive roll former suitable for use in creating a slack area in the laminate in accordance with one embodiment of the present invention.
FIG. 7 is a cross-sectional view taken along line 7 — 7 of FIG. 6 .
FIG. 8 is a schematic perspective view of a corrugator suitable for creating a slack area in the non-woven laminate suitable for use in the present invention.
FIG. 9 is a cross-sectional view taken along line 9 — 9 of FIG. 8 .
FIG. 10 is a graph showing the relationship between line speed and screw RPM of an extruder for use with the present invention.
FIG. 11 is a graph demonstrating the relationship between moisture vapor transmission properties and incremental stretching.
FIG. 12 is a graph showing the relationship between moisture vapor transmission rate and finish roll temperature prior to CD intermeshing.
FIG. 13 is an enlarged schematic cross-sectional view of the boundary area of the laminate after interdigital stretching.
DETAILED DESCRIPTION
The method and apparatus of the present invention prevent the formation of pin-holes at the boundary area of a zone laminate at the edges of a non-woven strip during interdigital stretching. Pin-holes form at the edge of the non-woven strip because the film and non-woven laminate is substantially stronger than the adjacent unlaminated polymer film; therefore, substantially all of the stretching occurs in the unlaminated film of the boundary area. It has been discovered that this excessive stretching in the boundary areas causes the formation of pin-holes.
In order to prevent pin-holing, the present invention provides for the formation of a slack area 10 a at the boundary areas of the laminate, that is, where the edge of the non-woven strips 14 meet the polymer film 12 in laminate 10 , as shown in FIGS. 1, 3 A and 13 . In order to create these slack areas a number of spacer discs 18 which are slidably mounted on axle 16 are positioned such that the gap between adjacent discs 18 align with the boundary areas. Furrow discs 22 are slidably mounted on axle 20 so that each furrow disc 22 is received in the gap between adjacent spacer discs 18 at the boundary areas. A set of two spacer discs 18 and one furrow disc 22 interengage (as shown in FIGS. 3 and 3 a ) to create a slack area 10 a along the length of the laminate 10 . The laminate 10 , including slack area 10 a , travels to the first interdigital roller 26 where the slack area is forced into the interdigital grooves 28 on roller 26 by presser disc 32 . Presser disc 32 includes a presser area 34 which conforms to the cross section of grooves 28 . The presser discs 32 force slack area 10 a into the grooves 28 on the first interdigital roller 26 and form taut 37 areas along the remaining width of laminate 10 . The taut areas 37 pass between first roller 26 and second roller 38 and are stretched by interdigital grooves 28 and 40 to form microporous laminate 50 .
The microporous laminate may optionally be stretched along the length of microporous laminate 50 to increase porosity. The lengthwise stretching may be performed by any known method of forming micropores such as interdigital rolling or differential speed stretching of the laminate 10 either before or after stretching in the cross-machine direction.
As can be seen in FIG. 2, spacer discs 18 are mounted upon axle 16 by collar 18 a and set screw 18 b . Furrow discs 22 are mounted upon axle 20 by collar 22 a and set screw 22 b . Axle 20 is mounted upon a rotatable axle support 20 a which pivots from a nonengaged position to an engaged position (shown in FIG. 2 ). The capacity to move furrow discs 22 to a nonengaged position allows for simplified threading of laminate 10 between spacer discs 18 and furrow discs 22 . When engaged, a furrow disc 22 is interengaged with a pair of spacer discs 18 to form a furrow which creates slack area 10 a at the boundary areas of laminate 10 . Interdigital roll 26 is rotatably mounted on axle 24 and presser discs 32 are rotatably mounted on axle 30 . Presser discs 32 are movable along the length of axle 30 by collar 32 a and set screw 32 b . Presser discs 32 are movable along axle 30 in a method similar to the movement of furrow discs 22 along axle 20 as discussed above. The presser disc 32 includes a presser area 34 around its periphery which is complimentary to the grooves on roll 26 . Presser area 34 presses the slack area 10 a of laminate 10 into the grooves 28 on roll 26 without stretching of the slack area 10 a . The width of the laminate 10 , other than the slack areas 10 a , are held taut against the grooves of roller 26 so that the taut areas 37 are interdigitally stretched between roller 26 and roller 38 .
The intermeshing rollers 26 , 38 are capable of large engagement depths which may stretch the laminate up to about 200% or more of the original width to form the micropores. The equipment incorporates a controller (not shown) for the shafts 24 , 36 of the two intermeshing rollers 26 , 38 to control the degree of intermeshing and hence the amount of stretching imparted to the laminate. The controller also keeps shafts 24 , 36 parallel when the top shaft is raised or lowered to assure that the teeth of one intermeshing roller always fall between the teeth of the other intermeshing roller to avoid potentially damaging physical contact between intermeshing teeth. This parallel motion is assured by a rack and gear arrangement (not shown) wherein a stationary gear rack is attached to each side frame in juxtaposition to vertically slidable members. A shaft traverses side frames and operates a bearing in each of the vertically slidable members. A gear resides on each end of the shaft and operates in engagement with the racks to produce the desired parallel motion.
As shown in FIG. 3, the force of furrow discs 22 between spacer discs 18 causes the formation of a furrow to form slack area 10 a between spacer discs 18 . As shown in detail in FIG. 3A the slack area 10 a is preferably formed at the boundary areas of the zone laminate where the edges of the non-woven 14 meet polymer film 12 . The laminate 10 , including slack areas 10 a , travels from spacer discs 18 and furrow discs 22 to the first interdigitating roller 26 . As the first interdigitating roller 26 rotates about axle 24 , slack area 10 a is pressed into the grooves 28 of the first interdigitating roller 26 by the complimentary structure 34 of presser rollers 32 , as shown in FIG. 4 . Due to the creation of the slack area 10 a , the laminate 10 is pressed into grooves 28 to form taut areas 37 but without stretching the web. The web then rotates about first interdigitating roller 26 to meet second interdigitating roller 38 . Interdigitating roller 38 rotates about axle 36 and grooves 40 intermesh with grooves 28 to stretch the taut areas 37 of laminate 10 in the cross-machine direction, that is, substantially no stretching occurs where the slack areas 10 a have been pressed into the grooves 28 on the first roller 26 .
As can be seen in FIG. 3 the spacer discs 18 may be variously positioned along axle 16 by use of clamping collars 18 a and clamping screws 18 b . Each furrow disc 22 includes a clamping collar 22 a with a set screw 22 b to allow the furrow disc to be variably positioned along axle 20 . Similarly, presser discs 32 include clamping collar 32 a and set screw 32 b to allow the presser discs 32 to be variably positioned along axle 30 . This adjustability allows for the processing of various widths of laminate without the need for substantial time spent setting up the machinery.
As seen in FIG. 4 and 5, presser disc 32 interengages with grooves 28 on interdigital roll 26 by complimentary presser area 34 such as circumferential grooves to interact with a cross directional interdigital stretcher, a helical gear to interengage with a diagonal intermeshing stretcher, or a deformable member which conforms to the surface of roll 26 . Presser roller 32 forces the slack area 10 a of laminate 10 into the grooves of roller 26 so that the taut areas 37 of laminate 10 are formed on either side of the presser roller 32 . These taut areas 37 are subsequently stretched between interdigital rollers 26 , 38 to form the microporous zone laminated sheet 50 having substantially unstretched portions along the length thereof. FIG. 13 shows the stretched laminate 50 including micropores 12 a in the taut areas 37 of the polymer film 12 and the lack of micropores in the boundary area.
Other methods of forming a slack area 10 a are shown in FIGS. 6-9. As shown in FIGS. 6 and 7 a progressive roll former 100 which includes a series of increasingly overlapped rollers may be used to create slack area 10 a . The first set of rollers 102 a , 104 a , 106 a deform the laminate 10 to form a small slack area. The second set of rollers 102 b , 104 b , 106 b have a larger overlap and thus form a larger slack area. The third set of rollers 102 c , 104 c , 106 c are overlapped to form a slack area 10 a of the desired shape.
A corrugator 120 , as seen in FIGS. 8 and 9 include a first support plate 122 having a female corrugator 124 and a second support plate 126 which includes male corrugator section 128 . The male 128 and female 124 corrugator sections have an increasing cross-sectional area along the length of the web and are nested to cause the laminate 10 to deform and thus create slack area 10 a.
The laminate of the present invention may be achieved with the use of a wide variety of polymer films; however, in a preferred form the film is manufactured by first melt blending a composition of:
(a) about 35% to about 45% by weight of a linear low density polyethylene,
(b) about 3% to about 10% by weight of a low density polyethylene,
(c) about 40% to about 50% by weight calcium carbonate filler particles, and
(d) about 2% to about 6% by weight of a triblock copolymer of styrene selected from the group consisting of styrene-butadiene-styrene, styrene-isoprene-styrene, and styrene-ethylene-butylene-styrene, and blends thereof,
extruding the melt blended composition into a nip of rollers with an air knife to form a film at a speed on the order of at least about 550 fpm to about 1200 fpm without draw resonance, and
applying an incremental stretching force to the film along lines substantially uniformly across the taut areas of the laminate and throughout its depth to provide a microporous film.
More particularly, in a preferred form, the melt-blended composition consists essentially of about 42% by weight LLDPE, about 4% by weight LDPE, about 44% by weight calcium carbonate filler particles having an average particle size of about 1 micron, and about 3% by weight triblock polymer, especially styrene-butadiene-styrene. If desired, the stiffness properties of the microporous film products may be controlled by including high density polyethylene on the order of about 0-5% by weight and including 0-4% by weight titanium dioxide. Typically, a processing aid such as a fluorocarbon polymer in an amount of about 0.1% to about 0.2% by weight is added, as exemplified by 1-propene,1,1,2,3,3,3-hexafluoro copolymer with 1,1-difluoroethylene is included in the melt. The triblock polymer may also be blended with oil, hydrocarbon, antioxidant and stabilizer.
Both embossed and flat films may be produced according to the principles of this invention. In the case of an embossed film, the nip of rollers comprises a metal embossing roller and a rubber roller. The compressive force between the rollers forms an embossed film of desired thickness on the order of about 0.5 to about 10 mils. It has also been found that rollers which provide a polished chrome surface form a flat film. Whether the film is an embossed film or a flat film, upon incremental stretching at high speeds, microporous film products are produced having high moisture vapor transmission rate (MVTR) within the acceptable range of about 1000 to 4000 gms/m 2 /day. It has been found that flat film can be incrementally stretched more uniformly than embossed film. The process may be conducted at ambient or room temperature or at elevated temperatures. As described above, laminates of the microporous film may be obtained with non-woven fibrous webs.
The non-woven fibrous web may comprise fibers of polyethylene, polypropylene, polyesters, rayon, cellulose, nylon, and blends of such fibers. A number of definitions have been proposed for non-woven fibrous webs. The fibers are usually staple fibers or continuous filaments. The non-wovens are usually referred to as spunbond, carded, meltblown and the like. The fibers or filaments may be bicomponent to facilitate bonding. For example, a fiber having a sheath and core of different polymers such as polyethylene (PE) and polypropylene (PP) may be used or mixtures of PE and PP fibers may be used. As used herein “non-woven fibrous web” is used in its generic sense to define a generally planar structure that is relatively flat, flexible and porous, and is composed of staple fibers or continuous filaments. For a detailed description of non-wovens, see “Nonwoven Fabric Primer and Reference Sampler” by E. A. Vaughn, Association of the Non-woven Fabrics Industry, 3d Edition (1992).
In a preferred form, the microporous laminate employs a film having a gauge or a thickness between about 0.25 and 10 mils and, depending upon use, the film thickness will vary and, most preferably, in disposable applications, is on the order of about 0.25 to 2 mils in thickness. The non-woven fibrous webs of the laminated sheet normally have a weight of about 5 gms/yd 2 to 75 gms/yd 2 , preferably about 20 to about 40 gms/yd 2 . The composite or laminate can be incrementally stretched in the cross-direction (CD) to form a CD stretched composite. Furthermore, CD stretching may be followed by stretching in the machine direction (MD) to form a composite which is stretched in both CD and MD directions. As indicated above, the microporous film or laminate may be used in many different applications such as baby diapers, baby training pants, catamenial pads and garments, and the like where moisture vapor and air transmission properties, as well as fluid barrier properties, are needed.
The laminate is then incrementally stretched in the cross-direction (CD) or diagonally using the apparatus of the present invention to form a stretched laminate having unstretched regions along the length of the laminate. Furthermore, stretching according to the present invention may be followed by stretching in the machine direction (MD).
A number of different stretchers and techniques may be employed to stretch the film or laminate of a non-woven fibrous web and microporous-formable film. These laminates of non-woven carded fibrous webs of staple fibers or non-woven spun-bonded fibrous webs may be stretched with the stretchers and techniques described as follows:
The diagonal intermeshing stretcher consists of a pair of left hand and right hand helical gear-like elements on parallel shafts. The shafts are disposed between two machine side plates, the lower shaft being located in fixed bearings and the upper shaft being located in bearings in vertically slidable members. The slidable members are adjustable in the vertical direction by wedge shaped elements operable by adjusting screws. Screwing the wedges out or in will move the vertically slidable member respectively down or up to further engage or disengage the gear-like teeth of the upper intermeshing roll with the lower intermeshing roll. Micrometers mounted to the side frames are operable to indicate the depth of engagement of the teeth of the intermeshing roll.
Air cylinders are employed to hold the slidable members in their lower engaged position firmly against the adjusting wedges to oppose the upward force exerted by the material being stretched. These cylinders may also be retracted to disengage the upper and lower intermeshing rolls from each other for purposes of threading material through the intermeshing equipment or in conjunction with a safety circuit which would open all the machine nip points when activated.
A drive is typically utilized to drive the stationery intermeshing roller. If the upper intermeshing roller is to be disengagable for purposes of machine threading or safety, it is preferable to use an antibacklash gearing arrangement between the upper and lower intermeshing rollers to assure that upon reengagement the teeth of one intermeshing roller always falls between the teeth of the other intermeshing roller and potentially damaging physical contact between addenda of intermeshing teeth is avoided. If the intermeshing rollers are to remain in constant engagement, the upper intermeshing roll typically need not be driven. Drive may be accomplished by the driven intermeshing roller through the material being stretched.
The intermeshing rollers closely resemble fine pitch helical gears. In the preferred embodiment, the rollers have 5.935″ diameter, 45° helix angle, a 0.100″ normal pitch, 30 diametral pitch, 14½° pressure angle, and are basically a long addendum topped gear. This produces a narrow, deep tooth profile which allows up to about 0.090″ of intermeshing engagement and about 0.005″ clearance on the sides of the tooth for material thickness. The teeth are not designed to transmit rotational torque and do not contact metal-to-metal in normal intermeshing stretching operation. With such a diagonal intermeshing stretcher, a presser disc 32 having the configuration of a helical gear would be used. The use of a diagonal intermeshing stretcher provides for a stretching force having force components in both the cross machine direction and the machine direction of the laminate.
The drive for the CD intermeshing stretcher typically operates both upper and lower intermeshing rollers except in the case of intermeshing stretching of materials with a relatively high coefficient of friction. The drive need not be antibacklash, however, because a small amount of machine direction misalignment or drive slippage will cause no problem.
The CD intermeshing elements are machined from solid material but can best be described as an alternating stack of two different diameter disks. In the preferred embodiment, the intermeshing disks would be 6″ in diameter, 0.031″ thick, and have a full radius on their edge. The spacer disks separating the intermeshing disks would be 5½″ in diameter and 0.069″ in thickness. Two rolls of this configuration would be able to be intermeshed up to 0.231″ leaving 0.019″ clearance for material on all sides. As with the diagonal intermeshing stretcher, this CD intermeshing element configuration would have a 0.100″ pitch.
The MD intermeshing stretching equipment is identical to the diagonal intermeshing stretch except for the design of the intermeshing rollers. The MD intermeshing rolls closely resemble fine pitch spur gears. In the preferred embodiment, the rolls have a 5.933″ diameter, 0.100″ pitch, 30 Diametral pitch, 14½° pressure angle, and are basically a long addendum, topped gear. A second pass was taken on these rolls with the gear hob offset 0.010″ to provide a narrowed tooth with more clearance. With about 0.090″ of engagement, this configuration will have about 0.010″ clearance on the sides for material thickness.
The above described diagonal or CD intermeshing stretchers may be employed with the pin-hole prevention apparatus of the present invention to produce the incrementally stretched film or laminate of non-woven fibrous web and microporous-formable film to form the microporous film products of this invention. For example, the stretching operation may be employed on an extrusion laminate of a non-woven fibrous web of staple fibers or spun-bonded filaments and microporous-formable thermoplastic film. In one of the unique aspects of this invention, a laminate of a non-woven fibrous web of spun-bonded filaments may be incrementally stretched to provide a very soft fibrous finish to the laminate that looks like cloth. The laminate of non-woven fibrous web and microporous-formable film is incrementally stretched using, for instance, the CD and/or MD intermeshing stretcher with one pass through the stretcher with a depth of roller engagement at about 0.060 inch to 0.120 inch at speeds from about 550 fpm to 1200 fpm or faster. The results of such incremental or intermesh stretching produces laminates that have excellent breatheability and liquid-barrier properties, yet provide superior bond strengths and soft cloth-like textures.
The microporous laminate typically employs a film having a gauge or a thickness between about 0.25 and 10 mils and, depending upon use, the film thickness will vary and, most preferably, in disposable applications is the order of about 0.25 to 2 mils in thickness. The non-woven fibrous webs of the laminated sheet normally have a weight of about 5 grams per square yard to 75 grams per square yard preferably about 20 to about 40 grams per square yard.
The following examples illustrate the method of making microporous film and laminates of this invention. In light of these examples and this further detailed description, it is apparent to a person of ordinary skill in the art that variations thereof may be made without departing from the scope of this invention.
EXAMPLES 1-5
Blends of LLDPE and LDPE having the compositions reported in the following TABLE 1 were extruded to form films and the films were then incrementally stretched to provide microporous films.
TABLE 1
Formulation (by wt.)
1
2
3
4
5
CaCO 3
44.2
44.2
44.2
44.2
44.2
LLDPE
44.1
44.9
41.9
41.9
41.9
LDPE
1.5
3.7
3.7
3.7
3.7
Others*
10.2
10.2
10.2
10.2
10.2
Screw
RPM
A
33
45
57
64
75
B
33
45
57
64
75
Basis wt. (gms/m 2 )
45
45
45
45
45
Gauge (mils)
2
2
2
2
2
Line Speed (fpm)
550
700
900
1000
1200
Air Knife (cfm/inch)
5-25
5-25
5-25
5-25
5-25
Web Stability
Poor
Good web stability without draw
gauge
resonance
control
with draw
resonance
*Other components include 2.5% by weight of a styrene-butadiene-styrene (SBS) triblock polymer, Shell Kraton 2122X, which is an SBS <50% by wt. + mineral oil <30% by wt., EVA copolymer <15% by wt., polystyrene <10% by wt., hydrocarbon resin <10% by wt., antioxidant/stabilizer <1% by wt., and hydrated amorphous silica <1% by wt.
Each of the formulations of 1-5 were extruded into films employing an extrusion apparatus. The formulations of Examples 1-5 were fed from an extruder through a slot die to form the extrudate into the nip of a rubber roll and a metal roll. The incoming webs of non-woven material were also introduced into the nip of the rolls. In Examples 1-5, the thermoplastic film was produced for subsequent incremental stretching to form the microporous film. As shown in TABLE 1, over speeds of about 550 fpm to 1200 fpm, a polyethylene film on the order of about 2 mils in thickness was made which is taken off the roller. The compressive force at the nip is controlled such that the film is made without pin-holing and without draw resonance in the case of Examples 2-5. The melt temperatures from the feed zone to the screw tip of extruders were maintained at about 400-430° F. with die temperatures of approximately 450° F. to extrude the precursor film around 2 mils (45 g/m 2 ).
As shown in TABLE 1, over speeds of about 550 fpm to 1200 fpm, a polyethylene film on the order of about 2 mils in thickness was made which is taken off the roller. The air knife has a length of about 120″ and an opening of about 0.035″-0.060″ and air is blown through the opening and against the extrudate at about 5 cfm/inch to 25 cfm/inch. The compressive force at the nip and the air knife are controlled such that the film is made without pin-holing and without draw resonance in the case of Examples 2-5. Where the LDPE was included in the composition at a level of 1.5% by weight, draw resonance was encountered at a line speed of 550 fpm. However, when the LDPE was included in the formulation at a level of 3.7% by weight with the LLDPE at a level of 44.1-44.9% by weight, film production was able to be achieved at high speeds greater than 550 fpm up to 1200 fpm without draw resonance. The melt temperatures from the feed zone to the screw tip of the extruders were maintained at about 400-430° F. with die temperatures of approximately 450° F. to extrude the precursor film around 2 mils (45 gms/m 2 ).
FIG. 10 is a graph demonstrating the line speeds for Examples 1-5 and the necessary screw speed. Example 1, which contained only 1.5% by weight of LDPE, resulted in a poor film gauge control with draw resonance even with the air knife. However, when the LDPE was increased to about 3.7% by weight, excellent web stability was achieved without draw resonance even when line speeds were increased to about 1200 fpm.
FIG. 11 is a graph demonstrating the moisture vapor transmission properties (MVTR) of both embossed and flat films resulting from incrementally stretching the precursor films of Examples 2-5 under different temperatures and stretch roller engagement conditions. The MVTRs for the embossed film on the order of about 1200-2400 gms/m 2 /day were achieved, whereas MVTRs for the flat film on the order of about 1900-3200 gms/m 2 /day were achieved. FIG. 12 shows the impact of the temperature of the CD preheat roller upon MVTR. The MVTR for the film varied between about 2000-2900 gms/m 2 /day with the roller preheat temperature between about 75-220 F. The embossed film was made with a metal embossing roller having a rectangular engraving of CD and MD lines with about 165-300 lines per inch. This pattern is disclosed, for example, in U.S. Pat. No. 4,376,147 which is incorporated herein by reference. This micro pattern provides a matte finish to the film but is undetectable to the naked eye.
Those skilled in the art will recognize that the exemplary embodiment illustrated in the drawings is not intended to limit the invention. Indeed, those skilled in the art will recognize that other alternative embodiments may be used without departing from the scope of the invention.
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The method and apparatus of the present invention prevents the formation of pin-holes during stretching of strip laminates in the cross machine direction. Pin-holes are prevented by creating slack areas along the length of the web where the edges of the non-woven strips meet with the polymer film, pressing the slack areas into the interdigital stretching rollers without stretching the slack areas, and stretching the remainder of the web in a typical manner. The slack regions are formed prior to interdigitation by, for example, formation of a furrow, a fold or a corrugation.
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FIELD OF THE INVENTION
[0001] This application relates to a portable apparatus for verifying the accuracy and consistency of test data produced by fuel cell test stations and for simulating some of the physical characteristics of a fuel cell. The apparatus can be used to calibrate each test station to a pre-defined test standard, and to experiment with new test setups without fear of damaging an expensive fuel cell.
BACKGROUND OF THE INVENTION
[0002] Test stations are used by developers and manufacturers of fuel cell systems to test new designs and materials and to monitor product life cycles. Such test stations include numerous subsystems, such as gas mixing modules, humidification units, water management systems, load banks, measuring devices and system controllers. Test stations control the physical characteristics of the reactants and cooling fluid entering a fuel cell, to simulate the various conditions that a fuel cell would encounter during real world operation. Typically, all fuel cells require three material inputs to operate: a fuel, an oxidant and a cooling fluid. The fuel (typically hydrogen) and oxidant (typically air) are delivered to the fuel cell in the form of heated, and humidified gas. The gas temperature, pressure, flow rate and humidity are all controlled from the test station. The coolant (typically de-ionized water) is delivered to the fuel cell for thermal control. Controllable properties of the coolant include temperature, pressure, flow rate, and conductivity.
[0003] With the delivery of the following inputs, a fuel cell produces an electric potential across its terminals, from which current can be drawn. The test stations apply varying electrical loads, and measure the subsequent fuel cell voltage. Test stations may also include integrated data acquisition and reporting hardware and software for analyzing test results.
[0004] The data generated by test stations is relied upon by product development engineers to test assumptions and hypotheses, and to assist in making product design decisions. Accordingly, if the data generated by a test station is faulty, this may result in flawed design or production decisions having potentially serious and expensive consequences. It is therefore imperative that test station data be as accurate and reliable as possible.
[0005] Many fuel cell developers and manufacturers employ multiple fuel cell test stations located at different locations on site. Often such test stations are manufactured by different suppliers and comprise different combinations of testing equipment. However, despite their design differences, fuel cell test stations generally control and measure many of the same properties. Problems can arise if a product designer suspects that some of the test stations are not producing accurate and consistent results (and hence the data generated by different stations is not readily comparable). Prior to the present invention there was no way to verify that the instrumentation of each test station was calibrated to the same standard and hence it was difficult to compare and characterize fuel cell stacks tested at different stations. Previously, data output verification could only be performed on one type of device measuring one physical characteristic on one station. For example, if an operator suspected that a flow meter was faulty, it would be necessary to physically remove the flow meter from the test station and conduct bench tests to verify its accuracy. Alternatively, diverter valves would be required to isolate the instrument from the rest of the test station. In either case instrument verification and re-calibration was a painstaking and time consuming exercise.
[0006] The present invention has been developed to provide an integrated testing apparatus for quickly verifying the accuracy of data outputted by fuel cell test stations. Additionally, the invention can be used to simulate the behavior of an actual fuel cell allowing for the development of fuel cell tests. This avoids risking a valuable fuel cell during test development. The apparatus is portable so that it may be conveniently transported between the different test station locations.
SUMMARY OF THE INVENTION
[0007] In accordance with aspects of the invention, a fuel cell test station verification, calibration and simulation apparatus is provided. The apparatus includes a plurality of inlets for connecting to the fuel cell stack or fuel processor interface of a test station. For example, the apparatus is connectable to the fuel supply, oxidant supply, nitrogen supply and coolant supply of the test station. The apparatus also includes a plurality of outlets, which are connectable to corresponding test station inlets, such as fuel, oxidant and coolant inputs. The apparatus comprises high quality, traceable instrumentation and a data acquisition and recording system. Depending upon the test results, data correction factors may be calculated for adjusting previously recorded test station data. The invention may also comprise a computer model of a simulated fuel cell and a means for changing the model's parameters.
[0008] An object of a first aspect of the present invention is to provide an improved fuel cell testing station verification, calibration and simulation system.
[0009] In accordance with this first aspect of the present invention there is provided a system for calibrating a fuel cell test station. The fuel cell test station has an interface for connection to at least one of a fuel cell, a fuel cell stack and a fuel processor to measure a plurality of physical characteristics associated therewith to obtain a plurality of station measurements. The system comprises: (a) a plurality of inlets for connecting to a plurality of interface outlets of the interface to receive a plurality of inflows therefrom; (b) a plurality of outlets for connecting to a plurality of interface inlets of the interface for discharging a plurality of outflows thereto; (c) a plurality of sensors associated with the plurality of inlets and plurality of outlets for measuring the plurality of physical characteristics of the plurality of inflows and the plurality of outflows to obtain a plurality of measurements for comparison with the plurality of station measurements; and, (d) a data processor for receiving and storing the plurality of measurements from the plurality of sensors and for comparing the plurality of measurements with the plurality of station measurements, the data processor being connected to the plurality of sensors by data transfer means
[0010] An object of a second aspect of the present invention is to provide an improved fuel cell testing station verification, calibration and simulation system.
[0011] In accordance with this second aspect of the present invention there is provided a method of calibrating a fuel cell test station. The fuel cell test station has an interface for connection to at least one of a fuel cell, a fuel cell stack and a fuel processor to measure a plurality of physical characteristics associated therewith to obtain a plurality of station measurements. The method comprises: (a) concurrently measuring the plurality of physical characteristics to obtain a plurality of measurements; (b) storing the plurality of measurements; and, (c) comparing the plurality of measurements with the plurality of station measurements to obtain an aggregate calibration of the fuel cell test station.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] In drawings which illustrates an embodiment of the invention but which should not be construed as restricting the spirit or scope of the invention in any way,
[0013] [0013]FIG. 1 is a piping and instrumentation diagram for a test station verification, calibration and simulation device according to one embodiment of the invention;
[0014] [0014]FIG. 2 is a schematic view showing a possible arrangement for the device of FIG. 1 (i.e. a Verification Test Cart (VTC)) adapted to interface with a fuel cell test station (i.e. Test Station (T/S));
[0015] [0015]FIG. 3 is a schematic diagram of a test station providing a context for implementing different aspects of the invention;
[0016] [0016]FIG. 4 is a schematic diagram of a fuel line of a test station verification, calibration and simulation device according to a second aspect of the invention;
[0017] [0017]FIG. 5 is a schematic diagram of an oxidant line of the test station verification, calibration and simulation device of FIG. 4; and
[0018] [0018]FIG. 6 is a schematic diagram of a coolant line of the test station verification, calibration and simulation device of FIG. 4
DETAILED DESCRIPTION OF THE INVENTION
[0019] As shown schematically in FIG. 1, this application relates to a test station verification, calibration and simulation apparatus 10 . Apparatus 10 is connectable to the fuel cell stack interface of a test station 40 (FIG. 3). In particular, apparatus 10 comprises a plurality of inlets 12 for receiving fuel, oxidant, nitrogen and coolant supplies from the test station 40 and a plurality of outlets 13 for delivering precisely measured amounts of physical characteristics to the test station 40 , such as fuel, oxidant, coolant and current inputs.
[0020] The apparatus 10 includes a plurality of high quality, traceable instrumentation for simultaneously or sequentially controlling, measuring and recording different physical characteristics. For example, as shown in FIG. 1, apparatus 10 may comprise manual or solenoid valves 14 , thermocouples 16 , pressure transducers 18 , dew point meters 20 , flow meters 22 , and resistivity meters 24 . Other physical parameter measuring devices may be provided, such as gas sample ports 25 and analyzers 26 (e.g. gas chromatographs). The various power inputs and outputs of a fuel cell are measured and controlled from the apparatus, as shown schematically in FIG. 2. As the reactant gases are provided to a fuel cell, a voltage is produced across the plates of each cell. This apparatus could provide a variable controlled DC power supply, connected to a resistor ladder to simulate the individual cell voltages of a fuel cell stack. An accurate current measuring device such as a shunt could be placed in the apparatus to test the current drawing calibration of the test station load box.
[0021] Power supplies for delivering precisely measured current or voltages to the test station may also be employed to simulate fuel cell stack voltages. On board heater hose 28 or other heaters are provided to heat gases or other reactants.
[0022] Preferably apparatus 10 includes computer hardware and software (FIG. 2) for recording a historical log of test data for each station including computer algorithms for calculating corrective factors if the test station data output is inaccurate. That is, the manual or solenoid valves 14 , thermocouples 16 , pressure transducers 18 , dew point meters 20 , flow meters 22 , and resistivity meters 24 are all connected to the computer system of FIG. 2, such that at any time the readings received provide an overall “snap shot” of the state of the test station. The historical data can also be used to track degradation of test instrumentation and controls over time so that test instruments can be replaced or recalibrated when readings deviate from predetermined standards beyond an acceptable range. Computer algorithms may also be provided for diagnosing problems with the test station based on a pattern of errors received. If the accuracy quotient falls outside a tolerable range the test station could be replaced or removed from service for replacement of faulty instrumentation or controls.
[0023] Referring to FIG. 2, there is illustrated in a block diagram a computer system 78 linked to the apparatus 10 by I/O system 88 The computer system 78 includes a verification test cart (VTC) data acquisition control and analysis PC 86 having a PC monitor 87 . The PC operates software, which controls the state of the apparatus 10 such that verification or fuel cell simulation can take place. During verification and calibration of the apparatus 10 , the PC 86 logs pertinent data points and automatically calculates corrective calibration values required for a particular test station. This calibration data can then be stored for historical purposes, used in comparison with an established calibration baseline, or compared to similar data taken from other test stations. In fuel cell simulation mode, the PC controls the various apparatus outputs to physically simulate the response conditions of a programmed fuel cell computer model (a virtual fuel cell). Various models simulating different types of fuel cells can be stored and retrieved to run the test station through a number of different scenarios.
[0024] As described above, all sensors and control information in the apparatus 10 are connected to the PC monitor via VTC instrumentation and control I/O system, which relays data to the PC 86 . Specifically, all of the instruments for controlling controllable physical characteristics of the flow, such as heaters, flow rate controllers, humidifiers and pressure controllers are connected to the I/O 88 to receive control inputs from the PC 86 .
[0025] Most fuel cell stations contain a load bank, shown as T/S load bank 80 in FIG. 2. Typically, load banks are used to simulate an electrical load, such as an electric motor or the power supplied to a home. In effect, a load bank is a large variable resistor. Similarly, most fuel cell test stations include a cell voltage monitor (CVM) such as T/S CVM 82 as shown in FIG. 2. Such cell voltage monitors typically measure the voltage outputted from each cell of a fuel cell stack being tested. These elements of the test station are linked to elements of the computer system. Specifically, a DC current supply 83 a provides a controllable DC current to verify the accuracy of the T/S load bank 80 or to calibrate the T/S load bank 80 . In addition, the DC current supply 83 a may also be controlled via I/O 88 from PC 86 to simulate an electrical current produced from a fuel cell.
[0026] Similarly, the DC voltage supply and resistor ladder 83 b provides a controllable DC voltage supply that can be used to simulate the electric potential created by a fuel cell. This voltage can be passed through a resistor ladder to simulate the voltages of the individual cells in a fuel cell stack. As all fuel cell test stations measure cell voltages using a CVM, a controllable DC supply can be used to calibrate the test station CVM 82 . Furthermore, the voltage supplied by the DC voltage supply 83 b can be controlled and varied as part of a fuel cell stack simulation.
[0027] The computer system also includes a shunt 84 . The shunt 84 is highly calibrated resistor, which can accurately measure current when placed in series with a current source. In the setup of FIG. 2, the T/S load bank 80 can use the shunt 84 to verify the accuracy and calibrate its load drawing capabilities.
[0028] In general, apparatus 10 employs very precise instrumentation to accurately measure the same physical characteristics as are commonly outputted from a test station. The test data can then be compared for calibration purposes, verification of control, and comparison to the calibration of another test station. Apparatus 10 makes it possible to easily calibrate each test station to a pre-defined test standard to ensure reliable and consistent test results. Apparatus 10 is preferably mounted on a mobile cart having caster wheels so that it may be easily transported between test sites.
[0029] Referring to FIG. 3, there is illustrated in a schematic diagram a test station 40 providing a suitable context in which to implement the present invention. As shown in FIG. 3, a fuel cell 42 may be linked to the test station for testing. Alternatively, the apparatus 10 may be linked to the test station 40 to test or calibrate the test station 40 , or, alternatively, to simulate a fuel cell in a test run of the test station 40 .
[0030] As shown in FIG. 3, the test station 40 comprises a fuel supply 44 for supplying fuel (hydrogen) to a fuel line 43 . Fuel line 43 includes a fuel flow control valve 45 for controlling the flow of fuel, a humidifier 46 for providing a desired level of humidification to the fuel and a heater 48 for heating the fuel to a desired temperature. The fuel is then supplied to the fuel cell (or, alternatively, to a fuel inlet in the plurality of inlets of the apparatus 10 ) at a test station fuel outlet 49 a . Fuel discharged from the fuel cell 42 (or, alternatively, discharged from the fuel outlet of the apparatus 10 ) is received in a fuel outlet line 51 at a test station fuel inlet 49 b . The pressure of this fuel is measured by a fuel pressure sensor 50 , before the fuel is discharged at fuel exhaust 52 .
[0031] Similarly, oxidant is supplied to oxidant input line 53 by oxidant supply 54 . The rate of flow of the oxidant (air) is controlled by oxidant flow controller 55 . The humidity and temperature of the oxidant are controlled by oxidant humidifier 56 and oxidant heater 58 respectively before the oxidant input line 53 supplies the oxidant to the fuel cell at a test station oxidant outlet 59 a . The fuel cell discharges the oxidant into oxidant outlet line 61 at a test station oxidant inlet 59 b . The pressure of the oxidant is measured by pressure sensors 60 before the oxidant is discharged at oxidant exhaust 62 . Similarly, coolant (water) is supplied to the coolant input line 63 by coolant supply 64 . The temperature and rate of flow of the coolant are then controlled by heater 66 and coolant flow controller 65 respectively before the coolant is provided to the fuel cell 42 at a test station coolant outlet 69 a . The coolant discharged from the fuel cell 42 is received by the coolant outlet line 71 at a test station coolant inlet 69 b . A portion of the coolant in the coolant output line 71 is redirected to a coolant reservoir 70 which reconnects to the coolant inlet line 63 upstream from the heater 66 and coolant flow controller 65 The remainder of the coolant is discharged at the coolant drain 72 .
[0032] According to another aspect of the invention, the behavior of an actual fuel cell can be simulated allowing for the development of fuel cell tests. This avoids risking a valuable fuel cell during test development. To this end, the invention may comprise a computer model of a simulated fuel cell as well as means for changing the model's parameter.
[0033] Referring to FIGS. 4, 5 and 6 there are illustrated in schematic diagrams a fuel supply line, an oxidant supply line and a coolant supply line respectively of a an apparatus in accordance with a further aspect of the invention. The fuel supply line receives fuel (hydrogen) from a fuel inlet 100 . The fuel passes through an isolation valve 102 , which, if desired, can be closed to shut off fuel flow, while permitting flow of oxidant and coolant. The pressure, temperature and humidity of the fuel are measured by pressure sensor 104 , temperature sensor 106 , and humidity sensor 108 respectively. The rate of flow of fuel is controlled by first flow control valve 110 , and this rate of flow is then measured by flow meter 112 . The first flow control valve 110 can be used to simulate varying pressure drops associated with different fuel cell architectures. This enables users of the test station to tune pressure control loops under different conditions without fear of damaging the fuel cell.
[0034] A bleed line 113 can be used to draw some of the fuel off from the fuel line. This is controlled by a second flow control valve 114 , and is used to simulate the normal consumption of fuel by the chemical reaction within the fuel cell. Combined with the first control valve 110 , this provides the feedback required to tune the pressure control loop of a test station. The bleed line 113 can also be connected to a gas chromatograph and used to verify the composition of the fuel.
[0035] A heater 116 is provided in the fuel line downstream from the branch where the bleed line 113 bleeds off fuel. This heater can be used to simulate the additional heat added to the system by the exothermal chemical reactions taking place within a fuel cell. Furthermore, the heater 116 can be used to prevent condensation from forming within the apparatus lines. Downstream from heater 116 , the fuel is discharged to the test station at a fuel outlet 118 .
[0036] Referring to FIG. 5, the oxidant supply line is illustrated. The oxidant supply line receives oxidant (air) from an oxidant inlet 120 . The oxidant passes through an isolation valve 122 , which, if desired, can be closed to shut off oxidant flow, while permitting flow of fuel and coolant. The pressure, temperature and humidity of the oxidant are measured by pressure sensor 124 , temperature sensor 126 , and humidity sensor 128 respectively. The rate of flow of oxidant is controlled by first flow control valve 130 , and this rate of flow is then measured by flow meter 132 . The first flow control valve 130 can be used to simulate varying pressure drops associated with different fuel cell architectures. This enables users of the test station to tune pressure control loops under different conditions without fear of damaging the fuel cell.
[0037] A bleed line 133 can be used to draw some of the oxidant off from the oxidant line. This is controlled by a second flow control valve 134 , and is used to simulate the normal consumption of oxidant by the chemical reaction within the fuel cell. Combined with the first control valve 130 , this provides the feedback required to tune the pressure control loop of a test station. The bleed line 133 can also be connected to a gas chromatograph and used to verify the composition of the oxidant.
[0038] A heater 136 is provided in the oxidant line downstream from the branch where the bleed line 113 bleeds off oxidant. This heater 136 can be used to simulate the additional heat added to the system by the exothermal chemical reactions taking place within a fuel cell. Furthermore, the heater 136 can be used to prevent condensation from forming within the apparatus lines. Downstream from heater 136 , the oxidant is discharged to the test station at an oxidant outlet 138 .
[0039] Referring to FIG. 6, the coolant supply line is illustrated. The coolant supply line receives coolant (water) from a coolant inlet 140 . The coolant passes through an isolation valve 142 , which, if desired, can be closed to shut off coolant flow, while permitting flow of fuel and oxidant. The pressure, temperature and conductivity of the coolant are measured by pressure sensor 146 , temperature sensor 148 , and conductivity sensor 144 respectively. The rate of flow of coolant is controlled by first flow control valve 150 , and this rate of flow is then measured by flow meter 152 . The first flow control valve 150 can be used to simulate varying pressure drops associated with different fuel cell architectures. This enables users of the test station to tune pressure control loops under different conditions without fear of damaging the fuel cell. A heater 154 is provided in the coolant line downstream from flow meter 152 . This heater 154 can be used to simulate the additional heat added to the system by the exothermal chemical reactions taking place within a fuel cell. Downstream from heater 154 , the coolant is discharged to the test station at a coolant outlet 156 .
[0040] Other variations and modifications of the invention are possible. For example, to reduce the number of components required, thereby reducing the cost and weight of the apparatus, different lines may be combined into one line. That is, the line for the oxidant and fuel might be combined into one line, such that only one set of sensors and control devices is required for both the oxidant and fuel. Isolation valves upstream of this common line would be provided for both the fuel feeder line and the oxidant feeder line to shut off the flow of fuel, say, when the testing station was being calibrated relative to the physical characteristics of the oxidant. All such modifications or variations are believed to be within the sphere and scope of the invention as defined by the claims appended hereto.
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A method and system for calibrating a fuel cell test station. The fuel cell test station has an interface for connection to at least one of a fuel cell, a fuel cell stack and a fuel processor to measure a plurality of physical characteristics associated therewith to obtain a plurality of station measurements. The method and system involve: (a) concurrently measuring the plurality of physical characteristics to obtain a plurality of measurements; (b) storing the plurality of measurements; and, (c) comparing the plurality of measurements with the plurality of station measurements to obtain an aggregate calibration of the fuel cell test station.
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