The present invention refers to an ink jet receiving sheet comprising a support and at least an ink receiving layer comprising a binder selected from the group consisting of gelatin and gelatin derivatives, characterized in that said at least an ink receiving layer comprises at least a copolymer consisting in at least one N-vinylpyrrolidone monomer and at least a second monomer selected from the group of N-vinylcaprolactam monomers and N-vinylpiperidone monomers to improve post printed drop sweating in the resulting image, still maintaining a good glossiness.

The invention relates to an ink receiving sheet for ink-jet printing and, more particularly, to a receiving sheet comprising a copolymer consisting in at least one N-vinylpyrrolidone monomer and at least one second monomer selected from the group of N-vinylcaprolactam, and N-vinylpiperidone monomers to improve post printed drop sweating in the resulting image, still maintaining a good glossiness.
Ink jet printing has become increasingly popular, particularly for so-called xe2x80x9cdesk-top publishingxe2x80x9d, because of its capability to produce small volumes of printed matter from digital input at high throughput speeds. Recent equipment developments have led to the introduction of multi-color ink jet printers that integrate colored graphics and text. To some extent, however, the applications of ink jet printing have been limited due to the demanding requirements the ink receptors must meet in order to provide high quality text and graphics.
It is desirable that receiving media for inkjet printing are capable of absorbing significant amount of liquid to ensure that the surface of said receptors be dry and non tacky to the touch after printing; but it is also desirable to maintain durability of printing image.
In case of multicolor ink-jet receptors, the ink-receiving layer is often subjected to multiple print, one for each primary color (yellow, magenta and cyan). During the first or second print, the amount of organic compounds absorbed in the layer can be partially desorbed creating on the image surface a local organic compound concentration that are visible as drop. Where a yellow ink is absorbed by the ink receiving layer after that cyan and magenta inks have been already absorbed therein, it is possible to have the formation of yellow colored drops in specific areas on the surface of the receiving layer, areas that have been saturated with cyan and magenta inks and that are no more able to properly absorb additional inks. This problem is generally known as post printed drop sweating.
U.S. Pat. No. 4,649,064 discloses a rapid-drying image-recording element adapted for water-based liquid ink marking, in devices such as pen plotters, ink jet printers and the like, comprising a support having thereon a hydrophilic ink-receiving layer which is cross-linked to a degree sufficient to render it non-blocking and waterfast while permitting it to rapidly absorb a water-based liquid ink. The element is utilised in combination with a water-based liquid ink that comprises a water-dispersible cross-linkable colorant/resin composition and the ink-receiving layer contains a cross-linking agent which cross-links the colorant/resin composition to thereby render the ink markings smear-resistant, abrasion-resistant and waterfast.
U.S. Pat. No. 5,919,558 discloses typical water soluble and non-water soluble polymeric binders for inkjet coatings, such as, for example, poly(vinylpyrrolidone), vinylpyrrolidone-vinyl acetate copolymers, or mixtures thereof. U.S. Pat. No. 4,425,405 discloses such a mixture applied on at least one surface of a paper substrate or incorporated internally of the substrate with a white filler in a pigment-to-binder weight ratio of 10:1 to 0.2:1. In addition, U.S. Pat. No. 4,503,111 discloses the use of poly(vinylpyrrolidone) as the binder in an inkjet recording sheet which uses a hydrophobic substrate prepared from a flexible, transparent plastic material.
U.S. Pat. No. 5,939,469 discloses a base material and a coating on said base material for binding anionic dyes of ink-jet inks to the base; said coating comprises (a) 50 to 99.5% by weight of a basic vinyl heterocycle selected from the group consisting of N-vinylimidazole, 2-methyl-1-vinylimidazole and a mixture thereof; said vinyl heterocycle having a pKa of at least 3.8; (b) 0 to 49.5% by weight of a further copolymerizable monomer; and (c) 0.5 to 10% by weight of a crosslinker. In particular, the further copolymerizable comonomer (b) is selected from the group consisting of N-vinylpyrrolidone, N-vinylcaprolactam, N-vinyl-1,4-dihydropyridine and a mixture thereof.
U.S. Pat. No. 4,904,519 describes an ink jet recording sheet comprising a transparent polymeric backing having on at least one major surface thereof a transparent, ink-receptive layer comprising a cross-linked, hydrolyzed copolymer of a vinyl ester comonomer selected from the group consisting of vinyl acetate, vinyl propionate and vinyl stearate, and a vinyl amide comonomer selected from the group consisting of N-vinyl pyrrolidone and vinyl acetamide, the degree of hydrolysis being from about 80 to 95%, and the cross-linking being effected by an agent selected from the group consisting of borates, titanates, dichromates and aldehydes.
When the ink receptor media is printed with high quantity of ink, water and other components are absorbed by the coated layer and retained inside the film. At high humidity conditions, they tend to come off the layer and to coalesce in form of small drops on the surface, causing an oily feeling to touch and several handling problems. EP Patent Application 763,433 claims an ink jet recording medium containing at least one nitrogen-containing component to be selected from poly(vinylpyrrolidone), polyimines, gelatines or quaternary polymers. It should be assumed that one or more of these nitrogen-containing entities can function at least partially as a mordant.
A wide variety of the vinyl pyrrolidone polymers and copolymers of vinyl pyrrolidone with copolymerizable monomers such as vinyl acetate, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, methyl acrylamide, methyl methacrylamide and vinyl chloride are commercially available and/or are disclosed in U.S. Pat. Nos. 4,741,969; 4,503,111; 4,555,437 and 4,578,285 and PCT application 92-09,440. The concentration of the vinyl pyrrolidone polymer in the ink-receptive layer is subject to some variation. It is used in sufficient concentration to absorb or mordant the printing ink in the layer. A useful concentration is generally in the range of about 15 to about 50 percent by weight based on the total dry weight of the layer, although concentrations somewhat in excess of about 50 weight percent and concentrations somewhat below about 15 weight percent may be used in the practice of the invention.
JP Patent Application 63-307,979 discloses a coating for ink-jet printing containing a hydrophilic soluble copolymer of vinylimidazole, vinylpyrrolidone and vinylbenzylsulfonic acid (60:30:10).
Despite polyvinylpyrrolidone derivatives work as good mordants with the majority of dyes used in ink formulations, they have low ability to fix other components (such as alkylene glycoles, low molecular weight polyoxyethylene compounds) that cause the bleeding phenomen. Hence, there is still a need for improved ink receptors that have minimum post printed drop sweating, still maintaining a good glossiness.
The present invention refers to an ink jet receiving sheet which comprises a support and at least one ink receiving layer comprising a binder selected from the group consisting of gelatin and gelatin derivatives, characterized in that said at least one ink receiving layer comprises at least a copolymer consisting of at least one N-vinylpyrrolidone monomer and at least one second monomer selected from the group of N-vinylcaprolactam monomer and N-vinylpiperidone monomer, to improve post printed drop sweating in the resulting image, still maintaining a good glossiness.
The ink jet receiving sheet of the invention comprises a support and at least one ink receiving layer comprising a binder selected from the group consisting of gelatin and gelatin derivatives. Any gelatin made from animal collagen can be used, but gelatin made from pig skin, cow skin or cow bone collagen is preferable. The kind of gelatin is not specifically limited, but lime-processed gelatin, acid processed gelatin, amino group inactivating gelatin (such as acetylated gelatin, phthaloylated gelatin, malenoylated gelatin, benzoylated gelatin, succinoylated gelatin, methyl urea gelatin, phenylcarbamoylated gelatin, and carboxy modified gelatin), or gelatin derivatives (for example, gelatin derivatives disclosed in JP Patents 38-4854/1962, 39-5514/1964, 40-12237/1965, 42-26345/1967 and 2-13595/1990, U.S. Pat. Nos. 2,525,753, 2,594,293, 2,614,928, 2,763,639, 3,118,766, 3,132,945, 3,186,846 and 3,312,553 and GB Patents 861,414 and 103,189) can be used singly or in combination.
The gelatin binder ordinarily makes up from 30 to 90 weight % and preferably 50 to 80 weight % based on the solid content of the at least one ink receiving layer compositions. Preferably, the ink receiving layers totally comprise a binder amount of from 1 to 20 g/m2, and more preferably from 2 to 10 g/m2.
The at least one receiving layer comprises at least a copolymer consisting in at least one N-vinylpyrrolidone monomer and at least one second monomer selected from the group of N-vinylcaprolactam monomer and N-vinylpiperidone monomer. Useful N-vinylcaprolactam monomers (the term generically including N-vinylcaprolactam and its derivatives that are polymerizable, with non-limiting examples provided herein) and N-vinylpiperidone monomers (the term generically including N-vinylpiperidone and its derivatives that are polymerizable, with non-limiting examples provided herein) also include monomers having substituent groups on an N-vinylcaprolactam or an N-vinylpiperidone nucleous. Useful N-vinylcaprolactam and N-vinylpiperidone monomers contained in the ink receiving layer(s) are those protected in the 3-position, as disclosed in U.S. Pat. No. 5,955,606. The monomers can be prepared by reacting vinylcaprolactam or vinylpiperidone with a strong base at low temperatures to give an enolate and introducing a protecting group into the 3-position of vinylcaprolactam or vinylpiperidone. Examples of suitable N-vinylcaprolactam or N-vinylpiperidone monomers, but not limited to, are N-vinyl-5-piperidone, N-vinyl-4-methylpiperidone, N-vinyl-4-propylpiperidone, N-vinyl-4-butylpiperidone, N-vinyl-6-butylpiperidone, N-vinylcaprolactam, N-vinyl-4-methylcaprolactam, N-vinyl-6-methylcaprolactam, N-vinyl-6-propylcaprolactam and N-vinyl-7-butylcaprolactam. The strong base may be exemplified by t-butyllithium, sodium hydrate and n-butyllithium. This monomer preparation is carried out in an solvent, examples include n-pentane, n-hexane, n-heptane, cyclohexane, ethylether and tetrahydrofuran. As a protecting group source, t-butylchloroformate, isobutylchloroformate, di(t-butyl)dicarbonate, methanesulfonylchloride, methanesulfonic anhydride, tetrahydropyran, 2-chlorotetrahydrofuran, trimethylsilylchloride, 4-methoxybenzylchloride, 4-nitrobenzylchloride, diethylisopropylsilylchloride and t-dimethylsilylchloride can be used.
Useful N-vinylpyrrolidone monomers also include monomers having substituent groups on an N-vinylpyrrolidone nucleus. N-vinylpyrrolidone monomers contained in the copolymer used in the present invention are available as commercial chemicals from a number of suppliers. Examples of suitable N-vinylpirrolidone monomers, but not limited thereto, are N-vinylpyrrolidone, N-vinyl-4-butylpyrrolidone, N-vinyl-4-propylpyrrolidone, N-vinyl-4-ethylpyrrolidone, N-vinyl-4-methylpyrrolidone, N-vinyl-4-methyl-5-ethylpyrrolidone, N-vinyl-4-methyl-5-propylpyrrolidone, N-vinyl-4,5-dimethylpyrrolidone, N-vinyl-5-methyl-5-ethylpyrrolidone, N-vinyl-5,5-dimethylpyrrolidone, N-vinyl-5-propylpyrrolidone, N-vinyl-5-butylpyrrolidone, N-vinyl-5-methylpyrrolidone, N-vinyl-3-methylpyrrolidone, N-vinyl-3-ethylpyrrolidone, N-vinyl-3,4,5-trimethylpyrrolidone and N-vinyl-3,4,5-trimethyl-3-ethylpyrrolidone. Of these several compounds, N-vinylpyrrolidone is most preferred.
The monomers can be easily polymerized in ordinary radical polymerization techniques using radical polymerization initiators. By using the above-mentioned monomers, copolymers which have an appropriate molar ratio in monomers can be prepared. These are polymerized in bulk polymerization or in a solution polymerization. For the solvent for polymerization, cyclohexanone, methylethylketone, benzene, toluene, dioxane, dimethylformamide alone or combinations thereof may be used. Usually, the polymerization is carried out in the presence of a polymerization initiator, such as benzoylperoxide, 2,2xe2x80x2-azobisisobutyronitrile (AIBN), acetyl peroxide, lauryl peroxide, or t-butylperacetate.
Preferably, the N-vinylcaprolactam and N-vinylpiperidone monomers contained in the copolymer used in the present invention are incorporated by polymerization in proportions of from 10 to 90%, more preferably from 20 to 80%, most preferably from 30 to 70%, based on the molecular weight of the total copolymer.
The ink-jet receiving sheet of the present invention totally comprises an amount of the above-described copolymer in the range from about 0.1 to about 10 g/m2, preferably from about 0.2 to about 5.0 g/m2.
The ink receiving layer(s) may also contain a glossiness improving agent represented by monosaccharides and/or oligosaccharides and/or polysaccharides having a recurring unit comprising five or six carbon atoms. Said saccharides can be hydrogenated or non-hydrogenated. Preferred recurring units include, for example, glucose, xylose, mannose, arabinose, galactose, sorbose, fructose, fucose, adonitol, arbitol, inositol, xylitol, dulcitol, iditol, lactitol, mannitol, sorbitol, and the like. The average molecular weight of said saccharides ranges from 1,000 to 500,000, preferably from 1,000 to 30,000.
Hydrogenated and non-hydrogenated saccharides useful in the present invention are commercially available, for example, under the trade designation Polysorb(trademark) or Glucidex(trademark), from Roquette, Lille, France. The preparation of hydrogenated and non-hydrogenated saccharides usually starts from natural products (like starch, agar, tragacanth gum, xanthan gum, guar gum, and the like) by means of enzymatic processes (to reduce the average molecular weight) and of reducing processes (to saturate the molecule, in case of hydrogenated saccharides).
The above-described glossiness improving agents ordinarily make up to 30 weight % and preferably up to 20 weight % based on the solid content of the ink receiving layer compositions. Preferably, the resulting ink receiving layers totally comprise a glossiness improving agent amount from 0.1 to 5 g/m2, preferably from 0.5 to 3 g/m2.
The ink receiving layer(s) may also contain an agent to reduce the print-image drying time. Image drying time, the period the ink is moist after it is ejected onto the print medium, is an important characteristic because, generally, a shorter drying time results in sharper images and allows faster print speeds. The longer an ink dot takes to dry, the greater the chances that the dot will smear, will bleed into an adjacent color ink or will wick into the fibers of the print media. The drying time reducing agent used in the present invention preferably is a water-soluble cationic polymer as those described in EP Patent Application 830,952. Most preferably, the drying time reducing agent is selected from the group consisting of cation modified polyvinyl alcohol and cation modified polyvinyl pyrrolidone compounds. The cation modified polyvinyl alcohols refer to a copolymer of a vinyl alcohol and a monomer containing a cationic group, and examples thereof are described in JP-A 62-138280. The cation modified polyvinyl pyrrolidone compounds refer to a copolymer of vinyl pyrrolidone and a monomer containing a cationic group. Examples of the monomer containing a cationic group include a vinylimidazole in a quaternary salt form, dialkylaminoethylmethacrylate in a quaternary salt form and methacrylamidotrialkylammonium.
The drying time reducing agent is added in an amount of from 5 to 80%, preferably from 10 to 50% by weight respect to the total vinylic polymers of the layer.
The support used in the ink jet receiving sheet of the invention includes any conventional support for ink jet receiving sheet. A transparent or opaque support can be used according to the final use of the ink jet receiving sheet. Useful examples of transparent support include films of polyester resins, cellulose acetate resins, acryl resins, polycarbonate resins, polyvinyl chloride resins, poly(vinylacetal) resins, polyether resins, polysulfonamide resins, polyamide resins, polyimide resins, cellophane or celluloid and a glass plate. The thickness of the transparent support is preferably from 10 to 200 xcexcm. Useful examples of opaque support include paper, coat paper, synthetic paper, resin-covered paper, and pigment-containing opaque films, but synthetic paper, a resin-covered paper or various films are preferable in view of glossiness or smoothness, and resin-covered paper or polyester film are preferable in view of touchiness or luxuriousness.
The base paper constituting the resin-covered paper useful in the invention is not specifically limited, and any conventional paper can be used, but a smooth paper used as a conventional photographic support is preferable. The pulp used for the preparation of the base paper, singly or in admixture, is constituted by natural pulp, reproduction pulp, chemical pulp such as hardwood bleached kraft pulp, softwood bleached kraft pulp, high yield pulps such as undwood pulp or thermomechanical pulp, recycled pulps and non-wood pulps such as cotton pulp or synthetic pulp. These base papers may contain additives usually employed in paper manufacture such as sizing agents, binders, fixing agents, yield-improving agents, cationated agents, paper stiffness enhancing agents, reinforcing agents, fillers, anti-static agents, fluorescent brightening agents or dyes. A surface sizing agent, a surface reinforcing agent, a fluorescent agent, an antistatic agent and an anchoring agent may be coated on the surface of the material.
The thickness of the base paper is not specifically limited, but is preferably from 10 to 200 xcexcm. A base paper having a smooth surface is preferable, which is obtained by applying a pressure to or calendering the paper during or after papering. The weight of the base paper is preferably from 30 to 250 g/m2. The resin used in the manufacturing of resin-covered paper is preferably a polyolefin resin or a resin capable of being hardened with an electron beam. The polyolefin resin includes an olefin homopolymer such as a low density polyethylene, a high density polyethylene, polypropylene or polypentene, an olefin copolymer such as ethylene-propylene copolymer or their mixture, each having various densities or melt viscosity indexes (melt index). These resins can be used singly or in combination.
The resin for the resin-covered paper preferably contains various additives, for example, white pigments such as titanium oxide, zinc oxide, talc or calcium carbonate, a fatty acid amide such as stearic acid amide or arachidic acid amide, a fatty acid metal salt such as zinc stearate, calcium stearate, aluminum stearate or magnesium stearate, an antioxidant such as Irganox(trademark) 1010 or Irganox(trademark) 1076, blue pigments or dyes such as cobalt blue, ultramarine, or phthalocyanine blue, magenta pigments or dyes such as cobalt violet, fast violet or manganese violet, a brightening agent and a UV absorber. These additives can be suitably used in combination.
The resin-covered paper, which is the support preferably used in the present invention, is manufactured by a so-called extrusion method, casting a thermally fused resin (for example, fused polyolefin) on the moving paper, whereby both surfaces of the paper are covered with the resin. When the paper is covered with a resin capable of being hardened with electron beam irradiation, the resin is coated with a conventional coater such as a gravure coater or a blade coater and then is irradiated with electron beam to harden the coated resin. Before the paper is coated with a resin, the surface of the paper is preferably subjected to activation treatment such as corona discharge treatment or flame treatment. The surface of the support on the ink receiving layer side is glossy or matted depending upon its usage, but glossy surface is preferable. The back side of the support is not necessarily covered with a resin, but is preferably covered with a resin to prevent curling. The back surface of a support is ordinarily non-glossy, but the back surface or both surfaces of the support are optionally subjected to activation treatment such as corona discharge treatment or flame treatment. The thickness of a covered resin is not specifically limited, but is ordinarily from 5 to 50 xcexcm.
A subbing layer (also called primer layer) may be provided to improve the adhesion between the film support and the ink receiving layer(s). Useful subbing layers for this purpose are widely known in the photographic art and include, for example, polymers of vinylidene chloride such as vinylidene chloride/acrylonitrile/acrylic acid or vinylidene chloride/methyl acrylate/itaconic acid terpolymers, gelatin, gelatin derivatives, caseine, caseine derivatives.
In addition to the above mentioned ingredients, the ink receiving layer(s) can comprise several adjuvants dispersed therein. Useful adjuvants are represented by fillers, surfactants, mordants, matting agents, hardeners, plasticizers, and the like.
Inorganic and organic particles can be used as fillers. Useful examples of fillers are represented by silica (colloidal silica), alumina or alumina hydrate (aluminazol, colloidal alumina, cation aluminum oxide or its hydrate and pseudo-boehmite), a surface-processed cation colloidal silica, aluminum silicate, magnesium silicate, magnesium carbonate, titanium dioxide, zinc oxide, calcium carbonate, kaoline, talc, clay, zinc carbonate, satin white, diatomaceous earth, synthetic amorphous silica, aluminum hydroxide, lithopone, zeolite, magnesium hydroxide and synthetic mica. Of these inorganic pigments, porous inorganic pigments are preferable such as porous synthetic silica, porous calcium carbonate and porous alumina.
Useful examples of organic fillers are represented by polystyrene, polymethacrylate, polymethylmethacrylate, elastomers, ethylene-vinyl acetate copolymers, polyesters, polyester copolymers, polyacrylates, polyvinylethers, polyamides, polyolefines, polysilicones, guanamine resins, polytetrafluoroethylene, elastomeric styrenebutadiene rubber (SBR), urea resins, urea-formalin resins. Such organic fillers may by used in combination, and/or in place of the above-mentioned inorganic fillers.
The above mentioned fillers are added to the ink receiving layer(s) in an amount of from 0.1 to 5 g/m2, preferably from 0.2 to 3 g/m2, most preferably from 0.3 to 1 g/m2.
Preferred examples of surfactants include anionic surfactants, amphoteric surfactants, cationic surfactants, and nonionic surfactants.
Examples of anionic surfactants include alkylsulfocarboxylates, xcex1-olefin sulfonates, polyoxyethylene alkyl ether acetates, N-acyl amino acids and the salts thereof, N-acyl methyltaurine salts, alkylsulfates, polyoxyalkylether sulfates, polyoxyalkylether phosphates, rosin soap, castor oil sulfate, lauryl alcohol sulfate, alkylphenol phosphates, alkylphosphates, alkylallylsulfonates, diethylsulfosuccinate, diethylhexylsulfosuccinate, and dioctylsulfosuccinate.
Examples of cationic surfactants include 2-vinylpyridine derivatives and poly-4-vinylpyridine derivatives.
Examples of amphoteric surfactants include lauryl dimethyl aminoacetic acid betaine, 2-alkyl-N-carboxymethyl-N-hydroxyethyl imidazolinium betaine, propyldimethylaminoacetic acid betaine, polyoctylpolyaminoethyl glycine, and imidazoline derivatives.
Useful examples of non-ionic surfactants include non-ionic fluorinated surfactants and non-ionic hydrocarbon surfactants. Useful examples of non-ionic hydrocarbon surfactants include ethers, such as polyoxyethylene nonyl phenyl ethers, polyoxyethylene octyl phenyl ethers, polyoxyethylene dodecyl phenyl ethers, polyoxyethylene alkyl allyl ethers, polyoxyethylene oleyl ethers, polyoxyethylene lauryl ethers, polyoxyethylene alkyl ethers, polyoxyalkylene alkyl ethers; esters, such as polyoxyethylene oleate, polyoxyethylene distearate, sorbitan laurate, sorbitan monostearate, sorbitan monooleate, sorbitan sesquioleate, polyoxyethylene monooleate, and polyoxyethylene stearate; and glycol surfactants. Specific examples of non-ionic surfactants include octylphenoxy polyethoxy ethanols, such as Triton(trademark) X-100, X-114, and X-405, available from Union Carbide Co., Danbury, Conn.; acetylenic diols such as 2,4,7,9-tetramethyl-5-decyl-4,7-diol and the like, such as Surfynol(trademark) GA and Surfynol(trademark) CT-136, available from Air Products and Chemicals Co., Allentown, Pa., trimethyl nonylpolyethylene-glycol ethers, such as Tergitol(trademark) TMN-10 (containing 10 oxyethylene units, believed to be of formula C12H25O(C2H4O)5H), available from Union Carbide Co., Danbury, Conn.; non-ionic esters of ethylene oxide, such as Merpol(trademark) SH (believed to be of formula CH3(CH2)12(OC2H4)8OH), available from E. I. Du Pont de Nemours and Co., Wilmington, Del.; non-ionic esters of ethylene oxide and propylene oxide, such as Merpol(trademark) LFH (believed to be of formula CH3(CH2)n(OC2H4)8(OC3H6)8OH, where n is an integer from about 12 to about 16) available from E. I. Du Pont de Nemours and Co., Wilmington, Del., and the like, as well as mixtures thereof. Non-limiting examples of non-ionic fluorinated surfactants include linear perfluorinated polyethoxylated alcohols (e.g., Zonyl(trademark) FSN, Zonyl(trademark) FSN-100, Zonyl(trademark) FSO, and Zonyl(trademark) FSO-100 available from DuPont Specialty Chemicals, Wilmington, Del.), fluorinated alkyl polyoxyethylene ethanols (e.g., Fluorad(trademark) FC-170C available from 3M, St. Paul, Minn.), fluorinated alkyl alkoxylates (e.g., Fluorad(trademark) FC-171 available from 3M, St. Paul, Minn.), fluorinated alkyl esters (e.g., Fluorad(trademark) FC-430, FC-431, and FC-740 available from 3M, St. Paul, Minn.) and fluorine-substituted alkyl esters and perfluoroalkyl carboxylates (for example, the F-tergent series manufactured by Neos Co., Ltd., the Lodyne series manufactured by Ciba-Geigy, the Monflor series manufactured by ICI, the Surfluon series manufactured by Asahi Glass Co., Ltd., and the Unidyne series manufactured by Daikin Industries, Ltd.). Preferred nonionic fluorocarbon surfactants include Zonyl(trademark) FSO, Fluorad(trademark) FC-170C, and Fluorad(trademark) FC-171.
The above mentioned surfactants are added to the ink receiving layers in an amount of from 0.01 to 1.0 g/m2, preferably from 0.05 to 0.50 g/m2.
Additional mordants may be incorporated in the ink-receptive layer of the present invention. Such mordants are represented by cationic compounds, monomeric or polymeric, capable of complexing with the dyes used in the ink compositions. Useful examples of such mordants include quaternary ammonium block copolymers, such as Mirapol A-15 and MirapoL WT available from Miranol Inc., Dayton, N.J., prepared as disclosed in U.S. Pat. No. 4,157,388, Mirapol AZ-1 available from Miranol Inc., prepared as disclosed in U.S. Pat. No. 4,719,282, Mirapol AD-1 available from Miranol Inc., prepared as disclosed in U.S. Pat. No. 4,157,388, Mirapol 9, Mirapol 95, and Mirapol 175 available from Miranol Inc., prepared as disclosed in U.S. Pat. No. 4,719,282, and the like. Other suitable mordants comprise diamino alkanes, ammonium quaternary salts (such as polyvinylbenzyl quaternary ammonium salts disclosed in U.S. Pat. No. 4,794,067) and quaternary acrylic copolymer latexes.
Other suitable mordants are fluoro compounds, such as tetra ammonium fluoride hydrate, 2,2,2-trifluoroethylamine hydrochloride (Aldrich #18,038-6); 2,2,2-trifluoroethyl-toluene sulfonate (Aldrich #17, 782-2); 1-(xcex1,xcex1,xcex1-trifluoro-m-tolyl) piperazine hydrochloride, 4-bromo-xcex1,xcex1,xcex1-trifluoro-o-toluidine hydrochloride, difluorophenylhydrazine hydrochloride, 4-fluorobenzylamine hydrochloride, 4-fluoro-xcex1,xcex1-dimethylphenethylamine hydrochloride, 2-fluoroethylaminehydrochloride, 2-fluoro-1-methyl pyridinium-toluene sulfonate, 4-fluorophenethylamine hydrochloride, fluorophenylhydrazine hydrochloride, 1-(2-fluorophenyl) piperazine monohydrochloride, 1-fluoro pyridinium trifluoromethane sulfonate.
Further mordants are monoammonium compounds as disclosed in, for example, U.S. Pat. No. 5,320,902, including (A) tetradecyl ammonium bromide (Fluka 87582), tetradodecyl ammonium bromide (Fluka 87249), tetrahexadecyl ammonium bromide (Fluka 87298), tetraoctadecyl ammonium bromide (Aldrich 35,873-8), and the like; (B) 2-coco trimethyl ammonium chloride (Arquad C-33, C-33W, C-50 from Akzo Chemie), palmityl trimethyl ammonium chloride (Adogen 444 from Sherex Chemicals), myristyl trimethyl ammonium bromide (Cetrimide BP Triple Crown America), benzyl tetradecyl dimethyl ammonium chloride (Arquad DM 14B-90 from Akzo Chemie), didecyl dimethyl ammonium bromide (Aldrich 29,801-8), dicetyl dimethyl ammonium chloride (Adogen 432CG, Sherex Chemicals), distearyl dimethyl ammonium methyl sulfate (Varisoft 137, 190-100P from Sherex Chemicals, Arosurf TA-100 from Sherex Chemicals), fat acid isopropyl ester dimethyl ammonium methyl sulfate (Rewoquat CR 3099 from Rewo Quimica, Loraquat CR 3099 from Dutton and Reinisch), tallow dimethyl trimethyl propylene diammonium chloride (Tomah Q-D-T from Tomah), and N-cetyl, N-ethyl morpholinium ethosulfate (G-263 from ICI Americas).
Additional mordants are phosphonium compounds, such as, for example, those disclosed in U.S. Pat. No. 5,766,809, including bromomethyl triphenyl phosphonium bromide (Aldrich 26,915-8), 3-hydroxy-2-methyl propyl triphenyl phosphonium bromide (Aldrich 32,507-4), 2-tetraphenyl phosphonium bromide (Aldrich 21,878-2), tetraphenyl phosphonium chloride (Aldrich 21879-0), hexadecyl tributyl phosphonium bromide (Aldrich 27,620-0), and stearyl tributyl phosphonium bromide (Aldrich 29,303-2).
Additional examples of mordants include those disclosed in U.S. Pat. Nos. 5,760,809; 5,457,486; 5,314,747; 5,320,902 and 5,441,795.
The ink receiving layer can be hardened with a hardener in order to improve water resistance or dot reproduction. Examples of hardeners include aldehyde compounds such as formaldehyde and glutaraldehyde, ketone compounds such as diacetyl and chloropentanedion, bis(2-chloroethylurea), 2-hydroxy-4,6-dichloro-1,3,5-triazine, reactive halogen-containing compounds disclosed U.S. Pat. No. 3,288,775, carbamoyl pyridinium compounds in which the pyridine ring carries a sulfo or sulfoalkyl group disclosed in U.S. Pat. Nos. 4,063,952 and 5,529,892, divinylsulfones, reactive olefin-containing compounds disclosed U.S. Pat. No. 3,635,718, N-methylol compounds disclosed U.S. Pat. No. 2,732,316, isocyanates disclosed U.S. Pat. No. 3,103,437, aziridine derivatives disclosed U.S. Pat. Nos. 3,017,280 and 2,983,611, carbodiimides disclosed U.S. Pat. No. 3,100,704, epoxy compounds disclosed U.S. Pat. No. 3,091,537, halogencarboxyaldehydes such as mucochloric acid, dioxane derivatives such as dihydroxy dioxane, and inorganic hardeners such as chromium alum, potash alum and zirconium sulfate. These hardeners can be used singly or in combination. The addition amount of hardener is preferably 0.01 to 10 g, and more preferably 0.1 to 5 g based on 100 g of the binder contained in the ink receiving layer.
The ink receiving layer may contain a matting agent in an amount of 0.005 to 0.1 g/m2 in order to prevent adhesion defects such as blocking. Matting agents can be defined as particles of inorganic or organic materials capable of being discontinuously dispersed in a hydrophilic organic colloid. The inorganic matting agents include oxides such as silicon oxide, titanium oxide, magnesium oxide and aluminum oxide, alkali earth metal salts such as barium sulfate, calcium carbonate, and magnesium sulfate, light-insensitive silver halide particles such as silver chloride and silver bromide (each of which may contain a small amount of iodine), and glass particles. Besides these substances there may be used inorganic matting agents which are disclosed in DE Patent 2,529,321, in GB Patents 760,775 and 1,260,772, U.S. Pat. Nos. 1,201,905, 2,192,241, 3,053,662, 3,062,649, 3,257,296, 3,322,555, 3,353,958, 3,370,951, 3,411,907, 3,437,484; 3,523,022, 3,615,554, 3,635,714, 3,769,020, 4,021,245 and 4,029,504. The organic matting agents include starch, cellulose esters such as cellulose acetate propionate, cellulose ethers such as ethyl cellulose, and synthetic resins. The synthetic resins are water insoluble or sparingly soluble polymers which include a polymer of an alkyl(meth)acrylate, an alkoxyalkyl-(meth)acrylate, a glycidyl(meth)acrylate, a (meth)acrylamide, a vinyl ester such as vinyl acetate and acrylonitrile, an olefin such as ethylene or styrene and a copolymer of the above described monomers with other monomers such as acrylic acid, methacrylic acid, xcex1,xcex2-unsaturated dicarboxylic acid, hydroxyalkyl(meth)acrylate, sulfoalkyl(meth)acrylate and styrene sulfonic acid. Further, a benzoguanamin-formaldehyde resin, an epoxy resin, nylon, polycarbonates, phenol resins, polyvinyl carbazol or polyvinylidene chloride can be used. Besides the above there are used organic matting agents which are disclosed in GB Patent 1,055,713, U.S. Pat. Nos. 1,939,213, 2,221,873, 2,268,662, 2,322,037, 2,376,005, 2,391,181, 2,701,245, 2,992,101, 3,079,257, 3,262,782, 3,443,946, 3,516,832, 3,539,344,554, 3,591,379, 3,754,924 and 3,767,448 and in JP Patents 49-106821/1974 and 57-14835/1982. These matting agents may be used alone or in combination.
The ink-receiving layer of the present invention can also comprise a plasticizer such as ethylene glycol, diethylene glycol, propylene glycol, polyethylene glycol, glycerol monomethylether, glycerol monochlorohydrin, ethylene carbonate, propylene carbonate, tetrachlorophthalic anhydride, tetrabromophthalic anhydride, urea phosphate, triphenylphosphate, glycerol monostearate, propylene glycol monostearate, tetramethylene sulfone, N-methyl-2-pyrrolidone, N-vinyl-2-pyrrolidone, and polymer latices with a low Tg-value such as polyethylacrylate, polymethylacrylate, etc.
The ink receiving layer can comprise biocides. Examples of suitable biocides include (A) nonionic biocides, such as 2-bromo-4xe2x80x2-hydroxyacetophenone (Busan 90 available from Buckman Laboratories); 3,5-dimethyl tetrahydro-2H-1,3,5-thiadiazine-2-thione (Slime-Trol RX-28 available from Betz Paper Chem Inc.); a nonionic blend of 5-chloro-2-methyl-4-isothiazoline-3-one, 75% by weight, and 2-methyl-4-isothiazolin-3-one, 25% by weight (available as Amerstat 250 from Drew Industrial Division; Nalcon 7647 from Nalco Chemical Company; and Kathon LX from Rohm and Haas Company); and the like, as well as mixtures thereof; (B) anionic biocides, such as potassium N-hydroxymethyl-N-methyl-dithiocarbamate (available as Busan 40 from Buckman Laboratories Inc.); an anionic blend of methylene bis-thiocyanate, 33% by weight, sodium dimethyl-dithiocarbamate, 33% by weight, and sodium ethylene bisdithiocarbamate, 33% by weight, (available as Amerstat 282 from Drew Industrial Division; AMA-131 from Vinings Chemical Company); sodium dichlorophene (G-4-40 available from Givaudan Corporation); and the like, as well as mixtures thereof; (C) cationic biocides, such as cationic poly(oxyethylene (dimethylamino)ethylene (dimethylamino) ethylene dichloride) (Busan 77 available from Buckman Laboratories Inc.); a cationic blend of bis(trichloromethyl) sulfone and a quaternary ammonium chloride (available as Slime-Trol RX-36 DPB865 from Betz Paper Chem. Inc.); and the like, as well as mixtures thereof. The biocide can be present in any effective amount; typically, the biocide is present in an amount of from 0.1 to 3 percent by weight of the coating, although the amount can be outside this range.
The ink receiving layer of the invention may further contain various conventional additives such as colorants, colored pigments, pigment dispersants, lubricants, permeating agents, fixing agents for ink dyes, UV absorbers, anti-oxidants, dispersing agents, anti-foaming agents, leveling agents, fluidity improving agents, antiseptic agents, brightening agents, viscosity stabilizing and/or enhancing agents, pH adjusting agents, anti-mildew agents, anti-fungal agents, agents for moisture-proofing, agents for increasing the paper stiffness and anti-static agents.
The above-mentioned various additives can be added ordinarily in a range of 0 to 10 weight % based on the solid content of the ink receiving layer composition.
As a coating method of an ink receiving layer coating solution, any conventional coating method (for example, a curtain method, an extrusion method, an air-knife method, a slide coating, a roll coating method, reverse roll coating, solvent extrusion, dip coating processes and a rod bar coating method) can be used.
The ink-receiving layer of the present invention is preferably coated on one side of the support as a plurality of at least two distinct layers, coated from different coating solutions. Most preferably, the ink-receiving layer of the present invention is coated on one side of the support as a plurality of three distinct layers, coated from different coating solutions. When the ink jet receiving sheet of the present invention contains at least two ink receiving layers coated on one side of the support, at least one of said ink receiving layers contains the copolymer consisting of at least one N-vinylpyrrolidone monomer or derivatives thereof and at least one monomer selected within the group of N-vinylcaprolactam, N-vinylpiperidone monomer or their derivatives. Preferably, all said ink receiving layers contain said copolymer, in the same or in different amounts. The ink jet receiving layer of the present invention can also contain at least an ink receiving layer coated on both sides of the support; in that case, at least one of said receiving layers contains the copolymer cited above. When preparing an ink-jet receiving sheet by coating two or more ink-receing layers onto a support, it is possible to prepare an ink-receiving sheet with excellent properties, especially with respect to glossiness and post printed drop sweating after stressed ageing.
The ink jet receiving sheet of the invention has a surface pH value lower than 5.0, preferably in the range from 3.5 to 4.5. At surface pH values lower than 5 good glossiness, defined as the quantity of reflected light measured at a predetermined angle (generally at 20xc2x0, 60xc2x0 or 85xc2x0) with respect to the direction of the incident light and expressed in percentage, can be noted.

Receiving sheet for ink-jet printing comprising a copolymer


A lighting fixture includes a modular lamp assembly and a lighting fixture comprising a mounting plate and lamp holder affixed to the mounting plate. The lamp holder has flexible retaining members which extend away from the mounting plate. The retaining members have respective securing means to secure the modular lamp assembly at a fixed angle relative to the mounting plate. A flange on the lamp holder guides an electrical cord. This arrangement allows safe and convenient replacement of the modular lamp assembly. A skirt affixed to the mounting plate protects the lamp holder and modular lamp assembly and provides an aesthetically pleasing appearance. The lighting fixture may be readily mounting to hardscape or wooden construction. A strain relief for the electrical cord in the lighting fixture includes an elastic plug and stopper molded to the cord as a single body, and fits into a hole in the flange.

Lighting fixtures for mounting on retaining walls or under steps, decks or railings are known in the art. With many of these fixtures, removal and replacement of the bulbs can be difficult, requiring that bulb covers or the fixtures themselves be removed so that the bulbs can be seen and accessed. Further, the process of removing the bulbs presents a risk of burns or electrical shocks. Water drainage or condensation may penetrate the bulb cover, thereby damaging the electrical components, increasing the risk of electrical shocks or failure of the lamp. Further, many of the known lighting fixtures are arranged to direct light downwards, failing to provide more than narrow fields of illumination. Such fixtures may also produce shadows or hot spots of intense light, which can be aesthetically displeasing.


Systems and methodologies are described that facilitate multiplexing communications from multiple downstream access points to one or more upstream access points. In particular, a concentrator component is provided that can establish a single transport layer connection with an upstream access point along with multiple application layer connections over the single transport layer connection for each of multiple downstream access points and/or related mobile devices. The downstream access points and/or mobile devices can provide identifiers to the concentrator component, which can utilize the identifiers to track communications with the upstream access points. In this regard, the upstream access points can additionally include identifiers received from the concentrator component in subsequent communications to facilitate identifying the appropriate downstream access point and/or mobile device.

1. Field
The following description relates generally to wireless communications, and more particularly to control plane communications with upstream network components and between access points.
2. Background
Wireless communication systems are widely deployed to provide various types of communication content such as, for example, voice, data, and so on. Typical wireless communication systems may be multiple-access systems capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, . . . ). Examples of such multiple-access systems may include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, and the like. Additionally, the systems can conform to specifications such as third generation partnership project (3GPP), 3GPP long term evolution (LTE), ultra mobile broadband (UMB), and/or multi-carrier wireless specifications such as evolution data optimized (EV-DO), one or more revisions thereof, etc.
Generally, wireless multiple-access communication systems may simultaneously support communication for multiple mobile devices. Each mobile device may communicate with one or more access points (e.g., base stations) via transmissions on forward and reverse links. The forward link (or downlink) refers to the communication link from access points to mobile devices, and the reverse link (or uplink) refers to the communication link from mobile devices to access points. Further, communications between mobile devices and access points may be established via single-input single-output (SISO) systems, multiple-input single-output (MISO) systems, multiple-input multiple-output (MIMO) systems, and so forth. In addition, mobile devices can communicate with other mobile devices in peer-to-peer wireless network configurations.
Access points can communicate with additional upstream wireless network components to facilitate providing wireless network access to the mobile devices. In some configurations, the access points can establish connection with a mobility management entity (MME) to provide session and mobility management in the wireless network. MMEs can further communicate with additional upstream network components to authenticate/authorize the mobile devices to communicate over the network and/or to facilitate transmitting/receiving data over the network.
Small scale access points, such as femtocell access points, picocell access points, relay nodes, etc., have been introduced to conventional wireless networks allowing heterogeneous unregulated deployment of new access points. These small scale access points similarly establish connection with MMEs to provide session and mobility management in the wireless networks. MMEs, however, can be limited in the number of supportable connections, both at the transport and application layers. Similarly, some access points can support other small scale access points, providing MME access thereto, and similarly can have limits on the number of concurrently supportable connections especially, for example, where the supporting access point is a picocell or femtocell access point.

Concentrator for multiplexing access point to wireless network connections


The present invention is directed to a precise power system which utilizes two separate inverters fed by a rectifying power supply from a generator set. During normal operation, the first or critical inverter would feed the critical load(s) and the second or non-critical inverter would assist the electric utility in feeding the non-critical load(s). During utility grid failure, the second inverter is disconnected from the power supply so that the entire output of the generator set is available to the critical load. During generator set failure, the utility grid powers the second inverter to supply power to the first inverter for the critical load(s).

Many devices such as computers cannot tolerate even short interruptions in the supply of electricity or even slight deviations from rigid quality specifications for power. In addition, many manufacturing processes such as semiconductor fabrication have similar requirements. Power interruptions or poor quality power can result in loss of data, computers going off-line, damage to hardware, loss of in-process product, delayed product deliveries and other problems.
One solution has been to use generator sets that provide precise power to the critical loads and only to the critical loads. Thus, the power that has to be precise is isolated from utility problems such as switching transients, and lightning strikes as well as from in-house problems such as power surges or voltage dips caused by motor starting inrush. Generally this has meant the installation of what has been referred to as an "n+1" system. In other words, one more generator set than is necessary to meet the maximum load is installed. Thus, if a generator set fails, the remaining generator set(s) can still handle the load.
A major deficiency in "n+1" systems is the increase in capital cost due to the redundant generator set. Thus, if two generator sets can handle the load, three must be installed for roughly a 50% cost increase. A worse case occurs if one generator set can handle the load. Then the addition of a redundant generator set essentially doubles the cost of the system.
A second deficiency of an "n+1" system is that the generator sets do not operate at their full rating as they must always be prepared to increase power to handle the required load when a generator set fails. Indeed, if one generator set can handle the load and two are installed, the two generator sets must operate at no more than half of their rating if they are to be able to pick up the full load when a generator set fails. With conventional single shaft, gas turbine-driven generator sets (turbogenerators), this has meant a dramatic decrease in fuel efficiency. Correspondingly, small turbogenerators or microturbines must operate at much higher speeds than is optimum for efficiency if they are going to be able to assume the increased load when a generator set fails.
U.S. Pat. No. 4,059,770, issued on Nov. 22, 1977 to Robin Mackay entitled "Uninterruptible Electric Power Supply" describes a concept which uses a prime mover to drive two synchronous generators simultaneously through an overrunning clutch, and is incorporated herein by reference. The first or critical generator would be connected to the critical load and provide precise power to it while always matching exactly the demand of the critical load. The second or non-critical generator would be paralleled with the utility and assist the utility in providing power to the non-critical loads. It would provide a varying amount of power to the non-critical loads such that the total load of both generators would be fixed and match the rating of the prime mover. Thus, if the critical generator experienced a rapid change in load through a change in the load on the critical buss or a failure of a paralleled generator set, the prime mover would not see a step load. It would continue to drive the generators at a fixed speed maintaining a constant frequency.
Correspondingly, if the prime mover in the concept of U.S. Pat. No. 4,059,770 failed, the generator that is connected to the utility grid would instantly become a motor and drive the generator that is feeding the critical loads. The prime mover would instantly disconnect itself from the generators through the action of an overrunning clutch.
There are several advantages to this system over an "n+1" system. First, the redundant generator set is eliminated reducing first cost. Second, the prime mover operates at its full rating which increases its efficiency. Third, because the generator set operates at its full rating, more power is generated reducing the capital cost per kWh element in the cost of producing electricity. Fourth, because the output of the prime mover does not change as the critical loads change, there is no problem with positive or negative step loads.
While the concept of U.S. Pat. No. 4,059,770 has these advantages with respect to turbogenerators generally, small turbogenerators or microturbines present a different problem statement. The vast majority of microturbines in the field today consist of modest sized gas turbines that drive generators that operate at the same speed as the gas turbine. These very high-speed generators operate in the range of 96,000 rpm to produce power at very high frequencies, typically 1600 Hz. As this frequency is too high for most applications, a power conditioning system is needed. The generator output is rectified to direct current and then inverted to conventional frequencies such as 50 Hz or 60 Hz.
For precise power using microturbines, an "n+1" system has traditionally been used with the disadvantages discussed above. Although the concept of driving two generators simultaneously, as proposed in U.S. Pat. No. 4,059,770, is theoretically possible, it is totally impractical because of the very high speeds.
An alternate concept more specifically directed to microturbines is described in U.S. Pat. No. 6,031,294, issued on Feb. 29, 2000 to Everett R. Geis, Brian W. Peticolas and Joel B. Wachnov entitled "Turbogenerator/Motor Control System with Ancillary Energy Storage/Discharge" and incorporated herein by reference. In that patent, an alternate source of power such as batteries can be used either to provide additional power to the direct current buss during increasing loads or to absorb power during decreasing loads.
Although technically sound, this concept increases the cost of the system as well as the space required, as the most practical source of additional power is batteries. Batteries are expensive, bulky, and require both regular maintenance and regular replacement. In addition, the gas turbines still operate at reduced load, as there must be margin to handle increasing loads or potential overloads. This impacts the efficiency as well as reducing the total amount of power that the gas turbine could produce thus increasing the capital cost per kWh generated. Most important, in the event of a gas turbine failure or a fuel supply failure, the system would go down as soon as the energy storage device (battery) was exhausted.

Multiple inverter power system with regard to generator failure


A wheel chair system including a pair of levers mounted to each side of an operator seated in the wheelchair, each lever having a handle which the operator can articulate between a position aligned with the levers and a position normal to the levers. The levers are each connected to a planetary gear system and a double ratchet assembly and are movable by the operator forwardly and rearwardly through an arc. Each double ratchet assembly is connected to two chains, one of which is driven when the lever is rotated in one direction and the other of which is driven when the ratchet is rotated in the opposite direction. The handles, levers, ratchets and gears are configured and interconnected such that when the operator moves the handles and levers through a rowing motion, the wheel chair is powered in a forward direction. The gear set can be chosen, and modified, to be compatible with the strength characteristics of the upper body musculature of the operator.

1. Field of the Invention
This invention relates to a wheeled conveyance system, and more particularly to a manually or power driven wheelchair and transmission system for a wheelchair.
2. Description of the Prior Art
Numerous types of wheelchair systems exist. Such systems, however, generally do not take good advantage of the musculature of the human body. The wheelchairs are customarily designed without the capability to readily match the system to the strength or stature of the particular operator or to differing uses.
The most common systems utilize two large hand driven wheels. A problem with such systems, particularly when used outside, is that the operator's hands and arms are in contact with or close to the driving wheels, which wheels are in contact with the ground. This creates an unclean environment about the operator's arms and hands. Use of the wheels also tends to callous the hands of the operator, and requires frictional restraint by the hands for braking. And, such systems place stresses on the operator's arms and hands which result in physical problems such as, for example, carpal tunnel syndrome.
Manually powered wheel chair systems require use of upper body musculature, and typically require use of the operator's arms positioned to the side of the body. This positioning relies heavily on the operator's triceps, and does not take good advantage of additional upper body and arm characteristics. For example, the biceps of the human body are typically more powerful than the triceps. Biceps are more useful when pulling, and triceps are more useful when pushing.
Additionally, the pectoral muscles provide strength, particularly when used together with the biceps. Pectoral muscles, however, do not provide as much aid to the triceps. In most present wheel chair systems the operator pushes forwardly on the upper portion of the wheels, inputting power, but the operator does not input energy on the return of the hands and arms to position for the next push stroke. There are systems marketed by Rock N'Roll Inc. of Texas wherein forward and rearward motion of handlebars on bicycle type structures is inputted as power to a specially configured gear system.
Additionally, present systems are designed for a broad cross section of users, without consideration of the musculature strength of an operator or the modification of that strength over time, for example, as a young operator grows.
It is therefore desirable to provide a manually powered wheel chair system, and a transmission for wheelchairs, which improves upon these and other limitations. It is also desirable to provide such systems which are compatible with power mechanisms.


A backrest mounted item hook and drink holder including an arm member which is extendible from a first recess within a rearward side of a backrest portion of a chair body to hang a purse or other item therefrom and a drink holder rack extendible from a second recess within the rearward side. The drink holder rack also has a pivotable upper portion with a convex exterior side and a central aperture and a pivotable lower tray portion which has a bottom end to support a lowermost end of a bottled drink container thereon while an uppermost end of the bottled drink container is retained within the central aperture. When each of the arm member and the drink holder rack is in the retracted condition, the chair body is stackable atop another chair body.

Various types of holders and supports for storing items on various support structures, such as a handle, a pane of a rolldown vehicle window, an arm of a chair, and a back of chair, such as a beauty salon chair or a church pew, are known in the prior art. However, what is needed and what the present device provides is a chair with a backrest mounted item hook and a backrest mounted drink holder extendible from a retracted condition within a first recess and a second recess, respectively, in a rearward side of the chair during use to an extended condition for use. When the item hook and drink holder are in the retracted condition, the chair is stackable atop another chair.

Chair with backrest mounted item hook and drink holder


This invention generally relates to rescue, firefighting, or paying devices and, more particularly, to a fire hose dispensing device and method. The present invention includes a hose box, fire hose, and a hose box release mechanism. The device and method allow firefighters to release and pay hose without leaving the passenger compartment of a fire truck.

1. Field of the Invention
The invention relates generally to the field of firefighting devices and, more particularly, to a hose dispenser for a fire apparatus such as a fire truck.
2. Description of the Prior Art
Connecting a fire hose between a fire truck and a water hydrant has traditionally been a time consuming and hazardous evolution. With early firefighting devices, a firefighter would typically ride on the rear deck of a moving fire apparatus, such as a truck or wagon, until a fire hydrant was located. The apparatus would stop and the firefighter would jump from the apparatus clutching one end of a folded two and one-half inch diameter hose. After wrapping the hose several times around the hydrant, the firefighter would jump back onto the apparatus. As the apparatus resumed its forward motion toward the fire, the hose in the bed of the apparatus would unroll. The entire process was moderately expedient, provided the firefighter was not injured by fire related hazards, slippery surfaces or adverse weather.
However, due to changes in equipment, coupled with health and safety concerns, the traditional method of paying hose from a fire truck became less efficient. First, both the diameter and length of supply hoses have increased, making the hoses heavier and harder to handle. Second, longer, thicker hoses occupied more space, forcing the hoses to be stacked higher on the fire truck. Lastly, federal and state safety regulations required firefighters, wearing full protective gear, to travel inside of a fire truck's passenger compartment. This combination of changes resulted in the modern method of paying hose. In the modern method, the fire truck is stopped next to an available hydrant. A fully-equipped firefighter jumps out of the fire truck's passenger compartment, runs the length of the truck to the end of the truck bed, leaps up onto the truck's rear deck, physically grabs an end of a hose located at eye level, pulls the hose away from the truck without losing his balance and falling backwards off of the rear deck, jumps from the rear deck to the ground, runs to a fire hydrant, wraps several turns of the hose around the hydrant, runs back to the truck, and steps back up into the truck's passenger compartment. Once the fireman is inside, the truck restarts and continues toward the fire. This modern method is relatively time consuming and tiring for the firefighter, who must do all of these procedures wearing full protective gear. Valuable time is wasted which could be better spent in actually fighting the fire.


A means of enhancing the acoustic attenuation and vibration damping of a material by embedding high characteristic acoustic impedance particles, low characteristic acoustic impedance particles, or both high and low characteristic acoustic impedance particles within the matrix of the material is disclosed. The mass of the resultant material may be very low while retaining excellent acoustic attenuation, vibration damping, and structural characteristics. When particles with mismatched characteristic acoustic impedances are embedded within the matrix of a material that can support shearing loads, propagating acoustic energy that encounters the particles of the instant invention is partially reflected in random directions. That is, the propagating energy is diffused. As the propagation vectors and modes of acoustic energy are effectively randomized, the probability of localized energy absorption and damping is increased. We present acoustic attenuation and vibration damping data for some representative examples of the instant invention and other commercially available materials.

1. Field of the Invention
This invention relates to acoustic attenuation and vibration damping materials, particularly to acoustic attenuation and vibration damping materials intended to be placed between acoustic and/or vibratory energy sources and acoustic and/or vibration protected areas.
2. Description of Related Art
Numerous methods currently exist for the control of acoustic noise and vibration ranging from simple, passive barrier and damping techniques to more sophisticated electronic noise canceling approaches. These methods may target either the noise or vibration source, the transmission path, the receiving site, or any or all of the preceding in combination. The instant invention is of the barrier class and utilizes a composite material composed of a matrix material containing filler particles with high and/or low characteristic acoustic impedances to provide improved sound attenuation, vibration damping, and weight characteristics. By careful selection of matrix material and filler particles, the design engineer can create a composite material with an optimal balance of sound and vibration attenuation, weight, strength, temperature characteristics, and durometer.
Within the field of noise control, absorptive techniques are typically utilized to prevent or reduce air-borne acoustic energy from reaching a receiving site. Similarly, vibration damping techniques are usually applied in close contact with the vibrating structure to prevent or reduce air-borne or structure-borne energy from propagating to the protected area. Both techniques utilize internal damping of impinging acoustic energy as an important means of reducing energy levels and therefore share basic principles. A general review of the art in this area is available from "Material Damping and Slip Damping" by L. E. Goodman (Shock & Vibration Handbook (3rd ed.), Cyril M. Harris (ed.), 1987) and from "Sound-Absorptive Materials" by Ron Moulder (Handbook of Acoustical Measurements and Noise Control (3rd ed.), Cyril M. Harris (ed.), 1991), but a brief overview follows.
Currently available materials capable of absorbing unwanted acoustic energy (i.e., noise) are most effective at frequencies above 500 Hz. Noise attenuation rapidly worsens as lower frequencies are encountered with the result being that few material manufacturers even report attenuation values below 125 Hz.
Most sound absorptive materials, such as foams, felts, etc., are highly porous in structure with the pores intercommunicating throughout the material. The pores may be formed by interconnected solid bubbles, or interstices between small granules, or they may be inherent in naturally porous fibrous materials such as fiberglass. The amplitude of sound waves entering the porous material is reduced through friction between the air molecules and the surfaces of the pores. These materials tend to be light in weight and most effective at shorter wavelengths (i.e., higher frequencies). Unless these porous materials form part of a layered, or constrained, composite with a denser, less porous material, their structural strength is limited.
In order to attenuate lower frequencies, absorptive materials are usually combined with a rigid material with an air space separating the two materials. The amount of low frequency attenuation is directly related to the size of this air space. This approach of combining a sound absorptive material with a rigid material and a separating air space increases both the overall weight and thickness of the resulting sound attenuating structure and therefore may not be feasible in a given application. A significant problem with this approach is the fact that many structures must be load bearing as well as sound absorbing, necessitating the inclusion of solid members between rigid materials. These solid members often provide a very good conduit for acoustic energy, thereby partially defeating the structures' sound attenuating properties.
Another approach embodies the "mass law" which applies to a relatively thin, homogeneous, single layer panel. The mass law states that the loss of energy as it transits a barrier is, over a wide frequency range, a function of the surface density of the barrier material and the frequency in question. In general, this transmission loss increases by 6 dB for each octave increase in frequency and for each doubling of the mass of the material. Thus, increasing the mass of the material through increases in thickness or density can improve the acoustic barrier for all frequencies including those in the lower portion of the spectrum. This gain in transmission loss is at the cost of added barrier weight.
Materials utilized specifically for vibration damping follow many of the same rules as those in the absorptive class but are, as a general rule, optimized for attenuating the lower frequencies. As a result, many of these materials are of higher densities and thicknesses and tend to depend more on the internal damping of energy penetrating the material than upon the "capture" of acoustic energy by way of a porous architecture.

Acoustic attenuation and vibration damping materials

The United States of America as represented by the Secretary of the Navy


A motor including a motor unit (2) has at least one plastics material portion (4). A two-part casing (5) receives at least one electronic circuit card. The casing is formed of two complementary portions (5a, 5b) joining on a plane (P) passing through a diagonal plane of the casing and provided with means (7) to receive the circuit card and complementary fixing means (9, 10, 11). One portion (5a) of the casing is in one piece with the plastics material (4) of the motor unit and the other portion (5b) includes an envelope (8) for a connector for connecting the motor to the remainder of the circuits of the vehicle.

The present invention concerns an electric motor for actuating a functional unit of a motor vehicle. The invention is more particularly concerned with an electric motor of the type including a motor unit having at least one plastics material portion.
Electric motors of this type are used to drive functional units of motor vehicles such as adjustors for seats, windows, etc., for example. Such actuator motors are frequently associated with electronic circuits that supply power to the motors and monitor their operation to improve their safety.
For example, anti-pinching functions have been associated with gear motors for actuating vehicle window closing mechanisms in particular.
The increasing integration of electronic circuits into vehicles is also giving rise to a number of problems, in particular with regard to their location.

Electric motor for actuating a functional unit of a vehicle


Seats and seat covers are provided with selectively attachable and detachable blankets for lap warming of seat occupants. Embodiments include golf cart attachable blanket systems, and portable seating and blanket systems operable configurable between multi-occupant and individual single-occupant modes of use, and/or between compact transport and working multi-occupant positions.

It is known to use blankets during seated participation in outdoor activities to improve the comfort of a participant. For example, golf cart seat blankets are known that have slots for fitting over the armrests of a golf cart that resides at opposite ends of a multi-occupant bench-style seat of the golf cart. However, getting under the blanket requires that the user lift up the blanket from around the arm, making it inconvenient to repeatedly get in and out from under the blanket during play of game. Use of a standard blanket brought from home at various outdoor events is also problematic, as the generic blanket is not secured in any way to the seat, meaning that the blanket can easily fall to the floor and become soiled or lost, or even blow away if left momentarily unattended in a windy outdoor environment.
Accordingly, there remains room for improvement in the field of blanket-aided seating comfort.

Attachable/detachable lap blankets for seat occupants


In general, techniques described are for providing graceful restart procedures for network devices of label switched paths (LSPs) implemented with label stacks. For example, a restarting network device may include a processor coupled to a memory that executes software configured to: receive a path signaling message including a recovery object that defines a reverse path of the LSP from an egress network device of the LSP to the restarting network device, including at least an upstream label and a downstream label associated with the restarting network device; determine, based on the recovery object, the upstream label and the downstream label associated with the restarting network device; and instantiate a control plane state of the restarting network device based on the recovery object.

Routing devices within a network, often referred to as routers, maintain routing information that describes available routes through the network. Routers use routing protocols to exchange and accumulate topology information that describes the network. This allows a router to construct its own routing topology map of the network. Upon receiving an incoming packet, the router examines information within the packet and forwards the packet in accordance with the accumulated topology information.
Packet-based networks utilize label switching protocols for traffic engineering and other purposes. Multi-Protocol Label Switching (MPLS) is a mechanism used to engineer traffic patterns within Internet Protocol (IP) networks according to the routing information maintained by the routers in the network. By utilizing MPLS protocols, such as the Resource Reservation Protocol with Traffic Engineering extensions (RSVP-TE) or Label Distribution Protocol (LDP), label switching routers can forward traffic along a particular path through a network to a destination device, i.e., a Label Switched Path (LSP), using labels prepended to the traffic.
An LSP defines a distinct path through the network to carry MPLS packets from the source device to a destination device. Each router along a LSP allocates a label in association with the destination and propagates the label to the closest upstream router along the path. Routers along the path add (push), remove (pop), or swap the labels and perform other MPLS operations to forward the MPLS packets along the established path.

Graceful restart procedures for label switched paths with label stacks


An ink station assembly is for a can decorator machine structured to decorate a plurality of cans. The ink station assembly includes a first oscillator roll and a second oscillator roll each having a longitudinal axis and being structured to oscillate back and forth along the longitudinal axis, a printing plate cylinder including a printing plate, and only one single form roll cooperating with the printing plate cylinder to apply a supply of ink to the printing plate, the single form roll cooperating with the first oscillator roll and the second oscillator roll.

Field
The disclosed concept relates generally to machinery and, more particularly, to can decorator machines and methods for decorating cans used in the food and beverage packaging industries. The disclosed concept also relates to ink station assemblies for can decorator machines.
Background Information
High speed continuous motion machines for decorating cans, commonly referred to as can decorator machines or simply can decorators, are generally well known.
FIG. 1 shows a can decorator 2 of the type disclosed, for example, in commonly assigned U.S. Pat. No. 5,337,659, which is incorporated herein by reference. The can decorator 2 includes an infeed conveyor 15, which receives cans 16 from a can supply (not shown) and directs them to arcuate cradles or pockets 17 along the periphery of spaced parallel rings secured to a pocket wheel 12. The pocket wheel 12 is fixedly secured to a continuously rotating mandrel carrier wheel 18, which in turn is keyed to a continuously rotating horizontal drive shaft 19. Horizontal spindles or mandrels (not shown), each being pivotable about its own axis, are mounted to the mandrel carrier wheel 18 adjacent its periphery. Downstream from the infeed conveyor 15, each spindle or mandrel is in closely spaced axial alignment with an individual pocket 17, and undecorated cans 16 are transferred from the pockets 17 to the mandrels by wiping against a stationary arm 42, which is angled inwardly in the downstream direction so as to function as a cam that drives the can 16 toward the corresponding mandrel. Suction applied through an axial passage of the mandrel draws the can 16 to a final seated position on the mandrel.
While mounted on the mandrels, the cans 16 are decorated by being brought into engagement with a blanket (e.g., without limitation, a replaceable adhesive-backed piece of rubber) that is adhered to a blanket segment 21 of the multicolor printing unit indicated generally by reference numeral 22. Thereafter, and while still mounted on the mandrels, the outside of each decorated can 16 is coated with a protective film of varnish applied by engagement with the periphery of an applicating roll (not shown) rotating on a shaft 23 in the overvarnish unit indicated generally by reference numeral 24. Cans 16 with decorations and protective coatings thereon are then transferred from the mandrels to suction cups (not shown) mounted adjacent the periphery of a transfer wheel (not shown) rotating on a shaft 28 of a transfer unit 27. From the transfer unit 27 the cans 16 are deposited on generally horizontal pins 29 carried by a chain-type output conveyor 30, which carries the cans 16 through a curing oven (not shown).
While moving toward engagement with an undecorated can 16, the blanket engages a plurality of printing cylinders 31, each of which is associated with an individual ink station assembly 32 (six ink station assemblies 32 are shown in the example of FIG. 1). Each ink station assembly 32 includes a plurality of form rolls 33, 34 and other rolls (e.g., without limitation, roll 35 shown in simplified form in hidden line drawing in FIG. 1; see also FIG. 5) that produce a controlled film of ink, which is applied to a printing cylinder 31. Typically, each assembly 32 provides a different color ink and each printing cylinder 31 applies a different image segment to the blanket. All of these image segments combine to produce the same main image. This main image is then transferred to undecorated cans 16.
When decorating metal, it is important to supply the printing cylinder 31 with as consistent of an ink film thickness, as possible, in order for the printing plate to impart a clear and consistent image to the printing blanket 21 and ultimately to the final printed substrate (e.g., can 16). Inconsistencies in the ink film can result in variable color density across the printed image, as well as present the possibility of "starvation ghosting" of the image, wherein a lighter duplicate version or copy of the image is undesirably applied to the can 16 in addition to the main image. Prior proposals for solving the problem of ink film consistency and related issues such as starvation ghosting, have included such approaches as adding more form rolls, changing form roll diameters, each of the form rolls having a different diameter all of which are less than the diameter of the printing cylinder, adding a number of rider rolls and/or oscillating rider rolls on one or more of the form rolls, and/or variation of the axial cycle rates of the oscillating roll(s).
There is, therefore, room for improvement in can decorating machines and methods, and in ink station assemblies.

This patent is subject to a terminal disclaimer.

Can decorator machine, ink station assembly therefor, and can decorating method employing same


A method for remotely building electronic files, and a system and product for performing the method. The method includes determining if a repository target file is up-to-date with respect to a repository source file; and if the repository target file is not up-to-date, identifying as a build source a source file that matches the repository source file and building an updated build target file at the host based on the build source file. Build requests can be received and build reports can be displayed over the Web. In addition, the method, system, and product support versioning.

FIG. 1 is a block diagram of a typical programming environment 10. Generally, electronic files 12 are deposited into a repository 16, i.e., a host computer for storing electronic files. The electronic files 12 may be created by one or more content developers 14, e.g., software programmers.
The electronic files 12 stored in the repository 16 are typically "source files" and "target files." One or more source files (e.g., files written in source code) may be converted to a target file (e.g., an executable file) that is based on the source files using known software programs such as a compiler. The process of converting the source files to the target file is referred to as "building." The target file is then tested, and if problems are found, then the source files are changed to correct the problems, and then a new target file is built based on the modified source files. Once the target file functions as desired, it can be distributed to end users.
Presently, in order to build the target file from the source files, a build utility 20 such as a "make utility" is used. A make utility is a software tool for managing and maintaining computer programs. The make utility utilizes a makefile, which is created by the content developers 14 and stored in the repository 16, to identify source files on which the target file depends. When the make utility is run, the make utility rebuilds the target file only if one or more of the source files on which it depends has been changed since the last time the target file was built, thereby saving build time.
In determining when the source files and target file were last updated, the make utility relies on build indicators for the source files and the target file that identify the date and time they were last modified. A "source build indicator" represents the date and time a source file was created or last modified and a "target build indicator" represents the date and time the target file was built. If the target file has a target build indicator that indicates that it was built after the last modification of every source file on which it depends, a build will not be performed since the resulting target file will be based on the same source files as the existing target file and would, therefore, result in an identical target file. On the other hand, if a source file has been modified since the last build of the target file, the target file will be rebuilt.
To build a target file from source files in the typical programming environment 10, the electronic files 12 residing in the repository 16 (including the source files, the target file, and the makefile) are transferred to the host 18 in response to a build request received from a content developer 12, for example. If one or more of the source files have been updated since the last time the target file was built, a build utility 20 at the host 18 utilizes build tools (e.g., a compiler) residing on the host 18 to build a target file from the transferred source files on which the target file depends. This method of building a target file is inefficient.
Inefficiencies arise in the described build process because the target file, all the source files on which the target file depends, and the makefile are transferred from the repository 16 to the host 18 every time a build is requested, even if some or most of the source files have not changed or are already available at the host 18, and even if a build is not required. This is especially problematic when multiple content developers 12 are involved. For example, assume a system having three source files used to build a target file. In addition, assume a first programmer ("X") updates a first source file and a second programmer ("Y") updates a second source file, and, then, X requests a build followed by Y requesting a build. When X requests the build, all three source files (and the existing target file and the makefile) are transferred to the host 18, including the source files as updated by X and Y, and a new target file is built from these source files if one or more of them were updated since the last time the existing target file was built. When Y requests the build after X, the process of transferring the source files (and the target file and the makefile) to the host 18 occurs again. This transfer is redundant since the same files are already at the host 18.
Accordingly, there is a need for methods, systems, and products for remotely building electronic files that are more efficient. The present invention fulfills this needs among others.

International Business Machines Corporation


A dynamic memory circuit including memory cells arranged in an array of rows and columns, each row capable of being activated by a word line and each column being formed of cells connected to a first and to a second bit lines, which includes at least one, spare row formed of static memory cells, adapted to being activated to replace a memory cell row, each spare cell being connected to the first and second bit lines of a column of the circuit.

1. Field of the Invention
The present invention relates to DRAMs, and more specifically to DRAMs provided with spare structures for replacement of defective cells.
2. Discussion of the Related Art
FIG. 1A schematically shows a conventional DRAM architecture 2 arranged in rows and columns of memory cells 4 (MC). Each cell 4 (MC) is connected to a bit line 6 and to a word line 8 (WLi), with i ranging from 1 to n, n being the number of memory rows. Each memory cell column includes two bit lines 6 (BL1, BL2). The memory cells of each column are arranged alternately, the cells of the odd and even rows being respectively accessible by first and second bit lines BL1 and BL2. A cell, including a capacitor having a terminal connected to ground and a terminal connected to a bit line via a transistor that can be activated by a word line, is illustrated in FIG. 1B. A row address decoder (not shown) is provided for receiving an address and providing an activation signal on the corresponding word line WLi. A sense amplifier 10 (SA) has its two inputs respectively connected to the two bit lines BL1 and BL2. For clarity, only two bit lines and n rows of memory 2 have been shown in FIG. 1A.
A read/write operation in such a memory includes the following succession of steps. The information to be stored into cells MC is first written into each of these cells. This writing consists, by an addressing of the chosen cell and an appropriate connection of the corresponding bit line, of writing into each cell a high voltage or a low voltage. The low voltage substantially corresponds to the ground voltage and the high voltage is close to supply voltage VDD. However, in practice, the high voltage will inevitably be smaller than voltage VDD and moreover tends to decrease along time. This is why a periodic refreshment of the memory cells is further provided. Before each read operation, a bit line precharge operation is performed, that is, a given voltage, currently VDD/2, is applied to each bit line and is stored on the capacitor of this line. During an actual read operation, such as illustrated in FIG. 2, at a time t0, a memory cell is addressed and voltage VDD/2 initially existing on the bit line rises if the involved memory cell has stored a xe2x80x9c1xe2x80x9d (high voltage) and falls if the involved memory cell has stored a xe2x80x9c0xe2x80x9d (low voltage), and differential amplifier 10 measures the difference between this raised voltage or this lowered voltage and voltage VDD/2. However, due to the dissymetry of the operations of charge of a xe2x80x9c1xe2x80x9d and of a xe2x80x9c0xe2x80x9d, the difference between the two inputs of the operational amplifier will be smaller in the case where a xe2x80x9c1xe2x80x9d has been stored than in the case where a xe2x80x9c0xe2x80x9d has been stored. This difference will for example be, as indicated in FIG. 2, on the order of 100 millivolts for the storage of a xe2x80x9c1xe2x80x9d and on the order of 150 millivolts for the storage of a xe2x80x9c0xe2x80x9d. To solve this problem, the voltage received by the input of amplifier 10, which is not connected to the read memory cell, is generally modified to be made to fall to a value VREF smaller than VDD/2, so that, as illustrated in FIG. 2, the difference between voltage VREF and a high read voltage is substantially the same as the difference between voltage VREF and a low read voltage.
FIG. 3 schematically shows a conventional DRAM 12, similar to memory 2 of FIG. 1, each bit line of which is further connected to a voltage adjustment cell 14 (REF). Each of cells 14 is activated to bring the line to which it is connected to previously-defined value VREF at the beginning of a read phase of an adjacent line. Cells 14 are connected by activation lines 16 (RL1, RL2) to the row address decoder (not shown). The structure of voltage adjustment cells 14, which is known, will not be detailed herein.
Further, conventional DRAMs such as those described in FIGS. 1 and 3 come up against other problems. Indeed, the bit lines are generally relatively long and very close to one another. Thus, when two bit lines are simultaneously read, the voltage present on the first bit line can have an influence upon the voltage of the second bit line and disturb its reading. A solution to this problem consists of having each pair of bit lines cross once or several times, as schematically shown in FIG. 4A.
FIG. 4A shows two bit line pairs (BL1, BL2 and BL3, BL4) of a DRAM 18 with 256 rows. Each bit line is connected to 128 alternately arranged memory cells 4 (MC). Further, due to the bit line crossings, the rows of memory 18 are arranged in four sectors of 64 rows each, respectively corresponding to rows 1 to 64, 65 to 128, 129 to 192, and 193 to 256.
In the first sector, each odd row includes two adjacent memory cells respectively connected to bit lines BL1 and BL3 and each even row includes two adjacent memory cells respectively connected to bit lines BL2 and BL4. Bit lines BL1 and BL2 cross between rows 64 and 65 so that, in the second sector, the memory cells of the odd rows are respectively connected to bit lines BL2, BL3, and the memory cells of the even rows are respectively connected to bit lines BL1, BL4. Similarly, lines BL3 and BL4 cross between rows 128 and 129. Finally, lines BL1 and BL2 cross between rows 192 and 193. Each row can be activated by a word line WL1 to WL256.
Some memory cells 4 may be defective. To replace the defective cells, spare cells arranged in rows and columns are generally provided. When a defective cells is found, the row or column where this cell is present is xe2x80x9creplacedxe2x80x9d with a spare row or column. This is done by modifying the address decoder so that it addresses, instead of the defective row or column, a spare row or column. When several cells in a same row are defective, the row of these cells is xe2x80x9creplacedxe2x80x9d, which eliminates several defects at once.
FIG. 4B schematically shows rows of spare cells SC intended for replacing a defective row of memory 18. Bit lines BL1 to BL4 correspond to the end of the bit lines of FIG. 4A. Since there are four types of memory cell rows in memory 18, it is necessary to provide four spare rows to replace any row in the memory. When a row of memory 18 is deflective, the type of row involved is first determined. Then, a predetermined spare row corresponding to the type of the row to be replaced is associated therewith. Thus, for example, the odd rows of sector 1 and the even rows of sector 3 have the same configuration as the first spare row illustrated in FIG. 4B and will be replaced by it. Then, the address decoder will definitively associate the address of the defective row with that of the spare row. Each spare row is activated by an activation line, SELi, which will be activated upon addressing of the row.
When the number of errors desired to be corrected increases, the number of spare rows becomes high (all the more as four types of spare rows must be provided) and this creates many problems. Thus, the presence of many spare rows, connected to the bit lines, imposes a significant lengthening thereof, which reduces the voltage variation associated with the reading from a cell of a bit line. Also, when the number of spare rows is increased, the risks for a cell in a spare row to be itself defective is increased for statistical reasons, and the provision of spare cells replacing possible defective spare cells risks making the system complicated and difficult to manage. The spare rows further increase the total surface area occupied by the memory and the cost thereof. Further, the step of replacing a row containing a defective cell with a spare row is complex, since it requires precisely identifying the type of the row to replace it with an appropriate spare row taken from among all the available spare rows.
An object of the present invention is to provide, in a memory circuit, a spare memory cell row structure having a simpler and more efficient implementation.
Another object of the present invention is to provide such a circuit that occupies a reduced surface area as compared to conventional circuits with spare cells.
To achieve these objects, as well as others, the present invention provides a dynamic memory circuit including memory cells arranged in an array of rows and columns, each row being capable of being activated by a word line and each column being formed of cells connected to a first and to a second bit line, which includes at least one spare row formed of static memory cells, adapted to being activated to replace a memory cell row, each spare cell being connected to the first and second bit lines of a column of the circuit.
According to an embodiment of the present invention, the memory cell row replaced by the spare row is not addressed upon addressing of the spare row.
According to an embodiment of the present invention, the memory cell row replaced by the spare row is addressed upon addressing of the spare row.
According to an embodiment of the present invention, the bit lines cross at least once.
According to an embodiment of the present invention, the memory circuit further includes a sense amplifier on each memory column, the inputs of the amplifier being respectively connected to the first and second bit lines.
According to an embodiment of the present invention, the memory circuit further includes rows of voltage adjustment cells arranged either between the memory, cells of the memory and the spare cells or between the spare cells and the sense amplifiers.
The foregoing objects, features and advantages of the present invention, will be discussed in detail in the following non-limiting description of specific embodiments in connection with the accompanying drawings.

Dynamic memory circuit including spare cells


A multiple-mode hydraulic tracer valve which is convertible from mode to mode by the use of a shiftable stylus and a transmission whose locus can be shifted relative to the spool valves of the tracer valve without changing the relative settings between the spools and the sleeves of the spool valves.

Tracer valves are well known in the machine tool field. Basically they comprise spool valves whose control position is responsive to the reaction between a stylus of the valve and a pattern or template. The pattern or template is related to a workpiece in which the profile of the pattern or template is to be duplicated by a cutting tool. The tracer valves control the operation of motors which cause appropriate machine movements to occur.
Tracer valves and their various modes of operation are fully described in Paul J. Weaver U.S. Pat. No. 3,186,425 issued June 1, 1965. This Weaver patent is incorporated herein in its entirety for its showing of tracer valve construction and operation, and for its showing of certain problems in the prior art.
Conventional tracer valves provide for control over one or more axes of motion of the machine tool. In one common variety, three dimensional tracing is enabled wherein three orthogonally related single axis spool valves are adjusted by the stylus so as to control operation of three motors which drive machine tool components along respective axes. The mode involved is called "3D" tracing. A sub-species of this type is two-axis control, and this mode is frequently called "360.degree." tracing. 360.degree. tracing can be accomplished with a 3D tracer valve by disabling one of its three valves.
Still another mode of tracing operation is called "coordinated" tracing, wherein one sector of a single spool valve controls bi-directional movement along one axis, and another sector of the valve controls the rate of motion along an axis perpendicular to the first axis. In this mode of tracing, when velocity increases along one axis it slows along the other.
These foregoing modes are fully described and discussed in the said Weaver patent, and also in Rosebrook U.S. Pat. Nos. 2,753,145 and 2,835,466 issued July 3, 1956 and May 20, 1958, respectively, which are also incorporated herein by reference for their showing of structural and functional parts of such valves.
It has long been an objective to be able to utilize a single valve construction for as many modes of tracing as possible. The said Weaver patent does provide optimim versatility in a hydraulic tracer valve. It enables 360.degree., 3D, and coordinated tracing to be accomplished with only one valve. However, this valve has not become popular, because when converting from 3D or 360.degree. tracing to coordinated tracing, or vice versa, it is necessary to make too many adjustments to parts of the valve. It is an object of this invention to improve upon the valve shown in the said Weaver patent, and to simplify the conversion procedure in such a way that the spool valves themselves do not have to be repositioned or adjusted. There results an optimum valve with simple multiple mode convertibility.
A valve according to this invention includes a first spool valve intended to be aligned along a vertical axis. The valve includes a body which supports a stylus. The stylus has a first ball-like member which mounts it for universal pivotal motion, that is to say, the stylus tip may swing in all directions from the axis of the stylus. This first ball-like member is mounted in a first ball seat so the entire stylus is vertically moveable along said axis. The stylus includes a second ball-like member to which is mounted a scotch yoke that transmits lateral movement to a pair of orthogonally oriented, horizontal spool valves which exert control along their respective axes. A transmission is carried at the top of the stylus. The transmission includes a ball which is seated in a conical recess in the top of the stylus. This ball is confronted by and supports the bottom of a spool of the vertically mounted first valve. This support is by way of a conical recess, or a flat conversion surface. The spool includes conventional external grooves and lands which cooperate with respective grooves and lands in an encircling sleeve to provide control for flow of hydraulic fluid to cause appropriate machine tool movements. The conical recess carried by the spool is mounted to a plunger, which enables it to be shifted axially relative to the conversion surface.
According to a preferred but optional feature of this invention, the spool and sleeve of said first spool valve includes grooves and lands respective to a first and a second control mode, as well as to a coordinating sector used with one of said modes.