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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a continuation oil U.S. patent application Ser. No. 09/756,991, filed Jan. 8, 2001, which is a divisional of U.S. patent application Ser. No. 09/338,179, filed Jun. 22, 1999, now U.S. Pat. No. 6,222,030, which was a continuation-in-part of U.S. patent application Ser. No. 09/128,052, filed Aug. 3, 1998, abandoned, all of which are incorporated in their entireties by reference herein.
TECHNICAL FIELD
[0002] The present invention relates generally to nucleic acid chemistry and to the chemical synthesis of oligonucleotides. More particularly, the invention relates to an improved method for synthesizing oligonucleotides wherein carbonates are used as hydroxyl-protecting groups and “alpha-effect” nucleophiles such as peroxides are used in the deprotection thereof. The invention has utility in the fields of biochemistry, molecular biology and pharmacology, and in medical diagnostic and screening technologies.
BACKGROUND
[0003] Solid phase chemical synthesis of DNA fragments is routinely performed using protected nucleoside phosphoramidites. S. L. Beaucage et al. (1981) Tetrahedron Lett. 22:1859. In this approach, the 3′-hydroxyl group of an initial 5′-protected nucleoside is first covalently attached the polymer support. R. C. Pless et al. (1975) Nucleic Acids Res. 2:773 (1975). Synthesis of the oligonucleotide then proceeds by deprotection of the 5′-hydroxyl group of the attached nucleoside, followed by coupling of an incoming nucleoside-3′phosphoramidite to the deprotected hydroxyl group. M. D. Matteucci et al. (1981) J. Am. Chem. Soc. 103:3185. The resulting phosphite triester is finally oxidized to a phosphorotriester to complete the internucleotide bond. R. L. Letsinger et al. (1976) J. Am. Chem. Soc. 98:3655. The steps of deprotection, coupling and oxidation are repeated until an oligonucleotide of the desired length and sequence is obtained. This process is illustrated schematically in FIG. 1 (wherein “B” represents a purine or pyrimidine base, “DMT” represents dimethoxytrityl and “iPR” represents isopropyl.
[0004] The chemical group conventionally used for the protection of nucleoside 5′-hydroxyls is dimethoxytrityl (“DMT”), which is removable with acid. H. G. Khorana (1968) Pure Appl. Chem. 17:349; M. Smith et al. (1962) J. Am. Chem. Soc. 84:430. This acid-labile protecting group provides a number of advantages for working with both nucleosides and oligonucleotides. For example, the DMT group can be introduced onto a nucleoside regioselectively and in high yield. E. I. Brown et al. (1979) Methods in Enzymol. 68:109. Also, the lipophilicity of the DMT group greatly increases the solubility of nucleosides in organic solvents and the carbocation resulting from acidic deprotection gives a strong chromophore, which can be used to indirectly monitor coupling efficiency. M. D. Matteucci et al. (1980) Tetrahedron Lett. 21:719. In addition, the hydrophobicity of the group can be used to aid separation on reverse-phase HPLC. C. Becker et al. (1985) J. Chromatogr. 326:219.
[0005] However, use of DMT as hydroxyl-protecting group in oligonucleotide synthesis is also problematic. The N-glycosidic linkages of oligodeoxyribonucleotides are susceptible to acid catalyzed cleavage (N. K. Kochetkov et al. Organic Chemistry of Nucleic Acids (New York: Plenum Press, 1972)), and even when the protocol is optimized, recurrent removal of the DMT group with acid during oligonucleotide synthesis results in depurination. H. Shaller et al. (1963) J. Am. Chem. Soc. 85:3821. The N-6-benzoyl-protected deoxyadenosine nucleotide is especially susceptible to glycosidic cleavage, resulting in a substantially reduced yield of the final olignucleotide J. W. Efcavitch et al. (1985) Nucleosides & Nucleotides 4:267. Attempts have been made to address the problem of acid-catalyzed depurination utilizing alternative mixtures of acids and various solvents; see, for example, E. Sonveaux (1986) Bioorganic Chem. 14:274. However, this approach has met with limited success. L. J. McBride et al. (1986) J. Am. Chem. Soc. 108:2040.
[0006] Conventional synthesis of oligonucleotides using DMT as a protecting group is problematic in other ways as well. For example, cleavage of the DMT group under acidic conditions gives rise to the resonance-stabilized and long-lived bis(p-anisyl)phenylmethyl carbocation. P. T. Gilham et al. (1959) J. Am. Chem. Soc. 81:4647. Protection and deprotection of hydroxyl groups with DMT are thus readily reversible reactions, resulting in side reactions during oligonucleotide synthesis and a lower yield than might otherwise be obtained. To circumvent such problems, large excesses of acid are used with DMT to achieve quantitative deprotection. As bed volume of the polymer is increased in larger scale synthesis, increasingly greater quantities of acid are required. The acid-catalyzed depurination which occurs during the synthesis of oligodeoxyribonucleotides is thus increased by the scale of synthesis. M. H. Caruthers et al., in Genetic Engineering: Principles and Methods , J. K. Setlow et al., Eds. (New York: Plenum Press, 1982).
[0007] Considerable effort has been directed to developing 5′-O-protecting, groups which can be removed under non-acidic conditions. For example, R. L. Letsinger et al. (1967) J. Am. Chem. Soc. 89:7147, describe use of a hydrazine-labile benzoyl-propionyl group, and J. F. M. deRooij et al. (1979) Real, Track, Chain, Pays - Bas. 98:537, describe using the hydrazine-labile levulinyl ester for 5′-OH protection (see also S. Iwai et al. (1988) Tetrahedron Lett. 29:5383; and S. Iwai et al. (1988) Nucleic Acids Res. 16:9443). However, the cross-reactivity of hydrazine with pyrimidine nucleotides (as described in F. Baron et al. (1955) J. Chem. Soc. 2855 and in V. Habermann (1962) Biochem. Biophys. Acta 55:999), the poor selectivity of levulinic anhydride and hydrazine cleavage of N-acyl protecting groups (R. L. Letsinger et al. (1968), Tetrahedron Lett. 22:2621) have made these approaches impractical. H. Seliger et al. (1985), Nucleosides & Nucleotides 4:153, describes the 5′-O-phenyl-azophenyl carbonyl (“PAPco”) group, which is removed by a two-step procedure involving transesterification followed by β-elimination; however, unexpectedly low and non-reproducible yields resulted. Fukuda et al. (1988) Nucleic Acids Res. Symposium Ser. 19, 13, and C. Lehmann et al. (1989) Nucleic Acids Res. 17:2389, describe application of the 9-fluorenylmethylcarbonate (“Fmoc”) group for 5′-protection. C. Lehmann et al. (1989) report reasonable yields for the synthesis of oligonucleotides up to 20 nucleotides in length. The basic conditions required for complete deprotection of the Fmoc group, however, lead to problems with protecting group compatibility. Similarly, R. L. Letsinger et al. (1967), J. Am. Chem. Soc. 32:296, describe using p-nitrophenyloxycarbonyl group for 5′-hydroxyl protection. In all of the procedures described above utilizing base-labile 5′-O-protecting groups, the requirements of high basicity and long deprotection times have severely limited their application for routine synthesis of oligonucleotides.
[0008] Still an additional drawback associated with conventional oligonucleotide synthesis using DMT as a hydroxyl-protecting group is the necessity) of multiple steps, particularly the post-synthetic deprotection step in which the DMT group is removed following oxidation of the internucleotide phosphite triester linkage to a phosphorotriester. It would be desirable to work with a hydroxyl-protecting group that could be removed via oxidation, such that the final two steps involved in nucleotide addition, namely oxidation and deprotection, could be combined.
[0009] The problems associated with the use of DMT are exacerbated in solid phase oligonucleotide synthesis where “microscale” parallel reactions are taking place on a very dense, packed surface. Applications in the field of genomics and high throughput screening have fueled the demand for precise chemistry in such a context. Thus, increasingly stringent demands are placed on the chemical synthesis cycle as it was originally conceived, and the problems associated with conventional methods for synthesizing oligonucleotides are rising to unacceptable levels in these expanded applications.
[0010] The invention is this addressed to the aforementioned deficiencies in the art, and provides a novel method for synthesizing oligonucleotides, wherein the method has numerous advantages relative to prior methods such as those discussed above. The novel method involves the use of neutral or mildly basic conditions to remove hydroxyl-protecting groups, such that acid-induced depurination is avoided. In addition, the reagents used provide for irreversible deprotection, significantly reducing the likelihood of unwanted side reactions and increasing the overall yield of the desired product. The method provides for simultaneous oxidation of the internucleoside phosphite triester linkage and removal of the hydroxyl-protecting group, eliminating the extra step present in conventional processes for synthesizing oligonucleotides; the method also avoids the extra step of removing exocyclic amine protecting groups, as the reagents used for hydroxyl group deprotection substantially remove exocyclic amine protecting groups. In addition, the method can be used in connection with fluorescent or other readily detectable protecting groups, enabling monitoring of individual reaction steps. Further, the method is useful in carrying out either 3′-to-5′ synthesis or 5′-to-3′ synthesis. Finally, because of the far more precise chemistry enabled by the present invention, the method readily lends itself to the highly parallel microscale synthesis of oligonucleotides.
SUMMARY OF THE INVENTION
[0011] It is accordingly a primary object of the invention to provide a novel method for synthesizing oligonucleotides which addresses and overcomes the above-mentioned disadvantages of the prior art.
[0012] It is another object of the invention to provide a novel method for synthesizing oligonucleotides in which individual nucleoside monomers are added to a growing oligonucleotide chain using carbonates as hydroxyl-protecting groups and “alpha effect” nucleophiles as deprotecting reagents.
[0013] It is still another object of the invention to provide such a method in which hydroxyl group deprotection and oxidation of the internucleotide phosphite triester linkage are carried out simultaneously, in a single step.
[0014] It is yet another object of the invention to provide such a method in which deprotection and oxidation are conducted in aqueous solution at neutral or mildly basic pH.
[0015] It is an additional object of the invention to provide such a method in which removal of hydroxyl protecting groups during oligonucleotide synthesis is irreversible.
[0016] It is a further object of the invention to provide such a method in which the desired oligonucleotide can be synthesized in either the 3′-to-5′ direction or the 5-to-3′ direction.
[0017] Still a further object of the invention is to provide such a method in which individual oligonucleotides are synthesized within the context of a highly dense, substantially parallel oligonucleotide array on a substrate surface.
[0018] Still an additional object of the invention is to provide nucleoside reagents useful in conjunction with the novel synthetic methods.
[0019] Additional objects, advantages and novel features of the invention will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the followings or may be learned by practice of the invention.
[0020] The invention is premised on the discovery that rapid and selective removal of suitable 5-OH or 3′-OH protecting groups following phosphoramidite condensation can be achieved by employing nucleophiles, and particularly peroxy anions, that exhibit an “alpha effect” under neutral or mildly basic conditions. Further, it has now been discovered that rapid and selective deprotection can be achieved under such conditions by employing carbonate groups for 5′-OH or 3′-OH protection. Deprotection of nucleoside carbonates using peroxy anions can be conducted in aqueous solution, at neutral or mild pal, resulting in quantitative removal of the carbonate group and concomitant and quantitative oxidation of the internucleotide phosphite triester bond. Oligonucleotides synthesized using the novel methodology can be isolated in high yield and substantially free of detectable nucleoside modifications.
[0021] The term “alpha effect,” as in an “alpha effect” nucleophilic deprotection reagent, is used to refer to an enhancement of nucleophilicity that is found when the atom adjacent a nucleophilic site bears a lone pair of electrons. As the term is used herein, a nucleophile is said to exhibit an “alpha effect” if it displays a positive deviation from a Brønsted-type nucleophilicity plot. S. Hoz et al. (1985) Israel J. Chem. 26:313. See also, J. D. Aubort et al. (1970) Chem. Comm. 1378; J. M. Brown et al. (1979) J. Chem. Soc. Chem. Comm. 171; E. Buncel et al. (1982) J. Am. Chem. Soc. 104:4896 J. O. Edwards et al. (1962) J. Amer. Chem. Soc. 84:16; J. D. Evanseck et al. (1987) J. Am. Chem. Soc. 109:2349. The magnitude of the alpha effect is dependent upon the electrophile which is paired with the specific nucleophile. J. E. Melsaac, Jr. et al. (1972), J. Org. Chem. 37:1037. Peroxy anions are example of nucleophiles which exhibit strong alpha effects.
[0022] In one general aspect, the invention features a method, in an oligonucleotide synthesis, for removing, a protecting group from a protected nucleoside, by reacting the protected nucleoside or protected nucleotide with a nucleophile that exhibits an alpha effect at conditions of mildly basic pH, and particularly at conditions of pH 10 or less.
[0023] The invention provides for efficient solid-phase synthesis of oligonucleotides of lengths up to 25 nucleotides and greater. Treatment using an alpha effect nucleophile according to the invention for removal of carbonate protecting groups is irreversible, resulting in breakdown of the carbonate and formation of CO 2 . Moreover, because such treatment results in concomitant oxidation of the internucleotide bond and substantial removal of exocyclic amine protecting groups, the method of the invention obviates the need for a separate oxidation step and a post-synthesis deprotection step to remove any exocyclic amine protecting groups that may be used.
[0024] In another general aspect, the invention features a method for making an oligonucleotide array made up of array features each presenting a specified oligonucleotide sequence at an address on an array substrate, by first treating the array substrate to protect the hydroxyl moieties on the derivatized surface from reaction with phosphoramidites, then carrying out the steps of (a) applying droplets of an alpha elect nucleophile to effect deprotection of hydroxyl moieties at selected addresses, and (b) flooding the array substrate with a medium containing a selected protected phosphoramidite to permit couplings of the selected phosphoramidite onto the deprotected hydroxyl moieties at the selected addresses, and repeating the steps (a) and (b) to initiate and to sequentially build up oligonucleotides having the desired sequences at the selected addresses to complete the array features. In a variation on the aforementioned method, the droplets applied may comprise the protected phosphoramidite, and the alpha effect nucleophile may be used to flood the array substrate.
[0025] In the array construction method according to the invention, the deprotection reagents are aqueous, allowing for good droplet formation on a wide variety of array substrate surfaces. Moreover, because the selection of features employs aqueous media, small-scale discrete droplet application onto specified array addresses can be carried out by adaptation of techniques for reproducible fine droplet deposition from printing technologies. Further, as noted above, the synthesis reaction provides irreversible deprotection resulting in evolution of CO 2 , and thus quantitative removal of protecting groups within each droplet may be achieved. The phosphoramidite are carried out in bulk, employing an excess of the phosphoramidite during the coupling step (b), allowing for exclusion of water by action of the excess phosphoramidite as a desiccant.
DETAILED DESCRIPTION OF THE FIGURES
[0026] FIG. 1 schematically illustrates conventional 3′-to-5′ oligonucleotide synthesis using DMT as a 5′-OH protecting group, and separate deprotection and oxidation steps.
[0027] FIG. 2 schematically illustrates 3′-to-5′ oligonucleotide synthesis using the method of the invention.
[0028] FIGS. 3A and 3B compare the conventional deprotection reaction in which DMT is used as a hydroxyl-protecting group ( FIG. 3A ) and the deprotection reaction in which the reagents of the invention are employed ( FIG. 3B ).
[0029] FIG. 4 schematically illustrates a method for synthesizing a 5′-carbonate-3′-phosphoramidite monomer of the invention.
[0030] FIG. 5 schematically illustrates a method for synthesizing a 3′-carbonate-5′-phosphoramidite monomer of the invention.
[0031] FIG. 6 sets forth the HPLC results obtained for a mixed-sequence oligonucleotide synthesized in Example 4, part (D).
[0032] FIG. 7 sets forth the MALDI TOF results obtained for the same mixed-sequence oligonucleotide.
DETAILED DESCRIPTION OF THE INVENTION
[0033] Definitions and Nomenclature:
[0034] It is to be understood that unless otherwise indicated, this invention is not limited to specific reagents, reaction conditions, synthetic steps, or the like, as such may vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting.
[0035] It must be noted that, as used in the specification and the appended claims, the singular forms “a” “an” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a protecting group” includes combinations of protecting groups, reference to “a nucleoside” includes combinations of nucleosides, and the like. Similarly, reference to “a substituent” as in a compound substituted with “a substituent” includes the possibility of substitution with more than one substituent, wherein the substituents may be the same or different.
[0036] In this specification and in the claims which follow, reference will be made to a number of terms which shall be defined to have the following, meanings:
[0037] The term “alkyl” as used herein, unless otherwise specified, refers to a saturated straight chain, branched or cyclic hydrocarbon group of 1 to 24, typically 1-12, carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, 1-butyl, pentyl, cyclopentyl, isopentyl, neopentyl, hexyl, isohexyl, cyclohexyl, 3-methylpentyl, 2,2-dimethylbutyl, and 2,3-dimethylbutyl. The term “lower alkyl” intends an alkyl group of one to six carbon atoms, and includes, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, pentyl, cyclopentyl, isopentyl, neopentyl, hexyl, isohexyl, cyclohexyl, 3-methylpentyl, 2,2 dimethylbutyl, and 2,3-dimethylbutyl. The term “cycloalkyl” refers to cyclic alkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl and cyclooctyl.
[0038] The term “alkenyl” as used herein, unless otherwise specified, refers to a branched, unbranched or cyclic (in the case of C 5 and C 6 ) hydrocarbon group of 2 to 24, typically 2 to 12, carbon atoms containing at least one double bond, such as ethenyl, vinyl, allyl, octenyl, decenyl, and the like. The term “lower alkenyl” intends an alkenyl group of two to six carbon atoms, and specifically includes vinyl and allyl. The term “cycloalkenyl” refers to cyclic alkenyl groups.
[0039] The term “alkynyl” as used herein, unless otherwise specified, refers to a branched or unbranched hydrocarbon group of 2 to 24, typically 2 to 12, carbon atoms containing at least one triple bond, such as acetylenyl, ethynyl, n-propynyl, isopropynyl, n-butynyl, isobutynyl, t-butynyl, octynyl, decynyl and the like. The term “lower alkynyl” intends an alkynyl group of two to six carbon atoms, and includes, for example, acetylenyl and propynyl, and the term “cycloalkynyl” refers to cyclic alkynyl groups.
[0040] The term “alkynyl” as used herein refers to an aromatic species containing, 1 to 5 aromatic rings, either fused or linked, and either unsubstituted or substituted with 1 or more substituents typically selected from the group consisting of amino, halogen and lower alkyl. Preferred aryl substituents contain 1 to 3 fused aromatic rings, and particularly preferred alkyl substituents contain 1 aromatic ring or 2 fused aromatic rings. Aromatic groups herein may or may not be heterocyclic. The term “aralkyl” intends a moiety containing both alkyl and aryl species, typically containing less than about 24 carbon atoms, and more typically less than about 12 carbon atoms in the alkyl segment of the moiety, and typically containing 1 to 5 aromatic rings. The term “aralkyl” will usually be used to refer to aryl-substituted alkyl groups. The term “aralkylene” will be used in a similar manner to refer to moieties containing both alkylene and aryl species, typically containing less than about 24 carbon atoms in the alkylene portion and 1 to 5 aromatic rings in the aryl portion, and typically less substituted alkylene. Exemplary aralkyl groups have the structure —(CH 2 ) j —Ar wherein j is an integer in the range of 1 to 24, more typically 1 to 6, and Ar is a monocyclic aryl moiety.
[0041] The term “electron withdrawing” denotes the tendency of a substituent to attract valence electrons of the molecule of which it is a part, i.e., an electron-withdrawing substituent is electronegative.
[0042] The term “heterocyclic” refers to a five- or six-membered monocyclic structure or to an eight- to eleven-membered bicyclic structure which is either saturated or unsaturated. The heterocyclic groups herein may be aliphatic or aromatic. Each heterocycle consists of carbon atoms and from one to four heteroatoms selected from the group consisting of nitrogen, oxygen and sulfur. As used herein, the terms “nitrogen heteroatoms” and “sulfur heteroatoms” include any oxidized form of nitrogen and sulfur, and the quaternized form of any basic nitrogen. Examples of heterocyclic groups include piperidinyl, morpholinyl and pyrrolidinyl.
[0043] The term “halo” or “halogen” is used in its conventional sense to refer to a chloro, bromo, fluoro or iodo substituent.
[0044] As used herein, the term “oligonucleotide” shall be generic to polydeoxynucleotides (containing 2-deoxy-D-ribose), to polyribonucleotides (containing D-ribose), to any other type of polynucleotide which is an N-glycoside of a purine or pyrimidine base, and to other polymers containing nonnucleotidic backbones, providing that the polymers contain nucleobases in a configuration which allows for base pairing and base stacking, such as is found in DNA and RNA.
[0045] It will be appreciated that, as used herein the terms “nucleoside” and “nucleotide” will include those moieties which contain not only the known purine and pyrimidine bases, but also modified purine and pyrimidine bases and other heterocyclic bases which have been modified (these moieties are sometimes referred to herein, collectively, as “purine and pyrimidine bases and analogs thereof”). Such modification include methylated purines or pyrimidines, acylated purifies or pyrimidines, and the like.
[0046] By “protecting group” as used herein is meant a species which prevents a segment of a molecule from undergoing a specific chemical reaction, but which is removable from the molecule following completion of that reaction. This is in contrast to a “capping group,” which permanently binds to a segment of a molecule to prevent any further chemical transformation of that segment.
[0047] “Optional” or “optionally” means that the subsequently described circumstance may or may not occur, so that the description includes instances where the circumstance occurs and instances where it does not. For example, the phrase “optionally substituted” means that a non-hydrogen substituent may or may not be present, and, thus, the description includes structures wherein a non-hydrogen substituent is present and structures wherein a non-hydrogen substituent is not present.
[0048] Oligonucleotide Synthesis Using Carbonate Protection and Irreversible Nucleophilic Deprotection:
[0049] In a first embodiment, the invention pertains to a method for synthesizing an oligonucleotide on a solid support, wherein a carbonate is used as a hydroxyl-protecting group and an alpha effect nucleophile is used to bring about deprotection. The novel synthesis is based on a simple, two-step method of (1) coupling a hydroxyl-protected nucleoside monomer to a growing oligonucleotide chain, and (2) deprotecting the product, under neutral or mildly basic conditions, using an alpha effect nucleophilic reagent that also oxidizes the internucleotide linkage to give a phosphotriester bond. The coupling and deprotection/oxidation steps are repeated as necessary to give an oligonucleotide having a desired sequence and length.
[0050] In the initial step of the synthesis, then, an unprotected nucleoside is covalently attached to a solid support to serve as the starting point for oligonucleotide synthesis. The nucleoside may be bound to the support through its 3′-hydroxyl group or its 5′-hydroxyl group, but is typically bound through the 3′-hydroxyl group. A second nucleoside monomer is then coupled to the free hydroxyl group of the support-bound initial monomer, wherein for 3′-to-5′ oligonucleotide synthesis, the second nucleoside monomer has a phosphorus derivative such as a phosphoramidite at the 3′ position and a carbonate protecting group at the 5′ position, and alternatively, for 5′-to-3′ oligonucleotide synthesis the second nucleoside monomer has a phosphorus derivative at the 5′ position and a carbonate protecting group at the 3′ position. This coupling reaction gives rise to a newly formed phosphite triester bond between the initial nucleoside monomer and the added monomer, with the carbonate-protected hydroxyl group intact. In the second step of the synthesis, the carbonate group is removed with an alpha effect nucleophile that also serves to oxidize the phosphite triester linkage to the desired phosphotriester.
[0051] More specifically, for 3′-to-5′ synthesis, a support-bound nucleoside monomer is provided having the structure (I)
wherein:
◯ represents the solid support or a support-bound oligonucleotide chain;
R is hydrido or hydroxyl, wherein when R is hydrido, the support-bound nucleoside is a deoxyribonucleoside, as will be present in DNA synthesis, and when R is hydroxyl, the support-bound nucleoside is a ribonucleoside, as will be present in RNA synthesis; and
B is a purine or pyrimidine base. The purine or pyrimidine base may be conventional, e.g., adenine (A), thymine (T), cytosine (C), guanine (G) or uracil (U), or a protected form thereof, e.g., wherein the base is protected with a protecting group such as acetyl, difluoroacetyl, trifluoroacetyl, isobutyryl, benzoyl, or the like. The purine or pyrimidine base may also be an analog of the foregoing; suitable analogs will be known to those skilled in the art and are described in the pertinent texts and literature. Common analogs include, but are not limited to, 1-methyladenine, 2-methyladenine, N 6 -methyladenine, N 6 -isopentyladenine, 2-methylthio-N 6 -isopentyladenine, N,N-dimethyladenine, 8-bromoadenine, 2-thiocytosine, 3-methylcytosine, 5-methylcytosine, 5-ethylcytosine, 4-acetylcytosine, 1-methylguanine, 2-methylguanine, 7-methylguanine, 2,2-dimethylguanine, 8-bromoguanine, 8-chloroguanine, 8-aminoguanine, 8-methylguanine, 8-thioguanine, 5-fluorouracil, 5-bromouracil, 5-chlorouracil, 5-iodouracil, 5-ethyluracil, 5-propyluracil, 5-methocyuracil, 5-hydroxymethyluracil, 5-(carboxyhydroxymethyl)uracil, 5-(methylaminomethyl)uracil, 5-(carboxymethylaminomethyl)-uracil, 2-thiouracil, 5-methyl-2-thiouracil 5-(2-bromovinyl)uracil, uracil-5-oxyacetic acid, uracil-5-oxyacetic acid methyl ester, pseudouracil, 1-methylpseudouracil, queosine, inosine, 1-methylinosine, hypoxanthine, xanthine, 2-aminopurine, 6-hydroxyaminopurine, 6-thiopurine and 2,6-diaminopurine.
[0052] The protected monomer to be added has the structure of formula (II)
in which B and R are as defined above with respect to the support-bound nucleoside of structural formula (I), and R 1 is COOR 3 , such that a carbonate group —OCOOR 3 is present at the 5′ position. R 3 is generally substituted or unsubstituted hydrocarbyl, including alkyl, aryl, aralkyl, alkaryl, cycloalkyl, alkenyl, cycloalkenyl, alkynyl, cycloalkynyl, optionally containing one or more nonhydrocarbyl linkages such as ether linkages, thioether linkages, oxo linkages, amine and imine linkages, and optionally substituted on one or more available carbon atoms with a nonhydrocarbyl substituent such as cyano, nitro, halo, or the like. Preferred carbonate groups —OCOOR 3 are aryl carbonates, i.e., R 3 is aryl. Suitable aryl carbonates include, for example, o-nitrophenylcarbonyl, p-phenylazophenylcarbonyl, phenylcarbonyl, p-chlorophenylcarbonyl, 5′-(α-methyl-2-nitropiperonyl)oxycarbonyl (“MeNPOC”), and 9-fluorenylmethylcarbonyl (“Fmoc”). Particularly preferred aryl carbonates have the structure Ar-L-O—(CO)—O— wherein Ar is an aromatic moiety, typically a monocyclic aromatic moiety such as a phenyl group, optionally substituted with one or more electron-withdrawing substituents such as halo, nitro, cyano, or the like, and L, is a lower alkylene linkage. Preferred alkyl carbonate substituents are fluorinated alkyl carbonates such as 2,2,2-trichloro-1,1-dimethylcarbonyl (“TCBOC”) and cyano-substituted alkyl carbonates such as 1,1-dimethyl-2-cyanoethyl carbonate
[0053] R 3 may also be a fluorescent or colored moiety. Preferably, in this embodiment, R 3 becomes fluorescent or colored upon cleavage of the carbonate —OCOOR 3 , but is neither fluorescent nor colored when bound to the nucleoside in carbonate form. In this way, when the carbonate protecting group R 1 is removed, the reaction may be monitored by detecting a fluorescent or colored cleavage product. Alternatively, R 3 may be fluorescent or colored when bound to the nucleoside in carbonate form, such that the presence of the newly attached monomer can be immediately detected. Examples of fluorescent and colorimetric species that may be employed include, but are not limited to: xanthenes such as fluoresceins, eosins and erythrosins, with preferred fluorescein compounds exemplified by 6-carboxy-fluorescein, 5- and 6-carboxy-4,7-dichlorofluorescein, 2′,7′-dimethoxy-5- and 6-carboxy-4,7-dichlorofluorescein, 2′,7′-dimethoxy-4′,5′-dichloro-5- and 6-carboxyfluorescein, 2′,7′-dimethoxy-4′,5′-dichloro-5- and 6-carboxy-4,7-dichlorofluorescein, 1′,2′,7′,8′-dibenzo-5- and 6-carboxy-4,7-dichlorofluorescein, 2′,7′-dichloro-5- and 6-carboxy-4,7-dichlorofluorescein, and 2′,4′,5′,7′-tetrachloro-5- and 6-carboxy-4,7-dichlorofluorescein; rhodamines such as tetramethylrhodamine and Texas Red®; benzimidazoles; ethidiums; propidiums; anthracyclines; mithramycins; acridines; actinomycins; merocyanines; coumarins such as 4-methyl-7-methoxycoumarin; pyrenes; chrysenes; stilbenes; anthracenes; naphthalenes such as dansyl, 5-dimethylamino-1-naphthalenesulfonyl; salicylic acids; benz-2-oxa-1-diazoles (also known as benzofurans), including 4-amino-7-nitrobenz-2-oxa-1,3-diazole; fluorescamine; and 4-methylumbelliferone.
[0054] R 2 is a phosphorus derivative that enables coupling to a free hydroxyl group. Preferred phosphorus derivatives are phosphoramidites, such that R 2 has the structure (III)
wherein X is NQ 1 Q 2 in which Q 1 and Q 2 may be the same or different and are typically selected from the group consisting of alkyl, aryl, aralkyl, alkaryl-cycloalkyl, alkenyl, cycloalkenyl, alkynyl, cycloalkynyl, optionally containing one or more nonhydrocarbyl linkages such as ether linkages, thioether linkages, oxo linkages, amine and imine linkages, and optionally substituted on one or more available carbon atoms with a nonhydrocarbyl substituent such as cyano, nitro, halo, or the like. Preferably, Q 1 and Q 2 represent lower alkyl, more preferably sterically hindered lower alkyls such as isopropyl, t-butyl, isobutyl, sec-butyl, neopentyl, tert-pentyl, isopentyl, sec-pentyl, and the like. Most preferably, Q 1 and Q 2 both represent isopropyl. Alternatively, Q 1 and Q 2 may be linked to form a mono- or polyheterocyclic ring having a total of from 1 to 3 usually 1 to 2 heteroatoms and from 1 to 3 rings. In such a case. Q 1 and Q 2 together with the nitrogen atom to which they are attached represent, for example, pyrrolidone, morpholino or piperidino. Usually, Q 1 and Q 2 have a total of from 2 to 12 carbon atoms. Examples of specific —NQ 1 Q 2 moieties thus include, but are not limited to, dimethylamine, diethylamine, diisopropylamine, dibutylamine, methylpropylamine, methylhexylamine, methylcyclopropylamine, ethylcyclohexylamine, methylbenzylamine, methylcyclohexylmethylamine, butylcyclohexylamine, morpholine, thiomorpholine, pyrrolidine, piperidine, 2,6-dimethylpiperidine, piperazine, and the like.
[0055] The moiety “Y” is hydrido or hydrocarbyl, typically alkyl, alkenyl, aryl, aralkyl, or cycloalkyl. Preferably, Y represents: lower alkyl; electron-withdrawing β-substituted aliphatic, particularly electron-withdrawing 1-substituted ethyl such as β-trihalomethyl ethyl, β-cyanoethyl, β-sulfoethyl, β-nitro-substituted ethyl, and the like; electron-withdrawing substituted phenyl, particularly halo-, sulfo-, cyano- or nitro-substituted phenyl; or electron-withdrawing substituted phenylethyl. Most preferably, Y represents methyl, β-cyanoethyl, or 4-nitrophenylethyl.
[0056] The coupling reaction is conducted tinder standard conditions used for the synthesis of oligonucleotides and conventionally employed with automated oligonucleotide synthesizers. Such methodology will be known to those skilled in the art and is described in the pertinent texts and literature, e.g., in D. M. Matteuci et al. (1980) Tet. Lett. 521:719 and U.S. Pat. No. 4,500,707. The product of the coupling reaction may be represented as structural formula (IV), as follows:
[0057] In the second step of the synthesis, the product (IV) is treated with an “alpha effect” nucleophile in order to remove the carbonate protecting group at the 5′ terminus, thus converting the moiety —OR 1 to —OH. The alpha effect nucleophile also oxidizes the newly formed phosphite triester linkage —O—P(OY)—O— to give the desired phosphotriester linkage
[0058] Advantageously, this step is conducted in an aqueous solution at neutral pH or at a mildly basic pH, depending on the pKa of the nucleophilic deprotection reagent. That is, and as will be explained in further detail below, the pH at which the deprotection reaction is conducted must be above the pKa of the deprotection reagent for the reagent to be effective. Typically, the reaction is conducted at a pH of less than about 10.
[0059] In a preferred embodiment, the nucleophilic deprotection reagent that exhibits an alpha effect is a peroxide or a mixture of peroxides, and the pH at which deprotection is conducted is at or above the pKa for formation of the corresponding peroxy anion. The peroxide may be either inorganic or organic. Suitable inorganic peroxides include those of the formula M + OOH − , where M is any counteranion, including for example H + , Li + , Na + , K + , Rb + , Cs + , or the like; and lithium peroxide or hydrogen peroxide can be particularly suitable. Suitable organic peroxides include those of the formula ROOH, where R is selected from the group consisting of alkyl, aryl, substituted alkyl and substituted aryl. More particularly, the organic peroxide will have one of the following three general structures (V), (VI) or (VII)
in which R 4 through R 10 are generally hydrocarbyl optionally substituted with one or more nonhydrocarbyl substituents and optionally containing one or more nonhydrocarbyl linkages. Generally, R 4 through R 10 are independently selected from the group consisting of hydrido, alkyl, aryl, aralkyl, cycloalkyl, cycloalkylalkyl, alkenyl, cycloalkenyl, alkynyl aralkynyl, cycloalkynyl, substituted aralkyl, substituted cycloalkyl, substituted cycloalkylalkyl, substituted alkenyl, substituted cycloalkenyl, substituted alkynyl substituted aralkynyl, substituted cycloalkynyl; t-butyl-hydroperoxide or metachloroperoxybenzoic acid can be particularly suitable. As a specific example, the m-chloroperbenzoic acid (mCPBA) peroxy anion exhibits a strong alpha effect towards the p-chlorophenylcarbonate electrophile, and that, accordingly, the peroxyanion of mCPBA is a particularly effective deprotection reagent for removal of p-chlorophenylcarbonate protecting groups.
[0060] The product of this simultaneous deprotection and oxidation step may thus be represented as follows:
wherein B, R and Y are as defined earlier herein. This latter reaction also gives rise to the by-products R 3 O − and carbon dioxide, insofar as nucleophilic attack of the peroxide deprotection reagent cleaves the carbonate linkage as follows:
[0061] The use of a peroxy anion to effect simultaneous removal of the carbonate protecting group and oxidation of the internucleotide linkage also removes, to a large extent, exocyclic amine-protecting groups such as acetyl, trifluoroacetyl, difluoroacetyl and trifluoroacetyl moieties. Thus, an added advantage herein is the elimination of a separate post-synthetic reaction step to remove exocyclic amine-protecting groups, as is required with conventional methods of synthesizing oligonucleotides. Elimination of this additional step significantly decreases the time and complexity involved in oligonucleotide synthesis.
[0062] An additional advantage of peroxy anions as deprotection reagents herein is that they may be readily activated or inactivated by simply changing pH. That is, the effectiveness of peroxides as nucleophiles is determined by their pKa. In buffered solutions having a pH below the pKa of a particular peroxide, the peroxides are not ionized and thus are non-nucleophilic. To activate a peroxide and render it useful as a deprotection reagent for use herein, the pH is increased above the pKa so that the peroxide is converted to a nucleophilic peroxy anion. Thus, one can carefully control the timing and extent of the deprotection reaction by varying the pH of the peroxide solution used.
[0063] FIG. 2 schematically illustrates 3′-to-5′ synthesis of an oligonucleotide using the method of the present invention. In the figure, the moiety “Arco” (“aryloxycarbonyl”) represents the carbonate protecting group p-chlorophenylcarbonyl. As may be seen, deprotection and oxidation occur simultaneously. The synthesis may be contrasted with that schematically illustrated in FIG. 1 , the prior, conventional method employing DMT protection and separate oxidation and deprotection steps. A further advantage of the invention is illustrated in FIG. 3 . As shown therein, in FIG. 3A , protection and deprotection of hydroxyl groups using DMT is a reversible process, with the DMT cation shown being a relatively stable species. Thus, using DMT as a protecting group can lead to poor yields and unwanted side reactions, insofar as the deprotection reaction is essentially reversible. FIG. 3B illustrates the irreversible deprotection reaction of the present invention, wherein nucleophilic attack of the peroxy anion irreversibly cleaves the carbonate moiety, i.e., the O-p-chlorophenylcarbonyl group, giving rise to carbon dioxide and the p-chlorophenol anion. The reaction is not “reversible,” insofar as there is no equilibrium reaction in which a cleaved protecting group could reattach to the hydroxyl moiety, as is the case with removal of DMT.
[0064] As explained earlier herein, the method of the invention also lends itself to synthesis in the 5′-to-3′ direction. In such a case, the initial step of the synthetic process involves attachment of a nucleoside monomer to a solid support at the 5′ position, leaving the 3′ position available for covalent binding of a subsequent monomer. In this embodiment, i.e., for 5′-to-3′ synthesis, a support-bound nucleoside monomer is provided having the structure (IX)
wherein ◯ represents the solid support or a support-bound oligonucleotide chain, R is hydrido or hydroxyl, and B is a purine or pyrimidine base. The protected monomer to be added has the structure of formula (X)
wherein the carbonate protecting group is present at the 3′ position, i.e. R 1 is COOR 3 where R 3 is as defined previously, and R 2 represents a phosphorus derivative that enables coupling to a free hydroxyl group, preferably a phosphoramidite having the structure (III)
wherein X and Y are as defined earlier herein. The coupling reaction in which the nucleoside monomer becomes covalently attached to the 3′ hydroxyl moiety of the support bound nucleoside is conducted under reaction conditions identical to those described for the 3′-to-5′ synthesis. This step of the synthesis gives rise to the intermediate (XI)
[0065] As described with respect to oligonucleotide synthesis in the 3′-to-5′ direction, the coupling reaction is followed by treatment of the product (XI) with an alpha effect nucleophile in order to remove the carbonate protecting group at the 3′ terminus, thus converting the moiety —OR 1 to —OH, and to oxidize the internucleotide phosphite triester linkage to give the desired phosphotriester linkage.
[0066] The two-step process of coupling and deprotection/oxidation is repeated until the oligonucleotide having the desired sequence and length is obtained. Following synthesis, the oligonucleotide may, if desired, be cleaved from the solid support.
[0067] The synthetic methods of the invention may be conducted on any solid substrate having a surface to which chemical entities may bind. Suitable solid supports are typically polymeric, and may have a variety of forms and compositions and derive from naturally occurring materials, naturally occurring materials that have been synthetically modified, or synthetic materials. Examples of suitable support materials include, but are not limited to, polysaccharides such as agarose (e.g., that available commercially as Sepharose®, from Pharmacia) and dextran (e.g. those available commercially under the tradenames Sephadex® and Sephacyl®, also from Pharmacia), polyacrylamides, polystyrenes, polyvinyl alcohols, copolymers of hydroxyethyl methacrylate and methyl methacrylate, silicas, teflons, glasses, and the like. The initial monomer of the oligonucleotide to be synthesized on the substrate surface is typically bound to a linking moiety which is in turn bound to a surface hydrophilic group, e.g., to a surface hydroxyl moiety present on a silica substrate.
[0068] Synthesis of Oligonucleotide Arrays:
[0069] In a related embodiment, the invention features a method for making an oligonucleotide array made up of array features each presenting a specified oligonucleotide sequence at an address on an array substrate. First, the array substrate is treated to protect the hydroxyl moieties on the derivatized surface from reaction with phosphoramidites or analogous phosphorus groups used in oligonucleotide synthesis. Protection involves conversion of free hydroxyl groups to —OR 1 groups, i.e., to carbonate-protected species. The method then involves (a) applying droplets of an alpha effect nucleophile to effect deprotection of hydroxyl moieties at selected addresses and oxidation of the newly formed internucleotide phosphite triester linkages, followed by (b) flooding the array substrate with a medium containing a selected nucleoside monomer having the structure of either Formula (II) (for 3′-to-5′ synthesis) or Formula (X) (for 5′-to-3′ synthesis). Step (a), deprotection/oxidation, and step (b), monomer addition, are repeated to sequentially build oligonucleotides having the desired sequences at selected addresses to complete the array features. In a variation on the aforementioned method, the applied droplets may comprise the selected nucleoside monomer, while the alpha effect nucleophile is used to flood the array substrate; that is, steps (a) and (b) are essentially reversed.
[0070] In the array construction method according to the invention, the deprotection reagents are aqueous, allowing for good droplet formation on a wide variety of array substrate surfaces. Moreover, because the selection of features employs aqueous media, small-scale discrete droplet application onto specified array addresses can be carried out by adaptation of techniques for reproducible fine droplet deposition from printing technologies.
[0071] Novel Compositions of Matter:
[0072] The invention additionally provides protected nucleoside monomers as novel compositions of matter useful, inter alia, in the synthesis of oligonucleotides as described herein. The novel monomers have the structural formulae (II) and (X)
wherein:
B is a purine or pyrimidine base, as described previously herein;
R is hydrido or hydroxyl;
R 1 is COOR 3 wherein R 3 is as described previously herein, such that the moiety OR 1 represents a carbonate-protected hydroxyl group; and
R 2 is a phosphorus derivative phosphorus derivative that enables coupling to a free hydroxyl group, and is preferably a phosphoramidite having the structure (III)
wherein X and Y are as defined earlier herein.
[0073] Reagent (II), used for 3′-to-5′ synthesis, is readily prepared by reaction of the unprotected nucleoside with the haloformate R 3 O—(CO)-Hal wherein Hal represents halo, typically chloro, and R 3 is as defined previously in the presence of a base effective to catalyze the nucleophilic reaction, e.g., pyridine. This step results in a 5′-carbonate, as follows:
[0074] The intermediate so prepared is then phosphitylated with the phosphoramidite PX 2 (OY) wherein X and Y are as defined earlier, resulting in conversion of the 3′-hydroxyl moiety to the desired substituent —O—PX(PY), i.e., —OR 2 :
[0075] A specific example of this synthesis is illustrated schematically in FIG. 4 , wherein “Arco” represents the aryloxycarbonyl group p-chlorophenylcarbonyl, iPr represents isopropyl, and B is either N 6 -benzoyl-protected deoxyadenine, N 4 -Fmoc-protected deoxycytidine, N 2 -isobutyryl-protected deoxyguanine or thymine. In the initial step of the reaction, the unprotected base is reacted with 4-chlorophenyl chloroformate in the presence of pyridine to give the carbonate-protected 5′-OH, followed by phosphitylation using (iPr 2 N) 2 PO(CH 2 ) 2 CN, i.e., β-cyanoethyl-N,N-diisopropylamino phosphoramidite.
[0076] Reagent (X), used for 5′-to-3′ synthesis, may be prepared by first synthesizing a 5′-protected nucleoside using a conventional 5′-OH protecting group such as DMT. This 5′-protected nucleoside is then reacted with the haloformate R 3 O—(CO)-Hal, which, as above, is done in the presence of a base effective to catalyze the nucleophilic reaction, e.g. pyridine. The DMT group is then removed with acid, resulting in the 3′-carbonate intermediate
[0077] Subsequent reaction with the phosphoramidite results in conversion of the 5′-hydroxyl moiety to the desired substituent —O—PX(PY), i.e., —OR 2 :
[0078] A specific example of this synthesis is illustrated schematically in FIG. 5 , wherein, as in FIG. 4 , “Arco” again represents the aryloxycarbonyl group p-chlorophenylcarbonyl, iPr represents isopropyl, and B is either N 6 -benzoyl-protected deoxyadenine. N 4 -Fmoc-protected deoxycytidine, N 2 -isobutyryl-protected deoxyguanine or thymine. In the initial step of the reaction shown in FIG. 4 , the 5′-O-DMT-protected base is reacted with 4-chlorophenyl chloroformate in the presence of pyridine to give the 3′ carbonate, followed by DMT removal using trichloroacetic acid and subsequent phosphitylation using β-cyanoethyl-N,N-diisopropylamino phosphoramidite.
[0079] It is to be understood that while the invention has been described in conjunction with the preferred specific embodiments thereof; that the description above as well as the example which follows are intended to illustrate and not limit the scope of the invention. Other aspects, advantages and modifications within the scope of the invention will be apparent to those skilled in the art to which the invention pertains.
EXPERIMENTAL
[0080] The practice of the present invention will employ, unless otherwise indicated, conventional techniques of synthetic organic chemistry, biochemistry, molecular biology, and the like, which are within the skill of the art. Such techniques are explained fully in the literature.
[0081] The following examples are put forth so as to provide those of ordinary skill in the art with a complete disclosure and description of how to prepare and use the compounds disclosed and claimed herein. Efforts have been made to ensure accuracy with respect to numbers (e.g., amounts, temperature, etc.) but some errors and deviations should be accounted for. Unless indicated otherwise, parts by weight, temperature is in ° C. and pressure is at or near atmospheric.
[0082] All patents, patent applications, journal articles and other references mentioned herein are incorporated by reference in their entireties.
Example 1
Protection and Deprotection of Deoxythymidine
[0083] (A) General Procedures:
[0084] Nuclear resonance spectra ( 1 H, 13 C and 31 P NMR) were recorded on a Varian VXR-300 spectrometer. Tetramethylsilane was used as an internal reference for 1 H and 13 C NMR. An external capillary containing 85% H 3 PO 4 was used as a reference for 31 P NMR. Downfield chemical shifts were recorded as positive values for 31 P NMR. Thin layer chromatography was performed on HF254 silica gel plates (Merck) in: CH 2 Cl 2 /MeOH, 9:1 (Solvent A), CH 2 Cl 2 /MeOH, 8:2 (Solvent B), ethyl acetate/THF/Et 3 N (45/45/10, v/v/v) (Solvent C). Pyridine, dichloromethane, and benzene were freshly distilled over CaH 2 . Acetonitrile was distilled over P 2 O 5 (solid), Followed by calcium hydride, and stored over molecular sieves. Hexanes and pentanes were distilled. 5′-O-(4,4′-6-Dimethoxytrityl)-6-N-((di-N-butylamino)methylene)-2′-deoxyadenosine and 2-N-(di-N-butylamino)methylene-2′-deoxyguanosine were prepared according to published procedures. Protected nucleoside-derived CPG was obtained from Applied Biosystems Inc.
[0085] (B) Synthesis of 5′-O-Nucleoside Carbonates:
[0086] The syntheses were conducted generally as follows. Deoxythymidine (2 mmol) was co-evaporated with anhydrous pyridine (2×20 ml), then redissolved in dry pyridine (40 ml). The corresponding chloroformate (2.2 mmol) was added and the mixture stirred at room temperature (25° C.) for 2 hr. The reaction was quenched with water (1 ml), then concentrated. The residual pyridine was removed by co-evaporation with toluene (40 ml).
[0087] The resulting residue was then dissolved in CHCl 3 (50 ml) and extracted with brine (40 ml). The aqueous layers were back-extracted with CHCl 3 (30 ml). The organic layers were combined, concentrated, and then loaded onto a silica gel column (100 g). The column was eluted with CH 2 Cl 2 using a methanol gradient. The isolated products were evaporated to foams.
[0088] This scheme was used to synthesize a series of alkyl and aryl 5′-O-carbonates of deoxythymidine from the corresponding chloroformates. In all cases, the best yields for the 5′-protected nucleoside were obtained when the reactions were performed at room temperature in pyridine excess of the chloroformate (1.1 eq). Under these conditions, good regioselectivity was observed with most chloroformates. Table 1 sets forth isolated yields of the 5′-protected nucleosides:
TABLE 1 ISOLATED YIELDS OF 5′-PROTECTED DEOXYTHYMIDINE WITH VARIOUS ALKYL AND ARYL CHLOROFORMATES AT ROOM TEMPERATURE IN PYRIDINE 5′-Carbonate Protected Thymidine Isolated Yield Cl 3 C(CH 3 ) 2 COCO 2 -dT (1a) 87% [5′-O-TCBOC-dT] [5′-O-Fmoc-dT] (1b) 90% 2-(NO 2 )C 6 H 4 OCO 2 -dT (1c) 35% [5′-O-oNPh-dT] C 6 H 5 N═NC 6 H 4 OCO 2 -dT (1d) 50% [5′-O-PAP-dT] C 6 H 5 OCO 2 -dT (1e) 60% [5′-O-Ph-dT] 4-(Cl)C 6 H 4 OCO 2 -dT (1f) 60% [5′-O-pClPh-dT]
[0089] The results were as follows.
5′-O-(2,2,2-Trichloro-1,1-Dimethylcarbonyl)Deoxythymidine (5′-O-TCBOC-dT, 1a)
[0090] Yield 87%. R F (A)=0.40, R F (B)=0.70. 1 H NMR (CDCl 3 +DMSO-D 6 ) δ: 7.33 (d, 1, H 6 ), 6.34 (t, J=7 Hz, 1, H 1′ ), 4.45-4.08 (m, 4, H 3′ , H 4′ , H 5.5′ ,) 2.32-2.1 (m, 2, H 2.2′ ), 1.94-1-93 (m, 6, C—(CH 3 ) 2 ), 1.88 (s, 3, C 5 —CH 3 ). 13 C NMR (CDCl 3 +DMSO-D 6 ) δ: 163.27 (C-4), 150.93 (0-(CO)—O), 149.68 (C-2) 134.21 (C-6), 109.71 (C-5), 104.37 C—Cl 3 ), 88.64 (C-Me 2 ), 83.39 (C-4′), 82.94 (C-1′), 62.96 (C-3′), 66.4 (C-5′), 20.02, 19.95 (C—(CH 3 ) 2 ), 11.6 (C 5 —CH 3 ).
5′-O-(9-Fluorenylmethylcarbonyl)Deoxythymidine (5′-O-Fmoc-dT, 1b)
[0091] Yield 90%. R F (A)=0.41, R F (B)=0.74. 1 H NMR (CDCl 3 +DMSO-D 6 ) δ: 7.72-7.28 (m, 9, Fmoc+H 6 ), 6.36 (t, J=7 Hz, 1, H 1′ ), 4.54-4.11 (m, 3, CHCH 2 (Fmoc), H 3′ , H 4′ , H 5.5′ ) 2.35-2.06 (m, 2, H 2.2′ ) 1.79 (s, 3, C 5 —CH 3 ), 13 C NMR (CDCl 3 +DMSO-D 6 ) δ: 163.87 (C-4), 154.58 (C-2), 150.28 (O—(CO)—O), 142.76, 142.71, 140.91, 127.04, 126.82, 124.59, 119.75 (Fmoc), 134.89 (C-6), 110.55 (C-5), 84.29 (C-4′), 83.76 (C-1′) 69.47 (C-3′), 66.92 (C-5′), 46.3 (Fmoc), 39.86 (C-2′), 12.13 (C 5 —CH 3 ).
5′-O-(p-Nitrophenylcarbonyl)Deoxythymidine (5′-O-oNPh-dT, 1c)
[0092] Yield 35%. R F (A)=0.41, R F (B)-0.68. 1 H NMR (CDCl 3 ) δ: 8.21 (d, 1, H 6 ), 7.89-7.53 (m, 4, aryl), 6.37 (t, J=7 Hz, 1, H 1′ ), 4.53-4.17 (m, 4, H 3′ , H 4′ , H 5.5′ ), 2.33-2.03 (m, 2, H 2.2′ ) 1.79 (s, 3, C 5 —CH 3 ). 13 C NMR (CDCl 3 ) δ: 164.3 (C-4), 153.04 (O—(CO)—O), 152.21 (C-2), 144.68, 142.1, 136.5, 128.36, 126.65, 125.68 (C 6 H 4 ), 136.33 (C-6), 111.05 (C-5), 85.44 (C-1′), 84.62 (C-4′), 71.54 (C-5′), 69.67 (C-3′), 40.15 (C-2′), 12.4 (C 5 —CH 3 ).
5′-O-(p-Phenylazophenylcarbonyl)Deoxythymidine (5′-O-PAP-dT, 1d)
[0093] Yield 50%. R F (A)=0.41, R F (B)=0.75. 1 H NMR (CDCl 3 ) δ: 7.94-7.28 (m, 10, H 6 6+aryl(PAP)), 6.31 (t, J=7 Hz, 1, H 1′ ), 4.5-4.12 (a, 4, H 3′ , H 4′ , H 5.5′ ), 2.33-2.19 (m, 2, H 2.2′ ), 1.86 (s, 3, C 5 —CH 3 ). 13 C NMR (CDCl 3 ) δ: 164.44 (C-4), 152.33 (O—(CO)—O), 152.1 (C-2), 152.86, 152.16, 150.55, 150.23, 131.05, 128.84, 123.86, 122.54, 121.21 (PAP), 135.56 (C-6), 110.92 (C-5), 84.65 (C-1′), 83.55 (C-4′), 70.13 (C-5′) 67-53 (C-3′), 39.73 (C-2′), 11.93 (C 5 —CH 3 ).
5′-O-(Phenylcarbonyl)Deoxythymidine (5′-O-PT-dT, 1e)
[0094] Yield 60%. R F (A)=0.41, R F (B)=0.71. 1 H NMR (CDCl 3 ) δ: 7.54-7.19 (m, 6, H 6 +aryl), 6.34 (t, J=7 Hz, 1, H 1′ ) 4.52-4.12 (m, 4, H 3′ , H 4′ , H 5.5′ ), 2.3-2 (a, 2, H 2.2′ ), 1.78 (s, 3, C 5 —CH 3 ). 13 C NMR (DMSOd- 6 +(CD3) 2 CO) δ: 164.36 (C-4), 152.21 (O—(CO)—O), 151.35 (C-2), 154.2, 130.42, 126.97, 121.99 (C 6 H 4 ), 136.61 (C-6), 111.11 (C-5), 85.44 (C-1′), 84.84 (C-4′), 71.73 (C-5′), 68.83 (C-3′), 40.21 (C-2′), 12.5 (C 5 —CH 3 ).
5′-O-(p-Chlorophenylcarbonyl)Deoxythymidine (5′-O-pClPh-dT, 1f)
[0095] Yield 60%. R F (A)=0.42, R F (B)=0.73. 1 H-NMR (CDCl 3 ) δ: 7.9 (d, 1, H 6 ), 7.44-7.16 (m, 5, aryl), 6.34 (t, J=7 Hz, 1, H 1′ ), 4.6-4.12 (m, 4, H 3′ , H 4′ , H 5.5′ ), 2.3-2.05 (m, 2, H 2.2′ ), 1.74 (s, 3, C 5 —CH 3 ), 13 C NMR (CDCl 3 ) δ: 164.4 (C-4), 153.23 (O—(CO)—O), 151.4 (C-2), 149.39, 139.86, 129.73, 122.23 (C 6 H 4 ), 136.6 (C-6), 111.1 (C-5), 85.41 (C-1′), 84.8 (C-4′), 71.52 (C-3′), 67.53 (C-5′), 40.25 (C-2′), 12.49 (C 5 CH 3 ).
[0096] (C) Synthesis of 5′-O-DMT-3′-O-R-deoxythymidines:
[0097] The 3′-hydroxyl group of 5′-O-DMT-deoxythymidine was protected with phenyloxycarbonyl (2a), benzoyl (2b), and acetyl (2c), as follows, 5′-O-(4,4′-Dimethoxytrityl)-deoxythymidine (1 mmol) was co-evaporated 3 times with anhydrous pyridine, then redissolved in 20 ml of pyridine. Corresponding, chloroformates (1.1 mmol) were added to the nucleoside mixture. After stirring for 6 hr, the reaction was quenched with water (100 ml) and concentrated. Residues of pyridine were removed by co-evaporation with toluene (2×20 ml).
[0098] The resulting gum was dissolved in CH 2 Cl 2 , extracted with 10% aqueous NaHCO 3 , and dried over Na 2 SO 4 . After concentration, the product was loaded onto a silica gel column (50 g) and eluted with CH 2 Cl 2 using a methanol gradient (0-3%). Product fractions were collected and concentrated to a foam.
[0099] The results were as follows.
5′-O-(4,4′-Dimethoxytrityl)-3′-O-Phenylcarbonyl Deoxythymidine (2a)
[0100] Yield 80%. R F (A)=0.74, R F (B)=0.91. 1 H NMR (CDCl 3 ) δ: 7.65-6.83 (m, 18, H 6 +DMTr+aryl), 6.57 (t, J=7 Hz, 1, H 1′ ), 5.45 (m, 1, H 3′ ) 4.34 (m, 1, H 4′ ), 3.79 (s, 6, OCH 3 ), 3.54 (m, 2, H 5.5′ ), 2.72-2.52 (m, 2, H 2.2′ ), 1.41 (s, 3, C 5 —CH 3 ).
5′-O-(4,4′-Dimethoxytrityl)-3′-O-Benzoyl Deoxythymidine (2b)
[0101] Yield 90%. R F (A)=0.72, R F (B)=0.91. 1 H NMR (CDCl 3 ) δ: 8.07-6.85 (m, 18, H 6 +DMTr+aryl), 6.58 (t, J=7 Hz, 1, H 1′ ), 5.45 (m, 1, H 3′ ), 4.14 (m, 1, H 4′ ), 3.79 (s, 6, OCH 3 ), 3.57 (m, 2, H 5.5′ ) 2.63 (m, 2, H 2.2′ ), 1.42 (s, 3, C 5 —CH 3 ).
5′-O-(4,4′-Dimethoxytrityl)-3′-O-Acetyl Deoxythymidine (2c)
[0102] Yield 90%. R F (A)=0.67, R F (B)=0.89. 1 NMR (CDCl 3 ) δ: 7.62 (s, 1, H 6 ), 7.4-6.82 (m, 13, DMTr), 6.46 (t, J=7 Hz, 1, H 1′ ), 5.45 (m, 1, H 3′ ), 4.14 (m, 1, H 4′ ), 3.78 (s, 6, OCH 3 ), 3.47 (m, 2, H 5.5′ ), 2.45 (m, 2, H 2.2′ ) 2.08 (s, 3, CO—CH 3 ), 1.39 (s, 3, C 5 —CH 3 ).
[0103] (D) Nucleoside Deprotection by Peroxy Anions:
[0104] Deprotection reactions were carried out using peroxy anions on alkyl and aryl 5′-O-carbonates of deoxythymidine synthesized as described above. The reactions were monitored by TLC for complete conversion of the starting material to deoxythymidine. A wide variety of peroxy anions, known to exhibit strong alpha effects, were screened for their ability to cleave 5′-O-carbonates of deoxythymidine. Peroxy anion solutions active in cleavage of the 5′-O-carbonates were buffered at a variety of pH conditions. The cleavage activity of these peroxy anion solutions was shown to be rapid only at pH conditions above the pKa for the formation of the anion. The ability of peroxy anion solutions A, B, C, D and E to completely deprotect the 5′-O-carbonates of deoxythymidines 1a-1f is summarized in Table 2.
[0105] Solution A: 3.1% LiOH.H 2 O (10 mL), 1.5 M 2-amino-2-methyl-1-propanol (“AMP”), pH 10.3 (15 mL), 1,4-dioxane (50 mL), 30% H 2 O 2 (12 mL) pH 12.0.
[0106] Solution B: 3.1% LiOH.H 2 O (10 mL), 1.5 M 2-amino-2-methyl-1-propanol (“AMP”), pH 10.3 (15 mL), dimethyl sulfoxide (“DMSO”) (50 ml), 30% H 2 O 2 (12 mL), pH 12.0.
[0107] Solution C: 3.1% LiOH.H 2 O (10 mL), 1.5 M 2-amino-2-methyl-1-propanol (“AMP”), pH 10.3 (15 mL), 1,4-dioxane (50 mL), 30% H 2 O 2 (12 mL), pH 12.0, m-chloroperbenzoic acid (“mCPBA”) (1.78 g), pH 9.6.
[0108] Solution D: H 2 O (10 mL), dioxane (50 mL), 2.5 M Tris (15 mL), H 2 O 2 (12 mL), mCPBA (1.78 g), pH 9.0.
[0109] Solution E: H 2 O (10 mL), dioxane (50 mL), 2.5 M Tris (15 mL), t-butyl-OOH (0.1 M), pH 9.0.
TABLE 2 TIMES REQUIRED FOR COMPLETE CONVERSION OF PROTECTED NUCLEOSIDES 1A THROUGH 1F USING PEROXY ANION SOLUTIONS A, B, C, D AND E -Carbonate- dT Reaction Completion Times for Deprotection Solutions Compounds A B C D E 1a <1 min <1 min <12 min — — 1b >1 hr <1 min >3 hr — — 1c <1 min <1 min <1 min — — 1d <1 min <1 min <1 min <1 min >12 hr 1e <1 min <1 min <1 min <2 min <12 hr 1f <1 min <1 min <1 min <1 min <12 hr
[0110] (E) Selectivity of Various Peroxy Anion Solutions for Deprotection of Carbonates
[0111] As described in part (C) of this example, the 3′-hydroxyl group of 5′-O-DMT-deoxythymidine was protected with a phenyloxycarbonyl (2a), a benzoyl (2b), and an acetyl (2c) group. The stability of these 3′-protecting groups was determined by TLC using deprotection conditions C and D (Table 2). Under both these conditions, the phenyl carbonate was completely removed in less than 2 min. The 3′-benzoyl group was completely stable under both conditions for 140 min. The 3′-acetyl group was cleaved to a small extent (less than 3%) over the 140 min exposure to deprotection condition A (pH 10.0). The 3-benzoyl group was completely stable for the 140 min exposure to condition B.
[0112] (F) Selectivity of Deprotection on Solid-Support Attached Nucleosides:
[0113] The demonstration of stability at the 3′ position was then extended to the succinate linker commonly used for the attachment of nucleosides to Controlled Pore Glass as follows. 5′-DMT-deoxythymidine attached to Long Chain Alkyl Amine Controlled Pore Glass (LCAA/CPG) through a 3′-succinate linkage was obtained from a commercial source. This solid-support attached nucleoside was then exposed to deprotection conditions A through D. The stability of the 3′-linkage was determined spectrophotometrically based upon the evolution of the trityl cation during subsequent treatment with toluene sulfonic acid in anhydrous acetonitrile. Deprotection conditions A and B gave complete cleavage of the 3′-succinate in 20 min. Deprotection conditions C and D gave less than 2% cleavage of the 3′-succinate after 20 hrs.
Example 2
Simultaneous Oligothymidylate Deprotection and Internucleotide Bond Oxidation by Peroxy Anions
[0114] Oligonucleotide Synthesis on Controlled Pore Glass:
[0115] Oligonucleotides were synthesized on CPG using an automated DNA synthesizer (ABI model 380A). The synthesis cycle used for 5′-DMT protected nucleoside phosphoramidites (Cycle 1) is shown in Table 4. This cycle was initially modified for the use of 5′-carbonate protected nucleoside phosphoramidites simply by substituting the alternative deprotection mixtures for the 3% TCA solution (Step 8, Table 4) and varying the exposure times. For the synthesis of longer sequences using 5-carbonate protected nucleoside phosphoramidites it was necessary to separate the deprotection mixture into a two-component system (Table 3). The separation of the deprotection mixture was accomplished using the capping ports on the synthesizer, and this necessitated elimination of the capping step from the synthesis cycle. Table 4 shows the optimized cycle for synthesis using 5′-carbonate protected nucleoside phosphoramidites (Cycle 2):
TABLE 3 TWO-COMPONENT SYSTEM FOR STORAGE OF DEPROTECTION SOLUTION C Solution 30% H 2 O 2 (10 ml), LiOH (280 mg), dioxane (7.5 ml), C-1 2.5 M Tris-Base (15 ml), water (42.5 ml) Solution 50-60% mCPBA (1.78 g), dioxane (42.5 ml) C-2
[0116]
TABLE 4
OLIGONUCLEOTIDE SYNTHESIS CYCLES
Cycle 1
Cycle 2
Step #
Function
Reagent
Time, sec.
Time, sec.
1
Wash
Acetonitrile
25
25
2
Coupling
Amidite (0.15 M, 30 eq) Tetrazole (0.5 M, 120 eq)
2 × 30
2 × 30
in Anhydrous Acetonitrile
3
Wash
Acetonitrile
5
5
4
Capping
N-Methylimidazole/2,6-Lutidine/Acetic
40
—
Anhydride/THF (1/1/1/2, vol/vol/vol/vol)
5
Oxidation
0.1 M I 2 in THF/Lutidine/Water (80/40/2, vol/vol/vol)
30
—
6
Wash
Acetonitrile
25
—
7
Wash
Dichloromethane (Cycle 1)
25
25
1,4-Dioxane (Cycle 2)
8
Deblock
3% TCA in CH 2 Cl 2 (Cycle 1)
2 × 30
480
1:1 mix of Solution C-1 & Solution C-2 from Table 3
(Cycle 2)
9
Wash
Dichloromethane (Cycle 1)
25
25
1,4-Dioxane (Cycle 2)
[0117] (B) Analysis of Oligonucleotides by HPLC:
[0118] The oligonucleotides synthesized on the solid support were deprotected with concentrated ammonium hydroxide (55° C. 24 hr). The ammonium hydroxide solutions were removed from the support and evaporated to dryness. The crude oligonucleotides were reconstituted in distilled water and stored at −20° C.
[0119] HPLC analysis was performed by ion-exchange HPLC (Nucleogen 60-7DEAE, 4 mm ID×125 mm). Oligonucleotides were eluted from the column with a LiCl gradient (0.0-0.7 M) in a water-acetonitrile (60/40, v/v) buffer containing sodium acetate (0.002 M, pH 6.0).
[0120] (C) Solid-Support Deprotection of 5′-O-carbonates of Thymidine:
[0121] The deprotection efficiency of peroxy-anion solutions on oligonucleotides was determined by the synthesis of oligothymidylate tetramers. The 5′-O-arylcarbonates of deoxythymidine (see part (B) of Example 1, compounds 1a through 1f) were converted to the corresponding 3′-O-(2-cyanoethyl)-N,N-diisopropylphosphoramidite by procedures described generally in A. D. Barone et al. (1984) Nucleic Acids Res. 12:4051, as follows.
[0122] Synthesis of the 2-cyanoethyl-N,N,N′,N′-tetraisopropyl-phosphorodiamidite phosphine was performed according the procedure described in A. Kraszewski et al. (1987) Nucleic Acids Res. 18:177. The resulting product was purified by distillation from CsF. The product was obtained in 60% yield. Purity was confirmed by 31 P NMR (CDCl 3 ) δ: 123.8 ppm.
[0123] Thymidyl-3′-5′-deoxythymidine was synthesized on solid-support using 5′-O-dimethoxytrityl-3′-O-(2-cyanoethyl)-N,N-diisopropylaminodeoxythymidinephosphoramidite. The dimer was elongated to a trimer using a 5′-O-aryloxycarbonyl-3-O-(2-cyanoethyl)-N,N-diisopropylaminodeoxythymidinephosphoramidite and synthesis cycle 1 (Table 4). Deprotection of the carbonate was then attempted using deprotection mixture C at 1 min increments, from 1-15 min. The extent of deprotection was determined by the yield of the subsequent coupling reaction using a standard 5′-DMT-dT phosphoramidite. Deprotection efficiency for the 5-O-arylcarbonate was determined using ion-exchange HPLC. The percent deprotection was calculated by integration and normalization of peak areas for the corresponding trimers and tetramers assuming quantitative coupling reactions. The optimum deprotection time and extent of deprotection for each aryloxycarbonyl Table 5.
TABLE 5 OPTIMUM DEPROTECTION TIMES DETERMINED FOR 5′-ARYLCARBONATES OF THYMIDINE ON CONTROLLED PORE GLASS USING DEPROTECTION SOLUTION C 5′-Carbonate dT Optimum Deprotection Deprotection Compounds Time Efficiency 1c 5 min 80% 1d 1 min 94% 1e 7 min 98% 1f 3 min| 98%
[0124] (D) Solid Support Synthesis and Internucleotide Bond Oxidation:
[0125] Several oligothymidylate tetramers were synthesized on Controlled Pore Glass using 5′-O-p-chlorophenyloxycarbonyl-3′-O-(2-cyanoethyl)-N,N-diisopropylaminodeoxythymidine-phosphoramidite. These syntheses were performed on a 1 μmol scale using an automated DNA synthesizer. The only modification from the standard 1 μmol synthesis cycle (Cycle 1, Table 4) was the use of deprotection mixture C (7 min) in place of 3% TCA in dichloromethane. The resulting tetramers were compared to oligothymidylate tetramers synthesized using the standard DMT protected phosphoramidites of thymidine. These tetramers were then analyzed using ion-exchange HPLC. There were no detectable differences in the yield or purity of any of the oligomers.
[0126] Oligothymidylate tetramers were then synthesized using this same synthesis cycle, which was again modified by the removal of the iodine oxidation step. This concomitant deprotection and oxidation cycle produced tetramers of identical yield and purity to the standard DMT phosphoramidite synthesis. Decomposition of MCPBA in the presence of LiOH results in the deprotection mixture being effective for only a few hours. In order to synthesize longer sequences, it was necessary to separate the deprotection mixture into a two component system (Table 3). This was accomplished using the capping ports on the automated DNA synthesizer. Separating the LiOH from the mCPBA and mixing just prior to deprotection allows the reagents to remain effective for several days. Oligonucleotide synthesis using, 5′-O-arylcarbonate nucleoside phosphoramidites was carried out with and without acetic anhydride capping. No adverse effects on the yield of final product or increases in the appearance of n−1 products were observed in absence of capping. This is contrary to what is seen with the use of DMT protected phosphoramidites in the absence of capping. Anion-exchange HPLC profiles of crude synthesis products of oligothymidylate decamers were produced. Product purity and yield of full-length oligonucleotides, using peroxyanion deprotection of 5′-O-carbonates in absence of acetic anhydride capping and iodine oxidation (Cycle 2, Table 4), were comparable to or better than those obtained using DMT phosphoramidites and the standard synthesis cycle.
Example 3
Peroxy Anion Deprotection of 5′-O-DMT-Protected Cytosine, Adenine, Uracil, Thymidine and Guanosine Nucleosides
[0127] The unprotected heterocyclic bases cytosine and adenine are susceptible to N-oxidation by peracids and peroxides under stringent conditions, and oxidative reactions that result in ring cleavage of uracil, thymidine and guanosine in the presence of highly concentrated peroxides at elevated temperatures have been described. 5′-O-DMT-protected nucleosides, N-protected with a (di-N-butylamino)methylene group, were dissolved in deprotection mixture C and allowed to react for 24 hrs. The tritylated nucleosides were extracted from the aqueous deprotection mixture with CHCl 3 and analyzed by 13 C NMR and TLC. Neither formation of N-oxides nor attack at the 5,6-double bond of thymidine (leading to ring cleavage) was detected.
Example 4
Synthesis of Mixed Oligonucleotides
[0128] This example demonstrates extension of the method of the invention to synthesis of mixed oligonucleotide sequences, employing substituted aryl carbonate protected phosphoramidite synthons, and following each coupling reaction by treatment with a mixture of peroxy-anions at mild pH (less than 10) to deprotect and concomitantly oxidize the internucleotide linkage.
[0129] The method is high-yielding, and effective for the four main 2′-deoxynucleotides. Synthesis in both the 3′-5′ direction and the 5′-3′ direction were carried out, with equal effect.
[0130] Protected Phosphoramidite Synthesis:
[0131] Generally, the protected nucleoside phosphoramidites were prepared as follows. The 3′- or 5′-protected nucleoside (5.00 mmol) and tetrazole (175 mg, 2.50 mmol) were dried under vacuum for 24 h and then dissolved in trichloromethane (100 mL). 2-cyanoethyl-N,N,N′,N′-tetraisopropyl phosphane (2.06 mL, 6.50 mmol) was added in one portion and the mixture stirred over 1 hour. The reaction mixture was washed with sat. NaHCO 3 (150 mL) and brine (150 mL), dried over MgSO 4 and applied directly to the top of a silica column equilibrated with hexanes. The dichloromethane was trashed off the column with hexanes, and the product eluted as a mixture of diastereoisomers using 1/1 hexanes/ethyl acetate then ethyl acetate. After evaporation of solvents in vacuo and coevaporation with dichloromethane, products were isolated as friable, white, glassy solids in yields varying from 70% to 90%.
[0132] The four 5′-aryloxycarbonyl-3′-nucleoside phosphoramidites were prepared by the straightforward two-step procedure shown generally in FIG. 4 . In a first step, commercially available base protected 2′-oligodeoxynucleosides were selectively aryl carbonate protected at the 5′ position by treatment with 4-chlorophenyl chloroformate in dilute anhydrous pyridine to yield 5′-aryloxycarbonyl protected compounds in moderate to good yield. The use of more concentrated reaction mixtures resulted in an increase in the amounts of isolated 3′- and 3′, 5′-bis-aryloxycarbonyl-protected materials. In a second step, the resulting compounds were phosphitylated using the method described in Barone et al., supra, to furnish high yields following column chromatography.
[0133] Synthesis of the four 3′-aryloxycarbonyl-5′-nucleoside phosphoramidites were prepared by the three-step procedure shown in FIG. 5 .
[0134] (C) Deprotection Mixture:
[0135] The deprotection mixture was formulated in two parts, which were mixed immediately prior to use. Solution F: 3.1% w/v lithium hydroxide monohydrate (10 mL), 1.5 M 2-amino-2-methyl-1-propanol pH 10.3 (15 mL). 1,4 dioxane (17.5 mL). Solution G: 1,4-dioxane (32.5 ml), 50-83% 3-chloroperbenzoic acid (1.78 g), 30% hydrogen peroxide (12 mL). The initial pH of the deprotection mixture was 9.6±0.05. For pH dependence studies, the initial deprotection mixture was altered by varying, the strength of the lithium hydroxide solution.
[0136] (D) Synthesis of Mixed-Sequence Oligonucleotides:
[0137] A series of model oligodeoxynucleotides was synthesized, having sequences 3′-T 3 AT 2 AT 3 -5′, 3′-T 3 CT 2 CT 3 -5′, 3′-T 3 GT 2 GT 3 -5′, 3′-TACGT-5′, 3TACGTACGT-5′, 3′-TA 7 T-5′, 5′-TACGT-3′, 5′-TACGTACGT-3′, and 5′-CAGTTGTAAACGAGTT-3′. HPLC analysis was performed as described in Example 2, part (B); HPLC traces of the all products confirmed the results.
[0138] The HPLC obtained for 5′-CAGTTGTAAACGAGTT-3′ is shown in FIG. 6 . The calculated molecular weight for 5′-CAGTTGTAAACGAGTT-3′ s 492.1; the actual molecular weight determine using MALDI (Matrix Absorption Laser Desorption Ionization) TOF (Time of Flight) analysis was 4921.9. The MALDI TOF spectrum is shown in FIG. 7 .
[0139] (E) Stability of Base Protecting Groups in the Deprotection Mixture:
[0140] The stability of the standard base protecting groups A Bz , C Bz , and G ibu during exposure to the deprotection mixture was tested by incubating 5-DMT base-protected deoxynucleosides at room temperature with a large excess of the deprotection mixture. The extent of cleavage of the base protecting groups over time was measured by TLC. The approximate T 1/2 values for A Bz , C Bz , and G ibu were approximately ½ hour, 2 hours, and 1 day, respectively, and unlikely to present difficulties for syntheses.
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The invention provides methods for synthesizing oligonucleotides using nucleoside monomers having carbonate protected hydroxyl groups that are deprotected with α-effect nucleophiles. The α-effect nucleophile irreversibly cleave the carbonate protecting groups while simultaneously oxidizing the internucleotide phosphite triester linkage to a phosphodiester linkage. The procedure may be carried out in aqueous solution at neutral to mildly basic pH. The method eliminates the need for separate deprotection and oxidation steps, and, since the use of acid to remove protecting groups is unnecessary, acid-induced depurination is avoided. Fluorescent or other readily detectable carbonate protecting groups can be used, enabling monitoring of individual reaction steps during oligonucleotide synthesis. The invention is particularly useful in the highly parallel, microscale synthesis of oligonucleotides.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method of producing p-type amorphous silicon carbide, and more particularly relates to a method for producing boron-doped p-type hydrogenated amorphous silicon carbide (hereinafter referred to as a-SiC:H), which is used as a window layer material for a p-i-n-type amorphous silicon solar cell.
2. Description of the Related Art
Use of a a-SiC:H thin film as a window layer material for a pin-type amorphous silicon solar cell has remarkably contributed to increasing the optoelectric conversion efficiency of the cell.
FIG. 2 illustrates an example of a structure of a conventional amorphous silicon solar cell. On a glass substrate 21, are laminated a tin oxide (SnO 2 ) thin film 22, a p-type a-SiC:H layer 23, an i-type hydrogenated amorphous silicon (hereinafter referred to a a-Si:H) layer 24, an n-type a-Si:H layer 25, and an aluminum electrode 26.
The tin oxide thin film 22 of such a conventional cell is formed by vacuum evaporation or thermal CVD, while the aluminum electrode 26 is formed by vacuum evaporation or sputtering. The a-Si:H layer is formed by plasma CVD in which a mono-silane gas (SiH 4 ) is decomposed by glow discharge at a substrate temperature of about 250° C.
In the formation of the n type a Si:H layer 25, phosphine gas (PH 3 ) is mixed with the mono-silane gas at a flow rate ratio of about 1% to the mono-silane gas. In the formation of the p-type a-SiC:H layer 23, methane gas (CH 4 ) and diborane gas (B 2 H 6 ) are mixed with the mono-silane gas.
When light 27 is made incident onto the glass substrate 21 of such an amorphous silicon solar cell as described above, a positive electric potential is generated in the p-side tin oxide electrode 22 and a negative electric potential is generated in the n-side aluminum electrode 26, respectively, by the photovoltaic effect in the p-i-n junction. FIG. 3 shows the current-voltage characteristics of the solar cell under sun light having intensity of 100 mW/cm 2 . This presented by Tawada et al. in the Journal of Applied Physics, Vol. 53 (1982), pp. 5273-5281. The black dot represents the point at which a product of the output current density and the output voltage, the output electric power per square centimeter of the amorphous silicon solar cell, becomes maximum. The output power at this point is generally called the output of the amorphous silicon solar cell, and the ratio of the output electric power to the incident light power is called the conversion efficiency.
In order to increase the output power of such an amorphous silicon solar cell, it is important that the light transmissivity of the p-type layer is high so that as much light as is possible can reach the i-type layer because only the i-type layer is photovoltaically active. Therefore, it is necessary to reduce the optical absorption coefficient of the p-type layer. The optical absorption coefficient α of the p-type layer is calculated from the following expression (1) in terms of its band gap Eg (unit:electron volt):
α=B.sup.2 (E-Eg).sup.2 /E (E<Eg) (1)
In the above expression (1), B 2 represents a constant, and E represents photon energy measured in electron volts. From the expression (1), it is understood that increasing Eg reduces the absorption coefficient u. In the journal mentioned above, Tawada et al. report that the conversion efficiency of an amorphous solar cell is improved from 5-6% to about 8% by forming the p-type layer with an a-SiC:H which has a wider band gap than an a-Si:H.
As described above, the transmissivity of the p-type layer increases with an increase in band gap. However, its electric conductivity under light irradiation (photoconductivity) decreases as the band gap increases. FIG. 4 shows the dependence of the photoconductivity of an a SiC:H film on its band gap, which dependence is plotted from the results reported in the foregoing journal article by Tawada et al. Such decrease in the photoconductivity will result in increasing the series resistance of the solar cell. Generally, the thickness of the p-type layer is about 10 -6 cm (10 nm) and its photoconductivity is 10 -6 S/cm. This value of photoconductivity is the minimum permissible because the value corresponds to a series resistance component of 1 Ω for an amorphous silicon solar cell having an area of 1 square centimeter and the series resistance larger than 1 Ω is not desirable for the cell. FIG. 4 suggests that the band gap must be under 2.0 electron volts in order to obtain a photoconductivity larger than 10 -6 S/cm. Consequently, it is difficult to provide a p-type window layer, .material for a p-i-n type amorphous silicon solar cell using an a-SiC:H film which has a band gap of 2.0 electron volts or more for improved light transmittivity as well as a photoconductivity of 10 -6 S/cm or more.
SUMMARY OF THE INVENTION
It is accordingly an object of the present invention to solve the foregoing problems associated with the related art and, specifically, to provide a method of producing a p-type a SiC:H thin film which has a higher photo conductivity as well as a larger band gap than a p-type a-SiC:H film produced by the conventional method, and which is capable of improving the conversion efficiency of an amorphous silicon solar cell as its window layer material.
Additional objects and advantages of the invention will be set forth in the description which follows.
To achieve the foregoing objects, and in accordance with the purposes of the invention as embodied and broadly described herein, a method of producing a p-type a-SiC:H film is provided comprising a step of preparing a raw material gas mixture composed of a silicon compound, a hydrocarbon or a fluorocarbon and a boron compound, the mixture being diluted with gas, and a step whereby such a raw material gas mixture is decomposed by glow discharge, wherein the flow rate of the hydrogen gas is selected to be 100 times or more than that of the silicon compound, and wherein a boron fluoride compound is used as the boron compound.
A boron fluoride series radical B m-x F n-y (m, n, x, and y being natural numbers, and x<m and y<n) produced by decomposition of a boron fluoride compound, having a formula of B m F n , by glow discharge, has lower reactivity with hydrogen than a boron hydride radical such as BH 3 or B 2 H 5 which are produced from diborane. Therefore, the boron fluoride radicals remove less hydrogen atoms covering the growing surface of an a SiC:H film. Consequently, the hydrogen atom density on the film growing surface is kept high by increasing the dilution ratio of the raw material gas with hydrogen to 100 times or more. As a result, the number of defects generated during growth of the a-SiC:H film is reduced, thereby improving the photoconductivity of the a-SiC:H film.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings illustrate the presently preferred embodiments and method of the invention. In the drawings:
FIG. 1 illustrates a cross section of a plasma CVD apparatus used in an example of the present invention;
FIG. 2 illustrates a cross section of a conventional amorphous solar cell using a p-type a-SiC:H film;
FIG. 3 illustrates a current-voltage characteristic of the solar cell of FIG. 2;
FIG. 4 illustrates the relationship between the photoconductivity and band gap of a p-type a SiC:H film; and
FIG. 5 illustrates the relationship between the photoconductivity of a p type a-SiC:H film and the dilution ratio of the raw material gas with hydrogen in deposition of the p-type a-SiC:H film.
DETAILED DESCRIPTION OF THE INVENTION
Reference will now be made in detail to the presently preferred embodiment and method of the invention as illustrated in the accompanying drawings.
FIG. 1 illustrates a plasma CVD apparatus to be used in an example of the present invention. In a vacuum chamber 1, having an internal volume of 10 liters, a lower circular electrode 31 for supporting a substrate 2 is mounted on a heating mount 4 opposite to an upper circular electrode 32. The area of each electrode 31 and 32 is 150 cm 2 . The upper electrode 32 is connected to a high frequency power source 51, and a heater 41, provided in the heating mount 4, is connected to a power source 52. A gas inlet pipe 6 and an outlet pipe 7 are opened to the vacuum cell 1, and the discharge pipe 7 is connected to a vacuum pump 8 through a control valve 81.
A example of the present invention using the above-mentioned apparatus is as follows.
As a raw material gas, mono-silane, methane, diboron tetrafluoride (B 2 F 4 ), and hydrogen were used. The flow rate of the mono-silane was 1.0 cc/min., the flow rate of the methane was 4.0 cc/min., the flow rate of the B 2 F 4 was 0.1 cc/min., and the flow rate of the hydrogen was 200 cc/min. so that the dilution ratio of the monosilane gas with hydrogen was 200. The raw material gas was fed into the evacuated cell through the gas inlet pipe 6. The rate of evacuation was adjusted by the control valve 81 so that the raw material gas pressure in the vacuum chamber 1 became 100 Pa. The heater 41 was then turned on so that the temperature of the glass substrate 2 became 250° C. Next, high frequency electric power of 2 watts and frequency of 13.56 MHz was applied by the high frequency power source 51 to the circular electrode 32 thereby generating glow discharge across the circular electrodes 31 and 32. As a result, the raw material gas decomposed forming a p-type a-SiC:H thin film on the glass substrate. The deposition rate of film formation was 0.1 Å/sec.
The band gap and photoconductivity of the deposited p-type a-SiC:H film were 2.1 electron volts and 10 - S/cm, respectively. It was also found that the photoconductivity of the p-type a-SiC:H film produced in this example was higher by about 2 orders of magnitude than the photoconductivity of a conventionally deposited film shown in FIG. 4.
FIG. 5 illustrate the photoconductivity of a p-type a-SiC:H film which was produced under conditions such the temperature of the glass substrate was fixed at 250° C., and the dilution of the mono-silane gas with hydrogen was varied. In this case, the dilution ratio of the raw material gas with hydrogen was varied in such a manner that the flow rates of mono-silane, methane, and boron trifluoride were fixed to respective constant rates of 1.0 cc/min., 4.0 cc/min., and 0.3 cc/min., and the flow rate of hydrogen was changed between a range of 25 cc/min. and 300 cc/min. As seen in FIG. 5, when the dilution ratio of mono-silane with hydrogen was less than 100, the photoconductivity increased as the hydrogen dilution ratio increased. When the dilution ratio of mono-silane with hydrogen was 100 or more, the photoconductivity hardly depended on the hydrogen dilution ratio. The band gap of the film also hardly depended on the hydrogen dilution ratio, and the value was 2.1 electron volts. From the foregoing results, it was found that, to make the photoconductivity of a p-type a-SiC:H film be 10 -5 S/cm or more, it is necessary to make the dilution ratio of the silicon compound, such as the mono-silane gas, or the like, with hydrogen, be 100 or more.
Although diboron tetrafluoride was used as the boron fluoride series compound in the foregoing example, the same effect as described above can be obtained even when a compound, such as boron trifluoride (BF 3 ), which generates a boron fluoride radical by glow discharge decomposition, is used in place of diboron tetrafluoride. Further, one can expect to obtain the same effect as described above when a compound in which a portion of fluoride in the foregoing boron fluoride compound is substituted with hydrogen or an organic radical such as a methyl radical, an ethyl radical, a vinyl radical, or the like.
As the silicon compound, di-silane tetrafluoride may be used in place of mono silane. In addition, a fluocarbon may be used in place of a hydrocarbon. Finally, as the hydrocarbon, ethane or acetylene may be used in place of methane, and as the fluocarbon, carbon tetrafluoride or methyl trifluoride can be used.
As described above, the dilution ratio of the silane series gas with hydrogen is selected to be 100 or more, and the boron fluoride series compound, having a bond between boron and fluorine, is used as the doping impurity source for formation of a p-type a-SiC:H film by the plasma CVD method. By this method, the photoconductivity of the p-type, a-SiC:H film can be increased to 10 -6 S/cm or more, even through the band gap of the film is increased to 2.1 electron volts or more in order to reduce the optical absorption coefficient as a window layer material. The resulting p-type a-SiC:H film thus has an unincreased series resistance value and a reduced optical absorption coefficient, which enables an amorphous silicon solar cell with excellent photoelectric conversion efficiency to be obtained.
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A method of producing a p-type hydrogenated amorphous silicon carbide thin film comprising the steps of preparing a raw material gas mixture consisting of a silicon compound, a hydrocarbon or a fluocarbon, and a boron compound, diluting the raw material gas mixture with hydrogen gas, and decomposing the raw material gas mixture by glow discharge to achieve a resultant film having a prescribed value of photoconductivity with a reduced optical absorption coefficient.
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BACKGROUND OF THE INVENTION
This invention relates to spray dispensing bottles, cans, plastic containers and the like for dispensing particulate solids suspended in a liquid medium as one may find among cosmetic formulations, deodorants and antiperspirants, fragrances, lacquers and paints, household products and pharmaceutical preparations. Products of this nature may be contained in a pressurized package, or one which utilizes a spray dispensing piston pump.
A problem in dispensing these suspensions utilizing a mechanical break-up feature in the valve tip and insert assembly of an aerosol or pump package, is the accumulation of solids in the swirl chamber which causes the package to cease dispensing by clogging the chambers. These tips, referred to as actuators, must be replaced or cleaned so that the contents of the package are once again deliverable for use. The replacement or cleaning of the actuator may have to be repeated several times during the use of the entire package contents owing to repeated clogging.
Therefore, there is a need for a self-cleaning or non-clogging mechanical break-up spray system to provide functional dispensing of suspended solids in a liquid, for the life of the package.
SUMMARY OF THE INVENTION
The invention is a novel valve or pump tip structure which prevents clogging of the mechanical break-up chamber to emit a fine spray of particulate suspensions in liquids. It is a solid body having
(a) a vertical axial passageway open at the bottom end for connection with the valve or pump stem which controls the flow from the vessel containing the product;
(b) a chamber formed in the surface of the solid body which enhances the production of a fine spray by turbulence, having
(i) a circular channel;
(ii) a central turbulence chamber which is concentric withinand coplanar with the circular channel; and
(iii) three or more symmetrically spaced channels connecting the circular channel and the turbulence chamber which are tangent to the turbulence chamber;
(c) a primary feed cylindrical conduit for bringing product from the axial passageway to the circular channel, which is perpendicular to the plane of the circular channel and turbulence chamber;
(d) a second smaller cylindrical conduit for directing a secondary flow into the center of the turbulence chamber from the axial passageway, which is perpendicular to the plane of the circular channel and turbulence chamber; and
(e) an orifice plate through which the product ultimately sprays from the actuator, also closing off the plane of the turbulence chamber so that the flow of product proceeds through the channels in proper sequence. The orifice in the plate is centered with respect to the turbulence chamber and secondary conduit from the axial passageway.
DESCRIPTION OF DRAWINGS
The invention will be more fully understood by reference to the drawings in which FIG. 1 is a perspective view of the actuator in position on a typical container.
FIG. 2 is a cross-sectional view of the actuator taken through a plane passing through the central vertical axis and the turbulence chamber of the invention.
FIG. 3 is a frontal view of the actuator from which the orifice plate insert has been removed to expose the turbulence chamber.
FIG. 4 is a frontal view of the turbulence chamber.
FIG. 5 is a perspective view of the orifice plate insert.
DETAILED DESCRIPTION OF THE INVENTION
This invention is applicable to pressure containers which dispense liquids containing particulate solids, e.g. solids less than 0.022 inches in size. Pressure can be supplied by a pressurizing medium such as blends of chlorofluorocarbons, hydrocarbons, carbon dioxide, or dimethyl ether, in which the user depresses the valve tip or actuator to release the pressurized product into the actuator. Instead of using a pressurized propellant, the same type of product movement may be produced from actuating a pump mounted in and sealed to the container. Depressing the actuator or tip moves a piston through a cylindrical tank which is inside the container. The workings of an aerosol valve and a pump are entirely conventional and well known to those who possess normal skill in packaging science. Use of pumps and pressurized containers are conventional to the packaging art.
Referring to the drawings, and particularly to FIGS. 1-2, in any of the embodiments described heretofore, the valve or pump tip 1, also known as an actuator, is attached to a valve or pump stem 2 by friction. The valve or pump stem is mounted and sealed to container 3. Stem 2 has a center bore, and serves to convey the product from the container to the actuator.
Reference is now made to FIG. 2. Actuator 1 is presented in cros-section to reveal an axial passageway 4 which receives at the bottom end, stem 2. The joining is a fluid-tight and pressure-tight connection. A primary feed conduit 5 connects the axial passageway to a circular channel 6, which is more clearly depicted in FIGS. 3-4. A secondary feed conduit 7 connects the axial passageway to the center of turbulence chamber 8. A cylindrical blind channel 9 receives the orifice insert 11, also shown in FIG. 5.
FIGS. 3-4, frontal views, show the circular channel 6, the turbulence chamber 8, and the ends of the feed conduits 5 and 7. Chamber 8 is concentric and coplanar with channel 6. From three to six (in these FIGS: 4) channels 10 direct the primary flow from the circular channel 6 tangentially into the turbulence chamber 8. By "tangentially" we mean not only tangential to the outer edge of turbulence chamber 8, but also into the interior of that chamber so long as it is not along a radius. These channels 10 are symmetrically positioned with respect to the chamber 8. The secondary feed conduit 7 terminates at the center of the turbulence chamber 8.
Located across the front of the actuator, and friction fitted into position is orifice plate face 13, shaped in the general contour of a cup, with a single center orifice 15. The leading edge 12 fits into the blind channel 9, pressed fitted until the inner surface of face 13 seals against the surfaces 14 and 16. Then product must pass from channel 6 into chamber 8 only by flowing through channels 10. Orifice 15 is located directly in the center of orifice insert face 13; therefore, it is also centered over turbulence chamber 8 and the end of secondary conduit 7.
Actuator 1 with passageways, conduits, chamber and channels can be molded readily from most thermoplastic resins, such as polyethylene, polypropylene, nylon, and equivalent materials. Orifice insert 11 could also be made of the same materials, but more conveniently is aluminum or another relatively corrosion resistant metal.
When the actuator is depressed which either forces or allows the product to be dispensed into the axial passageway 4, the stream divides into conduits 5 and 7. The diameter of the primary conduit 5 is about 45%-55% greater than the diameter of secondary conduit 7. Accordingly, about 21/4 as much product streams through conduit 5 as does through conduit 7. The liquid and suspended particulates flowing through conduit 5 continue into circular channel 6 and then through all the tangential channels 10 into the turbulence chamber 8, where the swirling and impinging streams cause a break-up of the liquid into a fine spray, emitting through orifice 15. In the turbulence chamber 8, there is a tendency for the solid particulates to deposit behind the orifice insert. The effluent stream of product jetting from conduit 7 continually discourages the deposition of particulates so that the turbulence chamber 8 remains free from solids and safe from clogging.
The ratio of the diameters of the primary conduit 5 to the secondary circuit 7 is 3:2, plus or minus 10%, and preferably 3:2. This ratio is critical to achieving a fine spray without clogging by particulates. The ratio of the diameters of the conduit 5 to the terminal orifice in the insert 15 is 2:1 plus or minus 10%, and is also critical in achieving a fine spray without clogging by particulates. The other functionally important ratio of diameters is the relationship between the terminal orifice 15 and turbulence chamber 8. This ratio can be 0.030 to 0.035, and preferably is 8:25, or 0.32, plus or minus 10%. Furthermore, the diameter of the primary conduit can be 90%-110% greater than that of the terminal orifice 15. The terminal orifice diameter should be in the range 0.012-0.022 inches, preferably about 0.017 inches. Accordingly, the following typical diameters would be functionally effective:
______________________________________Primary Conduit 5: .033 inchesSecondary Conduit 7: .022 inchesTerminal Orifice 15: .016 inchesTurbulence Chamber 8: .050 inches______________________________________
The description herein, and the Figures, illustrate the embodiment of the invention that will be most frequently employed, in which the circular channel and the turbulence chamber lie in a vertical plane so that product is sprayed in a generally horizontal direction. This invention can also be used to advantage where the chamber is in another plane so that product is sprayed at an angle off horizontal, provided that the relationships described herein are adhered to and the two conduits are perpendicular to the plane of the circular channel and turbulence chamber.
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An actuator for a container that dispenses liquids containing a suspension of particulate material that keeps itself from clogging comprises a mechanical break-up chamber to emit a fine spray and includes a continuous emission from an orifice which keeps the chamber free from accumulation of solid particles.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention generally relates to a semiconductor device fabrication method, and more particularly, to fabrication of a contact via plug after so-called borderless via etching during a fabrication process of a semiconductor device with multilevel interconnection.
[0003] 2. Description of the Related Art
[0004] Along with miniaturization of semiconductor devices, borderless via/wiring structures are often employed in multilevel interconnections used to improve the degree of integration. A borderless via/wiring structure has an upper-layer or lower-layer wiring pattern that does not completely cover the contact surface of the metal contact plug connecting the upper and lower wiring patterns. In other words, the upper-layer wiring pattern or the lower-layer wiring pattern is laterally displaced along the substrate surface and only partially overlaps the contact surface of the metal plug. See, for example, Japanese Laid-open Patent Publication No. 2003-218117A. It can be said that because of with miniaturization of device structures, a borderless structure is inevitably produced due to mask misalignment or exposure misalignment within the margin.
[0005] FIG. 1A through FIG. 1C illustrate a conventional process for fabricating multilevel interconnections with a borderless via/wiring structure. In FIG. 1A , a first metal wiring (M 1 ) 12 is located on a first interlevel dielectric layer (D 1 ) 11 over a semiconductor substrate (not shown). The first metal wiring 12 is covered with a second interlevel dielectric layer (D 2 ) 13 , and a second metal wiring (M 2 ) 16 is located over the second interlevel dielectric layer 13 . A contact metal plug (P) 15 surrounded by a barrier metal 14 connects the first metal wiring 11 with the second metal wiring 16 . The second metal wiring 16 does not completely cover, but partially overlaps the top surface of the metal plug 15 . This structure is called a borderless via/wiring structure. The metal plug 15 and the second metal wiring 16 are covered with a third interlevel dielectric layer 17 , and a resist mask (R) 18 defining a prescribed pattern is located over the third interlevel dielectric layer 17 .
[0006] Then, as illustrated in FIG. 1B , a contact hole 19 is formed in the third interlevel dielectric layer 17 by etching so as to reach the second metal wiring 16 . Because of the borderless via/wiring structure, the contact hole 19 further reaches the metal plug 15 with the second metal wiring 16 serving as a stopper. As a result, two different metals, e.g., aluminum (Al) of the second metal wiring 16 and tungsten (W) of the metal plug 15 , are exposed in the contact hole 19 .
[0007] After the contact hole 19 is formed, the resist mask 18 is removed by an ashing process. With the conventional method, plasma ashing is typically performed using oxygen O2 gas, or N2 added and/or CF4 added to oxygen gas, such as O2/N2 or O2/N2-H2/CF4. During the resist ashing, the top surface of the metal (tungsten) plug 15 revealed under the second metal wiring 16 is exposed to the ashing plasma in the contact hole 19 . Consequently, electric charge is accumulated on the surface of the tungsten plug 15 .
[0008] Then, the device is rinsed using an amine based solvent to remove the residual sediment, such as heavy metal materials, remaining after the ashing. This amine based wet process causes the charged surface of the tungsten plug 15 to be easily dissolved. As a result, a dissolved portion 20 (see FIG. 1C ) is produced in the tungsten plug 15 . Even after the contact hole 19 is filled with a metal material, the dissolved portion 20 remains as a void or a cavity, which prevents good electric contact between the upper and lower metal wirings 16 and 12 . This means that the device quality is degraded.
SUMMARY OF THE INVENTION
[0009] To overcome the above-described problem, the present invention provides a semiconductor device fabrication method that achieves reliable electric contact even with a borderless via/wiring structure, and that can improve the reliability of the operations.
[0010] To realize this, plasma irradiation using H2O gas or an H2O-containing gas (referred to as “H2O irradiation”) is performed prior to the wet rinsing process when removing the resist mask used to form the contact hole.
[0011] In one aspect of the invention, a method for fabricating a semiconductor device with a borderless via/wiring structure is provided. The method comprises the steps of:
(a) performing borderless via etching using a resist mask to form a contact hole in an interlevel dielectric layer over a semiconductor substrate so as to expose two different metal materials of lower layer patterns in the contact hole; and (b) performing plasma irradiation using an H2O-containing gas prior to a wet process when removing the resist mask.
[0014] In another aspect of the invention, a semiconductor device fabrication method comprises the steps of:
(a) forming a first contact plug connected to a lower-layer metal wiring over a semiconductor substrate; (b) forming an upper-layer metal wiring that overlaps the top face of the first contact plug; (c) depositing an interlevel dielectric layer over the first contact plug and the upper-layer metal wiring; (d) forming a contact hole in the interlevel dielectric layer so as to reach the overlapped portion to expose a part of the upper-layer metal wiring and a part of the first contact plug in the contact hole; (e) performing plasma irradiation using an H2O-containing gas; (f) removing a reaction product by a wet process using an amine based organic solvent; and (g) filling the contact hole with a metal material to form a second contact plug.
[0022] With these methods, electric charge accumulated on the plug surface exposed in the borderless via/wiring structure can be reduced by the H2O plasma irradiation performed prior to the wet process to remove the resist mask.
[0023] Consequently, dissolving of the metal plug can be prevented, and reliable electric contact can be guaranteed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Other objects, features, and advantages of the present invention will become more apparent from the following detailed description when read in conjunction with the accompanying drawings, in which:
[0025] FIG. 1A through FIG. 1C are schematic diagrams used to explain a problem in a conventional method for fabricating a metal plug by borderless via etching;
[0026] FIG. 2A through FIG. 2E illustrate in cross-sectional views a semiconductor device fabrication process according to an embodiment of the invention;
[0027] FIG. 3 is a flowchart of the borderless-via contact fabrication process according to an embodiment of the invention;
[0028] FIG. 4A and FIG. 4B illustrate detailed conditions of H2O-containing plasma irradiation;
[0029] FIG. 5 is a flowchart of a modification of the borderless via contact fabrication process;
[0030] FIG. 6 is a surface SEM image showing the tungsten dissolution preventing effect of H2O plasma irradiation according to the embodiment of the invention; and
[0031] FIG. 7 is a schematic diagram depicting the surface SEM image shown in FIG. 6 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0032] The preferred embodiments of the present invention are described below with reference to the attached drawings.
[0033] FIG. 2A through FIG. 2E illustrate a semiconductor device fabrication process according to an embodiment of the invention. First, as illustrated in FIG. 2A , TiN film 12 a, Al film (or Al—Cu film) 12 b, and TiN film 12 c are successively deposited on the first interlevel dielectric layer 11 formed over a semiconductor substrate (not shown), and patterned into a prescribed shape to define a first metal wiring (M 1 ) 12 . The first metal wiring 12 is electrically connected to an active or passive device (not shown) formed on the semiconductor substrate.
[0034] A second interlevel dielectric layer 13 is deposited over the first metal wiring 12 , and chemical mechanical polishing (CMP) is performed to obtain a flat surface. A contact hole (not shown) is formed in the second interlevel dielectric layer 13 so as to reach the first metal wiring metal 12 . The contact hole is coated with a barrier metal film 14 , and filled with a metal material, such as Tungsten (W), to form a first metal (W) plug 15 by a CMP or etch back process.
[0035] Then, a TiN film 16 a, an Al (or Al—Cu) film 16 b, and a TiN film 16 c are successively formed over the second interlevel dielectric layer 13 , and these films are patterned into a prescribed shape to define a second metal wiring (M 2 ) 16 . The second metal wiring 16 overlaps the first metal (W) plug 15 to cover only a part of the plug surface. This structure is a so-called borderless via/wiring structure. A third interlevel dielectric layer 17 is formed over the second metal wiring 16 and the second interlevel dielectric layer 13 , and the surface is flattened. A resist mask 18 with a prescribed aperture pattern is formed on the third interlevel dielectric layer 17 .
[0036] Then, as illustrated in FIG. 2B , a contact hole 19 is formed in the third interlevel dielectric layer 17 using the resist mask 18 so as to reach the second metal wiring (M 2 ) 16 and the first metal plug 15 located under the second metal wiring 16 . The second metal wiring 16 serves as a stopper film. By applying anisotropic etching to the third interlevel dielectric layer 17 , a contact hole 19 reaching the first metal plug 15 can be formed.
[0037] After the contact hole 19 is formed, at least a portion of the resist mask 18 is removed by an ordinary ashing process. During this ashing process (Ashing 1 ), electric charge is accumulated on the surface of the first metal plug 15 partially exposed in the contact hole 19 .
[0038] Then, as illustrated in FIG. 2C , plasma irradiation is performed using a gas containing H2O. This H2O plasma irradiation removes the residual resist mask 18 , and sufficiently removes the electric charge accumulated on the exposed surface of the tungsten plug 15 . The details of the H2O plasma irradiation are described below. After the H2O plasma irradiation, the wafer is rinsed in a wet process using an amine based organic solvent to remove reaction products. Because the electric charge is sufficiently removed from the surface of the first metal plug 15 , dissolution of tungsten can be prevented even in the wet process using the amine based organic solvent. After the wet process, a second ashing (Ashing 2 ) may be performed using an O2-containing gas as necessary.
[0039] Then, as illustrated in FIG. 2D , the contact hole 19 is coated with a barrier metal film 21 , and filled with a metal film, such as a tungsten film, to form a second metal plug 22 by a CMP or etch back process. The second metal plug 22 is connected to the second metal wiring (M 2 ) 16 and the first metal plug 15 . The positional relationship between the second metal plug 22 and the second metal wiring (M 2 ) is borderless.
[0040] Then, as illustrated in FIG. 2E , a third metal wiring (for example, a TiN/Al—Cu/TiN wiring) 23 is formed on the third interlevel dielectric layer 17 . Although not depicted in FIG. 2E , additional upper layer metal wiring and metal plug are formed as necessary to complete a semiconductor device with a borderless via/wiring structure indicated by the circle of the dashed broken line. This semiconductor device has an improved electric characteristic and satisfactory reliability with little damage due to dissolution of the lower layer metal plug 15 .
[0041] FIG. 3 is a flowchart of a part of the semiconductor device fabrication process, starting from via etching for forming the contact hole 19 through formation of the metal plug ( FIG. 2D ).
[0042] After the contact hole 19 is formed by photolithography and via etching (S 101 ), the wafer is placed in a downflow plasma asher to perform ordinary ashing (first ashing) without using H2O to remove the resist mask 18 used to form the contact hole 19 (S 102 ). The first ashing is performed for 90 seconds at 250° C. and power of 1100 W, by supplying O2 gas and N2 gas at rates of 3550 sccm and 140 sccm, respectively.
[0043] Then, the wafer is moved into a metal etcher ashing chamber to perform plasma irradiation using an H2O-containing gas (S 103 ). After the H2O irradiation, the wafer is rinsed using an amine-based organic solvent to remove reaction products (S 104 ). Then, second ashing is performed using an O2-containing gas (S 105 ). A barrier metal film 21 is formed in the contact hole 19 (S 106 ), and a metal film material is deposited so as to fill the contact hole 19 to form a contact plug 22 (S 107 ).
[0044] FIG. 4A and FIG. 4B are tables showing detailed conditions of the H2O plasma irradiation step S 103 shown in FIG. 3 . In the example shown in FIG. 4A , three sets of H2O irradiation are performed.
[0045] The first irradiation is performed for 40 seconds at 280° C. and power of 0 W under pressure of 2 Torr, while supplying H2O gas at 500 sccm.
[0046] The second irradiation is performed for 70 seconds at 280° C. and power of 1400 W under pressure of 2 Torr, supplying O2, H2O, and CF4 at 500 sccm, 100 sccm, and 50 sccm, respectively.
[0047] The third irradiation is performed for 40 seconds at 280° C. and power of 800 W under pressure of 2 Torr, while supplying H2O gas at 500 Sccm.
[0048] By performing H2O irradiation using H2O gas or an H2O-containing gas prior to the wet process, electric charge accumulated on the first metal plug 15 can be sufficiently reduced. The first and third H2O irradiations also have a corrosion preventing effect for preventing aluminum (Al) of the second metal wiring (M 2 ) 16 from corroding.
[0049] In the example shown in FIG. 4B , two sets of H2O irradiation are performed. The first irradiation is performed for 90 seconds at 275° C. and power of 1000 W under pressure of 1 Torr by supplying H2O at 900 sccm. The second irradiation is performed for 60 seconds at 275° C. and power of 1000 W under pressure of 1 Torr by supplying H2O and O2 at 900 sccm and 4500 sccm, respectively. The sequence of the first and second irradiations may be switched. Alternatively, only the second irradiation may be performed. In either case, an electric charge reducing effect can be sufficiently achieved.
[0050] FIG. 5 is a flowchart showing a modification of the fabrication process of a metal plug with a borderless via/wiring structure shown in FIG. 3 . After a contact hole 19 is formed by photolithography and via etching (S 201 ), a first ashing (Ashing 1 ) is performed making use of H2O plasma irradiation according to the embodiment (S 202 ) under the conditions shown in FIG. 4B . With this first ashing, the resist mask 18 can be removed, while preventing electric charge from accumulating on the exposed surface of the metal plug 15 . After the H2O irradiation, the wafer is rinsed in a wet process using an amine based organic solvent to remove reaction products (S 203 ). Then, a second ashing using an O2-containing gas is performed as necessary (S 204 ). Then, a barrier metal film 21 is formed in the contact hole 19 , and a metal film material is deposited so as to fill the contact hole 19 to form a metal plug 22 (S 206 ).
[0051] This method can also reduce the electric charge to be accumulated on the exposed surface of the first metal plug 15 during the formation of the second metal plug 22 connected to the second metal wiring (M 2 ) 16 and the lower metal plug 15 in a borderless positional relationship. Consequently, dissolving of the metal material of the contact plug 15 can be prevented in the subsequent wet process.
[0052] FIG. 6B is a surface SEM image showing the tungsten dissolution preventing effect achieved by the H2O irradiation according to the embodiment, and FIG. 7B is a schematic diagram illustrating the SEM image shown in FIG. 6B . As a comparison, FIG. 6A and FIG. 7A shows SEM observation results according to a conventional method (in which the contact hole is filled with a metal material after ordinary ashing without using H2O gas and the subsequent wet process).
[0053] In FIG. 6A and FIG. 6B , the overlapping amount of the second metal wiring (M 2 ) 16 with respect to the lower metal plug (P 1 ) 15 is varied, and the tungsten dissolving state is observed by a scanning electron microscope with the contact hole unfilled. The dark shadow observed in the round-shaped plug surface (P 1 ) 15 partially exposed under the U-shaped second metal wiring (M 2 ) 16 extending in the left-to-right direction is tungsten dissolved portion 20 . With the conventional method shown in FIG. 6A , tungsten dissolution is observed in the metal plug P 1 regardless of the overlapping amount between the metal plug P 1 and the second metal wiring M 2 , and the plug dissolution becomes especially conspicuous when the misalignment between the plug P 1 and the second metal wiring M 2 becomes large.
[0054] In contrast, when the wet process is performed after H2O irradiation after or during the ashing according to the embodiment, there is little dissolution of tungsten plug (P 1 ) observed in the surface SEM image, as illustrated in FIG. 6B . Even if the misalignment between the metal plug (P 1 ) and the second metal wiring (M 2 ) become the maximum, tungsten dissolution can be reduced to the minimum.
[0055] In this manner, satisfactory electrical contact can be maintained even if a borderless via/wiring structure is employed, and operational reliability of the semiconductor device is improved.
[0056] This patent application is based on and claims the benefit of the earlier filing dates of Japanese Patent Application No. 2005-308621 filed Oct. 24, 2005, the entire contents of which are incorporated herein by reference.
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A method for fabricating a semiconductor device with a borderless via/wiring structure includes the steps of performing borderless via etching using a resist mask to form a contact hole in an interlevel dielectric layer over a semiconductor substrate so as to expose two different metal materials of lower layer patterns in the contact hole; and performing plasma irradiation using an H2O-containing gas prior to a wet process when removing the resist mask.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2002-298500, filed Oct. 11, 2002, the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a semiconductor device having a capacitor and a method of manufacturing the same.
[0004] 2. Description of the Related Art
[0005] Research and development is conducted on nonvolatile memories (FeRAMs) using a ferroelectric film such as a PZT film (Pb(Zr,Ti)O 3 film) for a dielectric film of a capacitor.
[0006] A prior art method of manufacturing a ferroelectric memory will now be described with reference to FIGS. 3A to 3 D.
[0007] Referring first to FIG. 3A, a MIS transistor 12 , an interlayer insulation film 13 , a W plug 14 , a silicon nitride film 15 and a silicon oxide film 16 are formed on a semiconductor substrate 11 . A ferroelectric capacitor including a bottom electrode 21 , a ferroelectric film 22 and a top electrode 23 is formed on the silicon oxide film 16 . The bottom and top electrodes 21 and 23 are formed of a platinum (Pt) film, an iridium (Ir) film, an IrO 2 film or the like. The ferroelectric film 22 is formed of a PZT film or the like. An interlayer insulation film 24 is formed on the entire surface of the resultant structure and patterned to form a connecting hole 31 that reaches the top electrode 23 , a connecting hole 32 that reaches the bottom electrode 21 and a connecting hole 33 that reaches the W plug 14 .
[0008] Referring now to FIG. 3B, a barrier metal film such as TIN and an Al film are deposited in sequence. By performing processing such as CMP, a barrier metal film 34 a and an Al film 35 a are formed in the connecting hole 31 , a barrier metal film 34 b and an Al film 35 b are formed in the connecting hole 32 and a barrier metal film 34 c and an Al film 35 c are formed in the connecting hole 33 . The barrier metal films prevent the Al films from being alloyed with the films (Pt film, Ir film, etc.) used for the bottom and top electrodes 21 and 23 .
[0009] Referring now to FIG. 3C, a silicon oxide film 36 is deposited on the entire surface of the resultant structure and patterned to form trenches 37 and 38 . An Al film 39 a is formed in the trench 37 and an Al film 39 b is formed in the trench 38 , as shown in FIG. 3D.
[0010] In the above steps, a wiring including the Al films 35 a, 39 a and 35 c is connected to the top electrode 23 of the capacitor, and a wiring including the Al films 35 b and 39 b is connected to the bottom electrode 21 of the capacitor.
[0011] In the foregoing prior art manufacturing method, however, the barrier metal and Al films are formed in the connecting hole 33 as well as the connecting holes 31 and 32 . The connecting hole 33 is deeper than the connecting holes 31 and 32 and the diameter of the hole 33 is generally smaller than that of each of the holes 31 and 32 . If, therefore, the semiconductor device is microfabricated, the barrier metal and Al films become difficult to completely bury in the connecting hole 33 and thus a void or the like easily occurs in the Al film. Consequently, the wiring greatly deteriorates in characteristic and reliability.
[0012] Jpn. Pat. Appln. KOKAI Publication No. 2001-102538 proposes a technique of burying metal in a contact hole and a trench at once in a ferroelectric memory. If, however, a barrier metal film is used in the structure proposed in the Publication, the barrier metal film and metal film are difficult to completely bury in a deep contact hole (connecting hole), when a semiconductor device is microfabricated. For this reason, a wiring greatly deteriorates in characteristic and reliability.
[0013] According to the prior art ferroelectric memories described above, the barrier metal film and Al film are formed even in a connecting hole in a region that separates from the capacitor. Thus, the Al film becomes difficult to bury in the connecting hole and the wiring greatly deteriorates in characteristic and reliability.
BRIEF SUMMARY OF THE INVENTION
[0014] According to a first aspect of the present invention, there is provided a semiconductor device comprising: a semiconductor substrate; a capacitor provided above the semiconductor substrate and including a bottom electrode, a top electrode, and a dielectric film provided between the top electrode and the bottom electrode; an insulating region surrounding the capacitor and having a first hole which extends in a vertical direction and reaches the top electrode and a second hole which extends in the vertical direction and is spaced away from the capacitor; and a first wiring connected to the top electrode and including a first conductive portion formed in the first hole and a second conductive portion formed in the second hole, the first wiring having a barrier metal film between the insulating region and the first conductive portion and having no barrier metal film between the insulating region and the second conductive portion.
[0015] According to a second aspect of the present invention, there is provided a method of manufacturing a semiconductor device comprising: forming a capacitor above a semiconductor substrate, the capacitor being surrounded with an insulating region and including a bottom electrode, a top electrode and a dielectric film provided between the top electrode and the bottom electrode; and forming a first wiring connected to the top electrode, forming the first wiring including: removing part of the insulating region to form a first hole which extends in a vertical direction and reaches the top electrode; forming a barrier metal film in the first hole; forming a first conductive portion in the first hole in which the barrier metal film is formed; removing part of the insulating region to form a second hole which extends in the vertical direction and is spaced away from the capacitor; and forming a second conductive portion in the second hole without forming a barrier metal film in the second hole.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0016] [0016]FIGS. 1A to 1 D are sectional views schematically showing a method of manufacturing a semiconductor device according to a first embodiment of the present invention;
[0017] [0017]FIGS. 2A to 2 D are sectional views schematically showing a method of manufacturing a semiconductor device according to a second embodiment of the present invention; and
[0018] [0018]FIGS. 3A to 3 D are sectional views schematically showing a method of manufacturing a prior art semiconductor device.
DETAILED DESCRIPTION OF THE INVENTION
[0019] Embodiments of the present invention will now be described with reference to the accompanying drawings.
FIRST EMBODIMENT
[0020] [0020]FIGS. 1A to 1 D are sectional views schematically showing a method of manufacturing a semiconductor device (ferroelectric memory) according to a first embodiment of the present invention.
[0021] Referring first to FIG. 1A, a MIS transistor 12 is formed on a semiconductor substrate 11 such as a silicon substrate. An interlayer insulation film 13 such as a silicon oxide film (SiO 2 film) is formed on the entire surface of the resultant structure. A connecting hole is opened in the interlayer insulation film 13 to reach the source or drain of the MIS transistor 12 and filled with a W plug 14 . A silicon nitride film (SiN film) 15 and a silicon oxide film (SiO 2 film) 16 are formed on the entire surface of the resultant structure.
[0022] A ferroelectric capacitor is formed on the silicon oxide film 16 and includes a bottom electrode 21 , a ferroelectric film 22 formed on the bottom electrode 21 and a top electrode 23 formed on the ferroelectric film 22 . The bottom and top electrodes 21 and 23 are formed of a platinum (Pt) film, an iridium (Ir) film, an IrO 2 film or the like. The ferroelectric film 22 is formed of a PZT film (Pb(Zr,Ti)O 3 film) or the like.
[0023] An interlayer insulation film 24 such as a silicon oxide film is formed on a region including the capacitor. As a result, the capacitor is surrounded with an insulating region including the silicon oxide film 16 and interlayer insulation film 24 . The interlayer insulation film 24 is patterned by photolithography and RIE to form a connecting hole 51 that reaches the top electrode 23 and a connecting hole 52 that reaches the bottom electrode 21 .
[0024] Referring now to FIG. 1B, a barrier metal film and a metal film are deposited in sequence on the entire surface of the structure including the connecting holes 51 and 52 . The barrier metal film is formed of a TiN film, a NbN film, a TaN film, a TaAlN film or a stacked structure of these films. The metal film is formed of an Al film. An unnecessary portion is removed from the barrier metal film and metal film by CMP to leave the barrier metal film 53 a and metal film 54 a (conductive portion) in the connecting hole 51 and leave the barrier metal film 53 b and metal film 54 b (conductive portion) in the connecting hole 52 . In order to bury the metal films 54 a and 54 b in their respective connecting holes 51 and 52 by reflow of Al, a liner film is formed in advance on the barrier metal films 53 a and 53 b. The liner film differs from the barrier metal films 53 a and 53 b and is formed of, e.g., a Ti film or a Nb film.
[0025] Referring now to FIG. 1C, a silicon oxide film 55 is deposited as an insulating film on the entire surface of the resultant structure. The silicon oxide film 55 , interlayer insulation film 24 , silicon oxide film 16 and silicon nitride film 15 are patterned by photolithography and RIE. Thus, a connecting hole 56 that reaches the W plug 14 is formed and so are trenches 57 and 58 .
[0026] Referring now to FIG. 1D, an Al film is formed as a metal film on the entire surface of the resultant structure. An unnecessary portion is removed from the metal film by CMP. Thus, a conductive portion of a metal film 59 is formed in the connecting hole 56 , a conductive portion of a metal film 60 a is formed in the trench 57 and a conductive portion of a metal film 60 b is formed in the trench 58 . To form the metal films 59 , 60 a and 60 b by reflow of Al, a liner film is formed in advance. The liner film differs from the barrier metal films 53 a and 53 b and is formed of, e.g., a Ti film or a Nb film.
[0027] The top electrode 23 of the capacitor and the W plug 14 connected to the source or drain of the MIS transistor 12 are connected to each other through a wiring including the conductive portion 54 a extending in the vertical direction, the conductive portion 60 a extending in the horizontal direction, and the conductive portion 59 extending in the vertical direction. The bottom electrode 21 of the capacitor is connected to a wiring including the conductive portion 54 b extending in the vertical direction and the conductive portion 60 b extending in the horizontal direction.
[0028] According to the first embodiment described above, the connecting holes 51 and 52 are formed to reach the bottom and top electrodes 21 and 23 , then the barrier metal film and metal film (Al film) are formed in the connecting holes 51 and 52 , and then the connecting hole 56 is formed to reach the W plug 14 . Accordingly, no barrier metal film is formed in the connecting hole 56 . The barrier metal film prevents the metal film (Al film, etc.) serving as a wiring film from being alloyed with the metal films (Pt film, Ir film, etc.) used for the bottom and top electrodes 21 and 23 . No problems therefore occur even though no barrier metal film is formed in the connecting hole 56 . According to the first embodiment, therefore, the metal film serving as a wiring film and the metal films used for the bottom and top electrodes can be prevented from being alloyed with each other, and the metal film can reliably and easily be buried into the connecting hole that separates from the capacitor. Consequently, even though the semiconductor device is microfabricated, the wiring can be improved in characteristic and reliability.
SECOND EMBODIMENT
[0029] [0029]FIGS. 2A to 2 D are sectional views schematically showing a method of manufacturing a semiconductor device (ferroelectric memory) according to a second embodiment of the present invention. The components corresponding to those shown in FIGS. 1A to 1 D are indicated by the same reference numerals and their detailed descriptions are omitted.
[0030] The fundamental step shown in FIG. 2A is the same as that shown in FIG. 1A. More specifically, a ferroelectric capacitor including a bottom electrode 21 , a ferroelectric film 22 and a top electrode 23 is formed and then an interlayer insulation film 24 is formed to cover the ferroelectric capacitor. The interlayer insulation film 24 is patterned by photolithography and RIE to form a connecting hole 71 that reaches the top electrode 23 and a connecting hole 72 that reaches the bottom electrode 21 .
[0031] Referring now to FIG. 2B, a barrier metal film is deposited on the entire surface of the structure including the connecting holes 71 and 72 . The barrier metal film is formed of a TiN film, a NbN film, a TaN film, a TaAlN film or a stacked structure of these films. An unnecessary portion is removed from the barrier metal film by CMP to leave the barrier metal 73 a along the inner surface of the connecting hole 71 and leave a barrier metal film 73 b along the inner surface of the connecting hole 72 .
[0032] Referring now to FIG. 2C, the interlayer insulation film 24 , silicon oxide film 16 and silicon nitride film 15 are patterned by photolithography and RIE to form a connecting hole that reaches a W plug 14 . A metal film (Al film) is deposited on the entire surface of the resultant structure. An unnecessary portion is removed from the metal film by CMP to leave metal films 74 a, 74 b and 74 c as conductive portions in the connecting holes 71 and 72 and the connecting hole that reaches the W plug 14 , respectively. In order to form the metal films 74 a, 74 b and 74 c in the connecting holes by reflow of Al, the same liner film as that in the first embodiment is formed in advance.
[0033] Referring now to FIG. 2D, a silicon oxide film 75 is deposited on the entire surface of the resultant structure as an insulating film. The silicon oxide film 75 is patterned by photolithography and RIE to form a trench that reaches the metal films 74 a and 74 c and a trench that reaches the metal film 74 b. After that, an Al film is formed on the entire surface of the resultant structure as a metal film. An unnecessary portion is removed from the metal film by CMP to form a conductive portion of a metal film 76 a and a conductive portion of a metal film 76 b in their respective trenches. In order to form the metal films 76 a and 76 b by reflow of aluminum, the same liner film as that in the first embodiment is formed in advance.
[0034] The top electrode 23 of the capacitor and the W plug 14 connected to the source or drain of the MIS transistor 12 are connected to each other through a wiring including the conductive portion 74 a extending in the vertical direction, the conductive portion 76 a extending in the horizontal direction and the conductive portion 74 c extending in the vertical direction. The bottom electrode 21 of the capacitor is connected to a wiring including the conductive portion 74 b extending in the vertical direction and the conductive portion 76 b extending in the horizontal direction.
[0035] In the second embodiment described above, too, no barrier metal film is formed in the connecting hole that reaches the W plug 14 . Accordingly, as in the first embodiment, the metal film serving as a wiring film is prevented from being alloyed with the metal films used for the bottom and top electrodes, and the metal film can reliably and easily be buried into the connecting hole that separates from the capacitor. Consequently, even though the semiconductor device is microfabricated, the wiring can be improved in characteristic and reliability.
[0036] In the foregoing second embodiment, the metal films 74 a, 74 b and 74 c are formed in the connecting holes in the same step. However, these metal films can be formed as follows: First, the barrier metal films 73 a and 73 b are formed in the step shown in FIG. 2B and then the metal films 74 a and 74 b are formed. After that, a connecting hole that reaches the W plug 14 is formed and the metal film 74 c is formed in the connecting hole.
[0037] In the foregoing second embodiment, the metal films 76 a and 76 b are buried in the trenches formed in the silicon oxide film 75 in the step shown in FIG. 2D. However, after the step shown in FIG. 2C, a metal film can be formed in the entire surface of the structure and then patterned by RIE or the like to form the metal films 76 a and 76 b.
[0038] In the foregoing first and second embodiments, a conductive portion connected to the bottom electrode 21 is provided on the upper side of the bottom electrode. However, the conductive portion can be provided on the lower side of the bottom electrode (a so-called COP structure).
[0039] In the foregoing first and second embodiments, a conductive portion (conductive portion 59 in FIGS. 1A to 1 D and conductive portion 74 c in FIGS. 2A to 2 D) is connected to the source or drain of the MIS transistor 12 through the W plug 14 . However, the conductive portion can be connected to the source or drain without providing the W plug 14 .
[0040] In the foregoing first and second embodiments, the Al film is used as a metal film to be formed in the connecting hole or the trench. However, the Al film can be replaced with a Cu film or a W film.
[0041] 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 representative 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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Disclosed is a semiconductor device comprising a semiconductor substrate, a capacitor provided above the semiconductor substrate and including a bottom electrode, a top electrode, and a dielectric film provided between the top electrode and the bottom electrode, an insulating region surrounding the capacitor and having a first hole which extends in a vertical direction and reaches the top electrode and a second hole which extends in the vertical direction and is spaced away from the capacitor, and a first wiring connected to the top electrode and including a first conductive portion formed in the first hole and a second conductive portion formed in the second hole, the first wiring having a barrier metal film between the insulating region and the first conductive portion and having no barrier metal film between the insulating region and the second conductive portion.
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FIELD OF THE INVENTION
[0001] The present invention relates generally to methods having the purpose of disabling the progress of a vehicle, and in particular methods to apparatuses for preventing high speed vehicle pursuits and vehicle theft.
BACKGROUND OF INVENTION
[0002] In the area of law enforcement, police and other law enforcement officers are commonly required to stop and question motorists. Frequently, these traffics stops occur on the side of the road. During a traffic stop, there is a possibility that a motorist may attempt to flee causing the officer to pursue the fleeing vehicle at high speeds. Such incidents cause injuries to law enforcement officers and damage to law enforcement vehicles due to collisions caused by high speed chases. Additionally, the fleeing vehicle may harm individuals and property not involved in the traffic stop. Law enforcement agencies may be required to bear the costs of workers' compensation claims, personal injury and other lawsuits against the law enforcement agency, and insurance claims resulting from vehicle damage. Therefore, a means for deterring a detained motorist from fleeing the scene is desired. One such means possesses a mechanism for deflating vehicle tires of a fleeing motorist in order to prevent the motorist from achieving high speeds and prevent injury and or death to innocent bystanders.
[0003] The utility patents U.S. Pat. No. 5,482,397 and U.S. Pat. No. 5,704,445 issued to Soleau and Jones respectively, disclose a tire deflator including a spike secured to a support mechanism such that upon contact with a tire of a moving vehicle the spike penetrates the tire causing rapid air depletion. However, Soleau and Jones lack a means for positioning the apparatus on either side of the tire. Additionally, Soleau and Jones require the user to position the chocks underneath the vehicle wheel by hand, causing law enforcement officers to be vulnerable to injury if the vehicle moves. Therefore, an apparatus is needed that is easily positioned on a vehicle tire without exposing a user's body to possible harm.
[0004] The Soleau and Jones patents also fail to include a mechanism for protecting users from the disclosed spikes during placement and while the apparatuses are not in use. Therefore, an apparatus is needed that protects individuals from injury caused by inadvertent contact with deflating spikes.
[0005] The utility patent U.S. Pat. No. 5,689,981 issued to DeLuca et al. discloses an anti-theft vehicle wheel lock wherein a chock is positioned against a vehicle tire coupled with a bar on the opposing side securing the chock in place. Furthermore, a lock prevents movement of the chock and opposing bar, and a handle extends upward facilitating placement of the device. However, DeLuca et al. only is effective when locked into place, which takes time, and has no effect to prevent a high speed chase such as deflating vehicle tires. Therefore, an apparatus is needed that is easily placed and may be used in an unlocked position in order to prevent a vehicle from achieving high speeds.
[0006] For these reasons, in order to prevent high-speed pursuits, a method for utilizing a deflating apparatus is that is easily placed, without exposing a user's body to harm is needed.
SUMMARY OF THE INVENTION
[0007] The apparatus of the present invention, a method for utilizing an apparatus for preventing high speed vehicle pursuits and vehicle theft, includes spikes, or other means for deflating a vehicle tire known in the art, disposed on opposing blocks or chocks, further secured to adjustable supports. A vertical user engageable member is secured to the support facilitating placement around a vehicle tire. The instant method is applicable to all types of vehicles, including but not limited to automobiles, motorcycles and airplanes.
[0008] The apparatus has two positions, stored and deployed. While the apparatus is in the stored position, the supports are folded upward toward the vertical user engageable member. The spikes are pointed downwards or horizontally towards the opposing block causing the blocks to cover the spikes and protect individuals from unintentional contact and resulting injury. In order to deploy the device, the supports are propelled downward by a spring force, or other deploying mechanism known in the art, when activated by a user.
[0009] Once deployed, the apparatus is locked into position. A user places the apparatus around a vehicle tire using the vertical user engageable member allowing placement without exposing a user's body to harm or the need for locking the apparatus around the tire. The blocks are positioned along side the outside front and back surfaces of the vehicle tire. The spikes and opposing blocks are positioned so to compress against the lower front and lower back surfaces of a vehicle tire. Foam or cushioning may be placed over the spikes in order to further protect users from exposed spikes. Due to the durability of a vehicle tire, the spikes will not penetrate causing deflation unless a strong force is applied on the spikes, such as vehicle propelled movement.
[0010] Thus, if the vehicle is moved in either direction, the spikes, or other deflating means, puncture the tire, thus releasing the air in the tire well before the vehicle gains any significant forward or reverse motion while at the same time not rendering the vehicle out-of-control from the operator. Thus, escape at high speeds is prevented. The spikes are capable of piercing any sized vehicle tire; regardless of the speed or direction the vehicle attempts to flee.
[0011] These and other features, aspects and advantages of the present invention will become better understood with reference to the following description, claims, and accompanying drawings. Therefore, the form of the invention, as set out above, should be considered illustrative and not as limiting the scope of the following claims.
BRIEF DESCRIPTION OF DRAWINGS
[0012] FIG. 1 is a front prospective view of an embodiment of the apparatus for preventing high speed vehicle pursuits and vehicle theft in deployed position;
[0013] FIG. 2 is a side view of an embodiment of the apparatus for preventing high speed vehicle pursuits and vehicle theft placed around a vehicle tire in deployed position;
[0014] FIG. 3 is a rear view of an embodiment of the apparatus for preventing high speed vehicle pursuits and vehicle theft placed around a vehicle tire in deployed position;
[0015] FIG. 4 is a top view of an embodiment of the apparatus for preventing high speed vehicle pursuits and vehicle theft; and
[0016] FIG. 5 is a front view of an embodiment of the apparatus for preventing high speed vehicle pursuits and vehicle theft in stored position.
DESCRIPTION OF THE INVENTION
[0017] The preferred embodiment of the present invention represents an apparatus for preventing high speed vehicle and vehicle theft pursuits as shown in FIGS. 1-5 . The apparatus 1 of the present invention includes spikes 2 , or other means for deflating a vehicle tire known in the art, disposed on blocks 3 , 4 . The blocks 3 , 4 are secured to supports 5 , 6 . A user places the apparatus 1 using a vertical user engageable member 7 allowing placement without exposing a user's body to harm. The spikes 2 and opposing blocks 3 , 4 are positioned so to compress against the lower front and lower back surfaces of a vehicle tire. The spikes 2 may be hollow spikes, blades or other deflating means, and foam or cushioning may be placed over the spikes 2 . The apparatus 1 is comprised of steel or other high strength material with similar properties.
[0018] The apparatus has two positions, stored as shown in FIG. 5 and deployed as shown in FIGS. 1-4 . While the apparatus 1 is in stored position, the supports 5 , 6 are folded upward toward the vertical user engageable member 7 and fastened as shown in FIG. 5 . The spikes 2 are pointed downwards or horizontally towards the opposing block 3 , 4 causing the blocks 3 , 4 to cover the spikes 2 and protect unintentional contact and resulting injury. In order to deploy the apparatus 1 , the supports 5 , 6 are propelled downward, due to a spring force or other deploying mechanism known in the art, when activated by a user.
[0019] Once deployed, the apparatus 1 is locked in deployed position as shown in FIGS. 1-4 . A user places the apparatus 1 around a vehicle tire using the vertical user engageable member 7 allowing placement without exposing any part of the body in front of or behind a vehicle tire, thus, susceptible to crushing were the vehicle to move. The blocks 3 , 4 are positioned along side the outside front and back surfaces of the vehicle tire. The spikes 2 and opposing blocks 3 , 4 are positioned so to compress against the lower front and lower back surfaces of a vehicle tire.
[0020] While the apparatus 1 is in place, if the vehicle begins to move, the spikes 2 , or other deflating means, puncture the tire, thus releasing the air in the tire well before the vehicle gains any significant forward or reverse motion while at the same time not rendering the vehicle out-of-control. The apparatus can be modified such that the spikes 2 are capable of piercing any sized vehicle tire; regardless of the speed or direction the vehicle attempts to flee.
[0021] Shown here is a method for preventing high speed vehicle pursuits, comprising extending the apparatus for preventing high speed vehicle pursuits utilizing a deploying mechanism prior to positioning the apparatus for preventing high speed vehicle pursuits. The method may further include placing the apparatus for preventing high speed vehicle pursuits around a vehicle tire of a stopped vehicle. Additionally, the method may include removing the apparatus and raising the apparatus into a closed position after removing the apparatus for preventing high speed vehicle pursuits.
[0022] Further shown is a method for preventing vehicle theft, comprising extending an apparatus for preventing vehicle theft by utilizing a deploying mechanism prior to positioning the apparatus for vehicle theft. The method may further include placing the apparatus for preventing vehicle theft around a vehicle tire of a stopped vehicle and may also include removing the apparatus for preventing vehicle theft. The method may further include raising the apparatus for preventing high speed vehicle pursuits into a closed position after removing.
[0023] Further shown is a method for preventing vehicle theft, comprising extending an apparatus for preventing vehicle theft by the deploying mechanism prior to placing the apparatus for preventing vehicle theft placing the apparatus for preventing high speed vehicle pursuits and vehicle theft around the vehicle tire of a stopped vehicle. The method may further include locking the apparatus for preventing high speed vehicle pursuits and vehicle theft by the locking mechanism in position around the vehicle tire and removing the apparatus for preventing vehicle theft. The method may additionally include raising the apparatus for preventing high speed vehicle pursuits into a closed position after removing the apparatus for preventing high speed vehicle pursuits.
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A method for preventing high speed vehicle pursuits and vehicle theft comprising utilization of a removable restraining apparatus to temporarily immobilize a vehicle.
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This is a continuation of application Ser. No. 736,536, filed Oct. 28, 1976, now abandoned, which is a continuation of application Ser. No. 589,877, filed June 24, 1975, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a pressure sensitive recording sheet.
2. Description of the Prior Art
There have been heretofore known inscribable labels. The simplest ones are those made of paper, but are of very poor water resistance and can not be used outdoors or in water. Another type of inscribable label is composed of a colored plastic base sheet, a crystalline wax coated thereon and a transparent film overlying the crystalline wax coat and the inscription can be effected from the transparent film side. However, this label has poor heat and light resistances and is not suitable for a long time use outdoors. A further conventional inscribable label is a so-called "embossing tape" composed of a colored backing sheet and a transparent film overlying the backing sheet which becomes whitened when subjected to deformation by a punch-die. The embossing tape has an excellent circumstance resistance. However, the inscription can not be made by a usual stylus or ball-point pen, but only by a special tool such as a punch-die.
SUMMARY OF THE INVENTION
According to one aspect of the present invention, there is provided a pressure sensitive recording sheet which comprises an opaque pressure clarifiable layer and a support sheet under the opaque pressure clarifiable layer, the support sheet having a color contrasting with the color of the opaque pressure clarifiable layer.
According to another aspect of the present invention, there is provided a pressure sensitive recording sheet which comprises the layer structure as mentioned above and additionally a transparent protective layer is provided on the opaque pressure clarifiable layer.
According to a further aspect of the present invention, there is provided a pressure sensitive recording sheet which comprises an opaque pressure clarifiable layer, a transparent support sheet under the opaque pressure clarifiable layer, and a colored adhesive layer under the transparent support sheet, and if desired, a transparent protective layer is provided on the opaque pressure clarifiable layer.
An object of the present invention is to provide a pressure sensitive recording sheet having excellent heat resistance, light resistance and water resistance, free from formation of crack and capable of being inscribed with a usual writing instrument.
Another object of the present invention is to provide a pressure sensitive recording sheet which can be easily produced.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1A and FIGS. 2-FIG. 18 diagrammatically show enlarged cross sectional views of embodiments of the pressure sensitive recording sheet according to the present invention; and
FIG. 1B diagrammatically shows that an inscription to a pressure sensitive recording sheet of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Support sheets used for the present invention may be flexible or non-flexible materials and transparent or opaque depending upon the use. Further, the shape is not critical, but usually such forms as thin sheets, foils and films are preferable.
Representative support sheets include papers such as kraft paper and the like, plastic films such as acetylcellulose, polypropylene, polyethylene, polyester, and soft or hard polyvinyl chloride films and the like, and metal foils such as aluminum foil, copper foil and the like.
Opaque pressure clarifiable layers used in the present invention are layers which are opaque at an ordinary state and transparentize when a pressure is applied to them. These materials transparentize when a pressure such as that of a writing instrument and that of typewriter printing heads is applied to them.
Representative materials for the opaque pressure clarifiable layers are polyfluoroethylenes such as polytetrafluoroethylene and the like, and polyethylene such as low pressure process polyethylene and the like. There is preferably used unbaked polytetrafluoroethylene. This is a polytetrafluoroethylene as shaped by a paste extruding method and not followed by a heating treatment.
The transparent protective layer used in the present invention may be a transparent sheet, for example, film, which can transfer pressure patterns applied thereto to the opaque pressure clarifiable layer under the transparent protective layer and can protect the opaque pressure clarifiable layer from, for example, dirt, scratching and other damages. The transparent protective layer may serve for controlling the pressure sensitivity of the pressure sensitive recording sheet.
Representative materials for the transparent protective layer include thin transparent acetylcellulose, polypropylene, polyethylene, polyester, and soft or hard polyvinyl chloride films.
The pressure sensitive recording sheet comprising an opaque pressure clarifiable layer, a support sheet and, if desired, a transparent protective layer being provided on the opaque pressure clarifiable layer according to the present invention may have an adhesive layer under the support sheet, or both of an adhesive layer under the support sheet and a release treated layer on the top of the pressure sensitive recording sheet, that is, on the opaque pressure clarifiable layer when no transparent protective layer is mounted thereon, or on the transparent protective layer. Further if desired, a release layer may be provided under the adhesive layer. When the release layer is provided under the adhesive layer, the release treated layer on the top of the pressure sensitive recording sheet is usually unnecessary.
As the adhesive layers, there may be used usual adhesive materials such as, for example, pressure sensitive adhesives and water soluble adhesives. Representative pressure sensitive adhesive layers may be produced by dissolving rubbers such as neoprene, vinyl resins such as polyvinyl chloride, high polymers of cellulose series such as ethyl cellulose, together with a adhesivity imparting agent such as D.O.P., dammar and the like, in a solvent such as, for example, solvent naphtha, applying to the support sheet, and drying.
The release treated layer may be produced by conventional method for producing a release coat, for example, applying a coating liquid containing a silicone resin, a reaction accelerator and a solvent and drying.
The release layer may be a layer of a conventional release agent or a release layer formed on a certain sheet, for example, a release paper produced by applying a coating solution composed of a silicone resin, a reaction accelerator and a solvent to a paper and drying. For example, the surface coated with the release agent is placed on the adhesive surface of the adhesive layer.
According to the present invention, it is very important that the layers of the pressure sensitive recording sheet are combined in such a manner that the appearance of the opaque pressure clarifiable layer is different from the appearance of the portions transparentized by applying a pressure. The difference of appearance may be difference of color, shade of color and other visual properties of the surface states.
For example, in case of a pressure sensitive recording sheet composed of an adhesive layer, an opaque colored support sheet, an opaque pressure clarifiable layer and a colorless transparent release treated layer, when the color of the opaque pressure clarifiable layer and that of the opaque colored support sheet are different from each other. The color appearing at the transparentized portion is that of the opaque colored support sheet. When the transparentized portion of the opaque pressure clarifiable layer is not colorless, but colored-transparent, the color appearing at the transparentized portion is a mixed color of the opaque colored support sheet and the color of the transparentized portion of the opaque pressure clarifiable layer. Further, when there is a transparent protective layer or a release treated layer or there are both a transparent protective layer and a release treated layer and they are colored-transparent, the color appearing at the transparentized portion is a mixed color of them, and the color appearing a untransparentized portion of the opaque pressure clarifiable layer is a mixed color of color or colors of the layers overlying the opaque pressure clarifiable layer and color of the opaque pressure clarifiable layer. Further, if adhesives used for bonding those layers are colored-transparent, the resulting appearing color is a mixed color formed by adding the color or colors of the adhesive or adhesives.
In view of the foregoing, it is very important to select the color of each layer in such a manner that the color appearing at the transparentized portion of the opaque pressure clarifiable layer is different from the color appearing at the untransparentized portion.
The above explanation is directed to the difference of color only, but it will be easily realized that any kind of visual difference is usable according to the present invention.
In general, a pressure sensitive recording sheet comprising a colorless transparent protective layer, an opaque pressure clarifiable layer and an opaque support sheet having a color different from that of the opaque pressure clarifiable layer, particularly a color well contrasting with that of the opaque pressure clarifiable layer, is preferable. The contrast of colors may be optionally selected depending upon the use of the recording sheet, for example, beautiful sense, warning, and usual indication.
Sizes and shapes of layers constituting the pressure sensitive recording sheet may be different from each other and may be selected optionally depending upon the use of the recording sheet. Various combinations of the sizes and shapes are illustrated in the drawing though they are not limited to the illustrated ones.
In FIGS. 6, 7, 16, 17, etc., each layer has the same size and shape. In FIGS. 1A, 1B, 2, 3, etc., the transparent protective layer and the support sheet have the same size and shape. In FIG. 4 etc., the opaque pressure clarifiable layer and the support sheet have the same size and shape. In FIG. 5 etc., shape and size of the opaque pressure clarifiable layer is different from those of the support sheet. In FIGS. 1A, 1B, 2, 3, 4, 5, 10, 13, 15 and 18, the width of the opaque pressure clarifiable layer is narrower than other layers such as the support sheet. In these cases, the center portion (the opaque pressure clarifiable layer) can have a color different from that of the both edge portions. Thus it is possible to select two colors of excellent and beautiful contrast. Since it is possible to make the color appearing at the transparentized portion the same as that of the edge portion so that the color appearing at the transparentized portion can be predicted by the color of the edge portion. Furthermore, it is possible to classify the articles to which the pressure sensitive recording sheet is to be adhered, by the colors of the edge portions.
The layers and sheets constituting the pressure sensitive recording sheet may be assembled in any way depending upon its use as far as each layer or sheet is not separated away. The layers and sheets may be assembled by using adhesives or fusing or sealing. The layers and sheets can be assembled not only by assembling each layer and sheet separately prepared, but also can be produced by directly coating one or more of them.
Upon assembling it should be avoid to disturb or deteriorate the function of the recording sheet. For example, it is not allowable to use an opaque adhesive between the transparent protective layer and the opaque pressure clarifiable layer.
For the purpose of adhering the pressure sensitive recording sheet to an article though the recording sheet may be used without adhering to an article, various adhering means may be employed. For example, an adhesive layer is provided under the support sheet.
The pressure sensitive recording sheet may be commercially in a various forms such as tape type, sheet type and the like. The one of the tape type can be wound and sold in a form of a roll. When the top layer of pressure sensitive recording sheet has a release property, the roll in case of tape type having an adhesive layer can be made without using any release layer or applying a releasing treatment, end the sheet type ones can be piled without using any release sheet except a release layer for the bottom one. When the adhesive layer is made of a water soluble adhesive, in usual a release layer or sheet is not necessary.
One of preferable embodiments of the present invention is a pressure sensitive recording sheet comprising a transparent support sheet and a colored adhseive layer having a color contrasting with the color of the opaque pressure clarifiable layer.
The colored adhesive layer may be a colored pressure sensitive adhesive layer composed of a coloring agent such as benzidine yellow, phthatocyanine blue, phthalocyanine green, soluble azo dye, chromium oxide, zinc oxide and the like, and an adhesive composition, for example, rubber series ahdesives such as neoprene and the like, vinyl series adhesives such as polyvinyl chloride and the like, cellulosic high polymers such as ethylcellulose and the like together with an adhesiveness imparting agent such as dammar, D.O.P. and the like. The colored adhesive layer composition may be applied to the transparent support sheet by dissolving the composition in a solvent such as solvent naphtha and the like. Further, a colored water soluble adhesive layer may be employed. The colored adhesive layer may be transparent or not.
Referring to FIG. 1A, an opaque pressure clarifiable layer 2 is interposed between a transparent protective layer 1 and a support sheet 3 and transparent protective layer 1 is adhered to opaque pressure clarifiable layer 2 and support sheet 3 with an adhesive 10.
Referring to FIG. 1B, a pressure is applied to the pressure sensitive recording sheet of FIG. 1A by a stylus 20 and the pressed portion 2' of opaque pressure clarifiable layer 2 is transparentized. Thus the surface of support sheet 3 corresponding to the portion 2' can be seen through the portion 2' and this is the recording
Referring to FIG. 2, an adhesive layer 11 is applied to the support sheet 3 of the recording sheet of FIG. 1A and further a release paper 4 is applied to adhesive layer 11. Upon using, release paper 4 is removed and the recording sheet is applied to a surface of article.
Referring to FIG. 3, an opaque pressure clarifiable layer 2 is interposed between a transparent protective layer 1 and a support sheet 3 and the both edge portions of transparent protective layer 1 and support sheet 3 are adhered to each other, and an adhesive layer 11 and a release paper 4 are provided.
Referring to FIG. 4, a transparent protective layer 1, an opaque pressure clarifiable layer 2 and a support sheet 3 are closely contacted with one another and fixed to another support sheet 5 by using an adhesive agent 13 through the edge portions of transparent protective layer 1 and the bottom side of opaque pressure clarifiable layer 2, and a combination of an adhesive layer 11 and a release paper 4 is provided on the back surface of support sheet 5. According to this pressure sensitive recording sheet, the color of support sheet 5 can be different from colors of opaque pressure clarifiable layer 2 and support sheet 3 and thereby, when letters of signs are inscribed in the recording sheet, the color of the inscribed letters or signs is that of support sheet 3 and the color adjacent to the letters or signs is that of opaque pressure clarifiable layer 2 and the color at the both edge portions is that of support sheet 5 and thus, there is obtained a beautiful three color label.
Referring to FIG. 5, the pressure sensitive recording sheet is composed of an opaque clarifiable layer 2 adhered to a support sheet 3 by an adhesive agent 14. On the bottom side of support sheet 3 may be provided adhesive layer 11 and release layer 4 as shown in FIG. 2. When an opaque pressure clarifiable layer 2 is not covered with any protective layer as in this embodiment, it is preferable to use an opaque pressure clarifiable layer somewhat thicker than that covered with a protective layer, and further it is preferred that the opaque pressure clarifiable layer can sufficiently withstand external physical or chemical action.
Referring to FIG. 6, the pressure sensitive recording sheet is composed of a transparent protective layer 1, an opaque pressure clarifiable layer 2, and support sheet 3 which are assembled by using adhesive layers 15 and 16, and further an adhesive layer 11 and release layer 4. The width of each layer is the same as each other.
Referring to FIG. 7, the recording sheet is the same as that of FIG. 6 except that there are not the transparent protective layer and thereby the adhesive layer 15 and the opaque pressure clarifiable layer 2 is exposed and inscription is directly made on the opaque pressure clarifiable layer 2.
Referring to FIG. 8, the pressure sensitive layer is composed of an opaque pressure clarifiable layer 3 adhered to a transparent support sheet 4 with an adhesive layer 8, and a colored adhesive layer 5 under the transparent support sheet 4.
Referring to FIG. 9, the recording sheet is the same as that of FIG. 8 except that a release layer 6 is provided. Upon using, release layer 6 is removed and the recording sheet is adhered to an article with the adhesive layer 5.
Referring to FIG. 10, the pressure sensitive recording sheet has the same structure as that of FIG. 9 except that the width of opaque pressure clarifiable layer 3 and therefore that of adhesive layer 8 is narrower than other layers. On the upper side, there appear a color zone of the layer 3 at the center portion and color zones of the colored adhesive layer 5 at both edge portions when the transparent support sheet is colorless or color zones of a mixed color of the transparent support sheet 4 and the color adhesive layer 5 when the transparent support sheet is colored. Thus, the appearance is beautiful. Upon using, the release lyer 6 is removed and the recording sheet is adhered to an article.
Referring to FIG. 11, the pressure sensitive recording sheet is composed of a transparent protective layer 1, an adhesive layer 2, an opaque pressure clarifiable layer 3, an adhesive layer 7, a transparent support sheet 4 and a colored adhesive layer 5.
Referring to FIG. 12, the recording sheet is the same as that of FIG. 11 except that a release layer 6 is provided under the colored adhesive layer 5. The release layer 6 is removed upon using and the recording sheet is adhered to an article.
Referring to FIG. 13 the layer structure of the pressure sensitive recording sheet is the same as that of FIG. 12 except that width of the opaque pressure clarifiable layer is narrower than other layers and the adhesive layer 7 is not necessary. The appearance of this recording sheet is beautiful in a similar way to that of FIG. 10.
The recording sheets as mentioned above having a release sheet are suitable for use as sheet type products.
Referring to FIG. 14, the pressure sensitive recording sheet is composed of a release treated layer 9, an opaque pressure clarifiable layer 3, an adhesive layer 8, a transparent support sheet 4 and a colored adhesive layer 5. This kind of recording sheet is suitable for use as roll type products by winding the recording sheet in a form of tape.
Referring to FIG. 15, the pressure sensitive recording sheet is composed of a release treated layer 9, a transparent protective layer 1, an adhesive layer 2, an opaque pressure clarifiable layer 3, a transparent support layer 4 and a colored adhesive layer 5 where the width of opaque pressure clarifiable layer 3 is narrower than that of other layers. The appearance of this recording sheet is similar to that of FIG. 10. This is suitable for roll type products. Naturally, the recording sheets of FIG. 14 and FIG. 15 may be piled without any additional releasing means so that they can be also used as a kind of sheet type product.
Referring to FIG. 16, the pressure sensitive recording sheet is composed of a release treated layer 5, an opaque pressure clarifiable layer 4, an adhesive layer 3, an opaque colored support sheet 2 and an adhesive layer 1, and is suitable for roll type products.
Referring to FIG. 17, this pressure sensitive recording sheet is the same as that of FIG. 16 except that a transparent protective layer 6 and an adhesive layer 7 are additionally provided. The release treated layer 5 may be formed on the transparent protective layer 6 by treating the surface of the layer 6.
Referring to FIG. 18, the pressure sensitive recording sheet is the same as that of FIG. 17 except that the width of opaque pressure clarifiable layer 4 is narrower than other layers and thereby the adhesive layer 3 is omitted. A two-color recording sheet is obtained.
In a similar way, the recording sheet of FIG. 16 can be a two-color recording sheet by using a narrower opaque pressure clarifiable layer 3. In such case, the edge portions of the release treated layer 5 is provided directly on the opaque colored support sheet 2.
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A pressure sensitive member comprises a base sheet and an opaque pressure clarifiable layer overlying the substrate and the color of the substrate being different from that of the opaque clarifiable layer.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This non-provisional patent application claims priority under 35 U.S.C. §119(a) from Patent Application No. 200810142381.1 filed in The People's Republic of China on Aug. 15, 2008.
FIELD OF THE INVENTION
[0002] This invention relates to a motor assembly, and in particular, to a motor assembly having a force transmission structure.
BACKGROUND OF THE INVENTION
[0003] Usually, a window lift system for a vehicle window comprises a driving motor, a lift device for moving up or down the glass of the window, and a force transmission structure for transmitting rotation of the output shaft of the motor to the lift device. The transmission structure comprises a drive plate and a shaft coupled to the drive plate. The drive plate is connected to the output shaft of the motor via a gear train. The shaft is connected to the lift device via a pinion attached to an end of the shaft and meshed with a gear of the lift device. In operation, the motor drives the drive plate to rotate. The drive plate drivingly rotates the shaft to thereby cause the lift device to move the glass of the window up or down.
[0004] Conventionally, the shaft is coupled to the drive plate via a cylindrical coupling end with two flat surfaces at opposite sides thereof fittingly received in a waist-shaped hole of the drive plate. Two opposite flat interfaces are formed between the coupling end of the shaft and the hole of the drive plate. In operation, two reverse forces are exerted on the two flat surfaces of the coupling end of the shaft, which will generate impact on the shaft and the drive plate to thereby generate vibration and noise.
[0005] As such, there is a desire for an improved transition structure which can solve the above-mentioned problems.
SUMMARY OF THE INVENTION
[0006] Accordingly, in one aspect thereof, the present invention provides a force transmission structure comprising: a drive plate having a mounting hole and a shaft fitted to the mounting hole for rotation with the drive plate, wherein the mounting hole has at least three sections interconnected with one another at a common area, the shaft has a toothed portion with at least three teeth fittingly received in the sections of the mounting hole such that the shaft is fixed to rotate with the drive plate.
[0007] Preferably, the drive plate comprises a body and a coupling formed at the center of the body, the coupling is deeper than the body in the axial direction of the body, the mounting hole being formed in the coupling.
[0008] Preferably, the coupling has buffer holes respectively located between adjacent sections.
[0009] Preferably, the drive plate has a plurality of protrusions formed on a first side of the body and configured to engage with a driving member such that the driving member is able to drive the drive plate, the shaft further comprises a pinion configured to drive a driven member.
[0010] Preferably, the drive plate further comprises a plurality of ribs formed at an opposite second side of the body.
[0011] Preferably, the mounting hole and the toothed portion are Y-shaped.
[0012] Preferably, the drive plate is made of a plastics material.
[0013] According to a second aspect, the present invention provides a motor assembly comprising: a motor; a force transmission structure comprising a drive plate and a shaft; and a gear train connecting the motor to the drive plate for driving the drive plate; wherein the drive plate has a mounting hole with at least three sections interconnected with one another at a common area, the shaft has a toothed portion with at least three teeth fittingly received in the sections of the mounting hole of the drive plate such that the shaft is fixed to rotate with the drive plate.
[0014] Preferably, the gear train comprises a worm driven by the motor, a worm gear meshed with the worm, and a damper attached to and rotatable with the worm gear, the drive plate being driven by the worm gear through the damper.
[0015] Preferably, the worm comprises an inner ring, an outer ring, and a plurality of ribs extending from the inner ring to the outer ring, the damper being received in a space formed between the inner ring and the outer ring and having a plurality of first slots for fittingly receiving the ribs respectively.
[0016] Preferably, the drive plate comprises a body and a plurality of protrusions formed at one side of the body, and the damper has a plurality of second slots engaging with the protrusions of the drive plate.
[0017] Preferably, the protrusions are V-shaped, the width of the protrusions increasing gradually from the inner most portion towards the outer most portion in a radial direction of the body.
[0018] Preferably, the drive plate further comprises a coupling formed at the center of the body, the coupling having a greater axial depth than the body, and the mounting hole being formed in the coupling.
[0019] Preferably, the coupling has buffer holes respectively located between adjacent sections of the mounting hole.
[0020] Preferably, the mounting hole and the toothed portion of the shaft are Y-shaped.
[0021] Preferably, the drive plate is made of a plastics material, and the damper is made of rubber.
[0022] Preferably, the shaft further comprises a pinion for driving a gear of a window lift system.
[0023] Preferably, the shaft is held captive within the mounting hole by a circlip located within a groove in the distal end of the toothed portion.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] A preferred embodiment of the invention will now be described, by way of example only, with reference to figures of the accompanying drawings. In the figures, identical structures, elements or parts that appear in more than one figure are generally labelled with a same reference numeral in all the figures in which they appear. Dimensions of components and features shown in the figures are generally chosen for convenience and clarity of presentation and are not necessarily shown to scale. The figures are listed below.
[0025] FIG. 1 is a partial cross sectional view of a motor assembly in accordance with an embodiment of the present invention;
[0026] FIG. 2 is an exploded view of the motor assembly of FIG. 1 ;
[0027] FIG. 3 is a plan view of a drive plate of the motor assembly of FIG. 1 ;
[0028] FIG. 4 is an isometric view of a shaft of the motor assembly of FIG. 1 ;
[0029] FIG. 5 is an assembled view of the drive plate of FIG. 3 and the shaft of FIG. 4 ; and
[0030] FIGS. 6A and 6B are schematic diagrams showing forces acting between the drive plate and the shaft.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0031] FIG. 1 shows a partial cross sectional view of a motor assembly in accordance with the preferred embodiment of the present invention. The motor assembly comprises a motor 10 and a gear train driven by the motor 10 . The gear train includes a force transmission structure. The gear train is contained in a gear housing 14 and a capstan 16 , which is a part of a window lift mechanism, is visible at the back. The capstan is driven through gears (not shown) by the motor assembly.
[0032] FIG. 2 is an exploded view of the gear train, with the gear housing removed, to show the various components. The gear train comprises a worm 20 fitted to a motor shaft 12 driven by the motor 10 , a worm gear 30 which meshes with the worm 20 , a damper 40 , a drive plate 50 and a shaft 60 . The force transmission structure comprises the drive plate 50 and the shaft 60 . The worm 20 may be press fitted to the motor shaft 12 . Alternatively, the worm 20 may be formed integral with the motor shaft 12 . The worm gear 30 comprises an inner ring 31 , an outer ring 33 , and a plurality of ribs 32 radially extending from the inner ring to the outer ring. Teeth are formed at the outer circumferential surface of the outer ring 33 , for meshing with the worm 20 . The damper 40 is made of rubber material, has a through opening at the center thereof and has a plurality of first slots 41 and second slots 42 extending radially thereof. The slots 41 , 42 are arranged alternately in the circumferential direction.
[0033] Referring also to FIG. 3 , the drive plate 50 , which may be made of an engineering plastics material, comprises a round body 52 , a coupling 54 formed at the center of the body 52 , a plurality of V-shaped protrusions 56 formed on one side of the body 52 , and a plurality of ribs 58 formed on the opposite side of the body 52 . The coupling 54 extends beyond the body 52 in opposite axial directions of the body 52 and therefore the coupling 54 has a greater depth or thickness than the body 52 . The coupling 54 has a Y-shaped mounting hole 55 at the center thereof, that is, the mounting hole 55 comprises three sections interconnected at the center thereof. Preferably, the coupling 54 further has a plurality of buffer holes 57 . In the embodiment, the buffer holes 57 are three blind holes which do not pass completely through the coupling 54 axially, and are evenly distributed in the circumferential direction, each one being located between adjacent sections of the Y-shaped hole 55 . In this embodiment, the protrusions 56 comprise three protrusions 56 evenly distributed in the circumferential direction, the width of the protrusions increasing gradually from the inner most portion towards the outer most portion in the radial direction of the body 52 . The central line of each protrusion 56 extends radially through the center of the body 52 . The protrusions 56 are shaped and sized to fit the second slots 42 of the damper 40 .
[0034] Referring to FIG. 4 , the shaft 60 , which is the output shaft of the gearbox in the preferred embodiment, comprises a round portion 61 , a toothed portion 62 formed at one end of the round portion, and a pinion 64 formed at the other end of the round portion. The toothed portion 62 has a Y-shaped cross section and comprises three teeth evenly distributed in a circumferential direction of the shaft 60 . The shape and size of the teeth of the toothed portion 62 conform to that of the mounting hole 55 of the drive plate 50 . Preferably, the shaft 60 is made of low alloy steel. Alternatively, the shaft 60 may be made of other metal material. The pinion 64 is configured to couple with a gear, such as a gear train of a lift mechanism of a window lift system.
[0035] Referring to FIGS. 1 and 5 , when assembled, the damper 40 is located in a spaced formed between the inner ring 31 and outer ring 33 of the worm 30 and the ribs 32 of the worm 30 are received in the first slots 41 of the damper 40 . The protrusions 56 of the drive plate 50 are respectively, interferentially and fittingly received in the second slots 42 of the damper 40 . Thus, the drive plate 50 is rotated by the damper 40 and the worm gear 30 when the worm 20 drives the worm gear 30 .
[0036] The Y-shaped toothed portion 62 of the shaft 60 extends through the inner ring 31 of the worm gear 30 to be fitted in the Y-shaped mounting hole 55 of the drive plate 50 . The free end of the toothed portion 62 of the shaft 60 extends beyond the coupling 54 . A circlip 70 is fitted in a slot 66 formed at the free end of the toothed portion 62 to prevent the toothed portion 62 escaping from the mounting hole 55 . In operation, the motor 10 rotates the motor shaft 12 , which rotates the worm 20 , which drives the worm gear 30 , which rotates the drive plate 50 via the damper 40 , and thus rotates the shaft 60 . The drive plate 50 drives the shaft 60 to rotate by the Y-shaped mounting hole 55 of the drive plate mating with the Y-shaped toothed portion 62 of the shaft 60 . Consequently, the pinion 64 drives the capstan 16 via one or more gears (not shown) of the window lift system to thereby raise up or lower down the glass of the window. The window lift system may have a wire which is wound about the capstan to raise or lower the glass
[0037] Referring to FIGS. 6A and 6B , in the embodiment of the present invention, when the shaft 60 is rotated by the drive plate 50 , three equal forces A, B, C from the coupling 54 are exerted on the three teeth of the toothed portion 62 of the shaft 60 respectively. These three forces A, B, C exerting on the three teeth of the toothed portion 62 constitute a triangle as shown in FIG. 6B . Therefore, the shaft 60 is rotated stably to thereby move up and/or down the glass of the window lift system quietly. Furthermore, the contact area between the teeth of the shaft 60 and the coupling 54 of the drive plate 50 is greater than that in the traditional design, which results in the connection between coupler and the shaft being able to withstand a greater torque. Moreover, the drive plate 50 is ideally made of an engineering plastics material which has good strength and resistance to impact and can absorb vibration, which is helpful to reduce the noise generated by the gear train as well. The buffer holes 57 aid molding of the drive plate by providing relief when the plastics material is cooling in the mould to reduce distortion of the mounting hole 55 .
[0038] In the description and claims of the present application, each of the verbs “comprise”, “include”, “contain” and “have”, and variations thereof, are used in an inclusive sense, to specify the presence of the stated item but not to exclude the presence of additional items.
[0039] Although the invention is described with reference to one or more preferred embodiments, it should be appreciated by those skilled in the art that various modifications are possible. Therefore, the scope of the invention is to be determined by reference to the claims that follow.
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A motor assembly includes a motor, a force transmission structure comprising a drive plate and a shaft, and a gear train connecting the motor to the drive plate for transmitting rotation of the motor to the drive plate. The drive plate has a mounting hole with at least three sections interconnected with one another at a common area, the shaft has a toothed portion with at least three teeth fittingly received in the sections of the mounting hole of the drive plate such that the shaft is rotated with the drive plate.
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BACKGROUND
[0001] The present invention relates to a method of managing power consumption of a portable computer, and more particularly to a method of managing power consumption of a portable computer connected to a wireless device with a connection interface for a wireless communication system. The portable computer with a battery can include a PDA mobile phone, smart phone notebook PC, and the like.
[0002] To attain better working efficiency in current portable computers, the operating speed and capability of a mobile CPU, which is used particularly for portable computers, has been enhanced. Therefore, the power consumption of mobile CPUs for the portable computers has increased relatively, resulting in greater heat. Hence, both Intel and Microsoft have provided excellent electronic power management for mobile CPUs of portable computers, such as Advanced Configuration and Power Interface (ACPI) and Speed step. ACPI has defined five states from C0 to C4, the higher states have better electric power management efficiency. However, mobile. CPUs of portable computers still have some drawbacks, e.g., the newly promoted mobile CPU speed of portable computers on the market always lags behind desktop CPUs by at least three to six months, and the price is also higher than desktop PCs.
[0003] The issue of power saving is important for a portable computer which needs a battery as a power source. If the system power consumption can be reduced, battery life-time (working time) can be extended.
[0004] US patent publication No. 2004/0078606 is a prior art which provides a power management method for portable computers in order to dynamically tune up voltage and frequency of a portable computer, and maintains normal operation of the portable computer. The components for adjustment are the External Clock and voltage of CPU, frequency of memory, or frequency and performance of the Video Graphics Array (VGA) card or the frequency of memory.
[0005] The apparatus of the related art, however, can not further improve power saving for a portable computer connected to a wireless device in a wireless communication system. The power consumption required by the data transmission of the transmitter and the receiver of the wireless device in the communication system is large. This situation can occur for a PDA mobile phone, smart phone, notebook PC with a wireless device, and the like.
[0006] To solve the described problem, the present invention provides a power management method for a wireless communication system which includes an AP and a portable computer connected to a wireless device.
SUMMARY
[0007] The present invention provides an apparatus and method for a one-button power-saving WLAN system with an USB interface triggered by a one-button switch.
[0008] The present invention provides an apparatus and method of reducing power consumption of a portable computer applied in a wireless communication system, the wireless communication system includes an AP and a wireless device connected to a host computer with a USB interface by adjusting the USB supporting rate and data rate between AP and the wireless device.
[0009] The present invention relates to a power management method for portable computers with a wireless device and detects the power source of the portable computer through a power source detection circuit during operation, and dynamically changes any one of the following: the supporting rate of the connection interface between a wireless device and the portable computer; the data rate between the AP (Access Point) and the wireless device. Moreover, the invention provides a plurality of input methods to trigger the power saving mode of a portable computer for achieving reduced power consumption.
DESCRIPTION OF THE DRAWINGS
[0010] The invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein:
[0011] FIG. 1 is a function block diagram of a portable computer according to the first embodiment of the invention.
[0012] FIG. 2 is a flowchart showing the steps of a power management method of the first embodiment applied to the portable computer in FIG. 1 .
[0013] FIG. 3 is a function block diagram of a portable computer includes a wireless device according to the second embodiment of the invention.
[0014] FIG. 4 is a flowchart showing the detailed steps of step A of FIG. 2 .
[0015] FIG. 5 is a table related to the standards for an 802.11a/b/g, and USB interface in the present invention.
DESCRIPTION
[0016] Finalized in 2001, USB 2.0 is a complete overhaul to the Universal Serial Bus input/output bus protocol which achieves substantial gain over USB 1.1 standard did. As an aside, USB mice and keyboards require only 1.5 Mbits/s to function.
[0017] USB 1.1 allowed a maximum transfer rate of 12 Mbits/second. The USB 2.0 specification incorporates three speeds: Hi-Speed, Full-Speed and Low-Speed. Low Speed USB mode is 1.5 Mbits/second, Full Speed USB mode is 12 Mbits/second, and Hi-Speed USB mode is up to 480 Mbits/second.
FIRST PREFERRED EMBODIMENT (ONE-SWITCH POWER-SAVING FUNCTION)
[0018] FIG. 1 is a function block diagram of a portable computer according to the first embodiment of the invention. The portable computer 120 , such as a notebook computer, communicates with an access point (AP) 130 through a wireless device 110 .
[0019] The wireless device 110 connects to the portable computer 120 via USB interface 170 . The wireless device 110 , such as 802.11a, 802.11b or 802.11g wireless device, includes an RF section 112 , a MAC (Medium Access Control) section 116 and a baseband section 114 , communicating with the AP 130 using a data rate. The portable computer 120 includes managing controller 140 which comprises an USB interface mode controller 142 for changing USB interface mode according to detaching and re-attaching operation and a data rate controller 144 for adjusting data transmission rate between the wireless device 110 and the AP 130 , a power source detector 126 , a power unit 125 and a one-button switch 150 connected to a GPIO (General Purpose Input Output) 120 , and the GPIO 120 connected to a processor 122 .
[0020] The power unit 125 comprises a battery 128 and power supply 160 which receives and converts an external AC source, respectively powering the portable computer 120 .
[0021] In this embodiment, when the switch 150 is activated or pushed, a power-saving event will be triggered. The power source detector 126 is used to recognize that the portable computer 120 is powered by the battery 128 or the power supply 160 and to detect the power level of the power unit 125 .
[0022] FIG. 2 is a flowchart showing the steps of a power management method of the first embodiment applied to the portable computer 120 in FIG. 1 .
[0023] At step S 300 , the wireless device 110 is plugged into the portable computer 120 through the USB interface 170 .
[0024] At step S 305 , it is detected if a power-saving event is trigged (when pushing the switch 150 ) or a power-saving signal is input from the input device (such as the keyboard of the portable computer 120 ). When the power-saving event or the power-saving signal is detected, step S 310 is carried out otherwise step S 305 is repeated.
[0025] At step S 310 , if the portable computer 120 is powered by the battery 128 based on the detection of the power source detector 126 , then step S 340 is carried out otherwise step S 320 is carried out.
[0026] At step S 320 , if the power level of the power supply 160 is low power, then step S 340 is carried out otherwise step S 330 is carried out.
[0027] At step S 330 , if the power-saving signal instructs to reduce the data rate between the AP 130 and the wireless device 110 through the control of the data rate controller 144 , then step S 360 is carried out to reduce the data rate between AP and the wireless device, otherwise step A is performed. In this embodiment step A does nothing, i.e., at step S 360 , the power consumption of the portable computer 120 is reduced by reducing the data rate.
[0028] At step S 340 , the USB interface mode is changed by performing a detaching and re-attaching operation through the control of the USB interface mode controller 142 and the USB supporting rate is set to full speed. In this embodiment, if the default USB interface mode is USB 2.0, it can be changed to be USB 1.1 interface mode in response to the power-saving event. Another implementation or option as described below, if the default USB interface mode is USB 2.0 with supporting rate up to 480 Mbps (H mode), the supporting rate is reduced to a second supporting rate such as 1.2 Mbps (F mode) or 1.5 Mbps (L mode) in response to the power-saving event; if the default USB interface mode is USB 1.1 with a supporting rate of up to 12 Mbps (F mode), the supporting rate is reduced to a second supporting rate such as 1.5 Mbps (L mode) in response to the power-saving event. After step S 340 is performed, step S 330 is subsequently performed.
[0029] In the other words, the present invention provides a power management method for managing power consumption of a portable computer having a battery and communicating with an access point (AP) through a wireless device connected to the portable computer via a USB interface. The USB interface at least has a first and second mode respectively with a first and second supporting rate less than the first supporting rate. The AP communicates with the wireless device with a first data rate. The portable computer works under a first clock frequency and a first reference voltage, wherein the portable computer includes a first circuit which is in standby or suspends its function in the power-saving mode, and the wireless device includes a second circuit which is in standby or suspends its function in power-saving mode, the method comprises the steps of:
[0030] (a) inputting a power-saving signal through an input device, such as keyboard of the portable computer;
[0031] (b) detaching and re-attaching the wireless device to the portable computer to change the USB interface mode from the first supporting rate to the second supporting rate, wherein the second supporting rate is less than the first supporting rate;
[0032] (c) decrease the first data rate to a second data rate between the AP and the wireless device, wherein the second date rate is less than the first data rate.
[0033] The power saving function is triggered when:
[0034] A. The user determines the time to enforce the system to execute the power-saving function which is triggered by pushing a button, i.e., the power-saving signal is generated via a switch coupled to a GPIO to trigger the power-saving function.
[0000] B. The system itself determines when to execute a power-saving function, as following.
[0000]
a. The power source is changed from AC to battery, i.e., the AC plug of the portable computer is detached.
b. Low power indication for system power is detected. It can be implemented by a system event received by the portable computer, then notify the USB device, USB interface mode controller and data rate controller, to execute the power-saving function.
[0037] C. The USB interface only needs a bandwidth of 12 Mbps (i.e. USB Full Speed) for transmission.
[0038] For example, the maximum data rate is 54 Mbps for an 802.11a/g wireless device, the portable computer can reduce the USB supporting rate from 480 Mbps to 12 Mbps to reduce the power consumption of the USB interface.
[0039] For example, when the data rate of WLAN is less than a threshold, i.e., the bottleneck is the data rate, the portable computer can reduce the data rate of the wireless device to reduce the power consumption of the wireless device.
[0040] U.S. Pat. No. 6,765,416B2, entitled “Device for recognizing power source and associated method”, disclosed a device for recognizing a power source by voltage-dividing circuits can be applied in the circuit of power source detector 126 in FIG. 1 . The power source detector 126 is used to detect that the current power source is external AC power supply 160 or the battery 128 . If the power source is battery or detected to be low power, the portable computer will reduce the USB supporting rate or reduce the data rate between the wireless device and the AP to reduce the power consumption.
SECOND PREFERRED EMBODIMENT
[0041] FIG. 3 is a function block diagram of a portable computer including a wireless device according to the second embodiment of the invention. The portable computer 320 , such as a notebook computer, communicates with an access point (AP) 330 through a wireless device 310 which can be provided inside the portable computer 320 or simply serving as an external device.
[0042] The wireless device 310 connects to the portable computer 320 via a connection interface 370 such as a USB interface. The wireless device 310 , such as 802.11a, 802.11b or 802.11g wireless device, includes an RF section 312 , a MAC (Medium Access Control) section 316 and a baseband section 314 , communicating with the AP 330 using a data rate. The portable computer 320 includes managing controller 340 which comprises an connection interface mode controller 342 (such as a USB controller) for changing the connection interface mode according to detaching and re-attaching operation of the connection interface 370 , a data rate controller 344 for adjusting the data transmission rate between the wireless device 310 and the AP 330 , a power unit 325 and a power-saving input device 350 which includes a power source detector 326 and an input device 352 and is connected to a processor 322 .
[0043] The power unit 325 comprises a battery 328 and power supply 360 which receives and converts an external AC source, respectively powering the portable computer 320 .
[0044] The power source detector 326 is used to recognize that the portable computer 320 is powered by the battery 328 or the power supply 360 and to detect the power level of the power unit 325 .
[0045] In this embodiment, through the power-saving input device 350 , a power-saving event can be triggered and the USB controller is notified to response to the power-saving event. The managing controller 340 further includes a clock generator 348 , a reference voltage generator 346 and a block turn-off device 349 . The connection interface 370 can be an USB interface, a RS232 interface or other interface.
[0046] The main steps of the power management method for a portable computer 320 according to a second embodiment of the invention is similar to those disclosed according to the flow chart of FIG. 2 , and are not described here for brevity, except for the step A.
[0047] FIG. 4 is a flowchart showing detailed steps in step A of FIG. 2 . The step A includes the following steps:
[0048] At step S 400 , start the process.
[0049] At step S 410 , if the power-saving signal or the power-saving event indicates the portable computer 320 needs to reduce the (operation) clock frequency, then step S 440 is performed to reduce the clock frequency, otherwise step S 420 is performed. Step S 440 reduces the system power consumption of the portable computer 320 by reducing the clock frequency.
[0050] At step S 420 , if the power-saving signal or the power-saving event indicates the portable computer 320 needs to reduce the reference voltage, then step S 450 is performed to reduce the reference voltage to a lower reference voltage, otherwise step S 430 is performed. Step S 450 reduces the system power consumption by reducing the reference voltage.
[0051] At step S 430 , if the power-saving signal or the power-saving event indicates the portable computer 320 needs to turn off the un-used circuit or block, then step S 460 is performed to turn off un-used circuit, otherwise step S 310 in FIG. 2 is performed. Step S 460 reduces the system power consumption by turning-off the un-used circuit.
[0052] In the other words, the present invention provides a power management method for managing power consumption of a portable computer having a battery and communicating with an access point (AP) through a wireless device connected to the portable computer via a USB interface. The USB interface at least has a first and second mode respectively with a first and second supporting rate less than the first supporting rate. The AP communicates with the wireless device with a first data rate. The portable computer works under a first clock frequency and a first reference voltage, wherein the portable computer includes a first circuit which is standby or suspends its function under power-saving mode, and the wireless device includes a second circuit which is standby or suspends its function under power-saving mode, the method comprises the steps of: (a) inputting a power-saving signal through an input device, such as a keyboard or button of the portable computer;
[0053] (b) detaching and re-attaching the wireless device to the portable computer from the first supporting rate to the second supporting rate; wherein, taking the USB interface as an example, the first USB supporting rate equals 480 Mbps (High speed) if the first USB mode is USB 2.0 standard, and wherein the first USB supporting rate equals 12 Mbps (Full speed) if the first USB mode is USB 1.1 standard.
[0054] (c) decreasing the first data rate to a second data rate between the AP and the wireless device, wherein the second date rate is less than the first data rate; wherein the second supporting rate is one selected from 480 Mbps, 12 Mbps and 1.5 Mbps, the second data rate is one selected from 54, 48, 36, 24, 18, 12, 9 and 6 Mbps for 802.11a standard, the second data rate is one selected from 11, 5.5, 2 and 1 Mbps for 802.11b standard, and the second data rate is one selected from 54, 48, 36, 24, 18, 12, 11, 9, 6, 5.5, 2 and 1 Mbps for 802.11g standard.
[0055] (d) reducing the first clock frequency of the portable computer to a second clock frequency, the second clock frequency is lower than the second clock frequency.
[0056] (e) reducing the first reference voltage to a second reference voltage, the second reference voltage is less than the first reference voltage.
[0057] (f) turning off the first circuit of the portable computer.
[0058] For the convenience in understanding the adjustment of the data rate in the present invention, the related data list for 802.11a/b/g and USB interface is shown in FIG. 5 .
[0059] As for the detailed implementation of the function blocks of the clock generator 348 , the reference voltage generator 346 , and power source detection means 326 of the FIG. 3 can be seen in the related arts, and is not described here.
[0060] US application number US2005/0138444A1, titled as “Frequency voltage mechanism for microprocessor power management”, discloses a power management technique which adjusts the clock frequency and the voltage of the microprocessor.
[0061] The input device 352 of FIG. 3 of the present invention can include a remote controller coupled to a wireless receiver, or the like.
[0062] U.S. Pat. No. 6,072,334, entitled “signal converter with a dynamically adjustable reference voltage and chipset including the same”, discloses a method of reducing power consumption of the chipset by adjusting reference voltage.
[0063] U.S. Pat. No. 6,034,508, entitled “Battery life extending power-switching device for all-time operational system”, discloses a switching method and apparatus of switching power sources from a battery or an external power source to an all-time circuit by means of a power source detection circuit to detect the power sources.
[0064] While the invention has been described by way of example and in terms of preferred embodiment, it is to be understood that the invention is not limited thereto. Those who are skilled in this technology can still make various alterations and modifications without departing from the scope and spirit of this invention. Therefore, the scope of the present invention shall be defined and protected by the following claims and their equivalents.
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The present invention relates to a power management method for portable computers with a wireless device and detects the electric power source of a portable computer through a power source detection circuit during the operation of portable computer. In addition, any one of the following is dynamically changed: the supporting rate of the connection interface between a wireless device and the portable computer, the data rate between the AP (Access Point) and the wireless device. Moreover, the invention provides a plurality of input methods for triggering the power saving modes of the portable computer to achieve the object of reducing power consumption.
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This invention was made in part with Government support under Grant CHE-8019947 awarded by the National Science Foundation. The Government has certain rights in this invention.
This is a continuation-in-part of Application Ser. No. 623,711, filed June 22, 1984, now U.S. Pat. No. 4,629,478.
BACKGROUND OF THE INVENTION
This invention relates to a monodisperse aerosol generator and interface structure for forming an aerosol beam and introducing it into mass spectrometry apparatus. The monodisperse aerosol generator has separate utility aside and apart from the interface structure inasmuch as it may be used as a primary aerosol standard for reference purpose, as a source of injection of uniform particles to internal combustion devices, and as a source of sample solution introduction in flame and plasma atomic spectrometry (e.g., atomic absorption, atomic emission and atomic fluorescence spectroscopy). The monodisperse aerosol generator is, however, primarily intended for use as a means of solution introduction to a device acting as an interface between a liquid chromatograph and a mass spectrometer, or for direct introduction of sample solutions to the interface without the use of the liquid chromatograph. The preferred interface structure according to this invention accepts the monodisperse aerosol and desolvates it to form a solute aerosol beam which, with high purity, is introduced into a mass spectrometer.
The device is intended to provide a source of aerosol particles with a narrow particle size distribution, with a high degree of efficiency. It will be capable of producing aerosol from a wide range of liquids of varying physical properties. These liquids will include water and solutions of substances soluble in water, organic solvents and solutions of substances soluble in organic solvents. The device will produce a stable aerosol, such that the aerosol, once formed, will show little tendency to coagulate to form agglomerates of particles. The aerosol will, however, be capable of controlled evaporation for partial or complete removal of solvent. The size of the aerosol droplets will be controllable by simple means.
The device will be capable of producing a uniform and reproducible concentration of droplets in the gas stream over an extended period of time. It will also be capable of generating droplets with a wide range of selected sizes, covering a range typically of 5-200 micrometers in diameter. Liquid chromatography, particularly modern high performance liquid chromatography, provides a powerful tool for the separation of complex mixtures of either organic or inorganic species into their components. It is suitable for a great range of compounds which cannot be separated using the technique of gas chromatography. Such compounds may be thermally unstable or involatile under normal gas chromatographic conditions. Many organic compounds of biological significance, and most ionic and inorganic compounds fall in this category.
Mass spectrometry is a very widely used technique for providing structural information about chemical species. Often, an unknown species may be identified with great certainty, by comparison of its mass spectrum with that of a reference mass spectrum obtained from a species of known composition. For reliable mass spectral identification of unknown species, it is generally necessary for the mass spectrometer to fulfill the following requirements: (1) mass spectra should be generated by the electron or atomic impact mode of ionization; and (2) mass spectra should be generated from one species only at a time.
Many molecules, especially biological molecules of higher molecular weight cannot be analyzed by mass spectrometry using either electron or chemical ionization techniques. To overcome this limitation, a fast atom bombardment (FAB) source is attached to the mass spectrometer to provide a stream of fast atoms for the ionization of higher molecular weight compounds.
In a liquid chromatograph, a stream of solvent, containing a mixture of chemical species in solution, is passed at elevated pressure through a chromatographic column. The column is so designed that it separates the mixture, by differential retention on the column, into its component species. The different species then emerge from the column as distinct bands in the solvent stream, separated in time. The liquid chromatograph provides, therefore, an ideal device for the introduction into a mass spectrometer of single species, separated from initially complex mixtures.
In order for the species emerging from the column to be introduced into a mass spectrometer, partial or total removal of solvent from the dissolved species is desirable. This serves the following purposes: (1) it allows the ionization chamber of the mass spectrometer to operate at normal operating pressures (e.g., 10 -5 to 10 -6 torr for electron impact ionization; 1 torr for chemical ionization; 10 -5 torr torr for atomic impact ionization); and (2) it allows normal ionization modes, such as electron or atomic impact, chemical or other to be used. Without efficient solvent removal from the species entering the ionization chamber of the mass spectrometer, hybrid and less well characterized mass spectra are produced. These types of mass spectra are generally of diminished value for unknown compound identification.
One purpose of the invention is to provide a means of introducing small samples of substances, dissolved in suitable solvent, directly into a mass spectrometer for either electron or atomic impact mass spectrometry. The interface must remove the solvent and its vapor to a sufficiently low level that either impact mode of operation may be used. The interface may be used either as a rapid means of directly introducing samples into a mass spectrometer, or as an interface between a liquid chromatograph and a mass spectrometer. It is intended that the interface should take advantage of the inherent capabilities of each component technique, without compromising either.
Specifically, preferred goals of the invention are: (1) to allow direct, simple interfacing between the liquid chromatograph and the mass spectrometer; (2) to provide efficient species transport between the liquid chromatograph and the mass spectrometer; (3) to allow the use of all normal modes of ionization typically used for gas chromatograph/mass spectrometry; (4) to allow operation with a wide variety of solvents (this would include solvents and solvent mixtures commonly used in normal, reversed phase and ion exchange liquid chromatography, e.g., alcohols, nitriles, and aqueous buffers, together with mixtures of same); (5) to produce sufficiently high species enrichment in the liquid chromatography effluent, by solvent removal, that the desolvated species may be introduced directly to the ionization chamber of a normal mass spectrometer, without need for additional high pumping capacity in the mass spectrometer; (6) to allow the device to be readily incorporated into the ionization chambers of existing instruments, with minimum modification (e.g., through the direct probe inlet); (7) to be capable of reliable, routine operation; (8) to be capable of providing precise, quantitative analysis of species over at least two orders of magnitude mass range.
Previous methods for generating uniform aerosols directly from liquid streams have worked on the principle of applying a regular external disturbance to a liquid cylindrical jet. The disturbance has been applied either axially or longitudinally to the jet as it emerges from a uniform circular nozzle. The disturbance has been provided by an electromechanical device, such as a piezoelectric crystal or a loudspeaker coil, driven by a high frequency power source.
The orifices used have either been laser-drilled steel or platinum disks, or fine bore stainless steel or glass capillary tubes. In general, the smallest droplets claimed for the devices are approximately 10 micrometers for circular disk orifices and 40 micrometers for capillary devices. A typical disk device is that of Berglund and Liu. l The liquid is passed under pressure through a disk orifice, emerging as a jet which is periodically disturbed by oscillations from a piezoelectric crystal. The piezoelectric crystal is driven at a selected frequency by a radiofrequency generator. Stable and uniform aerosol production is only possible over a restricted range of liquid flow and oscillating frequency, for each particular orifice size. The initial aerosol stream is dispersed by a concentric gas jet, diluted with further air and neutralized electrically with a radioactive source, before emerging from the device.
Capillary devices are typified by that of Lindblad and Schneider. 2 Here liquid emerges from a stainless capillary tube, is subjected to transverse disturbances from a piezoelectric crystal under radiofrequency oscillations, and breaks into a uniform droplet stream. In general, the droplet density produced by the capillary type devices is lower than that produced by the disk devices, and so dilution gas for prevention of agglomeration is not used.
Other devices typically used for aerosol production, and suitable for use with a wide range of solvents and solutions are pneumatic nebulizers and spinning disk nebulizers. Devices are also available which are based on ultrasonic aerosol production using focussed-beam devices.
A number of approaches to interfacing liquid chromatography with mass spectrometry have been attempted. They may be summarized under the following categories:
Direct Liquid Introduction (DLI). With this approach, the interface between the liquid chromatograph and the mass spectrometer consists of a direct probe, having a stainless steel diaphragm at the tip. The center of the diaphragm has a small (typically 1-10 micrometer) orifice, through which part of the column effluent is sampled into the ionization chamber of the mass spectrometer, through a desolvation chamber. A liquid stream emerges from the orifice, and shatters into droplets. The droplets pass into a desolvation chamber, which is cryogenically cooled in order to trap solvent vapor, and maintain a reasonable operating pressure in the ionization chamber. The system was first described by Baldwin and McLafferty, 3 and is marketed commercially by Hewlett-Packard and Ribermag. Versions have been described for both normal [1] and micro-column [2] liquid chromatography.
Mechanical Transfer Techniques. With mechanical transfer techniques, all of part of the effluent is collected onto a moving wire or belt. The liquid either flows directly onto the wire or belt, or is sprayed on as an aerosol. In either instance, a thin film of the liquid is formed, from which the solvent is evaporated in stages. The belt (or wire) passes through several independently pumped chambers, separated by vacuum locks, before reaching the ionization chamber of the mass spectrometer. In the first chamber, the belt is usually heated radiantly, in order to evaporate solvent from the column effluent. Prior to the ion source, the belt is heated rapidly, in order to flash vaporize the species from the belt, and allow it to pass into the ion source chamber. A typical system of this type is that of McFadden, 4 which is available commercially from Finningan Instruments. Another version (available commercially from (VG-Organic) passes the belt directly up into the ionization chamber, in order to allow surface ionization techniques to be used.
Aerosol Introduction Techniques. These derivatives of the DLI approach attempt to produce more efficient evaporation of solvent from the liquid chromatography column effluent, prior to its entering the ionization chamber of the mass spectrometer. The effluent emerges as a liquid jet from a small orifice, which is heated to a high temperature (typically 1000° C., using an oxyhydrogen flame). The partly desolvated aerosol particles are separated from the solvent vapor by means of a skimmer, before passing to the ionization chamber of the mass spectrometer. Such a device has been described by McAdams et al., 5 / and is available commercially from Finnigan Instruments.
In addition to the above, the following patents as submitted in copending U.S. Pat. application Ser. No. 775,035 are noted in that they relate generally to interface structure for use in a combined liquid chromatography - mass spectrometry system:
U.S. Pat. No. 4,055,987; McFadden; 11/01/77
U.S. Pat. No. 4,066,411; Fine et al.; 01/03/78
U.S. Pat. No. 4,112,297; Miyagi et al.; 09/05/78
U.S. Pat. No. 4,281,246; White et al.; 07/28/81
U.S. Pat. No. 4,298,795; Takeuchi; 11/03/81
U.S. Pat. No. 4,300,044; Iribarne et al.; 11/10/81
U.S. Pat. No. 4,403,147; Melera et al.; 09/06/83
U.S. Pat. No. 3,633,027; Rykage; 01/04/72
U.S. Pat. No. 3,997,298; McLafferty et al.; 12/14/76
U.S. Pat. No. 4,213,326; Brodasky; 07/22/80
U.S. Pat. No. 5 4,391,778; Andresen et al.; 07/05/83
No relevant prior art is known with relation to the monodisperse aerosol generator per se.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
FIG. 1 is a schematic view of the invention in use as an interface;
FIG. 2 is a sectional view through a monodisperse aerosol generator according to the invention;
FIG. 3 is a graph comparing monodisperse and polydisperse aerosols as referred to herein;
FIG. 4 illustrates columnar breakup (A) according to this invention in comparison to sinuous breakup (B) and atomization (C);
FIG. 5 is a schematic view of the invention in use as an interface showing a fast atom bombardment source.
FIG. 6 is a sectional view through a monodisperse aerosol generator according to an alternate embodiment of the invention showing a capillary tube nozzle tip.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates that form of the invention forming an interface for use in a combined liquid chromatography-mass spectrometry system or for direct injection into the mass spectrometer. The relatively pulseless pump 10 of the liquid chromatograph system pumps effluent eluted from the chromatograph column (not shown) into the line 11 in which an optional six port sample valve 12 may be interposed. In the combined system, sample injection is not used but provision may be necessary to reduce the flow through the outlet line 13 and, for this purpose, split flow may be adjusted with part of the effluent being directed over the line to waste or to suitable collection means. For direct injection, the pump 10 may pump only solvent in the line 11 and the sample may be introduced as by the syringe 15.
In any event, the solution is filtered at 16 before passing through the line 17 to the monodisperse aerosol generator 18. Although "monodisperse" implies a single aerosol droplet or particle size, that term is used herein to mean droplets or particles which have a very narrow range of sizes. The meaning should be clear from FIG. 3 wherein typical monodisperse aerosol within the meaning therein is compared with a polydisperse aerosol. The polydisperse aerosol illustrated in FIG. 3 was generated from a PerkinElmer crossed flow pneumatic nebulizer whereas the monodisperse aerosol was generated according to this invention using a 6 um orifice, as will be described presently. The measurements from which FIG. 3 was generated were of Fraunhofer diffraction from the aerosols generated.
As will be explained more fully hereinafter, the monodisperse aerosol is entrained in a high velocity gas jet emanating from the capillary 19 and is directed into the confined space 20 for the purpose of desolvation. The aerosol is suitably diluted with sheath gas entering from the line 21 in amount sufficient to maintain the desolvation chamber space 20 substantially at atmospheric pressure. The use of substantially atmospheric pressure in the chamber 20 greatly enhances the desolvation process and allows the monodisperse aerosol droplets or particles to the substantially completely depleted of the solvent so that by the time the aerosol reaches the outlet orifice 22 it is in the form of solvent-depleted solute.
The dispersion and sheath gases preferably are inert such as argon or helium from a suitable supply 23. Their rates of flow over the line 21 and to the capillary 19 may be adjusted by the respective flow regulators 24 and 25.
The chamber 20 may typically be 40 mm in diameter and approximately 30 cm long. The outlet tube 26 may be a 1/2 inch stainless steel tube provided with a suitable shut-off valve 27 to isolate the relatively high pressure chamber 20 from the vacuum region.
The vacuum region is shown as comprised of the two chambers 28 and 29 connected to the respective pump 30 and 31. Typically the pump 30 evacuates the chamber at a rate of about 300 liters per minute to maintain the chamber 28 at a pressure in the range of 2-10 torr whereas the pump 31 typically evacuates about 150 liters per minute to maintain the chamber 29 at a pressure in the range 0.1 to 1 torr.
The nozzle end 32 of the tube 26 is precisely aligned with the flat end 33 of the tube 34 forming the first skimmer. The separation between 33 and 34 typically may be about 1-3 cm. Similarly, the separation between the nozzle end 35 and the flat end 36 of the outlet tube 37 may be in the 1-3 cm range.
With the internal diameter of the nozzle 32 being 0.5 mm whereas the internal diameters of the two skimmers 33 and 36 and also of the nozzle 35 being 1.0 mm optimum results were obtained as were also obtained by using 0.5 mm inside diameters for all but the skimmer 33 whose inside diameter was 1.0 mm.
Operation of the System
1. Direct injection mode. In this mode of operation, a constant flow of solvent is supplied to the monodisperse aerosol generator 18 with the low-pulse liquid pump 10. The monodisperse generator produces a finely dispersed solvent aerosol which passes, together with the dispersion gas, into the desolvation chamber 20. In the desolvation chamber, the majority of the solvent evaporates. The combination of dispersion gas and solvent vapor then passes sequentially through the two pressure reduction chambers 28, 29 where the mixture of dispersion gas and solvent vapor is removed by the vacuum pumps 30, 31.
Samples are introduced to the system by means of an injector 15. The sample may be either a pure liquid, or consist of a solution of solid or liquid in a suitable solvent. The injector may be either a multi-port valve, a septum injection system, or a high performance liquid chromatography auto-injector system. Generally, a small sample volume (typically 5-100 microliters), is introduced, which might typically contain a few micrograms or nanograms of the substance to be analyzed. The aerosol generated by the monodisperse generator now passes through the desolvation chamber and the two pressure reduction chambers, as with the pure solvent stream. However, when sample is present in the solvent stream, a highly dispersed aerosol of sample material remains after solvent evaporation. This aerosol finally enters the ionization chamber of the mass spectrometer M, where ions are generated for subsequent mass analysis. Separation of aerosol and gas/vapor mixture is effective because the desolvated aerosol particles gain sufficient momentum in their transit through the skimmers of the interface so that they are largely unaffected by the pumping in the vacuum chambers.
2. HPLC coupled mode. Operation of the interface with a high performance liquid chomatograph is very similar to operation with the direct injection device described in the previous section. The only substantial difference is that the sample may now contain a mixture of compounds, which are separated into individual compounds by passage through a chromatography column. The chromatography column is placed between the injector valve and the aerosol generator. Mass spectrometers can generally only analyze one compound at a time and so the separation of complex mixtures into individual compounds is a pre-requisite for normal mass spectrometric analysis.
FIG. 2 illustrates the nebulizer or monodisperse aerosol generator according to this invention. As shown, the housing 40 is provided, having a glass ball joint 41 for connection to the desolvation chamber (FIG. 1), for containing the nebulizer. The nebulizer structure in FIG. 2 comprises the glass tip 42 seated in the top of the body 43 through the intermediary of a suitable sealing gasket or O-ring 44 and held in place by the cap 45 threaded onto the body 43 as shown. Immediately below the cap 45 is the sheath gas distributing housing 46 to which the line 21 is connected and the body 43 has a central passage leading to the split flow control valve 47 having the outlet 48. The solution is pumped through the line 17 previously described and causes same to issue as a stable jet from the tip of the nozzle 42.
Although the diameter of the nozzle orifice may range between about 2 to about 100 micrometers, the range of about 9 to about 20 micrometers is preferred for nozzle 42. The stable jet is controlled as to its velocity so that it is subjected to the columnar breakup as indicated in FIG. 4 at A. Progressively higher velocities are depicted at B and C which respectively illustrate sinuous breakup and atomization.
The columnar or monodisperse breakup of A is Rayleigh breakup and produces droplets or particles D of substantially uniform size and spacing, the droplet diameters being about two times the orifice diameter. Generally speaking, with the preferred orifice diameters, the stable jets with Rayleigh breakup were produced with flow rates below about 1 mL/min.
The glass nebulizer tip in FIG. 2 is constructed from thick-walled glass capillary tubing of approximately 0.25 inches external diameter. One end of the tube is initially flame sealed, to give a conical closure to the tube. This end is then opened, by grinding with a fine abrasive medium (such as 400 grade silicon carbide paper), until an orifice of suitable diameter has been created. The diameter of the orifice may be measured using a calibrated microscope. The other end of the tube is formed into a lip, which is ground on its lower edge to form a liquid-tight seal against the gasket placed in the threaded end of the metal block. The nebulizer tip is held in place with the retaining cap.
FIG. 6 illustrates an alternate embodiment of the monodisperse aerosol generator wherein the nebulizer tip is a cylindrical capillary tube 142 which is seated in sample line 117. Capillary tube 142 may be constructed of metal, glass, silica or any other suitable sturdy material capable of being manufactured to the appropriate size of approximately 25 micrometers internal diameter. Capillary tube 142 extends downwardly into sample line 117 for a distance of about 4 mm and is secured in place by compression fitting 150.
Compression fittings are commercially available from several manufacturers. The compression fitting 150, illustrated in FIG. 6, is made by Valco and comprises essentially a central externally threaded cylinder 151, which is fitted with internally threaded upper and lower caps 152 and 153, respectively. Upper ferrule 154 and lower ferrule 155 are constructed of a high temperature plastic and are deformable to the extent that, as upper cap 152 and lower cap 153 are screwed into place onto cylinder 151, upper ferrule 154 compresses tightly against capillary tube 142 and lower ferrule 155 compresses tightly against the sample line 117. Upper ferrule 154 also functions as a seal because sample line 117 has an internal diameter of approximately 250 micrometers, which is considerably larger than the external diameter of capillary tube 142. Body 143 is adapted to provide a tight seal with compression fitting 150 by the placement of a set of O rings 144 between body 143 and upper and lower caps, 152 and 153.
The capillary tube nozzle tip 142, as illustrated in FIG. 6, has a preferred orifice diameter of approximately 25 micrometers, which is slightly larger than that of the conical nozzle tip 42 illustrated in FIG. 2. Several advantages are derived by incorporating the nozzle tip 142, as shown in FIG. 6, into the aerosol generating device. For example, the in-line filter system 16, illustrated in FIG. 1, can be eliminated because capillary nozzle tip 142 is not as prone to blockage as conical tip 42. Also, the improved sample flow eliminates the need for a sheath gas and a split flow outlet. Therefore, the construction of the generator can be simplified by eliminating sheath gas line 21, sheath gas housing 46, split flow control valve 47, and outlet 48. The dispersion gas entering through line 19 has been found to be sufficient for the desolvation step and to maintain the chamber space 20 substantially at atmospheric pressure. Line 19 dispersion gas is also sufficient to carry the aerosol droplets to outlet orifice 22 and through outlet tube 26 into evacuation chambers 28 and 29 (FIGS. 1 and 5).
The liquid supply to both embodiments comes from a pump, capable of sustaining liquid flows in the range of 0.01 to 1.0 mL/min., at pressures up to approximately 300 pounds per square inch. The pump should also provide little pressure pulsation in operation. A typical pump used is one suitable for High Performance Liquid Chromatography.
Dispersion gas is introduced from a capillary tube, constructed from stainless steel or some other suitable rigid material. The dispersion gas tube is positioned with suitable alignment devices, to be fixed at between 3 and 10 mm above the tip of the glass orifice. Dispersion gas, controlled by suitable means such as pressure controllers, needle valves, and rotameters, flows through the dispersion gas capillary at a flow adequate to produce efficient dispersion of the aerosol. Flows will typically be in the range of 0.5 to 2.0 L/min. of gas.
The aerosol produced by the device may be sampled by any appropriate means, or pass into a desolvation chamber or sampling port of another device by sealing the aerosol generation device into a closed chamber. This first chamber may then be sealed to subsequent devices, to ensure efficient transfer of the aerosol to these devices.
FIG. 5 shows the monodisperse aerosol generator with FAB source F attached to mass spectrometer M. The generation of FAB spectra also requires that the sample be present in pure form. Small micrometer particles, free of solvent matrix are ideal for the production of FAB mass spectra.
The primary differences between this device and previous devices, and the advantages resulting from these, are the following:
(1) No source of external mechanical distrubance is needed for the operation of the device.
(2) The orifice may be either capillary tubing or readily constructed therefrom, to produce highly circular openings of 2 micrometers diameter and above.
(3) The diameter of the aerosol produced by the device is controlled by the diameter of the liquid orifice. The aerosol particle diameter is approximately 2.1× the orifice diameter. The precise relationship between aerosol diameter and orifice diameter is dependent on the compressibility of the liquid.
(4) The selection of aerosol diameter, by interchange of orifices, may be accomplished readily and rapidly.
(5) The device operates very stably over extended periods of time without the need for adjustment.
(6) The device operates very reproducibly from day to day, without the need for realignment of components, or the re-optimization of parameters, between runs.
(7) A wide variety of liquids may be used with the device, requiring only that the contents of the liquid reservoir be changed in order to change the liquid to be converted to an aerosol. Both water, organic solvents, mixtures of water and organic solvents, and mixtures of organic solvents may be used with the device.
(8) Inorganic and organic species may be dissolved in any of the solvents or solvent mixtures mentioned in item (7) at concentrations up to 1% by weight of dissolved solids, without blockage problems occurring in the device.
(9) The FAB source permits atomic impact ionization of high molecular weight compounds for the generation of mass spectra. The combination of electron impact spectra for the low molecular weight compounds, together with the FAB spectra for the higher molecular weight compounds, provides the mass spectroscopist with the ability to analyze the entire range of compounds likely to be of interest.
It will be appreciated that to prevent degradation of the monodisperse aerosol generation due to coagulation and/or impact between droplets, the dispersion must be effected near the point of random or Rayleigh breakup, by dispersing the aerosol at an angle, preferably about 90°, to the axis of the stable jet. It will also be appreciated that the vacuum means continuously evacuates gaseous medium solvent vapor and solvent-depleted solute, while separating off the solvent vapor and gaseous medium to form the monodisperse aerosol beam of solvent-depleted solute. This beam has high momentum and passes through the final skimmer into the ion source. It should also be understood that the solvent-depleted solute beam consists of particles of smaller size than those of the originally generated aerosol and contains a somewhat greater relative size range of distribution.
It should also be noted that this invention serves two very distinct purposes: (1) as a novel source of monodispersed particles, which would have potential applications in the area of aerosol calibration and particle generation, and (2) the interface between a flowing liquid stream and a low pressure mass spectrometer. Although the interface contains the aerosol generator, the combination of physical processes to remove solvent from the droplets and enrich the solute particles is also critical for the performance of the interface.
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A monodisperse aerosol generator forms a stable jet of liquid at a velocity allowing columnar breakup into droplets of uniform size and spacing. To prevent degradation of the monodisperse aerosol, it is dispersed by entrainment in a high velocity gaseous stream. To provide an interface for direct injection into a mass spectrometer or to interface a liquid chromatograph with a mass spectrometer, the generator is followed by a desolvation chamber operating at about atmospheric pressure and a multistage pressure reducer which evacuates solvent vapor and gaseous medium to form a high momentum, solvent-depleted solute aerosol beam which is input into the mass spectrometer. To permit the analysis of higher molecular weight molecules that may be either involatile or thermal sensitive, a fast atom bombardment (FAB) source is used for the production of FAB mass spectra.
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FIELD OF THE INVENTION
[0001] The present invention relates to a process for preparing raloxifene and in particular high purity raloxifene hydrochloride with high yields.
STATE OF THE ART
[0002] Raloxifene and in particular the relating hydrochloride salt, characterised by the following formula (I):
is an active principle used in the treatment of osteoporosis and was described for the first time in European patent application EP62503. In this prior patent various preparation methods are described which generally involve the following stages:
1) protection of the 2 hydroxylic functions of 6-hydroxy-2-(4-hydroxyphenyl)benzo[b]thiophene according to the following reaction scheme
where R 5 is an alkyl, cycloalkyl or COR 6 acyl group, a SO 2 R 6 sulfonyl group where R 6 is a primary or secondary C 1 -C 4 alkyl, C 1 -C 3 fluoro alkyl or C 1 -C 4 alkoxyphenyl,
2) acylation of the compound protected with 4-(2-piperidinoethoxy)benzoyl halide according to the following synthesis scheme:
in which R 7 is a halogen atom,
3) deprotection or elimination of the OR 5 protective group.
[0003] As it results from the examples reported in EP62503, when the reaction is conducted using the acetyloxy group as OR 5 protective group, deprotection of this group is conducted first with sodium hydroxide in an alcoholic solution and subsequently with methanesulfonic acid. This type of hydrolysis however does not allow high purity raloxifene to be obtained, since, as indicated by example 6, the product to be purified must be passed through a chromatographic column. This type of treatment, however, only enables a yellow foam to be obtained, and, to arrive at a product of solid crystalline form, a further treatment with acetone is required. The crystallized product thus obtained consisting of raloxifene methanesulfonate must be further converted into the corresponding hydrochloride for pharmaceutical use.
[0004] The aforesaid process, requiring product passage through a chromatographic column, is not achievable at industrial level, proof of which being that in the same prior patent, instead of the aforesaid synthesis scheme, the one preferred is that in which the OR 5 protective group is an alkoxy, specifically a methoxy group, which for unblocking requires the use of aluminium trichloride and a thioderivative and preferably methanethiol, moreover in a quantity greatly in excess of the substrate on which the deprotection must be conducted, with considerable pollution problems, which evidently involves the use of considerable quantities of thioderivatives.
[0005] The processes described in EP62503 involve another inconvenience caused by the use of aluminium trichloride and, if proceeding to the scheme preferred by this prior patent, this Lewis acid must be used in substantial quantities, since it is used not only in stage (2) of acylation, but also in subsequent dealkylation. Aluminium trichloride as shown in the subsequent patent U.S. Pat. No. 5,629,425 produces a large quantity of aluminium-based by-products which are soluble in raloxifene processing solvents and are found therefore in the final product.
[0006] To overcome these problems, in the aforestated U.S. Pat. No. 5,629,425 boron trichloride or boron tribromide is used as Lewis acid, these being decidedly more expensive catalysts than aluminium trichloride.
[0007] The need was felt to provide a process which enabled raloxifene hydrochloride to be prepared with high yields and high purity and low aluminium content without using expensive catalysts.
SUMMARY OF THE INVENTION
[0008] The applicant has surprisingly found a process capable of overcoming the drawbacks of known processes and which allows raloxifene and in particular raloxifene hydrochloride to be obtained with high purity and high yields.
[0009] This process comprises in particular the following stages:
a) demethylation of 6-methoxy-2-(4-methoxyphenyl)benzo[b]thiophene of formula (II)
in pyridine hydrochloride to obtain 6-hydroxy-2-(4-hydroxyphenyl)benzo[b]thiophene of formula (III)
b) acetylation of 6-hydroxy-2-(4-hydroxyphenyl)benzo[b]thiophene with an acetylating agent to obtain the corresponding 6-acetoxy-2-(4-acetoxyphenyl)benzo[b]thiophene of formula (IV)
c) acylation of 6-acetoxy-2-(4-acetoxyphenyl)benzo[b]thiophene (IV) with 4-(2-piperidinoethoxy)benzoylchloride hydrochloride of formula (V)
with aluminium trichloride in halogenated solvent to obtain 6-acetoxy-2-(4 acetoxyphenyl)-3-[4-(2-piperidinoethoxy)benzoyl]-benzo[b]thiophene of formula (VI)
d) hydrolysis of 6-acetoxy-2-(4-acetoxyphenyl)-3-[4-(2-piperidinoethoxy)benzoyl]-benzo[b]thiophene, according to the following operative methods:
d1) treatment of 6-acetoxy-2-(4-acetoxyphenyl)-3-[4-(2-piperidinoethoxy)benzoyl]-benzo[b]thiophene with alkaline hydroxide in alcohol solvent,
d2) acidification of the product obtained in the previous stage (d1) with a strong acid, to obtain the corresponding raloxifene salt with strong acid, characterised in that the strong acid used in stage (d2) is concentrated hydrochloric acid.
[0010] In this respect, by conducting the hydrolysis of 6-acetoxy-2-(4-acetoxyphenyl)-3-[4-(2-piperidinoethoxy)benzoyl]-benzo[b]thiophene with sodium hydroxide and subsequently treating the product obtained with hydrochloric acid in place of methanesulfonic acid, raloxifene hydrochloride precipitates in crystalline form directly with a high purity equal to 98%, thus in contrast to the analogous process described in EP65203 conducted with methanesulfonic acid, without having to use purification processes such as passage through a chromatographic column, which are impractical from the industrial point of view. In addition the product derived from stage (d2) has a low aluminium content.
DETAILED DESCRIPTION OF THE INVENTION
[0011] The 6-methoxy-2-(4-methoxyphenyl)benzo[b]thiophene of formula (II) used in stage (a) of the process of the present invention is prepared by reacting 3-methoxybenzene-thiol with α-bromo-4-methoxyacetophenone to obtain the corresponding α-(3-methoxyphenylthio)-4-methoxyacetophenone which is finally cyclizised to obtain the intermediate (II) with polyphosphoric acid, as in the following scheme.
[0012] The pyridine hydrochloride used in stage (a) is preferably prepared in situ by adding concentrated hydrochloric acid to pyridine and distilling off all the water to obtain a thick but stirrable residue. The applicant has also surprisingly found that if the demethylation reaction or stage (a) of the process of the present invention is conducted in the presence not only of pyridine hydrochloride but also of tributylamine, preferably in weight ratios with respect to 6-methoxy-2-(4-methoxyphenyl)benzo[b]thiophene (II) of between 0.5 and 2, it is possible to lower the reaction temperature which in prior art is conducted at 210° C., to decidedly lower temperatures, between 170 and 180° C.
[0013] According to a preferred embodiment of the process of the present invention, it is not necessary to isolate the 6-hydroxy-2-(4-hydroxyphenyl)benzo[b]thiophene (III) obtained in stage (a).
[0014] In stage (b) according to a preferred embodiment acetic anhydride is used as acetylating agent and a tertiary aliphatic amine, preferably triethylamine, is used as hydrogen ion acceptor. The solvent used in stage (a) is an aprotic polar solvent, ethyl acetate being particularly preferred.
[0015] The 4-(2-piperidinoethoxy)benzoylchloride hydrochloride of formula (V) used in stage (c) is preferably prepared in situ by a conventional type procedure by reacting 4-(2-piperidinoethoxy)-benzoic acid hydrochloride with thionyl chloride without isolating the reaction product. This reaction is preferably conducted in methylene chloride in the presence of pyridine as catalyst.
[0016] Stage (c) is preferably conducted in methylene chloride, according to a particularly preferred embodiment this stage being conducted in the following manner: 6-acetoxy-2-(4-acetoxyphenyl)benzo[b]thiophene is added to 4-(2-piperidinoethoxy)benzoylchloride hydrochloride of formula (V) prepared in situ while still in its reaction solvent methylene chloride, the mixture thus obtained being poured onto a mixture consisting of methylene chloride and aluminium trichloride.
[0017] According to a preferred embodiment of the process of the present invention, 6-acetoxy-2-(4-acetoxyphenyl)-3-[4-(2-piperidinoethoxy)benzoyl]-benzo[b]thiophene (VI) is not isolated but is used in crude form for the subsequent hydrolysis (d).
[0018] Stage (d1) is preferably conducted using methanol as the alcoholic solvent, with excess 30% sodium hydroxide.
[0019] Stage (d2) is preferably conducted directly on the reaction mixture derived from stage (d1) to which equal weight quantities of water and ethyl acetate are added and finally 37% concentrated hydrochloric acid.
[0020] A suspension is hence obtained, which is preferably washed with equal weight quantities of water and ethyl acetate.
[0021] By the process of the present invention raloxifene hydrochloride is obtained with high purity and high yields of about 65-70% calculated on the 6-methoxy-2-(4-methoxyphenyl)benzo[b]thiophene (II).
[0022] The applicant has also found that if raloxifene hydrochloride obtained by the process of the present invention is crystallised from an alcoholic solvent, preferably methanol, possibly in the presence of small quantities of HCl, it achieves a purity of greater than 99%.
[0023] Finally the applicant has also found that by conducting a further crystallization, again from an alcoholic solvent, preferably methanol, possibly in the presence of HCl, on the product derived from the first crystallisation, raloxifene hydrochloride can be obtained with a purity greater than 99.7%. In particular raloxifene hydrochloride obtained after the first and/or the second crystallisation contains the characteristic impurity consisting of raloxifene hydrochloride N-oxide in a quantity less than 0.05% and preferably less than 0.01%, this product also having an aluminium content less than 5 ppm.
[0024] The product thus obtained has a particle size distribution (after gentle grinding conducted with the aim of simply homogenising the product) such that D(0.9) is ≦100 μm and D(0.5)≧40 μm. By further sieving a raloxifene hydrochloride is obtained with the following particle size distribution: D(0.9) between 50 and 65 μm and D[4.3]≧20 μm.
[0025] Some illustrative but non-limiting examples of the preparation process for raloxifene hydrochloride of the present invention and its relative intermediates are given.
EXAMPLE 1
Preparation of 6-acetoxy-2-(4-acetoxyphenyl)benzo[b]thiophene (IV)
[0026] 24 kg of pyridine (0.303 kmol) and 28.8 kg of 37% hydrochloric acid (0.292 kmol) are fed into a reactor. The reactor is placed under vacuum and all the water is distilled off until a thick but stirrable residue is obtained.
[0027] The residue is then redissolved in 6 kg of tributylamine and 6 kg of 6-methoxy-2-(4-methoxyphenyl)benzo[b]thiophene (0.022 kmol). The mixture is heated to 170-180° C. and is maintained at this temperature for some hours. It is then cooled to 50-60° C. and 24 kg of ethyl acetate and 60 kg of deionised water are fed into the reactor. The mixture is stirred for 15 minutes and the phases are separated. The solvent is distilled off from the organic phase under vacuum and the residue is redissolved with 24 kg of ethyl acetate and 5.3 kg of triethylamine (0.052 kmol). The mixture obtained is heated to 60-65° C. while being stirred and 8.9 kg of acetic anhydride (0.087 kmol) are added. The reaction mixture is stirred for 1 hour at the same temperature then is cooled to 25-30° C. and 24 kg of deionised water are added. The suspension is centrifuged, washed with 6 kg of deionised water and 6 kg of ethyl acetate.
[0028] The product is then dried at 50-60° C. and about 6.6 kg of dried product are obtained. The reaction yield is 91.1%.
EXAMPLE 2
[0000] Preparation of Crude Raloxifene Hydrochloride.
[0000] PHASE A
[0029] 42 kg of methylene chloride and 7.8 kg of 4-(2-piperidinoethoxy)-benzoic acid hydrochloride (0.027 kmol), 0.12 kg pyridine (0.0015 kmol) are fed into a reactor and heated under reflux and then 3.96 kg of thionyl chloride (0.033 kmol) are added. The mixture is stirred for 1 hour then about 20 litres of methylene chloride are distilled off. The mixture is cooled to 20-30° C. and 6 kg of 6-acetoxy-2-(4-acetoxyphenyl)benzo[b]thiophene (IV) (0.018 kmol) are added.
[0030] The mixture is stirred until is completely homogenised.
[0000] PHASE B
[0031] 36 kg of methylene chloride and 16.8 kg of aluminium trichloride (0.126 kmol) are fed into a reactor.
[0032] While stirring, the chloromethylene suspension, comprised of phase A prepared as described above, is added at 15-30° C. The mixture is stirred for 1 hour then the entire reaction mixture is poured into a reactor containing 60 kg of ice.
[0033] The mixture is stirred at 15-30° C. then the suspension is centrifuged, washing with 3 kg of methylene chloride and 3 kg of deionised water.
[0034] The centrifuged mother liquors, containing the product, are fed into a reactor and the phases are separated. The organic phase is distilled off until obtaining an oily residue and 15 kg of methyl alcohol are added, stirred at 20-40° C. and, maintaining the same temperature, 9.1 kg of 30% sodium hydroxide (0.068 kmol) are poured in. The mixture is stirred for 1 hour and 30 kg of deionised water and 30 kg of ethyl acetate are added.
[0035] At the same temperature 7.2 kg of 37% hydrochloric acid (0.073 kmol) are then added. The suspension is centrifuged, washing with 6 kg of ethyl acetate and 6 kg of deionised water. At the end 6.6 kg of dried product with HPLC purity>98% and low aluminium content are obtained. The reaction yield calculated on the 6-acetoxy-2-(4-acetoxyphenyl)benzo[b]thiophene (IV) is equal to a yield of 70.4%.
EXAMPLE 3
[0000] Crystallisation of Crude Raloxifene Hydrochloride (1 st Crystallisation of Crude Raloxifene Hydrochloride)
[0036] 6 kg of deionised water, 6 kg of crude raloxifene hydrochloride prepared as described in example 2 and 107 kg of methyl alcohol are fed into a reactor. The reaction mixture is heated until a complete solution is obtained then 0.25 kg of decolourising carbon are added. It is stirred for 15 minutes and then the suspension is filtered. While maintaining the solution stirred, 67 kg of methyl alcohol are distilled off. The residue is cooled and 0.1 kg of 37% hydrochloric acid are added. The pH, which must not exceed 2, is checked and the reaction mixture is then stirred for 2 hours at 20-40° C. The suspension is centrifuged, washing with 6 kg of methyl alcohol. 4.5 kg of dried product are obtained with HPLC purity of >99% and a yield of 75%.
EXAMPLE 4
[0000] Crystallisation of Crystalline Raloxifene (2 nd Crystallisation).
[0037] 0.9 kg of deionised water, 81 kg of methanol and the entire amount of crystallised product as described in example 3 are fed into a reactor. While maintaining the reaction mixture under stirring it is heated under reflux and 36 kg of methyl alcohol are distilled off. It is then cooled to 20-40° C. and 0.08 kg of 37% hydrochloric acid are added. The suspension is centrifuged, washing with 4 kg of methyl alcohol. The product is dried at 70° C. 4 kg of raloxifene hydrochloride are obtained with HPLC purity>99.8%, reaction yield 89%, in particular the raloxifene hydrochloride N-oxide content is less than 0.01% and aluminium content is less than 5 ppm. In particular the raloxifene hydrochloride obtained after crystallisation contains the characteristic impurity consisting of raloxifene hydrochloride N-oxide in a quantity less than 0.05% and preferably less than 0.01%. The product thus obtained has a particle size distribution (after gentle grinding conducted with the aim of simply homogenising the product) such that D(0.9) is ≦100 μm and D (0.5)≧40 μm.
[0038] By further sieving a raloxifene hydrochloride is obtained with the following particle size distribution: D(0.9) between 50 and 65 μm and D[4.3]≧20 μm.
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Process for preparing raloxifene hydrochloride with a purity greater than 98% and low aluminium content comprising the following stages a) demethylation of 6-methoxy-2-(4-methoxyphenyl)benzo[b]thiophene in pyridine and hydrochloric acid to obtain 6-hydroxy2-(4-hydroxyphenyl)benzo[b]thiophene in pyridine hydrochloride, b) acetylation of 6-hydroxy-2-(4hydroxyphonyl)benzo[b]thiophene with an acetylating agent to obtain the corresponding 6-acetoxy-2-(4 acetoxyphenyl)benzo[b]thiophene, c) acylation of 6-acetoxy-2-(4-acetoxyphonyl)benzo[b]thiophene with 4-(2 piperidinoethoxy)benzoylchloride hydrochloride with aluminium trichloride in halogenated solvent to obtain 6-acetoxy-2-(4acetoxyphenyl)-3-[4-(2 piperidinoethoxy)benzoyl]-benzo[b]thiophene, d) hydrolysis of 6-acetoxy-2-(4-acetoxyphenyl)-3-[4-(2-piperidinoethoxy)benzoyll benzo[b]thiophene according to the following operating conditions: d1) treatment of 6-acetoxy-2-(4-acetoxyphonyl)-3-[4-(2-piperidinoethoxy)benzoyl]benzo[b]thiophene with alkaline hydroxide in alcohol solvent, d2) acidification of the product obtained in the preceding stage (d1) with a strong acid, to obtain the corresponding raloxifene salt with the strong acid, characterised in that the strong acid used in stage (d2) is concentrated hydrochloric acid.
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BACKGROUND OF THE INVENTION
[0001] Tomatoes which yield juice having high viscosity are valued for production of tomato sauces. Unfortunately, tomatoes used commercially today tend to yield juices having less than optimal viscosity. In general, as ripening of tomatoes progresses, the viscosity of resulting juices decreases. The ripening inhibitor gene (rin) is a semi-dominant gene which was first described in 1968 by Robinson and Tomes, “Ripening Inhibitor: A Gene with Multiple Effects on Ripening.” Rpt. Tomato Genetics Cooperative 18:36-37. Tissue softening and pigment synthesis which occur in normal tomato fruits are inhibited in fruits of rin tomato mutants.
[0002] Heterozygous rin tomato fruit ripen more slowly than normal fruit, are firmer and have less polygalacturonase (PG) activity than non-rin fruit. Carotenoid accumulation is delayed and somewhat reduced in the heterozygous rin fruit, as reported by Buescher, et al. 1976, “Softening, Pectolytic Activity and Storage-life of rin and nor Tomato Hybrids,” Hort Sci. 11:603-604. See also Murray et al. 1995. “Evaluation of transgenic tomato fruit with reduced polygalacturonase activity in combination with the rin mutation.” Postharvest Biology and Technol, 6:91-101.
[0003] Tomatoes having the rin gene in the heterozygous condition have been sold as fresh tomatoes and used as processing tomatoes. However, while heterozygous rin tomatoes are firmer, the viscosity of the juice prepared from heterozygous rin tomatoes is still less than optimal; although use of rin heterozygotes can result in small increases in serum viscosity and lower Bostwick thickness values in cold break processing, heterozygous rin fruit do not differ from non-rin tomatoes in Bostwick thickness or serum viscosity when processed by hot break methods.
[0004] Davies et al. 1981, “The Constituents of Tomato Fruit—The Influence of Environment, Nutrition and Gene Type,” CRC Critical Reviews in Food Science and Nutrition, 15:205-280, indicates that the deleterious effects of ripening inhibitor genes in the heterozygous state may possibly be overcome by incorporating genes which will enhance color, such as high pigment and crimson.
[0005] Old gold crimson, a color enhancing gene, was first described in 1962 (Butler, L. R. and Tomes, M. L., 1962, “Crimson, a new fruit color,” Tomato Genet. Coop. Rpt. 12:17-18) and was determined by Thompson et al. (“Characterization of crimson tomato fruit color,” 1965, Proc. Amer. Soc. Hort. Sci. 86:610-616) to be a single recessive gene.
[0006] Fruits homozygous for rin are known, but it is also known that the normal ripening processes such as chlorophyll degradation, carotenoid biosyntheses, increased respiration, increased ethylene production and PG activity are nearly inhibited. Tigchelaar et al. 1978. “Genetic Regulation of Tomato Fruit Ripening.” Hort Sci. 13:508-513, Della Penna et al. 1987. “Polygalacturonase Gene Expression in Rutger, rin, nor Nr. Tomato Fruits.” Plant Physiol. 85:502-507.” According to Tigchelaar et al., the color of mutant rin is generally unacceptable for traditional fresh or processed use (p. 512). And Buescner et al. state that since no method has been discovered which will adequately ripen rin or nor tomatoes, the mutants are presently only suitable for processed green tomato products.
[0007] Fruits heterozygous in both rin and in nor are known, e.g. from Kopelovitch et al., “The Potential of Ripening Mutants For Extending The Storage Life of the Tomato Fruit,” Euphytica 28 (1979), 99-104. They disclose that in plants heterozygous for rin and nor, softening of fruit and carotenogenesis proceed at a rate intermediate between the normal and the mutant parents.
[0008] Kopelovitch et al. produced various homozygotes and F1 heterozygotes and reported that none of the homozygous ripening mutants developed normal or even pale-red pigmentation whereas in all heterozygotes between ripening mutants and high-pigment, a red, pale red or pink color had developed when the fruits were picked ripe. Fruit of the F1 hybrid between rin and nor developed a pale red color said to be acceptable for marketing. Fruit homozygous for rin or nor showed extremely long shelf life and the F1 (rin×nor) also exhibited excellent keeping ability. Among F1 crosses with hp. the most promising was said to be the one with nor.
[0009] Tigechelaar et al., “Natural and Ethephon-Stimulated Ripening of F1 Hybrids of the Ripening Inhibitor (rin) and Non-ripening (nor) Mutants of Tomato ( Lycopersicon esculentum Mill.) Aust. J. Plant Physiol., 1978, 5, 449-456, discloses ripening experiments with rin and nor hybrids.
[0010] Nahum U.S. Pat. No. 4,843,186 discloses a heterozygous tomato plant, heterozygous in rin, which is said to develop a full red color.
[0011] It is believed that tomatoes homozygous in rin and including one or more color enhancing genes are used commercially, but only to make heterozygous rin tomatoes, rather than for making paste.
SUMMARY OF THE INVENTION
[0012] The present invention is directed to the discovery that, contrary to expectations, homozygous rin tomatoes can be successfully used to prepare an acceptable paste or a sauce, e.g., a red pasta sauce. As a result of the present invention, it is possible to take advantage of the outstanding paste and serum viscosity of tomatoes which are homozygous in the rin genes without sacrificing desirable tomato color characteristics which are of importance to consumers. Also, the paste and serum of the tomatoes enjoy excellent resistance to syneresis. It is likewise believed that homozygous nor tomatoes or heterozygous rin/nor tomatoes can be advantageously used in the present invention,
[0013] Preferably tomato pastes according to the invention have at 12 Brix Bostwick thickness values in the range of from 0-3 cm, preferably from 0-2 cm. Likewise preferred tomato pastes according to the invention enjoy at 12 Brix syneresis levels of less than 4 mm, preferably less than 3 mm. This is in contrast to Bostwick values of 4.5-7 cm and syneresis values of 13-25 mm for, e.g., the known BOS 3155 variety.
[0014] In a first aspect, the invention pertains to a paste comprising tomatoes which are homozygous in the rin and/or nor genes or heterozygous in both the rin and nor genes. The most preferred pastes include tomatoes which are homozygous in rin and/or nor. In a still more preferred additional aspect of the invention, the paste is prepared by using tomatoes which are homozygous in the rin and/or nor genes or heterozygous in both rin and nor and which in addition comprise color enhancing genes such as old gold crimson (og c ), high pigment (hp), dark green (dg), intense pigment (Ip), as well as color enhancing transgenic genes.
[0015] The invention makes possible tomato paste having both good color and outstanding thickness, without requiring the mixing of different types of tomatoes. Preferably USDA paste color scores at 8.5 Brix for pastes of the invention range from 35 to 50, especially greater than 42.
[0016] We have found that it is possible to produce a tomato having both homozygous rin and the old gold crimson genes, wherein the tomato color is good, yet at the same time tomato fruit firmness and juice and paste viscosity are excellent as a result of the ripening inhibiting effect of the rin gene. In addition to pastes, the invention pertains to juices and sauces made from homozygous rin and/or nor tomatoes, or from tomatoes heterozygous in rin and nor, and, preferably to pastes, juices and sauces made from tomatoes which are homozygous in rin and/or nor, or heterozygous in rin and nor, and which include color enhancing genes, as well. Preferably, the invention concerns pastes, juices and sauces made from populations or assemblages of the above fruits having an average of at least 25% by weight, and preferably at least 50%, more preferably at least 90% of the tomatoes with the above-described genes.
[0017] In addition to using homozygous rin and/or nor genes, the invention encompasses the use of tomatoes which are heterozygous in the rin gene and heterozygous in the nor gene. Also, the homozygous rin or nor genes may be combined with additional rin or nor genes, e.g. to produce a tomato which is homozygous in rin and homozygous in nor or homozygous in either rin or nor and heterozygous in the other.
[0018] The pastes of the invention preferably include at least 50% by weight of the homozygous rin and/or nor tomatoes, or of the heterozygous rin/nor tomatoes, especially from 50 to 100% by weight. The juices of the invention preferably include at least 20% by weight of the homozygous rin or nor tomatoes, especially from 20 to 40% by weight.
[0019] Preferably, the tomatoes used in the invention are homozygous in the color enhancing gene such as og c , as well as the rin and/or nor gene.
[0020] Use of the homozygous rin tomatoes is particularly beneficial in view of their unique qualities, such as extremely high viscosity, almost no syneresis, high molecular weight polymers and large pectin chains. To our knowledge, these advantages are not achieved with tomatoes or tomato pastes outside of our invention. A secondary benefit is that as a result of such characteristics, less paste can be used in preparing a sauce. Similar advantageous are anticipated for homozygous nor and for heterozygous rin/nor tomatoes. The advantageous paste characteristics according to the invention can be expected to translate to improved, consumer perceivable sauce characteristics, such as improved mouthfeel and texture and to lead to a more full-bodied sauce.
[0021] For a more complete understanding of the above and other features and advantages of the invention, reference should be made to the following detailed description of preferred embodiments and to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] [0022]FIG. 1 is a graph of total solids vs. °Brix for the RIN (rinrin) tomato paste according to the invention and for tomato paste made from commercially available BOS 3155 tomatoes.
[0023] [0023]FIG. 2 is a graph of concentration dependencies of G′ for the RIN (rinrin) tomato paste according to the invention and for tomato paste made from commercially available BOS 3155 tomatoes.
[0024] [0024]FIG. 3 is a graph comparing °Brix with G′ for the RIN (rinrin) tomato paste according to the invention and for tomato paste made from commercially available BOS 3155 tomatoes.
[0025] [0025]FIG. 4 is a graph showing qualitatively the differences in amounts of pectic oligomers for RIN (rinrin) and Bos 3155 paste serums.
DETAILED DESCRIPTION OF THE INVENTION
[0026] The rin gene, which is semidominate in tomato, is available from several sources, including the C. M. Rick Tomato Genetic Resource Center (TGRC) at the University of California, Davis. The rin gene is described in the literature, e.g., in Davies et al. and Tigchelaar et al., mentioned above.
[0027] Another mutant gene directed to impeding ripening is the “non-ripening” nor gene, which is recessive but has ripening and enzymatic characteristics which are very nearly identical to rin. (Buescher et al. 1976, Della Penna et al. 1987, Tigchelaar et al. 1978.) The paste characteristics of the homozygous nor gene can be expected to be nearly identical to those of the homozygous rin paste. Since the homozygous nor fruit suffers from the same color deficiencies as the homozygous rin, this gene likewise can be used in combination with a color enhancing gene in accordance with the invention.
[0028] The old gold crimson (og c ) color enhancing gene is readily available from several sources including the TGRC at UC, Davis, and is currently used in the tomato processing industry. This color variant was first described in 1962 (Butler and Tomes 1962) and was determined by Thompson et al. (1965) to be a single recessive gene. Fruit containing og c has a redder color and higher lycopene content than normal fruit. Other color enhancing genes, e.g., those mentioned above, are available and may be used in the present invention.
[0029] Whereas the color scores of homozygous rin pastes can be expected to be very low, e.g. USDA paste color scores at 8.5 Brix of <30, the pastes of the invention have good USDA paste color scores at 8.5 Brix. e.g. from 35-50, especially 42 or greater.
[0030] The homozygous rin plants may be made by at least two methods. The first utilizes a traditional breeding program. Of the several standard breeding methods, the backcross method is the most direct. A tomato line carrying the rin gene, such as LA3012, can be obtained from the C. M. Rick Tomato Genetics Resource Center at UC Davis or from another source and crossed with a commercially desirable cultivar such as FM6203, which can be obtained from Lockhart Seed Co. of Stockton, Calif. or numerous other seed dealers. Other appropriate open pollinated varieties would include Hunt 100 and UC82b. Multiple backcrosses to the recurrent parent (the commercial line) and selection of the rin phenotype would be conducted to recover the commercial cuitivar with the rin gene. After the final backcross (BC6), the tomato line would be selfed and the homozygous rin selected. Likewise, the preferred rinrin tomatoes homozygous for color enhancing genes can be prepared by breeding with FM6203.
[0031] Alternatively, the rinrin tomato can be obtained via plant transformation. In this method, the rin gene is cloned from a rin tomato line such as LA3012 and introduced into a desirable cultivar using transformation via tissue culture. Methods for transferring foreign DNA into plant cells include use of Agrobacterium tumefaciens as a vector, direct DNA uptake, e.g. facilitated by polyethylene glycol or electroporation, and microinjection of DNA into cells with a particle gun. Fertile plants are regenerated from the culture and these plants transmit the transferred gene to the next generation. If the transferred gene controls a recessive trait, selfing is necessary to make the gene homozygous, displaying the expected trait.
[0032] Plants heterozygous in both rin and nor can be obtained by crossing plants heterozygous in rin with plants heterozygous in nor.
[0033] The tomato homozygous in the rin gene and heterozygous or homozygous in the color enhancing gene can be obtained by using the transformed rinrin tomato as a starting point and either breeding or transforming the plant to include the color enhancing gene(s). Similarly, if desired, the rinrin tomato may be formed by breeding and the color enhancing gene introduced therein by transformation.
[0034] Although the use of homozygous color enhancing genes of the same type are preferred, it is also possible that tomatoes heterozygous in more than one type of color enhancing gene can be used.
[0035] The use of homozygous rin and/or nor genes is preferred. However, it is also possible that a tomato heterozygous in both the rin and the nor genes or homozygous in one of the rin or nor genes and heterozygous in the other may be used.
[0036] In accordance with the invention, various types of foods products can be prepared from the homozygous rin and/or nor tomatoes or heterozygous rin/nor tomatoes. For instance, red spaghetti sauce can be prepared. In general, red sauces, such as spaghetti sauces, will often satisfy the following parameters
[0037] 12 to 25 Brix
[0038] 4-13 cm Bostwick
[0039] 1-2% salt
[0040] pH 4.0 to 4.4
[0041] As a result of the unique qualities of the tomatoes and paste mentioned above, a sauce having outstanding quality can be prepared in accordance with the invention.
[0042] Among the types of sauces which can advantageously be prepared in accordance with the invention include, but are not limited to, red spaghetti sauce, other red pasta sauces, pesto sauce, salsa, tomato puree, pizza sauce, tomato sauce, BBQ sauce, catsup and soup.
EXAMPLE 1
[0043] (Prophetic)
[0044] A tomato plant which is homozygous for the rin mutant is produced by the backcross method, Open pollinated variety FM6203 is crossed with LA 3012. FM6203 is emasculated and pollen from LA3012 is applied to the stigma of FM6203. (Alternatively, crosses could be performed using FM6203 as the pollen parent.) The resulting F1 is then crossed again with FM6203. The BC1 progeny which contain rin are determined by selfing the BC1 and examining the BC1F1 for the homozygous rin phenotype.
[0045] Alternatively rin carriers can be ascertained by observing the fruit of the BC1 for the heterozygous rin traits such as delayed ripening and increased firmness. Repeated backcrossing to FM6203 and selection for the rin phenotype results in the rin character becoming fixed in the resulting cultivar.
EXAMPLE 2
[0046] An advanced processing tomato line homozygous for rin and also homozygous for the color enhancing gene old gold crimson was grown under typical field conditions in 50 ft. plots in California. Although fruit were delayed in ripening, ripe fruit were extremely firm with yellow external and red internal color. Approximately 100 pounds of fruit was harvested and processed using a bench scale hot break and tubular evaporator system (manufactured by Femco Co.). The rinrin tomato paste was concentrated to only 15.5° Brix due to the extreme viscosity of the puree. In contrast, paste of typical tomato cultivars is concentrated to 21-26° Brix using this equipment.
[0047] The data from the analysis of rinrin paste is given below. The paste attributes of the rinrin paste were compared with paste from a commercial tomato cultivar, (Bos 3155 which can be obtained from Lockhart Seed Co. of Stockton, Calif. or numerous other seed dealers) processed in the same manner and using the same equipment as the rinrin paste.
[0048] Comparison of rinrin and BOS 3155 Tomato Pastes
SUMMARY AND CONCLUSIONS
[0049] 1. rinrin paste is thicker than the Bos 3155 paste because of a combination of a more expanded particulate phase and a higher serum viscosity.
[0050] 2. The more expanded particulate phase is deduced from the lower serum/pellet ratio of the rinrin, and is consistent with a lower concentration onset for significant thickening (FIGS. 2 and 3).
[0051] 3. The viscosity of the serum phase of rinrin is very high (not only compared with Bos, which is relatively low, but also other pastes). This is probably the origin for the low blotter scores for rin and the high blotter scores for Bos 3155.
[0052] 4. Two lines of evidence suggest that the Bos paste suffered more enzymatic damage to pectins than the rinrin. The 5% esterification of pectic galacturonic acid was high in rin and relatively low in Bos 3155. This suggests that PME (pectin methylesterase) has not acted significantly on rin but has on Bos 3155. Secondly pectic oligosaccharides are more abundant in Bos than in rin, consistent with the significant action of PG on the former but not the latter. The fruit was not analyzed, so it is not known how much of these changes were caused in the fruit, and how much is due to response to process.
[0053] Methods and Definitions
[0054] Brix measurements—These values reflect the content of soluble sugars in the serum fraction of paste by determination of refractive index. The measurements were made using a Bellingham and Stanley Ltd RFM 320 Refractometer, calibrated against distilled water. A sample of tomato paste was squeezed through filter paper and two or three drops of serum placed on the measurement surface of the refractometer. The value measured by the Refractometer was recorded.
[0055] Blotter tests—From each sample, 7 ml of pastes was aspirated into a plastic syringe and was carefully transferred into the central circle of a half-hour blotter test card (Bridge and Company, Chancery Lane, London). The test card was placed on top of an upright plastic beaker, and after half an hour the distance (in millimeters) migrated by the serum of the tomato paste was recorded along each of the four axes (North, South, East and West). Two blotter tests were carried out for each sample, and the four values were averaged. The larger the blotter value, the greater the level of syneresis present in the sample.
[0056] USDA paste color test—The color of a tomato concentrate was measured after dilution to 8.5 Brix, using the ColorQuest Instrument from Hunter. The a & b values obtained from a UCD/USDA hitched instrument are computed using the following equation.
Paste & Puree=−46.383+1.02411( a )+10.607( b )−0.42198( B ){circumflex over ( )}2 Color Score
Juice Color=29.600+0.88354( a )−1.8553( b )
[0057] USDA Color Classifications are as follows:
Grade A 45-50 points Grade C 40-44 points Substandard 0-39 points
[0058] USDA grading of concentrate was done with equal weight given to color and absence of defects.
[0059] It should be noted that in addition to the tomato itself, color may be severely affected by thermal processing.
[0060] Serum:pellet ratios—these were determined by placing a weighed amount of each paste into a centrifuge tube, centrifuging at 5,000-10,000×g for 30 minutes, pouring off the serum, and recording the weights of the serum and the pellet. From these values the serum:pellet ratio can be calculated.
[0061] Serum viscosity—A Contraves Low Shear 30 Rheometer was used to measure the serum viscosity. A small amount of serum (approx 2 mls) prepared as for measuring serum:pellet ratios was placed in the cup-and-bob apparatus and a range of shear rates used to determine η° (viscosity at zero shear).
[0062] Small deformation rheology—A small amount of tomato paste mixture (approximately 3 g) was placed between parallel plates on a Rheometrics RDA2 (5 cm diameter, roughened by attachment of emery paper to plate surfaces to reduce slippage or surface friction phenomena). Frequency sweep measurements were made from 0.5-200 radian per second (rads 1 ), at 0.5% strain and at 30° C. G′ values were taken from the 10 rads 1 measurement. Time sweep measurements were made at 0.5% strain, 10 rads −1 and 30° C. All samples were sealed with liquid paraffin to avoid desiccation or water exchange.
[0063] Dry Weight Estimates—samples of the pastes as delivered and from the dilution series for the concentration dependencies were placed into preweighed 10 ml glass vials. These were then weighed to enable the mass of the wet sample to be calculated. The vials were allowed to dry to constant weight at 60° C. under vacuum (in a benchtop vacuum oven). Dry weights of the vials were measured and used to calculate the % dry wt. of the original samples.
[0064] Total serum polymer—17.2076 g of rinrin paste equivalent to 3.132 dry weight and 14.2781 g of Bos 3155 paste equivalent to 3.6980 g dry weight, were washed extensively with MilliQ deionised water and all water washings collected after centrifugation at 2300 rpm on a benchtop centrifuge. The collected washing for each sample were dialyzed with 6 exchanges of MilliQ deionised water using a 14,000 cutoff dialysis membrane. The resultant solution was freeze dried and the polymers weighed and used for further analysis.
[0065] Cell wall preparation from juice—Cell wall was prepared after removal of serum with sequential water washes, by washing in absolute ethanol until white. The material was then hydrated with water to a dry weight of ˜5%.
[0066] Sugar composition of serum polymers and cell wall—5 mg of hydrated cell wall and 1 mg of serum polymers isolated as above were incubated in a solution of mannitol containing the cell wall degrading enzymes Viscozyme, Celluclast and Novozyme from Novo Nordisk (final concentration of 488 nmols per 250 uL). The mixture was left overnight at 45° C. and freeze dried. Once dry, the samples were hydrolyzed at 87° C. in teflon capped screwtop tubes with dry 2 Molar methanol/HCl prepared fresh. The samples were worked up by neutralizing with silver carbonate and addition of 2 drops of acetic anhydride. The methanol layer was decanted off and evaporated to give the methylglycosides. These were analyzed as the silyl ethers on a Carlo-erba Mega GC using the temperature program 150° C.-200 at 2° C. on a CPSIL 5CB 25M column. Results were calculated after subtraction of an enzyme blank.
[0067] Degree of esterification (% galacturonic ester)—Serum polymer isolated as above was redissolved in MilliQ deionised water at a concentration of 1 mg/ml. 15 ml of each solution was then titrated to pH 7 and the volume of titrant noted to reach equivalence. 100 units of pectin methyl esterase (from Sigma) was added and the solution autotitrated using a Metrohm 718 Stat Titrino at pH 7 until complete deesterification had occurred. The total volume of titrant added was noted and the percent ester calculated as follows:
(ml Total−ml acid/ml Total)*100
[0068] Oligosaccharide analysis by Dionex—Samples of serum obtained by washing the pastes with 3 volumes of MilliQ water were run on a Dionex HPLC system with amperometric detection. The solvent system used was a binary system and the gradient used is given in the table below:
Time % 100 mm NaOH % 100 mm Sodium acetate 0 100 0 30 60 40 35 0 100 40 0 100 45 100 0
[0069] The column used was a 50 cm Carbopac PA100. Samples were filtered through a 0.45 um PVDF Whatman filter before injection.
[0070] Bostwick: The Bostwick Consistometer is commercially available and comprises a stainless-steel, rectangular trough with two compartments separated by a spring-loaded gate. The sample compartment measures 5 cm.×5 cm.×3.8 cm. The larger of the troughs measures 24 cm. in length, 5 cm. in width and is etched with graduations every 0.5 centimeter. A clean, dry consistometer, maintained at 20 deg. C., is placed on a flat surface and a spirit level placed in the larger trough. Leveling screws are used to adjust the position of the device.
[0071] A sample of a diluted and temperature adjusted tomato concentrate is placed in the sample compartment and its surface leveled off with the flat side of a spatula. The gate locking lever is tripped and immediately a timer started. The sample is allowed to flow down the length of the trough, under its own weight for a fixed amount of time (usually 30 seconds). The distance the front edge of the fluid travels is estimated to the nearest 0.1 centimeter.
[0072] The United States Department Of Agriculture uses this method in grading tomato concentrates. The tomato concentrate is diluted to 12.0 NTSS as measured by a refractometer on a centrifugate of the sample. An amount of distilled water is added to 100 grams of tomato concentrate in a plastic bag, to achieve the 12.0 NTSS. The sample and water are “stomached” (mixed) to achieve the uniform distribution of the paste in the water. The NTSS of the resulting material is tested again to confirm it to be 12.0 NTSS and if indicated, adjusted to achieve the desired value. Once the sample is diluted its temperature is adjusted to 20 deg. C. and the test performed.
[0073] The Bostwick Consistency of a tomato concentrate is the number of centimeters the material flows under its own weight in thirty seconds.
[0074] Results
[0075] General appearance—Three teaspoons of each paste were placed onto a clean dish and their appearance was noted after 30 minutes and 1 hr 30 minutes.
[0076] 30 minutes—The rinrin paste remained unchanged at 30 minutes. It still held shape and showed no signs of synersis (pooling). However the BOS 3155 control had slumped and spread a little with a ring of syneresed serum projecting around 2 mm from the central mass.
[0077] 1 hr 30 minutes—The rinrin paste was much the same as at 30 minutes. The BOS 3155 control had spread and the ring of syneresis was projecting approximately 6 mm from the edge of the solid mass.
[0078] Bostwick and Blotter Ranges for rin, BOS 3155 and Other Tomatoes (tomatoes with high viscosity). These paste were processed on the benchtop evaporator described in Example 2.
Bostwick Blotter U373 3.1-4.7 4.5-15.25 U370 3.4-4.0 10.0-16.75 Asgrow 5210 3.5-5.4 11.0-18.25 Antisense PG 3.7-5.3 5.6-17.5 BOS3155 4.5-6.1 13-22.5 Homoz RIN 0-2.0 <2.5
[0079] The USDA paste color scores were 47.98 for the rinrin paste and 47.87-50.19 (ave. 49.33) for the Bos 3155 paste.
[0080] The samples as received in the can had the following characters:
Sample % Dry Weight °Brix RIN 18.2% 16.56 BOS 3155 25.9% 24.76
[0081] Ratio of soluble to insoluble solids—FIG. 1 shows a plot of the dry weight values vs. their respective °Brix for the samples used in the concentration dependence. As can be seen both the RIN and BOS 3155 pastes have the same slope and the same origin indicating that the ratio of insoluble to soluble solids are the same. With this information in mind it was possible to run the serum pellet ratios balanced for both solids and °Brix in one experimental set.
[0082] Concentration Dependencies—The concentration dependence behaviors of G′ (10 rads/s) for RIN and BOS 3155 pastes are given in FIG. 2. RIN appears to have a lower effective C 0 at 7.5% dry wt than BOS at 10% dry wt. The form of the concentration dependencies also shows that RIN solids are capable of generating greater structure on a weight for weight basis than the BOS 3155 control. Because the °Brix to dry wt ratios are the same for the two pastes, plotting °Brix against G′ gives a very similar concentration behavior, as seen in FIG. 3.
[0083] Serum/Pellet Ratios at 12°Brix:
[0084] The results for serum/pellet ratios were as follows:
Replicate Serum (g) Pellet (g) s/p ratio RIN 1 13.16 9.06 1.45 2 14.79 9.7 1.52 3 13.45 9.33 1.44 BOS 3155 1 15.5 8.21 1.88 2 14.88 7.54 1.97 3 15.52 8.02 1.93
[0085] Blotters—Run on 12°Brix paste
RIN Paste Rep. Time North South East West Avg. 1 10 min 0 0 0 0 0 20 min 2 1 1 1 1.3 30 min 3 2 2 1 2 2 10 min 0 0 0 0 0 20 min 1 1 0 1 0.75 30 min 2 2 1 1 1.5
[0086] [0086] BOS 3155 paste Rep. Time North South East West Avg. 1 10 min 3 4 5 4 3 20 min 10 8 7 8 8.25 30 min 11 12 11 10 11 2 10 min 4 4 4 4 4 20 min 8 8 7 7 7.5 30 min 10 10 9 9 9.5
[0087] [0087] Serum results η 0 values at Polymer weight Percentage 20° C. (mg/g dry galacturonic (mPas) weight paste) acid esterified RIN 38.25 64.6 73 BOS 3155 4.81 64.2 40
[0088] [0088] Sugar analysis results Rin 3155 3155 cell Sugar serum Rin cell wall serum wall ararabinose 3 3 4 2 rhamnose 4 3 8 1 xylose 1 11 1 10 mannose 3 6 4 7 Galactose 6 6 4 5 Galacturonic 80 23 76 9 Acid Glucose 3 49 2 65
[0089] Dionex Results
[0090] These results, shown graphically in FIG. 4, were unquantified as no standards were available. However, qualitatively there were differences in the amounts of pectic oligomers produced between the two paste serums. The RIN cross had qualitatively fewer pectic oligomers caused by pectin breakdown either during processing or through natural fruit ripening.
[0091] Overall, the data establish that pastes according to the invention have quite good viscosity together with good color.
EXAMPLE 3
[0092] (Prophetic)
[0093] A spaghetti sauce is prepared in accordance with the invention using a puree made solely from rinrin tomatoes. A standard, conventional spaghetti sauce made from tomatoes other than rinrin tomatoes is also prepared. The sauces are prepared by mxing together the ingredients, heating and stirring.
[0094] Spaghetti Sauce Formulas
STANDARD RIN PUREE PUREE INGREDIENT PERCENT PERCENT WATER 33.300 65.300 TOMATO PUREE @ 15.5 BRIX 64.000 32.000 SOYBEAN SALAD OIL 1.000 1.000 SALT, ROCK 1.000 1.000 ONIONS 0.500 0.500 SPICES 0.200 0.200
[0095] The sauce according to the invention made from rin paste has excellent quality, in particular, improved viscosity and syneresis compared to the conventional sauce. Moreover, the sauce of the invention includes substantially more large pectin chains. In addition, a secondary benefit is the fact that less puree needs to be used in the sauce of the invention as compared to the standard sauce.
[0096] Tomatoes in accordance with the invention fall within the genus Lycopersicon and preferably, though not necessarily, within the species Lycopersicon esculentum.
[0097] Preferably the pastes of the invention are made from essentially the same tomato plants. That is, the pastes of the invention preferably achieve the desired attributes of color and viscosity without resort to substantial amounts of tomato fruits which are not either a) homozygous for the rin and/or nor genes or b) heterozygous for both rin and nor genes. Preferably the paste is made from at least 90%, more preferably at least 95% of tomatoes and most preferably at least 99 wt % of tomatoes which are either a) homozygous for the rin and/or nor genes or b) heterozygous for both rin and nor genes. It is especially preferred that the paste comprises at least 90%, more preferably at least 95% of tomatoes and most preferably at least 99 wt % of tomatoes which are i) either homozygous or heterozygous, preferably homozygous, in at least one non-native color enhancing gene and ii) either a) homozygous for the rin and/or nor genes and/or b) heterozygous for both rin and nor genes.
[0098] All percentages herein are by weight unless stated otherwise or otherwise required by context.
[0099] It should be understood, of course, the specific forms of the invention herein illustrated and described are intended to be representative only as certain changes may be made therein without departing from the clear teachings of the disclosure. For instance, other ways of improving the color of tomatoes which are homozygous in rin and/or nor or which are heterozygous in rin and nor may occur to those skilled in the art. These may include breeding of the rin or nor tomatoes with certain tomatoes having desirable color attributes.
[0100] Reference should be made to the following appended claims in determining the full scope of the invention.
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Homozygous rin and/or nor tomatoes, or tomatoes heterozygous in both rin and nor are used to prepare a tomato paste, juice or sauce having good viscosity as well as good color. Preferably the tomatoes used also include color enhancing genes such as old gold crimson (og c ), high pigment (hp), dark green (dg), intense pigment (Ip), or color enhancing transgenic genes.
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This application claims the benefit of priority of PCT/KR2011/004683 filed on Jun. 27, 2011 and U.S. Provisional Application Nos. 61/358,935 filed on Jun. 27, 2010 and 61/425,739 filed on Dec. 21, 2010, all of which are incorporated by reference in their entirety herein.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a digital receiver and a method for processing caption data in the digital receiver, and more particularly, to a digital receiver that provides 3-Dimensional (3D) caption data and a method for processing 3D caption data in the digital receiver.
2. Discussion of the Related Art
A 3-Dimensional (3D) image allows the user to experience 3D effects using the principle of stereo vision which provides the sense of perspective through different views of the two eyes which are separated by about 65 mm, i.e., through binocular parallax due to the distance between the two eyes. The 3D image is provided such that corresponding planar images are viewed with the left and right eyes, thereby allowing the user to experience 3D and perspective effects.
Existing broadcast services have been two-dimensional (2D) services until now from the analog broadcast era even though digital broadcasts are currently active.
However, interest in a 3D service of a 3D (or stereoscopic) image that provides more realism and perspective, compared to a planar 2D service, has increased recently, starting from a specific field of application, and thus investment in 3D services and related services have gradually increased.
Interest in and studies into a digital receiver which can provide a 3D service have also increased.
However, a conventional digital receiver provides only 2D caption data and handles caption data of content as 2D caption data even when the content is 3D such that the user cannot satisfactorily view the caption data, thus providing user discomfort.
SUMMARY OF THE INVENTION
The present invention has been made to overcome the above problems and an object of the present invention is to provide a digital receiver that can provide 3D caption data while maintaining compatibility with legacy devices.
Another object of the present invention is to appropriately control, when a plurality of 3D caption data is provided, all or each of the plurality of caption data.
Another object of the present invention is to prevent, when disparity information of 3D caption data has changed, the user from experiencing vertigo due to processing associated with change in the 3D caption data.
The present invention provides a digital receiver for providing 3D caption data and a processing method for the same.
A method for transmitting a broadcast signal for a three-dimensional, 3D, service in one aspect of the present invention includes encoding a 3D video Elementary Stream, ES, including a 3D caption service, generating signaling information for signaling a 3D video service including the encoded 3D video ES, and transmitting the digital broadcast signal including the 3D video service and the signaling information, wherein the 3D caption service includes a first command code for generating left caption data and a second command code indicating a disparity value of a caption window and right caption data is generated based on the first command code and the second command code.
The second command code may include a flag indicating whether or not the same disparity value is to be applied to all currently decoded windows regardless of a window ID in a receiver.
The disparity value indicated by the second command code according to a value of the flag may be applied to all caption windows or to a caption window of a specific window ID indicated in the second command code.
The 3D caption service data may be extracted from one of a Supplemental Enhancement Information, SEI, message or a picture header of the 3D video ES.
A method for processing a broadcast signal for a three-dimensional (3D) service in accordance with another aspect of the present invention includes receiving a digital broadcast signal including an encoded 3D service and signaling information for the encoded 3D service, extracting a 3D video Elementary Stream, ES, from a 3D service, extracting data for a 3D caption service from the extracted 3D video ES, and providing a 3D caption service using the extracted 3D caption service data, wherein the extracted 3D caption service includes a first command code for generating left caption data and a second command code indicating a disparity value of a caption window and right caption data is generated based on the first command code and the second command code.
The second command code may include a flag indicating whether or not the same disparity value is to be applied to all currently decoded caption windows regardless of a window ID.
The disparity value indicated by the second command code according to a value of the flag may be applied to all caption windows or to a caption window of a specific window ID indicated in the second command code.
The 3D caption service data may be extracted from one of a Supplemental Enhancement Information, SEI, message or a picture header of the 3D video ES.
The 3D caption service data may further include a third command code for performing control for allowing a corresponding caption window to be located at a depth corresponding to a different disparity after a number of frames corresponding to a frame count have elapsed.
A value corresponding to the third command code may gradually change a disparity at an every frame or intervals of a predetermined frame period.
A method for processing a broadcast signal for a three-dimensional (3D) service in accordance with another aspect of the present invention includes receiving a digital broadcast signal including an encoded 3D service and signaling information for the encoded 3D service, extracting a 3D video Elementary Stream, ES, from a 3D service, extracting data for a 3D caption service from the extracted 3D video ES, and providing a 3D caption service using the extracted 3D caption service data, wherein the extracted 3D caption service includes a first command code for generating left caption data, a second command code indicating a disparity value of a caption window, and a third command code for performing control for allowing a corresponding caption window to be located at a depth corresponding to a different disparity after a number of frames corresponding to a frame count have elapsed, and right caption data is generated based on the first command code and the second command code.
A method for processing a broadcast signal for a three-dimensional (3D) service in accordance with another aspect of the present invention includes receiving a digital broadcast signal including a 3D service and signaling information for the encoded 3D service, extracting a 3D video Elementary Stream, ES, from a 3D service, extracting data for a 3D caption service from the extracted 3D video ES, determining a coordinate of a caption window using a first command code for generating left caption data, the first command code being included in the extracted 3D caption service data, determining a disparity value of a caption window according to a second command code indicating a disparity value of the caption window, determining a coordinate of a corresponding caption window that is to be overlaid on right caption data using horizontal size information of a video ES and a disparity, storing caption data in an image format, mixing left caption data and a left video picture and right caption data and a right video picture, and interleaving mixed images according to a display format and outputting the interleaved images.
A digital receiver for processing a three-dimensional (3D) service in accordance with another aspect of the present invention includes a reception unit configured to receive a digital broadcast signal including the 3D service and signaling information for the 3D service, a demultiplexer configured to demultiplex the digital broadcast signal into the 3D service and the signaling information, a decoder configured to extract and decode a 3D video Elementary Stream, ES, from the 3D service and extract and output 3D caption data from the extracted 3D video ES, a caption data processor configured to decode the extracted 3D caption data, a graphic processor configured to process and store a caption image of left and right view images based on the decoded 3D caption data, a mixer configured to mix 3D video data and 3D caption data, a 3D formatter configured to interleave and output the mixed data according to a display format, and a display unit configured to output interleaved 3D service data.
The 3D caption data may includes a first command code for generating left caption data, a second command code indicating a disparity value of a caption window, and a third command code for performing control for allowing the caption window to be located at a depth corresponding to a different disparity after a number of frames corresponding to a frame count have elapsed, and right caption data may be generated based on the first command code and the second command code.
The second command code may include a flag indicating whether or not the same disparity value is to be applied to all currently decoded caption windows regardless of a window ID and the digital receiver may apply the disparity value indicated by the second command code according to a value of the flag to all caption windows or to a caption window of a specific window ID indicated in the second command code.
The present invention has a variety of advantages.
First, it is possible to provide the digital receiver with 3D caption data while maintaining compatibility with legacy devices.
Second, when a plurality of 3D caption data is provided, it is possible to fully or individually control the plurality of 3D caption data.
Third, even when disparity information of 3D caption data has rapidly changed, it is possible to perform processing so as to prevent the user from experiencing vertigo.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates an exemplary digital receiver according to the present invention;
FIGS. 2 and 3 illustrate a caption for stereoscopic display according to the present invention;
FIG. 4 illustrates an exemplary procedure for processing 3D caption data in the digital receiver according to the present invention;
FIG. 5 illustrates exemplary code set mapping for disparity coding according to the present invention;
FIG. 6 illustrates an exemplary command code for disparity coding according to the present invention;
FIG. 7 shows a table illustrating an exemplary usage scenario according to the present invention;
FIG. 8 illustrates exemplary code set mapping for smooth change of the depths of caption windows according to the present invention;
FIGS. 9 and 10 illustrate exemplary command codes for smooth change of the depths of caption windows according to the present invention; and
FIG. 11 illustrates another exemplary procedure for processing 3D caption data in the digital receiver according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Various embodiments of an image processing apparatus and method according to the present invention are described in detail with reference to the accompanying drawings.
The present invention relates to a digital receiver and a method for processing caption data of a digital receiver and more particularly to the digital receiver that provides 3-Dimensional (3D) caption data and a method for processing 3D caption data in the digital receiver.
This disclosure describes various embodiments of the present invention in the following aspects. First, 3D caption data is provided to the digital receiver while maintaining backward compatibility with legacy devices. Second, when a plurality of 3D caption data is provided, all or each of the plurality of caption data is appropriately controlled. Third, when disparity information of the provided 3D caption data is changed, processing of the disparity information is performed such that the user does not experience vertigo due to the processing of the disparity information. Specifically, if disparity information is applied immediately when the disparity information has sharply changed, the sharply changed disparity may provide user discomfort, thereby causing the user to experience uncomfortable during 3D viewing.
The above aspects of the present invention are sequentially described below with reference to the accompanying drawings.
For better understanding and ease explanation of the present invention, the digital receiver may be exemplified by a digital television receiver that includes a component for 3D service processing. The digital television receiver may be a receiving set that includes a set-top box including the component for 3D service processing and a digital unit for outputting a 3D service processed by the set-top box. The digital television receiver may also be provided in the form of an integrated processing module. The digital receiver may also include any device, which receives, processes, and/or provides a 3D service, such as a Personal Digital Assistant (PDA), a mobile phone, or a smart phone. The digital receiver may also be one of a 3D only receiver and a receiver for both 2D and 3D.
Methods for expressing a 3D image include a stereoscopic image display method which takes into consideration 2 views and a multi-view image display method which takes into consideration 3 or more views. The conventional single-view image display method is also referred to as a monoscopic image display method.
The stereoscopic image display method uses a pair of images acquired by capturing the same subject using two cameras, i.e., a left camera and a right camera. The multi-view image display method uses 3 or more images acquired by capturing the same subject using 3 or more cameras having predetermined distances or angles.
Although the present invention is described below with reference to the stereoscopic image display method as an example, the spirit of the present invention can also be applied to the multi-view image display method according to the same or similar principle.
Transmission formats of a stereoscopic image are classified into single video stream formats and multi-video stream formats.
The single video stream formats include side-by-side, top/down, interlaced, frame sequential, checker board, and anaglyph formats and the multi-video stream formats include full left/right, full left/half right, and 2D video/depth formats.
A stereoscopic image or a multi-view image may be transmitted after being compressed and encoded through various image compression coding schemes including Moving Picture Experts Group (MPEG).
For example, a stereoscopic image in the side-by-side, top/down, interlaced, or checker board format may be transmitted after being compressed and encoded through an H.264/Advanced Video Coding (AVC) scheme. Here, a receiving system may obtain a 3D image by decoding the stereoscopic image in a reverse manner of the H.264/AVC coding scheme.
A left view image among full left/half right view images or one of multi-view images is a base layer image and the remaining image is assigned as an enhanced layer image. The base layer image may be transmitted after being encoded using the same scheme as a monoscopic image. On the other hand, the enhanced layer image may be transmitted after only correlation information between the base layer and enhanced layer images is encoded. For example, JPEG, MPEG-1, MPEG-2, MPEG-4, H.264/AVC, or the like may be used as a compression coding scheme of the base layer image. H.264/Multi-view Video Coding (MVC) may be used as a compression coding scheme of the upper layer image. Here, while the stereoscopic image is allocated as a base layer image and an enhanced layer image, the multi-view image is allocated as a base layer image and a plurality of enhanced layer images. A reference for dividing the multi-view image into a base layer image and one or more enhanced layer images may be determined based on the positions of cameras or based on the arrangement of the cameras. Such a reference for division may also be arbitrarily determined without a specific criterion or rule.
Such 3D image display types are broadly classified into a stereoscopic type, a volumetric type, and a holographic type. For example, a 3D image display device that employs such stereoscopic technology adds depth information to a 2D image and allows users to experience 3D liveliness and realism through such depth information.
3D image viewing types are broadly classified into a glasses type and a glass-free type.
The glasses type is classified into a passive type and an active type. The passive type uses polarized light filters to allow the user to separately view a left-eye image and a right-eye image. The passive type also includes a type which allows the user to view 3D images using green and red colored glasses respectively with the two eyes. On the other hand, the active type separates left and right view images using liquid crystal shutters which open left and right glasses sequentially in time to separate left-eye and right-eye images. In the active type, time-divided screens are repeated at intervals of a predetermined period and electronic shutters which are synchronized with the period are mounted on glasses which the user wears to view 3D images. Such an active type is also referred to as a time-split type or a shuttered glass type.
Typical glass-free types include a lenticular type in which a lenticular lens plate, on which a cylindrical lens array is vertically arranged, is installed at a front side of a display panel and a parallax barrier type in which a barrier layer having periodic slits is provided on top of a display panel. However, the present invention is described below with reference to the glasses type as an example for ease of explanation.
FIG. 1 illustrates an exemplary digital receiver according to the present invention.
As shown in FIG. 1 , the digital receiver according to the present invention includes a reception unit 110 , a demodulator (or demodulation part) 120 , a demultiplexer (demultiplexing part) 130 , a signaling information processor (or SI processing part) 140 , an audio/video (A/V) decoder 150 , a caption data processor 160 , a graphics engine 170 , an On-Screen Display (OSD) processor 180 , a mixer 185 , a 3D output formatter 190 , and a controller 195 .
The following is a description of basic operations of the components of the digital receiver and the present invention will be described in more detail in each embodiment described later.
The reception unit 110 receives a digital broadcast signal including 3D image data and caption data for the 3D image data from a content source through an RF channel.
The demodulator 120 demodulates the received digital broadcast signal using a demodulation scheme corresponding to a modulation scheme that has been applied to the digital broadcast signal at the transmitting side.
The demultiplexer 130 demultiplexes the demodulated digital broadcast signal into audio data, video data, and signaling information. Here, the demultiplexer 130 may perform filtering on the demodulated digital broadcast signal using a Packet IDentifier (PID) to demultiplex the demodulated digital broadcast signal into audio data, video data, and signaling information. The demultiplexer 130 outputs the demultiplexed audio and video signals to the A/V decoder 150 and outputs the signaling information to the signaling information processor 140 .
The signaling information processor 140 processes the signaling information received from the demultiplexer 130 and provides the processed signaling information to each component which requires the processed signaling information. Here, although the signaling information may include System Information (SI) such as Digital Video Broadcasting-Service Information (DVB-SI), Program Specific Information (PSI), and Program and System Information Protocol (PSIP) information, the following description is given with reference to PSI/PSIP information as an example for ease of explanation. The signaling information processor 140 may internally or externally include a database (DB) that temporarily stores the processed signaling information. The signaling information will be described in more detail in each embodiment described later.
The signaling information processor 140 determines whether or not signaling information, which indicates whether corresponding content is a 2D image or a 3D image, is present. Upon determining that the signaling information is present, the signaling information processor 140 reads and transmits the signaling information to the controller 195 . The signaling information processor 140 parses a Program Map Table (PMT) and/or an Event Information Table (EIT) for a 3D caption service and extracts a descriptor for a caption service from the parsed PMT and/or EIT and delivers the extracted descriptor to the video decoder (and/or controller) such that the caption service for the 3D service is appropriately processed at the video decoder (and/or controller).
The A/V decoder 150 receives and decodes the demultiplexed audio/video data. Here, the A/V decoder 150 may decode the data, for example, based on the signaling information processed by the signaling information processor 140 .
In the following, a description of audio data processing is omitted and, primarily, video data processing associated with the present invention is described in more detail. A video signal, i.e., a 3D video ES, includes a header & extensions part including information items for video data processing and a part including actual video data.
In association with this, the video decoder according to the present invention may identify and process caption data received through a corresponding caption service channel, for example, based on the caption service descriptor extracted from the PMT and/or EIT.
The A/V decoder 150 includes a header & extensions unit 154 that processes the header & extensions part and a video data processor 152 .
In association with the present invention, the header & extensions unit 154 extracts caption data and provides the extracted caption data to the caption data processor 160 . Here, the caption data includes, for example, 3D caption data according to the present invention.
The caption data processor 160 decodes the caption data extracted and provided from the header & extensions unit 154 . Here, the caption data processor 160 may decode the caption data, for example, based on the signaling information processed by the signaling information processor 140 .
The graphics engine 170 generates a control signal for processing or the like required to provide each caption data item decoded by the caption data processor 160 in a 3D format and generates OSD data including 3D caption data according to the present invention through the OSD processor 180 . The graphics engine 170 and the OSD processor 180 generate a full-resolution caption image for a left-eye image and a right-eye image and store the generated caption image in a buffer or memory (not shown).
The video data processor 152 extracts and decodes actual video data from the 3D video ES.
Each data item of the decoded 3D video ES is appropriately mixed at the mixer 185 via the corresponding component.
The 3D output formatter 190 formats and outputs the 3D video signal and the OSD data including the 3D caption data for the 3D video signal, which are mixed at the mixer 185 , into a 3D output format. Here, the 3D output formatter 190 may be activated only when the decoded image data is 3D image data. That is, when the decoded image data is 2D image data, the 3D output formatter 190 is deactivated, i.e., the 3D output formatter 190 outputs the input image data without any special processing. Namely, here, the image data may bypass the 3D output formatter 190 . The 3D output formatter 190 performs resizing or the like on the input image data according to the 3D format type of the 3D display (such as side-by-side or top/down), for example, in an input procedure of the image data.
The 3D output formatter 190 performs processing required for conversion from the decoded input video format into an output format.
In association with this, a video processing block(s) for artifact reduction, sharpness enhancement, contrast enhancement, de-interleaving, frame rate conversion, and/or other types of quality enhancement blocks may be performed between the A/V decoder 150 and the 3D output formatter 190 (3D output formatter performs the required conversion from the input (decoded) video format to a native 3D display format. Video processing such as artifact reduction, sharpness, contrast enhancement, de-interleaving, frame rate conversion, and other types of quality enhancement blocks may be present between the A/V decoder 150 and the 3D output formatter 190 ).
The controller 195 performs overall control of the digital receiver and may also control the A/V decoder 150 , the controller 195 , the caption data processor 160 , the graphics engine 170 , the OSD processor 180 , and the 3D output formatter 190 based on the signaling information processed by the signaling information processor 140 to allow 3D caption data to be appropriately processed together with the 3D service. A description of such detailed control will be given later in more detail.
In association with provision of 3D caption data in a digital receiver, the present invention defines a caption data command code for a stereoscopic 3DTV using an offset of left-eye and right-eye images while maintaining backward compatibility with the caption data processing method of the legacy digital receiver and also suggests a processing method associated with the defined caption data command code. Especially, in the present invention, when the same depth is applied to a plurality of windows in the same screen, it is possible to specify the depths of all windows using a single command.
In the following description, the present invention will be described focusing on provision and processing of 3D caption data for a 3D service for ease of explanation. That is, a detailed description of the content of a 3D service associated with the present invention, for example, a detailed description of identification, processing, or the like of a 3D service will be omitted and only a necessary description thereof will be given.
FIGS. 2 and 3 illustrate a caption for stereoscopic display according to the present invention.
Examples of FIGS. 2 and 3 illustrate a 2D caption having a 3D positioning feature. Specifically, FIGS. 2( a ) and 2 ( b ) illustrate how a 2D caption is positioned to create a 3D caption and illustrate the 3D caption more three-dimensionally.
FIGS. 2( a ) and 2 ( b ) also show a left video plane (primary plane) and a right video plane (secondary plane), respectively.
When caption text is positioned on the left video plane as a primary plane as shown in FIG. 2( a ), the caption text is positioned on the right video plane as a secondary plane at a position corresponding to a disparity value for a caption window as shown in FIG. 2( b ).
Finally, the planes of FIGS. 2( a ) and 2 ( b ) are combined to provide a 3D caption.
Referring to FIG. 3 , a screen plane 310 is present on an x-y plane having a z-axis value of 0 (z=0) corresponding to zero disparity and video object # 1 ( 320 ) and video object # 2 ( 330 ) have negative disparity and positive disparity, respectively.
A caption window 340 having more negative disparity than the video object # 1 is also present. The negative disparity of the caption window 340 has a depth value obtained from a disparity parameter described below.
The following is a description of an exemplary procedure for processing 3D caption data in a digital receiver according to the present invention.
FIG. 4 illustrates an exemplary procedure for processing 3D caption data in the digital receiver according to the present invention.
The video decoder receives a 3D video Elementary Stream (ES) (S 402 ). Here, it is assumed that the 3D video ES has been coded, for example, into the top & bottom format. In this case, left view image data may be located at the bottom and right view image data may be located at the top.
The video decoder detects caption data included in a picture header (or Supplemental Enhancement Information (SEI) message) of the 3D video ES and provides the detected caption data to the caption data processor and the caption data processor then decodes the received caption data (S 404 ).
The graphics engine and/or OSD processor determines the x-y coordinates of a caption window using a DefineWindow command (S 406 ). Here, the determined x-y coordinates may be associated with, for example, left view image data.
The graphics engine and/or OSD processor determines a disparity value for the corresponding caption window through a SetDepthPos command (S 408 ). This may be referred to as a start disparity.
The graphics engine and/or OSD processor extracts an Aw_flag and applies the same disparity value to all currently detected windows regardless of the window ID field if the extracted aw_flag is 1. On the other hand, the graphics engine and/or OSD processor extracts an aw_flag and applies the disparity value only to a caption window specified by the window ID field if the extracted aw_flag is 0 (S 410 ).
The graphics engine and/or OSD processor determines x-y coordinates of the corresponding caption window that is to be overlaid on right view image data using the horizontal size of the video ES and the disparity (S 412 ). Here, how the coordinates are determined will be described in more detail later.
The graphics engine and/or OSD processor stores caption data acquired by decoding other commands such as a pen command and a text command in an image format (S 414 ). Here, the same image may be used for left and right video pictures. However, the coordinates of the left and right video pictures may be different due to the disparity.
The digital receiver mixes a left caption and a left video picture through the mixer. In this procedure, when left view image data of the 3D video ES is half resolution image data, vertical resizing is performed on the left caption (S 416 ). An image obtained through such mixture is hereinafter referred to as a left output image.
The digital receiver mixes a right caption and a right video picture through the mixer (S 418 ). In this procedure, vertical resizing is performed on the right caption in the same manner as on the left caption since the right view image of the 3D video ES is half resolution. An image obtained through such mixture is hereinafter referred to as a right output image.
The 3D output formatter interleaves the left output image and the right output image appropriately according to the display type and outputs the resulting images in the stereoscopic video display output procedure (S 420 ). For example, when the display type is a horizontal line interleaving type which requires passive glasses, the 3D output formatter outputs the left output image and the right output image alternately line by line on the screen.
In association with the embodiments described above, metadata (for example, metadata associated with disparity between a left view image and a right view image) for processing of a 3D service and 3D caption data for the 3D service is defined and described below in detail.
Text (character) data may be coded according to a typical method described in the related standard.
X-Y coordinates of a 3DTV closed caption for a left view image may be coded using a typical method such as an anchor position based method.
The receiver may display closed caption data of the left view image using the typical method.
The receiver may then display a caption of the right view image at a front side or at a rear side of (i.e., in front of or behind) the screen plane along the depth axis.
The position of the closed caption on the right view image is determined using a given disparity (offset) value according to a suggested method.
A coding scheme is used to transmit disparity information. Here, the disparity information may be associated with an extension of an existing 2D closed captioning coding scheme.
The disparity described herein may be applied to any closed captioning data that is rendered in a caption window specified by the window ID in the disparity command code. When a new disparity value is received for a window having a predefined disparity value, the caption window simply moves along the depth axis.
A disparity value determined according to the display resolution of an image which is 1920 pixels wide is described below. When the receiver displays images in a narrower or broader area according to display resolutions, a pixel offset used to render captions is scaled according to an appropriate value. For example, when the resolution of an image to be displayed is 640 pixels wide, an offset applied to the right image caption is D*640/1920, where D is a disparity received in a closed captioning data string.
Metadata defined according to the present invention is described below in more detail.
FIG. 5 illustrates exemplary code set mapping for disparity coding according to the present invention and FIG. 6 illustrates an exemplary command code for disparity coding according to the present invention.
Metadata (i.e., a command code) defined according to the present invention may be defined as a new code, for example, using one of the unused codes in a C 0 set (3-byte control code) of the related standard which is illustrated in FIG. 5 for better understanding and ease of explanation of the present invention. However, the present invention is not limited to this example.
A command code for disparity coding according to the present invention is described in more detail below with reference to FIG. 6 .
The command code for disparity coding is a total of 3 bytes. That is, the command code of FIG. 6 defines, for example, SetDepthPos (0x19), which describes the depth position of a caption window, and related data (data1 and data2).
Here, the command type may be window and the format may be that of the depth code. In addition, the depth code includes a window ID and a disparity parameter.
As shown in FIG. 6 , the Most Significant Byte (MSB) of the data 1 may be an aw_flag field. Here, the aw_flag field indicates that a disparity parameter specified by “dp_sign and dp” described below is applied to all caption windows when the aw_flag field has a value of 1 and indicates that the disparity parameter is applied only to a window specified by the window ID when the aw_flag field has a value of 0.
The window ID indicates a unique window identifier. Up to 8 windows may be present per screen and the value of the window ID may indicate one of 0 to 7.
The disparity parameter (dp_sign, dp) specifies a disparity (offset) value between closed caption windows in left and right images in pixels. The disparity parameter may be specified (or described) for a display image resolution of 1920 pixels wide.
SetDepthPos specifies the Depth position of a window and a window ID to which this Depth position is applied (SetDepthPos specifies the Depth position of the window and the window ID this Depth position applies to). The window ID is required to indicate (or address) a window which has already been created by the DefineWindow command (The window ID is required to address a window which has already been created by the DefineWindow command). The Depth position is determined by a disparity parameter which is associated with the displacement between the caption windows on the left and right images (The Depth position is determined by the disparity parameter which is the displacement between the caption windows on the left and right images). SetDepthPos is a 3-byte command code to carry the disparity information (SetDepthPos is a 3-byte command code to carry the disparity information). The code 0x19 (code for SetDepthPos) indicates the following two bytes which specify the disparity for the caption window (The code 0x19 (code for SetDepthPos) indicates that the following two bytes specify the disparity for the caption window).
The legacy device handles the SetDepthPos command as an undefined 3-byte code. Accordingly, the legacy device will ignore the SetDepthPos command together with the following two bytes.
FIG. 7 shows a table illustrating an exemplary usage scenario according to the present invention.
The table of FIG. 7 is mainly divided into coded values for 3D caption data of the usage scenario according to the present invention and values rendered in the display system, i.e., in the digital receiver.
The coded values include two types of values, i.e., a coded disparity value (N) and an anchor horizontal position (A).
The values rendered in the digital receiver include a displayed video width (W), a description (offset) value used for rendering the caption, a horizontal position of the caption window in the left image, and a horizontal position of the corresponding caption window in the right image.
In the usage scenario, it is assumed, for example, that the left image is a primary view image and the right image is a secondary view image.
All numbers in the table may indicate, for example, pixels.
According to the related standard, the horizontal position indicates the leftmost pixel of the caption window.
The horizontal position of the caption window and the rendered offset may be obtained based on resolution of displayed left and right images rather than based on spatial compression resolution.
The following is a description of a processing method for smooth change of the caption depth according to the present invention.
The above and following descriptions are associated with a mechanism for supporting change of the depth axis of a caption window to which the number of frames, an end disparity, and an initial disparity are provided.
The initial disparity value may be specified by the SetDepthPos command described above.
Here, ChangeDepthPos specifies the end disparity value and the number of frames during which a smooth change occurs in the caption depth (ChangeDepthPos will specify the end disparity value and the number of frame count during which the smooth variation of caption depth takes place).
FIG. 8 illustrates exemplary code set mapping for smooth change of the depths of caption windows according to the present invention.
The code set mapping of FIG. 8 differs from the code set mapping for disparity coding shown in FIG. 5 although both are similar in some aspects.
As described below, in the example of FIG. 8 , at least two command codes SetDepthPos and ChangeDepthPos are used for smooth change of the depths of caption windows according to the present invention and the two command codes differ in that the first command code SetDepthPos is used in “C 0 ” and the second command code ChangeDepthPos is used in “C 2 ”.
In this regard, code space, command code, and the like are described below.
FIGS. 9 and 10 illustrate exemplary command codes for smooth change of the depths of caption windows according to the present invention.
Basically, the ChangeDepthPos command code specifies the depth position of the caption window. Here, the command type may be window and the format may be that of ChangeDepthPos (window ID, end disparity value, and the number of frames).
The following is a detailed description of parameters.
The ChangeDepthPos command code may include a total of 4 bytes. The command code (or command coding) may be include EXT1+ChangeDepthPos+<data1>+<data2>+<data3>. Here, ChangeDepthPos is defined as 0x19 in the example of FIG. 10 while ChangeDepthPos is defined as 0x18 in the example of FIG. 9 . The difference between the two command codes is associated with whether an aw_flag is used in association with the present invention.
A detailed description of the aw_flag and the window ID shown in FIG. 9 is omitted since the aw_flag and the window ID are similar to those shown in the previous figures.
Referring to FIGS. 9 and 10 , the end disparity value (dp_sign, dp) specifies a resulting disparity (offset) value between closed caption windows in left and right images in pixels after the number of frames specified by the frame count. This disparity parameter is specified (or described) for a display image resolution of 1920 pixels wide.
The frame count (fc) may indicate the number of frames during which during which such a smooth change occurs in the disparity from the initial disparity value to the end disparity value of the window (frame count (fc) may indicate the number of frames during which the variation of disparity from the initial disparity value to the end disparity value of the window is taking place).
The following is a description of a ChangeDepthPos command code for smooth (or gradual) change of the caption window in the above procedure.
ChangeDepthPos specifies smooth change of the depth position of the window by specifying the duration of the variation and the target disparity values (ChangeDepthPos specifies the smooth changing of depth position of the window by specifying the duration of the variation and the target disparity values). ChangeDepthPos also specifies the window ID of a window to which such a smooth change is applied. The window ID indicates a window which has already been created by the DefineWindow command (The window ID is required to address a window which has already been created by the DefineWindow command). The initial depth position of the window is determined by the disparity value specified in the SetDepthPos command (The initial depth position of the window is determined by the disparity value specified in SetDepthPos command). The window will move along the z axis using the end disparity value and the frame count (The window will move along the z-axis using end disparity value and frame count). The receiver will adjust the disparity of the window ID after the number of frames specified by the frame count such that the final disparity of the window is the end disparity value (The receiver will adjust the disparity of the window ID so that after the number of frames specified by frame count, the final disparity of the window will be end disparity value).
Legacy devices will handle the 4-byte ChangeDepthPos command as an undefined 4-byte code. Therefore, legacy devices will ignore the ChangeDepthPos command together with the following three bytes.
Here, note that ChangeDepthPos can specify change of the depth for up to 255 frames. If a change needs to be made in the depth for a duration longer than 255 frames, this may be signaled using multiple pairs of SetDepthPos and ChangeDepthPos commands (Note that ChangeDepthPos can specify the variation of depth for up to 255 frames. If the variation of depth requires longer duration than 255 frames, it can be signaled using multiple pairs of SetDepthPos and ChangeDepthPos commands).
When the digital receiver has no capability to smoothly change the depth, the digital receiver may ignore, for example, the SetDepthPos command.
The writer (or author) of the caption will need to insert the second SetDepthPos command after the number of frames (fc) in order to inform receivers with limited capabilities of the final depth of the window.
The following is a description of a usage scenario of the above embodiments.
For example, a command sequence for simple pop-on captioning for receivers with limited capabilities is as follows.
a) DeleteWindow command which removes all windows excluding one displayed window.
b) DefineWindow command which defines a hidden window.
c) SetWindowAttributes command which customizes a hidden window.
d) Pen Commands & Caption Text commands
e) ClearWindows command which clears a displayed window.
f) SetDepthPos command which defines the depth position of the hidden window.
g) ToggleWindows command which defines toggling between the hidden window and the displayed window.
h) SetDepthPos command
i) Pen commands & Caption Text commands
j) SetDepthPos command
k) Pen commands & Caption Text commands
These and other commands may be sequentially used.
The following is a command sequence for simple pop-on captioning having commands for smooth change of the depths of caption windows according to the present invention. This command sequence is provided for receivers having improved performance.
a) DeleteWindow command
b) DefineWindow command
c) SetWindowAttributes command
d) Pen Commands & Caption Text commands
e) ClearWindows command
f) SetDepthPos command (where the depth value is applied to all windows if the aw_flag value is 1)
g) ChangeDepthPos command which defines smooth change of the depth position (where the depth value is also applied to all windows if the aw_flag value is 1)
h) ToggleWindows command
i) SetDepthPos command
j) Pen commands & Caption Text commands
k) ChangeDepthPos command
l) SetDepthPos command
m) Pen commands & Caption Text commands
n) ChangeDepthPos command
These and other commands may be sequentially used.
FIG. 11 illustrates another exemplary procedure for processing 3D caption data in the digital receiver according to the present invention.
The procedure of FIG. 11 may be a procedure subsequent to that of FIG. 4 described above. Thus, for details of the previous procedure, reference may be made to the above description of FIG. 4 and a detailed description thereof may be omitted herein.
When the graphics engine and/or OSD processor has received a ChangeDepthPos command, a start disparity value is used as a disparity value corresponding to a time point at which a corresponding 3D caption is initially displayed (S 1102 ). Here, the 3D caption may use a window ID such that a different window may be applied according to the aw_flag.
The graphics engine and/or OSD processor allows the caption window to be located at a depth corresponding to the end disparity after a number of frames corresponding to the frame count have elapsed (S 1104 ).
When frame rate conversion has occurred in the display in the implementation procedure of step S 1104 , the graphics engine and/or OSD processor appropriately corrects the frame count value taking into consideration an original frame rate and a final output frame rate. That is, if the original frame rate is 30 and the output frame rate is 240 in the display procedure, the end disparity is applied after a number of frames corresponding to 8×(frame count) have elapsed in the display rendering procedure (S 1106 ).
If the time point at which the caption window is initially displayed is “A” in the implementation procedure of step S 1104 , the graphics engine and/or OSD processor allows the disparity for the caption window after “A+(frame_count)/original_frame_rate)” to have the end disparity value. Here, in a time interval between “A” and “A+(frame_count)/original_frame_rate)”, the receiver performs processing for smooth transition in the caption window disparity to prevent rapid change in the caption window disparity (S 1108 ).
When the graphics engine and/or OSD processor changes the disparity every frame in the implementation procedure of step S 1108 , the same amount of change as (end_disparity-start_disparity)/(frame_count) occurs every frame. Accordingly, when such implementation is a burden on the performance of the receiver, the graphics engine and/or OSD processor gradually changes the disparity at intervals of t frames.
In the above procedure, if the aw_flag value is 1, this procedure is applied to all windows defined in the current service regardless of the window ID field. If the aw_flag value is 0, the above procedure is performed only on a caption window specified by the window ID field.
The following is a description of the above embodiments in association with performance of the digital receiver according to the present invention.
When the decoder is ideal, the decoder may interpret an SDP command as an offset relative to a DFn command for a right eye image. If the disparity value is corrupt or improper, the offset may be limited to the actual screen display space (This decoder will interpret the SDP command as an offset relative to the DFn command for the right eye image. If the disparity value is corrupted or otherwise improper, the offset will be limited to the actual screen display space).
This decoder may interpret the CDP command by moving the right image by a fraction of the difference between the current window disparity value and the end disparity value for each of the “number of frames” defined by this command. If the end disparity value is corrupted or improper, the final offset may be limited to the actual screen display space (This decoder will interpret the CDP command by moving the right image by a fraction of the difference of the current window disparity value and the end disparity value for each of the “number of frames” defined by this command. If the end disparity value is corrupted or otherwise improper, the final offset will be limited to the actual screen display space).
The window ID of the above commands is applied for the depth command and does not reset the current window value for other commands (The window ID of the above commands will apply for the depth command and does not reset the current window value for other commands).
The motion of the CDP command will commence on the display or toggle the window command to make the window visible. If the window is already visible, the action may commence immediately (The motion of the CDP command will commence on the display or toggle window command that makes the window visible. If the window is already visible, the action commences immediately).
If a new CDP command is issued before the previous CDP command is completed, the decoder may simply compute a new fractional movement toward the revised end disparity value (If a new CDP command is issued before the previous CDP command is completed, the decoder simply computes the new fractional movement toward the revised end disparity value).
A clear window command has no influence on the position or movement of the caption window. A delete or hide window command will move the offset to the end disparity value (A clear window command will have no affect on the position or movement of the caption window. A delete or hide window command will move the offset to the end disparity value).
The following is a description of static caption windows. This caption decoder does not dynamically move caption windows. SDP commands are not affected and are handled as with the ideal decoder (This caption decoder is not able to dynamically move caption windows. SDP commands are not affected and are handled as in the ideal decoder).
The decoder does not move the caption window on a continuous basis and therefore the CDP command is handled slightly differently (Since the decoder does not move the caption window on a continuous basis, the CDP command is handled slightly differently). The decoder may perform a delay action for the period of the “number of frames (The decoder will delay action for the period of “number of frames.”). Thereafter, the corresponding caption window will change to the end disparity value (After that time, the right caption window will move to the end disparity value). As described above, the end disparity value is subject to the limits of the display space (As above, the end disparity value is subject to the limits of the display space).
On the other hand, the 2D only decoder has no capability to process the SDP or CDP commands. That is, the decoder can process only simple commands and 2D images associated with captions. Accordingly, the SDP and CDP commands are ignored (This decoder has no capability to process the SDP or CDP commands. In this case, the decoder simply processes the standard commands as though the image were a standard 2D image. The SDP and CDP commands are ignored).
Various embodiments have been described above for carrying out the invention.
As is apparent from the above description, the digital receiver according to the present invention can provide 3D caption data while maintaining compatibility with legacy devices. In addition, when a plurality of 3D caption data is provided, the digital receiver can fully or individually control the plurality of 3D caption data. Even when disparity information of 3D caption data has rapidly changed, the digital receiver can perform processing so as to prevent the user from experiencing vertigo.
The present invention, which relates to a digital broadcast system that provides a 3D service, can be fully or partially applied to the digital broadcast system.
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The present description provides a digital receiver which provides 3D caption data and a method for processing 3D caption data in the digital receiver of the present invention. A method for transmitting a broadcast signal for 3D service according to one aspect of the present invention comprises the following steps: encoding 3D video ES including a 3D caption service; generating signaling information for signaling a 3D video service including the encoded 3D video ES; and transmitting a digital broadcast signal including the 3D video service and the signaling information, wherein said 3D caption service includes a first command code for generating left caption data and a second command code for indicating a disparity value for a caption window, and generates right caption data on the basis of the first command code and second command code.
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BACKGROUND OF THE INVENTION
Field of the Invention
Communications systems evolve more and more towards an Internet Protocol (IP)-based network. They typically consist of many interconnected networks, in which speech and data is transmitted from one terminal to another terminal in pieces, so-called packets. IP packets are routed to the destination by routers in a connection-less manner. Therefore, packets comprise IP header and payload information, whereby the header comprises among other things source and destination IP addresses.
For scalability reasons, an IP network uses a hierarchical addressing scheme. Hence, an IP address does not only identify the corresponding terminal, but additionally contains location information about this terminal. With additional information provided by routing protocols, routers in the network are able to identify the next router towards a specific destination.
One of the most commonly used tunneling mechanism is the IP(layer 3)-in-IP(layer 3) encapsulation, which refers to the process of encapsulating an IP-datagram with another IP header and may be used e.g. for Mobile IP. Mobile IPv6—also denoted MIPv6—(see D. Johnson, C. Perkins, J. Arkko, “Mobility Support in IPv6”, IETF RFC 3775, June 2004, available at http://www.ietf.org) is an IP-based mobility protocol that enables mobile nodes to move between subnets in a manner transparent for higher layers and applications, i.e. without breaking higher-layer connections. In other words, the mobile nodes remain reachable while moving around in the IPv6 internet network.
Usually, when a terminal powers on, it configures an IP address that is based on the IP address prefix of the access network. If a terminal is mobile, a so-called mobile node (MN), and moves between subnets with different IP prefix addresses, it must change its IP address to a topological correct address due to the hierarchical addressing scheme. However, since connections on higher-layers, such as TCP connections, are defined with the IP addresses (and ports) of the communicating nodes, the connection to the active IP sessions breaks if one of the nodes changes its IP address, e.g. due to movement. One possible protocol to address said problem is the MIPv6 protocol.
The main principle of MIPv6 is that a mobile node is always identified by its Home Address (HoA), regardless of its topological location in the internet, while a Care-of Address (CoA) of the mobile node provides information about the current topological location of the mobile node.
In more detail, a mobile node has two IP addresses configured: a Care-of Address and a Home Address. The mobile node's higher layers use the Home Address for communication with the communication partner (destination terminal), from now on mainly called Correspondent Node (CN). This address does not change and serves the purpose of identification of the mobile node. Topologically, it belongs to the Home Network (HN) of the mobile node. In contrast, the Care-of Address changes on every movement resulting in a subnet change and is used as the locator for the routing infrastructure. Topologically, it belongs to the network the mobile node is currently visiting. One out of a set of Home Agents (HA) located on the home link maintains a mapping of the mobile node's Care-of Address to the mobile node's Home Address and redirects incoming traffic for the mobile node to its current location. Reasons for deploying a set of home agents instead of a single home agent may be e.g. redundancy and load balancing.
Mobile IPv6 currently defines two modes of operation, one of which is bi-directional tunneling ( FIG. 1 ). The other mode is the route optimization mode ( FIG. 2 ), which will be discussed later. In using bi-directional tunneling, data packets sent by the correspondent node 101 and addressed to the home address of the mobile node 102 are intercepted by the home agent 111 in the home network 110 . IP-in-IP encapsulation is required because each data packet that is intercepted needs to be resent over the network to the Care-of Address of the MN 102 . Accordingly, each intercepted data packet is included as the payload in a new IP data packet addressed to the CoA of the MN 102 and tunneled to the MN 102 , which is located at the foreign network 120 . The start of the corresponding tunnel is the Home Agent 111 , which carries out the encapsulation, and the end is the mobile node 102 . It might also be possible that a local agent in the foreign network 120 receives messages on behalf of the mobile node, strips off the outer IP header and delivers the decapsulated data packet to the mobile node (not shown).
Data packets sent by the mobile node 102 are reverse tunneled to the home agent 111 , which decapsulates the packets and sends them to the correspondent node 101 .
Reverse tunneling means that packets are tunneled by the mobile node to the home agent in a “reverse” manner to the “forward” tunnel.
Regarding this operation in MIPv6 only the Home Agent 111 is informed about the Care-of Address of the mobile node 102 . Therefore, the mobile node sends Binding Update (BU) messages to the Home Agent. These messages are advantageously sent over an IPsec security association, and are thus authenticated and integrity protected.
FIG. 3 shows a diagram of an exemplary data packet exchange between a CN 101 and a MN 102 via the Home Agent 111 of the MN 102 , wherein the packet format during the communication is illustrated in detail. It is assumed that all communication between the CN and the MN is conducted via the MN's HA 111 , that is, no route optimization has been performed. Consequently, the IP header of a data packet transmitted from the CN to the MN contains the Home Address of the MN as destination address, and the IP address of the CN as the source address. In accordance with the destination address of the packet being the Home Address of the MN, the data packet is routed to the Home Network, and then to the Home Agent of the MN.
As explained above, upon receiving the data packet, the HA applies the IP-in-IP encapsulation based on MIPv6 procedures and sends the encapsulated packet to the MN. In other words, the HA tunnels the received data packets to the MN by applying the IP-in-IP encapsulation. More specifically, the HA adds another IP header to the packet, comprising its own address as the source address, and the Care-of Address of the MN as the destination address of the additional header. As apparent from FIG. 3 this augments the packet size with another 40 bytes.
Similarly, data packets that are returned by the MN are encapsulated with two IP headers. The outer header relates to the tunneling of the data packet to the HA, and accordingly includes the address of the HA as the destination address, and the Care-of Address of the MN as the source address. The inner IP header includes the CN's address as the destination, and the MN's Home Address as the source address.
In brief, Mobile IPv6 works as follows. A mobile node (MN) can have two addresses—a permanent home address (HoA) and a care-of address (CoA), which is associated with the network the mobile node is visiting. A home agent (HA) stores information about mobile nodes whose permanent address is in the home agent's network.
A node wanting to communicate with the mobile node uses the home address of the mobile node to send packets. These packets are intercepted by the home agent, which uses a table and tunnels the packets to the mobile node's care-of address with a new IP header, preserving the original IP header. The packets are decapsulated at the end of the tunnel to remove the added IP header and delivered to the mobile node.
As mentioned above, a mobile node can be registered at multiple home agents, for different reasons. When registered at multiple home agents, the mobile node has multiple home addresses and for each of those a care-of address can be specified. This can be used by a malicious host to construct bindings in such a way that loops will be created. An example is shown in FIG. 4 , where a loop exists consisting of three home agents. Packets destined for the mobile node get stuck in the loop and may create high load in the network. This could be used for denial of service attacks. Because of possibly encrypted packets, the loop detection is non trivial.
As explained above, encapsulation is the process of prepending a new header to the original packet. At encapsulation, the source field of the tunnel header is set to the address of the tunnel entry-point node, and the destination field with an IPv6 address of the tunnel exit-point. Subsequently, the tunnel packet resulting from encapsulation is sent towards the tunnel exit-point node.
The forwarding by the home agent as described above makes use of encapsulation.
Nested IPv6 encapsulation is the encapsulation of a tunnel packet. It takes place when a hop of an IPv6 tunnel is a tunnel. The tunnel containing a tunnel is called an outer tunnel. The tunnel contained in the outer tunnel is called an inner tunnel. Inner tunnels and their outer tunnels are nested tunnels.
In RFC2473, “Generic Packet Tunnelling in IPv6 Specification”, a method is described to limit nested encapsulation. Nested encapsulation is the encapsulation of an encapsulated packet.
Since each encapsulation adds a non-zero number of bytes to the packet, nested encapsulation is naturally limited to the maximum IP packet size. However, this limit is so large that it is not effective.
RFC2473 proposes a mechanism for limiting excessive nested encapsulation with a “Tunnel Encapsulation Limit” option, which is carried in an IPv6 Destination Options extension header accompanying an encapsulating IPv6 header, see FIGS. 9 and 10 .
From RFC2473: “The Tunnel Encapsulation Limit option specifies how many additional levels of encapsulation are permitted to be prepended to the packet—or, in other words, how many further levels of nesting the packet is permitted to undergo—not counting the encapsulation in which the option itself is contained. For example, a Tunnel Encapsulation Limit option containing a limit value of zero means that a packet carrying that option may not enter another tunnel before exiting the current tunnel.”
In case of the loop between Home Agents, a so called “recursive nested encapsulation” will occur, and the method in RFC2473 prevents that the packets loop forever, but it does not prevent packets to enter the loop. Thus it does not remove the loop.
A Tunnel Encapsulation Limit value can indicate whether the entry-point node is configured to limit the number of encapsulations of tunnel packets originating on that node. The IPv6 Tunnel Encapsulation Limit is the maximum number of additional encapsulations permitted for packets undergoing encapsulation at that entry-point node. The recommended default value is 4. An entry-point node configured to limit the number of nested encapsulations prepends a Destination Options extension header containing a Tunnel Encapsulation Limit option to an original packet undergoing encapsulation—see above.
If a Tunnel Encapsulation Limit option is found in the packet entering the tunnel and its limit value is non-zero, an additional Tunnel Encapsulation Limit option must be included as part of the encapsulating headers being added at this entry point. The limit value in the encapsulating option is set to one less than the limit value found in the packet being encapsulated.
In Mobile IP, mobile nodes that are away from home have a binding at the home agent that binds the mobile's node home address to its current care-of address. A mobile node that is registered at multiple home agents, could setup the binding in such a way that a loop exists. Packets destined for the mobile node would then never arrive at the mobile node, and might create a heavy traffic load between the home agents. This could be used for denial of service attacks. Because of possibly encrypted packets, the loop detection is non-trivial.
The goal is to detect encapsulation loops, so that the needed action to break the loop can be taken by the home agent. The difficulty is that packets get a new packet header and are possibly encrypted (as part of the encapsulation) at each home agent in the loop. Therefore, the receiving home agent cannot tell, without any other means, that this packet was originated at itself.
As mentioned, the home agents may encrypt packets during the loop. Because these are packets destined for the MN, only the MN can decrypt the contents. But in case of a loop, that packet will never arrive at the MN, so it is impossible to decrypt it (in general).
It should be noted that a loop detection solution that allows changes to the implementation of all the home agents in the loop, would be trivial. The home agents could just communicate with each other about the existence of loops.
The aim is that a solution should work together with unmodified home agents in the loop. At least one home agent in the loop is needed to use this invention.
SUMMARY OF THE INVENTION
The present invention has been made in consideration of the situation above and has as its object to detect loops while not needing to modify any of the existing hardware.
This object is solved by the invention as claimed in the independent claims. Preferred embodiments of the invention are defined by the dependent claims.
To achieve this object, the present invention provides a method and computer-readable medium for loop detection in data packet communication utilizing a tunnel in a network comprising a plurality of nodes. The method comprises the steps of, when a first node transmits a data packet, encoding an identification of the first node in at least two header fields of the data packet to be transmitted, and when the first node receives a data packet, analysing the at least two header fields of the data packet, deciding if a loop exists by determining if the data packet was sent by the first node itself, based on the analysis of the at least two header fields of the data packet.
According to an advantageous embodiment the first node is a home agent or a router.
According to another embodiment of the invention the at least two header fields are tunnel encapsulation limit fields of an extended IPv6 header.
In a further embodiment of the invention the step of analysing comprises comparing the at least two header fields of the data packet with the encoded identification of the first node. If the at least two header fields originate at the first node, it is decided that the loop exists, otherwise it is decided that no loop exists.
Another embodiment of the invention comprises the step of reducing the value of each byte in the tunnel encapsulation limit field by 1 in each node in the network that encapsulates the data packet further.
According to another embodiment the step of comparing comprises subtracting the individual bytes of the tunnel encapsulation limit from the individual bytes of the encoded identification of the first node, deciding that the loop exists if the resulting bytes are the same.
In another embodiment of the invention the data packet is a binding refresh advice packet.
Another advantageous embodiment of the invention further comprises the step of, upon decision that a loop exists, receiving a binding update within a given time from transmission of the binding refresh advice packet, deciding that no loop exists.
BRIEF DESCRIPTION OF THE DRAWINGS
Further features and advantages will become apparent from the following, and more particular description of the various embodiments of the invention as illustrated in the accompanying drawings wherein:
FIG. 1 depicts a model of a MIPv6 network including a tunnel;
FIG. 2 shows the routing between a CN and an MN;
FIG. 3 shows the headers used in MIPv6;
FIG. 4 shows that a loop can be created for a mobile, which is registered at multiple home agents;
FIG. 5 shows the main idea where a loop detection packet is originated at a home agent and eventually is received by this home agent;
FIG. 6 shows an example how a loop detection packet originated at a different home agent as the receiver can be detected;
FIG. 7 shows an attacker trying to mimic a loop, although none exists;
FIG. 8 shows an attacker trying to disable the loop detection;
FIG. 9 depicts the extended mobile IPv6 header; and
FIG. 10 shows the format of the tunnel encapsulation limit field.
DETAILED DESCRIPTION OF THE INVENTION
The following paragraphs will describe various embodiments of the invention, and illustrate further alternative configurations.
For exemplary purposes only most of the embodiments are outlined in relation to an IPv6 system and the terminology used in the subsequence sections mainly relates to the IPv6 terminology. However, the terminology used and the description of the embodiments with respect to a IPv6 architecture is not intended to limit the principles and ideas of the invention to such systems.
Also the detailed explanations given in the technical background section above are merely intended to better understand the mostly IPv6 specific exemplary embodiments described in the following, and should not be understood as limiting the invention to the describe specific implementations.
Although this invention targets loop detection between home agents, the key idea could be used for detecting other loops as well.
The main idea is to make use of existing technique as defined in RFC2473. That document defines a “tunnel encapsulation limit” field that can be used to limit the number of encapsulations that are allowed for that packet. The limit (a field containing 8 bits) is decreased by one at each entry of a tunnel. The main idea of this invention is to use multiple of these fields in one packet. By encoding a sender-ID into these fields, the original sender is able to detect that that specific packet was actually sent by itself, and this indicates a loop.
The “tunnel encapsulated limit” is part of an IPv6 extension header, and a standard IPv6 complying router (or home agent), reduces the limit by one, for each extension header in the packet. So, if the original sender-ID contains 4 bytes, 4 header extensions each with a 1-byte encapsulation limit, will be contained in the loop detection packet header.
Thus, all encoded sender-ID bytes will be decreased by a value, corresponding to the length of the loop, upon reception by the original sender. Note that using only 1 byte as the sender-ID will not be sufficient to detect the loop, since the sender would not be able to distinguish between its own ID and that of possible other home agent. So, at least 2 bytes are needed for the sender-ID; any additional byte decreases the possibility of a collision with other home agent IDs.
In FIG. 4 , an MN 102 is shown which is registered at three home agents 402 , 4004 , 406 . At each home agent it has set up a binding, from the MN's home address to its care-of address, in such a way that the bindings form a loop. Any packet destined for the MN 102 will get caught in the loop. This situation could be created by a malicious host, to generate heavy traffic on the links between the home agents.
This situation in clearly not desired and should be detected so that action can be taken. The main idea of this invention is illustrated in FIG. 5 .
In this figure, a loop exists at the home agents for packets destined for the MN 102 . In the figure it is assumed that HA 1 402 suspects a loop and starts the loop detection procedure. It does this by generating the “loop detection packet” with, in this case, four tunnel encapsulation limit options. HA 1 402 writes its own ID (13,54,30,8) into the packet, and sends it to the care-of address of the MN 102 as registered at HA 1 402 .
HA 2 404 , which can be a standard conform IPv6 home agent, processes this packet like any other packet for the MN 102 . Because the MN 102 is currently not at home at HA 2 404 , it encapsulates the packet and sends it to the care-of address as registered at HA 2 404 . By doing this, it decreases the tunnel encapsulation limit fields of the original packet. The tunnel encapsulation limit header options are copied from the original packet; the limit is decreased and placed as option headers in the new packet.
The result is that the original ID of HA 1 402 , is still inside the packet and is not encrypted. Its individual bytes are only decreased by one. HA 3 406 will do exactly the same as HA 2 404 , resulting in a packet arriving at HA 1 402 . Upon reception HA 1 402 , compares the received values with its own ID, and if all numbers are equal, this probably indicates a loop. The main idea of the loop detection is to compare the received number with the home agent's own ID. This is done by subtracting the individual parts (bytes) of both numbers. There are other computations possible to reach the same effect.
Next to subtraction, other mathematical procedures are possible to detect a loop. In the following one such method is described. Assume the home agent ID consists of the four numbers a1 . . . a4, and the received numbers in the packet are r1 . . . r4.
The first step is to calculate the differences between the individual numbers of the home agent ID, this is m1=a2−a1, m2=a3−a2 and m3=a4−a3.
Next the received numbers and the ID are summed: s1=a1+r1, s2=a2+r2, s3=a3+r3 and s4=a4+r4.
Again, the differences between the individual numbers of S is calculated: n1=s2−s1, n2=s3−s2 and n3−s4−s3.
Now, there is a loop if and only if:
n 1/ m 1=2
n 2/ m 2=2
n 3/ m 3=2
Thus if the division results in exactly 2, at all three divisions, then there is a loop, otherwise there is none.
Once a loop is detected the HA can simply delete the binding for that MN to break the loop. Packets destined for the MN will be discarded. Standard mobile IP time out mechanisms will eventually discard the bindings at the other home agents.
Multiple methods could be used to assign Ids to home agents for the loop detection method. A simple way would be to assign the ID manually or generate it randomly. Another possibility is to base the number on other numbers that uniquely define the HA like the home agents IP address.
Note that a home agent does not does not know beforehand which other home agents could be involved in a loop.
Therefore, there is a probability that another home agent in the loop uses exactly the same ID. However, the probability of cases of “ID-collision” could be made arbitrarily small by increasing the number of bits of the ID.
Even if the IDs of two home agents are different, a collision could occur. Consider the case where ID 1=5, 5, 5 and ID2=8, 8, 8. If a loop detection packet arrives with e.g. 2, 2, 2 the HA 1 might think that this packet originated at itself, while HA 2 thinks exactly the same.
FIG. 6 illustrates the case when HA 2 404 instead of HA 1 402 starts with the loop detection procedure. Because HA 2 404 started, it generated a loop detection packet with its own id encoded in it (13,54,20,6). When this packet arrives at HA 1 402 , the original numbers are all decreased by one. HA 1 402 now compares the received numbers with its own ID by subtracting all numbers individually. As shown in the figure, the subtraction produces the numbers 1,1,11,3, which are not all equal, and therefore HA 1 402 knows that this loop detection packet was not originated at HA 1 402 .
Because a home agent loop could be used by malicious hosts to create a Denial of Service attack on the home agents, the solution to detect the loops should be secure also. The main idea of loop detection as explained in the previous paragraphs still holds, but some additions are needed to make it secure.
Until now, we did not exactly define the loop detection packet. For the main idea, it basically is also not important what kind of packet is actually used. However, in the light of possible attackers, it becomes important. This has to do with the fact that an attacker may intervene with the loop detection process. There are basically two problems that need to be solved:
There is no loop, but an attacker makes the home agent believe there is one.
There is a loop but the attacker disables the detection.
FIG. 7 shows the scenario for the first case where HA 1 402 starts a loop detection procedure, by sending a loop detection packet to the MN 402 . There is however an attacker 702 that can listen to the packets send to the MN 102 . If this attacker 702 duplicates the loop detection packet back to the HA, the HA might falsely detect a loop.
The solution to the problem described above, consists of multiple elements. Firstly, the packet used for loop detection is a “Binding Refresh Advice” (actually this is a binding acknowledgement packet with an optional binding refresh advice) as per RFC 3557. With a binding refresh advice, a home agent is able to force a MN to refresh its binding before the normal end of its lifetime. The point in using this message is twofold: first, an unmodified MN is able to respond to this message, and secondly, it can respond securely to this request.
So the complete secure loop detection procedure from the home agent viewpoint is as follows:
If the home agent suspects a loop for a particular MN, is creates a Binding Refresh Request for this MN. The home agent includes its ID in the form of tunnel encapsulation limit option headers.
If a loop detection packet is received and the numbers in the packet match with the home agent ID, then this may indicate a loop or an attacker. To find this out, the home agent starts a timer. If within this time an authenticated Binding Update is received from the MN, then there is no loop. Otherwise there is a loop. Note that it is assumed that the Attacker cannot throw away packets going to the MN, nor packets coming from the MN.
The second security problem is that an attacker might set up a loop, but disables the detection. The principle is shown in FIG. 8 . If the attacker 702 pretends to be the MN 102 and sends the BU to the home agent, the home agent might think there is no loop.
This problem is already solved because of the use of authenticated “binding refresh advice” and the corresponding “binding update”. The attacker 702 can only send this binding update if it has the key of the MN, and therefore this second security issue is not considered to be a problem.
The main idea for loop detection could use any packet type for the detection procedure. Namely, if there is a loop, that packet will arrive back at the home agent, and can inspect it. However, as apparent from the above, for security the use of a binding refresh request has advantages in case of the existence of attackers. But other messages may fulfill this purpose also. What is important is that the home agent can verify that the reply from the MN came indeed from the MN and not from some other entity.
Further, the various embodiments of the invention may also be implemented by means of software modules which are executed by a processor for or directly in hardware. Also a combination of software modules and hardware implementation may be possible. The software modules may be stored in any kind of computer readable storage medium, for example RAM, EPROM, EEPROM, flash memory, registers, hard disks, CD-ROM, DVD, etc.
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The present invention relates to a method and computer-readable medium for loop detection in data packet communication utilizing a tunnel in a network comprising a plurality of nodes. The method comprises the steps of, when a first node transmits a data packet, encoding an identification of the first node in at least two header fields of the data packet to be transmitted, and when the first node receives a data packet, analyzing the at least two header fields of the data packet, deciding if a loop exists by determining if the data packet was sent by the first node itself, based on the analysis of the at least two header fields of the data packet.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] The present application claims priority from U.S. Provisional Application Ser. No. 60/215,905, filed Jul. 3, 2000.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to portable screen devices. In particular, the present invention relates to portable screen devices which provide a barrier against insects and privacy.
[0004] 2. Description of the Related Art
[0005] Screens have long been used in conjunction with doorways and windows to allow air to flow through the doorway or window while preventing insects and debris from entering. Generally, these screens are made from a flexible screen material which is mounted about its perimeter to the doorway or window frame. The mounting can be permanent or temporary, however, common to all of the previous devices is a mounting system for the entire perimeter of the screen device.
[0006] Screen devices are well known in the form of screens which are attached to openings such as doors and windows. Previously known screens generally are attached to doors and windows by using mounting means located about the perimeter of the door or window. For example, U.S. Pat. No. 5,427,169 issued to Saulters describes a garage door screen. The perimeter of the screen is attached to the garage door opening using Velcro® or another similar attachment means. While the screen can be removed from the garage door opening, it cannot be used in locations other than a garage door opening which includes the appropriate mounting means.
[0007] U.S. Pat. No. 3,763,917 shows a screen for garages, porches and similar locations. The screen is detachably mounted to the frame of the opening it is designed to protect. Again, this device can only be used in conjunction with a frame having the appropriate mounting hardware installed about its perimeter.
[0008] U.S. Pat. No. 2,246,663 shows a screen for outward opening casement windows. This screen uses clips to attach the screen to the window frame. Again, this device can only be used in conjunction with a window frame having the appropriate mounting means installed about the perimeter of the frame.
[0009] U.S. Pat. No. 5,271,449 shows an adjustable screen for garage doors or windows. The screen is detachably mounted to the perimeter of the door or window frame using a hook and loop fastener and, as shown in the previous devices, requires that mounting material be installed about the perimeter of the door or window frame.
SUMMARY OF THE DISCLOSURE
[0010] A portable screen device is described which includes at least one screen panel which is attached to a framed opening such as a window or doorway and suspended from the attachment system. Each screen panel may include a stabilizing means such as weights or a metal chain for stabilizing the bottom edge of each screen panel. The stabilizing means can be placed in a pocket formed by folding up the bottom edge of each screen panel. Each screen panel may consist of screen material which includes a frame around the outer edges of the screen. The frame can be made out of a durable, flexible fabric material. Hooks can be attached to the top edge of each screen panel. To hide the hooks, the top edge of each screen panels can be folded down and releasably attached to the panel below the hooks. A wire is threaded through the hooks and the ends of the wire are attached to the frame opening, using eyehook screws or the like, to suspend each screen panel in the opening. If desired, an apparatus, such as a turnbuckle, can be used to tighten the wire. If two or more screen panels are used, the panels can be connected along adjoining side edges using a releasable connection system such as snaps or hook and loop fastener.
[0011] It is therefore an object of the present invention to provide a portable screen device.
[0012] It is another object of the present invention to provide a portable screen device which provides a barrier against insects.
[0013] It is yet another object of the present invention to provide a portable screen device which provides privacy.
[0014] It is yet a further object of the present invention to provide a portable screen device which is easily moved to different locations as needed.
[0015] Finally, it is an object of the present invention to accomplish the foregoing objectives in a simple and cost effective manner .
DESCRIPTION OF THE DRAWINGS
[0016] [0016]FIG. 1 is an exploded front view of the preferred embodiment of the present invention;
[0017] [0017]FIG. 2 a is a cross sectional view of the preferred embodiment of the present invention taken along line II-II of FIG. 1 in the unfolded configuration;
[0018] [0018]FIG. 2 b is a cross sectional view of the preferred embodiment of the present invention taken along line II-II of FIG. 1 in the folded configuration; and
[0019] [0019]FIG. 3 is a front view of the preferred embodiment of the present invention in the installed configuration.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] The following detailed description is of the best presently contemplated modes of carrying out the invention. This description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating general principles of embodiments of the invention.
[0021] The present invention provides a portable screen device which provides screen protection for an opening such as a patio, deck or doorway. The device includes one or more screen panels. The screen panels may further include a flexible frame, made from a durable fabric or other material. If more than one screen panel is used, the panels are connected to each other along their side edges. This connection means can be any releasable method such as snaps or hook and loop fastener and can be attached to the fabric frame. The top edges of the screen panels include a system for suspending the panels. The suspension system can be hooks through which a wire is threaded. The suspension system is mounted in the opening. If the hook and wire suspension system is used, the wire can be mounted in the opening using screws and, if desired, a turnbuckle for tightening the wire.
[0022] A preferred embodiment of the portable screen device is shown in FIGS. 1 and 2. Two screen panels 10 are shown in this embodiment although it is clearly contemplated that different numbers of screen panels could be used. The screen panels 10 may be made from any material commonly used in the industry. Generally the screen material is durable and porous while preventing the entry of insects. Each panel 10 may be surrounded by a frame 12 made of a flexible material. This frame 12 provides added durability and an improved surface for attaching other items as described herein. The frame 12 is preferably made from a durable fabric material. Along the bottom edges of the panels 10 , a pocket 14 is formed by turning up a portion of the frame 12 . Inside this pocket 14 a stabilizer 16 , such as a metal chain, is placed in order to prevent or discourage movement of the panels 10 . The ends of the pocket 14 may be sewn closed to ensure that the stabilizer 16 remains in the pocket 14 . It is clearly contemplated that other types of stabilizers 16 could be used, that the pocket 14 might not be necessary or that stabilizers 16 might be unnecessary in a protected environment.
[0023] As shown particularly in FIGS. 2 a and 2 b , along the top edges of the screen panels 10 , another pocket 18 is preferably formed. In the most preferred embodiment, this pocket 18 is formed by turning down a portion of the top edges of the screen 10 or flexible frame 12 and releasably attaching the top edges to the screen 10 or to frame 12 . This releasable attachment can be snaps or hook and loop fastener or any other appropriate attachment.
[0024] The two screen panels 10 can be connected along their interior side edges by any releasable means such as snaps or hook and loop fastener 20 . This type of closing prevents entry by insects but allows the screen panels 10 to be opened if necessary. If there is no need to open the screen panels 10 , a single panel or permanent connection means can be used.
[0025] In order to hang the present invention within an opening, a suspension system is provided along the top edges of the screen panels 10 . The most preferred suspension system consists of hooks 22 attached to the top edges of the screen panels 10 . The hooks 22 are preferably located within the previously described pocket 18 formed along the top edges of the screen panels 10 . A wire 24 is threaded through the hooks 22 , or, if appropriate, the hooks 22 are clipped onto the wire 24 , and extends beyond the edges of the screen panels 10 . The wire 24 is then attached to eyehook screws 26 which are installed in the upper comers of the opening. A particularly preferred embodiment includes a method for tightening the wire 24 once the panels have been installed such as a turnbuckle 28 or other appropriate method.
[0026] If desired, the invention can include a method for strapping the screen panels 10 out of the way as needed. One method for accomplishing this is to provide a strap 30 attached to the external side edge of each panel 10 . This strap 30 can include a releasable attachment means such as snaps or hook and loop fastener 32 on its opposite sides. The strap 30 is pulled around the screen panel 10 and then hooked to itself thus holding the screen panels 10 away from the center of the opening.
[0027] While the description above refers to particular embodiments of the present invention, it will be understood that many modifications may be made without departing from the spirit thereof. The accompanying claims are intended to cover such modifications as would fall within the true scope and spirit of the present invention.
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A portable screen device provides an easily installed barrier against insects and a level of privacy. The device includes one or more screen panels the top edges of which are suspended from a wire. The ends of the wire are mounted in an opening such that the screen panels cover the opening. The bottom edges of the screen panels are weighted for stability and to prevent movement in the wind.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to a high pressure multi-stage pump which is especially adapted for pumping feedwater and the like, and wherein at each stage a differential pressure is developed by a regenerative turbine impeller.
2. Description of the Prior Art
A conventional high pressure regenerative pump comprises a main casing body, end bells, a shaft, an impeller at each stage, and liners at the opposide sides of each impeller.
Heretofore, interconnecting passages and suction and discharge connections have been integral with the main casing body, while the shaft bearing holders have been integral with the end bells (bearing brackets). As a consequence, the casing body and end bells have been of intricate design requiring complicated castings and machining to precise tolerances, and each variation in the number of stages required a new casting. Moreover, axial adjustment of the shaft, the impellers and the liners has been difficult; and excessive wear of the impellers and liners has been experienced. Also, replacement of end bearings and seals has required disconnection of the pump from the associated suction and discharge piping, and disassembly of the end bells. Additionally, coupling of the suction and discharge connections to suction and discharge piping, and decoupling of the pump, have not been as convenient as might be desired. Finally, primarily because of impeller positioning problems, high pressure regenerative pumps have been limited to no more than two stages.
SUMMARY OF THE INVENTION
The multi-stage high pressure regenerative turbine pump of the present invention is comprised of modular components which are of simple design and which are convenient and inexpensive to fabricate. The modular components may be used in the assembly of different pumps with an infinite number of stages.
The pump of the present invention comprises a casing having a plurality of successive-stage casing rings. A transfer plate is in intermediate abutment with each adjacent pair of casing rings, and has fluid passageway means presenting an entrance communicating with the interior of the earlier-stage casing ring and an exit communicating with the interior of the later-stage casing ring. A suction end casing section abuts the first-stage casing ring, a discharge end casing section abuts the last-stage casing ring, and the casing elements are suitably secured together. A shaft extends axially through the casing, and an impeller is keyed thereto within the confines of each of the casing rings.
In addition, liners are provided at the opposite sides of each impeller; they are separate from the casing, and are readily replaceable. Each impeller is spring biased against a locating collar secured to the shaft; this arrangement, while allowing emergency shifting of the impellers, minimizes wear of the impellers and liners. Bearing and seal holders are secured to the end casing sections adjacent the ends of the shaft; they are separate from the end casing sections, and are readily demountable to permit replacement of the shaft bearing and seal means without disturbing other elements of the pump. Suction and discharge connections are secured to the end casing sections; they are separate, and demountable, from the end casing sections; they can be each set in any of several different positions to accommodate different directions of suction and discharge piping; and the pump may be withdrawn from between the connections without disturbing the couplings of the latter to the suction and discharge pipes.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevational view of the suction end of a two-stage pump incorporating the principles of the present invention;
FIG. 2 is an elevational view of the discharge end of the pump of FIG. 1;
FIG. 3 is a longitudinal sectional view taken substantially along the line 3--3 in FIGS. 1 and 7 looking in the direction indicated by the arrows;
FIG. 3A is a longitudinal sectional view taken substantially along the line 3A--3A in FIGS. 1 and 7 looking in the direction indicated by the arrows;
FIG. 4 is a longitudinal elevational view of a two-stage pump in a partially disassembled condition, shows an exploded longitudinal elevational view of one of the demountable bearing assemblies, and shows modified embodiments of suction and discharge connections;
FIG. 4A is a sectional view of another modified embodiment of suction connection;
FIG. 4B is a sectional view of another modified embodiment of discharge connection;
FIG. 5 is a longitudinal sectional view of a four-stage pump;
FIG. 6 is a sectional view taken substantially along the line 6--6 in FIGS. 7 and 10 looking in the direction indicated by the arrows;
FIG. 7 is a transverse sectional view taken substantially along the lines 7--7 in FIGS. 3, 4 and 5 looking in the direction indicated by the arrows;
FIG. 8 is a transverse sectional view taken substantially along the line 8--8 in FIG. 5 looking in the direction indicated by the arrows;
FIG 9 is a transverse sectional view taken substantially along the lines 9--9 in FIGS. 3, 4 and 5 looking in the direction indicated by the arrows;
FIG. 10 is a side elevational view of a casing ring;
FIG. 11 is a partial edge elevational view taken substantially along the line 11--11 in FIG. 10 looking in the direction indicated by the arrows;
FIG. 12 is a side elevational view of one of a cooperating pair of liners;
FIG. 13 is a side elevational view of the other of a cooperating pair of liners;
FIG. 14 is a side elevational view of an impeller;
FIG. 15 is an edge elevational view of the impeller of FIG. 14;
FIG. 16 is a partial longitudinal sectional view taken substantially along the line 16--16 in FIG. 3 looking in the direction indicated by the arrows;
FIG. 17 is a longitudinal elevational view of a six-stage pump; and
FIG. 18 is a longitudinal elevational view of an eight-stage pump.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIGS. 1, 2 and 3, there is indicated generally by the reference numeral 20 a two-stage high pressure regenerative turbine pump embodying the principles of the present invention.
The pump 20 includes a casing or housing 22 comprised of a suction and casing section 24, a first-stage casing ring 26, a transfer plate 28, a second-stage casing ring 30, and a discharge end casing section 32. Mounted at the opposite ends of the casing 22 are a suction connection 34 and a discharge connection 36.
The suction end casing section 24 presents a planar radial wall portion or inlet side 38 and an outlet side 40. The casing section 24 is formed with an upper inlet port 42 which is open at the inlet side 38 and which merges with a generally arcuate channel 44 open at the outlet side 40. The casing section 24 is also formed with a central axial opening 46, and lower mounting feet 48. Projecting from the inlet side 38 is a radially inner axial annular flange 50, and projecting from the outlet side 40 is a radially outer axial annular flange 52.
As shown in FIGS. 3 and 10, the first-stage casing ring 26 presents an inlet side 54, an outlet side 56, and an interior cylindrical surface 58. The casing ring 26 is formed with three upper axial-through cutouts 60, 62 and 64 in the surface 58, and a center circumferential baffle web 66 extends across the cutout 62. The casing ring 26 is also formed with a center radial collar 68, a radially outer annular recess 70 at the inlet side 54, and a radially outer annular recess 72 at the outlet side 56. The inlet side 54 of the casing ring 26 abuts the outlet side 40 of the casing section 24, the casing ring recess 70 receives the casing section flange 52 with a seal ring 74 interposed therebetween, and the cutouts 62 and 64 communicate with the casing section inlet port 42 and channel 44.
As shown in FIGS. 3 and 7, the transfer plate 28 presents an inlet side 76 and an outlet side 78. The plate 28 is formed with a generally arcuate channel 80 open at the inlet side 76, and an axial-through opening 82 merging with a generally arcuate channel 84 open at the outlet side 78. The plate 28 is also formed with a radially outer axial annular flange 86 at the inlet side 76, a radially outer axial annular flange 88 at the outlet side 78, and opposed radial locating lugs 89 and 90. The inlet side 76 of the transfer plate 28 abuts the outlet side 56 of the casing ring 26, the transfer plate flange 86 is received in the casing ring recess 72 with a seal ring 91 interposed therebetween, the transfer plate channel 80 communicates with the casing ring cutouts 62 and 64, and the transfer plate opening 82 communicates with the casing ring cutout 60 (FIG. 3A).
The second-stage casing ring 30 (FIGS. 3 and 3A) is identical in construction to the first-stage casing ring 26, but is positioned 180° out of phase with the latter. With respect to the second-stage casing ring 30, the inlet side 54 abuts the outlet side 78 of the transfer plate 28, the casing ring recess 70 receives the transfer plate flange 88 with a seal ring 92 interposed therebetween, and the cutouts 62 and 64 communicate with the transfer plate channel 84.
The discharge end casing section 32, which is similar to the suction end casing section 24, presents an inlet side 94 and a planar radial wall portion or outlet side 96. The casing section 32, as shown in FIGS. 3, 3A and 9, is formed with an upper outlet port 98 which is open at the outlet side 96 and which merges with a generally arcuate channel 100 open at the inlet side 94. The casing section 32 is also formed with a central axial opening 102, and lower mounting feet 104. Projecting from the inlet side 94 is a radially outer axial annular flange 106 and projecting from the outlet side 96 is a radially inner axial annular flange 108. The inlet side 94 of the casing section 32 abuts the outlet side 56 of the casing ring 30, the casing section flange 106 is received in the recess 72 of the casing ring 30 with a seal ring 110 interposed therebetween, and the casing section channel 100 communicates with the cutout 60 of the casing ring 30 (FIG. 3A).
The elements of the casing 22 are maintained in assembled relation by a plurality of longitudinally extending circumferentially spaced apart bolts 112 which project through the collars 68 of the casing rings 26 and 30 and through the end casing sections 24 and 32.
As shown in FIG. 3, the suction connection 34 has a generally radial bore 114 presenting an outer threaded end 116 and an inner side opening 118 open at a planar radial wall portion 119. The connection 34 is secured to the casing section 24 by bolts 120 with a seal ring 122 interposed therebetween, the inner side opening 118 communicates with the inlet port 42, and the outer end 116 threadingly receives an inlet pipe 124. Correspondingly, the discharge connection 36 has a generally radial bore 126 presenting an outer threaded end 128 and an inner side opening 130 at a planar radial wall portion 131. The connection 36 is secured to the casing section 32 by bolts 132 with a seal ring 134 interposed therebetween, the inner side opening 130 communicates with the outlet port 98, and the outer end 128 threadingly receives an outlet pipe 136.
Extending axially through the casing 22 is a shaft 138 having an intermediate body section 140, a pair of seal sections 142 and 144 of reduced diameter, a pair of bearing sections 146 and 148 of further reduced diameter, and a drive end section 150 of still further reduced diameter adapted to be connected with a drive motor (not shown).
Keyed to the shaft 138 within the confines of the casing ring 26 is a first-stage turbine-type impeller 152 (FIGS. 14 and 15) having a hub portion 154, and keyed to the shaft 138 within the confines of the casing ring 30 is an identical but reversely oriented second-stage impeller 156 having a hub portion 158. Located at the outboard side of the impeller hub portion 154 is a lock collar 160, located intermediate of the impeller hub portions 154 and 158 is a lock collar 162, and located at the outboard side of the impeller hub portion 158 is a lock collar 164. Each lock or impeller-locating collar 160, 162 and 164 is held in place by a set screw 166 engaged with a flat 168 formed on the periphery of the shaft body section 140. In addition, spring washers 170 and 172 are respectively interposed between the impeller hub portion 154 and the lock collar 162, and between the impeller hub portion 158 and the lock collar 164.
Mounted intermediate of the suction end casing section 24 and the first-stage impeller 152 is a first generally annular liner 174, and mounted intermediate of the impeller 152 and the transfer plate 28 is a second generally annular liner 176. The first liner 174, as shown in FIG. 12, is formed with radial notches 178 and 180 interconnected by an annular groove 182, and with a radially outer annular flange 184. The second liner 176, as shown in FIG. 13, is substantially a mirror image of the liner 174. It, too, is formed with radial notches 186 and 188 interconnected by an annular groove 190, and with a radially outer annular flange 192. The pairs of notches 178, 180 and 186, 188 are respectively circumferentially aligned, the liners 174 and 176 are seated in the casing ring 26, the flanges 184 and 192 abut radially spaced outwardly of the periphery of the impeller 152, the notches 178, 186 communicate with the end casing section channel 44 and the transfer plate channel 80, and the notches 180, 188 communicate with the transfer plate opening 82.
Mounted intermediate of the transfer plate 28 and the second-stage impeller 156 is a first generally annular liner 194, and mounted intermediate of the impeller 156 and the discharge end casing section 32 is a second generally annular liner 196. The second-stage liners 194 and 196 are respectively identical in construction to the firststage liners 174 and 176, but are positioned 180° out of phase with the latter. With respect to the second-stage liners 194 and 196, the pairs of notches 178, 180 and 186, 188 are respectively circumferentially aligned, the liners 194 and 196 are seated in the casing ring 30, the flanges 184 and 192 abut radially spaced outwardly of the periphery of the impeller 156, the notches 178, 186 communicate with the transfer plate channel 84, and the notches 180, 188 communicate with the end casing section channel 100.
A seal ring 198 is interposed between the suction end casing section 24 and the liner 174; and seal ring 200 is interposed between the transfer plate 28 and the liner 194. For ease of machining and assembly, the thickness of each pair of liners is maintained a few thousandths of an inch less than the thickness of the associated casing ring. The seal rings 198 and 200 serve to compensate for such differences in thickness.
As shown in FIGS. 3 and 4, the bearing and seal mounting of the suction end of the shaft 138 comprises an annular bearing cartridge 204 presenting an external shoulder 206 and an internal shoulder 208. The inner end of the bearing cartridge 204 projects into the casing section opening 46 with a seal ring 210 interposed therebetween and with the shoulder 206 abutting the casing section flange 50. Arranged between the bearing cartridge 204 and the shaft bearing section 146 is a ball bearing unit 212 which is held against the shaft seal section 142 by a lock nut 214 and a lock washer 216. Mounted inboard of the ball bearing unit 212 is a spring washer 217. A cap member 218 abuts the outer end of the bearing cartridge 204, and bolts 220 secure the cap member 218 to the suction end casing section 24 for maintaining the bearing cartridge 204 in position. Also arranged between the bearing cartridge 204 and the shaft seal section 142 are seal means 222 which include a rotating seal unit 224, a seal seat 226, and a backup ring 228. These elements are axially located between a snap ring 230 which is retained in the bearing cartridge 204 and a sleeve 232 which is held in abutment with the shaft body section 140 by a snap ring 234. Disposed inwardly of the ball bearing unit 212 are a water slinger 236 and an inner housing cap 238.
As shown in FIGS. 3 and 16, the bearing end seal mounting on the discharge end of the shaft 138 comprises an annular bearing cartridge 240 presenting an externally threaded portion 242, an inner end 244 of reduced diameter, and an internal shoulder 246. The inner end 244 projects into the casing section opening 102 with a seal ring 248 interposed therebetween and an adjusting ring 250 is threaded on the threaded portion 242 and abuts the casing section flange 108. Arranged between the bearing cartridge 240 and the shaft bearing section 148 is a ball bearing unit 252 which is held against the shaft seal section 144 by a lock nut 254 and a lock washer 256. A cap member 258 abuts the ball bearing unit 252 which in turn abuts the shoulder 246, and bolts 260 secure the cap member 258 to the discharge end casing section 32 for maintaining the bearing cartridge 240 in position. The cap member 258 is provided with a central axial aperture 262 through which the shaft drive end section 150 projects. Also arranged between the bearing cartridge 240 and the shaft seal section 144 are seal means 264 which are identical to the seal means 222 but reversely oriented.
During assembly of the pump 20, the lock collar 164 is axially preset on the shaft 138, with the lock collars 160 and 162 serving to axially locate the impellers 152 and 156 relative to the shaft 138. The spring washers 170 and 172 maintain the impellers 152 and 156 in engagement with the lock collars 160 and 162, and yet allow emergency shifting of the impellers. Prior to securing of the cap member 258 in place, the adjustable ring 250 is rotated to adjust the axial position of the bearing cartridge 240, shaft 138, and impellers 152 and 156, relative to the casing 22. When the cap member 258 is secured in place, it maintains the bearing cartridge 240, shaft 138, and impellers 152 and 156, in the axially adjusted position. The spring washer 217 takes up bearing end play and prevents bearing skidding. The described positive location of the impellers 152 and 156 relative to the shaft 138 by collars and spring washers minimizes wear of the impellers and liners, and the overall mounting of the impellers and shaft facilities assembly and axial adjustment of the latter.
Referring to FIGS. 3 and 3A, when the shaft 138 and impellers 152 and 156 are rotating, the pump 20 operates as follows: First, fluid is admitted through the suction connection 34 and the suction end casing section 24; it flows through the bore 114, side opening 118, inlet port 42 and channel 44. Then, the fluid enters the periphery of the first pump stage, wherein a differential pressure is developed, and exits at the periphery adjacent the point of entrance; it flows within the cutouts 62 and 64 and channel 80, is drawn by the impeller 152 into the notches 178, 186 and the grooves 182, 190, and is directed outwardly of the notches 180, 188. The cutout 64, in conjunction with the cutout 62, serves to balance the flow of entering fluid to each of the liners 174 and 176, while the cutout 60 accommodates the flow of exiting fluid. Next, the fluid moves through the transfer plate 28 to a circumferential position 180° out of phase with respect to the entrance of the first pump stage; it flows through the opening 82 and the channel 84. Thereafter, the fluid enters the periphery of the second pump stage, wherein a differential pressure is further developed, and exits at a circumferential position 180° out of phase with respect to the exit of the first pump stage; it flows within the cutouts 62 and 64, is drawn by the impeller 156 into the notches 178, 186 and grooves 182, 190, and is directed outwardly of the notches 180, 188. Finally, the fluid is discharged through the discharge end casing section 32 and the discharge connection 36; it flows through the channel 100, outlet port 98, side opening 130 and bore 126.
The bearing and seal mountings (FIG. 3) at the ends of the shaft 138 facilitate not only initial assembly of the pump 20 but also replacement of the bearings and seals. For example, at the suction end of the shaft 138, removable of the bolts 220 and lock nut 214 permits the cap member 218, bearing cartridge 204, ball bearing unit 212 and seal means 222 to be withdrawn from the end of the shaft (and suitable replacements made) without disturbing any other elements of the pump. The suction-end bearing and seal means are shown removed in FIG. 4. Correspondingly, at the discharge end of the shaft 138, removal of the bolts 260 and lock nut 254 permits the cap member 258, bearing cartridge 240, ball bearing unit 252 and seal means 264 to be withdrawn from the end of the shaft (and suitable replacements made) without disturbing any other elements of the pump.
The provision of suction and discharge connections which are separate from the other elements of the pump 20 facilitates not only initial assembly of the pump but also mounting of the same. For example, as shown in FIGS. 1 and 2, each suction and discharge connection 34 and 36 may be secured to the adjacent end casing section in any one of three rotative positions (upwardly or laterally to either side). This arrangement accommodates a variety of installation orientations and minimizes installation space. Also, separate suction and discharge connections accommodates the use of different types of pipe-coupling arrangements. As previously described, the connections 34 and 36 threadingly receive the inlet and outlet pipes 124 and 136. As shown in FIG. 4, modified connections 34a and 36a are formed with sockets 266 and 268 which receive inlet and outlet pipes 124a and 136a that are welded therein. As shown in FIGS. 4A and 4B, other modified connections 34b and 36b are provided with flanges 270 and 272 which are adapted to be bolted and/or welded to pipe flanges at the end of inlet and outlet pipes (not shown). Additionally, removal of the connection bolts 120 and 132 permits the pump casing 22 (and pump elements assembled therewith) to be withdrawn radially from between the suction and discharge connections while the latter remain coupled to inlet and outlet pipes as shown in FIG. 4. This arrangement allows the pump to be demounted, repaired or adjusted, and remounted, without disturbing the connection-to-pipe couplings. Although the suction-end bearing and seal means are shown removed in FIG. 4, they need not be removed to allow demounting of the pump from the suction and discharge connections.
It will be appreciated that the end casing sections, casing rings, transfer plate, and liners are of simple design with no complicated cores, and may be readily cast and/or machined with practical tolerances. Moreover, the provision of modular components simplifies inventory when different pump models--that is, different pumps with varying mumbers of stages--are involved, and allows the use of common components in the assembly of different pump models.
For example, shown in FIG. 5 is a four-stage pump, shown in FIG. 17 is a six-stage pump, and shown in FIG. 18 is an eight-stage pump. The casing rings 26a-care identical in construction and orientation to the casing ring 26, while the casing rings 30a- c are identical in construction and orientation to the casing ring 30. The transfer plate 28' is identical in construction to the transfer plate 28, but is positioned 180° out of phase with respect to the latter (compare FIGS. 7 and 8); the transfer plates 28a-c are identical in construction and orientation to the transfer plate 28; and the transfer plates 28'a-b are identical in construction and orientation to the transfer plate 28'. The liners within the casing rings 26a-c are identical in construction and orientation to the liners within the casing ring 26, while the liners within the casing rings 30a-c are identical in construction and orientation to the liners in the casing ring 30. With the principal exception of the shafts and casing bolts (which vary in length), all components of even-stage pumps over two stages are common to the components of a two-stage pump. Each associated casing ring, impeller, set of liners, locating collar, and spring means, together comprise a module which functions as one stage of the pump.
In all pumps, the exit of the fluid passageway means of each transfer plate is located X° out of phase with respect to the entrance of the fluid passageway means of the earlier-stage liners, and the exit of the fluid passageway means of each later-stage liners is located X° out of phase with respect to the exit of the fluid passageway means of the earlier-stage liners. In even-stage pumps, X is equal to 180; in odd-stage pumps, X is equal to 360 divided by the number of stages. Thus, the forces acting on the fluid are radially balanced.
The stages of each pump are connected in series, and the differential pressure developed in each stage is substantially uniform. Hence, the total differential pressure developed by a pump with a given number of stages is approximately equal to the differential pressure developed in one stage multiplied by the number of stages.
While there have been shown and described preferred embodiments of the present invention, it will be understood by those skilled in the art that various rearrangements and modifications may be made therein without departing from the spirit and scope of the invention.
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The segmented casing has a plurality of successive stage casing rings, a transfer plate intermediate each adjacent pair of casing rings, a suction end casing section, and a discharge end casing section. A shaft extends axially through the casing, and is supported and sealed at its ends by demountable bearing and seal means. Each casing ring encloses a complete stage containing an impeller which is spring biased into engagement with a locating collar secured to the shaft, and a pair of replaceable liners which are arranged at the opposite sides of each impeller. Each casing ring, impeller, set of liners, locating collar, and spring means, together comprises a module which functions as one stage of the pump. A pump is comprised of two or more modules which are connected internally by a shaft and externally by draw bolts, and which are contained by the suction and discharge end casing sections. Suction and discharge connections are demountably secured to the casing in any one of several rotative positions.
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CROSS REFERENCE TO RELATED APPLICATIONS
This patent application claims the benefit of U.S. Provisional Patent Application No. 61/405,270 filed Oct. 21, 2010, the entirety of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an electrical connector. In particular, the present invention relates to an electrical connector having an improved means for sealing the connector from the environment, and a method for forming such a connector.
2. Background of the Related Art
Turning first to FIGS. 1-3 , shown therein is a conventional connector 1 for use in harsh environments. Traditional connectors 1 and modules include M38999, M81714, M12883, and M5105 connectors, and the like. The connector 1 is built with a wire sealing grommet 11 made of silicone. The grommet 11 includes cavities 12 having holes 13 , the holes 13 configured to accept wires 14 inserted therethrough. The holes 13 in the grommet 11 have a diameter that is typically less than the diameter of the wires 14 so that, upon insertion of a wire 14 into the connector 1 through a hole 13 , a tight seal is created between the wire 14 and the grommet 11 . As shown in FIG. 2 , when holes 13 do not have wires 14 inserted therethrough, separate plastic sealing plugs 15 are used to prevent moisture and debris from entering the cavities 12 and potentially damaging the connector 1 . The sealing plugs 15 come in various sizes, which depend on the diameter of the cavities 12 . Installing these sealing plugs 15 is time consuming. The sealing plugs 15 add weight to the connector 1 , which is undesirable. Furthermore, the sealing plugs 15 have a potential to fall out of the connector 1 , making the protection offered by the sealing plugs 15 unreliable. FIG. 3 is a more detailed view of the grommet 11 having unfilled contact cavities 12 .
U.S. Pat. No. 4,629,269 to Kailus, the entirety of which is incorporated herein by reference, describes a connector insert having pockets that are sealed by a membrane, which is molded integral with the insert. Because the membrane described in that patent is integral with the insert, the membrane necessarily must be made of the same material as the insert. However, the material used for the insert may not be optimal for use as a membrane. Similarly, the material that may be optimal for use as a membrane is not necessarily appropriate for use as a connector insert. Consequently, the membrane may shear when a wire or connector is inserted through it, and pieces of the membrane may interfere with the operation of the connector. In addition, the color of the material used for the insert may not be optimal for use as a membrane, and vice versa.
Accordingly, there exists a need to provide a lightweight electrical connector for use with a selectable number of wires, and a method of forming the same, in which the connector is protected against potential damage caused by moisture or other harmful substances in the environment, in which the disadvantages associated with the use of sealing plugs is avoided, and in which the types of materials used to form the sealing membranes and other connector components may be optimized depending on the application for which the connector is desired.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide an electrical connector in which the number of wires received by the connector is selectable.
It is another object of the present invention to provide an electrical connector in which the connector is protected from the environment.
It is yet another object of the present invention to provide an electrical connector that overcomes the disadvantages of the use of sealing plugs, including increased connector weight, increased installation time, and unreliable protection.
It is yet another object of the present invention to provide an electrical connector in which the type of material used to form the connector body and the type of material used to seal the connector from the environment may be optimized.
Those and other objects of the present invention are accomplished, as embodied and fully described herein, by a connector, and a method for comprising the same, the connector comprising: a connector body having a surface, said connector body comprising a first material; at least one cavity formed in the surface of the connector body; and a sealing membrane received in the at least one cavity, said sealing membrane comprising a second material different from the first material.
The connector of the present invention may be configured to receive a wire conductor that pierces the sealing membrane, and the sealing membrane may form a seal around the wire conductor without shearing off when pierced by the wire conductor. The sealing membrane may adhere to the cavity, and may be formed separately from the connector body.
With those and other objects, advantages, and features of the invention that may become hereinafter apparent, the nature of the invention may be more clearly understood by reference to the following detailed description of the invention, the appended claims, and the several drawings attached herein.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a conventional connector.
FIG. 2 is a perspective view of a conventional connector having wire conductors and sealing plugs received therein.
FIG. 3 is a detailed view of the conventional connector depicted in FIG. 1 .
FIG. 4 is a perspective view of a connector in accordance with the present invention, the connector having cavities with sealing membranes received therein.
FIG. 5 is a top plan view of a connector in accordance with the present invention.
FIG. 6 is a cross-sectional view of the connector depicted in FIG. 5 .
FIG. 7 is a top plan view of a connector in accordance with the present invention.
FIG. 8 is a cross sectional view of a through-hole and a cavity in accordance with the present invention.
FIG. 9 is a cross-sectional view of the connector depicted in FIG. 5 .
FIG. 10 is a perspective view of a connector in accordance with the present invention, the connector having cavities with sealing membranes received therein, and wire conductors that pierce the sealing membranes.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In describing a preferred embodiment of the invention illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. However, the invention is not intended to be limited to the specific terms so selected, and it is to be understood that each specific term includes all technical equivalents that operate in similar manner to accomplish a similar purpose. It is further understood that the invention may be embodied in other forms not specifically shown in the drawings.
Turning to FIG. 4 , shown therein is a connector 10 having a grommet 20 in accordance with the preferred embodiment. The grommet 20 is part of the connector body 21 , and may be formed separately from, or integrally with, the connector body 21 . The grommet 20 has a number of cavities 22 positioned about the surface of the grommet 20 . A central through-hole 24 is positioned at the center of each of the cavities 22 . Each through-hole 24 extends through the grommet 20 . A silicone membrane 30 is received in each of the cavities 22 .
FIG. 5 is a top plan view of the grommet 20 showing the cavities 22 and through-holes 24 . The number and position of the cavities 22 shown in FIG. 5 is exemplary only, and more or fewer cavities 22 may be provided. In the preferred embodiment shown in FIG. 5 , the cavities 22 are circular. However, in other embodiments, the cavities 22 may have different shapes and sizes.
FIG. 6 is a cross-sectional view of the grommet 20 taken along line B-B of FIG. 5 , before the silicon membrane 30 is inserted into the cavities 22 . FIG. 7 is a top view of the grommet, showing the cavities 22 and through-holes 24 .
FIG. 8 is a cross-sectional view showing a through-hole 24 and a cavity 22 , and FIG. 9 is a cross-sectional view taken along line A-A of FIG. 5 . As shown in FIGS. 6 , 8 , and 9 , the grommet 20 has a 3-riser seal 23 , which has three small cavities 22 , 22 a , 22 b . An electrical wire conductor 25 , as shown in FIG. 10 , extends through the 3-riser seal 23 , and the 3-riser seal 23 forms a seal around the wire conductor 25 . In the embodiment shown in the figures, the membrane 30 substantially fills the topmost cavity 22 , which is located at the surface of the grommet 20 . Accordingly, the membrane 30 is directly accessible at the surface of the grommet 20 . The membrane 30 material is selected to fill the top cavity 22 , but not pass through the through-hole 24 into the lower cavities 22 a , 22 b.
Turning to FIG. 10 , insulated wire conductors 25 are shown positioned in the cavities 22 . When a wire conductor 25 is inserted into the grommet 20 , the wire conductor 25 pierces the membrane 30 to form an opening 32 in the membrane 30 . The wire conductor 25 then passes through the lower cavities 22 a , 22 b of the 3-riser seal 23 to mechanically and electrically connect with the connector 10 . Preferably, the wire conductor 25 connects to a contact within the connector 10 . The membrane 30 adheres to the outside surface of the wire conductor 25 and forms a seal around the wire conductor 25 about the opening 32 .
The formation of the membrane 30 , and the receipt of the membrane 30 in the cavity 22 , will now be explained. The membrane 30 is added to the cavity 22 after the grommet 20 is formed. The membrane 30 is therefore a separate element that is added to an existing grommet 20 . The membrane 30 is initially in the form of a liquid, which is placed into each of the cavities 22 of the grommet 20 by using a syringe or other dispensing device. The liquid substantially fills the entirety of each cavity 22 , but the viscosity and surface tension of the liquid prevent the liquid from extending beyond the top of each cavity 22 . Once in place, the membrane 30 substantially cures within an hour, and fully cures within about 72 hours. The membrane 30 forms an air tight seal of the cavity 22 and the interior of the grommet 20 . Preferably, a membrane 30 is formed over all of the cavities 22 of the grommet 20 , whether or not it is know whether a particular cavity 30 will receive a wire contact 25 .
In accordance with the preferred embodiment, the membrane 30 is a self-leveling silicone adhesive coating which adheres to a plastic grommet 20 . The membrane 30 is relatively viscous, with a preferred viscosity of about 30,000-40,000 cps. The membrane 30 is relatively soft, with a preferred hardness of about 25 durometer, shore A. The membrane 30 is sufficiently flexible to form a seal about the wire conductor 25 , yet also allow the wire conductor 25 to pierce the membrane 30 without having pieces of the membrane 30 shear off into the connector 10 . The wire conductors 25 easily penetrate the membrane 30 , and the membrane 30 provides a consistent puncture, irrespective of the material and properties of the grommet 20 . Accordingly, the membrane 30 material can be optimized for its purpose of providing an air tight or fluid tight seal which can be punctured without shearing. And, the grommet 20 material can be separately optimized for its purpose for any given application, which may vary substantially from the purpose of the membrane 30 .
The membrane 30 is also preferably translucent, so that it is easily visible when it is located in the cavity 22 . Because the membrane 30 is clear, the user is able to see the cavity 22 and the through-hole 24 , so that the wire conductor 25 may be easily positioned over and inserted into the through-hole 24 . An example of the silicone appropriate for use as the membrane 30 is offered by Silicone Solutions of Twinsburg, Ohio, product number SS-6001.
The invention includes a process in which a clear silicone membrane 30 is adhered to a wire sealing grommet 20 to plug some, or preferably all, contact cavities 22 of a grommet 20 . The membrane 30 is punctured when a wire conductor 25 with crimped contacts at its ends is inserted into the connector 10 . If the contact cavities 22 are not occupied by wire conductors 25 , then those cavities 22 remain sealed, so that sealing plugs 15 are not needed. The application of the membrane 30 can be incorporated into all connectors 10 with wire sealing grommets 20 . The step of sealing the cavities 22 is separate from the formation of the connector body 21 and/or the grommet 20 . Accordingly, the type of material used to form the connector body 21 and/or the grommet 20 and the membrane 30 may each be optimized for the particular application for which the connector 10 is desired. Additional, advantages of the present invention include that the connector 10 does not require sealing plugs 15 , the connector 10 is light weight, the membranes 30 prevent the entry of foreign object debris into the connector 10 , and the added installation time required to install sealing plugs 15 in the connector 10 is eliminated.
In the embodiment shown in FIGS. 4-10 , the grommet 20 has a length of about 1.0 inches, a width of about 0.6 inches, and a thickness of about 0.3 inches. The cavities 22 each have a diameter of about 0.1 inches, and the through-holes 24 each have a diameter of about 0.03 inches. The connector 10 , therefore, may receive wire conductors 25 having diameters ranging from about 0.03 inches to 0.1 inches. These dimensions are provided for exemplary purposes only, and are not intended to limit the scope of the invention. In the preferred embodiment, the connector 10 includes a grommet 20 as discussed above. However, other types of connectors and devices may be used without departing from the scope of the invention.
The foregoing description and drawings should be considered as illustrative only of the principles of the invention. The invention may be configured in a variety of shapes and sizes and is not intended to be limited by the preferred embodiment. Numerous applications of the invention will readily occur to those skilled in the art. Therefore, it is not desired to limit the invention to the specific examples disclosed or the exact construction and operation shown and described. Rather, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.
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A connector includes a connector body having cavities with through-holes disposed therein. Sealing membranes are received in the cavities and serve to protect the connector from the environment. Wire conductors may pierce the sealing membranes, and may be received by the through-holes of the cavities in the connector. In cavities in which wire conductors have been received, each sealing membrane forms a seal around a corresponding wire conductor. The connector body is formed from a first material, and the sealing membranes are formed from a second material, different from the first material.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the priority of the European Patent Application No. 09405097.8, filed on Jun. 5, 2009, the subject matter of which is incorporated herein by reference.
BACKGROUND
[0002] The invention relates to a production line for producing books comprising a book casing and a therein encased book block. The production line comprises a casing-in machine arranged at the conveying end of the production line, used for encasing a book block inside a book casing, and a processing section. The processing section comprises additional processing stations with processing devices assigned at partial distances or clocking intervals along the processing section. A book block can be advanced along the processing stations of the processing section for processing a book block spine. The processing stations comprise, in the conveying direction of the book blocks, a feed station for supplying the processing section with book blocks, a takeover station for taking over the book blocks, an adhesive-application station for spreading adhesive onto the book block spines, a backing station for attaching a backing strip and, if applicable, at least one headband, as well as a pressing station for pressing the backing strip or a headband against the book block spine, all arranged in the above sequence. The book blocks can be supplied successively and in a clocked manner to the processing stations with the aid of a conveyor and with the spines facing the processing devices.
[0003] For structural and arrangement reasons, the partial distances, also called the clocking intervals, between the processing stations are normally uniform along a conveying section for the takeover station, the following adhesive application station and the backing or headband-application station, but are farther apart by approximately 40 mm than the regular partial distances or clocking intervals for the conveying section assigned to the feed station.
[0004] Book production lines of this type are disclosed, among other things, in German patent document 43 34 224 A1, German patent document 43 34 225 A1, Swiss patent document 694 016 A5 and European patent document 1 894 739 A1.
[0005] With the disclosed book production lines, the conveying device and the processing stations are connected to a central drive motor. This arrangement requires a high driving power and results in high mass moments of inertia leading to the use of heavy gears and other involved drive elements. In recent years, the market for printed products, especially books, has shifted to extremely small editions of short-run productions for which the use of individual drives with angle of rotation controlled motors is suitable. Among other things, these motors offer the advantage that complete conveying sections can be stopped in case of a malfunction or that only the remaining production run can be processed out. Book blocks which are located downstream of the malfunction location on the production line can be processed further, meaning the portion of the production line that follows the malfunction can be emptied. As a result, waste material is noticeably reduced for very small editions, thus advantageously impacting the costs.
[0006] A traditional book production line normally comprises three conveying sections along a conveying line. The first conveying section is a feed or transfer section in which the book blocks are conveyed in a clocked manner, aligned and then transferred to the second conveying section for additional processing stations that follow in the downstream direction.
[0007] The second conveying section provides additional processing stations, as seen in the conveying direction, with a takeover station in which the book blocks are respectively positioned with the aid of a device on the feed section before being picked up by the movable chain mouth of side-by-side circulating chain conveyors that form the additional conveying section for the additional processing stations. The adhesive-application station, the backing station and the pressing station are located along this conveying section, as seen in conveying direction, wherein the adhesive is applied while a book block is moving through and after it is picked up by the chain conveyor, and wherein the subsequent backing and pressing operations occur successively while the book block is stopped.
[0008] The third conveying section is formed by the casing-in machine, in which six conveying elements circulate, for example in the form of a bucket conveyor.
[0009] The processing of small editions, for example involving 1 to 20 copies of book blocks of the same thickness, requires a relatively high share of the total expenditure for the set-up or conversion time. With traditional, standard book production lines, the requirements for producing a single-book edition can only be realized with difficulty and at high cost.
SUMMARY
[0010] It is an object of the present invention to create a book production line that makes possible a considerable improvement in the efficiency of the book production line when processing small editions of books having different thicknesses.
[0011] The above and other objects are accomplished according to one aspect of the invention wherein there is provided a production line for producing books including a book casing and a therein encased book block which, in one embodiment, includes a casing-in machine, arranged at a conveying end of the production line, to encase a book block in a book casing. The production line further includes a processing section upstream of the casing-in machine. The processing section includes processing stations arranged at clocking intervals along the processing section to process a book block spine. The processing stations include processing devices. The processing section includes, in sequence of the conveying direction of the book blocks, a first processing station group. The first processing station includes a feed station to supply book blocks to the processing section. The processing section further includes a second processing station group including, in sequence of a conveying direction of the book blocks, a transfer station to take over the book blocks, an adhesive-application station to apply adhesive to the book block spines, a backing station to attach a backing strip, and a pressing station to press the backing strip against the book block spine. The production line further includes a conveyor to successively supply the book blocks in clocked operation to the processing stations with the book block spines exposed and pointing upward toward the processing devices. The conveyor includes a first conveying section assigned to the first processing station group, the first conveying section including a first individual drive. The conveyor further includes a second conveying section assigned to the second processing station group, the second conveying section including a second individual drive. The production line further includes a control unit operatively connected to the first individual drive and second individual drive to change the clocking interval length along the processing section.
[0012] As a result, the length of the clocking intervals can be changed along the conveying section assigned to the processing stations.
[0013] A conveyor for the casing-in machine may be synchronously driven with the clocking rate of at least one of the conveying section for the feed station or the conveying section for the processing stations in order to coordinate the book production line.
[0014] The clocking interval length along the conveying section between the processing stations may be adjustable or re-adjustable to multiple lengths to achieve a higher performance efficiency.
[0015] With the herein described book production line, the clocking interval can be adjusted or re-adjusted to twice the length along the conveying section assigned to the processing stations, thereby avoiding any change in the coordination of the conveying sections.
[0016] Of course, it makes sense if the conveying sections for the processing stations and the feed station in which the book blocks are integrated into the process have approximately the same or different clocking interval lengths for large as well as small editions.
[0017] For the sake of simplicity, a multiple-length clocking interval on the conveying section assigned to the processing stations can be triggered via the control unit, based on a specific circulation number of uniformly thick book blocks.
[0018] The control unit may therefore be connected to a program and data memory for controlling the course of the processing of one or a plurality of successively following book block editions.
[0019] A change in the clocking interval length along the conveying section assigned to the processing stations to a clocking interval several times longer may occur for small editions ranging from one to five hundred book blocks so performance efficiency is improved.
[0020] The conveying section assigned to the processing stations of the processing section, arranged upstream of the casing-in machine as seen in book block conveying direction, may comprise alternately arranged processing stations designed for processing book blocks which are stopped or processing stations for processing book blocks that are moving through, to achieve a higher performance efficiency.
[0021] The end of the conveying section that is assigned to the processing stations in conveying direction of the book blocks, may therefore be a processing station which takes over the book blocks while the book blocks are stopped. The processing stations may then achieve a favorable clocking interval arrangement with an uneven clocking interval length between the conveying sections.
[0022] The book production line may be embodied so the conveying section that is assigned to the processing stations can be adjusted or re-adjusted during the processing of the book blocks.
[0023] It has proven useful if the individual drives for the conveying sections assigned to the processing stations and the feed station, respectively the casing-in machine, are provided with angle of rotation controlled electric motors, also called servo motors, which are operatively connected to the control unit, thus also resulting in an efficient structural design.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The present invention will be more readily understood from the following detailed description when read in conjunction with the accompanying drawings, in which:
[0025] FIG. 1 A perspective view of a schematically shown book production line for the processing book blocks at clocked intervals along a processing section which ends in a casing-in machine; and
[0026] FIG. 2 The book production line according to FIG. 1 with multiple clocked interval processing along the processing section.
DETAILED DESCRIPTION
[0027] FIG. 1 schematically shows a book production line 1 for producing books 4 comprising a book casing and a therein encased book block 3 . The conveying end of the book production line 1 is formed by a processing station which is also referred to as casing-in machine 5 and is described, for example, in European patent documents 1 780 037 A1 and 1 780 038 A1, as well as in the German patent document 19729529, the disclosures of which are incorporated herein by reference.
[0028] The casing-in machine 5 is used for applying adhesive to the outside surfaces of the book block 3 and for pressing a book casing 2 against the adhesive-coated outside surfaces of a book block 3 . For this, the casing-in machine is provided with a bucket-type conveyor 6 , having a traction device that circulates in a vertical plane and thereto attached, jib-like extending saddle plates 8 for holding and transporting the book blocks 3 which are supplied by the processing section 20 .
[0029] FIG. 1 furthermore shows the instantaneous position of six saddle plates 8 along the illustrated movement path where they have a nearly horizontal upper edge for accommodating the book blocks 3 . The book blocks 3 are moved in the conveying direction F of the book blocks 3 along the processing section 20 and over a block divider (not shown herein) with the opened front, also called the fore edge, pointing downward. The block divider spreads out each book block 3 in the center so the book block 3 is in a position for takeover by the conveyor 6 in which the saddle plates 8 take over the book blocks by dipping from below into the slightly spread-out book blocks 3 .
[0030] Following this, each book block 3 now straddling the saddle plates 8 moves vertically upward through an adhesive-application device, not shown herein, in which a book casing 2 supplied on the side of a pressing device (not visible herein) is pressed against the adhesive-coated outside surfaces of a book block 3 , also called the fly leaves of a book block 3 . Further along the conveying path of the casing-in machine 5 , the just produced books 4 reach a delivery station 9 where they are taken over by a delivery element 10 and are deposited on a delivery belt, not shown herein.
[0031] Arranged upstream of the casing-in machine 5 is a processing section 20 , along which additional processing stations are arranged at regular partial distances, also called clocking interval lengths. The processing stations include processing devices for processing a book block spine 21 . As seen in conveying direction F for the book blocks 3 , a feed station 13 with a feeding device 14 for supplying the following processing station is arranged at the start of the processing section 20 .
[0032] The clocked feeding of the book blocks 3 is realized, for example as shown in FIGS. 1 and 2 , with the aid of a star rotor 15 driven around an axis extending parallel to the conveying direction F at the clocking rate of the conveying section 16 for the feed station 13 . The star rotor 15 is provided along the circumference with six holding compartments for respectively supplying one book block 3 with its fore edge leading. The star rotor 15 deposits the book block 3 respectively with the fore edge onto a guide surface (not shown herein) where it is transported in synchronization with the clocking rate of the processing section 20 by a finger. The finger acts upon the rear edge of the book block and is positioned on a conveying chain (not visible) that is assigned to the feed station 13 , respectively a feed device 14 . The feed station 13 , respectively the feed device 14 , forms a separate feed section 16 which advances by several clocking intervals for transferring the book blocks 3 to the following processing station, a takeover station 17 of a conveying section 18 of the processing section 20 , which follows in conveying direction F of the book blocks 3 .
[0033] The separate conveying sections 16 , 18 are provided with separate drives 22 , 23 which are operatively connected to a joint control unit 24 . The individual drives 22 , 23 can be embodied as geared motors with an angle of rotation controlled electric motor and can be controlled individually or separately by the control unit 24 . That is to say, the conveying sections 16 , 18 can be operated with differently long clocking intervals. For the matter at hand, the conveying section 18 , arranged downstream of the conveying section 16 for the feed station 13 , as seen in conveying direction F of the book block 3 , can be adjusted or re-adjusted to clocking intervals which are multiple times, for example two times, longer than is provided between the processing stations. A slight difference in the clocking interval length between the conveying sections 16 and 18 , for example a clocking interval length that is longer by 40 mm in the conveying section 18 as compared to the conveying section 16 , does not impact the functions or movements of the processing section 20 .
[0034] To synchronize the clocking intervals over the complete book processing line 1 , it may be useful if the conveyor 6 that is assigned to the casing-in machine 5 is synchronously operated with the clocked conveying speed of one of the two or both conveying sections 16 , 18 . The transfer of the book blocks 3 from the conveying section 16 to the conveying section 18 can be realized, for example, with a conveying clamp 19 as described in European patent document 09405082.0, the disclosure of which is incorporated herein by reference, which transfers the book block 3 over two clocking intervals to the conveying section 18 . The conveying section 18 , which is distinguished by the processing of a book block spine 21 , is provided at the front end as seen in conveying direction F of the book blocks 3 , respectively at the intake for the conveying section 18 , with the aforementioned takeover station 17 in which the book blocks 3 are initially stopped until they are gripped on the conveying section 18 .
[0035] This downstream arranged conveying section 18 of the conveyor assigned to the processing section 20 is formed by two conveying belt sections 25 , 26 , arranged on the side at a uniform distance to the longitudinal center axis that extends through the longitudinal center plane for the upright standing books blocks 3 , of two adjacent and synchronously circulating conveying belts or conveying chains 27 , 28 , wherein the conveying belts 27 , 28 are driven around the approximately vertical axes of deflection rollers that are not visible herein.
[0036] The intake region 29 of the conveying section 18 , which is arranged upstream in conveying direction, projects counter to the conveying direction F over the transfer position for the conveying clamp 19 , respectively the clamping jaws 30 , 31 which form the conveying clamp, thus resulting in a super imposition of the conveying sections 16 , 18 . The intake region 29 forms a chain mouth 34 which is opened when a book block 3 is supplied with the aid of the conveying clamp 19 that is mounted on a sled or carriage. For this, the intake region 29 is expanded in a V shape to narrow down in a wedge-shaped taper in conveying direction F, thus ensuring a careful takeover of the book blocks 3 by the conveying section 18 .
[0037] The opening and closing of the chain mouth 34 is achieved by pivoting to the side around vertical axes 35 , 36 of the end sections 32 , 33 that form the intake region of the conveying belts 27 , 28 , wherein the empty belt sections of the conveyor belts 27 , 28 fit flush against side-mounted support rollers 37 , 38 . To change the conveying gap between the conveying belt sections or the working belt sections of the conveying belts 27 , 28 for adapting these to the thickness of the book blocks, the latter can be adjusted or readjusted uniformly with respect to the mutual spacing.
[0038] The takeover station 17 is followed in conveying direction F of the book blocks 3 , advanced by one clocking interval, by an adhesive application station 39 which is indicated by an adhesive roller 40 . The latter is driven to roll off the book block spine 21 for applying the adhesive, such that the book block 3 passes through the adhesive application station 39 without stopping and is stopped only after the next clocking interval in the backing station 41 , in which a backing material strip 43 is supplied from a roll 42 to the adhesive-coated book block spine 21 . Following two more clocking intervals in conveying direction F, a pressing station 44 is arranged on the processing section 20 in which the backing material 43 , placed onto the book block spine 21 , is pressed against the adhesive-coated book block spine. The book blocks 3 reach the casing-in machine 5 , respectively an available saddle plate 8 , over the course of two or four clocking intervals following the pressing station 44 . The conveying sections 16 , 18 , which function as a conveying device for the processing section 20 , are driven separately with the aid of individual drives 22 , 23 that are provided with angle of rotation controlled electric motors. The conveyor 6 of the casing-in machine 5 is also advantageously provided with a separate drive 45 which operates synchronized with the clocking rate of the at least one or both individual drives 22 , 23 for the conveying sections 16 , 18 via the joint control unit 24 .
[0039] FIG. 2 shows the book production line 1 during the processing of book blocks 3 , using a double clocking interval in conveying direction F between two processing stations 17 , 41 , 44 , 5 in which a book block spine 21 is processed while the book block 3 is stopped. In particular small and extremely small editions make it possible to move with multiple or double clocking intervals along the conveying section 18 (as shown in the embodiment) over the processing section 20 .
[0040] One difference lies in the manner in which the processing stations are arranged along the conveying section 18 . An idle stroke step 46 may be provided between the backing station 41 and the pressing station 44 to obtain a double clocking interval along the conveying section 18 , respectively a double stroke length for the clocking strokes.
[0041] With large editions, the resulting gap can be closed during normal operations by moving the pressing station 44 to be positioned downstream of the backing station 41 , for example by having a mobile station, thereby closing the gap once more. The adhesive-application station 39 does not present an obstacle for a double clocking interval since adhesive is applied to the spine 21 of a book block while it is passing through.
[0042] It is understood that the above description of the present invention is susceptible to various modifications, changes and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims.
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A production line including a casing-in machine and a processing section upstream of the casing-in machine. The processing section includes processing stations arranged at clocking intervals along the processing section to process a book block spine. The processing section includes a first processing station group and a second processing station group. The production line further includes a conveyor to successively supply the book blocks in clocked operation to the processing stations. The conveyor includes a first conveying section assigned to the first processing station group, the first conveying section including a first individual drive, and a second conveying section assigned to the second processing station group, the second conveying section including a second individual drive. The production line further includes a control unit operatively connected to the first individual drive and second individual drive to change the clocking interval length along the processing section.
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CROSS-REFERENCE TO RELATED APPLICATION
This application claims the priority benefit of Taiwan application serial no. 90203104, filed Mar. 3, 2001.
BACKGROUND OF THE INVENTION
1. Field of Invention
The present invention relates to a quadrant phase shift keying (QPSK) decoder. More particularly, the present invention relates to a device for computing tangent angles and an associated differential-encoding quadrant phase shift keying (DQPSK) decoder.
2. Description of Related Art
A conventional cable-connected transmissions system is low in mobility and short in communication distance. Therefore, many types of wireless communication techniques have been developed. Amongst wireless transmission systems, the most common one is the spread spectrum technique for transmitting voice or images. To eliminate as much interference as possible, a pseudo-noise sequence (PN) is often added to the system. Such spread spectrum techniques can be classified into two major types; namely, the frequency-hopping spread spectrum (FHSS) technique and the direct-sequence spread spectrum (DSSS) technique.
The advantages of employing the DSSS techniques in a wireless communication system include data privacy, flexibility comparison rules for the system (a soft-limited system), anti-jamming and fading rejection. However, a chip using the DSSS technique requires a large number of logic gates. Hence, a large section of the chip needs to be set aside for housing the logic gates and the chip tends to consume a large amount of energy. To resolve these problems, a digital receiver having a differential-encoding quadrant phase shift keying (DQPSK) device to serve as encoder and decoder and a matched filter using low-power pointer access memory (PAM) is used. Although such an additional component may attenuate the power consumption of the chip and area requirement in a chip slightly, the digital receiver also uses a decode/encoder having a coordinate system divided into eight quadrants. Therefore, operations demanded by the DSSS digital receiver are quite complicated. Such complications cancel out most of the advantages obtained by having fewer logic gates and lower power consumption.
SUMMARY OF THE INVENTION
Accordingly, one object of the present invention is to provide a device for computing tangent angles and associated differential-encoding quadrant phase shift keying (DQPSK) decoder such that the degree of complexity in operation is greatly reduced.
To achieve these and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, the invention provides a device for computing tangent angles. The tangent computing device includes a signal input terminal, a direct current input terminal, a plurality of subtractors, a plurality of comparators, a plurality of multiplexers, an eight-bit divider, a shift encoder, an XOR logic gate and an angle-computing device. The signal-input terminal includes a real part coefficient and an imaginary part coefficient for representing a complex number signal. The direct current input terminal receives a direct current signal. The positive input terminal of a first real part subtractor receives the direct current signal and the negative input terminal of the first real part subtractor receives the real coefficient. The subtraction result is output from the output terminal of the first real part subtractor. Similarly, the negative input terminal of a second real part subtractor receives the direct current signal and the positive input terminal of the second real part subtractor receives the real coefficient. The subtraction result is output from the output terminal of the second real part subtractor. The positive input terminal of a first imaginary part subtractor receives the direct current signal and the negative input terminal of the first imaginary part subtractor receives the imaginary coefficient. The subtraction result is output from the output terminal of the first imaginary part subtractor. Similarly, the negative input terminal of a second imaginary subtractor receives the direct current signal and the positive input terminal of the second imaginary part subtractor receives the imaginary coefficient. The subtraction result is output from the output terminal of the second imaginary part subtractor. A first comparator compares the direct current signal and the real part coefficient and outputs a real part label. A second comparator compares the direct current signal and the imaginary part coefficient and outputs an imaginary part label. A first multiplexer outputs an absolute real part value of the data from the first real part subtractor or the absolute value of the data from the second real part subtractor according to the real part label. Similarly, a second multiplexer outputs an absolute imaginary part value of the data from the first imaginary part subtractor or the absolute value of the data from the second imaginary part subtractor according to the imaginary part label. The XOR logic gate receives the real part label and the imaginary part label and outputs a logically XORed result. A third multiplexer receives the absolute real part value and the absolute imaginary part value. The third multiplexer outputs the absolute real part value or the absolute imaginary part value as a horizontal axis value according to the result produced by the XOR logic gate. A fourth multiplexer also receives the absolute imaginary part value and the absolute real part value. The fourth multiplexer outputs the absolute real part value or the absolute imaginary part value as a vertical axis value according to the result produced by the XOR logic gate. The eight-bit divider produces a tangent value by dividing the vertical axis value by the horizontal axis value. The shift encoder produces a set of shift-encoded signals according to the real part label and the imaginary part label. The angle-computing device produces quantized angular values according to the tangent value and the shift-encoded groups.
This invention also provides a DQPSK decoder to be used in conjunction with a tangent computation device. The DQPSK decoder receives the quantized angular value from the aforementioned angle-computing device and performs a decoding of the complicated signals from the DSSS receiver according to the quantized angular value.
In this invention, an eight-bit divider is used inside the tangent computation device. This reduces the degree of complexity in computation for a given degree of accuracy. Furthermore, the deployment of an encoder with four-quadrant encoding simplifies the encoding procedure considerably when compared with the conventional eight-quadrant encoding technique.
It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawing is included to provide a further understanding of the invention, and is incorporated in and constitutes a part of this specification. The drawing illustrates embodiments of the invention and, together with the description, serves to explain the principles of the invention. In the drawing,
FIG. 1 is a block diagram showing the components of a differential-encoding quadrant phase shift keying (DQPSK) decoding system according to one preferred embodiment of this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference will now be made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts.
FIG. 1 is a block diagram showing the components of a differential-encoding quadrant phase shift keying (DQPSK) decoding system according to one preferred embodiment of this invention. As shown in FIG. 1, the DQPSK decoding system includes a tangent computation device 100 and a DQPSK decoder 130 . The tangent computation device 100 further includes four subtractors 102 , 104 , 106 and 108 , two comparators 110 and 112 , four multiplexers 114 , 116 , 120 and 122 , an XOR logic gate 118 , an eight-bit divider 124 , a shift encoder 126 and an angle-computing device 128 .
The tangent computation device 100 has altogether three terminals including a direct current signal input terminal 105 , a terminal 101 for inputting the real part coefficient of a complex signal and a terminal 103 for inputting the imaginary part coefficient of the complex signal. In this embodiment, the real part coefficient I is fed into the tangent computation device 100 via the input terminal 101 while the imaginary part coefficient Q is fed into the tangent computation device 100 via the input terminal 103 . Inside the tangent computation device 100 , the real part signal I is re-directed to the positive terminal of the subtractor 102 and the negative terminal of the subtractor 104 , respectively. Similarly, the imaginary part signal Q is re-directed to the positive terminal of the subtractor 106 and the negative terminal of the subtractor 108 , respectively. In addition, direct current signal fed to the direct current terminal 105 is re-directed to the negative terminal of the subtractors 102 and 108 and the positive terminal of the subtractors 104 and 106 , respectively.
The multiplexer 114 outputs an absolute real part value abs(I) of the data either from the subtractor 102 or from the subtractor 104 according to the output of the comparator 110 . Similarly, the multiplexer 116 outputs an absolute imaginary part value abs(Q) of the data either from the subtractor 106 or from the subtractor 108 according to the output of the comparator 112 . The comparator 110 compares the direct current input from the direct current input terminal 105 and the real part coefficient I and outputs a real part label for indicating the polarity of the real part coefficient I. The comparator 112 compares the direct current input from the direct current input terminal 105 and the imaginary part coefficient Q and outputs an imaginary part label for indicating the polarity of the imaginary part coefficient I. Hence, based on the real part label and the imaginary part label, the multiplexers 114 and 116 are able to output absolute real part coefficient I and absolute imaginary coefficient Q from the pair of subtractors 102 and 104 and the pair of subtractors 106 and 108 , respectively.
The absolute real part coefficient I and the absolute imaginary part coefficient Q are sent to the eight-bit divider 124 via the multiplexers 120 and 122 as horizontal axis value and vertical axis value. To decide the respective multiplexer for outputting horizontal and vertical axis value, an XOR logic operation of the real part label (sign(I)) and the imaginary part label (sign(Q)) is conducted through the XOR logic gate 118 . According to the horizontal axis value and vertical axis value, the 8-bit divider 124 produces a tangent value by dividing the vertical axis value by the horizontal axis value. The tangent value is transmitted to the angle-computing device 128 . In this embodiment, the tangent value is quantized into an angular value using a lookup table having 8-bit accuracy. The quantized angular value is stored as a phase bit series with five bits representing phase value and two bits representing phase shift. For example, for a phase bit series=XX10110, XX indicates the phase shift value while 10110 is the phase value after angular quantization. In other words, when θ=tan −1 (Q/I)+phase shift value, tan −1 (Q/I) is the angular quantization while θ is the phase value. Furthermore, θ=tan −1 (Q/I)=tan −1 (Y/X) so that the values of (X, Y) are (I, Q) when IQ>0 and are (Q, I) when IQ<0. In addition, the method of calculating the phase shift value is as follows:
if label ‘0’ represents positive and label ‘1’ represents negative, and
if the real part label and the imaginary part label are both ‘0’, the phase shift value={sign(I), sign(Q)}90°={0,0}90°=00;
if the real part label is ‘1’ and the imaginary part label is ‘0’, the phase shift value={sign(I), sign(Q)}90°={1,0}90°=01;
if the real part label is ‘0’ and the imaginary part label is ‘1’, the phase shift value={sign(I), sign(Q)}90°={0,1}90°=10; and
if the real part label and the imaginary part label are both ‘1’, the phase shift value={sign(I), sign(Q)}90°={1,1}90°=11.
Hence, this invention can use four quadrants to obtain a corresponding angular quantization through the tangent value, thereby simplifying computational operations.
After obtaining a quantized value from the angle-computing device 128 , the quantized angular value is sent to the DQPSK decoder 130 . According to the quantization value, complex signal received by the DSSS receiver can be decoded inside the DQPSK decoder 130 . Ultimately, the required data is obtained.
In conclusion, one major aspect of this invention is the utilization of an 8-bit divider for reducing computational complexity and operation time. Furthermore, angular quantization is achieved through four quadrants instead of the conventional eight quadrants. Therefore, degree of complexity of logical computation within the device is further simplified.
It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the present invention cover modifications and variations of this invention provided they fall within the scope of the following claims and their equivalents.
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A tangent angle computation device and associated DQPSK decoder. The computation device uses an eight-bit divider and a four-quadrant technique for finding a quantized angular value from an incoming signal. The quantized angular value is subsequently used to decode the incoming signal.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims benefit under 35 U.S.C. §119 to European Patent Application No. 12194531.5 entitled “Electrical Tripping Sub for Wired Drill Pipes” filed on Nov. 28, 2012, the disclosure of which is hereby incorporated by reference in its entirety.
FIELD
[0002] The disclosed technology relates generally to wired drill pipes. More specifically, the disclosure is directed to systems, methods, and devices for connecting at least one electrical data and/or supply line to electrical sockets of a wired drill pipe when the drill pipe is not in an active drilling operation.
BACKGROUND
[0003] Currently, simple steel pipes are screwed together in many drilling facilities. In this manner, a drill string is formed to be several kilometres long and a drill bit is attached at an end of the drill string. In an interior of the pipes, there is a rinsing fluid (e.g., mud) for fulfilling a variety of functions during a drilling process. One of those functions may be an transmission of data via pressure pulses. However, since this data transmission is slow (e.g., a typical transmission rate is around 10 Baud), increasing efforts have been undertaken in drilling industries for obtaining bore information during a drilling operation at higher data transmission rates. For example, a downhole data transmission system of U.S. Pat. No. 6,670,880 is shown to transmit data through a plurality of drilling components of a drill string. Each of the drilling components is connected at its two ends to ends of subsequent drilling components. A coaxial cable within each drilling component extends from one end to the other end of the drilling component and is connected to the coaxial cables of adjacent drilling components. During a drilling operation, a swivel enables communications between the downhole data transmission system and instruments positioned at surface. Other transmission mechanisms are also used. For example, sonar or electric currents across the soil, etc. However, solutions based on a wiring of the drill string (e.g., electrical cables or light guides) have turned out to be most efficient.
[0004] Logging of data from the bore during a drilling process has become an essential element in modern crude oil, natural gas or geothermal drillings. This type of data acquisition is also referred to as Measurement While Drilling (MWD) or Logging While Drilling (LWD). Data acquisition is also important for a construction of the bore and a subsequent production of crude oil, gas and/or warm water. A drilling can be operated safely, efficiently and economically only by accurately determining respective relevant measurements. More data from below ground are available, more efficiently and safely can a drilling operation be organized. Therefore, the drilling industry increasingly demands a transmission of data at high data rates (e.g., 200 kBaud) from a depth of several kilometres. This request results in increasing demands on the power of underground measuring units and therefore, an increase in the electric power consumption of the underground measuring units. In order to account for this increasing electric power consumption, the underground measuring units should be supplied with electric energy (e.g., with 200 W) also from the surface.
[0005] In PCT Publication No. WO 2010/141969 A2, a device for connecting electrical cables on essential tubular connection elements, which can be screwed to each other, is disclosed, in which a first electrical contact element is firmly arranged on a first connection element and a second electrical contact element is arranged on a second connection element so as to be displaceable in the direction of rotation of the connection element. By means of this device, a problem of the electrical connection between the pipes of the drill string may be solved. The electrical connection has turned out to be reliable, simple and robust for the mechanical connection of pipes (e.g., a rotary movement) and enables a transmission of electric power and/or data under the severe conditions prevailing in the bore, such as a high pollution, the presence of all kinds of liquids, high temperatures and mechanical shocks. Using a drill string constructed in this manner, it is possible to feed electric power into underground measuring units during a drilling process, for example, with the aid of slip ring assemblies arranged at the top-drive and acting as swivels and to read out and evaluate data generated by those underground measuring units.
[0006] However, in particular for increasing the safety of the bore, it is also necessary to provide energy supply for underground measuring units and to read out data when no drilling operation is performed and the drill string is dismantled (trip-out) or installed by pipes being assembled (trip-in). In addition, it is of utmost importance to know whether changes relevant to safety occur in the bore, such as, e.g., pressure changes, friction, formation of gas bubbles etc.
[0007] In European Patent No. EP 2,273,058 A2, instruments for providing communications with a wired drill pipe during a tripping operation are disclosed. The instruments can be connected to the drill string and comprise so-called sub-coupler heads. A first type of sub-coupler head has a threadless surface which, during the installation in a wired drill pipe, exerts a retaining force against a thread section of the drill pipe via a friction or press fit. The friction or press fit is achieved by spreading the sub-coupler head. A communication element is embedded in the sub-coupler head to couple communicatively to a pipe communication element, if the sub-coupler head is positioned within the receiver end of the wired drill pipe. Inductive couplers and direct connection couplers, among other things, are mentioned as communication elements. A wiring connection, mud-pulse telemetry, electronic telemetry and/or acoustic telemetry are cited as examples of communicative coupling. The material of the sub-coupler head is elastic or deformable, respectively, and soft with regard to the material of the drill pipe so that the thread of the drill pipe is not damaged. In an alternative exemplary embodiment of the sub-coupler head, its surface exhibits a partial thread. The communication device serves only for the transmission of signals, but not for supplying underground measuring units with electric energy.
[0008] In U.S. Pat. No. 7,198,118, a communication adapter for a detachable connection to a drilling component outside of the active drilling operation is disclosed. The communication adapter comprises a data transmission coupler for data communication with a transmission system integrated in the drilling component, a mechanical coupler for removably attaching the adapter to the drilling component and an integral data interface comprising a screen, a gauge, a loudspeaker or a light. The mechanical coupler comprises a thread or solenoids or locking mechanisms such as, e.g., elastic clips or clamps. In one exemplary embodiment, the mechanical coupler comprises cams which can be swiveled about a swivel axis into an engagement with an internal thread of the drilling component. The communication adapter serves only for the transmission of signals, but not for supplying underground measuring units with electric energy.
[0009] The intention of feeding energy, data and/or control signals into and, respectively, out of the drill string during the trip-in and, respectively, trip-out operation of the bore encounters primarily the following difficulties:
The drill string is not regularly screwed to the slip ring assembly, which, therefore, cannot be used for electrical power supply and communications. For safety reasons, electric energy supply units, data processing devices and controls are located outside of the drilling rig in a switch cabinet and they must be connected to the drill string via energy supply, status and control lines. The energy supply, status and control lines must be linked to the drill string via an electromechanical unit which functions highly reliably under the severe operating conditions and in accordance with safety regulations such as those for explosion protection zone 1 and yet is easy to handle for the operating staff, whereby semiautomatic or manual connecting and separating should be possible.
[0013] The disclosed technology is based on the object of providing a solution to the above-discussed problems associated with feeding electric energy, data and/or control signals into and, respectively, out of the drill string during the trip-in and, respectively, trip-out operation of the bore.
SUMMARY
[0014] Various implementations of systems, methods and devices within the scope of the appended claims each have several aspects, no single one of which is solely responsible for the desirable attributes described herein. Without limiting the scope of the appended claims, some prominent features are described herein.
[0015] The disclosed technology provides a device for connecting at least one electrical data and/or supply line to drill pipe electrical sockets of a wired drill pipe, when the wired drill pipe is not in an active drilling operation.
[0016] The disclosed technology also provides a method of connecting at least one electrical data and/or supply line to drill pipe electrical sockets of a wired drill pipe, when the wired drill pipe is not in an active drilling operation.
[0017] These and other objects of the disclosed technology will be described in or be apparent from the following description of the preferred embodiments.
[0018] According to an aspect of the disclosed technology, there is provided a device comprising electrical sockets galvanically connecting to the at least one electrical data and/or supply line and contacting with the drill pipe electrical sockets. The device further comprises a collet blocking plug configured to be axially insertable into and removable from a receiver end of the drill pipe and at least one collet configured to be axially displaceable from the collet blocking plug between a locking position and a release position. The collet is configured to be interlocked with the drill pipe in the locking position. The collet is released from the drill pipe in the release position.
[0019] According to an aspect of the disclosed technology, there is provided a method comprising connecting electrical sockets galvanically to the at least one electrical data and/or supply line and contacting with the drill pipe electrical sockets. The method further comprises interlocking at least one collet with the drill pipe in a locking position and releasing the collect from the drill pipe in a release position. The collet is configured to be axially displaceable from a collet blocking plug between the locking position and the release position. The collet blocking plug is configured to be axially insertable into and removable from a receiver end of the drill pipe.
[0020] Said object is achieved by a device for connecting at least one electrical data and/or supply line to electrical sockets of a wired drill pipe having the features of claim 1 . Advantageous embodiments are set forth in the subclaims, in the specification and in the drawings.
[0021] By means of the tripping sub, according to an embodiment, at least one electrical data and/or supply line can be connected to electrical sockets of a wired drill pipe, if the drill pipe is not in the active drilling operation. The tripping sub according to an embodiment comprises: electrical sockets which are galvanically connected to the at least one electrical data and/or supply line and can be brought into contact with the electrical sockets of the drill pipe; a collet blocking plug axially insertable into and removable from a receiver end of the drill pipe; and at least one collet. The collet blocking plug and the collet are axially displaceable relatively to each other between a collet position and a release position, wherein, in the collet position, the collet is configured to interlock with the drill pipe and wherein, in the release position, the engagement of the collet with the drill pipe is undone.
[0022] The tripping sub according to an embodiment is particularly suitable for being connected to the connection elements of wired drill pipes as described in the above mentioned patent application WO 2010/141969 A2, whereas an adjustment to standard threads of standard drill pipes is not an object of the embodiments.
[0023] A locking between the tripping sub according to an embodiment and the drill pipe which is fabricable quickly and safely can be achieved if the collet is radially movable, preferably radially movable in an elastic way.
[0024] If, in the tripping sub according to an embodiment, the collet is radially retractable in the release position, the tripping sub can be guided out of the drill pipe with particular ease. In a preferred construction of an embodiment, the collet blocking plug has at least one indentation, preferably at least one peripheral groove, into which the collet is radially retractable in the release position. Particularly safe handling of the tripping sub according to an embodiment can be achieved if the collet blocking plug has two indentations, preferably peripheral grooves, which are axially offset and define two different release positions. A first release position is thereby taken by a relative axial displacement of the collet blocking plug toward the collet in a first direction, and a second release position is taken by a relative axial displacement of the collet blocking plug toward the collet in the opposite direction. A high mechanical stability of the connection between the tripping sub and the wired drill pipe and protection against loosening of the connection in the occurrence of tensile forces is achieved if, in the collet position, a section of the collet blocking plug forms an abutment against radial retraction of the collet.
[0025] Good manageability of the tripping sub according to an embodiment is achieved if the collet has projections which are configured to join in indentations of the drill pipe in the collet position or if the collet has indentations which are configured to join in projections of the drill pipe in the collet position.
[0026] In a space-saving and mechanically highly reliable embodiment of the tripping sub according to an embodiment, the collet is designed as a clamping sleeve surrounding the collet blocking plug.
[0027] In order to prevent an unintended loosening of the connection to the drill pipe, the tripping sub can be prestressed into the collet position, preferably by means of centering springs.
[0028] For a particularly high reliability and a fast establishing of the electrical connection, in a preferred embodiment of the tripping sub according to an embodiment, a rotary external body is provided in which the electrical sockets are configured such that they can be brought into contact with the electrical sockets of the drill pipe by a rotary movement of the external body. Providing rotation handles facilitates the turning of the tripping sub for the operating staff. Providing axial running handles generally simplifies the manual guidance of the tripping sub. In a preferred embodiment, the external body and the collet are axially connected with regard to each other in an essentially rigid, but rotatable way. The connection can thereby be implemented by means of a rotation blocking plug which is axially connected to the collet in a rigid way and, on its outer surface, has an external thread onto which an internal thread of the external body is screwed in a rotatable way. The collet and/or the rotation blocking plug can be locked against twisting with regard to the collet blocking plug by a rotation blocking element. Alternatively, the rotation blocking plug can comprise rotation blocking elements for join in the drill pipe.
[0029] For an automatic or at least semiautomatic connection of the tripping sub to a drill pipe, it is envisaged that the external body is rotatable by means of a motor and optionally a gear, wherein the tripping sub preferably being equipped with actuators for an automatic supply to and take away from the drill pipe.
[0030] Furthermore, for safety reasons, an electrical detection switch is recommended which detects whether the electrical sockets of the tripping sub are in contact with the electrical sockets of the drill pipe.
[0031] In order to avoid that the electrical cables twist too much and, as a result, break or their insulation is damaged, it is also envisaged in an embodiment that at least one electrical cable is guided out of the tripping sub in a loom of cables by means of a rotation compensator device.
[0032] For conducting measurements, for example, on stored drill pipes, it is purposeful to design the tripping sub according to an embodiment as a handheld device, wherein at least one device for feeding and discharging data, status and/or test signals and for evaluating discharged signals is connected to the at least one electrical data and/or supply line, the device preferably having a user interface.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] FIG. 1 shows a detail of a drilling facility comprising a tripping sub, in accordance with an exemplary embodiment.
[0034] FIG. 2 shows the connection of the tripping sub 2 to a swivel body and a wired drill pipe, in accordance with an exemplary embodiment.
[0035] FIGS. 3 and 4 show an embodiment of the tripping sub in a perspective illustration, in each case partially sectioned.
[0036] FIG. 5 shows an arrangement of a collet and a rotation blocking plug in the tripping sub.
[0037] FIGS. 6-11 show the process of connecting the tripping sub to the drill pipe, in accordance with an exemplary embodiment.
[0038] FIGS. 12 and 13 show a process of loosening the connection of the tripping sub to the drill pipe, in accordance with an exemplary embodiment.
[0039] FIG. 14 shows an exemplary embodiment of the tripping sub having a motor drive.
[0040] FIG. 15 shows a furnishing of the tripping sub with devices for automatic placement.
[0041] The various features illustrated in the drawings may not be drawn to scale. Accordingly, the dimensions of the various features may be arbitrarily expanded or reduced for clarity. In addition, some of the drawings may not depict all of the components of a given system, method or device. Finally, like reference numerals may be used to denote like features throughout the specification and figures.
DETAILED DESCRIPTION
[0042] Advantages and features of the disclosed technology and methods of accomplishing the same may be understood more readily by reference to the following detailed description of preferred embodiments and the accompanying drawings. The disclosed technology may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are disclosed so that this disclosure will be thorough and complete and will fully convey the concept of the invention to those skilled in the art, and the disclosed technology will only be defined by the appended claims. Like reference numerals refer to like elements throughout the specification.
[0043] The drawings and description are to be regarded as illustrative in nature and not restrictive. Like reference numerals designate like elements throughout the specification.
[0044] Further, since sizes and thicknesses of constituent members shown in the accompanying drawings are arbitrarily given for better understanding and ease of description, the disclosed technology is not limited to the illustrated sizes and thicknesses.
[0045] FIG. 1 shows a detail of a drilling facility for crude oil, natural gas or geothermal drillings, wherein measuring units arranged at the wired drill string are supplied, via the wiring, with electric energy, control signals and/or data that are sent by the measuring units, via the wired drill string, to control and evaluation devices located above ground. The data transmission also takes place when no drilling operation is performed. But, as is illustrated here, the drill string is demounted (trip-out) or installed by pipes assembled (e.g., trip-in). In FIG. 1 , a grabber assembly 1 is shown to hold a topmost wired drill pipe 6 of a wired drill string. The upper end, the so-called “box-end,” of the wired drill pipe 6 is referred as a device 2 for connecting electrical data and/or supply lines arranged in a flexible part of a data cable housing sleeve 18 . The data cable housing is connected to electrical sockets of the, wired drill pipe 6 . The wired drill pipe 6 is preferably a drill pipe comprising a connection element as described in PCT Patent Publication No. WO 2010 / 141969 A2. The flexible part of the data cable housing sleeve 18 leads to a data cable housing sleeve 5 . The data cable housing sleeve 5 is fixed to a swivel body 3 . The electrical cables continue from the data cable housing sleeve 5 to a wired mounting sub 4 and proceed to control and evaluate energy supply devices located remotely from the drilling facility. Because of this arrangement, it is possible to control electric circuits located in the drill string and to supply them with energy. During a drilling operation of the drilling facility, the tripping sub 2 is parked in a box 11 so that it neither disturbs the drilling operation, nor can it get damaged. As such, the tripping sub 2 will immediately be available again in subsequent tripping operations. During the drilling operation, the wired mounting sub 4 is directly connected to the wired drill pipe 6 .
[0046] FIG. 2 shows a connection of the tripping sub 2 to a swivel body 3 and the wired drill pipe 6 in an enlarged illustration, in accordance with an exemplary embodiment. With screws 21 , the swivel body 3 is mounted to a split bushing 13 . The split bushing 13 is retained on the wired mounting sub 4 with the aid of binding clips 12 . For connecting the swivel body 3 to the wired drill string during a drilling operation, an electrical cable 16 is guided through the split bushing 6 . Above the electrical swivel body 3 , a bearing mount unit 9 is mounted rotatably to the split bushing 13 . A synchronizing system 14 connects the bearing mount unit 9 and the swivel body 3 in a torque-proof manner to each other so that they may rotate relative to the wired mounting sub 4 only jointly. A bar-shaped holder 10 projects radially outwards from the bearing mount unit 9 . The box 11 for the tripping sub 2 and the data cable housing sleeve 5 are affixed to the holder 10 . An input electrical cable 23 and an output electrical cable 17 run out of the swivel body 3 and run into the data cable housing sleeve 5 via a slip ring assembly located in an interior of the swivel body 3 , which is not illustrated here. The input electrical cable 23 and the output electrical cable 17 also run from there into the flexible part of the data cable housing sleeve 18 . The data cable housing sleeve 18 is attached to the data cable housing sleeve 5 via a socket plug connector 15 . During remodeling operations (e.g., tripping operations), the input electrical cable 23 and the output electrical cable 17 are galvanically connected to the wired drill pipe 6 via the tripping sub 2 . During the remodeling operations, the end of the wired mounting sub 4 is protected by a protection cap 26 . In order that the flexible part of the data cable housing sleeve 18 does not twist when the tripping sub 2 is being used, the flexible part of the data cable housing sleeve 18 ends in a device for compensating rotation 8 of the tripping sub 2 , using a socket plug connector 41 .
[0047] FIG. 3 and FIG. 4 show an exemplary embodiment of the tripping sub 2 in a perspective illustration, in each case partially sectioned. The tripping sub 2 comprises an essentially frustoconical external body 31 from which an axial running handle 39 for the manual axial guidance of the tripping sub 2 and three rotation handles 38 for manually rotating the external body 31 extend for easier handling during an insertion into the drill pipe. The external body 31 is configured such that it creates protection against the infiltration of drilling mud. The external body 31 is also constructed in an explosion-proof way. Furthermore, the device for compensating rotation 8 extends from the external body 31 in a rotatable way. The rotation 8 has already been illustrated above, on which the socket plug connector 41 may be seen. At a front face which faces the drill pipe of the external body 31 , an electrical detection switch 25 is arranged (see in particular detail D in FIG. 4 ). The electrical detection switch 25 detects whether the electrical sockets 35 of the tripping sub 2 have been brought into contact with the electrical sockets of the drill pipe. The electrical sockets 35 may be designed as standard electrical sockets which end to the front face of the external body 31 , and the electrical sockets of the drill pipe extend axially in the form of contact pins. Electrical cables 42 run from the electrical sockets 35 through the interior of the tripping sub 2 to the socket plug connector 41 . A rotation blocking plug 34 , a collet 33 in the form of a clamping sleeve and a collet blocking plug 32 are arranged within the external body 31 in coaxial orientation thereto from the outside to the inside.
[0048] The collet 33 serves for fixating the tripping sub 2 in the drill pipe in an axial direction. For this purpose, the collet blocking plug 32 and the collet 33 are axially displaceable relative to each other between a locking position and a release position, with the collet 33 being divided in its front region into a plurality of tongues 33 b. The tongues 33 b are radially movable in an elastic way and, at their free ends, exhibit projections 33 a for interlocking with the drill pipe. In a collet position, the tongues 33 b are extended radially. In a release position, they are retracted radially, as it is explained below in further detail. The collet blocking plug 32 has two indentations in the form of peripheral grooves 32 a and 32 c, which are separated from each other by a web-shaped section 32 b and receive the projections 33 a of the collet 33 in two different release positions.
[0049] The collet 33 is axially mounted in a rigid way with regard to the rotation blocking plug 34 so that axial movements of the collet 33 and axial movements of the rotation blocking plug 34 take place jointly, whereby the rotation blocking plug 34 is unable to obstruct the radial movement of the tongues 33 b. A buttress thread 37 comprises an external thread 34 c on the peripheral surface of the rotation blocking plug 34 and an internal thread 31 a on the interior surface of the external body 31 . With the buttress thread 37 , the rotation blocking plug 34 and the external body 31 are interconnected in such a way that the rotation blocking plug 34 , the collet 33 and the external body 31 are axially moved jointly in relation to the collect blocking plug 32 if the external body 31 is moved axially. However, in a rotary movement of the external body 31 in relation to the collet 33 , the external body 31 is movable axially in relation to the collet 33 . With two central springs 36 , the rotation blocking plug 34 , the collet 33 and the external body 31 are prestressed into such an axial position relative to the collet blocking plug 32 that the tripping sub 2 is located in the locking position in which the projections 33 a of the collet 33 rest on the web section 32 b of the collet blocking plug 32 . The two central springs 36 exert equal spring forces from opposite directions, whereby an equilibrium of forces is produced and results in the relative axial position.
[0050] The rotation blocking plug 34 serves for radially fixating the tripping sub 2 in the drill pipe. For this purpose, the rotation blocking plug 34 exhibits, at its front face, a sequence of projections 34 a and indentations 34 b which interlock with indentations and projections of a protective sleeve in the drill pipe, which are formed in a mirror-inverted fashion. In order to prevent that the collet 33 and the rotation blocking plug 34 twist with regard to the collet blocking plug 32 , a rotation blocking pin 43 is provided. As a result of this construction, the collet 33 and the rotation blocking plug 34 are secured radially and axially in relation to the drill pipe in the state of connection between the tripping sub 2 and the drill pipe.
[0051] FIG. 5 shows the arrangement of the collet 33 and the rotation blocking plug 34 . In this figure, the plurality of tongues 33 b with the projections 33 a and the front-end projections 34 a and indentations 34 b may be seen particularly well. For the sake of clarity, the external thread 34 c on an outer surface of the rotation blocking plug 34 is not depicted graphically, but is annotated by reference numeral 34 c.
[0052] In the following, a process of connecting the tripping sub 2 to the drill pipe 6 is explained on the basis of FIGS. 6 to 11 , and the subsequent loosening of said connection is explained on the basis of FIGS. 12 and 13 . FIG. 6 shows an initial insertion of the external body 31 into a conical receiving space 71 of a box end 70 of the wired drill pipe 6 , with detail A showing an enlarged illustration of a cutout of FIG. 11 . The drill pipe 6 comprises electrical sockets 73 (pins) for a galvanic connection to the electrical sockets 35 (e.g., bushings) of the tripping sub 2 . At the box end 70 , a sleeve-shaped connection element 72 is arranged. The sleeve-shaped connection element 72 comprises a ring-shaped lug 72 a facing the tripping sub 2 , a ring-shaped indentation 72 b formed behind the lug 72 a as well as a conical central surface 72 c. When the tripping sub 2 is inserted axially with the aid of the axial running handle 39 , the tapered front end of the collet blocking plug 2 is axially centred through the central surface 72 . Because of the prestressing by means of the central springs 36 as explained above (see, e.g., FIG. 4 ), the tripping sub 2 is located in a locking position in which the projections 33 a of the collet 33 rest on the web-shaped section 32 b of the collet blocking plug 32 . As a result, the projections 33 a abut against the lug 72 a of the connection element 72 of the drill pipe 6 during the insertion of the tripping sub 2 , whereby a further axial movement of the collet 33 is initially prevented. However, as shown in FIG. 7 , the collet blocking plug 32 may move well further into the drill pipe 6 in the axial direction, whereby the web-shaped section 32 b of the collet blocking plug 32 moves away from the projections 33 a and the second peripheral groove 32 c of the collet blocking plug 32 comes into alignment with the projections 33 a. As shown in FIG. 8 , the peripheral groove 32 c provides a free space necessary for an elastic radial inward movement to the tongue 33 b with its projections 33 a in that the lug 72 a presses the projections 33 a inwards. In this manner, the collet 33 may axially move further forward, while the projections 33 a glide through underneath the lug 72 a and reach the indentation 72 b of the connection element 72 . As shown in FIG. 9 , the indentation 72 b provides free space for the projections 33 a, whereby the tongues 33 b may move back into their radial starting position. When the axial insertion movement of the connection element 2 stops, the collet blocking plug 32 moves slightly back into its equilibrium position as a result of the prestressing by the central springs 36 , in which position the web-shaped section 32 b again constitutes an abutment to the projections 33 a so that they are prevented from a radial inward movement, whereby the locking position is taken, see FIG. 10 .
[0053] As shown in FIG. 11 , using the rotation handles 38 , the external body 31 of the tripping sub 2 is rotated so that the electrical sockets 35 (e.g., bushing) of the tripping sub 2 come into an axial alignment with the electrical sockets 73 (e.g., electrical contact pins) of the drill pipe 6 . The fixation of the external body 31 in its axial position (i.e., against the spring pressure of pressure plates in the interior of the drill pipe 6 ) is performed with the buttress thread 37 . This position with galvanically connected electrical sockets 35 and 73 constitutes a working position connecting the connection element 2 to the drill pipe 6 during remodeling operations.
[0054] In order to loosen a connection between the drill pipe 6 and the tripping sub 2 , the above described operations are conducted in the reverse order. That means that at first, by rotating the external body 31 in the opposite direction, the axial fixation thereof has to be loosened. An interruption of the galvanic contact of the electrical sockets 35 and 73 occurs by loosening the axial fixation of the external body. By pulling the axial running handle 39 , the collet blocking plug 32 axially moves outwards in relation to the collet 33 , since the collet 33 is prevented from an axial movement because its projections 33 a abut against the lug 72 a of the connection element 72 of the drill pipe. As shown in FIG. 12 , with a relative displacement between the collet blocking plug 32 and the collet 33 , the first peripheral groove 32 a comes into alignment with the projections 33 a. As such, the projections 33 a may be pressed radially inwards into the peripheral groove 32 a by the lug 72 , as shown in FIG. 13 , whereby the locking of the collet 33 loosens and the latter may also be moved axially outwards in an unhindered fashion.
[0055] The exemplary embodiment of the tripping sub 2 according to an embodiment, as it has been described so far, is provided for the manual operation of the drilling facility by the operating staff However, it is also possible to furnish the tripping sub 2 for a semiautomatic or fully automatic operation.
[0056] FIG. 14 shows an exemplary embodiment of the tripping sub 2 which is provided with a motor drive for rotating the external body 31 . A motor 53 rotates the external body 31 in relation to the collet blocking plug 32 via a gear comprising a pinion gear 51 on the driving shaft of the motor 53 and a gear ring 52 on the outer surface of the external body 31 . With external drives 50 , the axial movement of the external body 31 in relation to the collet blocking plug 32 is controlled. In some exemplary implementation, the external drives 50 are implemented as hydraulic or pneumatic cylinder-piston systems or as threaded spindles. The drives 50 are located on a rotation compensator device 40 to which also the socket plug connector 41 is attached. Also in this exemplary embodiment, an electrical detector switch 54 is provided which detects whether the external body 31 has been rotated into a correct angular orientation in relation to the drill pipe, in which a galvanic connection between the electrical sockets of the tripping sub and of the drill pipe occurs. The final fixation of the external body 31 by the external drives 50 occurs in this correct angular orientation.
[0057] FIG. 15 shows a furnishing of the tripping sub 2 with devices for automatically placing the tripping sub 2 on the drill pipe 6 , while it is being held by a grabber assembly 1 . For this purpose, the tripping sub 2 is accommodated in a housing 63 mounted on the holder 10 via actuator arms 61 and 62 and the holder 10 is fixed to the swivel body 3 via the bearing mount unit 9 . The wired mounting sub 4 extends from the swivel body 3 . The actuator arms 61 and 62 are guided to and from the drill pipe 6 by actuators 60 in a three-dimensional movement. The housing 63 has a conical open end which facilitates the placement on the drill pipe 6 in a centred orientation. Distance metres may also be used for a more precise placement.
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A device for connecting at least one electrical data and/or supply line to electrical sockets of a wired drill pipe is disclosed. One inventive aspect of the device comprises: a collet blocking plug axially insertable into and removable from a receiver end of the drill pipe and at least one collet. The collet is configured to be interlocked with the drill pipe in a locking position and be released from the drill pipe in a release position. The collet is axially displaceable from the collet blocking plug between the locking position and the release position. The collet blocking plug is axially insertable into and removable from a receiver end of the drill pipe.
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BACKGROUND OF THE INVENTION
The present invention relates to apparatus for the pretreatment of sea water or briny water to prevent scaling in desalination apparatus.
It is known that apparatus for producing fresh water from sea water or briny water which operates on the evaporation-distillation principle has a limited capacity owing to upper temperature and operating limits imposed by scaling.
The principal ions directly or indirectly responsible for scaling are, in the case of sea water, calcium and magnesium cations and bicarbonate and sulfate anions; the nature of the deposit which forms is dependent on the operating temperature.
To prevent calcium carbonate deposits, it is possible to use adsorbents or growth inhibitors such as polyphophates. It is also possible to decompose the carbonate by the injection of an acid, for example, sulfuric acid, and degassing. In the case of calcium sulfate, a conventional method of preventing crystallization consists in limiting the temperatures and concentrations of the brine so that the thermodynamic conditions of precipitation never occur in the course of the evaporation-distillation cycles. However, this method, which is advantageous because it does not necessitate any initial chemical processing, is obviously subject to a certain temperature limitation, i.e. on the order of 120°C, and, therefore, is not compatible with the objective of obtaining maximum yields from the evaporation-distillation process. It is also possible to remove the greater part of the calcium ions by a softening process, e.g. by ion exchange, although the cost of such a process is prohibitive.
It is known that the scaling problem can be economically reduced to permit operation of the evaporators at high temperatures in excess of 120°C by the introduction of crystalline nuclei into the heated sea water. The addition of the nuclei to a metastable or over-saturated solution results in the deposition or crystallization of the salts in solution on the nuclei, and thereby avoids nucleation of these salts on the heated walls of the evaporator.
In this type of treatment, crystalline nuclei (for example, anhydrite) are added to the untreated sea water before it enters the evaporation unit wherein it is progressively heated by its passage through the condensers of the unit. This preheating of the crude sea water, a conventional step in any distillation process, is continued to a higher temperature than that of the first stage of the evaporation unit and to a higher temperature than that corresponding to the limit of solubility in water of the alkaline-earth carbonates and calcium sulfate scaling agents.
In the course of this heating operation, crystallization of these compounds occurs and the carbonates and sulfate crystals grow on the suspended anhydrite nuclei.
Sea water at a high temperature, e.g. 170°C, containing a mixture of crystals in suspension is thus obtained. Before introduction into the first stage of the evaporator, it is necessary to clarify this water by removing the suspended crystals. If the suspended crystals are not removed they will redissolve during the cooling of the water in the successive stages of the evaporation unit and form scale on the various ducts in the evaporation unit. This scaling would result in lowering the efficiency of the desalination process. Thus, it is absolutely essential to remove the crystals of alkaline-earth carbonate salts and calcium sulfate before cooling and/or evaporation.
The temperature and pressure of the water requiring clarification (temperature in excess of 120°C) make it difficult and costly to employ a standard decanter/centrifuge or filter; such apparatus must be specifically designed to permit reliable operation under these conditions.
SUMMARY OF THE INVENTION
The present invention relates to a device of simple design for decanting crude sea water solutions containing the above-mentioned scaling salts and which lends itself to use in combination with conventional apparatus used in desalination processes, e.g. multiple effect evaporation units (for example, a descending evaporation unit) and evaporation-distillation units operating on the expansion and recycling principle. More particularly, the present invention relates to an evaporator/decanter and to its use in combination with the various types of process equipment used in desalination processes.
The apparatus of the present invention is provided with inner and outer vertically mounted vessels or containers having generally cylindrical upper portions closed by conically shaped bottom portions. The inner vessel is mounted centrally within the outer vessel and houses an inverted funnel member. The funnel member has a lower conical portion and an upper leg portion which extends through the top of said inner vessel. The apparatus is additionally provided with means for introducing a liquid suspension of solids, vapor discharge means, solids discharge means and liquid discharge means for removing the clarified water. The liquid discharge means includes a gutter or trough member situated around the inner circumference of said inner vessel near the top thereof and a duct for removal of liquid from the interior of the gutter to a point remote from the apparatus. A second solids discharge means is provided for the removal of solids which collect in the bottom conical portion of the outer vessel.
In the process of the present invention, employing the apparatus described above, seed crystals (e.g. calcium carbonate crystals in the form of anhydrite) are added to the water to form a suspension therein and then heated to a temperature above the solubility limit of the scaling agents to cause the scaling agents to crystallize or deposit on the seed crystals. This liquid suspension of crystals ("cloudy" water) is then introduced into the outer vessel of the above-described apparatus for the purpose of separating the crystals from the water. The decanted and clarified water is removed from the gutter located in the upper portion of the inner vessel and may be used as a feed water for supply to the first stage or effect of a standard desalination unit. A portion of the crystals removed from the bottom of the evaporator/decanter of the present invention may be used as seed crystals for addition to the water prior to the heating and separation as described above.
The present invention also contemplates a desalination process in which the apparatus of the present invention is used in combination with a multiple effect evaporation unit. In this embodiment the sea water feed, after addition of the seed crystal, is heated by passage through the series of condensers associated with the various effects of the evaporation unit and then injected into the outer vessel of the evaporator/decanter. In this embodiment, the evaporator/decanter operates as an evaporator and as the first stage or effect of the evaporation/distillation system. The evaporator/decanter is maintained at a temperature higher than the temperatures within the various effects of the desalination unit proper. The preheated sea water which enters the decanter of the present invention flashes upon entry producing water vapor or steam which may be reused as a heat source by injection into an interposed heat exchanger or at a suitable point with the multiple effect evaporator (e.g. the first effect).
In heating the feed to the evaporator/decanter to effect crystallization of the scaling agents, it is preferable to interpose a heat exchanger between the evaporator/decanter and the desalination unit proper unit and to employ operating temperatures such that the clarified sea water leaving the evaporator/decanter is at a higher temperature than the feed to the first stage or effect of the desalination unit. In this manner, the water may be pretreated in such a way that it will not form scale within the successive stages or effects of a desalination unit even at high temperatures, e.g. 170°-1/2°C.
If the evaporation unit is a conventional multiple effect evaporation unit, e.g. a descending unit (described in the article published in the review "Chimie Industrie Genie Chimique", volume 101, No. 5, March 1969), before the "cloudy" sea water is introduced into a first heat exchanger C 1 , it passes through the shell side of a second heat exchanger C 2 , to the tube side of which is supplied water vapor exiting the evaporator/decanter, so that the clear sea water entering the first stage of the evaporation unit is a temperature θ 2 , a temperature lower than temperature θ 1 at which sea water and the vapor leave the evaporator/decanter.
In this way, sea water exiting the evaporator/decanter is cooled by its passage through the heat exchanger C 2 with the result that it is possible to evaporate this clear sea water in the first stage of the evaporation unit by means of the vapor issuing from the evaporator/decanter at temperature θ 1 . Heat exchanger C 2 also operates to reduce the temperature of the sea water to a temperature which is definitely lower than that of the saturation point of the calcium sulfate, thereby avoiding any risk of scaling in the first stages of the evaporation unit.
The evaporator/decanter of the invention may be located inside the first stage of the evaporation/distillation installation as long as the dimensions of the lower part of the evaporator/decanter allow this. In this case, heating of the sea water solution with steam may be effected by the heating means associated with the first stage of the evaporation unit.
Other features and advantages of the present invention will become apparent from the following description of various embodiments thereof which are provided by way of non-limitative examples with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevantional view, cross-section, of an embodiment of the evaporator/decanter;
FIG. 2 is a schematic diagram of a desalination process employing a multiple effect evaporation unit;
FIG. 3 is a schematic diagram of a desalination process operating on the successive expansion system with recycling, as used in combination with the evaporator/decanter of FIG. 1; and
FIG. 4 is a schematic diagram of a desalination process employing two evaporation units in series, the first unit supplying brine from which scaling agents have been removed to the second vaporization/distillization unit.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
As previously noted, the present invention is directed to the removal of scaling agents from water in an evaporator/decanter and to a pretreatment for water to be introduced into a standard or modified desalination unit.
In FIG. 1 an embodiment of the evaporator/decanter of the present invention is generally designated by the numeral 1 and is shown as having an inner vessel 3 mounted within an outer vessel 5. The inner vessel or container 3 is provided with a generally cylindrical body portion 3a and a generally conical base portion 3b. Likewise, outer vessel or container 5 has a generally cylindrical body portion 5a and a generally cone-shaped bottom portion 5b. The outer vessel 5 is further provided with means, in the form of an inlet T 4 , for the introduction of the "cloudy" sea water containing the crystalline nuclei. The inner vessel 3 is provided with a gutter of trough 2 around its inner circumference near the upper end of the cylindrical body portion 3a. Trough 2 serves to collect the clarified sea water which is then discharged through the water discharge means T 3 . The inner vessel 3 is further provided with an inverted funnel member 7 having an upper riser or pipe 9 and a lower cone portion 11. The funnel member is rigidly mounted within the upper end portion 3c of inner vessel 3. the inner vessel 3 and the outer vessel 5 are respectively provided with crystal discharge means T 5 and T 6 .
In operation, the cloudy warm sea water is introduced through pipe T 4 and it fills the evaporator/decanter 1 to a level above the mouth of the pipe 9. The level of the liquid in the container E 1 is kept constant by means of a suitable regulating device (not shown). The regulating device may be, for example, one consisting of a float which enables the sea water to enter the container 5 through the pipe T 4 by opening a suitable valve (not shown).
Owing to the pressure prevailing in the evaporator/decanter, the sea water flashes upon entering the container 5 and part of the water is transformed into vapor which is discharged via the pipe T 1 . The sea water containing suspended crystals penetrates pipe T 2 and is decanted. The clear sea water collects in the circular gutter 2 and is discharged by pipe T 3 .
The crystals 8 which are decanted collect at the bottom of cone 3b and are discharged via pipe T 5 . Discharge means T 6 located at a low point in cone 5b enables the evaporator/decanter 1 to be emptied and also permits removal of the crystals which collect in cone 5b.
FIG. 2 depicts a desalination plant having a plurality of evaporate stages or effects including the evaporate/decanter of the present invention. The multiple effect evaporation unit 16 is provided with a series of condensers 10, 12, 14, two heat exchangers C 1 and C 2 and piping connecting the unit with the heat exchangers and the evaporator/decanter.
In the system depicted in FIG. 2 crystal nuclei coming from the evaporator/decanter by way of the pipe 20, containing the mixed discharge the pipes T 5 and T 6 , are added to the crude sea water being supplied at 18. A second portion of crystals discharged from the decanter 7 are removed from the system via pipe 22. The sea water containing the seed crystals is then progressively heated, in the condensers 10, 12 and 14 associated with different stages of an evaporation/distillation unit, to temperatures in excess of those corresponding to the limits of solubility of the alkaline earth carbonates and calcium sulfate to produce crystallization of these compounds.
The preheated water is then routed through exchanger C 2 and then exchanger C 1 , the shell side of which is supplied with steam countercurrently as indicated by the arrow. The heat exchanger C 1 is the only part of the decanting desalting installation to which heat is supplied from an auxiliary source. After exiting the tube side of heat exchanger C 1 , the sea water enters the evaporator/decanter via pipe T 4 . The water vapor issuing from the pipe T 1 of the evaporator/decanter may be used to heat the first stage of the evaporation/distillation unit 16. The clarified sea water from which the scaling salts have been removed is discharged through pipe T 3 . It is cooled in the heat exchanger C 2 and is thereafter introduced into the first stage of the evaporation unit by way of pipe 26. The concentrated brine discharged via pipe 28 is either thrown away or it may constitute a supply of non-scaling water for a second conventional evaporator, the first stage temperature of which is lower than that of the water at the output of the evaporator/decanter. Fresh condensed water is collected at 30.
As will be appreciated by those skilled in the art, the evaporator/decanter of the present invention actually operates as the first stage of the evaporation/distillation system and may be either independent of the multiple effect unit or may be fully integrated therewith as shown.
FIG. 3 shows a desalination system having two series of evaporation/distillation effects. The first series of effects S 1 is used to heat the sea water being supplied at 30. The second series of effects S 2 is used to heat both 1) the sea water entering at 32 after being mixed with the slurry of crystals supplied through line 35 from the evaporator/decanter and 2) the brine recycled via 36 from the outlet of the last stage of the series S 1 . This embodiment is also provided with a heat exchanger 38 for the clarified brine and a heat exchanger C 1 for preheating the sea water prior to entry into the evaporator/decanter. As in the embodiment of FIG. 2, the heat exchanger C 1 is supplied with live steam via 24.
In the process depicted in FIG. 3, the first stage of the multiple effect evaporation unit is heated by the water vapor exiting the top of the container 5 of the evaporator/decanter. The multiple effect units S 1 and S 2 operate with flashing and provide recycling of the brine. Before adding the seed crystals to the sea water the water is first heated by successive passage through the condensers associated with the series of effects S 1 . After the crystalline nuclei have been added the sea water is then heated to a higher temperature in a second series of condensers of multiple effect unit S 2 . This heating of the crude sea water is effected in parallel with the heating of the brine obtained at the output of the two series of effects S 1 and S 2 which is recycled to the input of the condensers in the series S 2 . The water vapor issuing from the evaporator/decanter is used to heat, at least partially, the brine obtained at the output of the last condenser crossed in the series S 2 . This brine is then emptied into the evaporation tank of the first effect of the series S 2 of evaporators and the clarified sea water coming from the evaporator/decanter is also injected into this first effect.
It is not necessary to mix seed crystals with the crude sea water in the first series of condensers of the S 1 because the temperature corresponding to the saturation point for the alkaline earth carbonates and calcium sulfate is not reached; at these low temperatures these scaling agents do not precipitate. The sea water with the admixed seed crystals and the warm brine issuing from the two series of stages S 1 and S 2 of the unit are passed in parallel through the series of condensers associated with the effects of series S 2 . This brine is approximately at the same temperature as the crude sea water in the parallel ducts. This recycling feature makes it possible to conserve heat and contributes to the economics of the system. The water vapor leaving the evaporator/decanter is used to preheat the brine before the brine is mixed with the clarified sea water leaving the evaporator/decanter. In this way, the heat contained in the vapor leaving the evaporator/decanter is utilized in heat exchanger 38. It is obviously not necessary to add anhydrite nuclei to the brine being recycled, because this brine comes from the clarified sea water from which the major part of the scaling agents have been removed.
The stages or effects of the evaporation/distillation unit operate at a lower temperature than that of the clear sea water at the output of the evaporator/decanter, and thereby are not subject to fouling by scaling.
Thus, the heat exchanger 30 which preheats the clarified brine is heated in part with vapor entering at 32 and exiting at 34 and in part by the water vapor from the flashing of sea water in the evaporator/decanter. The condensed water vapor is thereafter discharged via collector pipe 40 which collects the pure water produced in all the effects of the evaporation/distillation unit. At the output of the heat exchanger 38, the brine is mixed with clarified sea water exiting the evaporator/decanter by way of pipe T 3 and then enters the first effect of series S 2 of the evaporation/distillation unit. Excess heated crude sea water is discharged through pipe 42.
The present invention also contemplates a process wherein the evaporator/decanter is used in combination with a flash type evaporation unit having an open cycle. FIG. 4 shows an embodiment of such a process for clarifying a sea water feed to a conventional evaporation/distillation unit 50. The apparatus 50 will not be described in detail since it is a conventional unit. The clarified brine from which the greater part of the scaling agents have been removed is introduced into the unit 50 by way of the pipe 52 after passage through a heat exchanger 54. Heat exchanger 54 serves to cool the brine to a temperature suitable for feed to first condenser of the evaporation/distillation unit 50. This brine is produced by an auxiliary desalting unit 70 which serves to remove the scaling agents and which operates by flashing and with an open loop. In this unit, the sea water is supplied by way of the pipe 56 to a series of condensers where it is heated after having been mixed with anhydrite nuclei supplied by the pipe 58 from the evaporator/decanter. This heated cloudy water passes through the heat exchanger C 1 , the shell side of which is heated by steam entering at 59 and exiting at 60 and also by the water vapor which enters via the pipe T 1 from the evaporator/decanter. The pure water which is discharged from this first evaporation unit is collected in the pipe 62. The clear sea water which exits the evaporator/decanter via T 3 is introduced into the first stage of the evaporation/distillation unit 70 and a brine is obtained at 64 from which the greater part of the scaling agents have been removed. After passing through the heat exchanger 54, this brine is supplied via the pipe 52 to feed the evaporation/distillation unit 50.
The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning range of equivalency of the claims are therefore intended to be embraced therein.
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Apparatus for separating solids from a liquid suspension using an evaporator/decanter having an outer and inner vessel and an inverted funnel member housed within the inner vessel, the leg of the funnel extending through the top of the inner vessel. A gutter member, mounted around the inner circumference of the inner vessel collects the clarified water. In a process for removing scaling agents from sea water, seed crystals are added to the sea water which is then heated to a temperature above the solubility limits of the scaling agents and above the operating temperatures of a desalination unit to cause the scaling agent to crystallize on the seed crystals. The seed crystal solution is then fed into the outer vessel of the apparatus to effect removal of the crystals and produce a clarified sea water feed for the desalination unit.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 10/251,031, now abandoned, entitled “Medical Device Amenable To Fenestration”, the content of which is hereby incorporated by reference in its entirety.
FIELD OF THE INVENTION
The present invention relates to implantable medical devices. More particularly, the invention relates to means for forming a framed aperture in wall portions, or other partitions, of implantable medical devices to establish and maintain fluid communication across the wall portion of the medical device. The present invention also relates to methods of making the invention.
BACKGROUND OF THE INVENTION
Abdominal aortic aneurysms (AAAs) and thoracic aortic aneurysms (TAAs) are diagnosed in approximately 250,000 and 20,000 patients respectively each year. Left untreated, these aneurysms commonly progress to rupture resulting in death. Prior to the advent of interventional catheter-based techniques, conventional surgical treatment has been the method of treatment for these lesions. Due to the often emergent condition of these patients and the potential for significant blood loss, high morbidity and mortality rates have been associated with this type of surgery.
With the introduction of catheter-based interventional techniques, new non-surgical therapies were made available to many patients. Since the initial animal work performed by Schatz et. al., small metallic tubes (i.e., stents) have been found to be of significant benefit for patients with coronary artery and peripheral artery disease. Schatz, R. A., Palmaz, J. C., Tio, F. O., Garcia, F., Garcia, O., Reuter, S. R. “Balloon-expandable intracoronary stents in the adult dog.” Circulation 76:450-7 (1987). In an effort to treat abdominal aortic aneurysms, Parodi et. al. reported on their experience with combining the barrier properties of synthetic vascular grafts with stent technology (i.e., stent-graft) to effectively inhibit blood flow into the aneurysm sac using catheter delivery systems. Parodi, J. C., Palmaz, J. C., Barone, H. D. “Transfemoral intraluminal graft implantation for abdominal aortic aneurysms.” Ann. Vasc. Surg 5:491-9 (1991).
This technology has continued to progress with significant improvements in successful device deployment and improved patient outcomes. Despite these improvements, there are many patients for which this technology is not applicable as a result of unique anatomical or disease conditions. Specifically, in the case of AAA disease, stent-graft devices typically require some amount of healthy vessel both proximal and distal to the aneurysm sac into which to place the stent-graft. In many patients, the proximal vessel is not long enough to achieve adequate fixation. Placement of the stent-graft in a more proximal location in these patients in order to achieve adequate fixation could partially or completely occlude the renal arteries providing blood to the kidneys. A number of different device designs have been proposed to allow device fixation to the aortic vessel proximal to the renal arteries (i.e., suprarenal fixation). Widespread applicability of supra-renal fixation devices has been limited by the flexibility of these designs, morphological variation of aneurysmal neck geometry across patients, and the coverage of the renal ostia with metallic stents which can act as a nidus for thromo-embolism of the renal circulation and/or hinder subsequent interventional access to this vasculature.
A similar situation exists for TAA disease. These aneurysmal lesions are often located in close proximity to the subclavian and carotid arterial branches. When inadequate proximal vascular tissue is available for anchoring the endoprosthesis, a suitable proximal anchoring zone can be created by performing a surgical transposition prior to the interventional procedure. This surgical approach is intended to assure continued flow to all vessels. Alternative means for achieving side-branch perfusion through the wall of a stent-graft are therefore desirable.
Other clinical conditions where there would be a benefit for fluid communication through the wall of a prosthesis are those involving cardiac surgery. Arterial blood leaving the heart serves to carry oxygen to the body. In contrast, venous blood is returned to the heart via the superior and inferior vena cava after releasing oxygen to the body and absorbing carbon dioxide and other waste products. Approximately 40,000 children are born each year with congenital heart defects. These abnormalities often involve a single functional ventricle and defects in the tissues (i.e., septum) separating the right (venous) and left (arterial) side of the heart. Mixing of arterial and venous blood in these patients results in reduced oxygen carrying capacity and often shortened life expectancies.
Cardiac surgical interventions performed for the most complex congenital heart abnormalities often require multiple surgical procedures to effect the final treatment for the patient. The Fontan procedure is an example of a staged surgical treatment that is designed to overcome these significant structural heart abnormalities and isolate systemic and pulmonary circulation at the definitive treatment. “Correction de l'atresie tricuspidienne.” Fontan, F., Mounicot, F. B., Baudet, E., Simonneau, J, Gordo, J., Gouffrant, J. M. Rapport de deux cas “corriges” par l'utilisation d'une technique chirurgicale nouvelle. [“Correction” of tricuspid atresia. 2 cases “corrected” using a new surgical technic] Ann - Chir - Thorac - Cardiovasc 10:39-47 (1971). Annecchino, F. P., Fontan, F., Chauve, A., Quaegebeur, J. “Palliative reconstruction of the right ventricular outflow tract in tricuspid atresia: a report of 5 patients.” Ann - Thorac - Surg. 29:317-21 (1980). Ottenkamp, J., Rohmer, J., Quaegebeur, J. M., Brom, A. G., Fontan, F. “Nine years' experience of physiological correction of tricuspid atresia: long-term results and current surgical approach.” Thorax 37:718-26 (1982). The surgical procedures must be staged to minimize the pressure and volume loads on the remaining functional single ventricle. In the first stage procedure, a connection is created between the Superior Vena Cava (SVC) and the Pulmonary Artery (PA). This is referred to as a Hemi-Fontan or Glenn Shunt procedure. Mathur, M., Glenn, W. W. “Rational approach to the surgical management of tricuspid atresia.” Circulation 37:1162-7 (1968). This shunt reduces the degree of venous and arterial blood mixing, and improves oxygenation of the blood.
Once the pulmonary circulation and functional ventricle are sufficiently developed, a subsequent procedure is performed wherein the blood going to the right ventricle is bypassed by routing the blood in the Inferior Vena Cava (IVC) directly to the PA by way of a baffle or tube connecting the IVC to the PA. At the time of this procedure, a small hole is typically created in the side of the connection tube to allow some flow of blood into the right ventricle. This small hole is considered a temporary connection that reduces the work for the remaining ventricle when pulmonary vascular resistance is elevated. Bridges, N. D., Mayer, J. E., Lock, J. E., Jonas, R. A., Hanley, F. L., Keane, J. F., Perry, S. B., Castaneda, A. R. “Effect of baffle fenestration on outcome of the modified Fontan operation.” Circulation 86:1762-9 (1992).
The final surgical procedure involves either surgical closure or transcatheter occlusion of the temporary hole in the IVC to PA connector tube. This multi-staged conventional surgical approach for patients with complex congenital heart disease is not optimal as it puts patients at additional risk of morbidity and mortality with each subsequent surgical intervention. This risk may be reduced if the first surgical intervention can set the stage for a future minimally invasive procedure that eliminates the need for additional open-heart surgery.
Various devices and design modifications have been proposed in an effort to provide access to anatomical structures surrounding the device or to internal spaces of the device.
U.S. Pat. No. 6,428,565, issued to Wisselink, and U.S. Pat. No. 6,395,018, issued to Castaneda, each relate to stent-graft systems with pre-formed apertures to allow for side-branch access. Neither of these devices have apertures that are closed at the time of initial implant.
U.S. Pat. No. 6,398,803, issued to Layne, et. al., relates to partially covered stents having various patterns of open apertures along the length of the device. As with the Wisselink and Castaneda devices, the apertures are fully formed prior to deployment of the device.
U.S. Pat. No. 6,432,127, issued to Kim, et. al., discloses formation of an aperture in the wall of a vascular conduit through the use of a cutting tool. The conduit does not provide a deformable framework encompassing the aperture formation site. As a result, targeting the precise location of the region in which to create the aperture is difficult to visualize using conventional imaging techniques. Moreover, the aperture is not reinforced along its peripheral regions once the aperture is formed. The absence of a framework delimiting the aperture formation site precludes precise sizing of the aperture during its formation.
There remains a need for a device that initially maintains the continuity and fluid-retaining properties of a wall portion of an implantable medical device, while providing means for forming a permanent aperture in the medical device. Such a device would permit custom sizing of the aperture in situ at the implant site during surgery.
SUMMARY OF THE INVENTION
The present invention is directed to a device that is amenable to transmural fenestration. In particular, the present invention permits a permanent framed aperture to be formed in a wall, or similar partition, of implantable medical devices as a means for establishing and maintaining fluid communication across the wall of the medical device following implantation. The present invention provides a breachable barrier material that initially maintains the continuity and any fluid-retaining properties of the wall of the medical device. The breachable barrier material fully covers an opening delimited by a framework. In use, the breachable barrier material is breached with a surgical instrument and the shape of the framework altered to enlarge, or otherwise alter, the area of the opening. In the process, the opening becomes uncovered and accessible to flow of fluid through the opening. The altered framework provides structural reinforcement to peripheral regions (e.g., circumferential) of the enlarged opening and forms a permanent aperture in the wall of the medical device. The altered framework can also be used to provide a secure anchoring site for ancillary medical devices. The permanent aperture can be formed in the wall of the implantable medical device at the time of surgical or catheter-based intervention or at a later date through the use of interventional or surgical techniques.
The present invention is particularly suited for use with vascular prostheses, and other implantable medical devices providing fluid containment or fluid partitioning, that can benefit from the formation of one or more permanent apertures in the devices at the implantation site. With stent-grafts spanning an aneurysm, for example, the invention can provide a framed aperture in the wall of the stent-graft for side-branches or drainage sites. Vascular grafts can be bypassed or bifurcated in-situ with the present invention. The invention can also be used with surgically implanted cardiovascular patches to provide perfusion or other access to the heart and vascular system.
The present invention can be added to an implantable medical device following its construction, or included in the manufacture of the device as an integral component. The breachable barrier material of the present invention is made of implantable polymers that are readily breached, perforated, or otherwise structurally disrupted with surgical instruments. The breachable barrier material can also be made of polymers that are structurally disrupted through degradation and absorption by the body of the implant recipient. The polymers of the breachable barrier material can be incorporated with filler materials to assist in breaching the barrier material or to facilitate visualization of the aperture region in an implant recipient.
The framework is made of implantable metallic or polymeric materials that can be altered in shape. These framework materials can be deformed or otherwise altered in shape with surgical instruments or have shape-memory properties that permit the framework to assume different shapes without the use of an instrument. The framework materials are shaped in various ways to assist in the combined roles of structurally reinforcing the breachable barrier material and the opening, being capable of reconfiguration, and providing a permanent framed aperture.
In one surgical method, an implantable medical device utilizing the present invention is placed at a surgical site with conventional or interventional surgical techniques. Once the correct position of the medical device is confirmed, a catheter guide-wire, or other surgical instrument, is used to breach the breachable barrier material and begin to uncover the covered opening. An expandable balloon catheter in a deflated configuration is then inserted into the partially uncovered opening and inflated. As the balloon catheter is inflated, it expands in diameter, altering the shape of the framework and displacing the remaining barrier material from the area of the opening. When the framework has been reconfigured as desired, the balloon catheter is deflated and removed from the opening. This leaves a permanent framed aperture in the wall of the medical device. The permanent aperture can provide immediate therapies and surgical remedies, such as branch vessel perfusion, or co-operate with other medical devices.
In one embodiment, the present invention is an implantable medical device comprising a framework delimiting an opening having a first area and a breachable barrier material fully covering said opening, wherein a permanent aperture having a second area is formed following breach of said breachable material and said framework is adaptable to be altered in shape.
In another embodiment, the present invention is an implantable medical device comprising a continuous wall, at least one framework in said wall delimiting an opening having a first area, a breachable barrier material fully covering said opening, wherein a permanent aperture having a second area is formed following breach of said breachable material and said framework is adaptable to be altered in shape and have a reinforced peripheral region in said continuous wall.
Further aspects and advantages of the present invention will be apparent to those skilled in the art after reading and understanding the detailed description of preferred embodiments set forth hereinbelow and after viewing the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing summary, as well as the following detailed description of a preferred embodiment of the invention, will be better understood when read in conjunction with the appended drawings. For purposes of illustrating the invention, there is shown in the drawings an embodiment that is presently preferred. It should be understood, however, that the invention is not limited to the precise arrangement and instrumentality shown. In the drawings:
FIG. 1A illustrates a top view of the present invention.
FIGS. 1B-1D illustrate a side view of the present invention.
FIGS. 2A-2 E illustrate the present invention in operation.
FIG. 3A illustrates an embodiment of the present invention incorporated into a wall of a tubular medical device.
FIG. 3B illustrates an embodiment of the present invention incorporated into a planar material that is attached to a wall of a tubular medical device.
FIG. 4 illustrates an embodiment of the present invention incorporated into a medical device.
FIG. 4A illustrates an embodiment of the present invention placed in a discrete location relative to scaffolding and wall elements of an implantable medical device.
FIG. 5 illustrates an abdominal aortic aneurysm.
FIG. 6 illustrates a stent-graft incorporating an embodiment of the present invention placed in the region of an abdominal aortic aneurysm.
FIGS. 7A-7D illustrate the present invention being utilized to provide perfusion to side branches of a blood vessel.
FIG. 7E illustrates an embodiment of the present invention serving as attachment means for another medical device.
FIGS. 8A-8C illustrate the framework component of the present invention in various non-limiting shapes.
FIG. 9 illustrates the framework component of the present invention in the form of an array.
FIG. 10 illustrates the framework component of the present invention in the form of an array.
FIG. 11 illustrates a method of constructing the breachable barrier material in an embodiment of the present invention.
FIG. 12 is an exploded view of an embodiment of the present invention under construction.
FIG. 13 is a perspective view of an embodiment of the present invention.
The accompanying diagrams include various anatomical structures and associated clinical pathologies that are identified as follows:
AA=Abdominal Aorta
RA=Renal Artery
IA=Iliac Artery
AAA=Abdominal Aortic Aneurysm
DETAILED DESCRIPTION OF THE INVENTION
The present invention can be used in combination with a variety of implantable fluid-containing medical devices to establish fluid communication across a wall, or other partition, in the devices. In many situations, the present invention is employed at the time the medical device is implanted. In other instances, the present invention is accessed and utilized after the medical device has been implanted for a period of time. The present invention can also be used before the implant procedure begins.
FIG. 1A is a top view of an embodiment of the present invention 10 incorporated into an implantable patch material 12 . FIG. 1B is a side view of this embodiment generally illustrating the relationship of the components. In this embodiment, a framework 14 is surrounded by a layer of implantable polymeric material 18 . The framework 14 delimits an opening 16 that is fully covered with a breachable barrier material 17 . The polymer layer 18 is sandwiched between two layers of implantable patch material 12 , 13 so as to reveal the framework 14 , opening 16 , and breachable barrier material 17 of the present invention. In similar embodiments of the present invention, the implantable patch material or other wall components are considered part of the invention. In addition to implantable medical devices having planar configurations, implantable medical devices having tubular configurations are also suitable for use with the present invention. Tubular medical devices are generally cylindrical in shape and not confined to having parallel walls. In addition, tubular medical devices have geometries with at least one inlet and at least one outlet.
The shape of the framework 14 is chosen to provide structural support to the breachable barrier material 17 while it fully covers opening 16 . The shape and composition of the framework also allows the framework to be readily deformed and displaced to peripheral regions of the opening to form a permanent framed aperture. The particular shape of the framework illustrated in FIG. 1A , et. al., is preferred but not limiting. For example, FIGS. 8B and 8C illustrate frameworks having circular configurations 70 incorporating varying numbers of peaks 76 and valleys 78 . It is also contemplated in the present invention that the distance between the peaks 76 and valleys 78 (i.e., amplitude) can be varied broadly, thereby enabling a wide range of framework geometries to be formed. In addition to enhancing support for the breachable barrier material with these framework designs, a wide range of aperture sizes can be achieved with these designs. Supporting leg struts 74 can also be incorporated into the framework design to enhance attachment to surrounding wall materials. Other non-circular configurations 79 of the framework 14 are also contemplated. Furthermore, FIGS. 9 and 10 illustrate that the framework can be in the form of an array of openings. These embodiments provide a choice of locations for the framed aperture as well as the number of framed apertures.
FIGS. 2A-2E illustrate the construct of FIGS. 1A and 1B in use. FIG. 2A is a perspective view of the construct as it might appear at an implantation site. FIG. 2B shows a guide wire 20 from a catheter, or other device, having penetrated and breached the breachable barrier material 17 . FIG. 2C depicts an expandable balloon catheter 22 in a deflated state being introduced through the breached barrier material into opening 16 with guide wire 20 . FIG. 2D illustrates inflation of the expandable balloon catheter 22 and deformation of framework 14 . As the framework 14 is deformed, opening 16 is enlarged and expanded in area. Following deflation and removal of the balloon catheter, FIG. 2E shows the resulting permanent aperture 24 framed with altered framework 14 in implantable patch material 12 .
FIG. 3A illustrates the present invention 15 as a component of a tubular vascular graft 30 . In this embodiment, framework 14 delimiting opening 16 is fully covered by breachable barrier material 17 and incorporated into wall portion 32 of vascular graft 30 . When the invention is operated, fluid communication across wall portion 32 to luminal space 34 is established.
FIG. 3B illustrates an embodiment of the present invention 19 having an implantable patch material 11 component. The implantable patch material is attached to an implantable vascular prosthesis 30 by sewing. Other suitable means of attaching the present invention to a wall of an implantable medical device include, but are not limited to, adhering, ultrasonic or radio frequency welding, lamination, stapling, and covering the medical device with a membrane or film to include the present invention.
FIG. 4 illustrates an embodiment of the present invention 44 incorporated into an implantable tubular endovascular device 40 . In this embodiment, the endovascular device 40 is a bifurcated design commonly used to treat aortic aneurysms and includes a main body, or trunk, portion 50 and two leg portions 52 , 54 . The endovascular device has a stent frame 42 and wall means 48 . Several fully covered framework elements of the present invention are incorporated into the wall means 48 of the stent-graft 40 . As seen in FIG. 4 , there is a longitudinal displacement between the present invention and the support elements (i.e., scaffolding) of the stent-graft. This embodiment of the present invention provides multiple sites for forming side branches in stent-grafts and other endovascular devices as means for providing selective perfusion and/or drainage of the implantation site.
In embodiments of the present invention used in combination with stent-grafts, and other implantable medical devices utilizing support elements (i.e., scaffolding), the framework component of the present invention is preferably incorporated into the device separately from the support elements. As shown in FIG. 4A , the framework of the present invention underlies and is discrete from the support elements of the implantable medical device. The location of the present invention is not limited to contact or close proximity to support elements or wall components of an implantable medical device. Indeed, the present invention can be positioned in any desired location in an implantable medical device.
A clinical application of the embodiment illustrated in FIG. 4 is depicted in FIGS. 5 and 6 . A typical abdominal aortic aneurysm (AAA) is shown in FIG. 5 with the proximal aorta (AA) leading to renal artery (RA) branches and distal iliac arteries (IAs). In cases where the disease condition or aortic anatomy does not provide sufficient healthy vessel upon which to achieve device fixation at implant, it is often necessary to utilize the AA segment proximal to the RAs. In this suprarenal implant position, an appropriate stent-graft 40 fixation can be achieved and effective AAA exclusion as shown in FIG. 6 . In this configuration however, the barrier properties of the stent-graft wall 48 occlude blood flow to the branching RA on both sides. In order to achieve RA perfusion, one or more units 44 of the present invention are selected and utilized.
The interventional procedure required to access and operate the present invention is illustrated in FIGS. 7A-7D . Following deployment of stent graft 40 , a guide catheter 36 is positioned under fluoroscopic guidance to direct a guide-wire 20 toward the center of one of the plurality of available inventions 44 that is in appropriate alignment with the RA. Following guide-wire 20 breach of the breachable barrier material 16 , the framework 14 is altered in shape to the desired aperture size using a balloon catheter 22 . Further inflation of the balloon 22 achieves the desired deformation of the framework 14 and formation of a permanent framed aperture 64 having a size appropriate for the RA. Once formed, the permanent framed aperture 64 provides for RA blood perfusion 62 in accordance with normal AA blood flow 60 .
The present invention can be constructed of a variety of implantable materials. The breachable barrier material has a composition, structure, and/or thickness sufficient to at least partially bar liquids, including blood and other physiological fluids, from crossing the material, yet have sufficient structural weakness to be readily breached, perforated, or otherwise structurally disrupted with surgical instruments, or the like. The breachable barrier material can be made of non-biodegradable polymers, bio-degradable polymers, and elastomers, either alone or in combination. Elastomers in the breachable barrier materials can augment uncovering of the fully covered opening following breach of the barrier material. The breachable barrier material can be provided with filler materials that also augment breaching of the barrier material or assist in locating the invention at an implantation site.
Suitable surgical instruments or tools for use in breaching the barrier material at an implantation site include, but are not limited to, guide-wires, Colapinto® needles, Rotablators®, and other ablation instruments utilizing radio-frequency energy, ultrasonic sound, microwave energy, or laser light.
Suitable non-biodegradable polymers include, but are not limited to, polyester, polytetrafluoroethylene, polyamide, and polyurethane. The preferred material for the breachable barrier material is a porous expanded, or stretched, polytetrafluoroethylene material. Suitable bio-degradable polymers include, but are not limited to, materials made of polymers or copolymers possessing one or more of the following monomeric components: glycolide (glycolic acid); lactide (d-lactide, I-lactide, d,l-lactide); trimethylene carbonate; p-dioxanone; caprolactone, and hydroxybutyrate, hydroxyvalerate. Elastomeric materials suitable for use in the present invention include, but are not limited to, fluoroelastomers, polyurethane. Suitable filler materials for incorporation into the breachable barrier material include, but are not limited to, graphite, titanium oxide (TiO), barium, vitamin E, gadolinium, lossy materials, and other radio-opaque compositions.
The breachable barrier material can be applied to the framework as a single layer or in multiple layers. When using multiple layers of breachable barrier material, it is preferred to orient the individual layers in different directions (see e.g. FIG. 11 ).
The framework is made of materials that are capable of supporting the breachable barrier material while the barrier material is fully covering the opening delimited by the framework. The materials of the framework permit the framework to be readily shaped, reshaped, or otherwise altered in configuration while the invention is located at an implantation site. The framework can be made of malleable materials, plastically deformable materials, and/or self-expanding (i.e., super-elastic) metals or polymers. When materials are used that do not lend themselves to visualization with fluoroscopy, x-ray imagining, magnetic resonance imaging, etc., radio-opaque or other imaging compounds can be introduced into the framework materials.
The materials of the framework also need to be sufficiently resilient to provide permanent reinforcement of peripheral regions of the aperture under physiological conditions. In addition to providing structural support to peripheral regions of the aperture portion of the invention, the framework component can serve as anchoring means for other medical devices 90 attached thereto (e.g., FIG. 7E ).
Suitable materials for the framework include, but are not limited to, implantable metals such as gold, silver, tantalum, tungsten, and chromium, implantable metal alloys such as stainless steel, nitinol metal, and implantable polymers such as polyurethanes, fluorinated ethylene propylene, and polytetrafluoroethylene. The framework can be made by molding, casting, laser cutting and/or laser machining, stamping, photo-etching, wire-forming, electrical discharge machining (EDM), bent wire techniques, or other suitable fabrication method.
In embodiments of the present invention that include a patch, tube, or other walled component, essentially any implantable material can be used for the component. Suitable materials include but are not limited to, implantable metals, implantable metal alloys, implantable polymers such as polyester (Dacron®), polyamide (Nylon), polytetrafluoroethylene, silicone, and polyurethane.
The present invention can be constructed in a variety of ways. The invention can be made by attaching the breachable barrier material to the framework material with adhesives, heat, pressure, and/or ultrasonic welding. In turn, the breachable barrier material can be attached to an implantable medical device with similar methodologies. The invention can also be incorporated into an implantable medical device by molding, sewing, wrapping with a film or membrane, and/or mechanical fixation.
An implantable medical device made of an expanded polytetrafluoroethylene (ePTFE) in the form of a tube or sheet can be supplied with an embodiment of the present invention by first cutting a hole in the ePTFE slightly smaller than the largest diameter of the framework component. Next, a powder coating of fluorinated ethylene propylene (FEP) is applied to both sides of the framework material and the framework material placed over the hole in the ePTFE material. A suitably sized piece of breachable barrier material is placed over the framework component. Heat and pressure are applied to the combination to attach the materials together.
Another method of attaching the present invention to an implantable medical device involves applying an adhesive material, such a room temperature vulcanizing (RTV) silicone, to both sides of the framework material and pressing one side of the framework onto a wall of the medical device having a suitably sized hole formed therein. A suitable breachable barrier material is then pressed onto the other adhesive-coated side of the framework component. Any excess barrier material is trimmed away from the framework to complete the installation.
Yet another method of attaching the present invention to an implantable medical device involves placing a framework component over a suitably sized hole in a wall of the medical device and wrapping one or more layers of a biocompatible film over the framework component. In this embodiment, the wrapped film layer(s) can also serve as the breachable barrier material. The film wrapping material can be further secured by heating the construction.
For implantable medical devices having a wall element in the form of a meshwork, the present invention can be attached to the medical device in such a way that the opening is accessibly through holes in the meshwork. In this embodiment, an adhesive-coated framework material is placed on a breachable barrier material. Additional adhesive is placed on perimeter regions of the barrier material. A meshwork device is placed over this combination so the opening of the present invention is accessible through one or more holes in the meshwork. Pressure is applied to the construct to adhere the components together. A preferred implantable medical device is a woven mesh material commercially available from Davol, Inc. under the trade name Bard® Marlex™ Mesh—Monofilament Knitted Polypropylene (Catalog No. 011265).
These construction methodologies are exemplary and are not intended to limit the scope of the present invention.
EXAMPLES
Without intending to limit the scope of the present invention, the apparatus and method of production of the present invention may be better understood by referring to the following examples.
Example 1
A planar sheet embodiment of the present invention, approximately 8.3 cm (3.25″) by 13.3 cm (5.25″), was constructed as follows. A first layer of an expanded polytetrafluoroethylene (ePTFE) sheet material having a thickness of about 0.4 mm was obtained from the Medical Products Division of W.L. Gore & Associates, Inc., Flagstaff, Ariz. under the tradename GORE-TEX® Cardiovascular Patch as part number 1800610004 ( FIG. 12 , part A 1 ).
A second layer of a fluoro-elastomeric sheet material composed of a thermoplastic copolymer of tetrafluoroethylene (TFE) and perfluoro(methyl vinyl ether) (PMVE) was constructed by compression molding the crumb form of the copolymer at a temperature of about 250° C. to form a sheet about 0.2 mm (0.008″) in thickness ( FIG. 12 , part A 3 ). The resulting material had the attributes described in TABLE 1 below.
A third layer of sheet material ( FIG. 12 , part A 4 ) is composed of ePTFE made according to U.S. Pat. No. 4,482,516, issued to Gore. The sheet material was approximately 0.17 mm thick with an average fibril length of greater than about 10 microns.
A sheet of medical grade 316 stainless steel was obtained from Laserage Technologies, Inc., Waukegan, Ill. for use in constructing a framework. The framework was laser machined into an undulating pattern having a continuous, generally circular, ringed configuration ( FIG. 12 , part A 2 ). The thickness of the framework was about 0.4 mm (0.016″). The minimum distance between individual framework elements located opposite one another in the opening delimited by the framework was about 0.2 mm (0.008″).
These four components were aligned together as shown in FIG. 12 . Components 100 , 102 , 103 , and 104 were placed between layers of high temperature padding material and aluminum plates ( FIG. 12 , parts 105 , 106 ). The aluminum plates were approximately 15.2 cm (6″) square and 0.062″ thick. The high temperature padding material 105 was made of GORE-TEX® Soft Tissue Patch having a thickness of about 2 mm (0.079″) available from the Medical Products Division of W.L. Gore & Associates, Inc., Flagstaff, Ariz. as part number 1310015020. The assembly was placed in a heated Carver press and laminated together in the arrangement shown in FIG. 12 for about 5 minutes, at about 200° C. with a pressure of about 0.5 Mpa (80 lb/in 2 ). Following the compression cycle in the press, the padding material was discarded.
A 4 mm hole was then cut though all three layers of material at the center point of the reinforcement element using a 4 mm sharpened coring punch. Four layers of high strength ePTFE film made according to U.S. Pat. No. 5,476,589, issued to Bacino, were obtained and oriented at 90 degree angles with respect to one another (Figure C). A layer of discontinuous fluorinated ethylene propylene (FEP) coating was placed between each layer of ePTFE material. These combined materials were placed over the cutout hole and secured in place using a heated soldering iron applied around the outer perimeter of the cutout hole. Excess film material was than trimmed from the final assembly and the edges tacked down thoroughly with the heated soldering iron. The resulting article is shown in FIG. 13 .
TABLE 1
Characteristic
Target
PMVE wt %
about 60%
TFE wt %
About 40%
100% Secant Modulus*
About 2.1-2.2 MPa
Softening Temperature
<275° C.
Thermal Degradation Temp.
>300° C.
Melt Flow Index**
>2.0
Durometer
60-80 Shore A
*as per ASTM D412-98, using ½ scale Type IV dogbone with 250 mm/min crosshead speed and approximately 40 mm grip separation.
**grams per 10 minutes, 10 kg, 325° C.
Example 2
This example describes a tubular vascular graft having the article of Example 1 incorporated into the wall of the tubular graft. The article of Example 1 was trimmed and sewn into a corresponding hole cut through the wall of an ePTFE vascular graft. The ePTFE vascular graft was a GORE-TEX® Vascular Graft available from the Medical Products Division of W.L. Gore & Associates, Inc., Flagstaff, Ariz. as part number SA1604. The article from Example 1 was sewn into the corresponding hole of the tubular construct with an ePTFE suture material obtained from Medical Products Division of W.L. Gore & Associates, Inc. Flagstaff, Ariz. under the tradename GORE-TEX® Suture as part number CV-5. The resulting article is shown in FIG. 3B .
Accurate and illustrative examples of the invention have been described in detail however, it is readily foreseen that numerous modifications may be made to these examples.
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The present invention is directed to a device that permits a permanent aperture to be formed in a wall, or other partition, of an implantable medical device. The present invention maintains the continuity and fluid-retaining properties of the implantable medical device by providing a breachable barrier material fully covering an opening delimited by a deformable framework. The invention is accessed with conventional interventional surgical instruments that disrupt and displace the barrier material. Following disruption of the barrier material, the opening is enlarged with surgical instruments to form a permanent framed aperture in the wall of the implantable medical device. The permanent framed aperture provides fluid communication across the wall of the implantable medical device.
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CROSS-REFERENCE TO RFELATED APPLICATIONS
This application claims benefit under 35 U.S.C. §119(e) of provisional U.S. patent application No. 60/845,314 filed Sep. 18, 2006.
The Contents of the above-referenced patent applications is herein incorporated by reference in its entirety.
FIELD OF THE INVENTION
The present invention relates to chemical compounds that are useful, for example, as protein kinase inhibitors for treating cancer, neurological disorders, autoimmune disorders, and other diseases, and methods of using such compounds.
BACKGROUND OF THE INVENTION
Homeostasis requires signaling between cells to coordinate activities such as cellular proliferation and differentiation. Inappropriate signaling can cause or exacerbate immune system pathologies, such as allergies, autoimmune diseases, and inflammation, as well as neurological and cardiovascular maladies. In particular, cancer, the uncontrolled proliferation of cells, is strongly associated with breakdown in normal cellular signaling. Signaling often involves catalyzed transfer of phosphoryl groups to and from serine, threonine, and tyrosine residues on proteins as part of signal transduction, a step catalyzed by enzymes called protein kinases. For this reason, efforts to treat cancer and other diseases have directed attention to inhibition of protein kinases.
CK2, an essential serine/threonine protein kinase, until recently has not been considered as a possible target in cancer chemotherapy, but a wide variety of cancers exhibit elevated levels of CK2 activity that correlate with the aggressiveness of tumor growth. Furthermore, decreasing CK2 activity, through use of small molecules, dominant negative overexpression of kinase inactive mutants, anti-sense methods, or small interfering RNAs, decreases cellular proliferation, increases the level of apoptosis in cancer cells, and eradicates the PC3 human prostate cancer cells from tumor-bearing mice. Existing C2 inhibitors such as emodin, coumarins, TBB (triazole), quinazolines, DRB and quercetin, however, while useful for laboratory studies, lack the qualities of a clinically useful chemotherapeutic agent.
A need remains, therefore, for compounds that inhibit CK2 activity for treating pathologies associated with phosphorylation catalyzed by this protein kinase.
SUMMARY OF THE INVENTION
One aspect of the present invention provides a new class of protein kinase inhibitors based upon macrocyclic pyrazolo[1,5-a][1,3,5]triazine and pyrazolo[1,5-a]pyrimidine compounds, methods of using them, pharmaceutically acceptable prodrugs, pharmaceutically active metabolites, and pharmaceutically acceptable salts thereof. Such compounds, prodrugs, metabolites, polymorphs, and pharmaceutically acceptable salts thereof are collectively referred to as “agents.”
The invention also relates to pharmaceutical compositions comprising an effective amount of an agent with one or more pharmaceutically acceptable carriers.
Thus, the inventive agents and pharmaceutical compositions containing such agents are useful in treating various diseases including but not limited to those associated with uncontrolled or un-wanted cellular proliferation such as cancer, autoimmune diseases, viral diseases, fungal diseases, neurodegenerative disorders and cardiovascular diseases.
Preferred agents modulate and/or inhibit the activity of CK2 protein kinase. Thus, the pharmaceutical compositions containing such agents are useful in treating diseases mediated by kinase activity, such as cancer.
The invention relates generally to compounds of Formula (I), as well as prodrugs, pharmaceutically active metabolites, polymorphs, and pharmaceutically acceptable salts thereof:
wherein
R1 is alkyl, alkenyl, alkynyl, aryl, or heteroaryl.
R2 is hydrogen, alkyl, alkenyl, alkynyl, aryl, or heteroaryl;
R3 groups are independently hydrogen, optionally substituted alkyl, alkenyl, alkynyl, aryl, heteroaryl, or halo:
(C) is a group selected from optionally substituted alkyl, alkenyl and alkynyl where n=2-6
X is CH or N.
The invention also relates to methods of treating proliferative diseases such as cancer, auto immune diseases, viral diseases, fungal diseases, neurodegenerative disorders and cardiovascular diseases, comprising administration of effective amounts of an agent of the invention to a subject in need of such treatment.
The invention further relates to methods of modulating and/or inhibiting the protein kinase activity of CK2 by administering a compound of Formula (I) or a pharmaceutically acceptable salt, pharmaceutically acceptable prodrug, or pharmaceutically acceptable salt of such compound or metabolite thereof.
DETAILED DESCRIPTION OF THE INVENTION
Unless otherwise specified, technical terms here take their usual meanings, specifically those specified in the McGraw-Hill Dictionary of Scientific and Technical Terms, 6th edition.
“Alkyl” refers to straight or branched hydrocarbon chains containing from 1 to 8 carbon atoms, while “alkylene” and “alkynyl” refer to the corresponding chains containing a double- or triple bond, respectively. Alkyl, alkylene, and alkynyl groups may be optionally substituted with one or more substituents selected from the group consisting of mercapto, nitro, cyano, azido and halo.
“Heteroaryl” refers to 5- and 6-membered aromatic rings having one or more heteroatoms selected independently from N, O, and S.
In preferred embodiments of the invention, R1 is aryl, preferably substituted aryl, more preferably substituted phenyl. It has been found that compounds in which R1 is N-alkyl-N-alkylpyrrolidinyl-carbonyl-phenyl (e.g., N-methyl-N-(1-methyl-pyrrolidinyl)-carbonyl)-phenyl, as in compound 11g) or N-alkyl-N-alkylaminoalkyl (e.g., N-methyl-N-ethylaminoethyl, as in compound 11s) are particularly useful. In certain preferred compounds, each R2 and R3 group is hydrogen, (C) is alkyl, n=4, and/or X is N.
Pyrimidine-(X═C) and triazine-based (X═N) compounds of Formula (I) are useful, for example, for influencing the activity of protein kinases. More particularly, the compounds are useful as anti-proliferation agents, thus providing treatments for cancer or other diseases associated with cellular proliferation mediated by protein kinases.
The inventive agents may be prepared by synthetic schemes described below. Triazine-based compounds of Formula (I), for example, can be prepared according to Scheme 1:
Synthesis of such compounds started from dicyano compounds (1). Treatment with NaH followed by ethylformate gave intermediate 2-formyl-dinitrile derivatives, which on treatment with hydrazine cyclized to provide 4-substituted amino pyrazoles (2). Compounds (2) were then treated with ethoxycarbonylisothiocyanate to form thiourea intermediates that spontaneously cyclize under basic conditions to provide compounds (3).
Benzylation followed by chlorination of compounds (3) gives corresponding compounds (4) and (5). The chloro group of compounds (5) was then replaced by a primary amine under mild condition to provide (6). Treatment of compounds (6) with mCPBA oxidized the benzylsulfanyl groups to the corresponding benzylsulfonyl ones (7). The activated benzylsulfonyl group of com-pounds (7) was then displaced by phenyl diamines to form compounds (8).
Treatment of compounds (8) with HCl gas in methanol gave compounds (9), which upon hydrolysis in basic conditions afforded compounds (10). Treatment of compounds (10) with coupling reagents afforded the desired macrocyclic compounds (11).
In a similar manner, pyrimidine-based (X═CH) compounds of Formula (I) were prepared ac-cording to Scheme 2:
4-Substituted amino pyrazole (2) was first treated with chlorocarbonyl-acetic acid ethyl ester to give the diacylated intermediates, which were then cyclized in the presence of base to compounds (12). Dichlorination gave compounds (13), after which amine displacements provided compounds (14 and 15). Treatment of compounds (15) with HCl gas in methanol and refluxing in methanol gave compounds (16). Alkaline hydrolysis gave compounds (17) and macrocycliza-tion afforded final product (18).
Pharmaceutically acceptable salts and/or solvates of compounds of the present invention may also be used. Such salts include those formed from, for example, hydrochloric, hydrobromic, sulfuric, phosphoric, nitric, fumaric, acetic, propionic, succinic, glycolic, maleic, tartaric, citric, malonic, and methanesulfonic acids.
Certain compounds may include a chiral center, in which case each enantiomer as well as the corresponding racemate is encompassed in the present invention.
The present invention also is directed to pharmaceutical formulations that include the inventive compounds, regardless of the intended mode of administration.
Therapeutic dosages of compounds of the present inventions can be readily determined by methods well-known in the art.
EXAMPLES
In the examples described below, unless otherwise indicated, all parts and percentages are by weight. Reagents were purchased from commercial suppliers such as Aldrich Chemical Company or Lancaster Synthesis, and were used without further purification unless otherwise indicated.
The reactions set forth below were done generally under a positive pressure of nitrogen or with drying tube, at ambient temperature (unless otherwise stated), in anhydrous solvents, and the re-action flasks were fitted with rubber septa for the introduction of substrates and reagents via syringe. The reactions were assayed by TLC, HPLC, LC/MS or NMR and terminated as judged by the consumption of starting material.
Example 1
5-(5-Amino-1H-Pyrazol-4-YL)-Pentanenitrile (2)
To a solution of 1,5-dicyanopentane (1) (6.5 mL, 50 mmol) and ethyl formate (20 mL, 250 mmol) in dry diethyl ether (200 mL), sodium hydride (60%, 4 g. 100 mmol) was added. The re-action mixture was refluxed for four h, cooled to room temperature filtered and rinsed with ether and dried. To a solution of above obtained white solid in 80% ethanol/water was added hydrazine hydrochloride (6.29 g. 61 mmol). The reaction mixture was adjusted to pH 3 with concentrated HCl and then refluxed for 2 h, cooled to room temperature and neutralized with NaHCO3. Solvent was removed under reduced pressure and the residue was dried in vacuum. The residue was suspended in ethanol and filtered. The filtrate was concentrated, dissolved in 5% MeOH/CH2C12, filtered through a short silica gel column, rinsed with 5% MeOH/CH2C12 and concentrated to give 5-(5-amino-1H-pyrazol-4-yl)-pentanenitrile 2 as a oil.
LCMS(API-ES) m/z: 164.2, 165.1 [M+H+]; 163.1 [M−H+].
Example 2
5-(4-Hydroxy-2-Mercapto-Pyrazolo[1,5-A][1,3,5]Triazin-8-YL)-Pentanenitrile (3)
To a solution of compound (2) (4.6 g. 14 mmol) in EtOAc (50 mL) was added Ethoxycarbonyli-sothiocyanate (1.69 mL, 15 mmol) drop wise with stirring at ambient temperature. The reaction mixture was refluxed for 2 h, and cooled to room temperature. Ammonium hydroxide (10 mL) was added and the reaction mixture stirred at room temperature for 20 h. The reaction mixture was extracted twice with 1 M NaOH and the aqueous extractions were combined, acidified with concentrate HCl, and extracted twice with EtOAc. The combined organic extracts were dried with anhydrous Na2SO4 and concentrated to give 5-(4-hydroxy-2-mercapto-pyrazolo[1,5-a][1,3,5]triazin-8-yl)-pentanenitrile (3), as a white solid (2.5 g, 67%).
LCMS(API-ES) m/z: 249.3, 249.9 [M+H+]; 247.9 [M−H+].
Example 3
5-(2-Benzylsulfanyl-4-Hydroxy-Pyrazolo[1,5-A][1,3,5]Triazin-8-YL)-Pentanenitrile (4)
A solution of compound (3) (5.3 g, 21,3 mmol) in N-methylpyrrolidinone (30 mL) was degassed in vacuum for 5 min. Benzyl bromide (2.28 mL, 19. 1 mmol) and DIEA (4.4 mL, 25 mmol) were added and the reaction mixture was stirred at room temperature under vacuum for 30 min. Sol-vent was removed under reduced pressure and the residue was diluted with EtOAc. The acetate solution was washed with 1 M HCl followed by brine. Organic extract was dried over anhydrous Na2 SO4, filtered, and concentrated. The residue was triturated in a mixture solvent of hexane, ether and EtOAc, and filtered to give 5-(2-benzylsulfanyl-4-hydroxy-pyrazolo[1,5-a][1,3,5]triazin-8-yl)-pentanenitrile (4) as a solid (6.0 g. 93%).
LCMS(API-ES) m/z: 339.4, 340.0 [M+H+]; 338.0 [M−H+].
Example 4
5-(2-Benzylsulfanyl-4-Chloro-Pyrazolol [1,5-A][1,3,5]Triazin-8-YL)-Pentanenitrile (5)
A solution of compound (4) (6.0 g, 17.7 mmol) and N,N-dimethylaniline (2.24 mL, 17.7 mmol) in phosphorus oxychloride (20 mL) was heated to reflux in a sealed tube for 1 h. Solvent was removed and the residue was dissolved in EtOAc (200 mL) and washed with saturated aqueous NaHCO3, dilute HCl, followed by brine, dried over anhydrous Na2 SO4, filtered and concentrated to give 5-(2-benzylsulfanyl-4-chloro-pyrazolo[1,5-a][1,3,5]triazin-8-yl)-pentanenitrile (5), which was used directly for the next step.
LCMS(API-ES) m/z: 357.8. 358.0. 360.0 [M+H+].
Example 5
5-(2-Benzylsulfanyl-4-Cyclopropylamino-Pyrazolo-1,5-A][1,3,5]Triazin-8-YL)-Pentanenitrile (6A)
A solution of compound (5) and cyclopropylamine (1.2 g. 17.7 mmol) in anhydrous ethanol (10 mL) was stirred for 0.5 h at ambient temperature. The mixture was then diluted with EtOAc (200 mL), washed with saturated aqueous NaHCO3 and brine and dried over anhydrous Na2 SO4. Removal of the solvent provided 5-(2-benzylsulfanyl-4-cyclopropylamino-pyrazolo[1,5-a][1,3,5]triazin-8-yl)-pentanenitrile (6) (4.3 g. 65% in two steps).
LCMS(API-ES) m/z: 378: 379 [M+H+].
Example 6
5-(4-Cyclopropylamino-2-Phenylmethanesulfonylmethanesulfonyl-Pyrazolo[1,5-A][1,3,5]Triazin-8-YL)-Pentanenitrile (7A)
To a solution of compound (6a) (3.78 g, 10 mmol) in CH2Cl2 (200 mL) was added mCPBA (5.5 g, 22 mmol, 77%). The reaction mixture was stirred for 2 h and filtered. The filtrate was washed with saturated NaHCO3 followed by brine and dried over anhydrous Na2SO4. Removal of the solvent provided 5-(4-cyclopropylamino-2-phenylmethanesulfonyl-pyrazolo [1,5-all 1,3,5]triazin-8-yl)-pentanenitrile 7a as a solid (3.5 g, 85%).
LCMS(API-ES) m/z: 410.15. 411.0 [M+H+]; 409.0 [M−H+].
Example 7
5-[2-(3-Amino-Phenylamino)-4-Cyclopropylamino-Pyrazolo[1,5-A][1,3,5]Triazin-8-YLI-Pentanenitrile (8A)
A mixture of compound (7a) (0.41 g. 1 mmol), and benzene-1,3-diamine (2.16 g. 20 mmol) in 50 mL of AcOH was heated at 70° C. for 2 h. The mixture was then concentrated, and the residue neutralized with NaHCO3 and extracted with EtOAc. The acetate solution was then washed by citric acid (10%), followed by brine, dried over Na2 SO4 and concentrated to give 3-[2-(3-amino-phenylamino)-8-(4-cyano-butyl)-pyrazolo[1,5-a][1,3,5]triazin-4-ylamino]-benzoic acid ethyl ester (8) as a thick oil (0.22 g, 60%).
LCMS(API-ES) m/z: 362.2. 363.0 [M+H+]; 361.0 [M−H+].
Example 8
5-[2-(3-Amino-Phenylamino)-4-Cyclopropylamino-Pyrazolo[1,5-A][1,3,5]Triazin-8-YL]-Pentanoic Acid Methyl Ester (9A)
To a solution of compound (8a) (0.18 g. 0.5 mmol) in 30 mL of MeOH was bubbled through HCl gas at 0° C. for 5 mm. The reaction mixture was sealed and stirred at room temperature for 20 h. A mixture of ester and imine was obtained, which when brought to reflux for 2 h to give the methyl ester exclusively. The mixture was then concentrated and the residue was dissolved in EtOAc, washed with NaHCO3 followed by brine. The organic extract was dried, concentrated and purified by flash chromatography (CH2Cl2/EtOAc 2:1) to provide 5-[2-(3-amino-phenylamino)-4-cyclopropylamino-pyrazolo[1,5-a][1,3,5]triazin-8-yl]-pentanoic acid methyl ester 9a (0.13 g, 65%). LCMS(API-ES) m/z: 395.2. 396.0 [M+H+]; 394.0 [M−H+].
Example 9
5-[2-(3-Amino-Phenylamino)-4-Cyclopropylamino-Pyrazolo[1,5-A][1,3,5]Triazin-8-YI]-Pentanoic Acid (10A)
To a solution compound (9a) (0.12 g, 0.3 mmol) in 10 mL of MeOH and 0.5 mL of H2O was added NaOH (40 mg, 1 mmol). The reaction mixture was refluxed for 1 h, concentrated to re-move MeOH. The reaction solution was adjusted to pH 4 with HCl and the solid was collected by filtration, washed with water, and dried in vacuum over P2O5 to give 5-[2-(3-amino-phenylamino)-4-cyclopropylamino-pyrazolo[1,5-a][1,3,5]triazin-8-yl]-pentanoic acid (10a) (0.1 g, 90%).
LCMS(API-ES) m/z: 381.2, 382.0 [M+H+]; 380.0 [M−H+].
Example 10
(11,14)3,5-N-{Cyclopropyl-Pyrazolo[1,5-A][1,3,5]Triazin-4-YL-Amino}-(2N,4N)-Phenyl-1,5-Diaza-Cyclotetradeca-8-One (11A)
A solution of compound (10a) (0.1 g, 0.25 mmol) and HATU (0.12 g. 0.3 mmol) in 5% DIEA/NMP (1 mL) was stirred at room temperature for 30 min. (11.14)3,5N-{cyclopropyl-pyrazolo[1,5-a][1,3,5]triazin-4-yl-amino}-(2N,4N)-phenyl-1,5-diaza-cyclotetradeca-8-one (11a) was obtained by preparative RP-HPLC (0.05 g, 55%)
LCMS(API-ES) m/z: 363.1, 364.0 [M+H+]; 362.0 [M−H+].
In a manner similar to that recited in Examples 1-10, compounds having the following formulas were synthesized and purified.
Example 11
(11,14)3,5 N-{[{N-Methyl-N-(1-Mehyl-Pyrrolidin-3-YL)-Carbonyl}-Phen-3-YL]-Pyrazolo[1,5-A][1,3,5]Triazin-4-YL-Amino}-(2N,4N)-Phenyl-1,5-Diaza-Ccyclotetradeca-8-One (11G)
1,3-[2-(3-Amino-phenylamino)-8-(4-methoxycarbonyl-butyl)-pyrazolo[1,5-a][1,3,5]triazin-4-ylamino]-benzoic acid methyl ester (9b) was obtained in a similar manner to that recited in Example 8.
LCMS(API-ES) m/z: 489.5. 490.1 [M+H+]; 488.0 [M−H+].
Example 12
3-[2-(3-Amino-Phenylamino)-8-(4-Carboxy-Butyl)-Pyrazolo[1,5-A][1,3,5]Triazin-4-Ylamino]-Benzoic Acid (10 B)
To a solution of compound (9 b) (1.5 g, 3.06 mmol) in 50 mL of MeOH and 5 mL of H2O was added NaOH (400 mg. 10 mmol). The reaction mixture was refluxed for 1 h, and concentrated. Concentrated HCl was added to acidify the solution. The solid was collected by filtration, washed with water, and dried in vacuum over P2O5 to give 1,3-[2-(3-amino-phenylamino)-8-(4-methoxycarbonyl-butyl)-pyrazolo[1,5-a][1,3,5]triazin-4-ylamino]-benzoic acid methyl ester (13a) (1.3 g. 93%).
LCMS(API-ES) m/z: 461.4. 462.0 [M+H+]; 460.1 [M−H+].
Example 13
(11,14)3,5N-{[{N-Methyl-N-(1-Methyl-Pyrrolidin-3-YL)-Carbonyl}-Phen-3-YL]-Pyrazolo[1,5-A][1,3,5]Triazin-4-YL-Amino}-(2N,4N)-Phenyl-1,5-Diaza-Cyclotetradeca-8-One (11 G)
To a mixture of compound (10b) (300 mg, 0.6 mmol), DIEA (0.45 mL) in 60 mL of NMP was added HATU (410 mg, 1.08 mmol). The reaction mixture was sonicated for 5 min, and allowed to stand for 0.5 h at room temperature. Methyl-(1-methyl-pyrrolidin-3-yl)-amine (0.117 mL, 0.9 mmol) was added, followed by additional HATU (228 mg. 0.6 mmol). The reaction mixture was stirred at room temperature for 0.5 h. The crude product was purified by preparative RP-HPLC to yield (11,14)3,5N-{[{N-methyl-N-(1-methylpyrrolidin-3-yl)-carbonyl}-phen-3-yl]-pyrazolo[1,5-a][1,3,5]triazin-4-yl-amino}(2N,4N)-phenyl-1,5-diaza-cyclotetradeca-8-one (11g) (210 mg, 57%). LCMS(API-ES) m/z: 539.6. 540.2 [M+H+]; 538.1 [M−H+].
In a manner similar to that recited in the foregoing examples, compounds having the following formulas were synthesized and purified.
Example 14
(11,14)3,5 N-{[(3-Dimethylamino-Pyrrolidine-1-Carbonyl)-Phen-3-YL]-Pyrazolo[1,5-A]Pyrimidin-2.4-YL-Diamino}-(2N,4N)-Phenyl-1,5-Diaza-Cyclotetradecan-6-One (18A)
Example 15
5-(5,7-Dihydroxy-Pyrazolo[1,5-A]Pyrimidin-3-YL)-Pentanenitrile (12 A)
To a solution of 5-(5-amino-1 H-pyrazol-4-yl)-pentanenitrile (2a) (1 g, 6.09 mmol) in 20 mL of EtOAc was added ethyl 3-chloro-3-oxopropionate (2.34 mL, 18.27 mmol) dropwise with stirring in a ice-water bath, followed by TEA (3.08 mL, 30.45 mmol). The reaction mixture was allowed to stir at room temperature for 2 h. The reaction mixture was diluted with EtOAc, washed by 10% aqueous HCl, saturated NaHCO3 and brine, dried over anhydrous Na2 SO4 and concentrated.
A solution of above residue in MeOH (10 mL) and TEA (2 mL) was refluxed for 2 h, concentrated and dried in vacuum to give 5-(5,7-dihydroxy-pyrazolo[1,5-a]pyrimidin-3-yl)-pentanenitrile (15), which was used without further purification in the next step (1.56 g).
LCMS(API-ES) m/z: 232.2. 233.0 [M+H+]; 231.0 [M−H+].
Example 16
5-(5,7-Dichloro-Pyrazolo[1,5-A]Pyrimidin-3-YL)-Pentanenitrile (13A)
A mixture of compound (12a) (1.56 g. 6.74 mmol) and N,N-dimethylaniline (854 μl, 6.74 mmol) in phosphorus oxychloride (25 mL) was heated to reflux in a sealed tube for 4 h and then concentrated. The residue was dissolved in EtOAc (50 mL) and washed with saturated aq NaHCO3, 10% HCl, and brine and dried over anhydrous Na2 SO4. Removal of the solvent provided 5-(5,7-dichloro-pyrazolo[1,5-a]pyrimidin-3-yl)-pentanenitrile (13a). (1.24 g, 69%). LCMS(API-ES) m/z: 269.1, 269.0. 271.0 [M+H+].
Example 17
3-[5-Chloro-3-(4-Cyano-Bityl)-Pyrazolo[1,5-A]Pyrimidin-7-Ylamino]-Benzoic Acid Ethyl Ester (14A)
To a solution of compound (13a) (1.24 g, 4.62 mmol) in 10 mL of ethanol was added ethyl 3-aminobenzoate (764 mg. 4.62 mmol). The reaction mixture was heated at 50° C. for 2 h and then cooled to room temperature. Solvent was removed and the residue was dissolved in EtOAc (50 mL) and washed with saturated aq NaHCO3, 10% HCl, and brine and dried over anhydrous Na2 SO4. Removal of the solvent provided a residue that was purified by flash column with use of EtOAc/hexane (25% to 50%) to yield 3-[5-chloro-3-(4-cyano-butyl)-pyrazolo[1,5-a]pyrimidin-7-ylamino]-benzoic acid ethyl ester (14a) (1.0 g. 50%).
LCMS(API-ES) m/z: 397.8. 398.0. 400.0 [M+H+]; 395.9. 398.0 [M−H+].
Example 18
3-[5-(3-Amino-Phenylamino)-3-(4-Cyano-Butyl)-Pyrazolo[1,5-A]Pyrimidin-7-Ylamino]-Benzoic Acid Ethyl Ester (15A)
A mixture of compound (14a) (0.63 g. 1.6 mmol) and benzene-1,3-diamine (69 mg, 0.636 mmol) in 2 mL of NMP was heated at 160° C. overnight. The reaction mixture was diluted with EtOAc (50 mL) and washed with saturated aq NaHCO3 and brine and dried over anhydrous Na2 SO4. HPLC purification provided 3-[5-(3-amino-phenylamino)-3-(4-cyano-butyl)-pyrazolo[1,5-a]pyrimidin-7-ylamino]-benzoic acid ethyl ester (15a) (0.37 g. 50%).
LCMS(API-ES) m/z: 469.5, 470.1 [M+H+]; 468.0 [M−H+].
Example 19
3-[5-(3-Amino-Phenylamino)-3-(4-Methoxycarbonyl-Butyl)-Pyrazolo[1,5-A]Pyrimidin-7-Ylamino]-Benzoic Acid Methyl Ester (16A)
Through a solution of compound (15a) (0.24 g. 0.5 mmol) in 5 mL of MeOH was bubbled HCl gas at 0° C. for 5 min. The reaction mixture was sealed and stirred at room temperature for 1 h, concentrated, and the residue dissolved in EtOAc, washed with NaHCO3, brine and water. Organic extract was dried, concentrated to provide 3-[5-(3-amino-phenylamino)-3-(4-methoxycarbonyl-butyl)-pyrazolo[1,5-a]pyrimidin-7-ylamino]-benzoic acid methyl ester (16a) (102.1 mg).
LCMS(API-ES) m/z: 488.5, 489.1 [M+H+]; 487.0 [M−H+].
Example 20
3-[5-(3-Amino-Phenylamino)-3-(4-Carboxy-Butyl)-Pyrazolo[1,5-A]Pyrimidin-7-Ylamino]-Benzoic Acid (17A)
To a solution of compound (16a) (102.1 mg, 0.203 mmol) in 5 mL of MeOH was added 1 M NaOH (0.41 mL, 0.407 mmol). The reaction mixture was refluxed for 1 h, and concentrated. HPLC purification gave 3-[5-(3-amino-phenylamino)-3-(4-carboxy-butyl)-pyrazolo[1,5-a]pyrimidin-7-ylamino]-benzoic acid (17a) (50 mg).
LCMS(API-ES) m/z: 460.5. 461.1 [M+H+]; 459.0 [M−H+].
Example 21
(11,14)3,5N-{[(3-Dimethylamino-Pyrrolidine-1-Carbonyl)-Phen-3-YL]-Pyrazolo[1,5-A]Pyrimidin-2,4-YL-Diamino}-(2N,4N)-Phenyl-1,5-Diaza-Cyclotetradecan-6-One (18A)
To a mixture of compound (17 a) (35 mg, 0.075 mmol), DIEA (50 μL) in 1 mL of NMP was added HATU (50 mg, 0.12 mmol). The reaction mixture was sonicated for 2 min, and allowed to stand for 0.5 h at room temperature After which, dimethyl-pyrrolidin-3-yl-amine (15 μL. 0.1 mmol) was added, followed by additional HATU (5 mg. 0.12 mmol). The reaction mixture was stirred at room temperature for 0.5 h. Preparative RP-HPLC purification provided (11,14)3,5N-{[(3-dimethylamino-pyrrolidine-1-carbonyl)-phen-3-yl]pyrazolo[1,5-a]pyrimidin-2,4-yl-diamino}-(2N,4N)-phenyl-1,5-diaza-cyclotetradecan-6-one (18a) (15 mg).
LCMS(API-ES) m/z: 538.6, 539.2 [M+H+]; 537.0 [M−H+].
In a similar manner, the following compound.
was synthesized and purified.
Example 22
CK2 Protein Kinase Inhibition Assay
CK2 protein kinase activity was measured through use of a spectrophotometric PK/LDH coupled assay to detect ATP turnover. Full Length His-tagged Human CK2 was cloned, expressed, and purified from an E. coli expression system. The peptide substrate for CK2 phosphorylation was RRRDDDSDDD (Genscript Corporation, Piscataway, N.J., USA). A typical CK2 enzymatic assay contained ˜20 nM human CK2, 100 μM peptide substrate, 50 mM Tris-HCl pH 8.0, 100 mM NaCl, 10 mM MgCl2, 200 μM EDTA, 5 mM 2-mercaptoethanol, 1 mM phosphoenol pyruvate, 150 μM NADH, 0.5% PK/LDH Mix (Sigma #P-0294), 2.5% DMSO and 50 μM ATP. Inhibitor compounds were suspended in 100% DMSO and added to achieve various concentrations at a constant DMSO proportion of 2.5% by volume. Prior to the addition of ATP to initiate the phosphorylation reaction, CK2 enzyme was pre-incubated with inhibitors and other assay components for 5 min. Progress of the reaction was continuously monitored by the change in UV/Vis absorbance at 340 nm. Reaction rates were plotted versus inhibitor concentration and Ki values were fitted with the assumption of competitive inhibition and use of a Km value of 10 μM. In the case of very potent binding, tight-binding methods were employed to determine Ki. The results are recorded in Tables 1 and 2.
Example 23
Inhibition of Cell Growth
HCT-116 and PC-3 cells were cultured at 37° C. with 5% CO2 and in 10% fetal bovine serum with McCoy's 5A modified medium and F-12 K medium respectively. Cells were plated on 96 well plates at a density of 2,000-4,000/well in the volume of 100 μL medium. After overnight incubation, 50 μL more medium containing various amount of CK2 inhibitors were added into each well to give final inhibitor concentrations ranging from 0.01 to 20 μM in 1% dimethylsulfoxide. The control wells contained 1% dimethylsulfoxide only in their medium. After further incubation of three to five days to allow cells grow before the control cells reach confluence, 15 μL/well MTT reagent (5 mg/mL) were added and incubated for 4 h. After the incubation, the medium was removed and the newly generated formazan solubilized with dimethylsulfoxide (100 μL/well) and measured at 540 nm. The absorption data were fit into equation and calculated for IC50 values through use of the program KaleidaGraph (Synergy Software). The fitting equation for IC50 is y=a+b/(1+(x/IC50)); x is the compound concentration, a is the background absorption at 540 nM, and b is the absorption at zero compound concentration. The results are recorded in Tables 1 and 2.
TABLE 1
Triazine-based compounds.
(11)
IC 50
HCT
116
IC 50
Com-
K i
cells
PC-3
pound
Name
(μM)
(μM)
(μM)
11a
(11,14)3,5N-{cyclopropyl-
<0.1
<1
<1
pyrazolo[1,5-a][1,3,5]triazin-4-yl
amino}-(2N,4N)-phenyl-1,5-diaza-
cyclotetradeca-8-one
11b
(11,14)3,5N-{iso-propyl-pyrazolo[1,5-
a][1,3.5]triazin-4-yl-amino}-(2N,4N)-
phenyl-1,5-diaza-cyclotetradeca-8-one
11c
(11,14)3,5N-{n-propyl-pyrazolo[1.5-
a][1,3,5]triazin-4-yl-amino}-(2N,4N)-
phenyl-1,5-diaza-cyclotetradeca-8-one
11d
(11,14)3,5N-{pyrid-3-yl-pyrazolo[1,5-
<0.1
<1
<1
a][1,3,5]triazin-4-yl-amino}-(2N,4N)-
phenyl-1,5-diaza-cyclotetradeca-8-one
11e
(11,14)3,5N-{(3-ethoxyphenyl)-
<0.1
<1
<1
pyrazolo[1,5-a][1,3,5]triazin-4-yl-
amino}-(2N,4N)-phenyl-1,5-diaza-
cyclotetradeca-8-one
11f
(11,14)3,5N-{(3-
ethoxycarbonylphenyl)-pyrazolo[1,5-
a][1,3,5]triazin-4-yl-amino}-(2N,4N)-
phenyl-1,5-diaza-cyclotetradeca-8-one
11g
(11,14)3,5N-{3-(3-{[methyl(1-
<0.1
<1
<1
methylpyrrolidin-3-
yl)amino]carbonyl}phenyl)-
pyrazolo[1,5-a][1,3,5]triazin-4-yl-
amino}-(2N,4N)-phenyl-1,5-diaza-
cyclotetradeca-8-one
11h
(11,14)3,5N-{3-(4-methylpiperazin-1-
<0.1
<1
<1
ylcarbonyl)phenyl-pyrazolo[1,5-
a][1,3,5]triazin-4-yl-amino}-(2N,4N)-
phenyl-1,5-diaza-cyclotetradeca-8-one
11i
(11,14)3,5N-{[3-
<0.1
<1
<1
(dimethylamino)pyrrolidin-1-
yl]carbonyl}phenyl-pyrazolo[1,5-
a][1,3,5]triazin-4-yl-amino}-(2N,4N)-
phenyl-1,5-diaza-cyclotetradeca-8-one
11j
(11,14)3,5N-{4-[(3-{3-
<0.1
<1
<1
(diethylamino)carbonyl}phenyl)amino]-
pyrazolo[1,5-a][1,3,5]triazin-4-yl-
amino}-(2N,4N)-phenyl-1,5-diaza-
cyclotetradeca-8-one
11k
(11,14)3,5N-{4-{[3-({[2-
<0.1
<1
<1
(dimethylamino)ethyl]-
amino}carbonyl)phenyl]amino}-
pyrazolo[1,5-a][1,3,5]triazin-4-yl-
amino}-(2N,4N)-phenyl-1,5-diaza-
cyclotetradeca-8-one
11l
(11,14)3,5N-{4-({3-[(3-
<0.1
<1
<1
hydroxyazetidin-1-
yl)carbonyl]phenyl}amino)-
pyrazolo[1,5-a][1,3,5]triazin-4-yl-
amino}-(2N,4N)-phenyl-1,5-diaza-
cyclotetradeca-8-one
11m
(11,14)3,5N-{[(1-methylazetidin-3-
<0.1
<1
<1
yl)amino]carbonyl}phenyl)amino]-
pyrazolo[1,5-a][1,3,5]triazin-4-yl-
amino}-(2N,4N)-phenyl-1,5-diaza-
cyclotetradeca-8-one
11n
(11,14)3,5N-{4-[(3-{[[2-
<0.1
<1
<1
(dimethylamino)ethyl](methyl)-
amino]carbonyl}phenyl)amino]-
pyrazolo[1,5-a][1,3,5]triazin-4-yl-
amino}-(2N,4N)-phenyl-1,5-diaza-
cyclotetradeca-8-one
11o
(11,14)3,5N-{4-[(3-{[methyl(1-
<0.1
<1
methylpiperidin-4-yl)amino]carbonyl}-
phenyl)amino]-pyrazolo[1,5-
a][1,3,5]triazin-4-yl-amino}-(2N,4N)-
phenyl-1,5-diaza-cyclotetradeca-8-one
11p
(11,14)3,5N-{[(3-{[3-
<0.1
<1
<1
(diethylamino)pyrrolidin-1-
yl]carbonyl}phenyl)amino]-
pyrazolo[1,5-a][1,3,5]triazin-4-yl-
amino}-(2N,4N)-phenyl-1,5-diaza-
cyclotetradeca-8-one
11q
(11,14)3,5N-{[(3-{[3-
<0.1
<1
<1
(diethylamino)azetidin-1-yl]carbonyl}-
phenyl)amino]-pyrazolo[1,5-
a][1,3,5]triazin-4-yl-amino}-(2N,4N)-
phenyl-1,5-diaza-cyclotetradeca-8-one
11r
(11,14)3,5N-{{[3-(piperazin-1-
<0.1
<1
ylcarbonyl)phenyl]amino}-
pyrazolo[1,5-a][1,3,5]triazin-4-yl-
amino}-(2N,4N)-phenyl-1,5-diaza-
cyclotetradeca-8-one
11s
(11,14)3,5N-{4-[(3-{[2-
<0.1
<1
(diethylamino)ethyl](methyl)amino]-
carbonyl}phenyl)amino]-pyrazolo[1,5-
a][1,3,5]triazin-4-yl-amino}-(2N,4N)-
phenyl-1,5-diaza-cyclotetradeca-8-one
TABLE 2
Pyrimidine-based compounds
(18)
IC 50
HCT
116
IC 50
Com-
K i
cells
PC-3
pound
Name
(μM)
(μM)
(μM)
18a
(11,14)3,5N-{[(3-Dimethylamino-
<0.1
<3
<3
pyrrolidine-1-carbonyl)-phen-3-yl]-
pyrazolo[1,5-a]pyrimidin-2,4-yl-
diamino}-(2N,4N)-phenyl-1,5-
diaza-cyclotetradecan-6-one
18b
(11,14)3,5N-{[(3-cyclopropyl]-
<0.1
<3
<3
pyrazolo[1,5-a]pyrimidin-2,4-yl-
diamino}-(2N,4N)-phenyl-1,5-
diaza-cyclotetradecan-6-one
The examples above exemplify compounds of Formula (I) and assays that may readily be per-formed to determine their activity levels against CK2 protein kinase. It will be apparent that such assays to other suitable assays known in the art may be used to select an inhibitor having a desired level of activity against a selected target.
While the invention has been illustrated by reference to specific and preferred embodiments, those skilled in the art will recognize that variations and modifications may be made through routine experimentation and practice of the inventions.
|
Pyrimidine- and triazine-based chemical compounds that are useful, for example, as protein kinase inhibitors for treating cancer, neurological disorders, autoimmune disorders, and other diseases, and methods of using such compounds.
| 2
|
TECHNICAL FIELD
The present invention has to do with dental impression materials, namely reversible hydrocolloid gel compositions having improved strength and working properties by virtue of the use of dipropylene glycol in the compositions in lieu of a portion of the water normally used to form the gels.
BACKGROUND OF THE INVENTION
In dental practice the professional uses impression materials to obtain impressions of teeth which are then used to mold bridges, crowns and inlays, or other prosthesis. Precision of impression molds is a paramount consideration for comfort and success of the prosthesis. Realizing precision of impression is dependent on obtaining a good impression in the first place, and this requires workability in the impression material used, and maintaining the good impression and this requires high gel strength and tensile strength in the gelled impression composition during removal from the teeth and through use in the forming the plaster from which the prosthesis is to be made.
Many dentists prefer the use of reversible hydrocolloid gels as impression compositions which are unparalleled for accuracy. These gels are obtained by mixing water and a gel base such as agar-agar, and tempering the gel in a conditioning bath until used.
The following patents relate to reversible hydrocolloid gel impression materials, and have been considered in preparing this application: U.S. Pat. No. 2,021,059 to Harrison; U.S. Pat. No. 2,089,552 to Harrison; and, U.S. Pat. No. 2,234,583 to Preble. The first two of these patents teach the use of glycerol in hydrocolloid compositions, but such systems require a higher temperature tempering bath to avoid loss of workability, and thus a pre-application conditioning step, while the last of these patents teaches that an increase in strength of reversible hydrocolloid gel materials is realized by the use of borates, but such systems are lumpy, too viscous for ready workability, usability under patient tolerable temperature conditions, and may well lack good stone set.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an improved dental impression composition. It is another object to provide a dental impression material which is improved in gel strength and tensile strength, is less volatile so as to have reduced evaporation, and which has improved workability for easier and more accurate impression taking. It is yet another object to provide a dental impression material which may be maintained in a tempering bath at less than 150° F., e.g about 130° F. rather than the usual 150° F. while maintaining superior workability, for direct application to the patient without an extra cooling step.
These and other objects of the invention to become apparent hereinafter are realized in accordance with the invention in the low temperature tempering, high gel strength, high tensile strength dental impression composition consisting essentially of a reversible hydrocolloid gel forming base and an aqueous reagent in an amount sufficient to form a reversible gel with the base, the reagent comprising from 50 to 95% by weight water and the balance dipropylene glycol.
In particular embodiments, the gel forming base is agar-agar; the composition is free of glycerine; the weight ratio of aqueous reagent to gel forming base is between 8 and 12; and there may be included also an acid buffering compound in effective amount, e.g. a borate radical donor compound in acid buffering amount in the composition, such as an alkaline earth metal borate, particularly zinc borate.
In a preferred embodiment of the invention, there is provided a low temperature tempering, high gel strength, high tensile strength dental impression composition consisting essentially of a reversible hydrocolloid gel forming base and an aqueous reagent in an amount equal to the amount of water sufficient to form a reversible gel with the base, the reagent comprising water in relatively reduced amount to increase the gel strength and the tensile strength of the gel and the balance dipropylene glycol in an amount maintaining workability in the impression material with the reduced amount of water.
In this as in other embodiments of the invention preferably the weight ratio of dipropylene glycol to gel base in the composition is between 1.5 and 5.0; the gel forming base is agar-agar; the composition is free of glycerine; the weight ratio of aqueous reagent to gel forming base is between 8 and 12; there is also present an acid buffering compound in effective amount; the acid buffering compound is a borate radical donor compound present in acid buffering amount in the composition; the borate radical donor compound is an alkaline earth metal borate; the alkaline earth metal borate compound is zinc borate; and the zinc borate is present in an amount of 5 to 20% by weight based on the weight of the gel base.
In a highly particularly preferred embodiment of the invention there is provided a low temperature tempering, high gel strength dental impression composition consisting essentially of from 8 to 12 parts agar-agar, from 60 to 80 parts water, from 15 to 30 parts dipropylene glycol, and from 0.3 to 2.5 parts of borate radical donor compound, per 100 parts by weight, wherein the borate radical donor compound is zinc borate.
The invention further contemplates the method of increasing the gel strength and tensile strength of reversible hydrocolloid compositions comprising a reversible hydrocolloid forming base and a predetermined weight amount of water sufficient to form a gel with the base, including omitting from 10 to 35% of the predetermined amount of water and adding to the composition an amount of dipropylene glycol equal to from 50 to 150% of the water weight amount omitted.
DETAILED DESCRIPTION
As noted above, the present composition includes a reversible hydrocolloid gel forming base and an aqueous reagent. The base is typically agar-agar, but may be any of the gel forming materials known in the art including Irish moss, Iceland moss, etc. The aqueous reagent comprises water and the dipropylene glycol. The reagent typically comprises from 50 to 95% by weight water and the balance dipropylene glycol, with preferred proportions being 65 to 75 weight percent water and conversely 35 to 25 weight percent of the glycol. The aqueous reagent is preferably free or substantially free (less than 5% by weight) of glycerine which has been found to disadvantageous in formulating a composition which is temperable at the lower range of less than 150° F. and preferably about 130 ° F. rather than the typical 150° F.
The aqueous reagent is typically present in an amount of 8 to 12 parts by weight per part of gel forming base, and preferably about 10 parts per part of base, with the weight ratio of dipropylene glycol to gel base in the composition being in the 1.5 to 5 range and preferably about 2.5 to 3.5.
The use of a buffering compound improves the gel life, and for this purpose borate radical compounds have been found highly useful, particularly the alkaline earth borates such as and especially zinc borate in amounts of 5 to 20% by weight based on the weight of the gel base.
The combination of zinc borate and dipropylene glycol with agar-agar gel forming base in the just discussed proportions has been found to provide a uniquely advantageous hydrocolloid dental impression material with nearly ideal properties of gel strength (improved about 30% over glycerine formulas), tensile strength (improved about 30% over glycerine formulas) tempering ability (130° F. vs. 150° F. for glycerine formulas), reduced rate of evaporation, dramatically better texture and workability than glycerine formulas at the cooler temper, and accuracy of impression particularly at undercuts is heightened.
EXAMPLE
A typical composition according to the invention is prepared by placing the following materials in a suitable heated vessel: 140 parts by weight of agar-agar melted in 1050 parts of boiling water; a thickener at 10 parts and dissolved into the agar-agar water mixture; zinc borate at 15 parts predissolved in a minimum amount of water; and 350 parts of dipropylene glycol with flavoring and colorant if desired and the entire mass blended until uniform and then the mixture is put up in small tubes for use by the dentist.
It is noted that the composition contains less than the usual amount of water by about 10 to 35%. This reduced amount of water translates to greater gel strength and greater tensile strength in the set composition. The reduced amount of water makes the composition relatively more viscous, which is useful in obtaining impressions on undercuts and vertical surfaces. Nonetheless the composition exhibits smooth workability, the viscosity is in the nature of thixotropy, and under spatulation, syringing or like forming techniques, the viscosity is a benefit and not a drawback, where the omitted water is replaced by from 50 to 150% of the water weight amount of the dipropylene glycol.
|
A dental impression composition is provided which has relatively lower water content for higher tensile and gel strengths, and an effective amount of dipopylene gylcol to offset the reduced amount of water and provide workability in the composition at storage tempering temperatures of as little as 130° F.
| 8
|
BACKGROUND OF THE INVENTION
While there are a number of commercially available mild to moderate analgesic agents, the search for alternative analgesic agents has continued because of the problems attendant with current therapy.
Aspirin and related salicylates are considered to be non-narcotic analgesic agents useful for relieving mild to moderate pain, in addition to their anti-inflammatory and anti-pyretic properties. However, the ingestion of salicylic acid or related salycilates may result in epigastric distress, nausea and vomiting. This widely used class of non-narcotic analgesic agents may also cause gastric ulceration and even hemorrhage both in experimental animals and man. Exacerbation of peptic ulcer symptoms and erosive gastritis have all been reported in patients on high dose therapy, i.e., arthritis patients. Aspirin is also one of the most common causes of drug poisoning in young children and has a potential of serious toxicity if used improperly.
Acetominophen is also considered to be a non-narcotic analgesic agent useful in treating pain associated with simple headache, common muscular aches, etc. While acetominophin is particularly useful for patients who cannot take aspirin, i.e. ulcer patients, its use in contraindicated in individuals who have exhibited a sensitivity to it.
In addition to their drawbacks in view of their potential side effects, the mild, non-narcotic analgesic agents are not sufficiently potent to relieve the severe pain associated with surgery, cancer and the like.
Unfortunately, the potent analgesic agents capable of relieving such severe pain are also narcotic agents and their use entails the risk of producing physical or psychological dependence.
One moderate analgesic agent which has enjoyed great commercial success for a number of years, α-d-propoxyphene hydrochloride (Darvon®, Eli Lilly and Co., Indianapolis, Ind.) has been widely used to relieve pain associated with dental extractions, afterbirth pain, and some post-operative pain. This widely used analgesic agent has been reported to be ineffective in relieving many types of pain, and recently, reports of serious side effects and deaths have created a need for alternative, moderate analgesic agents. The present invention provides such agents.
SUMMARY OF THE INVENTION
The analgesic agents of the present invention are novel 1-cycloalkyl phosphonium salts represented by the formula: ##STR4## wherein: R is selected from the group consisting of lower alkyl, hydroxy lower alkyl, halo lower alkyl, amino lower alkyl, cyano lower alkyl, lower alkenyl with the limitation that the double bond is not on the carbon atom attached to the oxygen atom, benzyl, substituted benzyl and ##STR5## wherein q is 0 or 1 and R 4 is selected from the group consisting of hydroxy, loweralkoxy, phenyl, substituted phenyl, and ##STR6## wherein R 5 and R 6 are the same or different members of the group consisting of hydrogen and loweralkyl or taken together form a 5 or 6 membered ring; m is 1,2 or 3; n is 0 or 1; o is 0 or 1; p is 0 or 1; R 1 , R 2 and R 3 are the same or different members of the group consisting of hydrogen, lower alkyl, lower alkoxy and halo; and X is a pharmaceutically acceptable anion.
The compounds of this invention are useful as analgesic agents when administered to mammalian patients suffering from mild to moderate pain in oral or patenteral dosages of from about 0.2 to 20 mg/kg of body weight and preferably from about 1 to 10 mg/kg of body weight. Generally the compounds are administered every three to six hours unless formulated in sustained release form, in which case they may be administered every 6 to 12 hours until the pain has diminished.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The term "lower alkyl", as used herein, refers to straight and branched chain alkyl radicals having from 1 to 6 carbon atoms such as methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, tert-butyl, n-pentyl, 2-methyl-butyl, 2,2-dimethyl-propyl, n-hexyl, etc.
The terms "hydroxy lower alkyl", "halo lower alkyl", "amino lower alkyl", and "cyano lower alkyl" refer to substituted C 2 -C 6 straight or branched chain alkyl radicals such as hydroxyethyl, 3-cyano-n-pentyl, 2-chloro-n-propyl; trifluoromethyl, etc., i.e., mono, di- or tri-substituted lower alkyl radicals.
The term "lower alkenyl" refers to C 2 -C 6 straight or branched chain alkenyl radicals and are limited to those having a double bond in a position other than on the carbon adjacent the oxygen.
The term "substituted benzyl" refers to a mono, di- or tri-substituted benzyl radical, substituted by lower alkyl, lower alkoxy, halo, nitro, cyano, halo lower alkyl, hydroxy, alkylcarbonyl, etc.
The term "lower alkoxy" refers to straight or branched chain C 1 -C 6 alkoxy groups, i.e., methoxy, ethoxy, iso-propoxy, etc.
The term "anions" includes, but is not limited to pharmaceutically acceptable (non-toxic) anions such as chloride, bromide, iodide, fluoride, acetate, propionate, sulfate, bisulfate, acetate, oxalate, valerate, oleate, laurate, borate, citrate, maleate, fumarate, lactate, succinate, tartrate, benzoate, tetrafluoroborate, trifluoromethylsulfonate, napsylate, tosylate, etc.
The term "pharmaceutically acceptable salts" refers to the hydrochlorides, hydrobromides, acetates etc. as well as the inner salts.
The analgesic activity of the compounds of the present invention was initially established in the mouse writhing test.
The Wittig reagents used as starting materials to prepare the compounds of this invention can be prepared by the 5 step process of House, H. O. et al., J. Org. Chem. 28, 90(1963) from the appropriate lactone, or, in the case of the α-ketocyclohexyl starting materials, from the improved process of one aspect of the present invention.
Alkylation or acylation of these activated ylides on oxygen is aided by steric hinderance, the choice of non-protic solvents (although alkylation is possible in protic solvents) and the fact that an ylide is an internally charge compensated anion, therefore association with external cations is precluded. The use of non-polar, aprotic solvents also facilitate product isolation due to the polarity of the products.
Generally, the starting ylides are sufficiently reactive that reaction usually occurs conveniently at room temperature although higher or lower temperatures can be used if desired.
The process aspect of this invention allows the synthesis of α-ketocyclohexylidene triphenyl phosphorane in one step from the compounds of commonly assigned U.S. Pat. No. 4,075,407 or a total of three steps from a lactone disclosed in commonly assigned, copending U.S. Ser. No. 172,781, filed July 28, 1980, thus affording a considerable savings over prior art processes.
The following examples further illustrate the present invention.
EXAMPLE 1
Preparation of [2-(phenylmethoxy)-1-cyclohexen-1-yl]triphenylphosphonium bromide
Three grams of α-ketocyclohexylidenetriphenylphosphorane [J. Org. Chem., 28, pp 90-92(1963)] is suspended in 50 ml of acetone and 1.0 ml of benzyl bromide (1.1 eq) is added. The reaction mixture is stirred at room temperature under argon for one day, heated at reflux for one day, then filtered. The filtrate is washed twice with acetone and dried at 60° C./0.5 mm pressure for one day to provide 3.48 g of the desired product, m.p. 206°-208° C. and having the formula: ##STR7##
EXAMPLE 2
Preparation of [2-(1-methylethoxy)-1-cyclohexen-1-yl]triphenylphosphonium iodide
Two grams of α-ketocyclohexylidenetriphenylphosphorane is suspended in about 50 ml of acetone and 20 ml of chloroform and heated at reflux under argon for one day. The solution is cooled to room temperature, the solvents removed with a rotary evaporator and the resulting product triturated with acetone, filtered and dried overnight at 60° C./0.5 mm pressure to yield 1.2 g of product, m.p. 216°-219° C. and having the formula: ##STR8##
EXAMPLE 3
Preparation of (2-methoxy-1-cyclohexen-1-yl)triphenylphosphonium, 4-methylbenzenesulfonate
α-Ketocyclohexylidenetriphenylphosphorane (1.3 g) is suspended in about 50 ml of xylene and 1.1 mg of methyl tosylate is added thereto, all under argon. The reaction mixture is refluxed under argon for about 1 day, cooled to room temperature, the xylene decanted and the resulting oil washed twice with toluene. The oil is crystallized and recrystallized from ether/acetone to yield the desired product having the following analyses and formula:
Analysis Calcd. for C 32 H 33 O 4 PS: C, 70.57; H, 6.11; P, 5.69. Found: C, 70.26; H, 6.17; P, 5.65. ##STR9##
EXAMPLE 4
Preparation of [2-(3-methyl-2-butenyloxy)-1-cyclohexen-1-yl]triphenylphosphonium bromide
α-Ketocyclohexylidenetriphenylphosphorane (2.0 g) is suspended in 50 ml of acetone and 830 mg of 1-bromo-3-methyl-2-butene is added thereto, all under a nitrogen atmosphere. The reaction mixture is stirred at room temperature for about 10 days and filtered. The crystals are washed with acetone three times, and dried at 55° C./0.5 mm pressure for about two hours to yield the desired product having the formula: ##STR10##
Analysis Calcd. for C 29 H 32 BrOP: C, 68.64; H, 6.36; P, 6.10. Found: C, 68.30; H, 6.42; P, 5.84.
EXAMPLE 5
Preparation of [2-(2-oxo-2-phenylethoxy)-1-cyclohexen-1-yl]triphenylphosphonium bromide
α-Ketocyclohexylidenetriphenylphosphorane (2.0 g) and phenacyl bromide are reacted following the method of Example 4 to provide 2.1 g of the desired product, m.p. 182.5°-185° C., having the formula ##STR11##
EXAMPLE 6
Preparation of [2-(((2-carboxyphenyl)-carbonyl)oxy)-1-cyclohexen-1-yl]triphenylphosphonium hydroxide, inner salt
α-Ketocyclohexylidenetriphenylphosphorane (2.0 g) is dissolved/suspended in 50 ml of acetone and 850 mg of phthalic anhydride is added thereto, all under a nitrogen atmosphere. The reaction mixture is stirred at room temperature for 4 days, after which the solvent is removed under a nitrogen stream and the resulting oil crystallized from acetone to give 1.7 g of the inner salt having the formula ##STR12##
Analysis Calc. for C 32 H 29 O 5 P: C, 73.27; H, 5.53; P, 5.91. Found: C, 73.01; H, 5.53; P, 5.99.
The inner salt can be conveniently converted, if desired, to a pharmaceutically acceptable anionic salt, by treatment with acid.
EXAMPLE 7
Preparation of [2-(2-methoxy-2-oxoethoxy)-1-cyclohexen-1-yl]triphenylphosphonium bromide
α-Ketocyclohexylidenetriphenylphosphorane (2.0 g) and 0.5 ml of methylbromoacetate are reacted following the method of Example 4 to provide the desired product having the formula ##STR13##
Analysis Calcd. for C 27 H 28 BrO 3 P O.25H 2 O: C, 62.85; H, 5.57; P, 6.01. Found: C, 62.81; H, 5.45; P, 5.94
EXAMPLE 8
Preparation of [2-(phenylmethoxy)-1-cyclopenten)1-yl]triphenylphosphonium bromide
[2-(Phenylmethoxy)-1-cyclopenten-1-yl]triphenylphosphonium bromide is prepared by the method of Example 1 from α-ketocyclopentylidenetriphenylphosphorane. ##STR14##
EXAMPLE 9
Preparation of [2-(phenylmethoxy)-1-cyclohepten-1-yl]triphenylphosphonium bromide
[2-(Phenylmethoxy)-1-cyclohepten-1-yl]triphenylphosphonium bromide is prepared by the method of Example 1 from α-ketocycloheptylidenetriphenylphosphorane. ##STR15##
EXAMPLE 10
Preparation of [2-(1-methylethoxy)-1-cyclopenten-1-yl]triphenylphosphonium iodide
[2-(1-methylethoxy)-1-cyclopenten-1-yl]triphenylphosphonium iodide is prepared by the method of Example 2 from α-ketocyclopentylidenetriphenylphosphorane. ##STR16##
EXAMPLE 11
Preparation of [2-(1-methylethoxy)-1-cyclohepten-1-yl]triphenylphosphonium iodide
[2-(1-Methylethoxy)-1-cyclohepten-1-yl]triphenylphosphonium iodide is prepared by the method of Example 2 from α-ketocycloheptylidenetriphenylphosphorane. ##STR17##
EXAMPLE 12
Preparation of (2-methoxy-1-cyclopenten-1-yl)triphenylphosphonium 4-methylbenzenesulfonate
2-Methoxy-1-cyclopenten-1-yl)triphenylphosphonium 4-methylbenzenesulfonate is prepared by the method of Example 3 from α-ketocyclopentylidenetriphenylphosphorane. ##STR18##
EXAMPLE 13
Preparation of (2-methoxy-1-cyclohepten-1-yl)diphenyl-2-o-methylphenylphosphonium 4-methylbenzensulfonate
2-Methoxy-1-cyclohepten-1-yl)diphenyl-2-o-methylphenyltriphosphonium 4-methylbenzenesulfonate is prepared by the method of Example 3 from α-ketocycloheptylidenediphenyl-2-o-methylphenylphosphorane. ##STR19##
EXAMPLE 14
Preparation of [2-(3-methyl-2-butenyloxy)-1-cyclopenten-1-yl]triphenylphosphonium bromide
[2-(3-Methyl-2-butenyloxy)-1-cyclo-penten-1-yl]triphenylphosphonium bromide is prepared by the method of Example 4 from α-ketocyclopentylidenetriphenylphosphorane. ##STR20##
EXAMPLE 15
Preparation of [2-(3-methyl-2-butenyloxy)-1-cyclohepten-1-yl]triphenylphosphonium bromide
[2-(3-Methyl-2-butenyloxy)-1-cyclohepten-1-yl]triphenylphosphonium bromide is prepared by the method of Example 4 from α-ketocycloheptylidenetriphenylphosphorane. ##STR21##
EXAMPLE 16
Preparation of [2-(2-oxo-phenylethoxy)-1-cyclopenten-1-yl]triphenylphosphonium bromide
[2-(2-oxo-phenylethoxy)-1-cyclopenten-1-yl]triphenylphosphonium bromide is prepared by the method of Example 5 from α-ketocyclopentylidenetriphenylphosphorane. ##STR22##
EXAMPLE 17
Preparation of [2-(2-oxo-phenylethoxy)-1-cyclohepten-1-yl]triphenylphosphonium bromide
[2-(2-Oxo-phenylethoxy)-1-cyclohepten-1-yl]triphenylphosphonium bromide is prepared by the method of Example 5 from α-ketocycloheptylidenetriphenylphosphorane. ##STR23##
EXAMPLE 18
Preparation of [2-(((2-carboxyphenyl)carbonyl)oxy)-1-cyclopenten-1-yl]triphenylphosphonium hydroxide, inner salt, is prepared by the method of Example 6 from α-ketocyclopentylidenetriphenylphosphorane. ##STR24##
EXAMPLE 19
Preparation of [2-(((2-carboxyphenyl)carbonyl)oxy)-1-cyclohepten-1-yl]triphenylphosphonium hydroxide, inner salt
[2-(((2-Carboxyphenyl)carbonyl)oxy]-1-cyclohepten-1-yl]triphenylphosphonium hydroxide, inner salt is prepared by the method of Example 6 from α-ketocycloheptylidenetriphenylphosphorane. ##STR25##
EXAMPLE 20
Preparation of [2-(2-methoxy-2-oxoethoxy)-1-cyclopenten-1-yl]triphenylphosphonium bromide
[2-(2-Methoxy-2-oxoethoxy)-1-cyclopenten-1-yl]triphenylphosphonium bromide is prepared by the method of Example 7 from α-ketocyclopentylidenetriphenylphosphorane. ##STR26##
EXAMPLE 21
Preparation of [2-(2-methoxy-2-oxoethoxy)-1-cyclohepten-1-yl]triphenylphosphonium bromide
[2-(2-Methoxy-2-oxoethoxy)-1-cyclohepten-1-yl]triphenylphosphonium bromide is prepared by the method of Example 7 from α-ketocycloheptylidenetriphenylphosphorane. ##STR27##
It will be apparent to those skilled in the art that by starting with the appropriately substituted α-ketocycloalkylidenetriphenyl or benzyl or substituted phenyl or benzylphosphorane, the desired product is obtained, i.e. ##STR28## wherein R, R 1 , R 2 , R 3 , m, n, o and p are as defined above.
The following examples illustrate the improved process of the present invention.
EXAMPLE 22
Preparation of α-ketocyclohexylidenetriphenylphosphonium bromide
[(Tetrahydro-2H-pyran-2-ylidene)methyl]triphenylphosphonium chloride (U.S. Pat. No. 4,075,407) was suspended in xylene under argon and refluxed with vigorous stirring for 6 days. The reaction mixture was cooled to room temperature, filtered, stirred with acetone for two hours, filtered and dried overnight at 50° C. to give 30 g of product, m.p. 236°-240° C. ##STR29##
EXAMPLE 23
Conversion of α-ketocyclohexylidenetriphenylphosphonium bromide to α-ketocyclohexylidenetriphenylphosphorane
8.5 g of the product of Example 2, was dissolved in about 50 ml of methanol and 450 ml of H 2 O was added. Solid potassium carbonate (excess) was added and the crystals filtered, washed with water and dried overnight at 110° C./0.5 mm pressure to give 6.88 g of product. ##STR30##
While the phosphorane of Example 23 can be prepared in a single step by adding base to Example 22, it is advantageous to add any suitable base such as triethylamine, sodium hydroxide, etc., after the salt has formed. The conversion thereafter is instantaneous.
The process of Example 22 requires temperatures in excess of 110° C., i.e. from 110° C.-180° C., preferably from about 135° C.-150° C. and most preferably at about 140° C. for from about 24-84 hours.
Pharmaceutical compositions comprising a therapeutically effective amount of a compound of the present invention and a pharmaceutically acceptable carrier or diluent are also provided by the present invention.
Solid dosage forms for oral administration include capsules, tablets, pills, powders and granules. In such solid dosage forms, the active compound is admixed with at least one inert diluent such as sucrose, lactose, or starch. Such dosage forms can also comprise, as is normal practice, additional substances other than inert diluents, e.g., lubricating agents such as magnesium stearate. In the case of capsules, tablets and pills, the dosage forms may also comprise buffering agents. Tablets and pills can additionally be prepared with enteric coatings.
Liquid dosage forms for oral administration include pharmaceutically acceptable emulsions, solutions, suspensions, syrups, and elixirs containing inert diluents commonly used in the art, such as water. Besides, inert diluents, such compositions can also include adjuvants, such as wetting agents, emulsifying and suspending agents, and sweetening, flavoring, and perfuming agents.
Preparations according to this invention for parenteral administration include sterile aqueous or non-aqueous solutions, suspensions, or emulsions. Examples of non-aqueous solvents or vehicles are propylene glycol, polyethylene glycol, vegetable oils, such as olive oil, and injectable organic esters such as ethyl oleate. Such dosage forms may also contain adjuvants such as preserving, wetting, emulsifying, and dispersing agents. They may be sterilized by, for example, filtration through a bacteria-retaining filter, by incorporating sterilizing agents into the compositions, by irradiating the compositions, or by heating the compositions. They can also be manufactured in the form of sterile solid compositions which can be dissolved in sterile water, or some other sterile injectable medium immediately before use.
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1-Cycloalkyl phosphonium salts represented by the formula ##STR1## wherein: R is selected from the group consisting of lower alkyl, hydroxy lower alkyl, halo lower alkyl, amino lower alkyl, cyano lower alkyl, lower alkenyl with the limitation that the double bond is not on the carbon atom attached to the oxygen atom, benzyl, substituted benzyl and ##STR2## wherein q is 0 or 1 and R 4 is selected from the group consisting of hydroxy, loweralkoxy, phenyl, substituted phenyl, and ##STR3## wherein R 5 and R 6 are the same or different members of the group consisting of hydrogen and loweralkyl or taken together form a 5 or 6 membered ring; m is 1, 2 or 3; n is 0 or 1; o is 0 or 1; p is 0 or 1; R 1 , R 2 and R 3 are the same or different members of the group consisting of hydrogen, lower alkyl, lower alkoxy and halo; and X is a pharmaceutically acceptable anion. The compounds are useful as analgesic agents.
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RELATED APPLICATIONS
The present application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/758,011 filed on Jan. 11, 2006, titled “METHODS AND APPARATUS FOR USING BEACON SIGNALS FOR IDENTIFICATION, SYNCHRONIZATION OR ACQUISITION IN AN AD HOC WIRELESS NETWORK”, U.S. Provisional Patent Application Ser. No. 60/758,010 filed on Jan. 11, 2006, titled “METHODS AND APPARATUS FOR FACILITATING IDENTIFICATION, SYNCHRONIZATION OR ACQUISITION USING BEACON SIGNALS”, U.S. Provisional Patent Application Ser. No. 60/758,012 filed on Jan. 11, 2006, titled “METHODS AND APPARATUS FOR USING BEACON SIGNALS IN A COGNITIVE RADIO NETWORK”. U.S. Provisional Patent Application Ser. No. 60/863,304 filed on Oct. 27, 2006, U.S. Provisional Patent Application Ser. No. 60/845,052 filed on Sep. 15, 2006, and U.S. Provisional Patent Application Ser. No. 60/845,051 filed on Sep. 15, 2006, each of which is hereby incorporated by reference and all of which are assigned to the assignee hereof.
FIELD
The present invention is directed to methods and apparatus for signaling in wireless communication and, more particularly, to methods and apparatus for using beacon signals for detecting spectrum availability in a radio network, e.g., a cognitive radio network.
BACKGROUND
Wireless spectrum is an expensive and valuable resource but significant portions of spectrum often go unused. The concept of cognitive radio allows wireless devices to discover and use locally available and usable spectrum for communication. The wireless device should be able to sense its environment, including its location, and then be able to alter its communication parameters, including power and carrier frequency, so as to dynamically reuse available spectrum. A key technical challenge of cognitive radio is to detect the availability of the spectrum in a robust and power efficient manner. For example, when a terminal just powers up or moves into a new area, the terminal may not have knowledge of the communication parameters or even technologies that may be currently used in the vicinity of the geographical area. The detection method has to be robust, e.g., against various uncertainties including the lack of timing and frequency synchronization. Power efficiency has great impact on the battery life of the terminals and is thus another important issue in wireless systems.
In view of the above discussion, it should be appreciated that there is a need for new and improved ways for detecting spectrum availability in a radio network.
SUMMARY
In accordance with various embodiments, before a wireless terminal starts to use a spectrum band, the wireless terminal is to scan a spectrum band to determine whether the spectrum band is available for use. The step of scanning includes searching for a beacon signal in the spectrum band.
In one exemplary embodiment, a beacon signal includes a sequence of beacon signal bursts in a spectrum band, each beacon bust including one or more beacon symbols. A beacon symbol is transmitted using a beacon symbol transmission unit. A beacon signal burst includes one or more beacon symbols with the number of beacon symbols occupying a small fraction of the beacon symbol transmission units of the beacon symbol burst, e.g., ≦10%. In some exemplary orthogonal frequency division multiplexing (OFDM) systems, each beacon symbol is a single tone over an OFDM symbol period. In some exemplary orthogonal frequency division multiplexing (OFDM) systems, each beacon symbol is a single tone over a small number, e.g., one, two, three or four, OFDM symbol periods. A beacon signal burst, in some embodiments, includes one or more tones e.g., a single tone or a small number of tones such as two three or four tones, which are used to convey beacon symbols over a small number of transmission symbol time periods, e.g., one or two symbol transmission time periods. The beacon signal bursts are transmitted in an intermittent (i.e., non-continuous) manner so that there are a number of symbol periods between a first and a second beacon signal bursts. Successive beacon signal bursts may, and sometimes do, use different tones for the beacon symbols according to a predetermined or pseudo random tone hopping sequence.
In accordance with various embodiments, a beacon signal can be used to carry a small amount of information. In an exemplary OFDM system, information can be contained in the frequency of the tone(s) of the beacon symbol in a given burst, the time interval between successive bursts, and/or the tone hopping sequence. The information carried by the beacon signal, in various embodiments, includes at least one of the following about the transmitter: the identifier, the type, the priority level, the current transmission power value, and maximum power information, e.g., the maximum power that the transmitter is capable of transmitting.
If the wireless terminal has not detected any beacon signal in the step of searching for a beacon signal, then, in some embodiments, the spectrum band is available to be used by the terminal. Otherwise, in one embodiment, the wireless terminal is not allowed to use the spectrum band.
If the wireless terminal determines that a candidate spectrum band is available for use, the wireless terminal may start to use the spectrum, e.g., transmitting/receiving data or control signals or establishing peer-to-peer communication sessions with another wireless terminal. In one embodiment, the transmission power of the wireless terminal is a function of the type or the priority level of the wireless terminal.
In accordance with one aspect of various embodiments, while the wireless terminal is using the spectrum, the wireless terminal transmits its own user beacon signal in the spectrum band. The user beacon signals transmitted by different wireless terminals may be, and sometimes are, different from each other with information carried by the beacon signals. In one embodiment, wireless terminals are of different service priority levels and correspond to different user beacon signals.
In accordance with another aspect of various embodiments, while the wireless terminal is using the spectrum, the wireless terminal listens to the spectrum and attempts to detect a beacon signal, which may be sent by another wireless terminal. The wireless terminal may continuously be in the listening mode (i.e., on time) for a time interval of a few symbol periods. The on time is followed by an off time during which the terminal is in a power saving mode and does not receive any signal, e.g., turn off the receive modules. Alternatively, the wireless terminal may continuously be in the listening mode while the wireless terminal is using the spectrum.
In one embodiment, when a first wireless terminal detects the presence of a user beacon signal from a second wireless terminal, irrespective of whether the first wireless terminal is currently using the spectrum band or not, the wireless terminal needs to compare the priority level. If the priority level of the second wireless terminal is higher, the first wireless terminal considers the spectrum band unavailable for use. Moreover, the first wireless terminal shall stop using the spectrum band if the first wireless terminal is currently using the spectrum band, so that higher priority users or services can use the spectrum band without the interference from the first wireless terminal. If the priority level of the second wireless terminal is lower, the first wireless terminal considers the spectrum band available for use. If the first wireless terminal has not been using the spectrum, the first wireless terminal may start to transmit its own user beacon signal. In some embodiments, the first wireless terminal derives the timing and/or frequency of the second wireless terminal from the detected beacon signal, and then uses that information to determine the timing and/or frequency to transmit its own user beacon signal. Assuming that the second wireless terminal is also listening to detect a user beacon signal, advantageously, the above synchronization helps the user beacon signal of the first wireless terminal to be received by the second wireless terminal, so that the second wireless terminal will stop using the spectrum.
In accordance with another aspect of various embodiments, the wireless terminal estimates the path loss between the wireless terminal and the corresponding transmitter of the detected beacon signal. The estimation can be, and sometimes is, based on the received power of the beacon signal. If the path loss is sufficiently great, e.g., greater than a predetermined level, then the wireless terminal can use the spectrum band.
In accordance with various embodiments, in a geographic area, if any communication mode e.g., wireless terminal or base station, is in a data session in a spectrum band, then the node is required to transmit a node beacon signal in the spectrum band. In the data session, the mode may be transmitting or receiving control or data signals. In the area, different modes may co-exist, with each wireless terminal using at least one of a variety of services, such as cellular phone, wireless local loop, digital television, etc., which may be supported by different technologies.
An exemplary method of operating a wireless communications devices, in accordance with various embodiments includes: monitoring during a first period of time to detect at least a portion of a beacon signal including at least one beacon signal in a first communications band; and when a beacon signal portion including at least one beacon symbol is not detected during said first period of time, transmitting a first signal during a second period of time following said first period of time. An exemplary wireless communications device in accordance with various embodiments includes: a beacon detections module for detecting receipt of at least one beacon symbol communicated in a first communications band; a transmitter; and a transmission control module for controlling signal transmission as a function of an output of said beacon detection module, said transmission control module controlling said transmitter to transmit a first signal during a second period of time following a first period of time when a beacon signal portion including at least one beacon symbol is not detected during said first period of time.
While various embodiments have been discussed in the summary above, it should be appreciated that not necessarily all embodiments include the same features and some of the features described above are not necessary but can be desirable in some embodiments. Numerous additional features, embodiments and benefits are discussed in the detailed description which follows.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates an exemplary cognitive radio network in a geographic area implemented in accordance with various embodiments.
FIG. 2 illustrates a ladder diagram of an exemplary method of using beacon signals to control the use of the spectrum band in a cognitive radio network implemented in accordance with various embodiments.
FIG. 3 illustrates different exemplary beacon signals, e.g., system and/or user beacon signals, implemented in accordance with various embodiments.
FIG. 4 illustrates an example of utilizing timing synchronization information implemented in accordance with various embodiments.
FIG. 5 illustrates a flowchart of a method used by an exemplary wireless terminal implemented in accordance with various embodiments.
FIG. 6 illustrates one embodiment of monitoring for beacon signal bursts and transmitting a beacon burst in accordance with a predicted beacon monitoring interval.
FIG. 7 illustrates a detailed illustration of an exemplary wireless terminal implemented in accordance with various embodiments.
FIG. 8 comprising the combination of FIG. 8A and FIG. 8B is a drawing of a flowchart of an exemplary method of operating a wireless communications device, e.g., a wireless terminal such as a mobile node, in accordance with various embodiments.
FIG. 9 is a drawing of an exemplary wireless terminal, e.g., mobile node, implemented in accordance with various embodiments.
FIG. 10 is a drawing of a flowchart of an exemplary method of operating a wireless communications device in accordance with various embodiments.
FIG. 11 is a drawing of an exemplary wireless terminal, e.g., mobile node, implemented in accordance with various embodiments.
FIG. 12 is a drawing of a flowchart of an exemplary method of operating a wireless communications device in accordance with various embodiments.
FIG. 13 is a drawing of an exemplary wireless terminal, e.g., mobile node, implemented in accordance with various embodiments.
DETAILED DESCRIPTION
FIG. 1 illustrates an exemplary cognitive radio communication network 100 implemented in accordance with various embodiments. Two wireless terminals, namely a first wireless terminal 102 and a second wireless terminal 104 are present in a geographic area 106 . A system terminal 105 ; e.g., including a system beacon transmitter, is included in some embodiments. Some spectrum band is available to be used by the two terminals for the purpose of communication, e.g., peer-to-peer communication.
In a cognitive radio network, there is usually no network infrastructure. Various described novel methods, apparatus and features may be used in various radio networks but are particularly well suited for use in networks where infrastructure is limited or lacking e.g., in a cognitive radio network where a wireless terminal may need to discover the information about the network. The wireless terminals may not have a common timing or frequency reference. Indeed, in such a network, the wireless terminals need to figure out whether a given spectrum band is available to be used by the wireless terminal in the current geographic area. A key idea of cognitive radio is to let a wireless terminal sense its environment and discover available spectrum. Spectrum availability is a function of the environment.
FIG. 2 illustrates a ladder diagram 200 of an exemplary method of using beacon signals to control the use of the spectrum band in a cognitive radio network implemented in accordance with various embodiments.
The vertical axis 201 represents time. There are three exemplary terminals, WT A 202 , WT B 204 and WT C 206 in this exemplary cognitive radio network. Assume that initially none of the wireless terminals ( 204 , 206 , 208 ) are powered on.
First, wireless terminal A 202 is powered on. Before wireless terminal A 202 can use the spectrum band, it first scans the band to search for user beacon signals ( 208 ). Since wireless terminal A 202 is the only active terminal in the area, it does not detect any user beacon signal. Thus, wireless terminal A 202 determines that the spectrum band is available for use ( 210 ). Wireless terminal A 202 starts to use the spectrum ( 212 ). Wireless terminal A 202 broadcasts its user beacon signal to show its presence ( 214 ).
At a later time, wireless terminal B 204 is powered on. Before wireless terminal B 204 can use the spectrum band, it first scans the band to search for user beacon signals ( 216 ). Wireless terminal B 204 detects the user beacon signal sent by terminal A ( 218 ). Wireless terminal B 204 furthermore learns, e.g., from the detected beacon signal or another broadcast channel of wireless terminal A, that wireless terminal A is available for peer-to-peer communication ( 220 ). So wireless terminal B 204 determines to use the spectrum ( 222 ). Wireless terminals A and B ( 202 , 204 ) set up a peer-to-peer session ( 224 ). Since both wireless terminals ( 202 , 204 ) are active, they both broadcast user beacon signals ( 228 and 226 ), respectively. In some embodiments, either wireless terminal broadcasts its own user beacon signal. In other embodiments, the two terminals ( 202 , 204 ) determine the priority level of their sessions and use that to determine the user beacon signals to be sent. For example, the session priority level is the maximum priority level of either terminal.
At a later time, wireless terminal C 206 is powered on. Before wireless terminal C 206 can use the spectrum band, it first scans the band to search for user beacon signals ( 230 ). Wireless terminal C 206 detects the user beacon signal sent by wireless terminal A 202 and/or by wireless terminal B 204 ( 232 ). Wireless terminal C 206 furthermore learns, e.g., from the detected beacon signal or another broadcast channel of wireless terminal A or B, that there is an ongoing session ( 234 ). Wireless terminal C 206 also learns the priority levels of detected beacon signals and compares them with its own priority level ( 236 ). If the priority level of wireless terminal C 206 is lower, then wireless terminal C 206 determines that the spectrum band is not available ( 238 ); otherwise wireless terminal C 206 may start to transmit its own user beacon signal. In such a case, both wireless terminals A and B ( 202 , 204 ) will detect the user beacon signal from wireless terminal C 206 , and have to stop/suspend their session and stop using the spectrum.
In accordance with various embodiments, a beacon signal includes a sequence of beacon signal bursts in a spectrum band, each beacon signal burst including one or more beacon symbols. A beacon symbol is transmitted using a beacon symbol transmission unit. A beacon signal burst includes a small number of beacon symbols, with the number of beacon symbols occupying a small fraction of the beacon symbol transmission units of the beacon signal burst. In some exemplary OFDM systems, a beacon symbol is a tone over an OFDM symbol period. In some exemplary OFDM systems, a beacon symbol is a tone over a small number, e.g., one, two, three, or four of successive, OFDM symbol periods. In some embodiments, a beacon signal burst includes one or more tones, e.g., a single tone or a small number such as two, three or four tones, which are used to convey beacon symbols, over a small number of transmission symbol periods, e.g., one or two symbol periods. The wireless transmitter transmits the beacon signal bursts in an intermittent (i.e., non-continuous) manner so that there are a number of symbol periods between a first and a second beacon signal bursts. FIG. 3 illustrates in drawing 300 and 350 exemplary beacon signals in an exemplary OFDM system.
In drawing 300 the horizontal axis 302 represents time and the vertical axis 304 represents frequency. A vertical column represents each of the tones in a given symbol period. Each small box 306 represents a tone-symbol, which is a single tone over a single transmission symbol period. In drawing 350 the horizontal axis 352 represents time and the vertical axis 304 represents frequency. A vertical column represents each of the tones in a given symbol period. Each small box 356 represents a tone-symbol, which is a single tone over a single transmission symbol period. A minimum transmission unit in the OFDM symbol is a tone-symbol. In this exemplary embodiment, a beacon symbol transmission unit is an OFDM tone-symbol.
The beacon signal includes a sequence of beacon signal bursts, which are transmitted sequentially over time, each beacon symbol burst including one or more beacon symbols. A beacon signal burst, in various embodiments, includes a small number of tones which convey beacon symbols, e.g., a single tone, over a small number of transmission symbol periods, e.g., one or two symbol periods. Drawing 300 of FIG. 3 shows four small black boxes ( 308 , 310 , 312 , 314 ), each of which represents a beacon symbol. In this case, a beacon symbol uses the air link resources of one tone-symbol. In another exemplary embodiment, a beacon symbol uses one tone transmitted over two consecutive symbol periods and uses the air link resource of two OFDM tone-symbols.
The beacon symbol tone or tones of the beacon signal may vary (hop) from one burst to another. In accordance with various embodiments, the tone-hopping pattern, including the tones used for the beacon symbol or symbols and the inter-burst interval, of the beacon signal are, in some embodiments, a function of the transmitter, e.g., a terminal, and can be used as an identification of the transmitter or an identification of the type to which the transmitter belongs, or to indicate the transmission power or the power capability of the terminal.
Different user beacon signals are, in some embodiments, different from each other in at least one of the following ways: the periodicity of the beacon signal bursts, the tone or tones used for the beacon symbols in a beacon signal burst, and the hopping pattern of the beacon symbol tones used in successive beacon signal bursts.
For example, FIG. 3 shows two exemplary beacon signals ( 324 , 374 ). Consider that first beacon signal 324 is a first user beacon signal is sent by a first wireless terminal and includes beacon signal burst ( 316 , 318 , 320 , 322 ) and beacon symbols ( 308 , 310 , 312 , 314 ), respectively. The second beacon signal 374 sent by a second wireless terminal includes beacon signal bursts ( 366 , 368 , 370 , 372 ) and beacon symbols ( 358 , 360 , 362 , 364 ), respectively. The upper portion 300 shows a user beacon signal 324 sent by one wireless terminal, and the lower portion 350 shows another user beacon signal 374 sent by another wireless terminal. In the example, the two beacon signals have the same periodicity, but different tone hopping sequences. Specifically, the tones of the exemplary first wireless terminal beacon signal 324 follow a first slope, and the tones of the exemplary second wireless terminal user beacon signal 374 follow a second slope, where the first slope is greater than the second slope.
In some embodiments exemplary system beacon signals, e.g., beacon signals from base stations and/or fixed location beacon transmitters, follow a first slope or first set of slopes and exemplary user beacon signals follow a second slope or second set of slopes, the first slope being different from the second slope and/or the first set of slopes being non-overlapping with the second set of slopes.
In one exemplary embodiment, suppose that a high priority service, e.g., law enforcement or fire department service, and a low priority service, e.g., general data service, share the spectrum band. Most of time, the high priority service does not have any activity, during which the spectrum band can be used entirely by the low priority service. However, when the high priority service needs to use the spectrum, it is desired that the low priority service shall stop. The sessions associated with the low priority service shall be terminated. To achieve this objective, in accordance with various embodiments, terminals associated with different service levels use different user beacon signals, e.g., to signal different priority levels.
Consider an exemplary embodiment. When the wireless terminal is scanning the spectrum band for availability, or when the wireless terminal has already been in a communication session using the spectrum band, the wireless terminal shall keep on searching for user beacon signals. If the wireless terminal detects the presence of a user beacon signal with higher priority than its own, then the wireless terminal considers the corresponding spectrum band as unavailable for use. The wireless terminal shall terminate the communication session, if any, and may proceed to scan another candidate spectrum band. This results in clean spectrum band to be used by high priority terminals or services.
Drawing 400 of FIG. 4 illustrates one embodiment of monitoring for beacon signal bursts implemented in accordance with various embodiments. The wireless terminal listens to the spectrum band and attempts to detect a user beacon signal, which may be sent by a different wireless terminal. The wireless terminal may continuously be in the listening mode for a time interval of a few symbol periods, which is called on time. The on time ( 402 ) is followed by an off time ( 406 ) during which the wireless terminal is in a power saving mode and does not receive any signal. In the off time, the wireless terminal may completely turn off the receive modules. When the off time 406 ends, the wireless terminal resumes to the on time 404 and starts to detect for beacon signals again. The above procedure repeats.
In some embodiments, the length of an on time interval is shorter than that of an off time internal. In one embodiment, an on time interval is less than or equal to ⅕ of an off time interval. In one embodiment, the length of each of the on time intervals are the same, and the length of each of the off time intervals are also the same.
The length of an off time interval depends, in some embodiments, on the latency requirement for a first wireless terminal to detect the presence of another (second) wireless terminal if the second wireless terminal is actually present in the vicinity of the first wireless terminal. The length of an on time interval is determined so that the first wireless terminal has a great probability of detecting a least one beacon signal burst in the on time interval. In one embodiment, the length of the on time interval is a function of at least one of the transmission duration of a beacon signal burst and the duration between successive beacon signal bursts. For example, the length of the on time interval is at least the sum of the transmission duration of a beacon signal burst and the duration between successive beacon signal bursts.
FIG. 5 illustrates a flowchart 500 of an exemplary method of operating a wireless terminal used by an exemplary first wireless terminal implemented in accordance with various embodiments. Operation of the exemplary method starts in step 501 , where the first wireless terminal is powered on and initialized, and proceeds to step 502 .
In step 502 , the exemplary first wireless terminal may start by scanning the spectrum band to search for user beacon signals. Then, in step 504 , the first wireless terminal checks whether a user beacon signal from a second wireless terminal has been detected. If the answer is NO, then operation proceeds from step 504 to step 516 , where the first wireless terminal determines that the spectrum is available for use. Otherwise, the first wireless terminal has found a beacon signal and operation proceeds from step 504 to step 506 , where the first wireless terminal compares the priority level of the detected user beacon signal with its own priority level. In step 508 , the first wireless terminal checks whether the detected beacon has higher priority level than its own priority level. If the answer is NO, then operation proceeds from step 508 to step 516 , where the first wireless terminal determines that the spectrum is available for use. Otherwise, operation proceeds from step 508 to step 510 . In step 510 the first wireless terminal determines the path loss from the first wireless terminal to the second wireless terminal.
In one embodiment, the beacon signal carries the information about the transmission power of the second wireless terminal. Then the first wireless terminal can determine the path loss from the transmission power and the received power measured by the first wireless terminal. In a special case where each of the beacon signals are sent at the same power level, the beacon signal itself does not have to carry the information about the transmission power of the second wireless terminal. The first wireless terminal can determine the path loss from the known, e.g., predetermined beacon level, transmission power and the received power measured by the first wireless terminal. Operation proceeds from step 510 to step 512 .
In step 512 , the first wireless terminal determines whether the path loss is sufficiently high e.g., in relation to a predetermined stored path loss level. If the answer is yes, then operation proceeds from step 512 to step 516 . In step 516 the first wireless terminal determines that the spectrum is available for use. Otherwise, operation proceeds from step 512 to step 514 , where the first wireless terminal determines that the spectrum is not available for use.
Once the first wireless terminal determines that the spectrum is available for use in step 516 , the first wireless terminal may use the spectrum to establish communication links, e.g., peer-to-peer communication. Operation proceeds from step 516 to step 518 in which the first wireless terminal starts to use the spectrum including transmitting its own user beacon signal. Meanwhile, the first wireless terminal shall periodically be in the on time mode, e.g., with respect to receiver operation, and scan the spectrum band to search for user beacon signals as indicated by step 502 .
Usually the terminals in the cognitive radio network not have a common source from which each of the terminals can derive synchronization information. In accordance with a feature of various exemplary embodiments, the wireless terminals use the timing and/or frequency information derived from a system beacon signal transmitted by a special transmitter, e.g., transmitted by a fixed location system terminal including a beacon transmitter. The fixed location system terminal may or may not be coupled to other network nodes, and may or may not include additional wireless functions in addition to transmitting the beacon signal. In some embodiments, the fixed location system terminal's sole function is to transmit a system beacon signal to be used as a reference by wireless terminals. Advantageously, the terminals now have a common timing and/or frequency reference, thereby being synchronized with each other. To elaborate, drawing 600 of FIG. 6 illustrates an example of utilizing timing synchronization information implemented in accordance with various embodiments.
The horizontal axis 601 represents time. A second wireless terminal transmits its user beacon signal 608 , which includes a sequence of beacon signal bursts, 602 , 604 , 606 , and so on. Now, suppose that a first wireless terminal is powered on and detects those beacon bursts. Assume that the first wireless terminal has higher priority level than the second terminal, and that the first wireless terminal intends to use the spectrum.
The first wireless terminal predicts the on time intervals of the second wireless terminal's receiver, during which the second wireless terminal monitors for other user beacon signal. The prediction is a function of the estimated timing of the detected beacon burst 602 , 604 and 606 . For example, in FIG. 6 , the on time interval of a terminal starts from a time instance that has known time offset 612 from the beginning of a beacon signal burst sent by the same wireless terminal. Therefore, once the first wireless terminal has determined the timing of the beacon bursts of the second wireless terminal transmitter, it is possible to determine the timing of the second wireless terminal receiver from the known relationship.
Rather than sending its user beacon signal at a randomly chosen time instance, in the exemplary scenario show in FIG. 6 , the first wireless terminal chooses to transmit ( 614 ) at the time during which the second wireless terminal is listening ( 610 ). The second wireless terminal detects the user beacon signal sent by the first wireless terminal, and then decides to stop using the spectrum band because its priority level is lower.
Note that in the absence of the above synchronization, it may take much longer time for the second wireless terminal to detect the user beacon signal sent by the first wireless terminal. Otherwise, the second wireless terminal may need to stay in the listening mode for a much longer time interval in order to reduce the latency of detection. The synchronization thus helps the wireless terminals to detect beacon signals much more rapidly and in a more power efficient manner.
FIG. 7 provides a detailed illustration of an exemplary wireless terminal 700 implemented in accordance with various embodiments. The exemplary wireless terminal 700 , depicted in FIG. 7 , is a detailed representation of an apparatus that may be used as any one of wireless terminals 102 and 104 depicted in FIG. 1 . In the FIG. 7 embodiment, the wireless terminal 700 includes a processor 704 , a wireless communication interface module 730 , a user input/output interface 740 and memory 710 coupled together by bus 706 . Accordingly, via bus 706 the various components of the terminal 700 can exchange information, signals and data. The components 704 , 706 , 710 , 730 , 740 of the wireless terminal 700 are located inside a housing 702 .
The wireless communication interface 730 provides a mechanism by which the internal components of the wireless terminal 700 can send and receive signals to/from external devices and another terminal. The wireless communication interface 730 includes, e.g., a receiver module 732 and a transmitter module 734 , which are coupled via a duplexer 738 with an antenna 736 used for coupling the wireless terminal 700 to other terminals, e.g., via wireless communications channels.
The exemplary wireless terminal 700 also includes a user input device 742 , e.g., keypad, and a user output device 744 , e.g., display, which are coupled to bus 706 via the user input/output interface 740 . Thus, user input/output devices 742 , 744 can exchange information, signals and data with other components of the wireless terminal 700 via user input/output interface 740 and bus 706 . The user input/output interface 740 and associated devices 742 , 744 provide a mechanism by which a user can operate the wireless terminal 700 to accomplish various tasks. In particular, the user input device 742 and user output device 744 provide the functionality that allows a user to control the wireless terminal 700 and applications, e.g., modules, programs, routines and/or functions, that execute in the memory 710 of the wireless terminal 700 .
The processor 704 under control of various modules, e.g., routines, included in memory 710 controls operation of the terminal 700 to perform various signaling and processing as discussed below. The modules included in memory 710 are executed on startup or as called by other modules. Modules may exchange data, information, and signals when executed. Modules may also share data and information when executed. In the FIG. 7 exemplary embodiment, the memory 710 of wireless terminal 700 includes a signaling/control module 712 and signaling/control data 714 .
The signaling/control module 712 controls processing relating to receiving and sending signals, e.g., beacon signals, user data signals, messages, etc., management of state information storage, retrieval, processing, scanning, transmission control, priority determination, path loss determination device identification, user identification, and spectrum availability determination. Signaling/control data 714 includes state information, e.g., parameters, status and/or other information relating to operation of the terminal. In particular, the signaling/control data 714 includes various configuration information 916 , e.g., configuration information of type, priority level, transmission power, transmitter power capability, etc. of the terminal. The module 712 may, and sometimes does, access and/or modify the data 714 , e.g., update the configuration information 716 . The module 712 also includes module 711 for scanning a spectrum band to search for system beacon signal in the band; module 713 for transmitting user beacon signal; module 715 for comparing the priority levels of different user beacon signals; module 717 for determining path loss.
FIG. 8 comprising the combination of FIG. 8A and FIG. 8B is a drawing of a flowchart 800 of an exemplary method of operating a wireless communications device e.g., a wireless terminal such as a mobile node, in accordance with various embodiments. The wireless communications device is, e.g., a portable wireless communications device, which may be operated off battery power. The wireless communications device is, e.g., wireless terminal 900 of FIG. 9 .
Operation starts in step 802 , where the wireless communications device is powered on and initialized and proceeds to step 804 . In step 804 , the wireless communications device monitors, during a first period of time, to detect at least a portion of a beacon signal including at least one beacon symbol in a first communications band.
Operation proceeds from step 804 to step 806 . In step 806 , the wireless communications device makes a decision as to whether or not to transmit a first signal based on the result of said monitoring, said first signal including at least one of a beacon symbol and user data. In some embodiments the first signal is a beacon signal. In some embodiments, said user data includes at least one of text data, audio data, image data, game data, and spread sheet data.
Step 806 includes sub-steps 808 , 810 , 812 , 814 , and 816 . In sub-step 808 , the wireless communications device determines if a beacon signal portion including at least one beacon symbol was detected in the monitoring of step 804 . If a beacon symbol portion was detected operation proceeds from step 808 to one of alternative sub-steps 810 and 812 . If a beacon symbol was not detected, operation proceeds from step 808 to step 814 , where the wireless communications device decides not to transmit a signal during a second period of time which follows said first period of time.
In sub-step 810 , the wireless communications device decides to transmit a signal in response to said detected beacon signal portion. In alternative, sub-step 812 , the wireless communications device decodes information communicated by the detected beacon signal portion. Operation proceeds from sub-step 812 to sub-step 816 . In sub-step 816 , the wireless communications device decides whether or not to transmit said first signal based on information included in said decoded information. In various embodiments, sub-step 816 includes one or more of sub-steps 818 and 820 . In sub-step 818 , the wireless communications device decides as a function of type information included in said decoded information. In various embodiments, the type information indicates whether or not a second band is allowed to be used for peer to peer communications. In some embodiments, the type information identifies a second band which is allowed to be used for peer to peer communications. In sub-step 820 , the wireless communications device decides as a function of device identification information included in said decoded information. In some such embodiments, the device identification information identifies at least one of the wireless communications device and a user that is currently using the wireless communications device.
Operation proceeds from step 806 , via connecting node A 822 , to step 824 . In step 824 , the wireless communications device proceeds differently depending upon whether or not the decision of step 806 was to transmit. If the decision was to transmit, then operation proceeds from step 824 to step 826 . If the decision was not to transmit, then operation proceeds from step 824 , via connecting node B 828 , to step 804 , where additional monitoring is performed.
In step 826 , the wireless communications device transmits at least a portion of said first signal during a second time period. In some embodiments, the first signal is transmitted in a second band which is the same as the first communications band. For example, the received beacon signal portion and the first signal, e.g., transmitted beacon signal portion may correspond to peer nodes in a peer to peer communications network and both of the peer nodes may be using the same frequency band for user beacon signaling. In some other embodiments, the first signal is communicated in a second band which is different from the first communications band. For example, the received beacon signal portion may be communicated from a base station or fixed beacon signal transmitter using a different communications band than the band into which the communications device transmits its user beacon-signaling. In some such embodiments, the first and second communications bands are separated and disjoint in the frequency domain. In various embodiments, the first and second communications bands are different size frequency bands.
In some embodiments, step 826 includes sub-step 830 , in which the wireless communications device transmits at least one beacon symbol. For example, the at least one beacon symbol is a single beacon symbol or a small number of beacon symbols in a beacon burst, e.g., with the beacon symbols occupying <10% of the beacon symbol transmission units of the beacon burst.
Operation proceeds from step 826 to one of steps 832 and 834 . In step 832 , the wireless communications device transmits user data, e.g., during a third time period, into a third communications band, said third time period following said second time period. For example, during the second time period the wireless communications device transmits at least a portion of the first signal including at least one beacon symbol, e.g., to identify its presence, and during the third time period, the wireless communications device transmits user data to a peer. In various embodiments, the third frequency band is the same as the second frequency band. For example, the wireless communications device may transmit both a user beacon signal and user data for peer to peer communications into the same frequency band. In some other embodiments, the second frequency band is different from the third frequency band. For example, there may be distinct frequency bands for user beacon signals and for user data signals.
Operation proceeds from step 832 to step 834 . In step 834 , the wireless communications device monitors during a fourth time period to detect at least a portion of an additional beacon signal from another wireless communications device, e.g., from a peer in a peer to peer communications network. Step 834 includes, in some embodiments, sub-step 836 . In sub-step 836 , the wireless communications device monitors a second frequency band, different from said first frequency band, for at least a portion of an additional beacon signal.
FIG. 9 is a drawing of an exemplary wireless terminal 900 , e.g., mobile node, implemented in accordance with various embodiments. Exemplary wireless terminal 900 may be any of the exemplary wireless terminals ( 102 , 104 ) of system 100 of FIG. 1 .
Exemplary wireless terminal 900 includes a receiver module 902 , a transmitter module 904 , a processor 906 , user I/O devices 908 , and memory 910 coupled together via a bus 912 over which the various elements may interchange data and information. Memory 910 includes routines 914 and data/information 916 . The processor 906 , e.g., a CPU, executes the routines 914 and uses the data/information 916 in memory 910 to control the operation of the wireless terminal 900 and implement methods.
Receiver module 902 , e.g., an OFDM receiver, is coupled to receive antenna 903 via which the wireless terminal receives signals from other wireless communications devices, e.g., other wireless terminals and/or system terminals such as base stations and/or fixed location beacon transmitters. Received signals include, e.g., beacon signals from wireless terminals, beacon signals from system nodes, and handshaking signals and user data signals from wireless terminals, e.g., in peer-to-peer communications.
Transmitter module 904 , e.g., an OFDM transmitter, is coupled to transmit antenna 905 , via which the wireless terminal 900 transmits signals to other wireless communications devices, e.g., peer nodes. In some embodiments, the same antenna is used for receiver module 902 and transmitter module 904 , e.g., with the receiver and transmitter modules ( 902 , 904 ) being coupled to the antenna via a duplexer module. Signals transmitted by the transmitter module 904 include, e.g., a first signal such as a beacon signal or beacon signal portion including at least one beacon symbol. Other signals transmitted by transmitter module 904 include peer-to-peer communication session establishment signals and user data signals.
User I/O devices 908 include, e.g., microphone, keypad, keyboard, switches, camera, speaker, display, etc. User I/O devices 908 allow a user of wireless terminal 900 to input data/information, access output data/information, and control at least some functions of the wireless terminal 900 .
Routines 914 include communications routines 918 and wireless terminal control routines 920 . The communications routines 918 implement various communications protocols used by the wireless terminal. Wireless terminal control routines 920 include a beacon detection module 922 , a beacon based decision module 924 , a beacon signaling decoding module 926 , a beacon signal generation module 928 , a control module 930 and a wireless terminal beacon detection module 932 .
Beacon detection module 922 detects receipt of one or more beacon symbols communicated in a first communications band. Beacon based decision module 924 determines whether or not to transmit a first signal based on an output of the beacon detection module 922 , said output being a function of whether or not a beacon symbol was detected during a time period, said first signal including at least one of a beacon symbol and user data. Beacon signaling decoding module 926 decodes information communicated by a detected beacon signal portion at least one detected beacon symbol being part of said detected beacon signal portion. In some embodiments, the beacon based decision module 924 makes the decision whether or not to transmit a first signal based on decoded information generated by the decoding performed by the beacon signal decoding module. In some embodiments, the beacon based decision module 924 makes a decision not to transmit a signal during a second time period which follows a first time period when at least a portion of a beacon signal including a beacon symbol is not detected by said beacon detection module during the first period of time. In some embodiments, the beacon based decision module 924 makes the decision whether or not to transmit a signal based on type information included in the decoded information, said type information indicating that a second band is allowed to be used for peer-to-peer communications. In some embodiments, the beacon based decision module 924 makes the decision whether or not to transmit a signal based on device information included in the decoded information.
Beacon signal generation module 928 generates beacon signals, said generated beacon signals communicating an identifier used to identify at least one of: i) said wireless communications device and ii) a user that is currently using said wireless communications device. Control module 930 controls the band in which the receiver and transmitter operate. Control module 930 includes a user data transmission control module 931 . In some embodiments said receiver and transmitter are controlled to use the same band in a time division multiplexed basis. In some embodiments, the receiver is controlled to use a first communications band and the transmitter is controlled to use a second communications band, said first and second communications bands being different bands. In some embodiments, the first and second communications bands are separated and disjoint in the frequency domain but have a predetermined relationship. In some such embodiments, the first and second communications bands are different size frequency bands.
User data transmission control module 931 controls the transmission of user data into a third communications band during a third period. In some embodiments, the third time period follows a second time period, said second time period being a time period during which at least a portion of said first signal is transmitted, said first signal including at least one beacon symbol. In some embodiments, the third communications band is the same as the second communications band. In some embodiments, the third communications band is different from the second communications band.
Wireless terminal beacon detection module 932 detects beacon symbols from other wireless communications devices during a fourth period of time, at least a portion of said fourth period of time being different from a time period during which said beacon detection module 922 is operated. The other wireless communications devices are, e.g., peer nodes in a peer to peer communications network. In some embodiments, the wireless terminal beacon detection module 932 monitors a second communications band, said second communications band being a different frequency band than said first communications band.
Data/information 916 includes detected beacon signal information 934 , information recovered from decoded beacon signal portions (information recovered from a decoded beacon signal portion corresponding to a 1 st beacon signal 936 , . . . , information recovered from a decoded beacon signal portion corresponding to an Nth beacon signal 938 ), transmission decision information 940 , device identification information 950 , user identification information 952 , first signal information 954 , current time period information 960 , receiver frequency band selection information 962 , transmitter frequency band selection information 964 , peer to peer network communication session information 966 and system data/information 968 .
Information recovered from a decoded beacon signal portion corresponding to a 1 st beacon signal 936 includes, in some embodiments, one of more of type information 942 and identification information 944 . The type information 942 is, e.g., frequency band type designation information. The type information 942 may, and sometimes does indicate that the band type is designated to be used for peer-peer communications. The identification information 944 is, e.g., device identification information and/or user identification information.
Information recovered from a decoded beacon signal portion corresponding to a N th beacon signal 938 includes, in some embodiments, one of more of type information 946 and identification information 948 . The type information 946 is, e.g., frequency band type designation information. The identification information 948 is e.g., device identification information and/or user identification information.
First signal information 956 includes, in some embodiments, one or more of beacon symbol information 956 and user data 358 . Beacon symbol information 956 includes, e.g., information identifying the beacon transmission units used to convey beacon symbols, e.g., within beacon bursts of the beacon signal included in the first signal, tone hopping pattern information, and/or time information corresponding to the beacon symbols. User data 958 includes data information such as voice data, other types of audio data, image data, text data, file data, etc. of the first signal, e.g., corresponding to data symbols of the first signal.
System data/information 968 includes timing/frequency structure information 970 , beacon decoding information 976 , decision criteria information 978 and beacon encoding information 980 . Timing/frequency structure information 970 includes frequency bands' information 972 and time periods' information 974 . Frequency bands' information 972 includes information identifying a plurality of different frequency bands, which are at times used by the wireless terminal. Frequency bands' information 372 also includes information relating beacon signals to frequency bands. In some embodiments, different bands are used for different purposes. For example, one frequency band, in some embodiments, is used for beacon signaling and another frequency band is used for user data signaling. In some embodiments, at least some frequency bands are used for multiple purposes, e.g., user data beacon signaling and wireless terminal beacon signaling. In some embodiments, the same band is used, at different times for different purposes, e.g., a frequency band typically used for wireless communications via a base station, in some embodiments, is at times, used for peer-to-peer communications. Time periods' information 974 includes, e.g., information identifying in a timing structure when the wireless terminal should receive beacon signals, transmit beacon signals and communicate user data signals to a peer node.
Beacon decoding information 976 , e.g., information mapping various potential detected beacon signals to recovered information, e.g., frequency band type designation information, device ID information, user ID information, and/or priority level information, is used by beacon signal decoding module 926 to recover information ( 936 , . . . 938 ), e.g., when processing beacon symbol information 934 .
FIG. 10 is a drawing of a flowchart 1000 of an exemplary method of operating a wireless communications device in accordance with various embodiments. The wireless communications device is, e.g., a portable wireless terminal such as a mobile node which may be operated using battery power. The wireless communications device is, wireless terminal 1100 of FIG. 11 . Operation starts in step 1002 , where the wireless communications device is powered on and initialized. Operation proceeds from start step 1002 to step 1004 . In step 1004 , the wireless communications device monitors during a first period of time to detect at least a portion of a beacon signal including at least one beacon symbol in a first communications band. In some embodiments, a beacon signal portion communicates an identification value. For examples, the identification value can be one of a device identifier and a user identifier.
Then, in step 1006 operation proceeds differently depending upon whether or not at least a portion of a beacon signal including at least one beacon symbol was detected in step 1004 . If a beacon signal portion was detected, operation proceeds from step 1006 to step 1004 to monitor during another first period of time. However, if a beacon signal portion was not detected, then operation proceeds from step 1006 to step 1008 .
In step 1008 , the communications device transmits a first signal, e.g., at least a portion of second beacon signal including at least one beacon symbol, during a second period of time following said first period of time. In some embodiments, the first signal is transmitted into the first communications band. In some embodiments said second period of time has a fixed time relationship with said first period of time. In various embodiments, the second period of time has a predetermined time offset from the start of the first period of time.
Then, in step 1010 , the wireless communications device transmits user data. The first signal is, in some embodiments, transmitted prior to the user data transmission during non-overlapping time periods. In various embodiments, the user data is also transmitted in the first communications band. Operation proceeds from step 1010 to step 1012 . In step 1012 , the wireless communications device monitors for a response to said user data transmission from another device which with said wireless communications device is communicating on a peer to peer basis.
FIG. 11 is a drawing of an exemplary wireless terminal 1100 , e.g., mobile node, implemented in accordance with various embodiments. Exemplary wireless terminal 1100 may be any of the exemplary wireless terminals ( 102 , 104 ) of system 100 of FIG. 1 .
Exemplary wireless terminal 1100 includes a receiver module 1102 , a transmitter module 1104 , a processor 1106 , user I/O devices 1108 , and memory 1110 coupled together via a bus 1112 over which the various elements may interchange data and information. Memory 1110 includes routines 1114 , and data/information 1116 . The processor 1106 , e.g., a CPU executes the routines 1114 and uses the data/information 1116 in memory 1110 to control the operation of the wireless terminal 1100 and implements methods.
Receiver module 1102 , e.g., an OFDM receiver, is coupled to receive antenna 1103 via which the wireless terminal 1100 receives signals from other wireless communications devices. Receiver module 1102 receives beacon signal portions, e.g., transmitted in a first communications band. Receiver module 1102 also receives session establishment signals and user data signals from peers, as part of peer-peer communications sessions.
Transmitter module 1104 , e.g., an OFDM transmitter, is coupled to transmit antenna 1105 , via which the wireless terminal 1100 transmits signals to other wireless communications devices, e.g., peer nodes. In some embodiments, the same antenna is used for receiver module 1102 and transmitter module 1104 , e.g., in conjunction with duplex module. Transmitted signals include beacon signals, communications session establishment signals and user data signals as part of a peer-peer communications session.
User I/O devices 1108 include, e.g., microphone, keypad, keyboard, switches, camera, speaker, display, etc. User I/O devices 1108 allow a user of wireless terminal 1100 to input data/information, access output data/information, and control at least some functions of the wireless terminal 1100 , e.g., attempt to establish a peer-peer communications session.
Routines 1114 include communications routines 1118 and wireless terminal control routines 1120 . The communications routines 1118 implement various communications protocols used by the wireless terminal 1100 . Wireless terminal control routines 1120 include a beacon detection module 1122 , a transmission control module 1124 , a first signal, e.g., beacon signal portion, generation module 1126 , a beacon symbol generation module 1127 , a beacon information detection module 1128 , a frequency band control module 1130 , a user data transmission control module 1132 , and a response detection module 1134 .
Beacon detection module 1122 detects the receipt of beacon symbols communicated in a first communications band. Transmission control module 1124 controls signal transmission as a function of an output of the beacon detection module 1122 . The transmission control module 1124 controls the transmitter module 1104 to transmit a first signal during a second period of time following a first period of time when a beacon signal portion including at least one beacon symbol is not detected during said first period of time. In some embodiments, the second period of time has a fixed time relationship with the first period of time, e.g., a predetermined time offset with respect to the start of the first period of times.
First signal generation module 1126 generates first signals. For example, an exemplary first signal is a beacon signal portion such as a beacon signal burst including at least one beacon symbol. Beacon symbol generation module 1127 generates beacon symbols, e.g., beacon symbols which are included in generated beacon symbol portions. For example, a beacon symbol is a relatively high power symbol with respect to a data symbol from the transmission perspective of the wireless terminal, facilitating easy detection. For example, the average transmission power difference between a beacon symbol and a data symbol are, in some embodiments, at least 10 dBs. In some embodiments, each of the generated beacon symbols has the same transmission power level. In some embodiments, each generated beacon symbol has the same phase, while generated data symbols may, and generally do have different phase, e.g., as part of a QPSK, QAM16, QAM256, etc. constellation.
Beacon information detection module 1128 determines an identification value communicated by a detected portion of a beacon signal. The identification value is, e.g., one of a device identifier and a user identifier.
Frequency band control module 1130 controls the band in which the receiver module 1102 and transmitter module 1104 operate. In some embodiments, the receiver module 1102 and transmitter module 1104 are controlled to use the same band in a time division multiplexed basis, e.g., with respect to a peer-peer communications session.
User data transmission control module 1132 controls transmission of user data in addition to said first signal in said first communications band. In some embodiments, the first signal is transmitted prior to said user data and the user data transmission control module 1132 control transmission of said user data to occur in a transmission time period which does not overlap with transmission of said first signal. In various embodiments, the user data transmission control module 1132 controls the transmission of user data so that user data is transmitted into the first band, e.g., the same band into which the wireless terminal is transmitting its beacon signal.
Response detection module 1134 detects a response to the user data transmission from another device with which said wireless terminal device is communicating on a peer to peer basis. The response is, e.g., user data from the peer node and/or control information. Control information is, e.g., handshaking information, session establishment information, session termination information, session maintenance information, power control information, timing control information, frequency band information, etc.
Data/information 1116 includes receiver frequency band selection information 1136 , current time information 1138 , transmitter frequency band selection information 1140 , beacon detect/failure to detect flag 1142 , detected beacon signal information 1144 , detected beacon signal portion identification information 1146 , device identification information 1148 , user identification information 1150 , generated first signal information, e.g., generated beacon signal, information 1152 , user data to be transmitted 1154 , detected response information from a peer 1156 , and system data/information 1158 .
Receiver frequency band selection 1136 and transmitter frequency band selections 1140 are outputs of the frequency band selection module 1130 and used by the wireless terminal in controlling the receiver module 1102 and transmitter module 1104 tuning. Beacon detect/failure to detect flag 1142 , e.g., a single bit output, from beacon detection module 1122 , is used by the transmission control module 1124 in making beacon transmission decisions in accordance with the system beacon signaling rules.
Detected beacon signal information 1144 includes information recovered by beacon signal detection module 1122 corresponding to a detected beacon signal, e.g., a set of identified beacon transmission units conveying beacon symbols, a pattern of beacon symbols, a slope associated with detected beacon symbols, etc. Detected beacon signal portion identification information 1146 is an output of beacon information detection module 1128 and is, e.g., a device identifier or user identifier, which identifies the source of the detected beacon signal.
Generated first signal information, e.g., generated beacon signal information 1152 corresponds to the first signal generated by first signal generation module 1126 and includes, e.g., information defining a beacon signal burst including, e.g., beacon symbol tone identification information, null tone identification information, beacon burst duration information, and beacon burst timing information.
User data to be transmitted 1154 includes, e.g., voice, other audio data, image data, text, and/or file data intended for a peer to be communicated under the control of user data transmission control module 1132 , e.g., at the appropriate time, e.g., during a user data interval, in an implemented timing structure. Detected response information from peer 1156 is an output of response detection module 1134 .
System data/information 1158 includes timing/frequency structure information 1160 , beacon encoding information 1168 , and beacon decoding information 1170 . Timing/frequency structure information 1160 includes frequency bands' information 1162 , time periods' information 1164 and time periods' relationship information 1166 .
FIG. 12 is a drawing of a flowchart 1200 of an exemplary method of operating a wireless communications device in accordance with various embodiments. The wireless communications device is, e.g., a portable wireless terminal such as a mobile node which may be operated using battery power. The wireless communications device is, e.g., wireless terminal 1300 of FIG. 13 . Operation starts in step 1202 , where the wireless communications device is powered on and initialized and proceeds to step 1204 . In step 1204 , the wireless communications device receives at least a portion of a beacon signal including at least one beacon symbol from another communications device. Operation proceeds from step 1204 to step 1206 . In step 1206 , the wireless communications device makes a signal transmission decision based on priority information communicated by said received beacon signal portion. The priority information indicates, e.g., one of a device priority, user priority and session priority.
Priority information may be, and sometimes is, coded using a plurality of beacon symbols included in said beacon signal portion. In some such embodiments, priority information is coded at least partially by positions of beacon symbols in a set of beacon symbol transmission units used to communicate said beacon signal portion. In some embodiments, priority information is coded at last partially based on changes in beacon symbol positions in a set of beacon symbol transmission units used to transmit said beacon signal portion over a time period including multiple beacon symbol transmission time periods. In some such embodiments, the beacon symbol transmission units in a set of beacon symbol transmission units correspond to a predetermined tone hopping pattern corresponding to the priority level to be communicated. In various embodiments, a unique beacon symbol pattern is used to communicate a top priority beacon indicating a higher priority than all other beacons used to communicate priority information.
In some embodiments, making a transmission decision includes deciding not to transmit user data when said priority information indicates a higher priority than a priority associated with said wireless communications device. In some embodiments, making a transmission decision includes deciding to transmit user data when said priority information indicates a lower priority than a priority associated with said wireless communications device.
Making a transmission decision may, and sometimes does, include deciding to transmit user data at a transmission power level which is determined as a function of the received priority level and a received power level of the received beacon signal portion. In some embodiments, the transmission power level of the wireless communications device is reduced when the received beacon signal portion indicates a higher priority level than a priority level indicated by a previously received beacon signal portion that was used to control transmission power. In some embodiments, the transmission power level of the wireless communications device is reduced when the received beacon signal portion indicates a lower priority level than a priority level indicated by a previously received beacon signal portion that was used to control transmission power.
Next, in step 1208 , operation proceeds differently depending upon the signal transmission decision of step 1206 . If the signal transmission decision indicates that user data should be transmitted, then operation proceeds from step 1208 to step 1210 . If the signal transmission decision indicates that user data should not be transmitted, then operation proceeds from step 1208 to step 1204 , where the wireless communications device is operated to receive another at least a portion of a beacon signal including at least one beacon symbol.
In step 1210 , the wireless communications device is operated to transmit at least a portion of beacon symbol e.g., a beacon signal burst or a plurality of beacon signal bursts. In various embodiments, the transmitted portion of a beacon signal identifies at least one of said wireless communications device and a user that is using said wireless communications device to transmit user data. In some embodiments, the transmitted beacon signal portion communicates priority information corresponding to said wireless communications device. Operation proceeds from step 1210 to step 1212 . In step 1212 , the wireless communications transmits user data. Operation proceeds from step 1212 to step 1214 .
In step 1214 , the wireless communications device monitors for an additional signal portion including at least one beacon symbol, e.g., said additional signal portion being a portion of a beacon symbol that communicates a higher priority than the priority associated with the wireless communications device. Operation proceeds from step 1214 to step 1216 . In step 1216 , the wireless communications device determines if said additional portion was received during a predetermined period of time.
IF it is determined that said additional portion was not received then operation proceeds from step 1216 to step 1218 , where the wireless communications device transmits a signal. Operation proceeds from step 1218 to step 1214 for additional monitoring for another predetermined period of time.
Returning to step 1216 , if it is determined that said additional portion was not received then operation proceeds from step 1216 to step 1204 , where the wireless communications device is operated to receive another at least a portion of a beacon symbol including at least one beacon symbol.
FIG. 13 is a drawing of an exemplary wireless terminal 1300 , e.g., mobile node, implemented in accordance with various embodiments. Exemplary wireless terminal 1300 may be any of the exemplary wireless terminals ( 102 , 104 ) of system 100 of FIG. 1 .
Exemplary wireless terminal 1300 includes a receiver module 1302 , a transmitter module 1304 , a processor 1306 , user I/O devices 1308 , and memory 1310 coupled together via a bus 1312 over which the various elements may interchange data and information. Memory 1310 includes routines 1314 and data/information 1316 . The processor 1306 , e.g., a CPU, executes the routines 1314 and uses the data/information 1316 in memory 1310 to control the operation of the wireless terminal 1300 and implement methods.
Receiver module 1302 , e.g., an OFDM receiver, is coupled to receive antenna 1303 via which the wireless terminal receives signals from other wireless communications devices. Receiver module 1302 receives signals from other communication devices including at least a portion of a beacon signal including at least one beacon symbol. Received signals include beacon signals and user data signals from peer nodes.
Transmitter module 1304 , e.g., an OFDM transmitter, is coupled to transmit antenna 1305 , via which the wireless terminal transmits signals to other wireless communications devices, e.g., peer nodes. In some embodiments, the same antenna is used for receiver module 1302 and transmitter module 1304 , e.g., in conjunction with a duplex module. Transmitter module 1304 transmits signals including beacon signal portions and user data in accordance with decisions of the signal transmission decision module 1322 . In various embodiments, the transmitted portion of a beacon signal including at least one beacon symbol identifies at least one of: i) wireless communications device 1300 and ii) a user that is using wireless terminal 1300 to transmit user data.
User I/O devices 1308 include, e.g., microphone, keypad, keyboard, switches, camera, speaker, display, etc. User I/O devices 1308 allow a user of wireless terminal 1300 to input data/information access output data/information, and control at least some functions of the wireless terminal 1300 , e.g., attempt to establish a peer-to-peer communication session.
Routines 1314 include communications routines 1318 and wireless terminal control routines 1320 . The communications routines 1318 implement various communications protocols used by the wireless terminal 1300 . Wireless terminal control routines 1320 include a transmission decision module 1322 , a beacon signal generation module 1324 , a monitoring module 1326 , a control module 1328 , a transmission power control module 1330 , and a beacon signal information detection module 1332 .
Transmission decision module 1222 makes a signal transmission decision based on priority information communicated by the received beacon signal portion. The priority information indicates, e.g., one of a device priority, a user priority and a session priority. Transmission decision module 1322 includes a priority based control module 1334 . Priority based control module 1334 prevents transmission of user data when the received priority information indicates a higher priority than a priority associated with said wireless terminal 1300 . In various embodiments, the priority based control module 1334 enables user data transmissions when the received priority information indicates a lower priority than a priority associated with the wireless terminal 1300 .
Beacon signal generation module 1324 generates beacon signal portions, a generated beacon signal portion including at least one beacon symbol. Some beacon signal portions are referred to a beacon burst signals.
Control module 1328 controls monitoring module 1326 to monitor for an additional beacon signal portion including at least one beacon symbol following the transmission decision module 1322 making a signal transmission decision. In some embodiments, if an additional beacon signal portion communicating a higher priority than said priority associated with wireless terminal 1300 is not received in a predetermined period of time, the transmission decision module 1322 makes a decision to transmit a signal.
Transmission power control module 1330 controls a user data transmission power level as a function of at least one of the received priority level and a received power level of the received beacon signal portion. Transmission power control module 1330 includes a transmission power reduction module 1336 . Transmission power reduction module 1336 reduces the transmission power level when the received beacon signal portion indicates a higher priority than a priority level indicated by a previously received beacon signal portion that was used to control transmission power.
Beacon signal information detection module 1332 determines priority information from a set of beacon symbols included in a received beacon signal portion, said priority information being encoded over a plurality of beacon symbols. In some embodiments, the priority information is coded at least partially by positions of beacon symbols in a set of beacon symbol transmission units used to transmit a beacon signal portion. In various embodiments, the priority information is coded at least partially based on changes in beacon symbol positions in a set of beacon symbol transmission units used to transmit a beacon signal portion. In some embodiments, the priority information is coded at least partially based on changes in beacon symbol positions in a set of beacon symbol transmission units used to transmit a beacon signal portion over a period of time including multiple beacon symbol transmission time periods. In various embodiments, the beacon symbol positions a set of beacon symbol transmission units correspond to a predetermined tone hopping pattern corresponding to the priority level to be communicated in some embodiment, a unique beacon symbol pattern is used to communicate a top priority indicating a higher priority than all other beacons used to communicate priority information.
Data/information 1316 includes received beacon signal portion information (received beacon signal port 1 information 1338 , . . . , received beacon signal portion N information 1340 ), transmission decision information 1342 , user data to be transmitted 1344 , current priority associated with the wireless terminal 1346 , user data transmission power level information 1348 , priority level information associated with the received beacon signal portions (priority associated with received beacon signal portion 1 1350 , . . . , priority associated with received beacon signal portion N 1352 ), generated beacon signal portion information 1354 , and beacon signal decoding information 1356 .
Received beacon signal portion 1 information 1338 includes beacon symbol information 1358 and priority information 1360 . Priority information 1370 includes at least one of device priority information 1362 , user priority information 1364 , and session priority information 1366 .
Received beacon signal portion N information 1340 includes beacon symbol information 1368 and priority information 1370 . Priority information 1360 includes at least one of device priority information 1372 , user priority information 1374 , and session priority information 1376 .
Transmission decision 1342 is an output of transmission decision module 1322 , indicating whether or not WT 1300 is permitted to transmit. User data to be transmitted 1344 is, e.g., voice, other audio data, image data, text data, file data, etc. that WT 1300 intends to transmit to a peer in a peer-peer communications session, if authorized.
Current priority associated with the wireless terminal 1346 indicates the current priority level associated with WT 1300 , used by priority based control module 1334 for comparisons. In some embodiments, the current priority of a wireless terminal can, and sometimes does change over times, e.g., as a function of session information and/or user identification information.
Priority associated with received beacon signal portion 1 1350 and priority associated with received beacon portion N 1352 correspond to received beacon signal portions ( 1338 , . . . , 1340 ) respectively, and are used by transmission decision module 1322 .
Generated beacon signal portion information 1354 , e.g., information corresponding to a beacon signal burst including a set of beacon symbols and a set of intentional nulls, is an output of beacon signal generation module 1324 .
User data transmission power level information 1348 includes power level adjustment information 1378 , e.g., information indicating an amount of power reduction to be implemented in response to a beacon signal detected of higher priority.
Beacon signal decoding information 1356 includes beacon symbol position information 1380 and tone hopping pattern/priority level information 1382 . Beacon signal decoding information 1356 is used by beacon signal information detection module 1332 when processing beacon symbol information, e.g., info 1358 , of one or more received beacon signal portion to obtain priority information being conveyed by the beacon signals, e.g. one or more of device priority information 1362 , user device priority information 1364 , and session priority information 1366 .
While described in the context of an OFDM TDD system, the methods and apparatus of various embodiments are applicable to a wide range of communications systems including many non-OFDM, many non-TDD systems, and/or many non-cellular systems.
In various embodiments nodes described herein are implemented using one or more modules to perform the steps corresponding to one or more methods, for example, generating a beacon signal, transmitting a beacon signal, receiving beacon signals, scanning for beacon signals, recovering information from received beacon signals, determining a timing adjustment, implementing a timing adjustment, changing a mode of operation, initiating a communication session, comparing priority levels of user beacon signals, determining path loss, determining a reference from a fixed location beacon transmitter, etc. In some embodiments various features are implemented using modules. Such modules may be implemented using software, hardware or a combination of software and hardware. Many of the above described methods or method steps can be implemented using machine executable instructions, such as software, included in a machine readable medium such as a memory device, e.g., RAM, floppy disk, etc. to control a machine, e.g., general purpose computer with or without additional hardware, to implement all or portions of the above described methods, e.g., in one or more nodes. Accordingly, among other things, various embodiments are directed to a machine-readable medium including machine executable instructions for causing a machine, e.g., processor and associated hardware, to perform one or more of the steps of the above-described method(s).
Numerous additional variations on the methods and apparatus described above will be apparent to those skilled in the art in view of the above descriptions. Such variations are to be considered within scope. The methods and apparatus of various embodiments may be, and in various embodiments are, used with CDMA, orthogonal frequency division multiplexing (OFDM), and/or various other types of communications techniques which may be used to provide wireless communications links between access nodes and mobile nodes. In some embodiments the access nodes are implemented as base stations which establish communications links, with mobile nodes using OFDM and/or CDMA. In various embodiments the mobile nodes are implemented as notebook computers, personal data assistants (PDAs), or other portable devices including receiver/transmitter circuits and logic and/or routines, for implementing the methods of various embodiments.
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Wireless devices, e.g., in a cognitive radio network, discover and use locally available usable spectrum for communication. Beacon signaling facilitates available spectrum discovery, spectrum usage coordination, and device identification. A wireless terminal, which may have entered a new area and powered up, monitors to detect for the presence of beacon signals in a communications band. When the wireless terminal fails to detect a beacon, the wireless terminal assumes that the spectrum is available and transmits its user beacon signal thereby providing notification of its presence in the area to other wireless terminals. The wireless terminal maintains a coordinated timing relationship between its beacon transmit interval and beacon detect interval, which are performed on an ongoing basis. The combination of beacon TX interval and beacon monitoring interval represents a small fraction of total time, allowing for power conservation. The coordinated timing relationship, known to peers, facilitates efficient peer-peer communications session establishment.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to nonvolatile memory, and particularly an EEPROM device suitable for use in programmable logic devices and a method of forming the device.
2. Description of the Related Art
Non-volatile memory devices of the type commonly referred to in the art as EPROM, EEPROM, or Flash EEPROM serve a variety of purposes, and are hence provided in a variety of architectures and circuit structures.
As with many types of integrated circuit devices, some of the main objectives of non-volatile memory device designers are to increase the performance of devices, while decreasing device dimensions and consequently increasing circuit density. Cell designers strive for designs which are reliable, scalable, cost effective to manufacture and able to operate at lower power, in order for manufacturers to compete in the semiconductor industry. EEPROM devices are one such device that must meet these challenges. In some applications, such as flash memory cards, density is at a premium, while in applications such as programmable logic devices (PLD's), reliability is more important and space is at less of a premium. Generally, arrays of individual memory cells are formed on a single substrate and combined with sense and read circuitry, and connected by row-wise and column-wise conductive regions or metallic conductors to allow for array wide bulk program and erase as well as selected bit programming.
Semiconductor process technology has continued to move toward defining smaller device features, and the conventional “stacked gate” EEPROM structure has given way to different cell designs and array architectures, all intended to increase density and reliability in the resulting circuit. In addition, in EEPROM devices used for programmable logic devices, designers strive to reduce power requirements of devices by reducing program and erase voltage requirements.
Conventionally, programmable logic EEPROMS were typically formed by stacked gate devices operating utilizing Fowler-Nordheim tunneling to program and erase the floating gate or in single polysilicon-based cells such as that set forth in U.S. Pat. No. 4,924,278. An alternative to the aforementioned Fowler-Nordheim tunneling-based cell structures is presented in Ranaweera, et al., “Performance Limitations of a Flash EEPROM Cell, Programmed With Zener Induced Hot Electrons,” University of Toronto Department of Electrical Engineering (1997). Discussed therein is a flash EEPROM cell which accomplishes programming and erase by establishing a reverse breakdown condition at the drain/substrate junction, generating hot electrons which are then injected into the floating gate to program the cell. To program the flash ZEEPROM cell, the PN junction is reverse-biased to create an electric field of approximately 10 6 volt/cm. and generate energetic hot electrons independent of the channel length. The P+ region adjacent to the drain enhances this generation. A low junction breakdown voltage can be used for programming by optimizing the PN junction depth and profiles.
A structure and method for programming an avalanche injection cell is detailed in co-pending U.S. patent application Ser. No. 08/871,589, inventors Hao Fang, et al., filed Jul. 24, 1998 and assigned to the assignee of the present application.
In Fang, et al. the non-volatile memory cell is formed of a P substrate having embedded therein an N+ source region, an N-type diffused drain region, a floating gate capacitively coupled to the P substrate through a tunnel oxide, or other gate dielectric such as nitride oxide; and a control gate coupled capacitively to the floating gate through an oxide/nitride/oxide, or other type of inter polysilicon dielectric, film. The diffused region is formed of a shallowly diffused but heavily doped N-type junction, while the source region is formed of a deeply diffused but lightly doped N junction.
To program the cell, electron injection is effected from the drain side. The programming operation is accomplished by applying +3 volts on the drain and −6 volts on the P substrate so as to shift upwardly the threshold voltage V t by 4 volts in approximately 0.002 seconds. To erase, holes are injected from the drain side by applying +6.5 volts on the drain and −3 volts on the P substrate so as to shift down with the voltage threshold V t by 4 volts.
The Fang, et al. application also teaches a single polysilicon layer embodiment wherein the stacked control gate is replaced with a diffusion region. FIG. 1 represents a schematic depiction of such embodiment. The control gate can be switched between 0 volts and V cc to select and de-select the cell during the read period and between V jb and 0 volts to program and erase the cells as set forth above. A select transistor is added at the source side to enable a fast read of the memory cell. Cell size is decreased in comparison to conventional single poly memory cells for programmable logic devices.
Even with the scaling advantages presented by the ZEEPROM-type cells, designers constantly seek to improve scalability, performance and cost advantages of cells.
Each of the aforementioned configurations presents advantages and disadvantages when used in particular applications. Nevertheless, improvements in both the structure of individual cells and the manner in which they are connected together will result in more reliable, stable, faster, and lower power devices which can be programmed and erased at lower voltages.
SUMMARY OF THE INVENTION
In one aspect, the invention, roughly described, comprises a non-volatile memory cell. The cell is formed on and in a semiconductor substrate having a first conductivity type and includes a control region formed of said first conductivity type in a well of a second conductivity type in the substrate. A control region oxide is formed over the control region. The cell includes a program element having a first active region of a second conductivity type formed in said substrate. A doped or implanted impurity region of the first conductivity type is positioned adjacent to said first active region, and an active region oxide overlies at least a portion of the first active region. A floating gate is formed over said semiconductor substrate on said active region oxide and said control gate oxide.
In one aspect, the channel region and the control region are formed simultaneously by, for example, an impurity implant of said first conductivity type into said control region and channel region. Using the cell of the present invention provides advantages in scaling and improves the quality of the oxide formed over the control region.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described with respect to the particular embodiments thereof. Other objects, features, and advantages of the invention will become apparent with reference to the specification and drawings in which:
FIG. 1 is a schematic diagram of the single polysilicon embodiment of the avalanche/Zener injection EEPROM cell of the prior art.
FIG. 2 is a schematic diagram of a first embodiment of an avalanche/Zener injection EEPROM cell of the present invention.
FIG. 3 is a semiconductor cross-section of the avalanche/Zener injection EEPROM cell of the present invention.
FIG. 4 is a schematic diagram of a second embodiment of an avalanche/Zener injection EEPROM cell of the present invention.
DETAILED DESCRIPTION
A novel EEPROM structure, including a buried control gate formed of a p-type impurity, is hereafter disclosed. In the following description, numerous details, for example specific materials process steps, etc., are set forth in order to provide a thorough understanding of the invention. It will be readily understood, however, to one of average skill in the art that specific details need not be employed to practice the present invention. Moreover, specific details of particular processes or structures may not be specifically presented in order to not unduly obscure the invention where such details would be readily apparent to one of average skill in the art. Those having ordinary skill in the art and access to the teachings described herein will recognize additional modifications and applications and embodiments within the scope of the present invention.
FIG. 2 shows a schematic diagram of a first embodiment of a nonvolatile memory cell structure formed in accordance with one aspect of the present invention.
Structure 100 includes an (array) control gate ACG, floating gate FG, avalanche/Zener program element Q w , a read transistor Q r , and a sense element Q c . The array control gate (ACG) 240 is used to accelerate electrons or holes selectively to or from the floating gate FG by capacitively coupling a field across the oxide that separates the avalanche element from the floating gate.
As shown in FIG. 2, sense transistor Q c and avalanche element Q w share floating gate FG 112 . Floating gate FG 112 is capacitively coupled to array control gate (ACG) 240 voltage via capacitor 211 . As shown in FIG. 3, capacitor 211 comprises ACG region 240 and program gate oxide 115 . In the first embodiment shown in FIG. 2, program and erase by hot carrier generation occurs at one junction of the program element Q w , that is, at the p-n junction between region 122 and channel 230 . Program and erase can be separated over separate junctions (i.e. program over the junction between region 122 and channel 230 and erase at the junction between region 124 and channel 230 ) as shown in FIG. 4 .
Program element Q w allows program and erase of EEPROM 100 through generation of hot electrons and hot holes which are swept onto the floating gate upon application of appropriate voltage to the program junction, as described below.
FIG. 3 shows an exemplary cross-section of the embodiment of the EEPROM cell 100 as formed on a semiconductor substrate 105 . It should be understood that numerous ones of such cells are formed in a single integrated circuit device in an array in accordance with well-known techniques. Silicon substrate 105 has a first conductivity type such as a P-type conductivity having a background doping concentration of about 1×10 15 -1×10 17 cm −3 .
Avalanche/Zener program element Q w shares floating gate FG with sense element Q c , and includes a first active region 122 and second active region 124 . Floating gate FG 112 overlies the program element oxide layer 140 , the program junction oxide 115 and sense oxide layer 117 . Floating gate FG is formed of a conducting material, such as a polycrystalline silicon material.
In accordance with the invention, array control gate 240 is formed of a conductivity type the same as the substrate, in this embodiment a p-type impurity, and is provided on one side of the field oxide region 101 . A well region 290 is provided in the substrate 105 prior to formation of the control gate 240 . The n well 290 serves to isolate the control gate region 240 and allow specific selection of the control gate 240 during device operation.
Program element Q w is electrically separated from the ACG 240 by isolation region 101 , and the ACG is separated from sense transistor Q c by isolation region 102 , e.g. silicon dioxide, also formed in the semiconductor substrate 105 . Field oxidation regions 101 and 102 represent a device isolation structure formed in accordance with well known techniques such as LOCOS, trench isolation, shallow trench isolation and various equivalent alternatives. The shape of the isolation depicted in the figures of the present disclosure is not intended to limit the nature of the type of isolation used herein.
A channel 230 is positioned between regions 122 and 124 . Overlying the channel 230 is an oxide layer 140 . The oxide layer 140 is typically composed of an insulating material, such as silicon dioxide, and has a thickness of approximately 80 to 150 angstroms. Oxide layer 140 may be deposited or grown (using conventional oxide deposition techniques) in a single process step.
Prior to formation of the gate stacks (regions 112 / 140 , 112 / 117 and 113 / 114 ), a p+ type impurity implant is made in the substrate to form a p+ region 155 in the channel 230 of the program element Q w adjacent to regions 122 and 124 . Typically an implant of boron at an energy of 30 to 200 KeV, to a depth as great as 0.1 to 0.4 μm in a concentration of about 1×10 18 to 1×10 20 cm −3 is suitable. This p-type impurity implant allows for specific breakdown voltage engineering of the avalanche program element Q w of the cell with a great deal of accuracy. In cell 100 , reverse breakdown voltages in a range of 3V to 10V may be used in order to generate energetic hot carriers independent of the channel length of the device. It should be recognized with reference to Ranaweera, et al., that the breakdown characteristics of the various P+ N+ junctions varies with the concentration of the P+ region 155 .
In an advantageous feature of the invention, the implant utilized to form impurity region 155 can likewise be utilized to form the control gate region 240 and save processing steps. It will be recognized that such implant is advantageous in either the single side embodiment of FIG. 2 or the two-side (program/erase) embodiment of FIG. 4 .
Gate oxide 115 and floating gate 112 are formed in accordance with conventional techniques by, for example, forming a thermal oxide on the surface of substrate 105 , depositing a polysilicon layer on top of the gate oxide, and etching the gate oxide and polysilicon layers to form oxides 114 , 115 , 117 and 140 and floating gate 112 . Various alternative methods are suitable for growing the gate oxide layer and are well within the knowledge of one of average skill in the art. For example, oxide 115 may be grown during the same step or separate steps. Likewise, numerous techniques for forming the floating gate layer may be used, including, but not limited to depositing polysilicon by chemical vapor deposition or sputtering and annealing techniques well known to one of average skill in the art. Etching of the polysilicon and gate oxide layers may be performed by any number of suitable wet or dry directional etch step in accordance with well-known techniques.
Sense transistor Q c shares first active region 132 with read transistor Q r Gate 113 of read transistor Q r is connected to word line WL. Active region 136 of read transistor Q r is connected to a read signal select (product term) PT, while region 134 of sense transistor Qc is connected to sense signal (product term ground) PTG.
A sense transistor channel is formed between region 134 and region 132 . The conductivity of the region 134 and region 132 is of the second conductivity type, for example, an N+ conductivity type. Overlying the sense channel is an oxide layer 117 having an approximate thickness of 80 angstroms. The sense gate oxide layer 117 may also be simultaneously formed with the oxide layer 140 . Depending on the mode of sense transistor Q c (depletion or enhancement mode), the relevant voltages for operating the EEPROM cell 100 are adjusted. The sense transistor Q c is, in one embodiment, a depletion mode transistor, as is commonly understood in the industry. In a further embodiment, the sense transistor Q c is an enhancement mode transistor (also as commonly known in the industry).
The read transistor Q r includes region 132 and region 136 , both formed of the second conductivity type, e.g. an N+ conductivity type. A channel is positioned between regions 132 and 136 . Overlying the read channel is an oxide layer 114 that is composed of an insulating material, such as silicon dioxide, and has an approximate thickness of 25-150 angstroms. Oxide layer 114 may be formed in the same step as the oxide layer 117 , or in a separate step. A read gate 113 overlies the read oxide layer 114 and is composed of a conducting material, such as a polycrystalline silicon material.
Regions 122 , 124 , 132 , 134 and 136 may be formed by an impurity implant of a dopant having a conductivity type opposite to that of the substrate (arsenic or phosphorus, for example) to form self-aligned active regions in substrate 105 . Typical junction depths of 0.1 μm to 0.5 μm and doping concentration of about 5×10 18 to 1×10 21 cm −3 are suitable for regions 134 , 132 and 136 . Substrate 105 may optionally have a connection 107 to allow for biasing the substrate.
Exemplary operational characteristics for the device shown in FIGS. 2 and 3 are given as follows: to add electrons to floating gate FG 112 , the substrate is biased to 0V, region 124 is internally isolated, region 122 is at, for example, 8V and the FG is coupled to a positive voltage from control gate ACG, such as 8V. To remove electrons from FG, the substrate is biased to 0V, region 124 is floating or isolated, second region 122 is at 8V and FG is at a low voltage coupled to the ACG of about 0V. It should be understood that either adding electrons (or removing holes), or removing electrons (or adding holes) can constitute a “program” or “erase” operation, as such “program” or “erase” operation is defined by the context of the overall device in which the non-volatile memory cell is used. It should be noted that the voltage on the product-term ground connection may be varied in accordance with the EEPROM design constraint that a higher voltage will increase program/erase speed, but may induce greater oxide damage, while lower voltages will ensure better oxide qualities, and hence greater data retention integrity, over time.
Typical operating voltages for the foregoing lines in the cell shown in FIG. 2 are given in Table 1:
TABLE 1
WBL
SUBSTRATE
ACG
PT
PTG
WL
Erase
6 v
0 v
8 v
Float
>0-8 v
Vcc
Program
6 v
0 v
0 v
Float
0 v
0 v
In contrast with the cell disclosed in U.S. Pat. No. 4,924,278, the cell of the present invention utilizes the avalanche/Zener injection capacities of the aforementioned prior art to place electrons or holes on the floating gate in accordance with the techniques described therein.
Because of the separate formations for each of the elements, the diode doping gradient for transistor Q w can be selected to control the avalanche breakdown voltage of cell Q w and a scaling of the programming voltage below current known levels.
In a further unique aspect of the present invention, a reduction in program voltage coincident with the avalanche/Zener program element allows a reduction in oxide thickness for all floating gate elements. It should be recognized that the amount of oxide thickness reduction is limited by the necessity to maintain data retention integrity. Separation of the read path and program elements in the present embodiment further allows one to use differing oxides for the read and sense elements.
It should be recognized that the cell described herein may be utilized with any number of coupling arrangements in any number of matrix arrangements shown herein or in the prior art. It should be further recognized that the method of the present invention may be utilized to construct a non-volatile device wherein the operating parameters vary from the exemplary embodiment set forth above.
In the alternative embodiment of the present invention shown in FIG. 4, programming and erase using hot electrons or hot holes generated by Zener/avalanche breakdown performed over different regions of the cell oxide 140 , alternatively any regions 124 / 155 and 122 / 155 improves the quality of oxide 140 over prolonged program and erase.
The many features and advantages of the present invention will be apparent to one of average skill in the art in view of the illustrative embodiments set forth herein. The present invention has been described herein with respect to particular embodiments for a particular applications. It will be apparent to one of average skill in the art that numerous modifications and adaptations of the present invention may be made in accordance with the invention without departing from the spirit of the scope of the invention as disclosed herein and defined by the following claims.
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A non-volatile memory cell, comprising a semiconductor substrate having a first conductivity type. A control region is formed of said first conductivity type in the substrate and a control region oxide formed over the control region. The cell includes a program element having a first active region of a second conductivity type formed in said substrate, a doped or implanted region adjacent to said first active region, and a gate oxide overlying at least the channel region. An active region oxide covers a portion of the first active region. A floating gate is formed over said semiconductor substrate on said active region oxide and said control region oxide.
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BACKGROUND OF THE INVENTION
The invention relates to a method for the continuous cleaning of a honing tool during the operation of a honing machine. The honing tool rests on a rotating workpiece and executes swinging motions parallel to the rotational axis of the workpiece. During the grinding operation, a flushing liquid is applied to the area of contact between the tool and the workpiece. The invention further relates to an apparatus for carrying out the above method.
Such methods and apparatus are known, but they have the disadvantage that the working surface of the honing tool, i.e. that surface which makes contact with a workpiece, supported, for example, without centers on transport rollers, is clogged relatively rapidly with microscopically small fragments from the honing tool and from the workpiece. On the other hand, due to this clogging, any dulled grains of the honing tool can no longer break out of the binder material resulting in a relatively rapid dulling of the entire honing tool. On the other hand, even very minor causes, for example the slight shock due to the passage of edges of sequential workpieces under the honing tool, or a temporary loss of contact of the honing tool from the workpiece will often result in unpredictable, effective resharpening of the honing tool. This variation may result in different material removal rates from one workpiece to the next and thus to a widening of the tolerance limits of the process. Even when relatively large volumes of flushing liquid are used, this disadvantage is not cured, because the relatively large contact surface between the honing tool and the workpiece usually prevents the flushing liquid from reaching all areas of contact in sufficient quantities and with a sufficient intensity so as to remove clogged material everywhere.
OBJECT AND SUMMARY OF THE INVENTION
Accordingly, it is a principal object of the present invention to provide a process, and an apparatus for carrying out this process, which prevents a clogging of the contact surface of the honing tool due to the deposition of fragments of the honing tool itself and/or material removed from the workpiece, which might lead to a rapid decrease of the rate of material removal and which also might lead to uncontrollable widening of the tolerances of the process by unpredictable effective sharpening of the honing tool.
This object is attained, according to the invention, by imparting to the honing tool a high frequency oscillatory motion transverse with respect to the rotational axis of the workpiece and substantially confined to that end of the honing tool which makes contact with the workpiece.
An apparatus for carrying out this method provides that the workpiece and the interface area of the honing tool and the workpiece are all located within a container which is filled with a flushing liquid whose level is higher than the interface area and by providing an ultrasonic generator, located in the vicinity of the side walls of the honing tool, which directs ultrasonic waves to the contact area of the honing tool, the waves being transmitted by the flushing liquid.
The invention is based on the discovery that very small transverse oscillations, such as result from agitating the honing tool by ultrasonic waves, prevent clogging of the contact area of the honing tool with material fragments removed from the honing tool or from the workpiece. Preferably, the flushing liquid also serves as the medium for transmitting the ultrasonic vibrations.
The method according to the invention has special significance when used with honing machines that have a very rigid or stiff machine frame in which incidental transverse oscillations, such as might occur in older machines due to their greater free play, would not be sustained.
The invention will be better understood and further objects and advantages will become more apparent from the ensuing detailed specification of a preferred, but merely exemplary, embodiment taken in conjunction with the drawing.
BRIEF DESCRIPTION OF THE DRAWING
The single FIGURE of the drawing is a cross-sectional view of an exemplary embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Turning now to the drawing, there is shown a cylindrical workpiece 1, for example a bolt, a piston wrist pin or even a needle of a needle bearing which is held between two transport rollers 2 and 3 that are arranged to rotate in the same direction. The rotation of the transport rollers 2 and 3 imparts to the workpiece 1 a centerless rotation. The transport of the workpiece 1 in the direction parallel to its own rotational axis, i.e. perpendicular to the plane of the figure, is due to the mutual inclination of the rotational axes 5 and 6 of transport rollers 2 and 3, respectively. Thus, in addition to the rotation, the workpiece 1 also has a motion component in the direction of the axis 4.
Riding on the workpiece 1 is a honing tool 7 which is pressed against the rotating workpiece 1 with a predetermined amount of pressure. The honing tool 7 is held in a honing tool holder 8 which includes a suitable mechanism, for example a cylinder 10 and a piston 9 which, together, urge the honing tool against the rotating workpiece 1. An oscillating head 11 serves to impart to the honing tool holder 8 and to the honing tool 7 an oscillatory motion of a few millimeters amplitude in a plane parallel to the rotational axis 4. The oscillating head 11 and the honing tool holder 8 are fastened on a machine frame (not shown). An oscillating head 11 which may be suitably employed is described in U.S. Pat. No. 2,716,392.
The honing process described above is a so-called super-finishing process, i.e. the exterior surfaces of cylindrical workpieces are continuously ground and honed in a centerless manner.
The contact area between the honing tool 7 and the rotating workpiece 1 is suffused with a flushing liquid, for example honing oil, a petroleum derivative, suitable mixtures of oils or other suitable fluids. However, as has been mentioned previously, it is difficult to keep the whole interface contact area 12 between the honing tool 7 and the cylindrical workpiece 1 clean continuously. The honing tool 7, which comprises abrasive grains held in a binding material, and which causes the removal of material from the cylindrical workpiece 1, is itself subject to a certain amount of wear. This wear is manifested in that the abrasive grains held in the binding material become dull and are broken out of the binding material, possibly taking with them some of the binding material. During the honing process, the contact surface 12 of the honing tool 7 conforms very precisely to the cylindrical outer surface of the workpiece 1. The material removed from the honing tool 7, as well as the material removed by the honing tool from the workpiece 1 is in the form of an extremely fine powder which has the tendency to contaminate or clog the contact surface of the honing tool, i.e. to make it dull. Even when flushing liquids are used in known manner, these powdered materials are not entirely carried away from the contact area 12 by the rotating workpiece due to the exact mating of the contact area 12 and the outer surface of the workpiece 1. As a result, the powdered material remains attached to the contact surface 12, of the honing tool especially in voids between the individual abrasive grains, so that the dulled abrasive grains can no longer break out of the binding material. Accordingly, the rate of material removal from the workpiece 1 decreases. This deterioration occurs very rapidly; it can become noticeable after the processing of a few dozen workpieces.
On the other hand, to make matters even worse, the slightest grinding irregularity may cause an effective resharpening of the honing tool, i.e. a king of "dressing", which leads to a renewed and increased material removal from the workpiece. This irregularity may be due, for example, to the abrupt transition from one workpiece to another when two endwise adjacent workpieces pass underneath the honing tool. The protruding edge of a workpiece entering beneath the honing tool 7 leads to the above mentioned dressing and thus causes a newly increased material removal rate. Thus, when several workpieces are processed, the final dimensions are subject to considerable variations leading to wide machining tolerances, which it is the purpose of fine machining to prevent. The same effect can occur when the honing tool is lifted from the work temporarily and then makes renewed contact with the work. The soiling, i.e. clogging which is the cause of these fluctuations in the final dimensions of the work can not be eliminated even by an intensive flushing with flushing liquid due to the very tight fit and the large area of contact between the contact surface 12 and the outer surface of the workpiece 1. The exemplary embodiment shown in the figure provides that the contact surface 12 which engages the workpiece 1 lies below the level 13 of the flushing liquid. This purpose is achieved by providing a container substantially parallel to the longitudinal extent of the transport rollers; this container is formed by lateral plates 14 and 15 to which are attached flexible side members 18 and 19, for example with the aid of fastening screws 16 and 17. The side members 18,19 may be made of rubber or flexible plastic and as shown, their lower edges 20,21 are in wiping contact with the outer surfaces of the rollers 5 and 6. The lower part of the container is formed by plates 22 and 23 which also have flexible side members 24,25 whose upper edges 26,27 make wiping contact with the circumference of the transport rollers 5,6. The ends of the container (not shown in the figure) are formed by additional flexible members, for example by elastic foils, etc., thereby creating a container whose volume is defined by the members 18,19,24,25, as well as by the side plates 14,15,22,23 and which is filled with flushing liquid 28 up to the level 13.
Mounted on the top of the container and partially extending below the level 13 of the flushing liquid 28 is an ultrasonic generator 29. Its transmission head 30, which lies below the level 13, directs ultrasonic waves in the direction of the honing tool 7 as is indicated by the wavy lines 31. These ultrasonic waves impart a high frequency oscillation to the honing tool, corresponding to the ultrasonic frequency, which occurs transversely to the longitudinal axis of the workpiece 1, i.e. transversely to the swinging oscillation provided by the oscillator head 11. This extremely low amplitude oscillation at ultrasonic frequency loosens the powdered material removed from the honing tool or from the workpiece which adheres to the contact surface 12. This loosening enhances the entrainment and removal of this material by the flushing liquid. The flushing liquid 28 thus transmits the ultrasonic oscillations from the transmitter head 30 of the ultrasonic generator 29 to the honing tool 7, and also directly to the clogging matter adhering to the contact surface 12.
The ultrasonic oscillation of the honing tool 7 takes place transversely to its main, swinging oscillation, which is parallel to the rotational axis of the workpiece. The ultrasonic oscillations may have a relatively high frequency, for instance, approximately 20,000 Hz, and an extremely small amplitude (a few 100ths of a millimeter). This oscillation becomes fully developed only in the vicinity of the end of the honing tool nearest the contact surface 12, so that any feedback effects on the other machine members, especially on the honing tool holder or the machine frame are negligibly small.
The container which is formed by the side plates 14,15, 22,23 and by the flexible side members 18,19,24,25, as well as by appropriate end plates and flexible end members contains the flushing liquid 28 up to a level 13. This container is surrounded by a further, outer container 32 which collects any flushing liquid which penetrates through the opening between the transport rollers 2,3 and the flexible side members 18,19, 24,25. This leakage liquid is pumped back to the inner container through a drain 33, possibly through a filter (not shown), and a line 34, terminating at an inlet 35 of the outer container which holds liquid up to the level 13. The ultrasonic generator 29,30 is so embodied that there is a substantially uniform transmission of ultrasonic energy to the lateral surfaces 36,37 of the honing tool 7. If necessary, several ultrasonic generators may be provided and, if required, they may be located on both sides of the honing tool 7.
In a variant embodiment of the invention, the plates 22,23 and the side members 24,25 fastened thereto may be omitted because, when completely cylindrical parts, such as, for example wrist pins, are being processed, very little liquid passes between workpiece 1 and the transport rollers 2,3. In that case, it is sufficient to provide flexible members at the ends of the transport rollers. Under this condition, the container described above is then formed only by the elements designated 14,15,18 and 19. In that instance, it is possible also to dispense with pumping back leaked flushing liquid and it is only necessary to compensate for the loss of flushing liquid through the opening 35. Any other suitable method for maintaining the level 13 may be employed.
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The honing tool in a centerless honing apparatus is held in an oscillating head and is pressed against the workpiece transported by rotating rollers. The region of contact between the honing tool and the workpiece is immersed in a flushing liquid which serves to dislodge and remove abraded material from the contact surface of the honing tool. An ultrasonic generator is located near the honing tool and its transducer portion extends into the flushing liquid. The ultrasonic vibrations are transmitted by the flushing liquid to the honing tool, imparting thereto ultrasonic oscillations in a direction transverse to the rotational axis of the workpiece. The liquid also transmits ultrasonic vibrations directly to the contact area and to the embedded abraded material, thereby loosening it and permitting entrainment by the flushing liquid.
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BACKGROUND OF THE INVENTION
Even today, waste products of relatively easily degradeable plastics, such as polyurethanes, polyesters, polycarbonates and polyamides are still burned or dumped. Economically and ecologically, however, it would be much more desirable to degrade these hydrolytically degradeable polymers into their starting components which could then be reused for the production of plastics.
It is known that, for example, polyurethane foam waste can be degraded into its low molecular weight starting compounds at elevated temperature and pressure (for example 40 bars and 240° C) in a stirrer-equipped autoclave, the polyisocyanate originally used in the synthesis of the polyurethane foam being hydrolyzed into the corresponding polyamine. The complete hydrolytic degradation of polyurethane foam waste under the conditions specified in such an autoclave would take about one hour. Any process of this kind, however, is only of economic and commercial interest if it can be carried out continuously.
Processes for hydrolyzing polyurethane foam waste are known and are described, for example, in German Offenlengungsschrifts Nos. 2,362,919; 2,362,920 and 2,362,921. According to the last of these Offenlegungsschrifts, hydrolysis is carried out in batches in a closed reaction zone whereas according to Offenlegungsschrifts Nos. 2,362,919 and 2,362,920 hydrolysis is carried out continuously (a) in a fluidized bed and (b) in a defined, tubular reaction zone, respectively. Unfortunately, these process are attended by a number of disadvantages.
Thus, the entire fluidizing gas must be heated to the reaction temperature (250°-400° C) in the reactor and subsequently cooled again in order to condense the diamine. Vast quantities of energy are necessarily wasted. Additionally, the reaction zone used to carry out hydrolysis has to be extremely large because the already extremely voluminous foam takes up even more space as a result of fluidization. Additionally, hot, unhydrolyzed and partially hydrolyzed foam particles have a marked tendency to stick together. The reaction zone which is not continuously scraped by suitable means very soon becomes blocked up. Finally, the individual foam particles are surrounded by a coating of hydrolysis product. Unfortunately little or no reaction takes place inside them since no shear forces act upon the particles.
DESCRIPTION OF THE DRAWINGS
FIG. 1 represents pressure-time and temperature time graphs of the process of the instant invention.
FIG. 2 represents one type of screw machine useable in practicing the instant invention.
DESCRIPTION OF THE INVENTION
It has now been found that a variety of different hydrolytically degradeable waste plastics can be degraded into their starting compounds very easily, economically, continuously and in a controlled manner by means of a specially equipped screw machine.
Accordingly, the present invention relates to a process for the continuous hydrolytic degradation of waste plastics comprising introducing waste of hydrolyzable plastics material together with water and, optionally, hydrolysis catalysts into a screw machine where the mixture of water and plastic waste is exposed to a temperature of 100 to 300° C and a pressure of 5 to 100 bars for 2 to 100 minutes in a reaction zone, accompanied by intensive mass and heat exchange. The liquid-gas mixture formed during hydrolysis is continuously introduced into a nozzle which is connected to the screw machine and from which the gas leaves through a regulating valve maintaining the constant screw-machine pressure in the nozzle, and the liquid leaves through a regulating valve maintaining a constant liquid level in the nozzle.
The invention also relates to a screw machine for carrying out the process of the invention. The screw machine consists of:
a. a tubular housing having
1. an air vent means,
2. a water inlet means,
3. a material feed hopper means located between said vent means and said inlet means, and
4. a material outlet nozzle provided with
i. a presssure measuring and regulating means,
and
ii. a liquid level measuring and regulating means,
b. a screw shaft arranged in said housing, said screw shaft comprising
1. a first screw threaded section of high pitch extending beyond said feed hopper means in the direction of flow,
2. adjacant to said first section, a second screwthreaded section of lower pitch than said first section, and
3. adjacent to said second section, kneading discs fitted to said screw shaft, said water inlet means opening into said second section.
In general, the first section (b) (1) has a pitch of more than 90 mm and preferably more than 100 mm. The second section (b) (2) has a pitch of less than 70 mm, preferably less than 60 mm, and most preferably less than 45 mm. (These figures refer to a double-thread screw with a diameter of 90 mm; for other dimensions of the screw the pitches have to be varied accordingly).
The following individual steps take place in succession or simultaneously in the process according to the invention:
1. Continuous delivery and venting of the plastic waste;
2. Continuous delivery of water;
3. Pressure buildup in the plastic/water mixture to approximately 5-100 bars, preferably 10-80 bars and, most preferably 30-50 bars;
4. Temperature buildup in the plastic/water mixture to approximately 100°-300° C, preferably 150°-270° C and, most preferably to 200°-250° C;
5. intensive mass exchange in which hydrolytic degradation takes place in about 2 to 100 minutes, preferably in 5 to 100 minutes and, most preferably in 10 to 40 minutes;
6. Relieving the hydrolysis products of pressure (in the case of a foam of polyether and tolylene diisocyante: polyether, tolylene diamine, CO 2 and water) to 0 bar;
7. Discharging the gaseous hydrolysis products;
8. Cooling the liquid hydrolysis products to approximately 50 to 100° C;
9. continuous delivery of the liquid hydrolysis products to a separation means;
10. Separation of the hydrolysis products, for example by washing, extraction or distillation.
The process described above may be followed schematically from the pressure-time and temperature-time graphs shown in FIG. 1:
The graph shows the variation of the temperature and pressure to which the material to be hydrolyzed is exposed during the process of the invention as a function of time. After the plastic waste and water has been introduced and vented[zone (1) in FIG. 1], pressure and temperature are built up[zone c2)]. The material is then hydrolytically degraded[zone (3)]. After the hydrolysis products have been relieved of pressure to 0[zone (4)], they are cooled and discharged[zone (5)].
It is generally difficult to buildup the pressure in the plastic/water mixture to the high pressures required. This is particularly true when it is recognized that their buildup must be accompanied by venting, an intensive mass and heat exchange in the reaction zone for about 30 minutes with a narrow residence-time spectrum in a low-viscosity liquid mixture and the formation of a gas from a solid. Additionally, the pressure must be maintained while at the same time the liquid-gas mixture must be continuously discharged from the reaction zone.
One particularly suitable arrangement for carrying out these process steps is a screw machine which is equipped as illustrated in FIG. 2.
After size reduction, the plastic is introduced into the screw machine through a material feed hopper means (1). Air can escape against the flow direction before the feed hopper through an air vent means (2) in the tubular housing. A gentle vacuum may be applied if desired. Just after the hopper (looking in the flow direction), water is introduced into the screw machine (preferably by a nozzle) through a water inlet means (3) in the housing.
The threading of the screw shaft is divided into different zones: a thread of high pitch [feed thread c4) approximately 15% of the overall length of the screw] is used in the first part of the screw machine, extending to a point just beyond the feed hopper (1). A low-pitch thread is then used for compressing the plastics material (pressure buildup-thread (5), approximately 15% of the overall length of the screw). After the pressure buildup-thread, kneading discs (6) are pushed onto the rest of the screw shaft (approximately 70% of the overall length of the screw).
The entire screw housing (7) is provided with a heat-exchange system[cooling c8) and heating c9)]. At the exit area of the screw housing, from which the screw shaft projects to a certain extent, is screwed a special nozzle (10). This nozzle is provided with both a pressure and liquid level gauge. Additionally, the nozzle has pipe connections at the top and bottom thereof. A liquid-gas mixture enters the nozzle and the liquid portion issues through the down pipe (11), a constant liquid level being maintained by the regulator (12). The gas leaves the nozzle through the upwardly extending pipe (13), a constant pressure being maintained in the nozzle (and hence in the reaction zone) by the regulator (14). The liquid hydrolysis products are delivered continuously into a cyclone separator (16) provided with a cooling system (15), from which both the gas phase (18) formed during pressure release and the liquid phase (17) can be run off. Following phase separation into an organic phase and, optionally, an aqueous phase, the organic phase can be separated into its components in known manner (for example by distillation, extraction with acids or bases, and the like).
The pressure and liquid level regulating means useable are of a type generally known in the art, and need not be described herein.
In order to obtain a high throughput during the necessary relatively long residence time in the reaction zone (about 30 minutes), the screw should be of large volume, i.e. should be low-cut. A narrow residence-time spectrum is best obtained by using a screw machine with double screws rotating in the same direction.
In order to accelerate the hydrolysis reaction, it is also possible to add to the water introduced into the screw machine, either acid or basic hydrolysis catalysts (depending upon the type of plastics), preferably those which can readily be removed from the hydrolysis products by neutralization and washing (for example aqueous mineral acids or aqueous alkali and alkaline earth hydroxide solutions).
As already mentioned, the process according to the invention may be applied in principle to any hydrolytically degradeable plastics, i.e. for example to polyesters, polycarbonates, polyamides and polyurethanes. However, the process according to the invention is preferably used for degrading waste based on polyurethanes synthesized from polyethers and polyisocyanates, because the hydrolysis products formed in that case can be separated particularly easily and directly used for processing.
EXAMPLE
The machine used for the Example (Werner & Pfleiderer's type ZDS- KG 90) comprises two screws rotating in the same direction at a speed of 120 rpm having a shaft diameter of 90 mm, a length of 2200 mm and a volume of 8.2 liters. The nozzle has a volume of approximately 0.5 liter, the throughput amounting to 25 kg/h for a residence time in the screw of approximately 20 minutes.
The pitch of the screw thread in the 650 mm long feed zone is 120 mm (double-thread), and in the 650 mm long pressure-buildup zone 60 mm (double-thread). The adjoining reaction zone consists of a 1300 mm long kneading zone with kneading blocks, followed by a threaded zone with a pitch of 60 mm (double-thread).
A. Production of the polyurethane foam
100 parts by weight of an NCO prepolymer having an NCO content of 8.2% by weight, obtained from 100 parts by weight of a linear polypropylene glycol (OH-number 56) and 34.7 parts by weight of tolylene diisocyanate (65% of 2,4-isomer and 35% of 2,6-isomer),
3 parts by weight of ethyl morpholine,
1.8 parts by weight of water,
0.5 parts by weight of diethyl amine oleate and
1.0 parts by weight of polydimethyl siloxane
were intensively mixed in a high speed stirrer. The product was then heated for 2 hours at 100° C. A soft-elastic foam having a density of 50 kg/m 3 was formed.
B. Process according to the invention
100 parts of the size-reduced polyurethane foam and 20 parts of water were continuously introduced into the machine described above which was equipped as illustrated in FIG. 2 (throughput: 25 kg/h). CO 2 and H 2 O as gas phase, and a mixture of polyether, tolylene diamine and water as liquid phase, were continuously removed from the nozzle. The liquid phase could readily be separated into its components by extraction with dilute aqueous hydrochloric acid.
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The instant invention relates to a continuous process for the hydrolytic degradation of plastics wherein a hydrolyzable material is introduced with water into a screw machine, and is subjected therein to a temperature of 100 to 300° C, and a pressure of 5 to 100 bars for 2 to 100 minutes. The invention also relates to an apparatus useful in conducting the process.
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RELATED APPLICATION DATA
[0001] This application is a divisional of copending U.S. patent application Ser. No. 10/835,715, filed Apr. 30, 2004, which claims priority to Provisional Application Ser. No. 60/466,949, filed May 2, 2003, both of which are incorporated herein by reference.
FIELD OF INVENTION
[0002] The present invention relates generally to fence covering systems, and in particular, to an apparatus and method for mounting onto and covering at least one side of existing or new fences.
SUMMARY OF INVENTION
[0003] A fence covering system includes a split portion post and a panel configured and dimensioned to cover a portion of an existing fence. The panel is connected to a frame to provide a visual effect. A connector secures the post on a portion of the fence, the connector providing an attachment position for the post.
[0004] Alternatively, a second panel may be used to cover the opposite side of a fence in addition to he first panel. Another panel may be attached to the first panel at the top, with both panels being received at their edges by a recess in the post.
[0005] Further, the fence covering system according to the present invention is easily removable, so that alternate designs and configurations may be freely interchanged and installed as desired. Advantageously, the present invention may be adapted to be used with virtually any type of fence or fence frame, and is not limited to use with, e.g., chain-link fences.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] This disclosure will present in detail the following description of preferred embodiments with reference to the following figures wherein:
[0007] FIG. 1A is an exploded perspective view showing a panel frame and panel in accordance with one embodiment of the present invention;
[0008] FIG. 1B is an assembled perspective view showing a panel frame and panel in accordance with an embodiment of the present invention;
[0009] FIG. 2A-G are perspective views showing panel frames being assembled on a chain link fence in accordance with different embodiments of the present invention;
[0010] FIG. 3 is an assembled perspective view showing a panel frame with additional height in accordance with an embodiment of the present invention;
[0011] FIG. 4A is a perspective view showing panel frames cascaded in accordance with an embodiment of the present invention;
[0012] FIGS. 4B and 4D are perspective views showing adjustable mounting plates in accordance with an embodiment of the present invention;
[0013] FIG. 4C is a perspective view showing a panel frame mounted on a chain link fence in accordance with an embodiment of the present invention;
[0014] FIG. 4E is a perspective view showing mounting plates secured to poles of a fence in accordance with one embodiment of the present invention;
[0015] FIGS. 5A-C are perspective views showing adjustable pole covers and ornamental poles used in accordance with an embodiment of the present invention;
[0016] FIGS. 6A-6L are perspective views showing a plurality of different assemblies to be employed in accordance with embodiments of the present invention;
[0017] FIGS. 7A-7C are perspective views showing hardware employed on gates in accordance with embodiments of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0018] FIGS. 1A and 1B depict an exemplary fence covering panel 100 according to an aspect of the present invention. Preferably, the fence covering panel 100 is constructed of a rigid but somewhat flexible and resilient material, e.g., aluminum, vinyl, plastic, etc. In one embodiment, the present invention is generally comprised of at least one panel frame 102 having an interior panel 104 fitted therein which may include, e.g., optional openings/perforations 106 , etc. It is to be noted that the interior panel 104 may include, for example, various graphics (e.g., “artwork”) on its outer face. In addition, the interior panel 104 may be constructed in various configurations and designs (e.g., picket or slot designs 108 ).
[0019] FIGS. 2A-2G show various alternative embodiments wherein two of the fence covering panels 100 are combined to be fitted over both sides of a chain-link fence 200 . It is to be noted that the chain link fence 200 shown here is for exemplary purposes only and use of the present invention with other types of fences may be contemplated.
[0020] In one embodiment, each covering panel 100 is placed over either side of the fence 200 and then joined to each other at, for example, a top end via, e.g., snaps, screws, bolts, etc. (not shown). In another embodiment, as shown e.g., in FIGS. 2B and 2C , one or more pairs of mounting plates 202 are first installed and fixed onto the fence 200 or a top fence bar 201 via, e.g., snaps, screws, etc. At least one of the pair of mounting plates 202 may include, for example, protrusions 204 shaped to at least fit through, for example, links of the chain-link fence 200 , and be mated with appropriately shaped receiving cavities (not shown) on a corresponding mounting plate 202 on the other side of the fence (see FIG. 2D ). Alternatively, at least one of a pair of mounting plates 202 may be adapted for attachment on the top fence bar 201 (e.g., may have a hollow cavity formed therein shaped to receive a portion of the top fence bar 201 ) and then be attached to a corresponding mounting plate 202 on the other side of the top fence bar 201 . In these ways, for example, each mounting plate 202 may be snapped into place and secured onto the fence 200 as well as be secured to each other.
[0021] In yet another alternate embodiment, it is to be noted that each covering panel 100 may include attachment points for attachment of various mounting plates 206 thereon as desired (e.g., plates mounting over fence bar 201 or through the chain-link fence 200 ) that are removable and independently interchangeable as desired (see FIG. 2E ).
[0022] Next, each covering panel 100 can then be attached to the fence 200 via each installed mounting plate 202 . For example, each covering panel 100 may be snapped, screwed onto, or otherwise fastened onto each mounting plate 202 . The mounting plates 202 also serve to ensure and simplify correct alignment of each covering panel 100 with each other and with respect to the fence 200 prior to installation of each covering panel 100 .
[0023] In yet another embodiment, each covering panel 100 is first attached to each other at a top end (via, e.g., screws, snaps, etc.) and then slidably installed over the fence 200 (see FIG. 2F ). FIG. 2G shows a segment of two fence covering panels 100 according to the present invention as installed on, for example, both sides of the chain-link fence 200 . It is to be noted that each of the fence covering panels 100 may include a fastening means (not shown) to secure the panels 100 to the fence 200 . Such fastening means may comprise, e.g., a clip to secure the bottom of each panel 100 to the bottom of the fence 200 . Alternately, two covering panels are integrally formed to provide a single piece, which can be fitted over the top of a fence 200 . The two panels may be hingedly connected to fit over the fence and be attached to or through the fence at a lower portion.
[0024] FIG. 3 depicts an exemplary embodiment of the fence covering panel 100 having an optional extended detailing feature 300 according to an aspect of the present invention. The detailing 300 may comprise, e.g., railings, posts, arches, walls, etc. in any shape, size or configuration to extend the height of the overall fence as desired.
[0025] FIGS. 4A and 4B show exemplary arrangements wherein multiple fence covering panels 100 are installed on either sides of the fence 200 as well as adjacent to each other along the fence 200 . It is to be noted that the fence covering panels 100 may include, e.g., interlocking/mating features (not shown) for side-by-side attachment to each other when they are adjacently installed.
[0026] The installation of the panels 100 onto the fence 200 may be accomplished using, e.g., individual mounting plates 202 as described above or upper and lower adjustable mounting plates 400 and 401 , respectively. The upper and lower adjustable mounting plates 400 and 401 may be, for example, slideable to provide for adjustment of their length as desired along each side of the fence 202 (see FIG. 4B ). Thus, in an alternate embodiment as shown in FIG. 4C , a single extended fence covering system 402 may be installed onto the fence 200 on appropriately extended adjustable mounting plates 400 and 401 (not shown).
[0027] In yet another alternate embodiment, FIG. 4D depicts installation of upper and lower adjustable mounting plates 400 and 401 on a standard fence frame comprising fence posts 404 and top fence bar 201 . It is to be noted that in this embodiment, the lower adjustable mounting plate 401 may be used alone without an additional bottom fence bar for reinforcement. FIG. 4E shows yet another embodiment wherein frame mounting plates 406 are installed onto the top fence bar 201 and a bottom fence bar 408 for mounting of the fence covering panels 100 .
[0028] Thus advantageously, it is to be noted that it is not required to construct an actual fence in its entirety for installation and attachment of a fence covering system according to the present invention. Instead, a simple fencing frame can provide sufficient structural support for installation, mounting and utilization of the present invention.
[0029] FIGS. 5A-5C show exemplary embodiments wherein a fence post covering system 500 is installed onto a fence 200 . It is to be noted that the fence post covering system 500 may be used to cover fence posts or fences of any type, and is not limited to chain-link fences. In one embodiment, the fence post covering system 500 is comprised of at least one fence post mounting plate 501 and at least one fence post covering panel 503 . It is to be noted that the mounting plate 501 may be adapted so as to be removably attachable to a fence post (see FIG. 5A ) or at any point along the fence (see FIG. 5B ). In another embodiment as shown in FIG. 5C , each fence post covering panel 503 includes removable mounting pieces 505 attached therein that are shaped/positioned accordingly for attachment of the panel 503 to the fence post 404 or to any point along the fence 200 .
[0030] FIGS. 6A-6L depict various embodiments of a combined fence and fence post covering system according to the present invention. It is to be noted that the fence and fence post covering system may be adapted for use on either one of both sides of the fence 200 as desired. Preferably, each of the components of the fence and fence post covering system is constructed of a rigid but somewhat flexible and resilient material, e.g., aluminum, vinyl, plastic, etc.
[0031] In FIG. 6A , a combination fence and fence post covering system 600 is shown comprising fence post coverings 503 , a side panel 601 and a cap 603 . The fence post coverings 503 may be attached to each fence post 404 via e.g., fence post mounting plates 501 or mounting pieces 505 , as described above. The side panel 601 is preferably cut and sized to fit between each post covering 503 and may be attached to the fence 200 by e.g., partially inserting/sliding each edge 602 of the panel 601 under/into each post covering 503 . The cap 603 is also preferably cut and sized to fit between the post coverings 503 and preferably has an interior cavity 604 appropriately sized/shaped to fit over and receive the top fence bar 201 . The cap 603 may be secured if desired to the fence bar 201 and/or to either or both of the fence covering posts 503 via any conventional means e.g., suction, snaps, clips, bolts, screws, etc.
[0032] Alternatively, the cap 603 may be attached to the fence bar 201 via mounting onto at least one cap mount 605 (see FIG. 6B ). Preferably, for optimal stability, at least two cap mounts 605 are used for mounting the cap 603 thereon. Each cap mount 605 may be attached to the fence bar 201 by any conventional means, e.g., screws, bolts, snaps, suction, etc.
[0033] In another embodiment as shown in FIG. 6C , a modified post mount 607 may be provided for attachment to a top end of the fence post 404 . Preferably, each post mount 607 is designed to secure at least one or, alternatively, both post coverings 503 on either side of the fence 200 , as well as the cap 603 to the fence 200 . The post mount 607 may be affixed to the post 404 via conventional means, e.g., bolts, pressure screws, snaps, etc. It is to be noted that the modified post mount 607 may be used in a similar fashion on a bottom end of the fence bar 404 .
[0034] It is to be noted that the side panel 601 may be comprised of individual panels 609 that are integrated (e.g., attached) to each other (see FIG. 6D ). The individual panels 609 may be pre-cut in various sizes/shapes and may each have identical or varying widths and dimensions. The individual panels 609 are preferably designed to fit together and include means for attaching to each other. For example, each panel 609 may be secured to each other by various conventional means, e.g., via snaps, by being slid into place and secured via interlocking mechanisms, etc. The individual panels 609 are removable/attachable to each other as desired to adjust the width of the overall side panel 601 . A lower bar panel 611 may also be added, for example, along the lower portion of the fence between each post covering 503 . The lower bar panel 611 may be secured to the fence 200 via snaps, screws, bolts, etc.
[0035] In another embodiment, the side panel 601 having the cap 603 and the lower bar panel 611 attached thereon may be provided as a single side panel unit 613 for ease of installation (see FIG. 6E ). The single side panel unit 613 may be mounted onto one or both sides of the fence 200 . In yet another embodiment, the single side panel unit 613 may be further combined with at least one post covering 503 to provide a combined panel and post unit 615 (see FIG. 6F ). The combined panel post unit 615 may include one or two post coverings 503 . It is to be noted that the side panel 601 , whether or not it is combined with the cap 603 , the lower bar panel 611 or the post covering 503 , may be constructed in various designs (e.g., cross-panels 617 (see FIG. 6G ), picket design, etc.) and/or further customized to include various graphics (e.g., as described above for the interior panel 104 ).
[0036] In an alternate embodiment, the combined panel and post unit 615 may be modified, e.g., to have a removable lower section 619 as well as a removable lower post covering 621 (see e.g., FIG. 6H ). It is to be noted that either the lower section 619 and/or the lower post covering 621 may be removed or added as desired. Preferably, the post covering 503 is attached at at least one point on the upper portion of the fence post 404 (see e.g., FIG. 6C ) via, e.g., post mount 501 , mounting pieces 505 or modified post mount 607 as described above, such that even if the lower post covering 621 is removed, the remaining portion of the post covering 503 is supported by and affixed to the fence post 404 (not shown).
[0037] In another embodiment as shown in FIG. 61 , extended post coverings 623 may be provided which extend upwards a desired height beyond the height of the fence 200 . An upper panel 621 may be added which fits between the extended post coverings 623 to extend the height of the fence 200 as desired. The upper panel 621 may be removably attached to the top of the cap 603 or to the top of the fence covering panel 100 , or be combined with the fence covering panel 100 as one unit. In addition, the extended post coverings 623 may optionally include attachment points (not shown) for securing each end of the upper panel 621 to the extended post coverings 623 .
[0038] In another embodiment as shown in FIG. 6J , a removable planter box 625 may be mounted between the extended posts 623 . The planter box 625 may be permanently affixed or integrally formed with the side panel 601 . It is to be noted that the planter box 625 may be affixed, for example, atop the cap 603 or directly atop the side panel 601 , and may further be secured to the extended posts 623 at each end. The extended posts 623 may further optionally include lamps 627 or other ornamental features attached, for example, at a top end.
[0039] Alternatively, the planter box 625 may be permanently/removably attached to the bottom end of the fence 200 between each post covering 503 (see e.g., FIG. 6K ). In this embodiment, the side panel 601 may include, for example, a removable panel 629 for providing pass-through of light through the fence 200 when the planter box 625 is used. It is to be noted that the side panel 601 may be comprised of openings, perforations, etc., in any configuration to also permit pass-through of light as desired.
[0040] A corner post covering 631 may be provided having slots 633 enabling the covering 631 to be slid into place over a fence corner post 635 (see FIG. 6L ). Alternatively, an extended version of the corner post covering 631 may be provided and the slots 633 may serve as receiving points on at least two adjacent sides of the corner post covering 631 for permitting attachment of, for example, the upper panels 621 (see FIG. 61 ). The slots 633 may comprise, e.g., openings sufficient for insertion of one end of the upper panel 621 and may include locking mechanisms to secure the upper panels 621 therein. Any other conventional means (e.g., snaps, bolts, etc.) for attachment of the upper panel 621 to the extended version of the corner post covering 631 may be contemplated.
[0041] FIGS. 7A-7C depict various embodiments of the present invention as adapted for fence gates. At a basic level, a gate side panel 701 , gate post coverings 703 and a gate cap 705 may be provided for covering a fence gate 700 . Alternatively, 701 , 703 and 705 may be provided as a combined single fence covering unit 707 (see FIG. 7B ). It is to be noted that the fence post covering 503 which covers a fence post adjacent to the opening point of the fence gate 700 may be modified to include, e.g., a slot 709 or other means for receiving a gate locking hinge or other locking/closing mechanism on the fence gate 700 .
[0042] Having described preferred embodiments for fence covering systems (which are intended to be illustrative and not limiting), it is noted that modifications and variations can be made by persons skilled in the art in light of the above teachings. It is therefore to be understood that changes may be made in the particular embodiments of the invention disclosed which are within the scope and spirit of the invention as outlined by the appended claims. Having thus described the invention with the details and particularity required by the patent laws, what is claimed and desired protected by Letters Patent is set forth in the appended claims.
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A fence covering system includes a frame configured and dimensioned to cover a portion of an existing fence. A panel is connected to the frame to provide a visual effect. A connector secures the frame on a portion of the fence, the connector providing an attachment position for the frame.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This is a continuation application of application Ser. No. 11/161,356, filed Aug. 1, 2005, which claims the benefit of U.S. Provisional Application No. 60/522,324, filed on Sep. 15, 2004, the contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to wireless communications. More particularly, the present invention relates to an enhanced polling mechanism and device in a 3GPP wireless communications system.
[0004] 2. Description of the Prior Art
[0005] The surge in public demand for wireless communication devices has placed pressure upon industry to develop increasingly sophisticated communications standards. The 3 rd Generation Partnership Project (3GPP™) is an example of such a new communications protocol. The 3rd Generation Partnership Project (3GPP) specification, 25.322 V6.1.0 (2004-06) Radio Link Control (RLC) protocol specification (referred to hereinafter as 3GPP TS 25.322), included herein by reference, provides a technical description of a Universal Mobile Telecommunications System (UMTS), and data transmission control protocols thereof.
[0006] These standards utilize a three-layer approach to communications. Please refer to FIG. 1 . FIG. 1 is a block diagram of three layers in such a communications protocol. In a typical wireless environment, a first station 10 is in wireless communications with one or more second stations 20 . An application 13 on the first station 10 composes a message 11 and has it delivered to the second station 20 by passing the message 11 to a layer-3 interface 12 . The layer-3 interface 12 may also generate some layer-3 signaling messages 14 for the purpose of controlling layer-3 operations. The layer-3 interface 12 delivers either the message 11 or the layer-3 signaling message 14 to a layer-2 interface 16 in the form of layer-2 service data units (SDUs) 15 . The layer-2 SDUs 15 may be of any length. The layer-2 interface 16 composes the SDUs 15 into one or more layer-2 protocol data unit(s) (PDU) 17 . Each layer-2 PDU 17 is of a fixed length, and is delivered to a layer-1 interface 18 . (The required length of PDUs within a given communications system is dictated by the RLC layer of a transmitting station in accordance with above cited reference.) The layer-1 interface 18 is the physical layer, transmitting data to the second station 20 . The transmitted data is received by the layer-1 interface 28 of the second station 20 and reconstructed into one or more PDUs 27 , which is/are passed up to the layer-2 interface 26 . The layer-2 interface 26 receives the PDUs 27 and builds up one or more layer-2 SDU(s) 25 from the PDUs 27 . The layer-2 SDUs 25 are passed up to the layer-3 interface 22 . The layer-3 interface 22 , in turn, converts the layer-2 SDUs 25 back into either a message 21 , which should be identical to the original message 11 that was generated by the application 13 on the first station 10 , or a layer-3 signaling message 24 , which should be identical to the original signaling message 14 generated by the layer-3 interface 12 , and which is then processed by the layer-3 interface 22 . The received message 21 is passed up to an application 23 on the second station 20 . (As a note regarding terminology used throughout this disclosure, a PDU is a data unit that is used by a layer internally to transmit to, and/or receive from, a lower layer, whereas an SDU is a data unit that is passed up to, and/or received from, an upper layer.)
[0007] There are three possible data transmission modes falling under the auspices of the abovementioned protocol specification, transparent mode (TM), acknowledged mode (AM) and unacknowledged mode (UM). As the present invention relates only to AM transmission, the scope of the prior art discussion herein is therefore limited to background relevant to AM transmission.
[0008] Acknowledged Mode transmission is so called because a transmitting station requires acknowledgement from a receiving station, confirming that a message or part of a message has been successfully received. Based upon such information returned from the receiving station, the transmitting station either continues to transmit further packetized data as described above, or retransmits unconfirmed portions of previously transmitted data. The extra effort required to employ this transmission mode carries an additional overhead in terms of transmission airtime and system requirements. The RLC layer of the transmitting station therefore minimizes the impact of the above-mentioned overhead. This is managed by carefully controlling the number of requests made to the receiving station for confirmation messages, i.e. status reports. Status reports are requested, or ‘polled’, by the transmitting station setting a poll bit in the header of a protocol data unit (PDU) to be transmitted. Please refer to FIG. 2 . FIG. 2 is a block diagram showing the make-up of an acknowledged mode data (AMD) PDU 30 . The AMD PDU 30 comprises a predefined number of octets, i.e. 8-bit binary words, as each AMD PDU within a given communications system is of a fixed length as mentioned above. The first octet 31 of the AMD PDU 30 is composed of a data/control (D/C) bit 310 , this being used to indicate the PDU type, i.e. either ‘data’ or ‘control’, and the first seven bits of the twelve-bit PDU sequence number (SN) 311 . The second octet 32 , is composed of five further bits of the SN 320 , the poll bit 321 , and the header extension (HE) bits 322 . The twelve-bit SN is used by receiving stations to accurately re-construct original messages from received PDUs, while the HE bits (there are two) are used to indicate whether the following octet, i.e. the third octet 33 , is a data byte or a length indicator (LI) with extension bit. In the example AMD PDU 30 shown, the third octet 33 is an LI 330 with an extension bit 331 ; the LI 330 is used to map the position within the PDU 30 of the last byte of an SDU contained in the data block 35 . More than one LI may be included in an AMD PDU, therefore the extension bit 331 , is included to indicate whether the following octet is a data byte or another LI with extension bit. Hence there may be a number of LIs between the first LI 330 and the last LI 340 . Because each PDU must conform to a predefined length, the PDU 30 may not be foreshortened even if there is insufficient data 35 to completely fill the required number of octets, hence padding 36 is inserted into the remaining octets.
[0009] Of particular relevance is the poll bit 321 , which is used to prompt the receiving station to reply with a status report upon successful receipt of any PDU in which the poll bit is set. Please refer to FIG. 3 , which shows a message sequence chart representing AMD PDU transfer between a transmitting station 41 and a receiving station 42 , in a communications system 40 utilizing a 3-layer protocol as outlined above. A string of PDUs 400 ˜ 405 are transmitted sequentially from the transmitting station 41 to the receiving station 42 , the last PDU 405 being sent with poll bit set. Upon receiving the PDU 405 , the receiving station 42 responds by transmitting a status report 406 back to the transmitting station 41 .
[0010] The designation of PDUs to be transmitted with poll bit set, is derived from the upper layers of each RLC entity in accordance with the cited protocol specification. The communications systems discussed herein can be configured to trigger a poll when any of the following events occur:
[0011] 1) The last PDU in the (first time) transmission buffer is transmitted.
[0012] 2) The last PDU in the re-transmission buffer is transmitted.
[0013] 3) Upon time-out of a ‘Poll_Timer’ function (triggers a poll function when a predefined period of time has elapsed following the initiation of a poll being sent out).
[0014] 4) An ‘Every Poll_PDU’ PDU is transmitted (triggers a poll function each time a predefined number of PDUs have been scheduled for transmission or retransmission).
[0015] 5) An ‘Every Poll_SDU’ SDU is transmitted (triggers a poll function each time a predefined number of SDUs have been scheduled for transmission).
[0016] 6) Conditions required by the ‘Poll_Window’ function are fulfilled (i.e. a “Window based trigger” is issued, which triggers a poll function when a predefined percentage of a transmission window has been reached).
[0017] 7) A predefined time period expires, i.e. a “timer based” function is configured (triggers a poll periodically).
[0018] In addition to the above, the upper layers may configure a timer called ‘Timer_Poll_Prohibit’, which is then used to prohibit the transmission of polls within a predetermined period. If another poll is triggered while polling is prohibited by a current Timer_Poll_Prohibit function, transmission of the poll is delayed until Timer_Poll_Prohibit expires. Even if several polls were triggered while Timer_Poll_Prohibit was active, only one poll is transmitted when Timer_Poll_Prohibit expires.
[0019] The polling process of the prior art set forth by 3GPP TS 25.322 can be summarized as the flow diagram shown in FIG. 4 :
[0020] Step 1000 : Process starts.
[0021] Step 1001 : The system checks if there is a new PDU to be transmitted. If there is, the process proceeds to Step 1010 . Otherwise, the process proceeds to Step 1002 .
[0022] Step 1002 : The system checks if there is negatively acknowledged PDU to be retransmitted. If there is, the process proceeds to Step 1011 . Otherwise, the process proceeds to Step 1003 .
[0023] Step 1003 : The system checks if a polling function has been triggered. If yes, the process proceeds to Step 1004 . Otherwise, the process terminates via Step 1017 .
[0024] Step 1004 : The system checks if polling is prohibited. If polling is not prohibited, the process proceeds to Step 1005 . Otherwise, the process terminates via Step 1017 .
[0025] Step 1005 : A polling function is activated and the polling bit of the next PDU to be transmitted is set to 1.
[0026] Step 1006 : The system checks if there is no PDU scheduled for transmission or retransmission. If the checking result is yes, the process proceeds to Step 1007 . Otherwise, the process terminates via Step 1017 .
[0027] Step 1007 : The system checks if the polling function checked at Step 1003 was triggered by “Poll timer” or “Timer based”. If yes, the process proceeds to Step 1008 . Otherwise, the process terminates via Step 1017 .
[0028] Step 1008 : The system selects a suitable PDU for retransmission to carry the poll.
[0029] Step 1009 : The system schedules the selected PDU for transmission. The process proceeds to Step 1016 .
[0030] Step 1010 : The system schedules the new PDU for transmission. The process proceeds to Step 1012 .
[0031] Step 1011 : The system schedules the negatively acknowledged (NACKed) PDU for retransmission.
[0032] Step 1012 : The system checks if a polling function has been triggered. If yes, the process proceeds to Step 1013 . Otherwise, the process proceeds to Step 1015 .
[0033] Step 1013 : The system checks if polling is prohibited. If polling is prohibited, the process proceeds to Step 1015 . Otherwise, the process proceeds to Step 1014 .
[0034] Step 1014 : A polling function is activated and the polling bit of the next PDU to be transmitted is set to 1.
[0035] Step 1015 : Polling function is not activated and the polling bit of the next PDU to be transmitted is set to 0.
[0036] Step 1016 : The system submits the PDU to lower layer for transmission.
[0037] Step 1017 : Process ends.
[0038] Please refer to FIG. 5 , which illustrates the above features via a similar message sequence chart to FIG. 3 , and retaining like index numbers where appropriate. Assume that transmitting station configuration is determined by upper RLC layers such that the following five poll triggers are enabled:
[0039] (1) “Last PDU in buffer (for first time transmission)”;
[0040] (2) “Last PDU in Retransmission buffer”;
[0041] (3) “Poll timer” (with Timer_Poll=200 ms);
[0042] (4) “Every Poll_PDU PDU” (with Poll_PDU=4); and
[0043] (5) “Every Poll_SDU SDU” (with Poll_SDU=4).
[0044] Assume also that the ‘Window based’ trigger and ‘Timer based’ trigger are disabled, that the poll prohibit function is configured with Timer_Poll_Prohibit=250 ms, that one SDU is requested for transmission by an upper layer and an RLC transmission confirmation is requested by the upper layer when transmission of the SDU is positively acknowledged, and that the SDU is segmented into six PDUs.
[0045] The transmitting station 41 will transmit the six PDUs 400 ˜ 405 (having sequential SNs: 0, 1, 2, 3, 4 and 5 for example) in sequence. When scheduling the fourth PDU 403 (SN=3) for transmission, the “Every Poll_PDU PDU” poll trigger will be activated and poll bit of the fourth PDU consequently set. The Timer_Poll 45 (200 ms) and Timer_Poll_Prohibit 43 (250 ms) functions are commenced simultaneously when PDU 403 (SN=3) is transmitted via lower layers. The transmitter continues to schedule the fifth (SN=4) and sixth (SN=5) PDUs, 404 & 405 respectively, for transmission. When PDU 405 (SN=5) is transmitted, the “Last PDU in buffer” trigger is activated since there are no more PDUs to be transmitted, however, the poll trigger 48 is delayed because the poll prohibit function (Timer_Poll_Prohibit), according to the prior art, is still in effect, hence the sixth and last PDU 405 is transmitted without its poll bit set. Suppose that the third PDU 402 (SN=2) is lost during radio transmission. When the receiving station receives the fourth PDU (which has its poll bit set), the receiving station accordingly transmits a status report 406 , in this case to positively acknowledge that PDUs having SN values 0, 1 and 3, i.e. PDUs 400 , 401 and 403 have been received successfully, but negatively acknowledging PDU 402 (SN=2). Suppose that the status report 406 is lost during radio transmission.
[0046] At a time 46 , the Timer_Poll function 45 completes its countdown, however, because Timer_Poll_Prohibit 43 is still active, a poll trigger 49 that would otherwise be issued by the Timer_Poll function 45 is also delayed. When Timer_Poll_Prohibit 43 expires at a time 44 , even though there are two active delayed poll triggers ( 48 and 49 ), only one poll is issued and sent with a PDU 402 a , which is a re-transmission of a selected PDU 400 (SN=0) that has not yet been acknowledged yet (because the status report is lost). Upon receiving the PDU 402 a , the receiving station 42 responds by transmitting a status report 407 to the transmitting station 41 to positively acknowledge PDUs having SN 0, 1, 3, 4 and 5 and to negatively acknowledge PDU having SN 2. The prior art method can then retransmit the PDU 402 (SN=2) with its poll bit set (not shown in FIG. 5 ) and proceed smoothly in this case.
[0047] In FIG. 5 , wherein there were no negatively acknowledged PDUs nor further SDUs requiring transmission and polling is not prohibited after Timer_Poll_Prohibit expires, the ‘timer based’ initiated poll would be sent with a re-transmission of a suitable PDU as described in Steps 1008 , 1009 and 1016 in FIG. 4 . The suitable PDU can be a PDU with SN=VT(S)−1, i.e. the sequentially last PDU that had been transmitted at least once (for example, PDU 405 in FIG. 5 ). VT(S) is a ‘send state’ variable that is maintained by the transmitting station; it is incremented (by one) each time a PDU is transmitted for the first time, however, it is not incremented if a PDU is re-transmitted.
[0048] In addition to the SN=VT(S)−1 PDU, in cases where “Configured_TX_Window_Size” is less than 2048, i.e. half the amount of different numbers that can be represented by a 12-bit SN, any PDU that has not yet been acknowledged (for example, PDUs 400 , 401 , 402 , 403 and 404 in FIG. 5 ) can be selected as the suitable PDU and scheduled for retransmission in order to carry the poll. ‘Transmission window size’ relates to parameters for the maximum number of PDUs, (in effect, a window size), that the transmitting station can transmit (and that the receiving station can receive) without receiving some form of status message from the receiving station. Again, the upper layers configure this parameter.
[0049] Unfortunately, there are situations allowable in the prior art whereby ‘deadlock’ may arise. Please consider the following example, which assumes the same initial conditions as the example shown by FIG. 5 above, i.e. that a transmitter is configured by upper layers to enable the following five poll triggers:
[0050] (1) “Last PDU in buffer (for first time transmission)”;
[0051] (2) “Last PDU in Retransmission buffer”;
[0052] (3) “Poll timer” (with Timer_Poll=200 ms);
[0053] (4) “Every Poll_PDU PDU” (with Poll_PDU=4); and
[0054] (5) “Every Poll_SDU SDU” (with Poll_SDU=4).
[0055] Again, as for the example shown by FIG. 5 above, assume also that the ‘Window based’ trigger and ‘Timer based’ trigger are disabled, that the poll prohibit function is configured with Timer_Poll_Prohibit=250 ms, that one SDU is requested for transmission by an upper layer and an RLC transmission confirmation is requested by the upper layer when transmission of the SDU is positively acknowledged, and that the SDU is segmented into six PDUs.
[0056] Please refer to FIG. 6 , which illustrates the present example. The transactions between the transmitting station 41 and the receiving station 42 are identical to the example shown by FIG. 5 regarding the initial transmission of PDUs 400 ˜ 405 , except that in this example the status report 406 positively acknowledges PDUs 400 ˜ 403 (SNs 0˜3) and the transmitting station 41 receives the status report successfully. According to the prior art, this has the affect of cancelling the Timer_Poll function 45 at a time 47 , and although a “Last PDU in buffer” poll trigger delayed until a time 44 , no PDU will be scheduled for transmission/re-transmission. This is because, in this case, there are no more SDUs (and hence, no more PDUs) to be transmitted, no negatively acknowledged PDUs to be re-transmitted, and a PDU with SN=VT(S)−1 may only be scheduled when a poll delayed by Timer_Poll_Prohibit is initiated by ‘poll timer’ or ‘timer based’ functions according to Steps 1006 and 1007 in FIG. 4 . As the Timer_Poll function 45 is cancelled and no timer based function is configured, these conditions can not be met, and hence according to the prior art set forth by 3GPP TS 25.322 or by FIG. 4 above, the transmitting station 41 will remain idle following receipt of the abovementioned status report 406 , without scheduling any PDUs for transmission or retransmission, i.e. there is no further traffic with which to transmit a poll. Without a status report acknowledging the successful receipt of the fifth and sixth PDUs, RLC transmission confirmation cannot be sent to the upper layers, consequently RLC layers at both the transmitter and the receiver stations cannot proceed to any further operations, i.e. the RLC layers are deadlocked.
[0057] There is a need then for a method which, when implemented in a 3GPP radio communications system, will circumvent the abovementioned RLC layer deadlock situation.
SUMMARY OF THE INVENTION
[0058] A method of polling in a wireless communications system includes prohibiting polling within a predetermined period and triggering a poll function while polling is prohibited, wherein the poll function is triggered by a “window-based” trigger that triggers the poll function when a predetermined percentage of a transmission window is reached. After the predetermined period has expired the method determines that there are no protocol data units (PDUs) scheduled for transmission or re-transmission, and selects a PDU to schedule for re-transmission to fulfill the triggered poll function.
[0059] These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0060] FIG. 1 is a block diagram of the three layers typical of a communications system according to the 3 rd Generation Partnership Project (3GPP™) communications protocol.
[0061] FIG. 2 is a block diagram showing an example of an acknowledged mode data protocol data unit (AMD PDU) according to the prior art.
[0062] FIG. 3 is a message sequence chart representing AMD PDU transfer between a transmitting station and a receiving station according to the prior art.
[0063] FIG. 4 is a flow diagram of the polling process according to the prior art.
[0064] FIG. 5 is a message sequence chart representing AMD PDU transfer between a transmitting station and a receiving station according to the prior art.
[0065] FIG. 6 is a message sequence chart representing an example of deadlock in a wireless communications system according to the prior art.
[0066] FIG. 7 is a message sequence chart representing a preferred embodiment method of AMD PDU transfer according to the present invention.
[0067] FIG. 8 is a flow diagram of a preferred embodiment of the present invention method.
DETAILED DESCRIPTION
[0068] In order to overcome the prior art problems described above, a preferred embodiment method of the present invention is described by example below.
[0069] Assuming the transmitter is configured by upper layers to enable the following four poll triggers:
[0070] (1) “Last PDU in buffer (for first time transmission)”,
[0071] (2) “Last PDU in Retransmission buffer”,
[0072] (3) “Poll timer” (with Timer_Poll=200 ms),
[0073] (4) “window based” (triggering a poll when 50 percent of a transmission window is reached).
[0074] And also assuming that: other poll triggers are disabled, the poll prohibit function is configured with Timer_Poll_Prohibit=250 ms, the transmission window size is 8 for simplicity, one SDU is requested for transmission by an upper layer and an RLC transmission confirmation is requested by the upper layer when transmission of the SDU is positively acknowledged, and that the SDU is again segmented into eight PDUs (having sequential SNs: 0, 1, 2, 3, 4, 5, 6 and 7).
[0075] In the example illustrated by FIG. 7 , the receiving station 72 successfully receives all four PDUs 700 ˜ 703 (SN=0˜3) wherein the fourth PDU 703 (SN=3) is received with a poll, and sends a status PDU 710 positively acknowledging the PDUs having SNs=0˜3. The transmitting station 71 receives this status report 710 successfully at a time 77 before the current instance of the Timer_Poll function 75 expires, thereby canceling the Timer_Poll function 75 , thus no poll is issued at the time 76 when the Timer_Poll function 75 countdown was due to expire. When the transmitting station 71 transmits the PDUs 704 ˜ 706 having SN=5˜6 respectively, polls are triggered by the “window based” trigger since the transmission window is over 50%, but these polls are delayed because poll is prohibited when these PDUs 704 ˜ 706 are sent out. In addition, when the transmitting station 71 transmits the PDU 707 having SN=7, a poll is triggered by the “Last PDU in buffer (for first time transmission)” trigger, but this poll is also delayed because poll is prohibited when this PDU 707 is sent out. When the Timer_Poll_Prohibit function 73 expires, the transmitting station 71 finds that these delayed polls 78 and 79 ˜ 81 (having been triggered by the “Last PDU in buffer (for first time transmission)” and the “window based” triggers respectively) are awaiting transmission. There are no more PDUs scheduled for transmission or re-transmission, and under the prior art scheme, no PDU can be scheduled because none of the relevant polls was triggered by a “Poll Timer” or “Timer based” function (Step 1007 in FIG. 4 ). Note also that, because the existing Timer_Poll function 75 is canceled by the status report 710 , there is no likelihood of a suitable poll trigger occurring due to the “Poll timer” function. Hence, in the method of the present invention, upon expiration of the Timer_Poll_Prohibit function 73 , the type of the relevant polls are checked, i.e. whether any of the relevant poll is triggered by the “window based” trigger. In this example, the test will be positive and, according to the present invention method, the transmitting station 71 will re-transmit a suitable PDU 707 a , which can be the last PDU 707 (SN=7), this being the current SN=VT(S)−1 PDU with poll bit set. When the receiving station 72 receives the re-transmission of the PDU 707 (SN=7), i.e., the PDU 707 a , this time including a poll, the receiving station 72 will send a status report 712 to positively acknowledge the successful receipt of all PDUs up to and including SN=7. Upon receiving the status report 712 , the transmitting station 71 can send confirmation of SDU receipt to the upper layer (not shown in FIG. 7 ) so that the upper layer can proceed to subsequent processes, thus avoiding the deadlock situation inevitable under the prior art scheme. Thus, employing the method of the current invention can circumvent the deadlock shown to occur when the prior art method is applied to such a scenario.
[0076] The present invention method can be implemented as software or firmware in a wireless communications system, incorporated in the architecture of, for example, a monolithic communications microchip for use in the same, or realized in the structure of supporting discrete or programmable logic device(s). The present invention method can be summarized in the following process ( FIG. 8 refers):
[0077] In FIG. 8 , Step 1007 is FIG. 4 is replaced by 1007 a . In other words, if the polling function checked at Step 1003 is triggered by the “window based” trigger, the system retransmits a suitable PDU to carry the poll bit. Only Step 1007 a is described below since all the other steps are exactly the same as those in FIG. 4 .
[0078] Step 1007 a : The system checks if the polling function was triggered by a “window based” trigger. If the checking result is yes, the process proceeds to Step 1008 . Otherwise, the process terminates via Step 1017 .
[0079] Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.
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A method of polling in a wireless communications system includes prohibiting polling within a predetermined period and triggering a poll function while polling is prohibited. After the predetermined period has expired the method determines that there are no protocol data units (PDUs) scheduled for transmission or re-transmission and that the poll function was triggered by a “window-based” trigger, and selects a PDU to schedule for re-transmission to fulfill the poll function.
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RELATED APPLICATIONS
This application is a divisional of application Ser. No. 09/364,468, filed Jul. 30, 1999, now U.S. Pat. No. 6,301,646 the entire teachings of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
In recent years, the number of users on the Internet has increased exponentially. With this increase in popularity, there has also come an increased demand for languages that enhance the “on-line” experience. To this end, new object-oriented computer-programming languages such as Curl™ and JAVA™ have been developed, which ostensibly provide not only platform independence, but also increased functionality.
A common problem for these languages is the utilization of memory. These languages allocate memory from free storage and reclaim (“garbage collect”) the allocated memory once it is no longer in use. An important aspect of garbage collection is the mapping of object pointers to information about those pointers. Thus, a set of auxiliary data structures are used for things like marking the object “alive” and figuring out which other objects this one points to. The problem of finding this data is compounded in conservative garbage collectors where pointers to objects are followed and the memory utilized by those objects is reclaimed only under a conservative standard.
In such systems, a value that looks like a pointer may in fact be junk with no associated information. Therefore, a system for efficient determination of the validity of a pointer is needed.
SUMMARY OF THE INVENTION
This invention executed on a computer, provides an efficient and compact way to map pointers to auxiliary data by which the validity of pointers can be determined. The invention relies on a data structure which can be efficiently updated as a memory is allocated to memory blocks and as those memory blocks are deallocated. The data structure allows for efficiently determining whether a particular pointer or set of pointers points to a valid portion of allocated memory.
In accordance with one aspect of the invention, a table of the memory pages may be indexed by each pointer during memory allocation, deallocation, and status checking. An index entry in the table points to a memory block which contains at least a portion of the indexed page. Memory blocks, including memory blocks of multiple pages, into which the memory pointers point, indicate whether the pointer is valid. For example, each memory block may include an array of bits, each associated with a word in the memory block to indicate whether the pointer to that word is valid. A memory block which covers multiple pages will have a table entry for each page, each entry pointing to the same memory block which provides the information required to determine whether the pointer is valid.
Where more than one memory block overlaps an indexed page, it is preferred that the table entry point to only one of the overlapping memory blocks and that the memory block, to which the indexed table entry points, itself points to any other memory block overlapping the indexed page. Preferably, each memory block in the system is at least the size of one page so that the information is found in either the memory block to which the table entry points or a single memory block to which that memory block points.
In accordance with the preferred embodiment, each memory block allocated from a pool of free memory has a size that is at least as large as a predefined page size and further includes slots for storing representations (such as an address or index) of a starting address, an ending address, a next memory block address, and data. The slot for the representation of a starting address is initialized with a representation of the starting address of the data; the slot for the representation of an ending address is initialized with a representation of the ending address of the data; and if a previously created memory block that starts on the last page of this memory block exists, a representation of the address of this newly created memory block is entered in the next memory block address slot of the previously allocated memory block.
Each of the pages in the memory block is indexed into a set of tables. In a system with two page tables, the first page table is checked for an entry found by indexing into the first page table with a first portion of the address to the first page of the memory block. If the entry is null, then a second page table is created, this page table having a set of entries for storing representations of addresses to memory blocks. An entry is created in the first page table entry selected by the first portion of the address of the memory block to store a representation of the address of the second page table. In addition, in the second page table, at the entry selected by a second portion of the address of the memory block, an entry is created for a representation of the address to the memory block.
If the entry in the first page table is not null, then the second page table is selected by using the representation of the address to the second page table found in the first page table. A second page table entry is found by indexing into the second page table with the second portion of the address of the page of the memory block, and if this entry is null, entering the representation of the memory block address.
If this page entry is not null, then a previously indexed memory block is present. If this is the first page of the memory block in question, then the previously indexed memory block starts on this page. A representation of the address of this newly created memory block is then entered in the next memory block address slot of the previously allocated memory block. If this is not the first page of the memory block in question, then the previously indexed memory block ends on this page. A representation of the address of this newly created memory block is then entered into to the second page table entry and the former contents of this entry are placed in the next memory block address slot of the newly allocated memory block. This also represents the ending page of the newly allocated memory block and thus the method is complete.
The invention further includes a system and method for determining the validity of a pointer in a system having a first page table, a set of zero or more second page tables, and a set of zero or more memory blocks. The first page table has a sequence of entries for storing representations of addresses for a second page table; the second page table has a sequence of entries for storing representations of addresses for a memory block; and the memory blocks have slots to store representations of a starting address, an ending address, a next memory block address, and data.
The system and method utilize the steps of checking for an entry in the first page table found by indexing into the first page table with a first portion of the address of the pointer. If the entry thus found is null, then the pointer is invalid. If the entry is not null, then a second page table is selected using the representation of the address to the second page table found in the entry from the first page table. The second page table is checked by indexing into the table with the second portion of the pointer. If the entry thus found is null, the pointer is invalid. If the entry is not null, then a memory block is selected from the set of one or more memory blocks using the entry in the second page table. The pointer is then checked for validity in the selected memory block or in a separate memory block pointed to by the selected memory block.
Thus, the system and method can efficiently allocate memory blocks. In addition, the system and method can determine the validity of a pointer via a series of table lookups.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention.
FIG. 1 is a diagram illustrating a computer system for implementing garbage collection utilizing the invention;
FIG. 2 is a block diagram illustrating the components in a computer system for implementing garbage collection utilizing the invention;
FIG. 3 is a block diagram illustrating the data structures for translating a pointer according the invention;
FIG. 4 is a block diagram illustrating the organization of MemoryBlocks in a system according to the invention;
FIG. 5 is a flowchart illustrating the method of initializing the tables utilized in the invention;
FIG. 6 is a flowchart illustrating the method of allocating a MemoryBlock according to the invention;
FIG. 7 is a flowchart illustrating the method of checking a pointer according to the invention; and
FIG. 8 is a flowchart illustrating the method of de-allocating a MemoryBlock according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows an example of a personal computer (PC) on which the present invention may be implemented. As shown, PC 1 includes a variety of peripherals, among them being: i) network connection 2 for interfacing to a network or internet, ii) a fax/modem 4 for interfacing with telecommunication devices (not shown), iii) a display screen 5 for displaying images/video or other information to a user, iv) a keyboard 6 for inputting text and user commands and a mouse 7 for positioning a cursor on display screen 5 and for inputting user commands, and v) a set of disk drives 9 for reading from and writing to a floppy disk, a CDROM and/or a DVD. PC 1 may also have one or ore local peripheral devices connected thereto, such as printer 11 .
FIG. 2 shows the internal structure of PC 1 . As illustrated, PC 1 includes mass storage 12 , which comprises a computer-readable medium such as a computer hard disk and/or RAID (“redundant array of inexpensive disks”). Mass storage 12 is adapted to store applications 14 , databases 15 , and operating systems 16 . In preferred embodiments of the invention, the operating system 16 is a windowing operating system, such as RedHat® Linux or Microsoft® Windows98, although the invention may be used with other operating systems as well. Among the applications stored in memory 12 is a programming environment 17 and source files. Programming environment 17 compiles the source files written in a language that creates the output generated by the present invention. In the preferred embodiment of the invention, this language is Curl™, developed by Curl™ Corporation of Cambridge, Mass.
PC 1 also includes display interface 20 , keyboard interface 21 , mouse interface 22 , disk drive interface 24 , CDROM/DVD drive interface 25 , computer bus 26 , RAM 27 , processor 29 , and printer interface 30 . Processor 29 preferably comprises a Pentium II® (Intel Corporation, Santa Clara, Calif.) microprocessor or the like for executing applications, such those noted above, out of RAM 27 . Such applications, including the programming environment and/or the present invention 17 , may be stored in memory 12 (as above) or, alternatively, on a floppy disk in disk drive 9 . Processor 29 accesses applications (or other data) stored on a floppy disk via disk drive interface 24 and accesses applications (or other data) stored on a CDROM/DVD via CDROM/DVD drive interface 25 .
Application execution and other tasks of PC 1 may be initiated using keyboard 6 or mouse 7 , commands from which are transmitted to processor 29 via keyboard interface 21 and mouse interface 22 , respectively. Output results from applications running on PC 1 may be processed by display interface 20 and then displayed to a user on display 5 or, alternatively, output to a network via network connection 2 . To this end, display interface 20 preferably comprises a display processor for forming images based on image data provided by processor 29 over computer bus 26 , and for outputting those images to display 5 .
During normal operation, the system allocates objects within defined memory blocks of varying size to individual applications. When an application no longer requires a memory object, the words which make up that object can be indicated as invalid until required again by the application. When a memory block is no longer required, and all words within it are invalid, the memory block is deallocated and is thus available to be allocated to another application. To keep track of any valid pointers which point to locations within allocated memory, the present invention relies on a novel data structure comprising a sparse two-level page table. For any pointer which is valid, there is an entry in the page table which points to a descriptor of the memory block, preferably in a header to the memory block. The descriptor may, for example, be an array of bits which indicate whether individual words within the memory block are valid.
In one embodiment of the invention, a set of tables is created to facilitate the translation of pointers during garbage collection (See, Garbage Collection , Jones, Richard and Lins, Rafael, John Wiley & Sons, 1996, whose teachings are incorporated herein by reference.) The tables are indexed by subdividing the pointer into portions and utilizing the portions to index into the set of tables.
FIG. 3 illustrates one embodiment of the invention for a computer system utilizing 32 bit pointers which are used to directly access memory locations. In this embodiment, for purposes of indexing the translation tables, the pointer 50 is partitioned into three portions 51 , 52 and 53 . The high 10 bits of the pointer 50 serve as an index 51 into the first-level table 54 pointing to an entry 55 . Each entry of the first-level table is either null, meaning the pointer being looked up (call it p) is invalid and the search can stop, or a pointer to a second-level table 56 .
The second-level table 56 is indexed using the next highest 10 bits 52 of the pointer 50 to select an entry 59 . Each element of this table is either null, meaning that p is invalid and the search can stop, or a pointer to a MemoryBlock data structure 60 , 61 or 62 that can be used to find information about p, specifically whether p is within that or an adjacent MemoryBlock.
Because 20 bits of the address have been consumed by the table lookups en route to finding the MemoryBlock, only the low 12 bits 53 have been ignored. Therefore any pointer in the same aligned 4 Kbyte block of memory will map to the same page. Of course, the size of the tables used to reach the MemoryBlock can easily be changed, for example using 9 bits of p to index the first-level table and the next 11 bits to index the second-level table. One could use a page table with more than two levels if desired. Whatever the configuration, call the size of the memory specified by the ignored bits the “page size” (4 Kbytes in the example given above).
The pointer 50 is used to address memory locations within a MemoryBlock, which need not be aligned with pages. As illustrated in FIG. 3, each MemoryBlock 60 defines a starting address, an ending address, and a page table next pointer. The page table next pointers are set up in such a way that either the MemoryBlock found in the second-level table contains the location to which p points, or the MemoryBlock pointed to by its page table next pointer contains the location to which p points; otherwise p is invalid.
This invariant is maintained by making the following assumption as shown in FIG. 4 . First, every MemoryBlock 101 , 102 , 103 , and 104 is at least as big as a page, in this case 4 Kbyte in size 100 . This implies three things:
i) at most one MemoryBlock can start on a page,
ii) at most one MemoryBlock can end on a page, and
iii) at most two MemoryBlocks can intersect a given page.
Therefore, only the two MemoryBlocks identified can contain the data pointed to by the pointer.
The entry in the second-level table for a given page is a sorted linked list of MemoryBlocks, linked by the page table next pointers, such that only the first two MemoryBlocks in the list may possibly intersect that page. There are three cases:
1) If no MemoryBlock intersects this page, the list will be empty (null). This means the pointer being looked up is invalid.
2) Else, if a MemoryBlock intersects this page, but no MemoryBlock starts on this page, that block will be the entry in the second-level table (the first entry in the list.)
3) Else some MemoryBlock starts on this page. It will be the entry in the second-level table (listed first.) If any other MemoryBlock intersects this page, it will be in the page table next field of the MemoryBlock indicated in the entry of the second-level table (and thus will be listed second.)
A consequence of these invariants is that MemoryBlock lists are always sorted by address, with higher addresses first. This data structure could be implemented with a single linked list of MemoryBlocks sorted by address, with the second-level tables pointing into this list.
Because finding the MemoryBlock list for a page takes O( 1 ) time, and only the first two entries in the list need ever be examined, this invention allows pointers to be both validated and mapped to their containing MemoryBlock in O( 1 ) time.
FIG. 5 illustrates the steps of initializing the first page table. This table can be implemented as an array of a fixed size that is simply allocated at step 111 and initialized to contain all nulls in step 112 .
The system creates the remaining structure as it allocates MemoryBlocks. FIG. 6 illustrates the steps in allocating a MemoryBlock. Initially, the system needs to allocate another MemoryBlock 120 . A block of memory from the free memory pool is allocated 121 , the block being at least as big as the page size and possibly larger depending upon the request. The slots in the MemoryBlock are filled in including the starting address for the data area, the ending address for the data area, the page table next pointer (initially null) and the data 122 . The MemoryBlock may be composed of a number of pages, thus the following steps are performed for each page. Initially, the initial page of the MemoryBlock is determined 123 .
The first page table is indexed with the first portion of the address for the current page of the MemoryBlock 124 . The entry located at this position in the first page table is checked. If it is null 125 (thus indicating that no second page table has been created for this address range), then a sequence of steps will create the necessary information to initialize the entry.
At step 135 , the second page table is created and initialized. Next, the pointer to the new second page table is entered into the first page table 136 . Finally, an entry is created in this page table for the page of the MemoryBlock in question utilizing the second portion of the address for the page 137 .
If, at step 125 , there is an entry in the first page table, then the entry is used to find the second page table 126 , and the second portion of the page address is used to index into this table 127 . If the entry in this table is null 128 , then the pointer to the MemoryBlock is entered into this position 137 .
If, at step 128 , the second page table entry is not null, then there must have been a prior MemoryBlock that was allocated that either started or ended on this page. If this is the first page of the MemoryBlock to be indexed 129 , then the prior entry must be for a MemoryBlock that ended on this page. In this case, the page table next pointer in the MemoryBlock is initialized with the entry found in the second page table 132 . Then, the entry in the second page table is filled with current MemoryBlock 133 . Thus, the entry in the second page table is replaced to point to the current MemoryBlock because it is the MemoryBlock that starts on this page while the former entry in the second page table is stored in the page table next entry of the current MemoryBlock.
If, at 129 , the page in question is not the first page for the MemoryBlock, and there is an existing entry in the second page table for this MemoryBlock, then this must be the last page of the MemoryBlock (as only two pages can ever index onto one page, thus one must be the ending page of a MemoryBlock and the other must be a starting page of a MemoryBlock.) In this case, the page table next entry of the MemoryBlock pointed to by the second page table is initialized with the current MemoryBlock 130 . Since this is the last page, the process exits 131 .
Thus, after either step 137 or step 133 , the next step is to get the next page in the MemoryBlock to be indexed 134 . The process is then repeated for this page of the MemoryBlock by going back to step 124 .
A pointer is checked by utilizing the structures thus created. FIG. 7 illustrates the steps in checking a pointer for validity. Initially, the first portion of the pointer ( 51 of FIG. 3) is obtained 141 used to index into the first page table 142 . The entry in the first page table is checked, and if it is null the pointer is invalid and the operation exits. If the entry is not null, then it is used to find the second page table 145 . Now the second portion of the pointer ( 52 of FIG. 3) is used to index into this second page table 146 .
The entry in the second page table is checked to determine if it is null 147 . If it is, the pointer is invalid and the operations exits 148 . If the pointer is not null, then the MemoryBlock pointed to by this entry is examined 149 to determine if the pointer is within that MemoryBlock and is thus valid 150 . If the pointer is valid, then the operation so signals and then exits 153 .
If the pointer is not in the MemoryBlock, it still may be in the MemoryBlock referenced to by the page table next entry 154 . If the pointer is in this MemoryBlock, the pointer is valid; the operation so signals and exits 156 . Otherwise, the pointer is invalid and the operation so signals and exits. Once all the pointers have been checked, the unused memory can be freed for reallocation.
During normal operation of the system, memory blocks are allocate and reclaim as they are used. As one step in the reclamation of the storage allocated memory block, the entries in the page tables must be updated to remove reference to the actual memory block. FIG. 8 illustrates the step necessary in deleting references to a memory block.
Initially, the process 180 starts by deriving the first page to the memory block, 181 . The first page table is indexed with the first portion of the address for the current page and the entry is retrieved 182 . The entry is used to select the second page table 183 . The second page table is then indexed utilizing the second portion of the address to the current page and the entry is retrieved.
The current page is tested to see if it is the last page for the memory block (or the only page) 185 . If so, the entry from the second page table is checked to see if it points to the memory block we are deleting 186 . If so, we set the second page table entry to null 187 and end the process 189 . If the entry in the second page table points to a different memory block from the one we are deleting 186 , then this different memory block must have its page table next pointer pointing to the memory block being deleted. This page table next entry is thus set to null 188 and the process is complete 189 .
If it is determined that this page is not the last page in the memory block 185 , then we check to see if this is the first page in the memory block 190 . If it is not, we set the entry in the second page table to null 191 . If it is the first entry 190 , then we need to update the entry in the second page table to contain the value in the page table next slot of the memory block being deleted 194 . In either case, once the entry in the second page table is updated the next page in the memory block is determined 195 and the process repeats through the remaining pages.
As a final process in reclaiming allocated storage, second page tables may also be deleted once all the entries in a particular second page table become null (signifying that all the memory blocks indexed via that table have been reclaimed). This can be achieved by walking through the first and second page table structures.
In addition, though the present invention has been described with respect to the Curl™ language, it is not limited to this context, and may be used in connection with any programming language. Finally it is noted that the process steps shown in FIGS. 5-8 need not necessarily be executed in the exact order shown, and that the order shown is merely one way for the invention to operate. Thus, other orders of execution are permissible, so long as the functionality of the invention is substantially maintained.
The present invention has been described with respect to a particular illustrative embodiment. It is to be understood that the invention is not limited to the above-described embodiment and modifications thereto, and that various changes and modifications may be made by those of ordinary skill in the art without departing from the spirit and scope of the appended claims.
While this invention has been particularly shown and described with references to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.
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A system and method for allocating memory blocks and indexing the pointer to the memory blocks in a set of tables. The tables translate the pointers to the memory blocks enabling the efficient lookup of pointers during translation and garbage collection. The memory blocks further include structures for facilitating the indexing into tables and referencing pointers into allocated memory.
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BACKGROUND OF THE INVENTION
[0001] This invention relates to methods of efficiently applying low temperature heat to absorption refrigeration cycles and absorption power cycles. In conventional absorption cycles, high temperature heat is applied to a high-pressure desorber or generator, where high-pressure vapor is desorbed from the absorbent solution. When the resulting vapor is pure refrigerant, as with LiBr-H 2 O absorption cycles, no further treatment is necessary. When the resulting vapor has appreciable absorbent content, as with NH 3 -H 2 O absorption cycles, it is necessary to distill, analyze, or rectify the vapor to higher refrigerant purity by contacting it with lower temperature absorbent. That distillation may be done either adiabatically or diabatically. The external heat addition portion of the desorber is customarily termed the generator, and the distillation portion may have internal heat addition.
[0002] When the external heat source is at relatively low temperature, for example only modestly above the generator temperature, and when it has a temperature glide, then very little of the heat content of the source can be effectively transferred to the generator using conventional techniques. Consider for example a combustion exhaust stream at 270° C., and an absorption cycle generator at 170° C. Given a 30° C. minimum temperature difference for heat transfer, it is only possible to cool the heat source from 270° C. to 200° C. by transferring heat to the generator. This is only on the order of 30% of the available heat content of that source.
[0003] Two other possible problems arise when supplying low temperature waste heat such as combustion exhaust gas to an absorption cycle. With one approach, the combustion exhaust directly contacts the heat transfer surface of the generator. However, there are usually stringent limitations on the allowable pressure drop of the exhaust gas. For example, the backpressure for a combustion turbine is typically specified at no more than six to ten inches water column. The generator which satisfies both this criterion and also the specialized mass transfer criteria of the absorbent solution will be very large and costly. That is, the transfer geometry necessary for effective desorption is very different from that necessary for low Δp extraction of heat from combustion gas. Alternatively a closed cycle heat transfer fluid can be circulated between the heat source and the generator, such that the geometry of each heat exchanger is free to be optimized for the respective requirements. This has the disadvantage that two separate heat exchanger temperature differentials are interposed between the waste heat and the absorbent solution in the generator. For example, the heat transfer fluid must be heated to well above the generator peak temperature. If water is the heat transfer fluid, it will have to be at a much higher pressure than the generator.
[0004] There are a variety of hydrocarbon-fueled prime movers which exhaust a combustion gas, including gas turbines, microturbines, reciprocating engines, and fuel cells. Depending upon the prime mover, the exhaust temperature varies from 200° C. to 550° C. There is increasing need and desire to convert that exhaust heat to useful purpose, such as cooling, refrigeration, shaft power, or electricity. It is one objective of the present invention to convert greater fractions of waste heat to useful purpose than has heretofore been possible. It is another objective to avoid the prior art disadvantages of applying waste heat to absorption cycles, i.e., the high backpressure associated with direct contact heat transfer, and the high temperature differentials associated with pump-around loops. That is, there is a need for a method of transferring heat from a low temperature sensible heat source to an absorption cycle which avoids the Δp and ΔT and high pressure penalties associated with traditional methods, while achieving greater utilization of the heat source, i.e., more useful result.
BRIEF SUMMARY OF THE INVENTION
[0005] The above and other useful objects are achieved by apparatus wherein thermal energy is converted into at least one of refrigeration, cooling, and shaft power comprising:
[0006] a) an absorbent solution comprised of sorbate plus absorbent;
[0007] b) a desorber comprised of:
[0008] i) an entry port for sorbate-rich liquid absorbent;
[0009] ii) a means for separating said sorbate-rich absorbent into sorbate vapor and sorbate-lean absorbent;
[0010] iii) an exit port for said sorbate vapor; and
[0011] iv) an internal heat exchanger which has an entry port in communication with said sorbate-lean absorbent;
[0012] c) an external heat exchanger which is in thermal contact with said thermal energy;
[0013] d) a first flowpath from an exit port of said internal heat exchanger to said external heat exchanger; and
[0014] e) a second flowpath from said external heat exchanger to said desorber;
[0015] and also by process comprising:
[0016] a) circulating an absorbent solution successively through absorbing and desorbing steps;
[0017] b) desorbing the absorbent solution into high-pressure sorbate vapor and heated strong absorbent by heating it;
[0018] c) using the heated strong absorbent as the heating agent in step b);
[0019] d) reheating said heating agent by thermally contacting it with said thermal energy; and
[0020] e) combining said reheated heating agent with said heated strong absorbent.
[0021] The greater utilization of the thermal energy in the waste heat or other low temperature heat source is accomplished by applying it to a heat transfer agent, and then applying the heat transfer agent heat to at least part of a distillation step,( when present) which is at lower temperature, and/or by applying it to an intermediate-pressure desorber which is at lower temperature. Either or both of these steps further reduce the heat transfer agent temperature to below the high-pressure generator temperature, and in turn make it possible to reclaim lower temperature heat from the heat source. With this technique, the heat transfer agent can be routinely cooled to approximately 80° C. or lower, which means the combustion gas can be cooled to approximately 100° C. or lower.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0022] [0022]FIG. 1 depicts one embodiment of the integrated heating system constituent parts and their arrangement.
[0023] [0023]FIG. 2 depicts a two-pressure single-effect absorption cycle with co-current mass exchangers which produces cooling from low temperature waste heat using the integrated heating system.
[0024] [0024]FIG. 3 depicts a three-pressure absorption cycle for a volatile absorbent such as NH 3 -H 2 O which is adapted to produce shaft power from waste heat using an integrated heating system.
[0025] [0025]FIG. 4 depicts a two-pressure absorption cycle adapted to produce both power and cooling from combustion turbine exhaust via an integrated heating system.
[0026] [0026]FIG. 5 depicts a three-pressure absorption refrigeration cycle powered by low temperature heat via an integrated heating system.
DETAILED DESCRIPTION OF THE INVENTION
[0027] Referring to FIG. 1, a low temperature sensible heat stream such as combustion exhaust gas is supplied to heat reclaimer 1 through inlet 2 , where it contacts the external heat exchanger 3 . Pump 4 circulates a heat transfer fluid through heat exchanger 3 , in direction overall counter-current to the flow direction of the exhaust gas. By having the heat reclaimer 1 vertically oriented as shown, any condensate formed on the cooler bottom coils drains away, and also the coils can be adapted to be self-draining should pump 4 fail, thus preventing over-pressurization. The heated heat transfer fluid exits reclaimer 1 preferably as a two-phase mixture and is routed to desorber 5 , where phase separation occurs. The resulting liquid phase comprised of both liquid from the reclaimer and also sorbate-lean absorbent solution (i.e. “weak” absorbent) from the remainder of the desorber, is routed through pipe 6 into internal heat exchanger 7 which supplies heat to colder portions of the desorber, for example, by means of a succession of vertically stacked diabatic trays 49 . The hot vapor also traverses up through the desorber, on the other side of internal heat exchanger 7 . The purified vapor exits the generator through pipe 8 and is routed to the remainder portion of the absorption cycle 9 . The heat transfer fluid exits the internal heat exchanger 7 and desorber 5 through pipe 10 , and is split at splitter 12 , with part going via pressure letdown valve 13 to the absorption step in portion 9 , and the remainder to pump 4 for recycle to reclaimer 1 . The high-pressure vapor from pipe 8 is converted in portion 9 to a low-pressure vapor, via a condenser and evaporator so as to produce cooling, and/or via a work expander to produce shaft power. The resulting low-pressure vapor and absorbent from pipe 10 are subsequently recombined in portion 9 and pumped back to the entry port for sorbate-rich absorbent of desorber 5 via pipe 11 . The heat exchanger in reclaimer 1 can be comprised of concentric tube coils, pancake tube coils, or any other known geometry, e.g., fin tubes, folded plates, or others such as those used for steam cycle economizers. Particularly pertinent are the steaming type of economizers which ordinarily produce a two-phase mixture. With ammonia-water cycles, the heat transfer fluid will usually be nearly pure water, and the pressure will be essentially the generator pressure, since the two fluids combine at the generator. With LiBr-H 2 O absorption cycles, the circulating heat transfer fluid will be concentrated LiBr solution.
[0028] By integrating the heat transfer fluid directly into the absorption cycle, the advantage is retained that the reclaimer can be optimized for the necessary low pressure drop, and yet there is no additional temperature differential penalty because the heating fluid temperature never increases to appreciably above the hottest generator temperature. Since most of the heating duty in the heat reclaimer is sensible heating of the heating agent, the temperature difference between the heating agent and the combustion exhaust can be relatively constant, resulting in highly efficient heat exchange, i.e., avoiding the pinch temperature associated with constant temperature boilers.
[0029] In FIG. 2 and succeeding figures, objects with similar descriptions are afforded the same number in each sequence, e.g., object 201 of FIG. 2 is described similarly as object 101 of FIG. 1.
[0030] Referring to FIG. 2, low temperature sensible heat is supplied to heat reclaimer 201 via entry port 202 . Pump 204 circulates heat transfer agent through reclaimer 201 counter-currently to the exhaust flow direction. Two-phase heat transfer agent is then routed to the hot end of generator 205 (also called a desorber). Vapor is withdrawn via pipe 208 , and hot liquid is supplied to an internal heat exchanger in generator 205 via pipe 206 . That liquid exits at pipe 210 , is split at splitter 212 , with part being recycled via pump 204 , and the remainder supplied to low-pressure absorber 217 via pressure letdown valve 213 . High-pressure vapor in pipe 208 is condensed in condenser 214 , subcooled in subcooler 215 , reduced in pressure in pressure letdown 219 , and evaporated in evaporator 216 . The resulting low-pressure vapor is absorber into sorbate-lean (“strong”) absorbent 217 , which is cooled by coolant 220 , and the resulting sorbate-rich (“weak”) absorbent is pumped by pump 218 back to desorber 205 . The various exchanges may be shell and tube, coil in shell, or other known types.
[0031] Referring to FIG. 3, waste heat enters reclaimer 301 through entry port 302 . Heat transfer fluid is counter-currently circulated through steaming economizer 303 via pump 304 , and thence to the bottom of desorber column 305 , where phase separation occurs. The liquid phase enters internal heating coils 307 via inlet pipe 306 . Part of the llliquid phase is split off at splitter 312 and routed to pressure letdown 313 via solution heat exchanger 326 . The remainder heats the colder top end of column 305 , then supplies lower temperature heat to intermediate pressure desorber 323 , and then is recycled by pump 304 . Desorber vapor in pipe 308 is superheated in superheater 321 by counter-current heat exchange with the source heat, in parallel with exchanger 303 . Then the superheated vapor is work-expanded in expander 322 . The resulting low-pressure vapor is absorbed in low-pressure absorber 317 into the strong absorbent from letdown 313 , while absorption heat is removed
[0032] By integrating the heat transfer fluid directly into the absorption cycle, the advantage is retained that the reclaimer can be optimized for the necessary low pressure drop, and yet there is no additional temperature differential penalty because the heating fluid temperature never increases to appreciably above the hottest generator temperature. Since most of the heating duty in the heat reclaimer is sensible heating of the heating agent, the temperature difference between the heating agent and the combustion exhaust can be relatively constant, resulting in highly efficient heat exchange, i.e., avoiding the pinch temperature associated with constant temperature boilers.
[0033] In FIG. 2 and succeeding figures, objects with similar descriptions are afforded the same number in each sequence, e.g., object 201 of FIG. 2 is described similarly as object 101 of FIG. 1.
[0034] Referring to FIG. 2, low temperature sensible heat is supplied to heat reclaimer 201 via entry port 202 . Pump 204 circulates heat transfer agent through reclaimer 201 counter-currently to the exhaust flow direction. Two-phase heat transfer agent is then routed to the hot end of generator 205 (also called a desorber). Vapor is withdrawn via pipe 208 , and hot liquid is supplied to an internal heat exchanger in generator 205 via pipe 206 . That liquid exits at pipe 210 , is split at splitter 212 , with part being recycled via pump 204 , and the remainder supplied to low-pressure absorber 217 via pressure letdown valve 213 . High-pressure vapor in pipe 208 is condensed in condenser 214 , subcooled in subcooler 215 , reduced in pressure in pressure letdown 219 , and evaporated in evaporator 216 . The resulting low-pressure vapor is absorber into sorbate-lean (“strong”) absorbent 217 , which is cooled by coolant 220 , and the resulting sorbate-rich (“weak”) absorbent is pumped by pump 218 back to desorber 205 . The various exchanges may be shell and tube, coil in shell, or other known types.
[0035] Referring to FIG. 3, waste heat enters reclaimer 301 through entry port 302 . Heat transfer fluid is counter-currently circulated through steaming economizer 303 via pump 304 , and thence to the bottom of desorber column 305 , where phase separation occurs. The liquid phase enters internal heating coils 307 via inlet pipe 306 . Part of the llliquid phase is split off at splitter 312 and routed to pressure letdown 313 via solution heat exchanger 326 . The remainder heats the colder top end of column 305 , then supplies lower temperature heat to intermediate pressure desorber 323 , and then is recycled by pump 304 . Desorber vapor in pipe 308 is superheated in superheater 321 by counter-current heat exchange with the source heat, in parallel with exchanger 303 . Then the superheated vapor is work-expanded in expander 322 . The resulting low-pressure vapor is absorbed in low-pressure absorber 317 into the strong absorbent from letdown 313 , while absorption heat is removed by cooling heat transfer stream 320 . The resulting absorbent is pumped to intermediate-pressure in pump 318 , then split into a feed to intermediate-pressure desorber 323 and to intermediate-pressure absorber 324 . Vapor from intermediate-pressure desorber 323 is separated at separator 327 and then absorbed in intermediate-pressure absorber 324 . Pump 325 pumps the resulting weak absorbent back to high pressure for re-entry into column 307 . The FIG. 3 cycle incorporates both counter-current mass exchange columns ( 305 and 317 ) and co-current mass exchangers ( 323 and 324 ). Branch pump 328 improves the linearity of the temperature glide in column 307 .
[0036] Referring to FIG. 4, a two-pressure absorption cycle for a volatile absorbent such as aqua ammonia is depicted, adapted to be powered by combustion turbine waste heat, and further adapted to co-produce both shaft power and also refrigeration, for cooling the turbine inlet air or other cooling loads. Air compressor 451 is supplied air through filter 452 and cooling coil 453 . The compressed air supports combustion in combustor 454 , and the resulting hot pressurized combustion gas is work-expanded in turbine 455 . The combustion exhaust is ducted through exhaust duct 456 to optional heat recovery steam generator (HRSG) 457 , and thence to heat reclaiming section 401 , comprised of heating agent heater 403 , superheater 421 , and HRSG economizer 458 . The heating agent is supplied to the sump of column 405 where it phase separates. The liquid fraction enters internal exchanger 407 through entry port 406 , and part is split off at splitter 412 , and sent to letdown valve 413 , thence to low-pressure absorber column 417 . Low-pressure vapor from turbine 422 , evaporator 416 , and inlet cooler 453 is absorbed in low-pressure absorber 417 , with the colder portion of the heat of absorption removed by cooling stream 420 , and the warmer portion by high-pressure GAX (generator absorber heat eXchange) desorption coil 459 , from which the two-phase mixture is routed to a mid-height of column 405 . Part of the pumped weak absorbent from pump 418 is routed to GAX coil 459 , through split control valve 460 , and the remainder is routed through split controller 461 to solution-cooled rectifier 462 , and then sprayed into the top portion of column 405 . Pump 404 circulates the heating agent. The vapor split between turbine 422 and coolers 416 and 453 is controlled by valves 463 and 464 , respectively. As shown, those two vapors can be of differing purity, governed by the height of column 405 from which they are withdrawn. It is desirable to send quite high purity vapor to condenser 414 , for example at least 95% purity ammonia.
[0037] Referring to FIG. 5, low temperature heat supplied to reclaimer 501 heats heating agent in fin coils 503 . Then the two-phase heating agent is routed to the sump region of desorption column 505 , where the phases separate. The liquid phase enters entry port 506 of internal heat exchanger 507 , a succession of coils on vertically stacked vapor-liquid contact trays 549 . High-pressure vapor from column 505 is condensed in condenser 514 , subcooled in subcooler 515 , expanded in pressure letdown 519 , and evaporated in evaporator 516 , thus producing refrigeration and low-pressure vapor. That vapor is absorbed into the strong absorbent from splitter 512 and pressure letdown 513 , in low-pressure absorber column 517 . Column 517 has three sets of cooling coils, in top to bottom (hot to cold) order: High-pressure GAX desorption coil 559 (shown as occupying two trays 548 ); intermediate-pressure GAX desorption coil 547 , (shown as a occupying single tray 546 ); and the bottom coils for external cooling agent 520 , shown as occupying two trays 545 . The absorbent from low-pressure absorber 517 is pumped to intermediate-pressure by pump 518 , then split by valves 544 and 543 into feeds to an intermediate pressure GAX absorber 547 and the intermediate-pressure absorber 524 . The weak absorbent (water with high ammonia content) from intermediate-pressure absorber 524 is pumped to high pressure by pump 525 , and split into two streams by valves 542 and 541 ; the former stream being supplied sequentially to solution-cooled rectifier coil 540 and then to high-pressure GAX desorber coil 559 , and finally to column 505 as two-phase; and the latter directly injected into column 505 . Branch pump 528 supplies a mid-height of column 505 , thereby providing a more linear temperature glide in that column.
[0038] The three pressure cycles have similarity to prior art disclosures such as U.S. Pat. No. 5,097,676. The diabatic counter-current columns such as the desorber (distillation column) and low-pressure absorber (reverse distillation column) may be any known geometry. One preferred geometry is the diabatic multi-tray design with contact coils, such as disclosed in U.S. Pat. No. 5,798,086. Particularly preferred are those diabatic trays with same-direction liquid flow and minimal vapor mixing, as disclosed in International Publication No. WO 00/10696, dated Mar. 2, 2000.
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An absorption system powered by low temperature heat for producing at least one of refrigeration and power is disclosed, wherein a low-pressure drop heat reclaimer 1 reclaims heat from the source into a heating agent, which in turn supplies heat to the absorption cycle desorber 5 via internal coils 7. The extra temperature differential normally present in closed cycle heating systems is avoided by using the absorption working fluid as the heating agent, in an integrated system.
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REFERENCE TO PRIOR APPLICATIONS
This is a continuation application from Ser. No. 09/360,372, filed Apr. 28, 1999, U.S. Pat. No. 6,324,801, which is a continuation of application Ser. No. 08/716,507, filed Sep. 17, 1996, U.S. Pat. No. 5,953,874, which is a continuation of application Ser. No. 08/364,659, filed Dec. 27, 1994 (abandoned), which is a continuation of Ser. No. 07/976,611, filed Nov. 16, 1992, U.S. Pat. No. 5,392,575, which is a continuation of Ser. No. 07/745,995, filed Aug. 9, 1991 (abandoned), which is a continuation of Ser. No. 07/292,742, filed Jan. 3, 1989 (abandoned), and a continuation of Ser. No. 07/763,870, filed Sep. 19, 1991, U.S. Pat. No. 5,163,967, which is a continuation of application Ser. No. 07/507,002, filed Apr. 10, 1990 (abandoned), which is a continuation of application Ser. No. 07/319,852, filed Mar. 3, 1989 (abandoned), which is a continuation of application Ser. No. 07/101,832, filed Sep. 28, 1987 (abandoned), which is a continuation-in-part of application Ser. No. 06/926,291, filed Nov. 3, 1986, U.S. Pat. No. 4,724,642.
BACKGROUND OF THE INVENTION
This invention relates to outdoor residential constructions, and is particularly concerned with support devices for use in deck construction.
Various types of devices have heretofore been used for supporting and/or connecting building elements, such as horizontal beams, joists, stringers, posts and pillars, to a base slab, footing, foundation of block member. For example, such devices include anchor studs, metal brackets, or other supports or devices which are permanently embedded in the concrete in the manufacturing process of the blocks and which are required to make them functional. Such devices or additional components are used to provide vertical and lateral mechanical connection of building elements to a base or as components to other elements but do not have an individual identity or non-mechanical application which facilitates the inexpensive and convenient construction of a simple deck, such as a deck that may be built by the average home owner on unprepared and unleveled ground typical to a residential backyard.
SUMMARY OF THE INVENTION
According to the present invention and forming a primary objective thereof, a deck construction is provided including a novel construction support device, which amounts to an improvement over prior structures.
A more particular object of the invention is to provide a construction support device of the type described having a novel arrangement of recesses, walls, and sockets for receiving horizontal beams and the like, and also capable of receiving vertical pillars or posts, all in a variety of selected support connections not heretofore available.
Another object of the invention is to provide an embodiment of the invention comprising a plurality of integrated wall portions disposed in a zig zag pattern and forming one or more full width slots for receiving horizontal beams and the like and also forming a rectangular central socket for receiving a vertical pillar or post.
Another object of the invention is to provide a pier block of the type described having a novel arrangement of recesses and central socket for receiving horizontal two-inch thick ({fraction (1 1/2)}-inch nominal) surface supports, and also capable of receiving vertical wood posts without mechanical connections or additional components, all in a variety of selected support configurations not heretofore available.
In carrying out these objectives, a construction support device is provided for anchoring a beam or other element to the ground or other building site. The device includes a body having upper and lower portions. The lower portion rests on the building site, and the upper portion includes an open slot for holding a beam edgewise. The slot is formed by spaced-apart side walls. The side walls themselves include connected wall portions, which are integrally joined at right angles.
The slot includes a center socket portion that is adapted for securely holding the bottom end of a vertically oriented post. The center socket portion is formed by the side walls extending at right angles away from each other to form corner sections. The corner sections are spaced apart substantially further than the width of the open slot to provide substantial corner support to the post.
In some cases, the side walls which define the slot are part of spaced-apart projections which extend from the upper portion of the body. These projections can be integrally molded with the body to form a single-cast, one-piece block or pier. Alternatively, they may be formed of plastic or metal and suitably attached to a base.
The invention may be practiced with a pair of recesses emanating from the central socket portion to form a single slot which extends unobstructed across the entire breadth of the body. Alternatively, a second pair of recesses may be employed to form a total of two mutually perpendicular slots.
Support devices in accordance with the invention are particularly suited to the construction of residential decks. Horizontal, coplanar deck support members may be carried by a plurality of the foregoing support devices arranged in rows and columns. The horizontal deck support members are securely seated in the slots defined by the spaced apart side walls.
Where the deck is to be built on uneven ground, the horizontal members can be supported in a level attitude by a plurality of vertical support pillars. The bottom ends of the vertical support pillars are securely seated in one of the center socket portion, while their respective top ends bear the horizontal members in supporting engagement. The height of the vertical support pillars can vary to span the vertical distance between the uneven ground and the desired plane in which the horizontal support members reside.
In one embodiment, the construction support device of the invention comprises a body member having a lower surface which serves as a support on a base such as a slab, footing, or pier block. The body member has one or more recess means arranged to receive horizontal beams and the like. The body member also has a central socket for receiving a vertical pillar or post. The recess means are disposed on each of four sides of the body member at 90 degrees apart and communicate with the central socket and the exterior, the pairs of recesses opposite from each other being aligned whereby construction beams or the like can be laid therein in edge and/or end relation. Also, in such embodiment, the construction device has fastener-receiving means therein for attaching a beam or beams and a pillar together, and also for attaching the assembly to the base. In another embodiment, side edges of the body member at the recess openings have downturned projections shaped on a rear portion thereof to frictionally fit on top of pier blocks for anchoring the body member against lateral shifting.
In another embodiment, the construction support device of the invention is a single cast, one-piece pier block which comprises a body member serving as a capable support on unprepared and unleveled building sites, having localized dips, slopes and random level areas therein. The body member has a single recess means molded into the top surface capable of receiving horizontal deck surface support members and also capable of receiving the bottom end of a vertical wood post or pillar. The recess means can have particular dimensions for using conventional, existing lumber sizes and also such dimensions are such that the required integral strength of the block is maintained due to the manufacturing process and application without the necessity of using reinforcing bar steel or additional integral components. All of these features combine in a structural arrangement which automates and standardizes the manufacture and facilitates marketing, at a lower unit and resale cost, a deck that can be preplanned and pre-cut. Such a deck is simplified and inexpensive, and capable of construction by the average do-it-yourself homeowner who desires a deck on the unprepared and unleveled ground of a typical backyard.
The invention will be better understood and additional objects and advantages will become apparent from the following description taken in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top perspective view of a support device in accordance with a first embodiment of the invention;
FIG. 2 is a bottom perspective view of the device shown in FIG. 1;
FIG. 3 is a bottom perspective view of a construction support device in accordance with another embodiment of the invention;
FIG. 4 is a bottom perspective view of a construction support device in accordance with yet another embodiment of the invention;
FIGS. 5, 6 , 7 and 8 are perspective views showing various applications of the device of FIG. 1 in association with structural building elements;
FIG. 9 is a perspective view of a construction support device which includes lateral stabilizing elements in accordance with another embodiment of the invention;
FIG. 10 is a bottom perspective view of the construction support device of FIG. 9;
FIGS. 11 and 12 are perspective views showing various applications of the device of FIG. 9 in association with structural building elements;
FIG. 13 is a perspective view of a construction support device in accordance with another embodiment of the invention;
FIG. 14 is a bottom perspective view of the construction support device shown in FIG. 13;
FIG. 15 is a top perspective view of the construction support device shown in FIG. 13;
FIG. 16 is a top plan view of the construction support device shown in FIG. 13;
FIG. 17 is a perspective view of a construction support device in accordance with another embodiment of the invention;
FIG. 18 is a top perspective view of the construction support device shown in FIG. 17;
FIG. 19 is a top plan view of the construction support device show in FIG. 17;
FIGS. 20 and 21 are perspective views showing various applications of the device of FIG. 17 in association with structural building elements;
FIG. 22 is a perspective view of a deck construction in accordance with the invention employing the construction support device shown in FIG. 17; and
FIG. 23 is a perspective view of another deck construction in accordance with the invention employing the construction support device shown in FIG. 17 .
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
According to the present invention, a construction support device is provided which conveniently provides anchoring of a building element to a building site. As illustrated herein, the invention may be practiced in accordance with a first embodiment of FIG. 1, wherein the construction support device is securely attached to a concrete base or pier. The device of FIG. 1 can be inexpensively molded from plastic or stamped from metal and is simplified in its use and constructions.
Alternatively, the invention may be practiced in accordance with other embodiments, such as shown in FIGS. 13 and 17. There, the device is inexpensively poured from concrete together with a pier block to form a single cast, one-piece body. In either type of embodiment, the invention provides a new and advantageous support for securely seating construction members in either a horizontal or vertical orientation.
With reference first to FIGS. 5 through 8, the numeral 10 represents a base or pier block of conventional structure which is commonly used to support decks, carports, etc. This block is generally constructed of concrete and assumes different shapes. In most cases, the block is tapered to a lesser dimension toward the top. The top and bottom surfaces 12 and 13 , respectively, are flat.
FIGS. 1-8 illustrate a construction support device 14 in accordance with a first embodiment of the invention. Construction support device 14 may be molded, stamped, or otherwise formed from a tough plastic or metal. The body member of the device 14 includes a flat bottom wall 16 and four identically shaped or symmetrical upright quarter sections 18 . Each of the sections 18 comprises four zig zag panels 18 a joined integrally at right angles. These symmetrical quarter sections are shaped to form a recess or opening 20 on each side, with oppositely located recesses being laterally aligned. Also, with this quarter section construction, a square central socket 22 is formed. Laterally aligned recesses 20 provide a pair of full width slots open at the sides.
Each of the panel sections 18 a has one or more apertures 24 therein provided to receive fasteners, to be seen hereinafter, for securement of building elements to the device 14 . As seen in FIG. 2, cutouts 26 are provided in the bottom wall 16 for reducing the weight of the member as well as for conserving material. Also, apertures 28 are provided in the wall 16 for secured attachment of the member 14 to a base, such as to a block 10 , a concrete slab, or other support means.
FIGS. 5, 6 , 7 and 8 show various applications of the construction device 14 with building elements such as support members and pillars. FIG. 5 for example shows a horizontal decking surface support member 30 seated edgewise on the bottom wall 16 and extending fully through the device and out both side recesses 20 . FIG. 6 shows a support member 30 similarly supported as in FIG. 5 but also showing a right angle support member 32 extending through a 90 degree side recess 20 and abutted against the support member 30 . FIG. 7 shows a vertical pillar 34 supported on the device 14 and fitted in the central socket 22 . FIG. 8 shows a pillar 34 similarly fitted in the socket 22 as in FIG. 7 but also showing side beams 32 extending in from all four of the side recesses. These members may simply be fitted in the respective recesses 20 or socket 22 . Preferably, however, secured attachment to the member 14 is accomplished by fasteners 36 extending through the apertures 24 . Also, device 14 can first be secured to the base member 10 by fasteners extending through the apertures 28 .
FIG. 3 is a bottom perspective view of a construction device 14 ′ having a bottom wall 16 and side walls 18 in an arrangement similar to that shown in FIGS. 1 and 2. This structure, however, is formed (such as by integral molding) with a plurality of depending foot member 38 . Four of such foot members are shown, as well as a central foot member, but any number of such foot members maybe provided. In the FIG. 3 embodiment, the foot members 38 are hollow whereby long fasteners can be inserted down from the top through the wall 16 and into a base for secured attachment of the construction device 14 ′ to the base. FIG. 4 shows a structure similar to FIG. 3 except that the outer foot members 38 ′ are solid and not hollow. This embodiment may be employed in circumstances where it is not necessary to use vertical fasteners around an outer portion of the member.
FIGS. 9-12 illustrate an embodiment of the invention employing means for anchoring the body member against lateral shifting. In this embodiment, the body member 14 ″ is the same as that shown in FIG. 1 with respect to quarter panel sections 18 a and their formation of aligned recesses 20 and central socket 22 . To accomplish the lateral anchoring feature, the outermost panel section 18 a of each quarter section has a depending projection or lip 40 defined by a bottom wall portion 42 integral with side extensions 44 and a rear wall portion 46 . Rear wall portion 46 preferably angles outwardly toward the bottom to coincide with the angle of the side surfaces of pier block 10 . Rear wall portion 46 can extend at a desired angle, so as to have flush engagement with pier block sides or varying shape.
FIGS. 11 and 12 show application of the device 14 ″ of FIG. 9 to a pier block. In such arrangement, the device 14 ″ and the building elements therein are anchored or locked against lateral shifting. Fasteners extending through the bottom wall of the device are not necessary, although such fasteners can be used if desired. The cross dimension of the device between rear wall portions 46 can be preselected according to the size of the pier block so that a snug or frictional fit is provided.
Referring to FIGS. 13-21, it will be seen that the device 14 may be made of concrete and integrally molded into the upper surface 12 ′ of a pier block such as pier block 50 . As shown in FIGS. 13-16, the four upright quarter sections 18 ′ include zig-zag walls 18 a ′ which project from flat bottom wall 16 ′. Recesses 20 ′ define two perpendicular slot portions extending across the full width of upper surface 12 ′. Zig-zag walls 18 a ′ also define the four corners of a square central socket 22 ′.
With reference to FIGS. 17-21, the concept of the invention can also utilize a pier block 50 ′ having a central socket portion 22 ′ and only two equal narrower recesses 20 ′ which extend inward from outer edges of two opposite sides of the top surface of the block 50 ′ and lead into the central socket portion, as best shown in FIG. 18 . The two narrower recesses 20 ′ form but a single slot for receiving a horizontal decking surface support member 30 which also passes through the central socket portion 22 ′, as shown in FIG. 20 . The central socket portion 22 ′ is for receiving vertical pillar supports 34 , independent of the two equal narrower recesses 20 ′, as shown by FIG. 21 . The horizontal decking surface support members 30 and vertical pillar support members 34 being mutually exclusive to each other in the recess of block 50 ′ and also mutually interchangeable with each other in the same recess of the same block 50 ′.
The combination of slots and sockets allows a support in accordance with the invention to accommodate both vertical and horizontal beams, and is particularly well-suited for constructing decks on unprepared and unleveled building sites, two examples of those being shown in FIGS. 22 and 23. Such decks, by using the present block, are extremely simplified in their construction and can be supplied in pre-planned, pre-cut units. Other advantages also exist in the structure, as will be apparent hereinafter.
The deck shown in FIG. 22, designated by reference numeral 52 , comprises the pier blocks 50 ′ as the base or ground support for the deck and can have such lumber as two-inch thick (1½ inch thick nominal) horizontal decking surface support member 30 received by the two equal narrower portions 20 ′, also passing through the central socket portion 22 ′ when the vertical pillar support 34 is not in the block 50 ′, those members 30 then supporting the deck surface structure 54 which is nailed in place and those blocks 50 ′ directly receiving member 30 being on localized high or level ground within an unprepared and unleveled building site.
The deck shown in FIG. 23, designated by the numeral 56 , similarly uses some pier blocks 50 ′ as described above and also illustrates the use of some blocks 50 ′ as the base or ground support for vertical pillar supports 34 set in the central socket 22 ′ when the member 30 is not in block 50 , member 34 then providing support to member 30 when member 30 is not directly received by block 50 due to localized variations of the ground within an unprepared and unleveled building site. A deck support member 30 can also be fastened to a building 60 , as shown in FIG. 23 .
The particular structure of the manufactured pier blocks 50 and 50 ′ makes it possible to construct an extremely simplified deck and one which can be pre-planned and pre-cut if desired. That is, such lumber as 2-inch thick deck support members 30 and vertical wood pillars 34 which can be used therewith comprise conventional existing material, namely, the two-inch thick deck support members 30 can comprise 2×6's or 2×4's and pillars 34 can comprise 4×4's.
The two equal narrower recesses 20 ′ can be 2 inches deep and have a width of 1¾ inches. This latter dimension would receive conventional finished 2×6's (1½ inches thick) and 2×4's (also 1½ inches thick). 2×6's and 2×4's have finished height dimensions of 5½ and 3½ inches, respectively, whereby the deck support members, whether 2×6's or 2×4's, project to a minimum necessary height above the top surface of the blocks 50 when seated in the recess for supporting the decking thereon.
The central socket portion 22 ′ can be 2 inches deep, similar to the recess portion 20 ′. Such socket is square, and can have dimensions of 3¾ inches for receiving a conventional finished 4×4 (3½ inches square) lumber support pillar. The vertical pillar becomes sufficiently fixed in socket portion 22 ′ in the block for deck construction purposes, as does the deck horizontal support member in the two narrower portions 20 ′, also being within the central socket portion 22 ′ when the member 34 is not in the block 50 , for lateral stability.
Pier blocks 50 and 50 ′ are designed to provide support to a deck on unleveled or unprepared building sites with no additional components required. For this purpose, the blocks 50 and 50 ′ are tapered to a larger dimension toward the bottom. The top and bottom surfaces are flat and square. The enlarged bottom surface allows the block to serve as its own footing. When two of such recesses 20 ′ are provided, they are standardly aligned across the block. Furthermore, the width of these recesses is less than one-third the width of the block at the top, thus maintaining lateral integral strength of the block. This arrangement maintains a strong concrete block without the necessity of re-bar reinforcement and thus contributes to manufacture of a pier block and deck structure in a pre-planned and pre-cut unit which is also sufficiently simplified in its use, standardized in its manufacture, and sufficiently inexpensive for deck construction by the average do-it-yourself homeowner.
Since the recess can be two inches deep, the recesses of the pier blocks 50 and 50 ′ of FIGS. 13 and 17 automatically and non-mechanically center the horizontal decking surface support member 30 and vertical pillars 34 in the pier block (FIGS. 20 and 21) and automates connection and securement of these support members to the pier block for deck constructions 52 and 54 shown in FIGS. 22 and 23. Mounted engagement of the horizontal surface support members and vertical pillars with the block is accomplished without metal-brackets or embedded connectors thus allowing individual blocks of a deck construction on unleveled and unprepared building sites to be adjusted without the need of any disassembly of the deck (i.e. removing bolts, nails or screws). Also, the recess of the pier blocks 50 and 50 ′ maintains horizontal and vertical members in parallel which is critical in construction of the deck.
It is to be understood that the forms of our invention herein shown and described are to be taken as preferred examples of the same and that other changes in the shape, size and arrangement of parts may be resorted to without departing from the spirit of our invention or the scope of the following claims.
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A deck construction including a plurality of supports for anchoring deck construction elements to a building site. The supports include a body (which may be an integrally molded concrete pier) having upper and lower portions. The upper portion includes at least one slot for seating a horizontally oriented construction member. The slot includes a center socket portion having four extended corners for seating the bottom end of a vertically oriented construction member. The slot and center socket are defined by connecting wall portions which may be integral to the body or may be of plastic or metal and suitable secured to the body. In some cases, two mutually perpendicular slots are provided.
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BACKGROUND
[0001] 1. Field of Invention
[0002] The present invention relates to oil and gas production. More specifically, the present invention relates to a tool that creates a shockwave in a wellbore to “back-off” threads engaged in a threaded couplings within a tubular string.
[0003] 2. Description of Prior Art
[0004] Typically, tubulars are connected together by threaded couplings to form a string that is suspended and cemented in a wellbore to create a casing for the wellbore. From time to time, the casing string may need to be removed from the wellbore and the threaded couplings are decoupled at surface. In some instances while removing the casing it may become wedged within the wellbore; further complicating string removal, while still downhole, one of the threaded couplings may resist detachment under an applied torque to become immovable. The immovable coupling is sometimes unseated by directing a shockwave at the coupling site to break loose the threaded connection.
[0005] A typical prior art tool used to create this shockwave consists of multiple strands of detonator cord wrapped around a shot rod in a rope-like fashion and wrapped with friction tape. Generally this tool employs a detonation cord having HMX (octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine), which can withstand operating temperatures of 400 degrees Fahrenheit for only about an hour. While a detonating cord having HNS (1,3,5-Trinitro-2-[2-(2,4,6-trinitrophenyl)ethenyl]benzene) can operate at temperatures above those limiting use of HMX detonator cord, HNS detonating cord cannot side detonate and thus is not utilized in the above described prior art tool. Also, operating pressure of typical prior art is limited to 20,000 psi due to the use of exposed (to wellbore fluids) interface between detonator and detonating cord.
SUMMARY OF THE INVENTION
[0006] The present disclosure involves a method of unseating a threaded connection that connects sections of wellbore tubing. In an example the method uses a tool that includes a housing, a shaped charged located inside the housing, an HNS detonating cord and an energetic material attached to the steel housing. The tool is placed near the threaded connection, where it is detonated, creating a shockwave that contacts the threaded connection with sufficient force to unseat the threaded connection.
[0007] Also disclosed is a method of an operation in a wellbore that includes inserting an amount of reactive material within a string of wellbore tubular segments, where a threaded connection joins upper and lower adjacent tubular segments. A shockwave is generated by initiating the reactive material that unseats the threaded connection by directing the shockwave towards the threaded connection. The upper tubular segment is rotated thereby eliminating the threaded connection and the upper tubular segment is removed from the wellbore. In an example, the reactive material is initiated by a jet from a shaped charge that terminates proximate an outer surface of the reactive material. In one alternative embodiment, the reactive material includes a high explosive, wherein initiating the high explosive causes the high explosive to detonate. Optionally, the reactive material is a low explosive, wherein initiating the low explosive causes the low explosive to deflagrate. In another alternative, the reactive material includes a combustible material, wherein initiating the combustible material causes the combustible material to combust. Alternatively, initiating the reactive material includes using a detonation cord having HNS to detonate a shaped charge thereby forming a jet, and directing the jet at the reactive material. The pressure can be at least about 30,000 pounds per square inch within the string of tubular segments. At least a portion of the HNS detonating cord can be maintained at a temperature of at least about 480° F. and for a time up to about 1 hour.
[0008] Also disclosed herein is an embodiment of a back off tool for use in a downhole tubular. In one example the back off tool includes a body selectively suspended in the downhole tubular by attachment to a deployment member. A reactive material is included adjacent the body for generating a shockwave to unseat an immovable threaded connection between adjacent tubular segments. An initiator is provided in selective communication with the deployment member and in selective initiating communication with the reactive material. In one example, the initiator is a shaped charge that forms a jet to initiate a reaction in the reactive material. Alternatively, a detonating cord having HNS can be included with the back off tool. In an example embodiment, the body and the reactive material each include an axis, and the reactive material is disposed adjacent an end of the body and positioned so that the axis of the reactive material is substantially parallel with the axis of the body. Alternatively, the reactive material can be a high explosive.
BRIEF DESCRIPTION OF DRAWINGS
[0009] Some of the features and benefits of the present invention having been stated, others will become apparent as the description proceeds when taken in conjunction with the accompanying drawings, in which:
[0010] FIG. 1 is a side sectional view of an embodiment of a back-off tool in accordance with the present disclosure.
[0011] FIG. 2 is a partial cutaway side view of a back-off operation.
[0012] FIG. 3 is a partial cutaway side view of a shockwave striking the threaded coupling.
[0013] FIG. 4 is a partial cutaway side view of a wellbore as the upper casing section is removed.
[0014] FIG. 5 depicts in a side sectional view an alternate embodiment of a back-off tool in accordance with the present disclosure.
[0015] While the invention will be described in connection with the preferred embodiments, it will be understood that it is not intended to limit the invention to that embodiment. On the contrary, it is intended to cover all alternatives, modifications, and equivalents, as may be included within the spirit and scope of the invention as defined by the appended claims.
DETAILED DESCRIPTION OF INVENTION
[0016] The method and system of the present disclosure will now be described more fully hereinafter with reference to the accompanying drawings in which embodiments are shown. The method and system of the present disclosure may be in many different forms and should not be construed as limited to the illustrated embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey its scope to those skilled in the art. Like numbers refer to like elements throughout.
[0017] It is to be further understood that the scope of the present disclosure is not limited to the exact details of construction, operation, exact materials, or embodiments shown and described, as modifications and equivalents will be apparent to one skilled in the art. In the drawings and specification, there have been disclosed illustrative embodiments and, although specific terms are employed, they are used in a generic and descriptive sense only and not for the purpose of limitation. Accordingly, the improvements herein described are therefore to be limited only by the scope of the appended claims.
[0018] FIG. 1 depicts, in a cross-sectional view, an embodiment of a portion of a back off tool 20 that can be used in high pressure and high temperature applications. In the example of FIG. 1 , the back off tool 20 includes an annular gun tube 22 shown containing a shaped charge 24 and oriented orthogonal to an axis A X of the gun tube 22 . The shaped charge 24 is shown having an open end set within an opening 25 formed through a side wall of the gun tube 22 . In the example of FIG. 1 , the gun tube 22 is enclosed in a tubular housing 26 that, in an example embodiment, may be formed from steel. A detonating cord 28 is further included with the embodiment of the back off tool 20 of FIG. 1 . The detonating cord 28 , which in an example embodiment may be an HNS detonating cord, is shown extending along the gun tube 22 and routed so that its path runs adjacent an end of the shaped charge 24 . A sleeve 30 is shown encasing the outer surface of the tubular housing 26 . The sleeve 30 may be formed from an energetic material that when initiated reacts and generates a shockwave. Materials for the sleeve 30 can include any material capable of generating a shockwave, examples include an oxidizer, a propellant, a high explosive, e.g. HMX, RMX, HNS, a low explosive, a combustible material, and combinations thereof.
[0019] The material for the sleeve 30 can detonate, deflagrate, combust, or a combination thereof. In an example, the definition of detonation describes a reaction that can propagate through the material being detonated at the sound speed of the material. In a further example, detonation describes a reaction or decomposition of an explosive that, typically in response to a shock wave or heat, forms a high pressure/temperature wave. Example velocities of the high pressure/temperature wave can range from 1000 m/s to in excess of 9000 m/s. In an example, the definition of deflagration describes a rapid autocombustion of a material, such as an explosive. Generally, explosives that detonate are referred to as high explosives and explosives that deflagrate are referred to as low explosives. In an example, combustion describes an exothermic reaction of a material that can produce an oxide.
[0020] In one example of operation, and as provided in FIGS. 2-4 , a detonation wave is initiated in the detonating cord 28 that transfers a shock wave to and detonates the shaped charge 24 . As will be discussed in further detail below, in one example embodiment of the back off tool 20 , a jet (not shown) formed from detonation of the shaped charge 24 penetrates the housing 26 and the sleeve 30 reacting the sleeve 30 , which provides the necessary shockwave for the back-off operation. In an example embodiment, the jet does not extend past the sleeve 30 , or extends slightly past.
[0021] Referring now to FIG. 2 , shown in a side sectional view is an embodiment of the back off tool 20 . In the embodiment of FIG. 2 , the back off tool 20 is suspended by a wireline 32 shown being reeled from and controlled by a surface truck 33 . Alternatively, the wireline 32 can be threaded through a wellhead assembly (not shown) disposed on the surface. The back off tool 20 and wireline 32 are inserted within a string of wellbore casing 34 that line a wellbore 35 . The casing string is made up of segments of casing 34 , each segment having threaded ends that threadingly couple together to form a threaded connection 36 . More specifically in the example of FIG. 2 , the back off tool 20 is suspended adjacent a threaded connection 36 that is immovable. For the purposes of discussion herein, and as described above, a threaded connection 36 that is immovable describes a threaded connection 36 that resists decoupling.
[0022] In the example embodiment of FIG. 3 shown in side partial sectional view is an example embodiment where the shaped charge 24 in the back off tool 20 has been detonated that in turn initiates detonation of the sleeve 30 . When the sleeve 30 is detonated it creates a shockwave 38 that propagates through the threaded connection 36 , as shown in FIG. 3 . The force of the shockwave 38 can remove stresses in the threaded connection 36 joining upper and lower segments of casing 34 U , 34 L thereby allowing the threaded connection 36 to back-off as torque is applied to the upper segment of casing 34 U . Thus continued application of torque to the upper segment casing 34 U rotates the upper segment of casing 34 U decoupling upper and lower threads 37 U , 37 L to eliminate the threaded connection 36 that couples the upper and lower segments of casing 34 U , 34 L . As shown in side sectional view in FIG. 4 , once decoupled, the upper segment of casing 34 U can be detached from the lower segment of casing 34 L and removed from the wellbore 35 . In an optional embodiment, the back off tool 20 includes more than one sleeve 30 so that a shock wave can be generated at a first depth, the back off tool 20 raised or lowered to a second depth, and another shock wave generated by initiating the more than one sleeve.
[0023] An alternate embodiment of a portion of a back off tool 20 A is shown in a side sectional view in FIG. 5 . The back off tool 20 A of FIG. 5 includes a shaped charge 24 A suspended from a length of detonating cord 28 A shown disposed inside a generally cylindrically shaped housing 26 A. Disposed adjacent to a lower end 39 of the housing 26 A is a substantially cylindrically shaped amount of reactive material 40 oriented generally coaxial with the housing 26 A. In an example embodiment, the reactive material 40 includes the same or similar material of the sleeve 30 as described above. The shaped charge 24 A of FIG. 5 is oriented so that when detonated any jet resulting from the shaped charge 24 A is directed towards the lower end 39 and reactive material 40 , rather than a side radial wall as illustrated in the example of FIG. 1 . In the example embodiment of FIG. 5 , an axis A H of the housing 26 A is shown to be substantially coaxial with an A EM of the reactive material 40 . Embodiments exist as well where the axes A H , A EM are substantially parallel. Optionally, the reactive material 40 may be encased in a jacket 42 for protecting the reactive material 40 during the trip downhole. Operation of the back off tool 20 A of FIG. 5 is similar to the operation described above; that is, the back off tool 20 A is inserted into a tubular string and the reactive material 40 is reacted, such as by detonating the shaped charge 24 A. An ensuing shock wave, not shown, transfers energy to an immovable threaded connection so that the connection can be decoupled.
[0024] The present invention described herein, therefore, is well adapted to carry out the objects and attain the ends and advantages mentioned, as well as others inherent therein. While a presently preferred embodiment of the invention has been given for purposes of disclosure, numerous changes exist in the details of procedures for accomplishing the desired results. For example, the back off tool 20 and its alternate embodiments can be disposed in other downhole tubulars, such as production tubing strings, caissons, risers, and the like. These and other similar modifications will readily suggest themselves to those skilled in the art, and are intended to be encompassed within the spirit of the present invention disclosed herein and the scope of the appended claims.
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A method for unseating a threaded connection of wellbore tubing within the wellbore. The method utilizes a back-off tool which consists of a tubular metal housing, a shaped charge and HNS detonating cord within the housing, and an explosive material attached to the housing. The back-off tool is detonated near the threaded connection, creating a shockwave that strikes the threaded connection with sufficient force to unseat the connection.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a national stage entry of PCT/AU2010/001689, filed Dec. 15, 2010, which claims priority to Application No. AU 2010100030, filed Jan. 12, 2010.
FIELD OF THE INVENTION
The invention relates to quilting. In particular, the invention relates to a quilting frame for vertically supporting quilt components during hand arrangement and assembly of a quilt.
BACKGROUND TO THE INVENTION
Quilting has been practiced throughout the world for many centuries. Quilts were used originally as blankets or bed covers to keep people warm. Today, quilts are usually made by small business manufacturers or as a hobby by individuals or quilting groups, and are often intended to function as decorative bed covers, wall hangings, or as framed works of art. A quilt generally includes a backing layer, interior batting material, and decorative top layer comprising small fabric panels stitched together.
Generally a quilt is made by first stretching a backing layer over a solid horizontal surface such as a table or the floor, or a horizontal rigid frame in the case of manufacturers or more prolific hobbyists. The backing layer is temporarily attached to the horizontal surface or frame using tapes or various types of clamping mechanisms. Batting material is then applied over the backing layer. Finally the decorative top layer, comprising individual fabric panels that have been stitched together previously, is applied over the batting material and all three layers are pinned or tacked together to stabilise positioning of the layers prior to final stitching of the quilt.
The prior art includes various types of quilting frames for use in hand quilting and machine quilting, including the following:
U.S. Pat. No. 6,839,992 describes a quilting frame apparatus. The apparatus comprises concentric rectangular outer and inner frames. The outer frame is constructed from four elongate members attached in a mortise-and-tenon arrangement at each of its four corners and secured by wingnuts. The quilting frame may be adjusted at different angles to suit the user.
U.S. Pat. No. 6,757,996 describes a portable multiple use quilting frame system. The system is intended for both free hand and machine quilting and includes a pair of frame ends supported by three rods. The rods hold material to be quilted. As the quilting process progresses, the material is wound onto a take-up rod.
U.S. Pat. No. 7,581,343 describes a quilt display frame. The frame includes a sheet of flexible material having a peripheral edge with a plurality of sleeves. Poles are placed within the sleeves and are connected to one another to form a frame member. A connector is employed that includes a pair of tubes that are connected to each other by a bridge and a pair of legs are clipped onto the poles to support the frame on a surface in an upright position. A surface of the sheet is then used for holding patches for previewing a quilt design.
U.S. Pat. No. 6,209,240 describes a textile holding frame. The frame includes a pair of side members and two or more lateral members extending between the sides to define a generally rectangular configuration. One embodiment uses stationary frame members with retainers for material retention and/or tensioning, and another embodiment uses rotating frame members to provide desired tensioning.
U.S. Pat. No. 6,151,816 describes a portable quilting frame assembly. The assembly includes two complementary support structures each of which includes a base member, an elevation member, and a fulcrum member. The two complementary support structures are coupled by a cross member which spans the distance between the two complementary support structures. Coupled to each of the fulcrum members at a fulcrum end is a rail assembly for tensioning material.
U.S. Pat. No. 5,987,789 describes a stitchery stand and frame assembly. The assembly includes a stand having spaced posts which are connected together at their lower ends by a box assembly into which a tongue is slidably mounted. A frame unit connects the upper end of the posts. The frame unit includes a working frame wherein the side members and spanning members are connected together by being inserted into corner connectors. A fabric is mounted in a peripheral groove of the working frame.
U.S. Design Pat. No. 257,041 illustrates a quilting frame including two saw-horse members connected by rotatable horizontal rails.
U.S. Pat. No. 4,665,638 describes a quilting frame designed to stretch and hold material while hand stitching bed quilts. It consists of a pair of legs that are adjustable in height and are free-standing when three rods for holding material are removed from the frame. A hand crank is provided for rotating the rods and a locking device is also employed for preventing rotation. Further tensioning is provided by a horizontal tensioning mechanism pivotal on link rods attached to one of a pair of horizontal rods.
U.S. Pat. No. 4,736,535 describes a vertical embroidery frame. The frame may be attached to a stationary surface such as a wall panel and includes multiple securing means to provide a horizontal adjustable retaining area at work space height, and an area above for vertical storage of a quilt. As each portion of a quilt is completed at the horizontal work station, the quilt can be stored and displayed vertically until it is complete.
However, the prior art fails to disclose a system for efficient hand arrangement of various sized quilts using a vertical frame that provides easy access to both sides of a quilt. There is therefore a need for an improved vertical quilt basting frame.
OBJECT OF THE INVENTION
It is an object of the invention to overcome or at least alleviate one or more of the deficiencies of the prior art and/or provide the consumer with a useful or commercial choice.
DISCLOSURE OF THE INVENTION
In one form, although it need not be the only or indeed the broadest form, the invention resides in a vertical quilt basting frame, comprising:
four frame members defining a rectangle;
at least one leg member extending from at least one of the frame members; and
a plurality of fabric side panels attached to each of the four frame members, wherein the fabric side panels define a workspace window inside of the rectangle defined by the aforementioned four frame members.
Preferably, the four frame members define a part of one side of a box frame.
Preferably, the plurality of fabric side panels define a rectangular workspace window.
Preferably, the frame further comprises a plurality of fabric reducing panels attached to the plurality of fabric side panels, wherein the plurality of fabric reducing panels define a reduced size workspace window.
Preferably, the plurality of fabric side panels consists of a single piece of material.
Preferably, the frame further comprising a quilt backing material pinned to the fabric side panels.
Preferably, the frame further comprises:
four additional frame members defining a second rectangle and defining a second part of a second side of the box frame; and
a second plurality of fabric side panels attached to each of the four additional frame members, wherein the second plurality of fabric side panels define a second workspace window inside of the second rectangle.
Preferably, the first rectangle is connected to the second rectangle by cross members.
Preferably, the four frame members comprise lightweight extruded aluminium hollow sections.
Preferably, the frame members are connected together using plastic connectors.
BRIEF DESCRIPTION OF THE DRAWINGS
To assist in understanding the invention and to enable a person skilled in the art to put the invention into practical effect, preferred embodiments of the invention will be described by way of example only with reference to the accompanying drawings, wherein:
FIG. 1 is a perspective view illustrating a vertical quilt basting frame and plurality of fabric side panels according to an embodiment of the present invention;
FIG. 2 is a perspective view of the vertical quilt basting frame of FIG. 1 illustrating the frame without a plurality of fabric side panels;
FIG. 3 is a front view of the vertical quilt basting frame of FIG. 1 further illustrating positioning of the plurality of fabric side panels;
FIG. 4 is a front view of the vertical quilt basting frame of FIG. 1 further illustrating the use of fabric reducing panels, according to an embodiment of the present invention;
FIG. 5 is a perspective view of the quilting frame of FIG. 1 illustrating how additional fabric side panels can be attached to additional frame members, according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
A single embodiment of the present invention is presented in the drawings as an improved vertical quilt basting frame. Elements of the invention are illustrated in concise outline form, showing only those specific details that are necessary to understanding the embodiments of the present invention, but so as not to clutter the disclosure with excessive detail that will be obvious to those of ordinary skill in the art in light of the present description.
With reference to FIG. 1 , a perspective view illustrates a vertical quilt basting frame 100 according to an embodiment of the present invention. The frame 100 includes four frame members consisting of two horizontal members 105 , 115 and two vertical members 110 , 120 that define a rectangle. Leg members 125 extend from a lower end of the frame 100 and support the frame 100 above the ground. Additional frame members 130 , 135 , 140 , 145 define a second rectangle.
A plurality of fabric side panels 150 , 155 , 160 , 165 are attached to each of the four frame members 105 , 110 , 115 , 120 and define a workspace window 170 inside the rectangle defined by the frame members 105 , 110 , 115 , 120 . To provide an example of comparative scale of the frame 100 , a person 175 is illustrated standing inside of the frame 100 . For example, the frame 100 may be 1700 mm wide, 1800 mm high and 550 mm deep. The person 175 thus is provided easy access to a rear side of the workspace window 170 .
Referring to FIG. 2 , a perspective view illustrates the vertical quilt basting frame 100 without the plurality of fabric side panels 150 , 155 , 160 , 165 . As shown, the additional frame members 130 , 135 , 140 , 145 define a second rectangle, which in conjunction with frame members 105 , 110 , 115 , 120 and cross members 205 , 210 , 215 , 220 provide stability and define a box frame.
The frame members 105 , 110 , 115 , 120 , 130 , 135 , 140 , 145 , leg members 125 and cross members 205 , 210 , 215 , 220 can be manufactured from various materials such as commercially available lightweight extruded aluminium hollow sections. Plastic connectors 200 are then used to connect the frame members 105 , 110 , etc. and cross members 205 , 210 , etc. together. As will be understood by those having ordinary skill in the art, various alternative materials, shapes and types of members and connectors may also be used.
Referring to FIG. 3 , a front view of the vertical quilt basting frame 100 further illustrates positioning of the plurality of fabric side panels 150 , 155 , 160 , 165 . The fabric side panel 150 is shown in an unfolded and unattached arrangement. Tabs 305 , 310 , 315 then fold around, respectively, the frame members 105 , 110 , 120 . A final look of the side panel 150 is then similar to the look of the side panel 160 shown in FIG. 3 .
During use of the frame 100 , a quilt backing material (not shown) is pinned to the fabric side panels 150 , 155 , 160 , 165 . Generally, the quilt backing material is a single backing sheet of fabric that is slightly larger than the area of the workspace window 170 . A user, such as the person 175 , is then provided convenient and unobstructed access to both a front side and a back side of the backing material. After the backing sheet is adequately attached, batting material or wadding and decorative top layer comprising pre-stitched fabric panels are pinned to the backing material. For example the layers of a quilt being produced, commonly referred to as a “quilt sandwich”, can be pinned together at approximately 10 cm intervals both horizontally and vertically. After a user is satisfied that the layers are correctly aligned and pinned together correctly, the quilt sandwich can be removed from the frame 100 and completed by sewing in a usual manner.
Referring to FIG. 4 , a front view of the vertical quilt basting frame 100 further illustrates the use of fabric reducing panels 405 , 410 , 415 , 420 , according to an embodiment of the present invention. To enable quilting of smaller quilts having an area smaller than the workspace window 170 , the fabric reducing panels 405 , 410 , 415 , 420 can be attached to the fabric side panels 150 , 155 , 160 , 165 . For example, tabs 425 can be folded around the frame members 105 , 110 , 115 , 120 to secure the fabric reducing panels 405 , 410 , 415 , 420 in place and define a reduced size workspace window 430 . As described above, quilt backing material (not shown) is then pinned to the fabric reducing panels 405 , 410 , 415 , 420 .
Referring to FIG. 5 , a perspective view illustrates how additional fabric side panels 505 , 510 , 515 , 520 can be attached to the additional frame members 130 , 135 , 140 , 145 , according to an embodiment of the present invention. That enables two quilts to be hung simultaneously from the vertical quilt basting frame 100 , and includes convenient access to the front and back sides of both quilts.
Embodiments of the present invention thus include the following advantages:
Vertical orientation of a quilting frame uses less floor space, allows for easy access to both sides of a quilt, enables gravity to assist in evening out layers of a quilt, and provides reduced strain on a user's body as kneeling and bending to access a quilt are not required. Lightweight construction allows for easy moving of the quilting frame with or without a quilt attached. Two or more quilts can be assembled simultaneously using opposing sides of a box frame to support the quilts. Quilts of varying sizes can be assembled using various sized workspace windows. Frames of the present invention also can be used to display one or more completed quilts.
In this patent specification, adjectives such as front and back, top and bottom, etc., are used solely to define one element or method step from another element or method step without necessarily requiring a specific relative position or sequence that is described by the adjectives. Words such as “comprises” or “includes” are not used to define an exclusive set of elements or method steps. Rather, such words merely define a minimum set of elements or method steps included in a particular embodiment of the present invention.
The above description of various embodiments of the present invention is provided for purposes of description to one of ordinary skill in the related art. It is not intended to be exhaustive or to limit the invention to a single disclosed embodiment. As mentioned above, numerous alternatives and variations to the present invention will be apparent to those having ordinary skill in the art. Accordingly, while some alternative embodiments have been discussed specifically, other embodiments will be apparent or relatively easily developed by those of ordinary skill in the art. Accordingly, this patent specification is intended to embrace all alternatives, modifications and variations of the present invention that have been discussed herein, and other embodiments that fall within the spirit and scope of the claims.
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A vertical quilt basting frame ( 100 ) enables an improved quilting experience. The frame ( 100 ) includes four frame members ( 105, 110, 115, 120 ) defining a rectangle. At least one leg member ( 125 ) extends from at least one of the frame members ( 105, 110, 115, 120 ). A plurality of fabric side panels ( 150, 155, 160, 165 ) are attached to each of the four frame members ( 105, 110, 115, 120 ), wherein the fabric side panels ( 150, 155, 160, 165 ) define a workspace window ( 170 ) inside of the rectangle.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part application of U.S. patent application Ser. No. 241,486, filed Mar. 09, 1981 and entitled "Improved Liquid Dispenser," now abandoned.
TECHNICAL FIELD
The present invention relates generally to liquid dispensers and applicators of the type wherein a premeasured supply of liquid is disposed in an applicator handle and selectively dispensed through the applicator. The invention has particular applicability in the field of aseptic surgery preparation as a pre-operative surgical scrub system for use in the operating room.
BACKGROUND OF THE INVENTION
As part of the preparation for many surgical procedures, for example, a surgical operation, it is required that the affected area of the patient be antiseptically cleansed. This requirement has existed for a very long time and the procedures used to meet this requirement have changed dramatically. Originally, jars or cans of gauze sponges or cotton balls were packed, sterilized, and placed in operating rooms. These sponges and/or cotton balls were used for scrubbing procedures by holding them with sterile forceps and dipped into a pan containing a soap or antiseptic solution. After the cotton ball or sponge is saturated with the solution, it is wiped on the appropriate area. This procedure was inconvenient for a number of reasons. First, it tended to create a mess due to the open pan and the constant back and forth travel of the sponge or cotton ball between the pan and the patient. Further, the procedure took an undesirably long time and resulted in an inordinate amount of liquid being lost due to splashing, scattering, and waste. Moreover, this procedure tended to use more antiseptic solution than necessary because most medical personnel mistakenly believed that the antiseptic effect was more readily obtained if more solution was used. This is not true and, quite to the contrary, it has been noted that excess solution tends to form pools or puddles under the patient resulting in iodine burn.
Apart from the disadvantage of the forcep and sponge or cotton ball procedure, the lack of standardization of techniques resulted in considerable confusion. Eventually, certain standards did develop. Specifically, the area of incision on the patient's body must be cleaned thoroughly with a scrub or soap solution for a period between 3 to 10 minutes. Most surgical operations, other than orthopaedic surgery, require 3 minutes of scrubbing time; orthopaedic surgery requires 10 minutes of scrubbing time due to the increased risk of infection. After the scrubbing procedure, the area is dried with a sterile wipe and antiseptic solution is applied. For some procedures, other than orthopaedic surgery, the scrub portion of the procedure is eliminated and only the antiseptic solution is applied. In either case, the standard procedure for applying either the scrub or the antiseptic solution involves starting from the middle of the treated area and proceeding outward in circular or square motions, it being important never to return to a previously treated area with the same surface of the sponge. The sponge may be turned over and the same procedure started once again; that is, as long as a new sponge surface area is used, an already-prepared skin area may be re-contacted. However, one should never apply a used or contaminated sponge surface that has already been in contact with a cleanly prepared skin area.
Attempts to overcome the drawbacks described above in relation to surgical swab and/or scrub apparatus and techniques involve the development of devices in which the liquid to be applied is contained within the device itself, generally in a hollow handle. Examples of such devices may be found in the following U.S. Pat. Nos. 1,221,227; 2,333,070; 3,324,855; 3,508,547; 3,614,245; 3,774,609; 3,847,151; 3,876,314; 3,891,331; 3,896,808; 3,958,571; 4,148,318; and 4,225,254. The devices disclosed in these patents presented considerable improvements over the relatively primitive method of employing individual cotton balls or sponges with forceps and dipping these into the pan of solution as described above. However, many of the devices disclosed in the aforesaid patents are relatively complex to manufacture, thereby resulting in too high a cost for a device which is disposable after a single use. Moreover, many of the devices disclosed in these prior patents have only one available surface for the applicator sponge or swab. For example, the device disclosed in U.S. Pat. No. 4,225,254 provides a generally conical shaped sponge, thereby making it difficult to assure that the same surface area of the sponge does not contact an already treated area of the patient's skin. Moreover, the conical configuration minimizes the available surface area of the sponge. As noted, available clean, unused surface area of the preparation sponge is one of the most important factors governing the pre-surgical preparation technique.
The device disclosed in U.S. Pat. No. 3,847,151 had considerable promise toward solving most of the problems referred to above. That patent discloses a device wherein a sponge applicator is mounted on a nozzle which extends from a hollow handle containing antiseptic solution. The nozzle includes a joing which can be selectively ruptured prior to use so as to permit the solution to flow from the nozzle into the sponge. In practice, however, this device proved to have functional problems. Mass production techniques being what they are, the stress break at the rupturable joint in the nozzle was not always complete and fluid was not always available. In addition, the rupture was not always properly completed by the user of the device, again resulting in a situation where fluid was not available for use. An additional problem with this device is that the scrub solution (soap) tends to fill the sponge too slowly, whereas the swab solution (antiseptic) tends to fill the sponge too quickly. In general, the product, although well conceived, proved not to be reliable in use.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a simple, inexpensive, and disposable liquid dispensing device which is capable of being used in presurgical procedures for swabbing and scrubbing. It is a further object of the present invention to provide such a device which is devoid of the disadvantages ennumerated above in the devices of the aforementioned patents. It is another object of the present invention to provide such a device useful as a swab or a scrub depending upon the selection of a replacement cartridge of the liquid to be applied. It is a particular object of the present invention to provide a surgical swab or scrub device of the type wherein liquid to be applied is contained within the handle and wherein the liquid can be reliably selectively applied to the applicator sponge.
In accordance with the present invention, an elongated tubular handle has a sponge secured to one end thereof and accepts a cartridge of liquid to be applied through its other end. A rigid spike is secured within the handle proximate its first end and is oriented to rupture the cartridge when the cartridge is fully inserted into the handle. When the cartridge is ruptured a flow path for its contained liquid is provided from within the handle to the sponge. Liquid from the cartridge can be fed to the sponge by gravity-feed or finger pressure radially applied by the user to the cartridge through the tubular handle. In one embodiment, the spike is hollow and conducts the contained liquid to an apertured chamber which projects from the tubular handle to within the sponge. The apertured chamber serves to distribute the liquid evenly during application of the liquid to the patient's body. In another embodiment, the sponge end of the handle has a flexible duck-billed or paddle-shaped terminus which is inserted into the sponge. The spike is a solid generally conical projection into the handle from the paddle. Flow from the ruptured cartridge to the sponge proceeds through plural apertures defined in the handle just rearward of the paddle and forward of the spike. In both embodiments, exertion of radially-applied pressure to the cartridge for the purpose of forcing liquid therefrom is facilitated by the provision of longitudinally extending cut-out portions of the handle. In addition, the inner wall of the handle is provided with an annular shoulder which serves as a stop for the forward end of the cartridge prior to dispensing of the liquid from the cartridge. In order to effect dispensing, the cartridge is fully inserted into the handle, forceing its forward end past the annular stop and into rupturable engagement with the spike. A check valve may be employed within the passageway between the spike and the apertured chamber to prevent back flow of contaminated solution into the sterile cartridge.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be more fully understood, while still further objects and advantages will become apparent, in the following detailed description of embodiments thereof illustrated in the accompanying drawings, wherein:
FIG. 1 is a view in perspective of the liquid dispensing device constructed in accordance with the principles of the present inention;
FIG. 2 is an exploded view in perspective of the device of FIG. 1;
FIG. 3 is a view in longitudinal section of the device of FIG. 1 showing the device in its storage or pre-dispensing condition;
FIG. 4 is a view in section similar to that of FIG. 3 but showing the device in its dispensing mode;
FIG. 5 is a detailed view in section of a portion of the device of FIGS. 1-4, illustrating a check valve employed therein;
FIG. 6 is a view in perspective of another embodiment of the present invention;
FIG. 7 is a view in section of the handle member of the embodiment of FIG. 6; and
FIG. 8 is a side view in partial section of the cartridge member of the embodiment of FIG. 6.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 1-5 of the drawings in greater detail, a dispenser embodiment of the present invention comprises three (3) major parts, namely: a sponge applicator 10; a tubular handle 11; and a cartridge 12. The sponge 10 may be made from a variety of medically accepted sponge-like materials having a wide density range and coarse or fine textures. Coarse texture may be emloyed for scrubbing because it is more abrasive; the finer texture may be utilized for application of antiseptic solution. For general use, sponge 10 is ideally 2 inches square by 1 inch thick; however, these dimensions are provided by way of example only and size is by no means a limiting factor on the present invention. The sponge is preferably configured to have 2 large measure flat application surfaces 13 and 14, but again the configuration is not to be considered limiting on the scope of the present invention. Surfaces 13 and 14 may be generally rectangular, as shown, or may be circular, oval, triangular, etc. Sponge 10 is adapted to receive one end of tubular handle 11 through a suitably provided opening in an end surface 16 of the sponge which resides generally perpendicular to the application surfaces 13 and 14. The end surface 16 of sponge 10 may be suitably die-cut in order to receive the end of handle member 11 in the manner described below. For example, sponge 10 may be cut into a 2"×4"×1/2" piece which is folded in half and glued on portions of the inner surface to cover the received portion of handle 11. Alternatively, sponge 10 may be die-cut into a piece 2"×2" and slotted at surface 13 to permit insertion of the handle member 11. Adhesive may be emloyed to stabilize the sponge onto the handle member.
Cartridge member 12 is a generally tubular member whose outside periphery matches the inside periphery of a portion of tubular handle 11. The outside dimensions of cartridge 12 substantially match the inside dimensions of tubular handle 11 so that the cartridge can freely slide longitudinally within the handle member. The overall size can range from as little as a 5 ml capacity to as large as a 240 ml capacity. In this regard, the entire unit can be selected to be of the appropriate size for the desired amount of liquid to be administered. For a sponge 10 having dimensions of 2"×2"×1", the average capacity of the cartridge would be 30 ml. Cartridge 12 may be produced on a form, fill and seal machine in a continuous operation. Under such circumstances, the container is blow molded, filled with the desired fluid, and sealed in continuous steps of one overall operation. The configuration of the cartridge should not be considered limited and may be fabricated by any plastic-forming equipment, as long as the resulting product has the overall density required to contain the liquid employed. The tubular cartridge should have a plastic density which permits simple placement into the tubular handle while providing sufficient rigidity to permit sliding movement through the handle. The cap 17 for cartridge 12 is disposed at one end thereof and may be formed integrally with the cartridge, if desired. The opposite end 18 of the cartridge may be of the same density as the overall cartridge but in any event, must be suitable to permit rupture and penetration of the cartridge in the manner described herein below.
In this respect, the forward end 18 of the cartridge is preferably thinner than the cap 17 which should be considerably heavier to afford a more rigid plastic form and thereby facilitate application of a pushing force required to displace cartridge 12 with the handle 11 so that forward end 18 can be ruptured.
Handle member 11 comprises, for the most part, a rigid plastic tube having an open end 19 adapted to receive cartridge 12 therein when the cartridge is inserted with its forward end 18 first. The opposite end 21 of handle 11 extends partway into sponge 10 and includes, preferably formed as an integral part thereof, a dispensing chamber 22. The dispensing chamber projects forwardly of handle 11 into sponge 10. A tubular spike 23 extends rearwardly from the dispensing chamber 22 into the tubular portion of handle 11 and is provided with a plurality of radially-extending stabilizing fins 24 which fixedly engage the interior surface of the tubular handle member 11. As noted above, it is preferable that the dispensing chamber 22, spike 23, and stabilizing fins 24 be formed integrally with tubular section 11 by means of an appropriate plastic-forming technique; alternatively, these components may form a part of a separate unit which is secured at the remote ends of stabilizing fins 24 to the interior wall of tubular member 11 by means of a suitable adhesive material or the like. For the latter configuration, an annular lip is formed, as shown, at the forward end 21 of tubular handle member 11 to retain the fins 24 in proper position.
Dispensing chamber 22 may take the form of a shallow cylinder, as shown, or any other suitable configuration. In the preferred shallow cylindrical configuration shown, the opposite circular ends of the chamber are provided with a plurality of apertures 26 which provide fluid communication between the interior of chamber 22 and the surrounding interior of sponge 10. The primary function of dispensing chamber 22 is to provide free flow of pressurized fluid therein into the sponge to soak the sponge for application to the appropriate body surface area. A secondary function of dispensing chamber 22 is to provide sufficient rigidity to the sponge during application of the liquid from the sponge to the patient's body. This latter function is best served when the apertured ends of dispensing chamber 22 have the largest possible surface area. However, smaller dispensing chambers can be utilized with effective results.
Spike 23 is in the form of a tube which projects rearwardly from dispensing chamber 22 and has its interior in flow communication therewith. The end of spike 23 remote from chamber 22 is tapered to a fine point, much like a conventional intravenous spike.
A narrow annular shoulder 27 projects radially inward from the interior wall of tubular handle 11 at an axial location just beyond the tip of spike 23. More specifically, the tip of spike 23 is spaced a slightly shorter distance from end 21 of tubular handle 11 than is the annular lip 27. Lip 27 serves as a flexible stop for end 18 of cartridge 12. Specifically, as illustrated in FIG. 3, the outer edges of the forward end 18 of cartridge 12 abut lip 27 in the stand-by condition of the unit. Lip 27 thereby spaces the forward end 18 of the cartridge from the point of spike 23. When it is desired to apply fluid from the cartridge to a surface area of a patient, or the like, cartridge 12 is pushed forward within tube 11, causing lip 27 to flex and permitting the forward end 18 of cartridge 12 to move forwardly and be ruptured by the point of spike 23. This is best illustrated in FIG. 4. The hollow spike 23 enters the cartridge via cartridge end 18 and permits liquid from the cartridge to flow through the spike to the dispensing chamber 22 where it flows through apertures 26 to soak the sponge 10. A dealing ring, for example, an O-ring 28, projects from the interior surface of handle member 11 radially inward at an axial location between end 21 and stop lip 27. The sealing ring 28 prevents fluid from the sponge from flowing back past sealing member 28 into handle 11.
Tubular handle 11 is provided with a plurality of longitudinally-extending cut-out slots 29. These slots are provided to permit radial compression of the handle 11 so that cartridge 12 may be compressed and liquid forced therefrom into the sponge. It will be appreciated that this compression can be readily achieved by grasping handle 11 in the palm of one's hand and squeezing the hand closed. Alternatively, liquid feed from cartridge 12 to sponge 10 may be effected by gravity flow by simply holding the unit with end 17 upward.
In some applications, it may be desirable to prevent back-flow of dispensed liquid from the sponge and/or dispensing chamber 22 to the cartridge 12. In such cases, a check valve may be supplied within the hollow spike 23 as illustrated in FIG. 5. Sepcifically, a ball member 31 is disposed within the hollow spike 23 and is biased rearwardly toward the sharp spike end by means of a spring 33. The rearwardly biased ball member 31 sits in a valve seat 32 in the non-operating position of the unit to block flow through the hollow spike. If fluid in the cartridge 13 is pressurized, such as by comprssing the handle 11, ball member 31 is unseated from seat 32 by the pressurized liquid which is then permitted to flow into the dispensing chamber 22. When the pressure of the liquid in chamber 22 is greater than the pressure of the liquid in cartridge 12, as would be necessary to result in a reversed flow of the liquid, spring 33 forces ball member 31 to its closed position to preclude reverse flow.
Referring now to FIGS. 6-8 of the accompanying drawings, a second embodiment of the dispenser of the present invention is illustrated. In this embodiment, the primary difference from the embodiment described above relates to the forward or sponge-end of the handle member and the manner in which the sponge is supported and dispensed liquid flows to the sponge. Specifically, a second embodiment includes a sponge applicator 40, a hollow tubular handle 41 and a cartridge 42 which is slidably received by handle 41 through open rearward 43 of the handle. Sponge 40 is similar in function and configuration to sponge 10 of the embodiment illustrated in FIGS. 1-5 and partakes of all of the design features and considerations set forth above for sponge 10. Likewise, cartridge 42 is functionally and structurally similar to cartridge 12 illustrated and described in relation to the embodiment of FIGS. 1-5. In the embodiment of FIGS. 6-8, the forward end 44 of 42 is rounded and readily susecptible to puncture by a spike in the manner described below. The rearward end 45 of cartridge 42 is more rigid to facilitate insertion of cartridge 42 into handle 41 by pushing the rearward end 45 appropriately.
Handle member 41 is similar in function to handle 11 in the embodiments of FIGS. 1-5. As noted above, the rearward end 43 of handle 41 is open to receive the forward end of cartridge 42. The forward end of handle 41 tapers to form a paddle or paddle-shaped projection member 46 which projects forwardly of handle member 41. This paddle-shaped projection 46 is adapted to be received in a suitably provided slot 47 in sponge 40. Projection 46 thus serves to support sponge 40 into which it projects. For this purpose, projection 46 is made somewhat flexible to permit relative flexure between the sponge 40 and handle member 41. A conical spike 48 projects rearwardly of projection 46 into the interior of the forward end of handle 41. Spike 48 serves the purpose of rupturing the forward end 44 of cartridge 42 when that cartridge is sufficiently inserted into handle member 41. To this end, although spike 48 is shown as a sharp, conical projection, it may take other forms, such as a "bullet-nosed" configuration. The important point is that the rearward most part of spike 48 should be sufficiently sharp to permit it to rupture forward end 44 of the cartridge. Spike 48 differs from spike 23 in the embodiment of FIGS. 1-5 in that it does not provide an internal flow path whereby fluid from cartridge 42 can flow out of handle 41; in other words, spike 48 is not hollow. Instead, the forward end of handle 41, rearwardly of projection 46, is provided with a plurality of apertures 49 through which liquid can escape from the interior of handle 41 after it has been squeezed from the ruptured cartridge 42. Apertures 49 are disposed at a longitudinal position of handle 41 which is inserted within slots 47 of sponge 40 so that all of the liquid which escapes from apertures 49 is absorbed into sponge 40.
A narrow annular shoulder 51 projects radially inward from the interior wall of tubular handle 41 at an axial location just rearward of the rearward extremity of spike 48. The similar annular shoulder 52 projects radially inward from the interior wall of handle 41 at a location spaced slightly rearward of shoulder 51. Shoulder 52 serves as a stop for forward end 44 of cartridge 42 when the cartridge is inserted in handle 41. To this end, the axial position of shoulder 52 is such that when it stops further insertion of the cartridge into handle 41, the forward end 44 of the cartridge is spaced from the rearward extremity of spike 48. In the manner similar to that described above in relation to the embodiment of FIGS. 1-5, cartridge 42 can be forced beyond the stop shoulder 52 so that the forward end 44 of the cartridge 42 can be punctured by spike 48. Shoulder 51 serves as a fluid seal, in conjunction with the peripheral wall of the ruptured cartridge 42, to prevent the fluid from the ruptured cartridge from flowing rearwardly in the handle member 41. Handle member 41 may be provided with longitudinally-extending cut-out slots, such as slots 29 in handle member 11, to facilitate radial compression of handle member 41 and thereby force liquid from cartridge 42 through apertures 49 into sponge 40.
In a typical, but by no means limiting configuration of the embodiment of FIGS. 6-8, the various parts have the dimensions noted below. Cartridge 42 is 8 inches long and has a 5/8 inch diameter. Sponge 40 has top and bottom surfaces which are 13/4" square and is 1/8" deep. The overall length of handle member 41 is 6 5/16", the paddle-shaped projection 46 being 1" long. The inner diameter of handle 41 is 5/8" and the thickness of the walls of handle 41 is approximately 0.050". The length of spike 48 is approximately 3/8". The tubular handle 41 may, if desired, have a taper on the order of 0.5° from rearward end 43 toward paddle member 46 in order to facilitate insertion of cartridge 42 and eventual retention of the cartride in the handle. The paddle member or projection 46 is preferably as thin as possible to enhance flexibility and the end of the projection is preferably rounded rather than squared-off. The size of apertures 49 depends upon the desired flow characteristics for the device in view of the liquid being dispensed.
The unit as described, is simple and inexpensive to fabricate and is therefore readily disposable after a single use. Specifically, the unit in the optimal case may be fabricated from only three (3) separate components, namely: sponges 10 and 40; cartridges 12 and 42, which may be fabricated integrally with actuating ends 17 and 45; and tubular handles 11 and 41, which may be fabricated integrally with dispensing chamber 22, spike 23, positioning fins 24 and projection 46 and spike 48. Cartridges, of course, may be interchangeable so that a variety of different liquids may be employed during the same procedure, if an insufficient amount of liquid has been applied. The cartridges are easy to change and remain sealed and sterile until used. The user of the device need not wear a surgical glove in view of the sterility of the cartridge arrangement. The unit may be simply activated by merely grasping the handle in one's hand and gently rapping the end of the cartridge on a hard surface so as to force the forward end 18 of the cartridge against spike 23. Actuation is thus reliable and easily effected and the liquid to be dispensed flows freely to the sponge.
While, we have described and illustrated specific embodiments of our invention, it will be clear that variations of the details of construction which are specifically illustrated and described may be resorted to without departing from the true spirit and scope of the invention as defined in the appended claims.
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An improved liquid dispensing device having particular utility as a surgical scrub and/or swab unit is characterized by a cartridge which is slidable in a rigid handle and rupturably by a spike when slid within the handle to a predetermined degree. Fluid from the ruptured cartridge flows from within the handle to within a sponge through apertures which permit free flow of the dispensed fluid. The handle may be provided with longitudinally-extending slots to facilitate compression of the handle and the cartridge disposed therein. A check valve may be included in the hollow spike passage to prevent back flow of liquid from the sponge and dispensing chamber into the cartridge.
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This invention relates to a pipe insulation produce which, as contrasted to presently available commercial products, eliminates fishmounting of the protective liner from the insulation blanket, eliminates cutting the liner at the job, always a difficult task, is extremely easy to manufacture, ship and handle, and is very easy to use in the field, even under adverse working conditions such as high winds. In addition the invention relates to a method of manufacturing such a product and a method of manufacturing a section of insulated pipe as would hold true, for example, in field operations at a job site.
BACKGROUND OF THE INVENTION
Pipe insulation products currently commercially available provide good insulation for pipes and other thermal equipment once installed, but difficulties are encountered in shipping, handling and using such products in the field. Fishmouthing, which is a condition in which the protective wrap separates from the blanket of insulating material, usually fiberglass, due to normal shipping and handling stresses, is a recurrent problem. Installers have also complained that the protective wrap tends to separate from the insulation blanket in the field, particularly in locations where installation conditions are difficult and/or when high winds are encountered. These difficulties stem from the tendency of the protective wrap to separate from the blanket. And of course there is the frequent problem of having to tape the ends of the protective wrap at the meeting edges of the blanket and its associated protective wrap.
Accordingly it is the object of this invention to overcome the problems described above.
BRIEF DESCRIPTION OF THE INVENTION
The pipe insulation product of this invention consists of a conventional blanket of insulation to which is adhered, at either side of the longitudinally butted ends, a protective liner, with an end of the liner extending peripherally beyond the butted ends to form an overlay. In one form of the invention the overlay comprises a strip of adhesive in the overlap area, which strip is protected by an overlying strip of kraft paper whereby, after installation on a pipe, the kraft paper can be peeled away exposing the adhesive, and the free end of the liner then adhered in overlapping relation to the already adhered liner on the blanket. In an alternative embodiment the exposed end of the protective liner which forms the overlap strip is temporarily adhered at the factory to the already adhered liner so that the insulating product may be shipped and handled up to the moment of field installation without any loose ends which could start fishmouthing or product deterioration. At the moment of field installation the temporary adhesive is broken, a strip of protective kraft paper peeled away, and the liner secured to itself via strip of adhesive which was protected up to that moment by the peeled away kraft paper.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is illustrated more or less diagrammatically in the accompanying drawing wherein:
FIG. 1 is a section view with parts enlarged for clarity of a first embodiment of the invention which includes a protective liner as it would appear in an installed condition;
FIG. 2 is a diagrammatic representation of the first stage of manufacture of the protective liner illustrated in FIG. 1;
FIG. 2A is an expanded view of the liner material indicated at 2A in FIG. 2;
FIG. 2B is an expanded view of the liner material indicated at 2B in FIG. 2;
FIG. 3 is a schematic view of a subsequent portion of the manufacturing process of the embodiment of FIG. 1;
FIG. 4 is a diagrammatic view of a still further processing step in the manufacture of the embodiment of FIG. 1;
FIG. 5 is a view taken substantially along the line 5--5 of FIG. 4;
FIG. 6 is a schematic view illustrating assembly of a protective liner to an insulating blanket;
FIG. 7 is a section view with parts enlarged of the pipe insulation product of FIGS. 1-6 as shown in its condition after completion of manufacture and just prior to use in the field;
FIG. 8 is a diagrammatic representation of a manufacturing process of a second embodiment of the invention;
FIG. 8A is a view to an enlarged scale of the web material indicated at 8A in FIG. 8;
FIG. 8B is a view to an enlarged scale of the web material indicated at 8B in FIG. 8;
FIG. 8C is a cross-sectional view to an enlarged scale of the web material indicated at 8C in FIG. 8;
FIG. 9 is a diagrammatic view of a subsequent step in the manufacturing process of the second embodiment;
FIG. 10 is a view taken substantially along the line 10--10 of FIG. 9;
FIG. 11 is a view of a protective liner following application of the temporary adhesive;
FIG. 12 is a view illustrating securement of the protective liner to an insulating blanket;
FIG. 13 is a cross-section view with parts enlarged for clarity of the pipe insulation product of the second embodiment in its condition immediately following manufacture and up to the moment of installation in the field; and
FIG. 14 is a cross-section of the second embodiment with parts enlarged for clarity illustrating the final assembled product.
Like reference numerals will be used to refer to like parts throughout the following description of the drawing.
DETAILED DESCRIPTION OF THE INVENTION
Referring first to the embodiment of FIGS. 1 through 7, the pipe insulation product in its condition as installed on a pipe is indicated at 10 in FIG. 1. The pipe insulation product consists of an insulation blanket 11 which has an internal diameter capable of being received in snug fitting relationship around the external diameter of a pipe 12 to be insulated. It will be noted that the insulation blanket includes two edges 13, 14 which extend the length of the insulation blanket section and face one another in abutting relationship. A typical longitudinal or axial length of the insulation blanket is three feet. As will be noted from FIGS. 1 and 7 the insulation blanket is cut approximately three-quarters of its radial distance through at a location is directly opposite the longitudinal slit which forms the butted edges 13 and 14, so as to form a hinge which facilitates assembly of the pipe insulation product over pipe 12 during the field manufacture of a field insulated pipe section.
A protective liner, indicated generally at 17, surrounds the insulation blanket 11 and is secured to it at at least two locations. In this instance the protective liner is secured by a longitudinal strip of adhesive 18 located near the edge of the protective liner 17 and near the butt edge 13 of the installation blanket, and a second longitudinal strip of adhesive 19 which is located near butt edge 14. As will be noted, longitudinal strip 19 of adhesive is located peripherally almost 360 degrees from the first strip 18, as viewed in a clockwise direction, and between the end edges of the protective liner 17.
The protective liner includes a metal foil 21 which may be formed of any suitable material, such as aluminum of a suitable thickness. A thickness of 0.005 inches is commonly used in the art.
The outer layer 22 of the protective liner is formed from kraft paper. Laminated between the metal foil 21 and kraft paper 22 is an intermediate layer 23 consisting of a glass scrim and an adhesive.
It will be noted that the protective liner 17 overlaps itself in the region indicated generally at 25. The overlap section 25 is secured by a longitudinal strip of adhesive 26 which adheres the inner surface of the metal foil 21 to the outer surface of kraft paper 22.
The method of manufacturing the pipe insulation product 10 is illustrated best in FIGS. 2 through 6.
In FIG. 2, a facing 28, consisting of kraft paper 22, an intermediate layer consisting of scrim and adhesive 23, and a metal foil 21 are peeled off a facing roll 29. The facing passes between drive roller set 30 to an anvil 31.
At the same time an adhesive strip 33 is unpeeled from an adhesive roll 34 and passed between drive roller set 35 from which it passes to the region of the anvil 31. The adhesive strip 33 consists of a layer of kraft paper 36, two layers of silicone release material 37, 38, and a layer of adhesive 39. It will be noted that the adhesive layer 39 moves toward contact with foil 21 in the region of the anvil.
A cutter roll is indicated at 40, the cutter roll carrying a blade 41 which cuts through the adhered adhesive strip 33 and facing 28 by engagement with the anvil 31.
In FIG. 3 it will be noted that an air header 42 is employed to prevent premature contact of adhesive strip 33 with facing 28. After separation is made via the cutting action of blade 41, a plurality of facing sheets 43 have been formed, each facing sheet consisting of the facing material 28 to which a short section of the adhesive strip 33, indicated at 44, has been adhered. A run off belt 45 delivers the facing strips 43 to a collecting tray 46.
The collected facing strips 43 are then moved to a spray station 48 shown in FIGS. 4 and 5 where chlorinated solvent adhesive is sprayed from nozzles 49, 50 onto the facing strips in two locations to form strips of adhesive 51, 52, the edge of strip 52 being shown in FIG. 5. It will be noted that the chlorinated solvent adhesive is delivered from a header 53 which reciprocates in the direction of the arrow of FIG. 5 along guide rail 54.
The facing strips 43 which now contain adhesive strips 51, 52, are moved from spray station 48 to adhering station 55 of FIG. 6 at which the leading edge of insulation blanket 11 is brought into contact with adhesive strip 52, and the blanket rolled onto facing strip 43 so as to secure the protective liner 17 at two locations, one on each side of the slit which forms abutting edges 13 and 14, to insulation blanket 11.
The final product as it leaves the factory packed in boxes or cartons is illustrated in FIG. 7 with the free end of facing strip 43 carrying adhesive ribbon 44 which is protected by kraft paper 36.
In use, the field installer removes the pipe insulation product 10 in its form as illustrated in FIG. 7 from the box or carton in which it was shipped to the job site, and slips the insulation product over a pipe 12 which passes between the abutting edges 13 and 14 by virtue of the hinge action provided by the slit or cut through 15. Up to this moment in time the adhesive 39 remains protected by kraft paper 36.
After the pipe insulation product has been slipped over pipe 12, the field installer peels away kraft paper 36 and presses the overlap portion 25 of protective liner 17 down onto the outer layer 22 of the already secured portion of the protective liner 17 to the right of the abutting edges 13 and 14 which results in the final manufactured insulated pipe product of FIG. 1.
In the embodiment of FIGS. 8 through 14, a double kraft paper system is disclosed which includes a double kraft paper roll 57 from which a first layer of kraft paper, indicated at 58 with a silicone coating at 59, is peeled and wrapped around waste roll 60, and a second facing layer 61 extends. As best illustrated in FIG. 8B, the second facing layer consists of a layer of kraft paper 62, a silicone coating 63 and an adhesive layer 64.
After blade 41 severs a ribbon 65 from the adhesive strip 61 an alternate facing strip 66 is formed. The alternate facing strip 66 is then transferred to a hot melt adhesive station 67 of FIG. 9 where a hot melt adhesive applicator 68 applies hot melt adhesive to the far left edge of the alternate facing strip 66. The placement of the hot melt adhesive forms, in effect, a temporary closure system, often referred to as a self-seal lap or SSL 69. The self-seal lap 69 is illustrated in side view in FIG. 10.
The final product is shown in expanded cross-section in FIG. 11 where the hot melt adhesive 69 is seen to be resting on, in this instance, a portion of kraft paper 62.
In FIG. 12 the alternate facing strip 66 is shown in the step of being adhered to insulating blanket 11. The final product in its form following completion of the adherring step illustrated in FIG. 12 is shown in FIG. 13 where it will be noted that the hot melt adhesive 69 and kraft paper 62 and silicon coating 63 form part of the product, as manufactured at the factory, which is placed in containers for shipment to the job site.
At the job site the installer merely breaks the temporary seal formed by the hot melt adhesive 69 by a manual lifting operating, installs the insulation blanket 11 onto the pipe 12 and then peels away hot melted adhesive 69 and kraft paper 62 to expose adhesive 64 by which the overlap section 25 is adhered to the already secured portion of the insulation blanket 11.
One further advantage of the embodiment of FIG. 12 is that there is no possibility of undesired separation between the protective liner and the insulation blanket due to rough handling between completion of manufacture at the factory and installation at the job site.
Although a preferred and alternative embodiment of the invention has been illustrated and described, it will be apparent to those skilled in the art that modifications may be made within the spirit and scope of the disclosure herein. Accordingly it is intended that the scope of the invention be limited not by the foregoing exemplary description but solely by the scope of the hereinafter appended claims when interpreted in light of the relevant prior art.
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This invention relates to a pipe insulation product which, as contrasted to presently available commercial products, eliminates fishmouthing of the protective liner from the insulation blanket, eliminates cutting the liner at the job, always a difficult task, is extremely easy to manufacture, ship and handle, and is very easy to use in the field, even under adverse working conditions such as high winds.
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FIELD OF THE INVENTION
The present invention relates generally to a device which secures an object such as a bicycle for transport and repair, and more particularly, to a combination bicycle car rack and work stand especially adapted for attachment to a motor vehicle.
BACKGROUND ART
A bicycle car rack is a common means of transporting bicycles on a vehicle. Typically, such racks utilize the vehicle's existing trailer hitch receiver as an attachment point. When the bicycle rack is not in use, the rack is simply disconnected from the receiver. A well known device to secure a bicycle during repair is a portable repair stand. Typically, the portable repair stand includes a clamp which secures the bicycle at a desired location and orientation, and a base which supports the suspended bicycle.
A number of prior art references disclose both hitch racks and repair stands. One example of a reference which discloses a repair stand which mounts to a motor vehicle includes the U.S. Pat. No. 5,385,280. In this reference, a base member is adapted to connect to the receiver hitch of the vehicle. A riser member adjustably connects to the base member. A clamp support member projects horizontally from the riser member. The clamp support member includes a clamp which may secure the bicycle frame, or other components of the bicycle.
One example of a bicycle rack which is mounted to a vehicle includes the U.S. Pat. No. 4,676,413. This reference discloses a pair of frame mounting brackets secured to the frame of the vehicle. A rack assembly is supported by the frame mounting brackets. Bicycle hangar rods are secured to the top end of the rack assembly. One or more bicycles may be mounted on the rack assembly and secured by the hangar rods.
U.S. Pat. No. 3,981,491 is an example of a portable work stand. The work stand includes a pair of relatively movable jaws between which a tubular member of a bicycle may be securely clamped.
U.S. Pat. No. 5,277,346 discloses a clamping device especially adapted for securing bicycles thereto. The clamping device attaches to the trailer hitch of the vehicle. The clamping device includes cooperating clamping jaws which, once closed, are automatically locked in the closed position about the tubing of the bicycle.
Other examples of bicycle racks adapted for mounting to a vehicle include U.S. Pat. Nos. 5,277,346; 5,803,330; 4,676,414; 5,845,831; and 6,000,593. The purpose common to each of these references is a device which rigidly mounts one or more bicycles to a vehicle; however, no means is provided to orient a bicycle in a multitude of positions in accordance with functional attributes of a work stand. Thus, while the foregoing body of prior art indicates that it is known to support bicycles on vehicles for transporting the bicycles, or to mount a work stand to a vehicle for repair of a single bicycle, it is not contemplated to provide in a single device a combination work stand which enables one to exactly position a bicycle in a desired orientation, and simultaneously provide a bike carrier or bike rack to secure and transport additional bicycles on the same device.
SUMMARY OF THE INVENTION
The present invention, in broad terms, includes capabilities as both a work stand for repair and maintenance of a bicycle, and a bicycle car rack for securing and transporting one or more bicycles to a vehicle. Structurally, the bicycle car rack and work stand of the invention includes a support assembly characterized by an insert tube which is received in the receiver tube of the trailer hitch assembly, a vertical frame tube connected to the protruding end of the insert tube, and a horizontal frame tube connected to the upper end of the vertical frame tube. A clamp assembly is mounted on the horizontal frame tube and may be used to secure and precisely position a bicycle for maintenance or repair. One or more bike carrier members are provided to secure additional bicycles to the car rack and work stand. Optionally, the clamp assembly may be removed and replaced with a bike transport assembly which allows a number of additional bicycles to be secured to the device of this invention. The clamp assembly is adjustable to receive various sizes of bike tubing frames, or other components of a bicycle which must be secure for maintenance or repair.
The vertical frame tube pivotally connects to the receiver tube. A tilt lock pin is provided which allows the vertical frame tube to be secured in a vertical upright position or rotated downward to a more horizontal position. Additional structural support is provided in the form of an anti-sway plate which more rigidly secures the insert tube to the receiver tube of the trailer hitch assembly. A gusset may be provided to further support the vertical frame tube and the gusset, if used, acts as a cable pass-through.
The clamp assembly may be rotated to any desired position. A securing handle is used to engage or disengage a pair of clutch plates, and a user may then rotate the clamp assembly to the desired orientation while the clutch plates are disengaged.
The clamp assembly includes a clamp handle which manipulates an upper jaw of a pair of opposing jaw channels which secure the bicycle component therebetween. A lower jaw channel is fixed to a clamp support tube of the clamp assembly. The upper jaw channel moves with respect to the lower jaw channel, and can be locked into place by pushing down on the clamp handle tube. The gap between the upper and lower jaw channels may be adjustable by a barrel nut which provides linkage between the clamp handle and the clamp support tube. Accordingly, the clamp assembly is able to receive various sized bicycle components.
If there is no need for conducting repair or maintenance on a bicycle, the clamp assembly may be removed and replaced with a bike transport assembly which has a plurality of bike carrier channels. For each of the bike carrier channels, a tubular member of the bicycle rests in the channel, and then a strap may be used to secure the bicycle component to the particular channel.
Although this invention is adapted for attachment to a vehicle, the invention may also be disconnected from a vehicle and mounted to a stationary pedestal receiver.
The foregoing discussed advantages along with others will become apparent from a review of the description which follows in conjunction with the corresponding figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary perspective view of the bicycle car rack and work stand of this invention illustrating the clamp assembly attached, and the bicycle transport assembly detached;
FIG. 2 is a reduced perspective view of the device of this invention illustrating the invention mounted to the trailer hitch assembly of a vehicle, and also illustrating a bicycle secured by the clamp assembly;
FIG. 3 is a fragmentary exploded perspective view of the device of this invention illustrating both the clamp assembly and bike transport assembly detached from the support assembly;
FIG. 4 is a vertical section, taken along line 4 — 4 of FIG. 3, illustrating the device of the invention assembled and with the clamp assembly illustrated in the open position;
FIG. 5 is another vertical section, taken along line 4 — 4 of FIG. 3, illustrating the clamp assembly in the closed position for securing a component of a bicycle;
FIG. 6 is a fragmentary perspective view illustrating the rotational capability of the clamp assembly;
FIG. 7 is a another fragmentary perspective view illustrating the bike transport assembly attached, and further showing a component of a bicycle mounted to one of the bike carrier channels as by a strap assembly;
FIG. 8 is a perspective view of a pedestal assembly which is integral with the device of this invention;
FIG. 9 is a perspective view of a pedestal receiver which may be used when the device is removed from its mounted position on a vehicle;
FIG. 10 is a fragmentary perspective view showing the receiver of FIG. 9 in use; and
FIG. 11 is an exploded perspective view of FIG. 10 .
DETAILED DESCRIPTION
FIG. 1 illustrates the car rack and work stand 10 of this invention. The device includes three major assemblies, namely, a clamp assembly 12 , a support assembly 14 , and a bike transport assembly 110 . As shown in FIG. 2, the support assembly 14 includes a horizontally extending insert tube 16 which is inserted in the receiver tube T of the trailer hitch assembly of a vehicle V. The support assembly 14 further includes a vertical frame tube 18 which rotatably connects to insert tube 16 as by tilt swivel pin 38 . The upper end of frame tube 18 connects to horizontal frame tube 20 as by a welded connection along seam 22 . The insert tube 16 includes one or more mounting pin holes 24 drilled transversely through the tube 16 . Mounting pin P may then secure the insert tube 16 by inserting the pin P through the hole in receiver tube T and the aligned mounting pin hole 24 . FIG. 2 shows but one means by which the device of this invention may be attached to the trailer hitch assembly of a vehicle. The arrangement shown in FIG. 2 is one of the more common trailer hitch assemblies found on many modem vehicles. As well understood by those of skill in the art, insert tube 16 could be modified or adapted for connection to other types of trailer hitch assemblies.
In order to enhance the structural integrity and stability of the device, an anti-sway plate 26 is provided, along with tensioner 28 . As shown in FIG. 2, anti-sway plate 26 overlaps the interface between receiver tube T and insert tube 16 . Tensioner 28 is tightened which then stabilizes the connection between receiver tube T and insert tube 16 . Further structural support is provided by angled gusset plate 30 which is welded to the vertical frame tube 18 . A pair of securing plates 34 which are provided for extra structural support receive both the tilt swivel pin 38 and tilt lock pin 36 . As shown in FIG. 3, the tilt lock pin 36 may be removed which allows vertical frame tube 18 to rotate. Tilt swivel pin 38 remains attached. It may be necessary to rotate vertical frame tube 18 if the device of this invention is mounted to the trailer hitch assembly of a pick-up truck, or other recreational vehicle which has a tailgate. Rotation of frame tube 18 to the more horizontal position would allow the tailgate to be opened.
The horizontal frame tube 20 has mounted thereto one or more bicycle carrier channels 42 . FIG. 1 illustrates just one bike carrier channel 42 ; however, it is well within the scope of this invention to have additional bike carrier channels 42 , depending upon the length of frame tube 20 . Bike carrier channel 42 includes a lower support member 44 , and a rubber or resilient covering 46 overlying the support member 44 . As best seen in FIG. 4, the bike carrier channel is a v-shaped member which is simply welded to the upper surface of frame tube 20 .
Now referring to FIGS. 1, 3 , 4 , 5 and 6 , the clamp assembly 12 will now be explained in more detail. The clamp assembly 12 includes a clamp handle tube 48 which is grasped by the user and is positioned either in the open position as shown in FIG. 3, or in the closed position as shown in FIG. 1 . The clamp handle tube 48 connects to clamp handle square 50 . A pair of clamp side plates 52 and 53 serves as the primary linkage members. As shown, handle pivot pin 54 is inserted between the plates 52 and 53 and thus rotatably connects handle square 50 to plates 52 and 53 . A pair of jaw pivot mounts 66 and 67 attached to the upper surface of clamp support tube 64 . Jaw pivot pin 56 is inserted between pivot mounts 66 and 67 , and thus rotatably attaches side plates 52 and 53 to the mounts 66 and 67 . A clip may be used to secure pins 54 and 56 as necessary, and which allows more easy disassembly of this clamp assembly. Upper jaw channel 60 attaches to the forward or distal ends of side plates 52 and 53 , as best seen in FIG. 4 . Lower jaw channel 62 is mounted to the most forward or distal end of clamp support tube 64 . An upper handle pivot mount 68 is mounted to the lower or under side edge of clamp handle square 50 . A pair of lower handle pivot mounts 72 and 73 as best seen in FIG. 3 are mounted to the clamp support tube 64 proximally of the jaw pivot mounts 66 and 67 . Threaded rod 76 extends from mount 68 and is secured by pivot mount pin 70 . A barrel nut 78 is screwed over the free end of threaded rod 76 . As shown in FIG. 4, the lower end of barrel nut 78 attaches to extension 75 which is rotatably secured between mounts 72 and 73 by pin 74 . The barrel nut can be screwed or unscrewed along the threaded rod 76 to change the effective length of the linkage between upper pivot mount 68 and lower pivot mounts 72 and 73 .
When the clamp handle tube 48 is lifted to the more vertical orientation, jaw 60 is separated from jaw 62 . When the tube 48 is pushed down to the more horizontal orientation, upper jaw of channel 60 moves towards lower jaw channel 62 . As best seen in FIG. 6, a stop tab 80 mounts horizontally between side plates 52 and 53 , and serves as a stop to limit the downward travel of clamp handle tube 48 by contact with the lower edge of upper pivot mount 68 . As best seen in FIG. 5, a portion of the frame F of a bicycle is locked between jaws 60 and 62 . The gap G between jaws 60 and 62 can be changed to accommodate the particular sized frame member which is secured between the jaws by screwing or unscrewing the barrel nut 78 over threaded rod 76 .
As shown in FIG. 6, the clamp assembly 12 may be rotated to any desired position. This capability is achieved by clutch plates 82 and 86 which may be engaged or disengaged by securing handle 100 . More specifically, clutch plate 82 is secured to the proximal end of clamp support tube 64 . Clutch plate 86 is secured to the distal or forward end of horizontal frame tube 20 . A clutch plate bushing 84 is positioned between the clutch plates 82 and 86 . The securing handle 100 includes an elongate threaded bolt 104 which is inserted through an opening on the upper end of vertical frame tube 18 , and extends internally through frame tube 20 . The threaded bolt 104 further extends through an opening 88 in clutch plate 86 , opening 90 in bushing 84 , and through a central opening in clutch plate 82 . A grip 102 attaches to the proximal end of threaded bolt 104 . As shown in FIG. 4, an internal securing nut 106 is rigidly mounted within the interior of support tube 64 , and the distal end of the threaded bolt 104 also extends through the securing nut 106 . If it is desired to rotate the clamp assembly, grip 102 is unscrewed thus loosening clutch plates 82 and 86 . The clamp assembly is rotated to the desired orientation, and then grip 102 is tightened thus forcing clutch plates 82 and 86 back against one another. Washer 103 may be mounted over threaded bolt 104 to help prevent damage against the exterior surface of tube 18 due to contact with the grip 102 .
Hasp openings 92 and 94 may be drilled through clutch plates 86 and 82 , which allows a lock 98 having a hasp 96 to pass therethrough, as shown in FIG. 4 . Thus, the clamp assembly can be locked to prevent theft.
Now referring to FIG. 7, the bike transport system 110 is shown mounted to support assembly 14 . The bike transport assembly includes a plurality of bike carrier channels 112 , mounted to the support tube 114 . As with the clamp assembly, the bike transport assembly 110 also includes its own clutch plate 116 which mounts against clutch plate 86 . Thus, the bike transport assembly 110 may also be rotated to the desired orientation. However, the most common and efficient orientation of the bike transport assembly is when the carrier channels 112 are maintained in a horizontal orientation. The bike carrier channels 112 are constructed in the same manner as carrier channel 42 , and are simply welded to the support tube 114 . In order to lock the bike transport assembly to the support assembly, bike transport assembly also includes a hasp opening 118 which may be aligned with hasp opening 92 to receive the hasp 96 of lock 98 . Although a bike transport assembly 110 has been illustrated, it shall be understood that the device of this invention can also be used in conjunction with other types of securing assemblies such as an assembly for securing skis or other objects. Thus, the ski rack would simply have to include some means for connection to the clutch plate 86 , preferably a clutch plate like clutch plate 116 of the bike transport assembly 110 . Those skilled in the art can envision other specific objects which might be transported by the device of this invention.
A strap assembly 120 as of the type shown in FIG. 7 may be used to secure the bicycles to the bike carrier channels. One particularly effective strap assembly 120 includes a loop 122 , a strap portion 124 , and hook and pile material 126 . The strap assembly 120 can simply be wrapped around the frame F of the particular bicycle, and around the corresponding bike carrier channel. Those skilled in the art can envision other types of strap assemblies which may be used to secure the frame or other components of a bicycle to the bike carrier channels.
FIG. 8 shows an alternative embodiment wherein the device of the invention is not mounted to a vehicle, but rather is permanently mounted to a stationary pedestal. As shown, this stationary embodiment pedestal assembly 130 simply comprises the vertical tube 18 attached to a base 132 . The base 132 is of sufficient weight and size to stabilize the upper components of the device, or the base 132 can be of a smaller size and bolted to the floor for support.
FIGS. 9-11 illustrate yet another alternative embodiment of the invention which allows the invention to be adapted for mounting to another type of stationary base or pedestal. As shown in FIG. 9, this base 134 includes a vertical support member 136 having a lower end attached to base support member 138 . The upper end of vertical support member 136 attaches to horizontal receiving member 140 . Once the device is removed from a vehicle, the free end of insert tube 16 is inserted within the opening 141 of horizontal receiving member 140 . One of the holes in insert tube 16 is aligned with hole 146 and a pin 144 may be used to secure the connection of insert tube 16 and receiving member 140 . A small flange 142 may be welded to horizontal receiving member 140 . This flange 142 helps to assure that anti-sway plate 26 sets flush against securing plate 34 and against the flange 142 .
While various embodiments of the present invention have been described in detail, it is apparent that further modifications and adaptations of the invention will occur to those skilled in the art. However, it is to be expressly understood that such modifications and adaptations are within the spirit and scope of the present invention.
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A combination bicycle car rack and work stand is provided. The device has one or more bicycle carrier channels to secure one or more bicycles, and a clamp assembly which can be oriented in a desired position in order to perform maintenance or repair on another mounted bicycle. The invention may be mounted to a vehicle, or may be mounted to a stationary base. If the clamp assembly is not in use, additional bicycles may be transported by removing the clamp assembly, and attaching a bike transport assembly which includes additional bike carrier channels. Enhanced structural support is provided on the support assembly of the device to ensure a strong and rigid connection with the hitch assembly of a vehicle. The clamp assembly is adapted to receive various sized components of a bicycle, and can be rotatably oriented with ease.
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This invention relates to a method for preparing 2,2,4-trimethyl-1,3-pentanediol di-2-ethylhexanoate which includes controlling the water content of the reaction.
BACKGROUND OF THE INVENTION
The esterification of 2-ethylhexanoic acid with TMPD di-2-ethylhexanoate forms the diester TMPD di-2-ethylhexanoate and water (see FIG. 1 ). An intermediate monoester (TMPD mono-2-ethylhexanoate) is formed during the reaction, which is subsequently converted to the diester (shown in FIG. 2 ). In order to achieve reasonable production rates, the reaction is conducted in the temperature range of 190° C. to 210° C. At 200° C., it takes approximately 24 hours to fully complete the conversion of the reactants to the product. Due to the slow rate of the reaction, it can be said that it is controlled by the thermodynamic rates of the system and not by any mass or heat transfer limitations.
For esterifications of this type, it is customary to accelerate the reaction by adding an excess of one of the reactants. For the reaction described above, 100% excess 2-ethylhexanoic acid is added to the reactor. The reaction can also be accelerated by continuously removing water from the system, thus taking advantage of Le Chatelier's principal to drive the reaction in the forward direction. This is done by sparging nitrogen through the reactor to absorb and remove water from the vessel. A third way of increasing rates is by increasing the temperature of the reaction. It was found that the reaction was accompanied by a degradation mechanism which produced large quantities of the dehydrated monoester (shown in FIG. 3 ). The formation of this dehydrated monoester presents several problems. Firstly, a yield loss problem exists making it necessary to use more reactants to produce a unit of product. Secondly, a separation problem necessitates separation of the dehydrated monoester from the product before it can be sold. Thirdly, it was further found that the rate of formation of the dehydrated monoester is more sensitive to temperature than the main reaction. Thus, one of the key variables to increase the rate of reaction had to be moderated in order to minimize degradation yield loss. The present invention seeks to overcome these problems.
SUMMARY OF THE INVENTION
The present invention is directed to a method for producing 2,2,4-trimethyl-1,3-pentanediol di-2-ethylhexanoate, comprising:
reacting 2,2,4-trimethyl-1,3-pentanediol glycol and 2-ethylhexanoic acid to form 2,2,4-trimethyl-1,3-pentanediol di-2-ethylhexanoate, wherein a water concentration is maintained at about 0.1 weight percent or greater.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an esterification reaction whereby 2 moles of 2-ethylhexanoic acid react with 1 mole of TMPD di-2-ethylhexanoate to form one mole of a diester (TMPD di-2-ethylhexanoate) and 2 moles of water;
FIG. 2 shows the monoester 2,2,4-Trimethyl-1,3-pentanediol-2-ethylhexanoate; and
FIG. 3 shows dehydrated monoester 2,2,4-Trimethylpent-3-enyl-2-ethylhexanoate.
DETAILED DESCRIPTION
The present invention relates to a method for preparing 2,2,4-trimethyl-1,3-pentanediol di-2-ethylhexanoate which includes controlling the water content of the reaction. Moreover, the present invention seeks to overcome the problems associated with the esterification of 2-ethylhexanoic acid with TMPD di-ethylhexanoate, by maintaining the water content concentration in the reactor of between about 0.10 weight percent and about 0.50 weight percent. The detailed embodiments of this invention allow this product to be produced with very good overall yield and excellent carbon efficiency and with a minimum of unwanted byproducts.
In one embodiment, the invention concerns a process wherein 2,2,4-trimethyl-1,3-pentanediol (TMPD) is reacted with excess 2-ethylhexanoic acid with an initial inert gas sparge, such as dry nitrogen to initially drive off the water of reaction. Other mechanisms for removing water, such as stripping water with a low boiling solvent or employing a fractionation column, can be used. The amount of excess 2-ethylhexanoic acid above the theoretical minimum of two equivalents per equivalent of TMPD is within the range about 5 mole percent to about 200 mole percent. The sparge gas flow rate is maintained within about 0 cc/min to about 400 cc/min per liter of reactant volume, from about 10 CC/min to about 200 CC/min per liter, or even from about 25 CC/min to about 100 cc/min per liter. Typically the nitrogen purge is higher during the initial reaction period to remove accumulating water, but is slowed later as water generation tails off and approaches the minimum required to suppress dehydration. At a later stage of reaction the sparge can be discontinued in order to maintain the proper water concentration in the reaction mixture.
The desired reaction temperature is in the range of about 195° C. to about 250° C., about 220° C. to about 245° C., or about 230° C. to about 240° C. As higher reaction temperatures are used the reaction rate and thus productivity can increase. Moreover, as higher temperatures are used, higher pressure and lower nitrogen purge rates may be employed in order to maintain optimal levels of water. Maintenance of a water concentration in the reaction medium in a range of about 0.10 weight percent to about 0.50 weight percent enables minimization of an undesirable dehydration reaction which leads to formation of the unsaturated monoester 2,2,4-triethylpent-3-enyl-2-ethylexanoate. The water concentration can also be maintained in a range of about 0.10 weight percent to about 0.40 weight percent, or in a range of about 0.20 weight percent to about 0.30 weight percent. The reaction is continued until a target concentration of the desired 2,2,4-trimethyl-1,3-pentanediol di-2-ethylhexanoate (TMPD di-2-ethylhexanoate) is produced. Production of the unsaturated monoester is sufficiently low that the intermediate monoester of TMPD can be isolated by distillation and returned to the next cycle of the process. The process can be practiced in either a batch or continuous mode. In the continuous mode, a staged series of reactors is desirable to allow more complete conversion to the diester product. The process can be operated at atmospheric pressure or at reduced pressure.
The process described above can be operated at a pressure of from about 200 Torr to about 760 Torr, from about 300 Torr to about 600 Torr, or even from about 400 Torr to about 500 Torr. Pressure can be increased if water content is close to the maximum described above, in order to suppress further evaporation of the remaining water. Operating at different pressure does not have any inherent advantage from the reaction point of view other than aiding in water removal. According to an embodiment of the present invention, the process can be reacted for from about 5.0 hours to about 17 hours, from about 7.0 hours to about 14 hours, or even from about 9.0 to about 11.0 hours. To reach high conversion levels of the TMPD, such as 90%, 95% or even 98% or higher, the reaction time will vary according to operation temperature, pressure, and purge rate. Typically the reaction is conducted free of additional solvent. However, any low viscosity inert solvent could be added to the system if desired.
EXAMPLES
The present invention can be further illustrated in greater detail by the specific examples presented below. It is to be understood that these examples are illustrative embodiments and are not intended to be limiting of the invention, but rather are to be construed broadly within the scope and content of the appended claims. All parts and percentages in the examples are on a weight percent basis unless otherwise stated. The description in Example 1 gives a typical batch procedure for how 2,2,4-trimethyl-1,3-pentanediol di-2-ethylhexanoate (TMPD di-2-ethylhexanoate) is produced by reaction of TMPD Glycol and 2-ethylhexanoic acid. In Example 1, measures are taken to remove as much water as possible from the system, by both operating under a vacuum of 270 mmHg and by having a high sparge rate of nitrogen (200 cc/min) through the system. In Examples 2 and 3, a similar procedure was followed but the pressure and rate of nitrogen sparge were changed. A summary of the conditions is given in Table 1, along with the range of water concentrations in the reactor during a typical experiment and the amount of dehydrated monoester formed at the end of each experiment.
TABLE 1
Experimental conditions for experiments in Examples 1, 2 and 3.
Nitrogen
Min
Max
Average
Dehydrated
Mono-
Di-
Pressure
Temp.
rate
water
water
water
Time
monoester
ester
ester
Ex.
[mmHg]
[Deg C.]
[cc/min]
[wt %]
[wt %]
[wt %]
[hrs]
[wt %]
[wt %]
[wt %]
1
270
198.34
200
0.05
0.09
0.07
6.65
0.77
25.14
14.51
2
300
199.02
200
0.04
0.09
0.05
7.5
2.01
21.85
21.44
3
760
195.50
50
0.2
0.58
0.42
8.4
0.01
25.41
16.53
The water content in Examples 1 and 2 are almost identical reflecting the similar conditions of both experiments. The concentration of dehydrated monoester at the end of each experiment was 0.77 weight % and 2.01 weight % respectively. In response to the higher pressure and lower nitrogen sparge rate in Example 3, the water content in solution is higher than in either Example 1 or 2. The amount of dehydrated monoester formed in Example 3 is also much lower than in Examples 1 and 2. Small differences in the extent of concentrations of mono- and di-ester can be seen between these experiments that are explained by the temperature profile followed by each experiment, especially during the initial 2 hours of each experiment.
In Table 2, the conditions and some results from Examples 4 to 8 are summarized. All of the experiments were done under atmospheric pressure as it was learned from Example 3 that sufficient water could be removed from the system at this pressure using a nitrogen sparge rate of 50 cc/min. The only exception in Table 2 is Example 4 which had a sparge rate of 200 cc/min. In Examples 7 and 8, the nitrogen sparge was stopped after 2 and 1 hours respectively as it was noticed that the water content was below 0.15 weight %. Except for Example 6 (8.42 hours), all of the examples in Table 2 had a much longer duration than the examples shown in Table 1. Also shown in Table 2 are the concentrations of the monoester and the diester at the end of each experiment.
TABLE 2
Experimental conditions for experiments in Examples 4, 5, 6, 7 and 8
Nitrogen
Min
Max
Average
Dehydrated
Mono-
Di-
Pressure
Temp.
rate
water
water
water
Time
monoester
ester
ester
Ex.
[mmHg]
[Deg C.]
[cc/min]
[wt %]
[wt %]
[wt %]
[hrs]
[wt %]
[wt %]
[wt %]
4
760
199.37
200
0.13
0.40
0.24
18.58
0.25
12.261
25.76
5
760
207.97
50
0.14
0.32
0.21
17.5
0.38
9.641
29.15
6
760
216.96
50
0.00
0.38
0.18
8.42
0.68
14.338
21.24
7
760
225.74
50
0.15
0.76
0.23
17.53
1.36
1.896
32.23
(2 hrs)
8
760
236.23
50
0.01
0.21
0.10
16.91
3.31
0.674
36.57
(1 hrs)
In Example 4, after 18.58 hours, the dehydrated monoester content was 0.25 wt %. The average water concentration in this example was 0.24%. In Example 5, after 17.50 hours, the dehydrated monoester content was 0.38 wt %. The average water concentration in this example was 0.21%. The results from Examples 4 and 5 compare very favorably with the data in Examples 1 and 2 even though the reaction times are much longer and the average temperatures are higher.
Example 7 shows that operating at 225.74° C. for 17.53 hours, with an average water concentration of 0.23%, the dehydrated monoester concentration had reached a concentration of 1.36 weight %. Again, this compares very favorably with data from Example 1 and 2.
In general, the results in Table 2 show that the formation rate of dehydrated monoester is a function of temperature, but it also demonstrates that maintaining water at concentrations above 0.10% can significantly suppress the formation rate of the dehydrated monoester when compared to the data in Table 1.
Example 1
To a 3.8 liter jacketed vessel, 424 grams of 2,2,4-trimethyl-1,3-pentanediol (TMPD Glycol) were charged and heated to a nominal temperature of 150° C. When the TMPD Glycol began to melt, the agitator was switched on to a speed of 400 rpm. In a separate vessel, 1674 grams of 2-ethylhexanoic acid (2-EH) was heated. When the temperature of the 2-EH reached 175° C., it was added to the TMPD Glycol forming a clear solution. The solution was heated until it reached 200° C. The temperature of the vessel contents was controlled by manipulating the temperature of the fluid in the vessel jacket. A sparge of nitrogen was established through a small pipe that discharged 200 cc/min of nitrogen to the base of the vessel under the impeller. The pressure of the vessel was reduced to 270 mmHg to aid water removal from the vessel. A condenser located in the line between the vessel and the vacuum pump condensed any vapors in the gas and was collected in a receiver vessel where it separated into an aqueous and organic layer. The organic layer comprising mainly 2-EH was returned to the vessel while the water layer was removed from the system. During the experiment, samples of the solution were taken at discrete intervals to monitor the progress of the reaction. The results of this experiment are shown in Table 3.
TABLE 3
Experimental results for example 1
Sample
X29262-
X29262-
X29262-
X29262-
X29262-
X29262-
X29262-
X29262-
Number
062-4
062-7
062-10
062-16
062-19
062-22
062-25
062-28
Time [hours]
0
1.15
1.65
2.15
3.15
3.65
4.65
5.65
6.65
Temp.
150
193.73
198.04
199.07
198.98
199.17
199.74
199.36
198.63
[deg C.]
2-Ethylhexanoic
100
87.20
82.52
78.78
71.86
69.58
65.24
61.70
58.95
acid/TMPD
Dehydrated
0
0.03
0.07
0.11
0.26
0.32
0.49
0.62
0.77
monoester
TMPD 2-EH
0
11.26
15.11
17.92
22.17
23.25
24.74
25.30
25.14
monoester
TMPD -2EH
0
1.17
1.91
2.78
5.21
6.30
8.97
11.78
14.51
Diester
Water
0
0.06
0.05
0.09
0.07
0.06
0.06
0.07
0.06
Example 2
To a 3.8 liter jacketed vessel, 424 grams of 2,2,4-trimethyl-1,3-pentanediol (TMPD Glycol) were charged and heated to a nominal temperature of 150° C. When the TMPD Glycol began to melt, the agitator was switched on to a speed of 400 rpm. In a separate vessel, 1674 grams of 2-ethylhexanoic acid (2-EH) was heated. When the temperature of the 2-EH reached 175° C., it was added to the TMPD Glycol forming a clear solution. The solution was heated until it reached 200° C. The temperature of the vessel contents was controlled by manipulating the temperature of the fluid in the vessel jacket. A sparge of nitrogen was established through a small pipe that discharged 200 cc/min of nitrogen to the base of the vessel under the impeller. The pressure of the vessel was reduced to 300 mmHg to aid water removal from the vessel. A condenser located in the line between the vessel and the vacuum pump condensed any vapors in the gas and was collected in a receiver vessel where it separated into an aqueous and water layer. The organic layer comprising mainly 2-EH was returned to the vessel while the water layer was removed from the system. During the experiment, samples of the solution were taken at discrete intervals to monitor the progress of the reaction. The results of this experiment are shown in Table 4.
TABLE 4
Experimental results for example 2
X29262-
X29262-
X29262-
X29262-
X29262-
X29262-
X29262-
X29262-
X29262-
X29262-
Sample Number
064-1
064-4
064-7
064-10
064-13
064-16
064-19
064-22
064-25
064-28
Time [hours]
0
1.50
2.00
2.50
3.00
3.50
4.00
4.50
5.50
7.50
8.50
Temperature
150.00
196.88
199.00
199.09
198.98
199.07
199.37
199.71
199.45
199.27
199.36
[deg C.]
2-Ethylhexanoic
86.84
82.12
77.06
73.04
69.72
66.97
64.52
60.59
55.16
53.74
acid/TMPD
Dehydrated
0.05
0.12
0.29
0.46
0.63
0.81
0.98
1.35
2.01
2.21
monoester
TMPD 2-EH
11.61
15.58
19.10
21.47
23.05
23.94
24.55
24.70
22.93
21.85
monoester
TMPD -2EH Diester
1.11
1.77
3.10
4.58
6.09
7.73
9.39
12.73
19.18
21.44
Water
0.06
0.08
0.04
0.06
0.04
0.04
0.06
0.05
0.05
0.05
Example 3
To a 3.8 liter jacketed vessel, 424 grams of 2,2,4-trimethyl-1,3-pentanediol (TMPD Glycol) were charged and heated to a nominal temperature of 150° C. When the TMPD Glycol began to melt, the agitator was switched on to a speed of 400 rpm. In a separate vessel, 1674 grams of 2-ethylhexanoic acid (2-EH) was heated. When the temperature of the 2-EH reached 175° C., it was added to the TMPD Glycol forming a clear solution. The solution was heated until it reached 200° C. The temperature of the vessel contents was controlled by manipulating the temperature of the fluid in the vessel jacket. A sparge of nitrogen was established through a small pipe that discharged 50 cc/min of nitrogen to the base of the vessel under the impeller. The pressure of the vessel was atmospheric (760 mmHg). A condenser located in the line between the vessel and the vacuum pump condensed any vapors in the gas and was collected in a receiver vessel where it separated into an aqueous and water layer. The organic layer comprising mainly 2-EH was returned to the vessel while the water layer was removed from the system. During the experiment, samples of the solution were taken at discrete intervals to monitor the progress of the reaction. The results of this experiment are shown in Table 5.
TABLE 5
Experimental Results for example 3
X29262-
X29262-
X29262-
X29262-
X29262-
X29262-
Sample Number
068-1
068-3
068-5
068-7
064-9
064-11
Time [hours]
0
0.40
0.90
1.40
1.90
2.40
2.90
Temperature [deg C.]
149.99
169.41
188.03
196.05
198.69
199.11
198.99
2-Ethylhexanoic acid/
97.69
93.31
88.87
84.31
79.76
76.88
TMPD
Dehydrated monoester
0.00
0.00
0.00
0.01
0.02
0.02
TMPD 2-EH monoester
1.98
6.14
10.21
14.08
17.61
19.60
TMPD -2EH Diester
0.04
0.20
0.60
1.26
2.25
3.09
Water
0
0.20
0.40
0.52
0.28
0.42
0.33
X29262-
X29262-
X29262-
X29262-
X29262-
X29262-
Sample Number
064-13
064-15
064-17
064-19
064-21
064-23
Time [hours]
3.40
4.40
5.40
6.40
7.40
8.40
Temperature [deg C.]
199.03
199.67
199.52
198.70
199.13
199.67
2-Ethylhexanoic acid/
73.88
68.56
64.97
62.11
59.41
57.33
TMPD
Dehydrated monoester
0.00
0.05
0.07
0.09
0.11
0.01
TMPD 2-EH monoester
21.48
24.20
25.39
25.72
25.73
25.41
TMPD -2EH Diester
4.18
6.69
9.03
11.51
14.12
16.53
Water
0.48
0.31
0.37
0.79
0.58
0.39
Example 4
To a 3.8 liter jacketed vessel, 424 grams of 2,2,4-trimethyl-1,3-pentanediol (TMPD Glycol) were charged and heated to a nominal temperature of 150° C. When the TMPD Glycol began to melt, the agitator was switched on to a speed of 400 rpm. In a separate vessel, 1674 grams of 2-ethylhexanoic acid (2-EH) was heated. When the temperature of the 2-EH reached 175° C., it was added to the TMPD Glycol forming a clear solution. The solution was heated until it reached 200° C. The temperature of the vessel contents was controlled by manipulating the temperature of the fluid in the vessel jacket. A sparge of nitrogen was established through a small pipe that discharged 200 cc/min of nitrogen to the base of the vessel under the impeller. The pressure of the vessel was atmospheric (760 mmHg). A condenser located in the line between the vessel and the vacuum pump condensed any vapors in the gas and was collected in a receiver vessel where it separated into an aqueous and water layer. The organic layer comprising mainly 2-EH was returned to the vessel while the water layer was removed from the system. During the experiment, samples of the solution were taken at discrete intervals to monitor the progress of the reaction. The results of this experiment are shown in Table 6.
TABLE 6
Experimental Results for example 4
X29262-
X29262-
X29262-
X29262-
X29262-
X29262-
X29262-
X29262-
Sample Number
070-1
070-3
070-5
070-7
070-9
070-11
070-13
070-15
Time [hours]
0
0.08
0.58
1.08
1.58
2.08
2.58
3.08
4.08
Temperature [deg C.]
177.21
177.21
193.68
200.09
201.43
200.82
199.99
199.68
200.66
2-Ethylhexanoic acid
80.00
79.02
78.26
77.00
75.98
74.45
73.47
72.60
70.96
TMPD
20.00
19.20
17.15
14.88
12.86
10.93
9.44
8.21
6.14
Dehydrated monoester
0
0.00
0.01
0.01
0.01
0.02
0.03
0.04
0.05
TMPD 2-EH monoester
0
0.63
3.95
7.21
9.91
12.60
14.36
15.81
17.83
TMPD -2EH Diester
0
0.60
0.12
0.37
0.78
1.40
2.03
2.74
4.31
Water
0
0.14
0.36
0.23
0.25
0.32
0.33
0.24
0.26
X29262-
X29262-
X29262-
X29262-
X29262-
X29262-
X29262-
X29262-
Sample Number
070-17
070-19
070-21
070-23
070-25
070-13
070-15
070-17
Time [hours]
5.08
6.08
7.08
8.08
9.08
3.08
4.08
5.08
Temperature [deg C.]
201.78
201.37
200.45
201.17
201.29
199.68
200.66
201.78
2-Ethylhexanoic acid
69.60
68.17
68.08
66.31
65.81
72.60
70.96
69.60
TMPD
4.55
3.39
2.62
2.06
1.56
8.21
6.14
4.55
Dehydrated monoester
0.07
0.10
0.11
0.12
0.14
0.04
0.05
0.07
TMPD 2-EH monoester
18.95
19.60
19.45
19.43
18.75
15.81
17.83
18.95
TMPD -2EH Diester
6.12
8.05
9.46
11.26
12.88
2.74
4.31
6.12
Water
0.28
0.31
0.29
0.32
0.40
0.24
0.26
0.28
X29262-
X29262-
X29262-
X29262-
X29262-
X29262-
X29262-
Sample Number
070-19
070-21
070-23
070-25
070-41
070-43
070-45
Time [hours]
6.08
7.08
8.08
9.08
16.58
17.58
18.58
Temperature [deg C.]
201.37
200.45
201.17
201.29
200.81
201.50
199.02
2-Ethylhexanoic acid
68.17
68.08
66.31
65.81
61.31
60.98
60.65
TMPD
3.39
2.62
2.06
1.56
0.27
0.24
0.20
Dehydrated monoester
0.10
0.11
0.12
0.14
0.23
0.24
0.25
TMPD 2-EH monoester
19.60
19.45
19.43
18.75
13.46
12.86
12.26
TMPD -2EH Diester
8.05
9.46
11.26
12.88
23.95
24.86
25.76
Water
0.31
0.29
0.32
0.40
0.16
0.13
0.21
Example 5
To a 3.8 liter jacketed vessel, 424 grams of 2,2,4-trimethyl-1,3-pentanediol (TMPD Glycol) were charged and heated to a nominal temperature of 150° C. When the TMPD Glycol began to melt, the agitator was switched on to a speed of 400 rpm. In a separate vessel, 1674 grams of 2-ethylhexanoic acid (2-EH) was heated. When the temperature of the 2-EH reached 175° C., it was added to the TMPD Glycol forming a clear solution. The solution was heated until it reached 210° C. The temperature of the vessel contents was controlled by manipulating the temperature of the fluid in the vessel jacket. A sparge of nitrogen was established through a small pipe that discharged 50 cc/min of nitrogen to the base of the vessel under the impeller. The pressure of the vessel was atmospheric (760 mmHg). A condenser located in the line between the vessel and the vacuum pump condensed any vapors in the gas and was collected in a receiver vessel where it separated into an aqueous and water layer. The organic layer comprising mainly 2-EH was returned to the vessel while the water layer was removed from the system. During the experiment, samples of the solution were taken at discrete intervals to monitor the progress of the reaction. The results of this experiment are shown in Table 7.
TABLE 7
Experimental Results for example 5
X29262-
X29262-
X29262-
X29262-
X29262-
X29262-
X29262-
Sample Number
072-1
072-3
072-5
072-7
072-9
072-11
072-13
Time [hours]
0
0.50
1.00
1.50
2.00
2.50
3.00
3.50
Temperature [deg C.]
175.66
193.03
201.42
204.43
205.99
206.30
206.67
207.30
2-Ethylhexanoic acid
80.00
78.36
76.90
75.73
74.30
73.18
72.11
71.10
TMPD
20.00
18.08
15.29
13.12
10.78
9.21
7.66
6.45
Dehydrated monoester
0
0.01
0.02
0.02
0.03
0.04
0.05
0.07
TMPD 2-EH monoester
0
2.56
6.66
9.70
12.76
14.70
16.39
17.60
TMPD -2EH Diester
0
0.19
0.65
0.79
1.51
2.26
3.18
4.10
Water
0
0.27
0.26
0.25
0.26
0.21
0.22
0.22
X29262-
X29262-
X29262-
X29262-
X29262-
X29262-
X29262-
X29262-
Sample Number
072-15
072-17
072-19
072-21
072-23
072-25
072-27
072-29
Time [hours]
4.50
5.50
6.50
7.50
8.50
9.50
10.00
11.00
Temperature [deg C.]
209.37
210.55
210.31
209.73
210.24
210.00
210.00
210.00
2-Ethylhexanoic acid
69.14
67.86
66.50
65.62
64.58
63.56
62.70
62.18
TMPD
4.34
3.05
2.13
1.46
1.07
0.77
0.56
0.44
Dehydrated monoester
0.10
0.13
0.16
0.20
0.22
0.25
0.27
0.27
TMPD 2-EH monoester
19.23
19.56
18.45
18.71
18.03
17.06
15.85
15.02
TMPD -2EH Diester
6.48
8.66
10.99
13.41
15.34
17.32
19.50
20.90
Water
0.17
0.32
0.19
0.17
0.30
0.18
0.15
0.14
X29262-
X29262-
X29262-
X29262-
X29262-
X29262-
X29262-
Sample Number
072-31
072-33
072-35
072-37
072-39
072-41
072-43
Time [hours]
12.00
13.00
14.00
15.17
16.03
16.83
17.50
Temperature [deg C.]
210.00
210.00
210.00
210.00
210.00
210.00
210.00
2-Ethylhexanoic acid
61.69
61.05
61.00
60.25
59.99
59.71
59.51
TMPD
0.35
0.27
0.22
0.17
0.15
0.13
0.13
Dehydrated monoester
0.30
0.31
0.33
0.35
0.36
0.37
0.38
TMPD 2-EH monoester
14.25
13.23
12.38
11.44
10.73
10.11
9.64
TMPD -2EH Diester
22.29
23.75
24.97
26.71
27.73
28.52
29.15
Water
0.15
0.20
0.22
0.19
0.21
0.35
0.29
Example 6
To a 3.8 liter jacketed vessel, 424 grams of 2,2,4-trimethyl-1,3-pentanediol (TMPD Glycol) were charged and heated to a nominal temperature of 150° C. When the TMPD Glycol began to melt, the agitator was switched on to a speed of 400 rpm. In a separate vessel, 1674 grams of 2-ethylhexanoic acid (2-EH) was heated. When the temperature of the 2-EH reached 175° C., it was added to the TMPD Glycol forming a clear solution. The solution was heated until it reached 220° C. The temperature of the vessel contents was controlled by manipulating the temperature of the fluid in the vessel jacket. A sparge of nitrogen was established through a small pipe that discharged 50 cc/min of nitrogen to the base of the vessel under the impeller. The pressure of the vessel was atmospheric (760 mmHg). A condenser located in the line between the vessel and the vacuum pump condensed any vapors in the gas and was collected in a receiver vessel where it separated into an aqueous and water layer. The organic layer comprising mainly 2-EH was returned to the vessel while the water layer was removed from the system. During the experiment, samples of the solution were taken at discrete intervals to monitor the progress of the reaction. The results of this experiment are shown in Table 8.
TABLE 8
Experimental Results for example 6
X29262-
X29262-
X29262-
X29262-
X29262-
X29262-
Sample Number
082-1
082-3
082-5
082-7
082-9
082-11
Time [hours]
0
0.42
0.92
1.42
1.92
2.42
2.92
Temperature [deg C.]
180.41
195.75
208.19
215.33
218.97
220.48
220.81
2-Ethylhexanoic acid
80
78.83
77.63
75.18
73.35
71.86
70.38
TMPD
20
17.74
15.61
11.66
8.91
6.90
5.20
Dehydrated monoester
0
0.00
0.00
0.03
0.08
0.13
0.20
TMPD 2-EH monoester
0
2.96
6.10
11.57
14.92
17.01
18.49
TMPD -2EH Diester
0
0.09
0.27
1.13
2.29
3.60
5.23
Water
0
0.38
0.25
0.16
0.15
0.16
0.21
X29262-
X29262-
X29262-
X29262-
X29262-
X29262-
Sample Number
082-13
082-15
082-17
082-19
082-21
082-23
Time [hours]
3.42
4.42
5.42
6.42
7.42
8.42
Temperature [deg C.]
220.63
220.19
220.47
221.19
221.44
220.09
2-Ethylhexanoic acid
69.30
67.11
65.57
64.42
63.41
62.76
TMPD
3.99
2.27
1.34
0.86
0.55
0.36
Dehydrated monoester
0.26
0.38
0.48
0.55
0.62
0.68
TMPD 2-EH monoester
19.08
19.31
18.40
17.27
15.83
14.34
TMPD -2EH Diester
6.81
10.35
13.59
16.24
18.91
21.24
Water
0.19
0.13
0.12
0.12
0.11
0.13
Example 7
To a 3.8 liter jacketed vessel, 424 grams of 2,2,4-trimethyl-1,3-pentanediol (TMPD Glycol) were charged and heated to a nominal temperature of 150° C. When the TMPD Glycol began to melt, the agitator was switched on to a speed of 400 rpm. In a separate vessel, 1674 grams of 2-ethylhexanoic acid (2-EH) was heated. When the temperature of the 2-EH reached 175° C., it was added to the TMPD Glycol forming a clear solution. The solution was heated until it reached 230° C. The temperature of the vessel contents was controlled by manipulating the temperature of the fluid in the vessel jacket. A sparge of nitrogen was established through a small pipe that discharged 50 cc/min of nitrogen to the base of the vessel under the impeller. Nitrogen purging was discontinued after 2 hours of operation. The pressure of the vessel was atmospheric (760 mmHg). A condenser located in the line between the vessel and the vacuum pump condensed any vapors in the gas and was collected in a receiver vessel where it separated into an aqueous and water layer. The organic layer comprising mainly 2-EH was returned to the vessel while the water layer was removed from the system. During the experiment, samples of the solution were taken at discrete intervals to monitor the progress of the reaction. The results of this experiment are shown in Table 9.
TABLE 9
Experimental Results for example 7
X29262-
X29262-
X29262-
X29262-
X29262-
X29262-
Sample Number
086-1
086-3
086-5
086-7
086-9
086-11
Time [hours]
0
0.73
1.23
1.73
2.23
2.73
3.23
Temperature [deg C.]
179.84
203.24
214.78
222.42
226.87
228.97
229.58
2-Ethylhexanoic acid
80
76.95
75.88
73.38
71.61
69.63
68.52
TMPD
20
16.17
13.56
9.72
7.05
4.69
3.45
Dehydrated monoester
0
0.00
0.01
0.08
0.18
0.34
0.44
TMPD 2-EH monoester
0
5.45
9.41
14.34
17.03
18.82
19.22
TMPD -2EH Diester
0
0.22
0.66
1.96
3.58
5.95
7.81
Water
0
0.36
0.22
0.18
0.15
0.17
0.19
X29262-
X29262-
X29262-
X29262-
X29262-
X29262-
X29262-
Sample Number
086-13
086-15
086-17
086-19
086-21
086-23
086-25
Time [hours]
3.73
4.73
5.73
6.73
7.73
8.73
10.53
Temperature [deg C.]
229.47
229.26
230.52
232.06
230.96
176.39
228.98
2-Ethylhexanoic acid
67.37
68.17
63.79
63.10
61.97
61.29
64.93
TMPD
2.44
1.27
0.65
0.35
0.20
0.14
0.07
Dehydrated monoester
0.54
0.70
0.92
1.08
1.19
1.26
1.14
TMPD 2-EH monoester
19.13
16.43
16.06
13.88
11.85
10.72
6.95
TMPD -2EH Diester
9.90
12.83
17.99
20.96
24.16
25.94
26.12
Water
0.19
0.76
0.15
0.28
0.15
0.18
0.20
X29262-
X29262-
X29262-
X29262-
X29262-
X29262-
X29262-
Sample Number
086-27
086-29
086-31
086-33
086-35
086-37
086-39
Time [hours]
11.53
12.53
13.53
14.53
15.53
16.53
17.53
Temperature [deg C.]
231.41
230.91
231.23
232.71
234.55
235.73
234.6969
2-Ethylhexanoic acid
65.43
64.91
64.67
64.78
63.64
64.33
63.87
TMPD
0.05
0.03
0.03
0.02
0.02
0.00
0.00
Dehydrated monoester
1.17
1.23
1.26
1.28
1.36
1.33
1.36
TMPD 2-EH monoester
5.71
4.56
3.94
3.24
2.78
2.22
1.90
TMPD -2EH Diester
27.03
28.64
29.49
30.08
31.54
31.46
32.23
Water
0.20
0.20
0.20
0.20
0.20
0.20
0.20
Example 8
To a 3.8 liter jacketed vessel, 424 grams of 2,2,4-trimethyl-1,3-pentanediol (TMPD Glycol) were charged and heated to a nominal temperature of 150° C. When the TMPD Glycol began to melt, the agitator was switched on to a speed of 400 rpm. In a separate vessel, 1674 grams of 2-ethylhexanoic acid (2-EH) was heated. When the temperature of the 2-EH reached 175° C., it was added to the TMPD Glycol forming a clear solution. The solution was heated until it reached 240° C. The temperature of the vessel contents was controlled by manipulating the temperature of the fluid in the vessel jacket. A sparge of nitrogen was established through a small pipe that discharged 50 cc/min of nitrogen to the base of the vessel under the impeller. Nitrogen purging was discontinued after 1 hours of operation. The pressure of the vessel was atmospheric (760 mmHg). A condenser located in the line between the vessel and the vacuum pump condensed any vapors in the gas and was collected in a receiver vessel where it separated into an aqueous and water layer. The organic layer comprising mainly 2-EH was returned to the vessel while the water layer was removed from the system. During the experiment, samples of the solution were taken at discrete intervals to monitor the progress of the reaction. The results of this experiment are shown in Table 10.
TABLE 10
Experimental Results for example 8
X29262-
X29262-
X29262-
X29262-
X29262-
X29262-
Sample Number
088-1
088-3
088-5
088-7
088-9
088-11
Time [hours]
0
0.79
1.29
1.79
2.29
2.79
3.29
Temperature [deg C.]
177.67
209.27
222.07
229.87
234.47
237.05
238.33
2-Ethylhexanoic acid
80
76.63
74.97
72.30
70.19
68.30
66.73
TMPD
20
15.43
11.80
7.90
5.26
3.38
2.00
Dehydrated monoester
0
0.01
0.00
0.25
0.54
0.89
1.27
TMPD 2-EH monoester
0
6.93
11.51
15.98
18.04
18.70
18.05
TMPD -2EH Diester
0
0.00
1.21
3.02
5.46
8.19
11.38
Water
0
0.21
0.11
0.08
0.07
0.07
0.09
X29262-
X29262-
X29262-
X29262-
X29262-
X29262-
X29262-
Sample Number
088-13
088-15
088-17
088-19
088-21
088-23
088-25
Time [hours]
3.79
4.79
5.79
6.79
7.79
8.79
9.79
Temperature [deg C.]
238.80
238.48
238.07
239.19
241.69
239.93
216.73
2-Ethylhexanoic acid
65.82
64.16
62.92
62.81
60.98
62.35
59.31
TMPD
1.29
0.62
0.27
0.13
0.06
0.04
0.03
Dehydrated monoester
1.56
1.99
2.38
2.65
2.99
3.05
3.20
TMPD 2-EH monoester
16.87
14.66
12.83
9.13
7.26
5.48
4.59
TMPD -2EH Diester
13.86
17.92
21.93
24.61
28.03
27.40
32.04
Water
0.13
0.12
0.07
0.10
0.07
0.20
0.03
X29262-
X29262-
X29262-
X29262-
X29262-
X29262-
X29262-
Sample Number
088-27
088-29
088-31
088-33
088-35
088-37
088-39
Time [hours]
10.91
11.91
12.91
13.91
14.91
15.91
16.91
Temperature [deg C.]
236.75
243.87
243.87
243.19
243.68
245.16
244.12
2-Ethylhexanoic acid
59.60
59.53
59.10
64.37
60.11
59.60
58.51
TMPD
0.03
0.01
0.00
0.01
0.02
0.00
0.01
Dehydrated monoester
3.17
3.25
3.34
3.13
3.31
3.27
3.31
TMPD 2-EH monoester
3.99
2.92
2.08
1.34
1.17
0.82
0.67
TMPD -2EH Diester
32.44
33.53
34.61
30.38
34.62
35.42
36.57
Water
0.06
0.05
0.01
0.15
0.19
0.07
0.12
Having described the invention in detail, those skilled in the art will appreciate that modifications may be made to the various aspects of the invention without departing from the scope and spirit of the invention disclosed and described herein. It is, therefore, not intended that the scope of the invention be limited to the specific embodiments illustrated and described but rather it is intended that the scope of the present invention be determined by the appended claims and their equivalents.
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A method for maximizing the yield of 2,2,4-trimethyl-1,3-pentanediol di-2-ethylhexanoate (TMPD di-2-ethylhexanoate) from the reaction of 2,2,4-trimethyl-1,3-pentanediol (TMPD Glycol) and 2-ethylhexanoic acid through the intermediate compound 2,2,4-Trimethyl-1,3-pentanediol-2-ethylhexanoate (TMPD mono-2-ethylhexanoate) is disclosed. The method involves maintaining a water level in the reactor of at least 0.10 weight %, and preferable above 0.20 weight %, thereby reducing formation of 2,2,4-trimethylpent-3-enyl-2-ethylhexanoate, an undesirable by-product.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to mold structures and, particularly, to a mold structure with a fiber-optic sensor used in insert molding.
[0003] 2. Description of related art
[0004] Insert molding is a process in which plastic is injected into a mold that contains an insert. The result of insert molding is a single molded plastic piece with an insert surrounded by the plastic. Inserts can be made of metal or different types of plastic. Insert molding is used in many industries. Applications for insert molding include the production of insert-molded couplings, threaded fasteners, filters, and electrical components. Insert molding expands the capabilities of plastic and can help reduce the cost of products by limiting the amount of costly metals needed to manufacture such products.
[0005] During a typical insert molding process, first a metal insert is put into a mold cavity of a mold. Then, the mold is closed so that molten material can be injected into the mold cavity, via a runner. The molten material in the cavity is cooled to form the molded product. However, if the metal insert is not put into the mold yet the mold is still closed, the mold could rather easily be destroyed. This situation not only affects manufacturing speed but also greatly reduces the work efficiency.
[0006] Therefore, a mold structure that can help prevent injection of molten material when no insert is present is desired in order to overcome the above-described shortcomings.
SUMMARY OF THE INVENTION
[0007] One embodiment of a mold structure includes a mold plate and a fiber-optic sensor mounted therein. The fiber-optic sensor is configured (i.e., structured and arranged) for detecting whether a metal insert is put/placed into the mold plate before the mold structure is closed. If the metal insert is already placed in a desired position, the mold structure is permitted to close, so as to avoid leaving out the metal insert. Therefore, the production and efficiency are greatly increased.
[0008] Other advantages and novel features will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Many aspects of the present mold structure with a fiber-optic sensor can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present mold structure with a fiber-optic sensor. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
[0010] FIG. 1 is an exploded, isometric view of a present mold structure, according to one embodiment;
[0011] FIG. 2 is a schematic view of a fiber-optic sensor of FIG. 1 ;
[0012] FIG. 3 is an assembled view of the mold structure of FIG. 1 ; and
[0013] FIG. 4 is a cross-sectional view of the mold structure of FIG. 3 .
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0014] Referring now to the drawings in detail, FIG. 1 shows a mold structure 100 , in accordance with a present embodiment. The mold structure 1 00 includes a movable mold plate 40 and a fiber-optic sensor 30 . The fiber-optic sensor 30 may be fixed in the movable mold plate 40 . A metal insert 50 is embedded in the mold structure 100 .
[0015] The movable mold plate 40 includes a mold seat 402 , a mold core 404 , and a support element 406 . The mold seat 402 is substantially cube-shaped or at least rectangular parallelepiped in shape and defines a rectangular cavity 4022 in a central area thereof. A stepped hole 4024 is defined in a bottom surface of the cavity 4022 (i.e., extends directly from such bottom surface further into the mold seat 402 ). A sidewall of the mold seat 402 defines a side hole 4026 therein. The side hole 4026 is a through-hole that communicates with the stepped hole 4024 . The mold core 404 is usefully embedded in the mold cavity 4022 of the mold seat 402 and is beneficially fixed to the mold seat 402 by means of bolts. The mold core 404 defines a rectangular groove 4042 in a central area thereof. A bottom surface of the groove 4042 defines a core through hole 4044 . An axis of the core through hole 4044 is aligned with that of the stepped hole 4024 . The support element 406 is substantially rectangular and opportunely is embedded in the groove 4042 . The support element 406 is thereby configured for supporting the metal insert 50 . The support element 406 defines a central hole 4062 therein. An axis of the central hole 4062 is aligned with that of the core through hole 4044 .
[0016] Referring to FIG. 2 , the fiber-optic sensor 30 includes a fiber-optic head 302 , a fixing portion 304 , a sensor light conduit 306 , and a fiber-optic amplifier 308 . One end/face of the fixing portion 304 is connected to the fiber-optic head 302 , and the opposite end/face of the fixing portion 304 is optically connected to a front/first end of the sensor light conduit 306 (i.e., in the form of an output (i.e., light-transmitting) fiber optic and an input (i.e., light-receiving) fiber optic). An opposite end of the sensor light conduit 306 is divided into two branches and is optically connected to the fiber-optic amplifier 308 . The fiber-optic head 302 is cylindrical in shape and includes a light-emitting portion 3022 and a light-receiving portion 3024 . The fixing portion 304 is substantially cylindrical in shape (i.e., disk-shaped). A diameter of the fixing portion 304 is significantly larger than those of the fiber-optic head 302 and the sensor light conduit 306 . In particular, the diameter thereof is similar to that of the stepped hole 4024 of the movable mold plate 40 , to permit a slide-fit therebetween and to thereby ensure that the fixing portion 304 is held in place during the molding procedure. As such, the fixing portion 304 is indeed able to fix the fiber-optic head 302 relative to the movable mold plate 40 .
[0017] The light from the fiber-optic amplifier 308 may be transmitted to the light-emitting portion 3022 of the fiber-optic head 302 through the sensor light conduit 306 . The sensor light conduit 306 is an optic channel (i.e., a fiber optic) configuring for transmitting light. The light-emitting portion 3022 is configured for transmitting/directing light onto the metal insert 50 . Meanwhile, the light-receiving portion 3022 is configured for receiving the reflected light from the metal insert 50 , and the reflected light is transmitted to the fiber-optic amplifier 308 though the sensor light conduit 306 . The fiber-optic amplifier 308 is configured for detecting/measuring the strength of the reflected light so as to judge whether the metal insert 50 has been placed in the mold 1 00 . It is to be understood that the junction between the sensor light conduit 306 and the fiber-optic head 302 at the fixing portion 304 could be either distinct or integral, for the purposes of the present mold sensor system.
[0018] In assembly, referring to FIGS. 3 and 4 , the fiber-optic sensor 30 is inserted into the stepped hole 4024 of the mold seat 402 . The fixing portion 304 slidingly fits into and resists a stepped surface of the stepped hole 4024 . The fiber-optic head 302 extends away from the mold cavity 4022 of the mold seat 402 . At the same time, the sensor light conduit 306 extends in the opposite direction away the fixing portion 304 than does the fiber-optic head 302 . The sensor light conduit 306 extends through the mold seat 402 and ultimately from the side hole 4026 thereof. The portion of the sensor light conduit 306 extending out of the side hole 4026 is connected to the fiber-optic amplifier 308 . The fiber-optic amplifier 308 is connected to a control circuit of a molding machine.
[0019] In the opposite direction from the fixing portion 304 , the fiber-optic head 302 passes through the through hole 4044 of the mold core 404 , and the mold core 404 is fixed in the mold cavity 4022 of the mold seat 402 by means of, e.g., bolts. After that, the central hole 4062 of the support element 406 is placed around the fiber-optic head 302 , and the support element 406 is received in the groove 4042 of the mold core 404 . Finally, the metal insert 50 is fixed on the support element 406 . Note that a top/distal end of the fiber-optic head 302 needs to be lower than a top surface of the support element 50 , so as to avoid contact therebetween and thus avoid damage to that distal end.
[0020] In use, the fiber-optic amplifier 308 produces light. The light is transmitted to the fiber-optic head 302 by the sensor light conduit 306 . Then, the light-emitting portion 3022 projects the light onto the metal insert 50 . The light is reflected by the metal insert 50 to the light-receiving portion 3024 . After that, the light-receiving portion 3024 again transmits light to the fiber-optic amplifier 308 through the sensor light conduit 306 . Owing to the closeness/proximity of the metal insert 50 and the fiber-optic head 302 of the fiber-optic amplifier 30 and, potentially in part, to the generally reflective nature of metals, the light reflected by the metal insert 50 is stronger than any light reflected by an opposed mold portion (not shown). Likewise, if measured prior to moving another opposing mold portion into place, little or no reflection would be detected if the metal insert 50 were not in place. Therefore, the fiber-optic amplifier 308 may detect stronger light signals. If the strength of the light signal is more than a critical value of the output circuit of the fiber-optic amplifier 308 (i.e., indicating that the metal insert 50 is in place), the amplifier may output signals to the control circuit of the mold machine so as to instruct the mold to close. If the metal insert 50 is not put/placed on the support element 406 , the fiber-optic head 302 will not receive enough reflected light and will not drive the mold machine to close.
[0021] A main advantage of the mold structure is that the mold structure may judge whether the metal insert is put into the mold so as to instruct the mold machine to close or not, thus avoiding damage to the mold structure. Accordingly, the production and efficiency are greatly increased. Likewise, a reduction in long-term equipment expenditures (i.e., in terms of maintenance and/or replacement costs) can be expected.
[0022] Understandably, the fiber sensor may be applied in other types of molds, such as pressing molds. The fiber-optic sensor also may be assembled into a fixed mold plate so as to detect the metal insert.
[0023] In still further alternative embodiments, the number of the fiber-optic sensors may be two or more. Further, for example, if three or more fiber-optic sensors are employed, the fiber-optic sensors could be used not only to detect whether the metal insert is put into the mold but also may judge whether the metal insert is inserted flush to the sensor and/or the mold base.
[0024] It is believed that the present embodiments and their advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the examples hereinbefore described merely being preferred or exemplary embodiments of the invention.
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A mold structure ( 100 ) includes a mold plate ( 402 ) and a fiber-optic sensor ( 30 ) mounted therein. The fiber-optic sensor may detect whether a metal insert has been put into the mold plate before the mold structure is closed. If the metal insert is already put in a desired position, the mold structure can be closed so as to avoid leaving out the metal insert. Therefore, the production and efficiency are greatly increased.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional Application No. 60/759,172 filed Jan. 13, 2006 and U.S. Provisional Application No. 60/855,786 filed Nov. 1, 2006, the entire specifications of which are expressly incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The field of the present invention is that of clutch assemblies and friction plates used therein. More particularly the present invention relates to clutch assemblies and friction plates used in automotive transmissions.
BACKGROUND OF THE INVENTION
[0003] In many modern automotive automatic transmissions, particularly of the design known as Lepelltier layout, a single clutch in the transmission will be required to perform its function under widely different conditions, depending on the gear ratio in which the transmission is functioning. There is a need to have good smooth engagement properties in one gear with low torque capacity requirements, and very high holding torque requirements while engaged in another gear.
SUMMARY OF THE INVENTION
[0004] To meet the aforementioned need, the present invention provides a clutch assembly having good smooth engagement properties in one gear with low torque capacity requirements, and very high holding torque requirements while engaged in another gear. The present invention additionally provides friction plates that are highly useful in such clutch assemblies.
[0005] Other features of the invention will become more apparent to those skilled in the art as the invention is further revealed in the accompanying drawings and detailed description of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a partial sectional view of a clutch assembly of the present invention.
[0007] FIG. 2 is an operational view of the clutch assembly of FIG. 1 .
[0008] FIG. 3 is a front elevational view of a preferred embodiment friction plate of the present invention.
[0009] FIG. 4 is a view taken along line 4 - 4 of FIG. 3 .
[0010] FIG. 5 is a front elevational view of an alternate preferred embodiment friction plate of the present invention.
[0011] FIG. 6 is a view taken along line 6 - 6 of FIG. 5 .
[0012] FIGS. 7 and 8 are schematic views illustrating the use of the friction plate shown in FIG. 1 .
[0013] FIG. 9 is a side elevational view of an alternate preferred embodiment friction plate of the present invention.
[0014] FIG. 10 is a front elevational view of an alternate preferred embodiment friction plate of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0015] Referring to FIG. 1 a clutch assembly 7 of the present invention is provided. The clutch has two rotating members provided by a hub 10 and clutch housing 12 . The clutch housing 12 mounts a plurality of axially moveable pressure plates 14 . The pressure plates 14 have a splined connection along their outer diameter with the clutch housing 14 . A snap ring 16 provides a stop for the pressure plates 14 . Juxtaposing the pressure plates 14 are a plurality of friction plates 18 having their inner diameters mounted on a splined portion of the hub 10 . At least one of the friction plates 18 and preferably all of them has a friction facing 20 with multiple coefficients of friction.
[0016] The friction plate 18 has a friction facing 20 with a radially inward first friction facing 22 of a first height 24 and a first coefficient of friction. The friction plate 18 also has a radially outward second friction facing 26 having a second lower height 28 and a second coefficient of friction that is higher than the first coefficient of friction.
[0017] A piston 30 mounted in the clutch housing 12 is provided for actuating the friction pack provided by the pressure plates 14 and friction plates 18 . The piston 30 contacts one of the pressure plates 14 along a radially outward portion of the pressure plates 14 displaced radially outward of a radial centerline 34 of the friction plate friction facing 20 .
[0018] Upon initial actuation of the piston 30 , the radial inner portion of the pressure plates 14 contacts the first friction facings 22 . Separation still exists between the pressure plates 14 and the second friction facings 26 . Accordingly, the clutch 7 exhibits the characteristic of a clutch with smooth shifting qualities due to the first friction facing 22 . Upon further actuation of the piston 30 , the friction pack experiences a contracting axial deflection along its outer radial plane of rotation. The deflection will be a function of contact of the piston 30 with the pressure plates 14 outward of the of the radial centerline 34 of the friction plate facing 20 and a compression of the first friction facing 22 due to the gap with the second friction facings 26 . The aforementioned deflection increases the pressure upon the first friction facing 22 compressing the same. Further pressure by the piston 30 required when the clutch 7 is in a high torque holding operation causes the second friction facing 26 to additionally be engaged by the pressure plates 14 ( FIG. 2 ). The additional frictional engagement with the second friction facings 26 with its increased coefficient of friction greatly enhances the clutch's 7 holding torque.
[0019] Referring to FIG. 9 , an alternate embodiment friction plate 107 is provided having a first facing 110 and a second facing 112 . The first friction facing 110 and the second friction facing 112 have the same height. The second friction facing 112 has a higher coefficient of friction. When the friction plate 107 is used in clutch 7 , the contracting radial deflections of the clutch assembly increases the proportion of the piston load carried by facing 112 relative to facing 110 . The proportionally increased force carried by facing 112 increases the torque carrying capacity of the clutch assembly. This effect can also be enhanced by having the modulus of compression of facing 110 and 112 different with friction facing 110 having a lower modulus of compressibility (less stiff). The aforementioned facing 22 and 26 ( FIGS. 1 and 2 ) can also have a differential modulus of compressibility contributing to the differential loading due to the contracting axial deflection.
[0020] Referring to FIG. 10 , an alternate embodiment friction plate 157 is provided having a first friction facing 158 that encompasses a plurality of button second friction facings 160 . The second friction facing 160 has a greater coefficient of friction and modulus of compressibility than the first friction facing 158 . The second friction facing 160 has a lower height. In operation, the friction plate 157 functions in a manner to those friction plates previously described. The second friction facings 160 tend to run hotter when engaged with a pressure plate an accordingly encircled by an oil groove 164 that intersects the radial edges 166 and 168 of the facing.
[0021] Referring to FIGS. 3 and 4 , a preferred embodiment friction plate 207 useful in the clutch assembly of the present invention and other conventional clutches is shown. The friction plate 207 in the present example is a wet type friction plate. The friction plate 207 has a core plate 210 . The core plate 210 is typically fabricated from carbon steel or plastic. An inner diameter of the core plate 210 has spline teeth 12 to provide a torsional interface with a drive member. In another embodiment (not shown), the core plate 210 may be connected with a torsional damper. In still another embodiment (not shown), the core plate may have spline teeth on an outer diameter.
[0022] Connected along a major continuous circumference of the core plate 210 on at least one side, and as shown both sides, is a first friction facing 214 . The first friction facing 214 is typically a fiber type friction facing such as BW 1777 or BW 4300 or other suitable material. The first facing 214 typically has a static coefficient of friction in the range of 0.12 to 0.14 and a dynamic coefficient of friction in range of 0.14 to 0.16. The first facing 214 can be connected with the core 210 by adhesives or other suitable techniques. The first facing 214 can have a height 218 preferably in the range of 0.4 to 1.0 mm.
[0023] Radially separated outward from a first facing 214 and connected with the core plate 210 along a major continuous circumference is a second facing 222 . The second facing 222 may be similarly fabricated as the material in the first facing 214 , or of an alternate composition and fabrication, but in either case having a different coefficient of friction. In the example shown in FIG. 1 the second facing 222 has a higher static coefficient of friction in the range of 0.16 to 0.22 and a dynamic coefficient of friction in the range of 0.15 to 0.22. The second facing 222 has a height 224 preferably in the range of 0.05 mm to 0.15 less than the height 218 of the first facing 214 .
[0024] Referring to FIGS. 5 and 6 , an alternate preferred embodiment friction plate 237 has a unitary friction disc providing a first facing 238 integrally formed with a second facing 244 . The first facing 238 is radially separated by a groove 240 from the second facing 244 . The core plate 210 can be identical to the core plate previously described for friction plate 237 . The facings 238 and 244 are fabricated from a fiber based friction material and have heights 245 and 247 comparable to those previously described. The fiber based friction material can be a fibrous material with or without various additives to modify its frictional characteristics. The second facing 244 has a higher static and dynamic coefficient of friction due to being saturated with a higher concentration of friction modifying saturant. Examples of such a saturant are phenolic, epoxy, polyimide, or silicone materials, blends thereof, or other suitable materials. Saturation levels vary from 5-60 percent by weight with higher concentrations typically enhancing friction properties. The groove 240 is provided to aid in the prevention of wicking of the saturant from the second facing 244 to the first facing 238 during fabrication. The groove 240 can be formed or milled into the facings before, after, or during connection of the facings with the core plate 210 . The presence of the groove 240 allows the manufacture of friction plates with different frictional properties for different transmissions or different locations within a transmission or clutch pack using the same common materials. The specific frictional characteristics on any given friction plate can be custom selected by simply determining the saturation concentration of the separate friction facings. The saturating operation can be performed before or after connection of the facings with the core plate 210 .
[0025] In operation ( FIGS. 7 and 8 ), the friction plate 207 (friction facing being shown on only one side of the friction plate 207 for illustrative purposes only) is torsionally connected with a first rotating member 262 . A rotating disc 264 is provided which is torsionally connected with a second shaft 68 . The disc 264 and the friction plate 207 can move axially relative to one another to torsionally engage. Upon initial engagement, the disc 264 first contacts the first facing 214 without contacting the second facing 222 . This above noted action allows smooth initial engagement for a gearshift operation. The increased pressure to the disc 264 compresses the first friction facing 214 to a height of the second friction facing 222 and begins to engage the second facing 222 . The disc 264 then engages with both facings 214 and 222 to provide a high holding torque. Differences in the coefficients of friction, surface area, radial widths and radius of the facings 214 , 222 can be specified so that either facings may transmit more torque when both facings 214 , 222 are engaged with the disc 264 . In most applications, the deformation of the first facing 214 should be such that under clutch engagement pressures it compresses to the facing thickness of the second facing 222 . The deformation characteristics of the second facing 222 are such that as additional pressure is applied to the locked up clutch pack, the majority of the additional load is carried on the second facing 222 .
[0026] While preferred embodiments of the present invention have been disclosed, it is to be understood it has been described by way of example only, and various modifications can be made without departing from the spirit and scope of the invention as it is encompassed in the following claims.
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A clutch assembly and clutch plates utilized therein is provided which gives smooth engagement and high holding torque. The friction facing has differing coefficients of friction and different heights. Also claimed is a method of manufacture and a clutch assembly with a piston contacting the friction pack radially displaced from a radial centreline of the friction facings.
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FIELD OF THE INVENTION
[0001] The present invention relates generally to multi-media transmission and, in particular, providing simultaneously transcoding in conjunction with transferring and/or recording of multi-media data.
BACKGROUND OF THE INVENTION
[0002] With the advent of portable video and audio consumer electronic devices, playing various types of multi-media data on these portable video and audio consumer electronic devices has become more popular. Consequently, the demand for multi-media data has significantly increased.
[0003] Currently, for users to obtain multi-media data for their portable video and audio consumer electronic devices, the multi-media data must be in a compatible format for use in their portable video and audio consumer electronic device. If the multi-media data is not in the proper format, then the multi-media data must be transcoded into a format compatible with the users' portable video and audio consumer electronic device. Generally, transcoding multi-media data can be a complicated and time consuming process.
[0004] For example, if a user obtains and saves multi-media data in one format for a particular device, then wishes to transfer the multi-media data to another device, the multi-media data must first be transcoded. For example, if the multi-media data takes two hours to obtain and two hours to transcode the multi-media data into another format, a user has spent four hours obtaining and formatting multi-media data. Therefore, a need exists for a method and system that provides a simultaneous transcode capability in conjunction with transfer and/or record capability.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] The teaching of the present invention can be readily understood by considering the following detailed description in conjunction with the accompanying drawings, in which:
[0006] FIG. 1 illustrates an exemplary architectural overview of the present invention;
[0007] FIG. 2 illustrates a detailed block diagram of an exemplary endpoint device;
[0008] FIG. 3 illustrates an exemplary flow chart of a method for providing simultaneous transcoding of multi-media data;
[0009] FIG. 4 illustrates an exemplary flow chart of a non-storage embodiment of the present invention;
[0010] FIG. 5 illustrates an exemplary flow chart for a storage embodiment of the present invention;
[0011] FIG. 6 illustrates an exemplary flow chart further detailing the simultaneous transcoding of multi-media data; and
[0012] FIG. 7 illustrates a high level block diagram of an exemplary general purpose computer suitable for use in performing the functions described herein.
[0013] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures.
DETAILED DESCRIPTION
[0014] An exemplary architectural overview of a network 100 is illustrated in FIG. 1 . In an exemplary embodiment, network 100 includes a content database 102 and an endpoint device 106 . Although, only a single content database 102 and endpoint device 106 are shown, one skilled in the art will recognize that any number of content databases and endpoint devices may be used. Content database 102 may be, for example, a remote content server or a cable head-end, or a network broadcasting content continuously. As such, in this illustrative embodiment, the content is broadly defined as being provided by a service provider. Content database 102 contains multi-media data that may be transmitted to endpoint device 106 upon request by an end user. Multi-media data may be any type of video, audio, images or combination thereof in any format such as, for example, NTSC or PAL video, MPEG-2 video, H.264 video, MP3 audio, Dolby digital audio, JPEG, GIF and the like.
[0015] Endpoint device 106 may be any consumer electronic device that has storage and/or display capabilities, for example, a set top box with digital video recording (DVR) capabilities, a television with storage capabilities, or a personal computer. In an exemplary embodiment, endpoint device 106 also comprises storage medium 108 , a display 110 and a connection to an external device 112 . Storage medium 108 may be any type of memory such as, for example, an internal hard drive, external hard drive, read access memory (RAM), read only memory (ROM), and flash memory in any format such as secure digital, compact flash or memory stick.
[0016] External device 112 may be any portable media player and is intended to encompass broadly a portable video and audio consumer electronic device, a media-capable cell phone, a portable media capable communicating device (.e.g., a personal digital assistant (PDA) with communication capability or a portable messaging device), a laptop, a remote PC (e.g., via the Internet or via a local area network (LAN)), a portable entertainment system (e.g., located in an automobile), an external writable CD and/or DVD device, an external memory card, or an external storage device and the like. For example, external device 112 may be a Video iPod™ (of Apple Computer of Cupertino, Calif.), a video iPod™ (also of Apple Computer of Cupertino, Calif.), and other similar portable media players.
[0017] In one embodiment, content database 102 and endpoint device 106 communicate with each other via network 104 . Network 104 may be any type of network capable of delivering multi-media data from content database 102 to endpoint device 106 . For example, network 104 may be an internet protocol (IP) based network, such as the Internet typically used for IP TV, or a hybrid fiber coaxial (HFC) network typical used by cable service providers, and the like. It should be noted that the present invention is not limited by the type of network that is used to carry the multi-media data. Furthermore, the present invention is not limited as to the manner of the transmission of the multi-media data to the consumer, e.g., the multi-media data can be on-demand content or it can be broadcast content, e.g., via off-air, cable, satellite, fiber, DSL, or IP delivery.
[0018] Although FIG. 1 illustrates the content as being provided by a service provider in one embodiment, the present invention is not so limited. In an alternative embodiment, the content is provided locally by a local content source 107 without interaction with a service provider. For example, the content may be received from a DVD player or from any storage devices, e.g., from a computer that is in a home and is accessible via a local area network (LAN) within the home. As such, in one example, while the content is being received from a DVD player to be displayed on an output device, e.g., a display, the content can be simultaneously transcoded into an alternate format.
[0019] A detailed view of an exemplary endpoint device 106 is illustrated in FIG. 2 . In an exemplary embodiment of the present invention, endpoint device 106 may be, for example, a set top box with DVR capabilities. FIG. 2 illustrates a block diagram of an exemplary endpoint device 106 that is implemented as a set top box. With reference to FIG. 2 , endpoint device 106 and set top box 106 will be interchangeably used. However, endpoint device 106 should not be interpreted as being limited to a set top box implementation.
[0020] In one embodiment, set top box 106 comprises a controller 208 and a transcoder 210 . Controller 208 comprises, for example, a processor for managing inputs and outputs from the end user and multi-media data transmitted by content database 102 . In an exemplary embodiment, controller 208 may comprise a Back-end System on a Chip (SoC). Controller 208 may also be responsible for the management of the simultaneous transcoding of the multi-media data in conjunction with the transferring and/or recording of the multi-media data.
[0021] In an exemplary embodiment of the present invention, transcoder 210 simultaneously transcodes the multi-media data while controller 208 stores the multi-media data for later retrieval by an end user or outputs the multi-media data for display to the end user. In an exemplary embodiment, transcoding reformats the multi-media data into a format compatible with a connected external device 112 . For example, re-formatting the multi-media data may include changing the resolution, scaling the video, changing the frame rate, changing the compression format (e.g., changing one or more encoding parameters that were used in encoding the multi-media data and the like), or any combination thereof.
[0022] Where the source content received is analog, in an exemplary embodiment of the present invention, transcoder 210 may instead be a smart encoder or dual encoder implementation that simultaneously encodes the received multi-media content into two digital formats, both of which may be stored by controller 208 onto the hard drive 216 . One of these formats is optimized for the end point devices 106 outputs 232 to a display 110 while the other format is optimized for an external device 112 .
[0023] Transcoder 210 may perform the transcoding in multiple ways. In one exemplary embodiment, transcoder 210 may function by processing the multi-media data into uncompressed raw data and then re-formatting the uncompressed raw data into a requested compressed format. For example, if the multi-media data is an MPEG-1 compressed video, the transcoder 210 may process the MPEG compressed video into uncompressed raw video and then re-format the uncompressed video into a requested compressed format such as for example, MPEG-2, MPEG-4, H.264, VC-1 and the like.
[0024] In another exemplary embodiment, transcoder 210 may function by directly transcoding the multi-media data from one format into the requested format. For example, if the multi-media data is an MPEG-2 compressed video, the transcoder 210 may transcode the MPEG-2 compressed video directly into MPEG-4 compressed video by taking advantage of information already contained in the MPEG-2 data. It should be noted that the present invention is not limited by the types of formats of the multi-media data that are being transcoded.
[0025] Moreover, transcoder 210 may simultaneously transcode the multi-media data into a plurality of different formats, e.g., four different formats while controller 208 stores the multi-media data for later retrieval by the end user or outputs the multi-media data for display to the end user. In one embodiment, FIG. 2 illustrates transcoder 210 and controller 208 being connected by one or more high speed connections for simultaneous transcoding in conjunction with transferring and/or recording of multi-media data. FIG. 2 illustrates an alternate high speed connection as well, directly from the front end tuner 202 to the transcoder 210 , which may then route the transcoded data to the controller 208 .
[0026] Connected to controller 208 may be multiple external device interfaces 220 , 224 , 226 , 228 and 230 . For example, external device interfaces may include connection ports such as a 1394 connection port 220 , an Ethernet connection port 224 , a USB 2.0 connection port 226 , an E-SATA connection port 228 or a home network connection port 230 . In an exemplary embodiment, the purpose of the interfaces is to provide set top box 106 with the capability to connect to a number of different types of external devices 112 , regardless of the type of connection. Consequently, one skilled in the art will recognize that set top box 106 may be equipped with other external device interfaces not specifically depicted herein.
[0027] Also connected to controller 208 may be multiple outputs 232 for displaying the multi-media data to the end user. For example, outputs 232 may be audio outputs, component outputs such as Y, Pr and Pb for HD video, composite outputs for SD video, a RF NTSC/BTSC output, a I2S output, a SPDIF output or an HDMI output.
[0028] In addition, in an exemplary embodiment where the set top box 106 has DVR capabilities, controller 208 may be connected to various storage devices such as, for example, a DRAM memory 212 , flash memory 214 and/or a hard drive 216 . Transcoder 210 may also have a storage device connected directly to it, for example, DRAM memory 218 . It should be noted that the present invention is not limited by the type of storage medium that is employed by the set top box.
[0029] The multi-media data from content database 102 is sent to controller 208 through a front end tuner 202 . It should be noted that if the multi-media data can be received in a manner that does not require the use of a tuner (e.g., via an IP pipe), then the front end tuner 202 is an optional module. In an exemplary embodiment, the multi-media data may be sent as radio frequency (RF) input signals. The signals from front end tuner 202 are then transmitted to controller 208 .
[0030] FIG. 3 illustrates an exemplary flow chart of a method 300 for providing simultaneous multi-media data transcoding in conjunction with transferring and/or recording of multi-media data. Method 300 begins at step 302 where multi-media data is received. In an exemplary embodiment, the multi-media data is received from content database 102 , e.g., from a service provider, a broadcaster, a content database on-demand and the like.
[0031] In step 304 , the multi-media data is then transmitted to an output device (e.g., a display or a storage device) of the endpoint device 106 . In an exemplary embodiment of the present invention, the endpoint device 106 may immediately display the requested multi-media data, or it may record the multi-media data, or both. If the end user requests to watch the multi-media data, then the multi-media data is transmitted via output 232 to the display 110 . If the end user requests the multi-media data to be recorded, then the multi-media data is outputted to and stored in one of the storage devices such as for example, DRAM memory 212 , flash memory 214 or hard drive memory 216 .
[0032] In step 306 , as shown in parallel to step 304 , the multi-media data is simultaneously transcoded into at least one alternate format. As discussed above, in an exemplary embodiment, transcoding broadly reformats the multi-media data into an alternate format, e.g., that is compatible with a connected external device 112 . For example, transcoding the multi-media data may include changing the resolution, scaling the video, changing the frame rate, changing the compression format, or any combination thereof. As discussed, external device 112 may be any personal media player such as portable video and audio consumer electronic devices. For example, portable video and audio consumer electronic devices may be a Video iPod™ (of Apple Computer of Cupertino, Calif.), a video iPod™ (also of Apple Computer of Cupertino, Calif.), and other similar portable media players. Alternatively, it may be a media-capable cell phone or handheld communicator or computing device.
[0033] In one embodiment, endpoint device 106 may provide a graphical user interface (GUI) to the user via the display 110 . The applications software for the GUI may be stored locally in DRAM 212 , Flash 214 , or hard disk 216 at the controller 208 and executed by a processor of the controller 208 . Alternatively, the applications software may also be stored remotely and provided to the processor on the controller 208 as a web browser or internet web page. The GUI may provide a pre-populated drop down menu for the end user to select what type of external device 112 is connected to the endpoint device 106 . Based on the end user's selection, the endpoint device 106 may automatically select the proper format the multi-media data should be transcoded into, such that the transcoded multi-media data is compatible for use with the external device 112 .
[0034] In another exemplary embodiment, the endpoint device 106 may be configured such that discovery is performed. In other words, for example, if a USB 2.0 connection is used, the endpoint device 106 may automatically detect the type of multi-media format that is used on external device 112 once external device 112 is connected to the endpoint device 106 . Consequently, upon detection, endpoint device 106 may automatically select the proper format the multi-media data should be transcoded into, such that the transcoded multi-media data is compatible for use with the external device 112 .
[0035] By simultaneously transcoding the multi-media data while either displaying the multi-media data and/or recording the multi-media data, greater efficiency and time savings is achieved for the end user. For example, if a user has to leave in fifteen minutes, but wishes to transfer a movie on his set top box to a personal media player before leaving, the user would previously have to transcode the movie into a format that is compatible with his personal media player. Generally, such transcoding process will take a substantial amount of time, e.g., as much or more time as the actual length of the movie. For example, if the movie runs for two hours, transcoding the movie may take an additional two hours. Therefore, it would be very unlikely for the user to transfer the movie to his personal media player within his time constraints.
[0036] However, using the present invention, the movie will already be transcoded as stored on the set top box (or directly to an external device 112 ). Therefore, the user simply needs to transfer the movie to his personal media player and the movie will already be in a format that is compatible with his media player. The time constraint is limited to a data transfer function and not to a transcoding function. Moreover, the user may be able to transfer the movie to his personal media player to meet his time constraints. Thus, by simultaneously transcoding the movie while displaying the movie to the end user and/or recording the movie as requested by an end user, the end user saves a substantial amount of time. Consequently, greater efficiency and time savings is achieved for the end user, and the probability of the end user being able to practically use multi-media content on their portable devices becomes much higher in practice due to the significantly improved convenience.
[0037] As discussed above, the endpoint device 106 may simultaneously transcode the multi-media data while displaying the multi-media data and/or recording the multi-media data. An exemplary embodiment of a method 400 for simultaneously transcoding the multi-media data while displaying the multi-media data is illustrated in FIG. 4 . This method 400 may also be referred to as the non-storage embodiment of the present invention.
[0038] In an exemplary embodiment, method 400 begins with tuning step 402 . For example, a tuner may tune to a particular frequency of an inputted signal that is carrying the desired multi-media data. The inputted signal is demodulated at step 404 , for example by a demodulator. Subsequently at step 406 , the demodulated signal is then demultiplexed. Then at step 408 , conditional access is determined, e.g., based on pertinent digital rights managements (DRM) rules and/or parameters. Subsequently, the signal is transmitted simultaneously to step 410 to be transcoded and to step 412 to be decoded. As shown in FIG. 4 , an external device may be connected in step 416 , for example via a USB connection. At step 418 , the transcoded signal is transferred to the external device, for example a personal media player (PMP) or cell phone. Simultaneously, the signal is displayed at step 414 to an end user.
[0039] An exemplary embodiment of a method 500 for simultaneously transcoding the multi-media data while recording the multi-media data is illustrated in FIG. 5 . This method 500 may also be referred to as the storage embodiment.
[0040] In an exemplary embodiment, method 500 begins with tuning step 502 . For example, a tuner may tune to a particular frequency of an inputted signal that is carrying the desired multi-media data. The inputted signal is demodulated at step 504 , for example by a demodulator. Subsequently at step 506 , the demodulated signal is then demultiplexed. Then at step 508 , conditional access is determined, e.g., based on pertinent digital rights managements (DRM) rules and/or parameters. Subsequently, the signal is transmitted simultaneously to step 510 to be transcoded and to step 512 to be prepared for recording, for example by a DVR engine microcontroller. At step 512 , the multi-media data may be outputted in step 514 to a storage medium to store the recording, for example via an internal hard drive. Moreover, an external device may be connected in step 520 , for example via a USB connection. At step 522 , the transcoded signal is transferred to the external device, for example a PMP. If an end user requests to replay the recorded multi-media data, the recorded multi-media data may be transmitted to step 516 to be decoded and then to step 518 to be displayed to the end user.
[0041] It should be noted that although FIG. 4 and FIG. 5 both illustrate tuning and demodulating modules, these modules should be deemed as being optional and should not be interpreted to limit the present invention. In other words, depending on the transmission of the multi-media data (e.g., an IPTV solution or Internet downloaded media content), the tuning and demodulating modules should be deemed as optional modules.
[0042] FIG. 6 illustrates a more detailed flow chart of an exemplary method 600 for simultaneously transcoding the multi-media data. Method 600 begins by receiving a multi-media data transport stream, for example an MPEG-2 transport stream in step 602 .
[0043] In step 604 , a decision is made as to whether or not a user is authorized to access the multi-media data transport stream. If the user is authorized, e.g. based upon an authorization table 608 then the method 600 proceeds to step 614 . If the user is unauthorized, then a GUI message is displayed to the user indicating that the user is unauthorized at step 606 .
[0044] Subsequently, the multi-media data transport stream may be stored in step 614 in a storage medium, for example a hard drive.
[0045] A GUI audio/video content list may be presented to a user in step 620 . If a particular audio/video content is selected, the selected audio/video content may be decoded in step 616 and then outputted to a user in step 618 , for example, via a display such as a television.
[0046] Notably, simultaneous to step 614 , a parallel path is executed beginning with a decision whether or not to transcode the multi-media data transport stream in step 622 . An external device list, for example a PMP audio/video list, may be provided in step 624 for a user to select the appropriate external device to be connected to endpoint device 106 via a GUI or the endpoint device 106 may automatically determine the connected external device 112 via a discovery process, as discussed above. If transcoding is not desired at step 622 , the method 600 may loop back to immediately before step 622 to await another response. If transcoding is desired, then method 600 proceeds to step 626 .
[0047] At step 626 , the multi-media data transport stream is decoded or partially decoded depending on the implementation. Although the following steps of method 600 refer to characteristics that are related to video, one skilled in the art will recognize that the following decoding steps may be substituted to adjust to the characteristics of any multi-media data format type.
[0048] The method 600 proceeds to step 628 where a decision is made as to whether the resolution should be changed. A proper display format is provided in step 630 to decision block 628 to help make the decision. The proper display format may be selected based upon the proper detection of the display format of the external device 112 connected to endpoint device 106 , as discussed above with reference to step 624 .
[0049] If a decision is made not to change resolution in step 628 , the method 600 proceeds directly to step 634 . If a decision is made to change the resolution in step 628 , then the method 600 proceeds to step 632 where the multi-media data transport stream is scaled accordingly.
[0050] At step 634 , the multi-media data transport stream is encoded into an alternate format, e.g. compatible with the external device 112 . For example, in step 634 , the multi-media data transport stream may be encoded into an MPEG-4 or AVC format.
[0051] Subsequently at step 638 the transcoded multi-media transport stream may be stored on a storage medium such as, for example, a hard drive. At step 640 , a GUI may be displayed to a user to provide a list of all properly transcoded multi-media data in various formats that are now available, e.g., to be transferred onto an external device 112 .
[0052] Next, at step 642 , a decision is made as to whether a file, such as one of the transcoded multi-media data in the previously provided list of step 640 , should be transferred to an external device 112 . A portable transfer list may be provided at step 644 . If no file is to be transferred at step 642 , method 600 loops back to step 642 to await a decision.
[0053] However, if a file is to be transferred at step 642 , method 600 determines whether or not an external device 112 is connected to the endpoint device 106 at step 646 . If a device is not properly connected, method 600 loops back to immediately before step 646 and waits for an external device 112 to be properly connected.
[0054] When a device is properly connected in step 646 , then method 600 proceeds to step 648 where the file is transferred to a properly connected external device 112 . For example, the file may be transferred via any of the interfaces, as discussed above with reference to FIG. 2 , such as a 1394 connection port 220 , an Ethernet connection port 224 , a USB 2.0 connection port 226 , a E-SATA connection port 228 or a home network connection port 230 . Advantageously, multi-media data is simultaneously transcoded, while being transferred and/or recorded.
[0055] FIG. 7 illustrates a high level block diagram of an exemplary general purpose computer suitable for use in performing the functions described herein. As depicted in FIG. 7 , the system 700 comprises a processor element 702 (e.g., a CPU), a memory 704 , e.g., random access memory (RAM) and/or read only memory (ROM), a transcoder module 705 for providing simultaneous transcoding of multi-media data, and various input/output devices 706 (e.g., storage devices, including but not limited to, a tape drive, a floppy drive, a hard disk drive or a compact disk drive, a receiver, a transmitter, a speaker, a display, a speech synthesizer, an output port, and a user input device (such as a keyboard, a keypad, a mouse, and the like)).
[0056] It should be noted that the present invention can be implemented in software and/or in a combination of software and hardware, e.g., using application specific integrated circuits (ASIC), a general purpose computer or any other hardware equivalents. In one embodiment, the processes provided by the present transcoder module 705 can be loaded into memory 704 and executed by processor 702 to implement the functions as discussed above. As such, the processes provided by the transcoder module 705 (including associated data structures) of the present invention can be stored on a computer readable medium or carrier, e.g., RAM memory, magnetic or optical drive or diskette and the like.
[0057] While the foregoing is directed to illustrative embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.
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A method and system for providing simultaneous transcoding of multi-media data are disclosed. For example, the method receives multi-media data in a first format. In turn, the method transmits the multimedia data to an output device, while simultaneously transcoding the multi-media data into at least one alternate format.
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BACKGROUND OF THE INVENTION
The present invention pertains to improvements in the field of oriented multilayer polymeric films. More particularly, the invention relates to a substrate coated with an oriented multilayer polymeric film having improved flexibility and improved gas barrier properties, as well as to a method of forming such a film on a substrate.
When considering gas barrier properties of an extruded polymeric film coated on a substrate, it is already known in the art that the diffusion coefficient of any penetrating gas such as oxygen, carbon dioxide or water vapor through the polymer film decreases by increasing the crystallinity of the film. This can be achieved by a chemical approach (molecular design) and appropriate cooling rate (chilling in the coating process).
In the case of a substrate coated with an oriented multilayer polymeric film formed from a water-based polymer dispersion and wherein the polymer particles of each layer are oriented in the same direction, it is also known that a three-layer film provides a stronger barrier to gas than a two-layer film having the same weight, which in turn is much more efficient than a one-layer film also having the same weight. Water-based polymer dispersions comprise very small polymer particles having an average size ranging from 150 to 200 mm and containing macro-molecules. When coated on a substrate and properly dried to remove the water, a continuous film is formed.
Whereas scientists are still studying and modeling oriented multilayer polymeric films formed from water-based polymer dispersions, they all agree that these films have a weak flexibility compared to that of extruded polymeric films. This weak flexibility renders waterborne barrier coatings in the packaging industry less attractive. The film flexibility is weak mainly when the film is folded about a fold line parallel to the direction of orientation of the polymer particles in each layer of the multilayer film, causing the film to break at the fold line. This of course impairs the gas barrier properties of the film.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to overcome the above drawbacks and to provide a substrate coated with an oriented multilayer polymeric film which is formed from a polymer dispersion and which has improved flexibility as well as improved gas barrier properties.
It is another object of the invention to provide a method of forming the above film on a substrate.
According to one aspect of the present invention, there is thus provided a substrate coated with an oriented multilayer polymeric film, wherein the film comprises at least two layers of polymer particles oriented along two different directions with respect to one another.
Applicant has found quite unexpectedly that the presence of at least two layers of polymer particles oriented along two different directions with respect to one another in a multilayer polymeric film improves the flexibility of such a film as well as the gas barrier properties thereof.
The present invention also provides, in another aspect thereof, a method of forming the above oriented multilayer polymeric film on a substrate. The method according to the invention comprises the steps of:
a) conveying a substrate along a predetermined path at a predetermined travelling speed and in a predetermined travelling direction;
b) coating the substrate with a polymer dispersion containing polymer particles and a liquid dispersing medium to form on the substrate a first coating of the dispersion;
c) contacting the first coating with a first particle orienting roller driven for rotation about a first longitudinal axis thereof independently of the substrate so as to have a first tangential speed at a surface of the coated substrate, the first particle orienting roller having a first particle orienting pattern arranged at a first angle relative to the travelling direction of the substrate to cause orientation of the polymer particles of the first coating along a first predetermined direction;
d) drying the first coating to cause evaporation of the liquid dispersing medium and formation of a first layer of oriented polymer particles on the substrate; and
e) successively forming on the first layer at least one further layer of oriented polymer particles, each further layer being formed by:
i) coating a previously formed underlying layer of oriented polymer particles with the polymer dispersion to form on the underlying layer a further coating of the dispersion;
ii) contacting the further coating with a further particle orienting roller driven for rotation about a further longitudinal axis thereof independently of the substrate so as to have a further tangential speed at the surface of the coated substrate, the further particle orienting roller having a further particle orienting pattern arranged at a further angle relative to the travelling direction of the substrate to cause orientation of the polymer particles of the further coating along a further predetermined direction; and
iii) drying the further coating to cause evaporation of the liquid dispersing medium and formation of the further layer of oriented polymer particles on the underlying layer;
wherein at least one further angle is different from the first angle or at least one further tangential speed is different from the first tangential speed, thereby forming on the substrate an oriented multilayer polymeric film having at least two layers of polymer particles oriented along two different directions with respect to one another.
The polymer particles are preferably particles of a waterborne polymer. Examples of suitable waterborne polymers which may be used include polyvinylidene chloride, polyvinyl acetate, polyvinyl alcohol and styrene-butadiene copolymers. The liquid dispersing medium can comprise, for example, water, an alcohol or a mixture thereof.
According to a preferred embodiment of the invention, the first particle orienting roller comprises a first cylindrical member rotatable about the aforesaid first longitudinal axis and a first continuous helical land on the first cylindrical member over at least a portion of the length thereof, the first helical land forming a first continuous helical particle orienting groove along the first cylindrical member. The first land and the first groove define the aforesaid first particle orienting pattern. The first helical land may be defined by a single wire helically and tightly wound about a major portion of the length of the first cylindrical member.
According to another preferred embodiment of the invention, two further layers of oriented polymer particles are formed in step (e) by:
i) coating the first layer of oriented polymer particles with the polymer dispersion to form on the first layer a second coating of the dispersion;
ii) contacting the second coating with a second particle orienting roller driven for rotation about a second longitudinal axis thereof independently of the substrate so as to have a second tangential speed at the surface of the coated substrate, the second particle orienting roller having a second particle orienting pattern arranged at a second angle relative to the travelling direction of the substrate to cause orientation of the polymer particles of the second coating along a second predetermined direction;
iii) drying the second coating to cause evaporation of the liquid dispersing medium and formation of a second layer of oriented polymer particles on the first layer;
iv) coating the second layer of oriented polymer particles with the polymer dispersion to form on the second layer a third coating of the dispersion;
v) contacting the third coating with a third particle orienting roller driven for rotation about a third longitudinal axis thereof independently of the substrate so as to have a third tangential speed at the surface of the coated substrate, the third particle orienting roller having a third particle orienting pattern arranged at a third angle relative to the travelling direction of the substrate to cause orientation of the polymer particles of the third coating along a third predetermined direction; and
vi) drying the third coating to cause evaporation of the liquid dispersing medium and formation of a third layer of oriented polymer particles on the second layer.
The second angle is different from the aforementioned first angle or the second tangential speed is different from the aforementioned first tangential speed, whereby the second predetermined direction is different from the aforementioned first predetermined direction. The third angle is different from the second angle or the third tangential speed is different from the second tangential speed, whereby the third predetermined direction is different from the second predetermined direction.
Preferably, the second particle orienting roller comprises a second cylindrical member rotatable about the aforesaid second longitudinal axis and a first plurality of juxtaposed continuous helical lands on the second cylindrical member over at least a portion of the length thereof, the helical lands of the first plurality having a similar pitch and forming a first series of helical particle orienting grooves along the second cylindrical member, the lands of the first plurality and the grooves of the first series defining the second particle orienting pattern. The third particle orienting roller, on the other hand, comprises a third cylindrical member rotatable about the aforesaid third longitudinal axis and a second plurality of juxtaposed continuous helical lands on the third cylindrical member over at least a portion of the length thereof, the helical lands of the second plurality having a similar pitch and forming a second series of helical particle orienting grooves along the third cylindrical member, the lands of the second plurality and the grooves of the second series defining the third particle orienting pattern.
The aforementioned particle orienting roller provided with a series of helical particle orienting grooves is novel and constitutes a further aspect of the invention.
The present invention therefore provides, in a further aspect thereof, a particle orienting roller for orienting polymer particles present in a polymer dispersion coated on a substrate. The particle orienting roller according to the invention comprises a cylindrical member rotatable about a longitudinal axis thereof and a plurality of juxtaposed continuous helical lands on the cylindrical member over at least a portion of the length thereof. The helical lands have a similar pitch and form a series of helical particle orienting grooves along the cylindrical member for imparting a predetermined orientation to the polymer particles when the cylindrical member is rotated while being in contact with the polymer dispersion.
According to a preferred embodiment, the helical lands are defined by a plurality of juxtaposed wires helically wound about the cylindrical member, the helical particle orienting grooves being each defined between adjacent wires.
According to another preferred embodiment, the helical lands are defined by a plurality of helical ribs integrally formed on a peripheral surface of the cylindrical member, the helical particle orienting grooves being each defined between adjacent ribs.
According to a further preferred embodiment, the helical particle orienting grooves are integrally defined in a peripheral surface of the cylindrical member.
A particularly preferred oriented multilayer polymeric film formed on a substrate in accordance with the invention is an oriented three-layer polymeric film having a first layer comprising polymer particles oriented along a first direction, a second layer disposed on the first layer and comprising polymer particles oriented along a second direction angled at about 45° relative to the first direction, and a third layer disposed on the second layer and comprising polymer particles oriented along a third direction parallel to the first direction.
As previously noted, the oriented multilayer polymeric film formed on a substrate in accordance with the present invention has improved flexibility and improved gas barrier properties.
BRIEF DESCRIPTION OF THE DRAWINGS
Further features and advantages of the invention will become more readily apparent from the following description of preferred embodiments as illustrated by way of examples in the accompanying drawings, in which:
FIG. 1 is a schematic view of an apparatus for carrying out a method of forming an oriented two-layer polymeric film on a substrate, according to a preferred embodiment of the invention;
FIG. 2 is a partial schematic bottom plan view of the apparatus shown in FIG. 1, illustrating the orientation of the polymer particles in the successive coatings applied onto the substrate;
FIG. 3 is a schematic view of an apparatus for carrying out a method of forming an oriented three-layer polymer film on a substrate, according to another preferred embodiment of the invention;
FIG. 4 is a partial schematic bottom plan view of the apparatus shown in FIG. 3, illustrating the orientation of the polymer particles in the successive coatings applied onto the substrate;
FIG. 5 is a partial side view of a conventional particle orienting roller which is used in the apparatuses shown in FIGS. 1 and 3;
FIG. 6 is a partial side view of another conventional particle orienting roller which may also be used in the apparatus shown in FIG. 1 or 3 ;
FIG. 7 is a part-sectional side view of a particle orienting roller according to a preferred embodiment of the invention, which is used in the apparatuses shown in FIGS. 1 and 3;
FIG. 8 is a side view of a particle orienting roller according to another preferred embodiment of the invention, which may also be used in the apparatus shown in FIG. 1 or 3 ;
FIG. 9 is a side view of a particle orienting roller according to a further preferred embodiment of the invention, which may also be used in the apparatus shown in FIG. 1 or 3 ;
FIG. 10 is a schematic top plan view illustrating how conventional particle orienting rollers may disposed in the travelling path of the substrate to form thereon an oriented three-layer polymeric film, according to a preferred embodiment of the invention; and
FIG. 11 is a view similar to FIG. 11, illustrating how the travelling direction of the substrate may be varied relative to the rotation axis of one of the conventional particle orienting rollers to form on the substrate an oriented three-layer polymeric film, according to another preferred embodiment of the invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring first to FIGS. 1 and 2, a continuous web 10 of paper is conveyed from a paper roll 12 through a first coating station 14 , a first particle orienting station 16 , a first drying station 18 , a second coating station 20 , a second particle orienting station 22 and a second drying station 24 , by guide rollers 26 and a take-up driving roller 28 . At the coating station 14 , a first coating roller 30 A partially immersed in a first bath 32 A of polymer dispersion containing polymer particles and water is used for coating the paper web 10 with the polymer dispersion so as to form on the paper web 10 a first coating 34 A of polymer dispersion. At the particle orienting station 16 , the first coating 34 A is contacted with a first particle orienting roller 36 which is driven for counterclockwise rotation about its longitudinal axis independently of the paper web 10 so as to have a tangential speed at the surface of the coated paper web 10 . The particle orienting roller 36 is driven by a suitable drive mechanism (not shown). It has a particle orienting pattern 38 arranged at an angle relative to the travelling direction 40 of the paper web 10 to cause orientation of the polymer particles of the first coating 34 A along a first predetermined direction. In the embodiment illustrated, the polymer particles 42 A of the first coating 34 A′ downstream of the roller 36 are oriented in a direction parallel to the travelling direction 40 of the paper web 10 ; in other words, they are oriented at an angle of 0°. The paper web 10 provided with the coating 34 A′ of oriented polymer particles 42 A is then passed through a first dryer 44 A to cause evaporation of the water present in the coating 34 A′ and formation of a first layer 46 A of oriented polymer particles 42 A on the paper web 10 . In FIG. 2, the broken line 48 represents the start of the first drying step.
At the second coating station 20 , a second coating roller 30 B partially immersed in a second bath 32 B of the polymer dispersion is used for coating the first layer 46 A with the polymer dispersion so as to form on the layer 46 A a second coating 34 B of polymer dispersion. At the second particle orienting station 22 , the second coating 34 B is contacted with a second particle orienting roller 50 A which is driven for counterclockwise rotation about its longitudinal axis independently of the paper web 10 so as to have a tangential speed at the surface of the coated paper web 10 . The particle orienting roller 50 A is driven by a suitable drive mechanism (not shown). The tangential speed of the particle orienting roller 50 A is the same as the tangential speed of the particle orienting roller 36 . The roller 50 A has a particle orienting pattern 52 A arranged at angle relative to the travelling direction 40 of the paper web 10 to cause orientation of the of the polymer particles of the second coating 34 B along a second predetermined direction. In the embodiment illustrated, the polymer particles 42 B of the second coating 34 B′ downstream of the roller 50 A are oriented in a direction angled at about 45° relative to the travelling direction 40 of the paper web 10 . The paper web 10 provided with the layer 46 A of oriented polymer particles 42 A, on which is disposed the coating 34 B′ of oriented polymer particle 42 B′ of oriented polymer particles 42 B, is then passed through a second dryer 44 B to cause evaporation of the water present in the coating 34 B′ and formation of a second layer 46 B of oriented polymer particles 42 B on the first layer 46 A of oriented polymer particles 42 A. In FIG. 2, the broken line 54 represents the start of the second drying step.
Thus, the apparatus shown in FIG. 1 enables one to form on the paper web 10 an oriented two-layer polymeric film having a first layer 46 A comprising polymer particles 42 A oriented along a predetermined direction (i.e. 0°), and a second layer 46 B disposed on the first layer 46 A and comprising polymer particles 42 B oriented along a direction angled at about 45° relative to the direction of orientation of the polymer particles 42 A.
The apparatus illustrated in FIG. 3 is similar to the one illustrated in FIG. 1, with the exception that a third coating station 56 , a third particle orienting station 58 and a third drying station 60 have been added in order to form on the second layer 46 B of oriented polymer particles 42 B a third layer of oriented polymer particles, As shown in FIGS. 3 and 4, at the coating station 56 , a third coating roller 30 C partially immersed in a third bath 32 C of the polymer dispersion is used for coating the second layer 46 B with the polymer dispersion so as to form on the layer 46 B a third coating 34 C of polymer dispersion. At the particle orienting station 58 , the third coating 34 C is contacted with a third particle orienting roller 50 B which is driven for clockwise rotation about its longitudinal axis independently of the paper web 10 so as to have a tangential speed at the surface of the coated paper web 10 . The particle orienting roller 50 B is driven by a suitable drive mechanism (not shown). It has a particle orienting pattern 52 B which is the same as the particle orienting pattern 52 A of the particle orienting roller 50 A. Since the roller 50 B has a negative tangential speed as opposed to the positive tangential speed of the roller 50 A, the particle orienting pattern 52 B of the roller 50 B imparts to the polymer particles of the third coating 34 C an orientation along a direction which is the mirror image of the direction of orientation of the polymer particles 42 B of the second layer 46 B Thus, in the embodiment illustrated, the polymer particles 42 C of the third coating 34 C′ downstream of the roller 50 B are oriented in a direction angled at about 45° relative to the travelling direction 40 of the paper web 10 , but at 90° relative to the direction of orientation of the polymer particles 42 B of the second layer 46 B. The paper web 10 provided with the layer 46 A of oriented polymer particles 42 A and the layer 46 B of oriented polymer particles 42 B, on which is disposed the coating 34 C′ of oriented polymer particles 42 C, is then passed through a third dryer 44 C to cause evaporation of the water present in the coating 34 C′ and formation of a third layer 46 C of oriented polymer particles 42 C on the second layer 46 B of oriented polymer particles 42 B. In FIG. 4, the broken line 62 represents the start of the third drying step.
It is of course possible to replace the particle orienting roller 50 B by the particle orienting roller 36 driven for counterclockwise rotation about its longitudinal axis. In this case, the direction of orientation of the polymer particles 42 C of the third layer 46 C would be the same as the direction of orientation of the polymer particles 42 A of the first layer 46 A. In other words, the polymer particles 42 C of the third layer 46 C would be oriented in a direction parallel to the travelling direction 40 of the paper web 10 (i.e. at 0°).
The particle orienting roller 36 used in the apparatuses shown in FIGS. 1 and 3 is a conventional particle orienting roller which is illustrated in more detail in FIG. 5 . As shown in FIG. 5, the roller 36 comprises a cylindrical member 64 and a single wire 66 helically and tightly wound about the cylindrical member 64 over a major portion of the length thereof. The single wire 66 forms a continuous helical groove 68 adapted to impart to the polymer particles an orientation in a direction at 90° relative to the longitudinal axis of the cylindrical member 64 . The single wire 66 defines a continuous helical land or ridge on the circumference of the cylindrical member 64 . Thus, the pitch of the particle orienting roller 36 is equal to a lead thereof, the lead being the distance a helical land or ridge advances axially in one turn of the particle orienting roller 36 . The land defined by the single wire 66 together with the groove 68 define the aforesaid particle orienting pattern 38 .
Instead of using the particle orienting roller 36 , it is possible to use the roller 36 ′ illustrated in FIG. 6 . As shown, the particle orienting roller 36 ′ comprises a cylindrical member 70 provided with a single helical groove 72 which is integrally defined in the peripheral surface of the cylindrical member 70 and extends along a major portion of the length thereof. The helical groove 72 is adapted to impart to the polymer particles an orientation in a direction at 90° relative to the longitudinal axis of the cylindrical member 70 . In this single helical groove 72 , the lead is equal to the pitch of the particle orienting roller 36 ′. A single continuous helical land 73 is formed.
Each of the particle orienting rollers 50 A and 50 B is a particle orienting roller 50 according to a preferred embodiment of the invention, which is illustrated in FIG. 7 . As shown, the roller 50 comprises a cylindrical member 74 and a plurality of juxtaposed continuous helical lands defined by a plurality of juxtaposed wires 76 helically wound about the cylindrical member 74 over a major portion of the length thereof. The wires 76 are wound so as to have the same pitch. A helical particle orienting groove 78 is defined between each pair of adjacent wires 76 . The lands defined by the wires 76 together with the grooves 78 define the aforesaid particle orienting pattern 52 A, 52 B. As opposed to the particle orienting rollers 36 and 36 ′ shown in FIGS. 5 and 6, respectively, the lead l of the particle orienting roller 50 is not equal to the pitch thereof, but rather to “n” times the pitch thereof, “n” being the number of wires 76 helically wound about the cylindrical member 74 . This enables the particle orienting grooves 78 to orient the polymer particles along a direction which is angled at about 5° to about 85° relative to the travelling direction 40 of the paper web 10 , depending on the pitch and the tangential speed of the roller 50 .
The pitch of the particle orienting roller 50 has a direct influence on the angle of the particle orienting pattern thereof. Therefore, by changing the pitch of the roller 50 , it becomes possible to change the direction of orientation of the polymer particles. Alternatively, this can be done by changing the relative orientation of the roller 50 with respect to the travelling direction 40 of the web 10 . Further directional changes can be imparted to the polymer particles by varying the tangential speed of the particle orienting roller 50 . The tangential speed can be varied by changing the angular speed of the roller or its diameter. The tangential speed can also be varied by changing the direction of rotation of the roller 50 . As previously noted, a change in the direction of rotation of the roller 50 from a counterclockwise to a clockwise rotation may be seen as a change from a positive to a negative tangential speed.
Instead of using the particle orienting roller 50 , it is also possible to use the rollers 50 ′ and 50 ″ illustrated in FIGS. 8 and 9, respectively. As shown in FIG. 8, the particle orienting roller 50 ′ comprises a cylindrical member 80 and a plurality of juxtaposed continuous helical lands defined by a plurality of helical ribs 82 integrally formed on the peripheral surface of the cylindrical member 80 over a major portion of the length thereof. A helical particle orienting groove 84 is defined between each pair of adjacent ribs 82 . The helical grooves 84 are adapted to orient the polymer particles along a direction which is angled at about 5° to about 85° relative to the travelling direction 40 of the paper web 10 , depending on the pitch and the tangential speed of the roller 50 ′. The particle orienting roller 50 ″ illustrated in FIG. 9 comprises a cylindrical member 86 provided with a plurality of helical particle orienting grooves 88 which are integrally defined in the peripheral surface of the cylindrical member 86 and extend along a major portion of the length thereof. The helical grooves 88 are also adapted to orient the polymer particles along a direction which is angled at about 5° to about 85° relative to the travelling direction 40 of the paper web 10 , depending on the pitch and the tangential speed of the roller 50 ″. A plurality of juxtaposed continuous helical lands 89 are formed. In the embodiments illustrated in FIGS. 8 and 9, the particle orienting grooves 84 and 88 are similar to the particle orienting grooves 78 of the roller 50 shown in FIG. 7 . The lead l′ of the roller 50 ′ and the lead l″ of the roller 50 ″ are also the same as the lead l of the roller 50 .
In the embodiments illustrated in FIGS. 1-4, the rotation axes of the rollers 36 , 50 A and 50 B are all at right angle relative to the travelling direction 40 of the paper web 10 . It is possible to achieve the same results without using the particle orienting rollers 50 A and 50 B, by replacing these rollers with the particle orienting rollers 36 and inclining one of the rollers 36 relative to the travelling direction 40 of the paper web 10 . This is schematically illustrated in FIG. 10 . As shown, three particle orienting rollers 36 A, 36 B and 36 C are used, the rollers 36 A and 36 C being disposed so that their rotation axis extends at right angle relative to the travelling direction 40 of the paper web 10 . The roller 36 B, however, is disposed so that its rotation axis extends at a tilt angle of about 45° relative to the travelling direction 40 of the paper web 10 . As a result of such an inclination, the particle orienting groove 68 (shown in FIG. 5) of the roller 36 B imparts to the polymer particles an orientation which is angled at about 45° relative to the travelling direction 40 of the paper web 10 . Thus, the oriented three-layer film formed as a result of the disposition of the rollers 36 A, 36 B and 36 C comprises a first layer of polymer particles oriented along a direction parallel to the travelling direction 40 of the paper web, a second layer of polymer particles oriented along a direction angled at about 45° relative to the direction 40 , and a third layer of polymer particles oriented along a direction parallel to the direction 40 . Although the particle orienting roller 36 B is shown in FIG. 10 as being inclined at about 45° relative to the travelling direction 40 of the paper web 10 , it is possible to dispose the roller 36 B so that its rotation axis extends at a tilt angle ranging from about 5° to about 85° relative to the direction 40 .
The same result as that obtained with the embodiment shown in FIG. 10 can also be achieved by disposing the particle orienting roller 36 B so that its rotation axis is parallel to the rotation axis of the particle orienting roller 36 A and by varying the travelling direction of the paper web 10 , prior to the second coating of polymer dispersion being contacted by the roller 36 B, so that it is angled at the aforesaid tilt angle relative to the rotation axis of the roller 36 B. This is schematically illustrated in FIG. 11 . As shown, by using appropriate guide rollers 90 , one may vary the travelling direction of the paper web 10 upstream of the roller 36 B so that the travelling direction 40 ′ is angled at about 45° relative to the rotation axis of the roller 36 B.
The following non-limiting example further illustrates the invention.
EXAMPLE
An oriented three-layer polymeric film A was formed on a paperboard, by the method described above. The film A comprised a first layer of polymer particles oriented along a direction parallel to the travelling direction of the paperboard (i.e. 0°), a second layer of polymer particles oriented along a direction angled at 45° relative to the travelling direction of the paperboard (i.e. 45°), and a third layer of polymer particles oriented along a direction parallel to the travelling direction of the paperboard (i.e. 0°). The moisture vapor transmission rate (MVTR) of such a film was measured at 37.8° C. and 100% relative humidity and compared with the MVTR of an oriented three-layer polymeric film B formed on the same type of paperboard by replacing the particle orienting rollers 50 A and 50 B in the apparatus of FIG. 3 with the particle orienting rollers 36 shown in FIG. 5 . The film B comprised three layers of polymers particles all oriented along a direction parallel to the travelling direction of the paperboard (i.e. 0°, 0°, 0°). The results are as follows:
Film A
Film B
(0°, 45°, 0°)
(0°, 0°, 0°)
Film Weight
MVTR
Film Weight
MVTR
(g/m 2 )
(g/m 2 /day)
(g/m 2 )
(g/m 2 /day)
17
2
17
4
As it is apparent, the film A has better moisture vapor barrier an the film B.
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The invention relates to a substrate coated with an oriented multilayer polymeric film comprising at least two layers of polymer particles oriented along two different directions with respect to one another. Such an oriented multilayer polymeric film has improved flexibility as well as improved gas barrier properties. A method of forming the film on a substrate is also disclosed.
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FIELD AND BACKGROUND OF THE INVENTION
This invention relates to cable feeding devices in general and, in particular, to a new and useful device for depositing a cable having a plurality of filaments, in particular, a cable of chemical fibers in a can or container, with the cable being wound from the outside on a receiving body by means of a sorting arm or distributor, with the spirals thus produced being detachable from the receiving body by means of a transport device, and with the receiving body, which is in itself rotationally movable in the rotating distributor, being prevented from rotating, contactlessly or respectively with the use of force- or form-locking means.
DESCRIPTION OF THE PRIOR ART
In the production of staple fibers, the filaments spun from a nozzle are, in a manner known per se, joined to cables in a first step and then deposited in cans or containers. In known can depositions, which operate at speeds up to 1500 m/min., the cables are deposited directly into the cans by means of toothed rollers.
At higher operating speeds, which are desirable from the viewpoint of reducing the staple fiber manufacturing costs, the impingement energy of the cable is so great, however, that the cable spirals already deposited in the can would be churned. Owing to this, it is practically impossible to draw the cable properly from the can during the next following operation. To counteract such undesirable phenomena or to avoid them, it is customary to reduce the deposition speed by either upsetting the cable or depositing it in wave shapes. Particularly at great cable thicknesses, however, this method has proven to be impractical.
It is further known to reduce the deposition speed by forming a helical cable column from the extended cable in the air which then deposits in the can by itself. To produce such a column, either curved pipes or turbo-distributors are used. It has proven to be rather difficult, however, to deposit such a cable column formed in the air in the can, without rotation, because even at optimal design of such rotary distributors, the cable column is found, in practice, to invariably be more or less unstable. Such instability necessarily leads to overwinding and slipping of the already deposited cable spirals and finally to disarray. This disarray frequently is the cause of interruptions in further processing.
To remedy these and similar situations, it is customary to decelerate the cable column in the direction of rotation by depositing the cable in a pipe or in the interior of a cage formed by rods. However, because of the high speed of rotation of the distributor, it is practically impossible to remove the spirals, thus decelerated downwardly, quickly enough by gravity alone. To provide some remedy to this problem, it is known to transport the spirals formed on the inner wall of the pipe or cage downwardly by means of a veil of air or to use a cage formed by conveyor belts, in order to lay the spirals of the cable directly on the cage.
Even if, with the above described measures, the cable spirals can be prevented from the undesired rotation while still transporting them reliably, such a procedure has the general disadvantage that it requires a high centrifugal force, for one thing, to draw the cable from the feed rollers, and secondly, to cause it to make contact on the inner wall of the pipe or cage.
Measures and procedures such as those described above are therefore tied to minimum speeds, which depend on the type of fiber used, the cable thickness, and the spin finish, among other things. Moreover, they require a relatively expensive cable feed, in order to have to apply little tension, to the extent possible, for drawing the cable into the rotary distributor.
Another procedure which has become known aims to wind the cable on a stationary body by means of a rotating distributor and then to detach the spirals thus produced from it. This method has the advantage that, due to the overfeed of the distributor relative to the godets, any desired tension can be set. This method can thus be used for all speeds and cable thicknesses. In addition, the deceleration of the cable spirals in the direction of rotation is ensured, particularly since the spirals, due to their traction, exert a pressure directed radially inwardly on the receiving body and thereby supply the necessary frictional force themselves. At high speeds, however, the tension required for drawing the cable off of the godets and for overcoming the centrifugal force during winding on the receiving body is very great. Consequently, an equally great pressure is imparted to the receiving body. However, as this pressure is preserved after the depositing, it is extremely difficult to again detach the cable spirals from the receiving body and to transport them into the can.
It is also known to design the receiving body in a conical form and to detach the spirals from it by vibration. Such a procedure can be employed with some prospect of success only at relatively low winding tensions. As such low winding tensions are insufficient to draw the cable off of the godets at high speeds, this mode of pushing off is unsuitable in practice. A suitable method of detachment of the spirals from the receiving body and the manner in which the stationary body is to be mounted must therefore be regarded as still unsolved. Even if its support should be successful, in whatever manner employed, it still remains problematical inasmuch as access to the receiving body from above is hindered by the rotating distributor, and from below, by the falling cable column.
In German Pat. No. 929,123, although for a different area of application in textiles, a solution for the mounting of a detaching body and the detaching of the filament spirals from this body has been proposed.
Here, the receiving body is rotatably mounted in the rotary distributor and it is prevented from rotating from the outside. The wound helical spirals are converted to flat spirals and are then spooled on a spool. Detachment of the spirals from the receiving body occurs by means of conveyor belts which are arranged in slots in the receiving body and which push the spirals across the coil former. The conveyor belts are driven from within by the rotary distributor through a worm drive.
SUMMARY OF THE INVENTION
The practical application according to the invention further to be discussed here differs very essentially from the proposal according to German Pat. No. 929,123 by the fact alone that not filaments, but relatively thick cables are received, and that the cable spirals are not to be spooled but deposited in cans as helical spirals at very high speeds. Although the solution already proposed according to German Pat. No. 929,123 is quite advantageous, it certainly cannot be transferred to the practical application given here, as the conveyor belts proposed as the transport means are by no means sufficient to detach the thick cable spirals from the conveyor belts after they have been wound on them with great tractive force.
A major defect also exists in the solution proposed according to German Pat. No. 929,123 especially in that the transport means are driven from within, so that besides the bearing friction moment, the drive moment of the transport means is also transmitted to the receiving body and must be absorbed by force- or form-locking means acting from the outside.
Building on the solution proposed in German Pat. No. 929,123, the present invention has set itself to the task of showing at least one practical means of a solution to bring about the detachment of the cable from the receiving body in a simple and expedient manner and of keeping the torque exerted on the receiving body, which is to be absorbed from the outside, as low as possible.
This problem is essentially solved by constructing a transport device with at least one pusher firmly connected with a rotary distributor whose receiving body cooperating with it comprises means by which it, together with matching further means, essentially arranged in a stationary outer ring, is prevented from participating in the rotational movement originating from the rotary distributor. In a development of the idea of the invention, these means, as well as the matching further means, comprise permanent magnets which are known per se.
Another solution which is as simple as it is low in cost, comprises a pusher having a pusher surface which extends over almost the entire circumference and has different slopes or which may be stepped or wavy.
Accordingly, an object of the invention is to provide a device for depositing cable into a receiving can or container which includes means for feeding the formed cable into a rotary distributor which includes a tube through which the cable passes which has a central inlet and a lower discharge which moves relative to the surface of an annular receiver which is mounted for relative driving motion relative to the distributor and which further includes a pusher mechanism for engaging the successive coils as they are formed around a receiver pushing them downwardly in a direction to deposit the coils successively into a receiving can or container.
A further object of the invention is to provide a cable depositing device which includes a drive mechanism associated with a receiver around which coils are wound and which is effective to push the coils in succession downwardly off of the receiver into a receiving can or container.
Another object of the invention is to provide a method of feeding cable, after it is formed, into a receiving container which comprises, directing successive coils of the cable around an annular receiver, which is oriented above a receiving container and pushing the coils as they are formed downwardly along the receiver surface and into the container.
A further object of the present invention is to provide a device for depositing cable into a receiving container which is simple in design, rugged in construction and economical to manufacture.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which preferred embodiments of the invention are illustrated.
BRIEF DESCRIPTION OF THE DRAWINGS
In the Drawings:
FIG. 1 is a schematic representation of a cable forming and cable depositing device, constructed in accordance with the invention;
FIG. 2 is a partial side elevational view, partly in section, indicating the receiver shown in FIG. 1;
FIG. 3 is a view similar to FIG. 1 of another embodiment of the device;
FIG. 4 is a view similar to FIG. 1 of a further embodiment of the device;
FIGS. 5, 6, 7 and 8 are views similar to FIG. 1 of still further embodiments of the device of the invention;
FIG. 9 is a partial sectional view through the driving and counter discs shown in FIG. 5; and
FIG. 10 is a schematic bottom plan view of the device shown in FIG. 5 indicating the driving connection between the cable pusher elements.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings in particular, the invention embodied therein in FIG. 1, comprises a cable forming and cable depositing device, generally designated 50, in which a cable 5, after it is formed of many chemical fibers 2, from the different spinning chimneys 1, which are guided through spin finish means 3 and then into the cable depositing device portion of the machine.
In FIG. 1, the filaments 2 emerging from the spinning chimneys 1 are passed over spin finish means 3 and godets 4 and are lastly joined to form a cable 5. Cable 5 is then passed over additional godets 6 and 7 of a can depositing device. More specifically, the device consists of an injector nozzle 8, a rotary distributor 9, a receiving body 10 and several endless belts or chains 12 having pins distributed at spaced locations along its circumference. The chains are guided over guide sprockets 12a and 12b. The injector nozzle 8 projects contactlessly into the rotary distributor 9 and blows the cable at the beginning of the deposition process through a rotating tube 13 of the rotary distributor 9. Tube 13 is rotated with the distributor 9 to deposit the cable 5 on the stationary receiving body 10.
In FIG. 1, the detaching of the individual spirals of cable 5 from the receiving body 10 occurs, for example, by means of pins 11, which are fastened on the moving chains 12 and engage in longitudinal slots 14 (FIG. 2) of the receiving body 10. The number of chains 12 and their arrangement around the circumference of the receiving body 10 can be chosen and designed as desired. The drive of chains 12 is combined positively, in a manner which has not been shown, with the drive of the rotary distributor 9, namely, so that a pin 11 penetrates into a slot 14 of the receiving body 10, only after tube 13 of the rotary distributor 9 has passed the respective slot 14.
Receiving body 10 is rotatably mounted in the rotary distributor 9. The bearing 15 required for this purpose may be arranged, according to FIG. 1, in the rotary distributor 9, or alternatively, it may be arranged in a reversal of this principle, namely, in the receiving body 10. Due to the bearing friction, the receiving body 10 has a tendency to rotate. However, it is prevented from doing so by the pins 11 of the chains 12 meshing with the slots 14 distributed at spaced locations around the circumference of the receiving body 10. In order to achieve an exact conduction of the cable 5 by means of pins 11, and in order not to interfere with the penetration of pins 11 into slots 14, the slots taper radially inwardly and downwardly (FIG. 2). The exact conduction of pins 11 is always effected by means of pins 11 in engagement in the lower region. In this case, however, the receiving body 10 consists preferably of circularly arranged rods or ribs widening downwardly, rather than of a slotted tube. The pins matching them then engage in the rod gaps or the like, tapering downwardly, in analogy to the slots 14.
Cable 5, which is stripped off of the receiving body 10 by pins 11, is deposited into the rotating can or container 16. The diameter of the spirals of cable 5 is about the same or greater than the radius of container 16. This results in the advantage that an additional changover can be dispensed with. It is possible, in addition, to dispense with a drive of container 16 by suspending the entire depositing device for pendulum motion and letting it circle over the can.
In the depositing device 50' according to FIG. 3, the cable 5 is deposited by the rotating tube 13' onto a receiving body 10' and is pushed off of the latter with the aid of a pusher 17. Pusher 17 is firmly connected with the rotary distributor 9', namely, in the direction of rotation, behind a depositing tube 13'. Due to its inclined pushing surface, pusher 17 pushes the deposited spiral downward and thus makes room for the next spiral.
In order to prevent the receiving body 10', mounted in the rotary distributor 9', from rotating, its shell is provided with several magnets 18. Magnets 19, opposite to magnets 18, are correspondingly formed and arranged in the stationary outer ring 20. Preferably, at the end of the push-off region, the receiving body 10' is offset slightly inwardly, so that the pushed-off spirals will fall without contact over the lower portion of the receiving body 10' required for the magnets 18 and 19. Pusher 17 may vary in width and may also have different slopes. It may even extend over the entire periphery of the receiving body 10 and have a constant or a variable slope. In addition, the push-off surface may be stepped or wavy. Naturally, several pushers 17 may also be distributed over the circumference of the receiving body 10, owing to which cable 5 can then be pushed off step-by-step.
At the beginning of the deposition process, the starting end of cable 5, blown in by means of the injector nozzle 8 of the FIG. 1 and FIG. 3 embodiments, must be retained briefly or clamped, to make it possible for spirals to form on the receiving body 10'. This takes place, for example, by means of pins 21, which engage in several bores 22 distributed over the circumference of an outer ring portion 20 and are moved at the start of the laying far enough inwardly for them to make contact with the receiving body 10'. The starting end of cable 5 deposits on the crown or rim formed by the pins 21. The resulting friction is sufficient to ensure application against the receiving body 10'. At the same time, the pins 21 ensure that the receiving body 10 is clamped during the mooring process and is not, for instance, due to a start-up jerk, set into rotation as the magnetic force is overcome.
As soon as cable 5 is moored, pins 21 are moved outward. Retraction and extension of these pins occurs either automatically or manually by means of a linkage, which has not been shown.
The depositing device 50", according to FIG. 4, corresponds in principle to that according to FIG. 1. However, the pins 11" serving to push off the spirals of cable 5 are fastened to revolving discs 23, rather than to revolving chains. Distributor 9" with tube 13" and body 10" with slots 14" act as respective parts 9', 13', 10' and 14 in FIG. 3.
In the depositing device 50'" according to FIG. 5, discs 24''' are rotatably mounted in the receiving body 10'". For this purpose, any desired number of such discs can be distributed over the periphery. In an annular body 25 disposed around the receiving body 10'", matching counter-discs 26 are arranged. These counter-discs 26 are drivable, and they are pressed against the discs 24'''. Cable 5 is deposited on the discs 24''' as a kind of polygon by means of the depositing tube 13, and immediately after deposition, the cable 5 is transported downwardly by cooperative action of the discs 24''' and 26. The spirals or cable 5 pass between discs 24''' and 26, so that, during operation, the drive of the discs 24''' occurs across the spirals of cable 5. To compensate thickness fluctuations in cable 5, the discs 26 may, for example, be mounted elastically in any known way, for example. In addition, discs 24''' and 26 may be formed so that they interengage form-lockingly and, in that way, prevent the receiving body 10''' from rotating, such as shown in FIG. 9. Alternatively, if necessary, discs 24''' and 26 may be readily arranged obliquely to the normal passing through the center of the receiving body 10''', for instance, so that they absorb the torque of the receiving body created by the bearing friction, as shown in FIG. 10.
In the depositing device described above and illustrated in FIG. 5, the winding tensions may be as high as desired. Also, it is by no means necessary in this proposed solution to arrange or provide counter-discs 26 opposite all of the discs 24'''. It may suffice to associate counter-discs 26 with only some of the discs 24''' and it is even possible to dispense with the counter-discs 26 altogether. When cable 5 is placed on the discs 24''' below the point of rotation of these discs, a moment is exerted on the discs due to the traction of cable 5, whereby, they are automatically set in rotation.
The depositing device 50"", according to FIG. 6, corresponds in principle to that according to FIG. 5. In the variant solution according to FIG. 6, however, the counter-discs are replaced by revolving belts or bands 27 which act with discs 24'''' mounted on body 10''''. As these are elastic in themselves, a special elastic suspension can naturally be dispensed with.
The distributors 9''' and 9'''' of FIGS. 5 and 6, respectively, act in a similar fashion to the distributor 9 of FIG. 1 which all include tubes 13.
The pins 11 and 11'' of FIGS. 1 and 4 respectively mounted on their respective belts and discs, as well as the outer discs 26 of FIGS. 5 and 8 in the outer belt 27 of FIGS. 6 and 7 comprise outer peripheral pusher members disposed around the periphery of the respective receivers for engaging the pushing the cable windings 5 which are wound around the receivers from an outer periphery thereof.
The depositing devices 50A and 50B, according to FIGS. 7 and 8 are further variations of the proposed solution specifically described and represented in FIG. 5. In the device according to FIG. 7, belts or bands 27 and 28 are inserted in both the annular outer body 25 and in the receiving body 10 whereas, in the device according to FIG. 8, belts or bands 28 are inserted in the receiving body 10 while discs 26 are arranged in the annular outer body 25.
As shown in FIG. 5, and as exemplary of drive means for the embodiments of FIGS. 5, 6, 7 and 8, each and every disc or belt pulley is driven by a bevel gear 32 which is meshed with a bevel gear 31 driven in turn by a pulley 30 rotated by a belt 29. Each disc or belt pulley is driven by its own bevel gear 31 with pulley 30 which, in each embodiment may be rotated by a common belt 29. The elastic mounting of pulleys 27 may be accomplished for example by providing a spring 33 which permits only very slight movements of disc 26, which movements only correspond to the thickness of the yarn or cable 5. The movement therefore of disc 26 is small enough to be taken up by sliding relative movement between meshed gears 32 and 31.
The depositing devices according to FIGS. 7 and 8 have the additional advantage that the spirals of cable 5 are not subsequently reduced in diameter, as is found to be necessary in the devices according to FIGS. 5 and 6 for reasons of space.
The common feature of FIGS. 5, 6, 7 and 8 is that, in each embodiment, the receiving bodies 10''', 10'''', 10 and 10 carry inner rotating members having smooth or continuous outer peripheries which are exemplified by pulleys 24''', 24'''' and belts 28. On an outer annular body are mounted a plurality of outer rotary members each having smooth or continuous outer peripheries exemplified by annular bodies 25 which carry either discs 26 or belts 27. The cable 5 is moved between the peripheries of these two rotary members and positively pulled downwardly off the receiving bodies.
While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.
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A device for depositing a cable into a receiving container or can, comprises, a rotary distributor including a rotatable cable distributing tube extending obliquely downwardly in the distributor which has an inlet into which the cable is directed adjacent the center of rotation and a cable discharge adjacent its bottom disposed at a location spaced radially outwardly of the cable inlet. The cable receiver has a side with a curved periphery which is located adjacent the tube in a position to receive cable which issues out of the outlet of the tube and engages around the surface of the receiver. The receiver is mounted for rotation relative to the distributor so that there is a driving rotation of one relative to the other to effect the deposit of the coils of the cable around the cable receiver. The receiver can is disposed below the receiver to push the coils of cable as they are deposited on the receiver downwardly along the surface of the receiver and then off of the surface into the can.
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CROSS-REFERENCE TO RELATED APPLICATIONS
The present application claims priority to U.S. Provisional Patent Application 61/849,277 entitled Sound Deadening Board filed on Jan. 23 2013, the content of which is hereby incorporated by reference herein in its entirety.
FIELD OF THE INVENTION
The present disclosure relates generally to affecting sound within a space by absorbing, controlling, and/or isolating the reflection of sound. More particularly, the present disclosure relates to a sound control system for covering surfaces within a space to control and/or reduce the sound within the space and/or the sound transfer between spaces. Still more particularly, the present disclosure relates to a system of sound deadening boards, which may perform multiple functions, including sound control, sound absorption and/or sound isolation.
BACKGROUND
In an increasingly noisy and close-quarters world, sound diffusion and leakage from room to room or unit to unit is becoming an increasingly pressing issue in terms of enjoyment of peace and quiet in one's abode, place of work, etc. Separately, within a particular room, especially a large room, various surfaces can reflect too much sound, creating a live, reverberant environment, making conversation difficult and making sound quality suffer in general.
To combat these issues, sound tiles, thicker walls and extra layering in construction have been used with varying levels of success. Various technical measurements, such as STC (Sound Transmission Class) can be employed to give a simple representation via a single number such as “54” to represent how much a particular partition in a building prevents noise from reaching the adjacent room. A higher number represents a greater sound dissipation, and the example of 54 would mean that a substantial amount of sound would be blocked, but a significant portion would transmit through the medium. Generally dBA (decibels acoustic) or SPL (sound pressure level) is used to represent the efficacy of various discrete strata within the audible-to-human portion of the sound spectrum.
Sound control devices have long been used in music rooms, such as recording studios and band and orchestra rooms at various educational institutions to combat the issue of unwanted reverberation and noise within a particular room. More recently, these technologies have also seen use in home theater, music rooms and general household living rooms, with the goal of improving sound quality, without necessarily having the goal of preventing sound leakage into the adjacent room or rooms. For devices used to absorb sound, not isolate it, a Sound Absorption Coefficient is generally given, with different ratios from 0.0 to 1.0 for various segments of the audible spectrum, roughly corresponding to ranges like the human voice, to lower ranges, as would befit a home theater with a powerful sub-bass range response. A value of 1.0 being the highest and denoting total sound absorption for a given device, i.e., sound waves that hit the device do not reflect back once they have touched the device.
Typically, however, unless a building is built with the intent of including sound control or isolation, the costs involved in retrofit are prohibitive for most consumers. When a building is built with these features, the walls or floors will generally be thicker, denser or more expensive than a typical house or other building would have. Alternative to initially building the room to control sound is the option of adding tiles, boards or other external insulation to existing structure. Tiles and materials sold have generally been made from highly synthetic materials and have been rather expensive and/or unsightly, especially in terms of inexpensive or home use. Furthermore, the existing external solutions to the problem have been relatively heavy, requiring strong adhesives or fasteners in order to keep the devices attached to the walls, and this can lead to unsightly fasteners being visible externally.
The aesthetic element is especially critical because many currently-offered after-the-fact (after a particular room or building has been constructed and finished) solutions to these sound issues have unusual or unsightly appearances in rooms that often tend to be used for entertaining visitors or other guests who may be surprised to find odd-looking objects affixed to the walls or ceiling, oftentimes at odd angles and colored and textured differently than the rest of the room.
SUMMARY
In one embodiment there is disclosed a sustainable, linear sound deadening board, which can be mounted to interior walls, ceilings, etc. of a room, comprising an outer surface, an inner surface, an upper end, a lower end, a left end, and a right end of the board; an interlocking mechanism allowing the board to interface with other replications of identical boards on either side of the board; a plurality of layers; wherein the layers comprise cellulose or other post-consumer or biodegradable material. A tongue and groove design is utilized in preferred embodiments by offsetting layers below the tongue, allowing one board to couple to other similar boards on either side. Other interlocking mechanisms can also be utilized, such as a finger interlocking mechanism or shipped lapped joints. The board comprises a plurality of layers, generally alternating the directionality of grain at 90-degree rotations or substantially perpendicularly, with such layers composed of cellulose, other sustainable, biodegradable, or re-used material.
In another embodiment, A sustainable sound deadening board is disclosed, comprising a plurality of layers in sandwich-like construction including a bottom layer, an intermediate layer on top of the bottom layer and a top layer on top of the intermediate layer, each layer being of a selectable material particularly adapted to affect sound, wherein the intermediate layer is shifted horizontally relative to the bottom layer creating a tongue and groove affect.
The board has lightweight construction, permitting easy fastening of the board to various surfaces, such as a wall or ceiling in a room of a dwelling, commercial building, or industrial building. Lightweight construction also reduces the cost of manufacturing and solves other problems typically associated with the machining or milling of the interlocking joints. This board also allows more ease in installation by minimizing the cuts required by the installer. The interlocking joint created by offsetting layers integral to the ends of the invention allow for the installer to cut only once at the beginning and end of each row. No back cutting or bevel cuts are required to join each piece.
The board can be covered with various materials, including cloth, paper, vinyl, metal or other material used to finish the surface of the board that is visible from inside the room, thus giving a more attractive appearance to that board. The layers of cellulose, cardboard or other sustainable material can be, for example, corrugated cardboard or similar products. By using such materials on the outside of the board only, a more affordable product is created.
The board's layers of cellulose, cardboard, sustainable material, or synthetic material can be of varying thicknesses and numbers of layers, thus giving the board more widespread and advantageous sound properties. By varying the thickness of each board or set of boards, the product can utilize available retrofit products of common thickness. For example, the board may be applied to an existing wall or ceiling and common extensions may be added to the existing electrical boxes. Likewise, the layers of cellulose or other sustainable material can be of varying densities or arrangements, further enhancing the efficacy of the board.
This board provides a single-product solution to an ongoing problem experienced by many users, both residentially and professionally, of effectively and cost-effectively deadening the sound in a room and sound leaking from a room and purchasing an environmentally friendlier product and customizable product unlike many products currently on the market. The clever design of an example embodiment utilizes a novel approach to linking various boards, while also hiding the fasteners, such as staples or nails, holding the boards to the edges and walls of a room, or other surface, such as a ceiling.
BRIEF DESCRIPTION OF THE DRAWINGS
These as well as other objects and advantages of this sound deadening board will be more completely understood and appreciated by referring to the following more detailed description of embodiments in conjunction with the accompanying drawings of which:
FIG. 1 is a top view of a system of adjacent sound-deadening boards.
FIG. 2 is a top perspective view of a layered sound-deadening board of the system of FIG. 1 .
FIG. 3 is an exploded cross-sectional view of a sound-deadening board of the system of FIG. 1 .
FIG. 4 is a top view of a sound-deadening board of the system of FIG. 1 showing a top board and a bottom board that are not vertically aligned.
FIG. 5 is a side view of a sound-deadening board of the system of FIG. 1 showing a top board and a bottom board that are not vertically aligned.
FIG. 6A is a side view of two adjacent sound deadening boards of the system of FIG. 1 showing a top board and a bottom board that are not vertically aligned.
FIG. 6B is a bottom view of a sound-deadening board of the system of FIG. 1 showing a top board and a bottom board that are not vertically aligned.
FIG. 7 is a top view of a sound-deadening board of the system of FIG. 1 showing a top board and a bottom board that are not vertically aligned.
FIG. 8 is a perspective view of two adjacent sound deadening boards.
FIG. 9 is a side view of two adjacent sound deadening boards.
Although the subject matter is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit the disclosure to the particular embodiments described. On the contrary, the invention is to cover all modifications, equivalents, and alternatives.
DESCRIPTION
The present disclosure, in some embodiments, relates to a system of sound deadening and/or absorbing boards that may be placed on surfaces such as walls or ceilings within a space to control the sound therein. The boards may be generally elongate boards and when assembled into a system may provide a pleasantly aesthetic system with a series of parallel extending elongate elements. This may be in contrast to other known sound control systems that are more patchy and aesthetically obtrusive. The boards may be of layered construction allowing the overall effect on sound to be customizable based on the selection of the material used in the several layers. In addition, the assembly of the boards into a system may allow them to interlock to form a larger array of boards having a unified appearance and allowing for large expansive systems to be installed, while avoiding warpage or other out-of-plane distortion.
Referring now to FIG. 1 , a sound control system is shown. The system may include an assembly of sound control elements such as sound deadening boards. The sound control elements may be arranged in a generally rectangular-like array where the several elements are extending generally parallel to one another and are placed end-to-end as well as adjacent to other elements in the array. The end-to-end placement and adjacent placement may include an interlocking or other substantially tight fit allowing for the assembly to appear as a unified or at least assembled series of elements. The system may be sized, shaped, placed, and oriented on a surface and configured to affect the sound within the space. It is to be appreciated that considerations may be given to aesthetics, durability, finish, and other factors when considering how to select the size, shape, placement, and orientation of the system.
In one example, the sound control system can be used in an educational band room where the system is configured to control sound created from a variety of instruments at unpredictable volume levels. In the same example, the system may be configured to isolate and absorb as much sound as possible to prevent noise leakage and diffusion to other unwanted quarters. In another example, the sound control system may be used in a home or commercial theater setting where volume levels are generally more predictable. In the theater system example, preventing sound leakage into the adjacent room or rooms may or may not a primary goal of the sound control system. However, the sound control system may be configured and designed for improving the sound output quality for audiences.
In some embodiments, the system may be used to cover all or substantially all of a wall or ceiling. In other embodiments, a lesser portion of the wall or ceiling may be covered and one or more panels of the system may be used to affect the sound in the space. The elongate nature of the system may allow for plank-like, or slat-like sections of the system to be installed to affect aesthetics together with sound. In other embodiments, other geometrical shapes may be included. In some embodiments, a rectangular or angled orientation of a panel may be used. In other embodiments, the panel or panels may be in a parallel plane adjacent a wall or ceiling or the panel may be tipped relative to the wall and out of plane with the wall. The panels may be placed high or low or at intermediate heights of a wall or along the sides or middle of a ceiling structure. Still other sizes, shapes, locations, and orientations may be used.
As shown, in some embodiments, the system may include an assembly of sound control elements where a large portion of the elements are substantially the same or even identical. In some embodiments, all of the elements in a system may be substantially the same and in other embodiments, all of the elements in a system may be substantially the same except for end or edge elements that may be cut to fit or to affect the size or shape of the system. Given the similar nature of the several elements used to make up the system, the remaining portion of the specification may focus on a particular element of the system.
As shown in FIG. 2 , a perspective view of a sound control element is shown. The sound control element may include a plurality of layers including a bottom layer, an intermediate layer, a top layer, and a finish layer. The plurality of layers of the sound control system may be constructed from materials of varying source, density and thickness. The sound control element may be configured to affect sound when sound waves are imparted thereon. Moreover, the element may be configured to be assembled in a sound control system such as the ones described above. The particular layers may be selected to affect sound in a particular way and some of the layers may be different than other layers or all of the layers may be the same or similar material. In some embodiments, some layers may be adapted to allow sound through in one direction, but resistant to allowing sound travel the opposite direction when some sound waves are reflected back in the direction of the source. Lower layers may be sound absorbing layers, for example. Still other arrangements of layers may be provided.
Each sound-deadening board is assembled to sit on top of, below, or on the side of a same or similar sound-deadening board. By using boards that are roughly the same depth, a linear effect is created when a series of elongated boards of similar material are assembled together. The linear effect of the board is also exemplified when the adjacent boards connect as so to not expose any part of the wall or mounting base.
As shown in FIG. 3 , an outermost layer 400 may be provided and may wrap around the outside of a single-sound deadening board, which can be selected from a cloth, paper, vinyl, metal or other material. The covering portion may be selected to address issues of aesthetics, sound, and other factors. The covering portion may be arranged relatively taut across the backing or top layer and may be secured to the backing or top layer with adhesive. In some embodiments, the covering portion may be secured to an underside of the top or backing layer with adhesive, staples, or other securing systems. Still other securing systems or devices may be used.
In addition, a top horizontal or backing layer 100 may be included as one of the three horizontal layers that comprise the sound-deadening board. Any given layer of the sound control system may be constructed of multiple plies. For example, referring now to FIG. 3 , a top horizontal layer 100 and a bottom horizontal layer 300 are both comprised of double ply layers. The top layer 100 may be positioned to sit above a middle horizontal layer 200 in each sound-deadening board. The top horizontal layer 100 of each sound-deadening board may be the layer that becomes exposed on the mounting surface. The top layer 100 may include a portion with flutes extending in the long direction in addition to a portion with flutes extending in the short direction. Thus, it may be desirable to wrap this top horizontal layer 100 with a covering portion 400 both to create a good aesthetic, but also close off areas where the flutes may be exposed as shown in FIG. 2 .
The top or backing layer 100 may include chamfered edges 500 , extending along the length of the layer and may also include chamfered edges on the ends of the layer 600 . The top view of the system as shown in FIG. 1 reflects a pleasant aesthetic due to the chamfered edges 500 , 600 . In other embodiments, the chamfer may be omitted and a more rectangular profile may be provided.
As shown in FIG. 2 , the top horizontal layer 100 also includes a portion with flutes extending along the length of the board 700 and along the width of the board 700 . Any given layer may be made up of one or more sub-layers of material with same or differing grain orientations from other surrounding layers of the sound control system. Differing grain orientations allow for an elongated assembly of the boards because the varying grain (i.e., the flutes) allow the particular layer to resist bending or warpage in multiple directions.
Referring now to FIG. 3 , a middle horizontal layer 200 may be oriented to sit between the top horizontal layer 100 and a bottom horizontal layer 300 . The middle horizontal layer 200 may be offset horizontally from the top layer 100 and the bottom horizontal layer 300 . This offsetting of layers may create a tongue and groove effect. The tongue and groove effect may allow for a continuous network of the sound-deadening boards, allowing them to interlock with each other in a seamless fashion. The bottom horizontal layer 300 may be oriented to sit adjacent to the mounting base or wall that the sound deadening board is fixated or secured to.
Referring now to FIGS. 4 and 5 , in one embodiment, the top horizontal layer 100 and the bottom horizontal layer 300 may not be vertically aligned with each other in one or more directions. In this embodiment, on the tongue side/end of the board the bottom horizontal layer 300 may extend more horizontally outward than the top horizontal layer 100 to help support a relatively flexible tongue. This embodiment may be useful for sound deadening board arrangements wherein the middle horizontal layer 200 is made from a more flexible material. The extension of the bottom horizontal layer 300 thus acts as a support to the middle horizontal layer 200 by supporting a portion of the length that extends outward from the middle horizontal layer 200 . Where the tongue portion of the board is used for placement of a fastener, the extending bottom layer 300 may support the inner portion of the tongue during placement of fasteners through this inner portion of the tongue.
In one embodiment, a fastener 800 is inserted through a tongue on a middle horizontal layer 200 at an angle near the base of the tongue before another board is placed adjacent to this board. An opposite side of the adjacent piece, which may be a tongue from a middle horizontal layer, is fastened by repeating this fastening approach. This process pins the adjacent board to the first board. The ability of the board to hide a fastening device 800 in an adjacent board, paired with the covering material 400 of the boards, leads to an aesthetically pleasing appearance of the boards, belying the true, logical and inexpensive nature of the underlying apparatus and board.
The array of horizontal layers allows customizability of the sound deadening board. Each layer of the system can be made from the same or different material, allowing users to construct their system from a mix of cellulose or other post-consumer or biodegradable material. The ability of each layer to be made from different material also allows a variety of combinations of different layers to be used for specific, particular purposes. For example, referring to FIG. 8 , in one embodiment, the top horizontal layer 100 may be constructed from different material than the bottom horizontal layer 300 . In another embodiment, all three horizontal layers may be made from the same post-consumer, biodegradable or synthetic material but the wrap material 400 may be a different material than the horizontal layers.
The tongue and groove aspect of the board is just one example of an interlocking mechanism that may be used to connect adjacent boards. In one embodiment, multiple tongues protrude from a single board and are able to interlock with adjacent grooves. In another embodiment, a ship lapped or finger interlocking mechanism may be utilized to interlock adjacent boards.
Referring now to FIG. 8 , two replications of an embodiment of the device is shown. In this embodiment, the top horizontal layer 102 is vertically aligned with the bottom horizontal layer 302 of the embodiment. In this embodiment, the bottom horizontal layer 302 does not extend to support the tongue of the embodiment which, in this example, is the middle horizontal layer 202 . In this embodiment, the tongue of the interlock system may be made from a stronger material that is able to support itself during the interlocking process because of the lack of support from an unextended bottom horizontal layer 302 .
Referring now to FIG. 9 , a side view of two adjacent sound-deadening boards is shown. In yet another embodiment, a middle horizontal layer 202 , acting as a tongue in an interlocking mechanism, may not be supported by a bottom horizontal layer 302 . In this embodiment, the top horizontal layer 102 is vertically aligned with a bottom horizontal layer 302 .
Persons of ordinary skill in the relevant arts will recognize that the subject matter may comprise fewer features than illustrated in any individual embodiment described above. The embodiments described herein are not meant to be an exhaustive presentation of the ways in which the various features of the subject matter may be combined. Accordingly, the embodiments are not mutually exclusive combinations of features; rather, the subject matter may comprise a combination of different individual features selected from different individual embodiments, as understood by persons of ordinary skill in the art, and are within the scope of the following claims.
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A sustainable linear sound-deadening board with a tongue and groove design, which allows multiple boards to connect linearly and giving a both clean and attractive appearance. The board is effective in reducing reverberation within a room as well as acting to improve the soundproofing aspect of undesired sound leaking from one room to another. The board can be made from reused or biodegradable materials thus creating a device that is both cost-effective and less harmful to the environment.
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BACKGROUND OF THE INVENTION
This invention relates to a signal synthesizer for producing pulses simulating the characteristics of echo pulses generated during ultrasonic scanning techniques. Such pulses can then be used for calibration of equipment for processing the outputs of ultrasonic transducers.
FEATURES AND ASPECTS OF THE INVENTION
According to the present invention there is provided a signal synthesizer comprising means for generating a high frequency pulse train, means for producing an envelope having a rising edge, a falling edge and a plateau between those edges, means for selectively varying the rise and fall times of said edges of the envelope, means for varying the duration of the envelope, means for multiplying said envelope with, on the one hand, said high frequency pulse train and with, on the other hand, a substantially zero amplitude signal to provide two outputs having superimposed feedthrough components introduced by the multiplying means, and means for combining the output signals to derive a calibration signal substantially free of said feedthrough components.
Preferably means is provided for effecting phase shift of said pulse train with respect to the envelope.
The multiplying means employed in the present invention may be a dual matched multiplier such as the AD539 device manufactured by Analogue Devices. By using the device as indicated above, it is possible to achieve accurate multiplication involving high frequency signals while freeing the calibration signal from feedthrough components without any filtering.
Means may be provided for varying the amplitude of the calibration signal, for example by means of a switched attenuator connected to the output of the combining means.
The combining means may be a differential amplifier for effecting subtraction of one multiplied output from the other.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described by way of example only with reference to the accompanying drawings, in which:
FIGS. 1A and 1B together form a schematic block circuit diagram; and
FIGS. 2A to 2M illustrate the nature of the signals prevailing at certain points in the circuit.
DESCRIPTION OF PREFERRED EMBODIMENT
Referring to FIGS. 1A and 1B, a fixed frequency 20 MHz oscillator 10 is connected to a counter 12 which, in conjunction with a shift register 14, serves to produce four 5 MHz outputs 16 which are phase shifted by 90° with respect to one another. Any one of the outputs 16 may be selected by phase selection circuitry 18, eg. manually operable switches located on a control console, and coupled to a dual multiplier (see FIG. 1B) via buffer amplifier 20, analogue switching circuitry 22 (eg. FET switches) and buffer/low pass filter section 24 which blocks frequencies exceeding 5 MHz.
The output of the counter 12 is connected to a divider chain 26 which provides a gating pulse on line 28 which may define a gating period and three pulse trains on lines 30, the pulse trains being different subdivisions of the gating pulse, eg. so that there are 1, 2 or 4 pulses respectively within the gating interval (see the waveforms of FIGS. 2A, B, C and D). FIG. 2A represents the gating pulses and it will be noted that the other three waveforms are sub-multiples of this. The pulse trains on lines 30 govern whether the calibration signals produced will simulate a single echo or a multiple echo response, ie. 1, 2 or 4 echoes in the example illustrated.
Selection of a single or multiple echo simulation is effected by means of circuitry 32 which may comprise a number of manually operable switches for routing the signal on a selected one of the lines 30 to circuitry 34 for controlling generation of the envelope of the simulated pulses. FIGS. 2E, 2F and 2G illustrate the waveforms that may be applied to the circuit 34, according to the selection made. The control circuitry 34 also receives inputs from circuits 36, 38 and 40 which determines other parameters of the pulse envelope, namely envelope duration (circuit 36), pulse rise time (circuit 38) and pulse fall time (circuit 40). The circuits 36, 38 and 40 each include manually settable switching means for effecting adjustment of the respective parameters.
In the illustrated embodiment, the circuit 32 may also be used for controlling the relative timing of the simultated echo pulses in relation to the leading edge of the gating pulses, ie. so as to simulate echos returned from targets at different positions. In this context, it will be seen that the leading edges of the pulse trains on lines 30 (see FIGS. 2B and 2D) subdivide the gating pulse (FIG. 2A) into one, two or four and consequently the leading edges of the echo pulser provide seven timing increments with respect to the leading edges of the gating pulses. In a modification however, the pulse timing facility may be divorced from the single/multi echo selection circuit 32.
The envelope control circuit 34 includes a capacitor charging and discharging of which governs the rise and fall times of the envelope. The circuits 38, 40 may include a number of resistors (or resistor combinations) which can be selectively coupled to the capacitor to vary the CR time constant of charge or discharge and thereby adjust the rise and fall time of the envelope. The circuit 36 serves to produce a timing pulse whose duration determines the duration of the plateau of the envelope, as will be explained further below.
The output side of the capacitor is connected to the dual multiplier (FIG. 1B) via buffer section 44, operation of the analogue switching section 22 being controlled by the envelope control section so that the switches are closed only for the duration of the envelope. The envelope signal produced at the output of circuit 34 is coupled to a comparator section 46 which is also coupled to a potentiometer. The circuit 48 enables the amplitude of the envelope to be set to a selected fixed value.
In operation, when the generation of the envelope is initiated by a pulse from selection circuit 32, charging of the capacitor commences and follows the usual exponential curve, the time constant being determined by means of circuit 38. Thus, the output of the circuit 34 follows the voltage level of the capacitor and this, in turn, is compared by circuit 46 with the predetermined amplitude set by the potentiometer. When the capacitor voltage level reaches this preset value, the capacitor is open circuited to prevent further charging and a pulse from circuit 36 is then generated to maintain this condition for the required length of time during which time the output of the circuit 34 will remain substantially constant at the amplitude value preset by means of circuit 48. When this time duration is completed, in response to the trailing edge of the pulse applied by circuit 36, the capacitor is coupled to a selected resistor or resistor combination associated with circuit 40 so that the capacitor proceeds to discharge with a preset time constant. The falling voltage level is compared by circuit 46 with a zero reference level and when the latter level is reached, the comparator section 46 produces an output to reset the envelope control circuit in preparation for the next cycle of envelope generation.
The envelope generated and supplied to the multiplier must not go negative. This is ensured by buffer 44. As shown in FIG. 2H, the envelope will be seen to comprise a rising edge 50, a falling edge 52 and a constant amplitude plateau 54. Although the rising and falling edges are of an exponential nature, they may be substantially linear if only a minor part of the exponential curves associated with the capacitor (and resistor combination) are utilized. The transition points 56 will in general be of a discontinuous nature and are therefore potential sources of high frequency components during subsequent handling by the multiplier. FIG. 2M illustrates the wave form of the 5 MHz signal and it will be understood that this will be confined to a time interval corresponding to the duration of the envelope, ie. by virtue of a control signal applied to the switching section via line 60. This is indicated by the waveform as depicted at 2I which illustrates the envelope of the 5 MHz signal without showing the fine detail of the high frequency signal.
Referring now to FIG. 1B, the signals on lines 62, 64 are applied to the dual matched multiplier 66 which is constituted by the circuit component AD539 manufactured by Analogue Devices. This device has two sets of multiplier inputs, ie. 68, 70 and 72, 74 and outputs 76, 78. The outputs 76, 78 provide the products of the signals applied to the inputs 68, 70 and to the inputs 72, 74 respectively. A feature of the AD539 device is that it is capable of accurately multiplying signals of up to 60 MHz with signals of up to 5 MHz. As shown, the inputs 68 and 72 serve to handle signals up to 60 MHz while inputs 70 and 74 handle signals of up to 5 MHz. In the illustrated embodiment, the envelope signals are applied to inputs 70 and 74, the 5 MHz carrier signal is applied to the input 68 and the input 72 is connected to the ground plane.
As previously mentioned, the envelope (FIG. 2H) includes discontinuities 56 which can give rise to significant and undesirable high frequency feedthrough components during multiplication. This is offset to some extent by the fact that the inputs 70 and 74 can handle signals up to 5 MHz--nevertheless such undesirable feedthrough components can occur even with the AD539 device. Advantage is therefore taken of the fact that this device is a dual matched multiplier by performing two multiplications, ie. the desired multiplication and a multiplication of the envelope with a zero level signal. The latter multiplication will also suffer from feedthrough and can therefore be used to compensate the desired product signal by subtraction in circuit 80, eg. a differential amplifier. This is illustrated by the waveform of FIGS. 2J and 2L.
FIG. 2J represents the product signal at output 76 from which it will be seen that unwanted feedthrough components 82 are present. Likewise in the case of the product signal at output 78--see FIG. 2K. After subtraction however, the resulting output is substantially freed of the feedthrough components--see FIG. 2L. It will be understood that the waveform of FIG. 2L will be used as an echo simulating calibration pulse and that various parameters thereof can be readily varied, eg. pulse duration, rise time, fall time and timing relative to the gating pulses. In addition, the phase relationship between the envelope and the carrier may be varied.
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A signal synthesizer is provided for producing pulses simulating characteristics of echo pulses generated during ultrasonic scanning so that the simulated pulses can be used in the calibration of equipment for processing the outputs of ultrasonic transducers. The synthesizer produces an envelope signal of selectively variable amplitude and rise and fall time and multiplies this envelope respectively with a high frequency pulse train and a substantially zero amplitude signal in a dual matched multiplier so that the subtractively combined outputs of the multiplier are free of unwanted feedthrough components introduced by the mulitplier.
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BACKGROUND OF THE INVENTION
The present invention relates to a transmission comprising a hydraulic coupling member and a locking or blocking clutch, and more particularly to a motor vehicle transmission of the kind comprising, between an input element which is intended to rotate integrally with a first shaft (generally a drive shaft), and an output element which is intended to rotate integrally with a second shaft (generally a driven shaft), firstly a hydraulic coupling member such as a torque converter, which comprises an impeller wheel rotating integrally with the input element, and a turbine wheel rotating integrally with the output element, and secondly, a locking or blocking clutch, commonly called a "LOCK UP," which, upon starting and generally upon each change of gear ratio is in a first, disengaged, condition in which the hydraulic coupling member alone operatively interconnects the input element and the output element, and which, in a second engaged condition, once the initial starting phase has been completed, renders this hydraulic coupling member inoperative and locks up the transmission so as to eliminate any residual slipping due to said member and so as to improve thereby the efficiency of the whole assembly, by ensuring a direct mechanical coupling between the input element and the output element.
The invention is aimed, more precisely at transmissions of this kind which are intended to be incorporated in motor vehicles.
These can be either transmissions with semi-automatic control or transmissions with fully automatic control.
In practice, in transmissions of this kind, the locking clutch possesses a coupling element which is mounted to be movable axially and which, rotating integrally with the output element, is capable of being made to rotate integrally with the input element by means of friction.
Likewise in practice, for transmissions of this kind, fluid-circulation means are provided which comprise an inlet pipe for supplying fluid under pressure and an outlet pipe for returning said fluid to a collecting tank.
In the prior art, the locking or blocking clutch usually is controlled by adjusting the direction of circulation of this fluid under pressure: in one direction of circulation, the fluid under pressure penetrates into the transmission via a control chamber engaged with or disengaged from the clutch, which is referred to below as the control chamber and which is formed between the coupling element of said clutch and a wall integral with the input element, so that this clutch is then maintained in a disengaged position; for the opposite direction of circulation, the fluid under pressure penetrates into the transmission via the hydraulic coupling member so that it presses the coupling element of the clutch against the said wall of the input element and so that the clutch is, in this way, adjusted to the engaged position.
In practice, the corresponding controls have always been arranged on the exterior of the transmission, on the fluid-circulation means which serve said transmission, and the result is that, to change from a transmission having no locking or blocking clutch to a transmission having such a clutch, it is necessary to substantially modify these fluid-circulation means. This can be difficult and troublesome to carry out, at least for certain applications.
Consequently, provision has been made in the present invention to integrate with the transmission itself, when it has a locking or blocking clutch, the means designed to bring this clutch into, or out of, operation.
In the known arrangement proposed for this purpose, there is provided on the transmission inlet pipe, within the transmission itself, a tubular distributor slide-valve, which, via its central bore, is suitable for permanently serving the hydraulic coupling member, and which, acted upon by elastic means restoring it in the direction of a position of rest, is movable between such a position of rest, in which it blocks a passage, referred to below as the control passage, which causes said inlet pipe to communicate with the control chamber of the clutch, and a working position, in which, by opening said control passage, it permits free communication between the inlet pipe and the control chamber of the clutch, to effect disengagement of said clutch. There are also provided on the outlet pipe of the transmission, on the exterior of this transmission, two passages which are arranged in parallel, each of which is regulated by a controlled clack-valve, said passages thus constituting together means of passage with a variable cross-section which is regulated by said controlled clack-valve.
When these two clack-valves are open the pressure at the outlet of the transmission is relatively low, so that, by means of the pressure at the inlet or the supply pressure, the distributor slide-valve is forced into the working position. This opens the control passage of the clutch and consequently, said clutch is adjusted into the disengaged position.
When the clack-valve which is controlled is closed the pressure at the outlet of the transmission is sufficient to ensure that, as the pressure difference at the inlet and at the outlet becomes less than the load of its elastic restoring means, the distributor slide-valve blocks the control passage of the clutch. The said clutch is then no longer set in the disengaged position and can normally, subject to the then relatively elevated pressure which prevails in the transmission, pass into the engaged position.
Nevertheless, in practice, when the valve is in the position of rest, such an arrangement can fail due to the fact that, since one and the same pressure then prevails on both faces of the coupling element of the clutch, this coupling element is not applied sufficiently energetically to the corresponding wall of the input element.
An object of the present invention is to provide an arrangement which enables this disadvantage to be minimised or avoided.
SUMMARY
The invention provides a transmission comprising a hydraulic coupling member and a locking or blocking clutch, particularly for a motor vehicle, wherein in parallel between an input element which is intended to rotate integrally with a first shaft, generally a drive shaft, and an output element which is intended to rotate integrally with a second shaft, generally a driven shaft, firstly, a hydraulic coupling member such as a torque converter or coupler which comprises, an impeller wheel rotating integrally with the input element and a turbine wheel rotating integrally with the output element, and secondly a locking or blocking clutch, commonly called a "LOCK UP," said locking or blocking clutch comprising a coupling element which is mounted to be movable axially and which, rotating integrally with the output or input element, is capable of being made to rotate, particularly by means of friction, integrally with the input or output element, in combination with fluid-circulation means which comprise an inlet pipe for supplying fluid under pressure and an outlet pipe for returning said fluid to a collecting tank, with on the inlet pipe, within the transmission itself, a distributor element, which, via a bore, is suitable for permanently serving the hydraulic coupling member and which, acted upon by means restoring it in the direction of a position of rest, is movable between such a position of rest, in which it blocks a passage, referred to below as the control passage, which causes said inlet pipe to communicate with a control chamber engaged with or disengaged from the clutch, and a working position, in which, by opening said control passage, it permits free communication between the inlet pipe and the control chamber of the clutch, to effect disengagement of said clutch, and, on the outlet pipe, on the exterior of the transmission, means of passage with variable cross-section which are adjusted by a controlled clack-valve, this transmission being characterised in that said distributor element is adapted to put the control passage of the clutch in communication with the collecting tank.
In this way, when the controlled clack-valve is closed, the coupling element of the clutch can be applied energertically against the corresponding wall of the input element, the control chamber of the clutch being directly linked to the collecting tank, thus permitting the delivery of fluid necessary for this application.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a half-view in axial section of a transmission according to the invention, this transmission being in the rest position corresponding, also, to its "LOCK UP" condition;
FIG. 2 is a view equivalent to that of FIG. 1, with the transmission in the position in which only its hydraulic coupling member is in operation; and
FIG. 3 is a diagram illustrating the operation of this transmission.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a transmission 10 with a hydraulic coupling member 11 and a locking or blocking clutch 12, called a "LOCK UP," of the kind which equips certain motor vehicles.
The transmission can be a transmission with an automatic control system or a transmission with a semi-automatic control system.
Since a transmission 10 of this kind is not in itself the subject of the present invention, it has not been represented in full detail in FIG. 1, particularly as regards its control. In FIG. 1, only the components of the transmission and control system which are affected by the present invention have been more particularly represented.
The hydraulic coupling member 11 and the clutch 12 which comprise the transmission 10, are installed in parallel between an input element consisting of the rotating case 13 of the assembly, and an output element, consisting in the embodiment illustrated, of a tubular hub 14.
The case 13 is intended to rotate integrally with a first shaft 15, generally a drive shaft. A driving diaphragm 16 connects the shaft 15 to the case 13 for this purpose. The case is also fixed on the shaft 15, for the purpose of centering, by means of a stud 17 which projects axially from said case.
The tubular hub 14 is intended to rotate integrally with a second shaft 18, generally a driven shaft, and a grooved fitting 19 is provided for this purpose between the tubular hub 14 and the shaft 18.
In practice, the drive shaft 15 is itself intended to rotate integrally with the output shaft of the engine of a vehicle and in one embodiment may be constituted directly by this output shaft, whilst the driven shaft 18 is intended to rotate integrally with the input shaft of a gearbox, which in one embodiment may be constituted directly by this input shaft.
In the embodiment illustrated, the output shaft 18 is tubular and it surrounds coaxially a central shaft 20, itself tubular, which is intended to drive an accessory, for example an oil pump.
In the embodiment illustrated, the hydraulic coupling member 11 is, moreover, a torque converter: besides an impeller wheel 22 and a turbine wheel 23, it also has a reactor wheel 24; however, it could just as well be a simple coupler, in which case no reactor wheel is provided.
The impeller wheel 22 is fixed directly to the internal wall of the rotating case 13; it therefore rotates integrally with said case which constitutes the input element of the transmission 10.
The turbine wheel 23 is carried by the tubular hub 14 constituting the output element of the transmission 10 and therefore rotates integrally with said hub.
Finally, the reactor wheel 24 is, in turn, carried, via a free wheel 25, by a tubular hub 26, which extends coaxially around the driven shaft 18, a bearing 27 being interposed.
Likewise,a bearing 28 is provided between this tubular hub 26 and the rotating case 13.
Furthermore, a gasket 30 is provided between the tubular hub 14 and the driven shaft 18.
Taken as a whole, the clutch 12 comprises, in the embodiment illustrated, a coupling element 32 and a torsion-damping hub 33.
In the embodiment illustrated, the damping hub 33 is, on its outer periphery, linked to the coupling element 32 by a splined connecting piece, which is the subject of the French patent filed on Apr. 2, 1979 under No. 79/08192. Such a splined connecting piece is not indispensible; on the contrary, other forms of connection can be provided.
On its inner periphery, the torsion-damping hub 33, which is designed in a way known per se and, as it is not part of the present invention, will not be described in detail here, is connected to the tubular hub 14 by the same rivets 35 as those which cause said tubular hub to govern the turbine wheel 23 of the hydraulic coupling member 11.
Furthermore, on its inner periphery, the torsion-damping hub 33 constitutes axially a bush 36 which goes to make up an annular cavity 37 for the tubular hub 14 with which it is integral.
The coupling element 32 of the clutch 12 comprises an annular flange, which, on its inner periphery, is mounted to be movable axially on the bush 36 of the torsion-damping hub 33 by means of a piston cylinder arrangement which is sealed by a gasket 38. In the embodiment illustrated, the said annular flange carries on its outer periphery, an annular friction lining 39, located opposite an annular area 40 of the corresponding transverse wall 41 of the rotating case 13. In an alternative embodiment the friction lining 39 can be carried by the wall 41 of the case.
By means of the friction lining 39, the coupling element 32, which, via the torsion-damping hub 33, rotates integrally with the tubular hub 14 constituting the output element of the transmission 10, is capable of being made to rotate, by means of friction, integrally with the rotating case 13 which constitutes the input element of this transmission 10.
Internally, there projects axially from this rotating case 13 a tubular hub 42, with which the central shaft 20 rotates integrally by means of a grooved arrangement 43, and which, together with the transverse wall 41 of the case 13 and the coupling element 32 of the clutch 12, defines, for this clutch 12, in the embodiment illustrated, an engaged or disengaged control chamber 45, referred to below as the control chamber.
Moreover, this tubular hub 42 possesses axially an annular extension 46, by means of which it engages axially in the annular cavity 37 of the tubular hub 14, an axial bearing 47 being interposed.
Thus, the tubular hubs 14 and 42 penetrate one into the other.
A rotary gasket is provided between these tubular hubs, both on the radially outermost face of the annular extension 46 of the tubular hub 42, namely the gasket 48, and on the radially innermost face of this annular extension 46, namely the gasket 49.
Likewise, a gasket 50 is provided between the tubular hub 42 and the central shaft 20.
Furthermore, a ball bearing 51 is provided between the tubular hubs 42 and 14.
Means of circulating fluid under pressure are provided for the transmission 10. These fluid-circulation means possess an inlet pipe, which, starting from a collecting tank (not shown), is constituted successively by the axial bore 52 of the central shaft 20, a chamber 53 into which this bore 52 emerges at right angles of the transverse wall 41 of the rotating case 13, and a passage 54, which, formed in the tubular hub 42, is capable of enabling the preceding chamber 53 to communicate with the control chamber 45 of the clutch 12 and which constitutes the control passage of said clutch.
Provided on this inlet pipe, within the transmission 10 itself, is a distributor element 55, which, by means of a bore 56, is suitable for permanently serving the hydraulic coupling member. The said element 55, being acted upon by elastic means restoring it in the direction of a position of rest, is movable between such a position of rest, in which, as illustrated in FIG. 1, it blocks the passage 54, and a working position, in which as illustrated in FIG. 2, it opens this passage 54 and thus permits free communication between the inlet pipe, and, more precisely, both the chamber 53 of the inlet pipe, and the control chamber 45 of the clutch 12.
In practice, in the embodiment illustrated, this distributor element constitutes a tubular slide 55, whose bore 56 is the central bore. The said distributor element is mounted movably in a bore 57 of the tubular hub 42, which emerges at right angles to a passage 58 formed obliquely in the tubular hub 14, starting from the bottom of the tubular cavity 37 of the tubular hub 14 at the base of the turbine wheel 23, so as to serve the volume encompassed between this turbine wheel 23 and the impeller wheel 22, said volume being the internal volume of the hydraulic coupling member 11.
Preferably, and as illustrated, the bore 57, in which the distributor element 55 is accommodated, extends, according to the invention, parallel to the axis of the whole assembly, so that this distributor element is movable parallel to this axis, without a component of movement which is due to centrifugal force; however, without departing from the scope of the invention, it can be inclined slightly to the axis of the whole assembly or, in other words, be only substantially parallel to this axis, such that the component of movement, which is due to centrifugal force, is sufficiently small to be acceptable.
In practice, the restoring means associated with the distributor element 55 are, in the embodiment illustrated, constituted by a spring 59. In the embodiment illustrated, the said spring 59 bears on an elastic split ring 60, which is arranged in a groove of the tubular hub 42, at the end of the bore 57 of the tubular hub 42 which is opposite the transverse wall 41 of the rotating case 13. In an alternative embodiment, this spring can bear on the bottom of the bore 57, if this has such a bottom, or on the piece located at the end of this bore.
To return the fluid under pressure to the collecting tank, the fluid-circulation means associated with the transmission 10 possess an outlet pipe, which possesses, in particular, starting from the internal volume of the hydraulic coupling member 11, a passage 62, formed transversely in the tubular hub 26, and an annular passage 63, formed between this tubular hub 26 and a bush 64 fitted to the inner periphery thereof, around the driven shaft 18.
This annular passage 63, communicates, via a passage 65 in the tubular hub 26, with an exterior pipe 67, which is indicated by a partly broken line in FIG. 1.
Arranged in this pipe 67, which is connected to the collecting tank, are means of passage of variable cross-section, which are adjusted by means of a controlled clack-valve 70. In the embodiment illustrated, these consist of two parallel passages 68, 69.
The passage 68, has a smaller cross-section than the passage 69 and is free.
The passage 69, which is of larger cross-section, is adjusted by the controlled clack-valve 70.
For example, and as illustrated, such a clack-valve 70 can be driven by the plunger 71 of an electromagnetic relay 72. The said clack-valve is permanently acted upon in a direction in which it leaves the passage 69 open, by means of a spring 73 which bears on the frame 75 of the whole assembly and which acts on the plunger 71.
According to the invention, the tubular slide constituting the distributor element 55 is adapted to put the control passage 54 of the clutch 12 in communication with the collecting tank. Preferably, and as illustrated, this slide has two bearing surfaces 76, 77 and, between these, it has a portion of reduced outer cross-section 80, which is suitable for enabling the control passage 54 of the clutch 12 to communicate with an outlet port 81 connected to the collecting tank.
In practice, this outlet port 81 causes the bore 57 of the tubular hub 42 to communicate with the chamber 82, which is formed jointly by the tubular hub 42, the tubular hub 14, the driven shaft 18 and the central shaft 20.
This chamber 82 is connected to the collecting tank by, successively, an annular passage 83 between the driven shaft 18 and the central shaft 20, a passage 84 provided transversely in the driven shaft 18, an annular passage 86 between the driven shaft 18 and the bush 64 surrounding same, this bush thus isolating this passage 84 from the above-described outlet pipe, and a pipe 87, which, as indicated by an arrow in FIG. 1, rejoins the collecting tank.
A bearing 88, constituting a sealing gasket, is provided between the driven shaft 18 and the central shaft 20, beyond the passage 84 of the driven shaft 18 relative to the outlet port 81, in order to prevent any detrimental leakage between the driven shaft 18 and the central shaft 20.
At rest, with the drive stationary, as in FIG. 1, the clack-valve 70 leaves the passage 69 open, the tubular distributor slide-valve 55 blocks the passage 54 and the coupling element 32 of the clutch 12 occupies an intermediate fixed position, the friction lining 39, being possibly, but not necessarily, in contact with the area 40 of the transverse wall 41 of the rotating case 13.
Upon starting a motor vehicle equipped with the transmission or upon a change of gear ratio, the clack-valve 70 is immediately closed against the action of the spring 73.
As a result, the two passages 68, 69 of the outlet pipe are initially operative and they jointly ensure a considerable flow of fluid.
The incoming fluid, which penetrates via the bore 52 of the central shaft 20, as indicated by the arrow F 1 of FIG. 1, reaches the chamber 53, as indicated by the arrow F 2 . Then, via the bore 56 of the slide constituting the distributor element 55 and via the passage 58 of the tubular hub 14, the said fluid reaches the internal volume of the hydraulic coupling member 11, before arriving at the outlet pipe.
Since the cross-section of passage of said outlet pipe, which is due to the passages 68, 69, is then relatively large, the pressure at the outlet 11A of the hydraulic coupling member 11 is at a relatively low level P 1 , as indicated by a continuous line in the diagram of FIG. 3, in the left part of this diagram.
Under the effects of the pressure P' 1 of the fluid entering the chamber 53, which pressure, as indicated by broken lines in the diagram of FIG. 3, is deliberately larger than the pressure P 1 because of the exact calibration of the bore 56, the passages 68, 69 and of the spring 59, the slide constituting the distributor element 55 is forced from left to right against this spring 59. The passage 54 of the tubular hub 42, which constitutes the control passage of the clutch 12, is therefore uncovered and the control chamber 45 of the clutch is supplied with fluid under pressure. The said clutch is therefore adjusted to the disengaged position, its coupling element 32 moving away from the transverse wall 41 of the rotating case 13, according to FIG. 2.
Consequently, the hydraulic coupling member 11 is operative between the input element and the output element of the transmission 10 only at starting and at each change of gear ratio.
This situation continues until a square-wave voltage pulse is sent to the relay 72 controlling the clack-valve 70, as indicated at C on the line T of the diagram in FIG. 3.
The clack-valve 70 then blocks the passage 69, as indicated by broken lines in FIG. 1, so that the flow rate of the outlet pipe is, from that moment, limited to that allowed by the passage 68.
Consequently, the pressure at the outlet of the hydraulic coupling member 11 rises to the vicinity of a level P 2 , higher than the preceding level P 1 , and is held there, as indicated by a continuous line in the diagram of FIG. 3, in the middle part of this diagram.
Under the effects of its restoring spring 59, the distributor slide-valve 55 returns to its position of rest, according to FIG. 1, in which it blocks the control passage 54 of the clutch 12. The inner chamber 45 of said clutch is then no longer supplied with incoming fluid under pressure. On the contrary, via the outlet port 81 it is connected to the collecting tank, which acts as a discharge reservoir.
As a result, the pressure in this inner chamber 45 of the clutch 12 falls progressively, the outlet port 81 being calibrated for this purpose, to a pressure level P 0 which is that of the collecting tank.
The coupling element 12 is therefore subjected, in this case, to a differential pressure, which increases and which acts upon it in the direction of the transverse wall 41 of the rotating case 13.
Consequently, this coupling element 12 progressively applies its friction lining 39 against the area 40 of this transverse wall 41, thus ensuring that the clutch 12, of which it forms part, is progressively brought into the engaged position.
When this engagement is completed, a direct mechanical connection is established, by means of the clutch 12, between the input element and the output element of the transmission 10, the hydraulic coupling member 11 of the latter thus being rendered inoperative; nevertheless, it continues to be supplied with fluid via the bore 56 of the distributor element 55, the pressure necessary to apply the coupling element 12 against the transverse wall 41 of the rotating case 13 being obtained by means of an exact calibration of the bore 56, of the passage 68 and of the spring 59.
No residual slipping therefore exists any longer in the transmission 10, once the starting phase, or the initial phase of a change of gear ratio, has been completed.
This situation continues as long as the square-wave voltage pulse C is applied to the relay 72.
When this voltage is stopped, for example upon a new change of gear ratio, the clack-valve 70 is, again, controlled to opening, which brings the pressure at the outlet of the hydraulic coupling member 11 down to the level P 1 and the pressure in the inner chamber 45 of the clutch 12 to the level P' 1 , as before, as indicated in the right-hand part of the diagram of FIG. 3.
In an alternative embodiment, the clack-valve 70 can be closed in a position of rest; however, it is advantageous if it is open for such a position of rest, since, in the case of failure of the electrical circuit, only the hydraulic coupling 11 will remain operative.
The shaft 20 provided for driving, for example, an oil pump can be eliminated, and this oil pump can, for example, be driven directly by the rotating case 12; the distributor element 55 is, in this case, accommodated in a bore by means of a turbine and the whole assembly is supplied with fluid via the shaft 18.
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A transmission is disclosed comprising a hydraulic coupling and a lock-up clutch, a tubular distributor slide valve element provides permanent communication between the hydraulic coupling member and an inlet conduit and controls fluid flow between the inlet conduit and a clutch control chamber for operating the lock-up clutch. The distributor valve member comprises two relative large diameter portion therebetween. In the closed position of the distributor valve member the control chamber is brought into communication with an outlet conduit for returning the fluid from the control chamber to a storage tank.
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BACKGROUND OF THE INVENTION
The present invention refers generally to an electromotive drive mechanism for a piece of furniture, and in particular to an electromotive drive mechanism of a type having a gearmotor in driving connection with a gearing having an output member for rotating an adjusting spindle and thereby moving a nut, disposed on the spindle, in longitudinal direction of the spindle.
Drives for furniture are utilized in a variety of application, e.g. for adjusting swingable parts of a slat frame bed for hospital beds, for treatment chairs, TV chairs or similar pieces of furniture. The furniture drive can be configured as single drive with one gearmotor and one adjusting spindle, or as twin drive with two gearmotors and two adjusting spindles. Conventionally, the gearing positioned between the gearmotor and the spindle is designed as worm drive, with the worm being mounted on the driven pin of the gearmotor for reducing the relatively great speed of the gearmotor, and with the wormgear being mounted on a shaft oriented at a right angle thereto and linked to the adjusting spindle. This type of electromotive drive is applicable only for smallest outputs with a power of a few 100 watts. The speed of the adjusting spindle should be relative small to enable a slow adjustment of the piece of furniture.
There is a desire to provide drives of this type of compact design to fit the limited space available in the piece of furniture for which these drive are used. While compact designs for furniture drives have been proposed, their dimensions are still too bulky. Moreover, efforts are made to keep the power being drawn as small as possible in order to reduce the energy consumption. This objective is however difficult to reconcile with the need to provide the furniture drive with a self-locking gear unit because the efficiency of conventional self-locking gear units is in the range of 0.5 so that the energy loss is respectively high.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an improved electromotive drive mechanism for pieces of furniture, obviating the afore-stated drawbacks.
In particular, it is an object of the present invention to provide an improved electromotive drive mechanism which is of simple design and exhibits smaller outer dimensions compared to conventional designs, and which is characterized by a reduced power consumption while yet maintaining a self-locking gear unit and still attaining a substantially enhanced efficiency.
These objects, and others which will become apparent hereinafter, are attained in accordance with the present invention by providing a gear unit for connecting a gearmotor, which has a rotor rotating about a rotational axis, to an adjusting spindle that is operatively connected to a piece of furniture and rotates about a rotational axis which extends parallel and at a distance to the rotational axis of the rotor, with the gear unit including a first pair of meshing helical gears for reducing the output speed of the gearmotor as transmitted to the spindle.
The outer dimensions of a drive mechanism according to the present invention are significantly reduced compared to conventional designs because the provision of axes that extend perpendicular to one another is omitted. The parallel disposition of the adjusting spindle relative to the rotational axis of the rotor could conceivably be effected by differently designed gear transmission, e.g. multistage spur gear unit, planetary gear train, or bevel gear unit; However, the multistage configuration does not permit a desired, compact configuration. Moreover, spur gear units are not self-locking so that their application for pieces of furniture is unsuitable. Moreover, the multistage configuration decreases the overall efficiency.
The use of a helical gear unit is possible for application with pieces of furniture because the output of an electromotive drive for furniture is relatively small, and has the advantage of not only effecting a desired speed reduction but also maintaining the parallelism between the rotational axes of the rotor and of the spindle. The helical gear unit attains a significantly greater efficiency than worm gears, e.g. in the range of approximately 0.8 to 0.9, and can be so configured as to effect a self-locking action so that the power consumption can be accordingly reduced. The self-locking action is of great efficiency while still allowing mutual compensation of axial forces. Thus, the use of separate brakes becomes unnecessary as is required in conventional drives which have parallel axes and shafts.
Preferably, the gear unit includes two pairs of meshing helical gears, with the first and second pairs of helical gears exhibiting a different nominal diameter whereby the helical gear of the first and second pairs of helical gears, positioned on an output end, is of a greater diameter than the helical gear of the first and second pairs of helical gears, positioned on an input end. The helical gear on the output end is always the gear downstream in force transmission direction. As the arrangement of two helical gears effects a compensation of axial forces, the configuration of the housing for the drive mechanism can be simplified.
A structurally simple solution for this type of gear unit is effected when securely mounting the helical gear of the first pair of helical gears on the input end and by securely mounting on an intermediate shaft the greater helical gear of the first pair of helical gears on the output end and the helical gear of the second pair of helical gears on the input end which meshes with the greater helical gear of the second pair of helical gears.
According to another embodiment of the present invention, the gear unit includes a first pair of helical gears and a second pair of meshing spur gears with straight or oblique teeth, whereby preferably oblique spur gears exhibit an addendum modification with a minimum number of teeth and a greatest possible transmission ratio. This embodiment is conditioned on the attained self-locking action, speed and required transmission ratio and is of simple construction because spur gears with straight or oblique teeth are commercially available components. Suitably, as viewed in transmission direction, the pair of spur gears is positioned ahead of the pair of helical gears.
The position of the gearmotor relative to the adjusting spindle can be best suited to existing installation conditions. It may be possible to position the gearmotor laterally next to the spindle or on the opposite side of the housing of the drive mechanism.
BRIEF DESCRIPTION OF THE DRAWING
The above and other objects, features and advantages of the present invention will now be described in more detail with reference to the accompanying drawing in which:
FIG. 1 is a sectional view of one embodiment of a drive mechanism for a piece of furniture, in accordance with the present invention;
FIG. 2 is a sectional view of another embodiment of a drive mechanism for a piece of furniture, in accordance with the present invention;
FIG. 3 is a schematic illustration of a variation of the drive mechanism of FIG. 1 with modified points of attachment of the drive mechanism to the piece of furniture; and
FIG. 4 is a schematic illustration of a variation of the drive mechanism of FIG. 2 with modified points of attachment of the drive mechanism to the piece of furniture.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Throughout all the Figures, the same or corresponding elements are always indicated by the same reference numerals.
Turning now to the drawing, and in particular to FIG. 1, there is shown a sectional view of one embodiment of a drive mechanism for a piece of furniture, in accordance with the present invention, generally designated by reference numeral 10. The drive mechanism 10 includes a multipart housing formed by a main body 12, a housing portion 11 which extends outwardly from the main body 12 and a housing portion 29 which projects outwardly from the main body 12 substantially parallel to the housing portion 11 at a distance thereto. The housing portion 11 accommodates a gearmotor 13 whose rotor (not shown) is linked to one end of an output shaft 19. Persons skilled in the art will appreciate that the gearmotor may be of any suitable type and thus is shown only schematically for sake of simplicity.
The other end of the output shaft 19 is formed as journal 19a which is rotatably supported by the main body 12. The main body 12 houses a gear unit which is composed of two pairs of helical gears 14, 15; 16, 17, with helical gear 14 securely mounted on the output shaft 19 for conjoint movement with the output shaft 19. The helical gear 14 is in mesh with the helical gear 15 and has a diameter which is smaller than the diameter of the helical gear 15. The helical gear 15 is securely mounted on an intermediate shaft 18 for conjoint movement therewith, with the intermediate shaft 18 being rotatably supported at both axial ends by the main body 12. The helical gear 16 is positioned laterally next to the helical gear 15 on the intermediate shaft 18 and has a diameter which is smaller than the diameter of the helical gear 15. In mesh with the helical gear 16 is the helical gear 17 which is securely mounted on one end 20a of an adjusting spindle, generally designated by reference numeral 20. The spindle end 20a is devoid of any thread and is rotatably supported via bearings 30 by the main body 12. Thus, the gear unit is of two-step configuration, with the helical gears 14 and 15 forming one pair of helical gears and the helical gears 16 and 17 forming the other pair of helical gears, thereby effecting a significant reduction of the speed of the gearmotor 13.
The plain spindle end 20a terminates in a threaded shank 20b. Mounted on the shank 20b is a nut 22 which is secured against execution of any rotational motion. Thus, at rotation of the spindle 20, the nut 22 travels in a linear movement along the shank 20b. The nut 22 is securely fixed to a lift-adjusting pipe 23 which moves conjointly with the nut 22. The lift-adjusting pipe 23 surrounds the spindle shank 20b at formation of a gap 31 therebetween and projects beyond the main body distant end face 29a of the housing portion 29.
The attachment of the drive mechanism 10 to and adjustment of a piece of furniture (not shown) effected via a fork head 21 which is secured to the nut-distal free end of the lift-adjusting pipe 23 by a fitting 21a that is formed with a socket to receive the proximal end of the spindle shank 20b and is press-fitted in the gap 31. Mounted to the end face of the main body 12, opposite to the fork head 21, is a further fork head 24 for enabling a secure attachment of the drive mechanism 10 to the respective piece of furniture.
It will be appreciated by persons skilled in the art that the drive mechanism 10 must contain much mechanical apparatus which does not appear in the foregoing Figure. For example, the drive is typically operated by a control system to allow adjustment of the piece of furniture to an intended position, or includes limit switches and other safety features such as manual switches, to prevent damage to the device or injury to the user in the event of improper operation or equipment malfunction. However, this apparatus, like much other necessary apparatus, is not part of the invention, and has been omitted from the Figure for sake of simplicity.
At operation, actuation of the gearmotor 13 transmits the speed outputted by the rotor onto the output shaft 19 and is reduced by the gear unit for transmission to the spindle 20. A rotation of the spindle 20 causes the nut 22 to travel in a linear direction along the spindle shank 20b. The movement of the nut 22 is directly transmitted onto the lift-adjusting pipe 23 and the fork head 21 to thereby adjust the position of the piece of furniture.
Turning now to FIG. 2, there is shown a modification of the drive mechanism 10, with the difference to the embodiment shown in FIG. 1 residing in the positioning of the gearmotor 13 and the configuration of the gear unit. As in FIG. 1, the gearmotor 13 is positioned laterally next to the spindle 20 so that the rotational axis of the rotor of the gearmotor 13 extends parallel at a distance to the center rotational axis of the spindle 20. In accordance with the embodiment of FIG. 2, the motor housing 11 is positioned as a mirror image of the motor housing 11 of FIG. 1 so as to illustrate the feasibility of this type of installation.
The gear unit of the drive mechanism 10 of FIG. 2 includes one pair of spur gears 25, 26 and one pair of helical gears 16, 17, with spur gear 25 securely fitted on the output shaft 19 and meshing with the spur gear 26 of comparably greater diameter. The spur gear 26 is wedged onto the intermediate shaft 18 on which also the helical gear 16 is securely fitted. The helical gear 16 is in mesh with the greater helical gear 17 which is secured on the plain spindle end 20a. Although FIG. 2 shows the pair of spur gears 25, 26 as being positioned before the pair of helical gears 16, 17, as viewed in force transmission direction, the inverted disposition is certainly also possible.
In both embodiments, the helical gears 14, 15, 16, 17 are formed as twin helical gears with central radial groove 32. The teeth of the helical gears, positioned laterally on both sides of the radial groove 32 are slanted in opposite direction or exhibit an arrow-like configuration. In this manner, the gear unit runs smoothly and can be subjected to a relatively high load, whereby generated axial forces compensate each other.
FIGS. 3 and 4 show by way of example variations of positional dispositions of the motor housing 11 in relation to the adjusting spindle 20. In FIG. 3, the gearmotor 13 is again positioned laterally next to the spindle 20 in a manner shown in FIGS. 1 and 2. Mounted to both parallel and spaced outer end faces of the spindle 20 are further fork heads 27, 28 at a position transversely to the fork head 21 for provision of additional points of attachment of the drive mechanism 10 to the piece of furniture. Certainly, a mirror image disposition i.e. an arrangement turned by 180° is also possible.
FIG. 4 shows a variation of the drive mechanism 10 which is formed with axially opposing fork heads 21, 24 in a same manner as shown in FIGS. 1 and 2, with the difference residing in the positioning of the motor housing 11. In accordance with the embodiment of FIG. 4, the motor housing 11 is mounted to the main body 12 on the end face distant to the spindle 20. Also in this embodiment, the rotational axis of the rotor of the gearmotor 13 is oriented parallel and at a distance to the central longitudinal axis of the spindle 20, i.e. an offset disposition is effected between the rotor axis and the spindle axis.
The respective position of the motor housing 11 relative to the spindle 20 can be selected and suited to existing installation conditions and applications, so long as the central longitudinal axis of the spindle is offset to the rotational axis of the rotor of the gear motor 13.
While the invention has been illustrated and described as embodied in a electromotive drive mechanism for a piece of furniture, 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.
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An electromotive drive mechanism for a piece of furniture, includes a gearmotor having a rotor rotating about a rotational axis, an adjusting spindle for operation of a piece of furniture, and a gear unit connecting the spindle to the rotor of the gearmotor for rotating the spindle about a rotational axis, with the rotational axis of the rotor extending parallel and at a distance to the rotational axis of the spindle. The gear unit includes a nut placed on the spindle for movement in longitudinal direction of the spindle when the spindle rotates, and a first pair of helical gears which are in mesh with one another for reducing the output speed of the gearmotor as transmitted to the spindle.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This is a national stage application under 35 U.S.C. §371(c) of prior-filed, co-pending PCT patent application serial number PCT/GB2009/051683, filed on Dec. 10, 2009, which claims priority to British patent application serial number 0901432.5, filed on Jan. 29, 2009, each of which is hereby incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] Embodiments of the present invention relate to pumps, in particular to pumps for pumping hydraulic well control fluid into a production flowline of a well.
[0004] 2. Description of the Prior Art
[0005] During the operation of a subsea well, hydraulic fluid is expelled from hydraulic control actuating devices, such as valve and choke actuators. Typically, in the past, this fluid has been exhausted to the sea. The fluid is, typically, ethylene glycol based and is now considered to be a pollutant. Environmental legislation now prompts well operators to stop exhausting such fluids into the sea, particularly on new installations, which presents well equipment suppliers with the problem of finding a solution to the new requirements. GB Patent Application No. 0820326.7 discloses a method of disposing of hydraulic well control fluid, comprising pumping the fluid into a production flowline of the well. Although it is possible to effect such a method with an electrically powered pump, a failure of electric power would not allow hydraulic fluid to continue to be exhausted from actuators during the well shut down. Embodiments of the present invention enables a pump that provides the necessary pressure to inject exhausted hydraulic fluid into the production flowline, handles the fluid exhausted during a well shut down and does not need electric power.
BRIEF SUMMARY OF THE INVENTION
[0006] According to an embodiment of the present invention, there is provided a pump for use in pumping hydraulic well control fluid expelled from a control device of a well, comprising means for accumulating such hydraulic well control fluid and means for using the pressure of hydraulic fluid supplied to the well to pump accumulated hydraulic well control fluid into a production flowline of the well.
[0007] Preferably, said accumulating means comprises a cylinder arrangement including a piston, accumulated hydraulic well control fluid acting at one side of the piston for displacing the piston in a first direction, said means for using the pressure of hydraulic fluid supplied to the well applying pressure at the opposite side of said piston.
[0008] According to an embodiment of the present invention, there is provided a pump for pumping hydraulic well control fluid expelled from a hydraulic control device of a well into a production flowline of the well, comprising: a first cylinder arrangement, for accumulating such hydraulic well control fluid via a first inlet to the first cylinder arrangement; a piston in the first cylinder arrangement, expelled well control fluid being accumulated on one side of the piston; a second cylinder arrangement containing hydraulic fluid and in fluid communication with the first cylinder arrangement on the opposite side of the piston, wherein the pressure of expelled fluid accumulating in the first cylinder arrangement can cause said piston to be displaced in a direction towards the second cylinder arrangement, there being means for accommodating the displacement of hydraulic fluid in the second cylinder arrangement; and a further inlet to the first cylinder arrangement on the opposite side of said piston for receiving hydraulic fluid supplied to the well, there being an outlet from the first cylinder arrangement on said first side of the piston for communicating with a production flowline of the well, the pump being such that if said piston has been displaced toward said second cylinder arrangement and if hydraulic fluid is applied to said further inlet at a pressure greater than the pressure of accumulated well control fluid in the first cylinder arrangement, said piston is displaced in a direction away from the second cylinder arrangement to displace accumulated well control fluid out of the first cylinder arrangement via said outlet.
[0009] There could be displacement means (such as a spool) received by said first cylinder arrangement between said piston and said further inlet, there being urging means (such as spring means in said second cylinder arrangement) for urging said displacement means in a direction towards the second cylinder arrangement, hydraulic fluid at said further inlet acting on said displacement means so that, if the pressure of hydraulic fluid at said further inlet is greater than pressure of accumulated well control fluid, said displacement means is displaced against the action of said urging means to displace said piston.
[0010] Each of said first inlet and said outlet is preferably provided with a one-way valve for permitting flow into and out of said first cylinder arrangement respectively.
[0011] Said second cylinder arrangement could comprise a first cylinder in fluid communication with said first cylinder arrangement and a second cylinder in fluid communication with said first cylinder, there being a further piston in said second cylinder, said accommodating means being in fluid communication with the side of said further piston remote from said first cylinder.
[0012] Said accommodating means could comprise an expandable container.
[0013] The pump could include means for sensing pressure of accumulated expelled hydraulic well control fluid to produce an indication for use in increasing the pressure of hydraulic fluid at said further inlet in response to the pressure of accumulated expelled hydraulic well control fluid reaching a particular value.
[0014] According to an embodiment of the present invention, there is provided a method of pumping hydraulic well control fluid expelled from a control device of a well, comprising accumulating such hydraulic well control fluid and using the pressure of hydraulic fluid supplied to the well to pump accumulated hydraulic well control fluid into a production flowline of the well.
[0015] In an embodiment of the present invention, hydraulic power is supplied to a subsea well, typically from a surface source, via an umbilical, at a pressure of 280 bar. This is considerably less than the maximum pressure that the hydraulic system is able to handle. The pump to be described utilises a step increase, typically to 345 bar, of the hydraulic pressure fed to the well, to provide power to operate the pump, such that neither electric power nor a separate hydraulic power source is required. The pump also incorporates a storage system, adequate to contain the expelled fluid during a well shut down, which could result from electrical and/or hydraulic power failure, which is emptied on restoration of hydraulic power. Furthermore no hydraulic fluid is exhausted from the hydraulic operating mechanism of the pump, as the fluid is recycled.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 shows a pump according to an embodiment of the invention in a quiescent state;
[0017] FIG. 2 shows the pump having accumulated expelled hydraulic control fluid according to an embodiment of the present invention;
[0018] FIG. 3 shows the pump having pumped accumulated hydraulic control fluid into a production flowline of the well according to an embodiment of the present invention; and
[0019] FIG. 4 shows an alternative pump construction in the condition of having accumulated expelled hydraulic control fluid according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0020] Referring first to FIG. 1 , which is a diagrammatic sectioned view of a pump in its quiescent position, i.e. ready to accept exhausted or expelled hydraulic fluid, an inlet port 1 is connected to the combined exhaust hydraulic control fluid outlets from hydraulic devices on a subsea well, such valve and choke actuators. When one or more hydraulic devices exhausts fluid, it passes via a non-return valve 2 into a void 3 within a cylinder 4 to be accumulated therein and push a free running piston 5 to the right in the figure. A void 6 within the cylinder 4 is filled with hydraulic fluid and is the same fluid that fills cylinders 7 and 8 and a bladder 9 . The movement of the piston 5 forces hydraulic fluid in the void 6 to pass through an orifice in the centre of displacement means in the form of a spool 10 (whose left-hand end in the figure is received in the cylinder 4 ) and into the cylinder 7 via a non-return valve 11 , which is normally be closed for a flow in this direction, but is held open by a spigot 12 . Fluid flow through the spool 10 forces a tree running piston 13 in the cylinder 8 to move to the right in the figure, thereby forcing hydraulic fluid into the bladder 9 , which expands appropriately.
[0021] The pump is fed with power by hydraulic fluid from the existing well hydraulic supply via a second inlet port 14 communicating with an umbilical of the well, to act upon the face of the spool 10 in the cylinder 4 and tends to push the spool 10 to the left in the figure. However, this is resisted by urging means in the form of a spring 15 in cylinder 7 , whose compression force is adjusted to match the force applied by the well hydraulic power source. Thus, the spool 10 remains in position to the right in the figure, the spring compression being just enough to retain the spool 10 over the tolerance range of the normal operating pressure of the well hydraulic power source.
[0022] The void 3 is thus a storage or accumulation space for expelled hydraulic fluid from the operation of well control hydraulic devices, resulting in the piston 5 eventually moving as far to the right in the figure as it can, being stopped by the left-hand face in the figure of the spool 10 , and fluid in the cylinder 8 being displaced into the bladder 9 . This state is illustrated in FIG. 2 . Further expelling or exhausting of hydraulic fluid into the inlet port 1 results in a rise in this inlet pressure, which is sensed by a pressure switch 16 . Such a pressure switch 16 normally exists already on well hydraulic fluid exhaust systems and is connected electrically, via the well umbilical, to the well control centre at the surface, or on land, where the well hydraulic power source is also located. On receipt of a signal from the pressure switch, the control system step increases the hydraulic pressure at inlet port 14 from the source, i.e. typically, for example, from 280 bar to 345 bar.
[0023] FIG. 3 illustrates the result of this increased pressure, via, the inlet port 14 , acting on the right-hand face is the figure of the spool 10 , producing a force greater than that applied by the spring 15 , resulting in the spool 10 moving to the left in the figure and closing of the valve 11 , since it is moved away from the spigot 12 , and an increase of the pressure of the exhausted hydraulic fluid in the void 3 in the cylinder 4 . An outlet port 17 of the pump houses a non-return valve 18 and is connected, via a pressure release valve, to an injection nozzle in the well production fluid flowline. The increase in pressure in the void 3 closes the inlet non-return valve 2 , and when greater than the pressure in the production fluid flowline, opens the non return valve 18 , allowing accumulated fluid in the void 3 to be disposed of by injection into the production fluid flowline, and resetting the pump to the quiescent state of FIG. 1 .
[0024] If there is a failure of the hydraulic power supply fed to the inlet port 14 , when the cylinder 4 is full of expelled hydraulic fluid, more hydraulic fluid will be available at the inlet port 1 . This is able to enter an overflow cylinder 21 , depressing a piston 22 . The volume of the cylinder 21 is designed to be sufficient to handle all expelled hydraulic fluid resulting from a well shut down. On restoration of the hydraulic pressure at the inlet 14 , the pressure switch 16 operates at the first exhaust of hydraulic fluid via the inlet 1 , resulting in operation of the empty cycle by a step increase of pressure at the inlet 14 . Reference numerals 23 designate holes which perforate the right-hand side in the figures of spool 10 to allow free movement of hydraulic fluid in the cylinder 7 .
[0025] The maximum pressure that can be generated in the void 3 is approximately equal to the increase in hydraulic source pressure at the inlet port 14 , when the internal diameter of the cylinder 4 is constant, and will be adequate to inject fluid into a production flowline whose pressure is less than this. Thus, the available pressure would be 345 bar−280 bar=65 bar approximately. If the production flowline pressure is greater than this, the cylinder 4 could be replaced by two cylinders 19 and 20 as illustrated in FIG. 4 . The ratio of the internal diameters of the cylinders 19 and 20 determines the final available pressure at the outlet 17 . Thus, in the example, the outlet pressure will be 65 bar×(diameter of cylinder 19 /diameter of cylinder 20 ). The pump can therefore be designed either to handle the maximum known production flowline pressure or to suit a particular application. In practice, the ratio of the internal diameters of the cylinders 19 and 20 will have to be substantially greater than that simply calculated, as above, since the available force is reduced as the spring 15 compresses.
[0026] It should be noted that the cylinder 8 and its free running piston 13 are not essential components of this pump, since it will function correctly with the output of the cylinder 7 connected directly to the bladder 9 . However, well operators prefer double isolation of a pump core from the external environment and, since the bladder provides only a single level of isolation from the environment, the cylinder 8 and piston 13 are included to provide a desired second level of isolation. Also, spring 15 could be replaced, for example, by the use of hydraulic pressure for urging spool 10 in a direction to the right in the figures.
[0027] The key advantage of the pump is that it does not require a separate source of power, and operates from a step increase of pressure from the existing well hydraulic power source. Further advantages are a) the hydraulic fluid used by the pump is not expelled or exhausted, but recycled back to its source when the step increase of pressure is reduced to normal operating pressure and b) exhausted or expelled hydraulic fluid from well actuators for example, resulting from a well electric and/or hydraulic power failure, is accommodated by the pump and disposed of by injection into the production flowline when hydraulic power is restored.
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A pump for use in pumping hydraulic well control fluid expelled from a control device of a well, comprises means for accumulating such hydraulic well control fluid and means for using the pressure of hydraulic fluid supplied to the well to pump accumulated hydraulic well control fluid into a production flowline of the well.
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This application is a continuation of application Ser. No. 127,398, filed Mar. 5, 1980, and now abandoned.
BACKGROUND OF THE INVENTION
(1) Field of the Invention
This invention relates to extrusion presses, and more particularly to die transfer mechanisms on extrusion presses.
(2) Description of Prior Art
An extrusion press is utilized to force a heated metal slug or billet through a shaped orifice called a die stack. The die stack is mounted in a carrier which may in turn be supported on a horizontal track or gibs fixed to a massive vertically arranged platen. The die is aligned with a passageway or egress hole in the plate or platen which provides reinforcement thereagainst, while permitting the metal to be forced and extruded therethrough. It is necessary to change the die from time to time to permit changes in the extrusion pattern, or to replace a worn die. Several methods have been proposed in the art and are shown in U.S. Pat. Nos. 2,858,017 to Kent et al; and 3,653,247; 3,844,151 and 4,103,529 to Huertigen. The patent to Kent et al, discloses a die shifter having a first cylinder mounted on the side of the platen adjacent and connected to a die slide assembly, with a second cylinder attached to the platen with a rod which pulls on the bottom of the die slide assembly. Both the first and second cylinders are used to shear the extruded article, whereupon the second cylinder is used to shift the slide slightly from in front of the orifice in the platen to enable an operator to lift the die out through the top of the slide using a crane or the like, and replacing it similarly. The '247 patent to Huertigen shows a die slide with empowering means therefor extending distantly off one side of the press. The '151 patent to Huertigen shows a die slide arrangement using a chain and sprockets adapted to move a die in conjunction with hydraulic unit, to a transfer station. This type of die shifting mechanism is susceptible to contamination from metal particles and necessitates constant cleaning and maintenance of the hydraulic unit components.
It is an object of the present invention to provide a die slide assembly which is compact and unobtrusive.
It is a further object of the present invention to provide a die slide assembly which does not require constant cleaning and maintenance as would some of the prior art.
BRIEF SUMMARY OF THE INVENTION
The present invention comprises a die slide assembly for an extrusion press, the slide assembly including a die seated in a die holder, which die holder is movably supported on a track adjacent one of the platens in the extrusion press. The die holder is shuttleable to a convenient die transfer station on one side of the platen by a dual hydraulic piston and cylinder arrangement. One of the hydraulic cylinders is arranged to be carried by the shuttle mechanism itself to reduce the length of cylinder required to complete the die transfer to the side of the platen. By carrying one of the hydraulic units on the shuttle itself, the length of the piston rod and cylinders is reduced considerably. This design minimizes the overall width requirements for the extrusion press, as well as simplifies the maintenance and operating procedures therefor, by eliminating or restricting portions of the hydraulic unit that would be otherwise exposed to contamination from the scraps generated during extrusion of billets in the machine.
BRIEF DESCRIPTION OF THE DRAWINGS
The objects and advantages of the present invention will become more apparent when viewed in conjunction with the following drawings, in which:
FIG. 1 is an elevational view of a die slide assembly for an extrusion press constructed according to the principles of the present invention; and
FIG. 2 is a sectional elevational view of the empowering means of the die slide assembly.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings in detail, and particularly to FIG. 1, there is shown a portion of an extrusion press 10 comprising a heavy front platen 12 and a heavy rear platen with a main press cylinder mounted therebetween, not shown, the front and rear platesn being connected by an arrangement of four tie rods 14 that take up the thrust of the extrusion operation therebetween. A die stack 16 is supported in a U-shaped die stack holder 18. The die stack holder 18 is movably disposed in a die slide assembly 20. The die stack 16 is of cylindrical configuration, configured orifice(s) having at least one configured orifice 22 which is in line with an orifice or egress hole extending through the front platen 12. The die slide assembly 20 includes a lower support track or gib 24 and an upper support track or gib 26 both attached to and extending off of the rear or inwardly directed face of the front platen 12. An empowering means 30, shown in section in FIG. 2, is arranged to mate with the die slide assembly 20. The empowering means 30 comprises a two-piece frame assembly 32 which is movable transversely of the front platen 12. The frame assembly 32 includes a primary slide block 34. The primary slide block 34 supportively encloses a pressurizable main cylindrical housing 36. A main piston head 38 is slidably arranged within the main housing 36, on a main piston rod 40. The end opposite the piston head 38 of the main piston rod 40 is securely connected to an arm 42 attached to the front platen 12. The main piston head 38 has a plurality of piston rings or seals 44 disposed thereon to prevent pressurizable fluid from seeping therepast. The primary slide block 34 also supportively encloses and secures a pressurizable secondary cylindrical housing 46. A secondary piston head 48 having a plurality of piston rings or seals 54 thereon, is slidably arranged within the secondary cylindrical housing 46, on the distal end of a secondary piston rod 50. The end opposite the piston of the secondary piston rod 50 is connected to a transport slide block 52. The transport slide block 52 and the primary slide block 34 are both arranged in a sliding relationship between the upper and lower support tracks or gibs 26 and 24, and they are in close proximity with one another when both piston heads 38 and 48 are fully retracted in their respective housing 36 and 46.
A "T"-key 58 is secured to the lower edge of the side face of the transport slide block 52. A "T"-slot 60, as shown in FIG. 1, is disposed in the lower portion of one side of the die holder 18. A die hold-down finger 62 is attached to the face of the primary slide block 34. The hold-down finger 62 is disposed parallel to and is spaced apart from the face of the transport slide block 52, and extends through a bore 64 in the die holder 18, permitting it to provide hold-down support to the die stack 16 when a shear blade, not shown, is lifted from alongside the die stack 16. The projecting end of the hold-down finger 62 has a curvilinear or angular surface 66 thereon to contact the periphery of the die ring of the die stack 16 thereadjacent.
A die transfer station 70 is disposed on the side of the front platen 12, opposite the side of the arm 42. The die transfer station 70 comprises a lower support track 72 which may be arranged perpendicular to the die slide assembly 20. A transfer table 75 is slidably mounted on the support track 72, at the level of the die slide assembly 20, which assembly may intersect the lower support track 72 at roughly its mid-point. The transfer table 75 may have another U-shaped die stack holder 74 slidably arranged thereon, and may include a die holder shuttle assembly, such as pressurized cylinders or the like, not shown, for moving the transfer table 75 with the first and/or the second die holder 18 or 74 therewith. It is to be noted that the second die holder 74 has a "T"-slot 76 near the bottom on one side thereof.
In operation of the extrusion press 10, the main press cylinder forces a ram, not shown, to push a billet or slug of material to be extruded through the configured orifice 22 in the die stack 16. The forces generated in the die stack 16 are directed through the die stack holder 18 and the massive front platen 12. The tie rods 14, which are secured to a frame supporting the ram and to the rear platen, not shown, absorb the stresses generated in the extrusion press 10. The tail end of extruded billet may be cut off by a vertically arranged shear, not shown, which shear may be disposed above the die 16 adjacent the middle of the platen 12. When the vertically arranged shear is lifted, there is a drag between it and the face of die stack 16 which tends to lift the die stack 16 in the die stack holder 18. The die hold-down finger 62 prevents vertical movement of the die stack 16 during this portion of the operation.
When a die is to be changed, fluid under pressure from a suitable fluid pressure source, not shown, may be delivered to the proximal end of the main piston shaft 40 through a conduit 41 and passage 43 causing the entire frame assembly 32 to extend to the left as seen in FIG. 2 along the main piston shaft 40 and to traverse across the front platen 12 along the die slide assembly 20. Any extrusion remaining within the die orifice 22 and the coaxial opening in the front platen is sheared off at the plane therebetween. Fluid under pressure may be delivered from the end of cylindrical housing 36 through a conduit 45 (FIG. 1) and a passage 47 (FIG. 2), against the secondary piston head 48 within the secondary cylindrical housing 46, either during pressurization of the main cylindrical housing 36, or after that occurrence, to effect movement of the secondary piston rod 50 out of the primary slide block 34, to cause continued transverse movement of the transport slide block 52 and the die stack 16 and die stack holder 18 thereattached. The die hold-down finger 62 is retracted from its position adjacent the die periphery and is withdrawn through the bore 64 in the die stack holder 18 as the transport slide block 52 is separated from its position adjacent the primary slide block 34. The die stack 16 and the die stack holder 18 can be transferred to the transfer table 75 mounted on the support track 72 on the side of the platen 12.
The transfer table 75 may then be moved by a pressurizable piston and cylinder unit, not shown, away from its association with the transport slide block 52, thus disengaging the die stack holder 18 therefrom by sliding the "T"-slot 60 away from its position enclosing the "T"-key 58, permitting subsequent servicing of the disengaged die stack 18. The new die holder 74, with whatever die may be arranged therewith, none being shown, may be attached to the transport slide block 52 by slidably mating the "T"-slot 76 in the new die holder 74 with the "T"-key 58. Retracting the secondary and primary piston rods 50 and 40, within their respective housings by exhausting fluid pressure from conduit 41 and delivering fluid pressure through a conduit 49, passage 51 and conduit 53 leading from the conduit 49 to the left end of housing 46, effects displacement of the new die holder 74 and whatever die is associated therewith to its proper position at the extrusion position adjacent the front platen 12.
Thus, there has been shown an extrusion press having a die transfer system which eliminates an excessive projection of pressurizable cylinders from the sides of the platen, and which permits a relatively easily maintainable and efficient die shearing operation free from the contamination and size problems associated with the prior art extrusion press machines.
It is intended that the appended claims for the present invention be interpreted as exemplary only, and not in a limiting sense.
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An extrusion press having a die slide assembly capable of shearing the extrusion in the die, and transporting the die to a side movable transfer table for change thereof, the assembly eliminating excessive projection beyond the confines of the extrusion press of die transport equipment. The die slide assembly includes a first hydraulic cylinder for shearing an extrusion from the die, and a second hydraulic cylinder mounted adjacent the first cylinder for transporting the die and die holder to a transfer station on the side of said platen, permitting an exchange of the die holder die therewith, when necessary. The second hydraulic cylinder is movable with the die slide assembly to minimize the length requirements of the second hydraulic unit and still effectuate full traverse of the die holder.
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FIELD OF THE INVENTION
This invention relates to a door closer, herein referred to as being of the kind described, comprising a housing, a member for driving engagement with a door, the member being rotatable relative to the housing in a door opening direction and in a door closing direction, a spring apparatus within the housing providing a resilient bias, the resilient bias being increased by rotation of the member in the door opening direction and a check device for controlling rotation of tie member in the door closing direction and hence closure of the door under the action of the spring apparatus.
BACKGROUND OF THE INVENTION
It is desirable to provide a back check device to resist opening of a door beyond a certain angle, for example, to prevent damage to a wall which could occur if unrestrained opening of the door were permitted.
An object of the present invention is to provide a door closer of the kind described with a new and improved back check.
SUMMARY OF THE INVENTION
According to the present invention we provide a door closer of the kind described having a back check comprising a piston member movable in a cylinder from an initial position against resistance of a fluid medium by rotation of the rotatable member in the opening direction.
Preferably a pair of piston members are movable in opposite directions in a respective chamber against resistance of a fluid medium by rotation of the rotatable member in the opening direction. This provides a compact back check.
The or each piston member may be movable in a direction which is tangential to the axis of rotation of the rotatable member.
The or each piston member may be movable by a cam follower which is engaged with a cam rotatable by rotation of said rotatable member.
Where there are two piston members the cam follower is disposed between the piston members.
Spring, biasing means may be provided to return the or each piston to said initial position.
The or each piston member may be engaged with a spherical intermediate piston member.
Where there are two piston members then, in a first plane, the cam follower is engaged by said intermediate piston members and by said cam to control movement of the cam follower in said plane whilst movement of the cam follower in directions out of the plane is controlled by walls of a passage of the housing from which the cam follower is disposed.
The fluid medium may be passed through a metering valve which permits a user defined rate of flow of fluid therethrough.
The metering valve may be settable to permit adjustment of the rate of flow of fluid therethrough.
The metering valve may be accessible from the exterior of the housing for said adjustment.
A door closing cam may be mounted in the housing for turning relative thereto with the rotary member, the door closing cam being acted upon by a spring-loaded door closing cam follower which is reciprocable relative to the housing along a main axis and which urges the door closing cam towards a door closed position.
The direction in which the or each back check piston member is movable may be transverse to said main axis. Preferably said transverse direction is at right angles to said main axis.
The piston members may be disposed on the opposite side of the axis of said rotatable member to said door closing cam follower.
By providing the piston members for the back check on the opposite side of the axis of rotation of the rotatable member to the door closing and check means by virtue of the transversely movable piston members described hereinbefore a relatively strong back check effect can be achieved without any need for increasing the resistance to opening of the door until the door is substantially open, for example, in excess of 90°.
BRIEF DESCRIPTION OF THE DRAWINGS
An example of a door closer embodying the present invention will now be described, with reference to the accompanying drawings, wherein:—
FIG. 1 is a fragmentary cross-section through a door closer in a vertical plane and with an operating member of the door closer in a rest position;
FIG. 2 is a diagrammatic representation of a cross-section through the door closer of FIG. 1 on the stepped line 2 — 2 of FIG. 1 ;
FIG. 3 is a representation similar to that of FIG. 2 but of a cross-section on the line 3 — 3 of FIG. 1 ;
FIG. 4 is a fragmentary diagrammatic illustration of parts of the door closer as viewed in cross-section on the line 4 — 4 of FIG. 1 ;
FIG. 5 is a diagrammatic plan view, partly in section, of the door closer of FIGS. 1 to 4 showing the components when the door has been opened 15°, from an “at rest” position;
FIG. 6 is a view similar to that of FIG. 5 but when the door has been opened 90 ′;
FIG. 7 is a view similar to that of FIG. 5 but when the door has been opened through 180°, and
FIG. 8 is a view similar to that of FIG. 5 but to which certain internal passages have been added.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The device illustrated in the accompanying drawings comprises a hollow housing 10 in which there is mounted, by bearings 59 , 60 for turning about an axis 11 , a rotary member 12 . An end portion 13 of the member 12 protrudes at the outside of the housing 10 and receives an arm 14 , by means of which the rotary member 12 is connected with a door for turning with the door relative to the housing 10 . Typically, the housing 10 is embedded in a floor and the door is supported for pivoting at the axis 11 . The arm 14 may be attached to the bottom of the door and is typically received in a recess formed in the door. The end portion 13 is non-circular and is received in a complementary opening in the arm at one end thereof. When the door is opened the rotary member is rotated in a door opening direction and in a door closing direction when the door is closed.
There is disposed inside the housing 10 a coiled compression spring 15 and a drive mechanism for transmitting motion between the spring and the rotary member 12 . The drive mechanism is arranged to compress the spring 15 when the door and member 12 are turned in a door opening direction from a rest position. The spring then urges the door and member 12 towards the rest position as a result of rotation of the member being caused in the door closing direction.
The drive mechanism includes three cam and follower mechanisms. The third cam and follower mechanism is essentially a duplicate of the first cam and follower mechanism. The followers of the first and third cam and follower mechanisms reciprocate relative to the housing 10 with a cylinder 16 . The follower of the second cam and follower mechanisms reciprocates with a piston hereinafter described which slides inside the cylinder 16 .
The device illustrated in the drawings is constructed to act as a check on damper and check on damp movement of the door towards the rest position under the action of the spring. It will be appreciated that, without the damping action, the door would be accelerated by the spring throughout movement towards the rest position, which would be unacceptably dangerous. In a case where the door is free to swing in either direction from the rest position, damping also enables the door to be brought to rest, when it reaches the rest position, rather than to pass through the rest position and then to oscillate about the rest position.
The cylinder 16 is mounted inside the housing 10 for reciprocation relative thereto along a main axis 17 of the cylinder. The main axis 17 extends centrally along the length of the housing 10 and either intersects the axis 11 or passes near to that axis. The cylinder 16 has at one end an enlarged, hollow head 18 , on which there is formed a seat for one end of the spring 15 . That part of the cylinder 16 other than the head 18 lies inside the spring 15 . The spring extends beyond the cylinder 16 to a further seat 19 , on which an end of the spring remote from the head 18 bears. The cylinder is open at both of its ends.
The seat 19 is mounted on a carrier 20 which is supported in one end portion of the housing 10 against movement outwards of the housing. The carrier 20 can turn relative to the housing about the main axis 17 and a non-circular end portion 21 of the carrier protrudes from the end of the housing to facilitate turning of the carrier by means of a suitable tool. The seat 19 is annular and has a female screw thread cooperating with a male screw thread on the carrier 20 . The seat 19 is restrained against turning relative to the housing by the spring 15 . This may be achieved by friction between the spring and the seat. Additionally, there may be formed on the seat 19 an axially projecting lug which cooperates with the spring to prevent turning of the seat relative to the spring. Accordingly, by turning of the carrier 20 relative to the housing 10 , the seat 19 can be screwed along the housing to increase or decrease the stress in the spring 15 .
The carrier 20 is integral with a fixed hollow piston 22 which slides inside the cylinder 16 . The piston has an annular seal for bearing on the wall of the cylinder to establish an oil-tight relation between the piston and the cylinder. The piston 22 serves to guide the adjacent end portion of the cylinder 16 for movement relative to the housing along the main axis 17 .
Further guide means is provided for guiding the head 18 for movement along the main axis 17 relative to the housing 10 . The further guide means is represented in FIG. 3 and comprises a pair of outer guide elements 23 and 24 incorporated in the housing 10 and a pair of inner guide elements 25 and 26 incorporated in the head 18 of the cylinder. The inner guide elements are formed as rollers and are mounted for free rotation relative to the head 18 about respective axes 27 and 28 which lie on opposite sides of the main axis 17 , are equally spaced from that axis and are perpendicular to that axis. The roller axes 27 and 28 are parallel to the axis 11 . The outer guide elements 23 and 24 have respective flat, mutually parallel faces on which the rollers 25 and 26 run.
A first cam 29 lies inside the housing 10 , adjacent to the cylinder head 18 , and is fixed with respect to the rotary operating member 12 . The cylinder 16 is provided with a cam follower for cooperating with the cam 29 . In the example illustrated, the cam follower is a roller 30 which engages the periphery of the cam 29 . For transmitting force between the head 18 of the cylinder and the roller 30 , there is provided a pair of rollers 31 and 32 mounted for free rotation relative to the head 18 about the axes 27 and 28 . Thus, the axes of the rollers 31 and 32 are fixed with respect to the cylinder 16 . The roller 30 is, however, free to undergo limited movement relative to the cylinder, although the roller 30 is trapped in the head 18 .
The cylinder 16 is urged towards the axis 11 by the main spring 15 . Accordingly, the rollers 31 and 32 are held in firm engagement with the cam follower roller 30 and the latter roller is held in firm engagement with the first cam 29 . This relationship is achieved, irrespective of manufacturing tolerances and irrespective of normal wear of components which may occur during the service life of the device.
A second cam 33 , only shown in FIG. 1 , which is identical with the cam 29 , is mounted in fixed relation to, but spaced along the axis 11 from, the first cam 29 . The cylinder head 16 is provided with a further pair of rollers corresponding to the rollers 31 and 32 and mounted for rotation relative to the head about the axes 27 and 28 and with a further floating roller 36 corresponding to the floating roller 30 , the roller 36 cooperating with the second cam and with the further pair of rollers in the same manner as that which the floating roller 30 cooperates with the first cam and with the rollers 31 and 32 .
A first movable piston 37 is mounted inside the cylinder 16 for reciprocation relative thereto. The piston 37 comprises a head 38 bearing a spherical seat which cooperates with the wall of the cylinder and a piston rod 39 extending from the head 38 in a direction towards the axis 11 . The piston rod 39 passes between the guide rollers 25 and 26 and is thereby guided for movement along the main axis 17 . At its end remote from the head 38 , the piston rod 39 carries a cam follower in the form of a roller 40 . The roller 40 bears on the periphery of a third cam 41 interposed between the cams 29 and 33 and fixed with respect thereto.
A second possible piston 43 is also mounted in the cylinder 16 for reciprocator relative thereto. The second piston comprises a head 44 bearing a peripheral seal which cooperates with the wall of the cylinder and a piston rod 45 which extends from the head 44 in a direction towards the piston 37 and the axis 11 . A coiled compression spring 46 , which lies mainly inside the hollow piston 22 and which protrudes therefrom to the head 44 of the piston 43 urges the piston 43 towards the piston 37 and thereby urges the piston 37 towards the axis 11 . This maintains the roller 40 in engagement with the periphery of the cam 41 .
The cylinder 16 contains an annular plug 47 which lies between the piston head 38 and the piston head 44 . This plug is fixed with respect to the cylinder and is sealed to the cylinder. For convenience of manufacture and assembly of components of the device, the cylinder may be formed in two parts, which meet at the plug 47 . The plug may be employed to connect these parts of the cylinder together. The piston rod 45 extends through the plug 47 and is sealed with respect thereto by an annular seal mounted in the plug. The plug divides a first chamber 48 in the cylinder 16 , lying between the piston head 38 and the plug, from a second chamber 49 lying between the plug and the piston head 44 . A third chamber 50 inside the cylinder extends from the piston head 44 to the fixed piston 22 and includes the interior of that piston. Passages are provided for the flow of oil between these chambers and the space 51 outside the cylinder 16 which contains the main spring 15 .
A passage providing communication between the third chamber 50 and the space 51 contains an adjustable needle valve 52 . The needle valve is screwed into a threaded bore formed in the carrier 20 and a portion of the valve protrudes at the outside of the carrier 20 , so that a tool can be applies to the needle valve to adjust the degree of construction of the flow path past the needle valve. The needle valve extends into an annular restrictor disposed in the central bore of the carrier 20 . Lateral ports extend from this central bore to the space 51 at a position between the restrictor and the adjacent end of the housing 10 .
A port 53 is formed in the cylinder 16 at a position between the plug 47 and the piston head 44 . This port provides for relatively free flow of oil between the space 51 and the second chamber 49 . A filter may be provided in the port 53 to prevent solid matter entering the cylinder. Communication between the second chamber 49 and the third chamber 50 is provided by a passage 54 formed in the piston head 44 . This passage contains a non-return valve which permits flow in a direction from the second chamber to the third chamber but prevents flow through the passage 54 from the third chamber to the second chamber.
The third chamber 50 is in communication with the first chamber 48 via passages formed in the piston head 44 and the piston rod 45 , which is hollow along its entire length. A recess is formed in that face of the piston head 38 which abuts the piston rod 45 , to ensure free flow between the interior of the piston rod 45 and the first chamber 48 .
Referring now particularly to FIGS. 5 to 7 . On the opposite side of the axis 11 to the cylinder 16 and the head 18 is provided a back check device indicated generally at 110 . The device 110 comprises a pair of spherical intermediate piston members 111 which are received in plastic piston members 112 which, when engaged by the spherical members 111 , are placed in a sealing engagement with the wall of a cylindrical cylinder 113 provided by a cross bore in the housing 10 . The cross bore 113 is closed at opposite ends by threaded plugs 114 and a pair of coiled compression springs 115 are engaged between each plug 114 and the associated piston 112 .
A cam follower 116 is received in a slot 117 formed in the housing 10 access being gained for machining purposes by an opening 118 which is closed after assembly of the device by a cylindrical plug 119 . The cam follower 116 is controlled for movement in a plane containing the axis of the spherical members 111 and the cam 41 by engagement therewith whilst movement in a direction at right angles to the plane is effected by engagement of the cam follower 116 with upper and lower surfaces of the slot 117 .
The piston members 112 engage in the cylinder 113 to form variable volume chambers 120 , 121 . Referring now to FIG. 8 , the chamber 120 is connected by a passage 123 to the chamber 121 . This chamber is connected by a passage 124 to a manually adjustable metering valve 125 which is connected by a passage 126 to the interior 127 of the housing 10 . The valve 125 is accessible via a passage 125 a in the housing to permit the user adjustment of the rate of flow of fluid therethrough. If desired, alternatively, the valve may have its rate of flow pre-set on assembly. In this case the passage 125 a is not required. In addition the passage 124 is connected by a passage 128 to a non-return valve 129 which is in communication with the interior 127 of the housing.
FIG. 2 illustrates the positions of the first cam 29 , cylinder 16 and the pistons 22 , 37 and 43 , when the rotary member 12 is in a rest position relative to the housing 10 . This is the position occupied when the main spring 15 is extended. It corresponds to the closed position of a door connected with the rotary member 12 . FIG. 3 illustrates the position of the cam 41 , guide rollers 25 and 26 , the cylinder and the pistons also when the rotary member 12 is in the rest position. When the operating member is turned from the rest position, the cam 29 drives the floating roller 30 away from the axis 11 , a small, initial, angular movement of the cam causing a relatively large displacement of the roller. Since the rollers 31 and 32 are held in firm engagement with the floating roller 30 and have respective axes which are fixed with respect to the cylinder 16 , the cylinder is caused to move away from the axis 11 with the floating roller 30 . Turning of the cam from the rest position drives the cylinder 16 away from the axis 11 and allows the piston 37 to move towards that axis. Movement of the cylinder away from the axis 11 compresses the main spring 15 .
When the associated door is released, the spring 15 drives the cylinder 16 towards the axis 11 . The cam and follower mechanism transmits motion from the cylinder 16 to the operating member 12 so that the door is swung towards the rest position. Turning of the operating member towards the rest position is yieldably opposed by the damping action of the device.
As the cam 41 is turned towards the rest position, it drives the roller 40 away from the axis 11 . The piston head 38 is moved towards the plug 47 so that the volume of the first chamber 48 is reduced. Oil is expelled from that chamber along the interior of the hollow piston rod 45 to the third chamber 50 . The piston 43 also is moved away from the axis 11 towards the fixed piston 22 so that the volume of the third chamber 50 also is reduced. Flow of oil from the third chamber to the second chamber 49 is prevented by the non-return valve in the passage 54 . Accordingly, all of the oil expelled from the first chamber 48 and from the third chamber 50 must flow through the orifice restricted by the needle valve 52 . Closing movement of the door is thereby controlled.
The shape of the cam 29 is selected to provide that the action of the floating roller 30 on the cam, when the operating member 12 is in the rest position, is a strong centering action, driving the came to and holding the cam in the rest position. The orientation of the cam relative to the housing 10 , when in the rest position, can be adjusted through a small range by adjusting the outer guide elements 23 and 24 in a direction transverse to the axis 11 . Adjustment of these guide elements 24 and 25 may be provided as described in GB-B-2261915.
Referring now particularly to FIGS. 5 to 7 , when the door is first opened through a small angle, for example 15° as illustrated in FIG. 5 , the cam follower 116 is not engaged by the cam 41 and so no movement of the spherical members 111 occurs and therefore there is no change in volume of the chambers 120 , 121 and therefore no restriction on opening of the door. When the door is moved through 90° the cam follower 116 comes into engagement with the cam 41 initially; movement of the door beyond 90° causes relatively large movement of the cam follower 116 and hence large movement of the spherical members 111 along the cylinder 113 . However as the door approaches the 180° position then, as best shown in FIG. 7 , the cam follower 116 is progressively moved to the left in FIGS. 4 to 6 with consequent movement of the spherical members 111 along the cylinders 113 and consequential restriction in size of the chambers 120 , 121 . Fluid from these chambers is forced along the passages 123 , 124 to the metering valve 125 which restricts the rate at which fluid can be discharged from the chambers 120 , 121 , therefore restricting the rate of movement of the spherical members 111 and so restricting the rate of movement of the cam follower 116 which has the effect of raising the torque required to open the door, thereby providing a back check effect which reduces in value as the door approaches 180° of movement.
When it is desired to close the door then normally it is simply released so that the door is returned to its initial position by the spring 15 as hereinbefore described. Such movement is permitted by oil being drawn into the chambers 120 , 121 through the passage 128 via the valve 129 .
Accordingly, the present invention provides a means of controlling the opening movement of a door beyond a predetermined angle, for example 90° to prevent damage to walls and furniture as a result of such opening movement being existent.
By providing the two separate piston and cylinder arrangements acting upon the cam following 116 a relatively great back check action can be provided without increasing the size of the housing beyond that necessary to achieve a proper closing action as the back check load required is split between two separate piston and cylinder arrangements.
In the present specification “comprises” means “includes or consists of” and “comprising” means “including or consisting of”.
The features disclosed refer to a floor spring where space is restricted between the pivot point (axis 11 ) and the door frame. Typically, this distance is of the order of 70 mm. However, the features disclosed could equally apply to a surface mounted overhead closer if a compact back check system is required.
The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.
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A door closer comprising a housing, a member for driving engagement with a door, the member being rotatable relative to the housing in a door opening direction and in a door closing direction, a spring apparatus within the housing providing a resilient bias, the resilient bias being increased by rotation of the member in the door opening direction and a check device for controlling rotation of the member in the door closing direction and hence closure of the door under the action of the spring apparatus, the door closer having a back check comprising a piston member movable in a cylinder from an initial position against resistance of a fluid medium by rotation of the rotatable member in the opening direction.
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FIELD OF THE INVENTION
The present invention relates to prefabricated, multi-sided building and construction system. In particular it relates to a prefabricated gazebo and a construction system which utilizes lightweight framing components and a unique roof support and roof which results in the construction of the gazebo.
BACKGROUND OF THE INVENTION
Gazebos and other multi-sided buildings are well known in the prior art. Gazebos have historically been multi-sided buildings usually constructed in a park form wood or similar materials. Recently Gazebos have found popularity in areas of multi-family residences or in single family homes on larger pieces of land.
DESCRIPTION OF THE PRIOR ART
U.S. Pat. No. 4,173,855 discloses a prefabricated building or gazebo having an octagonal configuration. The structure includes a structural support system, a floor system carried by the support system above the level of the ground, and a roof system supported solely by the support system. The floor and roof systems are provided with collars, each with at least three sides, which are spaced apart and are located on the central vertical axis of the structure. The structural support system includes at least three vertical support columns with each column being spaced an equal distance from the central axis of the structure and also equal distances form adjacent columns. The roof system includes rafters of equal length one for each side of the roof collar and corresponding support column. However, this structure does not offer an easily assembled gazebo constructed of light weight materials, such as plastic, which can be readily assembled by a single individual. It also does not offer a basic gazebo structure with different embodiments.
U.S. Pat. No. 3,908,329 discloses a polygonal building which has a perimeter wall made from a plurality of initially roughly plumbed rectangular wall sections arranged in end-to-end but spaced apart relation to each other. Roof rafter extend from a common point, approximately centrally of the building, down to and between the upper ends of adjacent wall sections. A perimeter cable is threaded through the all of the wall sections and the roof rafters. Tightening of the cable plumbs the wall sections and centers the roof rafters.
U.S. Pat. No. 6,349,511 discloses a gazebo which is fabricated from lightweight aluminum framing components. The preferred structure has eight sides. Each side includes a pair of vertical posts, a pair of header members, a rail and foot member, columns disposed between the rail and foot member and the pair of header members, and an insulated composite roof panel. As each side unit is attached by self mating beam and vertical post members to an adjacent side unit, the gazebo structure is formed. The gazebo can be provided with screening on the vertical posts and shingles on the roof.
SUMMARY OF THE INVENTION
The present invention includes a system or kit of injection molded panels and other components having integrated connectors which combine together to form an enclosure, preferably in the form of a gazebo. The support posts, roof rafters, roof supports, roof panels and walls are formed of injection molded plastic to interlock with one another without the need for separate I-beam connectors. The system incorporates a minimum number of components to construct a gazebo type enclosure by integrally forming connectors in to the injection molded components and panels. This minimizes the need for separate extruded or molded connectors to assemble the enclosure. The symmetry of the support posts, roof rafters, roof supports, roof panels and other components also minimizes the shapes of the components and simplifies construction of the gazebo. The heavy duty interlocking construction of the support posts, roof rafters, roof supports, roof panels and other components create a structural frame which permits construction of larger gazebos. Injection molding of the support posts allows them to be formed to a sufficient length to provide a gazebo with adequate height for all intended purposes, including the provision of overhead fans. This eliminates the need for a plurality of support posts to be stacked one above the other to achieve the heights desired. Injection molding also allows the roof panels to be formed with integral cross-bracing, ribs and gussets for increased rigidity when compared to blow molded or extruded panels.
In one embodiment, the gazebo system or kit utilizes interlocking support posts, roof rafters and roof supports to create a structural frame. Three types of support structure construction are integrated into the structural frame. The first is utilized for the support posts, the second is utilized for the roof rafters and the third is utilized for the roof supports. The support posts are constructed to cooperate, via integrally formed connectors, with the roof rafters and other members that permit the support posts to be secured to a base or other means to secure the support posts to the ground. The roof rafters are constructed to cooperate, via integrally formed connectors, with the roof supports to form a support structure which will support the roof panels. The roof supports also include integrally formed connectors which permit the roof supports to cooperate with the roof rafters to form a support structure which will support the roof panels. The structural frame may include provisions for standard electrical current hookups. The roof support may also include connectors to permit the use of additional components such as fans or lighting components.
Accordingly, it is an objective of the instant invention to provide a system or kit which utilizes plastic frame and panel members having integral connectors to create a gazebo type structure or enclosure of varying dimensions using common components.
It is a further objective of the instant invention to provide a system or kit wherein the structural components include integrated connectors which accommodate injection molding plastic formation of the components for increased structural integrity.
It is yet another objective of the instant invention system or kit which utilizes roof rafters and roof supports having interlocking bosses and apertures to increase rigidity and prevent bowing of the rafters and supports.
It is a still further objective of the invention to provide structural roof panel members including integrated connectors, cross-bracing and gussets to increase rigidity and prevent bowing of the roof panels.
It is still yet another objective of the instant invention to provide a system or kit which reduces the number of components required to assemble a gazebo and simplifies construction of a gazebo.
Other objects and advantages of this invention will become apparent from the following description taken in conjunction with any accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention. Any drawings contained herein constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a perspective view of a preferred embodiment of the gazebo of the present invention;
FIG. 2A is a view of a base onto which the gazebo is secured using a plurality of support posts;
FIG. 2B is a detailed view of the attachment of the support posts to the base;
FIG. 3A is another view of a base and support posts similar to FIG. 2A ;
FIG. 3B is a detailed view of the attachment of the support posts to the base similar to FIG. 2B ;
FIG. 4A is a perspective view of a roof support member;
FIG. 4B is a detailed view of the attachment of an outer roof support the roof rafters;
FIG. 5 is a view of a lower roof rafter and a socket secured to an end;
FIG. 6 is a view of the ramp lock connection between the sockets and the roof rafters;
FIG. 7A is a view of the attachment of the roof support members to the support posts;
FIG. 7B is a detailed view of the arrangement of the upper receptacles;
FIG. 7C is a detailed view of the attachment of a roof rafter to a support post;
FIG. 8A is a view of all of the roof support members secured together;
FIG. 8B is a detailed view of a fascia board secured to an upper roof rafter;
FIG. 9A is a view of the attachment of an upper roof panel to the upper roof rafters;
FIG. 9B is a detailed view of the attachment of an upper roof panel to an upper roof rafter;
FIG. 10A is a view of all of the upper roof panels secured to the upper roof rafters;
FIG. 10B is a detailed view of an end cap on an upper roof rafter;
FIG. 11A is a view of an upper roof railing;
FIG. 11B is a detailed view of an upper roof railing and an upper roof panel;
FIG. 12A is a view of a fascia board secured to a lower roof rafter;
FIG. 12B is a detailed view of a fascia board secured to a lower roof rafter;
FIG. 13A is a view of the attachment of a lower roof panel to the lower roof rafters;
FIG. 13B is a detailed view of the attachment of a lower roof panel to a lower roof rafter;
FIG. 14A is a view of all of the lower roof panels secured to the lower roof rafters;
FIG. 14B is a detailed view of an end cap on a lower roof rafter;
FIG. 15A is a view of a lower roof railing;
FIG. 15B is a detailed view of a lower roof railing and a lower roof panel;
FIG. 16A is a view of hand rails secured to the support posts;
FIG. 16B is a detailed view of the attachment of the hand rails to the support posts;
FIG. 17A is an exploded view of an upper roof panel;
FIG. 17B is a detailed view of the attachment of the upper and lower portions of an upper roof panel;
FIG. 18A is an exploded view of an upper roof panel;
FIG. 18B is a detailed view of the attachment of the upper and lower portions of an upper roof panel;
FIG. 19A is an exploded view of an upper roof panel;
FIG. 19B is a detailed view of the attachment of the upper and lower portions of an upper roof panel;
FIG. 20A is an exploded view of a lower roof panel;
FIG. 20B is a detailed view of the attachment of the upper and lower portions of a lower roof panel;
FIG. 21A is an exploded view of a lower roof panel;
FIG. 21B is a detailed view of the attachment of the upper and lower portions of a lower roof panel;
FIG. 22A is an exploded view of a lower roof panel;
FIG. 22B is a detailed view of the attachment of the upper and lower portions of a lower roof panel;
FIG. 23 is a perspective of an optional provision for attaching a fan to the interior of the gazebo of the present invention;
FIG. 24 is another embodiment of the gazebo of the present invention;
FIG. 25 is another embodiment of the gazebo of the present invention; and
FIG. 26 is another embodiment of the gazebo of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
While the present invention is susceptible of embodiment in various forms, there is shown in the drawings and will hereinafter be described a presently preferred, albeit not limiting, embodiment with the understanding that the present disclosure is to be considered an exemplification of the present invention and is not intended to limit the invention to the specific embodiments illustrated.
FIG. 1 illustrates a perspective view of a gazebo type structure, generally referenced as 10 , constructed in accordance with a preferred embodiment of the present invention. In the preferred embodiment, the components of the gazebo, including the roof, are formed of not limited to a suitable plastic such as polystyrene, polypropylene or polyethylene, through the process of injection molding. The gazebo is set upon a base or platform 12 . The base or platform may be included as an element of the gazebo, but preferably it is not. The base can be formed as a poured concrete slab or platform, as a wooden deck, or as a plurality of interconnected components such as bricks or pavers. One of the requirements of the base or platform 12 is that it is capable of properly supporting and securing the support posts 14 and attached gazebo structure, including the roof assembly 22 . The base or platform must also be capable of providing proper support for individuals and other objects enclosed within the gazebo.
Referring to FIGS. 2A and 2B the support posts 14 are secured to the base 12 utilizing attachment posts 16 . These attachment posts are preferable made from steel. However, other materials could be used providing these materials permit the support posts 14 to be properly secured to base 12 . The base of the attachment posts are provided with apertures 18 , as shown in FIG. 2B . The attachment posts 16 are preferably secured to the base in the manner illustrated in FIG. 3B . A plurality of fasteners 20 are secured in base 12 . The posts are secured to the fasteners using nuts and washers. The fasteners 20 could be set into a poured concrete slab prior to its drying. They could also be set into holes drilled into a dried concrete slab and secured with expansion anchors. When a wooden deck is employed as the base, the fasteners can be bolts or screws. Depending on the type of base that is used, appropriate fasteners are utilized. FIG. 3A illustrates that a number of support posts, in this case 8 , are secured to base 12 . The support posts 14 are preferably secured in a circular pattern.
The support posts 14 are next secured to the attachment posts 16 by use of fasteners. Preferably a support post 14 is placed over an attachment post 16 and set onto base 12 . After the support post 14 is in place it is secured to the attachment post 16 with fasteners. The fasteners are inserted into apertures which are drilled into posts 14 and 16 .
A roof for the disclosed embodiment of the gazebo includes an upper roof and a lower roof. While a multi-layered is disclosed, a roof comprising a single layer is an alternative. The roof 22 comprises a plurality of roof support members and roof panels. These roof support members and roof panels are readily assembled from a plurality of various components as will be described hereinafter. FIGS. 4-6 illustrate an assembly of one of the roof support members 23 . A roof support member 23 is formed from roof rafters and roof supports. A lower roof rafter 24 is positioned below and aligned with an upper roof rafter 26 . Roof rafters 24 and 26 are secured together, at one end thereof, by an inner roof support or segment 28 . A segment, receptacle or socket 30 is attached to one end of rafter 24 , as illustrated in FIG. 5 . Receptacle 30 is provided with a connection member 32 along one side. The connection member 32 is formed with a ramp lock 34 on at least one surface thereof. The ramp lock 34 is positioned so that when the connection member is placed into the interior of roof rafter 24 , the ramp lock 34 will engage aperture 36 , located on a side of roof rafter 24 , for interlocking engagement therewith. The interlocking engagement between ramp lock 34 and aperture 36 secures connection member 32 of the receptacle 30 to the lower roof rafter 24 . The receptacle 30 further includes a socket 31 which is sized so that an end of inner roof support 28 will fit snugly therein. Another segment, receptacle or socket 38 is attached to one end of an upper roof rafter 26 , as illustrated in FIGS. 4 and 6 . Receptacle 38 is provided with a connection member 40 along one side thereof. The connection member 40 is formed with a ramp lock 42 on at least one surface thereof. The ramp lock 42 is positioned on the connection member so that when the connection member is placed in the interior of roof rafter 26 , the ramp lock 42 will engage aperture 44 , located on a side of upper roof rafter 26 , for interlocking engagement therewith. The interlocking engagement between ramp lock 42 and aperture 44 secures receptacle to the upper rafter 26 . The receptacle feather includes a socket 39 , opening toward the bottom of the socket. The socket 39 is sized so that an upper end of inner roof support 28 will fit snugly therein.
An outer roof support 46 is secured between and holds roof rafters 24 and 26 together, as illustrated in FIG. 4 . A lower end of outer roof support 46 is placed into the interior of lower roof rafter 24 through a slot on an upper edge of lower roof rafter 24 . The lower end of the outer roof support is preferably formed at an angle with respect to the edges of the outer roof support. This angle corresponds to the angle or pitch of the lower roof rafter 24 . After the support 46 has been inserted into lower roof rafter 24 it is secured therein with fasteners. An upper end of roof support 46 is placed into the interior of upper roof rafter 26 through a slot on a lower edge of upper roof rafter 26 . After the support 46 has been inserted into rafter 26 it is secured therein with fasteners. A plurality of roof support members 23 are secured together to form a center hub 48 , as illustrated in FIGS. 7A and 8A . The center hub 48 includes an upper section 50 , a middle section 52 and a lower section 54 . The upper section 50 comprises a plurality of receptacles 38 secured together as illustrated in FIG. 7A . The receptacles 38 are formed with complementary sides, as illustrated in FIG. 7B . These complementary sides enable the receptacles 38 to be secured together to form the upper section 50 of the central hub 48 . A cap 56 ( FIG. 8A ) secures a plurality of receptacles 38 together thereby form the upper section 50 . The middle section of the center hub comprises a plurality of inner roof supports 28 secured around a central point. The upper ends of the inner roof supports are positioned within receptacles 38 and the lower ends of the inner roof supports are positioned within receptacles 30 . The lower section of the center hub comprises a plurality of receptacles 30 secured together. The receptacles 30 are formed with complementary sides, similar to sides of receptacles 38 . These complementary sides enable the receptacles 30 to be secured together to form the lower section 54 of the central hub 48 . A cap 58 ( FIG. 7A ) is secured to the bottom portions of the receptacles 30 and provides assistance in holding the plurality of receptacles 30 together.
The outer portions of the lower roof rafters 24 are secured to the upper portions of support posts 14 in a manner illustrated in FIG. 7C . A slot is provided in the top of support post 14 and an end portion of a lower roof rafter 24 is placed into the slot. A plurality of fasteners 60 secure each of the support posts 14 to each roof rafter 24 . A plurality of roof rafter assemblies are attached to each of the support posts and secured together by caps 56 and 58 to form a support for the roofs ( FIG. 8A ). A wire 62 encircles the support posts 14 . It can be secured to an outer surface of support posts 14 or passed through a portion of the support posts 14 . The wire helps hold the upper portion of the gazebo together and oppose any radial outwardly forces
Referring to FIGS. 8A and 8B upper roof fascia boards 64 are secured between the outer ends of upper roof rafters 26 . The ends of the upper roof fascia boards are placed into slots 66 formed in an outer portion of the upper roof rafters 26 , FIG. 8B . In the embodiment illustrated there are 8 fascia boards. The upper fascia boards 64 can also be secured to the upper roof rafters 26 by fasteners, friction or other securing means. The upper roof fascia boards 64 provide stability to the upper roof rafters so that they will maintain a substantially fixed position relative to each other. This positioning of the upper roof rafters enables upper roof panels 68 to be secured between the upper roof rafters. The upper roof panels are provided with a flange 70 which extends along each longitudinal side. The flange 70 is designed to be placed into a slot 72 which extends longitudinally along both sides of an upper portion of upper roof rafter 26 , FIG. 9B . The upper roof panels are slid up along the upper roof rafters into their final position wherein the narrow portion of the upper roof panel is positioned below cap 56 . Once the roof panels are in their final position they are also secured to the upper roof fascia boards 64 by fasteners or other securing means. Trim elements 74 are secured over the top portion of each of the upper roof raters, as illustrated in FIG. 10A . A cap 76 is placed over each outer open end of each of the upper roof rafters 26 and secured in place as illustrated in FIG. 10B .
A wire or cable 67 extends through each of the support posts 14 and lower roof rafters 24 , as illustrated in FIGS. 8A and 9A . The wire or cable is substantially circular and one end of the wire or cable is secured to the other end of the wire or cable by a turnbuckle 69 or similar device ( FIG. 9A ). The wire or cable helps to secure and hold the supports posts and roof rafters together. Other means could be used in place of the wire or cable as long as it performed the same or similar function. The wire or cable could also extend through other elements of the gazebo as long as it performed the same or a similar function. The number of walls which the gazebo has determines the shape of the wire or cable.
Referring to FIGS. 11A and 11B upper roof railings 78 are secured in between the outer roof supports 46 . In the embodiment illustrated herein there are 8 upper roof railings. The number of upper roof railings preferably corresponds to the number of outer roof supports. As illustrated in FIGS. 4A and 11B each of the outer roof supports 46 has at least two apertures 80 . Preferably there are two apertures 80 on a first side of outer roof support 46 and two apertures on a side of outer roof support 46 opposite the first side. The ends 82 of the upper roof railings are placed into apertures 80 . The upper roof railings are held in place by the fact that the railings 78 are longer that the distance between the outer roof supports 46 . In addition the ends 82 of the upper roof railings can be secured to the outer roof supports 46 by fasteners, friction or other securing means. Preferably the shape of apertures 80 is the same or similar to the cross sectional shape of ends 82 .
Referring to FIGS. 12A and 12B lower roof fascia boards 84 are secured between the outer ends of lower roof rafters 24 . The ends of the lower roof fascia boards are placed into slots 88 formed in an outer portion of the lower roof rafters 24 , FIG. 12B . In the embodiment illustrated there are 8 fascia boards. The lower roof fascia boards 84 provide stability to the lower roof rafters so that they will maintain a substantially fixed position relative to each other. The lower fascia boards can also be secured to the lower roof rafters 24 by fasteners, friction or other securing means. This positioning of the lower roof rafters enables lower roof panels 90 to be secured between the lower roof rafters. The lower roof panels 90 are provided with a flange 92 ( FIG. 13B ) which extends along each longitudinal side of the lower roof panel. The flange 92 is designed to be placed into a slot 94 which extends longitudinally along both sides of an upper portion of lower roof rafter 24 , FIG. 13B . The lower roof panels 90 are slid up along the lower roof rafters into their final position wherein the narrow portion of the upper roof panel is positioned below the upper roof. Once the roof panels are in their final position they are also secured to the lower roof fascia boards 84 by fasteners or other securing means. Trim elements 96 are secured over the top portion of each of the lower roof raters, as illustrated in FIG. 14A . A cap 98 is placed over each outer open end of each of the lower roof rafters 24 and secured in place as illustrated in FIG. 14B .
Referring to FIGS. 15A and 15B lower roof railings 100 are secured in between the support posts 14 . In the embodiment illustrated there are 8 lower roof railings. As illustrated in FIG. 15A each of the support posts 14 has at least two apertures 102 in an upper portion. Preferably there are two apertures 102 on a first side of support post 14 and two apertures on a side of post 14 opposite the first side. The ends 104 of the lower roof railings are inserted into these apertures. The lower roof railings are held in place by the fact that the railings 100 are longer that the distance between the support posts 14 . In addition the ends 104 of the lower roof railings can be secured to the support posts 14 by fasteners, friction or other securing means. Preferably the shape of apertures 102 is the same or similar to the cross sectional shape of ends 104 .
Referring to FIGS. 16A and 16B hand rails 106 are placed in between support posts 14 at a lower portion of the support posts. Each of the support posts 14 has at least two apertures 108 in a lower portion of the post. Preferably there are two apertures 108 along a first side of support post 14 and two apertures 108 along another side of post 14 opposite the first side. The ends 110 of hand rails 106 are inserted into the apertures 108 thereby securing the hand rails to the support posts 14 . The hand railings are held in place by the fact that the railings 106 are longer that the distance between the support posts 14 . Preferably the shape of the apertures 108 is the same or similar to the cross sectional shape of the ends 110 of the hand rails. In addition, other means such as fasteners can be employed to secure the handrails to support posts 14 . In the embodiment illustrated there are 7 hand rails, see FIG. 1 . A hand rail is not secured between support posts 14 wherever an entrance/exit is desired for access to the interior of the gazebo. Although one entrance/exit is shown, there can be a plurality of entrances/exits.
Referring to FIGS. 17A-19B the upper roof of the gazebo comprises a plurality of upper roof panels 112 . In the embodiment illustrated herein there are 8 upper roof panels. Usually the number of upper roof panels corresponds to the number of sides of the gazebo. However, there could be any number of upper roof panels. In the illustrated embodiment there are 8 sides and 8 upper roof panels. Each of the upper roof panels 112 comprises an upper portion 114 and a lower portion 116 . Each upper and lower portion includes a top member and a bottom member. The top member 118 of the upper portion 114 is illustrated in FIGS. 17A , 18 A and 19 A. The bottom member 120 of the upper portion 114 is illustrated in FIG. 19A . The bottom member 122 of the lower portion 116 is illustrated in FIGS. 17A , 18 A and 19 A. The top member of the lower portion is not illustrated. The top members of the upper and lower portions of the roof panels have a plurality of roof shingles molded therein. The underside of the top member 120 of the upper portion is illustrated in FIGS. 17A , 18 A and 19 A. As can be seen in these Figs. a plurality of roof shingles are molded into the member.
The upper portion 114 of the roof panel 112 is connected to the lower portion 116 of the roof panel utilizing projections 124 formed or molded onto the upper portions of the roof panel. These projections cooperate with apertures 126 and slots 128 formed on the lower portion 116 of the roof panel. In order to connect the upper and lower portions of the roof panels together the projections 124 are placed into slots 126 , as illustrated in FIG. 17B . Upper portion 114 is then slid toward the right ( FIGS. 17B and 18B ) so that projection 124 engages slot 128 to secure the upper and lower portions 114 and 116 together. Of course the locations of the projections, apertures and slots could be reversed so the projections 124 were on the lower portion 116 and the apertures 126 and slots 128 were on the upper portion 114 .
Referring to FIGS. 20A-22B the lower roof of the gazebo comprises a plurality of lower roof panels 90 . In the embodiment illustrated herein there are 8 lower roof panels. Usually the number of lower roof panels corresponds to the number of sides of the gazebo. However, there could be any number of lower roof panels. In the illustrated embodiment there are 8 sides and 8 lower roof panels. Each of the lower roof panels 90 comprises an upper portion 130 and a lower portion 132 . Each upper and lower portion includes a top member and a bottom member. The top member 134 of the upper portion 130 is illustrated in FIGS. 20A , 21 A and 22 A. The bottom member 136 of the upper portion 130 is illustrated in FIG. 22A . The bottom member 138 of the lower portion 132 is illustrated in FIGS. 20A , 21 A and 22 A. The top member of the lower portion is not illustrated. The top members of the upper and lower portions of the roof panels have a plurality of roof shingles molded therein. The underside of the top member 134 of the upper portion is illustrated in FIGS. 20A , 21 A and 22 A. As can be seen in these figures a plurality of roof shingles are molded into the member 134 .
The upper portion 130 of the roof panel 90 is connected to the lower portion 132 of the roof panel utilizing projections 140 formed or molded onto the upper portions of the roof panel. These projections cooperate with apertures 142 and slots 144 formed on the lower portion 132 of the roof panel. In order to connect the upper and lower portions of the roof panels together the projections 140 are placed into slots 144 , as illustrated in FIG. 21B . Upper portion 130 is then slid toward the right ( FIGS. 20B and 21B ) so that projection 140 engages slot 144 to secure the upper and lower portions 130 and 132 together. Of course the locations of the projections, apertures and slots could be reversed so the projections 140 were on the lower portion 132 and the apertures 142 and slots 144 were on the upper portion 130 .
A fan can optionally be installed in the gazebo 10 . The fan, not shown could be secured to a box 146 constructed and arranged to support the fan and provide electrical power to the fan, as illustrated in FIG. 23 . Box 146 is secure to cap 58 which in turn is secured to the bottom portions of receptacles 30 and holds the receptacles 30 together, as illustrated in FIG. 7A . Another box 148 is secured to another cap 56 . Cap 56 secures a plurality of receptacles 38 together, as illustrated in FIG. 8A . A rod or similar member 150 is secured to box 146 and box 148 . This provides and optional structure to help secure the upper, middle and lower sections of the center hub together. Electrical power is supplied to the fan by wires or other electrical transmitting devices which are connected to a source of electrical power. The wires are next run to an up the support posts 14 , through the lower roof rafters 24 and into the electrical box 146 . Other paths for the electrical wires are also possible. The different paths would be determined by the structure of the gazebo, the needs of the builder, aesthetic appearances, building codes, etc.
Another embodiment of the gazebo is illustrated in FIG. 24 . In this embodiment the gazebo has a single roof in place of the upper and lower roofs.
A further embodiment of the gazebo is illustrated in FIG. 25 . In this embodiment the side portions of the gazebo include partial side walls 152 , screens 154 and a door 156 .
A still further embodiment of the gazebo is illustrated in FIG. 26 . In this embodiment solid molded panels or a plastic sheet 158 can be placed over the screens 154 to enable the gazebo to be utilized in the winter and to protect items within the gazebo from the elements of the weather.
All patents and publications mentioned in this specification are indicative of the levels of those skilled in the art to which the invention pertains. All patents and publications are herein incorporated by reference to the same extent as if each individual publication was specifically and individually indicated to be incorporated by reference.
It is to be understood that while a certain form of the invention is illustrated, it is not to be limited to the specific form or arrangement herein described and shown. It will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not to be considered limited to what is shown and described in the specification and any drawings/figures included herein.
One skilled in the art will readily appreciate that the present invention is well adapted to carry out the objectives and obtain the ends and advantages mentioned, as well as those inherent therein. The embodiments, methods, procedures and techniques described herein are presently representative of the preferred embodiments, are intended to be exemplary and are not intended as limitations on the scope. Changes therein and other uses will occur to those skilled in the art which are encompassed within the spirit of the invention and are defined by the scope of the appended claims. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention which are obvious to those skilled in the art are intended to be within the scope of the following claims.
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The present invention includes a system or kit of injection molded panels and other components having integrated connectors which combine together to form an enclosure, preferably in the form of a gazebo. The support posts, roof rafters, roof supports, roof panels and walls are formed of injection molded plastic to interlock with one another without the need for separate I-beam connectors. The system incorporates a minimum number of components to construct a gazebo type enclosure by integrally forming connectors in to the injection molded components and panels. This minimizes the need for separate extruded or molded connectors to assemble the enclosure. The symmetry of the support posts, roof rafters, roof supports, roof panels and other components also minimizes the shapes of the components and simplifies construction of the gazebo.
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BACKGROUND OF THE INVENTION
The present invention concerns structures for axially bearing and locating the drive shaft of a magnetic-tape cassette recording and/or reproducing apparatus, when the latter is of the type in which the drive shaft extends horizontally and the cassette loading platform is oriented vertically so that an inserted cassette stands in an upright position in the apparatus.
With cassette machines of this type, a very important problem is to completely eliminate all axial play in the mounting of the drive shaft of the apparatus, i.e., the shaft carrying or serving as the capstan. Specifically, if during cassette machine operation the horizontally extending drive shaft shifts axially in either a regular or irregular fashion, corresponding fluctuations develop in the velocity with which the magnetic tape sweeps across the record and/or playback head of the machine, resulting in acoustic wow and/or flutter.
This is inherently a more serious problem in cassette machines with horizontally extending drive shafts, compared to those designed with upright drive shafts, because in the latter case the weight of the drive shaft itself and of its mounting structure contributes significantly to the axial stabilization of the location of the drive shaft.
In vertical-drive-shaft cassette machines of the front-loading type, the magnetic-tape cassette is pushed, in a direction parallel to the rotation axis of the drive shaft of the machine, onto the rotary spool-rotating pegs of the machine and, as this is done, the magnetic tape extending between the two spools of the cassette comes into engagement with the capstan part of the machine's drive shaft. In the past with this particular type of cassette machine, the bearing located at the same side as the drive pin of the machine is designed as an axial bearing applying axial-shift resisting force to the drive shaft from only one side thereof, inter alia by applying a spring biasing force against the peripheral surface of the bushing of the drive shaft, to eliminate axial shifting of the drive shaft in this manner.
That kind of axial bearing is, however, quite expensive to produce if the requisite degree of resistance to axial shifting of the drive shaft is really to be established by application of force to the drive shaft from one side. Furthermore, precisely because of the particular technique employed, the drive shaft must now turn against the circumferential component of this biasing force, i.e., against elevated frictional resistance. However, it is of course generally desirable not to work against unnecessarily high frictional resistance, and this is indeed quite important, for example, in the case of battery-powered cassette machines.
SUMMARY OF THE INVENTION
Accordingly, it is the general object of the invention to provide a cassette machine with means which axially bear against and locate the horizontally extending drive shaft in a simple way, and furthermore in a way which does not inherently increase power consumption in the sense of the prior-art technique described above.
According to one concept of the invention, this can be achieved by employing an axial bearing and locating system which comprises a first axial bearing located on a stationary part of the cassette-machine housing and bearing against a first axial end of the drive shaft, and a second axial bearing which is located on the movable cassette loading platform of the machine and bears against the other axial end of the drive shaft.
Using this inventive technique, it furthermore becomes possible to use a point-contact bearing not merely at the axial end of the drive shaft which is remote from the cassette, but also at the axial end at the cassette. This is truly optimum with respect to minimizing frictional forces against which the machine's motor must work and, as will become clearer below, can make possible various extremely simple and convenient spatial relationships for the location and mounting of the motor or its drive shaft.
According to a very advantageous feature of the invention, the second axial bearing, i.e., the one provided on the movable cassette loading platform of the machine, comprises an elastically resilient biasing element serving to press the bearing element proper against the second axial end face of the drive shaft.
In this way, it becomes quite simple to inherently compensate for variations or tolerance in the exact location of the movable loading platform in successive cassette machines of a production run. Likewise, the precision of the means used to movably mount the loading platform or, equivalently, the precision of the path of loading-platform movement, does not become more critical or problematic when the inventive axial bearing and locating technique is employed.
According to a further advantageous concept of the invention, the axial bearing element proper of the second axial bearing, i.e., the one on the loading platform, is a hemispherical element. Alternatively, the axial end face of the drive shaft against which the second axial bearing bears can be hemispherical. This greatly minimizes unnecessary frictional loading. Furthermore, if the axial bearing element on the loading platform is hemispherical and presses against a flat axial end face of the drive shaft, this avoids the development of radial forces even if the exact location and orientation of the second axial bearing is not predetermined with extreme precision; this is explained in greater detail further below.
In order to avoid the use of a second axial bearing, e.g., the hemispherical bearing referred to above, the invention contemplates providing a single axial bearing which of itself resists axial shifting of the horizontal drive shaft in only one axial direction. However, a magnetic structure is then provided to apply a magnetic pulling force which pulls the drive shaft against the axial bearing, i.e., so as to prevent the drive shaft from moving relative to the axial bearing in the second axial direction.
The advantage of this latter technique is that only a single axial bearing need be employed to establish, quite simply and with a high degree of precision, bi-directional axial locating of the horizontal drive shaft. Indeed, because the single axial bearing can be located remote from the axial end of the drive shaft near the cassette, the drive shaft end near the cassette can be kept uncluttered by axial bearing structure.
A particularly preferred embodiment of the principle just described results when the magnetic pulling force is established by a closed magnetic system, the latter comprising a permanent magnet secured to a stationary part of the cassette-machine housing and, to close off the magnetic system and provide a complete circuit for magnetic flux, an annular flux-conducting element rigidly connected to and rotating with the horizontally extending drive shaft.
This latter expedient makes it particularly simple to balance the drive shaft and thereby achieve the requisite uniform-speed operation; or otherwise stated, this latter expedient adds nothing to the problem of balancing the drive shaft.
In order not to interfere with uniform rotation of the drive shaft, it is advantageous to use for the aforementioned stationary permanent magnet two component magnets located exactly diametrally opposite to each other, relative to the rotation axis of the drive shaft. This prevents the development of radially oriented forces such as might tend to tilt the drive shaft.
According to one particular preferred concept of the present invention, the cassette-machine drive shaft is constituted by the rotor shaft of a collectorless D.C. motor provided with compensatory reluctance-torque generating structure, such as disclosed in commonly owned U.S. Pat. No. 3,840,761, the disclosure of which is incorporated herein by reference. In that event, the magnetic circuit used in accordance with the present invention for axially locating the drive shaft additionally, and in certain applications very advantageously, acts as an eddy-current brake. As explained in commonly owned application Ser. No. 910,005 filed May 26, 1978, the magnitude of the reluctance torque produced can be adjusted by the manufacturer of the motor by adjusting the depth to which the rotor penetrates into the stator; because of this, and due to the high additive component of the total motor torque represented by the eddy-current brake, the amount by which the magnitude of the total motor torque can be changed by changing the depth of rotor penetration into the stator field is quite small, likewise making for very small manufacturing tolerances.
Accordingly, it is also of advantage to locate the axial-position-maintaining magnetic circuit radially remote from the drive shaft, because in that way the eddy-current component can be kept high, i.e., when this is desired.
In contrast, if this is not desired, e.g., because the drive shaft is to be of overhung design, or because energy consumption is to be minimized as in the case of a battery-powered cassette machine, then it is advantageous to keep the eddy-current component low by locating the axial-position-maintaining magnetic circuit radially close to the drive shaft. In that event, care must be taken to assure that the drive shaft does not itself become magnetized in a sense that might effect the magnetization of the cassette tape; however, with the materials conventionally employed, this is not actually any great problem.
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 specific embodiments when read in connection with the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 depicts a first exemplary embodiment of the invention;
FIG. 1a is a larger-scale depiction of the left axial bearing in FIG. 1, during operation;
FIG. 1b depicts a reversal of the relationships shown in FIG. 1a;
FIG. 2 depicts a secondary exemplary embodiment;
FIG. 3 depicts a third exemplary embodiment; and
FIG. 4 depicts a fourth exemplary embodiment of the indirect-drive type.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 schematically depicts a magnetic-tape cassette machine of the type in which the tape cassette is upright and the tape drive shaft is horizontal during use of the machine. Numeral 1 denotes the drive motor of the machine, e.g., a speed-regulated D.C. motor, provided with an axially extending drive shaft 10. Numeral 2 denotes a tape cassette inserted into the guide chute 3 of the movable loading platform 4. Numeral 5 denotes the housing of the cassette machine, and numeral 6 one of the two rotary spool-rotating pins of the cassette machine. The loading platform 4 is shiftably mounted on bearings 41, 42 located on stationary parts of the machine housing 5, i.e., so that after a cassette 3 has been dropped into guide chute 3 with loading platform 4 in the illustrated inoperative position, platform 4 can be pushed rightwards into operative position, in which the spool-rotating pegs 6 enter into the spools of the cassette and the drive shaft 10 engages and can drive the cassette tape.
In this embodiment, the cassette machine is of the direct-drive type and the drive shaft 10 is constituted by the rotor shaft of drive motor 1. The right axial end of shaft 10 is limited by a first axial bearing 11, provided on a stationary part of the machine housing 5. For example, the right end face of drive shaft 10 may be hemispherical, with the bearing element 11 constituted by a flat plate of hard metal against which the hemispherical end face rests in substantially point-contact.
The left axial bearing for the horizontal drive shaft 10 is provided on the loading platform 4 and comprises a spring 43 having a lower end secured to platform 4 and having a free end which carries the bearing element 44 proper. Spring 43 can be a metal leaf spring, or be made of strong but resilient rubber, or the like. The bearing element 44 is preferably hemispherical as shown. When the loading platform 4 is pushed in rightwards into operative position, hemispherical bearing element 44 presses against the flat left axial end face 110 of the drive shaft 10, being pressed rather firmly thereagainst by the spring 43. This way, during operation of the cassette machine, the axial position of the horizontally extending drive shaft 10 is completely predetermined and extremely constant.
FIG. 1a depicts on a larger scale the axial bearing at the left end of drive shaft 10 during machine operation. In principle, the hemispherical surface of bearing element 44 contacts the flat axial end face 110 of drive shaft 10 at only a single point. Accordingly, if the direction in which spring 43 urges bearing element 44 towards end face 110 is not perfectly axial, or is somewhat unpredetermined due to unavoidable tolerance variations in production, it is nevertheless the case that the hemispherical bearing element 44 can transmit only purely axial force to end face 110, and cannot transmit radial force.
In FIG. 1b, the situation is reversed relative to FIG. 1a; the left axial end face 110a of drive shaft 10 is hemispherical, and the axial bearing element 44a proper is flat. Here, in contrast, the bearing element 44a can transmit to drive shaft end face 110a a force which includes a radial component, if urged by spring 43 against end face 110a in a direction which is not perfectly axial. Accordingly, the expedient depicted in FIG. 1a is presently preferred.
It is advantageous to use for the elastic spring 43 a leaf spring, because this has been found to reduce the tendency of drive shaft 10 to oscillate. To this end, it has been found that the axial force pressing against the end face of drive shaft 10 should be equal to at least approximately 0.4 kiloponds.
FIG. 2 depicts an embodiment in which only a single axial bearing need be employed. Numeral 115 denotes the housing of the cassette machine. The drive motor employed is of the external-rotor type and comprises an internal stator 15 secured to the machine housing 115 and an external rotor 14 surrounding the stator. The rotor shaft 13 constitutes the tape drive shaft for direct-drive in this embodiment. Drive shaft 13 extends leftwards through a radial bearing 12 secured in a bore in housing 115. Just rightwards of the right end face 20 of the radial bearing 12, drive shaft 13 is provided with an annular shoulder 30. End face 20 and shoulder 30 together limit the extent to which drive shaft 13 can shift axially to the left. Instead of using a second axial bearing to limit the extent to which drive shaft 13 can shift axially to the right, a magnetic circuit structure is employed to constantly pull drive shaft 13 leftwards, and thereby keep shoulder 30 pressed leftwards against the end face 20 of radial bearing 12.
This magnetic circuit structure includes two permanent magnets 16, 17 secured to a soft-iron yoke plate 18 screwed on machine housing 115. The circuit for magnetic flux is completed by a soft-iron annular plate 19 secured to the left axial end face of external rotor 14. The annular plate 19 is pulled leftwards towards the permanent magnets 16, 17 and firmly presses shoulder 30 leftwards against the right end face 20 of radial bearing 12. In this embodiment, the stator 15 can be pulled rightwards out of the rotor 14, and the rotor will stay in place due to the magnetic holding force.
In the embodiment of FIG. 3, the rotor can be pulled off rightwards from behind. Here, the stator 25 is located at the side of the rotor 24 which faces towards the cassette to be driven, and the stator 25 is secured directly to the machine housing 21. A radial bearing 22 is secured in a bore in housing 21. As before, the rigidly connected together rotor 24 and drive shaft 23 are mounted by virtue of the fact that drive shaft 23 extends from rotor 24 through radial bearing 22. It will be understood that radial bearing 22 is nonrotatable. The axial locating of the drive shaft 28 is performed by an axial bearing 200, 300. Numeral 200 denotes a bearing plate secured to a U-shaped bracket 80 in turn secured to machine housing 21. The right end face 300 of drive shaft 23 may be hemispherical or, for example, conical. Two permanent magnets 26, 27 are secured to U-shaped bracket 80, which latter is preferably of soft iron. Secured to the right axial end face of rotor 24 is a soft iron annular plate 29 which completes the path for magnetic flux. The permanent magnets 26, 27 pull annular plate 29, and therefore rotor 24 and drive shaft 23 rightwards, thereby pressing bearing surface 300 against bearing plate 200. U-shaped bracket 80 is rigidly but dismountably secured to machine housing 21.
Advantageously, the drive motor employed is a collectorless D.C. motor provided with ferromagnetic structure generating a compensatory reluctance torque, such as disclosed in commonly owned U.S. Pat. No. 3,840,761 or in commonly owned U.S. patent application Ser. No. 706,550 filed July 21, 1976, the entire disclosures of which are incorporated herein by reference.
In the illustrated embodiments, the cassette machine is of the direct-drive type, i.e., wherein the tape drive shaft is constituted by the motor shaft itself. However, an indirect drive can likewise be employed as shown in FIG. 4, in which case it is preferred to provide the indirectly driven tape drive shaft with a coaxial flywheel to improve the constancy of its rotary speed.
It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above.
While the invention has been illustrated and described as embodied in particular cassette-machine designs, 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, fairly constitute essential characteristics of the generic or specific aspects of this invention.
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A magnetic-tape cassette machine of the type including a horizontally extending tape drive shaft and a loading platform designed to hold the cassette upright during tape transport. To prevent the horizontally extending tape drive shaft from shifting axially during tape transport, one end of the shaft is supported against a first axial bearing secured to the machine housing and the other end is supported by an axial bearing secured to the loading platform. Alternatively, a single axial bearing is used limiting axial shifting of the tape drive shaft in one direction, and a permanent-magnet arrangement pulls the tape drive shaft in the same direction to prevent the shaft from shifting axially in the opposite second direction.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a system and method for real time deposition process control, where the control is based on a detection of resulting products, and more particularly, to a system and method for real time deposition process control based on resulting product detection, where the deposition process is an atomic layer deposition (ALD) process or a chemical vapor deposition (CVD) process.
2. Description of the Related Art
FIG. 1 is a schematic diagram of a conventional method for controlling a deposition process, disclosed in U.S. Pat. No. 6,210,745. As illustrated, FIG. 1 , includes a deposition chamber 150 for performing a chemical vapor deposition (CVD) process on a wafer 156 . A residual gas analyzer (RGA) 152 , for analyzing gases by ionizing gas molecules and separating ions by mass, is mounted on the deposition chamber 150 . The RGA 152 analyzes the resulting gases during the CVD process performed on the wafer 156 to acquire RGA data associated with processing parameters of the CVD process.
Subsequently, the wafer 156 , having undergone the CVD process, is unloaded from the deposition chamber 150 and is then transferred to a measurement chamber 154 for measuring the thickness or other electrical properties of a thin film deposited on the wafer 156 . If the measured values are different from processing target values, various processing parameters of the CVD process are adjusted.
Using the conventional technology described in U.S. Pat. No. 6,210,745, produced wafers 156 that do not satisfy the processing target values (within a given tolerance) cannot be reworked. Further, if the measurement time for the sample wafers is increased, all the following wafers on which the process is performed for a given time also will not satisfy the processing target values. As a result, many wafers are produced, which are not usable.
SUMMARY OF THE INVENTION
The present invention is intended to solve one or more of the above-described problems by providing a system and method for real time deposition process control based on resulting product detection, where the system and method detect an amount of at least one reaction product in real time, while the deposition process is being performed, the detected amount of reaction product is compared with a reference amount, and a comparison result is fed back in real time to adjust a supply of one or more reactants. The system and method of the present invention provide real time control over the deposition process and/or reduce the number of wafers produced that do not meet processing target values.
The above advantage is accomplished in one exemplary embodiment, by providing a real time control system comprising a reaction chamber in which a deposition process is performed on a wafer, a reactant supply for supplying at least one reactant into the reaction chamber, a detector, detecting an amount of at least one reaction product in real time, while the deposition process is performed in the reaction chamber, and a controller for comparing the amount of the at least one reaction product detected by the detector with a reference amount and feeding back a comparison result to the reactant supply in real time to adjust a supply of the at least one reactant.
The above advantage is also accomplished in one exemplary embodiment, by providing a real time control method for a deposition process, comprising supplying at least one reactant into a reaction chamber where the deposition process is performed, detecting an amount of at least one reaction product in real time, while the deposition process is performed in the reaction chamber, and comparing the amount of the at least one reaction product detected with a reference amount to obtain a comparison result and adjusting a supply of the at least one reactant in real time in accordance with the comparison result.
The deposition process can be applied to such exemplary processes as an atomic layer deposition (ALD) process and a chemical vapor deposition (CVD) process.
The controller may control the supply or non-supply of the reaction product by the amount of the resulting product monitored by the detector. Also, the controller may control the supply amount of the reaction product by the amount of the resulting product monitored by the detector.
According to another aspect of the present invention, there is provided a real time controlling method of a chemical vapor deposition process, the method including the steps of loading a wafer where a deposition process is performed, into a reaction chamber, supplying reaction gases into the reaction chamber from a reaction gas supplying portion and performing a chemical vapor deposition process on the wafer, real time monitoring the amount of the resulting gas generated during the chemical vapor deposition process, comparing the amount of the resulting gas real time monitored with a reference amount, feeding back the comparison result to the reaction gas supplying portion, and controlling the supply of the reaction gas and the deposition time in a CVD process in real time.
Alternatively, the present invention provides a real time controlling method of an atomic layer deposition process, the method including the steps of loading a wafer where a deposition process is performed, into a reaction chamber, supply of a first reaction gas into the reaction chamber and allowing the first reaction gas to be adsorbed into the wafer, stopping supplying the first reaction gas, purging the excess of the first reaction gas and exhausting the purged first reaction gas from the reaction chamber, supplying a second reaction gas into the reaction chamber and depositing a resulting gas generated by the reaction between the first and second reaction gases on the wafer, stopping supply of the second reaction gas, purging the resulting gas and exhausting the purged resulting gas from the reaction chamber, real time monitoring the amount of the resulting gas generated during the atomic layer deposition process, comparing the amount of the resulting gas real time monitored with a reference amount, feeding back the comparison result to a supplying portion of the first reaction gas, and controlling the supply of the first reaction gas and the process cycle in an ALD process in real time.
A cycle consisting of the steps of adsorbing the first reaction gas and exhausting the resulting gas is preferably repeated one or more times.
In one or more embodiment of the present invention, the controller preferably controls the supply or non-supply of at least one reaction product depending on an amount of at least one resulting product, monitored by the detector.
According to one or more embodiments of the present invention, since the resulting gases generated during the CVD process or ALD process are monitored in real time by the detector and a monitoring result is compared with a reference amount which is fed back, the thicknesses or other electrical properties of thin films deposited by the selected deposition process can be controlled on a real time basis.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more apparent by describing in detail preferred embodiments thereof with reference to the attached drawings in which:
FIG. 1 is a schematic diagram of a conventional method for controlling a deposition process;
FIG. 2 is a schematic diagram of a real time control system according to an embodiment of the present invention;
FIG. 3 is a graph showing the relationship between the feeding concentration of ozone and the intensity of ethane generated in an atomic layer deposition process according to an embodiment of the present invention;
FIG. 4 is a timing chart of the atomic layer deposition process according to an embodiment of the present invention;
FIG. 5 is a flow chart of the atomic layer deposition process according to an embodiment of the present invention; and
FIG. 6 is a flow chart of a chemical vapor deposition process according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Several embodiments of the present invention will now be described in more detail with reference to the accompanying drawings. However, the present invention is not limited to the following embodiments and is embodied in various forms. Rather, these embodiments are provided only so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those who have ordinary skill in the art.
FIG. 2 is a schematic diagram of a real time control system according to an embodiment of the present invention.
Referring to FIG. 2 , a wafer 14 on which a deposition process is to be performed, is mounted on a stage 12 in a deposition chamber 10 . A reaction or processing gas supplying portion 20 for supplying reaction or processing gases to the deposition chamber 10 is connected to the deposition chamber 10 . A vacuum pump 30 for maintaining the deposition chamber 10 vacuum is connected to the deposition chamber 10 (in a preferred embodiment, the lower part of the deposition chamber 10 ) as illustrated in FIG. 2 .
Also, a detector 40 for real time detection of the resulting gases generated by the reaction of the reaction or processing gases, while the deposition process is performed, is mounted in or on the deposition chamber 10 . A controller 50 is connected to the detector 40 , and compares the amount of the resulting gases monitored by the detector 40 with a reference amount (for example from a correlation table, such as those used in U.S. Pat. No. 6,210,745) on a real time basis to then feed back the comparison result to the reaction or processing gas supplying portion 20 and/or the vacuum pump 30 . In one embodiment, a quadruple mass spectroscopy (QMS) is employed as the detector 40 , however, other types of residual gas analyzers (RGAs) may also be used including an infrared (IR), inductively coupled plasma (ICP), time of flight (TO F) mass spectrometer, or ultraviolet (UV) detection system.
RGAs can measure levels over a wide range of pressures. RGAs identify the gases present in vacuum environments by producing a beam of ions from samples of the gas, separating the resulting mixture of ions according to their charge-to-mass ratios, and providing as output signal which is a measure of the relative species present. RGAs differ from other mass spectrometers by their high sensitivity and their ability to withstand baking so that gases from the RGA can be desorbed. This allows gases of low partial pressure to be identified without being obscured by contributions from the analyzer itself.
Although numerous techniques have been developed for mass separation, the rf quadrupole is the most popular design for use in RGAs. The quadrupole includes four cylindrical rods, to which is applied a combination of dc and ac potentials. For a given applied frequency, only ions of a particular mass-to-charge ratio pass through to the collector. Since they do not require a magnetic field, quadrupoles are much less bulky than magnetic mass analyzers allowing them to be mounted directly onto vacuum systems.
The RGA may be connected to the vacuum chamber with a valve that will permit monitoring the background when the system is evacuated to the high-vacuum range. It may also be connected to a parallel leak valve for use when the chamber is being operated at higher (e.g., sputter) pressures. RGAs are essentially specified by the following characteristic properties:
1. Peak Width—measured in atomic mass units (amu) is specified for at least two positions of the peak—for 50% and 10% of the peak height. The peak width is characteristic of the mass resolution of the RGA. 2. Mass Range—specifies the lightest and heaviest singly charged ions that can be detected. 3. Smallest Detectible Partial Pressure—is the partial pressure that causes a collected current greater than the system noise amplitude. 4. Linear Range—is the pressure region over which the sensitivity between the given limits (e.g., ±10%) remains constant. 6. Sensitivity—is the quotient of the ion current at the collector and partial pressure of the gas present in the ion source. 7. Scan Rate—is the speed at which the RGA sweeps the ion beams of all masses in a given mass range across the collector and records the resulting spectrum.
Although generally shown in FIG. 2 , the real time control system can be applied to ALD and CVD processes, among others. FIG. 3 is a graph showing an exemplary relationship between the feeding concentration of ozone and the intensity of ethane generated in an atomic layer deposition process according to one embodiment of the present invention. When performing an ALD process on alumina (Al 2 O 3 ) using trimethylaluminum (TMA, Al (CH 3 ) 3 ) and ozone (O 3 ), the following reaction occurs:
2Al(CH 3 ) 3 +O 3 →Al 2 O 3 +6C 2 H 6
The thickness of an alumina film deposited on the wafer in units of atoms based on the above reaction is proportional to the amount of ethane C 2 H 6 , that is, a resulting gas. Thus, the thickness of the alumina film can be monitored in real time by the amount of ethane generated after reaction.
It can be ascertained from FIG. 3 that the intensity of ethane measured by QMS proportionally increases as an ozone feeding concentration increases. Based on the measurement result, the controller ( 50 of FIG. 2 ) can determine whether the reaction or processing gases of the reaction or processing gas supplying portion 20 are to be supplied or not, by real time monitoring the intensity of ethane resulting from the ALD process performed on alumina.
FIG. 4 is a time chart of the ALD process according to one embodiment of the present invention.
Referring to FIGS. 2 , 4 and 5 , a process of real time controlling the ALD process according to one embodiment of the present invention will now be described.
First, the wafer 14 is loaded into the deposition chamber 10 maintained at a constant vacuum degree by the vacuum pump 30 (step S 10 ). Then, the first reaction or processing gas, i.e., a TMA gas, is fed into the deposition chamber 10 from the reaction or processing gas supplying portion 20 so that TMA gas molecules are adsorbed onto the surface of the wafer 14 (step S 20 ; a portion “A” shown in FIG. 4 ). Next, the supply of TMA gas molecules is stopped and then an inert gas or a noble gas, e.g., nitrogen gas, is fed as a purge gas into the deposition chamber 10 . Excessive TMA gas molecules that are not adsorbed or unstably physically adsorbed onto the surface of the wafer 14 are removed from the deposition chamber 10 (step S 30 , a portion “B” shown in FIG. 4 ).
Subsequently, the second reaction gas, i.e., ozone gas, is fed into the deposition chamber 10 from the reaction or processing gas supplying portion 20 to allow the ozone gas as the second reaction gas to react with the TMA gas molecules as the first reaction gas, thereby forming an alumina layer of a single atomic layer on the wafer 14 (step S 40 ; a portion “C” shown in FIG. 4 ). Then, the supply of the ozone gas is stopped and a purge gas is supplied to allow unreacted ozone gas or resulting ethane to be purged and removed from the deposition chamber 10 (step S 50 ; a portion “D” shown in FIG. 4 ).
The ALD process is generally repeatedly performed in a period of cycles each consisting of the steps S 10 , S 20 , S 30 , S 40 , S 50 , and S 60 . A single alumina layer is formed on the wafer 14 during one cycle.
After the wafer 14 is loaded into the deposition chamber 14 (step S 10 ), the intensity of ethane, which is a resulting gas, is real time monitored by the detector 40 connected to the deposition chamber 10 .
The intensity of ethane monitored during the process (to be abbreviated as I process ) is real time compared with a reference intensity (I ref ) (step S 60 ). If I process is smaller than I ref , a new cycle of the ALD process is again performed, that is, TMA is fed again (step S 20 ). However, if I process is greater than or equal to I ref , the cycle of the ALD process is stopped and the wafer 14 is unloaded from the deposition chamber 10 (step S 70 ).
FIG. 6 is a flow chart of a chemical vapor deposition (CVD) process according to one embodiment of the present invention.
Referring to FIGS. 2 and 6 , a process of real time controlling the CVD process according to one embodiment of the present invention will now be described. In this embodiment, a silicon nitride layer is subjected to the CVD process using ammonia (NH 3 ) and dichlorosilane (DCS (SiH 2 Cl 2 ) as processing gases, and the chemical reaction is as follows:
4NH 3 +3DCS(SiH 2 Cl 2 )→Si 3 N 4 +6HCl+6H 2
First, the wafer 14 is loaded into the deposition chamber 10 maintained at a constant or substantially constant vacuum by the vacuum pump 30 (step S 110 ). Then, ammonia (NH 3 ) and dichlorosilane (DCS (SiH 2 Cl 2 ) as processing gases of a CVD process for a silicon nitride layer are fed into the deposition chamber 10 from the reaction or processing gas supplying portion 20 to perform the CVD process (step S 120 ).
After the wafer 14 is loaded into the deposition chamber 14 (step S 110 ), the intensities of hydrogen chloride (HCl) and hydrogen (H 2 ), which are resulting gases, are real time monitored by the detector 40 connected to the deposition chamber 10 .
The intensity I process of hydrogen chloride or hydrogen monitored during the process is real time compared with a reference intensity I ref (step S 130 ). If I process is smaller than I ref , the processing parameters of the CVD process, e.g., the amount of processing gases, the processing time or the processing pressure, are adjusted on a real time basis. However, if I process is greater than or equal to I ref , the CVD process is stopped without adjusting the processing parameters and the wafer 14 is unloaded from the deposition chamber 10 (step S 140 ).
According to the present invention, resulting gases generated while an ALD process or CVD process is performed in a deposition chamber, are real time monitored and the monitoring result is real time compared with a reference. Thus, determination of continuous performance of the deposition process or adjustment of processing parameters is fed back in real time, thereby more accurately controlling the deposition process and reducing processing inferiority, leading to improvement in manufacturability.
Although the present invention has been described above in conjunction with numerous embodiments, these embodiments may be varied as would be known to one of ordinary skill in the art. For example, although the reaction, processing and resulting materials are described as gases, these materials could also be any combination of gases, liquids and if possible, solids. Further, although the system and method are described as performing the functions of monitoring and controlling, only one of these functions could also be performed. Still further although the exemplary chemistry describes reactions producing Al 2 O 3 and Si 3 N 4 , reactions producing TiO 2 , Ta 2 O 5 and other materials are also considered within the scope of the present invention. Still further, although an amount of resulting gas is detected, any other useful parameter could also be utilized for detection. For a CVD process, these parameters may include a portion of a reactant gas, a quantity of a reactant gas, and a deposition time, among others known to one of ordinary skill in the art. For an ALD process, these parameters may include a portion of a reactant gas, a quantity of a reactant gas, and a total process cycle, among others known to one of ordinary skill in the art. Still further, although the system and method are described as performing deposition, the techniques of the present invention could also be applied to other processes, such as end point detection or other etching processes.
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A system and method for real time deposition process control based on resulting product detection, where the system and method detect an amount of at least one reaction product in real time, while the deposition process is being performed, the detected amount of reaction product is compared with a reference amount, and a comparison result is fed back in real time to adjust a supply of one or more reactants. The system and method provide real time control over the deposition process and/or reduce the number of wafers produced that do not meet processing target values.
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GOVERNMENT RIGHTS
The present invention has been made under the contract with the Department of Energy and the government may have certain rights to the subject invention.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method and apparatus for measuring molecular alignment and crystallinity of polymer fibers and films, and more particularly to a method and apparatus for measuring diameter, and birefringence of fibers in real time during production.
2. Related Art
In the field of synthetic fiber and film manufacturing, it is desirable to measure the molecular alignment, or crystallinity, of polymer fibers and films to determine the degree of solidification, or other characteristics of the fiber, at a particular time. When a fiber or film is created at a factory, it is drawn or stretched, which tends to orient the crystals. The fiber has an index of refraction across the length of the fiber and has another index of refraction along the length of the fiber. The difference between these indices of refraction is the birefringence of the fiber. The birefringence is a good indicator of the degree of crystallinity or degree of orientation of the crystals comprising the fiber. It is highly desirable to determine the birefringence of a fiber or a film during the production process while it is moving from a liquid state to a solid state. In the past, the only way to obtain such a measurement, has been to halt the manufacturing process, obtain a sample of the fiber or film and perform off-line analysis in a laboratory, where the fiber or film is immersed in calibrated oils until it disappears, which means the index of refraction of the surrounding material is equal to the index of refraction of the fiber. This is an expensive and time consuming process, and is very disruptive to the manufacturing process. Another problem is that a plurality of fibers are drawn from a spinner, which looks like a shower head, so it is impossible to position equipment in front and behind a particular fiber.
Accordingly, what is desired, and has not been heretofore developed, is a method and apparatus for measuring microstructures, anisotropy and birefringence in fibers and films during the production in real time, without interrupting the manufacturing process.
Previous attempts in this area include the following:
Massen, U.S. Pat. No. 4,887,155, which discloses a method of measuring or monitoring properties of yarns using an image sensor to obtain a two-dimensional image of a portion of the yarn which is converted to an electrical image signal. The signal is digitized and the values of the properties to be detected are determined.
Siegel et al., U.S. Pat. No. 5,015,867, discloses a method and apparatus for measuring the diameter of a moving fiber using lasers and charged coupled devices for sensing the diffraction and interference patterns produced when electromagnetic radiation emitted from a laser is partially obscured by the edges of the strand. Information contained in the diffraction pattern may be extracted in a number of ways such as, for example, comparing the measured diffraction pattern with a theoretical pattern produced by a knife edge as calculated using the Kirchhoff-Fresnel integral.
Noguchi, et al., U.S. Pat. No. 5,257,092, discloses a polarization and birefringence measuring device utilizing a wide polarized light beam to impinge on a specimen. A photo detecting sensor detects the light beam containing information about the specimen. An analyzer is used to vary the amount of light transmitted. A computer analyzes the polarization states of parts of the specimen corresponding to the samples taken.
Rochester, U.S. Pat. No. 5,264,909, discloses a method and apparatus for measuring the diameter of an optical fiber as the fiber moves past the measuring apparatus. The device includes a number of discreet, stationery light sensors arranged in a linear array, a light source positioned to shine a beam of light onto the sensors of the array and a lens that directs an enlarged image of the optical fiber onto the array of light sensors. Each light sensor produces an output signal responsive to the intensity of light it receives.
Urruti, U.S. Pat. No. 5,443,610, discloses an apparatus for controlling fiber diameter by taking two measurements of the fiber diameter and combining the measurements into a control signal. The first measurement is made on the bare fiber and the second measurement is made after a hermetic coating has been applied to the fiber.
Ducharme, et al., U.S. Pat. No. 5,657,126, discloses an ellipsometer having a phase-modulated polarized light beam which is applied to a sample. Electric signals are obtained representing the orthogonal planes of polarization after the light has interacted with the sample and the constants of the sample are calculated from the two resulting electric signals.
Yoshita, U.S. Pat. No. 5,619,325, discloses an ellipsometry optical system for analyzing light beams reflected from or transmitted through materials. The device includes a light source, a beam splitter, an optical frequency shifter for shifting a frequency of one of the light beams split by the beam splitter to form a reference light beam, a circular polarization converter for circularly polarizing the other light beam to form a probing light beam, a second beam splitter for combining the reference beam and the probing beam, a birefringence prism for receiving the combined beam and separating polarization components and a photo detector for converting the polarization components to electrical signals.
None of these previous efforts, taken either alone or in combination, teach or suggest all of the elements of the present invention, nor do they disclose all of the benefits and advantages of the present invention.
OBJECTS AND SUMMARY OF THE INVENTION
It is a primary object of the present invention to measure the alignment and crystallinity of polymer fibers during the production thereof in real time.
It is another object of the present invention to measure the birefringence of fibers and/or in real time to determine properties of fibers or films during the manufacturing process.
It is still an additional object of the present invention to use lasers to measure properties of fibers during the manufacturing process.
It is still an additional object of the present invention to utilize laser light scattered by textile fibers during the manufacturing process to determine characteristics of the fibers.
It is still an additional object of the present invention to direct lasers at moving fibers to scatter the laser light to form an interference pattern which is dependent upon the diameter of the fiber and the orientation and structure of the polymer molecules within the fiber, and to obtain information about orientation and structure of the fiber.
It is even an additional object of the present invention to analyze the interference pattern of laser light scattered by fibers to determine the degree and nature of alignment of polymer chains and other physical characteristics of the fiber, including strength, elasticity and surface smoothness.
It is an additional object of the present invention to utilize information obtained in real time about textile fibers to allow process adjustments to be made immediately during production allowing for improved process reproducibility, efficiency and quality control and eliminating the need to overproduce to ensure adequate supply of fiber with consistent characteristic.
It is, accordingly, another object of the present invention to provide an improved textile production process with increased reproducibility, efficiency and quality control.
It is another object of the present invention to save money associated with the halting of the manufacturing process for testing.
It is an additional object of the present invention to overcome the need to test products off line in laboratories.
A method and apparatus for measuring microstructures, anistropy and birefringence in fibers using laser scattered light includes a laser which provides a beam that can be conditioned and is directed at a fiber or film which causes the beam to scatter. Backscatter light is received and processed with detectors and beam splitters to obtain data. The data is directed to a computer where it is processed to obtain information about the fiber or film, such as the birfringence. This information provides a basis for modifications to the production process to enhance the process.
BRIEF DESCRIPTION OF THE DRAWINGS
Other important objects and features of the invention will be apparent from the following Detailed Description of the Invention when read in context with the accompanying drawings in which:
FIG. 1 is a schematic drawing of an apparatus for determining birefringence according to the present invention.
FIG. 2 is a graph of the components of the ellipticity polarized backscattered laser light.
FIG. 3 is a schematic drawing of another embodiment of the apparatus shown in FIG. 1.
FIG. 4 shows a schematic for obtaining a scattered pattern through a filament, and the pattern obtained.
FIG. 5 shows a schematic for obtaining a scattered pattern at an angle and the scatter pattern.
FIG. 6 shows a scattering pattern at a 45 degrees.
FIG. 7 shows a scattering pattern at 45 degrees from a necked fiber.
FIG. 8 shows a large angle scattering pattern for Camac Navy undrawn filament.
FIG. 9 shows a large angle scattering pattern for Camac Navy drawn filaments.
FIG. 10 shows a ray path diagram for rays instant on a fiber.
FIG. 11 shows the scattering patter from an ideal 20 micron and an ideal 10 micron filament.
FIG. 12 shows a backscatter pattern from 10 micron filament and backscatter patterns for 20 micron filament.
FIG. 13 shows a typical backscatter pattern for an A1 fiber.
FIG. 14 shows an internal electric field pattern for λ/d=1.58.
FIG. 15 shows an electric filed pattern for internal electric fields of λ/d=7.9.
FIG. 16 shows an electric filed pattern for internal electric fields of λ/d=15.8.
FIG. 17 shows an electric field pattern for internal electric fields of λ/d=31.6.
FIG. 18 shows an electric field pattern for internal electric fields of λ/d=31.6 and n=(1.5,0.1) for a highly absorbing fiber wherein the probe region is limited to a surface layer.
FIG. 19 shows a scattering patter for a very small inhomogeneity.
FIG. 20 shows a scattering pattern from a thin 1 micron long structure.
FIG. 21 shows the scattering pattern from many partially correlated 1 micron structures.
FIG. 22 is a schematic drawing of an experimental set out for transmission of birefringence measurements.
FIG. 23 is a plot of the transmission vs birefringence for various probing wavelengths.
FIG. 24 is a graph of light transmitted through crossed polarizers vs birefringence.
FIG. 25 shows a graph of comparison of birefringence measurements from depolarization measurements vs industry standard technique.
FIG. 26 shows a graph of the effect of filament diameter on spot pattern.
FIG. 27 is a graph of primary spot amplitude vs angle for two polarizations.
FIG. 28 is a graph showing the effect of birefringence on spot pattern.
FIG. 29 shows the backscatter pattern from a fiber.
FIG. 30 is a graph of the fit of highest frequency Fourier component of the data shown in FIG. 29.
FIG. 31 shows an experimental set up for reflection tests of birefringence.
FIG. 32 is a polar polarization plot for various bundles tested by the test set-up of FIG. 31.
FIG. 33 is a comparison of measured and expected relative modulation levels.
FIG. 34 is a cross-sectional view of a trilobal fiber.
DETAILED DESCRIPTION OF THE INVENTION
The present invention utilizes laser scattered light for measuring microstructures, anistropy and birefringence in fibers and films. Importantly, the method and apparatus of the present invention allows for the measurements of such properties in fibers and films during the production process in real time. Accordingly, process adjustments can be made during the production process to increase the efficiency of the process and increase the quality of the product.
Lasers operating in the infrared, visible and ultraviolet wavelength ranges can be used to monitor physical characteristics of synthetic fibers in accordance with the present invention. The laser light is directed at and scattered by the textile fibers during and immediately following the solidification of the extruded fibers and during the drawing process.
Two classes of measurements can be undertaken: a passive measurement and an active measurement. In the passive case, low-power laser light in the visible or near infrared frequency range is scattered by the moving fiber, forming an interference pattern which is dependent upon the diameter of the fiber and the orientation and structure of the polymer molecules within the fiber. The degree and nature of alignment of polymer chains is related to physical characteristics of the fiber, including strength, elasticity and surface smoothness. The greater the degree of the alignment, the stronger the fiber. The lesser the degree of the alignment, the greater the elasticity. Periodic variations in the structure of the polymer chain in the direction of the fiber movement can also be gleaned from changes in the scattering patterns with time, indicating changes in fiber properties. These changes can be caused by mechanical wobble, which if uncorrected, could render the fiber useless.
In the active case, light from the powerful infrared or ultraviolet lasers incident on the fiber is absorbed by the molecules and readmitted at a different wavelength. Spectroscopic analysis of the scattered light yields additional information on the chemical and physical composition of the fiber material. This allows manufacturers to control and maintain the chemical consistency of the product and related properties such as dye distribution and concentration.
In the factory, fibers are drawn out of a spinneret which includes a plurality of apertures through which the liquid is drawn. Because of this configuration, one cannot isolate a particular fiber and install equipment in front of and behind a typical analysis. Accordingly, the present invention utilizes the backscatter component of the laser beam on a fiber, i.e. that portion of the scattered light that is directed back at the laser beam, i.e., 180 degrees backscatter. A mirror can be used to obtain the backscatter which can be then analyzed to determine the product of the birefringence times the diameter of the fiber.
Referring to FIG. 1, an embodiment of the basic apparatus of the present invention is shown schematically. The device includes a housing 30 which houses a laser 40. The laser can be any type of laser known in the art such as a laser that operates in the infrared, visible or ultraviolet wavelength range. One suitable type of laser would be a helium neon laser.
The laser 40 emits a laser beam 42. The laser beam 42 is conditioned by polarization elements 44 and 46. The polarizers may be glass or acilinide that may have special coatings depending upon the wavelength. A chopper 47 may be utilized to modulate the beam by imposing a frequency on the laser beam 42. The polarized laser beam 48, the polarization of which is indicated by polarization symbol 49, is sent through aperture 56 of mirror 54 and out of the housing, through housing aperture 50. A portion of the polarized laser beam 48 is backscattered at 180 degrees, and this backscattered beam 52 comes back towards the aperture 50 and the housing 30 and passes through the aperture 50 and contacts mirror 54. The mirror 54 reflects the backscattered beam 52 through lens 58, and through some optical elements such as beam splitter 60 which separates the beams into first component 62 and second component 64. First component 62 is directed to a detector 66. The second component 64 passes through a second beam splitter 68 where it is split into third beam 70 and fourth beam 72. The third beam 70 is directed to second detector 74 and fourth beam 72 is directed to third detector 76.
Because the polarized beam has an elliptical polarization, it generally takes three detectors to determine the ellipticity of the light. See FIG. 2. The ellipticity of the light is proportional to the product of the birefringence and the diameter of the fiber. The detectors can be any desired detectors. For a helium laser, it may be desirable to use photo voltaic cells. Lock-in amplifiers interconnected with the detectors can be used to take modulated signal and filter out the noise, i.e., a very narrow band filter. Thereafter, the data is fed to a computer which analyzes the data as will hereinafter be discussed.
Importantly, it is desirable to position the laser to impact against the fiber at 45 degrees to obtain the most information, and accordingly, the controlling computer program must periodically check to determine that the apparatus maintains its position at 45 degrees with respect to the fiber which may move and or change as it is being drawn. It should also be noted that two independent measurements of the birefringence are necessary in order to get information and accordingly, two laser beams of two different wavelengths are required.
Referring now to FIG. 3, which is another embodiment of the invention shown in FIG. 1, like numerals represent like elements. A laser generally indicated at 140 emits a laser beam 142 which passes through a polarizer 144, a liquid crystal retarder 145, and an achromatic 1/4 (one quarter) wave plate 147. The conditioned beam 148 is directed through an aperture 156 in a mirror 154 to contact a fiber 125 being from a drawing machine. The conditioned, beam then scatters causing a backscattered beam 152 which contacts the mirror 154 and is reflected to a horizontal lens 158 which directs the beam to first beam splitter 160 which splits the beam into two parts, the first part of which 162 passes through a polarizer 163 to a detector 166. The second part of the beam 164 is directed to another beam splitter 168 which splits the beam into two parts, third beam 170 which passes through a polarizer 171 which directs the beam to detector 174 and fourth beam 172 which passes through polarizer 173 to third detector 176. Lock-in amplifiers 182 are interconnected with the detectors 166, 174 and 176 respectively, and the resulting signals are sent to computer 190 for processing.
Scattering Patterns
The method of interpretation of the data by the computer results from experimental observations from a number of models. Most polymer filaments are at least partially transparent and have a high refractive index and refraction is expected to be the dominant effect. A forward scattered pattern is typical of such filaments. The pattern is banded and band position and period depend on filament shape, size and index of refraction. Most of the rays that generate the pattern have sampled most of the filament volume and therefore carry line integrated information on the dielectric constants of the sample and could be used as the basis of birefringence measurements. Single filaments were illuminated with monochromatic radiation from an He--Ne laser and the scattering pattern was sampled using a 2D CCD detector.
FIG. 4 shows the dominant pattern of light transmitted and refracted through a deeply pigmented nylon filament (Camac Nylon/Navy Blue). This forward scattered pattern is typical of all the filaments tested. The pattern is banded and band position and period depend on filament shape, size and index of refraction. Most of the rays that generate this pattern have sampled most of the filament volume. They therefore carry line integrated information on the dielectric constants of the sample and can be used as the basis of birefringence measurements.
FIGS. 5 and 6 show the weaker equatorial patterns generated at other scattering angles. As will be discussed later, these are of the form expected from diffraction effects and cannot be calculated from simple ray tracing. The period of the spot pattern depends primarily on the filament diameter. The amplitude (intensity) and position of the spots depend on index of refraction of the filament. The vertical height of the spots reflects the diameter of the probing laser beam. An unexpected feature is the distortion in the spot and the sidebands that appear above and below the primary spots.
A more characteristic patter is shown in FIG. 6. There is considerably more structure in these patterns. The additional bands indicate inhomogeneities along the axis of the filament. The larger the separation from the primary spot structure the finer the structure. As an approximate guide, the horizontal separation in the primary spots can be used as a ruler to estimate the size of the inhomogeneities along the filament axis. The bands in FIG. 6 indicate the existence of inhomogeneities along the filament axis; their size is of the order of filament diameter.
FIG. 7 shows the scattering pattern from a necked fiber. The position and separation of the dominant spots is representative of the neck ratio and neck length.
At small scattering angle the patterns stem from large morphological features with a size scale similar to the probing wavelength. At large angles, they carry information on structures with size of the order of a small fraction of the wavelength of the probing radiation. The regular spot pattern due to the filament diameter and gross inhomogeneities no longer appears at wide angles. Wide angle patterns of drawn and undrawn nylon filaments at 45 degrees in the azimuthal plane and at 25 degrees in the equatorial plane, are shown in FIGS. 8 and 9. These patterns are also characteristic of those from PET fibers. Fibers with high crystallinity and higher birefringence show a more coherent structure as indicated in the figures.
Fundamental Models
Ray Tracing and Fraunhoffer Diffraction Models
Ray tracing is the logical first step in trying to understand the scattering patterns. The result of such a calculation is shown in FIG. 10. For clarity only ray paths incident from below the mid-plane are plotted. The results shown are independent of the actual filament diameter and depend only on the index of refraction. The light is incident from the left of the image; an index of refraction of 1.5 was assumed. The dotted lines below the mid-plane are rays reflected from the front of the filament whereas the rays in the upper mid-plane are rays reflected from the back side of the filament. The fuzz that appears just inside the filament are rays that are trapped inside the filament. Ray tracing calculations are useful to estimate the path length a particular light ray has taken. Brightness patterns of the reflected and transmitted light can be determined by calculating the ray density at the position of interest. From FIG. 10 it is evident that all of these patterns will be smooth and cannot reproduce any of the banded patterns observed.
Diffraction effects must be included to reproduce the observed banded patterns. Several diffraction models were tested. All were able to generate spot patterns similar to FIG. 5. The diffraction models allowed determination of the filament diameter to better than 5% accuracy. They did not however accurately reproduce the amplitude or exact position of the dominant spot pattern.
Solution of Maxwell's Equations
Accurate modeling requires solution of Maxwell's equation for propagation of light in the filament. FIGS. 11 and 12 show some typical results from these calculations. Both the forward, side and backscatter patterns can be accurately simulated.
FIG. 12 below shows calculated forward scattering patterns vs angle. Match with observed patterns is good (compare FIG. 5). Filament diameter calculated using the Maxwell solutions agreed with conventional measurements to a precision better than 1%.
Filament diameter can also be obtained from the backscattered patterns. These patterns are also very sensitive to the filament diameter and have been used to calculate filament diameter to an accuracy of a few percent. A typical backscatter pattern is shown below in FIG. 13.
One way to analyze the data is to extract the dominant Fourier component from the data and compare it with the dominant Fourier component from the calculations. Typical results obtained using data similar to the above are described hereinafter.
Solving Maxwell's equation also yields information on internal electric fields. This is important as it determines the region of the filament that is being probed. In essence the region probed is that region which has the highest electric field gradients. FIGS. 14-17 show internal electric field patterns for a variety of probing wavelengths with different rations of probing wavelength to filament diameter. The region probed can be adjusted somewhat by judicious choice of the probing wavelength.
As shown in FIGS. 14-17, the probed region changes with the ratio of the wavelength to filament size. It is also interesting to note that as the ratio of λ/d increases, the electric field patterns start to resemble the ray tracing results shown in FIG. 10. This is particularly true of the near focal region of the rays. For highly absorbing fiber the probed region is limited to a surface layer whose depth depends on the absorption coefficient. This is shown in FIG. 18.
Models For Fine Scattering
Up to this point the scattering patterns caused by relatively large scale inhomogeneities have been considered. As shown in FIG. 19, these cause a scattering pattern which lies primarily in the equatorial plane, with little light scattered out of the plane. Only if there are small scale inhomogeneities will there be significant scattering out of the equatorial plane. In the limit where the scattering inhomogeneity is much smaller than the wavelength of the probing light (Rayleigh scattering), the scattering pattern generated by a single (point like) scattering center is shown in FIG. 19 below. This pattern is simply a very broad featureless blob. If this scattering center were located inside a filament, the resulting scattering pattern would be a convolution of this pattern and the spot patterns created by the filament. The net result would be just a blurring out of the patterns as shown in FIG. 11.
The scattering pattern from single long structure (1 micron in length) is shown in FIG. 20. Here the scattering structure is much thinner than the wavelength but has a vertical extent nearly 2 wavelengths long. Here the detector field is assumed to be flat. As a consequence of a finite longitudinal scattering structure, horizontal bands appear both below and above the primary horizontal band. If the pattern shown in FIG. 17 were now to be convoluted with the spot pattern shown in FIG. 11, we would obtain scattering patterns that would be very close to those observed in FIG. 6.
If we now calculate the scattering patterns of several thousand such long structures, nearly randomly distributed, and with a correlation length of 1 micron we obtain the pattern shown in FIG. 21. We can now qualitatively reproduce the full patterns that are observed. We see the bright forward scattered peak that is located at the center of the pattern. There is the bright primary horizontal band characteristic of the filament diameter, and a rich horizontal sideband structure that loses correlation with the central band as its distance from the central band increases. All of these observations are similar to those seen in experiments.
Experimental Results
Having developed a satisfactory model, various schemes can be considered to measure parameters of interest.
Transmission Technique
The first scheme to be tried is based on the principle that birefringent materials introduce a phase delay that is polarization dependent. A linearly polarized wave that is incident at an angle to an optical anisotropy will no longer be linearly polarized. A schematic diagram that makes use of this feature to measure birefringence is shown in FIG. 22.
This scheme measures a line integrated effect along a given ray path. As a first good approximation, effective ray paths can be calculated from ray tracing as shown in FIG. 10. With non-birefringent material, there will be no net depolarization of the rays and no transmitted light through the second polarizer. As birefringence increases, there will be increasing depolarization and more light will be transmitted. However, further increases in birefringence will eventually cause the transmitted light to decrease as the phase delay between the two polarizations approaches integer wavelengths. A plot showing this effect, for various probing wavelengths is shown in FIG. 23.
The solid line shows the expected fractional transmission vs birefringence for a 22 micron filament and a probing wavelength of 0.6328 microns. As evident in the FIG. 23, there could be an ambiguity in the birefringence value for a given transmission. This ambiguity can be removed by using two or more different probing wavelengths or a sufficiently long wavelength. For this technique to work the sample must be at least partially transparent. This seemed to be true for all samples tested, even the navy blue samples from CAMAC. However, in the case of some dyes which have a very strong resonance (absorption) at the probing wavelength, this technique may not be useful at that particular wavelength. In any case at least two probing wavelengths are needed to make this technique work as there are two unknown parameters, the birefringence and the filament diameter.
A quantitative calculation of the birefringence requires a knowledge of the filament diameter. Using the filament diameter obtained from density and denier we can plot the expected light transmission as a function of birefringence for a series of fibers. This is shown FIG. 24. The solid line is representative of filaments A-1, A-2, and A-3, the dotted line is representative of filament B-5 and H-5. The accuracy of this measurement depends on the slope of the curves shown at the given birefringence. The accuracy is greatest near the 0.5 value in the transmission coefficient and poorest at the minima and maxima of the curves. This effect is illustrated by the shaded boxes shown near the A-4 and H-5 fibers in FIG. 24.
A comparison of the birefringence value obtained using the transmission technique and those obtained from conventional techniques is shown in FIG. 25.
There is excellent agreement between the two measurements. The only point that stands out is the measurement for the B-5 fiber (FIG. 24). The discrepancy could be due to a difference in the filament diameter from the one used in the calculation. An implicit assumption in the interpretation of the transmitted data is that the optical path is identical for rays of both polarizations. At high birefringence value this is no longer the case and a correction must be applied. These correction factors could also account for the observed discrepancy.
This technique is also applicable to non-circular filaments, but it is not obvious if it can be applied to filament bundles or yarns, where the possibility of multiple scattering exists. In tests conducted on PET yarns, it appears that multiple scattering is not fatal to this kind of measurement but this has not been demonstrated.
Side Scattering
As pointed out previously, the spot pattern observed at some angle to the laser beam depends on the filament diameter and the index of refraction. Since the index of refraction measurement is dependent on polarization, it could be used as a means of measuring the birefringence as well as the filament diameter.
We shall first examine the dependance of the spot pattern on filament diameter. In FIG. 26 the spot pattern for filaments of 20 and 21 microns vs angle is plotted. As can be seen, the period of the pattern is very sensitive to the filament diameter, and the period can thus be used as an accurate measure of the diameter.
Since this pattern is due to the interference of light scattered/reflected from various part of the filament one would not expect this pattern to depend on polarization if the scattering filament is practically isotropic. However, one expects changes in the amplitude, since the reflection coefficient is polarization dependent. It is important to verify and quantify this if change in spot position is to be used as a measure of birefringence. A graph of the scattering pattern for vertical and transverse polarization with respect the filament axis is shown in FIG. 27.
As expected there is no change in the period or position of the peaks for the two orthogonal polarizations.
For birefringent fibers, the position but not the period of the patterns shifts as the polarization is rotated. In essence one sees the pattern jiggle back and forth as the polarization is changed. The amount of jiggle depends on the birefringence of the material. This has been confirmed experimentally and is shown in FIG. 28.
The advantage of this technique over the previous one is that the filament diameter is directly measured and does not enter as an additional unknown parameter in the measurement. It also lends itself to cost effective implementation through the use of rotating Ronchi rulings and non-imaging detectors. However, this technique is probably not applicable to filament bundles.
Backscatter
A final technique that was tested is to use the backreflected light as a means of measuring the yarn birefringence and filament diameter. We will first examine the use of the backreflected pattern as a means of measuring the filament diameter. Such a pattern from the A-1 fiber is shown in FIG. 29.
One can do a crude and quick calculation of the filament diameter by extracting the dominant Fourier component from the above data and then matching it to that obtained from those expected for various filament diameters. The result of such a process is shown in FIG. 30.
Using this relatively simple technique it is possible to obtain measurement which agree to a few percent with those obtained from the denier and density.
Backscatter or Reflection
One can also use the polarization dependence of the reflected light to measure birefringence. For non-birefringent materials the amplitude of specularly reflected light depends weakly on the polarization of the incident rays (reflection perpendicular to a surface). For birefringent materials the reflection is strongly polarization dependent. A schematic of the test setup used to verify this concept is shown in FIG. 31.
Here the light from the incident laser beam is modulated in amplitude by a chopper and polarization modulated with a photo-elastic modulator. This was done to make the measurement amplitude independent, so that the ratio of the signals seen by the two lock-in amplifiers is a measure of the birefringence. A typical result obtained from fiber bundles is shown in FIG. 32. Here the ratio of the signal for varying polarization angle and for three fibers with different degree of birefringence is plotted.
Here the 130-310 degree axis correspond to a polarization aligned perpendicularly to the yarn, whereas the 40-220 axis correspond to a polarization parallel to the yarn. As expected there is little difference in the relative signal for the cross-polarized case and a significant difference for the co-polarized case. As can be seen from FIG. 32, there is a clear difference in the polarization patterns for the three case studies. There are two contributions to the backscattered signal, a dominant one due to specular scatter and one due to multiple scattering or complex bounding around. In addition there are several form factors that go into the instrumental response of the apparatus depicted in FIG. 31. If one assumes that all of these factors remain the same for the various bundles tested and uses the signal from one of the bundles as normalizer, FIG. 33 is obtained.
FIG. 33 shows the expected modulation depth vs the measured modulation depth for the three fibers studied. Fiber H-5 was used as the normalizing fiber. For A-4 fiber there is a 12% discrepancy between the measured and expected modulation levels. This translates into a similar uncertainty in the birefringence value. Much more information than was shown or used in the analysis is available from the apparatus in FIG. 31. In particular phase information or the details of the ellipticity of the scattered light carries additional information on non-specular components. This information has not yet been folded into the analysis. Techniques such as correlation interferometry (using broad band sources) and dispersion interferometry will be tested as a way of removing errors due to multiple scattering effects. Finally the use of much longer probing wavelengths (sub mm to mm wavelength) is another technique that would make the interpretation of the backscattering data simpler. These long wavelengths will not be able to resolve the individual filament and thus make bulk measurements over the full bundle.
Computer Interpretation of Data
Computer codes have been developed which can solve for the scattered electromagnetic waves by a specified dielectric body in two dimensions. Fortran codes are written which solve an integral equation for the scattered waves numerically by piece-wise point matching method.
Consider a harmonic wave incident in free space on a two-dimensional dielectric cylinder of arbitray cross sectional shape. The incident wave may be a TM or TE mode. The dielectric cylinder is assumed to have the same permeability as free space (μ=μ 0 ). The dielectric material is assumed to be linear and isotropic but it may be inhomogeneous with respect to the spatial coordinates:
ε=ε(x,y)
whereas ε represents the complex permittivity.
Let E represent the total electric field intensity; that is, the field generated by the source in the presence of the dielectric cylinder. The scattered field E S is defined to be the difference between the total and the incident fields. Thus
E=E.sup.i +E.sup.S
From Maxwell's equations for a dielectric body, the scattered field may be considered generated by a equivalent electric current radiating in unbounded free space, where the current density is given by
J=jω(ε-ε.sub.0)E
with ω representing the angular frequency 2πf.
It is well-known that the field of an electric current filament dI parallel to the z axis in free space given by
dE.sup.S =-z(ωμ/4)H.sub.0.sup.(2) (kρ)dI
where H 0 .sup.(2) (kρ) is the second kind Hankel function of order zero, ρ is the distance from the current filament to the observation point and k=2π/λ where λ is the free space wavelength.
The current filament which generates the scattered field is given by
dI=JdS=jω(ε-ε.sub.0)E dS.
The scattered field is given by
E.sup.S (x,y)=-(jk.sup.2 /4)ΣΣ(ε.sub.r -1)E(x',y')H.sub.0.sup.(2) (kρ)dx'dy'
where (x,y) and (x,y) are the coordinates of the observation point and the source point, ε r is the complex relative dielectric constant, ε/ε 0 .
The integral equation for the total field is then given by
E(x,y)+(jk.sup.2 /4)ΣΣ(ε.sub.r -1)E(x',y')H.sub.0.sup.(2) (kρ)dx'dy'=E.sup.i (x,y)
which can be solved numerically by point matching technique.
EXAMPLES
Several examples have been tested using the codes developed. They are: (1) cylindrical shell, (2) cylindrical half-shell, (3) a slab, and (4) three-wing structure. The echo width which represents the scattered field at infinity defined by
W(φ)=limit 2πρ.sub.0 |E.sup.S /E.sup.i |.sup.2
is plotted as a function of scattering angle φ.
Extension to Three Dimensions
Surface integral equation approach:
g(r,r')=exp(-jk|r-r'|)/4π|r-r'| ##EQU1##
The birefringence is measured just inside the fiber. The longer the wavelength, the larger percentage of the bulk of the object that is being read.
Computer Interpretation of Data
A computer program to solve Maxwell's equations in connection with the determination of birefringence of a fiber has been developed. Two dimensional scattering of the ion waves by the dielectric textile fibers of an arbitray cross-section involves integral equations which are solved numerically to determine the scattered field by the known scatterers. The scattering object is treated as a single hollow cylindrical fiber.
Basically the program solves the integral equations formed from Maxwell's formulations, describing the scattered laser beam. The deviration of the equations contained within the program are set forth in the reference field communication by Moment Methods by Roger F. Harrington, IEE Press, 1992. Initially, the program defines values that are known and/or Constance. The particular fiber for which the program is designed is a hollow fiber and accordingly, the shell width and the shell made ratios are defined. Importantly, the computer program can be extended to cover fibers of other shapes. Then, using the parameters initially defined, the integral equations for the incident electric field and scattering matrix are defined. The integral equations are solved in the do loops. A library sub-routine is used to invert the matrix. Descriptions of the library sub-routines employed in the program are attached behind the program. This computer program will be run with a wide variety of parameters to get results. Then the experimental data can be compared to the results to determine fiber properties. Another approach that can be taken is that instead of an integral equation approach, is an Eigen function approach, which is based on a different mathematical model which will give better results for a fiber having a circular cross-section. The integral equation approach will be best for trilobal shapes.
Trilobal Shapes
Often fibers are not cylindrical but can be trilobal. See FIG. 34. Importantly, trilobals have a size on the order of 20 microns to 2 millimeters. A CO 2 laser has a wavelength of approximately 10 microns which is on the order of the size of the trilobal. It may be desirable to use two lasers of different wavelengths or to provide one laser with different chopper frequencies, in order to accurately work with trilobal fibers.
Having thus described the invention in detail, it is to be understood that the foregoing description is not intended to limit the spirit and scope thereof What is desired to be protected by Letters Patent is set forth in the appended claims.
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A method and apparatus for measuring microstructures, anistropy and birefringence in polymers using laser scattered light includes a laser which provides a beam that can be conditioned and is directed at a fiber or film which causes the beam to scatter. Backscatter light is received and processed with detectors and beam splitters to obtain data. The data is directed to a computer where it is processed to obtain information about the fiber or film, such as the birefringence and diameter. This information provides a basis for modifications to the production process to enhance the process.
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BACKGROUND OF THE INVENTION
The application of lipases for hydrolyzing and/or modifying fats has been recognized for many years. More recently, lipolytic enzymes have been found to be suitable for industrial use. For example, lypolytic enzymes have been found to be useful for improving the milk flavor in certain dairy products. Lipases have also been used by the pharmaceutical industry for inclusion in digestive aids. Other industrial uses for lipolytic enzymes include interesterification of oils and fats, esterification of fatty acids, digestive aids in animal feeds and additives to washing and cleaning products. As a result of the increased acceptance of these applications, the demand for lipases is expected to grow rapidly in the future.
Lipases from animal, plant and microbial origin have been isolated and their properties have been studied extensively. These enzymes catalyze the hydrolysis of water soluble carboxylic acid esters (triglycerides) while the hydrolysis of water soluble carboxylic acid esters by lipase is very slow. The ability to catalyze the hydrolysis of insoluble long chain fatty acid esters thus distinguishes lipases from other esterases which catalyze hydrolysis of soluble esters in preference to insoluble esters.
Microbial lipase is conveniently produced by fermentation with microorganisms such as Aspergillus niger, Candida cylindracae, Mucor miehei, M. javanicus, Rhizopus delemar, R. arrhizus and Pseudomonas fluorescens which will secrete this enzyme through its cell wall. However, with many microorganisms capable of producing extracellular lipase, a substantial portion of the enzyme apparently remains attached to the cell wall. Sigima and Isobe, 1975, 1976 (Chemical and Pharmaceutical Bulletin, 23, p. 68, 1226 and 24, p. 72) have reported that microbial lipases show exceptionally high surface activity at air water and heptane water interfaces when compared to other groups of proteins. This high surface activity results in a strong adsorption of the lipase onto hydrophobic surfaces of the cell wall. This phenomenon has been observed in conjunction with microbial lipase secreted by a fungus of the species Mucor miehei.
In the case of fermentation of the fungal species Mucor miehei, more than 99% of the extracellular lipase produced is bound to the fungal mycelium while extracellular microbial rennet also produced by this organism is distributed freely in the fermentation broth. In U.S. Pat. No. 3,899,395 there is disclosed a method for recoverying microbial lipase from the fermentation growth product of a Mucor species which involves adsorbing the fermentation growth product with a material selected from diatomaceous earth or clay at a pH of from 4 to 6 and then eluting the lipolytic enzyme by adjusting the pH to a range of from 9 to 11.
SUMMARY OF THE INVENTION
The present invention is an improvement in the method of producing microbial lipase by the growth of a suitable microbial strain in a nutrient growth medium which results in the formation of microbial mycelium having lipase bound thereto. The improvement involves contacting an aqueous dispersion of the mycelium with an anhydride of an organic acid to thereby achieve separation of the mycelium and lipase.
DESCRIPTION OF THE INVENTION
In practicing this invention, the lipase secreting microorganism is grown in a suitable nutrient growth medium and the mycelium containing mycelial bound lipase is separated from the fermentation beer. Typically, the mycelium is separated from the culture filtrate by centrifugation and washed with deionized, distilled water. The mycelium is then resuspended in water and the pH adjusted to a level within the range of from 7 to 9, preferably 7.5 to 8.5, and ideally to 8.0 using 3N NaOH or KOH. The amount of acid anhydride employed will typically range from 0.2 to 0.6 g anhydride per 100 gm of mycelium on a dry weight basis. After stabilization of the pH, the suspension is further stirred for another hour and centrifuged. The clear supernatant is used for checking the lipase activity.
Lipase activity is determined by measuring butyric acid liberated from tributyrin substrate using a pH-stat under standard conditions, i.e. pH 6.2 at 42° C. One lipase unit (EW) is defined as the activity of enzyme which liberates one micromole of butyric acid per minute under the experimental conditions. ##EQU1##
The object of the present invention, derivatization of the cell bound enzyme, is accomplished by contacting the enzyme with an organic carboxylic acid anhydride. Any anhydride which will accomplish this goal may be used. Particularly suitable anhydrides are derived from acetic acid and organic dicarboxylic acids such as succinic, maleic and citraconic; succinic anhydride is preferred.
While the invention is not predicated on any particular theory or mechanism, it is believed that treatment of the mycelial bound lipase with an acid anhydride results in the substitution of cationic NH 3 + groups with anionic COO - groups thereby producing a net change of two charge units per each modified amino group. This increase in the electronegativity of the enzyme/protein destabilizes the stable mycelial/lipase complex resulting in the separation of the lipase and mycelium as indicated: ##EQU2##
Upon achieving this separation, the mycelium is separated from the aqueous phase by conventional solid/liquid separatory techniques whereupon the aqueous phase containing the lipase is processed further to provide the desired product. More particularly the mycelium is separated by centrifugation and the clear supernatant is further concentrated by vacuum evaporation.
In the following examples, fungal mycelium containing mycelial bound lipase was separated from the fermentation beer obtained from Mucor miehei. The microorganism was grown under aerobic conditions in a fermentation medium consisting of soy meal, starch and corn steep liquor at pH 6.1-6.5 and 32° C. for 3-4 days.
EXAMPLE I
Fungal mycelium (free from culture filtrate) obtained from 1000 ml of fermentation broth produced during the culturing of Mucor miehei was washed once with deionized distilled water. The washed mycelial cake was resuspended in water (1000 ml) and the pH was adjusted to 8.0 using 3N NaOH. Various amounts of succinic anhydride were added in small increments to 100 ml aliquots of the aqueous suspension of mycelium with constant stirring at 25° C. The pH was maintained between 7.5 and 8.0 with 3N NaOH during addition of the anhydride. After complete addition of the anhydride, the suspension was stirred for another hour and insolubles were separated by centrifugation at 15,000 rpm for 30 minutes at 5° C. The effect of succinic anhydride concentration on the release of lipase was determined by measuring the lipase activity. The drawing represents lipase activity as a function of succinic anhydride concentration.
Referring to the drawing, it can be determined that an aqueous extraction of fungal mycelium contained only 28 lipase units/ml. Addition of succinic anhydride during extraction of lipase at pH 8.0 caused a marked increase in the lipase activity. The lipase activity of the supernatant was increased with increasing concentration of succinic anhydride and reached a maximum of about 128 lipase units/ml (4.8× over the control). The marked increase in the lipase activity after succinylation of fungal mycelium could have been due to activation of lipase by succinylation as well as desorption of the enzyme from the fungal mycelium.
EXAMPLE II
Five hundred grams of washed mycelium were suspended in 500 ml of deionized distilled water and the pH was adjusted to 8.0 using 3N NaOH. The suspension was stirred for one hour and solubilized lipase was separated from the mycelium by centrifugation (15,000 rpm for 30 minutes at 5° C.). To the clear supernatant (50 ml containing 28 lipase units/ml) various amounts of succinic anhydride were added as described in Example I. After stabilization of the pH, the lipase activity was measured and is represented in Table 1.
TABLE 1______________________________________Effect of Succinylation of Lipaseon the Lipase ActivitySuccinic Anhydride Lipase ActivityAdded to 100 ml Aliquot EU/ml______________________________________0 28100 mg 35150 mg 52200 mg 68400 mg 60600 mg 50______________________________________
Succinylation of lipase alone increased the lipolytic activity by greater than 100%. Thus the observed marked increase in the lipase activity after derivatization of the fungal mycelium was not only due to the activation of the enzyme but also to the release of mycelial bound enzyme.
EXAMPLE III
One hundred milliliters of fungal mycelial suspension was adjusted to pH 8.0 using 3N NaOH. Various amounts of acetic anhydride were added and acetylation was carried out at pH 8.0 as described above. After stabilization of the pH, the suspension was centrifuged and the lipase activity of the supernatant was determined as indicated by Table 2.
TABLE 2______________________________________Effect of Acetylation of Fungal Myceliumon the Release of LipaseAmount of acetic anhydride Lipase activityper 100 ml fungal mycelium EU/ml______________________________________0 280.1 ml 200.3 ml 280.5 ml 380.7 ml 501.0 ml 30______________________________________
Acetylation of the fungal mycelium also caused the release of mycelial bound lipase. However, acetylation was found to be less effective than succinylation. The difference could be due to the marked increase in the electronegativity of the enzyme molecule by succinylation.
EXAMPLE IV
In another experiment, the pH of washed fungal mycelium (100 ml) was adjusted to 8.0 using 3N NaOH. Solid succinic anhydride (300 mg) was added in small increments with constant stirring while the pH was maintained between 7.5 and 8.5 using 3N NaOH. After the addition of succinic anhydride, the suspension was stirred for another hour at 25° C. and the lipase was separated by centrifugation at 15,000 rpm for 30 minutes at 5° C. The activity of the enzyme was measured at various pH's at 30° C. as described earlier. For comparison, the activity of lipase (control) extracted in the absence of succinic anhydride was also measured at different pH's as indicated in Table 3.
TABLE 3______________________________________Effect of pH on the Activity ofLipase and Succinylation Lipase % of Maximum ActivityAssay pH Lipase Succinylated Lipase______________________________________5.0 52 816.0 80 1006.5 90 987.0 100 947.5 95 848.0 80 709.0 60 39______________________________________
Lipase exhibited maximum activity at pH 7.0 and 30° C. However, succinylation of the lipase caused a shift in the pH for the maximum activity towards the acid side, i.e. pH 6.0. It is possible that the net increase in the electronegativity of the lipase molecule by succinylation may have increased the stability of the enzyme against acidic pH conditions.
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Disclosed is a method for causing the dissociation of microbial mycelium and extracellular lipase bound thereto and increasing the measurable activity of the lipase. The method involves treating an aqueous suspension of the mycelium with the anhydride of a dicarboxylic acid which results in dissociation of the mycelium and lipase thereby facilitating recovery of the lipase.
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TECHNICAL FIELD
This invention relates to conveyor lubricants and to a method for conveying articles. The invention also relates to conveyor systems and containers wholly or partially coated with such lubricant compositions.
BACKGROUND ART
In commercial container filling or packaging operations, the containers typically are moved by a conveying system at very high rates of speed. Copious amounts of aqueous dilute lubricant solutions (usually based on fatty acid amines) are typically applied to the conveyor or containers using spray or pumping equipment. These lubricant solutions permit high-speed operation of the conveyor and limit marring of the containers or labels, but also have some disadvantages. For example, aqueous conveyor lubricants based on fatty amines typically contain ingredients that can react with spilled carbonated beverages or other food or liquid components to form solid deposits. Formation of such deposits on a conveyor can change the lubricity of the conveyor and require shutdown to permit cleanup. Some aqueous conveyor lubricants are incompatible with thermoplastic beverage containers made of polyethylene terephthalate (PET) and other plastics, and can cause environmental stress cracking (crazing and cracking that occurs when the plastic polymer is under tension) in plastic containers. Dilute aqueous lubricants typically require use of large amounts of water on the conveying line, which must then be disposed of or recycled, and which causes an unduly wet environment near the conveyor line. Moreover, some aqueous lubricants can promote the growth of microbes.
SUMMARY OF THE INVENTION
The present invention provides, in one aspect, a method for lubricating the passage of a container along a conveyor comprising applying a mixture of a water-miscible silicone material and a water-miscible lubricant to at least a portion of the container-contacting surface of the conveyor or to at least a portion of the conveyor-contacting surface of the container.
The present invention provides, in another aspect, a lubricated conveyor or container, having a lubricant coating on a container-contacting surface of the conveyor or on a conveyor-contacting surface of the container, wherein the coating comprises a mixture of a water-miscible silicone material and a water-miscible lubricant.
The invention also provides conveyor lubricant compositions comprising a mixture of a water-miscible silicone material and a water-miscible lubricant.
The compositions used in the invention can be applied in relatively low amounts and do not require in-line dilution with significant amounts of water. The compositions of the invention provide thin, substantially non-dripping lubricating films. In contrast to dilute aqueous lubricants, the lubricants of the invention provide drier lubrication of the conveyors and containers, a cleaner and drier conveyor line and working area, and reduced lubricant usage, thereby reducing waste, cleanup and disposal problems.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 illustrates in partial cross-section a side view of a plastic beverage container and conveyor partially coated with a lubricant composition of the invention.
DETAILED DESCRIPTION
The invention provides a lubricant coating that reduces the coefficient of friction of coated conveyor parts and containers and thereby facilitates movement of containers along a conveyor line. The lubricant compositions used in the invention can optionally contain water or a hydrophilic diluent, as a component or components in the lubricant composition as sold or added just prior to use. The lubricant composition does not require in-line dilution with significant amounts of water, that is, it can be applied undiluted or with relatively modest dilution, e.g., at a water:lubricant ratio of about 1:1 to 5:1. In contrast, conventional dilute aqueous lubricants are applied using significant amounts of water, at dilution ratios of about 100:1 to 500:1. The lubricant compositions preferably provide a renewable coating that can be reapplied, if desired, to offset the effects of coating wear. They preferably can be applied while the conveyor is at rest or while it is moving, e.g., at the conveyor's normal operating speed. Preferably the lubricant coating is water-based cleaning agent-removable, that is, it preferably is sufficiently soluble or dispersible in water so that the coating can be removed from the container or conveyor using conventional aqueous cleaners, without the need for high pressure, mechanical abrasion or the use of aggressive cleaning chemicals. The lubricant coating preferably is substantially non-dripping, that is, preferably the majority of the lubricant remains on the container or conveyor following application until such time as the lubricant may be deliberately washed away.
The invention is further illustrated in FIG. 1, which shows a conveyor belt 10 , conveyor chute guides 12 , 14 and beverage container 16 in partial cross-sectional view. The container-contacting portions of belt 10 and chute guides 12 , 14 are coated with thin layers 18 , 20 and 22 of a lubricant composition of the invention. Container 16 is constructed of blow-molded PET, and has a threaded end 24 , side 25 , label 26 and base portion 27 . Base portion 27 has feet 28 , 29 and 30 , and crown portion (shown partially in phantom) 34 . Thin layers 36 , 37 and 38 of a lubricant composition of the invention cover the conveyor-contacting portions of container 16 on feet 28 , 29 and 30 , but not crown portion 34 . Thin layer 40 of a lubricant composition of the invention covers the conveyor-contacting portions of container 16 on label 26 .
The silicone material and hydrophilic lubricant are “water-miscible”, that is, they are sufficiently water-soluble or water-dispersible so that when added to water at the desired use level they form a stable solution, emulsion or suspension. The desired use level will vary according to the particular conveyor or container application, and according to the type of silicone and hydrophilic lubricant employed.
A variety of water-miscible silicone materials can be employed in the lubricant compositions, including silicone emulsions (such as emulsions formed from methyl(dimethyl), higher alkyl and aryl silicones; functionalized silicones such as chlorosilanes; amino-, methoxy-, epoxy- and vinyl-substituted siloxanes; and silanols). Suitable silicone emulsions include E2175 high viscosity polydimethylsiloxane (a 60% siloxane emulsion commercially available from Lambent Technologies, Inc.), E21456 FG food grade intermediate viscosity polydimethylsiloxane (a 35% siloxane emulsion commercially available from Lambent Technologies, Inc.), HV490 high molecular weight hydroxy-terminated dimethyl silicone (an anionic 30-60% siloxane emulsion commercially available from Dow Coming Corporation), SM2135 polydimethylsiloxane (a nonionic 50% siloxane emulsion commercially available from GE Silicones) and SM2167 polydimethylsiloxane (a cationic 50% siloxane emulsion commercially available from GE Silicones. Other water-miscible silicone materials include finely divided silicone powders such as the TOSPEARL™ series (commercially available from Toshiba Silicone Co. Ltd.); and silicone surfactants such as SWP30 anionic silicone surfactant, WAXWS-P nonionic silicone surfactant, QUATQ-400M cationic silicone surfactant and 703 specialty silicone surfactant (all commercially available from Lambent Technologies, Inc.). Preferred silicone emulsions typically contain from about 30 wt. % to about 70 wt. % water. Non-water-miscible silicone materials (e.g., non-water-soluble silicone fluids and non-water-dispersible silicone powders) can also be employed in the lubricant if combined with a suitable emulsifier (e.g., nonionic, anionic or cationic emulsifiers). For applications involving plastic containers (e.g., PET beverage bottles), care should be taken to avoid the use of emulsifiers or other surfactants that promote environmental stress cracking in plastic containers when evaluated using the PET Stress Crack Test set out below. Polydimethylsiloxane emulsions are preferred silicone materials. Preferably the lubricant composition is substantially free of surfactants aside from those that may be required to emulsify the silicone compound sufficiently to form the silicone emulsion.
A variety of water-miscible lubricants can be employed in the lubricant compositions, including hydroxy-containing compounds such as polyols (e.g., glycerol and propylene glycol); polyalkylene glycols (e.g., the CARBOWAX™ series of polyethylene and methoxypolyethylene glycols, commercially available from Union Carbide Corp.); linear copolymers of ethylene and propylene oxides (e.g., UCON™ 50-HB-100 water-soluble ethylene oxide:propylene oxide copolymer, commercially available from Union Carbide Corp.); and sorbitan esters (e.g., TWEEN™ series 20, 40, 60, 80 and 85 polyoxyethylene sorbitan monooleates and SPAN™ series 20, 80, 83 and 85 sorbitan esters, commercially available from ICI Surfactants). Other suitable water-miscible lubricants include phosphate esters, amines and their derivatives, and other commercially available water-miscible lubricants that will be familiar to those skilled in the art. Derivatives (e.g., partial esters or ethoxylates) of the above lubricants can also be employed. For applications involving plastic containers, care should be taken to avoid the use of water-miscible lubricants that might promote environmental stress cracking in plastic containers when evaluated using the PET Stress Crack Test set out below. Preferably the water-miscible lubricant is a polyol such as glycerol.
If water is employed in the lubricant compositions, preferably it is deionized water. Suitable hydrophilic diluents include alcohols such as isopropyl alcohol. For applications involving plastic containers, care should be taken to avoid the use of water or hydrophilic diluents containing contaminants that might promote environmental stress cracking in plastic containers when evaluated using the PET Stress Crack Test set out below.
Preferred amounts for the silicone material, hydrophilic lubricant and optional water or hydrophilic diluent are about 0.05 to about 12 wt. % of the silicone material (exclusive of any water or other hydrophilic diluent that may be present if the silicone material is, for example, a silicone emulsion), about 30 to about 99.95 wt. % of the hydrophilic lubricant, and 0 to about 69.95 wt. % of water or hydrophilic diluent. More preferably, the lubricant composition contains about 0.5 to about 8 wt. % of the silicone material, about 50 to about 90 wt. % of the hydrophilic lubricant, and about 2 to about 49.5 wt. % of water or hydrophilic diluent. Most preferably, the lubricant composition contains about 0.8 to about 4 wt. % of the silicone material, about 65 to about 85 wt. % of the hydrophilic lubricant, and about 11 to about 34.2 wt. % of water or hydrophilic diluent.
The lubricant compositions can contain additional components if desired. For example, the compositions can contain adjuvants such as conventional waterborne conveyor lubricants (e.g., fatty acid lubricants), antimicrobial agents, colorants, foam inhibitors or foam generators, cracking inhibitors (e.g., PET stress cracking inhibitors), viscosity modifiers, film forming materials, antioxidants or antistatic agents. The amounts and types of such additional components will be apparent to those skilled in the art.
For applications involving plastic containers, the lubricant compositions preferably have a total alkalinity equivalent to less than about 100 ppm CaCO 3 , more preferably less than about 50 ppm CaCO 3 , and most preferably less than about 30 ppm CaCO 3 , as measured in accordance with Standard Methods for the Examination of Water and Wastewater, 18 th Edition, Section 2320, Alkalinity.
The lubricant compositions preferably have a coefficient of friction (COF) that is less than about 0.14, more preferably less than about 0.1, when evaluated using the Short Track Conveyor Test described below.
A variety of kinds of conveyors and conveyor parts can be coated with the lubricant composition. Parts of the conveyor that support or guide or move the containers and thus are preferably coated with the lubricant composition include belts, chains, gates, chutes, sensors, and ramps having surfaces made of fabrics, metals, plastics, composites, or combinations of these materials.
The lubricant composition can also be applied to a wide variety of containers including beverage containers; food containers; household or commercial cleaning product containers; and containers for oils, antifreeze or other industrial fluids. The containers can be made of a wide variety of materials including glasses; plastics (e.g., polyolefins such as polyethylene and polypropylene; polystyrenes; polyesters such as PET and polyethylene naphthalate (PEN); polyamides, polycarbonates; and mixtures or copolymers thereof); metals (e.g., aluminum, tin or steel); papers (e.g., untreated, treated, waxed or other coated papers); ceramics; and laminates or composites of two or more of these materials (e.g., laminates of PET, PEN or mixtures thereof with another plastic material). The containers can have a variety of sizes and forms, including cartons (e.g., waxed cartons or TETRAPACK™ boxes), cans, bottles and the like. Although any desired portion of the container can be coated with the lubricant composition, the lubricant composition preferably is applied only to parts of the container that will come into contact with the conveyor or with other containers. Preferably, the lubricant composition is not applied to portions of thermoplastic containers that are prone to stress cracking. In a preferred embodiment of the invention, the lubricant composition is applied to the crystalline foot portion of a blow-molded, footed PET container (or to one or more portions of a conveyor that will contact such foot portion) without applying significant quantities of lubricant composition to the amorphous center base portion of the container. Also, the lubricant composition preferably is not applied to portions of a container that might later be gripped by a user holding the container, or, if so applied, is preferably removed from such portion prior to shipment and sale of the container. For some such applications the lubricant composition preferably is applied to the conveyor rather than to the container, in order to limit the extent to which the container might later become slippery in actual use.
The lubricant composition can be a liquid or semi-solid at the time of application. Preferably the lubricant composition is a liquid having a viscosity that will permit it to be pumped and readily applied to a conveyor or containers, and that will facilitate rapid film formation whether or not the conveyor is in motion. The lubricant composition can be formulated so that it exhibits shear thinning or other pseudo-plastic behavior, manifested by a higher viscosity (e.g., non-dripping behavior) when at rest, and a much lower viscosity when subjected to shear stresses such as those provided by pumping, spraying or brushing the lubricant composition. This behavior can be brought about by, for example, including appropriate types and amounts of thixotropic fillers (e.g., treated or untreated fumed silicas) or other rheology modifiers in the lubricant composition. The lubricant coating can be applied in a constant or intermittent fashion. Preferably, the lubricant coating is applied in an intermittent fashion in order to minimize the amount of applied lubricant composition. For example, the lubricant composition can be applied for a period of time during which at least one complete revolution of the conveyor takes place. Application of the lubricant composition can then be halted for a period of time (e.g., minutes or hours) and then resumed for a further period of time (e.g., one or more further conveyor revolutions). The lubricant coating should be sufficiently thick to provide the desired degree of lubrication, and sufficiently thin to permit economical operation and to discourage drip formation. The lubricant coating thickness preferably is maintained at at least about 0.0001 mm, more preferably about 0.001 to about 2 mm, and most preferably about 0.005 to about 0.5 mm.
Application of the lubricant composition can be carried out using any suitable technique including spraying, wiping, brushing, drip coating, roll coating, and other methods for application of a thin film. If desired, the lubricant composition can be applied using spray equipment designed for the application of conventional aqueous conveyor lubricants, modified as need be to suit the substantially lower application rates and preferred non-dripping coating characteristics of the lubricant compositions used in the invention. For example, the spray nozzles of a conventional beverage container lube line can be replaced with smaller spray nozzles or with brushes, or the metering pump can be altered to reduce the metering rate.
The lubricant compositions can if desired be evaluated using a Short Track Conveyor Test and a PET Stress Crack Test.
Short Track Conveyor Test
A conveyor system employing a motor-driven 83 mm wide by 6.1 meter long REXNORD™ LF polyacetal thermoplastic conveyor belt is operated at a belt speed of 30.48 meters/minute. Six 2-liter filled PET beverage bottles are stacked in an open-bottomed rack and allowed to rest on the moving belt. The total weight of the rack and bottles is 16.15 Kg. The rack is held in position on the belt by a wire affixed to a stationary strain gauge. The force exerted on the strain gauge during belt operation is recorded using a computer. A thin, even coat of the lubricant composition is applied to the surface of the belt using an applicator made from a conventional bottle wash brush. The belt is allowed to run for 25 to 90 minutes during which time a consistently low COF is observed. The COF is calculated on the basis of the measured force and the mass of the bottles, averaged over the run duration.
PET Stress Crack Test
Standard 2-liter PET beverage bottles (commercially available from Constar International) are charged with 1850 g of chilled water, 31.0 g of sodium bicarbonate and 31.0 g of citric acid. The charged bottle is capped, rinsed with deionized water and set on clean paper towels overnight. The bottoms of 12 bottles are dipped in a 200 g sample of the undiluted lube in a 125×65 mm crystal dish, then placed in a bin and stored in an environmental chamber at 37.8° C., 90% relative humidity for 14 days. The bottles are removed from the chamber, observed for crazes, creases and crack patterns on the bottom. The aged bottles are compared with 12 control bottles that were exposed to a standard dilute aqueous lubricant (LUBODRIVE™ RX, commercially available from Ecolab) prepared as follows. A 1.7 wt. % solution of the LUBODRIVE lubricant (in water containing 43 ppm alkalinity as CaCO 3 ) was foamed for several minutes using a mixer. The foam was transferred to a lined bin and the control bottles were dipped in the foam. The bottles were then aged in the environmental chamber as outlined above.
The invention can be better understood by reviewing the following examples. The examples are for illustration purposes only, and do not limit the scope of the invention.
EXAMPLE 1
77.2 parts of a 96 wt. % glycerol solution, 20.7 parts deionized water, and 2.1 parts E2175 high viscosity polydimethylsiloxane (60% siloxane emulsion commercially available from Lambent Technologies, Inc.) were combined with stirring until a uniform mixture was obtained. The resulting lubricant composition was slippery to the touch and readily could be rinsed from surfaces using a plain water wash. Using the Short Track Conveyor Test, about 20 g of the lubricant composition was applied to the moving belt over a 90 minute period. The observed COF was 0.062. In a comparison Short Track Conveyor test performed using a dilute aqueous solution of a standard conveyor lubricant (LUBODRIVE™ RX, commercially available from Ecolab, applied using a 0.5% dilution in water and about an 8 liter/hour spray application rate), the observed COF was 0.126, thus indicating that the lubricant composition of the invention provided reduced sliding friction.
The lubricant composition of Example 1 was also evaluated using the PET Stress Crack Test. The aged bottles exhibited infrequent small, shallow crazing marks. For the comparison dilute aqueous lubricant, frequent medium depth crazing marks and infrequent deeper crazing marks were observed. No bottles leaked or burst for either lubricant, but the bottoms of bottles lubricated with a lubricant composition of the invention had a better visual appearance after aging.
EXAMPLE 2
Using the method of Example 1, 77.2 parts of a 96 wt. % glycerol solution, 20.7 parts deionized water, and 2.1 parts HV490 high molecular weight hydroxy-terminated dimethyl silicone (anionic 30-60% siloxane emulsion commercially available from Dow Coming Corporation) were combined with stirring until a uniform mixture was obtained. The resulting lubricant composition was slippery to the touch and readily could be rinsed from surfaces using a plain water wash. Using the Short Track Conveyor Test, about 20 g of the lubricant composition was applied to the moving belt over a 15 minute period. The observed COF was 0.058.
EXAMPLE 3
Using the method of Example 1, 75.7 parts of a 96 wt. % glycerol solution, 20.3 parts deionized water, 2.0 parts HV490 high molecular weight hydroxy-terminated dimethyl silicone (anionic 30-60% siloxane emulsion commercially available from Dow Corning Corporation) and 2.0 parts GLUCOPON™ 220 alkyl polyglycoside surfactant (commercially available from Henkel Corporation) were combined with stirring until a uniform mixture was obtained. The resulting lubricant composition was slippery to the touch and readily could be rinsed from surfaces using a plain water wash. Using the Short Track Conveyor Test, about 20 g of the lubricant composition was applied to the moving belt over a 15 minute period. The observed COF was 0.071.
EXAMPLE 4
Using the method of Example 1, 72.7 parts of a 99.5 wt. % glycerol solution, 23.3 parts deionized water, 2 parts HV495 silicone emulsion (commercially available from Dow Corning Corporation) and 2 parts GLUCOPON™ 220 alkyl polyglycoside surfactant (commercially available from Henkel Corporation) were combined with stirring until a uniform mixture was obtained. The resulting lubricant composition was slippery to the touch and readily could be rinsed from surfaces using a plain water wash. However, the presence of the surfactant caused an increase in stress cracking in the PET Stress Crack Test.
Various modifications and alterations of this invention will be apparent to those skilled in the art without departing from the scope and spirit of the invention, and are intended to be within the scope of the following claims.
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The passage of a container along a conveyor is lubricated by applying to the container or conveyor a mixture of a water-miscible silicone material and a water-miscible lubricant. The mixture can be applied in relatively low amounts and with relatively low or no water content, to provide thin, substantially non-dripping lubricating films. In contrast to dilute aqueous lubricants, the lubricants of the invention provide drier lubrication of the conveyors and containers, a cleaner conveyor line and reduced lubricant usage, thereby reducing waste, cleanup and disposal problems.
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This invention relates to a thin application of a humectant onto the inner surface of a container for an aqueous slurry, such as a drywall joint compound, prior to filling the container with the aqueous slurry.
BACKGROUND OF THE INVENTION
Drywall joint compounds are sold in a dry powder form to be mixed with water by the user just prior to use, and also in ready-mixed aqueous slurry form, requiring only a minimum of preparation by the user prior to use. A problem exists in packaging the ready-mixed joint compounds in that portions of the ready-mixed compound which are in contact with the inner surface of a package tend to give up part of the water, which alters the character of that drier part of the joint compound.
One form of packaging of ready-mixed joint compounds involves inserting a polyethylene film bag into a substantially cubic corrugated cardboard box, sleeving the top of the bag by folding it back onto the outside of the box, and squirting the container full of ready-mixed joint compound, commonly referred to as "ready-mix". The top of the polyethylene bag is then closed and a wire tie keeps the bag airtight. Flaps, forming the cardboard box top are then folded down over the bag, and the box is sealed shut.
In filling the polyethylene bag and closing it, small amounts of the ready-mix will commonly become spattered or otherwise stuck onto an upper portion of the bag that is folded over the top of the ready-mix, but not in complete contact with the ready-mix. These small amounts tend to dry out prior to the ultimate user opening the box, and when the ultimate user then opens the box and the polyethylene bag, these dried out small amounts become loosened and fall into the ready-mix, contaminating the ready-mix to an even greater extent than the somewhat dried parts of the main body of the ready-mix which are in contact with the inner surface of the package.
SUMMARY OF THE INVENTION
The present invention consists of a method wherein a humectant, such as glycol, is sprayed onto the inner surface of a container for aqueous slurries such as ready-mix joint compounds, and to an improved container for aqueous slurries which have a thin coating of a humectant on the container inner surface.
It is an object of the present invention to provide an improved package for aqueous slurries wherein a thin coating of humectant is disposed on the entire inner surface of the package which is subject to coming into contact with the aqueous slurry.
It is a further object of the invention to provide a filled and sealed package of ready-mix joint compound consisting of a package which has a humectant on the surface of the package which is in contact with the joint compound.
It is a still further object of the invention to provide a novel method of preparing a package for use in the containment of aqueous slurries, and of preparing improved filled packages of ready-mix joint compound.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects and advantages of the invention will be more readily apparent when considered in relation to the preferred embodiments as set forth in the specification and shown in the drawings in which:
FIG. 1 is an isometric view of a corrugated cardboard box with a polyethylene film bag inserted therein, being sprayed with a humectant, prior to the bag being filled with ready-mix joint compound.
FIG. 2 is a sectional end view of a corrugated cardboard box with a polyethylene film bag therein, internally coated with a humectant and filled almost to the closed top of the bag with ready-mix joint compound.
FIG. 3, is a flow diagram of the complete apparatus for spraying humectant, as partially shown in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, there is shown a corrugated cardboard box 10, about 10"×10"×10", having a bottom 12, four sides 14 and top flaps 16 suitable for closing and sealing the box 10. Box 10, as shown, is located on a roller conveyor 18. Inserted into box 10 is a polyethylene film bag 20, a major lower portion 22 being within box 10, generally conforming to the inner shape of box 10, whereby the box 10 functions as a relatively rigid outer shell for supporting the bag 20 and any material placed therein. A minor upper portion 24 of bag 20 is outside box 10, folded outwardly and downwardly over flaps 16, whereby the lower portion 22 of bag 20 is held in an open and accessible condition, thoroughly exposing the entire inner surface 26 of the lower portion 22 of bag 20, through the top opening 28.
In accordance with the preferred form of the invention, a liquid spray gun 30 with a downwardly directed spherical spray pattern tip 32 is shown disposed in top opening 28, just inside the lower portion 22 of bag 20, with a large plurality of droplets 34 of humectant being sprayed onto the entire inner surface of the bag lower portion 22. The spherical tip 32 has a large plurality of openings 36, directing said humectant droplets 34 horizontally in all horizontal directions and downwardly in all downwardly directions and outwardly in all directions therebetween, in order to apply a continuous thin humectant coating 38 throughout the inner surface 26 of the lower portion 22 of bag 20.
This spray application of a humectant coating 38, onto the inner surface 26, is preferably performed immediately after the bag 20 is inserted into the box 10, as the bag 20 and box 10 are progressing along a conveyor 18, prior to placing an aqueous slurry 40 into the lower portion 22 of the bag 20. Means, not shown, are provided to move the spray gun 30 downwardly to a spraying position and then upwardly to permit the box 10 to be moved along the conveyor 18.
FIG. 2 shows box 10, still disposed on roller conveyor 18, after the bag 20 has had a body 42 of ready-mix joint compound aqueous slurry 40 placed therein, and the bag upper portion 24 has been gathered tightly together and sealed with a wire tie 44. The thin bag 20 and the extremely thin humectant coating 38 are shown in exaggerated thicknesses in FIG. 2. Also shown in FIG. 2 are a few small globs 46 of joint compound slurry 40 that splashed on the inner surface 26 of lower portion 22 above the part of inner surface 26 in contact with the main body 40 of joint compound slurry 42.
The presence of the humectant coating 38 on the inner surface 26 of the lower portion 22 of bag 20, throughout all areas of contact between bag 20 and joint compound slurry 40, reduces very substantially any decrease in the water content of those portions of the main body 42 of aqueous slurry 40 located near the inner surface 26 and of the globs 46 of aqueous slurry 40 stuck on the inner surface 26.
FIGS. 1 and 3 show, pictorially and diagrammatically, respectively, the apparatus for producing the large plurality of droplets 34. A pressure pot 50 is filled with humectant and air is constantly supplied through the air inlet 52 in the pressure pot lid 54. A pressure control regulator 56 on the air inlet 52 maintains a constant air pressure of about 25 psi in the pressure pot 50.
A dip tube 58 extends from near the bottom of the pressure pot 50 up through the lid 54 and to the humectant inlet 60 of spray gun 30. Spray gun 30 is preferably a Paasche A-JU automatic spray gun, manufactured by Paasche Airbrush Company. Spray gun 30, in addition to humectant inlet 60, has an atomizing air inlet 62 and an actuating air inlet 64. At the lower part of spray gun 30 is an extension pipe 65, onto which spray pattern tip 32 is screwed.
On the upper end of spray gun 30 is a fluid adjusting nut 66 with settings from zero to 90. The fluid adjusting nut 66 controls the stroke of a needle (not shown) which thus regulates the flow of the material through the spherical tip 32. Air is constantly supplied, through a regulator and pressure gauge 67, at about 25 psi, to the atomizing air inlet 62.
Air at about 50 psi is supplied to the actuating air inlet 64, in very short bursts, the length of time of each burst being very closely controlled by a signal timer 68, preferably an Eagle Signal Programmable Digital Timer, LX 240 Series, capable of controlling the duration of a burst of air to tenths of seconds. The signal timer 68, operating from a 110 V. power line 69, actuates a solenoid valve 70, which, when opened, allows 50 psi air from a source 72 to proceed to the actuating air inlet 64. A pressure regulator 73, an air pressure gauge 74 and a manual valve 76 are also shown between the high pressure air source 72 and the solenoid valve 70.
The amount of humectant sprayed into each bag 20 is controlled by both the timer 68 and the fluid adjusting nut 66 which controls the stroke of the needle (not shown). In the preferred form, about 5 grams, or from about 2 to 10 grams, of ethylene glycol per bag 20 is used; bag 20 is constructed to contain about three-and-a-half gallons of slurry 40 in the lower portion 22, and the spraying of the glycol takes about one or two seconds.
The preferred humectants are glycols, such as ethylene glycol or a mixture of ethylene glycol with a minor amount of water. Also, diethylene glycol or a propylene glycol, when substituted for the ethylene glycol in a pure form or mixed with water, have been found to be suitable in accordance with the invention.
When the box 10, filled with aqueous joint compound slurry 40, is delivered to a customer, the customer will be able to empty the contents more easily and completely than a similar box not treated with a coating of humectant in the bag 20, and the joint compound slurry 40 will be of a more uniform condition, relatively free of dried out or partially dried out portions or globs.
Having completed a detailed description of the preferred embodiments of our invention so that those skilled in the art may practice the same, we contemplate that variations may be made without departing from the essence of the invention.
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Ready-mix joint compound packaged in a container, the inner surface of which has a thin coating of humectant, such as a glycol, maintaining an improved uniformity of the moisture content of all portions of the ready-mix joint compound contained therein.
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This a continuation of application Ser. No. 494,965 filed May 16, 1983 now abandoned which is a continuation of application Ser. No. 436,153 filed Oct. 22, 1982 now abandoned, which is a continuation of application Ser. No. 293,948 filed Aug. 18, 1981 now abandoned, which is a continuation-in-part of application Ser. No. 203,984 filed Nov. 4, 1980, now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to a felt conditioning system having particular application to papermaking machinery in which travelling felts absorb water from a paper or board sheet being formed by the machine. In order to assure efficient machine operation it is necessary to dewater the felt and remove other materials picked up by the felt from the paper web such as loose fibers, clays, etc.
In the press section of a papermaking machine top and bottom endless press felts are used to remove water from a paper or board sheet being formed. For proper functioning of the endless felts it is necessary to remove all water absorbed by the felt in each revolution otherwise the felt becomes supersaturated. It is particularly important to remove absorbed water from the felt before it reaches the press nip so that the felt is properly conditioned, i.e., water has been removed to enable the felt to absorb the maximum quantity of water from the paper sheet. In conventional practice it is common to see a paper machine operating with a wet nip, i.e., a back flow of water to the incoming side of the press nip--a clear indication that the felt is supersaturated. A wet nip occurs because the felt conditioning suction boxes are not removing the quantity of water taken up by the felt for each felt cycle. A supersaturated felt travelling at 3000 fpm encounters high hydraulic forces at the press nip causing removal of fines from the paper sheet and requiring reduction in nip pressure to avoid hydraulic forces which would destroy the sheet. Of course, with reduced nip pressure less water is removed from the sheet.
Accordingly, conventional techniques for conditioning felts on operating paper machines have inherent limitations so that press felts are not properly dried.
In felt conditioning with suction boxes a saturated felt passes over a vacuum opening or slot extending across the machine beneath the felt. At machine speeds of 3000 fpm any point in the felt has a dwell time of 1.6 milliseconds over a 1-inch vacuum slot. As machine speed increases the dwell time grows shorter limiting the volume of water that can be drawn by vacuum through the slot. Moreover, removal of water from a travelling felt into a suction box requires the force of air drawn through the felt to deflect each droplet of water moving with the felt at machine speed. As machine speed increases greater air force is required to remove water from the felt. To overcome these limitations and to achieve increased water removal at greater machine speeds one may use more than one suction slot, however, the cost for this improvement is reduced felt life.
In practice, suction boxes are applied to the paper sheet side of the felt because the dirt to be removed is located toward that side of the felt. The suction boxes then wear the nap of the felt and diminish the ability of the felt to absorb water. Suction boxes are also applied to a horizontal run of the top felt after the paper side of the felt has passed over an outside roll which presses the dirt into the felt before reaching the suction box.
Another technique for felt conditioning is the honeycomb roll described in U.S. Pat. No. 4,116,762 to Gardiner. According to Gardiner the felt passes over a rotating honeycomb roll while conditioning air moves through the foraminous structure of the rotating roll and through the felt. Since the honeycomb roll rotates, the conditioning air is supplied to a stationary plenum within the roll in an axial direction from both ends of the roll. Supplying air through the roll in an axial direction is not feasible because extremely high air velocities are required in order to move the necessary volume of air through the felt for conditioning. High velocity air loses pressure as it moves through the axial supply tubes with resultant loss of air temperature and volume and diminished ability for conditioning the felt. The diameter of the honeycomb roll cannot be increased to achieve greater conditioning air volume with lower air velocities because the maximum pressure of conditioning air is inversely proportional to the radius of curvature of the felt passing over the roll at a gigven felt tension. As a result any increase in honeycomb roll diameter requires lower conditioning air pressures to avoid lifting the felt away from the honeycomb roll surface.
Felt manufacturers recommend a minimum flow of conditioning air for the honeycomb roll of 6 cubic feet per minute per square inch of felt or approximately 100 cfm per inch of felt width. For a 300-inch wide felt 30,000 cfm of conditioning air is required at velocities approaching 25,000 fpm. As the conditioning air expands through a honeycomb roll under these conditions its temperature drops to the point of freezing the water carried by the felt. In addition, water viscosity increases as temperature decreases inhibiting its removal from the felt.
A further limitation of the honeycomb roll inheres in the nature of the honeycomb roll itself. As the moving felt engages the surface of the honeycomb roll, a pocket of ambient air is trapped in the cells defined by the honeycomb structure between the felt and the pressurized plenum within the roll. Felt conditioning air in the interior plenum chamber of the honeycomb roll therefore must first compress the trapped ambient air before passing through the felt. In addition, the trapped ambient air will lower the temperature of hot conditioning air. As a result of this limitation, time is lost and the effectiveness of the conditioning air is diminished. It is not likely that these air pockets can be eliminated since the honeycomb structure requires a given depth of lattice work to achieve roll strength sufficient to support the felt under tension. In addition with the current industry trend to wider machines the honeycomb structure must have greater radial dimensions to meet strength requirements. Accordingly, the honeycomb roll is limited in utility for purposes of felt conditioning by passing pressurized air through the felt and has not been commercially used in the papermaking industry.
Another felt conditioning device is disclosed in U.S. Pat. No. 3,347,740 to Goumeniouk. This device utilizes either a rotating or a stationary tube member for supplying air under pressure to fill the voids created in a travelling felt as it expels water under the influence of centrifugal force. In order to generate sufficient centrifugal force for water removal, a very small diameter tube or roll is required. Accordingly, for reasons elaborated above, felt conditioning by use of centrifugal force and by moving air through the felt are physically incompatible techniques and cannot be used together with advantage.
SUMMARY OF THE INVENTION
The present invention is directed to a felt conditioning system in which air under pressure is delivered to a felt for removal of water and trapped substances such as paper fibers, clay, and the like accumulated in the felt in the course of removing water from a paper or board web being formed.
According to the invention a stationary air supply plenum chamber is located at the back side of the felt for delivering conditioning air to the felt. The air outlet from the chamber is fitted with a plurality of support ribs for engaging and spreading the back side of the travelling felt as conditioning air flows in a radial direction through the felt. Preferably, hot air from a convenient source such as the final dryer section of the machine is compressed and delivered to the air plenum chamber as pressurized conditioning air. The interior of the plenum is fitted with vanes for directing conditioning air radially toward the felt. In the system there is only minor loss of air temperature and there is negligible pressure differential before heated and pressurized air passes through the felt for removing water. The hot air reduces water viscosity which facilitates water removal from the felt.
In a preferred form of the invention the felt supporting ribs may be arranged in a "herringbone" pattern", i.e., at an acute angle to the machine direction in order to spread the felt as it is being conditioned. According to the invention the arcuate supporting ribs have a relatively small radius of curvature and therefore are able to take advantage of centrifugal force as an aid in water removal it being understood that centrifugal force only aids in removing saturation water from the felt thereafter being of negligible value.
As felts continue in operation, they accumulate dirt which reduces felt permeability and it is therefore necessary to reduce the volume of air delivered to the felt to avoid increasing air pressure which would lift the felt away from the supporting ribs of the air supply plenum. According to the present invention, the volume of conditioning air passing through the felt is adjusted by monitoring plenum air pressure and felt tension.
OBJECTS OF THE INVENTION
An object of the invention is to provide a felt conditioning system for a paper machine which removes the water absorbed by the felt each operating cycle so that the machine operates with a dry nip at the press rolls and with higher nip pressure.
Another object of the invention is to provide a felt conditioning system which engages the back side of the felt and does not wear the paperside nap of the felt.
Another object of the invention is to provide a felt conditioning system which effectively provides a sufficient volume of heated air for removing water and dirt from the felt.
Another object of the invention is to provide a felt conditioning system which spreads the felt in a cross machine direction to promote removal of water and dirt.
Another object of the invention is to provide means for adjusting the volumetric flow of conditioning air at constant pressure in order to maintain substantially constant felt tension.
Other and further objects of the invention will occur to one skilled in the art in practicing the invention or will be understood from the following detailed description.
DETAILED DESCRIPTION OF THE INVENTION
A preferred embodiment of the invention has been chosen for illustrating and describing its principles and is shown in the accompanying drawing in which:
FIG. 1 is a schematic view of a press section of a papermaking machine in which the felt conditioning system of the invention is installed.
FIG. 2 is a detailed schematic view of a felt conditioning system of the invention installed in the press section of a papermaking machine.
FIG. 3 is a front elevation of a felt conditioning air plenum chamber according to the invention.
FIG. 4 is a section view of the plenum taken along line 4--4 of FIG. 3.
FIG. 5 is a fragmentary top plan view of the center section of the plenum illustrating the felt support ribs.
FIG. 6 is a schematic view illustrating the means for maintaining substantially constant tension in the machine felt and substantially constant air pressure in the conditioning air plenum chamber.
FIG. 7 is a fragmentary perspective view of a modified plenum according to the invention.
FIG. 8 is a section view of the plenum of FIG. 7.
FIG. 9 is a side elevational view of a modified plenum according to the invention.
FIG. 10 is a section view taken along line 10--10 of FIG. 9.
Referring now to the drawing and in particular to FIG. 1, I have illustrated the press section 10 of a papermaking machine including an unsupported board sheet web W passing through the nip of cooperating press rolls 14, 16 along with endless felts 18, 20 which remove water and a residue of fibers, clay, etc. from the board sheet. Each felt is supported over a plurality of felt rolls 22, and guiding rolls 24 and passes a felt conditioning station 26 having the felt conditioning system 28 of the present invention. A save all collection pan 30 collects and drains water and dirt removed from the felt at each felt conditioning station. It is to be understood that only one felt conditioning system is needed for each press felt. The felt conditioning stations shown in FIG. 1 are typical however they may be located at any accessible point of travel. A shower 29 for flooding the felt is located upstream of each felt conditioning station.
Referring now to FIGS. 2 to 5 the felt conditioning system according to the invention comprises a plenum chamber 32 in the form of a box-like structure with top 34, front 36, rear 38, and end 40, 42 walls joined in any suitable air tight manner. An air supply header 44 is preferably located in one of the end walls as shown in FIGS. 2 and 3. Air directing vanes 46 are positioned within the plenum between the front 36 and rear 38 walls for the purposes of directing the conditioning air in a radial direction toward and through the felt. If desired an air supply header may be located in each end wall of the plenum chamber and in this case air directing vanes cooperate with each header to divert conditioning air radially toward the felt.
As shown in FIGS. 3-5, the felt conditioning plenum includes an open end 48 defined by a plurality of ribs 50 extending along a predetermined radius of curvature from the front wall 36 to the rear wall 38 of the plenum. The ribs are preferably fabricated of steel rods having a circular cross section to achieve minimal frictional contact with the felt and to minimize the area of felt obscured by the ribs during the felt conditioning operation. Each rib is secured at its front and rear terminal portions 52 and 53 to front and rear plenum walls. A metal shield 54 covers the front and rear terminal portions of the ribs 50 to prevent abrasion of the felt. Spaced stiffening bars 56 support and maintain desired spacing between the adjacent ribs.
In order to aid spreading of the felt during the conditioning operation, the support ribs are oriented away from the machine center line at an acute angle in the machine direction. Therefore as the felt moves over the angled support ribs in the direction indicated by the arrow in FIGS. 4 and 5, the felt spreads in the cross machine direction to open its interstices to allow more efficient water removal by the conditioning air. In order to provide uniform air flow to all sections of the felt, I prefer orienting the support ribs so that the rear terminal portion 53 of each rib is displaced in the cross machine direction from its forward terminal portion 52 a distance approximately twice its cross sectional diameter.
This preferred relationship is shown best in FIG. 5 where arrow A represents the machine direction and where the front terminal portion 52 of rib 50 is displaced two diameters 2d in the cross machine direction from its terminal portion 53. This spacing and orientation of the ribs is essential to attaining the uniform open area of the felt in the cross machine direction.
For felt conditioning, a press felt laden with water and dirt received from the board web and from felt saturating showers is trained over the open end of the conditioning plenum. As described, the support rods being divergent in the direction of felt travel spread the felt in the cross machine direction opening its interstices to the purging action of the conditioning air. Heated air preferably taken from the final dryer section of the machine is compressed and introduced through air inlet 44 into the plenum chamber 28 thereafter passing radially through the felt for removing water and dirt as shown by arrows in FIGS. 3 and 4.
For ease of fabrication the supporting ribs forming the open end of the air plenum chamber may be formed of a stainless steel plate rolled to the desired radius of curvature with the supporting ribs formed by cutting slots in the rolled plate. The ribs formed in this manner have their lateral edges machined so that each rib has a curved surface in engagement with the travelling felt. In this form of the invention the ribs are also oriented in a divergent manner with the forward terminal portion of the rib spaced twice its effective cross sectional diameter from its rear terminal portion in the cross machine direction.
It should be pointed out that the outer edges of the plenum open end are provided with sealing strips 58, 60 which engage the lateral edges of the felt to prevent lateral escape of air from the plenum.
In FIGS. 7 and 8, I illustrate a modified form of plenum chamber 80 with side walls 82, 84 having a generally egg shaped cross section characterized by an open end 86 having a small radius of curvature r and an enclosed rear section 88 having a large radius of curvature R. By this plenum chamber construction the felt F as it moves over the open end conforms to the small radius r so that, the felt tension T is kept at a minimum value for a given air pressure. Therefore, the full advantages of the invention are achieved by directing the felt over as small a radius as possible with full flow of air at a given pressure through the felt without the necessity of increasing felt tension. To provide an air seal I prefer to begin felt contact with the plenum chamber a small distance, say 2 inches, before point a and end felt contact a similar distance past point b in FIGS. 7 and 8.
In practice, an egg shaped plenum 80 may have an open end 86 defined by a small radius of curvature r of between 2 and 5 and preferably 3 to 31/2 inches with an opening of 3 to 12 and preferably 3 to 31/2 inches along the curvature α between points a and b. The rear section 88 of the plenum chamber has a larger radius of curvature R of between 6 and 14 inches to provide a plenum of sufficient volume to accommodate the volume of air required for purging the felt. Air flow may enter the plenum through a suitable end opening as in the embodiment of FIG. 3. The outer surfaces of side walls are curved for rigidity. The open end of the egg shaped plenum chamber is fitted with a plurality of ribs 50 in the same arrangement as FIG. 5. The plenum sidewalls 82, 84 extend the full width of the machine as with FIG. 3. With a plenum chamber in these ranges of dimensions and having an air pressure of between 3 to 10 psig, preferably 3 to 7 PSIG and a temperature between 40° and 120° F. I achieve an air flow through the felt of 7 to 25 cfm per square inch of air opening at open end of plenum chamber. This air flow range is sufficient to purge water from felts of 20 to 120 inches (water gauge) permeability. Additionally, this air flow range and felt purging is achieved regardless of machine speed, a major advantage of the present invention.
In FIGS. 9 and 10 I illustrate a further modification of the present invention comprising an egg shaped plenum 80 of FIGS. 7 and 8 with a tapered air supply duct 90 furnishing purging air through an opening 92 extending the full length of the large end of the plenum.
The maximum pressure of conditioning air is a function of felt tension and radius of curvature of the conditioning zone. With a given radius of curvature, it is necessary to maintain felt tension at a known value so that conditioning air has sufficient pressure for effective cleaning of the felt. For proper operation, the tension in the felt is greater than the product of the plenum air pressure in pounds per linear inch times the radius of curvature inches of the plenum open end. As a new felt is being used it tends to stretch or creep and it is necessary to take up the slack to maintain constant felt tension. Accordingly I provide an Emery load cell 62 (FIG. 6) or a strain gauge at a felt roll 22 journal to detect any change in felt tension. The load cell cooperates with a movable stretch roll 64 through an actuating diaphragm 66 to restore desired felt tension. As shown in FIG. 6, load cell 62 detects felt tension and signals a differential pot 68 which compares the signal to a reference value for felt tension. If the felt tension is below a desired value, the differential pot will actuate an air valve 70 admitting compressed air to the diaphragm 66 which moves slidably mounted stretch roll 64 to restore the tension of felt 20 to the desired value. A bleed valve 72 allows for reducing diaphragm pressure should it be necessary to reduce felt tension in an operating emergency.
A press felt normally accumulates embedded dirt in the course of its useful life which cannot be removed resulting in decreased permeability of the felt to conditioning air. Accordingly, as a felt ages the pressure of a given volume of conditioning air through the felt increases tending to lift the felt off the supporting ribs so that conditioning air vents at the edges of the felt without passing through it. This being the case it is necessary to provide means for maintaining the same conditioning air pressure and for reducing the volume of air flow through the felt as it ages. As shown in FIG. 6, a pressure transducer 74 in air plenum 28 detects variations in air pressure in the air supply plenum chamber. The pressure transducer signal is compared by the differential pot 68 to a standard value for plenum air pressure. If the signal exceeds a predetermined increment, the differential pot will open or close a damper valve 76 in the plenum air supply system 78 to change the volume of air entering the air supply plenum at constant pressure. In this manner there is no air pressure build up in the plenum chamber as the felt loses permeability. It should be observed that permeability of new felts varies and the foregoing system may be adjusted for desired values of felt tension and plenum air pressure.
In operation, the felt conditioning system according to the invention is applied to each felt used in the press section of a papermaking machine. Each felt emerges from the press nip laden with water absorbed from the paper sheet and carrying dirt picked up from the sheet. As the felt approaches the felt conditioning station it is flooded with a shower to prepare it for purging. The felt then passes over the air purging plenum opening through a predetermined radius of curvature with the backside of the felt engaging diverging ribs which spread the felt and open it to purging action of the conditioning air for removing water and dirt. Air pressure (gauge) in the plenum chamber may be in the range from 3 to 15 inches of Mercury and preferably is 7 to 8 inches of Mercury. Air under pressure and at elevated temperature flows through the plenum chamber in a radial direction and through the felt to condition it. Water removal is aided by centrifugal force developed in the felt as it traverses the conditioning station at high velocity. A felt conditioning system having a four inch radius of curvature at the conditioning zone provides considerable operating advantages over a conventional suction box having a one inch wide suction slot. The felt conditioning system provides a ten-fold increase in felt dwell time in the conditioning zone permitting much more effective purging of the felt. The system also eliminates the need for expensive vacuum pump and the approximately 100,000 gallons of seal water required by a vacuum pump in a suction box system. Tension in the felt is maintained at a constant value by means a load cell cooperating with a diaphragm operated tension roll which adjusts for creep occurring in the felt through continuous use. Moreover, to adjust for gradual loss of permeability as the felt ages I provide a pressure monitorring system to sense build up of air pressure in the conditioning air plenum chamber with decreasing felt permeability. As this occurs, the volume of air flow into the plenum chamber is decreased. In this manner I achieve maximum conditioning air pressure for a constant felt tension.
From the foregoing description it will be understood the present invention provides a new and improved system for supplying conditioning air through a papermaking felt for purging a felt so that the felt arrives at the press nip in a dry condition.
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A felt conditioning system for a papermaking machine in which a stationary air supply plenum chamber is positioned on the back side, i.e., obverse of paper side, of the felt for delivering heated conditioning air to and through the felt to remove water and dirt taken up by the felt from the paper sheet.
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TECHNICAL FIELD
[0001] The present invention relates generally to infant care products, more particularly to a bag for carrying a limited supply of diapers and baby wipes.
BACKGROUND OF THE INVENTION
[0002] When away from home, a parent or other adult may often be accompanied by an infant in diapers. Frequently, the infant's diaper must be changed while away from home, in surroundings that are not equipped with infant care products. For this reason, most adults having care of an infant while away from home carry such infant care products with them in a diaper bag.
[0003] Most diaper bags are designed primarily to store and transport consumable baby care products that are used in caring for the infant while away from home. Many such bags are large enough to also carry a change of clothes, toys, etc. for the infant. Many diaper bags are even large enough to store a rolled-up or folded pad for laying the infant on while changing the infant's diaper. Others open to form a built-in changing pad. These features are attempts to enhance the usefulness of the diaper bag.
[0004] The above-mentioned diaper bags do not, however, solve all problems associated with changing an infant's diaper while away from home. In general, improved forms of diaper bags have become larger and more elaborate over time, designed to contain not only diapers and baby wipes, but many other items such as bottles, formula, a change of clothing and the like. Such diaper bags must be sized accordingly, making them less convenient to carry, especially on a short trip or errand where only one or at most two diaper changes are likely to be needed.
[0005] Many mothers taking a baby on errands leave the diaper bag at home or in the car and stick a diaper and a small pack of baby wipes in their purse. This eliminates the need to take along a diaper bag, but the diaper and wipes can become separated and difficult to find in the purse, which contains many other objects. The present invention addresses this difficulty.
SUMMARY OF THE INVENTION
[0006] The invention provides a bag of limited size configured to hold a package of baby wipes and a small number of diapers with little room left over. As such, the bag of the invention is small enough to fit inside a purse, yet can be easily found and removed when a diaper change is needed. The invention further provides a system for storing baby accessories which comprises such a bag with a package of baby wipes and at least one diaper contained therein with specific dimensions as further discussed in the detailed description which follows, along with a method of using such a system.
[0007] A bag configured for holding a diaper and container of baby wipes according to one aspect of the invention is generally rectangular and includes a front wall, a rear wall, a pair of sides joining the front and rear walls at opposite side edges thereof, a bottom wall and a mouth opposite the bottom wall, which mouth opens onto an internal pocket. The bag when laid flat has a length in the range of 9 to 12 inches, a width in the range of 4 to 8 inches, and can open to provide a mouth and pocket with a cross sectional area in the range of about 5 to 25 in 2 when at object at least 4 inches wide, such as a disposable diaper or container of baby wipes, is placed in the pocket.
[0008] A system for storing baby changing accessories according to another aspect of the invention comprises a generally rectangular bag having a front wall, a rear wall, a pair of sides joining the front and rear walls at opposite side edges thereof, a bottom wall and a mouth opposite the bottom wall, which mouth opens onto an internal pocket. A container of baby wipes is disposed in the pocket and removable from the mouth of the bag. From one to not more than three diapers are stacked on the container of baby wipes in the pocket. The diapers and baby wipes fit closely in the pocket, which may be sized to hold one, two or three diapers plus the container. The diapers plus the flat wipes container fill the pocket in the back with little space left over, but not so tightly that they cannot be easily removed at the time of use.
[0009] A method of using the foregoing baby changing system according to another aspect of the invention includes the initial step of storing at least one diaper and container of baby wipes in the bag, then placing the bag in a larger carrying device (such as a purse) containing other items. At the time of use, the bag is removed from the larger carrying device, and then the wipes and a diaper are removed from the bag. The baby is then changed using the diaper and wipes removed from the bag, and any unused wipes and any diapers can then be placed back in the bag after changing the baby. If the bag has a closure flap thereon for closing the mouth of the bag and a closure device for releaseably securing the flap in a closed position, then the closure flap is opened prior to removing the wipes and diaper from the bag. These and other aspects of the invention are further discussed in the detailed description that follows.
BRIEF DESCRIPTION OF THE DRAWING
[0010] In the accompanying drawing, wherein like numerals represent the same or similar elements throughout:
[0011] FIG. 1 is a front view of a bag according to the invention, with the flap closed;
[0012] FIG. 2 is a front view of the bag of FIG. 1 , with the flap open and the inner pocket contents shown in phantom lines;
[0013] FIG. 3 is a side view of the bag shown in FIG. 1 ;
[0014] FIG. 4 is a top end view of the bag shown in FIG. 1 ; and
[0015] FIG. 5 is a front view of a purse with a bag according to the invention contained therein shown in phantom lines.
DETAILED DESCRIPTION
[0016] Referring to FIG. 1 , a bag 10 according to the invention is preferably made of a soft, flexible durable material such as leather, cloth or fabric. Bag 10 is generally rectangular with a front wall 11 and rear wall 12 sewn together along a pair of side walls 13 and a bottom wall 14 . The top end of bag 10 opens in a mouth 16 than can be closed by a fold over flap 17 which is an extension of rear wall 12 . Flap 17 can be releasably secured to front wall 11 by means of a suitable fastener, such as Velcro, snaps, a button, magnets, and others commonly used in the industry. In the embodiment shown, a pair of hook and loop elements 18 , 19 are sewn to the outside of front wall 11 and the underside of flap 17 , respectively. A product label 21 may be placed below the flap as shown, on the flap on the opposite side from the Velcro closure, or at any other suitably prominent location.
[0017] As shown in FIGS. 2-4 , the walls of bag 10 are configured so that a rectangular container of baby wipes 22 fits closely inside. Side walls 13 and bottom wall 14 provide bag 10 with sufficient depth so that at least one, preferably from one to three, standard size cloth or disposable diapers 23 also fit inside next to the container 22 . However, newborn diapers are smaller than those sold for older babies, such that up to 5 or 6 newborn-size diapers could fit in the bag. This would also be true if only standard size diapers were placed in the bag without a wipes container 22 . Container 22 is most commonly a molded plastic compact or clam shell-style of container containing a small number of moistened baby wipes, but could also be a flexible plastic or foil package of baby wipes.
[0018] The dimensions of bag 10 are essential to its purpose, namely that it be large enough to contain container 22 and diapers 23 and still fit within a larger purse or handbag 30 having its own closure flap 31 and carrying straps 32 ( FIG. 5 ), but not so large that it requires a handle or strap and has to be carried around separately, like a diaper bag. The width of the bag when laid flat (empty of contents) should be at least 4 inches, preferably 4 to 8 inches and most preferably 5 to 7 inches. The length of the bag when laid flat should be at least 9 inches, preferably 9 to 12 inches and most preferably 9 to 10 inches. Side walls 13 in combination with the widthwise dimension of front and rear walls 11 , 12 define the size of an interior pocket 15 and mouth 16 . For this purpose, side walls 13 provide a pocket width of at least 1 inch, generally from 2 to 4 inches, most preferably from 2 to 3 inches.
[0019] The dimensions of mouth 16 will vary due to the flexible nature of the bag walls. In general, if the resulting pocket 15 is provided with greater depth by side walls 13 , then front and rear walls 11 , 12 can be narrower, and the converse is also true. A bag of the invention carrying baby wipes in a container and one diaper could, for example, have pocket dimensions of 2″×5.75″, whereas a bag of the invention configured to carry baby wipes and two diapers could have pocket dimensions of 3″×5″. The hard plastic baby wipes container in this example, typical of those commercially available, is about 4.5″ by 8.5″ by less than 1″ thick (0.25″-0.75″ inch thickness is typical). The side walls or “sides” of the bag could also be just seams, and the pocket depth would then be provided by edge portions of the front and rear walls. Hence the size of the pocket and mouth can be defined by its cross-sectional area when in a position to contain an object such as a baby wipes container at least 4 inches wide therein, and may vary from about 5 to 25 in 2 , preferably from about 10 to 20 in 2 .
[0020] Bag 10 in the illustrated embodiment tapers slightly towards the bottom as shown for decorative purposes and to use less material, recognizing that the width of pocket 15 is best maximized at mouth 16 . The thickness of the fabric or other material used to make bag 10 is not critical to the invention, but should in general be thick enough to be opened and closed many times without failure, but not so thick that is adds unduly to the overall size of the bag. Fabrics ranging from 1/16″ to ⅛″ thick are suitable. Bag 10 can also be made with several different coordinating fabrics, one for the baf body, a different one for the flap and another for the lining. The edge of flap 17 may be provided with a decorative trim or fringe, not shown. Flap 17 preferably extends less than half the length of bag 10 when in its folded-over position as shown in FIG. 1 .
[0021] Although various embodiments of the invention have been illustrated in the accompanying drawings and described in the foregoing detailed description, it will be understood that the invention is not limited to the embodiments disclosed but, as will be appreciated by those skilled in the art, is susceptible to numerous modifications and variations without departing from the spirit and scope of the invention as hereinafter claimed.
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A bag of limited size configured to hold a package of baby wipes and a small number of diapers with little room left over. The bag is small enough to fit inside a purse, yet can be easily found and removed when a diaper change is needed. The invention further provides a diaper changing set which comprises such a bag with a package of baby wipes and at least one diaper.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is the U.S. national stage application of International Application PCT/JP2016/055735, filed Feb. 19, 2016, which international application was published on Sep. 1, 2016, as International Publication WO 2016/136923. The International Application claims priority of Taiwanese Patent Application No. 104105986, filed Feb. 24, 2015. The international application and Taiwanese application are both incorporated herein by reference, in entirety.
TECHNICAL FIELD
[0002] The present invention relates to a hybrid cargo handling method for an oil tanker and a cargo pump mover system used for the method.
[0003] The invention is applicable to oil tankers such as a product oil tanker, an ore/oil carrier, and an oil tanker including a cargo pump in a steam turbine driven cargo pump, a cargo oil tank divided into three or more grades, and a pipe system used in an ordinary merchant ship.
[0004] The invention is contrived to save fuel oil consumption under the existing expensive fuel cost market and to reduce carbon oxides due to air pollution.
BACKGROUND ART
[0005] For a long time, a steam turbine driving method has been used in a mover of a cargo pump, but this method is based on two considered aspects. One aspect is the power demand of the mover and the other aspect is the ease of a rotation control in a full range from 0 to a maximum output and the necessity of an inert gas required by a rule.
[0006] In order to meet these demands, a full set of steam turbines including a cargo pump and an auxiliary boiler system covering a required amount of steam and an inert gas have been used in conventional systems.
[0007] The steam turbine of the mover of the cargo pump consumes a lot of steam. This steam is produced by an auxiliary boiler and the auxiliary boiler is supposed to cover the full demand of the steam turbine.
[0008] During the operation of the auxiliary boiler, the inert gas can be produced using an exhaust gas of this auxiliary boiler. According to a rule for following safety conditions of a cargo pipe for a cargo oil tank during cargo oil handling and other processes of cleaning the cargo oil sorting tank, the inert gas is supplied to a void space of the cargo oil sorting tank.
[0009] The fuel oil is consumed to produce the inert gas itself. If the inert gas is produced by other independent systems, the fuel oil consumption will be reduced due to this produced inert gas.
[0010] Patent Literature 1 discloses an auxiliary boiler system set on a shore to produce steam for a main cargo pump handling system. Also, a scrubber for producing an inert gas to be supplied into an oil tank is provided on a shore.
[0011] The invention disclosed in Patent Literature 1 decreases the weight of the oil tanker by employing a specific approach of removing the auxiliary boiler and the scrubber to save fuel consumed during normal sailing.
CITATION LIST
Patent Literature
[0012] Patent Literature 1: JP 1993-229600 A
SUMMARY OF INVENTION
Technical Problem
[0013] Such an oil tanker having a reduced weight will be limited in terms of properties.
[0014] Thus, the invention provides a method and a system for saving fuel oil consumption and reducing carbon oxides due to air pollution without adopting such an approach.
Solution to Problem
[0015] In order to save fuel and reduce carbon oxides according to the invention, one set of a cargo pump operation system among the cargo pump operation systems for the cargo oil tanks segregating more than three kinds of grade cargo oil, especially the cargo oil tanks segregating three or four kinds of grade cargo oil are changed from the steam turbine drive system into the electric motor drive system. Accordingly, it is possible to provide a highly efficient cargo handling method in consideration of a balance of an inert gas supply amount in the auxiliary boiler.
[0016] The electric motor drive system needs to exhibit the performance even when the system is driven at any rotation speed within a full operation range of the cargo pump in accordance with a cargo oil handling demand.
[0017] For this reason, a rotation control system is used in the electric motor. The rotation control system can be used for any purpose, but in consideration of the motor rotation control and the efficiency of the system, a frequency control using a power thyristor (diode) to a power supply line is the most preferable means for the rotational speed control.
[0018] The invention is applicable to the steam turbine driven cargo pump and includes the electric motor driven cargo pump.
[0019] One set of a steam turbine driven cargo pump is changed as an electric motor cargo pump. The other cargo pumps are driven by the steam turbine.
Advantageous Effects of Invention
[0020] According to the invention, the total thermal efficiency of the main cargo pump handling system is changed drastically. As a result, about 10 to 15% of fuel oil is saved for each cargo handling from the tanker. This means that the discharge amount of carbon oxides to the atmosphere is less than conventional systems while fuel is saved.
[0021] According to the basic knowledge of the mover, the steam turbine drive system has a key weakness compared to others. The steam turbine drive system produces steam by the boiler, the produced steam is used in a steam machine such as one or two stages of steam turbines, and the steam discharged from the steam turbines is condensed with latent heat loss. These cause a large loss in the total system.
[0022] The power source in the invention is two kinds of steam and electric power. This means that the degree of freedom of cargo handling increases. Electric cargo pumps are available if there is a failure in the steam turbine drive system.
[0023] The electric motor driven pump can be easily used from 0 to the full rotation range and can be easily stopped and started only by the control system of the cargo pump. A work on the mover side is not necessary.
[0024] Further, this system has two merits below.
[0025] (1) This system can be changed with almost no additional cost. This is because the electric motor drive system can reduce the auxiliary boiler capacity and reduce one set of a steam turbine. All auxiliary boiler systems including condensers are smaller in size and capacity.
[0026] (2) The system can be changed more easily when the system is equipped with side thrusters in the tankers or the ore carriers. This is because an appropriate system can be constructed when the electric power demand condition is set in consideration of the electric power balance accompanying the steering operation by the side thrusters.
BRIEF DESCRIPTION OF DRAWINGS
[0027] FIG. 1 is a conceptual side view of an application having a combination of cargo pumps driven by a mover of a steam turbine and an electric motor.
[0028] FIG. 2 is a conceptual top view of the application having the combination of cargo pumps driven by the mover of the steam turbine and the electric motor.
[0029] FIG. 3 is a conceptual side view of an application having a combination of cargo pumps driven by a mover of a steam turbine and an electric motor according to another embodiment.
[0030] FIG. 4 is a conceptual top view of the application having the combination of cargo pumps driven by the mover of the steam turbine and the electric motor according to another embodiment.
[0031] FIG. 5 illustrates steps of a method of a system according to an embodiment in an operation start mode.
DESCRIPTION OF EMBODIMENTS
First Embodiment
[0032] An embodiment of the invention is illustrated in the attached drawings.
[0033] FIG. 2 is a conceptual diagram and illustrates an engine room ( 120 ) on a bottom shell ( 15 ) and its peripheral area as a part of an oil tanker. Cargo oil tanks ( 130 , 131 , and 132 ) and a ballast tank ( 133 ) are provided in front of a cargo pump chamber. The rear side of the cargo pump chamber is a stern side of a ship. A residential area and a chimney area are provided above the engine room ( 120 ).
[0034] In the inventive example, one set of a cargo pump ( 7 -A) driven by an electric motor drive system ( 11 ) and two sets of cargo pumps ( 7 -B) and ( 7 -B) driven by a steam turbine ( 10 ) are provided.
[0035] That is, three cargo pumps ( 7 -A), ( 7 -B), and ( 7 -B) are provided for the cargo oil sorting tanks ( 130 , 131 , and 132 ) separately storing three grades of cargo oil.
[0036] The electric motor drive system ( 11 ) includes a power thyristor inverter system ( 12 ) along with a conductance or a reactance and can control a cargo pump rotation in a full range.
[0037] Further, an additional supply system of boiler water such as condensate, supply water, CWC, and FWC is provided in addition to a fuel oil combustion system, a steam drive system, a system of an auxiliary boiler ( 16 ), a condenser, a condensate pump, and a supply water pump.
[0038] As illustrated in FIG. 1 , the mover of the cargo pump is used to drive the cargo pump through an elongated vertical shaft passing through a seal box mounted on a partition wall. The cargo pump is safely held inside the cargo pump chamber ( 121 ) and the mover is assembled inside the engine room ( 120 ).
Second Embodiment
[0039] A detailed embodiment of the invention is illustrated in FIGS. 3 and 4 . FIG. 3 is a schematic conceptual side view of a system ( 100 ). FIG. 4 is a schematic conceptual top view of the system ( 100 ). FIGS. 3 and 4 illustrate elements arranged below an upper deck ( 110 ). Both movers ( 101 and 102 ) of steam turbine are used to drive cargo pumps ( 104 and 105 ) and an electric motor system ( 103 ) is used to drive a cargo pump ( 106 ).
[0040] An oil tanker illustrated in FIGS. 3 and 4 includes an engine room ( 120 ) and a cargo pump chamber ( 121 ). Cargo oil sorting tanks ( 130 , 131 , and 132 ) and a ballast tank ( 133 ) are provided near the cargo pump chamber ( 121 ). The rear side of the engine room ( 120 ) is a stern side of a ship. A residential section ( 122 ) and a chimney section ( 123 ) are provided in the vicinity of the engine room ( 120 ). Reference Numeral ( 110 ) indicates an upper deck.
[0041] In the invention, one set of the electric motor system ( 103 ), the cargo pump ( 106 ) driven by the motor system, two sets of the steam turbine movers ( 101 and 102 ), and the cargo pumps ( 104 and 105 ) driven by the movers are illustrated in the drawings.
[0042] As illustrated in FIG. 3 , the cargo pump mover is used to drive the cargo pumps ( 104 , 105 , and 106 ) through elongated vertical shafts passing through a seal box mounted on a partition wall.
[0043] The cargo oil pump system ( 100 ) which is an embodiment of the invention and is used for the oil tanker or the ore/oil carrier is applied to the oil tanker or the ore/oil carrier separately carrying three or four kinds of grade of cargo oil.
[0044] The oil pump system ( 100 ) of the embodiment can be modified as below. As illustrated in FIGS. 3 and 4 , the system of the cargo pumps ( 104 , 105 , and 106 ) for the cargo oil sorting tanks ( 130 , 131 , and 132 ) storing three or four kinds of grade of cargo oil in the oil tanker or the ore/oil carrier includes one set of the cargo oil pump ( 106 ) which is driven by the electric motor system ( 103 ); the remaining cargo oil pumps ( 104 and 105 ) which is driven by the steam turbine movers ( 101 and 102 ); and one or plural auxiliary boilers ( 160 ) which produce steam for the steam turbine movers ( 101 and 102 ) and an exhaust gas purified into an inert gas ( 163 ) above a scrubber ( 302 ) to be sent to void spaces of the cargo oil sorting tanks ( 130 , 131 , and 132 ) for different oil grades; wherein the electric motor system ( 103 ) includes a frequency conversion control device ( 108 ) and balances a pump capacity with respect to a residual inert gas balance, and wherein a gas from the auxiliary boiler ( 160 ) is sent to the void space of the cargo oil sorting tank through passages ( 147 , 148 , and 150 ) and passages ( 299 , 303 , 311 , 312 , and 313 ).
[0045] As a system using the system ( 100 ) according to another embodiment of the invention, a cargo pump system for the oil tanker or the ore/oil carrier separately storing three or four kinds of grade of cargo oil includes: one or plural auxiliary boilers ( 160 ) which produce steam for steam turbine movers ( 101 and 102 ); a scrubber ( 302 ) which purifies an exhaust gas discharged from the one or plural auxiliary boilers ( 160 ) into an inert gas; an exhaust gas passage ( 161 ) which allows the one or plural auxiliary boilers ( 160 ) to be in gas-communication with a chimney space ( 123 ); gas passages ( 147 and 148 ) which allow the exhaust passage ( 161 ) to be in gas-communication with the scrubber ( 302 ); and gas passages ( 311 , 312 , and 313 ) which allow the scrubber ( 302 ) to be in gas-communication with cargo oil sorting tanks ( 130 , 131 , and 132 ), wherein the one or plural auxiliary boilers ( 160 ) have a capacity smaller than a capacity corresponding to a total pump capacity when all pumps ( 104 , 105 , and 106 ) are driven by the steam turbine movers ( 101 and 102 ).
[0046] In the scrubber ( 302 ), the exhaust gas is purified into an inert gas ( 163 ) in such a manner that sea water (W) supplied from a shower supply ( 306 ) for the sea water is sprayed by a shower nozzle ( 304 ). The produced inert gas ( 163 ) is discharged from the upper portion of the scrubber ( 302 ) and is guided into the upper portions of the oil tanks ( 130 , 131 , and 132 ), and here a drain trapped by the lower portion of the scrubber ( 302 ) is discharged to the outside of the ship.
[0047] In the system using the above-described method, one or plural auxiliary boilers ( 160 ) have a capacity of charging the inert gas into the void space of the cargo oil sorting tank (for example, 130 ) and have a capacity of charging the inert gas into the void space of the cargo oil sorting tank being in gas-communication with the cargo pump ( 106 ) driven by the electric motor system ( 103 ) with the speed control mechanism using the frequency conversion control device in the full performance operation mode while charging the inert gas into the void spaces of the tanks (for example, 130 and 132 ) being in gas-communication with the cargo pumps ( 104 and 105 ) driven by the steam turbine movers ( 101 and 102 ).
[0048] This method is illustrated as a step chart in FIG. 5 .
Third Embodiment
[0049] Another embodiment is a hybrid cargo handling method for oil pump systems ( 104 , 105 , and 106 ) and cargo oil sorting tanks ( 130 , 131 , and 132 ) for three or four kinds of grade in an oil tanker and an ore/oil carrier, wherein one set of the cargo oil pump ( 106 ) is driven by an electric motor system ( 103 ) of which a speed is controlled by a frequency conversion control device ( 108 ) and the remaining cargo oil pumps ( 104 and 105 ) are driven by a steam turbine drive system.
[0050] A method disclosed herein by the invention, that is, the hybrid cargo handling method for the oil pump systems and the cargo oil sorting tanks ( 130 , 131 , and 132 ) for three or four kinds of grade in the oil tanker and the ore/oil carrier is illustrated in FIG. 5 .
[0051] Two steps are as below.
[0052] First, step 1 is a steam turbine mover pump starting step (S 100 ).
[0053] Second, step 2 is an electric motor system pump operating step (S 200 ).
[0054] An aspect of the invention is specifically used in combination with the above-described components and the step (S 1 ) includes the following steps: (i) step (S 100 ) of starting the cargo oil pumps ( 104 and 105 ) driven by the steam turbine movers ( 101 and 102 ) to discharge steam produced from the auxiliary boiler ( 160 ) at a minimum load; and (ii) step (S 200 ) of operating the oil pump ( 106 ) driven by the electric motor system ( 103 ) after an inert gas purified from an exhaust gas and charged into void spaces (for example, 130 and 132 ) of the cargo oil sorting tanks being in gas-communication with the cargo oil pumps ( 104 and 105 ) driven by the steam turbine movers ( 101 and 102 ) exceeds a minimum demand threshold value to control a speed with a frequency conversion control device so that the oil pump ( 106 ) driven by the electric motor system ( 103 ) does not exceed a load equivalent to consuming surplus of residual inert gas balance allocated to the void spaces (for example, 130 and 132 ) of the cargo oil sorting tanks being in gas-communication with the steam turbine movers ( 101 and 102 ).
[0055] The above-described embodiment of the invention illustrates a remarkable energy saving result in total and realizes a drastically improved efficiency of the cargo pump handling system. As a result, 10 to 15% or more of fuel consumption amount can be saved for each cargo handling from the tanker. This means that the discharge amount of carbon oxides to the atmosphere is less than conventional systems while fuel is saved.
[0056] At the same time, even when the inert gas supply for charging the inert gas into the void space of the cargo oil sorting tank meets the demand of the void space by the electric motor driven oil pump ( 106 ) during the oil pump operation, the oil pump ( 106 ) driven by the electric motor system ( 103 ) is controlled by the frequency conversion control device so as not to exceed a load more than the remaining balance allocated to the void spaces of the cargo oil sorting tanks (for example, 130 and 132 ) being in gas-communication with the steam turbine movers ( 101 and 102 ).
[0057] This is because of the following reasons. In the main cargo handling performance, the electric motor does not consume steam and the auxiliary boiler operation itself is not necessary.
[0058] The electric motor just needs the auxiliary boiler in order to charge the inert gas into the void space of the tank. Thus, producing the exhaust gas for the performance of the electric motor is a good point in terms of utilizing the heat of the steam turbine.
[0059] The combination of the electric motor and the steam turbine uses the frequency conversion control device of the motor rotation speed and maximizes the system performance by optimizing the appropriate load balance of the steam turbine mover/electric motor from the viewpoint of the predetermined total pump performance and the production of the inert gas by the auxiliary boiler and is involved with the auxiliary boiler capacity/minimum load threshold value.
[0060] While the invention has been described in detail in terms of the embodiments herein, the applicant does not intend to limit the scope of the appended claims in any way. Additional advantages and modifications will be understood by those skilled in the art. Moreover, the elements described in one embodiment may be employed in other embodiments. Accordingly, the invention in a broad aspect is not limited to the specific details, apparatuses, and embodiments which are disclosed and described herein. Therefore, the invention can be modified from these details without departing from the spirit and the scope of the applicant's general inventive concept.
INDUSTRIAL APPLICABILITY
[0061] The invention is applicable to shipbuilding and marine transportation industries with cargo pumps used as steam turbine driven cargo pumps for three or more grade isolated cargo oil tankers, ore/oil carriers, and product oil tankers.
REFERENCE SIGNS LIST
[0062] 7 -A cargo pump
[0063] 7 -B cargo pump
[0064] 10 steam turbine
[0065] 11 electric motor
[0066] 12 power thyristor inverter system
[0067] 15 bottom shell
[0068] 16 auxiliary boiler
[0069] 99 ore/oil cargo oil sorting tank
[0070] 100 main cargo pump handling system
[0071] 101 mover of steam turbine
[0072] 102 mover of steam turbine
[0073] 103 electric motor system
[0074] 104 cargo pump driven by steam turbine
[0075] 105 cargo pump driven by steam turbine
[0076] 106 cargo pump driven by electric motor
[0077] 108 frequency conversion control device
[0078] 110 upper deck
[0079] 120 engine room
[0080] 121 cargo pump chamber
[0081] 122 residential section
[0082] 123 chimney space
[0083] 130 cargo oil sorting tank
[0084] 131 cargo oil sorting tank
[0085] 132 cargo oil sorting tank
[0086] 133 ballast tank
[0087] 147 gas passage
[0088] 148 gas passage
[0089] 150 gas passage
[0090] 160 auxiliary boiler
[0091] 161 exhaust gas passage
[0092] 162 toward chimney
[0093] 163 inert gas
[0094] 299 gas passage
[0095] 302 scrubber
[0096] 304 shower nozzle
[0097] 306 sea water supply
[0098] 311 gas passage
[0099] 312 gas passage
[0100] 313 gas passage
[0101] S 100 steam turbine mover starting step
[0102] S 200 electric motor system pump operating step
[0103] S steam from boiler
[0104] G inert gas from scrubber
[0105] W sea water
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Oil tanker and or ore/oil carrier can take more good fuel oil consumption through cargo oil handling by usage of electric motor driven system instead of steam turbine driven cargo pump system. Its merit is about 20%.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of and claims priority of co-pending U.S. patent application Ser. No. 15/521,733, filed Oct. 23 2014, the entire contents of which is incorporated herein by reference.
BACKGROUND
[0002] The existing model for online advertising includes stake holders such as advertisers, advertising network/affiliate network, publisher, and users. In the existing model, the advertiser pays advertiser network money e.g.: cost per click (CPC) or cost per mile (CPM). The advertising network goes out to publishers and shares some of the revenue it receives from the advertiser in return for getting traffic from publishers to advertisers. However, this has the drawbacks of the advertisements which are sent to the user having viruses, malware, spyware, corrupt files and other potentially harmful features.
SUMMARY
[0003] With the present invention, there is an ability to become an advertising network using a totally new channel for traffic generation, i.e. user owners. Unlike the prior existing model which utilizes publishers for traffic generation, the present invention uses “user owners” for traffic generation.
[0004] The system of the present invention has numerous advantages. In particular, the present system provides more relevant search results as the entire user behavior can be seen, which is unlike other advertiser networks. When coupled with virus free or trusted ads from a trusted ad server, users are motivated to become a traffic generation advertising network.
[0005] Modifying what end users see, as far as ads/links are concerned, require the user's consent. This could be obtained both at ISP or end user level from the end user because in return, a virus free warranty is provided against infection from ads. This is important as malvertising is a threat.
[0006] The present invention provides a computer implemented system and method for building a profile of a user associated with a particular IP address which includes establishing a proxy server for a plurality of discrete client IP addresses and providing a connection from the discrete client IP addresses to a wide area network through the proxy server. The invention then logs on the proxy server a list of resources provided to each of the discrete client IP addresses and determines a profile of the list of resources provided for each of the discrete client IP addresses based on a predetermined formula. The system of the invention then serves and delivers advertisements (or more generally; “content”) to each of the discrete client IP addresses corresponding to the profile.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The accompanying drawings illustrate various embodiments of the present invention and system and are a part of the specification. The illustrated invention and system and are a part of the specification. The illustrated embodiments are merely examples of the present system and invention and do not limit the scope thereof.
[0008] FIG. 1 a is a schematic of a user accessing a website from a computer or handheld device.
[0009] FIG. 1 b illustrates a system 50 of a computer or device
[0010] FIG. 1 c illustrates a website with an advertisement located within a web browser window and the query status bar.
[0011] FIG. 2 is schematic illustration of a known system for serving content.
[0012] FIG. 3 is a schematic illustration of the system of the present invention.
[0013] FIG. 4 is a flow diagram of the method of the present invention.
[0014] FIG. 5 is another embodiment of the present invention.
[0015] FIG. 6 a and 6 b illustrate another embodiment of the present invention.
DETAILED DESCRIPTION
[0016] As shown generally by FIG. 1 a, there is a user 2 of a computer 4 or handheld device 5 who accesses an Internet website 6 with network connections to a server 7 and database 8 . The user 2 is potentially exposed to many malicious or unsafe advertisements located on the website 6 due to lack of security and validation with the advertising source, even though the website 6 itself may be known as reliable and trusted. Those of skill in the art would recognize that the computer 4 or hand held devices 5 a or 5 b each has a processor and a memory coupled with the processor where the memory is configured to provide the processor with executable instructions. A boot disk 9 is present for initiating an operating system as well for each of the computer 4 or hand held devices 5 . It should also be noted that as used herein, the term handheld device includes phones, smart phones, tablets, personal digital assistants, media and game players and the like. As used throughout, the term “query” or “queries” is used in the broadest manner to include requests, polls, calls, summons, queries, and like terms known to those of skill in the art.
[0017] FIG. 1 b illustrates a system 50 of a computer or device which includes a microprocessor 52 and a memory 54 which are coupled to a processor bus 56 which is coupled to a peripheral bus 60 by circuitry 58 . The bus 60 is communicatively coupled to a disk 62 . It should be understood that any number of additional peripheral devices are communicatively coupled to the peripheral bus 60 in embodiments of the invention. Further, the processor bus 56 , the circuitry 58 and the peripheral bus 60 compose a bus system for computing system 50 in various embodiments of the invention. The microprocessor 52 starts disk access commands to access the disk 62 . Commands are passed through the processor bus 56 via the circuitry 58 to the peripheral bus 60 which initiates the disk access commands to the disk 62 . In various embodiments of the invention, the present system intercepts the disk access commands which are to be passed to the hard disk.
[0018] In further detail, FIG. 1 c illustrates a website 6 with an advertisement 8 to be located at a particular place on the site 6 . There is shown in FIG. 1 c a pending query in the status bar 32 located at the bottom of the web browser with a code to query an ad network. In this manner, advertisement(s) 8 for the website 6 are retrieved from the advertising source. Those of skill in the art would recognize that the computer 4 or hand held device 5 each has a processor and a memory coupled with the processor where the memory is configured to provide the processor with executable instructions. Each of the computers 4 or handheld devices 5 have a discreet IP address associated with the device (and hence, the user 2 ) for online searching and website browsing. It should also be noted that as used herein, the term handheld device includes phones, smart phones, tablets, personal digital assistants, media and game players and the like. As used throughout, the term “query” or “queries” is used in the broadest manner to include requests, polls, calls, summons, queries, and like terms known to those of skill in the art.
[0019] Referring to FIG. 2 , there is shown the present system of online advertising 20 . In this system, the advertiser 22 contacts the ad network 24 which stores the ad 8 . Currently, advertisers 22 pay revenue to the ad networks 24 which then send revenue to publishers 26 . The publisher then sends the ad to the user 28 .
[0020] As shown in FIG. 3 , the stake holders in the system of the present invention 40 include the advertiser 22 , an advertising network or affiliate network 24 , user owners 42 , and publishers 44 . In the present system 40 , advertisers 22 pay revenue to the ad networks 24 who then pay user owners 42 who can act as distribution channels and generate traffic. The user owners 42 with the present invention include various distribution channels as traffic generators. Distribution channels with respect to the present invention include ISPs, businesses or universities, and end user reach (toolbars/AVs etc). The system of the present invention provides the ability to view all user online behavior, and therefore greatly increase optimization of advertising. Further, the advertisers 22 and ad networks 24 may be limited to trusted advertisements and trusted networks which are known to be safe and free of problems such as viruses, malware, spyware, malicious or malformed code. The methods of implementation of the present invention include: 1.) proxy, 2.) client side code, and 3.) DNS.
[0021] In order to make the user owner into a traffic generation entity, certain items of what the user sees as a display on the web page viewed are modified. The items which are replaced/modified or edited include: 1. ads, 2. existing links, 3. links from words (turning words into links)—depending on the previous user behavior, any future pages the user accesses could be filled with newly created links to represent user behavior, and 4 . replace search results from both search engines, such as Google or Bing, or in affiliate sites (adsense like). It is important to maintain the publishers in the
[0022] It is important to maintain the publishers in the present system as the system is replacing ads and other advertising related stuff, and the publishers create the advertising ecosystem. The system of the present invention 40 provides very relevant advertising, and therefore, publishers 44 provide the system 40 more business than the traffic which may possibly be taken away from them because the system 40 brings more relevant advertising which then results in higher return for the publishers 44 .
[0023] FIG. 4 illustrates a flow diagram corresponding to a method 60 of the present system. First the individual or a user hires and contacts an advertiser (Step 62 ). Then the advertiser contacts an ad network or affiliate (Step 64 ) and the sends ads to the user owners (Step 66 ). Next, with the present system the user owners act as distribution and/or traffic generators 68 . The distribution can include entities such as ISP's, businesses, and universities. The publishers 44 are kept in the system and method of the present invention. As the advertisements are significantly targeted, the user owners then contact the advertiser (Step 72 ), and therefore generate increase revenue. The method may be repeated with additional advertising purchases from Step 64 again.
[0024] In an embodiment of the present invention, the system turns words on a web page into links as shown by FIG. 5 . The links which are created by the system of the present invention are user specific, as the newly created links are based on the user's prior searches. The information contained in the prior searches includes the user's IP history, information, and data. The links which are created link to a specific advertiser and may be based on a keyword that the user types into a search engine or social media. This may all be accomplished by use of a predetermined formula or specific algorithm.
[0025] Referring to FIG. 5 , there is shown an illustration of the creating links embodiment of the present invention 80 . When the user 2 of FIG. 1 a accesses a website 6 with their computer 4 or handheld device 5 in this embodiment, the user 2 views their screen 82 various text and content 84 . Based on the prior search history of the user 2 , the words and content 84 on the page of the website 6 are turned into links. For example, in FIG. 5 there is shown text stating: “The bicycle was red. The car had a rack for the bicycle.” 84 . As the user 2 has a recent search history of riding cycling sports and riding bicycles, the word “bicycle” in the web page text 84 creates a link 86 to a cycling website, such as the example indicated as http://www.trek/com. The links 86 which are created from words and content 84 are specific for a particular user 2 based on their particular online search history.
[0026] The analysis parameters of this embodiment of the present invention are what the user sees and what the user types for searches. This provides a profile of what content a particular user (or discrete IP address associated with a user) is interested in when surfing the online marketplace, and creating a discrete online profile/history.
[0027] Further, with this embodiment, the system allows for individual letters in the text of a web page to create a link to a word. For example, the system of the present invention may identify that the user 2 searched recently for “watch.” The present invention is then able to locate the individual letters “w”, “a”, “t”, “c”, and “h”, within the text 84 of a current web page to create a new link by highlighting each letter or connecting the individual letters into a link. For example, in FIG. 5 in the text “The bicycle was red. The car had a rack for the bicycle.” 84 , includes the letters “wa” in the word “was”, the letter “T” in the word “The”, the letter “c” in the word “car”, and the letter “h” in the word “had.” (collectively referenced by 90 ). Together, these individual letters form a new link to a website such as http://www.watchretailer.com 92 which is relevant to the particular word link created by the user's search history associated with a discrete IP address for their device 5 or computer 4 . The particular website link selected with the created word link may be associated with a trusted ad server/network or verified advertisements to assure that the link is free of viruses, malware, and spyware, malformed or corrupt files.
[0028] This embodiment of the present invention can be accomplished with a plug in on the user's browser or at the proxy level. This embodiment is included with the present invention as a particular implementation for FIGS. 3 and 4 .
[0029] IN another embodiment of the present invention, the system replaces the search
[0030] In another embodiment of the present invention, the system replaces the search results provided to a user by a search engine with safe and verified advertisements from a trusted ad server. The system of the present invention may also replace the search results generated by an affiliate site with trusted and verified advertisements from a trusted server. This may be accomplished at the proxy level. This embodiment is illustrated in FIG. 6 a and FIG. 6 b and may be part of the system and method indicated by FIGS. 3 and 4 .
[0031] In FIG. 6 a , and also referring to FIG. 1 a, there is shown a user's computer or handheld device screen 100 which includes a window 110 displaying results 120 from a search engine corresponding with the user's most recent search. (More particularly identified in FIG. 6 a “Search result 1 ” through “Search result n”). Also shown on the computer or device screen 100 is a list of affiliate ads 130 , more particularly identified as “Ad 1 ” through “Ad n”. In accordance with the present invention and as shown in FIG. 6 b , these results 120 and ads 130 are replaced with verified and trusted search results 124 and trusted advertisements 134 .
[0032] The above-described methods according to the present invention can be implemented in hardware, firmware or as software or computer code that can be stored in a recording medium such as a CD ROM, an RAM, a floppy disk, a hard disk, or a magneto-optical disk or computer code downloaded over a network originally stored on a remote recording medium or a non-transitory machine readable medium and to be stored on a local recording medium, so that the methods described herein can be rendered in such software that is stored on the recording medium using a general purpose computer, or a special processor or in programmable or dedicated hardware, such as an ASIC or FPGA. As would be understood in the art, the computer, the processor, microprocessor controller or the programmable hardware include memory components, e.g., RAM, ROM, Flash, etc. that may store or receive software or computer code that when accessed and executed by the computer, processor or hardware implement the processing methods described herein. In addition, it would be recognized that when a general purpose computer accesses code for implementing the processing shown herein, the execution of the code transforms the general purpose computer into a special purpose computer for executing the processing shown herein.
[0033] While the invention has been shown and described with reference to certain exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims and their equivalents. Therefore, the scope of the present invention should not be limited to the above-described embodiments but should be determined by not only the appended claims but also the equivalents thereof.
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There is provided a computer implemented system and method for building a profile of a user associated with a particular IP address. The system and method include establishing a proxy server for a plurality of discrete client IP addresses and providing a connection there from to a wide area network through the proxy server. A list of resources provided to each of the discrete client IP addresses is logged on the proxy server, and a profile is determined for each of the discrete client IP addresses based on a predetermined formula. Advertisements and content are served to each of the discrete client IP addresses corresponding to the user's profile.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of pending U.S. patent application Ser. No. 11/269,044 filed on Nov. 8, 2005, which is a continuation-in-part of pending U.S. patent application Ser. No. 11/122,566 filed May 5, 2005, which claims the benefit of Provisional Patent Application No. 60/581,662 filed on Jun. 21, 2004, and which is also a continuation-in-part of U.S. patent application Ser. No. 11/018,816 filed Dec. 20, 2004, now U.S. Pat. No. 7,270,890, which is a continuation-in-part of U.S. patent application Ser. No. 10/252,236 filed Sep. 23, 2002, now U.S. Pat. No. 6,838,157, all of which are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] This invention relates to electrical sensors for detecting surface reduction wear as it widens and deepens on a surface, particularly wear on curved components such as spring clips in combustion turbine engines.
BACKGROUND OF THE INVENTION
[0003] Components such as spring clips in engines can experience surface wear from contact with other components under operational vibrations and dynamic forces. Sensors have been designed to provide real-time monitoring of component wear during engine operation. Such monitoring improves safety and reduces operating and maintenance costs by indicating a maintenance requirement before it causes damage or unscheduled outages.
[0004] It is known to place multiple sensors at different depths in a coating on a component surface to sense a depth of wear in real time. However, multi-layer sensors require significant extra work and expense to embed because each layer must be laid down separately. Generally, N sensors require about N times more work to install than 1 sensor. Also, placing sensors at multiple depths at a single location is problematic because sensor material is not a good wear material, so these sensors can cause spalling and can reduce the life of the wear material.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] The invention is explained in the following description in view of the drawings that show:
[0006] FIG. 1 is a perspective partial view of a curved component with a 2 D sensor having three nested sub-elements.
[0007] FIG. 2 shows the component of FIG. 1 after wear from an opposed planar contacting surface.
[0008] FIG. 3 shows a 2 D sensor embodiment with a ladder geometry.
[0009] FIG. 4 shows a 2 D sensor embodiment with a film geometry.
[0010] FIG. 5 is a sectional front view of a 2 D sensor with film geometry installed on a coating on a component.
[0011] FIG. 6 shows a view as in FIG. 5 with an opposed planar component causing widening wear on the component and sensor.
[0012] FIG. 7 is a sectional front view of a flat component and sensor being reduced by widening wear from an opposed curved component.
[0013] FIG. 8 is a sectional front view of a sensor installed between electrically insulating layers of a coating on a component.
[0014] FIG. 9 shows a conceptual graph of characteristic measurement data from the sensor geometry of FIG. 1 .
[0015] FIG. 10 shows a conceptual graph of characteristic measurement data from the sensor geometry of FIG. 3 .
[0016] FIG. 11 shows a conceptual graph of characteristic measurement data from the sensor geometry of FIG. 4 , and an acceptable time series envelope.
[0017] FIG. 12 shows a sensor installed on a gas turbine combustor spring clip.
DETAILED DESCRIPTION OF THE INVENTION
[0018] FIG. 1 shows part of a component 20 having a substrate 22 with a surface 24 . The surface 24 has a wear starting position 26 , which is an initial contact area, point, or line of a touching component (not shown). The component 20 and the touching component have different curvatures. This results in a wear pattern that widens 28 predictably as it deepens. For example, the component 20 may be convex as shown, and the opposed component may be planar, or vice versa.
[0019] A 2 D sensor element 30 is installed on an area of the surface 24 . Herein, the term “ 2 D sensor element” means an element that follows a surface geometry at a single level. This definition includes for example a single wire, plural wires, a film, a ladder, and the like, that follows either a planar surface or a curved surface at a single level. The single level may be an outer uncoated surface as shown in FIGS. 1-4 , an outer coated surface as shown in FIGS. 5-7 , o a subsurface level with a further outer coating as shown in FIG. 8 . Examples of curved surfaces include cylindrical and spherical surfaces. In contrast, a “3D sensor element” has features that are distinct at different depths in a surface or coating.
[0020] The 2 D sensor element 30 in this embodiment comprises nested electrical conductor loops in the form of rail pairs 31 A, 31 B, 31 C and respective rungs 32 A, 32 B, 32 C. The 2 D sensor includes a proximal portion 32 A and a distal portion 32 C relative to the wear starting position 26 . Each rung in this embodiment may be independently connected to an electrical measuring circuit 40 that measures an electrical characteristic such as resistance, capacitance or impedance of each loop, and may also energize each loop. This circuit may include an analog to digital signal converter as known in the art. The electrical measuring circuit may be connected 41 to, or be a part of, a monitoring computer 42 , which may include a memory 43 and a clock 44 . In this example each nested loop comprises a zigzag rung between two rails. Zigzag rungs are not essential, but they may increase the sensitivity and/or coverage of each loop compared to alternates such as smoothly curved conductor loops or straight rungs.
[0021] The sensor elements of embodiments herein may be deposited on a substrate or within or on a wear-resistant layer such as a metal, ceramic, or cermet coating on a substrate as variously shown, using a thin film deposition process such as plasma spraying, electron beam physical vapor deposition, chemical vapor deposition, pulsed laser deposition, mini-plasma, cold spray, direct-write, mini high velocity oxy-fuel, or solution plasma spraying, for example. The substrate may be metal or another material such as a ceramic or ceramic matrix composite. An appropriate deposition process may be selected accordingly as known in the art.
[0022] FIG. 2 shows a wear pattern 34 that has been worn to a given depth D by an opposed planar surface. The wear pattern 34 has a predictable growth geometry over time, based on the relative curvatures of the component surface 24 and the opposed surface. The proximal rung 32 A and the middle rung 32 B of the sensor element 30 have been broken in FIG. 2 . The monitoring computer 42 can compute the wear depth D based on the width of the wear pattern 34 relative to its depth when a given rung is broken. Wear can be quantified as a percentage of maximum acceptable wear or in other units, such as age codes or numeric levels progressing from minor wear to maximum wear, as each successive rung 32 A-C is broken.
[0023] FIG. 3 shows a sensor embodiment 50 with a ladder geometry, including two generally parallel rails 51 and multiple rungs 52 A- 52 E connected between the rails. This sensor produces stepwise changes in the characteristic measurement, which is shown as resistance in the embodiment of FIG. 10 . These steps are detectable by the electrical measuring circuit 40 , and allow it to quantify the depth of the wear using only a surface-mounted sensor.
[0024] FIG. 4 shows a sensor embodiment 60 with a film geometry 62 , including a proximal end 62 A and a distal end 62 B relative to the wear starting position 26 . This sensor produces generally gradual changes in the characteristic measurement, as shown in FIG. 11 . The electrical measuring circuit 40 quantifies the wear based on these changes.
[0025] FIG. 5 shows a sectional front view of a component with a sensor element 62 installed on a coating 70 on the substrate 22 . The coating 70 may be a wear coating, an electrical insulation coating, or a thermal insulation coating over an optional bond coat 72 on the substrate 22 as known in the art.
[0026] FIG. 6 shows a view as in FIG. 5 with an opposed planar surface 74 causing wear on the coating and sensor. The film 62 has been reduced by this wear, resulting in a changed electrical characteristic of a circuit that includes sensor element 62 .
[0027] FIG. 7 shows a sectional front view of a flat component 21 with a sensor element 62 being reduced by wear from an opposed curved surface 75 .
[0028] FIG. 8 shows a sectional front view of a sensor element 62 installed between electrically insulating layers 76 , 77 within a coating 70 on a component.
[0029] The sensor embodiments herein may be formed as follows:
[0030] 1. If the substrate has a high dielectric constant, as with an insulating ceramic like A 1 2 O 3 , the sensor element may be deposited directly on the substrate. Otherwise, deposit an electrically insulating layer 76 on the substrate surface 24 using a material such as an oxide ceramic with high dielectric/insulating properties like Al 2 O 3 , Yttria Stabilized Zirconia, and MgAl 2 O 4 .
[0031] 2. Deposit the sensor layer 62 using an electrically conducting material with oxidation resistance at the operational temperature. For example Ni—Cr is suitable for operation at about 500° F. (260° C.), which works for a gas turbine combustor spring clip operating in this range. An exemplary sensor thickness is in the range of about 5-25 microns, with 5 microns being one embodiment.
[0032] 3. If an electrically conductive wear coating is to be applied over the sensor, then first deposit an electrically insulating layer 77 over the sensor using an insulating material such as described in step 1. Such insulating layer 77 may be applied over the sensor without a further wear coating.
[0033] 4. Optionally deposit a wear coating 70 , such as an alloy of Cr 2 C 3 —NiCr or WC—Co, or commercial products known as Stellite 6B or T800. An exemplary thickness of the wear coating is in the range of about 0.4-0.5 mm.
[0034] Optionally, a trench or depression may be cut into the substrate for a sensor element, then the trench bottom surface may be coated with electrical insulation, then the sensor element may be deposited on the electrical insulation, then the sensor element may be coated with electrical insulation, then the trench may be filled with a wear resistant material or with the substrate material to achieve a smooth contact surface.
[0035] FIG. 9 shows a conceptual graph of characteristic measurement data from the sensor 30 of FIG. 1 . As each rung 32 A, 32 B, 32 C is successively broken by wear, a respective resistance measurement 32 AO, 32 BO, 32 CO between respective rail pairs 31 A, 31 B, 31 C jumps from low to high resistance.
[0036] FIG. 10 shows a conceptual graph of characteristic measurement data from the sensor 50 of FIG. 3 . As each rung 52 A- 52 E is successively broken by wear, a respective step 52 AO- 52 EO occurs in the resistance measurement of the sensor.
[0037] FIG. 11 shows a conceptual graph of characteristic measurement data from the sensor 60 of FIG. 4 . Also illustrated is an acceptable wear envelope 84 for the measurement data curve 80 . When a maximum wear limit 84 is reached, maintenance is required. The monitoring computer 40 may predict when this limit will be reached based on the slope of the measured data curve, and can thus provide a maintenance alert with a predetermined lead time.
[0038] FIG. 12 illustrates a sensor herein applied to a gas turbine combustor spring clip 90 having a base 91 , a spring plate 92 with a curved wear starting position 26 , an electrical insulation layer 94 , a sensor element 62 , and a sensor lead 63 .
[0039] The monitoring computer 42 may store a time series of actual measured data 80 from each sensor, starting from an installation or replacement time of the sensor. Engineering data may be stored in the computer to provide an acceptable time series envelope 82 for the measured data. If a sensor does not measure an expected amount of wear after a given time interval, this may indicate a failed sensor, a bad connection, a loose component, or a manufacturing inconsistency. The clock may be configured to count operating time, real time, on-off cycles, and/or thermal cycles.
[0040] Each sensor 30 , 50 , 60 may have a proximal portion 32 A, 52 A, 62 A that touches or crosses the wear starting position 26 as variously shown. Such a sensor will indicate even a slight amount of wear of the surface, which can provide early validation of the sensor and component. The computer may issue an alert if an actual measurement of the electrical characteristic over time is not within the acceptable time series envelope, indicating that the sensor is changing substantially faster or slower than expected.
[0041] While various embodiments of the present invention have been shown and described herein, it will be obvious that such embodiments are provided by way of example only. Numerous variations, changes and substitutions may be made without departing from the invention herein. Accordingly, it is intended that the invention be limited only by the spirit and scope of the appended claims.
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A wear sensor ( 30, 50, 60 ) installed on a surface area ( 24 ) of a component ( 20, 21 ) subject to wear from an opposing surface ( 74, 75 ). The sensor has a proximal portion ( 32 A, 52 A, 62 A) and a distal portion ( 32 C, 52 C, 62 C) relative to a wear starting position ( 26 ). An electrical circuit ( 40 ) measures an electrical characteristic such as resistance of the sensor, which changes with progressive reduction of the sensor from the proximal portion to the distal portion during a widening reduction wear of the surface from the starting position. The measuring circuit quantifies the electrical changes to derive a wear depth based on a known geometry of the wear depth per wear width. In this manner, wear depth may be measured with a surface mounted sensor.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of application Ser. No. 09/741,559, filed Dec. 20, 2000, now allowed, U.S. Pat. No. 6,421,148 B2 and also incorporates herein Provisional Application No. 60/175,001, filed Jan. 7, 2000.
FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
BACKGROUND OF THE INVENTION
1. Technical Field
This invention relates generally to holographic diffusers and more specifically to surface holographic diffusers.
2. Background Art
Holographic diffusers of the reflective or transmissive type are well known in the art. Additionally, LCD displays, projection displays, illumination systems, irradiation systems that operate outside of the visible region, beam scanning systems, and other light distribution devices, which can make use of holographic diffusers, and which can be designed to operate for narrow or wide wavelength band monochrome or for color applications, are also well known in the art. For example, an LCD display typically uses a holographic diffuser either to augment the back lighting of the LCD display or to direct the transmitted display light to an observer located within a particular range of viewing angles. To accomplish this the holographic diffuser directs the diffused light in particular paths of propagation designed to fill a specific range of viewing angles.
For example, if an aircraft cockpit display has a holographic diffuser, the head box of the pilot will be the volume that could be occupied by the pilot's eyes from which the pilot can be expected to view the output of the display. Therefore it is advantageous to design the holographic diffuser to direct the light transmitted by the LCD display to the head box of the pilot. Thus, it is known to redirect light using holographic diffusers.
However, it is difficult to maintain uniform luminance over the range of viewing angles that fill the entire volume of the pilot's head box and to produce a sharp luminance fall-off at the edges of the viewing angle range. This difficulty exists because each holographic diffuser design causes display luminance to be a variable function of viewing angle. As a result, display luminance can vary detrimentally when viewed from within the pilot's head box and the luminance cut-off at the fringes of view lacks sharpness. This is generally attributable to two undesirable properties known holographic diffusers. Firstly, as the light's angle of incidence on a holographic diffuser approaches the limits of acceptable angles of incidence consistent with its design, the hologram's diffusion properties begin to break down and the incident light begins to transmit through the hologram without becoming diffused or deviated in propagation angle. Secondly, the corresponding plot of display luminance as a function of viewing angle resembles a bell-shaped curve. This causes the viewed display images to become dim as viewing angles approach the edges of the viewing angle range. Further, considerable wasted light falls outside the useful range of viewing angles owing to lack of sharpness in luminance fall-off at the fringes of the viewing angle range of interest.
FIG. 1 is a side view of a conventional diffusion screen arrangement in the art. With reference to FIG. 1, a collimated, or partially collimated, white light input beam 10 illuminates a refractive medium substrate 12 and a holographic film diffuser 13 at normal incidence. The holographic film 13 diffuses the projected output beam 14 over angular range λ. The angle λ shown in FIG. 2 is the halfpeak full width angle of the luminance angular distribution profile between halfpeaks 20 . Little, or no, color dispersion is noticeable.
Referring to FIG. 1A, it is noteworthy that when a collimated, or partially collimated, white light input beam 10 is incident on refractive medium substrate 12 at an angle (p greater or less than 90°, the beam exiting the hologram can be designed to maintain the same (or nearly the same) diffusion angle, λ, as that for normal incidence. Alternatively, referring to FIG. 1B, with normal incidence of collimated, or partially collimated, white light input, an output beam with a diffusion angle, λ, can be projected in a direction that is not normal to the substrate. This can improve the luminance of an aircraft cockpit instrument display located below the pilot eye level, and with the instrument display face normal at a considerable (20° to 30° or more) angle to the pilot's direct view line. This can be accomplished by projecting the diffused output beam away from the instrument face normal and toward the center of the pilot's head box.
Also, designs of holographic diffusers are possible in which the input white light collimated, or partially collimated, beam and the propagation direction of the diffused output beam both deviate from the substrate (or instrument display face) normal.
In these prior art diffuser designs, the gradual luminance fall-off at the fringes of the viewing angle range (and at angles beyond those fringes) causes a waste of light resulting in reduced display luminance. Therefore, to minimize wasted light and maximize the light flux captured within the viewing angle range of interest, it is advantageous to maximize the slope at the halfpeak points of the luminance angular distribution curve.
In addition, for vehicle illumination applications, light beyond the pilot's headbox contributes to undesired reflections off of the windows, commonly referred to as canopy reflections, degrading night visibility. Therefore, a sharp cutoff in luminance outside the headbox minimizes the potential for this to occur.
SUMMARY OF THE INVENTION
This invention is particularly useful as a beam deflecting diffusion screen for displays, such as LCD instrument panel modules in aircraft cockpits and heads-up displays although its application is not limited to displays. A set of narrow superimposed deflected diffused beam profiles with sharp luminance cut-offs at their halfpeak full width points forms a composite angular luminance distribution. By concentrating these superimposed light beams that project from a display panel and by capturing them within the pilot's head box, efficiency is improved by minimizing the light wasted by projection outside the pilot's head box. Although an individual projected narrow beam angular profile does not, by itself, render the display luminance uniform as a function of viewing angle, the superposition of a plurality of individual narrow beams can be designed to generate uniform luminance over a wide viewing angle range of interest.
The invention is accomplished with the structure and method of the present invention by sending collimated, or partially collimated, light through a substrate with a film matrix comprising a nested plurality of individual joined geometrically shaped holographic cells. The cells comprising the matrix are subdivided into groups. Each cell within a group contains a uniquely patterned holographic diffuser which may advantageously be a surface holographic diffuser. This generates a diffused narrow light beam projected in a direction diverse from that projected by every other cell in the group. The superposition of the variously directed diffused narrow light beams projected from each cell group produces a combined resultant diffused wide light beam. The resultant light beam has a luminance angular distribution profile with sharply vertical slopes at its halfpeak points and a substantially flat and wide peak over a wide viewing angle range of interest.
The display luminance thus produced is uniform over a wide range of viewing angles that span the dimensions of pilot's head box. This range of angles is centered on a specific beam deflection angle that passes through, or in close proximity to, the midpoint of the pilot's head box. Thus the matrix of cells on the display produces a uniform luminance over the entire surface of that display and when viewed from any point within the pilot's head box. The resulting display luminance is substantially uniform over a wider range of viewing angles than is known in the art and the sharpness of the luminance fall-off at the angular distribution profile halfpeak points is greater than is known in the art.
In the preferred embodiment, a non-alternating, single image is also provided for both eyes rather than alternating a separate right eye image with a separate left eye image. However, by means of controllable switchable holograms, it is also possible to project time-sequential alternating different left and right eye images to generate a stereo effect. This embodiment is enabled by the sharp luminance fall-off at the edges of a beam projected at an observer thereby making it possible to place the edge of a projected beam between the right and left eyes. Accordingly the projected image is seen by only one eye without a significant illuminated area projection into the other eye. By dynamically scanning the projected beam back and forth to position the illuminated region of the projected beam first only on one eye and then on only the other eye, it is possible to display a dynamically varying stereo image. The stereo effect is generated by creating the appropriate different perspective view of a three dimensional scene for each eye.
It is necessary for the observer's head position to be accurately positioned to enable the beam edges to fall between the observer's eyes. Alternatively, a head position sensing device can feed the observer's eye positions back to the switchable hologram's scan control system so that the scan can be dynamically corrected to place the beam edges between the observer's eyes.
This invention is most useful for applications where collimated, or partially collimated, light is incident on a display and a need exists to project the light transmitted by the display into a wider and more diffuse beam. A further enhancement of its usefulness occurs when the projected diffuse beam is uniformly distributed over a desired wide range of viewing angles and with sharp luminance cut-offs at the edges of that range. The projected diffuse beam can also have an asymmetric output beam envelope (that is, one having different angular widths in various profile planes rotated at different angles about the output beam's propagation direction), and which has a high efficiency with little or no color dispersion. It may also be desired to have the option of deflecting the axis of this output beam envelope at a different angle from the input beam direction. An asymmetric output beam envelope and/or one having an axis different from that of the input beam is useful for minimizing light flux that fails to fall within a pilot head box having asymmetric dimensions and/or one that is positioned away from the display normal.
By creating a matrix of holographic cells arranged in a regular pattern on or within the surface of the diffusion screen, the adjacent cells of a subgroup of the matrix have different holographic designs each of which deflects the diffused beam projected therefrom in a different direction. The beam spread and deflection direction of each projected output beam can be controlled by means of each different subgroup cell holographic design. The superposition of diffused projected output beams thus produced generates a composite angular luminance distribution with sharp profile slopes at its halfpeak points and a substantially flat wide peak. The composite projected beam has the desired diffusion spread and propagation direction.
Thus, the present invention uses a method and apparatus for sending light beams from a display through a substrate matrix of nested individually joined geometrically shaped cells. The cells are divided into subgroups wherein each cell of a subgroup contains a patterned holographic diffuser with a different design or projection angle for optimal diffusion to occur. Each cell of a subgroup projects a diffused light beam with a different angle of propagation from that of the other cells of the subgroup.
Owing to the holographic diffuser's repetitive pattern of cell subgroups, there are many more cells than beam projection directions. Therefore each cell has a beam projection direction shared with many other cells in the matrix. The angular distribution of light incident on a holographic diffuser cell can be widened by the cell's diffusion properties. Thus the angular distribution of the beam projected from that cell can be wider than that of the incident light beam. Further, the beam projected from that cell can propagate in directions diverse from that of other cells of its cell subgroup.
Therefore the angular distribution of the composite beam projected from a subgroup of cells can be wider and, possibly more angularly asymmetric, than any of the individual component beams comprising the composite beam. Further, because the composite beam can be comprised of a plurality of individual beams having narrow angular distributions (compared with the composite beam's distribution), the angular distribution profile slope at the composite beam's halfpeak points can be sharp and nearly vertical, similar to that of the narrow beams. When the display is viewed from points within the pilot's head box, display luminance can be a uniform function of viewing angle because the peak composite projected beam's angular distribution is substantially flat over a wide range of viewing angles. Thus a predetermined beam spread and deflection angle is created in relation to the viewer. Photometric efficiency is maximized by virtue of high, nearly vertical, slope angles produced at the fringes of the luminance angular distribution profiles projected from cell subgroups across the display surface.
BRIEF DESCRIPTION OF DRAWINGS
Brief Description of the Several Views of the Drawing
FIG. 1 is a side view of a prior art diffusion screen arrangement.
FIG. 1A is a side view of a prior art holographic diffuser wherein the incoming angle incidence of input light is not normal to the face of the holographic diffuser.
FIG. 1B is a side view of a prior art holographic diffuser wherein the outputted light is not normal to the surface of the holographic diffuser.
FIG. 2 is a profile plot in Cartesian coordinates showing the prior art bell curve function of luminance verses viewing angle for a specific projection angle.
FIG. 3 is a perspective view of the input side of the holographic diffuser of the present invention.
FIG. 4 is a perspective view of the output side of the holographic diffuser of the present invention.
FIG. 5 is a perspective view of the holographic diffuser of the present invention wherein 18 sided cell subgroup shapes are used.
FIG. 5A depicts the nested holographic cells of a cell subgroup of FIG. 5 .
FIG. 6 is perspective view of the holographic diffuser of the present invention wherein rectangular holographic cell subgroup shapes are used.
FIG. 6A depicts the nested holographic cells of a cell subgroup of FIG. 6 .
FIG. 7 is perspective view of the holographic diffuser of the present invention wherein triangular holographic cell subgroup shapes are used.
FIG. 7A depicts the nested holographic cells of a cell subgroup of FIG. 7 .
FIG. 8 is a graph in Cartesian coordinates of resultant luminance versus projection angle for three superimposed diffusion profiles of the present invention when partially collimated light is input to a holographic diffuser.
FIG. 9 is a graph in Cartesian coordinates of resultant luminance versus projection angle for two superimposed diffusion profiles of the present invention when partially collimated is input to a holographic diffuser.
FIG. 10 is a graph in Cartesian coordinates of resultant luminance versus projection angle for two superimposed diffusion profiles of the present invention when collimated light is input to a holographic diffuser.
FIG. 11 is a side view of the first element of the second embodiment of the present invention.
FIG. 12 is a side view of the complete second embodiment with both elements in place.
DETAILED DESCRIPTION OF THE INVENTION
Mode(s) for Carrying Out the Invention
FIGS. 3 and 4 show a holographic diffuser 30 in accordance with present invention. Referring to FIG. 3, the holographic diffuser 30 is made up of nested individual joined geometrically shaped cells that form a matrix of cells disposed across holographic diffuser 30 . These cells are clustered in a contiguous arrangement of nested cell subgroups 301 that together form the patterned holographic diffuser 30 . Each individual joined geometrically shaped cell of cell subgroup 301 comprises an individual patterned holographic diffuser element. Each holographic diffuser element of a cell subgroup diffuses the input light and projects the diffused beam in a direction unique from that projected by the other diffuser elements of its cell subgroup. A display 1 , which may be typically a backlit LCD display is shown in FIG. 3 . Incident light 2 comprised of light rays 5 having various directions of propagation from the display 1 are incident upon holographic diffuser 30 .
It is noted that the distance between display 1 and holographic diffuser 30 is not drawn to scale, and in practice the closer the display is to the diffuser, the easier it is to produce a clear image without resolution loss. Therefore, it is preferred that holographic diffuser 30 be laminated or attached to display 1 . If the holographic diffuser is a surface type, then the laminated surface should not be the hologram surface. Instead, the hologram surface should face the display with a minimal air gap in order to minimize resolution degradation.
In order to prevent resolution loss by the holographic view screen 30 , the size of the subgroup 301 of holographic cells must be smaller than a display pixel. As a rule of thumb, a subgroup dimension should not exceed half the corresponding pixel dimension. Thus ,the area of the subgroup should not exceed one fourth (¼) the area of a display pixel.
Further, those skilled in the art will realize that edge effects at the boundary between adjacent holographic cells may prevent the desirable abrupt “step function” change of holographic properties in the transition region between cells. Therefore, a loss of holographic performance occurs in the boundary area between two cells. This loss is more pronounced for smaller holographic cells owing to the greater percentage of the cell area occupied by the transition region between smaller cells. Accordingly, the area of the holographic cells comprising a subgroup 301 should be made no smaller than required to prevent resolution loss.
In FIG. 3, partially collimated light 2 incident on holographic diffuser 30 passes through its multiple cell structure. Each individual nested holographic element of this structure diffuses the light it intercepts and projects it toward some portion of the pilot's head box. Each cell comprising a cell subgroup 301 projects its diffuse beam in a direction diverse from the other cells of that subgroup. The superposition of all these diversely projected beams form a composite beam that can be viewed from all points within the pilot's head box. The luminance versus viewing angle plot of FIG. 8 is an example of the luminance of a subgroup of cells as a function of viewing angle for observation points within the pilot's head box. Note that FIG. 8 is a profile plot taken through a three-dimensional plot representing two orthogonal angular dimensions (representing directions of light flux propagation passing through the area of the pilot's head box) and the luminance dimension.
Accordingly, there could be a three-by-three array of diffused beams projected at different projection design angles from a subgroup of nine holographic cells. The plot of FIG. 8 could be a profile slice taken through three of the nine projected beams. The three dashed line plots 80 of FIG. 8 represent luminance angular profiles of individual projected beams, each centered on its unique projection design angle. The solid line 83 represents the composite sum of the individual projected beam luminance angular distributions 80 .
Note that each beam plot crosses the adjacent beam plot at the common half peak point of both beams. This condition, necessary to produce a uniform luminance function of viewing angle, is implemented by selecting the angular separation of projection design angles of the individual beams to be equal to the angular separation of their half peak points.
The profile plot of a three-by-three arrangement of diffused beams illustrated by FIG. 8 is one of many possible arrangements. FIG. 9 is an example of a profile plot through the center of a pair of projected beams that could be in a one-by-two, a two-by-two, a three-by-two, or any N-by-two arrangement of beams projected from a holographic diffuser's cell subgroup 301 . Of course, there are also many other possible arrangements, such as three-by-four, three-by-five, four-by-four, or in general, N-by-M, where the N and M variables could be any integer value within reason.
A portion of the diffused beams 305 meet at a location 100 (shown in FIG. 4 as the eye location of the viewer) which is within a designated spatial region such as a pilot's head box. These portions of diffused beams are individual viewing angles from the eye location 100 to each of a plurality of cell subgroups 301 on the holographic diffuser 30 . At location 100 , the diffused beam portions projected along viewing angles 305 are superimposed.
The superimposed beam portions are shown graphically as an output angular distribution profile curve in FIG. 8 by curves 80 that, added together, form the desired curve 83 . By virtue of the uniform luminance over the wide range of viewing angles in FIG. 8, the display luminance for viewing angles 305 , which are within that uniform luminance angular range, is also uniform. Accordingly, the luminance of the display is optimized at viewing location 100 . Additionally, the wasted light outside the viewing angle region of interest of a traditional holographic diffuser is overcome by curve 83 , which has a nearly vertical slope at halfpeak points 82 .
This improvement is illustrated by comparing FIG. 8 with FIG. 2 . In the present invention, it is readily seen from FIG. 8 that the luminance in the vicinity of the halfpeak points increases or decreases in a very sharp fashion. This is in contrast to the prior art FIG. 2 wherein the luminance is more of a bell curve shaped function having a relatively small angular region of uniform luminance and a more gradual variation of luminance in the angular vicinity of the halfpeak points. The resulting wasted light flux is undesirable in a display because it reduces the angular viewing range of adequate luminance. This phenomenon is generally referred to in the art as “the low slope problem at the halfpeak point”.
Referring again to FIGS. 3 and 4, the adjacent nested holographic cell subgroups 301 can be implemented in an endless variety of nested geometric shapes. Three examples of these are illustrated in FIGS. 5, 6 , and 7 . FIG. 5 illustrates a holographic diffuser 50 comprised of a nested matrix of 18 -sided polygonal cell subgroups 501 . FIG. 6 illustrates a holographic diffuser 60 comprising a nested matrix of rectangular cell subgroups 601 . FIG. 7 illustrates a holographic diffuser 70 comprising a nested matrix of triangular cell subgroups 701 .
Each of these subgroup shapes is filled with a nested matrix of holographic cells. Examples of these are illustrated in FIGS. 5A, 6 A, and 7 A. FIG. 5A shows how seven nested hexagonal holographic cells 502 can fill cell subgroup 501 . FIG. 6A shows how nine nested rectangular holographic cells 602 can fill rectangular cell subgroup 601 . FIG. 7A shows how sixteen nested triangular holographic cells 702 can fill triangular cell subgroup 701 .
Each different geometric shape has as its own holographic light distribution properties which contribute to the goal of widening the resultant diffused beam in an angularly uniform luminance distribution and with minimum waste outside the angular region of interest to enable the invention.
Nesting of the cell subgroups and of the cells comprising them is advantageous because gaps between subgroups, or between the cells that comprise them, would create void areas having no holographic diffusion properties. Light leakage through said void areas would cause either light losses or unwanted non-uniform display luminance owing to nonuniform diffusion properties.
The holographic properties of cell subgroups and the cells that comprise them differ. The holographic properties of each cell subgroup are identical to those of every other cell subgroup of the holographic diffuser. This ensures identical diffusion characteristics for the composite beam projected from each cell subgroup. The holographic properties of the holographic cells comprising each cell subgroup differ from each other. This is necessary for increasing the prior art diffusion angle 14 defined in FIGS. 1, 1 A, and 1 B. In addition, as previously described, this is necessary for obtaining luminance uniformity over the design range of viewing angles.
FIG. 10 is an example of the combined luminance angular profile obtained when collimated light is input for a hologram diffusion screen designed for partially collimated light, such as that for which the luminance angular profile is illustrated in FIG. 9 . The distribution cells in FIG. 9 have design angles differing by an amount that causes the two luminance angular profiles cross at a common luminance half peak point. This ensures that the luminance angular distribution profile for the combination, or superposition, of the two luminance distribution profiles projected from the two cells is nearly uniform between the two holographic cell design angles.
However, when the two cells are illuminated by more collimated light than that for which their design angles were configured, the resulting distribution profiles 150 illustrated in FIG. 10 will be narrower than those of FIG. 9 . Accordingly, the individual luminance profiles 150 of FIG. 10 fail to cross at a common half peak point thereby generating a combined luminance profile with a deep luminance valley between the two luminance profiles 150 . The resulting luminance angular non-uniformity in FIG. 10 can be remedied by redesigning the holographic diffuser to have a sufficiently small angular separation between the projection design angles of the two cells to make its two individual luminance profiles cross at a common half peak point. In this way it is possible also to decrease wasted light and to maintain luminance uniformity for collimated, or nearly collimated light input. This will produce uniform display luminance over a larger angular viewing range in comparison to the prior art which fails to use a multiplicity of individually joined geometrically shaped cell subgroups 301 or a superposition of the diffused outputs beams of such cell subgroups.
Specifically, again referring to FIGS. 3 and 4, and as noted above, the present invention creates a holographic diffuser 30 that has a pattern of holographic cell subgroups 301 distributed over the face of the diffuser and/or within the substrate. If the nested adjacent cells within each cell subgroup 301 have different holographic diffuser designs, then a collimated or partially collimated white (or monochrome) light beam input can generate a superposition of two or more diffuser output beam angular distributions (see FIG. 8 and FIG. 9 ). This is accomplished by generating output diffusion beams in at least two different directions.
The present invention is therefore able to function with both collimated and partially collimated light because each cell produces a superimposed resultant image at viewing location 100 resultant from a sum of diffused beams at projected at different angles. This results in the composite output distribution 83 of FIG. 8 from its components of narrow output distributions 80 . This also makes it possible to redirect diffused light beams to fill a viewing angle range of interest when the incident light 5 is normal to the diffuser 30 as shown in FIG. 1B or when it is not normal to the diffuser 30 as shown in FIG. 1 A.
It is known in the art that backlighting an LCD display with collimated or partially collimated light considerably improves the contrast of said display. However, the greater the backlight collimation, the more difficult it becomes for current art diffusion screens to illuminate a wide range of viewing angles uniformly and efficiently (without significant wasted light flux). This invention utilizes collimated, or partially collimated, backlighting to enable the simultaneous improvement of display contrast, uniformity, and efficiency over that provided by current art view screens for a wide range of viewing angles.
Thus overall, the invention improves angular uniformity, which is the luminance uniformity of any cell subgroup in the matrix as a function of viewing angle.
A second embodiment of the present invention uses two or more holographic diffusers to diffuse passed light that was not diffused in a first pass through a first holographic diffuser as discussed in detail below.
Another property of holographic diffusers is the tendency to become transparent, i.e., to become non-diffusing transmitters, when the incident beam direction differs sufficiently from its design projection angle. This property is illustrated by FIG. 11 . In particular, referring to FIG. 11, incident beam 5 is diffused by the diffuser 30 to create diffused beam 7 . Beam 5 a is incident at an angle relative to the projection angle, and as discussed above, beam 5 a is transmitted without being diffused by the diffuser. It is also noted that input beams 5 and 5 a are spatially separated for illustration purposes. The beams should, in practice be superimposed on the same area or across the entire substrate 30 .
However, as shown in FIG. 12, in order to eliminate the non-diffuse transmitting property of beam 5 a incident at an angle relative to the projection angle, a second holographic diffuser 30 can be added to the first. The second added holographic diffuser 30 a can be air-spaced from the first holographic diffuser 30 . Preferably, it would be laminated to the first holographic diffuser 30 , for example, should volume holograms be employed. This would inhibit Fresnel reflection losses. In addition, any multilayer diffuser approach must be mindful of the resolution losses that would result from an increasing gap between the display and the diffusion screen.
Referring back to FIG. 12, the second holographic diffuser 30 a would also transmit most parts of the diffusion profiles due to the first beam 5 . The parts of the first beam's diffusion profile, which are closely aligned with the second beam's angle of incidence, would undergo a second stage of diffusion. Also, the designs of both holograms would depend on whether or not the interfaces between them are laminated or air-spaced.
Further, more than two holographic diffuser layers, may be used to accommodate an even larger range of input beams angles to be diffused. Also, the axes of symmetry of the diffusion profiles need not be designed to be parallel to the corresponding input beams.
Note that, unlike holograms of the volume type, surface holograms require a refractive index difference for the two media adjacent to the holographic surface. The surface hologram design must be tuned to that index difference. The magnitude of the scatter from a given surface hologram feature increases with larger index transitions across the surface. Accordingly, the scatter magnitude is greater when the hologram surface is bounded by air or vacuum than when it is bounded by a laminate. If the laminate index equals that of the surface hologram medium, then the scatter properties of the surface hologram are nullified.
It is also possible to generate different surface hologram patterns on each face of a sheet of surface hologram medium thereby making it possible to eliminate half of the above mentioned holographic diffusion layers. Again, it is advantageous to have a small airspace between layers and between the display surface and the adjacent surface hologram to maximize the scatter magnitude of the hologram.
Surface holograms can be recorded by any of the various means known in the art. For high volume production applications, it is most economical to emboss the holographic patterns from a master. It is known in the art to computer-generate holographic recordings of both the volume and surface type.
Other embodiments of this invention implement controllable switchable holograms as described in U.S. Pat. No. 6,115,152 issued on Sep. 5, 2000 and in U.S. Pat. No. 6,317,228 issued on Nov. 13, 2001, both by inventors Popovich, et al. These patents are hereby incorporated by reference in their entirety to the extent that no conflicts exist. A controllable switchable hologram, described as an “electrically switchable holographic optical element (ESHOE)” in U.S. Pat. No. 6,317,228, can be fabricated in reflective or transmissive form. One or more specially designed ESHOEs can:
project images that change, move, vary in size, and/or vary in color;
project spots that dynamically move, vary in size, and/or vary in color;
combine light from multiple different collimation sources into a single projected beam by using multiple ESHOEs;
homogenize a beam that can dynamically vary in divergence, propagation direction, and/or color; and
vary the intensity of (or dim) the propagated light in each of the above applications or as a stand alone attenuator element.
Implementation of light diffusion techniques defined herein, in combination with ESHOEs, can make illumination or irradiation objects generated by the latter have spatially more uniform and with more sharply defined illumination or irradiation edge boundaries thereby increasing the efficiency and the uniformity of light distribution within these objects. Use of ESHOEs in combination with the herein defined diffusion techniques adds the possibility of dynamically changing holograms that can generate dynamic variations in color, size (or scale), divergence, and/or propagation direction (or angular movement). The latter finds application in scanning systems and for generating movement and a dynamically varying illumination of an object or multiple objects in a display.
A diffuser in accordance with this invention can be implemented by a surface hologram, a volume hologram, or a controllable switching hologram. Further, this invention can be utilized not only with visible light but can also be applied to diffusers having operational wavelength ranges that include non-visible parts of the electromagnetic spectrum, such as the ultraviolet (UV) or infrared (IR) region. Such embodiments require a light-sensing device so that a human observer may observe a display by means of a device that converts invisible light to visible light. For example, a pilot wearing night vision goggles can read a display that emits in the IR spectral region, which would be invisible without the goggles. Such a display could have holographic elements and a light source designed to operate in the IR.
The invention described herein can apply to both monochromatic and polychromatic applications, which may exist within both the visible and non-visible portions of the electromagnetic spectrum. The effects of polarization can be especially useful for devices whose operation is based on polarized light; for example in the case of liquid crystal displays or polarization maintaining fiber optic based communication systems.
Alternate embodiments may be devised without departing from the spirit or the scope of the invention.
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A collimated or partially collimated light beam is sent through a substrate matrix of a plurality of nested individual joined geometrically shaped cells wherein each of the cells contains a patterned holographic diffuser or binary optic sheet which produces a transmitted diffused light beam from each of the cells and then superimposes each transmitted diffused light beams from each of the cells to produce a combined resultant diffused light beam. The geometrically shaped cells are clustered in a contiguous arrangement of nested cell subgroups, which are themselves geometrically shaped. When graphed, an angular luminance distribution profile curve with sharply vertical profile slopes at halfpeak points and with a substantially flat and wide peak is resultant which produces a uniform resultant luminance over a wide range of view with a predetermined beam spread and beam deflection angle in relation to a predetermined location of view of the combined resultant diffused light beam.
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BACKGROUND OF INVENTION
1. Field of Invention
This invention relates to marine seismic vibrators and more particularly to supporting structure for the vibrator which provide vibration isolation by attenuating the vibrations emanating at the inertial mass-vibrations that would be transmitted and damage supporting structure and towing structure during operation of the marine seismic vibrator.
2. Prior Art
Over the years many efforts have been made to provide a commercial marine seismic vibrator to utilize in marine operations the advantages offered by land based vibrators.
A typical marine vibrator is illustrated and described in U.S. Pat. No. 3,349,367 issued to S. S. Wisotski. Such vibrators comprise a sonic radiator driven by a hydraulic ram. The hydraulic pressures are derived from a surface source and applied by way of high pressure hoses to the hydraulic ram under control of a servo valve to effect movement of the sonic radiator over a predetermined frequency range. The vibrator is programed through control signals to generate energy in the seismic frequency band between 10 and 190 Hz. In conducting the operations the vibrator output is swept through a range of frequencies as above noted either in an upsweep or downsweep.
The inertial mass for the vibrator is provided by the structure housing the hydraulic ram and sonic radiator. Accordingly the housing such as that shown in FIG. 5 of the aforesaid patent will vibrate at the same frequency as the sonic radiator and these vibrations are transmitted to any structure mounted on the housing, for example, that utilized to connect the marine vibrator to surface supporting and towing means as well as to any equipment mounted to the structure near the vibrator.
The vibrational forces transmitted from the housing to the supporting structure attached thereto are significant. Water is a difficult medium in which to move structured parts. At the higher vibrational frequencies these forces moving the supporting structure in the water will cause the supporting structure literally to tear apart. Efforts at providing adequate supporting structure in view of these forces have in the past taken the form of massive metal components designed to have resonant frequencies outside the operating range of the vibrator. The result has been significant in increase in the weight of the marine vibrator assembly and with unsatisfactory results. These massive elements are torn apart at their juncture after but a few thousand sweeps of the marine transducer due principally to the forces encountered in moving such structure in water at the operating frequencies of the marine vibrator.
Accordingly it is an object of the present invention to provide supporting structure for the marine transducer which will withstand the forces encountered in moving objects at high speed in a body of water and significantly increase the life expectancy of such structures to give rise to a relatively light weight commercially viable marine seismic vibrator.
SUMMARY OF INVENTION
The objects of the present invention are met by providing vibration or acoustic isolation between the inertial mass of the vibrator as represented by the housing and the mechanical supporting structure for the vibrator. This isolation is achieved in accordance with the present invention by providing a low pass mechanical filter located near the upper surface of the housing in series with a high pass filter located above the low pass filter. The combined effect of the serial connected filters is to significantly reduce the transmission of vibrations into the supporting structure and thereby significantly extend the life expectancy of the structure.
More particularly, means are secured to the upper housing of the vibrator to provide for mechanical connection to supporting and towing means at the surface of the water. The means secured to the upper housing comprises at least three acoustic isolators equally spaced about the upper housing. Each of the isolators comprises a pair of spaced mounting pads mechanically secured to the housing. A U-shaped bracket having a base and the depending spaced leg portions is secured to the spaced mounting pads at the free ends of the leg portions by way of a low pass acoustic filter. A rectangular shaped bracket having a base, a top and a pair of spaced vertical side walls is located in part between the spaced leg portions of the U-shaped bracket. Resilient means is mounted to and between the bases of the U-shaped bracket and the rectangular bracket provide a high pass acoustic filter. Means mechanically connected to the top of the rectangular bracket secure all the isolators to a common point at the center of the housing. In the preferred embodiment the acoustic high-pass filter is provided by an airbag, pressurized above atmospheric pressure while the low-pass filter is comprised of rubber bushings each mounted between the ends of the leg portions of the U-shaped bracket and the pair of mounting pads.
Each of the isolator assemblies also includes a stabilizer rod having one end pivotally connected to the upper housing and a second end pivotally connected to one sidewall of the rectangular bracket. The stabilizer rod limits the relative movement between the U-shaped bracket and the rectangular bracket to a substantially vertical direction thus overcoming the horizontal forces exerted against the rectangular bracket during the towing of the marine vibrator.
The leg portions of the U-shaped bracket and the sidewalls of the rectangular bracket are provided with openings which are made as large as possible without significantly weakening the mechanical strength of the brackets in order to maximize the contact between the air bag and the surrounding water thus to reduce cavitation effects on the outer surface of said bag as it expands and contracts in attenuating the low frequency vibrations from the housing.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is top plan view of the housing of the marine seismic vibrator illustrating three isolators of the present invention spaced apart and mounted to the upper surface of the housing;
FIG. 2 is an enlarged top plan view of one of the isolators of FIG. 1;
FIG. 3 is a side plan view taken along line 3--3 of FIG. 2;
FIG. 4 is an end view of an isolator taken along line 4--4 of FIG. 2 and having portions broken away to illustrate the structure of the low-pass acoustic filters;
FIG. 5 is a section taken along line 5--5 of FIG. 2 illustrating the mounting of the high-pass filter within the relatively moveable mounting brackets.
DETAILED DESCRIPTION
Referring now to FIG. 1 wherein isolators 11, 12 and 13, embodying the present invention, are shown mounted in equally spaced relationship one to the other to an upper housing 14 of a marine seismic vibrator. The isolators 11, 12 and 13 are mechanically connected by way of arms 15, 16 and 17 to a common point 18 which provides connection to surface towing and supporting structure (not shown) as well as providing means for supporting other equipment associated with the operation of the marine seismic vibrator such as desurgers in the hydraulic lines supplying high pressure fluid for the operation of the vibrator. Details of a marine vibrator are described in U.S. Pat. No. 3,349,367 issued Oct. 24, 1967 to S. S. Wisotsky. A preferred marine vibrator is described in co-pending application Ser. No. 670,378 filed Nov. 9, 1984 in the name of S. S. Wisotsky and entitled Marine Seismic Source. Both application Ser. No. 670,378 and the present application are assigned to a common assignee and the disclosure of the above copending application is in its entirety incorporated by reference into the present application.
All marine vibrators have in common a sonic radiator driven by a hydraulic ram under control of a servo valve. High pressure hydraulic fluids directed by the servo valve, cause the hydraulic ram to move the sonic radiator back and forth in the surrounding water environment to generate a variable frequency acoustic signal in the seismic range, for example, from 30 to 170 Hz. The vibrations generated by the seismic source are transmitted into the inertial rear mass of the source, which includes the upper housing. The upper housing literally shakes over the range of frequencies generated by the marine source, and these vibrations are coupled to any structure mounted to the upper housing 14. These vibrations cause the structure to move with the upper housing in the water and absent the present invention, such movement in the water environment, at the operating frequencies of the source cause the supporting structure for the source to literally tear apart, particularly at welds and cause connecting bolts to shear. The present invention provides means whereby the vibration or vertical movement of the housing of the source is prevented from transmission through supporting structure, by providing in that supporting structure, vibration isolating characteristics.
Referring now to FIGS. 2 and 3, wherein one of the isolator assemblies of FIG. 1, the isolator assembly 11, is shown enlarged. In as much as the vibrator assemblies are identical the description of one will provide a complete understanding of all. The isolator assembly 11, is comprised of a pair of mounting pads 20 and 21 each secured as by welds to the housing 14. A substantially U-shaped bracket 23 includes a base 24 and two depending spaced leg portions 25 and 26. The free or lower ends 27, 28 of the leg portions are secured to the mounting pads 20 and 21 by way of low-pass acoustic filters 30 and 31.
A rectangular shaped bracket 35 (FIGS. 3 and 4) is fitted between the spaced leg portions 25 and 26 of the U-shaped bracket 23. The rectangular shaped bracket 35 includes a base 36, a pair of spaced vertical sidewalls 37 and a top 38. A resilient means 40 is mounted to and between the bases 24 and 36 respectively of the U-shaped bracket 23 and the rectangular bracket 35. The resilient means 40 provides a high-pass acoustic filter. The resilient means 40 is preferably an air-bag pressurized above atmospheric pressure and shown secured to the base of the U-shaped bracket by way of a bolt 41. As shown, the low-pass filters 30, 31 are connected in series with the high-pass filter provided by air-bag 40 and serve significantly to attenuate vibrations emanating at the housing and prevent the transmission of these vibrations into and through the supporting structure for the source as well as to other equipment associated with the source and mounted to the source.
As best shown in FIG. 4, each low-pass isolator or filter 31 is comprised of a cylinder or bushing preferably of neoprene passing through an aperature 45 in the mounting pad 21. The bushing is secured between the mounting pad 21 and the base 36 of the U-shaped bracket by an assembly including a bolt 46, washer 47 and nut 48. Upon tightening the nut 48 on the bolt 46, the bushing 45 is squeezed between the lower portion of the base 36 and the washer 47 to assume the shape illustrated. The low-pass filter 31 including the bushing 45 severely attenuates high frequency vibrations emanating from the housing 14 while at that same time providing a reliable mount for the source.
The high-pass filter, comprised of air-bag 40 is best illustrated in FIG. 5 where the air-bag is shown connected at its upper portion by way of bolt 41 to the base 24 of the U-shaped bracket 23 the lower portion of the air-bag 40 includes a conduit 50 passing through an aperature 51 and terminating in a petcock valve 52. The conduit 50 passing through the aperature in close fitting relation prevents lateral movement between the bottom of the air-bag 40 and the base 36 of the rectangular shaped bracket. The petcocks valve 52 for each of the air-bags 40 are connected to a common source of compressed air (not shown). Each of the airbags is equally charged with compressed air at approximately 40 PSI by opening each of the petcocks to the common source to assure equal pressures to each of the air-bags 40 and upon attaining the desired pressure the petcock valves 52 are closed. The air-bag has a natural frequency of 1.25 Hz and provides an excellent filter for significantly attenuating the low frequency vibrations generated at the housing 14.
Those parts of the brackets 26 and 35 opposite the sidewalls of the air-bag 40 have portions removed providing holes which couple the air-bag to the surrounding water outside the brackets. For example, hole 60 is formed in the leg portion 26 of the bracket 23 and holes 61 and 62 are formed in the sidewalls 37 of the bracket 35. These holes are made as large as possible without significantly weakening the structural strength required of the brackets in supporting the weight of the source. The air-bag in an operating mode will expand and contract laterally in dampening or attenuating the low frequency vibrations from the housing. The increased coupling to the surrounding water afforded by the various aperature or holes 60-62 significantly reduce cavitation effects on the outer surface of the air-bag to increase the useful life of the air-bag.
The downward movement of the U-shaped bracket 23 is limited by a stop mechanism afforded by ears or extension 65 integral with the base 24 of the bracket 23 and extending into the aperatures 61 of the rectangular shaped bracket 35. The ears or extensions 65 will contact the upper surface of the webs 67 limiting the downward movement of the U-shaped bracket 23 and thus limiting the amount of compressive force applied to the air-bag 40. When the air-bag is in an operating mode with the marine source immersed in water the displacement of the source will cause the extension 65 to ride in the slots or openings 61 in a position approximately as illustrated in FIG. 5. However, as the source is withdrawn from the water the effective weight of the source and associated equipment will be increased causing the extension 65 to engage the upper surface of the web 67 thus limiting the compressive forces on the air-bag 40 and avoiding damage thereto.
As the marine source is towed through the water, lateral forces will be applied to the supporting structure and particularly to the rectangular bracket 35. Such forces would tend to cause the rectangular bracket 35 to shift from its normal vertical position. In order to avoid the effects such an attitude of the rectangular bracket would have upon the operability of the air-bag, there is provided a stabilizer assembly including stabilizer rod 70 having one end pivotally connected to the housing 14 by the way of a mounting pad 71. The opposite or free end of the rod 70 is pivotally connected to the rectangular bracket 35 by way of mounting structure 72. The pivotal connection for opposite ends of the stabilizer arm or rod are identical and comprise a hub 73 positioned between spaced arms 74 of the mounting pad 71. The hub 73 is secured to the spaced arms 74 by way of a bolt and nut assembly 75 passing through a bushing comprised of an inner annular metal cylinder 80 and an outer annular metal cylinder 81. Filling the annulus between the cylinders 80, 81 is a cylinder of neoprene which functions as a low-pass filter attenuating the high frequency vibrations generated at the housing 14 and preventing their transmission to the other structural parts of the mounting assembly. The hub 73 is connected to the stabilizer rod 70 by way of a split cylinder 85. The length of the stabilizer assembly is thereby adjustable by moving the rod 70 within the split cylinder 85. When the desired adjustment has been completed the position between the cylinder 85 and the rod 70 is locked in place by a clamp 86. Similar connections are made at the free end of the rod 70.
The stabilizer rod assembly will control the movement of the rectangular bracket 35 and limit it to a substantially vertical movement thereby avoiding distortion of the air-bag 40. It will be noted particularly in FIG. 2 that the structure connecting the stabilizer rod assembly to the sidewall of the rectangular bracket 35 includes a plate 90 having central portion 91 removed again to increase the coupling between the air-bag 40 and the surrounding water.
Now having described the invention, and the preferred embodiment thereof, other modifications will become apparent to those skilled in the art and it is intended to cover such modifications as fall within the scope of the appended claims.
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Mounting structure for a marine seismic vibrator comprising at least three acoustic isolators equally spaced apart about an upper housing of the vibrator. Each of the isolators comprises a pair of spaced mounting pads mechanically secured to the housing. A U-shaped bracket having a base and depending spaced leg portions is attached to the mounting pads by way of a low-pass acoustic filter. A rectangular shaped bracket has a base, a top and a pair of spaced vertical sidewalls. The rectangular shaped bracket is located between the spaced leg portions of the U-shaped bracket and a resilient means is mounted between the bases of the U-shaped bracket and the rectangular bracket to provide a high-pass acoustic filter. Means mechanically connected to the top of the rectangular brackets to the tops of the mechanical brackets secure all the isolators to a common point at the center of the housing.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is the US National Stage of International Application No. PCT/EP2005/050769, filed Feb. 23, 2005 and claims the benefits of German Patent application No. 10 2004 016 943.8 filed Apr. 6, 2004. All of the applications are incorporated by reference herein in their entirety.
FIELD OF THE INVENTION
[0002] The invention relates to a method for controlling a fuel supplying device of an internal combustion engine, the fuel supplying device comprising a low-pressure circuit, a high-pressure pump that is coupled to the low-pressure circuit at the input side and conveys the fuel into a fuel accumulator, a volume flow control valve associated with the high-pressure pump, and an electromechanical pressure regulator that is actively connected to the fuel accumulator and the low-pressure circuit and can stop the flow of fuel from the fuel accumulator into the low-pressure circuit.
BACKGROUND OF THE INVENTION
[0003] High demands are made on internal combustion engines, in particular in motor vehicles. The pollutant emissions are subject to legal regulations and the customer demands low fuel consumption, safe and reliable operation and low maintenance costs. The fuel supplying device of the internal combustion engine has a strong influence on whether the demands may be met.
[0004] DE 199 16 101 A1 discloses a method and a device for controlling an internal combustion engine. A high-pressure pump conveys fuel from a low-pressure region into a fuel accumulator. An actual value of a fuel pressure in the fuel accumulator is detected. In a first operating state the high-pressure pump is controlled as an actuator to adjust the fuel pressure in the fuel accumulator. In a second operating state a pressure relief valve is controlled as an actuator to discharge fuel from the fuel accumulator into the low-pressure region to adjust the fuel pressure. In the first operating state a control deviation between a desired value of the fuel pressure and the actual value of the fuel pressure is supplied to a first regulator. In the second operating state the control deviation is supplied to a second regulator. The first regulator is only used if the control deviation is positive. The second regulator is only used if the control deviation is negative. A switch takes place between the first operating state and the second operating state if the respectively active regulator reaches a zero control point and the control deviation is greater than a first threshold or the control deviation is less than a second threshold.
[0005] A method for operating an internal combustion engine is also disclosed in WO 2004/104397 A1 in which, in a first operating mode, a fuel pressure in a fuel accumulator is regulated to a desired pressure by adjusting a flow of fuel from fuel supplied to the high-pressure pump as a function of a volume of fuel to be injected and the desired pressure, and in which, in a second operating mode, with a specified flow of fuel, the fuel pressure is regulated to the desired value by discharging fuel from the fuel accumulator. The second operating mode is adopted if the flow of fuel falls below a first flow of fuel and the first operating mode is adopted if the flow of fuel exceeds a second flow of fuel.
SUMMARY OF THE INVENTION
[0006] The object underlying the invention is therefore to provide a method which allows reliable and safe operation of fuel supplying devices in internal combustion engines.
[0007] The object is achieved by the features of the independent claims. Advantageous developments of the invention are identified in the subclaims.
[0008] The invention is characterized by a method for controlling a fuel supplying device of an internal combustion engine, the fuel supplying device comprising a low-pressure circuit, a high-pressure pump that is coupled to the low-pressure circuit at the input side and conveys the fuel into a fuel accumulator, a volume flow control valve associated with the high-pressure pump, and an electromechanical pressure regulator that is actively connected to the fuel accumulator and the low-pressure circuit and can stop the flow of fuel from the fuel accumulator into the low-pressure circuit. In the method a control deviation is determined from a difference between a specified fuel pressure and a detected fuel pressure. In a first operating mode a regulating signal for the volume flow control valve is generated by means of a first regulator, the control deviation being supplied to the first regulator. In a second operating mode a regulating signal for the electromechanical pressure regulator is generated by means of a second regulator, the control deviation being supplied to the second regulator. There is a switch from the first operating mode to the second operating mode if the detected fuel pressure is greater than the specified fuel pressure by a first specified amount or a first specified factor. There is also a switch from the first operating mode to the second operating mode as a function of a delivery flow of the high-pressure pump, if the delivery flow of the high-pressure pump is less than a lower switch-over threshold of the delivery flow, and there is a switch from the second operating mode to the first operating mode if the delivery flow of the high-pressure pump is greater than an upper switch-over threshold of the delivery flow.
[0009] The method has the advantage that an excessive fuel pressure in the fuel accumulator may be avoided and a pressure relief valve, which may be provided on the fuel accumulator and discharges fuel from the fuel accumulator before the fuel pressure in the fuel accumulator become so great that the fuel supplying device could be damaged thereby, is protected from damage. A further advantage is that tolerances or defects in fuel supplying device components may be compensated which could otherwise cause incorrect fuel pressures in the fuel accumulator. Safe and reliable operation of the fuel supplying device is made possible thereby. It may also easily be ensured that the specified fuel pressure may be attained. This method is particularly efficient as only as much fuel is conveyed into the fuel accumulator by the high-pressure pump as is required for adjusting or maintaining the fuel pressure in the fuel accumulator.
[0010] A switch is advantageously made from the second operating mode to the first operating mode if the detected fuel pressure is less than the specified fuel pressure by a second specified amount or a second specified factor. This has the advantage that an insufficient fuel pressure in the fuel accumulator, which may lead to inadequate dosing of fuel into the cylinders of the internal combustion engine, may be avoided.
[0011] The invention is also characterized by a method for controlling a fuel supplying device of an internal combustion engine, the fuel supplying device comprising a low-pressure circuit, a high-pressure pump that is coupled to the low-pressure circuit at the input side and conveys the fuel into a fuel accumulator, a volume flow control valve associated with the high-pressure pump, and an electromechanical pressure regulator that is actively connected to the fuel accumulator and the low-pressure circuit and can stop the flow of fuel from the fuel accumulator into the low-pressure circuit. In the method a control deviation is determined from a difference between a specified fuel pressure and a detected fuel pressure. In a first operating mode a regulating signal for the volume flow control valve is generated by means of a first regulator, the control deviation being supplied to the first regulator. In a second operating mode a regulating signal for the electromechanical pressure regulator is generated by means of a second regulator, the control deviation being supplied to the second regulator. There is a switch from the second operating mode to the first operating mode if the detected fuel pressure is less than the specified fuel pressure by a second specified amount or a second specified factor. There is also a switch from the first operating mode to the second operating mode as a function of a delivery flow of the high-pressure pump, if the delivery flow of the high-pressure pump is less than a lower switch-over threshold of the delivery flow, and there is a switch from the second operating mode to the first operating mode if the delivery flow of the high-pressure pump is greater than an upper switch-over threshold of the delivery flow.
[0012] This method has the advantage that an insufficient fuel pressure in the fuel accumulator, which may lead to inadequate dosing of fuel into the cylinders of the internal combustion engine, may be avoided. The method also has the advantage that tolerances and defects in fuel supplying device components may be compensated. This makes safe and reliable operation of the fuel supplying device possible. It may also easily be ensured that the specified fuel pressure may be attained. This method is particularly efficient as only as much fuel is conveyed into the fuel accumulator by the high-pressure pump as is required for adjusting or maintaining the fuel pressure in the fuel accumulator.
[0013] The lower switch-over threshold of the delivery flow and the upper switch-over threshold of the delivery flow are advantageously determined from an error value of the flow of fuel which results from a leakage flow through the volume flow control valve in its closed position and a leakage flow from the fuel accumulator if the electromechanical pressure regulator is closed and no fuel is to be dosed. The fuel supplying device may be operated more efficiently if the error value of the flow of fuel is known and taken into account for control of the fuel supplying device. By taking into account the error value of the flow of fuel, tolerances and defects in fuel supplying device components and the leakage flow of the volume flow control valve may be compensated and hence reliable operation of the fuel supplying device may be ensured.
[0014] In a preferred development the error value of the flow of fuel is determined as a function of at least two fuel pressures, detected at an interval, which are detected in a third operating mode in which no fuel is to be dosed and the volume flow control valve and the electromechanical pressure regulator are controlled in such a way that the volume flow control valve and the electromechanical pressure regulator are closed. Very precise measurement of the error value of the flow of fuel is thus possible.
[0015] To determine the error value of the flow of fuel, the fuel pressure in the fuel accumulator is advantageously regulated to a first specified fuel pressure, so the control deviation is less than a specified threshold value, a first fuel pressure is detected, a third operating mode is adjusted and the operating mode switch-over is blocked, a second fuel pressure is detected, and the error value of the flow of fuel is determined as a function of a time and a difference between the second detected fuel pressure and the first detected fuel pressure. This method makes it possible to determine the leakage flow very easily.
[0016] The second fuel pressure is advantageously detected if the fuel pressure in the fuel accumulator is greater than or equal to a second specified fuel pressure, of which the value is greater than that of the first specified fuel pressure. This method is particularly efficient if the leakage flow of the volume flow control valve is very high and the fuel pressure in the fuel accumulator is rapidly increasing.
[0017] In a further advantageous embodiment the second fuel pressure is detected after a specified time has elapsed. This method is efficient if the leakage flow of the volume flow control valve is low or if there are leakages in the fuel supplying device, so the fuel pressure in the fuel accumulator increases only very slowly or potentially decreases.
[0018] A preferred development is characterized in that following a switch from the first operating mode to the second operating mode or from the second operating mode to the first operating mode, switch-over of the operating mode is blocked for at least one specified blocking time. This has the advantage that instable operating states as a result of frequent switching between operating modes may be avoided.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Exemplary embodiments of the invention are described hereinafter with reference to the schematic drawings, in which:
[0020] FIG. 1 shows an internal combustion engine comprising a fuel supplying device,
[0021] FIG. 2 shows a combination valve comprising a volume flow control valve and an electromechanical pressure regulator with a common actuator,
[0022] FIG. 3 shows the characteristic of the combination valve of FIG. 2 ,
[0023] FIG. 4 shows the block diagram of a regulating device for regulating the fuel pressure in a fuel accumulator,
[0024] FIG. 5 shows a flow diagram for controlling the switch-over of fuel supplying device operating states, and
[0025] FIG. 6 shows a flow diagram for determining the error value of the flow of fuel.
[0026] Elements which have the same construction and function are provided with the same reference numerals in all figures.
DETAILED DESCRIPTION OF THE INVENTION
[0027] An internal combustion engine ( FIG. 1 ) comprises an intake duct 1 , a motor unit 2 , a cylinder head 3 and an exhaust gas duct 4 . The motor block 2 comprises a plurality of cylinders which have pistons and connecting rods via which they are coupled to a crankshaft 21 .
[0028] The cylinder head 3 comprises a valve train assembly comprising a gas inlet valve, a gas outlet valve and valve operating mechanisms. The cylinder head 3 also comprises an injection valve 34 and a spark plug.
[0029] A supplying device 5 for fuel is also provided. This comprises a fuel tank 50 which is connected via a first fuel line to a low-pressure pump 51 . The fuel line ends in a swirl pot 50 a . At the output side the low-pressure pump 51 is actively connected to an admission 53 of a high-pressure pump 54 . A mechanical regulator 52 , which is connected at the output-side to the fuel tank 50 via an additional fuel line, is also provided at the output-side of the low-pressure pump 51 . The low-pressure pump 51 , the mechanical regulator 52 , the fuel line, the additional fuel line and the admission 53 form a low-pressure circuit.
[0030] The low-pressure pump 51 is preferably configured in such a way that during operation of the internal combustion engine it always supplies an adequate volume of fuel to ensure that a specified low pressure is not fallen below.
[0031] The admission 53 is guided to the high-pressure pump 54 which at the output side conveys the fuel toward a fuel accumulator 55 . The high-pressure pump 54 is usually driven by the camshaft and thus conveys a constant volume of fuel into the fuel accumulator 55 with a constant speed of the crankshaft 21 .
[0032] The injection valves 34 are actively connected to the fuel accumulator 55 . The fuel is thus supplied to the injection valves 34 via the fuel accumulator 55 .
[0033] In the approach of the high-pressure pump 54 , i.e. upstream of the high-pressure pump 54 , a volume flow control valve 56 is provided by means of which the volume flow that is supplied to the high-pressure pump 54 may be adjusted. A specified fuel pressure FUP_SP in the fuel accumulator 55 can be adjusted by corresponding control of the volume flow control valve 56 .
[0034] The fuel supplying device 5 is also provided with an electromagnetic pressure regulator 57 at the output side of the fuel accumulator 55 and with a return line into the low-pressure circuit. If a fuel pressure in the fuel accumulator 55 is greater than the fuel pressure FUP_SP specified by corresponding control of the electromechanical pressure regulator 57 , the electromechanical pressure regulator 57 opens and fuel is discharged from the fuel accumulator 55 into the low-pressure circuit.
[0035] Alternatively the volume flow control valve 56 may also be integrated in the high-pressure pump 54 or the electromechanical pressure regulator 57 and the volume flow control valve 56 are adjusted via a common actuator, as is illustrated by way of example in FIG. 2 and described in more detail below.
[0036] The internal combustion engine is associated with a control device 6 which is in turn associated with sensors which detect various measured quantities and determine the measured value of the measured quantities in each case. As a function of at least one of the measured quantities the control device 6 determines regulating variables which are then converted into corresponding regulating signals to control actuators by means of corresponding final controlling elements.
[0037] The sensors are for example a pedal position sensor which detects the position of an accelerator pedal, a crankshaft angle sensor which detects a crankshaft angle and with which a motor speed is then associated, an airflow measuring device and a fuel pressure sensor 58 which detects a fuel pressure FUP_AV in the fuel accumulator 55 . Any desired subset of sensors or additional sensors may be present depending on the embodiment of the invention.
[0038] The actuators are constructed for example as gas inlet or gas outlet valves, injection valves 34 , a spark plug, throttle valve, low-pressure pump 51 , volume flow control valve 56 or as an electromechanical pressure regulator 57 .
[0039] The internal combustion engine preferably also has additional cylinders with which appropriate final controlling elements are then associated.
[0040] FIG. 2 shows a combination valve 7 comprising an actuator 70 , the volume flow control valve 56 and the electromechanical pressure regulator 57 . The combination valve 7 has an outlet 71 which is actively connected to the inlet of the high-pressure pump 54 , a connector 72 which is actively connected to the admission 53 and an inlet 73 which is actively connected to the fuel accumulator 55 . The volume flow control valve 56 comprises the connector 72 , the outlet 71 , a valve positioner 74 and the actuator 70 . The electromechanical pressure regulator 57 comprises the inlet 73 , the connector 72 , the valve positioner 74 , a spring 75 , a valve cap 76 and the actuator 70 .
[0041] The actuator 70 moves the valve positioner 74 in the axial direction as a function of a regulating signal PWM. The spring 75 is arranged between the valve positioner 74 and the valve cap 76 and pre-stressed as a function of the axial position of the valve positioner 74 . The valve positioner 74 is constructed in such a way that in the region of a first axial displacement of the valve positioner 74 in the direction of the spring 75 , starting form its axial position in which it is pressed by the spring 75 , without loading of the actuator 70 with the regulating signal PWM, the flow of fuel is substantially cut off. In this state only a leakage flow flows from the connector 72 to the outlet 71 . In the region of a second axial displacement of the valve positioner 74 by corresponding loading of the actuator 70 with the regulating signal PWM the connector 72 is hydraulically coupled to the outlet 71 . In the second region of the axial displacement of the valve positioner 74 a volume flow of a different magnitude can flow from the admission 53 into the connector 72 toward the outlet 71 and to the high-pressure pump 54 as a function of the regulating signal PWM.
[0042] If the force caused by the fuel pressure in the fuel accumulator 55 is greater than the force caused by the pre-stressing of the spring and exerted on the valve cap 76 , the inlet 73 is hydraulically coupled to the connector 72 , so fuel can flow from the fuel accumulator 55 into the inlet 73 toward the outlet 72 into the admission 53 .
[0043] The fuel pressure in the fuel accumulator 55 , which is at least required to open the electromechanical pressure regulator, can be adjusted by increasing or reducing the regulating signal PWM. The actuator 70 increases or reduces the force accordingly which acts via the valve positioner 74 on the spring 75 and pre-stresses the spring 75 . The force caused by prestressing of the spring 75 closes the electromechanical pressure regulator if the force exerted on the valve cap 76 by the fuel pressure in the fuel accumulator 55 is smaller.
[0044] FIG. 3 shows characteristics of the combination valve 7 illustrated in FIG. 2 . A pressure curve 80 shows the connection between the regulating signal PWM in amps and the fuel pressure in the fuel accumulator 55 in bar. If with the given regulating signal PWM the fuel pressure in the fuel accumulator 55 is increased beyond the value specified by the pressure curve 80 , the electromechanical pressure regulator 57 opens and reduces the fuel pressure in the fuel accumulator 55 by discharging fuel from the fuel accumulator 55 into the admission 53 .
[0045] For values of the regulating signal PWM that are greater than a threshold value, which in this embodiment has a value of about 0.5 amp, the volume flow control valve 56 opens and allows a flow of fuel given in liters per minute. The graph shows an upper flow curve 81 which represents an upper tolerance limit for the combination valve 7 , a lower flow curve 82 which represents a lower tolerance limit for the combination valve 7 , and a middle flow curve 83 which represents the average value between upper and lower flow curves. The flow curves 81 , 82 and 83 show that in this embodiment the leakage flow may still flow below the threshold value, i.e. if the volume flow control valve 56 is substantially closed.
[0046] FIG. 4 shows a block diagram of a regulating device which may be used for regulating the fuel pressure in the fuel supplying device 5 and comprises a combination valve 7 , as is described by way of example in FIG. 2 . The fuel pressure in the fuel accumulator 55 is regulated as a function of the current operating mode of the fuel supplying device 5 .
[0047] In a first operating mode the fuel pressure in the fuel accumulator 55 is adjusted as a function of the volume of fuel conveyed by the high-pressure pump 54 . The volume flow control valve 56 is open and the conveyed volume of fuel is dependent on the control of the volume flow control valve 56 . In this operating mode the electromechanical pressure regulator 57 is closed. If more fuel is conveyed into the fuel accumulator 55 than is appropriate the fuel pressure in the fuel accumulator 55 increases. If less fuel is conveyed into the fuel accumulator 55 than is appropriate the fuel pressure in the fuel accumulator 55 sinks accordingly. This first operating mode is called volume control VC.
[0048] In a second operating mode the volume flow control valve 56 is closed. Only the leakage flow flows through the volume flow control valve 56 . If the electromechanical pressure regulator 57 is closed and less fuel is dosed than is conveyed into the fuel accumulator 55 than via the leakage flow, the fuel pressure in the fuel accumulator 55 increases until the electromechanical pressure regulator 57 opens and the flow of fuel into the admission 53 is stopped. The fuel pressure in the fuel accumulator 55 is consequently limited to the fuel pressure specified by the electromechanical pressure regulator 57 . This second operating mode is therefore called pressure control PC.
[0049] FIG. 4 shows two control circuits which can be switched between by means of a switch LV_MS as a function of the currently adjusted operating mode of the fuel supplying device 5 . If the currently adjusted operating mode is the first operating mode, i.e. volume control VC, the switch LV_MS is then in the position VC. If the currently adjusted operating mode is the second operating mode, i.e. pressure control PC, then the switch LV_MS is in the position PC.
[0050] A control deviation FUP_DIF is determined from the difference between the specified fuel pressure FUP_SP and the detected fuel pressure FUP_AV. The control deviation FUP_DIF is supplied to a regulator in block B 1 in the case of volume control VC. This regulator is preferably constructed as a PI regulator. A regulator value FUEL_MASS_FB_CTRL of the first regulator is determined in block B 1 . A pre-control value FUEL_MASS_PRE of the mass of fuel to be conveyed is determined in block B 2 as a function of the specified fuel pressure FUP_SP and the detected fuel pressure FUP_AV. The pre-control value FUEL_MASS_PRE of the mass of fuel to be conveyed, the regulator value FUEL_MASS_FB_CTRL of the first regulator and the mass of fuel MFF to be injected and an adaptation value FUL_MASS_ADAPT are added up to give a mass of fuel to be conveyed FUEL_MASS_REQ. In the case of volume control VC a regulating signal PWM_VC is determined in a block B 3 as a function of the mass of fuel to be conveyed FUEL_MASS REQ. Block B 3 preferably comprises performance data. A block B 4 represents the fuel supplying device 5 illustrated in FIG. 1 with the combination valve 7 shown in FIG. 2 . The regulating signal PWM, which in the case of volume control VC is the same as the regulating signal PWM_VC, is the input variable of block B 4 . The output variable of block B 4 is the detected fuel pressure FUP_AV which is detected for example by means of the fuel pressure sensor 58 .
[0051] In the case of pressure control PC, the control deviation FUP_DIF is supplied to a second regulator in a block B 5 . The regulator in block B 5 preferably constructed as a PI regulator. In a block B 6 a pre-control value PWM_PRE for a regulating signal PWM_PC in the case of pressure control PC is determined as a function of the specified fuel pressure FUP_SP, to which is added a regulator value PWM_FB_CTRL of the second regulator determined in block B 5 . The total is the regulating signal PWM_PC in the case of pressure control PC. In the case of pressure control PC the regulating signal PWM is the same as the regulating signal PWM_PC in the case of pressure control PC. The block B 6 preferably comprises performance data.
[0052] The adaptation value FUEL_MASS_ADAPT is determined in block B 7 as a function of a regulator state of the first regulator in block B 1 . For example a value of an integral fraction of the first regulator may be reduced by a value and the adaptation value corrected as a function of this value if a specified operating condition, for example a stationary operating state, exists.
[0053] The performance data of blocks B 3 and B 6 are preferably determined in advance by way of experiments on an engine test stand, simulations or road trials. Alternatively functions based on physical models may also be used for example.
[0054] The block diagram shown in FIG. 4 is a preferred embodiment of a regulating device for a fuel supplying device 5 , comprising a combination valve 7 according to FIG. 2 and characteristics according to FIG. 3 . If the volume flow control valve 56 and the electromechanical pressure regulator 57 each have their own actuator however, the regulating signal PWM_VC acts on the actuator of the volume flow control valve 56 in the case of volume control VC and the regulating signal PWM_PC acts on the actuator of the electromechanical pressure regulator 57 in the case of pressure control PC. Consequently both the regulating signal PWM_VC in the case of volume control VC and the regulating signal PWM_PC in the case of pressure control PC are supplied to block B 4 instead of the common regulating signal PWM. The control circuits for the first and second operating modes preferably operate simultaneously in this case, so the switch LV_MS shown in FIG. 4 may be omitted. The control deviation FUP_DIF is supplied to blocks B 1 and B 5 simultaneously.
[0055] FIG. 5 shows a flow diagram illustrating control of the operating mode switch-over of the fuel supplying device 5 . Processing starts with step S 1 which is preferably executed when the internal combustion engine starts. Step S 1 may include additional steps, not shown here, such as initialization of variables to establish a defined initial state of the fuel supplying device 5 .
[0056] A check is carried out in step S 2 as to whether a difference between a current time t and a time t_MS of the last operating mode switch-over is greater than a blocking time T_MS_WAIT. If this condition is not satisfied step S 2 is repeated after a waiting time T_W. Since the last operating mode switch-over therefore at least the blocking time T_MS_WAIT must have elapsed before the operating mode can be switched again. If the condition is satisfied in step S 2 however, processing continues in step S 3 .
[0057] In step S 3 both an error value FUP_ERR of the fuel pressure and a delivery flow MFF_PUMP of the high-pressure pump 54 are checked. The error value FUP_ERR of the fuel pressure is dependant on a value or a factor by which the detected fuel pressure FUP_AV is greater or less than the specified fuel pressure FUP_SP and is defined in this embodiment such that the error value FUP_ERR of the fuel pressure is greater if the specified fuel pressure FUP_SP is greater than the detected fuel pressure FUP_AV, as if the specified fuel pressure FUP_SP is less than the detected fuel pressure FUP_AV. The error value FUP_ERR of the fuel pressure is for example a quotient from the specified fuel pressure FUP_SP and the detected fuel pressure FUP_AV or the difference between the specified fuel pressure FUP_SP and the detected fuel pressure FUP_AV. If the error value FUP_ERR of the fuel pressure is less than a specified lower tolerance limit FUP_ERR_BOL for the error value FUP_ERR of the fuel pressure or if the error value FUP_ERR of the fuel pressure is greater than or equal to the specified lower tolerance limit FUP_ERR_BOL for the error value FUP_ERR of the fuel pressure and less than or equal to a specified upper tolerance limit FUP_ERR_TOL for the error value FUP_ERR of the fuel pressure, and if the delivery flow MFF_PUMP of the high-pressure pump 54 is simultaneously less than a lower switch-over threshold MFF_PUMP_BOL of the delivery flow MFF_PUMP of the high-pressure pump 54 , processing continues in step S 4 in which the operating mode of the fuel supplying device 5 is switched to pressure-control mode PC. If the condition is not satisfied in step S 3 , step S 5 is carried out.
[0058] The error value FUP_ERR of the fuel pressure and the delivery flow MFF_PUMP of the high-pressure pump 54 are again checked in step S 5 . If the error value FUP_ERR of the fuel pressure is greater than a specified upper tolerance limit FUP_ERR_TOL for the error value FUP_ERR of the fuel pressure or if the error value FUP_ERR of the fuel pressure is greater than or equal to the specified lower tolerance limit FUP_ERR_BOL for the error value FUP_ERR of the fuel pressure and less than or equal to the specified upper tolerance limit FUP_ERR_TOL for the error value FUP_ERR of the fuel pressure and if the delivery flow MFF_PUMP of the high-pressure pump 54 is simultaneously greater than an upper switch-over threshold MFF_PUMP_TOL of the delivery flow MFF_UMP of the high-pressure pump 54 , processing continues in step S 6 in which the operating mode of the fuel supplying device 5 is switched to volume-control mode VC. If the condition is not satisfied in step S 5 , processing continues with step S 2 following a waiting time T_W.
[0059] After switching over the operating mode in step S 4 or step S 6 , step S 7 is in each case carried out in which the current time t is stored as the time of the last operating mode switchover t_MS if a switch was made before from the first operating mode to the second operating mode or from the second operating mode to the first operating mode. Following step S 7 processing continues, again after a waiting time T_W, in step S 2 .
[0060] The lower switch-over threshold MFF_PUMP_BOL and the upper switch-over threshold MFF_PMP_TOL of the delivery flow MFF_PUMP of the high-pressure pump 54 may be determined as a function of the leakage flow of the volume flow control valve 56 and a possible leakage flow from the fuel accumulator 55 , so tolerances and potential errors and defects in components of the fuel supplying device 5 may be compensated, so the high-pressure pump 54 needs convey only as little fuel as possible, but as much fuel as is necessary, into the fuel accumulator 55 .
[0061] FIG. 6 shows a flow diagram showing the steps for determining an error value Q_ERR of the flow of fuel in the fuel supplying device 5 . Processing starts with step S 1 which is preferably executed if the internal combustion engine is in coasting mode, in other words if the crankshaft 21 is turning without fuel being dosed. Step S 11 may also include additional preparatory steps, not shown here. A first fuel pressure FUP_SP 1 is set in step S 12 . The first fuel pressure FUP_SP 1 is preferably less than the current fuel pressure in the fuel accumulator 55 . Once the first fuel pressure FUP_SP 1 is set such that the amount of the control deviation FUP_DIF is less than a specified threshold value a first fuel pressure FUP_SV 1 and a first time t 1 are detected in step S 13 . A third operating mode of the fuel supplying device 5 is subsequently set in step S 14 and the operating mode is simultaneously prevented from being automatically switched.
[0062] In the third operating mode all valves of the fuel supplying device 5 are controlled in such a way that they are closed.
[0063] This operating mode can be set for example in that a switch is made to pressure-control mode PC and at the same time the specified fuel pressure FUP_SP is set to a value that is large enough for the electromechanical pressure regulator 57 to be closed. In the pressure control mode PC the volume flow control valve 56 is controlled in such a way that it is closed. The injection valves 34 are also controlled in such a way that they are closed as no fuel is to be dosed. Changes in the fuel pressure in the fuel accumulator 55 can therefore only be caused as a result of the leakage flow of the volume flow control valve 56 or by the possible leakage flow from the fuel accumulator 55 .
[0064] There is a wait in step S 15 until the fuel pressure in the fuel accumulator is greater than or equal to a second specified fuel pressure FUP_SP 2 or until a specified time has elapsed. A second fuel pressure FUP_AV 2 and a second time t 2 are detected in step S 16 . A difference FUP_AV_DIF between the second detected fuel pressure FUP_AV 2 and the first detected fuel pressure FUP_AV 1 and a time T from the second time t 2 and the first time t 1 are determined in step S 17 . The error value Q_ERR of the flow of fuel is determined as a function of the difference FUP_AV_DIF of the detected fuel pressures and time T. The error value Q_ERR of the flow of fuel may also be determined as a function of a volume V_RAIL of the fuel accumulator 55 , a fuel density r and a fuel compressibility b. The error value Q_ERR of the flow of fuel represents the balance of the inflows of fuel into the fuel accumulator 55 and the fuel discharges from the fuel accumulator 55 if all valves of the valve supplying device 5 are controlled in such a way that the valves should be closed.
[0065] The third operating mode is switched off in step S 18 and there is a switch to the operating mode switch-over described in FIG. 5 . The identified error value Q_ERR of the flow of fuel may, preferably following a check for possible errors and defects in the fuel supplying device 5 , be incorporated into control of the fuel supplying device 5 . The identified error value Q_ERR in the flow of fuel can therefore be taken into account during continued operation of the fuel supplying device 5 .
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Disclosed is a fuel supplying device of an internal combustion engine, comprising a low-pressure circuit, a high-pressure pump coupled to the low-pressure circuit and conveys fuel into a fuel reservoir, a volume flow control valve assigned to the high-pressure pump, an electromechanical pressure regulator connected to the fuel reservoir and the low-pressure circuit and can direct fuel from the fuel reservoir into the low-pressure circuit, a regulating mechanism which generates an actuation signal for the volume flow control valve by a first controller in a first mode which generating an actuation signal for the electromechanical pressure regulator with the aid of a second controller in a second mode. The mode of the fuel supplying mechanism is switched in accordance with a fuel pressure error value resulting from a detected fuel pressure and a predefined fuel pressure. The mode can additionally be switched according to the throughput of the high-pressure pump.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to multi-cylinder internal combustion engines and more specifically to an induction system for such an engine which enables good inertia supercharging during both high and low engine speed operation.
2. Description of the Prior Art
FIG. 1 of the drawings shows an induction arrangement disclosed in Japanese Patent Application First Provisional Publication No. 56-115818. This arrangement as shown, comprises a single elongate collector 10 which communicates with a surge tank 12 via first and second interconnecting induction conduits 13, 14. Each of the engine cylinders #1 to #6 communicate with the collector 10 via branch runners 15a-15f. A valve 16 is disposed in the collector 10 so as to divide the same into first and second sections 10A, 10B. The first section 10A communicates with a first group of engine cylinders #1 to #3 while the second section 10B communicates with the remaining cylinders #4 to #6. When the engine is operating at low speed valve 16 is closed.
The ignition order of the first and second groups of cylinders are respectively discontinuous. Accordingly, when the engine is operating at low engine speed and the valve 16 is closed the first and second groups of cylinders aspirate through mutually independent induction systems. The dimensions of the conduiting etc., of the induction arrangement is selected so that resonance characteristics of the two "quasi" independent systems are such as to coincide with the induction pressure pulsations under low engine speed condition and thus induce good inertia ram charging (supercharging). Upon the engine speed exceeding a predetermined level valve 16 opens and induces the situation wherein the natural frequency of the single enlarged system under such conditions matches the induction pressure pulstations which occur at this time.
However, this arrangement encounters the drawback in that although the system is relatively simple, upon opening of valve 16 the charging effect provided in branch runners 15c and 15d which are located close to the valve and the charging effect provided at branch runners 15a and 15f (remote from valve 16) are not the same. Accordingly, charging efficiency varies from one cylinder to another and optimal engine performance is not obtained.
Further examples of the above type of induction system are found in Japanese Patent Utility Model First Prov. Pub. No. 58-129063 and Japanese Patent Utility Model Second Prov. Pub. No. 46-21123.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an induction system which provides good inertia supercharging characteristics under both high and low engine speed operations and wherein the variation in supercharging effect between cylinders is minimized in a manner which improves engine performance under both modes.
In brief, the above object is achieved by an arrangement wherein the cylinders of the engine are divided into first and second groups or banks wherein the ignition sequence of the respective groups is discontinuous; and wherein the induction system for supplying air to the first and second group of cylinders is characterized by: a first elongate collector section with which the first group of cylinders fluidly communicate via branch runners, the first collector section having first and second ends; a second elongate collector section fluidly discrete from the first collector section and with which the second group of cylinders fluidly communicate via branch runners, the second collector section having first and second ends; a surge tank; first and second conduits leading from the surge tank to the first and second collector sections respectively, the first and second conduits fluidly communicating with the first and second collector sections at the respective first ends thereof; conneciton passage leading from a location essentially mid-way between the ends of the first collector section to a location essentially mid-way between the ends of the second collector section; and a valve disposed in the connection passage, the valve being arranged to assume a closed position wherein communication between the first and second collector sections is prevented and an open position wherein communication is permitted, the valve being arranged to change from the closed position to the open position upon the magnitude of a selected operational parameter of the engine exceeding a predetermined level.
With the above defined invention it is possible to arrange an induction manifold for a V-6 engine in a manner that the collector sections are located side by side and essentially parallel with an elongate surge tank. The difference in the lengths of the conduits which interconnect the surge tank with the respective collectors with such an arrangement is compensated for by varying the volumes of the two collectors in a manner which achieves a suitable balance in resonance characteristics. By arranging the connection tube to have an essentially U-shape and to lie on tp of the side-by-side collectors, a highly compact arrangement results.
BRIEF DESCRIPTION OF THE DRAWINGS
The features and advantages of the arrangement present invention will become more clearly appreciated from the following description taken in conjunction with the accompanying drawings in which:
FIG. 1 shows in schematic form the prior art arrangement discussed in the opening paragraphs of the present disclosure;
FIG. 2 shows in schematic form the induction system arrangement which characterizes the present invention;
FIG. 3 is a sectional elevation of an embodiment of the present invention;
FIG. 4 is a sectional plan view of the induction manifold used in the arrangment shown in FIG. 3;
FIG. 5 is a sectional view taken along section line V--V of FIG. 4;
FIG. 6 is an enlarged sectional view of the valve shown in FIG. 5;
FIG. 7 is a graph showing in terms of engine torque and engine rotational speed, a comparison of the torque characteristics derived using the prior art arrangement shown in FIG. 1 and the present invention;
FIG. 8 is a graph showing in terms of engine torque and engine speed, the change in torque developed by an engine equipped with the arrangement of the present invention when the length of the connection pipe which bridges the two inducton collectors is varied;
FIG. 9 is a graph also in terms of engine torque and speed showing the effect of change in diameter (viz., cross-sectional area) of the connection pipe on the engine torque characteristics;
FIG. 10 is a graph showing the effect of change of volume of the collector sections on the torque generation characteristics of the engine;
FIG. 11 is a similar graph showing the effect of induction conduit diameter (cross-sectional area) on the engine output; and
FIG. 12 is a graph showing the the effect of changing the volume of the collectors on the engine output with the cross-sectional area of the induction conduits set at a relatively small value.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Before proceeding to describe an actual embodiment of the present invention it is deemed advantageous to firstly turn to FIG. 2 wherein the basic arrangement of the present invention is set forth in schematic form.
As will be appreciated the arrangement of the present invention is such that the induction manifold 100 includes induction conduits 102, 104 which lead from the surge tank 106 and communicate with the ends of collectors 108 110, and a connection pipe 112 leads from a location essentially mid-way between the ends of collector 108 to a location essentially mid-way between the ends of collector 110. The branch runners 114a-114f which communicate the two collector sections 108, 110 with the combustion chambers of cylinders #1 to #6 via induction ports 115 are arranged to branch-off from the collectors at essentially equally spaced intervals. A valve 116 is disposed in the connection pipe 112.
Experiments have shown that it is preferable to arrange for the volume the collectors 108, 110 to be in excess of half of the engine displacement. Viz., as shown in FIG. 10 given that the displacement of the engine is 3 liters (2960 cc), the length of the induction conduits 102, 104 which interconnect the surge tank 106 and the collectors, is 430 mm and the diameter of the same 70 mm, when the volume of the collectors 108, 110 are arranged to be 0.9 liter the output of the engine is markedly lower than if the capacity thereof is slightly greater than half of the engine displacement (viz., 1, 700 cc).
Experiments wherein the diameter of the induction conduits 102, 104 was varied while holding the volume of the collectors 108, 110 and the length of the induction conduits 102, 104 constant at 1.7 liter and 430 mm respectively; revealed that a diameter of 70 mm gave superior engine performance over an arrangement wherein the diameter was reduced to 40 mm.
To confirm the above results experiments wherein the volume of the collectors 108, 110 were varied with an induction arrangment wherein the length and diameter of the induction conduits were held constant at 430 mm and 40 mm respectively. As shown, when the volume of the collectors was 1.7 liter the torque developed by the engine was notably better than when the volume was reduced to 0.6 liter.
As will become clear herinlater with a discussion of the graphs of FIGS. 7 to 9, by using the above described arrangement and by selecting the length and diameter of the connecting pipe 112 in conjunction with the dimensions of the remaining system, it is possible to achieve an engine performance which is notably better than that achieved with the FIG. 1 arrangement.
The diameter of the engine induction ports 115 in the engine tested was 42 mm. Accordingly, from the above data it was determined tha the cross-sectional area of the induction conduits should be greater than 2.5 times the cross sectional area of the induction ports 115.
Subsequent experiments (which will be dealt with in more detail hereinlater) revealed that given the above mentioned manifold specifications, it is preferable for the connection pipe 112 to be 100 mm to 430 mm in length (viz., 0.33 to 1.5 times the length of collectors 108, 110 and therefor about the sum of the diameters of three cylinders; and to be 40-60 mm in diameter.
FIG. 8 shows the results of experiments which were conducted in order to the detect the effect of changing the length of the connection pipe 112 on the torque produced by the engine. it will be noted that the diameter of the pipe was held constant at 40 mm.
As shown, all of the pipes tested showed better torque generation characteristics over an arrangement wherein the two collectors were communicated directly (viz., via a pipe having a zero length).
FIG. 9 shows the results of tests conducted to determined the optimum diameter (viz., the cross-sectional area) of connection pipe 112. During these tests the length of the pipe was held constant at 300 mm. As will be appreciated the engine performance did not vary to any particular degree when pipes having 40, 50 and 60 mm diameters were used. However, in order to avoid any marked changes in internal volume of the induction system it is deemed appropriate that the diameter of the pipe be arranged to close to or within the above mentioned range.
With the above described specifications when the engine is operating a low engine speeds, the resonance characteristics of the induction system with the vale 116 closed, match the pressure pulsations which occur in the induction system and induce the engine to produce torque which varies as shown by chain line in FIG. 7. Upon opening of valve 116 the collecltors 108 and 110 become communicated via connection pipe 112 whereby the distance of the intake system ahead of the intake ports 115 is increased by only the distance between the runners 114a and 114b so that the system becomes resonant with short wavelength pulsations which are produced under such conditions. The torque generation characteristics with the valve 116 open are depicted in FIG. 7 by the solid line trace. As will be appreciated the torque produced by the engine with the present invention is higher than that produced by the prior art arrangement shwn in FIG. 1 of the drawings, the torque generation characteristics of which are denoted by the chain line trace in the same figure. The difference between the invention and the prior art which occurs with the valve open and the engine operating at high engine speed is highlighted by hatching in FIG. 7.
As will be appreciated it is advantageous to select the point at which the valve is switched from its closed position to its open one so that a sharp change in torque generation is not experienced. Viz., it is advantageous to select the changeover point to be conincident with the engine speed at which the chain line trace intersects the solid line one.
FIGS. 3 to 6 show an actual embodiment of the present invention as applied to a 2960 cc displacement V-6 type engine.
In this arrangement the induction manifold 100 is arranged above and between two banks of three c2ylinders of a V-6 engine 300. As shown, the branch runners 114a-114f in this embodiment lead upwardly from the intake ports 302 the engine and open into the bottom their respective collector sections 108, 110. As best seen in FIG. 4 the collector sections are defined in a housing 120 which is partitioned by wall 122 which extends essentially parallel with the longitudinal axis of the engine. The induction conduits 102, 104 blend into the ends of the collectors 108, 110 and lead to the surge tank 106.
In this arrangement, the surge tank 106 is, as best seen in FIG. 4, elongate and arranged to extend parallel to the collector housing 120. The surge tank 106 is arranged to communicate with the an air cleaner 124 via a conduit arrangement including a throttle valve 126 and an air flow meter 128 (in this embodiment the air flow meter is depicted as being, merely by way of example, a hot wire/vortex type).
The connection pipe 112 in this embodiment is advantageously arranged to have an essentially U-shape (see FIG. 4) and to lie flat on the top or "roof" of the collector housing 120. The valve 116 which has a construction as best seen in FIG. 6 is arranged to located in the U-shaped connection pipe 116 at a location adjacent the end of collector section 108. With this arrangement an actuator 130 of the valve 116 may be arranged to depend into the space available at this point (see FIG. 5).
FIG. 6 shows the construction of the valve 116 and actuator 130 in detail. In this embodiment the valve 116 includes a vane 132 which is secured to one end of a rotable shaft 134. Roller bearings 136, 138 rotatably journal the shaft 143. The actuator which may be any suitable type (viz., for example electrical, electrical/mechanical, pneumatic or the like) is disposed in a cup-shaped housing 140 and between the roller bearings 136, 138.
As will be best appreciated from FIG. 5, by arranging the cross-section of the collector sections 108, 110 and induction conduits 102, 104 to be essentially rectangular in shape, the height of the induction manifold can be kept to a minimum and the arrangement rendered highly compact. Arranging the longitudinal vertical cross-section of the U-shaped connection pipe to be slightly wedge shaped tends to minimize the height increasing effect of placing the same on top of the housing 120.
In the instant embodiment the displacement of the engine is 2960 cc, the volumes of the collectors 108 and 110 are 1.9 and 1.6 liters respectively (the sum being greater than the engine displacement), and the volume of the surge tank 106 is arranged to be 3 liters and thus act as the free ends of the system through which the pressure waves pass.
It will be noted that with the instant embodiment as the arrangement of the induction passages and the collectors is not symmetrical it is necessary to vary the volumes of the collectors slightly so as to achieve a unification in the supercharging effect on the two group of cylinders. The performance characteristics of the this embodiment are essentially as shown in FIG. 7.
With the above described embodiment as the valve 112 is located at a high position the possibility that any water which might have entered the system will not collect therein and induce the possibility that under very cold conditions that the valve will freeze in a closed state.
It will also be noted that although the connection pipe is illustrated as being cast integrally with the remaining portions of the housing 120 it is possible to provide same as a separate detachable unit.
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In order to minimize the supercharging effect from the cylinder to cylinder and to maximize the efficiency of the inertia supercharging effect over essentially the whole engine speed range, first and second elongate collectors which communicate with separate banks of cylinders are interconnected at essentially their mid points by a connection tube having a selected length and cross-sectional area. An engine speed responsive valve disposed in the tube or pipe selectively induces the situation wherein quasi separate induction systems are defined for each bank of cylinders or a single enlarged system is established.
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FIELD OF THE INVENTION
The present invention relates to a new type of lens, in particular, but not exclusively, for use with an LED luminaire having an LED integrated light source.
BACKGROUND TO THE INVENTION
An LED integrated light source lens contributes to boosting the surface luminous efficiency of an LED integrated light source. An LED integrated light source lens of the known kind, comprising a light entering section in the shape of hole and of a light emitting section in the shape of a cup, has smooth surfaces on both the light entering and emitting sections. This has as a disadvantage that light utilisation efficiency of the LED integrated light source is very poor. A further disadvantage is that this arrangement creates luminous spots with obvious colour aberration, that is the colour rendering index is adversely affected.
SUMMARY OF THE INVENTION
According to the present invention an LED integrated light source lens comprising a light entering section in the shape of a hole, a light emitting section in the shape of a cup, is disclosed incorporating an optical lens positioned between the light entering section and the light emitting section, wherein the external surfaces of the light entering and emitting sections include portions having densely distributed convex facets.
Preferably, the optical lens has a spotted surface on one side.
Preferably, the optical lens has a curved surface on the other side.
Preferably, the curved surface is convex.
Preferably, the hole is provided with a non-spherical surface at its base
This construction has a number of advantages. The densely distributed convex facets on the external surfaces of the light entering and emitting sections, cause the LED integrated light source to emit multi-point lights, which enhances light utilisation efficiency, creates no spot lights with colour aberration, this in turn greatly improves the colour rendering index. The side of the optical lens having a spotted surface, creates multi-point lights. The other side of the optical lens, having a curved surface, changes the light beam angle.
A further advantage is that such a lens is relatively squat allowing for the use of LED light sources together with such a lens in new applications.
According to a second aspect of the present invention a lens is provided with a plurality of light entering sections, each in the shape of a hole, a light emitting section associated with each of the light entering sections, the light emitting section being in the shape of a cup, is disclosed incorporating an optical lens positioned between each light entering section and the associated light emitting section, wherein the external surfaces of the associated light entering and emitting sections include portions having densely distributed convex facets.
According to a third aspect of the present invention, a downlight comprises a casing, a light source, a lens according to the first or second aspects of the present invention, a lens holder and a heat sink.
Preferably, the downlight further comprises a glass and retaining means for the glass.
Preferably, the light source comprises one or more LEDs mounted on a circuit board. Preferably, the circuit board may be formed of a ceramic material. Alternatively, the circuit board may be formed of aluminium and a brass or copper disc located between the circuit board and the heat sink.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described, by way of example only, in relation to the attached Figures, in which
FIG. 1 shows a schematic perspective view of a first embodiment of a lens according to the present invention;
FIG. 2 shows a view from below of the lens of FIG. 1 ;
FIG. 3 shows a section along line A-A of FIG. 2 ;
FIG. 4 shows a section similar to that of FIG. 3 showing schematically the flow of light through the lens;
FIG. 5 shows a side view of a second embodiment of a lens according to the present invention;
FIG. 6 shows a section along line A-A of FIG. 5 ;
FIG. 7 shows a view from below of FIG. 5 ;
FIG. 8 shows a perspective view of the front of FIG. 5 ;
FIG. 9 shows a side view of a third embodiment of a lens according to the present invention;
FIG. 10 shows a view from below of FIG. 9 ;
FIG. 11 shows a side view of a forth embodiment of a lens according to the present invention;
FIG. 12 shows a view from below of FIG. 11 ;
FIG. 13 shows a side view of a fifth embodiment of a lens according to the present invention;
FIG. 14 shows a view from below of FIG. 13 ;
FIG. 15 shows a side view of a sixth embodiment of a lens according to the present invention;
FIG. 16 shows a view from below of FIG. 15 ;
FIG. 17 shows a side view of a seventh embodiment of a lens according to the present invention;
FIG. 18 shows a view from below of FIG. 17 ;
FIG. 19 is a sectional view of a first embodiment of a down light in accordance with a second aspect of the present invention; and
FIG. 20 is a sectional view of a second embodiment of a down light in accordance with a second aspect of the present invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring first to FIGS. 1 to 3 , the lens can be seen to comprise a substantially solid body 10 having a generally conical or frusto-conical portion 4 provided with a flange 12 extending thereabout providing a circular periphery to the lens. The conical or frusto-conical portion 4 extends from the circular flange 12 . The side of the flange 12 from which the conical or frusto-conical portion 4 extends will be referred to as the bottom or rear side and reference to an ‘upper side’, a ‘front side’, ‘above’ or ‘below’ should be interpreted accordingly.
The lens has a central vertical axis. The lens is formed from a transparent material. In the case of a transparent plastics material, the lens is preferably formed by injection moulding.
An upper portion of the conical or frusto-conical portion 4 is provided with a recess or hole provided therein. The hole is in the form of a blind recess. As may be seen form the figures the recess is hexagonal in section, though other sections may be used. The side or sides of the recess are aligned with the central vertical axis.
The tip of the conical or frusto-conical portion 4 is provided with two cut away portions 14 extending along a portion of a circumference of the conical or frusto-conical portion 4 to create two tabs 16 extending inbetween. From FIG. 2 , it can be seen that the lens is symmetric about a central plane.
In use, an LED is located at the opening of the hole in the conical or frusto-conical portion 4 , such that the hole forms a light entering section 1 of the lens. A base of the hole is provided with a refractive surface 18 for example a spotted surface. In this embodiment the refractive surface 18 is circular in shape. From FIG. 2 it can be seen that this has taken the form of a hexagonal pattern of convex facets formed on the surface of the base of the hole. In use, the refractive surface 18 creates multi-point light beams. Preferably, the refractive surface 18 is a non-spherical refractive surface. In this embodiment the refractive surface 18 is located on a generally level plane.
The external surface of the conical or frusto-conical portion 4 is provided with a network of densely distributed convex facets 24 . In use, these facets 24 create multi-point light beams. The facets 24 of this embodiment can be seen to be generally triangular.
An external surface of the light entering section 1 can thus be seen to be provided with convex facets 24 on the conical or frusto-conical portion 4 and convex facets on the refractive surface 18 .
The front of the lens is provided with a shaped recess. The shaped recess is in the shape of a cup, being generally concave, comprising an inclined surface 20 extending inwardly from the front face of the lens, the inclined surface 20 meeting a generally circular base 22 of the cup shape, the base 22 being convex in shape. The curved convex shape is used to change the light beam angle. The generally circular base 22 is provided with a network of refractive surfaces in the form of densely distributed convex facets. The inclined surface is preferably concave.
In use, the shaped recess forms a light emitting section 2 of the lens.
The portion of the lens between the hole and the shaped recess forms an optical body or lens 3 positioned therebetween.
It will be understood that the light entering section 1 , the light emitting section 2 and the optical lens 3 are formed as a unitary or one piece body from the transparent material.
FIGS. 5 to 8 show a second embodiment of a lens in accordance with the present invention. It is noted that this embodiment (and those following) do not feature the cut out at the end of the conical or frusto-conical portion. Also, the hole or blind recess is circular in section.
This embodiment (and those following) is further distinguished by the pattern of the network of refractive surfaces.
Similar reference numerals are used to refer to similar aspects of the invention. Thus, a conical or frusto-conical portion of a lens is provided with a flange 112 . A light entering section 101 includes an outer surface of the conical or frusto-conical portion provided with a network of refractive surfaces 124 and a non-spherical base surface 118 provided at rear surface of the lens. The network of refractive surfaces 124 generally diamond shaped. A generally concave light emitting section 102 comprises an inclined surface 120 extending inwardly from the front face of the lens, the inclined surface 120 meeting a generally circular base, the base being provided with a network of refractive surfaces 128 . In this embodiment (and those following) the base is generally planer. An optic lens 103 is defined between the light entering section 101 and the light emitting section 102 .
The functioning of the lens is now described with reference to FIG. 4 . Light is emitted from a light source, such as an LED (not shown) and may adopt a number of paths. Light passing through the sides of the light entering section 101 will having passed through the lens encounter the network of convex facets 124 . This causes the light at the surface to form multipoint full reflection lights directed back toward the light emitting surface section 102 . The creation of multipoint full reflection lights decreases the glare index and increases the colour rendering index.
Light encountering the refractive surface 118 on the base of the hole is focussed on the network of refractive surfaces 128 on the light emitting section 102 of the lens. This improves light efficiency.
Light passing to the network of refractive surfaces 128 on the light emitting section 102 of the lens forms multi point refraction emitting light which decreases the glare index and increases the colour rendering index.
The inclined surface 120 surrounding the network of refractive surfaces on the light emitting section 102 of the lens facilitates the injection moulding process and improves product consistency.
FIGS. 9 and 10 show a third embodiment of a lens in accordance with the present invention. The third embodiment is of similar section to the second embodiment and shows a further pattern of refractive surfaces 224 , the facets comprising a mix of diamond shaped facets and pentagonal facets.
FIGS. 11 and 12 show a fourth embodiment of a lens in accordance with the present invention. The fourth embodiment is of similar section to the second embodiment and shows a further pattern of refractive surfaces 324 , the facets comprising a mix of hexagonal facets and pentagonal facets.
FIGS. 13 and 14 show a fifth embodiment of a lens in accordance with the present invention. The fifth embodiment is of similar section to the second embodiment and shows a further pattern of refractive surfaces 424 , the facets comprising a mix of diamond shaped facets and octagonal facets.
FIGS. 15 and 16 show a sixth embodiment of a lens in accordance with the present invention. The sixth embodiment is of similar section to the second embodiment and shows a further pattern of refractive surfaces 524 , the facets comprising generally rectangular facets.
FIGS. 17 and 18 show an seventh embodiment of a lens in accordance with the present invention. The seventh embodiment is of similar section to the second embodiment and shows a further pattern of refractive surfaces 624 , the facets comprising a patterning of polygonal facets.
In each of the embodiments the refractive surfaces comprise convex facets. In a further embodiment shown in use in FIG. 19 , a lens is provided having a plurality of light entering sections, each having an associated light emitting section and an optical lens positioned between each light entering section and the associated light emitting section.
Referring now to FIG. 19 , there is shown a lighting unit is the form of a downlight unit 702 incorporating a terminal block, transformer unit or driver 704 provided on a mounting arm secured at one end to an upper end of the downlight unit 702 .
The downlight unit comprises a light source 706 in the form of a plurality of LEDs mounted to a circuit board 708 , for example an aluminium printed circuit board, the circuit board including control circuitry for the light source 706 , a heat sink 710 connected to a cylindrical casing, the heat sink 710 being provided to a rear side of the circuit board 708 and a lens arrangement located at a front side of the circuit board 708 .
A brass or copper disc 740 is provided between the circuit board 708 and the heat sink 710 .
The term “cylindrical casing” means conforming approximately to the shape of a hollow cylinder. It will be understood that a misshapen cylinder will work equally well. Similarly, while the embodiments show a generally circular cylindrical tubular body other sections may be used with amendment to the sectional shape of other components.
The heat sink 710 is formed from any suitable material, preferably cast aluminium. The heat sink 710 comprises at a lower end an outer annular portion for location against an upper portion of the cylindrical casing. The annular portion surrounds an end face. In the illustrated embodiment the end face is proud of the annular portion.
The cylindrical casing comprises a mounting ring 714 . The mounting ring 714 comprises a side wall having a lower peripheral annular flange extending outwardly from a bottom end of the side wall and an upper peripheral annular flange extending inwardly from an upper end of the side wall. The mounting ring 714 is formed from any suitable material, preferably steel.
The upper peripheral flange locates against the annular portion of the heat sink 710 and surrounds the end face of the heat sink.
A first ring or washer 716 of silicon is provided on the upper surface of the lower peripheral flange. In use, the ring or washer 716 butts up against a rim of an aperture into which the downlight is fitted.
A bracket 718 incorporating spring biased members or clips 720 is located about the heat sink 710 . The spring biased members or clips 720 are adapted to secure the lighting unit in a recess in a known manner. It can be seen that the driver 704 is secured a central upper region of the bracket 718 . The bracket 718 is secured to the upper peripheral flange of the mounting ring 714 in a suitable fashion, for example by screw fasteners 722 .
The lens arrangement comprises a lens holder 724 and a lens 726 in accordance with the second aspect of the present invention. The lens holder 726 may be of any suitable material, for example a polycarbonate. The lens 724 may be of any suitable material, for example polymethylmethacrylate.
The lens 726 is retained in position relative to the light source 706 by the lens holder 724 . The lens holder 724 comprises a ring or washer having a support structure for engaging and securing the lens 726 to the lens holder 724 , as well as an inwardly directed finger or fingers. The lens 726 is provided with cooperating features to engaging the lens holder 724 and becoming secured to it. The lens holder 724 is secured at its periphery to the upper peripheral flange of the mounting ring 714 in a suitable fashion, for example by utilising the screw fasteners 722 securing the bracket 718 to the mounting ring 714 .
A bezel 730 is fitted to an underside of the mounting ring 14 . The bezel 730 may be of any suitable material, for example cast aluminium. The bezel 730 comprises an inner wall having an inwardly directed shoulder toward a lower end and a radially outwardly directed annular flange at the lower end. The inner wall extends within the side wall of the mounting ring 714 . In use the inner wall of the bezel and the side wall of the mounting ring are provided with cooperating features, such as male and female parts of a bayonet fixing, to enable the bezel 730 to be secured to the mounting ring 714 . In use the inner shoulder supports a glass 732 located in front of the lens 726 . The glass 732 is of any suitable material to allow transmission of the light emitted from the lens 726 .
Preferably a second ring or washer 734 of silicon extends between the radially outwardly directed annular flange of the bezel 30 and the first peripheral flange of the mounting ring 14 .
The circuit board 708 is generally circular and provided with openings by which the circuit board may be located in position. In practice the brass or copper disc 740 is secured about its periphery to the mounting ring 714 . The end face of the heat sink 10 is in thermal contact with a rear face of the brass or copper disc 740 . The circuit board 708 is secured through the brass or copper disc 740 to the heat sink 710 by any suitable means such as fasteners.
A ring or washer 736 of a suitable fireproof material is preferably located between the edge of brass or copper disc 740 and the upper peripheral flange of the mounting ring 714 .
A second embodiment of a downlight unit 802 in accordance with the present invention is shown in FIG. 20 . Similar parts will be referred to by similar reference numerals. The downlight unit 802 comprises a light source 806 mounted to a circuit board 808 , the circuit board including control circuitry for the light source 806 , a heat sink 810 provided to a rear side of the circuit board 808 and a lens arrangement located at a front side of the circuit board. The mounting ring 814 is of like configuration to that of the previous embodiment.
A bracket 818 having depending legs and a central portion is provided in which spring biased members or clips 820 are mounted on each of the legs. Feet at the free ends of the legs are secured to the mounting ring 814 .
A driver 804 is mounted within a driver box in turn located within a recess in the heat sink 810 . The driver box is provided with flanges by which the driver box may be secured to an upper part of the heat sink 810 by any suitable means.
The heat sink 810 is mounted on the mounting ring 814 with a front face of the heat sink 810 being located within an upper annular flange of the mounting ring 814 .
A first ring or washer 816 of silicon is provided on a lower peripheral flange of the mounting ring 814 .
The circuit board 808 is secured to the mounting ring 814 by fasteners 822 , such that the end face of the heat sink 810 is in thermal contact with a rear surface of the circuit board 808 . The fasteners 822 also serve to secure a lens holder in position. The lens holder is used to locate a lens 826 in position.
In this embodiment, the lens holder comprises two parts. A first part 824 a of the lens holder is secured in place to the upper peripheral flange of the mounting ring 814 . A second part 824 b of the lens holder retains a periphery of the lens 826 between itself and the first part 824 a of the lens holder.
A glass 832 retained by a bezel 830 , itself located within and by the mounting ring 814 , is disposed in front of the lens 826 and lens holder. A second ring or washer 834 of silicon extends between the bezel 830 and the mounting ring 814 . A ring or washer 836 of fireproof material is preferably located between the circuit board 808 and the mounting ring 824 .
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LED-integrated lens comprising a light-entering section ( 1 ) in the shape of a hole, a light-emitting section ( 2 ) in the shape of a cup, incorporating an optical lens ( 3 ) positioned between said light-entering and light-emitting sections ( 1, 2 ) wherein the external surfaces of the light-entering ( 1 ) and of the light-emitting ( 2 ) sections include portions having densely-distributed convex facets. This lens enhances light utilization efficiency, avoids creating spots with color aberration hence greatly improves color rendering.
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CROSS REFERENCE TO RELATED APPLICATION
This is a continuation of copending international application PCT/DE98/00290, filed Feb. 2, 1998, which designated the United States.
BACKGROUND OF THE INVENTION
Field of the Invention
The invention lies in the field of semiconductor technology. Specifically, the invention deals with minimizing the access time in semiconductor memory devices.
Semiconductor memories such as, for instance, dynamic semiconductor memories (DRAMs) are fabricated from semiconductor wafers. One wafer contains a multiplicity of identical memory chips. The dictates of production mean that the electrical parameters of these individual chips vary.
An important criterion for the power assessment and the selection of dynamic semiconductor memories among the electrical parameters is the access time. The access time is the time which elapses during a reading operation after the application of the address until the data read out are valid at the output. It is determined by the design and by a multiplicity of technological parameters (poly2 etching dimension, gateoxide, spacer TEOS, . . . )
On account of tolerances of the technological parameters and the dictates of production, the access times vary both among memory chips of an individual wafer and for memory chips of different wafers of a fabrication series. In a random selection of memory chips, the access times have a normal distribution. The proportion of memory chips whose access time lies above a specific limit can only be sold at a lower price than the faster memory chips, that is to say the memory chips which have a shorter access time.
If the technological parameters are chosen such that the proportion of fast chips increases, then the proportion of defective memory chips also increases, for example as a consequence of the punch-through effect in transistors or other production-dictated faults.
In this context, European patent application EP 0 602 355 A1 discloses a voltage generator for memories and circuits which is programmable by means of fuses. An internal voltage is increased to a desired voltage in steps using a counter and permanently set by blowing the fuses.
The relationship between the supply voltage and the access time of a semiconductor memory is disclosed in Atsumi et al., “Fast Programmable 256K Read Only Memory with On-Chip Test Circuits,” in: IEEE Transactions on Electron Devices (ED 32,2/1985, No. 2, New York, USA)
SUMMARY OF THE INVENTION
It is accordingly an object of the invention to minimize the access time of semiconductor memories, which overcomes the above-mentioned disadvantages of the heretofore-known devices and methods of this general type and to specifically minimize the access time for those semiconductor devices which, on account of technological parameter fluctuations, have a longer access time than the access time which can be achieved for the technological parameters chosen.
With the foregoing and other objects in view there is provided, in accordance with the invention, a method of minimizing access time to data of a semiconductor memory by means of a supply voltage generator for generating an internal supply voltage, which comprises the following method steps:
defining a standby current of a semiconductor memory as a parameter characterizing an access time to the semiconductor memory;
assigning a value of a boost voltage to the value of the parameter, whereby a magnitude of the boost voltage is greater than the given value of an internal supply voltage of the semiconductor memory and at which boost voltage the semiconductor memory is still functional; and
setting the internal supply voltage to the value of the boost voltage.
With the above and other objects in view there is also provided, in accordance with the invention, a related method which comprises the following method steps:
defining a threshold voltage of a field-effect transistor on a semiconductor memory as a parameter characterizing an access time to the semiconductor memory;
assigning a value of a boost voltage to the value of the parameter, whereby a magnitude of the boost voltage is greater than the given value of an internal supply voltage of the semiconductor memory and at which boost voltage the semiconductor memory is still functional; and
setting the internal supply voltage to the value of the boost voltage.
The invention has the advantage that the yield of comparatively fast memory chips is increased, when all the memory chips on a wafer are measured in their entirety and all the memory chips of a fabrication series are measured in their entirety in comparison with memories in which the method according to the invention is not used. The application of the method does not impair the yield of functional memory chips. A further advantage of the method according to the invention is that production fluctuations which affect the access time can be compensated for after production. Moreover, the technological parameters, in particular the poly2 line width, can be dimensioned such that they lie within a reliable range in which technology-related failures are avoided.
In accordance with an added feature of the invention, the value of the access time characterizing parameter is determined after applying an external supply voltage to the semiconductor memory, as soon as the semiconductor memory has reached a state of functional readiness.
In accordance with an additional feature of the invention, the value of the access time characterizing parameter is determined during a functional test of the semiconductor memory.
In accordance with another feature of the invention, the assigning step comprises assigning the value of the boost voltage to the value of the parameter by means of experimentally determined measurement curves.
In accordance with a further feature of the invention, the setting step comprises setting the internal supply voltage to the value of the boost voltage by blowing at least one fuse of the supply voltage generator of the semiconductor memory.
In a preferred embodiment, the blowing of fuse is effected temporally in parallel with a blowing of any other fuses of the semiconductor memory.
In accordance with again an added feature of the invention, the setting step comprises controlling the supply voltage generator by means of a control circuit, whereby the threshold voltage of the field-effect transistor is transferred to the control circuit.
In accordance with a concomitant feature of the invention, the setting step comprises setting the internal supply voltage to the value of the boost voltage in steps. The preferred step of the increase is thereby 0.3 V.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a method for minimizing the access time in semiconductor memories, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING
The FIGURE is a flow diagram illustrating an exemplary sequence of the method according to the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Given a predetermined design and technological parameters, the access time critically depends on the internal supply voltage at which the cell array of the semiconductor memory operates. This voltage may differ from an external supply voltage with which the external circuit situated outside the cell arrays is operated.
The present invention is based on the fact that a supply voltage generator on the memory chip provides the internal supply voltage. However, the method according to the invention can also readily be used if the internal supply voltage is accommodated by a supply voltage generator on a separate chip or is fed to the semiconductor memory externally in another way.
The internal supply voltage directly influences the access time. By increasing the internal supply voltage, the current yield and transconductance of the transistors of the memory cell array are increased. That leads to a faster switching behavior of the transistors and, consequently, to a shorter access time. The internal supply voltage is usually constant (for example 3.3 V). The method according to the invention provides for the internal supply voltage to be increased in the memory chips whose access time exceeds a predetermined threshold. The access time is reduced as a result of this.
In a first step 101 of the method, the value of a parameter which is an unambiguous measure of the access time of the semiconductor chip is determined. From the value of this parameter which characterizes the access time, the access time can be determined for example mathematically or with the aid of an existing measurement curve. The parameter may be, for example, the standby current, that is to say the supply current which flows in the case where the semiconductor memory is inactivated, if no access is made to the semiconductor memory. By way of example, the standby current can be measured in the course of a first test procedure that is implemented (pre die sort, pre-dicing test), when the individual semiconductor chips are still situated on the wafer.
It is preferable for the standby current to be determined during an initialization phase at a point in time after the application of the external supply voltage to the semiconductor memory at which the semiconductor memory has just reached its state of functional readiness.
The resulting difference between a desired value of the access time, the desired value being identical to the predetermined threshold of the access time or lying above the threshold, and the determined access time determines the absolute value of the voltage to which the internal supply voltage is subsequently raised. At this boost voltage, the access time is shorter than before. It is stipulated in each case depending on the value of the measured parameter which characterizes the access time, in such a way that it has the highest possible magnitude that the functionality of the semiconductor memory is preserved.
It is entirely within the invention to directly infer the possible boost voltage from the value of the measured characteristic parameter. For this purpose, use is made for example of measurement curves which are determined in test runs and reproduce the relationship between the determined value of the parameter which characterizes the access time and the maximum permissible internal supply voltage (=boost voltage).
It is well known to those of skill in the art of semiconductor memories that redundant memory cells provided for the replacement of defective memory cells are selected by blowing so-called redundancy fuses (cutting redundancy fuses). The setting of the voltage in supply voltage generators is frequently done in a similar manner using generator fuses. In a special embodiment of the method according to the invention, suitable generator fuses are blown depending on the boost voltage determined. This can be done temporally in parallel with the blowing of any redundancy fuses that are present.
In other words, in this embodiment, the internal supply voltage is increased in steps by the blowing of individual generator fuses. It is advantageous to provide for increasing in steps of 0.3 V. In this case, it is favorable if a total voltage change of more than 1 V can be achieved. However, other voltage steps and other voltage changes are also possible.
The blowing of the generator fuses is usually done by means of laser light or by using current pulses.
As an alternative, the threshold voltage of a field-effect transistor can also be provided as the parameter which characterizes the access time. If the transistor is likewise situated on the semiconductor memory, then it is subjected to the same fabrication fluctuations as the actual semiconductor memory. In other words, there is a direct relationship between the threshold voltage of the field-effect transistor and the access time of the semiconductor memory, which is used to set the internal supply voltage to the value of the boost voltage. For this purpose, the threshold voltage is transferred for example to a control circuit which directly controls the supply voltage generator.
The flow diagram in the FIGURE shows one embodiment of the method according to the invention in the course of a production sequence. The access time of the memory chips is determined, for example during a first functional test of the memory chips. Comparing the determined access time with the predetermined desired value in step 102 reveals the memory chips which are too slow and for which the internal supply voltage is consequently increased. Their boost voltage is determined proceeding from the determined access time in step 103 . The spatial position on the wafer plane of each memory chip is determined by its coordinates. For each memory chip, the fact of whether a boost voltage, and if appropriate which boost voltage, results from the measured access time is recorded on a data carrier together with the position of the chip in step 104 . These details are required for the blowing of the generator fuses and serve for coding the generator fuses. Afterwards, the redundancy fuses which are to be blown are additionally recorded on the data carrier for each semiconductor chip in step 105 . This coding of the redundancy fuses may also be effected prior to the coding of the generator fuses.
The redundancy and generator fuses, which are correspondingly identified in the coding of the redundancy fuses and the coding of the generator fuses, are then blown in step 106 .
It is advantageously done together in a single step. Step is then followed by the customary test methods for conductor chips.
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The dictates of production mean that the access times of semiconductor memories are subject to fluctuations, even given identical technological parameters. The fluctuations lead to a proportion of slow memory chips. The access time is shortened by raising the internal supply voltage of the slower semiconductor memories by an absolute value which is dependent on the respective semiconductor memory. The method is employed in semiconductor memories, in particular in dynamic semiconductor memories.
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BACKGROUND OF THE INVENTION
In a circular knitting machine for the production of socks or knitted articles with argyle intarsia pattern obtained by a reciprocating motion - like the machine described in Italian Pat. No. 997,212 --it is necessary to select - before every yarn-feeding station and in both directions of motion - those needles which are going to knit with the yarn fed at that particular station. This selection is mechanically achieved by means of peg drums which act upon the butts of the selection jacks according to certain programmable sequences; this action is performed by dual fork-like selection levers superimposed to form a pack.
As it is known, the patterns obtainable by this method have, in the width direction, a maximum number of needles equal to the number of butts of the selection jacks which can be arranged diagonally (or, in the case of a symmetrical pattern, which can be arranged according to a double "V"-shaped diagonal) and have, in the length direction, a maximum number of courses equal to the number of rows of pegs available on the circumference of each pattern drum.
These limits in the possible patterns achievable could be overcome by adopting electronic programmers.
Nevertheless, direct control on this type of selection fork levers by means of electromagnetic actuators cannot be easily carried out either because of the necessary, considerable forces and high response speeds (which cannot be attained owing to the limited space available) or because the diagonal of the selecting butts should be wider than the levers themselves, in order to allow their up and down movement in the empty space between one diagonal and the other. It would be necessary, therefore, to increase the number of butts, make the cylinder higher and adopt other expedients with all the ensuring drawbacks.
It is possible to divide each pack of double levers into two packs of single levers, but this requires a number of packs of levers (and thus of electromagnetic actuators) twice as much as the number of feeds, with consequent big problems as for the space available around the cylinder and higher cost.
SUMMARY OF THE INVENTION
It is an object of this invention to provide a machine and a method to select the needles during both motion directions, substantially by providing packs, that is, rows of single selection levers, the latter being sufficiently light and thin to act between one butt and the other of the same row, that is, of the same level and belonging to adjacent groups of selection jacks in which, for example, the butts are diagonally arranged, said selection levers being symmetrically disposed in respect to particular cam profiles of a selection ring so as to require only a number of actuator packs equal to that of the feeds, said packs being possibly controlled by mechanical, electronic or whatever other type of means.
In other words, a machine according to the invention --for the formation of articles having argyle intarsia pattern, with a driving of the needles cylinder at reciprocating motion, having needles, intermediate jacks and selection jacks provided with selection butts, and packs of selection cams or levers, said cams or levers being able to select the needles to be raised - where the same group, that is, a pack of selection levers is located between two adjacent feeds and selects the needles for one or the other feed in one or the other direction of the machine reciprocating motion.
In practice, the selection levers usually operate with a thrust on selection jacks associated with elastic pusher jacks, with which a selection ring with rising profiles cooperates, while the oppposite profiles of a lowering-cam ring cooperate with the intermediate jack butts. In this case it is possible to provide: that said rising profiles are symmetrical with respect to the feeding stations and to the packs of selection levers and that the profiles of the control ring for lowering the intermediate jacks are symmetrical in a similar way; that said rising profiles have, in correspondence with the selection levers, "V"-shaped notches having the bottom slightly lower than the path of the butts of the lowered elastic jacks, while corresponding lower projections are provided in the control ring for the lowering of the intermediate jacks. The width of the notches is smaller than the width of the selection levers, so let the butt of the elastic pusher jacks enter into the V-shaped notch and be raised by the cam rising profiles whenever the pattern selector jack is not pressed by the selecting lever, thus obtaining the selective raising of the needle. The selection jacks are subdivided into groups, in each of which a butt is present on each of the butt rows, in correspondence with which rows the selection levers are located; the distance between two adjacent butts along a same row will be sufficient to permit the control of the selection lever within the time interposed between the passage of one butt and the following in front of it.
The invention is suitable for converting existing machines. In the existing raising ring cam, V-shaped notches are formed. In the existing ring cam for the lowering of the intermediate jacks, projections are added corresponding to said notches for lowering the intermediate jacks to a lower level than the needles, and for lowering the butts of the elastic jacks to the level of the V notches; selection levers are provided at the positions defined by said V notches and said projections, said levers being just a little wider than said V notches. An initial overtravel of the intermediate jack, pushed by the elastic pusher jack is provided by the butt of the latter acting on the sides of said V notches prior to the beginning of the needle rising.
BRIEF DESCRIPTION OF THE DRAWINGS
The following description and the attached drawing illustrate a practical non limitative exemplification of an embodiment of the invention. In the drawing:
FIG. 1 shows a rough partial section view on an axial plane, of the needles cylinder, approximately taken on line I--I of FIG. 2;
FIG. 2 is a rough view through line II--II of FIG. 1;
FIG. 3 is a rough section view on line III--III of FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In the drawing, numeral 6 indicates the cylinder, 8 indicates the sinkers radially slideable placed on the end of the cylinder, 10 indicates the needles provided with butts 10T and sliding within the channels of the cylinder; numeral 12 indicates the intermediate jacks, housed inside the channels of the cylinder and provided with butts 12T; numeral 14 indicates the oscillating selection jacks each one having a butt 14A . . . 14H disposed on each of the eight different horizontal levels, the jacks 14 being in groups of eight; the selection jacks 14, which are free to oscillate but do not move vertically, are associated with corresponding spring pusher-jacks 16 with butts 16T representing a typical selection system being known and applicable to the embodiment of the invention as illustrated. AI, AII, AIV indicate the yarn feeding positions. On the left of the feed AI (see the drawing FIG. 2) between said feed AI and feed AIV, a pile or pack of selection levers 18A . . . 18H is located, each selecting lever being disposed on the corresponding level on which the butts 14A . . . 14H of the jacks 14 of each group are located; these selection levers are movable specifically in vertical direction--in order to act or not to act upon respective butts 14A . . . 14H. In a symmetrical position relative to the feed AI another pile or pack of selection levers 20A . . . 20H is located between feed AI and feed AII. The pile or pack of selection levers 20 is, in respect to the feed AII, in a position similar to the one in which the selection levers 18A . . . 18H are in respect to the feed AI; similarly, the pile or pack of selection levers 18A . . . 18H is, in respect to the feed AIV, at an analogous position to that in which the selection levers 20A . . . 20H are in respect to the feed AI. In other words, the pile or pack of selection levers 18A . . . 18H is at an intermediate position between the feed AIV and AI, the pile or pack of selection levers 20A . . . 20H is intermediate between the feed AI and AII, and so on. The selection levers 18A . . . 18H, 20A . . . 20H, etc., are electronically controlled via per se known electromagnets. When a selection lever, like that indicated by 18C, has been lifted (see FIG. 1), the corresponding butt 14C is not depressed thus letting the corresponding butt 16T, engage with its corresponding lifting cam. Whan a selection lever 18 is kept lowered, it pushes the respective butt 14 towards the cylinder 6 in order to selectively act upon the respective elastic pusher-jack 16 which is thus kept pressed inside the channel. The respective butt 16T is therefore retracted towards the cylinder, missing the rising profile and remaining at the inactive level 24. Numeral 26 indicates the corresponding inactive path of butts 12T. Numeral 28 indicates the cam ring with its raising and selecting profiles acting on the butts 16T of the pushing jacks 16. The active lifting ramps 28X are symmetrical with respect to the position of the piles or packs of selection levers 18A . . . 18H, 20A . . . 20H, etc., and with respect to the feeding stations. The lifting cam profiles of the ring 28 are joined in correspondence with each pile or pack of selection levers 18A . . . 18H, 20A . . . 20H, etc., by the corresponding V notches profiles indicated by 28 18 , 28 20 , 28 22 , etc. with the bottom level slightly lower than path 24.
Numeral 30 indicates the ring which forms, with its lower part, control profiles for lowering the intermediate jacks 12, acting on butts 12T. The lay-out of the profiles is similar--but opposite--to that of the ring 28. Particularly, lower projections 30 18 , 30 20 , 30 22 , etc., of said profiles are provided in correspondence with V notches 28 18 , 28 20 , 28 22 , etc., and in correspondence with the selection levers 18A . . . 18H, 20A . . . 20H, etc.; said projections 30 18 , 30 20 , 30 22 are capable of lowering the butts 12T as low as the level of path 26.
Numeral 34, 36 indicate the two symmetrical knitting cams, for lowering butts 10T of the needles raised by the intermediate jacks which, in turn, have been lifted by the pusher jacks engaged with one of the two ramps 28X, depending upon the motion direction. Numeral 38 shows one of the knitting cams of the feed AIV, and numerals 40 and 42 indicate the knitting cams of the feed AII.
Each feed has, therefore, all the details as described for the feed AI. The working of the individual members is well known to those skilled in the art.
The machine according to the present invention operates as follows:
Assuming that the needles cylinder 6 moves in the direction of arrow D and all the selection levers of the pile or pack 18A . . . 18H are positioned to press all the respective butts 14A, 14B . . . 14H of selectors 14. The butts 16T--either coming from the path 24' imposed by the profile of cam 30, or from the inactive path 24--are all pressed against the cylinder and carried to the lower level alongside the notch 28 18 , by the protruding profile 30 18 and, therefore, they overlie the hollow of the notched profile 28 18 , without being engaged by the profile of the ramp 28X, and remain in the inactive path 24. The respective intermediate jacks coming alternatively from the path 26' or from the path 26 and lowered by the profile 30 18 will follow the inactive path 26. As a consequence, no needle will make any stitch upon this phase and its butt 10T will remain on the inactive path 44.
Assuming now that one of the selection levers, for example the one indicated as 18C (see FIG. 1) corresponding to the butt 14C of a selection jack 14, has been raised. The selection jack 14 having the butt 14C will not be pressed when alongside the profile 28 18 . The butt 16T of the relevant pusher jack 16, urged outward by the elastic force toward the position 16T 1 will enter the V notched profile 28 18 , engage the cam profile and be raised following the path 24" on the raising or lifting ramp 28X. After an initial lifting travel of the jack 16, which compensates for the gap D (See FIG. 1) created by the overtravel of the intermediate jack obtained by projection 30 18 , the said intermediate jack 12 will be raised by the above mentioned pusher 16 and will follow the path 26" and 26"' thereby lifting, in turn, the relevant needle 10; said needle, by moving onto the path 44', will reach the clearing level 44", will take the new yarn from the feeding station AI along said path 44" and will knot a new stitch while being lowered by the knitting cam 34 down on path 44"' to go back again with its butt 10T on path 44. At the same time, the intermediate jack 12, pushed downwardly by the profile of cam 30, will follow the path 26 IV , 26 V , lowering, in turn, the pusher 16 along the path 24 IV and 24 V toward the level close to the bottom of the notch 28 20 where by means of the pack or pile of levers 20A . . . 20H a new selection of needles will take place, to select whichever needle has to knit at the next feeding station AIII. The selection levers 20A . . . 20H (or others) which are in a push position, force the respective butts 16T to pass behind the ring 28 following the inactive path 24.
During the reversal of motion in the S direction--reference being made for simplicity's sake to the same figure and designations--the pushers corresponding to those pusher jacks 16 being pressed against the cylinder by the respective selection levers of pack 20A . . . 20H will follow the path 24 VI , or 24, while the butts 16T of those pusher jacks 16 being released by the respective selection levers 20A . . . 20H, will enter the V notch 28 20 , will engage the cam profile and rise following the path 24 V and 24 IV , pushing up, in turn, the respective intermediate jack 12 from the inactive path 26 up to the path 26 V , 26 IV . In this way, the corresponding needles 10 will rise following the path 44"' up to the plateau level 44" to take the yarn from the feeding station AI and knit the stitch being pushed by the knitting cam 36 along the path 44'.
The operation is cyclically repeated in the two directions and for all the present or active feeding stations.
The action of the selection levers of pressing the elastic pusher jacks 16 towards the cylinder to prevent the butt 16 from engaging the lifting profile of the ring 28 is to be exerted over the width of the notch profiles, e.g., like those indicated by 28 18 , 28 20 , 28 22 , etc., therefore said selection levers 18A . . . 18H, 20A . . . 20H, etc., must be correspondingly developed horizontally, as shown in FIG. 3, and are suitably bevelled. The control--for example electromagnetic with return spring--of the selection levers may be operated during the interval between the transit of two successive selection butts 14A . . . 14H from successive groups of selection jacks 14, which, for example, are in number of eight for each group of the illustrated disposition in the drawing. The butts 14A . . . 14H may have, for example, a diagonal or other suitable arrangement. Each selection lever 18 may be controlled a little in advance, before its relevant butt of the pusher jack 16 reaches the notch 28 18 or 28 20 or 28 22 , etc.; in fact, the butt 16T slides inside and against the ring 28 and snaps elastically into the notch upon reaching same (to be engaged by the rising ramp 28X) unless it is pressed by the relevant selection lever. All this can be achieved through an electronic and electromagnetic selection in the realization of the invention, or through conventional mechanical systems.
The invention is also--and advantageously--able to be applied to existing and conventional argyle intarsia pattern knitting machines, converted with the use of modern types of actuators (especially electronic) and packs of selection levers like those indicated by 18, 20, 22 etc. In practice, the conversion consists in replacing the controls and the selection levers--which are of limited dimensions--modifying the cam ring 28 with notches 28 18 , 28 20 , 28 22 etc., and the cam ring 30 with projections 30 18 , 30 20 , 30 22 etc.
The drawing shows only one exemplification of the invention, but the embodiments of the invention may vary in the form and dispositions though remaining within the scope of the claims.
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In order to form argyle intarsia patterns, stacked arrays of selection levers cooperate with selection butts, the levers being capable of selecting the needles to be raised. Each array of selection levers is located symmetrically between two adjacent yarn feeding stations for cooperation with one or the other feeding station to select the desired needles depending upon the direction of machine reciprocating motion. The jack lifting and lowering profiles on the respective operative cam rings are symmetrical with respect to the feeding stations and to the arrays of selection levers. The jack lifting profiles include "V" shaped notches in alignment with the selection levers, and, correspondingly, the intermediate-jack lowering profiles include "V" shaped projections provided for further lowering the intermediate jacks.
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This application is a divisional of commonly assigned, U.S. patent application Ser. No. 10/970,500 filed on Oct. 20, 2004 now U.S. Pat. No. 6,929,416, which is a divisional of U.S. patent application Ser. No. 10/379,373 filed on Mar. 4, 2003, now U.S. Pat. No. 6,827,515.
FIELD OF THE INVENTION
This invention relates to a stacker for a printer and, in particular, to methods for stacking paper tickets, vouchers and the like that exit a transaction-based printer. The invention is particularly useful, e.g., in connection with gaming and lottery printers that provide racetrack tickets, lottery tickets or the like.
BACKGROUND OF THE INVENTION
High speed printers, such as inkjet, thermal, dye sublimation and dot matrix printers are used to provide vouchers, coupons, tickets, receipts and the like (all generally referred to herein as “tickets”) to consumers. For example, when a winning lottery prize becomes relatively large, the lines at ticket sales counters become long. In addition, the number of tickets purchased by each person in the line can be relatively large. Heretofore, most point of sales (POS) and other transaction-based printers have been designed to issue one ticket, voucher, coupon or receipt at a time. Sales personnel are therefore required to remove each printed sheet manually from the printer. When a number of lottery or wagering tickets, for example, are purchased in a single transaction, the sales person must compile all of the tickets for that transaction by hand. This can be a time consuming procedure leading to errors being made and long delays in ticket sales.
It would be advantageous to provide an automatic stacking function for printers used in such environments. Such a stacking function would be particularly advantageous for high speed printers that dispense quantities of tickets, vouchers, receipts, coupons and other printed substrates. Such printers are often used in wagering and lottery terminals, as well as in other point of sale terminals such as those used to print train tickets, bus tickets, movie and theater tickets, retail coupons, and other substrates of value.
The present invention provides an automated stacker for a printer and methods for stacking tickets in a printer having the aforementioned and other advantages.
SUMMARY OF THE INVENTION
It is a primary object of the present invention to improve transaction-based printers, such as POS printers, ticket printers, and the like. It is a further object to provide a gaming and lottery printer and associated methods that will help speed the sale of tickets.
It is a still further object of the present invention to reduce the amount of manual handling required to produce a series of tickets, vouchers, coupons or other printed substrates purchased under one sale transaction.
Another object of the present invention is to provide an automatic stacker for a small transaction-based printer that does not increase the size of the printer.
These and other objects of the present invention are attained by a transaction-based printer that has a first drive for advancing a sheet through the printer in a first direction. A kicker element is adapted to contact the sheet after printing. A second drive is operatively associated with the kicker element for advancing the sheet in a second direction opposite the first direction. An output bin is provided for collecting the sheet when it is advanced in the second direction.
In another embodiment, a sheet drive is provided for advancing sheet material from a spool through a printing station and then registering the sheet in a stationary condition within a cutting station. A cutter, such as a rotary cutter, is mounted within the cutting station. The cutter can include, for example, a stationary blade and a movable blade for severing the registered sheet from the spool. A kicker element (e.g., a kicker wheel) is mounted upon a shaft within the cutting station. A clutch allows the kicker element to freely rotate in one direction as the sheet is forwarded into the cutting station. A drive system that is associated with the cutter control mechanism reverses the direction of rotation of the kicker element once the cutting operation is completed, locking the clutch and thus causing the severed sheet to be kicked into a collecting bin.
A method for stacking tickets in a printer is provided, in which sheets are driven through a printer in a first direction. The sheet is printed on, momentarily stopped, and advanced in a second direction opposite the first direction after it has been stopped. The sheet is collected in an output bin when it is advanced in the second direction.
BRIEF DESCRIPTION OF THE DRAWINGS
For a further understanding of the present invention, reference will be made to the following detailed description of the invention which is to be read in association with the accompanying drawings, wherein:
FIG. 1 is a perspective view of a point of sale printer showing the printer cover slightly raised;
FIG. 2 is a left perspective view of the printer shown in FIG. 1 with the bottom part of the printer housing being removed to further show the cutter and kicker element drive system;
FIG. 3 is a right perspective view of the printer similar to that shown in FIG. 2 further showing the sheet feed drive system;
FIG. 4 is a partial perspective view of the printer main frame with parts broken away to better illustrate the cutting station of the printer; and
FIG. 5 is a partial sectional view taken through the drive roller of the sheet feed drive.
DETAILED DESCRIPTION OF THE INVENTION
Turning now to the drawings, there is illustrated a printer, generally referenced 10 , that embodies the teachings of the present invention. It is noted that the illustrated printer is only one example embodiment of a printer that can incorporate the features of the present invention.
The printer 10 includes a rectangular shaped housing 12 upon which a hinged cover 13 is provided. The hinge is located at the back of the housing cover so that the cover can swing upwardly and rearwardly to provide ready access to a paper bin located in the rear of the printer housing. The bin is configured to accept a supply spool of paper 15 , which serves as the substrate for printing a ticket, voucher, coupon or the like. A main feed roller 17 is rotatably mounted in the cover and contains a gear 18 that is affixed to one end of feed roller shaft 19 . The feed roller gear 18 is arranged to mesh with an intermediate or idler gear 20 when the cover is closed. The idler gear 20 forms part of the main drive system of the printer and is coupled to the main drive gear 23 by means of a second idler gear 24 . The drive gear 23 is mounted upon the output shaft 25 of a drive motor that is housed within the control section 27 of the printer.
The present printer as herein described is a thermal printer, however, as should become apparent from the disclosure below, the present invention is applicable for use in any type of gaming, lottery, POS, or other transaction-based printer that is known and used in the art. For a thermal printer implementation, the paper on the supply spool is fabricated of a heat sensitive (i.e., thermal) material. The end of the spool first is threaded through a printing station 29 as illustrated in FIG. 5 and is held tightly against a thermal printing head 30 by the feed roller 17 when the cover is moved to a closed position. Sufficient friction is provided between the printing head and the feed roller to advance the paper through the printing station, where a desired image is applied to the paper based on an input from the printer control section 27 using well known thermal printing techniques.
The imaged substrate is advanced by the feed roller into the cutting station 35 ( FIG. 4 ) where the paper is registered and the feed roll drive is deactivated as the printed ticket, voucher, coupon or the like is severed from the supply spool. A rotary cutter is located in the cutting station. The cutter includes a stationary upper blade 40 and a coacting rotatable lower blade 41 ( FIG. 4 ). The paper is guided into the cutting station between the two blades and as will be described in greater detail below, and is cut from the spool by rotating the movable blade past the fixed blade. It should be appreciated that the particular type of cutter is not critical, and other types of cutters can be substituted for the rotary cutter described herein. Alternatively, precut paper stock can be used, in which case no cutter is required in the printer.
The operation of the cutter in the illustrated embodiment is independently controlled through a separate cutter drive system best illustrated in FIG. 2 and generally referenced 43 . The cutter drive system includes its own cutter drive motor 46 mounted upon the main frame 47 of the printer. The shaft 44 of the cutter drive motor passes through the side wall 48 of the frame and has a drive pinion 45 secured thereto. The drive pinion is coupled to a drive wheel 50 ( FIG. 4 ) by a pair of idler gears 51 and 52 that are arranged to turn the drive wheel at a desired speed. A pin 53 is mounted upon the outer face of the wheel and protrudes outwardly from the wheel face.
As illustrated in FIGS. 2 and 4 , a rocker arm 55 is secured to one end of the rotatable cutter blade 41 by means of a mounting hub 56 . The arm contains an elongated slot 57 in which the drive wheel pin rides. An optical sensor 58 is mounted within a housing adjacent to the drive wheel. A tab or flag 59 is carried by the drive wheel and is adapted to pass through a slit in the sensor housing to generate an output signal to the controller indicating when the rotatable blade has reached the end of cut position. At this time, the direction of rotation of the cutter motor is reversed and the rotatable cutter blade is returned to the home or start of cut position.
A gear segment 60 is carried upon the mounting hub of the rocker arm. The gear segment mates with an idler gear 62 which in turn mates with a drive gear 63 affixed to one end of a kicker roll shaft 65 that is journaled for rotation in the upper part of the printer main frame 47 . A kicker roll 67 is carried upon the kicker roll shaft and is coupled to the shaft by a one way clutch 69 . Paper that is forwarded into the cutting station will pass through a nip created between the kicker roll and a backing plate 70 that is carried by the cover. The nip is formed when the cover is brought to a fully closed position. The clutch is arranged to permit the kicker roll to rotate freely upon the kicker roll shaft when the paper is forwarded from the printing station into the cutting station and as the movable blade is moved from its home position to the end of cut position.
Upon the return stroke of the rotatable cutter blade, the rotation of the kicker roll shaft is reversed and the clutch now locks the kicker wheel to the shaft. Accordingly, the severed paper ticket, voucher, coupon or the like (the “cut sheet”) is driven by the kicker wheel through the discharge opening 75 in the cover back toward a collecting bin 77 located in the top of the cover. A sheet guide is positioned at the entrance to the bin that directs the cut sheet into the bin. The bottom wall 80 of the bin ( FIG. 1 ) is inclined downwardly and serves to direct the sheets entering the bin downwardly so that the lower portion of each sheet is captured under the top half wall 83 of the bin.
While the present invention has been particularly shown and described with reference to the preferred mode as illustrated in the drawing, it will be understood by those skilled in the art that various changes in detail may be effected therein without departing from the spirit and scope of the invention as defined by the claims.
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Methods are provided for driving sheets through a transaction-based printer. A sheet drive forwards a sheet through a printing station to a cutting station where the sheet is severed from a spool by a cutter. Movement of a kicker element is coordinated with that of the cutter so that the severed sheet is kicked into a bin located in the top cover of the printer. The printer can be, for example, an ink-jet, dot matrix, dye sublimation or thermal printer used to print tickets, vouchers, coupons or the like.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention is in the general field of improved methods of pumping viscous hydrocarbons through a pipe, such as a well-bore or a pipeline.
2. General Background
The movement of heavy crudes through pipes is difficult because of their high viscosity and resulting low mobility. One method of improving the movement of these heavy crudes has included adding to the crude lighter hydrocarbons (e.g. kerosine distillate). This reduces the viscosity and thereby improves the mobility. This method has the disadvantage that it is expensive and the kerosine distillate is becoming difficult to obtain.
Another method of improving the movement of these heavy crudes is by heating them. This requires the installation of expensive heating equipment and thus is an expensive process.
The use of oil-in-water emulsions, which use surfactants to form the emulsion, is known in the art.
U.S. Pat. No. 3,943,954 teaches lowering the viscosity of viscous hydrocarbons by adding an aqueous solution containing an anionic surfactant together with a quanidine salt and optionally with an alkalinity agent and/or a nonionic surfactant. The patent teaches that the guanidine salt is required.
Commonly assigned copending application Ser. No. 13,358, filed Feb. 21, 1979, discloses a method of transporting a viscous hydrocarbon through pipes wherein the method uses water containing an effective amount of an alkaryl sulfonate having a molecular weight below about 410. The application contains data which shows that high molecular weight sulfonates are not effective in the method.
We have found that using a C 1 -C 4 alcohol with an alkaryl sulfonate having a molecular weight of about 415 to about 470 provides a composition, which when used in water and added to a viscous hydrocarbon, provides a reduction in viscosity.
BRIEF SUMMARY OF THE INVENTION
Briefly stated, the present invention is directed to an improvement in the method of pumping a viscous hydrocarbon through a pipe wherein the improvement comprises adding from about 20 to about 80 volume percent water containing an effective amount of a combination of an alkaryl sulfonate having a molecular weight of about 415 to about 470 and a C 1 -C 4 alcohol.
DETAILED DESCRIPTION
Insofar as is known our method is suitable for use with any viscous crude oil. It is well known that crude oils often contain a minor amount of water.
The amount of water which is added to the hydrocarbon is suitably in the range of about 20 to about 80 volume percent based on the hydrocarbon. A preferred amount of water is in the range of about 30 to 60 volume percent. The water can be pure or can have a relatively high amount of dissolved solids. Any water normally found in the proximity of a producing oil-well is suitable.
Suitable alkaryl sulfonates for use in my invention have a molecular weight of about 415 to about 480 and are represented by the formula
R--Ar--SO.sub.3 M
wherein Ar is an aromatic moiety which is phenyl, tolyl, xylyl or ethylphenyl, R is a linear or branched-chain alkyl group containing 17 to 22 carbon atoms, and M is sodium, potassium or ammonium, but preferably is sodium.
The preferred alkaryl sulfonates are sodium alkylbenzene sulfonates, wherein the alkyl group contains 17 to 22, more suitably 17 to 21, and preferably 18 to 20, carbon atoms.
The alkaryl sulfonates can be natural or synthetic. Usually, they are mixtures containing alkyl groups in the carbon range specified.
Suitable alcohols are those having at least some solubility in water. From a practical viewpoint the C 4 isomers are the highest carbon number suitable. Accordingly, suitable alcohols are C 1 -C 4 aliphatic alcohols. The preferred alcohols are methanol, ethanol and isopropanol.
A suitable amount of alkaryl sulfonate is in the range of about 500 to about 10,000 parts per million based on the hydrocarbon. On the same basis the preferred amount of alkaryl sulfonate is in the range of about 1,000 to about 5,000 parts per million.
A suitable amount of alcohol is in the range of 0.1:1 to 10:1, expressed as parts by weight based on the alkaryl sulfonate. On the same basis the preferred amount of alcohol is in the range of 0.5:1 to 5:1.
In order to illustrate the nature of the present invention still more clearly the following examples will be given. It is to be understood, however, that the invention is not to be limited to the specific conditions or details set forth in these examples except insofar as such limitations are specified in the appended claims.
The following materials were used in the tests described herein:
Crude Oil--Goodwin lease crude from Cat Canyon oil field, Santa Maria, Calif.
Water--Goodwin synthetic (Water prepared in laboratory to simulate water produced at the well. It contained 5000 ppm total solids.)
Viscosities were determined using a Brookfield viscometer, Model LVT with No. 3 spindle. The procedure is described below.
The following materials were used in the tests:
Methyl alcohol--reagent grade.
Surfactant "A"--an alkylbenzene sulfonate having a molecular weight in the range of 415-430.
Surfactant "B"--an alkylbenzene sulfonate having a molecular weight in the range of 440-470.
Surfactant "C"--an alkylbenzene sulfonate having a molecular weight in the range of 490-510.
TEST PROCEDURE
Three hundred ml of crude oil, preheated in a large container to about 93° C. in a laboratory oven, was transferred to a Waring blender and stirred at medium speed until homogeneous. Stirring was stopped, temperature recorded, and the viscosity measured using the Brookfield viscometer at RPM's (revolutions per minute) of 6, 12, 30 and 60 and then back down 30, 12, and 6 RPM. Viscosity was calculated by using a multiplication factor of 200, 100, 40 and 20 for the respective speeds times the dial reading on the viscometer.
It may be well to mention that the final result at 6 RPM is an indication of the stability of the solution being tested.
The test was repeated using 300 ml crude oil plus 300 ml of the Goodwin synthetic water containing varying amounts of the described surfactants and combinations of the described surfactants with methyl alcohol.
An additional procedure was used on the crude oil-water-surfactant composition and the crude oil-water-surfactant-alcohol composition. This procedure consisted of stirring the emulsions a second time, allowing them to set for two minutes upon completion of stirring, then making the viscosity determination as previously. This procedure is a more severe test of long term stability for emulsions.
The difference in viscosity values on the crude alone in the examples is due to the varying amount of water naturally present in the crude. For this reason the viscosity value of the crude alone was obtained in each example. The crude corresponded to that used in combination with the aqueous surfactant.
EXAMPLE 1
This example is both comparative and illustrative. It shows the beneficial effect of adding methyl alcohol to Surfactant "A". Viscosity values were obtained on the following:
(a) 300 ml crude oil alone,
(b) 300 ml crude oil plus 300 ml water containing 1.21 g (62 percent active) Surfactant "A" (2500 ppm), and
(c) 300 ml crude oil plus 300 ml water containing 1.21 g (62 percent active) Surfactant "A" (2500 ppm) and 2.0 ml methyl alcohol (˜5300 ppm).
The results for runs (a) and (b) are shown in Table I while the results for run (c) are shown in Table II.
TABLE I______________________________________ Crude Oil Plus 300 ml Water Containing 1.21 gCrude Oil Alone (62% Active) Surfactant "A"(300 ml) (2500 ppm)Viscosity, cp Viscosity, cpRPM No. 1 No. 1 No. 2______________________________________ 6 11,200 800 12,40012 9,950 650 O.S.30 O.S. 320 O.S.60 O.S. 204 O.S.30 O.S. 300 O.S.12 9,500 580 4,100 6 9,500 1,600 5,200______________________________________ O.S. = Offscale Test Temperature 87° C. O.S. = Offscale Test Temperature 74° C., 66° C. Composition foamed badly
TABLE II______________________________________Crude Oil Plus 300 ml Water Containing1.21 g (62% Active) Surfactant "A" (2500 ppm)And 2.0 ml Methyl Alcohol Viscosity, cpRPM No. 1 No. 2______________________________________ 6 140 20012 180 10030 28 5660 36 5230 28 3212 70 80 6 80 140______________________________________ Test Temperature 78° C., 74° C. Composition had very little foam
EXAMPLE 2
This example is both comparative and illustrative. It shows the beneficial effect of adding methyl alcohol to Surfactant "B". Viscosity values were obtained on the following:
(a) 300 ml crude oil alone,
(b) 300 ml crude oil plus 300 ml water containing 1.21 g (62 percent active) Surfactant "B" (2500 ppm), and
(c) 300 ml crude oil plus 300 ml water containing 1.21 g (62 percent active) Surfactant "B" (2500 ppm) and 2.0 ml methyl alcohol (˜5300 ppm).
The results for runs (a) and (b) are shown in Table III while the results for run (c) are shown in Table IV.
TABLE III______________________________________ Crude Oil Plus 300 ml Water Containing 1.21 g (62% Active) Surfactant "B"Crude Oil Alone (2500 ppm)(300 ml) Viscosity, cpRPM Viscosity, cp No. 1 No. 2______________________________________ 6 11,880 960 2,10012 O.S. 1,200 1,65030 O.S. 800 1,32060 O.S. 100 13030 O.S. 112 17212 O.S. 160 260 6 10,400 340 360______________________________________ O.S. = Offscale Test Temperature 91° C. Test Temperature 78° C., 70° C. Composition had moderate foam
TABLE IV______________________________________Crude Oil Plus 300 ml Water Containing1.21 g (62% Active) Surfactant "B" (2500 ppm)And 2.0 ml Methyl Alcohol Viscosity, cpRPM No. 1 No. 2______________________________________ 6 40 16012 50 8030 60 5260 52 3630 56 6012 180 70 6 360 340______________________________________ Test Temperature 77° C., 73° C. Composition had very little foam
EXAMPLE 3
This example is comparative in that it shows that addition of methyl alcohol has no beneficial effect on an alkylbenzene sulfonate having a molecular weight of 490-510 (Surfactant "C"). Viscosity values were obtained on the following:
(a) 300 ml crude oil alone,
(b) 300 ml crude oil plus 300 ml water containing 1.21 g (62 percent active) Surfactant "C" (2500 ppm), and
(c) 300 ml crude oil plus 300 ml water containing 1.21 g (62 percent active) Surfactant "C" (2500 ppm) plus 2.0 ml methyl alcohol (˜5300 ppm).
The results for runs (a) and (b) are shown in Table V while the results for run (c) are shown in Table VI.
TABLE V______________________________________ Crude Oil Plus 300 ml Water Containing 1.21 g (62% Active) Surfactant "C"Crude Oil Alone (2500 ppm)(300 ml) Viscosity, cpRPM Viscosity, cp No. 1 No. 2______________________________________ 6 12,260 O.S. O.S.12 O.S. O.S. O.S.30 O.S. O.S. O.S.60 O.S. O.S. O.S.30 O.S. O.S. O.S.12 O.S. O.S. O.S. 6 11,600 O.S. O.S.______________________________________ O.S. = Offscale Test Temperature 90° C. O.S. = Offscale Test Temperature 79° C., Composition failed
TABLE VI______________________________________Crude Oil Plus 300 ml Water Containing1.21 g (62% Active) Surfactant "C" (2500 ppm)And 2.0 ml Methyl Alcohol Viscosity, cpRPM No. 1 No. 2______________________________________ 6 O.S. O.S.12 O.S. O.S.30 O.S. O.S.60 O.S. O.S.30 O.S. O.S.12 O.S. O.S. 6 O.S. O.S.______________________________________ O.S. = Offscale Test Temperature 78° C., Composition failed
The test results from the examples show clearly that addition of a small amount of methyl alcohol to Surfactants "A" and "B" provided a significant reduction in viscosity. The test results show that addition of methyl alcohol to Surfactant "C" (molecular weight 490-510) did not provide any improvement.
Examples 1-3 are repeated substituting ethyl alcohol and isopropyl alcohol for methyl alcohol. Similar results are obtained.
Thus, having described the invention in detail, it will be understood by those skilled in the art that certain variations and modifications may be made without departing from the spirit and scope of the invention as defined herein and in the appended claims.
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An improvement in the method of transporting viscous hydrocarbons through pipes is disclosed. Briefly, the method comprises adding water containing an effective amount of a combination of an alkaryl sulfonate having a molecular weight of 415 to 470 and a C 1 -C 4 alcohol.
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This application is a continuation-in-part of application for U.S. Letters Patent, Ser. No. 514,248 filed on Apr. 25, 1990, now abandoned, which, in turn, is a continuation-in-part of application for U.S. Letters Patent, Ser. No. 371,635 filed on June 26, 1989, now U.S. Pat. No. 4,940,592 issued on July 10, 1990.
BACKGROUND OF THE INVENTION
The increased use of microwaves for cooking has given rise to a large market in microwavable foods. While the advantage of microwave cooking over convection oven cooking is the time savings, the disadvantage heretofore has been that flavored goods do not develop the flavoring expected with convection oven cooking.
Heretofore, when using microwave ovens for cooking foodstuffs containing flavoring and browning additives or flavoring and browning formation additives, the food to be cooked taken in combination with additives therefor did not have the proper time-temperature-heat transfer variable (e.g., heat capacity, thermal conductivity, viscosity and density) combination for the added flavoring composition to effectively impart, augment or enhance flavor to the resulting product, e.g., chewing gum, beverage or foodstuff. Therefore, for a microwave system to work, the physical heat and mass transfer conditions must be such that the added flavor values must not be driven off or destroyed and must be properly imparted to the foodstuff, beverage or chewing gum.
The reaction responsible for chocolate flavor formation during convection oven cooking is the reaction between sugar, leucine and phenyl alanine which results in the creation of various reaction products including aldol condensation products such as COCAL® (a Registered Trademark of International Flavors & Fragrances Inc.) having the structure: ##STR1##
Although the prior art does take advantage of the reaction between reducing sugars and amino acids, it has not made any correlation of reaction rates needed for formation of a substantive strong chocolate flavor with reaction variables such as time, pH, solvent, amino acid reactivity or sugar reactivity.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cut-away side elevation view (in schematic form) of a microwave oven containing a reaction vessel prior to and during the carrying out of that part of the process of my invention which involves the formation of the chocolate flavor.
FIG. 2 is a block flow diagram showing the steps, in schematic form, for carrying out that aspect of the process of my invention for forming flavored foodstuffs and indicating the multiple means (apparatus elements) useful in carrying out that aspect of the process of my invention for forming chocolate flavored foodstuffs whereby an uncooked article is admixed with chocolate flavor which was previously formed by means of microwave heating.
FIG. 3 is a block flow diagram showing the steps, in schematic form, for carrying out another aspect of the process of my invention; and indicating the multiple means (apparatus elements) useful in carrying out that aspect of the process of my invention wherein flavor precursor is heated via microwave heating means and the resulting flavor is admixed into the matrix of an uncooked food article prior to storage or subsequent heating.
FIG. 4 is the GLC profile for the chocolate flavor reaction product (freon extract) produced by means of convection heating (and not by means of microwave radiation) according to Example V.
FIG. 5 is the GLC profile for the reaction product of Example V produced by means of microwave radiation.
SUMMARY OF THE INVENTION
My invention is directed to a process for carrying out microwave production of a chocolate flavoring product, the product produced thereby and foodstuffs, beverages and chewing gums containing said product. The process comprises the steps of:
(a) providing a composition of matter consisting essentially of precursors of a reaction flavor (preferably a chocolate reaction flavor; e.g., a sugar, leucine and phenyl alanine) and a solvent capable of raising the dielectric constant of the reaction mass to be heated via microwave radiation (such as glycerine, propylene glycol, mixtures of glycerine and propylene glycol, mixtures of glycerine and ethanol, and mixtures of propylene glycol and ethanol) and water;
(b) exposing the resulting mixture to microwave radiation for a period of time whereby the resulting product is caused to have a chocolate flavor;
(c) providing a chewing gum base, a beverage base or a foodstuff base (e.g., dough);
(d) admixing the reaction product of (b) with the base of (c); and
(e) optionally, reheating the resulting product to form an edible foodstuff.
My invention is also directed to the products produced according to such process.
In carrying out my invention, a chocolate flavor is produced by means of microwave heating of a sugar, leucine and phenyl alanine Such chocolate flavor necessarily contains the compound COCAL® a Registered Trademark of International Flavors & Fragrances Inc. having the structure: ##STR2##
The precursours for producing such a chocolate flavor are phenyl alanine having the structure: ##STR3## leucine having the structure: ##STR4## and a sugar shown by the letter:
S
The reaction for forming the chocolate flavor prior to mixing with the beverage chewing gum base or foodstuff base is as follows: ##STR5## wherein the symbol:
R
is indicative of other reaction products being formed in the formation of the chocolate flavor. In causing the process of my invention to be operable, the proper solvent-reactant makeup must be employed. Necessarily, the reaction solvent physical properties are interrelated.
Thus, with respect to the solvents utilizable in the practice of my invention, the solvent system is, in the alternative, as follows:
(i) glycerine;
(ii) propylene glycol;
(iii) mixtures of glycerine and propylene glycol in the ratio of from about one part glycerine:99 parts propylene glycol up to about 99 parts glycerine:1 part propylene glycol;
(iv) mixtures of glycerine and ethanol with the ratio of glycerine:ethanol being from about 99:1 glycerine:ethanol up to about 50:50 ethanol:glycerine; and
(v) mixtures of propylene glycol and ethanol with the ratio of propylene glycol:ethanol being from about 99 parts propylene glycol:1 part ethanol up to about 50 parts propylene glycol:50 parts ethanol.
DETAILED DESCRIPTION OF THE INVENTION
My invention herein has shown that there is a strong relationship between the sugar reactivity and the particular amino acid utilized for production of chocolate flavor.
I have also found that chocolate flavor precursors, that is, phenyl alanine, leucine and a sugar such as ribose, rhamnose or cerelose produce an unexpectedly, advantageously substantive and strong and "natural-like" chocolate flavor.
My invention, carried out at pH's in the range of 9-13 involves amino acid degradation followed by aldol condensation, interalia. Thus, phenyl alanine and leucine are reacted in the presence of a sugar such as ribose, rhamnose and cerelose at a pH in the range of 9-13. The reaction for the purposes of carrying out same uses microwave heating in a specific solvent. The use of microwave heating gives rise to an unexpectedly and advantageously unobvious reaction product; as compared to convection heating as shown in Table III(A) in Example V, infra. An unexpected finding in my invention is that the solvent in which the flavor is formed dramatically affects the rate of reaction. Aprotic solvents, such as triacetin and vegetable oil, are useless in such a reaction system since the reactants are not soluble in the solvent. Polar protic solvents are amongst the solvents in which the reactants are soluble; however, not all members of this solvent class are useful in carrying out the reaction, to wit: ##STR6## wherein the symbol:
S
represents a sugar and the symbol:
R
represents other reaction products necessary to create a chocolate flavor.
Both water and ethanol are unacceptable, per se as solvents since the rate of the reaction: ##STR7## in these solvents is on the order of hours.
In propylene glycol and glycerine the rate of the reaction: ##STR8## is rapid, achieving the desired chocolate flavor formation in 40 seconds to 2 minutes (120 seconds).
In application for U.S. Letters Patent, Ser. No. 295,450 filed on Jan. 10, 1989 (now U.S. Pat. No. 4,882,184 issued on Nov. 21, 1989) it was shown that the solvent in which the Maillard browning is run dramatically affects the rate of browning. It was also shown there that aprotic solvents, such as triacetin and vegetable oil, were useless in the browning reaction systems since the reactants in the Maillard reaction were not soluble in the solvent. Polar protic solvents were set forth to be amongst the solvents in which the Maillard reactants are soluble; and it was further indicated that not all members of this solvent class are useful for microwave browning. It was further indicated that both water and ethanol, per se, are unacceptable as solvents since the rate of the browning reaction in these solvents is on the order of hours. It was further indicated that in propylene glycol and glycerine the rate of browning is rapid, achieving the desired coloration in 40 seconds to 2 minutes (120 seconds).
With respect to the sugar components of the reactants, whereby the reaction: ##STR9##
The preferred sugars are:
(i) ribose;
(ii) rhamnose; and
(iii) cerelose.
With regard to the amino acid precursors, the phenyl alanine has the structure: ##STR10## and the leucine has the structure: ##STR11##
The reaction of the amino acids with the sugars, ribose, rhamnose and/or cerelose, for example, the reaction: ##STR12## is carried out in a solvent which is capable of raising the dielectric constant of the reaction mass to be heated in a period of time under 120 seconds.
Thus, FIG. 1 is a schematic diagram of a reaction vessel located in a microwave oven during the carrying out of the process of our invention. The reaction mass 20 is contained in microwave oven 138, more specifically, in reaction vessel 10 wherein microwave source 42 emits energy substantially perpendicular to the level of the reaction mass 20 which is stirred using stirring means 22. The microwave energy passes into the reaction mass 20 and causes the reaction to take place, to wit: ##STR13## whereby a chocolate flavor is produced which includes the compound having the structure: ##STR14##
The reaction vessel 10 rests at location 39 in the microwave oven 40.
Another aspect of my invention flavor precurser materials which would include leucine, phenyl alanine and sugar may be reacted in the microwave oven and then the reaction product may be admixed with molten fat and emulsifier. The resulting product may then further be heated to its molten state and mixed with additional flavor materials. Into the mixing operation texturizer may be placed. Drum chilling may result in a product which is useful in the practice of my invention. Spray chilling of the resulting mixed texturized product causes the spray chilled flavor product to be available for use as a flavorant.
Examples of fatty materials useful in this aspect of the process of my invention are set forth, supra, and their respective melting points are as follows:
TABLE I______________________________________Fatty Material Melting Point Range______________________________________Partially hydrogenated 141-147° F.cotton seed oilPartially hydrogenated 152-158° F.soybean oilPartially hydrogenated 136-144° F.palm oilMono and diglycerides 136-156° F.Glycerol monostearate 158° F.Glycerol monopalmitate 132° F.Propylene glycol monostearate 136° F.Polyglycerol stearate 127-135° F.Polyoxyethylene sorbitol beeswax 145-154° F.derivativesPolyoxyethylene sorbitan 140-144° F.esters of fatty acidsSorbitan monostearate 121-127° F.Polyglycerol esters of 135-138° F.fatty acidsBeeswax 143-150° F.Carnauba wax 180-186° F.______________________________________
Texturizers include precipitated silicon dioxide, for example, SIPERNAT® 50S (bulked density 6.2 pounds per cubic foot; particle size 8 microns; surface area 450 square meters per gram manufactured by the Degussa Corporation of Teterboro, N.J.). Other silicon dioxide texturizers are as follows:
SIPERNAT® 22S manufactured by Degussa Corporation;
ZEOTHIX® 265 manufactured by J. M. Huber Corporation of Havre de Grace, Md.;
CAB-0-SIL® EH-5 manufactured by the Cabot Corporation, of Tuscola, Ill.;
FIG. 2 sets forth a schematic block flow diagram of the process of my invention whereby, e.g., glycerine at 302 (which may be preheated) and reactants, leucine, phenyl alanine and sugar at location 301 are mixed in mixing means 304. The resulting mixture is then placed in microwave heating means 138 where heating takes place using the microwave radiation. The resulting chocolate flavored product may then be utilized at coating means 306. Dough is mixed at mixing means 309 and shaped into pre-cooked uncoated food articles at shaping means 307. The shaped dough is then transported to coating means 306 where the reaction product from 138 is coated onto the shaped pre-cooked food articles. The now coated shaped pre-cooked food articles are then further cooked (if desired) in heating means 311. The resulting chocolate flavored articles are then transported for marketing to location 310. The articles may be transported in their uncooked state (eliminating heating means 311) and instead, may be transported in a frozen state or at room temperature if practicable.
FIG. 3 sets forth a schematic block flow diagram of another aspect of the process of my invention whereby flavor precursor liquid containing leucine, phenyl alanine, sugar and a mixture of glycerine and propylene glycol at location 401 are placed in microwave heating means 138. The resulting product is then heated via microwave radiation to form a chocolate flavor. The chocolate flavor is transported from microwave heating means 138 to mixing means 405 where the liquid chocolate flavor is mixed with dough composition from location 403. The resulting product, dough composition containing flavor is shaped at location 407 and then, if desired, the resulting product is reheated at location 411 either via microwave heating or via convection heating- The resulting product (heated or not) is then transported for marketing to location 410 (the product being at room temperature frozen or preheated).
In summary, the solvents useful in carrying my invention have dielectric constants which cause the heating of the reaction mass via microwave radiation to take place in under 120 seconds (in the range of from about 40 seconds up to about 120 seconds). Furthermore, the solvents useful in carrying out my invention have dielectric constants which cause the reaction using the microwave radiation to take place in a relatively short period of time depending on the amount of solvent utilized with the reaction mass. The weight ratios of sugar:amino acid:solvent may vary as follows:
(a) the weight ratio of amino acid (e.g., phenyl alanine and leucine) to sugar may vary from about 0.5:1 up to about 1.5:0.5 (or 3:1).
(b) The weight ratio of sugar:solvent may vary from about 1:12 up to about 1:5 as the preferred range. Higher amounts of solvent may be utilized with practicable results as will be seen from an examination of the examples, infra.
Referring to FIGS. 4 and 5, FIGS. 4 and 5 are GLC profiles of reaction products produced according to Example V. FIG. 4 is the GLC profile of the reaction product produced by means of convection heating. FIG. 5 is the GLC profile of the chocolate flavor reaction product produced by means of microwave heating according to Example V, infra.
In FIG. 5, the peak indicated by reference numeral 701 is the peak for acetaldehyde. The peak indicated by reference numeral 702 is the peak for the freon extraction agent.
The peak indicated by reference numeral 703 is the peak for isovaleraldehyde. The peak indicated by reference numeral 704 is the peak for 2,5-dimethyl pyrazine. The peak indicated by reference numeral 705 is the peak for benzaldehyde. The peak indicated by reference numeral 706 is the peak for alpha-methyl styrene. The peak indicated by reference numeral 707 is the peak for 2,3,5-trimethyl pyrazine. The peak indicated by reference numeral 708 is the peak for phenyl acetaldehyde. The peak indicated by reference numeral 709 is the peak for 2-acetyl pyrrole. The peak indicated by reference numeral 710 is the peak for n-nonanal. The peak indicated by reference numeral 711 is the peak for 5-methyl-2-isopropyl-2-hexenal. The peak indicated by reference numeral 712 is the peak for an unknown-aromatic. The peak indicated by reference numeral 713 is the peak for 2-butyl-3-methyl pyrazine. The peak indicated by reference numeral 714 is the peak for a substituted methyl pyrazine. The peak indicated by reference numeral 715 is the peak for isoamyl dimethyl pyrazine. The peak indicated by reference numeral 716 is the peak for a mixture of glycol esters of isobutyric acid. The indicated by reference numeral 717 is the peak for COCAL® the compound having the structure: ##STR15## The peak indicated by reference numeral 718 is the peak for diethyl phthalate. The peak indicated by reference numeral 719 is for 2-benzylidene heptenal. The peak indicated by reference numeral 720 is the peak for dibutyl phthalate. The peak indicated by reference numeral 721 is for an unsaturated hydrocarbon.
With reference to FIG. 5, the peak indicated by reference numeral 801 is for acetaldehyde. The peak indicated by reference numeral 802 is for the freon extraction material. The peak indicated by reference numeral 803 is for isovaleraldehyde. The peak indicated by reference numeral 804 is for 2,5-dimethyl pyrazine. The peak indicated by reference numeral 805 is for benzaldehyde. The peak indicated by reference numeral 806 is for ethyl isovalerate. The peak indicated by reference numeral 807 is for alpha-methyl styrene. The peak indicated by reference numeral 808 is for 2,3,5-trimethyl pyrazine. The peak indicated by reference numeral 809 is for phenyl acetaldehyde. The peak indicated by reference numeral 810 is for 2-acetyl pyrrole. The peak indicated by reference numeral 811 is for n-nonanal. The peak indicated by reference numeral 812 is for 5-methyl-2-isopropyl-2-hexenal. The peak indicated by reference numeral 813 is for 2-butyl-3-methyl pyrazine The peak indicated by reference numeral 814 is for a substituted methyl pyrazine. The peak indicated by reference numeral 815 is for isoamyl dimethyl pyrazine. The peak indicated by reference numeral 816 is for a mixture of glycol esters of isobutyric acid. The peak indicated by reference numeral 817 is for COCAL® having the structure: ##STR16## The peak indicated by reference numeral 818 is for diethyl phthalate. The peak indicated by reference numeral 819 is for dibutyl phthalate. The peak indicated by reference numeral 820 is for an unsaturated hydrocarbon.
It should be noted that an additional advantage achieved in practicing our invention wherein the flavor precursor liquid composition is coated onto uncooked baked goods foodstuffs is that water evaporation is retarded when the resulting coated product is cooked in a microwave oven. This advantage, too is unexpected, unobvious and advantageous.
The principles given above are illustrated in the following examples.
EXAMPLE I
Into 100 ml beakers were placed exactly 40.4 g of solvent. Each beaker was irradiated with 2,450 MHz microwave radiation for 20 seconds, afterwhich the solvents temperature was measured. Experiments were run in triplicate. The results for several solvents are set forth in the following Table II.
TABLE II______________________________________SOLVENT TEMPERATURE (°C.)______________________________________Propylene glycol 91Glycerine 88Ethanol 78Water 61Triacetin 80______________________________________
EXAMPLE II
Blotters weighing 0.61 g were dosed with 0.10 g of test solutions. The test solutions are each placed on the center of each of the blotters. Blotters spotted in this manner were irradiated with 2450 MHz microwave (750 watts) radiation for various periods of time, starting at 20 seconds. The results of testing variables are summarized in Table III.
The microwave radiation source is a 750 watt Amana RADARANGE® Microwave Oven (trademark of the Amana Corporation).
TABLE III__________________________________________________________________________ AMINOAMINO ACID SUGAR SOLVENT pH ADJUSTMENTENTRYACIDS WEIGHT SUGAR WEIGHT SOLVENT WEIGHT pH AGENT__________________________________________________________________________II-1 PHENYL RIBOSE 4.5 g ETHANOL 16 g 7-8 NaHCO.sub.3ALANINE 5.0 g GLYCERINE 25 g (MW84)(MW 131.2)LEUCINE 4.0 g(MW 165.2)II-2 PHENYL RHAMNOSE 5.5 g ETHANOL 16 g 7-8 NaHCO.sub.3ALANINE 5.0 g GLYCERINE 75 gLEUCINE 4.0 gII-3 PHENYL RHAMNOSE 5.5 g ETHANOL 16 g 7-8 NaHCO.sub.3ALANINE 5.0 g GLYCERINE 25 gLEUCINE 4.0 gII-4 PHENYL RHAMNOSE 5.5 g ETHANOL 16 g 7-8 NaHCO.sub.3ALANINE 5.0 g GLYCERINE 75 gLEUCINE 4.0 gII-5 PHENYL CERELOSE 5.5 g ETHANOL 16 g 7-8 NaHCO.sub.3ALANINE 5.0 g GLYCERINE 25 gLEUCINE 4.0 gII-6 PHENYL CERELOSE 5.5 g ETHANOL 16 g 7-8 NaHCO.sub.3ALANINE 5.0 g GLYCERINE 75 gLEUCINE 4.0 gII-7 PHENYL CERELOSE 11.0 g ETHANOL 16 g 7-8 NaHCO.sub.3ALANINE 5.0 g GLYCERINE 75 gLEUCINE 4.0 g__________________________________________________________________________ pH ADJUSTMENT MICROWAVE COLOR ENTRY AGENT WEIGHT TIME APPEARANCE AROMA__________________________________________________________________________ II-1 2.7 g 20 sec. TAN MALTY BURNT COCOA II-2 2.7 g 20 sec. YELLOW FAINT CHOCOLATE 40 sec. LIGHT BROWN FAINT CHOCOLATE II-3 5.4 g 20 sec. LIGHT BROWN CHOCOLATE 40 sec. BROWN CHOCOLATE II-4 4.5 g 20 sec. BROWN CHOCOLATE 40 sec. DARK BROWN DARK COCOA II-5 5.4 g 20 sec. LIGHT YELLOW NONE 40 sec. LIGHT BROWN FAINT CHOCOLATE 60 sec. NO CHANGE II-6 5.4 g 20 sec. BROWN YELLOW NONE 40 sec. BROWN CHOCOLATE 60 sec. DARK BROWN DARK CHOCOLATE II-7 5.4 g 20 sec. NONE NONE 40 sec. TAN FAINT CHOCOLATE 60 sec. LIGHT BROWN MILK__________________________________________________________________________ CHOCOLATE
EXAMPLE III
Formation of Drum Chilled Chocolate Flavor Powder
The following mixture is prepared:
______________________________________Ingredients Parts by Weight______________________________________Sugar-amino acid composition 30 gramsof Example II-6 (10.0 gramsphenyl alanine, 8.0 gramsleucine and 11 grams cerelose:admixed with 60 grams of a50:50 mixture of glycerineand propylene glycol; heatedin a 1050 watt microwave ovenfor 4 minutes.20% MYVEROL ® 1806 in 24 gramsDURKEE ® 17 (MYVEROL ® isa fatty acid mono glycerideand DURKEE ® 17 is a stearicacid ester manufactured by theGlidden-Durkee Corporation ofSt. Louis, Missouri)SIPERNAT ® 50S (a precipitated 6 gramssilicon dioxide compositionhaving a bulk density of 6.2 poundsper cubic foot; an average particlesize of 8 microns; and a surfacearea of 450 square meters pergram manufactured by theDegussa Corporation of Teterboro,New Jersey)______________________________________
The flavor composition is intimately admixed with the SIPERNATE® 50S in a Hobart mixer (No. 1 speed for 5 minutes). The mix becomes a mass of paste and the resulting mass is intimately admixed with the mixture (30% MYVEROL® 1806 and 70% STEARINE® 17).
The resulting product is drum chilled at a speed of 5 units in a small unit drum-drier producing 0.5 pounds per minute. The temperature of the feed is 170° F. The drum-drier is:
Blaw-Knox Model 639.
The drum chilled films are crushed and sifted through a Baker's screen basket and then sieved through a No. 10 sieve.
EXAMPLE IV
Production of Chocolate Cake
The following materials are utilized in various combinations as set forth in Examples IV(A), IV(B) and IV(C), infra.
______________________________________Ingredients Parts by Weight______________________________________Egg 100 gWater 300 gCorn Oil 100 gFlavor Product (of 255 gExample II)Sodium chloride 2 gBaking powder 3 gCRISCO ® (a trademark of 40 gthe Procter & Gamble Companyof Cincinnati, Ohio)Sugar 200 gBaker's chocolate 4.5 gProduct of Example III 0.5 g______________________________________
EXAMPLE IV(A)
The egg, water, corn oil, flavor precursor mixture, salt, baking soda, CRISCO® shortening, sugar and melted baker's chocolate are intimately admixed.
EXAMPLE IV(B)
The egg, water, corn oil, flavor precursor composition of Example II-6, salt, baking soda, CRISCO® shortening, sugar, melted baker's chocolate and the product of Example III are intimately admixed.
EXAMPLE IV(C)
The melted baker's chocolate and product of Example III are intimately admixed. The mixture is added to corn oil, CRISCO® and shortening. Then egg, water, sodium chloride, baking soda and flour is added and the resulting product is intimately admixed.
Doughs' from Examples IV(A), IV(B) and IV(C) were baked separately in a 1050 watt microwave oven for 12 minutes turning 90 degrees after six minutes.
In a blind panel test:
(i) cakes (A) and (B) were judged to be equal to each other by taste and room aroma; and
(ii) cake (C) was unanimously judged to be superior in chocolate taste and room aroma with reference to cakes (A) and (B), being more natural and having a strength about twice that of (A) and (B).
On an organoleptic scale of 1-10 (with 1 being the least preferred and 10 being the most preferred) cake (A) was given a value of 7; cake (B) was given a value of 7 and cake (C) was given a value of 10.
EXAMPLE V
Into two 200 ml beakers were placed two samples of the following mixture of ingredients:
______________________________________Ingredients Weight______________________________________Phenylalanine 5.0 gramsLeucine 4.0 gramsEthyl alcohol 16.0 gramsGlycerine 75.0 gramsSodium bicarbonate 5.4 gramsCerelose 5.5 grams.______________________________________
Each of the solutions was stirred at 40° C. for one hour; until most of the ingredients dissolved. The resulting solutions remained cloudy and were therefor filtered. The resulting supernatant liquids were treated as follows:
(a) 22 grams of the solution was treated in a microwave oven until brown (total time: 30 seconds);
(b) 22 grams of the solution was treated on a hot plate at 82-85° C. for a period of 45 minutes until it was the same color as the sample of (a).
Both solutions (a) and solutions (b) were tested by a taste panel. The taste panel found that both solutions had good chocolate character. The solution of (b) was more sweet and milk chocolate-like. The solution of (a) had a dark bitter chocolate nuance absent from the solution of (b).
FIG. 4 sets forth a GLC profile of solution (a) the analysis for which is set forth on page 5, supra. FIG. 5 sets forth the GLC profile of solution (b) the analysis of which is set forth on page 5, supra.
The microwave radiation source is a 750 watt AMANA RADARANGE® Microwave Oven (trademark of the Amana Corporation).
The following Table III(A) sets forth a comparison of the quantities of the various products produced via convection heating and via microwave heating using the same reaction ingredients as set forth in this example, supra:
TABLE III(A)__________________________________________________________________________RETENTION TIME AREA PERCENTHEATED MICROWAVE HEATED MICROWAVE(FIG. 4) (FIG. 5) COMPOUND (FIG. 4) (FIG. 5)__________________________________________________________________________ 3.15 3.55 acetaldehyde 0.82 1.18-- 4.45 ethyl acetate 0.05 2.12 4.25 5.06 isovaleraldehyde 1.20 1.54 4.34 -- 2-methyl butanal 0.19 0.10-- 7.24 ethyl lactate -- 0.16-- 7.34 2-methyl pyrazine -- 0.22 9.31 10.13 2,5-dimethyl pyrazine 8.62 8.17-- 10.30 2,3-dimethyl pyrazine -- 0.1211.02 11.43 unknown molecular weight:142 0.88 0.3711.24 12.05 benzaldehyde 2.10 1.61-- 12.39 ethyl isovalerate -- 0.2212.58 13.41 alpha-methyl styrene 1.97 4.3913.28 14.10 2,3,5-trimethyl pyrazine 1.29 2.3614.59 15.39 benzyl alcohol 0.14 0.1315.16 15.55 phenyl acetaldehyde 13.48 3.00-- 16.44 2-acetylpyrrole 0.05 0.6819.22 20.03 nonanal 0.88 0.2019.59 20.40 5-methyl-2-isopropyl-2- 0.26 1.66 hexenal isomer20.21 21.02 5-methyl-2-isopropyl-2- 0.29 0.68 hexenal isomer22.35 -- benzyl acetate 0.10 ---- 24.31 isoamyl pyrazine -- 0.76-- 26.10 quinoxaline -- 0.2426.18 26.58 unknown-aromatic 1.84 0.13-- 27.33 2-phenyl furan -- 0.30-- 28.16 4-phenyl-2-butanone 0.08 0.35-- 28.33 ethyl phenyl acetate -- 0.0128.43 29.23 2-butyl-3-methyl pyrazine 0.43 1.7728.55 29.38 substituted methyl pyrazine 0.35 2.2129.34 30.15 substituted methyl pyrazine 3.42 4.8033.21 34.02 isoamyl dimethyl pyrazine 6.58 7.7736.16 36.54 a glycol ester of 1.61 0.80 isobutyric acid37.30 38.09 a glycol ester of 3.40 1.45 isobutyric acid44.23 45.02 COCAL ® 1.55 3.3749.35 50.15 unknown 6.29 1.2850.19 50.56 diethyl phthalate 3.01 0.4653.14 53.55 unknown 1.49 4.4854.24 -- 2-benzylidene heptanal 3.20 --71.32 72.11 dibutyl phthalate 8.67 4.9178.17 78.57 unsaturated hydrocarbon 9.01 7.1078.39 79.17 unsaturated hydrocarbon 2.45 1.99 85.70 73.09__________________________________________________________________________
EXAMPLE VI
Blotters weighing 0.61 grams were dosed with 0.10 grams of test solutions. The test solution was placed on the center of the blotter. Blotters spotted in this manner were irradiated with 2450MHz microwave (750 watts) radiation for various periods of time, starting at 20 seconds. The results of testing variables are summarized in Tables IV, V, VI, VII, VIII and IX.
The microwave radiation source is a 750 watt Amana RADARRANGE® microwave oven.
TABLE IV__________________________________________________________________________ Amino Amino Sugar SolventExperiments Acid Acid Wt. Sugar Wt. Solvent Wt. pH__________________________________________________________________________1 Proline 3.7 g Rhamnose 5.3 g Ethanol 16 g 9-102 Proline 3.7 g Rhamnose 5.3 g Ethanol 16 g 9-10 Glycerine 25 g3 Proline 3.7 g Rhamnose 5.3 g Ethanol 16 g 9-104 Proline 3.7 g Rhamnose 5.3 g Ethanol 16 g 9-10 Glycerine 25 g5 Proline 3.7 g Rhamnose 5.3 g Ethanol 16 g 9-10 Glycerine 50 g6 Proline 3.7 g Rhamnose 5.3 g Ethanol 16 g 9-10 Glycerine 75 g7 Proline 3.7 g Rhamnose 5.3 g Ethanol 16 g 9-10 Glycerine 175 g8 Proline 3.5 g Ribose 4.5 g Ethanol 16 g 9-109 Proline 3.5 g Ribose 4.5 g Ethanol 16 g 9-10 Glycerine 25 g10 Proline 3.5 g Ribose 4.5 g Ethanol 16 g 9-10 Glycerine 50 g11 Proline 3.5 g Ribose 4.5 g Ethanol 16 g 9-10 Glycerine 50 g__________________________________________________________________________ pH ADJ pH ADJ Microwave ColorExperiments Agent Agent Wt. Time Appearance Aroma__________________________________________________________________________1 NaHCO.sub.3 2.7 g 80 sec. White None2 NaHCO.sub.3 2.7 g 40 sec. Burnt Burnt Brown Crusty 20 sec. Golden Bready Brown Sweet3 NaHCO.sub.3 2.7 g 40 sec. White None HOAc 2.2 g 80 sec. White None 120 sec. White None4 NaHCO.sub.3 2.7 g 20 sec. Golden Bready HOAc 2.2 g Brown Sweet5 NaHCO.sub.3 2.7 g 20 sec. Golden Bready Brown Sweet6 NaHCO.sub.3 2.7 g 20 sec. Dark Bready Brown7 NaHCO.sub.3 2.7 g 20 sec. Golden Bready Brown8 NaHCO.sub.3 2.7 g 80 sec. White None9 NaHCO.sub.3 2.7 g 20 sec. Dry Dark Burnt Brown Bready10 NaHCO.sub. 3 2.7 g 20 sec. Dark Brn. Sweet Golden Bready11 NaHCO.sub.3 2.7 g 20 sec. Golden Sweet HOAc 5.0 g Brown Bready__________________________________________________________________________
TABLE V__________________________________________________________________________ Amino Amino Sugar SolventExperiments Acid Acid Wt. Sugar Wt. Solvent Wt. pH__________________________________________________________________________12 Proline 3.5 g Ribose 4.5 g Ethanol 16 g 9-10 Triacetin 25 g13 Proline 3.5 g Ribose 4.5 g Ethanol 16 g 9-10 Propylene Glycol 25 g14 Proline 3.5 g Ribose 4.5 g Ethanol 16 g 9-10 Water 25 g15 Proline 3.5 g Ribose 4.5 g Ethanol 16 g 9-10 Glycerine 25 gColor of Sample Deterioates To Blood Red After 7 Days;EDTA Added Did Not Prevent This16 Proline 3.5 g Ribose 4.5 g Ethanol 16 g 9-10 Glycerine 25 gRepeat of 9; Color Deteriorated To Blood Red In 7 Days.17 Proline 3.5 g Rhamnose 5.5 g Ethanol 16 g 9-10 Glycerine 75 g18 Proline 3.5 g Ribose 4.5 g Ethanol 16 g 9-10 Glycerine 25 gRepeat of 9 Without NaHCO.sub.3 ; Color Remained Yellow After 7 Days.19 Proline 3.5 g Rhamnose 5.5 g Ethanol 16 g 9-10 Glycerine 75 g20 Proline 3.5 g Rhamnose 5.5 g Glycerine 75 g 9-10__________________________________________________________________________ pH ADJ pH ADJ Microwave ColorExperiments Agent Agent Wt. Time Appearance Aroma__________________________________________________________________________12 NaHCO.sub.3 2.7 g 80 sec. White None13 NaHCO.sub.3 2.7 g 20 sec. Yellow Slt Sweet 40 sec. Dk. Yellow Sweet 80 sec. Golden Sweet Bready14 NaHCO.sub.3 2.7 g 20 sec. White None 40 sec. White None 80 sec. White None15 NaHCO.sub.3 2.7 g 20 sec. Same as 9 0.1 gColor of Sample Deterioates To Blood Red After 7 Days;EDTA Added Did Not Prevent This16 NaHCO.sub.3 2.7 g 20 sec. Vry Dark Burnt Brown BreadyRepeat of 9; Color Deteriorated To Blood Red in 7 Days.17 NaHCO.sub.3 2.7 g 20 sec. Drk Brown Burnt Sugar 40 sec. Drk Golden Sweet Brown Hot Buns18 None 20 sec. Yellow Slt Sweet 40 sec. Golden Slt SweetRepeat of 9 Without NaHCO.sub.3 ; Color Remained Yellow After 7 Days.19 NaHCO.sub.3 5.0 g 20 sec. Burnt Burnt Blackened Bread20 NaHCO.sub.3 2.7 g 20 sec. Burnt Burnt Blackened Bread__________________________________________________________________________
TABLE VI__________________________________________________________________________ Amino Amino Sugar SolventExperiments Acid Acid Wt. Sugar Wt. Solvent Wt. pH__________________________________________________________________________21 Alanine 2.7 g Ribose 4.5 g Ethanol 16 g 9-10 Glycerine 25 g22 Alanine 2.7 g Rhamnose 5.5 g Ethanol 16 g 9-10 Glycerine 75 g23 Alanine 2.7 g Cerelose 5.5 g Ethanol 16 g 9-10 Glycerine 25 g24 Lysine 4.4 g Ribose 4.5 g Ethanol 16 g 9-10 Glycerine 25 g25 Lysine 4.4 g Rhamnose 5.5 g Ethanol 16 g 9-10 Glycerine 75 g26 Lysine 4.4 g Cerelose 5.5 g Ethanol 16 g 9-10 Glycerine 25 g27 Proline 3.5 g Cerelose 5.5 g Ethanol 16 g 9-10 Glycerine 25 g28 Proline 3.5 g Fructose 5.5 g Ethanol 16 g 9-10 Glycerine 25 g29 Proline 3.5 g Fructose 5.5 g Ethanol 16 g 9-10 Glycerine 50 g30 Glycine 2.3 Ribose 4.5 g Ethanol 16 g 9-10 Glycerine 25 g31 Glycine 2.3 Rhamnose 5.5 g Ethanol 16 g 9-10 Glycerine 75 g32 Glycine 2.3 Cerelose 5.5 g Ethanol 16 g 9-10 Glycerine 25 g33 Proline 3.5 g Glucose 5.5 g Ethanol 16 g 9-10 Glycerine 25 g__________________________________________________________________________ pH ADJ pH ADJ Microwave ColorExperiments Agent Agent Wt. Time Appearance Aroma__________________________________________________________________________21 NaHCO.sub.3 2.7 g 20 sec. Dark Brn Crusty Burnt22 NaHCO.sub.3 2.7 g 20 sec. Golden Sugary 40 sec. Lite Brn. Sugcookie23 NaHCO.sub.3 2.7 g 20 sec. Lite Brn None 40 sec. Black Burnt Crust24 NaHCO.sub.3 2.7 g 20 sec. Chared Badly Black Burnt25 NaHCO.sub.3 2.7 g 20 sec. Brown Crusty Browner Crusty26 NaHCO.sub.3 2.7 g 20 sec. Chared Good Burnt Crusty27 NaHCO.sub.3 2.7 g 20 sec. Drk Brn Burnt Bread28 NaHCO.sub.3 2.7 g 80 sec. Drk Brn Cooked Pancake29 NaHCO.sub.3 2.7 g 20 sec. Drk Brn Plastic Less Than 2830 NaHCO.sub.3 2.7 g 20 sec. Dark Brn. Sweet Bready31 NaHCO.sub.3 2.7 g 20 sec. Lite Brn Sweet 40 sec. Drk Brn Swt Crust32 NaHCO.sub.3 2.7 g 20 sec. Brown None 40 sec. Brown None33 NaHCO.sub.3 2.7 g 20 sec. Charred Plastic__________________________________________________________________________
TABLE VII__________________________________________________________________________ AMINOEXPERI- AMINO ACID SUGAR SOLVENT pH ADJUSTMENTMENT ACIDS WEIGHT SUGAR WEIGHT SOLVENT WEIGHT pH AGENT__________________________________________________________________________34 PHENYL RIBOSE 4.5 g ETHANOL 16 g 9-10 NaHCO.sub.3 ALANINE 5.0 g GLYCERINE 25 g (MW84) (MW 131.2) LEUCINE 4.0 g (MW 165.2)35 PHENYL RHAMNOSE 5.5 g ETHANOL 16 g 9-10 NaHCO.sub.3 ALANINE 5.0 g GLYCERINE 75 g LEUCINE 4.0 g36 PHENYL RHAMNOSE 5.5 g ETHANOL 16 g 9-10 NaHCO.sub.3 ALANINE 5.0 g GLYCERINE 25 g LEUCINE 4.0 g37 PHENYL RHAMNOSE 5.5 g ETHANOL 16 g 9-10 NaHCO.sub.3 ALANINE 5.0 g GLYCERINE 75 g LEUCINE 4.0 g38 PHENYL CERELOSE 5.5 g ETHANOL 16 g 9-10 NaHCO.sub.3 ALANINE 5.0 g GLYCERINE 25 g LEUCINE 4.0 g39 PHENYL CERELOSE 5.5 g ETHANOL 16 g 9-10 NaHCO.sub.3 ALANINE 5.0 g GLYCERINE 75 g LEUCINE 4.0 g40 PHENYL CERELOSE 11.0 g ETHANOL 16 g 9-10 NaHCO.sub.3 ALANINE 5.0 g GLYCERINE 75 g LEUCINE 4.0 g__________________________________________________________________________ EXPERI- pH ADJUSTMENT MICROWAVE COLOR MENT AGENT WEIGHT TIME APPEARANCE AROMA__________________________________________________________________________ 34 2.7 g 20 sec. TAN MALTY BURNT COCOA 35 2.7 g 20 sec. YELLOW FAINT CHOCOLATE 40 sec. LIGHT BROWN FAINT CHOCOLATE 36 5.4 g 20 sec. LIGHT BROWN CHOCOLATE 40 sec. BROWN CHOCOLATE 37 4.5 g 20 sec. BROWN CHOCOLATE 40 sec. DARK BROWN DARK COCOA 38 5.4 g 20 sec. LIGHT YELLOW NONE 40 sec. LIGHT BROWN FAINT CHOCOLATE 60 sec. NO CHANGE 39 5.4 g 20 sec. BROWN YELLOW NONE 40 sec. BROWN CHOCOLATE 60 sec. DARK BROWN DARK CHOCOLATE 40 5.4 g 20 sec. NONE NONE 40 sec. TAN FAINT CHOCOLATE 60 sec. LIGHT BROWN MILK__________________________________________________________________________ CHOCOLATE
TABLE VIII__________________________________________________________________________ AMINOEXPERI- AMINO ACID SUGAR SOLVENT pH ADJUSTMENTMENT ACIDS WEIGHT SUGAR WEIGHT SOLVENT WEIGHT pH AGENT__________________________________________________________________________41 PHENYL RIBOSE 4.5 g ETHANOL 16 g 9-10 NaHCO.sub.3 ALANINE 5.0 g (MW84) (MW 131.2) LEUCINE 4.0 g (MW 165.2)42 PHENYL RHAMNOSE 5.5 g ETHANOL 16 g 9-10 NaHCO.sub.3 ALANINE 5.0 g LEUCINE 4.0 g43 PHENYL RHAMNOSE 5.5 g ETHANOL 16 g 9-10 NaHCO.sub.3 ALANINE 5.0 g LEUCINE 4.0 g44 PHENYL RHAMNOSE 5.5 g ETHANOL 16 g 9-10 NaHCO.sub.3 ALANINE 5.0 g LEUCINE 4.0 g45 PHENYL CERELOSE 5.5 g ETHANOL 16 g 9-10 NaHCO.sub.3 ALANINE 5.0 g LEUCINE 4.0 g46 PHENYL CERELOSE 5.5 g ETHANOL 16 g 9-10 NaHCO.sub.3 ALANINE 5.0 g LEUCINE 4.0 g47 PHENYL CERELOSE 11.0 g ETHANOL 16 g 9-10 NaHCO.sub.3 ALANINE 5.0 g LEUCINE 4.0 g__________________________________________________________________________ EXPERI- pH ADJUSTMENT MICROWAVE COLOR MENT AGENT WEIGHT TIME APPEARANCE AROMA__________________________________________________________________________ 41 2.7 g 20 sec. White None White None 42 2.7 g 20 sec. White None 40 sec. White None 43 5.4 g 20 sec. White None 40 sec. White None 44 4.5 g 20 sec. White None 40 sec. White None 45 5.4 g 20 sec. White None 40 sec. White None 60 sec. White None 46 5.4 g 20 sec. White None 40 sec. White None 60 sec. White None 47 5.4 g 20 sec. White None 40 sec. White None 60 sec. White None__________________________________________________________________________
TABLE IX__________________________________________________________________________ AMINOEXPERI- AMINO ACID SUGAR SOLVENT pH ADJUSTMENTMENT ACIDS WEIGHT SUGAR WEIGHT SOLVENT WEIGHT pH AGENT__________________________________________________________________________48 PHENYL RIBOSE 4.5 g Propylene 40 g 9-10 NaHCO.sub.3 ALANINE 5.0 g Glycol (MW84) (MW 131.2) LEUCINE 4.0 g (MW 165.2)49 PHENYL RHAMNOSE 5.5 g Propylene 16 g 9-10 NaHCO.sub.3 ALANINE 5.0 g Glycol LEUCINE 4.0 g Glycerine 75 g50 PHENYL RHAMNOSE 5.5 g Propylene 16 g 9-10 NaHCO.sub.3 ALANINE 5.0 g Glycol LEUCINE 4.0 g Glycerine 25 g51 PHENYL RHAMNOSE 5.5 g Propylene 40 g 9-10 NaHCO.sub.3 ALANINE 5.0 g Glycol LEUCINE 4.0 g52 PHENYL CERELOSE 5.5 g Propylene 16 g 9-10 NaHCO.sub.3 ALANINE 5.0 g Glycol LEUCINE 4.0 g Glycerine 25 g53 PHENYL CERELOSE 5.5 g Propylene 40 g 9-10 NaHCO.sub.3 ALANINE 5.0 g Glycol LEUCINE 4.0 g54 PHENYL CERELOSE 11.0 g Propylene 40 g 9-10 NaHCO.sub.3 ALANINE 5.0 g Glycol LEUCINE 4.0 g__________________________________________________________________________ EXPERI- pH ADJUSTMENT MICROWAVE COLOR MENT AGENT WEIGHT TIME APPEARANCE AROMA__________________________________________________________________________ 48 2.7 g 20 sec. TAN MALTY BURNT COCOA 49 2.7 g 20 sec. YELLOW FAINT CHOCOLATE 40 sec. LIGHT BROWN FAINT CHOCOLATE 50 5.4 g 20 sec. LIGHT BROWN CHOCOLATE 40 sec. BROWN CHOCOLATE 51 4.5 g 20 sec. BROWN CHOCOLATE 40 sec. DARK BROWN DARK COCOA 52 5.4 g 20 sec. LIGHT YELLOW NONE 40 sec. LIGHT BROWN FAINT CHOCOLATE 60 sec. NO CHANGE 53 5.4 g 20 sec. BROWN YELLOW NONE 40 sec. BROWN CHOCOLATE 60 sec. DARK BROWN DARK CHOCOLATE 54 5.4 g 20 sec. NONE NONE 40 sec. TAN FAINT CHOCOLATE 60 sec. LIGHT BROWN MILK__________________________________________________________________________ CHOCOLATE
A comparison of Experiments 1-33, 34-40, 41-47 and 48-54 shows that it is critical that:
(a) the solvent used be either:
a mixture of ethanol and glycerine; or
a mixture of propylene glycol and glycerine as opposed to ethanol alone; and
(b) the sugar reactant used must be ribose, rhamnose or cerelose (as opposed to fructose or glucose) (see Experiments 29 and 33).
EXAMPLE VII
Preparation of a Cocoa Beverage
In a 2 liter reaction vessesl equipped with stirrer, thermometer, heating mantle, reflux condenser and addition funnel is placed the following ingredients:
______________________________________Ingredients Parts by Weight______________________________________Phenyalanine 50.0 gramsLeucine 40.0 gramsEthyl alcohol 160.0 gramsGlycerine 750.0 gramsSodium bicarbonate 54.0 gramsRhamnose 55.0 grams______________________________________
The reaction mass is stirred at 40° C. for a period of one hour until most of the ingredients are dissolved. The resulting reaction mass is placed into a vessel which is placed in an industrial microwave oven. The reaction mass with stirring is microwaved until brown (total time 30 seconds).
The microwave radiation source is an Industrial Amana microwave oven (trademark of the Amana Corporation).
The resulting product is used in the production of a chocolate flavored beverage and a chocolate pudding as follows:
EXAMPLE VII(A)
Preparation of Cocoa Beverage
In a sauce pan, one cup of cocoa is blended with one cup of granulated sugar, three quarters teaspoon of salt and 1.5 quarts of water. With stirring the resulting product is boiled for a period of 10 minutes. At the end of the 10 minute period, 10 grams of the above flavor material is added to the cocoa mixture. Meanwhile, milk (4 quarts) is scalded in a double boiler. The resulting milk product is stirred into the cocoa mixture. The cocoa mixture is permitted to remain at low heat for 0.5 hours. One tablespoon of vanilla extract is admixed with 40 grams of the above microwaved flavor. The resulting mixture is added to the beverage with stirring. The resulting product has a natural, intense cocoa flavor having a quality on a scale of 1-10 of 9 and an intensity on a scale of 1-10 of 9 compared to the beverage without the microwaved flavor of my invention which has a quality on a scale of 1-10 of 6 and an intensity on a scale of 1-10 of 5 (as judged by five members of an "expert" panel).
EXAMPLE VII(B)
Preparation of a Chocolate-Cream Bread
7.5 Cups of milk is heated with 6 squares of unsweetened natural chocolate and one teaspoon of salt over low heat until the chocolate is melted; and then blended in a blender at 85 rpm for a period of 8 minutes.
Four whole eggs and two egg yolks are stirred for a period of 5 minutes at 70 rpm; and 1.5 cups of sucrose is added to the blend and the blending is continued at the same rate for a period of 5 minutes. The melted chocolate mixture is then blended in with the resulting product at 85 rpm.
40 Grams of the above-microwaved flavor is added to the resulting blend.
The resulting chocolate mixture is placed in a 3 quart cassarole and is baked for one hour.
Two egg whites are beatened until foamy and then 0.25 cups of sugar is gradually added until it is blended in at 150 rpm.
The resulting product is blended into the resulting chocolate mix for a period of 5 minutes and then baked for a period of 10 minutes at 400° F.
The resulting product is chilled to 30° F for a period of two hours.
The resulting pudding has an intense, natural chocolate aroma and taste and relatively high intensity; the quality and intensity on a scale of 1-10 being judged to be "9". The same chocolate pudding without the above-mentioned microwave flavor has a quality on a scale of 1-10 of 7 and an intensity on a scale of 1-10 (with respect to the chocolate flavor) of 4 (as judged by a 5 member expert panel).
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Described is a process for carrying out microwave production of a chocolate flavoring product, the product produced thereby and foodstuffs, beverages and chewing gums containing said product. The process comprises the steps of:
(a) providing a composition of matter consisting essentially of precursors of a chocolate flavor (e.g., sugar, leucine and phenyl alanine) and a solvent capable of raising the dielectric constant of the reaction mass to be heated;
(b) exposing the mixture of reaction precursors to microwave radiation for a period of time so that the resulting product is caused to have a chocolate flavor;
(c) providing a foodstuff, chewing gum or beverage base;
(d) admixing the chocolate flavor reaction product of (b) with the foodstuff, beverage or chewing gum base.
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FIELD OF THE INVENTION
The present invention relates to treadmills, and more particularly, to treadmills of the passive type, typically employed for exercise purposes and including a flywheel and a governor having axially adjustable, flexible rotating blades axially movable by an adjustment cam and cooperating with a stationary surface for limiting the linear velocity of the treadmill belt which engages the roller coupled to the flexible blades of the governor, and further including method and apparatus for assembling the treadmill rollers along support rails in a simiplified manner, said method assuring precise horizontal and vertical alignment of the roller shafts.
BACKGROUND OF THE INVENTION
Treadmills are presently utilized as advantageous means for performing vigorous exercise indoors and at a stationary position. Such treadmills are typically comprised of an elongated closed-loop belt supported by a plurality of rotatable rollers arranged at closely-spaced parallel intervals and being mounted in a freewheeling manner. In order to limit the linear speed of the belt, it is typical to provide a flywheel. The user holds on to the treadmill rail to control speed. Only one known treadmill employs a governor which is both complicated and expensive. It is, therefore, desirable to provide a governor for treadmills and the like which is simple to use and having a simplified and yet rugged and reliable design to enable rapid adjustment of the treadmill linear speed.
DESCRIPTION OF THE INVENTION
The present invention provides a treadmill assembly which is characterized by a novel governor having rotatable flexible blades adjustably moveable in the axial direction about the center of rotation and having brake pads at the free end of the blades for slidable engagement with a cooperating stationary annular surface. The blades are mounted upon a shaft normally urging the blades away from the stationary annular surface. Cam means is provided to adjust the axial position of said flexible blades relative to said stationary surface. The centrifugal force developed by the rotating blades cause the blade ends to deflect toward the stationary surface, the amount of deflection being a function of the magnitude of the centrifugal force. The cam means thus serves as a means for limiting the linear speed of the treadmill in a simple and straightforward manner.
The treadmill belt is supported by a plurality of rollers arranged at closely-spaced, parallel intervals, said rollers being supported by a pair of rails each provided with a roller supporting section having an elongated opening communicating with a plurality of slots open ended at their bottom ends for receiving the roller shafts. The roller shafts are maintained at the proper height and are retained within said slots by means of an elongated rod inserted into said elongated opening and arranged beneath said roller shafts. An elongated resilient member is arranged in each of said elongated openings to compensate for any dimension deviations due to normal tolerances, and thereby prevent the roller shafts from experiencing any linear movement.
OBJECTS OF THE INVENTION AND BRIEF DESCRIPTION OF THE FIGURES
It is, therefore, one object of the present invention to provide a novel governor for use in treadmill assemblies and the like, said governor employing axially positionable flexible rotating blades adapted to experience substantially linear movement in a direction parallel to the rotational axis of the blades and further including adjustable cam means for controlling the position of said blades along their longitudinal axis to adjust the position of the brake pads carried by the blades relative to a cooperating stationary annular surface, and thereby control and limit the linear speed of the treadmill.
Still another object of the present invention is to provide a governor for treadmill assemblies and the like, which is of simple, compact design thereby providing a compact governor assembly capable of being arranged within a small housing.
Still another object of the present invention is to provide a treadmill assembly incorporating a plurality of closely-spaced rollers supported by the roller support sections of a pair of rails, each rail support section having an elongated opening and a plurality of slots communicating with said opening each receiving one of the roller shafts and including an elongated rod extending through each of said elongated openings for supporting the shafts of said rollers extending into said opening, and for retaining said shafts in said rail.
Still another object of the present invention is to provide a treadmill assembly of the character described in which rope-like resilient compressible means is arranged in each of said elongated openings above said roller shafts to restrain the roller shafts from experiencing any undesirable linear displacement.
The above as well as other objects of the present invention will become apparent when reading the accompanying description and drawings in which:
FIG. 1 shows a perspective view of a treadmill assembly designed in accordance with the principles of the present invention.
FIG. 2 shows a broken top plan view of the treadmill assembly of FIG. 1, in which portions thereof are sectionalized for facilitating the understanding of the present invention.
FIGS. 3a and 3b show plan and side elevations respectively, of a spider employed in the governor assembly of FIG. 2.
FIG. 4 is an end view of a brake disc employed in the governor of FIG. 2.
FIG. 5 is a plan view of one of the flexible resilient springs of the governor shown in FIG. 2.
FIG. 6 is an exploded perspective view showing the brake pad and spacer assembly of FIG. 2 in greater detail.
FIG. 7 is a partially exploded perspective view showing the shaft sub-assembly of the governor assembly of FIG. 2 in greater detail.
FIGS. 8a and 8b show plan and end views respectively, of the cam assembly employed in the governor assembly of FIG. 2.
FIG. 9 shows a perspective view of the cam and lever assembly employed in the governor assembly of FIG. 2.
FIG. 10 shows a top plan view of the frame assembly employed in the treadmill assembly of FIG. 2.
FIGS. 10a and 10b show end and side views of the frame as shown in FIG. 10.
FIGS. 11a, 11b and 11c show sectional views taken along the lines 11a--11a, 11b--11b and 11c--11c of FIG. 10b.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a treadmill 10 embodying the principles of the present invention and comprised of a treadmill belt 12 arranged between a pair of rails 14 and 16, shown best in FIGS. 10-10b. The left-hand ends of rails 14 and 16 are designed to rest upon a floor or other suitable supporting surface.
A plurality of rollers 18 (see FIG. 2) are arranged between rails 14 and 16, and have their shafts 18a, as shown in FIGS. 2, 10b and 11a, extending into openings 14a, 16a provided at spaced intervals along each of the confronting inner surfaces of the roller supporting sections of rails 14 and 16. FIG. 10b shows one set of openings 14a arranged at spaced intervals along the roller supporting section 122 of rail 14.
U-shaped bar or handle assembly 20 of treadmill 10 is comprised of a yoke portion 20a for gripping by a treadmill user, if desired. Downwardly depending arms 20b and 20c terminate in feet covered with rubber-like supporting cups 22, 22. The arms 20b and 20c extend through openings 14e, 16e in rails 14 and 16, and are secured thereto by suitable fastening means (see FIGS. 1 and 10).
As shown in FIG. 2, continuous closed loop treadmill belt 12, in addition to encircling rollers 18, encircles a forward-most roller comprised of hollow cylindrical member 22, whose left-hand end receives the right-hand end 24a of a support member 24, the end 24a being force-fitted into the left-hand end of hollow cylinder 22. Intermediate portion 24b of member 24 is journaled within bearing assembly 26, while the left-hand end 24c of member 24 extends through the central opening 28a in flywheel 28. Washer 30 and fastener 32 secure flywheel 28 to member 24, and hence to roller 22. The bearing 26 is mounted within an opening 27a in support member 27, joined to rail 14 by fastener 29.
The right-hand end of hollow cylindrical member 22 force-fittingly receives the left-hand end of hollow shaft supporting member 34, whose right-hand end 34a is journaled within bearing assembly 36, which is arranged within opening 46e in governor base plate 46 (see FIGS. 2 and 4). Member 34 (note FIG. 7) has a hexagonal-shaped bore of a cross-sectional configuration adapted to conform to and slidably receive elongated hexagonal shaft 38. A closure cap 40 closes and seals the left-hand end of the hexagonal-shaped opening in member 34. Helical spring 42 is positioned between cap 40 and the left-hand end of hexagonal shaft 38. Shaft 38 is slidable within member 34, and is normally urged to the right by spring 42. The right-hand end of shaft 38 extends into governor assembly 44 comprised of generally circular-shaped base plate 46, which is joined to rail 16 by fasteners 48, 48 extending through openings 46d in base plate 46 (see FIG. 4).
A retaining ring 50 is secured within an annular groove 38c in shaft 38 intermediate its ends and is engaged by ring-shaped member 51, which engages a first flexible blade 52, having a central portion 52a provided with a hexagonal-shaped central opening 52b (see FIG. 5). Flexible blade 52 is bent along bend lines 52c and 52d to form the diagonally-aligned portions 52e and 52f, and is further bent along bend lines 52g and 52h forming radially aligned free end portions 52i and 52j, each having an opening 52k and 52l, respectively. A spacer 54 having a generally cylindrical outer surface and a hexagonal-shaped hollow interior, is placed over shaft 38 and provides the desired spacing between flexible blade 52 and flexible blade 52', which is substantially identical to blade 52. A circular-shaped disk 57 having a hexagonal-shaped recess 57a is placed against and receives the right-hand end of shaft 38. The marginal portion of disk 57 rests against blade 52' and is positioned between the right-hand surface of the central portion 52a' of blade 52' and ring-shaped washer 56, and is retained in place by hexagonal-shaped nut 58, having a threaded portion 58a, which threadedly engages a threaded member 59 which also engages the tapped interior portion 38b of shaft 38. An elongated button-like cylindrical-shaped member 60 having a low friction bearing surface is force-fitted into the opening in the right-hand end of nut 58 and its rounded tip is arranged to slidably engage the diagonally-aligned cam surface 64 of a pivotally mounted cam member 62 shown in FIGS. 2, 8a, 8b and 9. The diagonally-aligned cam surface 64 adjustably controls the position occupied by button 62, which in turn determines the position of shaft 38, which is moved either toward the left or toward the right, relative to the position occupied by cam member 62, thereby movably positioning flexible blades 52, 52'.
The free ends 52i, 52i' of blades 52, 52', shown best in FIGS. 2, 5 and 6, receive and support a brake assembly comprised of a cylindrical disk 64 serving as a spacer arranged between blade portions 52i, 52i', a second circular disk 66 arranged against the right-hand surface of blade portion 52i and a third circular disk 68 arranged against the left-hand surface of blade portion 52i'.
Circular disk 68 is provided with a recess 68a having a central opening 68b, which tapers to a narrower clearance opening 68c, which extends through the right-hand side of disk 68. Disks 64 and 66 each have threaded central openings 64a, 66a for receiving and threadedly engaging threaded fastener 70 to secure the brake assembly comprised of blade ends 52i, 52i' and disks 64, 66 and 68. The threaded fastening member 70 has a head portion with a tapered configuration 70a, which is received within the tapered portion provided in disk 68 between openings 68b and 68c. Thus the top surface 70b of fastener 70 is substantially flush with the recessed surface 68a of disk 68.
A brake pad in the form of a circular disk 72 is positioned within recess 68a and is preferably adhesively secured therein. It should be noted in FIG. 2 that a pair of brake pad assemblies 74, 74' are provided at each end of the pair of flexible blades. The brake pads 72, 72' are positioned to selectively engage an annular surface 46a provided inwardly of the periphery of governor base plate 46. The brake pads are preferably formed of felt.
The governor assembly 44 is covered by a spider 78, shown best in FIGS. 2, 3a and 3b, which spider is comprised of a cylindrical disk 80 having three L-shaped legs 82, 84, 86, the short leg portions 82a, 84a and 86a being joined to the interior surface of the disk 80, for example, by welding, and the long leg portions 82b, 84b and 86b extending away from disk 80 and toward governor base plate 46. Each of the legs 82-86 is provided with an opening 82c, 84c, 86c at its free end, each of said openings receiving a fastening member 88, which threadedly engages tapped openings, such as for example, tapped openings 46b, 46c in base plate 46, for securing spider 80 to base plate 46. Opening 80a in disk 80 receives shaft 96, which supports cam member 62 (see FIG. 9), and opening 80b supports guide member 108 (see FIG. 2).
A gasket 90 encircles the periphery of disk 80 and is provided with a continuous groove 90a for embracing the peripheral edge of disk 80 (see FIG. 2). An elongated flexible sheet is arranged to rest upon a first shoulder 90b provided in gasket 90, and a second shoulder 46d arranged about the periphery of base plate 46. Sheet 92 encircles and encloses the governor assembly 44.
The adjustable cam 62 is provided with a mounting opening 62b at the end of arm 62a, shown best in FIGS. 2, 8a and 9. Shaft 96 is force-fitted into opening 62b in cam member 62 and has its opposite end extending into opening 98a in lever arm 98. The left end of shaft 96 is provided with a flat 96a for engagement by a set screw 100, which threadedly engages tapped opening 98b in lever arm 98, which tapped opening communicates with opening 98a in order to secure shaft 96 to lever arm 98. As was mentioned above, shaft 96 extends through opening 80a in disk 80 (see FIG. 3a).
The left-hand end of lever arm 98 is provided with a pair of bifurcated arms 98c, 98d defined by a slot 98e arranged therebetween. An opening is provided in each of the arms 98c, 98d for receiving pin 102, which extends through these openings, as well as an opening 104a in a cable anchor 104, whose upper end 104a is secured to one end of a cable 106. Cable 106 extends through an opening 108a in post 108 secured to spider disk 80 by fastening member 108b. The cable extends upwardly along arm 20b of U-shaped handle assembly 20, shown in FIG. 1, and has its upper end 106b secured to the anchoring end 110a of handle 110, which is pivotally mounted to arm 20b by pin 112. By swinging handle 110, cable 106 is moved respectively up or down, causing the movement of lever arm 98, which extends through opening 80a in spider cylindrical disk 80, as shown best in FIG. 2, in order to rotate lever arm 98 and cam 62.
The position of rotatable cam 62 controls the positioning of button 60 and hence flexible arms 52, 52' and brake shoes 72, 72' relative to the cooperating stationary surface 46a.
The governor 44 assembly operates as follows:
A person standing upon the treadmill belt 12 may either walk or run in the "uphill" direction, i.e., in a direction from the left toward the right, relative to FIG. 1, causing the upper run 12a of treadmill belt 12 to move in the direction shown by arrow 114. The treadmill belt engages hollow cylindrical roller 22, causing it to rotate. Member 34 and hexagonal shaft 38 rotate together with hollow cylindrical roller 22, causing the rotation of flexible blades 52, 52'. The flexible blades 52, 52' develop a centrifugal force, the magnitude of which controls the deflection of the diagonal portions 52e, 52e', 52f, 52f' of the flexible blades 52e, 52e' l towards the left, the greater the angular velocity, the greater the deflection. As the angular velocity and hence the amount of deflection increases, the brake pads 72, 72', mounted to the ends of blades 52, 52' engage stationary annular surface 46a to limit the angular velocity of roller 22 and hence treadmill belt 12. By adjusting cam member 62 to move shaft 38 further toward the right, the drag imposed upon treadmill belt 12 by the governor assembly 44 is reduced or even removed, allowing the treadmill to move at a faster rate. Conversely, by moving cam member 62 to move shaft 38 further toward the left and against the force of spring 42, the maximum speed of treadmill belt 12 is decreased.
Due to the unique shape of the flexible blades 52, 52', the outward radial movement of the brake assemblies 74, 74' is minimal, providing a governor assembly of small, compact size, most of the movement of the brake assembly 74, 74' occurring in a direction substantially parallel to the axis of rotation of the blades.
The housing of the governor assembly is arranged to be easily and readily removed and replaced to simplify the periodic removal and replacement of the brake pads 72, 72'.
As was mentioned hereinabove, treadmill belt 12 is supported by a plurality of closely-spaced rollers 18. Each roller 18 is mounted upon a shaft 18a, the free ends of which extend outwardly from the free ends of the roller 18. The rails 14 and 16 are provided with an intermediate portion 120, shown best in FIGS. 10b and 11a-11c, said intermediate portion having an elongated hollow rectangular-shaped roller shaft supporting section 122, extending inwardly from each rail, such as for example, the rail 14 shown in FIGS. 11a-11c. The hollow-shaped shaft supporting section 122 is provided with an elongated substantially rectangular-shaped hollow interior 124. In order to mount the shafts 18a of rollers 18, slots 14a are machined into the inwardly extending projection 122 at regular intervals, as shown in FIG. 10b. The slots 14a are open at their bottom ends.
At least one end of the hollow interior 124 provided in hollow shaft supporting section projection 122 is open.
Once the slots 14a are machined or otherwise formed in shaft supporting section 122, one end of the shafts 18a are each inserted upwardly into one of the slots 14a to be arranged in the manner shown in FIGS. 10b and 11a. The shafts 18a are lifted upwardly to rest against the upper end 14a-1 of each slot 14a and an elongated rod 126, preferably having a rectangular-shaped cross-section, is inserted through the open right-hand end of section 122 and into hollow elongated interior 124. The rollers 18 and shafts 18a are lifted, in order to pass rod 124 beneath each of the shafts 18a, so that the rod 126 supports all of the shafts 18a at a uniform height.
An elongated resilient compressible rope-like member 130 is preferably initially inserted into hollow elongated opening 124, in order to be positioned between rollers 18a and the interior top surface 132 of elongated opening 134. The diameter of rope-like member 130 is preferably greater than the distance between top interior wall 132 and engaging portion of roller shaft 18a to provide a tight fit of shaft 18a within slot 14a, and to prevent any "play" between shafts 18a, rod 126 and shaft supporting section 122.
Rod 124 supports all of the rollers 18a at a proper uniform height, while rope-like member 130 compensates for any play between the shaft 18a, the upper end of each slot 14b and elongated rod 126. Elongated rod 126 serves the dual function of supporting all of the roller shafts at the proper uniform height and of retaining all of the shafts 18a in their operating position without the need for any fastening means whatsoever. It should be understood that the mounting arrangement provided in rail 16 is identical to that described in connection with rail 14. Preferably rope-like member 130 is placed within hollow interior 124 prior to insertion of the shafts 18a into slots 14a.
The rails 14 and 16 are preferably formed through an extrusion process, thus further significantly reducing the cost of components as well as reducing the fabrication and assembly costs.
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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A passive treadmill having a governor to adjustably limit the rate of speed of the treadmill belt. Resilient flexible rotating blades flex due to the centrifugal force developed during rotation, the magnitude of the centrifugal force being a function of the linear speed of the treadmill belt. Brake pads mounted on the flexible blades move into sliding engagement with an annular stationary surface to limit the linear speed of the treadmill belt. A rotatably mounted cam is manually adjustable to adjust the spacing between the aforesaid slidably engagable surfaces to adjust the governor. The governor assembly is of relatively small size and volume and the moving components of the governor are mounted within a compact casing.
The rollers, which rollingly support the treadmill belt, are rotatably mounted within elongated openings provided in each of a pair of mounting rails. Roller support shafts are inserted into slots arranged at spaced intervals along the support rails and a compressible rope is arranged between the support shafts and the upper interior surface of the support rail elongated openings. A single elongated rod in the elongated opening of each rail supports all of the associated shafts, providing the dual functions of securing said roller shafts in position and rotatably supporting all of the roller shafts at a uniform height. The compressible rope compensates for any tolerances between the parts and prevents the roller shafts, and hence the rollers, from experiencing any undesirable movement and/or vibration.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a divisional of pending U.S. application Ser. No. 12/956,352, entitled “NON-RIGID SENSOR FOR DETECTING DEFORMATION”, filed Nov. 30, 2010, having attorney Docket No. HALC.155446.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
BRIEF SUMMARY OF THE INVENTION
[0003] The present invention relates to a “soft” electrical sensor. More particularly, this invention relates to a flexible and compressible sensor that can be incorporated into compressible items where a rigid sensor would be undesirable. The sensor can not only detect compression of the sensor, but can also detect varying degrees of compression, thereby permit responsive actions related to the degree of compression.
[0004] Numerous types of plush toys (e.g., teddy bears) and items with electronics therein are known in the art. Generally, however, the mechanical and electrical components inside the plush are perceptible by the user of the plush upon squeezing the plush, as they are generally a hard, rigid material, such as plastic and/or metal. This is in contrast to the overall purpose of the plush in the first place, i.e., to be soft.
[0005] The method and apparatus of the present invention overcomes these and other drawbacks by providing an electrical component which is soft, squeezable, and resilient. In one embodiment a soft sensor is designed for use in a plush toy to identify interaction and even degrees of interaction with the plush toy by a user. As a holder of the plush toy gently squeezes the plush, the sensor initially identifies a first level of compression and thereby identifies it with a gentle hug, at which point the plush may respond with an appropriate audible response. As the holder of the plush squeezes the plush harder, the sensor identifies a greater level of compression associated with a stronger hug and provides for playback of an alternate appropriate audible response.
[0006] In one embodiment, the sensor may include a pair of conductive foam sheets separated by a non-conductive foam sheet. The non-conductive foam sheet has one or more holes therethrough. As such, the conductive foam sheets are space apart by the non-conductive foam sheet, but the two outer conductive foam sheets may be made to connect in the holes by compressing the two outer sheets together.
[0007] Further objects, features and advantages of the present invention over the prior art will become apparent from the detailed description of the drawings which follows, when considered with the attached figures.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0008] The features of the invention noted above are explained in more detail with reference to the embodiments illustrated in the attached drawing figures, in which like reference numerals denote like elements, in which FIGS. 1-16 illustrate several possible embodiments of the present invention, and in which:
[0009] FIG. 1 is a front side elevation view of a plush toy having a sensor constructed in accordance with an embodiment of the present invention positioned therein in a use environment;
[0010] FIG. 2 is a front side elevation view of the plush toy of FIG. 1 ;
[0011] FIG. 3 is an illustration similar to FIG. 2 , but with portions of the plush toy cut away to reveal an embodiment of the sensor of the present invention and electrical components therein;
[0012] FIG. 4 is an illustration similar to FIG. 3 , but with an alternate arrangement of the electrical component connections;
[0013] FIG. 5 is a left side elevation view of the plush of FIG. 2 in a rest position and with a portion thereof cut away to illustrate the sensor in a rest position;
[0014] FIG. 6 is an illustration similar to FIG. 5 , but with the plush and the sensor in a compressed position;
[0015] FIG. 7 is a perspective view of a first embodiment of the sensor of the present invention with a portion of an enclosure cut away for clarity;
[0016] FIG. 8 is a side elevation view of the sensor of FIG. 7 ;
[0017] FIG. 9 is a cross-sectional view taken along the line 9 - 9 of FIG. 7 ;
[0018] FIG. 10 is a view similar to FIG. 9 , but with the sensor in a compressed position;
[0019] FIG. 11 is an enlarged, fragmentary view of the sensor of FIG. 10 in the area 11 ;
[0020] FIG. 12 is an exploded, perspective view of the sensor of FIG. 7 ;
[0021] FIG. 13 is a perspective view of a second embodiment of the sensor of the present invention with a portion of an enclosure cut away for clarity;
[0022] FIG. 14 is side elevation view of the sensor of FIG. 13 ;
[0023] FIG. 15 is a cross-sectional view taken along the line 15 - 15 of FIG. 13 ; and
[0024] FIG. 16 is an exploded perspective view of the sensor of FIG. 13 .
DETAILED DESCRIPTION OF THE INVENTION
[0025] Referring now to the drawings in more detail and initially to FIG. 1 , numeral 10 generally designates a plush item or toy, such as a teddy bear. The plush 10 may be of any configuration or shape, but generally includes a soft fabric outer layer 12 and is generally filled with some type of soft compressible fill material 14 . This well-known combination creates a plush item 10 that children 16 like to hold and/or squeeze, as pictured in FIG. 1 .
[0026] This particular plush 10 includes electrical components 18 that allow the plush 10 to interact with the child 16 . The electrical components 18 generally include a battery 20 , a micro-processor 22 , a speaker 24 , a plush hug sensor 26 of the present invention, and a plurality of the wires 28 connecting all of the other electrical components 18 to make an electrical circuit 30 .
[0027] The battery 20 can be any power source known in the art. When the plush hug sensor 20 is positioned inside a plush item 10 , the power source is preferably a self-contained device, such as the battery 20 . The battery 20 , as is known in the art, is preferably contained inside a battery compartment or housing 32 . As the battery housing 32 is generally necessarily a rigid structure, and an item which users occasionally need access to in order to replace the battery 20 , the battery housing is preferably positioned adjacent the outer layer 12 . Additionally, as children 16 generally hug the torso or trunk 34 of the plush item, rigid or non-soft items are preferably positioned above or below the middle 34 of the plush toy 10 . In the embodiments illustrated in FIGS. 3-6 , the battery compartment 32 is positioned inside a pocket 36 which is accessed through a rear 38 of the plush 10 near a lower most portion 40 of the trunk 34 . It should be noted that the battery compartment 32 can be positioned anywhere within the plush toy 10 .
[0028] Similarly, the speaker 24 may be positioned within a rigid housing 42 to protect it from damage. In the illustrated embodiments, the speaker housing 42 is positioned in a head 44 of the plush 10 adjacent or directly behind where the animal figure's mouth would be such that audio emanating from the speaker 24 appears to be spoken by the plush 10 or emanating from its mouth.
[0029] The microprocessor 22 , to be protected from damage, may be positioned in either the battery compartment 32 or the speaker housing 42 . FIG. 3 illustrates an embodiment where the microprocessor 22 is positioned in the speaker housing 42 and FIG. 4 illustrates an embodiment where the microprocessor 22 is positioned in the battery compartment 32 .
[0030] The sensor 26 , which has been identified as a plush hug sensor for reasons that will become apparent after the benefit of this full disclosure but which is not constrained for use in a plush or for detecting hugs, is preferably constructed as a multi-layer device. In a first embodiment illustrated in FIGS. 7-12 , the sensor 26 preferably includes a pair of conductive foam sheets 46 , 48 separated by a non-conductive foam sheet 50 . While the sensor may be made with only the three layers of foam, preferably, adhesive layers 52 and 54 are positioned intermediate the foam layers to secure the foam layers to one another and to maintain the structural integrity of the sensor 26 , as will be discussed in more detail below.
[0031] The non-conductive foam 50 , which is intermediate the two outer foam layers 46 , 48 , includes one or more holes or apertures 56 therethrough, as best illustrated in FIGS. 9 and 12 . While the intermediate, non-conductive foam layer 50 spaces apart the two conductive foam layers 46 , 48 , the holes 56 through the non-conductive foam 50 provide an opening through the non-conductive layer 50 where inwardly facing surfaces 58 of the conductive layers 46 , 48 can connect in abutting contact when moved towards one another. In that regard, the sensor 26 has a normal rest or non-compressed position that is illustrated in FIGS. 5 and 7 - 9 . In this position, as best illustrated in FIG. 9 , the inwardly facing surfaces 58 of the outer conductive layers 46 , 48 are spaced apart from one another and do not provide an electrical connection from one layer to another or across the sensor 26 . In this regard, the sensor 26 , in this state, essentially acts as an open switch to prevent the flow of current across the sensor 26 and through the circuit 30 .
[0032] Because the sensor 26 is compressible (or at least because the two conductive layers 46 , 48 are moveable towards one another), external forces on the sensor 26 , preferably from opposite sides of the sensor 26 in the form of compression forces, will act to compress the non-conductive foam layer 50 and move the inwardly facing surfaces 58 of the two conductive layers 46 , 48 towards one another until they are in abutting contact in the areas where the non-conductive foam layer 50 has apertures 56 , as best illustrated in FIGS. 10 and 11 . Accordingly, the sensor 26 has a second or compressed state where at least a portion of one of the conductive foam layers 46 , 48 is in abutting contact with a portion of the other conductive foam layer 46 , 48 . This abutting contact, identified in FIG. 11 by numeral 60 , makes an electrical connection which permits current to flow through the sensor 26 and from one of the foam layers 46 , 48 to the other. As such, in the compressed state, the sensor 26 acts as a closed switch to complete the electrical circuit 30 .
[0033] The conductive foam used in the outer layers 46 , 48 , has a known resistance per length or distance between connection points. Accordingly, if a piece of the conductive foam were to be placed in a circuit with a contact going in one end of the foam and another out the other end, if the distance between the contacts through the foam was known, a known resistance level could be calculated. The resistance level could be changed slightly by compression of the foam thereby decreasing the resistivity of the foam piece. While the connections to the conductive layers 46 , 48 of the sensor 26 can be made by inserting wires 28 therein, as illustrated in FIGS. 3 , 4 and 8 , the wires 28 can also be connected to the conductive layer by way of a piece of conductive copper tape 62 with a conductive adhesive, as best illustrated in FIGS. 7 and 12 .
[0034] With a known resistivity for the conductive foam, the location at which the wires 28 are connected to the outer layers 46 , 48 will have an effect on the voltage across the sensor 26 . For example, in FIG. 8 , the leads are wires 28 are connected to the sensor on opposite sides and at opposite ends. Consequently, a single connection point between the outer layers 46 , 48 towards the upper portion of the sensor in FIG. 8 will result in a resistance that is similar to a single connection by compression at the lower end of the sensor 26 . Alternatively, if both leads were placed in the sensor on opposite sides at about the same location, the resistance would appear differently if the connection occurred farther away from the leads than if the connection occurred closer to the leads. These differences can be used and incorporated into the responses that are given, depending on the desired purpose of the sensor.
[0035] In addition to the compressing of the conductive foam changing the resistance through the foam, the amount of surface area connection between the inwardly facing surfaces 58 of the two outer conductive foam layers 46 , 48 also changes the resistance across the sensor 26 and can be measured as a change in voltage by the micro-processor 22 . In that regard, if contact is only made between the two layers 46 , 48 through one hole 56 in the non-conductive or insulated foam layer 50 , a first resistivity value occurs that is associated with a first voltage level through the circuit 30 . If, however, more of the sensor 26 is compressed such that contact is made between the two layers 46 , 48 through multiple holes 56 , as illustrated in FIGS. 10 and 11 , an alternate and decreased resistance level is provided across the sensor 26 resulting in a second resistance and, in turn, a second voltage through the circuit that can be measured again by the micro-processor 22 . These detected changes correlate with a level of interaction with the sensor 26 and, in turn, changes in a level of interaction with the item, such as the plush toy 10 into which the sensor 26 is inserted. These detected changes can be used to create responses to the changes in interaction such as, for example, varying audio messages that are played back to the user or child 16 by the micro-processor 22 through the speaker 24 . For instance, in one example, a child may gently squeeze the plush toy 10 just enough to compress the sensor 26 sufficiently such that the outer layers 46 and 48 connect with each other through one hole 56 . The micro-processor can notice the change in the circuit 30 from an open circuit to a closed circuit and can associate the resulting voltage through the circuit 30 with an appropriate response message. An exemplary response message would be “Thanks for the gentle hug. Can you give a bear hug too?” Should the child 16 squeeze harder, such that a greater amount of surface area of the two foam layers 46 , 48 abut one another through multiple holes 56 in the insulation layer 50 , the micro-processor 22 can recognize the resulting voltage change, associated with an increased compression or squeeze of the sensor 26 and output an appropriate response, such as “You did it! Are you a bear too?” It should be noted that other responses, apart from audio responses, may be made based on detected changes by the sensor. Other responses may include for example, but are not limited to, activation or modification of light output, motion or data output based on the sensor readings, as well as changes in volume of audio outputs.
[0036] The sensor 26 may be placed inside a fabric pouch 64 , similar to a pillow case, with the wire leads exiting the pouch. This assists with assembly of the plush toy 10 and allows for positioning of the sensor 26 in a desired location in the plush by securing, such as by sewing, a portion of the pouch 64 to the outer layer 12 , as illustrated in FIGS. 5 and 6 . While the sensor 26 has been described as having a use for incorporation into a plush toy for detecting squeezes or hugs thereof, the sensor 26 can be used in a number of environments and should not be limited to one particular use.
[0037] The adhesive layers 52 , 54 , as discussed above, work to not only hold the sensor 26 together but to prevent distortion or shrinking/closing of the apertures 56 in the non-conductive layer 50 , thereby keeping them open to permit the opposing layers 46 , 48 to abut therein. The adhesive layers 52 , 54 can take the form of a two-sided non-conductive adhesive tape, as illustrated in FIG. 12 , or may be a liquid, such as a glue, applied via conventional solution coaters. One possible manufacturing method for the embodiment of the sensor 26 illustrated in FIG. 12 includes using sheets of double-sided tape having a non-adhesive backer applied to both sides of the tape. A sheet of the tape may then have the backer layer removed from one of the sides of the tape to reveal the adhesive surface and placing the tape on one side of a sheet of non-conductive foam. A similar step may be taken by placing a second sheet of adhesive tape on the other side of the non-conductive foam sheet. The three layered resulting assembly may be then passed to a machine where it is die cut to not only form the apertures 56 but to also size the middle layer 50 of the sensor 26 . In this manufacturing method, holes 66 are cut through the double-sided tape that forms the adhesive layers 52 and 54 at the same time as the holes 56 are cut through the insulation layer 50 . As such, the holes 56 , 66 align. The three layer assembly may then be passed on to have the outer conductive foam layers 46 , 48 applied thereto by removal of the backing sheets on the outer surfaces of the double sided tape, thereby revealing the adhesive layer on the outer surfaces of the three layered assembly and creating the sensor 26 illustrated in FIGS. 7 through 12 .
[0038] FIGS. 13 through 16 illustrate an alternate embodiment of the sensor 26 . In this embodiment, an additional outermost layer of nonconductive foam 68 is secured to an outer surface 70 of the conductive foam layer 46 . The outer layer of nonconductive foam material 68 provides the sensor 26 with increased resiliency and firmness without compromising its soft nature.
[0039] Many variations can be made to the illustrated embodiments of the present invention without departing from the scope of the present invention. Such modifications are within the scope of the present invention. For example, the circumference, shape, and number of holes 56 may be modified depending on the characteristics desired in the sensor 26 . In that regard, the holes may be round, square, triangular, etc. There may be a single hole or a plurality of holes. Also, the holes may be small or large and the thickness of the insulating layer may be modified. Additionally, while the sensor has been shown as a generally plainer item, the sensor could be constructed as a cylinder or other shapes depending on the desired properties and configuration. Further, while the wires 28 are shown connected to the sensor in one embodiment by way of a coppered tape 62 , other methods, such as two sided conductive tape (carbon infused, conductive polymers, and the like), conductive adhesives including “super glues”, epoxies and other conductive adhesives or other methods known in the art for holding electrical leads in low electrically resistive contact with the conductive foam are acceptable. Similarly, the electrically conductive lead or wire 28 could simply be inserted into an area of the conductive foam and secured therein by applying a conductive adhesive to the lead prior to inserting it into the foam or by applying adhesive to the lead where it exits the foam. Further still, while the conductive and non-conductive layers have been identified as a foam, any compressive or stretchable material with the same conductivity properties will suffice. Other modifications would be within the scope of the present invention.
[0040] From the foregoing it will be seen that this invention is one well adapted to attain all ends and objects hereinabove set forth together with the other advantages which are obvious and which are inherent to the method and apparatus. It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the invention.
[0041] Since many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative of applications of the principles of this invention, and not in a limiting sense.
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A plush toy having electronics therein for interacting with a user includes a non-rigid electrical component for detecting deformation thereof. The component includes a first layer of a compressible material with at least one aperture therethrough. Second and third layers of an electrically conductive material are positioned on opposite sides of the first layer across the aperture. The second and third layers of material may be brought into contact with each other in the aperture of the first layer to complete an electrical connection between the second and third layers by compression of the first layer upon application of a compression force. When the compression force is removed, the first material expands to separate the second and third layers, thereby breaking the electrical connection. Upon detection of deformation of the electrical component, the electronics activate a response by the toy, such as an audio response.
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RELATED APPLICATIONS
This application is a non-provisional filing of and claims priority to U.S. Provisional Application 61/880,270, titled “DISPENSER PUMP USING ELECTRICALLY ACTIVATED MATERIAL” and filed on Sep. 20, 2013, which is incorporated herein by reference.
FIELD OF THE INVENTION
The current invention pertains to pumping mechanisms used in fluid product dispensers, and more specifically to pumping mechanisms that use electrically activating polymers to pressurize a fluid chamber for dispensing fluid product through a nozzle.
BACKGROUND OF THE INVENTION
It is known in the art to dispense hand care products from a dispenser mounted to a wall or stand. Such dispensers typically have a replaceable reservoir containing hand soap, lotion or sanitizer. Some models dispense product automatically by sensing when a person's hand has been placed under the dispenser. The sensor sends signals to a controller, which in turn operates a pump that forces fluid through a nozzle and onto the person's hand.
Dispensers may be conveniently located in building entrances, bathrooms, or lunchrooms providing convenient accessibility to passersby. However, not all areas are appropriately suited for supplying power to dispensers. As such, dispensers are typically equipped with an onboard power source, typically batteries.
However, drain on the batteries can be significant. Pumps are actuated by motors, which include gears or other forms of transmission inherently possessing significant power losses. Sensors and control circuitry add additional drain to the onboard power source. Thus, frequent maintenance of the automatic dispensers is needed and cost is incurred with the regular replacement of batteries.
Moreover, traditional pump actuators are relatively large, precluding the use of automatic dispensers in areas where limited space is available.
It would therefore be advantageous to provide an automatic dispenser having a low power consumption profile and a small foot print, while maintaining the functional benefits of a touch-less dispenser. The present invention obviates the aforementioned problems.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a fluid product dispenser according to the embodiments of the present invention.
FIG. 2 is a cross-sectional view of the fluid product dispenser showing the internal components of the dispenser.
FIG. 3 is a cross-sectional view showing a schematic representation of a fluid product pump in the electrically de-energized state according to the embodiments of the present invention.
FIG. 4 is a cross-sectional view showing a schematic representation of a fluid product pump in the electrically energized state according to the embodiments of the present invention.
FIG. 5 is a cross-sectional view showing a schematic representation of another embodiment of the fluid product pump according to the embodiments of the present invention.
DETAILED DESCRIPTION
With reference to FIG. 1 , a product dispenser according to the embodiments of the present invention is shown and indicated generally at 10 . Dispenser 10 meters out product, which may include hand care products like soap, lotions or sanitizers, although other types of fluid products may be dispensed from the product dispenser.
Referencing FIGS. 1 and 2 , dispenser 10 includes a base 14 and a cover 18 which when closed define an internal area that holds the components of the dispenser 10 . The base 14 may be generally rigid having a structural configuration suitable for supporting a pump and a fluid reservoir 30 , as well as other components to be discussed later. The dispenser 10 can be mounted to a wall, stand or other structure, not shown in the figures, and so the base 14 includes mounting holes or brackets capable of receiving one or more fasteners. The base 14 may further include a hinge 22 onto which the cover 18 is pivotally attached. A latch 26 secures the 18 cover in place and manually releases to allow access to the interior region of the dispenser 10 . In one exemplary manner, the cover 18 may be generally concave and may include a window 11 positioned to allow service personnel visual access to the fluid reservoir 30 .
Still referencing FIG. 2 , fluid reservoir 30 is constructed to contain hand care products. The reservoir 30 may be a reusable container and refilled with product as needed. Alternatively, the reservoir 30 may be disposable and replaced when empty. Access to the reservoir 30 is gained by unlatching and pivoting the cover 18 away from the base 14 thereby exposing the interior of the dispenser 10 . In one embodiment, the reservoir 30 may held in place by a ledge and/or wall extended from the base 14 . Generally, the reservoir 30 is removed and replaced with another reservoir 30 for sanitary reasons. Such replaceable reservoirs are referred to hereafter as refill units 34 .
The refill unit 34 may be constructed from pliable sheet-like material, referred to as a bag, and may include an outlet attached to a side or an end of the bag. Still other refill units 34 may be constructed from generally rigid or semi-rigid plastic for use in an upright or an inverted mounting configuration. In FIG. 2 , the refill unit 34 is stored completely within the dispenser housing. However, other structural and mounting configurations for the refill unit 34 may be selected without departing from the intended scope of coverage of the embodiments of the present invention.
Referring now to FIGS. 2 and 3 , an exemplary embodiment of a dispenser pump 40 is shown having a pump inlet 42 and a pump outlet 46 . The pump outlet 46 is connected to a nozzle 47 for dispensing fluid product from the dispenser 10 . The pump inlet 42 is fluidly connected to the refill unit 34 . More specifically, the pump inlet 42 is connected to an end of the refill unit 34 to minimize waste. In one embodiment, the pump 40 is disposable and is provided attached to the refill unit 34 as an assembly. In this manner, every wetted component of the dispenser 10 is disposed of when the refill unit 34 is replaced.
Still referencing FIG. 3 , pump 40 includes a pumping chamber shown generally at 50 . In the embodiment currently described, pumping chamber 50 has a generally concave region 52 . Inlet 42 extends from a top side of the concave region 52 and outlet 46 extends from the distal bottom end of the concave region 52 , although other positions of the inlet and outlet relative to the pumping chamber 50 may be chosen with sound judgment. In this way, gravity assists in drawing product from the refill unit 34 into the concave region 52 . An actuator, discussed in detail below, pressurizes chamber 50 thereby expelling product through the outlet 46 and the nozzle 47 . It will be appreciated that other configurations of pumping chambers 50 may be used without departing from the intended scope of coverage of the embodiments of the present invention.
Fluid in the pumping chamber 50 may be pressurized by displacing one or more walls that make up the pumping chamber 50 . In the preferred embodiment, chamber 50 may be constructed from one or more rigid wall sections 53 and by a flexible membrane 70 . Pressure is generated in the concave region 52 from a biasing device 54 located adjacent the flexible membrane 70 . In one embodiment, biasing device 54 comprises a leaf spring, or a coil spring 55 . However, other types of springs or biasing devices may be used. Force from the biasing device 54 pushes against the membrane 70 constricting the volume of fluid in the chamber 50 thereby pressurizing the product inside.
With continued reference to FIG. 3 , membrane 70 is constructed from flexible polymeric material. The flexible material possesses memory and has a predetermined stiffness, i.e. resistance to bending. In one embodiment, membrane 70 is made from Silicone, or alternatively from Polyurethane. However, it should be construed that other types of material that have the requisite characteristics of stiffness and memory may be used as needed for operation of the pump 40 . Accordingly, after membrane 70 is displaced, i.e. biased by device 54 , it will tend to retain its original shape and return to its unbiased configuration when the force is removed. It will be appreciated that the spring constants of the biasing device 54 may be matched to the stiffness of the membrane 70 in a manner suitable for operation of the dispenser 10 as described herein.
The membrane 70 further includes electrically conductive material applied to each of its opposing faces 70 ′, 70 ″. In one embodiment, the electrically conductive material comprises carbon particles adhered to the surface of the membrane in a relatively thin layer. Each face 70 ′, 70 ″ of the membrane, and more specifically each of the electrically conductive layers 72 , is respectively connected to opposite polarity terminals of a DC voltage power source. When a threshold magnitude of voltage is applied to the membrane 70 , its stiffness is altered by the attraction of the conductive layers 72 pressing together. As such, the membrane 70 , in effect, temporarily loses some of its stiffness becoming more pliable and therefore subject to displacement from the force of the biasing device 54 (reference FIG. 4 ). Consequently, when the voltage potential is removed the memory of the base material returns the membrane 70 to its original shape thus overcoming the bias force (reference FIG. 3 ). It can be readily seen then that energizing and de-energizing the voltage source results in the compression and de-compression of the pumping chamber 50 thereby facilitating pumping of product from the dispenser 10 .
It will be understood by persons of skill in the art that the polymeric material of the membrane 70 functions as a dielectric between the electrically conductive layers 72 . The polarizing effect of the applied voltage alters the characteristics of membrane 70 as described above. Voltages applied to the membrane 70 may be in the range of 2 kV to 4 kV. However, any range of voltage potential may be applied as is appropriate for use in actuating the pump 40 . In that the phenomenon of altering the stiffness of a dielectric polymer by the application of voltage is known in the art, no further explanation will be offered here.
To ensure that product flows properly through the nozzle 47 , one or more valves are incorporated into pump 40 . In one embodiment, a first valve, shown generally at 80 , is fluidly communicated with inlet 42 . Additionally, a second valve, shown generally at 81 , is fluidly connected to outlet 46 . When activated in proper succession, the valves 80 , 81 prevent the back flow of product into refill unit 34 and prevent product from leaking through the nozzle before the dispenser is activated.
With reference again to FIGS. 3 and 4 , membrane 70 may be used as valves 80 , 81 to selectively open and close inlet 42 and outlet 46 as mentioned above. In one embodiment of the present invention, an additional biasing device 57 may be positioned adjacent to membrane 70 and in proximity to inlet 42 . When voltage is applied to the conductive layers 72 in a manner previously described, membrane 70 loses stiffness over the entire area covered by the conductive layers 72 . Accordingly, membrane 70 becomes more pliable allowing biasing device 57 to press membrane 70 into sealing contact with the inlet 42 thereby preventing fluid flow back into the refill unit 34 .
It is noted that biasing devices 54 and 57 displace membrane 70 at the same time. Accordingly, it is contemplated in an alternate embodiment that one single biasing device, not shown in the figures, may be used to both displace fluid from the pumping chamber 50 and seal the inlet 42 . Thus the biasing device may be specifically configured and the inlet 42 may be positioned proximal to the pumping chamber to facilitate both actions with a single biasing element.
Referring still to FIGS. 3 and 4 , another separate biasing device 59 may be included and positioned to engage membrane 70 at the location of the outlet 46 . It is noted that the inlet 42 and outlet 46 must be fluidly sealed at opposite times during operation of the pump 40 . Hence, biasing device 59 is positioned to move membrane 70 away from the outlet 46 when fluid in the pumping chamber 50 is pressurized. It follows that, in the de-energized state, membrane 70 is configured to cover the outlet 46 thereby preventing fluid flow therethrough.
With reference now to FIGS. 3 and 5 , to ensure against leaks through outlet 46 in the de-energized state, a raised rim 49 may be positioned around the opening of the outlet 46 . Additionally, protrusions, referred to herein as ribs 51 , may be fashioned to extend from the one or more rigid wall sections 53 opposite that of the raised rim 49 . In this way, the stiffness and memory of the membrane 70 force it into contact with the outlet 46 in a crimping action (reference FIG. 5 ).
It will be appreciated that pressurized fluid will act on the membrane 70 to move it out of engagement with the outlet 46 . As such, FIG. 5 depicts an embodiment of the present invention that does not include a dedicated biasing device to force the membrane 70 out of engagement with the outlet 46 . Accordingly, the stiffness and/or thickness of the membrane 70 may be selected so that as pressure in the pumping chamber 50 increases, a threshold is reached that overcomes the rigidity of the membrane 70 thus allowing fluid to flow through the nozzle 47 . While the current embodiment depicts both rim 49 and ribs 51 , variations are contemplated excluding one or the other of these components.
Having illustrated and described the principles of this invention in one or more embodiments thereof, it should be readily apparent to those skilled in the art that the invention can be modified in arrangement and detail without departing from such principles.
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Apparatuses and techniques are provided for dispensing fluid from a dispenser that includes a flexible membrane having different levels of pliability according to a voltage applied to the flexible membrane. According to some embodiments, a biasing device, such as a spring, is disposed on a first side of the flexible membrane and is configured to apply pressure to the flexible membrane. When a first voltage is applied to the flexible membrane, the flexible membrane becomes sufficiently pliable to enable the spring to flex the flexible membrane, pushing the flexible membrane into a pumping chamber disposed on the opposite side of the flexible membrane relative to the spring. The fluid is stored in the pumping chamber and the flexing of the flexible membrane causes the pumping chamber to compress. Such compression of the pumping chamber forces the pumping chamber to dispense the fluid through a pump outlet.
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CROSS-REFERENCE TO RELATED APPLICATIONS
(Not Applicable)
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
(Not Applicable)
BACKGROUND OF THE INVENTION
This invention relates generally to devices that measure the orientation of bodies and more specifically to devices that measure the orientation of rotating bodies that are used in measuring acceleration.
The accelerometers used in inertial navigation systems are typically of the pendulous torque-to-balance variety. A typical unit uses a hinged pendulum as the acceleration sensing body. An orientation sensor produces an error signal when the pendulum begins to pivot away from its desired null position as a result of an acceleration, and this error signal is used by a control circuit to maintain the pendulum in its null position by means of an electrical control signal applied to a torquing device. The magnitude of the electrical control signal is proportional to the acceleration and thus is a measure of the acceleration.
The centripetal opposed pendulous accelerometer (COPA) described herein offers a new approach to the design of precision accelerometers in that it utilizes a spinning body as the acceleration sensing element. The sensing element spins in a dry environment, and there are consequently no fluid migration/stratification/compatibility issues which might argue against a long operating life. No electrical connections to the sensing element are required, and the device is radiation hard.
The operation of a COPA entails measuring the tilt of the sensing element with an orientation sensor. The preferred orientation sensor is one which measures the tilt of the sensing element by the deflection of a beam of light reflected from a surface of the sensing element. A precise measurement of tilt can be achieved only if the intensity of the light is precisely regulated.
BRIEF SUMMARY OF THE INVENTION
A centripetal opposed pendulous accelerometer utilizes a sensing body which senses acceleration when rotated or oscillated about the y'-axis of an x'-y'-z' Cartesian coordinate system, the product of inertia I xy . of the sensing body being greater than zero. The product of inertia is computed with respect to an x-y-z coordinate system fixed in the sensing body, the z-axis being in the x'-z' plane, the y and y' axes being aligned in the absence of acceleration.
The sensing body is pivotally attached to a platform, the sensing body pivoting about an axis parallel to the z-axis. A torquing device applies a torque about the z-axis to the sensing body sufficient to cause the average angle between the y-axis and the y'-axis to be zero in the absence of acceleration when the sensing body is being oscillated at a predetermined rate.
The accelerometer also includes an orientation sensor which provides a measure of the average angle between the y-axis and the y'-axis. A drive assembly rotates or oscillates the platform about the y'-axis. A control circuit receives the output of the orientation sensor and causes the drive assembly to rotate or oscillate the platform at a frequency and amplitude which causes the orientation angle to be near zero.
A key element of the orientation sensor is a laser diode which illuminates a plurality of regions of a photodetector thereby causing photodetector regional currents to flow out of the photodetector. The invention is a method and apparatus for regulating the light intensity of the laser diode The method comprises the steps of (a) combining the photdetector regional currents and scaling the result to obtain a scaled total photodetector current, (b) generating a reference current, (c) generating a difference current measure, the difference current measure being monotonically related to the difference of the scaled total photodetector current and the reference current, (d) transforming the difference current measure into a control voltage, and (e) causing the current through the laser diode to vary monotonically with the control voltage.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates the principle of operation of a centripetal opposed pendulous accelerometer utilizing a single sensing body.
FIG. 2 illustrates the principle of operation of a centripetal opposed pendulous accelerometer utilizing two sensing bodies.
FIG. 3 illustrates a sensing body having mass distributed in both the first and second quadrants of a Cartesian coordinate system and a pivot point on the axis of rotation.
FIG. 4 shows a sensing body having mass distributed in both the first and second quadrants of a Cartesian coordinate system and a pivot point offset from the axis of rotation.
FIG. 5 shows two independently operating sensing bodies which pivot in opposite directions as a result of an acceleration.
FIG. 6 shows the preferred embodiment of the sensing body for the centripetal opposed pendulous accelerometer.
FIG. 7 shows a cut-away view of the preferred embodiment of a centripetal opposed pendulous accelerometer.
FIG. 8 shows the flexures which support the sensing body of FIG. 7 on the platform.
FIG. 9 shows a cut-away view of the sensing body/platform assembly which reveals the details of the torquing device.
FIG. 10 shows an alternative torquing device.
FIG. 11 shows the details of the orientation sensor.
FIG. 12 illustrates the operation of the damping apparatus which damps oscillations of the sensing body.
FIG. 13 shows a block diagram that mathematically defines the dynamics of the centripetal opposed pendulous accelerometer with a rotating sensing body.
FIG. 14 shows a block diagram that mathematically defines the dynamics of the centripetal opposed pendulous accelerometer with an oscillating sensing body.
FIG. 15 shows a block diagram of the light-intensity regulating system for the orientation sensor.
FIG. 16 shows a circuit diagram of the light intensity regulating system for the orientation sensor.
DETAILED DESCRIPTION OF THE INVENTION
The principle of operation of the centripetal opposed pendulous accelerometer (COPA) is illustrated in FIG. 1. The sensing body 1 is attached to the platform 2 by the flexure 3. The x-y-z Cartesian coordinate system shown in the figure (z axis out of the paper) is fixed with respect to the sensing body 1. The flexure 3 constrains the movement of the sensing body 1 to the x-y plane. In the absence of any acceleration, the platform 2 is spun at a rate Ω 0 which causes the sensing body 1 to assume the position shown in the figure, the force applied by the flexure 3 just balancing the centrifugal force on the sensing unit as a result of the spinning about the y-axis. If there is now an acceleration in either of the directions indicated by the two-headed arrow, the sensing body 1 will attempt to rotate about the z-axis in the direction of the acceleration. A change in position of the sensing body 1 in the x-y-z coordinate system is detected by the change in capacitance between the sensing body 1 and a conducting ring 4 attached to the support structure (or case) 5 of the accelerometer. A control circuit, not shown, causes the spin rate to either increase or decrease to keep the capacitance the same and the position of the sensing body 1 unchanged. The change in spin rate is nearly proportional to the acceleration.
The equation of motion for the sensing body is
I.sub.zz α+Cω+[K+(I.sub.yy -I.sub.xx)Ω.sup.2 ]θ=mra-I.sub.xy Ω.sup.2 +T.sub.B (1)
The angle θ defines the orientation of the sensing body and the x-y-z coordinate system with respect to the x'-y'-z' coordinate system fixed with respect to the support structure 5. The y-axis coincides with the y-axis when the sensing body 1 is in its null position as shown in the figure. The angle θ is the angle between they axis and the y'-axis (when the sensing body is not in its null position). The time rate of change of θ is denoted by ω and the time rate of change of ω is denoted by α. The damping coefficient is denoted by C, and the spring coefficient of the flexure is denoted by K. The moments and products of inertia of the sensing body 1 are denoted by I with appropriate subscripts. The spin rate of the sensing body 1 is denoted by Ω=Ω 0 +ΔΩ. The symbol m stands for the mass of the sensing body 1, r is the distance of the center of mass of the sensing body 1 from the y-z plane, and a is the acceleration. The symbol T B represents any additional torque exerted on the sensing body 1.
Under steady-state conditions α, ω, and θ are all equal to zero, and
α=(I.sub.xy /P)Ω.sub.0.sup.2 [2(ΔΩ/Ω.sub.0)+(ΔΩ/Ω.sub.0.sup.2 ](2)
where P, the pendulosity, is the product of m and r. Note first that a is very nearly a linear function of ΔΩ since ΔΩ is small compared to Ω 0 . Second, note that this technique for measuring acceleration requires that the sensing body have a non-zero I xy .
The configuration shown in FIG. 2 provides both a statically- and dynamically-balanced load for the drive assembly. Two sensing bodies 6 and 7 are used, each with its own flexure. The configuration of FIG. 2 can be expanded by adding more sensing bodies, each sensing body having its own flexure, until the sensing bodies form a cone.
A somewhat different configuration is shown in FIG. 3. Here, the mass of the sensing body 8 is distributed on both sides of the flexure 9. All of the mass additively contributes to the magnitude of I xy . However, the distribution of mass in the two x-y quadrants must be such as to give a center of mass offset in the x-direction from the flexure 9. This configuration has the same disadvantage as the configuration of FIG. 1 in that the sensing body is a statically unbalanced load as far as the driving assembly is concerned.
In the configuration of FIG. 4, the sensing body 10 is a statically balanced load as far as the driving assembly is concerned in that the center of mass 11 is on the axis of rotation. Even with the center of mass on the axis of rotation, the sensing body 10 is still able to sense acceleration because the pivot point of the flexure 12 is displaced from the axis of rotation.
In the configuration of FIG. 5, sensing bodies 13 and 14, which are like sensing body 10 in FIG. 4, are mounted such that they pivot in opposite directions as a result of an acceleration. Assuming a positive acceleration, sensing body 13 would have to be rotated at a rate of Ω 1 Ω=Ω 0 +ΔΩ 1 and sensing body 14 at a rate of Ω 2 =Ω 0 +ΔΩ 2 , where ΔΩ 1 is positive and ΔΩ 2 is negative if the orientations shown in FIG. 5 were to be maintained. The rate Ω 0 is the rate required to maintain both sensing bodies 13 and 14 in the FIG. 5 orientations in the absence of an acceleration and assuming sensing bodies 13 and 14 have the same product of inertia I xy .
The acceleration under these circumstances is given by ##EQU1## where P 1 and P 2 are the pendulosities of sensing bodies 13 and 14 respectively. If the difference in magnitudes of ΔΩ 1 and ΔΩ 2 is small and Ω 0 is large, the above equation approaches ##EQU2## which is a linear relationship. In reality, this relationship will never be reached, but the double-ended instrument of FIG. 5 will be more linear than the single-ended instrument of FIG. 4 as can be seen from a comparison of equations (2) and (3).
It should be noted that the embodiments shown in FIGS. 4 and 5 are statically balanced with respect to accelerations normal to the y-axis and are thus insensitive to such accelerations.
The preferred embodiment of the sensing body 23 with attached flexures 24 is shown in FIG. 6. The properties are as follows:
______________________________________I.sub.xx = 0.109 g · cm m = 0.494 g C = 30 μN · cm/(rad · s) I.sub.yy = 0.109 g · cm P = 0.013 g · cm K = 1.15 mN · cm/rad I.sub.zz = 0.143 g · cm ΔΩ = 2 rad/(s · gravity T.sub.B = 3.32 mN · cm unit) I.sub.xy = 0.032 g · cm Ω.sub.σ = 100 rad/s______________________________________
The center of mass of the sensing body 23 lies on the y-axis. The sensing body 23 is pivotally mounted on a platform by means of the flexures 24 so as to be free to rotate through small angles about an axis parallel to the z-axis. The sensing body-platform assembly is spun about a y'-axis fixed with respect to the platform, the y'-axis coinciding with the y-axis in the absence of acceleration. The sensing body 23 is machined from beryllium.
An embodiment of the COPA accelerometer is shown in FIG. 7. The sensing body 23 of FIG. 6 is shown attached to the platform 25. The platform 25 is mounted to the drive assembly 27 consisting of a brushless servomotor 29, precision ball bearings 31, and drive shaft 33. The drive assembly 27 is attached to the support structure 35. The rotation sensor 37 is a high-accuracy absolute angle resolver which provides servomotor commutation, demodulates the angular pickoff output, and provides a sine/cosine angle readout waveform. The rotary transformer 39 powers the resolver primary.
The sensing body 23 is attached to the platform 25 by two flexures 41 and 43. The flexure design is shown in FIG. 8. The flexures 41, 43 are 190 μm long by 150 μm wide by 127 μm thick and are made of ELIGILOY®. The hinge portion 45 is 64 μm long by 5 μm thick. The properties of the flexures are as follows:
______________________________________K.sub.torshional = 1.13 mN · cm/rad σ.sub.bending = 8 MPa/mrad f.sub.n-torsional = 5 Hz σ.sub.tensile = 296 MPa/N K.sub.translational = 13 μm/N P.sub.critical (buckling) = 7.35 N f.sub.n-translational = 1340 Hz______________________________________
The angular freedom of a flexure is ±10 mrad.
The torquing device 47 provides the torque necessary to maintain the sensing body 23 in its null position while being spun at its zero-acceleration spin rate. The torquing device 47, shown in greater detail in FIG. 9 consists of four permanent magnets 49, 51, 53, and 55 installed on the platform 25 and two permanent magnets 57 and 59 installed in the sensing body 23. The south pole of magnet 57 is adjacent to the north pole of magnet 49, the north pole of magnet 57 is adjacent to the north pole of magnet 51, the north pole of magnet 59 is adjacent to the north pole of magnet 53, and the south pole of magnet 59 is adjacent to the north pole of magnet 55. This arrangement torques the sensing body 23 in a clockwise direction in opposition to the torque on the sensing body 23 that results from spinning the sensing body about the vertical axis. The magnets are made of samarium cobalt, are temperature compensated, and have an energy product of 72,000 T·A/m. The torque exerted by the torquing device 47 is very nearly constant at 33.2 μN·m for rotations of the sensing body 23 over a range of 20 mrad.
An alterative torquing device 58 is shown in FIG. 10. A single permanent magnet 60 is mounted to the sensing element 23. A coil 62 attached to the platform 25 encircles the permanent magnet 60. Current in the coil creates a magnetic field normal to the north-south axis of the permanent magnet 60. The north-south axis attempts to align itself with the magnetic field thereby causing a torque normal to the drawing to be applied to the sensing body 23. The direction of the torque is controllable by the direction of the current in the coil, and the magnitude of the torque is controllable by the magnitude of the current.
The orientation of the sensing body relative to the platform is measured by the orientation sensor 61 (FIG. 7). The orientation sensor 61 is shown in more detail in FIG. 11. A super luminescent diode (SLD) 63 emits light rays which are collimated by the lens 65, reflected by the surface of the sensing body and detected by the PIN diode 67. When the sensing body 23 is in its null position, the light received in the four quadrants of the PIN diode 67 will be balanced. When the sensing body 23 departs from its null position, the light received in the four quadrants will be unbalanced. By appropriate processing of the electrical signals from the four quadrants, an error signal can be obtained which is a measure of the tilt angle of the sensing body 23.
The SLD produces light at a wavelength of 960 nm with a spectral bandwidth of 20 nm and a beam ellipticity of 1.7 to 1. The power output is 3 mW and the coherence length is 400 μm.
The position-sensing PIN photodiode is a standard 2.5-cm diameter quad cell customized with a center hole. The part is available from UDT Sensors Inc. The noise equivalent power of the part is 0.1 pW/√Hz, angle noise is 0.03 μrad/√Hz, and the scale factor is 2.7 mA/rad.
The most significant parameters that affect the intensity of light produced by the SLD 53 are current and temperature. To avoid variations in light intensity the SLD is driven by the light-intensity regulating system 101 shown in FIG. 15 which adjusts the current flowing through the output ports 103 to the SLD to maintain a constant light intensity.
A measure of the light intensity can be obtained by combining the currents from the four quadrants of PIN diode 67. Since substantially all of the light emitted by the SLD is captured by the four quadrants, the combined current from the four quadrants is a measure of the light intensity. Although the use of a four-quadrant photodetector is preferred for the centripetal opposed penulous accelerometer, other applications may dictate that the light-sensitive region of a photodetector be subdivided in other ways. The light-intensity regulating system 101 will work satisfactorily with other photodetector regional configuations if the sum of the photodetector regional subdivisions are a measure of the SLD light intensity.
The photodetector quadrant currents 104 feed into the intensity amplifier 105 which combines the currents and outputs a scaled total photodetector current. This scaled total photodetector current is compared with a reference current supplied by voltage reference 107 in integrator 109 which produces a control voltage at its output which reprepresents the integration of the difference between the scaled total photodetector current and the reference current.
The SLD current is obtained from voltage regulator 111. The control voltage produced by integrator 109 controls the flow of current from voltage regulator 111 through current source 103. When the light intensity decreases/increases, the control voltage causes the current through the SLD to increase/decrease thereby maintaining the light intensity at a constant level.
The current flowing through the SLD is monitored by the current limit circuit 113. If the current exceeds a predetermined threshold, switch 115 opens thereby interrupting the current flow through the SLD.
The light-intensity regulating system 101 is shown in more detail in FIG. 16. When switch S1 is in the off position, pin 1 of U12A (type 74HCT00) is low and pin 3 is high. As a result, DMOS Q3 (type DMOS N) is turned on thereby turning on JFET Q1 (type 2N5116), turning off MOSFET Q2 (type IRF9530), and preventing current from flowing through the SLD.
When switch S1 is switched to the on position, JFET Q3 is turned off and the time constant asssociated with resistors R8 (10 kΩ) and R9 (150 Ω) and capacitor C4 (4.7 μF) prevent turn-on transients by slowly turning JFET Q1 off. The turn-off period for JFET Q1 should be at least 100 microseconds. Operational amplifier U2, voltage regulator U1, MOSFET Q2, and resistor R4 comprise a precision voltage-controlled current source. Operational amplifier U2 turns on Q2 and causes the source current of Q2 to increase until the voltage at pin 2 of U2 equals the control voltage at pin 3.
Voltage reference U5 (type LM399) and operational amplifier U6 (type OP77) provide a reference for voltage regulator U1 (LM317) via operational amplifiers U7 (type OP77) and U3 (type OP77). They also provide a stable refernce for summing amplifier U4 (type OP77).
The four quadrants of the PIN diode 67 (see FIG. 11) are denoted in sequence as the +z', +x', -z', and -x' quadrants. The quadrants surround the origin of the z'-x' coordinate frame of reference with the +z', +x', -z', and -x' quadrants being centered on the corresponding plus and minus semi-axes. The x'-y'-z' coordinate axes are fixed with respect to the COPA, the sensing body 23 being spun about the y' axis.
The +z' quadrant and the -z' quadrant signals are summed at pin 2 of operational amplifier U8 (type OP77) and the +x' quadrant and the -x' quadrant signals are summed at pin 2 of operational amplifier U9 (type OP77). Since the AC signal components of the +z' quadrant and the -z' quadrant signals and the AC signal components of the +x' quadrant and the -x' quadrant signals that result from the spinning of the sensing body are 180 degrees out of phase, they cancel each other out leaving only the DC components.
When the sensing body 23 is in its null position, the currents through resistors R13 (10 kΩ) and R14 (10 kΩ) equal the current through SLD current adjustment potentiometer R29 (0-20 kΩ), and operational amplifier U4 (type OP77) provides a stable control voltage at pin 3 of U2 and hence a constant current through the SLD. With increasing temperature, the quadrant signals decrease in amplitude. Since the current through R13 and R14 no longer equals that through R29, the output of U4 decreases causing the voltage at pin 3 of U2 to further turn on Q2, thereby increasing the current through the SLD and the quadrant currents. When the outputs of U8 and U9 increase the currents through R13 and R14 sufficiently to balance the current through R29, the output of U4 provides a stable control voltage at pin 3 of U2 and a constant current through the SLD.
The output of operational amplifier U10 (type OP77) provides an SLD current monitor test point and an input to compartor U11 (type LM311). When the input of the comparator at pin 2 is greater than that at pin 3, set by the over-current limit potentiometer R28, the output of comparator U11 sets the latch at U12 pin 3 thereby turning on JFETs Q3 and Q1 and turning off the constant current source.
When current through the SLD is interrupted by moving the switch S1 to the off position, an over-current condition, or a loss of power, diodes D3 and D2 prevent a reverse transient from passing throught the SLD.
In order to prevent the sensing body from hitting pivot-angle limit stops during vibratory accelerations, the sensing body should be damped. The eddy current damper 69 shown in FIG. 12 is one approach to providing damping. The sensing body 23 is symbolically represented by the member 71 which pivots about axis 73. The flexures 41, 43 are symbolically represented by the spring 75. The platform 25 is symbolically represented by the diagonal lines 85.
The eddy current damper consists of a copper sheet 77 approximately 0.4 cm square and 0.025 cm thick attached to the sensing body 23 and positioned between magnets 79 and 81 which are attached to the low-reluctance return path 83 which in turn is attached to the platform 25, symbolically represented by the diagonal lines 85. As the copper sheet 77 pivots with the sensing body 71 about the axis 73, the copper sheet moves through the magnetic field lines 87 resulting in the generation of eddy currents 89. Interaction of the eddy currents 89 with the magnetic field lines 87 results in a force on the copper sheet 77 proportional to the velocity of the sheet and in the opposite direction. The damping constant C is equal to the ratio of the eddy-current torque to the angular rate of the copper sheet and is given by the equation
C=(B.sup.2 R.sup.2 At)/ρ (5)
where B is the magnetic flux density, R is the distance of the copper sheet 77 from the pivot axis 73, A is the pole area of the magnets 79, 81, t is the thickness of the copper sheet 77, and ρ is the resistivity of copper. A value for C of 4.0×10 -7 N·m is obtained for the following parameter values: B=0.6733 T, R=0.762 cm, A=0.031 cm 2 , t=0.025 cm, and ρ=5.05×10 -8 Ω·m.
The dynamics of COPA are mathematically defined by the block diagram shown in FIG. 13. The sensing body dynamics are defined in block 91. The symbol I denotes the same quantity as I zz did in FIG. 1. The servo loop transfer function indicated in block 93 is defined by the equation at the bottom of the figure. The platform dynamics are defined in block 95. The symbol J is the moment of inertia of the platform with respect to the spin axis. The symbol D is the damping coefficient for the platform. The values of J and D are 100 g·cm 2 and 4 mN·cm·s respectively. The resolver 97 provides a measure of the angle of rotation of the platform 25.
Rather than cause the sensing body 1 to be driven unidirectionally about the y'-axis, the sensing bodies 1, 6, 7, 8, 10, 13, and 14 can be caused to oscillate about the y-axis. Then the spin rate Ω would be time varying and could, for example, be of the form
Ω=Ω.sub.A sin ((ω.sub.m t) (6)
where Ω A is the amplitude of the rate oscillation and ω m is the angular oscillation frequency. It should be noted that Ω A is the product of the angular oscillation amplitude and the angular oscillation frequency. Consequently, Ω A can be varied either by varying angular oscillation amplitude (angle mode operation) or the angular oscillation frequency (frequency mode operation).
Although the operation of the COPA is described herein in terms of a sinusoidal oscillation, the oscillation should be thought of more generally as being characterized by simply a periodic function.
Substituting for Ω in equation (1), we obtain
I.sub.zz α+Cω+Kθ=mra-I.sub.xy Ω.sub.A.sup.2 sin.sup.2 (ω.sub.m t)+T.sub.B (7)
Generally, the instrument servo seeks to drive the sensing body angle θ and its time derivatives to zero. Under these circumstances, ##EQU3## Since sin 2 (ω m t) is zero some of the time, maintaining θ and its time derivatives at zero would require (Ω A ) 2 to be infinite some of the time. Thus, it is unreasonable to expect the servo to maintain the sensing body at a zero angle of deflection. Rather, it will dither about some mean value at the same frequency as the platform.
However, the servo will be able to drive the mean value of θ to zero. Averaging both sides of equation (8) over a time long compared with 1/ω m and short compared with the time it takes for significant variations in α to occur, we obtain ##EQU4## where we have replaced sin 2 (ω m t) by its average value 1/2.
The instrument scale factor SF can be defined as ##EQU5##
At zero acceleration, the bias torque T B is balanced by a bias platform rate Ω 0 . Solving equation (9) for T B under these circumstances yields the equation ##EQU6## Finally, making use of the above scale factor and bias platform rate, we rearrange equation (9) to obtain an expression for acceleration: ##EQU7##
We now consider implementing a control law in the form ##EQU8## where K P and K I are constants chosen to provide the desired closed-loop response. This equation basically describes the well-known proportional-integral controller with an offset. Substituting for Ω in equation (1), we obtain
I.sub.zz α+Cω+[K+I.sub.xy K.sub.P sin.sup.2 (ω.sub.m t)]θ+I.sub.xy K.sub.I sin.sup.2 (ω.sub.m t)ƒθdt=mra-I.sub.xy Ω.sub.0.sup.2 sin.sup.2 (ω.sub.m t)+T.sub.B (14)
If ω m is made large compared to the highest frequency likely to be experienced in α, then we may replace the terms in the above equation by their average values over an oscillatory cycle. We represent θ by a Fourier series in ω m t and include in the above equation only the first term θ a and the time derivatives of the first term ω a and α a . ##EQU9## which represents a linear system. Choosing the bias torque T B and the bias platform rate Ω 0 such that the terms which contain the two quantities cancel each other, we obtain ##EQU10## Since this system is linear and time-invariant, all of the well-known compensator design techniques can be used to arrive at the desired closed-loop response for the system. Furthermore, the behavior of this system will approximate the behavior of the oscillating system, especially if the oscillation frequency is large.
Typical values for the parameters are as follows:
______________________________________sensing body moment of inertia (I.sub.zz) 1.440 × 10.sup.-8 kg · m.sup.2 sensing body damping coefficient (C) 4.000 × 10.sup.-3 N · s/m flexure spring constant (K) 1.000 × 10.sup.-5 N · m/rad pendulosity (P) 1.300 × 10.sup.-7 kg .multidot . m sensing element product of inertia (I.sub.xy) 3.320 × 10.sup.-9 kg · m.sup.2 zero-acceleration oscillation rate (Ω.sub.0) 1.410 × 10.sup.2 rad/s scale factor (SF) 7.830 × 10.sup.1 rad.sup.2 /m instrument bias (Ω.sup.2.sub.0 /SF) 2.539 × 10.sup.2 m/s.sup.2 sensing body scale factor (P/K) 1.300 × 10.sup.-2 rad · s.sup.2 /m oscillation angular frequency (ω.sub.m) angle mode (fixed oscillation frequency) 6.283 × 10.sup.3 rad/s frequency mode (fixed oscillation amplitude) 1.977 × 10.sup.4 rad/s (25 g.sub.n) 1.410 × 10.sup.4 rad/s (0 g.sub.n) 2.597 × 10.sup.3 rad/s (-25 g.sub.n) oscillation amplitude angle mode (fixed oscillation frequency) 3.147 × 10.sup.-2 rad (25 g.sub.n) 2.244 × 10.sup.-2 rad(0 g.sub.n) 4.134 × 10.sup.-3 rad (-25 g.sub.n) frequency mode (fixed oscillation amplitude) 1.000 × 10.sup.-2______________________________________ rad
The sensing body scale factor is the tilt angle of the sensing body per unit acceleration. The symbol g n stands for the standard acceleration of gravity.
In implementing the oscillating version of the sensing body, certain simplifications are possible. Since the platform 25 (FIG. 7) does not continually rotate, the requirement for ball bearings 31 disappears. Furthermore, the measurement of the orientation angle of the sensing body 23 becomes much simpler since the sensing body no longer rotates with respect to the support structure 35.
The dynamics of COPA having an oscillating sensing body is illustrated by the block diagram shown in FIG. 14.
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The COPA accelerometer utilizes a sensing body having a non-zero product of inertia to sense acceleration when spun or oscillated about the y'-axis of an x'-y'-z' Cartesian coordinate system. The sensing body is pivotally attached to a platform and pivots about an axis parallel to the z-axis of an x-y-z coordinate system fixed in the sensing body, the z-axis being in the x'-z' plane. An orientation sensor provides a measure of the average angle between the y-axis and the y'-axis. The orientation sensor contains a laser diode which illuminates a plurality of regions of a photodetector thereby causing photodetector regional currents to flow out of the photodetector. The light intensity of the laser diode is regulated by (a) combining the photdetector regional currents and scaling the result to obtain a scaled total photodetector current, (b) generating a reference current, (c) generating a difference current measure, the difference current measure being monotonically related to the difference of the scaled total photodetector current and the reference current, (d) transforming the difference current measure into a control voltage, and (e) causing the current through the laser diode to vary monotonically with the control voltage.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This is a divisional patent application of U.S. patent application Ser. No. 10/287,153, filed Nov. 4, 2002, which claims the benefit of the filing date of U.S. Patent Application No. 60/338,901, filed on Nov. 5, 2001, the entire contents of which are hereby expressly incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to compositions and methods for increasing patient compliance with therapies comprising the administration of aldehyde dehydrogenase inhibitors, and for preventing, ameliorating or treating alcoholism. Such compositions and methods may be used to facilitate alcohol cessation, and may comprise a combination of aldehyde dehydrogenase inhibitors and monoamine oxidase inhibitors.
2. Description of the Related Art
Alcohol is a commonly abused drug. According to the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV), problematic alcohol use is divided into alcohol abuse and alcohol dependence.
Alcohol abuse involves recurrent alcohol consumption that negatively affects one's life, whereas alcohol dependence includes alcohol abuse and additionally symptoms of tolerance and withdrawal [McRae et al., “Alcohol and Substance Abuse,” In: Advances in Pathophysiology and Treatment of Psychiatric Disorders: Implications for Internal medicine, 85(d):779-801 (2001); Swift, R. M., New England J. Med. 340:1482-1490 (1999); Kick, S., Hospital Practice 95-106 (1999)]. In 1997, the estimated lifetime prevalence for alcohol abuse was 9.4% and for alcohol dependence was 14.1%, with men having significantly higher rates of dependence than women [McRae et al., supra]. Alcohol abuse and dependence commonly lead to other problems such as alcohol-related violence, motor vehicle accidents, and medical consequences of chronic alcohol ingestion including death [McRae et al., supra; Swift, supra].
One of the pharmacotherapies that have been suggested for treating alcoholism, including facilitating alcohol cessation, is the administration of agents that inhibiting the enzyme aldehyde dehydrogenase (ALDH), an enzyme involved in the removal of acetaldehyde, a toxic metabolite of alcohol. Examples of ALDH inhibitors include, e.g., disulfiram, coprine, cyanamide, 1-aminocyclopropanol (ACP), daidzin, cephalosporins, antidiabetic sulfonyl ureas, metronidazole, and any of their metabolites or analogs exhibiting ALDH-inhibiting activity including, e.g., S-methyl N,N-diethyldithiocarbamate, S-methyl N,N-diethyldithiocarbamate sulfoxide, and S-methyl N,N-diethylthiocarbamate sulfoxide. Patients who consume such inhibitors of ALDH experience mild to severe discomfort if they ingest alcohol. The efficacy of therapies using ALDH inhibitors depends on the patient's own motivation to self-administer the ALDH inhibitors, e.g., oral forms of the inhibitors, or to receive additional therapies, e.g., DEPO forms of disulfiram. In fact, patient compliance is a significant problem with these types of therapies.
Although multiple forms of ALDH exist. ALDH-I (also known as ALDH- 2 ) and ALDH-II (also known as ALDH- 1 ) are the major enzymes responsible for the oxidation of acetaldehyde. ALDH-I has a higher affinity for acetaldehyde than ALDH-II, and is thought to be the primary enzyme involved in alcohol detoxification [Keung, W. M., et al., Proc. Natl. Acad. Sci. USA 95:2198-2203 (1998)]. The discovery that 50% of the Asian population carries a mutation in ALDH-I that inactivates the enzyme, together with the low occurrence of alcohol abuse in this population supports the contention that it is this isozyme of ALDH that is primarily responsible for alcohol detoxification. Recent studies also implicate ALDH-I in the metabolism of monoamine neurotransmitters such as serotonin (5-HT) and dopamine (DA) [Keung, W. M., et al., Proc. Natl. Acad. Sci. USA 95:2198-2203 (1998)].
Disulfiram, also known as tetraethylthioperoxydicarbonic diamide, bis-diethylthiocarbamoyl disulfide, tetraethylthiuram disulfide, Cronetal™, Abstenil™, Stopetyl™, Contrain™, Antadix™, Anietanol™, Exhoran™, ethyl thiurad, Antabuse™, Etabuse™, RO-sulfiram, Abstinyl™, Thiuranide™, Esperal™, Tetradine™, Noxal™, Tetraeti™ [Swift, supra], is a potent irreversible inhibitor of ALDH-II and inhibits ALDH-I only slightly. Recent studies suggest that the inhibition of ALDH-I by disulfiram occurs indirectly via its metabolites, e.g., S-methyl-N,N-diethylthiocarbamate sulfoxide (DETC-MeSO) [Yourick et al., Alcohol 4:463 (1987); Yourick et al., Biochem. Pharmacol. 38:413 (1989); Hart et al., Alcohol 7:165 (1990); Madan et al., Drug Metab. Dispos. 23:1153-1162 (1995)]. Ingestion of alcohol while taking disulfiram results in the accumulation of aldehydes, which causes tachycardia, flushing, diaphoresis, dyspnea, nausea and vomiting (also known collectively as the disulfiram or disulfiram-ethanol reaction).
Although disulfiram has been available in the United States for many decades, patients frequently have difficulty complying with disulfiram treatment therapies. One reason for poor compliance is the lack of motivation for the patient to continue to take disulfiram, that is, other than self-motivation (i.e., there is no positive reinforcement for taking disulfiram). Another reason is because of the discomfort that arises if the patient ingests alcohol during disulfiram therapy [McRae et al., supra; Swift, R. M., supra; Kick, S., supra]. In fact, disulfiram has not proven to be useful in maintaining long-term sobriety [Kick, supra].
Coprine (N5-(hydroxycyclopropyl)-L-glutamine) has been shown to inhibit ALDH via its active metabolite, 1-aminocyclopropanol (ACP). U.S. Pat. No. 4,076,840 describes the synthesis and use of cyclopropyl benzamides, including coprine, for the treatment of alcoholism. In rat studies, coprine effectively suppressed ethanol consumption, and was shown to be a more potent inhibitor of ALDH as compared to disulfiram [Sinclair et al., Adv. Exp. Med. Biol. 132:481-487 (1980); U.S. Pat. No. 4,076,840].
Cyanamide has been described as an alcohol-sensitizing agent that is less toxic than disulfiram [Ferguson, Canad. M.A.J. 74:793-795 (1956); Reilly, Lancet 911-912 (1976)]. Although cyanamide is unable to inhibit either ALDH-I or ALDH-II in vitro, a reactive product of cyanamide catabolism inhibits both isozymes in vivo, indicating that cyanamide inhibits ALDH via a reactive species [DeMaster et al., Biochem. Biophys. Res. Com. 107:1333-1339 (1982)]. Cyanamide has been used for treating alcoholism but has not been approved in the U.S. Citrated calcium cyanamide is marketed in other countries as Temposil™, Dipsane™ and Abstem™, and plain cyanamide is marketed as Colme™ in Spain [See, U.S. Pat. No. 6,255,497].
Daidzin is a selective potent reversible inhibitor of ALDH-I, originally purified from an ancient Chinese herbal treatment for alcohol abuse. Its analogs include daidzein-7-O-[ω-carboxynonyl] ether (deczein), daidzein-7-O-[ω-carboxyhexyl] ether (hepzein), daidzein-7-O-[ω-carboxypentyl] ether (hexzein), daidzein, puerarin, and dicarboxymethyl-daidzein [Keung, Chemico - Bio. Int. 130-132:919-930 (2001)]. U.S. Pat. Nos. 5,204,369; 5,886,028; 6,121,010; and 6,255,497 describe methods for treating alcohol dependence or abuse using these compounds.
One of the major problems associated with therapies using ALDH inhibitors is ensuring patient compliance with the regimen. According to applicant's knowledge, there have been no teachings that suggest pharmacotherapies that adequately address this problem. For example, WO 99/21540 describes the administration of disulfiram in combination with compounds that bind to the D1 and/or D5 receptors and mimic dopamine to reduce craving for addictive substances in mammals. However, WO 99/21540 does not suggest pharmacotherapy for ensuring patient compliance with the regimen, which is important for the success of the treatment.
Another pharmacotherapy that has been suggested for treating alcoholism involves the inhibition of monoamine oxidases (MAOs). MAOs catalyze the oxidation of a variety of monoamines, including epinephrine, norepinephrine, serotonin and dopamine. MAOs are iron containing enzymes that exist as two isozymes A (MAOA) and B (MAOB). Various publications have described treatments for alcoholism using MAOB inhibitors [e.g., WO 92/21333, WO 96/37199]. WO 96/35425 discusses a treatment for alcoholism using a selective MAOB inhibitor in combination with a partial agonist of the 5-TH1A receptor. WO 00/71109 discusses a treatment for alcohol withdrawal symptoms using the MAOB inhibitor desmethylselegiline in combination with a second drug that treats alcohol withdrawal symptoms. U.S. Pat. No. 6,239,181 describes methods for alleviating symptoms associated with alcoholic neuropathy by administering the MAOB inhibitor, selegiline. However, none of the above references teach or suggest the use of MAOB inhibitors in therapies using ALDH inhibitors. Moreover, none of these references teach that MAOB inhibitors have a sustained effect on ensuring patient compliance with other therapies.
The present invention provides a solution for the deficiencies in traditional therapies using ALDH inhibitors to stop, prevent or reduce recidivism, thus, promoting compliance. The present invention also provides unexpectedly new and better compositions and methods for treating diseases that require the self-administration of an ALDH inhibitor.
SUMMARY OF THE INVENTION
The present invention provides compositions and methods for preventing, treating or reducing alcoholism comprising administering a therapeutically effective amount of an ALDH inhibitor in combination with an MAOB inhibitor.
There is provided in one embodiment of the present invention compositions and methods for increasing the rate of continuous abstinence, delaying resumption of abuse or dependence and/or preventing relapses in patients being treated for alcoholism.
There is further provided a method for increasing patient compliance with therapies that require self-administration of an ALDH inhibitor comprising the step of administering a therapeutically effective amount of a MAOB inhibitor.
According to one embodiment of the invention, the patient to be treated suffers from a disease requiring treatment with an ALDH inhibitor and consumes or can consume alcohol during therapy. The therapy does not involve forcing the patient to intake alcohol as part of the treatment. According to one preferred embodiment of this invention, the patient to be treated is suffering from alcoholism.
A composition according to the latter embodiment of the invention comprises an MAOB inhibitor and an ALDH inhibitor. The ALDH inhibitor may inhibit ALDH-I. The ALDH inhibitor may be, e.g., disulfiram, coprine, cyanamide, 1-aminocyclopropanol (ACP), daidzin, cephalosporins, antidiabetic sulfonyl ureas, metronidazole, or any of their metabolites or analogs exhibiting ALDH-inhibiting activity including, e.g., S-methyl N,N-diethyldithiocarbamate, S-methyl N,N-diethyldithiocarbamate sulfoxide, or S-methyl N,N-diethylthiocarbamate sulfoxide. In a more preferred embodiment, the ALDH inhibitor is disulfiram or an ALDH-inhibiting metabolite thereof. According to one preferred embodiment, the amount of disulfiram or an ALDH-inhibiting metabolite thereof administered is 500 mg per day.
In one embodiment, the MAOB inhibitor is, e.g., selegiline, pargyline, desmethylselegiline, rasagiline [R(+) N-propargyl-laminoindan], 3-N-phenylacetylamino-2,5-piperidinedione or caroxyazone. In a more preferred embodiment, the MAOB inhibitor is selegiline. According to one preferred embodiment, the amount of selegiline administered is 15 mg or less per day.
DETAILED DESCRIPTION OF THE INVENTION
An MAOB inhibitor according to this invention is a compound that inhibits MAOB but causes much less or no inhibition of MAOA activity, or a compound that selectively inhibits MAOB (e.g., within a particular dosage range). Hereinafter, the activity of an MAOB inhibitor as used according to this invention will be referred to as “selective MAOB inhibitor activity.”
In one embodiment, the MAOB inhibitor is selected from the group consisting of selegiline (Jumex®, Jumexal® Carbex®, Eldepryl®, Movergan®; Aptapryl®, Anipryl®; Eldeprine®; Plurimen®), desmethylselegiline, pargyline (Eudatin®, Supirdyl®, Eutonyl®) [U.S. Pat. No. 3,155,584], rasagiline [R(+)N-propargyl-laminoindan], 3-N-phenylacetylamino-2,5-piperidinedione, caroxyazone, AGN-1135 [WO 92/21333], MDL 72195 [WO 92/21333], J 508 [WO 92/21333], lazabemide [WO 00/45846], milacemide [WO 00/45846], IFO [WO 00/45846], mofegiline [WO 00/45846], and 5-(4-(4,4,4-trifluorobutoxy)phenyl)-3-(2-methoxyethyl)-1,3,4-oxadiazol-2(3H)-one [WO 00/45846]. In another embodiment, prodrugs or metabolites of the MAOB inhibitors are contemplated. Said metabolite should have substantially the same or better selective MAOB inhibitor activity as its unmetabolized form.
A prodrug of a MAOB inhibitor is a derivatized MAOB inhibitor that is metabolized in vivo into the active inhibitory agent. Prodrugs according to this invention preferably have substantially the same or better therapeutic value than the underivatized MAOB inhibitor. For example, a prodrug useful according to this invention can improve the penetration of the drug across biological membranes leading to improved drug absorption; prolong duration of the action of the drug, e.g., slow release of the parent drug from the prodrug and/or decrease first-pass metabolism of the drug; target the drug action; improve aqueous solubility and stability of the drug (e.g., intravenous preparations, eyebrows etc.); improve topical drug delivery (e.g., dermal and ocular drug delivery); improve the chemical and/or enzymatic stability of drugs (e.g., peptides); or decrease side effects due to the drug. Methods for making prodrugs are readily known in the art.
The term “MAOB inhibitor” according to this invention or metabolite thereof, as used herein includes pharmaceutically acceptable salts of those compounds. Pharmaceutically acceptable salts of MAOB inhibitors useful according to the methods of this invention are salts prepared from pharmaceutically acceptable reagents. In one embodiment, said pharmaceutically acceptable salt is a hydrochloride salt.
Methods known in the art for evaluating the activity of MAOB and MAOA can be used for selecting MAOB inhibitors according to this invention. For example, blood samples can be drawn to determine platelet MAO activity using radiolabelled benzylamine or phenylethylamine. (i.e., evaluating MAOB inhibitory activity). [Murphy, D. L., et al., Psychopharm. 62:129-132 (1979); Murphy, D. L., et al., Biochem. Med. 16:254-265 (1976); all incorporated by reference herein] In one embodiment, MAOB activity is decreased greater than 80% compared to MAOB enzyme activity before treatment. In a preferred embodiment, MAOB activity is decreased greater than 90% or 95% compared to MAOB activity before treatment.
MAOA inhibitory activity can, for example, be evaluated by measuring levels of 3-methoxy-4-hydroxyphenylglycol (MHPG) or 5-hydroxyindoleacetic acid (5-HIAA) in the plasma of blood or in cerebral spinal fluid (CSF) by using gas chromatography-mass spectroscopy (gc-ms). [Murphy, D. L., et al., Clinical Pharmacology in Psychiatry, 3rd Series., Eds. Dahl, Gram, Paul, and Potter, Springer-Verlag: 1987; Major, L. F., et al., J. Neurochem. 39:229-231 (1979); Jimerson, D. C., et al., Biomed. Mass. Spectrom. 8:256-259 (1981); all incorporated by reference herein]. In one embodiment, after administration of the MAOB inhibitor, plasma MHPG levels should not be reduced lower than 45% of pretreatment levels of plasma MHPG. In a preferred embodiment, after administration of the MAOB inhibitor, plasma MHPG or CSF 5-HIAA levels should not be reduced more than 80% of pretreatment levels of MHPG or 5-HIAA levels, respectively.
ALDH inhibitors according to the invention are compounds that are capable of inhibiting the activity of one or more of the several isozymes of ALDH, e.g., ALDH-I and ALDH-IL. According to one embodiment, the ALDH is involved in alcohol metabolism. ALDH inhibitors according to this invention include, e.g., disulfiram, coprine, cyanamide, I-aminocyclopropanol (ACP), daidzin, cephalosporins, antidiabetic sulfonyl ureas, metronidazole, and any of their metabolites or analogs exhibiting ALDH-inhibiting activity. In another embodiment, the ALDH inhibitor is disulfiram or an ALDH-inhibiting metabolite thereof. Such metabolites include, e.g., S-methyl N,N-diethyldithiocarbamate, S-methyl N,N-diethyldithiocarbamate sulfoxide, and S-methyl N,N-diethylthiocarbamate sulfoxide.
The term “ALDH inhibitor” according to the invention or metabolite thereof, as used herein, includes pharmaceutically acceptable salts of those compounds.
The term “alcoholism” according to the invention includes alcohol abuse and alcohol dependence as described below.
The term “alcohol abuse” is defined in the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV). Alcohol abuse as a maladaptive pattern of alcohol use that leads to clinically significant impairment or distress. Symptoms include one or more of the following occurring within a 12-month period: (1) recurrent alcohol use that results in a failure to fulfill major role obligations at work, school or home; (2) recurrent alcohol use in physically hazardous situations; (3) recurrent alcohol-related legal problems; and (4) continued alcohol use despite having persistent or recurrent social or interpersonal problems caused or exacerbated by the effects of the substance [McRae et al., supra; Swift, R. M., supra; Kick, S., supra].
Alcohol dependence occurs when symptoms of abuse are accompanied by three or more of the following: (1) tolerance defined by either: (a) a need for markedly increased amounts of alcohol to achieve intoxication or desired effect, or (b) markedly diminished effect with continued use of the same amount of alcohol; (2) withdrawal manifested by either: (a) characteristic withdrawal syndrome for alcohol or (b) alcohol taken to relieve or avoid withdrawal symptoms; (3) alcohol taken in larger amounts over a longer period than as intended; (4) a persistent desire or unsuccessful efforts to reduce or control drinking; (5) much time spent in activities necessary to obtain alcohol, use alcohol, or recover from its effects; (6) important social, occupational, or recreational activities being given up or reduced because of drinking; and (7) continued use despite knowledge of having a persistent or recurrent physical or psychological problem caused or exacerbated by alcohol [McRae et al., supra; Swift, R. M., supra; Kick, S., supra].
Alcohol abuse or dependence can also result in other symptoms including dyspepsia or epigastric pain, headache, diarrhea, difficulty in sleeping, fatigue, unexplained weight loss, apparent malnutrition, easy bruising, increased mean corpuscular volume, elevated transaminase levels (especially an aspartate transaminase level greater than of alanine transaminase), elevated γ-glutamyl transferase levels, iron-deficiency anemia, hepatomegaly, jaundice, spider angiomata, ascites, and peripheral edema. Behavioral symptoms associated with alcohol abuse or dependence include absenteeism from work or school, increasing irritability, difficulties with relationships, verbal or physical abuse, and depression [McRae et al., supra; Swift, R. M., supra; Kick, S., supra].
Alcoholism is often diagnosed using questionnaires, known to those of ordinary skill in the art, which are structured to obtain information related to the symptoms of alcohol abuse and/or dependence as outlined by the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV). The most commonly used screening test used for detecting alcohol abuse or dependence is the CAGE questionnaire [Kick, S., supra]. Alcoholics Anonymous describes another questionnaire.
A patient to be treated for, or protected against, the onset of alcoholism according to this invention can be a human, including children and adults, who are susceptible to or are suffering from alcoholism or who are being treated for alcoholism and are susceptible to experiencing relapses. A patient who is having difficulty complying with, or is being induced to comply with, treatments using ALDH inhibitors or their active metabolites according to this invention can be a human, including children and adults.
Compositions according the present invention comprise a pharmaceutically acceptable carrier together with an ALDH inhibitor and an MAOB inhibitor. According to one embodiment, the ALDH inhibitor is disulfiram, or a metabolite or prodrug thereof. According to another embodiment, the composition comprises 500 mg, 250 mg, 125 mg, or 60 mg of disulfiram, or metabolite or prodrug thereof. According to yet another embodiment, the MAOB inhibitor is selegiline, or a metabolite or prodrug thereof. According to a further embodiment, the composition comprises 15 mg or less of selegiline, or metabolite or prodrug thereof.
In a preferred embodiment, the composition comprises 500 mg, 250 mg, 125 mg or 60 mg of disulfiram, or metabolite or prodrug thereof, and 15 mg or less of selegiline, or metabolite or prodrug thereof. In a more preferred embodiment, the composition comprises about 60 mg of disulfiram, or a metabolite or prodrug thereof, and about 2 mg of selegiline, or a metabolite or prodrug thereof.
The effective dosage of a composition of the invention administered to a patient is at least an amount required to minimize, reduce or eliminate one or more symptoms associated with preventing or treating alcoholism, typically one of the symptoms discussed above. The magnitude of a prophylactic or therapeutic dose of the composition of the invention in the treatment of a patient will vary with the symptoms being exhibited, the severity of the patient's affliction, the desired degree of therapeutic response, the route of administration, and the concomitant therapies being administered. The dose and dose frequency will also vary according to the age, weight and response of the individual patient. Generally, however, treatment for alcoholism will be ongoing, although the intensity of treatment can vary depending on the patient's condition and exposure to biochemical and environmental stimuli that can warrant a variation on the treatment. Dosages can be administered in a single or multiple dosage regimen.
According to one preferred embodiment of the invention, the composition comprising 500 mg, 250 mg, 125 mg or 60 mg of disulfiram and 15 mg or less selegiline is administered twice a day, in the morning and at noon or late afternoon. In another preferred embodiment, a composition comprising about 125 mg of disulfiram and about 5 mg of selegiline is administered twice a day, in the morning and at noon or late afternoon.
Selegiline can be administered twice a day, in the morning and at noon or late afternoon. An initial daily non-oral dose can be at least about 0.01 mg per kg of body weight, calculated on the basis of the free secondary amine, with progressively higher doses being employed depending upon the response to therapy. The final daily dose can be between about 0.05 mg/kg of body weight to about 0.15 mg/kg of body weight (all such doses being calculated in the basis of the free secondary amine).
The present invention when employing selegiline is not limited to a particular form of selegiline and the drug can be used either as a free base or as a pharmaceutically acceptable acid addition salt. In the latter case, the hydrochloride salt is preferred. However, other salts useful in the invention include those derived from organic and inorganic acids such as, without limitation, hydrobromic acid, phosphoric acid, sulfuric acid, methane sulfonic acid, acetic acid, tartaric acid, lactic acid, succinic acid, citric acid, malic acid, maleic acid, aconitic acid, salicylic acid, thalic acid, embonic acid, enanthic acid, and the like.
The treating physician will know how to increase, decrease or interrupt treatment based upon the patient's response. Improvement for alcoholics or potentially relapsing alcoholics can be assessed by observing increased abstinence from consuming alcohol by the patient, following the methods of this invention, as compared to patients where therapy did not comprise the co-administration of a MAOB inhibitor. Improvement in compliance with self-administering ALDH inhibitors can be assessed by observing the increased duration over which patients, following the methods of this invention, take the ALDH inhibitor as compared to patients whose therapy did not comprise the co-administration of an MAOB inhibitor.
Any suitable route of administration can be employed for providing the patient with an effective dosage of a composition of this invention. For example, oral, peroral, buccal, nasal, pulmonary, vaginal, lingual, sublingual, rectal, parenteral, transdermal, intraocular, intravenous, intraarterial, intracardial intramuscular, intraperitoneal, intracutaneous, subcutaneous, sublingual, intranasal, intramuscular, and intrathecal administration and the like can be employed as appropriate. The term parenteral as used herein includes subcutaneous, intracutaneous, intravenous, intramuscular, intra-articular, intrasynovial, intrasternal, intrathecal, intralesional and intracranial injection or infusion techniques. According to one preferred aspect of this invention, the route of administration is the oral route.
The composition can be conveniently presented in unit dosage form and prepared by any of the methods well-known in the art of pharmacy. Dosage forms can include tablets, scored tablets, coated tablets, pills, caplets, capsules (e.g., hard gelatin capsules), troches, dragees, powders, aerosols, suppositories, parenterals, dispersions, suspensions, solutions, transdermal patches and the like, including sustained release formulations well known in the art. In one preferred embodiment, the dosage form is a scored tablet or a transdermal patch. U.S. Pat. No. 5,192,550, incorporated herein by reference, describes a dosage form for selegiline comprising an outer wall with one or more pores, in which the wall is impermeable to selegiline but permeable to external fluids. This dosage form can have applicability for oral, sublingual or buccal administration.
The compositions of this invention can be orally administered in any orally acceptable dosage form including, but not limited to, capsules, tablets, and aqueous suspensions and solutions. In the case of tablets for oral use, carriers which are commonly used include lactose and corn starch. Lubricating agents, such as magnesium stearate, are also typically added. For oral administration in a capsule form, useful diluents include lactose and dried corn starch. When aqueous suspensions are administered orally, the active ingredient (i.e., ALDH inhibitor and/or MAOB inhibitor) is combined with emulsifying and suspending agents. If desired, certain sweetening and/or flavoring and/or coloring agents can be added.
The compositions according to this invention can be in the form of a sterile injectable preparation, for example, as a sterile injectable aqueous or oleaginous suspension. This suspension can be formulated according to techniques known in the art using suitable dispersing or wetting agents (such as, for example, Tween 80) and suspending agents. The sterile injectable preparation can also be a sterile injectable solution or suspension in a non-toxic parenterally-acceptable diluent or solvent, for example, as a solution in 1,3-butanediol. Among the acceptable vehicles and solvents that can be employed are mannitol, water, Ringer's solution and isotonic sodium chloride solution. In addition, sterile, fixed oils are conventionally employed as a solvent or suspending medium. For this purpose, any bland fixed oil can be employed including synthetic mono- or diglycerides. Fatty acids, such as oleic acid and its glyceride derivatives are useful in the preparation of injectables, as are natural pharmaceutically-acceptable oils, such as olive oil or castor oil, especially in their polyoxyethylated versions. These oil solutions or suspensions can also contain a long-chain alcohol diluent or dispersant such as Ph. Helv or a similar alcohol.
Methods for making transdermal patches including selegiline transdermal patches have been described in the art. [See e.g., U.S. Pat. Nos. 4,861,800; 4,868,218; 5,128,145; 5,190,763; and 5,242,950; and EP-A 404807, EP-A 509761, EP-A 593807, and EP-A 5509761, all of which are incorporated by reference herein.]
Compositions of this invention can also be administered in the form of suppositories for rectal administration. These compositions can be prepared by mixing a compound of this invention with a suitable non-irritating excipient which is solid at room temperature but liquid at the rectal temperature and therefore will melt in the rectum to release the active components. Such materials include, but are not limited to, cocoa butter, beeswax and polyethylene glycols.
The compositions of this invention can be administered by nasal aerosol or inhalation. Such compositions are prepared according to techniques well-known in the art of pharmaceutical formulation and can be prepared as solutions in saline, employing benzyl alcohol or other suitable preservatives, absorption promoters to enhance bioavailability, fluorocarbons, and/or other solubilizing or dispersing agents known in the art.
Patients can be regularly evaluated by physicians, e.g., once a week, to determine whether there has been an improvement in symptoms and whether the dosage of the composition of the invention needs to be adjusted.
According to the methods of this invention, the MAOB inhibitor can be included in the composition comprising the ALDH inhibitor. Alternatively, the MAOB inhibitor can be administered simultaneously with the composition comprising the ALDH inhibitor, or at any time during the treatment of the patient with the ALDH inhibitor.
The various terms described above such as “therapeutically effective amount,” are encompassed by the above-described dosage amounts and dose frequency schedule. Generally, a therapeutically effective amount of an MAOB inhibitor is that amount at which MAOB is inhibited but MAOA exhibits slight or no reduction in activity in the patient. Slight reduction in activity preferably comprises less than about 30% reduction in activity, more preferably less than about 20% reduction in activity, and yet more preferably less than about 10% reduction in activity. In one embodiment, the dosage of selegiline is an amount equal to or less than 15 mg per day. In another embodiment, the dosage of pargyline is equal to or less than 30 mg/day.
Throughout this specification, the word “comprise” or variations such as “comprises” or “comprising” will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.
STATEMENT REGARDING PREFERRED EMBODIMENTS
While the invention has been described with respect to preferred embodiments, those skilled in the art will readily appreciate that various changes and/or modifications can be made to the invention without departing from the spirit or scope of the invention as defined by the appended claims. All documents cited herein are incorporated in their entirety herein.
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Compositions and methods for treating, preventing, or reducing alcoholism, in particular methods for increasing patient compliance with therapies that require the intake of an ALDH inhibitor comprising the step of administering a monoamine oxidase B inhibitor.
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BACKGROUND OF THE INVENTION
The present invention relates to a method of manufacturing a multi-layers type solid-state image sensor obtained by stacking a photoconductive film on a substrate provided with solid-state image sensor.
A two-layered solid-state image sensor obtained by stacking a photoconductive film on a solid-state image sensor substrate has good characteristics of high sensitivity and low level of image smear. Thus, the solid-state image sensor of this type is promising for use in cameras of various types of TV monitors or high-definition TVs. An amorphous silicon film is often used as a photoconductive film for a solid-state image sensor of this type, and a silane glow discharge decomposition method is generally used as a method of depositing the amorphous film (e.g., refer to N. Harada et al. IEEE Trans. Electron Devices Vol. ED-32, No. 8 (1985) p. 1499).
However, a method of manufacturing a two-layered image sensor by the amorphous silicon film deposition method using the glow discharge decomposition method has the following problems. More specifically, since this method uses plasma for decomposing a source gas, many charged particles are present in a gas phase and damage the obtained film, thus degrading the characteristics of the film. As a result, in a solid-state image sensor which uses an amorphous silicon film as a photoelectric conversion layer, the image lag characteristics resulting from the amorphous silicon film are degraded due to the degradation in the quality of the amorphous silicon film or the interface characteristics.
Assume that a structure wherein a p-type amorphous silicon carbon film is provided as a barrier layer on an i-type amorphous silicon film, i.e., a p-type a-SiC/i-type a-Si structure is adopted as the structure of the photoconductive film having an amorphous silicon film. When such a structure is formed by the glow discharge decomposition method, the interface characteristics between the films of the composite film comprising the p-type a-SiC/i-type a-Si structure are degraded. As a result, recombination of electrons and holes generated by light incidence tends to occur at the interface, and the sensitivity in a blue region which is absorbed in the vicinity of the surface is decreased.
In order to solve such a problem of interface characteristics, a method to include a graded region, wherein the carbon content is continuously changed, in the a-SiC/a-Si interface is also proposed. However, this method makes the process control difficult and eventually degrades the image-lag characteristics.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a method of manufacturing a multi-layers type solid-state image sensor which has good image lag characteristics and in which the sensitivity of the blue region may not be degraded even if a p-type SiC/a-Si photoconductive film is used.
The present invention is characterized in that, in a method of manufacturing a solid-state image sensor for stacking an amorphous Si (a-Si) film as a photoconductive film, the a-Si film is deposited by a photochemical vapor deposition method.
According to the method of the present invention, since the a-Si film is deposited with only a radical reaction wherein no charged particles are present in a gas phase, damage is small and film quality and interface characteristics are improved. As a result, the image lag characteristics resulting from the photoconductive film are improved. In particular, when a p-type a-SiC/i-type a-Si structure is employed, its interface characteristics are improved, thereby increasing the sensitivity in the blue region.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view of a CCD image sensor manufactured by a method according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of an a-Si film depositing apparatus used in the embodiment;
FIG. 3 shows a graph indicating the result obtained by measuring the relationship between the a-Si film characteristics and substrate temperatures; and
FIG. 4 shows a graph indicating the relationship between the silane fraction in a source gas and the deposition rate of amorphous silicon.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a sectional view of a multi-layers type solid-state image sensor manufactured by a method according to an embodiment of the present invention. A plurality of n + -type layers 2 are formed in p well/p + silicon crystalline substrate 1. As a result, a plurality of diodes for storing signal charges are formed in a matrix manner by substrate 1 and n + -type layers 2. Vertical CCDs 3 each comprising an n + -type buried channel CCD are formed in substrate 1 adjacent to the rows of the storing diodes. Reference numeral 4 denotes a p + -type layer as a channel stopper. A set of a storing diode row and a vertical CCD of the same structure is repeatedly formed and the sets are separated by p + -type layers 4. Reference numerals 5a and 5b denote transfer gate electrodes of vertical CCD 3. Parts of electrodes 5a serve as the charge transfer gate electrodes from layer 2 of the storing diode to the CCD channel. First interlayer insulating film 6 made of silicon dioxide is formed on substrate 1 to cover electrodes 5a and 5b. A contact hole corresponding to the storing diode is formed through insulating film 6. First electrode 7 is formed in the contact hole and the periphery of the contact hole on film 6. Electrode 7 is independently arranged for each pixel. First electrode 7 is formed by an Al-Si film, an n + -type polycrystalline silicon film, or the like. Second interlayer insulating film 8 of polyimide, PSG, BPSG, or the like is formed on first interlayer insulating film 6 and first electrode 7 in order to compensate for the gap therebetween. Second electrode 9 independent for each pixel is formed on second film 8 so as to contact first electrode 7 through a hole formed on film 8. Second electrode 9 is formed by, e.g., an Al-Si, Ti, Mo, Cr, or n + -type polycrystalline silicon film, or the like. In this manner, CCD image sensor substrate 10 is formed.
Amorphous silicon (a-Si) photoconductive layer 11 is deposited on the surface of CCD image sensor substrate 10, and transparent electrode 12 made of indium-tin-oxide (ITO) or the like is formed thereon, thereby constituting a multi-layer type CCD image sensor. In this embodiment, photoconductive layer 11 consists of three layers of i-type a-SiC film 13, i-type a-Si film 14, and p-type a-SiC film 15 deposited in this order from the substrate side.
A practical method for depositing three-layered a-Si photoconductive layer 11 by a photochemical vapor deposition method according to the embodiment of the present invention will be described.
FIG. 2 shows a schematic arrangement of a photochemical vapor deposition apparatus (J. Appl. Phys. 58(a), 1 Nov. 1985) used in this method. This arrangement will be described. Referring to FIG. 2, reference numeral 16 denotes a film depositing chamber. Sample table 18 for placing CCD image sensor substrate 10 as a sample is housed in chamber 16. Heater 19 for heating the sample is provided inside table 18. Lamp housing 20 is provided on chamber 16. Light source 21 comprising, e.g., a plurality of low-pressure mercury lamps, and reflecting plate 22 for reflecting the light from light source 21 toward substrate 10 are provided in housing 20. Inert gas line 23 is connected to housing 20 and purges in the housing 20 with an inert gas. Light-transmitting window 24 is formed in a partition wall between chamber 16 and housing 20, and light from light source 21 radiates sample substrate 10 through it. Gas source 25 is connected to chamber 16 through a pipe, and a source gas is supplied from it to chamber 16. Evacuation pump 26 is connected to chamber 16 to evacuate in the chamber 16.
A method for depositing a-Si photoconductive film 11 by using the above film depositing apparatus and a pre-treatment of the substrate by using atomic hydrogen which is performed prior to the film formation, will be described.
Substrate 10 is placed on sample table 18. Heater 19 is turned on to keep substrate 10 at about 200° C. In this state, a hydrogen gas of about 10 sccm containing a small amount of mercury is introduced in film depositing chamber 16 from gas source 25, and the interior of chamber 16 is kept at a gas pressure of about 0.3 Torr. The gas flow rate is preferably set within a range of 1 and 100 sccm. And the gas pressure is preferably set within a range of 0.1 to 10 Torr. Light source 21 is turned on to irradiate the upper surface of substrate 10 with ultraviolet light for about 30 minutes, thereby performing atomic hydrogen treatment of the upper surface. The atomic hydrogen treatment time is preferably set within a range of 5 and 100 minutes. In the pre-treatment using such a mercury-sensitizing method, since the resonance lines of the low-pressure mercury lamp are 185 nm and 254 nm, when the hydrogen gas is allowed to photochemically react with such a low energy, the hydrogen gas is not ionized. Therefore, unlike in RF or DC glow discharge, the substrate is not sputtered by H + , H 2 + , or the like. As a result, the insulating film on the surface of the solid-state image sensor substrate will not be sputtered to attach to the surface of a pixel electrode, or may not be included as a contaminant in a photoconductive film which is later formed, and a clean pixel electrode surface reduced by the atomic hydrogen can be obtained.
After pre-treatment is performed in the above manner, film depositing chamber 16 is evacuated to about 10 -6 Torr, monosilane (SiH 4 ) and acetylene (C 2 H 2 ) gases as source gases, mercury vapor, and a helium (He) gas as a dilution gas are introduced in film depositing chamber 16, and the pressure in chamber 16 is set to about 1 Torr. Subsequently, sample substrate 10 is heated to about 200° C., and light source 21 comprising low-pressure mercury lamps is turned on to irradiate the surface of sample substrate 10 with ultraviolet light having wavelengths of 254 nm and 185 nm. As a result, the source gas is photochemically dissociated and i-type a-SiC film 13 is deposited. This step is not always necessary but a next step can be directly performed on the substrate.
Film forming chamber 16 is evacuated to about 10 -6 Torr, and a monosilane gas, as a source gas, and mercury vapor are introduced to chamber 16 at about 0.3 Torr. Low-pressure mercury lamp 21 is turned on for about two hours, thereby depositing i-type a-Si film 14 on i-type a-SiC film 13 (or on substrate 10 when film 13 is not deposited) to a thickness of about 1 to 3 μm. Finally, monosilane and acetylene gases as the source gases, a diborane (B 2 H 6 ) gas as the doping gas, a helium gas as the dilution gas, and mercury vapor are introduced into chamber 16 at a pressure of 1 Torr, and light source 21 is turned on for about 1 to 2 minutes, thereby depositing p-type a-SiC film 15 on i-type a-Si film 14 to a thickness of about 100 to 200 Å by the photochemical vapor deposition method.
When the photoconductive image lag of the CCD image sensor device manufactured by this embodiment, in which a-Si photoconductive layer 11 is deposited, was measured, it was about 1.0% after 3 fields. When a similar layered structure is formed by a conventional glow discharge decomposition method, the photoconductive image lag after 3 fields is 5 to 10%. In contrast to this, according to this embodiment, the photoconductive image lag is greatly reduced to about 1/5 or less. The blue sensitivity was increased to about 1.5 times at a wavelength of 450 nm compared to a case when a glow discharge decomposition method was utilized, and was thus greatly improved.
In a-Si photoconductive layer 11 shown in FIG. 1, when the density of states and Si dangling bond density of, in particular, i-type a-Si film 14, are large, the photoconductive image lag is increased. FIG. 3 shows results obtained when the substrate temperature dependencies of the Si dangling bond density (Ns) and the minimum value (Nmin) of the density of states near the Fermi-levo, of an i-type a-Si film (film thickness of about 1 μm) deposited by the photochemical vapor deposition method described above were measured. The respective densities were measured by an electron spin resonance (ESR) method and a space charge limited current (SCLC) method. The results show that, in the substrate temperature range of 100° to 350° C., Ns and Nmin are 2×10 17 /cm 3 or less and 5×10 16 /cm 3 ·eV or less, respectively, and a good film is formed. Excluding this range both Ns and Nmin are greatly increased. Therefore, when an i-type a-Si film is formed in the present invention by using the photochemical vapor deposition method, the substrate temperature is preferably set within a range of 100° and 350° C., more preferably 150° and 300° C., and most preferably 170° and 270° C.
In the present invention, the pressure in the film depositing chamber when the a-Si photoconductive layer is deposited by the photochemical vapor deposition method is preferably set within the range of 1×10 -2 and 10 Torr. When the pressure is less than 1×10 -2 , the film deposition rate is greatly decreased since the source gas concentration is decreased. When the pressure is more than 10 Torr, the film tends to attach to the light-transmitting window, thereby greatly decreasing the deposition rate. The concentration of silicon compounds in the source gas in this case is preferably 60% or more in order to increase the deposition rate of the amorphous silicon. When the thickness of the a-Si photoconductive layer is decreased, its capacitance is increased, and the capacitive image lag is increased. For this reason, the film thickness of the a-Si photoconductive layer must be 1 μm or more and preferably 2 μm or more. When this point is considered, a pressure for providing a sufficiently high deposition rate must be selected. If the thickness of the a-Si photoconductive layer is too large, the image lag characteristics are degraded. Therefore, the film thickness is preferably 10 μm or less.
The present invention is not limited to the above embodiment. For example, when a disilane (Si 2 H 6 ) gas is used as the main source gas and a low-pressure mercury lamp emitting light having a wavelength of, e.g., 1849 Å is used, an a-Si photoconductive layer can be deposited by the photochemical vapor deposition method and not by the mercury-sensitized method. Light from a rare gas (Xe, Kr, Ar, and so on) or hydrogen microwave discharge can be used as the light source, and monosilane or disilane can be used as the source gas, thereby depositing an a-Si photoconductive layer by the photochemical vapor deposition method. In the photochemical vapor deposition method, a deuterium lamp or ultraviolet laser can be used as the light source. The conditions such as the source gas flow rate or the mercury vapor saturator temperature can be arbitrarily set in accordance with the required film thickness and film quality.
A CCD image sensor substrate is used in the above embodiment. However, the present invention can be similarly applied when an a-Si photoconductive layer is formed on an MOS or BBD image sensor substrate. The structure of the a-Si photoconductive layer is not limited to that of the embodiment. For example, an i-type a-Si/p-type SiC layered structure can be used.
Various changes and modifications can be made within the spirit and scope of the invention.
As described above, according to the present invention, an a-Si photoconductive layer of a layered type solid-state image sensor is formed on a substrate by a photochemical vapor deposition method. Therefore, the film quality and the interface characteristics of the photoconductive layer are improved, and the image lag resulting from the photoconductive layer can be greatly reduced compared to a conventional case.
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A method of manufacturing a solid-state image sensor comprises the steps of preparing a solid-state image sensor substrate in which a signal charge storing diode and a signal charge readout section are formed and forming, as a photoelectric conversion section, a photoconductive film having an amorphous silicon film on the substrate. The amorphous silicon film is formed by introducing a source gas containing silicon compounds on the substrate and decomposing the source gas by radiating ultraviolet light on the source gas while the solid-state image sensor substrate is kept at a temperature of 100° to 350° C.
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CROSS-REFERENCE TO RELATED APPLICATIONS
The present application is claiming priority of U.S. Provisional Patent Application Ser. No. 60/526,548, entitled “System and Method for the Safe Automatic Detection of a Field Device Communicating With Current Modulated Signal” filed on Dec. 4, 2003, the content of which is incorporated by reference herein.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present disclosure relates to the sensing and configuration of devices, and more particularly, to the sensing and configuration of devices through the use of a reduced current.
2. Description of the Related Art
A number of protocol specifications, like the HART® (Registered Trademark of the HART Communications Foundation) communication protocol, are designed to support digital communications. These digital communications can be used for the measurement of various processes and parameters of various control devices. These digital communications, within these protocol specifications, typically occur over a traditional range of 4-20 milliAmps (mA). Generally, these digital communications provide host control systems with process and diagnostic information associated with a field device. The digital communications can occur as the host control system monitors and controls an industrial process.
One purpose of such protocol specifications is to establish standards so that “hosts” {or “input/output (I/O) masters”} can communicate with field “devices” (“slaves”) developed by different vendors. One subset of the protocol specifications is classified as having “common functions.” “Common functions” requires that the host or device have to meet all standards within this subset of protocol specifications. This allows the host to require only a single interface layer to support a variety of field devices from many different vendors.
However, other components of the protocol specification are classified as “device-specific,” and are defined by the individual device manufacturer. Since at least some of the digital data that will be passed between a host or I/O Master and the field device is specific to the given field device type, it is important to know what kind of field device is connected to the host control system prior to using the field device within an industrial process in real-time.
In other words, due to the nature of device-specific components of field devices, it is necessary to obtain and verify pertinent information regarding the identification of the field device prior to configuration load and execution. Generally, configuration load and execution can be defined as the initialization of the field device for use in the field, and the actual employment of the field device. Pertinent information can include a unique identifier for a given field device, the vendor name for the field device, the firmware revision installed in the field device, the tag name (that is, the pseudonym) for the field device, description of the field device, and the various range limits that the field device can measure or apply. Without the above information derived from the initial start-up of a field device, it is difficult to integrate device specific data into a real-time process control strategy.
Typically, input devices are current sourcing type, and output devices are a current sinking type. A sensor is an example of an input device and a valve is an example of an output device. Employment of a “base signal” of the sourcing current provides at least two functions. It provides the power to charge up, and initially configure, the field devices, and the base signal also is the carrier over which digital information is conveyed. For a current sinking device, the I/O master should drive the current for providing the “base” signal associated with these protocols. Therefore, for output devices, the host or I/O master provides a minimal specified current in order for the digital communication, with aid of the protocol specifications, to function.
Conventional protocol specifications required users to initially load a control configuration (perhaps with the use of wrong initial control configuration), activate the control strategy, and drive the output (sourcing) current to a base amount required for communication with the field device. This occurred over a traditional range of 4-20 mA. Only then could the actual device identification and configuration data be collected. However, as can be appreciated, this could lead to significant errors in implementing an initial real-time control strategy.
An alternative approach, used in other conventional protocol specifications, was to always provide a minimal current of 4 mA. However, this approach is not acceptable, as it is unsafe to power up a field device that is not initially configured. In any event, a user would have no control of the output devices if a problem would cause the field device to render itself unresponsive to the current.
In conventional technologies, to run field devices, current is applied to the field device after configuration, as after configuration it is controllable. However, during a 4 mA power up to the field device, current is applied even without any configuration, and therefore is no way to control the field device. However, if anything goes wrong after applying the 4 mA current, there is no way to control the field device. Another issue is that in this prior art scenario, the minimal current will be omnipresent, which can create safety problems.
Therefore, there is a need to safely and securely establish communication with a field device and acquire the field device identification data using a current modulated signaling technique, prior to a configuration load.
SUMMARY OF THE INVENTION
There is a provided a current generator that provides a first current level to read a configuration parameter of at least one field device. The first current level is lower in amperage than a second current level. The first current level does not operate the field device. The current generator also provides the second current. The second current level operates said field device. A current sensor is connected in circuit with the field device. The current sensor detects the configuration parameter(s) associated with the first current level.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is diagram of a prior-art control system before configuration;
FIG. 2 is diagram of a prior-art configuration of a system controller and a master in an inactive status;
FIG. 3 is a diagram of a prior-art configuration of a system controller and a master in an active status;
FIG. 4 is a diagram of a prior-art configuration of a configured system controller and master.
FIG. 5 is diagram of a configuration of devices with employment of an “auto-detect” option;
FIG. 6 is a diagram of a computer system in which a program for detecting configuration information of field devices could operate; and
FIG. 7 is a diagram of a current generator that operates in a detection/filed device configuration reading mode and a field device operation mode.
DESCRIPTION OF THE INVENTION
The term “module” is used herein to demarcate a functional operation that may be embodied either as a stand-alone component or as one of a plurality of modules in an integrated assembly.
Referring to FIG. 1 , illustrated is a prior-art unconfigured system 100 having an inactive system controller 110 and an inactive I/O master 120 and one or more field devices 125 . Coupled between inactive system controller 110 and inactive I/O master 120 is a control connection 115 . Control connection 115 is unpowered, and inactive system controller 110 and inactive I/O master 120 are not configured. Therefore there is no current to field devices 125 . Furthermore, no configuration information has been retrieved from the one or more field devices 125 .
The inactive system controller 110 represents an apparatus device, hardware, software or both, that can execute control algorithms which are used to control one or more field devices 125 .
In one embodiment, one example of an inactive system controller 110 is a C200 module in an Experion Process Knowledge System™ (PKS). Experion PKS is an integrated platform for which controls, manages and seeks to optimize process operations, diagnostics and domain knowledge. C200 is a device that is employed to control process operations, such as in Experion PKS.
Turning now to FIG. 2 , illustrated is a prior-art initially configured system 129 including an inactive system controller 130 with inactive control blocks 131 and an inactive I/O master 140 with inactive channel blocks 141 and one or more field devices 145 . Coupled between inactive system controller 130 and inactive I/O master 140 is a control connection 135 . Control connection 135 conveys information between the inactive system controller 130 and inactive I/O master 140 .
Inactive system controller 130 is illustrated as having one or more inactive control blocks 131 . Control blocks are the logical representations of real time control algorithms/strategies, such as a “Proportional-Integral-Derivative” control algorithm for controlling and monitoring one or more field devices 145 . However, in inactive system controller 130 , the control blocks are inactive control blocks 131 . Therefore, although control blocks have been created, they are not yet being employed. Inactive control blocks 131 have been configured with initial/preexisting configuration data not derived from a direct reading of one or more field devices 145 .
Inactive I/O Master 140 is illustrated as having one or more inactive channel blocks 141 . Channel blocks are, generally, logical representations of data associated with one or more field devices 145 . Employment of channel blocks allows the device configurations to be integrated into control strategy. However, in initially configured system 129 , the control clocks are inactive control blocks 141 . Therefore, there is no current to one or more field devices 145 , and inactive control blocks 141 have been configured with initial/preexisting configuration data not derived from a direct reading of one or more field devices 145 .
Referring to FIG. 3 , illustrated is a prior-art initially configured system 149 that includes an active system controller 150 with active control blocks 151 , an active I/O master 160 with active channel blocks 161 , and one or more field devices 165 . Coupled between active system controller 150 and active I/O master 160 is a control connection 155 .
Active control blocks 151 have been loaded with an initial configuration. Control connection 155 is illustrated as an “Output Percent” of 0% to 100% (OP). OP is equivalent to output current 4 mA to 20 mA. When channel blocks are active and OP is 0%, 4 mA is driven to the current path 163 by the system and when it is 100%, 20 mA is driven. Active channel blocks 161 have also been loaded with the initial/pre-existing configuration parameters. Active channel blocks 161 of active I/O master 160 are actively interfacing with one or more field devices 165 over a current path 163 . Therefore, there is a 4-20 mA current sent to one or more field devices 165 . The 4-20 mA current powers one or more field devices 165 , but uses the parameters loaded within the initial configuration of active control blocks 151 and active channel blocks 161 to do so.
Referring to FIG. 4 , illustrated is a prior-art reconfigured system 169 illustrating the reconfiguration of a reconfigured system controller 170 , a reconfigured I/O master 180 after both have received updated actual configuration parameters from one or more field devices 185 over a current path 183 . A control connection 175 couples reconfigured system controller 170 and reconfigured I/O master 180 .
In reconfigured system 169 , after one or more field devices 185 are activated through application of the 4-20 mA current, the final identification/configuration data for each one or more field device 185 is retrieved from one or more field device 185 over current path 183 . The final configuration of reconfigured active control blocks 171 of reconfigured system controller 170 and reconfigured active channel blocks 181 of reconfigured I/O master 180 is, therefore, modified in accordance therewith with the discovered final one or more field device 185 reconfiguration information. In reconfigured system 169 , this can be digital information stored within one or more field devices 185 , conveyed over the 4-20 mA current over current path 183 .
Generally, as can seen from FIGS. 1-4 , the 4-20 mAs which is employed to power one or more field devices, is first driven in initial configuration of the active control blocks 151 and active channel blocks 161 . However, the actual digital configuration parameters of one or more field devices 185 are not read until after the current is applied, as illustrated in reconfigured system 169 . Therefore, the initial configurations of active control blocks 151 and active channel blocks 161 could be based upon erroneous information and parameters. Only after the initial system power up is completed in reconfigured system 169 are the actual configuration parameters associated with one or more field devices 185 taken into account within reconfigured system controller 170 and reconfigured I/O 180 . This can lead to serious errors in configuration, which can create safety or work concerns when employing a real-time control strategy that relies upon the accuracy of this initial configuration information.
One such problem is that when the initial configuration load is done and the devices are put into run state, a contact with the device has not yet been established. If there are some problems with the device, system 100 , 200 , 300 , or 400 will be able to detect only some time after a field device is in its run state. This could be catastrophic.
Turning now to FIG. 5 , illustrated is a configuration system 200 using a configuration detection feature for the digital information programmed in one or more field devices 250 . Generally, configuration system 200 employs a safe and a secure method to provide control system users with digital identification parameters prior to configuring the various system controllers and I/O masters. Configuration system 200 includes a system controller 205 , an I/O master 220 , and an auto-detector 240 that provides for the detection of actual digital configuration information from one or field devices 250 prior to applying the standard 4.0-20.0 mA of current. The actual configuration parameters that were originally digitally stored in one or more field devices 250 are then used in I/O master 220 or system controller 205 , as opposed to using user-defined configuration parameters. The choice of which one or more field devices 250 to detect can be displayed on and input in a system controller interface 223 or I/O master interface 225 .
By enabling auto-detection, a safe current, less than 4 mA, is driven through a current pathway 230 to one or more field devices 250 . The safe current, such as 3.2 mA, is adequate to power the device electronics of one or more field devices 250 to enable current modulated digital communication therewith. For instance, an application of 3.2 mA will not make a change in a state of one or more field devices 250 , such as a valve stem position, but will enable the reading of the actual digital configuration parameters of one or more field devices 250 . These parameters are then used to configure system controller 205 and I/O master 220 . Disabling auto-detector 240 will remove this safe current, thereby giving the user full control of the output current to one or more field devices 250 , even though the 3.2 mA current is within safe limits.
In other words, at 4 mA field devices 250 are just at the beginning of the normal operating range. By providing a current less than that, there will not be enough current to make any change in the one or more field devices 250 , other than just establishing the digital communication.
Generally, configuration system 200 provides a mechanism in I/O master 220 or system controller 205 , perhaps through employment of system controller interfaces 223 or I/O master interface 225 , to enable and disable automatic field device digital information detection for current sinking devices, such as one or more field devices 250 , before a control strategy or configuration is loaded to controller 205 and the I/O master 220 . Generally, when auto-detector 240 is enabled for one or more field devices 250 , I/O master 220 drives a “safe” current, such as of 3.2 mA, to one or more field devices 250 . This current is enough to power up most of one or more field devices 250 to establish digital communication. Generally, one reason a current such as 3.2 mA is safe is because it does not allow circuitry, such as valve circuitry, to operate on or within one or more field devices 250 . This current is below 4 mA, which is the 0% output value as per 4-20 mA current HART signal standards.
When auto-detector 240 is disabled, (the default setting) for any particular device 251 - 255 , pathway 230 to that particular devices is unpowered, providing drive zero current such that the digital configuration parameters for that particular device can not be read. When automatic device detection is enabled in the auto-detector 240 for any given one or more field devices 250 (or alternatively, all field devices) communication with one or more field devices 250 is established to collect device identification/configuration data from the one or more field devices 250 . The collected digital information/configuration parameters collected can then also presented to the user in system controller interface 223 or I/O master interface 225 which also provided the option to enable/disable automatic detection for each field devices of one or more field devices 250 .
After detection of one or more field devices 250 is complete, the digitally read and detected field device or field devices 250 can still be continuously monitored, using a low-priority polling scheme, as long as automatic device detection is enabled by auto-detector 240 . Any change in one or more field device 250 configuration is therefore automatically updated on system controller interface 223 or I/O master interface 225 mentioned above, and can be used in reconfiguring system controller 205 and/or I/O master 220 , respectively. This low-priority polling should have minor bandwidth loading on I/O master 220 . In one embodiment of configuration system 200 , if one or more field devices 250 are defective in some manner, system 200 removes minimal (less than 4.0 mA) current by disabling auto-detector 240 . Both using a smaller current than minimally required to drive one or more field devices 250 , such as 3.2 mA, and the capability of disabling auto-detector 240 enhance the safety of configuration system 200 .
The auto-detector 240 is disabled when a control strategy is loaded. This helps to avoid two separate controls for the output current of I/O master 220 being applied at the same time. Once the control strategy is loaded, current to one or more field devices 250 is controlled only though the control strategy.
In the case of redundant I/O masters (not illustrated), the auto-detector 240 feature will take effect only in the currently-designated primary I/O master 220 . However, the secondary I/O master will remember the user selections for each field device 250 and perform automatic device detection as soon as the secondary I/O master becomes a primary I/O Master following a switch-over. Finally, auto-detector 240 selection will not block the capability of I/O master 240 to shed outputs to a safe unpowered state in case of a failure.
In one embodiment, the loading of the control strategy does not disturb the current applied over current path 183 , nor does loading the control strategy overwrite the configuration data that was loaded to system controller 205 and I/O master 220 derived from one or more field devices 250 . An initial user configuration, that is, the configuration information that a user has before the actual reading of the digital information embedded in one or more field devices 250 can thus be validated by comparing it with actual device configuration data read from one or more field devices 250 . After the comparison is made and perhaps the initial user configuration is corrected, the collection of one or more field devices 250 dynamic data, that is, data that configuration system 200 collects through monitoring events in real time, can be started immediately without the need to go through an entire power up and reading of configuration readings and reconfiguration of system controller 205 and I/O master 220 at 4-20 mA.
In one embodiment, auto-detector 240 selection is fully supported by one or more redundant I/O masters. If auto-detector 240 is enabled in a primary I/O master, and if it fails over (switches over to the secondary), the new primary I/O master will preserve the auto-detector 240 selection. In configuration system 200 , if primary I/O master loses communication with the control system, outputs are then driven to some configured safe states. Unpowering, or removing the current, helps to ensure safe state configuration. The use of a safe current, such as 3.2 mA with auto-detector 240 does not obstruct this safety activity.
Referring to FIG. 6 , illustrated is a block diagram of a computer system 300 adapted for employment of auto-detector 240 and the reading of the digital configuration information embedded in one or more field devices 350 . Computer system 300 includes a workstation computer 310 with a storage media 325 and a user interface 305 coupled to workstation computer 310 . User interface 305 includes an input device, such as a keyboard or speech recognition subsystem, for enabling a user to communicate information and command selections to workstation computer 310 . A cursor control such as a mouse, track-ball, or joy stick, allows the user to manipulate a cursor on the display for communicating additional information and command selections to workstation computer 310 . Computer system 300 presents an image of one or more field devices 250 and auto-detector 240 on system controller interface 223 or I/O master interface 225 as displayed on user interface 305 , and provides a hardcopy of one or more field devices 250 digital configuration data via a printer.
Workstation computer 310 is coupled to a network 330 . The network 330 is also coupled to a data depository 307 . Network 330 is also coupled to a slave processor 340 . Slave processor 340 is coupled to a memory 315 . Memory 315 is a memory for storing data and instructions for controlling the operation of slave processor 340 . An implementation of memory 315 could include a random access memory (RAM), a hard drive and a read only memory (ROM). One of the components of memory 315 is a program 320 . Slave processor 340 is also coupled to one or more field devices 350 .
Program 320 can includes instructions for controlling slave processor 340 , system controller 205 , I/O master 220 , or current control to drive either the safe current or HART current to one or more field devices 350 by employing auto-detector 240 . As a result of execution of program 320 , slave processor 310 can reads the digital configuration data into memory 315 from one or more field devices 250 , and can use this configuration data to configure system controller 205 or I/O master 220 . Program 320 may be implemented as a single module or as a plurality of modules that operate in cooperation with one another.
While program 320 is indicated as already loaded into memory 315 , it may be configured on a storage media 325 for subsequent loading into memory 315 by way of network 330 . Storage media 325 can be any conventional storage media such as a magnetic tape, an optical storage media, a compact disk, or a floppy disk. Alternatively, storage media 325 can be a random access memory, or other type of electronic storage, located on a remote storage system.
Slave processor 340 , through an I/O master 345 , then configures one or more field devices 350 with the configuration data. Slave processor 340 then controls and monitors one or more field devices 350 . I/O master 345 can correlate to I/O master 220 .
In FIG. 7 , in a current generation system 400 , a slave processor 410 is coupled to a current generator 420 . Both slave processor 410 and current generator 420 are coupled to a switch 430 . Switch 430 has a plurality of connections to field device 440 . Field device 440 has a feedback loop 450 coupled back to slave processor 410 .
Generally, slave processor 410 instructs current generator 420 whether to generate a current in a safe mode, perhaps 3.2 mA, or the standard 4.0 to 20.0 mA. 4-20 mA is standard instrumentation signal range. Slave processor 410 instructs switch 430 to which field devices or field devices of field device 440 should have the current applied. Slave processor 410 then reads the configuration data embedded within field device 440 over feedback loop 450 . Slave processor 410 can sense this configuration data, or alternatively, another device can extract the configuration data and then convey the configuration data to slave processor 410 . In one embodiment, this configuration data is then conveyed to system controller 205 and I/O master 220 (not shown in this FIGURE). Then, slave processor 410 , through switch 430 , uses configuration parameter read from field device 440 to configure field device 440 , using the a lower, safe current of less than 4.0 mA. Then, current generator 440 increases the current to the 4.0 to 20.0 mA range to operate field device 440 .
It should be understood that various alternatives, combinations and modifications of the teachings described herein could be devised by those skilled in the art. The present invention is intended to embrace all such alternatives, modifications and variances that fall within the scope of the present invention.
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A current generator that provides a first current level to read a configuration parameter of a field device. The current generator also provides a second current level. The first current level is lower in amperage than the second current level. The first current level does not operate the field device. The second current level operates the field device. A current sensor is connected in circuit with the field device. The current sensor reads the configuration parameter associated with the first current level. A method is provided that creates a current that reads a configuration parameter. The current has less than a minimum amplitude to operate necessary to operate a field device. The configuration parameter is read from the field device through employment of the current. The field device is configured through employment of the configuration parameter.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application claims priority to Indian patent application serial number 1031/CHE/2011 filed on Mar. 30, 2011, the entire contents of which are incorporated by reference.
TECHNICAL FIELD
[0002] Embodiments of the present disclosure relate to field of telecommunications. More particularly, embodiments relate to clock synchronization and fault protection for a telecommunications device. In particularly, embodiments relate to method and apparatus for zero traffic hit synchronization switchover in redundant systems.
BACKGROUND
[0003] Many telecommunications switching systems might include plurality of I/O Cards (called line cards) for processing different data from network interfaces like E1, DS1, STM-n, OC-n etc and send this processed data to traffic switch (Called Switch card) to switch data from one network interface to other. In such telecommunication systems the data from Line cards to switch card passes over a backplane which connects various cards in a system. Such telecommunication system is called network element. In a network there is plurality of such network elements. In networks like SONET/SDH, all these network elements need to work in locked mode traceable to PRC (Primary reference clock). For more information on network synchronization in SDH refer ITU-T standard G.813 and G.825. The synchronization from one network element to other is passed over various interfaces like E1, DS1, STM-n, OC-n etc. Each network element extract synchronization clock from one of these predefined interfaces and synchronize the network element (system synchronizer) so that all the outgoing interface from the said network element are in sync.
[0004] Further, to avoid single point of failure, it is well know method in telecommunication systems to replicate critical sub systems like power supply, switch card, network element controller (Called chassis controller), system synchronizer etc. Such sub systems are called redundant sub systems, one acting as master and one or more acting as slave sub systems.
[0005] In such redundant “system synchronizer” sub systems, the line cards, switch cards needs to switch from master synchronizer to slave synchronizer when master sub system fails or user initiates a switch over. In systems where the traffic switch and system synchronizer sub systems are on separate cards, the switch and Line cards need to switch form master synchronizer to slave synchronizer at the same time to avoid ppm (parts per million) difference in the system clock used by traffic switch and Line cards. This is not easily implementable.
[0006] Further it is very common to integrate traffic switch and system synchronizer in a single card to achieve more number of network interfaces in a given network element and to reduce cost. Also it is very common to use slave traffic switch using the timing from the slave system synchronizer and master traffic switch using timing from master system synchronizer. In such systems the above said problem (ppm difference in the system clock used by line cards and traffic switch during system synchronizer switch over) is more severe which lead to temporary or permanent logic errors which in turn lead to traffic hit. To recover from permanent traffic errors, system needs to be restarted. For bigger systems this may lead to traffic down for few seconds. Thus, prior techniques often do not allow the system to continue operating, uninterrupted and maintaining substantial data integrity.
[0007] In light of the foregoing discussion, there is a need for a method and device to solve the above mentioned problems.
SUMMARY OF THE DISCLOSURE
[0008] The shortcomings of the prior art are overcome and additional advantages are provided through the provision of a method and a system as described in the description.
[0009] The present disclosure solves the limitations of existing arts by providing a methodology for switchover in redundant system.
[0010] In one embodiment, the switch over methodology as disclosed in the disclosure prevents abrupt parts per million (ppm) between the traffic switch and the line blades for achieving the “Zero” traffic hit during switchover.
[0011] Additional features and advantages are realized through various techniques provided in the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered as part of the claimed disclosure.
[0012] In one embodiment, the present disclosure provides a method for switchover in redundant system. In the beginning, input reference of the receiver is switched from one or more master ( 1 ) to at least one slave ( 2 ). Said slave ( 2 ) becomes new master ( 2 ) and said one or more master ( 1 ) becomes new slave ( 1 ) after switching. Now, the new master ( 2 ) is locked to the new slave ( 1 ) for predetermined time period. Once the lock is confirmed, the new master ( 2 ) is disconnected from the new slave ( 1 ). Upon disconnection of the new slave ( 1 ), said new master ( 2 ) selects its own network reference clock. At this stage, the new slave ( 1 ) is locked to the new master ( 2 ) to synchronize the switchover in redundant systems.
[0013] In one embodiment, the predetermined time period is system dependent.
[0014] In one embodiment, the receiver includes but is not limiting to line card, and switching card.
[0015] The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
[0016] The novel features and characteristic of the disclosure are set forth in the appended claims. The embodiments of the disclosure itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings. One or more embodiments are now described, by way of example only, with reference to the accompanying drawings wherein like reference numerals represent like elements and in which:
[0017] FIG. 1 is a flow chart illustrating a switchover methodology adopted in a redundant system, in accordance with one embodiment of the present disclosure.
[0018] FIG. 2 is a block diagram showing switchover from master blade to slave blade, in accordance with one embodiment of the present disclosure.
[0019] FIG. 3 is a simplified block diagram of network element as shown in FIG. 2 , in accordance with one embodiment of the present disclosure.
[0020] The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.
DETAILED DESCRIPTION
[0021] The foregoing has broadly outlined the features and technical advantages of the present disclosure in order that the detailed description of the disclosure that follows may be better understood. Additional features and advantages of the disclosure will be described hereinafter which form the subject of the claims of the disclosure. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present disclosure. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the disclosure as set forth in the appended claims. The novel features which are believed to be characteristic of the disclosure, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present disclosure.
[0022] Embodiments of the present disclosure relate to a method for Zero traffic hit synchronization switch over when the master card ( 1 ) is jacked out of the system or user initiates switch over. Early indication of jackout of the master card ( 1 ) can be derived using industry standard mechanical ejector indication. Further, throughout the description herein below master, master card and master controller are interchangeably used. In this similar way slave, save card and slave controller are used.
[0023] Referring now to FIG. 1 , which illustrates step by step process adopted in the present disclosure for zero traffic hit synchronization switch over. The redundant network system includes two system synchronizer blades, say A and B. Number of these blades may vary from system to system. System synchronizer blade A is flagged as master blade and system synchronizer blade B is termed as slave blade. In the beginning A is nominated and is locked to network reference clock. Now, slave blade B locks to A. Thus, the slave blade B refers to the network reference clock. After this all line blades locks to A.
[0024] While switch over of system synchronization is initiated through GUI or start of master blade Jackout, all line blades switch to reference clock from A to B. However, A still locks to network reference clock and B still locks to A for predetermined time period. The time period can be in the range of 30 ms to 50 ms. However the range can be varied from system to system or network to network. Both A and B will keep track of time elapsed after locking. Once, the predetermined time period is over, for example 50 ms, all line blades locked to B. Now, B goes to hold over state. At this stage full system is synchronized to B except A.
[0025] When GUI switch over happens, B nominates the network reference clock and locks to network reference clock. Thereafter, blade A locks to blade B. Further, full system synchronizes to B. Thus, B becomes a master blade and A is slave blade. However, if master blade jackout happens, blade A waits for jack out completion and B nominates the network reference clock and locks to network reference clock. Further, full system synchronizes to B. Thus, B becomes a master blade.
[0026] The above sequence of steps would ensure smooth synchronization switch over without any parts per million (ppm) accumulations and thus achieve “Zero” traffic hit.
[0027] Referring now to FIG. 2 which illustrates block diagram of network element. The network element includes plurality of network components. The network components includes but are not limited to network interface card ( 3 ), traffic switch cards, one or more master controller ( 1 ), plurality of slave controller ( 2 ). In one embodiment, the network interface card ( 3 ) comprises frames processing logic, control logic, PLL logic, selection logic, etc. The detailed explanation of various elements as depicted in FIG. 2 is explained herein below. The simplified block diagram of network element as shown in FIG. 2 is illustrated in FIG. 3 .
[0028] Network interface card ( 3 ) terminates various network interfaces like E1, E3, DS1, DS3, STM-n, OC-n etc. Said network interface card (3) process the ingress traffic and send the processed traffic to the switch card for switching to other network interfaces. Further, the network interface card ( 3 ) recovers the clock which is received over the various network interfaces and sends these recovered clocks to one or more synchronization controller. The network interface card ( 3 ) changes the network traffic to new network element clock (system clock) domain before sending to the switch. For example, all the elements of SONET/SDH network element work with clock which is frequency locked to one central source for example, master controller PLL.
[0029] Any momentary parts per million (ppm) differences between traffic switch and network interface cards ( 3 ) lead to FIFO over flow at the interface between network interface card and traffic switch card. This difference may lead to traffic hit. Also, may lead to un-lock of the PLL's in the networks interface cards ( 3 ), which lead to the frame losses at the interfaces. The frame losses should not be allowed in the networks like SONET/SDH under equipment protection switch. In order to overcome such problems, the present disclosure provides solution of synchronization switch over technique.
[0030] In network elements, typically the traffic switch, Synchronization units are protected by providing the redundant traffic switch and synchronization units. In redundant systems, the network interface card ( 3 ), a traffic switch card receives the system clocks from all the redundant elements and selects one of them. The selected element is a master. The selection is done based on the commands from the controller over control communication channels. The selected master includes processor and memory for necessary processing as shown in FIG. 3 . In one embodiment, in redundant systems need may arise to switch the timing from master controller ( 1 ) to one of the slave controller ( 2 ) under faults or user initiated commands. If timing switching from master to slave happens in random sequence, there can be momentary ppm difference between the network interface card ( 3 ) and traffic switch which may lead to frame loss, PLL un-lock etc. This is not a required behavior in some of the telecom networks.
[0031] Another important element of the network element is controller card. Traffic switch element can be integrated with synchronization controller, wherein the synchronization controller consists of PLL and associated control functions or can be an independent element in the network element. For redundant systems these elements such as Synchronization controller and traffic switch are duplicated in which one of them acting as a master controller ( 1 )/traffic-switch and another as a slave controller ( 2 )/traffic-switch. The master controller ( 1 ) receives the network clock from all the network interface cards ( 3 ) and selects the high priority clock among these available clocks. The selected reference clock is given to master PLL. The master PLL distribute the clock to various elements in the network element like traffic switch, network interface cards ( 3 ). In one embodiment, the master controller ( 1 ) synchronizes with network clocks provided by the interface card ( 3 ) based on criteria selected from a group comprising the user-defined priority, and statistics. The Slave controllers ( 2 ) lock to reference clock from the master PLL. The slave controllers PLL output clocks are phase aligned to that of master controller PLL. The slaves distribute its output clocks to all other element in the network element similar to master. Now the slaves are ready for switch over. Further the master PLL loop bandwidth is as per network requirement and the slave PLL is configured in wide loop bandwidth filter to ensure lesser lock time in the slave PLL. There will be one control communication channel between Master ( 1 ) and slave controllers ( 2 ) to pass various messages including switch over message.
[0032] The present disclosure is not to be limited in terms of the particular embodiments described in this application, which are intended as illustrations of various aspects. Many modifications and variations can be made without departing from its spirit and scope, as will be apparent to those skilled in the art. Functionally equivalent methods and devices within the scope of the disclosure, in addition to those enumerated herein, will be apparent to those skilled in the art from the foregoing descriptions. Such modifications and variations are intended to fall within the scope of the appended claims. The present disclosure is to be limited only by the terms of the appended claims, along with the full scope of equivalents to which such claims are entitled. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting.
[0033] With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.
[0034] In addition, where features or aspects of the disclosure are described in terms of Markush groups, those skilled in the art will recognize that the disclosure is also thereby described in terms of any individual member or subgroup of members of the Markush group.
[0035] While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.
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Embodiments of the present disclosure relate to a Zero traffic hit synchronization switch over technique in a telecommunication network. The switch over is carried out by switching input reference of the receiver from one or more master ( 1 ) to at least one slave ( 2 ), wherein said slave ( 2 ) becomes new master ( 2 ) and said one or more master ( 1 ) becomes new slave ( 1 ) after switching. Now, the new master ( 2 ) locks to the new slave ( 1 ) for predetermined time period. Once the predetermined is elapsed, the new master ( 2 ) is disconnected from the new slave ( 1 ), wherein said new master ( 2 ) selects its own network reference clock upon disconnection of the new slave ( 1 ). The new slave ( 1 ) is locked to the new master ( 2 ) to synchronize the switchover in redundant systems.
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PRIORITY
[0001] This application claims the benefit under 35 U.S.C. §119(a) of a Korean patent application filed on Jul. 13, 2009 in the Korean Intellectual Property Office and assigned Serial No. 10-2009-0063752, the entire disclosure of which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to test handlers. More particularly, the present invention relates to a technology that can be applied to carrier boards for loading semiconductor devices having a ball type of electrical contact lead (BGA, FBGA, etc.), in a pick-and-place apparatus for electronic device inspection equipment.
[0004] 2. Description of the Related Art
[0005] Electronic devices such as, semiconductor devices are tested via a tester, when a test handler makes them electrically contact the tester.
[0006] Test handlers are closely related to technology involving electrical contact precision between electronic devices and the tester, temperature controllability, and an electronic device moving method. Of them, electrical contact precision is the most important factor. The present invention is related to how to guarantee electrical contact precision.
[0007] Semiconductor devices are electronic devices and their electrical contact leads are divided into a type of wire, for example, TSOP, SOP, TQFP, QFP, etc., and a type of ball, for example, BGA, FBGA, etc. It is very important that the electrical contact leads of the semiconductor device precisely contact the tester, irrespective of their type.
[0008] In particular, a semiconductor device having a ball type electrical contact lead exquisitely aligns a plurality of electrical contact leads on its underside, so the electrical contact leads may not electrically contact the tester if the semiconductor device is even slightly misaligned.
[0009] In general, test handlers transfer semiconductor devices via a carrier board (also called a test tray, a test board, or the like) and also allow the semiconductor devices loaded on the carrier board to electrically contact the tester.
[0010] A carrier board includes a plurality of inserts (also called a carrier, a carrier module, etc.) aligned in a matrix form. An insert loads one or more semiconductor devices thereon. A technology related to a carrier board and an insert was disclosed in Korean Patent Publication No. 10-2005-0009066 entitled “carrier module for semiconductor device test handlers,” which is hereinafter referred to as a “well-known technology.” This publication discloses the insert in which a BGA chip can be properly placed.
[0011] FIG. 1 is a view illustrating a conventional insert that loads semiconductor devices with BGA type electrical contact leads.
[0012] Referring to FIG. 1 , the conventional insert forms a placement compartment 111 that corresponds in size to a semiconductor device in a loaded part 110 on which a semiconductor device is loaded. The bottom side of the placement compartment 111 is perforated so that the ball type of electrical contact leads of the placed semiconductor device can be electrically contacted with the tester.
[0013] In addition, the placement compartment 111 also forms grooves, corresponding to the shape and spacing of the balls of the semiconductor device, on the inner wall of the perforated bottom side thereof.
[0014] When a semiconductor device is appropriately placed in the placement compartment, the balls of the semiconductor device are inserted into the grooves of the placement compartment, so that the semiconductor device can be stably loaded on the loaded part 110 .
[0015] Meanwhile, since the semiconductor devices loaded in the carrier board are electrically contacted with a tester, the test handler is equipped with a pick-and-place apparatus that can load semiconductor devices from a customer tray onto a carrier board or unload semiconductor devices from a carrier board onto a customer tray.
[0016] The pick-and-place apparatus includes a plurality of picking apparatuses each of which can pick and place one semiconductor device.
[0017] In general, a picking apparatus includes a picker that sucks and picks a semiconductor device according to vacuum pressure or places it by releasing the vacuum pressure.
[0018] The following description describes the transfer and loading methods of semiconductor devices in a conventional picking apparatus.
[0019] The picking apparatus sucks and picks semiconductor devices from a loading element A (which may be a customer tray, a buffer, an aligner, a carrier board, etc.) and is then moved up over a loading element B (which may be a customer tray, a buffer, an aligner, a carrier board, etc.). When the pick-and-place apparatus moves, the picking apparatuses are also moved. The pick-and-place apparatus is lowered a certain distance above the loading element B and then places the semiconductor devices thereon, so that the semiconductor devices can be dropped and loaded on the loading element B.
[0020] However, semiconductor devices with a ball type of electrical contact leads have a relatively narrow spacing between their electrical contact leads, so they can be easily misaligned in the carrier board due to an impact when the semiconductor devices are dropped or an impact accompanying an operation where the apparatuses hold the semiconductor devices. In that case, the semiconductor devices cannot be electrically contacted with the tester, which causes test failure.
SUMMARY OF THE INVENTION
[0021] An aspect of the present invention is to address at least the above-mentioned problems and/or disadvantages and to provide at least the advantages described below. Accordingly, an aspect of the present invention is to provide a pick-and-place apparatus that can load semiconductor devices on a loading element, without causing an impact when the semiconductor devices are placed, and irrespective of an impact accompanying the operation of a holding apparatus.
[0022] In accordance with an aspect of the present invention, an apparatus for electronic device inspection equipment is provided. The apparatus includes a plurality of picking apparatuses that pick up electronic devices loaded on one loading element (A), move the electronic devices, and unloads the electronic devices onto another loading element (B), and a module-forming block that joins the plurality of picking apparatuses in one module. At least one picking apparatus includes: a body fixed to the module-forming block, a picker having a picking unit, coupled to the body, for picking up an electronic device or releasing the picked electronic device, and a guiding unit for interacting with another loading element (B) and for guiding the picker to load the electronic devices at a correct position on another loading element (B).
[0023] Preferably, the guiding unit comprises a guiding member having position setting pins, joined to the body, for setting positions between the picker and another loading element (B) by being inserted into position setting holes formed in another loading element (B).
[0024] Preferably, the guiding member is joined to the body so that it can be relatively moved within a preset range of movement distance with respect to the body in the direction of another loading element (B) or opposite thereto. The guiding unit further includes an elastic member (C) exerting an elastic force on the guiding member toward another loading element (B).
[0025] Preferably, at least one picking apparatus further includes another elastic member (D) for maintaining an elastic force with respect to the module-forming block, another elastic member being joined so that it can be relatively moved within a preset range of movement distance with respect to the module-forming block in the direction toward another loading element (B) or opposite thereto. Another elastic member (D) has a greater elastic coefficient than the one elastic member (C) does.
[0026] Preferably, at least one picking apparatus further includes another elastic member (D) for maintaining an elastic force with respect to the module-forming block. Another elastic member is joined so that it can be relatively moved within a preset range of movement distance with respect to the module-forming block in the direction toward another loading element (B) or in the opposite direction thereto.
[0027] Preferably, the pick-and-place apparatus may further include coupling pins with a head and a coupling part for coupling at least one picking apparatus to the module-forming block, in which the coupling part forms a thread on at least one end portion thereof. The module-forming block forms coupling through-holes for coupling at least one picking apparatus therewith, and the body forms a threaded hole into which the coupling part of the coupling pin passing through the coupling through-hole is screwed.
[0028] Preferably, the coupling part has an external diameter smaller than its internal diameter of coupling through-hole.
[0029] Preferably, the picking apparatus is coupled to the module-forming block in a certain range of angle with respect to a straight line passing through the module-forming block, the picking apparatus, and another loading element (B).
[0030] In accordance with another aspect of the present invention, an apparatus of a pick-and-place apparatus for electronic device inspection equipment is provided. The apparatus includes: a body fixed to a module-forming block of the pick-and-place apparatus, a picker having a picking unit, coupled to the body, for picking up an electronic device or releasing the picked electronic device, and a guiding unit for interacting with a loading element and for guiding the picker to load the electronic devices at a correct position on the loading element.
[0031] Preferably, the guiding unit comprises a guiding member having position setting pins, joined to the body, for setting positions between the picker and the loading element by being inserted into position setting holes formed in the loading element.
[0032] Preferably, the guiding members include a plurality of position setting pins.
[0033] Preferably, the position setting pin is formed in such a way that its one end protrudes more toward the loading element than one end of the picking unit of the picker, so that the position pin can first set a position between the picker and the loading element before the semiconductor device, picked up by the picking unit, is placed in a carrier board.
[0034] Preferably, the guiding member is joined to the body so that it can be relatively moved within a preset range of movement distance with respect to the body in the direction of the loading element or opposite thereto. The guiding unit further includes an elastic member exerting an elastic force on the guiding member toward the loading element.
[0035] In accordance with still another aspect of the present invention, an aligner for inspection equipment of electronic devices is provided. The aligner is formed with a plurality of aligning grooves in which semiconductor devices are aligned and placed and pin receiving walls that are protrudent at both sides of the aligning groove. The pin receiving walls form pin receiving holes into which position setting pins of a pick-and-place apparatus are inserted.
[0036] In accordance with yet another aspect of the present invention, a method for loading electronic devices onto a loading element in electronic device inspection equipment is provided. The method includes: releasing a holding state of a holding apparatus installed to a loading element on which electronic devices are loaded, moving the pick-and-place apparatus toward the loading element and setting a position between the loading element and a picker that picks up an electronic device, placing the electronic device, picked up by the picker, in the loading element and holding the placed electronic device, releasing the picking state of the picker, and moving the pick-and-place apparatus in the direction opposite to the loading element.
[0037] Preferably, placing the electronic device and holding the placed electronic device includes: placing the electronic device, picked up by the picker, in the loading element, moving additionally the picker by a distance corresponding to a distance by which the loading element is retroceded in the same direction as the pick-and-place apparatus moves, so that the electronic device can remain in the loading element, and holding the electronic device.
[0038] Preferably, the method may further include loading different electronic devices on the loading element, only if the different electronic devices have the same type and position of electrical contact lead as the electronic devices.
[0039] Other aspects, advantages, and salient features of the invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses exemplary embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0040] The above and other aspects, features, and advantages of certain exemplary embodiments of the present invention will be more apparent from the following description taken in conjunction with the accompanying drawings, in which:
[0041] FIG. 1 is a view illustrating a conventional insert that loads semiconductor devices with BGA type electrical contact leads;
[0042] FIG. 2 is a perspective view illustrating a pick-and-place apparatus according to an embodiment of the present invention;
[0043] FIG. 3 is a perspective view illustrating a picking apparatus applied to the pick-and-place apparatus of FIG. 2 according to an exemplary embodiment of the present invention;
[0044] FIG. 4 is a front view of the picking apparatus of FIG. 3 according to an exemplary embodiment of the present invention;
[0045] FIGS. 5A to 5D are views illustrating an insert corresponding to the picking apparatus of FIG. 3 according to an exemplary embodiment of the present invention;
[0046] FIG. 6 and FIG. 7 are views that describe a coupling state of the pick-and-place apparatus of FIG. 2 according to an exemplary embodiment of the present invention;
[0047] FIG. 8 to FIG. 18 are views that describe the operation of the pick-and-place apparatus according to an exemplary embodiment of the present invention;
[0048] FIG. 19 is a view illustrating an aligner adapted to the pick-and-place apparatus according to an exemplary embodiment of the present invention; and
[0049] FIG. 20 and FIG. 21 are cross-sectional views that describe a method where the pick-and-place apparatus picks up semiconductor devices from the aligner, according to an exemplary embodiment of the present invention.
[0050] Throughout the drawings, it should be noted that like reference numbers are used to depict the same or similar elements, features, and structures.
BRIEF DESCRIPTION OF SYMBOLS IN THE DRAWINGS
[0051] 200 : pick-and-place apparatus
[0052] 210 : picking apparatus
[0053] 211 : body
[0054] 211 a: threaded hole
[0055] 212 : picker
[0056] 212 a: holding unit
[0057] 213 : guiding unit
[0058] 213 a: guiding member
[0059] 213 a - 1 , 213 a - 2 : position setting pin
[0060] 213 b - 1 , 213 b - 2 : spring
[0061] 214 a, 214 b: elastic member
[0062] 220 : module-forming block
[0063] 221 : coupling through-hole
[0064] 230 : coupling pin
[0065] 231 : head
[0066] 232 : coupling part
[0067] 232 a: thread
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0068] The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of exemplary embodiments of the invention as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the invention. In addition, descriptions of well-known functions and constructions are omitted for clarity and conciseness.
[0069] The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the invention. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present invention are provided for illustration purpose only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.
[0070] It is to be understood that the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a component surface” includes reference to one or more of such surfaces.
[0071] FIG. 2 is a perspective view illustrating a pick-and-place apparatus 200 according to an exemplary embodiment of the present invention.
[0072] Referring to FIG. 2 , the pick-and-place apparatus 200 includes 16 picking apparatuses 210 , a module-forming block 220 , and coupling pins 230 .
[0073] As shown in FIG. 3 , each of the picking apparatuses 210 includes a body 211 , a picker 212 , a guiding unit 213 , and a pair of elastic members 214 a and 214 b.
[0074] The body 211 is shaped as the letter ‘L’ viewed from the side. The body 211 is joined to the module-forming block 220 using coupling pins 230 , so that the body 211 can move up and down, with being close to or far from the module-forming block 220 in a certain range of movement distance. The body 211 can be moved in one direction, i.e., toward a carrier board, and in the opposite direction thereto, i.e., toward the module-forming block 220 . The body 211 forms threaded holes 211 a for receiving the coupling pins 230 on its upper side. The body 211 includes a pair of guide bars 211 b - 1 and 211 b - 2 on the upper side, located at both opposite sides with respect to the threaded hole 211 a, so that the guide bars 211 b - 1 and 211 b - 2 can guide the vertical movement of the body or prevent unintentional rotation of the picking apparatus 210 . The body 211 is further cut off at its both sides, viewed from the front, and allows an LM guider 211 c to be located at the cut-off portions. The LM guider 211 c guides the vertical movement of a guiding member.
[0075] The picker 212 is joined with the body 211 . The picker 212 includes a picking unit 212 a for picking or releasing a semiconductor device at its lower end. The picking unit 212 a is made of a flexible material.
[0076] The guiding unit 213 is located at the cut-off portions of the body 211 . The guiding unit 213 is interacted with an insert of a carrier board and guides the picker 212 so that it can load a semiconductor device at a precise position in the carrier board.
[0077] The guiding unit 213 includes a guiding member 213 a and a pair of springs 213 b - 1 and 213 b - 2 .
[0078] The guiding unit 213 is shaped as the letter T viewed from the front. The guiding unit 213 is joined to the body 211 , so that the guiding unit 213 can be guided by the LM guider 211 c and thus be moved up and down with respect to the body 211 in a preset movement distance. The guiding unit 213 can be moved in one direction, i.e., toward a carrier board, and in an opposite direction thereto, i.e., toward the module-forming block 220 . The guiding unit 213 further forms a stopper STP, shaped as the letter ‘L’ viewed from below, at its lower portion. While the body 211 is being lowered in a state where the lower surface of the stopper STP contacts the upper surface of the insert, the stopper STP serves to prevent the body 211 from being lowered after it has been lowered a certain distance, which will be explained in detail later.
[0079] The L-shaped stopper STP forms position setting pins 213 a - 1 and 213 a - 2 at both opposite ends of the letter ‘L’ on its lower surface, where the positions of the position setting pins 213 a - 1 and 213 a - 2 correspond to those of position setting holes that are formed on the diagonal line in the insert, which will be described in detail later.
[0080] As shown in FIG. 5A (a perspective view illustrating an insert) and FIG. 5B (a top view illustrating the insert of FIG. 5A ), the diameters and the spacing distance between the position setting pins 213 a - 1 and 213 a - 2 correspond to those of the position setting holes 511 a and 511 b of the insert 510 , respectively. The position setting pins 213 a - 1 and 213 a - 2 are shaped as a circular cone at their end portion so the peak of the cone can allow the position setting pins 213 a - 1 and 213 a - 2 to be easily inserted into the position setting holes 511 a and 511 b although the centers between the position setting pins 213 a - 1 and 213 a - 2 and the position setting holes 511 a and 511 b are not completely aligned with each other. In addition, as shown in FIG. 4 , the lower ends of the position setting pins 213 a - 1 and 213 a - 2 are protruded toward the carrier board by a length that is a longer than the lower end of the holding unit 212 a of the picker 212 . This is because the picker 212 and the carrier board, i.e., the picker 212 and the insert 510 , can set their position first before the semiconductor device picked by the holding unit 212 a is placed in the carrier board.
[0081] Referring to FIGS. 5A and 5B , the bottom side of the placement compartment 512 of the insert 510 is perforated. The inner wall around the perforated bottom side forms grooves 512 a that are arranged, matching the shape and spacing of the balls of the semiconductor device. The area of the bottom side of the placement compartment 512 is much greater than the total area occupied by the balls of a semiconductor device, so that the insert can receive various sizes of semiconductor devices only if the position of their balls is standardized. For example, as shown in FIGS. 5C and 5D , although semiconductor devices D 1 and D 2 have different areas S 1 ×L 1 and S 1 ×L 1 , respectively, they can be placed in the same insert 510 only if the position and shape of the ball 1 b, serving as an electrical contact lead, are standardized.
[0082] In an embodiment of the present invention as shown in FIGS. 5C and 5D , although the balls of a semiconductor device are inserted into all the grooves 512 a formed in the bottom side of the placement compartment 512 , it should be understood that the present invention is not limited to the embodiment. For example, if different semiconductor devices have the same sized balls spaced apart with the same spacing, they can be placed in the placement compartment 512 as the balls of each of the semiconductor devices are inserted into the grooves 512 a formed in at least only one side of the bottom side of the placement compartment 512 . Therefore, this structure enlarges the universality of the insert 510 .
[0083] As shown in FIGS. 5A and 5B , holding apparatuses 513 a and 513 b hold a semiconductor device placed in the placement compartment 512 .
[0084] Referring back to FIG. 3 , the pair of springs 213 b - 1 and 213 b - 2 are placed between the guiding member 213 a and the lower surface of the upper portion of the body 211 . The pair of springs 213 b - 1 and 213 b - 2 exert an elastic force to the guiding member 213 a in the lower direction (i.e., in the direction toward the carrier board).
[0085] The pair of elastic members 214 a and 214 b are configured to contain guide bars 211 b - 1 and 211 b - 2 inserted thereinto, respectively. The pair of elastic members 214 a and 214 b exert an elastic force in lower direction (i.e., in the direction toward the carrier board) by an elastic repulsive force between the module-forming block 220 and the picking apparatus 210 . In an embodiment of the present invention, the pair of elastic members 214 a and 214 b are implemented with a coil spring. The pair of elastic members 214 a and 214 b have a much greater elastic coefficient than that of the pair of springs 213 b - 1 and 213 b - 2 .
[0086] The following description explains the function of the stopper STP with reference to FIG. 6 .
[0087] As shown in FIG. 6 , if the lower surface of the stopper STP contacts the upper surface of the insert 510 , the position setting pins 213 a - 1 and 213 a - 2 cannot further enter the position setting holes 511 a and 511 b. As such, at the time that the lower surface of the stopper STP contacts the upper surface of the insert 510 , it is preferable that the interval a 1 between the upper surface of the stopper STP and the lower surface of the body 211 is equal to or a little greater than the interval a 2 between the placement surface of the insert 510 and the lower surface of the semiconductor device picked by the picker 212 .
[0088] Referring to FIG. 7 , after the lower surface of the stopper STP contacts the upper surface of the insert 510 , the guiding member 213 a cannot be further lowered by the stopper STP although the pick-and-place apparatus 200 continues to be lowered. Therefore, only the body 211 is lowered, by compressing the pair of springs 213 b - 1 and 213 b - 2 .
[0089] If the lower surface of the body 211 being lowered contacts the upper surface of the stopper STP as shown in FIG. 7 , the lowering operation of the body 211 is stopped. In this state, the continued lowering operation of the pick-and-place apparatus 200 causes the compression of the pair of elastic members 214 a and 214 b.
[0090] The module-forming block 220 serves to join 16 picking apparatuses 210 in one module. To this end, as shown in FIG. 8 , the module-forming block 220 forms 16 coupling through-holes 221 in a vertical direction.
[0091] The module-forming block 220 also forms guiding holes 222 a and 222 b, through which the guide bars 211 b - 1 and 211 b - 2 pass, at both sides of each coupling through-hole 221 .
[0092] Referring to FIG. 8 , the coupling pins 230 is formed with a head 221 and a coupling part 232 . The coupling part 232 forms a thread on its lower portion. The coupling pins 230 pass through the coupling through-hole 221 and its lower portion is screwed into the threaded hole 211 a of the body 211 , thereby joining the picking apparatus 210 with the module-forming block 220 . It is preferable that the external diameter b of the coupling part 232 is smaller than the internal diameter c of the coupling through-hole 221 , i.e., b<c. This allows the picking apparatus 210 to be coupled to the module-forming block 220 with a flexible movement margin that is within range of angle θ with respect to the perpendicular line L passing the center of the module-forming block 220 toward the carrier board. Therefore, although the position setting pins 213 a - 1 and 213 a - 2 are not completely consistent with the center of the position setting holes 511 and 512 , respectively, they can be smoothly inserted into the position setting holes 511 and 512 .
[0093] If the internal diameter c of the coupling through-holes 221 is much smaller than the external diameter b of the coupling part 232 , the clearance of the picking apparatus 210 is increased. It is preferable that the difference between the internal diameter c of the coupling through-hole 221 and the external diameter b of the coupling part 232 is 0.1˜0.05 mm, experimentally. It should be understood that the difference between the internal diameter c of the coupling through-hole 221 and the external diameter b of the coupling part 232 may differ according to the vertical length of the pick-and-place apparatus or the length of the coupling pin.
[0094] The following description explains the operation of the pick-and-place apparatus 200 , based on one picking apparatus 210 , with reference to FIGS. 10 to 18 .
1. Pick and Move Semiconductor Devices (Refer to FIG. 10)
[0095] The pick-and-place apparatus 200 sucks and picks up semiconductor devices D from a loading element 700 , such as a customer tray, aligner, or the like, and moves them (in the direction of the arrow) above a carrier board 500 located a reference height H. The aligner, an example of the loading element 700 , will be explained in detail later.
2. Release the Holding State of the Carrier Board (Refer to FIG. 11)
[0096] An opener 900 , located at the lower side of the carrier board 500 , rises (in the direction of arrow {circle around (a)}) and operates the holding units 513 a and 513 b of the inserts 510 of the carrier board 500 , thereby releasing the holding state of the holding unit 513 a and 513 b. When the opener 900 rises, the insert 510 , installed to the carrier board 500 , is lifted by h (refer to arrow {circle around (b)}).
[0097] As exaggeratedly shown in FIG. 12 , the carrier board 500 is equipped with a guide rail 800 on its lower surface. The lower surface is located at the reference height H with a vertical movement tolerance h 1 by the guide rail 800 . The guide rail 800 serves to prevent the separation of the carrier board 500 in the upper direction or lower direction. In addition, the insert 510 is also installed to the carrier board 500 , so as to have a vertical movement tolerance h 2 (h 2 =h−h 1 ). In that case, the insert 510 can be ascended by the movement tolerance itself. Therefore, when the opener 900 rises, the insert 510 is ascended by h (h=h 2 +h 1 )
[0098] Since technology related to openers is already well-known via various documents, for example, Korean Patent Registration No 10-0687676, etc., a detailed description is not included in this application.
3. Set Position Between Picker and Carrier Board (Refer to FIG. 13)
[0099] The pick-and-place apparatus 200 is lowered toward the carrier board 500 (refer to the arrow direction shown in FIG. 13 ) so that the position setting pins 213 a - 1 and 213 a - 2 are inserted into the position setting holes 511 a and 511 b. During this process, the positions between the insert 510 and the picker 212 that picks up a semiconductor device D are precisely set, so as to match the center between the picker 212 and the placement compartment 512 of the insert 510 (Since the picker picks up the center of the semiconductor device, the center of the semiconductor device can be coincident with that of the placement compartment).
4. Place and Hold Semiconductor Devices
[0100] 4-1. Place Semiconductor Devices (Refer to FIG. 14 )
[0101] In a state where the positions between the picker 212 and the carrier board 500 , i.e., the picker 212 and the insert 510 , are precisely set as shown in FIG. 13 , the pick-and-place apparatus 200 continues being lowered (refer to the arrow shown in FIG. 14 ), so that the semiconductor device D can be precisely placed at the correct position in the placement compartment 512 . Since the lower surface of the stopper STP contacts the upper surface of the insert 510 before the semiconductor device D is placed in the placement compartment 512 , the lowering operation of the pick-and-place apparatus 200 lowers only the picker 212 that is integrally coupled with the body 211 . On the other hand, the guiding member 213 a, which is relatively ascended with respect to the picker 212 but which is stopped actually, compresses a pair of springs 213 b - 1 and 213 b - 2 until the lower surface of the body 211 contacts the upper surface of the stopper STP.
[0102] 4-2. Compress a Pair of Elastic Members (Refer to FIG. 15 )
[0103] In a state where the guiding member 213 a has relatively risen within a preset range of movement distance with respect to the picker 212 and thus the pair of springs 213 b - 1 and 213 b - 2 are compressed as shown in FIG. 14 , if the pick-and-place apparatus 200 continues to be lowered as shown in FIG. 15 , the module-forming block 220 is lowered and a pair of elastic members 214 a and 214 b, located between the picking apparatus 210 and the module-forming block 220 , are also compressed, so that the picking apparatus 210 is relatively ascended (but stopped actually) with respect to the module-forming block 220 . Therefore, if the picking apparatus 210 has relatively risen within a preset range of movement distance with respect to the module-forming block 220 and thus the pair of elastic members 214 a and 214 b have been also compressed, the pick-and-place apparatus 200 stops its lowering operation.
[0104] The pick-and-place apparatus 200 does not perform an ascending/descending operation until the pick-and-place apparatus 200 loads the semiconductor device D in a state shown in FIG. 5 and then rises again. After that, the picker 212 is lowered according to an elastic force of the pair of elastic members 214 a and 214 b.
[0105] 4-3. Continue Placing the Semiconductor Devices (Refer to FIG. 16 )
[0106] When the semiconductor device D is loaded from a correct placement position and the pair of springs 213 b - 1 and 213 b - 2 and the pair of elastic members 214 a and 214 b are compressed by preset lengths, respectively, the opener 900 is lowered in the direction of arrow as shown in FIG. 16 in order to hold the semiconductor device D. In that case, the insert 510 that rose by a height h as the opener 900 was rising lowers by a height h (h=h 1 +h 2 , where h 1 is the lowered height of the carrier board 500 and h 2 is the lowered height of the insert 510 ). While the insert 510 is being lowered, the pair of elastic members 214 a and 214 b push the picking apparatus 210 in the lower direction, so that the picking apparatus 210 is lowered by a height h. Therefore, the semiconductor device D sucked and picked up by the picker 212 can continue pushing the placement side of the insert 510 .
[0107] Since the picker 212 still sucks and picks up the semiconductor device D while the opener 900 is being lowered, the semiconductor device D can stably retain its placement state at the placement position even though a vibration according to the lowering operation of the opener 900 occurs.
[0108] 4-4. Hold Semiconductor Devices (Refer to FIGS. 17A and 17B )
[0109] In a state where the carrier board 500 and the insert 510 have been lowered, if the opener 900 is further lowered in the direction of arrow, as shown in FIGS. 17A and 17B , the holding units 513 a and 513 b hold the semiconductor device D.
5. Release a Picking State of the Picker
[0110] When the holding units 513 a and 513 b have performed their holding operations, the vacuum pressure is released so that the picker 212 can release its sucking and picking state of the semiconductor device D.
6 . Lift of the Pick-and-Place Apparatus (Refer to FIG. 18)
[0111] When the picker 212 releases the picking state of the semiconductor device D, the pick-and-place apparatus 200 is moved up opposite the carrier board 500 , i.e., in the upper direction (refer to the direction of the arrow).
[0112] The following description explains the function of the aligner as a loading element of the pick-and-place apparatus 200 .
[0113] The aligner refers to a loading element that arranges semiconductor devices before the pick-and-place apparatus 200 loads them onto the carrier board 500 . The aligner must be configured to be applied to the pick-and-place apparatus 200 according to an embodiment of the present invention.
[0114] FIG. 19 is a view illustrating an aligner adapted to the pick-and-place apparatus 200 according to an exemplary embodiment of the present invention.
[0115] Referring to FIG. 19 , the aligner 700 A forms a plurality of aligning grooves 710 on which semiconductor devices are loaded and aligned. At both sides of each aligning groove 710 , pin receiving walls 720 are protrudently formed with a relatively high height. The pin receiving walls 720 form pin receiving holes 721 into which the position setting pins 213 a - 1 and 213 a - 2 of the pick-and-place apparatus 200 are inserted.
[0116] The following description explains a method where the pick-and-place apparatus 200 picks up semiconductor devices from the aligner 700 A, with reference to FIG. 20 .
[0117] Referring to FIG. 20 , when the pick-and-place apparatus 200 is lowered to pick up semiconductor devices loaded on the aligning grooves 710 of the aligner 700 A, the position setting pins 213 a - 1 and 213 a - 2 are inserted into the pin receiving holes 721 and the lower surface of the stopper STP contacts the upper surface of the pin receiving wall 720 . As shown in FIG. 21 , according as the pick-and-place apparatus 200 continues lowering, the lowering operation of the guiding member 213 a is stopped but only the picker 212 is still lowered, so that the picker 212 can pick up the semiconductor device D.
[0118] Although the embodiment of the present invention has been explained based on the pick-and-place apparatus 200 with 16 picking apparatuses 210 , it should be understood that the present invention is not limited to the embodiment. For example, it can be modified in such a way that the pick-and-place apparatus can be equipped with a plurality of modules aligned in parallel, each module having 16 picking apparatuses.
[0119] As described above, the pick-and-place apparatus according to the present invention can precisely load and place semiconductor devices at a placement position in a loading element (in particular, in a carrier board), thereby guaranteeing the stability of the electrical contact between the semiconductor devices and the tester.
[0120] While the invention has been shown and described with reference to certain exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims and their equivalents.
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A technology related to a pick-and-place apparatus for electronic device inspection equipment is provided. The pick-and-place apparatus includes the guiding unit that can interact with a loading element and can guide the picker to load the electronic devices at a correct position on the loading element. Therefore, the pick-and-place apparatus can allow the electronic devices, for example, semiconductor devices having a ball type of electrical contact lead (BGA, FBGA, etc.), to electrically contact the tester in a stable manner when the tester inspects the electronic devices.
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This application claims the benefit of Korean Patent Application No. 10-2006-0055889, filed on Jun. 21, 2006, which is hereby incorporated by reference as if fully set forth herein.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a still operation of a washing machine, and more particularly, to a washing machine which includes an operation condition of the washing machine in correspondence with each of a plurality of stillness modes and operates according to the operation condition corresponding to any one selected from the plurality of stillness modes.
2. Discussion of the Related Art
In general, when dirty clothes are put into washing water, the clothes are washed by a chemical action of a detergent. However, if only the detergent is used, a washing time is long and the clothes may be damaged. Accordingly, in a washing machine, a mechanical action such as proper friction or vibration is applied to the clothes immersed in the washing water, for the purpose of improving a washing speed.
A drier is a mechanical device for drying wet laundry by hot air.
A washing machine is a device for processing laundry, which includes a washer, a drier, and dehydrator.
Recently, a consumer's request for the improvement and diversification of the capability of the washing machine is gradually increasing. A consumer's request for a still operation of the washing machine is also gradually increasing.
Consumers want a quite life. In particular, since there are frequent occasions when a washing machine is driven at night, a still operation is required.
A consumer may want or may not want a still operation. If a consumer wants a short operation time of a washing machine due to lack of time, a still operation may not be required.
However, a conventional washing machine is designed such that there is no room for selecting a stillness degree of an operation. Although a consumer wants a higher stillness degree of an operation, the washing machine should operate in a stillness mode set previously.
A consumer does not need to necessarily select the stillness degree of the operation, but a washing machine requires a variety of stillness modes. The stillness mode may vary depending on a condition.
For example, a dehydration operation of a conventional washing machine will be described with reference to FIGS. 1 and 2 .
First, FIG. 1 is a flowchart illustrating a dehydration operation method of a conventional washing machine and FIG. 2 is a graph showing rotation speed (RPM) versus time in the dehydration operation method of the conventional washing machine.
In general, the dehydration function of the washing machine includes steps of disentangling laundry, evenly distributing the laundry, and detecting an unbalance amount (hereinafter, referred to as a UB amount). A drum stops or accelerates to perform a main dehydration mode according to the result of detecting the UB amount.
Now, a method of detecting the UB amount will be described with reference to FIGS. 1 and 2 .
First, when a mode is switched to a dehydration mode, the rotation speed of the drum (not shown) in which laundry is contained increases and this state is maintained (S 1 ).
Next, a degree to which the laundry is unevenly distributed in the drum, that is, the UB amount, is detected (S 2 ).
For example, the UB amount is detected using a variation in rotation speed of a motor. That is, while rotating the motor by a predetermined dehydration algorithm, a position detection hall sensor mounted in the motor detects the rotation speed of the motor in a predetermined time period to measure a variation in rotation speed of the motor, and the UB mount is detected using a difference between a maximum value and a minimum value of the measured values. Since the method of detecting the UB amount is widely known, the detailed description thereof will be omitted.
Next, it is determined whether the UB amount is greater than an allowable value of a system, that is, a reference UB amount (S 3 ).
If it is determined that the UB amount is greater than the reference UB amount, the dehydration operation is stopped in order to prevent the system from being damaged due to excessive rotation (S 4 ) In contrast, if it is determined that the UB amount is less than the reference UB amount, the rotation speed of the motor increases and the main dehydration operation is performed (S 5 ).
In the main dehydration operation, the drum rotates up to a maximum rotation speed.
Noise and vibration occur in the above-described dehydration operation of the washing machine.
In particular, noise or vibration varies depending on the condition of a floor on which the washing machine is installed. For example, in a case where the washing machine is installed on a wooden floor, the noise or vibration of the washing machine increases compared with a case where the washing machine is installed on a concrete floor.
Although the washing machine is installed on the same floor, a degree to which the noise or vibration is felt by a consumer varies depending on a use time period. The noise or vibration is felt to be larger during a quiet night than during the day.
Such a problem is not restricted to the dehydration operation and may be generated in a washing operation or a drying operation.
A principal factor for the noise or vibration may be related to the rotation speed of the drum. When the rotation speed of the drum increases in the washing operation, the drying operation or the dehydration operation, the noise or vibration increases.
That is, since the conventional washing machine is designed such that there is no room for selecting a stillness degree of an operation, a user feels inconvenience.
SUMMARY OF THE INVENTION
Accordingly, the present invention is directed to a washing machine with a stillness mode and method of operating the same that substantially obviate one or more problems due to limitations and disadvantages of the related art.
An object of the present invention is to provide a washing machine which includes a plurality of stillness modes with relation to a still operation, and performs an operation by properly selecting any one of the plurality of stillness modes according to a use environment or the situation of a consumer.
Another object of the present invention is to provide a washing machine which is capable of performing a still operation desired by a consumer by changing an operation condition according to the condition of a floor on which the washing machine is installed.
Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, a washing machine includes a controller which, by the selection of any one of a plurality of stillness modes which are distinguished according to a stillness degree of an operation, controls the washing machine according to an operation condition corresponding to the selected stillness mode.
Even under the same operation condition, the stillness degree may vary depending on an environment in which the washing machine is installed. For example, in a case where the washing machine is installed on a wooden floor, the stillness degree is lower compared with the case where the washing machine is installed on a concrete floor.
At this time, when the operation condition is changed by selecting a proper stillness mode, a still operation can be realized even when the washing machine is installed on the wooden floor.
When a higher stillness mode is required, a proper stillness mode is selected in the same installation environment and the washing machine is controlled to be operated in the operation condition corresponding to the selected stillness mode.
Accordingly, the plurality of stillness modes are preferably distinguished according to the installation environment of the washing machine. The installation environment preferably includes the condition of a floor on which the washing machine is installed.
A user may select a stillness mode corresponding to the floor condition so as to operate the washing machine in an operation condition suitable for the floor condition, thereby ensuring stillness. For example, a first stillness mode is selected in the concrete floor and a second stillness mode is selected in the wooden floor. The first stillness mode may be set to a default mode.
Preferably, the washing machine may further include a stillness mode selector for allowing the user to select any one of the plurality of stillness modes. The selector may be configured in the form of a button. The user presses a button corresponding to a desired stillness mode to select the stillness mode.
At least one of the plurality of stillness modes may be set as a default mode. For example, when the number of stillness modes is two, one stillness mode is automatically selected between them and a general operation of the washing machine is performed in the stillness mode selected automatically. When the other stillness mode is selected, the washing machine operates in the selected mode. The selector may include a selection button.
Preferably, the plurality of stillness modes may be distinguished according to a vibration degree. It is preferable that the still operation is related to vibration as well as noise.
In particular, if a house type is an apartment, a house located just below a house where a washing machine operates feels inconvenience due to the delivery of vibration via a floor, rather than due to noise which occurs in the washing machine. Accordingly, it is preferable that the plurality of stillness modes are distinguished according to the vibration degree.
The vibration for distinguishing among the stillness modes is preferably the vibration of the external appearance of the washing machine. For example, the vibration of the top of a cabinet configuring the external appearance of the washing machine may be used for distinguishing among the stillness modes. Alternatively, the vibration of the other component such as a drum or a tub may be used.
The operation condition may include a washing condition related to a washing operation or a drying condition related to a drying operation. However, the operation condition preferably includes a dehydration condition related to a dehydration operation. This is because the rotation speed of the drum is highest and the vibration is large upon the dehydration operation.
Preferably, the dehydration condition may include the maximum rotation speed of the drum. That is, the maximum rotation speed of the drum upon the dehydration operation preferably varies depending on the stillness mode. For example, in a mode which requires a higher stillness degree, the maximum rotation speed of the drum is set to be relatively low.
Preferably, the maximum rotation speed of the drum may vary depending on the amount of laundry. When the amount of laundry is large in the same stillness mode, the maximum rotation speed of the drum is maintained to be low. This is because the vibration increases as the amount of laundry increases.
The dehydration condition may include a reference unbalance (UB) amount. That is, the reference UB amount may vary depending on the stillness mode.
For example, in a mode which requires a higher stillness degree, the reference UB amount may be set to be small. When the small reference UB amount is used, a main dehydration operation is performed only when an unbalance degree is low. Accordingly, the vibration is reduced in the main dehydration operation.
In another aspect of the present invention, a method of operating a washing machine includes a stillness mode selecting step of selecting any one of a plurality of stillness modes which are distinguished according to a stillness degree of an operation; and a stillness mode operating step of controlling and operating the washing machine according to an operation condition corresponding to the selected stillness mode.
It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
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 application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings:
FIGS. 1 and 2 are views explaining a conventional washing machine;
FIG. 3 is a view showing a washing machine according to the present invention;
FIG. 4 is an embodiment of a dehydration condition according to a stillness mode; and
FIGS. 5 to 7 are flowcharts illustrating embodiments of a method of operating a washing machine according to the present invention.
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. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.
FIG. 3 is a view showing an exemplary embodiment of a washing machine according to the present invention.
As shown, a control panel 3 having a display unit for displaying a residual time and input keys for allowing a user to selectively input a command signal related to an operation of the washing machine is provided at the front upper side of a washing machine 1 .
The control panel 3 includes a plurality of buttons 31 , a display window 32 , a light-emitting diode (LED) window 33 , and a rotary knob 50 . The buttons and the rotary knob 50 are input units for operating the washing machine. That is, when a washing time, a washing method, a dehydration method and a drying method are selected, the buttons and the rotary knob 50 are manipulated to input a washing course and time desired by the user.
A controller (not shown) controls the washing machine according to the above-described input condition to perform the washing operation, the drying operation or the dehydration operation.
The LED window 33 and the display window 32 notify the user of a variety of washing information, such as a washing state or a residual time, via ON/OFF and characters and symbols.
The washing machine includes two stillness modes. The operation condition varies depending on the stillness mode.
The control panel 3 includes a selection button 101 for selecting a second stillness mode between the two stillness modes. When the user selects the selection button 101 , the second selection mode is selected, and the controller controls the washing machine under the operation condition corresponding to the second selection mode.
A first stillness mode is set in a default mode. Accordingly, if the selection button 101 is not selected, the first stillness mode is automatically selected, and the controller controls the washing machine under the operation condition corresponding to the first stillness mode.
FIG. 4 shows a dehydration condition among operation conditions, similar to FIG. 2 . In FIG. 4 , a vertical axis shows the rotation speed of the drum in the dehydration operation and a horizontal axis shows a time. In FIG. 4 , a line {circle around ( 1 )} indicates the first stillness mode and a line {circle around ( 2 )} indicates the second stillness mode.
As shown, the maximum rotation speeds of the first stillness mode and the second stillness mode are different from each other in a main dehydration process.
When the second stillness mode is selected by selecting the selection button 101 on the control panel 3 , the dehydration operation is performed according to the line {circle around ( 2 )} in the graph shown in FIG. 4 . When the selection button 101 is not selected, the dehydration operation is automatically performed according to the line {circle around ( 1 )}.
Since the maximum rotation speed of the drum in the second stillness mode is smaller than that in the first stillness mode, the second stillness mode has a stillness degree higher than that of the first stillness mode.
Although not shown, a line {circle around ( 3 )} may be added to the graph shown in FIG. 4 . Depending on the amount of laundry, the dehydration operation may be performed according to any one of the line {circle around ( 2 )} and the line {circle around ( 3 )}. The maximum rotation speed of the drum of the line {circle around ( 3 )} is different from that of the line {circle around ( 2 )}.
For example, if the amount of laundry is small, the dehydration operation is performed according to the line {circle around ( 2 )} and, if the amount of laundry is large, the dehydration operation is performed according to the line {circle around ( 3 )} which has the maximum rotation speed lower than that of the line {circle around ( 2 )}.
FIG. 5 shows a flowchart illustrating the above-described operation.
When a washing mode is completed and is switched to a dehydration mode (S 11 ), the UB amount is detected (S 12 ) and the detected UB amount is compared with the reference UB amount set previously (S 13 ).
If the detected UB amount is larger than the reference UB amount, the dehydration operation is stopped (S 14 ) and the step S 12 of detecting the UB amount is performed again.
If the detected UB amount is equal to or smaller than the reference UB amount, a main dehydration operation is performed.
At this time, it is checked which of the stillness modes is selected (S 15 ) and the maximum rotation speed of the drum is determined according to the selected stillness mode (S 16 and S 17 ).
The rotation speed of the drum increases up to the maximum rotation speed and the main dehydration operation is performed (S 18 ).
FIG. 6 shows another embodiment of the present invention. In the present embodiment, a dehydration operation is performed using a reference UB amount which varies depending on a stillness mode.
First, when the mode is switched to the dehydration mode (S 21 ), the UB amount is detected (S 22 ).
It is checked which of the stillness modes is selected (S 23 ). If the first stillness mode is selected, a reference UB amount 1 is used (S 24 ) and, if the second stillness mode is selected, a reference UB amount 2 is used (S 26 ).
After the detected UB amount is compared with the reference UB amount (S 24 and S 26 ), the dehydration operation is stopped (S 25 and S 27 ) or the main dehydration operation is performed (S 28 ), similar to the above-described embodiment.
The reference UB amount 2 is set to be less than the first reference UB amount 1 . Accordingly, when the main dehydration operation starts, an unbalance degree of the second stillness mode is lower than that of the first stillness mode.
Since the unbalance degree is small in the second stillness mode, the second stillness mode has a stillness degree higher than that of the first stillness mode.
FIG. 7 shows another embodiment which is a combination of the above-described embodiments.
First, when the mode is switched to the dehydration operation (S 31 ), the UB amount is detected (S 32 ).
It is checked which of the stillness modes is selected (S 33 ). If the first stillness mode is selected, the reference UB amount 1 is used (S 34 ) and the maximum rotation speed of the drum in the main dehydration operation is determined to be rpm 1 (S 36 ).
If the second stillness mode is selected, the reference UB amount 2 is used (S 37 ) and the maximum rotation speed of the drum in the main dehydration operation is determined to be rpm 2 (S 39 ).
After the detected UB amount is compared with the reference UB amount (S 34 and S 37 ), the dehydration operation is stopped (S 35 and S 37 ) or the main dehydration operation is performed (S 40 ), similar to the above-described embodiment.
According to the present invention, it is possible to obtain a washing machine which operates in a stillness mode having a stillness degree higher than that of the conventional washing machine.
A user can select a desired stillness mode according to a use environment or situation. Since the washing machine can operate according to the desired stillness mode, it is possible to meet a variety of demands of consumers.
It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.
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Disclosed herein is a still operation of a washing machine, and more particularly, a washing machine which includes an operation condition of the washing machine in correspondence with each of a plurality of stillness modes and operates according to the operation condition corresponding to any one selected from the plurality of stillness modes. The washing machine includes a controller which, by the selection of any one of a plurality of stillness modes which are distinguished according to a stillness degree of an operation, controls the washing machine according to an operation condition corresponding to the selected stillness mode.
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BACKGROUND OF THE INVENTION
The present invention relates to an elevator supervision method and system which greatly simplify the components used in and the architecture of the safety chain but yet enhance the operating performance of an elevator.
Historically it has been standard practice within the elevator industry to strictly separate the collection of information for safety purposes from that for elevator control purposes. This is partly due to the fact that the elevator controller requires information at high precision and frequency regarding the car's position and speed, whereas the most important factor for the safety chain is that the information supplied to it is guaranteed as fail-safe. Accordingly, while the sensor technology used to supply the controller with information has improved dramatically over recent years, the sensors used in elevator safety chains are still based on relatively old “tried and trusted” mechanical or electromechanical principles with very restricted functionality. The conventional overspeed governor is set to actuate at a single predetermined overspeed value and the collection of safety-relevant positional information is restricted to the hoistway ends and the landing door zones.
Since the controller and the safety chain systems independently gather the same information to a certain extent, there has always been a partial redundancy in the collection of information within existing elevator installations.
There have been proposals to replace components of the safety chain, for example the conventional overspeed governors and the emergency limit switches at the hoistway ends, with more intelligent electronic or programmable sensors. Such a system has been described in WO-A1-03/011733 wherein a single-track of Manchester coding mounted along the entire elevator hoistway is read by sensors mounted on the car and provides the controller with very precise positional information. Furthermore, since it incorporates two identical sensors connected to two mutually supervising processors it fulfils the required parallel redundancy criterion to provide fail-safe safety chain information. However, it will be appreciated that this system is relatively expensive as it necessarily includes a redundant sensor and is therefore more appropriate to high-rise elevator applications than to low and medium-rise installations. Furthermore, since identical sensors are used to measure the same parameter it is inherent that they are more likely to fail at approximately the same time since they are susceptible to the same manufacturing tolerances and operating conditions.
SUMMARY OF THE INVENTION
It is the objective of the present invention to greatly simplify the components used in and the architecture of the safety chain but yet enhance the operating performance of an elevator by using more intelligent systems for the collection of hoistway information. This objective is achieved by providing a method and system for supervising the safety of an elevator having a car driven by driving means wherein a travel parameter of the car is sensed and continually compared with a similarly sensed travel parameter of the driving means. If the comparison shows a large deviation between the two parameters, an emergency stop is initiated. Otherwise one of the travel parameters is output as a verified signal. The verified signal is then compared with predetermined permitted values. If it lies outside the permitted range then an emergency stop is initiated. The travel parameters sensed for the car and the driving means can be one of the following physical quantities; position, speed or acceleration.
Since the verified signal is derived from the comparison of signals from two independent sensor systems, it satisfies current safety regulations.
Furthermore, since the two independent sensor systems monitor different parameters, there is an increased functionality; for example the method and system can easily determine deviations between the operation of the driving means and the travel of the car and initiate a safe reaction if appropriate.
The travel parameter of the car can be sensed by mounting a sensor on the car or, if an existing installation is to be modernized, the travel parameter of the car can be sensed by mounting a sensor on an overspeed governor.
Whereas the conventional overspeed governor has a single predetermined overspeed value, the current invention uses a registry of permitted values so that the overspeed value could be dependent on the position of the car within an elevator shaft for example.
Preferably the deceleration of the car is monitored immediately after every emergency stop. If the deceleration is below a specific value, a safety gear mounted on the car is activated to bring the car to a halt. In the conventional system, the safety gear is only activated at the predetermined overspeed value. So, for example, if the traction rope of an elevator installation were to break, the conventional system would release the safety gear to halt the car only after it has reached the relatively high overspeed limit. Understandably this frictional breaking the car against the guide rail by means of the safety gear at such high speeds can cause serious deterioration of the guide rails and more importantly exert a very uncomfortable impact on any passengers riding in the car.
Other features and advantages of the present invention will become apparent from the following description of the invention that refers to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is herein described by way of specific examples with reference to the accompanying drawings of which:
FIG. 1 is a schematic representation of the sensor systems employed in an elevator installation according to a first embodiment of the present invention;
FIG. 2 is a signal flow diagram showing how the signals derived from the sensor systems of FIG. 1 are processed to derive safety-relevant shaft information;
FIG. 3 is a schematic representation of the sensor systems employed in an elevator installation according to a second embodiment of the present invention;
FIG. 4 is a signal flow diagram showing how the signals derived from the sensor systems of FIG. 3 are processed to derive safety-relevant shaft information;
FIG. 5 is a schematic representation of the sensor systems employed in an elevator installation according to a further embodiment of the present invention;
FIG. 6 is a signal flow diagram showing how the signals derived from the sensor systems of FIG. 5 are processed to derive safety-relevant shaft information; and
FIG. 7 is an overview of the general system architecture of the embodiments of FIGS. 1 to 6 .
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates an elevator installation according to a first embodiment of the invention. The installation comprises a car 2 movable vertically along guide rails (not shown) arranged within a hoistway 4 . The car 2 is interconnected with a counterweight 8 by a rope or belt 10 which is supported and driven by a traction sheave 16 mounted on an output shaft of a motor 12 . The motor 12 and thereby the movement of the car 4 is controlled by an elevator controller 11 . Passengers are delivered to their desired floors through landing doors 6 installed at regular intervals along the hoistway 4 . The traction sheave 16 , the motor 12 and the controller 11 can be mounted in a separate machine room located above the hoistway 4 or alternatively within an upper region of the hoistway 4 .
As with any conventional installation, the position of the car 4 within the shaft 4 is of vital importance to the controller 11 . For that purpose, equipment for producing shaft information is necessary. In the present example such equipment consists of an absolute position encoder 18 mounted on the car 4 which is in continual driving engagement with a toothed belt 20 tensioned over the entire shaft height. Such a system has been previously described in EP-B1-1278693 and further description here is therefore thought to be unnecessary. A magnet 24 is mounted at each landing level of the shaft 4 principally for calibration purposes. On an initial learning run the magnets 24 activate a magnetic detector 22 mounted on the car 4 and thereby the corresponding positions recorded by the absolute position encoder 18 are registered as landing door 6 positions for the installation. As the building settles, the magnets 24 and the magnetic detector 22 are used to readjust these registered positions accordingly. All non-safety-relevant shaft information required by the controller 11 can then be derived directly from the absolute position encoder 18 .
A conventional installation would further include an overspeed governor to mechanically actuate safety gear 28 attached to the car 4 if the car 4 travels above a predetermined speed. As is apparent from FIG. 1 , this is not included in the present embodiment. Instead, an incremental pulse generator 26 is provided on the traction sheave 26 to continually detect the speed of the traction sheave. Alternatively the incremental pulse generator 26 could be mounted on the shaft of the motor 12 . Indeed many motors 12 used in these elevator applications already incorporate an incremental pulse generator 26 to feedback speed and rotor position information to a frequency converter powering the motor 12 . The incremental pulse generator 26 provides accurate information on the rotation of the traction sheave 16 . A pulse is generated every time the traction sheave 16 moves through a certain angle, and accordingly the frequency of the pulses provides a precise indication of the rotational speed of the traction sheave 12 .
The principle behind the present embodiment is to use the incremental pulse generator 26 , the absolute position encoder 18 and the magnetic detector 22 (the three independent, single-channel sensor systems) to provide all the required shaft information, not just the non-safety-relevant shaft information.
As shown specifically in FIG. 2 , the signals derived from the three independent, single-channel sensor systems 18 , 22 and 26 are initially supplied to a data verification unit 30 . Therein the signals from the incremental pulse generator 26 and the absolute position encoder 18 are submitted to a consistency examination in modules 32 to ensure that they are not erratic. If either of the signals is determined to be erratic, then the corresponding module 32 initiates an emergency stop by de-energizing the motor 12 and actuating a brake 14 connected to the motor 12 . The module 32 may also provide an error signal to indicate that the sensor it is examining is faulty.
A position comparator 34 receives as its inputs the positional signal X SM from the magnetic detector 22 and an examined position signal X ABS derived from the absolute position encoder 18 . Furthermore, the examined speed signal X′ IG derived from the incremental pulse generator 26 is fed through an integrator 33 and the resulting signal X IG is also input to the position comparator 34 .
Within the position comparator 34 , the position signal X IG derived from the incremental pulse generator 26 and the position signal X ABS from the absolute position encoder 18 are calibrated against the positional signal X SM from the magnetic detector 22 . The main difference between the incremental pulse generator 26 and the absolute position encoder 18 is that whereas the incremental pulse generator 26 produces a standard pulse on every increment, the absolute position encoder 18 produces a specific, unique bit pattern for every angle increment. This “absolute” value does not require a reference procedure as with the incremental pulse generator 26 . Hence, although the shaft magnets 24 and the magnetic detector 22 are used to readjust the registered landing door 6 positions as recorded by the absolute position encoder 18 , once the building has settled it will be understood that the absolute position encoder 18 knows all door positions with a high degree of accurately and no further calibration with the magnetic detector 22 is therefore required. The incremental pulse generator 26 on the other hand requires continual calibration with the magnetic detector 22 because the magnetic detector 22 indicates car position whereas the signal from incremental pulse generator 26 is used to indicate traction sheave position and any slippage of the rope or band 10 in the traction sheave 16 will automatically throw the incremental pulse generator 26 out of calibration with the actual car position. This calibration is carried out in the position comparator 34 each time the magnetic detector 22 on the car 4 senses a shaft magnet 24 .
Other than the calibration processes outlined above, the main purpose of the position comparator 34 is to continually compare the position signal X IG derived from the incremental pulse generator 26 with the corresponding position signal X ABS from the absolute position encoder 18 . If the two signals differ by for example one percent or more of the entire shaft height HQ, then an emergency stop is initiated by de-energizing the motor 12 and actuating the brake 14 . In some rare instances, for example if the rope 10 has broken, this emergency stop will not be sufficient to stop the car 4 . In such situations the position comparator 34 monitors acceleration signals X″ IG and X″ ABS derived by feeding the signals from the incremental pulse generator 26 and the absolute position encoder 18 through differentiators 35 to ensure that the car 2 decelerates by at least 0.7 m/s 2 . If not, the position comparator 34 electrically triggers the release of the safety gear 28 (shown in FIG. 1 ) mounted on the car 2 so that it frictionally engages with the guide rails and thereby brings the car 4 to a halt. The electrical release of an elevator safety gear is well known in the art as exemplified in EP-B1-0508403 and EP-B1-1088782.
Otherwise the condition represented in the equation below is satisfied and the signal X ABS from the absolute position encoder 18 having been verified against an independent sensor signal X IG can be used as a safety-relevant position signal
X
ABS
-
X
IG
HQ
<
1
%
Although the following description details specifically how the safety-relevant position signal X is used to supervise the safety of the elevator, it will be appreciated that the signal X can be, and is, used additionally to provide the controller 11 with the required hoistway information.
The data verification unit 30 also includes a speed comparator 36 wherein the examined speed signal X′ IG derived from the incremental pulse generator 26 is taken as an input. The examined signal from the absolute position encoder 18 is fed through a differentiator 35 to provide a further input X′ ABS representing speed. The two speed values X′ IG and X′ ABS are continually compared with each other in the speed comparator 36 and should they deviate by more than five percent an emergency stop is initiated by de-energizing the motor 12 and actuating the brake 14 . At approximately two seconds after initiating the emergency stop, the speed comparator 36 releases the safety gear 28 .
Otherwise the conditions represented in both of the equations below are satisfied and the signal X′ ABS derived from the absolute position encoder 18 having been verified against an independent sensor signal X′ IG can be used as a safety-relevant speed signal X′.
X
ABS
′
-
X
IG
′
X
ABS
′
<
5
%
AND
X
IG
′
-
X
ABS
′
X
IG
′
<
5
%
As with the safety-relevant position signal X, the safety-relevant speed signal X′ can be fed to the controller 11 to provide the required hoistway information as well as being used to supervise the safety of the elevator.
The signal X SM from the magnetic detector 22 is fed into a safety supervisory unit 38 together with the safety-relevant position signal X from the position comparator 34 and the safety-relevant speed signal X′ from the speed comparator 34 . These safety-relevant signals X and X′ are continually compared with nominal values stored in position and overspeed registries 39 . If, for example, the safety-relevant speed signal X′ exceeds the nominal overspeed value, the safety supervisory unit 38 can initiate an appropriate reaction. Additionally, the safety supervisory unit 38 is supplied with conventional information from door contacts monitoring the condition of the landing doors 6 and from the car door controller or car door contacts. If an unsafe condition occurs during operation of the elevator the safety supervisory unit 38 can initiate an emergency stop by de-energizing the motor 12 and actuating the brake 14 and, if necessary, releasing the safety gear 28 to bring the car 4 to a halt.
During installation, the elevator car 4 is sent on a learning journey during which the technician moves the car 4 at a very low speed (e.g. 0.3 m/s). As the car 4 moves past the landing doors 6 , the associated shaft magnets 24 are detected by the car mounted magnetic sensor 22 and the safety supervisory unit 38 acknowledges each of these positions by registering the corresponding verified position signal X derived from the absolute position encoder 18 into the appropriate registry 38 . Furthermore, a zone of ±20 cm from each magnet 24 is registered as the door opening zone in which the doors 6 can safely commence opening during normal operating conditions of the elevator installation. The uppermost and lowermost magnets 24 mark the extremes in the car travel path and from these the overall travel distance or shaft height HQ can be calculated. The maximum permissible speed curves (maximum nominal speed depending on the position of the car 2 ) can then be defined and recorded into the appropriate registry 38 .
As mentioned previously, the continual comparison of signals derived from the three sensor systems within the data verification unit 30 as well as the consistency examination of the signals from the incremental pulse generator 26 and the absolute position encoder 18 ensure that a fault with any of the sensor systems can be identified quickly and an emergency stop initiated. Furthermore, if the data verification unit 30 detects a significant amount of rope slippage by means of the comparators 34 and 36 , it immediately initiates an emergency stop. If the emergency stop fails to retard the car 2 sufficiently, the position comparator releases the safety gear 28 .
The safety supervisory unit 38 detects faults in the operation of the controller 11 . If the controller permits the car 2 to travel at too great a speed, a comparison within the safety supervisory unit 38 of the safety-relevant speed signal X′ from the data verification unit 30 with the overspeed registry 39 will identify the fault and the safety supervisory unit 38 can initiate an emergency stop.
FIGS. 3 and 4 show a second embodiment of the present invention in which the shaft magnets 24 and magnetic detector 22 of the previous embodiment have been replaced with conventional zonal flags 44 symmetrically arranged 120 mm above and below each landing floor level together with an optical reader 42 mounted on the car 2 to detect the flags 44 . Additionally, the absolute position encoder 18 has been replaced by an accelerometer 40 mounted on the car 4 .
Within the data verification unit 46 of the present embodiment, the signal X IG derived from the incremental pulse generator 26 is compared with and calibrated against the position signal X ZF from the optical reader 42 . The distance ΔX ZF between successive flags 44 is recorded and compared to the corresponding distance ΔX IG derived from the incremental pulse generator 26 . If this comparison gives rise to a deviation in the two distances of two percent or more then an emergency stop is initiated by de-energizing the motor 12 and actuating the brake 14 . Furthermore, the deceleration of system is monitored after the emergency stop has been initiated to ensure that (at least one of) the signals derived from both the incremental pulse generator 26 and the accelerometer 18 show a deceleration of at least 0.7 m/s 2 , indicating that the emergency stop is sufficient to bring the car 2 to a halt. If not, safety gear 28 (shown in FIG. 1 ) mounted on the car 2 is released to frictionally engage with the guide rails and thereby bring the car 4 to a halt.
Otherwise the condition represented in the equation below is satisfied and the signal X IG derived from the incremental pulse generator 26 having been verified against an independent sensor signal X ZF can be used as a safety-relevant position signal X.
Δ
X
ZF
-
Δ
X
IG
Δ
X
ZF
<
2
%
The data verification unit 46 also includes a speed comparator 50 wherein the examined speed signal X′ IG derived from the incremental pulse generator 26 is taken as an input. The signal X″ Acc from the accelerometer 40 is fed through an integrator 33 to provide a further input X′ Acc representing the vertical speed of the car 2 . The two speed values X′ IG and X′ Acc are continually compared with each other in the speed comparator 50 and should they deviate by more than five percent an emergency stop is initiated by de-energizing the motor 12 and actuating a brake 14 . As in the previous embodiment, At approximately two seconds after initiating the emergency stop, the speed comparator 36 releases the safety gear 28 .
Otherwise the conditions represented in both of the equations below are satisfied and the signal X′ IG derived from the incremental pulse generator 26 having been verified against an independent sensor signal X′ Acc can be used as a safety-relevant speed signal X′.
X
Acc
′
-
X
IG
′
X
Acc
′
<
5
%
AND
X
IG
′
-
X
Acc
′
X
IG
′
<
5
%
The acceleration signal X″ Acc from the accelerometer 40 is fed into a safety supervisory unit 52 together with the safety-relevant position signal X from the position comparator 48 and the safety-relevant speed signal X′ from the speed comparator 50 . If an unsafe condition occurs during operation of the elevator the safety supervisory unit 38 can initiate an emergency stop by de-energizing the motor 12 and actuating the brake 14 and, if necessary, activate the safety gear 28 to bring the car 4 to a halt.
FIGS. 5 and 6 show an existing elevator installation which has been modified in accordance with yet a further embodiment of the present invention. The existing installation includes a conventional overspeed governor which is an established and reliable means of sensing the speed of the elevator car 2 . The governor has a governor rope or cable 54 connected to the car 2 and deflected by means of an upper pulley 56 and a lower pulley 58 . In the conventional system, the upper pulley 56 would house the centrifugal switches set to activate at a predetermined overspeed value for the car 2 . In the present embodiment these switches are replaced by an incremental pulse generator 60 mounted on the upper pulley 56 .
The processing of the information received from the pulley incremental pulse generator 60 , the traction sheave incremental pulse generator 26 and the optical reader 42 is the same as in the previous embodiments in that the signals are verified and compared in a data verification unit 62 to supply a safety-relevant position signal X and a safety-relevant speed signal X′ to a safety supervisory unit 68 .
FIG. 7 is an overview of the system architecture of the previously described embodiments. Three independent single-channel sensor systems are connected to a safety monitoring unit which in the embodiments hitherto described comprises a data verification unit and a safety supervision unit. The safety monitoring unit derives safety-relevant positional and speed information which it uses to bring the elevator into a safe condition by de-energizing the motor, activating the brake and/or activating the safety gear.
The brake need not be mounted on the motor, but could form a partial member of the safety gear. If the safety gear consists of four modules, then normal braking could for example be instigated by actuating two of the four modules.
In all of the described embodiments of the invention it will be understood that the signals derived from the data verification units and the safety supervision units can be used to provide the necessary shaft information for the elevator controller 11 as well as performing the safety-relevant objectives for the elevator.
Furthermore, it will be appreciated that the invention is equally applicable to hydraulic elevator installations as to traction installations.
Although the present invention has been described in relation to particular embodiments thereof, many other variations and modifications and other uses will 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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A method and system for supervising the safety of an elevator having a car driven by a drive within a hoistway wherein a travel parameter (X ABS ,X″ Acc ,X′ IGB ) of the car is sensed and continually compared with a similarly sensed travel parameter (X′ IG ) of the drive. If the comparison shows a large deviation between the two parameters, an emergency stop is initiated. Otherwise one of the travel parameters (X ABS ,X″ Acc X′ IGB ; X′ IG ) is output as a verified signal (X;X′). The verified signal is then compared with predetermined permitted values. If it lies outside the permitted range then an emergency stop is initiated.
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FIELD OF THE INVENTION
This invention relates generally to heat transfer, and particularly concerns a novel direct contact heat exchanger which effectively recovers useful sensible heat and latent heat from a combustion product exhaust stream and which may be advantageously incorporated into a heating system such as a warm-air furnace system to thereby improve system overall heat recovery efficiency.
BACKGROUND OF THE INVENTION
Warm-air furnace systems are well-known and generally recover useful sensible heat from system combustion product gases using at least one or more system elements which extract varying degrees of available heat. In some instances the well-known systems recover sensible heat from combustion product gases flowing through system combustor elements or in a system firepot element submerged in the system stream of warm-air. Also, such systems may utilize one or more heat-exchanger or heat-exchanger-like elements to obtain additional sensible heat from the system combustion product gases for transfer to the system stream of warm-air. Such systems, however, have not been known to advantageously extract available latent heat from the flow of system combustion product gases and utilize that heat to pre-heat the system airflow stream prior to the airflow stream being additionally heated by the system primary sensible heat source or sources.
For examples of known heating systems which do recover latent heat from system combustion product gases but which do not utilize that heat for airstream pre-heat purposes see U.S. Pat. No. 4,340,572 issued in the name of Ben-Shmuel et al., U.S. Pat. No. 4,799,941 issued in the name of Westermark, and U.S. Pat. No. 4,919,085 issued in the name of Kaisha.
Also, conventional warm-air furnace systems wherein latent heat is recovered from combustion product gases to increase system thermal efficiency are well-known but such systems do not advantageously utilize a direct contact condensing heat exchanger for that purpose. By way of example refer to the Amana "Air Command 90" furnace system.
SUMMARY OF THE INVENTION
The present invention may be combined with several other apparatus elements to provide useful heat to a warm-air furnace system airflow stream which is normally received in a relatively cool condition at a return air inlet and discharged in a heated condition at the system supply air outlet. Such airflow stream is first heated (pre-heated) at a secondary heat exchanger which, by bubbling the combustion product gases from the primary heat exchanger directly through a bubble distributor submerged in a water medium, recovers both sensible heat and latent heat from such combustion product gases at higher efficiencies for transfer to the furnace system airflow stream. Afterwards, the airflow stream is further heated to its desired exchanger element, such as a system burner element, or system pulsed combustor element, or system tubular tailpipe element, submerged in the airflow stream in down-stream relation to the system secondary heat exchanger element. The referenced secondary direct contact condensing heat exchanger is provided with an initial charge of water medium which is supplemented from cycle to cycle automatically during operation of the warm-air furnace system by water condensed from the combustion product gases when such gases are finely divided into small bubbles for direct contact with and cooling by the water medium charge. Such finely divided combustion product gases are bubbled through the water medium at a relatively low static pressure differential (e.g., 1 to 3 inches of water) and are then separated from the medium for discharge from the system to the outdoors in an essentially water-free but saturated and relatively cool condition. Also, the secondary heat exchanger is constructed in a manner whereby convection and bubbling forces automatically recirculate the water medium heated by combustion product gas bubbles in a continuous loop principally comprised of heat exchanger tubes or tube and fin elements that are submerged in the system airflow stream and that transfer the acquired combustion product gas sensible and latent heats to the airflow stream. The magnitude of the desired relatively low hydrostatic pressure head differential through which combustion product gases are bubbled is essentially controlled by proper design and placement of the system bubble distributor and the secondary heat-exchanger water medium overflow discharge element relative to each other and relative to the physical locations of the included heat-exchanger tubes or tube and fin elements.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic elevational view of a preferred embodiment of the warm-air furnace system incorporating the direct contact condensing heat-exchanger of this invention.
FIG. 2 is a schematic enlarged view of the direct contact heat-exchanger element with submerged bubble distributor incorporated in the system of FIG. 1.
FIG. 3 is a schematic elevational view of another embodiment of a warm-air furnace system incorporation another form of direct contact condensing heat exchanger condensing of this invention.
FIG. 4 is a schematic enlarged view of the direct contact condensing heat-exchanger element with submerged bubble distributor incorporated in the system of FIG. 3.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 schematically illustrates a warm-air furnace system 10 constructed in accordance with the present invention. System 10 has an outer casing or housing 12 which in part functions as a conduit for the system airflow stream which is received as return air at inlet opening/filter combination 14 and which, after heating within casing 12, is discharged at outlet opening 16 as warmed supply air. In a typical residential-type warm-air furnace system 10 the airstream received at inlet opening 14 has a temperature in the range of 65° F. to 70° F.; heated air discharged through outlet opening 16 typically has a temperature in the range of 120° F. to 160° F. The prime mover for the system airflow stream is a conventional electric motor-driven centrifugal blower 18 located in the compartment area defined by housing 12 and the compartment wall designated 20.
Also located within housing 12 is a primary heat-exchanger 22, a secondary heat-exchanger 24, a burner assembly 26, and an induced draft exhaust fan or blower 28. Fuel, preferably natural gas, propane, butane, or the like, is burned by the burner assembly 26 using combustion air induced from the atmosphere. The combustion product gases produced by burner assembly 26, which alternatively may be a conventional pulsed combustor, are preferably introduced into heat-exchanger 22 by induction due to the suction effect of induced draft exhaust blower 28.
In the FIG. 1 embodiment, heat-exchanger 22 is comprised of serpentine-like metal tube elements 30 and 32 which are joined together through a header 34 mounted on compartment wall 36. During furnace system operation the combustion product gases flowed into tube 30 may have a typical temperature to as high as 2,000° F. to 2,500° F. Sufficient tube surface area is provided in the primary heat-exchanger tubes 30 and 32 to cool the combustion product gases to a temperature preferably no greater than approximately 450° F. to 500° F. at the point such gases are flowed into the header 40 and bubble distributor of secondary heat-exchanger 24. Tube elements 30 and 32, and header 34, are preferably made of a conventional corrosion-resistant alloy metal such as Type 316 or Type 409 stainless steel.
Secondary heat-exchanger 24, which is located upstream of primary heat-exchanger 22 relative to system direction of air flow, receives the combustion product gases at its inlet header element 40. Secondary heat-exchanger 24 is further comprised of an outlet header/separator element 42 which is cooperatively joined to header element 40 by a bank 44 of tube elements 46 and 47 (FIG. 2) which may or may not be combined with metal fin elements 48 (also FIG. 2) depending upon the adequacy of tube heat transfer surface. Whereas heat-exchanger 22 extracts only sensible heat from the system combustion product gases, secondary heat-exchanger 24 recovers both sensible heat and latent heat from these gases because of its improved heat transfer capability throughout a relatively lower gas temperature range. Normally, the maximum temperature obtained in heat-exchanger 24 is no greater than approximately 120° F. and preferably no more than approximately 100° F. to 110° F. at the point of gas/water-medium separation which occurs in header/separator element 42. The obtained water medium temperature should be below the dewpoint temperature of the combustion product gas mixture produced by burner assembly 26.
As shown in FIG. 1, system 10 also is provided with an overflow drain element 50 and with a conduit 52 which directs combustion product gases separated at outlet header/separator 42 to inlet 54 of induced draft blower assembly 28. Outlet 56 of blower assembly 28 is normally vented to the exterior atmosphere through a plastic resin pipe.
Referring to FIG. 2, tube 32 of heat-exchanger 22 terminates interiorly of heat-exchanger header 40 in the form of a horizontally-oriented bubble distributor section (32) and is provided with a plurality of small perforations or holes in the distributor section to permit combustion product gases to escape from within tube 32 in finely divided bubble form and into direct contact with the water heat transfer medium 60 which is initially charged into element 24. The hydrostatic pressure differential encountered at the bubble distributor perforations is preferably no more than approximately 1-3 inches of water. In one actual embodiment of bubble distributor section 32 we provided approximately 80 perforations of approximately 1/8 inch diameter essentially uniformly spaced apart over the effective horizontal length of the section.
The released small gas bubbles flow vertically upwardly through the water heat transfer medium 60 and produce a surging slug flow or plug of liquid and gas through the upper row of tube elements 46. The so-flowed gas bubbles give up both sensible heat and latent heat to the heat transfer process and are separated from medium 60 at is upper surface 62 during operation of the furnace system. The liquid recirculates from upper header 42 to the lower header 40 through the lower row of tube elements 47. The positioning of surface 62 is controlled by the positioning of the inlet of drain tube element 50 to produce the desired flow characteristics and the maximum hydrostatic head (e.g., 1 to 3 inches of water) between the level of the bubble-forming perforations of the generally horizontal bubble distributor tube 32 within inlet header 40 and the upper level 62 of medium 60 during system activation. In one embodiment of heat-exchanger 24 an angle of inclination of tubes 46 and 47 relative to horizontal of approximately 10° was adequate to achieve desired heat transfer and yet provide for proper bubbling and water recirculation as well as ready gas separation from medium 60 within header/separator element 42. During such heat transfer and separation processing a continuous loop-like recirculation of medium 60 occurs within heat-exchanger 24 with medium flow being in the directions shown in FIG. 2. In constructing heat-exchanger 24 we suggest use of a molded high-temperature rigid resin material for forming header element 40 and use of a molded relatively lower-temperature rigid resin material for forming header/separator element 42. Tube elements 46 and 47 may be fabricated of an aluminum metal alloy or other suitable material and pressure expanded into fin elements 48 to form a tube-fin bank 44 and tube-header contacting relationships.
FIG. 3 schematically illustrates a warm-air furnace system alternate embodiment 70 which also utilizes the present invention. Those elements which are in form and function substantially similar to like components of system 10 are identified by the same reference numerals used in FIGS. 1 and 2. In the FIG. 3 scheme, primary heat-exchanger 22 is comprised of conventional clamshell-type heat transfer elements 72 through which the combustion product gases generated by burners 26 are flowed to and through header element 74 to the bubble distributor 32 located in the baffled inlet header/separator element 76 of heat exchanger 24. The baffle in heat-exchanger 24 is designated as 79 in FIG. 4. Heat-exchanger 24 of FIG. 3 is comprised of a vertical or near-vertical bank 78 of tube elements 80 (FIG. 4) which may or may not be combined with metal fin elements 82 (also FIG. 4). However, the tube bank 78 could be arranged at any angle between horizontal and vertical, although the inlet header 76 would remain in approximately the position shown in FIGS. 3 and 4. A lower header 84 interconnects the lower extremes of tube elements 80, although U-bends could be used on each tube. Again, and as in the case of the FIGS. 1 and 2 embodiment, system 70 functions to transfer sensible heat and latent heat from the system stream of combustion product gases to the system airflow stream with an improved degree of heat or energy recovery (thermal efficiency), and achieves such through the bubbling of finely divided combustion product gases through the initial charge of water heat transfer medium 60 within the system secondary heat exchanger 24. Also, in the FIG. 3 system embodiment 70 primary heat-exchanger 22 and secondary heat-exchanger 24 function in an airstream parallel airflow relationship relative to each other, rather than in an upstream-downstream series relationship as in FIG. 1.
In the FIG. 2 arrangement the gas bubbles flow from the submerged bubble distributor section, and both liquid and gas circulate through the upper row or tier of heat-exchanger heat transfer tube elements. In the FIG. 4 arrangement the gas bubbles also flow from the submerged distributor section, but the attendant bubble-lift action in the outlet header causes only the liquid to circulate through the different rows or tiers of heat transfer tube elements 80, which may be oriented at any angle between vertical and horizontal. In both designs, however, rapid heat transfer occurs as the bubbles form because the hot gases are in direct contact with heat-transfer medium 60.
Although two preferred embodiments of the invention have been herein described, it will be understood that various changes and modifications in the illustrated described structure can be effected without departure from the basic principles of the invention. Changes and modifications of this type are therefore deemed to be circumscribed by the spirit and scope of this invention defined by the appended claims or by a reasonable equivalence.
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A direct contact condensing heat-exchanger is provided with a water heat transfer medium in which combustion product gases are dispersed in finely divided bubble form against a relatively low hydrostatic pressure differential for efficient sensible heat and latent heat recovery purposes. In one actual application, a warm-air furnace system having a burner that produces combustion product gases as a heat source is provided with the novel direct contact condensing heat-exchanger as a seondary heat-exchanger that advantageously recovers both sensible heat and latent heat from the combustion product gases.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an apparatus for driving a solid state image pickup device used in a color video camera provided with a single image pickup device.
2. Related Background Art
As the light-receiving accumulation modes of a solid state image pickup device used in a video camera, there are known the frame accumulation mode in which signal charges are accumulated in a charge accumulation type photoelectric converting element for one frame period (1/30 sec.) and the field accumulation mode in which signal charges are accumulated in a charge accumulation type photoelectric converting element for one field period (1/60 sec.).
FIG. 1 of the accompanying drawings, is a schematic view of an interline transfer CCD known as a solid state image pickup device, and arrows therein indicate the movement of signal charges from light-receiving portions 1 to vertical transfer portions 2 in the frame accumulation mode.
That is, solid-line arrows indicate the movement of signal charges in odd fields, and broken-line arrows indicate the movement of signal charges in even fields, and further, φ1-φ4 designate the four-phase driving signal electrodes of a vertical transfer CCD. A horizontal transfer portion 33 is a two-phase CCD and is driven by a horizontal transfer pulse applied to electrodes φ5 and φ6. The charges transferred by the horizontal transfer portion 33 are put out to the outside through an amplifier 34.
The driving in the frame accumulation mode is shown in the time chart of FIG. 2 of the accompanying drawings.
In FIG. 2, a frame synchronizing signal FLD is at a high level (hereinafter referred to as H level) for a period of time substantially corresponding to the transfer period of charges accumulated in the odd fields and at a low level (hereinafter referred to as L level) for a period of time substantially corresponding to the transfer period of charges accumulated in the even fields. V.BLK is a vertical blanking signal, and the period during which V.BLK is at L level is a vertical blanking period. Further, V1-V4 are electrode voltages corresponding to the transfer electrodes φ1-φ4.
As is apparent from FIG. 2, in the case of the frame accumulation mode, the voltage Vl of the electrode φ1 assumes the highest one of three levels at the timing of times T2, T4, ..., and as indicated by solid-line arrows in FIG. 1, the signal charges of the odd fields are transferred from the light-receiving portions 1 to the vertical transfer portions 2, whereafter they are read out as video signals. On the other hand, the voltage V3 of the electrode φ3 assumes the highest one of three levels at the timing of times T1, T3, ..., and as indicated by broken-line arrows in FIG. 1, the signal charges of the even fields are transferred from the light-receiving portions 1 to the vertical transfer portions 2 and are likewise read out as video signals.
Accordingly, in such driving by the frame accumulation mode, the accumulation time of the signal charges of each field is 1/30 sec. However, each of the areas in V1-V4 of FIG. 2 in which two oblique lines intersect each other indicate a period of time during which a predetermined synchronous transfer pulse is generated.
However, in the driving by the frame accumulation mode, when a moving object is photographed, the video signals of the odd fields and the even fields overlap each other by one field and therefore, an unpleasant field afterimage is created.
In contrast, in the driving by the field accumulation mode wherein signal charges are accumulated in one picture element for one field period (1/60 sec.), the signal charges of all picture elements are read out for each field and the picture element signals of two horizontal lines vertically adjacent to each other are compositely read out and therefore, no field afterimage is created. Here, the light-receiving portions 1 are charge accumulation type photoelectric converting elements.
FIG. 3 of the accompanying drawings shows the movement of signal charges from the light-receiving portions 1 to the vertical transfer portions 2 by the field accumulation mode, for example, in an interline transfer CCD, and FIG. 4 of the accompanying drawings shows the timing chart thereof.
First, in the case of the odd fields, at the timing of times T2, T4, ... of FIG. 4, the signal charges of the light-receiving portions 1 of two adjacent horizontal lines which provide the odd fields are added together in the vertical transfer portions as indicated by solid-line arrows in FIG. 3, and in the case of the even fields, at the timing of times T1, T3, ... of FIG. 4, the signal charges of the light-receiving portions 1 of two adjacent horizontal lines which provide the even fields are added together in the vertical transfer portions 2 as indicated by broken-line arrows in FIG. 3 and are read out.
Accordingly, the signal charges of all picture elements are read out for each field and therefore, the accumulation time of the signal charges is 1/60 sec. and no field afterimage is created.
Now, the driving method by the field accumulation mode wherein the signal charges of two horizontal lines are combined together in this manner and video signals are read out, whereby the accumulation time of the signal charges is 1/60 sec. poses no problem even if the signal charges of two horizontal lines are combined together where black-and-white video signals and video color signals are to be obtained by the use of complementary color filters comprising cyan, magenta and yellow, and also permits separation of color information, but is inferior to primary color filters in the S/N ratio of color signals and color reproducibility. Also, stripe-like filters using primary colors cannot sufficiently obtain brightness signals and are inferior in resolution. On the other hand, where color video signals are to be obtained by the use of other primary color filters (for example, a primary color mosaic filter) than stripe-like primary color filters, the presence of the process of combining and reading out the signals of two horizontal lines gives rise to color mixture and such filters cannot be used and after all, only the driving by the frame accumulation mode can be applied, and this has led to the disadvantage that a field afterimage is created. This will hereinafter be described in more detail.
Consider a single-plate color television camera using a single interline transfer CCD having attached thereto other primary color filters than stripe-like primary color filters. Taking as an example a primary color filter of such an arrangement as shown in FIG. 5 of the accompanying drawings, each of light-receiving portions 1 has applied thereto color coatings indicated by R, B and G.
As is apparent from FIG. 5, in the read-out of even fields by the field accumulation mode, three primary colors of R, G and B signals are added together in the vertical transfer portions without any problem and without color mixture, but in the case of the odd fields, R signal and B signal are mixed in the vertical transfer portions and therefore, in this case, it becomes impossible to obtain R and B signals and after all, when use is made of other primary color filters than stripe-like primary color filters, it has been impossible to obtain color video signals in the driving method by the field accumulation mode.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an apparatus for driving a solid state image pickup device which is capable of driving by the field accumulation mode and can obtain video color signals free of afterimages.
To achieve the above object, in the present invention, the driving by the frame accumulation mode in which during each frame period, the signal charges of light-receiving portions are intactly transferred to vertical transfer portions and read out as video signals is the basis and in addition to this, prior to the transfer of the signal charges from the light-receiving portions effected during each frame period, unnecessary charges are transferred from the light-receiving portions to the vertical transfer portions within the vertical blanking period one field before and the unnecessary charges are swept out of the vertical transfer portions by a high-speed transferring operation, whereby overlapping of the accumulations of the signal charges of odd fields and even fields is prevented to thereby eliminate any field afterimage and obtain a video color signal in which the accumulation time is substantially 1/60 sec.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view schematically showing the movement of signal charges by the frame accumulation mode according to the prior art and an interline transfer CCD.
FIG. 2 is a timing chart showing the driving by the frame accumulation mode according to the prior art.
FIG. 3 is a plan view showing the movement of signal charges by the field accumulation mode according to the prior art.
FIG. 4 is a timing chart showing the driving by the field accumulation mode according to the prior art.
FIG. 5 is a plan view of an interline transfer CCD provided with primary color filters.
FIG. 6 is a time chart illustrating the principle of the present invention.
FIG. 7 is a block diagram of an embodiment of the present invention.
FIGS. 8 and 9 are time charts showing the operation of an embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The driving of a solid state image pickup element shown in the timing chart of FIG. 6, like the driving by the frame accumulation mode of the interline transfer CCD shown in FIG. 1, is based on the operation of transferring a signal charge from each light-receiving portion 1 to each vertical transfer portion 2 during each frame period per signal charge of each field as shown in the timing chart of FIG. 2 without adding the signal charges of the light-receiving portions 1.
With such driving by the frame accumulation mode as the premise, in the driving of the present invention, in both of odd and even fields, the signal charges of the light-receiving portions 1 are once transferred as unnecessary charges, to the vertical transfer portions 2 during the vertical blanking period which is one field before the timing at which read-out of the signal charges is effected from the light-receiving portions to the vertical transfer portions during each frame period and the signal charges are swept out of the vertical transfer portions by high-speed sweeping-out operation, whereby the driving by the field accumulation mode which is substantially 1/60 sec. is realized.
This driving principle of the present invention will hereinafter be described with reference to the timing chart of FIG. 6.
In the timing chart of FIG. 6, V10-V40 represent electrode voltages corresponding to electrodes φ1-φ4 for transferring and driving a vertical transfer CCD.
Signal charges are first transferred from the light-receiving portions 1 to the vertical transfer portions 2 during each frame period. That is, with regard to the odd fields, the electrode voltage V10 of the electrode φ1 of the vertical transfer portion corresponding to the light-receiving portion 1 of the odd field is rendered into the highest one of three levels at the timing of times T4, T8, ..., whereby the signal charges of the light-receiving portions 1 are transferred to the vertical transfer portions 2, whereafter they are read out as video signals by the normal operation durative for the odd field time. With regard also to the even fields, the electrode voltage V30 of the electrode φ3 of the vertical transfer portion 2 corresponding to the light-receiving portion 1 of the even field is rendered into the highest one of three levels at the timing of each frame period which is times T2, T6, ..., whereby the signal charges of the even fields are read out from the light-receiving portions 1 to the vertical transfer portions 2 and are read out as video signals by the normal operation for the even field time thereafter.
In addition to such read-out of the video signal during each frame period corresponding to each field, in the driving apparatus of the present invention, prior to the transfer and read-out of the signal charge of the odd field, for example, at time T4, the electrode voltage V10 of the transfer electrode φ1 corresponding to the odd field is rendered into the highest one of three levels at time Tl which is in the vertical blanking period, and the signal charges of the odd fields are transferred as unnecessary charges to the vertical transfer portions 2, whereafter high-speed sweep-out operation of the vertical transfer portions 2 is performed for times T1-T2, whereby the unnecessary charges are discharged outwardly. In FIG. 6, areas in which two oblique lines intersect each other indicate the period of time during which a transfer pulse of a shorter period than the normal vertical transfer pulse is generated.
By such sweep-out of the unnecessary charges of the odd fields between time Tl to time T2 during the vertical blanking period, the signal charges of the light-receiving portions 1 of the odd fields are eliminated at the timing of time Tl, and accumulation of new signal charges is initiated from the timing of time Tl, and at time T4 which reaches the frame period, the signal charges are read out as video signals by the same operation as the conventional frame accumulation mode.
Accordingly, the accumulation time of the signal charges in the odd fields extends from time Tl to time T4, and time Tl to T2 is of the order of 1/2000 sec. and time T4-T2 is 1/60 sec. which is one field time and therefore, the accumulation time of the signal charges from time Tl till time T4 is (1/2000+1/60) sec. and thus about 1/60 sec., and this is substantially equivalent to the fact that driving has been effected in the field accumulation mode.
When the read-out of the video signal during each frame period of the even fields at time T6 is taken as an example, the electrode voltage V30 of the electrode φ3 used for the transfer of the signal charges of the even fields is rendered into the highest one of three levels at time T3 in the vertical blanking period which is about one field before time T6 when the video signals are read out, and the signal charges accumulated from time T2 are transferred as unnecessary charges to the vertical transfer portions, and by the use of time T3 to time T4, the unnecessary charges are discharged outwardly by the high-speed sweeping-out operation of the vertical transfer portions. Thus, the video signals read out in the even field initiated at the timing of time T6 are the signal charges obtained during the accumulation time from time T3 till time T6, and as in the case of the odd fields, the time T3-T4 is of the order of 1/2000 sec. and the time T4-T6 is 1/60 sec. and therefore, the accumulation time of the signal charges which is T3-T6 is about 1/60 sec., and this is substantially equivalent to the fact that driving has been effected in the field accumulation mode. The video signals swept out as the unnecessary charges from the vertical transfer portions by the high-speed sweeping-out operation during the times T1-T2, T3-T4, T5-T6, T7-T8, ... are in the vertical blanking period during which a vertical blanking signal V.BLK is in L state, and therefore will not appear on the picture plane even if they are not subjected to extraneous signal processing and thus, there is no problem of the image deterioration resulting from the high-speed sweep-out of the unnecessary charges.
Also, the video signals are read out in the driving by the field accumulation mode in which each of the odd fields and the even fields is about 1/60 sec. and therefore, no field afterimage will occur even if any moving object is photographed.
In FIG. 7, a driving signal generator 3 is responsive to a reference clock signal CLK generated by a crystal oscillator or the like to generate a frame synchronizing signal FLD, a transfer gate pulse TG, vertical transfer pulses V1', V2, V3', V4, a horizontal transfer pulse HI for driving the horizontal transfer portion of the solid state image pickup device, a horizontal blanking signal H.BLK and a vertical blanking signal V.BLK. A monostable multivibrator (hereinafter referred to as M.M) 4 is responsive to the falling of V.BLK to put out to an inverter 30 a signal Sl which assumes H level for a predetermined period of time. M.M 13 is responsive to the output of the inverter 30 to generate a signal S3, and M.M 14 is responsive to the signal S3 to generate a signal S4. D flip-flop 5 is responsive to the output of the inverter 30 and the output V1' of the generator 3 to put out a signal S2. A counter 7 counts the pulse V1', and D flip-flop 6 is responsive to the output of the D flip-flop 5 and the output of the counter 7 to generate a signal S5. An AND gate 8 puts out a pulse HI to JK flip-flop 9 during the period during which the signal S5 is at H level. The JK flip-flop 9 is responsive to M.BLK to frequency-divide a signal S9 and put out signals S10 and Sll. JK flip-flop 10 frequency-divides the signal Sll and generates signals S12 and S14, and JK flip-flop 11 frequency-divides the signal S10 and generates signals S13 and S15. An inverter 15, AND gates 17, 18, 19 and 20 and OR gates 21 and 22 make signals S6 and S7 for discharging signal charges from the light-receiving portions 1, in accordance with signals S4, TG and FLD. A bias circuit 31 increases a voltage applied to a buffer 28 during the period during which the signal S6 is at H level, whereby the buffer 28 renders the output of an AND gate 27 into the highest one of three levels. A bias circuit 32 is responsive to the signal S7 to operate for a buffer 29 like the bias circuit 31. An AND gate 12 receives the signals S2 and FLD and puts out a signal S8. The AND gate 27 receives the signal S12, the pulse A1' and the output of inverter 23, an AND gate 26 receives the signal S13, the pulse V2 and the output of inverter 23, an OR gate 25 receives the signal S14, the pulse V3' and the signal S8, and an OR gate 24 receives the signal S15, the pulse V4 and the signal S8.
The driving signal generator 3 is a conventional signal generator.
The periods during which the signals S3 and S4 and transfer gate pulse TG are at H level are set to a value shorter than the period of the normal vertical transfer pulse, e.g., pulse V1'.
The operations of the various circuits shown in FIG. 7 are illustrated in the time charts of FIGS. 8 and 9.
The signal Vl comprises a combination of the pulse V1' and the transfer gate pulse TG, and the signal V3 also comprises a combination of the pulse V3' and the transfer gate pulse TG.
Signals V10, V20, V30 and V40 are applied to the electrodes φ1, φ2, φ3, and φ4, respectively, of the solid state image pickup element shown in FIG. 1.
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An apparatus for making a video signal includes a solid state image pickup device having a plurality of first charge accumulation type photoelectric converting elements corresponding to the odd fields of the video signal, a plurality of second charge accumulation type photoelectric converting elements corresponding to the even field of the video signal, vertical transfer means, horizontal transfer means, first terminal means and second terminal means; output means for putting out a vertical blanking signal indicative of the vertical blanking period of the video signal, a first transfer pulse and a second transfer pulse; input means for alternately inputting the first and second transfer pulses to the first and second terminal means during each vertical blanking period and a generator for putting out a first driving pulse and a second driving pulse of a longer period than the first driving pulse to the vertical transfer means.
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FIELD OF THE INVENTION
[0001] The present invention relates to methods and compositions for preparing nucleoside analogues containing dioxolane sugar rings. In particular, the invention relates to the stereoselective synthesis 1,3-dioxolane nucleosides having β or cis configuration.
BACKGROUND OF THE INVENTION
[0002] Nucleosides and their analogues represent an important class of chemotherapeutic agents with antiviral, anticancer, immunomodulatory and antibiotic activities. Nucleoside analogues such as 3′-azido-3′-deoxythymidine (AZT), 2′,3′-dideoxyinosine (ddI), 2′,3′-dideoxycytidine (ddC), 3′-deoxy-2′,3′-didehydrothymidine (d 4 T) and (−)-2′-deoxy-3′-thiacytidine (3TC™) are clinically approved for the treatment of infections caused by the human immunodeficiency viruses. 2′-Deoxy-2′-methylidenecytidine (DMDC, Yamagami et al. Cancer Research 1991, 51, 2319) and 2′-deoxy-2′,2′-difluorocytidine (gemcytidine, Hertel et al. J. Org. Chem. 1988, 53, 2406) are nucleoside analogues with antitumor activity. A number of C-8 substituted guanosines such as 7-thia-8-oxoguanosine (Smee et al. J. Biol. Response Mod. 1990, 9, 24) 8-bromoguanosine and 8-mercaptoguanosine (Wicker et al. Cell Immunol. 1987, 106, 318) stimulate the immune system and induce the production of interferon. All of the above biologically active nucleosides are single enantiomers.
[0003] Recently, several members of the 3′-heterosubstituted class of 2′,3′-dideoxynucleoside analogues such as 3TC™ (Coates et al. Antimicrob. Agents Chemother. 1992, 36, 202), (−)-FTC (Chang et al. J. Bio. Chem. 1992, 267, 13938-13942) (−)-dioxolane C (Kim et al. Tetrahedron Lett. 1992, 33, 6899) have been reported to possess potent activity against HIV and HBV replication and possess the β-L absolute configuration. (−)-Dioxolane C has been reported to possess antitumor activity (Grove et al. Cancer Res. 1995, 55, 3008-3011). The dideoxynucleoside analogues (−)-dOTC and (−)-dOTFC (Mansour et al. J. Med. Chem. 1995, 38, 1-4) were selective in activity against HIV-1.
[0004] For a stereoselective synthesis of nucleoside analogues, it is essential that the nucleobase be introduced predominately with the desired relative stereochemistry without causing anomerization in the carbohydrate portion. One approach to achieve this is to modify the carbohydrate portion of a preassembled nucleoside by a variety of deoxygenation reactions (Chu et al. J. Org. Chem. 1989, 54, 2217-2225; Marcuccio et al. Nucleosides Nucleotides 1992, 11, 1695-1701; Starrett et al. Nucleosides Nucleotides 1990, 9, 885-897, Bhat et al. Nucleosides Nucleotides 1990, 9, 1061-1065). This approach however is limited to the synthesis of those analogues whose absolute configuration resembles that of the starting nucleoside and would not be practical if lengthy procedures are required to prepare the starting nucleoside prior to deoxygenation as would be the case for β-L dideoxynucleosides. An alternative approach to achieve stereoselectivity has been reported which requires assembling the nucleoside analogue by a reaction of a base or its synthetic precursor with the carbohydrate portion under Lewis acid coupling procedures or SN-2 like conditions.
[0005] It is well known in the art that glycosylation of bases to dideoxysugars proceed in low stereoselectivity in the absence of a 2′-substituent on the carbohydrate rings capable of neighboring group participation. Okabe et al. ( J. Org. Chem. 1988, 53, 4780-47861) reported the highest ratio of β:α isomers of ddC of 60:40 with ethylaluminium dichloride as the Lewis acid. However, with a phenylselenenyl substituent at the C-2 position of the carbohydrate (Chu et al. J. Org. Chem. 1980, 55, 1418-1420; Beach et al. J. Org. Chem. 1992, 57, 3887-3894) or a phenylsulfenyl moiety (Wilson et al. Tetrahedron Lett. 1990, 31, 1815-1818) the β:α ratio increases to 99:1. To overcome problems of introducing such substituents with the desired α-stereochemistry, Kawakami et al. ( Nucleosides Nucleotides 1992, 11, 1673-1682) reported that disubstitution at C-2 of the sugar ring as in 2,2-diphenylthio-2,3-dideoxyribose affords nucleosides in the ratio of β:α=80:20 when reacted with silylated bases in the presence of trimethylsilyltriflate (TMSOTf) as a catalyst. Although this strategy enabled the synthesis of the β-anomer, removal of the phenylthio group proved to be problematic.
[0006] Due to the limited generality in introducing the C-2 substituent stereoselectively, synthetic methodologies based on electrophilic addition of phenyl sulfenyl halides or N-iodosuccinimides and nucleobases to furanoid glycal intermediates have been reported (Kim et al. Tetrahedron Lett. 1992, 33, 5733-5376; Kawakami et al. Heterocycles 1993, 36, 665-669; ; Wang et al. Tetrahedron Lett. 1993, 34, 4881-4884; El-laghdach et al. Tetrahedron Lett. 1993, 34, 2821-2822). In this approach, the 2′-substituent is introduced in situ however, multistep procedures are needed for removal of such substituents.
[0007] SN-2 like coupling procedures of 1-chloro and 1-bromo 2,3-dideoxysugars have been investigated (Farina et al. Tetrahedron Lett. 1988, 29, 1239-1242; Kawakami et al. Heterocycles 1990, 31, 2041-2053). However, the highest ratio of β to α nucleosides reported is 70:30 respectively.
[0008] In situ complexation of metal salts such as SnCl 4 or Ti(O-Pr) 2 Cl 2 to the α-face of the sugar precursor when the sugar portion is an oxathiolanyl or dioxolanyl derivative produces β-pyrimidine nucleosides (Choi et al. J. Am. Chem. Soc. 1991, 113, 9377-9379). Despite the high ratio of β- to α-anomers obtained in this approach, a serious limitation with enantiomerically pure sugar precursor is reported leading to racemic nucleosides (Beach et al. J. Org. Chem. 1992, 57, 2217-2219; Humber et al. Tetrahedron Lett. 1992, 32, 4625-4628; Hoong et al. J. Org. Chem. 1992, 57, 5563-5565). In order to produce one enantiomeric form of racemic nucleosides, enzymatic and chemical resolution methods are needed. If successful, such methods would suffer from a practical disadvantage of wasting half of the prepared material.
[0009] As demonstrated in the above examples, the art lacks an efficient method to generate β-nucleosides. In particular, with sugar precursors carrying a protected hydroxymethyl group at C-4′, low selectivity is encountered during synthesis of β-isomers or racemization problems occur. Specifically, the art lacks a method of producing stereoselectively dioxolanes from sugar intermediates carrying a C-2 protected hydroxymethyl moiety without racemization. Therefore, a general stereoselective synthesis of biologically active β-nucleoside analogues is an important goal.
[0010] International patent application publication no. WO92/20669 discloses a method of producing dioxolanes stereoselectively by coupling sugar intermediates carrying C-2 ester moieties with silylated nucleobases and subsequently reducing the C-2 ester group to the desired hydroxymethyl group. However, over reduction problems in the pyrimidine base have been disclosed (Tse et al. Tetrahedron Lett. 1995, 36, 7807-7810).
[0011] Nucleoside analogues containing 1,3-dioxolanyl sugars as mimetics of 2′,3′-dideoxyfuranosyl rings have been prepared by glycosylating silylated purine and pyrimidine bases with 1,3-dioxolanes containing a C-2 hydroxymethyl and C-4 acetoxy substituents. The crucial coupling reaction is mediated by trimethylsilytriflate (TMSOT f ) or iodotrimethylsilane (TMSI) and produces a mixture of β and α-anomers in 1:1 ratio (Kim et al. J. Med. Chem. 1992, 35, 1987-1995 and J. Med. Chem. 1993, 36, 30-37; Belleau et al. Tetrahedron Lett. 1992, 33, 6948-6952; and Evans et al. Tetrahedron Asymmetry 1992, 4, 2319-2322). By using metal salts as catalysts the β-nucleoside is favoured (Choi et al. J. Am. Chem. Soc. 1991, 113, 9377-9379) but racemization or loss of selectivity become a serious limitation (Jin et al. Tetrahedron Asymmetry 1993, 4, 2111-2114).
SUMMARY OF THE INVENTION
[0012] According to an aspect of the present invention, there is provided a process for producing a β-nucleoside analogue compound of formula (III):
[0013] and salts thereof, wherein R 1 is a hydroxyl protecting group; and R 2 is a purine or pyrimidine base or an analogue thereof, the process comprising glycosylating said purine or pyrimidine base at a temperature below about −10° C., with an intermediate of formula (II):
[0014] wherein L is halogen.
[0015] Subsequent to glycosylation, the compound of formula (III) may then undergo deprotection of the hydroxyl protecting group R 1 to give a 1,3-dioxolane nucleoside analogue of formula (I)
[0016] wherein R 2 is as previously defined.
DETAILED DESCRIPTION OF THE INVENTION
[0017] The present invention provides a novel method for producing dioxolane nucleoside analogues by coupling sugar precursors carrying a C-2 protected hydroxymethyl group with purine or pyrimidine nucleobases in high yield and selectivity in favour of the desired β-isomers.
[0018] A <<nucleoside>> is defined as any compound which consists of a purine or pyrimidine base or analogue or derivative thereof, linked to a pentose sugar.
[0019] A <<nucleoside analogue or derivative>> as used hereinafter is a compound containing a 1,3-dioxolane linked to a purine or pyrimidine base or analog thereof which may be modified in any of the following or combinations of the following ways: base modifications, such as addition of a substituent (e.g. 5-fluorocytosine) or replacement of one group by an isosteric group (e.g. 7-deazaadenine); sugar modifications, such as substitution of hydroxyl groups by any substituent or alteration of the site of attachment of the sugar to the base (e.g. pyrimidine bases usually attached to the sugar at the N-1 site may be, for example, attached at the N-3 or C-6 site and purines usually attached at the N-9 site may be, for example, attached at N-7.
[0020] A purine or pyrimidine base means a purine or pyrimidine base found in naturally occurring nucleosides. An analogue thereof is a base which mimics such naturally occurring bases in that its structure (the kinds of atoms and their arrangement) is similar to the naturally occurring bases but may either possess additional or lack certain of the functional properties of the naturally occurring bases. Such analogues include those derived by replacement of a CH moiety by a nitrogen atom, (e.g. 5-azapyrimidines, such as 5-azacytosine) or conversely (e.g., 7-deazapurines, such as 7-deazaadenine or 7-deazaguanine) or both (e.g., 7-deaza, 8-azapurines). By derivatives of such bases or analogues are meant those bases wherein ring substituent are either incorporated, removed, or modified by conventional substituents known in the art, e.g. halogen, hydroxyl, amino, C 1-6 alkyl. Such purine or pyrimidine bases, analogs and derivatives are well known to those of skill in the art.
[0021] R 1 is a hydroxyl protecting group. Suitable protecting groups include those described in detail in Protective Groups in Organic Synthesis, Green, John, J. Wiley and Sons, New York (1981). Preferred hydroxyl protecting groups include ester forming groups such as C 1-6 acyl i.e. formyl, acetyl, substituted acetyl, propionyl, butanoyl, pivalamido, 2-chloroacetyl; aryl substituted C 1-6 acyl i.e. benzoyl, substituted benzoyl; C 1-6 alkoxycarbonyl i.e. methoxycarbonyl; aryloxycarbonyl i.e. phenoxycarbonyl. Other preferred hydroxyl protecting groups include ether forming groups such as C 1-6 alkyl i.e. methyl, t-butyl; aryl C 1-6 alkyl i.e. benzyl, diphenylmethyl any of which is optionally substituted i.e. with halogen. Particularly preferred hydroxyl protecting groups are t-butoxycarbonyl, benzoyl and benzyl each optionally substituted with halogen. In a more particularly preferred embodiment the R 1 hydroxyl protecting group is benzyl.
[0022] In a preferred embodiment, R 2 is selected from the group consisting of
[0023] wherein
[0024] R 3 is selected from the group consisting of hydrogen, C 1-6 alkyl and C 1-6 acyl groups;
[0025] R 4 and R 5 are independently selected from the group consisting of hydrogen, C 1-6 alkyl, bromine, chlorine, fluorine, and iodine;
[0026] R 6 is selected from the group of hydrogen, halogen, cyano, carboxy, C 1-6 alkyl, C 1-6 alkoxycarbonyl, C 1-6 acyl, C 1-6 acyloxy, carbamoyl, and thiocarbamoyl; and
[0027] X and Y are independently selected from the group of hydrogen, bromine, chlorine, fluorine, iodine, amino, and hydroxyl groups.
[0028] In a particularly preferred embodiment R 2 is
[0029] wherein R 3 and R 4 are as previously defined.
[0030] In a particularly preferred embodiment R 2 is cytosine or an analogue or derivative thereof. Most preferably R 2 is cytosine, N-acetylcytosine or N-acetyl-5-fluorocytosine.
[0031] In preferred embodiments R 3 is H. In another preferred embodiment R 3 is C 1-4 acyl such as acetyl.
[0032] In preferred embodiments R 4 and R 5 are independently selected from hydrogen, C 1-4 alkyl such as methyl or ethyl and halogen such as F, Cl, I or Br. In particularly preferred embodiments R 4 and R 5 are hydrogen. In another particularly preferred embodiment R 4 and R 5 are F.
[0033] In preferred embodiments R 6 is selected from hydrogen, halogen, carboxy and C 1-4 alkyl. In particularly preferred embodiments R 6 is H, F or Cl and most preferably H.
[0034] In preferred embodiments X and Y are independently selected from the group of H, F or Cl. In a particularly preferred embodiment X and Y are hydrogen.
[0035] L is selected from the group consisting of fluoro, bromo, chloro and iodo.
[0036] In a particularly preferred embodiment L is an iodo group. In this instance, leaving group (L) may be prepared by displacement of another leaving group (L′) i.e. acetoxy with Lewis acids containing an iodo moiety. Preferably such Lewis acids have the formula (IV):
[0037] wherein R 3 , R 4 and R 5 are independently selected from the group consisting of hydrogen; C 1-20 alkyl (e.g. methyl, ethyl, ethyl, t-butyl), optionally substituted by halogens (F, Cl, Br, I), C 6-20 alkoxy (e.g., methoxy) or C 6-20 aryloxy (e.g., phenoxy); C 7-20 aralkyl (e.g., benzyl), optionally substituted by halogen, C 1-20 alkyl or C 1-20 alkoxy (e.g., p-methoxybenzyl); C 6-20 aryl (e.g., phenyl), optionally substituted by halogens, C 1-20 alkyl or C 1-20 alkoxy; trialkylsilyl; fluoro; bromo; chloro and iodo; and R 6 is selected from the group consisting of halogen (F, Cl, Br, I) preferably I (iodo);
[0038] L′ is a leaving group capable of being displaced by an iodo leaving group using a Lewis acid of formula (IV). Suitable leaving groups L′ include acyloxy; alkoxy; alkoxycarbonyl; amido; azido; isocyanato; substituted or unsubstituted, saturated or unsaturated thiolates; substituted or unsubstituted, saturated or unsaturated seleno, seleninyl or selenonyl compounds; —OR wherein R is a substituted or unsubstituted, saturated or unsaturated alkyl group; a substituted or unsubstituted, aliphatic or aromatic acyl group; a substituted or unsubstituted, saturated or unsaturated alkoxy or aryloxy carbonyl group, substituted or unsubstituted sulphonyl imidazolide; substituted or unsubstituted, aliphatic or aromatic amino carbonyl group; substituted or unsubstituted alkyl imidiate group; substituted or unsubstituted, saturated or unsaturated phosphonate; and substituted or unsubstituted, aliphatic or aromatic sulphinyl or sulphonyl group. In a preferred embodiment L′ is acetoxy.
[0039] In a preferred embodiment, the present invention provides a stereoselective process for producing β-nucleoside analogues of formula (III), and salt or ester thereof, by glycosylation of the purine or pyrimidine base or analogue or derivative thereof, with an intermediate of formula (II) as defined previously under low temperature conditions. Preferably, the glycosylation reaction takes place at temperatures below −10° C. i.e. about −10 to −100° C. and more preferably below −20° C. In a most preferred embodiment the glycosylation reaction occurs between about −20 to −78° C.
[0040] The intermediate of formula II is reacted with a silylated purine or pyrimidine base, conveniently in a suitable organic solvent such as a hydrocarbon, for example, toluene, a halogenated hydrocarbon such as dichloromethane (DCM), a nitrile, such as acetonitrile, an amide such as dimethylformamide, an ester, such as ethyl acetate, an ether such as tetrahydrofuran, or a mixture thereof, at low temperatures, such as −40° C. to −78° C. Silylated purine or pyrimidine bases or analogues and derivatives thereof may be prepared as described in WO92/20669, the teaching of which is incorporated herein by reference. Such silylating agents are 1,1,1,3,3,3-hexamethyldisilazane, trimethylsilyl triflate, t-butyldimethylsilyl triflate or trimethylsilyl chloride, with acid or base catalyst, as appropriate. The preferred silylating agent is 1,1,1,3,3,3,-hexamethyldisilazane.
[0041] To form the compound of formula (I), appropriate deprotecting conditions include methanolic or ethanolic ammonia or a base such as potassium carbonate in an appropriate solvent such as methanol or tetrahydrofuran for N-4 deacetytion.
[0042] Transfer deacetylation hydrogenolysis with a hydrogen donor such as cyclohexene or ammonium formate in the presence of a catalyst such as palladium oxide over charcoal are appropriate for the removal of the 5′-aryl group.
[0043] It will be appreciated that the intermediate of formula (II) is constituted by intermediates IIa and IIb:
[0044] It will be further appreciated that, if the glycosylation step is carried out using equimolar amounts of intermediates IIa and IIb, a racemic mixture of β-nucleosides of formula I is obtained.
[0045] It will be apparent to those of skill in the art that separation of the resulting diastereomic mixture, for example after the coupling reaction between compounds of formula II and a silylated base, can be achieved by chromatography on silica gel or crystallization in an appropriate solvent (see, for example: J. Jacques et al. Enantiomers, Racemates and Resolutions, pp 251-369, John Wiley and Sons, New York 1981).
[0046] However, it is preferred that glycosylation is effected using an optically pure compound of either formula IIa or IIb, thereby producing the desired nucleoside analog in high optical purity.
[0047] The compounds of formula IIa or IIb exist as mixture of two diastereomers epimeric at the C-4 centre. We have now found that a single diastereomer, as well as any mixture of the diastereomers comprising the compounds of formula IIa, react with silylated bases to produce β-L nucleosides in high optical purity. The base at C-4 having the cis-stereochemistry relative to the hydroxymethyl moiety at C-2. The rate of the reaction of the two diastereomers of formula IIa with silylated bases may however, be different. Similar findings exist for the intermediates of formula IIb for the synthesis of β-D nucleosides.
[0048] In a preferred embodiment, the present invention provides a step for producing anomeric iodides of formula II by reacting known anomeric 2S-benzyloxymethyl-1,3-dioxolane-4S and -4R acetoxy derivatives of formula (V) with iodotrimethylsilane or diiodosilane at low temperatures (−78° C.) prior to glycosylation with silylated pyrimidine or purine base or analogue or derivative thereof (Scheme 1).
[0049] Reagents and conditions:
[0050] Toluene TSHO/80%/2.7:1.0 cistrans;
[0051] ii) MeOH/LiOH;
[0052] iii) Column separation;
[0053] iv) Pb(OAc) 4 /MeCN/Py/2h/RT/80%; and
[0054] v) TMSI or SiH 2 I 2 /CH 2 Cl 2 /−78° C.
[0055] Suitable methods for producing the anomeric acetoxy intermediate (VI) will be readily apparent to those skilled in the art and include oxidative degradation of benzyloxymethylacetals derived from L-ascorbic acid (Belleau et al. Tetrahedron Lett. 1992, 33, 6949-6952) or D-mannitol (Evans et al. Tetrahedron Asymmetry 1993, 4, 2319-2322).
[0056] We have also found that the known 2S-benzyloxymethyl-1,3-dioxolane-4S-carboxyclic acid (V) can be generated in preference to its 2S,4R isomer by reacting commercially available 2,2-dimethyl-1,3-dioxolane-4S-carboxylic acid with a protected derivative of hydroxyacetaldehyde, such as benzyloxyacetaldehyde, under acidic conditions
[0057] In the diastereoselective process of this invention, there is also provided the following intermediates:
[0058] 2S-Benzyloxymethyl-4R-iodo-1,3 dioxolane and 2S-Benzyloxymethyl-4S-iodo-1,3 dioxolane;
[0059] β-L-5′-Benzyl-2′-deoxy-3′-oxa-N-4-acetyl-cytidine;
[0060] β-L-5′-Benzyloxy-2′-deoxy-3′-oxacytidine;
[0061] β-L-5′-Benzyl-2′-deoxy-3′-oxa-5-fluoro-N4-acetyl-cytidine; and
[0062] β-L-5′-Benzyl-2′-deoxy-3′-oxa-5-fluorocytidine.
EXAMPLE 1a
2S-Benzyloxymethyl-4R-iodo-1,3 dioxolane and 2S-Benzyloxymethyl-4S-iodo-1,3 dioxolane (compound #1)
[0063] [0063]
[0064] A mixture consisting of 2S-benzyloxymethyl-4S acetoxy-1,3 dioxolane and 2S-benzyloxymethyl-4R-acetoxy-1,3 dioxolane in 1:2 ratio (6 g; 23.8 mmol) was dried by azeotropic distillation with toluene in vacuo. After removal of toluene, the residual oil was dissolved in dry dichloromethane (60 ml) and iodotrimethylsilane (3.55 ml; 1.05 eq) was added at −78° C., under vigorous stirring. The dry-ice/acetone bath was removed after addition and the mixture was allowed to warm up to room temperature (15 min.). The 1 H NMR indicated the formation of 2S-benzyloxymethyl-4R-iodo-1,3-dioxolane and 2S-benzyloxymethyl-4S-iodo-1,3 dioxolane.
[0065] [0065] 1 H NMR (300 MHz, CDCl 3 ) δ 3.65-4.25 (2H,m); 4.50-4.75 (4H,m) 5.40-5.55 (1H, overlapping triplets); 6.60-6.85 (1H, d of d); 7.20-7.32 (5H,m).
EXAMPLE 1b
2S-Benzyloxymethyl-4R-iodo-1,3 dioxolane and 2S-Benzyloxymethyl-4S-iodo-1,3 dioxolane (compound #1)
[0066] [0066]
[0067] A mixture consisting of 2S-benzyloxymethyl-4S acetoxy-1,3 dioxolane and 2S-benzyloxymethyl-4R-acetoxy-1,3 dioxolane in 1:2 ratio (6 g; 23.8 mmol) was dried by azeotropic distillation with toluene in vacuo. After removal of toluene, the residual oil was dissolved in dry dichloromethane (60 ml) and diiodosilane (2.4 ml; 1.05 eq) was added at −78° C., under vigorous stirring The dry-ice/acetone bath was removed after addition and the mixture was allowed to warm up to room temperature (15 min.). The 1 H NMR indicated the formation of 2S-benzyloxymethyl-4R-iodo-1,3-dioxolane and 2S-benzyloxymethyl-4S-iodo-1,3 dioxolane.
[0068] [0068] 1 H NMR (300 MHz, CDCl 3 ) δ 3.65-4.25 (2H,m); 4.50-4.75 (4H,m) 5.40-5.55 (1H, overlapping triplets); 6.60-6.85 (1H, d of d); 7.20-7.32 (5H,m).
EXAMPLE 2
β-L-5′-Benzyl-2′-deoxy-3′-oxa-N-4-acetyl-cytidine (compound #2)
[0069] [0069]
[0070] The previously prepared iodo intermediate (example 1) in dichloromethane, was cooled down to −78° C. Persylilated N-acetyl cytosine (1.1 eq) formed by reflux in 1,1,1,3,3,3-hexamethyl disilazane (HMDS) and ammonium sulphate followed by evaporation of HMDS was dissolved in 30 ml of dichloromethane and was added to the iodo intermediate. The reaction mixture was maintained at −78° C. for 1.5 hours then poured onto aqueous sodium bicarbonate and extracted with dichloromethane (2×25 ml). The organic phase was dried over sodium sulphate, the solid was removed by filtration and the solvent was evaporated in vacuo to produce 8.1 g of a crude mixture. Based on 1 H NMR analysis, the β-L-5′-benzyl-2′-deoxy-3′-oxacytidine and its α-L isomer were formed in a ratio of 5:1 respectively. This crude mixture was separated by chromatography on silica-gel (5% MeOH in EtOAc) to generate the pure β-L (cis) isomer (4.48 g). Alternatively, recrystallization of the mixture from ethanol produces 4.92 g of pure β isomer and 3.18 g of a mixture of β and α-isomers in a ratio of 1:1.
[0071] [0071] 1 H NMR (300 MHz, CDCl 3 ) δ 2.20 (3H,S,Ac); 3.87 (2H,m,H-5′), 4.25 (2H,m,H-2′); 4.65 (2H,dd,OCH 2 Ph); 5.18 (1H,t,H-4′); 6.23 (1H,m,H-1′); 7.12 (1H,d,H-5); 7.30-7.50 (5H,m,Ph); 8.45 (2H,m,NH+H-6).
EXAMPLE 3
β-L-5′-Benzyloxy-2′-deoxy-3′-oxacytidine (compound #3)
[0072] [0072]
[0073] The protected β-L isomer (4.4 g) of example 2 was suspended in saturated methanolic ammonia (250 ml) and stirred at room temperature for 18 hours in a closed-vessel. The solvents were then removed in vacuo to afford the deacetylated nucleoside in pure form.
[0074] [0074] 1 H NMR (300 MHz, CDCl 3 ) δ 3.85 (2H,m,H-5′); 4.20 (2H,m,H-2′); 4.65 (2H,dd,OCH 2 Ph); 5.18 (1H,t,H-4′); 5.43 (1H,d,H-5); 5.50-5.90 (2H,br.S,NH 2 ); 6.28 (1H,m,H-1′); 7.35-7.45 (5H,m,Ph); 7.95 (1H,d,H-6).
EXAMPLE 4
β-L-2′-deoxy-3′-oxacytidine (compound #4)
[0075] [0075]
[0076] β-L-5′-Benzyl-2′-deoxy-3′-oxacytidine from the previous example, was dissolved in EtOH (200 ml) followed by addition of cyclohexene (6 ml) and palladium oxide (0.8 g). The reaction mixture was refluxed for 7 hours then it was cooled and filtered to remove solids. The solvents were removed from the filtrate by vacuum distillation. The crude product was purified by flash chromatography on silica-gel (5% MeOH in EtOAc) to yield a white solid (2.33 g; 86% overall yield, α D 22 =−46.70° (c=0.285; MeOH) m.p.=192 - 194° C.
[0077] [0077] 1 H NMR (300 MHz,DMSO- d 6 ) δ 3.63 (2H,dd,H-5′); 4.06 (2H,m,H-2′); 4.92 (1H,t,H-4′); 5.14 (1H,t,OH); 5.70 (1H,d,H-5); 6.16 (2H,dd,H-1′); 7.11 - 7.20 (2H,brS,NH 2 ); 7.80 (1H,d,H-6) 13 C NMR (75 MHz,DMSO-d 6 ) δ 59.5 (C-2′); 70.72 (C-5′); 81.34 (C-4′); 93.49 (C-1′); 104.49 (C-5); 140.35 (C-4); 156.12 (C-6); 165.43 (C-2).
EXAMPLE 5
β-L-5′-Benzyl-2′-deoxy-3′-oxa-5-fluoro-N4-acetyl-cytidine (compound #5)
[0078] [0078]
[0079] The previously prepared iodo derivatives (example 1) in dichloromethane, was cooled down to −78° C. Persylilated N-acetyl-5-fluorocytosine (1.05 eq) formed by reflux in 1,1,1,3,3,3-hexamethyldisilazane (HMDS) and ammonium sulphate followed by evaporation of HMDS was dissolved in 20 ml of dichloromethane (DCM) and was added to the iodo intermediate. The reaction mixture was maintained at −78° C. for 1.5 hours then poured onto aqueous sodium bicarbonate and extracted with dichloromethane (2×25 ml). The organic phase was dried over sodium sulphate, the solid was removed by filtration and the solvent was evaporated in vacuo to produce 8.1 g of a crude mixture. Based on 1 H NMR analysis, the β-L-5′-benzyl-2′-deoxy-3′-oxa-5-fluoro-N4-acetyl-cytidine and its α-L isomer were formed in a ratio of 5:1 respectively. This crude mixture was separated by chromatography on silica-gel (5% MeOH in EtOAc) to generate the pure β-L (cis) isomer (4.48 g). Alternatively, recrystallization of the mixture from ethanol produces 4.92 g of pure β isomer and 3.18 g of a mixture of β and α-isomers in a ratio of 1:1.
[0080] [0080] 1 H NMR (300 MHz, CDCl 3 ) δ 2.20 (3H,S,Ac); 3.87 (2H,m,H-5′), 4.25 (2H,m,H-2′); 4.65 (2H,dd,OCH 2 Ph); 5.18 (1H,t,H-4′); 6.23 (1H,m,H-1′); 7.12 (1H,d,H-5); 7.30-7.50 (5H,m,Ph); 8.45 (2H,m,NH+H-6).
EXAMPLE 6
β-L-5′-Benzyl-2′-deoxy-3′-oxa-5-fluorocytidine (compound #6)
[0081] [0081]
[0082] The crude mixture from previous step (example 5) was suspended in methanolic ammonia (100 ml) and stirred for 18 hours at room temperature in a closed reaction vessel. The solvents were removed in vacuo to afford the deacetylated mixture which was separated by flash chromatography on silica gel (2% to 3% MeOH in EtOAc) to yield 1.21 g pure β isomer (yield 45% with respect to this isomer).
EXAMPLE 7
β-L-2′-deoxy-3′-oxa-5-fluorocytidine (compound #7)
[0083] [0083]
[0084] The deacetylated pure β-L isomer (900 mg; 2.8 mmol) prepared as described in example 6 was dissolved in EtOH (40 ml) followed by addition of cyclohexene (3 ml) and palladium oxide catalyst (180 mg). The reaction was refluxed for 24 hours and the catalyst was removed by filtration. The solvents were removed from the filtrate by vacuum distillation. The crude product was purified by flash chromatography on silica-gel (5% to 7% MeOH in EtOAc) to yield a white solid (530 mg ; 82% yield). (α 22 D )=−44.18° (c=0.98; MeOH).
[0085] [0085] 1 H NMR (300 MHz, DMSO-d 6 ); δ 3.62-3.71 (2H,m,H-5′); 4.03-4.13 (2H;m,H-2′); 4.91 (1H,t,H-4′); 5.32 (1H,t,OH); 6.11 (1H;t;H-1′); 7.53-7.79 (2H,b,NH 2 ); 8.16 (1H;d,H-6); 13 C NMR (75 MHz, DMSO-d 6 ); δ 59.34 (C-2′); 70.68 (C-5′); 80.78 (C-4′); 104.53-(C-1′); 124.90, 125.22 (C-4); 134.33, 136.73 (C-5); 153.04 (C-2); 156.96, 157.09 (C-6).
EXAMPLE 8
Isomeric Purity Determination of β-L-2′-deoxy-3′-oxacytidine Nucleoside Analogues
[0086] The determination of the isomeric purity (β-L versus α-L and β-L versus β-D isomers) was determined on a Waters HPLC system consisting of a 600 controller pump for solvent delivery, 486 uv detector, 412 WISP auto sampler and a 740 Waters integrator module. An analytical chiral reverse phase cyclobond I RSP column (Astec, 4.6×250 mm i.d.) was used and packed by the manufacturer with β-cyclodextrin derivatized with R′S-hydroxypropyl ether. The mobile phase consisted of acetonitrile (A) and water containing 0.05% triethylamine (B) with the pH adjusted to 7.05 by glacial acetic acid. The column was operated under isocratic conditions at 0° C. using a mixture of 5% A and 95% B. Such conditions are modifications of those reported in DiMarco et al. ( J. Chromatography, 1993, 645, 107-114). The flow rate was 0.22 ml/min and the pressure was maintained at 648 - 660 psi. Detection of nucleosides was monitored by uv absorption at 215 and 265 nm. Samples of β-D isomer and racemic compounds were prepared as reported (Belleau et al. Tetrahedron Lett 1992, 33, 6948-6952) and used for internal references and co-injection. Under these conditions the isomeric purity of compound #4 produced according to example 4 was >99% and that of compound #7 according to example 7, was >96%.
[0087] The isomeric purity of dioxolane nucleosides having been prepared according to the general scheme 2, under varying conditions i.e. temperature and Lewis acid is represented in table 1 below. Those prepared at temperatures above −10° C. exhibited reduced stereoselectivity.
TABLE 1 Base Lewis acid Temperature (° C.) Cis:trans 5F-N(Ac)-cytosine TMSI a:−78 b:−78 8:1 5F-N(Ac)-cytosine SiH 2 I 2 a:−78 b:−78 7:2 N(Ac)-cytosine TMSI a:−78 b:−78 5:1
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The present invention relates to methods and compositions for preparing biologically important nucleoside analogues containing 1,3-dioxolane sugar rings. In particular, this invention relates to the stereoselective synthesis of the beta (cis) isomer by glycosylating the base with an intermediate of formula (II) below a temperature of about −10° C.
wherein R 1 and L are as defined herein.
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This application is a continuation-in-part of co-pending application Ser. No. 09/621,226, filed on Jul. 21, 2000. Priority to this application is hereby claimed under 35 U.S.C. § 120, and the co-pending application is hereby incorporated by reference in its entirety.
FIELD OF THE INVENTION
The present invention relates generally to an apparatus and a method for molding multi-fiber optical connector ferrules.
BACKGROUND OF THE INVENTION
A fiber optic cable may include one or more optical fibers capable of transmitting audio, video or other information. Examples of optical fibers are disclosed in U.S. Pat. Nos. 5,561,730 and 5,457,762. Fiber optic cables are laid over long distances and require optical connectors or ferrules to link discrete segments of the optical fibers. As used herein, the term “ferrule” refers to a plug assembly or a structure that receives a terminal end of an optical fiber or optical fiber ribbon and then abuts against an opposing ferrule to align corresponding optical fiber or ribbon for transmission of an optical signal or signals.
An example of an optical ferrule is disclosed in U.S. Pat. No. 5,214,730 to Nagasawa et al. FIG. 1 illustrates an optical ferrule similar to that depicted in Nagasawa, and shows multi-fiber ferrules 3 and 3 ′ connected to optical fiber ribbons 1 and 1 ′, respectively. Ribbon 1 comprises multiple optical fibers 2 to be aligned with corresponding optical fibers 2 ′ (not shown) from ribbon 1 ′. Ferrule 3 defines a plurality of optical fiber bores adapted to receive fibers 2 and two guide pin bores 4 adapted to receive guide pins 6 . Guide pins 6 align ferrule 3 with ferrule 3 ′, when the two ferrules are connected to each other to align optical fibers 2 and 2 ′ to optimize optical transmission.
During a typical molding process to produce ferrules 3 , bore forming pins are inserted through the mold cavity to create the guide pin bores and the optical fiber bores in the ferrules. Molten plastic is then injected into the mold cavity, and after the plastic solidifies sufficiently the pins are withdrawn to form the bores in the ferrules to receive the optical fibers and guide pins. Prior to connecting to ferrule 3 , optical ribbon 1 is stripped of its outer matrix coating and its buffer layer to expose fibers 2 . The individual fibers 2 are inserted into the fiber bores on ferrule 3 . Various well-known techniques are used to permanently affix fibers 2 to ferrule 3 . End faces 5 and 5 ′ of ferrules 3 and 3 ′ are then polished along with the exposed ends of fibers 2 . A pair of guide pins 6 is then inserted into guide holes 4 to connect and align the ferrules. A spring clip (not shown) may be used to clamp the two ferrules together.
There is a premium placed on the precise alignment of opposing optical fibers at a connection to minimize signal losses, which diminishes the quality of the optical transmission through the connection. The precision of aligning opposing optical fibers is more sensitive with multi-fiber ferrules due to the presence of multiple optical fibers and to each fiber's location relative to each other and relative to the guide pins within the ferrules. Additionally, when an optical fiber is a single-mode fiber, i.e., the optical signal is transmitted through only a small portion of the fiber, the alignment needs to be even more precise.
A conventional ferrule molding method uses a series of V-shaped open grooves machined into a block of the mold cavity to retain the bore forming pins inserted into the mold cavity. FIG. 2 shows a cross-sectional view of this conventional molding method, where fiber bore forming pins 7 and guide pin bore forming pins 8 are shown disposed in V-shaped grooves 9 . The disadvantages of this or similar open groove constructions include a tendency of the pins 7 and 8 to float within the V-shaped grooves in the direction of arrow A during the molding process. This float contributes to imprecise alignment of the bores formed in the molded ferrule. Additionally, after repeated uses of a mold cavity with this groove construction, flash begins to build up in areas indicated by B. This flash build up requires frequent cleaning of the grooves. Also, as can be seen, pins 7 contact the V-shaped grooves only along two lines of contact and thus all the friction forces of the repeated insertion and removal of the pins are imparted along these two lines of contact, thereby causing uneven wear along the sides of the V-shaped groove. This causes the alignment of the pins to become progressively more imprecise.
The drawbacks of the molding process with the V-shaped grooves have been addressed by the “small hole technology” disclosed by U.S. Pat. No. 5,786,002 to Dean et al. As shown in FIG. 3, Dean et al. discloses a guide block assembly comprising a plurality of fiber bore blocks 12 , at least two guide pin bore blocks 14 and a plurality of spacer blocks 16 arranged in any desirable configuration in a mold cavity. Each fiber bore block 12 defines a small hole or bore 18 adapted to receive during the molding process a pin having the diameter of an optical fiber, and each guide pin bore blocks 14 defines a bore 19 adapted to receive a pin having a diameter of a guide pin. Molten plastic is injected into the mold cavity and the pins are thereafter withdrawn from the holes and the mold cavity to form receptacles in the ferrules to receive optical fibers 2 or guide pins 6 . The use of bores more precisely retains the pins during the molding process than the use of V-shaped open grooves. Dean et al. resolves the known drawbacks from the V-shaped open groove molding technique, and provides the additional benefits of establishing precise spatial relationship among the modular blocks, by machining the surfaces of the adjoining blocks.
Dean et al., however, requires the fabrication of multiple blocks, which increases the costs and may become less economical when used to fabricate ferrules for a small number of optical fibers. Hence, there remains a need in the art for a molding apparatus that has the advantages realized in the Dean et al. '002 patent, but requires fewer components and is more economical to produce.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a device for molding multi-fiber ferrules using small hole technology.
Another object of the invention is to minimize the costs of fabricating a device for molding multi-fiber ferrules.
Yet, another object of the invention is to provide a device capable of precisely aligning and retaining the bore forming pins during the molding of multi-fiber ferrules.
These and other objects of the present invention are accomplished by a guide block assembly for aligning and retaining at least one fiber bore forming pin and at least one guide pin bore forming pin during the molding of a ferrule. The guide block assembly comprises a unitary member defining at least one fiber bore and at least one guide pin bore. The fiber bore is created by an electric discharge machining (EDM) wire. One starter hole is created for each bore with the EDM wire attached at one end to an EDM machine. The starter hole is then enlarged by a second EDM wire connected to an EDM machine at both ends.
The ratio between the length of the fiber bore to its diameter is preferably from approximately 3::1 to 10::1, more preferably from approximately 4::1 to 8::1, and most preferably approximately 6::1. In accordance with another aspect of the invention, the unitary guide block assembly has a front face, wherein the front face is altered to form a non-rectilinear surface. The non-rectilinear surface can be a curve surface, a stepped surface, an angled surface, or a pedestal surface, among others.
In accordance with other aspects of the invention, an open cavity behind the fiber bore is provided to reduce the flash build-up, and longitudinal slots are formed around the fiber bore to reduce the wear and tear on the bore forming pins.
In accordance with another aspect of the invention, a method for fabricating a guide block assembly defining at least one fiber bore for aligning and retaining at least one fiber bore forming pin during a molding of a ferrule is provided. This method comprises the steps of securing a blank to a wire electric discharge machining (EDM) machine, forming a starter hole in said blank with a wire attached at one end to the EDM machine, and enlarging said starter hole to a predetermined size and dimension of the fiber bore. The enlarging step may comprise the steps of threading a second wire through the starter hole, and connecting both ends of the second wire to an EDM machine (which may be a different EDM machine) to enlarge the starter hole. This method may also comprise the step of forming a non-rectilinear surface on a front surface of the guide block assembly before or after the fiber bore is formed.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is illustrated by way of example in the accompanying drawings, in which:
FIG. 1 is a perspective view of a pair of conventional multi-fiber optical connector ferrules;
FIG. 2 is a cross-sectional view of a conventional V-shaped open groove guide block assembly;
FIG. 3 is front view of another prior art guide block assembly;
FIG. 4 is a perspective view of a representative arrangement of a mold cavity environment illustrating a preferred embodiment of a guide block assembly of the present invention;
FIG. 5 is an exploded view showing the top and bottom portions of the guide block assembly of the present invention;
FIG. 6 is an enlarged front view showing an array of fiber bores and guide pin bores of the guide block assembly of the present invention;
FIG. 7 is a cross-sectional view of the bottom portion of the guide box assembly along line 7 — 7 shown in FIG. 5;
FIG. 8 is a top view of the bottom portion of the guide block assembly showing another aspect of the invention;
FIG. 9 is a longitudinal cross-sectional view of a fiber bore with a fiber bore forming pin inserted therein;
FIG. 10 is a front view of an alternative embodiment of the present invention;
FIG. 11 is a front view of another alternative embodiment of the present invention;
FIG. 12 is a perspective front view of another embodiment of the present invention;
FIG. 13 is a perspective back view of the embodiment show n in FIG. 12;
FIG. 14 is a top view of the embodiment shown in FIGS. 12 and 13;
FIG. 15A is a front view of the embodiment shown in FIGS. 12, 13 and 14 , and
FIG. 15B is an enlarged view of a portion of FIG. 15A;
FIG. 16A is a front view of the alternative embodiment of the present invention, and
FIG. 16B is an enlarged view of a portion of FIG. 16A;
FIGS. 17A-E illustrate variations of the end face of the ferrule produced by embodiments of the guide block assembly of the present invention; and
FIGS. 18A-B are enlarged views of a portion of the guide block assembly showing the milled front face.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the drawings, wherein reference numbers are used to designate like parts, FIG. 4 shows one preferred embodiment of the guide block assembly 20 , disposed in a mold cavity 22 to illustrate the environment for the guide block assembly 20 . Assembly 20 has a mold face 24 , which can serve as one of the walls 26 defining mold cavity 22 .
Referring to FIG. 5, assembly 20 comprises a top portion 28 and a bottom portion 30 . Top portion 28 defines on its lower surface a number of semi-circular guide pin bore grooves 32 a and a number of semi-circular fiber bore grooves 34 a . As illustrated by FIG. 5, fiber bore grooves 34 a are positioned on the inside of the guide pin bore grooves 32 a . Grooves 32 a and 34 a are sized and configured to match with semi-circular guide pin bore grooves 32 b and semicircular fiber grooves 34 b located on the top surface of bottom portion 30 , such that when the top and bottom portions are assembled together, the semi-circular fiber bore grooves 34 a and 34 b are joined to form fiber bores 34 and semi-circular guide pin bore grooves 32 a and 32 b are joined to form guide pin bores 32 . The top portion 28 also defines two vertical channels 36 a corresponding to vertical channels 36 b defined on the bottom portion 30 , such that conventional fasteners such as nuts and bolts may clamp the top portion 28 to the bottom portion 30 .
Additionally, the top and bottom portions 28 and 30 may have a pair of corresponding key pin grooves 35 a and 35 b , respectively, as illustrated in FIG. 5 . Key pin grooves 35 a and 35 b together form key pin bore 35 adapted to receive a key pin when the top and bottom portions 28 and 30 are assembled. The key pin 37 is inserted into bore 35 to align the top portion to the bottom portion. The bottom portion may also have receiving channels 40 disposed on its bottom surface. Receiving channels 40 are sized and dimensioned to receive corresponding bosses on the mold cavity (not shown), such that the guide block assembly 20 can be securely affixed onto the mold cavity. Also, top and bottom portions 28 and 30 may also have through holes 42 and 44 , whose function is described below.
FIG. 6 is an enlarged exemplary view of the assembly 20 showing the relative dimension and location of guide pin bore grooves 32 a and 32 b in relation to fiber grooves 34 a and 34 b . Although, only two sets of guide pin bore grooves and fiber grooves are shown, any number of grooves can be defined by assembly 20 . FIG. 7 shows a cross-sectional view of bottom portion 30 illustrating by example the location of the guide pin bore grooves 32 b , channels 36 b and key pin groove 35 b in relation to each other.
In accordance with another aspect of the invention illustrated in FIG. 8, the length of the fiber bores 34 is kept relatively short relative to its diameter, and an open cavity or space 39 is provided behind the bores 34 , such that the molding residue can be pushed through the bores on repeated molding cycles and collect in the open cavity or space 39 instead of clogging the fiber bores. While the open cavity or space 39 is illustrated on bottom portion 30 , it may also be on the top portion 28 or both. The preferred ratio between the length and diameter of the fiber bore is approximately between 3::1 and 10::1; the more preferred ratio is approximately between 4::1 to 8::1; and the most preferred ratio is approximately 6::1.
Guide block assembly 20 is configured to retain a plurality of fiber bore forming pins 50 receivable in fiber bores 34 and retain guide pin bore forming pins 51 receivable in guide pin bores 32 , as shown in FIG. 4 . Any suitable jig, not shown, can be used to hold and to move pins 50 and 51 into and out of bores 34 and 32 , respectively. During the molding of a multi-fiber ferrule, the pins are inserted into the bores and the molding material is injected into the mold cavity formed in part by walls 24 and 26 around the pins. For example, as shown in FIG. 9, the distal end portion 52 of a representative fiber bore forming pin 50 is partially inserted into fiber bore 34 and molding material is injected into mold cavity 22 and covers mold zone 54 of fiber bore forming pin 50 outside of bore 34 . After the mold material sets, the pins are retracted to leave behind a plurality of molded bores in the ferrules. Fiber bore forming pins 50 will create a number of fiber bores sized and dimensioned to receive optical fibers in close tolerance. Since the location of the bores 32 and 34 can be precisely machined as described below, and the pins 50 and 51 are held in these precisely positioned bores during the molding process, the molded bores in the ferrules created by the withdrawal of the pins are also precisely positioned to receive the optical fibers and guide pins, especially at the front face 24 of assembly 20 . It should be noted that the front face of the ferrule would be formed at the front face 24 .
Fiber bore forming pins 50 may be the actual fibers when the ferrules are molded directly around the fibers. As shown in FIGS. 6-8, the guide pin bores 32 and guide pin bore forming pins 51 typically create larger diameter molded guide pin bores than the molded fiber bores to receive the guide pins to align two opposing multi-fiber ferrules. The shape of the guide bore forming pins 51 and guide pin bores 32 is shown to be circular. This shape, however, can be any shape, such as oval, triangular or polygonal.
The present invention is directed to an apparatus and method to precisely arrange the fiber bore forming pins and the guide pin bore forming pins relative to each other in such a way that the precision is repeatable over a large number of molding cycles. As discussed in the background of the invention, the method of arranging the bores with V-shaped grooves as shown in FIG. 2 suffers from floating of pins, flash build up, and premature and uneven wear of the guide block assembly. By using pre-arranged bores in the guide block assembly and insertable pins, float and uneven wear are reduced and flash build up is substantially eliminated. Specifically, bores 32 and 34 provide less room than the V-shaped open grooves for the floating of the pins 50 and 51 during the molding process. Furthermore, by providing bores the contact between the pins and the bores is spread out over the circumferential contact surface between the bores and the pins, thereby decreasing wear on the bores. Additionally, by adopting the preferred range of ratios between the length and diameter of the fiber bore 34 and by providing an open cavity 39 behind the fiber bores 34 as shown in FIG. 8, the clogging problem is substantially reduced.
Also by having only a limited number of components, e.g., two portions 28 and 30 in the above-described preferred embodiment, the present invention reduces the costs of fabricating the guide block assembly over the guide block assembly discussed in Dean et al., which comprises a relatively high number of blocks.
In another aspect of the present invention, the bottom surface of the top portion 28 of the guide block assembly 20 and the top surface of the bottom portion 30 are mirror images of each other. When the two portions are clamped or bolted face-to-face together, any remaining misalignment after the key pin 37 in inserted into the key pin bore 35 can be readily detected. Such misalignment would make the diameter of the bores in the guide block assembly smaller in the direction from the mold face 24 toward the back of the assembly, when the grooves 34 a and 34 b are aligned at the mold face but misaligned elsewhere. A simple lapping process performed on the bore can readily remove any such misalignment. The lapping process comprises covering a precision gauge wire having a diameter smaller than the bore with a lapping compound, e.g., an abrasive compound such as one-quarter micron diamond grit, and then using the precision gauge wire with the lapping compound into the bore to remove any misalignments.
The guide block assembly 20 of the present invention can be manufactured by machining the semi-circular grooves into a metal or ceramic block using known precision grinding techniques. Preferably, the top and bottom portions 28 and 30 can be manufactured by an electric discharge machining (EDM) process. A precision wire EDM machine, or more preferably a submersible wire EDM machine, removes metals from metal blocks by creating thousands of electrical discharges per second that flow between a wire and the metal blocks, vaporizing metal in the controlled area. In the preferred submersible wire EDM machine, a zinc-coated brass, molybdenum or tungsten wire of approximately 0.0005 to 0.003 inch in diameter is submerged in a tank of dielectric fluid, such as deionized water, along with the metal blocks. As the wire is moved relative to the metal blocks, semi-circular grooves are formed on the blocks. Typically, eight to twelve passes from the EDM wire can create the preferred fiber pin groove. The motion of the wire may be controlled by any commercially available computer numerical control (CNC) software. A detailed discussion the EDM processes is provided in the Machinery's Handbook, by E. Oberg et al, (Industrial Press, 1996)(25 th edition) at page 1266. This discussion is hereby incorporated by reference.
At least one manufacturing advantage is realized by the fact that opposing surfaces on the top/bottom portions of the assembly 20 are mirror-images of each other. Hence, regardless of the actual manufacturing technique used, e.g., grinding, machining, or EDM processes, the two corresponding opposing surfaces can be manufactured at the same time using the same equipment. For example, the bottom surface of top portion 28 and the top surface of the bottom portion 30 illustrated in FIGS. 5 and 6 can be manufactured at the same time by securing two metal blanks side by side, and corresponding pairs of semi-circular grooves 34 a and 34 b or 32 a and 32 b are created by the EDM wire or by the blade of a cutting tool across the two metal blanks. This ensures that any one pair of grooves is properly cut and positioned on the metal blanks. As discussed above and illustrated in FIGS. 5, 7 , and 8 , the through holes 42 and 44 provided on the metal blanks are dimensioned and configured to receive fasteners, such as screws or bolts and nuts, to secure the metal blanks together. The holes 42 , 44 may have countersinks (not shown) for the fasteners that hold the top and bottom portions 28 , 30 together during the EDM or machining process.
By utilizing only a small number of components to construct the guide block assembly while still employing the “small hole technology,” the present invention is able to avoid the drawbacks of the conventional V-shaped open groove method, and accomplishes the same objectives as Dean et al. at lower costs.
It will also be noted that although only two semi-circular fiber grooves 34 a,b on the top and bottom portions are illustrated in FIG. 5, any number of fiber grooves can be machined on the top and bottom portions. Furthermore, although only one row of fiber bores is shown on guide block assembly 20 , the present invention may have any number of rows, as shown in FIG. 11 . The guide block assembly 70 may have a plurality of rows of fiber bores, for example two rows of fiber bores. Assembly 70 comprises three portions: a top portion 72 , a middle portion 74 and a bottom portion 76 . In this example, top portion 72 defines five semi-circular fiber grooves on its lower surface to correspond with the five semi-circular fiber grooves on the top surface of the middle portion 74 . Middle portion 74 in turn has three semi-circular fiber grooves and two semicircular guide pin bore grooves defined on its lower surface to correspond with the three semicircular fiber grooves and two semi-circular guide pin bore grooves defined on the top surface of the bottom portion 76 . Hence when the three portions of assembly 70 are assembled, a first row of five fiber bores and a second row of three fiber bores disposed between two guide pin bores are formed, as shown. In accordance with the present invention, any number of rows of any number of bores can be formed and the guide pin bores can be located on any row using the manufacturing processes described above. For example, the bottom surface of top portion 72 and top surface of middle portion 74 can be fabricated at the same time, and the bottom surface of middle portion 74 and top surface of bottom portion 76 can be fabricated at the same time.
Alternatively, the guide block assembly can be fabricated from a single block as shown in FIG. 10 to further reduce the costs of fabricating the guide block assembly. Using the wire EDM process, after a starter bore 62 is first created by conventional techniques such as drilling, the EDM wire may be inserted in the starter hole and the cut a path 64 to form fiber bores 34 . Path 64 may then be filled with a high temperature epoxy. Guide pin bores 32 may be drilled as shown, or path 64 may extend from fiber bores 34 to create guide pin bores 32 .
In accordance with another aspect of the invention, another unitary guide block assembly 80 is shown in FIGS. 12-15. Guide block assembly 80 is made from a single block of material. Unlike the guide block assembly 60 discussed above, guide block assembly 80 does not require the EDM wire to form path 64 to connect the fiber bores and/or guide pin bores together, and therefore obviates the needs to back fill path 64 with epoxy. As shown, unitary guide block assembly 80 has relief cavity 39 disposed behind fiber bores 34 , as described above. Similar to guide block assembly 20 , assembly 80 also has guide pin bores 32 disposed to the outside of fiber bores 34 , and receiving channels 40 sized and dimensioned to received corresponding bosses on the mold cavity (not shown), such that the guide block assembly can be securely affixed onto the mold cavity, as discussed above and as illustrated in FIG. 4 . Assembly 80 also has front face 24 , which serves as one of the walls of mold cavity 22 .
The advantages of unitary guide block assemblies 80 and 60 over guide block assembly 20 include the elimination of a number of components, such as key pin bore 35 and key pin 37 to align the two halves of the guide block assembly, through holes 42 and 44 to clamp the halves together during the manufacturing process, and the vertical channels 36 a and 36 b to clamp the halves together during the ferrule molding process. Additionally, the lapping process to ensure proper alignment of the fiber bore grooves is also not necessary.
Guide block assembly 80 is preferably manufactured by a novel EDM manufacturing process. First, the relief cavity 39 is cut by conventional method in the blank block. An additional relief channel 82 may be provided behind relief cavity 39 . Next, a series of starter holes is fashioned into the blank. One starter hole is prepared for each guide pin bore 34 and for each fiber bore 32 . Due to the relative sizes of these bores, the starter holes for the guide pin bores can be larger than the starter holes for the fiber bores. The starter holes are formed by a single EDM wire, which is connected to the EDM machine only at one end. The free end of the EDM wire is positioned at the desired location and electrical discharges are emitted therefrom to create the starter holes. Advantageously, the starter holes for the fiber bores 34 are located opposite from relief cavity 39 , where the width of the blank is thinnest, which, in addition to preventing flash build-up, also facilitates the creation of the starter holes. After the starter holes are made, a longer continuous feed EDM wire is threaded through each starter hole. This longer wire is then connected to the EDM machine at both end and the electrical discharges from this longer wire are emitted to enlarge the starter hole until the hole reaches the desired size of the fiber bore 32 . Advantageously, the blank block remains clamped to the EDM machine during the entire manufacturing process, thereby eliminating possible location and sizing errors due to handling and repositioning of the blank. The starter holes for the guide pin bores 34 may also be created the same way. Due to the relative larger size of the guide pin bores, their starter hole may also be created by conventional methods, such as drilling.
The starter-hole EDM wire typically is 0.0020-0.0025 inch in diameter and 3 mm (0.12 inch) in length. As described above, EDM wires are typically made from zinc coated brass, molybdenum, or tungsten. Due to the relative shortness of the wire, it can be formed rigid and straight, which increase the accuracy of the position and orientation of the starter holes. As a result, the fiber holes 32 made in accordance with this EDM wire method extend in a precise straight line and running perpendicular to the front surface 24 of the unitary guide block assembly 80 .
Several advantages directly flow from this EDM wire method. First, due to the ability to pin point the starter hole and then create straight fiber bores, the radial offset between corresponding optical fibers from two adjoining ferrules made in accordance with this method has been reduced to ¼ μm for single mode fibers and ½ μm for multi mode fibers. As discussed above, single mode fiber use only a relatively small portion of the fiber's cross-section for signal transmission, while multi-mode fibers use more of the fiber's cross-section. For example, a single mode fiber uses approximately 9 μm section of a 125 μm optical fiber, while a multi-mode fiber uses approximately 50-60 μm of the 125 μm optical fiber. Hence, tight control of the radial offset between connecting optical fibers, particularly a single mode fiber, is desirable and can be achieved by the ferrules made in accordance with the present invention. Furthermore, the radial offset between the fiber bores 32 and the fiber bore forming pins 50 during the molding operation has also been reduced to about ½ μm.
Another advantage realized from the EDM wire method is that due to the more precise perpendicular orientation of the fiber bores 32 relative to the front surface 24 of guide block assembly 80 , front surface 24 may have an arcuate surface or other non-rectilinear surfaces milled or otherwise formed thereon, after the fiber bores have been formed while maintaining the precise location of the fiber bores on the milled front surface 24 . In other words, if the fiber bores 32 are not precisely oriented perpendicular to front surface 24 when front surface 24 is milled, the location of the fiber bores 32 on the milled surface will shift relative to the location of the fiber bores 32 on the pre-milled surface. This shifting produces inaccurate guide block assemblies, which in turn produces inaccurate placement of the fibers at the front face of the ferrules. The fiber bores 32 may also be formed after the front surface 24 is milled.
It is known in the art that providing a protruding curve or other non-rectilinear surfaces on the end face 5 of ferrule 3 positions the terminal ends of the optical fibers 2 forward of the ferrule to reduce back reflectance and improve signal transmission between ferrules. Examples of milled front surface 24 are illustrated in FIGS. 18A and 18B. Heretofore, each ferrule is typically ground or polished after molding to achieve the curve surface. A unitary milled guide block assembly in accordance with the present invention obviates the need to grind each ferrule separately, thereby reducing manufacturing costs. In addition to a milled curved front face 24 , which produces the curved end face 5 in ferrule 3 shown in FIG. 17A, front face 24 may have other shapes milled thereon to produce other shapes for end face 5 . For example, front face 24 may have a step milled therein, shown in FIG. 18A, to produce the stepped face 5 shown in FIG. 17 B. Front face 24 may also have individual holes milled around each fiber bore 32 to produce the end face 5 shown in FIG. 17 C. Front face 24 may also have an elongated channel milled around all the fiber bores 32 , shown in FIG. 18B, to produce the pedestal end face 5 shown in FIG. 17D, and front face 24 may have a slant formed thereon to produce the angled end face 5 shown in FIG. 17 E.
Additionally, while FIGS. 12-15 show the unitary guide block assembly 80 with two fiber bores 32 defined thereon, it may have any number of fiber bores. For example, unitary guide block assembly 84 shown in FIGS. 16A-16B has 12 fiber bores and the ferrules shown in FIGS. 17A-E were made with a guide block assembly defining 4 fiber bores. Hence, this present invention is not limited to any specific number of fiber bores.
In accordance with another aspect of the present invention, a plurality of longitudinal slots may be cut along the periphery of the fiber bores 32 or the guide pin bores 34 to reduce the wear and tear on the fiber bore forming pins 50 and the guide pin bore forming pins 51 . While it remains desirable to evenly distribute the contact between the pins and the bores during the molding process as discussed above, it is also advantageous to reduce the contact areas between these two components. Preferably, four longitudinal slots disposed along the bores reduce such contact areas.
While various descriptions of the present invention are described above, it is understood that the various features of the present invention can be used singly or in combination thereof. Therefore, this invention is not to be limited to the specifically preferred embodiments depicted therein.
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A guide block assembly for aligning and retaining fiber bore forming pins and guide pin bore fanning pins in precise relation to each other during the molding of a multi-fiber ferrule includes a unitary member defining at least one fiber bore and at least one guide pin bore. Each fiber bore, and optionally each guide pin bore, is formed by creating a starter hole using a first electric discharge machining (EDM) wire and enlarging the starter hale using a second EDM wire. Each fiber bore has a length to diameter ratio of between approximately 3::1 to 10::1, more preferably between approximately 4::1 to 8::1, and most preferably approximately 6::1. The guide block assembly may further include a cavity behind the fiber bore and a front face that forms a non-rectilinear surface on the face of the female. The unitary block assembly contains fewer parts and is less expensive to manufacture.
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This application is a continuation of application Ser. No. 318,155 filed Nov. 4, 1981, now abandoned.
BACKGROUND AND SUMMARY OF THE INVENTION
The present invention relates generally to pressure responsive compressor valve assemblies and more particularly to such assemblies employing disc type valve members and particularly adapted for use on refrigeration compressors.
The present invention comprises a discharge valve assembly having an improved combination valve guide and spring retainer member which cooperates with and guides movement of an improved discharge valve. The discharge valve of the present invention is an improvement on the discharge valve disclosed in assignee's copending application Ser. No. 971,309, filed Dec. 20, 1978, now abandoned in favor of continuation application Ser. No. 219,849, filed Dec. 23, 1980 now U.S. Pat. No. 4,368,755. The combination valve guide and spring retainer is an improvement over that disclosed in assignee's copending application Ser. Nos. 234,343, now abandoned in favor of application Ser. No. 318,053, filed Nov. 4, 1981 and 234,169, both filed Feb. 13, 1981 and preferably incorporates the multi-leaf spring biasing means disclosed therein and represents an alternative to the spring guide and stop disclosed in assignee's copending application Ser. No. 114,345, filed Jan. 22, 1980. The valve guide and spring retainer may also incorporate the diffuser arrangement disclosed in assignee's copending application Ser. No. 318,055 entitled "Discharge Valve Assembly For Refrigeration Compressors" filed of even data herewith and along with the improved discharge valve disclosed herein is well suited for use with either the valve plate assembly disclosed in assignee's copending application Ser. No. 114,346, filed Jan. 22, 1980 or preferably the valve plate assembly disclosed in assignee's copending application Ser. No. 318,052 entitled "Valve Plate Assembly For Refrigeration Compressors" filed of even data herewith.
Valve plates and cylinder head assemblies can become relatively complex in configuration for certain valve arrangements and as a result may be quite costly to manufacture and sometimes to assemble.
The present invention provides an improved valve assembly which includes a modified discharge valve design and a modified valve guide spring support member. The discharge valve includes an arcuate or spherical shaped portion provided around the lower peripheral edge thereof which appears to provide significant improvement in the gas flow characteristics whereby a given flow volume may be discharged from the compression chamber with less opening movement or lift of the discharge valve. Not only does this design appear to provide improved flow characteristics and thus better performance efficiencies, but the reduced lift required operates to reduce the compressor valve assembly operating noise significantly. Additionally, the valve assembly of the present invention includes a valve guide and spring retainer having a continuous annular valve guide surface portion extending around the outer periphery of the discharge valve and operative to provide a continuous guiding surface for engagement by the discharge valve to maintain the valve in proper aligned position during cyclical opening and closing movement thereof. The continuous surface not only insures proper alignment is maintained but also avoids the possibility of discrete wear points occurring along the peripheral surface of the discharge valve and appears to contribute to the reduction in operating noise emanating from the valve assemblies. This improved valve guide also is more economical to manufacture, requiring less machining of surfaces than the multiple finger arrangement of prior designs.
Additional advantages and features of the present invention will become apparent from the subsequent description and the appended claims taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary section view of a portion of a refrigeration compressor showing a valve assembly in accordance with the present invention installed in operative relationship to a cylinder of the compressor;
FIG. 2 is a plan view of the valve assembly of FIG. 1, the view being taken along line 2--2 thereof;
FIG. 3 is an enlarged fragmentary section view of the valve assembly of FIG. 1 showing the discharge valve in an open position and the associated valve guide;
FIG. 4 is an enlarged fragmentary edge view of the discharge valve of the present invention shown in overlying relationship to the edge contour of a discharge valve of a prior design; and
FIG. 5 is a graphical illustration of flow area as a function of position along each of the two discharge valves shown in FIG. 4.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, there is shown a compressor housing 10 having a compression chamber defined by cylinder 12 including a reciprocating piston 14 disposed therein with a valve assembly 16 in accordance with the present invention and head 18 secured in overlying relationship thereto. Compressor housing 10 includes both suction and discharge gas passages 20 and 22 for conducting fluid to and from the cylinder 12.
Valve assembly 16 includes a three piece valve plate assembly of the type disclosed in assignee's copending application Ser. No. 318,052, entitled "Valve Plate Assembly For Refrigeration Compressors" filed of even date herewith including upper, center, and lower valve plates 24, 26, and 28 respectively secured together by an oven brazing process and cooperating to define a suction gas chamber 30, a suction gas inlet passage 32, a discharge gas passage 34 and discharge valve seat 36. A ring type suction valve 38 (shown in an open position in FIG. 1) seats against the lower surface of the lower valve plate 28. The valve assembly also includes a discharge valve guide and spring retainer 40 and discharge valve 42 both in accordance with the present invention and leaf spring biasing means 44 of the type disclosed in assignee's copending application Ser. No. 234,343, positioned therebetween.
Discharge valve guide and spring retainer 40 includes a generally cylindrical upper portion 46 having a center bore 48 extending therethrough and an annular flange portion 50 extending radially outwardly from a lower end thereof. A second annular flange portion 52 projects axially downwardly (as shown) from the periphery of radial flange portion 50 so as to define a cylindrical cavity 54 into which discharge valve 42 is movable with inner sidewalls 56 thereof being selectively engageable with discharge valve 42 to guide such movement. Preferably, flange portion 52 will extend axially downwardly into discharge passage 34 a distance sufficient to slightly overlap the peripheral sidewall of discharge valve 42 when it is in a closed position as shown in FIG. 1. Multiple leaf spring 44 is positioned within the cavity 54 with peripheral portions thereof bearing against the inner surface 58 of the radial flange 50 and the center portion thereof bearing against the upper planar surface 60 of discharge valve 42 so as to bias it into a closed position. The lower peripheral outer edge portion 62 of axial flange 52 is also beveled slightly to improve the flow of discharge gas through the discharge gas passage 34.
An elongated generally rectangular shaped bridge member 64 is provided to support guide member 40 within the discharge gas passage 34 and includes a bore 66 into which cylindrical portion 46 is preferably press fitted or otherwise suitably secured. An enlarged diameter recessed portion 68 is also provided in the lower surface of bridge member 64 to partially receive radial flange portion 50 of guide member 40. Suitable bolts 70 are provided to secure bridge member 64 and the associated guide member 40 to the valve plate assembly 16 in substantially the same manner as described in assignee's aforementioned related application. It should be noted, however, that while as shown and described herein, bridge member 64 and valve guide and spring retainer 40 are separately fabricated they may alternatively be manufactured as a single one piece construction.
As best seen with reference to FIG. 3, discharge valve 42 has a generally cylindrical sidewall 72 extending from substantially planar upper surface 60 to a beveled edge portion 74 extending around the periphery thereof. Preferably this beveled edge portion will be disposed at an included angle of approximately 43° relative to a plane lying parallel to surface 60 thereof and is designed to sealingly seat against valve seat 36 which is positioned at an included angle of approximately 45° relative to the aforementioned plane. An arcuate or curved surface portion 76 extends from the lower edge 78 of the beveled portion 72 to the lower planar surface 80 of discharge valve 42. Preferably, arcuate portion 76 will define a surface of revolution of an arc and in some cases may define the surface area of a zone of a sphere having a center positioned along the axis of the discharge valve 42. It may in some cases be preferable to position or select arcuate portion 76 such that it is approximately tangent to the beveled surface 74 at the point of intersection 78 therewith so as to avoid possible disruption of gas flow thereacross. The height or axial dimension of arcuate portion 76 must be such as to position the lower planar surface 80 of discharge valve 42 in substantially coplanar relationship with the lower surface of the lower valve plate when discharge valve 42 is in a fully closed position. Preferably, discharge valve 42 will be fabricated from a suitable polymeric composition material such as Vespel as employed in the fabrication of the valves disclosed in the aforementioned application Ser. No. 219,849, although it may be necessary to increase the axial thickness thereof or to utilize a metal therefor due to the higher stresses encountered as a result of the increased surface area thereof which continuously is exposed to the cylinder 12.
The distinctions and advantages afforded by the design of discharge valve 42 may be best seen and explained with reference to FIGS. 4 and 5. FIG. 4 shows an enlarged edge profile view of the discharge valve of the present invention (shown in full lines) overlayed on an edge profile of a discharge valve of the type disclosed in the aforementioned application Ser. No. 219,849 (shown partially in phantom for clarity) and FIG. 5 is a graphical representation of the flow area provided between the outer surfaces of the respective discharge valves and the valve seat portion 36 of valve plate assembly 16 at various points therealong indicated in FIG. 4.
As shown in FIG. 5, the prior discharge valve having a continuous conical sidewall provided no discharge flow area between points A and A' thereof because this area represented a portion of the lower planar surface of the discharge valve. The area between A and B' of the prior discharge valve provides a substantially linearly increasing flow area due to the increasing diameter of the concentric conical surfaces defining the flowpath. However, with the discharge valve of the present invention, the area between A' and B' is of an arcuate contour representing the surface of revolution of an arc and thus provides a significantly greater flow area over the entire range from A' to B' and which gradually decreases as the flow progress outwardly from B'. Because both the discharge valve of the present invention and that of the prior design have identical conical contours between B' and B, the flow area provided between these points is identical. Thus, as is dramatically and clearly illustrated in the graphical representation, the provision of an arcuate or spherical surface portion along the lower edge of the discharge valve operates to significantly increase the resulting flow area through which discharge gas may exit from the cylinder although the re-expansion volume of the cylinder is also increased slightly due to the space provided by the arcuate surface portion. Viewed another way, assuming a given volume of discharge gas must be passed through the area between the discharge valve and valve seat, the discharge valve must open or have a sufficient lift to provide the required flow area. Because the discharge valve of the present invention affords a significantly greater flow area for a given lift, the actual lift or opening movement of the valve may be substantially reduced and yet still allow the given volume of gas to be discharged. This reduced lift contributes to quieter valve operation and hence compressor operation.
While the subject discharge valve offers substantial advantages for some applications, it may not be ideally suited for all such applications. For example, the increase in re-expansion or clearance volume resulting from the arcuate surface portion may be significant in some applications such as low temperature compressors. Also, the arcuate surface portion renders the present discharge valve slightly more expensive to manufacture than the prior design and reduces the seating area of the valve. Thus while the subject discharge valve provides significant advantages, they are not obtained without compromise.
While it will be apparent that the preferred embodiment of the invention disclosed is well calculated to provide the advantages and features above stated, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope or fair meaning of the subjoined claims.
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A discharge valve assembly is disclosed which includes an improved valve guide and spring retainer having a continuous annular surface surrounding the discharge valve and operative to guide movement thereof. An improved discharge valve is also disclosed which includes an arcuate lower peripheral surface portion defined by a surface of revolution of a curve which surface may form the surface of a zone of a sphere. The annular guide surface and improved discharge valve cooperate to the noise level emanating from the compressor valve assembly and to facilitate manufacture and assembly of the components thereof.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. patent application Ser. No. 14/221,317, filed on Mar. 21, 2014, the entire disclosure of which is hereby incorporated herein by reference in their entirety.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] N/A
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The present invention generally relates window treatment components and more specifically to a light blocking side valance or trim piece for use in conjunction with any type of window treatment.
[0005] 2. Description of Related Art
[0006] Window treatments such as a slat blinds, venetian blinds, mini blinds, roller blinds, blackout shades, roman shades and the like are useful for providing privacy and blocking incoming light from a window. However, the complex mounting hardware and actuators needed for the window treatment to operate effectively typically requires the shade portion of the treatment to be somewhat narrower than the actual window opening in which the treatment is installed. For example, in the case of a typical roller shade, mounting brackets must be secured at the top of the window opening and protrude out into the opening at least ½″ on each side. Thus, in order for the roller blind to fit into the bracket and function properly, the shade is offset from either side of the window opening, leaving at least a ½″ edge gap through which unwanted light can pass through. The same problem is true for venetian blinds, roman shades, and other window treatments where the mounting hardware is placed inside the window opening (typically at the top edge of the opening). The gap at either side may be even more significant if the window treatment includes complex or large actuators such as turning rods, cords, and the like that require space accommodations. The resultant edge gap not only allows unwanted light to leak through but it also can result in a window treatment that appears unfinished or otherwise unsightly. Accordingly, there is a need in the art to provide a means to block unwanted light from leaking through at the sides of the window treatment while also maintaining a cohesive and attractive look.
[0007] Some attempts have been made to fill the space or gap at the edge of the windows left by window treatments; however, none are versatile enough to be used with any type of window treatment and installation configuration.
[0008] For example, U.S. Patent Application Publication No. 2013/0048230 to Marocco describes a window opening space filler used to adjust the window opening width to accommodate standard sized blinds in otherwise larger window openings. The filler includes a bracket piece affixed to the window opening and a filler member that attaches to the bracket piece and extends into the window opening so the user can reduce the width of the window opening at the side or edge thereof. The device is designed so the blind rides behind the filler member. The disadvantage of this arrangement is that the filler device requires two pieces and is completely visible because the blind rides behind the member. Further, only certain types of blinds such as roller blinds can be accommodated by the filler member without snagging because the blind rides behind the extended filler member. Multi-slat blinds will not function properly with this configuration because they do not have sufficient space behind the blind to rotate. Further still, because the blind rides behind the filler member, the blind will have a tendency to sway back toward the window which can again cause an edge gap that allows light to pass through.
[0009] U.S. Patent Application Publication No. 2012/0012261 to Santoro et al. describes a window shade assembly having a two-part side channel system including a side channel attachment piece and a trim piece that is received in a slot on the attachment piece. The shade is received in a cavity created by the two pieces and slides up and down therein. The device is designed to retain the blind so that it doesn't sway from front to back inside the window and is not necessarily designed to block light at the side edges. More importantly, because the blind must ride inside the small cavity between the attachment piece and the trim piece, the side channel can only accommodate roller blinds as slat or venetian blinds will not have sufficient space to rotate and open.
[0010] Accordingly, there is a significant need in the art for a light blocking solution that can be used with any type of blind in an aesthetically pleasing manner. It is, therefore, to the effective resolution of the aforementioned problems and shortcomings of the prior art that the present invention is directed. However, in view of the window treatment components in existence at the time of the present invention, it was not obvious to those persons of ordinary skill in the pertinent art as to how the identified needs could be fulfilled in an advantageous manner.
SUMMARY OF THE INVENTION
[0011] The present invention is a light-blocking device for a window treatment to fill gaps on either side of the window treatment and to retain the window treatment at a distance spaced away from the window. The device is configured as a side valance or trim piece comprising an L-shaped member having a mounting face and a retaining face, the retaining face extending substantially perpendicular from the mounting face. The side valance may be constructed as an extrusion of any length desired. At least one frangible width adjustment notch is disposed lengthwise along the retaining face for adjusting the width of the device by breaking it along the desired notch. The mounting face is attached to a side of a window opening such that the retaining face extends outwardly from the side of the window opening to block light and retain the window treatment. When installed in a window opening, the retaining face is configured to be disposed between the window treatment and the window to keep the treatment away from the wall while also closing the gaps between the window opening and the edges of the window treatment. The length and width adjustability allows the side valance to be used for virtually any window treatment installation and configuration.
[0012] In some embodiments, the side valance includes at least one frangible length adjustment notch disposed transversely across the valance similar to the width adjustment 20 notches but allowing the user to adjust the length of the piece to fit a wide variety of window openings. In some embodiments, a strip of protective material is disposed on an interior aspect of the side valance where the mounting face and the retaining face meet, in order to protect the window treatment as it moves up and down along the device.
[0013] Accordingly, it is an object of the present invention to provide a device that fills the gap commonly found between the sides of a window opening and a window treatment to prevent unwanted light from passing through the gap.
[0014] It is another object of the present invention to provide a device that retains a window treatment and spaces it away from the window for optimal stability, functionality, and aesthetics.
[0015] It is another object of the present invention to provide a gap filling, light-blocking, and retaining device for window treatments that can be used for any style of window treatment including roller blinds, roman shades, slat blinds, and the like without the need to reconfigure or rearrange the components of the window treatment.
[0016] It is another object of the present invention to provide a gap-filling, light-blocking device for window treatments that is adjustable in both length and width to accommodate the parameters of virtually any window treatment installation.
[0017] It is another object of the present invention to provide a gap-fill, light-blocking device for window treatments that can be retrofitted into existing window treatment installations easily and quickly.
[0018] With the foregoing and other objects in view, there is provided, a method of preventing light from passing through a gap between a window frame and a window treatment disposed in the window frame, the window frame having a window opening and vertical sides, the method including the steps of providing an L-shaped light-blocking device with a mounting face, a retaining face extending substantially perpendicular to the mounting face, and at least one frangible width adjustment notch disposed lengthwise along the retaining face, and attaching the mounting face to one of the vertical sides of the window frame to have the retaining face extend from the vertical side between the window treatment and the window opening and block at least some light passing between the window frame and the window treatment.
[0019] With the objects in view, there is also provided a method of preventing light from passing through a gap between a window frame and a window treatment disposed in the window frame, the window frame having a window opening and vertical sides, the method including the steps of providing a pair of L-shaped light-blocking devices each with a mounting face, a retaining face extending substantially perpendicular to the mounting face, and at least one frangible width adjustment notch disposed lengthwise along the retaining face, and attaching the mounting face of each of the light-blocking devices to one of the vertical sides of the window frame to have the retaining face respectively extend from the vertical side between the window treatment and the window opening and block at least some light passing between the window frame and the window treatment.
[0020] In accordance with another mode, the light-blocking device has a longitudinal extent, a transverse extent, and at least one frangible length adjustment notch disposed across at least a portion of the transverse extent.
[0021] In accordance with a further mode, each of the light-blocking devices has a longitudinal extent, a transverse extent and at least one frangible length adjustment notch disposed across at least a portion of the transverse extent.
[0022] In accordance with an added mode, the mounting face and the retaining face meet at a corner having an interior aspect and further comprising a strip of protective material disposed on the interior aspect of the corner.
[0023] In accordance with an additional mode, the retaining face is wider than the mounting face.
[0024] In accordance with yet another mode, the at least one frangible adjustment notch is substantially U-shaped and at least partially penetrates the retaining face.
[0025] In accordance with yet a further mode, the at least one frangible length adjustment notch is disposed across at least one of the transverse extent of the mounting face, the transverse extent of the retaining face, and the transverse extent of both the mounting face and the retaining face.
[0026] In accordance with yet an added mode, the at least one frangible adjustment notch is formed to break along the notch when a breaking force is applied at the retaining face.
[0027] In accordance with yet an additional mode, the attaching step is performed by attaching the mounting face to one of the vertical sides of the window frame to have the retaining face extend from the vertical side between the window treatment and the window opening and block at least some light passing between the window frame and the window treatment and retain the window treatment at the window frame.
[0028] In accordance with again another mode, there is provided the step of breaking the light-blocking device along the at least one frangible width adjustment notch to reduce a width of the retaining face.
[0029] In accordance with again a further mode, there is provided the step of breaking the light-blocking device along the at least one frangible length adjustment notch to adjust a length of the device to fit the vertical side of the window frame.
[0030] In accordance with again an added mode, two of the light-blocking devices are provided and the mounting face of each of the light-blocking devices is attached to one of the vertical sides of the window frame to have the retaining face respectively extend from the vertical side between the window treatment and the window opening and block at least some light passing between the window frame and the window treatment.
[0031] In accordance with a concomitant mode, there is provided at least one of the steps of breaking the light-blocking device along the at least one frangible width adjustment notch to reduce a width of the retaining face and breaking the light-blocking device along the at least one frangible length adjustment notch to adjust a length of the device to fit the vertical side of the window frame.
[0032] In accordance with these and other objects that will become apparent hereinafter, the instant invention will now be described with particular reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] FIG. 1 is a front perspective view of one embodiment of the side valance of the present invention having width adjustment features;
[0034] FIG. 2 is a front perspective view of another embodiment of the side valance of the present invention having a length and width adjustment features;
[0035] FIG. 3 is an end view of the side valance of the present invention showing the width adjustment feature;
[0036] FIG. 3A is a close-up view of the width adjustment features shown in FIG. 3 ;
[0037] FIG. 4 is another perspective view of the side valance of the present invention; and
[0038] FIG. 5 shows the side valance in use with an exemplary window treatment.
DETAILED DESCRIPTION
[0039] FIG. 1 is a front perspective view of one embodiment of the side valance 10 of the present invention. Side valance 10 is designed as a trim piece device to block light between the edge of a window treatment and a window opening and retain the window treatment away from the window. Side valance 10 is generally configured as an L-shaped member of any desired length and width comprising a mounting face 11 and a retaining face 12 wherein the retaining face 12 is perpendicular to the mounting face 11 . In some embodiments, the mounting face 11 and retaining 12 are generally planar rectangular bodies and the two faces 11 and 12 meet at corner 13 such that the retaining face extends from corner 13 , terminating at outer edge 121 . An interior aspect of corner 13 may be filled with a protective material 14 such as a felt, rubber, or other soft substance to prevent damage to the window treatment as further described here.
[0040] In some embodiments, the retaining face 12 is somewhat wider than the mounting face 11 . Optionally provided lengthwise along the retaining face 12 are one or more frangible width adjustment notches 15 . Width adjustment notches 15 are disposed at predetermined locations on the retaining face 12 and allow for adjustment of the width of the retaining face 12 . Adjustment is accomplished by applying force to the retaining face 12 such that it breaks or snaps off at the desired width adjustment notch 15 . This obviates the need to use a saw or power tool to cut the side valance 10 down to fit the particular parameters of an installation. FIG. 2 is a perspective view of another embodiment of the side valance 10 . Here, the valance 10 further includes one or more length adjustment notches 16 disposed transversely across the side valance toward one end. These length adjustment notches 16 allow for adjustment of the length of the side valance by applying force to the end of the side valance 10 and breaking or snapping it at the desired notch 16 . The depicted embodiments shown two width adjustment notches 15 and two length adjustment notches 16 ; however, any desired number of notches can be provided spaced apart at any desired increment.
[0041] FIG. 3 is an end view of the side valance 10 again shown the mounting face 11 and retaining face 12 . Here, corner 13 is shown as having a relatively rounded shape with the interior aspect including protective material 14 . The profile of width adjustment notches 15 can be seen in FIG. 3 and more easily in close-up FIG. 3A as substantially U-shaped grooves running lengthwise along the side valance 10 . In a preferred embodiment, the width adjustment notches 15 partially penetrate the surface of the retaining face 12 so that the valance 10 is easily frangible at the notches to provide a clean break and resultant edge. The length adjustment notches 16 shown in FIG. 2 may be similarly configured. It is appreciated that the notches 15 and 16 could be disposed on either side of the side valance 10 . Also seen in the end view is protective material 14 disposed on the interior aspect of the corner 13 where the two faces 11 and 12 meet. The protective material preferably runs along the entire length of the side valance 10 .
[0042] FIG. 4 shows one embodiment of the side valance 10 in full view. From here it can be seen that side valance 10 comprises an extruded member of any desired length or dimension. The side valance 10 can be constructed of any suitable opaque light-blocking material such as metal, plastic, wood, or combinations thereof and it may be pre-painted a desired color or may be of such a material that is suitably paintable. The dimensions of the side valance are not limiting, however by way of example, a standard side valance 10 may be 60 inches long and have a ½″ wide mounting face 11 and a 2″ wide retaining face 12 . In this example, the width adjustment notches 15 may be located such that the retaining face 12 can be adjusted to a width of ½″ and 1 ″ depending on which width adjustment notch 15 is used as a break point. In this configuration the notches are ½″ apart with the outermost notch ½″ from the outer edge 121 of the retaining face 12 . The length adjustment notches 16 can be at any desired increment such as 12″ to allow the 60 inch side valance to be adjusted to 48″, 36″, 24″ and so on. In another example, the length of the side valance 10 may be 72 inches and adjustable by length adjustment notches 16 to 60″, 48″, and 36″.
[0043] FIG. 5 depicts one application of the side valance of the present invention in use with a window treatment to block light from passing through at the sides of the window treatment. Here it can be seen that two side valances 10 are employed and attached to either side of a window opening 20 that has a blind 30 disposed therein. The mounting face 11 of the side valances 10 is attached to the side walls 21 and 22 of the window opening 20 , respectively by known means such as a screw, nail, rivet, adhesive, double-sided tape, or the like. The side valances 10 are oriented such that once attached to the window opening, the retaining face 12 extends slightly into the window opening creating a light blocking and retaining trim feature for the blind 30 . In a preferred embodiment, the side valance 10 is such that the retaining face 12 is offset inside the window opening. The blind 30 is installed and oriented such that it rides on the outside of the retaining face 12 such that the retaining face 12 is disposed between the window 40 and the blind 30 . The protective material 14 prevents damage to the blind 30 from repeated reciprocation over the side valance 10 . As such, the side valance 10 is dual purpose by, primarily, filling the gaps on either side of the blind 30 to prevent light from passing through and, secondarily, by retaining the blind 30 a fixed distance away from the window 40 which prevents the blind 30 from swaying back toward the window. This retaining feature can be helpful with certain window treatments such as blackout shades because it is desired to maintain sufficient distance from the window for optimal light blocking. It is further apparent that because the retaining face 12 is disposed behind the blind 30 , the side valance 10 will not interrupt the operation of any type of blind 30 that is utilized whether it be a roller blind, slat blind, roman shade, mini blinds, faux wood and wood, roller shades and roman shades, pleated and honeycomb shades, woven wood/bamboo blinds, window shadings, panel tracks, and vertical blinds. Significantly, because the blind 30 rides in front of the retaining face 12 , it can move freely up and down and the blind's slats, if applicable, are free to rotate in any direction as desired. This is a substantial improvement over side channels known in the art that can only be used with roller blinds that have a flat, planar shade. It is further appreciated that the width and length adjustment notches are very useful in fine-tuning the light blocking ability of the side valance, as well as the aesthetics of the overall resultant installation. The width adjustment feature is particularly useful because it 10 allows the side valance 10 to accommodate different sized blinds and the parameters of virtually any window treatment installation. To the extent that the side valance 10 is visible, it can be painted or manufactured in a desired color to match the design of the window treatment or adjacent wall surfaces and other features. Further, the side valance 10 can be easily retrofitted to existing window treatment installations without the need to cut-down or otherwise reconfigure the window treatment itself.
[0044] The instant invention has been shown and described herein in what is considered to be the most practical and preferred embodiments. It is recognized, however, that departures may be made therefrom within the scope of the invention and that obvious modifications will occur to a person skilled in the art.
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A method of preventing light from passing through a gap between a window frame and a window treatment disposed in the window frame, the window frame having a window opening and vertical sides includes the steps of providing an L-shaped light-blocking device with a mounting face, a retaining face extending substantially perpendicular to the mounting face, and at least one frangible width adjustment notch disposed lengthwise along the retaining face, and attaching the mounting face to one of the vertical sides of the window frame to have the retaining face extend from the vertical side between the window treatment and the window opening and block at least some light passing between the window frame and the window treatment.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a thread tension device for overedge sewing machines and particularly to improvements in the disposition of a plurality of tension disk assemblies each having a pair of tension disks.
2. Description of the Prior Art
As is known in the art, overedge sewing machines generally have a needle and a plurality of loopers which cooperate with said needle to form stitches by using a needle thread and a plurality of looper threads. Thread tension devices are provided each in the respective paths of travel of threads from respective bobbins to the needle and loopers.
Such a thread tension device usually comprises a tension disk assembly having a pair of tension disks for holding a thread therebetween, and a spring for pressing one tension disk against the other.
In a conventional overedge sewing machine, thread tension devices are separately prepared in association with the needle and loopers and are independently attached to the sewing machine body.
SUMMARY OF THE INVENTION
Accordingly, an object of the invention is to provide a thread tension device for overedge sewing machines wherein a plurality of tension disk assemblies are unitized so that they can be handled as a single part.
The thread tension device according to the invention has a shaft having a longitudinal dimension in its axial direction. The shaft is supported by support means such as a bracket housed in and fixed to the sewing machine frame so that the axis of the shaft is held in a fixed position. A plurality of tension disk assemblies are mounted on said shaft so that they are spaced apart from each other in axially distributed relationship. Each tension disk assembly includes first and second tension disks forming a pair to hold therebetween a thread to be tensioned. The first tension disk is movable in opposite directions axially of the shaft, while the other or second tension disk is inhibited from moving axially of the shaft in at least one direction away from the first tension disk. Tension adjusting spring means is provided for imparting a resilient force which acts to press the first tension disk against the second tension disk, said tension adjusting spring means having an active portion which applies a resilient force to the first tension disk.
Thus, according to the invention, since a plurality of tension disk assemblies are installed on a single shaft, it is possible to attain unitization using a simple arrangement; therefore, the operation of attaching the thread tension device to the sewing machine body can be simplified.
In a preferred embodiment of the invention, the shaft is installed so that it is rotatable around its axis. Further, the thread tension device according to the invention includes thread tension releasing means which, in response to the rotation of the shaft in one direction, displaces the tension adjusting spring means in a direction opposite to the direction of action of the active portion of the tension adjusting spring means, so as to inhibit the first tension disk from being pressed against the second tension disk, and manual operating means for rotatively operating said shaft in said one direction. Typically, actuation of the thread tension releasing means is realized by a kind of cam device adapted to convert a rotative motion to a linear motion.
According to the preferred embodiment described above, the shaft can be given not only the function of holding a plurality of tension disk assemblies but also the function of motion transmitting means for establishing the thread tension released state in the tension disk assemblies. Therefore, the number of parts which constitutes the thread tension device can be reduced. Further, it is possible to establish the thread tension released state simultaneously in all the tension dsk assemblies mounted on the shaft when the shaft is rotated through the manual operating means.
In a more preferred embodiment of the invention, the device is provided, in addition to the aforesaid arrangement, with return rotation imparting means for imparting to the shaft a rotation counter to the rotation in said one direction or the rotation for releasing the thread tension. This return rotation imparting means can be realized simply by return spring means. In another embodiment this means comprises an arm rotatable integrally with the shaft, a drive shaft rotatively driven during sewing machine operation, and a release lever rotated by the drive shaft. The positional relationship between the arm and the release lever is selected so that the arm is positioned in the path of rotation of the release lever when the thread tension released state is established. In such arrangement, the thread tension released state is canceled when the rotating release lever abutting against the arm rotates the arm.
According to the specific embodiment described above, the thread tension released state is automatically canceled when the rotative operation on the shaft to attain the thread tension released state is stopped or when the sewing machine is started. Therefore, in starting the sewing machine, there is no need to make a visual inspection of the position of the manual operating member or a physical re-operation on the manual operating member for the purpose of imparting a desired tension to a thread, and such an improper operation, such as performing sewing with no tension applied to the threads by error, can be avoided.
These objects 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
FIG. 1 is a front view showing the external appearance of an overedge sewing machine having an embodiment of the invention applied thereto;
FIG. 2 is a front view of a thread tension device housed in the frame 1 of an overedge sewing machine shown in FIG. 1;
FIG. 3 is a sectional view of elements disposed on a shaft 11 in the overedge sewing machine shown in FIG. 1;
FIG. 4 is a sectional view taken along the line IV--IV in FIG. 3;
FIG. 5 is a sectional view taken along the line V--V in FIG. 4;
FIG. 6 is a view similar to FIG. 3, but showing the state in which the thread tension released state is canceled;
FIG. 7 is a sectional view taken along the line VII--VII in FIG. 6;
FIG. 8 is a sectional view taken along the line VIII--VIII in FIG. 7;
FIG. 9 is a front view of a thread tension device according to another embodiment of the invention;
FIG. 10 is an enlarged partial sectional view showing a modification of the embodiment shown in FIG. 9;
FIG. 11 is a front view of a thread tension device according to a further embodiment of the invention;
FIG. 12 is a sectional view taken along the line XII--XII in FIG. 11, showing an interlocking mechanism extending from a push button 35 to a shaft 211 shown in FIG. 11;
FIG. 13 is a sectional view taken along the line XIII--XIII in FIG. 11, showing the positional relationship between an arm 55 and a release lever 47 shown in FIG. 11;
FIG. 14 is a sectional view taken along the line XIV--XIV in FIG. 13, showing how the release lever 49 is installed;
FIGS. 15 and 16 are views corresponding to FIG. 13, for explaining the action of the release lever 49 on the arm 55;
FIG. 17 is a view similar to FIG. 12, but showing another embodiment of the invention; and
FIG. 18 is a front view of a thread tension device according to still another embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
An overedge sewing machine according to a preferred embodiment of this invention, as best seen in FIG. 1, has a thread tension device of the so-called concealed type. Thus, of the elements constituting the thread tension device, only three tension disk assemblies 2, 3a, 3b and three dials 5, 6a, 6b are partly seen projecting out of the frame 1, and also seen is an operating lever 8.
As shown in FIG. 2, a bracket 9 is fixed within the frame 1. The bracket 9 forms two attaching portions 10a and 10b extending upward and opposed to each other. A shaft 11 extends through these attaching portions 10a and 10b and its axis is held in a fixed position by the attaching portions 10a and 10b. The shaft 11 is rotatable around its axis. Further, the shaft 11 has stop rings 12a and 12b fixed thereon so that they respectively contact the opposed surfaces of the attaching portions 10a and 10b, whereby axial movement of the shaft 11 is inhibited.
The aforesaid tension disk assemblies 3a and 3b are mounted on the portions of the shaft 11 which are positioned outside the attaching portions 10a and 10b. To give a description with respect to the left-hand side tension disk assembly 3a, it has first and second tension disks 13a and 14a which forms a pair. A left-hand side looper thread 15a shown in FIG. 1 is held between said first and second tension disks 13a and 14a. A spring support disk 16a is mounted on the shaft 11 adjacent the first tension disk 13a. A spring holder 17a is mounted on shaft 11, and a coil spring 18a is disposed between said spring holder 17 and said spring support disk 16a.
In association with the elements disposed on said shaft 11, the first tension disk 13a, spring support disk 16a and spring holder 17a are movable in opposite directions axially of the shaft 11. The second tension disk 14a is inhibited from moving axially of the shaft 11 in at least one direction away from the first tension disk 13a. In this embodiment, movement of the seoond tension disk 14a away from the first tension disk 13a is inhibited by the second tension disk 14a abutting against the attaching portion 10a. In addition, the second tension disk 14a may be installed so that it does not move axially of the shaft in either direction.
The bracket 9 has attached thereto two vertical shafts 19a and 19b and a horizontal shaft 20 extending at right angles with said vertical shafts 19a and 19b.
To describe the arrangement with respect to the vertical shaft 19a, it has a plate cam 21a attached thereto so that it is slidable in the direction in which the vertical shaft 19a extends, while the horizontal shaft 20 has said dial 6a rotatably mounted thereon. The dial 6a has a pinion (not shown) integral therewith, while the plate cam 21a has a rack (not shown) meshing with said pinion. Therefore, rotative operation of the dial 6a causes the plate cam 21 to move vertically along the vertical shaft 19a. A spring force adjusting lever 23a is attached to the bracket 9 so that it is rotatable around the axis of a pivot pin 22a. A cam follower pin 24a is attached to one end of the lever 23a so that it contacts the camming surface of said cam plate 21a. The other end of the lever 23a engages said spring holder 17a. Thus, when the plate cam 21a is vertically moved by rotative operation of the dial 6a, as described above, the lever 23a is rotated, whereby the position of the spring holder 17a on the shaft 11 is changed. Therefore, the magnitude of the resilient force which the coil spring 18a applies to the first tension disk 13a through the spring support disk 16a is changed and so is the magnitude of the tension applied to the looper thread 15a (FIG. 1) held between the first and second tension disks 13a and 14a.
The above description has so far been given of the left-hand side elements shown in FIG. 2. The right-hand side elements including the tension disk assembly 3b are arranged so as to be symmetrical with respect to the left-hand side elements. By changing the letter "a" included in the reference characters used for the left-hand side elements to "b", the above description applies to the right-hand side elements.
FIG. 3 shows the thread tension released state in which the first tension disks 14a and 14b are inhibited from being pressed against the second tension disks 14a and 14b associated therewith. FIG. 6 shows the thread tension released state being canceled. First, a description will be given in connection with the right-hand side spring support disk 16b. The shaft 11 is provided with a radially projecting pin 25b, while the spring support disk 16b is formed with a cam follower surface 26b capable of contacting a part of the peripheral surface of the pin 25b. The cam follower surface 26b, as best shown in FIGS. 4 and 5 or FIGS. 7 and 8, extends peripherally on one end surface of the spring support disk 16b and has an inclined surface 27b. In the state shown in FIG. 3, the pin 25b is positioned as it has climbed up the inclined surface 27b of the cam follower surface 26b, as shown in FIGS. 4 and 5, while in the state shown in FIG. 6, it is positioned as it has climbed down the inclined surface 27b of the cam follower surface 26b, as shown in FIGS. 7 and 8.
The above arrangement employed in connection with the right-hand side spring support disk 16b is also employed in connection with the left-hand side spring support disk 16a. Since these arrangements are substantially symmetrical with reference to each other, the above description also applies here by changing the letter "b" included in the reference characters used for the right-hand side elements to "a".
The spring support disks 16a and 16b are inhibited from rotating around the axis of the shaft 11 as the latter is rotated. For this purpose, a fixed shaft 28 extends through the opposed attaching portion 10a and 10b and is engaged at its opposite ends with engaging portions 29a and 29b extending from the spring support disks 16a and 16b, respectively. The manner of engagement between the fixed shaft 28 and the engaging portion 29b is shown in FIGS. 4 and 7.
As shown in FIGS. 3 and 6, the fixed shaft 28 is also engaged with the first tension disks 13a and 13b and the second tension disks 14a and 14b, thereby inhibiting rotation of these tension disks 13a, 13b, 14a and 14b; this, however, has nothing to do with the essence of the invention.
In connection with the embodiment described with reference to FIGS. 1 through 8, an operation for establishing the thread tension released state will now be described.
FIGS. 2 and 6 through 8 show the state in which thread tension released state is canceled, i.e., the state in which the first tension disks 13a and 13b are pressed against the second tension disks, respectively, by the springs 18a and 18b. In this state, if the operating lever 8 is rotated through about one fourth revolution counterclockwise as viewed in FIG. 7, or from the left-hand side in FIG. 6, the pins 25a and 25b move along the cam follower surfaces 26a and 26b, respectively. A description will be given of the pin 25b shown in FIGS. 7 and 8. In response to said counterclockwise rotation of the shaft 11, the pin 25b climbs up the inclined surface 27b to assume the position shown in FIGS. 4 and 5. As a result, the spring support disks 16a and 16b are displaced away from the first tension disks 13a and 13b against the resilient forces of the coil springs 18a and 18b, respectively, as shown in FIG. 3. As a result, the thread tension released state is established simultaneously in both of the tension disk assemblies 3a and 3b.
On the other hand, to cancel this thread tension released state, the operating lever 8 is rotated in the reverse direction to establish the state shown in FIGS. 2 and 6. In response thereto, and to give a description of one spring support disk 16b, the pin 25b in the position shown in FIGS. 4 and 5 climbs down the inclined surface 27b of the cam follower surface 26b to assume the position shown in FIGS. 7 and 8. Therefore, as shown in FIGS. 2 and 6, the spring support disks 16a and 16b are brought into contact with the first tension disks 13a and 13b by the coil springs 18a and 18b, respectively. In response thereto, the first tension disks 13a and 13b, under the action of the coil springs 18a and 18b, are pressed against the second tension disks 14a and 14b, respectively.
FIG. 9 shows another embodiment of the invention. In addition, the embodiment shown in FIG. 9 includes a number of elements common to the arrangement shown in FIG. 2, and these common elements are denoted by reference numerals used in FIG. 2 plus "100" to avoid a repetitive description.
The embodiment shown in FIG. 9 is characterized in that the coil springs 18a and 18b are replaced by plate springs 30a and 30b. The plate springs 30a and 30b are fixed at one of their respective ends to spring force adjusting levers 123a and 123b, respectively. The other ends of the plate springs 30a and 30b abut against the first tension disks 113a and 113b. Therefore, the embodiment shown in FIG. 9 is characterized in that the spring support disks 16a and 16b and the spring holders 17a and 17b shown in FIG. 2 are not used, either.
Since the spring support disks 16a and 16b are not used, as described above, the first tension disks 113a and 113b are designed to have the function of the spring support disks 16a and 16b. That is, the first tension disks 113a and 113b are formed with cam follower surfaces 126a and 126b, as shown in dotted lines, while the shaft 111 is provided with pins 125a and 125b.
The embodiment shown in FIG. 9 is not provided with the dials 6a and 6b shown in FIG. 2. Instead, the plate cams 121a and 121b have knobs 31a and 31b directly attached thereto, respectively. These knobs 31a and 31b are exposed from the sewing machine frame 1, as shown in FIG. 1.
In the embodiment shown in FIG. 9, by rotatively operating the operating lever 108 to rotate the shaft 111 around its axis, the first tension disks 113a and 113b are spaced apart from the second tension disks 114a and 114b associated therewith, thereby establishing the thread tension released state. Further, by operating the knobs 31a and 31b to vertically slide the plate cams 121a and 121b, it is possible to adjust the resilient forces exerted by the plate springs 30a and 30b on the first tension disks 113a and 113b.
FIG. 10 shows a modification of the embodiment shown in FIG. 9. More particularly, a return spring 32 in the form of, for example, a torsion spring, is provided in connection with the operating lever 108. The return spring 32 is mounted on the shaft 11 and is engaged at one leg 33 thereof with the operating lever 108 and at the other leg 34 with the bracket 109. When the operating lever 108 is rotated to establish the thread tension released state, the return spring 32 enables the operating lever 108 to automatically assume the position shown in FIG. 10 when the rotative action thereon is removed. Therefore, in starting the sewing machine after the thread tension released state has been established, it is no longer necessary to operate the operating lever 108 again.
In addition, the arrangement incorporating the return spring 32 can also be employed in the embodiment shown in FIG. 2.
FIGS. 11 through 16 show still another embodiment of the invention. This embodiment has a number of elements common to the embodiment described with reference to FIGS. 1 through 8. Thus, to avoid a repetitive description, reference characters including numerals used in the first embodiment plus "200" will be used.
This third typical embodiment is characterized by the construction for rotatively operating the shaft 211. More particularly, as shown in FIGS. 11 and 12, a push button 35 is installed outside the frame 201 and is fixed on the upper end of a vertically extending actuator plate 36. The actuator plate 36 is formed with a vertically extending guide opening 37 in which two guide pins 38 and 39 arranged one above the other are received. The guide pins 38 and 39 are fixed on the frame 201 in a manner not shown. Thus, the actuator plate 36 is held for vertical movement in a predetermined range of length by the guide pins 38 and 39 received in the guide opening 37.
The actuator plate 36 is formed with vertically spaced engaging portions 40. On the other hand, an L-shaped lever 42 is turnably mounted on a shaft 41 fixedly installed in the frame 201. One end of the lever 42 is provided with a pin 43 engaged by the engaging portions 40.
An arm 44 is attached to the shaft 211 so that it is rotated with the latter, said arm 44 being operatively connected to the lever 42 by a link 45.
In such an arrangement, when the push button 35 is pushed downward from the position shown in FIG. 12, the L-shaped lever 42 is turned to the position shown in phantom lines. The arm 44 is thereby turned to the position shown in phantom lines through the link 45 and, in response thereto, the shaft 211 is turned through a predetermined angle. In response to such turning movement of the shaft 211, the thread tension released state is established or canceled, as in the preceding embodiments. In addition, in FIG. 12, it is to be understood that when the arm 44 is in the phantom line position, the thread tension released state is established, and that when it is in the solid line position the thread tension released state is canceled.
The embodiment being described is arranged so that when the sewing machine is started even in the thread tension released state, this state is automatically canceled. This arrangement will now be described with reference to FIGS. 11 and 13 through 16.
The sewing machine is provided with a motor for driving various actuating parts, and the main shaft is rotated by this motor. A drive shaft 46 shown in FIG. 11 may be such a main shaft or some other shaft than the main shaft to which rotation is transmitted from the main shaft. A collar 47 is fixed on the drive shaft 46 and has a release lever 49 attached to the boss portion 48 thereof by a stop ring 50 which prevents its axial movement, said release lever 49 having two diametrically projecting wings. The collar 47 is provided with two diametrically spaced stoppers 51 and 52. The release lever 49 is turnable relative to the collar 47, the range of turning movement of the collar 47 relative to the release lever 49 being limited by the release lever 49 abutting against said stoppers 51 and 52. A cushion spring 53 in the form of a torsion spring is mounted on the boss portion 48 of the collar 47. One end of the cushion spring 53 is fixed to the boss portion 48 and the other end to the release lever 49. The cushion spring 53 urges the release lever 49 to turn in the direction of arrow 54 until the release lever 49 abuts against the stoppers 51 and 52.
On the other hand, an arm 55 is attached to the shaft 211 for rotation with the latter. The front end of the arm 55 is provided with a pin 56. The position of the pin 56 is selected so that it is in the plane of rotation of the release lever 49, as seen from FIG. 11.
The position of the arm 55 show in FIG. 13 corresponds to the state in which the thread tension released state is canceled, namely, the operating state of the sewing machine. In such operating state, the drive shaft 46 is rotated in the direction of arrow 54 and with this rotation the release lever 49 is also rotated in the same direction; however, the pin 56 is not positioned in the path of rotation of the release lever 49. Therefore, the presence of the pin 56 and arm 55 has no influence on the rotation of the drive shaft 46.
On the other hand, the state shown in FIG. 15 corresponds to the state in which the shaft 211 is rotated through about one fourth revolution to establish the thread tension released state, as described above. When the sewing machine is started in this condition, the drive shaft 46 is rotated in the direction of arrow 54 and in response thereto the release lever 49 is also rotated in the same direction. In the state shown in FIG. 15, the pin 56 is positioned in the path of rotation of the release lever 49, and when the release lever 49 is rotated in the direction of arrow 54, it abuts against the pin 56, as shown in FIG. 16. It would be expected that the instant the release lever 49 abuts against the pin 56, a high load would be imposed on the drive shaft 46. In this embodiment, however, such instantaneous imposition of a high load on the drive shaft is prevented. More particularly, immediately after the release lever 49 strikes the pin 56, the drive shaft 46 is rotated together with the collar 47 ahead of the release lever 49. In addition, the degree by which the drive shaft 46 moves ahead of the release lever 49 depends on the strength of the cushion spring 53. Eventually, the drive shaft 49 rotates with the drive shaft 46, progressively displacing the arm 55, as shown in phantom lines in FIG. 16, finally to the position shown in FIG. 13. In this manner, when the sewing machine is started, the thread tension released state is automatically canceled.
The fact that the release lever 49 is installed for rotation through a predetermined angle relative to the drive shaft 46 and has the cushion spring 53 further provides the following advantages. Suppose that the drive shaft 46 is stopped with the release lever 49 in the dotted position shown in FIG. 13. At this time, it is expected that if the arm 55 is turned to the position shown in FIG. 15 in order to establish the thread tension released state, the pin 56 strikes the release lever 49, which means that a high load is involved in an operation for establishing the thread tension released state. However, where the release lever 49 is turnably attached to the drive shaft 46 as in this embodiment, it is possible to allow the release lever 49 alone to escape from the path of travel of the pin 56 in response to the movement of the pin 56 described above without rotating the drive shaft 46. Therefore, there will not be much of a load involved in an operation for establishing the thread tension released state. Further, even if the release lever 49 is in the solid line position shown in FIG. 16 when the drive shaft 46 is started subsequent to an operation for establishing the thread tension released state, imposition of a high load on the motor in starting the sewing machine can be prevented since the drive shaft 46 can be rotated ahead of the release lever 49.
FIG. 17 shows still another embodiment of the invention. This figure corresponds to FIG. 12, and it can be regarded as a modification of the third typical embodiment described above.
Referring to FIG. 17, a return spring 57 in the form of a torsion spring is disposed in connection with the L-shaped lever 42. One end of the return spring 57 is engaged with the L-shaped lever 42 and the other end with an attaching portion 58 extending from the bracket (not shown). The return spring 57 serves to constantly urge the lever 42 to turn clockwise. Therefore, employment of the construction shown in FIG. 17 ensures that if the operation on the push button 35 is stopped, the thread tension released state is automatically canceled without having to use said release lever 49.
In the embodiments described so far, two tension disks 3a and 3b for imparting tension to two looper threads 15a and 15b shown for example in FIG. 1 have been unitized on a single shaft 11. However, three tension disk assemblies 2, 3a and 3b, with the tension disk assembly 2 shown in FIG. 1 included, may be installed on a single shaft.
FIG. 18 shows such an example, in which three tension disk assemblies 60, 61 and 62 are mounted on a shaft 59 so that they are spaced apart from each other in an axially distributed relationship. Coil springs 63, 64 and 65 are associated with said tension disk assemblies 60, 61 and 62 and spring holders 66, 67 and 68 are screwed on the externally threaded portions 69, 70 and 71 of the shaft 59. Dials 72, 73 and 74 are rotatably mounted on the shaft 59 for rotating the spring holders 66, 67 and 68, respectively, relative to the shaft 59.
In this embodiment, if the dials 72, 73 and 74 are rotatively operated, the spring holders 66, 67 and 68 are displaced axially of the shaft 59 and hence the resilient forces of the coil springs 63, 64 and 65 acting on the tension disk assemblies 60, 61 and 62 are adjusted.
In FIG. 18, the shaft 59 has been installed so that it does not rotate around its axis relative to support means 75; however, the shaft 59 may be installed so that it can be rotated around its axis relative to the support means 75 by manual operating means to thereby establish the thread tension released state in each of the tension disk assemblies 60, 61 and 62.
Although the present invention has been described and illustrated in detail, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, the scope of the present invention being limited only by the terms of the appended claims.
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A plurality of tension disk assemblies in an overedge sewing machine are disposed on a shaft supported for rotation around its axis and are spaced apart from each other in an axially distributed relationship. Each tension disk assembly comprises first and second tension disks forming a pair for holding therebetween a thread to be tensioned. The first tension disk is movable in opposite directions axially of the shaft, and the second disk is substantially immovable in the direction of the axis of the shaft. The resilient force of a spring acts on each first tension disk, whereby the latter is pressed against the second tension disk associated therewith. When the shaft is turned, as by a manual operating lever, this rotary motion is converted into a linear motion through a cam device. This linear motion removes the resilient force of the spring from the first tension disk. Thus, a thread tension released state is established simultaneously in the plurality of tension disk assemblies.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a multi-nozzle weft insertion device for a fluidic jet shuttleless-loom and, more particularly, to a high-performance multi-nozzle weft insertion device which can guide wefts ejected from nozzles precisely into a desired weft-path and insert them into a shed of warps, using the hydrodynamic properties of streamlined objects.
2. Description of the Related Art
A fluidic jet shuttleless-loom is a type of loom in which weft insertion is performed by enveloping the weft in a jetted fluid and using the friction therebetween to move the weft by jet propulsion. A loom using air as an actuating fluid is called an air-jet loom and a loom using water as an actuating fluid is called a water-jet loom.
In the air-jet loom using compressible and easily diffusible air, it is necessary to control the diffusion of the jetted fluid and keep the wefts together, therefore a ledge profile reed is provided having a surface deformed into a channel surrounding the weft-path. Where the ledge profile reed is used in the air-jet loom for single-nozzle weft insertion, that is, the insertion of one weft, no problems occur because it is only necessary to sight the jet orifice of the nozzle into the center of the reed channel. However, where the same reed is used for multi-nozzle weft insertion, that is, the insertion of many different wefts blown from different nozzles, a problem occurs in adjusting the propulsion sight or line of flight of the wefts. It is almost impossible to sight all of the nozzles N, N'. . . at the center of the channel, and, as a result, the discharged weft Y runs against the entrance wall of the channel G of the reed R, resulting in weft insertion failure.
To solve the above-discussed sighting problem, a system for moving nozzles one at a time to individually sight along the weft-path was designed, as disclosed in Japanese Patent Early Publication No. 55-142747. This system, however, cannot be structurally adapted to recent large-sized air-jet looms which require that the nozzles be moved quickly and constantly. In addition, the large systems need to hold the nozzles N, N'. . . together with the reed R in a fixed position on a reed support F as shown in FIG. 1, where D indicates weft measuring and storing devices and Y indicates wefts.
The conventional fixed multi-nozzle weft insertion device overcomes weft insertion failure by (a) reducing nozzle size or (b) enlarging the channel opening as disclosed in Japanese Utility Model Early Publication No. 59-10087.
SUMMARY OF THE INVENTION
It is an object of the present invention to overcome the above-mentioned problems by providing a multi-nozzle weft insertion device that produces a jet flow from a nozzle located out of the weft-path, as a streamlined fluid flow by hydrodynamic means, and that converges the weft carried by the jet flow gradually to the line of sight of the weft-path to thereby insert the weft along the weft-path.
It is another object of the present invention to provide a high-performance multi-nozzle weft insertion device that is simple in structure, operates reliably and loses very little jet energy.
It is a further object of the present invention to provide a multi-nozzle weft insertion device that facilitates the standardization of machine parts and products and has good mass-production capability.
It is an additional object of the present invention to provide a weft insertion device that prevents entanglement of the wefts.
It is still another object of the present invention to provide a weft guide that can control the horizontal and vertical components of weft movement separately or in combination.
The present invention provides a high-performance multinozzle weft insertion device which guides wefts ejected from nozzles into a weft path using the hydrodynamic principles of the Coanda effect. Each group of nozzles includes a weft guide that changes in shape as the distance from the nozzles increases. The changing shape causes air flow to adhere to the guide and directs the weft toward the center of a reed channel. Partitions can be included between guide sections to control air diffusion to prevent weft entanglement. Guides of different shapes the horizontal and vertical components of weft movement to be controlled independently or in combination.
These together with other objects and advantages which will be subsequently apparent, reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawing forming a part hereof, wherein like numerals refer to like parts throughout.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a conventional multi-nozzle weft insertion device of a fixed-nozzle type;
FIG. 2 is a perspective view of a first embodiment of the present invention showing the nozzle end;
FIG. 3 is a front view of the second embodiment showing the jet orifice end;
FIG. 4 is a sectional view along the line A--A' of FIG. 3;
FIG. 5 is a perspective view of a second embodiment of the present invention showing the nozzle end;
FIG. 6 is a front view of the second embodiment showing the jet orifice end;
FIG. 7 is a view along the line B--B' of FIG. 6;
FIG. 8 is a perspective view of a third embodiment of the present invention showing the nozzle end;
FIG. 9 is a front view of the third embodiment showing the jet orifice end;
FIG. 10 is a sectional view along the line C--C' of FIG. 9;
FIG. 11 is a view showing weft blowing conditions of the third embodiment;
FIG. 12 is a perspective view of a fourth embodiment of the present invention showing the nozzle end;
FIG. 13 is a front view of the fourth embodiment showing the jet orifice end;
FIG. 14 is a sectional view along the line D--D' of FIG. 13;
FIG. 15 is a view showing the weft blowing condition of the fourth embodiment;
FIG. 16 is a perspective view of a fifth embodiment of the present invention constructed as a double-nozzle weft insertion device;
FIG. 17 is a front view of the fifth embodiment showing the jet orifice end;
FIG. 18 is a sectional view along the line E--E' of FIG. 17;
FIG. 19 is a perspective view of a sixth embodiment of the present invention constructed as a double-nozzle weft insertion device;
FIG. 20 is a front view of the sixth embodiment showing the nozzle end portion;
FIG. 21 is a section view along the line F--F' of FIG. 20;
FIG. 22 is a perspective view of a seventh embodiment of the present invention constructed as a double-nozzle weft insertion device having a streamlined weft guide provided for only one of the two nozzles;
FIG. 23 is a perspective view of the eighth embodiment as seen from a first side;
FIG. 24 is a perspective view of the eighth embodiment as seen from a second side; and
FIG. 25 is a front view of the eighth embodiment showing the jet orifice end.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The first embodiment of the present invention illustrated in FIGS. 2 to 4 is a quadruple-nozzle weft insertion device having a weft guide 2a with a bullet-like or conoid shape. The weft guide 2 is a streamlined object, that is, an object whose curvature does not disrupt the smooth flow of fluid thereacross and causes a high velocity air stream to adhere thereto without causing turbulence. The diameter of the guide 2 increases until a mid point of the streamlined portion and decreases thereafter until it terminates with a pointed end. The weft guide 2a is mounted in the center between the four nozzles 1, 1', 1" and 1'", and positioned in a coaxial relationship with the weft-path line of sight 1--1. The guide 2a is positioned to contact the pressurized air discharged from the nozzles. The high velocity air streaming from each nozzle carries a weft. The air stream tends to adhere to the guide 2 in accordance with the Coanda effect. Since the air stream is carrying the weft in the direction of the pointed end which is on the line of sight of the desired weft path. As a result, the wefts are directed toward the center of the reed channel by floating in the air stream redirected by the guide 2.
A second embodiment of the present invention illustrated in FIGS. 5 to 7 is a quadruple-nozzle weft insertion device having a spindle-like, streamlined weft guide 2b which is also mounted in the center between the four nozzles 1, 1', 1" and 1'", and positioned in a coaxial relationship with the weft-path line of sight 1--1. This embodiment operates in a manner similar to the first embodiment.
A third embodiment of the present invention illustrated in FIGS. 8 to 10 is a quadruple-nozzle weft insertion device having an ovoid-like, streamlined weft guide 2c which is mounted in the center between the nozzles 1, 1', 1" and 1'", and positioned in a coaxial relationship with the weft-path line of sight 1--1.
FIG. 11 illustrates a modification of the guide 2c of FIGS. 5-7 to provide a blunted tip. The blunted tip improves alignment with the weft-path line of sight 1--1. FIG. 11 also illustrates the operation of the present invention. As the weft Y leaves a nozzle, for example, nozzle 1', because it is being carried by the air stream, it hugs or follows the contour of the guide 2c until it enters the channel G formed by reeds R.
A fourth embodiment of the present invention illustrated in FIGS. 12 to 14 is a quadruple-nozzle weft insertion device with an ovoid-like, streamlined weft guide 2d having partition wings 21. The wings 21 control fluid diffusion in the forward direction of the jet orifices to prevent the end of respective wefts blown from the nozzles 1--1'" from getting tangled. The wings 21 stop entanglement of the wefts by not allowing the diffusing air to mix and swirl as it passes adjacent to guide 2d. As in the third embodiment, the weft guide 2d is mounted in the center between the four nozzles 1, 1', 1" and 1'", and positioned in a coaxial relationship with the weft-path line of sight 1--1.
FIG. 15 illustrates how the fourth embodiment including wings or partitions 21 operates. Once again, as each weft Y leaves a nozzle carried by an air stream, it follows the contour of the guide 2d while remaining between the wings 21 and is propelled down the center of channel G between reeds R along the weft-path line of sight 1--1.
A fifth embodiment of the present invention illustrated in FIGS. 16 to 18 is a double-nozzle weft insertion device having a partition wing 21 for partitioning two superposed nozzles 1 and 1'. The partition wing 21 has its upper and lower surfaces swelled into a long, elliptical streamlined shape to form a weft guide 2e. This embodiment operates in a manner similar to previous embodiments in that the weft carried by the air stream follows the contour of the swell to be positioned in the center of a channel. However, this embodiment only provides minimal weft movement along the horizontal axis while providing substantial weft movement along the vertical axis.
A sixth embodiment of the present invention illustrated in FIGS. 19 to 21 is a double-nozzle weft insertion device having a sheet-like, streamlined weft guide 2f which is thicker in the middle and which is positioned between the two superposed nozzles 1 and 1". This embodiment is used when the weft only needs to be curved in one direction, in this instance vertically.
A seventh embodiment of the present invention illustrated in FIG. 22 is a double-nozzle weft insertion device in which the nozzles 1 and 1' are horizontally and adjacently positioned side by side and a streamlined weft guide 2g is provided to interact only with the jet orifice of the nozzle located on the outer side of the reed R to hydrodynamically, due to the Coanda effect bring the blown weft into the line of sight of the weft-path. In this embodiment, a sheet-like streamlined weft guide 2g is provided at the outer surface of partition wing 21 inserted between the nozzles 1 and 1'. The weft guide 2g moves only one weft and moves it in a horizontal direction.
An eighth embodiment of the present invention illustrated in FIGS. 23 to 25 is a modification of the fourth embodiment described herein, in which partition wings 21 are positioned adjacent to the jet orifice of the nozzles 1, 1', 1" and 1'" and weft guides 2d and 2f, having different shapes and/or streamline curvatures (see particularly FIG. 25), are provided according to the locational relationship between the jet orifice and the weft-path. The different shaped guides 2d and 2f will move the wefts in a different manner toward the channel. With respect to FIG. 25, weft guide 2d will move a weft both horizontally and vertically while guide 2f will move the weft vertically. The guide of FIGS. 23-25 is particularly suitable for a channel with a weft path line of sight offset toward the B side of the guide as illustrated in FIG. 25. Thus, the shape of the guide depends on the distance and direction of desired weft movement. Selection of the appropriate weft guide for a particular situation depends on the quality and weight of the weft and is within the ordinary skill in the art.
The various embodiment of the present invention have been described above and include in common a weft guide streamlined toward the direction of the jet flow on at least one of the nozzles 1, 1', 1" and 1'". The weft guide for each jet orifice of the nozzle causes the weft Y blown from each nozzle along with the actuating fluid, to converge along a boundary-layer flow which is produced by the fluid on the streamlined wall surface of the guide. The weft is moved gradually toward the weft path line of sight 1--1, by moving adjacent to the wall surface and, as a result, will be guided precisely toward the center of the channel G which is an the extension of the line of sight 1--1, as particularly illustrated in FIGS. 11 and 15.
According to the present invention, a weft blown from each nozzle will travel along the wall surface of the streamlined weft guide under the influence of the boundary-layer flow formed on the circumferential surface of the guide and will be gradually guided toward the weft-path line of sight without meeting any fluidic resistance. The present invention will not cause weft insertion failure, does not require such conventional steps as miniaturizing the nozzle or enlarging the channel and assures weft insertion into the reed channel. The weft insertion device according the present invention will improve performance and reliability using a mechanism which is much simpler than other conventional mechanisms used to prevent failure during insertion, and furthermore, the present invention will improve the performance of a multi-nozzle weft insertion device for a fluidic jet shuttleless-loom represented by an air-jet loom.
The many features and advantages of the invention are apparent from the detailed specification and thus it is intended by the appended claims to cover all such features and advantages of the invention which fall within the true spirit and scope thereof. 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 illustrated 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 multi-nozzle weft insertion device which includes a weft guide which uses the hydrodynamic principles of fluid flow around a streamlined object to direct wefts from plural nozzles into a channel which can be centrally located with respect to the nozzles. The wefts are pulled along the contour of the guide, which is streamlined toward the channel, by a flow of high pressure air. The wefts can be kept from becoming entangled by adding a partition wing between the nozzles. If the channel is not centrally located each weft can be made to approach the channel by moving a different distance and from a different angle by varying the shape of the guide associated therewith. Both horizontal and vertical deflection of the weft can be controlled by shape.
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BACKGROUND OF THE INVENTION
This invention relates to a device for cutting fibrous material into shorter lengths for use in the textile industry and more particularly the invention relates to an outside-in tow cutter.
Modern devices for cutting fibrous material, tow, in the textile industry are, in general, improvements on the basic type tow cutter as patented by Garland Keith in U.S. Pat. No. 3,485,120 in 1069. Such apparatus are designed so that a number of layers of uncut tow are wrapped spirally on the radially outturned cutting edges of a plurality of blades whose edges are uniformly spaced from the center of rotation of the reel upon which the blades are mounted. Such reels are constructed of a disc with a center mounted hub for powered rotation, and a ring that supports one end of the cutting blades. The disc and ring thus form flanges between which the tow wound on the reel is held. A cylindrical pressure roller fits snugly between the flanges and its periphery is held at a uniform distance from the cutting edges of the blades, thereby forcing the tow radially inward to the cutting blades. Such machines were initially used for process speeds up to as high as 500 meters per minute; however, with the development of higher speed spin-draw lines in the man-made fiber industry, speeds have increased substantially above 500 meters per minute and centrifugal force has become a major factor in the function of the Garland Keith concept. With higher rotational speeds the mass of uncut tow plus the mass of cut staple inside the cutting edges of the blades becomes a substantial factor.
It is therefore an object of this invention to provide a tow cutter capable of operating at speeds in excess of 2,000 meters per minute.
It is another object of the instant invention to reduce the mass of cut fibrous material carried by the reel during operation thereby reducing the centrifugal forces and consequent stress placed on the uncut tow.
Yet another object of the invention is to provide a more gradual cutting action between the pressure roller and the cutting blades thereby reducing the impact forces of high speed operation.
Still another object of the invention is to provide a tow cutter which is self-threading at initial start-up and can be threaded with a second tow while a first tow is running on the reel.
SUMMARY OF THE INVENTION
These objects are advantageously accomplished in the present invention which comprises an outside-in tow cutter wherein the axis of rotation is preferentially horizontal. The reel of the present invention carries a mounting hub which provides drive power to an inner disc which in turn cooperates with radially disposed cutter blades and associated blade support posts. An outer ring of the instant invention has an internal diameter slightly smaller than the diameter of the circle defined by the path of movement of the cutting edges of the blades, whereby the blade support posts are operatively connected in a unique manner to the interior rim of the outer ring and to the inner disc rather than being seated in the outer ring as is common practice. The outer ring also carries a lip or ring flange which projects outwardly from the reel and extends parallel to the axis of rotation thereof. The ring flange is conically inclined so that it flares outwardly from the junction of the outer ring with the blade support posts. The ring flange cooperates with a hinged discharge housing or hopper to form a substantially air-tight seal therebetween. Sub-atmospheric pressure is induced within the reel and hopper to generate airflow from the reel housing through a discharge housing thereby carrying cut staple away from the reel.
Disposed in close proximity to said reel is an input housing which is cooperatively positioned to advantageously introduce tow into the reel whereupon the air currents generated by the sub-atmospheric pressure carry the tow onto the reel until successive layers are accumulated thereon. In order to minimize impact forces heretofore encountered, the diameter of the pressure roller has been increased to exceed one-half the diameter of the cutter reel.
BRIEF DESCRIPTION OF DRAWINGS
Apparatus embodying features of our invention is illustrated in the accompanying drawings, forming a part of this application, in which:
FIG. 1A is a front elevational view of the tow cutter showing its housing broken away and in section;
FIG. 1B is a side elevational view of the tow cutter, with parts being broken away and in section;
FIG. 2 is a sectional view of the reel assembly taken generally along the line 2--2 of FIG. 1A, with parts being omitted for the sake of clarity;
FIG. 3 is an isometric view depicting the tow inlet housing in conjunction with the reel assembly and pressure roller; and
FIG. 4 is a sectional view through the cutter blade and its support post.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings for a better understanding of our invention, FIGS. 1A and 1B provide an overall view of the tow cutter assembly 10 from which it will be readily apparent that the tow cutter is horizontally oriented rather than vertically oriented, as has heretofore been the usual practice. In accordance with such conventional practice a drive motor 12 is utilized to drive a timing belt 14 which is operatively connected to a drive shaft 16 which in turn is connected to a cutter reel assembly indicated generally at 18. The drive shaft 16 is supported by drive shaft mounts 17 which are also conventional for horizontally mounted drive shafts. The cutter reel assembly 18 is shown more clearly in FIG. 2 and will be described in more detail hereinafter. Cooperatively positioned for normal interaction with the cutter reel assembly 18 is a pressure roller 20 which is held in cooperative position by roller mounting arms 24. The arms 24 may be adjusted in a conventional manner by a pressure roller adjustment assembly indicated generally at 22.
In order to overcome the centrifugal loading inherent in a cutter reel of a tow cutter it is necessary to reduce the mass of fibrous material being carried by the reel. One expedient is to reduce the distance between the components of the cutter reel assembly 18. With reference to FIG. 2 the cutter reel assembly is comprised of an inner plate 38 which is operatively connected by a mounting flange 39 to a drive shaft 16. The inner plate 38 and an outer ring 40 have positioned therebetween a plurality of angularly spaced cutter blades 44. Each of the cutter blades 44 is held in place by an annular blade retainer 42 and a blade support post 46. The blade retainer 42 is attached to the inner plate 38 by blade retainer fasteners 43. The blade support posts 46 are secured tightly in holes in the inner plate 38 and are bolted or otherwise attached to the inner surface of the outer ring 40 by radial fasteners 54 or other attaching means.
To reduce the centrifugal loading on the cutter reel assembly, the space between inner plate 38 and the outer ring 40 is decreased, thereby decreasing the transit distance from the innermost edges of the cutter blades 44 to the outermost restricted diameter of ring 40. This narrowing of the spaces between inner plate 38 and the outer ring 40 is practical because the higher the speed of spinning and drawing, the smaller the tows may be to accomplish the desired production rate.
It is common in conventional tow cutters, utilizing the basic Garland Keith principle, for an accumulation of staple to build up in a somewhat triangular shape inwardly of the blades as the staple slides over the inner lip of the ring. It should be noted that the instant design has reduced the inner lip of the outer ring 40 such that its inner diameter is only slightly less than the diameter of the circle defined by the path of movement of the cutting edges of cutting blades 44. A difference of less than 15 mm is deemed satisfactory. With this novel construction the blade support posts 46 fit against the inside surface 48 of outer ring 40. This requires the blade support posts 46 to be machined from larger sections of either round or rectangular material. The posts themselves are machined to fit accurately against the cylindrical inner surface 48 of outer ring 40. Radial fasteners 54 for the blade support posts may hold the outer ring 40 to the machined surface of blade support posts 46. With reference to FIGS. 2 and 4, it can be seen that the portion of blade support posts 46 intermediate inner plate 38 and outer ring 40 have been beveled or shaped in a triangular manner to facilitate the smooth transfer of cut staple from the blade edges to the inside of reel assembly 18. Blade support posts 46 have a longitudinal blade slot 58 within which cutter blade 44 is seated. The beveled surfaces 56 of blade support posts 46 are inclined whereby they flare outwardly away from the portion of cutting blade 44 intermediate inner disc 38 and outer ring 40.
Referring to FIG. 2 there is a sloping conical surface 52 which flares outwardly from the junction of the outer ring 40 and blade support post 46. The conical surface 52 terminates in the outer lip 50 which projects from outer ring 40 in a direction parallel to the axis of rotation of the reel assembly 18. The outer lip 50 has been extended beyond the distance required for structural support for outer ring 40, as shown. Outer ring 40 thus provides a conventional radial flange 55 for retaining uncut tow within the reel assembly 18 and the axially extending lip 50, said flange and lip joining on the outer surface of ring 40 to form a shoulder 51. A staple receiving hopper 28 is provided which fits in close juxtaposition to shoulder 51 such that lip 50 extends within hopper 28. The extension of lip 50 and the conical surface 52 within the hopper 28 is desirable for two reasons. First, the conical surface 52 must support the fibers as they flow out of the reel assembly 18 and direct the cut fibers into hopper 28. Therefore the conical surface 52 must extend inside hopper 28 so that the cut fibers are guided into hopper 28 without the possibility of being slung out through the space between outer ring 40 and hopper 28. Secondly, the conical surface 52 must support the fibers that may be cut at one end only, i.e. by only one blade. Such fibers would be lying against the conical surface 52 under the influence of centrifugal force and if such fibers extended into the airstream within hopper 28 whereby there exists very high turbulence they would entangle cut staple passing thereby in close proximity and would also pull their uncut ends circumferencially across the adjacent blade resulting in unequal staple lengths. Therefore the distance from the cutting edge of the cutter blade 44 to the outer portion of the conical surface 52 is designed to exceed the distance between the cutter blades spaced about the reel assembly 18.
Hopper 28 fits snugly about the shoulder 51 formed by lip 50. This snug fit, in effect a labyrinth seal, not only causes proper discharge of the cut fiber into discharge hopper 28 but also allows the development of subatmospheric pressure inside the reel assembly 18. Discharge hopper 28 has a lower discharge outlet to a lower discharge section 30 which in turn communicates with a fan or air pump 32 which induces a subatmospheric pressure that reaches into the blade area of the reel assembly 18. It will be noted that discharge hopper 28 has a cover section 25 and a mounting plate 27 and is mounted on hinges 29 which are aligned in a plane which extends through the overlapping fit between outer ring 40 and discharge hopper 28. This hinged mounting allows discharge hopper 28 to be swung away from the reel assembly 18, thereby allowing inspection of reel assembly 18 or removal and reinstallation of reel assembly 18 in a rapid and efficient manner. Inasmuch as hopper 28 is hingedly mounted and yet is connected to the lower discharge section 30, in order to maintain the subatmospheric pressure within the reel assembly 18 a seal 31 is provided between hopper 28 and the lower discharge section 30. The seal 31 is preferentially formed of a resilient flexible material to provide a substantially uniform and long-life seal which is attached to the lower extremity of the hopper 28 where hopper 28 is in close proximity to lower discharge section 30. Hopper 28 will provide the outer seal for the reel assembly 18, and an intermediate panel 26 positioned behind reel assembly 18 and pressure roller 20 separates these mechanisms from the power driving section of the tow cutter 10 and provides a substantially sealed area about the reel assembly 18.
The subatmospheric pressure induced inside the reel assembly 18 allows the tow cutter 19 to be self-threading at the high speed at which the tow is being fed into cutter 10. In the spin-draw processes producing the high speed tows, the spinning and drawing operations cannot be stopped without a costly restart process. Therefore, the cutter must be threaded up "on the fly". Conventionally this is accomplished with the use of aspirator guns that use the injector principle to collect the tow into the gun barrel and deposit it through a connecting pipe system into a waste collector while switching from one cutting machine to another or while a relatively short shutdown occurs during rethreading when only a single cutter is being used. By providing subatmospheric pressure within reel assembly 18 great enough to overcome the centrifugal fan action of the fast rotating cutter blades 44, air is introduced inwardly through the spaces between blades 44. The proven result of the subatmospheric pressure inwardly of the blades 44 is that a tow introduced into the space between the outer ring 40 and the inner plate 38 outside cutter blades 44 is indeed pulled toward blades 44 and wraps itself around the cutting edges of blades 44, thus the cutting operation automatically commences when the speed of the tow being fed into the cutter is coordinated with the speed of rotation of the cutter reel assembly 18. Secondly, the subatmospheric pressure within reel assembly 18 and hopper 28 does induce air currents through the labyrinth seals between the reel assembly 18 and hopper 28 after the cutter blades 44 have been covered by the wrapped tow. These air currents tend to lift the cut fiber off the conical surface 52 and cause the fibers to follow the airstream out of hopper 28 into lower discharge section 30.
In order to take advantage of the self-threading feature of the instant tow cutter, a tubular tow inlet housing 36, shown in FIG. 3, may be provided which is open to the outside of the cabinet 11 of two cutter 19 to define an inlet 60. The discharge end 62 of the inlet housing 36 is located in close proximity to the reel assembly 18 such that tow directed therethrough is directed between the flanges of the reel assembly 18. This outlet 62 has an arcuate terminus 64 which fits in close relation to the flanges of reel assembly 18 so that on the initial thread-up when the reel assembly 18 has no tow wrapped around cutter blades 44, the subatmospheric pressure hereinabove described will create an airstream flowing through tow inlet housing 36, which will enable the tow to be threaded up at high speeds with the use of an aspirator gun. The aspirator gun must be placed in close proximity to inlet 60 so that the air currents through tow inlet housing 36 may take the tow away from the gun and into the housing. The discharge opening of arcuate terminus 64 must be smaller than the distance between the inner plate 38 and outer ring 40 in order for the tow to be properly fed onto reel assembly 18. It should be clear at this point that seal 31, the labyrinth seal between outer ring 40 and hopper 28, and the seal provided by intermediate panel 26 provides a housing which is sufficiently air-tight that the subatmospheric pressure within this assembly will force air to be taken in through tow inlet housing 36 rather than allowing air to flow freely through the reel between all blades. Tow inlet housing 36 is mounted on a hinge 65 and urged into close proximity at the arcuate terminus 64 thereof to reel assembly 18 by a spring 66 or other resilient means. This hinged construction allows tow inlet housing 36 to pivot away from reel assembly 18 when an occasional tow wrap-up, or "blow-up" as it is commonly called, on the reel occurs. When the tow wrap-up occurs hinge 65 allows tow inlet housing 36 to simply swing away thereby avoiding damage to the housing. Of course tow inlet housing 36 may also be manually pivoted away from reel assembly 18 for convenience in removing and reinstalling the cutter reel assembly 18.
It is sometimes necessary to thread up a second tow while a first tow is already running on reel assembly 18. Under such conditions, the first tow will have blocked off the air movement between blades 44 of the reel assembly 18 and therefore the subatmospheric pressure used to thread up the first tow is not available for threading up the second tow. However, hinged tow inlet housing 36 is designed and positioned relative to the tow inlet guides 34 and tow guide wheel 35 that a second tow may be brought in close proximity with inlet 60 to tow inlet housing 36 by means of an aspirator gun. The air pressure of the aspirator gun may then be reduced so that the second tow will be mechanically entrained by the first tow as it enters tow inlet housing 36. The converging surfaces of tow inlet housing 36 will force the second tow to be entrapped between the first tow and the tow wrapped around reel assembly 18. Once the leading end of the second tow is wrapped between the first tow being wound on the reel and the tow already on reel assembly 18 the second tow will be positively pulled onto reel assembly 18. To accomplish this, the discharge opening of the tow inlet housing should be slightly narrower than the distance between the flanges of the reel. Of course, the overall configuration of tow inlet housing 36 is such that inlet end 60 is larger than discharge end 62 with the body of tow inlet housing 36 tapering from inlet 60 to discharge end 62 at its arcuate terminus 64. In addition guides 34 and a guide wheel 35 are properly positioned to prevent the two tows hereinabove described from touching each other until the moment that the second tow is released by the aspirator gun into inlet 60.
With reference to FIG. 1A it can be seen that pressure roller 20 has a diameter which is greater than one-half the diameter of reel assembly 18. Previous pressure rollers employing the principles of the Garland Keith U.S. Pat. No. 3,485,120 have used pressure rollers smaller than one-half the diameter of the reel. At the very high speeds utilized by the instant cutter the cutting action takes place very quickly, and fiber fusing can result unless the impact forces can be reduced. The function of the larger diameter of pressure roller 20 is to provide a more gradual cutting action as the convergence between the periphery of pressure roller 20 and the locus of the cutting edges of the cutting blades 44 becomes more gradual as the pressure roller diameter increases.
In operation the device is controlled from a control panel 70 mounted onto cabinet 11 which encloses all of the hereinabove described mechanical linkages. Cutter reel assembly 18 is rotated due to the mechanical action of drive motor 12, timing belt 14 and drive shaft 16. To initiate operation, the cutter reel assembly 18 is brought up to the desired rotational speed as fan 32 induces a subatmospheric pressure inwardly of the blades 44 of reel assembly 18. This subatmospheric pressure inwardly of the blades 44 induces an airflow through tow inlet housing 36 which air flow is utilized to introduce the free end of a tow into the reel assembly proximal the arcuate terminus 64 of tow inlet housing 36. The subatmospheric pressure in conjunction with the rotating cutter blades entrain the tow so as to wrap the tow about the reel assembly 18 thereby drawing the tow over guide wheel 35, past tow guide 34, and through tow inlet housing 36. The tow is wrapped around reel assembly 18 to a sufficient depth as to engage pressure roller 20 which forces the wrapped tow inward, cutting the innermost tow at the locus of the periphery of pressure roller 20 and cutter blades 44. The cut tow or staple then flows inward of reel assembly 18 over the beveled blade support surfaces 56 to the conical surface 52 of axially extending lip 50 whereby said cut staple is discharged into discharge hopper 28. Air currents entering via the labyrinth seal between outer ring 40 and discharge hopper 28 lift the cut staple from the conical surface 52 and assist in directing such cut staple into the air pathway from ring 40 through discharge hopper 28 into lower discharge section 30 under the influence of the air currents set up therein by the action of fan 32. Discharge section 30 transports the cut staple to a suitable location for the next step in the processing of the fibers into a finished textile, said next step in the process being outside the scope of the present invention. To introduce a second tow to the cutter reel assembly 18 the second tow is discharged into inlet 60 of tow inlet housing 36 so as to be mechanically entrained by the first tow about cutter reel assembly 18 and is thereby positively drawn onto reel assembly 18.
The foregoing description has presented an embodiment of an improved tow cutter which reduces the centrifugal loading on both the tow cutter reel assembly and the uncut tow thereon by reducing the distance within the reel that the cut tow is required to transverse, and by reducing the accumulation of cut staple within the reel assembly through the use of advantageously beveled blade support posts and an outer ring having an inner diameter only slightly smaller than the diameter of the cutting edges of the cutting blades. The ring 40 also has a conical shaped outer lip which effectuates the transfer of cut staple from the reel assembly into a discharge hopper. Further, the hereinabove tow cutter provides an improvement in introducing tow into the tow cutter such that the tow cutter may be threaded up "on the fly" at initial start-up due to the advantageous utilization of subatmospheric pressure within the reel assembly or may be automatically threaded during operation by a second tow mechanically entrained to a first tow previously wrapped about reel assembly 18. The invention also improves the cutting action of previously known tow cutters by providing for a more gradual cutting action at high operating speeds thereby reducing fiber fusing which results from high impact forces between the pressure roller and the cutter blades.
While we have shown our invention in but one form, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various changes and modifications without departing from the spirit thereof.
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An outside-in tow cutter having a horizontal axis of rotation for its cutter reel assembly which includes an inner plate and an outer ring carrying radially disposed cutter blades, the outer ring having an inner diameter slightly smaller than the diameter of the circle formed by the cutting edges of the blades. The outer ring also carries an annular lip which cooperates with a snug fitting discharge hooper so that a subatmospheric pressure may be induced within said reel and said discharge housing to facilitate the removal of cut tow therefrom and to provide for pneumatically drawing the uncut tow onto the cutter reel assembly via an inlet housing.
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BACKGROUND OF THE INVENTION
1. Field Of The Invention
This invention relates to memory array circuitry and, more particularly, to decoding circuitry which may be used with three levels of voltages to provide accelerated row decoding.
2. History Of The Prior Art
There are a number of types of non-volatile memory arrays utilized to store digital information. Erasable read only memory (EPROM) and extensions of EPROM such as flash EPROM are used for many purposes. In general, such arrays are comprised of many transistors arranged in rows and columns with selection circuitry for determining the particular transistors to access. There has been a general tendency for such arrays (as for all memory arrays) to grow larger by including more and more memory transistors. As the number of transistors in a memory array connected to any selection line (such as a wordline or bitline) increases so does the capacitance affecting the line. This has the general tendency of slowing the rate at which switching can be accomplished.
The typical circuitry for accomplishing wordline decoding in an EPROM or a flash EPROM memory array utilizes a NAND gate as a predecoder circuit. This predecoder circuit is used to select a number of wordlines from a total of all wordlines, and then the individual wordline is selected from that first number of wordlines by one of a plurality of row decoder transistors connected in common to the output of the NAND gate.
In a non-volatile memory array, typically two separate voltage supplies are provided. One voltage supply, Vcc, is typically five volts and is used for reading the contents of the memory array. A second voltage supply, Vpp, is typically twelve volts and is used for programming and erasing the contents of the memory array. The row decoding circuitry must be designed to allow the transfer of both of these voltage levels onto the wordline. Typically, an internal voltage supply node exists which can be switched between the two external voltage supply values. This internal voltage supply node is connected to the row decoding circuitry to supply one or the other of the supply voltages.
The typical NAND gate used as a predecoder in these non-volatile arrays is made of one or more N channel field effect transistors (FETs) with their drain and source terminals connected in series between ground and an output terminal and a P channel field effect transistor with its source and drain terminals connected between a source of voltage (typically the internal voltage supply node) and the output terminal. The P channel device is a weak device which is biased "on." Selection signals are applied to the gates of the N channel devices. When high valued inputs equal to Vcc, which is typically five volts, are placed on the gates of the N channel devices, a low value is transferred to the NAND gate output. When any other signals are placed on the gates of the N channel devices, the P channel device furnishes a high value (equal to the internal voltage supply value, which is typically either five volts or twelve volts) to the output of the NAND gate. The output of the NAND gate is connected to the input of an inverter joined between the internal voltage supply and ground whose output drives the wordline of the array. The type of NAND gate described is referred to as a ratioed NAND gate.
One reason a ratioed NAND gate is used in the decoding circuitry associated with the wordlines of EPROM and similar arrays is that these arrays operate with both the normal source voltage (five volts) and with the higher source voltage (twelve volts) used to program the array. The typical full CMOS NAND gate having a pair of N channel devices joined in series between ground and an output node and a pair of P channel devices connected in parallel to the source voltage and the output node would not function correctly when the higher source voltage appears as the source voltage unless the CMOS NAND gate includes additional more complex circuitry which is not optimum for high speed decoding. For this reason, the ratioed arrangement using a weak P channel device which is capable of operating with all of the voltages to be expected is used.
However, because the current to the common node to which the row decoders are connected is furnished through a weak P device in a ratioed NAND gate, a relatively small current is available to accomplish the charging of the parasitic capacitance at the common node to which the row decoders are joined. Consequently, the time for deselection at a wordline is longer than is desirable. Slow deselection of the wordline slows down the transition to a newly selected wordline because the previously selected wordline remains selected for a longer period of time. On the other hand, with the increase in the number of memory transistor devices in the arrays, accelerated switching is necessary to overcome wordline delay and provide correct operation of the arrays.
In addition, it is necessary to optimize the voltage level at the point in time when a wordline being selected crosses a wordline being deselected in order to maintain optimum operation of the sense amplifier. If wordline deselection is too slow, this voltage level will be high, and two memory cells will be simultaneously selected. This, in addition to slowing down the access time, will not maintain optimum operation of the sense amplifiers.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to increase the speed with which wordlines are deselected and to provide increased control over wordline deselection in EPROM and similar memory arrays.
It is another object of the present invention provide voltage isolation in circuitry designed to increase the speed with which wordlines are deselected in EPROM and similar memory arrays which require two or more high voltage levels to be transferred to the wordline.
It is another, more specific, object of the present invention provide apparatus for allowing the rapid selection and deselection of the wordlines of EPROM and similar memory arrays which require two or more high voltage levels to be transferred to the wordlines.
These and other objects of the present invention are realized in a memory array in which logic signals of first and second voltage levels are used for selecting memory positions in the array for read operations and at least one signal of a voltage level higher than the first and second voltage levels may appear, and including a plurality of wordlines each joined to a common node by individual row decoders, a predecoder circuit for selecting a plurality of wordlines from which a row decoder may select an individual wordline comprising a full CMOS NAND gate arranged to provide output voltage levels of the first and the second voltage levels, a plurality of weak P channel devices each connected to one of the wordlines, means for operating the weak P channel devices to provide voltage levels of the higher level and below at the wordlines, means for limiting value of voltage transferred to the common point to be less than the higher voltage level, and means for limiting the level of the voltage transferred to the common node from the NAND gate to be less than a predetermined level.
These and other objects and features of the invention will be better understood by reference to the detailed description which follows taken together with the drawings in which like elements are referred to by like designations throughout the several views.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a circuit diagram illustrating a prior art arrangement for selecting a particular wordline in other than tri-level memory circuitry.
FIG. 2 is a circuit diagram illustrating another prior art arrangement for selecting a particular wordline.
FIG. 3 is a circuit diagram of an arrangement for selecting a particular wordline in accordance with the present invention.
FIG. 4 is another circuit diagram of a portion of the selection circuitry of an EPROM memory array in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to FIG. 1, there is illustrated a full CMOS NAND gate 10 which is typically used as a predecoder portion of a memory array selection circuit utilized for selecting a block of wordlines from which one of a plurality is selected. The NAND gate 10 includes a pair of N channel field effect transistor devices 12 and 13 and a pair of P channel field effect transistor devices 15 and 16. Each of the N channel devices 12 and 13 has its source and drain terminals connected in series with the source and drain terminals of the other device between ground and an output terminal. Each of the P channel devices 15 and 16 has its source and drain terminals connected between a source voltage Vcc (five volts) and the output terminal. The gates of the devices 12 and 15 are connected together to one input terminal and the gates of the devices 13 and 16 are connected together to a second input terminal. The output of the NAND gate is connected to an inverter whose output is the predecoder input to the row decoder. Typically the values applied to the input terminals of a full CMOS NAND gate are the source voltage (typically five volts) and ground. If ground is applied to both input terminals, the two P devices 15 and 16 are on, the two N devices 12 and 13 are off, and a high voltage close to the source voltage (Vcc) appears at the output terminal. This level is inverted so the predecoder output is at zero volts. If the source voltage (Vcc) is applied to both input terminals, the two N devices 12 and 13 are on, the two P devices 15 and 16 are off, and a low voltage close to ground appears at the output terminal of the NAND gate. This level is inverted so the predecoder output is at a voltage very close to the source voltage (Vcc). If the voltages at the input terminals differ, one of the P devices is on; and one of the N devices is on. No path exist from ground so a high value appears at the output terminal of the NAND gate, and a low value appears at the predecoder output.
The typical full CMOS NAND gate works well in memory array circuits in which only two voltages, ground and the source voltage, are used. However, as pointed out above, EPROM and similar memory circuit arrays such as flash EPROM utilize an additional higher level voltage (twelve volts) as a programming voltage. In the typical arrangement for selecting wordlines in an EPROM memory array, this higher level voltage would appear at the common node to which the output terminal of the NAND gate 10 is connected if a CMOS NAND gate were used for wordline selection. These P channel devices are MOSFETs which typically have the body of the transistor connected to the source voltage so that a p-n junction diode is formed between the output terminal of the nand gate and the body of the P devices. The effect of this voltage is to forward bias the p-n junction of the P channel devices 15 and 16 causing those devices to malfunction. Consequently, the NAND gate 10 described has not been utilized in EPROM and similar memory arrays using three levels of voltages.
Instead, a ratioed NAND gate circuit 20 (illustrated in FIG. 2) is typically utilized to provide the selection input for EPROM and similar memory array circuitry utilizing three voltage levels. As may be seen, rather than including a full CMOS NAND gate with two P channel devices and two N channel devices as illustrated in FIG. 1, the circuit 20 utilizes a single P channel device 21 between the source and the ratioed NAND gate output terminal. A pair of N channel devices 23 and 24 are connected in series between ground and the output terminal and receive the input signals at their gate terminals. The P channel device 21 is a weak device which provides minimal current contrasted to the current furnished by the N channel devices 23 and 24. This is necessary so that, when the gates of the N channel devices are at five volts (Vcc), they can pull down the output terminal of the ratioed NAND gate. The gate of this device 21 is biased by a bias circuit 26 which receives the source voltage Vpx as an input. The source voltage is designated as Vpx to indicate that it may vary from the high level programming value of twelve volts down to any source voltage value above ground. The bias circuit 26 is a switch which applies a voltage to the gate of the device 21 so that the device 21 is always on and always conducts weakly. If the voltage Vpx varies from five volts to twelve volts, the device 21 still remains on in the weak condition. Thus, this device is able to function with varying source voltages to furnish the values necessary for both read operations and during programming.
If the input signals to the gate terminals of the devices 23 and 24 are both high (five volts), these devices provide a substantial current path so that the output node is pulled to approximately ground. If on the other hand, one or both of the input signals is low, the path to ground is closed; and the weak device 21 acts as a pull up device to place the output at approximately Vpx (typically five volts in the read condition of the array). However, since both the biasing level and the source voltage of the circuit 20 vary together, the device 21 remains on and will function as a weak device whether Vpx is five volts (used during read operations), twelve volts (used in programming), or some other value between ground and twelve volts.
However, it has been found in use that the circuit 20 which relies on a weak P device to provide current for charging the parasitic capacitance of the common node connected to the plurality of row selection transistors is too slow in operation. Insufficient current can be furnished by the weak P devices to charge or discharge the line capacitance rapidly enough for the desired circuit specifications. Consequently, the row selection and deselection times must be extended, slowing the operation of the array. Even when the row selection and deselection times are extended, however, two word lines will be selected at the same time leading to non-optimum operation during a significant percentage of time. Memory cells in two individual rows will be providing output signals during the transition period in which a new row is being selected and an old row is being deselected. This causes the signals provided to the array sense amplifiers to be different than expected.
The circuit 30 illustrated in FIGS. 3 and 4 overcomes the problems of each of the prior art circuits illustrated above in FIGS. 1 and 2. FIG. 3 illustrates the circuit 30 in isolation while FIG. 4 shows a portion of a memory array in which the circuit 30 is utilized. This circuit 30 utilizes a full CMOS NAND gate 33 as a predecoder circuit. The NAND gate 33 includes a pair of N channel field effect transistor devices 31 and 32 connected in series between ground and an output terminal and a pair of P channel field effect transistor devices 34 and 35 each connected between a source of voltage Vcc and the output terminal. The gate terminals of the devices 31 and 35 are connected together to receive the same input signal, and the gate terminals of the devices 32 and 34 are connected together to receive a second input signal. When both input signals are high, the two devices 31 and 32 both conduct; and a low voltage is furnished at the output terminal. For any other combination of input signals, at least one of the P devices 34 or 35 is on providing a high value close to Vcc at the output terminal.
The output terminal of the NAND gate 33 connects to the common node through an N channel field effect transistor device 37. A capacitor 38 is shown to illustrate the effect of the parasitic capacitance which must be overcome in switching between wordlines. An N channel field effect transistor device 39 is arranged as a row decoder between the common node and an output driver 40 for any particular wordline. Also connected to the input to the output driver 40 is a P channel field effect transistor 42. The P channel device 42 is weak device which is biased on so that it furnishes Vpx at the input to the output driver when the row decoder device 39 for that particular row is disabled. To accomplish this, the value at the gate terminal if the array is being read is ground and the value of Vpx is five volts. If the array is being programmed, the gate terminal receives a voltage equal to Vpx minus twice the threshold value (Vtp) of the device 42 so that approximately twelve volts appears at the input to the driver 40.
In order to assure that the twelve volts furnished by the device 42 is not transferred back to the output of the NAND gate 33 to forward bias the p-n junctions of the devices 34 and 35 and cause the circuit to malfunction, the row decoder device 39 is driven to the on condition by Vcc (five volts) at its gate terminal. This limits the value of voltage which may be transferred to the common node to Vcc minus the threshold voltage Vt of the device 39 or somewhat less than five volts.
By utilizing the source voltage Vcc as the driving voltage for device 39, the twelve volts furnished by the device 42 cannot be transferred back to the output of the NAND gate 33 to forward bias the p-n junctions of the devices 34 and 3 and cause the circuit to malfunction. This allows the full CMOS NAND gate 33 to be utilized for the predecode selection in the array. The full CMOS NAND gate 33 provides a pair of P channel devices 34 and 35 each of which functions as a switch to furnish current from the source voltage Vcc for charging the common node capacitance. These devices 34 and 35 are typical strong P devices able to transfer substantial amounts of current in contrast to the weak P channel device used for charging the common node capacitance in ratioed NAND gate arrangements of the prior art. Consequently, the improved predecoder selection circuitry allows deselection of the word lines to occur much faster than with the prior art arrangements.
In addition to the elimination of the potential for forward biasing the P devices 34 and 35 of the NAND gate 33 in the condition in which Vpx is twelve volts, the device 37 is placed in the path between the output of the NAND gate 33 and the common node in order to eliminate the possibility of the p-n junction of the device 42 being forward biased in the condition in which Vpx is at a low value (lower than Vcc minus Vtn, where Vtn is the threshold voltage of device 39). If, for example, Vpx is three volts and one of the devices 34 or 35 is enabled, a voltage of approximately five volts appears at the output of the NAND gate 33. Without the device 37, this five volts (minus Vtn) would be applied at the input terminal of the driver 40. With the source voltage Vpx at three volts, this would forward bias the p-n junction of the device 42 and cause it to malfunction.
However, the device 37 is enabled with the value Vpx at its gate terminal. Consequently, the voltage which can be transferred to the common node from the output of the NAND gate 33 is Vpx less the threshold voltage Vt drop of the device 37. thus guaranteeing that the p-n junction of device 42 will not forward bias.
Although the present invention has been described in terms of a preferred embodiment, it will be appreciated that various modifications and alterations might be made by those skilled in the art without departing from the spirit and scope of the invention. The invention should therefore be measured in terms of the claims which follow.
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In a memory array in which logic signals of a first and a second voltage levels are used for selecting memory positions in the array for read operations and at least one signal of a voltage level higher than the first and second voltage levels may appear, and including a plurality of wordlines each joined to a common node by individual row decoders, a predecoder circuit for selecting a plurality of wordlines from which a row decoder may select an individual wordline including a full CMOS NAND gate arranged to provide output voltage levels of the first and a second voltage levels, a plurality of weak P channel devices each connected to one of the wordlines, means for operating the weak P channel devices to provide voltage levels of the higher level and below at the wordlines, means for limiting value of voltage transferred to the common point to be less than the higher voltage level, and means for limiting the level of the voltage transferred to the common node from the NAND gate to be less than a predetermined level.
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TECHNICAL FIELD
[0001] The present disclosure relates to mobile terminal field, and more particularly to a quick charging method and a quick charging system.
BACKGROUND
[0002] As the time progresses, the Internet and the mobile communication network have provided huge amounts of function applications. The users can not only use the traditional applications on the mobile terminals, for example, answering or making calls with smart phones; at the same time, the users can also browse the web pages, transmit pictures, play games and the like on the mobile terminals.
[0003] Along with the more frequent using of the mobile terminals, these mobile terminals need to be charged frequently. In addition, along with the users' requirement on the charging speed, some mobile terminals can accept the large current charging without monitoring the charging current. Meanwhile, some charging adaptors have been developed, via which constant charging with larger current can be performed. Although the charging time is reduced to some extent, the constant charging with larger current is easy to cause safety risk, for example, the cell can be overcharged if the charging adaptor still performs the large current charging when the cell is about to be fully charged or the electric quantity of the cell is comparatively sufficient before being charged by the charging adaptor.
DISCLOSURE
Technical Problem
[0004] An objective of the present disclosure is to provide a quick charging method and a charging device, so as to solve the problem in the related art that it is easy to overcharge the cell since the charging adapter forcibly charges the cell of the mobile terminal with constant, single and large charging current, without controlling the large current charging for the cell and without controlling the charging current.
Technical Solutions
[0005] In one aspect, the quick charging method provided by the disclosure can be applied to a charging system having a charging adaptor and a mobile terminal, and the quick charging method includes:
[0006] with a second controller, sending a quick charging request to a first controller, in which the charging adaptor includes the second controller, and the mobile terminal includes the first controller;
[0007] with the first controller, responding to the quick charging request of the second controller, and feeding back a quick charging permission command to the second controller;
[0008] with the second controller, sending a notification request for obtaining a voltage value of the cell to the first controller, in which the mobile terminal includes the cell;
[0009] with the first controller, responding to the notification request, obtaining the voltage value of the cell via a cell connector, and sending the voltage value of the cell obtained to the second controller, in which the mobile terminal includes the cell connector;
[0010] with the second controller, searching a threshold range table for a current regulation command matched with a threshold range containing the voltage value of the cell, and sending the current regulation command to a regulation circuit, in which the charging adaptor includes the regulation circuit, and the threshold range table records one or more threshold ranges and current regulation commands having a mapping relation with the one or more threshold ranges;
[0011] with the regulation circuit, performing a current regulation according to the current regulation command, and outputting a power signal after the current regulation.
[0012] In another aspect, the quick charging system provided by the present disclosure includes a charging adaptor including a second controller and a regulation circuit, and a mobile terminal including a cell connector, a first controller and a cell.
[0013] The second controller is configured to send a quick charging request to the first controller, and further configured to send a notification request for obtaining a voltage value of the cell to the first controller, and further configured to search a threshold range table for a current regulation command matched with a threshold range containing the voltage value of the cell, and to send the current regulation command to a regulation circuit. The charging adaptor includes the regulation circuit, and the threshold range table records one or more threshold ranges and current regulation commands having a mapping relation with the one or more threshold ranges.
[0014] The first controller is configured to respond to the quick charging request of the second controller, and to feed back a quick charging permission command to the second controller, and further configured to respond to the notification request, to obtain the voltage value of the cell via the cell connector, and to send the voltage value of the cell obtained to the second controller.
[0015] The regulation circuit is configured to perform a current regulation according to the current regulation command, and to output a power signal after the current regulation.
Beneficial Effects
[0016] The beneficial effects of the present disclosure is in that, when the charging adaptor can support quick charging, the second controller of the charging adaptor sends the quick charging request to the first controller of the mobile terminal for asking the mobile terminal whether the quick charging can be accepted. If the mobile terminal accepts the quick charging, a quick charging permission command will be fed back to the second controller, and then the charging adaptor performs quick charging on the cell of the mobile terminal. At the same time, the first controller will request the second controller for the voltage value of the cell, and generate a current regulation command according to the voltage value of the cell and the threshold range table, so as to control the regulation circuit to perform the current regulation, such that the regulate circuit outputs the power signal having the current value specified by the current regulation command. The charging adaptor outputs the power signal to charge the cell. In such a way, before performing quick charging to the cell of the mobile terminal, the charging adaptor will inquire the mobile terminal whether accepting quick charging, and control the charging current during the process of charging the cell, thus effectively preventing the cell from being overcharged.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] In order to illustrate the technical solutions in embodiments of the disclosure more clearly, a brief introduction of drawings needed in the description of embodiments of the disclosure or the related art is provided below. Apparently, the drawings in the following description are only some embodiments of the disclosure, and other drawings can be obtained based on these drawings by those skilled in the art without making creative efforts.
[0018] FIG. 1 is a first flow chart of a quick charging method provided by an embodiment of the present disclosure.
[0019] FIG. 2 is a specific flow chart of step S 6 in the quick charging method provided by an embodiment of the present disclosure.
[0020] FIG. 3 is a third flow chart of a quick charging method provided by an embodiment of the present disclosure.
[0021] FIG. 4 is a first block diagram of a quick charging system provided by an embodiment of the present disclosure.
[0022] FIG. 5 is a second block diagram of a quick charging system provided by an embodiment of the present disclosure.
[0023] FIG. 6 is a third block diagram of a quick charging system provided by an embodiment of the present disclosure.
[0024] FIG. 7 is a fourth block diagram of a quick charging system provided by an embodiment of the present disclosure.
DETAILED DESCRIPTION
[0025] In order to make the objective, the technical solutions and the advantages of the disclosure more clear, the disclosure is further described in details below in combination with the drawings and the embodiments. It is to be understood that the embodiments described herein are only used to explain the disclosure, but not used to limit the scope of disclosure. In order to illustrate the technical solutions described in the disclosure, the embodiments are used to illustrate as follows.
[0026] In embodiments of the present disclosure, the “first” in “first charging interface”, “first power wire”, “first ground wire” and “first controller” is a substitutive reference. The “second” in “second charging interface”, “second power wire”, “second ground wire” and “second controller” is also a substitutive reference.
[0027] It should be noted that the charging adaptor in embodiments of the disclosure includes a power adaptor, a charger, a terminal, such as an IPAD, a smart phone and any other device that is able to output a power signal to charge a cell (the cell of the mobile terminal).
[0028] In embodiments of the disclosure, when the charging adaptor charges the cell of the mobile terminal, by applying a second controller into the charging adaptor and by applying a first controller into the mobile terminal, and based on the communication between the first controller and the second controller, whether there is a need to use the charging adaptor to perform quick charging is confirmed (for example, the second controller inquires the first controller whether there is a need to perform quick charging to the cell of the mobile terminal), and the charging current is regulated during the whole process of charging, which effectively prevents the cell from being overcharged and ensures the quick charging to be performed safely.
[0029] FIG. 1 shows a first specific process of a quick charging method provided by an embodiment of the present disclosure. For ease of illustration, only parts related to embodiments of the present disclosure are shown, which are described in detail as follows.
[0030] The quick charging method provided by embodiment of the disclosure is applied to a charging system including the charging adaptor and the mobile terminal. The quick charging method includes following steps.
[0031] In step S 1 , a second controller sends a quick charging request to a first controller, in which the charging adaptor includes the second controller, and the mobile terminal includes the first controller.
[0032] In step S 2 , the first controller responds to the quick charging request of the second controller, and feeds back a quick charging permission command to the second controller.
[0033] In step S 3 , the second controller sends a notification request for obtaining a voltage value of the cell to the first controller, in which the mobile terminal includes the cell.
[0034] In step S 4 , the first controller responds to the notification request, obtains the voltage value of the cell via a cell connector, and sends the obtained voltage value of the cell to the second controller, in which the mobile terminal includes the cell connector.
[0035] In step S 5 , the second controller searches a threshold range table for a current regulation command matched with a threshold range containing the voltage value of the cell, and sends the current regulation command to a regulation circuit, in which the charging adaptor includes the regulation circuit, and the threshold range table records one or more threshold ranges and current regulation commands having a mapping relation with the threshold ranges.
[0036] In step S 6 , the regulation circuit performs a current regulation according to the current regulation command, and outputs a power signal after the current regulation.
[0037] Particularly, in this embodiment, if the charging adaptor used to charge the cell of the mobile terminal is a conventional charging adaptor, the conventional charging adaptor does not have the second controller, and thus cannot send the quick charging request to the first controller for inquiring whether there is a need to perform quick charging. Therefore, when the second controller is applied to the charging adaptor provided by embodiments of the present disclosure and the first controller is applied to the mobile terminal, the whole process of charging can be monitored via the communication between the first controller and the second controller.
[0038] If the charging adaptor has the ability of outputting large current, the communication between the first controller and the second controller is carried out by the steps S 1 and S 2 . Particularly, the second controller sends the quick charging request to the first controller, and inquires the first controller via the quick charging request whether charging the cell of the mobile terminal with large current can be accepted. If charging the cell of the mobile terminal with large current can be accepted, the first controller will feed back the quick charging permission command to the second controller, and then the second controller will determine that charging the cell of the mobile terminal with high current is accepted when it receives the quick charging permission command.
[0039] Further, the second controller sends the notification request to the first controller, and inquires the first controller about the voltage value of the cell with this notification request. During the whole process of charging, the cell connector coupled to the cell will detect and obtain the voltage value of the cell in real time, and send the obtained voltage value of the cell to the first controller in real time. Once the first controller receives the notification request, it responds to this notification request, and sends the obtained voltage value of the cell to the second controller.
[0040] It should be noted that in most cases, it is possible to choose electronic components capable of supporting large current (charging current equal to or greater than 3 A) and/or charging circuits capable of supporting large current (including the charging circuit of the charging adaptor such as a rectifier and filter circuit and a voltage and current regulation circuit, and the charging circuit of the mobile terminal). However, when the cell of the mobile terminal is charged using a constant large current, since impedances such as internal resistance, parasitic resistance and coupling resistance may be introduced into the charging circuits (including the charging circuit in the mobile terminal and the charging circuit in the charging adaptor), more heat dissipation (a large amount of heat) may be generated during the process of charging.
[0041] Thus, in this embodiment, when the first charging interface of the mobile terminal is insertion-connected with the second charging interface of the charging adaptor, the charging adaptor can charge the cell of the mobile terminal with large current after steps S 1 and S 2 . In order to reduce charging time and to reduce heat dissipation generated during the charging process, and further in order to prevent the cell from being overcharged, the second controller regulates the current value of the outputted power signal (i.e., regulates the current value of the power signal flowing into the cell) according to the voltage value of the cell obtained in real time and according to the threshold range table.
[0042] It is to be understood that there is a threshold range table stored in the second controller, and this threshold range table can be preset according to the control demands corresponding to the charging time and the charging current required for charging the cell. Preferably, the threshold range table is downloaded to the second controller after being edited by a terminal which has an edit capability.
[0043] Furthermore, this threshold range table records one or more threshold ranges, each of which has a voltage upper limit and a voltage lower limit. Meanwhile, the threshold range table also records one or more current regulation commands. Each current regulation command has one corresponding threshold range. In a specific embodiment of the present disclosure, when the detected voltage value of the cell is within the interval range from 0 V to 4.3 V, the charging adaptor outputs a 4 A power signal to charge the cell; when the detected voltage value of the cell is within the interval range from 4.3 V to 4.32 V, the charging adaptor outputs a 3 A power signal to charge the cell; when the detected voltage value of the cell is within the interval range from 4.32 V to 4.35 V, the charging adaptor outputs a 2 A power signal to charge the cell; and when the detected voltage value of the cell is above 4.35 V, the charging adaptor only outputs a power signal of hundreds milliampere (mA) to charge the cell. In such a way, by detecting the voltage of the cell in real time, the charging adaptor outputs large current (charging current equal to or greater than 3 A) to the cell for charging the cell with large current when the voltage of the cell is lower, and further outputs a low current to the cell for charging the cell with low current (charging current of hundreds milliampere) when the detected voltage of the cell reaches the switch-off voltage threshold which means the cell is about to be fully charged. This can not only prevent the cell from being overcharged, but also reduce the charging time. Preferably, the voltage threshold range composed of all the threshold ranges recorded in this threshold range table is numerically continuous. In such a way, it can ensure that a corresponding current regulation command can be found with respect to each detected voltage value of the cell (the voltage value of the cell).
[0044] Further, if the voltage value of the cell received continuously changes from one threshold range to another threshold range, the second controller will send a current regulation command matched with the other threshold range to the regulation circuit.
[0045] When receiving the current regulation command, the regulation circuit regulates the power signal output from the charging adaptor, in which the current value of the power signal output from the regulation circuit is equal to the current value specified by the current regulation command.
[0046] In another embodiment of the present disclosure, impedances such as internal resistance, parasitic resistance and coupling resistance, may be introduced into the charging circuits (including the charging circuit in the mobile terminal and the charging circuit in the charging adaptor), and the introduced impedances will consume a portion of the current, which causes this portion of current will not flow into the cell of the mobile terminal, therefore, in order to ensure that the current directly flowing into the cell can reach the preset current value, it is necessary to consider the portion of current consumed by the introduced impedances, and further the current value specified by the current regulation command will be greater than the current value of the power signal flowing into the cell. Preferably, the current value specified by the current regulation command is equal to a sum of the preset current value directly flowing into the cell and the current value of the portion of current consumed by the introduced impedances. For example, if the current value of the power signal expected to flow into the cell is 3.2 A and the current value of the portion of current consumed by the introduced impedances is 0.8 A, the current value specified by the current regulation command (i.e., the current value of the power signal outputted from the charging adaptor) should be set to 4 A.
[0047] FIG. 2 shows a specific process of step S 6 in the quick charging method provided by embodiments of the present disclosure, and for illustration, only parts related to the embodiments of the present disclosure is shown, which is described in detail as follows.
[0048] In another embodiment of the present disclosure, in order to ensure that the power signal output from the regulation circuit has a large current (has the current value specified by the current regulation command), it is necessary to detect whether the power signal output from the charging adaptor has the current value specified by the current regulation command in real time. Thus, the regulation circuit includes a current detection circuit.
[0049] At the same time, the regulation circuit performs the current regulation according to the current regulation command and outputs the power signal after the current regulation as follows.
[0050] In step S 61 , the current detection circuit detects the current value of the power signal output from the regulation circuit, and sends the detected current value to the second controller.
[0051] In step S 62 , the second controller calculates a difference between the detected current value and the current value specified by the current regulation command, and sends a calibration command to the regulation circuit if an absolute value of the calculated difference is greater than a difference threshold.
[0052] In step S 63 , the regulation circuit calibrates the power signal according to the current difference specified by the calibration command, and outputs a calibrated power signal, in which the current value of the calibrated power signal is equal to the current value specified by the current regulation command.
[0053] In this embodiment, the regulation circuit has the current detection circuit, which can detect the current value of the power signal output from the regulation circuit (i.e., the current value of the power signal output from the charging adaptor) in real time. Preferably, the current detection circuit has a current detection resistor, which detects the current value of the power signal output from the regulation circuit in real time and converts the current value to a voltage value, and sends the voltage value to the second controller, such that the second controller determines the current value of the power signal output from the regulation circuit according to the voltage value received and the resistance of the current detection resistor.
[0054] Then, the second controller calculates the difference between the detected current value and the current value specified by the current regulation command, calculates the absolute value of the difference, judges whether the absolute value is greater than the difference threshold, and feeds back the calibration command to the regulation circuit if the absolute value of the calculated difference is greater than the difference threshold, such that the regulation circuit regulates the current value of the power signal outputted therefrom in time according to the calibration command. It should be noted that, the difference threshold can be adjusted in advance according to actual working environment of the regulation circuit.
[0055] Then, if the regulation circuit receives the calibration command, it represents that the deviation of the current value of the power signal outputted by the regulation circuit from the current value specified by the current regulation command is higher, and it is necessary for the regulation circuit to perform the current regulation again. Particularly, the current regulation can be performed according to the current difference specified by the calibration command, thereby ensuring in real time that the current value of the power signal output from the regulation circuit is equal to the current value specified by the current regulation command.
[0056] In an example embodiment of the disclosure, the regulation circuit also includes a voltage and current regulation circuit. The voltage and current regulation circuit performs a rectifying and filtering on the mains supply to obtain an original power signal. In order to calibrate the power signal output from the regulation circuit according to the calibration command, during the process of performing voltage regulation on the voltage of the original power signal, the regulation circuit determines a voltage regulation command according to the current difference specified by the calibration command, and sends the voltage regulation command to the voltage and current regulation circuit. The voltage and current regulation circuit performs the voltage regulation according to the voltage regulation command and outputs the power signal after voltage regulation. Since the power signal after the voltage regulation flows through the current detection resistor, the current value of the power signal after voltage regulation can be re-detected with the current detection resistor for confirming whether the current value of the power signal is equal to the current value specified by the current regulation command. When the current value of the power signal flowing through the current detection resistor (the power signal after voltage regulation) is equal to the current value specified by the current regulation command, the regulation circuit stops determining the voltage regulation command according to the received calibration command and stops sending the determined voltage regulation command to the voltage and current regulation circuit, and the voltage and current regulation circuit stops performing the voltage regulation.
[0057] In this way, in order to ensure in real time that the current value of the power signal output from the regulation circuit is equal to the current value specified by the current regulation command, the current detection resistor is used to detect in real time, and when the detected current value is too high or too low, the detected current value is fed back to the second controller. The second controller generates the calibration command according to the current value fed back and sends the calibration command to the regulation circuit. The regulation circuit determines the voltage regulation command according to the calibration command and sends the voltage regulation command to the voltage and current regulation circuit. The voltage and current regulation circuit performs the voltage regulation according to the voltage regulation command, and outputs the power signal after the voltage regulation. Then, it is able to further detect with the current detection resistor whether the current value of the power signal after the voltage regulation is equal to the current value specified by the current regulation command.
[0058] FIG. 3 shows a second specific process of the quick charging method provided by embodiments of the present disclosure, and for illustration, only parts related to embodiments of the present disclosure is shown, which is described in detail as follows.
[0059] In another embodiment of the present disclosure, after the step that the regulation circuit performs the current regulation according to the current regulation command and outputs the power signal after the current regulation, the quick charging method also includes following steps.
[0060] In step S 7 , the charging adaptor sends the power signal via a second charging interface thereof to a first charging interface of the mobile terminal, so as to charge the cell of the mobile terminal, in which first power wires of the first charging interface are coupled to second power wires of the second charging interface, and first ground wires of the first charging interface are coupled to second ground wires of the second charging interface, there are P first power wires and Q first ground wires, where P is greater than or equal to 2, and Q is greater than or equal to 2.
[0061] Particularly, in this embodiment, the common MICRO USB interface (including the MICRO USB interface of the charging adaptor, and also including the MICRO USB interface of the mobile terminal) has only one power wire and one ground wire, so that it is only possible to form the charging circuit with the power wire and the ground wire, and in turn, the charging current is usually only hundreds milliampere, and usually not greater than 3 A.
[0062] For this, this embodiment provides the first charging interface that is capable of supporting charging with large current (charging current greater than or equal to 3 A). The first charging interface has at least two first power wires and at least two first ground wires, therefore, via the first charging interface, the mobile terminal can support charging with large current.
[0063] In addition, if the charging adaptor coupled to the first charging interface is a conventional charging adaptor such as a charging adaptor using the MICRO USB interface for charging, it is still possible to perform conventional charging (coupling the only power wire and ground wire of the MICRO USB interface to the one first power wire and one first ground wire of the first charging interface correspondingly), which means that only the power wire and ground wire are used to charge the cell.
[0064] Preferably, there are P second power wires and Q second ground wires.
[0065] The P first power wires in the first charging interface are correspondingly coupled to the P second power wires in the second charging interface, and the Q first ground wires in the first charging interface are correspondingly coupled to the Q second round wires in the second charging interface.
[0066] In this embodiment, when the first charging interface is insertion-connected with the second charging interface, at least two charging circuits can be formed (the number of the charging circuits is the minimum of P and Q). Further, the insertion-connected first charging interface and second charging interface can support charging with large current (charging current equal to or greater than 3 A). Thus, the charging adaptor can output the power signal of large current (for example, 4 A power signal) to charge the cell of the mobile terminal with large current, when the voltage value of the cell is lower (for example, the voltage value of the cell is less than 4.3V).
[0067] Preferably, both the power wire and the ground wire of the conventional MICRO USB interface are made of metal copper foil with the electric conductivity less than 20%. However, in the disclosure, the first power wires and the first ground wires of the first charging interface, and the second power wires and the second ground wires of the second charging interface are made of phosphor bronze C 7 025 with the electric conductivity up to 50%, so that in case of using at least two charging circuits (including at least two first power wires, at least two first ground wires, at least two second power wires and at least two second ground wires) to charge the cell of the mobile terminal, the charging current is further increased. More preferably, the first power wires and the first ground wires of the first charging interface, and the second power wires and the second ground wires of the second charging interface provided by embodiments of the present disclosure are made of chromium bronze C18400 with the electric conductivity up to 70%, so that the charging current is further increased.
[0068] In another embodiment of the present disclosure, the mobile terminal also includes a switch circuit, and the switch circuit is controlled by the first controller to switch on or off. In such a way, since a switch circuit is further applied into the mobile terminal having the charging circuit, when the second charging interface is coupled with the first charging interface, it is not only able to charge the cell via the charging circuit of the mobile terminal, but also able to control the switch circuit to switch on with the first controller and to charge the cell via the switched-on switch circuit.
[0069] Preferably, after the step that the first controller responds to the quick charging request of the second controller, the quick charging method also includes following steps.
[0070] The first controller sends a switch-on command to the switch circuit.
[0071] When the switch circuit receives the switch-on command, the switch circuit switches on the charging circuit by which the charging adaptor charges the cell via the switch circuit.
[0072] Particularly, when the first controller receives the quick charging request sent from the second controller, and the first controller detects that there is the switch circuit, the cell can be charged via the charging circuit already existing in the mobile terminal and also via the switch circuit, thus realizing charging the cell with large current.
[0073] Then, the first controller feeds back the quick charging permission command to the second controller, so as to inform the second controller that: the cell can be charged with large current. At the same time, the first controller also sends the switch-on command to the switch circuit.
[0074] The switch circuit, when receiving the switch-on command, is switched on, and further the charging adaptor can charge the cell via the switched on switch circuit while charging the cell of the mobile terminal via the charging circuit already existed in the mobile terminal.
[0075] Preferably, after the step that the first controller obtains the voltage value of the cell via the cell connector, the quick charging method also includes following steps.
[0076] The first controller determines whether the obtained voltage value of the cell is greater than the switch-off voltage threshold, and sends a switch-off command to the switch circuit if the obtained voltage value of the cell is greater than the switch-off voltage threshold.
[0077] When the switch circuit receives the switch-off command, the switch circuit switches off the charging circuit by which the charging adaptor charges the cell via the switch circuit.
[0078] Particularly, during the whole process of charging the cell, the cell connector will always detect and obtain the voltage value of the cell in real time, and send the detected voltage value of the cell to the first controller. When charging the cell via the switch circuit, the first controller judges in real time whether the obtained voltage value of the cell is greater than the switch-off voltage threshold, and sends the switch-off command to the switch circuit if the obtained voltage value of the cell is greater than the switch-off voltage threshold. The switch circuit is switched off when receiving the switch-off command. At this time, the charging adaptor can charge the cell of the mobile terminal only via the charging circuit already existed in the mobile terminal, rather than via the switch circuit which is switched off.
[0079] Preferably, when the obtained voltage value of the cell is greater than the switch-off voltage threshold, the second controller also sends the current regulation command to the regulation current, in which the current regulation command specifies the power signal of small current (for example, hundreds milliampere) outputted from the regulation circuit.
[0080] In an embodiment of the present disclosure, the first controller can be a controller existing in the mobile terminal.
[0081] In another embodiment of the present disclosure, the mobile terminal not only has a third controller (already configured in the existing mobile terminal) used to handle applications, but also has the first controller. The first controller controls the switch circuit and controls charging the cell of the mobile terminal.
[0082] Thus, the first controller transmits the voltage value of the cell received in real time to the third controller, and the third controller determines whether the obtained voltage value of the cell is greater than the switch-off voltage threshold. If the obtained voltage value of the cell is greater than the switch-off voltage threshold, the third controller sends a first switch-off command to the first controller, and then the first controller sends the switch-off command to the switch circuit. Preferably, the third controller can directly send the switch-off command to the switch circuit if the obtained voltage value of the cell is greater than the switch-off voltage threshold. The switch circuit switches off the charging circuit by which the charging adaptor charges the cell via the switch circuit, when receiving the switch-off command.
[0083] In addition, when the first charging interface of the mobile terminal is electrically coupled to the MICRO USB interface of a conventional charging adaptor, the charging can be performed via the charging circuit already existed in the mobile terminal. Based on the fact that the mobile terminal has already got the charging circuit, this embodiment additionally adds a switch circuit into the mobile terminal. Thus, when the second charging interface is insertion-connected with the first charging interface, it is not only able to charge the cell via the charging circuit in the mobile terminal, but also able to control the switch circuit to switch on with the first controller, such that the charging adaptor can charge the cell via the existing charging current and also via the switch circuit which is switched on.
[0084] The cell connector is also configured to generate an anode contact signal when detecting whether an anode of the cell is in contact, to generate a cathode contact signal when detecting whether a cathode of the cell is in contact, to generate a temperature signal when detecting a temperature of the cell, and to send the anode contact signal, the cathode contact signal and the temperature signal to the first controller. The first controller transmits the anode contact signal, the cathode contact signal and the temperature signal to the third controller.
[0085] Then, the third controller determines whether a positive charging contact point of the charging circuit and the switch circuit of the mobile terminal is in good contact with the anode of the cell according to the received anode contact signal, determines whether a negative charging contact point of the charging circuit and the switch circuit of the mobile terminal is in good contact with the cathode of the cell according to the received cathode contact signal, and determines whether the temperature of the cell exceeds a temperature threshold according to the temperature signal.
[0086] Then, the third controller is configured to send the first switch-off command to the first controller, if it is determined that the positive charging contact point is not in good contact with the anode of the cell according to the received anode contact signal, or if it is determined that the negative charging contact point is not in good contact with the cathode of the cell according to the cathode contact signal, or if it is determined that the temperature of the cell has exceeded the temperature threshold according to the temperature signal. Then, the first controller sends the switch-off command to the switch circuit to switch off the switch circuit, which stops the charging adaptor from charging the cell via the switch circuit.
[0087] FIG. 4 shows a first block diagram of a quick charging system provided by an embodiment of the present disclosure, and for illustration, only parts related to the embodiments of the present disclosure are shown, which is described in detail as follows.
[0088] It should be noted that, the quick charging system provided by embodiments of the present disclosure and the quick charging method provided by embodiments of the present disclosure are applicable to each other.
[0089] The quick charging system provided by embodiments of the present disclosure includes a charging adaptor 2 having a second controller 21 and a regulation circuit 22 , and a mobile terminal 1 having a cell connector, a first controller 11 and a cell.
[0090] The second controller 21 is configured to send a quick charging request to the first controller 11 , to send a notification request for obtaining a voltage value of the cell to the first controller 11 , to search a threshold range table for a current regulation command matched with a threshold range containing the voltage value of the cell, and to send the current regulation command to the regulation circuit 22 . The charging adaptor 2 includes the regulation circuit 22 , and the threshold range table records one or more threshold ranges and current regulation commands having a mapping relation with the threshold ranges.
[0091] The first controller 11 is configured to respond to the quick charging request of the second controller 21 , to feed back a quick charging permission command to the second controller 21 , to respond to the notification request, to obtain the voltage value of the cell via the cell connector, and to send the obtained voltage value of the cell to the second controller 21 .
[0092] The regulation circuit 22 is configured to perform the current regulation according to the current regulation command, and to output the power signal after the current regulation.
[0093] FIG. 5 shows a second block diagram of the quick charging system provided by an embodiment of the disclosure, and for illustration, only parts related to embodiments of the disclosure are shown, which is described in detail as follows.
[0094] In another embodiment of the disclosure, the regulation circuit 22 includes a current detection circuit 221 .
[0095] The current detection circuit 221 is configured to detect a current value of the power signal output from the regulation circuit 22 , and to send the detected current value to the second controller 21 .
[0096] The second controller 21 is also configured to calculate a difference between the detected current value and the current value specified by the current regulation command, and to send a calibration command to the regulation circuit 22 if an absolute value of the calculated difference is greater than a difference threshold.
[0097] The regulation circuit 22 is also configured to calibrate the power signal according to the current difference specified by the calibration command, and to output the calibrated power signal, in which the current value of the calibrated power signal is equal to the current value specified by the current regulation command.
[0098] FIG. 6 shows a third block diagram of the quick charging system provided by an embodiment of the present disclosure, and for illustration, only parts related to embodiments of the present disclosure are shown, which is described in detail as follows.
[0099] In another embodiment of the present disclosure, the charging adaptor 2 further includes a second charging interface 23 , and the mobile terminal 1 further includes a first charging interface 12 .
[0100] The charging adaptor 2 is further configured to send the power signal via the second charging interface 23 to the first charging interface 12 , so as to charge the cell of the mobile terminal 1 . The first power wires of the first charging interface 12 are coupled to the second power wires of the second charging interface 23 , and the first ground wires of the first charging interface 12 are coupled to the second ground wires of the second charging interface 23 . The number of the first power wires is P and the number of the first ground wires is Q, where P is greater than or equal to 2, and Q is greater than or equal to 2.
[0101] In another embodiment of the present disclosure, the number of the second power wires is P and the number of the second ground wires is Q.
[0102] The P first power wires in the first charging interface 12 are correspondingly coupled to the P second power wires in the second charging interface 23 , and the Q first ground wires in the first charging interface 12 are correspondingly coupled to the Q second round wires in the second charging interface 23 .
[0103] FIG. 7 shows a fourth block diagram of the quick charging system provided by an embodiment of the present disclosure, and for illustration, only parts related to embodiments of the present disclosure are shown, which is described in detail as follows.
[0104] In another embodiment of the present disclosure, the mobile terminal 1 further includes a switch circuit 13 .
[0105] The first controller 11 is further configured to send a switch-on command to the switch circuit 13 , and further configured to determine whether the obtained voltage value of the cell is greater than a switch-off voltage threshold, and to send a switch-off command to the switch circuit 13 if the obtained voltage value of the cell is greater than the switch-off voltage threshold.
[0106] The switch circuit 13 is configured to switch on the charging circuit by which the charging adaptor 2 charges the cell via the switch circuit 13 when receiving the switch-on command, and further configured to switch off the charging circuit by which the charging adaptor 2 charges the cell via the switching circuit 13 , when receiving the switch-off command.
[0107] The forgoing description is only directed to preferred embodiments of the present disclosure, but not used to limit the present disclosure. For those skilled in the art which the present disclosure belongs to, all modifications, equivalents, variants and improvements made within the spirit and principle of the present disclosure shall fall within the protection scope of the present disclosure defined by appended claims.
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A quick-charging method and system suitable for the field of mobile terminals. The method comprises: (S 1 ) a second controller ( 21 ) sending a quick-charging request to a first controller ( 11 ); (S 2 ) the first controller feeding back a quick-charging permission command to the second controller; (S 3 ) the second controller sending a notification request for obtaining a voltage value of a cell to the first controller; (S 4 ) the first controller obtaining the voltage value of the cell by means of a cell connector, and sending the obtained voltage value of the cell to the second controller; (S 5 ) the second controller finding a current regulation instruction matching a threshold section that the voltage value of the cell falls within from a threshold section table, and sending a current regulation instruction to a regulation circuit ( 22 ); and (S 6 ) the regulation circuit adjusting a current according to the current regulation instruction, and outputting a power supply signal of which the current is regulated. In this manner, before a cell of a mobile terminal ( 1 ) is quickly charged, it is queried whether the mobile terminal accepts quick charging; and a charging current is controlled during charging, thereby effectively avoiding overcharging of the cell.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is the U.S. National Stage of International Application No. PCT/EP2004/008290, filed Jul. 23, 2004 and claims the benefit thereof. The International Application claims the benefits of European Patent application No. 03019868.3 filed Sep. 1, 2003, all of the applications are incorporated by reference herein in their entirety.
FIELD OF THE INVENTION
A method for identifying an operating state during operation of a turbine, and a device for identifying an operating state during operation of a turbine.
The invention relates to a method for identifying an operating state during operation of a turbine in accordance with the claims, and to a device for carrying out the method in accordance with the claims.
BACKGROUND OF THE INVENTION
It is known for the purpose of identifying an operating state of a turbine to detect and evaluate the temperatures prevailing in the exhaust gas continuously. Temperature measuring devices that detect the temperatures of the exhaust gas are arranged distributed for this purpose coaxially and uniformly on the inner wall of the exhaust gas housing. Extreme value comparisons are carried out in order to evaluate the measured exhaust gas temperatures. The maximum and minimum occurring temperatures are detected for each measuring point during trial operation, and a temperature interval is thereby determined. A disturbance is determined when the temperature measuring element detects a temperature that lies outside its previously measured temperature interval.
It is also known to determine the difference from the time-averaged temperature value of a temperature measuring device and the instantaneous temperature, in order to determine the operating state.
These evaluations have the disadvantage that small systematic variations in the exit temperatures that lie below the prescribed limits remain unconsidered.
It is known, furthermore, from US2002/183916 A1 to calculate the angle of rotation of the exit temperature field.
The determined angle of rotation is used to normalize the exit temperature field in order to enable temperature measuring points to be used to deduce dedicated Can combustion chambers.
Moreover, EP 1 118 920 A1 discloses vibration monitoring of rotating components. One or more vibration sensors arranged offset from one another are provided for this purpose. The recorded amplitudes and phase angles of the vibrations or of the temporary displacements caused by the vibrations are detected with the aid of these sensors and decomposed into two mutually perpendicular components that are subsequently converted with the formation in each case of a sliding arithmetic mean value to form a resulting variable with amplitude and phase angle, which variable is then evaluated for the purpose of analyzing state.
Again, a display for a turbine exit temperature field is known from JP 02-064232.
SUMMARY OF THE INVENTION
It is therefore the object of the present invention to specify a method for identifying an operating state during operation of a turbine and with the aid of which systematic variations in the operating state can be identified and displayed. It is also an object of the invention to specify a device corresponding thereto.
The object directed to the method is achieved by the features of claims. Advantageous developments are specified in the subclaims.
The invention adopts a new path for identifying an operating state during operation of a turbine. To date, spatial temperature measurements in which the exit temperature of the exhaust gas was detected have been performed in the exhaust gas duct at a number of positions. The spatial position of each detected temperature has previously remained unconsidered in this case. All the detected temperatures together with their respectively associated spatial position are now combined with one another with the formation of moments to form a resulting variable by means of which systematic variations can be identified more quickly and more accurately.
The exhaust gas temperatures of an instant are plotted in a coordinate system while taking account of the location at which they are detected. Thereafter, each measured temperature value is projected onto the two axes of the coordinate system and is therefore respectively decomposed into two spatial components perpendicular to one another in this case and respectively directed either positively or negatively, the identically directed spatial components subsequently being summed up for each axis component by component with reference to a respective reference value and with the formation of moments to form two moment sums, each reference value being selected such that the oppositely directed moment sums are equally large, and that thereafter a point composed from the two reference values is evaluated as centroid of the exit temperature distribution for the purpose of identifying the operating state of the gas turbine.
Information that has previously been below the minimal conditions is taken into account by the use of the overall information of the exit temperature distribution. Moreover, this yields a higher level of information content, which is used for the purpose of identifying states more quickly and more effectively.
In an advantageous refinement, the operating state is identified during a stationary operation of the gas turbine as a disturbance when the centroid can be represented as a vector having magnitude and angle, and when the current magnitude—orangle—of the centroid vector exhibits with reference to a magnitude—or angle—measured at an earlier instant a difference that overshoots or undershoots a tolerance value. Two centroids detected at different instants are compared with one another, their difference being monitored. If the difference overshoots a tolerance value, a disturbance of the operation of the turbine is identified. The tolerance values are determined by test operations or by empirical values.
From the opposite point of view, an undisturbed operation of the gas turbine can be diagnosed when the centroid vector remains constant in magnitude and/or angle when viewed over time.
The temporal behavior of the magnitude and the angle of the centroid vector—the centroid of the exit temperature distribution—exhibits a known response during operation of the turbine:
During undisturbed operation of the gas turbine, the centroid vector of the exit temperature distribution settles at a temporally constant magnitude with a constant angle. Here, constant means that although slight changes can occur within the fluctuation range prescribed by tolerance values, they are nevertheless not to be ascribed to systematic influences, but to random ones.
If load changes occur, these have no influence on the magnitude of the centroid vector, since the magnitude is fundamentally invariant with respect to load changes.
The angle of the centroid vector is fundamentally dependent on load changes, since these are likewise accompanied by changes in the hot gas mass flow and thus in the flow conditions within the turbine. The variation in the hot gas mass flow results from the adjustments of the compressor inlet guide vanes and/or from the variation in the fuel mass flow that is fed.
The variations in the hot gas mass flow cause a corresponding rotation of the exit temperature distribution. However, this is not synonymous with a disturbance, since this change in angle is to be ascribed to known interventions in the operation of the gas turbine.
If there is a substantial change in the magnitude or the angle of the centroid vector during stationary operation of the turbine, this is to be ascribed to a systematic variation such as, for example, blocking of the ducts by a loosened thermal shielding brick. The systematic variations are to be ascribed to defective operation or a disturbance of the gas turbine, since a known, external influence is lacking. Furthermore, combustion disturbances, which can be nozzle carbonization, on the one hand, or an altered flame alignment, on the other, lead to variation in the centroid of the exit temperature distribution. Likewise, flow fluctuations that are reflected in temperature fluctuations can lead to rotation of the angle.
A plane in which the measuring points for the temperature measuring devices lie is expediently aligned perpendicular to the principal flow direction of the exhaust gas, and the principal flow direction is parallel to the rotation axis of a shaft of the turbine. The temperatures are therefore tracked over time at an identical spacing from the rotation axis of the shaft.
In an advantageous development, the measuring points are arranged in a fashion rotationally symmetrical relative to the rotation axis. This results in an equidistant distribution that is particularly easy to evaluate because of the symmetry.
The method is suitable in general for continuously monitoring the operation. It is very particularly advantageous in this case when the method is preferably applied at every instant, that is to say continuously, during the stationary or quasi-stationary operation of the turbine, since the method delivers particularly reliable results here. The analysis of the state of the gas turbine operation with the aid of the centroid vector can, however, be carried out in principle even during a strongly transient operation—given suitable modifications—, there being a need to consider special features in transient operation. Reliable results and statements relating to the behavior of the gas turbine when traversing a transient operating state, for example starting operations and stopping operations, can consequently be investigated in detail.
The turbine is expediently designed as a gas turbine.
The object directed to the device is achieved by the features of claims. Advantageous developments are specified in the subclaims.
Each temperature measuring device is connected to an input of a single evaluation device with the aid of which an operating state can be characterized. The method described is then carried out in the evaluation device such that a signal for the operating state can therefore be displayed at the output of the evaluation device. Consequently, the evaluation device has means for recording the detected temperature and means for identifying the operating state.
In an advantageous development, a plane in which the temperature measuring devices are provided is transverse to the principal flow direction of the exhaust gas, which runs parallel to the rotation axis of a shaft of the turbine. The temperature measuring devices lying in the plane are provided at the inner wall of the exhaust gas housing such that all the spatial measured temperature values are detected at the same spacing from the rotation axis of the shaft. Identical conditions are therefore created for the temperature measuring devices; weighting of individual measuring points is not required.
The spatial measured temperature values can expediently be detected in a fashion rotationally symmetrical relative to the rotation axis.
When the turbine has an annular combustion chamber at which a number of burners are provided, and the number of burners is equal to the number of temperature measuring devices, it is possible to relate burners to the exhaust gas temperature measured in the exhaust gas duct.
If the turbine has a number of combustion chambers respectively having one burner, it is possible to relate burners to the exhaust gas temperature measured in the exhaust gas duct even over a number of temperature measuring devices when this number corresponds to the number of combustion chambers.
The turbine is advantageously designed as a gas turbine.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is explained in more detail with the aid of a drawing, in which:
FIG. 1 shows a gas turbine in a longitudinal partial section,
FIG. 2 shows a Cartesian coordinate system with a diagram of the exit temperature distribution,
FIG. 3 shows a combined magnitude/time and angle/time diagram for a centroid vector of the exit temperature distribution of the gas turbine, and
FIG. 4 shows an evaluation device for the monitoring method.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a gas turbine 1 in a longitudinal partial section. It has in the interior a rotor 3 that is mounted so as to rotate about a rotation axis 2 and is also denoted as turbine rotor or rotor shaft. Following one after the other along the rotor 3 are an inlet housing 4 , a compressor 5 , a toroidal annular combustion chamber 6 with a number of coaxially arranged burners 7 , a turbine 8 and an exhaust gas housing 9 .
Provided in the compressor 5 is an annular compressor duct 10 that tapers in cross section in the direction of the annular combustion chamber 6 . Arranged at the output, on the combustion chamber side, of the compressor 5 is a diffuser 11 that is connected to the annular combustion chamber 6 in terms of flow. The annular combustion chamber 6 forms a combustion space 12 for a mixture of a fuel and compressed air L. A hot gas duct 13 is connected to the combustion space 12 in terms of flow, the exhaust gas housing 9 being arranged downstream of the hot gas duct 13 .
Vane rows are arranged in a respectively alternating fashion in the compressor duct 10 and in the hot gas duct 13 . A guide vane row 15 formed from guide vanes 14 is respectively followed by a moving vane row 17 formed from moving vanes 16 . The stationary guide vanes 14 are connected in this case to the stator 18 , whereas the moving vanes 16 are fastened on the rotor 3 by means of a turbine disk 19 .
The exhaust gas duct 9 is delimited by an inner wall 24 that is concentric with the rotation axis 2 and on which twenty-four temperature measuring devices M i are arranged in a rotationally fixed fashion and distributed uniformly over the circumference. All the temperature measuring devices M i lie here in an imaginary plane that is perpendicular to the rotation axis 2 .
During operation of the gas turbine 1 , air L is taken in through the intake housing 4 by the compressor 5 , and compressed in the compressor duct 10 . The air L provided at the output of the compressor 5 on the burner side is led to the burners 7 by the diffuser 11 and mixed there with a fuel. The mixture is then burned in the combustion space 10 with the formation of a working fluid 20 . From there, the working fluid 20 flows into the hot gas duct 13 . The working fluid 20 expands at the guide vanes 16 arranged in the turbine 8 and at the moving vanes 18 in an impulse-transmitting manner such that the rotor 3 is driven and, with it, so is a driven machine (not illustrated) connected to it. The working fluid 20 is passed on as exhaust gas in the exhaust gas duct 9 . Each temperature measuring device M i then measures the temperature T i of the exhaust gas prevailing at its location.
FIG. 2 shows a Cartesian coordinate system P(x,y) with an exit temperature distribution at an instant t 0 .
The following definitions are made:
P(x,y)=a Cartesian coordinate system lying in the plane and which is intersected at right angles by the rotation axis 2 at the origin of coordinates P( 0 , 0 ), M i =the temperature measuring devices whose measuring points lie in the plane, n=24, the number of temperature measuring devices, T i =temperature of the temperature measuring device M i , for i=1 . . . n
Extending in the form of rays from the origin of coordinates P( 0 , 0 ) in the coordinate system P(x,y) are twenty-four auxiliary straight lines H i , for i=1 . . . n, in relation to each measuring point of the temperature measuring devices M i . Each auxiliary straight line H i therefore exhibits with reference to the positive x-axis an angle Θ i whose value is 15° or an integral multiple thereof.
For each temperature T i detected by the temperature measuring devices M i there is plotted on its associated auxiliary axis H i a point whose distance from the origin of coordinates P( 0 , 0 ) is proportional to the detected magnitude of the temperature T i . This results on each auxiliary axis H i , i=1 . . . n in a point dependent on the local temperature T i . The known trigonometrical functions are then used for each point in accordance with
T x i =T i ·cos(Θ i ), for i= 1 . . . 24 (1)
T y i =T i ·sin(Θ i ), for i= 1 . . . 24 (2)
to make a projection onto the two axes of the coordinate system.
In order to achieve an identical weighting of the measuring points, the temperature measuring devices M i are all arranged lying in a plane that extends perpendicular to the rotation axis 2 and therefore, at the same time, to the principal flow direction of the exhaust gas. Another nonuniform distribution of the temperature measuring devices M i over the circumference could likewise be carried out with the aid of the method.
In order to be able to determine a centroid S of the exit temperature distribution of the exhaust gas, the moments of the individual temperatures T i about the centroid S need to be in equilibrium. During the component by component consideration, that is to say for each axis of the coordinate system in each direction, it is therefore necessary in each case for the sums of the oppositely directed moments in accordance with
∑ i = 1 6 M + xi + ∑ i = 19 24 M + xi = ∑ i = 7 18 M - xi
and ( 3 ) ∑ i = 1 12 M + y i = ∑ i = 13 24 M - y i ( 4 )
to be in equilibrium. Each individual moment is calculated from a lever arm pivoted at the centroid S and which is multiplied by the component acting at the other end of the lever arm, that is to say the effective portion of the temperature T i . Since the centroid is unknown at first, the moments are calculated in the coordinate system component by component with reference to an as yet unknown reference value T GL , in accordance with
M +x i =( T +x i −T xGL )· T +x i (5)
M −x i =( T −x i +T xGL )· T −x i (6)
M +y i =( T +y i −T yGL )· T +y i (7)
M −y i =( T −y i +T yGL )· T −y i (8).
In order to calculate the centroid S, equations (5) and (6) are substituted in equation (3), and equations (7) and (8) are substituted in equation (4), and transformation is performed such that the reference value of the x-axis can be determined in accordance with
T xGL = ∑ i = 1 6 T + x i 2 + ∑ i = 19 24 T + x i 2 - ∑ i = 7 18 T - x i 2 ∑ i = 1 6 T + x i + ∑ i = 7 18 T - x i + ∑ i = 19 24 T + x i ( 9 )
and that of the y-axis can be determined in accordance with
T
yGL
=
∑
i
=
1
12
T
+
y
i
2
-
∑
i
=
13
24
T
-
y
i
2
∑
i
=
1
12
T
+
y
i
+
∑
i
=
13
24
T
-
y
i
.
(
10
)
The two reference values can then be combined as one centroid vector {right arrow over (S)} ges in accordance with magnitude
| {right arrow over (S)} ges |=√{square root over ( T xGL 2 +T yGL 2 )} (11)
and angle
φ
ges
=
tan
(
T
yGL
T
xGL
)
(
12
)
The origin of the centroid vector {right arrow over (S)} ges is situated here at the origin of coordinates P( 0 , 0 ) and ends at the centroid S that lies at the point P(T, xGL , T yGL ). The angle φ ges is referred to the positive x-axis in the mathematically positive sense, it being necessary when applying the tangent function to apply the customary considerations for the magnitude of the angle φ ges .
All the determined temperatures T i are combined in accordance with the above calculation to form a centroid vector {right arrow over (S)} ges in a a time-resolved—that is to say constantly recurring—fashion.
In FIG. 2 , the points of the temperatures T i plotted on the auxiliary axes H i are interconnected via a circumferential line 22 such that they jointly enclose a polygonal, virtually circular surface 23 whose centroid S is determined by applying the method.
The null vector would necessarily be yielded as centroid vector {right arrow over (S)} ges for an ideal gas turbine 1 with a symmetrical exit temperature distribution.
If the magnitude |{right arrow over (S)} ges | of the centroid vector {right arrow over (S)} ges increases substantially, the exit temperature distribution referring to the origin of the coordinate system is then increasingly deformed. If the magnitude |{right arrow over (S)} ges | decreases, the exit temperature distribution becomes more symmetrical.
FIG. 3 illustrates the time profile of the centroid vector {right arrow over (S)} ges in a combined magnitude/time and angle/time diagram. The centroid vector {right arrow over (S)} ges is described by the magnitude |{right arrow over (S)} ges | and the angle φ ges , the angle φ ges being illustrated with a dashed type of line, and the magnitude |{right arrow over (S)} ges | being illustrated as a continuous line.
In the stationary undisturbed operation of the gas turbine starting from the instant t=t 0 up to the instant t=t 1 , the characteristic of the magnitude |{right arrow over (S)} ges | runs in an approximately constant fashion inside a narrow fluctuation range. The angle φ ges is likewise to be considered as constant inside a narrow fluctuation range.
At the instant t=t 1 , a systematic variation that is identified by means of the method occurs during the stationary operation by means of a partial blockade of the turbine entrance space.
Starting from the instant t=t 1 , the angle φ ges changes substantially and drops approximately to half of its previous value. Starting from the instant t=t 2 , the magnitude |{right arrow over (S)} ges | moves outside its fluctuation range. The disturbance can be identified earlier and more easily owing to the not insubstantial change in the angle φ ges and in the magnitude |{right arrow over (S)} ges |.
Although the temperature changes were recorded with the aid of the monitoring methods previously known from the prior art, the slight systematic temperature changes do not overshoot the limiting values, and so no defective operation was diagnosed. Consequently, this case of disturbance—the partial blockade of the turbine entrance space with, resulting therefrom, excitations of vibrations of the first moving vane row, and subsequent vane breakages—was not identified early enough with the aid of a monitoring method in accordance with EP 1 118 920 A1.
The method described in EP 1 118 920 A1 does decompose the determined sliding mean values into two mutually perpendicular components from which a resulting variable having magnitude and angle is determined, but no weighting of the components is performed there, in particular no variable weighting, in the manner of a formation of moments. In the inventive method, each temperature T i , for example the temperature T +xi , acts with the lever arm assigned to it, for example T +xi minus T xGL ,—in a way comparable to a formation of moments in the physical sense—about the centroid S of the surface that is to be determined; in accordance with equations (5) to (8).
The displacement of the centroid S, that is to say the point P(T xGL ,T yGL ), also changes each lever arm and thus the weighting of each temperature T i . Consequently, the inventive method becomes extremely sensitive with respect to the smallest changes in the exit temperature distribution. In addition, the method constitutes a further improvement by comparison with the simple formation of mean values, since this simple formation of mean values, does not necessarily exhibit symmetrical temperature displacements, and provides no information relating to the geometrical alignment and rotation of the exit temperature distribution.
FIG. 4 shows the device for monitoring the centroid vector {right arrow over (S)} ges . It has an evaluation device 25 that applies the method. In this case, the evaluation device 25 is connected to all the temperature measuring devices M i and to a display device 26 . The evaluation device 25 uses the detected temperatures T i to calculate the centroid vector {right arrow over (S)} ges , and checks whether the magnitude |{right arrow over (S)} ges | thereof or the angle φ ges thereof lies outside a tolerance interval. If this is the case, the evaluation device 25 generates a signal for the display device 26 that then displays a disturbance as operating state. The display device 26 can be a monitor or a pilot lamp.
By continuously monitoring the magnitude |{right arrow over (S)} ges | and the angle φ ges , it is possible to identify the temporal change thereof at an early stage as a systematic variation in the absence of an external known influence. These then indicate defects or disturbances at an early stage such that consequential damage to the gas turbine can be avoided, or such that a well-timed intervention can be made in the operation of the turbine for corrective purposes.
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The invention relates to a method for identifying the operating condition of a turbine during operation. According to said method, a hot waste gas flows through a waste gas housing and the temperature of the waste gas in said housing is detected using temporal resolution. The aim of the invention is to provide a method for identifying the operating condition of a turbine during operation, which identifies and displays systematic errors. To achieve this, the numerous measured temperature values for the waste gas are respectively detected using local resolution with reference to the origin of an imaginary Cartesian co-ordinate system. The focal point of the temperature distribution is then determined, a vector between the origin of the Cartesian co-ordinate system and the focal point of the temperature distribution being used as an indicator for the operating condition of the turbines.
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BACKGROUND
[0001] The present disclosure relates to semiconductor lasers including, but not limited to, infrared or near-infrared distributed feedback (DFB) lasers, distributed Bragg reflector (DBR) lasers, Fabry-Perot lasers, etc. The present disclosure also relates to frequency-converted laser sources incorporating such lasers. More particularly, the present disclosure relates to fracture resistant metallization patterns for semiconductor lasers.
BRIEF SUMMARY
[0002] Although the various concepts of the present disclosure are not limited to lasers that operate in any particular part of the optical spectrum, reference is frequently made herein to frequency doubled green lasers, a schematic illustration of which is illustrated in FIG. 6 . In FIG. 6 , the frequency-converted laser source 100 comprises a laser diode 110 , a wavelength conversion device 120 , coupling optics 130 , collimating optics 140 , and an output color filter 150 . In the illustrated embodiment, the output of a laser diode 110 , which may be IR light, is coupled to the wavelength conversion device 120 , which may be a periodically poled MgO-doped lithium niobate SHG crystal or some other type of second or higher order harmonic wavelength conversion device, using the coupling optics 130 , which may comprise two aspheric lenses. Green light generated in the SHG crystal and residual IR pump light are collimated by the collimating optics 140 and residual IR light is eliminated by the color filter 150 .
[0003] Semiconductor lasers according to the present disclosure are equipped with metallization patterns to facilitate proper control of the laser diode. For example, in the context of a frequency-converted laser source 100 , particular metallization patterns are provided to provide means by which the emission wavelength of the laser diode 110 can be tuned to stay within the conversion bandwidth of the wavelength conversion device 120 during operation. Metallization patterns can also be provided for controlling the intensity or modulation rate of the laser diode 110 . Different portions of the metallization pattern can be dedicated to the control of different portions of the laser diode. Although the present disclosure is not limited to any particular type of control mechanism, conventional laser designs employ metal contact pads for current injection, thermal control, or both. The present disclosure also contemplates applicability for yet-to-be developed uses for metallization patterns in semiconductor lasers.
[0004] The fabrication of a semiconductor laser chip is complex and usually involves many process steps, including material growth, etching, metal deposition and polishing. After a laser chip is made, the chip, which is usually made of a brittle material such as semiconductor material systems based on GaAs, InP, GaP, GaN, GaSb, InAs, InN, InSb, or AlN, is mounted on a carrier. The carrier, which may be fabricated from AlN or any other suitable carrier material, provides needed functionality, i.e., electrical connections, mechanisms for heat dissipation, mechanical support, etc. This type of package, which is often referred to as a chip on hybrid (COH) device, is often an important component of wavelength converted laser sources, such as synthetic green lasers. COH devices are often characterized by significant rates of chip fracture, most often after the COH devices are exposed to temperature variations, which could be relatively low temperature cycling from −40 to 80 Celsius or relatively high temperature variations such as those encountered during soldering operations. The variation in the temperature during soldering operations could be from 300 C to room temperature.
[0005] The present inventors have recognized that chip fracture most commonly occurs near the boundaries of the metallization pads formed on the top surface of the semiconductor laser chip. Further careful inspection has revealed that theses fractures commonly start at the chip surface, near a metallization pad, and propagate through the cross-sectional plane of the semiconductor laser chip. Finite element simulation shows that tensile stress is created along the semiconductor chip after it is mounted on a carrier. It must be noted that magnitude and the nature (tensile or compressive) stress in the chip depends on the material properties of carrier on which the laser diode chip is attached to and the direction of temperature loading (heating or cooling). The critical material property that determines the nature of stress is coefficient of thermal expansion of laser diode chip and the carrier and the elastic modulus of both materials play a role in determining the magnitude of the stress. In addition, the nature of stress changes depending on whether the entire structure is being heated or cooled. For instance, during laser operation, the entire structure will be heated and during soldering operation, the entire structure will be cooled. If these stress concentration lines run generally parallel to a crystal plane of the laser chip fractures can easily propagate through the cross-section of the laser chip as the level of stress increases during temperature cycling.
[0006] In accordance with the embodiments of the present disclosure, metallization patterns are provided to reduce the probability of chip fracture in semiconductor lasers. According to one embodiment disclosed herein, the pad edges of a metallization pattern extend across a plurality of crystallographic planes in the laser substrate. In this manner, cracks initiated at any given stress concentration would need to propagate across many crystallographic planes in the substrate to reach a significant size.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0007] The following detailed description of specific embodiments of the present disclosure can be best understood when read in conjunction with the following drawings, where like structure is indicated with like reference numerals and in which:
[0008] FIG. 1 is a schematic plan view of a fracture resistant metallization pattern for a DBR laser diode;
[0009] FIG. 2 is a schematic illustration of the manner in which a metallization pattern can be oriented relative to the lattice planes of a laser chip;
[0010] FIGS. 3-5 illustrate some of the contemplated adjacent contact configurations according to the present disclosure; and
[0011] FIG. 6 is a generalized schematic illustration of a frequency-converted laser source incorporating a DBR laser diode.
DETAILED DESCRIPTION
[0012] Referring initially to FIGS. 1 and 2 , a semiconductor laser 10 is illustrated comprising a laser chip 20 mounted on a carrier substrate 30 . FIG. 1 illustrates a plan view of a metallized surface of the laser chip 20 , while FIG. 2 is a schematic illustration of a portion of the metallized surface 22 , a portion of the underlying crystallographic structure of the laser chip 20 , and a portion of the carrier substrate 30 . In FIG. 2 , the scale of the crystal lattice has been exaggerated for illustrative purposes.
[0013] The laser chip 20 may be any conventional or yet-to-be developed semiconductor laser such as, for example, a distributed Bragg reflector (DBR) laser, which comprises a gain section 12 , a phase control section 14 , and a wavelength selective section 16 . In any case, the laser chip 20 will comprise one or more of these types of crystallographic functional regions and a waveguide 25 extending along a longitudinal optical axis of propagation of the laser chip 20 through the crystallographic functional regions, 12 , 14 , 16 .
[0014] As is illustrated in FIGS. 1 and 2 , the metallized surface 22 of the laser chip 20 , which comprises metallic and non-metallic portions, comprises a metallization pattern 24 formed over the crystallographic functional regions 12 , 14 , 16 of the laser chip 20 . The metallization pattern 24 extends substantially parallel to the longitudinal optical axis of the laser chip 20 , as defined by the waveguide 25 . The crystallographic functional regions 12 , 14 , 16 , which may be fabricated from any conventional or yet-to-be developed semiconductor suitable for laser applications, are characterized by a lattice structure comprising a plurality of lattice planes L 1 , L 2 , L i , L j , . . . that intersect the metallized surface 22 of the laser chip 20 .
[0015] Typical laser diode metallization patterns will comprise a plurality of contact pads, which provide areas for bond wires, electrical connections, etc. Typical laser chips will require many different types of electrical connections, resulting in many separated metallization pads. These metallization pads can, for example, be made of 5-um thick gold on top of a SiN layer. Boundaries between two adjacent contact pads often run parallel to one of the primary lattice planes of the laser chip, e.g., crystal direction <011>. The present inventors have recognized a relatively large rate of chip fracture in these types of laser chips, typically after the laser chip has been mounted on a carrier and then treated at either low or high temperatures.
[0016] Chip fractures can degrade the characteristics of a laser diode drastically. More specifically, the present inventors have recognized that the optical spectrum of the laser can be more likely to become multimode, and jump from one wavelength to another wavelength randomly. In addition, laser output power can decrease more rapidly in a fractured laser chip. The present inventors have recognized that chip fractures can be caused by stress introduced by mounting a laser chip on a carrier and sequentially subjecting the chip-on-hybrid (COH) package to extreme temperatures. Finite element modeling and analysis of a 1060 nm laser chip package was conducted and revealed that mismatches in the respective coefficients of thermal expansion of the various package components causes thermo-mechanical stresses on the surface of the laser chip. Typical laser chips, like GaAs-based semiconductors, are relatively brittle and there is a high probability of chip cracking in the gap etch regions between the various functional regions of the laser chip.
[0017] The present disclosure introduces new metallization patterns for reducing or eliminating the aforementioned chip fracturing problem. Generally, features of the new patterns include, but are not limited to, slanted wire bond pads, 45 degree and 135 degree pad corners instead of 90-degree pad corners, and the provision of a continuous metallized bar, strip, or other portion 28 extending across the substantial entirety of the gain and phase control sections of the laser chip to enhance strength.
[0018] In the illustrated embodiment, the laser chip 20 comprises longitudinally adjacent contact pads P 1 -P 5 that form longitudinally adjacent pairs of contact pads, i.e., (P 1 , P 2 ), (P 2 , P 3 ), (P 3 , P 4 ), and (P 4 , P 5 ). To enhance the fracture resistance of this type of metallization pattern, opposing edges of the longitudinally adjacent pairs of contact pads P 1 -P 5 are oriented to extend across a plurality of the lattice planes L 1 , L 2 , L i , L j , . . . that intersect the metallized surface 22 of the laser chip 20 . In this manner, more energy would be required for a crack to propagate through the thickness of the laser chip because the pad edges are not aligned with any particular lattice plane. In addition, it is contemplated that the contact pads can be configured to occupy a majority of the metallization pattern and to form an intervening gap a that extends across a plurality of the lattice planes that intersect the metallized surface of the laser chip.
[0019] Referring again to FIGS. 1 and 2 , it is noted that typical metallization patterns will further comprise a plurality of conductive traces 26 that may be oriented substantially parallel to the lattice planes L 1 , L 2 , L i , L j , . . . . In some cases, these conductive traces and other types of conducting portions of the metallization pattern may run along particular crystalline plans of the device because the most problematic crack lines are often parallel to and away from the short edges of the chip. Similarly, the pad edges near the chip edges and along the long direction of the chip can also run along the crystalline planes without significant risk of cracking. Nevertheless, the influence of these conductive traces on the fracture resistance of the laser chip can be mitigated by ensuring that they do not dominate the surface area of the metallization pattern. Similarly, it is noted that additional edges of the longitudinally adjacent pairs of contact pads P 1 -P 5 may be oriented substantially parallel to the lattice planes L 1 , L 2 , L i , L j , . . . . To mitigate the influence of these additional edges on the fracture resistance of the laser chip, the metallization pattern can be designed to ensure that the additional edges are dominated in the metallization pattern by the opposing edges, which extend across the lattice planes L 1 , L 2 , L i , L j , . . . . Typically, the lattice structure of the laser chip will be orthogonally aligned relative to the optical axis of propagation but it is contemplated that the concepts of the present invention may be applied to lattice structures that are angularly misaligned relative to the optical axis of propagation.
[0020] As is noted above, the crystallographic functional regions of the laser chip may comprise a gain region 12 , a phase control region 14 , a wavelength selective region 16 , or combinations thereof. In particular embodiments, the adjacent pairs of contact pads will lie in the wavelength selective region 16 of the laser chip but it is also contemplated that adjacent pairs of contact pads may lie in one of the crystallographic functional regions of the laser chip, at an interface of adjacent crystallographic functional regions of the laser chip, or both.
[0021] It is noted that recitations herein of a component of the present disclosure being “configured” in a particular way, to embody a particular property, or to function in a particular manner, are structural recitations, as opposed to recitations of intended use. More specifically, the references herein to the manner in which a component is “configured” denotes an existing physical condition of the component and, as such, is to be taken as a definite recitation of the structural characteristics of the component.
[0022] For the purposes of describing and defining the present invention it is noted that the term “substantially” is utilized herein to represent the inherent degree of uncertainty that may be attributed to any quantitative comparison, value, measurement, or other representation. The term “substantially” is also utilized herein to represent the degree by which a quantitative representation may vary from a stated reference without resulting in a change in the basic function of the subject matter at issue.
[0023] It is noted that terms like “preferably,” “commonly,” and “typically,” when utilized herein, are not utilized to limit the scope of the claimed invention or to imply that certain features are critical, essential, or even important to the structure or function of the claimed invention. Rather, these terms are merely intended to identify particular aspects of an embodiment of the present disclosure or to emphasize alternative or additional features that may or may not be utilized in a particular embodiment of the present disclosure.
[0024] For the purposes of describing and defining the present invention it is noted that the term “approximately” is utilized herein to represent the inherent degree of uncertainty that may be attributed to any quantitative comparison, value, measurement, or other representation. The term “approximately” is also utilized herein to represent the degree by which a quantitative representation may vary from a stated reference without resulting in a change in the basic function of the subject matter at issue.
[0025] Having described the subject matter of the present disclosure in detail and by reference to specific embodiments thereof, it will be apparent that modifications and variations are possible without departing from the scope of the invention defined in the appended claims. More specifically, although some aspects of the present disclosure are identified herein as preferred or particularly advantageous, it is contemplated that the present disclosure is not necessarily limited to these aspects.
[0026] It is noted that one or more of the following claims utilize the term “wherein” as a transitional phrase. For the purposes of defining the present invention, it is noted that this term is introduced in the claims as an open-ended transitional phrase that is used to introduce a recitation of a series of characteristics of the structure and should be interpreted in like manner as the more commonly used open-ended preamble term “comprising.”
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Metallization patterns are provided to reduce the probability of chip fracture in semiconductor lasers. According to one embodiment disclosed herein, the pad edges of a metallization pattern extend across a plurality of crystallographic planes in the laser substrate. In this manner, cracks initiated at any given stress concentration would need to propagate across many crystallographic planes in the substrate to reach a significant size. Additional embodiments of the present disclosure relate to the respective geometries and orientations of adjacent pairs of contact pads. Still further embodiments are disclosed and claimed.
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BACKGROUND OF THE INVENTION
This invention relates to coupling structures for compound drill stems and more particularly to coupling structures that transmit torque from one drill stem section to another in roof drills.
Roof drills are utilized for drilling holes in the ceiling of a coal mine or the like. The holes are drilled to install bolts that are cemented into the holes. The bolts secure plates to the mine ceiling to prevent rocks and earth from falling from the ceiling.
When drilling holes for roof support, hard cutting conditions are encountered and water is needed as a coolant to prolong the life of the drill bit. Certain conventional arrangements that inject water up through drill stems to drilling area are effective to cool bits during drilling, but are not favored by drill operators because they are showered with a slurry of water and cuttings and because the quantity of water required produces muddy conditions on the bottom of the mine.
One known roof drill has a drill bit cooled by water injected through its drill stem to a drilling area and also extracts the water and accompanying cuttings from the drilling area to prevent the drill operator from being showered. This known arrangement employs multiple concentric passages in its stem, connected to a water source to provide cooling water to the drilling area and is connected to a vacuum source to suck off the water and cuttings from the drilling area. Such multiple length steels are necessary because of drilling long holes in areas where seam height prevents use of a one piece steel. Connections between steel sections are difficult because of this requirement for two-way passage.
SUMMARY OF THE INVENTION
The present invention relates to a coupling structure that can be used to connect a compound drill stem for roof drilling with a water-cooled drill bit, which extracts a slurry containing cuttings from a drilling area while the drill operator is kept completely dry.
In accordance with the present invention, two drill stem sections are connected by a coupling structure. Each of the sections has concentric inner and outer pipes that provide concentric inner and outer passages for fluid flow. The coupling structure connects the outer flow passages of the two sections in fluid communication and also connects their inner passages in fluid communication. The structure has a polygonal interior cross-sectional shape that is adapted to telescopically cooperate with a similarly shaped drill stem section to transmit torque from that drill stem section through the coupling structure to another drill stem section.
In the preferred embodiment, the coupling structure has a housing with a prismatic inner surface that is polygonal (i.e. hexagonal) in cross-section. The housing is fixedly attached at one end to one of the drill stem sections while its other end is telescopically fit over a similarly shaped, prismatic (i.e. hexagonal) outer surface of the other drill stem section. Within the housing, the inner passages of each drill stem section are connected by a collar attached to one of the two inner pipes and removedly received by a sleeve attached to the other inner pipe.
By connecting the drill stem sections with a telescopic fit, the present coupling structure permits easy assembly of a compound drill stem having concentric flow passages for various seam heights in the stem. It permits easy and rapid disassembly of the compound drill stem (without complex tools) for transportation of the drill, storage of the drill, cleaning and repair of the inside of the drill stem sections. Since the telescopic coupling is achieved by a mating of two polygonal shapes, torque is effectively transmitted from a driven stem section to another stem section attached to the coupling structure. The coupling structure effectively eliminates the need for complex couplings to achieve concurrent rotation of drill stem sections having communicating, concentric flow passages.
The above and other features, objects and advantages of this invention will become more apparent as the invention becomes better understood from the detailed description that follows when considered in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view, with portions broken away, of a roof drill that utilizes a coupling structure made in accordance with the present invention;
FIG. 2 is a longitudinal sectional view of a compound drill stem of the roof drill of FIG. 1, with other portions of the drill illustrated in phantom;
FIG. 3 is an enlarged cross-sectional view of a first drill stem section of the roof drill taken along lines 3--3 of FIG. 2;
FIG. 4 is an enlarged cross-sectional view of the first drill stem section taken along line 4--4 of FIG. 2;
FIG. 5 is an enlarged cross-sectional view of the coupling connection structure taken along line 5--5 of FIG. 2;
FIG. 6 is an enlarged cross-sectional view of a second drill stem section taken along line 6--6 of FIG. 2;
FIG. 7 is an enlarged cross-sectional view of the coupling structure and the first drill stem section taken along lines 7--7 of FIG. 2.
FIG. 8 is a fragmentary side elevation view partly in sections illustrating the coupling connection structure; and
FIG. 9 is a fragmentary section view taken along the line 9--9 of FIG. 8.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings, a roof drill assembly 10 having a drill bit 12 attached to a compound stem 14 is shown in FIGS. 1 and 2. The compound stem 14 is defined by first and second stem sections 16, 18 that are detachably connected by a coupling structure, designated generally at 20, and rotatably attached to a rotary power means (not shown) by a drive shaft 22, as known in the art. The coupling structure 20 includes a cylindrical housing 24 that is fixedly attached at one end to stem section 18 while its other end is telescopically fit over an end portion of stem section 16. The compound stem 14 has two concentric passages (FIGS. 2 and 9) for two-way fluid flow: an outer passage 30 supplies water to a cutting area 28 of a mine roof 29 and inner passage 26 is attached to a vacuum source (not shown) to extract a slurry of the water and accompanying cuttings from the cutting area through a plurality of passages 13 in the drill bit 12. This drill bit is commercially available under the trademark "DUST HOG" from the Mining Tools Division of Smith International Inc.
As best shown in FIGS. 2, 8 and 9, the first or lower stem section 16 includes two aligned outer pipes 32, 33 (may be formed as one) attached by a weld 34 to form a passage of constant diameter. An inner pipe 35 is spaced from and is concentric with the outer pipes 32, 33. The inner pipe 35 is polygonal (i.e. hexagonal) in cross-section (FIG. 3), and is attached at one end to the inner surface of the pipe 32 by a circumferential weld 36. An outer passage 30a extends between the inner pipe 35 and the outer pipes 32, 33 and forms a portion of the outer passage 30 for the compound stem 14. The inner pipe 35 has a central passage 26a which forms a portion of the inner passage 26 of the compound stem.
The outer pipe 32 has a prismatic surface 39 that is hexagonal in cross-section (FIG. 3) and received in a similarly shaped bore (not shown) in the drive shaft 22. The pipe 32 and the drive shaft 22 cooperate to transmit torque from the shaft to the pipe 32 so as to turn the compound stem 14 within a stationary swivel housing 40. The pipe 32 has a circular collar 42 that abuts an end of the drive shaft 22 to limit vertical movement of the pipe 32 in the bore and to apply drilling thrust to the drill bit 12. The other outer pipe 33 has a constant inner diameter with the outer surface portion 48 of the pipe 33 being circular in cross-section (FIGS. 4 and 8). Preferably, all the pipes have a circular outer surface configuration
The housing 24 is fixedly attached to the second stem section 18 by a weld 55 (FIGS. 2 and 9) and has a prismatic inner surface 52 that is hexagonal in cross-section (FIGS. 5 and 7) and telescopically fit over a similarly shaped outer integral step surface 53 of the pipe 33. An O-ring 54 or similar type gasket fits between the housing 24 and the step surface of the inner pipe 33. The O-ring 54 should be of a flexible, high strength plastic or elastomeric (i.e. rubber material) and fits within a recess or groove 51 provided in a shoulder 50 formed in the outer surface 48 of the pipe 33, as best seen in FIG. 9. This provides a fluid seal between the stem sections 16 and 18 in the installed condition of the coupling. The prismatic surfaces 52, 53 facilitate attachment of the stem sections 16, 18 by eliminating pinning or other complicated coupling arrangements.
In the invention a reduced diameter sleeve 56 is attached (FIG. 9) to an end of the inner pipe 35 by a weld 58. The sleeve 56 is circular in cross-section and is concentric with the inner pipe 35 and is radially spaced from the coupling housing 24 to form a passage portion 30b (of the outer passage 30) between the sleeve 56 and housing 24. The passage 30b is connected in fluid communication with the outer passage 30a of the first stem section 16 by a series (i.e. six) holes 57 spaced circumferentially at an end portion of the hexagonal, step section 53 of inner pipe 33. By this arrangement, input fluid (i.e. water) is forced under pressure through the passages 30, 30a and 30b via holes 57 which are disposed at each of the apex edges defining the hexagonal surface of the integral step surface 53.
The second or upper stem section 18 has inner and outer concentric pipes 62, 64 that are radially spaced apart to form a passage portion 30c which is a extension of the outer passage 30 between them. Accordingly, the outer passage 30c is connected in fluid communication with the outer passage 30a of the first stem 16 a female nipple 70 attached thereto by a weld 72 section by the passage 30b provided in the coupling structure 20. One end of the inner pipe 62 has the nipple 70 for a collar 73 and an integral cylindrical shank 75. The shank 73 has a circular cross-section (FIG. 5) and is removedly and slidably received within the hollow sleeve 56. An O-ring 71 (rubber or plastic) fits within a groove 77 of sleeve 56 and acts as a seal to prevent undesired fluid communication between the outer passage 30 and the inner passage 26. The inner pipe 62 of the second section 18 has a central or inner passage 26b that forms a portion and continuation of the inner passage 26 of the compound stem 14. The passage 26b is connected in fluid communication with the central passage 26a of the first stem section 16 by hollow bores provided in the nipple 70.
In the embodiment shown, a drill bit seat 74 has a hollow bore (FIG. 1) and is attached to the free end of the second stem section 18 by weldmounts 76, 78. The drill bit 12 is removably attached to the bit seat 74 (as known in the art) and has a plurality of dust collection passageways 13 that communicate with a space 79 between the bit 12 and bit seat to provide a fluid communication between the cutting area 28, the hollow bore of the drill bit seat, and the inner passage portions 26a, 26b of the compound stem 14 via the coupling structure 20 of the invention
During drilling, water enters a conventional type swivel housing 40 which allows the drill stem sections 16 and 18 to rotate while a water hose (not shown) connected to the housing remains stationary. The water then enters the compound stem 14 through an input orifice 80 (FIG. 1) in the first stem section 16 and travels up the compound stem through the outer passage 30 until it exits through a series (i.e. four) discharge openings 82 provided in the outer pipe 64 of the second stem section 18. The discharge openings 82 are preferably canted or inclined to induce direct the flow of water in an upward and outward direction. From this point, the water is drawn by the vacuum (via the inner passage 26) upwards to the cutting area 28 and to the bit 12. The water cools the bit, which causes the bit to retain its sharp edge longer. These and other advantages of this "DUST HOG" type bit are shown and described in applicants co-pending application Ser. No. 170,352 which is incorporated herein by reference. A slurry containing the water and accompanying cuttings from the drilling area 28 is then drawn through the dust collection holes 13 in the bit 12 and down the inner passage 26 of the compound stem 14 to a collection box (not shown) in which it is retained until a suitable place is encountered for its disposal.
While the preferred embodiment of the invention has been disclosed in detail, various modifications or alterations may be made therein without departing from the spirit or scope of the invention set forth in the appended claims.
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Coupling structure to connect sections of a compound drill stem. The drill stem has concentric passages, one connected to a fluid source to provide fluid in an area being drilled and another connected to a vacuum source to carry off the fluid and accompanying cuttings from the drilling area. In the preferred embodiment, the coupling structure includes a housing with a prismatic surface that telescopically cooperates with a similarly shaped surface of at least one of the drill stem sections to effectively transmit torque through the compound stem.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an adjustable, universal screed guide/control joint clip used in the positioning of screed guide/control joints, which in turn are utilized in the placement of concrete in concrete slabs, the screed guides provide precise placement of the concrete in concrete slabs, the adjustable, universal screed guide clip allowing for exact adjustment of the height of the screed guide, as well as allowing the installation of the screed guide in applications heretofore denied.
[0003] 2. Description of the Prior Art
[0004] The pouring and use of concrete is a fundamental construction task in the trade. It is referred to as the placement of concrete. It is often required in the installation of sidewalks. It is placed over steel decks to provide the flooring base for multi-story skyscrapers; it is placed for the flooring of large warehouse or industrial structures; and it is placed to form the basis for water retention basins and reservoirs. It further provides the basis for highway surfaces and airport runways.
[0005] There are two essential joints associated with concrete slabs. The first joint is commonly referred to as the expansion joint and passes completely through the concrete slab. The expansion joint is designed to allow for the expansion and contraction of the concrete slab in response to ambient temperature conditions. The second joint is commonly referred to as the control joint. The control joint is a linear impression formed in the concrete slab after its placement. It does not extend through the concrete slab. The purpose of the control joint is to control the direction of any cracking which may appear in the slab over time. Typical control joints would run transversely on the slab from one edge to the other. Control joints would normally be formed by dragging a trowel across the poured concrete while it was still wet to form the linear impression, and in some instances, diamond saws would be used to form the control joints after the concrete slab had hardened.
[0006] In the prior art, any handy material would be utilized to form the peripheral outline or frame of the concrete slab and any associated expansion joints. The concrete would be placed within the frame and leveled using a screed which would be dragged across the surface of the wet concrete while resting on at least two adjacent or abutting framing members in order to achieve a planar level slab. The framing members upon which the screed rested while leveling the surface of the concrete slab are referred to in the trade as screed guides.
[0007] European building codes require a ten year guarantee with respect to poured concrete slabs. No such guarantee is required or exists in US building codes. This dichotomy has led to greater technical advances in Europe with respect to the pouring of concrete slabs. In particular, a screed guide profile has been developed in which the screed guide itself also forms the control joint for the concrete slab. The use of these combination screed guide/control joints presents some great advantages in the area of placement of concrete slabs and in the life expectancy of the concrete slabs. However, the accurate placement of the screed guide/control joints sometimes proved laborious and time consuming.
[0008] Initially, some screed guide/control joints were positioned by pouring small mounds of concrete in a desired linear direction before positioning of the screed guide/control joint. The screed guide/control joint would then be positioned on the small mounds of concrete to the desired height, and the mounds of concrete would be allowed to set. Once the mounds of concrete had set, securing the screed guide/control joint, the concrete slab would be poured to the height of the upper edge of the screed guide/control joint. This method became laborious and time consuming since normally 24 hours would have to elapse from the time that the mounds of concrete were poured until the time that the slab could be poured to allow for the mounds to set and position the screed guide/control joint.
[0009] The method of installing screed guide/control joints evolved to the use of rebar stakes, and clips. The section of rebar would be pounded into the ground to an estimated height, each rebar being positioned approximately two feet apart. Clips would then be installed on the top of the rebar, the upper portion of such clips presenting a dove tail channel into which a preformed plastic screed guide/control joints having a pyramidal cross section would snap fit. The worker would hand adjust the depth of the rebar in order that the clips were at the same height so that the screed guide/control joint presented a level upper edge for placement of the concrete slab. This method presents problems when a vapor barrier is utilized, since the rebar stakes will pierce the plastic sheets or other types of vapor barriers and degrade their performance. It also presents a problem when concrete flooring is being placed on a steel deck as is done in the construction of multi-story buildings or skyscrapers. The rebar stake cannot be driven into or through the steel deck.
[0010] It presents an additional problem in those instances where concrete slabs are being placed onto compacted gravel subgrade or ground. Some installations call for void forms to be placed beneath the concrete slab at various locations to compensate for the expansion and contraction of the ground due to expansion and contracting soil conditions. These voided areas are formed utilizing cardboard housings which are positioned prior to the placement of the concrete slab, the slab being placed essentially over the cardboard encapsulating the cardboard housing between the concrete and the ground. The void area under the cardboard housing and in contact with the ground provides compensation for expansion and contraction of the ground. The cardboard housing over time will eventually deteriorate, but the void will remain. The use of the rebar stakes or any stake on such a slab would pierce the cardboard housing and obviate its desired purpose of forming a void between the poured concrete and the ground.
[0011] An additional problem associated with the current installation of screed guide/control joints is that the profile of the screed guide/control joint varies depending on the thickness of the concrete slab. Two sizes of screed guide/control joint profiles are currently used for screed guide/control joint placement in various thicknesses of concrete slabs. A large profile screed guide/control joint is utilized for placement of six inches or greater, and a small profile screed guide/control joint is used for placements of lesser thickness. Since the size of the screed guide/control joints vary, the installer must inventory a quantity of clips that will fit the two profiles.
[0012] This screed guide profile and the advantages thereof would find greater acceptance both in Europe and the US if the aforesaid disadvantages could be overcome. Applicant's system addresses and overcomes each disadvantage.
OBJECTS OF THE INVENTION
[0013] An object of the present invention is to provide a novel screed guide/control joint clip system to accelerate and facilitate the accurate placement of the screed guides and limit the use of different sizes of clips.
[0014] A further object of the present invention is to provide for a novel screed guide/control joint clip system which allows for the facile and exact adjustment of the height of the screed guide/control joint clip and the screed guide/control joint.
[0015] A still further object of the present invention is to provide for a novel screed guide/control joint clip system which permits the use of the system on substrates which heretofore would not accept the system.
[0016] A still further object of the present invention is to provide for a novel screed guide/control joint clip system which incorporates a base member securable to a substrate of the type which did not previously permit the usage of a screed guide/control joint.
SUMMARY OF THE INVENTION
[0017] An adjustable, universal screed guide/control joint clip for positioning screed guide/control joints utilized in the placement of concrete in concrete slabs, the adjustable universal screed guide clip allowing for the exact adjustment of the height of the screed guide attached thereto for the placement of the concrete slabs, the adjustable universal screed guide clip allowing the installation of the screed guide in applications heretofore not allowable, the adjustable, universal screed guide/control joint clip capable of accommodating both large and small profile screed guides.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] These and other objects of the present invention will become apparent, particularly when taken in light of the following illustrations wherein:
[0019] FIG. 1 is a perspective view of a screed guide/control joint utilized with the present invention;
[0020] FIG. 2 is a perspective view of the screed guide/control joint of FIG. 1 illustrating a prior art method of installation;
[0021] FIG. 3 is an exploded perspective view of the screed guide/control joint of FIG. 1 and a second prior art method of installation;
[0022] FIG. 4 is a top view of the screed guide/control joint clip of the present invention;
[0023] FIG. 5 is an end view of the screed guide/control joint clip of the present invention;
[0024] FIG. 6 is a side view of the screed guide/control joint clip of the present invention;
[0025] FIG. 7 is a perspective view of the threaded cap rebar engaging member;
[0026] FIG. 8 is a cross sectional view of the screed guide/control joint clip and threaded cap rebar engaging member along Plane 8 - 8 of FIG. 4 ;
[0027] FIG. 9 is an end view of the screed guide/control joint clip of the present invention in orientation for receipt of a low profile screed guide/control joint;
[0028] FIGS. 10A and 10B are bottom views of the threaded cap rebar engaging member illustrating two embodiments of the orientation of internal ribbing to accommodate various diameter rebar;
[0029] FIG. 11 is a top view of a base member allowing use of the screed guide/control joint clip system on vapor barriers, steel substrate and void forms;
[0030] FIG. 12 is a side view of the system installed on a steel substrate;
[0031] FIG. 13 is a top view of a second embodiment of a screed guide/control joint clip of the present invention; and
[0032] FIG. 14 is an end view of the second embodiment of the screed guide/control joint clip illustrated in FIG. 13 .
DETAILED DESCRIPTION OF THE INVENTION
[0033] FIG. 1 is a perspective view of a screed guide/control joint utilized in the present invention. The screed guide/control joint 10 is linear in shape generally coming in 12 to 16 foot lengths to be cut in the field to the desired length required. It is formed of extruded polymer and has a base portion 12 comprised of a bottom wall 14 , two opposing side walls 16 and 18 , angled upper walls 20 and 22 terminating in an upwardly extending tower portion 24 , triangular in cross section formed by two angled side walls 26 and 28 and terminating in an apex which forms the upper edge 30 of screed guide/control joint 10 . The interior 32 of the base and tower portions are formed during the extrusion process with cross member ribs 34 for support. Additionally, the angled side walls 26 and 28 of tower portion 24 may also be formed with longitudinal parallel ribs 36 to aid in the setting process when screed guide/control joint 10 is encapsulated in concrete.
[0034] In most instances, the bottom wall 14 of the base member is not planar, but rather, slightly flared downwardly at its side walls 16 and 18 to aid in its snap fitting with a screed guide/control joint clip as described hereafter.
[0035] It should also be noted that FIG. 1 illustrates the general shape of the screed guide/control joint used with the present invention, however, minor variations, particularly with the longitudinal ribs on the exterior of the tower, may vary from manufacturer to manufacturer. It should also be pointed out that screed guide/control joints generally are formed in two sizes, large profile and small profile. The small profile screed guide/control joints are used with concrete slabs up to six inches in depth, and the large profile screed guide/control joints are used for slabs in excess of six inches in depth. The large profile and small profile screed guide/control joints are similar in all aspects except their dimensions. A typical large profile screed guide/control joint would have a base portion with slightly over two inches and a tower portion height of approximately three to three and a half inches, whereas the small profile screed guide/control joint dimensions would be approximately half those of the large profile screed guide.
[0036] FIG. 2 is a perspective view of screed guide/control joint 10 of FIG. 1 illustrating its setting with respect to a prior art method of installation. In this method of installation, small mounds of concrete 50 are poured in a linear orientation approximately two feet apart so that the base portion 12 of the screed guide/control joint may be set on these concrete mounds and the mounds allowed to harden and secure the screed guide/control joint. Once set, the concrete slab would be placed, encapsulating the entire length of the screed guide/control joint to the height of its upper edge 30 . Depending upon the area of concrete to be placed, a plurality of screed guide/control joints would be set in this manner, the desired distance apart in accordance with code, in order to define the area of concrete to be placed. This method of setting the screed guide/control joint is very time consuming, laborious, and requires exacting measurements to ensure that upper edge 30 is at a consistent height along the length of the screed guide/control joint and on all similarly situated screed guide/control joints.
[0037] The desire is to obtain a concrete slab of some dimension which has a uniform planar upper surface. To that end, the initial concrete mounds 50 that are placed must be of the desired height and the screed guide/control joint must be set at the accurate height, as well as all parallel and abutting screed guide/control joints to insure that the upper edge 30 of all of the screed guide/control joints utilized to define the concrete slab are at the same height. This can best be described as a hit or miss method of obtaining a uniform planar concrete slab.
[0038] FIG. 3 is an exploded perspective view of the screed guide/control joint of FIG. 1 and an alternative method for installation developed in the prior art. In this configuration a plurality of lengths of rebar 60 are driven into the underlying substrate 62 to a desired height 64 . The rebar is installed in a linear orientation approximately two feet apart. A screed guide/control joint clip 66 is then frictionally positioned on the upper extended end 68 of the rebar 60 . The screed guide/control joint clip 66 comprises a tubular base 70 which slidably engages the upper end 68 of the rebar 60 . Unitarily formed to the upper end of tubular base 70 is a dove tail channel 72 . Dove tail channel 72 is dimensioned to the width of the base portion 12 of screed guide/control joint 10 .
[0039] The installer would adjust the height of the sections of rebar 60 by hand to insure that the screed guide/control joint clips 66 were all at the same height. The screed guide/control joint would then be snap fit into the dove tail channel 72 of the screed guide/control joint clip, thus securing the screed guide/control joint at a desired height above the substrate 62 . The installer would take measurements to insure that the upper edge 30 of all screed guide/control joints 10 utilized and placed in order to place the concrete slab were all at the same height. The concrete would then be placed encapsulating the rebar 60 , the screed guide/control joint clip 66 and the screed guide/control joint 10 to the height of its upper edge 30 . Sections of the concrete slab would be placed in succession between each screed guide/control joint so positioned.
[0040] This method, while an improvement over the use of small poured concrete mounds, still required checking by the installer to insure that the upper edges 30 of all of the screed guide/control joints 10 were at the same level, and required multiple adjustments of the height of the rebar, since the screed guide/control joint would not snap fit and lock into the dove tail channel 72 of the screed guide/control joint clip 66 unless all screed guide/control joint clips 66 were at the same height.
[0041] Applicant's screed guide/control joint clip provides several advantages over the prior art. First, it can accommodate both large profile and small profile screed guide/control joints in one clip assembly. Secondly, its construction allows for a firm grip on both European rebar which measures approximate 12 mm in diameter, and US rebar, which is slightly larger at 12.57 mm. Thirdly, the interior member which is exteriorly threaded easily allows for the accurate height adjustment of the screed guide/control joint clip to insure that the upper edges of all screed guide/control joints are level when installed on the screed guide/control joint clip. Lastly, the incorporation of a base support member cooperable with the rebar, allows for the use of screed guide/control joints where vapor barriers and liners are initially installed over the substrate, allows for the use of Applicant's screed guide/control joint clip in conjunction with screed guide/control joints on steel substrate for multi-story skyscrapers, and allows for the use of screed guide/control joints on void forms. All of these areas were previously denied the use of screed guide/control joints because of the required installation methods previously discussed.
[0042] FIG. 4 is a top view of the screed guide/control joint clip of the present invention, FIG. 5 is an end view of the screed guide/control joint clip of the present invention, and FIG. 6 is an opposing end view of the screed guide/control joint clip. The screed guide/control joint clip 80 cooperates with a threaded cap rebar engaging member 82 illustrated in FIG. 7 , which will be more fully discussed hereafter. Screed guide/control joint clip 80 comprises a tubular member 84 having an internal bore 86 , internal bore 86 having a single threaded member 88 cooperable with threaded cap rebar engaging member 82 as more fully discussed with respect to FIG. 8 hereafter. Unitarily formed with tubular member 84 is a first dove tail channel member 88 having a base portion 90 and two opposing upstanding side walls or prongs 92 and 94 , upstanding side walls or prongs 92 and 94 being slightly inwardly protruding at their upper terminus 96 and 98 to define a channel 100 for engagement with the base member 12 of a large profile screed guide/control joint 10 snap fit there between.
[0043] A second inverted dove tail channel member 102 is unitarily hingeably secured 106 to an open edge 104 of first dove tail channel member 88 . Second, inverted dove tail channel member 102 in the configuration illustrated in FIGS. 4 , 5 , and 6 has a base member 108 , and depending outer side walls or prongs 110 and 112 . Second inverted dove tail channel member 102 also has the two inner side walls or prongs 114 and 116 spaced apart from outer side walls or prongs 110 and 112 depending downwardly and terminating with a nubbed apex similar to the side walls of first dove tail channel member 88 . The distance between the downwardly depending inner side walls or prongs 114 and 116 corresponds to the width of the base of a small profile screed guide/control joint.
[0044] Referring to FIG. 9 , which is an end view of the screed guide/control joint clip of FIGS. 4 , 5 , and 6 with the second dove tail channel member 102 in hinged relationship with the first dove tail channel member 88 . The flexible hinge 106 allows for second dove tail channel member 102 to be rotated 180 degrees such that its outer side walls or prongs 110 and 112 frictionally lock in a snap fit manner with the side walls or prongs 92 and 94 of first dove tail channel member 88 . This positions the inner side walls or prongs 114 and 116 of second dove tail channel member 102 in a central upwardly extending position converting the screed guide/control joint clip 80 from one accommodating a large profile screed guide/control joint to one which can now accommodate a low profile screed guide/control joint, thus the elimination of two separate sized clips for the installation and pouring of concrete.
[0045] It will be noted that the base members 90 and 108 of first and second dove tail channel members 88 and 102 are not planar, but are slightly arcuate to accommodate the contour of the base member 12 of either a large profile or small profile screed guide/control joint. Additionally, the base members 90 and 108 of first and second dove tail channel members 88 and 102 may also be formed with apertures 120 and 122 to aid in the molding process.
[0046] FIG. 7 is a perspective view of threaded cap rebar engaging member 82 . FIGS. 10A and 10B are bottom views of two embodiments of threaded cap rebar engaging member 82 . Threaded cap rebar engaging member 82 is tubular having an exterior threaded surface 130 and an interior surface 132 having a plurality of radial or non-radial ribs 134 protruding inwardly from inner surface 132 . The ribs 134 , being non-radial in orientation with respect to tubular threaded cap rebar engaging member 82 allows for threaded cap rebar engaging member 82 to be utilized with respect to both European and United States rebar dimensions, thus allowing for threaded cap rebar engaging member to be snap fittingly engaged over an end of either type of rebar. Radial ribs may also be used but sized accordingly for the size of rebar utilized.
[0047] FIG. 8 is a cross sectional view of the screed guide/control joint clip and threaded cap rebar engaging member along Plane 8 - 8 of FIG. 4 . Screed guide/control joint clip 80 has a single internal thread 88 cooperable with the external threading 130 on threaded cap rebar engaging member 82 to allow for the height adjustment of the screed guide/control joint clip 80 once the threaded cap rebar engaging member 82 has been snap fit over an end of rebar. This allows screed guide/control joint clip 80 to be accurately rotated on threaded cap rebar engaging member 82 to achieve the desired height.
[0048] The screed guide/control joint clip system described thus far eliminates the need for concrete mounds to be poured and measurements to be taken with respect to the placement of screed guides on such concrete mounds. It also eliminates the eyeball measurements and adjustment of the depth of rebar in the substrate in order to achieve equality in screed guide levels. The addition of a base member to a system previously described, also allows for the use of the system in those instances where a liner or vapor barrier is required over the substrate or where the substrate is steel, and also where conditions require that void forms be provided in the concrete slab for the underlying expansion and contraction of the substrate.
[0049] FIG. 11 is a top view of a base support member 140 designed to be utilized with the screed guide/control joint system, and FIG. 12 is a side view of the base member with the screed guide/control joint clip system installed on a steel substrate. The base member 140 comprises a planar base 142 of any particular geometric shape, but illustrated as being circular in FIGS. 11 and 12 . Centrally positioned on planar base 142 and unitary therewith is upstanding tubular member 144 having an outer side wall 146 and an inner side wall 148 there being a plurality of radial or non-radial rib members 152 extending inwardly from the inner side wall 148 . Positioned about the planar base 142 would be a plurality of apertures 150 extending through planar base 142 . Additionally there may be a central aperture 153 through planar base 142 positioned within tubular member 144 .
[0050] In this configuration, an appropriate adhesive 156 would be applied to either the substrate 158 or the undersurface 160 of planar base 142 and base member 140 would then be positioned on the substrate 158 . The application of the adhesive 156 would be such that it would adhere the under surface 160 of base member 142 and to the substrate, but would also pass through or ooze through the various apertures 150 and 153 in the planar base so as to extend to the upper surface of planar base 142 thus insuring firm adhesion of base member 140 to the substrate 158 , be it steel, vapor barrier, or cardboard void forms.
[0051] An appropriate length of rebar 60 would then be engaged in tubular member 144 and rigidly maintained by the rib members 152 extending therein. The installer would secure base members 140 in this fashion at the required distances on the substrate. The installer would then snap fit a threaded cap rebar engaging member 82 onto each piece of rebar 60 , and threadedly secure and adjust screed guide/control joint clip 80 to the threaded cap rebar engaging member 82 such that the heights of the base members 90 or 108 of the dove tail channel members 88 or 102 would be equal. Screed guide/control joints would then be snap fit and installed to the screed guide/control joint clips 80 and concrete would be placed encapsulating the base member 140 , the rebar 60 , the rebar engaging member 82 , the screed guide/control joint clip 80 , and the screed guide/control joint 10 .
[0052] FIG. 13 is a top view of a screed guide/control joint clip 80 B similar to the screed guide/control joint clip 80 illustrated in FIG. 4 , and FIG. 14 is an end view of screed guide/control joint 80 B from end. Screed guide/control joint clip 80 B has a similar tubular member 84 , having an internal bore 86 , internal bore 86 having a single threaded member 88 cooperable with the threaded cap rebar engaging member 82 as discussed with respect to FIG. 8 . Screed guide/control joint clip 80 B also has an identical first dovetail channel member 88 .
[0053] A second dovetail channel member 102 B is unitarily secured to open edge 104 B of first dovetail channel member 88 by means of a flexible hinge arm 106 B. Second dovetail channel 102 B is identical to the second dovetail channel member 102 as illustrated in FIG. 4 with the exception that it is not inverted. Flexible hinge arm 106 B is of sufficient length to allow second dovetail channel member 102 B to be twisted or turned 180 degrees in a plane allowing for outer side walls or prongs 110 B and 112 B to be snap fit or inserted into first dovetail channel member 88 such that the two inner side walls or prongs 114 B and 116 B are in position for receipt of a small profile screed guide. Flexible arm 106 B eliminates the hinge 106 illustrated in FIG. 4 and presents an alternative manner for the production of the screed guide control joint clip.
[0054] Therefore, while the present invention has been disclosed with respect to the preferred embodiments thereof, it will be recognized by those of ordinary skill in the art that various changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore manifestly intended that the invention be limited only by the claims and the equivalence thereof.
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An adjustable, universal screed guide/control joint clip for positioning screed guide/control joints utilized in the placement of concrete in concrete slabs, the adjustable universal screed guide clip allowing for the exact adjustment of the height of the screed guide attached thereto for the placement of the concrete slabs, the adjustable universal screed guide clip allowing the installation of the screed guide in applications heretofore not allowable, the adjustable, universal screed guide/control joint clip capable of accommodating both large and small profile screed guides.
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